Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research an...Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research and development（R D） alliances.Therefore,the first objective of this study is to investigate why there exist different organizational governance structures in managing R D alliances;the second objective of this study is to give strategic advice in choosing appropriate forms with respect to various characteristics of R D alliances.Through the theoretical lens that integrate both transaction cost economics（TCE） and the resource-based view（RBV）,a model that focuses on six major factors is developed for determining governance structure choices,namely,technological uncertainty,cultural difference,asset specificity,technology complementarity,appropriability of the individual firm＇s know-how,and trust.An R D alliance with higher technological uncertainty,larger cultural differences,and greater concerns for protecting an individual＇s know-how is more likely to adopt non-integrated alliances as the governing structure.An R D alliance with a higher degree of asset-specificity,greater technology complementarity and greater trust among partnering organizations is more likely to adopt integrated alliances as the governing structure;an R D alliance in the face of lower technological uncertainty will tend to adopt integrated alliances.The more aligned the choice of the governance structure with its determinants,the better the R D alliance will perform,and vice versa.展开更多
Herbal products are increasingly used, mainly in chronic liver disease. Extracts of milk thistle, Silymarin and silybin, are the most prescribed natural compounds, with different indications, but with no definitive re...Herbal products are increasingly used, mainly in chronic liver disease. Extracts of milk thistle, Silymarin and silybin, are the most prescribed natural compounds, with different indications, but with no definitive results in terms of clinical efficacy. This review analyzes the available studies on the effects of the purified product silybin, both as a free and a conjugated molecule, on liver cells or on experimentally induced liver damage, and in patients with liver disease. We searched PUBMED for articles pertaining to the in vitro and in vivo effects of silybin, its antifibrotic, anti-inflammatory, and antioxidant properties, as well as its metabolic effects, combined with the authors’ own knowledge of the literature. Results indicate that the bioavailability of silybin phytosome is higher than that of silymarin and is less influenced by liver damage; silybin does not show significant interactions with other drugs and at doses < 10 g/d has no significant side effects. Experimental studies have clearly demonstrated the antifibrotic, antioxidant and metabolic effects of silybin; previous human studies were insufficient for confirming the clinical efficacy in chronic liver disease, while ongoing clinical trials are promising. On the basis of literature data, silybin seems a promising drug for chronic liver disease.展开更多
There have been some breakthroughs in the diagnosis and treatment of esophageal achalasia in the past few years.First,the introduction of high-resolution manometry with pressure topography plotting as a new diagnostic...There have been some breakthroughs in the diagnosis and treatment of esophageal achalasia in the past few years.First,the introduction of high-resolution manometry with pressure topography plotting as a new diagnostic tool has made it possible to classify achalasia into three subtypes.The most favorable outcome is predicted for patients receiving treatment for type Ⅱ achalasia (achalasia with compression).Patients with typeⅠ(classic achalasia) and type Ⅲ achalasia (spastic achalasia) experience a less favorable outcome.Second,the first multicenter randomized controlled trial published by the European Achalasia Trial group reported 2-year follow-up results indicating that laparoscopic Heller myotomy was not superior to endoscopic pneumatic dilation (PD).Although the follow-up period was not long enough to reach a convincing conclusion,it merits the continued use of PD as a generally available technique in gastroenterology.Third,the novelendoscopic technique peroral endoscopic myotomy is a promising option for treating achalasia,but it requires increased experience and cautious evaluation.Despite all this good news,the bottom line is a real break-through from the basic studies to identify the actual cause of achalasia that may impede treatment success is still anticipated.展开更多
It is of great significance to study gas hydrate because of following reasons. （1） Most organic carbon in the earth reserves in the form of natural gas hydrate, which is considered as a potential energy resource for...It is of great significance to study gas hydrate because of following reasons. （1） Most organic carbon in the earth reserves in the form of natural gas hydrate, which is considered as a potential energy resource for the survival of human being in the future. （2） A series of novel technologies are based on gas hydrate. （3） Gas hydrate may lead to many hazards including plugging of oil/gas pipelines, accelerating global warming up, etc. In this paper, the latest progresses in exploration and exploitation of natural gas hydrate, the development of hydrate-based technologies including gas separation, gas storage, CO2 sequestration via forming hydrate, as well as the prevention of hydrate hazards are reviewed. Additionally, the progresses in the fundamental study of gas hydrate, including the thermodynamics and kinetics are also reviewed. A prospect to the future of gas hydrate research and application is given.展开更多
There are four steps in the interaction between intestinal microbes and mucosal inflammation in genetically predisposed individuals from the viewpoints of basic and clinical aspects of inflammatory bowel disease （IBD...There are four steps in the interaction between intestinal microbes and mucosal inflammation in genetically predisposed individuals from the viewpoints of basic and clinical aspects of inflammatory bowel disease （IBD）. The first step is an interaction between intestinal microbes or their components and intestinal epithelial cells via receptors, the second step an interaction between macrophages and dendritic cells and mucosal lymphocytes, the third step an interaction between lymphocytes and vascular endothelial cells, and the fourth step an interaction between lymphocytes and granulocytes producing proinflammatory cytokines or free radicals and mucosal damage and repair. Recent therapeutic approaches for IBD aim to block these four steps in the intestinal inflammation of patients with IBD.展开更多
Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of fe...Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of feeding and facility of operating make the tree shrew an ideal non-human primate model proxy. Additional features like vulnerability to stress and spontaneous diabetic characteristics also indicate that the tree shrew could be a potential new animal model of human diseases. However, basal physiological indexes of tree shrew, especially those related to human disease, have not been systematically reported. Accordingly, we established important basal physiological indexes of domesticated tree shrews including several factors: (1) body weight, (2) core body temperature and rhythm, (3) diet metabolism, (4) locomotor rhythm, (5) electroencephalogram, (6) glycometabolism and (7) serum and urinary hormone level and urinary cortisol rhythm. We compared the physiological parameters of domesticated tree shrew with that of rats and macaques. Results showed that (a) the core body temperature of the tree shrew was 39.59±0.05 °C, which was higher than that of rats and macaques; (b) Compared with wild tree shrews, with two activity peaks, domesticated tree shrews had only one activity peak from 17:30 to 19:30; (c) Compared with rats, tree shrews had poor carbohydrate metabolism ability; and (d) Urinary cortisol rhythm indicated there were two peaks at 8:00 and 17:00 in domesticated tree shrews, which matched activity peaks in wild tree shrews. These results provided basal physiological indexes for domesticated tree shrews and laid an important foundation for diabetes and stress-related disease models established on tree shrews.展开更多
Climate change has advanced the phenology of many organisms. Migratory animals face particular problems because climate change in the breeding and the wintering range may be asynchronous, preventing rapid response to ...Climate change has advanced the phenology of many organisms. Migratory animals face particular problems because climate change in the breeding and the wintering range may be asynchronous, preventing rapid response to changing conditions. Advancement in timing of spring migration may have carry-over effects to other parts of the annual cycle, simply because advancement of one event in the annual cycle also advances subsequent events, gradually causing a general shift in the timing of the entire annual cycle. Such a phenotypic shift could generate accumulating effects over the years for individuals, but also across generations. Here we test this novel hypothesis of phenotypic response to climate change by using long-term data on the Arctic tern Sterna paradisaea. Mean breeding date advanced by almost three weeks during the last 70 years. Annual arrival date at the breeding grounds during a period of 47 years was predicted by environmental conditions in the winter quarters in the Southern Ocean near the Antarctic and by mean breeding date the previous year. Annual mean breeding date was only marginally determined by timing of arrival the current year, but to a larger extent by arrival date and breeding date the previous year. Learning affected arrival date as shown by a positive correlation between arrival date in year （i ＋ 1） relative to breeding date in year （i） and the selective advantage of early breeding in year （i）. This provides a mechanism for changes in arrival date being adjusted to changing environmental conditions. This study suggests that adaptation to changing climatic conditions can be achieved through learning from year to year展开更多
This paper introduces the research progress on the cognition flow in the National Basic Research Program of China(973 Program)under Grant No. 2009CB320400 "Research on Basic Theories and Key Technologies of Cogni...This paper introduces the research progress on the cognition flow in the National Basic Research Program of China(973 Program)under Grant No. 2009CB320400 "Research on Basic Theories and Key Technologies of Cognitive Radio Networks". We present the motivation behind the proposal of the concept of cognition flow, provide the definition, discuss the features, behaviours, representations, mathematical models, and the functions of cognition flow in Cognitive Radio Networks(CRNs). We also analyse how the cognition flow promotes the convergence of heterogeneous networks.Our group also constructed the test platform to verify the usefulness of cognition flow. The results that were simulated by computers and tested on the platform both confirm that cognition flow can realise efficient interaction of cognitive information among heterogeneous networks in CRNs, which contributes to the seamless convergence of heterogeneous networks,and significantly improves the spectrum efficiency and users' Quality of Experience(QoE).展开更多
Aiming to make a high power direct current supply safely used in coal mine production, this paper made a deep research on characteristics of intrinsically safe power supply, using the mathematical model established ac...Aiming to make a high power direct current supply safely used in coal mine production, this paper made a deep research on characteristics of intrinsically safe power supply, using the mathematical model established according to coal mine intrinsic safety standards. It provides theory support for the application of high power intrinsically safe power supply. The released energy of output short circuit of switch power supply, and the close related factors that influence the biggest output short-circuit spark discharge energy are the theoretical basis of the power supply. It is shown how to make a high power intrinsically safe power supply using the calculated values in the mathematical model, and take values from intrinsically safe requirements parameters scope, then this theoretical calculation value can be developed as the ultimate basis for research of the power supply. It gets the identification method of intrinsically safe from mathematics model of intrinsically safe power supply characteristics study, which solves the problem of theory and application of designing different power intrinsically safe power supply, and designs a kind of high power intrinsically safe power supply through this method. energy, flyback展开更多
基金The Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Traditionally governance structures are classified into ＂hierarchy or market＂ or ＂equity or non-equity.＂ However,such classifications may not be effective in characterizing all governance structures of research and development（R D） alliances.Therefore,the first objective of this study is to investigate why there exist different organizational governance structures in managing R D alliances;the second objective of this study is to give strategic advice in choosing appropriate forms with respect to various characteristics of R D alliances.Through the theoretical lens that integrate both transaction cost economics（TCE） and the resource-based view（RBV）,a model that focuses on six major factors is developed for determining governance structure choices,namely,technological uncertainty,cultural difference,asset specificity,technology complementarity,appropriability of the individual firm＇s know-how,and trust.An R D alliance with higher technological uncertainty,larger cultural differences,and greater concerns for protecting an individual＇s know-how is more likely to adopt non-integrated alliances as the governing structure.An R D alliance with a higher degree of asset-specificity,greater technology complementarity and greater trust among partnering organizations is more likely to adopt integrated alliances as the governing structure;an R D alliance in the face of lower technological uncertainty will tend to adopt integrated alliances.The more aligned the choice of the governance structure with its determinants,the better the R D alliance will perform,and vice versa.
文摘Herbal products are increasingly used, mainly in chronic liver disease. Extracts of milk thistle, Silymarin and silybin, are the most prescribed natural compounds, with different indications, but with no definitive results in terms of clinical efficacy. This review analyzes the available studies on the effects of the purified product silybin, both as a free and a conjugated molecule, on liver cells or on experimentally induced liver damage, and in patients with liver disease. We searched PUBMED for articles pertaining to the in vitro and in vivo effects of silybin, its antifibrotic, anti-inflammatory, and antioxidant properties, as well as its metabolic effects, combined with the authors’ own knowledge of the literature. Results indicate that the bioavailability of silybin phytosome is higher than that of silymarin and is less influenced by liver damage; silybin does not show significant interactions with other drugs and at doses < 10 g/d has no significant side effects. Experimental studies have clearly demonstrated the antifibrotic, antioxidant and metabolic effects of silybin; previous human studies were insufficient for confirming the clinical efficacy in chronic liver disease, while ongoing clinical trials are promising. On the basis of literature data, silybin seems a promising drug for chronic liver disease.
文摘There have been some breakthroughs in the diagnosis and treatment of esophageal achalasia in the past few years.First,the introduction of high-resolution manometry with pressure topography plotting as a new diagnostic tool has made it possible to classify achalasia into three subtypes.The most favorable outcome is predicted for patients receiving treatment for type Ⅱ achalasia (achalasia with compression).Patients with typeⅠ(classic achalasia) and type Ⅲ achalasia (spastic achalasia) experience a less favorable outcome.Second,the first multicenter randomized controlled trial published by the European Achalasia Trial group reported 2-year follow-up results indicating that laparoscopic Heller myotomy was not superior to endoscopic pneumatic dilation (PD).Although the follow-up period was not long enough to reach a convincing conclusion,it merits the continued use of PD as a generally available technique in gastroenterology.Third,the novelendoscopic technique peroral endoscopic myotomy is a promising option for treating achalasia,but it requires increased experience and cautious evaluation.Despite all this good news,the bottom line is a real break-through from the basic studies to identify the actual cause of achalasia that may impede treatment success is still anticipated.
基金Supported by the National Natural Science Foundation of China （20925623 21076225） the National High Technology Research and Development Program of China （2007AA09Z311）+1 种基金 the National Science ＆ Technology Major Project （2008ZX05026-004-03） the National Basic Research Program of China （2009CB219504）
文摘It is of great significance to study gas hydrate because of following reasons. （1） Most organic carbon in the earth reserves in the form of natural gas hydrate, which is considered as a potential energy resource for the survival of human being in the future. （2） A series of novel technologies are based on gas hydrate. （3） Gas hydrate may lead to many hazards including plugging of oil/gas pipelines, accelerating global warming up, etc. In this paper, the latest progresses in exploration and exploitation of natural gas hydrate, the development of hydrate-based technologies including gas separation, gas storage, CO2 sequestration via forming hydrate, as well as the prevention of hydrate hazards are reviewed. Additionally, the progresses in the fundamental study of gas hydrate, including the thermodynamics and kinetics are also reviewed. A prospect to the future of gas hydrate research and application is given.
文摘There are four steps in the interaction between intestinal microbes and mucosal inflammation in genetically predisposed individuals from the viewpoints of basic and clinical aspects of inflammatory bowel disease （IBD）. The first step is an interaction between intestinal microbes or their components and intestinal epithelial cells via receptors, the second step an interaction between macrophages and dendritic cells and mucosal lymphocytes, the third step an interaction between lymphocytes and vascular endothelial cells, and the fourth step an interaction between lymphocytes and granulocytes producing proinflammatory cytokines or free radicals and mucosal damage and repair. Recent therapeutic approaches for IBD aim to block these four steps in the intestinal inflammation of patients with IBD.
基金supported by grants from the Chinese Academy of Sciences (KSCX2-EW-R-12, KSCX2-EW-J-23)the National Natural Science Foundation of China (81171294)Shanghai Science & Technology Development Foundation(12140904200)
文摘Establishing non-human primate models of human diseases is an efficient way to narrow the large gap between basic studies and translational medicine. Multifold advantages such as simplicity of breeding, low cost of feeding and facility of operating make the tree shrew an ideal non-human primate model proxy. Additional features like vulnerability to stress and spontaneous diabetic characteristics also indicate that the tree shrew could be a potential new animal model of human diseases. However, basal physiological indexes of tree shrew, especially those related to human disease, have not been systematically reported. Accordingly, we established important basal physiological indexes of domesticated tree shrews including several factors: (1) body weight, (2) core body temperature and rhythm, (3) diet metabolism, (4) locomotor rhythm, (5) electroencephalogram, (6) glycometabolism and (7) serum and urinary hormone level and urinary cortisol rhythm. We compared the physiological parameters of domesticated tree shrew with that of rats and macaques. Results showed that (a) the core body temperature of the tree shrew was 39.59±0.05 °C, which was higher than that of rats and macaques; (b) Compared with wild tree shrews, with two activity peaks, domesticated tree shrews had only one activity peak from 17:30 to 19:30; (c) Compared with rats, tree shrews had poor carbohydrate metabolism ability; and (d) Urinary cortisol rhythm indicated there were two peaks at 8:00 and 17:00 in domesticated tree shrews, which matched activity peaks in wild tree shrews. These results provided basal physiological indexes for domesticated tree shrews and laid an important foundation for diabetes and stress-related disease models established on tree shrews.
文摘Climate change has advanced the phenology of many organisms. Migratory animals face particular problems because climate change in the breeding and the wintering range may be asynchronous, preventing rapid response to changing conditions. Advancement in timing of spring migration may have carry-over effects to other parts of the annual cycle, simply because advancement of one event in the annual cycle also advances subsequent events, gradually causing a general shift in the timing of the entire annual cycle. Such a phenotypic shift could generate accumulating effects over the years for individuals, but also across generations. Here we test this novel hypothesis of phenotypic response to climate change by using long-term data on the Arctic tern Sterna paradisaea. Mean breeding date advanced by almost three weeks during the last 70 years. Annual arrival date at the breeding grounds during a period of 47 years was predicted by environmental conditions in the winter quarters in the Southern Ocean near the Antarctic and by mean breeding date the previous year. Annual mean breeding date was only marginally determined by timing of arrival the current year, but to a larger extent by arrival date and breeding date the previous year. Learning affected arrival date as shown by a positive correlation between arrival date in year （i ＋ 1） relative to breeding date in year （i） and the selective advantage of early breeding in year （i）. This provides a mechanism for changes in arrival date being adjusted to changing environmental conditions. This study suggests that adaptation to changing climatic conditions can be achieved through learning from year to year
基金supported by the National Basic Research Program of China(973 Program)under Grant No.2009CB320400the National Natural Science Foundation of China under Grants No.61101117,No.61171099+2 种基金the National Key Scientific and Technological Project of China under Grant No,2012ZX03003-007the Natural Science Foundation of Jiangxi under Grant No.20132BAB201018the Fundamental Research Funds for the Central Universities under Grant No.BUPT2012RC0112
文摘This paper introduces the research progress on the cognition flow in the National Basic Research Program of China(973 Program)under Grant No. 2009CB320400 "Research on Basic Theories and Key Technologies of Cognitive Radio Networks". We present the motivation behind the proposal of the concept of cognition flow, provide the definition, discuss the features, behaviours, representations, mathematical models, and the functions of cognition flow in Cognitive Radio Networks(CRNs). We also analyse how the cognition flow promotes the convergence of heterogeneous networks.Our group also constructed the test platform to verify the usefulness of cognition flow. The results that were simulated by computers and tested on the platform both confirm that cognition flow can realise efficient interaction of cognitive information among heterogeneous networks in CRNs, which contributes to the seamless convergence of heterogeneous networks,and significantly improves the spectrum efficiency and users' Quality of Experience(QoE).
文摘Aiming to make a high power direct current supply safely used in coal mine production, this paper made a deep research on characteristics of intrinsically safe power supply, using the mathematical model established according to coal mine intrinsic safety standards. It provides theory support for the application of high power intrinsically safe power supply. The released energy of output short circuit of switch power supply, and the close related factors that influence the biggest output short-circuit spark discharge energy are the theoretical basis of the power supply. It is shown how to make a high power intrinsically safe power supply using the calculated values in the mathematical model, and take values from intrinsically safe requirements parameters scope, then this theoretical calculation value can be developed as the ultimate basis for research of the power supply. It gets the identification method of intrinsically safe from mathematics model of intrinsically safe power supply characteristics study, which solves the problem of theory and application of designing different power intrinsically safe power supply, and designs a kind of high power intrinsically safe power supply through this method. energy, flyback
