Occupational exposure to diesel engine exhaust and serum cytokine levels

The International Agency for Research on Cancer has classified diesel engine exhaust (DEE) as a human lung carcinogen. Given that inflammation is suspected to be an important underlying mechanism of lung carcinogenesis, we evaluated the relationship between DEE exposure and the inflammatory response using data from a cross‐sectional molecular epidemiology study of 41 diesel engine testing workers and 46 unexposed controls. Repeated personal exposure measurements of PM_2.5 and other DEE constituents were taken for the diesel engine testing workers before blood collection. Serum levels of six inflammatory biomarkers including interleukin (IL)‐1, IL‐6, IL‐8, tumor necrosis factor (TNF)‐α, macrophage inflammatory protein (MIP)‐1β, and monocyte chemotactic protein (MCP)‐1 were analyzed in all subjects. Compared to unexposed controls, concentrations of MIP‐1β were significantly reduced by ～37% in DEE exposed workers (P < 0.001) and showed a strong decreasing trend with increasing PM_2.5 concentrations in all subjects (P_trend < 0.001) as well as in exposed subjects only (P_trend = 0.001). Levels of IL‐8 and MIP‐1β were significantly lower in workers in the highest exposure tertile of PM_2.5 (>397 µg/m³) compared to unexposed controls. Further, significant inverse exposure‐response relationships for IL‐8 and MCP‐1 were also found in relation to increasing PM_2.5 levels among the DEE exposed workers. Given that IL‐8, MIP‐1β, and MCP‐1 are chemokines that play important roles in recruitment of immunocompetent cells for immune defense and tumor cell clearance, the observed lower levels of these markers with increasing PM_2.5 exposure may provide insight into the mechanism by which DEE promotes lung cancer. Environ. Mol. Mutagen. 59:144–150, 2018. © 2017 Wiley Periodicals, Inc.     

宋明理学与道家道教之关系

宋明儒在对隋唐佛道兴盛、儒学衰微之因做深刻反思的基础上，吸收了道家道教的心性论、本体论、生成论、修养论并将之融入儒学，使儒学更加精致和完满，促进了儒学复兴并重拾思想主导地位。与此相反，道家道教之地位却日益旁落，为了生存和发展，不得不做出理论调适，从宋明理学之性善论、修身论、伦理观、治世观等吸取养分，对道家道教产生了深远影响。其结果是道教走出山林，走向民间，更具普适性，但也因此渐失本真，渐趋衰微。总而言之，宋明理学与道家道教既为维护各自的道脉和学统而对抗斗争，又为发展自身理论而相互融摄，表现为互融互摄、相资为用的特点，但殊途而同归，共同推动了中国哲学和文化的发展。     

Evaluation of the genetic toxicity of middle distillate fuels

Petroleum middle distillate (PMD) fuels are mixtures of hydrocarbons that distill between ～ 170-370°C. Commercial products that fall into this category include kerosine, diesel fuel, jet fuel, and home heating oil. These products contain both saturated (paraffins and cycloparaffins) and aromatic species, but because of the boiling range normally contain very small amounts of the 3-6 ring polycyclic aromatic hydrocarbon (PAH) constituents, which are considered to be carcinogenic. Nevertheless, there is evidence of weak tumorigenic activity when these materials are repeatedly applied to mouse skin. In the current studies representative products were tested in two commonly used, short-term assays for genetic toxicity, the Salmonella/mammalian microsome mutagenicity assay and the mouse bone marrow micronucleus test. All samples were inactive in the micronucleus assay, and three were clearly inactive in the Salmonella test. Of the remaining two, one was marginally active in the Salmonella assay, and one was equivocal. The marginally active sample contained detectable levels of PAH due to the use of catalytically cracked materials as blending stocks. The results indicated that PMDs that do not contain cracked material were not mutagenic. Thus they may produce tumors via nongenotoxic processes. Those products that do contain cracked stocks may have sufficient PAH to be mutagenic in the Salmonella assay, and in those cases the PAH might also contribute to tumor formation. © 1994 Wiley-Liss, Inc.     

催化裂化柴油萃取-光化学反应深度脱硫

采用液液萃取-光化学脱硫组合工艺，研究不同体系的光致脱硫效果，探讨了二苯甲酮敏化催化裂化柴油中脱硫反应的动力学并与二甲亚砜（DMSO）直接萃取脱硫进行了比较。硫化物的光氧化产物用溶剂萃取法脱除，考察的溶剂为水／乙腈混合物及二甲亚砜。实验数据表明：在萃取剂与柴油的体积比为4：3、溶剂含水量φ=0．25的条件下，柴油脱硫率可达64％，收率949／6。对柴油原料及光氧化柴油抽出物进行了红外光谱分析，结果表明柴油中硫化物降解后的形态包括亚磺酸、亚砜和硫酸酯。     

Initial Experience with a New Single Chamber, Dual Sensor Rate Responsive Pacemaker

In August 1991, a new single chamber pacemaker became available that utilizes information from two sensors, activity and stimulus-to-T wave (QT) interval. We are reporting on the first 90 implants in 21 centers. T wave sensing was adequate at implantation in 88/90 patients, with a safety margin of > 100% in 86/90, Activity sensing was adequate in all patients. The contribution of each sensor fsensor blending) is programmable for each patient. Of 75 patients assessed at 1 month after implant, three have been programmed to "Activity-Only" mode, and 72 to dual sensor mode. Of these, 18 have been programmed to "QT < Activity," 48 to "QT = Activity," and 6 to "QT > Activity." Forty-five patients underwent exercise testing in dual sensor mode and a subgroup of 15 also underwent exercise testing in Activity-Only mode. The dual sensor mode produced a more gradual increase in pacing rate. Sensor Cross Checking^tmsatisfactorily prevented a sustained high pacing rate in tests of false-positive activity sensing (tapping, vibrating pacemaker, or static pressure). The maximum pacing rate on walking downstairs (94.2 ± 7.2 ppm) was similar to that produced by walking upstairs (91.6 ± 5.9 ppm). We conclude that initial assessment of this dual sensor, single chamber, rate responsive pacemaker confirms that the algorithm for combining data from two sensors functions satisfactorily. Dual sensor rate responsive pacing may offer significant advantages over single sensor devices, and further studies of this novel device are indicated.     

Lung cancer and elemental carbon exposure in trucking industry workers

Background: Diesel exhaust has been considered to be a probable lung carcinogen based on studies of occupationally exposed workers. Efforts to define lung cancer risk in these studies have been limited in part by lack of quantitative exposure estimates.Objective: We conducted a retrospective cohort study to assess lung cancer mortality risk among U.S. trucking industry workers. Elemental carbon (EC) was used as a surrogate of exposure to engine exhaust from diesel vehicles, traffic, and loading dock operations.Methods: Work records were available for 31,135 male workers employed in the unionized U.S. trucking industry in 1985. A statistical model based on a national exposure assessment was used to estimate historical work-related exposures to EC. Lung cancer mortality was ascertained through the year 2000, and associations with cumulative and average EC were estimated using proportional hazards models.Results: Duration of employment was inversely associated with lung cancer risk consistent with a healthy worker survivor effect and a cohort composed of prevalent hires. After adjusting for employment duration, we noted a suggestion of a linear exposure-response relationship. For each 1,000-μg/m3 months of cumulative EC, based on a 5-year exposure lag, the hazard ratio (HR) was 1.07 [95% confidence interval (CI): 0.99, 1.15] with a similar association for a 10-year exposure lag [HR = 1.09 (95% CI: 0.99, 1.20)]. Average exposure was not associated with relative risk.Conclusions: Lung cancer mortality in trucking industry workers increased in association with cumulative exposure to EC after adjusting for negative confounding by employment duration.     

柴油加氢装置中氢气管道的材质选择

综合分析了某柴油加氢装置中氢气管道在反应部分（包括压缩机）、循环氢脱硫、低分气脱硫和膜分离部分,根据其不同的设计条件,综合考虑其设计温度,设计压力及其介质特性等因素确定工艺管道的材质。     

Advanced Biofuels from ABE (Acetone/Butanol/Ethanol) and Vegetable Oils (Castor or Sunflower Oil) for Using in Triple Blends with Diesel: Evaluation on a Diesel Engine

From a technical and economic point of view, our aim is to provide viable solutions for the replacement of fossil fuels which are currently used in internal combustion diesel engines. In this research, two new biofuels composed of second-generation vegetable oils (SVO),used oil sunflower (SO) or castor oil (CO), and the ABE blend (acetone/butanol/ethanol) were evaluated. ABE is an intermediate product from the fermentation of carbohydrates to obtain bio-butanol. Besides, the ABE blend exhibits suitable properties as biofuel, such asvery low kinematic viscosity, reasonable energy density, low autoignition temperature, and broad flammability limits. Diesel/ABE/SVO triple blends were prepared, characterized and then, tested on a diesel engine, evaluating power output, consumption, and exhaust emissions. The power output was slightly reduced due to the low heating values of ABE blend. Also, engine consumed more fuel with the triple blends than with diesel under low engine loads whereas, at medium and high loads, the fuel consumption was very similar to that of diesel. Regarding exhaust gas emissions, soot wasnotably reduced, and nitrogen oxides (NO_x) and carbon monoxide (CO₂) emissions were lower or comparable to that of diesel, while the CO emissions increased. The use of these biofuels allows the replacement of high percentagesof diesel without compromising engine power and achievinga significant reduction in pollution emissions. Furthermore, a notable improvement in cold flow properties of the fuel blends is obtained, in comparison with diesel.     

Comparison of DNA adduct induction in vitro by PAHs and nitro-pahs in freshly isolated rat hepatocytes

Polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs have been identified widely in occupational and environmental pollution, such as diesel engine emissions and other combustion products. In most cases, hepatic biotransformation is involved in converting these chemicals to their carcinogenic metabolites. It has been demonstrated that isolated hepatocytes possess substantial amounts of the enzymes responsible for metabolizing xenobiotics and are therefore a convenient model for studying chemicals that require activation to exert their carcinogenic effects. In this study, rat hepatocytes were isolated by collagenase digestion and then exposed to benzo[a]pyrene (B) [a]P), benzo[a]anthracene (B[a]A), 1-nitropyrene (1-NP) and 1,6-dinitropyrene (1,6-DNP) at different doses and/or times so that DNA adducts levels, as measured with the ³²P-postlabelling technique, could be compared. Each of the four compounds tested induced significant increases of total DNA adducts with clear dose-related responses. One or more individual adducts were identified as major adducts for each compound. Time-related increases of DNA adducts were also observed from 1 to 4 hr of incubation. Greater amounts of DNA adducts were induced by B[a]P or 1,6-DNP than by B[a]A or 1-NP, with potency being in the order 1,6-DNP > B[a]P > 1-NP B[a]A. These results demonstrate that freshly isolated hepatocytes can be used as an effective in vitro system for the detection of DNA adducts using ³²P-postlabelling, and have shown 1,6-DNP to be the most potent of the tested constituents of diesel emissions.     

SBS-g-GMA对PPO/PBT合金性能影响的研究

采用熔融共混法制备了SBS—g-GMA/PPO/PBT、SBS/PPO/PBT的合金,通过HAAKE、MI、DSC、SEM等方法对合金进行了表征。研究了SBS—g—GMA对PPO/PBT合全相容性的影响,探讨了合全的流变性能、热性能、形态结构和力学性能。