B2B E Commerce is one of the most potential electronic commerce forms at present. But since traditional B2 B E Commerce system lacks an unified standard and solution of basic architectur e a nd interface, it has m...B2B E Commerce is one of the most potential electronic commerce forms at present. But since traditional B2 B E Commerce system lacks an unified standard and solution of basic architectur e a nd interface, it has many shortcomings such as poor reusability and poor extensi bility. In order to solve the problem, combined with Web Service technology, a B 2B E Commerce system model based on Web Service is proposed and analyzed. The m odel can combine relatively independent Web Service on Intranet and Internet by constructing core application program. As a part of supply chain, it can also pr ovide a standard interface for other applications such as ERP/CRM/SCM, etc. Th er efore, B2B E Commerce system with this form is easy for development, integratio n and maintenance. Finally, a solution of B2B E Commerce system based on Web Se rvice is propounded by introducing an instance.展开更多
AIM: To investigate the incidence of clinically detected port-site metastasis (PSM) in patients who underwent robotic surgery for biliary malignancies. METHODS: Using a prospective database, the patients undergoin...AIM: To investigate the incidence of clinically detected port-site metastasis (PSM) in patients who underwent robotic surgery for biliary malignancies. METHODS: Using a prospective database, the patients undergoing fully robotic surgery for biliary malignan- cies between January 2009 and January 2011 were in- cluded. Records of patients with confirmed malignancy were reviewed for clinicopathological data and informa- tion about PSM. RESULTS: Sixty-four patients with biliary tract cancers underwent robotic surgery, and sixty patients met the inclusion criteria. The median age was 67 year (range: 40-85 year). During a median 15-mo follow-up period, two female patients were detected solitary PSM after robotic surgery. The incidence of PSM was 3.3%. Pa- tient 1 underwent robotic anatomatic left hemihepa- tectomy and extraction of biliary tumor thrombi for an Klatskin tumor. She had a subcutaneous mass located at the right lateral abdominal wall near a trocar scar. Patient 2 underwent robotic pancreaticoduodenectomy for distal biliary cancer. She had two metachronous subcutaneous mass situated at the right lateral abdomi- nal wall under a same trocar scar at 7 and 26 mo. The pathology of the excised PSM masses confirmed meta- static biliary adenocarcinoma. CONCLUSION: The incidence of PSIVls after robotic surgery for biliary malignancies is relatively low, and biliary cancer can be an indication of robotic surgery.展开更多
The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes wh...The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000–5 100 m.We found Artemia in 15 of these lakes.The saline lakes with Artemia populations mainly belong to the shallow basin lakes,and the majority of these lakes are small in area.The total area of lakes without Artemia is more than 1 000 km 2.Lake Dangxiong Co(Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica.In 2004,850 g of A.sinica cysts,originating from Qinghai,were introduced in the lake.Surveys in 2006–2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m 3 in 2006 to 1950 ind./m 3 in 2013.We assume that two subpopulations of A.sinica,separated by depth,may exist in the lake.The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance.Water transparency also increased.Dominance in phytoplankton passed from cyanobacteria to diatoms.Changes occurred not only in the lake ecosystem;the number of water birds using the lakes also dramatically increased.Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.展开更多
This study explores the Chinese public’s perceptions of, and attitudes to, agriculture and food applications of bio-technology; and investigates the effect of socio-demographic factors on attitudes. A questionnaire s...This study explores the Chinese public’s perceptions of, and attitudes to, agriculture and food applications of bio-technology; and investigates the effect of socio-demographic factors on attitudes. A questionnaire survey and interviews were used in an attempt to combine quantitative analysis with qualitative review. The main finding of this study is that the Chinese population has a superficial, optimistic attitude to agricultural biotechnology; and that, in accordance with public attitudes, a cautious policy, with obligatory labelling, should be adopted. The study reveals that education is the factor among socio-demographic variables with the strongest impact on public attitudes. Higher education leads to a more positive evaluation of GM (genetically modified) foods and applications of biotechnology with respect to usefulness, moral acceptability, and suitability for encouragement. In addition, public attitudinal differences depend significantly on area of residence. Compared with their more urban compatriots, members of the public in less developed areas of China have more optimistic attitudes, perceive more benefits, and are more risk tolerant in relation to GM foods and agricultural biotechnology. Finally we obtained a very high rate of “don’t know” answers to our survey questions. This suggests that many people do not have settled attitudes, and correspondingly, that the overall public attitude to agricultural biotechnology and GM foods in China is at present somewhat unstable.展开更多
The push-pull framework provides a useful approach for examining the tourist motivation. This paper takes the world heritage-Huangshan Mountain as a sample. From the two different aspects of pull and push factors, the...The push-pull framework provides a useful approach for examining the tourist motivation. This paper takes the world heritage-Huangshan Mountain as a sample. From the two different aspects of pull and push factors, the underlying features of visitors′ motives to Huangshan Mountain are analyzed with the help of factor analysis. As a result, five push factors and four pull factors are identified. Further analyses investigate differences in the push and pull factors among different socio-demographic subgroups with one-way ANOVA analysis. The result of the study affords us useful references for development, protection and marketing expansion of mountain resorts.展开更多
Port-city system is a complex and integral system, and it can be simulated by system dynamic method, which is used to be employed to solve nonlinear problems. Based on the causality of the every element in the port-ci...Port-city system is a complex and integral system, and it can be simulated by system dynamic method, which is used to be employed to solve nonlinear problems. Based on the causality of the every element in the port-city system, the authors analyzed the feedback relation and logical relation among the system variables and system structure. A system-dynamic flow chart and correlation equations were put forward with VENSIM software, the quantitative relation was described, and the model was debugged. The development trend of the main influence factors in port-city system was simulated. By changing the influence degree of each related factor. It is found the parameters values of variables in the model, we studied that: 1) Foreign trade throughput of port play an important role in the development of export-oriented economy. 2) The development of primary industry and secondary industry affects most of the water transportation demand. With the constant increase of tertiary industry proportion in the industrial structure, the demand of national economy for water transportation decreases gradually. 3) Water transportation presents a kind of oversupply development situation, so port construction should properly slow down. 4) With the development of ports, its direct and indirect contribution to urban economy has been continuously increasing, but contribution rate will be continuously decreasing.展开更多
This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) ...This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.展开更多
In this research, LINGO is used successfully to solve the water supply system′s optimal operation model. Firstly, the language of LINGO and the using method were studied intensively, on the basis of which the model w...In this research, LINGO is used successfully to solve the water supply system′s optimal operation model. Firstly, the language of LINGO and the using method were studied intensively, on the basis of which the model was transformed to LINGO form and solved successfully. Secondly, the research on the interface between LINGO and the popular office software was made. The optimization software was developed, which had Excel as the workspace and LINGO as the core of computation. Through practice, this software was found stable, easy to use and suitable for the application to the water supply corporations.展开更多
Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water whe...Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained.展开更多
AIM:To investigate the proficiency level reached in laparoscopic splenectomy using the learning curve method.METHODS:All patients in need of splenectomy for benign causes in whom laparoscopic splenectomy was attempted...AIM:To investigate the proficiency level reached in laparoscopic splenectomy using the learning curve method.METHODS:All patients in need of splenectomy for benign causes in whom laparoscopic splenectomy was attempted by a single surgeon during a time period of 6 years were included in the study (n=33). Besides demographics, operation-related variables and the response to surgery were recorded. The patients were allocated to groups of five, ranked according to the date of the operation. Operation duration, complications, postoperative length of stay, conversion to laparotomy and splenic weight were then compared between these groups.RESULTS: There was a significant difference regarding operation times between the groups (P = 0.001). An improvement was observed after the first 5 cases. The learning curve was flat up to the 25th case. Following the 25th case the operation times decreased still further. There was no difference between the groups regarding the other parameters.CONCLUSION: Unlike the widely accepted "L" shape, the learning curve for laparoscopic splenectomy is a horizontal lazy "S" with two distinct slopes. Privileges may be granted after the first 5 cases. However proficiency seems to require 25 cases.展开更多
AIM: To study the prevalence and risk factors associated with triple infection with human immunodeficiency virus (HIV)/hepatitis B virus (HBV)/hepatitis C virus (HCV) in an urban clinic population. METHODS: Re...AIM: To study the prevalence and risk factors associated with triple infection with human immunodeficiency virus (HIV)/hepatitis B virus (HBV)/hepatitis C virus (HCV) in an urban clinic population. METHODS: Retrospective chart review of 5639 patients followed at St. Luke's-Roosevelt Hospital HIV Clinic (Center for Comprehensive Care) in New York City, USA from January 1999 to May 2007. The following demographic characteristics were analyzed: age, sex, race and HIV risk factors. A multiple logistic regression analysis was performed to evaluate the influence of demographic factors on acquisition of these viruses. RESULTS: HIV/HBV, HIV/HCV and HIV/HBV/HCV infections were detected in 252/5639 (4.47%), 1411/5639 (25.02%) and 89/5639 (1.58%) patients, respectively. HIV/HBV co-infections were associated with male gender (OR 1.711; P = 0.005), black race (OR 2.091, P 〈 0.001), men having sex with men (MSM) (OR 1.747, P = 0.001), intravenous drug use (IDU) (OR 0.114, P 〈 0.001), IDU and heterosexual activity (OR 0.247; P = 0.018), or unknown (OR 1.984, P = 0.004).HIV/HCV co-infections were associated with male gender (OR 1.241; P = 0.011), black race (OR 0.788; P = 0.036), MSM (OR 0.565; P 〈 0.001), IDU (OR 8.956; P 〈 0.001), IDU and heterosexual activity (OR 9.106; P 〈 0.001), IDU and MSM (OR 9.179; P 〈 0.001), or transfusion (OR 3.224; P 〈 0.001). HIV/HBV/HCV coinfections were associated with male gender (OR 2.156; P = 0.015), IDU (OR 6.345; P 〈 0.001), IDU and heterosexual activity (OR 9.731; P 〈 0.001), IDU and MSM (OR 9.228; P 〈 0.001), or unknown (OR 4.219; P = 0.007). CONCLUSION: Our study demonstrates that coinfection with HBV/HCV/HIV is significantly associated with IDU. These results highlight the need to intensify education and optimal models of integrated care, particularly for populations with IDU, to reduce the risk of viral transmission.展开更多
Objective To retrospectively evaluate the diagnosis and treatment of Mirizzi syndrome (MS). Methods Patients who received elective or emergency cholecystectomies in our center during 23 years were retrospectively e...Objective To retrospectively evaluate the diagnosis and treatment of Mirizzi syndrome (MS). Methods Patients who received elective or emergency cholecystectomies in our center during 23 years were retrospectively evaluated. The data reviewed included demography, clinical presentations, diagnostic methods, surgical procedures, postoperative complications, and follow-up.展开更多
AIM:To investigate health-related quality of life(HRQoL) and psychological outcomes in 256 adults who had undergone liver transplantation(LT).METHODS:A stratified random sampling method was used in this follow-up mult...AIM:To investigate health-related quality of life(HRQoL) and psychological outcomes in 256 adults who had undergone liver transplantation(LT).METHODS:A stratified random sampling method was used in this follow-up multicenter study to select a representative sample of recipients undergoing either living donor liver transplantation(LDLT) or deceased donor liver transplantation(DDLT).HRQoL was measured by using the Chinese version of Medical Outcome Study Short Form-36(SF-36),and psychological outcomes by using the beck anxiety inventory(BAI) and the self-rating depression scale(SDS).Clinical and demographic data were collected from the records of the Chinese Liver Transplant Registry and via questionnaires.RESULTS:A total of 256 patients were sampled,including 66(25.8%) receiving LDLT and 190(74.2%) undergoing DDLT;15(5.9%) recipients had anxiety and four(1.6%) developed severe depression after the operation.Compared with LDLT recipients,DDLT patients had higher scores in general health(60.33 ± 16.97 vs 66.86 ± 18.42,P = 0.012),role-physical(63.64 ± 42.55 vs 74.47 ± 36.46,P = 0.048),roleemotional(61.11 ± 44.37 vs 78.95 ± 34.31,P = 0.001),social functioning(78.60 ± 22.76 vs 88.16 ± 21.85,P = 0.003),vitality(70.30 ± 15.76 vs 75.95 ± 16.40,P = 0.016),mental health(65.88 ± 12.94 vs 71.85 ± 15.45,P = 0.005),physical component summary scale(PCS,60.07 ± 7.36 vs 62.58 ± 6.88,P = 0.013) and mental component summary scale(MCS,52.65 ± 7.66 vs 55.95 ± 10.14,P = 0.016).Recipients > 45 years old at the time of transplant scored higher in vitality(77.33 ± 15.64 vs 72.52 ± 16.66,P = 0.020),mental health(73.64 ± 15.06 vs 68.00 ± 14.65,P = 0.003) and MCS(56.61 ± 10.00 vs 54.05 ± 9.30,P = 0.037) than those aged ≤ 45 years.MCS was poorer in recipients with than in those without complications(52.92 ± 12.21 vs 56.06 ± 8.16,P = 0.017).Regarding MCS(55.10 ± 9.66 vs 50.0 ± 10.0,P < 0.05) and PCS(61.93 ± 7.08 vs 50.0 ± 10.0,P < 0.05),recipients scored better than the Sichuan general and had improved overall QoL compared to patients with chronic diseases.MCS and PCS significantly correlated with scores of the BAI(P < 0.001) and the SDS(P < 0.001).CONCLUSION:Age > 45 years at time of transplant,DDLT,full-time working,no complications,anxiety and depression were possible factors influencing postoperative HRQoL in liver recipients.展开更多
In this paper, we review the current state- of-the-art techniques used for understanding the inner workings of the brain at a systems level. The neural activity that governs our everyday lives involves an intricate co...In this paper, we review the current state- of-the-art techniques used for understanding the inner workings of the brain at a systems level. The neural activity that governs our everyday lives involves an intricate coordination of many processes that can be attributed to a variety of brain regions. On the surface, many of these functions can appear to be controlled by specific anatomical structures; however, in reality, numerous dynamic networks within the brain contribute to its function through an interconnected web of neuronal and synaptic pathways. The brain, in its healthy or pathological state, can therefore be best understood by taking a systems-level approach. While numerous neuroengineering technologies exist, we focus here on three major thrusts in the field of systems neuroengineering: neuroimaging, neural interfacing, and neuromodulation. Neuroimaging enables us to delineate the structural and functional organization of the brain, which is key in understanding how the neural system functions in both normal and disease states. Based on such knowledge, devices can be used either to communicate with the neural system, as in neural interface systems, or to modulate brain activity, as in neuromodulation systems. The consideration of these three fields is key to the development and application of neuro-devices. Feedback-based neuro-devices require the ability to sense neural activity (via a neuroimaging modality) through a neural interface (invasive or noninvasive) and ultimately to select a set of stimulation parameters in order to alter neural function via a neuromodulation modality. Systems neuroengineering refers to the use of engineering tools and technologies to image, decode, and modulate the brain in order to comprehend its functions and to repair its dysfunction. Interactions between these fields will help to shape the future of systems neuroengineering--to develop neurotechniques for enhancing the understanding of whole- brain function and dysfunction, and the management of neurological and mental disorders.展开更多
In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking acce...In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.展开更多
Background High body mass index (BMI) is a risk factor for chronic cardiac disease. However, mounting evidence supports that high BMI is associated with less risk of cardiac morbidity and mortality compared with nor...Background High body mass index (BMI) is a risk factor for chronic cardiac disease. However, mounting evidence supports that high BMI is associated with less risk of cardiac morbidity and mortality compared with normal BMI, also known as the obesity paradox. There- fore, we sought to determine the existence of the obesity paradox in regard to perioperative 30-day cardiac events among elderly Chinese patients with known coronary artery disease undergoing non-cardiac surgery. Methods A post-hoc analysis of a prospective, multi-institutional cohort study was performed. Patients aged 〉 60 years with a history of coronary artery disease and undergoing non-cardiac surgery were grouped according to BMI: underweight (〈 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese (≥ 30 kg/m2). Demographic information, perioperative clinical variables and incidence of 30-day postoperative cardiac adverse event were retrieved from a research database. Results We identified 1202 eligible patients (BMI: 24.3 ± 3.8 kg/m2). Across BMI groups, a U-shaped distribution pattern of incidence of 30-day postoperative major cardiac events was observed, with the lowest risk in the overweight group. When using the normal-weight group as a reference, no difference was found in either the obesity or overweight groups in terms of a major cardiac adverse event (MACE). However, risk of a 30-day postoperative MACE was significantly higher in the underweight group (odds ratio [OR] 2.916, 95% confidence interval [CI]: 1.072-7.931, P = 0.036). Conclusion Although not statistically significant, the U-shaped relation between BMI and cardiac complications indicates the obesity paradox possibly exists.展开更多
文摘B2B E Commerce is one of the most potential electronic commerce forms at present. But since traditional B2 B E Commerce system lacks an unified standard and solution of basic architectur e a nd interface, it has many shortcomings such as poor reusability and poor extensi bility. In order to solve the problem, combined with Web Service technology, a B 2B E Commerce system model based on Web Service is proposed and analyzed. The m odel can combine relatively independent Web Service on Intranet and Internet by constructing core application program. As a part of supply chain, it can also pr ovide a standard interface for other applications such as ERP/CRM/SCM, etc. Th er efore, B2B E Commerce system with this form is easy for development, integratio n and maintenance. Finally, a solution of B2B E Commerce system based on Web Se rvice is propounded by introducing an instance.
基金Supported by Eleven-five Special Subject of PLA Medicine and Health,No.08Z016
文摘AIM: To investigate the incidence of clinically detected port-site metastasis (PSM) in patients who underwent robotic surgery for biliary malignancies. METHODS: Using a prospective database, the patients undergoing fully robotic surgery for biliary malignan- cies between January 2009 and January 2011 were in- cluded. Records of patients with confirmed malignancy were reviewed for clinicopathological data and informa- tion about PSM. RESULTS: Sixty-four patients with biliary tract cancers underwent robotic surgery, and sixty patients met the inclusion criteria. The median age was 67 year (range: 40-85 year). During a median 15-mo follow-up period, two female patients were detected solitary PSM after robotic surgery. The incidence of PSM was 3.3%. Pa- tient 1 underwent robotic anatomatic left hemihepa- tectomy and extraction of biliary tumor thrombi for an Klatskin tumor. She had a subcutaneous mass located at the right lateral abdominal wall near a trocar scar. Patient 2 underwent robotic pancreaticoduodenectomy for distal biliary cancer. She had two metachronous subcutaneous mass situated at the right lateral abdomi- nal wall under a same trocar scar at 7 and 26 mo. The pathology of the excised PSM masses confirmed meta- static biliary adenocarcinoma. CONCLUSION: The incidence of PSIVls after robotic surgery for biliary malignancies is relatively low, and biliary cancer can be an indication of robotic surgery.
基金Supported by the Special Fund for Public Welfare Land and Resources(No.201011001-4)the Project of China Geological Survey(No.1212011120982)
文摘The imbalance between supply and demand of Artemia cysts in China and around the world is increasing now.Salt lakes in Tibet may contribute to the solution of the problem.In Northern Tibet there are 26 saline lakes whose salinity and temperature may support Artemia survival at an altitude of 4 000–5 100 m.We found Artemia in 15 of these lakes.The saline lakes with Artemia populations mainly belong to the shallow basin lakes,and the majority of these lakes are small in area.The total area of lakes without Artemia is more than 1 000 km 2.Lake Dangxiong Co(Co means lake in Tibet) was chosen for the intentional introduction of Artemia sinica.In 2004,850 g of A.sinica cysts,originating from Qinghai,were introduced in the lake.Surveys in 2006–2014 showed that the average abundance of Artemia adults in the lake gradually increased from 20 ind./m 3 in 2006 to 1950 ind./m 3 in 2013.We assume that two subpopulations of A.sinica,separated by depth,may exist in the lake.The new Artemia population caused an increase in the number of species of phytoplankton and heterotrophic protozoa with a decrease of their total abundance.Water transparency also increased.Dominance in phytoplankton passed from cyanobacteria to diatoms.Changes occurred not only in the lake ecosystem;the number of water birds using the lakes also dramatically increased.Preliminary calculations showed that is it possible to harvest at least about 150 t cysts per year from the lake as well as 3.2 thousand tons of frozen or 350 t of dried biomass of adult Artemia.
基金Project supported by the Ministry of Foreign Affairs, Denmark (No.104.p.3.kina.236) and the Natural Science Foundation (No.KYZ110303077) of Zhejiang Province, China
文摘This study explores the Chinese public’s perceptions of, and attitudes to, agriculture and food applications of bio-technology; and investigates the effect of socio-demographic factors on attitudes. A questionnaire survey and interviews were used in an attempt to combine quantitative analysis with qualitative review. The main finding of this study is that the Chinese population has a superficial, optimistic attitude to agricultural biotechnology; and that, in accordance with public attitudes, a cautious policy, with obligatory labelling, should be adopted. The study reveals that education is the factor among socio-demographic variables with the strongest impact on public attitudes. Higher education leads to a more positive evaluation of GM (genetically modified) foods and applications of biotechnology with respect to usefulness, moral acceptability, and suitability for encouragement. In addition, public attitudinal differences depend significantly on area of residence. Compared with their more urban compatriots, members of the public in less developed areas of China have more optimistic attitudes, perceive more benefits, and are more risk tolerant in relation to GM foods and agricultural biotechnology. Finally we obtained a very high rate of “don’t know” answers to our survey questions. This suggests that many people do not have settled attitudes, and correspondingly, that the overall public attitude to agricultural biotechnology and GM foods in China is at present somewhat unstable.
文摘The push-pull framework provides a useful approach for examining the tourist motivation. This paper takes the world heritage-Huangshan Mountain as a sample. From the two different aspects of pull and push factors, the underlying features of visitors′ motives to Huangshan Mountain are analyzed with the help of factor analysis. As a result, five push factors and four pull factors are identified. Further analyses investigate differences in the push and pull factors among different socio-demographic subgroups with one-way ANOVA analysis. The result of the study affords us useful references for development, protection and marketing expansion of mountain resorts.
基金Under the auspices of National Natural Science Foundation of China(No.40871063)
文摘Port-city system is a complex and integral system, and it can be simulated by system dynamic method, which is used to be employed to solve nonlinear problems. Based on the causality of the every element in the port-city system, the authors analyzed the feedback relation and logical relation among the system variables and system structure. A system-dynamic flow chart and correlation equations were put forward with VENSIM software, the quantitative relation was described, and the model was debugged. The development trend of the main influence factors in port-city system was simulated. By changing the influence degree of each related factor. It is found the parameters values of variables in the model, we studied that: 1) Foreign trade throughput of port play an important role in the development of export-oriented economy. 2) The development of primary industry and secondary industry affects most of the water transportation demand. With the constant increase of tertiary industry proportion in the industrial structure, the demand of national economy for water transportation decreases gradually. 3) Water transportation presents a kind of oversupply development situation, so port construction should properly slow down. 4) With the development of ports, its direct and indirect contribution to urban economy has been continuously increasing, but contribution rate will be continuously decreasing.
文摘This paper attempts to explore a new avenue of urban small-regional population estimation by remote sensing technology, creatively and comprehensively for the first time using a residence count method, area (density) method and model method, incorporating the application experience of American scholars in the light of the state of our country. Firstly, the author proposes theoretical basis for population estimation by remote sensing, on the basis of analysing and evaluating the history and state quo of application of methods of population estimation by remote sensing. Secondly, two original types of mathematical models of population estimation are developed on the basis of remote sensing data, taking Tianjin City as an example. By both of the mathematical models the regional population may be estimated from remote sensing variable values with high accuracy. The number of the independent variables in the latter model is somewhat smaller and the collection of remote sensing data is somewhat easier, but the deviation is a little larger. Finally, some viewpoints on the principled problems about the practical application of remote sensing to population estimation are put forward.
文摘In this research, LINGO is used successfully to solve the water supply system′s optimal operation model. Firstly, the language of LINGO and the using method were studied intensively, on the basis of which the model was transformed to LINGO form and solved successfully. Secondly, the research on the interface between LINGO and the popular office software was made. The optimization software was developed, which had Excel as the workspace and LINGO as the core of computation. Through practice, this software was found stable, easy to use and suitable for the application to the water supply corporations.
基金Supported by Major State Basic Research Development Program of China ("973" Program, No. 2009CB219907)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT0936)
文摘Theoretical and experimental analysis of a new refrigerant mixture BY-3 was conducted based on a single-stage vapor compression refrigeration system. The water-water heat pump system used BY-3 to produce hot water when the low temperature was 20 ℃. The following results were obtained: the highest temperature at the condenser outlet reached about 85 ℃; when the difference between the water temperatures at the condenser outlet and the evaporator inlet was less than 40 ℃, the coefficient of performance (COP) was larger than 4; when the difference reached 55 ℃, the COP still kept 3; the discharge temperature of BY-3 was lower than 100 ℃, and the refrigerant vapor pressure kept lower than 1.8 MPa. When the water temperature at the condenser outlet reached over 85 ℃, nearly a 5 ℃ superheating temperature was maintained.
文摘AIM:To investigate the proficiency level reached in laparoscopic splenectomy using the learning curve method.METHODS:All patients in need of splenectomy for benign causes in whom laparoscopic splenectomy was attempted by a single surgeon during a time period of 6 years were included in the study (n=33). Besides demographics, operation-related variables and the response to surgery were recorded. The patients were allocated to groups of five, ranked according to the date of the operation. Operation duration, complications, postoperative length of stay, conversion to laparotomy and splenic weight were then compared between these groups.RESULTS: There was a significant difference regarding operation times between the groups (P = 0.001). An improvement was observed after the first 5 cases. The learning curve was flat up to the 25th case. Following the 25th case the operation times decreased still further. There was no difference between the groups regarding the other parameters.CONCLUSION: Unlike the widely accepted "L" shape, the learning curve for laparoscopic splenectomy is a horizontal lazy "S" with two distinct slopes. Privileges may be granted after the first 5 cases. However proficiency seems to require 25 cases.
文摘AIM: To study the prevalence and risk factors associated with triple infection with human immunodeficiency virus (HIV)/hepatitis B virus (HBV)/hepatitis C virus (HCV) in an urban clinic population. METHODS: Retrospective chart review of 5639 patients followed at St. Luke's-Roosevelt Hospital HIV Clinic (Center for Comprehensive Care) in New York City, USA from January 1999 to May 2007. The following demographic characteristics were analyzed: age, sex, race and HIV risk factors. A multiple logistic regression analysis was performed to evaluate the influence of demographic factors on acquisition of these viruses. RESULTS: HIV/HBV, HIV/HCV and HIV/HBV/HCV infections were detected in 252/5639 (4.47%), 1411/5639 (25.02%) and 89/5639 (1.58%) patients, respectively. HIV/HBV co-infections were associated with male gender (OR 1.711; P = 0.005), black race (OR 2.091, P 〈 0.001), men having sex with men (MSM) (OR 1.747, P = 0.001), intravenous drug use (IDU) (OR 0.114, P 〈 0.001), IDU and heterosexual activity (OR 0.247; P = 0.018), or unknown (OR 1.984, P = 0.004).HIV/HCV co-infections were associated with male gender (OR 1.241; P = 0.011), black race (OR 0.788; P = 0.036), MSM (OR 0.565; P 〈 0.001), IDU (OR 8.956; P 〈 0.001), IDU and heterosexual activity (OR 9.106; P 〈 0.001), IDU and MSM (OR 9.179; P 〈 0.001), or transfusion (OR 3.224; P 〈 0.001). HIV/HBV/HCV coinfections were associated with male gender (OR 2.156; P = 0.015), IDU (OR 6.345; P 〈 0.001), IDU and heterosexual activity (OR 9.731; P 〈 0.001), IDU and MSM (OR 9.228; P 〈 0.001), or unknown (OR 4.219; P = 0.007). CONCLUSION: Our study demonstrates that coinfection with HBV/HCV/HIV is significantly associated with IDU. These results highlight the need to intensify education and optimal models of integrated care, particularly for populations with IDU, to reduce the risk of viral transmission.
文摘Objective To retrospectively evaluate the diagnosis and treatment of Mirizzi syndrome (MS). Methods Patients who received elective or emergency cholecystectomies in our center during 23 years were retrospectively evaluated. The data reviewed included demography, clinical presentations, diagnostic methods, surgical procedures, postoperative complications, and follow-up.
基金Supported by A grant from the National Science and Technology Major Project of China,No.2008ZX10002-025, 2008ZX10002-026
文摘AIM:To investigate health-related quality of life(HRQoL) and psychological outcomes in 256 adults who had undergone liver transplantation(LT).METHODS:A stratified random sampling method was used in this follow-up multicenter study to select a representative sample of recipients undergoing either living donor liver transplantation(LDLT) or deceased donor liver transplantation(DDLT).HRQoL was measured by using the Chinese version of Medical Outcome Study Short Form-36(SF-36),and psychological outcomes by using the beck anxiety inventory(BAI) and the self-rating depression scale(SDS).Clinical and demographic data were collected from the records of the Chinese Liver Transplant Registry and via questionnaires.RESULTS:A total of 256 patients were sampled,including 66(25.8%) receiving LDLT and 190(74.2%) undergoing DDLT;15(5.9%) recipients had anxiety and four(1.6%) developed severe depression after the operation.Compared with LDLT recipients,DDLT patients had higher scores in general health(60.33 ± 16.97 vs 66.86 ± 18.42,P = 0.012),role-physical(63.64 ± 42.55 vs 74.47 ± 36.46,P = 0.048),roleemotional(61.11 ± 44.37 vs 78.95 ± 34.31,P = 0.001),social functioning(78.60 ± 22.76 vs 88.16 ± 21.85,P = 0.003),vitality(70.30 ± 15.76 vs 75.95 ± 16.40,P = 0.016),mental health(65.88 ± 12.94 vs 71.85 ± 15.45,P = 0.005),physical component summary scale(PCS,60.07 ± 7.36 vs 62.58 ± 6.88,P = 0.013) and mental component summary scale(MCS,52.65 ± 7.66 vs 55.95 ± 10.14,P = 0.016).Recipients > 45 years old at the time of transplant scored higher in vitality(77.33 ± 15.64 vs 72.52 ± 16.66,P = 0.020),mental health(73.64 ± 15.06 vs 68.00 ± 14.65,P = 0.003) and MCS(56.61 ± 10.00 vs 54.05 ± 9.30,P = 0.037) than those aged ≤ 45 years.MCS was poorer in recipients with than in those without complications(52.92 ± 12.21 vs 56.06 ± 8.16,P = 0.017).Regarding MCS(55.10 ± 9.66 vs 50.0 ± 10.0,P < 0.05) and PCS(61.93 ± 7.08 vs 50.0 ± 10.0,P < 0.05),recipients scored better than the Sichuan general and had improved overall QoL compared to patients with chronic diseases.MCS and PCS significantly correlated with scores of the BAI(P < 0.001) and the SDS(P < 0.001).CONCLUSION:Age > 45 years at time of transplant,DDLT,full-time working,no complications,anxiety and depression were possible factors influencing postoperative HRQoL in liver recipients.
基金supported in part by the US National Institutes of Health (NIH) (EB006433, EY023101, EB008389,and HL117664)the US National Science Foundation (NSF) (CBET1450956, CBET-1264782, and DGE-1069104),to Bin He
文摘In this paper, we review the current state- of-the-art techniques used for understanding the inner workings of the brain at a systems level. The neural activity that governs our everyday lives involves an intricate coordination of many processes that can be attributed to a variety of brain regions. On the surface, many of these functions can appear to be controlled by specific anatomical structures; however, in reality, numerous dynamic networks within the brain contribute to its function through an interconnected web of neuronal and synaptic pathways. The brain, in its healthy or pathological state, can therefore be best understood by taking a systems-level approach. While numerous neuroengineering technologies exist, we focus here on three major thrusts in the field of systems neuroengineering: neuroimaging, neural interfacing, and neuromodulation. Neuroimaging enables us to delineate the structural and functional organization of the brain, which is key in understanding how the neural system functions in both normal and disease states. Based on such knowledge, devices can be used either to communicate with the neural system, as in neural interface systems, or to modulate brain activity, as in neuromodulation systems. The consideration of these three fields is key to the development and application of neuro-devices. Feedback-based neuro-devices require the ability to sense neural activity (via a neuroimaging modality) through a neural interface (invasive or noninvasive) and ultimately to select a set of stimulation parameters in order to alter neural function via a neuromodulation modality. Systems neuroengineering refers to the use of engineering tools and technologies to image, decode, and modulate the brain in order to comprehend its functions and to repair its dysfunction. Interactions between these fields will help to shape the future of systems neuroengineering--to develop neurotechniques for enhancing the understanding of whole- brain function and dysfunction, and the management of neurological and mental disorders.
基金Under the auspices of National Nature Science Foundation of China(No.41701180)
文摘In the metropolises of China, the metro plays an increasingly important role in commuting because of its efficiency, affordability, and cleanliness. This paper attempts to explore the relationship between walking access distance to metro stations and the demographic characteristics of passengers, such as age, monthly income, travel frequency, gender, and travel purpose, as well as the influence of the urban context. Nanjing Metro Line 2 is selected as the case study. By using different methods such as a questionnaire survey, spatial decay function, analysis of covariance(ANOVA), network analysis of routes, and K-means cluster analysis, it is suggested that demographic characteristics have a significant impact on the pedestrian walking distance, with the exception of gender. Furthermore, the paper finds a spatial decay effect in walking access distance, the decay rate of which, however, varies across stations. Terminal stations have a larger pedestrian catchment area than in regular and exchange stations. Moreover, the passengers of Nanjing Metro Line 2 can be classified into six groups according to their demographic characteristics, among which education and occupation are vital indicators in determining their willingness to walk to the stations. Middle-class passengers have a higher dependence on the metro and tend to walk longer than other groups do. This study provides an important reference for planners and transport sectors to optimize land-use and transport infrastructures.
文摘Background High body mass index (BMI) is a risk factor for chronic cardiac disease. However, mounting evidence supports that high BMI is associated with less risk of cardiac morbidity and mortality compared with normal BMI, also known as the obesity paradox. There- fore, we sought to determine the existence of the obesity paradox in regard to perioperative 30-day cardiac events among elderly Chinese patients with known coronary artery disease undergoing non-cardiac surgery. Methods A post-hoc analysis of a prospective, multi-institutional cohort study was performed. Patients aged 〉 60 years with a history of coronary artery disease and undergoing non-cardiac surgery were grouped according to BMI: underweight (〈 18.5 kg/m2), normal weight (18.5-24.9 kg/m2), overweight (25-29.9 kg/m2) and obese (≥ 30 kg/m2). Demographic information, perioperative clinical variables and incidence of 30-day postoperative cardiac adverse event were retrieved from a research database. Results We identified 1202 eligible patients (BMI: 24.3 ± 3.8 kg/m2). Across BMI groups, a U-shaped distribution pattern of incidence of 30-day postoperative major cardiac events was observed, with the lowest risk in the overweight group. When using the normal-weight group as a reference, no difference was found in either the obesity or overweight groups in terms of a major cardiac adverse event (MACE). However, risk of a 30-day postoperative MACE was significantly higher in the underweight group (odds ratio [OR] 2.916, 95% confidence interval [CI]: 1.072-7.931, P = 0.036). Conclusion Although not statistically significant, the U-shaped relation between BMI and cardiac complications indicates the obesity paradox possibly exists.