The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of trans...The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s).展开更多
AIM: To investigate coping mechanisms, constipation symptoms and anorectal physiology in 80 constipated subjects and 18 controls.METHODS: Constipation was diagnosed by Rome Ⅱ criteria.Coping ability and anxiety/depre...AIM: To investigate coping mechanisms, constipation symptoms and anorectal physiology in 80 constipated subjects and 18 controls.METHODS: Constipation was diagnosed by Rome Ⅱ criteria.Coping ability and anxiety/depression were assessed by validated questionnaires. Transit time and balloon distension test were performed.RESULTS: 34.5% patients were classified as slow transit type of constipation. The total colonic transit time (56 h vs 10 h, P＜0.0001) and rectal sensation including urge sensation (79 mL vs 63 mL, P = 0.019) and maximum tolerable volume (110 mL vs95 mL, P = 0.03) differed in patients and controls. Constipated subjects had significantly higher anxiety and depression scores and lower SF-36 scores in all categories. They also demonstrated higher scores of'monitoring' coping strategy (14+6 vs9+3, P = 0.001),which correlated with the rectal distension sensation (P = 0.005), urge sensation (P=0.002), and maximum tolerable volume (P = 0.035). The less use of blunting strategy predicted slow transit constipation in both univariate (P = 0.01) and multivariate analysis (P = 0.03).CONCLUSION: Defective or ineffective use of coping strategies may be an important etiology in functional constipation and subsequently reflected in abnormal anorectal physiology.展开更多
Major and profound changes have taken place in China over the past 30 years. Rapid socioeconomic progress has exerted a great impact on lifestyle, ranging from food, clothing, working and living conditions, and means ...Major and profound changes have taken place in China over the past 30 years. Rapid socioeconomic progress has exerted a great impact on lifestyle, ranging from food, clothing, working and living conditions, and means of transportation to leisure activities and entertainment. At the same time, new health problems have emerged, and health services are facing new challenges. Presently, cardiovascular diseases （CVD） are among the top health problems of the Chinese people, and pose a serious challenge to all engaged in the prevention and control of these diseases. An epidemic of CVD in China is emerging as a result of lifestyle changes, urbanization and longevity. Both national policy decision-making and medical practice urgently need an authoritative report which comprehensively reflects the trends in the epidemic of CVD and current preventive measures. Since 2005, guided by the Bureau of Disease Prevention of the Ministry of Health of the People＇s Republic of China and the National Center for Cardiovascular Diseases of China, nationwide experts in the fields of epidemiology, clinical medicine and health economics in the realms of CVD, cerebrovascular disease, diabetes and chronic kidney disease, completed the Report on Cardiovascular Diseases in China every year. The report aims to provide a timely review of the trend of the epidemic and to assess the progress of prevention and control of CVD. In addition, as the report is authoritative, representative and readable, it will become an information platform in the CVD field and an important reference book for government, academic institutes, medical organizations and clinical physicians. This publication is expected to play a positive role in the prevention and control of CVD in China. We present an abstract from the Report on Cardiovascular Diseases in China （2010）, including trends in CVD, morbidity and mortality of major CVDs, up-to-date assessment of risk factors, as well as health resources for CVD, and a profile of medical expenditure, with the aim of p展开更多
Ischemic stroke is a leading cause of morbidity and mortality worldwide. Resident microglia are the principal immune cells of the brain, and the first to respond to the pathophysiological changes induced by ischemic s...Ischemic stroke is a leading cause of morbidity and mortality worldwide. Resident microglia are the principal immune cells of the brain, and the first to respond to the pathophysiological changes induced by ischemic stroke. Traditionally, it has been thought that microglial activation is deleterious in ischemic stroke, and therapies to suppress it have been intensively explored. However,increasing evidence suggests that microglial activation is also critical for neurogenesis, angiogenesis, and synaptic remodeling, thereby promoting functional recovery after cerebral ischemia. Here, we comprehensively review the dual role of microglia during the different phases of ischemic stroke, and the possible mechanisms controlling the post-ischemic activity of microglia. In addition, we discuss the dynamic interactions between microglia and other cells, such as neurons, astrocytes, oligodendrocytes,and endothelial cells within the brain parenchyma and the neurovascular unit.展开更多
Objective To investigate the trends of lipid profiles and dyslipidemia among Chinese adults from 2002 to 2015.Methods Data were collected from three nationally representative cross-sectional surveys.Fasting venous blo...Objective To investigate the trends of lipid profiles and dyslipidemia among Chinese adults from 2002 to 2015.Methods Data were collected from three nationally representative cross-sectional surveys.Fasting venous blood samples were collected and serum lipids were tested by biochemical analysis and enzymatic determination.Lipid levels and the prevalence of dyslipidemia among adults were analyzed with complex sampling weighting adjustment for age and gender.Results The weighted means of TC, TG, and LDL-c significantly increased linearly from 3.93, 1.12, and 2.12 mmol/L in 2002 to 4.59, 1.41, and 2.78 mmol/L in 2010 and then to 4.63, 1.47, and 2.87 mmol/L in 2015, respectively;by contrast, HDL-c levels decreased significantly from 1.30 mmol/L to 1.26 mmol/L over the same period.Similar trends in mean non-HDL-c and lipid-related ratios were observed.The weighted dyslipidemia prevalence linearly increased;in particular, hypercholesterolemia increased from 1.6% to 5.6% and then to 5.8%, hypertriglyceridemia increased from 5.7% to 13.6% and then to 15.0%, low HDL-c increased from 18.8% to 35.5% and then to 24.9%, and high LDL-c increased from 1.3% to 5.6% and then to 7.2%(P for trend <0.001).Conclusion Dyslipidemia increased among Chinese adults from 2002 to 2015.Development of a comprehensive strategy to decrease lipid levels in this population is urgently required.展开更多
As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatmen...As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatments of AIH are immunosuppressant application and liver transplantation.It is considered that lack of good animal AIH models is the main reason for the shortage of a simple and efficient cure.The Concanavalin A (Con A) model is a typical and well established model for investigating T-cell and macrophage dependent liver injury in mice,which closely mimics the pathogenesis mechanisms and pathological changes of patients,and is regarded as the best experimental model for AIH research so far.In this paper we eluci-dated the pathogenic mechanisms of AIH and the evolution of relative animal models.We go on to further focus on Con A-induced liver injury from the point of immunological mechanisms and the change of cytokine levels.Finally,we manifested the clinical significance of the AIH animal models and the challenges they would meet during their future development.展开更多
Objective To estimate the burden of cirrhosis and other chronic liver diseases caused by specific etiologies in China.Methods Data from the Global Burden of Disease Study 2016(GBD 2016)were used.We evaluated the burde...Objective To estimate the burden of cirrhosis and other chronic liver diseases caused by specific etiologies in China.Methods Data from the Global Burden of Disease Study 2016(GBD 2016)were used.We evaluated the burden by analyzing age-sex-province-specific prevalence,mortality,and disability-adjusted lifeyears(DALYs)of 33 provinces in China.Results From 1990 to 2016,prevalence cases in thousands increased by 73.7%from 6833.3(95%UI:6498.0–7180.6)to 11869.6(95%UI:11274.6–12504.7).Age-standardized mortality and DALY rates per100,000 decreased by 51.2%and 53.3%,respectively.Male and elderly people(aged≥60 years)preponderance were found for prevalence,mortality,and DALYs.The number of prevalence cases,deaths,and DALYs due to hepatitis C virus(HCV)increased by 86.6%,8.7%,and 0.9%,respectively.Also,age-standardized prevalence rates decreased in 31 provinces,but increased in Yunnan and Shandong.The Socio-demographic Index(SDI)values were negatively correlated with age-standardized mortality and DALY rates by provinces in 2016;the correlation coefficients were-0.817 and-0.828,respectively.Conclusion Cirrhosis and other chronic liver diseases remain a huge health burden in China,with the increase of population and the aging of population.Hepatitis B virus(HBV)remains the leading cause of the health burden in China.展开更多
Objective： To investigate whether elevated homocysteine levels were a predictor of subsequent coronary heart disease （CHD） mortality, cardiovascular mortality or all-cause mortality in the general population by a m...Objective： To investigate whether elevated homocysteine levels were a predictor of subsequent coronary heart disease （CHD） mortality, cardiovascular mortality or all-cause mortality in the general population by a meta- analysis. Methods： In a systematic search conducted in the databases of PubMed and Embase prior to October 2013, we identified relevant prospective observational studies evaluating the association between baseline homocysteine levels and CHD mortality, cardiovascular or all-cause mortality in the general population. Pooled adjust risk ratio （RR） and corresponding 95% confidence interval （CI） were calculated separately for categorical risk estimates and con- tinuous risk estimates. Results： Twelve studies with 23 623 subjects were included in the meta-analysis. Comparing the highest to lowest homocysteine level categories, CHD mortality increased by 66% （RR 1.66; 95% CI 1.12-2.47; P=-0.012）, cardiovascular mortality increased by 68% （RR 1.68; 95% CI 1.04-2.70; P=0.033）, and all-cause mortality increased by 93% （RR 1.93; 95% CI 1.54-2.43; P〈0.001）. Moreover, for each 5 pmol/L homocysteine increment, the pooled RR was 1.52 （95% CI 1.26-1.84; ,〈0.001） for CHD mortality, 1.32 （95% CI 1.08-1.61; P=0.006） for cardio- vascular mortality, and 1.27 （95% CI 1.03-1.55; P=-0.023） for all-cause mortality. Conclusions： Elevated homocysteine levels are an independent predictor for subsequent cardiovascular mortality or all-cause mortality, and the risks were more pronounced among elderly persons.展开更多
Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on lo...Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).展开更多
AIM: To investigate predictive risk factors associated with complications in the endoscopic removal of foreign bodies from the upper gastrointestinal tract.METHODS: We retrospectively reviewed the medical records of 1...AIM: To investigate predictive risk factors associated with complications in the endoscopic removal of foreign bodies from the upper gastrointestinal tract.METHODS: We retrospectively reviewed the medical records of 194 patients with a diagnosis of foreign body impaction in the upper gastrointestinal tract,confirmed by endoscopy,at two university hospital in South Korea.Patient demographic data,including age,gender,intention to ingestion,symptoms at admission,and comorbidities,were collected.Clinical features of the foreign bodies,such as type,size,sharpness of edges,number,and location,were analyzed.Endoscopic data those were analyzed included duration of foreign body impaction,duration of endoscopic performance,endoscopic device,days of hospitalization,complication rate,30-d mortality rate,and the number of operationsrelated to foreign body removal.RESULTS: The types of upper gastrointestinal foreign bodies included fish bones,drugs,shells,meat,metal,and animal bones.The locations of impacted foreign bodies were the upper esophagus(57.2%),mid esophagus(28.4%),stomach(10.8%),and lower esophagus(3.6%).The median size of the foreign bodies was 26.2 ± 16.7 mm.Among 194 patients,endoscopic removal was achieved in 189,and complications developed in 51 patients(26.9%).Significant complications associated with foreign body impaction and removal included deep lacerations with minor bleeding(n = 31,16%),ulcer(n = 11,5.7%),perforation(n = 3,1.5%),and abscess(n = 1,0.5%).Four patients underwent operations because of incomplete endoscopic foreign body extraction.In multivariate analyses,risk factors for endoscopic complications and failure were sharpness(HR = 2.48,95%CI: 1.07-5.72; P = 0.034) and a greater than 12-h duration of impaction(HR = 2.42,95%CI: 1.12-5.25,P = 0.025).CONCLUSION: In cases of longer than 12 h since foreign body ingestion or sharp-pointed objects,rapid endoscopic intervention should be provided in patients with ingested foreign bodies.展开更多
It is widely known that branched chain amino acids（BCAA） are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA（isoleucine, le...It is widely known that branched chain amino acids（BCAA） are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA（isoleucine, leucine and valine） regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including：（1） Insufficient or excessive levels of BCAA in the diet enhances lipolysis.（2） BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.（3）Supplementation of leucine in the diet enhances meat quality in finishing pigs.（4） BCAA are beneficial for mammary health, milk quality and embryo growth.（5） BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.（6） BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood（decreased BCAA catabolism） are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.展开更多
Total saponins of Panax notoginseng （PNS） have been shown to ameliorate renal interstitial fibrosis. Ginsenoside Rg 1, a panaxatriol saponin, is one of the major active molecules from PNS. The present study was unde...Total saponins of Panax notoginseng （PNS） have been shown to ameliorate renal interstitial fibrosis. Ginsenoside Rg 1, a panaxatriol saponin, is one of the major active molecules from PNS. The present study was undertaken to investigate the effect of ginsenoside Rgl on renal fibrosis in rats with unilateral ureteral obstruction （UUO）. The rats were randomly divided into 3 groups： sham-operation （n=15）, UUO （n=15） and UUO with ginsenoside Rgl treatment （n=15, 50 mg per kg body weight, intraperitoneally （i.p.） injected）. The rats were sacrificed on Days 7 and 14 after the surgery. Histological examination demonstrated that ginsenoside Rgl significantly inhibited interstitial fibrosis including tubular injury as well as collagen deposition, u-smooth muscle actin （α-SMA） and E-cadherin are two markers of tubular epithelial-myofibroblast transition （TEMT）. Interestingly, ginsenoside Rgl notably decreased α-SMA expression and simultaneously enhanced E-cadherin expression. The messenger RNA （mRNA） of transforming growth factor-β1 （TGF-β1）, a key mediator to regulate TEMT, in the obstructed kidney increased dramatically, but was found to decrease significantly after administration of ginsenoside Rg 1. Further study showed that ginsenoside Rgl considerably decreased the levels of both active TGF-β1 and phosphorylated Smad2 （pSmad2）. Moreover, ginsenoside Rgl substantially suppressed the expression of thrombospondin-1 （TSP-1）, a cytokine which can promote the transcription of TGF-β1 mRNA and the activation of latent TGF-β1. These results suggest that ginsenoside Rgl inhibits renal interstitial fibrosis in rats with UUO. The mechanism might be partly related to the blocking of TEMT via suppressing the expression of TSP-1.展开更多
The prevalence of cardiovascular diseases （CVDs） is associated with the socioeconomic prosperity, lifestyle changes, accelerated process of ageing and urbanization. The prevalence of CVDs is continuously increasing ...The prevalence of cardiovascular diseases （CVDs） is associated with the socioeconomic prosperity, lifestyle changes, accelerated process of ageing and urbanization. The prevalence of CVDs is continuously increasing in China and will remain an upward trend in the next 10 years. CVDs are the leading cause of death for Chinese in both urban area and rural area. Nowadays, 41.09% of deaths in rural area and 42.52% of deaths in urban area are caused by CVDs in China. The burden of CVDs remains heavy and has become an important public health problem. Effective strategies should be enforced urgently for the prevention of CVDs under the supervision of the government. In 2012, the Ministry of Health of China and 14 governmental departments jointly issued the Work Plan for Chronic Disease Prevention and Control in China （2012-2015）, a guideline for the prevention of chronic diseases, especially CVDs in China.展开更多
To compare differences among the Medieval Warm Period (MWP), Little Ice Age (LIA), and 20th century global warming (20CW), six sets of transient and equilibrium simulations were generated using the climate system mode...To compare differences among the Medieval Warm Period (MWP), Little Ice Age (LIA), and 20th century global warming (20CW), six sets of transient and equilibrium simulations were generated using the climate system model FGOALS_gl. This model was developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences. The results indicate that MWP warming is evident on a global scale, except for at mid-latitudes of the North Pacific. However, the magnitude of the warming is weaker than that in the 20th century. The warming in the high latitudes of the Northern Hemisphere is stronger than that in the Southern Hemisphere. The LIA cooling is also evident on a global scale, with a strong cooling over the high Eurasian continent, while the cooling center is over the Arctic domain. Both the MWP and the 20CW experiments exhibit the strongest warming anomalies in the middle troposphere around 200-300 hPa, but the cooling center of the LIA experiment is seen in the polar surface of the Northern Hemisphere. A comparison of model simulation against the reconstruction indicates that model's performance in simulating the surface air temperature changes during the warm periods is better than that during the cold periods. The consistencies between model and reconstruction in lower latitudes are better than those in high latitudes. Comparison of the inter-annual variability mode of East Asian summer monsoon (EASM) rainfall during the MWP, LIA and 20CW reveals a similar rainfall anomalies pattern. However, the time spectra of the principal component during the three typical periods of the last millennium are different, and the quasi-biannual oscillation is more evident during the two warm periods. At a centennial time scale, the external mode of the EASM variability driven by the changes of effective solar radiation is determined by the changes of large scale land-sea thermal contrast. The rainfall anomalies over the east of 1展开更多
Background Cervical cancer is the second most common cause of death from cancer among women worldwide. Human papillomavirus （HPV） plays a central role in the etiology of cervical cancer. It is important to describe ...Background Cervical cancer is the second most common cause of death from cancer among women worldwide. Human papillomavirus （HPV） plays a central role in the etiology of cervical cancer. It is important to describe the prevalence of HPV infection in different types of cervical lesions and to explore the relation between HPV viral load and the severity of cervical lesions. Methods To describe the HPV infection prevalence and viral load in different age groups, we retrospectively investigated 6405 cases of women who were organized by their units to take health-examination. They were given Hybrid Capture II tests between January 2005 and December 2006. The correlation between HPV viral load and pathology was assessed. Results Overall HPV infection prevalence was 29.1% （1864/6405）, while in women 18-20 years old it was 54.4% （31/57）, the highest among all age groups. After declining rapidly, HPV prevalence stabilized at about 30.0% in women aged 30 and older. Of the 6405 women, 1483 women had a colposcopic biopsy and 33.2% （492/1483） were positive for HPV DNA. Twenty-one percent of women with a normal diagnosis （238/1095） had HPV infection, a statistically significantly lower prevalence than in women with cervical lesions, including those with cervical intraepithelial neoplasia （68.8% in CIN1,66.7% in CIN2, and 76.5% in CIN3） or with cervical cancer （94.1%）. The correlation coefficient between viral load and cervical lesion severity was 0.134, which was not statistically significant （P=0.075）. Viral load values in women with CINs and cervical cancer were calculated, and no significant differences were identified. Conclusions The prevalence of high-risk HPV infection among women attending hospitals for health-examination in Shanghai is similar to the worldwide rate. HPV viral load can distinguish cervical lesions from normal individuals but cannot adequately predict the severity of cervical lesions.展开更多
AIM: To compare the liver transplantation-free (LTF) survival rates between patients who underwent transjugular intrahepatic portosystemic shunts (TIPS) and those who underwent paracentesis by an updated meta-analysis...AIM: To compare the liver transplantation-free (LTF) survival rates between patients who underwent transjugular intrahepatic portosystemic shunts (TIPS) and those who underwent paracentesis by an updated meta-analysis that pools the effects of both number of deaths and time to death.展开更多
Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective preventio...Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective prevention strategies.Methods:The data on incidence,mortality,and disability-adjusted life-years(DALYs)of GC in China from1990 to 2019 were obtained from the Global Burden of Disease Study(2019).The estimated annual percentage change(EAPC)was calculated to evaluate the temporal trends of disease burden of GC,and the package Nordpred in the R program was used to perform an age-period-cohort analysis to predict the numbers and rates of incidence and mortality in the next 25 years.Results:The number of incident cases of GC increased from 317.34 thousand in 1990 to 612.82 thousand in2019,while the age-standardized incidence rate(ASIR)of GC decreased from 37.56 per 100,000 in 1990 to 30.64 per 100,000 in 2019,with an EAPC of-0.41[95%confidence interval(95%CI):-0.77,-0.06].Pronounced temporal trends in mortality and DALYs of GC were observed.In the next 25 years,the numbers of new GC cases and deaths are expected to increase to 738.79 thousand and 454.80 thousand,respectively,while the rates of incidence and deaths should steadily decrease.The deaths and DALYs attributable to smoking were different for males and females.Conclusions:In China,despite the fact that the rates of GC have decreased during the past three decades,the numbers of new GC cases and deaths increased,and will continue to increase in the next 25 years.Additional strategies are needed to reduce the burden of GC,such as screening and early detection,novel treatments,and the prevention of risk factors.展开更多
The split-Hopkinson pressure bar(SHPB)and digital image correlation(DIC)techniques are combined to analyze the dynamic compressive failure process of coal samples,and the box fractal dimension is used to quantitativel...The split-Hopkinson pressure bar(SHPB)and digital image correlation(DIC)techniques are combined to analyze the dynamic compressive failure process of coal samples,and the box fractal dimension is used to quantitatively analyze the dynamic changes in the coal sample cracks under impact load conditions with different loading rates.The experimental results show that the fractal dimension can quantitatively describe the evolution process of coal fractures under dynamic load.During the dynamic compression process,the evolution of the coal sample cracks presents distinct stages.In the crack propagation stage,the fractal dimension increases rapidly with the progress of loading,and in the crack widening stage,the fractal dimension increases slowly with the progress of loading.The initiation of the crack propagation phase of the coal samples gradually occurs more quickly with increasing loading rate;the initial cracks appear earlier.At the same loading time point,when the loading rate is greater,the fractal dimension of the cracks observed in the coal sample is greater.展开更多
文摘The genome sequence of the Severe Acute Respiratory Syndrome (SARS)-associated virus provides essential information for the identification of pathogen(s), exploration of etiology and evolution, interpretation of transmission and pathogenesis, development of diagnostics, prevention by future vaccination, and treatment by developing new drugs. We report the complete genome sequence and comparative analysis of an isolate (BJ01) of the coronavirus that has been recognized as a pathogen for SARS. The genome is 29725 nt in size and has 11 ORFs (Open Reading Frames). It is composed of a stable region encoding an RNA-dependent RNA polymerase (composed of 2 ORFs) and a variable region representing 4 CDSs (coding sequences) for viral structural genes (the S, E, M, N proteins) and 5 PUPs (putative uncharacterized proteins). Its gene order is identical to that of other known coronaviruses. The sequence alignment with all known RNA viruses places this virus as a member in the family of Coronaviridae. Thirty putative substitutions have been identified by comparative analysis of the 5 SARS- associated virus genome sequences in GenBank. Fifteen of them lead to possible amino acid changes (non-synonymous mutations) in the proteins. Three amino acid changes, with predicted alteration of physical and chemical features, have been detected in the S protein that is postulated to beinvolved in the immunoreactions between the virus and its host. Two amino acid changes have been detected in the Mprotein, which could be related to viral envelope formation. Phylogenetic analysis suggests the possibility of non-human origin of the SARS-associated viruses but provides noevidence that they are man-made. Further efforts should focus on identifying the etiology of the SARS-associated virus and ruling out conclusively the existence of otherpossible SARS-related pathogen(s).
文摘AIM: To investigate coping mechanisms, constipation symptoms and anorectal physiology in 80 constipated subjects and 18 controls.METHODS: Constipation was diagnosed by Rome Ⅱ criteria.Coping ability and anxiety/depression were assessed by validated questionnaires. Transit time and balloon distension test were performed.RESULTS: 34.5% patients were classified as slow transit type of constipation. The total colonic transit time (56 h vs 10 h, P＜0.0001) and rectal sensation including urge sensation (79 mL vs 63 mL, P = 0.019) and maximum tolerable volume (110 mL vs95 mL, P = 0.03) differed in patients and controls. Constipated subjects had significantly higher anxiety and depression scores and lower SF-36 scores in all categories. They also demonstrated higher scores of'monitoring' coping strategy (14+6 vs9+3, P = 0.001),which correlated with the rectal distension sensation (P = 0.005), urge sensation (P=0.002), and maximum tolerable volume (P = 0.035). The less use of blunting strategy predicted slow transit constipation in both univariate (P = 0.01) and multivariate analysis (P = 0.03).CONCLUSION: Defective or ineffective use of coping strategies may be an important etiology in functional constipation and subsequently reflected in abnormal anorectal physiology.
文摘Major and profound changes have taken place in China over the past 30 years. Rapid socioeconomic progress has exerted a great impact on lifestyle, ranging from food, clothing, working and living conditions, and means of transportation to leisure activities and entertainment. At the same time, new health problems have emerged, and health services are facing new challenges. Presently, cardiovascular diseases （CVD） are among the top health problems of the Chinese people, and pose a serious challenge to all engaged in the prevention and control of these diseases. An epidemic of CVD in China is emerging as a result of lifestyle changes, urbanization and longevity. Both national policy decision-making and medical practice urgently need an authoritative report which comprehensively reflects the trends in the epidemic of CVD and current preventive measures. Since 2005, guided by the Bureau of Disease Prevention of the Ministry of Health of the People＇s Republic of China and the National Center for Cardiovascular Diseases of China, nationwide experts in the fields of epidemiology, clinical medicine and health economics in the realms of CVD, cerebrovascular disease, diabetes and chronic kidney disease, completed the Report on Cardiovascular Diseases in China every year. The report aims to provide a timely review of the trend of the epidemic and to assess the progress of prevention and control of CVD. In addition, as the report is authoritative, representative and readable, it will become an information platform in the CVD field and an important reference book for government, academic institutes, medical organizations and clinical physicians. This publication is expected to play a positive role in the prevention and control of CVD in China. We present an abstract from the Report on Cardiovascular Diseases in China （2010）, including trends in CVD, morbidity and mortality of major CVDs, up-to-date assessment of risk factors, as well as health resources for CVD, and a profile of medical expenditure, with the aim of p
基金the National Natural Science Foundation of China (81571132, 81873743, and 81801223)Fundamental Research Funds for the Central Universities, China (2017KFYXJJ107 and 2017KFYXJJ124)the National Institutes of Health, USA (R01NS088627)
文摘Ischemic stroke is a leading cause of morbidity and mortality worldwide. Resident microglia are the principal immune cells of the brain, and the first to respond to the pathophysiological changes induced by ischemic stroke. Traditionally, it has been thought that microglial activation is deleterious in ischemic stroke, and therapies to suppress it have been intensively explored. However,increasing evidence suggests that microglial activation is also critical for neurogenesis, angiogenesis, and synaptic remodeling, thereby promoting functional recovery after cerebral ischemia. Here, we comprehensively review the dual role of microglia during the different phases of ischemic stroke, and the possible mechanisms controlling the post-ischemic activity of microglia. In addition, we discuss the dynamic interactions between microglia and other cells, such as neurons, astrocytes, oligodendrocytes,and endothelial cells within the brain parenchyma and the neurovascular unit.
基金supported by the National Health and Family Planning Commission(formerly the Ministry of Health of the People’s Republic of China)Medical Reform Major Program:China Nutrition and Health Surveillance(2010-2012)and Chinese Adults Chronic Diseases and Nutrition Surveillance(2015)
文摘Objective To investigate the trends of lipid profiles and dyslipidemia among Chinese adults from 2002 to 2015.Methods Data were collected from three nationally representative cross-sectional surveys.Fasting venous blood samples were collected and serum lipids were tested by biochemical analysis and enzymatic determination.Lipid levels and the prevalence of dyslipidemia among adults were analyzed with complex sampling weighting adjustment for age and gender.Results The weighted means of TC, TG, and LDL-c significantly increased linearly from 3.93, 1.12, and 2.12 mmol/L in 2002 to 4.59, 1.41, and 2.78 mmol/L in 2010 and then to 4.63, 1.47, and 2.87 mmol/L in 2015, respectively;by contrast, HDL-c levels decreased significantly from 1.30 mmol/L to 1.26 mmol/L over the same period.Similar trends in mean non-HDL-c and lipid-related ratios were observed.The weighted dyslipidemia prevalence linearly increased;in particular, hypercholesterolemia increased from 1.6% to 5.6% and then to 5.8%, hypertriglyceridemia increased from 5.7% to 13.6% and then to 15.0%, low HDL-c increased from 18.8% to 35.5% and then to 24.9%, and high LDL-c increased from 1.3% to 5.6% and then to 7.2%(P for trend <0.001).Conclusion Dyslipidemia increased among Chinese adults from 2002 to 2015.Development of a comprehensive strategy to decrease lipid levels in this population is urgently required.
基金Supported by Program for Excellent Talents of Anhui Province,No.2006JQ1196
文摘As a chronic inflammatory disease of the liver,the pathogenic mechanisms of autoimmune hepatitis (AIH) have not yet been elucidated,with prognosis and diagnosis remaining unsatisfied.Currently the only viable treatments of AIH are immunosuppressant application and liver transplantation.It is considered that lack of good animal AIH models is the main reason for the shortage of a simple and efficient cure.The Concanavalin A (Con A) model is a typical and well established model for investigating T-cell and macrophage dependent liver injury in mice,which closely mimics the pathogenesis mechanisms and pathological changes of patients,and is regarded as the best experimental model for AIH research so far.In this paper we eluci-dated the pathogenic mechanisms of AIH and the evolution of relative animal models.We go on to further focus on Con A-induced liver injury from the point of immunological mechanisms and the change of cytokine levels.Finally,we manifested the clinical significance of the AIH animal models and the challenges they would meet during their future development.
文摘Objective To estimate the burden of cirrhosis and other chronic liver diseases caused by specific etiologies in China.Methods Data from the Global Burden of Disease Study 2016(GBD 2016)were used.We evaluated the burden by analyzing age-sex-province-specific prevalence,mortality,and disability-adjusted lifeyears(DALYs)of 33 provinces in China.Results From 1990 to 2016,prevalence cases in thousands increased by 73.7%from 6833.3(95%UI:6498.0–7180.6)to 11869.6(95%UI:11274.6–12504.7).Age-standardized mortality and DALY rates per100,000 decreased by 51.2%and 53.3%,respectively.Male and elderly people(aged≥60 years)preponderance were found for prevalence,mortality,and DALYs.The number of prevalence cases,deaths,and DALYs due to hepatitis C virus(HCV)increased by 86.6%,8.7%,and 0.9%,respectively.Also,age-standardized prevalence rates decreased in 31 provinces,but increased in Yunnan and Shandong.The Socio-demographic Index(SDI)values were negatively correlated with age-standardized mortality and DALY rates by provinces in 2016;the correlation coefficients were-0.817 and-0.828,respectively.Conclusion Cirrhosis and other chronic liver diseases remain a huge health burden in China,with the increase of population and the aging of population.Hepatitis B virus(HBV)remains the leading cause of the health burden in China.
文摘Objective： To investigate whether elevated homocysteine levels were a predictor of subsequent coronary heart disease （CHD） mortality, cardiovascular mortality or all-cause mortality in the general population by a meta- analysis. Methods： In a systematic search conducted in the databases of PubMed and Embase prior to October 2013, we identified relevant prospective observational studies evaluating the association between baseline homocysteine levels and CHD mortality, cardiovascular or all-cause mortality in the general population. Pooled adjust risk ratio （RR） and corresponding 95% confidence interval （CI） were calculated separately for categorical risk estimates and con- tinuous risk estimates. Results： Twelve studies with 23 623 subjects were included in the meta-analysis. Comparing the highest to lowest homocysteine level categories, CHD mortality increased by 66% （RR 1.66; 95% CI 1.12-2.47; P=-0.012）, cardiovascular mortality increased by 68% （RR 1.68; 95% CI 1.04-2.70; P=0.033）, and all-cause mortality increased by 93% （RR 1.93; 95% CI 1.54-2.43; P〈0.001）. Moreover, for each 5 pmol/L homocysteine increment, the pooled RR was 1.52 （95% CI 1.26-1.84; ,〈0.001） for CHD mortality, 1.32 （95% CI 1.08-1.61; P=0.006） for cardio- vascular mortality, and 1.27 （95% CI 1.03-1.55; P=-0.023） for all-cause mortality. Conclusions： Elevated homocysteine levels are an independent predictor for subsequent cardiovascular mortality or all-cause mortality, and the risks were more pronounced among elderly persons.
基金partially supported by the National Key Research and Development Program of China(2016YFA0600104)supported by donations made by Delos Living LLC,and the Cyrus Tang Foundation+2 种基金supported by the National Natural Science Foundation of China(41471419)Beijing Institute of Urban Planningsupported by the Fundamental Research Funds for the Central Universities(CCNU19TD002).
文摘Land use reflects human activities on land.Urban land use is the highest level human alteration on Earth,and it is rapidly changing due to population increase and urbanization.Urban areas have widespread effects on local hydrology,climate,biodiversity,and food production[1,2].However,maps,that contain knowledge on the distribution,pattern and composition of various land use types in urban areas,are limited to city level.The mapping standard on data sources,methods,land use classification schemes varies from city to city,due to differences in financial input and skills of mapping personnel.To address various national and global environmental challenges caused by urbanization,it is important to have urban land uses at the national and global scales that are derived from the same or consistent data sources with the same or compatible classification systems and mapping methods.This is because,only with urban land use maps produced with similar criteria,consistent environmental policies can be made,and action efforts can be compared and assessed for large scale environmental administration.However,despite of the fact that a number of urban-extent maps exist at global scales[3,4],more detailed urban land use maps do not exist at the same scale.Even at big country or regional levels such as for the United States,China and European Union,consistent land use mapping efforts are rare[5,6](e.g.,https://sdi4apps.eu/open_land_use/).
基金Supported by Gachon University Gil Medical Center,No.2013-49 and No.2013-35,to Cho JH and Kim YJ
文摘AIM: To investigate predictive risk factors associated with complications in the endoscopic removal of foreign bodies from the upper gastrointestinal tract.METHODS: We retrospectively reviewed the medical records of 194 patients with a diagnosis of foreign body impaction in the upper gastrointestinal tract,confirmed by endoscopy,at two university hospital in South Korea.Patient demographic data,including age,gender,intention to ingestion,symptoms at admission,and comorbidities,were collected.Clinical features of the foreign bodies,such as type,size,sharpness of edges,number,and location,were analyzed.Endoscopic data those were analyzed included duration of foreign body impaction,duration of endoscopic performance,endoscopic device,days of hospitalization,complication rate,30-d mortality rate,and the number of operationsrelated to foreign body removal.RESULTS: The types of upper gastrointestinal foreign bodies included fish bones,drugs,shells,meat,metal,and animal bones.The locations of impacted foreign bodies were the upper esophagus(57.2%),mid esophagus(28.4%),stomach(10.8%),and lower esophagus(3.6%).The median size of the foreign bodies was 26.2 ± 16.7 mm.Among 194 patients,endoscopic removal was achieved in 189,and complications developed in 51 patients(26.9%).Significant complications associated with foreign body impaction and removal included deep lacerations with minor bleeding(n = 31,16%),ulcer(n = 11,5.7%),perforation(n = 3,1.5%),and abscess(n = 1,0.5%).Four patients underwent operations because of incomplete endoscopic foreign body extraction.In multivariate analyses,risk factors for endoscopic complications and failure were sharpness(HR = 2.48,95%CI: 1.07-5.72; P = 0.034) and a greater than 12-h duration of impaction(HR = 2.42,95%CI: 1.12-5.25,P = 0.025).CONCLUSION: In cases of longer than 12 h since foreign body ingestion or sharp-pointed objects,rapid endoscopic intervention should be provided in patients with ingested foreign bodies.
基金supported by the National Key Basic Research Program(S.Y.Q.,Grant Number 2012CB124704)
文摘It is widely known that branched chain amino acids（BCAA） are not only elementary components for building muscle tissue but also participate in increasing protein synthesis in animals and humans. BCAA（isoleucine, leucine and valine） regulate many key signaling pathways, the most classic of which is the activation of the m TOR signaling pathway. This signaling pathway connects many diverse physiological and metabolic roles. Recent years have witnessed many striking developments in determining the novel functions of BCAA including：（1） Insufficient or excessive levels of BCAA in the diet enhances lipolysis.（2） BCAA, especially isoleucine, play a major role in enhancing glucose consumption and utilization by up-regulating intestinal and muscular glucose transporters.（3）Supplementation of leucine in the diet enhances meat quality in finishing pigs.（4） BCAA are beneficial for mammary health, milk quality and embryo growth.（5） BCAA enhance intestinal development, intestinal amino acid transportation and mucin production.（6） BCAA participate in up-regulating innate and adaptive immune responses.In addition, abnormally elevated BCAA levels in the blood（decreased BCAA catabolism） are a good biomarker for the early detection of obesity, diabetes and other metabolic diseases. This review will provide some insights into these novel metabolic and physiological functions of BCAA.
基金Project (No. 30170437) supported by the National Natural Science Foundation of China
文摘Total saponins of Panax notoginseng （PNS） have been shown to ameliorate renal interstitial fibrosis. Ginsenoside Rg 1, a panaxatriol saponin, is one of the major active molecules from PNS. The present study was undertaken to investigate the effect of ginsenoside Rgl on renal fibrosis in rats with unilateral ureteral obstruction （UUO）. The rats were randomly divided into 3 groups： sham-operation （n=15）, UUO （n=15） and UUO with ginsenoside Rgl treatment （n=15, 50 mg per kg body weight, intraperitoneally （i.p.） injected）. The rats were sacrificed on Days 7 and 14 after the surgery. Histological examination demonstrated that ginsenoside Rgl significantly inhibited interstitial fibrosis including tubular injury as well as collagen deposition, u-smooth muscle actin （α-SMA） and E-cadherin are two markers of tubular epithelial-myofibroblast transition （TEMT）. Interestingly, ginsenoside Rgl notably decreased α-SMA expression and simultaneously enhanced E-cadherin expression. The messenger RNA （mRNA） of transforming growth factor-β1 （TGF-β1）, a key mediator to regulate TEMT, in the obstructed kidney increased dramatically, but was found to decrease significantly after administration of ginsenoside Rg 1. Further study showed that ginsenoside Rgl considerably decreased the levels of both active TGF-β1 and phosphorylated Smad2 （pSmad2）. Moreover, ginsenoside Rgl substantially suppressed the expression of thrombospondin-1 （TSP-1）, a cytokine which can promote the transcription of TGF-β1 mRNA and the activation of latent TGF-β1. These results suggest that ginsenoside Rgl inhibits renal interstitial fibrosis in rats with UUO. The mechanism might be partly related to the blocking of TEMT via suppressing the expression of TSP-1.
文摘The prevalence of cardiovascular diseases （CVDs） is associated with the socioeconomic prosperity, lifestyle changes, accelerated process of ageing and urbanization. The prevalence of CVDs is continuously increasing in China and will remain an upward trend in the next 10 years. CVDs are the leading cause of death for Chinese in both urban area and rural area. Nowadays, 41.09% of deaths in rural area and 42.52% of deaths in urban area are caused by CVDs in China. The burden of CVDs remains heavy and has become an important public health problem. Effective strategies should be enforced urgently for the prevention of CVDs under the supervision of the government. In 2012, the Ministry of Health of China and 14 governmental departments jointly issued the Work Plan for Chronic Disease Prevention and Control in China （2012-2015）, a guideline for the prevention of chronic diseases, especially CVDs in China.
基金the National Natural Science Foundation of China (40890054)
文摘To compare differences among the Medieval Warm Period (MWP), Little Ice Age (LIA), and 20th century global warming (20CW), six sets of transient and equilibrium simulations were generated using the climate system model FGOALS_gl. This model was developed by the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics, Institute of Atmospheric Physics, Chinese Academy of Sciences. The results indicate that MWP warming is evident on a global scale, except for at mid-latitudes of the North Pacific. However, the magnitude of the warming is weaker than that in the 20th century. The warming in the high latitudes of the Northern Hemisphere is stronger than that in the Southern Hemisphere. The LIA cooling is also evident on a global scale, with a strong cooling over the high Eurasian continent, while the cooling center is over the Arctic domain. Both the MWP and the 20CW experiments exhibit the strongest warming anomalies in the middle troposphere around 200-300 hPa, but the cooling center of the LIA experiment is seen in the polar surface of the Northern Hemisphere. A comparison of model simulation against the reconstruction indicates that model's performance in simulating the surface air temperature changes during the warm periods is better than that during the cold periods. The consistencies between model and reconstruction in lower latitudes are better than those in high latitudes. Comparison of the inter-annual variability mode of East Asian summer monsoon (EASM) rainfall during the MWP, LIA and 20CW reveals a similar rainfall anomalies pattern. However, the time spectra of the principal component during the three typical periods of the last millennium are different, and the quasi-biannual oscillation is more evident during the two warm periods. At a centennial time scale, the external mode of the EASM variability driven by the changes of effective solar radiation is determined by the changes of large scale land-sea thermal contrast. The rainfall anomalies over the east of 1
文摘Background Cervical cancer is the second most common cause of death from cancer among women worldwide. Human papillomavirus （HPV） plays a central role in the etiology of cervical cancer. It is important to describe the prevalence of HPV infection in different types of cervical lesions and to explore the relation between HPV viral load and the severity of cervical lesions. Methods To describe the HPV infection prevalence and viral load in different age groups, we retrospectively investigated 6405 cases of women who were organized by their units to take health-examination. They were given Hybrid Capture II tests between January 2005 and December 2006. The correlation between HPV viral load and pathology was assessed. Results Overall HPV infection prevalence was 29.1% （1864/6405）, while in women 18-20 years old it was 54.4% （31/57）, the highest among all age groups. After declining rapidly, HPV prevalence stabilized at about 30.0% in women aged 30 and older. Of the 6405 women, 1483 women had a colposcopic biopsy and 33.2% （492/1483） were positive for HPV DNA. Twenty-one percent of women with a normal diagnosis （238/1095） had HPV infection, a statistically significantly lower prevalence than in women with cervical lesions, including those with cervical intraepithelial neoplasia （68.8% in CIN1,66.7% in CIN2, and 76.5% in CIN3） or with cervical cancer （94.1%）. The correlation coefficient between viral load and cervical lesion severity was 0.134, which was not statistically significant （P=0.075）. Viral load values in women with CINs and cervical cancer were calculated, and no significant differences were identified. Conclusions The prevalence of high-risk HPV infection among women attending hospitals for health-examination in Shanghai is similar to the worldwide rate. HPV viral load can distinguish cervical lesions from normal individuals but cannot adequately predict the severity of cervical lesions.
文摘AIM: To compare the liver transplantation-free (LTF) survival rates between patients who underwent transjugular intrahepatic portosystemic shunts (TIPS) and those who underwent paracentesis by an updated meta-analysis that pools the effects of both number of deaths and time to death.
基金澳大利亚研究委员会(ARC)基金The Lexicon Project:Analysing Pedagogical Naming Systems from Different Cultures to Reconceptualise Classroom Practice and Advance Educational Theory(项目编号:DP140101361)全国教育科学"十三五"规划2018年度青年专项课题"形式与功能:中美芬数学课堂关键教学行为比较研究"(项目编号:EHA180480)的阶段性成果
基金supported by the National Key Research and Development Program of China(No.2017YFC0907003)the National Natural Science Foundation of China(No.81973116 and 81573229)the Joint Research Funds for Shandong University and Karolinska Institute(No.SDU-KI-2020-03)。
文摘Objective:China is one of the countries with the heaviest burden of gastric cancer(GC)in the world.Understanding the epidemiological trends and patterns of GC in China can contribute to formulating effective prevention strategies.Methods:The data on incidence,mortality,and disability-adjusted life-years(DALYs)of GC in China from1990 to 2019 were obtained from the Global Burden of Disease Study(2019).The estimated annual percentage change(EAPC)was calculated to evaluate the temporal trends of disease burden of GC,and the package Nordpred in the R program was used to perform an age-period-cohort analysis to predict the numbers and rates of incidence and mortality in the next 25 years.Results:The number of incident cases of GC increased from 317.34 thousand in 1990 to 612.82 thousand in2019,while the age-standardized incidence rate(ASIR)of GC decreased from 37.56 per 100,000 in 1990 to 30.64 per 100,000 in 2019,with an EAPC of-0.41[95%confidence interval(95%CI):-0.77,-0.06].Pronounced temporal trends in mortality and DALYs of GC were observed.In the next 25 years,the numbers of new GC cases and deaths are expected to increase to 738.79 thousand and 454.80 thousand,respectively,while the rates of incidence and deaths should steadily decrease.The deaths and DALYs attributable to smoking were different for males and females.Conclusions:In China,despite the fact that the rates of GC have decreased during the past three decades,the numbers of new GC cases and deaths increased,and will continue to increase in the next 25 years.Additional strategies are needed to reduce the burden of GC,such as screening and early detection,novel treatments,and the prevention of risk factors.
基金Projects(51822403,51827901)supported by the National Natural Science Foundation of ChinaProject(2019ZT08G315)supported by the Department of Science and Technology of Guangdong Province,China。
文摘The split-Hopkinson pressure bar(SHPB)and digital image correlation(DIC)techniques are combined to analyze the dynamic compressive failure process of coal samples,and the box fractal dimension is used to quantitatively analyze the dynamic changes in the coal sample cracks under impact load conditions with different loading rates.The experimental results show that the fractal dimension can quantitatively describe the evolution process of coal fractures under dynamic load.During the dynamic compression process,the evolution of the coal sample cracks presents distinct stages.In the crack propagation stage,the fractal dimension increases rapidly with the progress of loading,and in the crack widening stage,the fractal dimension increases slowly with the progress of loading.The initiation of the crack propagation phase of the coal samples gradually occurs more quickly with increasing loading rate;the initial cracks appear earlier.At the same loading time point,when the loading rate is greater,the fractal dimension of the cracks observed in the coal sample is greater.
