78 research outputs found

    Adaptogenic and nootropic activities of aqueous extract of Vitis vinifera (grape seed): an experimental study in rat model

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    BACKGROUND: The aerial parts of Vitis vinifera (common grape or European grape) have been widely used in Ayurveda to treat a variety of common and stress related disorders. In the present investigation, the seed extract of V. vinifera was evaluated for antistress activity in normal and stress induced rats. Furthermore, the extract was studied for nootropic activity in rats and in-vitro antioxidant potential to correlate its antistress activity. METHODS: For the evaluation of antistress activity, groups of rats (n = 6) were subjected to forced swim stress one hour after daily treatment of V. vinifera extract. Urinary vanillylmandelic acid (VMA) and ascorbic acid were selected as non-invasive biomarkers to assess the antistress activity. The 24 h urinary excretion of vanillylmandelic acid (VMA) and ascorbic acid were determined by spectrophotometric methods in all groups under normal and stressed conditions. The nootropic activity of the extract as determined from acquisition, retention and retrieval in rats was studied by conditioned avoidance response using Cook's pole climbing apparatus. The in vitro antioxidant activity was determined based on the ability of V. vinifera to scavenge hydroxyl radicals. RESULTS: Daily administration of V. vinifera at doses of 100, 200 and 300 mg/kg body weight one hour prior to induction of stress inhibited the stress induced urinary biochemical changes in a dose dependent manner. However, no change in the urinary excretion of VMA and ascorbic acid was observed in normal animals at all the doses studied. The cognition, as determined by the acquisition, retention and recovery in rats was observed to be dose dependent. The extract also produced significant inhibition of hydroxyl radicals in comparison to ascorbic acid in a dose dependent manner. CONCLUSION: The present study provides scientific support for the antistress (adaptogenic), antioxidant and nootropic activities of V. vinifera seed extract and substantiate the traditional claims for the usage of grape fruits and seeds in stress induced disorders

    Differential cross sections and spin density matrix elements for the reaction gamma p -> p omega

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    High-statistics differential cross sections and spin density matrix elements for the reaction gamma p -> p omega have been measured using the CLAS at Jefferson Lab for center-of-mass (CM) energies from threshold up to 2.84 GeV. Results are reported in 112 10-MeV wide CM energy bins, each subdivided into cos(theta_CM) bins of width 0.1. These are the most precise and extensive omega photoproduction measurements to date. A number of prominent structures are clearly present in the data. Many of these have not previously been observed due to limited statistics in earlier measurements

    The Telomere Binding Protein TRF2 Induces Chromatin Compaction

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    Mammalian telomeres are specialized chromatin structures that require the telomere binding protein, TRF2, for maintaining chromosome stability. In addition to its ability to modulate DNA repair activities, TRF2 also has direct effects on DNA structure and topology. Given that mammalian telomeric chromatin includes nucleosomes, we investigated the effect of this protein on chromatin structure. TRF2 bound to reconstituted telomeric nucleosomal fibers through both its basic N-terminus and its C-terminal DNA binding domain. Analytical agarose gel electrophoresis (AAGE) studies showed that TRF2 promoted the folding of nucleosomal arrays into more compact structures by neutralizing negative surface charge. A construct containing the N-terminal and TRFH domains together altered the charge and radius of nucleosomal arrays similarly to full-length TRF2 suggesting that TRF2-driven changes in global chromatin structure were largely due to these regions. However, the most compact chromatin structures were induced by the isolated basic N-terminal region, as judged by both AAGE and atomic force microscopy. Although the N-terminal region condensed nucleosomal array fibers, the TRFH domain, known to alter DNA topology, was required for stimulation of a strand invasion-like reaction with nucleosomal arrays. Optimal strand invasion also required the C-terminal DNA binding domain. Furthermore, the reaction was not stimulated on linear histone-free DNA. Our data suggest that nucleosomal chromatin has the ability to facilitate this activity of TRF2 which is thought to be involved in stabilizing looped telomere structures

    A chemical survey of exoplanets with ARIEL

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    Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio

    The relation between neuromechanical parameters and Ashworth score in stroke patients

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    Quantifying increased joint resistance into its contributing factors i.e. stiffness and viscosity ("hypertonia") and stretch reflexes ("hyperreflexia") is important in stroke rehabilitation. Existing clinical tests, such as the Ashworth Score, do not permit discrimination between underlying tissue and reflexive (neural) properties. We propose an instrumented identification paradigm for early and tailor made interventions.BioMechanical EngineeringMechanical, Maritime and Materials Engineerin

    Drosophila Carrying Pex3 or Pex16 Mutations Are Models of Zellweger Syndrome That Reflect Its Symptoms Associated with the Absence of Peroxisomes

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    The peroxisome biogenesis disorders (PBDs) are currently difficult-to-treat multiple-organ dysfunction disorders that result from the defective biogenesis of peroxisomes. Genes encoding Peroxins, which are required for peroxisome biogenesis or functions, are known causative genes of PBDs. The human peroxin genes PEX3 or PEX16 are required for peroxisomal membrane protein targeting, and their mutations cause Zellweger syndrome, a class of PBDs. Lack of understanding about the pathogenesis of Zellweger syndrome has hindered the development of effective treatments. Here, we developed potential Drosophila models for Zellweger syndrome, in which the Drosophila pex3 or pex16 gene was disrupted. As found in Zellweger syndrome patients, peroxisomes were not observed in the homozygous Drosophila pex3 mutant, which was larval lethal. However, the pex16 homozygote lacking its maternal contribution was viable and still maintained a small number of peroxisome-like granules, even though PEX16 is essential for the biosynthesis of peroxisomes in humans. These results suggest that the requirements for pex3 and pex16 in peroxisome biosynthesis in Drosophila are different, and the role of PEX16 orthologs may have diverged between mammals and Drosophila. The phenotypes of our Zellweger syndrome model flies, such as larval lethality in pex3, and reduced size, shortened longevity, locomotion defects, and abnormal lipid metabolisms in pex16, were reminiscent of symptoms of this disorder, although the Drosophila pex16 mutant does not recapitulate the infant death of Zellweger syndrome. Furthermore, pex16 mutants showed male-specific sterility that resulted from the arrest of spermatocyte maturation. pex16 expressed in somatic cyst cells but not germline cells had an essential role in the maturation of male germline cells, suggesting that peroxisome-dependent signals in somatic cyst cells could contribute to the progression of male germ-cell maturation. These potential Drosophila models for Zellweger syndrome should contribute to our understanding of its pathology

    Diagnostic value of fine-needle aspiration biopsy for breast mass: a systematic review and meta-analysis

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    <p>Abstract</p> <p>Background</p> <p>Fine-needle aspiration biopsy (FNAB) of the breast is a minimally invasive yet maximally diagnostic method. However, the clinical use of FNAB has been questioned. The purpose of our study was to establish the overall value of FNAC in the diagnosis of breast lesions.</p> <p>Methods</p> <p>After a review and quality assessment of 46 studies, sensitivity, specificity and other measures of accuracy of FNAB for evaluating breast lesions were pooled using random-effects models. Summary receiver operating characteristic curves were used to summarize overall accuracy. The sensitivity and specificity for the studies data (included unsatisfactory samples) and underestimation rate of unsatisfactory samples were also calculated.</p> <p>Results</p> <p>The summary estimates for FNAB in diagnosis of breast carcinoma were as follows (unsatisfactory samples was temporarily exluded): sensitivity, 0.927 (95% confidence interval [CI], 0.921 to 0.933); specificity, 0.948 (95% CI, 0.943 to 0.952); positive likelihood ratio, 25.72 (95% CI, 17.35 to 28.13); negative likelihood ratio, 0.08 (95% CI, 0.06 to 0.11); diagnostic odds ratio, 429.73 (95% CI, 241.75 to 763.87); The pooled sensitivity and specificity for 11 studies, which reported unsatisfactory samples (unsatisfactory samples was considered to be positive in this classification) were 0.920 (95% CI, 0.906 to 0.933) and 0.768 (95% CI, 0.751 to 0.784) respectively. The pooled proportion of unsatisfactory samples that were subsequently upgraded to various grade cancers was 27.5% (95% CI, 0.221 to 0.296).</p> <p>Conclusions</p> <p>FNAB is an accurate biopsy for evaluating breast malignancy if rigorous criteria are used. With regard to unsatisfactory samples, futher invasive procedures are required in order to minimize the chance of a missed diagnosis of breast cancer.</p

    The extraction of ϕN\phi-N total cross section from d(γ,pK+K)nd(\gamma,pK^{+}K^{-})n

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    We report on the first measurement of the differential cross section of ϕ\phi-meson photoproduction for the d(γ,pK+K)nd(\gamma,pK^{+}K^{-})n exclusive reaction channel. The experiment was performed using a \textcolor{black}{tagged-photon} beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. A combined analysis using data from the d(γ,pK+K)nd(\gamma,pK^{+}K^{-})n channel and those from a previous publication on coherent ϕ\phi production on the deuteron has been carried out to extract the ϕN\phi-N total cross section, σϕN\sigma_{\phi N}. The extracted ϕN\phi-N total cross section favors a value above 20 mb. This value is larger than the value extracted using vector-meson dominance models for ϕ\phi photoproduction on the proton.Comment: 7 pages 4 figure
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