This review paper provides an overview of the micropillar compression technique as applied to magnesium(Mg) and its alloys. It explores the influence of various factors, such as pillar size, shape, temperature, and st...This review paper provides an overview of the micropillar compression technique as applied to magnesium(Mg) and its alloys. It explores the influence of various factors, such as pillar size, shape, temperature, and strain rate on the mechanical properties of Mg.Additionally, the impact of alloying elements, aging, and precipitates in Mg alloys has been extensively examined, revealing their significant influence on mechanical performance. The study highlights the strength and strain hardening improvements in Mg with decreasing pillar size in micropillar compression. Furthermore, the role of precipitates as strengthening agents, affecting deformation mechanisms and overall mechanical response, is explored. These valuable insights are crucial for designing Mg-based materials with enhanced mechanical properties for advanced engineering applications.展开更多
Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies ne...Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.展开更多
Selenium is a naturally occurring trace element that is nutritionally required in smallamounts but it can become toxic at concentrations only twice those required. The narrow mar-gin between beneficial and harmful lev...Selenium is a naturally occurring trace element that is nutritionally required in smallamounts but it can become toxic at concentrations only twice those required. The narrow mar-gin between beneficial and harmful levels has important implications for human activities thatincrease the amount of selenium in the environment. Two of these activities, disposal of fbssilfuel wastes and agricultural irrigation of arid, seleniferous soils, have poisoned fish andwildlife, and threatened public health at several locations in the United States. Research stud-ies of these episodes have generated a data base that clearly illustrates the environmental hazardof excessive selenium. It is strongly bioaccumulated by aquatic organisms and even slight in-creases in waterborne concentrations can quickly result in toxic effects such as deformed em-bryos and reproductive failure in wildlife. The selenium data base has been very beneficial indeveloping hazard assessment procedures and establishing environmentally sound water qualitycriteria. The two faces of selenium, required nutrient and Potent toxin, make it a particularlyimportant trace element in the health of both animals and man. Because of this paradox, envi-ronmental selenium in relation to agriculture, fisheries, and wildlife wiIl continue to raise im-POrtant land and water management issues for decades to come. If these issues are dealt withusing prudence and the available environmental selenium data base, adverse irnpacts to naturalresources andspublic health can be avoided展开更多
In the four decades from 1951 to 1990, the six provinces or autonomous regions (Xinjiang, Gansu, Qinghai, Ningxia, Xizang and Nei Monggol) reported a total of 26 065surgical cases of hydatid disease, most of which wer...In the four decades from 1951 to 1990, the six provinces or autonomous regions (Xinjiang, Gansu, Qinghai, Ningxia, Xizang and Nei Monggol) reported a total of 26 065surgical cases of hydatid disease, most of which were reported in the recent decade. About one third of the patients was children and adolescents under 15 years old. So far, cystic hydatid infections of local origin have been confirmed in 22 provinces, autonomous regions and municipalities in the whole nation. Findings of X-ray examination and real-time B-mode ultrasonography in agricultural and pastoral areas of Xinjiang, Gansu, Qinghai,Ningxia and Xizang showed that the morbidity rate of hydatidosis in human population varied between 0.5% and 4.5%. The main animal intermediate host in all these regions is sheep, the morbidity of which varied between 3.3% and 90%. The infection rate of adult Echinococcus granulosus in dogs varied between 7% and 71%. The high-risk period for humans contracting hydatid disease is the pre-school age. Direct contact of children with dogs and ingestion of water, vegetables and foods contaminated by worm eggs are the chief mode of transmission for human hydatidosis. The common practices of home slaughter and of feeding dogs on offal containing hydatid cysts facilitate the life cycIe of the parasite.On the basis of hydatid control efforts for several years, the Ministry of Public Health promulgated officially the '1992-1995 National Programme for Hydatid Disease Control'in April, 1992, and pilot studies in which the control of hydatidosis is composed of extensive health education, sanitation of slaughtering and management and deworming of dogs are being established.Cystic echinococcosis has wide distribution in China and is a major public health problem in hyperendemic areas, poses a great threat against people's health and influences the development of livestock husbandry. This problem has received great attention from the medical and veterinary departments. In the rencent decade great efforts have been made in the epidemiology, parasitology and clinical treatment of echinococcosis, resulting in a better understanding of the disease and procedures effective in bringing about control of the disease展开更多
In a world where increasing joint arthroplasties are being performed on increasingly younger patients, osteolysis as the leading cause of faiIure after total joint arthroplasty （TJA） has gained considerable attentio...In a world where increasing joint arthroplasties are being performed on increasingly younger patients, osteolysis as the leading cause of faiIure after total joint arthroplasty （TJA） has gained considerable attention. Ultra-high molecular weight polyethylene wear-induced osteolysis is the process by which prosthetic debris mechanicaIly released from the surface of prosthetic joints induces an immune response that favors bone catabolism, resulting in loosening of prostheses with eventual failure or fracture. The immune response initiated is innate in that it is nonspecific and self-propagating, with monocytic cells and osteoclasts being the main effectors. To date, detecting disease early enough to implement effective intervention without unwanted systemic side effects has been a major barrier. These barriers can be overcome using newer in vivo imaging techniques and modules linked with fluorescence and/or chemotherapies. We discuss the pathogenesis of osteolysis, and provide discussion of the challenges with imaging and therapeutics. We describe a positron emission tomography imaging cinnamoyl-Phe-（D）-Leu-Phe-（D）-Leu-Phe-Lys module, specific to maerophages, which holds promise in early detection of disease and localization of treatment. Further research and increased collaboration among therapeutic and three-dimensional imaging researchers are essential in realizing a solution to clinical osteolysis in TJA.展开更多
The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous regions...The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous regions reported the occurrence of botulism.There were 2861 cases involved in 745 outbreaks.Among the cases 421 died, with a case fatality of 14.7%.The main epidemiological characteristics of botulism in China are: (i) the major foods causing botulism are homemade fermented bean products which accounted for 62.6% of the cases; (ii) the incubation period is longer (3 h-54 days) than that described in the western literature (mostly 2-7 days); (iii) the peak occurrence is from February to May; (iv) the progression of symptoms and signs is slower than that of western cases.All types of C.bolulinum.with the exception of type G, have been found in China.The distribution of various types of C.botnlinum is significantly different between southern and northern China; this is related to the latitude and is correlated with the prevalence of this disease.Most of the botulism outbreaks occurred above 30° north latitude in northern China and outbreaks rarely occurred below 30° north latitude.Nationwide surveys showed that the average detection rate of C bolulinum spores in soil and foods in the northern parts of China was 14.8%.while it was only 2.5% in the south.C.bolulinum types A, B, E.and F, which are involved in human botulism, were frequently found in the North, while types C and D, which are involved only in animal intoxication, were found more frequently in the south. 1990 Academic Press.Inc.展开更多
Osteoporosis and consequent fracture are not limited to postmenopausal women. There is increasing attention being paid to osteoporosis in older men. Men suffer osteoporotic fractures about 10 years later in life than ...Osteoporosis and consequent fracture are not limited to postmenopausal women. There is increasing attention being paid to osteoporosis in older men. Men suffer osteoporotic fractures about 10 years later in life than women, but life expectancy is increasing faster in men than women. Thus, men are living long enough to fracture, and when they do the consequences are greater than in women, with men having about twice the 1-year fatality rate after hip fracture, compared to women. Men at high risk for fracture include those men who have already had a fragility fracture, men on oral glucocorticoids or those men being treated for prostate cancer with androgen deprivation therapy. Beyond these high risk men, there are many other risk factors and secondary causes of osteoporosis in men. Evaluation includes careful history and physical examination to reveal potential secondary causes, including many medications, a short list of laboratory tests, and bone mineral density testing by dual energy X-ray absorptiometry （DXA） of spine and hip. Recently, international organizations have advocated a single normative database for interpreting DXA testing in men and women. The consequences of this change need to be determined. There are several choices of therapy for osteoporosis in men, with most fracture reduction estimation based on studies in women.展开更多
It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, c...It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, cancer mortality rates for most cancers were found to be more than 20-fold greater in some counties in others (Table 1). Esophageal cancer rates for males are a few hundred fold greater in the highest county when compared with the lowest county. The mortality rate for all cancers combined for males is 21 fold greater in the county with the highest mortality than in the county with the lowest rate.According to Doll and Peto (1981), about one third of human cancer death is avoidable by appropriate modification of the diet. Therefore, diet is very likely to have an important part in causing these huge geographic variations. The possible role of various mutagens and carcinogens (e.g. afiatoxin, N-nitroso compounds) in locally produced and consumed foods has been strongly suggested and widely acknowledged, although much more evidence would be required to confirm their actual functions in human cancer. On the other hand, there are a few reports stating that the human diet also contains powerful antimutagens and anticarcinogens (Ames, 1983). The possible role of these two types of substances in causing the huge geographic variation of cancer risks remains elusive and inadequately explored. In order to make better use of these natural anticarcinogens in cancer prevention, it is important to elucidate their effects and mechanisms. The purpose of this paper is to summarize the available information on the antimutagenic and anticarcinogenic effects of natural foods in the Chinese diet, excluding the effects of essential nutrients, e.g. dietary fibers, vitamins and minerals. Most of the literature cited in this review was published by Chinese scientists.展开更多
Air pollution negatively impacts food security. This paper reviews the current literature on the relationship between air pollution and food security from the perspective of food system. It highlights that agricultura...Air pollution negatively impacts food security. This paper reviews the current literature on the relationship between air pollution and food security from the perspective of food system. It highlights that agricultural emissions which substantially contribute to air pollution could happen at every stage along the food supply chain. Meanwhile, air pollution can not only affect plant growth and animal health but also shift market equilibrium of both agro-inputs and outputs in the food supply chain and thereby affect food security indirectly. Furthermore, this study evaluates the effects of agricultural policy and energy policy on food security and air pollution, respectively, and provides an overview of potential policy instruments to reduce air pollution while ensuring food security. Finally, we identify the remaining research and policy issues for further studies, mainly focusing on the study of household＇s bounded rational behaviors and the issue of rural aging population.展开更多
Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge char...Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..展开更多
Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, foc...Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.展开更多
The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more dur...The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more durable than presently deployed thrusters that use electrodes such as gridded ion,Hall thrusters, arcjets and resistojets. Like other plasma thrusters, electrodeless thrusters have the advantage of reduced fuel mass compared to chemical thrusters that produce the same thrust. The status of electrodeless plasma thrusters that could be used in communications satellites and in spacecraft for interplanetary missions is examined. Electrodeless thrusters under development or planned for deployment include devices that use a rotating magnetic field; devices that use a rotating electric field; pulsed inductive devices that exploit the Lorentz force on an induced current loop in a plasma; devices that use radiofrequency fields to heat plasmas and have magnetic nozzles to accelerate the hot plasma and other devices that exploit the Lorentz force. Using metrics of specific impulse and thrust efficiency, we find that the most promising designs are those that use Lorentz forces directly to expel plasma and those that use magnetic nozzles to accelerate plasma.展开更多
Since 1957, selenium has found extensive use in livestock production to maintain an adequate selenium status in animals in areas of soil and feed/forage deficiency. Selenium may be given directly to livestock, or appl...Since 1957, selenium has found extensive use in livestock production to maintain an adequate selenium status in animals in areas of soil and feed/forage deficiency. Selenium may be given directly to livestock, or applied as a fertilizer amendment to increase selenium content of their feeds. This paper addresses the area of direct supplementation, which includes oral and parenteral supplementation, and with ruminant animals the use of slow-release boluses. Various chemical forms of selenium have been examined as supplemental sources, with sodium selenite being the earliest compound of choice. Comnbination of selenium supplementation with other livestock managernent practices led to use of selenium dioxide, which avoided solubility problems with selenite but produced effective responses. Barium salts have been used with some success as supplemental selenium sources. Experience with ruminal boluses has shown that high pressure pelleting of increased grain size selenium, in hollow pellets, has prolonged their useful life. Attention has been paid recently to residual selenium returned to the soil from livestock supplementation practices and the resulting opinion is that currently approved practices are acceptable from the point of view of environmental quality展开更多
1 SURVEY OF GLOBAL SEISMICITY A total of 17 strong earthquakes with MS≥7.0 occurred in 2016(by the end of December31,2016)throughout the world,according to the China Seismic Network.Among them,one earthquake with M_S...1 SURVEY OF GLOBAL SEISMICITY A total of 17 strong earthquakes with MS≥7.0 occurred in 2016(by the end of December31,2016)throughout the world,according to the China Seismic Network.Among them,one earthquake with M_S8.0 occurred on November 13,2016 in New Zealand(Fig.1).The 2016New Zealand M_S8.0 earthquake(M_W7.8 measured by USGS)was the strongest展开更多
Planarians can be used as invertebrate bioassays to evaluate the role of neurotransmitters on regenerating cells. The influence of the nervous system is crucial to regenerate a normal complete animal. The neurotrophic...Planarians can be used as invertebrate bioassays to evaluate the role of neurotransmitters on regenerating cells. The influence of the nervous system is crucial to regenerate a normal complete animal. The neurotrophic action of the nervous system has been attributed to the major neurohormones present throughout the animal kingdom. The same type of transmitters found in mammals have been extensively found in many invertebrates, including planarians, but their role in regeneration is unclear. Neurotransmitters and drugs which act on neurohumoral transmission have been used to determine the role of each neurohormonc on regenerating planarians. Biochemical and pharmacological mechanisms of neurohormones on regenerative planarians are reviewed, as is their putative role on regeneration. Correlations with the roles of neurotransmitters in the central nervous system of higher organisms are also addressed.展开更多
Magnetite and hematite,which are main existing forms of iron oxides in nature,could transform differently in various geological environment.Traditionally,the transformation of magnetite and
The malate(EC 1.1.1.37)and lactate(EC 1.1.1.27)dehydrogenases are themetabolic enzymes directly or indirectly involved in energy production,gluconeogenesis and lipogenesis.Malate dehydrogenase(MDH)exists in twoisoenzy...The malate(EC 1.1.1.37)and lactate(EC 1.1.1.27)dehydrogenases are themetabolic enzymes directly or indirectly involved in energy production,gluconeogenesis and lipogenesis.Malate dehydrogenase(MDH)exists in twoisoenzymic forms,cytoplasmic(cMDH)and mitochondrial(mMDH),composed of Aand/or B subunits(dimeric molecule:MW 40,000-120,000).Lactate dehydrogenase(LDH)has tetrameric(MW 35,000-110,000)structure made up of either A and/or B,orC(C,E,F)subunits.They catalyze an ordered bisubstrate(substrate and coenzyme)展开更多
Located at the easternextreme of the new Asian-European continental Bridge,the LianyungangDevelopment Zone was anarid and saline seashore tenyears ago,but today it hasbecome one of the mostdynamic opening areas inLian...Located at the easternextreme of the new Asian-European continental Bridge,the LianyungangDevelopment Zone was anarid and saline seashore tenyears ago,but today it hasbecome one of the mostdynamic opening areas inLianyungang City andJiangsu Province strewn withfactories and thoroughfares,churning out an annualindustrial output value ofRMB1.8 billion. The development zonewas approved by the StateCouncil to be established inthe Zhong Yun Dai area ofLianyungang City inDecember 1984.InSeptember of the followingyear,the city broke theground for the construction.展开更多
文摘This review paper provides an overview of the micropillar compression technique as applied to magnesium(Mg) and its alloys. It explores the influence of various factors, such as pillar size, shape, temperature, and strain rate on the mechanical properties of Mg.Additionally, the impact of alloying elements, aging, and precipitates in Mg alloys has been extensively examined, revealing their significant influence on mechanical performance. The study highlights the strength and strain hardening improvements in Mg with decreasing pillar size in micropillar compression. Furthermore, the role of precipitates as strengthening agents, affecting deformation mechanisms and overall mechanical response, is explored. These valuable insights are crucial for designing Mg-based materials with enhanced mechanical properties for advanced engineering applications.
文摘Interest in the possibility of storing and transporting natural gas in the form of clathrate hydrates has been increasing in recent years, particularly in some gas-importing and exporting countries.The technologies necessary for realizing this possibility may be classified into those relevant to the four serial processes (a) the formation of a hydrate, (b) the processing (dewatering, pelletizing, etc. ) of the formed hydrate, (c) the storage and transportation of the processed hydrate, and (d) the regasification (dissociation) of the hydrate. The technological development of any of these processes is still at an early stage. For hydrate formation, for example, various rival operations have been proposed. However,many of them have never been subjected to actual tests for practical use. More efforts are required for examining the different hydrate-formation technologies and for rating them by comparison. The general design of the processing of the formed hydrate inevitably depends on both the hydrate-formation process and the storage/transportation process, hence it has a wide variability. The major uncertainty in the storage-process design lies in the as-yet unclarified utility of the "self-preservation" effect of the naturalgas hydrates. The process design as well as the relevant cost evaluation should strongly depend on whether the hydrates are well preserved at atmospheric pressure in large-scale storage facilities. The regasification process has been studied less extensively than the former processes. The state of the art of the technological development in each of the serial processes is reviewed, placing emphasis on the hydrate formation process.
文摘Selenium is a naturally occurring trace element that is nutritionally required in smallamounts but it can become toxic at concentrations only twice those required. The narrow mar-gin between beneficial and harmful levels has important implications for human activities thatincrease the amount of selenium in the environment. Two of these activities, disposal of fbssilfuel wastes and agricultural irrigation of arid, seleniferous soils, have poisoned fish andwildlife, and threatened public health at several locations in the United States. Research stud-ies of these episodes have generated a data base that clearly illustrates the environmental hazardof excessive selenium. It is strongly bioaccumulated by aquatic organisms and even slight in-creases in waterborne concentrations can quickly result in toxic effects such as deformed em-bryos and reproductive failure in wildlife. The selenium data base has been very beneficial indeveloping hazard assessment procedures and establishing environmentally sound water qualitycriteria. The two faces of selenium, required nutrient and Potent toxin, make it a particularlyimportant trace element in the health of both animals and man. Because of this paradox, envi-ronmental selenium in relation to agriculture, fisheries, and wildlife wiIl continue to raise im-POrtant land and water management issues for decades to come. If these issues are dealt withusing prudence and the available environmental selenium data base, adverse irnpacts to naturalresources andspublic health can be avoided
文摘In the four decades from 1951 to 1990, the six provinces or autonomous regions (Xinjiang, Gansu, Qinghai, Ningxia, Xizang and Nei Monggol) reported a total of 26 065surgical cases of hydatid disease, most of which were reported in the recent decade. About one third of the patients was children and adolescents under 15 years old. So far, cystic hydatid infections of local origin have been confirmed in 22 provinces, autonomous regions and municipalities in the whole nation. Findings of X-ray examination and real-time B-mode ultrasonography in agricultural and pastoral areas of Xinjiang, Gansu, Qinghai,Ningxia and Xizang showed that the morbidity rate of hydatidosis in human population varied between 0.5% and 4.5%. The main animal intermediate host in all these regions is sheep, the morbidity of which varied between 3.3% and 90%. The infection rate of adult Echinococcus granulosus in dogs varied between 7% and 71%. The high-risk period for humans contracting hydatid disease is the pre-school age. Direct contact of children with dogs and ingestion of water, vegetables and foods contaminated by worm eggs are the chief mode of transmission for human hydatidosis. The common practices of home slaughter and of feeding dogs on offal containing hydatid cysts facilitate the life cycIe of the parasite.On the basis of hydatid control efforts for several years, the Ministry of Public Health promulgated officially the '1992-1995 National Programme for Hydatid Disease Control'in April, 1992, and pilot studies in which the control of hydatidosis is composed of extensive health education, sanitation of slaughtering and management and deworming of dogs are being established.Cystic echinococcosis has wide distribution in China and is a major public health problem in hyperendemic areas, poses a great threat against people's health and influences the development of livestock husbandry. This problem has received great attention from the medical and veterinary departments. In the rencent decade great efforts have been made in the epidemiology, parasitology and clinical treatment of echinococcosis, resulting in a better understanding of the disease and procedures effective in bringing about control of the disease
文摘In a world where increasing joint arthroplasties are being performed on increasingly younger patients, osteolysis as the leading cause of faiIure after total joint arthroplasty （TJA） has gained considerable attention. Ultra-high molecular weight polyethylene wear-induced osteolysis is the process by which prosthetic debris mechanicaIly released from the surface of prosthetic joints induces an immune response that favors bone catabolism, resulting in loosening of prostheses with eventual failure or fracture. The immune response initiated is innate in that it is nonspecific and self-propagating, with monocytic cells and osteoclasts being the main effectors. To date, detecting disease early enough to implement effective intervention without unwanted systemic side effects has been a major barrier. These barriers can be overcome using newer in vivo imaging techniques and modules linked with fluorescence and/or chemotherapies. We discuss the pathogenesis of osteolysis, and provide discussion of the challenges with imaging and therapeutics. We describe a positron emission tomography imaging cinnamoyl-Phe-（D）-Leu-Phe-（D）-Leu-Phe-Lys module, specific to maerophages, which holds promise in early detection of disease and localization of treatment. Further research and increased collaboration among therapeutic and three-dimensional imaging researchers are essential in realizing a solution to clinical osteolysis in TJA.
文摘The epidemiological characteristics and etiology of botulisin in China, as well as the distribution of different types of Clustridium bolulinum in China; are described.Through 1989, 15 provinces and autonomous regions reported the occurrence of botulism.There were 2861 cases involved in 745 outbreaks.Among the cases 421 died, with a case fatality of 14.7%.The main epidemiological characteristics of botulism in China are: (i) the major foods causing botulism are homemade fermented bean products which accounted for 62.6% of the cases; (ii) the incubation period is longer (3 h-54 days) than that described in the western literature (mostly 2-7 days); (iii) the peak occurrence is from February to May; (iv) the progression of symptoms and signs is slower than that of western cases.All types of C.bolulinum.with the exception of type G, have been found in China.The distribution of various types of C.botnlinum is significantly different between southern and northern China; this is related to the latitude and is correlated with the prevalence of this disease.Most of the botulism outbreaks occurred above 30° north latitude in northern China and outbreaks rarely occurred below 30° north latitude.Nationwide surveys showed that the average detection rate of C bolulinum spores in soil and foods in the northern parts of China was 14.8%.while it was only 2.5% in the south.C.bolulinum types A, B, E.and F, which are involved in human botulism, were frequently found in the North, while types C and D, which are involved only in animal intoxication, were found more frequently in the south. 1990 Academic Press.Inc.
文摘Osteoporosis and consequent fracture are not limited to postmenopausal women. There is increasing attention being paid to osteoporosis in older men. Men suffer osteoporotic fractures about 10 years later in life than women, but life expectancy is increasing faster in men than women. Thus, men are living long enough to fracture, and when they do the consequences are greater than in women, with men having about twice the 1-year fatality rate after hip fracture, compared to women. Men at high risk for fracture include those men who have already had a fragility fracture, men on oral glucocorticoids or those men being treated for prostate cancer with androgen deprivation therapy. Beyond these high risk men, there are many other risk factors and secondary causes of osteoporosis in men. Evaluation includes careful history and physical examination to reveal potential secondary causes, including many medications, a short list of laboratory tests, and bone mineral density testing by dual energy X-ray absorptiometry （DXA） of spine and hip. Recently, international organizations have advocated a single normative database for interpreting DXA testing in men and women. The consequences of this change need to be determined. There are several choices of therapy for osteoporosis in men, with most fracture reduction estimation based on studies in women.
文摘It is well known that there are huge geographic variations in cancer rates in China's Mainland. For example, The National Cancer Control Office of the Ministry of Public Health (1979) reported that in the 1970s, cancer mortality rates for most cancers were found to be more than 20-fold greater in some counties in others (Table 1). Esophageal cancer rates for males are a few hundred fold greater in the highest county when compared with the lowest county. The mortality rate for all cancers combined for males is 21 fold greater in the county with the highest mortality than in the county with the lowest rate.According to Doll and Peto (1981), about one third of human cancer death is avoidable by appropriate modification of the diet. Therefore, diet is very likely to have an important part in causing these huge geographic variations. The possible role of various mutagens and carcinogens (e.g. afiatoxin, N-nitroso compounds) in locally produced and consumed foods has been strongly suggested and widely acknowledged, although much more evidence would be required to confirm their actual functions in human cancer. On the other hand, there are a few reports stating that the human diet also contains powerful antimutagens and anticarcinogens (Ames, 1983). The possible role of these two types of substances in causing the huge geographic variation of cancer risks remains elusive and inadequately explored. In order to make better use of these natural anticarcinogens in cancer prevention, it is important to elucidate their effects and mechanisms. The purpose of this paper is to summarize the available information on the antimutagenic and anticarcinogenic effects of natural foods in the Chinese diet, excluding the effects of essential nutrients, e.g. dietary fibers, vitamins and minerals. Most of the literature cited in this review was published by Chinese scientists.
基金funding supports from the National Natural Science Foundation of China (NSFC, 71473123 and 71633005)the German Research Foundation (DFG, RTG1666)
文摘Air pollution negatively impacts food security. This paper reviews the current literature on the relationship between air pollution and food security from the perspective of food system. It highlights that agricultural emissions which substantially contribute to air pollution could happen at every stage along the food supply chain. Meanwhile, air pollution can not only affect plant growth and animal health but also shift market equilibrium of both agro-inputs and outputs in the food supply chain and thereby affect food security indirectly. Furthermore, this study evaluates the effects of agricultural policy and energy policy on food security and air pollution, respectively, and provides an overview of potential policy instruments to reduce air pollution while ensuring food security. Finally, we identify the remaining research and policy issues for further studies, mainly focusing on the study of household＇s bounded rational behaviors and the issue of rural aging population.
文摘Chemical effects in different aqueous solutions induced by plasma with glow discharge electrolysis (GDE) and contact glow discharge electrolysis (CGDE) are described in this paper. The experimental and discharge characteristics are also reviewed. These are followed by a discussion of their mechanisms of both anodic and cathodic CGDE..
基金supported by the startup funding provided by HUST
文摘Accurately modeling nonlinear interactions in turbulence is one of the key challenges for large-eddy simulation（LES） of turbulence. In this article, we review recent studies on structural subgrid scale modeling, focusing on evaluating how well these models predict the effects of small scales. The article discusses a priori and a posteriori test results. Other nonlinear models are briefly discussed, and future prospects are noted.
基金The financial support of the Australian Research Council for this projectthe provision of an Australian Postgraduate Award
文摘The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more durable than presently deployed thrusters that use electrodes such as gridded ion,Hall thrusters, arcjets and resistojets. Like other plasma thrusters, electrodeless thrusters have the advantage of reduced fuel mass compared to chemical thrusters that produce the same thrust. The status of electrodeless plasma thrusters that could be used in communications satellites and in spacecraft for interplanetary missions is examined. Electrodeless thrusters under development or planned for deployment include devices that use a rotating magnetic field; devices that use a rotating electric field; pulsed inductive devices that exploit the Lorentz force on an induced current loop in a plasma; devices that use radiofrequency fields to heat plasmas and have magnetic nozzles to accelerate the hot plasma and other devices that exploit the Lorentz force. Using metrics of specific impulse and thrust efficiency, we find that the most promising designs are those that use Lorentz forces directly to expel plasma and those that use magnetic nozzles to accelerate plasma.
文摘Since 1957, selenium has found extensive use in livestock production to maintain an adequate selenium status in animals in areas of soil and feed/forage deficiency. Selenium may be given directly to livestock, or applied as a fertilizer amendment to increase selenium content of their feeds. This paper addresses the area of direct supplementation, which includes oral and parenteral supplementation, and with ruminant animals the use of slow-release boluses. Various chemical forms of selenium have been examined as supplemental sources, with sodium selenite being the earliest compound of choice. Comnbination of selenium supplementation with other livestock managernent practices led to use of selenium dioxide, which avoided solubility problems with selenite but produced effective responses. Barium salts have been used with some success as supplemental selenium sources. Experience with ruminal boluses has shown that high pressure pelleting of increased grain size selenium, in hollow pellets, has prolonged their useful life. Attention has been paid recently to residual selenium returned to the soil from livestock supplementation practices and the resulting opinion is that currently approved practices are acceptable from the point of view of environmental quality
基金sponsored by the National Natural Science Foundation of China(41504047)the National Sichuan-Yunnan Earthquake Monitoring and Prediction Site Program of China(2016CESE0101) the 2016 Youth Fund of Earthquake Situation Tracking Work,CEA (2016010109)
文摘1 SURVEY OF GLOBAL SEISMICITY A total of 17 strong earthquakes with MS≥7.0 occurred in 2016(by the end of December31,2016)throughout the world,according to the China Seismic Network.Among them,one earthquake with M_S8.0 occurred on November 13,2016 in New Zealand(Fig.1).The 2016New Zealand M_S8.0 earthquake(M_W7.8 measured by USGS)was the strongest
文摘Planarians can be used as invertebrate bioassays to evaluate the role of neurotransmitters on regenerating cells. The influence of the nervous system is crucial to regenerate a normal complete animal. The neurotrophic action of the nervous system has been attributed to the major neurohormones present throughout the animal kingdom. The same type of transmitters found in mammals have been extensively found in many invertebrates, including planarians, but their role in regeneration is unclear. Neurotransmitters and drugs which act on neurohumoral transmission have been used to determine the role of each neurohormonc on regenerating planarians. Biochemical and pharmacological mechanisms of neurohormones on regenerative planarians are reviewed, as is their putative role on regeneration. Correlations with the roles of neurotransmitters in the central nervous system of higher organisms are also addressed.
文摘Magnetite and hematite,which are main existing forms of iron oxides in nature,could transform differently in various geological environment.Traditionally,the transformation of magnetite and
文摘The malate(EC 1.1.1.37)and lactate(EC 1.1.1.27)dehydrogenases are themetabolic enzymes directly or indirectly involved in energy production,gluconeogenesis and lipogenesis.Malate dehydrogenase(MDH)exists in twoisoenzymic forms,cytoplasmic(cMDH)and mitochondrial(mMDH),composed of Aand/or B subunits(dimeric molecule:MW 40,000-120,000).Lactate dehydrogenase(LDH)has tetrameric(MW 35,000-110,000)structure made up of either A and/or B,orC(C,E,F)subunits.They catalyze an ordered bisubstrate(substrate and coenzyme)
文摘Located at the easternextreme of the new Asian-European continental Bridge,the LianyungangDevelopment Zone was anarid and saline seashore tenyears ago,but today it hasbecome one of the mostdynamic opening areas inLianyungang City andJiangsu Province strewn withfactories and thoroughfares,churning out an annualindustrial output value ofRMB1.8 billion. The development zonewas approved by the StateCouncil to be established inthe Zhong Yun Dai area ofLianyungang City inDecember 1984.InSeptember of the followingyear,the city broke theground for the construction.
