Pentacene-Gate Dielectric Interface Modification with Silicon Nanoparticles for OTFTs

AbstractWe report on the properties of pentacene layers and OTFTs (Organic Thin Film Transistors) deposited on semiconductor-gate insulator interfaces covered with silicon nanoparticles (SiNPs) monolayer prepared by the Langmuir-Blodgett method compared to a reference sample (without SiNPs) prepared in an otherwise identical way. To analyse the structural quality, micro-Raman spectroscopy was employed and the correspondence between thin and bulk phase of the integral intensities peaks ratio (α) at 1154 and 1158cm-1 (α = Int1154 /Int1158) was evaluated. The AFM analysis of the pentacene layers reveals that the different surface treatment of SiO2 gate insulator (hydrophobic or hydrophilic) before SiNPs monolayer deposition has a distinct influence on the formation of different pentacene grain size and morphology. We demonstrate the higher time stability of pentacene OTFT and increasing of saturation current (∼ 2.5 ×) behavior after storage time if the semiconductor-gate insulator interface is modified using a SiNP monolayer

Разработка технологического процесса изготовления опоры двигателя

Выпускная квалификационная работа состоит из 4 разделов. В качестве задания был получен чертёж детали для которой разработан технологический маршрут изготовления. В технологическом разделе даны расчёты и пояснения для обеспечения требований, заданных конструктором. В качестве заготовки выбран круглый прокат алюминиевого сплава Д16Т. В конструкторском разделе спроектировано приспособления для сверления отверстий. В экономическом разделе выполнения расчёт стоимости детали. В разделе социальной ответственности и безопасности жизнедеятельности приведены основные требования для безопасной работы оператора за станком.This work is devoted to creation of technological process of the part "engine bracket" and consist of 4 parts. The first part is considering sequence of machining workpiece, calculation of operational time and cutting conditions. The second part is devoted to special device, which helps drilling accurate holes. The third and the forth parts are economical (where counting of the price is making) and social responsibility (where norms of pollution for workers and environment are calculated)

Male Circumcision for Prevention of HIV Transmission: What the New Data Mean for HIV Prevention in the United States

Recent clinical trials in Africa found that male circumcision reduces the risk of acquiring HIV from heterosexual sex--what are the implications of these studies for the United States

Effects of Genital Ulcer Disease and Herpes Simplex Virus Type 2 on the Efficacy of Male Circumcision for HIV Prevention: Analyses from the Rakai Trials

Ron Gray and colleagues analyze data from two circumcision trials in Uganda to assess how HSV-2 status and genital ulcer disease affect the procedure's ability to reduce HIV infection

Setting the stage: host invasion by HIV.

For more than two decades, HIV has infected millions of people worldwide each year through mucosal transmission. Our knowledge of how HIV secures a foothold at both the molecular and cellular levels has been expanded by recent investigations that have applied new technologies and used improved techniques to isolate ex vivo human tissue and generate in vitro cellular models, as well as more relevant in vivo animal challenge systems. Here, we review the current concepts of the immediate events that follow viral exposure at genital mucosal sites where most documented transmissions occur. Furthermore, we discuss the gaps in our knowledge that are relevant to future studies, which will shape strategies for effective HIV prevention

The HIV-1 transmission bottleneck

It is well established that most new systemic infections of HIV-1 can be traced back to one or a limited number of founder viruses. Usually, these founders are more closely related to minor HIV-1 populations in the blood of the presumed donor than to more abundant lineages. This has led to the widely accepted idea that transmission selects for viral characteristics that facilitate crossing the mucosal barrier of the recipient’s genital tract, although the specific selective forces or advantages are not completely defined. However, there are other steps along the way to becoming a founder virus at which selection may occur. These steps include the transition from the donor’s general circulation to the genital tract compartment, survival within the transmission fluid, and establishment of a nascent stable local infection in the recipient’s genital tract. Finally, there is the possibility that important narrowing events may also occur during establishment of systemic infection. This is suggested by the surprising observation that the number of founder viruses detected after transmission in intravenous drug users is also limited. Although some of these steps may be heavily selective, others may result mostly in a stochastic narrowing of the available founder pool. Collectively, they shape the initial infection in each recipient