2,279 research outputs found

    Contemporary hormone therapy with LHRH agonists for prostate cancer: avoiding osteoporosis and fracture.

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    © 2015 Polish Urological Association. All Rights Reserved.Introduction Prostate cancer is a large clinical burden across Europe. It is, in fact, the most common cancer in males, accounting for more than 92,300 deaths annually throughout the continent. Prostate cancer is androgen-sensitive; thus an androgen deprivation therapy (ADT) is often used for treatment by reducing androgen to castrate levels. Several ADT agents have achieved benefits with effective palliation, but, unfortunately, severe adverse events are frequent. Contemporary ADT (Luteinising Hormone Releasing Hormone agonist - LHRHa injections) can result in side effects that include osteoporosis and fractures, compromising quality of life and survival.  Methods In this review we analysed the associated bone toxicity consequent upon contemporary ADT and based on the literature and our own experience we present future perspectives that seek to mitigate this associated toxicity both by development of novel therapies and by better identification and prediction of fracture risk. Results Preliminary results indicate that parenteral oestrogen can mitigate associated osteoporotic risk and that CT scans could provide a more accurate indicator of overall bone quality and hence fracture risk.  Conclusions As healthcare costs increase globally, cheap and effective alternatives that achieve ADT, but mitigate or avoid such bone toxicities, will be needed. More so, innovative techniques to improve both the measurement and the extent of this toxicity, by assessing bone health and prediction of fracture risk, are also required

    Quantifying water diffusion in high-viscosity and glassy aqueous solutions using a Raman isotope tracer method

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    Recent research suggests that under certain temperature and relative humidity conditions atmospheric aerosol may be present in the form of a glassy solid. In order to understand the impacts that this may have on aerosol–cloud interactions and atmospheric chemistry, knowledge of water diffusion within such aerosol particles is required. Here, a method is described in which Raman spectroscopy is used to observe D2O diffusion in high-viscosity aqueous solutions, enabling a quantitative assessment of water diffusion coefficients, Dwater, as a function of relative humidity. Results for sucrose solutions compare well with literature data at 23.5 ± 0.3 °C, and demonstrate that water diffusion is slow (Dwater ~5 × 10−17 m2 s−1), but not arrested, just below the glass transition at a water activity of 0.2. Room temperature water diffusion coefficients are also presented for aqueous levoglucosan and an aqueous mixture of raffinose, dicarboxylic acids and ammonium sulphate: at low humidity, diffusion is retarded but still occurs on millisecond to second timescales in atmospherically relevant-sized particles. The effect of gel formation on diffusion in magnesium sulfate solutions is shown to be markedly different from the gradual decrease in diffusion coefficients of highly viscous liquids. We show that using the Stokes–Einstein equation to determine diffusion timescales from viscosity leads to values which are more than 5 orders of magnitude too big, which emphasises the need to make measurements of diffusion coefficients. In addition, comparison of bounce fraction data for levoglucosan with measured diffusion data reveals that even when particles bounce the diffusion timescales for water are a fraction of a second for a 100 nm particle. This suggests a high bounce fraction does not necessarily indicate retarded water diffusion

    Ice nucleation by fertile soil dusts: Relative importance of mineral and biogenic components

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    Agricultural dust emissions have been estimated to contribute around 20% to the global dust burden. In contrast to dusts from arid source regions, the ice-nucleating abilities of which have been relatively well studied, soil dusts from fertile sources often contain a substantial fraction of organic matter. Using an experimental methodology which is sensitive to a wide range of ice nucleation efficiencies, we have characterised the immersion mode ice-nucleating activities of dusts (d<11 μ m) extracted from fertile soils collected at four locations around England. By controlling droplet sizes, which ranged in volume from 10 to 10 L (concentration=0.02 to 0.1 wt% dust), we have been able to determine the ice nucleation behaviour of soil dust particles at temperatures ranging from 267K (-6°C) down to the homogeneous limit of freezing at about 237K (-36°C). At temperatures above 258K (-15°C) we find that the ice-nucleating activity of soil dusts is diminished by heat treatment or digestion with hydrogen peroxide, suggesting that a major fraction of the ice nuclei stems from biogenic components in the soil. However, below 258 K, we find that the ice active site densities tend towards those expected from the mineral components in the soils, suggesting that the inorganic fraction of soil dusts, in particular the K-feldspar fraction, becomes increasingly important in the initiation of the ice phase at lower temperatures. We conclude that dusts from agricultural activities could contribute significantly to atmospheric IN concentrations, if such dusts exhibit similar activities to those observed in the current laboratory study

    Water diffusion in atmospherically relevant α-pinene secondary organic material

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    Secondary organic material (SOM) constitutes a large mass fraction of atmospheric aerosol particles. Understanding its impact on climate and air quality relies on accurate models of interactions with water vapour. Recent research shows that SOM can be highly viscous and can even behave mechanically like a solid, leading to suggestions that particles exist out of equilibrium with water vapour in the atmosphere. In order to quantify any kinetic limitation we need to know water diffusion coefficients for SOM, but this quantity has, until now, only been estimated and has not yet been measured. We have directly measured water diffusion coefficients in the water soluble fraction of α-pinene SOM between 240 and 280 K. Here we show that, although this material can behave mechanically like a solid, at 280 K water diffusion is not kinetically limited on timescales of 1 s for atmospheric-sized particles. However, diffusion slows as temperature decreases. We use our measured data to constrain a Vignes-type parameterisation, which we extend to lower temperatures to show that SOM can take hours to equilibrate with water vapour under very cold conditions. Our modelling for 100 nm particles predicts that under mid to upper tropospheric conditions radial inhomogeneities in water content produce a low viscosity surface region and more solid interior, with implications for heterogeneous chemistry and ice nucleation

    Clinical Psychologists’ Firearm Risk Management Perceptions and Practices

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    The purpose of this study was to investigate the current perceptions and practices of discussing firearm risk management with patients diagnosed with selected mental health problems. A three-wave survey was mailed to a national random sample of clinical psychologists and 339 responded (62%). The majority (78.5%) believed firearm safety issues were greater among those with mental health problems. However, the majority of clinical psychologists did not have a routine system for identifying patients with access to firearms (78.2%). Additionally, the majority (78.8%) reported they did not routinely chart or keep a record of whether patients owned or had access to firearms. About one-half (51.6%) of the clinical psychologists reported they would initiate firearm safety counseling if the patients were assessed as at risk for self-harm or harm to others. Almost half (46%) of clinical psychologists reported not receiving any information on firearm safety issues. Thus, the findings of this study suggest that a more formal role regarding anticipatory guidance on firearms is needed in the professional training of clinical psychologists

    Hot Streaks in Artistic, Cultural, and Scientific Careers

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    The hot streak, loosely defined as winning begets more winnings, highlights a specific period during which an individual's performance is substantially higher than her typical performance. While widely debated in sports, gambling, and financial markets over the past several decades, little is known if hot streaks apply to individual careers. Here, building on rich literature on lifecycle of creativity, we collected large-scale career histories of individual artists, movie directors and scientists, tracing the artworks, movies, and scientific publications they produced. We find that, across all three domains, hit works within a career show a high degree of temporal regularity, each career being characterized by bursts of high-impact works occurring in sequence. We demonstrate that these observations can be explained by a simple hot-streak model we developed, allowing us to probe quantitatively the hot streak phenomenon governing individual careers, which we find to be remarkably universal across diverse domains we analyzed: The hot streaks are ubiquitous yet unique across different careers. While the vast majority of individuals have at least one hot streak, hot streaks are most likely to occur only once. The hot streak emerges randomly within an individual's sequence of works, is temporally localized, and is unassociated with any detectable change in productivity. We show that, since works produced during hot streaks garner significantly more impact, the uncovered hot streaks fundamentally drives the collective impact of an individual, ignoring which leads us to systematically over- or under-estimate the future impact of a career. These results not only deepen our quantitative understanding of patterns governing individual ingenuity and success, they may also have implications for decisions and policies involving predicting and nurturing individuals with lasting impact

    Properties of small molecular drug loading and diffusion in a fluorinated PEG hydrogel studied by ^1H molecular diffusion NMR and ^(19)F spin diffusion NMR

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    R_f-PEG (fluoroalkyl double-ended poly(ethylene glycol)) hydrogel is potentially useful as a drug delivery depot due to its advanced properties of sol–gel two-phase coexistence and low surface erosion. In this study, ^1H molecular diffusion nuclear magnetic resonance (NMR) and ^(19)F spin diffusion NMR were used to probe the drug loading and diffusion properties of the R_f-PEG hydrogel for small anticancer drugs, 5-fluorouracil (FU) and its hydrophobic analog, 1,3-dimethyl-5-fluorouracil (DMFU). It was found that FU has a larger apparent diffusion coefficient than that of DMFU, and the diffusion of the latter was more hindered. The result of ^(19)F spin diffusion NMR for the corresponding freeze-dried samples indicates that a larger portion of DMFU resided in the R_f core/IPDU intermediate-layer region (where IPDU refers to isophorone diurethane, as a linker to interconnect the R_f group and the PEG chain) than that of FU while the opposite is true in the PEG–water phase. To understand the experimental data, a diffusion model was proposed to include: (1) hindered diffusion of the drug molecules in the R_f core/IPDU-intermediate-layer region; (2) relatively free diffusion of the drug molecules in the PEG-water phase (or region); and (3) diffusive exchange of the probe molecules between the above two regions. This study also shows that molecular diffusion NMR combined with spin diffusion NMR is useful in studying the drug loading and diffusion properties in hydrogels for the purpose of drug delivery applications

    Estimating the Total Number of Susceptibility Variants Underlying Complex Diseases from Genome-Wide Association Studies

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    Recently genome-wide association studies (GWAS) have identified numerous susceptibility variants for complex diseases. In this study we proposed several approaches to estimate the total number of variants underlying these diseases. We assume that the variance explained by genetic markers (Vg) follow an exponential distribution, which is justified by previous studies on theories of adaptation. Our aim is to fit the observed distribution of Vg from GWAS to its theoretical distribution. The number of variants is obtained by the heritability divided by the estimated mean of the exponential distribution. In practice, due to limited sample sizes, there is insufficient power to detect variants with small effects. Therefore the power was taken into account in fitting. Besides considering the most significant variants, we also tried to relax the significance threshold, allowing more markers to be fitted. The effects of false positive variants were removed by considering the local false discovery rates. In addition, we developed an alternative approach by directly fitting the z-statistics from GWAS to its theoretical distribution. In all cases, the “winner's curse” effect was corrected analytically. Confidence intervals were also derived. Simulations were performed to compare and verify the performance of different estimators (which incorporates various means of winner's curse correction) and the coverage of the proposed analytic confidence intervals. Our methodology only requires summary statistics and is able to handle both binary and continuous traits. Finally we applied the methods to a few real disease examples (lipid traits, type 2 diabetes and Crohn's disease) and estimated that hundreds to nearly a thousand variants underlie these traits

    Radiological Decision Aid to determine suitability for medial unicompartmental knee arthroplasty: development and preliminary validation

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    Aims: An evidence-based radiographic Decision Aid for meniscal-bearing unicompartmental knee arthroplasty (UKA) has been developed and this study investigates its performance at an independent centre. Patients: and Methods Pre-operative radiographs, including stress views, from a consecutive cohort of 550 knees undergoing arthroplasty (UKA or total knee arthroplasty; TKA) by a single-surgeon were assessed. Suitability for UKA was determined using the Decision Aid, with the assessor blinded to treatment received, and compared with actual treatment received, which was determined by an experienced UKA surgeon based on history, examination, radiographic assessment including stress radiographs, and intra-operative assessment in line with the recommended indications as described in the literature. Results: The sensitivity and specificity of the Decision Aid was 92% and 88%, respectively. Excluding knees where a clear pre-operative plan was made to perform TKA, i.e. patient request, the sensitivity was 93% and specificity 96%. The false-positive rate was low (2.4%) with all affected patients readily identifiable during joint inspection at surgery. In patients meeting Decision Aid criteria and receiving UKA, the five-year survival was 99% (95% confidence intervals (CI) 97 to 100). The false negatives (3.5%), who received UKA but did not meet the criteria, had significantly worse functional outcomes (flexion p < 0.001, American Knee Society Score - Functional p < 0.001, University of California Los Angeles score p = 0.04), and lower implant survival of 93.1% (95% CI 77.6 to 100). Conclusion: The radiographic Decision Aid safely and reliably identifies appropriate patients for meniscal-bearing UKA and achieves good results in this population. The widespread use of the Decision Aid should improve the results of UKA

    Multiple lung abscesses due to acinetobacter infection: a case report

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    Acinetobacter species are well-known causes of nosocomial infections. Recent increasing evidence emphasize on the role of these pathogens in community-acquired infections
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