Effect of Synthesis methods on the Properties of Magnetic Material

Ba1-xPbxFe12O19 composition (x=0.0 to 1.0) synthesized by Co-precipitation and Sol-Gel methods. In Coprecipitation method BaCO3, PbO and Fe (NO3)3 .9H2O were used as basic ingredients. Acids and Di-H2O were used as solvents. Molar ratio of cations was 12. pH of solution kept constant at 13. All samples sintered at 965±5oC for three hours. Lead own properties, synthesis at room temperature and substitution in R-block of structure were the reasons for decrease of phase purity from ?x? =0.0 to 70% for ?x?=1.0. Decrease in phase purity and heterogeneity of material caused the properties to decrease. In Sol gel method, Nitrates (salts) and Ethylene glycol (liquid) were the basic material used. The mixed solutions dried out on a hot plate whose temperature was maintained constant at 200±2oC. Pellets formed by applying suitable hydraulic pressure and then sintered at same temperature written above i.e. 965±5oC for three hours. 100% phase purity achieved. All properties modified. Temperature and frequency dependent electrical properties investigated and reported here. DC and AC obtained properties were useful for different electronics and computer devices like capacitors, smart storage devices and multilayer chip inductors. Overall, both these properties improved through solgelmethod as compared to co-precipitation method. It was because of improvement in phase purity and change inmorphology of synthesized material

Clinical and echocardiographic characteristics of patients with significant pericardial effusion requiring pericardiocentesis

Objective: Clinical and echocardiographic features of significant pericardial effusion (PE) have been reported from the west. Currently there is lack of published data from this part of the world, we reviewed all consecutive cases of significant PE requiring echocardiographic assisted pericardiocentesis to analyze the clinical and echocardiographic features of these patients.Methods: Forty four consecutive patients who underwent echocardiography assisted pericardiocentesis at the Aga Khan University Hospital (AKUH) between January 1988 and May 2001 re included in this review.Results: Most common presenting symptoms were dyspnea (89%) and fever (36%). Elevated JVP and pulsus paradoxus were documented in 59% and 41% of patients respectively. Sinus tachycardia (75%) and low voltage (34%) were the most common ECG findings. Malignancy (45-51%) and tuberculosis (27%) were among the most frequent causes of PE. One patient died during echocardiography-assisted pericardiocentesis.CONCLUSION: The symptoms and physical findings of haemodynamically significant PE are frequently nonspecific. Transthoracic echocardiography is the gold standard for rapid and confirmatory diagnosis of PE and cardiac tamponade. The most common cause of PE was malignancy followed by tuberculosis. Pericardiocentesis under echocardiographic guidance is a safe and effective treatment for significant PE

Genome-wide analysis of blood lipid metabolites in over 5000 South Asians reveals biological insights at cardiometabolic disease loci.

Funder: PfizerFunder: NovartisFunder: National Institute for Health ResearchFunder: MerckBackgroundGenetic, lifestyle, and environmental factors can lead to perturbations in circulating lipid levels and increase the risk of cardiovascular and metabolic diseases. However, how changes in individual lipid species contribute to disease risk is often unclear. Moreover, little is known about the role of lipids on cardiovascular disease in Pakistan, a population historically underrepresented in cardiovascular studies.MethodsWe characterised the genetic architecture of the human blood lipidome in 5662 hospital controls from the Pakistan Risk of Myocardial Infarction Study (PROMIS) and 13,814 healthy British blood donors from the INTERVAL study. We applied a candidate causal gene prioritisation tool to link the genetic variants associated with each lipid to the most likely causal genes, and Gaussian Graphical Modelling network analysis to identify and illustrate relationships between lipids and genetic loci.ResultsWe identified 253 genetic associations with 181 lipids measured using direct infusion high-resolution mass spectrometry in PROMIS, and 502 genetic associations with 244 lipids in INTERVAL. Our analyses revealed new biological insights at genetic loci associated with cardiometabolic diseases, including novel lipid associations at the LPL, MBOAT7, LIPC, APOE-C1-C2-C4, SGPP1, and SPTLC3 loci.ConclusionsOur findings, generated using a distinctive lipidomics platform in an understudied South Asian population, strengthen and expand the knowledge base of the genetic determinants of lipids and their association with cardiometabolic disease-related loci

An Unbiased Lipid Phenotyping Approach To Study the Genetic Determinants of Lipids and Their Association with Coronary Heart Disease Risk Factors.

Direct infusion high-resolution mass spectrometry (DIHRMS) is a novel, high-throughput approach to rapidly and accurately profile hundreds of lipids in human serum without prior chromatography, facilitating in-depth lipid phenotyping for large epidemiological studies to reveal the detailed associations of individual lipids with coronary heart disease (CHD) risk factors. Intact lipid profiling by DIHRMS was performed on 5662 serum samples from healthy participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS). We developed a novel semi-targeted peak-picking algorithm to detect mass-to-charge ratios in positive and negative ionization modes. We analyzed lipid partial correlations, assessed the association of lipid principal components with established CHD risk factors and genetic variants, and examined differences between lipids for a common genetic polymorphism. The DIHRMS method provided information on 360 lipids (including fatty acyls, glycerolipids, glycerophospholipids, sphingolipids, and sterol lipids), with a median coefficient of variation of 11.6% (range: 5.4-51.9). The lipids were highly correlated and exhibited a range of associations with clinical chemistry biomarkers and lifestyle factors. This platform can provide many novel insights into the effects of physiology and lifestyle on lipid metabolism, genetic determinants of lipids, and the relationship between individual lipids and CHD risk factors

Human knockouts and phenotypic analysis in a cohort with a high rate of consanguinity

A major goal of biomedicine is to understand the function of every gene in the human genome. Loss-of-function mutations can disrupt both copies of a given gene in humans and phenotypic analysis of such 'human knockouts' can provide insight into gene function. Consanguineous unions are more likely to result in offspring carrying homozygous loss-of-function mutations. In Pakistan, consanguinity rates are notably high. Here we sequence the protein-coding regions of 10,503 adult participants in the Pakistan Risk of Myocardial Infarction Study (PROMIS), designed to understand the determinants of cardiometabolic diseases in individuals from South Asia. We identified individuals carrying homozygous predicted loss-of-function (pLoF) mutations, and performed phenotypic analysis involving more than 200 biochemical and disease traits. We enumerated 49,138 rare (<1% minor allele frequency) pLoF mutations. These pLoF mutations are estimated to knock out 1,317 genes, each in at least one participant. Homozygosity for pLoF mutations at PLA2G7 was associated with absent enzymatic activity of soluble lipoprotein-associated phospholipase A2; at CYP2F1, with higher plasma interleukin-8 concentrations; at TREH, with lower concentrations of apoB-containing lipoprotein subfractions; at either A3GALT2 or NRG4, with markedly reduced plasma insulin C-peptide concentrations; and at SLC9A3R1, with mediators of calcium and phosphate signalling. Heterozygous deficiency of APOC3 has been shown to protect against coronary heart disease; we identified APOC3 homozygous pLoF carriers in our cohort. We recruited these human knockouts and challenged them with an oral fat load. Compared with family members lacking the mutation, individuals with APOC3 knocked out displayed marked blunting of the usual post-prandial rise in plasma triglycerides. Overall, these observations provide a roadmap for a 'human knockout project', a systematic effort to understand the phenotypic consequences of complete disruption of genes in humans.D.S. is supported by grants from the National Institutes of Health, the Fogarty International, the Wellcome Trust, the British Heart Foundation, and Pfizer. P.N. is supported by the John S. LaDue Memorial Fellowship in Cardiology from Harvard Medical School. H.-H.W. is supported by a grant from the Samsung Medical Center, Korea (SMO116163). S.K. is supported by the Ofer and Shelly Nemirovsky MGH Research Scholar Award and by grants from the National Institutes of Health (R01HL107816), the Donovan Family Foundation, and Fondation Leducq. Exome sequencing was supported by a grant from the NHGRI (5U54HG003067-11) to S.G. and E.S.L. D.G.M. is supported by a grant from the National Institutes of Health (R01GM104371). J.D. holds a British Heart Foundation Chair, European Research Council Senior Investigator Award, and NIHR Senior Investigator Award. The Cardiovascular Epidemiology Unit at the University of Cambridge, which supported the field work and genotyping of PROMIS, is funded by the UK Medical Research Council, British Heart Foundation, and NIHR Cambridge Biomedical Research Centre ... Fieldwork in the PROMIS study has been supported through funds available to investigators at the Center for Non-Communicable Diseases, Pakistan and the University of Cambridge, UK

Thermoelectric properties in multifaceted Bi/lithium cobaltate composites

Thermoelectricity is one of the most appealing way to convert waste heat into electrical energy. Lithium cobaltate was synthesized without water and surfactants (WOWS) by sol–gel method. Composites of phase pure lithium cobaltate were prepared with different weight percent (5%, 10%, 15%) of bismuth. Structural analysis was done by using X-ray diffraction (XRD) technique. XRD of all samples confirmed the rhombohedral structure. Crystallite size of as-prepared sample was found in the range of 10–27&nbsp;nm and that of sintered composites was found in the range of 29–47&nbsp;nm. DC electrical properties as a function of temperature was measured by using four-probe method, in the temperature range of 300–413&nbsp;K. Thermal transport properties of all samples were done by using advantageous transient plane source method. Thermal conductivity, thermal diffusivity, and volumetric heat capacity were measured as a function of temperature in the temperature range of 300–413&nbsp;K. As expected, it was observed that thermal conductivity of composites with 15% Bi i.e., 1.0866&nbsp;W/m&nbsp;K at 413&nbsp;K was very much less than that of lithium cobaltate. Seebeck coefficient was measured as a function of temperature and these were also in line with the electrical and thermal transport data. Variation in Seebeck coefficient is observed both with respect to temperature and the maximum value is obtained with 5% bismuth i.e., 703.89&nbsp;μV/K

Study of annealing effects on the physical properties of evaporated SnS thin films for photovoltaic applications

Tin Sulphide (SnS) thin films have been deposited on glass slides by thermal evaporation using SnS powder. The improvements in the structural and optical properties of SnS thin films on annealing at different temperatures (200 degrees C, 300 degrees C, 400 degrees C, and 500 degrees C) in vacuum for one hour are presented in this work. The thin films annealed at 500 degrees C were decomposed, which limits the annealing temperature below than 500 degrees C. X-ray diffraction characterization showed an intensive peak at 31.8 degrees originating from (111) reflection. Ellipsometry measurements were done for optical studies and optical absorption coefficient for as-deposited films was 2.02 x 10(4) increased to 4.90 x 10(4) (cm)(-1) for films annealed to 300 degrees C for incident photon energies 1.55eV, and direct band gap of 1.90 eV was indicated

Thermal Conductivity of Ceramic Fibres at High-temperatures

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Enhancement of conductivity in phase pure and doped ceria for fuel cell applications

Solid oxide fuel cells (SOFCs) have gained much attention because of their many advantages including high efficiency and an environmentally friendly nature. Flexibility in fuel choice for both small power units and large-scale power plants is another plus. The main component determining the performance of fuel cells is the electrolyte material. For the electrolyte application, lower-valency cation-doped CeO2 materials have attracted tremendous research interest in SOFCs operating in the intermediate temperature range (500–700°C). Ce0.75−xBixGd0.25O2 (x = 0.0, 0.05, 0.10) was prepared by a sol-gel method in which bismuth was added as a dopant. The material was sintered at 550°C for 2 h. To analyze the structural properties of the sample, x-ray diffraction (XRD) technique was used, which confirmed the cubic fluorite structure. A precision component analyzer was used for dielectric study of the samples in the frequency range of 20&nbsp;Hz to 3&nbsp;MHz at different temperatures (30–400°C). DC resistance was measured using a two-probe method that showed a decreasing trend with increasing temperature. The doped samples demonstrated highly improved structural and electrical properties as compared to those of the undoped sample. The increased conductivity and improved stability of the samples make them a potential candidate for the electrolytes of SOFCs