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排序方式: 共有194条查询结果,搜索用时 15 毫秒
31.
Adam R. Brandt Yuchi Sun Sharad Bharadwaj David Livingston Eugene Tan Deborah Gordon 《PloS one》2015,10(12)
Studies of the energy return on investment (EROI) for oil production generally rely on aggregated statistics for large regions or countries. In order to better understand the drivers of the energy productivity of oil production, we use a novel approach that applies a detailed field-level engineering model of oil and gas production to estimate energy requirements of drilling, producing, processing, and transporting crude oil. We examine 40 global oilfields, utilizing detailed data for each field from hundreds of technical and scientific data sources. Resulting net energy return (NER) ratios for studied oil fields range from ≈2 to ≈100 MJ crude oil produced per MJ of total fuels consumed. External energy return (EER) ratios, which compare energy produced to energy consumed from external sources, exceed 1000:1 for fields that are largely self-sufficient. The lowest energy returns are found to come from thermally-enhanced oil recovery technologies. Results are generally insensitive to reasonable ranges of assumptions explored in sensitivity analysis. Fields with very large associated gas production are sensitive to assumptions about surface fluids processing due to the shifts in energy consumed under different gas treatment configurations. This model does not currently include energy invested in building oilfield capital equipment (e.g., drilling rigs), nor does it include other indirect energy uses such as labor or services. 相似文献
32.
G. Gopinath A. K. Mahapatra J. C. Bharadwaj R. Banerji D. N. Sharma P. N. Tandon 《Journal of biosciences》1989,14(3):255-260
A feasibility study of neural transplantation in adult rhesus monkey was undertaken. Fresh and preserved neocortex containing
multiplying and maturing neurons obtained from 55–70 gestation days were transplanted into the striatum, cerebellum and cerebral
cortex of adult monkeys. Tissues were preserved for 4 days either at subzero temperature in the freezer compartment of the
ordinary refrigerator in Ringer lactate or incubated in culture medium. While 2 monkeys out of 5 injected with preserved tissue
had successful transplants after 4 months, all the 10 monkeys injected with fresh tissue had no transplants. The size of the
two surviving transplants was small. The neurons in the transplants were mainly in clusters. Many of the cells were immature
and some showed early degenerative changes. Neuronal processes were restricted to the transplants and thus showed lack of
morphological integration with the host tissue. Further studies are in progress to define the nature of the embryonic tissue
of primate which can grow and survive and also the role of neural grafts in functional recovery following experimental lesions
of the brain regions. 相似文献
33.
Pranay Bharadwaj Christine McInnis Amanda M. K. Madden Paul J. Bonthuis Susan Zup Emilie F. Rissman Jin Ho Park 《PloS one》2013,8(7)
Male sexual behavior (MSB) is modulated by gonadal steroids, yet this relationship is highly variable across species and between individuals. A significant percentage (∼30%) of B6D2F1 hybrid male mice demonstrate MSB after long-term orchidectomy (herein after referred to as “maters”), providing an opportunity to examine the mechanisms that underlie individual differences in steroidal regulation of MSB. Use of gene expression arrays comparing maters and non-maters has provided a first pass look at the genetic underpinnings of steroid-independent MSB. Surprisingly, of the ∼500 genes in the medial preoptic area (MPOA) that differed between maters and non-maters, no steroid hormone or receptor genes were differentially expressed between the two groups. Interestingly, best known for their association with Alzheimer’s disease, amyloid precursor protein (APP) and the microtubule-associated protein tau (MAPT) were elevated in maters. Increased levels of their protein products (APP and tau) in their non-pathological states have been implicated in cell survival, neuroprotection, and supporting synaptic integrity. Here we tested transgenic mice that overexpress tau and found facilitated mounting and intromission behavior after long-term orchidectomy relative to littermate controls. In addition, levels of synaptophysin and spinophilin, proteins generally enriched in synapses and dendritic spines respectively, were elevated in the MPOA of maters. Dendritic morphology was also assessed in Golgi-impregnated brains of orchidectomized B6D2F1 males, and hybrid maters exhibited greater dendritic spine density in MPOA neurons. In sum, we show for the first time that retention of MSB in the absence of steroids is correlated with morphological differences in neurons. 相似文献
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The diagnosis, angiographic evaluation and surgical treatment by aortocoronary vein bypass are described in a 3½-year-old girl with anomalous origin of the left coronary artery from the pulmonary artery. The anomaly had resulted in cardiac dilatation, diminished left ventricular contractility, an aneurysm of the left ventricular free wall and mitral regurgitation.At the postoperative cardiac catheterization the graft was demonstrated to be patent, but a significant proportion of the flow to the left coronary artery was derived from anastomotic connections with the right coronary artery. The most striking evidence of improvement was obtained from the left ventricular volume studies which showed that the end systoiic volume had decreased from 85 to 49 ml./m.2 with an increase in ejection fraction from 0.39 to 0.62, suggesting enhanced left ventricular contractility after surgery.The patient continues to do well and is free from symptoms. 相似文献
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A copper(II) coordination polymer {[Cu2(cpa)2]}n (1) (cpaH2 = 4-carboxyphenoxyacetic acid) has been synthesized by hydrothermal technique. The X-ray structure of the compound shows that it is a 2D coordination polymer where Cu(II) ions are pentacoordinated in a square pyramidal fashion. The magnetic measurement of 1 in different magnetic fields suggest a weak ferromagnetic ordering taking place below 20 K, arising from spin canting phenomenon due to the non-coplanar basal planes of copper ions. 相似文献
40.
Anitha Moorthy Amita Gupta Ramesh Bhosale Srikanth Tripathy Jayagowri Sastry Smita Kulkarni Madhuri Thakar Renu Bharadwaj Anju Kagal Arvind V. Bhore Sandesh Patil Vandana Kulkarni Varadharajan Venkataramani Usha Balasubramaniam Nishi Suryavanshi Carrie Ziemniak Nikhil Gupte Robert Bollinger Deborah Persaud for the India SWEN Study Team 《PloS one》2009,4(1)