3,433 research outputs found

    Ruling out 100300\sim 100-300 GeV thermal relic annihilating dark matter by radio observation of the Andromeda galaxy

    Full text link
    In the past few years, some studies claimed that annihilating dark matter with mass 10100\sim 10-100 GeV can explain the GeV gamma-ray excess in our Galaxy. However, recent analyses of the Fermi-LAT and radio observational data rule out the possibility of the thermal relic annihilating dark matter with mass m100m \le 100 GeV for some popular annihilation channels. By using the new observed radio data of the Andromeda galaxy, we rule out the existence of 100300\sim 100-300 GeV thermal relic annihilating dark matter for ten annihilation channels. The lower limits of annihilating dark matter mass are improved to larger than 330 GeV for the most conservative case, which is a few times larger than the current best constraints. Moreover, these limits strongly disfavor the benchmark model of weakly interacting massive particle (WIMP) produced through the thermal freeze-out mechanism.Comment: Accepted in Ap

    Stepwise Increases in Left Ventricular Mass Index and Decreases in Left Ventricular Ejection Fraction Correspond with the Stages of Chronic Kidney Disease in Diabetes Patients

    Get PDF
    Aims. Patients with diabetic nephropathy are reported to have a high prevalence of left ventricular structural and functional abnormalities. This study was designed to assess the determinants of left ventricular mass index (LVMI) and left ventricular ejection fraction (LVEF) in diabetic patients at various stages of chronic kidney disease (CKD). Methods. This cross-sectional study enrolled 285 diabetic patients with CKD stages 3 to 5 from our outpatient department of internal medicine. Clinical and echocardiographic parameters were compared and analyzed. Results. We found a significant stepwise increase in LVMI (P < 0.001), LVH (P < 0.001), and LVEF <55% (P = 0.013) and a stepwise decrease in LVEF (P = 0.038) corresponding to advance in CKD stages. Conclusions. Our findings suggest that increases in LVMI and decreases in LVEF coincide with advances in CKD stages in patients with diabetes

    A Genome-Wide Analysis of Small Regulatory RNAs in the Human Pathogen Group A Streptococcus

    Get PDF
    The coordinated regulation of gene expression is essential for pathogens to infect and cause disease. A recently appreciated mechanism of regulation is that afforded by small regulatory RNA (sRNA) molecules. Here, we set out to assess the prevalence of sRNAs in the human bacterial pathogen group A Streptococcus (GAS). Genome-wide identification of candidate GAS sRNAs was performed through a tiling Affymetrix microarray approach and identified 40 candidate sRNAs within the M1T1 GAS strain MGAS2221. Together with a previous bioinformatic approach this brings the number of novel candidate sRNAs in GAS to 75, a number that approximates the number of GAS transcription factors. Transcripts were confirmed by Northern blot analysis for 16 of 32 candidate sRNAs tested, and the abundance of several of these sRNAs were shown to be temporally regulated. Six sRNAs were selected for further study and the promoter, transcriptional start site, and Rho-independent terminator identified for each. Significant variation was observed between the six sRNAs with respect to their stability during growth, and with respect to their inter- and/or intra-serotype-specific levels of abundance. To start to assess the contribution of sRNAs to gene regulation in M1T1 GAS we deleted the previously described sRNA PEL from four clinical isolates. Data from genome-wide expression microarray, quantitative RT-PCR, and Western blot analyses are consistent with PEL having no regulatory function in M1T1 GAS. The finding that candidate sRNA molecules are prevalent throughout the GAS genome provides significant impetus to the study of this fundamental gene-regulatory mechanism in an important human pathogen

    Discovery of serum biomarkers of alcoholic fatty liver in a rodent model: C-reactive protein

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Excessive consumption of alcohol contributes to alcoholic liver disease. Fatty liver is the early stage of alcohol-related liver disease. The aim of this study was to search for specific serological biomarkers of alcoholic fatty liver (AFL) compared to healthy controls, non-alcoholic fatty liver (NAFL) and liver fibrosis in a rodent model.</p> <p>Methods</p> <p>Serum samples derived from animals with AFL, NAFL, or liver fibrosis were characterized and compared using two-dimensional differential gel electrophoresis. A matrix-assisted laser desorption ionization-time of flight tandem mass spectrometer in conjunction with mascot software was used for protein identification. Subsequently, Western blotting and flexible multi-analyte profiling were used to measure the expressions of the putative biomarkers present in the serum of animals and clinical patients.</p> <p>Results</p> <p>Eight differential putative biomarkers were identified, and the two most differentiated proteins, including upregulated C-reactive protein (CRP) and downregulated haptoglobin (Hp), were further investigated. Western blotting validated that CRP was dramatically higher in the serum of AFL compared to healthy controls and other animals with liver disease of NAFL or liver fibrosis (<it>p </it>< 0.05). Moreover, we found that CRP and Hp were both lower in liver fibrosis of TAA-induced rats and clinical hepatitis C virus-infected patients.</p> <p>Conclusion</p> <p>The results suggest that increased levels of CRP are an early sign of AFL in rats. The abnormally elevated CRP induced by ethanol can be used as a biomarker to distinguish AFL from normal or otherwise diseased livers.</p

    Untangling operational performance implication of ambidextrous blockchain initiatives: An empirical investigation of Chinese manufacturers

    Get PDF
    Purpose Blockchain has been considered as a disruptive technology and every industry stands to benefit from it. According to Deloitte, increasing number of managers claim that their firms will suffer loss in competitive advantage if they do not adopt blockchain. Despite this motivation, insufficient knowledge on how can blockchain add value inhibits the commitment to its adoption. To better understand the possible influence of blockchain, two dimensions (exploitation and exploration) of blockchain initiatives are distinguished. This research aims to examine the impact of ambidextrous blockchain initiatives on firms' operational efficiency, as well as the moderating role of unabsorbed slack and environmental munificence. Design/methodology/approach In this paper, secondary panel data were collected from multiple sources to test the proposed hypotheses. Content analysis was adopted to operationalise ambidextrous blockchain initiatives from firms' official announcements. Findings The authors find that firms' ambidexterity in blockchain initiatives have significantly positive impact on operational efficiency. Furthermore, when firms have lower unabsorbed slack or in more munificent environments, they may benefit from managing a balance between exploration and exploitation. Originality/value This research offers some insightful theoretical and managerial implications of ambidextrous blockchain initiatives. The findings of this study contribute to blockchain literature by providing theory-driven empirical research
    corecore