मानसून के दौरान बुकानीर ऐंचोवी का उपतट प्रवास

कृपया पूरा लेखा पढ

Analysis of Metallised Propellant Ignition Process under Conductive Heating

Ignition of a composite aluminised propellant (AP-HTPB-Al) in stagnant hot air is analysed theoretically, based on solid phase and gas phase theories. According to solid phase theory, ignition is due to reaction of the propellant in the solid phase at elevated temperatures. One-dimensional transient solid phase energy equation is solved to obtain the surface temperature profile of the propellant. By gas phase theory, an exothermic gas phase reaction, adjacent to the propellant surface, is considered responsible for the ignition. The changes in temperature and concentrations in the gas phase and the temperature profile below the propellant surface during the pre-ignition induction period are considered. Equations of energy and concentrations of reactants have been solved to obtain the species concentration and temperature profiles in the gas phase. An experimental investigation of the ignition of AP-HTPB-Al propellant is also carried out in a shock tube under end-mount conditions. Pressure and temperature ranges were 6-16 bar and 1500-3000 K, respectively. A comparison of the experimental data with predicted results shows that the ignition in an oxidizing atmosphere is by gas phase reaction, whereas in an inert atmosphere, solid phase reaction may be predominant

Microstructural and compositional analysis of strontium-doped lead zirconate titanate thin films on gold-coated silicon substrates

This article discusses the results of transmission electron microscopy (TEM)-based characterization of strontium-doped lead zirconate titanate (PSZT) thin films. The thin films were deposited by radio frequency magnetron sputtering at 300°C on gold-coated silicon substrates, which used a 15 nm titanium adhesion layer between the 150 nm thick gold film and (100) silicon. The TEM analysis was carried out using a combination of high-resolution imaging, energy filtered imaging, energy dispersive X-ray (EDX) analysis, and hollow cone illumination. At the interface between the PSZT films and gold, an amorphous silicon-rich layer (about 4 nm thick) was observed, with the film composition remaining uniform otherwise. The films were found to be polycrystalline with a columnar structure perpendicular to the substrate. Interdiffusion between the bottom metal layers and silicon was observed and was confirmed using secondary ion mass spectrometry. This occurs due to the temperature of deposition (300°C) being close to the eutectic point of gold and silicon (363°C). The diffused regions in silicon were composed primarily of gold (analyzed by EDX) and were bounded by (111) silicon planes, highlighted by the triangular diffused regions observed in the two-dimensional TEM image

ASSESSMENT OF THE INCIDENCE AND PREVALENCE OF DRY EYES IN DIABETIC INDIVIDUALS AND IT’S EFFECT ON VISUAL ACUITY

Objective: To find out the incidence and prevalence of Dry Eyes in Diabetic patients and find out its effect on visual acuity. Methods: A prospective study was conducted in Saveetha Medical College and Hospital. Schirmer’s test was done for 100 diabetic patients taking part in the research. Those with dry eyes were tested for their visual acuity and were asked to fill a questionnaire based on associated ocular symptoms. The collected data were analysed using Microsoft Excel. Results: There is about an incidence of 82% of dry eyes in diabetic patients. It’s more prevalent among elderly women. There seems to be a significant effect of dry eys on visual acuity as 31% of those tested with dry eyes have a moderate visual impairment. Conclusion: People with diabetes are at a higher risk of developing dry eye. So diabetic patients should undergo regular ocular examination and must be screened for dry eyes. Early diagnosis and treatment of dry eyes is the best choice to prevent ocular complications in the future

Some observations on light fishing off Thiruvananthapuram coast

The artisanal fisheries of the Thiruvananthapuram coast axe of considerable importance in the fisheries of Kerala State due to their significant contributions to the catch of resources like tunas, anchovies, ribbonfish, caranglds, perches and cephalopods

Lefamulin: novel pleuromutilin drug for community acquired bacterial pneumonia

The advent and spread of antimicrobial resistance has led to a global public health emergency necessitating development of new antimicrobial drugs. Community acquired bacterial pneumonia (CABP) contributes a major portion of societal burden with increasing morbidity due to evolution of drug resistant strains. Lefamulin is a novel pleuromutilin antibiotic with unique mechanism of action through inhibition of protein synthesis by binding to the peptidyl transferase center of the 50s bacterial ribosome. The drug displays activity against Gram positive and atypical organisms associated with CABP (i.e., Streptococcus pneumoniae, Haemophilus influenzae, Mycoplasma pneumonia, Legionella pneumophila, and Chlamydophila pneumoniae), with an expanded Gram-positive spectrum including Staphylococcus aureus (i.e., methicillin-resistant, vancomycin-intermediate, and heterogeneous strains). Lefamulin is available in both intravenous (IV) and per oral (PO) formulation, exhibits high nonlinear plasma protein binding with low unbound concentrations, higher concentrations in lung epithelial lining fluid (ELF) than in plasma, and a half-life of approximately 10 hour. The recommended IV dose is 150 mg twice daily over 1 hour or a PO dose of 600 mg twice daily. Most common adverse drug reactions injection site reactions, hepatic enzyme elevation, nausea, diarrhoea, hypokalemia, insomnia, and headache. Clinical trials for lefamulin have been positive and Phase 3 data suggest similar efficacy when compared to moxifloxacin with or without linezolid in CABP. Also, the documented resistance and cross-resistance with other Gram-positive antibacterials remains low. With Nabrivia Pharmaceuticals having already received US FDA approval in August 2019, lefamulin may soon be a new addition to the mounting armoury of drugs against CABP.

Lattice guiding for sputter deposition of single domain (Sr0.6Ba0.4)Nb2O6 ferroelectric thin films

Lattice guiding is used to synthesize preferentially oriented thin films of (Sr0.6Ba0.4)Nb2O6 by RF magnetron sputtering, with the film-substrate crystallographic relationship determined. These ferroelectric thin films guide light at 532 and 633 nm and have a single domain structure that can be written with permanent, submicron, anti-parallel domains

Type and timing of heralding in ST-elevation and non-ST-elevation myocardial infarction: an analysis of prospectively collected electronic healthcare records linked to the national registry of acute coronary syndromes.

AIMS: It is widely thought that ST-elevation myocardial infarction (STEMI) is more likely to occur without warning (i.e. an unanticipated event in a previously healthy person) than non-ST-elevation myocardial infarction (NSTEMI), but no large study has evaluated this using prospectively collected data. The aim of this study was to compare the evolution of atherosclerotic disease and cardiovascular risk between people going on to experience STEMI and NSTEMI. METHODS: We identified patients experiencing STEMI and NSTEMI in the national registry of myocardial infarction for England and Wales (Myocardial Ischaemia National Audit Project), for whom linked primary care records were available in the General Practice Research Database (as part of the CALIBER collaboration). We compared the prevalence and timing of atherosclerotic disease and major cardiovascular risk factors including smoking, hypertension, diabetes, and dyslipidaemia, between patients later experiencing STEMI to those experiencing NSTEMI. RESULTS: A total of 8174 myocardial infarction patients were included (3780 STEMI, 4394 NSTEMI). Myocardial infarction without heralding by previously diagnosed atherosclerotic disease occurred in 71% STEMI (95% CI 69-72%) and 50% NSTEMI patients (95% CI 48-51%). The proportions of myocardial infarctions with no prior atherosclerotic disease, major risk factors, or chest pain was 14% (95% CI 13-16%) in STEMI and 9% (95% CI 9-10%) in NSTEMI. The rate of heralding coronary diagnoses was particularly high in the 12 months before infarct; 4.1-times higher (95% CI 3.3-5.0) in STEMI and 3.6-times higher (95% CI 3.1-4.2) in NSTEMI compared to the rate in earlier years. CONCLUSIONS: Acute myocardial infarction occurring without prior diagnosed coronary, cerebrovascular, or peripheral arterial disease was common, especially for STEMI. However, there was a high prevalence of risk factors or symptoms in patients without previously diagnosed disease. Better understanding of the antecedents in the year before myocardial infarction is required

Association of Relative Age in the School Year With Diagnosis of Intellectual Disability, Attention-Deficit/Hyperactivity Disorder, and Depression

IMPORTANCE: Young relative age within the school year has previously been associated with attention-deficit/hyperactivity disorder (ADHD) diagnosis and, based on limited evidence, diagnosis of intellectual disability. No study to date has examined the association between relative age and diagnosis of depression. OBJECTIVE: To estimate the associations with intellectual disability and ADHD and investigate a potential novel association between relative age and childhood depression. DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort study of 1 042 106 children aged 4 to 15 years used electronic record data collected before January 3, 2017, from more than 700 general practices contributing to the UK Clinical Practice Research Datalink. Multivariable Cox proportional hazards regression modeling was used to explore the association between relative age and the incidence of intellectual disability, ADHD, and depression before age 16 years. Data were analyzed between July 2017 and January 2019. EXPOSURES: Relative age within school year determined by month of birth and categorized into four 3-month groups. MAIN OUTCOMES AND MEASURES: Intellectual disability, ADHD, and depression. RESULTS: In the total cohort of 1 042 106 children, 532 876 were male (51.1%) and the median age at study entry was 4.0 years (interquartile range, 4.0-5.0). There was evidence that being born in the last quarter of the school year (ie, being the youngest group in a school year) was associated with diagnosis of intellectual disability (adjusted hazard ratio [aHR], 1.30; 95% CI, 1.18-1.42), ADHD (aHR, 1.36; 95% CI, 1.28-1.45), and depression (aHR, 1.31; 95% CI, 1.08-1.59) compared with being born in the first quarter. A graded association was seen with intermediate age groups at a smaller increased risk of each diagnosis compared with the oldest group, with aHRs for intellectual disability for those born in the second quarter of 1.06 (95% CI, 0.96-1.17) and for those born in the third quarter of 1.20 (95% CI, 1.09-1.32); aHRs for ADHD for those born in the second quarter of 1.15 (95% CI, 1.08-1.23) and for those born in the third quarter of 1.31 (95% CI, 1.23-1.40); and aHRs for depression for those born in the second quarter of 1.05 (95% CI, 0.85-1.29) and for those born in the third quarter of 1.13 (95% CI, 0.92-1.38). CONCLUSIONS AND RELEVANCE: In this study, relative youth status in the school year is associated with an increased risk of diagnosis of ADHD, intellectual disability, and depression in childhood. Further research into clinical and policy interventions to minimize these associations appears to be needed

Effect of β blockers on mortality after myocardial infarction in adults with COPD: Population based cohort study of UK electronic healthcare records

Objectives: To investigate whether the use and timing of prescription of β blockers in patients with chronic obstructive pulmonary disease (COPD) having a first myocardial infarction was associated with survival and to identify factors related to their use. Design: Population based cohort study in England. Setting: UK national registry of myocardial infarction (Myocardial Ischaemia National Audit Project (MINAP)) linked to the General Practice Research Database (GPRD), 2003-11. Participants: Patients with COPD with a first myocardial infarction in 1 January 2003 to 31 December 2008 as recorded in MINAP, who had no previous evidence of myocardial infarction in their GPRD or MINAP record. Data were provided by the Cardiovascular Disease Research using Linked Bespoke studies and Electronic Health Records (CALIBER) group at University College London. Main outcome measure: Cox proportional hazards ratio for mortality after myocardial infarction in patients with COPD in those prescribed β blockers or not, corrected for covariates including age, sex, smoking status, drugs, comorbidities, type of myocardial infarction, and severity of infarct. Results: Among 1063 patients with COPD, treatment with β blockers started during the hospital admission for myocardial infarction was associated with substantial survival benefits (fully adjusted hazard ratio 0.50, 95% confidence interval 0.36 to 0.69; P<0.001; median follow-up time 2.9 years). Patients already taking a β blocker before their myocardial infarction also had a survival benefit (0.59, 0.44 to 0.79; P<0.001). Similar results were obtained with propensity scores as an alternative method to adjust for differences between those prescribed and not prescribed β blockers. With follow-up started from date of discharge from hospital, the effect size was slightly attenuated but there was a similar protective effect of treatment with β blockers started during hospital admission for myocardial infarction (0.64, 0.44 to 0.94; P=0.02). Conclusions: The use of β blockers started either at the time of hospital admission for myocardial infarction or before a myocardial infarction is associated with improved survival after myocardial infarction in patients with COPD. Registration: NCT01335672