Finite temperature calculations for the bulk properties of strange star using a many-body approach

We have considered a hot strange star matter, just after the collapse of a supernova, as a composition of strange, up and down quarks to calculate the bulk properties of this system at finite temperature with the density dependent bag constant. To parameterize the density dependent bag constant, we use our results for the lowest order constrained variational (LOCV) calculations of asymmetric nuclear matter. Our calculations for the structure properties of the strange star at different temperatures indicate that its maximum mass decreases by increasing the temperature. We have also compared our results with those of a fixed value of the bag constant. It can be seen that the density dependent bag constant leads to higher values of the maximum mass and radius for the strange star.Comment: 21 pages, 2 tables, 12 figures Astrophys. (2011) accepte

Quasimonoenergetic electron beam generation by using a pinholelike collimator in a self-modulated laser wakefield acceleration

A relativistic electron bunch with a large charge (>2 nC) was produced from a self-modulated laser wakefield acceleration configuration. For this experiment, an intense laser beam with a peak power of 2 TW and a duration of 700 fs was focused in a supersonic He gas jet, and relativistic high-energy electrons were observed from the strong laser-plasma interaction. By passing the electron bunch through a small pinholelike collimator, we could generate a quasimonoenergetic high-energy electron beam, in which electrons within a cone angle of 0.25 mrad (f/70) were selected. The beam clearly showed a narrow-energy-spread behavior with a central energy of 4.3 MeV and a charge of 200 pC. The acceleration gradient was estimated to be about 30 GeV/m. Particle-in-cell simulations were performed for comparison study and the result shows that both the experimental and simulation results are in good agreement and the electron trapping is initiated by the slow beat wave of the Raman backward wave and the incident laser pulse.open181

Appearance and Dynamics of Helical Flux Tubes under Electron Cyclotron Resonance Heating in the Core of KSTAR Plasmas

Dual (or sometimes multiple) flux tubes (DFTs) have been observed in the core of sawtoothing KSTAR tokamak plasmas with electron cyclotron resonance heating. The time evolution of the flux tubes visualized by a 2D electron cyclotron emission imaging diagnostic typically consists of four distinctive phases: (1) growth of one flux tube out of multiple small flux tubes during the initial buildup period following a sawtooth crash, resulting in a single dominant flux tube along the m/n = 1/1 helical magnetic field lines, (2) sudden rapid growth of another flux tube via a fast heat transfer from the first one, resulting in approximately identical DFTs, (3) coalescence of the two flux tubes into a single m/n = 1/1 flux tube resembling the internal kink mode in the normal sawteeth, which is explained by a model of two currentcarrying wires confined on a flux surface, and (4) fast localized crash of the merged flux tube similar to the standard sawtooth crash. The dynamics of the DFTs implies that the internal kink mode is not a unique prerequisite to the sawtooth crash, providing a new insight on the control of the sawtooth.X112217Ysciescopu

Determining the neurotransmitter concentration profile at active synapses

Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

Contribution of sea-ice loss to Arctic amplification is regulated by Pacific Ocean decadal variability

The pace of Arctic warming is about double that at lower latitudes – a robust phenomenon known as Arctic amplification (AA)1. Many diverse climate processes and feedbacks cause AA2-7, including positive feedbacks associated with diminished sea ice6,7. However, the precise contribution of sea-ice loss to AA remains uncertain7,8. Through analyses of both observations and model simulations, we show that the contribution of sea-ice loss to wintertime AA appears dependent on the phase of the Pacific Decadal Oscillation (PDO). Our results suggest that for the same pattern and amount of sea-ice loss, consequent Arctic warming is larger during the negative PDO phase, relative to the positive phase, leading to larger reductions in the poleward gradient of tropospheric thickness and to more pronounced reductions in the upper-level westerlies. Given the oscillatory nature of the PDO, this relationship has the potential to increase skill in decadal-scale predictability of Arctic and sub-Arctic climate. Our results indicate that Arctic warming in response to the ongoing long-term sea-ice decline9,10 is greater (reduced) during periods of negative (positive) PDO phase. We speculate that the observed recent shift to the positive PDO phase, if maintained and all other factors being equal, could act to temporarily reduce the pace of wintertime Arctic warming in the near future.J.A.S. was funded by a UK Natural Environment Research Council (NERC) grants NE/J019585/1 and NE/M006123/1. J.A.F. was supported by an NSF/ARCSS grant (1304097) and NASA grant (NNX14AH896). The model simulations were performed on the ARCHER UK National Supercomputing Service. We thank the NOAA ESRL and Met Office Hadley Centre for provision of observational and reanalysis data sets. We also thank D. Ackerley for helping to diagnose the cause of model crashes, C. Deser for commenting on the manuscript prior to submission, and two anonymous reviewers for constructive criticism

Smoking and Risk of Kidney Failure in the Singapore Chinese Health Study

Background:The relationship between smoking and risk of kidney failure, especially in people of Chinese origin, is not clear. We analyzed data from the Singapore Chinese Health Study to investigate whether smoking increases the risk of kidney failure.Methods:The Singapore Chinese Health Study is a population-based cohort of 63,257 Chinese adults enrolled between 1993 and 1998. Information on smoking status was collected at baseline. Incidence of kidney failure was identified via record linkage with the nationwide Singapore Renal Registry until 2008. Kidney failure was defined by one of the following: 1) serum creatinine level of more than or equal to 500 μmol/l (5.7 mg/dl), 2) estimated glomerular filtration rate of less than 15 ml/min/1.73 m2, 3) undergoing hemodialysis or peritoneal dialysis, 4) undergone kidney transplantation. Cox proportional hazard regression analysis was performed for the outcome of kidney failure after adjusting for age, education, dialect, herbal medications, body mass index, sex, physician-diagnosed hypertension and diabetes mellitus.Results:The mean age of subjects was 55.6 years at baseline, and 44% were men. Overall 30.6% were ever smokers (current or former) at baseline. A total of 674 incident cases of kidney failure occurred during a median follow-up of 13.3 years. Among men, smokers had a significant increase in the adjusted risk of kidney failure [hazard ratio (HR): 1.29; 95% CI: 1.02-1.64] compared to never smokers. There was a strong dose-dependent association between number of years of smoking and kidney failure, (p for trend = 0.011). The risk decreased with prolonged cessation (quitting ≥10 years since baseline). The number of women smokers was too few for conclusive relationship.Limitation:Information on baseline kidney function was not available.Conclusions:Cigarette smoking is associated with increased risk of kidney failure among Chinese men. The risk appears to be dose- and duration-dependent and modifiable after long duration of cessation. © 2013 Jin et al

National-wide data on the treatment of BPH in Korea

The healthcare system in Korea provides coverage to all the people who are residing in Korea, so the data of the Korea healthcare system are national-wide and relatively accurate. We obtained the recent 5-year data (2004–2008) on the treatment of BPH from the national health insurance system. We tried to determine the trends or changes of BPH treatments in Korea. Over 3.8 million men visited clinics and were prescribed one or more BPH medications, and more than 44 000 men underwent surgical treatment during 2004–2008. Compared with the year 2004, two times the patients were prescribed BPH medications in 2008. With respect to the surgical treatment, the number of cases was increased 1.6 times in 2006 compared with the previous years. The most commonly used surgical option was TURP before 2006, but laser therapy was carried out as much as TURP in 2006 and in the following years. The relative risk of laser therapy in the 50 s is 1.53 (95% CI is 1.47–1.59). In conclusion, our national-wide data for the Korean BPH patients show that these patients' medical treatment increased during the 5 years from 2004 to 2008. Laser treatment had increased and it might replace TURP in several years

Enhanced resistance to bacterial and fungal pathogens by overexpression of a human cathelicidin antimicrobial peptide (hCAP18/LL-37) in Chinese cabbage

The human cathelicidin antimicrobial protein hCAP18, which includes the C-terminal peptide LL-37, is a multifunctional protein. As a possible approach to enhancing the resistance to plant disease, a DNA fragment coding for hCAP18/LL-37 was fused at the C-terminal end of the leader sequence of endopolygalacturonase-inhibiting protein under the control of the cauliflower mosaic virus 35S promoter region. The construct was then introduced into Brassica rapa. LL-37 expression was confirmed in transgenic plants by reverse transcription-polymerase chain reaction and western blot analysis. Transgenic plants exhibited varying levels of resistance to bacterial and fungal pathogens. The average size of disease lesions in the transgenic plants was reduced to less than half of that in wild-type plants. Our results suggest that the antimicrobial LL-37 peptide is involved in wide-spectrum resistance to bacterial and fungal pathogen infection

Modulatory role of phospholipase D in the activation of signal transducer and activator of transcription (STAT)-3 by thyroid oncogenic kinase RET/PTC

<p>Abstract</p> <p>Background</p> <p>RET/PTC (rearranged in transformation/papillary thyroid carcinomas) gene rearrangements are the most frequent genetic alterations identified in papillary thyroid carcinoma. Although it has been established that RET/PTC kinase plays a crucial role in intracellular signaling pathways that regulate cellular transformation, growth, and proliferation in thyroid epithelial cells, the upstream signaling that leads to the activation of RET/PTC is largely unknown. Based on the observation of high levels of PLD expression in human papillary thyroid cancer tissues, we investigated whether PLD plays a role in the regulating the RET/PTC-induced STAT3 activation.</p> <p>Methods</p> <p>Cancer tissue samples were obtained from papillary thyroid cancer patients (n = 6). The expression level of PLD was examined using immunohistochemistry and western blotting. Direct interaction between RET/PTC and PLD was analyzed by co-immunoprecipitation assay. PLD activity was assessed by measuring the formation of [³H]phosphatidylbutanol, the product of PLD-mediated transphosphatidylation, in the presence of <it>n</it>-butanol. The transcriptional activity of STAT3 was assessed by m67 luciferase reporter assay.</p> <p>Results</p> <p>In human papillary thyroid cancer, the expression levels of PLD2 protein were higher than those in the corresponding paired normal tissues. PLD and RET/PTC could be co-immunoprecipitated from cells where each protein was over-expressed. In addition, the activation of PLD by pervanadate triggered phosphorylation of tyrosine 705 residue on STAT-3, and its phosphorylation was dramatically higher in TPC-1 cells (from papillary carcinoma) that have an endogenous RET/PTC1 than in ARO cells (from anaplastic carcinoma) without alteration of total STAT-3 expression. Moreover, the RET/PTC-mediated transcriptional activation of STAT-3 was synergistically increased by over-expression of PLD, whereas the PLD activity as a lipid hydrolyzing enzyme was not affected by RET/PTC.</p> <p>Conclusion</p> <p>These findings led us to suggest that the PLD synergistically functions to activate the STAT3 signaling by interacting directly with the thyroid oncogenic kinase RET/PTC.</p

Anti-tumor effect of Liqi, a traditional Chinese medicine prescription, in tumor bearing mice

<p>Abstract</p> <p>Background</p> <p><it>Liqi</it>, an herbal preparation used in traditional Chinese medicine, has been used to treat cancer in China for centuries. We investigated the anti-tumor effects of liqi and their mechanisms in mice that had been xenografted with tumors.</p> <p>Methods</p> <p>Sarcoma 180 tumor, Lewis lung carcinoma, and SGC-7901 cells were implanted in BALB/c mice, C57BL/6 mice, and BALB/c nude mice, respectively. Liqi was administered to subgroups of these mice. The tumor weight and size were measured. Cell cycle analysis and T lymphocyte subsets were determined by flow cytometry. The activity of NK cells and TNF was tested using cytotoxicity assay on YAC-1 cells and L929 cells, respectively, and the activity of IL-2 was tested with an IL-2-dependent CTLL-2 cell proliferation assay. Platelet aggregation was monitored by measuring electric impedance, and the levels of thromboxane A2 (TXA₂) and prostacyclin (PGI₂) in blood were measured by ¹²⁵I-TXB₂and ¹²⁵I-Keto-PGF_1αradioimmunoassay.</p> <p>Results</p> <p>The results showed that liqi inhibited tumor growth in tumor-implanted mice and arrested the cell proliferation in the G0/G1 phase and reduced the portion of cells in S and G2/M phase for SGC-7901 cells. Liqi increased the activity of NK cells and TNF-α, stimulated IL-2 production and activity, and regulated T lymphocyte subpopulations. Liqi inhibited the Lewis lung carcinoma metastasis by inhibiting platelet aggregation and normalizing the balance between TXA₂and PGI₂.</p> <p>Conclusion</p> <p>All these findings demonstrated that liqi has an anti-tumor effect in vivo. The mechanism may be related to immune regulation and anticoagulation effects.</p