To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the ...To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the equations of elastic potential of coal and gas dilatation energy theory were set up to process a contrast calculation of the sizes of two kinds of energy. The results show that gas dilatation energy is the uppermost energy source causing outburst occurrence. Furthermore, the mathematical model of spherical flow field gas dilatation energy release was established and MATLAB software was applied to make a numerical calculation analysis on the law of gas dilatation energy release. The results indicate that the gas dilatation energy is closely related to gas parameters and its energy index does reflect the possibility of coal seam outburst.展开更多
Introduction Primary liver cancer, the second most common cause of cancer related death worldwide, presents ethnic, etiological, sex, and geographical diversity2 （Figure 1A）. At the histological level, liver cancer ...Introduction Primary liver cancer, the second most common cause of cancer related death worldwide, presents ethnic, etiological, sex, and geographical diversity2 （Figure 1A）. At the histological level, liver cancer includes two major types： hepatocellular carcinoma （HCC, about 80%） and cholangiocarcinoma （CCA, about 15%）. Many etiological factors contribute to HCC development, such as hepatitis B virus （HBV）, hepatitis C virus （HCV）, aflatoxin B1 （AFB1）, alcohol, and metabolic diseases3. By contrast, the major risk factors for CCA are liver flukes （Opisthorchis viverrini and Clonorchis sinensis） and primary sclerosing cholangitis4,展开更多
As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning syste...As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning systems.To reveal the evolution characteristics of coal and gas outburst precursor information in deep rock cross-cut coal uncovering,briquette specimens are constructed and experiments are conducted using a self-developed true triaxial outburst test system.Using acoustic emission monitoring technology,the dynamic failure of coal is monitored,and variations in the root mean square(RMS)of the acoustic emissions allow the effective cracking time and effective cracking gas pressure to be defined.These characteristics are obviously different in deep and shallow coal.The characteristic parameters of gas outburst exhibit stepwise variations at different depths.The RMS and cumulative RMS have stepped failure characteristics with respect to changes in gas pressure.The characteristic parameters of coal failure are negatively correlated with the average in-situ stress and effective stress,but positively correlated with the lateral pressure coefficient of in-situ stress and the critical gas pressure.The transition characteristics are highly sensitive in all cases.The critical depth between deep and shallow coal and gas outbursts is 1700 m.The expansion multiple of acoustic emission intensity from the microfracture stage to the sharp-fracture stage of coal is defined as the outburst risk index,N1.For depths of 1100–1700 m,N1≥7 denotes a higher risk of outburst,whereas at depths of 1700–2500 m,N1≥3 indicates enhanced risk.展开更多
EDITOR'S NOTE: Since May 2004, the people's procuratorates in China have concentrated their efforts on uncovering cases of encroaching upon human rights by government functionaries by abusing their power. The ...EDITOR'S NOTE: Since May 2004, the people's procuratorates in China have concentrated their efforts on uncovering cases of encroaching upon human rights by government functionaries by abusing their power. The move has aroused extensive attention. On this, our staff reporter interviewed Deputy Chief Procurator Wang Zhenchuan, who is in charge of the campaign against human rights violations.展开更多
With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at ...With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at Zhejiang University,assembled an allopolyploid B.juncea genome and uncovered differential homoeolog gene expression influencing selection,which was published in Nature展开更多
Tsinghua University studies reveal secrets from ancient bamboo texts China’s prestigious Tsinghua University recently released preliminary results of research on a rare collection of
BACKGROUND Given most patients with distal malignant biliary obstruction present in the nonresectable stage,palliative endoscopic biliary drainage with fully covered metal stent(FCMS)or uncovered metal stent(UCMS)is t...BACKGROUND Given most patients with distal malignant biliary obstruction present in the nonresectable stage,palliative endoscopic biliary drainage with fully covered metal stent(FCMS)or uncovered metal stent(UCMS)is the only available measure to improve patients’quality of life.Half covered metal stent(HCMS)has been recently introduced commercially.The adverse effects and stent function between FCMS and UCMS have been extensively discussed.AIM To study the duration of stent patency of HCMS and compare it with FCMS and UCMS to optimize biliary drainage in inoperable patients with distal malignant obstruction.Secondary aims in our study included evaluation of patients’survival and the rates of adverse events for each type of stent.METHODS We studied 210 patients and randomized them into three equal groups;HCMS,FCMS and UCMS were inserted endoscopically.RESULTS Stent occlusion occurred in(18.6%,17.1%and 15.7%in HCMS,FCMS and UCMS groups,respectively,P=0.9).Stent migration occurred only in patients with FCMS(8.6%of patients).Cholangitis and cholecystitis occurred in 11.4%and 5.7%of patients,respectively,in FCMS.Tumor growth occurred only in 10 cases among patients with UCMS after a median of 140 d,sludge occurred in nine,seven and one patients in HCMS,FCMS and UCMS,respectively(P=0.04).CONCLUSION Given the prolonged stent functioning time,the use of HCMS is preferred over the use of UCMS and FCMS for optimizing biliary drainage in patients with distal malignant biliary obstruction.展开更多
Background Different stems implantation in ST-segmem elevation myocardial infarction （STEMI） patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to e...Background Different stems implantation in ST-segmem elevation myocardial infarction （STEMI） patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to evaluate the vessel healings after implantation of drug elming stems （DES） with biodegradable or durable polymer or of bare-metal stems （BMS） in patients with ache STEMI. Methods This study included 50 patients, who underwem follow up angiogram and optical coherence tomography （OCT） assessment about one year after percutaneous coronary intervemion （PCI） for STEMI. According to the initial stems types, these patients were classified to durable （n = 19） or biodegradable polymer sirolimus-eluting stems （n = 15）, or BMS （n = 16） groups. The conditions of stem struts coverage and malapposi- tion were analyzed with OCT technique. Results A total of 9003 struts were analyzed： 3299, 3202 and 2502 from durable or biodegradable polymer DES, or BMS, respectively. Strut coverage rate （89.0%, 94.9% and 99.3%, respectively）, malapposition presence （1.7%, 0.03% and 0 of struts, respectively） and average intimal thickness over struts （76 ± 12 μm, 161 ± 30 μm and 292 ± 29 μm, respectively） were significantly differem among different stent groups （all P 〈 0.001）. Conclusions Vessel healing status in STEMI patients is superior after implantation of biodegradable polymer DES than durable polymer DES, while both are inferior to BMS.展开更多
文摘To study the law of gas dilatation energy release of rock cross-cut coal uncovering face, according to the analysis of the physical parameters distribution features of coal and rock mass in front of crosscut face,the equations of elastic potential of coal and gas dilatation energy theory were set up to process a contrast calculation of the sizes of two kinds of energy. The results show that gas dilatation energy is the uppermost energy source causing outburst occurrence. Furthermore, the mathematical model of spherical flow field gas dilatation energy release was established and MATLAB software was applied to make a numerical calculation analysis on the law of gas dilatation energy release. The results indicate that the gas dilatation energy is closely related to gas parameters and its energy index does reflect the possibility of coal seam outburst.
基金supported,in part,by the Precision Medical Research Program from Ministry of Science and Technology of China(Grant No.YL 2017YFC0908400)National Science and Technology Major Project for Infectious Disease and Funding(Grant No.YL 17-163-12-ZT-005-095-01)+2 种基金Science and Technology Commission in Ministry of National Defense of China(Grant No.YL 17-163-12-ZT-005-095-01)Xinwei Wang was supported by the intramural research program of the Center for Cancer Research,National Cancer Institute of the United StatesJunfang Ji was supported by the Thousand Young Talents Plan of China,National Natural Science Foundation of China(Grant No.81672905)
文摘Introduction Primary liver cancer, the second most common cause of cancer related death worldwide, presents ethnic, etiological, sex, and geographical diversity2 （Figure 1A）. At the histological level, liver cancer includes two major types： hepatocellular carcinoma （HCC, about 80%） and cholangiocarcinoma （CCA, about 15%）. Many etiological factors contribute to HCC development, such as hepatitis B virus （HBV）, hepatitis C virus （HCV）, aflatoxin B1 （AFB1）, alcohol, and metabolic diseases3. By contrast, the major risk factors for CCA are liver flukes （Opisthorchis viverrini and Clonorchis sinensis） and primary sclerosing cholangitis4,
基金This research was financially supported by the National Natural Science Foundation of China(51874165,51974148)Liaoning Xingliao Talent Program(XLYC1902106).
文摘As mines become deeper,the potential for coal and gas outbursts in deep rock cross-cut coal uncovering is enhanced.The outburst precursors are unclear,which restricts the effectiveness and reliability of warning systems.To reveal the evolution characteristics of coal and gas outburst precursor information in deep rock cross-cut coal uncovering,briquette specimens are constructed and experiments are conducted using a self-developed true triaxial outburst test system.Using acoustic emission monitoring technology,the dynamic failure of coal is monitored,and variations in the root mean square(RMS)of the acoustic emissions allow the effective cracking time and effective cracking gas pressure to be defined.These characteristics are obviously different in deep and shallow coal.The characteristic parameters of gas outburst exhibit stepwise variations at different depths.The RMS and cumulative RMS have stepped failure characteristics with respect to changes in gas pressure.The characteristic parameters of coal failure are negatively correlated with the average in-situ stress and effective stress,but positively correlated with the lateral pressure coefficient of in-situ stress and the critical gas pressure.The transition characteristics are highly sensitive in all cases.The critical depth between deep and shallow coal and gas outbursts is 1700 m.The expansion multiple of acoustic emission intensity from the microfracture stage to the sharp-fracture stage of coal is defined as the outburst risk index,N1.For depths of 1100–1700 m,N1≥7 denotes a higher risk of outburst,whereas at depths of 1700–2500 m,N1≥3 indicates enhanced risk.
文摘EDITOR'S NOTE: Since May 2004, the people's procuratorates in China have concentrated their efforts on uncovering cases of encroaching upon human rights by government functionaries by abusing their power. The move has aroused extensive attention. On this, our staff reporter interviewed Deputy Chief Procurator Wang Zhenchuan, who is in charge of the campaign against human rights violations.
文摘With the long-term support by the National Natural Science Foundation of China,Ministry of Agriculture,and Science and Technology Department of Zhejiang Province,the research team led by Prof.Zhang Mingfang(张明方)at Zhejiang University,assembled an allopolyploid B.juncea genome and uncovered differential homoeolog gene expression influencing selection,which was published in Nature
文摘Tsinghua University studies reveal secrets from ancient bamboo texts China’s prestigious Tsinghua University recently released preliminary results of research on a rare collection of
文摘BACKGROUND Given most patients with distal malignant biliary obstruction present in the nonresectable stage,palliative endoscopic biliary drainage with fully covered metal stent(FCMS)or uncovered metal stent(UCMS)is the only available measure to improve patients’quality of life.Half covered metal stent(HCMS)has been recently introduced commercially.The adverse effects and stent function between FCMS and UCMS have been extensively discussed.AIM To study the duration of stent patency of HCMS and compare it with FCMS and UCMS to optimize biliary drainage in inoperable patients with distal malignant obstruction.Secondary aims in our study included evaluation of patients’survival and the rates of adverse events for each type of stent.METHODS We studied 210 patients and randomized them into three equal groups;HCMS,FCMS and UCMS were inserted endoscopically.RESULTS Stent occlusion occurred in(18.6%,17.1%and 15.7%in HCMS,FCMS and UCMS groups,respectively,P=0.9).Stent migration occurred only in patients with FCMS(8.6%of patients).Cholangitis and cholecystitis occurred in 11.4%and 5.7%of patients,respectively,in FCMS.Tumor growth occurred only in 10 cases among patients with UCMS after a median of 140 d,sludge occurred in nine,seven and one patients in HCMS,FCMS and UCMS,respectively(P=0.04).CONCLUSION Given the prolonged stent functioning time,the use of HCMS is preferred over the use of UCMS and FCMS for optimizing biliary drainage in patients with distal malignant biliary obstruction.
文摘Background Different stems implantation in ST-segmem elevation myocardial infarction （STEMI） patients may influence the long term prognosis by affecting vessel healings after stenting. The aim of this study was to evaluate the vessel healings after implantation of drug elming stems （DES） with biodegradable or durable polymer or of bare-metal stems （BMS） in patients with ache STEMI. Methods This study included 50 patients, who underwem follow up angiogram and optical coherence tomography （OCT） assessment about one year after percutaneous coronary intervemion （PCI） for STEMI. According to the initial stems types, these patients were classified to durable （n = 19） or biodegradable polymer sirolimus-eluting stems （n = 15）, or BMS （n = 16） groups. The conditions of stem struts coverage and malapposi- tion were analyzed with OCT technique. Results A total of 9003 struts were analyzed： 3299, 3202 and 2502 from durable or biodegradable polymer DES, or BMS, respectively. Strut coverage rate （89.0%, 94.9% and 99.3%, respectively）, malapposition presence （1.7%, 0.03% and 0 of struts, respectively） and average intimal thickness over struts （76 ± 12 μm, 161 ± 30 μm and 292 ± 29 μm, respectively） were significantly differem among different stent groups （all P 〈 0.001）. Conclusions Vessel healing status in STEMI patients is superior after implantation of biodegradable polymer DES than durable polymer DES, while both are inferior to BMS.
