612 research outputs found

    Assessing Dysplasia of a Bronchial Biopsy with FTIR Spectroscopic Imaging

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    An FTIR image of an 8 µm section of de-paraffinised bronchial biopsy that shows a histological transition from normal to severe dysplasia/squamous cell carcinoma (SCC) insitu was obtained in transmission by stitching together images of 256 x 256 µm recorded using a 96 x 96 element FPA detector. Each pixel spectrum was calculated from 128 co-added interferograms at 4 cm−1 resolution. In order to improve the signal to noise ratio, blocks of 4x4 adjacent pixels were subsequently averaged. Analyses of this spectral image, after conversion of the spectra to their second derivatives, show that the epithelium and the lamina propria tissue types can be distinguished using the area of troughs at either 1591, 1334, 1275 or 1215 cm−1 or, more effectively, by separation into two groups by hierarchical clustering (HCA) of the 1614-1465 region. Due to an insufficient signal to noise ratio, disease stages within the image could not be distinguished with this extent of pixel averaging. However, after separation of the cell types, disease stages within either the epithelium or the lamina propria could be distinguished if spectra were averaged from larger, manually selected areas of the tissue. Both cell types reveal spectral differences that follow a transition from normal to cancerous histology. For example, spectral changes that occurred in the epithelium over the transition from normal to carcinoma insitu could be seen in the 1200-1000 cm−1 region, particularly as a decrease in the second derivative troughs at 1074 and 1036 cm−1 , consistent with changes in some form of carbohydrate. Spectral differences that indicate a disease transition from normal to carcinoma in the lamina propria could be seen in the 1350-1175 cm−1 and 1125-1030 cm−1 regions. Thus demonstrating that a progression from healthy to severe dysplasia/squamous cell carcinoma (SCC) insitu can be seen using FTIR spectroscopic imaging and multivariate analysis

    Physical and Electrical Performance of Vapor–Solid Grown ZnO Straight Nanowires

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    Physical and electrical properties of wurtzitic ZnO straight nanowires grown via a vapor–solid mechanism were investigated. Raman spectrum shows four first-order phonon frequencies and a second-order Raman frequency of the ZnO nanowires. Electrical and photoconductive performance of individual ZnO straight nanowire devices was studied. The results indicate that the nanowires reported here are n-type semi-conductors and UV light sensitive, and a desirable candidate for fabricating UV light nanosensors and other applications

    The HY5-PIF regulatory module coordinates light and temperature control of photosynthetic gene transcription

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    The ability to interpret daily and seasonal alterations in light and temperature signals is essential for plant survival. This is particularly important during seedling establishment when the phytochrome photoreceptors activate photosynthetic pigment production for photoautotrophic growth. Phytochromes accomplish this partly through the suppression of phytochrome interacting factors (PIFs), negative regulators of chlorophyll and carotenoid biosynthesis. While the bZIP transcription factor long hypocotyl 5 (HY5), a potent PIF antagonist, promotes photosynthetic pigment accumulation in response to light. Here we demonstrate that by directly targeting a common promoter cis-element (G-box), HY5 and PIFs form a dynamic activation-suppression transcriptional module responsive to light and temperature cues. This antagonistic regulatory module provides a simple, direct mechanism through which environmental change can redirect transcriptional control of genes required for photosynthesis and photoprotection. In the regulation of photopigment biosynthesis genes, HY5 and PIFs do not operate alone, but with the circadian clock. However, sudden changes in light or temperature conditions can trigger changes in HY5 and PIFs abundance that adjust the expression of common target genes to optimise photosynthetic performance and growth

    Agreement on Web-based Diagnoses and Severity of Mental Health Problems in Norwegian Child and Adolescent Mental Health Services

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    Objective: This study examined the agreement between diagnoses and severity ratings assigned by clinicians using a structured web-based interview within a child and adolescent mental health outpatient setting. Method: Information on 100 youths was obtained from multiple informants through a web-based Development and Well-Being Assessment (DAWBA). Based on this information, four experienced clinicians independently diagnosed (according to the International Classification of Diseases Revision 10) and rated the severity of mental health problems according to the Health of the Nation Outcome Scales for Children and Adolescents (HoNOSCA) and the Children’s Global Assessment Scale (C-GAS). Results: Agreement for diagnosis was κ=0.69-0.82. Intra-class correlation for single measures was 0.78 for HoNOSCA and 0.74 for C-GAS, and 0.93 and 0.92, respectively for average measures. Conclusions: Agreement was good to excellent for all diagnostic categories. Agreement for severity was moderate, but improved to substantial when the average of the ratings given by all clinicians was considered. Therefore, we conclude that experienced clinicians can assign reliable diagnoses and assess severity based on DAWBA data collected online

    The continuum of spreading depolarizations in acute cortical lesion development: Examining Leão's legacy.

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    A modern understanding of how cerebral cortical lesions develop after acute brain injury is based on Aristides Leão's historic discoveries of spreading depression and asphyxial/anoxic depolarization. Treated as separate entities for decades, we now appreciate that these events define a continuum of spreading mass depolarizations, a concept that is central to understanding their pathologic effects. Within minutes of acute severe ischemia, the onset of persistent depolarization triggers the breakdown of ion homeostasis and development of cytotoxic edema. These persistent changes are diagnosed as diffusion restriction in magnetic resonance imaging and define the ischemic core. In delayed lesion growth, transient spreading depolarizations arise spontaneously in the ischemic penumbra and induce further persistent depolarization and excitotoxic damage, progressively expanding the ischemic core. The causal role of these waves in lesion development has been proven by real-time monitoring of electrophysiology, blood flow, and cytotoxic edema. The spreading depolarization continuum further applies to other models of acute cortical lesions, suggesting that it is a universal principle of cortical lesion development. These pathophysiologic concepts establish a working hypothesis for translation to human disease, where complex patterns of depolarizations are observed in acute brain injury and appear to mediate and signal ongoing secondary damage

    Hyponatremia and hospital outcomes among patients with pneumonia: a retrospective cohort study

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    <p>Abstract</p> <p>Background</p> <p>Community-acquired (CAP) and nosocomial pneumonias contribute substantially to morbidity and hospital resource utilization. Hyponatremia, occurring in >1/4 of patients with CAP, is associated with greater disease severity and worsened outcomes.</p> <p>Methods</p> <p>To explore how hyponatremia is associated with outcomes in hospitalized patients with pneumonia, we analyzed a large administrative database with laboratory component from January 2004 to December 2005. Hyponatremia was defined as at least two [Na<sup>+</sup>] < 135 mEq/L within 24 hours of admission value.</p> <p>Results</p> <p>Of 7,965 patients with pneumonia, 649 (8.1%) with hyponatremia were older (72.4 ± 15.7 vs. 68.0 ± 22.0, p < 0.01), had a higher mean Deyo-Charlson Comorbidity Index Score (1.7 ± 1.7 vs. 1.6 ± 1.6, p = 0.02), and higher rates of ICU (10.0% vs. 6.3%, p < 0.001) and MV (3.9% vs. 2.3%, p = 0.01) in the first 48 hours of hospitalization than patients with normal sodium. Hyponatremia was associated with an increased ICU (6.3 ± 5.6 vs. 5.3 ± 5.1 days, p = 0.07) and hospital lengths of stay (LOS, 7.6 ± 5.3 vs. 7.0 ± 5.2 days, p < 0.001) and a trend toward increased hospital mortality (5.4% vs. 4.0%, p = 0.1). After adjusting for confounders, hyponatremia was associated with an increased risk of ICU (OR 1.58, 95% CI 1.20–2.08), MV (OR 1.75 95% CI 1.13–2.69), and hospital death (OR 1.3, 95% CI 0.90–1.87) and with increases of 0.8 day to ICU and 0.3 day to hospital LOS, and over $1,300 to total hospital costs.</p> <p>Conclusion</p> <p>Hyponatremia is common among hospitalized patients with pneumonia and is associated with worsened clinical and economic outcomes. Studies in this large population are needed to explore whether prompt correction of [Na<sup>+</sup>] may impact these outcomes.</p

    Market structure and hospital–insurer bargaining in the Netherlands

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    In 2005, competition was introduced in part of the hospital market in the Netherlands. Using a unique dataset of transactions and list prices between hospitals and insurers in the years 2005 and 2006, we estimate the influence of buyer and seller concentration on the negotiated prices. First, we use a traditional structure–conduct–performance model (SCP-model) along the lines of Melnick et al. (J Health Econ 11(3): 217–233, 1992) to estimate the effects of buyer and seller concentration on price–cost margins. Second, we model the interaction between hospitals and insurers in the context of a generalized bargaining model similar to Brooks et al. (J Health Econ 16: 417–434, 1997). In the SCP-model, we find that the market shares of hospitals (insurers) have a significantly positive (negative) impact on the hospital price–cost margin. In the bargaining model, we find a significant negative effect of insurer concentration, but no significant effect of hospital concentration. In both models, we find a significant impact of idiosyncratic effects on the market outcomes. This is consistent with the fact that the Dutch hospital sector is not yet in a long-run equilibrium

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

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    SummaryBackground The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding Bill & Melinda Gates Foundation

    Fall risk in an active elderly population – can it be assessed?

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    BACKGROUND: Falls amongst elderly people are often associated with fractures. Training of balance and physical performance can reduce fall risk; however, it remains a challenge to identify individuals at increased risk of falling to whom this training should be offered. It is believed that fall risk can be assessed by testing balance performance. In this study a test battery of physiological parameters related to balance and falls was designed to address fall risk in a community dwelling elderly population. RESULTS: Ninety-four elderly males and females between 70 and 80 years of age were included in a one year follow-up study. A fall incidence of 15% was reported. The test battery scores were not different between the fallers and non-fallers. Test scores were, however, related to self-reported health. In spite of inclusion of dynamic tests, the test battery had low fall prediction rates, with a sensitivity and specificity of 50% and 43% respectively. CONCLUSION: Individuals with poor balance were identified but falls were not predicted by this test battery. Physiological balance characteristics can apparently not be used in isolation as adequate indicators of fall risk in this population of community dwelling elderly. Falling is a complex phenomenon of multifactorial origin. The crucial factor in relation to fall risk is the redundancy of balance capacity against the balance demands of the individuals levels of fall-risky lifestyle and behavior. This calls for an approach to fall risk assessment in which the physiological performance is evaluated in relation to the activity profile of the individual
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