Objective: To examine the effects of ursolic acid(UA) on mitigating retinoic acid(RA)-induced osteoporosis in rats. Methods: Fifty female Sprague-Dawley rats were randomly divided into the control group(n=10) and the ...Objective: To examine the effects of ursolic acid(UA) on mitigating retinoic acid(RA)-induced osteoporosis in rats. Methods: Fifty female Sprague-Dawley rats were randomly divided into the control group(n=10) and the osteoporosis group(n=40). The 40 osteoporosis rats were induced by 75 mg/(kg·d) RA once daily for 2 weeks, and then were randomly assigned to vehicle control(model), low-, middle-, and high-dose UA [(UA-L, UA-M, UA-H; 30, 60, 120 mg/(kg·d), respectively] groups(10 rats each). UA were administered once daily to the rats from the 3 rd weeks for up to 4 weeks by gavage. Bone turnover markers [serum alkaline phosphatase(ALP), osteocalcin(OCN), urine deoxypyridinoline(DPD)] and other parameters, including serum calcium(S-Ca), serum phosphorus(S-P), urine calcium(U-Ca), urine phosphorus(U-P), and bone mineral density(BMD) of the femur, 4 th lumbar vertebra and tibia, bone biomechanical properties and trabecular microarchitecture, were measured. Results: The osteoporosis in rats was successfully induced by RA. Compared with the model group, UA-M and UA-H significantly reversed the RA-induced changes in S-P, U-Ca, U-P, ALP, OCN and urine DPD ratio and markedly enhanced the BMD of right femur, 4 th lumbar vertebra and tibia(P<0.05 or P<0.01). Further, biomechanical test and microcomputed tomography evaluation also showed that UA-H drastically improved biomechanical properties and trabecular microarchitecture(P<0.05 or P<0.01). Conclusion: UA could promote bone formation, increase osteoblastic activity and reduce osteoclastic activity in rats, indicating that UA might be a potential therapeutic of RA-induced acute osteoporosis.展开更多
This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion s...This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.展开更多
Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SE...Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.展开更多
The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at appar...The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.展开更多
借助Micro—CT评价单纯牛骨形态发生蛋白（bovine bone morphogenetic protein，bBMP）异位诱导成骨的长期三维影像学及骨质变化。（20±2）g昆明小鼠21只，麻醉后于双侧股部肌肉中植入bBMP各2mg，分别于1、2、4、6、8、10、12周各...借助Micro—CT评价单纯牛骨形态发生蛋白（bovine bone morphogenetic protein，bBMP）异位诱导成骨的长期三维影像学及骨质变化。（20±2）g昆明小鼠21只，麻醉后于双侧股部肌肉中植入bBMP各2mg，分别于1、2、4、6、8、10、12周各处死3只，切取诱导分化组织，5％戊二醛固定，行Micro—CT扫描和三维重建，运用ABA专用骨骼分析软件测定组织矿含量（tissue mineral content，TMC），组织骨密度（tissue mineral density，TUB），骨体积分数（bone volume fraction，BVF），结构模型指数（structure model index，SMI），骨小梁厚度（trabecular thickness，Tb．Th），骨小梁数量（trabecular number，Tb．N）及皮质骨骨密度（bone mineral density，BMD）等参数，运用SPSS10．0统计软件进行统计学分析。bBMP从植入2周开始逐渐形成一椭圆形骨组织块，2～4周，异位生成骨呈疏松的新生骨，4周时组织矿含量达第一个峰值，骨小梁数量最多；随着观察时间的延长（6-12周），异位诱导生成的椭圆形骨组织内部骨小梁逐渐吸收，数量减少，12周时骨小梁数量最少；而外层骨组织逐渐塑形成为皮质骨，12周时骨矿含量值、骨小梁厚度、组织骨密度和皮质骨骨密度均达最大值。说明bBMP具有强大的异位骨诱导能力，血供不足时，骨质降解吸收；血供充足时，骨质逐渐成熟改建。展开更多
目的观察人成骨细胞刺激因子(OSF-1)对去卵巢骨质疏松大鼠的治疗效果。方法健康4月龄SD雌性大鼠12只,随机分为假手术组(SHAM组)、去势组(OVX组)、甲状旁腺激素组(PTH组)和OSF-1组,每组3只。SHAM组切除卵巢附近脂肪组织,其他各组切除双...目的观察人成骨细胞刺激因子(OSF-1)对去卵巢骨质疏松大鼠的治疗效果。方法健康4月龄SD雌性大鼠12只,随机分为假手术组(SHAM组)、去势组(OVX组)、甲状旁腺激素组(PTH组)和OSF-1组,每组3只。SHAM组切除卵巢附近脂肪组织,其他各组切除双侧卵巢。术后10周,SHAM组和OVX组皮下注射生理盐水,0.2 m L/d,PTH组皮下注射PTH,20μg/(kg·d),OSF-1组皮下注射OSF-1,80μg/(kg·d)。术后21周,处死大鼠,分离子宫并称重,分离股骨,显微CT扫描干骺端。结果 OVX组子宫重和骨量较SHAM组显著降低(P<0.01),骨小梁微结构明显破坏。与OVX组相比,PTH组和OSF-1组的骨密度、骨体积分数、骨小梁数量显著增加(P<0.01),骨小梁分离度和模式因子显著下降(P<0.01,P<0.05),骨小梁微结构更紧密。PTH组较OSF-1组骨密度、骨体积分数、骨小梁数量显著增加(P<0.01),骨小梁模式因子显著下降(P<0.01)。结论皮下注射OSF-1[80μg/(kg·d)]可有效增加去卵巢大鼠的骨量,改善骨小梁微结构。展开更多
基金Supported by Qinling-Bashan Mountains Bioresources Comprehensive Development Collaborative Innovation Center(No.QBXT-Z(Z)-15-4)
文摘Objective: To examine the effects of ursolic acid(UA) on mitigating retinoic acid(RA)-induced osteoporosis in rats. Methods: Fifty female Sprague-Dawley rats were randomly divided into the control group(n=10) and the osteoporosis group(n=40). The 40 osteoporosis rats were induced by 75 mg/(kg·d) RA once daily for 2 weeks, and then were randomly assigned to vehicle control(model), low-, middle-, and high-dose UA [(UA-L, UA-M, UA-H; 30, 60, 120 mg/(kg·d), respectively] groups(10 rats each). UA were administered once daily to the rats from the 3 rd weeks for up to 4 weeks by gavage. Bone turnover markers [serum alkaline phosphatase(ALP), osteocalcin(OCN), urine deoxypyridinoline(DPD)] and other parameters, including serum calcium(S-Ca), serum phosphorus(S-P), urine calcium(U-Ca), urine phosphorus(U-P), and bone mineral density(BMD) of the femur, 4 th lumbar vertebra and tibia, bone biomechanical properties and trabecular microarchitecture, were measured. Results: The osteoporosis in rats was successfully induced by RA. Compared with the model group, UA-M and UA-H significantly reversed the RA-induced changes in S-P, U-Ca, U-P, ALP, OCN and urine DPD ratio and markedly enhanced the BMD of right femur, 4 th lumbar vertebra and tibia(P<0.05 or P<0.01). Further, biomechanical test and microcomputed tomography evaluation also showed that UA-H drastically improved biomechanical properties and trabecular microarchitecture(P<0.05 or P<0.01). Conclusion: UA could promote bone formation, increase osteoblastic activity and reduce osteoclastic activity in rats, indicating that UA might be a potential therapeutic of RA-induced acute osteoporosis.
基金the financial support from the National Natural Science Foundation of China(No.81430087)the National Science and Technology Major Project(2013ZX09402103)
文摘This study investigated the formulation mechanism of microspheres via internal surfactant distribution. Eudragit L100 based microspheres loaded with bovine serum albumin were prepared by solid in oil in oil emulsion solvent evaporation method using acetone and liquid paraffin system containing sucrose stearate as a surfactant. The fabricated microspheres were evaluated for encapsulation efficiency, particle size, production yield, and in vitro release characteristics. The internal structures of microspheres were characterized using synchrotron radiation X-ray microcomputed tomography(SR-μCT). The enhanced contrast made the sucrose stearate distinguished from Eudragit to have its three dimensional(3D) distribution. Results indicated that the content and concentration determined the state of sucrose stearate and had significant influences on the release kinetics of protein. The dispersity of sucrose stearate was the primary factor that controlled the structure of the microspheres and further affected the encapsulation efficiency, effective drug loading, as well as in vitro release behavior. In conclusion, the 3D internal distribution of surfactant in microspheres and its effects on protein release behaviors have been revealed for the first time. The highly resolved 3D architecture provides new evidence for the deep understanding of the microsphere formation mechanism.
基金Project(2017XKQY012)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Thermal shocking effect occurs when the coalbed methane(CBM)reservoirs meet liquid nitrogen(LN2)of extremely low temperature.In this study,3D via X-ray microcomputer tomography(μCT)and scanning electron microscope(SEM)are employed to visualize and quantify morphological evolution characteristics of fractures in coal after LN2 thermal shocking treatments.LN2 thermal shocking leads to a denser fracture network than its original state with coal porosity growth rate increasing up to 183.3%.The surface porosity of theμCT scanned layers inside the coal specimen is influenced by LN2 thermal shocking which rises from 18.76%to 215.11%,illustrating the deformation heterogeneity of coal after LN2 thermal shocking.The cracking effect of LN2 thermal shocking on the surface of low porosity is generally more effective than that of high surface porosity,indicating the applicability of LN2 thermal shocking on low-permeability CBM reservoir stimulation.The characteristics of SEM scanned coal matrix in the coal powder and the coal block after the LN2 thermal shocking presented a large amount of deep and shallow progressive scratch layers,fracture variation diversity(i.e.extension,propagation,connectivity,irregularity)on the surface of the coal block and these were the main reasons leading to the decrease of the uniaxial compressive strength of the coal specimen.
基金the National High Technology Research and Development Program (863) of China(No. 2006AA02A137the Postgraduate Creativity Foundation of Shanghai Jiaotong University (No. BXJ0730)
文摘The mechanical properties of the pelvic trabecular bone have been studied at the continuum level. However, nothing is known about the tissue-level damage in the trabecular bone of the healthy human acetabulum at apparent small strains characteristic of habitual. By a DAWING 4000 A supercomputer, nonlinear micro-finite element (μFE) analysis was performed to quantify tissue-level damage accumulation in trabecular bone at small strains. The data indicate that damage in trabecular bone commence at 0.2% apparent strain. The findings imply that tissue yielding can initiate at very low strains in the trabecular bone of the healthy acetabulum and that this local failure has negative consequences on the apparent mechanical properties of trabecular bone.
文摘借助Micro—CT评价单纯牛骨形态发生蛋白（bovine bone morphogenetic protein，bBMP）异位诱导成骨的长期三维影像学及骨质变化。（20±2）g昆明小鼠21只，麻醉后于双侧股部肌肉中植入bBMP各2mg，分别于1、2、4、6、8、10、12周各处死3只，切取诱导分化组织，5％戊二醛固定，行Micro—CT扫描和三维重建，运用ABA专用骨骼分析软件测定组织矿含量（tissue mineral content，TMC），组织骨密度（tissue mineral density，TUB），骨体积分数（bone volume fraction，BVF），结构模型指数（structure model index，SMI），骨小梁厚度（trabecular thickness，Tb．Th），骨小梁数量（trabecular number，Tb．N）及皮质骨骨密度（bone mineral density，BMD）等参数，运用SPSS10．0统计软件进行统计学分析。bBMP从植入2周开始逐渐形成一椭圆形骨组织块，2～4周，异位生成骨呈疏松的新生骨，4周时组织矿含量达第一个峰值，骨小梁数量最多；随着观察时间的延长（6-12周），异位诱导生成的椭圆形骨组织内部骨小梁逐渐吸收，数量减少，12周时骨小梁数量最少；而外层骨组织逐渐塑形成为皮质骨，12周时骨矿含量值、骨小梁厚度、组织骨密度和皮质骨骨密度均达最大值。说明bBMP具有强大的异位骨诱导能力，血供不足时，骨质降解吸收；血供充足时，骨质逐渐成熟改建。
文摘目的观察人成骨细胞刺激因子(OSF-1)对去卵巢骨质疏松大鼠的治疗效果。方法健康4月龄SD雌性大鼠12只,随机分为假手术组(SHAM组)、去势组(OVX组)、甲状旁腺激素组(PTH组)和OSF-1组,每组3只。SHAM组切除卵巢附近脂肪组织,其他各组切除双侧卵巢。术后10周,SHAM组和OVX组皮下注射生理盐水,0.2 m L/d,PTH组皮下注射PTH,20μg/(kg·d),OSF-1组皮下注射OSF-1,80μg/(kg·d)。术后21周,处死大鼠,分离子宫并称重,分离股骨,显微CT扫描干骺端。结果 OVX组子宫重和骨量较SHAM组显著降低(P<0.01),骨小梁微结构明显破坏。与OVX组相比,PTH组和OSF-1组的骨密度、骨体积分数、骨小梁数量显著增加(P<0.01),骨小梁分离度和模式因子显著下降(P<0.01,P<0.05),骨小梁微结构更紧密。PTH组较OSF-1组骨密度、骨体积分数、骨小梁数量显著增加(P<0.01),骨小梁模式因子显著下降(P<0.01)。结论皮下注射OSF-1[80μg/(kg·d)]可有效增加去卵巢大鼠的骨量,改善骨小梁微结构。
