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1Research progress of monitoring, forecasting, and prevention of rockburst in underground coal mining in China显示文摘As one of the dynamic disasters of coal mines,rockburst seriously affects underground safe coal mining.Based on the laboratory test,field test,and theoretical analysis,this study proposed the principle of the rock burst induced by the combination of dynamic and static stresses and divided such rock burst into three types,including induced by primary dynamic stress,mainly induced by dynamic stress,and by dynamic stress in low critical stress state.The expressions of the static stress induced by coal mining and dynamic stress induced by mining tremors were obtained.Moreover,theories and technologies at home and abroad were summarized concerning the monitoring,forecasting,and preventing of rockburst.These mainly include the zoning and leveling forecasting method,electromagnetic radiation technology,elastic wave and seismic wave computed tomography technologies in aspect of rockburst monitoring,as well as the intensity weakening theory,the strong-soft-strong structure effect,the directional hydraulic fracturing technology,the roadway support system in regards of rockburst prevention.The prospect of rockburst development suggested that researches concerning the rockburst mechanism should be quantitatively developed around the roadway and coalface surrounding coal-rock mass.It should be focused on the rockburst mechanism and prevention technology of mining with over 1,000 km deep and mining in large tectonic zone.In addition,the monitoring and prevention of rockburst should be based on rockburst mechanism.Linming Dou Zonglong Mu Zhenlei Li Anye Cao Siyuan Gong 2014International Journal of Coal Science & Technology2014,1,3:64
2Numerical Simulation and Analysis of Solid-liquid Two-phase Flow in Centrifugal Pump显示文摘The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far.There exist two main problems in the operation of the two-phase flow pumps,i.e.,low overall efficiency and severe abrasion.In this study,the three-dimensional,steady,incompressible,and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics(CFD) code based on the mixture model of the two-phase flow and the RNG k-two-equation turbulence model,in which the influences of rotation and curvature are fully taken into account.The coupling between impeller and volute is implemented by means of the frozen rotor method.The simulation results predicted indicate that the solid phase properties in two-phase flow,especially the concentration,the particle diameter and the density,have strong effects on the hydraulic performance of the pump.Both the pump head and the efficiency are reduced with increasing particle diameter or concentration.However,the effect of particle density on the performance is relatively minor.An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration.The suction side of the blade is subject to much more severe abrasion than the pressure side.The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump,and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.ZHANG Yuliang LI Yi CUI Baoling ZHU Zuchao DOU Huashu 2013Chinese Journal of Mechanical Engineering2013,26,1:55
3Paeoniflorin suppresses TGF-β mediated epithelial- mesenchymal transition in pulmonary fibrosis through a Smad-dependent pathway显示文摘Yu JI Yan-nong DOU Qian-wen ZHAO Ji-zhou ZHANG Yan YANG Ting WANG Yu-feng XIA Yue DAI Zhi-feng WEI 2016Acta Pharmacologica Sinica2016,37,6:48
4Plasma levels of omentin-1 and visfatin in senile patients with coronary heart disease and heart failure显示文摘Objective:To investigate the alteration of plasma levels of omentin-1 and visfatin in elderly patients with coronary heart disease(CHD)and heart failure.Methods:Plasma omentin-1 and visfatin levels were measured in 90 subjects(29 stable angina pectoris(SAP)cases,30 unstable angina pectoris(UAP)cases and 31 age-and sex-matched healthy controls(age≥60 years)by enzyme-linked immunosorbent assay methods.According to the New York Heart Association classification.59 CHDs were divided into three groups:functional I class,11 cases;functional II/III class,36 cases;and functional IV class,12 cases.Results:The plasma level of omentin-1in CHO patients was significantly lower than thai of the control group.Otnenlin-lin SAP group and UAP group were significantly lower compared to the control group(there was no statistical significance between UAP group and SAP group;P>0.05).The plasma level of visfatin in CHD patients was significandy higher than that of the control group.Similarly,visfatin in SAP group and UAP group were all significantly higher compared to the control group,while there was no statistical significance between UAP group,and SAP group.The plasma omentin-1 level was negatively correlated with SBP(r=-0.264,P<0.05),positively correlated with HDL-c level(r=0.271,P<0.05);the plasma visfatin level was positively correlated with TC(r=0.292,P<0.05),negatively correlated with HDL-c level(r=-0.266,P<0.05).There was a negative correlation between plasma omentin-1 and visfatin levels(r=-0.280,P<0.05).Moreover,multiple linear stepwise regression analysis showed that omentin-1 and visfatin levels might be affected by HDL-c level.Logistic regression analysis showed that visfatin could be an independent risk factor of CHD.Conclusions:Decreased levels of omentin-1 and increased levels of visfatin may be involved in the occurrence and development of CHD.Omentin-1 and visfatin,independently,may be protective and pro-inflammatory cytokines.Additionally,both omentin-1 and visfatin may be related to lipid metabolism.Visfatin may be an independent risk factor of CHD.Xiu-Hua Wang Ling-Zhi Dou Can Gu Xiao-Qing Wang 2014Asian Pacific Journal of Tropical Medicine2014,7,1:38
5Prevention and forecasting of rock burst hazards in coal mines显示文摘Rock bursts signify extreme behavior in coal mine strata and severely threaten the safety of the lives of miners, as well as the effectiveness and productivity of miners. In our study, an elastic-plastic-brittle model for the deformation and failure of coal/rock was established through theoretical analyses, laboratory experiments and field testing, simulation and other means, which perfectly predict sudden and delayed rock bursts. Based on electromagnetic emission (EME), acoustic emission (AE) and microseism (MS) effects in the process from deformation until impact rupture of coal-rock combination samples, a multi-parameter identification of premonitory technology was formed, largely depending on these three forms of emission. Thus a system of classification for forecasting rock bursts in space and time was established. We have presented the intensity weakening theory for rock bursts and a strong-soft-strong (3S) structural model for controlling the impact on rock surrounding roadways, with the objective of laying a theoretical foundation and establishing references for parameters for the weakening control of rock bursts. For the purpose of prevention, key technical parameters of directional hydraulic fracturing are revealed. Based on these results, as well as those from deep-hole controlled blasting in coal seams and rock, integrated control techniques were established and anti-impact hydraulic props, suitable for roadways subject to hazards from rockbursts have also been developed. These technologies have been widely used in most coal mines in China, subject to these hazards and have achieved remarkable economic and social benefits.DOU Lin-ming LU Cai-ping MU Zong-long GAO Ming-shi 2009Mining Science and Technology2009,19,5:36
6Effect of pre-procedural statin therapy on myocardial no-reflow following percutaneous coronary intervention: a meta analysis显示文摘LI Xiang-dong YANG Yue-jin HAO Yong-chen YANG Ying ZHAO Jing-lin DOU Ke-fei GU Dong-feng 2013Chinese Medical Journal2013,,9:35
7Apelin-13 inhibits apoptosis and excessive autophagy in cerebral ischemia/reperfusion injury显示文摘Apelin-13 is a novel endogenous ligand for an angiotensin-like orphan G-protein coupled receptor,and it may be neuroprotective against cerebral ischemia injury.However,the precise mechanisms of the effects of apelin-13 remain to be elucidated.To investigate the effects of apelin-13 on apoptosis and autophagy in models of cerebral ischemia/reperfusion injury,a rat model was established by middle cerebral artery occlusion.Apelin-13(50μg/kg)was injected into the right ventricle as a treatment.In addition,an SH-SY5Y cell model was established by oxygen-glucose deprivation/reperfusion,with cells first cultured in sugar-free medium with 95%N2 and 5%CO2 for 4 hours and then cultured in a normal environment with sugar-containing medium for 5 hours.This SH-SY5Y cell model was treated with 10-7 M apelin-13 for 5 hours.Results showed that apelin-13 protected against cerebral ischemia/reperfusion injury.Apelin-13 treatment alleviated neuronal apoptosis by increasing the ratio of Bcl-2/Bax and significantly decreasing cleaved caspase-3 expression.In addition,apelin-13 significantly inhibited excessive autophagy by regulating the expression of LC3B,p62,and Beclin1.Furthermore,the expression of Bcl-2 and the phosphatidylinositol-3-kinase(PI3K)/Akt/mammalian target of rapamycin(mTOR)pathway was markedly increased.Both LY294002(20μM)and rapamycin(500 nM),which are inhibitors of the PI3K/Akt/mTOR pathway,significantly attenuated the inhibition of autophagy and apoptosis caused by apelin-13.In conclusion,the findings of the present study suggest that Bcl-2 upregulation and mTOR signaling pathway activation lead to the inhibition of apoptosis and excessive autophagy.These effects are involved in apelin-13-induced neuroprotection against cerebral ischemia/reperfusion injury,both in vivo and in vitro.The study was approved by the Animal Ethical and Welfare Committee of Jining Medical University,China(approval No.2018-JS-001)in February 2018.Zi-Qi Shao Shan-Shan Dou Jun-Ge Zhu Hui-Qing Wang Chun-Mei Wang Bao-Hua Cheng Bo Bai 2021Neural Regeneration Research2021,16,6:35
8Intravenous injection of mesenchymal stem cells is effective in treating liver fibrosis显示文摘AIM: To compare the influence of different transplant sites in bone marrow mesenchymal stem cell (MSC)-based therapy for liver fibrosis. METHODS: MSCs isolated from Sprague Dawley (SD) rats were induced into hepatocyte-like cells. Liver fibrosis in SD rats was induced with carbon tetrachloride. Following hepatocyte induction in vitro, 4',6-diamidino- 2-phenylindole (DAPI)-labeled MSCs were transplanted by intravenous, intrahepatic, and intraperitoneal injection. Histopathological staining, immunohistochemistry, and biochemical analysis were used to compare the morphological and functional liver regeneration among different MSC injection modalities. The expression differences of interleukins, growth factor, extracellular matrix, matrix metalloproteinases, and tissue inhibitor of metalloproteinase were examined by real-time reverse transcription-polymerase chain reaction (RT-PCR) andenzyme linked immunosorbent assay (ELISA). RESULTS: Four days after exposure to hepatocyte differentiation medium, MSCs that did not express hepatocyte markers could express α-fetoprotein, albumin, and cytokeratin 18. The results of histopathological staining, immunohistochemistry, and biochemical analysis indicated that intravenous injection is more effective at rescuing liver failure than other injection modalities. DAPI-labeled cells were found around liver lobules in all three injection site groups, but the intravenous group had the highest number of cells. PCR and ELISA analysis indicated that interleukin-10 (IL-10) was highest in the intravenous group, whereas il1β, il6, tnfα and tgfβ, which can be regulated by IL10 and are promoters of liver fibrosis, were significantly lower than in the other groups. CONCLUSION: MSC administration is able to protect against liver fibrosis. Intravenous injection is the most favorable treatment modality through promotion of IL10 expression.Wei Zhao Jun-Jie Li Da-Yong Cao Xiao Li Lin-Ying Zhang Yong He Shu-Qiang Yue De-Sheng Wang Ke-Feng Dou 2012World Journal of Gastroenterology2012,18,10:32
9Intravoxel incoherent motion diffusion-weighted magnetic resonance imaging for predicting histological grade of hepatocellular carcinoma:Comparison with conventional diffusion-weighted imaging显示文摘AIM To compare intravoxel incoherent motion(IVIM)-derived parameters with conventional diffusion-weighted imaging(DWI) parameters in predicting the histological grade of hepatocellular carcinoma(h CC) and to evaluate the correlation between the parameters and the histological grades.METHODS A retrospective study was performed. Sixty-two patients with surgically confirmed h CCs underwent diffusion-weighted magnetic resonance imaging with twelve b values(10-1200 s/mm^2). The apparent diffusion coefficient(ADC), pure diffusion coefficient(D), pseudo-diffusion coefficient(D*), and perfusion fraction(f) were calculated by two radiologists. The IVIM and conventional DWI parameters were compared among the different grades by using analysis of variance(ANOVA) and the Kruskal-Wallis test. Receiver operating characteristic(ROC) analysis was performed to evaluate the diagnostic efficiency of distinguishing between low-grade(grade 1, G1) and high-grade(grades 2 and 3, G2 and G3) hC C. The correlation between the parameters and the histological grades was assessed by using the Spearman correlation test. Bland-Altman analysis was used to evaluate the reproducibility of the two radiologists' measurements.RESULTS The differences in the ADC and D values among the groups with G1, G2, and G3 histological grades of HCCs were statistically significant(P < 0.001). The D* and f values had no significant differences among the different histological grades of h CC(P > 0.05). The ROC analyses demonstrated that the D and ADC values had better diagnostic performance in differentiating the low-grade h CC from the high-grade h CC, with areas under the curve(AUCs) of 0.909 and 0.843, respectively, measured by radiologist 1 and of 0.911 and 0.852, respectively, measured by radiologist 2. The following significant correlations were obtained between the ADC, D, and D~* values and the histological grades: r =-0.619(P < 0.001), r =-0.628(P < 0.001), and r =-0.299(P = 0.018), respectively, as measured by radiologist 1; r =-0.622(P < 0.001), r =-0.633(P < 0.001), and r =-0.303(P = 0.017), respectively, as measured by radiologist 2. The intra-class correlation coefficient(ICC) values between the two observers were 0.996 for ADC, 0.997 for D, 0.996 for D*, and 0.992 for f values, which indicated excellent interobserver agreement in the measurements between the two observers.CONCLUSION The IVIM-derived D and ADC values show better diagnostic performance in differentiating high-grade hC C from low-grade hC C, and there is a moderate to good correlation between the ADC and D values and the histological grades.Shao-Cheng Zhu Yue-Hua Liu Yi Wei Lin-Lin Li She-Wei Dou Ting-Yi Sun Da-Peng Shi 2018World Journal of Gastroenterology2018,24,8:33
10Relationship of hepatitis B virus infection of placental barrier and hepatitis B virus intra-uterine transmission mechanism显示文摘AIM: To explore the mechanism of intra-uterine transmission,the HBV infection status of placental tissue and in vitro cultured placental trophoblastic cells was tested through in vivo and in vitro experiments. METHODS: A variety of methods,such as ELISA,RT- PCR,IHC staining and immunofluorescent staining were employed to test the HBV marker positive pregnant women's placenta and in vitro cultured placental trophoblastic cells. RESULTS: The HBV DNA levels in pregnant women's serum and fetal cord blood were correlated. For those cord blood samples positive for HBV DNA,their maternal blood levels of HBV DNA were at a high level. The HBsAg IHC staining positive cells could be seen in the placental tissues and the presence of HBV DNA detected. After co-incubating the trophoblastic cells and HBV DNA positive serum in vitro,the expressions of both HBsAg and HBV DNA could be detected. CONCLUSION: The mechanism of HBV intra-uterine infection may be due to that HBV breaches the placental barrier and infects the fetus.Han Bai Lin Zhang Li Ma Xiao-Guang Dou Guo-He Feng Gui-Zhen Zhao 2007World Journal of Gastroenterology2007,13,26:30
11Differences in symptoms and pre-hospital delay among acute myocardial infarction patients according to ST-segment elevation on electrocardiogram: an analysis of China Acute Myocardial Infarction (CAMI) registry显示文摘Background: Approximately 70% patients with acute myocardial infarction (AMI) presented without ST-segment elevation on electrocardiogram. Patients with non-ST segment elevation myocardial infarction (NSTEMI) often presented with atypical symptoms, which may be related to pre-hospital delay and increased risk of mortality. However, up to date few studies reported detailed symptomatology of NSTEMI, particularly among Asian patients. The objective of this study was to describe and compare symptoms and presenting characteristics of NSTEMI vs. STEMI patients. Methods: We enrolled 21,994 patients diagnosed with AMI from China Acute Myocardial Infarction (CAMI) Registry between January 2013 and September 2014. Patients were divided into 2 groups according to ST-segment elevation: ST-segment elevation (STEMI) group and NSTEMI group. We extracted data on patients' characteristics and detailed symptomatology and compared these variables between two groups. Results: Compared with patients with STEMI (N=16,315), those with NSTEMI (N=5679) were older, more often females and more often have comorbidities. Patients with NSTEMI were less likely to present with persistent chest pain (54.3% vs.71.4%), diaphoresis (48.6% vs.70.0%), radiation pain (26.4% vs.33.8%), and more likely to have chest distress (42.4% vs.38.3%) than STEMI patients (all P<0.0001). Patients with NSTEMI were also had longer time to hospital. In multivariable analysis, NSTEMI was independent predictor of presentation without chest pain (odds ratio: 1.974, 95% confidence interval:1.849-2.107). Conclusions: Patients with NSTEMI were more likely to present with chest distress and pre-hospital patient delay compared with patients with STEMI. It is necessary for both clinicians and patients to learn more about atypical symptoms of NSTEMI in order to rapidly recognize myocardial infarction.Rui Fu Chen-Xi Song Ke-Fei Dou Jin-Gang Yang Hai-Yan Xu Xiao-Jin Gao Qian-Qian Liu Han Xu Yue-Jin Yang 2019Chinese Medical Journal2019,,5:29
12A systematic analysis of pneumatosis cystoids intestinalis显示文摘AIM:To increase the understanding,diagnosis and treatment of pneumatosis cystoides intestinalis(PCI)and to find the characteristics and potential cause of the disease in China.METHODS:We report here one case of PCI in a 70-year-old male patient who received a variety of treatment methods.Then,we systematically searched the PCI eligible literature published from an available Chinese database from May 2002 to May 2012,including CBM,CBMDisc,CMCC,VIP,Wanfang,and CNKI.The key words were pneumatosis cystoides intestinalis,pneumatosis,pneumatosis intestinalis,pneumatosis coli and mucosal gas.The patients' information,histories,therapies,courses,and outcomes were reviewed.RESULTS:The study group consisted of 239 PCI cases(male:female = 2.4:1)from 77 reported incidents.The mean age was 45.3 ± 15.6 years,and the median illness course was 6 mo.One hundred and sixty patients(66.9%)were in high altitude areas.In addition,43.5%(104/239)of the patients had potential PCI-related disease,and 16.3% had complications with intestinal obstruction and perforation.The most common symptom was abdominal pain(53.9%),followed by diarrhea(53.0%),distention(42.4%),nausea and vomiting(14.3%),bloody stool(12.9%),mucous stool(12.0%)and constipation(7.8%).Most multiple pneumocysts developed in the submucosa of the colon(69.9%).The efficacy of the treatments by combined modalities,surgery,endoscopic treatment,conservative approach,oxygen,and antibiotics were 100%,100%,100%,93.3%,68.3% and 26.3%,respectively.CONCLUSION:PCI can be safely managed by conservative treatments,presents more frequently in males,in the large bowel and submucosa,than in females,in the small intestine and subserosa.High altitude residence maybe associated with the PCI etiology.Li-Li Wu Yun-Sheng Yang Yan Dou Qing-Sen Liu 2013World Journal of Gastroenterology2013,19,30:27
13Effect of Bcl-2 and Bax on survival of side population cells from hepatocellular carcinoma cells显示文摘AIM: To understand the role and significance of side population (SP) cells from hepatocellular carcinoma (HCC) in hepatocarcinogenesis, development, relapse and metastasis, we simulated the denutrition conditions that cancer cells experience in clinical therapy, observed the different anti-apoptosis ability of SP cells and non-SP cells under such conditions, and established the possible effects of P53, Bcl-2 and Bax on survival of SP cells. METHODS: We used ? ow cytometry to analyze and sort the SP and non-SP cells in established HCC lines MHCC97 and hHCC. We evaluated cell proliferation by methyl thiazolyl tetrazolium (MTT) assay and investigated the expression of p53, bcl-2 and bax genes during denutrition, by RT-PCR and immuno? uorescence staining. RESULTS: The percentage of SP cells in the two established HCC lines was 0.25% and 0.5%, respectively. SP cells had greater anti-apoptosis and proliferation ability than non-SP cells. Expression of Bcl-2 and Bax in SP and non-SP cells differed during denutrition. The former was up-regulated in SP cells, and the latter was up-regulated in non-SP cells. CONCLUSION: It may be that different upstream molecules acted and led to different expression levels of Bcl-2 and Bax in these two cell lines. There was a direct relationship between up-regulation of Bcl-2 and down-regulation of Bax and higher anti-apoptosis ability in SP cells. It may be that the existence and activity of SP cells are partly responsible for some of the clinical phenomena which are seen in HCC, such as relapse or metastasis. Further research on SP cells may have potential applications in the f ield of anticancer therapy.Jing Fan Ren Li Rui Zhang Hai-Liang Liu Ning Zhang Fu-Qing Zhang Ke-Feng Dou 2007World Journal of Gastroenterology2007,13,45:27
14Directional hydraulic fracturing to control hard-roof rockburst in coal mines显示文摘Hard roof is the main factor that induces rock-burst.In view of the present obvious weakness of control measures for hard roof rockburst in domestic collieries,the mechanism and field application of directional hydraulic fracturing technology for rock-burst prevention have been investigated in this paper using theoretical analysis and numerical simulation.The results show that the weighting span of the main roof and the released kinetic energy as well as the total elastic energy decreased greatly after the directional fracturing of hard roof with the mining progression,thereby reducing the rockburst hazard degree to coal body.The directional hydraulic fracturing technology was carried out in 6305 working face of Jisan Coal Mine to prevent rockburst.Field practices have proved that this technology is much simpler and safer to operate with better prevention effect compared with blasting.By optimizing the operation procedures and developing a new technology of automated high-pressure delivery pipe,the maximum fracturing radius now reaches more than 9 m and the borehole depth exceeds 20 m.Additionally,drilling cutting method was applied to monitor the stress of the coal mass before and after the fracturing,and the drill cuttings dropped significantly which indicates that the burst prevention effect of directional hydraulic fracturing technology is very remarkable.The research results of this paper have laid a theoretical and practical foundation for the widespread application of the directional hydraulic fracturing technology in China.Fan Jun Dou Linming He Hu Du Taotao Zhang Shibin Gui Bing Sun Xinglin 2012International Journal of Mining Science and Technology2012,22,2:28
15Isolation and Identification of Cancer Stem-Like Cells from Murine Melanoma Cell Lines显示文摘In current study,cancer stem-like cells in the murine melanoma B16F10 cells were investigated.CD phenotypes of the B16F10 cells were analyzed by flow cytometry,and the specific CD phenotype cells from the B16F10 cells were isolated by MACS.Then we used colony formation assay in soft agar media,the cell growth assay in serum-free culture media as well as the tumorigenicity investigation of the specific CD phenotype cells in C57BL/6 mice, respectively,to identify cancer stem-like cells in the B16F10 cells.The results showed that the B16F10 cells could form spherical clones in serum-free culture media,and the rate of clonegenesis of CD133 + ,CD44 + and CD44 + CD133 + cells was higher than that of CD133 - ,CD44 - and CD44 + CD133 - cells in soft agar media,respectively. The tumorigenic potential of CD133 + ,CD44 + ,CD44 + CD133 + cells and CD44 + CD133 + CD24 + cells was stronger than that of CD133 - ,CD44 - ,CD44 + CD133 - cells and CD44 + CD133 + CD24 - cells in mice,respectively.In conclusion,the CD44 + CD133 + CD24 + cells have some biological properties of cancer stem-like cells or are highly similar to the characteristics of cancer stem cells(CSC).These results provide an important method for identifying cancer stem-like cells in B16F10 cells and for further cancer target therapy.Jun Dou Meng Pan Ping Wen Yating Li Quan Tang Lili Chu Fengshu Zhao Chuilian Jiang Weihua Hu Kai Hu Ning Gu 2007Cellular & Molecular Immunology2007,4,6:25
16Preparation and microstructure characterization of a nano-sized Ti^(4+)-doped AgSnO_2 electrical contact material显示文摘A Ti4+-doped nano-structured AgSnO2 material was prepared using sol-gel method and characterized by X-ray diffraction (XRD), transmis-sion electron microscopy (TEM), and scanning electron microscopy (SEM). The results show that Ti4+ cations are successfully doped into the crystal lattice of SnO2, and thus significantly improve the electrical conductivity of the sample. Furthermore, the coating of Ag on Ti4+-doped SnO2 nano-sized particles enhances the surface wettability and enables the resulting AgSnO2 material to have better mechanical properties.ZHENG Ji LI Songlin DOU Fuqi LI Tonghui 2009Rare Metals2009,28,1:24
17Rock burst mechanism analysis in an advanced segment of gob-side entry under different dip angles of the seam and prevention technology显示文摘In order to investigate the frequent occurrences of rock burst in gob-side entry during the mining process of the mining zone No. 7, the mechanical model of main roof of fully-mechanized caving mining before breaking was established by the Winkler foundation beam theory, and the stress evolution law of surrounding rock with different dip angles of the seam during the mining process was analyzed by using FLAC3 D. The results show that: with the dip angle changing from 45° to 0°, the solid-coal side of gobside entry begins to form an L-shaped stress concentration zone at a dip angle of 30°, and the stress concentration degree goes to higher and higher levels. However, the stress concentration degree of the coalpillar side goes to lower and lower levels; the influence range and peak stress of the abutment at the lateral strata of adjacent gob increase with dip angle decreasing and reach a maximum value at a dip angle of 0°, but the tailgate is not affected; the abutment pressure superposition of two adjacent gobs leads to stress concentration further enhancing in both sides of gob-side entry. With the influence of strong mining disturbance, rock burst is easily induced by dynamic and static combined load in the advanced segment of gob-side entry. To achieve stability control similar to that in the roadway, the key control strategy is to reinforce surrounding rock and unload both sides. Accordingly, the large-diameter drilling and high-pressure water injection combined unloading and reinforced support cooperative control technology was proposed and applied in field test. The results of Electromagnetic Emission(EME) and field observation showed that unloading and surrounding rock control effect was obvious.Yang Zengqiang Liu Chang Tang Shichuan Dou Linming Cao Jinglong 2018International Journal of Mining Science and Technology2018,28,6:24
18Analysis of observations on the urban surface energy balance in Beijing显示文摘1 年(20092010 ) 大小从在一个 325-m 塔的三垂直的层位于闹市区北京的传感器获得的城市的表面精力平衡(SEB ) 被分析。结果显示出那:(1 ) 从 325-m 塔的大小代表位于半潮湿的温暖适度的大陆人季风气候地区的城市的 SEB 特征。在典型热、多雨的夏天,感冒和干燥冬季,测量鲍恩比率在冬季在夏天和最大值是最小的。在 140 m 测量春天,夏天,秋天,和冬季的鲍恩比率分别地是 2.86, 0.82, 1.17,和 4.16。(2 ) 在 140-m 的高度(在经常的流动层) ,中午反照率是 0.10 夏天, 0.12 为春天和秋天,并且 0.14 为冬季。白天的比率理智的热流动,潜伏的热流动,和捕捞放射的存储热流动是 0.25, 0.16,和 0.59 清楚天空的天,并且 0.33, 0.19,和 0.48 为多云的天分别地。(3 ) 在清楚天空的天下面,夜间理智的热流动是几乎零,但是潜伏的热流动比零大。为多云的天,夜间理智的热流动比在冬季的潜伏的热流动稍微大。向上的热流动是的夜间大概由于人为的版本(为夏天的主要潜伏的热,当时为冬季的潜伏、理智的热) 。MIAO ShiGuang DOU JunXia CHEN Fei LI Ju LI AiGuo 2012Science China Earth Sciences2012,55,11:23
19Cycloastragenol upregulates SIRT1 expression,attenuates apoptosis and suppresses neuroinflammation after brain ischemia显示文摘Cycloastragenol(CAG)is the active form of astragaloside V isolated from Astragalus Radix,which displays multiple pharmacological effects.Silent information regulator 1(SIRT1),a classll histone deacetylase,has been shown to play an important role in neuroprotection against cerebral ischemia.In this study,we investigated whether CAG protected against ischemic brain injury and,if so,whether the beneficial effects were associated with the regulation of SIRT1 in the ischemic brain.Mice were subjected to 45 min of middle cerebral artery occlusion(MCAO)followed by reperfusion.CAG(5,10,20 mg/kg)was injected intraperitoneally at the onset of reperfusion,12h later and then twice daily for up to three days.CAG dose-dependently reduced brain infarct volume,significantly ameliorated functional deficits,and prevented neuronal cell oss in MCAO mice.Meanwhile,CAG signicantly reduced matrix metalloproteinase-9 activity,prevented tight junction degradation and subsequently ameliorated blood-brain barier disruption.Moreover,CAG significantly upregulated SIRT1 expression in the ischemic brain but did not directly activate its enzymatic activity.Concomitant with SIRT1 upregulation,CAG reduced p53 acetylation and the ratio of Bax to Bcl-2 in the ischemic brain.CAG also inhibited NF-κB p65 nuclear translocation.As a result,CAG suppressed the mRNA expression of pro-inflammatory cytokines,including TNF-α and IL-1β,and inhibited the activation of microglia and astrocytes in the ischemic brain.Our findings suggest that CAG is neuroprotective against ischemic brain injury in mice and that its beneficial effect may involve SIRT1 upregulation and the inhibition of apoptosis and neuroinflammation in the ischemic brain.Man Li Shichun Li Bao-kai Dou Yving-xiang Zou Hao-zhen Han Dong-xiang Liu Zunji Ke Zhi-fei Wang 2020Acta Pharmacologica Sinica2020,41,8:22
20Clinical significance of diabetes on symptom and patient delay among patients with acute myocardial infarction——an analysis from China Acute Myocardial Infarction(CAMI) registry显示文摘Background Diabetes is frequently associated with poor prognosis among acute myocardial infarction(AMI)patients.Patients with these comorbidities often have atypical symptoms and subsequent delay in treatment.Few studies have reported detailed AMI symptoms in patients with diabetes.This study compared AMI symptoms and presentation characteristics between diabetics and non-diabetics.Methods We included patients from the China AMI registry diagnosed with AMI between January 2013 and September 2014.Baseline characteristics,symptomology,and delay in treatment were compared between diabetics and non-diabetics.Multivariable logistic regression analysis was used to explore independent predictors of atypical symptoms.Results A total of 4450(20.2%)patients had diabetes.They were older,more often women,higher in body mass index,and more likely to have non-ST segment elevation myocardial infarction.Fewer diabetic patients presented with persistent precordial chest pain(63.1%vs.68%,P<0.0001),diaphoresis(60.1%vs.65.6%,P<0.0001),fatigue(16.7%vs.18.3%,P=0.0123),and incontinence(0.4%vs.0.7%,P=0.0093).Time to hospital presentation was longer among patients with diabetes than those without.In multivariable analysis,diabetes was identified as an independent predictor of atypical symptoms(OR:1.112,95%CI:1.034?1.196).Conclusions Our study is the first large-scale study providing evidence that diabetics are less likely to present with typical chest pain and more likely to experience treatment delay when suffering from an AMI.Our results may increase clinician awareness of recognizing AMI patients rapidly to reduce diagnosis and treatment delay,particularly in the context of diabetes.Rui FU Si-Dong LI Chen-Xi SONG Jing-Ang YANG Hai-Yan XU Xiao-Jin GAO Yi XU Jian-Ping ZENG Jun-Nong LI Ke-Fei DOU Yue-Jin YANG on behalf of the CAMI Registry study group Beijing,China 2019Journal of Geriatric Cardiology2019,16,5:21
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