A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumpi...A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.展开更多
目的通过筛选脑膜瘤切除术患者术中输血的危险因素,建立相应的风险预测模型,指导临床备血及实施血液保护措施。方法回顾性分析2015年1月至2018年12月在福建医科大学附属第一医院行脑膜瘤切除术的585例患者的病历资料,采用单因素分析和Lo...目的通过筛选脑膜瘤切除术患者术中输血的危险因素,建立相应的风险预测模型,指导临床备血及实施血液保护措施。方法回顾性分析2015年1月至2018年12月在福建医科大学附属第一医院行脑膜瘤切除术的585例患者的病历资料,采用单因素分析和Logistic回归分析寻找术中输血的危险因素,建立风险预测模型。绘制受试者工作特征曲线(receiver operating characteristics curve,ROC),计算曲线下面积(area under the curve,AUC)。结果脑膜瘤患者术中输血136例,输血率为23.25%,其危险因素包括:肿瘤位于颅底(X1)、直径≥3.7 cm(X2)、累及重要血管(X3)(P<0.05)。患者术中输血的预测概率P=1/1+e^-Y,Y=-3.602+0.596X1+2.163X2+1.809X3。该预测模型的AUC为0.843±0.018(P<0.05)。结论肿瘤位于颅底、直径≥3.7 cm、累及重要血管是脑膜瘤切除术中输血的独立危险因素。展开更多
This paper reports the first universal and versatile database on aggregate materials for the field of aggregate science research.At the current stage,the database(http://119.91.135.188:8080/)contains over 1000 entries...This paper reports the first universal and versatile database on aggregate materials for the field of aggregate science research.At the current stage,the database(http://119.91.135.188:8080/)contains over 1000 entries of organic aggregate material systems(mainly luminescent systems at the current stage)with a unique data structure which is designed particularly for aggregate materials and containing the photophysics and physicochemical properties of the compounds in different statuses of aggregation,including dilute solution form,pristine solid-state,stable crystalline,and nanoaggregates formed in solvents.The web-based interface of the database provided functions to index,search,manipulate,fetch and deposit data entries.In addition,a background calculation service optimizes the chemical structure of new entries on different levels of accuracies.The database also provided background API for interactive developments of prediction or regression models based on machine-learning algorithms.展开更多
Ulcerative colitis （UC） is a chronic inflammatory bowel disease with continuous or recurrent symptoms. A 42-year-old male patient with intermittent diarrhea accompanied by bloody mucopurulent stools was admitted to ...Ulcerative colitis （UC） is a chronic inflammatory bowel disease with continuous or recurrent symptoms. A 42-year-old male patient with intermittent diarrhea accompanied by bloody mucopurulent stools was admitted to our hospital. The diagnosis of UC was confirmed by a combination of laboratory examination, colonoscopy, and histological assay. The patient developed herpes zoster in the hospital, which challenged traditional treatments. Therefore, we performed an autologous bone marrow cells to modulate the immune system with his permission. Autologous bone marrow mononuclear cells were collected and injected locally into the bowel mucosa, and subsequently injected systemically through a peripheral vein. After the patient underwent auto bone marrow mononuclear cells transplantations twice, the patient＇s symptoms were alleviated. Furthermore, he recovered from bematochezia, and his hypersensitive C reactive protein decreased. Colonoscopy results showed reduced lesions and decreased areas with bleeding and edema in the sigmoid colon and rectum. No recurrence occurred in the subsequent two years, but long-time monitoring is still necessary for the prophylaxis of colorectal cancer.展开更多
It is difficult to synthesize Al2O3/ZrO2 solid solution because of its low solubility under equilibrium solidification conditions.In this work,a new combustion synthesis combined with water atomization(CS-WA)method wa...It is difficult to synthesize Al2O3/ZrO2 solid solution because of its low solubility under equilibrium solidification conditions.In this work,a new combustion synthesis combined with water atomization(CS-WA)method was developed to prepare supersaturated Al2O3/ZrO2(CeO2)solid solution powders.The ultrahigh cooling rate supplied by CS-WA greatly extends solid solubility of Al2O3 in ZrO2.The precipitation mechanism of solid solution was investigated by systematic heat treatments.The initial temperature of the metastable phase decomposed into Al2O3 and ZrO2 is 1050℃,and it could be completely precipitated at 1400℃in 0.5 h.The precipitated ZrO2 particles were uniformly dispersed in Al2O3 matrix and grew into submicron scale at annealing temperature of 1450℃.Subsequently,together with detailed microstructure,phase composition,as well as mechanical properties were collaboratively outlined to discuss spark plasma sintering(SPS)behavior.The solid solution precipitated Al2O3 matrix and ZrO2 particles during the SPS process.Partial ZrO2 particles were uniformly distributed within Al2O3 matrix,while the residuary ZrO2 located at the grain boundaries and formed special transgranular/intergranular structure.The average size of nanoscale transgranular ZrO2 particles was only^11.5 nm.The compact ZrO2 toughened Al2O3 nano ceramic(N-ZTA)exhibits excellent mechanical properties.This work provides a guidance to produce nanostructured ZTA with high performance.展开更多
基金This work is financially supported by the National Natural Science Foundation of China （Grant No. 51075014）.
文摘A flexible-rigid hopping mechanism which is inspired by the locust jumping was proposed, and its kinematic characteris- tics were analyzed. A series of experiments were conducted to observe locust morphology and jumping process. According to classic mechanics, the jumping process analysis was conducted to build the relationship of the locust jumping parameters. The take-offphase was divided into four stages in detail. Based on the biological observation and kinematics analysis, a mechanical model was proposed to simulate locust jumping. The forces of the flexible-rigid hopping mechanism at each stage were ana- lyzed. The kinematic analysis using pseudo-rigid-body model was described by D-H method. It is confirmed that the proposed bionic mechanism has the similar performance as the locust hind leg in hopping. Moreover, the jumping angle which decides the jumping process was discussed, and its relation with other parameters was established. A calculation case analysis corroborated the method. The results of this paper show that the proposed bionic mechanism which is inspired by the locust hind limb has an excellent kinematics performance, which can provide a foundation for design and motion planning of the hopping robot.
文摘目的通过筛选脑膜瘤切除术患者术中输血的危险因素,建立相应的风险预测模型,指导临床备血及实施血液保护措施。方法回顾性分析2015年1月至2018年12月在福建医科大学附属第一医院行脑膜瘤切除术的585例患者的病历资料,采用单因素分析和Logistic回归分析寻找术中输血的危险因素,建立风险预测模型。绘制受试者工作特征曲线(receiver operating characteristics curve,ROC),计算曲线下面积(area under the curve,AUC)。结果脑膜瘤患者术中输血136例,输血率为23.25%,其危险因素包括:肿瘤位于颅底(X1)、直径≥3.7 cm(X2)、累及重要血管(X3)(P<0.05)。患者术中输血的预测概率P=1/1+e^-Y,Y=-3.602+0.596X1+2.163X2+1.809X3。该预测模型的AUC为0.843±0.018(P<0.05)。结论肿瘤位于颅底、直径≥3.7 cm、累及重要血管是脑膜瘤切除术中输血的独立危险因素。
基金the National Science Foundation of China,Grant/Award Numbers:21975077,52003228,21788102Shenzhen Key Laboratory of Functional Aggregate Materials,Grant/Award Number:ZDSYS20211021111400001+1 种基金the Science and Technology Plan of Shenzhen,Grant/Award Number:JCYJ2021324134613038Open Fund of Guangdong Provincial Key Laboratory of Luminescence from Molecular Aggregates,Grant/Award Number:2019B030301003。
文摘This paper reports the first universal and versatile database on aggregate materials for the field of aggregate science research.At the current stage,the database(http://119.91.135.188:8080/)contains over 1000 entries of organic aggregate material systems(mainly luminescent systems at the current stage)with a unique data structure which is designed particularly for aggregate materials and containing the photophysics and physicochemical properties of the compounds in different statuses of aggregation,including dilute solution form,pristine solid-state,stable crystalline,and nanoaggregates formed in solvents.The web-based interface of the database provided functions to index,search,manipulate,fetch and deposit data entries.In addition,a background calculation service optimizes the chemical structure of new entries on different levels of accuracies.The database also provided background API for interactive developments of prediction or regression models based on machine-learning algorithms.
基金The present study was financially supported by the State Science and Technology Support Program （No. 2012BAI37B04）, the Military Health Promotion Program （Nos. 10BJZ18 and 15BJZ41）, Beijing National Science Foundation of China （No. 5154035） and National Natural Science Foundation of China （Nos. 31600681, 81670496, 81402345, 81673873, and 21375133）.
文摘Ulcerative colitis （UC） is a chronic inflammatory bowel disease with continuous or recurrent symptoms. A 42-year-old male patient with intermittent diarrhea accompanied by bloody mucopurulent stools was admitted to our hospital. The diagnosis of UC was confirmed by a combination of laboratory examination, colonoscopy, and histological assay. The patient developed herpes zoster in the hospital, which challenged traditional treatments. Therefore, we performed an autologous bone marrow cells to modulate the immune system with his permission. Autologous bone marrow mononuclear cells were collected and injected locally into the bowel mucosa, and subsequently injected systemically through a peripheral vein. After the patient underwent auto bone marrow mononuclear cells transplantations twice, the patient＇s symptoms were alleviated. Furthermore, he recovered from bematochezia, and his hypersensitive C reactive protein decreased. Colonoscopy results showed reduced lesions and decreased areas with bleeding and edema in the sigmoid colon and rectum. No recurrence occurred in the subsequent two years, but long-time monitoring is still necessary for the prophylaxis of colorectal cancer.
基金financially supported by the National Natural Science Foundation of China(Nos.91016014 and 51872062).
文摘It is difficult to synthesize Al2O3/ZrO2 solid solution because of its low solubility under equilibrium solidification conditions.In this work,a new combustion synthesis combined with water atomization(CS-WA)method was developed to prepare supersaturated Al2O3/ZrO2(CeO2)solid solution powders.The ultrahigh cooling rate supplied by CS-WA greatly extends solid solubility of Al2O3 in ZrO2.The precipitation mechanism of solid solution was investigated by systematic heat treatments.The initial temperature of the metastable phase decomposed into Al2O3 and ZrO2 is 1050℃,and it could be completely precipitated at 1400℃in 0.5 h.The precipitated ZrO2 particles were uniformly dispersed in Al2O3 matrix and grew into submicron scale at annealing temperature of 1450℃.Subsequently,together with detailed microstructure,phase composition,as well as mechanical properties were collaboratively outlined to discuss spark plasma sintering(SPS)behavior.The solid solution precipitated Al2O3 matrix and ZrO2 particles during the SPS process.Partial ZrO2 particles were uniformly distributed within Al2O3 matrix,while the residuary ZrO2 located at the grain boundaries and formed special transgranular/intergranular structure.The average size of nanoscale transgranular ZrO2 particles was only^11.5 nm.The compact ZrO2 toughened Al2O3 nano ceramic(N-ZTA)exhibits excellent mechanical properties.This work provides a guidance to produce nanostructured ZTA with high performance.
