682 research outputs found
Effects of a type-II RNA-binding protein on fatty acid composition in Synechocystis sp. PCC 6803
In the cyanobacterium Synechocystis 6803, rbp3, a type-II RNA-binding protein gene, is slightly induced by temperature downshift. An rbp3 mutant shows significant reduction in total polyunsaturated fatty acids (PUFA) in membrane lipids. However, the reduction in PUFA has not attained the extent that would significantly affect the growth of the mutant at low temperature. Transcripts of fatty acid desaturase genes desA, desB and desD, and ccr-1, a gene required for growth at 15°C, are significantly reduced in the mutant relative to the wild type, while transcripts of rbp1 (RNA-binding protein 1) and crhR (RNA helicase Light) are not affected. Rbp3 may directly or indirectly affect mRNA levels of certain genes
Graphene Photonics and Optoelectronics
The richness of optical and electronic properties of graphene attracts
enormous interest. Graphene has high mobility and optical transparency, in
addition to flexibility, robustness and environmental stability. So far, the
main focus has been on fundamental physics and electronic devices. However, we
believe its true potential to be in photonics and optoelectronics, where the
combination of its unique optical and electronic properties can be fully
exploited, even in the absence of a bandgap, and the linear dispersion of the
Dirac electrons enables ultra-wide-band tunability. The rise of graphene in
photonics and optoelectronics is shown by several recent results, ranging from
solar cells and light emitting devices, to touch screens, photodetectors and
ultrafast lasers. Here we review the state of the art in this emerging field.Comment: Review Nature Photonics, in pres
Observation of CR Anisotropy with ARGO-YBJ
The measurement of the anisotropies of cosmic ray arrival direction provides
important informations on the propagation mechanisms and on the identification
of their sources. In this paper we report the observation of anisotropy regions
at different angular scales. In particular, the observation of a possible
anisotropy on scales between 10 and 30
suggests the presence of unknown features of the magnetic fields the charged
cosmic rays propagate through, as well as potential contributions of nearby
sources to the total flux of cosmic rays. Evidence of new weaker few-degree
excesses throughout the sky region R.A. is
reported for the first time.Comment: Talk given at 12th TAUP Conference 2011, 5-9 September 2011, Munich,
German
Observation of the cosmic ray moon shadowing effect with the ARGO-YBJ experiment
Cosmic rays are hampered by the Moon and a deficit in its direction is expected (the so-called Moon shadow). The Moon shadow is an important tool to determine the performance of an air shower array. Indeed, the westward displacement of the shadow center, due to the bending effect of the geomagnetic field on the propagation of cosmic rays, allows the setting of the absolute rigidity scale of the primary particles inducing the showers recorded by the detector. In addition, the shape of the shadow permits to determine the detector point spread function, while the position of the deficit at high energies allows the evaluation of its absolute pointing accuracy. In this paper we present the observation of the cosmic ray Moon shadowing effect carried out by the ARGO-YBJ experiment in the multi-TeV energy region with high statistical significance (55 standard deviations). By means of an accurate Monte Carlo simulation of the cosmic rays propagation in the Earth-Moon system, we have studied separately the effect of the
geomagnetic field and of the detector point spread function on the observed shadow. The angular resolution as a function of the particle multiplicity and the pointing accuracy have been obtained. The primary energy of detected showers has been estimated by measuring the westward displacement as a function of the particle multiplicity, thus calibrating the relation between shower size and cosmic ray energy. The stability of the detector on a monthly basis has been checked by monitoring the position and the deficit of the Moon shadow. Finally, we have studied with high statistical accuracy the shadowing effect in the ''day/night’’ time looking for possible effect induced by the solar wind
Oxymatrine Alleviates Central Post-Stroke Pain in Rats by Reducing the Inflammatory Response
Hai-Li Li,1– 3 Xing-Ping Tan,1,3 Xiao-Die Wang,1,3 Ren-Tian Guo,1,3 Jiang-Lin Wang1,3,4 1Department of Pain Management, The Affiliated Hospital, Southwest Medical University, Luzhou, People’s Republic of China; 2Department of Anesthesiology, The Affiliated Tianfu Hospital, Southwest Medical University, Meishan, People’s Republic of China; 3Anesthesiology and Critical Care Medicine Key Laboratory of Luzhou, Southwest Medical University, Luzhou, Sichuan, People’s Republic of China; 4Department of Pain Management, The Affiliated Tianfu Hospital, Southwest Medical University, Meishan, People’s Republic of ChinaCorrespondence: Jiang-Lin Wang, Pain Department, The Affiliated Hospital, Southwest Medical University, No. 25 Pacific Street, Luzhou, 646000, People’s Republic of China, Tel +8618090880626, Fax +0830-3165469, Email [email protected] and Purpose: Central post-stroke pain (CPSP) is directly caused by cerebrovascular diseases that affect the central somatosensory system. It is a serious, chronic central neuropathic pain that responds poorly to first-line drugs. Oxymatrine (OMT), a monomer derived from the traditional Chinese medicine Sophora flavescens Ait. exhibits anti-inflammatory, analgesic, and organ- and tissue-protective properties. This study aimed to investigate the therapeutic effects of OMT in a rat model of CPSP.Methods: Gene Ontology (GO) enrichment analysis was initially employed to elucidate the role of OMT on CPSP target proteins in terms of gene function. Then the CPSP model was induced through focal hemorrhage in the ventral posterolateral nucleus (VPL). Rats were randomly assigned to five groups (n = 10): sham + NaCl, CPSP + NaCl, and CPSP + OMT (100 mg/kg, 200 mg/kg, 400 mg/kg). Daily intraperitoneal injections of NaCl or varying doses of OMT were administered from days 7 to 14 after model establishment, and paw withdrawal mechanical thresholds (PWMT) were assessed. The optimal OMT dose (200 mg/kg) was determined based on PWMT measurements. On day 14, inflammatory markers (IL-1β, IL-6, TNF-α) and alterations in microglia and astrocyte activity at the thalamic lesion site were analyzed.Results: Elevated levels of IL-1β, IL-6, and TNF-α (P < 0.05) and activation of microglia and astrocytes were observed around the peri-thalamic lesion in CPSP rats. OMT administration significantly reduced mechanical allodynia (P < 0.05), decreased inflammatory cytokine expression (P < 0.05), and inhibited microglial and astrocytic activation.Conclusion: OMT mitigates central post-stroke pain in rats by attenuating the inflammatory response at the thalamic lesion site.Keywords: central post-stroke pain, oxymatrine, inflammation, thalamic lesions, mechanical allodyni
Highlights from the ARGO-YBJ experiment
The ARGO-YBJ experiment at YangBaJing in Tibet (4300 m a.s.l.) has been taking data with its full layout since October 2007. Here we present a few significant results obtained in gamma-ray astronomy and cosmic-ray physics. Emphasis is placed on the analysis of gamma-ray emission from point-like sources (Crab Nebula, MRK 421), on the preliminary limit on the antiproton/proton flux ratio, on the large-scale cosmic-ray anisotropy and on the proton–air cross-section. The performance of the detector is also discussed, and the perspectives of the experiment are outlined
Business ethics and finance in Greater China:Synthesis and future directions in sustainability, CSR, and fraud
Following the financial crisis and recent recession, the center of gravity of global economic growth and competitiveness is shifting toward emerging economies. As a leading and increasingly influential emerging economy, China is currently attracting the attention of academics, practitioners, and policy makers. There is a rise of research interest in and publications on issues relating to China within high-quality international academic journals. We therefore organized a special issue conference in conjunction with the Journal of Business Ethics (JBE) in Lhasa, Tibet, on May 19-20, 2014, on the topic of Business Ethics in Greater China: Past, Present and Future. The papers for the special issue were at the intersection of ethics and finance, and fit within one of three themes: environment and sustainability, corporate social responsibility, and fraud. Within these themes, issues of intellectual capital protection, gender equality, political connections, regional development, investor protection, corporate stewardship, trust and corruption, and corporate transparency each play a significant role. In this paper, we survey these studies and the related literature to provide a comprehensive coverage of business ethics and finance issues that affect China
An analysis of hospital preparedness capacity for public health emergency in four regions of China: Beijing, Shandong, Guangxi, and Hainan
17β-Estradiol Enhances Breast Cancer Cell Motility and Invasion via Extra-Nuclear Activation of Actin-Binding Protein Ezrin
Estrogen promotes breast cancer metastasis. However, the detailed mechanism remains largely unknown. The actin binding protein ezrin is a key component in tumor metastasis and its over-expression is positively correlated to the poor outcome of breast cancer. In this study, we investigate the effects of 17β-estradiol (E2) on the activation of ezrin and its role in estrogen-dependent breast cancer cell movement. In T47-D breast cancer cells, E2 rapidly enhances ezrin phosphorylation at Thr567 in a time- and concentration-dependent manner. The signalling cascade implicated in this action involves estrogen receptor (ER) interaction with the non-receptor tyrosine kinase c-Src, which activates the phosphatidylinositol-3 kinase/Akt pathway and the small GTPase RhoA/Rho-associated kinase (ROCK-2) complex. E2 enhances the horizontal cell migration and invasion of T47-D breast cancer cells in three-dimensional matrices, which is reversed by transfection of cells with specific ezrin siRNAs. In conclusion, E2 promotes breast cancer cell movement and invasion by the activation of ezrin. These results provide novel insights into the effects of estrogen on breast cancer progression and highlight potential targets to treat endocrine-sensitive breast cancers
High prevalence of plasmid-mediated 16S rRNA methylase gene rmtB among Escherichia coli clinical isolates from a Chinese teaching hospital
<p>Abstract</p> <p>Background</p> <p>Recently, production of 16S rRNA methylases by Gram-negative bacilli has emerged as a novel mechanism for high-level resistance to aminoglycosides by these organisms in a variety of geographic locations. Therefore, the spread of high-level aminoglycoside resistance determinants has become a great concern.</p> <p>Methods</p> <p>Between January 2006 and July 2008, 680 distinct <it>Escherichia coli </it>clinical isolates were collected from a teaching hospital in Wenzhou, China. PCR and DNA sequencing were used to identify 16S rRNA methylase and extended-spectrum β-lactamase (ESBL) genes, including <it>armA </it>and <it>rmtB</it>, and in situ hybridization was performed to determine the location of 16S rRNA methylase genes. Conjugation experiments were subsequently performed to determine whether aminoglycoside resistance was transferable from the <it>E. coli </it>isolates via 16S rRNA methylase-bearing plasmids. Homology of the isolates harboring 16S rRNA methylase genes was determined using pulse-field gel electrophoresis (PFGE).</p> <p>Results</p> <p>Among the 680 <it>E. coli </it>isolates, 357 (52.5%), 346 (50.9%) and 44 (6.5%) isolates were resistant to gentamicin, tobramycin and amikacin, respectively. Thirty-seven of 44 amikacin-resistant isolates harbored 16S rRNA methylase genes, with 36 of 37 harboring the <it>rmtB </it>gene and only one harboring <it>armA</it>. The positive rates of 16S rRNA methylase genes among all isolates and amikacin-resistant isolates were 5.4% (37/680) and 84.1% (37/44), respectively. Thirty-one isolates harboring 16S rRNA methylase genes also produced ESBLs. In addition, high-level aminoglycoside resistance could be transferred by conjugation from four <it>rmtB</it>-positive donors. The plasmids of incompatibility groups IncF, IncK and IncN were detected in 34, 3 and 3 isolates, respectively. Upstream regions of the <it>armA </it>gene contained <it>IS</it>CR1 and <it>tnpU</it>, the latter a putative transposase gene,. Another putative transposase gene, <it>tnpD</it>, was located within a region downstream of <it>armA</it>. Moreover, a transposon, Tn<it>3</it>, was located upstream of the <it>rmtB</it>. Nineteen clonal patterns were obtained by PFGE, with type H representing the prevailing pattern.</p> <p>Conclusion</p> <p>A high prevalence of plasmid-mediated <it>rmtB </it>gene was found among clinical <it>E. coli </it>isolates from a Chinese teaching hospital. Both horizontal gene transfer and clonal spread were responsible for the dissemination of the <it>rmtB </it>gene.</p
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