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排序方式: 共有423条查询结果,搜索用时 15 毫秒
81.
Herman Kasper Gilissen Maarten Kleinhans Marleen van Rijswick Karianne van der Werf 《国际水》2019,44(6-7):701-718
ABSTRACTThis article finds that the introduction of a rights-based approach in EU transboundary river basin management to remedy observed systemic difficulties and to better achieve legal water quality standards could be a next step in achieving integrated river basin management. However, its effectiveness largely depends on the willingness of member states to share river basin districts to subordinate their separate socio-economic interests to ecological needs, as well as to grant a clear mandate and partly transfer responsibilities and powers to a competent supranational authority. 相似文献
82.
83.
BACKGROUND: Head and neck osteosarcoma is a comparatively rare and aggressive malignancy. Our goal was to examine the experience of head and neck osteosarcoma patients seen over a 15-year period at the University of Washington Medical Center and compare this with the published experience of other centers in terms of demographics, histology, treatment, and survival rate. METHODS: We reviewed surgical pathology slides and clinical treatment records of 13 patients who were treated at the University of Washington Medical Center between 1981 and 1996. A total of 17 cases from 13 patients (13 primary tumors and 4 recurrences) were studied. RESULTS: There was a slight male predominance, with a male:female ratio of 1.6:1, and median age at diagnosis of 40.9 years (range 22 to 75 years), both slightly higher than has been generally reported. Three of 13 patients had recognized risk factors for the development of osteosarcoma: 2 with a history of prior radiotherapy and 1 with Paget's disease. All surgical pathology specimens were examined independently by two pathologists for histologic grading and typing. At initial presentation, 9/13 (69%) cases had conventional (osteoblastic) histology; 2/13 (15%) were fibroblastic, 1 chondroblastic (8%) and 1 parosteal (8%). Eight of 13 (62%) cases were high grade at initial presentation. Four of 13 (30%) of the primary tumors were low grade 2, of which did not recur over a median follow-up period of 24 months. The other 2 low-grade tumors later recurred locally, as high-grade osteosarcomas, after disease-free intervals of 1 year and 14 years, respectively. One patient had an intermediate-grade tumor which has not recurred as of last follow-up. Combined-modality treatment, including surgery with or without radiotherapy and/or chemotherapy, was given depending on the histologic grade, surgical margins, and recurrence. Some patients with low-grade tumors had surgery only. There were 5 local recurrences, 1 of these following a disease-free interval of 14 years. One patient had 3 separate recurrences at the same site. Ten of 13 (77%) are alive and disease-free. Of the 3 deaths, 1 was related to radiation-induced brain necrosis, without evidence of recurrent tumor. The project 5-year overall survival in this series is 72%, with a mean follow-up of 58 months (median, 36 months). Of those receiving neoadjuvant chemotherapy, 6/7 have survived to the present. CONCLUSION: Given the limitations of a small patient population, our data suggest that neoadjuvant chemotherapy may provide benefit in terms of survival. Longer follow-up will be necessary to support this conclusion. Our data also show that our population has a higher-than-average age of onset, low presence of risk factors, and better survival rate in comparison with the published series from other institutions. 相似文献
84.
Eisenstein G. Tucker R.S. Korotky S.K. Raybon G. Veselka J.J. Buhl L.L. Gnauck A.H. Kasper B.L. Alferness R.C. 《Electronics letters》1987,23(21):1115-1116
We describe the design and performance of an experimental two-channel optical time-division multiplexed fibre transmission system operating at a wavelength of 1.3 ?m and a bit rate of 8 Gbit/s. Transmission over 8 km of single-mode fibre with low crosstalk and transmission error rates as low as 10?10 is demonstrated. 相似文献
85.
R Koslowski LG Dobbs KW Wenzel D Schuh M Müller M Kasper 《Canadian Metallurgical Quarterly》1998,12(6):1397-1403
After lung injury, the epithelial cells lining the alveolar surface in rat lung show an altered distribution of several membrane proteins. Pulmonary fibrosis was induced by intratracheal administration of bleomycin into the lung of rats and the distribution of RTI40, a recently detected alveolar epithelial type I cell antigen, was examined, as well as the relationship between RTI40 and a type I cell-specific antigen recognized by the monoclonal antibody MEP-1 and the type I cell-binding lectin Bauhinia purpurea in serial sections and double stainings. Loss of RTI40 protein was observed in fibrotic lungs, particularly in areas with obliteration of alveoli. Pre-embedding immunoelectron microscopy confirmed this observation by detection of RTI40 protein in the alveolar lumen. Western blot analysis revealed elevated levels of RTI40 in the bronchoalveolar fluid of bleomycin-treated rats with a maximum at day 7 after treatment. Twenty-eight days after bleomycin application, the bronchoalveolar fluid contained three times the amount of RTI40 x mg protein(-1) of control lungs, as determined by semiquantitative dot blot. These results suggest RTI40 as a tool for the evaluation of alveolar epithelial type I cell behaviour during re-epithelialization processes. 相似文献
86.
A cross-sectional study was conducted to estimate the prevalence of major risk factors for cardiovascular diseases (CVD) among the adult population in Bahrain, an Arab Gulf country. A total sample of 516 subjects aged 30-79 years was selected proportionally from all geographical areas of Bahrain. Findings revealed that current smokers represented 32% of men and 20% of women (P < 0.001). However, a relatively high percentage of women were exposed to inhalation of other family member tobacco smoking compared to men (29% and 44% among men and women, respectively). Obesity, hypertension and diabetes were highly prevalent and significantly more reported among women than men. Of women, 79.6% were overweight or obese compared to 56% of men. Sedentary lifestyle patterns (Lack of physical exercise and daily watching of television) were also highly reported. About 12.1% of men and 15.7% of women did not consume fresh fruits. The corresponding percentages for fresh vegetables were 8.4% and 5.5%, respectively. The prevalence of well established risk factors for CVD such as smoking, obesity, inactivity, diabetes and hypertension were high and indicates the need for a national health policy to prevent and control the CVD. 相似文献
87.
88.
The relationship between changes in blood coagulation, the occurrence and severity of risk factors of ischemic heart disease and the clinical condition of the patient was investigated. The at risk group of patients 42.2% had more than 3 pathological parameters. Intravascular blood coagulation was not activated in any of the patients. In patients with acute myocardial infarction (MI), 62.2% had more than 3 pathological parameters on the first day of MI development. Demonstrable activation of intravascular blood coagulation was found in 28.2% of these patients. On day 5 of MI, activation of intravascular blood coagulation was recorded in 57.7% of the patients treated by classical approach and in 15.4-30.8% of the patients on thrombolytic treatment. In the at risk group, primary hemostasis and the fibrinolytic system were more affected, in patients with MI the whole hemostatic mechanism was involved. On day 5 of MI, in patients with classical therapy pathological laboratory findings still persisted or were even more deteriorated, particularly increases in fibrinogen level. At that time, in patients on thrombolytic therapy no substantial changes of initial values were recorded. No correlation was found to exist between changes in hemostasis and the risk profile or between changes in hemostasis and the clinical severity of MI. The obtained results justify the administration of antithrombotic substances, especially in patients with unstable angina pectoris. On observing time constraints, administration of thrombolytics is justified in MI. (Fig. 9, Ref. 25.) 相似文献
89.
A Si/Si/sub 0.8/Ge/sub 0.2/ heterojunction bipolar transistor was fabricated having emitter, base and collector contacts at the wafer surface. The base doping concentration amounted to 10/sup 19//cm/sup 3/ which was 20 times the emitter concentration. Due to the pronounced difference in bandgap energy a current gain of 17 was reached.<> 相似文献
90.
AB Shanafelt CP Forte JJ Kasper L Sanchez-Pescador M Wetzel R Gundel JM Greve 《Canadian Metallurgical Quarterly》1998,95(16):9454-9458
Interleukin 4 (IL-4) is a pleiotropic cytokine. Of the cell types responsive to IL-4, T cells express one IL-4 receptor (IL-4R) type, IL-4Ralpha/IL-2Rgamma (class I IL-4R), whereas endothelial cells express another type, IL-4Ralpha/IL-13Ralpha (class II IL-4R). It was hypothesized that IL-4 variants could be generated that would be selective for cell types expressing the different IL-4Rs. A series of IL-4 muteins were generated that were substituted in the region of IL-4 implicated in interactions with IL-2Rgamma. These muteins were evaluated in T cell and endothelial cell assays. One of these muteins, containing the mutation Arg-121 to Glu (IL-4/R121E), exhibited complete biological selectivity for T cells, B cells, and monocytes, but showed no activity on endothelial cells. Receptor binding studies indicated that IL-4/R121E retained physical interaction with IL-2Rgamma but not IL-13Ralpha; consistent with this observation, IL-4/R121E was an antagonist of IL-4-induced activity on endothelial cells. IL-4/R121E exhibits a spectrum of activities in vitro that suggest utility in the treatment of certain autoimmune diseases. 相似文献