含氟新农药前景看好

传统农药由于毒性、抗性及对环境影响等问题,受到了越来越多的质疑,开发高活性、高选择性和环境友好的新农药已是必然趋势。2004年,全球商品化的化学农药品种有579个,其中含氟农药共有67个,约占12%。在含氟农药中,除草剂28个,杀虫剂21个,杀菌剂15个。21世纪以来新开发的86个化学农药中,含氟农药34个,约占42%,含氟新农药已成为当今世界农药开发的热点。     

含氟新农药前景看好

传统农药由于毒性、抗性及对环境影响等问题,受到了越来越多的质疑,开发高活性、高选择性和环境友好的新农药已是必然趋势。2004年,全球商品化的化学农药品种有579个,其中含氟农药共有67个,约占12％。在含氟农药中,除草剂28个,杀虫剂21个,杀菌剂15个。21世纪以来新开发的86个化学农药中,含氟农药34个,约占42％,含氟新农药已成为当今世界农药开发的热点。     

农药产品中相关杂质限量

农药的相关杂质一般是指在农药生产或贮存过程中所含有对人类和环境具有明显毒害,或对适用作物产生药害,或引起农产品污染,或影响农药产品质量稳定性,或引起其他不良影响的杂质(包括异构体的比例和水等).相关杂质既是农药产品质量的重要控制项目,也是农药安全性评价的重要内容,它已成为国际组织和发达国家农药管理重点.近年来农药相关杂质的数量在逐渐增加,限量要求也变得更加严格.收集整理了联合国粮农组织FAO(共129个,其中杀虫剂45个、杀菌剂29个、除草剂和植物生长调节剂55个)、世界卫生组织WHO(35个)和欧盟EU(11个)发布的农药相关杂质名称及限量情况,共涉及农药品种176个,为提高中国农药产品质量,完善农药相关杂质限量管理提供参考依据.     

2023年我国登记的新农药特点

2023年我国共登记了10个新农药品种,其中生物农药9个(占90%),含微生物农药8个(占80%),显示微生物农药正加快发展步伐;新农药品种全部由国内企业登记,体现了我国农药制造和研发水平在迅速提高。19个新农药产品均为低毒(占42%)或微毒(占58%),剂型均是对环境友好的。低风险新农药数量的增加,优化了我国农药的品种结构。     

2020年我国登记的新农药

2020年,我国共登记了6个新农药,其中新杀虫剂登记数量最多,占50％;生物源农药占33.3％,说明生物源农药在蓬勃发展;国内登记的新农药占50％,体现了我国农药制造和研发水平在提高.6个新农药都属低毒或微毒,剂型均对环境友好.新农药的增加,将扩大低风险的农药数量,逐步优化我国的农药品种结构.     

让市场筛选优势农药品种

<正>农业部组织有关专家,根据农药品种毒性、残留限量标准、农业生产使用及风险监测等情况,对已取得正式登记的农药品种进行筛选、评估,制定并推出了2014年版《种植业生产使用低毒低残留农药主要品种名录》(以下简称《品种名录》)。从在我国取得农药登记的700余种农药有效成分中筛选出91个农药有效成分,仅占14%左右。在入选的91个农药品种中,杀虫剂29个,占32%;杀菌剂40个,占     

河北农药市场抽查标签严重不合格的276个

据河北省农药监督管理部门介绍,该省近两个月在开展农药市场产品标签抽查和农药市场专项治理中,共检查农药产品标签1 3 5 9个,涉及43 0家农药生产企业,82 0家农药经营单位,其中合格标签875个,占检查总数的64 4% ,而标签严重不合格的2 76个,占检查总数的2 0 3 % ;假冒或无农药登记证号的81个,占检查总数的6% ,其他不合格的1 2 7个,占检查总数的9 3 %。为加强农药监管,目前河北省农药检定所已陆续收回有关企业有关产品的农药登记证或农药临时登记证,并要求各违规农药生产企业拿出切实可行的整改措施,整改工作要在6月底前完成。经核查确认整改…     

农药违法行为分析及管理条例修订方向

根据农业部农药监督抽查的情况显示:在抽检的1947个农药样品中,合格样品1631个,合格率为83.8%,比2009年农药监督抽检总体合格率82.6%提高了1.2个百分点;抽检出假农药185个,占检测样品总数的9.5%,占不合格样品的58.5%。     

21世纪以来全球上市的化学农药品种综述

21世纪以来至2010年止全球共有85个农药上市品种,其中除草剂32个、杀虫剂24个、杀菌剂24个、其他类农药5个。以各大类农药为分,介绍了这些品种。     

英国：洒农药前先考证

英国农药残留委员会每季度都会检测食品中的农药残留量,并及时向社会公布。最新公布的检测结果显示,市面上的果蔬只有1.8％农药残留超标,包括苹果、茄子、卷心菜、葡萄、草莓等。农药残留委员会的负责人告诉《生命时报》记者,农药残留量取决于三个因素：农药使用剂量、农药使用时机、植物对农药的吸收情况。“其中前两个因素都是人为可以控制的,所以,英国农药使用者都必须参加培训,取得资格证书。”     

复合材料在飞机和汽车上的应用动向(二)

复合材料大量用于航空航天工业和汽车工业,特别是先进碳纤维复合材料用于飞机尤为值得注意,不久前,碳纤维复合材料只能在军用飞机用作主结构,但是,由于技术发展的进步,先进复合材料已开始在民航客机上也应用作主结构,如机身、机翼等,在民航客机上使用复合材料的决定,只有波音公司和空车公司这样的拥有雄厚的人力、财力和胆识的大飞机制造公司才可能作出,至于汽车上,主要使用玻纤增强塑料(热固性和热塑性塑料)用作车身、发动机室内零部件、车顶和进气路管;碳纤维复合材料近年来也日益增多的用于汽车上,主要用作车身外板、车门、进气路管和活门盖等。     

Gemini and Bicephalous Surfactants: A Review on Their Synthesis,Micelle Formation,and Uses

The use of surfactants in polymerization reactions is particularly important, mainly in emulsion polymerizations. Further, micelles from biocompatible surfactants find use in pharmaceutical dosage forms. This paper reviews recent developments in the synthesis of novel gemini and bicephalous surfactants, micelle formation, and their applications in polymer and nanoparticle synthesis, oil recovery, catalysis, corrosion, protein binding, and biomedical area, particularly in drug delivery.     

Physiological effects of alarm chemosignal emitted during the forced swim test

Two experiments were conducted. In the first, male rats were immersed for 25 min in fresh water or water previously swum in by another rat. Control rats were not immersed in water. Rats tested in water previously swum in by another rat were significantly less immobile than rats tested in fresh water. Water immersion resulted in significant increases in serum corticosterone, glucose, and phosphorus levels, a decrease in potassium levels, and a higher phosphorus/potassium ratio, compared to nonimmersed controls regardless of water condition. When the two water-immersed groups were compared, rats tested in previously swum water had significantly higher glucose and significantly lower potassium levels and a higher phosphorus/potassium ratio than rats tested in fresh water. Immobility times were significantly correlated with the phosphorus/potassium ratio. In the second experiment, blood gases were measured prior to testing and at 25 min after immersion in rats tested in fresh and previously swum water. Rats in soiled water hypoventilated to a significantly greater extent than rats in fresh water but did not differ significantly in blood oxygenation. These two studies demonstrate that alarm chemosignals can produce physiological effects in conspecifics.     

污泥生物炭中氮硫行为及环境效应研究进展

污泥生物炭中氮硫元素含量高,其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中,研究者往往以富碳生物炭作为主要研究对象,关注碳对全球气候变化的行为和功效,而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程,再到生物炭的老化,逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述,并对未来应注重开展的研究方向进行展望,为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明,污泥中氮元素含量普遍高于硫元素,且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加,在三相产物中的分配都是炭中持续减少,油中先增后减,气中一直增加。高温（＞800℃）条件下,气相中的氮含量高于固相,而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明,污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。     

H-Ferritin Produced by Myeloid Cells Is Released to the Circulation and Plays a Major Role in Liver Iron Distribution during Infection

During infections, the host redistributes iron in order to starve pathogens from this nutrient. Several proteins are involved in iron absorption, transport, and storage. Ferritin is the most important iron storage protein. It is composed of variable proportions of two peptides, the L- and H-ferritins (FTL and FTH). We previously showed that macrophages increase their expression of FTH1 when they are infected in vitro with Mycobacterium avium, without a significant increase in FTL. In this work, we investigated the role of macrophage FTH1 in M. avium infection in vivo. We found that mice deficient in FTH1 in myeloid cells are more resistant to M. avium infection, presenting lower bacterial loads and lower levels of proinflammatory cytokines than wild-type littermates, due to the lower levels of available iron in the tissues. Importantly, we also found that FTH1 produced by myeloid cells in response to infection may be found in circulation and that it plays a key role in iron redistribution. Specifically, in the absence of FTH1 in myeloid cells, increased expression of ferroportin is observed in liver granulomas and increased iron accumulation occurs in hepatocytes. These results highlight the importance of FTH1 expression in myeloid cells for iron redistribution during infection.     

Trehalose Metabolism: From Osmoprotection to Signaling

Trehalose is a non-reducing disaccharide formed by two glucose molecules. It is widely distributed in Nature and has been isolated from certain species of bacteria, fungi, invertebrates and plants, which are capable of surviving in a dehydrated state for months or years and subsequently being revived after a few hours of being in contact with water. This disaccharide has many biotechnological applications, as its physicochemical properties allow it to be used to preserve foods, enzymes, vaccines, cells etc., in a dehydrated state at room temperature. One of the most striking findings a decade ago was the discovery of the genes involved in trehalose biosynthesis, present in a great number of organisms that do not accumulate trehalose to significant levels. In plants, this disaccharide has diverse functions and plays an essential role in various stages of development, for example in the formation of the embryo and in flowering. Trehalose also appears to be involved in the regulation of carbon metabolism and photosynthesis. Recently it has been discovered that this sugar plays an important role in plant-microorganism interactions.     

木质素在超临界甲醇和乙醇溶剂中液化过程分析

通过研究木质素分别在超临界甲醇和乙醇溶剂中的液化过程，分析反应温度（260～340℃）及反应时间（0～120min）对木质素在两种溶剂中的转化率、生物油收率及其组分差异的影响。实验表明，木质素在超临界乙醇中的转化率及产物收率均高于甲醇。当反应温度340℃，反应时间60min，木质素在超临界乙醇中的转化率和生物油收率比在甲醇中分别提高了16.23%和11.54%，残渣收率降低了16.23%。通过GC-MS和FTIR对生物油和残渣分析，发现生物油组分中芳香族化合物相对含量较高，在甲醇和乙醇溶剂中分别达到66.13%和58.84%；随着反应时间的延长，甲醇溶剂中残渣的醚键官能团逐渐增强，而在乙醇溶剂中则先增强后减弱。分析认为在木质素降解过程中，超临界乙醇和甲醇均可产生氢自由基作为供氢体，攻击木质素及其大分子片段中的官能团，同时使液化产物中的活性片段减活，减弱重聚合反应，从而更利于芳烃产物的生成。而甲醇在液化过程中容易与木质素断键产生的苯酚中间体发生脱氢缩合反应，通过醚键聚合产生长链芳香族化合物，形成残渣，降低生物油收率。     

Fertility-Sparing Approaches in Atypical Endometrial Hyperplasia and Endometrial Cancer Patients: Current Evidence and Future Directions

Endometrial cancer (EC) is the fourth most common cancer in women in developed countries. Although it is usually diagnosed in postmenopausal women, its incidence has increased in young women, as well in recent decades, with an estimated rate of 4% in those under 40 years of age. Factors involved in this increase, particularly in resource-rich countries, include delayed childbearing and the rise in obesity. The new molecular classification of EC should help to personalize treatment, through appropriate candidate selection. With the currently available evidence, the use of oral progestin either alone or in combination with other drugs such as metformin, levonorgestrel-releasing intrauterine devices and hysteroscopic resection, seems to be feasible and safe in women with early-stage EC limited to the endometrium. However, there is a lack of high-quality evidence of the efficacy and safety of conservative management in EC. Randomized clinical trials in younger women and obese patients are currently underway.     

Exosomal Cargo May Hold the Key to Improving Reproductive Outcomes in Dairy Cows

The reproductive status of dairy cows remains a challenge for dairy farmers worldwide, with impaired fertility linked to a significant reduction in herd profitability, due in part to impaired immunity, increased metabolic pressure, and longer postpartum anestrous interval (PPAI). Exosomes are nanovesicles released from a variety of cell types and end up in circulation, and carry proteins, bioactive peptides, lipids, and nucleic acids specific to the place of origin. As such, their role in health and disease has been investigated in humans and animals. This review discusses research into exosomes in the context of reproduction in dairy herds and introduces recent advances in mass-spectrometry (MS) based proteomics that have a potential to advance quantitative profiling of exosomal protein cargo in a search for early biomarkers of cattle fertility.