A study on interface and charge trapping properties of nitrided n-channel metal-oxide-semiconductor field-effect transistors by backsurface argon bombardment

A low-energy (550 eV) argon-ion beam was used to directly bombard the backsurface of nitrided n-channel metal-oxide-semiconductor field-effect transistors (n-MOSFETs) after the completion of all conventional processing steps. The interface and oxide-charge trapping characteristics of the bombarded MOSFETs were investigated as compared to nonbombarded and reoxidized-nitrided n-MOSFETs. It was found that after bombardment, interface state density decreases and interface hardness against hot-carrier bombardment enhances, and oxide charge trapping properties were also improved. The improvements exhibit a turnaround behavior depending on bombardment conditions and could be attributed to stress compensation in the vicinity of the Si/SiO2 interface and an annealing effect. © 1997 American Institute of Physics.published_or_final_versio

Quality improvement of low-pressure chemical-vapor-deposited oxide by N2O nitridation

Quality of low-pressure chemical-vapor-deposited (LPCVD) oxide and N2O-nitrided LPCVD (LN2ON) oxide is investigated under high-field stress conditions as compared to thermal oxide. It is found that LPCVD oxide has lower midgap interface-state density Dit-m and smaller stress-induced Dit-m increase than thermal oxide, but exhibits enhanced electron trapping rate and degraded charge-to-breakdown characteristics, which, however, are significantly suppressed in LN2ON oxide, suggesting effective elimination of hydrogen-related species. Moreover, LN2ON oxide shows further improved Si/SiO2 interface due to interfacial nitrogen incorporation. © 1997 American Institute of Physics.published_or_final_versio

Thrombotic microangiopathies and acute kidney injury induced by artificial termination of pregnancy

Thrombotic microangiopathy (TMA) is a rare, but potentially lethal condition requiring rapid recognition, diagnosis and initiation of therapy. Here, we present two cases of women with hemolytic anemia, thrombocytopenia and acute kidney injury shortly after surgical termination of pregnancy. Histological examination of their kidneys revealed endothelial cell swelling and luminal stenosis or fibrin.containing thrombi in the glomeruli and arterioles, which support the diagnosis of TMA. The patients were treated with hemodialysis, plasma infusion and corticosteroids with or without  immunosuppressive agents. Three weeks after treatment, one patient was cured and symptoms of the other patient markedly improved. Reporting of more cases of TMA associated with surgical termination of pregnancy will provide further insights into this rare disease, possibly aiding in identifying risk factors and improving time to clinical diagnosis, treatment and  prognosis.Key words: Acute renal failure, case studies, induced abortion, pregnancy, thrombotic microangiopath

Correlation between hot-carrier-induced interface states and GIDL current increase in N-MOSFET's

Correlation between created interface states and GIDL current increase in n-MOSFET's during hot-carrier stress is quantitatively discussed. A trap-assisted two-step tunneling model is used to relate the increased interface-state density (ADH) with the shift in GIDL current (ΔI d). Results show that under appropriate drain-gate biases, the two-step tunneling is so dominant that A/d is insensitive to temperatures up to about 50 °C. With the help of 2-D device simulation, the locations of the drain region with significant two-step tunneling and the energy levels of the traps involved can be found, with both depending on the drain voltage. From these insights on ADit,A/d and their relation, A Du near the midgap can be estimated, with an error less than 10% as compared to the results of chargepumping measurement on the same transistors. Devices with nitrided gate oxide, different gate-oxide thicknesses and different channel dimensions are also tested to verify the above correlation. © 1998 IEEE.published_or_final_versio

Adipose tissue-derived stem cells in oral mucosa tissue engineering: Enhanced migration and proliferation in co-culture with oral keratinocytes in vitro

Tissue-engineered oral mucosa holds a great prospect in urethroplasty and adipose tissue-derived stem cells (ADSCs) may play an important role in this field. In this research, canine oral keratinocytes (OKs) and ADSCs were harvested and cultured in vitro. The affinity between the two cell lines was evaluated by analyzing their migration and proliferation patterns in a co-culture environment. The results demonstrate that both canine ADSCs and OKs showed improved migration in the presence of the other cell line as a co-culture when compared to monoculture. Further, conditioned medium using the supernatant of one cell line accelerated the other cell line’s proliferation rate. Hence, it was concluded that the affinity between OKs and ADSCs was fitting; the presence of ADSCs accelerated the migration and proliferation of OKs in vitro. These results indicate that it is practical to use ADSCs and OKs to construct a tissue-engineered oral mucosa, since the presence of the former could activate the latter in vitro, maybe even in vivo. This may help to build tissue-engineered oral mucosa, which may be a new method for urethroplasty.Key words: Urethroplasty, adipose tissue-derived stem cells, oral keratinocytes, tissue engineering

Effects of a Chinese Medicinal Plant Radix Astragali on the Ovariectomized Female Rats

Perimenopausal syndrome occurs during the transition to menopause. Complementary and alternative medicine, especially Chinese medicinal plants, has manifested significant effects in alleviating perimenopausal symptoms. However, little research has been focused on the effects of Chinese medicinal plant on the immune function of the perimenopausal women. The present study aimed to explore the effects of Radix Astragali (RA) on the sex hormone levels and the interleukins of the ovariectomized female rats. 24 female Sprague-Dawley (SD) rats were randomly divided into model control group (MOD group), sham-operation group (SHAM group), RA group and estrogen group (EST group). After all the treatment ended, the serum levels of estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), interleukin-2 (IL-2), and interleukin-8 (IL-8) were measured using enzyme-linked immune-sorbent assay (ELISA) and the uterus was removed and weighed after blood exsanguinations immediately. In the MOD group, the serum levels of E2 were significantly lower, and the serum levels of FSH and LH were markedly higher than those of the RA group, EST group and SHAM group (P<0.05). In the RA group, the serum levels of E2 were significantly lower, and the serum levels of FSH were markedly higher than those of the SHAM group and EST group, respectively. In the MOD group, the serum levels of IL-2 and IL-8 were significantly lower than those of the RA group, EST group and SHAM group (P<0.05), and no marked differences existed among RA group, EST group and SHAM group in the serum levels of IL-2 and IL-8 (P>0.05). The uterine weight of the rats in the RA group, EST group and SHAM group were significantly higher than those of the rats in MOD group (P<0.05). There were no marked differences among the rats from RA group, EST group and SHAM group on the uterine weight (P>0.05). It is concluded that RA can significantly improve the immune functions of the ovariectomized female rats, although it cannot change the sex hormones levels as significantly as estrogen

Experimental study on Shear capacity of cementitious composite RPC Beams using high strength steel

Reactive Powder Concrete (RPC) is a special concrete where the microstructure is optimized by precise gradation of all particles in the mix to yield maximum density. Therefore, Reactive Powder Concrete exhibits ultra-high strength and durability. The high strength reinforcement (HSR) has high strength and good plastic deformation properties. The combination of RPC and high strength reinforcement can fully exploit their respective advantages. At present, there is little research on shear capacity of HSR reinforced RPC concrete beams, neither are design guidelines for this type of structure. Therefore, it is imperative to make detailed investigations on the shear capacity of this type of concrete. In this paper, thirty-two full scale shear tests of high strength steel reinforced RPC beams were carried out. The parameters affecting the shear capacity of this type of structures were studied, the major failure modes of this type structure due to shear are identified

Identification of chromosomes responsible for crown rot resistance in durum wheat

Dissertação de mestrado em Saúde Ocupacional, apresentada á Faculdade de Medicina da Universidade de CoimbraA Segurança, Higiene e Saúde no Trabalho (SHST) tem como objetivo conservar o bem-estar físico, mental e social dos trabalhadores, para isso, é necessário adotar medidas que exigem a interação de várias áreas como a medicina do trabalho, a higiene do trabalho, a engenharia de segurança, a ergonomia, a psicologia, entre outras. Este assunto começou a ser tido em conta, em meados do Séc. XX. Até aí o único aspeto importante relacionado com o trabalho era a produtividade, não havendo preocupação com lesões, doenças nem mesmo se essas situações conduzissem à morte do trabalhador. Tem-se verificado que os riscos psicossociais são riscos emergentes de saúde ocupacional, ou seja, são riscos novos, que estão a aumentar e cujos efeitos sobre a saúde dos trabalhadores estão a agravar-se. As novas formas de contratos de trabalho e insegurança no emprego, a mão-de-obra em envelhecimento, a intensificação do trabalho, as exigências emocionais elevadas no trabalho e a difícil conciliação entre a vida profissional e pessoal são os principais geradores de consequências negativas para os trabalhadores, para as organizações e para a sociedade. Estes riscos requerem grande preocupação por parte das empresas, no entanto devido à delicadeza necessária para abordar esta temática, à escassez dos recursos e à falta de sensibilização, muitas vezes não lhe é dada a devida importância. Os objetivos deste estudo são analisar o nível de exposição da população ativa aos riscos psicossociais, avaliar a capacidade para o trabalho e analisar os efeitos dos riscos psicossociais no trabalho na capacidade para o trabalho. Para atingir os objetivos anteriormente referidos, a metodologia utilizada foram dois questionários, autoadministrados, numa amostra de 140 trabalhadores residentes na localidade de Outil. Com os dados obtidos, foi possível inferir que a população se encontra numa situação de risco intermédio relativamente à exposição aos riscos psicossociais. Este facto não se deve ao sexo do trabalhador nem ao setor em que exerce a sua atividade profissional. Concluiu-se também que a população em estudo apresenta, de um modo geral um bom Índice de Capacidade para o Trabalho (ICT). Este índice vai diminuindo com o avançar Riscos Psicossociais e Capacidade no Trabalho na população de Outil (Cantanhede) XV da idade do trabalhador. O ICT não está correlacionado linearmente com o sexo nem com o setor profissional. Com este estudo verifica-se também que o nível de exposição aos riscos psicossociais se relaciona com a capacidade para o trabalho na medida em que alguns aspetos psicossociais do trabalho potenciam ou inibem a capacidade para o trabalho. Os aspetos que inibem a capacidade para o trabalho são: as exigências quantitativas, os conflitos laborais, a confiança horizontal e vertical, o compromisso face ao local de trabalho, a saúde em geral e os problemas em dormir. Já pelo contrário, o significado do trabalho, a importância que o trabalhador atribui ao trabalho é um fator que potencia a capacidade para o trabalho. A crise económico-financeira atravessada pelo país, e um pouco por toda a Europa, neste momento origina muitas alterações organizacionais e estruturais nas empresas, o que potencia o aparecimento dos riscos psicossociais afetando a saúde física e mental do trabalhador e consequentemente a sua capacidade para o trabalho. O reconhecimento e a gestão dos riscos psicossociais a que estão sujeitos os trabalhadores e a avaliação da sua capacidade para o trabalho tornam mais fácil e eficaz a tomada de decisão e o desenrolar de programas de ação que ajudem as empresas a ultrapassar este momento conturbado a nível socioeconómico e financeiro, mantendo os trabalhadores saudáveis física e mentalmente.The Safety and Health at Work aims to conserve the physical well-being, mental and social workers, for that is necessary to adopt measures that require the interaction of several areas such as occupational medicine, hygiene at work safety engineering, ergonomics, psychology, among others. This issue began to be taken into account in the mid-century. XX, until then the only important aspect related to the work was productivity, with no concern for injury, illness or even if these situations would lead to the death of the workers. It has been found that psychosocial risks are emerging risks to occupational health, it means that they are new risks that are increasing and whose effects on the health of workers are getting worse. The new forms of contracts of work and job insecurity, the hand labor aging, work intensification, high emotional demands at work and the difficult balance between work and personal life are the main triggers of negative consequences for workers, to organizations and to society. These risks require major concern of companies, however because of the sensitivity needed to approach this issue, resources are scarce and the lack of awareness often not been given due importance. The objectives of this study are analyze the level of exposure of the workforce to psychosocial risks, assessing the ability to work and analyze the effects of psychosocial risks at work in the capacity for work. To achieve the above objectives, the methodology used were two questionnaires, self-administered on a sample of 140 workers living in Outil. With the data obtained, it was possible to infer that the population is at an intermediate risk for exposure to psychosocial risks. This is not due to the sex of the worker or the sector where he is pursuing his professional activity. It was also concluded that the study population has, in general a good Work Ability Index (WAI). This ratio decreases with advancing age of the worker. The WAI is not correlated linearly with sex or with the professional sector. The level of exposure to psychosocial risk relates to the ability to work in so far some psychosocial aspects of the work potentiate or inhibit the ability to work. The aspects that inhibit the ability to work are: quantitative requirements, labor disputes, the horizontal and vertical trust, commitment towards the workplace, health in general and trouble sleeping. Already the contrary, the meaning of work, the importance that the worker attaches to the work is a factor that enhances the ability to work. The economic and financial crisis experienced by the country, and almost everywhere in Europe at this time gives many organizational and structural changes in companies, which enhances the appearance of psychosocial risks affecting the physical and mental health of the worker and consequently their ability to the work. Riscos Psicossociais e Capacidade no Trabalho na população de Outil (Cantanhede) XVII The recognition and management of psychosocial risks to which they are subject workers and the evaluation of their ability to make work easier and more effective decision-making and the development of programs which help companies overcome this troubled time the level socio-economic and financial, keeping the physical and mentally healthy worker

Image denoising based on nonlocal Bayesian singular value thresholding and Stein's unbiased risk estimator

© 1992-2012 IEEE. Singular value thresholding (SVT)- or nuclear norm minimization (NNM)-based nonlocal image denoising methods often rely on the precise estimation of the noise variance. However, most existing methods either assume that the noise variance is known or require an extra step to estimate it. Under the iterative regularization framework, the error in the noise variance estimate propagates and accumulates with each iteration, ultimately degrading the overall denoising performance. In addition, the essence of these methods is still least squares estimation, which can cause a very high mean-squared error (MSE) and is inadequate for handling missing data or outliers. In order to address these deficiencies, we present a hybrid denoising model based on variational Bayesian inference and Stein's unbiased risk estimator (SURE), which consists of two complementary steps. In the first step, the variational Bayesian SVT performs a low-rank approximation of the nonlocal image patch matrix to simultaneously remove the noise and estimate the noise variance. In the second step, we modify the conventional SURE full-rank SVT and its divergence formulas for rank-reduced eigen-triplets to remove the residual artifacts. The proposed hybrid BSSVT method achieves better performance in recovering the true image compared with state-of-the-art methods