458 research outputs found
Volatile Organic Compound and Metabolite Signatures as Pathogen Identifiers and Biomarkers of Infectious Disease
Volatile organic compound (VOC)-based diagnostics have great potential to be the next generation of screening tools for pathogen identification and infectious disease management. VOCs are low molecular weight metabolic compounds that have high vapor pressures and low boiling points, both of which facilitate evaporation at ambient temperatures. There is increasing evidence that particular VOCs, or profiles of VOCs, are unique to various disease states. Different pathogenic species have been found to produce characteristic profiles of VOCs by virtue of their distinct metabolisms. The detection of these metabolite profiles from patient samples could provide an effective means of rapid, non-invasive pathogen identification, thus enabling early diagnosis and treatment. In this review, we will discuss the potential of VOC profiles to be utilized as biomarkers of pathogenic infection, with a focus on bacterial pathogens. Herein we describe the common methods for clinical VOC sample collection, provide an overview of the various instruments and techniques used for VOC detection and analysis, and summarize the key findings of recent studies that have investigated VOC biomarkers in various infectious diseases. We will also discuss the challenges associated with translating VOC analysis into a clinical diagnostic tool
Earth matter density uncertainty in atmospheric neutrino oscillations
That muon neutrinos oscillating into the mixture of tau neutrinos
and sterile neutrinos has been studied to explain the
atmospheric disappearance. In this scenario, the effect of Earth
matter is a key to determine the fraction of . Considering that the
Earth matter density has uncertainty and this uncertainty has significant
effects in some neutrino oscillation cases, such as the CP violation in very
long baseline neutrino oscillations and the day-night asymmetry for solar
neutrinos, we study the effects caused by this uncertainty in the above
atmospheric oscillation scenario. We find that this uncertainty
seems to have no significant effects and that the previous fitting results need
not to be modified fortunately.Comment: 7 pages, 1 figure, to appear in Phys. Rev.
Electronic pressure on ferromagnetic domain wall
The scattering of the eletron by a domain wall in a nano-wire is studied
perturbatively to the lowest order. The correction to the thermodaynamic
potential of the electron system due to the scattering is calculated from the
phase shift. The wall profile is determined by taking account of this
correction, and the result indicates that the wall in a ferromagnet with small
exchange coupling can be squeezed to be very thin to lower the electron energy
Domain walls and the conductivity of mesoscopic ferromagnets
Quantum interference phenomena in the conductivity of mesoscopic ferromagnets
are considered, particularly with regard to the effects of geometric phases
acquired by electrons propagating through regions of spatially varying
magnetization (due, e.g., to magnetic domain walls). Weak localization and
electron-electron interaction quantum corrections to the conductivity and
universal conductance fluctuations are discussed. Experiments are proposed for
multiply-connected geometries that should reveal conductance oscillations with
variations of the profile of the magnetization.Comment: 4 pages, 1 fugure, RevTEX, Submitted to Phys. Rev. Let
Domain Wall Resistance based on Landauer's Formula
The scattering of the electron by a domain wall in a nano-wire is calculated
perturbatively to the lowest order. The resistance is calculated by use of
Landauer's formula. The result is shown to agree with the result of the linear
response theory if the equilibrium is assumed in the four-terminal case
Extrinsic inhomogeneity effects in magnetic, transport and magnetoresistive properties of La_{1-x}Ca_{x}MnO_{3} (x\approx 0.33) crystal prepared by the floating zone method
The paper describes a study of the magnetic, transport and magnetoresistive
properties of La_{1-x}Ca_{x}MnO_{3} (x\approx 0.33) crystals prepared by the
floating-zone method. We found that these properties testify to rather good
crystal perfection of the sample studied. In particular, a huge
magnetoresistance ([R(0)-R(H)]/R(H) in the field H = 5 T is about 2680 %) is
found near the Curie temperature (216 K). At the same time, some distinct
features of measured properties indicate the influence of extrinsic
inhomogeneities arising due to technological factors in the sample preparation.
Analysis of the data obtained shows that these are rare grain boundaries and
twins. Specific influence of the grain-boundary-like inhomogeneities on the
transport and magnetoresistive properties are considered.Comment: Submitted to Physica
Differences of Clinical Characteristics and Phenotypes between Prepubertal- and Adolescent-Onset Bipolar Disorders
The aim of this study is to describe the clinical characteristics of prepubertal- and adolescent-onset bipolar disorder (BD) and to identify any clinical differences between patients with prepubertal- and adolescent-onset BD. We analyzed the clinical records of 53 inpatients with BD. These patients were divided into prepubertal-onset and adolescent-onset groups. We also divided the subjects into narrow, intermediate, and broad phenotypes according to the definitions proposed by Leibenluft and colleagues. Of the total sample, 16 patients (30.2%) were in the prepubertal-onset group and 37 (69.8%) were in the adolescent-onset group. Patients with prepubertal-onset BD were more likely to display an insidious clinical presentation, atypical features, and comorbid psychopathology. And the majority of the subjects, especially in the prepubertal-onset group, were classified under the intermediate and broad phenotypes. These results suggest that the clinical presentation of BD with prepubertal-onset is different from that of adolescent-onset BD. It is inferred that a significant number of patients with prepubertal- and adolescent-onset BD do not meet DSM-IV criteria for mania or hypomania from the results of this study
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