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91.
BACKGROUND: Calcium channel blockers (CCBs) are known to have differential effects on both changes in proteinuria as well as progression of diabetic nephropathy. No clinical study, however, has evaluated whether the differential antiproteinuric effects of CCBs may be explained by their effect on glomerular membrane permeability. We, therefore, tested the hypothesis that certain subclasses of CCBs reduce proteinuria by changing size selectivity of the glomerular membrane, hence changing its permeability. METHODS: Twenty-one patients with type 2 diabetes and the presence of nephropathy with hypertension were randomized to receive either diltiazem CD or nifedipine GITS after baseline data for mean systolic and diastolic pressure, urinary protein excretion, glomerular filtration rate, renal plasma flow, neutral dextran and IgG clearances were obtained. Glomerular filtration rate, renal plasma flow, neutral dextran and IgG clearance were measured every three months, arterial pressure and heart rate every month. Patients were followed for 21 months. RESULTS: At 21 months, both patient groups had similar levels of blood pressure control, however, only the diltiazem group had a change in proteinuria (4+/-10%delta, nifedipine vs. -57+/-18%delta, diltiazem; P < 0.001) with improvement in glomerular size selectivity and change in IgG clearance. CONCLUSIONS: These data support the hypothesis that CCBs that provide sustained reductions in proteinuria do so, in part, by improving glomerular size permselectivity.  相似文献   
92.
Cancer continues to be a leading source of morbidity and mortality worldwide in spite of progress in oncolytic therapies. In addition, the incidence of cancers affecting the breast, kidney, prostate and skin among others continue to rise. Chemotherapeutic drugs are widely used in cancer treatment but have the serious drawback of nonspecific toxicity because these agents target any rapidly dividing cell without discriminating between healthy and malignant cells. In addition, many neoplasms eventually become resistant to conventional chemotherapy due to selection for multidrug-resistant variants. The limitations associated with existing chemotherapeutic drugs have stimulated the search for new oncolytic therapies. Host defense peptides (HDPs) may represent a novel family of oncolytic agents that can avoid the shortcomings of conventional chemotherapy because they exhibit selective cytotoxicity against a broad spectrum of malignant human cells, including multi-drug-resistant neoplastic cells. Oncolytic activity by HDPs is usually via necrosis due to cell membrane lysis, but some HDPs can trigger apoptosis in cancer cells via mitochondrial membrane disruption. In addition, certain HDPs are anti-angiogenic which may inhibit cancer progression. This paper reviews oncolytic HDP studies in order to address the suitability of selected HDPs as oncolytic therapies.  相似文献   
93.
本文对老旧电梯及老旧电梯改造存在的问题进行探讨,简要介绍重庆市推进老旧电梯改造工作制定的制度保障,提出采用BOT模式、强制第三方责任保险等方式建立老旧电梯改造的长效机制,以解决日益困扰城市发展的老旧电梯问题。  相似文献   
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Nerve growth factor (NGF) plays a vital role in reducing the loss of cholinergic neurons in Alzheimer's disease (AD). However, its delivery to the brain remains a challenge. Herein, NGF is loaded into degradable oxidized porous silicon (PSiO2) carriers, which are designed to carry and continuously release the protein over a 1 month period. The released NGF exhibits a substantial neuroprotective effect in differentiated rat pheochromocytoma PC12 cells against amyloid‐beta (Aβ)‐induced cytotoxicity, which is associated with Alzheimer's disease. Next, two potential localized administration routes of the porous carriers into murine brain are investigated: implantation of PSiO2 chips above the dura mater, and biolistic bombardment of PSiO2 microparticles through an opening in the skull using a pneumatic gene gun. The PSiO2‐implanted mice are monitored for a period of 8 weeks and no inflammation or adverse effects are observed. Subsequently, a successful biolistic delivery of these highly porous microparticles into a live‐mouse brain is demonstrated for the first time. The bombarded microparticles are observed to penetrate the brain and reach a depth of 150 µm. These results pave the way for using degradable PSiO2 carriers as potential localized delivery systems for NGF to the brain.  相似文献   
97.
游亚君  韩帅 《山西建筑》2009,35(32):193-194
主要阐述了电网中谐波的产生及影响,提出了谐波的治理措施,包括减少接入电网的谐波源,设置交流滤波器,设置有源滤波器,改变供电系统的运行方式等,以抑制谐波对电网的干扰,减少不必要的电能浪费。  相似文献   
98.
The thermal contact resistance of two solids touching each another was analyzed with particular reference to the shape of a single heat channel. This channel was assumed to have a cylindrical contour whose radius near the interface decreases gradually to the contact area forming a truncated cone.The contact resistance of the interface was found as a function of the cone angle, the ratio of the radii of the truncated cone and the properties of the materials involved.From a numerical solution it was found that the contact resistance can be described by the properties of the materials, the number of contact areas and a single function of the radii ratio and that, for small values of cot γ, the contact resistance is almost insensitive to the cone angle.  相似文献   
99.
Emanueli S  Arie A 《Applied optics》2003,42(33):6661-6665
We have measured the thermal expansion and the temperature dependence of z and y components of the refractive index for KTiOPO4 and KTiOAsO4, in the wavelength range 532-1585 nm and temperature range 25-200 degrees C, using an interferometric technique. The measurements were used to derive temperature-dependent Sellmeier equations for the two materials. These equations predict with good agreement the temperature dependence of quasi-phase-matched nonlinear frequency converters.  相似文献   
100.
We describe a novel framework for the design and analysis of online learning algorithms based on the notion of duality in constrained optimization. We cast a sub-family of universal online bounds as an optimization problem. Using the weak duality theorem we reduce the process of online learning to the task of incrementally increasing the dual objective function. The amount by which the dual increases serves as a new and natural notion of progress for analyzing online learning algorithms. We are thus able to tie the primal objective value and the number of prediction mistakes using the increase in the dual. Editors: Hans Ulrich Simon, Gabor Lugosi, Avrim Blum. A preliminary version of this paper appeared at the 19th Annual Conference on Learning Theory under the title “Online learning meets optimization in the dual”.  相似文献   
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