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Journal of Porous Materials - Catalysts of AlMCM-48 with different Si/Al molar rations were synthesized by modified hydrothermal method with respect to previous works. As a consequence, the...  相似文献   
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To ascertain the possible implications of the nitric oxide (NO*) producing system in striatal senescence, and by using immunohistochemistry and image-processing approaches, we describe the presence of the enzyme nitric oxide synthase (NOS), the NADPH-diaphorase (NADPH-d) histochemical marker, and nitrotyrosine-derived complexes (N-Tyr) in the striatum of adult and aged rats. The results showed neuronal NOS immunoreactive (nNOS-IR) aspiny medium-sized neurons and nervous fibres in both age groups, with no variation in the percentage of immunoreactive area but a significant decrease in the intensity and in the number of somata with age, which were not related to the observed increase with age of the striatal bundles of the white matter. In addition, NADPH-d activity was detected in neurons with morphology similar to that of the nNOS-IR cells; a decrease in the percentage of area per field and in the number of cells, but an increase in the intensity of staining for the NADPH-d histochemical marker, were detected with age. The number of neuronal NADPH-d somata was higher than for the nNOS-IR ones in both age groups. Moreover, N-Tyr-IR complexes were observed in cells (neurons and glia) and fibres, with a significant increase in the percentage of the area of immunoreaction, related to the increase of white matter, but a decrease in intensity for the aged group. On the other hand, we did not detect the inducible isoform (iNOS) either in adult or in aged rats. Taken together, these results support the contention that NADPH-d staining is not such an unambiguous marker for nNOS, and that increased protein nitration may participate in striatal aging.  相似文献   
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基于空间跟踪与监视系统性能参数信息,借鉴国内相关研究成果,建立了空间跟踪与监视系统红外探测能力分析相关模型,分析了其探测距离、探测精度、定位精度、识别能力,对于空间跟踪与监视系统的相关研究工作具有一定的参考价值.  相似文献   
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修正的极大似然估计法是一种基于经典估计理论系统的可靠性分析方法中较优的算法。主要介绍MML方法及其在航空航天系统可靠性分析中的应用。  相似文献   
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The percutaneous cardiopulmonary support system (PCPS) was used in a 64-year-old woman with cardiogenic shock due to sustained ventricular fibrillation (Vf) caused by severe aortic stenosis and regurgitation. The Vf attack was resistant to cardioversion and adrenaline for lack of left ventricular support by PCPS. She was transported to the operation theater with PCPS in situ and emergency aortic valve replacement was performed. Although preoperative cardiac resuscitation time was long (35 minutes), she was discharged from the hospital on foot without any neurological complications on 84th postoperative day. Because PCPS does not decrease left ventricular systolic stress in poorly contracting dilated heart, early surgical treatment is needed in patients with severely damaged heart.  相似文献   
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