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MECANISMOS DE INGENIERíA DE ROCAS PARA TALUDES Y EXCAVACIONES SUBTERRáNEAS
HUDSON,JOHN A.; CASTRO CAICEDO,ALVARO J.;
Boletín de Ciencias de la Tierra , 2010,
Abstract: the original document has no abstract.
Dielectric confinement on exciton binding energy and nonlinear optical properties in a strained Zn1-xinMgxinSe/Zn1-xoutMgxoutSe quantum well
Dielectric confinement on exciton binding energy and nonlinear optical properties in a strained ZnMgSe quantum well

J Abraham Hudson Mark,A John Peter,
J. Abraham Hudson Mark
,A. John Peter

半導體學報 , 2012,
Abstract: The band offsets for a Zn1-xinMgxinSe/Zn1-xoutMgxoutSe quantum well heterostructure are determined using the model solid theory. The heavy hole exciton binding energies are investigated with various Mg alloy contents. The effect of mismatch between the dielectric constants between the well and the barrier is taken into account. The dependence of the excitonic transition energies on the geometrical confinement and the Mg alloy is discussed. Non-linear optical properties are determined using the compact density matrix approach. The linear, third order non-linear optical absorption coefficient values and the refractive index changes of the exciton are calculated for different concentrations of magnesium. The results show that the occurred blue shifts of the resonant peak due to the Mg incorporation give the information about the variation of two energy levels in the quantum well width.
Patterns of upper gastrointestinal diseases based on endoscopy in the period 1998-2001
Hudson Lodenyo, Fasana Rana, Geoffrey Z Mutuma, John M Kabanga, Julius K Kuria, Fredrick A Okoth
African Journal of Health Sciences , 2005,
Abstract: Upper gastrointestinal complaints are common in Kenya. Though these have remained unchanged over the last 20 years, the pattern of upper gastrointestinal disease on endoscopic examination seems to be changing. There appears to be progressive increase in oesophagitis and cancer of the stomach. Peptic ulcer disease has remained stable while Cancer of the oesophagus is still common. The paper intends to report on endoscopic findings at the Centre for Clinical Research, Kenya Medical Research Institute (KEMRI) over the period October 1998 and May 2001. The sources of information are records made at the time of endoscopy and histology reports on biopsies taken. Seven hundred and sixty eight patients were endoscoped. The male to female ratio was 1.7:1 with mean age ±SD of 40.8 ±20.1 years and age range was 3 to 96 years. Majority of the patients had abnormal findings with gastritis being the most common (25.8%). It is concluded that gastritis is an important cause of morbidity in Kenya. Oesophagitis, mainly due to gastroesopahageal reflux disease, seems to be on the increase. Gastric cancer is not as rare as previously thought and peptic ulcer disease is still common. African Journal of Health Sciences Vol. 12(1-2) 2005: 49-54
Rheumatoid arthritis: Disease or syndrome?
Jessica A Stanich, John D Carter, Judith Whittum-Hudson, et al
Open Access Rheumatology: Research and Reviews , 2009, DOI: http://dx.doi.org/10.2147/OARRR.S7680
Abstract: matoid arthritis: Disease or syndrome? Review (9245) Total Article Views Authors: Jessica A Stanich, John D Carter, Judith Whittum-Hudson, et al Published Date December 2009 Volume 2009:1 Pages 179 - 192 DOI: http://dx.doi.org/10.2147/OARRR.S7680 Jessica A Stanich1, John D Carter2, Judith Whittum-Hudson1, Alan P Hudson1 1Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA; 2Division of Rheumatology, Department of Internal Medicine, University of South Florida School of Medicine, Tampa, FL, USA Abstract: Rheumatoid arthritis (RA) has been described in the medical literature for over two hundred years, but its etiology remains unknown. RA displays phenotypic heterogeneity, and it is a relatively prevalent clinical entity: it affects approximately 1% of the population, resulting in enormous pathologic sequelae. Earlier studies targeting the cause(s) of RA suggested potential infectious involvement, whereas more recent reports have focused on a genetic origin of the disease. However, neither infection nor genetics, nor any other single factor is currently accepted as causative of RA. In this article we review studies relating to the etiology of RA, and those of several related matters, and we conclude that the literature indeed does provide insight into the causes underlying the initiation of RA pathogenesis. Briefly, given the remarkable phenotypic variation of RA, especially in its early stages, as well as a number of other characteristics of the condition, we contend that RA is not a discrete clinical entity with a single etiological source. Rather, we argue that it represents a common clinical endpoint for various starting points, each of which is largely guided by as yet poorly understood aspects of the genetic background of the affected individual. Adoption of this alternative view of the origin of RA will have significant consequences for future research and for development of new therapeutic interventions for this burdensome condition.
Rheumatoid arthritis: Disease or syndrome?
Jessica A Stanich,John D Carter,Judith Whittum-Hudson,et al
Open Access Rheumatology: Research and Reviews , 2009,
Abstract: Jessica A Stanich1, John D Carter2, Judith Whittum-Hudson1, Alan P Hudson11Department of Immunology and Microbiology, Wayne State University School of Medicine, Detroit, MI, USA; 2Division of Rheumatology, Department of Internal Medicine, University of South Florida School of Medicine, Tampa, FL, USAAbstract: Rheumatoid arthritis (RA) has been described in the medical literature for over two hundred years, but its etiology remains unknown. RA displays phenotypic heterogeneity, and it is a relatively prevalent clinical entity: it affects approximately 1% of the population, resulting in enormous pathologic sequelae. Earlier studies targeting the cause(s) of RA suggested potential infectious involvement, whereas more recent reports have focused on a genetic origin of the disease. However, neither infection nor genetics, nor any other single factor is currently accepted as causative of RA. In this article we review studies relating to the etiology of RA, and those of several related matters, and we conclude that the literature indeed does provide insight into the causes underlying the initiation of RA pathogenesis. Briefly, given the remarkable phenotypic variation of RA, especially in its early stages, as well as a number of other characteristics of the condition, we contend that RA is not a discrete clinical entity with a single etiological source. Rather, we argue that it represents a common clinical endpoint for various starting points, each of which is largely guided by as yet poorly understood aspects of the genetic background of the affected individual. Adoption of this alternative view of the origin of RA will have significant consequences for future research and for development of new therapeutic interventions for this burdensome condition.Keywords: rheumatoid arthritis pathogenesis etiologic studies genetic background
Identification of Multiple Subtypes of Campylobacter jejuni in Chicken Meat and the Impact on Source Attribution
Megan L. Devane,Brent J. Gilpin,Beth Robson,John D. Klena,Marion G. Savill,John A. Hudson
Agriculture , 2013, DOI: 10.3390/agriculture3030579
Abstract: Most source attribution studies for Campylobacter use subtyping data based on single isolates from foods and environmental sources in an attempt to draw epidemiological inferences. It has been suggested that subtyping only one Campylobacter isolate per chicken carcass incurs a risk of failing to recognise the presence of clinically relevant, but numerically infrequent, subtypes. To investigate this, between 21 and 25 Campylobacter jejuni isolates from each of ten retail chicken carcasses were subtyped by pulsed-field gel electrophoresis (PFGE) using the two restriction enzymes SmaI and KpnI. Among the 227 isolates, thirteen subtypes were identified, the most frequently occurring subtype being isolated from three carcasses. Six carcasses carried a single subtype, three carcasses carried two subtypes each and one carcass carried three subtypes. Some subtypes carried by an individual carcass were shown to be potentially clonally related. Comparison of C. jejuni subtypes from chickens with isolate subtypes from human clinical cases ( n = 1248) revealed seven of the thirteen chicken subtypes were indistinguishable from human cases. None of the numerically minor chicken subtypes were identified in the human data. Therefore, typing only one Campylobacter isolate from individual chicken carcasses may be adequate to inform Campylobacter source attribution.
Colours of Bulges and Discs within Galaxy Clusters and the Signature of Disc Fading on Infall
Michael J. Hudson,Jeffrey B. Stevenson,Russell J. Smith,Gary A. Wegner,John R. Lucey,Luc Simard
Physics , 2010, DOI: 10.1111/j.1365-2966.2010.17318.x
Abstract: The origins of the bulge and disc components of galaxies are of primary importance to understanding galaxy formation. Here bulge-disc decomposition is performed simultaneously in B- and R-bands for 922 bright galaxies in 8 nearby (z < 0.06) clusters with deep redshift coverage using photometry from the NOAO Fundamental Plane Survey. The total galaxy colours follow a universal colour-magnitude relation (CMR). The discs of L_* galaxies are 0.24 magnitudes bluer in $B-R$ than bulges. Bulges have a significant CMR slope while the CMR slope of discs is flat. Thus the slope of the CMR of the total light is driven primarily (60%) by the bulge-CMR, and to a lesser extent (40%) by the change in the bulge-to-total ratio as a function of magnitude. The colours of the bulge and disc components do not depend on the bulge-to-total ratio, for galaxies with bulge-to-total ratios greater than 0.2. While the colours of the bulge components do not depend significantly on environment, the median colours of discs vary significantly, with discs in the cluster centre redder by 0.10 magnitudes than those at the virial radius. Thus while star formation in bulges appears to be regulated primarily by mass-dependent, and hence presumably internal, processes, that of discs is affected by the cluster environment.
p53-Dependent and Cell Specific Epigenetic Regulation of the Polo-like kinases under Oxidative Stress
Alejandra Ward, John W. Hudson
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0087918
Abstract: The polo-like kinase (PLKs) family, consisting of five known members, are key regulators of important cell cycle processes, which include mitotic entry, centrosome duplication, spindle assembly, and cytokinesis. The PLKs have been implicated in a variety of cancers, such as hepatocellular carcinoma (HCC), with PLK1 typically overexpressed and PLKs 2–5 often downregulated. Altered expression of the PLKs in malignancy is often correlated with aberrant promoter methylation. Epigenetic marks are dynamic and can be modified in response to external environmental stimuli. The aim of our study was to determine if oxidative stress, a common feature of solid tumours, would induce changes to the promoter methylation of the PLKs resulting in changes in expression. We examined the promoter methylation status via MSP and subsequent expression levels of the PLK family members under exposure to hypoxic conditions or reactive oxygen species (ROS). Interestingly, murine embryonic fibroblasts exposed to hypoxia and ROS displayed significant hypermethylation of Plk1 and Plk4 promoter regions post treatment. Corresponding proteins were also depleted by 40% after treatment. We also examined the HCC-derived cell lines HepG2 and Hep3B and found that for PLK1 and PLK4, the increase in hypermethylation was correlated with the presence of functional p53. In p53 wild-type cells, HepG2, both PLK1 and PLK4 were repressed with treatment, while in the p53 null cell line, Hep3B, PLK4 protein was elevated in the presence of hypoxia and ROS. This was also the case for ROS-treated, p53 null, osteosarcoma cells, Saos-2, where the PLK4 promoter became hypomethylated and protein levels were elevated. Our data supports a model in which the PLKs are susceptible to epigenetic changes induced by microenvironmental cues and these modifications may be p53-dependent. This has important implications in HCC and other cancers, where epigenetic alterations of the PLKs could contribute to tumourigenesis and disease progression.
Production of cold formaldehyde molecules for study and control of chemical reaction dynamics with hydroxyl radicals
Eric R. Hudson,Christopher Ticknor,Brian C. Sawyer,Craig A. Taatjes,H. J. Lewandowski,J. R. Bochinski,John L. Bohn,Jun Ye
Physics , 2005, DOI: 10.1103/PhysRevA.73.063404
Abstract: We propose a method for controlling a class of low temperature chemical reactions. Specifically, we show the hydrogen abstraction channel in the reaction of formaldehyde (H$_{2}$CO) and the hydroxyl radical (OH) can be controlled through either the molecular state or an external electric field. We also outline experiments for investigating and demonstrating control over this important reaction. To this end, we report the first Stark deceleration of the H$_{2}$CO molecule. We have decelerated a molecular beam of H$_{2}$CO essentially to rest, producing cold molecule packets at a temperature of 100 mK with a few million molecules in the packet at a density of $\sim10^{6}$ cm$^{-3}$.
New x-ray measurements in Helium-like Atoms increase discrepancy between experiment and theoretical QED
Christopher T. Chantler,Andrew T. Payne,John D. Gillaspy,Lawrence T. Hudson,Lucas F. Smale,Albert Henins,Justin A. Kimpton,Endre Takacs
Physics , 2014, DOI: 10.1088/1367-2630/16/12/123037
Abstract: A recent 15 parts-per-million (ppm) experiment on muonic hydrogen found a major discrepancy with QED and independent nuclear size determinations. Here we find a significant discrepancy in a different type of exotic atom, a medium-Z nucleus with two electrons. Investigation of the data collected is able to discriminate between available QED formulations and reveals a pattern of discrepancy of almost 6 standard errors of experimental results from the most recent theoretical predictions with a functional dependence proportional to Z^n where n=4. In both the muonic and highly charged systems, the sign of the discrepancy is the same, with the measured transition energy higher than predicted. Some consequences are possible or probable, and some are more speculative. This may give insight into effective nuclear radii, the Rydberg, the fine-structure constant or unexpectedly large QED terms.
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