含铁血黄素巨噬细胞与损伤时间的相关性研究

目的研究小鼠皮肤损伤愈合过程中含铁血黄素巨噬细胞数量变化与损伤时间的关系,寻找推断损伤时间的病理形态学方法。方法建立小鼠钝器创（挫裂创）和锐器创（切创）动物模型,应用普鲁士蓝染色法观察150只不同损伤时间小鼠伤后损伤区组织中的含铁血黄素巨噬细胞数量变化,同时以5只正常小鼠皮肤组织作对照。结果在皮肤损伤区创缘组织中可见数量不等的含铁血黄素巨噬细胞,并随损伤时间的延长,呈现逐渐上升→高峰→逐渐下降的规律性变化。结论应用普鲁士蓝染色法观察皮肤损伤区创缘组织中的含铁血黄素巨噬细胞数量变化,有望成为一种简便易行、经济实用的推断损伤时间的病理形态学方法。     

Contamination with retinoic acid receptor agonists in two rivers in the Kinki region of Japan

This study was conducted to investigate the agonistic activity against human retinoic acid receptor (RAR) α in the Lake Biwa-Yodo River and the Ina River in the Kinki region of Japan. To accomplish this, a yeast two-hybrid assay was used to elucidate the spatial and temporal variations and potential sources of RARα agonist contamination in the river basins. RARα agonistic activity was commonly detected in the surface water samples collected along two rivers at different periods, with maximum all-trans retinoic acid (atRA) equivalents of 47.6 ng-atRA/L and 23.5 ng-atRA/L being observed in Lake Biwa-Yodo River and Ina River, respectively. The results indicated that RARα agonists are always present and widespread in the rivers. Comparative investigation of RARα and estrogen receptor α agonistic activities at 20 stations along each river revealed that the spatial variation pattern of RARα agonist contamination was entirely different from that of the estrogenic compound contamination. This suggests that the effluent from municipal wastewater treatment plants, a primary source of estrogenic compounds, seemed not to be the cause of RARα agonist contamination in the rivers. Fractionation using high performance liquid chromatography (HPLC) directed by the bioassay found two bioactive fractions from river water samples, suggesting the presence of at least two RARα agonists in the rivers. Although a trial conducted to identify RARα agonists in the major bioactive fraction was not completed as part of this study, comparison of retention times in HPLC analysis and quantification with liquid chromatography-mass spectrometry analysis revealed that the major causative contaminants responsible for the RARα agonistic activity were not RAs (natural RAR ligands) and 4-oxo-RAs, while 4-oxo-RAs were identified as the major RAR agonists in sewage in Beijing, China. These findings suggest that there are unknown RARα agonists with high activity in the rivers.     

Is the association between temperature and mortality modified by age, gender and socio-economic status?

Background

A number of studies have examined the relationship between high ambient temperature and mortality. Recently, concern has arisen about whether this relationship is modified by socio-demographic factors. However, data for this type of study is relatively scarce in subtropical/tropical regions where people are well accustomed to warm temperatures.

Objective

To investigate whether the relationship between daily mean temperature and daily all-cause mortality is modified by age, gender and socio-economic status (SES) in Brisbane, Australia.

Methods

We obtained daily mean temperature and all-cause mortality data for Brisbane, Australia during 1996-2004. A generalised additive model was fitted to assess the percentage increase in all deaths with every one degree increment above the threshold temperature. Different age, gender and SES groups were included in the model as categorical variables and their modification effects were estimated separately.

Results

A total of 53,316 non-external deaths were included during the study period. There was a clear increasing trend in the harmful effect of high temperature on mortality with age. The effect estimate among women was more than 20 times that among men. We did not find an SES effect on the percent increase associated with temperature.

Conclusions

The effects of high temperature on all deaths were modified by age and gender but not by SES in Brisbane, Australia.     

Quantitative assessment of groundwater vulnerability using index system and transport simulation, Huangshuihe catchment, China

Groundwater vulnerability assessment has been an increasingly important environment management tool. The existing vulnerability assessment approaches are mostly index systems which have significant disadvantages. There need to be some quantitative studies on vulnerability indicators based on objective physical process study. In this study, we tried to do vulnerability assessment in Huangshuihe catchment in Shandong province of China using both contaminant transport simulations and index system approach. Transit time of 75% of hypothetical injected contaminant concentration was considered as the vulnerability indicator. First, we collected the field data of the Huangshuihe catchment and the catchment was divided into 34 sub areas that can each be treated as a transport sub model. Next, we constructed a Hydrus1D transport model of Huangshuihe catchment. Different sub areas had different input values. Thirdly, we used Monte-Carlo simulation to improve the collected data and did vulnerability assessment using the statistics of the contaminant transit time as a vulnerability indicator. Finally, to compare with the assessment result by transport simulation, we applied two index systems to Huangshuihe catchment. The first was DRASTIC system, and the other was a system we tentatively constructed examining the relationships between the transit time and the input parameters by simply changing the input values. The result of comparisons between the two index systems and transport simulation approach suggested partial validation to DRASTIC, and the construction of the new tentative index system was an attempt of building up index approaches based on physical process simulation.     

The short-term effect of air pollution on cardiovascular mortality in Tianjin, China: comparison of time series and case-crossover analyses

Background

Many studies have illustrated that ambient air pollution negatively impacts on health. However, little evidence is available for the effects of air pollution on cardiovascular mortality (CVM) in Tianjin, China. Also, no study has examined which strata length for the time-stratified case-crossover analysis gives estimates that most closely match the estimates from time series analysis.

Objectives

The purpose of this study was to estimate the effects of air pollutants on CVM in Tianjin, China, and compare time-stratified case-crossover and time series analyses.

Method

A time-stratified case-crossover and generalized additive model (time series) were applied to examine the impact of air pollution on CVM from 2005 to 2007. Four time-stratified case-crossover analyses were used by varying the stratum length (Calendar month, 28, 21 or 14 days). Jackknifing was used to compare the methods. Residual analysis was used to check whether the models fitted well.

Results

Both case-crossover and time series analyses show that air pollutants (PM₁₀, SO₂ and NO₂) were positively associated with CVM. The estimates from the time-stratified case-crossover varied greatly with changing strata length. The estimates from the time series analyses varied slightly with changing degrees of freedom per year for time. The residuals from the time series analyses had less autocorrelation than those from the case-crossover analyses indicating a better fit.

Conclusion

Air pollution was associated with an increased risk of CVM in Tianjin, China. Time series analyses performed better than the time-stratified case-crossover analyses in terms of residual checking.     

Past and future trends in nutrients export by rivers to the coastal waters of China

We analyzed the past and future trends in river export of dissolved and particulate nitrogen (N), phosphorus (P) and carbon (C) to the coastal waters of China, for sixteen rivers, as calculated by the Global NEWS models (Nutrient Export from WaterSheds). Between 1970 and 2000, the dissolved N and P export increased significantly, while export of other nutrients changed less. We analyzed the future trends (2000-2050) for the Millennium Ecosystem Assessment (MEA) scenarios. In general, the largest increases of dissolved nutrients export are projected for the Global Orchestration scenario, assuming a globalized world and a reactive approach toward environmental management. Future trends in river export of nutrients vary largely among basins, nutrient forms and scenarios. We calculate both increasing and decreasing trends between 2000 and 2050. We also identify the sources contributing to the nutrient export. For selected river basins we present results for alternative scenarios, which are based on the Global Orchestration scenario, but assume more environmental management. This illustrates how the NEWS models can be useful in regional analyses for decision making.     

A joint encoder–decoder error control framework for stereoscopic video coding

Stereoscopic video coding (SSVC) plays an important role in various 3D video applications. In SSVC, robust stereoscopic video transmission over error-prone networks is still a challenge problem to be solved. In this paper, we propose a joint encoder–decoder error control framework for SSVC, where error-resilient source coding, transmission network conditions, and error concealment scheme are jointly considered to achieve better error robustness performance. The proposed joint encoder–decoder error control framework includes two parts: an error concealment algorithm at the decoder side and a rate–distortion optimized error resilience algorithm at the encoder side. For error concealment at the decoder side, an overlapped block motion and disparity compensation based error concealment scheme is proposed to adaptively utilize inter-view correlations and temporal correlations. For error resilience at the encoder side, first, the inter-view refreshment is proposed for SSVC to suppress error propagations. Then, an end-to-end distortion model for SSVC is derived, which jointly considers the transmission network conditions, inter-view refreshment, and error concealment tools at the decoder side. Finally, based on the derived end-to-end distortion model, the rate–distortion optimized error resilience algorithm is presented to adaptively select inter-view, inter- or intra-coding for SSVC. The experimental results show that the proposed joint encoder–decoder error control framework has superior error robustness performance for stereoscopic video transmission over error-prone networks.     

The impact of the 2003 heat wave on mortality in Shanghai, China

In 2003, Shanghai recorded the hottest summer in over 50 years. We investigated the impact on the mortality of a heat wave in 2003 in Shanghai. We calculated excess mortality and rate ratios (RRs) during the heat wave (July 19-August 6, 2003) compared to a reference (non-heatwave) period (June 28-July 9, and August 16-August 22). During the heat wave, the RR of total mortality was 1.13 (95% CI: 1.06-1.20), and the impact was greatest for cardiovascular (RR = 1.19, 95% CI: 1.08-1.32) and respiratory (RR = 1.23, 95% CI: 1.02-1.48) mortality. Gender did not make a statistically significant difference for the heat-wave impact. Elderly people (over 65 years) were most vulnerable to the heat wave. Our analysis showed that the 2003 heat wave had a substantial effect on mortality in Shanghai. Public health programs should be implemented to prevent heat wave-related health problems in the city.     

The relationship between particulate air pollution and emergency hospital visits for hypertension in Beijing, China

Background

A number of epidemiological studies have examined the adverse effect of air pollution on mortality and morbidity. Also, several studies have investigated the associations between air pollution and specific-cause diseases including arrhythmia, myocardial infarction, and heart failure. However, little is known about the relationship between air pollution and the onset of hypertension.

Objective

To explore the risk effect of particulate matter air pollution on the emergency hospital visits (EHVs) for hypertension in Beijing, China.

Methods

We gathered data on daily EHVs for hypertension, fine particulate matter less than 2.5 μm in aerodynamic diameter (PM_2.5), particulate matter less than 10 μm in aerodynamic diameter (PM₁₀), sulfur dioxide, and nitrogen dioxide in Beijing, China during 2007. A time-stratified case-crossover design with distributed lag model was used to evaluate associations between ambient air pollutants and hypertension. Daily mean temperature and relative humidity were controlled in all models.

Results

There were 1,491 EHVs for hypertension during the study period. In single pollutant models, an increase in 10 μg/m³ in PM_2.5 and PM₁₀ was associated with EHVs for hypertension with odds ratios (overall effect of five days) of 1.084 (95% confidence interval (CI): 1.028, 1.139) and 1.060% (95% CI: 1.020, 1.101), respectively.

Conclusion

Elevated levels of ambient particulate matters are associated with an increase in EHVs for hypertension in Beijing, China.     

Health risk assessment on dietary exposure to polycyclic aromatic hydrocarbons (PAHs) in Taiyuan, China

Twenty-five kinds of seven categories of foods were sampled in December 2008 and the concentrations of 16 polycyclic aromatic hydrocarbons (PAHs) were determined. The highest level of total PAHs was detected in pork (195.30 ng/g) whereas the lowest concentration was found in milk (8.73 ng/g). The median values of B[a]P equivalent (B[a]P_eq) daily exposure doses for children, adolescents, adults and seniors of male were estimated to be 392.42, 511.01, 571.56 and 532.56 ng/d, respectively, whereas those for the above population groups of female were found to be 355.16, 440.51, 487.64 and 444.85 ng/d, respectively. The incremental lifetime cancer risk (ILCR) values at the 22.1th, 26.1th, 12.7th, 24.9th, 22.7th, 27.0th, 12.9th, and 25.5th percentiles for male children, male adolescents, male adults, male seniors, female children, female adolescents, female adults and female seniors, respectively, were larger than 10^− 6, indicating high potential carcinogenic risk, and were larger than 10^− 4 at the 74.5th, 78.7th, 60.6th, 77.4th, 75.3th, 79.5th, 60.8th and 77.9th percentiles for the above groups, respectively, which implied significant cancer risk. Sensitivity analysis found that the two variables of oral cancer slope factor of benzo(a) pyrene (SF) and the daily dietary PAH exposure level (ED) had the greater impact than that of body weight (BW) on the ILCR.