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Before meaningful conclusions can be drawn from clinical measures of cerebral blood perfusion, the precision of the measurement must be determined and set in the context of inter- and intrasubject sources of variability. This work establishes the reproducibility of perfusion measurements using the noninvasive MRI technique of continuous arterial spin labeling (CASL). Perfusion was measured in 34 healthy normal subjects. Intersubject variability was assessed, and age and gender contributions were estimated. Intersubject variation was found to be large, with up to 100% perfusion difference for subjects of the same age and gender. Repeated measurements in one subject showed that perfusion remains remarkably stable in the short term when compared with intersubject variation and the large capacity for perfusion change in the brain. A significant decrease in the ratio of gray-matter to white-matter perfusion was found with increasing age (0.79% per year (P < 0.0005)). This appears to be due mainly to a reduction in gray-matter perfusion, which was found to decrease by 0.45% per year (P = 0.04). Regional analysis suggested that the gray-matter age-related changes were predominantly localized in the frontal cortex. Whole-brain perfusion was 13% higher (P = 0.02) in females compared to males.  相似文献   
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A 24-year-old man presented with a 24-hour history of pain and numbness in his left arm. The patient's clinical presentation of peripheral embolism was corroborated by angiography. Echocardiographic study showed masses in both right and left atria. Pathologic specimen from the embolus confirmed the diagnosis of aspergillosis.  相似文献   
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Session XII Male contraception  相似文献   
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  目的  研究单核细胞增生李斯特菌(Listeria monocytogenes, LM)感染对树突状细胞(dendritic cell, DC)免疫功能的影响,探讨细菌型(WT)和L型(L-form)LM对DC的免疫活化能力差异。  方法  将C57BL/6小鼠随机分为对照组、WT组、L-form组,3组小鼠分别经尾静脉感染PBS液、细菌型LM和L型LM,电镜观察脾脏DC超微结构特征;流式细胞术检测小鼠脾脏DC的数量、共刺激分子表达、胞内细胞因子分泌、脾脏T细胞亚群及其活化程度。  结果  透射电镜可观察到对照组小鼠脾脏DC表面有大量丝状伪足,胞浆均匀,细胞核大而偏于一侧;吞噬细菌后,表面丝状伪足减少,胞质内空泡增多;小鼠感染后第1天脾脏中DC绝对值无明显升高或降低(P>0.05),但成熟表型特征性分子表达上调(P < 0.05),L-form感染组DC表面CD80和CD86分子均高于WT组(P < 0.05);小鼠感染LM后TNF-α+DC比例明显升高,L-form感染组分泌TNF-α的DC高于WT组(P < 0.05);感染LM后第7天,3组小鼠脾脏CD4+T细胞和CD8+T细胞在淋巴细胞中所占比例差异均无统计学意义(P>0.05),但L-form组CD69+ T细胞比例高于WT组(P < 0.05)。  结论  L型LM可介导相对高水平的TNF-α,促进DC成熟以增强其抗原递呈的能力。  相似文献   
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Background:Virtual reality (VR) is an advanced technique used in physical rehabilitation of neurological disorders, however the effects of VR on balance, gait, and motor function in people with Parkinson’s (PD) are still debated. Therefore, the systematic review aimed to determine the role of VR on motor function, balance and gait in PD patients.Methods:A comprehensive search to identify similar randomised controlled trials was conducted targeting 5 databases including Web of Science, PubMed, CINHAL, Cochrane Library, and Physiotherapy Evidence Database. A total of 25 studies were found eligible for this systematic review, and the methodological assessment of the quality rating of the studies was accomplished using the physiotherapy evidence database scale by 2 authors.Results:Out of the 25 included studies, 14 studies reported on balance as the primary outcome, 9 studies were conducted to assess motor function, and 12 assessed gait as the primary outcome. Most studies used the Unified Parkinson disease rating scale UPDRS (part-III) for evaluating motor function and the Berg Balance Scale as primary outcome measure for assessing balance. A total of 24 trials were conducted in clinical settings, and only 1 study was home-based VR trainings. Out of 9 studies on motor function, 6 reported equal improvement of motor function as compared to other groups. In addition, VR groups also revealed superior results in improving static balance among patient with PD.Conclusion:This systemic review found that the use of VR resulted in substantial improvements in balance, gait, and motor skills in patients with PD when compared to traditional physical therapy exercises or in combination with treatments other than physical therapy. Moreover, VR can be used as a supportive method for physical rehabilitation in patients of PD. However, the majority of published studies were of fair and good quality, suggesting a demand for high quality research in this area.  相似文献   
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The use of medical devices for therapeutic and diagnostic purpose is globally increasing; however, bacterial colonization on therapeutic devices can occur, causing severe infections in the human body. It has become an issue for public health. It is necessary to develop a nanomaterial based on photothermal treatment to kill toxic bacterial strains. Appropriately, high photothermal conversion and low-cost powerful photothermal agents have been investigated. Recently, gold nanocomposites have attracted great interest in biological applications. Here, we prepared rod-shaped Se-Te@Au nanocomposites of about 200 nm with uniform shape and surface-coated with gold nanoparticles for the first time showing high anti-bacterial and anti-cancer activities. Se-Te@Au showed proper structural consistency and natural resistance to bacterial and cancer cells. The strong absorption and high photothermal conversion efficacy made it a good photothermal agent material for the photothermal treatment of bacterial and cancer cells. The Se-Te@Au rod showed excellent anti-bacterial efficacy against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus, with highest recorded inhibition zones of 25 ± 2 mm and 22 ± 2 mm, respectively. More than 99% of both types of strains were killed after 5 min with a near-infrared (NIR) laser at the very low concentration of 48 µg/mL. The Se-Te@Au rod’s explosion in HeLa cells was extensively repressed and demonstrated high toxicity at 100 µg/mL for 5 min when subjected to an NIR laser. As a result of its high photothermal characteristics, the exceptional anti-bacterial and anti-cancer effects of the Se-Te@Au rod are considerably better than those of other methods previously published in articles. This study could open a new framework for sterilization applications on the industrial level.  相似文献   
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