Objective:The concept of constitution in traditional Chinese medicine(TCM)has been increasingly recognized as a crucial factor in both the prevention and treatment of insomnia.However,rigorous statistical evidence on ...Objective:The concept of constitution in traditional Chinese medicine(TCM)has been increasingly recognized as a crucial factor in both the prevention and treatment of insomnia.However,rigorous statistical evidence on the correlation between TCM constitutions—particularly mixed constitutions—and insomnia disorder remains limited.This study aimed to investigate the association between specific TCM constitutions and insomnia disorder.Methods:A cross-sectional study was conducted at the Department of Preventive Medicine,Yueyang Hospital of Integrated Traditional Chinese and Western Medicine,Shanghai,from November 2022 to December 2023.TCM constitutions were assessed using the Constitution in Chinese Medicine Questionnaire.Insomnia disorder was diagnosed by experienced internal medicine physicians according to the criteria of the International Classification of Sleep Disorders,Third Edition.A total of 1065 eligible participants(242 with insomnia disorder and 823 controls)were included in the final analysis.Results:Among the participants,862(80.94%)exhibited biased constitutions,with 75.30%of these having mixed constitutions.Logistic regression analysis revealed a negative association between the gentleness constitution and insomnia disorder,whereas qi-deficiency,yang-deficiency,phlegm-dampness and qidepression constitutions were positively associated with insomnia disorder.These associations remained significant after adjusting for potential confounders and were further validated through sensitivity analysis using propensity score matching.Conclusion:Significant associations between TCM constitutions and insomnia disorder were demonstrated.Future research should further investigate these relationships and explore the underlying mechanisms through rigorous longitudinal and interventional studies to improve understanding and clinical applications.展开更多
OBJECTIVE:To utilize the Traditional Chinese Medicine constitution(TCMC)as a complementary and alternative approach for early disease detection and treatment,with a focus on Yin and Yang deficiency constitutions,which...OBJECTIVE:To utilize the Traditional Chinese Medicine constitution(TCMC)as a complementary and alternative approach for early disease detection and treatment,with a focus on Yin and Yang deficiency constitutions,which serve as key references for disease prevention and management.METHODS:The dataset containing the data of Yin and Yang deficiency constitution was identified through the Gene Expression Omnibus database.This database was used for differential expression genes(DEGs)analysis and weighted gene co-expression network analysis(WGCNA),and the characteristic genes were then obtained in the dataset using a machine learning method.The hub genes of Yin and Yang deficiency constitution were obtained after analysis using the above three methods,and the hub genes were enriched and analyzed.Subsequently,the hub genes of Yin and Yang deficiency constitution were validated using external datasets.Receiver operating characteristic(ROC)analysis was used on each hub genes of the two groups to further understand their diagnostic performance.The mi RNA–lnc RNA-gene network was used to further analyze the hub genes.Immunoinfiltration and gene set enrichment analysis were performed on the shared hub genes.RESULTS:The GSE87474 dataset was used for DEGs analysis and WGCNA.Using machine learning analyses,we identified 15 and 14 hub genes for Yin and Yang deficiency constitutions,respectively.The results of enrichment analyses showed that Yin deficiency constitution was associated with interleukin-17 signaling pathway,whereas Yang deficiency constitution was associated with glycosaminoglycan biosynthesis–keratan sulfate.The validation dataset GSE56116 showed statistically significant data for s-adenosylmethionine sensor upstream of MTORC1(SAMTOR,also named C7orf60),cofilin 2(CFL2),cytohesin 1 interacting protein(CYTIP),G protein-coupled receptor 183(GPR183),hippocampus abundant transcript 1(HIAT1),kelch like family member 15(KLHL15),mitogen-activated protein kinase 6(MAPK6),and prostaglandin-endoperoxide synthase 2(PTGS2)in Yin deficiency and fucosyltransferase 8(FUT8),TATA-box binding protein associated factor,RNA polymerase I subunit D(TAF1D),zinc finger protein 24(ZNF24),MAPK6,and leptin receptor overlapping transcript like 1(LEPROTL1)in Yang deficiency.The ROC results indicated that these genes have diagnostic value.MAPK6 is a shared hub gene for Yin and Yang deficiencies.CONCLUSIONS:This study identified C7orf60,CFL2,CYTIP,GPR183,HIAT1,KLHL15,MAPK6,and PTGS2 in Yin deficiency and FUT8,TAF1D,ZNF24,MAPK6,and LEPROTL1 in Yang deficiency as potential biomarkers,providing insights into their pathogenesis.This theory not only guides the diagnostic approach in TCM but also extends its influence to various scientific research fields.展开更多
As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivat...As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;展开更多
Recombinant adeno-associated virus （rAAV） serotype 2, 3 and 8 vectors are the most promising liver- tropic AAV serotype vectors. Liver diseases are significant problems in China. However, to date, few studies on AAV...Recombinant adeno-associated virus （rAAV） serotype 2, 3 and 8 vectors are the most promising liver- tropic AAV serotype vectors. Liver diseases are significant problems in China. However, to date, few studies on AAV neutralizing antibodies （Nabs） were working with the Chinese population or with the rAAV3 vectors. The present study aimed to determine the prevalence of Nabs in Chinese population against wild-type AAV2, AAV3 and AAV8 capsids as well as additional two AAV3 variants. In addition, we performed a preliminary analysis to investigate the potential influence of traditional Chinese medicine body constitutions on AAV Nabs. Our work demonstrated that the majority of healthy Chinese subjects were positive for AAV Nabs, with the order of AAV2 〉 AAV3 = AAVLK03 〉 AAV8. There was no difference between： 1）AAV3 and its variants; 2） male and female subjects; and 3） different age cohorts （〈 35, 36- 50, and 〉 51 years old）. People in the Qi-deficiency constitution had significantly increased AAV8 Nabs than people in the Gentleness constitution. Our studies may have impact on the future clinical design of AAV-based gene therapy in the Chinese population.展开更多
Objective:To investigate whether the specific traditional Chinese medicine(TCM)constitution of individuals can be defined by certain biological indexes instead of answering the questionnaire,and to explore the possibi...Objective:To investigate whether the specific traditional Chinese medicine(TCM)constitution of individuals can be defined by certain biological indexes instead of answering the questionnaire,and to explore the possibility of discriminating nine TCM constitutions from each other simultaneously using biological indexes.Methods:Blood and urine samples from 152 individuals with nine TCM constitutions were collected,and the related biological indexes were analyzed combining ANOVA,multiple comparison,discriminant analysis,and support vector machine.Results:We found that 4 out of 24 blood routine indexes,7 out of 10 urine routine indexes,and 12 out of 32 biochemical indexes showed differences among the constitutions.High-sensitivity C-reactive protein,apolipoprotein A1,and alkaline phosphatase were potential candidates for screening out individuals with unbalanced constitutions.Combining uric acid,high-density lipoprotein,apolipoprotein A1,creatine kinase,total protein,aspartate aminotransferase,total bile acid,dehydrogenase,sodium,and calcium levels had the potential to directly distinguish the nine TCM constitutions from each other.Among these indexes,the highest ratio of discriminant analysis between two constitutions was 95.5%,while the lowest was 66.1%.Conclusion:Our results suggest that some biochemical and urine indexes are related to various TCM constitutions,and thus they have the potential to be used for TCM constitution classification.展开更多
Based on the theory of constitution of Traditional Chinese Medicine （TCM）, the human population is divided into nine constitutions including one balanced constitution （Normality） and eight unbalanced constitutions...Based on the theory of constitution of Traditional Chinese Medicine （TCM）, the human population is divided into nine constitutions including one balanced constitution （Normality） and eight unbalanced constitutions （Yang-deficiency, Yin-deficiency, Phlegm-wetness, Qi-deficiency, Wetness-heat, Blood stasis, Depressed constitution, and Inherited special constitution）. Different constitutions have specific metabolic features and different susceptibility to certain diseases. However, whether a genetic basis accounts for such constitution classification is yet to be determined. Here we performed a genetic study to assess the association between genetic variations of metabolic genes including PPARD, PPARG and APM1 and the constitutions. A total of 233 individuals of the Han population in China were classified into four groups, Normality, Yang-deficiency, Yin-deficiency and Phlegm-wetness with whom 23 single nucleotide polymorphisms （SNPs） in the three genes were genotyped using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method. Biased distribution of PPARD rs2267669 and rs2076167, APM1 rs7627128 and rs1063539 in Yang-deficiency, PPARG Prol2Ala in Yin-deficiency and PPARD rs2076167, APMI rs266729 and rs7627128 in Phlegm-wetness were observed. The frequencies of Haplotypel3 （Hapl3） of PPARG in Yin-deficiency, Hap25 of APM1 in Yang-deficiency and Hap2 of PPARD and Hapl4 of PPARG in Phlegm-wetness, were significantly different from those in Normality, suggesting those might be group-associated haplotypes. These results suggested that single SNP and haplotypes ofPPARD, PPARG and APM1 may underlie the genetic basis of the constitutions classified in TCM.展开更多
Objective:To explore the structural and functional characteristics of the fecal-associated microbiome(FAM)in a traditional Chinese medicine(TCM)qi-deficiency constitution(QDC)by comparing with balanced constitution(BC...Objective:To explore the structural and functional characteristics of the fecal-associated microbiome(FAM)in a traditional Chinese medicine(TCM)qi-deficiency constitution(QDC)by comparing with balanced constitution(BC)and screen the related biomarkers.Methods:In this cross-sectional study,the TCM constitutions of subjects were determined based on published the Classification and Determination of constitution in TCM and further confirmed by a TCM clinician.Clinical characteristics were recorded,and fecal samples were collected for 16S rDNA sequencing using the Illumina Miseq platform.The FAM structure was described using alpha-diversity indexes,beta-diversity indexes,and the relative abundances of the dominant taxa.Differences in the FAM distribution and function were analyzed with a Wilcoxon rank-sum test,MetagenomeSeq,and LEfSe analysis,after which a receiver operating characteristic curve based on the specific operational taxonomic units(OTUs)was constructed to calculate the area under the curve.Results:Our study population was composed of 22 BCs and 9 QDCs.There were no significant differences between the two groups in the distribution of clinical characteristics or alpha-diversity indexes,except for the sweets preference and blood glucose level.In principal coordinate analysis and partial least squares discriminant analysis,the bacterial communities in the BC group samples and QDC group samples clustered separately.Notably,there were 214 OTUs significantly distributed between groups in the MetagenomeSeq analysis,200 OTUs identified by the Wilcoxon rank-sum test,and 6 OTUs found by the LEfSe analysis.Predicted function analysis revealed that six metabolic pathways were distinctly distributed between the two groups.The area under the curve for the receiver operating characteristic curve based on the four specific OTUs was 0.88.Conclusion:Unique FAM structural and related functional characteristics are displayed in individuals with a QDC,and four specific OTUs could be used as QDC biomarkers to assist in clinical diagnosis.展开更多
OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sam...OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sample of 8448subjects from nine provinces and municipalities was chosen from the database of the TCM constitution and health status survey.Constituent ratio and correspondence analysis were used to find the relationship between smoking and drinking and TCM constitution.RESULTS:There was an association between smokinganddrinkingandtheGentleness,phlegm-dampness,and dampness-heat type constitutions.People that did not smoke tobacco or drink alcohol tended to have Yang-deficiency,Yin-deficiency,Qi-depression,Qi-deficiency,special diathesis,orblood-stasis type constitutions.CONCLUSION:There was a significant correlation between tobacco and alcohol use and TCM constitutions.To improve patient health,more attention should be paid to tobacco and alcohol control.展开更多
Objective:To evaluate the correlation between the body constitution types of Tibetan medicine and traditional Chinese medicine (TCM).Methods:The cluster sampling method was employed to recruit participants from a univ...Objective:To evaluate the correlation between the body constitution types of Tibetan medicine and traditional Chinese medicine (TCM).Methods:The cluster sampling method was employed to recruit participants from a university in the Tibet Autonomous Region.Tibetan medicine and TCM questionnaires were respectively used to assess the participants' constitution information.Descriptive statistics were applied to analyze the baseline and constitution characteristics of the participants.Two-factor correlation analysis and the paired chi-square test were applied to analyze the correlation between Tibetan and TCM constitution types.Results:Data from 466 Tibetan students were analyzed.The mean scores of the rlung,mkhris pa,and bad kan constitution types in Tibetan medicine were 43.2 (11.1),42.1 (10.1),and 45.0 (8.0),respectively;participants with the three-factor convergence body constitution type accounted for 13.7% of the whole population.Among the TCM constitution types,qi stagnation was the most common (21.5%),followed by the balance type (16.5%);the other constitutions detected were qi deficiency,yin deficiency,and yang deficiency.The rate of consistency for the identification of the three-factor convergence constitution in Tibetan medicine and the balance constitution in TCM was 89.1%,with a Kappa coefficient of 0.57 (P >.05).The rlung constitution in Tibetan medicine was associated with the yin deficiency,yang deficiency,and blood stasis constitutions in TCM.The mkhhris pa constitution in Tibetan medicine was associated with the damp heat and yin deficiency constitutions in TCM.The bad kan constitution in Tibetan medicine was associated with the phlegm dampness,qi deficiency,and yin deficiency constitutions in TCM.Conclusion:There is a correlation between the body constitution types of Tibetan medicine and TCM.The reliability and validity of the Questionnaire for TibetanMedicine Constitution requires improvement,and more studies with larger sample sizes and more varied populations are warranted to verify the correlation between Tibetan medicine and TCM constitutions.展开更多
Objective To establish correlation models between various physical examination indexes and traditional Chinese medicine(TCM)constitutions,and explore their relationships based on the radial basis function(RBF)neural n...Objective To establish correlation models between various physical examination indexes and traditional Chinese medicine(TCM)constitutions,and explore their relationships based on the radial basis function(RBF)neural network.Methods The raw data of physical examination indexes and TMC constitutions of 650 subjects who underwent a physical examination were cleaned,classified and sorted,on the basis of which valid data were retrieved and categorized into a training dataset and a test dataset.Subsequently,the RBF neural network was applied to the valid samples in the training set to establish correlation models between various physical examination indexes and TCM constitutions.The accuracy and the error margin of the correlation model were then verified using the valid samples in the test set.Results Of all selected samples,the highest accuracy rates were 80% for the blood lipid index-TCM constitution model;100% for the renal function index-TCM constitution model;100% for the blood routine(male)index-TCM constitution model;88.8% for the blood routine(female)index-TCM constitution model;84.1%for the urine routine index-TCM constitution model;and 100% for the blood transfusion index-TCM constitution model.Conclusions The samples selected in this study suggested that there is a strong correlation between physical examination indexes and TCM constitutions,making it feasible to apply the established correlation models to TCM constitution identification.展开更多
This article will illustrate the constitution as a result of bargaining and negotiation among the elites to allocatepower and mitigate tension among them. Combining the elite’s concept and its nature of a continuous ...This article will illustrate the constitution as a result of bargaining and negotiation among the elites to allocatepower and mitigate tension among them. Combining the elite’s concept and its nature of a continuous struggle forpower with the approach that investigates the constitution as a contract among the powerful ruling class, this articlewill reveal how power is allocated among the elites. As a result, this article provides a fundamental notion of theapproach called “elite-constructed constitution”. This approach delivers the instrument to investigate theconstitutional making process as a negotiation mechanism among the elites, which reflects into constitutionalprovision. Therefore, because this type of constitution has been constructed under the contract’s notion,constitutional endurance is unexpected because this type of constitution requires a high level of trust among thecontract parties. This is in contrast to the notion of the elite’s continuous struggle.展开更多
OBJECTIVE:To investigated the characteristics of patients with functional dyspepsia(FD)in terms of Sasang constitutional medicine.METHODS:A total of 116 patients with FD were recruited based on diagnosis by gastroscop...OBJECTIVE:To investigated the characteristics of patients with functional dyspepsia(FD)in terms of Sasang constitutional medicine.METHODS:A total of 116 patients with FD were recruited based on diagnosis by gastroscopy and symptomatic measurements.The distributions of Sasang constitutions and six syndromes in terms of TKM theory in the patients was compared with those from 1423 healthy subjects.RESULTS:The distribution of Sasang constitutions for the patients with FD significantly differed from that for healthy subjects,especially among women;36.7%vs 45.6%for Taeumin,28.9%vs 33.9%for Soumin,and 34.4%vs 20.4%for Soyangin.Our results assumed a high prevalence in Soyangin women(around 1.7 folds),and Soumin(45.2%),inparticular,had a high prevalence of"deficiency and coldness of spleen and stomach"compared with Taeumin(14.9%)and Soyangin types(15.7%).CONCLUSION:This study identified a trend for the frequency of FD and the Sasang constitutions.The findings may provide new ideas for the study of prevention and management of FD.展开更多
The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is great...The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions,indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone.Following the rheological tests,the number of small pores in the sandstone decreased,while the number of medium-sized pores increased,forming new seepage channels.The high initial rheological stress accelerated fracture compression and the closure of seepage channels,resulting in reduction in the permeability of sandstone.Based on the principles of generalized rheology and the experimental findings,a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed.Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model,which confirmed the applicability of the generalized rheological numerical simulation method.These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock.展开更多
Investigating the combined effects of mining damage and creep damage on slope stability is crucial,as it can comprehensively reveal the non-linear deformation characteristics of rock under their joint influence.This s...Investigating the combined effects of mining damage and creep damage on slope stability is crucial,as it can comprehensively reveal the non-linear deformation characteristics of rock under their joint influence.This study develops a fractional-order nonlinear creep constitutive model that incorporates the double damage effect and implements a non-linear creep subroutine for soft rock using the threedimensional finite difference method on the FLAC3D platform.Comparative analysis of the theoretical,numerical,and experimental results reveals that the fractional-order constitutive model,which incorporates the double damage effect,accurately reflects the distinct deformation stages of green mudstone during creep failure and effectively captures the non-linear deformation in the accelerated creep phase.The numerical results show a fitting accuracy exceeding 97%with the creep test curves,significantly outperforming the 61%accuracy of traditional creep models.展开更多
The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conduct...The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conducts a uniaxial graded loading creep test on yellow sandstone under different pre-peak unloading and wetting-drying cycles. The improved nonlinear Nishihara model was obtained by introducing a nonlinear viscous element with an accelerated creep threshold switch. The sensitivity characteristics of the parameters of the improved creep model were analyzed and a nonlinear creep constitutive model was established, considering the unloading-cyclic intrinsic damage induced by water intrusion. The research results show that:(1)With an increase in the unloading point, the porosity of the rock samples initially decreases and then increases. As the number of cyclic water intrusions rises, the porosity of the rock samples gradually increases, reaching a maximum of 9.58% at an unloading point of 70% uniaxial compression stress(0.7 Rc) after five cycles.(2) Total creep deformation increases with the number of cyclic water intrusions;however, with an increase in the unloading ratio, the original samples show an initial decrease, followed by an increase in creep deformation. With a higher unloading ratio and various instances of cyclic water intrusion, the total creep time of the rock samples,compared to the original samples, is reduced by 21.8%and 23.02%. The creep damage mode gradually changes from shear damage to tensile damage.(3) The sensitivity characteristics of the improved creep model parameters show that transient elasticity modulus E1 is affected by the coupling of unloading and cyclic water intrusion. The viscoelastic modulus E2 and viscous coefficient η1 are mainly affected by unloading and cyclic water intrusion.(4) Based on the strain equivalence principle of damage mechanics, the damage treatment of the parameters in the original model is improved to construct a nonlinear creep constitutive model that considers unloading-cyclic water intrusion damage. A parameter inversion and comparison to the traditional Nishihara model reveal an average relative standard deviation of 0.271%,significantly less than 1%, indicating a more accurate nonlinear creep constitutive model. The research results are crucial for analyzing the long-term stability of water-related steep rocky slopes post-excavation and unloading and for preventing and controlling creep-type landslide disasters.展开更多
The undrained mechanical behavior of unsaturated completely weathered granite(CWG)is highly susceptible to alterations in the hydraulic environment,particularly under uniaxial loading conditions,due to the unique natu...The undrained mechanical behavior of unsaturated completely weathered granite(CWG)is highly susceptible to alterations in the hydraulic environment,particularly under uniaxial loading conditions,due to the unique nature of this soil type.In this study,a series of unconfined compression tests were carried out on unsaturated CWG soil in an underground engineering site,and the effects of varying the environmental variables on the main undrained mechanical properties were analyzed.Based on the experimental results,a novel constitutive model was then established using the damage mechanics theory and the undetermined coefficient method.The results demonstrate that the curves of remolded CWG specimens with different moisture contents and dry densities exhibited diverse characteristics,including brittleness,significant softening,and ductility.As a typical indicator,the unconfined compression strength of soil specimens initially increased with an increase in moisture content and then decreased.Meanwhile,an optimal moisture content of approximately 10.5%could be observed,while a critical moisture content value of 13.0%was identified,beyond which the strength of the specimen decreases sharply.Moreover,the deformation and fracture of CWG specimens were predominantly caused by shear failure,and the ultimate failure modes were primarily influenced by moisture content rather than dry density.Furthermore,by comparing several similar models and the experimental data,the proposed model could accurately replicate the undrained mechanical characteristics of unsaturated CWG soil,and quantitatively describe the key mechanical indexes.These findings offer a valuable reference point for understanding the underlying mechanisms,anticipating potential risks,and implementing effective control measures in similar underground engineering projects.展开更多
Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature ...Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature treatment were conducted with a ϕ75 mm split Hopkinson tension bar (SHTB) to investigate the mesoscopic fracture and damage properties of rock. An improved scanning electron microscopy (SEM) experimental method was used to analyze the tensile fracture surfaces of rock samples. Qualitative and quantitative analyses were performed to assess evolution of mesoscopic damage of heat-damaged rock under tensile loading. A constitutive model describing the mesoscopic fractal damage under thermo-mechanical coupling was established. The results showed that the high temperatures significantly reduced the tensile strength and fracture surface roughness of the red sandstone. The three-dimensional (3D) reconstruction of the fracture surface of the samples that experienced tensile failure at 900 °C showed a flat surface. The standard deviation of elevation and slope angle of specimen fracture surface first increased and then decreased with increasing temperature. The threshold for brittle fracture of the heat-damaged red sandstone specimens was 600 °C. Beyond this threshold temperature, local ductile fracture occurred, resulting in plastic deformation of the fracture surface during tensile fracturing. With increase of temperature, the internal meso-structure of samples was strengthened slightly at first and then deteriorated gradually, which was consistent with the change of macroscopic mechanical properties of red sandstone. The mesoscopic characteristics, such as the number, mean side length, maximum area, porosity, and fractal dimension of crack, exhibited an initial decline, followed by a gradual increase. The development of microcracks in samples had significant influence on mesoscopic fractal dimension. The mesoscopic fractal characteristics were used to establish a mesoscopic fractal damage constitutive model for red sandstone, and the agreement between the theoretical and experimental results validated the proposed model.展开更多
In this work,fow behavior and dynamic recrystallization(DRX)mechanism of a low carbon martensitic stainless bearing steel,CSS-42L,were investigated using a thermomechanical simulator under the temperature and strain r...In this work,fow behavior and dynamic recrystallization(DRX)mechanism of a low carbon martensitic stainless bearing steel,CSS-42L,were investigated using a thermomechanical simulator under the temperature and strain rate ranges of 900 to 1100℃ and 0.1 to 20 s^(−1),respectively.The Arrhenius-type constitutive equation was established based on the fow stress curves.Moreover,the peak stress decreased with the increase in deformation temperature and the decrease in strain rate.There were two DRX mechanisms during hot deformation of the current studied steel,the main one being discontinuous dynamic recrystallization mechanism,acting through grain boundary bulging and migration,and the auxiliary one being continuous dynamic recrystallization mechanism,working through the rotation of sub-grains.On the basis of microstructural characterizations,power dissipation maps and fow instability maps,the optimized hot deformation parameters for CSS-42L bearing steel were determined as 1050℃/0.1 s^(−1) and 1100℃/1 s^(−1).展开更多
基金supported by the Special Clinical Research Project of the Health Industry by the Shanghai Municipal Health Commission(No.202240055)。
文摘Objective:The concept of constitution in traditional Chinese medicine(TCM)has been increasingly recognized as a crucial factor in both the prevention and treatment of insomnia.However,rigorous statistical evidence on the correlation between TCM constitutions—particularly mixed constitutions—and insomnia disorder remains limited.This study aimed to investigate the association between specific TCM constitutions and insomnia disorder.Methods:A cross-sectional study was conducted at the Department of Preventive Medicine,Yueyang Hospital of Integrated Traditional Chinese and Western Medicine,Shanghai,from November 2022 to December 2023.TCM constitutions were assessed using the Constitution in Chinese Medicine Questionnaire.Insomnia disorder was diagnosed by experienced internal medicine physicians according to the criteria of the International Classification of Sleep Disorders,Third Edition.A total of 1065 eligible participants(242 with insomnia disorder and 823 controls)were included in the final analysis.Results:Among the participants,862(80.94%)exhibited biased constitutions,with 75.30%of these having mixed constitutions.Logistic regression analysis revealed a negative association between the gentleness constitution and insomnia disorder,whereas qi-deficiency,yang-deficiency,phlegm-dampness and qidepression constitutions were positively associated with insomnia disorder.These associations remained significant after adjusting for potential confounders and were further validated through sensitivity analysis using propensity score matching.Conclusion:Significant associations between TCM constitutions and insomnia disorder were demonstrated.Future research should further investigate these relationships and explore the underlying mechanisms through rigorous longitudinal and interventional studies to improve understanding and clinical applications.
基金Supported by National Natural Science Foundation of China:Establishment and Validation of a High-throughput Screening System for Traditional Chinese Medicine Against Dry Eye Disease based on transforming growth factor-βand B-cell lymphoma-2(No.81574031)2023 Hunan Provincial Department of Education Scientific Research Project:Yiguanjian Decoction Regulates Th17/Treg Cell Balance and Its Intervention Mechanism in Dry Eye with Liver Yin Deficiency Syndrome(No.23A0300)。
文摘OBJECTIVE:To utilize the Traditional Chinese Medicine constitution(TCMC)as a complementary and alternative approach for early disease detection and treatment,with a focus on Yin and Yang deficiency constitutions,which serve as key references for disease prevention and management.METHODS:The dataset containing the data of Yin and Yang deficiency constitution was identified through the Gene Expression Omnibus database.This database was used for differential expression genes(DEGs)analysis and weighted gene co-expression network analysis(WGCNA),and the characteristic genes were then obtained in the dataset using a machine learning method.The hub genes of Yin and Yang deficiency constitution were obtained after analysis using the above three methods,and the hub genes were enriched and analyzed.Subsequently,the hub genes of Yin and Yang deficiency constitution were validated using external datasets.Receiver operating characteristic(ROC)analysis was used on each hub genes of the two groups to further understand their diagnostic performance.The mi RNA–lnc RNA-gene network was used to further analyze the hub genes.Immunoinfiltration and gene set enrichment analysis were performed on the shared hub genes.RESULTS:The GSE87474 dataset was used for DEGs analysis and WGCNA.Using machine learning analyses,we identified 15 and 14 hub genes for Yin and Yang deficiency constitutions,respectively.The results of enrichment analyses showed that Yin deficiency constitution was associated with interleukin-17 signaling pathway,whereas Yang deficiency constitution was associated with glycosaminoglycan biosynthesis–keratan sulfate.The validation dataset GSE56116 showed statistically significant data for s-adenosylmethionine sensor upstream of MTORC1(SAMTOR,also named C7orf60),cofilin 2(CFL2),cytohesin 1 interacting protein(CYTIP),G protein-coupled receptor 183(GPR183),hippocampus abundant transcript 1(HIAT1),kelch like family member 15(KLHL15),mitogen-activated protein kinase 6(MAPK6),and prostaglandin-endoperoxide synthase 2(PTGS2)in Yin deficiency and fucosyltransferase 8(FUT8),TATA-box binding protein associated factor,RNA polymerase I subunit D(TAF1D),zinc finger protein 24(ZNF24),MAPK6,and leptin receptor overlapping transcript like 1(LEPROTL1)in Yang deficiency.The ROC results indicated that these genes have diagnostic value.MAPK6 is a shared hub gene for Yin and Yang deficiencies.CONCLUSIONS:This study identified C7orf60,CFL2,CYTIP,GPR183,HIAT1,KLHL15,MAPK6,and PTGS2 in Yin deficiency and FUT8,TAF1D,ZNF24,MAPK6,and LEPROTL1 in Yang deficiency as potential biomarkers,providing insights into their pathogenesis.This theory not only guides the diagnostic approach in TCM but also extends its influence to various scientific research fields.
基金supported by a grant from the National High Technology Research and Development Program("863" Program) of China(No. 2011AA100103)
文摘As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;
文摘Recombinant adeno-associated virus （rAAV） serotype 2, 3 and 8 vectors are the most promising liver- tropic AAV serotype vectors. Liver diseases are significant problems in China. However, to date, few studies on AAV neutralizing antibodies （Nabs） were working with the Chinese population or with the rAAV3 vectors. The present study aimed to determine the prevalence of Nabs in Chinese population against wild-type AAV2, AAV3 and AAV8 capsids as well as additional two AAV3 variants. In addition, we performed a preliminary analysis to investigate the potential influence of traditional Chinese medicine body constitutions on AAV Nabs. Our work demonstrated that the majority of healthy Chinese subjects were positive for AAV Nabs, with the order of AAV2 〉 AAV3 = AAVLK03 〉 AAV8. There was no difference between： 1）AAV3 and its variants; 2） male and female subjects; and 3） different age cohorts （〈 35, 36- 50, and 〉 51 years old）. People in the Qi-deficiency constitution had significantly increased AAV8 Nabs than people in the Gentleness constitution. Our studies may have impact on the future clinical design of AAV-based gene therapy in the Chinese population.
基金supported by the National Key Research and Development Project (2019YFC1710104)the National Natural Science Foundation of China (81430099)+1 种基金the International Cooperation and Exchanges (2014DFA32950)the Fundamental Research Funds for the Central Universities (2020-JYB-XJSJJ-026)
文摘Objective:To investigate whether the specific traditional Chinese medicine(TCM)constitution of individuals can be defined by certain biological indexes instead of answering the questionnaire,and to explore the possibility of discriminating nine TCM constitutions from each other simultaneously using biological indexes.Methods:Blood and urine samples from 152 individuals with nine TCM constitutions were collected,and the related biological indexes were analyzed combining ANOVA,multiple comparison,discriminant analysis,and support vector machine.Results:We found that 4 out of 24 blood routine indexes,7 out of 10 urine routine indexes,and 12 out of 32 biochemical indexes showed differences among the constitutions.High-sensitivity C-reactive protein,apolipoprotein A1,and alkaline phosphatase were potential candidates for screening out individuals with unbalanced constitutions.Combining uric acid,high-density lipoprotein,apolipoprotein A1,creatine kinase,total protein,aspartate aminotransferase,total bile acid,dehydrogenase,sodium,and calcium levels had the potential to directly distinguish the nine TCM constitutions from each other.Among these indexes,the highest ratio of discriminant analysis between two constitutions was 95.5%,while the lowest was 66.1%.Conclusion:Our results suggest that some biochemical and urine indexes are related to various TCM constitutions,and thus they have the potential to be used for TCM constitution classification.
基金supported by the National Basic Research Program of China (973 Program) (No. 2005CB523501)
文摘Based on the theory of constitution of Traditional Chinese Medicine （TCM）, the human population is divided into nine constitutions including one balanced constitution （Normality） and eight unbalanced constitutions （Yang-deficiency, Yin-deficiency, Phlegm-wetness, Qi-deficiency, Wetness-heat, Blood stasis, Depressed constitution, and Inherited special constitution）. Different constitutions have specific metabolic features and different susceptibility to certain diseases. However, whether a genetic basis accounts for such constitution classification is yet to be determined. Here we performed a genetic study to assess the association between genetic variations of metabolic genes including PPARD, PPARG and APM1 and the constitutions. A total of 233 individuals of the Han population in China were classified into four groups, Normality, Yang-deficiency, Yin-deficiency and Phlegm-wetness with whom 23 single nucleotide polymorphisms （SNPs） in the three genes were genotyped using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） method. Biased distribution of PPARD rs2267669 and rs2076167, APM1 rs7627128 and rs1063539 in Yang-deficiency, PPARG Prol2Ala in Yin-deficiency and PPARD rs2076167, APMI rs266729 and rs7627128 in Phlegm-wetness were observed. The frequencies of Haplotypel3 （Hapl3） of PPARG in Yin-deficiency, Hap25 of APM1 in Yang-deficiency and Hap2 of PPARD and Hapl4 of PPARG in Phlegm-wetness, were significantly different from those in Normality, suggesting those might be group-associated haplotypes. These results suggested that single SNP and haplotypes ofPPARD, PPARG and APM1 may underlie the genetic basis of the constitutions classified in TCM.
基金the National Natural Science Foundation of China(81430099 and 31500704)International Science&Technology Cooperation Program of China(2014DFA32950)Research program from Beijing University of Chinese Medicine(1000041510049,BUCM-2019-JCRC006 and 2019-JYB-TD013).
文摘Objective:To explore the structural and functional characteristics of the fecal-associated microbiome(FAM)in a traditional Chinese medicine(TCM)qi-deficiency constitution(QDC)by comparing with balanced constitution(BC)and screen the related biomarkers.Methods:In this cross-sectional study,the TCM constitutions of subjects were determined based on published the Classification and Determination of constitution in TCM and further confirmed by a TCM clinician.Clinical characteristics were recorded,and fecal samples were collected for 16S rDNA sequencing using the Illumina Miseq platform.The FAM structure was described using alpha-diversity indexes,beta-diversity indexes,and the relative abundances of the dominant taxa.Differences in the FAM distribution and function were analyzed with a Wilcoxon rank-sum test,MetagenomeSeq,and LEfSe analysis,after which a receiver operating characteristic curve based on the specific operational taxonomic units(OTUs)was constructed to calculate the area under the curve.Results:Our study population was composed of 22 BCs and 9 QDCs.There were no significant differences between the two groups in the distribution of clinical characteristics or alpha-diversity indexes,except for the sweets preference and blood glucose level.In principal coordinate analysis and partial least squares discriminant analysis,the bacterial communities in the BC group samples and QDC group samples clustered separately.Notably,there were 214 OTUs significantly distributed between groups in the MetagenomeSeq analysis,200 OTUs identified by the Wilcoxon rank-sum test,and 6 OTUs found by the LEfSe analysis.Predicted function analysis revealed that six metabolic pathways were distinctly distributed between the two groups.The area under the curve for the receiver operating characteristic curve based on the four specific OTUs was 0.88.Conclusion:Unique FAM structural and related functional characteristics are displayed in individuals with a QDC,and four specific OTUs could be used as QDC biomarkers to assist in clinical diagnosis.
基金Supported by a Grant from the Major State Basic Research Development Program of China(973 Program)(No.2011CB505403)
文摘OBJECTIVE:To investigate the relationship between smoking and drinking and constitution types from Traditional Chinese Medicine(TCM)theory.METHODS:The Constitution in Chinese Medicine Questionnaire(CCMQ)was used.A sample of 8448subjects from nine provinces and municipalities was chosen from the database of the TCM constitution and health status survey.Constituent ratio and correspondence analysis were used to find the relationship between smoking and drinking and TCM constitution.RESULTS:There was an association between smokinganddrinkingandtheGentleness,phlegm-dampness,and dampness-heat type constitutions.People that did not smoke tobacco or drink alcohol tended to have Yang-deficiency,Yin-deficiency,Qi-depression,Qi-deficiency,special diathesis,orblood-stasis type constitutions.CONCLUSION:There was a significant correlation between tobacco and alcohol use and TCM constitutions.To improve patient health,more attention should be paid to tobacco and alcohol control.
基金This study was supported by the National Natural Science Foundation of China(81704197)the Fundamental Research Funds for the Central Universities(2017-JYB-XS-012).
文摘Objective:To evaluate the correlation between the body constitution types of Tibetan medicine and traditional Chinese medicine (TCM).Methods:The cluster sampling method was employed to recruit participants from a university in the Tibet Autonomous Region.Tibetan medicine and TCM questionnaires were respectively used to assess the participants' constitution information.Descriptive statistics were applied to analyze the baseline and constitution characteristics of the participants.Two-factor correlation analysis and the paired chi-square test were applied to analyze the correlation between Tibetan and TCM constitution types.Results:Data from 466 Tibetan students were analyzed.The mean scores of the rlung,mkhris pa,and bad kan constitution types in Tibetan medicine were 43.2 (11.1),42.1 (10.1),and 45.0 (8.0),respectively;participants with the three-factor convergence body constitution type accounted for 13.7% of the whole population.Among the TCM constitution types,qi stagnation was the most common (21.5%),followed by the balance type (16.5%);the other constitutions detected were qi deficiency,yin deficiency,and yang deficiency.The rate of consistency for the identification of the three-factor convergence constitution in Tibetan medicine and the balance constitution in TCM was 89.1%,with a Kappa coefficient of 0.57 (P >.05).The rlung constitution in Tibetan medicine was associated with the yin deficiency,yang deficiency,and blood stasis constitutions in TCM.The mkhhris pa constitution in Tibetan medicine was associated with the damp heat and yin deficiency constitutions in TCM.The bad kan constitution in Tibetan medicine was associated with the phlegm dampness,qi deficiency,and yin deficiency constitutions in TCM.Conclusion:There is a correlation between the body constitution types of Tibetan medicine and TCM.The reliability and validity of the Questionnaire for TibetanMedicine Constitution requires improvement,and more studies with larger sample sizes and more varied populations are warranted to verify the correlation between Tibetan medicine and TCM constitutions.
基金the funding support from the National Key Research and Development Project of China(No.2018YFC1707606)National Natural Science Foundation of China(No.81904324)Youth Foundation of Sichuan Administration of Traditional Chinese Medicine(No.2016Q065).
文摘Objective To establish correlation models between various physical examination indexes and traditional Chinese medicine(TCM)constitutions,and explore their relationships based on the radial basis function(RBF)neural network.Methods The raw data of physical examination indexes and TMC constitutions of 650 subjects who underwent a physical examination were cleaned,classified and sorted,on the basis of which valid data were retrieved and categorized into a training dataset and a test dataset.Subsequently,the RBF neural network was applied to the valid samples in the training set to establish correlation models between various physical examination indexes and TCM constitutions.The accuracy and the error margin of the correlation model were then verified using the valid samples in the test set.Results Of all selected samples,the highest accuracy rates were 80% for the blood lipid index-TCM constitution model;100% for the renal function index-TCM constitution model;100% for the blood routine(male)index-TCM constitution model;88.8% for the blood routine(female)index-TCM constitution model;84.1%for the urine routine index-TCM constitution model;and 100% for the blood transfusion index-TCM constitution model.Conclusions The samples selected in this study suggested that there is a strong correlation between physical examination indexes and TCM constitutions,making it feasible to apply the established correlation models to TCM constitution identification.
文摘This article will illustrate the constitution as a result of bargaining and negotiation among the elites to allocatepower and mitigate tension among them. Combining the elite’s concept and its nature of a continuous struggle forpower with the approach that investigates the constitution as a contract among the powerful ruling class, this articlewill reveal how power is allocated among the elites. As a result, this article provides a fundamental notion of theapproach called “elite-constructed constitution”. This approach delivers the instrument to investigate theconstitutional making process as a negotiation mechanism among the elites, which reflects into constitutionalprovision. Therefore, because this type of constitution has been constructed under the contract’s notion,constitutional endurance is unexpected because this type of constitution requires a high level of trust among thecontract parties. This is in contrast to the notion of the elite’s continuous struggle.
基金Supported by the a National Research Foundation of Korea(NRF)Grant funded by the Ministry of Science,ICT&Future Planning(No.2006-2005173)
文摘OBJECTIVE:To investigated the characteristics of patients with functional dyspepsia(FD)in terms of Sasang constitutional medicine.METHODS:A total of 116 patients with FD were recruited based on diagnosis by gastroscopy and symptomatic measurements.The distributions of Sasang constitutions and six syndromes in terms of TKM theory in the patients was compared with those from 1423 healthy subjects.RESULTS:The distribution of Sasang constitutions for the patients with FD significantly differed from that for healthy subjects,especially among women;36.7%vs 45.6%for Taeumin,28.9%vs 33.9%for Soumin,and 34.4%vs 20.4%for Soyangin.Our results assumed a high prevalence in Soyangin women(around 1.7 folds),and Soumin(45.2%),inparticular,had a high prevalence of"deficiency and coldness of spleen and stomach"compared with Taeumin(14.9%)and Soyangin types(15.7%).CONCLUSION:This study identified a trend for the frequency of FD and the Sasang constitutions.The findings may provide new ideas for the study of prevention and management of FD.
基金supported and financed by Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology (No.2024yjrc96)Anhui Provincial University Excellent Research and Innovation Team Support Project (No.2022AH010053)+2 种基金National Key Research and Development Program of China (Nos.2023YFC2907602 and 2022YFF1303302)Anhui Provincial Major Science and Technology Project (No.202203a07020011)Open Foundation of Joint National-Local Engineering Research Centre for Safe and Precise Coal Mining (No.EC2023020)。
文摘The generalized rheological tests on sandstone were conducted under both dynamic stress and seepage fields.The results demonstrate that the rheological strain of the specimen under increased stress conditions is greater than that under creep conditions,indicating that the dynamic stress field significantly influences the rheological behaviours of sandstone.Following the rheological tests,the number of small pores in the sandstone decreased,while the number of medium-sized pores increased,forming new seepage channels.The high initial rheological stress accelerated fracture compression and the closure of seepage channels,resulting in reduction in the permeability of sandstone.Based on the principles of generalized rheology and the experimental findings,a novel rock rheological constitutive model incorporating both the dynamic stress field and seepage properties has been developed.Numerical simulations of surrounding rock deformation in geotechnical engineering were carried out using a secondary development version of this model,which confirmed the applicability of the generalized rheological numerical simulation method.These results provide theoretical support for the long-term stability evaluation of engineering rock masses and for predicting the deformation of surrounding rock.
基金support from the National Natural Science Foundation of China(No.52308316)the Scientific Research Foundation of Weifang University(Grant No.2024BS42)+2 种基金China Postdoctoral Science Foundation(No.2022M721885)the Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province(No.ZJRMG-2022-01)supported by Open Research Fund of State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences(NO.SKLGME023017).
文摘Investigating the combined effects of mining damage and creep damage on slope stability is crucial,as it can comprehensively reveal the non-linear deformation characteristics of rock under their joint influence.This study develops a fractional-order nonlinear creep constitutive model that incorporates the double damage effect and implements a non-linear creep subroutine for soft rock using the threedimensional finite difference method on the FLAC3D platform.Comparative analysis of the theoretical,numerical,and experimental results reveals that the fractional-order constitutive model,which incorporates the double damage effect,accurately reflects the distinct deformation stages of green mudstone during creep failure and effectively captures the non-linear deformation in the accelerated creep phase.The numerical results show a fitting accuracy exceeding 97%with the creep test curves,significantly outperforming the 61%accuracy of traditional creep models.
基金We gratefully acknowledge the financial support from the Key Laboratory of Geological Safety of Coastal Urban Underground Space,Ministry of Natural Resources(BHKF2022Y03)Shandong Provincial Colleges and Universities Youth Innovation Technology Support Program,Education Department of Shandong Province(grant number 2023KJ092).
文摘The study focuses on the creep characteristics of significant yellow sandstone for water conservancy, hydropower, and other waterrelated slope excavation unloading rock-graded loading creep characteristics. It conducts a uniaxial graded loading creep test on yellow sandstone under different pre-peak unloading and wetting-drying cycles. The improved nonlinear Nishihara model was obtained by introducing a nonlinear viscous element with an accelerated creep threshold switch. The sensitivity characteristics of the parameters of the improved creep model were analyzed and a nonlinear creep constitutive model was established, considering the unloading-cyclic intrinsic damage induced by water intrusion. The research results show that:(1)With an increase in the unloading point, the porosity of the rock samples initially decreases and then increases. As the number of cyclic water intrusions rises, the porosity of the rock samples gradually increases, reaching a maximum of 9.58% at an unloading point of 70% uniaxial compression stress(0.7 Rc) after five cycles.(2) Total creep deformation increases with the number of cyclic water intrusions;however, with an increase in the unloading ratio, the original samples show an initial decrease, followed by an increase in creep deformation. With a higher unloading ratio and various instances of cyclic water intrusion, the total creep time of the rock samples,compared to the original samples, is reduced by 21.8%and 23.02%. The creep damage mode gradually changes from shear damage to tensile damage.(3) The sensitivity characteristics of the improved creep model parameters show that transient elasticity modulus E1 is affected by the coupling of unloading and cyclic water intrusion. The viscoelastic modulus E2 and viscous coefficient η1 are mainly affected by unloading and cyclic water intrusion.(4) Based on the strain equivalence principle of damage mechanics, the damage treatment of the parameters in the original model is improved to construct a nonlinear creep constitutive model that considers unloading-cyclic water intrusion damage. A parameter inversion and comparison to the traditional Nishihara model reveal an average relative standard deviation of 0.271%,significantly less than 1%, indicating a more accurate nonlinear creep constitutive model. The research results are crucial for analyzing the long-term stability of water-related steep rocky slopes post-excavation and unloading and for preventing and controlling creep-type landslide disasters.
基金Project(42202318)supported by the National Natural Science Foundation of ChinaProject(252300421199)supported by the Natural Science Foundation of Henan Province,ChinaProject(2024JJ6219)supported by the Hunan Provincial Natural Science Foundation of China。
文摘The undrained mechanical behavior of unsaturated completely weathered granite(CWG)is highly susceptible to alterations in the hydraulic environment,particularly under uniaxial loading conditions,due to the unique nature of this soil type.In this study,a series of unconfined compression tests were carried out on unsaturated CWG soil in an underground engineering site,and the effects of varying the environmental variables on the main undrained mechanical properties were analyzed.Based on the experimental results,a novel constitutive model was then established using the damage mechanics theory and the undetermined coefficient method.The results demonstrate that the curves of remolded CWG specimens with different moisture contents and dry densities exhibited diverse characteristics,including brittleness,significant softening,and ductility.As a typical indicator,the unconfined compression strength of soil specimens initially increased with an increase in moisture content and then decreased.Meanwhile,an optimal moisture content of approximately 10.5%could be observed,while a critical moisture content value of 13.0%was identified,beyond which the strength of the specimen decreases sharply.Moreover,the deformation and fracture of CWG specimens were predominantly caused by shear failure,and the ultimate failure modes were primarily influenced by moisture content rather than dry density.Furthermore,by comparing several similar models and the experimental data,the proposed model could accurately replicate the undrained mechanical characteristics of unsaturated CWG soil,and quantitatively describe the key mechanical indexes.These findings offer a valuable reference point for understanding the underlying mechanisms,anticipating potential risks,and implementing effective control measures in similar underground engineering projects.
基金supported by The National Natural Science Foundation of China(Grant Nos.12272411 and 42007259).
文摘Understanding the mesoscopic tensile fracture damage of rock is the basis of evaluating the deterioration process of mechanical properties of heat-damaged rock. For this, tensile tests of rocks under high-temperature treatment were conducted with a ϕ75 mm split Hopkinson tension bar (SHTB) to investigate the mesoscopic fracture and damage properties of rock. An improved scanning electron microscopy (SEM) experimental method was used to analyze the tensile fracture surfaces of rock samples. Qualitative and quantitative analyses were performed to assess evolution of mesoscopic damage of heat-damaged rock under tensile loading. A constitutive model describing the mesoscopic fractal damage under thermo-mechanical coupling was established. The results showed that the high temperatures significantly reduced the tensile strength and fracture surface roughness of the red sandstone. The three-dimensional (3D) reconstruction of the fracture surface of the samples that experienced tensile failure at 900 °C showed a flat surface. The standard deviation of elevation and slope angle of specimen fracture surface first increased and then decreased with increasing temperature. The threshold for brittle fracture of the heat-damaged red sandstone specimens was 600 °C. Beyond this threshold temperature, local ductile fracture occurred, resulting in plastic deformation of the fracture surface during tensile fracturing. With increase of temperature, the internal meso-structure of samples was strengthened slightly at first and then deteriorated gradually, which was consistent with the change of macroscopic mechanical properties of red sandstone. The mesoscopic characteristics, such as the number, mean side length, maximum area, porosity, and fractal dimension of crack, exhibited an initial decline, followed by a gradual increase. The development of microcracks in samples had significant influence on mesoscopic fractal dimension. The mesoscopic fractal characteristics were used to establish a mesoscopic fractal damage constitutive model for red sandstone, and the agreement between the theoretical and experimental results validated the proposed model.
基金fnancially supported by the Scientifc Research Project of the Department of Education in Hunan Prov ince,China(Grant No.23B0533).
文摘In this work,fow behavior and dynamic recrystallization(DRX)mechanism of a low carbon martensitic stainless bearing steel,CSS-42L,were investigated using a thermomechanical simulator under the temperature and strain rate ranges of 900 to 1100℃ and 0.1 to 20 s^(−1),respectively.The Arrhenius-type constitutive equation was established based on the fow stress curves.Moreover,the peak stress decreased with the increase in deformation temperature and the decrease in strain rate.There were two DRX mechanisms during hot deformation of the current studied steel,the main one being discontinuous dynamic recrystallization mechanism,acting through grain boundary bulging and migration,and the auxiliary one being continuous dynamic recrystallization mechanism,working through the rotation of sub-grains.On the basis of microstructural characterizations,power dissipation maps and fow instability maps,the optimized hot deformation parameters for CSS-42L bearing steel were determined as 1050℃/0.1 s^(−1) and 1100℃/1 s^(−1).
