The application of fiber reinforced plastic（FRP）,including carbon FRP and glass FRP,for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally b...The application of fiber reinforced plastic（FRP）,including carbon FRP and glass FRP,for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement（EBR） and near-surface mounted（NSM） strengthening techniques.This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods,including externally-bonded and near-surface mounted FRP,to study the strain coordination of the FRP and steel rebar of the RC beam.Since there is relative slipping between the RC beam and the FRP,the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis;that is,the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height（h 0） of the cross section is in direct proportion to the distance from the fiber to the neutral axis.The strain of the FRP and steel rebar satisfies the equation：ε FRP =βε steel,and the value of β is equal to 1.1-1.3 according to the test results.展开更多
Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin...Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.展开更多
Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and funct...Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.展开更多
基金Consultative Program of the Chinese Academy of Engineeringthe foundation for Excellent Young of Hunan Scientific Committee+1 种基金the National Natural Science Foundation of Hunan Provincethe Science and Research Program of Hunan Province
文摘The application of fiber reinforced plastic（FRP）,including carbon FRP and glass FRP,for structural repair and strengthening has grown due to their numerous advantages over conventional materials such as externally bonded reinforcement（EBR） and near-surface mounted（NSM） strengthening techniques.This paper summarizes the results from 21 reinforced concrete beams strengthened with different methods,including externally-bonded and near-surface mounted FRP,to study the strain coordination of the FRP and steel rebar of the RC beam.Since there is relative slipping between the RC beam and the FRP,the strain of the FRP and steel rebar of the RC beam satisfy the quasi-plane-hypothesis;that is,the strain of the longitudinal fiber that parallels the neutral axis of the plated beam within the scope of the effective height（h 0） of the cross section is in direct proportion to the distance from the fiber to the neutral axis.The strain of the FRP and steel rebar satisfies the equation：ε FRP =βε steel,and the value of β is equal to 1.1-1.3 according to the test results.
基金supported by the National Basic Research Program of China(Grant No.2007CB947704)the National High Technology Research and Development Program of China(Grant Nos. 2006AA02A112 and 2006AA02A116)High Level Talent Fund of the Beijing Healthcare System(Grant No.2009-2-14)
文摘Juvenile （2-3 years old） cynomolgus monkeys are frequently used as recipients in non-human primate islet transplantation studies. The aim of this study was to examine the effects of different doses of streptozotocin （STZ）, and find the optimal dose for inducing diabetes in these monkeys. Fifteen juvenile （2-3 years old） cynomolgus monkeys were separated into three groups and administered with different doses of STZ （100, 68 or 60 mg kg-l）. Basal and glucose-stimulated blood glucose, in- sulin, and C-peptide levels, as well as body weights were monitored. Hepatic and renal function tests and pancreatic immuno- histochemistry were performed before and after STZ treatment. Monkeys treated with both 100 and 68 mg kg-1 of STZ exhib- ited continuous hyperglycemia, which coincided with a nearly complete loss of islet 13-cells. Two monkeys received 60 mg kg-1 of STZ, but only one became completely diabetic. During the first week following STZ treatment, hepatic and renal func- tion slightly increased in these three groups. However. 24 hours post-STZ, serum total bile acid levels were significantly in- creased in monkeys treated with 100 mg kg-1 than those treated with 68 mg kg-I of STZ （P〈0.05）. These data suggest that 100 mg kg-1 and 68 mg kg-1 of STZ can safely induce diabetes in cynomolgus monkeys aged 2-3 years, but 68 mg kg-1 of STZ, rather than 100 mg kg-1 of STZ, may be more appropriate for inducing diabetes in these monkeys. Furthermore, body surface area, rather than body weight, was a more reliable determinant of dosage, where 700 mg m-2 of STZ should be the lower limit for inducing diabetes in juvenile monkeys.
基金supported by the National Basic Research Program of China (Grant No. 2007CB947704)Research Assistance Fund of Anhui Medical University (Grant No. XJ201008)
文摘Recently,transplantation of allogeneic and autologous cells has been used for regenerative medicine.A critical issue is monitoring migration and homing of transplanted cells,as well as engraftment efficiency and functional capability in vivo.Monitoring of superparamagnetic iron oxide(SPIO) particles by magnetic resonance imaging(MRI) has been used in animal models and clinical settings to track labeled cells.A major limitation of MRI is that the signals do not show biological characteristics of transplanted cells in vivo.Bone marrow mesenchymal stem cells(MSCs) have been extensively investigated for their various therapeutic properties,and exhibit the potential to differentiate into cells of diverse lineages.In this study,cynomolgus monkey MSCs(cMSCs) were labeled with Molday ION Rhodamine-BTM(MIRB),a new SPIO agent,to investigate and characterize the biophysical and MRI properties of labeled cMSCs in vitro and in vivo.The results indicate that MIRB is biocompatible and useful for cMSCs labeling and cell tracking by multimodality imaging.Our method is helpful for detection of transplanted stem cells in vivo,which is required for understanding mechanisms of cell therapy.
