紫外线杀菌的原理和最新应用

1紫外线杀菌的原理介绍 1.1紫外线杀菌原理 紫外线用于消毒、杀菌已经很多年了,细菌的细胞中含有细菌的遗传信息核酸DNA和RNA,当核酸被紫外线照射时会大量地吸收紫外光,从而就会在体内形成一部分的间二氮杂苯(主要构成为蛋白酶)和间二氮杂苯的异构体.这种物质会使细菌自身的新陈代谢机能出现障碍,并且会导致细菌的遗传性出现问题,而持续的紫外线照射,最后就会导致因为上述原因所造成的细菌群体的死亡.此外,紫外光除了杀菌的用途外,也可用于让微生物降低自身的"活动性",有些细菌在可见光的照射下是比较活跃的,我们称之为"光恢复"特性,也就是说,在波长为300～500nm的可见光下,细菌自身有一种光恢复酶素会让细菌种群变得很活跃,自身会大量繁殖.所以,当需要控制这种细菌的数量及种群时,则可以考虑用微弱的紫外线进行照射,将细菌的数量控制在一定范围之内.     

粘弹性流体旋转流实验研究

利用粒子图像测速仪(PIV)对圆筒形容器内有自由表面变形的粘弹性流体旋转流动进行了实验研究.旋转流动由等速旋转的容器底面来驱动.实验工质为CTAC(十六烷基三甲基氯化铵界面活性剂)水溶液.测量了水、40×10-6、60×10-6和200×10-6CTAC水溶液在弗鲁德数为2.59至16.3范围内的旋转流动.PIV用来测量子午面内的二次流场,并从PIV图像中抽取自由面高度.结果表明在相似的弗鲁德数下,相比于水流CTAC水溶液旋转流动自由表面中心处的凹陷深度降低,随着溶液浓度或粘弹性升高,子午面内右上角的惯性涡被压缩且强度变得越来越弱.通过与水流动比较并做力平衡分析,定量估算了CTAC水溶液的第一正应力差或弱粘弹性.     

Self-dissolving micropile array tips for percutaneous administration of insulin

Two kinds of insulin were loaded into self-dissolving micropile array tip (following tip). Fully-loaded tip (f-tip) and partially-loaded tip (p-tip) were prepared using chondroitin sulfate for the percutaneous administration of insulin. One hundred micropiles were constructed on a 1.0 × 1.0 cm tip. The mean length of the micropile in a tip were 483.4 ± 4.7 μm for the f-tip and 492.6 ± 2.4 μm for the p-tip. The insulin content of the p-tip was 28.5% of that of the f-tip. The pharmacological efficiency of insulin loaded tip was evaluated in rat experiments by measuring their hypoglycemic effects. The maximum hypoglycemic effect of insulin was observed at 1.7 ± 0.2 h for the f-tip and 1.5 ± 0.2 h for the p-tip. Good dose-dependency was observed for the plasma glucose level vs. time curves. These results suggest the usefulness of p-tip as a percutaneous DDS of insulin.     

High‐brightness electron sources for a next‐generation light source based on an energy recovery linac

A high‐brightness electron source of ultrasmall emittance and high average current is one of the most important components for next‐generation light sources based on an energy‐recovery linac (ERL). Such a high‐brightness electron source can be realized by a DC photocathode gun driven by laser pulses tailored in the temporal and spatial dimensions. We propose a novel photocathode based on a quantum cascade laser (QCL). Since the ultrafast response of photoelectron emission from QCL is compatible with the tailored laser pulses, it is a candidate electron source for ERLs. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 177(3): 46–53, 2011; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21154     

Impact of the Coulomb interaction on nano-scale silicon device characteristics

Monte Carlo simulations coupled self-consistently with the three-dimensional Poisson equation are carried out under the double-gate MOSFET structures. The Coulomb force experienced by an electron inside the device is directly evaluated by performing the Monte Carlo simulations with or without the full Coulomb interaction and the Coulomb force on the channel electron corresponding to plasmon excitations is clarified. It is pointed out that the consistency of the boundary condition is achieved only if the long-range Coulomb interaction is properly taken into account, and this is crucial for predicting reliable device characteristics in ultra-small devices. The drain current and transconductance are greatly reduced if the self-consistent potential fluctuations are taken into account.     

Asymmetry in object substitution masking occurs relative to the direction of spatial attention shift.

A sparse mask that persists beyond the duration of a target can reduce its visibility, a phenomenon called object substitution masking. Y. Jiang and M. M. Chun (2001a) found an asymmetric pattern of substitution masking such that a mask on the peripheral side of the target caused stronger substitution masking than on the central side. Assuming spatial attention was focused toward the target, the peripheral and central masks were located in the same and opposite direction of an attentional path with reference to the target in their study. We hypothesized that this asymmetric mask configuration relative to the attentional shift contributes to asymmetric substitution masking. To test this hypothesis, we conducted four experiments among which the presence or absence of the center–periphery relationship and the presence or absence of the asymmetric mask configuration were manipulated independently and orthogonally. The results suggest that asymmetric substitution masking occurs relative to the direction of spatial attention irrespective of the central–peripheral relation. We propose that the asymmetry in substitution masking might be explained by attentional momentum associated with orienting toward the target. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Correlations of Hepatic Hemodynamics,Liver Function,and Fibrosis Markers in Nonalcoholic Fatty Liver Disease: Comparison with Chronic Hepatitis Related to Hepatitis C Virus

The progression of chronic liver disease differs by etiology. The aim of this study was to elucidate the difference in disease progression between chronic hepatitis C (CHC) and nonalcoholic fatty liver disease (NAFLD) by means of fibrosis markers, liver function, and hepatic tissue blood flow (TBF). Xenon computed tomography (Xe-CT) was performed in 139 patients with NAFLD and 152 patients with CHC (including liver cirrhosis (LC)). The cutoff values for fibrosis markers were compared between NAFLD and CHC, and correlations between hepatic TBF and liver function tests were examined at each fibrosis stage. The cutoff values for detection of the advanced fibrosis stage were lower in NAFLD than in CHC. Although portal venous TBF (PVTBF) correlated with liver function tests, PVTBF in initial LC caused by nonalcoholic steatohepatitis (NASH-LC) was significantly lower than that in hepatitis C virus (C-LC) (p = 0.014). Conversely, the liver function tests in NASH-LC were higher than those in C-LC (p < 0.05). It is important to recognize the difference between NAFLD and CHC. We concluded that changes in hepatic blood flow occurred during the earliest stage of hepatic fibrosis in patients with NAFLD; therefore, patients with NAFLD need to be followed carefully.