Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To ...Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae,and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography（m CT）, micro-finite element, histology, and serum biochemical analyses.At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.展开更多
The mask-free SF6/O2 plasma etching technique is used to produce surface texturization of mc-silicon solar cells for efficient light trapping in this work. The SEM images and mc-silicon etching rate show the influence...The mask-free SF6/O2 plasma etching technique is used to produce surface texturization of mc-silicon solar cells for efficient light trapping in this work. The SEM images and mc-silicon etching rate show the influence of plasma power, SF6/O2 flow ratios and etching time on textured surface. With the acidic-texturing samples as a reference, the reflection and IQE spectra are obtained under different experimental conditions. The IQE spectrum measurement shows an evident increase in the visible and infrared responses. By using the optimized plasma power, SF6/O2 flow ratios and etching time, the optimal etticiency of 15.7% on 50 × 50mm2 reactive ion etching textured mc-silicon silicon solar ceils is achieved, mostly due to the improvement in the short-circuit current density. The corresponding open-circuit voltage, short-circuit current density and fill factor are 611 m V, 33.6 mA/cm2, 76.5%, respectively. It is believed that such a low-cost and high-performance texturization process is promising for large-scale industrial silicon solar cell manufacturing.展开更多
Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the sp...Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the spinal cord,which could be result in life threatening展开更多
This article intends to shed some light on effective use of three reading strategies: skimming,scanning and studying for non-English-speaking middle school students.The article also presents some advice for the teache...This article intends to shed some light on effective use of three reading strategies: skimming,scanning and studying for non-English-speaking middle school students.The article also presents some advice for the teacher's consideration when designing and preparing reading materials.展开更多
基金supported by the National Institutes of Health(R01DK095803 to LQ, 1K08HD049598 to YZ)Penn Center for Musculoskeletal Disorders P30AR050950(NIAMS/NIH)+1 种基金ASBMR Junior Faculty Osteoporosis Basic Research Award(to LQ)NIH/NIAMS R03-AR065145(to XSL)
文摘Spinal cord injury（SCI）-induced bone loss represents the most severe osteoporosis with no effective treatment.Past animal studies have focused primarily on long bones at the acute stage using adolescent rodents. To mimic chronic SCI in human patients, we performed a comprehensive analysis of long-term structural and mechanical changes in axial and appendicular bones in adult rats after SCI. In this experiment, 4-month-old Fischer 344 male rats received a clinically relevant T13 contusion injury. Sixteen weeks later, sublesional femurs, tibiae,and L4 vertebrae, supralesional humeri, and blood were collected from these rats and additional non-surgery rats for micro-computed tomography（m CT）, micro-finite element, histology, and serum biochemical analyses.At trabecular sites, extreme losses of bone structure and mechanical competence were detected in the metaphysis of sublesional long bones after SCI, while the subchondral part of the same bones showed much milder damage. Marked reductions in bone mass and strength were also observed in sublesional L4 vertebrae but not in supralesional humeri. At cortical sites, SCI induced structural and strength damage in both sub- and supralesional long bones. These changes were accompanied by diminished osteoblast number and activity and increased osteoclast number and activity. Taken together, our study revealed site-specific effects of SCI on bone and demonstrated sustained inhibition of bone formation and elevation of bone resorption at the chronic stage of SCI.
基金Supported by the National Natural Science Foundation of China under Grant No 61306076the Youth Innovation Promotion of Chinese Academy under Grant No Y510411C31
文摘The mask-free SF6/O2 plasma etching technique is used to produce surface texturization of mc-silicon solar cells for efficient light trapping in this work. The SEM images and mc-silicon etching rate show the influence of plasma power, SF6/O2 flow ratios and etching time on textured surface. With the acidic-texturing samples as a reference, the reflection and IQE spectra are obtained under different experimental conditions. The IQE spectrum measurement shows an evident increase in the visible and infrared responses. By using the optimized plasma power, SF6/O2 flow ratios and etching time, the optimal etticiency of 15.7% on 50 × 50mm2 reactive ion etching textured mc-silicon silicon solar ceils is achieved, mostly due to the improvement in the short-circuit current density. The corresponding open-circuit voltage, short-circuit current density and fill factor are 611 m V, 33.6 mA/cm2, 76.5%, respectively. It is believed that such a low-cost and high-performance texturization process is promising for large-scale industrial silicon solar cell manufacturing.
文摘Introduction-The cervical spine is subjected to injury frequently,especially among pilots who are usually on the condition of high acceleration.Injuries of the cervical spine will be potential risk of damage to the spinal cord,which could be result in life threatening
文摘This article intends to shed some light on effective use of three reading strategies: skimming,scanning and studying for non-English-speaking middle school students.The article also presents some advice for the teacher's consideration when designing and preparing reading materials.
