73 research outputs found
Emission Control Cost-Effectiveness of Alternative-Fuel Vehicles
Although various legislation and regulations have been adopted to promote the use of alternative-fuel vehicles for curbing urban air pollution problems, there is a lack of systematic comparisons of emission control cost-effectiveness among various alternative-fuel vehicle types. In this paper, life-cycle emission reductions and life-cycle costs were estimated for passenger cars fueled with methanol, ethanol, liquified petroleum gas, compressed natural gas, and electricity. Vehicle emission estimates included both exhaust and evaporative emissions for air pollutants of hydrocarbon, carbon monoxide, nitrogen oxides, and air-toxic pollutants of benzene, formaldehyde, 1,3-butadiene, and acetaldehyde. Vehicle life-cycle cost estimates accounted for vehicle purchase prices, vehicle life, fuel costs, and vehicle maintenance costs.Emission control cost-effectiveness presented in dollars per ton of emission reduction was calculated for each alternative-fuel vehicle type from the estimated vehicle life-cycle emission reductions and costs. Among various alternative-fuel vehicle types, compressed natural gas vehicles are the most cost-effective vehicle type in controlling vehicle emissions. Dedicated methanol vehicles are the next most cost-effective vehicle type. The cost-effectiveness of electric vehicles depends on improvements in electric vehicle battery technology. With low-cost, high-performance batteries, electric vehicles are more cost-effective than methanol, ethanol, and liquified petroleum gas vehicles
Human Circulating MicroRNA-1 and MicroRNA-126 as Potential Novel Indicators for Acute Myocardial Infarction
Circulating miRNAs have been shown as promising biomarkers for various pathologic conditions. The aim of this study was to clarify that circulating miR-1 and miR-126 in human plasma might be useful as biomarkers in acute myocardial infarction (AMI). In our study, after pre-test, two candidate miRNAs were detected by using real-time RT-PCR. Cardiac troponin I (cTnI) concentrations were measured by ELISA assay in plasma from patients with AMI (n=17) and healthy subjects (n=25), simultaneously. Increased miR-1 and decreased miR-126 in plasma from patients with AMI after the onset of symptoms compared with healthy subjects were found. A remarkable finding in this study is that miR-1, miR-126 and cTnI expression levels exhibited the same trend. Our results suggest that the plasma concentrations of miR-1 and miR-126 may be useful indicators for AMI
Ξ²-AR Blockers Suppresses ER Stress in Cardiac Hypertrophy and Heart Failure
Long-term Ξ²-adrenergic receptor (Ξ²-AR) blockade reduces mortality in patients with heart failure. Chronic sympathetic hyperactivity in heart failure causes sustained Ξ²-AR activation, and this can deplete Ca(2+) in endoplasmic reticulum (ER) leading to ER stress and subsequent apoptosis. We tested the effect of Ξ²-AR blockers on ER stress pathway in experimental model of heart failure.ER chaperones were markedly increased in failing hearts of patients with end-stage heart failure. In Sprague-Dawley rats, cardiac hypertrophy and heart failure was induced by abdominal aortic constriction or isoproterenol subcutaneous injection. Oral Ξ²-AR blockers treatment was performed in therapy groups. Cardiac remodeling and left ventricular function were analyzed in rats failing hearts. After 4 or 8 weeks of banding, rats developed cardiac hypertrophy and failure. Cardiac expression of ER chaperones was significantly increased. Similar to the findings above, sustained isoproterenol infusion for 2 weeks induced cardiac hypertrophy and failure with increased ER chaperones and apoptosis in hearts. Ξ²-AR blockers treatment markedly attenuated these pathological changes and reduced ER stress and apoptosis in failing hearts. On the other hand, Ξ²-AR agonist isoproterenol induced ER stress and apoptosis in cultured cardiomyocytes. Ξ²-AR blockers largely prevented ER stress and protected myocytes against apoptosis. And Ξ²-AR blockade significantly suppressed the overactivation of CaMKII in isoproterenol-stimulated cardiomyocytes and failing hearts in rats.Our results demonstrated that ER stress occurred in failing hearts and this could be reversed by Ξ²-AR blockade. Alleviation of ER stress may be an important mechanism underlying the therapeutic effect of Ξ²-AR blockers on heart failure
ER Stress Negatively Modulates the Expression of the miR-199a/214 Cluster to Regulates Tumor Survival and Progression in Human Hepatocellular Cancer
Background: Recent studies have emphasized causative links between microRNAs (miRNAs) deregulation and tumor development. In hepatocellular carcinoma (HCC), more and more miRNAs were identified as diagnostic and prognostic cancer biomarkers, as well as additional therapeutic tools. This study aimed to investigate the functional significance and regulatory mechanism of the miR-199a2/214 cluster in HCC progression. Methods and Findings: In this study, we showed that miR-214, as well as miR-199a-3p and miR-199a-5p levels were significantly reduced in the majority of examined 23 HCC tissues and HepG2 and SMMC-7721 cell lines, compared with their nontumor counterparts. To further explore the role of miR-214 in hepatocarcinogenesis, we disclosed that the ER stressinduced pro-survival factor XBP-1 is a target of miR-214 by using western blot assay and luciferase reporter assay. Reexpression of miR-214 in HCC cell lines (HepG2 and SMMC-7721) inhibited proliferation and induced apoptosis. Furthermore, ectopic expression of miR-214 dramatically suppressed the ability of HCC cells to form colonies in vitro and to develop tumors in a subcutaneous xenotransplantation model of the BALB/c athymic nude mice. Moreover, reintroduction of XBP-1s attenuated miR-214-mediated suppression of HCC cells proliferation, colony and tumor formation. To further understand the mechanism of the miR-199a/214 cluster down-expression in HCC, we found that thapsigargin (TG) and tunicamycin (TM) or hypoxia-induced unfolded protein response (UPR) suppresses the expression of the miR-199a/21
Highway Electrification: An Exploration of Energy Supply Implications
The objective of this preliminary report is to explore the energy supply opportunities and implications of electrifying highways. An important assumption in this report is that the technology and general cost structure for generating and storing electricity does not change significantly in the future. In other words, we ignore the possible use of super conductive materials to store electricity during off-peak times, which, if feasible, would greatly reduce average electricity costs. A future report will examine the opportunities and implications of breakthroughs in superconductivity.The report is organized as follows. First, the relationship between transportation and electricity demand patterns are investigated. These relationships are then explored for different regions of the country. With this background, we then identify the implications of electrifying highway transportation for the electricity industry, including an analysis of energy supply considerations
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