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961.
962.
建立了食品中碱性黄、碱性嫩黄、碱性橙II、酸性橙II、罗丹明B、对位红、苏丹类1-4号11种有机染料的高效液相色谱分析方法。在0.2-10μg/mL的浓度范围内线性相关系数良好,相关系数范围为0.9996-0.9999,检测限0.05μg/mL。该方法涉及的化学试剂少,操作简便,结果准确。对阳性样品进一步采用液质联用技术确证。  相似文献   
963.
Currently, surgical resection is one of only a few options for treating hepatocellular carcinoma (HCC). Unfortunately, postoperative tumor recurrence remains almost inevitable despite additional radiation or chemotherapy treatment following radical resection. Clinical observations and a growing body of experimental evidence have led to speculation that there is a population of persistent hepatic cancer stem cells (HCSCs), which are difficult to completely remove surgically. HCSCs are most often in a quiescent state and thought to reside in a specific microenvironment known as a niche that provides the cues necessary for HCSCs to maintain a balance of self-renewal and differentiation. Residual HCSCs following surgery may alter their fate by invading into the blood circulation. Furthermore, it remains to be determined if hepatectomy render the postoperative niche more favorable for the survival and growth of HCSCs, and therefore the recurrence of HCC. A better understanding of the mechanisms for HCSCs self-renewal, invasion and recurrence may provide new insights into curative strategies for treating HCC.  相似文献   
964.
Neuronal autophagy is essential for neuronal survival and the maintenance of neuronal homeostasis. Increasing evidence has implicated autophagic dysfunction in the pathogenesis of Alzheimer’s disease (AD). The mechanisms underlying autophagic failure in AD involve several steps, from autophagosome formation to degradation. The effect of modulating autophagy is context-dependent. Stimulation of autophagy is not always beneficial. During the implementation of therapies that modulate autophagy, the nature of the autophagic defect, the timing of intervention, and the optimal level and duration of modulation should be fully considered.  相似文献   
965.
Many low-dimensional nanostructured metal oxides (MOXs) with impressive room-temperature gas-sensing characteristics have been synthesized, yet transforming them into relatively robust bulk materials has been quite neglected. Pt-decorated SnO2 nanoparticles with 0.25–2.5 wt% Pt were prepared, and highly attractive room-temperature hydrogen-sensing characteristics were observed for them all through pressing them into pellets. Some pressed pellets were further sintered over a wide temperature range of 600–1200 °C. Though the room-temperature hydrogen-sensing characteristics were greatly degraded in many samples after sintering, those samples with 0.25 wt% Pt and sintered at 800 °C exhibited impressive room-temperature hydrogen-sensing characteristics comparable to those of their counterparts of as-pressed pellets. The variation of room-temperature hydrogen-sensing characteristics among the samples was explained by the facts that the connectivity between SnO2 grains increases with increasing sintering temperature, and Pt promotes oxidation of SnO2 at high temperatures. These results clearly demonstrate that some low-dimensional MOX nanocrystals can be successfully transformed into bulk MOXs with improved robustness and comparable room-temperature gas-sensing characteristics.  相似文献   
966.
967.
968.
969.
In this paper, a 3-channel wavelet transform method is introduced to recover palm print images following serious deformation. The deformation processing is actually a kind of digital re-sampling. A filter bank consisting of three filters is implemented for wavelet decomposition of the palm print image, and then a procedure of binary interpolation is performed after the image is reconstructed by another filter bank consisting of another three filters. The design of multi-channel wavelet filter bank is based on the Quadrature Mirror Filter (QMF) method. Because the noise is caused by the Morie stripe, the images are further de-noised after the geometry deformation is addressed. Acceptable results have been obtained.  相似文献   
970.
目的探讨雾化吸入伊洛前列素溶液对初入高海拔地区青年血流动力学的影响。方法将32名受试者随机分为伊洛前列素组(n=16)和对照组(n=16),自海拔1 400 m历时5 d进入5 200 m,从进入海拔5 200 m当天开始,伊洛前列素组4次/d雾化吸入伊洛前列素溶液,连续5 d。对照组用同样的方法吸入生理盐水。于吸入伊洛前列素溶液第5天,用XG-Ⅲ型血液循环功能自动测试仪检测两组受试者的血流动力学。结果伊洛前列素组较对照组P、TPR、ALT、η、BK、PAWP、CCP降低,差异有统计学意义(P<0.05);SV、MAP、BV增高,差异有统计学意义(P<0.05)。结论在高原雾化吸入伊洛前列素溶液对初入高海拔地区青年血流动力学有明显的改善作用。  相似文献   
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