Computational interaction analysis of organophosphorus pesticides with different metabolic proteins in humans

Pesticides have the potential to leave harmful effects on humans, animals, other living organisms, and the environment. Several human metabolic proteins inhibited after exposure to organophosphorus pesticides absorbed through the skin, inhalation, eyes and oral mucosa, are most important targets for this interaction study. The crystal structure of five different proteins, PDBIDs： 3LII, 3NXU, 4GTU, 2XJ1 and 1YXA in Homo sapiens （H. sapiens）, interact with organophosphorus pesticides at the molecular level. The 3-D structures were found to be of good quality and validated through PROCHECK, ERRAT and ProSA servers. The results show that the binding energy is maximum -45.21 relative units of cytochrome P450 protein with phosmet pesticide. In terms of H-bonding, methyl parathion and parathion with acetylcholinesterase protein, parathion, methylparathion and phosmet with protein kinase C show the highest interaction. We conclude that these organophosphorus pesticides are more toxic and inhibit enzymatic activity by interrupting the metabolic pathways in H. sapiens.

Application and Promotion of Non-pesticide Replacing High-toxic Pesticide Techniques and Its Benefit Analysis in Kunming City

[ Objective] The paper was to operate the application and promotion of non-pesticide replacing high-toxic pesticides techniques in Kunming City, and to analyze its benefit. [ Method ] Through application and promotion of frequency trembler grid lamps, sticking plate trapping technology, construction of treatment ponds for field waste vegetable leaves, standardized （accurate） cultivation techniques, cultivation techniques of disease-resistant varieties and diverse cultivation technologies, the promotion benefit of non-pesticide replacing high-toxic pesticides techniques was comprehensively investigated and evaluated. [ Result ] The appli- cation and promotion area of non-pesticide replacing high-toxic pesticides techniques in Kunming City during 2006 -2010 reached 94 667 hm2. The investigation on control efforts and quantitative analysis of cost/benefit showed that the beneficial result of application and promotion of non-pesticide replacing high-toxic pesticides techniques was higher than the direct benefit of application and promotion of traditional pesticide replacing techniques. This improvement innovated the traditional pesticide replacing method in replacement work of high-toxic pesticides, reducing the usage volume of pesticide in Kunming City. [ Conclusion] The application and promotion of non-pesticide replacing high-toxic pesticides techniques improved the economic, social and ecological benefit of replacement work of high-toxic pesticides, protected the agricultural ecological environment and promoted the sustainable development of agricultural production.

Statistical Analysis on Field Efficacy Trial of Pesticide Using Visual Basic

[Objective] To introduce a convenient and easy way for the statistical anal- ysis on field efficacy trials of pesticide by using Visual Basic. [Method] The calcula- tion procedure of using Visual Basic to conduct statistical analysis on the field efficacy of pesticides was introduced, and an example was used to illustrate the usage and skill of the program. [Result] The procedure could quickly and accurately con- duct statistical analysis on the field efficacy of pesticide by only inputting initial data of the test, and it could compare the significance of differences between various fac- tors. Its calculated results were consistent with the results of the specialized statisti- cal software DPS. [Conclusion] It is a quick and simple method with high accuracy and reliability, which can greatly improve the efficiency of pesticide formulation opti- mization.

On-site rapid detection of multiple pesticide residues in tea leaves by lateral flow immunoassay

The application of pesticides (mostly insecticides and fungicides) during the tea-planting process will undoubtedly increase the dietary risk associated with drinking tea. Thus, it is necessary to ascertain whether pesticide residues in tea products exceed the maximum residue limits. However, the complex matrices present in tea samples comprise a major challenge in the analytical detection of pesticide residues. In this study, nine types of lateral flow immunochromatographic strips (LFICSs) were developed to detect the pesticides of interest (fenpropathrin, chlorpyrifos, imidacloprid, thiamethoxam, acetamiprid, carbendazim, chlorothalonil, pyraclostrobin, and iprodione). To reduce the interference of tea substrates on the assay sensitivity, the pretreatment conditions for tea samples, including the extraction solvent, extraction time, and purification agent, were optimized for the simultaneous detection of these pesticides. The entire testing procedure (including pretreatment and detection) could be completed within 30 min. The detected results of authentic tea samples were confirmed by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), which suggest that the LFICS coupled with sample rapid pretreatment can be used for on-site rapid screening of the target pesticide in tea products prior to their market release.

Rules of Pesticide Use for Food Crop Diseases and Pests: A Concise Diagram Based on Correspondence Analysis

In order to ensure food security, the selection of pesticide must take into account the controlling effect and economy in the chemical control of food crop diseases and pests. Although China has registered a large number of pesticides and fungicides on food crops, traditional statistical methods cannot treat the complex relationships between crops, pests and diseases, as well as pesticides. To this end, the correspondence analysis was used to mine the data of pesticides being registered after January 1, 2010 for the prevention and control of pests and diseases on wheat, corn, and rice in China, in order to reveal the general rules of pesticide use for the prevention and control of grain crop pests and diseases and to provide scientifically recommended pesticide regimens.(1) Recommended pesticides for wheat diseases and pests: For underground pest control, phoxim, diazinon or clothianidin is recommended;imidacloprid is recommended for aphid control;avermectin is recommended for mite control;chlorpyrifos is recommended for midge control;the pesticides for rust control could be selected according to the order of epoxiconazole>flutriafol>kresoxim-methyl>cyproconazole≈hexaconazole;tebuconazole is recommended for the prevention and control of smut;difenoconazole is recommended for the simultaneous occurrence of take-all, smut and sheath blight;it is recommended to use carbendazim or thiophanate-methyl for the control of scab;and triazolone or pyraclostrobin is recommended for the control of powdery mildew.(2) Recommended pesticides for corn diseases and pests: For the control of underground pests, fipronil, carbosulfan or chlorpyrifos are recommended;thiamethoxam is recommended for control of planthoppers and corn aphids;Bacillus thuringiensis or phoxim is recommended for control of corn borers;pyraclostrobin is recommended for the control of northern leaf blight;tebuconazole is recommended for the control of head smut;and fludioxonil+metalaxyl-M is recommended for the control of corn stalk rot.(3) Recommended pesticides for rice diseases and pests: It is recommended to use triazophos, avermectin analogs or methoxyfenozide for the control of borers;for rice planthoppers, the pesticides could be selected in order of pymetrozine>imidacloprid>thiamethoxam>thiazide>nitenpyram;avermectin analogs are recommended for the control of rice leaf rollers;tebuconazole is recommended for the control of rice false smut;prochloraz and its manganese salts are recommended for the control of bakanae disease;hymexazol is recommended for the control of wilt disease;thifluzamide or hexaconazole is recommended for the control of sheath blight;and the pesticides for the control of rice blast are in order of tricyclazole>kasugamycin>fenoxanil>isoprothiolane>Bacillus subtilis. In addition, potential applications of correspondence analysis in other fields of plant protection are discussed.

Application of Laboratory Information Management System in Tea Pesticide Analysis Laboratory

The aim of this paper is to establish LIMS （laboratory information management system） for the tea pesticides analysis accredited laboratories in Taiwan. The LIMS could help Tungting station and Nantou pesticide inspection station to computerize the pesticide analysis data. It has completed eight management subsystems so far, including the basic information management subsystem, thesample processing management subsystem, the analysis data management subsystem, the analysis report management subsystem, the inspection standard management subsystem, the instrument connection management subsystem, the laboratory personnel training management subsystem and the laboratory quality document management subsystem. Using the automatic tea pesticide analysis information management system could help laboratory operations to reduce the amount of excess paperwork and human resource, which could ensure the analysis data quality is traceable and reliable.

A novel thermal biosensor based on enzyme reaction for pesticides measurement

A novel thermal biosensor based on enzyme reaction for pesticides detection has been developed. This biosensor is a flow injection analysis system and consists of two channels with enzyme reaction column and identical reference column, which is set for eliminating the unspecific heat. The enzyme reaction takes place in the enzyme reaction column at a constant temperature(40℃) realized by a thermoelectric thermostat. Thermosensor based on the thermoelectric module containing 127 serial BiTe-thermocouples is used to monitor the temperature difference between two effluents from enzyme reaction column and reference column. The ability of this biosensor to detect pesticides is demonstrated by the decreased degree of the hydrolytic heat in two types of thermosensor mode. The hydrolytic reaction is inhibited by 36% at 1 mg/L DDVP and 50 % at 10 mg/L DDVP when cell-typed thermosensor is used. The percent inhibition is 30% at 1 mg/L DDVP and 42% at 10 mg/L DDVP in tube-typed thermosensor mode. The detection for real sample shows that this biosensor can be used for detection of organophosphate pesticides residue.

Multiresidue Method for Determination of 67 Pesticides in Water Samples Using Solid-Phase Extraction with Centrifugation and Gas Chromatography-Mass Spectrometry

A new multi-residue method based on solid-phase extraction (SPE) with centrifugation was developed for determination and quantitation of 67 pesticides in water samples. Two SPE cartridges were tested: Chromabond C18 and Oasis HLB. Parameters that influence the extraction efficiency such as the eluent volume, the sample loading volume, the addition of organic solvent to water sample, sorbent drying and elute concentration were optimized. The innovation of this work was the examination of the use of a centrifugation technique in both the drying and elution steps. When combined with centrifugation, the volume of the elution solvent was reduced to 2 mL and the time for sorbent drying decreased also to 10 min under vacuum. Under the optimized conditions, this method showed good recoveries higher than 65% - 68% for the 67 analyzed pesticides using the C18 and HLB cartridges with relative standard deviations lower than 9.7% - 12.3%. Limits of quantification were between 2 and 20 ng.L–1. The simplicity of the described method, use of less of organic solvent, short procedure time, and good recoveries demonstrate the advantages of this environmentally friendly approach for routine analysis of numerous samples.

Developments in Analytical Methods for Detection of Pesticides in Environmental Samples

The present review gives a survey of all the published methods along with their advantages and limitations. Traditional methods like thin layer chromatography, gas chromatography, liquid chromatography etc are still in use for this purpose. But some recent bio-analytical methods such as immunosensors, cell based sensors etc. have also gained equal importance. This article also overviews various electro-analytical methods and their applications as detection devices when combined with FIA and biosensors. Lastly nanoparticle based biosensors have also been discussed. The review concludes with futuristic approach to reduce the risks caused by pesticides. This scrutiny should provide concise evaluation of different techniques employed for pesticide detection in environmental samples.

Application of Mass Spectrometry (MS)-coupled Techniques in Pesticide Residue Detection

Pesticide residue detection is an important work to ensure the quality safety of agricultural products.In the process of agricultural production,in order to prevent and control agricultural diseases and pests,a certain amount of pesticides need to be used.However,if pesticides are used excessively,there will be certain pesticide residues in crops and related products.Therefore,it is necessary to do a good job in pesticide residue detection.The gas chromatography-mass spectrometry(GC-MS)and liquid chromatography-mass spectrometry(LC-MS)detection methods have good results and can effectively detect pesticide residues in related products.This paper reviewed and analyzed the application of GC-MS and LC-MS in pesticide residue detection,and proposed optimization measures based on practical experience,hoping to provide reference for relevant scholars.

植物生长调节剂在花生中的应用及安全性分析

为明确花生生产中植物生长调节剂的使用情况,通过查询中国农药信息网,统计汇总花生目前有效登记调节剂种类,并查询食品安全国家标准《食品中农药最大残留限量》(GB 2763—2021)中花生中调节剂的最大残留限量和检测方法,分析花生生产中主要使用的调节剂的毒性,为下一步相关标准的制定和修订提出意见和建议,同时也为花生产业的出口创汇及高质量发展提供参考,提升中国花生产业的国际竞争力,保障中国花生产业健康可持续发展。

高粱、谷子两种谷物类杂粮用农药登记现状及分析

本文通过检索中国农药信息网数据,对登记作物为高粱和谷子的农药进行梳理。总结分析了这两种作物农药登记产品数量、有效成分、毒性、防治对象、剂型等特点,找出两种作物农药登记存在的问题,并提出相应的建议。以期为高粱和谷子两种谷物类杂粮农药登记提供参考和方向。

我国人参用农药登记现状及问题分析

人参生长周期长,生长环境特殊,栽培中病虫害问题较为突出。本文通过统计人参用农药登记情况,分析存在的问题,提出加快人参用药登记建设建议,以期为人参产业健康可持续发展提供思路。

科学研究与化学综合实验相融合的实验教学——吡虫啉农药的电化学检测

将石墨烯与壳聚糖复合材料修饰到玻碳电极表面,制备对吡虫啉具有特异性响应的电化学传感器,可对样品中吡虫啉的浓度进行定量分析检测。电分析涉及物理化学及分析化学的多个知识,将电化学传感器检测吡虫啉农药科学研究实验融入到本科化学综合实验中,不仅可以提高学生对电化学及分析化学相关理论知识的理解,同时还可以使学生了解科学前沿,培养学生的科学研究兴趣以及创新创造能力。

基于手性固定相-GC-MS的抑霉唑光学纯度分析研究

针对手性农药广泛使用、手性安全日益关注的现实问题,基于手性固定相-GC-MS构建抑霉唑光学纯度的快速分析方法。应用经过改性的二甲基硅基-β-环糊精CYCLOSIL-B手性色谱柱,基于气相色谱-质谱联用技术,对手性农药抑霉唑进行了对映异构体的分析,且在15.625~500μg·mL^(-1)的线性范围良好。同时用小鼠血浆初步验证了抑霉唑的血浆蛋白结合率实验,结果表明,其对映异构体的血浆蛋白结合率有所不同,分别为76.02%和81.41%,在生物体内存在的立体选择性差异。对抑霉唑提供了一种快速、高效、简便的光学纯度的分析方法,为农药的高效利用及手性安全提供了一定条件。

平原河网地区稻田农药脉冲输出迟滞分析研究

针对目前有关稻田施药后短期内农药的脉冲式输出过程及运移机理尚不十分明确的问题,以扬州市江都区农田水利科学研究站的试验稻田为研究区,针对稻田施药后农药面源污染物与排水的双脉冲输出过程开展高频监测,捕捉到毒死蜱、阿维菌素、三环唑和噻呋酰胺等4种水稻常用农药的脉冲式输出过程,结果显示:上述4种农药的输出浓度和负荷率峰值均发生在施药后2.5~5h内,输出脉冲特征明显.农药和排水双脉冲的相位关系受人为因素影响较大,呈现一定的随机性.对于淋溶性较好、受田间水文状况影响较大的农药(以杀菌剂三环唑和噻呋酰胺为代表),其迟滞指数分别为0.419和0.326,首次观察到较为明显的c-Q迟滞现象,该现象的发生与稻田施药先后顺序以及农药施入稻田后随水流运移到农沟水体的路径长短有关;而对挥发性较大的农药(以杀虫剂毒死蜱为代表),其迟滞系数仅为0.083,由于易受风向等不确定性因素影响未能观察到明显的迟滞现象.上述3种农药的FI值均等于或接近于1,说明排水脉冲对农药以富集作用为主.

基于CiteSpace的农药雾滴润湿展布研究进展可视化分析

为精准把握农药雾滴润湿展布领域的研究现状、热点及趋势,借助CiteSpace软件,基于CNKI和WOS数据库获得的近30年的文献样本,从发文量、国家、机构、作者、研究热点、演进趋势等方面进行可视化分析。结果表明:当前国内外关于农药雾滴润湿展布的研究均处于飞速发展阶段,年发文量呈现激增态势,2021年中、外文文献的发文量分别达到78篇和53篇,而且已形成稳定的核心作者群及发文机构,但各群体、机构间的合作关系较弱;在该领域,中、美是主要的研究国家,中国的发文量最多(109篇),但文献的影响力(中介中心性0.09)却远不如美国(中介中心性0.46);在研究热点方面,国内的研究侧重点在于探索喷施参数、雾滴行为分析、药剂选择组合等实践层面,而国际上的侧重点还包括研制新型农药物资、开发新型施药设备及技术等创新层面的研究;未来,与无人机施药技术相关的研究将会是该领域的研究热点。

铁皮石斛中农药残留分析研究进展

铁皮石斛是兰科石斛属多年生草本植物,富含膳食纤维、蛋白质、石斛多糖、多种氨基酸和微量元素等,药用历史悠久。近年来,铁皮石斛先后被收录入2020版《中国药典》和药食两用名录中,消费者对铁皮石斛的需求增加,并不断提高铁皮石斛的茎叶花等综合开发利用,也带来铁皮石斛产品的质量安全问题越来越受关注,尤其是其农药残留安全问题。农药残留不仅影响铁皮石斛的质量品质,还可能对人体健康带来潜在威胁。因此,为了全方位认识铁皮石斛农药残留问题,本文针对我国铁皮石斛上的农药登记使用情况、农药残留限量标准、农药残留检测技术和农药残留降解行为规律等方面进行综述,为后续开展铁皮石斛产品中农药残留的检测、监控和制定其质量安全监管体系提供参考。

血液灌流联合连续性血液透析在急性有机磷中毒患者中的应用效果分析

目的观察血液灌流(HP)联合血液透析对急性有机磷中毒(AOPP)患者胆碱酯酶(ChE)活性及炎症因子水平的影响。方法采用回顾性队列研究方法。选择2020年1月至2022年12月入住颍上县人民医院急诊科的73例AOPP患者作为研究对象。按治疗方案不同将患者分为HP组(31例)和HP+连续性肾脏替代治疗(CRRT)组(42例)。所有患者入科后均按照标准方案给予对症支持治疗。HP组患者入科后尽早给予HP治疗,治疗时间为2~3h,间隔24h进行1次;HP+CRRT组患者于HP结束后进行连续性静脉-静脉血液透析滤过(CVVHDF)。比较两组患者入科后(T0)、第1次HP/HP+CRRT结束时(T1)、第2次HP/HP+CRRT结束时(T2)、第3次HP/HP+CRRT结束时(T3)血清ChE、肿瘤坏死因子-α(TNF-α)、白细胞介素(IL-1、IL-6)水平,以及ChE恢复时间、中间综合征(IMS)发生率、住院时间、入住ICU率等的差异。结果随治疗时间延长,两组治疗后T1、T2、T3时ChE活性均较T0时间明显增加,TNF-α、IL-1、IL-6水平均较T0时间明显降低,T3时达到谷值,且以HP+CRRT组的变化较HP组更显著[ChE活性(U/L):2903.26±164.43比2292.98±350.96,TNF-α(ng/L):78.24±10.75比100.55±15.58,IL-1(ng/L):95.98±22.56比127.94±18.74,IL-6(ng/L):34.36±8.66比58.74±10.46均P<0.05]。HP+CRRT组ChE活性恢复时间、住院时间均较HP组明显缩短[ChE活性恢复时间(d):4.42±1.17比7.31±1.46住院时间(d):9.25±2.14比12.75±2.30,均P<0.05],IMS发生率和入住ICU率均较HP组明显降低[IMS发生率:33.33%(14/42)比61.29%(19/31),入住ICU率:9.52%(4/42)比29.03%(9/31),均P<0.05]。结论对于AOPP患者,HP+CRRT在炎症因子清除、恢复ChE活性时间、降低IMS发生率、缩短住院时间等方面均优于单纯HP治疗,可在临床推广应用。