Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil...Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil bacterial communities to co-invasion of two invaders daisy fleabane(Erigeron annuus)and Canada goldenrod(Solidago canadensis).Daisy fleabane and/or Canada goldenrod invasion significantly enhanced the operational taxonomic unit richness,Shannon index,and Chao1 index of soil bacterial communities.Canada goldenrod under light degree of invasion and co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree signally improved the ACE index of soil bacterial communities.Thus,the two invaders can enhance soil bacterial diversity and richness to facilitating subsequent invasion due to the fact that higher soil bacterial diversity and richness can enhance the levels of soil function and nutrients acquisition of plant species.ACE index of soil bacterial communities subjected to co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree was greater than that under the independent invasion of either daisy fleabane or Canada goldenrod.Hence,co-invasion of the two invaders can impose synergistic impacts on soil bacterial richness,which may build a preferable soil micro-environment via the intensified soil bacterial communities,which is contributive to their following invasion.展开更多
Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants...Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.展开更多
Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and...Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.展开更多
In order to obtain the remote center motion(RCM) mechanism with better performance indexes and avoid the collision of multi-manipulators in minimally invasive surgery(MIS), a novel multi-objective optimization model w...In order to obtain the remote center motion(RCM) mechanism with better performance indexes and avoid the collision of multi-manipulators in minimally invasive surgery(MIS), a novel multi-objective optimization model was presented. There were two optimization objectives: a global kinematic performance index and a comprehensive stiffness index. Other indexes to characterize the design requirements such as collision probability, workspace, mechanism parameter, mass, and wall thickness were considered as constraints. Angles between two adjacent joints and cross-section dimensions of links were chosen as the design variables. The non-dominated sorting genetic algorithm II(NSGA-II) was adopted to solve the complex multi-objective optimization problem. Then, a 3-degree of freedom(DoF) MIS robotic prototype based on optimization results has been built up. The experiments to test the spatial position change of the remote center point and to test the absolute position accuracy and repetitive position accuracy of the MIS robot were achieved, and the experimental results meet the requirements of MIS.展开更多
Introduction Hematogenous metastasis is the mainly leading cause of death in breast carcinoma patients.A better understanding of the underlying molecular and cellular mechanisms is crucial for the development of effec...Introduction Hematogenous metastasis is the mainly leading cause of death in breast carcinoma patients.A better understanding of the underlying molecular and cellular mechanisms is crucial for the development of effective treatment for metastatic breast cancer<sup>[</sup>1].It has been well established that cell adhesion and invasion is mediated by a variety of transmembrane proteins,including integrins,cadherins,selectins,and intercellular adhesion molecules.Among these adhesion molecules,the integrins and their downstream signaling pathways have been extensively studied<sup>[2]</sup>.On the other hand,the specific events determining tumor cell interactions with endo-展开更多
Despite significant progress in cancer research during the past decades,yet there are no major breakthroughs that can be translated into major benefits for the general public in terms of treatment or therapy for the c...Despite significant progress in cancer research during the past decades,yet there are no major breakthroughs that can be translated into major benefits for the general public in terms of treatment or therapy for the complex neoplastic diseases,especially for the malignant solid tumors.This depressing but indisputable fact leads to a call for new ideas to target tumor metastasis by editors of Nature Medicine<sup>[1]</sup>.The real problems are that the fundamental issues of transformation and malignancy in vivo are poorly understood.In a recent review on cancer,展开更多
Aim Solasodine, a steroidal alkaloid isolated from solanaceous species, has been reported to exhibit anticancer activity on several cell lines. The aim of this study is to explore the antitumor potential of solasodine...Aim Solasodine, a steroidal alkaloid isolated from solanaceous species, has been reported to exhibit anticancer activity on several cell lines. The aim of this study is to explore the antitumor potential of solasodine on ovarian cancer HEY cells. Methods MTT assay, Hoechst 33342 staining, JC-1 mitochondrial membrane potential assay, and LDH release assay were used to study the anti-proliferative and apoptosis-inducing effects of solasodine. MDC staining was to label the acidic puncta in the cells. Meanwhile, wound healing assay and transwell assay were performed to determine whether solasodine exhibits anti-metastasis effect on HEY cells. Gelatin zymography assay was used to determine the activities of MMP-2 and MMP-9 and Western blot was used to examine the expression of the relevant proteins. Results Solasodine inhibited the cell viability on HEY cells in time- and dose-dependent manners, causing shrinking of nuclei, damage of cell membrane, and appealing apoptotic body on high dosage and reducing cell mitochondrial membrane potential. It also inhibited autophagic flux that interfere autolysosome degra- dation. Furthermore, solasodine suppressed the migration and invasion abilities of HEY cells ascribable to down- regulating the expression and attenuating the activities of MMP-2 and MMP-9. Conclusion The inducing apoptosis and anti-metastasis activity of solasodine on HEY cells suggest it appears certain potential on ovarian cancer treat- ment.展开更多
Silver carp Hypophthalmichthys molitrix were introduced into the U.S. to control water quality in aquaculture ponds. From this point of origin, silver carp escaped into nearby rivers through multiple flood events. Bec...Silver carp Hypophthalmichthys molitrix were introduced into the U.S. to control water quality in aquaculture ponds. From this point of origin, silver carp escaped into nearby rivers through multiple flood events. Because of their documented negative effects on native biota, silver carp have been labeled as problematic. Therefore, evaluating the biology and ecology of these non-indigenous species is critical. Multiple parameters are needed to evaluate silver carp populations(length, weight, age, and sex). Furthermore, developing methods for rapidly acquiring these data are needed. In relation to sex determination, sexual dimorphism was observed where males exhibit distinct pectoral fin ray features. Specifically, males have pronounced ridges or a "rough patch" on the dorsal surface of pectoral fins. Therefore, to test if this was an applicable way of determining silver carp gender; silver carp were collected from Midwestern U.S. rivers(N=2015) in the fall of 2011(N=870), spring of 2012(N=645), winter of 2013—2014(N=202) and summer2015(N=323) via electrofishing. For each silver carp collected, presence(e.g., rough patch) or absence(e.g.,smooth) of pronounced ridges on the top side of the pectoral fins was recorded, and an incision was made in the body cavity to identify gender. Based on the results of our evaluation, gender was correctly identified over99% of the time(2006 out of 2015) based on the pectoral fin dimorphism. In the samples taken in the winter of 2013—2014 and summer of 2015, accuracy for silver carp shorter than 300 mm and longer than 800 mm was 53.7%(19 out of 41) while accuracy for silver carp between 300 mm and 800 mm total length was 98.9%(289 out of 292). This study provides a rapid assessment approach for evaluating silver carp gender.展开更多
Objective This study aims to compare the grafts patency rate in triple-vessel disease between minimally invasive direct and the standard off-pump coronary artery bypass grafting.Methods Fifty patients who were hospita...Objective This study aims to compare the grafts patency rate in triple-vessel disease between minimally invasive direct and the standard off-pump coronary artery bypass grafting.Methods Fifty patients who were hospitalized in Beijing ChaoYang Hospital during August 2013 to May 2015 were analyzed.MIDOPCABG group(n=25)underwent minimally invasive direct offpump coronary artery bypass grafting,and OPCABG group(n=25)underwent standard off-pump coronary artery bypass grafting group.展开更多
OBJECTIVE The invasive sea lamprey(Petromyzon marinus)has devastated the ecosystem of the Laurentian Great Lakes.Application of pheromones to manipulate adult sea lamprey behavior is among the options considered for a...OBJECTIVE The invasive sea lamprey(Petromyzon marinus)has devastated the ecosystem of the Laurentian Great Lakes.Application of pheromones to manipulate adult sea lamprey behavior is among the options considered for alternative sea lamprey control techniques.The male sea lamprey sex pheromone is hypothesized to be possess multiple functions through actions of multiple components,some of which have yet to be characterized.Our objective is to isolate and characterize the bioactive components from water conditioned with sexually mature male sea lamprey.METHODS The water conditioned with sexually mature male sea lamprey was extracted by solid phase extraction and concentrated in vacuo.The compounds were isolated by liquid chromatography and elucidated by spectrometry and spectroscopy.Their biological activities were evaluated by electro-olfactogram recordings and two-choice maze behavioral assays.RESULTS Five novel bile salts,petromyzene A and B and petromyzone A-C,have been characterized.Petromyzene A and B featured either a unique,rearranged side chain or a rare cis-11,12-diol on the steroidal B-ring.Petromyzone A-C represented three novel highly oxidized sulfated bile alcohols possessing different hydroxylation,oxidation,and double bond patterns,which exemplify the chemical diversity of bile salts.These five bile salts were potent odorants that stimulated the adult sea lamprey olfactory epithelium in a concentration dependent manner and showed detection thresholds between 10–13mol·L^(-1) and 10^(–11)mol·L^(-1)(paired t-test,P<0.05).Experiments in the two-choice maze showed that all isolated compounds induced behavioral responses in ovulated females.CONCLUSION The five novel compounds are likely additional components of pheromones released by sexually mature male sea lamprey,and may provide useful behavioral manipulation tools to be implemented with the integrated management of the destructive and invasive sea lamprey in the Laurentian Great Lakes.展开更多
Objective To evaluate atrial septal defect(ASD) occlusion employing a small right anterior thoracotomy approach. Methods A total of 21 patients with ASD underwent general anesthesia and 2-3 cm incision was made in the...Objective To evaluate atrial septal defect(ASD) occlusion employing a small right anterior thoracotomy approach. Methods A total of 21 patients with ASD underwent general anesthesia and 2-3 cm incision was made in the fourth right intercostal space.Utilizing transesophageal or transthoracic echocardiography,the occluder was released using a monotube unit. Results All patients were occluded successfully.No patient required open surgery utilizing extracorporeal circulation.There were no major complications and no evidence of residual atrial shunt. Conclusion ASD occlusion via a minimal surgical incision is safe,less invasive,and has excellent outcomes.展开更多
In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive...In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive sensing method,a flexural-hinged Stewart platform is designed as the flexible structure,and a straightforward optimization method considering the force and sensitivity isotropy of the sensor is proposed to determine geometric parameters which are best suited for the given external loads.The accuracy of this method is preliminarily discussed by finite element methods(FEMs).The sensor prototype is fabricated with the development of the electronic system.Calibration and dynamic loading tests for this sensor prototype are carried out.The working ranges of this sensor prototype are 30 N and 300 N·mm,and resolutions are 0.08 N in radial directions,0.25 N in axial direction,and 2.4 N·mm in rotational directions.It also exhibits a good capability for a typical dynamic force sensing at a frequency close to the normal heart rate of an adult.The sensor is compatible with surgical instruments for force feedback in RMIS.展开更多
Greenhouse horticultural production currently represents an important and growing sector of Canada's food and plant production systems. Since 2006,the value of greenhouse vegetable crops in Canada exceeds that of ...Greenhouse horticultural production currently represents an important and growing sector of Canada's food and plant production systems. Since 2006,the value of greenhouse vegetable crops in Canada exceeds that of field grown crops,signaling an important shift in the way food is cultivated in the country. While many factors have contributed to this change,a major area of innovation includes the discoveries and advances made in the development of commercial greenhouse production systems as well as the integration of biological control strategies for sustainable pest management. With this focus,this review offers a brief overview of the Canadian greenhouse industry,including a descriptive list of commonly used biological control organisms,as well as the role Canadian research has played in the development of these agents. We also address the threats that Canadian greenhouse producers face by invasive pests and the complications these have created for the commercialization of novel biological control agents. This information may serve as a guide for the development of parallel technologies and tools in other parts of the world where greenhouse production is expanding.展开更多
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(PCRRF19009)supported by Open Science Research Fund of State Key Laboratory of Pollution Control and Resource Reuse(Tongji University),ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,China。
文摘Understanding the impacts of co-invasion of multiple invaders on soil bacterial communities is significant in understanding the mechanisms driving successful invasion.This study aimed to determine the response of soil bacterial communities to co-invasion of two invaders daisy fleabane(Erigeron annuus)and Canada goldenrod(Solidago canadensis).Daisy fleabane and/or Canada goldenrod invasion significantly enhanced the operational taxonomic unit richness,Shannon index,and Chao1 index of soil bacterial communities.Canada goldenrod under light degree of invasion and co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree signally improved the ACE index of soil bacterial communities.Thus,the two invaders can enhance soil bacterial diversity and richness to facilitating subsequent invasion due to the fact that higher soil bacterial diversity and richness can enhance the levels of soil function and nutrients acquisition of plant species.ACE index of soil bacterial communities subjected to co-invasion of daisy fleabane and Canada goldenrod regardless of invasion degree was greater than that under the independent invasion of either daisy fleabane or Canada goldenrod.Hence,co-invasion of the two invaders can impose synergistic impacts on soil bacterial richness,which may build a preferable soil micro-environment via the intensified soil bacterial communities,which is contributive to their following invasion.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,ChinaProject(12JDG086)supported by Research Foundation for Advanced Talents of Jiangsu University,China
文摘Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject(Y20160023)supported by Open Science Research Fund of State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,China+1 种基金Project supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment
文摘Functional traits, specifically leaf functional traits, are core-topics to explore importance to the invasion success of invasive plant species. This study aims to address the differences in leaf functional traits and their corresponding variability of the invasive tree staghorn sumac Rhus typhina L. with different invasion success, including lower and higher invasion success, in two climatic regions in North China, including a warm temperate region and a cold temperate region. No significant differences were found for leaf functional traits of staghorn sumac across different invasion success. However, the variability of leaf chlorophyll and nitrogen concentrations of staghorn sumac under higher invasion success were approximately 66.023% and 68.615% higher than those under lower invasion success, respectively. The leaf chlorophyll and nitrogen concentrations of staghorn sumac in the warm temperate region were approximately 18.432% and 16.337% higher than those in cold temperate region, respectively. The variability of specific leaf area of staghorn sumac in warm temperate region was approximately 59.802% higher than that in cold temperate region. Accordingly, leaf chlorophyll and N concentrations as well as specific leaf area of staghorn sumac and their corresponding variability may play an essential role in shaping ecological success of studied invader along a climatic gradient.
基金Project(SS2012AA041601)supported by the National High Technology Research and Development Program of ChinaProject(81201150)supported by the National Natural Science Foundation of China
文摘In order to obtain the remote center motion(RCM) mechanism with better performance indexes and avoid the collision of multi-manipulators in minimally invasive surgery(MIS), a novel multi-objective optimization model was presented. There were two optimization objectives: a global kinematic performance index and a comprehensive stiffness index. Other indexes to characterize the design requirements such as collision probability, workspace, mechanism parameter, mass, and wall thickness were considered as constraints. Angles between two adjacent joints and cross-section dimensions of links were chosen as the design variables. The non-dominated sorting genetic algorithm II(NSGA-II) was adopted to solve the complex multi-objective optimization problem. Then, a 3-degree of freedom(DoF) MIS robotic prototype based on optimization results has been built up. The experiments to test the spatial position change of the remote center point and to test the absolute position accuracy and repetitive position accuracy of the MIS robot were achieved, and the experimental results meet the requirements of MIS.
基金The financial supports provided,in whole or in part,by the National Natural Science Foundation of China(11272083)the New Century Excellent Talents Program in Chinese Universities(NCET09-0263)
文摘Introduction Hematogenous metastasis is the mainly leading cause of death in breast carcinoma patients.A better understanding of the underlying molecular and cellular mechanisms is crucial for the development of effective treatment for metastatic breast cancer<sup>[</sup>1].It has been well established that cell adhesion and invasion is mediated by a variety of transmembrane proteins,including integrins,cadherins,selectins,and intercellular adhesion molecules.Among these adhesion molecules,the integrins and their downstream signaling pathways have been extensively studied<sup>[2]</sup>.On the other hand,the specific events determining tumor cell interactions with endo-
基金supported by the funds from Huazhong University of Science and TechnologyUS NIH grant GM072744
文摘Despite significant progress in cancer research during the past decades,yet there are no major breakthroughs that can be translated into major benefits for the general public in terms of treatment or therapy for the complex neoplastic diseases,especially for the malignant solid tumors.This depressing but indisputable fact leads to a call for new ideas to target tumor metastasis by editors of Nature Medicine<sup>[1]</sup>.The real problems are that the fundamental issues of transformation and malignancy in vivo are poorly understood.In a recent review on cancer,
文摘Aim Solasodine, a steroidal alkaloid isolated from solanaceous species, has been reported to exhibit anticancer activity on several cell lines. The aim of this study is to explore the antitumor potential of solasodine on ovarian cancer HEY cells. Methods MTT assay, Hoechst 33342 staining, JC-1 mitochondrial membrane potential assay, and LDH release assay were used to study the anti-proliferative and apoptosis-inducing effects of solasodine. MDC staining was to label the acidic puncta in the cells. Meanwhile, wound healing assay and transwell assay were performed to determine whether solasodine exhibits anti-metastasis effect on HEY cells. Gelatin zymography assay was used to determine the activities of MMP-2 and MMP-9 and Western blot was used to examine the expression of the relevant proteins. Results Solasodine inhibited the cell viability on HEY cells in time- and dose-dependent manners, causing shrinking of nuclei, damage of cell membrane, and appealing apoptotic body on high dosage and reducing cell mitochondrial membrane potential. It also inhibited autophagic flux that interfere autolysosome degra- dation. Furthermore, solasodine suppressed the migration and invasion abilities of HEY cells ascribable to down- regulating the expression and attenuating the activities of MMP-2 and MMP-9. Conclusion The inducing apoptosis and anti-metastasis activity of solasodine on HEY cells suggest it appears certain potential on ovarian cancer treat- ment.
基金Supported by the U.S.Army Corps of Engineers’Upper Mississippi River Restoration-Environmental Management Program’s Long Term Resource Monitoring component implemented by the U.S.Geological Survey,Upper Midwest Environmental Sciences Center and carried out by the Missouri Department of Conservation
文摘Silver carp Hypophthalmichthys molitrix were introduced into the U.S. to control water quality in aquaculture ponds. From this point of origin, silver carp escaped into nearby rivers through multiple flood events. Because of their documented negative effects on native biota, silver carp have been labeled as problematic. Therefore, evaluating the biology and ecology of these non-indigenous species is critical. Multiple parameters are needed to evaluate silver carp populations(length, weight, age, and sex). Furthermore, developing methods for rapidly acquiring these data are needed. In relation to sex determination, sexual dimorphism was observed where males exhibit distinct pectoral fin ray features. Specifically, males have pronounced ridges or a "rough patch" on the dorsal surface of pectoral fins. Therefore, to test if this was an applicable way of determining silver carp gender; silver carp were collected from Midwestern U.S. rivers(N=2015) in the fall of 2011(N=870), spring of 2012(N=645), winter of 2013—2014(N=202) and summer2015(N=323) via electrofishing. For each silver carp collected, presence(e.g., rough patch) or absence(e.g.,smooth) of pronounced ridges on the top side of the pectoral fins was recorded, and an incision was made in the body cavity to identify gender. Based on the results of our evaluation, gender was correctly identified over99% of the time(2006 out of 2015) based on the pectoral fin dimorphism. In the samples taken in the winter of 2013—2014 and summer of 2015, accuracy for silver carp shorter than 300 mm and longer than 800 mm was 53.7%(19 out of 41) while accuracy for silver carp between 300 mm and 800 mm total length was 98.9%(289 out of 292). This study provides a rapid assessment approach for evaluating silver carp gender.
文摘Objective This study aims to compare the grafts patency rate in triple-vessel disease between minimally invasive direct and the standard off-pump coronary artery bypass grafting.Methods Fifty patients who were hospitalized in Beijing ChaoYang Hospital during August 2013 to May 2015 were analyzed.MIDOPCABG group(n=25)underwent minimally invasive direct offpump coronary artery bypass grafting,and OPCABG group(n=25)underwent standard off-pump coronary artery bypass grafting group.
文摘OBJECTIVE The invasive sea lamprey(Petromyzon marinus)has devastated the ecosystem of the Laurentian Great Lakes.Application of pheromones to manipulate adult sea lamprey behavior is among the options considered for alternative sea lamprey control techniques.The male sea lamprey sex pheromone is hypothesized to be possess multiple functions through actions of multiple components,some of which have yet to be characterized.Our objective is to isolate and characterize the bioactive components from water conditioned with sexually mature male sea lamprey.METHODS The water conditioned with sexually mature male sea lamprey was extracted by solid phase extraction and concentrated in vacuo.The compounds were isolated by liquid chromatography and elucidated by spectrometry and spectroscopy.Their biological activities were evaluated by electro-olfactogram recordings and two-choice maze behavioral assays.RESULTS Five novel bile salts,petromyzene A and B and petromyzone A-C,have been characterized.Petromyzene A and B featured either a unique,rearranged side chain or a rare cis-11,12-diol on the steroidal B-ring.Petromyzone A-C represented three novel highly oxidized sulfated bile alcohols possessing different hydroxylation,oxidation,and double bond patterns,which exemplify the chemical diversity of bile salts.These five bile salts were potent odorants that stimulated the adult sea lamprey olfactory epithelium in a concentration dependent manner and showed detection thresholds between 10–13mol·L^(-1) and 10^(–11)mol·L^(-1)(paired t-test,P<0.05).Experiments in the two-choice maze showed that all isolated compounds induced behavioral responses in ovulated females.CONCLUSION The five novel compounds are likely additional components of pheromones released by sexually mature male sea lamprey,and may provide useful behavioral manipulation tools to be implemented with the integrated management of the destructive and invasive sea lamprey in the Laurentian Great Lakes.
文摘Objective To evaluate atrial septal defect(ASD) occlusion employing a small right anterior thoracotomy approach. Methods A total of 21 patients with ASD underwent general anesthesia and 2-3 cm incision was made in the fourth right intercostal space.Utilizing transesophageal or transthoracic echocardiography,the occluder was released using a monotube unit. Results All patients were occluded successfully.No patient required open surgery utilizing extracorporeal circulation.There were no major complications and no evidence of residual atrial shunt. Conclusion ASD occlusion via a minimal surgical incision is safe,less invasive,and has excellent outcomes.
基金Project(SS2012AA041601)supported by National High Technology Research and Development Program of ChinaProject(81201150)supported by the National Natural Science Foundation of China
文摘In order to restore force sensation to robot-assisted minimally invasive surgery(RMIS),design and performance evaluation of a miniature 6-axis force/torque sensor for force feedback is presented.Based on the resistive sensing method,a flexural-hinged Stewart platform is designed as the flexible structure,and a straightforward optimization method considering the force and sensitivity isotropy of the sensor is proposed to determine geometric parameters which are best suited for the given external loads.The accuracy of this method is preliminarily discussed by finite element methods(FEMs).The sensor prototype is fabricated with the development of the electronic system.Calibration and dynamic loading tests for this sensor prototype are carried out.The working ranges of this sensor prototype are 30 N and 300 N·mm,and resolutions are 0.08 N in radial directions,0.25 N in axial direction,and 2.4 N·mm in rotational directions.It also exhibits a good capability for a typical dynamic force sensing at a frequency close to the normal heart rate of an adult.The sensor is compatible with surgical instruments for force feedback in RMIS.
文摘Greenhouse horticultural production currently represents an important and growing sector of Canada's food and plant production systems. Since 2006,the value of greenhouse vegetable crops in Canada exceeds that of field grown crops,signaling an important shift in the way food is cultivated in the country. While many factors have contributed to this change,a major area of innovation includes the discoveries and advances made in the development of commercial greenhouse production systems as well as the integration of biological control strategies for sustainable pest management. With this focus,this review offers a brief overview of the Canadian greenhouse industry,including a descriptive list of commonly used biological control organisms,as well as the role Canadian research has played in the development of these agents. We also address the threats that Canadian greenhouse producers face by invasive pests and the complications these have created for the commercialization of novel biological control agents. This information may serve as a guide for the development of parallel technologies and tools in other parts of the world where greenhouse production is expanding.
