The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different op...The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.展开更多
Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( met...Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( meteorological factors and sowing days) and ET3 (meteorological factors, sowing days and water content). And the predicted result was compared with actual value ET that was obtained by weighing method. The results showed that the ET3 model had higher calculation precision and an optimum BP-artificial neural network model for calculating crop evapotranspiration.展开更多
A 21-day laboratory incubation experiment was conducted to investigate the impact of pesticides (insecticide, herbicide, fungicide) on paddy field soil health under controlled moisture (flooded soil) and temperature (...A 21-day laboratory incubation experiment was conducted to investigate the impact of pesticides (insecticide, herbicide, fungicide) on paddy field soil health under controlled moisture (flooded soil) and temperature (25 ℃) environment. The electron transport system (ETS)/Dehydrogenase activity showed negative correlation with pesticides concentrations, decreased with increase of pesticide concentration. The higher doses(5 to 10 times field rates) of pesticides significantly inhibited ETS activity, while lower rates failed to produce any significant reducing effect on the control. The toxicity of pesticides in decreasing the ETS activity was in the order: insecticide > fungicide > herbicide, irrespective of their rates of application. The pesticides increased the soil phenol content, which increased with increasing concentration of agrochemicals. The pesticide application did not produce any significant change in soil protein content. The response of biomass phospholipid content was nearly similar to that of ETS activity. The phospholipid content decreased with the addition of pesticides in the order insecticide > fungicide > herbicide and the toxicity was in the order: 10 FR (field rate) > 5 FR > 1.0 FR > 0.5 FR > control.展开更多
Survival rates for metastatic lung cancer, including non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), are poor with S-year survivals of less than 5%. The immune system has an intricate and com...Survival rates for metastatic lung cancer, including non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), are poor with S-year survivals of less than 5%. The immune system has an intricate and complex relationship with tumorigenesis; a groundswell of research on the immune system is leading to greater understanding of how cancer progresses and presenting new ways to halt disease progress. Due to the extraordinary power of the immune system-- with its capacity for memory, exquisite specificity and central and universal role in human biology--immunotherapy has the potential to achieve complete, long-lasting remissions and cures, with few side effects for any cancer patient, regardless of cancer type. As a result, a range of cancer therapies are under development that work by turning our own immune cells against tumors. However deeper understanding of the complexity of immunomodulation by tumors is key to the development of effective immunotherapies, especially in lung cancer.展开更多
The formation of Stagnic Anthrosols is closely related to rice planting and parent materials. Six representative pedons, two from each of three Stagnic Anthrosol subgroups, Vertic Haplic-, Vertic Gleyic-, and Sulfic G...The formation of Stagnic Anthrosols is closely related to rice planting and parent materials. Six representative pedons, two from each of three Stagnic Anthrosol subgroups, Vertic Haplic-, Vertic Gleyic-, and Sulfic Gleyic-Stagnic Anthrosols, from different parent materials and soil formation processes, from Liaoning Province, China, were selected and used along with additional supporting data to assess the potential impact in each soil subgroup combination of both pedogenic and anthropogenic factors on the migration and geochemical characteristics of calcium (Ca) and magnesium (Mg) and their relations to soil particle-size composition. Results revealed that exchangeable Mg was correlated positively with clay and silt content, but negatively with sand content, suggesting that clay and silt could retain more exchangeable Mg than sand. Also, in the six pedons exchangeable Ca/Mg ratios generally decreased with depth, which was most likely due to the preferential retention of Mg below the Apl horizon and the effects of bio-cycling in rice-soil systems. The pedons with high pH had smaller exchangeable Ca/Mg ratios than those with low pH. Thus, it was concluded that exchangeable Ca/Mg ratios could be helpful in classification of Stagnic Anthrosols.展开更多
This paper proposes a high specificity and sensitivity algorithm called PromPredictor for recognizing promoter regions in the human genome. PromPredictor extracts compositional features and CpG islands information fro...This paper proposes a high specificity and sensitivity algorithm called PromPredictor for recognizing promoter regions in the human genome. PromPredictor extracts compositional features and CpG islands information from genomic sequence,feeding these features as input for a hybrid neural network system (HNN) and then applies the HNN for prediction. It combines a novel promoter recognition model, coding theory, feature selection and dimensionality reduction with machine learning algorithm.Evaluation on Human chromosome 22 was ~66% in sensitivity and ~48% in specificity. Comparison with two other systems revealed that our method had superior sensitivity and specificity in predicting promoter regions. PromPredictor is written in MATLAB and requires Matlab to run. PromPredictor is freely available at http://www.whtelecom.com/Prompredictor.htm.展开更多
Patients older than 65 years are the fastest growing segment of the cancer population. It is estimated that within 20 years over 75% of cases and 85% of deaths from colorectal cancer (CRC) will be in this setting. Con...Patients older than 65 years are the fastest growing segment of the cancer population. It is estimated that within 20 years over 75% of cases and 85% of deaths from colorectal cancer (CRC) will be in this setting. Concerns about cancer treatment in the elderly relate to comorbidities, which increase proportionally with age, physiological changes associated with aging which may influence drug metabolism and toxicity, and diminishing life expectancy, which particularly impacts decisions surrounding the benefits of adjuvant therapies. Over the last 10 years, significant improvements in the treatment of advanced CRC with combination therapy have been made. The randomized trials which have defined these improvements did not exclude elderly patients. However, the median age of patients in these trials has generally been approximately 60 years. Thus, it appears that some degree of selection is involved with younger and presumably fitter patients being the subjects in most of the pivotal trials. The availability of new molecularly targeted agents and newly improved existing agents has expanded the range of treatment options available. This variety gives greater flexibility in dealing with different subsets of patients, such as the elderly. However, some fit elderly patients seem to tolerate combination therapy reasonably well, while studies on unfit elderly subjects are needed.展开更多
This study is aimed at investigating the potentials of ex vivo expansion and pluri-differentiation of cryopreservation of adult human bone marrow mesenchymal stem cells (hMSCs) into chondrocytes, adipocytes and neur...This study is aimed at investigating the potentials of ex vivo expansion and pluri-differentiation of cryopreservation of adult human bone marrow mesenchymal stem cells (hMSCs) into chondrocytes, adipocytes and neurocytes. Cryopreserved hMSCs were resuscitated and cultured for 15 passages, and then induced into chondrocytes, adipocytes and neurocytes with corresponding induction medium. The induced cells were observed for morphological properties and detected for expressions of type II collagen, triglyceride or neuron-specific enolase and nestin. The result showed that the resuscitated cells could differentiate into chondrocytes after exposure to transforming growth factor 61 (TGF-~0, insulin-like growth factor I (IGF-I) and vitamin C (Vc), and uniformly changed morphologically from a spindle-like fibroblastic appearance to a polygonal shape in three weeks. The induced cells were heterochromatic to safranin O and expressed cartilage matrix-procollagenal (If) mRNA. The resuscitated cells cultured in induction medium consisting of dexamethasone, 3-isobutyl-l-methylxanthine, indomethacin and IGF-I showed adipogenesis, and lipid vacuoles accumulation was detectable after 21 d. The resuscitated hMSCs were also induced into neurocytes and expressed nestin and neuron specific endolase (NSE) that were special surface markers associated with neural cells at different stage. This study suggested that the resuscitated hMSCs should be still a population ofpluripotential cells and that it could be used for establishing an abundant bMSC reservoir for further experiment and treatment of various clinical discases.展开更多
Human stem cells are scalable cell populations capable of cellular differentiation.This makes them a very attractive in vitro cellular resource and in theory provides unlimited amounts of primary cells.Such an approac...Human stem cells are scalable cell populations capable of cellular differentiation.This makes them a very attractive in vitro cellular resource and in theory provides unlimited amounts of primary cells.Such an approach has the potential to improve our understanding of human biology and treating disease.In the future it may be possible to deploy novel stem cell-based approaches to treat human liver diseases.In recent years,eff icient hepatic differentiation from human stem cells has been achieved by several research groups including our own.In this review we provide an overview of the f ield and discuss the future potential and limitations of stem cell technology.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
Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand s...Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand structure, dominance and diversity is very crucial. Here, the effects of different disturbance regimes, along a gradient, on diversity and dominance of five Shorea robusta Gaertn. f.-dominated forests were investigated in 25 one-ha plots in Nepal. A total of 67 tree species were recorded; of which 41 species were encountered in least disturbed and 10 species in beavily disturbed forest. Significant variations among forests were observed for all measures of alpha diversity. Alpha diversity measures declined linearly along a disturbance gradient while dominance increased linearly. Relative basal area of S. robusta increased as the level of disturbance increased, which in turn produced more than two-fold higher important value index in heavily disturbed forest than the least disturbed forest. All alpha diversity measures declined in an order of three with increasing relative basal area of S. robusta. The similarity in species composition between each pair of disturbed forests was generally low (Jaccard's similarity index 〈 57%), suggesting a higher Beta diversity, It can be concluded that diversity of Sal forests declines with increasing magnitude of disturbance, which in turn favors a higher domi- nance of S. robusta. Controlling the population of the dominant species, mainly S. robusta, is recommended to enhance diversity and to achieve multiple-use forest management objectives.展开更多
AIM: To establish a culture system of marrow mesenchymal stem cells (MSCs)from hepatitis B patients and normal adults and to compare their biological characteristics. METHODS: MSCs were isolated from bone marrow in 34...AIM: To establish a culture system of marrow mesenchymal stem cells (MSCs)from hepatitis B patients and normal adults and to compare their biological characteristics. METHODS: MSCs were isolated from bone marrow in 34 male hepatitis B patients and 15 male normal adults and cultivated in vitro. Their biological characteristics including surface markers, shapes and appearances, growth curves, first passage time and passage generations were compared. RESULTS: Cultivation achievement ratio of hepatitis B patients was lower than that of normal adults, no statistical significance (82.35% vs 100%, P > 0.05). Compared with MSCs of normal adults, MSCs of hepatitis B patients presented a statistical lower growth curve, longer first passage time (13.0 ± 1.6 d vs 11.4 ± 1.5 d, P < 0.05), fewer passaging generation numbers (10.5 ± 1.4 generations vs 12.3 ± 1.7 generations, P < 0.05), though both shared same appearances, shapes and surface markers. MSCs in hepatitis B patients would expand, spread out and age more easily and there were more refractive particles in the cytoplasm. CONCLUSION: MSCs from hepatitis B patients can be cultured in vitro. Although their appearance, shape and surface marker are similar to those of MSCs from normal adults, there are differences in their biological characteristics.展开更多
Currently, the aging of the population has become the world's social problem. With the increase of aging population and lots of disability, paralysis makes nursing care more difficult. Because of many elderly cannot ...Currently, the aging of the population has become the world's social problem. With the increase of aging population and lots of disability, paralysis makes nursing care more difficult. Because of many elderly cannot get timely care, the phenomenon that the elderly have chronic diseases has become more and more serious. It is important to research and develop a new product which can help the elderly and the disabled for improving the quality of their life. This paper suggests a new type of mnltifunctional self-caring wheelchair-bed, which is combined with a wheelchair and a bed. The bed can realize the free conversion among user sitting, leg lifting and lying down, and also can implement the function of turning on sides. Particularly, the wheelchair can be easily separated from the bed and combined, so that patients and the elderly can move freely using it, and even it can be transformed into a standing type to satisfy the patient's standing demand, and to a certain extent, carry out the purpose of rehabilitation.展开更多
Objective: Cell and platelet attachment on the multiwalled carbon nanotubes (MWCNTs) were studied by ion implantation. Methods: NH2 ion implantation was performed at the energy of 30 keV with the fluence of 1 x 10...Objective: Cell and platelet attachment on the multiwalled carbon nanotubes (MWCNTs) were studied by ion implantation. Methods: NH2 ion implantation was performed at the energy of 30 keV with the fluence of 1 x 1016 ions/era2 at room temperature. Results: The cell attachment tests showed interesting results in that the number of the platclets adhering on the surface of the MWCNTs was reduced significantly after NH2 ion implantation, whereas, mouse fibroblast cells (L929) cultured on NH2 ion implanted MWCNTs displayed higher cell-viability, proliferation, and stretching compared with MWCNTs. Conclusion: No appreciable change in the tensile strength and the optical transmittance of the implanted samples was observed. X-ray photoelectron spectroscopy (XPS) analysis showed that NH2 ion implantation caused the formation of new N-containing groups.展开更多
基金The National Natural Science Foundation of China(No.51508257,51668042,51578274)the Yangtze River Scholar and the Innovation Team of M inistry of Education(No.IRT13068)the Scientific Research Project of Gansu Higher Education(No.2015B-34)
文摘The human-induced vertical vibration serviceability of low-frequency and lightweight footbridges is studied based on the moving mass-spring-damper(MMSD) biodynamic model, and the mass damper(TMD) with different optimal model parameters being used to control the vertical vibration.First, the MMSD biodynamic model is employed to simulate the pedestrians, and the time-varying control equations of the vertical dynamic coupling system of the pedestrian-bridgeTMD are established with the consideration of pedestrianbridge dynamic interaction; and the equations are solved by using the Runge-Kutta-Felhberg integral method with variable step size. Secondly, the footbridge dynamic response is calculated under the model of pedestrian-structure dynamic interaction and the model of moving load when the pedestrian pace frequency is consistent with the natural frequency of footbridge. Finally, a comparative study and analysis are made on the control effects of the vertical dynamic coupling system in different optimal models of the TMD. The calculation results show that the pedestrian-bridge dynamic interaction cannot be ignored when the vertical human-induced vibration serviceability of low-frequency and light-weight footbridge is evaluated. The TMD can effectively reduce the vibration under the resonance of pedestrian-bridge, and TMD parameters are recommended for the determination by the Warburton optimization model.
基金Supported by the National Natural Science Foundation of China(50609022)~~
文摘Based on potted plant experiment, BP-artifieial neural network was used to simulate crop evapotranspiration and 3 kinds of artificial neural network models were constructed as ET1 (meteorological factors), ET2( meteorological factors and sowing days) and ET3 (meteorological factors, sowing days and water content). And the predicted result was compared with actual value ET that was obtained by weighing method. The results showed that the ET3 model had higher calculation precision and an optimum BP-artificial neural network model for calculating crop evapotranspiration.
文摘A 21-day laboratory incubation experiment was conducted to investigate the impact of pesticides (insecticide, herbicide, fungicide) on paddy field soil health under controlled moisture (flooded soil) and temperature (25 ℃) environment. The electron transport system (ETS)/Dehydrogenase activity showed negative correlation with pesticides concentrations, decreased with increase of pesticide concentration. The higher doses(5 to 10 times field rates) of pesticides significantly inhibited ETS activity, while lower rates failed to produce any significant reducing effect on the control. The toxicity of pesticides in decreasing the ETS activity was in the order: insecticide > fungicide > herbicide, irrespective of their rates of application. The pesticides increased the soil phenol content, which increased with increasing concentration of agrochemicals. The pesticide application did not produce any significant change in soil protein content. The response of biomass phospholipid content was nearly similar to that of ETS activity. The phospholipid content decreased with the addition of pesticides in the order insecticide > fungicide > herbicide and the toxicity was in the order: 10 FR (field rate) > 5 FR > 1.0 FR > 0.5 FR > control.
文摘Survival rates for metastatic lung cancer, including non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC), are poor with S-year survivals of less than 5%. The immune system has an intricate and complex relationship with tumorigenesis; a groundswell of research on the immune system is leading to greater understanding of how cancer progresses and presenting new ways to halt disease progress. Due to the extraordinary power of the immune system-- with its capacity for memory, exquisite specificity and central and universal role in human biology--immunotherapy has the potential to achieve complete, long-lasting remissions and cures, with few side effects for any cancer patient, regardless of cancer type. As a result, a range of cancer therapies are under development that work by turning our own immune cells against tumors. However deeper understanding of the complexity of immunomodulation by tumors is key to the development of effective immunotherapies, especially in lung cancer.
基金1 Project supported by the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-413-9) and theNational High Technology Research and Development Program of China (No. 2004AA246020).
文摘The formation of Stagnic Anthrosols is closely related to rice planting and parent materials. Six representative pedons, two from each of three Stagnic Anthrosol subgroups, Vertic Haplic-, Vertic Gleyic-, and Sulfic Gleyic-Stagnic Anthrosols, from different parent materials and soil formation processes, from Liaoning Province, China, were selected and used along with additional supporting data to assess the potential impact in each soil subgroup combination of both pedogenic and anthropogenic factors on the migration and geochemical characteristics of calcium (Ca) and magnesium (Mg) and their relations to soil particle-size composition. Results revealed that exchangeable Mg was correlated positively with clay and silt content, but negatively with sand content, suggesting that clay and silt could retain more exchangeable Mg than sand. Also, in the six pedons exchangeable Ca/Mg ratios generally decreased with depth, which was most likely due to the preferential retention of Mg below the Apl horizon and the effects of bio-cycling in rice-soil systems. The pedons with high pH had smaller exchangeable Ca/Mg ratios than those with low pH. Thus, it was concluded that exchangeable Ca/Mg ratios could be helpful in classification of Stagnic Anthrosols.
基金Project (No. 2001AA231071) supported by the Hi-Tech Researchand Development Program (863) of China
文摘This paper proposes a high specificity and sensitivity algorithm called PromPredictor for recognizing promoter regions in the human genome. PromPredictor extracts compositional features and CpG islands information from genomic sequence,feeding these features as input for a hybrid neural network system (HNN) and then applies the HNN for prediction. It combines a novel promoter recognition model, coding theory, feature selection and dimensionality reduction with machine learning algorithm.Evaluation on Human chromosome 22 was ~66% in sensitivity and ~48% in specificity. Comparison with two other systems revealed that our method had superior sensitivity and specificity in predicting promoter regions. PromPredictor is written in MATLAB and requires Matlab to run. PromPredictor is freely available at http://www.whtelecom.com/Prompredictor.htm.
文摘Patients older than 65 years are the fastest growing segment of the cancer population. It is estimated that within 20 years over 75% of cases and 85% of deaths from colorectal cancer (CRC) will be in this setting. Concerns about cancer treatment in the elderly relate to comorbidities, which increase proportionally with age, physiological changes associated with aging which may influence drug metabolism and toxicity, and diminishing life expectancy, which particularly impacts decisions surrounding the benefits of adjuvant therapies. Over the last 10 years, significant improvements in the treatment of advanced CRC with combination therapy have been made. The randomized trials which have defined these improvements did not exclude elderly patients. However, the median age of patients in these trials has generally been approximately 60 years. Thus, it appears that some degree of selection is involved with younger and presumably fitter patients being the subjects in most of the pivotal trials. The availability of new molecularly targeted agents and newly improved existing agents has expanded the range of treatment options available. This variety gives greater flexibility in dealing with different subsets of patients, such as the elderly. However, some fit elderly patients seem to tolerate combination therapy reasonably well, while studies on unfit elderly subjects are needed.
基金Project supported by the Science Foundation (No. 2003C23015) and the Natural Science Foundation (No. Y204139) of Zhejiang Province, China
文摘This study is aimed at investigating the potentials of ex vivo expansion and pluri-differentiation of cryopreservation of adult human bone marrow mesenchymal stem cells (hMSCs) into chondrocytes, adipocytes and neurocytes. Cryopreserved hMSCs were resuscitated and cultured for 15 passages, and then induced into chondrocytes, adipocytes and neurocytes with corresponding induction medium. The induced cells were observed for morphological properties and detected for expressions of type II collagen, triglyceride or neuron-specific enolase and nestin. The result showed that the resuscitated cells could differentiate into chondrocytes after exposure to transforming growth factor 61 (TGF-~0, insulin-like growth factor I (IGF-I) and vitamin C (Vc), and uniformly changed morphologically from a spindle-like fibroblastic appearance to a polygonal shape in three weeks. The induced cells were heterochromatic to safranin O and expressed cartilage matrix-procollagenal (If) mRNA. The resuscitated cells cultured in induction medium consisting of dexamethasone, 3-isobutyl-l-methylxanthine, indomethacin and IGF-I showed adipogenesis, and lipid vacuoles accumulation was detectable after 21 d. The resuscitated hMSCs were also induced into neurocytes and expressed nestin and neuron specific endolase (NSE) that were special surface markers associated with neural cells at different stage. This study suggested that the resuscitated hMSCs should be still a population ofpluripotential cells and that it could be used for establishing an abundant bMSC reservoir for further experiment and treatment of various clinical discases.
基金Supported by A RCUK fellowship,EP/E500145/1,to Hay DCA grant from the Edinburgh Bioquarter,to Medine CNChina Scholarship Council,No.2010658022,to Zhou WL
文摘Human stem cells are scalable cell populations capable of cellular differentiation.This makes them a very attractive in vitro cellular resource and in theory provides unlimited amounts of primary cells.Such an approach has the potential to improve our understanding of human biology and treating disease.In the future it may be possible to deploy novel stem cell-based approaches to treat human liver diseases.In recent years,eff icient hepatic differentiation from human stem cells has been achieved by several research groups including our own.In this review we provide an overview of the f ield and discuss the future potential and limitations of stem cell technology.
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Disturbance is often touted as a management tool, as moderate disturbance is believed to enhance diversity; thus an understanding of frequent and fluctuating disturbance regimes in forests and their effects on stand structure, dominance and diversity is very crucial. Here, the effects of different disturbance regimes, along a gradient, on diversity and dominance of five Shorea robusta Gaertn. f.-dominated forests were investigated in 25 one-ha plots in Nepal. A total of 67 tree species were recorded; of which 41 species were encountered in least disturbed and 10 species in beavily disturbed forest. Significant variations among forests were observed for all measures of alpha diversity. Alpha diversity measures declined linearly along a disturbance gradient while dominance increased linearly. Relative basal area of S. robusta increased as the level of disturbance increased, which in turn produced more than two-fold higher important value index in heavily disturbed forest than the least disturbed forest. All alpha diversity measures declined in an order of three with increasing relative basal area of S. robusta. The similarity in species composition between each pair of disturbed forests was generally low (Jaccard's similarity index 〈 57%), suggesting a higher Beta diversity, It can be concluded that diversity of Sal forests declines with increasing magnitude of disturbance, which in turn favors a higher domi- nance of S. robusta. Controlling the population of the dominant species, mainly S. robusta, is recommended to enhance diversity and to achieve multiple-use forest management objectives.
基金Technology Project Fund of Guangdong Province, No. 2003A3020303
文摘AIM: To establish a culture system of marrow mesenchymal stem cells (MSCs)from hepatitis B patients and normal adults and to compare their biological characteristics. METHODS: MSCs were isolated from bone marrow in 34 male hepatitis B patients and 15 male normal adults and cultivated in vitro. Their biological characteristics including surface markers, shapes and appearances, growth curves, first passage time and passage generations were compared. RESULTS: Cultivation achievement ratio of hepatitis B patients was lower than that of normal adults, no statistical significance (82.35% vs 100%, P > 0.05). Compared with MSCs of normal adults, MSCs of hepatitis B patients presented a statistical lower growth curve, longer first passage time (13.0 ± 1.6 d vs 11.4 ± 1.5 d, P < 0.05), fewer passaging generation numbers (10.5 ± 1.4 generations vs 12.3 ± 1.7 generations, P < 0.05), though both shared same appearances, shapes and surface markers. MSCs in hepatitis B patients would expand, spread out and age more easily and there were more refractive particles in the cytoplasm. CONCLUSION: MSCs from hepatitis B patients can be cultured in vitro. Although their appearance, shape and surface marker are similar to those of MSCs from normal adults, there are differences in their biological characteristics.
基金National Natural Science Foundation of Chinagrant number: 11172208, 11072087 and 31000422+1 种基金Jilin Natural Science Foundationgrant number: 201115023
文摘Currently, the aging of the population has become the world's social problem. With the increase of aging population and lots of disability, paralysis makes nursing care more difficult. Because of many elderly cannot get timely care, the phenomenon that the elderly have chronic diseases has become more and more serious. It is important to research and develop a new product which can help the elderly and the disabled for improving the quality of their life. This paper suggests a new type of mnltifunctional self-caring wheelchair-bed, which is combined with a wheelchair and a bed. The bed can realize the free conversion among user sitting, leg lifting and lying down, and also can implement the function of turning on sides. Particularly, the wheelchair can be easily separated from the bed and combined, so that patients and the elderly can move freely using it, and even it can be transformed into a standing type to satisfy the patient's standing demand, and to a certain extent, carry out the purpose of rehabilitation.
基金National Natural Science Foundation of China grant number: 51272176 and 11075116+3 种基金National Basic Research Program of China (973 program) grant number: 2012CB933604The Open Research Fund of the State Key Laboratory of Bioelectronics, Southeast Universitythe Key Laboratory of Beam Technology and Material Modification of the Ministry of Education,Beijing Normal University, China
文摘Objective: Cell and platelet attachment on the multiwalled carbon nanotubes (MWCNTs) were studied by ion implantation. Methods: NH2 ion implantation was performed at the energy of 30 keV with the fluence of 1 x 1016 ions/era2 at room temperature. Results: The cell attachment tests showed interesting results in that the number of the platclets adhering on the surface of the MWCNTs was reduced significantly after NH2 ion implantation, whereas, mouse fibroblast cells (L929) cultured on NH2 ion implanted MWCNTs displayed higher cell-viability, proliferation, and stretching compared with MWCNTs. Conclusion: No appreciable change in the tensile strength and the optical transmittance of the implanted samples was observed. X-ray photoelectron spectroscopy (XPS) analysis showed that NH2 ion implantation caused the formation of new N-containing groups.