Evaluating Real Driving Emissions of Compressed Natural Gas Taxis in Chongqing, China—A Typical Mountain Cities

Compressed natural gas (CNG) taxis represent the most ubiquitous and dynamically active passenger vehicles in urban settings. The pollutant emission characteristics of in-use CNG taxis driving on a typical mountain city before and after three-way catalyst (TWC) replacement was examined using a modular on-board portable emissions measurement system (PEMS), the OBS-ONE developed by Horiba. The results showed that the exhaust NO of CNG taxis equipped with deactivation TWC exceeded the emission limits, even higher than gasoline vehicles. The high emission rate of CNG taxis is mainly concentrated on road slopes between a 2% and 6% gradient and a deceleration rate in the interval of [0.5, 4], respectively, which results in higher emissions from CNG taxis traveling in the mountain city of Chongqing than other cities and vehicles. Moreover, the pollutant emission rates of the in-use CNG taxis were highly correlated with the velocity and the vehicle specific power (VSP). After a new TWC replacement, the emission factors of carbon monoxide (CO), total hydrocarbons (THC), nitrogen oxides (NOx), and particle number (PN) decreased by 85.21–89.11%, 68.71–85.49%, 60.91–81.11%, and 62.26–68.39%, respectively. Our results will provide guidance for urban environments to carry out the comprehensive management of in-use vehicles and emphasize the importance of TWC replacement for CNG taxis

High Resistance to Azithromycin in Clinical Samples from Patients with Sexually Transmitted Diseases in Guangxi Zhuang Autonomous Region, China

<div><p>Azithromycin is used as an alternative medicine in patients with syphilis who are intolerant to penicillin. Nevertheless, the report of treatment failure of azithromycin for patients with syphilis has raised concerns in China in the past years. In this study, 178 patients with early syphilis, who were treated in sexually transmitted infections clinics in four cities in Guangxi Zhuang Autonomous Region were enrolled to investigate the regional prevalence of <i>Treponema pallidum</i> strain resistant to azithromycin. Nested PCR was performed to amplify the 23S ribosomal RNA (<i>23SrRNA</i>) gene. The point mutation of A2058G in <i>23SrRNA</i>, which confers <i>Treponema pallidum</i> resistance to azithromycin, was measured by endonuclease digestion of PCR amplification products using <i>Mbo</i>II. A2058G point mutation was detected in 91.0% (162/178; 95% CI, 86.8%, 95.2%) of the specimens, but no difference in prevalence of azithromycin resistance was found between the patients who had taken antibiotics before enrollment and the patients who had not (91.8% vs. 89.4%), nor between the patients with and without past sexually transmitted infections (87.1% vs. 93.1%). We concluded that azithromycin may not be suitable for syphilis as a treatment option in Guangxi Zhuang Autonomous Region because of the extremely high prevalence of resistance in the general syphilis population.</p></div

Primers used in the study.

<p>Primers used in the study.</p

History of STIs and macrolide use by patients (n = 178).

<p>History of STIs and macrolide use by patients (n = 178).</p

Demographic characteristics of patients diagnosed with syphilis.

<p>Demographic characteristics of patients diagnosed with syphilis.</p

Soluble Urokinase Plasminogen Activator Receptor is Associated with Coronary Artery Calcification and Cardiovascular Disease in Patients Undergoing Hemodialysis

Background/Aims: Cardiovascular disease (CVD) is an important cause of morbidity and mortality in hemodialysis patients. Vascular calcification is thought to play an important role in causing CVD. Soluble urokinase plasminogen activator receptor (suPAR) is a biomarker strongly predictive of cardiovascular outcomes in the pathogenesis of diabetic patients with renal disease treated with hemodialysis. We investigated the relationship between suPAR and coronary artery calcification (CAC) in patients undergoing maintenance hemodialysis. Methods: A total of 99 adult hemodialysis patients were enrolled in this study. Plasma samples were analyzed for suPAR with an enzyme-linked immunosorbent assay and the CAC score was determined with multidetector computed tomography. The occurrence of cardiovascular events and all-cause mortality during follow-up were recorded from January 1, 2010 to June 1, 2016. Results: In 99 patients treated with maintenance hemodialysis, 91 (91.9%) had varying degrees of CAC, and suPAR correlated positively with the CAC score in a Spearman analysis. In a mean follow-up period of 33 months, 36 patients (36.4%) experienced at least one cardiovascular event. When the quartiles of suPAR concentrations were used as the cutoff points for a subgroup analysis, the incidence of CVD and all-cause mortality was much higher in the higher quartiles of suPAR. In a univariate Cox regression analysis, high suPAR was a risk factor for CVD and all-cause mortality. Conclusion: suPAR is associated with the CAC score and is a risk factor for new-onset CVD in patients undergoing hemodialysis