A prediction model for new-onset atrial fibrillation following coronary artery bypass graft surgery: A multicenter retrospective study.

Objective: Developing and assessing a risk prediction model of postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG), and aims to provide a reference for the prediction and prevention. Design: A retrospective case-control study. Setting: Three major urban teaching and university hospitals and tertiary referral centers. Participants: consecutive patients undergoing CABG. Interventions: The study was retrospective and no interventions were administered to patients. Measurements and main results: In the study, the overall new-onset POAF prevalence was approximately 28%. A prediction model for POAF with nine significant indicators was developed, and identified new predictors of POAF: left ventricular end diastolic diameter (LVEDD), intraoperative defibrillation, and intraoperative temporary pacing lead implantation. The model had good discrimination in both the derivation and validation cohorts, with the area under the receiver operating characteristic curves (AUCs) of 0.621 (95% CI = 0.602-0.640) and 0.616 (95% CI = 0.579-0.651), respectively, and showed good calibration. Compared with CHA2DS2-VASc, HATCH score, and the prediction model of POAF after CABG developed based on a small sample of clinical data from a single center in China, the model in this study had better discrimination. Conclusion: We have developed and validated a new prediction model of POAF after CABG using multicenter data that can be used in the clinic for early identification of high-risk patients of POAF, and to help effectively prevent POAF in postoperative patients.

Cannabinoid Receptor Agonist WIN55, 212-2 Attenuates Injury in the Hippocampus of Rats after Deep Hypothermic Circulatory Arrest.

OBJECTIVES: Postoperative neurological deficits remain a challenge in cardiac surgery employing deep hypothermic circulatory arrest (DHCA). This study aimed to investigate the effect of WIN55, 212-2, a cannabinoid agonist, on brain injury in a rat model of DHCA. METHODS: Twenty-four male Sprague Dawley rats were randomly divided into three groups: a control group (which underwent cardiopulmonary bypass (CPB) only), a DHCA group (CPB with DHCA), and a WIN group (WIN55, 212-2 pretreatment before CPB with DHCA). Histopathological changes in the brain were evaluated by hematoxylin-eosin staining. Plasma levels of superoxide dismutase (SOD) and proinflammatory cytokines including interleukin (IL)-1ß, IL-6, and tumor necrosis factor-alpha (TNF-a) were determined using an enzyme-linked immunosorbent assay (ELISA). The expression of SOD in the hippocampus was detected by Western blot and immunofluorescence staining. Levels of apoptotic-related protein caspase-3 and type 1 cannabinoid receptor (CB1R) in the hippocampus were evaluated by Western blot. RESULTS: WIN55, 212-2 administration attenuated histopathological injury of the hippocampus in rats undergoing DHCA, associated with lowered levels of IL-1ß, IL-6, and TNF-α (p < 0.05, p < 0.001, and p < 0.01, vs. DHCA, respectively) and an increased level of SOD (p < 0.05 vs. DHCA). WIN55, 212-2 treatment also increased the content of SOD in the hippocampus. The protein expression of caspase-3 was downregulated and the expression of CB1R was upregulated in the hippocampus by WIN55, 212-2. CONCLUSIONS: the administration of WIN55, 212-2 alleviates hippocampal injury induced by DHCA in rats by regulating intrinsic inflammatory and oxidative stress responses through a CB1R-dependent mechanism.

Comparison of in-hospital outcomes after coronary artery bypass graft surgery in elders and younger patients: a multicenter retrospective study.

OBJECTIVES: We aimed to identify in-hospital outcomes in young (≤ 65 years) and old (> 65 years) patients after coronary artery bypass grafting (CABG) by analyzing the effect of age on adverse events after on-pump or off-pump CABG. METHODS: Patients older than 65 years were defined as older patients and others were defined as younger patients. The qualitative data were compared by chi-square or Fisher's exact tests. The quantitative data were compared by the two-sample independent t-test or Mann-Whitney U test. Multifactor binary logistic regression was used to control for confounders and to investigate the effect of age on dichotomous outcome variables such as death. RESULTS: In the on-pump CABG population, the postoperative in-hospital mortality, the incidence of postoperative symptomatic cerebral infarction (POSCI) and postoperative atrial fibrillation (POAF) was higher in older patients than in younger patients (P value < 0.05), and age > 65 years was associated with postoperative in-hospital mortality (OR = 2.370, P value = 0.031), POSCI (OR = 5.033, P value = 0.013), and POAF (OR = 1.499, P value < 0.001). In the off-pump CABG population, the incidence of POAF was higher in older patients than in younger patients (P value < 0.05), and age > 65 years was associated with POAF (OR = 1.392, P value = 0.011). CONCLUSION: In-hospital outcomes after CABG are strongly influenced by age. In on-pump CABG, the risk of postoperative death, POSCI, and POAF was higher in older patients, and in off-pump CABG, the risk of POAF was higher in older patients.

Association of LDL to HDL ratio with new-onset atrial fibrillation after on-pump coronary artery bypass graft surgery.

OBJECTIVE: This study aims to analyze the association between preoperative LDL/HDL ratio and new-onset atrial fibrillation (AF) after on-pump coronary artery bypass grafting (on-pump CABG), evaluate the clinic value of preoperative LDL/HDL ratio to identify postoperative rhythm. METHODS: A retrospective study of consecutive patients (n = 2052) who underwent on-pump CABG at TEDA International Cardiovascular Hospital (Tianjin, China), from June 1, 2020, to December 30, 2021, was conducted. The association between preoperative LDL/HDL and new-onset POAF was analyzed by Lowess curve and univariate logistic regression. The receiver operating characteristic curve (ROC) and area under the curve (AUC) were used to evaluate the identification capacity of preoperative LDL/HDL level for new-onset POAF. RESULTS: In studied populations, the incidence of new-onset POAF was about 29.24%. The lowess curve showed that the association between preoperative LDL/HDL ratio and POAF after on-pump CABG was similar to a linear relationship. With the increasement of preoperative LDL/HDL ratio, the incidence of POAF increased simultaneously. ROC analysis showed that preoperative LDL/HDL ratio could identify postoperative arrhythmia after on-pump CABG (AUC = 0.569,95% CI = 0.529-0.608, P = 0.006) among female patients, the best preoperative LDL/HDL ratio cutoff of 2.11, which was considered a predictive factor of incident POAF, showed a sensitivity of 83.60% (95% CI = 0.775-0.886) and a specificity of 30.02% (95% CI = 0.257-0.346). CONCLUSION: Preoperative LDL/HDL ratio is associated with new-onset POAF, but there is a difference in different sex. Preoperative LDL/HDL level can help to identify postoperative rhythm in females.

[Seasonal variation of carcinogenic heavy metals in PM2.5 and source analysis in Beijing].

During April, July, October 2009 and January 2010, daily (24-h average) PM2.5 samples were collected at urban sites in Beijing and 29 metal elements were analyzed by the ICP-MS. The characteristics of 7 carcinogenic heavy metal mass concentrations, enrichment, and possible sources were discussed. The annual average concentrations of As, Cd, Co, Cr, Ni, Pb and Se were (11.6 +/- 14.0), (2.6 +/- 2.4), (1.0 +/- 0.7), (11.3 +/- 9.4), (4.0 +/- 2.4), (142.5 +/- 98.9) and (3.3 +/- 2.2) ng m(-3), respectively. Only annual average concentration of As exceeded WHO standard by a factor of 0.8. Higher enrichment factors of As, Cd, Pb and Se were found and their enrichment factors exceeded 500. Their enrichment factors in summer were much higher than those in other seasons. The local coal combustion and vehicle exhaust should be the dominant sources for the above four carcinogenic heavy metals in spring, autumn and winter, while regional transportation contributed more in summer.

[Characteristics of haze and its impact factors in four megacities in China during 2006-2009].

The meteorological and environmental data including visibility, SO2, NO2 and PM10 were collected in four major megacities (Beijing, Shanghai, Guangzhou and Chengdu) in the years 2006-2009. Based on the data, seasonal and annual variations of the haze frequency and the key impact factors were discussed. The results indicated that the highest frequencies of haze occurred in summer, winter, spring and autumn for Beijing, Shanghai, Guangzhou and Chengdu, respectively. The trends of haze frequency decreased in Beijing and Guangzhou, while increased in Shanghai and Chengdu during the studied period. The PM10 concentration and relative humidity were the key factors for visibility degradation in the four megacities. The variation of visibility was sensitive to relative humidity in Beijing, to PM10 in Shanghai and Guangzhou, and to both in Chengdu.

[Characterization of chemical compositions in PM2.5 and its impact on hazy weather during 16th Asian Games in Guangzhou].

Aerosol samples for PM2.5 were collected days and nights from 4 to 30 November 2010 in Guangzhou. The concentrations of organic carbon, element carbon, and water-solubility ions of all particle samples were determined by thermal/optical carbon analyzer and ion chromatography, respectively. In-situ online PM,, mass concentrations, light extinction coefficients (bext), and selected meteorological parameters for this period were also measured. Temporal variation of PM,, mass concentrations and its relationship with bext were discussed, and bext was reconstructed by revised IMPROVE formula. The results showed that the average mass concentration ol PM2.5 was (77.0 +/- 24.4) microg.m-3 during the Asian Games period, which was 27.8% lower than that of the period before Asian Games. PM2.5 and relative humidity were the dominant factors contributing to hazy weather. The average value of bx, was 418 Mm-1 during the Asian Games period, which was 28.3% lower than that of the period before Asian Games. The major contributors to bext included (NH4) 2SO4, POM, and LAC, which accounted for 87.0% of bext during the Asian Games period. A series of stringent air quality control measures were implemented by the Guangzhou Municipal Government and other cooperative cities, which greatly alleviated the hazy weathers in Guangzhou urban area during the Asian Games period.

[Reconstructed ambient light extinction coefficient and its contribution factors in Beijing in January, 2010].

Aerosol samples for PM2.5 were collected from 1st January to 31st January 2010, in Beijing. The concentrations of organic carbon, elemental carbon, water-solubile ions and soil elements of all particle samples were determined by thermal/optical carbon analyzer, ion chromatography and X-ray fluorescence spectrometer, respectively. The scattering coefficients (b(sp)), absorbing coefficients (b(ap)) and meteorological parameters for this period were also measured. Ambient light extinction coefficients were reconstructed by IMPROVE formula and were compared with measured light extinction coefficients. The results showed that the average mass concentration of PM2.5 was (144.3 +/- 89.1) microg x m(-3) during campaigning period. The average values of measured b(ap), b(sp) and extinction coefficient (b(ext)) were (67.4 +/- 54.3), (328.5 +/- 353.8) and (395.9 +/- 405.2) Mm(-1), respectively. IMPROVE formula is suitable for source apportionment of light extinction coefficient in campaign period. The average value of calculated b'(ext) was (611 +/- 503) Mm(-1) in January, 2010. The major contributors to ambient light extinction coefficients included (NH4) 2SO4 (24.6%), NH4NO3 (11.6%), OM (45.5%), EC (11.9%) and FS (6.4%), respectively.

[Characterization of water-soluble inorganic ions in PM2.5 and PM1.0 in summer in Guangzhou].

PM2.5 and PM1.0 samples were collected simultaneously during July of 2008 in Guangzhou. The concentrations of water-soluble inorganic ions (Na+, NH4+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, and SO4(2-)) were determined by ion chromatography. Meteorological parameters, atmospheric scattering, visibility, and concentrations of trace gases (SO2, NO2, and O3) for this period were also recorded. The results showed the total water-soluble inorganic ions concentrations were (25.5 +/- 10.9) microg x m(-1) and (22. 7 +/- 10.5) microg x m(-3) in PM2.5 and PM1.0, which occupied (47.9 +/- 4.3)% and (49.3 +/- 4.3)% of PM mass respectively. Sulfate was the most abundant ion and contributed (25.8 +/- 4.0)% of PM2.5 mass and (27.5 +/- 4.5)% of PM1.0 mass respectively. High temperature and high ozone level favored the formation of sulfate from sulfur dioxide, while the high relative humidity favored the formation of nitrate were observed. Moreover, sulfate, nitrate, and ammonium in PM2.5 and PM1.0 had great impact on the scattering coefficient and visibility degradation.

Carbonaceous aerosols in PM10 and pollution gases in winter in Beijing.

An intensive observation of organic carbon (OC) and elemental carbon (EC) in PM10 and gaseous materials (SO2, CO, and O3) was conducted continuously to assess the characteristics of wintertime carbonaceous aerosols in an urban area of Beijing, China. Results showed that the averaged total carbon (TC) and PM10 concentrations in observation period are 30.2 +/- 120.4 and 172.6 +/- 198.3 microg/m3, respectively. Average OC concentration in nighttime (24.9 +/- 19.6 microg/m3) was 40% higher than that in daytime (17.7 +/- 10.9 microg/m3). Average EC concentrations in daytime (8.8 +/- 15.2 microg/m3) was close to that in nighttime (8.9 +/- 15.1 microg/m3). The OC/EC ratios in nighttime ranging from 2.4 to 2.7 are higher than that in daytime ranging from 1.9 to 2.0. The concentrations of OC, EC, PM10 were low with strong winds and high with weak winds. The OC and EC were well correlated with PM10, CO and SO2, which implies they have similar sources. OC and EC were not well correlated with 03. By considering variation of OC/EC ratios in daytime and night time, correlations between OC and O3, and meteorological condition, we speculated that OC and EC in Beijing PM10 were emitted as the primary particulate form. Emission of motor vehicle with low OC/EC ratio and coal combustion sources with high OC/EC ratio are probably the dominant sources for carbonaceous aerosols in Beijing in winter. A simple ratio method was used to estimate the relative contribution of sources to carbonaceous aerosols in Beijing PM10. Motor vehicle source accounts for 80% and 68%, while coal combustion accounts for 20% and 32% in daytime and nighttime, respectively in Beijing. Averagely, the motor vehicle and coal combustion accounted for 74% and 26%, respectively, for carbonaceous aerosols during the observation period. It points to the motor vehicle is dominant emission for carbonaceous aerosols in Beijing PM10 in winter period, which should be paid attention to control high level of PM10 in Beijing effectively.

[Clay ratio as a tracer to assess the origin of soil-derived dust].

The objectives of this research are to characterise the mineralogy of soil-derived dust in Northern China and to set up the mineralogical signature to trace their origin. Mineral composition of aerosol particles is investigated at five sites (Aksu, Dunhuang, Yulin, Tongliao and Changwu) during the intensive field campaign period of ACE-Asia. The results show that the Kaolinite (K) to Chlorite (C) ratio is sensitive to the regional origin of Asian dust. Western source areas (represent by Aksu) displayed the lowest K/ C ratio of 0.3 (in average), while it was found that to increase up to 0.70 (in average) as moving towards north source areas (represent by Yulin). By studying transported dust in a depositional area representative of the Chinese Loess Plateau, the usefulness of the K/C ratio to retrieve the origin of the dust by associating it with back air-mass trajectories is checked. Compared the mineralogical data between Asian dust and Sahara dust, it is shown that K/C ratio is also a good signature to identify the source areas on the global scale.

Interannual variability of carbon cycle implied by a 2-d atmospheric transport model.

A 2-dimensional atmospheric transport model is deployed in a simplified CO2 inverse study. Calculated carbon flux distribution for the interval from 1981 to 1997 confirms the existence of a terrestrial carbon sink in mid-high latitude area of North Hemisphere. Strong interannual variability exists in carbon flux patterns, implying a possible link with ENSO and other natural episodes such as Pinatubo volcano eruption in 1991. Mechanism of this possible link was investigated with statistic method. Correlation analysis indicated that in North Hemisphere, climatic factors such as temperature and precipitation, to some extend, could influence the carbon cycle process of land and ocean, thus cause considerable change in carbon flux distribution. In addition, correlation study also demonstrated the possible, important role of Asian terrestrial ecosystems in carbon cycle.

Chemical composition of aerosols in winter/spring in Beijing.

In 1999 aerosol samples were collected by cascade at Meteorological Tower in Beijing. The 12 group aerosol samples obtained were analyzed using PIXE method, which resulted in 20 elemental concentrations and size distribution of elemental concentrations. From the observation, the elemental concentrations, size distribution of elemental concentrations and their variations are analyzed. It shows that concentrations of the most elements in aerosols increase greatly compared with those in the past except that the concentrations of V, K, Sr, and the source of aerosols has changed greatly in the past decade. Fine mode aerosols increase more rapidly in the past decade, which may be due to the contribution of coal combustion and automobile exhaust. Pb content in aerosol is much higher than that at the beginning of 1980s, and has a decreasing trend in recent years because of using non-leaded gasoline.