1,622 research outputs found
Biomolecular sensing using surface micromachined silicon plates
Micromachined sensors to detect surface stress changes associated with interactions between an immobilized chemically selective receptor and a target analyte are presented. The top isolated sensing surface of a free-standing silicon plate is prepared with a thin Au layer, followed by a covalent attachment of chemical or biomolecule forming a chemically-selective surface. Surface stress changes in air are measured capacitively due to the formation of an alkanethiol self-assembled monolayer (SAM). Detection of biomolecular binding in liquid samples is measured optically using the streptavidin-biotin complex and AM. tuberculosis antigen-antibody system used for clinical tuberculosis (TB) diagnosis
Neutron beam test of CsI crystal for dark matter search
We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear
recoils and 's below 10 keV. The response of CsI crystals to nuclear
recoil was studied with mono-energetic neutrons produced by the
H(p,n)He reaction. This was compared to the response to Compton
electrons scattered by 662 keV -ray. Pulse shape discrimination between
the response to these 's and nuclear recoils was studied, and quality
factors were estimated. The quenching factors for nuclear recoils were derived
for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM
Change in fatty liver status and 5-year risk of incident metabolic syndrome: a retrospective cohort study
INTRODUCTION: Fatty liver is associated with metabolic syndrome (MetS) but it may also occur without MetS. Whether resolution of fatty liver in the general population affects risk of MetS is unknown. Our aim was to determine whether a change in fatty liver status (either the development of new fatty liver or the resolution of existing fatty liver) would modify the risk of de novo MetS.METHODS:Two thousand eighty-nine people without hypertension, diabetes, and MetS were examined at baseline and at 5-year follow-up using a retrospective cohort study design. Fatty liver status was assessed at baseline and at follow-up by ultrasonography. Adjusted hazard ratios (aHR) and 95 % confidence intervals (CIs) for de novo MetS at follow-up were calculated controlling for the potential confounders, compared to the reference group (people who never had fatty liver at baseline and follow-up).RESULTS:During follow-up, fatty liver developed in 251 people and fatty liver resolved in 112 people. After the adjustment for multiple confounders, persisting fatty liver and incident fatty liver development were associated with de novo MetS, with aHR of 2.60 (95 % CIs [1.61,4.20]) and 3.31 (95 % CIs [1.99,5.51]), respectively. Risk of new MetS in resolved fatty liver group was attenuated with insignificant aHR of 1.29 accompanying 95 % CIs of 0.60 and 2.80.DISCUSSION:Development or maintenance of fatty liver is positively associated with occurrence of new MetS. Resolution of fatty liver status has similar risk of de novo MetS with those who never had fatty liver. Therefore, cautious management is needed with those with fatty liver
A ten-year comparison of women authorship in U.S. dermatology literature, 1999 vs. 2009
Women are entering medicine at increasing rates, particularly in dermatology. In this study, we compared women’s influence and status in academic dermatology with that of men by examining authorship roles in peer-reviewed dermatology literature.Weexamined the literature in2009 and compared that to10 years prior (1999).Atotal of 1399 articles were reviewed, 594 of whichmet study criteria andwere included in statistical analysis. There was amarked increase in senior female authorship over a decade (22% vs. 38%, p b 0.001). Female first authorship increased as well (41% vs. 51%, p b 0.001). In contrast, changes in male senior and first authorship were not statistically significant. Federal funding for female senior authors increased over a decade (19% vs. 37%, p=0.05), and female senior authors in the 2009 cohort were more likely to hold a dual MD/PhD degree (0% vs. 11%, p=0.04) or pure PhD degree (11% vs. 27%, p = 0.04).Women are approaching parity with men in terms of authorship in the dermatology literature, and additional research training and attainment of federal funding have helped women publish as senior authors
Hybrid exotic meson with J^{PC}=1^{-+} in AdS/QCD
We investigate the hybrid exotic meson with within the
framework of an AdS/QCD model. Introducing a holographic field dual to the
operator for hybrid exotic meson, we obtain the eigen-value equation for its
mass. Fixing all free parameters by QCD observables such as the -meson
mass, we predict the masses of the hybrid exotic meson. The results turn out to
be for the ground state, and for the
first excited one. Being compared with the existing experimental data for the
, which is known to be , the
present result seems to be qualitative in agreement with it. We also predict
the decay constant of (1400): MeV.Comment: 10 pages, 1 Tabl
Noninvasively Predicting Hemodynamic Response to Carvedilol in Cirrhotic Patients With Varices: You Have Some Ex-Spleening to Do
Gastroesophageal varices are present in approximately 50% of patients with cirrhosis and variceal hemorrhage occurs at a rate of about 10%–15% per year (N Engl J Med 1988;319:983–989; Gastrointest Endosc 2007;65:82–88). Nonselective beta-blockers (NSBB) or variceal band ligation are currently recommended as primary prophylaxis against variceal hemorrhage in patients with large or high-risk varices (J Hepatol 2015;63:743–752; Hepatology 2017;65:310–335). The goal of NSBB therapy is to reduce portal pressures, which can formally be assessed by measuring the hepatic venous pressure gradient (HVPG)
The assessment of Shin's method for the prediction of creatinine kinase-MB elevation after percutaneous coronary intervention: an intravascular ultrasound study
Cardiac enzyme release is common after percutaneous coronary intervention (PCI). At present there is no established relationship between the quantity of necrotic core and dense calcium, as assessed by Shin's method using intravascular ultrasound virtual histology (VH-IVUS), and post-PCI creatinine kinase-MB (CK-MB) elevation. A total of 112 consecutive patients with unstable angina and a normal pre-PCI CK-MB level were imaged using VH-IVUS. Patients were divided into 2 groups according to the presence (CK-MB group, n = 22) or absence (non CK-MB group, n = 90) of a post-PCI CK-MB elevation >1.0 the upper limit of normal (3.6 ng/ml). Using Shin's method contours were drawn around the IVUS catheter (instead of the lumen), and the vessel. Mean area and volume of necrotic core and dense calcium were significantly greater in CK-MB group than in non CK-MB group (1.7 ± 0.9 mm2vs. 0.9 ± 0.6 mm2, P < 0.001; 17.2 ± 8.8 mm3vs. 8.8 ± 5.8 mm3, P < 0.001, and 0.9 ± 0.6 mm2vs. 0.4 ± 0.4 mm2, P = 0.001; 9.1 ± 5.8 mm3vs. 3.9 ± 3.7 mm3, P < 0.001, respectively). Percent necrotic core and dense calcium areas calculated by external elastic membrane (EEM) area were significantly greater in CK-MB group than in non CK-MB group (11.9 ± 5.1 vs. 6.6 ± 4.0%, P < 0.001 and 6.5 ± 4.0 vs. 3.0 ± 2.9%, P
Thirty Years of Cometary Spectroscopy from McDonald Observatory
We report on the results of a spectroscopic survey of 130 comets that was
conducted at McDonald observatory from 1980 through 2008. Some of the comets
were observed on only one night, while others were observed repeatedly. For 20
of these comets, no molecules were detected. For the remaining 110 comets, some
emission from CN, OH, NH, C, C, CH, and NH molecules were
observed on at least one occasion. We converted the observed molecular column
densities to production rates using a Haser (1957) model. We defined a
restricted data set of comets that had at least 3 nights of observations. The
restricted data set consists of 59 comets. We used ratios of production rates
to study the trends in the data. We find two classes of comets: typical and
carbon-chain depleted comets. Using a very strict definition of depleted
comets, requiring C \underline{and} C to both be depleted, we find
9% of our restricted data set comets to be depleted. Using a more relaxed
definition that requires only C to be below a threshold (similar to other
researchers), we find 25% of the comets are depleted. Two-thirds of the
depleted comets are Jupiter Family comets, while one-third are Long Period
comets. 37% of the Jupiter Family comets are depleted, while 18.5% of the Long
Period comets are depleted. We compare our results with other studies and find
good agreement.Comment: Accepted for Icarus; 15 figures, 9 tables (some multi-page and in
landscape mode
Recommended from our members
Development of GAMMA Code and Evaluation for a Very High Temperature gas-Cooled Reactor
The very high-temperature gas-cooled reactor (VHTR) is envisioned as a single- or dual-purpose reactor for electricity and hydrogen generation. The concept has average coolant temperatures above 9000C and operational fuel temperatures above 12500C. The concept provides the potential for increased energy conversion efficiency and for high-temperature process heat application in addition to power generation. While all the High Temperature Gas Cooled Reactor (HTGR) concepts have sufficiently high temperature to support process heat applications, such as coal gasification, desalination or cogenerative processes, the VHTR’s higher temperatures allow broader applications, including thermochemical hydrogen production. However, the very high temperatures of this reactor concept can be detrimental to safety if a loss-of-coolant accident (LOCA) occurs. Following the loss of coolant through the break and coolant depressurization, air will enter the core through the break by molecular diffusion and ultimately by natural convection, leading to oxidation of the in-core graphite structure and fuel. The oxidation will accelerate heatup of the reactor core and the release of toxic gasses (CO and CO2) and fission products. Thus, without any effective countermeasures, a pipe break may lead to significant fuel damage and fission product release. Prior to the start of this Korean/United States collaboration, no computer codes were available that had been sufficiently developed and validated to reliably simulate a LOCA in the VHTR. Therefore, we have worked for the past three years on developing and validating advanced computational methods for simulating LOCAs in a VHTR. This paper will also include what improvements will be made in the Gamma code for the VHTR
- …