3,700 research outputs found

    Hepatocellular carcinoma: Review of disease and tumor biomarkers.

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    © The Author(s) 2016.Hepatocellular carcinoma (HCC) is a common malignancy and now the second commonest global cause of cancer death. HCC tumorigenesis is relatively silent and patients experience late symptomatic presentation. As the option for curative treatments is limited to early stage cancers, diagnosis in non-symptomatic individuals is crucial. International guidelines advise regular surveillance of high-risk populations but the current tools lack sufficient sensitivity for early stage tumors on the background of a cirrhotic nodular liver. A number of novel biomarkers have now been suggested in the literature, which may reinforce the current surveillance methods. In addition, recent metabonomic and proteomic discoveries have established specific metabolite expressions in HCC, according to Warburgs phenomenon of altered energy metabolism. With clinical validation, a simple and non-invasive test from the serum or urine may be performed to diagnose HCC, particularly benefiting low resource regions where the burden of HCC is highest

    Carrier depletion and grain misorientations on individual grain boundaries of polycrystalline si thin films

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    Structural and microelectrical properties of grain boundaries (GBs) in polycrystalline Si thin films were investigated by electron backscattering diffraction (EBSD) and scanning capacitance microscopy (SCM). The SCM measurements revealed highly nonuniform carrier depletions among the GBs, indicating the variety of electrical properties due to the specific GB structures. The EBSD measurement showed that the films are weakly [001]-oriented with small fractions of grains in the [111] and [110] orientations. Comparison of the SCM and EBSD measurements taken on the same film area led to the following observations: (1) Σ3 GBs do not exhibit carrier depletions and thus do not have charged deep levels; (2) Some Σ9 GBs exhibit carrier depletions and some do not, indicating that the intrinsic Σ9 GBs do not have charged deep levels and the carrier depletions are due to impurity gettering at the GBs; (3) No significant relationship between the carrier depletion behavior and the grain misorientationwas found so far on the GBs with random misorientations; (4) The carrier depletion behavior does not depend only on the grain misorientation but also on the facet where the GB is taken. ©2009 IEEE.published_or_final_versionThe 34th IEEE Conference on Photovoltaic Specialists (PVSC 2009), Philadelphia, PA., 7-12 June 2009. In Conference Record, 2009, p. 000471-00047

    Optical response of grain boundaries in upgraded metallurgical-grade silicon for photovoltaics

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    Using upgraded metallurgical-grade silicon (UMG-Si) is a cost-effective and energy-efficient approach for the production of solar cells. Grain boundaries (GBs) play a major role in determining the device performance of multicrystalline Si (mc-Si) solar cells. In this study two UMG-Si wafers, one from the middle part of a brick and the other from the top part of the same brick, were investigated. An excellent correlation was found between the grain misorientation and the corresponding optical response of GBs as indicated by photoluminescence (PL) imaging, electron backscattered diffraction (EBSD), and cross-sectional transmission electron microscopy (TEM). In addition, the PL features at random GBs depend also on the impurity levels in the wafer. In particular the PL emission was greatly enhanced in the narrow regions close to the random GB in the top wafer, which is an interesting phenomenon that may have potential application in high efficiency light-emission diodes (LEDs) based on Si. © 2011 Elsevier B.V.postprin

    Conservative and disruptive modes of adolescent change in human brain functional connectivity

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    Adolescent changes in human brain function are not entirely understood. Here, we used multiecho functional MRI (fMRI) to measure developmental change in functional connectivity (FC) of resting-state oscillations between pairs of 330 cortical regions and 16 subcortical regions in 298 healthy adolescents scanned 520 times. Participants were aged 14 to 26 y and were scanned on 1 to 3 occasions at least 6 mo apart. We found 2 distinct modes of age-related change in FC: “conservative” and “disruptive.” Conservative development was characteristic of primary cortex, which was strongly connected at 14 y and became even more connected in the period from 14 to 26 y. Disruptive development was characteristic of association cortex and subcortical regions, where connectivity was remodeled: connections that were weak at 14 y became stronger during adolescence, and connections that were strong at 14 y became weaker. These modes of development were quantified using the maturational index (MI), estimated as Spearman’s correlation between edgewise baseline FC (at 14 y, FC14) and adolescent change in FC (ΔFC14−26), at each region. Disruptive systems (with negative MI) were activated by social cognition and autobiographical memory tasks in prior fMRI data and significantly colocated with prior maps of aerobic glycolysis (AG), AG-related gene expression, postnatal cortical surface expansion, and adolescent shrinkage of cortical thickness. The presence of these 2 modes of development was robust to numerous sensitivity analyses. We conclude that human brain organization is disrupted during adolescence by remodeling of FC between association cortical and subcortical areas

    Las emergencias y urgencias sociales desde los Servicios Sociales: el papel del Trabajo Social

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    Introducción: El campo de las urgencias y las emergencias sociales es uno de los considerados destacados por la disciplina de Trabajo Social. Este trabajo tiene como objetivo esclarecer el significado y utilización otorgados desde los servicios sociales a los términos urgencia y emergencia, tanto desde el punto de vista legislativo, como desde la visión de los/as trabajadores/as sociales que intervienen en estas situaciones, recogiendo además propuestas de mejora a nivel formativo. Material y métodos: Mediante una metodología cualitativa, se ha procedido al análisis de contenido de las leyes de Servicios Sociales de Aragón, Cataluña y Comunidad de Madrid, al tratarse de CCAA donde se han realizado importantes actuaciones en este ámbito en los últimos años. Además, se han realizado un total de siete entrevistas a trabajadores/as sociales de estas CCAA, con una larga trayectoria en este ámbito. Resultados: Se aprecian diferentes matices en los conceptos de urgencia y emergencia en la legislación de las tres CCAA analizadas, con las consecuentes diferencias en las intervenciones consideradas dentro de cada término. Por su parte, el discurso de los/as profesionales muestra más coincidencias, señalando la importante labor de los/as trabajadores/as sociales en este ámbito. Discusión: Se constata la indefinición y ambigüedad de los términos urgencia y emergencia social, la necesidad de esclarecer sus definiciones, así como la falta de formación específica en estas materias en los itinerarios académicos oficiales de Trabajo Social Introduction: The field of urgent and emergency care is one of those topics under consideration that is highlighted by the discipline of social work. This study aims to clarify the meaning and use given to the terms emergency care and urgent care by the social services, both from a legislative angle and also from the point of view of the social workers that intervene in such situations, while also gathering proposals for improvement related to training. Material and methods: Using a qualitative methodology, we proceeded to analyse the content of the social service laws in Aragon, Catalonia and the Region of Madrid, as these are autonomous regions where significant action had taken place in this area in recent years. In addition, seven interviews with social workers from these regions that had a long history working in this field had been carried out. Results: Various nuances have been perceived in the concepts of urgent care and emergency care in the legislation of the three regions analysed, with the resulting differences in the interventions under consideration within each term. For their part, the discourse of the professionals shows further coinncidences, highlighting the importance of the work carrried out by social workers in this area. Discussion: The vagueness and ambiguity of the terms urgent care and emergency care are noted, along with the need to clarify their definitions, as well as the lack of specific training in these subjects in the official academic itineraries of Social Work

    Quantum Non-Demolition Detection of Strongly Correlated Systems

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    Preparation, manipulation, and detection of strongly correlated states of quantum many body systems are among the most important goals and challenges of modern physics. Ultracold atoms offer an unprecedented playground for realization of these goals. Here we show how strongly correlated states of ultracold atoms can be detected in a quantum non-demolition scheme, that is, in the fundamentally least destructive way permitted by quantum mechanics. In our method, spatially resolved components of atomic spins couple to quantum polarization degrees of freedom of light. In this way quantum correlations of matter are faithfully mapped on those of light; the latter can then be efficiently measured using homodyne detection. We illustrate the power of such spatially resolved quantum noise limited polarization measurement by applying it to detect various standard and "exotic" types of antiferromagnetic order in lattice systems and by indicating the feasibility of detection of superfluid order in Fermi liquids.Comment: Published versio

    Adiposity has differing associations with incident coronary heart disease and mortality in the Scottish population: cross-sectional surveys with follow-up

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    Objective: Investigation of the association of excess adiposity with three different outcomes: all-cause mortality, coronary heart disease (CHD) mortality and incident CHD. Design: Cross-sectional surveys linked to hospital admissions and death records. Subjects: 19 329 adults (aged 18–86 years) from a representative sample of the Scottish population. Measurements: Gender-stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) for all-cause mortality, CHD mortality and incident CHD. Separate models incorporating the anthropometric measurements body mass index (BMI), waist circumference (WC) or waist–hip ratio (WHR) were created adjusted for age, year of survey, smoking status and alcohol consumption. Results: For both genders, BMI-defined obesity (greater than or equal to30 kg m−2) was not associated with either an increased risk of all-cause mortality or CHD mortality. However, there was an increased risk of incident CHD among the obese men (hazard ratio (HR)=1.78; 95% confidence interval=1.37–2.31) and obese women (HR=1.93; 95% confidence interval=1.44–2.59). There was a similar pattern for WC with regard to the three outcomes; for incident CHD, the HR=1.70 (1.35–2.14) for men and 1.71 (1.28–2.29) for women in the highest WC category (men greater than or equal to102 cm, women greater than or equal to88 cm), synonymous with abdominal obesity. For men, the highest category of WHR (greater than or equal to1.0) was associated with an increased risk of all-cause mortality (1.29; 1.04–1.60) and incident CHD (1.55; 1.19–2.01). Among women with a high WHR (greater than or equal to0.85) there was an increased risk of all outcomes: all-cause mortality (1.56; 1.26–1.94), CHD mortality (2.49; 1.36–4.56) and incident CHD (1.76; 1.31–2.38). Conclusions: In this study excess adiposity was associated with an increased risk of incident CHD but not necessarily death. One possibility is that modern medical intervention has contributed to improved survival of first CHD events. The future health burden of increased obesity levels may manifest as an increase in the prevalence of individuals living with CHD and its consequences

    Estudio preliminar de la combinación de vitaminas y bisfosfonatos en hueso maxilar de ratas

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    El balance óseo está mediado por una regulación inmunoendócrina, siendo éste un complejo proceso. Entre las acciones llevadas a cabo para mantener la densidad y estructura del esqueleto son variadas las farmacoterapias utilizadas. Diversos estudios han demostrado que tanto Alendronato, Vitamina D3 y Vitamina E contribuyen a la inhibición de la reabsorción ósea. Objetivo: Estudiar el efecto de la administración combinada de alendronato y vitamina D por vía subcutánea y de vitamina E por vía oral sobre la regeneración ósea. Materiales y métodos: La dosificación fue 0,5 mg/kg de peso corporal de AL, 50 mg/kg de vitamina D y 20 mg/kg de vitamina E. El efecto se evaluó en ratas machos Wistar (n=108), de 90 ± 20 g, divididas en 6 grupos. Se realizó la exodoncia de los primeros molares inferiores. La droga se inyectó en forma subcutánea en tiempos 0, 7, 15 y 30 días post cirugía. Se tomaron radiografías de las mandíbulas, en cada tiempo experimental y se analizaron con el Software Image ProPlus versión 4,1 de Media Cibernetics. Los estudios estadísticos se realizaron a través del análisis de la variancia. Resultados: Los estudios radiográficos demostraron un incremento en la densidad mineral ósea promedio (DMO) conforme avanza el tiempo en los grupos problemas analizados con respecto al control, siendo más evidentes los tratamientos con vitamina D a los 30 días. Conclusiones: Los datos evaluados sirven para mostrar una tendencia, pero son insuficientes como para detectar diferencias significativas al contrastar las drogas, si se observan cambios significativos entre etapas, como era previsible. Se continuará con la investigación para poder obtener resultados que permitan emitir conclusiones que avalen nuestra hipótesis de trabajo.Fil: Moro, Cecilia. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra Farmacología y Terapéutica A; Argentina.Fil: Aguzzi, Alejandra. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra Farmacología y Terapéutica A; Argentina.Fil: Virga, María Carolina. Universidad Nacional de Córdoba. Facultad de Odontología. Cátedra Farmacología y Terapéutica B; Argentina.Fil: Romero, S. Universidad Nacional de Tucumán. Facultad de Odontología; Argentina.Fil: Basualdo, MM. Universidad Nacional de Tucumán; Argentina.Otras Ciencias Médica

    Treatment of rats with a self-selected hyperlipidic diet, increases the lipid content of the main adipose tissue sites in a proportion similar to that of the lipids in the rest of organs and tissues

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    Adipose tissue (AT) is distributed as large differentiated masses, and smaller depots covering vessels, and organs, as well as interspersed within them. The differences between types and size of cells makes AT one of the most disperse and complex organs. Lipid storage is partly shared by other tissues such as muscle and liver. We intended to obtain an approximate estimation of the size of lipid reserves stored outside the main fat depots. Both male and female rats were made overweight by 4-weeks feeding of a cafeteria diet. Total lipid content was analyzed in brain, liver, gastrocnemius muscle, four white AT sites: subcutaneous, perigonadal, retroperitoneal and mesenteric, two brown AT sites (interscapular and perirenal) and in a pool of the rest of organs and tissues (after discarding gut contents). Organ lipid content was estimated and tabulated for each individual rat. Food intake was measured daily. There was a surprisingly high proportion of lipid not accounted for by the main macroscopic AT sites, even when brain, liver and BAT main sites were discounted. Muscle contained about 8% of body lipids, liver 1-1.4%, four white AT sites lipid 28-63% of body lipid, and the rest of the body (including muscle) 38-44%. There was a good correlation between AT lipid and body lipid, but lipid in"other organs" was highly correlated too with body lipid. Brain lipid was not. Irrespective of dietary intake, accumulation of body fat was uniform both for the main lipid storage and handling organs: large masses of AT (but also liver, muscle), as well as in the"rest" of tissues. These storage sites, in specialized (adipose) or not-specialized (liver, muscle) tissues reacted in parallel against a hyperlipidic diet challenge. We postulate that body lipid stores are handled and regulated coordinately, with a more centralized and overall mechanisms than usually assumed

    Gender discrepancy in research activities during radiology residency

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    Objective: To investigate the presence of gender disparity in academic involvement during radiology residency and to identify and characterize any gender differences in perceived barriers for conducting research. / Methods: An international call for participation in an online survey was promoted via social media and through multiple international and national radiological societies. A 35-question survey invited radiology trainees worldwide to answer questions regarding exposure and barriers to academic radiology during their training. Gender differences in response proportions were analyzed using either Fisher’s exact or chi-squared tests. / Results: Eight hundred fifty-eight participants (438 men, 420 women) from Europe (432), Asia (241), North and South America (144), Africa (37), and Oceania (4) completed the survey. Fewer women radiology residents were involved in research during residency (44.3%, 186/420 vs 59.4%, 260/438; p ≤ 0.0001) and had fewer published original articles (27.9%, 117/420 vs. 40.2%, 176/438; p = 0.001). Women were more likely to declare gender as a barrier to research (24.3%, 102/420 vs. 6.8%, 30/438; p < 0.0001) and lacked mentorship/support from faculty (65%, 273/420 vs. 55.7%, 244/438; p = 0.0055). Men were more likely to declare a lack of time (60.3%, 264/438 vs. 50.7%, 213/420; p = 0.0049) and lack of personal interest (21%, 92/438 vs. 13.6%, 57/420, p = 0.0041) in conducting research. / Conclusion: Fewer women were involved in academic activities during radiology residency, resulting in fewer original published studies compared to their men counterparts. This is indicative of an inherent gender imbalance. Lack of mentorship reported by women radiologists was a main barrier to research
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