5,210 research outputs found
Cardiotonic Modulation in Heart Failure Insights From Traditional Chinese Medicine∗
Medicinal herbs have been used over the past centuries for restoring the body's homeostatic balance. Contemporary use of herbal supplements remains widespread in many cultures as treatment for specific ailments. Many possess cardiovascular actions, and some interact with cardiac medications. However, there is variable scientific evidence with respect to their safety and efficacy, and few have been subjected to the same rigorous evaluation processes and regulations as contemporary pharmaceuticals (1). In the field of heart failure, we have also witnessed the failure of promising naturopathic therapies like hawthorn extract in translating their potential benefits in rigorous clinical trials (2,3)
Dealing with Uncertainty in Engineering Design for Large-Scale Gravel Soil Slopes in the Three Gorges Reservoir Zone
The objective of this paper is to first present a general formulation for analysis of uncertainties and evaluation of risks associated with large-scale slopes. The risks may be expressed in terms of the reliability of the system and the consequence. Preliminary studies regarding the mitigation of landslides in the Three-Gorge reservoir zone (TGRZ) of the Yangtze River is presented next. At the normal water level of 175 m, the Three-Gorge reservoir stretches for 665 km along the Yangtze River and extends into many tributaries. Some 684 colluvial deposits, ancient slides and hanging rock blocks, which are larger than 100,000 m3 individually, and numerous smaller landslides have been identified. Since 2001, over 650 landslides of varies sizes and 2300 cut slopes at low elevations in the Chongqing section of the Yangtze River have been or are being stabilized. This paper deals with three subjects related to the landslides in the TGRZ. The general characteristics of the landslides and the consequences of these landslides are described first. The main causes of activation are considered to be rainfall infiltration, reservoir level fluctuations, and human activities. An attempt is then made to summarize the uncertainties in the design of the slope stabilization works against slope failure due to rainfall infiltration and reservoir level changes. The uncertainties discussed include those involved in the selection of design soil parameters and design-loading combinations, determination of pore-water pressures and potential slip surfaces, and use of analysis models. Finally a design scenario tree is developed to evaluate the landslide risk and to assist risk-investment decisions
Advanced methodology for storm sewer design—phase II
This report describes further development of computer models for determining the diameter, slope and elevations of each pipe in a storm drainage system in which the layout and manhole locations are specified. The design procedure is based on a least-cost criterion and utilizes discrete differential dynamic programming as the search technique. In this phase of the study a detention storage capability has been added to the model using two approaches. The first approach requires the specification of a maximum allowable outflow and computes the required storage. The second approach determines the storage volume such that the sum of the storage and pipe system costs is a minimum. The procedure for computation of expected damage costs has been changed to reflect the variation of flood damage with flood volume. Also a surface runoff component has been added. This option uses the hydrograph generation portion of the Illinois Urbana Drainage Area Simulator model. Improved cost specification methods as well as flexible pipe elevation constraint capabilities have been added. The new developments are illustrated using two example basins.U.S. Department of the InteriorU.S. Geological SurveyOpe
Fabrication and superconductivity of NaxTaS2 crystals
In this paper we report the growth and superconductivity of
crystals. The structural data deduced from X-ray diffraction pattern shows that
the sample has the same structure as . A series of crystals with
different superconducting transition temperatures () ranging from 2.5 K to
4.4 K were obtained. It is found that the rises with the increase of
content determined by Energy-Dispersive x-ray microanalysis(EDX) of Scanning
Electron Microscope (SEM) on these crystals. Compared with the resistivity
curve of un-intercalated sample ( = 0.8 K, 70
K), no signal of charge density wave (CDW) was observed in samples
and . However, in some samples with lower
, the CDW appears again at about 65 K. Comparison between the anisotropic
resistivity indicates that the anisotropy becomes smaller in samples with more
intercalation (albeit a weak semiconducting behavior along c-axis) and
thus higher . It is thus concluded that there is a competition between the
superconductivity and the CDW. With the increase of sodium content, the rise of
in is caused mainly by the suppression to the CDW in
, and the conventional rigid band model for layered dichalcogenide
may be inadequate to explain the changes induced by the slight intercalation of
sodium in .Comment: 8 pages, 13 figures, To appear in Physical Review
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The cumulative effects of known susceptibility variants to predict primary biliary cirrhosis risk.
Multiple genetic variants influence the risk for development of primary biliary cirrhosis (PBC). To explore the cumulative effects of known susceptibility loci on risk, we utilized a weighted genetic risk score (wGRS) to evaluate whether genetic information can predict susceptibility. The wGRS was created using 26 known susceptibility loci and investigated in 1840 UK PBC and 5164 controls. Our data indicate that the wGRS was significantly different between PBC and controls (P=1.61E-142). Moreover, we assessed predictive performance of wGRS on disease status by calculating the area under the receiver operator characteristic curve. The area under curve for the purely genetic model was 0.72 and for gender plus genetic model was 0.82, with confidence limits substantially above random predictions. The risk of PBC using logistic regression was estimated after dividing individuals into quartiles. Individuals in the highest disclosed risk group demonstrated a substantially increased risk for PBC compared with the lowest risk group (odds ratio: 9.3, P=1.91E-084). Finally, we validated our findings in an analysis of an Italian PBC cohort. Our data suggested that the wGRS, utilizing genetic variants, was significantly associated with increased risk for PBC with consistent discriminant ability. Our study is a first step toward risk prediction for PBC
Advanced methodologies for design of storm sewer systems
This report describes the development of a series of computer models capable of determining the diameter, slope and crown elevations of each sewer in a storm drainage system in which the layout and manhole locations are predetermined. The criterion for design decisions is the generation of a least-cost system. The basis for all of the models is the application of discrete differential dynamic programing (DDDP) as the optimization tool. Two important concepts are introduced as optimal model components: hydrograph routing and risks and uncertainties in designs. Three routing procedures are adopted, each with its own advantages. Expected flood damage costs are evaluated through the analysis of numerous risks and uncertainties associated with the design. This analysis permits the estimation of the probability of exceeding the capacity and the corresponding expected assessed damage of any sewer in the system. The expected damage cost is added to the installation cost to obtain the total cost which is then minimized in the DDDP procedure. Two example sewer systems are used as a basis for illustrating different aspects of the various least-cost design models and developing user guidelines.U.S. Department of the InteriorU.S. Geological SurveyOpe
Cellular uptake and imaging studies of gadolinium-loaded single-walled carbon nanotubes
postprintThe 18th Joint Annual Meeting of ISMRM-ESMRMB, Stockholm, Sweden, 1-7 May 2010
IMPAIRED RIGHT VENTRICULAR MECHANICS IS THE BEST PREDICTOR OF DECREASED PEAK EXERCISE CAPACITY IN CHRONIC SYSTOLIC HEART FAILURE PATIENTS
BURDEN OF ATRIAL FIBRILLATION AND POOR RATE CONTROL DETECTED BY CONTINUOUS MONITORING VIA IMPLANTED DEVICES IDENTIFIES WHEN A PATIENT IS AT RISK FOR HEART FAILURE HOSPITALIZATION
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