Influencing Factors and Biological Control of Aflatoxin Contamination in Peanuts

Peanut is an important economic crop and oil crop in China.It is vulnerable to infection by Aspergillus flavus during production,storage,transportation and processing,causing aflatoxin(AFT)contamination.This paper introduced the status and characteristics of AFT contamination in China,analyzed the infection pathways and influencing factors of A.flavus,and discussed the prevention and control technology of AFT contamination in peanuts from the view of the use of beneficial microorganisms.

Controlled-release fertilizer(CRF): A green fertilizer for controlling non-point contamination in agriculture

Fertilizers contribute greatly to high yields but also result in environmental non-point contamination, including the emission of greenhouse gas(N 2O) and eutrophication of water bodies. How to solve this problem has become a serious challenge, especially for China as its high ecological pressure. Controlled-release fertilizer(CRF) has been developed to minimize the contamination while keeping high yield and has become a green fertilizer for agriculture. Several CRFs made with special coating technology were used for testing the fertilizer effects in yield and environment through pot experiment and field trial. The result indicated that the CRFs had higher N use efficiency, thus reducing N loss through leaching and volatilization while keeping higher yields. Comparing with imported standard CRFs, the test on CRFs showed similar fertilizer effect but with much lower cost. CRFs application is becoming a new approach for minimizing non-point contamination in agriculture.

Correlation of Aflatoxin Contamination in Peanuts with Rhizosphere Microorganisms and Its Comprehensive Control

Aflatoxin contamination is an important hazard factor affecting the quality safety and food safety of peanut production, which seriously threatens people's health and safety. In this paper, the background and harmful causes of aflatoxin contamination were analyzed in detail, with attention focusing on its control measures, which has certain guiding significance for the comprehensive control of aflatoxin contamination.

Preliminary Study on Biological Control of Mycotoxin Contamination in Agricultural Products and Its Mechanism

Aflatoxin is the most powerful carcinogen and highly toxic mycotoxin known in nature. It can cause serious toxin pollution to agricultural products, foods and fodders, and is extremely harmful to human and animal health. For aflatoxin pollution, the emphasis is on the control of source, and biological control is favored by scientists because of its advantages of environmental protection and ecological safety. According to the morphology, color and appearance of microbial colonies isolated from maize kernels, 300 bacterial strains were obtained from main maize-producing areas including Tangshan City, Handan City, Shijiazhuang City and Cangzhou City. Two biocontrol bacterial strains(B120 and B65) having a strong control effect on aflatoxins were screened. After identification by molecular biology and physical and chemical properties, the two biocontrol bacterial strains were identified as Bacillus amyloliquefaciens. Their effects on spore germination, mycelial growth and toxin degradation of Aspergillus flavus were investigated. The results showed that strains B120 and B65 could significantly inhibit the spore germination and mycelial growth of A. flavus and reduce aflatoxin production. This study provides a new way to prevent and control the pollution control of aflatoxins in agricultural products.

Analysis of Microbial Contamination Factors and Critical Control Points in the Process of Hog Slaughter and Production

In order to provide a reference for the further study of microbial contamination in the pork production process. Microbial contamination of pigs came from three slaughterhouses were detected, and critical control points in the progress of hog slaughter and processing were analyzed. The results showed that microbial con- taminatian existed in the entire slaughter and processing progress, including shower and assassination bloodletting, separation of the internal organs, chopping boards, workshop environment, personal hygiene of the operators, etc. , which should be paid more attention to. The results indicated that reasonable protection measures should be carried out, disinfection awareness of the operators should be improved, and regular disinfection should be ruled under the condition of continu- ous operation.

Treatment of Phenol-Contaminated Soil by Potassium Ferrate Based on pH Control

This study aims to optimize the treatment of phenol-contaminated soil by potassium ferrate. Variations in pH value can accurately reflect the state and reaction status of the entire treatment process. Therefore, the pH value could be an important variable for optimizing the reaction conditions and achieving the automatic control of the process. About 99.89% of phenol was removed after 10 min of the pH-contxolled reaction at a rotational speed of 40-70 r/min, with the initial phenol concentration equating to 10.0 g/kg and the total water consumption reaching 2.72 L （at a soil/water ratio of 1：0.68）. The test results could provide a basis for practical application of automatic reaction control by pH value.

Bacterial contamination of orally-consumed crude herbal remedies:A potential source for multi-drug resistant pathogens in man

Objective:The acceptability of herbal remedies for alleviating discomforts and ill-health has become very popular, on the account of the increasing cost of allopathic medicine for personal health maintenance.The observable non-adherence of herbalists to the established World Health Organization(WHO) / National Agency for Food and Drug Administration Control(NAFDAC) regulations for the quality control of herbal medicines is an issue for concern.In view of this,34 popular and widely consumed crude herbal remedies in southwestern,Nigeria were screened for compliance with standard limits for bacterial contamination,bacteria flora and their antibiotic susceptibility pattern.Methods:Isolates recovered from samples were identified using the cultural, morphological and biochemical characteristics.They were also tested for drug sensitivity using standard procedures. Results:A heavy bacteria load ranging from 3.00×10~3-9.58×10~5 CFU/ML and 1.20×10~5- 5.41×10~5 CFU/ML was observed for water and spirit extracted preparations respectively.The bacteria flora cum contaminants were:Staphylococcus aureus,Bacillus cereus,Bacillus subtilis,Pseudomonas aeruginosa, Micrococcus luteus,Lactobacillus plantarum,Klebsiella pneumoniae,Escherichia coli,streptococcus,Shigella, Neisseria,Arthrobacter,Kurthia and Clostridium species.All the isolates were multi-drug resistant(MDR) strains.Conclusion:The crude herbal preparations consumed in Nigeria failed to comply with the internationally recognized standards regarding bacteria load and flora.The presence of MDR pathogens is of greatest concern. It poses a great risk to consumers health and could be a source of introducing MDR organisms into the human population.There is the need for the enforcement of established guidelines to ensure the safety of these preparations.

Numerical Study on Effects of Door-Opening on Airflow Patterns and Dynamic Cross-Contamination in an ISO Class 5 Operating Room

The contamination diffusion to the operating room when the door is open was simulated with a computational fluid dynamic(CFD) method,to give the extent of the contamination diffusion.The influence of the door-opening procedure was ignored since the door of the operating room is normally a sliding one.The flow field in the case of the 16 s course of opening the door was simulated.The simulated and the experimental results demonstrate that the extent of the contamination diffusion is around 1.5 m when there is no temperature difference between indoor and outdoor,and there is hardly any contamination diffusion when the temperature difference is 1 ℃.It can be concluded that the positive pressure difference in the operating room lost its function in preventing the contamination when the door is open.That the temperature of corridor is lower than that of operating room contributes to contamination control.Keeping 1 ℃ temperature difference between corridor and operating room and increasing positive pressure and air flow are suggested.It is more secure to set up an anteroom if persons come in or out of the operation room at the course of surgery.

Radiological and X-Ray Diffraction Characterization of Bauxite and Rutile Ore Contaminated Environment in Kanam and Wase Mineral Exploration Sites, Plateau State-Nigeria

Two non-destructive analytical techniques (gamma spectrometer and X-ray diffractometer) were employed in the analysis of bauxite and rutile ore and their vicinity soil and control sourced within the Kanam and Wase mineral exploration sites. The activity concentrations of natural radionuclides 238U, 232Th, and 40K in the soil samples received from bauxite and rutile mineral mining vicinities revealed high concentrations of 238U, 232Th, and 40K compared to the control soil samples sourced 500 m away from the mineral exploration vicinities. Radiological detriments RLI, AUI, Hin and Hex unveiled values exceeding the radiation standard concentration (>1) for soil. X-ray diffraction characterization of bauxite ore revealed the interlocking minerals of Bauxite (18)%, Albite (11)%, Garnet (15)%, Illite (6)% and Muscovite (43)% in various proportions obtained within the 2θ range (9.18 to 64.4) and a peak value (intensity, cps) of 3400. Pure bauxite percentage in the ore meets metallurgical grade (15 - 25)%. X-ray diffraction of rutile ore revealed the minerals of rutile (40)%, quartz (21.4)%, ilmenite (27)% and garnet (11.8)% found within the 2θ range (27.5 to 35.6) and a peak value intensity of 31.1 - 100.0 cps also meeting the metallurgical grade of 15% - 25%. The major environmental concern associated with the mineral-sands industry is the radiation hazards, pollution of ground-water sources from heavy metals, mineral transport with heavy equipment’s, dredging operations in fragile coastal area and clearing of vegetation.

Renewed Focus on the Threat of Cross-Contamination in Molecular Laboratories: Notes from the COVID-19 Testing Experience in Bangladesh

Rapid and accurate laboratory diagnosis of SARS-CoV-2 infection is crucial for the management of COVID-19 patients and control of the spread of the virus. At the start of the COVID-19 pandemic, Bangladesh had only one government molecular laboratory where real-time RT-PCR would be performed to diagnose SARS-CoV-2 infection. With the increasing number of suspected cases requiring confirmation diagnostic testing, there is a requirement to expand capacity for large-scale testing quickly. The government of Bangladesh established over 100 molecular laboratories within one year to test COVID-19. To expand the testing capacity, the government was compelled to recruit laboratory staff with limited experience and technical expertise, especially in molecular assays, to process specimens, interpret results, troubleshoot. As a result, the risk of diagnostic errors, such as cross-contamination, increased, potentially undermining the efficacy of public health policies, public health response, surveillance programs, and restrictive measures aimed toward containing the outbreak. In this piece, we discuss the different sources of cross-contamination in the COVID-19 RT-PCR laboratories and proffer practical preventive measures to avoid them.

上海市典型行业退役场地土壤和地下水石油烃污染碳链组分特征及风险评估

我国目前对石油烃污染场地的健康风险评估方法在风评规范中并未明确,为探究不同行业退役场地石油烃污染特征及其对健康风险评估结果的影响,本研究在上海市目前主要工业行业类型中选取其中5类数量较多的典型行业(橡胶和塑料制品业、机械制造业、香料制造业、涂料制造业、金属结构制造业)退役场地,开展重点污染区域土壤和地下水石油烃(C_(5)~C_(40))含量水平和碳链组分分析。结果表明:在所选5类典型行业退役场地中,石油烃在土壤和地下水中有明显积累,土壤石油烃C_(5)~C_(40)检出范围为165~10105.6 mg/kg,地下水石油烃C_(5)~C_(40)检出范围为0.098~17634 mg/L。从石油烃碳链分配比例来看,以使用润滑油为主的机械制造业和金属结构制造业土壤与地下水石油烃分布趋势一致,均以高碳链的芳香烃和脂肪烃为主;以油品作为原料的涂料制造业、香料制造业、橡胶和塑料制品业土壤石油烃均以高碳链脂肪烃为主,地下水石油烃则以低碳链芳香烃为主。蒙特卡罗模拟结果显示,各类型污染场地土壤石油烃中脂肪烃和芳香烃的C10~C12含量占比对场地的风险水平影响最大,地下水石油烃中脂肪烃C13~C16的含量占比对场地风险水平影响较大,土壤和地下水石油烃均为低碳链(C16以下)含量占比对场地风险水平的敏感性较强。研究显示,不同类型石油烃污染场地土壤和地下水石油烃碳链分配情况并不一致,应分别对土壤和地下水开展石油烃碳链含量精细化检测,这对摸清污染场地的石油烃的污染类型以及制定合理的石油烃的风险控制值是非常必要的。

空间站舱内微量有害气体状态评价和流转分析

文章聚焦于中国空间站长期在轨运行中微量有害气体的整体状态和控制情况,阐述了微量有害气体随舱内物质循环向冷凝水回收净化以及CO_(2)去除和还原等环节流转的规律。通过在轨状态分析、地面比对评估试验结果和流转特性分析,说明中国空间站各净化系统对舱内微量污染物成分进行了有效控制,舱内空气中微量有害气体浓度保持在较低水平。研究旨在为后续微量有害气体净化环节的运行和监测提供指导。

基于位置分配的去蜂窝massive MIMO系统导频分配功率控制算法

针对去蜂窝(cell free,CF)大规模多输入多输出(multiple-input multiple-output,MIMO)系统中存在严重的导频污染问题,提出了一种基于位置分配的贪婪导频分配功率控制算法(greedy pilot assignment based on location with pilot power control,GPABL with PPC).首先,遵循相邻用户不分配相同导频序列的原则进行贪婪导频分配(greedy pilot assignment,GPA);然后,在导频分配的基础上叠加了导频功率控制,选择合理的导频功率控制系数减小信道估计的均方误差.仿真结果表明,将两种方式结合起来进行导频优化,系统的吞吐能力有所提升.

3种中药配方颗粒全生产链的污染微生物考察

目的:对郁金、桑叶、蝉蜕中药配方颗粒生产全过程污染微生物进行考察,建立数据库,探索中药配方颗粒生产过程微生物关键控制点及控制措施,为企业提供示范性研究,为制定标准、改进生产工艺提供依据,填补质量全过程控制的空白。方法:对3种中药配方颗粒的原材料、中间产品、成品按照《中国药典》2020年版进行分析检测,采用质谱技术对负载微生物进行鉴定,分析研究从药材原料到中药配方颗粒成品的外源性污染微生物的程度及容易污染微生物的种类。结果:3种中药配方颗粒的原材料(中药饮片)微生物污染较严重,原材料的耐热芽孢杆菌即使经过工艺处理后,仍能在中间产品、成品中检出,并造成部分批次需氧菌总数结果超出限度规定;中间产品、成品中还检出来源于人和动物肠道中的屎肠球菌。结论:①加强中药饮片的微生物污染控制,有利于降低终端产品的微生物负载;②3种中药配方颗粒的生产工艺存在芽孢类微生物污染的风险,需优化生产工艺参数来降低微生物负载;③药品生产企业需加强对产品全过程控制,降低微生物污染风险。

啤酒中呕吐毒素的污染、变化及生产过程中的控制进展

啤酒产业是我国饮料酒行业中发展最为迅速的产业之一,啤酒的原料生产和加工酿造环节与产品品质和产业发展密切相关。其中,啤酒原料污染或加工过程不当而产生的呕吐毒素(Deoxynivalenol,DON)控制是最关键、最受关注的研究热点之一。本文针对影响啤酒品质和安全的重要真菌毒素DON的污染情况进行分析,结合啤酒酿造关键工艺分析DON迁移及转化情况,从物理、化学和生物这三大方法分别探讨了啤酒酿造过程中DON污染的控制措施,并提出DON控制潜在发展方向,旨在为啤酒中DON污染控制、啤酒品质进一步提升提供理论支撑。

离子注入过程中的颗粒污染来源及管控措施

离子注入作为半导体制造中的关键工艺之一,其工艺过程中产生的颗粒污染已经成为影响器件性能和成品率的重要因素。通过分析离子注入工艺过程中颗粒污染的种类和来源,阐述了工艺过程中预防和管控颗粒污染的措施,并通过对比试验,分析了注入过程中扫描次数、定向台定向、机械手传片、片库抽泄真空和靶台压盖升降对圆片表面颗粒的影响程度,为离子注入过程中的颗粒污染控制提供依据和建议。

MBR处理农村生活污水及膜污染控制研究进展

农村生活污水水质水量变化大,排放量小但分布分散,污染物浓度较高。而膜生物反应器(MBR)抗冲击负荷能力强、占地面积小、污染物去除效率高。因此,MBR技术在农村生活污水处理市场的前景较为广阔。这里主要从农村生活污水的特点及处理技术、国内外利用MBR处理农村生活污水的现状、膜污染的作用机制和类型以及控制措施三个方面进行了综述。通过国内外应用现状对比,发现分质处理能更好地实现资源回收,并减轻MBR在脱氮除磷方面的压力;针对膜污染问题,建议从改性膜材料、改良污泥混合液特性、改善操作条件和膜清洗入手,以此来减缓膜污染,降低运行成本,从而更好地推进该技术在农村地区的应用。

食源性致病菌交叉污染风险的数学模拟及精准防控策略研究进展

食源性致病菌交叉污染是食品加工生产、贮藏运输、家庭消费等环节中广泛存在的一种现象,被视为导致食源性疾病暴发的重要原因之一。运用数学模型模拟食源性致病菌在不同食品媒介中的转移情况,能够帮助人们理解食源性致病菌交叉污染的传播规律。进一步将交叉污染模型与微生物风险评估相结合,明确交叉污染发生的关键环节,并配合一系列新型的抗菌涂层设计,将能有效地预防和控制交叉污染的发生。因此,本文首先综述了食品工业及家庭生活中致病菌交叉污染导致的食品安全问题,并详细地概述食源性致病菌交叉污染数学建模的最新研究进展,最后通过全局控制和源头控制两个层面,分别阐述了微生物风险评估与危害分析与关键控制点相结合和抗菌涂层在食源性致病菌交叉污染防控中的应用,并对交叉污染未来的研究方案和控制策略提出了展望。

细菌在反渗透膜生物污染中的作用及防控研究进展

海水反渗透膜的生物污染是海水淡化行业面临的一个世界性难题。查阅近年国内外关于海水淡化系统反渗透膜生物污染的文献以及其他相关资料,对海水淡化系统RO膜上优势细菌群落组成及胞外聚合物在膜生物污染中的作用进行了总结,讨论了与膜污染有关的耐氯菌种并简述了以预处理为主的常见防控方法和使用群体抑制酶为主的生物防治新方法。为解决耐氯菌生物膜难以被杀菌剂去除、处理成本较高等问题,提出未来应针对耐氯菌及其他胞外聚合物分泌能力强的微生物等开展研究,并结合预处理、化学清洗和生物控制等方法设计因地制宜的全面防控方案。

汞污染地块分级风险管控技术体系研究

有色金属冶炼、电石法聚氯乙烯、汞触媒等特定行业已经形成数量不等的汞污染地块。精准识别地块中汞污染分布及迁移归趋,构建基于环境风险的防控技术体系,是此类地块有效修复与风险管控的关键。本文通过分析汞污染地块的特点及成因,总结了发达国家在政策法规、标准制定和制度建设等方面的历史实践经验,并结合我国在汞污染防控方面已有的相关法律、法规与管理政策,提出了基于环境风险量化表征与逐级分类管控的综合技术体系。首先,以健康与生态保护为核心要素,对环境风险精准量化表征,重点考虑地块中汞的赋存形态与生物有效性、特殊暴露途径与敏感受体、迁移与归趋等特征化因子;其次,基于污染调查与风评结果进行风险筛查,对地块风险等级进行科学划分;最后,从标准限值、修复技术和管理制度3个角度,选择与风险等级相匹配的差异化管控技术。该技术体系以风险管控为导向、以量化评估为基础、系统修复与全过程管理为途径,形成全方位、立体化、精准性的汞污染地块风险管理模式,符合《土壤污染防治行动计划》(“土十条”)的基本原则,为我国地块尺度汞污染控制提供体系保障,支撑我国《关于汞的水俣公约》履约活动。