395 research outputs found
Clinical predictors of inflammatory bowel disease in a genetically well-defined Caucasian population
<p>Abstract</p> <p>Background</p> <p>Crohn's disease (CD) and ulcerative colitis (UC), the two main types of inflammatory bowel disease (IBD), are multifactorial conditions of unknown etiology. The objective of this study is to examine the combined gene-environment interactions influencing IBD susceptibility in a well-defined Caucasian cohort in rural mid-America.</p> <p>Methods</p> <p>Patients were diagnosed to have CD or UC using conventional radiologic, endoscopic, and/or histopathologic findings. Histological diagnosis was made by a single specialist gastrointestinal pathologist with a particular interest in IBD. Information regarding cigarette smoke exposure was obtained by administration of the Behavioral Risk Factor Surveillance System Survey (BRFSS) to all patients. Genomic DNA was extracted from peripheral blood leukocytes, and polymerase chain reaction (PCR) amplification and genotyping were performed for 11 Single Nucleotide Polymorphisms (SNP) in <it>NOD2</it>, <it>IL23r</it>, <it>OCTN1 </it>genes along with <it>IGR</it>.</p> <p>Results</p> <p>Our cohort consists of 1196 patients: 435 controls, 485 CD patients, and 276 UC patients. Only patients with genotype data for at least 7 of 11 SNPs were included in our data analysis. The control groups for all 11 SNPs were in Hardy-Weinberg Equilibrium. In genotype-association SNP analysis, all <it>NOD2 </it>SNPs (rs5743293, rs2066844, rs2066845) and the <it>IL23r </it>SNP (rs11465804) showed a significant association to IBD (<it>p </it>< 0.03). A multiple gene-interaction analysis showed an association between <it>NOD2 </it>and <it>IL23r </it>with UC (<it>p </it>= 0.04). There were no associations between any <it>OCTN1 </it>and <it>IGR </it>SNPs and IBD in this cohort. A multivariable logistic regression analysis showed that female gender, "current" or "former" smoking status, family history of IBD, and <it>NOD2 </it>SNP minor alleles were associated with CD.</p> <p>Conclusion</p> <p>IBD remains to be challenging to properly diagnose, characterize, and treat. Our study proposes a combined genetic, phenotypic, and environmental approach in an attempt to better understand IBD. Previously demonstrated associations between OCTN1 and IGR and IBD were not confirmed.</p
Circumstances and factors associated with accidental deaths among children, adolescents and young adults in Cuiaba, Brazil
Properties of Graphene: A Theoretical Perspective
In this review, we provide an in-depth description of the physics of
monolayer and bilayer graphene from a theorist's perspective. We discuss the
physical properties of graphene in an external magnetic field, reflecting the
chiral nature of the quasiparticles near the Dirac point with a Landau level at
zero energy. We address the unique integer quantum Hall effects, the role of
electron correlations, and the recent observation of the fractional quantum
Hall effect in the monolayer graphene. The quantum Hall effect in bilayer
graphene is fundamentally different from that of a monolayer, reflecting the
unique band structure of this system. The theory of transport in the absence of
an external magnetic field is discussed in detail, along with the role of
disorder studied in various theoretical models. We highlight the differences
and similarities between monolayer and bilayer graphene, and focus on
thermodynamic properties such as the compressibility, the plasmon spectra, the
weak localization correction, quantum Hall effect, and optical properties.
Confinement of electrons in graphene is nontrivial due to Klein tunneling. We
review various theoretical and experimental studies of quantum confined
structures made from graphene. The band structure of graphene nanoribbons and
the role of the sublattice symmetry, edge geometry and the size of the
nanoribbon on the electronic and magnetic properties are very active areas of
research, and a detailed review of these topics is presented. Also, the effects
of substrate interactions, adsorbed atoms, lattice defects and doping on the
band structure of finite-sized graphene systems are discussed. We also include
a brief description of graphane -- gapped material obtained from graphene by
attaching hydrogen atoms to each carbon atom in the lattice.Comment: 189 pages. submitted in Advances in Physic
Adaptação da versão saúde bucal do instrumento de diagnóstico do estágio de desenvolvimento da rede de atenção à saúde
Healthy diet in primary care: views of general practitioners and nurses from Europe
Background: Most of the national colleges of general practitioners (GPs) do not have their own dietary/nutritional tools, and GPs and nurses do not have the time, knowledge, or skills to advise their patients about desirable dietary practices. Objective: To assess the usefulness of a simple and practical guide on healthy diet to be used by European GPs and nurses. Design: A postal survey was mailed to 171 GPs and nurses from 12 European countries to obtain information about the usefulness of a guide on healthy diet developed by EUROPREV. Results: The perception of health professionals is that the main source of information on healthy diet for the population was the media. In all, 95% of GPs and nurses reported that the guide was useful; 93, 95, and 82% reported that the concepts were concise, easy to understand, and realistic, respectively. Also, 77% reported that the type of counselling recommended was feasible and could be applied, 94% reported that the implementation measures proposed could be effective and 88% reported that the Traditional Mediterranean Diet Pyramid is useful, but some concerns about the content were mentioned. Conclusions: GPs and nurses from Europe think that a practical guide on healthy diet developed by EUROPREV could be used to advise patients in primary care, although the Traditional Mediterranean Diet Pyramid should be modified
Reliability and construct validity of the Instrument to Measure the Impact of Valve Heart Disease on the Patient's Daily Life
X-Ray Spectroscopy of Stars
(abridged) Non-degenerate stars of essentially all spectral classes are soft
X-ray sources. Low-mass stars on the cooler part of the main sequence and their
pre-main sequence predecessors define the dominant stellar population in the
galaxy by number. Their X-ray spectra are reminiscent, in the broadest sense,
of X-ray spectra from the solar corona. X-ray emission from cool stars is
indeed ascribed to magnetically trapped hot gas analogous to the solar coronal
plasma. Coronal structure, its thermal stratification and geometric extent can
be interpreted based on various spectral diagnostics. New features have been
identified in pre-main sequence stars; some of these may be related to
accretion shocks on the stellar surface, fluorescence on circumstellar disks
due to X-ray irradiation, or shock heating in stellar outflows. Massive, hot
stars clearly dominate the interaction with the galactic interstellar medium:
they are the main sources of ionizing radiation, mechanical energy and chemical
enrichment in galaxies. High-energy emission permits to probe some of the most
important processes at work in these stars, and put constraints on their most
peculiar feature: the stellar wind. Here, we review recent advances in our
understanding of cool and hot stars through the study of X-ray spectra, in
particular high-resolution spectra now available from XMM-Newton and Chandra.
We address issues related to coronal structure, flares, the composition of
coronal plasma, X-ray production in accretion streams and outflows, X-rays from
single OB-type stars, massive binaries, magnetic hot objects and evolved WR
stars.Comment: accepted for Astron. Astrophys. Rev., 98 journal pages, 30 figures
(partly multiple); some corrections made after proof stag
f(R) theories
Over the past decade, f(R) theories have been extensively studied as one of
the simplest modifications to General Relativity. In this article we review
various applications of f(R) theories to cosmology and gravity - such as
inflation, dark energy, local gravity constraints, cosmological perturbations,
and spherically symmetric solutions in weak and strong gravitational
backgrounds. We present a number of ways to distinguish those theories from
General Relativity observationally and experimentally. We also discuss the
extension to other modified gravity theories such as Brans-Dicke theory and
Gauss-Bonnet gravity, and address models that can satisfy both cosmological and
local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in
Relativity, Published version, Comments are welcom
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