194 research outputs found
Gas identification based on bias induced hysteresis of a gas-sensitive SiC field effect transistor
In this work dynamic variation of gate bias is used on a gas-sensitive SiC
field effect transistor ("GasFET") to optimize its sensitivity and
increase its selectivity. Gate bias ramps introduce strong hysteresis in the
sensor signal. The shape of this hysteresis is shown to be an appropriate
feature both for the discrimination of various gases (ammonia, carbon
monoxide, nitrogen monoxide and methane) as well as for different gas
concentrations (250 and 500 ppm). The shape is very sensitive to ambient
conditions as well as to the bias sweep rate. Thus, the influences of oxygen
concentration, relative humidity, sensor temperature and cycle duration,
i.e., sweep rate, are investigated and reasons for the observed signal
changes, most importantly the existence of at least two different and
competing processes taking place simultaneously, are discussed. Furthermore,
it is shown that even for very fast cycles, in the range of seconds, the
gas-induced shape change in the signal is strong enough to achieve a
reliable separation of gases using gate bias cycled operation and linear
discriminant analysis (LDA) making this approach suitable for practical
application
How Nursing Affects Medicareās Outcome-Based Hospital Payments
Improving value is one of the central aims of recent and ongoing health care reform. In our last LDI/INQRI Brief, we reviewed the evidence of the role of nurses in increasing the value of health care. In this companion brief, we dig deeper into the three reimbursement strategies that Medicare uses to align hospital financial incentives with quality of care, and we calculate the potential effects of nursing-sensitive quality indicators on hospital payments
Survey on Plum pox virus in Norway
In 1998 Plum pox virus (PPV) was detected for the first time in Norway. Virus-like symptoms were observed on several trees in a collection of plum cultivars at NjĆøs Research Station in the Sogn og Fjordane County in West Norway. The Norwegian Food Safety Authority and the Norwegian Crop Research Institute immediately started surveying other variety collections around the country, nuclear stock material and orchards in all important plum-growing areas. Since 1998 we have surveyed the main part of the commercial plum orchards in Norway. About 75 000 individual trees have been tested. About 1 % of the trees have been found infected by PPV. Only the PPV-D strain has been found. It is suspected that the main infection source was infected plums or apricots imported to NjĆøs around 1970 or earlier. In most plum orchards in Norway, the spread of PPV by aphids is relatively slow. Therefore, we expect to be able to eradicate PPV from commercial plum orchards in the near future. The eradication work is continuing.Keywords: Plum pox virus, surve
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Use of and attitudes towards the prescribing guidelines booklet in primary health care doctors
S6K1 controls pancreatic Ī² cell size independently of intrauterine growth restriction
Type 2 diabetes mellitus (T2DM) is a worldwide heath problem that is characterized by insulin resistance and the eventual loss of Ī² cell function. As recent studies have shown that loss of ribosomal protein (RP) S6 kinase 1 (S6K1) increases systemic insulin sensitivity, S6K1 inhibitors are being pursued as potential agents for improving insulin resistance. Here we found that S6K1 deficiency in mice also leads to decreased Ī² cell growth, intrauterine growth restriction (IUGR), and impaired placental development. IUGR is a common complication of human pregnancy that limits the supply of oxygen and nutrients to the developing fetus, leading to diminished embryonic Ī² cell growth and the onset of T2DM later in life. However, restoration of placental development and the rescue of IUGR by tetraploid embryo complementation did not restore Ī² cell size or insulin levels in S6K1-/- embryos, suggesting that loss of S6K1 leads to an intrinsic Ī² cell lesion. Consistent with this hypothesis, reexpression of S6K1 in Ī² cells of S6K1-/- mice restored embryonic Ī² cell size, insulin levels, glucose tolerance, and RPS6 phosphorylation, without rescuing IUGR. Together, these data suggest that a nutrient-mediated reduction in intrinsic Ī² cell S6K1 signaling, rather than IUGR, during fetal development may underlie reduced Ī² cell growth and eventual development of T2DM later in life
Ohmic contact properties of magnetron sputtered Ti3SiC2 on n- and p-type 4H-silicon carbide
Obesity and nocturnal gastro-oesophageal reflux are related to onset of asthma and respiratory symptoms
Several studies have identified obesity as a risk factor for asthma in both children and adults. An increased prevalence of asthma in subjects with gastro-oesophageal reflux (GOR) and obstructive sleep apnoea syndrome has also been reported. The aim of this investigation was to study obesity, nocturnal GOR and snoring as independent risk factors for onset of asthma and respiratory symptoms in a Nordic population. In a 5-10 yr follow-up study of the European Community Respiratory Health Survey in Iceland, Norway, Denmark, Sweden and Estonia, a postal questionnaire was sent to previous respondents. A total of 16,191 participants responded to the questionnaire. Reported onset of asthma, wheeze and night-time symptoms as well as nocturnal GOR and habitual snoring increased in prevalence along with the increase in body mass index (BMI). After adjusting for nocturnal GOR, habitual snoring and other confounders, obesity (BMI >30) remained significantly related to the onset of asthma, wheeze and night-time symptoms. Nocturnal GOR was independently related to the onset of asthma and in addition, both nocturnal GOR and habitual snoring were independently related to onset of wheeze and night-time symptoms. This study adds evidence to an independent relationship between obesity, nocturnal gastro-oesophageal reflux and habitual snoring and the onset of asthma and respiratory symptoms in adults
Exposure to Apoptotic Activated CD4+ T Cells Induces Maturation and APOBEC3G- Mediated Inhibition of HIV-1 Infection in Dendritic Cells
Dendritic cells (DCs) are activated by signaling via pathogen-specific receptors or exposure to inflammatory mediators. Here we show that co-culturing DCs with apoptotic HIV-infected activated CD4+ T cells (ApoInf) or apoptotic uninfected activated CD4+ T cells (ApoAct) induced expression of co-stimulatory molecules and cytokine release. In addition, we measured a reduced HIV infection rate in DCs after co-culture with ApoAct. A prerequisite for reduced HIV infection in DCs was activation of CD4+ T cells before apoptosis induction. DCs exposed to ApoAct or ApoInf secreted MIP-1Ī±, MIP-1Ī², MCP-1, and TNF-Ī±; this effect was retained in the presence of exogenous HIV. The ApoAct-mediated induction of co-stimulatory CD86 molecules and reduction of HIV infection in DCs were partially abrogated after blocking TNF-Ī± using monoclonal antibodies. APOBEC3G expression in DCs was increased in co-cultures of DCs and ApoAct but not by apoptotic resting CD4+ T cells (ApoRest). Silencing of APOBEC3G in DC abrogated the HIV inhibitory effect mediated by ApoAct. Sequence analyses of an env region revealed significant induction of G-to-A hypermutations in the context of GG or GA dinucleotides in DNA isolated from DCs exposed to HIV and ApoAct. Thus, ApoAct-mediated DC maturation resulted in induction of APOBEC3G that was important for inhibition of HIV-infection in DCs. These findings underscore the complexity of differential DC responses evoked upon interaction with resting as compared with activated dying cells during HIV infection
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