Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 fo...Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 for both the control and treated group), and the structural indices of the lumbar vertebral (LI and L2) trabecular bone were assessed directly from 3-D images.Results. Treatment with alendronate increased bone volume fraction by 9. 5% and 7. 7% in L1 and L2 respectively. Trabecular thickness significantly increased after alendronate treatment, whereas trabecular separation remained constant. The degree of anisotropy for the alendronate - treated group was decreased compared with that of the control group. Bone surface to volume ratio declined significantly in the alendronate-reated group, whereas alendronate induced a higher bone surface density.Conclusion. Alendronate increased the structural properties of canine trabecular bone after short-term treatment at a dose of 0. 5 mg · kg-1·day-1.展开更多
AIM： To investigate the response of astrocytes and neurons in rat lumbo±sacral spinal cord and medulla oblongata induced by chronic colonic inflammation, and the relationship between them. METHODS： Thirty-three...AIM： To investigate the response of astrocytes and neurons in rat lumbo±sacral spinal cord and medulla oblongata induced by chronic colonic inflammation, and the relationship between them. METHODS： Thirty-three male Sprague-Dawley rats were randomly divided into two groups： experimental group （n = 17）, colonic inflammation was induced by intra-luminal administration of trinitrobenzenesulfonic acid （TNBS）; control group （n = 16）, saline was administered intra-luminally. After 3, 7, 14, and 28 d of administration, the lumbo-sacral spinal cord and medulla oblongata were removed and processed for anti-glial fibrillary acidic protein （GFAP）, Fos and GFAP/Fos immunohistochemistry. RESULTS： Activated astrocytes positive for GFAP were mainly distributed in the superficial laminae （laminae Ⅰ-Ⅱ） of dorsal horn, intermediolateral nucleus （laminae Ⅴ）, posterior commissural nucleus （laminae Ⅹ） and anterolateral nucleus （laminae Ⅸ）. Fos-IR （Fos-immunoreactive） neurons were mainly distributed in the deeper laminae of the spinal cord （laminae Ⅲ-Ⅳ, Ⅴ-Ⅵ）. In the medulla oblongata, both GFAP-IR astrocytes and Fos-IR neurons were mainly distributed in the medullary visceral zone （MVZ）. The density of GFAP in the spinal cord of experimental rats was significantly higher after 3, 7, and 14 d of TNBS administration compared with the controls （50.44±16.8, 29.24±6.5, 24.14±5.6, P〈0.05）. The density of GFAP in MVZ was significantly higher after 3 d of TNBS administration （34.34±2.5, P〈0.05）. After 28 d of TNBS administration, the density of GFAP in the spinal cord and MVZ decreased and became comparable to that of the controls （18.04±4.9, 14.64±6.4, P〉0.05）. CONCLUSION： Astrocytes in spinal cord and medulla oblongata can be activated by colonic inflammation. The activated astrocytes are closely related to Fos-IR neurons. With the recovery of colonic inflammation, the activity ofastrocytes in the spinal cord and medulla oblongata is reduced.展开更多
The functional piezoelectric ceramic smart aggregate(SA) sensors and actuators,based on piezoelectric ceramic materials such as lead zirconium titanate(PZT),were embedded into the reinforced concrete beams with three-...The functional piezoelectric ceramic smart aggregate(SA) sensors and actuators,based on piezoelectric ceramic materials such as lead zirconium titanate(PZT),were embedded into the reinforced concrete beams with three-point bending under static loading for purposes of damage detection.The SA actuators generated the desired sine sweep excitation signals online and the SA sensors received and detected real-time signals before and after damage.The wavelet analysis and statistical characteristics about damage signals were used as a signal processing and analysis tool to extract the optimal damage information and establish a statistical damage detection algorithm.The damage index-based wavelet analysis and damage probability-based probability and statistics were proposed by PZT wavebased theory and active health monitoring technology.The results showed that the existence of cracks inside largely attenuated the amplitude of active monitoring signal after the damage of beam and the attenuation was related to the severity degree of damage.The innovative statistical algorithm of damage pattern detection based PZT-SA can effectively determine damage probability and damage degree,and provide a prediction for the critical damage location of reinforced concrete structures.The developed method can be utilized for the structural health comprehensive monitoring and damage detection on line of various large-scale concrete structures.展开更多
The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgi...The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord （SCI, n = 16） or sham operation （SHAM, n = 14）. TBMS （tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor）, assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content （BMC）, and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors＇ results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.展开更多
To estimate a compressive strength from existing concrete structures by core drilling are usually gathered with a diameter specimen of 100 mm or three times of maximum coarse aggregate size and examined by uniaxial co...To estimate a compressive strength from existing concrete structures by core drilling are usually gathered with a diameter specimen of 100 mm or three times of maximum coarse aggregate size and examined by uniaxial compressive strength （UCS）. It is relatively difficult to gather a large sized core, and a pit place will be limited by main members. To get an alternative solution with smaller specimen, point load test （PLT） has been sele,：ted which is a simple test and widely accepted in rock materials research, but relatively new in concrete. The reliability of PLT is evaluated by extracting a lot of core drilled specimen from ready mixed concrete blocks with maximum coarse aggregate size, G of 20 mm in representative of architectural structures and 40 mm in representative of civil structures on the range of concrete grade from 16 to 50. Compressive strengths were classified into general categories, conversion factors were determined, and scattering characteristics were also investigated. The relationship between point load index （Is） and compressive strength of concrete core specimen （fcc） can be written as linear approximation as fcc = k.Is- C.展开更多
文摘Objective. To evaluate the effects of alendronate on the structural properties of trabecular bone.Methods. Alendronate was administered at a daily p. o. dose of 0. 5 mg/kg over a 12-week period in hound dogs (n = 8 for both the control and treated group), and the structural indices of the lumbar vertebral (LI and L2) trabecular bone were assessed directly from 3-D images.Results. Treatment with alendronate increased bone volume fraction by 9. 5% and 7. 7% in L1 and L2 respectively. Trabecular thickness significantly increased after alendronate treatment, whereas trabecular separation remained constant. The degree of anisotropy for the alendronate - treated group was decreased compared with that of the control group. Bone surface to volume ratio declined significantly in the alendronate-reated group, whereas alendronate induced a higher bone surface density.Conclusion. Alendronate increased the structural properties of canine trabecular bone after short-term treatment at a dose of 0. 5 mg · kg-1·day-1.
文摘AIM： To investigate the response of astrocytes and neurons in rat lumbo±sacral spinal cord and medulla oblongata induced by chronic colonic inflammation, and the relationship between them. METHODS： Thirty-three male Sprague-Dawley rats were randomly divided into two groups： experimental group （n = 17）, colonic inflammation was induced by intra-luminal administration of trinitrobenzenesulfonic acid （TNBS）; control group （n = 16）, saline was administered intra-luminally. After 3, 7, 14, and 28 d of administration, the lumbo-sacral spinal cord and medulla oblongata were removed and processed for anti-glial fibrillary acidic protein （GFAP）, Fos and GFAP/Fos immunohistochemistry. RESULTS： Activated astrocytes positive for GFAP were mainly distributed in the superficial laminae （laminae Ⅰ-Ⅱ） of dorsal horn, intermediolateral nucleus （laminae Ⅴ）, posterior commissural nucleus （laminae Ⅹ） and anterolateral nucleus （laminae Ⅸ）. Fos-IR （Fos-immunoreactive） neurons were mainly distributed in the deeper laminae of the spinal cord （laminae Ⅲ-Ⅳ, Ⅴ-Ⅵ）. In the medulla oblongata, both GFAP-IR astrocytes and Fos-IR neurons were mainly distributed in the medullary visceral zone （MVZ）. The density of GFAP in the spinal cord of experimental rats was significantly higher after 3, 7, and 14 d of TNBS administration compared with the controls （50.44±16.8, 29.24±6.5, 24.14±5.6, P〈0.05）. The density of GFAP in MVZ was significantly higher after 3 d of TNBS administration （34.34±2.5, P〈0.05）. After 28 d of TNBS administration, the density of GFAP in the spinal cord and MVZ decreased and became comparable to that of the controls （18.04±4.9, 14.64±6.4, P〉0.05）. CONCLUSION： Astrocytes in spinal cord and medulla oblongata can be activated by colonic inflammation. The activated astrocytes are closely related to Fos-IR neurons. With the recovery of colonic inflammation, the activity ofastrocytes in the spinal cord and medulla oblongata is reduced.
基金Supported by Science and Technology Project of Ministry of Housing and Urban-Rural Development(No.2011k211)"11th Five-Year" Science and Technology Research Project of Education Department,Jilin Province(No.200925)Liaoning Structure Engineering Key Laboratory 2009 Open Fund(JG2009 2007-08)
文摘The functional piezoelectric ceramic smart aggregate(SA) sensors and actuators,based on piezoelectric ceramic materials such as lead zirconium titanate(PZT),were embedded into the reinforced concrete beams with three-point bending under static loading for purposes of damage detection.The SA actuators generated the desired sine sweep excitation signals online and the SA sensors received and detected real-time signals before and after damage.The wavelet analysis and statistical characteristics about damage signals were used as a signal processing and analysis tool to extract the optimal damage information and establish a statistical damage detection algorithm.The damage index-based wavelet analysis and damage probability-based probability and statistics were proposed by PZT wavebased theory and active health monitoring technology.The results showed that the existence of cracks inside largely attenuated the amplitude of active monitoring signal after the damage of beam and the attenuation was related to the severity degree of damage.The innovative statistical algorithm of damage pattern detection based PZT-SA can effectively determine damage probability and damage degree,and provide a prediction for the critical damage location of reinforced concrete structures.The developed method can be utilized for the structural health comprehensive monitoring and damage detection on line of various large-scale concrete structures.
文摘The study aimed to examine changes in trabecular bone microstructure （TBMS） during the period of 5 weeks after the injury in a rat model of spinal cord injury （SCI）. Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord （SCI, n = 16） or sham operation （SHAM, n = 14）. TBMS （tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor）, assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content （BMC）, and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors＇ results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.
文摘To estimate a compressive strength from existing concrete structures by core drilling are usually gathered with a diameter specimen of 100 mm or three times of maximum coarse aggregate size and examined by uniaxial compressive strength （UCS）. It is relatively difficult to gather a large sized core, and a pit place will be limited by main members. To get an alternative solution with smaller specimen, point load test （PLT） has been sele,：ted which is a simple test and widely accepted in rock materials research, but relatively new in concrete. The reliability of PLT is evaluated by extracting a lot of core drilled specimen from ready mixed concrete blocks with maximum coarse aggregate size, G of 20 mm in representative of architectural structures and 40 mm in representative of civil structures on the range of concrete grade from 16 to 50. Compressive strengths were classified into general categories, conversion factors were determined, and scattering characteristics were also investigated. The relationship between point load index （Is） and compressive strength of concrete core specimen （fcc） can be written as linear approximation as fcc = k.Is- C.
