Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • 1995-1999  (10)
  • 1935-1939
  • 1995  (10)
  • Life and Medical Sciences  (7)
  • Chemical Engineering  (3)
Material
Years
  • 1995-1999  (10)
  • 1935-1939
Year
  • 1
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 41 (1995), S. 1251-1265 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: A comprehensive kinetic model developed for molecular weight calculations of ethylene axsnd α-olefin copolymerizations in the context of a terminal model accounts for multiple-type active centers of the catalyst, detailed elementary chemical reactions, and catalyst composition. The moments of copolymer chain distributions are defined considering molecular weights of comonomer units so that copolymer molecular weight averages can be directly calculated from those moments. A double Z-transformation is introduced for the derivation of differential equations of the moments. Model simulations are carried out based on ethylene and 1-butene copolymerizations in a gas-phase fluidized-bed reactor. Polydisperity of accumulated copolymer depends on catalyst composition and kinetic characteristics of the catalyst. For a catalyst with specified kinetic characteristics, the polydispersity depends on the mole fraction of each type of active center. For a catalyst with two types of active centers, the maximum polydispersity of copolymer occurs at 50 wt. % of the total copolymer if polydispersities of the copolymers generated at each active site are the same. Polydispersity of accumulated copolymer is sensitive to propagation reactions and chain transfer to hydrogen reactions. Differences in chain transfer to cocatalyst and monomers and in spontaneous deactivation rates for different types of active centers may play minor roles in controlling molecular weight development in the presence of hydrogen. This model can be used for catalyst composition design, simulation of commercial olefin copolymerization processes, and kinetic parameter estimation.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    AIChE Journal 41 (1995), S. 2356-2370 
    ISSN: 0001-1541
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Direct numerical simulations were used to study chemical selectivity in a series-parallel reaction scheme in a decaying, homogenous turbulent flow, where A, B, R, and S represent chemical species with R the principal product and S the secondary product. These simulations involve solution of the unsteady Navier-Stokes and mass conservation equations by a pseudo-spectral method in a 643 wavenumber domain. Reactants A and B were initially spatially segregated, corresponding to a nonpremixed system. The effect of turbulence Reynolds number and other physical parameters on selectivity was determined. Turbulence increases the formation of primary product R over byproduct S compared to the case of no fluid motion, as expected. It was also found that any mechanism promoting homogenization of reactants favors the formation of R, Whereas any mechanism sustaining segregation favors the formation of S.
    Additional Material: 19 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Stamford, Conn. [u.a.] : Wiley-Blackwell
    Polymer Engineering and Science 35 (1995), S. 1440-1454 
    ISSN: 0032-3888
    Keywords: Chemistry ; Chemical Engineering
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A combined finite element and finite difference approach has been developed to include the capability to model fluid and thermal transport for the filling of a die cavity by a fluid that has differing sensitivities to extensional and shear deformation rates. This is referred to here as a dual viscosity fluid. For the case of mildly convergent or divergent quasi two-dimensional flows, a viscosity model is described that has such a dual-viscosity character and in which shear and extension rate sensitivities are nearly separated. Filling simulation results can be generated rapidly in a modest computational environment. The range of cavities and molding materials that may be modeled realistically is widened by the inclusion of a dual viscosity model. The effect of wall quenching (freezing) increased with decreasing filling rate, while the effect of dual viscosity increased with increasing filling rate.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 241 (1995), S. 439-450 
    ISSN: 0003-276X
    Keywords: Golgi ; TGN ; Inflammation ; Acute phase response ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: During the acute phase response to inflammation, the Golgi apparatus of rat hepatocytes processes an increased quantity of glycoproteins, in the form of acute phase reactants.Methods: The compartmental organization of the hepatocyte Golgi of control and 24 hour inflamed rats was studied, using transmission electron microscopic techniques, including cytochemistry, to detect nicotinamide adenine dinucleotide phosphatase (NADPase), thiamine pyrophosphatase (TPPase), and cytidine monophosphatase (CMPase) activity.Results: In inflamed rats, individual Golgi stacks were enlarged, but retained their organization into four compartments:1) a phosphatase negative, perforated cis-element, 2) two mid-saccules which sometimes were positive for NADPase, 3) one or occasionally two NADPase and TPPase positive trans-saccules, and 4) a tubulovesicular trans-Golgi network (TGN) which was NADPase reactive and contained a spotty TPPase reaction product. Two of these compartments were noticably altered in response to inflammation. The two mid-saccules were consistently and uniformly dilated. The TGN was altered to the point of being difficult to recognize and had acquired CMPase reactivity. In control rats the TGN consisted of anastomosing tubules forming cage-like structures; secretory granules containing lipoprotein particles pinched off from these. In inflamed rats, most of the cage-like TGN structures had been replaced with an extensive vesicular syncytium which produced secretory granules with a granulofilamentous content.Conclusions: In hepatocytes from inflamed rats an apparent switch had occured in the type of secretory material processed by the Golgi apparatus. Furthermore, the inflammation-induced increase in the size of individual Golgi stacks apparently was not due to a parallel increase in size of all Golgi saccules. Rather, saccules within given Golgi compartments responded in a characteristic and specific manner to the increase in glycoprotein processing that occurs during inflammation. © 1995 Wiley-Liss, Inc.
    Additional Material: 17 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    The @Anatomical Record 241 (1995), S. 563-578 
    ISSN: 0003-276X
    Keywords: Substantia nigra ; Basal ganglia ; Cytoarchitecture ; Light microscopy ; Electron microscopy ; Opossum ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Medicine
    Notes: Background: The substantia nigra has been divided into three subdivisions. However, the cytoarchitecture of one of these subdivisions, the pars lateralis (SNI), has not been previously examined in detail at the light and electron microscopic levels in any species. In the adult opossum, the three nigral subdivisions can be easily distinguished as distinct, rostrocaudally oriented cell groups separated by neuron-free zones. Thus it was possible to determine the boundaries of the SNI unambiguously. This report covers the results of an examination of the morphology and organization of the SNI in the opossum.Methods: Material from 13 opossums was used for this study. Eight of the animals had been previously stained for Nissl substance (n=4) or impregnated by the Golgi technique (n=4). The remaining five animals were prepared for electron microscopic studies using standard procedures.Results: Two cell types were identified on the basis of morphological differences, small and medium-large neurons. Small neurons (10-18 μm long axis) have large nuclei with moderate amounts of heterochromatin and a thin rim of cytoplasm. They have long (up to 500 μm), spine-free dendrites. Medium-large neurons (18-54 μm long axis) have rounded nuclei with electron-lucent nucleoplasm. Few indentations of the nuclear envelope were observed. The surrounding cytoplasm has dense arrays of organelles. Nissl bodies are particularly prominent in the form of pyramids with their bases at juxtanuclear positions and their apices directed toward emerging dendrites. Dendrites of medium-large neurons are long (some〉1 mm in length), are primarily oriented in the frontal plane, and extend along the dorsal surface of or into the cerebral peduncle. Some cells have dendrites that are moderately spinous, whereas other neurons possess sparsely spinous dendrites. Relatively few synaptic profiles are observed to contact somata and proximal dendrites.Conclusion: This report provides added morphological support for the idea that the SNI is a distinct subdivision of the substantia nigra, a distinction previously made on the basis of the physiologically characterized relationship between the lateral substantia nigra and orienting behaviors and seizure-related function. © 1995 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Journal of Morphology 226 (1995), S. 47-77 
    ISSN: 0362-2525
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Intratendinous ossification (tenostosis; Tendo ossificans) is a distinct structural form feature of the avian musculoskeletal system with different definitions in terms of morphogenesis, resultant morphology, and functional role(s). Interpretation of these structural elements and their pattern(s) among avian taxa at different systematic levels is reviewed with regard to age-related changes in tendon, form features in avian phylogeny, and adaptive features in biomechanics and kinematics of locomotion. Specific examples of patterns in the musculoskeletal elements of the head and hyolingual system, axial (vertebral) system, and the limbs in several avian taxa are given. A series of questions is formulated as a prospectus for further study. © 1995 Wiley-Liss, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 16 (1995), S. 97-105 
    ISSN: 0197-8462
    Keywords: atrioventricular block ; heat coagulation ; reversible and irreversible block ; catheter antenna ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: The use of microwave energy for ablation of the atrioventricular (AV) junction was examined in open-chest dogs. Using a specially designed microwave catheter and a 2450 MHz generator, microwave energy was delivered to the AV junction according to one of two protocols. In protocol 1, increasing amounts of energy were delivered until irreversible AV block occurred. In protocol 2, only two applications of energy were used, one at low energy and the other at an energy found to be high enough to cause irreversible AV block. Each dog received between one and six applications of microwave energy. The amount of energy delivered per application ranged from 25.6 to 311.4 J. No AV block was seen at 59.4 ± 28.3 J. Reversible AV block was seen with an energy of 120.6 ± 58 J. Irreversible AV block was seen at 188.1 ± 75.9 J. Irreversible AV block could be achieved in each animal. There was no difference in the energy required to cause irreversible AV block between the two protocols. The tissue temperature measured near the tip of the microwave catheter was correlated with both the amount of energy delivered and the extent of AV block caused. Histologic examination demonstrated coagulation necrosis of the conduction system. Microwave energy is a feasible alternative energy source for myocardial ablation. Since tissue damage is due exclusively to heating and the resulting rise in temperature can be measured, microwave energy may have advantages over currently existing energy sources in terms of both titrating delivered energy and monitoring the extent of tissue destruction. © 1995 Wiley-Liss, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 163 (1995), S. 532-537 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Hepatocyte growth is regulated by various growth factors, including epidermal growth factor (EGF) and insulin. Recently, several additional peptide hormones have been shown to stimulate growth of hepatocyte only in the presence of EGF or insulin and are thus termed secondary mitogens. Gastrin regulates growth of normal and neoplastic gastrointestinal tissues, but the effect on growth of hepatocyte is unknown. We examined the effect of gastrin on growth of a normal mouse hepatocyte (NMH) line established in our laboratory. Effect of gastrin-17 (G-17) (10-8 to 10-6 M) on growth of NMH cells was examined in either the presence or absence of EGF in the culture medium. Growth of NMH cells was evaluated by incorporation of either bromodeoxyuridine (BrdU) or 3H-thymidine and by counting cells. Presence of a cell-surface receptor for G-17 was determined by Scatchard analysis using 125I-G-17. In the presence of EGF, gastrin stimulated growth of NMH cells; in the absence of EGF, gastrin did not affect growth. The stimulatory effect of gastrin on NMH cells was blocked by JMV 320, a CCK-B type receptor antagonist. NMH cells possess a single, high affinity binding site for gastrin (Kd = 1.2 nM); EGF increased the gastrin binding capacity compared to non-treated cells (3.5 ± 0.4 vs. 2.2 ± 0.6 fmol/106 cells). G-17 stimulated growth of NMH cells through a single high affinity receptor for G-17 which pharmcologically appears to be the CCK-B type only in the presence of EGF and thus can be considered a secondary mitogen. © 1995 Wiley-Liss, Inc.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Cellular Physiology 165 (1995), S. 172-176 
    ISSN: 0021-9541
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Alterations in the activity of phospholipase C (PLC) are thought to be the primary intracellular events leading to pancreatic acinar cell exocytosis of zymogen granules. When multiple hormones, each of which may stimulate different signal transduction pathways, bind to cell surface receptors, the cell must integrate these signals into a common response through communication (cross-talk) among intracellular second messengers. We show that cholecystokinin (CCK) induces amylase secretion from AR4-2J pancreatic acinar cells via stimulation of PLC activity. Secretin indirectly stimulated the PLC pathway through cross-talk of the activated cAMP pathway to potentiate the CCK-stimulated amylase secretion. Therefore, secretin potentiated the acinar cell secretory response to CCK by cAMP-mediated cross-talk with the PLC signal transduction pathway. © 1995 Wiley-Liss Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 0749-503X
    Keywords: Saccharomyces cerevisiae ; genome sequencing ; chromosome VII ; RAD54 ; ACE1 ; CUP2 ; PMR1 ; SSC1 ; RCK1 ; AMS1 ; CAL1 ; CDC43 ; SNF2 ; STH1 ; NPS1 ; ECC1 ; Life and Medical Sciences ; Genetics
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology
    Notes: We present DNA sequence data from a 35 364 bp region on the left arm of chromosome VII of Saccharomyces cerevisiae. This region contains 19 open reading frames (ORFs). ORF G1821 corresponds to the RAD54 gene involved in repair and recombination (Emery et al., 1991). G1810 is identical to the ACE1 gene sequenced by Szczypka and Thiele (1989), required for copper-inducible transcription of the CUP1 gene. The first 693 bp on the minus strand represent part of the 3′ non-coding region from the P-type ATPase gene PMR1, previously sequenced by Rudolph et al. (1989), which is identical to the SSC1 gene (Smith et al., 1988). G1845 corresponds to the RCK1 protein kinase gene from S. cerevisiae (Dahlkvist and Sunnerhagen, 1994). G1861 is almost identical to the α-mannosidase gene AMS1 reported by Yoshihisa and Anraku (1989) and G1864 has 100% identity with the yeast CAL1 gene (Ohya et al., 1989)/CDC43 gene (Johnson et al., 1990) which is involved in control of cell polarity. This region also contains a gene specifying a Leu-tRNA precursor and a remnant of a tau element. ORF G1880 shows some similarity to the S. cerevisiae SNF2, STH1 and NPS1 genes and to the human ERCC1 gene. A 93 bp region shows similarity to yeast EST sequenced by Burns et al. (1994). None of the remaining ORFs has similarity to any sequence within the databases screened. The sequence described in this paper has been deposited in the EMBL Data Library under the Accession Number Z48618.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...