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Failure mechanism and infrared radiation characteristic of hard siltstone induced by stratification effect 被引量:1
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作者 CHENG Yun SONG Zhanping +2 位作者 XU Zhiwei YANG Tengtian TIAN Xiaoxu 《Journal of Mountain Science》 SCIE CSCD 2024年第3期1058-1074,共17页
The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and tempora... The deformation in sedimentary rock induced by train loads has potential threat to the safe operation of tunnels. This study investigated the influence of stratification structure on the infrared radiation and temporal damage mechanism of hard siltstone. The uniaxial compression tests, coupled with acoustic emission(AE) and infrared radiation temperature(IRT) were conducted on siltstones with different stratification effects. The results revealed that the stratigraphic structure significantly affects the stress-strain response and strength degradation characteristics. The mechanical parameters exhibit anisotropy characteristics, and the stratification effect exhibits a negative correlation with the cracking stress and peak stress. The failure modes caused by the stratification effect show remarkable anisotropic features, including splitting failure(Ⅰ: 0°-22.50°, Ⅱ: 90°), composite failure(45°), and shearing failure(67.50°). The AE temporal sequences demonstrate a stepwise response characteristic to the loading stress level. The AE intensity indicates that the stress sensitivity of shearing failure and composite failure is generally greater than that of splitting failure. The IRT field has spatiotemporal migration and progressive dissimilation with stress loading and its dissimilation degree increases under higher stress levels. The stronger the stratification effect, the greater the dissimilation degree of the IRT field. The abnormal characteristic points of average infrared radiation temperature(AIRT) variance at local stress drop and peak stress can be used as early and late precursors to identify fracture instability. Theoretical analysis shows that the competitive relationship between compaction strengthening and fracturing damage intensifies the dissimilation of the infrared thermal field for an increasing stress level. The present study provides a theoretical reference for disaster warnings in hard sedimentary rock mass. 展开更多
关键词 Hard siltstone Failure mechanism Stratification effect Infrared radiation characteristic Temporal-damage mechanism DISSIMILATION
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Synergistic effects of three traditional herbs green tea,mulberry leaf and corn silk on glucose uptake level of L6 myoblasts and the hypoglycemic mechanism
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作者 Jing-Na Zhou Ming-Yue Li +4 位作者 Ting-Ting Zhang Jing-Yang Lu Min Zhang Peng-Wei Zhuang Hai-Xia Chen 《Traditional Medicine Research》 2024年第7期1-12,共12页
Background:Green tea,mulberry leaf and corn silk are traditional herbs used in the prevention and treatment of diabetes in China for a long time,but their synergistic hypoglycemic effects and mechanisms remain unclear... Background:Green tea,mulberry leaf and corn silk are traditional herbs used in the prevention and treatment of diabetes in China for a long time,but their synergistic hypoglycemic effects and mechanisms remain unclear.Methods:The effective components of green tea,mulberry leaf and corn silk were extracted and enriched.Mixture design of experiments was used to study the influences of different combinations on the cell viability and glucose uptake level of L6 myoblasts,so as to determine the optimal synergistic hypoglycemic combination.The possible hypoglycemic mechanism of the optimal synergistic combination was explored by cytotoxicity assay,glucose uptake assay,and western blot.Results:Three polyphenol enrichment fractions of the herbs,30%ethanol elution fraction of green tea(GT),50%ethanol elution fraction of mulberry leaf(ML)and 60%ethanol elution fraction of corn silk(CS)were obtained.The antioxidant activities of GT-30%,ML-50%and CS-60%were superior to those of crude extracts,and showed strong potential inα-amylase andα-glucosidase inhibition activities.The optimal synergistic combination of crude extracts G7(crude extract of green tea:crude extract of mulberry leaf:crude extract of corn silk=1:5:3),polyphenol enrichment fractions R3(GT-30%:ML-50%:CS-60%=1:7:1)and monomers X2(epigallocatechin gallate:morusin:formononetin=3:1:2)were selected,respectively.G7,R3,and X2 showed promoting effects on the cell viability and glucose uptake of L6 myoblasts within the detected concentration range.In addition,G7,R3,and X2 could increase the expression levels of p-PI3K/PI3K and p-Akt/Akt in L6 myoblasts,and promote the translocation of Glut4,but G7 and R3 showed more significant effects.Conclusion:The synergistic hypoglycemic effects of green tea,mulberry leaf and corn silk had the characteristics of multiple-components and multiple-targets with p-PI3K/PI3K,p-Akt/Akt and the translocation of Glut4 signal pathways involved.The three traditional herbs might have the potential to be combined used for the prevention and treatment of diabetes based on the synergistic hypoglycemic effects. 展开更多
关键词 green tea mulberry leaf corn silk synergistic effect type 2 diabetes mellitus mechanism
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Exploring the Long-Term Mechanism of the Construction of College Teachers’Ethics in the New Era Under the Concept of“Sanquan Education”
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作者 Jing Zuo Xiaoyue Liu 《Journal of Contemporary Educational Research》 2024年第1期140-146,共7页
This paper takes the long-term mechanism exploration of the construction of teachers’ethics in the new era under the concept of“Sanquan education,”aiming to explore how to establish a long-term mechanism of the con... This paper takes the long-term mechanism exploration of the construction of teachers’ethics in the new era under the concept of“Sanquan education,”aiming to explore how to establish a long-term mechanism of the construction to meet the needs of college education development under the background of the new era.A series of targeted measures and suggestions are put forward,including improving the system and mechanism,strengthening the education and training of teachers’ethics,and establishing the evaluation and assessment mechanism.The implementation of these measures can promote the formation of the long-term mechanism of the construction of teachers’ethics in colleges and universities,improve teachers’ethics and behavior quality,and provide strong support for the development of education in colleges and universities. 展开更多
关键词 Sanquan education ETHICS College education long-term mechanism Teacher quality
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Screening hepatoprotective effective components of Lonicerae japonica Flos based on the spectrum-effect relationship and its mechanism exploring 被引量:1
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作者 Song Wang Lin Yang +4 位作者 Ajiao Hou Songtao Liu Liu Yang Haixue Kuang Hai Jiang 《Food Science and Human Wellness》 SCIE CSCD 2023年第1期283-294,共12页
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 o... 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. 展开更多
关键词 Lonicerae japonicae Flos Hepatoprotective effect Spectrum-effect relationship Molecular docking mechanism
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Research progress on effective chemical constituents of Sijunzi Decoction and mechanism of prevention and treatment of digestive system diseases
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作者 ZHANGYu HUANG Mei-zhen +3 位作者 PAN Chun-qu RUAN Qing-ting TAN Jin-jing XIE Sheng 《Journal of Hainan Medical University》 CAS 2023年第7期75-82,共8页
Sijunzi Decoction,as one of the classic Chinese traditional prescriptions,has been used clinically by major physicians since the Song Dynasty.This article reviewed and sorted out the literature on the effective chemis... Sijunzi Decoction,as one of the classic Chinese traditional prescriptions,has been used clinically by major physicians since the Song Dynasty.This article reviewed and sorted out the literature on the effective chemistry of Sijunzi Decoction and the mechanism of its prevention and treatment of digestive system diseases.At present,its effective chemical components are derived from the saponins and flavonoids in ginseng and licorice,and are effective for gastrointestinal mucosal injury diseases and malignant digestive system.Digestive system diseases such as tumors,functional gastrointestinal diseases,non-alcoholic fatty liver,acute liver injury,and liver failure show a multi-path,multi-target effect mechanism.This article reviews the effective chemical components and research of Sijunzi Decoction and the related mechanisms of prevention and treatment of digestive system diseases,and provides valuable clues for the follow-up research of Sijunzi Decoction. 展开更多
关键词 Sijunzi Decoction effective chemical constituents mechanism of digestive system DISEASES Research progress
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Role of methoxy and C_(α)-based substituents in electrochemical oxidation mechanisms and bond cleavage selectivity of β-O-4 lignin model compounds 被引量:1
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作者 Yang Zhou Qiang Zeng +3 位作者 Hongyan He Kejia Wu Fuqiao Liu Xuehui Li 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第1期114-125,共12页
In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl gro... In order to better understand the specific substituent effects on the electrochemical oxidation process of β-O-4 bond, a series of methoxyphenyl type β-O-4 dimer model compounds with different localized methoxyl groups, including 2-(2-methoxyphenoxy)-1-phenylethanone, 2-(2-methoxyphenoxy)-1-phenylethanol, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2-methoxyphenoxy)-1-(4-methoxyphenyl)ethanol, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanone, 2-(2,6-dimethoxyphenoxy)-1-(4-methoxyphenyl)ethanol have been selected and their electrochemical properties have been studied experimentally by cyclic voltammetry, and FT-IR spectroelectrochemistry. Combining with electrolysis products distribution analysis and density functional theory calculations, oxidation mechanisms of all six model dimers have been explored. In particular, a total effect from substituents of both para-methoxy(on the aryl ring closing to Cα) and Cα-OH on the oxidation mechanisms has been clearly observed, showing a significant selectivity on the Cα-Cβbond cleavage induced by electrochemical oxidations. 展开更多
关键词 Lignin model compounds β-O-4 dimers Electrochemical oxidation Oxidation mechanisms Substituent effect
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Review on mechanisms and structure-activity relationship of hypoglycemic effects of polysaccharides from natural resources 被引量:5
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作者 Xiaolong Ji Jianhang Guo +3 位作者 Tengzheng Cao Tingting Zhang Yanqi Liu Yizhe Yan 《Food Science and Human Wellness》 SCIE CSCD 2023年第6期1969-1980,共12页
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 s... 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. 展开更多
关键词 POLYSACCHARIDES Hypoglycemic effect mechanismS Structure-activity relationship
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Rock mechanical characteristics and landscape evolutionary mechanism of the slit-type Danxia landform on the Chinese Loess Plateau
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作者 MEN Huan DING Hua +5 位作者 DENG Yahong MU Huandong HE Nainan SUN Pushuo LI Zhixu LIU Yan 《Journal of Arid Land》 SCIE CSCD 2024年第10期1327-1343,共17页
Since 2015,the newly discovered slit-type Danxia landform on the Chinese Loess Plateau has become a hot topic in the field of geomorphology worldwide.However,the relationships among its formation,evolutionary mechanis... Since 2015,the newly discovered slit-type Danxia landform on the Chinese Loess Plateau has become a hot topic in the field of geomorphology worldwide.However,the relationships among its formation,evolutionary mechanism,and mechanical characteristics of its strata and rocks are not clear.In this paper,the Ganquan canyon group is used as the research object.Basic physical and mechanical indices of sandstone in the Ganquan canyon group were measured through field investigation and indoor experiments,and the deterioration trends for the mechanical parameters of sandstone in this area under the action of infiltration,acid dry-wet cycles,and freeze-thaw cycles were revealed.Lastly,the formation and evolutionary mechanism of the slit-type Danxia landform were discussed.The results showed that:(1)The sandstone in the canyon group had a low cementation degree and weak cohesive force,which was easily weakened under the action of water,resulting in a decrease in compressive strength and elastic modulus.(2)Acidic dry-wet cycles caused the mineral composition of the sandstone to be dissolved,and the micropores continued to grow and develop until new cracks were produced.Macroscopically,the compressive strength and elastic modulus of sandstone were greatly reduced,and this damage was cumulative and staged.The greater the acidity,the greater the damage.(3)As the number of freeze-thaw cycles increased,the uniaxial compressive strength and elastic modulus of the sandstone decreased continuously.During the freeze-thaw cycle process,the growth and development of cracks were primarily in fracture mode and usually developed along parallel bedding positions.(4)The interaction of tectonic activity and lithology with different weathering processes was a key factor in the formation and evolution of the slit-type Danxia landform.In conclusion,the intricate process of weathering influenced by historical climatic fluctuations has been pivotal in shaping the topography of Danxia landform. 展开更多
关键词 landscape-forming rocks mechanical characteristics landscape-forming effects slit-type Danxia landform Loess Plateau
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Solvent transport dynamics and its effect on evolution of mechanical properties of nitrocellulose(NC)-based propellants under hot-air drying process
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作者 Enfa Fu Mingjun Yi +1 位作者 Qianling Liu Zhenggang Xiao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期262-270,共9页
Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics... Appropriate drying process with optimized controlling of drying parameters plays a vital role in the improvement of the quality and performance of propellant products.However,few research on solvent transport dynamics within NC-based propellants was reported,and its effect on the evolution of mechanical properties was not interpreted yet.This study is conducted to gain a comprehensive understanding of hot-air drying for NC-based propellants and clarify the effect of temperature on solvent transport behavior and further the change of mechanical properties during drying.The drying kinetic curves show the drying time required is decreased but the steady solvent content is increased and the drying rate is obviously increased with the increase of hot-air temperatures,indicating hot-air temperatures have a significant effect on drying kinetics.A modified drying model was established,and results show it is more appropriate to describe solvent transport behavior within NC-based propellants.Moreover,two linear equations were established to exhibit the relationship between solvent content and its effect on the change of tensile properties,and the decrease of residual solvent content causes an obvious increase of tensile strength and tensile modulus of propellant products,indicating its mechanical properties can be partly improved by adjustment of residual solvent content.The outcomes can be used to clarify solvent transport mechanisms and optimize drying process parameters of double-based gun propellants. 展开更多
关键词 Nitrocellulose-based propellants Solvent transport dynamics mechanical properties Drying kinetics effective solvent diffusion coefficient
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Exploring the mechanism of active ingredients of Smilacis Glabrae Rhizoma in treating migraine headache through network pharmacology and animal experiments
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作者 Dao-Xian Shu Yan-Yan Chen +3 位作者 Jiao-Rong Wang Ying Wang Yong-Fang Gu Yan-Xin Wang 《Integrative Medicine Discovery》 2024年第18期1-10,共10页
Background:To explore the potential mechanism of action of the active ingredients of Smilacis Glabrae Rhizoma(SGR)in the treatment of migraine using network pharmacology and in vivo experiments.Methods:Through the sea... Background:To explore the potential mechanism of action of the active ingredients of Smilacis Glabrae Rhizoma(SGR)in the treatment of migraine using network pharmacology and in vivo experiments.Methods:Through the search of Traditional Chinese Medicines Systems Pharmacology Database and Analysis Platform,Genecards,Drugbank and other databases,we obtained active ingredients,targets of SGR and related disease targets of migraine,and took the intersection for protein-protein interactions analysis.After constructing the network diagram,network topology analysis was performed to derive the core targets and key active ingredients,and Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes enrichment analyses were performed.Finally,molecular docking was performed and validated by in vivo experiments.In vivo experiments,18 male BALB/c mice were selected,and the SGR group was fed with SGR drinking tablet concentrate,and nitroglycerin injection was used to construct a mouse model of migraine.Enzyme-linked immunosorbent assay test was used to detect the levels of TNF-α,IL-1β,IL-6,and AKT1 in plasma.Results:The results showed that the core targets of SGR for the treatment of migraine were TNF-α,IL-1β,IL-6,and AKT1.These core targets and key active ingredients had better binding ability.Compared with the blank group,the number of head scratching in the model group increased.Compared with the model group,there was a significant reduction of the number of head scratching in the SGR group.In comparison with the blank group,the protein level in the plasma in the model group was markedly higher.Compared with the model group,the protein level in the SGR group was significantly lower.Conclusion:SGR has the characteristics of improving migraine based on multi-targets,multi-components and multi-pathways,and the mechanism of action may be related to the inhibition of the release of inflammatory factors,neuron protection,and interference with apoptosis and other processes. 展开更多
关键词 MIGRAINE Smilacis Glabrae Rhizoma network pharmacology molecular docking mechanism of effect
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Long-term effectiveness,outcomes and complications of bariatric surgery 被引量:1
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作者 Milena Gulinac Dimitrina Georgieva Miteva +11 位作者 Monika Peshevska-Sekulovska Ivan P Novakov Svetozar Antovic Milena Peruhova Violeta Snegarova Plamena Kabakchieva Yavor Assyov Georgi Vasilev Metodija Sekulovski Snezhina Lazova Latchezar Tomov Tsvetelina Velikova 《World Journal of Clinical Cases》 SCIE 2023年第19期4504-4512,共9页
Dietary imbalance and overeating can lead to an increasingly widespread disease-obesity.Aesthetic considerations aside,obesity is defined as an excess of adipose tissue that can lead to serious health problems and can... Dietary imbalance and overeating can lead to an increasingly widespread disease-obesity.Aesthetic considerations aside,obesity is defined as an excess of adipose tissue that can lead to serious health problems and can predispose to a number of pathological changes and clinical diseases,including diabetes;hypertension;atherosclerosis;coronary artery disease and stroke;obstructive sleep apnea;depression;weight-related arthropathies and endometrial and breast cancer.A body weight 20%above ideal for age,gender and height is a severe health risk.Bariatric surgery is a set of surgical methods to treat morbid obesity when other treatments such as diet,increased physical activity,behavioral changes and drugs have failed.The two most common procedures currently used are sleeve gastrectomy and gastric bypass.This procedure has gained popularity recently and is generally considered safe and effective.Although current data show that perioperative mortality is low and better control of comorbidities and short-term complications is achieved,more randomized trials are needed to evaluate the long-term outcomes of bariatric procedures.This review aims to synthesize and summarize the growing evidence on the long-term effectiveness,outcomes and complications of bariatric surgery. 展开更多
关键词 Bariatric surgery long-term outcomes OBESITY Roux-en-Y gastric bypass sleeve gastrectomy effectiveNESS SAFETY Quality of life
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Styrene epoxidation catalyzed by polyoxometalate/quaternary ammonium phase transfer catalysts: The effect of cation size and catalyst deactivation mechanism
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作者 Qiongna Xiao Yuyan Jiang +3 位作者 Weiqiang Yuan Jingjing Chen Haohong Li Huidong Zheng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第3期192-201,共10页
Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quater... Catalytic epoxidation of alkenes is an important type of organic reaction in chemical industry,and the deep insight into catalyst deactivation will help to develop new epoxidation process.In this work,series of quaternary ammoniums bearing different cationic sizes,i.e.MTOA+(methyltrioctylammonium,[(C_(8)H_(17))_(3)CH_(3)N]+),HTMA+(hexadecyltrimethylammonium,[(C_(16)H_(33))(CH_(3))_(3)N]+) and DMDOA+(dimethyldioctadecylammonium,[(C_(18)H_(37))_(2)(CH_(3))_(2)N]+) were incorporated with polyoxometalate (POM) anions to prepare phase transfer catalysts (PTCs),which were used in the styrene epoxidations.Among them,(MTOA)_(3)PW_(4)O_(24)exhibits the best catalytic performance judged from the highest styrene conversion rate(52%) and styrene oxide selectivity (93%),during which the styrene epoxidation conditions were optimized.Meanwhile,the deactivation mechanism of this kind of PTCs was proposed firstly,i.e.in the case of low H_(2)O_(2) content,the oxidant can only be used in the styrene epoxidation,in which the catalyst can transform into stable Keggin-type POM.But when the content of H_(2)O_(2) is higher,the excess H_(2)O_(2) can reactivate the Keggin-type POM into active (PW_(4)O_(24))_(3)-anions,which can trigger the ring-opening polymerization of styrene oxide.Consequently,the catalyst is deactivated by adhered poly(styrene oxide)irreversibly,which was determined by NMR spectra.In this situation,the active moiety{PO_(4)[WO(O_(2))_(2)]_(4)}_(3)-in phase-transfer catalytic system can break into some unidentified species with low W/P ratio with the presence of epoxides.This work will be beneficial for the design of new PTCs in alkene epoxidation in fine chemical industry. 展开更多
关键词 Phosphotungstic acid phase-transfer CATALYST Styrene epoxidation Catalyst deactivation mechanism Cation size effect
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Mechanism of Action and Therapeutic Effect of Modified Qiwei Baishu Powder in Diabetes
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作者 Jinyan Sun Kaiwen Li +1 位作者 Chunyan Sun Shichao Dong 《Journal of Clinical and Nursing Research》 2023年第3期118-123,共6页
Objective:To study the mechanism of action and therapeutic effect of modified Qiwei Baishu powder in diabetic patients.Methods:From January 2021 to January 2022,80 diabetic patients were recruited in our study and div... Objective:To study the mechanism of action and therapeutic effect of modified Qiwei Baishu powder in diabetic patients.Methods:From January 2021 to January 2022,80 diabetic patients were recruited in our study and divided into two groups by the random number table method.Group A was treated with modified Qiwei Baishu powder,whereas group B was treated with western medicine.The therapeutic effect,traditional Chinese medicine(TCM)syndrome score,blood sugar level,and incidence of adverse reaction were compared between the two groups.Result:The therapeutic effect in group A was significantly higher than that in group B(P<0.05);the TCM syndrome scores of group A were significantly lower than those of group B(P<0.05);the fasting blood glucose(FBG),2 hour-postprandial blood glucose(PBG),and glycosylated hemoglobin(HbA1c)levels of group A were significantly lower than those of group B(P<0.05);the incidence of adverse reaction in group A was significantly lower than that in group B(P<0.05).Conclusion:On the basis of western medicine,the addition of modified Qiwei Baishu powder can maintain stable blood sugar levels in patients and alleviate diabetic symptoms;thus,it is not only effective,but also safe for clinical use in diabetes. 展开更多
关键词 DIABETES Modified Qiwei Baishu powder Therapeutic effect mechanism of action
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The mechanism underlying overwintering death in poplar:the cumulative effect of effective freeze-thaw damage 被引量:4
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作者 Chengchao Yang Jiandong Peng +3 位作者 Xiaoyu Li Dejun Liang Zhiyan Yang Yan Zhang 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第1期219-229,共11页
We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conduc... We analyzed the relationships linking overwintering death and frost cracking to temperature and sunlight as well as the effects of low temperatures and freeze–thaw cycles on bud-burst rates,relative electrical conductivity,and phloem and cambial ultrastructures of poplar.Overwintering death rates of poplar were not correlated with negative accumulated temperature or winter minimum temperature.Freeze–thaw cycles caused more bud damage than constant exposure to low temperatures.Resistance to freeze–thaw cycles differed among clones,and the budburst rate decreased with increasing exposure to freeze–thaw cycles.Cold-resistant clones had the lowest relative electrical conductivity.Chloroplasts exhibited the fastest and the most obvious reaction to freeze–thaw damage,whereas a single freeze–thaw cycle caused little damage to cambium ultrastructure.Several such cycles resulted in damage to plasma membranes,severe damage to organelles,dehydration of cells and cell death.We conclude that overwintering death of poplar is mainly attributed to the accumulation of effective freeze–thaw damage beyond the limits of freeze–thaw resistance. 展开更多
关键词 effective freeze–thaw Freeze–thaw resistance mechanism Overwintering death POPULUS Ultrastructure
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An Exploration of a Systematic and Effective Mechanism of Delivering Feedback on EFL Student Writing
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作者 SU Yan-fei 《Sino-US English Teaching》 2016年第5期338-343,共6页
In China, it is widely believed that teacher feedback plays a crucial role in EFL writing course, exerting a great impact on the improvement of Chinese EFL students' writing abilities so that teachers have been requi... In China, it is widely believed that teacher feedback plays a crucial role in EFL writing course, exerting a great impact on the improvement of Chinese EFL students' writing abilities so that teachers have been required to deliver feedback on students' writings. Teachers, consequently, spare no pains to give feedback, expecting their students would make progress in their writing, but it seems that things go contrary to their wishes. Although there are various complicated factors contributing to the situation, one of the important factors lies in the teachers, a number of whom do not grasp a systematic and effective mechanism of delivering feedback on EFL student writing. Much importance has been attached to Chinese EFL student writing, however, rare attention has been paid to conducting research on concrete ways of delivering feedback on Chinese EFL student writing in China. Therefore, this paper serves to fill the gap, mainly devoting itself to exploring concrete methods of delivering teacher feedback on EFL student writing. 展开更多
关键词 teacher feedback EFL student writing a systematic and effective mechanism
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Mechanism for Increasing Effective Inputs in Urban Agriculture through Industrial Value Chain
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作者 YUN Xiao-lan Tianjin Agricultural University,Tianjin 300384,China 《Asian Agricultural Research》 2012年第3期3-6,共4页
This paper firstly introduces the value chain management thought,current situations of utilization,and connotation of mechanism for increasing effective inputs in urban agriculture through industrial value chain.On th... This paper firstly introduces the value chain management thought,current situations of utilization,and connotation of mechanism for increasing effective inputs in urban agriculture through industrial value chain.On the basis of basic idea of value chain management,this paper is to explore the mechanism for increasing effective inputs in urban agriculture through the value chain of urban agriculture linking with other industries. 展开更多
关键词 URBAN AGRICULTURE Industrial value CHAIN effective
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BanXiaXieXin decoction treating gastritis mice with drug-resistant Helicobacter pylori and its mechanism 被引量:5
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作者 Xiao-Hua Li Jia-Yin Xu +4 位作者 Xue Wang Li-Juan Liao Liang Huang Yan-Qiang Huang Zeng-Feng Zhang 《World Journal of Gastroenterology》 SCIE CAS 2023年第18期2818-2835,共18页
BACKGROUND Helicobacter pylori(H.pylori)is the main pathogen that causes a variety of upper digestive diseases.The drug resistance rate of H.pylori is increasingly higher,and the eradication rate is increasingly lower... BACKGROUND Helicobacter pylori(H.pylori)is the main pathogen that causes a variety of upper digestive diseases.The drug resistance rate of H.pylori is increasingly higher,and the eradication rate is increasingly lower.The antimicrobial resistance of H.pylori is an urgent global problem.It has been confirmed that Banxia Xiexin decoction(BXXXT)demonstrates the effects of treating gastrointestinal diseases,inhibiting H.pylori and protecting gastric mucosa.The purpose of the present study is to further explore the therapeutic effects of BXXXT on drug-resistant H.pylori.AIM To confirm that BXXXT demonstrates therapeutical effects in vivo and in vitro on gastritis mice with drug-resistant H.pylori and explain its mechanism to provide an experimental basis for promoting the application of BXXXT.METHODS The aqueous extract of BXXXT was gained by water decocting method.The inhibitory effect of the aqueous extract on H.pylori was detected by dilution in vitro;drug-resistant H.pylori cells were used to build an acute gastritis model in vivo.Thereafter,the model mice were treated with the aqueous extract of BXXXT.The amount of H.pylori colonization,the repair of gastric mucosal damage,changes of inflammatory factors,apoptosis,etc.,were assessed.In terms of mechanism exploration,the main medicinal compositions of BXXXT aqueous extract and the synergistic bacteriostatic effects they had demonstrated were analyzed using mass spectrometry;the immune function of peripheral blood cells such as CD3+T and CD4+T of mice with gastritis before and after treatment with BXXXT aqueous extract was detected using a flow cytometry;the H.pylori transcriptome and proteome after treatment with BXXXT aqueous extract were detected.Differently expressed genes were screened and verification was performed thereon with knockout expression.RESULTS The minimum inhibitory concentration of BXXXT aqueous extract against H.pylori was 256-512μg/mL.A dose of 28 mg/kg BXXXT aqueous extract treatment produced better therapeutical effects than the standard triple therapy did;the BXXXT aqueous extract have at least 11 ingredients inhibiting H.pylori,including berberine,quercetin,baicalin,luteolin,gallic acid,rosmarinic acid,aloe emodin,etc.,of which berberine,aloe emodin,luteolin and gallic acid have a synergistic effect;BXXXT aqueous extract was found to stimulate the expressions of CD3+T and CD4+T and increase the number of CD4+T/CD8+T in gastritis mice;the detection of transcriptome and proteome,quantitative polymerase chain reaction,Western blotting and knockout verification revealed that the main targets of BXXXT aqueous extract are CFAs related to urea enzymes,and CagA,VacA,etc.CONCLUSION BXXXT aqueous extract could demonstrate good therapeutic effects on drug-resistance H.pylori in vitro and in vivo and its mechanism comes down to the synergistic or additional antibacterial effects of berberine,emodin and luteolin,the main components of the extract;the extract could activate the immune function and enhance bactericidal effects;BXXXT aqueous extract,with main targets of BXXXT aqueous extract related to urease,virulence factors,etc.,could reduce the urease and virulence of H.pylori,weaken its colonization,and reduce its inflammatory damage to the gastric mucosa. 展开更多
关键词 Banxia Xiexin decoction Helicobacter pylori Drug resistance Therapeutic effects mechanism
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Combustion mechanism and control approaches of underground coal fires:a review 被引量:3
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作者 Yuntao Liang Yalan Yang +2 位作者 Sida Guo Fuchao Tian Shaofeng Wang 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第2期58-82,共25页
With the large-scale mining of coal resources,the huge economic losses and environmental problems caused by underground coal fires have become increasingly prominent,and the research on the status quo and response str... With the large-scale mining of coal resources,the huge economic losses and environmental problems caused by underground coal fires have become increasingly prominent,and the research on the status quo and response strategies of underground coal fires is of great significance to accelerate the green prevention and control of coal fires,energy conservation and emission reduction.In this paper,we summarized and sorted out the research status of underground coal fires,focused on the theoretical and technical issues such as underground coal fire combustion mechanism,multiphysics coupling effect of coal fire combustion,fire prevention and extinguishing technology for underground coal fires,and beneficial utilization technology,and described the latest research progress of the prevention and control for underground coal fire hazards.Finally,the key research problems in the field of underground coal fire hazards prevention and control were proposed in the direction of the basic theory,technology research,comprehensive management and utilization,with a view to providing ideas and solutions for the management of underground coal fires. 展开更多
关键词 Underground coal fire Combustion mechanism Multiphysics coupling effect Disaster prevention and control Turning harm into benefit Response strategy
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Intermittent disturbance mechanical behavior and fractional deterioration mechanical model of rock under complex true triaxial stress paths 被引量:3
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作者 Zhi Zheng Hongyu Xu +3 位作者 Kai Zhang Guangliang Feng Qiang Zhang Yufei Zhao 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第1期117-136,共20页
Mechanical excavation,blasting,adjacent rockburst and fracture slip that occur during mining excavation impose dynamic loads on the rock mass,leading to further fracture of damaged surrounding rock in three-dimensiona... Mechanical excavation,blasting,adjacent rockburst and fracture slip that occur during mining excavation impose dynamic loads on the rock mass,leading to further fracture of damaged surrounding rock in three-dimensional high-stress and even causing disasters.Therefore,a novel complex true triaxial static-dynamic combined loading method reflecting underground excavation damage and then frequent intermittent disturbance failure is proposed.True triaxial static compression and intermittent disturbance tests are carried out on monzogabbro.The effects of intermediate principal stress and amplitude on the strength characteristics,deformation characteristics,failure characteristics,and precursors of monzogabbro are analyzed,intermediate principal stress and amplitude increase monzogabbro strength and tensile fracture mechanism.Rapid increases in microseismic parameters during rock loading can be precursors for intermittent rock disturbance.Based on the experimental result,the new damage fractional elements and method with considering crack initiation stress and crack unstable stress as initiation and acceleration condition of intermittent disturbance irreversible deformation are proposed.A novel three-dimensional disturbance fractional deterioration model considering the intermediate principal stress effect and intermittent disturbance damage effect is established,and the model predicted results align well with the experimental results.The sensitivity of stress states and model parameters is further explored,and the intermittent disturbance behaviors at different f are predicted.This study provides valuable theoretical bases for the stability analysis of deep mining engineering under dynamic loads. 展开更多
关键词 True triaxial static and disturbance test mechanical properties Failure mechanism and precursor Intermittent disturbance effect Fractional mechanical model
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Restorative effect and mechanism of mecobalamin on sciatic nerve crush injury in mice 被引量:11
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作者 Lin Gan Minquan Qian +4 位作者 Keqin Shi Gang Chen Yanglin Gu Wei Du Guoxing Zhu 《Neural Regeneration Research》 SCIE CAS CSCD 2014年第22期1979-1984,共6页
Mecobalamin, a form of vitamin B12 containing a central metal element (cobalt), is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral... Mecobalamin, a form of vitamin B12 containing a central metal element (cobalt), is one of the most important mediators of nervous system function. In the clinic, it is often used to accelerate recovery of peripheral nerves, but its molecular mechanism remains unclear. In the present study, we performed sciatic nerve crush injury in mice, followed by daily intraperitoneal administra-tion of mecobalamin (65 μg/kg or 130 μg/kg) or saline (negative control). Walking track analysis, histomorphological examination, and quantitative real-time PCR showed that mecobalamin signiifcantly improved functional recovery of the sciatic nerve, thickened the myelin sheath in myelinated nerve ifbers, and increased the cross-sectional area of target muscle cells. Further-more, mecobalamin upregulated mRNA expression of growth associated protein 43 in nerve tissue ipsilateral to the injury, and of neurotrophic factors (nerve growth factor, brain-derived nerve growth factor and ciliary neurotrophic factor) in the L4–6 dorsal root ganglia. Our ifndings indicate that the molecular mechanism underlying the therapeutic effect of mecobalamin after sciatic nerve injury involves the upregulation of multiple neurotrophic factor genes. 展开更多
关键词 nerve regeneration peripheral nerve injury MECOBALAMIN sciatic nerve nerve repair neurotrophic factor neuroprotective effect vitamin B12 molecular mechanism gene expression neural regeneration
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