Anomalous Thermoelectric power of over-doped Bi2Sr2CaCu2O8 superconductor

Temperature dependence of thermoelectric power S(T) of three differently processed Bi2Sr2CaCu2O8 (Bi2212) samples, viz. as-processed melt quenched (Bi2212-MQ), 6000C N2-annealed (Bi2212-N2) and 6000C O2-annealed (Bi2212-O2) is reported here. All the samples possess single-phase character and their superconducting transition temperatures (TcR=0) are 85 K, 90 K and 72 K respectively for Bi2212-MQ, Bi2212-N2 and Bi2212-O2. While Bi2212-MQ and Bi2212-N2 samples are in near optimum doping regime, Bi2212-O2 is an over-doped sample. TcS=0 values obtained through S(T) data are also in line with those deduced from the temperature dependence of resistance and DC magnetization. Interestingly, S(T) behaviour of the optimally-doped Bi2212-MQ and Bi2212-N2 samples is seen to be positive in whole temperature range, it is found negative for the over-doped Bi2212-O2 sample above TcS=0. These results have been seen in the light of the recent band structure calculations and the ensuing split Fermi surface as determined by angle-resolved photoelectron spectroscopy (ARPES).Comment: 11 Pages Text + Figs: comments welcome ([email protected]

Breast Feeding Practices In Rural And Urban Communities In A Hilly District Of North India

Research question: What are the breast feeding practices in urban and rural communities of a hilly district? Objectives: 1. To study breast feeding practices. 2. To find out the influence of motherâ€s education on these practices. Study Design: Cross-sectional Setting: Urban and Rural Participants: Mothers of under 3 years children Sample size: 994 subjects(489 from urban and 505 from rural areas) Study variables: Prelacteal feed, initiation of breast feeding, complimentary feed introduction, continued breast feeding, material literacy, urban and rural subjects. Statistical analysis: Proportions and chi-square test. Results: A high exclusive breast feeding rate was observed which was 0.74 in urban and 0.72 in rural children less than 4 months of age. Timely complementary feeding rate was 0.84 and 0.70 in urban and rural areas respectively. Continued breast feeding rates at 1 and 2 years were 0.44 to 0.65 and 0.15 to 0.36 in urban and rural areas respectively

A classic case of tuberous sclerosis with multisystem involvement including giant bilateral renal angiomyolipomas presenting as massive hematuria

BACKGROUND: Tuberous Sclerosis (TSC) also known as Bourneville disease is a neurocutaneous syndrome having an autosomal dominant inheritance pattern, though the condition has a high rate of spontaneous mutation. It is the second most common neurocutaneous syndrome after neurofibromatosis. This disease demonstrates a widespread potential for hamartomatous growths in multiple organ systems. CASE REPORT: We report a case of a 36-year-old female with TSC presenting as massive hematuria with underlying giant bilateral renal angiomyolipomas (AML) with estimated total tumor burden of more than 8 kg which is to the best of our knowledge the highest ever reported. The patient also had lymphangioleiomyomatosis and lesions in the brain, skin, teeth and bones. CONCLUSIONS: TSC has a wide variety of clinical and radiologic manifestations. It should be suspected when some of the common radiological manifestations are found, including CNS involvement, renal and hepatic AMLs and LAM, even if clinical signs are not obvious. Renal AMLs in setting of TSC may reach giant proportions and may present with massive hematuria

Negative thermoelectric power of over-doped Bi2Sr2CaCu2O8 superconductor

The thermoelectric power S(T) studies of Bi2Sr2CaCu2O8 (Bi2212) samples, including as-processed Partially Melted (Bi2212-PM) and 800 °C O2-annealed (Bi2212-O2) are reported here. While Bi2212-PM sample is near optimum doping regime, Bi2212-O2 is an over-doped sample. View the MathML source values obtained through S(T) data match very well with those deduced from the R(T). Interestingly, S(T) behavior of the optimally-doped Bi2212-PM sample is seen to be positive in whole temperature range, it is found negative for the over-doped Bi2212-O2 sample above View the MathML source. The observed negative S(T) dependence of the over-doped Bi2212-O2 is in accord with the recent band structure calculations and is in line with the theoretical investigations on a van Hove singularity in electronic density of states in HTSc compounds