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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 5318-5324 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of the hole density in carbon-doped GaAs and AlxGa1−xAs as a function of the annealing temperature are presented. It is shown that after sample annealing at low temperatures (T〈550 °C), the hole concentration increases in all samples doped ≥1×1019 cm−3 with a simultaneous decrease in the hole mobility. However, sample annealing at higher temperatures (T(approximately-greater-than)600 °C) results in a reduction of the hole concentration in all samples doped with carbon at concentrations higher than ≈5×1019 cm−3. The reduction in hole concentration is also accompanied by an increase in lattice parameter of the carbon-doped epilayer. The observed changes in the electrical and microstructural properties are explained in terms of two different mechanisms: (1) the passivation of carbon acceptors by the incorporation of hydrogen during growth, and (2) the change in the lattice site location of carbon atoms upon annealing. Direct determination of the lattice site location of carbon in samples doped ≥5×1019 cm−3 showed that the fraction of interstitial carbon after annealing at T(approximately-greater-than)600 °C is at least 70% higher than in the as-grown samples.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Muir-Torre syndrome (MTS) is an autosomal dominant disorder characterized by the presence of at least one sebaceous gland tumour and a minimum of one visceral malignant tumour. Recently, microsatellite instability (MSI) has been detected in the tumours of patients with MTS and germline mutations of the hMSH2 and hMLH1 mismatch repair genes have been detected in some patients with this syndrome. To determine if the tumours of patients with MTS have widespread genomic instability and whether loss of heterozygosity (LOH) in the chromosomal regions containing hMSH2 and hMLH1 is detectable. MSI and LOH were examined at 10 dinucleotide repeats on chromosomes 2p, 3p, 5q, 9p, 17p and 18q. Data were obtained from six sebaceous gland tumours and two adenocarcinomas of the colon from three patients of two Muir-Torre families. MSI was detected at more than half of the loci tested in all sebaceous tumours examined. In addition, there was LOH at D2S119 in one sebaceoma and one sebaceous carcinoma from one patient. The colon carcinomas from two patients showed MSI at five of the 10 loci analysed. These results show that widespread MSI is a feature of tumours in patients with MTS. In addition, the finding of LOH at D2S119, a marker located in the vicinity of hMSH2, in sebaceous tumours of one patient indicates that this gene may have a pathogenetic role in this patient.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 1745-1747 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Amorphous Ni-Ti alloys were synthesized by producing nanoscale amorphous Ni-Ti particles and compacting these powders, in situ, in a high vacuum environment. X-ray diffraction measurements revealed that crystallization occurs in these alloys in the temperature range 450–550 °C, although measurements of electrical resistivity and heat release showed that other relaxation processes occur at lower temperatures. The Vicker's hardness of these alloys is ≈350 kg/mm2. The results are discussed in terms of interparticle or grain boundaries in the amorphous alloy.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 3832-3839 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Measurements of Bi and Au diffusion in nanocrystalline (n-) Cu and of Bi in copper thin films have been performed. The results show that (a) the diffusivity in n-Cu can be enhanced by more than ten orders of magnitude with respect to that in single-crystalline Cu. (b) Grain boundaries in n-Cu have a higher free energy and volume than conventional grain boundaries. (c) Relaxation can take place in n-Cu. (d) Diffusion measurements in n-materials represent a convenient means to determine thermodynamic properties such as grain boundary energies, solubilities, heats of segregation, and solution.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Carcinogenesis in the human colon is associated with a marked increase in the tissue content of the urokinase-type plasmmogen activator (u-PA). This study was performed to determine the type of cells responsible for the u-PA increase in carcinomas of the colon and in their precursor lesions, the adenomas, by immunohistological evaluation applying monoclonal antibody 3689 directed to the β-chain of u-PA.Normal intestinal mucosa (n= 17) showed hardly any staining of u-PA, but some lamina propria cells were faintly positive. Carcinomas (n= 17) and adenomas (n= 16) showed a considerable and comparable staining intensity of u-PA in neoplastic columnar epithelial cells, and this staining was found to be diffuse and cytoplasmic. In a majority of the neoplastic tissues the u-PA staining was found to be patchy and not related to known risk markers of malignancy such as dysplasia in the adenomas, or to prognostic determinants such as Dukes' classification or differentiation in the carcinomas. The observation of strong u-PA positive lamina propria cells in adenomas but infrequently observed in normal mucosa and carcinomas was noteworthy. u-PA staining intensity of the tissue sections was found to correlate well with the u-PA antigen level in the tissue extracts determined by ELISA (r= 0.52, P= 0.0001) but poorly with the u-PA activity determined enzymatically (r= 0.28, P= 0.05).In conclusion, the u-PA increase in neoplasia of the human colon can be attributed to an increased diffuse cytoplasmic content of u-PA in neoplastic columnar epithelial cells.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 133 (1995), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary Epstein-Barr virus (EBV) is a gamma DNA herpes virus which is thought to play a part in the pathogenesis of some non-Hodgkin's lymphomas in individuals with or without immunodeficiency. We investigated 16 lymph nodal and 12 cutaneous anaplastic large cell lymphomas (ALCLs) (Ki-1 +), all of which were in patients without immunodeficiency, for the presence of EBV genomes. The highly sensitive polymerase chain reaction (PCR) technique was employed for detection of viral DNA in extracts from formalin-fixed, paraffin-embedded tissue sections. In addition, we performed radioactive and non-radioactive in situ hybridization (ISH) for localization of EBV at the single cell level. EBV-DNA was demonstrated by PCR in five cases of nodal ALCLs (31 %). All cutaneous ALCLs were negative. EBV-encoded small nuclear RNAs (EBERs) could be identified by ISH in the tumour cells of one of the five EBV-DNA-positive patients. Our results further support the concept that EBV may be involved in the development of a proportion of nodal ALCLs, hut not in cutaneous ALCLs.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1600-0560
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Fluorescence in situ hybridization (FISH) to sections of formalin-fixed paraffin-embedded archival tissues allows the detection of gene or chromosome copy number changes in interphase cell nuclei within the histological context and thus may be of particular interest in tumor pathology. In this report, we describe the application of FISH to thick (15 μn) paraffin sections of 7 primary cutaneous malignant melanomas. A chromosome 7-specific centromeric DNA probe was used to detect numerical aberrations of chromosome 7. By optical sectioning using confocal laser scanning microscopy (CLSM) only complete, uncut interphase cell nuclei were scored. The mean percentage (±SEM) of melanoma cell nuclei with three hybridization spots was (20.7±2.8)%; (6.8±1.0)% of nuclei showed one spot and (5.0±1.2) % four or more spots. The frequency distribution of spot numbers among melanoma cell nuclei and normal keratinocyte nuclei was significantly different (χ2= 176.8, df= 5, p〈0.001). Trisomy 7 was detected in all 7 cases analyzed, mostly associated with monosomy 7 or polysomy 7. The approach used in our study and the data obtained could be useful for further studies designed to investigate a possible involvement of chromosome 7 in melanocytic tumor progression.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 136 (1997), S. 0 
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Interpretation of molecular analyses of cutaneous lymphoid infiltrates may be difficult because a heterogeneous group of cells is usually present within the neoplasms. Extraction of DNA from tissue sections does not provide exact information about which cell population has been analysed. We present a laser microscope system that allows selective molecular analysis of single cells or small groups of cells in cases of cutaneous lymphoma. An ultraviolet (UV)-laser microscope system (PALM, Wolfratshausen, Germany) was used to isolate particular populations of cells from a routinely processed specimen of a cutaneous follicular lymphoid proliferation. Using the UV-laser beam, a circle was cut around a target germinal centre in order to separate it from neighbouring tissues and to isolate a pure population of germinal centre cells. Isolated cells were scraped off with a micromanipulator and placed in a proteinase-K solution. DNA was extracted and amplified by the polymerase chain reaction (PCR) technique. Analysis of immunoglobulin JH gene rearrangement showed a distinct monoclonal band. In a second phase, using the same procedure in the same specimen, mantle zone cells around a germinal centre and single interfollicular B lymphocytes were isolated for PCR analysis of immunoglobulin JH gene rearrangement. In this population of cells, no clonality could be detected. This new technique allows the selective elimination of undesired cells and tissue from cutaneous neoplasms. By destruction of unwanted tissues with laser-beam energy a contamination-free sample is obtained. Analysis of isolated cells in our case demonstrated a clonal rearrangement derived from germinal centre cells and not from other B lymphocytes in the specimen, confirming the diagnosis of cutaneous follicle centre lymphoma. The method described has exciting implications for dermatology and dermatopathology, allowing precise correlation of morphological features with findings by molecular genetics.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    European archives of oto-rhino-laryngology and head & neck 231 (1981), S. 736-738 
    ISSN: 1434-4726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Based on the criteria of long survival and recurrence rates after an observation period of maximally 4 years, the recent results of endolaryngeal laser resection of malignomas of stage Tis to stage T2 are reported. Recurrence rates after laser resection of T1 tumors as well as many cases of T2 tumors seem to be comparable to those after standard surgical treatment or radiotherapy. In Tis tumors, treatment by evaporation of pathological tissue can be applied only, if by previous biopsy and histological examination an infiltrative tumor growth can be safely excluded; in all other cases additional resection is necessary.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1432-2323
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé La détermination préopératoire du stade du cancer gastrique a une place importante d'abord dans chaque bilan et ensuite pour la mise en route du protocole thérapeutique. A présent, il faut considérer le 《staging; comme bien plus que la simple détermination de l'infiltration pariétale de la lésion, i.e. le stade 《T》, de l'état des ganglions, la catégorisation 《N》, et de la présence ou non des métastases à distance, ou le stade 《M》, selon la classification de l'UICC. De plus en plus, il faut inclure l'évaluation des facteurs pronostiques tels que la RAS-protéine, le gène suppreseur p 53, les récepteurs des facteurs de croissance, les molécules d'adhésion cellulaire, des facteurs protéolytiques, et des antigènes en rapport avec la prolifération. Une amélioration de l'évaluation de l;état des ganglions (classification 《N》) est possible grâce aux techniques modernes informatisées. Le 《staging》 conventionnel fait appel à l'endoscopie conventionnelle et l'échoendoscopie, l'échographie conventionnelle, la tomodensitométrie et l'imagerie par résonance magnétique. D'autres progrès sont attendus de la laparoscopie avec échographie per laparoscopie et de l'analyse du liquide de lavage péritonéal y compris la détection des cellules tumorales libres par l'immunohistochimie. Les facteurs pronostiques biologiques les plus promettants sont discutés.
    Abstract: Resumen La estadificación preoperatoria del cáncer gástrico juega un papel crucial en la aplicación de protocolos de tratamiento multimodal. En los tiempos actuales la estadificación trata de ir más allá de la simple evaluación de la infiltración tumoral de la pared del órgano, o sea el estado T de la condición de los ganglios (categoría N) y de la presencia de metástasis distantes (estado M), en concordancia con los criterios de la UICC. La estadificación incluye, en términos de la oncología quirúrgica moderna, más y más la evaluación de los denominados factores de pronóstico, tales como la proteína RAS, el gen supresor T53, los receptores de fetor de crecimiento, las moléculas de adhesión celular, factores proteolíticos y antígenos asociados a la proliferación. Además, ahora la evaluación del estado ganglionar es posible mediante sofisticados programas de computador. En el presente artículo se discute la estadificación convencional del cáncer gástrico utilizando endoscopia y sonografía, ultrasonido convencional, escanografía computadorizada e imagenología por resonancia magnética. Posibles avances en cuanto a estadificación en centros oncológicos deberán incluir la laparoscopia quirúrgica, la ultrasonografía laparoscópica y la evaluación meticulosa de un lavado peritoneal orientado a la detección immuno-histoquímica de células tumorales libres. También se discuten brevemente los factores de pronóstico de naturaleza de biología tumoral que aparecen más promisorios en la valoración del cáncer gástrico.
    Notes: Abstract Preoperative staging of gastric cancer plays a crucial role in every multimodal treatment protocol. At present, staging intends to be far more than evaluation of the depth of tumor infiltration into the organ wall, that is, T stage, nodular status (N category), and the presence of distant metastases (M stage) according to UICC criteria. In modern surgical oncology it includes more often the evaluation of prognostic factors such as the RAS-protein, p53 tumor suppressor gene, growth factor receptors, cell adhesion molecules, proteolytic factors, and proliferation-associated antigens. Furthermore, evaluation of nodular status is possible by sophisticated computer programs. The conventional staging of gastric cancer using endoscopy and sonography, conventional ultrasonography, computed tomography, and magnetic resonance imaging is discussed. Possible improvements of staging in oncologic centers should include surgical laparoscopy, laparoscopic ultrasonography, and meticulous evaluation of an abdominal lavage including immunohistochemical detection of free tumor cells. The most promising tumor biology-related prognostic factors in gastric cancer are briefly discussed.
    Type of Medium: Electronic Resource
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