433 research outputs found
Verification of ZVS boost converter with resonant circuit & modelling of an accurate two-diode PV array system simulator using MATLAB simulink
This thesis proposes a MATLAB Simulink simulator for Photo Voltaic (PV) Array system. The main contribution is the utilisation of a Two-Diode model to represent a PV cell. This model is preferred because of its better accuracy at low irradiance levels. A PV of Kyocera (KC200GT) 50*10 Array is taken & the characteristics curves are plotted. The same simulator can be interfaced with MPPT algorithms & Power Electronics converters for better efficiency. The P-V & I-V Curves of this simulator is found in exact with that given by the manufacturers. It is expected that the proposed work can be very useful for PV professionals who require a simple, fast & accurate PV simulator in order to design their systems. A detailed analysis of a resonant circuit based soft-switching boost-converter for PV applications is also performed. The converter operates at Zero Voltage Switching (ZVS) turn-on and turn-off of the main switch, & Zero Current Switching (ZCS) turn-on and ZVS turn-off of the auxiliary switch due to resonant circuit incorporated into the circuit. Detailed operation of the converters, analysis of various modes, simulation as well as experimental results for the design has also been aptly presented. The systems are modelled & simulated in MATLAB 2013a 64-bit version and the output waveforms are shown
Spectrum of uropathogens and their antibiotic sensitivity pattern in diabetes mellitus patients at a tertiary care hospital in Odisha, India
Background: Diabetes Mellitus is the most common endocrine disorder involving almost all systems of body. Untreated or poorly treated Diabetics are susceptible to develop a series of complications responsible for raised morbidity and mortality. Diabetes Mellitus has a number of long term effects on the Genitourinary system. Urinary tract infections have long been recognised as a significant problem in patients with Diabetes Mellitus.Methods: Prospective observational study. Diabetic patients with culture positive UTI were included. Gestational diabetes, Immunocompromised patients and patients with congenital renal anatomical abnormalities were excluded.Results: Authors included 211 numbers of culture positive UTI among diabetic patients. Out of which, 65 were male and 146 were female. Maximum number of patients belong to 56-65 years age group. Escherichia coli was the predominant organism isolated. Gram positive organisms showed 100% sensitivity to Vancomycin and Linezolid. Gram negative organisms showed 100% sensitivity to Polymyxin B.Conclusions: Genitourinary tract infection is not an infrequent complication seen in diabetes patients. Most common causative organism and their antibiotic sensitivity pattern should be done in tertiary care hospital for a better antibiotic policy
Methods of prediction and prevention of pre-eclampsia: Systematic reviews of accuracy and effectiveness literature with economic modelling
© Queen's Printer and Controller of HMSO 2008. This monograph may be freely reproduced for the purposes of private research and study and may be included in professional journals provided
that suitable acknowledgement is made and the reproduction is not associated with any form of advertising.Objectives: To investigate the accuracy of predictive tests for pre-eclampsia and the effectiveness of preventative interventions for pre-eclampsia. Also to assess the cost-effectiveness of strategies (test-intervention combinations) to predict and prevent pre-eclampsia. Data sources: Major electronic databases were searched to January 2005 at least. Review methods: Systematic reviews were carried out for test accuracy and effectiveness. Quality assessment was carried out using standard tools. For test accuracy, meta-analyses used a bivariate approach. Effectiveness reviews were conducted under the auspices of the Cochrane Pregnancy and Childbirth Group and used standard Cochrane review methods. The economic evaluation was from an NHS perspective and used a decision tree model. Results: For the 27 tests reviewed, the quality of included studies was generally poor. Some tests appeared to have high specificity, but at the expense of compromised sensitivity. Tests that reached specificities above 90% were body mass index > 34, α-foetoprotein and uterine artery Doppler (bilateral notching). The only Doppler test with a sensitivity of over 60% was resistance index and combinations of indices. A few tests not commonly found in routine practice, such as kallikreinuria and SDS-PAGE proteinuria, seemed to offer the promise of high sensitivity, without compromising specificity, but these would require further investigation. For the 16 effectiveness reviews, the quality of included studies was variable. The largest review was of antiplatelet agents, primarily low-dose aspirin, and included 51 trials (36,500 women). This was the only review where the intervention was shown to prevent both preeclampsia and its consequences for the baby. Calcium supplementation also reduced the risk of preeclampsia, but with some uncertainty about the impact on outcomes for the baby. The only other intervention associated with a reduction in RR of pre-eclampsia was rest at home, with or without a nutritional supplement, for women with normal blood pressure. However, this review included just two small trials and its results should be interpreted with caution. The cost of most of the tests was modest, ranging from £5 for blood tests such as serum uric acid to approximately £20 for Doppler tests. Similarly, the cost of most interventions was also modest. In contrast, the best estimate of additional average cost associated with an average case of pre-eclampsia was high at approximately £9000. The results of the modelling revealed that prior testing with the test accuracy sensitivities and specificities identified appeared to offer little as a way of improving cost-effectiveness. Based on the evidence reviewed, none of the tests appeared sufficiently accurate to be clinically useful and the results of the model favoured no-test/treat-all strategies. Rest at home without any initial testing appeared to be the most cost-effective 'test-treatment' combination. Calcium supplementation to all women, without any initial testing, appeared to be the second most cost-effective. The economic model provided little support that any form of Doppler test has sufficiently high sensitivity and specificity to be cost-effective for the early identification of pre-eclampsia. It also suggested that the pattern of cost-effectiveness was no different in high-risk mothers than the low-risk mothers considered in the base case. Conclusions: The tests evaluated are not sufficiently accurate, in our opinion, to suggest their routine use in clinical practice. Calcium and antiplatelet agents, primarily low-dose aspirin, were the interventions shown to prevent pre-eclampsia. The most cost-effective approach to reducing pre-eclampsia is likely to be the provision of an effective, affordable and safe intervention applied to all mothers without prior testing to assess levels of risk. It is probably premature to suggest the implementation of a treat-all intervention strategy at present, however the feasibility and acceptability of this to women could be explored. Rigorous evaluation is needed of tests with modest cost whose initial assessments suggest that they may have high levels of both sensitivity and specificity. Similarly, there is a need for high-quality, adequately powered randomised controlled trials to investigate whether interventions such as advice to rest are indeed effective in reducing pre-eclampsia. In future, an economic model should be developed that considers not just pre-eclampsia, but other related outcomes, particularly those relevant to the infant such as perinatal death, preterm birth and small for gestational age. Such a modelling project should make provision for primary data collection on the safety of interventions and their associated costs.National Institute for Health Researc
Frost maintains forests and grasslands as alternate states in a montane tropical forestâgrassland mosaic; but alien tree invasion and warming can disrupt this balance
1. Forestâgrassland mosaics, with abrupt boundaries between the two vegetation types, occur across the globe. Fire and herbivory are widely considered primary drivers that maintain these mosaics by limiting tree establishment in grasslands, while edaphic factors and frosts are generally considered to be secondary factors that reinforce these effects. However, the relative importance of these drivers likely varies across systems. In particular, although frost is known to occur in many montane tropical mosaics, experimental evidence for its role as a driving factor is limited.
2. We used replicated in situ transplant and warming experiments to examine the role of microclimate (frost and freezing temperatures) and soil in influencing germination and seedling survival of both native forest trees and alien invasive Acacia trees in grasslands of a tropical montane forestâgrassland mosaic in the Western Ghats of southern India.
3. Seed germination of both native and alien tree species was higher in grasslands regardless of soil type, indicating that germination was not the limiting stage to tree establishment. However, irrespective of soil type, native seedlings in grasslands incurred high mortality following winter frosts and freezing temperatures relative to native seedlings in adjoining forests where freezing temperatures did not occur. Seedling survival through the tropical winter was thus a primary limitation to native tree establishment in grasslands. In contrast, alien Acacia seedlings in grasslands incurred much lower levels of winter mortality. Experimental nightâtime warming in grasslands significantly enhanced overâwinter survival of all tree seedlings, but increases were much greater for alien Acacia than for native tree seedlings.
4. Synthesis. Our results provide evidence for a primary role for frost and freezing temperatures in limiting tree establishment in grasslands of this tropical montane forestâgrassland mosaic. Future increases in temperature are likely to release trees from this limitation and favour tree expansion into grasslands, with rates of expansion of nonânative Acacia likely to be much greater than that of native trees. We suggest that studies of frost limitation to plant establishment are needed across a range of tropical ecosystems to reâevaluate the general importance of frost as a driver of vegetation transitions in the tropics
Genome-wide development and deployment of informative intron-spanning and intron-length polymorphism markers for genomics-assisted breeding applications in chickpea
The discovery and large-scale genotyping of informative gene-based markers is essential for rapid delineation of genes/QTLs governing stress tolerance and yield component traits in order to drive genetic enhancement in chickpea. A genome-wide 119169 and 110491 ISM (intron-spanning markers) from 23129 desi and 20386 kabuli protein-coding genes and 7454 in silico InDel (insertion-deletion) (1â45-bp)-based ILP (intron-length polymorphism) markers from 3283 genes were developed that were structurally and functionally annotated on eight chromosomes and unanchored scaffolds of chickpea. A much higher amplification efficiency (83%) and intra-specific polymorphic potential (86%) detected by these markers than that of other sequence-based genetic markers among desi and kabuli chickpea accessions was apparent even by a cost-effective agarose gel-based assay. The genome-wide physically mapped 1718 ILP markers assayed a wider level of functional genetic diversity (19â81%) and well-defined phylogenetics among domesticated chickpea accessions. The gene-derived 1424 ILP markers were anchored on a high-density (inter-marker distance: 0.65 cM) desi intra-specific genetic linkage map/functional transcript map (ICC 4958 Ă ICC 2263) of chickpea. This reference genetic map identified six major genomic regions harbouring six robust QTLs mapped on five chromosomes, which explained 11â23% seed weight trait variation (7.6â10.5 LOD) in chickpea. The integration of high-resolution QTL mapping with differential expression profiling detected six including one potential serine carboxypeptidase gene with ILP markers (linked tightly to the major seed weight QTLs) exhibiting seed-specific expression as well as pronounced up-regulation especially in seeds of high (ICC 4958) as compared to low (ICC 2263) seed weight mapping parental accessions. The marker information generated in the present study was made publicly accessible through a user-friendly web-resource, âChickpea ISM-ILP Marker Databaseâ. The designing of multiple ISM and ILP markers (2â5 markers/gene) from an individual gene (transcription factor) with numerous aforementioned desirable genetic attributes can widen the user-preference to select suitable primer combination for simultaneous large-scale assaying of functional allelic variation, natural allelic diversity, molecular mapping and expression profiling of genes among chickpea accessions. This will essentially accelerate the identification of functionally relevant molecular tags regulating vital agronomic traits for genomics-assisted crop improvement by optimal resource expenses in chickpea
An Overview of Non Starch Polysaccharide
Abstract Polysaccharides are macromolecules of monosaccharides linked by glycosidic bonds. Polysaccharides are widespread biopolymers, which quantitatively represent the most important group of nutrients in feed. These are major components of plant materials used in rations for monogastrics. Non-starch polysaccharides (NSP) contain Ă-glucans, cellulose, pectin and hemicellulose. NSP consist of both soluble and insoluble fractions. Soluble NSP of cereals such as wheat, barley and rye increases intestinal viscosity there by interfere with the digestive processes and exert strong negative effects on net utilisation of energy. NSP cannot be degraded by endogeneous enzymes and therefore reach the colon almost indigested. Insoluble NSP make up the bulk in the diets. NSP are known to posses anti-nutritional properties by either encapsulating nutrients and/or depressing overall nutrient digestibility through gastro-intestinal modifications
Randomized Trial of Early Detection and Treatment of Postpartum Hemorrhage
Background: Delays in the detection or treatment of postpartum hemorrhage can result in complications or death. A blood-collection drape can help provide objective, accurate, and early diagnosis of postpartum hemorrhage, and delayed or inconsistent use of effective interventions may be able to be addressed by a treatment bundle.Methods: We conducted an international, cluster-randomized trial to assess a multicomponent clinical intervention for postpartum hemorrhage in patients having vaginal delivery. The intervention included a calibrated blood-collection drape for early detection of postpartum hemorrhage and a bundle of first-response treatments (uterine massage, oxytocic drugs, tranexamic acid, intravenous fluids, examination, and escalation), supported by an implementation strategy (intervention group). Hospitals in the control group provided usual care. The primary outcome was a composite of severe postpartum hemorrhage (blood loss, â„1000 ml), laparotomy for bleeding, or maternal death from bleeding. Key secondary implementation outcomes were the detection of postpartum hemorrhage and adherence to the treatment bundle.Results:Â A total of 80 secondary-level hospitals across Kenya, Nigeria, South Africa, and Tanzania, in which 210,132 patients underwent vaginal delivery, were randomly assigned to the intervention group or the usual-care group. Among hospitals and patients with data, a primary-outcome event occurred in 1.6% of the patients in the intervention group, as compared with 4.3% of those in the usual-care group (risk ratio, 0.40; 95% confidence interval [CI], 0.32 to 0.50; P<0.001). Postpartum hemorrhage was detected in 93.1% of the patients in the intervention group and in 51.1% of those in the usual-care group (rate ratio, 1.58; 95% CI, 1.41 to 1.76), and the treatment bundle was used in 91.2% and 19.4%, respectively (rate ratio, 4.94; 95% CI, 3.88 to 6.28).Conclusions: Early detection of postpartum hemorrhage and use of bundled treatment led to a lower risk of the primary outcome, a composite of severe postpartum hemorrhage, laparotomy for bleeding, or death from bleeding, than usual care among patients having vaginal delivery
Randomized Trial of Early Detection and Treatment of Postpartum Hemorrhage
Background: Delays in the detection or treatment of postpartum hemorrhage can result in complications or death. A blood-collection drape can help provide objective, accurate, and early diagnosis of postpartum hemorrhage, and delayed or inconsistent use of effective interventions may be able to be addressed by a treatment bundle.Methods: We conducted an international, cluster-randomized trial to assess a multicomponent clinical intervention for postpartum hemorrhage in patients having vaginal delivery. The intervention included a calibrated blood-collection drape for early detection of postpartum hemorrhage and a bundle of first-response treatments (uterine massage, oxytocic drugs, tranexamic acid, intravenous fluids, examination, and escalation), supported by an implementation strategy (intervention group). Hospitals in the control group provided usual care. The primary outcome was a composite of severe postpartum hemorrhage (blood loss, â„1000 ml), laparotomy for bleeding, or maternal death from bleeding. Key secondary implementation outcomes were the detection of postpartum hemorrhage and adherence to the treatment bundle.Results:Â A total of 80 secondary-level hospitals across Kenya, Nigeria, South Africa, and Tanzania, in which 210,132 patients underwent vaginal delivery, were randomly assigned to the intervention group or the usual-care group. Among hospitals and patients with data, a primary-outcome event occurred in 1.6% of the patients in the intervention group, as compared with 4.3% of those in the usual-care group (risk ratio, 0.40; 95% confidence interval [CI], 0.32 to 0.50; P<0.001). Postpartum hemorrhage was detected in 93.1% of the patients in the intervention group and in 51.1% of those in the usual-care group (rate ratio, 1.58; 95% CI, 1.41 to 1.76), and the treatment bundle was used in 91.2% and 19.4%, respectively (rate ratio, 4.94; 95% CI, 3.88 to 6.28).Conclusions: Early detection of postpartum hemorrhage and use of bundled treatment led to a lower risk of the primary outcome, a composite of severe postpartum hemorrhage, laparotomy for bleeding, or death from bleeding, than usual care among patients having vaginal delivery
Free energy of binding of coiled-coil complexes with different electrostatic environments: the influence of force field polarisation and capping
Coiled-coils are well known proteinâprotein interaction motifs, with the leucine zipper region of activator protein-1 (AP-1) consisting of the c-Jun and c-Fos proteins being a typical example. Molecular dynamics (MD) simulations using the MM/GBSA method have been used to predict the free energy of interaction of these proteins. The influence of force field polarisation and capping on the predicted free energy of binding of complexes with different electrostatic environments (net charge) were investigated. Although both force field polarisation and peptide capping are important for the prediction of the absolute free energy of binding, peptide capping has the largest influence on the predicted free energy of binding. Polarisable simulations appear better suited to determine structural properties of the complexes of these proteins while non-polarisable simulations seem to give better predictions of the associated free energies of bindin
Evidence for perinatal and child health care guidelines in crisis settings: can Cochrane help?
<p>Abstract</p> <p>Background</p> <p>It is important that healthcare provided in crisis settings is based on the best available research evidence. We reviewed guidelines for child and perinatal health care in crisis situations to determine whether they were based on research evidence, whether Cochrane systematic reviews were available in the clinical areas addressed by these guidelines and whether summaries of these reviews were provided in Evidence Aid.</p> <p>Methods</p> <p>Broad internet searches were undertaken to identify relevant guidelines. Guidelines were appraised using AGREE and the clinical areas that were relevant to perinatal or child health were extracted. We searched The Cochrane Database of Systematic Reviews to identify potentially relevant reviews. For each review we determined how many trials were included, and how many were conducted in resource-limited settings.</p> <p>Results</p> <p>Six guidelines met selection criteria. None of the included guidelines were clearly based on research evidence. 198 Cochrane reviews were potentially relevant to the guidelines. These reviews predominantly addressed nutrient supplementation, breastfeeding, malaria, maternal hypertension, premature labour and prevention of HIV transmission. Most reviews included studies from developing settings. However for large portions of the guidelines, particularly health services delivery, there were no relevant reviews. Only 18 (9.1%) reviews have summaries in Evidence Aid.</p> <p>Conclusions</p> <p>We did not identify any evidence-based guidelines for perinatal and child health care in disaster settings. We found many Cochrane reviews that could contribute to the evidence-base supporting future guidelines. However there are important issues to be addressed in terms of the relevance of the available reviews and increasing the number of reviews addressing health care delivery.</p
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