深圳市2002-2004年集体性食物中毒分析

目的为给深圳市的食物中毒预防工作提供借鉴,对深圳市2002-2004年的食物中毒情况进行了分析。方法对深圳市及各区卫生监督部门上报的集体性食物中毒报告资料进行统计学、流行病学分析。结果3年中深圳市共发生食物中毒94起,平均每年31.3起,1666人中毒,平均每年555人。2003年有1人死亡。中毒主要发生季节为每年第二、第三季度。宝安和南山为高发区域,共占53.2%,集体食堂引起的食物中毒起数和发病人数最多,分别为71起1429人。引起中毒的食品主要为动物性食品。食物中毒的致病因素60.6%为细菌性食物中毒,细菌性食物中毒中40.3%是由副溶血性弧菌引起,占细菌性食物中毒的第一位。结论深圳市食物中毒的好发季节都在夏、秋季节,大多集中在集体食堂,以细菌性食物中毒为主,预防食物中毒今后的工作重点首先应是加强集体食堂卫生管理问题。

The Effect of Toxic Sulfide Exposure on Oxygen Consumption and Oxidation Products in Urechis unicinctus(Echiura:Urechidae)

To investigate sulfide detoxification in Urech＆ unicinctus, oxygen consumption rate and sulfide detoxification products were analyzed during sulfide exposure under controlled laboratory conditions. The results showed that oxygen consumption rates were elevated significantly during 3 h sulfide exposure compared to the control （P〈0.05）. The concentration of sulfite in body wall and hindgut of experimental worms increased significantly （P〈0.05） when exposed to 50 μmolL^-1 sulfide, reached a maximum at 24 h and then decreased. Similar result was observed in worms exposed to 150 μmolL^-1 sulfide except that sulfite concentration reached a maximum at 12 h. Contents of thiosulfate in body wall and hindgut of U. unicinctus exposed to sulfide were also significantly higher than that of the control without sulfide exposure. In conclusion, during short-time sulfide exposure U. unicinctus may raise oxygen consumption to detoxify toxic sulfide into sulfite and thiosulfate. Sulfide detoxification was restrained when the exposure time was prolonged or sulfide concentration was increased, which was indicated by decrease of sulfite, the intermediate product of sulfide detoxification.

Review of Factors Affecting the Yield and Quality of Corn Silage

Corn silage is the most popular and important source of energy and fber for ruminants. Much research focused on the chopping length, additives, sealing system, harmful bacteria and their toxins, and so forth, has been done on corn silage both at home in China and abroad. Some suggestions were presented in this review： （1） Corn silage modulation： Whole-plant corn harvested at the milk-ripe stage with a dry matter （DM） content of 30%~40% was selected as silage material and treated by rubbing and cutting. In the process of silage, commercial Lactobacillus buchneri was inoculated, exogenous protease added appropriately, cellulose enzyme added depending on the phenological period, the silage container and the species of the animals, and coextruded polyethylene？polyamide oxygen barrier flm （OB） selected as the seal material. （2） Strengthening management： Aerobic exposure should be avoided at the storage stage and reduced during the feeding phase. The proportion of corn silage was increased depending on the type of animal and their management. （3） Suggestions for further research： Further studies would be needed for the effects of liquid and solid wastes on soil, water and vegetation, and the treatment of these wastes.

动、植物性食物中毒诊断标准探讨

根据现行动、植物性食物中毒诊断标准,确诊条件之一须取得形态学鉴定资料,但因难以取得该资料,对依法确诊带来困难。形态学鉴定条件执行难点和问题有:缺少鉴定机构、方法和标准;无剩余中毒食物或加工后形态破坏;普通市售有毒动、植物食物及常见误食的有毒动、植物的鉴定价值小;动、植物加工品形态学鉴定困难;同一有毒成分存在不同种类生物问题。为此,提出完善诊断标准的建议:形态学鉴定应作为补充性诊断标准;实验室诊断资料范围应扩大;对诊断标准总则表述提出建议。并探讨建议国家应出台有毒动、植物食品目录,加强毒素及人体生物样品等实验室指标及检测方法研究。

Biodegradation of Acid Anthraquinone Dye in a Facultative-aerobic Process:Kinetics and Products

The transformation of an anthraquinone dye blue 324 in a facultative-aerobic(F-A) system was investigated.Kinetic parameter study showed that higher Vmax coupled with more recalcitrant chemical oxygen demand(COD) were found in the facultative biofilm reactor(FBR) than in the aerobic reactor(AR).Results of the product analyses indicated that most of dye molecular could be facultatively broken down into simple intermediates,which would be further degraded under subsequent aerobic condition.The main metabolites in each reactor were detected by infrared(FT-IR) and high performance liquid chromatography and mass spectrometry(HPLC-MS).Comparison of the toxicities among the dye and its metabolites was conducted,surprisingly,the colorless intermediates from FBR possessed less inhibitory than original dye and the median effective luminescence concentration(EC50) in 15 min for aerobic effluent could not be detected,showing that hardly toxic products existed in the aerobic process effluent.

Removal of toxic metal ions using chitosan coated carbon nanotube composites for supercapacitors

Environmental pollution and energy crisis are two major global challenges to human beings.Recovering energy from wastewater is considered to be one of the effective approaches to address these two issues synchronously.As the main pollutants in wastewater,toxic heavy metal ions are the potential candidates for energy storage devices with pseudocapacitive behaviors.In this study,toxic metal ions of Cr(VI)and Cu(II)are removed efficiently by chitosan coated oxygen-containing functional carbon nanotubes,and the corresponding equilibrium adsorption capacity is 142.1 and 123.7 mg g^(-1).Followed by carbonization of metal ions-adsorbed adsorbents,Cu-and Cr N-loaded carbon composites can be obtained.Electrochemical measurements show that the supercapacitor electrodes based on Cu-and Cr N-loaded carbon composites have specific capacitance of 144.9 and 114.9 F g^(-1)at2 m V s^(-1),with superior electrochemical properties to pure chitosan coated carbon nanotubes after carbonization.This work demonstrates a new strategy for the resource-utilization of other heavy metal ions for energy devices,and also provides a new way to turn environmental pollutants into clean energy.

Numerical Investigation of High Pressure and High Reynolds Diffusion Flame Using Large Eddy Simulation

Today,with nonstop improvement in computational power,Large-Eddy Simulation(LES) is a high demanding research tool for predicting engineering flows.Such flows on high pressure condition like diesel engines is extensively employed in ground and marine transportation,oblige the designer to control and predict toxic pollutants,while maintaining or improving their high thermal efficiency.This becomes one of the main challenging issues in decades.In the present work,numerical investigation of diffusion flame dynamics is performed in the near-field of high-Reynolds jet flow on high pressure condition encountered in diesel engine applications.This work discusses the implementation of Partially Stirred Reactor(PaSR) combustion model by the approaches of large eddy simulation(LES).The simulation results show that LES,in comparison with Reynolds-Averaged Navier-Stokes(RANS) simulation predicts and captures transient phenomena very well.These phenomena such as unsteadiness and curvature are inherent in the near-field of high Reynolds diffusion flame.The outcomes of this research are compared and validated by other researchers' results.Detailed comparisons of the statistics show good agreement with the corresponding experiments.