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  • 1
    ISSN: 1432-1130
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Some YBa2Cu3O7-δ films and heterostructures prepared by Chemical Vapor Deposition (CVD) were analyzed in our laboratories by EPMA-EDX or WDX, RBS, SNMS and AES. It was found that in some cases the results of composition analysis can significantly deviate from each other. At least two main reasons for these deviations exist: the different lateral resolution and the application of different reference samples for the calibration.
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  • 2
    ISSN: 1433-0563
    Keywords: Key words Renal cell cancer • Vena cava inferior • Neoplastic extension • Thrombosis • Prognostic factors • Multiparameter analysis ; Schlüsselwörter Nierenzellkarzinom • Kavathrombus • Prognosefaktoren • Mehrparameteranalyse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Die Propagation eines Tumorthrombus in die V. cava inferior bzw. das rechte Atrium in Assoziation mit einem Nierenzellkarzinom wird bei 4–10 % der betroffenen Patienten beobachtet. Die Frage nach einer von anderen Tumorcharakteristika unabhängigen prognostischen Bedeutung des Kavathrombus für das Langzeitüberleben der Patienten wird trotz einer Reihe früherer Untersuchungen noch immer kontrovers diskutiert. Es wurde daher in der vorliegenden Untersuchung der klinische Verlauf von 53 Patienten mit Nierenzellkarzinom und Kavathrombus mit dem einer Kontrollgruppe, bestehend aus 47 Patienten mit Nierenzellkarzinom und ohne den Nachweis eines Kavathrombus, korreliert (Nachbeobachtungszeit: 1–154 Monate). Bei einem durchschnittlichen Langzeitüberleben von 32 bzw. 35 Monaten für Patienten mit Nierenzellkarzinom mit und ohne Nachweis eines Kavathrombus konnte uni- und multivariat weder für die Propagation eines Tumorthrombus in die V. cava inferior (p = 0,391) noch für die kraniale Thrombusausdehnung (p = 0,158) – auch im Falle einer rechtsatrialen Propagation – ein prognostischer Wert ermittelt werden.
    Notes: Summary The independent prognostic value of neoplastic extension of renal cell cancer (RCC) into the vena cava inferior has been the subject of several investigations reported to date. However, the use of vena cava thrombosis as an independent prognosticator of a patient's long-term survival is still debated. We have therefore correlated the clinical course of 53 patients with RCC and vena cava thrombosis with a control group consisting of 47 patients with renal cell tumors without vena cava thrombosis (follow-up: 1–154 months). The median long-term survival of patients with and without vena cava thrombosis was 32 and 35 months, respectively. Neither the propagation of the tumor into the vena cava (P = 0.391) nor the cranial extension of the thrombosis (P = 0.158) – even in case of propagation into the right atrium – could be identified as parameters of any prognostic value during univariate or multivariate statistical analysis.
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  • 3
    ISSN: 1432-0649
    Keywords: 66.70. + f
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We investigated the anisotropic thermal conductivity in pyrolytic graphite by thermoreflectance. A laser-heated circular spot on a surface perpendicular to the planes developed into an elliptical temperature distribution which was recorded by a raster scanning technique at modulation frequencies ranging from 600 Hz to 100 kHz. The ratio of in-plane and perpendicular thermal conductivity was determined by fitting the phase of the temperature data with an analytical model, and was found to decrease with increasing modulation frequency. Highest conductivity values were considerably smaller than previously published data based on steady-state measurements. The frequency dependence and additional features in the phase profiles at high frequencies are discussed in view of sample surface preparation and the local nature of the thermoreflectance measurement.
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  • 4
    ISSN: 1432-0649
    Keywords: PACS: 42.65 H; 42.30; 07.07.D
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. In this article, we demonstrate the capability of a two-beam coupling photorefractive optical novelty filter of detecting changes in the amplitude or phase of optical images. These changes may either be continuous or discrete in time. The performance of the two-beam coupling novelty filter is investigated and expressions for the output contrast corresponding to phase and amplitude changes based on a novel, simple interference model of two-beam coupling are derived. These expressions are verified by experimental results on the novelty contrast, revealing that the amplitude contrast is not described correctly by the commonly accepted coupled-wave theory. The novelty filter was applied to the detection of temporally continuous phase changes provided by a gas flow and moving microscopic objects. A novel scheme for image subtraction is also demonstrated, showing the novelty filter’s ability to detect temporally discrete changes.
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  • 5
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Recent results demonstrate an emerging role for paclitaxel in patients with urothelial-tract cancer and in patients with testicular cancer. Yielding response rates in the range of 40–50% as a single agent, paclitaxel is one of the most active drugs in metastatic bladder cancer. Ongoing trials of paclitaxel combination chemotherapy with cisplatin or cisplatin and ifosfamide demonstrate substantial objective remission rates above 70% and, in addition, a high range of complete responses. Thus, paclitaxel appears to be an important drug when used as part of first-line combination chemotherapy for metastatic bladder cancer. Ongoing clinical trials focus on the combination of paclitaxel with cisplatin, ifosfamide, gemcytabine, and carboplatin. Furthermore, paclitaxel administration has been demonstrated to be easily applicable to patients with reduced renal function, requiring no dose reduction and producing no increase in toxicity. Future strategies will have to compare the most active paclitaxel combination regimen with first-line MVAC (methotrexate, vinblastine, adriamycin, cisplatin) chemotherapy. Finally, the role of paclitaxel combination regimens needs to be explored in the adjuvant and neoadjuvant setting in patients with bladder cancer. In testicular cancer, paclitaxel has initially been tested in patients with cisplatin-refractory disease. Among 4 consecutive trials involving a total of 83 patients a response rate of 26% has been observed using dose schedules varying from 3-h to 24-h infusions and doses ranging from 175 to 250 mg/m2. The major toxicities of paclitaxel include neutropenia, neurotoxicity, and fatigue syndrome. Currently, combinations of paclitaxel with cisplatin ± ifosfamide are used as first- or second-line salvage therapy in patients with relapsed metastatic testicular cancer. The German Testicular Cancer Study Group uses a paclitaxel (Taxol, ifosfamide, cisplatin; TIP) combination regimen as salvage treatment. Following the TIP regimen and the application of granulocyte colony-stimulating factor (GCSF), peripheral blood stem cells (PBSC) are harvested and the patients subsequently receive high-dose chemotherapy with PBSC rescue. Since only a few drugs have demonstrated substantial activity in cisplatin-refractory disease, paclitaxel will be used in early salvage strategies and, possibly, as first-line chemotherapy as a part of platinum-based combination regimens in patients with testicular cancer. Further trials confirming the important role of paclitaxel in this highly curable malignancy and a thorough investigation of its acute and long-term toxicity will be the future tasks.
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  • 6
    ISSN: 1433-8726
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Paclitaxel, a natural anticancer drug, has gained widespread acceptance as an active broad-spectrum antitumor agent, including its use in urological malignancies, particularly urothelial tract cancer and testicular cancer. The mechanism of action, based on the premature stabilization of the microtubule assembly with disruption of the cytoskeletal framework, is completely different from those of DNA-damaging agents, e.g., cisplatin and ifosfamide. As a single agent, paclitaxel is one of the most active drugs in metastatic bladder cancer, with an overall response rate of 40–50% being obtained in previously untreated patients. These promising single-agent results have prompted the use of combination regimens including, in particular, cisplatin and paclitaxel. A high degree of activity for the cisplatin-paclitaxel combination as reflected by responses in 50–80% of patients, including a substantial number of complete responses (〉30%), has been identified. The role of other agents such as vinorelbine, methotrexate, 5-fluorouracil, or ifosfamide as additions to this two-drug combination currently remains open. The combination of paclitaxel plus ifosfamide or vinorelbine in the absence of a platinum derivative has yielded rather disappointing results. Of particular interest may be the combination of paclitaxel and carboplatin. Both drugs can be given to patients with impaired renal function. Overall response rates of 45–60% have been reported in phase II studies. The so-called platelet-sparing effect of paclitaxel given in combination with carboplatin has resulted in a surprisingly low frequency of myelotoxicity, particularly thrombocytopenia. The combination of paclitaxel with carboplatin is being compared in an ongoing trial against the current standard MVAC regimen (methotrexate/vinblastine/Adriamycin/cisplatin) in patients with metastatic disease. Furthermore, the activity of paclitaxel-based combinations is currently being explored in the neoadjuvant setting in phase II studies, and the potential for the combination with the other new promising agent – gemcitabine – will be evalutated in a phase I setting. In prostate cancer, estramustine phosphate is widely used as palliative treatment for patients with hormone-refractory disease. In vitro synergistic activity has been observed between estramustine and paclitaxel in prostate-cancer cell lines, although paclitaxel has not demonstrated single-agent activity in patients with hormone-refractory prostate cancer. In clinical trials the combination of the two agents was associated with increased gastrointestinal toxicity. The addition of etoposide as a third drug has yielded prostate-specific antigen (PSA)-response rates of 〉50%, but data on quality of life and survival time have not been reported for these combinations. A true clinical role for paclitaxel in prostate cancer has therefore not been established. Paclitaxel has finally demonstrated single-agent activity in relapsed and/or cisplatin-refractory testicular cancer in recent phase II trials, indicating different mechanisms of resistance to cisplatin and paclitaxel. These results have formed the rationale for the introduction of paclitaxel as part of combination chemotherapy regimens in patients with relapsed but chemosensitive testicular cancer. Preliminary results demonstrate that paclitaxel can be safely included into these conventional-dose combination regimens. When it is used prior to high-dose chemotherapy, sufficient numbers of peripheral blood stem cells (PBSCs) for high-dose therapy can be collected. The final role of paclitaxel in risk-adapted chemotherapeutic strategies in testicular cancer is not defined, but it appears that paclitaxel-based combinations can achieve a substantial response rate in patients with relapsed disease.
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  • 7
    ISSN: 1433-8726
    Keywords: Key words Testicular cancer ; Metastatic disease ; Conventional chemotherapy ; High dose chemotherapy ; New drugs ; Toxicity of chemotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The current aims of chemotherapy in metastatic testicular cancer are to reduce treatment-related toxicity in patients with “good-prognosis” metastatic disease without compromising the efficacy and to improve treatment results in “poor-prognosis” patients according to the IGCCCG classification by the use of more dose-intensive regimens. Three cycles of PEB chemotherapy, consisting of cisplatin, etoposide, and bleomycin, remain the standard treatment for good-prognosis patients despite a number of randomized studies trying to avoid the toxicity of bleomycin or to abandon cisplatin-associated side effects by substitution with the less toxic analogue carboplatin. In patients with intermediate- and poor-prognosis criteria, four cycles of PEB given at 3-weekly intervals are considered routine treatment. The role of high-dose chemotherapy with peripheral blood stem-cell (PBSC) transplantation (HDCT) is currently being investigated for patients who initially present with poor-prognosis metastatic disease and for patients with relapse after previous chemotherapy. Favorable results with long-term survival rates of approximately 75% have been achieved with up-front sequential HDCT in a phase I–II trial of the German Testicular Cancer Study Group (GTCSG) in such patients. A randomized phase III trial comparing conventional dose chemotherapy (4× PEB) with HDCT (2× PEB + 2× HD-CEC) was initiated as a United States intergroup trial in 1996. In patients with relapsed disease, conventional salvage chemotherapy results in only an approximately 20% long-term survival rate. Particularly, primary mediastinal disease and chemotherapy refractoriness represent variables associated with a very poor outcome. HDCT is also employed in relapsed patients to improve the long-term outcome. Long-term toxicity of treatment has become an important issue due to the large group of patients with metastatic disease now being cured with modern treatment strategies. The cumulative dose of cisplatin applied has been identified as a major risk factor for the development of many types of late toxicity. Despite the major advances made in the last 20 years, evaluation of the role of HDCT in both first-line and salvage treatment, investi- gation of new cytotoxic agents in refractory patients, and assessment of the long-term toxicities are major tasks that remain to be addressed in controlled clinical trials.
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Aquatic sciences 57 (1995), S. 106-118 
    ISSN: 1420-9055
    Keywords: Benthos ; fish ; vertical distribution ; predation risk ; selective fishing ; Lake Constance
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract To compare the vertical distributions of benthos and fish species of Upper Lake Constance (Bodensee), 552 benthos samples were taken with an Auerbach grab at four transects (10–250 m). An additional 54 samples (1–10 m) were collected elsewhere. Complementary data was taken from the literature. In winter, most fish feed on benthos, mainly chironomids, but in summer less than 5% do so. Formerly the bottom gill-netting aimed mainly at catchingCoregonus pidschian, but it now aims atPerca fluviatilis. Contrary to expectation, in winter the greatest abundance ofP. fluviatilis is much deeper (55 m) than that of its preferred food, i.e. chironomids (〈20 m). Comparably,C. pidschian also stayed deeper than its main food source (chironomids and mollusks).Lota lota, Salvelinus profundus andS. alpinus — unlike the unwanted cyprinids — also stay or stayed deeper than the attractive chironomids. It is argued that the fish reduce their “predation risk”, i.e. the risk of being gillnetted in the upper 50 m, by “selecting” the deeper less dangerous, but also less food-abundant habitat. Balancing predation risk against food abundance may have led to “survival of the deepest”.
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  • 9
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 70 (1997), S. 1113-1115 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We have grown by atomic layer epitaxy CdTe/MnTe tilted and serpentine superlattices. These heterostructures are formed by depositing in the step-flow growth mode fractional monolayer superlattices (CdTe)m(MnTe)n, with p=m+n∼1, onto 2 °A and 2 °B Cd0.95Zn0.05Te vicinal substrates. Transmission electron microscopy images reveal a good in-plane CdTe/MnTe separation and a uniform short-range superlattice period. The very existence of those superlattices imply that Te-based vicinal surfaces present a regular array of monomolecular steps, with no important step meandering and no step bunching. © 1997 American Institute of Physics.
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  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 81 (1997), S. 2966-2972 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A photothermal microscope that provides micrometer lateral and submicrometer depth resolution was designed. Thermal conductivity measurements with modulation frequencies up to 12 MHz on single grains in polycrystalline diamond demonstrate its lateral resolution power even for a highly conducting material. Measured conductivities strongly depend on the averaged volume and values up to 2200 W/mK are found in the high frequency limit where the properties inside a grain are sampled. The capability of the instrument to measure thermal parameters on thin films is demonstrated for gold films evaporated on quartz with a thickness ranging from 20 to 1500 nm. Measurements reveal a strong thickness dependence for both thin film conductivity and the contact resistance between film and substrate. Thermal conductivity decreases monotonically from 230 to 30 W/mK whereas the contact resistance rises from 2×10−7 to 8×10−6 m2K/W with decreasing film thickness. © 1997 American Institute of Physics.
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