76 research outputs found

    Performance of SDR Transceiver Using Different Modulation Techniques

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    The paper describes about the design and performance of transceiver for the software defined radio (SDR).The sensible solution for reconfiguring radio is the SDR. It uses identical hardware platform to perform various tasks.The design is simulated using MATLABSimulink and performance is analyzed based on the error rate against signal to noise ratio.The design is investigated with 40MHz intermediate frequency transmission

    A prospective study of effect of amniotic fluid index less than 5 at term on perinatal outcome

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    Background: To study the effect of oligohydramnios in pregnancy and its value in predicting adverse perinatal outcome.Methods: A prospective case control study of pregnancy outcome in 100 cases with ultrasound diagnosis of oligohydramnios at term compared with 100 controls with no oligohydramnios. The study was done over a period of 3 years at SSMC Tumkur, India.Results: Oligohydramnios at term is associated with poor perinatal outcome. Significant increase in abnormal foetal heart rate, meconium stained liquor, delivery by cesarean section, low Apgar intrauterine growth restriction (IUGR), increased admissions to  neonatal intensive-care unit (NICU) were seen in study group, however perinatal mortality was more in study group but not statistically significant (P=0.31)Conclusions: AFI <5 at term is an important fetal surveillance methods to identify poor perinatal outcome and thereby makes possible intervention so as to reduce perinatal morbidity and mortality

    One-Pot Palladium-Catalyzed Ligand- and Metal-Oxidant-Free Aerobic Oxidative Isocyanide Insertion Leading to 2-Amino-substituted-4(3H)-quinazolinones

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    An efficient, ligand- and metal-oxidant-free, one-pot, cascade aerobic oxidative, palladium-catalyzed, multicomponent reaction has been developed through isocyanide insertion of less active secondary amide and aromatic amine, which leads to 2-amino-substituted-4(3H)-quinazolinones. This approach proves to be one of the simplest methods for the synthesis of this class of valuable bioactive heterocyclic scaffolds

    A quasi-experimental study to assess the effect of a local anesthetic proparacaine on tropicamide-induced pupillary dilation

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    Background: Dilating the pupil is one of the most commonly practiced methods among ophthalmologists to examine the eye especially the posterior segment of the eye. Here we conducted a study to know the clinical effect of proparacaine, a local anesthetic, on tropicamide-induced pupillary dilation.Methods: A Quasi-experimental study was conducted on 57 subjects aged between 20 and 70 years. Study was done over a period of 3 months (February 14 - April 14) at a tertiary health care center in Bagalkot after obtaining institutional ethical committee clearance. Proparacaine was instilled in one eye (right eye) before instilling tropicamide and the other eye with a placebo (normal saline). Pupil diameter was measured using a pupillary gauge at 0, 15, and 30 mins. Results were analyzed using unpaired Student’s t-test.Results: The mean clinically efficient pupillary diameter at the end of 15 mins in proparacaine instilled eye was 5.56±0.5 and in control eye was 5.25±0.45 mm with t value 8.13 (p<0.001) which was statistically significant. And at the end of 30 mins pupillary diameter in the study group was 7.96±0.43 mm and in the control group was 7.83±0.43 mm with t value of 4.115 (p<0.001) which was also statistically significant.Conclusions: Therefore, we do recommend the use of proparacaine before instilling tropicamide for faster pupillary dilation

    ANTIBACTERIAL ACTIVITY OF SYNTHESIZED SILVER NANOPARTICLES BY SIMAROUBAGLAUCA AGAINST PATHOGENIC BACTERIA

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    Objective: The present study outline the plant-mediated synthesis of silver nanoparticles (AgNPs) using leaf extract Simaroubaglauca, which act as both reducing and stabilizing agent.Methods: Formation of silver nanoparticles was confirmed by primarily by Ultraviolet/visible spectroscopy. X-ray diffraction studies revealed the crystallinity of the nanoparticles. The scanning electron microscopy was carried out to determine the mean particle size, as well as the morphology of the NPs and the composition of elements, was studied with Energy Dispersive X-ray analysis (EDS).Results: The silver nanoparticles were spherical in shape with a mean size of 23 nm. The EDS showed strong optical absorption peak at 3keV and it was confirmed the formation of AgNPs. The synthesised AgNPs further utilized for the evaluation of antibacterial activity and shown significant antibacterial activity against Escherichia coli, Pseudomonas aeruginosa, Enterobacter and Klebsiella pneumonia at 50 µg/ml and 100µg/ml concentrations.Conclusion: The synthesised silver nanoparticles have been characterised by UV-vis, SEM-EDAX and XRD to determine the sizes and shapes of the silver nanoparticles

    Broadband Photodetection in Graphene

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    Graphene, a single-atom-thick plane of carbon, has unique optoelectronic properties that result in a variety of potential photonic applications, such as optical modulators, plasmonic devices and THz emitters. In this thesis, the light-matter interaction in monolayer graphene and the subsequent photoexcited charge carrier transport are studied, and it is found that graphene has unique advantages for hot-electron photothermoelectric detection. Particularly promising is detection of terahertz (THz) radiation, in which graphene devices may offer significant advantages over existing technology in terms of speed and sensitivity. By using a tilted angle shadow evaporation technique, bi-metal contacted graphene photodetectors are realized experimentally. Efficient photodetection via the hot-electron photothermoelectric effect is demonstrated at room temperature across a broad frequency range (THz to near infrared). For THz detection, the best device shows sensitivity exceeding 10 V/W (700 V/W) and noise equivalent power less than 1100 pW/Hz1/2 (20 pW/Hz1/2), referenced to the incident (absorbed) power, implying a performance competitive with the best room-temperature THz detectors for an optimally absorbing device, while time-resolved measurements indicate that the graphene detector is eight to nine orders of magnitude faster than those. To increase the absorption and quantum efficiency, large area epitaxial graphene micro-ribbon array photodetectors are designed for resonant plasmon excitation in the THz range. By tailoring the orientation of the graphene ribbons with respect to an array of sub-wavelength bimetallic electrodes, a condition is achieved in which the plasmonic mode can be efficiently excited by an incident wave polarized perpendicular to the electrode array. The sensitivity of the detector is enhanced when the plasmon resonance frequency, which is tunable by adjusting the gate voltage, matches with the frequency of the incident radiation

    Assessment of epidemic projections using recent HIV survey data in South Africa: a validation analysis of ten mathematical models of HIV epidemiology in the antiretroviral therapy era

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    Background Mathematical models are widely used to simulate the eff ects of interventions to control HIV and to project future epidemiological trends and resource needs. We aimed to validate past model projections against data from a large household survey done in South Africa in 2012. Methods We compared ten model projections of HIV prevalence, HIV incidence, and antiretroviral therapy (ART) coverage for South Africa with estimates from national household survey data from 2012. Model projections for 2012 were made before the publication of the 2012 household survey. We compared adult (age 15–49 years) HIV prevalence in 2012, the change in prevalence between 2008 and 2012, and prevalence, incidence, and ART coverage by sex and by age groups between model projections and the 2012 household survey. Findings All models projected lower prevalence estimates for 2012 than the survey estimate (18·8%), with eight models’ central projections being below the survey 95% CI (17·5–20·3). Eight models projected that HIV prevalence would remain unchanged (n=5) or decline (n=3) between 2008 and 2012, whereas prevalence estimates from the household surveys increased from 16·9% in 2008 to 18·8% in 2012 (diff erence 1·9, 95% CI –0·1 to 3·9). Model projections accurately predicted the 1·6 percentage point prevalence decline (95% CI –0·3 to 3·5) in young adults aged 15–24 years, and the 2·2 percentage point (0·5 to 3·9) increase in those aged 50 years and older. Models accurately represented the number of adults on ART in 2012; six of ten models were within the survey 95% CI of 1·54–2·12 million. However, the diff erential ART coverage between women and men was not fully captured; all model projections of the sex ratio of women to men on ART were lower than the survey estimate of 2·22 (95% CI 1·73–2·71). Interpretation Projections for overall declines in HIV epidemics during the ART era might have been optimistic. Future treatment and HIV prevention needs might be greater than previously forecasted. Additional data about service provision for HIV care could help inform more accurate projections

    LXR Deficiency Confers Increased Protection against Visceral Leishmania Infection in Mice

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    Leishmania spp. are protozoan single-cell parasites that are transmitted to humans by the bite of an infected sand fly, and can cause a wide spectrum of disease, ranging from self-healing skin lesions to potentially fatal systemic infections. Certain species of Leishmania that cause visceral (systemic) disease are a source of significant mortality worldwide. Here, we use a mouse model of visceral Leishmania infection to investigate the effect of a host gene called LXR. The LXRs have demonstrated important functions in both cholesterol regulation and inflammation. These processes, in turn, are closely related to lipid metabolism and the development of atherosclerosis. LXRs have also previously been shown to be involved in protection against other intracellular pathogens that infect macrophages, including certain bacteria. We demonstrate here that LXR is involved in susceptibility to Leishmania, as animals deficient in the LXR gene are much more resistant to infection with the parasite. We also demonstrate that macrophages lacking LXR kill parasites more readily, and make higher levels of nitric oxide (an antimicrobial mediator) and IL-1β (an inflammatory cytokine) in response to Leishmania infection. These results could have important implications in designing therapeutics against this deadly pathogen, as well as other intracellular microbial pathogens

    Assessment of epidemic projections using recent HIV survey data in South Africa: A validation analysis of ten mathematical models of HIV epidemiology in the antiretroviral therapy era

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    Background: Mathematical models are widely used to simulate the effects of interventions to control HIV and to project future epidemiological trends and resource needs. We aimed to validate past model projections against data from a large household survey done in South Africa in 2012. Methods: We compared ten model projections of HIV prevalence, HIV incidence, and antiretroviral therapy (ART) coverage for South Africa with estimates from national household survey data from 2012. Model projections for 2012 were made before the publication of the 2012 household survey. We compared adult (age 15-49 years) HIV prevalence in 2012, the change in prevalence between 2008 and 2012, and prevalence, incidence, and ART coverage by sex and by age groups between model projections and the 2012 household survey. Findings: All models projected lower prevalence estimates for 2012 than the survey estimate (18·8%), with eight models' central projections being below the survey 95% CI (17·5-20·3). Eight models projected that HIV prevalence would remain unchanged (n=5) or decline (n=3) between 2008 and 2012, whereas prevalence estimates from the household surveys increased from 16·9% in 2008 to 18·8% in 2012 (difference 1·9, 95% CI -0·1 to 3·9). Model projections accurately predicted the 1·6 percentage point prevalence decline (95% CI -0·3 to 3·5) in young adults aged 15-24 years, and the 2·2 percentage point (0·5 to 3·9) increase in those aged 50 years and older. Models accurately represented the number of adults on ART in 2012; six of ten models were within the survey 95% CI of 1·54-2·12 million. However, the differential ART coverage between women and men was not fully captured; all model projections of the sex ratio of women to men on ART were lower than the survey estimate of 2·22 (95% CI 1·73-2·71). Interpretation: Projections for overall declines in HIV epidemics during the ART era might have been optimistic. Future treatment and HIV prevention needs might be greater than previously forecasted. Additional data about service provision for HIV care could help inform more accurate projections. Funding: Bill & Melinda Gates Foundation
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