Survey on Natural Radiosensitizing Agents Since 2000

Actually, radiation alone is not enough to kill tumor cells efficientlybecause of the radioresistance of tumor cells. It is well known that tumors from the samehistolog-ical origin and of the same development stage are extremely heterogeneous in theirsensitivity to radiotherapy. One of the most resistant factors to radiation is that tumor cells arecommonly hypoxic. The study on radiosensitizing agents is one of the most interesting issues intumor radiotherapeutics. These radiosensitizing agents can be classified into three main categories:natural products, synthesized chemicals and gene therapeutic agents according to their origins andtherapeutic techniques. Many radiosensitizing agents have some side-effects when they are active;so, it is important and significant to do our best to find more radiosensitizing agents with higherefficiency and lower side-effects. On the other hand, the tumor cells are easy to become resistantto older radiosensitizing agents; hence, it is urgent to develop newer radiosensitizing agents forclinics. Natural products come from plants, animals and other living beings. When serving asradiosensitizing agents in tumor radiotherapy, they are more attractive and predominant than generaldrugs. The reasons include a great resource ( especially in China) , multifunctional regulation,higher effectiveness and safer clinical effects.

Experimental Investigation on Promoting Effect of Composite Promoting Agents on Natural Gas Hydrate Formation

An experiment on effects of composite promoting agents composed of surfactants and liquid hydrocarbons on hydrate formation was conducted and the hydrate formation temperature,pressure,induction time and rate in the presence of different composite promoting agent packages were measured.The surfactants used covered sodium dodecyl sulfate(SDS),sodium dodecyl benzene sulfonate(SDBS) and 2-octyl sodium dodecyl sulfate(GC20S),and the liquid hydrocarbon additives utilized included cyclopentane(CP) and methyl cyclohexane(MCH).It appeared that all these combinations of composite promoting agents could promote hydrate formation.The type II hydrate formation conditions using composite promoting agents composed of CP and GC20S were the mildest and the induction time was the shortest;whereas the type H hydrates formation conditions using composite promoting agents composed of MCH and GC20S were the mildest and the induction time was also the shortest.

Natural Rubber-Grafted-Poly （Methyl Methacrylate）： Influence of Coagulating Agents on Properties and Appearances

Graft copolymers of MMA （methyl methacrylate） with NRL （natural rubber latex） referred to as NR-g-PMMA have been prepared using CHP （cumene hydroperoxide）/TEPA （tetraetbylenepentamine） redox initiator. 1H NMR （proton nuclear magnetic resonance） and FTIR （Fourier transform infrared） analysis have confirmed the occurrence of graft copolymerisations of MMA onto NR that containing 30% and 50% of MMA monomer. The influence of coagulating agents such as formic acid, sulfuric acid and boiling water on the coagulation of NR-g-PMMA latices were investigated. These types of coagulating agent formed compact coagulum and the effect of NR-g-PMMA compounds on cure characteristics, physical properties and appearances were reported.

Natural compounds as anticancer agents: Experimental evidence

Cancer prevention research has drawn much attention worldwide. It is believed that some types of cancer can be prevented by following a healthy life style. Cancer chemoprevention by either natural or synthetic agents is a promising route towards lowering cancer incidence.In recent years, the concept of cancer chemoprevention has evolved greatly. Experimental studies in anima models demonstrate that the reversal or suppression of premalignant lesions by chemopreventive agents is achievable. Natural occurring agents such as dietary phytochemicals, tea polyphenols and resveratrol show chemopreventive activity in animal models. Moreover,clinical trials for testing the safety and efficacy of a variety of natural agents in preventing or treating human malignancy have been ongoing. Here, we summarize experimental data on the chemopreventive or tumor suppressive effects of several natural compounds including curcumin,(-)-epigallocatechin-3-gallate, resveratrol, indole-3-carbinol, and vitamin D.

New Process for the Synthesis of A Sun-screening Agent Isooctyl P-methoxy Cinnamate

A sun-screening agent isooctyl p-methoxy cinnamate was prepared by reaction of p-methoxyl benzaldehyde with isooctyl acetate using titanium tetrachloride as catalyst. The optimum conditions are as follows： molar ratio of p-methoxyl benzaldehyde to isooctyl acetate and titanium tetrachloride is 1 ： 1.1 ： 0.5; reaction temperature is 30℃; and reaction time is 6 h. The yield of isooctyl p-methoxy cinnamate can reach 98%. The method of the synthesis of isooctyl p-methoxy cinnamate is efficient and economical.

Understanding the Effect of Zinc Oxide(ZnO)With Carbon Black Coupling Agent on Physico-Mechanical Properties in Natural Rubber Matrix

Natural rubber(NR)is not only the main compounding ingredient used to make the majority of components of tires as well as other rubber products,as it plays a significant role in ensuring that they operate well and complies with environmental standards.The applications of NR products are lim-ited to high temperatures due to the revision tendency of NR vulcanizate.To address these issues,the potential engagement of a carbon black(CB)coupling agent(CA)in the presence of metal oxide i.e.Zinc Oxide(ZnO)was investigated in an NR-based system.This CA has dual functionality on physicomechanical properties.CA has the ability to reduce hysteresis loss as well as improve anti-reversion properties and these properties thorough-ly depend on the presence of ZnO.While ZnO was added to the master formulation,a 65%improvement in reversion properties was observed.On the other hand,while ZnO fully transferred to the final formulation,bound rubber(BR)content increased by 19%,the difference in storage modulus(ΔG’)is reduced by 22%,cure rate index(CRI)improved by 14%,loss tangent(tanδ)reduced by 18%and slightly improve in elongation at break compared to control compound.Thermo-gravimetric analysis(TGA)was engaged to understand the thermal stability and degree of purity of CA.A differential Scanning Calorimeter(DSC)was used to detect the phase tran-sition of CA.Fourier Transform Infrared Spectrum(FTIR)was adopted to detect the presence of carboxyl and amine groups in the CA moiety.Payne effect,BR content and Transmission Electron Microscope(TEM)were em-ployed to investigate the micro-level dispersion of CB in the natural rubber(NR)matrix.

Research progress of anti-plant virus agents based on marine natural products

Plant virus diseases are a serious threat to food crops,vegetables,and cash crops,their prevention and control are extremely difficult,known as‘plant cancer’,and effective prevention and control agents are extremely short.Environmentally friendly natural antiviral active substances are key resources for the development of anti-plant virus drugs.Marine natural products are the most active field of new drugs and lead compounds discovery.However,there are few studies on their pesticide activities,especially their anti-plant virus activities.In the present manuscript,the latest research on anti-plant virus activity,structure-activity relationship,and mode of action of marine natural products were reviewed.It is hoped that this review will provide a useful reference for the research of anti-plant virus drugs.

Antioxidant Properties of Rosemary and Its Potential Uses as Natural Antioxidant in Dairy Products—A Review

Dairy products contain lipids rich in polyunsaturated fatty acids and their esters are easily oxidized by molecular oxygen over time. Deleterious changes in dairy products caused by lipid oxidation include not only loss of flavour or development of off-flavours, but also loss of colour, nutrient value, and the accumulation of compounds, which may be detrimental to the health of consumers. One of the most effective ways of retarding lipid oxidation in dairy products is to incorporate antioxidants. Sometimes synthetic phenolic antioxidant, butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are used to delay this oxidation. Supplementation dairy products with natural antioxidants (polyphenolic compounds) are better using than synthetic antioxidant and could be potentially. The use of rosemary as natural antioxidant in dairy products can reduce the rate of lipid oxidation and hydrolysis besides may be beneficial in increasing the shelf life of these products. This supplementation will move these products into the functional food area under new category as healthy dairy products. This literature review covers the research that has focused on rosemary as antioxidant and anti-inflammatory agent that can inhibit the lipid oxidation and have health benefits by preventing carcinogens from binding to DNA, fight and stop pain. In this review, we survey the previous studies that were conducted on the application of rosemary extract as an antioxidant to extend the shelf life and to minimize nutritional losses of dairy product.

Recent advances in the managements of type 2 diabetes mellitus and natural hypoglycemic substances

Diabetes has become a global concern at present,among which type 2 diabetes mellitus(T2DM)accounts for approximately 90%-95%of patients.T2DM is a type of metabolic disorder syndrome that results from a genetic defect,and it is based on insulin resistance and an insulin secretion disorder.The occurrence of T2DM is usually the outcome of both genetic and environmental factors and their interactions.The etiology and pathogenesis of diabetes have not been fully elucidated,and no radical therapeutic cure has been found.Patients with T2DM suffer from complications such as the development of a chronic hyperglycemic condition and even serious metabolic disorders and organ damage in the body and depression and dementia,in addition to other chronic complications.Many studies have suggested that diet is crucial in the development of diabetes and the control of blood glucose.Natural substances have the characteristics of low toxicity and few side effects and may be key to the development of diabetic health products and preventive treatments.This paper reviews the etiology,pathogenesis,risks,treatments and diets related to T2DM to summarize the types of recently available natural products,from both local and foreign sources,for lowering blood glucose at home and their application in supplementary hypoglycemic foods.The key findings and conclusions suggest that there are various known T2DM-inducing factors,including genetic and environmental factors and three types of hybrid factors.

Natural products in cosmetics

The global cosmetics market reached US$500 billion in 2017 and is expected to exceed US$800 billion by 2023,at around a 7%annual growth rate.The cosmetics industry is emerging as one of the fastest-growing industries of the past decade.Data shows that the Chinese cosmetics market was US$60 billion in 2021.It is expected to be the world’s number one consumer cosmetics market by 2050,with a size of approximately US$450 billion.The influence of social media and the internet has raised awareness of the risks associated with the usage of many chemicals in cosmetics and the health benefits of natural products derived from plants and other natural resources.As a result,the cosmetic industry is now paying more attention to natural products.The present review focus on the possible applications of natural products from various biological sources in skin care cosmetics,including topical care products,fragrances,moisturizers,UV protective,and anti-wrinkle products.In addition,the mechanisms of targets for evaluation of active ingredients in cosmetics and the possible benefits of these bioactive compounds in rejuvenation and health,and their potential role in cosmetics are also discussed.

Structure-Based Optimization and Biological Evaluation of Pancreatic Lipase Inhibitors as Novel Potential Antiobesity Agents

The unusual fused b-lactone vibralactone was isolated from cultures of the basidiomycete Boreostereum vibrans and has been shown to significantly inhibit pancreatic lipase.In this study,a structure-based lead optimization of vibralactone resulted in three series of 104 analogs,among which compound C1 exhibited the most potent inhibition of pancreatic lipase,with an IC50 value of 14 nM.This activity is more than 3000-fold higher than that of vibralactone.The effect of compound C1 on obesity was investigated using high-fat diet(HFD)-induced C57BL/6 J obese mice.Treatment with compound C1 at a dose of 100 mg/kg significantly decreased HFD-induced obesity,primarily through the improvement of metabolic parameters,such as triglyceride levels.

Antiaging agents: safe interventions to slow aging and healthy life span extension

Human longevity has increased dramatically during the past century.More than 20%of the 9 billion population of the world will exceed the age of 60 in 2050.Since the last three decades,some interventions and many preclinical studies have been found to show slowing aging and increasing the healthy lifespan of organisms from yeast,flies,rodents to nonhuman primates.The interventions are classified into two groups:lifestyle modifications and pharmacological/genetic manipulations.Some genetic pathways have been characterized to have a specific role in controlling aging and lifespan.Thus,all genes in the pathways are potential antiaging targets.Currently,many antiaging compounds target the calorie-restriction mimetic,autophagy induction,and putative enhancement of cell regeneration,epige-netic modulation of gene activity such as inhibition of histone deacetylases and DNA methyltransferases,are under development.It appears evident that the exploration of new targets for these antiaging agents based on biogeron-tological research provides an incredible opportunity for the healthcare and pharmaceutical industries.The present review focus on the properties of slow aging and healthy life span extension of natural products from various biologi-cal resources,endogenous substances,drugs,and synthetic compounds,as well as the mechanisms of targets for antiaging evaluation.These bioactive compounds that could benefit healthy aging and the potential role of life span extension are discussed.

Natural Ageing Tests to Study In-service Different Facade Solutions--ETICS and Premixed One-Coat Rendered Walls

In situ testing provides accurate characterization of existing degradation mechanisms of materials and building systems which helps reducing the subjectivity of visual inspections especially when ageing under natural ageing conditions is carried out over significant periods of time. In this work, data collected from field experimental campaigns over 10 years after construction using several premixed one-coat rendered walls and over 4 and 6 years after construction in the case of ETICS （external thermal insulation composite systems） are presented and discussed. The influence of hydrophobic agents on the performance of both types of facades in terms of surface condition and water penetration was assessed by visual inspections, Karsten test and capillary tests. Additionally, adhesion tests and subsequent evaluation of porosity were also carried out for premixed one-coat mortars. The results obtained have shown that ageing of the rendering solutions, especially after 5 or 6 years in-service, results from the loss of resistance to liquid water penetration, especially at the surface. Yet, additional mechanisms such as leaching of hydrophobic agents and photochemical degradation are thought to be involved, too. Moreover, the results obtained using the Karsten test proved to be the most reliable method to determine the loss of water penetration resistance and predict the ageing of facade solutions. The information collected and the correlations established can help developing solutions to prevent early ageing and implement appropriate maintenance plans to delay their effect.

基于Multi-agent技术的Web文本挖掘模型及应用

介绍了一个基于Multi-agent技术的Web文本挖掘模型,该模型利用多智能体技术,将文本挖掘和多维文件分析技术结合起来实现了文档收集、预处理、分类、聚类等功能。最后给出了根据该模型设计和实现的某企业人才素质评价系统的实例,系统运行结果证明了模型的有效性和科学性。

土壤中铬价态转化的影响因素与作用机制研究进展

土壤中铬(Cr)污染是全球性环境问题,六价铬Cr(Ⅵ)因其高毒性及致癌性而成为关注焦点。土壤中的Cr主要以Cr(Ⅲ)和Cr(Ⅵ)的形式存在,两者之间的转化受到诸如土壤pH值、氧化还原电位(Eh)、天然氧化还原剂、有机质和微生物的影响。随着工农业活动的增多,土壤中的Cr浓度不断增加,并通过植物吸收进入食物链等多种途径,对生态系统和人体健康构成威胁。本文对Cr在全球范围内的污染现状及来源、土壤中Cr的不同价态及其毒性特征进行了评述,并分析了pH、Eh对土壤中Cr的具体存在形态与价态的影响,及天然氧化还原剂、有机质等因素利用自身化学性质充当电子供体或受体的角色对土壤中Cr价态进行转化的氧化还原机理,以及不同影响因素之间的相互作用关系,从而可以全面理解土壤中Cr价态转化的行为机制。此外,在对Cr价态影响因素深入了解的基础上,总结了以生物炭和纳米材料为代表的先进修复技术方法,这些材料和方法由于能够将Cr(Ⅵ)有效地还原为毒性较小的Cr(Ⅲ),从而降低生态环境风险,因而是一类具有巨大潜在应用价值的修复材料和修复方法,但大规模应用的可行性及其修复效果仍需要进一步验证。

天然气工业用户峰谷分时定价Multi-Agent仿真

引入多智能体建模方法,构建了政府、用户、燃气公司、实时监控和人机交互等5类智能体,通过智能体的协助与交互模拟由于价格变化所引起的城市天然气管网需求与运营的动态变化过程。并且以某地区为例,将1天24小时划分为峰、平、谷3个时段,按照"量大价高"的原则实施分时定价政策,模拟该地区天然气管网的运行状态。结果表明:①实施天然气峰谷分时,定价能够在保证用户和燃气公司同时获益的情况下,有效降低峰谷负荷差;②在峰、平、谷价格比例逐渐增加的过程中,用户收益是单调递增的,而燃气公司的收益是先减少后增加的,当价格比例增加到一定程度后,燃气公司才开始获益。

基于多Agent的战场角色仿真建模研究

作战仿真系统模型的复杂性主要来源于战场角色行为和战场环境的复杂性,多Agent系统是解决复杂问题的有效方法。分析作战仿真系统的模型组成和特点,结合自然环境建模,研究了基于多Agent的战场角色建模方法,描述了战场角色Agent所需的组件及其功能。设计了一种面向战场角色建模的通用Agent体系结构,并对战场角色Agent的规划、通信和协作等理论和应用问题进行了研究。

基于Agent网上答疑系统的设计与实现

目前,国内现有的网络答疑系统中尚存着一些问题,例如答疑方式单一、智能性和自主性低、知识库缺乏自我学习能力等.为解决这些问题,提出了基于自动答疑Agent和知识库学习Agent为核心的系统模型,并以《VisualFoxPro6.0程序设计》课程作为试验实例,采用Asp技术,结合Agent思想,完成了“基于Agent网络答疑系统(WASBA)”,运行结果表明设计基本达到了预期目标,实现了系统的自动答疑和系统知识库的自主学习.与同类答疑系统比较,在主动性和智能性方面有了较为明显的改进.

MicroRNAs mediate therapeutic and preventive effects of natural agents in breast cancer

MicroRNAs(miRNAs) are a set of non-coding small RNA molecules that play a critical role in regulation of protein coding genes in cells. Mi RNAs have been extensively studied as novel biomarkers, therapeutic targets, and new drugs in various human diseases. Breast cancer is a one of the leading tumor types significantly affecting women health worldwide. Over the past decade, a number of natural agents, such as paclitaxel and curcumin, have been applied for treatment and prevention of breast cancer due to their relatively low toxicity. However, the mechanisms of action have not been completely understood. Investigation on mi RNAs is able to potentially provide a novel insight into better understanding the anticancer activities of these natural products. Given that a single miRNA can target multiple genes, theoretically, those genes involved in a certain phenotype can be clustered with one or a few miRNAs. Therefore, pleiotropic activities of natural agents should be interpreted by interactions between selected miRNAs and their targets. In this review, we summarize the latest publications related to the alterations of mi RNAs by two natural agents(paclitaxel and curcumin) that are currently used in intervention of breast cancer, and conclude that the mechanism involving the regulation of miRNA expression is one of the keys to understand pleiotropic activities of natural agents.

Experimental assessments of methanol-based foaming agent in latex modified foamed binders and warm asphalt mixtures

Latex is one of the natural rubbers that is used to enhance the performance of asphalt pavement for the last few decades.The presence of latex,which is categorized as an elastomer,helps to improve pavement performance and durability.Conversely,higher viscosity of latex modified asphalt binder increases the production-temperatures of asphalt mixture,thus consuming higher energy during asphalt mixture’s production stage.In this study,the effectiveness of methanol as an energy-efficient foaming agent was assessed to reduce the viscosity and enhance the workability of the modified asphalt binder.The basic and rheological properties of the asphalt binders were determined through multiple laboratory tests including expansion ratio and half-life,rotational viscosity,softening point,torsional recovery,and dynamic shear rheometer.The properties of asphalt mixtures were assessed through the service characteristics,mechanical performance,and moisture resistance criteria.It was found that the presence of latex results in an approximately twofold higher expansion ratio and a lower half-life of the asphalt binder at about the same ratio.Through the rotational viscosity test,the application of methanol into asphalt binder decreased the viscosity and led to better workability,despite the addition of latex as an asphalt modifier.The application of methanol into asphalt binder improved the workability of mixture samples and lowered the compaction energy of the compaction process,which are the crucial criteria for a better mixing and compaction process.Methanol foamed asphalt mixtures with latex show much higher resistance to moisture damage and stiffness than control sample even though they were prepared at a lower temperature.