A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The...A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti).展开更多
Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comp...Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern.展开更多
为了提高系统综述和荟萃分析文章报告的质量,2009年由国际著名专家组成的系统综述和荟萃分析优先报告的条目(Preferred Reporting Items for Systematic Reviews and Meta-Analyses,PRISMA)小组在国际重要医学期刊包括《英国医学杂志》...为了提高系统综述和荟萃分析文章报告的质量,2009年由国际著名专家组成的系统综述和荟萃分析优先报告的条目(Preferred Reporting Items for Systematic Reviews and Meta-Analyses,PRISMA)小组在国际重要医学期刊包括《英国医学杂志》、《临床流行病学杂志》、《内科学年鉴》和美国《公共科学图书馆医学杂志》等同步发表了《系统综述与荟萃分析优先报告条目:PRISMA声明》。该标准的制定对于改进和提高系统综述和荟萃分析的报告质量将起到重要作用。该声明较以往制定的《随机对照试验荟萃分析报告质量》(Quality of Reporting of Meta-Analyses),即《QUOROM声明》更加全面、完善。由于近年采国内外对系统综述的高度重视,发表的文章数量也越来越多,因此,有必要规范报告的标准,提高报告的质量。这份声明对系统综述和荟萃分析类文章报告的27个条目及流程图进行了定义和介绍,对相关条目进行了详细的解释和说明。及时向国内读者和临床试验研究人员介绍该声明具有重要的现实意义和学术价值。北京中医药大学循证医学中心刘建平等在第一时间内翻译了该声明,本刊希望通过介绍中文版《系统综述与荟萃分析优先报告的条目:PRISMA声明》,以进一步提高国内系统综述文章撰写和报告的质量,同时也有助于改进研究设计的方法学质量。本文的英文原文"Preferred reporring items for systematic reviews and meta-analyses:the PRISMAstatement"发表于PLoS Med.2009;6(7):e1000097.doi:10.1371/journal.pmed.1000097。该文中文版本由北京中医药大学循证医学中心李迅、曹卉娟翻译,刘建平审校(Tel:010-64286760;E-mail:jianping_l@hotmail.com)。中文译文的翻译出版由国家重点基础研究发展计划(973计划)项目资助(No.200608504602)。展开更多
The homeostasis of free radicals is vital to the evolution and life of oxygen-requiring organisms. Under normal physiological conditions, rates of the production of free radicals are virtually equal to rates of their ...The homeostasis of free radicals is vital to the evolution and life of oxygen-requiring organisms. Under normal physiological conditions, rates of the production of free radicals are virtually equal to rates of their removal. The cytotoxic effect of free radicals is deleterious to cells and mediates the pathogenesis of a wide array of diseases. Therefore, antioxidants (e.g. vitamin C, vitamin E, β-carotene, and glutathione) are essential to the survival, health, and reproduction of animals, including humans. Antioxidants may be classified as nutritionally essential (e.g. vitamin antioxidants), indirectly essential (e.g., dietary fibre), conditionally essential (e.g. flavonoids and other effective phytochemicals) or non-essential. In the body, appropriate nutrition should not only prevent diseases, but also promote free radical homeostasis. Thus, it is crucial to develop useful indicators of oxidative stress, such as the cellular ratio of /, lipid peroxidation, oxidative modification of protein and DNA damage. On the basis of the recent report that the improper therapy of iron deficiency results in free radical-mediated dysfunction of the gastrointestinal tract, it is important to verify whether the formulated requirement of nutrients meet the need of maintaining the homeostasis of free radicals. The recommended intake of vitamin E, vitamin C and other antioxidants may need to be revised so as to protect the body against oxidative stress brought about by endogenous and exogenous factors. In order to delay aging and promote health in humans of all ages, and eliminate oxidative damage in response to the treatment of certain diseases, special nutritional measures should be taken. These measures may include the control of caloric intake, reduction in the absorption of free radicals and electrophilic substances, and adequate provision of antioxidant nutrients as well as effective phytochemicals and nutraceuticals. We predict that the concept of free radical biology will continue to greatly advance life sciences, inclu展开更多
Osteoarthritis （OA） is the most common degenerative joint disease and a major cause of pain and disability in adult individuals. The etiology of OA includes joint injury, obesity, aging, and heredity. However, the d...Osteoarthritis （OA） is the most common degenerative joint disease and a major cause of pain and disability in adult individuals. The etiology of OA includes joint injury, obesity, aging, and heredity. However, the detailed molecular mechanisms of OA initiation and progression remain poorly understood and, currently, there are no interventions available to restore degraded cartilage or decelerate disease progression. The diathrodial joint is a complicated organ and its function is to bear weight, perform physical activity and exhibit a joint-specific range of motion during movement. During OA development, the entire joint organ is affected, including articular cartilage, subchondral bone, synovial tissue and meniscus. A full understanding of the pathological mechanism of OA development relies on the discovery of the interplaying mechanisms among different OA symptoms, including articular cartilage degradation, osteophyte formation, subchondral sclerosis and synovial hyperplasia, and the signaling pathway（s） controlling these pathological processes.展开更多
Based on the summary of the highly precise datings of the metal deposits and related granitic rocks in North China craton and adjacent areas, such as the molybdenite Re-Os datings, 40Ar-39Ar datings of mica, K-feldspa...Based on the summary of the highly precise datings of the metal deposits and related granitic rocks in North China craton and adjacent areas, such as the molybdenite Re-Os datings, 40Ar-39Ar datings of mica, K-feldspar and quartz, some Rb-Sr isochrons, and the SHRIMP zircon U-Pb dating and single grain zircon U-Pb dating, we suggest that the large-scale mineralization in North China craton and adjacent areas take place in three periods of 200-160Ma, 140Ma, and 130-110Ma. Their corresponding geodynamic settings are proposed to be the collision orogenic process, transformation of the tectonic regime, and delamination of the lithosphere, respectively, in light of analyzing the Mesozoic geodynamic evolution in the North China craton.展开更多
Cancer of the pancreas remains one of the deadliest cancer types. Based on the GLOBOCAN 2012 estimates, pancreatic cancer causes more than 331000 deaths per year, ranking as the seventh leading cause of cancer death i...Cancer of the pancreas remains one of the deadliest cancer types. Based on the GLOBOCAN 2012 estimates, pancreatic cancer causes more than 331000 deaths per year, ranking as the seventh leading cause of cancer death in both sexes together. Globally, about 338000 people had pancreatic cancer in 2012, making it the 11^(th) most common cancer. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. Trends for pancreatic cancer incidence and mortality varied considerably in the world. A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. The overall five-year survival rate is about 6%(ranges from 2% to 9%), but this vary very small between developed and developing countries. To date, the causes of pancreatic cancer are still insufficiently known, although certain risk factors have been identified, such as smoking, obesity, genetics, diabetes, diet, inactivity. There are no current screening recommendations for pancreatic cancer, so primary prevention is of utmost importance. A better understanding of the etiology and identifying the risk factors is essential for the primary prevention of this disease.展开更多
About 30% of patients with cirrhosis have diabetes mellitus(DM).Nowadays,it is a matter for debate whether type 2 DM in the absence of obesity and hypertriglyceridemia may be a risk factor for chronic liver disease.DM...About 30% of patients with cirrhosis have diabetes mellitus(DM).Nowadays,it is a matter for debate whether type 2 DM in the absence of obesity and hypertriglyceridemia may be a risk factor for chronic liver disease.DM,which develops as a complication of cirrhosis,is known as "hepatogenous diabetes".Insulin resistance in muscular and adipose tissues and hyperinsulinemia seem to be the pathophysiologic bases of diabetes in liver disease.An impaired response of the islet β-cells of the pancreas and hepatic insulin resistance are also contributory factors.Non-alcoholic fatty liver disease,alcoholic cirrhosis,chronic hepatitis C(CHC) and hemochromatosis are more frequently associated with DM.Insulin resistance increases the failure of the response to treatment in patients with CHC and enhances progression of fibrosis.DM in cirrhotic patients may be subclinical.Hepatogenous diabetes is clinically different from that of type 2 DM,since it is less frequently associated with microangiopathy and patients more frequently suffer complications of cirrhosis.DM increases the mortality of cirrhotic patients.Treatment of the diabetes is complex due to liver damage and hepatotoxicity of oral hypoglycemic drugs.This manuscript will review evidence that exists in relation to:type 2 DM alone or as part of the metabolic syndrome in the development of liver disease;factors involved in the genesis of hepatogenous diabetes;the impact of DM on the clinical outcome of liver disease;the management of DM in cirrhotic patients and the role of DM as a risk factor for the occurrence and exacerbation of hepatocellular carcinoma.展开更多
Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gab...Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 206Pb/238U ages of 91500,GJ1 and TEMORA 1 are 1064.4±4.8 Ma(2σ ),603.2±2.4 Ma(2σ ) and 418.2±2.4 Ma(2σ ),respectively. The relative standard de-viations(RSDs) of 206Pb/238U ages(2σ ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three standard zircons agree with the recommended values within 2σ error. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma(2σ ) and the RSDs of 206Pb/238U ages(2σ ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan(2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements simultaneously by LA-ICP-MS in a small spot size of 20 μm.展开更多
BACKGROUND: Hepatocellular carcinoma (HCC) is a major health problem worldwide. It is the fifth most common cancer in the world, and the third most common cause of cancer-related death. Without specific treatment, the...BACKGROUND: Hepatocellular carcinoma (HCC) is a major health problem worldwide. It is the fifth most common cancer in the world, and the third most common cause of cancer-related death. Without specific treatment, the prognosis is very poor. The goal of management is 'cancer control'-a reduction in its incidence and mortality as well as an improvement in the quality of life of patients with HCC and their families. This article aims to review the current management of HCC and its recent advances. DATA SOURCES: A MEDLINE database search was performed to identify relevant article using the keywords 'hepatocellular carcinoma', 'hepatectomy', 'liver transplantation', and 'local ablative therapy'. Additional papers and book chapters were identified by a manual search of the references from the key articles. RESULTS: Liver resection and liver transplantation remain the options that give the best chance of a cure. Recent evidence suggests that local ablative therapy may offer comparable survival results in patients with small HCC, and preserved liver function. Transarterial chemoembolization (TACE) is the most promising palliative modality for unresectable HCC, but other techniques, such as transarterial radioembolization (TARE), and local ablative therapy, have also shown comparable results. CONCLUSIONS: Early diagnosis of HCC remains a key goal in improving the prognosis of patients. During the last two decades, operative mortality and surgical outcome of liver resection and liver transplantation for HCC have improved. Progress also has been made in multi-modality therapy which can increase the chance of survival and improve the quality of life for patients with advanced HCC.展开更多
Oxidative stress is increased in metabolic syndrome and type 2 diabetes mellitus(T2DM) and this appears to underlie the development of cardiovascular disease,T2 DM and diabetic complications.Increased oxidative stress...Oxidative stress is increased in metabolic syndrome and type 2 diabetes mellitus(T2DM) and this appears to underlie the development of cardiovascular disease,T2 DM and diabetic complications.Increased oxidative stress appears to be a deleterious factor leading toinsulin resistance,dyslipidemia,β-cell dysfunction,impaired glucose tolerance and ultimately leading to T2 DM.Chronic oxidative stress,hyperglycemia and dyslipidemia are particularly dangerous for β-cells from lowest levels of antioxidant,have high oxidative energy requirements,decrease the gene expression of key β-cell genes and induce cell death.If β-cell functioning is impaired,it results in an under production of insulin,impairs glucose stimulated insulin secretion,fasting hyperglycemia and eventually the development of T2 DM.展开更多
Artificial intelligence(AI)aims to mimic human cognitive functions.It is bringing a paradigm shift to healthcare,powered by increasing availability of healthcare data and rapid progress of analytics techniques.We surv...Artificial intelligence(AI)aims to mimic human cognitive functions.It is bringing a paradigm shift to healthcare,powered by increasing availability of healthcare data and rapid progress of analytics techniques.We survey the current status of AI applications in healthcare and discuss its future.AI can be applied to various types of healthcare data(structured and unstructured).Popular AI techniques include machine learning methods for structured data,such as the classical support vector machine and neural network,and the modern deep learning,as well as natural language processing for unstructured data.Major disease areas that use AI tools include cancer,neurology and cardiology.We then review in more details the AI applications in stroke,in the three major areas of early detection and diagnosis,treatment,as well as outcome prediction and prognosis evaluation.We conclude with discussion about pioneer AI systems,such as IBM Watson,and hurdles for real-life deployment of AI.展开更多
Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric ...Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitationand hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.展开更多
基金supported by the National Natural Science Foundation of China (GrantNos. 40821061,90914007,40576030 and 90714010)the State Administration of Foreign Expert Affairs of China (Grant No. B07039)the Special Fund for Basic Scientific Research of Central Colleges,China University of Geosciences
文摘A protocol was established for simultaneous measurements of zircon U-Pb ages and trace elements by LA-ICP-MS at spot sizes of 16 32 μm.This was accomplished by introducing N 2 into ICP to increase the sensitivity.The obtained U-Pb ages for zircon standards GJ-1,TEMORA and SK10-2 are consistent with the preferred values within about 1% uncertainty (2σ) by simple external calibration against zircon standard 91500.Different data reduction softwares could yield different uncertainties for calculation of U-Pb ages.The commercially available program GLITTER4.4 could apply an improper uncertainty calculation strategy,but it may yield artificial high precisions for single analyses.Our trace element analyses indicate that Si is not an ideal internal standard for zircon when calibrated against the NIST glasses.Calibration against the NIST glasses using Si as an internal standard,a systematic deviation of 10% 30% was found for most trace elements including Zr.However,the trace element compositions of zircon can be accurately measured by calibration against multiple reference materials with natural compositions (e.g.,BCR-2G,BHVO-2G and BIR-1G),or calibration against NIST SRM 610 and using Zr as an internal standard.Analyses of two pieces of GJ-1 demonstrate that it is relatively homogenous for most trace elements (except for Ti).
基金co-supported by the National Natural Science Foundation of China(Grant Nos.40133020 and 40272045)the Chinese Ministry of Science and Technology of China(Grant No.G1999043202)the Chinese Academy of Sciences and the Key Laboratory of Continental Dynamics,Northwest University,the Ministry of Education of China.
文摘Using the in situ zircon U-Pb dating method of LA-ICPMS, we analyzed the 31 Ma old SHRIMP U-Pb age of the Yongsheng nepheline syenite from southern Jilin Province under different spot sizes. The obtained ages are comparable with that of SHRIMP in both accuracy and precision. The age is also identical to that of the Yinmawanshan gabbro from the Liaodong Peninsula within error. Both the Yongsheng nepheline syenite and the Yinmawanshan gabbro represent the youngest known exposed intrusions in northeastern and even eastern China. The results indicate the Eocene mantle-derived magmatic underplating, and the rapid crustal uplifting of this region since 30 Ma. The analyses also document extremely high LREE concentrations and relatively flat REE patterns for the zircons from the Yongsheng nepheline syenite, which represent a new type of zircon REE pattern.
文摘为了提高系统综述和荟萃分析文章报告的质量,2009年由国际著名专家组成的系统综述和荟萃分析优先报告的条目(Preferred Reporting Items for Systematic Reviews and Meta-Analyses,PRISMA)小组在国际重要医学期刊包括《英国医学杂志》、《临床流行病学杂志》、《内科学年鉴》和美国《公共科学图书馆医学杂志》等同步发表了《系统综述与荟萃分析优先报告条目:PRISMA声明》。该标准的制定对于改进和提高系统综述和荟萃分析的报告质量将起到重要作用。该声明较以往制定的《随机对照试验荟萃分析报告质量》(Quality of Reporting of Meta-Analyses),即《QUOROM声明》更加全面、完善。由于近年采国内外对系统综述的高度重视,发表的文章数量也越来越多,因此,有必要规范报告的标准,提高报告的质量。这份声明对系统综述和荟萃分析类文章报告的27个条目及流程图进行了定义和介绍,对相关条目进行了详细的解释和说明。及时向国内读者和临床试验研究人员介绍该声明具有重要的现实意义和学术价值。北京中医药大学循证医学中心刘建平等在第一时间内翻译了该声明,本刊希望通过介绍中文版《系统综述与荟萃分析优先报告的条目:PRISMA声明》,以进一步提高国内系统综述文章撰写和报告的质量,同时也有助于改进研究设计的方法学质量。本文的英文原文"Preferred reporring items for systematic reviews and meta-analyses:the PRISMAstatement"发表于PLoS Med.2009;6(7):e1000097.doi:10.1371/journal.pmed.1000097。该文中文版本由北京中医药大学循证医学中心李迅、曹卉娟翻译,刘建平审校(Tel:010-64286760;E-mail:jianping_l@hotmail.com)。中文译文的翻译出版由国家重点基础研究发展计划(973计划)项目资助(No.200608504602)。
文摘The homeostasis of free radicals is vital to the evolution and life of oxygen-requiring organisms. Under normal physiological conditions, rates of the production of free radicals are virtually equal to rates of their removal. The cytotoxic effect of free radicals is deleterious to cells and mediates the pathogenesis of a wide array of diseases. Therefore, antioxidants (e.g. vitamin C, vitamin E, β-carotene, and glutathione) are essential to the survival, health, and reproduction of animals, including humans. Antioxidants may be classified as nutritionally essential (e.g. vitamin antioxidants), indirectly essential (e.g., dietary fibre), conditionally essential (e.g. flavonoids and other effective phytochemicals) or non-essential. In the body, appropriate nutrition should not only prevent diseases, but also promote free radical homeostasis. Thus, it is crucial to develop useful indicators of oxidative stress, such as the cellular ratio of /, lipid peroxidation, oxidative modification of protein and DNA damage. On the basis of the recent report that the improper therapy of iron deficiency results in free radical-mediated dysfunction of the gastrointestinal tract, it is important to verify whether the formulated requirement of nutrients meet the need of maintaining the homeostasis of free radicals. The recommended intake of vitamin E, vitamin C and other antioxidants may need to be revised so as to protect the body against oxidative stress brought about by endogenous and exogenous factors. In order to delay aging and promote health in humans of all ages, and eliminate oxidative damage in response to the treatment of certain diseases, special nutritional measures should be taken. These measures may include the control of caloric intake, reduction in the absorption of free radicals and electrophilic substances, and adequate provision of antioxidant nutrients as well as effective phytochemicals and nutraceuticals. We predict that the concept of free radical biology will continue to greatly advance life sciences, inclu
基金supported by NIH grants AR055915 and AR054465 to DC
文摘Osteoarthritis （OA） is the most common degenerative joint disease and a major cause of pain and disability in adult individuals. The etiology of OA includes joint injury, obesity, aging, and heredity. However, the detailed molecular mechanisms of OA initiation and progression remain poorly understood and, currently, there are no interventions available to restore degraded cartilage or decelerate disease progression. The diathrodial joint is a complicated organ and its function is to bear weight, perform physical activity and exhibit a joint-specific range of motion during movement. During OA development, the entire joint organ is affected, including articular cartilage, subchondral bone, synovial tissue and meniscus. A full understanding of the pathological mechanism of OA development relies on the discovery of the interplaying mechanisms among different OA symptoms, including articular cartilage degradation, osteophyte formation, subchondral sclerosis and synovial hyperplasia, and the signaling pathway（s） controlling these pathological processes.
基金the Major State Basic Research Program of China(Grant No.G1999043211) the China State Mineral Resources Investigation Program(Grant No.K14).
文摘Based on the summary of the highly precise datings of the metal deposits and related granitic rocks in North China craton and adjacent areas, such as the molybdenite Re-Os datings, 40Ar-39Ar datings of mica, K-feldspar and quartz, some Rb-Sr isochrons, and the SHRIMP zircon U-Pb dating and single grain zircon U-Pb dating, we suggest that the large-scale mineralization in North China craton and adjacent areas take place in three periods of 200-160Ma, 140Ma, and 130-110Ma. Their corresponding geodynamic settings are proposed to be the collision orogenic process, transformation of the tectonic regime, and delamination of the lithosphere, respectively, in light of analyzing the Mesozoic geodynamic evolution in the North China craton.
文摘Cancer of the pancreas remains one of the deadliest cancer types. Based on the GLOBOCAN 2012 estimates, pancreatic cancer causes more than 331000 deaths per year, ranking as the seventh leading cause of cancer death in both sexes together. Globally, about 338000 people had pancreatic cancer in 2012, making it the 11^(th) most common cancer. The highest incidence and mortality rates of pancreatic cancer are found in developed countries. Trends for pancreatic cancer incidence and mortality varied considerably in the world. A known cause of pancreatic cancer is tobacco smoking. This risk factor is likely to explain some of the international variations and gender differences. The overall five-year survival rate is about 6%(ranges from 2% to 9%), but this vary very small between developed and developing countries. To date, the causes of pancreatic cancer are still insufficiently known, although certain risk factors have been identified, such as smoking, obesity, genetics, diabetes, diet, inactivity. There are no current screening recommendations for pancreatic cancer, so primary prevention is of utmost importance. A better understanding of the etiology and identifying the risk factors is essential for the primary prevention of this disease.
文摘About 30% of patients with cirrhosis have diabetes mellitus(DM).Nowadays,it is a matter for debate whether type 2 DM in the absence of obesity and hypertriglyceridemia may be a risk factor for chronic liver disease.DM,which develops as a complication of cirrhosis,is known as "hepatogenous diabetes".Insulin resistance in muscular and adipose tissues and hyperinsulinemia seem to be the pathophysiologic bases of diabetes in liver disease.An impaired response of the islet β-cells of the pancreas and hepatic insulin resistance are also contributory factors.Non-alcoholic fatty liver disease,alcoholic cirrhosis,chronic hepatitis C(CHC) and hemochromatosis are more frequently associated with DM.Insulin resistance increases the failure of the response to treatment in patients with CHC and enhances progression of fibrosis.DM in cirrhotic patients may be subclinical.Hepatogenous diabetes is clinically different from that of type 2 DM,since it is less frequently associated with microangiopathy and patients more frequently suffer complications of cirrhosis.DM increases the mortality of cirrhotic patients.Treatment of the diabetes is complex due to liver damage and hepatotoxicity of oral hypoglycemic drugs.This manuscript will review evidence that exists in relation to:type 2 DM alone or as part of the metabolic syndrome in the development of liver disease;factors involved in the genesis of hepatogenous diabetes;the impact of DM on the clinical outcome of liver disease;the management of DM in cirrhotic patients and the role of DM as a risk factor for the occurrence and exacerbation of hepatocellular carcinoma.
基金Supported by the National Natural Science Foundation of China (Grant Nos.40472099, 40521001 and 40673019)Chinese Ministry of Education (Grant Nos.IRT0441 and 306021)
文摘Simultaneous in-situ determination of U-Pb ages and 20 trace elements of three international zircon standards(91500,GJ1 and TEMORA 1) and one laboratory zircon standard(SK10-2) separated from Cenozoic fine-grained gabbro was carried out on quadrupole ICP-MS equipped with 193 nm excimer laser in 20 μm spot size. The weighted mean 206Pb/238U ages of 91500,GJ1 and TEMORA 1 are 1064.4±4.8 Ma(2σ ),603.2±2.4 Ma(2σ ) and 418.2±2.4 Ma(2σ ),respectively. The relative standard de-viations(RSDs) of 206Pb/238U ages(2σ ) are less than 2.2% for single measurements and 0.6% for weighted means. The obtained weighted mean 206Pb/238U ages of three standard zircons agree with the recommended values within 2σ error. The weighted mean 206Pb/238U age of SK10-2 is 31.42±0.25 Ma(2σ ) and the RSDs of 206Pb/238U ages(2σ ) are between 2.4% and 5.7% for single measurements and less than 0.8% for weighted mean. The obtained weighted mean 206Pb/238U age is in good agreement with the age obtained by Yuan(2004). Trace element concentrations of NIST612 and NIST614 obtained under the same LA-ICP-MS operating conditions agree with the recommended values within analytical error. The results indicate that it is possible to measure U-Pb age and trace elements simultaneously by LA-ICP-MS in a small spot size of 20 μm.
文摘BACKGROUND: Hepatocellular carcinoma (HCC) is a major health problem worldwide. It is the fifth most common cancer in the world, and the third most common cause of cancer-related death. Without specific treatment, the prognosis is very poor. The goal of management is 'cancer control'-a reduction in its incidence and mortality as well as an improvement in the quality of life of patients with HCC and their families. This article aims to review the current management of HCC and its recent advances. DATA SOURCES: A MEDLINE database search was performed to identify relevant article using the keywords 'hepatocellular carcinoma', 'hepatectomy', 'liver transplantation', and 'local ablative therapy'. Additional papers and book chapters were identified by a manual search of the references from the key articles. RESULTS: Liver resection and liver transplantation remain the options that give the best chance of a cure. Recent evidence suggests that local ablative therapy may offer comparable survival results in patients with small HCC, and preserved liver function. Transarterial chemoembolization (TACE) is the most promising palliative modality for unresectable HCC, but other techniques, such as transarterial radioembolization (TARE), and local ablative therapy, have also shown comparable results. CONCLUSIONS: Early diagnosis of HCC remains a key goal in improving the prognosis of patients. During the last two decades, operative mortality and surgical outcome of liver resection and liver transplantation for HCC have improved. Progress also has been made in multi-modality therapy which can increase the chance of survival and improve the quality of life for patients with advanced HCC.
文摘Oxidative stress is increased in metabolic syndrome and type 2 diabetes mellitus(T2DM) and this appears to underlie the development of cardiovascular disease,T2 DM and diabetic complications.Increased oxidative stress appears to be a deleterious factor leading toinsulin resistance,dyslipidemia,β-cell dysfunction,impaired glucose tolerance and ultimately leading to T2 DM.Chronic oxidative stress,hyperglycemia and dyslipidemia are particularly dangerous for β-cells from lowest levels of antioxidant,have high oxidative energy requirements,decrease the gene expression of key β-cell genes and induce cell death.If β-cell functioning is impaired,it results in an under production of insulin,impairs glucose stimulated insulin secretion,fasting hyperglycemia and eventually the development of T2 DM.
文摘Artificial intelligence(AI)aims to mimic human cognitive functions.It is bringing a paradigm shift to healthcare,powered by increasing availability of healthcare data and rapid progress of analytics techniques.We survey the current status of AI applications in healthcare and discuss its future.AI can be applied to various types of healthcare data(structured and unstructured).Popular AI techniques include machine learning methods for structured data,such as the classical support vector machine and neural network,and the modern deep learning,as well as natural language processing for unstructured data.Major disease areas that use AI tools include cancer,neurology and cardiology.We then review in more details the AI applications in stroke,in the three major areas of early detection and diagnosis,treatment,as well as outcome prediction and prognosis evaluation.We conclude with discussion about pioneer AI systems,such as IBM Watson,and hurdles for real-life deployment of AI.
基金Supported by A Grant from the Department of Biotechnology,New Delhi, India under the 7th FP of the Indo-EU Joint Collaborative Project on "FUNCFOOD"
文摘Carcinoma of the stomach is still the second most common cause of cancer death worldwide, although the incidence and mortality have fallen dramatically over the last 50 years in many regions. The incidence of gastric cancer varies in different parts of the world and among various ethnic groups. Despite advances in diagnosis and treatment, the 5-year survival rate of stomach cancer is only 20 per cent. Stomach cancer can be classified into intestinal and diffuse types based on epidemiological and clinicopathological features. The etiology of gastric cancer is multifactorial and includes both dietary and nondietary factors. The major diet-related risk factors implicated in stomach cancer development include high content of nitrates and high salt intake. Accumulating evidence has implicated the role of Helicobacter pylori (H. pylori) infection in the pathogenesis of gastric cancer. The development of gastric cancer is a complex, multistep process involving multiple genetic and epigenetic alterations of oncogenes, tumor suppressor genes, DNA repair genes, cell cycle regulators, and signaling molecules. A plausible program for gastric cancer prevention involves intake of a balanced diet containing fruits and vegetables, improved sanitationand hygiene, screening and treatment of H. pylori infection, and follow-up of precancerous lesions. The fact that diet plays an important role in the etiology of gastric cancer offers scope for nutritional chemoprevention. Animal models have been extensively used to analyze the stepwise evolution of gastric carcinogenesis and to test dietary chemopreventive agents. Development of multitargeted preventive and therapeutic strategies for gastric cancer is a major challenge for the future.
