1,340 research outputs found

    Subdiffusive spin transport in disordered classical Heisenberg chains

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    We study the transport and equilibration properties of a classical Heisenberg chain, whose couplings are random variables drawn from a one-parameter family of power-law distributions. The absence of a scale in the couplings makes the system deviate substantially from the usual paradigm of diffusive spin hydrodynamics, and exhibit a regime of subdiffusive transport with an exponent changing continuously with the parameter of the distribution. We propose a solvable phenomenological model that correctly yields the subdiffusive exponent, thereby linking local fluctuations in the coupling strengths to the long-time, large-distance behaviour. It also yields the finite-time corrections to the asymptotic scaling, which can be important in fitting the numerical data. We show how such exponents undergo transitions as the distribution of the coupling gets wider, marking the passage from diffusion to a regime of slow diffusion, and finally to subdiffusion.Comment: 10+3 pages, 5+4 figure

    Selective expression of RT6 superfamily in human bronchial epithelial cells.

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    RT6 proteins are glycosylphosphatidylinositol (GPI)-linked alloantigens that are localized to cytotoxic T lymphocytes and that have nicotinamide adenine dinucleotide glycohydrolase and adenosine diphosphate (ADP)-ribosyltransferase activities. In view of the importance of GPI-linked surface proteins in mediating interactions of cells with their milieu, and the varied functions of airway cells in inflammation, we undertook the present study to determine whether human homologues of the RT6 superfamily of ADP-ribosyltransferases (ART) are expressed in pulmonary epithelial cells. We hypothesized that these surface proteins or related family members may be present in cells that interact with inflammatory cells, and that they may thereby be involved in intercellular signaling. Using in situ analysis and Northern blot analysis, we identified ART1 messenger RNA (mRNA) in airway epithelial cells. As expected for GPI-anchored proteins, the localization of ART1 at the apical surface of ciliated epithelial cells was demonstrated by staining with polyclonal anti-ART1 antibody, and was confirmed by loss of this immunoreactivity after treatment with phosphatidylinositol-specific phospholipase C (PI-PLC), which selectively cleaves GPI anchors and releases proteins from the plasma membrane. Using in situ hybridization with specific ART3 and ART4 oligonucleotides, we also identified two additional members of the RT6 superfamily in epithelial cells. In accord with these findings, we identified ART3 and ART4 mRNAs through reverse transcription- polymerase chain reaction of polyadenine-positive RNA from human trachea. Interestingly, these proteins appeared to be preferentially localized to the airway epithelium. The localized expression of these members of the RT6 superfamily in human pulmonary epithelial cells may reflect a role for them in cell-cell signaling during immune responses within the airwa

    Impact of 3-Cyanopropionic Acid Methyl Ester on the Electrochemical Performance of ZnMn₂O₄ as Negative Electrode for Li-Ion Batteries

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    Due to their high theoretical capacity, transition metal oxide compounds are promising electrode materials for lithium-ion batteries. However, one drawback is associated with relevant capacity fluctuations during cycling, widely observed in the literature. Such strong capacity variation can result in practical problems when positive and negative electrode materials have to be matched in a full cell. Herein, the study of ZnMn2O4 (ZMO) in a nonconventional electrolyte based on 3-cyanopropionic acid methyl ester (CPAME) solvent and LiPF6 salt is reported for the first time. Although ZMO in LiPF6/CPAME electrolyte displays a dramatic capacity decay during the first cycles, it shows promising cycling ability and a suppressed capacity fluctuation when vinylene carbonate (VC) is used as an additive to the CPAME-based electrolyte. To understand the nature of the solid electrolyte interphase (SEI), the electrochemical study is correlated to ex situ X-ray photoelectron spectroscopy (XPS)

    Changes in insulin sensitivity in response to different modalities of exercise: a review of the evidence

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    Summary: Type 2 diabetes is an increasingly prevalent condition with complications including blindness and kidney failure. Evidence suggests that type 2 diabetes is associated with a sedentary lifestyle, with physical activity demonstrated to increase glucose uptake and improve glycaemic control. Proposed mechanisms for these effects include the maintenance and improvement of insulin sensitivity via increased glucose transporter type four production. The optimal mode, frequency, intensity and duration of exercise for the improvement of insulin sensitivity are however yet to be identified. We review the evidence from 34 published studies addressing the effects on glycaemic control and insulin sensitivity of aerobic exercise, resistance training and both combined. Effect sizes and confidence intervals are reported for each intervention and meta-analysis presented. The quality of the evidence is tentatively graded, and recommendations for best practice proposed

    Attitude towards drug therapy in a Community Mental Health Center evaluated by the Drug Attitude Inventory

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    Introduction: Negative attitude towards drug therapy can foster limited adherence to treatment, which remains one of the biggest obstacles for implementing effective treatments, especially long term. Purposes: The purposes of the study were 1) to evaluate the attitude towards drug therapy among a representative sample of patients treated in a community psychiatric service using 30-item Drug Attitude Inventory (DAI-30); 2) to evaluate the DAI-30 dimensions, applying factorial analysis; and 3) to highlight the socio-demographic and clinical variables correlated to DAI-30 score and factors. Methods: The DAI was administered, over a 7-month period, to all patients treated in our psychiatric outpatient services who agreed to participate in this study and provided their informed consent. Data were statistically analyzed. Results: With a response rate of 63.3%, 164 females and 136 males completed the DAI-30 with an average score of 14.24 (±10.46 SD), indicating moderately positive attitude towards drug therapy. The analysis of DAI-30 internal consistency confirmed its reliability (Cronbach’s alpha=0.84). Our factorial analysis highlighted three factors: Factor 1 (Cronbach’s alpha=0.81), composed of 7 items which indicate positive, trustful attitude; Factor 2 (Cronbach’s alpha=0.78), composed of 5 items indicating negative attitude of suspiciousness; and Factor 3 (Cronbach’s alpha=0.66), composed of 4 items suggesting defensive and control attitude towards drug therapy. Discussion: Among the selected variables, “monotherapy” and “total number of hospitalizations” were negatively correlated to the final score of DAI-30, whereas being “married” was positively correlated to it, in a statistically significant way, using the multiple linear regression model. These correlations suggest that positive attitude towards drug therapy could be reinforced by the condition of being married and reduced by relapses with hospitalization, as literature highlighted, and, paradoxically, by a monotherapy, which could suggest a sort of psychological dependence on therapy and, indirectly, on psychiatric service, potentially correlated to the long-term treatments of our patients

    Validasi Metode Analisis Klorfeniramin Maleat Dan Guaifenesin Menggunakan Kromatografi Cair Kinerja Tinggi Serta Aplikasinya Dalam Sediaan Sirup

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    The combination of CTM and GG is often used as an active substances to relieve symptoms of cough and cold. The concentration of CTM and GG in syrup are very low, so that it need validated determination method to ensure therapeutic dose. The purposes of this study were to validate determination method of CTM and GG and to apply the method to some syrups. Determination of CTM and GG in syrup using HPLC JascoLc-Net II/ADC equipped with a UV-Visible detector at a wavelength of 270 nm. The stationary phase used was C18Li Chosphera nd the mobile phase usedwas a mixture of acetonitrile:methanol:water (15:10:75 v/v) with a flow rate of 1 mL/minutes.Validation test was conducted on precision test, accuracy, selectivity, linearity and sensitivity. The method of analysis was applied to syrups fromthree different factories. The result of this research showed that validation tests of CTM and GG met the requirements, were: % RSD of precision test for CTM was 0.18% and for GG was 0.17%; accuracy test resulted good recovery for CTM and for GG in syrups. Good selectivity; linearity with a correlation coefficient 0.999; LOD for CTM and GG were 2.40 and 3.07 ”g/mL; LOQ for CTM and GG were 8.00”g/mL and 10.24 ”g/mL. The level of CTM and GG in syrups were compliance with the requirements by the Indonesian Pharmacopeia Edition V

    Assessment of Energy Storage Alternatives in the Puget Sound Energy System

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    As part of an ongoing study co-funded by the Bonneville Power Administration, under its Technology Innovation Grant Program, and the U.S. Department of Energy, the Pacific Northwest National Laboratory (PNNL) has developed an approach and modeling tool for assessing the net benefits of using energy storage located close to the customer in the distribution grid to manage demand. PNNL in collaboration with PSE and Primus Power has evaluated the net benefits of placing a zinc bromide battery system at two locations in the PSE system (Baker River / Rockport and Bainbridge Island). Energy storage can provide a number of benefits to the utility through the increased flexibility it provides to the grid system. Applications evaluated in the assessment include capacity value, balancing services, arbitrage, distribution deferral and outage mitigation. This report outlines the methodology developed for this study and Phase I results

    Individual Differences in Well-Being in Older Breast Cancer Survivors

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    Older women who survive breast cancer may differ significantly in their long-term well-being. Using a risk and protective factors model, we studied predictors of well-being in 127 women age 70 and above with a history of at least one year\u27s survival of breast cancer. Mean post-cancer survivorship was 5.1 years. Using life satisfaction, depression and general health perceptions as outcome variables, we assessed whether demographic variables, cancer-related variables, health status and psychosocial resources predicted variability in well-being using correlational and hierarchical regression analyses. Higher age predicted increased depression but was not associated with life satisfaction or general health perceptions. Cancer-related variables, including duration of survival, and type of cancer treatment, were not significantly associated with survivors\u27 well-being. Poorer health status was associated with poorer well-being in all three dependent variables. After controlling for demographics, cancer-related variables, and health status, higher levels of psychosocial resources including optimism, mastery, spirituality and social support predicted better outcome in all three dependent variables. While many older women survive breast cancer without severe sequelae, there is considerable variability in their well-being after survivorship. Successful intervention with older breast cancer survivors might include greater attention not only to cancer-specific concerns, but also attention to geriatric syndromes and functional impairment, and enhancement of protective psychosocial resources

    A Comparative Review of Electrolytes for Organic-Material-Based Energy-Storage Devices Employing Solid Electrodes and Redox Fluids

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    Electrolyte chemistry is critical for any energy‐storage device. Low‐cost and sustainable rechargeable batteries based on organic redox‐active materials are of great interest to tackle resource and performance limitations of current batteries with metal‐based active materials. Organic active materials can be used not only as solid electrodes in the classic lithium‐ion battery (LIB) setup, but also as redox fluids in redox‐flow batteries (RFBs). Accordingly, they have suitability for mobile and stationary applications, respectively. Herein, different types of electrolytes, recent advances for designing better performing electrolytes, and remaining scientific challenges are discussed and summarized. Due to different configurations and requirements between LIBs and RFBs, the similarities and differences for choosing suitable electrolytes are discussed. Both general and specific strategies for promoting the utilization of organic active materials are covered.So solid storage : The use of organic redox‐active materials is a new tendency for rechargeable batteries, either as traditional solid‐state electrode materials in lithium‐ion batteries or as dissolved redox fluidic species in liquid electrolytes for redox flow batteries. The performance‐limiting scenarios and some illuminating improvements by formulating electrolytes are reviewed
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