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After spontaneous regression of transplanted tumours, marked reduction in number of tumours was found when challenged with isogenic tumour cells. The ALS abrogates this effect. Tumour removal by surgical excision of limb and subsequent time scheduled challenge by tumour cells maximally suppress on the 10th day and continues up to the 42nd day the tumorogenic effect. Splenectomy has no effect if done before a day or 3 days after challenge but marked decrease in tumour development was seen when challenged on the 8th day after splenectomy. Amputation and splenectomy together potentiates tumour formation. Only in tumour extrication, does resistance develop up to the 42nd day from surgery. Challenging at a different site in mice with tumours, resulted in prolongation of the intervals of tumour formation. Challenge after surgical removal of tumour after a time lapse, results in marked reduction in number and size of tumours. Surgical tumour extrication after splenectomy and subsequent challenge on 11th day inhibited tumour formation. Whereas splenectomized tumour bearing mice when challenged at a heterosite did not develop resistance. 相似文献
3.
L.F. Lester W.J. Schaff S.D. Offsey L.F. Eastman 《Photonics Technology Letters, IEEE》1991,3(5):403-405
Graded-index separate-confinement heterostructure (GRINSCH) strained-layer lasers with five In/sub 0.3/Ga/sub 0.7/As quantum wells have been fabricated with cavity lengths from 50 to 400 mu m using chemically assisted ion-beam etching (CAIBE) to form the laser mirrors. The dry-etching process is thermally assisted, which gives a reproducible etching rate. A minimum threshold-current value is observed at a cavity length of 50 mu m, showing that the multiquantum-well design is optimum for short-cavity lasers. A relaxation oscillation frequency of 10 GHz and a -3 dB bandwidth of 15 GHz have been measured on a 200*10 mu m mesa-structure device.<> 相似文献
4.
EL Alderman JH Levy JB Rich M Nili B Vidne H Schaff G Uretzky G Pettersson JJ Thiis CB Hantler B Chaitman A Nadel 《Canadian Metallurgical Quarterly》1998,116(5):716-730
OBJECTIVE: We examined the effects of aprotinin on graft patency, prevalence of myocardial infarction, and blood loss in patients undergoing primary coronary surgery with cardiopulmonary bypass. METHODS: Patients from 13 international sites were randomized to receive intraoperative aprotinin (n = 436) or placebo (n = 434). Graft angiography was obtained a mean of 10.8 days after the operation. Electrocardiograms, cardiac enzymes, and blood loss and replacement were evaluated. RESULTS: In 796 assessable patients, aprotinin reduced thoracic drainage volume by 43% (P < .0001) and requirement for red blood cell administration by 49% (P < .0001). Among 703 patients with assessable saphenous vein grafts, occlusions occurred in 15.4% of aprotinin-treated patients and 10.9% of patients receiving placebo (P = .03). After we had adjusted for risk factors associated with vein graft occlusion, the aprotinin versus placebo risk ratio decreased from 1.7 to 1.05 (90% confidence interval, 0.6 to 1.8). These factors included female gender, lack of prior aspirin therapy, small and poor distal vessel quality, and possibly use of aprotinin-treated blood as excised vein perfusate. At United States sites, patients had characteristics more favorable for graft patency, and occlusions occurred in 9.4% of the aprotinin group and 9.5% of the placebo group (P = .72). At Danish and Israeli sites, where patients had more adverse characteristics, occlusions occurred in 23.0% of aprotinin- and 12.4% of placebo-treated patients (P = .01). Aprotinin did not affect the occurrence of myocardial infarction (aprotinin: 2.9%; placebo: 3.8%) or mortality (aprotinin: 1.4%; placebo: 1.6%). CONCLUSIONS: In this study, the probability of early vein graft occlusion was increased by aprotinin, but this outcome was promoted by multiple risk factors for graft occlusion. 相似文献
5.
Sparse nonlinear classification and regression models in reproducing kernel Hilbert spaces (RKHSs) are considered. The use of Mercer kernels and the square loss function gives rise to an overdetermined linear least-squares problem in the corresponding RKHS. When we apply a greedy forward selection scheme, the least-squares problem may be solved by an order-recursive update of the pseudoinverse in each iteration step. The computational time is linear with respect to the number of the selected training samples. 相似文献
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Jonas Winkelbauer Georg Puchas Stefan Schafföner Walter Krenkel 《International Journal of Applied Ceramic Technology》2022,19(2):1136-1147
This paper presents a novel fiber spraying process for the manufacturing of short fiber bundle-reinforced Nextel™ 610/Al2O3-ZrO2 oxide fiber composites (SF-OFC) and its characterization. First, the influence of varying fiber lengths (7, 14, and 28 mm, continuous fibers) and fiber orientations (unidirectional 0°, quasi-isotropic, ±45°) was investigated using hand-laid SF-OFC. Due to the weak matrix, the hand-laid material exhibited a strongly fiber-dominated material behavior, that is, variations in fiber length and orientation had a strong influence on the material properties. Second, the automated sprayed SF-OFC, however, exhibited a random orientation of the fiber bundles, which resulted in in-plane isotropic material properties. Average bending strengths of up to 177 MPa, strains of .39%, and a quasi-ductile fracture behavior were achieved. The strain was, therefore, in the range of fabric-reinforced OFC. While the bending strength of the SF-OFC was somewhat lower than that of fabric-reinforced OFC with the fiber orientation parallel to the loading direction, it was more than two times higher than the strength in 45° direction relative to the fabric reinforcement. Combined with good drapability and lower material costs compared to fabric-reinforced OFC, SF-OFC is, therefore, a promising material for industrial applications. 相似文献
8.
Daniel Schreckling Johannes Köstler Matthias Schaff 《Information Security Technical Report》2013,17(3):71-80
We introduce Kynoid, a real-time monitoring and enforcement framework for Android. Kynoid is based on user-defined security policies which are defined for data-items. This allows users to define temporal, spatial, and destination constraints which have to hold for single items. We introduce an innovative approach to allow for the real-time tracking and enforcement of such policies. In this way, Kynoid is the first extension for Android which enables the enforcement of security policies of data-items stored in shared resources. We outline Kynoid's architecture, present its operation and discuss it in terms of applicability, and performance. By providing a proof-of-concept implementation we further show the feasibility of our framework. 相似文献
9.
D. E. Walker Jr. M. Gao X. Chen W. J. Schaff L. J. Brillson 《Journal of Electronic Materials》2006,35(4):581-586
A new approach to studying Schottky barrier formation on a nanometer scale is demonstrated using both Auger electron spectroscopy
core level shift and secondary electron threshold work function measurements on cleaved epilayers. Band bending induced by
metallization of cleaved epilayer surfaces can be investigated without introducing defects due to chemical or ion beam surface
cleaning. For GaN epilayers, this approach also avoids complications due to piezoelectric effects on polar-axis growth surfaces.
Initial investigations of Au and Ag Schottky contact formation on GaN in ultrahigh vacuum reveal the presence of a pinning
level ∼1.7 eV above the valence band edge. 相似文献
10.
高压SF_6断路器经多次改进在欧洲和日本已发展成第三代产品,第一代为热膨胀式断路器加助吹,将液压机构改为弹簧操动机构和变开距混合式灭弧室。第二代产品为改善开断容性电流特性发展“双容积”灭弧室和新型动态压缩灭弧室,以及双向运行触头系统等,更进一步减少分合闸操作功应用旋弧灭弧原理迫使电弧快速旋转冷却使电流零点时熄灭。第三代产品主要介绍加强操动机构的可靠性和稳定性,传输时无功消耗少,减少机构零件数量等。 相似文献