967 research outputs found

    Antiurolithic activity of Origanum vulgare is mediated through multiple pathways

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    <p>Abstract</p> <p>Background</p> <p><it>Origanum vulgare </it>Linn has traditionally been used in the treatment of urolithiasis. Therefore, we investigated the crude extract of <it>Origanum vulgare </it>for possible antiurolithic effect, to rationalize its medicinal use.</p> <p>Methods</p> <p>The crude aqueous-methanolic extract of <it>Origanum vulgare </it>(Ov.Cr) was studied using the <it>in vitro </it>and <it>in vivo </it>methods. In the <it>in vitro </it>experiments, supersaturated solution of calcium and oxalate, kidney epithelial cell lines (MDCK) and urinary bladder of rabbits were used, whereas, in the <it>in vivo </it>studies, rat model of urolithiasis was used for the study of preventive and curative effect.</p> <p>Results</p> <p>In the <it>in vitro </it>experiments, Ov.Cr exhibited a concentration-dependent (0.25-4 mg/ml) inhibitory effect on the slope of nucleation and aggregation and also decreased the number of calcium oxalate monohydrate crystals (COM) produced in calcium oxalate metastable solutions. It also showed concentration-dependent antioxidant effect against DPPH free radical and lipid peroxidation induced in rat kidney tissue homogenate. Ov.Cr reduced the cell toxicity using MTT assay and LDH release in renal epithelial cells (MDCK) exposed to oxalate (0.5 mM) and COM (66 Îźg/cm<sup>2</sup>) crystals. Ov.Cr relaxed high K<sup>+ </sup>(80 mM) induced contraction in rabbit urinary bladder strips, and shifted the calcium concentration-response curves (CRCs) towards right with suppression of the maximum response similar to that of verapamil, a standard calcium channel blocker. In male Wistar rats receiving lithogenic treatment comprising of 0.75% ethylene glycol in drinking water given for 3 weeks along with ammonium chloride (NH<sub>4</sub>Cl) for the first 5 days, Ov.Cr treatment (10-30 mg/kg) prevented as well as reversed toxic changes including loss of body weight, polyurea, crystalluria, oxaluria, raised serum urea and creatinine levels and crystal deposition in kidneys compared to their respective controls.</p> <p>Conclusion</p> <p>These data indicating the antiurolithic activity in Ov.Cr, possibly mediated through inhibition of CaOx crystallization, antioxidant, renal epithelial cell protective and antispasmodic activities, rationalizes its medicinal use in urolithiasis.</p

    Desperately seeking fixedness: practitioners accounts of 'becoming doctoral researchers

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    We draw upon the concept of liminality to explore the experiences of practitioners enrolled on a UK Doctor of Business Administration (DBA) programme. We analyse twenty practitioners’ reflective journals to detail how the DBA liminal space was negotiated. More specifically, we describe how practitioners deal with their struggles of identity incoherence or ‘monsters of doubt’ which are amplified in the DBA context owing to the complex nature of the separation phase of liminality. We identify three broad methods deployed in this endeavour: ‘scaffolding’; ‘putting the past to work’ and ‘bracketing’- which evidence practitioners ‘desperately seeking fixedness’. We make three contributions – first, we provide empirical insights into the experiences of the increasingly significant, but still under researched, DBA student. Second, we develop our understandings of monsters of doubt through illustrating how these are negotiated for learning to progress. Finally, we contribute to wider discussions of ‘becoming’ to demonstrate the simultaneous and paradoxical importance of movement and fixedness in order to learn and become

    Cellular Imaging Of The Tapetal-like Reflex In Carriers Of RPGR-associated Retinopathy

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    PURPOSE: To examine the features of the tapetal-like reflex (TLR) in female carriers of RPGR-associated retinopathy by means of adaptive optics scanning light ophthalmoscopy (AOSLO) and spectral domain optical coherence tomography. METHODS: Nine molecularly confirmed RPGR carriers and three healthy controls underwent ocular examination and the following retinal imaging modalities: color photography, near-infrared reflectance, fundus autofluorescence, spectral domain optical coherence tomography, and AOSLO. After identifying TLR areas across all imaging modalities, normalized local contrast of outer retinal bands on spectral domain optical coherence tomography was calculated and AOSLO-acquired photoreceptor mosaic analysis was performed. RESULTS: Seven carriers had TLR areas, which colocalized with increased rod photoreceptor reflectivity on confocal AOSLO and reduced cone photoreceptor densities. Parafoveal TLR areas also exhibited reduced local contrast (i.e., increased reflectivity) of the outer retinal bands on spectral domain optical coherence tomography (inner segment ellipsoid zone and outer segment interdigitation zone). Healthy controls did not show TLR. CONCLUSION: The cellular resolution provided by AOSLO affords the characterization of the photoreceptor mosaic in RPGR carriers with a TLR. Features revealed include reduced cone densities, increased cone inner segment diameters, and increased rod outer segment reflectivity

    Medical students’ and doctors’ attitudes towards older patients and their care in hospital settings: a conceptualisation

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    Background: despite assertions in reports from governmental and charitable bodies that negative staff attitudes towards older patients may contribute to inequitable healthcare provision for older patients when compared with younger patients (those aged under 65 years), the research literature does not describe these attitudes in any detail. Objective: this study explored and conceptualised attitudes towards older patients using in-depth interviews. Methods: twenty-five semi-structured interviews with medical students and hospital-based doctors in a UK acute teaching hospital were conducted. Participants were asked about their beliefs, emotions and behavioural tendencies towards older patients, in line with the psychological literature on the definition of attitudes (affective, cognitive and behavioural information). Data were analysed thematically. Results: attitudes towards older patients and their care could be conceptualised under the headings: (i) beliefs about older patients; (ii) older patients’ unique needs and the skills required to care for them and (iii) emotions and satisfaction with caring for older patients. Conclusions: our findings outlined common beliefs and stereotypes specific to older patients, as opposed to older people in general. Older patients had unique needs concerning their healthcare. Participants typically described negative emotions about caring for older patients, but the sources of dissatisfaction largely related to the organisational setting and system in which the care is delivered to these patients. This study marks one of the first in-depth attempts to explore attitudes towards older patients in UK hospital settings

    Understanding the atmospheric properties and chemical composition of the ultra-hot Jupiter HAT-P-7b II. Mapping the effects of gas kinetics

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    Funding: Part of this work was supported by the German Deutsche Forschungsgemeinschaft, DFG project number Ts 17/2–1.Aims. The atmospheres of ultra-hot Jupiters (UHJs) are commonly considered to be at thermochemical equilibrium. We aim to provide disequilibrium chemistry maps for a global understanding of the chemistry in the atmosphere of HAT-P-7b and assess the importance of disequilibrium chemistry on UHJs. Methods. We applied a hierarchical modeling approach using 97 1D atmospheric profiles from a 3D general circulation model of HAT-P-7b. For each atmospheric 1D profile, we evaluated our kinetic cloud formation model consistently with the local gas-phase composition in chemical equilibrium. This served as input to study the quenching of dominating CHNO-binding molecules. We evaluated quenching results from a zeroth-order approximation in comparison to a kinetic gas-phase approach. Results. We find that the zeroth-order approach of estimating quenching points agrees well with the full gas-kinetic modeling results. However, it underestimates the quenching levels by about one order of magnitude at high temperatures. Chemical disequilibrium has the greatest effect on the nightside and morning abundance of species such as H, H2O, CH4, CO2, HCN, and all CnHm molecules; heavier CnHm molecules are more affected by disequilibrium processes. The CO abundance, however, is affected only marginally. While dayside abundances also notably change, those around the evening terminator of HAT-P-7b are the least affected by disequilibrium processes. The latter finding may partially explain the consistency of observed transmission spectra of UHJs with atmospheres in thermochemical equilibrium. Photochemistry only negligibly affects molecular abundances and quenching levels. Conclusions. In general, the quenching points of the atmosphere of HAT-P-7b are at much lower pressures than in the cooler hot-jupiters. We propose several avenues to determining the effect of disequilibrium processes on UHJs that are in general based on abundance and opacity measurements at different local times. It remains a challenge to completely disentangle this from the chemical effects of clouds and that of a primordial nonsolar abundance.Publisher PDFPeer reviewe

    Mapping Children's Discussions of Evidence in Science to Assess Collaboration and Argumentation

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    The research reported in this paper concerns the development of children's skills of interpreting and evaluating evidence in science. Previous studies have shown that school teaching often places limited emphasis on the development of these skills, which are necessary for children to engage in scientific debate and decision-making. The research, undertaken in the UK, involved four collaborative decision-making activities to stimulate group discussion, each was carried out with five groups of four children (10-11 years old). The research shows how the children evaluated evidence for possible choices and judged whether their evidence was sufficient to support a particular conclusion or the rejection of alternative conclusions. A mapping technique was developed to analyse the discussions and identify different "levels" of argumentation. The authors conclude that suitable collaborative activities that focus on the discussion of evidence can be developed to exercise children's ability to argue effectively in making decisions

    Changes in medical student and Doctor attitudes toward older adults after an intervention: a systematic review

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    Research investigating the effects of attitude-focused interventions on doctors' and medical students' attitudes toward older adults has produced mixed results. The objective of this systematic review was to determine whether factors pertaining to study design and quality might provide some explanation of this inconclusive picture. Articles were judged of interest if they reported doctors' or medicals students' attitude scores before and after a geriatric-focused intervention. Articles that did not report the measure used, mean scores, or inferential statistics were excluded. Twenty-seven databases, including Medline, PsychInfo, and Embase, were searched through April 2011 using a systematic search strategy. After assessment and extraction, 27 studies met the eligibility criteria for this review. These studies demonstrated inconsistent results; 14 appeared successful in effecting positive attitude change toward older adults after an intervention, and 13 appeared unsuccessful. Attitude change results differed in line with the content of the intervention. Of the 27 studies, 11 interventions contained solely knowledge-building content. Three of these studies demonstrated positive changes in doctors' or medical students' attitudes toward older adults after the intervention. The remaining 16 interventions incorporated an empathy-building component, such as an aging simulation exercise or contact with a healthy older adult. Of these, 11 successfully demonstrated positive attitude change after the intervention. The inclusion of an empathy-building task in an intervention appears to be associated with positive attitude change in medical students' and doctors' attitudes toward older adults
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