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  • 1970-1974  (755)
  • 1965-1969
  • 1950-1954
  • 1915-1919
  • 1870-1879
  • 1973  (755)
  • Organic Chemistry  (720)
  • Electron Microscopy
Material
Years
  • 1970-1974  (755)
  • 1965-1969
  • 1950-1954
  • 1915-1919
  • 1870-1879
Year
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 23 (1973), S. 133-140 
    ISSN: 1432-0533
    Keywords: Metachromatic Leukodystrophy ; Neuronal Inclusions ; Laminated Bodies ; Mucopolysaecharides ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructural findings of the metachromatic granules in the anterior horn cells of the spinal cord in a case of metachromatic leukodystrophy are presented. The typical neuronal inclusions are concentrically laminated bodies of approximately 1 μ. In addition various morphological variations of the abnormal inclusions are seen side by side in the same neuron and give the impression that the highly organized laminated bodies are formed as a result of progressive deposition of membranous material upon a nidas which is initially amorphous, which then becomes granular, fibrillar or horizontally striped and finally multilaminated. Material capable of binding colloidal iron particles is demonstrated in these inclusions, and suggests the presence of mucopolysaccharides.
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  • 2
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Encephalomyocarditis (EMC) Virus ; Neurotrophic Viruses ; Viremia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One hundred and eighty 12 week old Swiss mice were injected subcutaneously with 0.1 ml suspensions of the E and M variants of encephalomyocarditis (EMC) virus. Ninety-seven surviving mice were sacrificed at intervals from 24 h to 21 days following injection. The M variant group showed only mild microglial proliferation in the brain, while the E variant group displayed various alterations in the astrocytes and neurons exhibiting loss of nuclear membranes and marked changes in the mitochondria and other organelles. In addition, the neuronal cytoplasm displayed aggregates of fine electron-dense granules on the third day which increased in size during the fifth to seventh day. After 7 days, the neurons contained occasional rhomboid structures composed of rows of parallel arranged granules which were similar to those observed in the viscera after EMC virus infection.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 62-67 
    ISSN: 1432-0533
    Keywords: Dystrophia Myotonica ; Electron Microscopy ; „Fingerprint Inclusions” in Muscle Fibres
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary „Fingerprint inclusions” were observed in numerous muscle fibres of 3 cases of dystrophia myotonica studied by electron microscopy in two different laboratories. They consist of parallel or concentric palisades of short electron dense linear elements. Identical „fingerprint inclusions” were reported in two other clinical conditions and cannot therefore be regarded as specific for a particular muscle disease. Their origin and significance remain obscure.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 26 (1973), S. 45-57 
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Extracellular Fibrils ; Neurologia ; Retina ; New Formation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Extracellular formation of microfibrils was observed in the cavities of peripheral cystoid degeneration in senile human eyes. The ultrastructure of the fibrils is described and the source of production of the fibrillar material is discussed. It originates most probably from neurological cells, within or surrounding the cysts.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 25 (1973), S. 1-13 
    ISSN: 1432-0533
    Keywords: Electron Microscopy ; Myxopapillary Ependymoma ; Basement Membrane ; Filum Terminale ; Collagen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A fine structural study of a myxopapillary ependymoma of the filum terminale confirms and emphasizes the distinctive morphological features of this tumor. Electron basement membrane production were identified. It is suggested that they are related to the growth of ependymal tumor cells in juxtaposition to the collagen normally present in the conus medullaris and filum terminale.
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 25 (1973), S. 207-219 
    ISSN: 1432-0533
    Keywords: Aujeszky's Disease ; Inoculation ; Virus Particles ; Electron Microscopy ; Neuronal Degeneration ; Demyelination ; Axoplasmic Transport
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixteen calves were killed at intervals during the course of the disease from 48 h onwards after subcutaneous infection with Aujeszky's disease virus. Ultrastructural changes were evident in the spinal ganglia from 84 h post-inoculation and the intercostal nerves from 96 h post-inoculation. The cytopathic changes in the spinal ganglia consisted of neuronal degeneration, neuronophagia, Schwann cell degeneration and cellular infiltration. The neuronophagic nodule was invariably contained within an intact sheath of satellite cells. Changes in the intercostal nerves were less dramatic but cellular infiltration was frequently seen and occasional Schwann cells were degenerate. In the terminal stages of the disease demyelination was rarely observed. In the ganglion virus was invariably seen in degenerating neurons and occasionally in Schwann cells and monocytes. Satellite cells were rarely infected even when ensheathing an infected neuron. Extra-cellular virus was not observed in ganglia or nerves. Schwann cells and monocytes in the nerves were occasionally infected. Virus particles were seen in the axoplasm both in the ganglion and in the entire length of the nerve. The particles in the axoplasm varied in morphology; thus unenveloped and enveloped particles, and particles in the process of acquiring an envelope were recognised. It was concluded that the neural pathway of Aujeszky's disease virus is probablyvia the axoplasm.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-0533
    Keywords: Tissue Culture ; Electron Microscopy ; Enzyme Histochemistry ; Sympathetic Ganglioneuroblastoma ; Medulloblastoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The results of combined tissue culture, ultrastructural and enzyme histochemical investigations carried out on a sympathetic ganglioneuroblastoma are reported.In vitro a vigorous sprouting of newly formed neuritic processes was observed a few days after explantation. The enzymatic reactions for acethylcholinesterase were positivein situ as well asin vitro. The tumor elements showed the ultrastructural characteristics of nerve cells with many microtubuli and filaments, plenty of ribosomes, well developed endoplasmic reticulum. Dense bodies, corresponding to neurosecretion granula (catecholamines) were also observed. Synaptic structures were missing. The results of these investigations confirm that this kind of tumor is different from so-called medulloblastoma.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 23 (1973), S. 23-31 
    ISSN: 1432-0533
    Keywords: Chronic Polymyositis ; Virus-Like Particles ; Electron Microscopy ; Paramyxovirus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic examination of a biopsy of skeletal muscle from a young girl with chronic polymyositis revealed the presence of sarcoplasmic and perinuclear inclusions. A large number of virus-like particles was demonstrated at the surface of muscle cells and in extracellular space. On the basis of the microscopic appearance it is suggested that the virus particles belong to one of the members of the paramyxovirus group.
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 273-286 
    ISSN: 1432-0533
    Keywords: Muscle ; Acromegaly ; Histochemistry ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Muscle biopsies from 9 acromegalics were examined by conventional histological and histochemical techniques. Six biopsies were also examined with the electron microscope. Isolated fibre necrosis or vacuolar degeneration was found in 3 biopsies and increased numbers of internal nuclei in 5 biopsies. A high glycogen content was demonstrated in many fibres in each biopsy by the PAS method and by electron microscopy. Routine enzyme histochemical techniques showed hypertrophy of type I and type II fibres in 2 subjects, hypertrophy of type I fibres only in 2 subjects, atrophy of both fibre types in 2 subjects and atrophy of type II fibres only in 4 subjects. Electron microscopy showed large amounts of lipfuscin pigment in many fibres while some fibres had large sarcolemmal nuclei with prominent nucleoli, and a prominent Golgi apparatus. Satellite cells were found in 3 biopsies. In one biopsy coiled membranous configurations thought to consist of phospholipids, and tubular aggregates thought to be derived from degenerating mitochondria were present at the periphery of a number of type II fibres. It is postulated that some of the ultrastructural changes found in muscle fibres are the result of the growth hormone-induced hypertrophic process and the increased turnover of cytoplasmic components associated with it while others reflect the atrophic process in some muscle fibres.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 345-349 
    ISSN: 1432-0533
    Keywords: Cockayne's Syndrome ; Peripheral Nerve ; Electron Microscopy ; Demyelination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The ultrastructure of sural nerve biopsies was studied in two sisters with Cockayne's syndrome. Both had severe physical and mental retardation and evidence of peripheral neuropathy. Striking alterations in the myelin sheath with relative preservation of the axis cylinder were noted in both. There were also electron dense bodies in the Schwann cells. These findings support the suggestion that Cockayne's syndrome may be a form of leukodystrophy.
    Type of Medium: Electronic Resource
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  • 11
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 26 (1973), S. 259-264 
    ISSN: 1432-0533
    Keywords: 6-Aminonicotinamide ; Tissue Culture of Chick Spinal Cord ; Electron Microscopy ; Neurotoxic Effects ; Glucose-6-Phosphate Dehydrogenase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Well myelinated cultures of chick embryo spinal cord were exposed to medium containing 6-aminonicotinamide in a concentration of 0.5 mmol for up to 48 h. By 24–48 h of exposure to the antivitamin, neurons showed a granulovacuolar degeneration which later led to the formation of large vacuoles in the neuronal perikarya. Myelin degeneration was also observed in this period in the form of swelling, beading and ballooning. Electron microscopy revealed moderately swollen mitochondria and dilated endoplasmic reticulum as the earliest neuronal change. Later, neurons became pyknotic and the cytoplasmic organelles disintegrated. Presynaptic endings and glial cells, however, was spared any degenerative change. Intermittent and irregular splitting of myelin lamellae were also observed along the intraperiod lines. Biochemical assay of the glucose-6-phosphate dehydrogenase activity in the experimental cultures showed that 45% of the enzyme activity was lost during the 30-h period. It is concluded that the formation of 6-aminonicotinamide analogues of NAD and NADP coenzymes leads to the impairment of the pentose phosphate pathway and the glucose turnover, and thus produces neurotoxic effects in the central nervous system.
    Type of Medium: Electronic Resource
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  • 12
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 26 (1973), S. 275-284 
    ISSN: 1432-0533
    Keywords: Minimata Disease ; CNS Degenerative Disorder ; Mercury Poisoning ; Focal Demyelination ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A case of suspected mercury poisoning (Minamata disease) was studied. Microscopic and ultrastructural changes in the nervous system were compared with those of a confirmed case of mercury poisoning from Minamata Bay, Japan, and those from exprimental animals intoxicated with methyl mercury. Disintegration of the granular layer, disappearance of the Purkinje cells with Bergmann's fiber proliferation and demyelination of the fiber tracts were observed in the cerebellum. Ultrastructural examination also revelad extensive proliferation of astrocytic fibers and characteristic focal demyelination and loosening of the myelin sheaths in many nerve fibers. Such pathological changes were consistent with those observed in both human cases and experimental animals poisoned by methyl mercury.
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  • 13
    ISSN: 1432-0533
    Keywords: Cerebral Ischaemia ; Recirculation ; Enzyme Histochemistry ; Electron Microscopy ; Dendrite Swelling ; Pinocytosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Complete cerebral ischaemia of 30 and 90 min was produced in normothermic barbiturized cats by clamping the innominate and subclavian arteries and lowering the systemic blood pressure. When the brains were adequatly recirculated after 30 min of ischaemia, electron microscopical and histochemical changes observed at the end of the circulatory arrest, were almost fully reversible. Endothelial cells of capillaries showed increased number and size of pinocytotic vesicles and numerous intraluminal flaps. ATPase activity was increased in the capillary walls and glial cells. Opposite to this, severe and irreversible ultrastructural changes were observed after 90 min of ischaemia, and all the enzyme activities studied were sharply decreased.
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  • 14
    ISSN: 1432-0533
    Keywords: Experimental Neurinoma ; Schwannoma ; Nitrosourea ; Tumor Trausplantation ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nervous system tumors were induced in the offspring of BD-IX (inbred) and CFE (non-inbred) rats by transplacental administration of ethylnitrosourea. Tumors of the peripheral nervous system (PNS) were obtained in approximately 80% of all animals, and tumors of the central nervous system (CNS) in 16%. Although several peripheral nerves were sites of tumor formation, the trigeminal nerve was the most frequent nerve affected. In male CFE rats, 70% of all PNS tumors affected the trigeminal nerve. The incidence of trigeminal nerve tumors in female BD-IX rats was only 33% of PNS tumors. Light and electron microscopy showed that the PNS tumors are made-up of Schwann cells, and behave like malignant tumors. The tumors began as a proliferation of recognizable Schwann cells, later they lost their basement lamina, destroyed the nerve tissue and invaded neighboring structures, but did not metastasize. Like their human counterparts, they showed “dense” and “loose” areas. In both of these, Schwann cells were recognized as the tumor cells. Trigeminal nerve tumors were transplanted fromin vitro cultured cells or directly from transplanted fresh tumor fragments to isologous rats (BD-IX). Subcutaneous. intraperitoneal and intracerebral transplants were done. The morphology and behavior of the transplanted tumors were similar to the original malignant neurinomas.
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  • 15
    ISSN: 1432-0533
    Keywords: Chronic Progressive Ophthalmoplegia ; Cerebellar Ataxia ; Electron Microscopy ; Enzyme Histochemistry ; Mitochondria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Electron microscopic and enzyme histochemical studies were performed on the cerebellum and the ocular and deltoid muscles from a 38 year old woman who developed bilateral ptosis at the age of nine years. Histologically the cerebellum appeared normal. The biopsies of three ocular muscles showed varying sizes of muscle fibers which were rounded and contained increased numbers of subsarcolemmal nuclei. The deltoid muscle stained by hematoxylin and eosin appeared normal, but the trichrome stain showed increased numbers of red granules within the sarcolemma corresponding ultrastructurally to increased numbers of abnormal mitochondria. These abnormal mitochondria displayed increased reaction products with LDH, NADH and SDH preparations, while the muscle gave normal reaction in phosphorylase, PAS and myosin ATP preparations. Chemical studies on the cerebellum showed normal proteolipids, glycolipids and phospholipids. Ultrastructurally, the cerebellum, the myofibers of three ocular muscles and the deltoid muscle exhibited abnormal mitochondria which showed peculiarly arranged circular cristae. They frequently contained paracrystalline structures which consisted of individual tubules arranged in a helical pattern. Frequently, the abnormal mitochondria were replaced by dense rectangular inclusions and occasionally showed complete transition to crystalline structures.
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  • 16
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 23 (1973), S. 9-22 
    ISSN: 1432-0533
    Keywords: Earliest Ischaemic Neuronal Change ; Astrocytic Swelling ; Mitochondrial Swelling ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A combined light and electron microscope study was made of the alterations occurring in the neurones and astrocytes of the neocortex and hippocampus of rats killed immediately after intermittent exposures to nitrogen of 5 and 15 min. Blood flow in the right common carotid artery had previously been interrupted by application of an artery clasp which was removed after the exposure to nitrogen and the animals killed by perfusion-fixation with glutaraldehyde. Microvacuolation (MV), the earliest stage of anoxic-ischaemic neuronal damage, was observed in the ipsilateral neocortex and hippocampus of both groups and ischaemic cell change (ICC) bilaterally in the neocortex of animals exposed for 15 min. Ultrastructural examination showed the microvacuoles to be swollen mitochondria. Slightly dense, mildly distorted, non-vacuolated neurones were also seen in the neocortex and hippocampus. They did not exhibit the ultrastructural changes seen in MV and ICC. Swollen astrocytic processes were sometimes seen around the damaged neurones, more frequently after 15 min exposure. Slight swelling of perivascular astrocytic processes was occasionally observed while the extracullular spaces in the neuropil remained unaltered. This implies that the accumulation of fluid in oedematous grey matter is confined to the astrocytic compartment. The reversibility or otherwise of all the neuronal alterations is discussed.
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  • 17
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 25 (1973), S. 149-160 
    ISSN: 1432-0533
    Keywords: Nutritional Encephalopathy ; Brain Edema ; Vitamin E Deficiency ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Focal lesions were induced in the cerebellum by feeding chickens a diet high in unsaturated fats and deficient in vitamin E. Ultrastructurally, the lesions consisted of central and peripheral zones. The central zone was characterized in the cortex and white matter by enlargement of the intercellular space, swelling of astrocytes, vacuolization of oligodendrocytes, ballooning of nerve fibers, degenerative changes in small blood vessels, and extravasation of plasma and blood cells. The peripheral zone was characterized by enlargement of the intercellular space in the white matter, swelling of astrocytes in the cortex, and the accumulation of dark bodies in the endothelium of small blood vessels. The results suggest that this nutritional encephalopathy is caused by alterations in the permeability of the vascular bed due to the dietary stress of unsaturated fatty acids in the absence of vitamin E.
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  • 18
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 23 (1973), S. 326-333 
    ISSN: 1432-0533
    Keywords: Hexachlorophene Intoxication ; Cerebral Edema ; Status Spongiosus ; Electron Microscopy ; Myelinopathy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Hexachlorophene intoxication produced cerebral edema in rats and mice characterized by the accumulation of fluid within myelin sheaths. Vessels remained impermeable to Trypan Blue. The amount of water in the brains of affected mice gradually returned to normal when the animals were put back on a normal diet. Correspondingly the status spongiosus decreased in severity in recovering animals. Some axonal degeneration occurred but there was no evidence of any breakdown of myelin lipids. The similarity of this encephalopathy to that seen following intoxication with triethyltin, isonicotinic acid hydrazide and cuprizone is emphasized. The potential toxicity of hexachlorophene to human infants is discussed.
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  • 19
    ISSN: 1432-0533
    Keywords: Subarachnoid Hemorrhage ; Glycerol ; Phenoxybenzamine ; Cerebral Edema ; Prevention ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Twenty-four hours and one week, respectively, after subarachnoid hemorrhage (SAH) had been experimentally induced in baboons, therapeutic dosages of glycerol and/or phenoxybenzamine hydrochloride were injected intravenously. Groups of three animals were studied at various time intervals after SAH: one animal served as a control, one animal per group received phenoxybenzamine hydrochloride (PBZ), and thefinal animal received both PBZ and a 10% glycerol (in saline) injection. The animals were prepared for electron microscopy by whole body perfusion with a glutaraldehyde/phosphate fixative. Few ultrastructural abnormalities were noted in cerebral tissue in each of the animals receiving glycerol, whereas the brain tissue from the untreated animals and those which had been treated with PBZ alone showed morphological changes compatible with cerebral edema.
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  • 20
    ISSN: 1432-0533
    Keywords: Wilson's Hepato-lenticular Degeneration ; Primary Degeneration of Peripheral Nerve ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The sural nerve from a patient with'Wilson's hepato-lenticular degeneration was examined by electron microscopy. The myelin sheaths showed remarkable changes and the axons secondary changes, while the unmyelinated nerve fibres were intact. These findings demonstrate that pathological changes of peripheral nerves occur in Wilson's disease. The changes are considered to be primary degeneration of the myelin sheaths.
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  • 21
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 117-127 
    ISSN: 1432-0533
    Keywords: Pinealoma ; Two-Cell Type Pattern ; Electron Microscopy ; Germinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Four pinealomas of the two-cell type (atypical teratomas) were investigated by electron microscopy. They all showed the same unique histological ultrastructure. The lymphocyte-like cells did not differ ultrastructurally from lymphocytes. Many plasma cells with well-developed rough surfaced endoplasmic reticulum were also seen. The small cells and the plasma cells were considered to be derived from blood cells. A variety of the large cells in the process of differentiation were observed. They had a large and ovoid nucleus with uniform granular chromatin and contained one or more prominent nucleoli. The large cells had many dilated cytoplasmic cisternae, numerous glycogen granules of about 250–300 Å in diameter and annulate lamellae. Ultrastructurally, the pinealoma of the two-cell type resembled the seminoma of testis which is of germ cell origin. This suggests that the pinealoma may be of germ cell origin.
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  • 22
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 24 (1973), S. 128-152 
    ISSN: 1432-0533
    Keywords: Transneuronal Degeneration ; Olfactory Bulb ; Rabbit ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary After peripheral deafferentation of the olfactory bulb of the rabbit obtained either spontaneously by atrophic rhinitis (main bulb only) or surgically, a transneuronal degeneration is observed by light microscopy: narrowing of the outer plexiform layer (30 to 40%), decrease (40%) in mean area of the mitral cells, light texture of the periglomerular neuropil. The study by electron microscopy at survival-times of from 8 h to 6 months shows: 1. intraglomerular dendritic lesions; 2. rarefaction of thick dendrites in the outer plexiform layer; 3. reduction of Nissl bodies in mitral and tufted cells. 4. periglomerular lesions: their morphology and laminar aspect could evoke a vascular origin. The interpretation of these modifications and their relation to transneuronal atrophy are discussed. Dark mitral- or granule cells have been observed neither in the main nor in the accessory olfactory bulbs, even when complete denervation occured.
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  • 23
    Electronic Resource
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    Springer
    Acta neuropathologica 26 (1973), S. 247-251 
    ISSN: 1432-0533
    Keywords: Argyria ; Silver Deposition ; Choroid Plexus ; Silver Granules ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A 72-year-old woman developed generalized argyria after prolonged intranasal application of a colloidal silver solution. The brain parenchyma, including several infarcts, was free of silver, but the choroid plexus showed silver deposited in the basal lamina, the stroma including calcified bodies, and occasionally within a mesenchymal cell of the choroid plexus stroma. The basal lamina beneath the choroidal epithelium was most affected. The silver granules appeared solid and free of any limiting membrane.
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  • 24
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    Springer
    Acta neuropathologica 26 (1973), S. 317-327 
    ISSN: 1432-0533
    Keywords: Peripheral Neuropathy ; Tangier Disease ; Schwann Cells ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Nerve biopsy findings are recorded for two previously reported patients with Tangier disease (hereditary high density lipoprotein deficiency). Both cases showed unusual clinical manifestations in comparison with other reported cases. The neurological disorder, symptoms from which began in the third decade, gave rise to a lower motor neuron deficit of unique distribution, which was accompanied by progressive sensory impairment limited for many years to loss of pain and temperature sensibility, ultimately involving all sensory modalities. Both biopsy specimens displayed similar features, with a gross loss of unmyelinated and myelinated axons, an extensive accumulation of lipid within Schwann cells, and excessive endoneurial collagenization. The axonal loss appeared to represent a primary axonal degeneration, there being no evidence of a demyelinating process. It is suggested that the accumulation of cholesterol within Schwann cells may be the result of a failure of cholesterol removal mechanisms or of intracellular lipid transport.
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  • 25
    ISSN: 1432-0533
    Keywords: Neuronal Inclusions ; Cerebrum ; Cholesterol Inhibitor ; Rat ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Intraperitoneal injections of a hypocholesterolemic drug, AY9944 produced neuronal cytoplasmic inclusions in the brain of Wistar strain of rats. The inclusions were numerous and larger in size in the younger age groups but gradually decreased in number and size after 30 days of age. Only a few small inclusions were seen in rats of 35 days of age or older, in spite of continuous injection of the drug. Inclusions gradually decreased in number after discontinuation of the drug in a relatively younger age group. Injection of the drug in adult rats produced only a few small neuronal inclusions. Ultrastructurally, concentrical lamellar structures were the predominant ones in younger age groups but other types of inclusions were seen in older animals and those receiving lesser amounts of the drug or those which were examined after discontinuation of the drug. This observation suggests that morphologically different inclusions can be formed by basically the same treatment if there is any difference in the metabolic activity of the target cell or the amounts of the drug. Biochemical analysis of the sterols revealed a consistently high level of 7-dehydrocholesterol up to 69 days of age, when AY9944 was administered continuously, despite the fact that there was a decrease in the number and size of the abnormal neuronal inclusions.
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  • 26
    Electronic Resource
    Electronic Resource
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    Acta neuropathologica 25 (1973), S. 259-270 
    ISSN: 1432-0533
    Keywords: Tuberous Sclerosis ; Electron Microscopy ; Cerebral Biopsy ; Astrocytes ; Cerebral Tumor
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The electron microscopic study of a cortical biopsy from a child presenting a Tuberous Sclerosis shows the importance of the astrocytic gliosis, the existence of abnormal cells of which two types can be recognized, and the presence of giant cells. All these cells are remarkable by the abundance of the ergastoplasm, the development of the Golgi apparatus, and the presence of membrane bound dense bodies. These cells are undoubtedly of astrocytic origin and appear very similar to the cells observed in a tumour of the caudate nucleus of another child affected by the same disease. These morphological data lead to believe that the cerebral abnormalities of the Tuberous Sclerosis essentially concern the astrocytes. The main characteristic of this astrocytic lesion would be its blastomatous potentiality.
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  • 27
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    Calcified tissue international 12 (1973), S. 16-29 
    ISSN: 1432-0827
    Keywords: Bone ; Cartilage ; Culture ; Glycosaminoglycans ; Sephadex ; Collagen ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Des cultures de monocouches cellulaires d'épiphyses fémorales distales d'embryons de veaux sont étudiées immédiatement après la première sub-culture, réalisée après culture primaire. L'examen au microscope optique classique montre des dépôts disséminés de matériel métachromatique: en microscopie électronique, de fines fibrilles, considérées comme des fibres de collagène, en voie de développement, ont été observées. La nature des sécrétions cellulaires a été étudiée à l'aide de précurseurs radioactifs, fractionnés sur Sephadex G200, ainsi qu'à l'aide de chromatographie par échange d'ions. La digestion enzymatique par hyaluronidase et chondroitinase AC et ABC, bactérienne et testiculaire, démontre que les cellules synthétisent 70% de glycosaminoglycanes sulfatés et 30% de glycosaminoglycanes non sulfatés. Parmi les glycosaminoglycanes, 70% sont constitués par du chondroitine-4-sulfate, 20% par du chondroitine-6-sulfate et le reste probablement par du keratane-sulfate. Les études avec des acides aminés marqués indiquent que les cellules synthétisent une protéine de poids moléculaire élevé, contenant de l'hydroxyleproline, ainsi qu'une protéine non-collagénique, mise en évidence par incorporation de tryptophane.
    Abstract: Zusammenfassung Einschichtige Zellkulturen von der distalen Femurepiphyse von Kalbsembryonen wurden nach der ersten Subkultur untersucht, welche nach der Verschmelzung der primären Kulturen angesetzt wurde. Die lichtmikroskopische Untersuchung zeigte verstreute Ablagerungen von metachromatisch gefärbtem Material; bei der Elektronenmikroskopie wurden feine Fibrillen festgestellt, welche als Collagenvorstufe angesehen wurden. Nach einer Kultur von mehreren Tagen zeigte sich eine lacunäre Anordnung der Zellen. Die Beschaffenheit der Zellsekretionen wurde mittels radioaktiv markierten Verbindungen untersucht, welche auf Sephadex G200 und durch Ionenaustausch-Chromatographie fraktioniert wurden. Die enzymatische Verdauung mit bakterieller und testikulärer Hyaluronidase und Chondroitinase-AC und-ABC zeigte, daß die Zellen 70% sulfatierte und 30% nichtsulfatierte Glycosaminoglycane synthetisierten. Die sulfatierten Glycosaminoglycane enthielten 70% Chondroitin-4-Sulfat, 20% Chondroitin-6-Sulfat, und der Rest war wahrscheinlich Keratansulfat. Untersuchungen mit markierten Aminosäuren-Vorläufern deuteten darauf hin, daß die Zellen ein Hydroxyprolinhaltiges, hochmolekuläres Protein synthetisierten und dazu etwas Eiweiß, bei dem es sich auf Grund des Tryptophaneinbaues nicht um Collagen handeln kann.
    Notes: Abstract Monolayer cell cultures from the distal femoral epiphyses of embryo calves were studied following the first subculture, which was carried out after confluence in primary culture. Light microscopic examination revealed scattered deposits of metachromatic-staining material; on electron microscopy fine fibrils considered to be developmental collagen were seen. After several days in culture lacuna-like patterns of cells were seen. The nature of the cell secretions were studied by radioactive precursors, which were fractionated on Sephadex G200 and by ion exchange chromatography. Enzyme digestion with bacterial and testicular hyaluronidase and chondroitinase-AC and-ABC revealed that the cells synthesized 70% sulphated, and 30% non-sulphated glycosaminoglycans. Of the sulphated glycosaminoglycans 70% was chondroitin-4-sulphate, 20% chondroitin-6-sulphate, and the remainder probably keratansulphate. Studies were labelled amino acid precursors suggested that the cells synthesized a high-molecular weight protein containing hydroxyproline, as well as some non-collagenous protein, shown by tryptophan incorporation
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  • 28
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    Calcified tissue international 13 (1973), S. 83-92 
    ISSN: 1432-0827
    Keywords: Proteoglycan ; Collagen ; Cartilage ; Electron Microscopy ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé L'élimination de protéoglycans solubles de coupes de cartilage costal de boeuf, par extraction dans une solution de 4M d'hydrochlorure de guanidinium, permet de mettre en évidence des quantités abondantes de collagène dispersé et désagrégé dans la matrice. Les protéoglycanes, résistants à l'extraction, sont visibles sous forme de granules concentrés dans les régions périlacunaires. Les granulations plus importants des protéoglycanes semblent venir du chondrocyte. Dans la matrice, éloignée des chondrocytes, ces granules deviennent plus étroites. Un composant non granulaire “amorphe” masque les fibres de collagène, de telle sorte qu'elles sont difficilement visibles dans le cartilage intact.
    Abstract: Zusammenfassung Die löslichen Proteoglycane wurden mittels Extraktion in 4 M Guanidinhydrochlorid aus Rippenknorpelschnitten des Rindes entfernt. Dies erlaubte die Sichtbarmachung von großen Mengen von verstreuten und auseinandergerissenen Collagen in der Matrix. Die Protoglycane, welche sich nicht extrahieren lassen, erscheinen als kleine, in den perilacunären Regionen konzentrierte Körnchen. Die großen Proteoglycan-Körner scheinen in den Chondrocyten zu entstehen. Sobald sie sich in die Matrix, außerhalb der Chondrocyten, verlagern, werden die Körner kleiner. Ein nicht-granulärer, „amorpher” Bestandteil verhüllt die Collagenfasern, so daß diese im intakten Knorpel nicht deutlich gesehen werden können.
    Notes: Abstract Removal of the soluble proteoglycans from slices of bovine costal cartilage by extraction in 4 M guanidinium hydrochloride permitted the visualization of abundant amounts of dispersed and disaggregated collagen in the matrix. Proteoglycans which are resistant to extraction are seen as small granules which are concentrated in the perilacunar regions. Large proteoglycan granules appear to originate in the chondrocyte. As they come to occupy positions in the matrix distant from the chondrocyte, the granules become smaller. A non-granular, “amorphous” component masks the collagen fibers so that they cannot be readily seen in the intact cartilage.
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  • 29
    ISSN: 1432-0827
    Keywords: Amorphous ; Apatite ; Electron Microscopy ; Crystallization ; Precipitation ; Calcium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine , Physics
    Description / Table of Contents: Résumé Du phosphate de calcium amorphe (ACP) sèché peut se présenter sous forme discoide ou sphérique. Les particules discoides sont plus fréquents dans les specimens d'ACP sèché, isolés immédiatement après précipitation. Les formes sphériques dominent dans les specimens sèchés provenant de suspensions plus âgés. Les particules discoides résultent de la dessication de l'échantillon. Les sphères peuvent aussi se produire pendant la dessication, mais s'observent aussi dans la solution. Les disques et les sphères ont une origine commune sous la forme d'un agrégat d'ACP hautement hydraté de morphologie inconnue. La formation d'apatite cristallin en solution est intimement associée avec l'ACP. Les premiers cristaux apparaissent à la surface des sphères amorphes et en contact avec les disques amorphes. En cas de sphères, les cristaux initiaux augmentent de taille et forment de nouveaux cristaux par nucléation secondaire jusqu'à ce que les sphères soient enrobées par l'apatite. Cependant, lorsque la transformation est totale, l'apatite ne remplit pas l'espace occupé préalablement par les sphères amorphes dissoutes. Ces observations ne confirment pas le concept d'une conversion d'un état solidein situ dans ce cas mais suggèrent une transition hétérophasique d'un processus de translocation ionique par l'intermédiaire d'une solution. La production de cristaux dans les disques amorphes suggère que l'apatite peut aussi se former directement du précurseur dans la solution.
    Abstract: Zusammenfassung Getrocknetes amorphes Calciumphosphat (ACP) kann scheiben- und kugelförmig auftreten. Die scheibenförmigen Partikel herrschen in getrockneten ACP-Proben vor, welche direkt nach der Fällung isoliert wurden. Die kugeligen Formen herrschen in trockenen Proben aus älteren Suspensionen vor. Die Scheibenbildung ist ein Ergebnis des Trocknungsvorganges. Kugelige Formen können beim Trocknungsvorgang ebenfalls auftreten, sie sind aber in der nativen Suspension ebenfalls anwesend. Scheiben- und Kugelformen scheinen einen gemeinsamen Vorläufer in der Lösung zu haben, welcher ein hochhydratisiertes ACP-Aggregat unbekannter Morphologie zu sein scheint. Die Bildung von kristallinem Apatit in der Lösung steht in engem Zusammenhang mit ACP. Die ersten Kristalle erscheinen auf der Oberfläche der amorphen Kugeln und in Kontakt mit den amorphen Scheiben. Die ursprünglichen Kristalle auf den Kugeloberflächen nehmen an Größe zu und bilden durch sekundäre Nukleation weitere Kristalle, bis die Kugeln in Apatit eingehüllt werden. Wenn die Umwandlung abgeschlossen ist, füllt jedoch das Apatit den Platz nicht aus, der vorher von den aufgelösten amorphen Kugeln eingenommen wurde. Diese Beobachtungen bekräftigen die Auffassung einerin situ-Umwandlung in den festen Zustand bei dem beschriebenen Falle nicht, sondern deuten auf eine heterophasischen Übergang, welcher durch einen lösungsbedingten Ionenverschiebungs-Prozeß gefördert wird. Das Auftreten von Kristallen in den amorphen Scheiben deutet darauf hin, daß sich Apatit auch direkt aus dem Lösungsvorläufer bilden kann.
    Notes: Abstract Dried amorphous calcium phosphate (ACP) can exist in discoidal and spheroidal forms. The disk-shaped particles are most prominent in dried ACP specimens isolated immediately following precipitation. The spherical forms become dominant in dried specimens taken from older suspensions. The disk-like morphology is a result of sample drying. Spherules can also arise during the drying step but are present in the native suspension as well. Both the disks and spherules appear to have a common solution progenitor in the form of a highly hydrated ACP aggregate of unknown morphology. The formation of crystalline apatite in solution is intimately connected with ACP. The first crystals appear on the surface of the amorphous spherules and in contact with the amorphous disks. In the case of the spherules, the initial crystals increase in size and generate additional crystals by secondary nucleation until the spherules become enveloped by apatite. However, when conversion is completed, the apatite does not fill appreciably the space previously occupied by the dissolved amorphous spherules. These observations do not support the concept of anin situ solid state conversion in this case, but indicate a heterophase transition supported by a solution-mediated ion translocation process. The occurrence of crystals in the amorphous disks suggest that apatite can also form directly from the solution progenitor.
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  • 30
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    Lung 150 (1973), S. 49-59 
    ISSN: 1432-1750
    Keywords: Pigeon Breeder's Disease ; Electron Microscopy ; Pulmonary Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of the acute form of pigeon breeder's disease is presented. Electron-microscope studies show the histomorphological substrate of the foreign-body reaction and the immunological cell response caused by the inhaled pigeon material.
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  • 31
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    Lung 149 (1973), S. 181-192 
    ISSN: 1432-1750
    Keywords: Hyperoxia ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die elektronenmikroskopischen Ergebnisse bei Hyperoxie und hyperbarer Oxygenation bestätigen übereinstimmend in der Frühphase an der Lunge die exsudativen Veränderungen mit Endothelschwellung und latentem interstitiellen Ödem. Durch eine deutliche Verbreiterung des Blut-Luft-Weges besteht eine Reduktion in der Diffusionskapazität. Die Störungen in der Permeabilität der Zellmembranen betreffen zunächst mehr das Capillarendothel als das Alveolarepithel. Für das Auftreten der Zellschäden ist die Höhe des Saurerstoffpartialdruckes entscheidender als die hyperbare Oxygenation. Die Einatmung von reinem Sauerstoff im Überdruck führt zusätzlich über einen Anstieg des Kohlensäurepartialdruckes im Gewebe zu einer neurochemisch ausgelösten akuten Hypertension mit Lungenödem (Wood und Perkins, 1970). Das Lungenödem bei Hyperoxie und hyperbarer Oxygenation kommt sehr wahrscheinlich auf mehreren pathogenetischen Wegen zustande. Atelektasen bei Hyperoxie sind wahrscheinlich durch die Exsudation von fibrinmonomerhaltigem Blutplasma mit nachfolgender Inaktivierung vorhandener Surfactant-Aktivitäten sowie durch die Blockade der intracellulären Synthese des Surfactant ausgelöst. Zusätzlich sind direkte Enzymschäden der Zelle nach Sauerstoffvergiftung, besonders die Wirkungen der Peroxydationen auf die Mitochondrienmembranen zu berücksichtigen (Haugaard, 1968; Podlesch, 1972; Kleinschmidt, 1972). Der Schweregrad der Diffusionsstörung ist vom O2-Partial-druck und von der Expositionsdauer abhängig. Hibernation retardiert die Sauerstofftoxizität (Huizenga, Butcher und Simmonds, 1972). Die Lungen kleinerer Laboratoriumstiere reagieren schneller und empfindlicher auf O2-Schäden als die Lungen größerer Laboratoriumstiere und als die Lunge des Menschen. Kurzfristige Intervallbeatmung von 40%igem Sauerstoff im Inspirationsgemisch ist unschädlich und ruft keine Lungenveränderungen hervor. Trifft dagegen eine länger angewandte Hyperoxie auf eine vorgeschädigte Lunge, z. B. bei Schocksyndrom, Fettembolie oder Lungentrauma, müssen sich die Schäden aggravieren und können unter dem Bild eines progressiven Atemnotsyndroms zum Tode führen. Hyperoxische Lungenschäden benötigen aufgrund der elektronenmikroskopischen Befunde mehrere Monate bis zur anatomischen Ausheilung, wobei die Wiederherstellung der Lungenfunktion der anatomischen Ausheilung vorangeht.
    Notes: Abstract The results of electron microscope examinations during hyperoxia and hyperbaric oxygenation unanimously confirm the exudative changes in the lungs in the early stages, with endothelial swelling and latent interstitial oedema. Because of marked spreading of the blood-air paths, a reduction occurs in the diffusion capacity. Disturbances in the permeability of the cell membrane involve the capillary endothelium at first more than the alveolar epithelium. The level of the oxygen partial pressure is more decisive than hyperbaric oxygenation for the appearance of cell damage. Inspiration of pure oxygen at excess pressure also causes neurochemically induced acute hypertension with pulmonary oedema due to an increase in the partial pressure of carbon dioxide in tissues. Probably several pathogenic pathways are involved in the formation of pulmonary oedema in hyperoxia and hyperbaric oxygenation. In hyperoxia, atelectases are probably produced by the exudation of blood plasma containing fibrin monomer with subsequent inactivation of the surface activity present and by the blockade of the intracellular synthesis of surfactant. In addition, direct damage to cell enzymes after poisoning with oxygen, especially the effect of peroxidation on the mitochondrial membranes must be taken into account. The degree of severity of diffusion disturbance depends on the O2 partial pressure and on the duration of exposure. Hibernation delays the toxicity of oxygen. The lungs of smaller laboratory animals react more quickly and more sensitively to the harmful effects of O2 than the lungs of larger laboratory animals and man. Short periods of artificial respiration at intervals, with 40% oxygen in the inspiration mixture, are harmless and cause no changes in the lungs. However, if hyperoxia is used for a longer period, on a previously damaged lung, for example in shock, fat embolism or lung trauma, the damage becomes worse and may end in death resulting from progressive dyspnoea. The electron microscope findings show that in hyperoxic lung damage, several months are required for anatomical cure, the restoration of lung function preceding the anatomical cure.
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    European archives of psychiatry and clinical neuroscience 218 (1973), S. 79-91 
    ISSN: 1433-8491
    Keywords: Storage Disease ; Juvenile Amaurotic Idiocy ; Curvilinear Bodies ; Electron Microscopy ; Rectal Biopsy ; Speicherkrankheit ; Juvenile amaurotische Idiotie ; Curvilineäre Körper ; Elektronenmikroskopie ; Rectum Biopsie
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Bei einem Fall von juveniler amaurotischer Idiotie mit protrahiertem Verlauf (Beginn der Erkrankung mit 14 Jahren, Alter des Patienten 52 Jahre) wird über die Ultrastruktur des Speichermaterials in einer Rectumbiopsie berichtet. Das in Makrophagen der Mucosa gespeicherte Material entspricht den für die juvenile Form charakteristischen curvilineären Strukturen. Gegenüber der Kufsschen Form läßt sich der Fall ultrastrukturell durch das Fehlen der bei der Spätform beschriebenen Lipofuscin-Granula abgrenzen. Das klinische Bild spricht auch für die juvenile Form. Auffallend waren neben dem protrahierten Verlauf der verzögerte Beginn der Erkrankung sowie das späte Einsetzen der geistigen Retardierung.
    Notes: Summary The ultrastructure of storage material in a rectal biopsy taken from a patient with juvenile amaurotic idiocy with protracted course (onset of illness: 14 years; age of patient: 52 years) is described. The material stored in macrophages of the mucosa was like the curvilinear structures characteristic of the juvenile type. It was possible to exclude Kufs' type in this case by absence of the lipofuscin granula seen in the fine structures in the adult type. The clinical picture was also consistent with the juvenile form. Apart from the protracted course, other striking features were the delayed onset of the disease and the late beginning of mental retardation.
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    Pflügers Archiv 340 (1973), S. 361-366 
    ISSN: 1432-2013
    Keywords: M. rectus abdominis ; Slow Fibres ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Out of 253 muscle fibres taken from various parts of frog rectus abdominis muscles 52 were identified electron microscopically as slow. 48 slow fibres were localized at the ventral surface and at the linea alba. No evidence was found for the existence of a fibre type with structural features different from typical twitch or slow fibres.
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  • 34
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    Cell & tissue research 136 (1973), S. 19-30 
    ISSN: 1432-0878
    Keywords: Autonomic innervation ; Uterus ; Oviduct ; Adrenergic, Cholinergic ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary The fine structure of the preterminal nerve fibers of the rabbit myometrial smooth muscle was studied using potassium permanganate fixation or glutaraldehyde fixation with postosmification. The preterminal fibers were mostly formed by 2–10 axons enveloped by Schwann cells. Two kinds of axons and axon terminals were found. (1) Adrenergic axons, which contained many small, granular vesicles (diameter 300–600 Å) and large granular vesicles (diameter 700–1200 Å) which represented ca. 2% of the total count of the vesicles. (2) Nonadrenergic axons, which contained small agranular vesicles (diameter 300–600 Å) and large granular vesicles (diameter 700–1200 Å). Both types of axons formed preterminal varicosities along their course. The real terminal varicosities, representing the anatomical end of the axons, were usually larger than the preterminal ones and showed close contact to the plasma membranes of the smooth muscle cells. Both adrenergic and nonadrenergic terminals were found close to the smooth muscle cells, but a gap of at least 2000 Å was always present between the two cell membranes. The axons and preterminal varicosities of both types of nerves were in intimate contact with each other within the preterminal nerve fiber. Axo-axonal interactions between the two types of axons are possible in the rabbit myometrium. The relative proportion of the nonadrenergic axons from the total was about one fourth.
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  • 35
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    Cell & tissue research 136 (1973), S. 569-578 
    ISSN: 1432-0878
    Keywords: Myoepithelium ; Bryozoaire (Alcyonidium polyoum) ; Vacuole ; Striated muscle, muscular insertion ; Electron Microscopy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Description / Table of Contents: Résumé L'épithélium pharyngien d'Alcyonidium polyoum possède des cellules pourvues d'une très grande vacuole. L'incompressibilité du liquide vacuolaire permet un élargissement brusque de l'organe lors de la contraction du manchon musculaire strié qui enserre cette vacuole. Les fibres musculaires sont insérées sur le plasmalemme apical par des filaments unitifs. Le point d'attache est relié à la lame amorphe du cell-coat qui entoure les microvillosités par des fibrilles, réalisant probablement une liaison mécamique plus efficace. Le reticulum sarcoplasmique porte des ribosomes. Le cytoplasme apical renferme des vésicules de diverses catégories.
    Notes: Summary Pharyngeal cells of Alcyonidium polyoum (Bryozoa) are provided with very large vacuoles. Each vacuole is enveloped by a thin layer of striated muscle, whose contraction enlarges the organ. Filaments join the muscular elements to the apical plasmalemma. This point of muscular insertion is connected by fibrils with the amorphic lamina of cell-coat which surrounds the microvilli. Ribosomes are often found on dyads. Various vesicles are located in the apical cytoplasm.
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  • 36
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 202-210 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The U. V. and visible absorption spectra of α-nitroso-β-naphthol and nitroso-R-salt are recorded in solutions of varying pH. The U. V. bands are assigned to π → π* transition within the aromatic system while the visible bands are assigned to intramolecular charge transfer. The pK of both compounds are determined from spectrophotometric and pH measurements.
    Additional Material: 5 Ill.
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  • 37
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 235-243 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Treatment of the α, β-diketo-ester-α-arylhydrazones 1a-e and 2a-d with GRIGNARD reagents results in the formation of the ketocarbinols 3a-h and 4a-g, respectively. The arylhydrazones of ethyl mesoxalate 5a-e react with phenylmagnesium bromide to yield compounds 3a-e. A novel synthesis of α-arylazo-β-arylchalcones 6a-e and their reaction with hydrazines are reported.Whereas the arylhydrazones 10a, b, 2a, b, d, 13a-c and 14a-c react with piperidine and formaldehyde to yield the MANNICH bases 11a, b, 12a-c and 15a-c, compound 5a was recovered unchanged.
    Additional Material: 4 Tab.
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  • 38
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 258-264 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Tetracyclopentadienyl molybdenum(VI) oxide, (C5H5)4MoO 1 and tetraindenyl molybdenum(VI) oxide, (C9H7)4MoO 2 have been prepared by the interaction of (C5H5)2MoOCl2 3 or (C9H7)2MoOCl2 4 with sodium cyclopentadienide and sodium indenide, respectively. 1 and 2 have been alternatively prepared by the reaction of molybdenum oxide tetrachloride with sodium cyclopentadienide or sodium indenide respectively. Phenoxides of 3 and 4 have also been prepared. I. R. spectra and some other physical characteristics of all these compounds are reported.
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  • 39
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 265-273 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of 5-arylidene-4-arylimino-2-thiazolidinones 4 with GRIGNARD reagents effected 1,4-addition to the exocyclic —C=C— bond with the formation of 5. Alkylation of the arylidene derivatives 4 with diazomethane or methyl iodide results in the formation of the N-methyl derivatives 6. Treatment of 6 with phenylmagnesium bromide effects addition of the reagent to the double bond of the lateral chain to yield products, proved to have structure 8.The 5-arylazo derivatives 9 of 4-arylimino-2-thiazolidinones were obtained by coupling 4 with aromatic diazonium chlorides. Compounds 9 were N-methylated with diazomethane to yield 10.
    Additional Material: 4 Tab.
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  • 40
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 300-306 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The condensation of methyl-2-thienyl-, and phenyl-2-thienyl-ketones with dimethyl succinate in the presence of potassium t-butoxide or sodium hydride gave predominantly the (E)-half-estersi.e., CO2CH3 group and thiophene ring in trans-position. The nomenclature of cis/trans isomers used herein follows the IUPAC 1968 Tentative Rules, Section E, Fundamental Stereochemistry, J. org. Chemistry 35, 2849 (1970). See also: J. E. BLACKWOOD, C. L. GLADYS, K. L. LOENING, A. E. PETRARCA, and J. E. RUSH, J. Amer. chem. Soc. 90, 510 (1968); Introduction to Subject Index of Chem. Abstr. 66 (1963). 1a and 1d, which were cyclised to benzothiophene derivatives 2a and 2e, respectively. Methanolysis of the derived anhydrides 3a and 3 b led to the formation of the half-esters 1c and 1f. The (E)-dibasic acids 1b and 1e were converted by concentrated sulphuric acid to the lactones 4a and 4b. The methoxy-acid 2h gave upon such treatment the fluorenone derivative 5.
    Additional Material: 3 Tab.
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  • 41
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die kathodischen und anodischen Halbstufenpotentiale verschieden substituierter  -  sowohl an den Endatomen als auch in der Kette  -  Trimethine (Benzimido-, Benzthio-Benzoxo- und Benzselenotrimethincyanine) wurden in Acetonitril und Methanol bestimmt und in Abhängigkeit vom Lösungsmittel, von den Substituenten und verschiedenen Anionen diskutiert. Weiterhin wurden Zusammenhänge zwischen der Verschiebung von ΔE1/2 und der längstwelligen Absorptionsbande λ in Abhängigkeit vom Charakter der Substituenten verglichen und mit Hilfe der HMO-Theorie qualitativ gedeutet.
    Additional Material: 2 Ill.
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  • 42
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 347-349 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 43
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 295-299 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The condensation of pyrrolyl-2-aldehyde or 1-methyl-pyrrolyl-2-aldehyde with dimethyl succinate, using sodium hydride as condensing agent, gave predominantly the halfesters 1a and 1c respectively. Their structure and (E)-configurationi. e., pyrrol ring and COOCH3 group are in trans position. This nomenclature follows the IUPAC 1968 Tentative Rules, Section E, Fundamental Stereochemistry, J. org. Chemistry 35, 2849 (1970). were confirmed by their cyclisation to the corresponding indole derivatives 2a-h.
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  • 44
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wird über Ergebnisse der strahleninduzierten Copolymerisation von Bicyclo [2,2,1]-hepten-(2) (Norbornen) mit Vinylacetat und Vinylchlorid berichtet. Die Norbornenumsätze liegen bei der Copolymerisation mit den genannten Comonomeren bedeutend höher als bei der Homopolymerisation. Die Copolymerisation verläuft über einen Vinylpolymerisations-mechanismus, wobei echte Copolymere entstehen. Die gemessenen Reaktivitätsverhältnisse sind: \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm r}_{\rm N} = 0,13 \pm 0,08 $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm r}_{{\rm VAc}} = 2,4 \pm 0,7 $$\end{document} bzw. \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm r}_{\rm N} = 0,11 \pm 0,05 $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm r}_{{\rm VC}} = 2,1 \pm 0,2 $$\end{document}.
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  • 45
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 463-470 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Addition von NaP(C6H5)2 bzw. HP(C6H5)2 und H2PC6H5 an ω-Nitrostyrol führt nach Aufarbeitung zu (2-nitro-1-phenyl-äthyl)-substituierten Phosphinen. Der Einsatz von Phenylstyrylsulfon liefert lediglich mit NaP(C6H5)2 das (2-Phenyl-sulfono-1-phenyläthyl)-diphenylphosphin, während mit NaPHC6H5 Polystyrol, Natriumbenzolsulfinat und „Phenylphosphor“ entstehen. HP(C6H5)2 und H2PC6H5 verhalten sich gegenüber Phenylstyrylsulfon indifferent. Wird jedoch H2PC6H5 in Gegenwart katalytischer Mengen von NaPHC6H5 eingesetzt, dann läßt sich auch (2-Phenyl-sulfono-1-phenyläthyl)-phenylphosphin synthetisieren. Die Struktur der (2-Nitro-alkyl)-sowie (2-Sulfono-alkyl)-organophosphine wird IR-spektroskopisch und durch charakteristische Derivate gesichert.
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  • 46
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 471-482 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aus Natrium-phenylphosphid und γ-Chlorpropylmercaptan bzw. Cyclohexensulfid werden die ω-Mercaptoalkyl-phenyl-phosphine 1 bzw. 2 hergestellt. Diese sowie das β-Mercaptoäthyl-phenylphosphin 3 werden u.a. als Ammonium-dithiophosphinate charakterisiert und reagieren mit Sauerstoff unter Isomerisierung zu Alkyl-phenylphosphin-sulfiden. n-Butyllithium bzw. Natrium metallieren 1-3 primär an der SH- und sekundär an der PH-Gruppierung. 3 wird durch Chlorameisensäure-äthylester bzw. Acetylchlorid bei einem Molverhältnis von 1:1 an der SH-Gruppe acyliert; ein Überschuß von Acetylchlorid acyliert auch die PH-Gruppe. Äthylen- und Propylenoxid reagieren mit 1-3 unter Addition an die SH-Funktion. Phenylisocyanat dagegen setzt sich zunächst mit der PH-Funktion von 2 bzw. 3 unter Bildung der Carbamoyl-phosphine 17, 18 um. Mit überschüssigem Isocyanat reagiert dann auch die Mercaptogruppe. Phenylisothiocyanat reagiert nur im Molverhältnis 1:1, z.B. zu β-Mercaptoäthyl-phenyl-(N-phenyl-thiocarbamoyl)-phosphin 19, welches sich durch intramolekulare H2S-Abspaltung in 3-Phenyl-2-phenyl-imino-1,3-thiaphospholan 25 überführen läßt. Die Carbamoyl- bzw. Thiocarbamoylmercaptoalkylphosphine setzen sich mit Aminen zu den ω-Mercaptoalkyl-phenylphosphinen und disubstituierten Harnstoffen bzw. Thioharnstoffen um. Die IR-Spektren der dargestellten Verbindungen werden mitgeteilt.
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  • 47
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 526-538 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Durch radikalische Addition von Phenylphosphin an Allylamin bzw. dessen N-substituierte Derivate werden sekundäre (3-Aminopropyl)-phenylphosphine 1 synthetisiert. Die Acylierung der Aminopropylphosphine erfolgt ausschließlich am Stickstoff, während die Alkylierung tertiäre Phosphine liefert. Mit Carbonylverbindungen erfolgt intramolekulare Cyclokondensation im Sinne einer modifizierten MANNICH-Reaktion unter Bildung der 1,3-Azaphosphorinane 8. Diphenyldisulfid oder elementares Brom oxydieren Aminopropylphosphine zu 1,2-Azaphospholanen 10.
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  • 48
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 549-564 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die elektrochemische Lumineszenz von 1,3,5-Triphenyl-Δ2-pyrazolin 1 in Dimethyl-formamid besitzt im Unterschied zur blauen Fluoreszenz dieser Verbindung eine grüne Farbe. Spektroskopisch und elektrochemisch wurde nachgewiesen, daß diese Emission vom 4,4′-Bis-[3,5-diphenyl-Δ2-pyrazolinyl-(1)]-biphenyl 3 herrührt. 3 wird durch anodische Dimerisierung aus 1 bei der elektrochemischen Anregung der Lumineszenz gebildet. Die potentiostatische Oxydation in Acetonitril führt unter Aufnahme von 1,94 Faraday/Mol zu den zweifach positiv geladenen Kationen 8 des Dimerisierungsproduktes. Wie mit Hilfe der Absorptionsspektren bewiesen wurde, entstehen diese tiefblauen Dikationen in gleicher Weise durch chemische Oxydationsmittel in konzentrierter Schwefelsäure bei der Knorrschen Pyrazolinprobe. Die elektrochemische Reduktion von 8 in Acetonitril verläuft wie die Reduktion mit Zinkstaub über die Stufe der weinroten Radikalkationen 7 zu 3. Die präparative Darstellung von 3 durch elektrochemische Dimerisierung in einer ungeteilten Elektrolysezelle oder durch Oxydation mit Eisen(III)-chlorid in Acetonitril gelingt mit hoher Ausbeute.
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  • 49
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 587-599 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die NMR- und UV-Spektren einer Reihe Carbocyanine werden mitgeteilt und im Zusammenhang mit den Ergebnissen quantenchemischer Berechnungen in HMO-Näherung diskutiert. Unter dem Gesichtspunkt einer linearen Abhängigkeit der chemischen Verschiebungen von den π-Elektronendichten der den Protonen benachbarten C-Atome werden die Kernresonanzspektren diskutiert und die Veränderungen in der π-Elektronenalternierung der Polymethinkette bezüglich ihres Einflusses auf die Elektronenspektren betrachtet.
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  • 50
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 668-674 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bei der Photopolymerisation von Vinylchlorid in Tetrahydrofuran, 1,2-Dichloräthan und Diäthyloxalat bei -20°C werden einige kinetische Konstantenverhältnisse unter Berücksichtigung von Primärradikalabbruch und degradativer Kettenübertragung bestimmt.
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  • 51
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 690-700 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Elektronenstruktur von 1,2-Dithiolon-(4) 5, 1,3-Dithiolon-(4) 6 und Thiopyron-(3) 7 wurde nach halbempirischen MO-LCAO-Methoden mit und ohne S-3 d-Beteiligung berechnet. Die Ergebnisse zeigen, daß die Oktettaufweitung am Schwefel vernachlässigt werden kann. Während PPP-Berechnungen von 5 mit verschiedenen Elektronenwechsel-wirkungsintegralen zu einem Triplett-Grundzustand führten, lieferten uneingeschränkte HARTREE-FOCK-Berechnungen in CNDO/2-Allvalenzelektronennäherung einen Singulett-Grundzustand. Die mesoionischen Strukturen 5 bis 7 zeigen im energieärmsten Singulettzustand gegenüber den isomeren und iso-π-elektronischen KEKULÉ-Strukturen 8 bis 11 eine größere Polarität und tiefer liegende ππ*-Anregungszustände. Nach PPP-Berechnungen absorbieren die Verbindungen 5 bis 7 infolge eines intramolekularen CT-Übergangs im Sichtbaren. Die gefundenen spektralen Absorptionen von 3,4-Diphenyl-5, 2-Phenyl-6 und 2,5-Diphenyl-6 stehen mit den berechneten Werten in guter Übereinstimmung.
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 739-756 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wird die Synthese stereoisomerer 16-unsubstituierter und 16β-hydroxylierter 22,26-Epimino-5 α-cholestandiole-(3β, 20) beschrieben und deren Stereochemie im Piperidinring diskutiert. Photolyse der entsprechenden N-Nitroso- und N-Chloramine unter sauren Bedingungen führt ebenso wie die alkalisch katalysierte Heterolyse der N-Chloramine unter Spaltung zwischen C-20 und C-22 zu 20-Keto-pregnanen.
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  • 53
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 786-790 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
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  • 54
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 796-800 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 5 Tab.
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  • 55
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 829-842 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Wir untersuchten die Oligomerisierung von Acrylsäureester, Acrylnitril, Methylvinylketon, Acrolein und die Mischoligomerisierung von Acrylverbindungen, besonders von Acrylsäuremethylester und Acrylnitril, in Gegenwart von Alkylaminophosphinen. Die Selektivität der Katalysatoren drückt sich aus in der bevorzugten Codimerenbildung und dem gerichteten Einbau von Acrylnitril in die Cooligomeren.Die Mischoligomerisierung von Acrylsäuremethylester und Acrylnitril mit Diäthylamino-diäthylphosphin ergab die höchsten Ausbeuten am Codimeren.
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  • 56
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 865-872 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: X-ray analyses of chain-shaped and of coupled polymethines show an enlargement of the bond angles of the positively charged methine atoms and a contraction of the bond angles of the negatively charged methine atoms. The bond angle alteration can be explained by deviations from the trigonal hybridisation of the methine atoms. There exists a simple linear function between the square of the hybridisation parameter λ and the total charge densities calculated by means of the CNDO/2 method: λ2 ≅ 2 - Q.
    Additional Material: 3 Ill.
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  • 57
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 895-900 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3′-Desoxy-3′-fluor-5′-O-mesyl-thymidin 3 wird als Ausgangsprodukt für verbesserte Synthesen des potentiellen Cancerostatikums 3′-Desoxy-3′ -fluor-thymidin 4 sowie zur Gewinnung von 3′, 5′-Didesoxy-3′, 5′-difluor-thymidin 7 und 3′,5′ -Didesoxy-3′ -fluor-5′ -jodthymidin 8 verwendet. Die Darstellung der zu 4 analogen Fluornucleoside 2′, 3′ -Didesoxy - 3′ -fluor-uridin und -cytidin wird beschrieben.
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  • 58
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 915-928 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3,4-Thiadiazolidindithion-(2,5) 1 gibt bei der Umsetzung mit 2,3,4,6-Tetra-O-acetyl-α-D-glucopyranosylbromid (α-Acetobromglucose, ABG) nach dem SABALITSCHKA- und dem LATHAM-Verfahren Gemische von acetyliertem S, S′-Bisglucosid 2 und S,N-Bisglucosid 3. Bei Einsatz eines Aglykon-Überschusses kann das acetylierte S-Monoglucosid 4 erhalten werden. Umsetzung von 1 nach dem Quecksilberverfahren und HgBr2-katalysierte S → N-Umglykosidierung von 2 und 4 ergeben ausschließlich 3. Desgleichen führt die Umsetzung von 5-Methylmercapto-1,3,4-thiadiazolinthion-(2) 5 nach dem SABALITSCHKA- und dem LATHAM-Verfahren zu Gemischen des acetylierten S-Glucosids 6 und des acetylierten N-Glucosids 7. 7 entsteht als einziges Glucosid bei der Umsetzung von 5 nach dem Quecksilberverfahren und bei der S → N-Umglykosidierung von 6. Aus 4-Methyl- und 4-Phenyl-1,3,4-thiadiazolidinthion-(2,5) 11 und 9 entstehen bei der Umsetzung nach allen genannten Glykosidierungsverfahren praktisch ausschließlich die acetylierten S-Glucoside 12 bzw. 9.
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  • 59
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 935-939 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dichlorsulfan (Schwefeldichlorid) bis-acyliert Enamine. Die Reaktion ermöglicht die Herstellung von 3-Thia-1, 5-dicarbonylverbindungen 2. Analog erhält man aus Enaminen und Dichlordisulfan 3, 4-Dithia-1, 6-dialdehyde 5.
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  • 60
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 958-964 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wurde die Umsetzung von Cyclopentadien mit Äthylenoxid in Gegenwart basischer Katalysatorsysteme untersucht. Neben β-Hydroxyäthyl-cyclopentadien 1 entstehen vorwiegend DIELS-ALDER-Addukte mit Tricyclo[5,2,1,02.6]decan-Struktur. Das Isomerenverhältnis der gebildeten β-Hydroxyäthylcyclopentadiene 1 a:1 b (44:56) wurde NMR-spektroskopisch bestimmt. Die Geschwindigkeiten der Homodimerisierung von 1 und Cyclopentadien verhalten sich bei 70 °C etwa wie 1:2.
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 983-985 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
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  • 62
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 901-908 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Farbreaktion von 4-(4-Nitrobenzyl)-pyridin 1 (NBP) mit Phosphon-, Phosphor- und Thiophosphorsäurealkylestern 4 sowie mit entsprechenden Alkylesterhalogeniden beruht nicht  -  wie bisher verschiedentlich angenommen  -  auf einer Phosphorylierung, sondern auf einer Alkylierung des Pyridinstickstoffs. Die primär entstehenden N-Alkyl-pyridiniumsalze 5 lassen sich als Perchlorate 6 isolieren und zu definierten Farbbasen 7 deprotonieren. Letztere sind einer erneuten Alkylierung am Benzyliden-C-Atom zugänglich. Die spektroskopischen Eigenschaften der hierbei resultierenden Farbstoffe 8 werden diskutiert.
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  • 63
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 909-914 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Versuche zur Eliminierung der 19-Methylgruppe aus Derivaten der 3 α-Hydroxy-6-oxo-5α-cholansäure durch Hypojoditreaktion werden beschrieben.
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  • 64
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 940-948 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dichlorsulfan (Schwefeldichlorid) addiert sich an zwei Moleküle Vinyl- bzw. Enoläther. Die Addukte sind unterschiedlich beständig gegen Hydrolyse und bilden dabei 3-thia-1,5-dicarbonylverbindungen 4 bzw. 1,4-Oxthian-Derivate 5.  -  Äthoxycyclohexen reagiert andersartig zu Di-(2-oxo-cyclohexyl)-disulfid 13.
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  • 65
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 8-22 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ausgehend von 3β, 17 α-Diacetoxy-Δ5-pregnenon-(20) 1 werden neue Synthesen für 17 α-Acetoxy-6-chlor-6-dehydroprogesteron 19 (Chlormadinon) mitgeteilt. Dazu werden nach Substitution der 7 α-Stellung durch Addition an die Δ5-Doppelbindung 3,5,6,7-tetrasubstituierte Zwischenprodukte hergestellt, aus denen in der letzten Stufe die überzähligen Substituenten eliminiert werden. Die Strukturen werden vorwiegend durch spektroskopische Daten gesichert. Für die chemische Verschiebung der Protonen von -Gruppen in den untersuchten Chlorsteroiden werden τ-Werte von 5,4 bis 6,0 ppm gefunden.
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  • 66
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 44-46 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cyanamid reagiert mit Mandelsäurenitril und Benzaldehyd zum 2-Amino-5-cyan-4,5-diphenyl-Δ2-oxazolin 1, das in Gegenwart von Basen einer Eliminierung zu 2-Amino-4,5-diphenyl-oxazol 2 unterliegt und säurekatalysiert zum 2-Amino-5-cyan-4,5-diphenyl-oxazolidinon 4 hydrolysiert wird.
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  • 67
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 73-78 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Das Redoxverhalten von Monothio-β-diketonen wird polarographisch untersucht und ein Reaktionsmechanismus für die in 3 Stufen ablaufende polarographische Reduktion abgeleitet. Die elektrochemische Oxydation verläuft in nicht auswertbaren irreversiblen Mehrelektronenstufen.
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 58-64 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Für 38 Olefine wurden die Reaktionsgeschwindigkeiten mit Peressigsäure in Eisessig bei 25°C bestimmt. Unter Einbeziehung von Literaturwerten für weitere 8 Olefine wurden die Reaktionsgeschwindigkeiten von 37 offenkettigen Olefinen mit der Drei- und der Fünfparameter-TAFT-Gleichung korreliert. Die Reaktionskonstanten ∂* = -1,62 bzw. ∂*1 = -1,78 und ∂*2 = -1,35 sprechen für einen relativ symmetrischen Übergangszustand, der keinen Carbeniumionencharakter besitzt.
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  • 69
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 79-87 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Umsetzung von 1-Diphenoxyphosphoryl-4-alkyl- oder -aralkyl-thiosemicarbaziden 3a-d, die aus Phosphorsäurediphenylesterhydrazid und Senfölen gewonnen werden, mit Phenacylbromid 1a führt erwartungsgemäß zu 3-Alkyl-bzw. Aralkyl-4-phenylthiazolon-(2)-diphenoxyphosphoryl-hydrazonen 6. Analog reagieren 1-Diphenylphosphinyl-4-alkyl- bzw.-aralkylthiosemicarbazide 2c-e mit α-Halogenketonen 1 nur zu 4-substituierten 3-alkyl- bzw. Aralkylthiazolon-(2)-diphenylphosphinylhydrazonen 5. Dagegen entstehen aus 1-Diphenylphosphinyl-4-arylthiosemicarbaziden 2a,b mit 1 sowohl 4-substituierte 3-Arylthiazolon-(2)-diphenylphosphinylhydrazone 5a-d als auch 4-substituierte 2-Arylimino-3-diphenylphosphinylaminothiazoline 4a-d.
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  • 70
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 339-344 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 71
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973) 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 72
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (Z)- and (E)-3-methoxycarbonyl-2-methyl-4-(2′-naphthyl)-4-phenyl-but-3-enoic acids 1 a and 4 a have been converted into methyl-4-acetoxy-3-methyl-1-phenylphenanthrene-2-carboxylate 2 a and methyl 4-acetoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 a. The derived phenolic acids 2 b and 5 b are converted to methyl 4-methoxy-3-methyl-1-phenyl-phenanthrene-2-carboxylate 2 c and methyl 4-methoxy-3-methyl-1-(2′-naphthyl)-2-naphthoate 5 c; which are saponified to the corresponding methoxy acids 2 d and 5 d. Alcoholysis of the anhydrides 3 and 6 gives the corresponding half-esters 1 c and 4 c, respectively.
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  • 73
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 436-442 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis, some dyeing and fastness properties of several new monoazo dyes derived from 6-amino- and 6-hydroxy-quinolines when applied as dispersed dyes on nylon 6 are described. Preliminary correlations between light fastness and chemical structure are attempted.
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  • 74
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 483-491 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Kristallstruktur des 2-[1-Methylpiperidinio-(1)]-2′-chlor-acetanilid-jodids ist orthorhombisch, Raumgruppe Pna21, mit vier Formeleinheiten C14H20N2OClJ in der Elementarzelle. Die Gitterkonstanten sind a = 12,502, b = 17,124 und c = 7,418 Å. Es wurde der sterische Gesamtaufbau der Struktur bestimmt und die Existenz einer Wasserstoffbrücke zwischen dem Stickstoffatom der Carbonamidgruppe und dem Jodatom nachgewiesen.
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  • 75
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 565-571 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Tab.
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  • 76
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 577-586 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dialkylaminophosphine sind wirksame Katalysatoren für die Oligomerisierung von Acrylverbindungen. Durch elektronegative und -positive sowie raumfüllende Substituenten am Phosphor- und Stickstoffatom wurde die katalytische Aktivität variiert. Die katalytische Aktivität der Phosphinverbindungen wurde nach der bei der Oligomerisierung von Acrylsäuremethylester erhaltenen Menge an α-Methylenglutarsäuredimethylester sowie durch refraktometrische Verfolgung des Reaktionsverlaufs beurteilt.
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  • 77
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die elektrochemische Reduktion und Oxydation von Diphenylanthracen (DPA) und Dibiphenylylanthracen (DBPA) wurde untersucht und dabei gezeigt, daß es sich bei der Bildung der Kationen und Anionen um reversible Elektrodenprozesse handelt. Die UV-Spektren des DPA und DBPA sowie die Hyperfeinstruktur der Radikalionen des Anthracens, DPA und DBPA werden angegeben. Die experimentell bestimmten Kopplungskonstanten werden mit HMO-Daten verglichen. Die Ergebnisse zeigen ähnliche elektrochemische und spektroskopische Eigenschaften für DPA und DBPA.
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  • 78
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Experimentell ermittelte UV-, ESR- und elektrochemische Daten arylsubstituierter Anthracene werden an Hand von Modellrechnungen und Literaturdaten diskutiert. Dabei kann gezeigt werden, daß diese Eigenschaften im wesentlichen durch die Molekülgeometrie, hier repräsentiert durch Verdrillungswinkel, bestimmt werden. Ein spezifischer Einfluß der Arylsubstituenten auf die elektronischen Eigenschaften des Grundkörpers konnte nicht nachgewiesen werden.
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  • 79
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 657-667 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Ausgehend von dem Umsetzungsprodukt aus Cyclopentadien und Keten, dem Bicyclo [3,2,0]hepten-(2)-on-(6) 1, gelangt man auf verschiedenen Wegen zu Cycloheptadienen und Cycloheptatrienen.
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  • 80
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 701-710 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wird eine neue Synthese von Desaminothiamin beschrieben, die eine Ankondensation des Thiazolringes an das aus α-Formyl-β-benzoylamino-propionsäureäthylester und Acetamidin-hydrochlorid über mehrere Stufen erhältliche 5-Aminomethyl-2-methylpyrimidin vorsieht.Zur Darstellung von 2′-Desmethylthiamin wurde das aus s-Triazin und Malodinitril erhältliche 4-Amino-5-cyanpyrimidin mit Pd/Kohle hydriert und der Thiazolteil mit CS2 und 3-Chlor-pentanol-(1)-on-(4) ankondensiert.N-1-alkylsubstituierte Imidazolium-Analoge des Thiamins werden durch Entschwefeln ihrer aus Thiamindisulfid und Alkylamin bzw. aus dem Na-Salz des Thiamins, Alkylamin und Schwefel darstellbaren 2-Thioderivate mit H2O2 erhalten.Durch Erhitzen der in 4′-Stellung aminsubstituierten Verbindungen mit Salzsäure entstehen die entsprechenden 4′-Hydroxyderivate.
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  • 81
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973) 
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 82
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 817-828 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polarographic behaviour of thio-lactic acid (RSH) at d.m.e. has been investigated in the presence of KNO3 and in different water-ethanol (0 - 50% by volume) mixtures at 30.0 ± 0.2°C. A solution of 0.001% Triton X-100 was used as maximum suppressor. The effect of pH, concentration, temperature, drop time and solvent composition on the characteristics and mechanism of the electrode reaction have been studied in detail. The wave was diffusion controlled, reversible one electron and proportional to RSH concentration in different ethanolic media. The anodic wave of RSH at d.m.e. does not correspond to the formation of RSSR, but to a mercury compound RSHg. The diffusion current (id) decreases with increasing concentration of ethanol and is proportional to the square root of viscosity of the medium. The value of E1/2 shifts towards more negative potentials and the values of the dissociation constant decrease with increasing ethanol concentration. The linearity of id with RSH concentration provides a rapid and precise method for the determination of RSH down to 0.03 mM.
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  • 83
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 873-880 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: β-Thioketoaldehyde 1 werden durch Umsetzungen von β-Chlorvinylaldehyden mit Na2S · 9 H2O präparativ dargestellt. Von den möglichen tautomeren Formen dominiert im Gleichgewicht sowohl im festen Zustand als auch in Schwefelkohlenstofflösung der Enthiolaldehyd. Zur Charakterisierung eignen sich die leicht zugänglichen Nickelchelate. Folgereaktionen von 1 mit Phenylhydrazin, Anilin, Alkylhalogeniden und α-Halogencarbonylverbindungen führen zu Pyrazolen, S-haltigen SCHIFFschen Basen, Alkylmercaptovinylaldehyden und Thiophenen, die im einzelnen beschrieben werden.
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  • 84
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    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Nach der PPP-Methode werden einige Grundzustandseigenschaften und die Elektronenspektren der Titelverbindungen untersucht.Aus den Elektronendichten lassen sich nur bedingt Reaktivitätsvoraussagen treffen. Die aus den Bindungsordnungen berechneten Bindungslängen sind im Naphthalingerüst bei allen Verbindungen gleich denen im Fluoranthen. Im heterocyclischen Ring dagegen treten beträchtliche Unterschiede in Abhängigkeit von Art und Stellung des Heteroatoms auf.Die UV-Spektren können durch die Rechnungen gut interpretiert werden. Die gelbe Farbe der Heterocyclen mit C1h-Symmetrie, die durch eine Absorptionsbande um 400 nm verursacht wird, entspricht einem 2-1′-Übergang (Perimetermodell: 1A → 1Lb-Übergang). In den Verbindungen mit C2v-Symmetrie liegt dieser Übergang sehr dicht am 1-1′ (1A → 1La)-Übergang unterhalb 360 nm.
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  • 85
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1152-1160 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 86
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 993-1001 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Reaktion von 3-Hydroxy-2-phenyl-3-[thienyl-(2)]-propionsäuren 1a-d mit Acetanhydrid und katalytischen Mengen von Zinkchlorid führt in der Hauptsache zu 3-Phenyl-4-[thienyl-(2)]-buten-(3)-onen-(2) 3a-d. Daneben bilden sich 1-Phenyl-2-[thienyl-(2)]-alkene-(1) und in einem Falle (aus 1b) 2-Phenyl-3-[thienyl-(2)]-indenon-(1) 4. Als Zwischenprodukte der Reaktion werden gemischte Anhydride von 3-Acetoxy-3-[thienyl-(2)]-2-phenyl-propionsäuren bzw. von 3-[Thienyl-(2)]-2-phenyl-acrylsäure mit Essigsäure isoliert. Die Struktur von 3a-d sowie einer Reihe anderer Produkte wird durch die IR-, UV- und NMR-Spektren gestützt. Ein wahrscheinlicher Mechanismus der Reaktion wird vorgeschlagen.
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  • 87
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1037-1044 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es wird die Synthese von α-Amino-chlormethylketonen 1, 2 aus Aminosäuren mit freier und N-alkylierter Aminogruppe über die Diazoketone sowie die Darstellung der entsprechenden Aminosäurehydrazide 4 beschrieben. Durch Kupplung von N-Acylaminosäuren mit α-Amino-chlormethylketonen und Abspaltung der Schutzgruppe wurden α-Amino-chlormethylketone von Peptiden mit freier N-terminaler Aminofunktion (3) erhalten.Es wird auf die Eigenschaften der Verbindungen und speziell die Instabilität der α-Aminoketone eingegangen.
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  • 88
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1067-1076 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Bei der Umsetzung von Butadien in Gegenwart von homogen gelösten Katalysatorsystemen aus Palladium(II)-acetylacetonat und verschiedenen Verbindungen des dreiwertigen Phosphors bilden sich bei Anwesenheit von Alkoholen Gemische aus n-Octatrienen-(1,3,7), 1-Alkoxyoctadien-(2-t,7) und wenig 3-Alkoxyoctadien-(1,7). Es wird die Abhängigkeit der Zusammensetzung des Produktgemisches von den zugesetzten Komplexliganden, Alkoholen und weiteren Versuchsparametern, wie Molverhältnissen und Temperatur untersucht. Durch kinetische Verfolgung der Reaktion werden das Geschwindigkeitsgesetz und die Aktivierungsparameter erhalten.
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  • 89
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1113-1120 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Die Synthesen der isomeren 4′-substituierten 2,5-Diphenylpyrimidine mit n-Alkyloder n-Alkoxyresten als Flügelgruppen werden beschrieben und die kristallin-flüssigen Eigenschaften dieser Verbindungen diskutiert. Die Dipolmomente einiger Vertreter werden angegeben.
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  • 90
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1139-1151 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,3-Dithiol-thione-(2) und 1,3-Dithiolone-(2) fragmentieren massenspektroskopisch bevorzugt unter CS2-, C=S- bzw. (CO + S)- und C=O-Abspaltung. Weiterhin treten SH- und S2-Fragmentierungen auf. Der Fragmentierungsablauf des 1,3-Dithiolringes wird durch Substituenten in 4,5-Stellung beeinflußt.Die Spektrenauswertung erfolgte maschinell unter Anwendung des R-300.
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  • 91
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 1169-1174 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 92
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 31-38 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Im Rahmen komplexchemischer Untersuchungen werden eine Reihe unterschiedlich substituierter Pivaloylacylmethane dargestellt, ihre Enolgehalte ermittelt und die Säurekonstanten bestimmt. Die Interpretation der Meßergebnisse erfolgt auf der Basis sterischer Einflüsse und der HAMMETT-Gleichung.
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  • 93
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 65-72 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Während sekundäre 2-Aminoäthylarsine, RAs(H)CH2—CH2—NHR′ mit α-Ketocarbonsäuren und deren Ester in glatter Reaktion zu 1,3-Azarsolidin-2-carbonsäuren 1-6 bzw. deren Estern reagieren, werden im Falle der β-Ketocarbonsäureester je nach den Reaktionsbedingungen entweder die 1,3-Azarsolidin-2-essigsäureester 11 oder Enaminoester 10 erhalten. Die Umsetzung der γ- und δ-Ketocarbonsäuren und deren Ester mit 2-Aminoäthylphenylarsin liefert bicyclische 1,3-Azarsolidin-2,3-γ- bzw. -δ-lactame 12, und 13. Die Eigenschaften der einzelnen Substanzklassen werden beschrieben.
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 88-96 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: o-Methylstyrole cyclisieren in Gegenwart von Na/Al2O3- oder K/Al2O3 im Temperaturbereich von 60 bis 120° nicht. 5-Vinylbicyclo[2,2,2]octen-(2) isomerisiert unter diesen Bedingungen zu 5-Äthylidenbicyclo[2,2,2]octen-(2). Die Bildung von 1-Vinyltricyclo-[2,2,2,02,6]octan konnte nicht nachgewiesen werden.3,3-Dimethylhexadien-(1,4) isomerisiert unter den Bedingungen der Basenkatalyse zu 1,1-Dimethylcyclohexen-(2) und 1,1-Dimethylcyclohexen-(3).
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  • 95
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 125-136 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Es werden die im Elektronenanlagerungs-Massenspektrographen aufgenommenen Anionen- und Kationenspektren von Steroiden der 20-Chlorpregnan-Reihe vergleichend untersucht. In den Anionenspektren wird hierbei neben einem (M-1)-Mechanismus als typisches Verhalten dieser Substanzklasse eine zu (M + 35)- bzw. (M + 37)-Peaks führende Ionen-Molekül-Reaktion mit Chloranionen sowie ausgeprägte Chlorwasserstoffeliminierung beobachtet. Verbindungen mit Δ1,4-3-Keto-Struktur reagieren abweichend nach einem (M-2)-Mechanismus und aromatisieren leicht im Ring A. In den Kationenspektren erscheint als Peak höchster Massenzahl im allgemeinen das Molekülion. Durch Kombination beider Spektrenarten wird die Ermittlung des Molekulargewichts auch in solchen Fällen möglich, wo bei einer Spektrenart kein (M-1)- -bzw. M+-Peak auftritt.
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  • 96
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    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 144-148 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Durch Umsetzung von Acyl-isothiocyanaten mit sekundären Aminen entstehen über die leicht spaltbaren Acylthioharnstoffe 5 entsprechende 1,1-disubstituierte Thioharnstoffe 2. Von beiden Verbindungsklassen werden charakteristische Spektraldaten mitgeteilt.
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    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973) 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 98
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 211-220 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Whereas treatment of 2-butyloxy-, 2-pentyloxy- and 2-β-phenylethyloxy-4-arylazo-2-thiazolin-5-ones 1d-h with strong basic amines results in their rearrangement into 1-aryl- Δ2-1,2,4-triazolin-5-one-3-carboxylic acid derivatives 2, the 2-isobutyloxy, 2-(2-octyloxy)- and the 2-cyclohexyloxy-4-arylazo-2-thiazoline-5-ones 1i-n rearrange upon treatment with the same reagents into Δ2- 1,2,4-triazoline-5-thione-3-carboxylic acid derivatives 3. On the other hand, 1d-h,1 react with aromatic amines to give 1-aryl-2-alkoxy-1,2,4-triazole-3-carboxylic acid anilides 4a-i, via the loss of hydrogen sulphide. The phenylhydrazides 4j-l are obtained upon treatment of 1g, h,l with phenylhadrazine.Treatment of 4-arylidene-2-benzylmercapto-2-thiazolin-5-ones 6a-c with ammonia results in the formation of the thiohydantoin derivatives 7e, g. However, 6b, c react with phenylhydrazine to yield the phenylhydrazides 8b, c.The reaction of 6a-e with piperidine or morpholine involves to molecules of the reagent to yield 10a-d which are thermally cyclised to the thiazolone derivatives 11a-d.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 99
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 244-250 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of 5-hydroxybenzo[b]thiophene 1 with formaldehyde and some primary and secondary amines has been investigated. Whereas secondary amines give always the corresponding 4-aminomethyl-derivatives 2, the products with primary amines depend largely on the experimental conditions. The products, so obtained, have been characterized using micro- and spectral analyses.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 100
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 315 (1973), S. 274-288 
    ISSN: 0021-8383
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Der Reaktionsmechanismus der Methanol-Addition an Cyansäurearylester konnte aufgeklärt werden. Bei dieser Umsetzung entstehen neben Phenolen 2-Amino-4,6-diaroxy-1,3,5-triazine, 2-Amino-4,6-dimethoxy-1,3,5-triazin, Cyanursäure-trimethylester, Orthokohlensäure-teramethylester und Ammoniak. Kinetische Untersuchungen der Primärschritte  -  Addition des Methanols zu Kohlensäure-methylester-arylester-imiden und deren Weiterreaktion unter Bildung von Phenolen - mit Hilfe der UV-Spektroskopie führten zur Aufstellung eines kinetischen Modells, das eine Autokatalyse (Pseudo- 2. Ordnung) mit konkurrierender Folgereaktion (Pseudo- 1. Ordnung) beschreibt. Die Aktivierungsparameter und HAMMETT-Konstanten bestätigten die Annahme eines trimolekularen cyclischen Übergangszustandes. Durch Simulation auf einem Digitalrechner wurden die Konzentrations-Zeit-Kurven überprüft und eine Verbesserung des kinetischen Modells erreicht.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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