Review on mechanisms and structure-activity relationship of hypoglycemic effects of polysaccharides from natural resources

Diabetes mellitus(DM)is a common multifactorial disease,causing various complications,such as chronic metabolism.The current therapies for diabetes mellitus are commercial diabetic drugs that have different definite side effect.However,polysaccharides mainly extracted from natural resources,have advantages of safety,accessibility,and anti-diabetic potential.We have summarized recent research of natural polysaccharides with hypoglycemic activities,focusing on different pharmacological mechanisms in various cell and animal models.The relationships of structure-hypoglycemic effect are also discussed in detail.This review could provide a comprehensive perspective for better understanding on development and mechanism of natural polysaccharides against diabetes mellitus,which have been required by clinical studies yet.

A novel binary effective medium model to describe the prepeak stressstrain relationship of combined bodies of rock-like material and rock

Combined bodies of rock-like material and rock are widely encountered in geotechnical engineering,such as tunnels and mines.The existing theoretical models describing the stress-strain relationship of a combined body lack a binary feature.Based on effective medium theory,this paper presents the governing equation of the“elastic modulus”for combined and single bodies under triaxial compressive tests.A binary effective medium model is then established.Based on the compressive experiment of concretegranite combined bodies,the feasibility of determining the stress threshold based on crack axial strain is discussed,and the model is verified.The model is further extended to coal-rock combined bodies of more diverse types,and the variation laws of the compressive mechanical parameters are then discussed.The results show that the fitting accuracy of the model with the experimental curves of the concretegranite combined bodies and various types of coal-rock combined bodies are over 95%.The crack axial strain method can replace the crack volumetric strain method,which clarifies the physical meanings of the model parameters.The variation laws of matrix parameters and crack parameters are discussed in depth and are expected to be more widely used in geotechnical engineering.

Screening hepatoprotective effective components of Lonicerae japonica Flos based on the spectrum-effect relationship and its mechanism exploring

Lonicerae japonicae Flos(LF)is a kind of healthcare food with hepatoprotective function.This study was designed to explore the spectrum-effect relationships between UPLC fingerprints and the hepatoprotective effects of LF.Fingerprints of ten batches of LF were established by UPLC-PDA.The inhibitory levels of AST and ALT were used as pharmacological indexes,and secoxyloganin,isochlorogenic acid A and isochlorogenic acid C were screened as hepatoprotective active compounds by grey relational analysis(GRA)and partial least squares regression analysis(PLSR).Caspase-3 was obtained by network pharmacology as a key target of hepatoprotective active compounds.Molecular docking is used to explore the interaction between small molecules and proteins.This work provided a general model of the combination of UPLC-PDA and hepatoprotective effect to study the spectrum-effect relationship of LF,which can be used to considerable methods and insight for the fundamental research of the material basis of similar healthcare food.

How to conduct an acupuncture dose–effect relationship study? A discussion based on study methodology

Acupuncture therapy is widely used in the clinic,and its therapeutic effects have been proven by numerous studies.The dose–effect relationship of acupuncture is a fundamental aspect of the acupuncture research system.Recent studies found that different acupuncture dosages altered study results directly,indicating the importance of screening the optimal stimulation dosage.However,the system for studying the acupuncture dose–effect relationship is still in its infancy,and the methodology of the system needs to be improved.This review aimed to define the factors impacting acupuncture“dosage”and“effect,”and to improve the methodological system for research on the dose–effect relationship of acupuncture.By summarizing the current findings of acupuncture dose–effect studies,we discussed the vital acupuncture parameters and methodological problems that influence the relationship between acupuncture dosage and its effects.These factors consist of specific influencing factors(acupoint selection,acupuncture manipulation parameters,de qi response)and nonspecific influencing factors(comparison selection,blinding procedure,patient expectancy).Our perspectives offer suggestions for the design of acupuncture dosage–effect trials.Further studies need to be conducted to establish the methodological system and provide systematic evidence of the acupuncture dose–effect relationship.

Effects of Selenium on Fusarium Growth and Associated Fermentation Products and the Relationship with Chondrocyte Viability

This study determined the effects of selenium on the growth of Fusorium strains and the effects of products extracted from the fungal cultures on relevant indicators of chondrocytes injury.

Spectrum-Effect Relationship Between High Performance Liquid Chromatography Fingerprints and Anticoccidial Activities of a Compound Chinese Medicine

Quality control and screening of active substances in traditional Chinese medicines have been performed using fingerprint analysis. The spectrum-effect relationship between chromatography fingerprints and efficacy of herbal drugs is considered as a potentially useful method for determining active ingredients in complex mixtures. The study was designed to develop a method for determining the bioactive components of a compound Chinese medicine called Tiefeng based on spectrum-effect relationships between high-performance liquid chromatography （HPLC） fingerprints and anticoccidial activities. Four peaks of the established HPLC fingerprint indicate the main bioactive components of this medicine. In addition, pharrnacodynamic atlas was defined and used to assess the anticoccidial activity of Tiefeng from different sources for the first time. We found that the level of anticoccidial activity of Tiefeng was consistent with the degree of similarity between the pharmacodynamic atlas and chromatogram of any sample. Furthermore, effect of this medicine was related with the main active constituents, along with the origin and the harvesting time.

“Buckets effect”in the kinetics of electrocatalytic reactions

In this study,we systematically investigated the effect of proton concentration on the kinetics of the oxygen reduction reaction(ORR)on Pt(111)in acidic solutions.Experimental results demonstrate a rectangular hyperbolic relationship,i.e.,the ORR current excluding the effect of other variables increases with proton concentration and then tends to a constant value.We consider that this is caused by the limitation of ORR kinetics by the trace oxygen concentration in the solution,which determines the upper limit of ORR kinetics.A model of effective concentration is further proposed for rectangular hyperbolic relationships:when the reactant concentration is high enough to reach a critical saturation concentration,the effective reactant concentration will become a constant value.This could be due to the limited concentration of a certain reactant for reactions involving more than one reactant or the limited number of active sites available on the catalyst.Our study provides new insights into the kinetics of electrocatalytic reactions,and it is important for the proper evaluation of catalyst activity and the study of structureperformance relationships.

Spectrum-effect relationship between HPLC fingerprints and bioactive components of Radix Hedysari on increasing the peak bone mass of rat

The traditional Chinese medicine of Radix Hedysari plays an important role in invigorating gas for ascending, benefiting blood for promoting production of fluid, and promoting circulation for removing obstruction in collaterals, which is consistent with the principle of treatment for osteoporosis. This study is designed to investigate the bioactive components on increasing peak bone mass (PBM) by exploring the spectrum-effect relationship between chromatography fingerprints and effect. Multiple indicators are selected to evaluate the pharmacological activity. In fingerprints, 21 common peaks are obtained, five of which are identified. Furthermore, gray relational analysis (GRA) is a quantitative method of gray system theory and is used to describe the correlation degree of common peaks and pharmacological activities with relational value. 21 components are then divided into three different regions, of which ononin and calycosin play an extremely significant role in increasing PBM. In addition, factor analysis and hierarchical cluster analysis (HCA) are used to screen the optimal producing area for Radix Hedysari. This provides a comprehensive and efficient method to improve the quality evaluation of Radix Hedysari, confirming the bioactive components for PBM-enhancement and further develop its medicinal value.

Dose-dependent effects of pentabrominated diphenyl ethers on sexual hormone and histology of male reproductive system in rats

Polybrominated diphenyl ethers (PBDEs) used as flame retardants are widely used in a variety of consumer products, like textiles, foam and building materials. They are persistent in the environment, and increasing levels of PBDEs have been found both biota and human tissue samples. In the present study we examined the dose-dependent effects of pentabrominated diphenyl ether (PBDE-99) on the serum hormone and histology of reproductive system in male rats. 40 health 4-week-old SD rats were divided into 4 groups randomly. The treated rats were orally administered with BDE-99 at the dose of 60,120 or 180 mg/kg, while controls received equal volume of corn oil. We examined the changes of serum hormone levels, histopathology, and PCNA after 30 days exposure to BDE-99. With increasing doses of BDE-99, testis organ coefficient increased, serum hormone levels lower, PCNA positive expression reduced, and the degeneration of seminiferous epithelium were revealed in treated group. These indicators with significant dose-effect relationship showed that BDE-99 can reduce the serum sex hormone levels and cause severe degeneration of seminiferous epithelium.

More tree growth reduction due to consecutive drought and its legacy effect for a semiarid larch plantation in Northwest China

Extreme climate has increasingly led to negative impacts on forest ecosystems globally,especially in semiarid areas where forest ecosystems are more vulnerable.However,it is poorly understood how tree growth is affected by different drought events.In 2006–2009,the larch plantations in the semiarid areas of Northwest China were negatively affected by four consecutive dry years,which was a very rare phenomenon that may occur frequently under future climate warming.In this study,we analyzed the effect of these consecutive dry years on tree growth based on the data of the tree rings in the dominant layer of the forest canopy on a larch plantation.We found that the tree-ring width index(RWI)in dry years was lower than that in normal years,and it experienced a rapidly decreasing trend from 2006 to 2009(slope=-0.139 year^(-1),r=-0.94)due to water supply deficits in those dry years.Drought induced legacy effects of tree growth reduction,and consecutive dry years corresponded with greater growth reductions and legacy effects.Growth reductions and legacy effects were significantly stronger in the third and fourth consecutive dry years than that of single dry year(p<0.05),which might have been due to the cumulative stress caused by consecutive dry years.Our results showed that larch trees experienced greater tree growth reduction due to consecutive dry years and their legacy effect,and the trees had lower recovery rates after consecutive dry years.Our results highlight that consecutive dry years pose a new threat to plantations under climate warming,and thus,the effect of climate extremes on tree growth should be considered in growth models in semiarid areas.

The Relationship between the Plasmodium Falciparum Clearance and the Clinical Effect of the Case with Cerebral Malaria Treated with Artemisinin

Malaria is 1 mosquito-borne disease,which is most commonly caused by a parasite called Plasmodium falciparum(P.falciparum).Cerebral malaria is the most severe neurological complication presented in

Different mechanisms underlie similar species-area relationships in two tropical archipelagoes

Despite much research in the field of island biogeography,mechanisms regulating insular diversity remain elusive.Here,we aim to explore mechanisms underlying plant species-area relationships in two tropical archipelagoes in the South China Sea.We found positive plant species-area relationships for both coral and continental archipelagoes.However,our results showed that different mechanisms contributed to similar plant species-area relationships between the two archipelagoes.For coral islands,soil nutrients and spatial distance among communities played major roles in shaping plant community structure and species diversity.By contrast,the direct effect of island area,and to a lesser extent,soil nutrients determined plant species richness on continental islands.Intriguingly,increasing soil nutrients availability(N,P,K)had opposite effects on plant diversity between the two archipelagoes.In summary,the habitat quality effect and dispersal limitation are important for regulating plant diversity on coral islands,whereas the passive sampling effect,and to a lesser extent,the habitat quality effect are important for regulating plant diversity on continental islands.More generally,our findings indicate that island plant species-area relationships are outcomes of the interplay of both niche and neutral processes,but the driving mechanisms behind these relationships depends on the type of islands.

Research on the path of effective management of participation in joint-venture railway companies by China railway group

Purpose-Following the regional restructuring,the number of joint-venture railway companies in which the Group participates has significantly increased.This paper aims to explore the challenges faced by China Railway Group in managing participation in joint-venture railway companies.The study seeks to propose specific approaches to ensure the effective management of these companies,thereby maximizing the benefits of the regional restructuring and supporting the development of a strong transportation country and a modern infrastructure system.Design/methodology/approach-Based on the change in the shareholding relationship between China Railway Group and the joint-venture railway companies,and considering the current situation of the regional restructuring of these companies,as well as the insights from existing literature and typical case studies,this paper proposes some specific paths for effective management of joint-stock railway companies which China Railway Group participated in.Findings-The problems in participation management are the unclear dual leadership role of the party committee,the lack of discourse power,the lack of synergy between shareholders,the increasing risk of sustainable operation of the loss-making companies and the role of dispatched personnel is not fully played.Based on the theories,combined with the existing research and practical cases,the paper proposed specific approaches,such as perfecting top-level system design,maintaining the discourse power,carrying out differentiated management,arranging personnel rationally,arranging shareholders synergy,and innovating methods to provide references for China Railway Group’s subsequent management of joint venture railway companies.Originality/value-This paper contributes to the existing literature by providing a comprehensive analysis of the challenges faced by China Railway Group in managing participation in joint-venture railway companies following the regional restructuring.The study offers novel insights and practical recommendations for addressing these challenges.The findings can serve as valuable references for China Railway Group’s subsequent management of joint-venture railway companies which participated in,as well as for other stateowned enterprises facing similar challenges in managing their joint ventures.

Relationship between biological features and the SMVS's inhibitory effect on mating behavior of Nilaparvata lugens (Stal)

Our previous studies revealed that second malevibration signal (SMVS) restrained the matingbehavior of N. lugens, the influences of threebiological features (density, age, and wingform) on SMVS’s inhibitory effect were hereinstudied by playing back its record. The dura-tion of playback was 4 h. Except otherwisestatement, N. lugens tested were virginmacropterous males and females aged 4-6 d af-ter emergence, and the density was 5 pairs (5females and 5 males) of N. lugens per cage (4cm in diameter and 8 cm in height). The in-hibitory effect of SMVS was evaluated usingmating rate (i. e. the rate of females withspermatophore). The results were as follows:

收入不平衡、共享发展与居民幸福感

改革开放以来,我国经济发展取得了举世瞩目的成就,但收入不平衡和共享发展程度较低的问题仍然较为突出,这在一定程度上不利于居民幸福感的提升.采用中国家庭追踪调查数据,实证检验了收入不平衡、共享发展与居民幸福感之间的关系.研究发现,收入不平衡与居民幸福感之间存在非线性的倒U型关系,并且共享发展发挥了重要的调节效应,使得共享发展程度较高的群体对收入不平衡更加包容,而且更易发挥收入不平衡对居民幸福感的提升作用.精准扶贫、乡村振兴和社会保障支出等政策也有助于提升居民幸福感对收入不平衡的包容度.因此,政府相关部门应积极实施有效举措降低收入不平衡、多措并举提升共享发展水平并着力落实扶贫类和保障类政策,进一步提升居民家庭的幸福感,加快实现共同富裕的伟大目标.

土地经营规模、农社交易关系与合作社增收效应

基于2020年中国乡村振兴综合调查数据,运用内生转换模型实证检验农户的土地经营规模对农社交易关系的影响以及不同类型交易关系下的合作社增收效应。结果表明:土地经营规模会显著促进农户选择松散型和紧密型交易,而对准一体化交易的影响并不显著,且其影响会因农户家庭人力资本、所在村庄集体行动能力和村庄地形而具有明显的异质性。合作社增收效应与农社交易关系之间并非简单的线性关系,在紧密型交易关系下合作社具有明显的增收效应,在松散型交易关系下增收效应并不明显,在准一体化交易关系下增收效应反而会受到抑制。不同农社交易关系的合作社增收效应在不同家庭人力资本农户中没有显著差异;对于村庄集体行动能力较弱的农户,松散型交易关系下的合作社增收效应会受到抑制;对于非平原地区的农户,紧密型交易关系下的合作社增收效应较明显。

供应链金融与企业ESG表现——基于融资效应与关系效应的中介作用

以2010—2022年A股上市公司为研究样本,依托利益相关者和资源依赖等理论,针对供应链金融对ESG表现的影响及作用机理展开分析。结果表明,企业开展供应链金融能够显著提升自身的ESG表现,数字化转型程度在其中发挥正向的调节作用,该结论经过一系列稳健性检验后依然成立。机制检验发现,供应链金融主要通过融资效应与关系效应助力ESG表现的提升。异质性检验发现,国有性质、存在银企关系、融资约束程度高以及所处地区金融发展程度较低的企业,通过开展供应链金融提升自身ESG表现的效果更为显著。研究结论对于发展供应链金融业务以推动企业可持续发展、打造绿色低碳供应链具有现实意义和实践价值。

基于多维谱效关系的中药质量控制与安全性评价的研究进展

中药为宝贵的传统医学资源,但由于中药发挥药效成分不明确、中药安全性评价体系以及质量控制不够完善限制了其临床应用价值。中药不同于西药,其成分复杂、作用靶点多,一种药效的体现往往是多种成分协同作用的结果,且中药药效易受采收时节、炮制方法、不同产地以及不同配伍等的影响,所以中药的安全性评价和质量控制一直以来备受关注。本文对基于多维谱效的中药安全性评价以及质量控制进行整理,为中药安全性评价和质量控制的进一步研究提供理论支持。

牛筋草HPLC指纹图谱及抗炎活性谱效关系的研究

目的 建立牛筋草的指纹图谱并考察其体外抗炎活性的谱效关系。方法 采用高效液相色谱法(high performance liquid chromatography,HPLC)建立10批牛筋草的指纹图谱,评价其相似度并进行聚类分析和主成分分析;以二甲苯致小鼠耳肿胀模型和小鼠棉球肉芽肿模型评价其抗炎作用,并采用灰色关联度和偏最小二乘回归分析探讨指纹图谱与抗炎药效的谱效关系。结果 建立的10批牛筋草HPLC指纹图谱相似度在0.850~0.987范围内。共确定了17个共有峰,指认出其中4个成分,聚类分析和主成分分析均将10批样品分为3类。谱效关系结果发现牛筋草抗炎作用的主要相关成分有6个。结论 建立的牛筋草指纹图谱方法可行,通过谱效关系分析筛选出其具有抗炎活性的有效成分,为牛筋草抗炎作用物质基础研究提供参考。