Background/Aims: Depending on the specific definition, acute kidney injury (AKI) occurs in 7–40% of patients undergoing cardiac surgery. Even small changes in serum creatinine (SCr) levels are associated with increased mortality after cardiac surgery. However, there are no current methods for preventing AKI after cardiac surgery. Erythropoietin (EPO) has been shown to elicit tissue-protective effects in various experimental models. In this pilot trial, we evaluated the effectiveness of EPO in the prevention of AKI after coronary artery bypass grafting (CABG). Methods: 71 patients scheduled for elective CABG randomly received either 300 U/kg of EPO or saline intravenously before surgery. AKI was defined as a 50% increase in SCr levels over baseline within the first 5 postoperative days. Estimated glomerular filtration rate (eGFR) was calculated from the Cockcroft-Gault equation. Results: Of 71 patients, 13 developed postoperative AKI: 3 of the 36 patients in the EPO group (8%) and 10 of the 35 patients in the placebo group (29%; p = 0.035). The increase in postoperative SCr concentration and the decline in postoperative eGFR were significantly lower in the EPO group than in the placebo group. Conclusions: In our small, pilot trial, prophylactic administration of EPO prevents AKI and improves postoperative renal function. These data are preliminary and require confirmation in a larger clinical trial.

[1] Concentrations of elemental carbon (EC), carbon monoxide (CO), and carbon dioxide (CO 2 ) were measured in Beijing between 2005 and 2006. EC was measured every hour with a semicontinuous thermal optical analyzer. The observed concentrations were rather uniform over a distance of about 50 km from the observation site. The annual average concentrations of EC and CO were 6.9 mgC m À3 and 1120 parts per billion by volume, respectively. The concentrations of these species increased with decreasing near-surface wind speed (WS). The slopes of the CO-CO 2 , EC-CO 2 , and EC-CO correlations are used to estimate major EC and CO sources. In the weak wind regime (WS 2.0 m s À1 ), the median EC, DEC/DCO 2 , and DEC/DCO (except for winter) increased in the late evening and remained high until early morning. The traffic of heavy duty diesel trucks during nighttime was about 20 times higher than that during daytime. These results indicate a dominant contribution of exhaust from diesel vehicles to the nighttime EC. In winter, the nighttime CO and DCO/DCO 2 ratio were largely higher than those in the other seasons. The most likely cause is the increase in the CO emissions from the exhaust of gasoline vehicles at low temperature. The DEC/DCO 2 ratio in winter was lower than that in fall, indicating no significant additional EC emissions. The diurnal variations of EC, CO, CO 2 , and DEC/DCO were similar between weekdays and weekends. The slopes of the CO-CO 2 -EC correlations are compared with the CO-CO 2 -EC ratios derived from a published emission inventory in the Beijing area.

In principle, mass concentrations of black carbon (BC) (M BC)

Ground‐based measurements of aerosol and trace gases were conducted at a rural site in Beijing in the summer of 2006 as a part of the Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing 2006). The size‐resolved chemical composition of submicron aerosol was measured using an Aerodyne quadrupole aerosol mass spectrometer (AMS). The data obtained from 15 August to 10 September 2006 are presented. Meteorological analysis shows that the measurement period can be characterized as a cycle of low wind speed periods over the course of a few days (stagnant periods) followed by rapid advection of clean air from the north/northwest mostly due to passage of a midlatitude cyclone. Mass concentrations of total measured aerosol with diameters less than 1 μm (total PM1), which is defined as the sum of elemental carbon and nonrefractory components measured by the AMS, were highly variable, ranging from ∼2 to ∼100 μg m−3. Large variability of the PM1 composition and drastic changes in the sulfate (SO42−) size distribution were observed to be associated with the cycle of stagnant periods and advection of clean air, indicating that both chemical and physical properties of aerosols were significantly altered on a time scale of a few days. We have found the dominance of organic aerosol at lower total PM1 mass loadings and that of SO42− at higher mass loadings, which may have important implications for the PM control strategy in Beijing. Possible factors affecting the evolution of the mass concentration and size distribution of SO42− are discussed.

[1] Organic carbon (OC) and elemental carbon (EC) in PM 2.5 were measured hourly with a semicontinuous thermal-optical analyzer in Beijing, China, during four seasons from November 2005 to October 2006. The average OC concentrations measured at Peking University (PKU) site in urban Beijing were 20 ± 19, 12 ± 7, 10 ± 5, and 18 ± 11 mgC/m 3 in winter, spring, summer, and autumn, respectively. Distinct seasonal and diurnal patterns of OC were observed, and their concentrations were significantly influenced by the seasonal and diurnal changes in sources, emission rates, and mesoscale meteorology. The impacts of meteorological parameters such as wind and precipitation on OC and EC concentrations are also discussed. OC and EC concentrations were found to be well correlated in winter, spring, and autumn, indicating their common origins, while their correlation was poorer in summer, especially in the afternoon, indicating that the influence of secondary organic carbon (SOC) was significant for this period. SOC concentrations were estimated by using the EC-tracer method as about 2.6 ± 3.1, 2.8 ± 2.4, 4.5 ± 2.9, and 4.1 ± 4.0 mgC/m 3 , accounting for 19%, 27%, 45%, and 23% of total organic carbon in winter, spring, summer, and autumn, respectively. This result showed that the relative contribution of SOC to OC in PM 2.5 at this urban location was only comparable to that of primary organic carbon (POC) to OC in summer, while in the other three seasons, OC was dominated by POC.