A new safety assessment method for parallel routes is presented. From the aspects of safety guard system of air traffic control(ATC) and considering the flight conflict as causing event of air collision accidents, t...A new safety assessment method for parallel routes is presented. From the aspects of safety guard system of air traffic control(ATC) and considering the flight conflict as causing event of air collision accidents, this paper fosters a four-layer safety guard of controller command, short-term conflict alerts (STCAs), pilot visual avoidance, and traffic alert collision avoidance system(TCAS). Then, the problem of parallel routes collision risk is divided into two parts:the calculation of potential flight conflict and the analysis of failure probability of the four-layer safety guard. A calculation model for controller interference times is induced. By using cognitive reliability and error analysis method(CREAM),the calculation problem to failure probability of controller sequencing flight conflicts is solved and a fault tree model of guard failure of STCA and TCAS is established. Finally, the Beijing-Shanghai parallel routes are taken as an example to be calculated and the collision risk of the parallel routes is obtained under the condition of radar control. Results show that the parallel routes can satisfy the safety demands.展开更多
An assessment index system including environment, socio-culture, economy and technology was established for evaluating environmental construction level of community (objective construction), and questionnaire was de...An assessment index system including environment, socio-culture, economy and technology was established for evaluating environmental construction level of community (objective construction), and questionnaire was designed according to paper review for evaluating residential satisfaction (subjective satisfaction). The index system was divided into four layers: system (A), subsystems (B), categories (C), and indicators (D), and in total of 38 indicators was established. The Xihe community, affiliated to Nanfen district, Benxi City, Liaoning Province, China was selected as a case study. Results indicated that the community sustainability index related to objective environmental construction was 0.4355 and was classified as class Ⅲ (moderate); the community sustainability index related to the residential satisfaction was 0.4255, belonging to class Ⅲ. In conclusion, the sustainability of Xihe community was moderate and needed to be improved. Residential satisfaction was lower than objective environmental construction. The assessment index system established in this study is able to reflect the comprehensive sustainability of community and can be used to evaluate other similar communities' sustainability.展开更多
The veracity of land evaluation is tightly related to the reasonable weights of land evaluation fac- tors. By mapping qualitative linguistic words into a fine-changeable cloud drops and translating the uncertain facto...The veracity of land evaluation is tightly related to the reasonable weights of land evaluation fac- tors. By mapping qualitative linguistic words into a fine-changeable cloud drops and translating the uncertain factor conditions into quantitative values with the uncertain illation based on cloud model, and then, inte- grating correlation analysis, a new way of figuring out the weight of land evaluation factors is proposed. It may solve the limitations of the conventional ways.展开更多
Background This prospective study integrated multiple clinical indexes and inflammatory markers associated with coronary atherosclerotic vulnerable plaque to establish a risk prediction model that can evaluate a patie...Background This prospective study integrated multiple clinical indexes and inflammatory markers associated with coronary atherosclerotic vulnerable plaque to establish a risk prediction model that can evaluate a patient with certain risk factors for the likelihood of the occurrence of a coronary heart disease event within one year. Methods This study enrolled in 2686 patients with mild to moderate coronary artery lesions. Eighty-five indexes were recorded, included baseline clinical data, laboratory studies, and procedural characteristics. During the 1-year follow-up, 233 events occurred, five patients died, four patients suffered a nonfatal myocardial infarction, four patients underwent revascularization, and 220 patients were readmitted for angina pectoris. The Risk Estimation Model and the Simplified Model were conducted using Bayesian networks and compared with the Single Factor Models. Results The area under the curve was 0.88 for the Bayesian Model and 0.85 for the Simplified Model, while the Single Factor Model had a maximum area under the curve of 0.65. Conclusion The new models can be used to assess the short-term risk of individual coronary heart disease events and may assist in guiding preventive care.展开更多
In recent years,the immune-modulatory role of all-trans astaxanthin from different pigment sources has been studied.It was reported that all-trans astaxanthin might exist as three stereoisomers,and the composition of ...In recent years,the immune-modulatory role of all-trans astaxanthin from different pigment sources has been studied.It was reported that all-trans astaxanthin might exist as three stereoisomers,and the composition of all-trans stereoisomers in natural materials differs from that of synthetic products.However,the different biological effects of various all-trans stereoisomers still remain unclear.In the present study,we evaluated the bioactivity of three astaxanthin stereoisomers,(3S,3'S)-trans-,(3R,3'R)-transand meso-trans-astaxanthin,in regulating cell-mediated immune response using mice lymphocytes and peritoneal exudates cells(PECs) systems.After the treatment with three astaxanthin stereoisomers(20 μmol L-1),the lymphocyte proliferation capacity,neutral red phagocytosis of PECs and natural killer(NK) cell cytotoxic activity were comparatively assessed.The results showed that all three astaxanthin stereoisomers significantly promoted lymphocyte proliferation,phagocytic capacity of PECs,and cytotoxic activity of NK cells.Moreover,the(3S,3'S)-trans-astaxanthin exhibited a much higher response than others.展开更多
The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors (more in general determ...The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors (more in general determinants or risk factors). However, when the follow-up period is very long and Kaplan-Meier survival curves are adopted, or Kaplan- Meier-based more complex models such as Cox's analysis are used, clinical (or epidemiological) reality may well be distorted since by these survival methods risks tend to be overestimated, whereas survival tends to be reduced.展开更多
Objective: Cancer is one of the most common diagnoses in elderly patients. Of all types of abdominal cancer, colorectal cancer(CRC) is undoubtedly the most frequent. Median age at diagnosis is approximately 70 years o...Objective: Cancer is one of the most common diagnoses in elderly patients. Of all types of abdominal cancer, colorectal cancer(CRC) is undoubtedly the most frequent. Median age at diagnosis is approximately 70 years old worldwide. Due to the multiple comorbidities affecting elderly people, frailty evaluation is very important in order to avoid over- or undertreatment. This pilot study was designed to investigate the variables capable of predicting the long-term risk of mortality and living situation after surgery for CRC.Methods: Patients with 70 years old and older undergoing elective surgery for CRC were prospectively enrolled in the study. The patients were preoperatively screened using 11 internationally-validated-frailty-assessment tests. The endpoints of the study were long-term mortality and living situation. The data were analyzed using univariate Cox proportional-hazard regression analysis to verify the predictive value of score indices in order to identify possible risk factors.Results: Forty-six patients were studied. The median follow-up time after surgery was 4.6 years(range, 2.9-5.7 years) and no patients were lost to follow-up. The overall mortality rate was 39%. Four of the patients who survived(4/28, 14%) lost their functional autonomy. The preoperative impaired Timed Up and Go(TUG), Eastern Cooperative Group Performance Status(ECOG PS), Instrumental Activities of Daily Living(IADLs), Vulnerable Elders Survey(VES-13) scoring systems were significantly associated with increased long term mortality risk.Conclusion: Simplified frailty-assessing tools should be routinely used in elderly cancer patients before treatment in order to stratify patient risk. The TUG, ECOG-PS, IADLs and VES-13 scoring systems are potentially able to predict long-term mortality and disability. Additional studies will be needed to confirm the preliminary data in order to improve management strategies for oncogeriatric surgical patients.展开更多
To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial ris...To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial risk index and ground risk index of the UAV are constructed,the index screening model and the UAV flight risk assessment model are established,and a UAV flight risk assessment model based on K-means clustering has been proposed.Meanwhile,numerical simulations show the proposed method can not only evaluate the UAV flight risks effectively,but also provide technical support for UAV risk management and control.展开更多
Chronic atrophic gastritis (CAG) is an inflammatory condition characterized by the loss of gastric glandular structures which are replaced by connective tissue (non-metaplastic atrophy) or by glandular structures ...Chronic atrophic gastritis (CAG) is an inflammatory condition characterized by the loss of gastric glandular structures which are replaced by connective tissue (non-metaplastic atrophy) or by glandular structures inappropriate for location (metaplastic atrophy). Epidemiological data suggest that CAG is associated with two different types of tumors: Intestinal-type gastric cancer (GC) and type I gastric carcinoid (T I GC). The pathophysiological mechanisms which lead to the development of these gastric tumors are different, It is accepted that a multistep process initiating from Helico- bacterpylori-related chronic inflammation of the gastric mucosa progresses to CAG, intestinal metaplasia, dysplasia and, finally, leads to the development of GC. The T I GC is a gastrin-dependent tumor and the chronic elevation of gastrin, which is associated with CAG, stimulates the growth of enterochromaffin-like cells with their hyperplasia leading to the development of T I GC. Thus, several events occur in the gastric mucosa before the development of intestinatype GC and/ or T I GC and these take several years. Knowledge ofCAG incidence from superficial gastritis, its prevalence in different clinical settings and possible risk factors as- sociated with the progression of this condition to gastric neoplasias are important issues. This editorial intends to provide a brief review of the main studies regarding incidence and prevalence of CAG and risk factors for the development of gastric neoplasias.展开更多
AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence...AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resis- tance genes and genes encoding enzymes respon- sible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test RESULTS: JDM301 was shown to contain 36 genes as- sociated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence fac- tors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, ami- kacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imi- penem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated. CONCLUSION: The safety assessment of JDM301 using information derived from complete bacterial ge- nome will contribute to a wider and deeper insight into the safety of probiotic bacteria.展开更多
The elements of crop capacity structure of 13 summer characteristics in 33 winter wheat varieties, qualitative three-regularity and quantitative eight-regularity are investigated through the application of systematic ...The elements of crop capacity structure of 13 summer characteristics in 33 winter wheat varieties, qualitative three-regularity and quantitative eight-regularity are investigated through the application of systematic approach. The principle of triadness applied in a language, in a genetic code and other codes is used, i.e. the logic homology is employed. The purpose are (1) to show the use of a systematic approach to the analysis of elements of crop capacity structure of winter wheat; (2) to analyze efficiency, the years of harvests and winter hardiness; (3) to find the way of selection and varieties assessment in terms of the elements efficiency. The quantitative compatibility as the highest with the sign "+" and the lowest with the sign "-" in terms of elements efficiency gives eight types of crop capacities. The type of crop capacity structure "+++" can serve as a full (higher) measure of a variety adaptableness and optimality of technologies. The triad of three characteristics as a type-"+++" in which the first sign is the quantity of ears (QE); the second is a quantity of grains (QG); the third is the weight of grains (WG) creates the highest level of crop capacity.展开更多
Coal bursts involve the sudden,violent ejection of coal or rock into the mine workings. They are almost always accompanied by a loud noise,like an explosion,and ground vibration. Bursts are a particular hazard for min...Coal bursts involve the sudden,violent ejection of coal or rock into the mine workings. They are almost always accompanied by a loud noise,like an explosion,and ground vibration. Bursts are a particular hazard for miners because they typically occur without warning. Despite decades of research,the sources and mechanics of these events are not well understood,and therefore they are difficult to predict and control. Experience has shown,however,that certain geologic and mining factors are associated with an increased likelihood of a coal burst. A coal burst risk assessment consists of evaluating the degree to which these risk factors are present,and then identifying appropriate control measures to mitigate the hazard. This paper summarizes the U.S. and international experience with coal bursts,and describes the known risk factors in detail. It includes a framework that can be used to guide the risk assessment process.展开更多
Radium (Ra) isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a (ehl-a), suspended particula...Radium (Ra) isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a (ehl-a), suspended particulate matter (SPM) and Ra isotopes (223Ra, 224Ra and 226Ra) of surface waters of the Zhujiang (Pearl) River estuary (ZRE) were measured. This was done for both winter (December) and summer (July) seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially Z24Ra (about 2-5 times higher). The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM (low light penetration). The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.展开更多
Although most cases of acute nonvariceal gastrointestinal hemorrhage either spontaneously resolve or respond to medical management or endoscopic treatment,there are still a significant number of patients who require e...Although most cases of acute nonvariceal gastrointestinal hemorrhage either spontaneously resolve or respond to medical management or endoscopic treatment,there are still a significant number of patients who require emergency angiography and transcatheter treatment.Evaluation with noninvasive imaging such as nuclear scintigraphy or computed tomography may localize the bleeding source and/or confirm active hemorrhage prior to angiography.Any angiographic evaluation should begin with selective catheterization of the artery supplying the most likely site of bleeding,as determined by the available clinical,endoscopic and imaging data.If a hemorrhage source is identified,superselective catheterization followed by transcatheter microcoil embolization is usually the most effective means of successfully controlling hemorrhage while minimizing potential complications.This is now wellrecognized as a viable and safe alternative to emergency surgery.In selected situations transcatheter intra-arterial infusion of vasopressin may also be useful in controlling acute gastrointestinal bleeding.One must be aware of the various side effects and potential complications associated with this treatment,however,and recognize the high re-bleeding rate.In this article we review the current role of angiography,transcatheter arterial embolization and infusion therapy in the evaluation and management of nonvariceal gastrointestinal hemorrhage.展开更多
A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural n...A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.展开更多
Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are ...Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are the central and leading players in this process, while economic activities serve as the driving force and space is the carrier-the physical or material setting as well as the product. So the coordination among these processes is crucial for a country or region's sustainable development. China is experiencing rapid growth of cities and a surge in urban population, with the basic national condition of many people and little land, which calls for a systematic study of the issue of coordinated urbanization from theoretical, methodological and practical perspectives. Based on the concept of urbanization and non-coordination of urbanization, this article built a quantitative method to identify and evaluate the urbanization and non-coordination of urbanization, and made an empirical analysis in China between 2000 and 2008. The results show that the non-coordination overall level of China's urbanization declined during the study period, because population urbanization, economic urbanization, and space urbanization exhibited different trajectories of change. This study also reveals that performance assessment system, household registration system, and urban land expropriation system, etc., are the main affecting factors. At the end, we put forward some suggestions to achieve sustainable development of China's urbanization from the aspects of improving the local government's obiective function, imolementing the urban plalming svstem, enforcing public particination asnects and so on.展开更多
基金Supported by the National High Technology Research and Development Program of China("863"Program)(2006AA12A105)~~
文摘A new safety assessment method for parallel routes is presented. From the aspects of safety guard system of air traffic control(ATC) and considering the flight conflict as causing event of air collision accidents, this paper fosters a four-layer safety guard of controller command, short-term conflict alerts (STCAs), pilot visual avoidance, and traffic alert collision avoidance system(TCAS). Then, the problem of parallel routes collision risk is divided into two parts:the calculation of potential flight conflict and the analysis of failure probability of the four-layer safety guard. A calculation model for controller interference times is induced. By using cognitive reliability and error analysis method(CREAM),the calculation problem to failure probability of controller sequencing flight conflicts is solved and a fault tree model of guard failure of STCA and TCAS is established. Finally, the Beijing-Shanghai parallel routes are taken as an example to be calculated and the collision risk of the parallel routes is obtained under the condition of radar control. Results show that the parallel routes can satisfy the safety demands.
基金This study was supported by the National Key Tech-nologies R & D Program of China (2006BAD03A09)Agrifund of China’s Ministry of Science and Technology (2006GB24910472)
文摘An assessment index system including environment, socio-culture, economy and technology was established for evaluating environmental construction level of community (objective construction), and questionnaire was designed according to paper review for evaluating residential satisfaction (subjective satisfaction). The index system was divided into four layers: system (A), subsystems (B), categories (C), and indicators (D), and in total of 38 indicators was established. The Xihe community, affiliated to Nanfen district, Benxi City, Liaoning Province, China was selected as a case study. Results indicated that the community sustainability index related to objective environmental construction was 0.4355 and was classified as class Ⅲ (moderate); the community sustainability index related to the residential satisfaction was 0.4255, belonging to class Ⅲ. In conclusion, the sustainability of Xihe community was moderate and needed to be improved. Residential satisfaction was lower than objective environmental construction. The assessment index system established in this study is able to reflect the comprehensive sustainability of community and can be used to evaluate other similar communities' sustainability.
文摘The veracity of land evaluation is tightly related to the reasonable weights of land evaluation fac- tors. By mapping qualitative linguistic words into a fine-changeable cloud drops and translating the uncertain factor conditions into quantitative values with the uncertain illation based on cloud model, and then, inte- grating correlation analysis, a new way of figuring out the weight of land evaluation factors is proposed. It may solve the limitations of the conventional ways.
文摘Background This prospective study integrated multiple clinical indexes and inflammatory markers associated with coronary atherosclerotic vulnerable plaque to establish a risk prediction model that can evaluate a patient with certain risk factors for the likelihood of the occurrence of a coronary heart disease event within one year. Methods This study enrolled in 2686 patients with mild to moderate coronary artery lesions. Eighty-five indexes were recorded, included baseline clinical data, laboratory studies, and procedural characteristics. During the 1-year follow-up, 233 events occurred, five patients died, four patients suffered a nonfatal myocardial infarction, four patients underwent revascularization, and 220 patients were readmitted for angina pectoris. The Risk Estimation Model and the Simplified Model were conducted using Bayesian networks and compared with the Single Factor Models. Results The area under the curve was 0.88 for the Bayesian Model and 0.85 for the Simplified Model, while the Single Factor Model had a maximum area under the curve of 0.65. Conclusion The new models can be used to assess the short-term risk of individual coronary heart disease events and may assist in guiding preventive care.
基金supported by Program for Changjiang Scholars and Innovative Research Team in University (IRT1188)
文摘In recent years,the immune-modulatory role of all-trans astaxanthin from different pigment sources has been studied.It was reported that all-trans astaxanthin might exist as three stereoisomers,and the composition of all-trans stereoisomers in natural materials differs from that of synthetic products.However,the different biological effects of various all-trans stereoisomers still remain unclear.In the present study,we evaluated the bioactivity of three astaxanthin stereoisomers,(3S,3'S)-trans-,(3R,3'R)-transand meso-trans-astaxanthin,in regulating cell-mediated immune response using mice lymphocytes and peritoneal exudates cells(PECs) systems.After the treatment with three astaxanthin stereoisomers(20 μmol L-1),the lymphocyte proliferation capacity,neutral red phagocytosis of PECs and natural killer(NK) cell cytotoxic activity were comparatively assessed.The results showed that all three astaxanthin stereoisomers significantly promoted lymphocyte proliferation,phagocytic capacity of PECs,and cytotoxic activity of NK cells.Moreover,the(3S,3'S)-trans-astaxanthin exhibited a much higher response than others.
文摘The estimation of lifetime morbid events is not a rare presentation of relatively old and of more recent epidemi- ological investigations, accompanied by evaluating rates, risks and predictors (more in general determinants or risk factors). However, when the follow-up period is very long and Kaplan-Meier survival curves are adopted, or Kaplan- Meier-based more complex models such as Cox's analysis are used, clinical (or epidemiological) reality may well be distorted since by these survival methods risks tend to be overestimated, whereas survival tends to be reduced.
文摘Objective: Cancer is one of the most common diagnoses in elderly patients. Of all types of abdominal cancer, colorectal cancer(CRC) is undoubtedly the most frequent. Median age at diagnosis is approximately 70 years old worldwide. Due to the multiple comorbidities affecting elderly people, frailty evaluation is very important in order to avoid over- or undertreatment. This pilot study was designed to investigate the variables capable of predicting the long-term risk of mortality and living situation after surgery for CRC.Methods: Patients with 70 years old and older undergoing elective surgery for CRC were prospectively enrolled in the study. The patients were preoperatively screened using 11 internationally-validated-frailty-assessment tests. The endpoints of the study were long-term mortality and living situation. The data were analyzed using univariate Cox proportional-hazard regression analysis to verify the predictive value of score indices in order to identify possible risk factors.Results: Forty-six patients were studied. The median follow-up time after surgery was 4.6 years(range, 2.9-5.7 years) and no patients were lost to follow-up. The overall mortality rate was 39%. Four of the patients who survived(4/28, 14%) lost their functional autonomy. The preoperative impaired Timed Up and Go(TUG), Eastern Cooperative Group Performance Status(ECOG PS), Instrumental Activities of Daily Living(IADLs), Vulnerable Elders Survey(VES-13) scoring systems were significantly associated with increased long term mortality risk.Conclusion: Simplified frailty-assessing tools should be routinely used in elderly cancer patients before treatment in order to stratify patient risk. The TUG, ECOG-PS, IADLs and VES-13 scoring systems are potentially able to predict long-term mortality and disability. Additional studies will be needed to confirm the preliminary data in order to improve management strategies for oncogeriatric surgical patients.
基金supported in part by the National Natural Science Foundation of China (Nos. 71971114,61573181)Open Grant of State Key Laboratory of Air Traffic Management System and Technique(No. SKLATM201801).
文摘To quantify unmanned aerial vehicle(UAV)flight risks in low-altitude airspace,we analyze the factors of UAV flight risks from three aspects:flight conflict,flight environment,and traffic characteristics.The aerial risk index and ground risk index of the UAV are constructed,the index screening model and the UAV flight risk assessment model are established,and a UAV flight risk assessment model based on K-means clustering has been proposed.Meanwhile,numerical simulations show the proposed method can not only evaluate the UAV flight risks effectively,but also provide technical support for UAV risk management and control.
文摘Chronic atrophic gastritis (CAG) is an inflammatory condition characterized by the loss of gastric glandular structures which are replaced by connective tissue (non-metaplastic atrophy) or by glandular structures inappropriate for location (metaplastic atrophy). Epidemiological data suggest that CAG is associated with two different types of tumors: Intestinal-type gastric cancer (GC) and type I gastric carcinoid (T I GC). The pathophysiological mechanisms which lead to the development of these gastric tumors are different, It is accepted that a multistep process initiating from Helico- bacterpylori-related chronic inflammation of the gastric mucosa progresses to CAG, intestinal metaplasia, dysplasia and, finally, leads to the development of GC. The T I GC is a gastrin-dependent tumor and the chronic elevation of gastrin, which is associated with CAG, stimulates the growth of enterochromaffin-like cells with their hyperplasia leading to the development of T I GC. Thus, several events occur in the gastric mucosa before the development of intestinatype GC and/ or T I GC and these take several years. Knowledge ofCAG incidence from superficial gastritis, its prevalence in different clinical settings and possible risk factors as- sociated with the progression of this condition to gastric neoplasias are important issues. This editorial intends to provide a brief review of the main studies regarding incidence and prevalence of CAG and risk factors for the development of gastric neoplasias.
基金Supported by The National Key Program for Infectious Diseases of China,No. 2008ZX10004 and 2009ZX10004the Program of Shanghai Subject Chief Scientist,No. 09XD1402700+1 种基金the Program of Shanghai Research and Development,No. 10JC1408200a China Partnering Award from the Biotechnology and Biological Sciences Research Council,United Kingdom
文摘AIM: To assess the safety of Bifidobacterium/ongum (B. longum) JDM301 based on complete genome sequences. METHODS: The complete genome sequences of JDM301 were determined using the GS 20 system. Putative virulence factors, putative antibiotic resis- tance genes and genes encoding enzymes respon- sible for harmful metabolites were identified by blast with virulence factors database, antibiotic resistance genes database and genes associated with harmful metabolites in previous reports. Minimum inhibitory concentration of 16 common antimicrobial agents was evaluated by E-test RESULTS: JDM301 was shown to contain 36 genes as- sociated with antibiotic resistance, 5 enzymes related to harmful metabolites and 162 nonspecific virulence fac- tors mainly associated with transcriptional regulation, adhesion, sugar and amino acid transport. B. longum JDM301 was intrinsically resistant to ciprofloxacin, ami- kacin, gentamicin and streptomycin and susceptible to vancomycin, amoxicillin, cephalothin, chloramphenicol, erythromycin, ampicillin, cefotaxime, rifampicin, imi- penem and trimethoprim-sulphamethoxazol. JDM301 was moderately resistant to bacitracin, while an earlier study showed that bifidobacteria were susceptible to this antibiotic. A tetracycline resistance gene with the risk of transfer was found in JDM301, which needs to be experimentally validated. CONCLUSION: The safety assessment of JDM301 using information derived from complete bacterial ge- nome will contribute to a wider and deeper insight into the safety of probiotic bacteria.
文摘The elements of crop capacity structure of 13 summer characteristics in 33 winter wheat varieties, qualitative three-regularity and quantitative eight-regularity are investigated through the application of systematic approach. The principle of triadness applied in a language, in a genetic code and other codes is used, i.e. the logic homology is employed. The purpose are (1) to show the use of a systematic approach to the analysis of elements of crop capacity structure of winter wheat; (2) to analyze efficiency, the years of harvests and winter hardiness; (3) to find the way of selection and varieties assessment in terms of the elements efficiency. The quantitative compatibility as the highest with the sign "+" and the lowest with the sign "-" in terms of elements efficiency gives eight types of crop capacities. The type of crop capacity structure "+++" can serve as a full (higher) measure of a variety adaptableness and optimality of technologies. The triad of three characteristics as a type-"+++" in which the first sign is the quantity of ears (QE); the second is a quantity of grains (QG); the third is the weight of grains (WG) creates the highest level of crop capacity.
文摘Coal bursts involve the sudden,violent ejection of coal or rock into the mine workings. They are almost always accompanied by a loud noise,like an explosion,and ground vibration. Bursts are a particular hazard for miners because they typically occur without warning. Despite decades of research,the sources and mechanics of these events are not well understood,and therefore they are difficult to predict and control. Experience has shown,however,that certain geologic and mining factors are associated with an increased likelihood of a coal burst. A coal burst risk assessment consists of evaluating the degree to which these risk factors are present,and then identifying appropriate control measures to mitigate the hazard. This paper summarizes the U.S. and international experience with coal bursts,and describes the known risk factors in detail. It includes a framework that can be used to guide the risk assessment process.
基金Supported by the National Natural Science Foundation of China(Nos.41576075,41106072,41376085)the Natural Science Foundation of Shangdong Province(No.ZR2012DQ002)the Ministry of Land and Resources Program(Nos.GZH201200505,201411072)
文摘Radium (Ra) isotopes are useful for tracing water mass transport and examining estuarine hydrological dynamics. In this study, several hydrological parameters, nutrients, ehlorophyll-a (ehl-a), suspended particulate matter (SPM) and Ra isotopes (223Ra, 224Ra and 226Ra) of surface waters of the Zhujiang (Pearl) River estuary (ZRE) were measured. This was done for both winter (December) and summer (July) seasons, to quantitatively understand the seasonal characteristics of river plume flow rate and trajectories, as well as the ecological response. The results show that Ra concentrations in summer were higher than in winter, especially Z24Ra (about 2-5 times higher). The spatial distribution of three Ra isotopes and relative Ra water ages indicated that river water mainly flushed out of ZRE through the western side in winter, where the water transport was about 5 days faster than in the eastern zone. In summer, diluted river water expended to the east side, resulting in fairly similar water ages for both sides of the river mouth. Although nutrients were higher during the summer season, lower chl-a concentrations indicated that reduced primary production might be caused by high SPM (low light penetration). The results obtained from this study will provide knowledge needed for effectively developing and managing the ZRE.
文摘Although most cases of acute nonvariceal gastrointestinal hemorrhage either spontaneously resolve or respond to medical management or endoscopic treatment,there are still a significant number of patients who require emergency angiography and transcatheter treatment.Evaluation with noninvasive imaging such as nuclear scintigraphy or computed tomography may localize the bleeding source and/or confirm active hemorrhage prior to angiography.Any angiographic evaluation should begin with selective catheterization of the artery supplying the most likely site of bleeding,as determined by the available clinical,endoscopic and imaging data.If a hemorrhage source is identified,superselective catheterization followed by transcatheter microcoil embolization is usually the most effective means of successfully controlling hemorrhage while minimizing potential complications.This is now wellrecognized as a viable and safe alternative to emergency surgery.In selected situations transcatheter intra-arterial infusion of vasopressin may also be useful in controlling acute gastrointestinal bleeding.One must be aware of the various side effects and potential complications associated with this treatment,however,and recognize the high re-bleeding rate.In this article we review the current role of angiography,transcatheter arterial embolization and infusion therapy in the evaluation and management of nonvariceal gastrointestinal hemorrhage.
文摘A comprehensive risk based security assessment which includes low voltage, line overload and voltage collapse was presented using a relatively new neural network technique called as the generalized regression neural network (GRNN) with incorporation of feature extraction method using principle component analysis. In the risk based security assessment formulation, the failure rate associated to weather condition of each line was used to compute the probability of line outage for a given weather condition and the extent of security violation was represented by a severity function. For low voltage and line overload, continuous severity function was considered due to its ability to zoom in into the effect of near violating contingency. New severity function for voltage collapse using the voltage collapse prediction index was proposed. To reduce the computational burden, a new contingency screening method was proposed using the risk factor so as to select the critical line outages. The risk based security assessment method using GRNN was implemented on a large scale 87-bus power system and the results show that the risk prediction results obtained using GRNN with the incorporation of principal component analysis give better performance in terms of accuracy.
基金Under the auspices of National Natural Science Foundation of China(No.41071109)Fundamental Research Funds for the Central University(No.10SSXT137)
文摘Urbanization is a comprehensive concept, a trinity process that population urbanization, economic urbanization and space urbanization, is based on the interactions and mutual influences among the in which, people are the central and leading players in this process, while economic activities serve as the driving force and space is the carrier-the physical or material setting as well as the product. So the coordination among these processes is crucial for a country or region's sustainable development. China is experiencing rapid growth of cities and a surge in urban population, with the basic national condition of many people and little land, which calls for a systematic study of the issue of coordinated urbanization from theoretical, methodological and practical perspectives. Based on the concept of urbanization and non-coordination of urbanization, this article built a quantitative method to identify and evaluate the urbanization and non-coordination of urbanization, and made an empirical analysis in China between 2000 and 2008. The results show that the non-coordination overall level of China's urbanization declined during the study period, because population urbanization, economic urbanization, and space urbanization exhibited different trajectories of change. This study also reveals that performance assessment system, household registration system, and urban land expropriation system, etc., are the main affecting factors. At the end, we put forward some suggestions to achieve sustainable development of China's urbanization from the aspects of improving the local government's obiective function, imolementing the urban plalming svstem, enforcing public particination asnects and so on.