生物除草剂防治研究进展

生物除草剂（bioherbicide）是指能够有效地应用、防治特定杂草的活生物产品，在人为控制的条件下，选用能杀灭杂草的天敌，进行人工培养后获得的大剂量生物制剂。生物除草剂有两个显著的特点：一是经过人工大批量生产而获得大量生物接种体；二是淹没式应用，以达到迅速感染，并在较短时间内杀灭杂草。目前．生物除草剂大多是利用真菌，这类生物除草剂称为真菌除草剂（mycoherbicide）。随着植物病原菌的不断分离和研究，尤其是从杂草病株中筛选出来的一些植物病原菌表现出了潜在的除草活性，其研究开发成为可替代化学除草剂的新型生物除草剂。     

阿肯色大学的真菌除草剂研究——过去、现在与将来

在美国阿肯色州,杂草的生物防除研究已采用了本地的真菌病原体作为覆盖量接种液(inundative inoculum)施用于杂草群体。我们将这种方法称为杂草生物防除的真菌除草剂方法。1969年,R.J.Smith 在北方有节山黧豆[Aeschynomene virginica(L.)B.S.P.]上发现了以前未见记载的真菌病原体之后,我们开始了这种方法的研究。最后,由 Upjohn公司于1982年开发成商品化除草剂 Collego~(TM),供阿肯色水稻和大豆种植者使用。从Collego~(TM)的发现、开发直至应用的过程中,没有任何迹象表明真菌除草剂方法不能推广用于防除一年生作物或非作物区的其它杂草。不过,这种方法确有其局限性。Collego~(TM)的药效及其引起的研究兴趣,将有助于对这一杂草生物防除新方法实际潜力的评价。     

全球抗性杂草的现状

<正>在过去65年中,除草剂的应用给杂草防除带来了一场革命,使作物产量显著增加。除草剂能有效经济地防治杂草,是防除农业作物田中杂草的主要方法,取代了人工、动物和机械防除方法。和所有技术一样,除草剂也面临着挑战,包括安全、环境问题、抗性杂草的发展。杀虫剂抗性首次是在1908年被报道,杀菌剂是在1940年,由此科学家预测,抗性杂草将在20世纪40年代中期出现。然而,杂草生活周期要长于昆虫和真菌,首例除草剂抗性事     

莠去津和烟嘧磺隆对玉米田土壤微生物的影响

[目的]明确除草剂莠去津、烟嘧磺隆对土壤微生物种群数量是否有影响。[方法]采用稀释平板法和含毒介质培养法。[结果]莠去津、烟嘧磺隆对细菌的影响是抑制-促进-抑制;对真菌的影响是促进-抑制;2种除草剂对放线菌的影响不同,莠去津是抑制-促进-抑制,烟嘧磺隆对放线菌的影响是抑制-促进。土壤中筛选出的5株细菌、5株真菌、8株放线菌对2种除草剂的敏感性存在差异,有的生长明显受到抑制,有的对菌株生长起到促进作用。[结论]除草剂莠去津、烟嘧磺隆对土壤微生物影响不大,但常见菌株对除草剂敏感性差异不同。     

我国除草剂造成作物的药害与预防

我国除草剂大量应用已近50年,其中一个重要问题是经常发生作物药害,从而成为制定杂草治理措施的关键所在。根据农业实践,论述了作物药害的原因及其预防措施,如正确的除草剂使用方法、限制与禁用长残留性除草剂、使用增效剂以及作物轮作、适宜的耕作与栽培措施等。     

新书介绍

随着农药工业和农业技术的发展，我国应用除草剂的品种不断增多，应用除草剂的范围不断扩大，与杀虫剂、杀菌剂相比，除草剂对环境条件和应用技术的要求更高。若遇到气象条件不良或应用技术不当等，则除草剂的药害事故是较易发生的。除草剂的药害，既能导致作物组织结构和生理机能的变化，又能导致作物形态特征的变化。因此，通过对作物受害呈现的异常形态(即药害症状)进行鉴别，     

有机硅非离子表面活性剂(六)

介绍了非离子型有机硅表面活性剂分散在十甲基环五硅氧烷(D5)中的透明混合物的结构、特点及在彩色化妆品、皮肤护理品、防晒护理品、止汗剂和防臭剂等个人护理品中的应用,三硅氧烷的结构、特点及在除草剂、杀虫剂、杀真菌剂等农用化学品中的应用。     

我国长残效除草剂使用概况、问题及对策

长残效除草剂在我国使用面积迅速扩大，因我国农业种植规模小，轮作复杂，农民施药技术水平低。喷洒器械落后等原因，长残效除草剂对后茬作物的药害连年发生，日趋严重，已给农业生产造成严重损失，并严重影响了农业种植业结构的调整。近年来我国除草剂生产发展迅速，供过于求，调整除草剂结构时机已成熟，应对有替代品种的长残效除草剂进行淘汰，应对无替代品种的长残效除草剂划区限制使用，同时要加强农药管理、使用技术的研究、药械的更新及提高使用技术。     

北方部分地区农作物药害严重

随着种植作物规模化的发展，农田除草剂应用面积不断扩大，北方地区如吉林、内蒙古省（区）除草剂应用面积均达到3000多万亩。但是，一些地方农民对除草剂的安全使用技术缺乏了解，加之培训力度不够，技术到位率不高，违禁用药、盲目用药的现象比较突出；少数农药生产企业擅自生产和销售国家明令禁用的除草剂，随意扩大宣传除草剂品种的应用范围等，     

我国东北地区常见除草剂药害原因分析与解决方法

我国除草剂药害发生频繁，损失严重，主要原因是除草剂使用技术落后，喷雾器械不标准及使用技术不规范。应加强农药管理。注重除草剂安全性评价，对不安全的除草剂及长残留除草剂如有替代品种取消注册登记，对无替代品种限制使用；制定喷雾器械质量标准及使用技术规范；首先系统地培训技术队伍，普及规范的化学除草技术，利用内源植物生长调节剂缓解药害。     

Controlled drug delivery systems: the next 30 years

The drug delivery scientists need to reexamine the advances made during the past 60 years, analyze our current abilities, and design the future technologies that will propel us to achieve the next level of drug delivery technologies. History shows that the first generation (1G) of drug delivery research during 1950–1980 was quite productive, while the second generation (2G) technologies developed during 1980–2010 were not as prolific. The ultimate goal of drug delivery research is to develop clinically useful formulations to treat various diseases. Effective drug delivery systems can be developed by overcoming formulation barriers and/or biological barriers. The engineering approach has a limit in solving the problem, if biological difficulties are not clearly identified and understood. The third generation (3G) drug delivery systems will have to focus on understanding the biological barriers so that they can be overcome by engineering manipulation of the drug delivery systems. Advances in the next 30 years will be most accelerated by starting open dialogues without any preconceived ideas on drug delivery technologies. The new generation of drug delivery scientists needs to be aware of the successes and limitations of the existing technologies to design the new technologies for meaningful advances in the future.     

The promise of piezoelectric polymers

Recent advances provide new opportunities in the field of polymer piezoelectric materials. Piezoelectric materials provide unique insights to the fundamental understanding of the solid state. In addition, piezoelectric materials have a wide range of applications, representing billions of dollars of commercial applications. However, inorganic piezoelectric materials have limitations that polymer ferroelectric materials can overcome, if certain challenges can be addressed. This mini‐review is a practical summary of the current research and future directions in the investigation and application of piezoelectric materials with an emphasis on polymeric piezoelectric materials. We will assume that the reader is well versed in the subject of polymers, but not as familiar with piezoelectric materials. © 2018 Society of Chemical Industry     

药物共晶的合成和结构分析

药物的理化性质与其结晶形式相关,药物共晶作为一种新型的固态形式能够在不影响药物内部结构的同时改善药物的多方面性质,提高药效。通过药物共晶的定义、应用、制备方法和结构研究等方面对目前药物共晶的研究现状进行总结,为后续共晶方向的研究提供理论指导。     

Lipid-based nanoparticles for siRNA delivery in cancer therapy: paradigms and challenges

RNA interference (RNAi) is a specific gene-silencing mechanism that can be mediated by the delivery of chemical synthesized small-interfering RNA (siRNA). RNAi might constitute a novel therapeutic approach for cancer treatment because researchers can easily design siRNA molecules to inhibit, specifically and potently, the expression of any protein involved in tumor initiation and progression. Despite all the potential of siRNA as a novel class of drugs, the limited cellular uptake, low biological stability, and unfavorable pharmacokinetics of siRNAs have limited their application in the clinic. Indeed, blood nucleases easily degrade naked siRNAs, and the kidneys rapidly eliminate these molecules. Furthermore, at the level of target cells, the negative charge and hydrophilicity of siRNAs strongly impair their cellular internalization. Therefore, the translation of siRNA to the clinical setting is highly dependent on the development of an appropriate delivery system, able to ameliorate siRNA pharmacokinetic and biodistribution properties. In this regard, major advances have been achieved with lipid-based nanocarriers sterically stabilized by poly(ethylene glycol) (PEG), such as the stabilized nucleic acid lipid particles (SNALP). However, PEG has not solved all the major problems associated with siRNA delivery. In this Account, the major problems associated with PEGylated lipid-based nanoparticles, and the different strategies to overcome them are discussed. Although PEG has revolutionized the field of nanocarriers, cumulative experience has revealed that upon repeated administration, PEGylated liposomes lose their ability to circulate over long periods in the bloodstream, a phenomenon known as accelerated blood clearance. In addition, PEGylation impairs the internalization of the siRNA into the target cell and its subsequent escape from the endocytic pathway, which reduces biological activity. An interesting approach to overcome such limitations relies on the design of novel exchangeable PEG-derivatized lipids. After systemic administration, these lipids can be released from the nanoparticle surface. Moreover, the design and synthesis of novel cationic lipids that are more fusogenic and the use of internalizing targeting ligands have contributed to the emergence of novel lipid-based nanoparticles with remarkable transfection efficiency.     

Nanotechnology-Based Strategies to Overcome Current Barriers in Gene Delivery

Nanomaterials are currently being developed for the specific cell/tissue/organ delivery of genetic material. Nanomaterials are considered as non-viral vectors for gene therapy use. However, there are several requirements for developing a device small enough to become an efficient gene-delivery tool. Considering that the non-viral vectors tested so far show very low efficiency of gene delivery, there is a need to develop nanotechnology-based strategies to overcome current barriers in gene delivery. Selected nanostructures can incorporate several genetic materials, such as plasmid DNA, mRNA, and siRNA. In the field of nanotechnologies, there are still some limitations yet to be resolved for their use as gene delivery systems, such as potential toxicity and low transfection efficiency. Undeniably, novel properties at the nanoscale are essential to overcome these limitations. In this paper, we will explore the latest advances in nanotechnology in the gene delivery field.     

Detergents containing cationic hydroxyethyl cellulose: Benefits on dark garments leveraging a consumer relevant wash method

The industrial standard methods to evaluate color care of detergents leverage technical fabrics and use known dye standards from A.I.S.E. (International Association for Soaps, Detergents and Maintenance Products). This has some limitations: (1) it is not always following the latest fashion trends; (2) overall color fading of a garment is due to both dye bleeding out of the fabric as well as friction during the wash leading to fabric texture changes. The latter depends on parameters such as fabric type and surface area that could be better assessed on real garments. To overcome the above limitations, we have designed a new protocol considering the incidence of garment types, fiber and dye chemistry. Leveraging this protocol, we assessed the effect of the presence of a cationic hydroxyethyl cellulose in a commercial detergent formulation on dark fabrics/garments. Our results indicate that the commercial detergent formulation with cationic hydroxyethyl cellulose delivers dark/black color benefit.     

Increasing the Selectivity of Light-Active Antimicrobial Agents – Or How To Get a Photosensitizer to the Desired Target

Photosensitizers combine the inherent reactivity of reactive oxygen species with the sophisticated reaction control of light. Through selective targeting, these light-active molecules have the potential to overcome certain limitations in drug discovery. Ongoing advances in the synthesis and evaluation of photosensitizer conjugates with biomolecules such as antibodies, peptides, or small-molecule drugs are leading to increasingly powerful agents for the eradication of a growing number of microbial species. This review article, therefore, summarizes challenges and opportunities in the development of selective photosensitizers and their conjugates described in recent literature. This provides adequate insight for newcomers and those interested in this field.     

癌症“细菌疗法”的研究进展

目前的癌症治疗方法毒性大,定位性差且不能有效穿透癌细胞,因此治疗效果有限。基因工程细菌能够准确的定位于所有肿瘤区域而克服这些缺点,其转运机理包括特殊的趋化性,优先生长和厌氧生长。目前的研究进展包括细胞毒素释放的时序控制,前体药物的酶激活和生理活性物质的分泌。经基因改造的细菌可表达肿瘤坏死因子-α,缺氧诱导因子-1-α,抗体,白细胞介素-2和胞嘧啶脱氨酶等,这些代谢产物具有增强肿瘤治疗效果的作用。本文对癌症＂细菌疗法＂的相关研究进行综述。     

细胞Zn2+荧光探针研究进展

对近年来测定细胞内游离Zn2 的荧光探针进行较详细地评述,主要包括喹啉类、荧光素及其衍生物类、肽和蛋白类荧光探针;并对其化学规律、性质和优缺点进行了讨论。     

细胞Zn2+荧光探针研究进展

本文主要对近年来测定细胞内游离Zn2 的荧光探针进行较详细地评述,并对其化学规律、性质和其优缺点进行了讨论.