1,122 research outputs found

    Overtone spectra and intensities of tetrahedral molecules in boson-realization models

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    The stretching and bending vibrational spectrum and the intensities of infrared transitions in a tetrahedral molecule are studied in two boson-realization models, where the interactions between stretching and bending vibrations are described by a quadratic cross term and by Fermi resonance terms, called harmonically coupled and Fermi resonance boson-realization model, respectively. The later is a development of our recent model. As an example, the two models are applied to the overtone spectrum and the intensities of silicon tetrafluorde. Those models provide fits to the published experimental vibrational eigenvalues with standard deviations 1.956 cm1^{-1} and 0.908 cm1^{-1}, respectively. The intensities of infrared transitions of its complete vibrations are calculated in the two models, and results show a good agreement with the observed data.Comment: 14 pages Revtex, no figure, to appear in Annals of Physic

    Fermi resonance-algebraic model for molecular vibrational spectra

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    A Fermi resonance-algebraic model is proposed for molecular vibrations, where a U(2) algebra is used for describing the vibrations of each bond, and Fermi resonances between stretching and bending modes are taken into account. The model for a bent molecule XY_2 and a molecule XY_3 is successfully applied to fit the recently observed vibrational spectrum of the water molecule and arsine (AsH_3), respectively, and results are compared with those of other models. Calculations show that algebraic approaches can be used as an effective method for describing molecular vibrations with small standard deviations

    DNA replication stress mediates APOBEC3 family mutagenesis in breast cancer

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    BACKGROUND: The APOBEC3 family of cytidine deaminases mutate the cancer genome in a range of cancer types. Although many studies have documented the downstream effects of APOBEC3 activity through next-generation sequencing, less is known about their upstream regulation. In this study, we sought to identify a molecular basis for APOBEC3 expression and activation. RESULTS: HER2 amplification and PTEN loss promote DNA replication stress and APOBEC3B activity in vitro and correlate with APOBEC3 mutagenesis in vivo. HER2-enriched breast carcinomas display evidence of elevated levels of replication stress-associated DNA damage in vivo. Chemical and cytotoxic induction of replication stress, through aphidicolin, gemcitabine, camptothecin or hydroxyurea exposure, activates transcription of APOBEC3B via an ATR/Chk1-dependent pathway in vitro. APOBEC3B activation can be attenuated through repression of oncogenic signalling, small molecule inhibition of receptor tyrosine kinase signalling and alleviation of replication stress through nucleoside supplementation. CONCLUSION: These data link oncogene, loss of tumour suppressor gene and drug-induced replication stress with APOBEC3B activity, providing new insights into how cytidine deaminase-induced mutagenesis might be activated in tumourigenesis and limited therapeutically

    Short-term efficacy of physical interventions in osteoarthritic knee pain. A systematic review and meta-analysis of randomised placebo-controlled trials.

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    BACKGROUND: Treatment efficacy of physical agents in osteoarthritis of the knee (OAK) pain has been largely unknown, and this systematic review was aimed at assessing their short-term efficacies for pain relief. METHODS: Systematic review with meta-analysis of efficacy within 1-4 weeks and at follow up at 1-12 weeks after the end of treatment. RESULTS: 36 randomised placebo-controlled trials (RCTs) were identified with 2434 patients where 1391 patients received active treatment. 33 trials satisfied three or more out of five methodological criteria (Jadad scale). The patient sample had a mean age of 65.1 years and mean baseline pain of 62.9 mm on a 100 mm visual analogue scale (VAS). Within 4 weeks of the commencement of treatment manual acupuncture, static magnets and ultrasound therapies did not offer statistically significant short-term pain relief over placebo. Pulsed electromagnetic fields offered a small reduction in pain of 6.9 mm [95% CI: 2.2 to 11.6] (n = 487). Transcutaneous electrical nerve stimulation (TENS, including interferential currents), electro-acupuncture (EA) and low level laser therapy (LLLT) offered clinically relevant pain relieving effects of 18.8 mm [95% CI: 9.6 to 28.1] (n = 414), 21.9 mm [95% CI: 17.3 to 26.5] (n = 73) and 17.7 mm [95% CI: 8.1 to 27.3] (n = 343) on VAS respectively versus placebo control. In a subgroup analysis of trials with assumed optimal doses, short-term efficacy increased to 22.2 mm [95% CI: 18.1 to 26.3] for TENS, and 24.2 mm [95% CI: 17.3 to 31.3] for LLLT on VAS. Follow-up data up to 12 weeks were sparse, but positive effects seemed to persist for at least 4 weeks after the course of LLLT, EA and TENS treatment was stopped. CONCLUSION: TENS, EA and LLLT administered with optimal doses in an intensive 2-4 week treatment regimen, seem to offer clinically relevant short-term pain relief for OAK

    Gene dispersion is the key determinant of the read count bias in differential expression analysis of RNA-seq data

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    Background: In differential expression analysis of RNA-sequencing (RNA-seq) read count data for two sample groups, it is known that highly expressed genes (or longer genes) are more likely to be differentially expressed which is called read count bias (or gene length bias). This bias had great effect on the downstream Gene Ontology over-representation analysis. However, such a bias has not been systematically analyzed for different replicate types of RNA-seq data. Results: We show that the dispersion coefficient of a gene in the negative binomial modeling of read counts is the critical determinant of the read count bias (and gene length bias) by mathematical inference and tests for a number of simulated and real RNA-seq datasets. We demonstrate that the read count bias is mostly confined to data with small gene dispersions (e.g., technical replicates and some of genetically identical replicates such as cell lines or inbred animals), and many biological replicate data from unrelated samples do not suffer from such a bias except for genes with some small counts. It is also shown that the sample-permuting GSEA method yields a considerable number of false positives caused by the read count bias, while the preranked method does not. Conclusion: We showed the small gene variance (similarly, dispersion) is the main cause of read count bias (and gene length bias) for the first time and analyzed the read count bias for different replicate types of RNA-seq data and its effect on gene-set enrichment analysis

    Oxy-fuel combustion of coal and biomass blends

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    The ignition temperature, burnout and NO emissions of blends of a semi-anthracite and a high-volatile bituminous coal with 10 and 20 wt.% of olive waste were studied under oxy-fuel combustion conditions in an entrained flow reactor (EFR). The results obtained under several oxy-fuel atmospheres (21%O2–79%CO2, 30%O2–70%CO2 and 35%O2–65%CO2) were compared with those attained in air. The results indicated that replacing N2 by CO2 in the combustion atmosphere with 21% of O2 caused an increase in the temperature of ignition and a decrease in the burnout value. When the O2 concentration was increased to 30 and 35%, the temperature of ignition was lower and the burnout value was higher than in air conditions. A significant reduction in ignition temperature and a slight increase in the burnout value was observed after the addition of biomass, this trend becoming more noticeable as the biomass concentration was increased. The emissions of NO during oxy-fuel combustion were lower than under air-firing. However, they remained similar under all the oxy-fuel atmospheres with increasing O2 concentrations. Emissions of NO were significantly reduced by the addition of biomass to the bituminous coal, although this effect was less noticeable in the case of the semi-anthracite.This work was carried out with financial support from the Spanish MICINN (Project PS-120000-2005-2) co-financed by the European Regional Development Fund. M.V.G. and L.A. acknowledge funding from the CSIC JAE-Doc and CSIC JAE-Pre programs, respectively, co-financed by the European Social Fund. J.R. acknowledges funding from the Government of the Principado de Asturias (Severo Ochoa program).Peer reviewe

    BounceBack™ capsules for reduction of DOMS after eccentric exercise: a randomized, double-blind, placebo-controlled, crossover pilot study

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    <p>Abstract</p> <p>Background</p> <p>Delayed onset muscle soreness (DOMS) is muscle pain and discomfort experienced approximately one to three days after exercise. DOMS is thought to be a result of microscopic muscle fiber tears that occur more commonly after eccentric exercise rather than concentric exercise. This study sought to test the efficacy of a proprietary dietary supplement, BounceBack™, to alleviate the severity of DOMS after standardized eccentric exercise.</p> <p>Methods</p> <p>The study was a randomized, double-blind, placebo-controlled, crossover study. Ten healthy community-dwelling untrained subjects, ranging in age from 18–45 years, were enrolled. Mean differences within and between groups were assessed inferentially at each data collection time-point using t-tests for all outcome measures.</p> <p>Results</p> <p>In this controlled pilot study, intake of BounceBack™ capsules for 30 days resulted in a significant reduction in standardized measures of pain and tenderness post-eccentric exercise compared to the placebo group. There were trends towards reductions in plasma indicators of inflammation (high sensitivity C-reactive protein) and muscle damage (creatine phosphokinase and myoglobin).</p> <p>Conclusion</p> <p>BounceBack™ capsules were able to significantly reduce standardized measures of pain and tenderness at several post-eccentric exercise time points in comparison to placebo. The differences in the serological markers of DOMS, while not statistically significant, appear to support the clinical findings. The product appears to have a good safety profile and further study with a larger sample size is warranted based on the current results.</p

    Enhanced Photoelectrochemical Detection of Bioaffinity Reactions by Vertically Oriented Au Nanobranches Complexed with a Biotinylated Polythiophene Derivative

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    Four nanostructured Au electrodes were prepared by a simple and templateless electrochemical deposition technique. After complexing with a biotinylated polythiophene derivative (PTBL), photocurrent generation and performance of PTBL/Au-nanostructured electrodes as photoelectrochemical biosensors were investigated. Among these four nanostructured Au electrodes, vertically oriented nanobranches on the electrode significantly improved the photoelectric conversion, because the vertically oriented nanostructures not only benefit light harvesting but also the transfer of the photogenerated charge carriers. Owing to this advantaged nanostructure, the PTBL/Au-nanobranch electrode showed higher sensitivity and faster response times in the photoelectrochemical detection of a streptavidin-biotin affinity reaction compared to a PTBL/Au-nanoparticle electrode

    Nutrient intake and bone health status of Korean male college students as related to smoking situations

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    The purpose of this study was to compare the dietary habits, nutrient intake, bone mineral density (BMD) and bone metabolism in Korean male collegians as related to smoking situation. One hundred sixty one young adult males at the age of 20-26 participated in this study. The subjects were divided into four groups: non smoker (n=42), light smoker (n=34), moderate smoker (n=49) and heavy smoker (n=36). The anthropometric characteristics, smoking situations, dietary habits and nutrient intakes were observed. Bone status of the calcaneus was measured by using quantitative ultrasound (QUS). Bone metabolism markers including serum alkaline phosphatase activity (ALP) and N-mid osteocalcin (OC) were analyzed. There were no significant differences in height, weight, BMI, energy and calcium intake among the four groups. Iron intake of moderate and heavy smoker was significantly lower than that of light smoker. Heavy smokers consumed significantly lower vitamin C than moderate smokers, and their coffee consumption and lifetime alcohol consumption were significantly highest among the 4 groups. QUS parameters and serum ALP were not significantly different among the four groups. Serum OC levels were significantly lower in heavy and non smoker group compared to the moderate smoker group. In conclusion, heavy smokers in young male collegians had undesirable lifestyle and dietary habits, like as high consumption of coffee and alcohol, and low intake of Fe and vitamin C. Although, there was no significant difference in their current bone status from the other groups, these undesirable factors with heavy smoking may affect their bone health in the long term
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