农药沉积利用率喷雾指示剂诱惑红的酶标仪测定方法

诱惑红是一种水溶性染料,近年来被用作农药沉积利用率测定的指示剂。诱惑红的检测方法为高效液相色谱法和分光光度法。高效液相色谱法需要专门的分析仪器,且价格昂贵,可见分光光度计法操作繁琐,试剂用量大,耗时长,均不适宜田间快速高效测定。笔者发展了诱惑红的酶标仪测定方法,简单高效,可批量检测多个样品,且准确度和精密度高,线性关系良好,514 nm检测波长下不受其他农药影响,并应用于玉米无人飞机喷雾场景下农药雾滴在玉米冠层的沉积利用率测定。     

Effects of ozone treatment on pesticide residues in food: a review

In agriculture, pesticide residues have always posed a major safety hazard to human health. With the development of agricultural production and improvements in science and technology, additional methods for degradation of pesticide residues have emerged. Amongst them, ozone treatment recently became a popular method owing to its outstanding technical advantages. This review is an in-depth analysis of the mechanisms by which ozone treatment degrades pesticide residues. The main mechanism involves direct oxidation by oxygen atoms, and indirect oxidation driven by hydroxyl radicals. The effects of ozone treatment on pesticide residues in food with respect to the ozone concentration, duration of ozone treatment, type of food, variety of pesticides, level of pesticide residues and environmental factors have been discussed. Furthermore, the impact of ozone treatment on the quality of food is highlighted. Low levels of ozone result in minor changes to the visual and sensory characteristics of food. In addition, this article discusses several restrictions surrounding the current application of ozone treatment for the degradation of pesticide residues. More specifically, the most crucial issue is the potential toxicity of ozonation byproducts generated by the process, which is also the current focus of research on ozone treatment for the degradation of pesticide residues. After weighing the advantages and disadvantages of ozone treatment, it is recommended as a method of degrading pesticide residues.     

认知闭合需要对农户规范施药行为的影响研究——基于信息加工的中介效应

文章利用辽宁省农户微观调查数据,从认知心理学角度应用结构方程模型分析了认知闭合需要对施药行为的影响机理。研究结果表明:认知闭合需要水平越高,农户施药行为越不规范。具体而言,规则性偏好和确定性偏好程度越高,其施药行为的规范性越低;心理封闭对农户施药行为没有显著影响。同时,认知闭合需要对农户施药行为具有间接影响,且在规则性偏好和确定性偏好对施药行为的间接影响中,信息加工产生了中介效应。     

Interaction of Cucurbit[7]uril with Oxime K027, Atropine,and Paraoxon: Risky or Advantageous Delivery System?

Antidotes against organophosphates often possess physicochemical properties that mitigate their passage across the blood–brain barrier. Cucurbit[7]urils may be successfully used as a drug delivery system for bisquaternary oximes and improve central nervous system targeting. The main aim of these studies was to elucidate the relationship between cucurbit[7]uril, oxime K027, atropine, and paraoxon to define potential risks or advantages of this delivery system in a complex in vivo system. For this reason, in silico (molecular docking combined with umbrella sampling simulation) and in vivo (UHPLC—pharmacokinetics, toxicokinetics; acetylcholinesterase reactivation and functional observatory battery) methods were used. Based on our results, cucurbit[7]urils affect multiple factors in organophosphates poisoning and its therapy by (i) scavenging paraoxon and preventing free fraction of this toxin from entering the brain, (ii) enhancing the availability of atropine in the central nervous system and by (iii) increasing oxime passage into the brain. In conclusion, using cucurbit[7]urils with oximes might positively impact the overall treatment effectiveness and the benefits can outweigh the potential risks.     

PCBs and OCPs in human milk and selected foods from Luqiao and Pingqiao in Zhejiang, China

This study was conducted to measure the levels of 23 PCB congeners and 6 organochlorine pesticides (OCPs) in human milk and three food types collected from Luqiao and Pingqiao in Zhejiang Province, China. An effort was also made to explore the potential health risk for the mothers and breast-fed infants living in these two localities. Luqiao was selected as the sampling site because it is the largest place for the disassembly of obsolete transformers and electrical waste in China. Pingqiao, located 100 km NW of Luqiao, is not known to be a place for any electronic or electrical waste and hence was chosen as the control site. Both localities are important agricultural places in the province. The organochlorines were measured in the samples using the GC-muECD technique. Micro-EROD bioassay method was also used as a complement of the chemical analysis to estimate the TEQ levels of dioxin-like PCBs in human milk. The data showed that the human milk, rice, hen egg, and fish samples from Luqiao were more heavily contaminated with PCBs than those from Pingqiao, suggesting that the mothers and their breast-fed infants in Luqiao tended to receive greater exposure to PCBs than those living in Pingqiao. The OCP levels in the two localities were found comparable, suggesting that the major source of contamination with these pesticides was from their agricultural uses. Significant correlation (R2 = 0.87, P<0.001) of PCB TEQs was found between the bioassay and chemical analysis method, suggesting that micro-EROD is an effective method for comprehensive determination of TEQ levels in human milk. Comparison with literature data showed that the PCB levels in milk samples from Luqiao were significantly higher than those from localities in other Chinese provinces and comparable to those in developed or industrialized countries.     

Nyctanthes arbor‐tristis leaves extract as Antagonizer of immunotoxic effects of chemical pesticides (experimental study)

Increased incidence of immunosuppression due to diseases like AIDS, drug resistant tuberculosis, malaria or exposure to chemicals, calls for general immunopotentiators or anti immunosuppressents. In our previous work while screening the chemical and biopesticides for their immunopotentiating activity, aqueous leaves extract of bio‐pesticidal plant Nyctanthes arbor‐tristis [HL(aq)] was found to be a potent immuno‐modulator. The present study was conducted to evaluate the immunorestorative or anti immunosuppressive activity of the N. arbor‐tristis leaves aqueous extract in the malathion exposed immunosuppressed mice. The immunorestorative potential of HL(aq) was evaluated by studying various immunological parameters (humoral, cell mediated immune, numerical values of immunocytes and functions of phagocytes) in HL(aq) treated or untreated malathion‐exposed mice. The results revealed that the immunological parameters which were suppressed with malathion either reverted back to normal or showed a trend towards normalacy, when treated with HL(aq) extract.     

菜心中残留毒死蜱的去除方法研究

针对我国当前蔬菜生产中由于农药的不合理使用而导致的农药残留超标的问题,开展了在对蔬菜农药的残留去除方法的研究。设计了以菜心为材料,以有机磷农药毒死蜱为研究对象,在不同时间、不同温度、不同清洗剂(清水、淘米水、洗洁精、加热、Na2CO3溶液以及Na Cl溶液等)以及不同的浓度下对菜心中毒死蜱残留去除效果的研究探讨。实验结果表明,对菜心中残留毒死蜱的去除效果是:淘米水Na2CO3洗洁精NaCl清水。     

果蔬中常见有机磷和有机氯农药残留量分析

随着社会的发展和科技的进步,人们越来越关注自身的生活质量和食品健康。近几年农作物农药的过度使用问题引起了各界的关注,虽然有些剧毒农药被相关部门禁止使用,但是人们食用的果蔬中的农药残留量的多少成为了关注的焦点。本文使用电子俘获检测器和火焰光度检测器对几种常见的但是已经被禁用的几种农药进行有机氯和有机磷的气相色谱分析,以求得到抽测果蔬中相关的农药残留信息,以检测这几种被禁止使用的农药是否有违规使用的现象。