3,460 research outputs found

    Enhanced overall efficiency of GaInN-based light-emitting diodes with reduced efficiency droop by Al-composition-graded AlGaN/GaN superlattice electron blocking layer

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    AlxGa1-xN/GaN superlattice electron blocking layers (EBLs) with gradually decreasing Al composition toward the p-type GaN layer are introduced to GaInN-based high-power light-emitting diodes (LEDs). GaInN/GaN multiple quantum well LEDs with 5- and 9-period Al-composition-graded AlxGa1-xN/GaN EBL show comparable operating voltage, higher efficiency as well as less efficiency droop than LEDs having conventional bulk AlGaN EBL, which is attributed to the superlattice doping effect, enhanced hole injection into the active region, and reduced potential drop in the EBL by grading Al compositions. Simulation results reveal a reduction in electron leakage for the superlattice EBL, in agreement with experimental results. (C) 2013 AIP Publishing LLC.open1133sciescopu

    Tension pneumopericardium after removal of pericardiocentesis drainage catheter

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    This image showed tension pneumopericardium caused by removing the pericardiocentesis catheter, which was inserted to drain malignant pericardial effusion. Tension pneumopericardium is a rare and potentially fatal event. Mortality from tension pneumopericardium can be as high as 50%. Therefore, it is important to suspect and detect early, if the patient complained of dyspnea after removing the pericardiocentesis drainage cathete

    Anti-diabetic effect of Cyclo-His-Pro (CHP)-enriched yeast hydrolysate in streptozotocin-induced diabetic mice

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    The present study was designed to investigate the hypoglycemic effects of the daily oral dose of 0.50 to 0.75 g/kg of yeast hydrolysate (YH) containing high Cyclo-His-Pro (51.0 mg CHP/g YH) on normal and streptozotocin (STZ)-induced diabetic rats for 14 days. In STZ-induced diabetic rats, after administrations of the YH for 14 days, the body weight gain was significantly increased in dose dependent manner, and the plasma glucose levels were decreased approximately (60%) as compared to the STZ induced diabetic control group. Glucose level showed significant differences between the diabetic control (DC) and the YH administered groups in oral glucose tolerance test (OGTT) (P<0.05). Results of the OGTT showed a significant decrease in the area under curve (AUC) value of YH supplemented groups as compared to the DC group. The present data suggests that the CHP-enriched YH has potential anti-diabetic effect, which can help in the cure and management of diabetes.Keywords: Yeast hydrolysate, Cyclo-His-Pro (CHP), diabetes, streptozotocin.African Journal of Biotechnology Vol. 12(35), pp. 5473-547

    Antimicrobial peptide from Bacillus subtilis CSB138: characterization, killing kinetics, and synergistic potency

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    We studied the prospect of synergy between the antimicrobial peptide p138c and non-peptide antibiotics for increasing the potency and bacterial killing kinetics of these agents. The production of p138c was maximized in the late exponential growth phase of Bacillus subtilis CSB138. Purification of p138c resulted in a total of 4800 arbitrary units (AU) with 19.15-fold and 3.2% recovery. Peptide p138c was thermo-tolerant up to 50 °C and stable at pH 5.8 to 11. The biochemical nature of p138c was determined by a bioassay, similar to tricine-SDS-PAGE, indicating inhibition at 3 kDa. The amino acid sequence of p138c was Gly-Leu-Glu-Glu-Thr-Val-Tyr-Ile-Tyr-Gly-Ala-Asn-Met-X-Ser. Potency and killing kinetics against vancomycin-resistant Staphylococcus aureus improved considerably when p138c was synergized with oxacillin, ampicillin, and penicillin G. The minimal inhibitory concentration (MIC) of p138c showed a 4-, 8-, and 16-fold improvement when p138c was combined with oxacillin, ampicillin, and penicillin G, respectively. The fractional inhibitory concentration index for the combination of p138c and oxacillin, ampicillin, and penicillin G was 0.3125, 0.25, and 0.09, respectively. Synergy with non-peptide antibiotics resulted in enhanced killing kinetics of p138c. Hence, the synergy between antimicrobial peptide and non-peptide antibiotics may enhance the potency and bacterial killing kinetics, providing more potent and rapidly acting agents for therapeutic use. [Int Microbiol 20(1):43-53 (2017)]Keywords: Bacillus subtilis · antimicrobial peptides · killing kinetic

    Treatment of Spontaneous Cervical Spinal Subdural Hematoma with Methylprednisolone Pulse Therapy

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    We report herein a case of hyperacute onset of spontaneous cervical spinal subdural hematoma treated with methylprednisolone pulse therapy that showed good results. A 57-year-old man was admitted for posterior neck pain and paraparesis which occurred an hour ago. MRI revealed a ventral subdural hematoma distributed from the level of C1 down to T3, compressing the spinal cord. Conservative management with methylprednisolone pulse therapy was administered considering the patient's poor general condition. Although emergent surgical decompression is necessary in most cases of spinal subdural hematoma, conservative management with steroid therapy could be effective

    Microstructure and Mechanical Properties of High-Entropy Alloy Co20Cr26Fe20Mn20Ni14 Processed by High-Pressure Torsion at 77 K and 300 K

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    In this work, the mechanical characteristics of high-entropy alloy Co20Cr26Fe20Mn20Ni14 with low-stacking fault energy processed by cryogenic and room temperature high-pressure torsion (HPT) were studied. X-ray diffraction, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analyses were performed to identify the phase and microstructure variation and the mechanical properties characterized by Vickers hardness measurements and tensile testing. Cryogenic HPT was found to result in a lower mechanical strength of alloy Co20Cr26Fe20Mn20Ni14 than room temperature HPT. Microstructure analysis by SEM and TEM was conducted to shed light on the microstructural changes in the alloy Co20Cr26Fe20Mn20Ni14 caused by HPT processing. Electron microscopy data provided evidence of a deformation-induced phase transformation in the alloy processed by cryogenic HPT. Unusual softening phenomena induced by cryogenic HPT were characterized by analyzing the dislocation density as determined from X-Ray diffraction peak broadening.11Ysciescopu

    Causes and effects of 2008 financial crisis

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    Beginning in the mid 2007’s the US financial market started to slide into the “worst financial crisis since the Great Depression of the early 1930’s” (Thakor, 2015: p.156). The domino effect of several events and occasions were leading first to a countrywide recession in the USA then later spreading globally. In the following this term paper will deal with the main causes and effects of 2008 financial crisis. Unlike other topics in literature there is no consensus about the question of guilt in this sense. Among economists there are different approaches to explain the main causes of the financial crisis
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