1,500 research outputs found
Tracing magnetism and pairing in FeTe-based systems
In order to examine the interplay between magnetism and superconductivity, we
monitor the non- superconducting chalcogenide FeTe and follow its transitions
under insertion of oxygen, doping with Se and vacancies of Fe using
spin-polarized band structure methods (LSDA with GGA) starting from the
collinear and bicollinear magnetic arrangements. We use a supercell of Fe8Te8
as our starting point so that it can capture local changes in magnetic moments.
The calculated values of magnetic moments agree well with available
experimental data while oxygen insertions lead to significant changes in the
bicollinear or collinear magnetic moments. The total energies of these systems
indicate that the collinear-derived structure is the more favorable one prior
to a possible superconducting transition. Using a 8-site Betts-cluster-based
lattice and the Hubbard model, we show why this structure favors electron or
hole pairing and provides clues to a common understanding of charge and spin
pairing in the cuprates, pnictides and chalcogenides
Adjunctive mood stabilizer treatment for hospitalized schizophrenia patients: Asia psychotropic prescripton study (2001-2008)
Recent studies indicate relatively high international rates of adjunctive psychotropic medication, including mood stabilizers, for patients with schizophrenia. Since such treatments are little studied in Asia, we examined the frequency of mood-stabilizer use and its clinical correlates among hospitalized Asian patients diagnosed with schizophrenia in 2001-2008. We evaluated usage rates of mood stabilizers with antipsychotic drugs, and associated factors, for in-patients diagnosed with DSM-IV schizophrenia in 2001, 2004 and 2008 in nine Asian regions: China, Hong Kong, India, Korea, Japan, Malaysia, Taiwan, Thailand, and Singapore. Overall, mood stabilizers were given to 20.4% (n=1377/6761) of hospitalized schizophrenia patients, with increased usage over time. Mood-stabilizer use was significantly and independently associated in multivariate logistic modeling with: aggressive behaviour, disorganized speech, year sampled (2008 vs. earlier), multiple hospitalizations, less negative symptoms, younger age, with regional variation (Japan, Hong Kong, Singapore>Taiwan or China). Co-prescription of adjunctive mood stabilizers with antipsychotics for hospitalized Asian schizophrenia patients increased over the past decade, and was associated with specific clinical characteristics. This practice parallels findings in other countries and illustrates ongoing tension between evidence-based practice vs. individualized, empirical treatment of psychotic disorders.published_or_final_versio
Pleosporales
One hundred and five generic types of Pleosporales are described and illustrated. A brief introduction and detailed history with short notes on morphology, molecular phylogeny as well as a general conclusion of each genus are provided. For those genera where the type or a representative specimen is unavailable, a brief note is given. Altogether 174 genera of Pleosporales are treated. Phaeotrichaceae as well as Kriegeriella, Zeuctomorpha and Muroia are excluded from Pleosporales. Based on the multigene phylogenetic analysis, the suborder Massarineae is emended to accommodate five families, viz. Lentitheciaceae, Massarinaceae, Montagnulaceae, Morosphaeriaceae and Trematosphaeriaceae
Structure–property relation and relevance of beam theories for microtubules: a coupled molecular and continuum mechanics study
Quasi-one-dimensional microtubules (MTs) in cells enjoy high axial rigidity but large transverse flexibility due to the inter-protofilament (PF) sliding. This study aims to explore the structure–property relation for MTs and examine the relevance of the beam theories to their unique features. A molecular structural mechanics (MSM) model was used to identify the origin of the inter-PF sliding and its role in bending and vibration of MTs. The beam models were then fitted to the MSM to reveal how they cope with the distinct mechanical responses induced by the inter-PF sliding. Clear evidence showed that the inter-PF sliding is due to the soft inter-PF bonds and leads to the length-dependent bending stiffness. The Euler beam theory is found to adequately describe MT deformation when the inter-PF sliding is largely prohibited. Nevertheless, neither shear deformation nor the nonlocal effect considered in the ‘more accurate’ beam theories can fully capture the effect of the inter-PF sliding. This reflects the distinct deformation mechanisms between an MT and its equivalent continuous body
Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector
The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV
Performance of the CMS Cathode Strip Chambers with Cosmic Rays
The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device
in the CMS endcaps. Their performance has been evaluated using data taken
during a cosmic ray run in fall 2008. Measured noise levels are low, with the
number of noisy channels well below 1%. Coordinate resolution was measured for
all types of chambers, and fall in the range 47 microns to 243 microns. The
efficiencies for local charged track triggers, for hit and for segments
reconstruction were measured, and are above 99%. The timing resolution per
layer is approximately 5 ns
Tumor-induced STAT3 activation in monocytic myeloid-derived suppressor cells enhances stemness and mesenchymal properties in human pancreatic cancer
Pancreatic cancer (PC) mobilizes myeloid cells from the bone marrow to the tumor where they promote tumor growth and proliferation. Cancer stem cells (CSCs) are a population of tumor cells that are responsible for tumor initiation. Aldehyde dehydrogenase-1 activity in PC identifies CSCs, and its activity has been correlated with poor overall prognosis in human PC. Myeloid cells have been shown to impact tumor stemness, but the impact of immunosuppressive tumor-infiltrating granulocytic and monocytic myeloid-derived suppressor cells (Mo-MDSC) on ALDH1(Bright) CSCs and epithelial to mesenchymal transition is not well understood. In this study, we demonstrate that Mo-MDSC (CD11b(+)/Gr1(+)/Ly6G(−)/Ly6C(hi)) significantly increase the frequency of ALDH1(Bright) CSCs in a mouse model of PC. Additionally, there was significant upregulation of genes associated with epithelial to mesenchymal transition. We also found that human PC converts CD14(+) peripheral blood monocytes into Mo-MDSC (CD14(+)/HLA-DR(low/−)) in vitro, and this transformation is dependent on the activation of the STAT3 pathway. In turn, these Mo-MDSC increase the frequency of ALDH1(Bright) CSCs and promote mesenchymal features of tumor cells. Finally, blockade of STAT3 activation reversed the increase in ALDH1(Bright) CSCs. These data suggest that the PC tumor microenvironment transforms monocytes to Mo-MDSC by STAT3 activation, and these cells increase the frequency of ALDH1(Bright) CSCs. Therefore, targeting STAT3 activation may be an effective therapeutic strategy in targeting CSCs in PC. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s00262-014-1527-x) contains supplementary material, which is available to authorized users
Identification of Potent EGFR Inhibitors from TCM Database@Taiwan
Overexpression of epidermal growth factor receptor (EGFR) has been associated with cancer. Targeted inhibition of the EGFR pathway has been shown to limit proliferation of cancerous cells. Hence, we employed Traditional Chinese Medicine Database (TCM Database@Taiwan) (http://tcm.cmu.edu.tw) to identify potential EGFR inhibitor. Multiple Linear Regression (MLR), Support Vector Machine (SVM), Comparative Molecular Field Analysis (CoMFA), and Comparative Molecular Similarities Indices Analysis (CoMSIA) models were generated using a training set of EGFR ligands of known inhibitory activities. The top four TCM candidates based on DockScore were 2-O-caffeoyl tartaric acid, Emitine, Rosmaricine, and 2-O-feruloyl tartaric acid, and all had higher binding affinities than the control Iressa®. The TCM candidates had interactions with Asp855, Lys716, and Lys728, all which are residues of the protein kinase binding site. Validated MLR (r² = 0.7858) and SVM (r² = 0.8754) models predicted good bioactivity for the TCM candidates. In addition, the TCM candidates contoured well to the 3D-Quantitative Structure-Activity Relationship (3D-QSAR) map derived from the CoMFA (q² = 0.721, r² = 0.986) and CoMSIA (q² = 0.662, r² = 0.988) models. The steric field, hydrophobic field, and H-bond of the 3D-QSAR map were well matched by each TCM candidate. Molecular docking indicated that all TCM candidates formed H-bonds within the EGFR protein kinase domain. Based on the different structures, H-bonds were formed at either Asp855 or Lys716/Lys728. The compounds remained stable throughout molecular dynamics (MD) simulation. Based on the results of this study, 2-O-caffeoyl tartaric acid, Emitine, Rosmaricine, and 2-O-feruloyl tartaric acid are suggested to be potential EGFR inhibitors.National Science Council of Taiwan (NSC 99-2221-E-039-013-)Committee on Chinese Medicine and Pharmacy (CCMP100-RD-030)China Medical University (CMU98-TCM)China Medical University (CMU99-TCM)China Medical University (CMU99-S-02)China Medical University (CMU99-ASIA-25)China Medical University (CMU99-ASIA-26)China Medical University (CMU99-ASIA-27)China Medical University (CMU99-ASIA-28)Asia UniversityTaiwan Department of Health. Clinical Trial and Research Center of Excellence (DOH100-TD-B-111-004)Taiwan Department of Health. Cancer Research Center of Excellence (DOH100-TD-C-111-005
Characterization of an Alkali- and Halide-Resistant Laccase Expressed in E. coli: CotA from <i>Bacillus clausii</i>
The limitations of fungal laccases at higher pH and salt concentrations have intensified the search for new extremophilic bacterial laccases. We report the cloning, expression, and characterization of the bacterial cotA from Bacillus clausii, a supposed alkalophilic ortholog of cotA from B. subtilis. Both laccases were expressed in E. coli strain BL21(DE3) and characterized fully in parallel for strict benchmarking. We report activity on ABTS, SGZ, DMP, caffeic acid, promazine, phenyl hydrazine, tannic acid, and bilirubin at variable pH. Whereas ABTS, promazine, and phenyl hydrazine activities vs. pH were similar, the activity of B. clausii cotA was shifted upwards by ~0.5-2 pH units for the simple phenolic substrates DMP, SGZ, and caffeic acid. This shift is not due to substrate affinity (K(M)) but to pH dependence of catalytic turnover: The k(cat) of B. clausii cotA was 1 s⁻¹ at pH 6 and 5 s⁻¹ at pH 8 in contrast to 6 s⁻¹ at pH 6 and 2 s⁻¹ at pH 8 for of B. subtilis cotA. Overall, k(cat)/K(M) was 10-fold higher for B. subtilis cotA at pH(opt). While both proteins were heat activated, activation increased with pH and was larger in cotA from B. clausii. NaCl inhibited activity at acidic pH, but not up to 500-700 mM NaCl in alkaline pH, a further advantage of the alkali regime in laccase applications. The B. clausii cotA had ~20 minutes half-life at 80°C, less than the ~50 minutes at 80°C for cotA from B. subtilis. While cotA from B. subtilis had optimal stability at pH~8, the cotA from B. clausii displayed higher combined salt- and alkali-resistance. This resistance is possibly caused by two substitutions (S427Q and V110E) that could repel anions to reduce anion-copper interactions at the expense of catalytic proficiency, a trade-off of potential relevance to laccase optimization
Access to high cost medicines in Australia: ethical perspectives
Access to "high cost medicines" through Australia's Pharmaceutical Benefits Scheme (PBS) is tightly regulated. It is inherently difficult to apply any criteria-based system of control in a way that provides a fair balance between efficient use of limited resources for community needs and equitable individual access to care. We suggest, in relation to very high cost medicines, that the present arrangements be re-considered in order to overcome potential inequities. The biological agents for the treatment of rheumatoid arthritis are used as an example by which to discuss the ethical issues associated with the current scheme. Consideration of ethical aspects of the PBS and similar programs is important in order to achieve the fairest outcomes for individual patients, as well as for the community
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