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Survey on Natural Radiosensitizing Agents Since 2000
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作者 卢佳 邵宏 《Journal of Chinese Pharmaceutical Sciences》 CAS 2003年第3期160-163,共4页
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 ar... 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. 展开更多
关键词 radiosensitizing agent natural products RADIOTHERAPY TUMOR cancer CARCINOMA
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Experimental Investigation on Promoting Effect of Composite Promoting Agents on Natural Gas Hydrate Formation 被引量:3
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作者 Wang Shuli Wei Mingjiao +1 位作者 Li Entian Zhou Shidong 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第1期20-24,共5页
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 p... 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. 展开更多
关键词 natural gas hydrates composite promoting agents phase equilibrium induction time
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Natural Rubber-Grafted-Poly (Methyl Methacrylate): Influence of Coagulating Agents on Properties and Appearances 被引量:1
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作者 Rohani Abu Bakar M. S. Fauzi 《Journal of Chemistry and Chemical Engineering》 2012年第11期962-966,共5页
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 ... 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. 展开更多
关键词 natural rubber-grafted-poly (methyl methacrylate) coagulating agent physical properties color appearance
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Natural compounds as anticancer agents: Experimental evidence
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作者 Jiao Wang Yang-Fu Jiang 《World Journal of Experimental Medicine》 2012年第3期45-57,共13页
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 ... 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. 展开更多
关键词 Cancer CHEMOPREVENTION natural agents (-)-Epigallocatechin-3-gallate RESVERATROL Curcumin VITAMIN D INDOLE-3-CARBINOL
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Tamanu Oil in Acne Management: Potential Anti-Inflammatory and Wound-Healing Properties for Scar Reduction
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作者 Rachel Marciano Alexandra Loperfito +5 位作者 Maddie Moll Allison Liu Yuna Huh Nicole Werpachowski Kelly Frasier Julia Vinagolu-Baur 《Journal of Biomedical Science and Engineering》 2024年第10期185-193,共9页
Tamanu oil, derived from the nuts of Calophyllum inophyllum, has gained increasing attention for its potential in acne management due to its purported anti-inflammatory and wound-healing properties. This analysis eval... Tamanu oil, derived from the nuts of Calophyllum inophyllum, has gained increasing attention for its potential in acne management due to its purported anti-inflammatory and wound-healing properties. This analysis evaluates the efficacy of tamanu oil in acne treatment with a specific focus on its impact on inflammation and scar reduction. The novelty of this research lies in its comprehensive analysis of tamanu oil’s dual mechanism of action: reducing acne-related inflammation and promoting the healing of acne scars. Clinical trials and laboratory analyses were conducted to assess the oil’s effectiveness in diminishing erythema, swelling, and post-acne scarring compared to conventional treatments. Preliminary findings demonstrate that tamanu oil significantly reduces inflammation and accelerates wound healing, potentially offering a promising adjunct or alternative to standard acne therapies. Future research should aim to optimize formulation and application protocols, long-term effects, and comparative therapeutic efficacy with other anti-inflammatory agents. Tamanu oil offers a novel and effective approach to acne management, with potential advantages that go beyond inflammation reduction to include enhanced scar reduction, making it a subject that warrants further investigation. 展开更多
关键词 Tamanu Oil Calophyllum inophyllum Acne Management anti-inflammatory Properties Wound Healing Acne Scars Erythema Reduction Inflammation Reduction Scar Reduction Alternative Acne Therapies natural Acne Treatments Dermatological Applications of Tamanu Oil
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New innovation of moisturizers containing non-steroidal anti-inflammatory agents for atopic dermatitis
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作者 Montree Udompataikul 《World Journal of Dermatology》 2015年第2期108-113,共6页
Atopic dermatitis is a chronic, relapsing and extremely pruritic eczematous disease which commonly affects children. The standard management consists of a combination of anti-inflammatory drugs in adjunctive with skin... Atopic dermatitis is a chronic, relapsing and extremely pruritic eczematous disease which commonly affects children. The standard management consists of a combination of anti-inflammatory drugs in adjunctive with skin care management particular moisturizer application. A concern for the side effects associated with long term use of corticosteroids has also been considered. There has been an emerging interest in moisturizer containing non-steroidal anti-inflammatory agents such as herbal extracts, vitamins, mineral and lipids. The in vitro and the in vivo studies of each agent were reviewed. The clinical study on the efficacy of moisturizers containing these agents were also demonstrated including the author's studies and clinicalexperience. These moisturizers might be considered as an alternative treatment in acute flare of mild to moderate atopic dermatitis. 展开更多
关键词 NON-STEROIDAL anti-inflammatory agents MOISTURIZER ATOPIC DERMATITIS
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Understanding the Effect of Zinc Oxide(ZnO)With Carbon Black Coupling Agent on Physico-Mechanical Properties in Natural Rubber Matrix
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作者 Koushik Pal Koushik Banerjee +2 位作者 Soumya Ghosh Chowdhury Sanjay Kumar Bhattacharyya Rabindra Mukhopadhyay 《Organic Polymer Material Research》 2022年第2期15-25,共11页
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 com... 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. 展开更多
关键词 Carbon black natural rubber Carbon black coupling agent Anti-reversion properties
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Research progress of anti-plant virus agents based on marine natural products
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作者 Hongjian Song Yuxiu Liu Qingmin Wang 《Advanced Agrochem》 2023年第1期31-38,共8页
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... 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. 展开更多
关键词 Marine natural products Anti-plant virus agents Derivatives Mode of action
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Antioxidant Properties of Rosemary and Its Potential Uses as Natural Antioxidant in Dairy Products—A Review 被引量:2
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作者 Ahmed S. Gad Ahmed F. Sayd 《Food and Nutrition Sciences》 2015年第1期179-193,共15页
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 lo... 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. 展开更多
关键词 AUTOXIDATION ROSEMARY natural ANTIOXIDANTS agent anti-inflammatory agent Functional DAIRY Products
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Natural products in cosmetics 被引量:2
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作者 Ji-Kai Liu 《Natural Products and Bioprospecting》 2022年第1期635-677,共43页
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 ... 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. 展开更多
关键词 natural products COSMETICS Skin whitening agents Skin anti-aging agents MOISTURIZERS
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Recent advances in the managements of type 2 diabetes mellitus and natural hypoglycemic substances 被引量:3
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作者 Chong Ning Yuhan Jiao +7 位作者 Jiaqi Wang Weiwei Li Jingqiu Zhou Yi-Chieh Lee Dik-Lung Ma Chung-Hang Leung Rugang Zhu Hui-Min David Wang 《Food Science and Human Wellness》 SCIE 2022年第5期1121-1133,共13页
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,... 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. 展开更多
关键词 OBESITY Type 2 diabetes mellitus Etiological agent DIET Insulin resistance natural substances
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Structure-Based Optimization and Biological Evaluation of Pancreatic Lipase Inhibitors as Novel Potential Antiobesity Agents 被引量:1
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作者 Kun Wei Gang-Qiang Wang +8 位作者 Xue Bai Yan-Fen Niu He-Ping Chen Chun-Nan Wen Zheng-Hui Li Ze-Jun Dong Zhi-Li Zuo Wen-Yong Xiong Ji-Kai Liu 《Natural Products and Bioprospecting》 CAS 2015年第3期129-157,共29页
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 optimiza... 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. 展开更多
关键词 natural products Structure optimization Antiobesity agents Pancreatic lipase inhibitors Vibralactone derivatives
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Effective anti-inflammatory phenolic compounds from dandelion:identification and mechanistic insights using UHPLC-ESI-MS/MS,fluorescence quenching and anisotropy,molecular docking and dynamics simulation 被引量:1
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作者 Hui Zou Tingting Ben +2 位作者 Ping Wu Geoffrey I.N.Waterhouse Yilun Chen 《Food Science and Human Wellness》 SCIE CSCD 2023年第6期2184-2194,共11页
This novel study identifi es the effective anti-inflammatory phenolic compounds in dandelion and provides mechanistic insights into their interactions with receptor proteins(toll-like receptor 4,TLR4;co-receptor myelo... This novel study identifi es the effective anti-inflammatory phenolic compounds in dandelion and provides mechanistic insights into their interactions with receptor proteins(toll-like receptor 4,TLR4;co-receptor myeloid differentiation protein-2,MD-2)using UHPLC-ESI-MS/MS,lipopolysaccharide(LPS)-stimulated THP-1 cell line,fluorescence quenching and anisotropy,molecular docking(single ligand and multi-ligand docking)and molecular dynamics simulation.A 50%aqueous methanol extract had a greater anti-inflammatory effect and higher chicoric acid content,compared with the 100%water and 100%methanol extracts.Chicoric acid,chlorogenic acid,methylophiopogonone A,caffeic acid,gallic acid monohydrate and 4’-O-demethylbroussonin A had relatively high binding energies and contents in all extracts.Chicoric acid competed with chlorogenic acid,4’-O-demethylbroussonin A and quercetin for MD-2.Among dandelion’s phenolics,chicoric acid most effectively hindered TLR4-MD-2 complex formation,with a quenching constant of 0.62×10^(6) L/mol for MD-2 or TLR4 at 320 K,and binding energies of-6.87 and-5.97 kcal/mol,respectively,for MD-2 and TLR4. 展开更多
关键词 Dandelion extracts Phenolic compounds binding affinity TLR4-MD-2 antagonist anti-inflammatory agent
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Antiaging agents: safe interventions to slow aging and healthy life span extension
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作者 Ji-Kai Liu 《Natural Products and Bioprospecting》 2022年第1期220-255,共36页
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 precl... 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. 展开更多
关键词 Antiaging agents Antiaging targets Healthy lifespan extension natural products Endogenous substances LONGEVITY
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Pharmacist’s Evaluation of Natural Ingredients in Topical Products for Rheumatoid Arthritis
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作者 Hanna Tillman Juliana Gassmann +4 位作者 Shelby Stensgard Alex Nguyen Nicholas Tieu Markus Melbardis Hayden Gharibyar 《Pharmacology & Pharmacy》 CAS 2022年第8期273-284,共12页
Inflammatory diseases such as rheumatoid arthritis (RA) can lead to chronic pain and joint deformity. First line treatment includes disease-modifying antirheumatic drugs (DMARDs) to slow disease progression, but RA pa... Inflammatory diseases such as rheumatoid arthritis (RA) can lead to chronic pain and joint deformity. First line treatment includes disease-modifying antirheumatic drugs (DMARDs) to slow disease progression, but RA patients are often left with debilitating symptoms. This article explores alternative topical and naturally based options to treat RA symptoms, with supporting evidence for their use. Considered options include Aloe vera, Perillyl Alcohol (POH), Aleurites moluccana, Calendula officinalis extract (quercetin), Achyranthes species, Guizhi Shaoyao Zhimu, Curcumin (turmeric), Wutou, Radix paeoniae extract (Paeoniflorin), Tripterygium wilfordii Hook F (TWHF), Capsaicin, Cannabinoids (CBD), and Berberine. Many of these products show promising data for supplemental treatment of RA through various mechanisms, with CBD and TWHF having the most robust evidence supporting their use. 展开更多
关键词 Rheumatoid Arthritis natural Ingredient Topical Treatment anti-inflammatory Alternative Treatment
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Natural Ageing Tests to Study In-service Different Facade Solutions--ETICS and Premixed One-Coat Rendered Walls
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作者 Luis Silva Ines Flores-Colen +1 位作者 Nuno Vieira Ana Barros Timmons 《Journal of Civil Engineering and Architecture》 2016年第6期667-674,共8页
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 ... 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. 展开更多
关键词 natural ageing tests faqade solutions water resistance hydrophobic agents adhesion.
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Effect of Silane Coupling Agent Concentration on Interfacial Properties of Basalt Fiber Reinforced Composites
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作者 Takao Ota 《材料科学与工程(中英文A版)》 2023年第2期36-42,共7页
The purpose of this study is to investigate the effect of the concentration of silane coupling solution on the tensile strength of basalt fiber and the interfacial properties of basalt fiber reinforced polymer composi... The purpose of this study is to investigate the effect of the concentration of silane coupling solution on the tensile strength of basalt fiber and the interfacial properties of basalt fiber reinforced polymer composites.The surface treatment of basalt fibers was carried out using an aqueous alcohol solution method.Basalt fibers were subjected to surface treatment with 3-Methacryloxypropyl trimethoxy silane at 0.5 wt.%,1 wt.%,2 wt.%,4 wt.%and 10 wt.%.The basalt monofilament tensile tests were carried out to investigate the variation in strength with the concentration of the silane coupling agent.The microdroplet test was performed to examine the effect of the concentration of the silane coupling agent on interfacial strength of basalt reinforced polymer composites.The film was formed on the surface of the basalt fiber treated silane coupling agent solution.The tensile strength of basalt fiber increased because the damaged fiber surface was repaired by the firm of silane coupling agent.The firm was effective in not only the surface protection of basalt fiber but also the improvement on the interfacial strength of fiber-matrix interface.However,the surface treatment using the high concentration silane coupling agent solution has an adverse effect on the mechanical properties of the composite materials,because of causing the degradation of the interfacial strength of the composite materials. 展开更多
关键词 natural MINERAL FIBER reinforced composites BASALT FIBER SILANE coupling agent interface fiber/matrix BOND
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基于“资源-资产-资本-资金”转化路径的森林碳汇价值实现机制
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作者 蔡为民 王燕秋 +3 位作者 林国斌 霍长宝 孙晓兵 王萌萌 《中国人口·资源与环境》 CSSCI CSCD 北大核心 2024年第3期60-67,共8页
森林碳汇价值的实现是全民所有自然资源资产所有权委托代理机制试点工作中“保值增值”“落实权益”目标实现的重要组成部分。“资源-资产-资本-资金”转化路径是在自然资源资产价值实现困局、“绿水青山就是金山银山”理念、全民所有... 森林碳汇价值的实现是全民所有自然资源资产所有权委托代理机制试点工作中“保值增值”“落实权益”目标实现的重要组成部分。“资源-资产-资本-资金”转化路径是在自然资源资产价值实现困局、“绿水青山就是金山银山”理念、全民所有自然资源资产所有权委托代理试点要求中产生的,以实现自然资源资产收益为目标的价值实现路径。因森林碳汇具备“资源”“资产”“资本”“资金”的“四资”属性,该研究提出基于“资源-资产-资本-资金”转化的森林碳汇价值实现路径,从“资源-资产-资本-资金”转化路径视角厘清制约森林碳汇价值实现的障碍机理,发现:所有权委托代理机制不明晰的问题阻碍“资源”向“资产”转化,森林碳汇产业发展滞缓的现状遏制“资产”向“资本”转化,市场机制不健全的弊病掣肘“资本”向“资金”转化,最终导致了森林碳汇价值实现进程滞缓问题。基于此,该研究构建了以政府组织为主体的森林资源资产所有权委托代理机制,以森林碳汇产业为主体的森林碳汇产业支持制度,以市场平台为主体的森林碳汇市场交易制度,共同构筑出“资源-资产-资本-资金”转化与所有者权益落实目标双向交叉赋能、协同推进的森林碳汇价值实现多维制度体系,以森林碳汇价值实现为撬动点,对明晰森林资源资产管理权责、推进资产高效配置和保值增值、显化资产所有者收益问题进行了探索,以期为自然资源资产管理制度改革提供新思路。 展开更多
关键词 自然资源资产管理 森林碳汇 价值实现 委托代理
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中国特色全民所有自然资源资产管理体系——理论与实践的协同推进
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作者 谭荣 《中国土地科学》 CSSCI CSCD 北大核心 2024年第8期1-11,共11页
研究目的:基于2024年5月“自然资源资产价值实现的理论与实践”研讨会与会者的观点,对当前中国自然资源资产管理体系进行观察、解释和展望,为建构中国特色全民所有自然资源资产管理体系提供参考。研究方法:建构央地事权分工的分析框架,... 研究目的:基于2024年5月“自然资源资产价值实现的理论与实践”研讨会与会者的观点,对当前中国自然资源资产管理体系进行观察、解释和展望,为建构中国特色全民所有自然资源资产管理体系提供参考。研究方法:建构央地事权分工的分析框架,开展观点综述和文献综述。研究结果:(1)中国自然资源资产管理实践既面临公有制、单一制的特殊性,也蕴含央地关系、激励和监管机制等知识的一般性。(2)委托代理机制是具有中国特色的央地分工机制,兼具行政委托和民事委托的优势,但不同地方表现出有差别的反馈。(3)建立健全自然资源资产价值实现机制,能够激励地方政府代理行权。中国目前已初步形成全链条式的经营管理体系。(4)建立健全纵向制约机制和横向制约机制,能够监管地方政府代理行权。中国目前已形成初步有效的监管体系。研究结论:中国特色的全民所有自然资源资产管理体系已初步建立,但仍需进一步健全差别化的央地分工机制、配置方案、价格体系、收益分配和社会监督等方面的制度建设。 展开更多
关键词 自然资源资产 委托代理 激励机制 纵向制约机制
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基于鱼群涌现行为启发的集群机器人硬注意力强化模型
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作者 刘磊 葛振业 +2 位作者 林杰 陶宇 孙俊杰 《计算机应用研究》 CSCD 北大核心 2024年第9期2737-2744,共8页
生物集群运动模型能使集群机器人涌现秩序,但是所形成的机器人自然集群秩序难以有效地被人工控制,为此提出鱼群硬注意力模型来解析实验鱼群数据中的交互行为。该模型通过编码器网络、图注意力网络、信息聚合网络、预解码网络以及最终解... 生物集群运动模型能使集群机器人涌现秩序,但是所形成的机器人自然集群秩序难以有效地被人工控制,为此提出鱼群硬注意力模型来解析实验鱼群数据中的交互行为。该模型通过编码器网络、图注意力网络、信息聚合网络、预解码网络以及最终解码网络等结构来获取焦点单体的重要邻居;再利用深度确定性策略梯度技术设计轨道强化网络与安全强化网络,以实现集群的人工控制。多智能体仿真与集群机器人实验结果表明:所提方法能够实现集群的人工轨道、安全控制,重要邻居信息为解决集群运动的强化学习难题提供了新思路,所提控制模型在无人机群空中协作、智慧农机集群作业、物流仓储多体搬运等领域具有较大的应用潜力。 展开更多
关键词 自然秩序人工控制 集群硬注意力机制 多智能体运动强化学习 集群机器人任务控制
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