This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode,considering the vehicle’s inertial behavior.The comfort of riding in an automobile has b...This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode,considering the vehicle’s inertial behavior.The comfort of riding in an automobile has been evaluated in recent years on the basis of a subjective sensory evaluation given by the driver.However,reflecting driving sensations in design work to improve ride comfort is abstract in nature and difficult to express theoretically.Therefore,we evaluated the human body’s effects while driving scientifically by quantifying the driver’s behavior while operating the steering wheel and the behavior of the automobile while in motion using physical quantities.To this end,we collected driver and vehicle data using amotion capture system and vehicle CAN and IMU sensors.We also constructed a three-dimensional musculoskeletal mathematical model to simulate driver movements and calculate the power and amount of energy per unit of time used for driving the joints and muscles of the human body.Here,we used comfort mode and sport mode to compare damper characteristics in terms of hardness.In comfort mode,damper characteristics are soft and steering stability is mild,but vibration from the road is not easily transmitted to the driver making for a lighter load on the driver.In sport mode,on the other hand,damper characteristics are hard and steering stability is comparatively better.Still,vibration from the road is easily transmitted to the driver,whichmakes it easy for a load to be placed on the driver.As a result of this comparison,it was found that a load was most likely to be applied to the driver’s neck.This result in relation to the neck joint can therefore be treated as an objective measure for quantifying ride comfort.展开更多
The interactions of electromagnetic waves with the human body are complex and depend on several factors related to the characteristics of the incident wave, including its frequency, its intensity, the polarization of ...The interactions of electromagnetic waves with the human body are complex and depend on several factors related to the characteristics of the incident wave, including its frequency, its intensity, the polarization of the tissue encountered, the geometry of the tissue and its electromagnetic properties. That’s to say, the dielectric permittivity, the conductivity and the type of coupling between the field and the exposed body. A biological system irradiated by an electromagnetic wave is traversed by induced currents of non-negligible density;the water molecules present in the biological tissues exposed to the electromagnetic field will begin to oscillate at the frequency of the incident wave, thus creating internal friction responsible for the heating of the irradiated tissues. This heating will be all the more important as the tissues are rich in water. This article presents the establishment from a mathematical and numerical analysis explaining the phenomena of interaction and consequences between electromagnetic waves and health. Since the total electric field in the biological system is unknown, that is why it can be determined by the Finite Difference Time Domain FDTD method to assess the electromagnetic power distribution in the biological system under study. For this purpose, the detailed on the mechanisms of interaction of microwave electromagnetic waves with the human body have been presented. Mathematical analysis using Maxwell’s equations as well as bio-heat equations is the basis of this study for a consistent result. Therefore, a thermal model of biological tissues based on an electrical analogy has been developed. By the principle of duality, an electrical model in the dielectric form of a multilayered human tissue was used in order to obtain a corresponding thermal model. This thermal model made it possible to evaluate the temperature profile of biological tissues during exposure to electromagnetic waves. The simulation results obtained from computer tools show that the temperature in the biological tissue is a linear function of the duration of exposure to microwave electromagnetic waves.展开更多
Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like m...Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.展开更多
BACKGROUND: Human amniotic epithelial cells (HAECs) can differentiate into neurons, astrocytes and oligodendrocytes. They biologically secrete many active neurotrophins and have the capacity to metabolize dopamine ...BACKGROUND: Human amniotic epithelial cells (HAECs) can differentiate into neurons, astrocytes and oligodendrocytes. They biologically secrete many active neurotrophins and have the capacity to metabolize dopamine enzymes. These features underlie a theoretical basis for the treatment of Parkinson's disease (PD). OBJECTIVE: To investigate the survival and differentiation of transplanted HAECs in the lateral ventricle of PD model rats, and to explore its effect on circling behavior, as well as levels of dopamine (DA), the metabolite homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, and Shanghai Celstar Institute of Biotechnology from May 2007 to December 2008. MATERIALS: HAECs were derived from the placental chorion following caesarean delivery at the Shanghai International Matemal and Child Health Hospital. 6-hydroxydopamine (6-OHDA), and mouse anti-human Vimentin monoclonal antibody were purchased from Sigma, USA; mouse anti-human nestin and tyrosine hydroxylase (TH) monoclonal antibodies were purchased from Chemicon, USA. METHODS: A total of 114 healthy, adult, Sprague Dawley rats were randomly assigned to two groups: PD model [n = 90, stereotactic microinjection of 2 μL 6-OHDA (3.5 μg/uL) into the striatum] and control (n = 24, no treatment). The 51 successful PD model rats were randomly divided into 3 subgroups (n = 17): HAEC, PBS, and model. The HAEC and PBS groups were respectively injected with 10 μL PBS solution containing 1 × 10^5/mL HAECs or 10 pL PBS into the lateral ventricle. The model group was not treated. MAIN OUTCOME MEASURES: TH protein expression in the striatum was evaluated by immunohistochemistry 5 weeks after HAEC transplantation. At 10 weeks, HAEC survival in the lateral ventricle was investigated by immunofluorescent staining; differentiation of HAECs in the lateral and third ventricles was examined by TH immunohistochemistry; concentrations of DA, homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum, as well as DA concentration in the cerebrospinal fluid, were measured with high-performance liquid chromatography-electrochemical detection. Circling behavior of PD model rats was consecutively observed for 10 weeks following intraperitoneal injection of amphetamine 1 week after successful model establishment. RESULTS: tn the HAEC group, the number of TH-positive cells significantly increased in the striatum, and circling behavior significantly decreased, compared with the PBS and model groups (P 〈 0.01). In addition, monoamine concentrations in the striatum, as well as DA concentrations in the cerebrospinal fluid, significantly increased, compared with the PBS group (P 〈 0.05-0.01). Moreover, a large number of nestin-, vimentin-, and TH-positive cells were observed in the lateral and third ventricles following HAEC injection.CONCLUSION: HAECs survived for 10 weeks with no overgrowth following transplantation into the lateral ventricle of PD model rats. Moreover, the cells differentiated into dopaminergic neurons, which increased DA secretion. HAEC transplantation improved cycling behavior in PD model rats.展开更多
AIM: To establish a relevant animal model of human gastrointestinal cancer, which can be used for repetitive investigations, so as to improve our understanding and management of carcinogenesis and cancer metastasis. M...AIM: To establish a relevant animal model of human gastrointestinal cancer, which can be used for repetitive investigations, so as to improve our understanding and management of carcinogenesis and cancer metastasis. METHODS: Intact tissues of human colorectal and pancreatic cancers were transplanted in nude mice. The biological characteristics of the original and the corresponding transplanted tumors were investigated by HE staining, PAS staining and immunostaining. The metastases in the livers and lungs of nude mice were investigated by immunostaining with biotinylated mab KL-1 and by RT-PCR using CK20 specific primers. RESULTS: There were totally 9 of 16 surgical specimens growing in nude mice subcutaneously and/or orthotopically (4 of 6 colorectal and 5 of 10 pancreatic cancer). Tumor cell content of the specimens and freezing of tissue specimens are important factors influencing the growth of transplanted tumor. In the group of fresh tumor tissues with greater than 50% tumor cell content, the success rate of the transplantation was 100% (3 cases of pancreatic cancer and 3 cases of colorectal cancer). The orthotopically trans-planted tumors resemble the original tumor morphologically and biologically, including TAA expression such as CEA by immunohistochemistry, and CEA level in the serum of mice. Ki-67 labeling index and the expression of TAA especially K-ras, 17-1A and RA-96, are associated with the potential of tumor growth in nude mice. Micrometastases in the lungs and livers of tumor bearing mice can be detected by immunostaining with biotinylated mab KL-1 and CK20-specific RT-PCR. CONCLUSION: An orthotopic transplantation model for human colon and pancreatic cancer in nude mice has been set up. We have also established sensitive detection methods with CK-immunohistochemistry and CK20-RT-PCR to study xenotransplanted human cancer and its metastatic cancer cells in the liver and lung of nude mice. This study may be helpful in understanding the mechanism of cancer metastasis and in developing new diagnostic methods and therapeutic strategies for metastases including micrometastases.展开更多
The traditional human comfort meter has the following defects: the interface is not uniform;the operation is cumbersome and complicated;the interface is unfriendly, and the stability and adaptability are poor. This pa...The traditional human comfort meter has the following defects: the interface is not uniform;the operation is cumbersome and complicated;the interface is unfriendly, and the stability and adaptability are poor. This paper presents a design scheme for human comfort instrument based on embedded system, using S3C2440 embedded development board and the sensors to collect the real-time temperature, relative humidity and wind speed data and to process the collecting data;then obtaining the human body comfort value according to the basic algorithm of human body comfort instrument;giving the human comfort conclusion according to the diastolic index range of human comfort, and showing the temperature and humidity, wind speed, comfort value and conclusion through writing the Qt graphical user interface program. At the same time, the human comfort instrument has the data storage function. The human comfort instrument is high in integration, strong in real time, high in sensitivity, stable and reliable, and it meets the development goals of the intelligent meteorological service, and meets the demand of the meteorological service that is closer to life, and it has broad development prospect.展开更多
The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. Thi...The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities (aerobics). The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS (root mean square) accelerations and VDV (vibration dose value) values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.展开更多
In view of the learners Chinglish,this paper puts forward a new teaching model-the Self-correction Model and makes an analysis of it from the view of cognitive psychology.
The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal en...The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the Yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.展开更多
AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression. METHODS: Tolerance towards human...AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression. METHODS: Tolerance towards human hepatocytes was established by injection of primary human hepatocytes or Huh7 human hepatoma cells into the peritoneal cavities of fetal rats. Corresponding cells were subsequently transplanted into newborn rats via intrasplenic injection within 24h after birth. RESULTS: Mixed lymphocyte assays showed that spleen cells from non-tolerized rats were stimulated to proliferate when exposed to human hepatocytes, while cells from tolerized rats were not. Injections made between 15 d and 17 d of gestation produced optimal tolerization. Transplanted human hepatocytes in rat livers were visualized by immunohistochemical staining of human albumin. By dot blotting of genomic DNA in livers of tolerized rats 16 weeks after hepatocyte transplantation, it was found that approximately 2.5 X 10(5) human hepatocytes survived per rat liver. Human albumin mRNA was detected in rat livers by RT-PCR for 15 wk, and human albumin protein was also detectable in rat serum. CONCLUSION: Tolerization of an immuno-competent rat can permit transplantation, and survival of functional human hepatocytes.展开更多
人体热调节模型在“人体-服装-环境”系统的热湿传递机理研究中具有非常重要的作用,一直是传热传质学、生理学、工效学、纺织服装、建筑与环境等多学科交叉研究的重点。利用CiteSpace软件,从文献计量学的角度对Web of Science核心合辑...人体热调节模型在“人体-服装-环境”系统的热湿传递机理研究中具有非常重要的作用,一直是传热传质学、生理学、工效学、纺织服装、建筑与环境等多学科交叉研究的重点。利用CiteSpace软件,从文献计量学的角度对Web of Science核心合辑收录的499篇有关人体热调节模型的研究论文进行数据可视化处理和分析。研究结果表明:东华大学、中国香港理工大学、清华大学是本领域的高产机构;Fiala模型、JOS模型和Gagge模型是近年来引用最多的热调节模型;我国热调节模型相关研究文献发表数位居世界第二,但因起步较晚,应用型研究较多,原创性热调节模型少,国际影响力较弱;计算流体力学和人工神经网络逐渐成为近几年的研究热点。展开更多
操纵舒适性是人机系统研究的重要内容之一。针对操纵舒适性评价的不确定性和模糊性,构建基于贝叶斯的多核回声状态网络(Echo state network,ESN)模型,对站立姿态下的操纵舒适性进行评价。通过实验,收集不同操纵位置对用户的舒适性影响...操纵舒适性是人机系统研究的重要内容之一。针对操纵舒适性评价的不确定性和模糊性,构建基于贝叶斯的多核回声状态网络(Echo state network,ESN)模型,对站立姿态下的操纵舒适性进行评价。通过实验,收集不同操纵位置对用户的舒适性影响。15名被试者参与了本次实验,每个被试者需要完成100个操纵任务,实验过程中被试者的操纵姿势、目标位置、脚底压力、被试人体尺寸和主观舒适性的数据将被记录下来。选取了10%的实验数据对所提出的方法进行了验证,并与BP神经网络预测模型进行比较,结果表明T-S FNN模型具有较小的均方根误差。最后随机选取了10组操纵任务与快速上肢评估方法(RULA)进行比较,结果表明该方法和实际值相关性系数为0.97(p<0.05),与RULA结果的相关性为0.66(p<0.05),说明该方法能够较好地反应真实结果。展开更多
文摘This research aims to quantify driver ride comfort due to changes in damper characteristics between comfort mode and sport mode,considering the vehicle’s inertial behavior.The comfort of riding in an automobile has been evaluated in recent years on the basis of a subjective sensory evaluation given by the driver.However,reflecting driving sensations in design work to improve ride comfort is abstract in nature and difficult to express theoretically.Therefore,we evaluated the human body’s effects while driving scientifically by quantifying the driver’s behavior while operating the steering wheel and the behavior of the automobile while in motion using physical quantities.To this end,we collected driver and vehicle data using amotion capture system and vehicle CAN and IMU sensors.We also constructed a three-dimensional musculoskeletal mathematical model to simulate driver movements and calculate the power and amount of energy per unit of time used for driving the joints and muscles of the human body.Here,we used comfort mode and sport mode to compare damper characteristics in terms of hardness.In comfort mode,damper characteristics are soft and steering stability is mild,but vibration from the road is not easily transmitted to the driver making for a lighter load on the driver.In sport mode,on the other hand,damper characteristics are hard and steering stability is comparatively better.Still,vibration from the road is easily transmitted to the driver,whichmakes it easy for a load to be placed on the driver.As a result of this comparison,it was found that a load was most likely to be applied to the driver’s neck.This result in relation to the neck joint can therefore be treated as an objective measure for quantifying ride comfort.
文摘The interactions of electromagnetic waves with the human body are complex and depend on several factors related to the characteristics of the incident wave, including its frequency, its intensity, the polarization of the tissue encountered, the geometry of the tissue and its electromagnetic properties. That’s to say, the dielectric permittivity, the conductivity and the type of coupling between the field and the exposed body. A biological system irradiated by an electromagnetic wave is traversed by induced currents of non-negligible density;the water molecules present in the biological tissues exposed to the electromagnetic field will begin to oscillate at the frequency of the incident wave, thus creating internal friction responsible for the heating of the irradiated tissues. This heating will be all the more important as the tissues are rich in water. This article presents the establishment from a mathematical and numerical analysis explaining the phenomena of interaction and consequences between electromagnetic waves and health. Since the total electric field in the biological system is unknown, that is why it can be determined by the Finite Difference Time Domain FDTD method to assess the electromagnetic power distribution in the biological system under study. For this purpose, the detailed on the mechanisms of interaction of microwave electromagnetic waves with the human body have been presented. Mathematical analysis using Maxwell’s equations as well as bio-heat equations is the basis of this study for a consistent result. Therefore, a thermal model of biological tissues based on an electrical analogy has been developed. By the principle of duality, an electrical model in the dielectric form of a multilayered human tissue was used in order to obtain a corresponding thermal model. This thermal model made it possible to evaluate the temperature profile of biological tissues during exposure to electromagnetic waves. The simulation results obtained from computer tools show that the temperature in the biological tissue is a linear function of the duration of exposure to microwave electromagnetic waves.
基金Partly supporled by the State Key Basic Research Program Grant of China(G1998051211)Leading Speciality Grant of Shanghai Health Bureau.
文摘Metastatic human HCC model is needed for the studies on mechanism and intervention of metastatic recurrence. By using orthotopic implantation of histologically intact tissues of 30 surgical specimens, a patient-like metastatic model of human HCC in nude mice (LCI-D20) and a low metastatic model of human HCC in nude mice (LCI-D35) have been established. All mice with transplanted LCI-D20 tumors exhibited extremely high metastatic ability including spontaneous metastasis to liver, lungs, lymph nodes and peritoneal seeding. Remarkable difference was also found in expression of some of the invasiveness related genes and growth factors between the LCI-D20 and LCI-D35 tumors. PAI-1 increased gradually following tumor progression in LCI-D20 model, and correlated with tumor size and AFP level. Phasic expression of tissue intercellular adhesion molecule-1 in this model was also observed. Using corneal micropocket model, it was demonstrated that the vascular response induced by LCI-D20 tumor was stronger than that induced by LCI-D35 tumor. Similar report on metastatic human HCC model in nude mice and human HCC cell line with metastatic potential was rarely found in the literature. This LCI-D20 model has been widely used for the studies on intervention of metastasis, including anti-angiogenesis,antisense approach, metalloproteinase inhibitor, differentiation inducer, etc. It is concluded that the establishment of metastatic human HCC model in nude mice and human HCC cell line with metastatic potential will provide important models for the in vitro and in vitro study of HCC invasiveness, angiogenesis as well as intervention of HCC recurrence.
基金Supported by: the Major State Basic Research Development Program of China (973 Program), No.2005CB522604the National Natural Science Foundation of China, No. 30271325
文摘BACKGROUND: Human amniotic epithelial cells (HAECs) can differentiate into neurons, astrocytes and oligodendrocytes. They biologically secrete many active neurotrophins and have the capacity to metabolize dopamine enzymes. These features underlie a theoretical basis for the treatment of Parkinson's disease (PD). OBJECTIVE: To investigate the survival and differentiation of transplanted HAECs in the lateral ventricle of PD model rats, and to explore its effect on circling behavior, as well as levels of dopamine (DA), the metabolite homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Institute of Biochemistry and Cell Biology, Shanghai Institute for Biological Sciences, Chinese Academy of Sciences, and Shanghai Celstar Institute of Biotechnology from May 2007 to December 2008. MATERIALS: HAECs were derived from the placental chorion following caesarean delivery at the Shanghai International Matemal and Child Health Hospital. 6-hydroxydopamine (6-OHDA), and mouse anti-human Vimentin monoclonal antibody were purchased from Sigma, USA; mouse anti-human nestin and tyrosine hydroxylase (TH) monoclonal antibodies were purchased from Chemicon, USA. METHODS: A total of 114 healthy, adult, Sprague Dawley rats were randomly assigned to two groups: PD model [n = 90, stereotactic microinjection of 2 μL 6-OHDA (3.5 μg/uL) into the striatum] and control (n = 24, no treatment). The 51 successful PD model rats were randomly divided into 3 subgroups (n = 17): HAEC, PBS, and model. The HAEC and PBS groups were respectively injected with 10 μL PBS solution containing 1 × 10^5/mL HAECs or 10 pL PBS into the lateral ventricle. The model group was not treated. MAIN OUTCOME MEASURES: TH protein expression in the striatum was evaluated by immunohistochemistry 5 weeks after HAEC transplantation. At 10 weeks, HAEC survival in the lateral ventricle was investigated by immunofluorescent staining; differentiation of HAECs in the lateral and third ventricles was examined by TH immunohistochemistry; concentrations of DA, homovanillic acid, dihydroxyphenyl acetic acid, 5-hydroxyindoleacetic acid, and 5-hydroxytryptamine in the striatum, as well as DA concentration in the cerebrospinal fluid, were measured with high-performance liquid chromatography-electrochemical detection. Circling behavior of PD model rats was consecutively observed for 10 weeks following intraperitoneal injection of amphetamine 1 week after successful model establishment. RESULTS: tn the HAEC group, the number of TH-positive cells significantly increased in the striatum, and circling behavior significantly decreased, compared with the PBS and model groups (P 〈 0.01). In addition, monoamine concentrations in the striatum, as well as DA concentrations in the cerebrospinal fluid, significantly increased, compared with the PBS group (P 〈 0.05-0.01). Moreover, a large number of nestin-, vimentin-, and TH-positive cells were observed in the lateral and third ventricles following HAEC injection.CONCLUSION: HAECs survived for 10 weeks with no overgrowth following transplantation into the lateral ventricle of PD model rats. Moreover, the cells differentiated into dopaminergic neurons, which increased DA secretion. HAEC transplantation improved cycling behavior in PD model rats.
基金Supported by the German Foundation"Hensel-Stiftung"and Foundation of Health Ministry of China,No.D39901
文摘AIM: To establish a relevant animal model of human gastrointestinal cancer, which can be used for repetitive investigations, so as to improve our understanding and management of carcinogenesis and cancer metastasis. METHODS: Intact tissues of human colorectal and pancreatic cancers were transplanted in nude mice. The biological characteristics of the original and the corresponding transplanted tumors were investigated by HE staining, PAS staining and immunostaining. The metastases in the livers and lungs of nude mice were investigated by immunostaining with biotinylated mab KL-1 and by RT-PCR using CK20 specific primers. RESULTS: There were totally 9 of 16 surgical specimens growing in nude mice subcutaneously and/or orthotopically (4 of 6 colorectal and 5 of 10 pancreatic cancer). Tumor cell content of the specimens and freezing of tissue specimens are important factors influencing the growth of transplanted tumor. In the group of fresh tumor tissues with greater than 50% tumor cell content, the success rate of the transplantation was 100% (3 cases of pancreatic cancer and 3 cases of colorectal cancer). The orthotopically trans-planted tumors resemble the original tumor morphologically and biologically, including TAA expression such as CEA by immunohistochemistry, and CEA level in the serum of mice. Ki-67 labeling index and the expression of TAA especially K-ras, 17-1A and RA-96, are associated with the potential of tumor growth in nude mice. Micrometastases in the lungs and livers of tumor bearing mice can be detected by immunostaining with biotinylated mab KL-1 and CK20-specific RT-PCR. CONCLUSION: An orthotopic transplantation model for human colon and pancreatic cancer in nude mice has been set up. We have also established sensitive detection methods with CK-immunohistochemistry and CK20-RT-PCR to study xenotransplanted human cancer and its metastatic cancer cells in the liver and lung of nude mice. This study may be helpful in understanding the mechanism of cancer metastasis and in developing new diagnostic methods and therapeutic strategies for metastases including micrometastases.
文摘The traditional human comfort meter has the following defects: the interface is not uniform;the operation is cumbersome and complicated;the interface is unfriendly, and the stability and adaptability are poor. This paper presents a design scheme for human comfort instrument based on embedded system, using S3C2440 embedded development board and the sensors to collect the real-time temperature, relative humidity and wind speed data and to process the collecting data;then obtaining the human body comfort value according to the basic algorithm of human body comfort instrument;giving the human comfort conclusion according to the diastolic index range of human comfort, and showing the temperature and humidity, wind speed, comfort value and conclusion through writing the Qt graphical user interface program. At the same time, the human comfort instrument has the data storage function. The human comfort instrument is high in integration, strong in real time, high in sensitivity, stable and reliable, and it meets the development goals of the intelligent meteorological service, and meets the demand of the meteorological service that is closer to life, and it has broad development prospect.
文摘The current steel-concrete composite floors design might be susceptible to the resonance phenomenon, causing undesirable vibrations in the frequency range that is the most noticeable to humans, i.e., 4 Hz to 8 Hz. This way, the main objective of this work is to investigate the dynamic structural behaviour of a steel-concrete composite multi-storey building when subjected to human rhythmic activities (aerobics). The studied structural model represents a typical interior floor bay of a commercial building used for gym and is composed by three floor levels spanning 20 m by 20 m, with a total area of 3×400 m2. An extensive parametric study was developed aiming to obtain the peak accelerations, RMS (root mean square) accelerations and VDV (vibration dose value) values, based on two different mathematical formulations. The human comfort of the building was analysed and the vibration transmissibility related to the steel columns was verified. Based on the found results, the investigated structural model presented high vibration levels that compromise the human comfort.
文摘In view of the learners Chinglish,this paper puts forward a new teaching model-the Self-correction Model and makes an analysis of it from the view of cognitive psychology.
基金Supported by the National Natural Science Foundation of China (42021004 and 42175032)。
文摘The combined effects of global warming and the urban heat islands exacerbate the risk of urban heat stress. It is crucial to implement effective cooling measures in urban areas to improve the comfort of the thermal environment. In this study, the Weather Research and Forecasting Model(WRF), coupled with a single-layer Urban Canopy Model(UCM), was used to study the impact of heat mitigation strategies. In addition, a 5-km resolution land-cover dataset for China(ChinaLC), which is based on satellite remote sensing data, was adjusted and used, and 18 groups of numerical experiments were designed, to increase the albedo and vegetation fraction of roof/ground parameters. The experiments were conducted for four heatwave events that occurred in the summer of 2013 in the Yangtze River Delta urban agglomeration of China. The simulated results demonstrated that, for the single roof/ground schemes, the mitigation effects were directly proportional to the albedo and greening. Among all the experimental schemes, the superposed schemes presented better cooling effects. For the ground greening scheme, with similar net radiation flux and latent heat flux, its storage heat was lower than that of the roof greening scheme, resulting in more energy flux into the atmosphere, and its daytime cooling effect was not as good as that of the roof greening scheme. In terms of human thermal comfort(HTC), the improvement achieved by the ground greening scheme was better than any other single roof/ground schemes, because the increase in the relative humidity was small. The comprehensive evaluation of the mitigation effects of different schemes on the thermal environment presented in this paper provides a theoretical basis for improving the urban environment through rational urban planning and construction.
文摘AIM: To determine whether normal genetically immunocompetent rodent hosts could be manipulated to accept human hepatocyte transplants with long term survival without immunosuppression. METHODS: Tolerance towards human hepatocytes was established by injection of primary human hepatocytes or Huh7 human hepatoma cells into the peritoneal cavities of fetal rats. Corresponding cells were subsequently transplanted into newborn rats via intrasplenic injection within 24h after birth. RESULTS: Mixed lymphocyte assays showed that spleen cells from non-tolerized rats were stimulated to proliferate when exposed to human hepatocytes, while cells from tolerized rats were not. Injections made between 15 d and 17 d of gestation produced optimal tolerization. Transplanted human hepatocytes in rat livers were visualized by immunohistochemical staining of human albumin. By dot blotting of genomic DNA in livers of tolerized rats 16 weeks after hepatocyte transplantation, it was found that approximately 2.5 X 10(5) human hepatocytes survived per rat liver. Human albumin mRNA was detected in rat livers by RT-PCR for 15 wk, and human albumin protein was also detectable in rat serum. CONCLUSION: Tolerization of an immuno-competent rat can permit transplantation, and survival of functional human hepatocytes.
文摘人体热调节模型在“人体-服装-环境”系统的热湿传递机理研究中具有非常重要的作用,一直是传热传质学、生理学、工效学、纺织服装、建筑与环境等多学科交叉研究的重点。利用CiteSpace软件,从文献计量学的角度对Web of Science核心合辑收录的499篇有关人体热调节模型的研究论文进行数据可视化处理和分析。研究结果表明:东华大学、中国香港理工大学、清华大学是本领域的高产机构;Fiala模型、JOS模型和Gagge模型是近年来引用最多的热调节模型;我国热调节模型相关研究文献发表数位居世界第二,但因起步较晚,应用型研究较多,原创性热调节模型少,国际影响力较弱;计算流体力学和人工神经网络逐渐成为近几年的研究热点。
文摘操纵舒适性是人机系统研究的重要内容之一。针对操纵舒适性评价的不确定性和模糊性,构建基于贝叶斯的多核回声状态网络(Echo state network,ESN)模型,对站立姿态下的操纵舒适性进行评价。通过实验,收集不同操纵位置对用户的舒适性影响。15名被试者参与了本次实验,每个被试者需要完成100个操纵任务,实验过程中被试者的操纵姿势、目标位置、脚底压力、被试人体尺寸和主观舒适性的数据将被记录下来。选取了10%的实验数据对所提出的方法进行了验证,并与BP神经网络预测模型进行比较,结果表明T-S FNN模型具有较小的均方根误差。最后随机选取了10组操纵任务与快速上肢评估方法(RULA)进行比较,结果表明该方法和实际值相关性系数为0.97(p<0.05),与RULA结果的相关性为0.66(p<0.05),说明该方法能够较好地反应真实结果。