951 research outputs found
Digital carrier demodulator employing components working beyond normal limits
In a digital device, having an input comprised of a digital sample stream at a frequency F, a method is disclosed for employing a component designed to work at a frequency less than F. The method, in general, is comprised of the following steps: dividing the digital sample stream into odd and even digital samples streams each at a frequency of F/2; passing one of the digital sample streams through the component designed to work at a frequency less than F where the component responds only to the odd or even digital samples in one of the digital sample streams; delaying the other digital sample streams for the time it takes the digital sample stream to pass through the component; and adding the one digital sample stream after passing through the component with the other delayed digital sample streams. In the specific example, the component is a finite impulse response filter of the order ((N + 1)/2) and the delaying step comprised passing the other digital sample streams through a shift register for a time (in sampling periods) of ((N + 1)/2) + r, where r is a pipline delay through the finite impulse response filter
Detection of signals by the digital integrate-and-dump filter with offset sampling
The Integrate and Dump Filter (IDF) is used as a matched filter for the detection of signals in additive white Gaussian noise. The performance of the digital integrate and dump filter is evaluated. The case considered is when symbol times are known and the sampling clock is free running at a constant rate, i.e., the sampling clock is not phase locked to the symbol clock. Degradations in the output signal to noise ratio of the digital implementation due to sampling rate, sampling offset, and finite bandwidth, resulting from the anti-aliasing low pass prefilter, are computed and compared with those of the analog counterpart. It is shown that the digital IDF performs within 0.6 dB of the ideal analog IDF whenever the prefilter bandwidth exceeds four times the symbol rate and when sampling is performed at the Nyquist rate. The loss can be reduced to 0.3 dB by doubling the sampling rate, where 0.2 dB loss results from finite bandwidth and 0.1 dB results from the digital IDF
Bis(4-methyl-3,5-diphenyl-1H-pyrazole-κN 2)silver(I) nitrate
In the title complex, [Ag(C16H14N2)2]NO3, the geometry around the AgI ion is T-shaped with two short Ag—N bonds to the pyrazole ligand and one long Ag—O bond to the nitrate anion. The crystal structure is stabilized by intermolecular N—H⋯O, C—H⋯O and C—H⋯π interactions
Vasopressin attenuates ischemia-reperfusion injury via reduction of oxidative stress and inhibition of mitochondrial permeability transition pore opening in rat hearts
Aim of this study was to investigate the involvement of the mitochondrial permeability transition pore (MPTP) and oxidative stress in the cardioprotective effect of vasopressin (AVP) on ischemia/reperfusion (I/R) injury. Anesthetized male wistar rats were subjected to regional 30 min ischemia and 120 min reperfusion and randomly divided into nine groups: (1) Control; saline was administered intravenously before ischemia, (2) vasopressin was administrated 10 min prior to ischemia, (3, 4) Atractyloside as MPTP opener, was injected 5 min prior to reperfusion without and with vasopressin, (5, 6) Cyclosporine A as a MPTP closer, was injected 5 min prior to reperfusion without and with vasopressin, (7) mitochondria were isolated from control group and CaCl2 was added as MPTP opener and swelling inducer, (8) isolated mitochondria from Control hearts was incubated with Cyclosporine A before adding the CaCl2 (9) CaCl2 was added to isolated mitochondria from vasopressin group. Infusion of vasopressin decreased infarct size (18.6±1.7% vs. control group 37.6±2.4%), biochemical parameters [LDH (Lactate Dehydrogenase), CK-MB (Creatine Kinase-MB) and MDA (Malondialdehyde) plasma levels, PAB (Prooxidant-antioxidant balance)] compared to control group. Atactyloside suppressed the cardioprotective effect of vasopressin (32.5±1.9% vs. 18.6±1.7%) but administration of the Cyclosporine A without and with vasopressin significantly reduced infarct size to 17.7±4% (P<0.001) and 22.7±3% (P<0.01) respectively, vs. 37.6±2.4% in control group. Also, vasopressin, similar to Cyclosporine A, led to decrease in CaCl2-induced swelling. It seems that vasopressin through antioxidant effect and MPTP inhibition has created a cardioprotection against ischemia/reperfusion injuries. © 2015 Elsevier B.V. All rights reserved
Bis[bis(3,5-dimethyl-1H-pyrazol-1-yl)borato]cobalt(II)
The asymmetric unit of the title compound, [Co(C10H16BN4)2], comprises one unit of the complex. The geometry around the CoII ion is a distorted tetrahedron. The dihedral angles between the pyrazole rings in the two ligands are 47.19 (15) and 47.20 (16)°, while that between the coordination planes is 79.77 (7)°
Clinical decision tools are needed to identify HIV-positive patients at high risk for poor outcomes after initiation of antiretroviral therapy
Over the past decade, the scale-up of HIV programs in resource-limited settings has been remarkable, with over 17 million persons initiating lifesaving antiretroviral therapy (ART) by the end of 2015 . However, in order to reduce HIV-related morbidity and mortality and decrease the number of new infections, it is critical to double the number of HIV-positive patients on treatment by 2020. It is equally important for health outcomes among children and adults on ART to be optimized. To achieve these two goals—i.e., a massive increase in the number of patients on ART as well as an enhancement in the quality of care—the global health community has recognized the need for tailored HIV services to meet the unique needs of different patient groups, often referred to as differentiated models of service delivery
Locally Preferred Structure and Frustration in Glassforming Liquids: A Clue to Polyamorphism?
We propose that the concept of liquids characterized by a given locally
preferred structure (LPS) could help in understanding the observed phenomenon
of polyamorphism. ``True polyamorphism'' would involve the competition between
two (or more) distinct LPS, one favored at low pressure because of its low
energy and one favored at high pressure because of its small specific volume,
as in tetrahedrally coordinated systems. ``Apparent polyamorphism'' could be
associated with the existence of a poorly crystallized defect-ordered phase
with a large unit cell and small crystallites, which may be illustrated by the
metastable glacial phase of the fragile glassformer triphenylphosphite; the
apparent polyamorphism might result from structural frustration, i. e., a
competition between the tendency to extend the LPS and a global constraint that
prevents tiling of the whole space by the LPS.Comment: 11, 6 figures, Proceedings of the Conference "Horizons in Complex
Systems", Messina; in honor of the 60th birthday of H.E. Stanle
Polymorphism of calpastatin gene in Arabic sheep using PCR- RFLP
Calpastatin has been known as candidate gene in muscle growth efficiency and meat quality. This gene has been located to chromosome 5 of sheep. In order to evaluate the calpastatin gene polymorphism, random blood sample were collected from 111 Arabic ram sheep from different regions. The DNA extraction was based on Boom et al. (1989) method. Exon and entron I from L domain of the ovine calpastatin gene was amplified to produce a 622 bp fragment. The PCR products were electrophoresed on 1.2% agarose gel and stained by etidium bromide. Then, they were digested with restriction enzyme MspI and then electrophoresed on 2.5% agarose gel with ethidium bromide and revealed two alleles, allele A and allele B. Data were analysed using PopGene32 package. In this population, AA, AB, BB genotype have been identified with the 70.27, 28.82, 0.9% frequencies. A and B allele’s frequencies were 0.85, 0.15, respectively. The population was found to follow Hardy-Weinberg equilibrium
The influence of HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV-positive individuals
<p>Abstract</p> <p>Objective</p> <p>This study was performed to investigate the impact of HAART versus no HAART and nucleoside free versus nucleoside containing HAART on the efficacy and safety of pegylated interferon and ribavirin therapy for the treatment of chronic HCV infection in HIV/HCV co-infected patients. In addition a control group of HCV mono-infected patients undergoing anti-HCV therapy was evaluated.</p> <p>Methods</p> <p>Multicenter, partially randomized, controlled clinical trial. HIV-negative and -positive patients with chronic HCV infection were treated with pegylated interferon alfa-2a and ribavirin (800 - 1200 mg/day) for 24 - 48 weeks in one of four treatment arms: HIV-negative (A), HIV-positive without HAART (B) and HIV-positive on HAART (C). Patients within arm C were randomized to receive open label either a nucleoside containing (C1) or a nucleoside free HAART (C2).</p> <p>Results</p> <p>168 patients were available for analysis. By intent-to-treat analysis similar sustained virological response rates (SVR, negative HCV-RNA 24 weeks after the end of therapy) were observed comparing HIV-negative and -positive patients (54% vs. 54%, p = 1.000). Among HIV-positive patients SVR rates were similar between patients off and on HAART (57% vs. 52%, p = 0.708). Higher SVR rates were observed in patients on a nucleoside free HAART compared to patients on a nucleoside containing HAART, though confounding could not be ruled out and in the intent-to-treat analysis the difference was not statistically significant (64% vs. 46%, p = 0.209).</p> <p>Conclusions</p> <p>Similar response rates for HCV therapy can be achieved in HIV-positive and -negative patients. Patients on nucleoside free HAART reached at least equal rates of sustained virological response compared to patients on standard HAART.</p
Anxiety as a consequence of modern dietary pattern in adults in Tehran-Iran
Food intake patterns in relation to mental health have already been revealed. To investigate the relationship between processed food consumption behavior and anxiety disorder, a cross sectional study was conducted. Overall, 1782 young adults aged 18-35 years were randomly selected using cluster sampling method from 22 districts of Tehran Iran in 2011. Diet assessment was done using a 24 hour recall questionnaire in two times with a week interval. Anxiety level was determined using the validated Speilburger test (Persian version). A proportional odds regression model was used to assess the effect of processed food consumption on anxiety variables. A significant statistical difference was found between men and women in terms of processed food consumption (p<0.001). Adjusting for age, total calorie intake, gender, body mass index, socioeconomic status, and history of sedative drug consumption as well as mental health disorders, the proportional odds regression model showed a significant relationship between increased consumption of processed foods and anxiety (OR = 4.73, 95 CI: 2.89-12.54 for state and OR = 4.91, 95 CI: 2.88-13.99 for trait). Identification, modification and adjusting incorrect food patterns in the community could be considered as valuable steps to turn down nutritional-based health difficulties. (C) 2012 Elsevier Ltd. All rights reserved
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