| association between genotype and drug resistance profiles of mycobacterium tuberculosis strains circulating in china in a national drug resistance survey. | we describe the population structure of a representative collection of 3,133 mycobacterium tuberculosis isolates, collected within the framework of a national resistance survey from 2007 in china. genotyping data indicate that the epidemic strains in china can be divided into seven major complexes, of which 92% belonged to the east asian (mainly beijing strains) or the euro-american lineage. the epidemic beijing strains in china are closely related to the beijing b0/w148 strain earlier described ... | 2017 | 28333978 |
| low induction of proinflammatory cytokines parallels evolutionary success of modern strains within the mycobacterium tuberculosis beijing genotype. | one of the most widespread clades of mycobacterium tuberculosis worldwide, the beijing genotype family, consists of ancient (atypical) and modern (typical) strains. modern beijing strains outcompete ancient strains in terms of prevalence, while reserving a higher degree of genetic conservation. we hypothesize that their selective advantage lies in eliciting a different host immune response. bead-disrupted lysates of a collection of different m. tuberculosis strains of the modern (n = 7) or ancie ... | 2013 | 23897611 |
| gaseous emissions from compressed natural gas buses in urban road and highway tests in china. | the natural gas vehicle market is rapidly developing throughout the world, and the majority of such vehicles operate on compressed natural gas (cng). however, most studies on the emission characteristics of cng vehicles rely on laboratory chassis dynamometer measurements, which do not accurately represent actual road driving conditions. to further investigate the emission characteristics of cng vehicles, two cng city buses and two cng coaches were tested on public urban roads and highway section ... | 2016 | 27745664 |
| voc from vehicular evaporation emissions: status and control strategy. | vehicular evaporative emissions is an important source of volatile organic carbon (voc), however, accurate estimation of emission amounts and scientific evaluation of control strategy for these emissions have been neglected outside of the united states. this study provides four kinds of basic emission factors: diurnal, hot soak, permeation, and refueling. evaporative emissions from the euro 4 vehicles (1.6 kg/year/car) are about four times those of u.s. vehicles (0.4 kg/year/car). closing this e ... | 2015 | 26599318 |
| pm₂.₅ emissions from light-duty gasoline vehicles in beijing, china. | as stricter standards for diesel vehicles are implemented in china, and the use of diesel trucks is forbidden in urban areas, determining the contribution of light-duty gasoline vehicles (ldgvs) to on-road pm2.5 emissions in cities is important. additionally, in terms of particle number and size, particulates emitted from ldgvs have a greater health impact than particulates emitted from diesel vehicles. in this work, we measured pm2.5 emissions from 20 ldgvs in beijing, using an improved combine ... | 2014 | 24810889 |
| on-road pollutant emission and fuel consumption characteristics of buses in beijing. | on-road emission and fuel consumption (fc) levels for euro iii and iv buses fueled on diesel and compressed natural gas (cng) were compared, and emission and fc characteristics of buses were analyzed based on approximately 28,700 groups of instantaneous data obtained in beijing using a portable emissions measurement system (pems). the experimental results revealed that nox and pm emissions from cng buses were decreased by 72.0% and 82.3% respectively, compared with euro iv diesel buses. similarl ... | 2011 | 21520811 |
| real-world operation conditions and on-road emissions of beijing diesel buses measured by using portable emission measurement system and electric low-pressure impactor. | on-road measurement is an effective method to investigate real-world emissions generated from vehicles and estimate the difference between engine certification cycles and real-world operating conditions. this study presents the results of on-road measurements collected from urban buses which propelled by diesel engine in beijing city. two widely used euro iii emission level buses and two euro iv emission level buses were chosen to perform on-road emission measurements using portable emission mea ... | 2011 | 21295821 |
| on-road vehicle emission control in beijing: past, present, and future. | beijing, the capital of china, has experienced rapid motorization since 1990; a trend that is likely to continue. the growth in vehicles and the corresponding emissions create challenges to improving the urban air quality. in an effort to reduce the impact of vehicle emissions on urban air quality, beijing has adopted a number of vehicle emission control strategies and policies since the mid 1990 s. these are classified into seven categories: (1) emission control on new vehicles; (2) emission co ... | 2011 | 20690777 |
| [effects of fuel properties on the performance of a typical euro iv diesel engine]. | with the purpose of establishing diesel fuel standard for china national 4th emission standard, as one part of beijing "auto-oil" programme, engine performance test has been done on a typical euro iv diesel engine using eight diesel fuels with different fuel properties. test results show that, fuel properties has little effect on power, fuel consumption, and in-cylinder combustion process of tested euro iv diesel engine; sulfate in pm and gaseous so2 emissions increase linearly with diesel sulfu ... | 2008 | 19068662 |
| characterization of in-use light-duty gasoline vehicle emissions by remote sensing in beijing: impact of recent control measures. | china's national government and beijing city authorities have adopted additional control measures to reduce the negative impact of vehicle emissions on beijing's air quality. an evaluation of the effectiveness of these measures may provide guidance for future vehicle emission control strategy development. in-use emissions from light-duty gasoline vehicles (ldgvs) were investigated at five sites in beijing with remote sensing instrumentation. distance-based mass emission factors were derived with ... | 2007 | 17912926 |
| occasional series: lupus around the world systemic lupus erythematosus research in the asia-pacific region: a co-ordinated and co-operative approach. | research on sle in the asia-pacific region is presently conducted separately in various centres. a co-ordinated and co-operative approach is advocated for a long-term, prospective study on lupus patients in this region. a pilot study involving beijing, shanghai and singapore has been initiated with the intention of expanding it to a larger study, involving up to 1000 newly diagnosed lupus patients who will be followed up for 10 years. the study design and term definitions are patterned after tha ... | 1996 | 8646219 |