Exposure to Environmental Toxicants and Pathogenesis of Amyotrophic Lateral Sclerosis: State of the Art and Research Perspectives

There is a broad scientific consensus that amyotrophic lateral sclerosis (ALS), a fatal neuromuscular disease, is caused by gene-environment interactions. In fact, given that only about 10% of all ALS diagnosis has a genetic basis, gene-environmental interaction may give account for the remaining percentage of cases. However, relatively little attention has been paid to environmental and lifestyle factors that may trigger the cascade of motor neuron degeneration leading to ALS, although exposure to chemicals—including lead and pesticides—agricultural environments, smoking, intense physical activity, trauma and electromagnetic fields have been associated with an increased risk of ALS. This review provides an overview of our current knowledge of potential toxic etiologies of ALS with emphasis on the role of cyanobacteria, heavy metals and pesticides as potential risk factors for developing ALS. We will summarize the most recent evidence from epidemiological studies and experimental findings from animal and cellular models, revealing that potential causal links between environmental toxicants and ALS pathogenesis have not been fully ascertained, thus justifying the need for further research.     

醋酸纤维素改性制备氨基甲酸酯超滤膜材料的研究

利用尿素对醋酸纤维素（CA）进行浸泡预处理，然后移入邻二甲苯惰性体系中进行反应。探讨合成过程中的影响因素，结果表明：预处理过程中尿素的质量分数为25％，预处理温度55℃，预处理时间5h，反应时间3．5h时，所得醋酸纤维素氨基甲酸酯（CAC）的取代度可达到0．1。FT-IR表征证明成功合成了CAC。用制备的CAC进行铸膜，CAC膜的拉伸强度及水通量要优于CA膜，并且随着取代度的提高，CAC膜的拉伸强度及水通量呈上升趋势。     

Analysing organochlorine pesticides in strawberry jams using GC-ECD,GC-MS/MS and QuEChERS sample preparation

This paper describes a comparison of adaptations of the QuEChERS (quick, easy, cheap, effective, rugged and safe) approach for the determination of 14 organochlorine pesticide (OCP) residues in strawberry jam by concurrent use of gas chromatography (GC) coupled to electron capture detector (ECD) and GC tandem mass spectrometry (GC-MS/MS). Three versions were tested based on the original QuEChERS method. The results were good (overall average of 89% recoveries with 15% RSD) using the ultrasonic bath at five spiked levels. Performance characteristics, such as accuracy, precision, linear range, limits of detection (LOD) and quantification (LOQ), were determined for each pesticide. LOD ranged from 0.8 to 8.9?µg?kg^?1; LOQ was in the range of 2.5–29.8?µg?kg^?1; and calibration curves were linear (r ^2?>?0.9970) in the whole range of the explored concentrations (5–100?µg?kg^?1). The LODs of these pesticides were much lower than the maximum residue levels (MRLs) allowed in Europe for strawberries. The method was successfully applied to the quantification of OCP in commercially available jams. The OCPs were detected lower than the LOD.     

Study on the residue and degradation of fluorine-containing pesticides in Oolong tea by using gas chromatography-mass spectrometry

The natural degradation of pyrethroids pesticides (bifenthrin and cyhalothrin) and benzoylurea pesticides (teflubenzuron, flufenoxuron and chlorfluazuron) in the leaves of Oolong tea trees and the effect of processing steps and pesticide's dose on the residue of above five pesticides in dried Oolong tea leaf samples were studied in detail by farm experiment and gas chromatography-mass spectrometry. The experimental results showed that: 1) Higher pesticide's dose used in tea planting will result in higher residue of pesticides in dried Oolong tea leaf samples, but the dose did not affect the degradation rate of pesticide. 2) The degradation of bifenthrin, cyhalothrin, teflubenzuron, flufenoxuron and chlorfluazuron in the leaves of tea trees follows zero-order kinetics with a half-life of 9.3-9.4, 10.2-10.4, 9.2-9.6, 12.1-13.5 and 7.0-8.2 days respectively, suggested that the pesticide's dose and the interval between tea picking and pesticide spraying are two key factors on the residue of fluorine-containing pesticides in dried Oolong tea leaf samples. 3) In comparison with bifenthrin, cyhalothrin, teflubenzuron and flufenoxuron, chlorfluazuron is more difficult to be remained in dried Oolong tea leaf samples. 4) The pesticide residue was not affected by the processing steps except the fermentation step in which the benzoylurea insecticides and bifentrin were partially lost or degraded. The results of this study are helpful for farmer to safely use fluorine-containing pesticides in Oolong tea planting.     

A rapid determination and extraction of three carbamate insecticides using LC-ESI-MS/MS: Application to their identification in a real river water sample

The aim of the present study was to attempt to describe a rapid procedure of purification and determination of the Zectran, Aminocarb and Bendiocarb in aqueous media using Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled to electrospray ionisation mass spectrometry (ESI). Different solids phases ODS sorbents were evaluated for the extraction of analytes in water. Sensitivity was evaluated by determining the limit of detection and recoveries of these compounds. The optimum conditions of extraction were applied for the screening of these substances in river water sample (Oued Madjerda).     

Extraction and Enrichment of Triazole and Triazine Pesticides from Honey Using Air‐Assisted Liquid–Liquid Microextraction

In the present work, an easy, fast, and effective approach is developed for the extraction and enrichment of triazole and triazine pesticides in honey by air‐assisted liquid–liquid microextraction coupled with gas chromatography‐flame ionization detection. Initially, honey is dissolved in an acetonitrile: water mixture and after that a few microliter of a less soluble organic solvent in aqueous phase is added. In order to form a cloudy solution, the extractant mixed with aqueous phase is repeatedly sucked and expelled by a syringe needle into a glass tube. After centrifugation, the sedimented phase (1 mL) is removed with a syringe and injected into de‐ionized water. By this action, the settled phase volume is reduced to 10 μL and the analytes are concentrated, too. Under optimum extraction conditions, limits of detection and quantitation for the studied pesticides are in the ranges of 2 to 5 and 6 to 17 ng/g, respectively. Extraction recoveries and enrichment factors are from 61% to 95% and 61 to 95, respectively.     

三氟乙胺盐酸盐在农药和含氟化学品中的应用进展

介绍了三氟乙胺盐酸盐的概况,对其在农药和相关含氟化学品合成中的应用进行了详细综述。     

液体农药包装复合膜结构设计研究

根据液体农药的特点及包装的要求,阐述了液体农药复合包装膜结构设计的原理及设计方法,详细论述了复合膜阻隔性的设计及热封性能的设计,并通过试验检测得出结论:液体农药复合包装膜需采用专用复合型粘接剂,不同类型的液体农药可分别采用不同结构的复合膜包装。     

Impact of Botanical Pesticides Derived from Melia azedarach and Azadirachta indica Plants on the Emission of Volatiles that Attract Parasitoids of the Diamondback Moth to Cabbage Plants

Herbivorous and carnivorous arthropods use chemical information from plants during foraging. Aqueous leaf extracts from the syringa tree Melia azedarach and commercial formulations from the neem tree Azadirachta indica, Neemix 4.5^®, were investigated for their impact on the flight response of two parasitoids, Cotesia plutellae and Diadromus collaris. Cotesia plutellae was attracted only to Plutella xylostella-infested cabbage plants in a wind tunnel after an oviposition experience. Female C. plutellae did not distinguish between P. xylostella-infested cabbage plants treated with neem and control P. xylostella-infested plants. However, females preferred infested cabbage plants that had been treated with syringa extract to control infested plants. Syringa extract on filter paper did not attract C. plutellae. This suggests that an interaction between the plant and the syringa extract enhances parasitoid attraction. Diadromus collaris was not attracted to cabbage plants in a wind tunnel and did not distinguish between caterpillar-damaged and undamaged cabbage plants. Headspace analysis revealed 49 compounds in both control cabbage plants and cabbage plants that had been treated with the syringa extract. Among these are alcohols, aldehydes, ketones, esters, terpenoids, sulfides, and an isothiocyanate. Cabbage plants that had been treated with the syringa extract emitted larger quantities of volatiles, and these increased quantities were not derived from the syringa extract. Therefore, the syringa extract seemed to induce the emission of cabbage volatiles. To our knowledge, this is the first example of a plant extract inducing the emission of plant volatiles in another plant. This interesting phenomenon likely explains the preference of C. plutellae parasitoids for cabbage plants that have been treated with syringa extracts.