Electronic Properties of Topological Materials: Optical Excitations in Moebius Conjugated Polymers

Electronic structures and optical excitations in Moebius conjugated polymers are studied theoretically. Periodic and Moebius boundary conditions are applied to the tight binding model of poly(para-phenylene), taking exciton effects into account. We discuss that oligomers with a few structural units are more effective than polymers for observations of effects of discrete wave numbers that are shifted by the change in boundary condition. Next, calculations of optical absorption spectra are reported. Certain components of optical absorption for an electric field perpendicular to the polymer axis mix with absorption spectra for an electric field parallel to the polymer axis. Therefore, the polarization dependences of an electric field of light enable us to detect whether conjugated polymers have the Moebius boundary.Comment: 10 pages, 6 figures, to be published in J. Phys. Soc. Jpn., Vol. 74 No. 2 (February, 2005), Letter sectio

ATP-dependent potassium channels are implicated in simvastatin pretreatment-induced inhibition of apoptotic cell death after renal ischemia/reperfusion injury

Background: Simvastatin is a widely used medication in cardiac care. Here we evaluate the role of ATP sensitive potassium (KATP) channels in simvastatin induced renal protection after renal ischemia/reperfusion (I/R) injury. Methods: A total of 81 male Wistar rats, were treated with simvastatin (10 and 20mg/kg/day; gavage, one week). Some groups received glibenclamide (KATP channel inhibitor; 5mg/kg) before ischemia (45min) and reperfusion (24h). Finally the kidneys were processed for histological analysis and measurement of biochemical parameters including tissue malondialdehyde (MDA), blood urea nitrogen (BUN), fractional excretion of sodium (FENa), creatinine clearance rate (CCr) and Bcl2-associated X protein (Bax) expression. Results: IR significantly increased serum Cr (p< 0.01) and BUN levels (p< 0.01), elevated FENa (p<0.01) and tissue MDA (p<0.01), and decreased CCr (p< 0.01) and induced histological damage. Bax pro-apoptotic protein was upregulated in renal tissue after I/R injury and downregulated in simvastatin pretreated group. Simvastatin at doses of 10 and 20mg/kg/day significantly reduced serum Cr and BUN levels (p< 0.05 vs. IR group), tissue MDA contents and FENa (p< 0.05 vs. I/R) and increased CCr (p< 0.05 vs. IR). Renal tissue injury was improved only in simvastatin 20mg/kg/day group (p< 0.05). Glibenclamide significantly abolished protective effects of simvastatin and increased serum Cr and BUN and FENa and decreased CCr (p< 0.05). It also abolished the effects of simvastatin on tissue injury and MDA contents and downregulated the Bax protein after IR injury (p< 0.05). Conclusion: Opening of KATP channels is essential for simvastatin-induced renal protection against I/R injury

IN VITRO EQUIVALENCE STUDY OF GENERIC METFORMIN HYDROCHLORIDE TABLETS UNDER BIOWAIVER CONDITIONS

Background: Generic drugs are smarter alternative to expensive brands, it is bio- equivalent formula of any branded drug. FDA approved that generic drugs are the safest to consume, the medicines meet the similar manufacturing standards followed while producing an innovator drug, however, the color, shape, taste and packaging of generics is different from the innovator product. In short, a generic drug should be bioequivalent to its brand counterpart. Metformin was initially marketed under the name of Glucophage®, and now the market is loaded by generics of different origin, and price variability. Method: Our study was conducted to determine whether metformin generics are bioequivalent to the innovator drug Glucophage®. In-vitro bioequivalence testing under Biowaiver conditions can predict bioequivalence in a safe, fast, and less expensive method. Thus, study was performed on Metformin tablets to assess whether generics are bioequivalent to the innovator and hence be interchangeable. Results: The quality control results of the thickness, hardness, friability, disintegration, weight uniformity, content uniformity, and assay showed that most metformin tablets complied with the USP 34 NF29 2011 specifications. Dissolution testing under biowaiver conditions showed different results. All tablets of the generics and innovator Glucophage® were able to dissolve by more than 85% within 15 min. Two generics were bioequivalent to the innovator Glucophage® having f2≥ 50 in the three dissolution media. The rest of generics showed variable results. Conclusion: Generics of metformin varied in their bioequivalency to the innovator Gluocophage®. This variation could be explained by different excipients, and manufacturing conditions. In-vivo bioequivalence testing should be conducted to confirm that the innovator could be safely interchangeable with the brand and this variation won’t affect the safety and efficacy of the drug

An Integrated Hydrologic Bayesian Multi-Model Combination Framework: Confronting Input, parameter and model structural uncertainty in Hydrologic Prediction

This paper presents a new technique--Integrated Bayesian Uncertainty Estimator (IBUNE) to account for the major uncertainties of hydrologic rainfall-runoff predictions explicitly. The uncertainties from the input (forcing) data--mainly the precipitation observations and from the model parameters are reduced through a Monte Carlo Markov Chain (MCMC) scheme named Shuffled Complex Evolution Metropolis (SCEM) algorithm which has been extended to include a precipitation error model. Afterwards, the Bayesian Model Averaging (BMA) scheme is employed to further improve the prediction skill and uncertainty estimation using multiple model output. A series of case studies using three rainfall-runoff models to predict the streamflow in the Leaf River basin, Mississippi are used to examine the necessity and usefulness of this technique. The results suggests that ignoring either input forcings error or model structural uncertainty will lead to unrealistic model simulations and their associated uncertainty bounds which does not consistently capture and represent the real-world behavior of the watershed

Multi-Model Combination techniques for Hydrological Forecasting: Application to Distributed Model Intercomparison Project Results

This paper examines several multi-model combination techniques: the Simple Multi-model Average (SMA), the Multi-Model Super Ensemble (MMSE), Modified Multi-Model Super Ensemble (M3SE) and the Weighted Average Method (WAM). These model combination techniques were evaluated using the results from the Distributed Model Intercomparison Project (DMIP), an international project sponsored by the National Weather Service (NWS) Office of Hydrologic Development (OHD). All of the multi-model combination results were obtained using uncalibrated DMIP model outputs and were compared against the best uncalibrated as well as the best calibrated individual model results. The purpose of this study is to understand how different combination techniques affect the skill levels of the multi-model predictions. This study revealed that the multi-model predictions obtained from uncalibrated single model predictions are generally better than any single member model predictions, even the best calibrated single model predictions. Furthermore, more sophisticated multi-model combination techniques that incorporated bias correction steps work better than simple multi-model average predictions or multi-model predictions without bias correction

Delivery of healthcare provider’s lifestyle advice and lifestyle behavioural change in adults who were overweight or obese in pre-diabetes management in the USA: NHANES (2013–2018)

Objective: The purpose of this study is to examine the association between delivery of healthcare provider's advice about lifestyle management and lifestyle behavioural change in pre-diabetes management in adults who were overweight or obese. Design: This cross-sectional study included adults with body mass index (BMI) ≥25 kg/m2 and reporting pre-diabetes in USA. Outcomes included the prevalence of receiving provider's advice on lifestyle management and patterns of practicing lifestyle change. The association between delivery of provider's advice and lifestyle-related behavioural change in pre-diabetes management was examined. Setting: US Continuous National Health and Nutrition Examination Survey (2013-2018). Participants: A total of 1039 adults with BMI ≥25 kg/m2 reported pre-diabetes. Results: Of eligible adults with pre-diabetes, 76.8% received provider's advice about lifestyle change. The advice group showed higher proportions of ongoing lifestyle change than no advice group, including weight reduction/control (80.1% vs 70.9%, p=0.018), exercise (70.9% vs 60.9%, p=0.013) and diet modifications (83.8% vs 61.8%, p<0.001). After adjustment, those receiving provider's advice were more likely to increase exercise (OR 1.63, 95% CI 1.12 to 2.38) and modify diet (OR 3.0, 95% CI 1.82 to 4.96). Conclusion: Over 75% of US adults who were overweight or obese and reported pre-diabetes received healthcare provider's advice about reducing the risk of diabetes through lifestyle change. Provider's advice increased the likelihood of lifestyle-related behavioural change to exercise and diet

Telemedicine use in 2020 during the COVID-19 pandemic among community dwelling U.S. Medicare beneficiaries

Objective: CMS reimbursement regulations for telemedicine changed after the onset of the COVID-19 pandemic. This study aimed to assess telemedicine utilization patterns offered by health care providers and used by Medicare beneficiaries during the COVID-19 pandemic during 2020. Methods: This study used the Fall 2020 Medicare Current Beneficiary Survey (MCBS) supplemental COVID-19 survey to identify Medicare beneficiaries (≥ 65 years) with a regular place for medical care that offered telemedicine during 2020. Major outcomes: prevalence for whether telemedicine was offered before and during the pandemic, telemedicine use, and digital access to telemedicine. Logistic regression identified the demographic factors associated with telemedicine use. Results: The study sample included 4,380 eligible individual Medicare beneficiaries ≥ 65 years. Of those, 42.9% made telemedicine visits during the pandemic. Approximately 60% of the telemedicine visits were conducted via telephone. Telemedicine was offered to 18% of the respondents before the pandemic vs. 64% during year 2020 of the pandemic. Among telemedicine users, 57.2%, 28.3%, and 14.5% used voice calls, video calls, and both voice and video calls for health care appointments, respectively. Overall telemedicine use varied by sex, race, and region. Individuals 65-74 years, female, living in a metropolitan area, with higher incomes were more likely to make video visits. Experience using telecommunications via the internet influenced telemedicine use significantly. Conclusions: Telemedicine offered to older Medicare beneficiaries increased dramatically after the onset of the COVID-19 pandemic. Yet, less than half used telemedicine and differences in utilization existed by demographic characteristics

Spin states of zigzag-edged Mobius graphene nanoribbons from first principles

Mobius graphene nanoribbons have only one edge topologically. How the magnetic structures, previously associated with the two edges of zigzag-edged flat nanoribbons or cyclic nanorings, would change for their Mobius counterparts is an intriguing question. Using spin-polarized density functional theory, we shed light on this question. We examine spin states of zigzag-edged Mobius graphene nanoribbons (ZMGNRs) with different widths and lengths. We find a triplet ground state for a Mobius cyclacene, while the corresponding two-edged cyclacene has an open-shell singlet ground state. For wider ZMGNRs, the total magnetization of the ground state is found to increase with the ribbon length. For example, a quintet ground state is found for a ZMGNR. Local magnetic moments on the edge carbon atoms form domains of majority and minor spins along the edge. Spins at the domain boundaries are found to be frustrated. Our findings show that the Mobius topology (i.e., only one edge) causes ZMGNRs to favor one spin over the other, leading to a ground state with non-zero total magnetization.Comment: 17 pages, 4 figure

The intrahepatic signalling niche of hedgehog is defined by primary cilia positive cells during chronic liver injury

Background & Aims: In vertebrates, canonical Hedgehog (Hh) pathway activation requires Smoothened (SMO) translocation to the primary cilium (Pc), followed by a GLI-mediated transcriptional response. In addition, a similar gene regulation occurs in response to growth factors/cytokines, although independently of SMO signalling. The Hh pathway plays a critical role in liver fibrosis/regeneration; however, the mechanism of activation in chronic liver injury is poorly understood. This study aimed to characterise Hh pathway activation upon thioacetamide (TAA)- induced chronic liver injury in vivo by defining Hh-responsive cells, namely cells harbouring Pc and Pc-localised SMO. Methods: C57BL/6 mice (wild-type or Ptc1+/_) were TAA-treated. Liver injury and Hh ligand/pathway mRNA and protein expression were assessed in vivo. SMO/GLI manipulation and SMO dependent/ independent activation of GLI-mediated transcriptional response in Pc-positive (Pc+) cells were studied in vitro. Results: In vivo, Hh activation was progressively induced following TAA. At the epithelial-mesenchymal interface, injured hepatocytes produced Hh ligands. Progenitors, myofibroblasts, leukocytes and hepatocytes were GLI2+. Pc+ cells increased following TAA, but only EpCAM+/GLI2+ progenitors were Pc+/SMO+. In vitro, SMO knockdown/hGli3-R overexpression reduced proliferation/viability in Pc+ progenitors, whilst increased proliferation occurred with hGli1 overexpression. HGF induced GLI transcriptional activity independently of Pc/SMO. Ptc1+/_ mice exhibited increased progenitor, myofibroblast and fibrosis responses. Conclusions: In chronic liver injury, Pc+ progenitors receive Hh ligand signals and process it through Pc/SMO-dependent activation of GLI-mediated transcriptional response. Pc/SMO-independent GLI activation likely occurs in Pc_/GLI2+ cells. Increased fibrosis in Hh gain-of-function mice likely occurs by primary progenitor expansion/proliferation and secondary fibrotic myofibroblast expansion, in close contact with progenitors