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A total of 6 formalin-fixed cadavers were included in the cadaver feasibility study.The aim was to ascertain the anatomical feasibility of extradural contralateral C7 ventral root transfer technique by cervical posterior.Upper limb spastic hemiplegia is a common sequela after stroke. In our previous study, the authors established a method by transferring contralateral C7 dorsal and ventral roots to the corresponding C7 dorsal and ventral roots on the affected side in the cervical posterior.In the present study, six formalin-fixed cadavers were dissected to confirm the anatomical feasibility. Experimental anastomosis in cadavers was conducted. The pertinent lengths of the extradural nerve roots were measured. The tissue structures surrounding regions between the extradural CC7 nerve roots and the vertebral artery were observed. The cervical magnetic resonance imaging scans of 60 adults were used to measure the distance between the donor and recipient nerves.Experimental anastomosis showed that the distance between the donor and recipient nerves was approximately 1 cm; the short segment of the sural nerve needed bridging. The distance between both exit sites of the exit of the extradural dura mater was 33.57±1.55 mm. The length of the extradural CC7 ventral root was 22.00±0.98 mm. The ventral distance (vd) and the dorsal distance (dd) in males were 23.98±1.72 mm and 30.85±2.22 mm ( P0.05), while those in females were 23.28±1.51 mm and 30.03±2.16 mm, respectively. C7 vertebral transverse process, ligaments, and other soft tissues were observed between the vertebral artery and the extradural C7 nerve root.Under the premise of less trauma, our study shows that the extradural contralateral C7 ventral root transfer technique, in theory, yields better surgical results, including better recovery of motor function and complete preservation of sensory function.5.

Robot-assisted orthopedic surgery has great application prospects, and the accuracy of the robot is the key to its overall performance. The aim of this study was to develop a new orthopedic surgical robot to assist in spinal surgeries and to compare its feasibility and accuracy with the existing orthopedic robot. A new type of high-precision orthopedic surgical robot (Tuoshou) was developed. A multicenter, randomized controlled trial was carried out to compare the Tuoshou with the TiRobot (TINAVI Medical Technologies Co., Ltd., Beijing) to evaluate the accuracy and safety of their navigation and positioning. A total of 112 patients were randomized, and 108 patients completed the study. The position deviation of the Kirschner wire placement in the Tuoshou group was smaller than that in the TiRobot group (p = 0.014). The Tuoshou group was better than the TiRobot group in terms of the pedicle screw insertion accuracy (p = 0.016) and entry point deviation (p < 0.001). No differences were observed in endpoint deviation (p = 0.170), axial deviation (p = 0.170), sagittal deviation (p = 0.324), and spatial deviation (p = 0.299). There was no difference in security indicators. The new orthopedic surgical robot was highly accurate and optimized for clinical practice, making it suitable for clinical application.

Neural stem cell-derived small extracellular vesicles (NSC-sEVs) play an important role in the repair of tissue damage. Our previous in vitro and in vivo studies found that preconditioning with NSC-sEVs promoted the recovery of functional behaviors following spinal cord injury by activating autophagy. However, the underlying mechanisms for such observations remain unclear. In this study, we further explored the mechanisms by which NSC-sEVs repair spinal cord injury via autophagy. We found that NSC-sEVs contain 14-3-3t protein, of which the overexpression or knockdown enhanced and decreased autophagy, respectively. In addition, 14-3-3t overexpression enhanced the anti-apoptotic and anti-inflammatory effects of NSC-sEVs, further promoting functional behavior recovery following spinal cord injury. The overexpression of 14-3-3t was used to further validate the in vivo results through a series of in vitro experiments. Conversely, knockdown of 14-3-3t attenuated the anti-apoptotic and anti-inflammatory effects of NSC-sEVs. Further studies also confirmed that NSC-sEVs increased Beclin-1 expression, with which 14-3-3t interacted and promoted its localization to autophagosome precursors. In this study, we found that NSC-sEVs deliver 14-3-3t, which interacts with Beclin-1 to activate autophagy. Our results indicate that 14-3-3t acts via a newly-discovered mechanism for the activation of autophagy by NSC-sEVs.

BackgroundPercutaneous kyphoplasty is the main method in the treatment of thoracolumbar osteoporotic compression fractures. However, much radiation exposure during the operation harms the health of surgeons and patients. In addition, the accuracy of this surgery still needs to be improved. This study aimed to assess the radiation exposure and clinical efficacy of Tirobot-assisted vertebroplasty in treating thoracolumbar osteoporotic compression fracture.MethodsIncluded in this retrospective cohort study were 60 patients (60–90 years) who had undergone unilateral vertebroplasty for thoracolumbar osteoporotic compression fracture at our hospital between June 2019 and June 2020. All showed no systemic diseases and were assigned to Tirobot group (treated with Tirobot-assisted approach) and control group (treated with traditional approach). Fluoroscopic frequency, operative duration, length of stay (LOS), post-operative complications (cement leakage, infection, and thrombosis), and pre-operative and pre-discharge indexes (VAS score, JOA score, and Cobb’s angle) were compared.ResultsThe fluoroscopic frequency (P< 0.001) and post-operative complications (P= 0.035) in Tirobot group were significantly lower than those in control group. The operative duration and LOS in the Tirobot group were shorter than those in the control group, but the differences were not statistically significant (P= 0.183). Pre-discharge VAS score and Cobb’s angle decreased, and JOA increased after surgeries in both groups. These three indexes showed a significant difference after surgery in each group (P< 0.001), but not between groups (PVAS= 0.175,PCobb’s= 0.585,PJOA= 0.448).ConclusionThe Tirobot-assisted vertebroplasty can reduce surgery-related trauma, post-operative complications, and patients’ and operators’ exposure to radiation. As a safe and effective strategy, this surgery can realize the quick recovery from thoracolumbar osteoporotic compression fracture.

The finite element software ABAQUS is used to calculate and analyze the mechanical performance of cold-formed thin-walled curved channel steel members under horizontal reciprocating load. Double nonlinear finite element model needs to be considered, the influence of geometric imperfection and residual stress. The accuracy of the results was verified by comparing with the relevant test results. On the basis of controlling the main parameters such as width-thickness ratio, axial compression ratio, slenderness ratio and buckling mode, the numerical simulation results of 9 hysteretic specimens were selected to research the influence of the above factors on the hysteretic performance of the flexural members. The analysis results show that the width to thickness ratio, axial compression ratio and slenderness ratio have great influence on the hysteretic performance of the flexural members. The larger the three main parameters are, the worse the bearing capacity, ductility and energy consumption of the members will be. Therefore, the design should avoid as far as possible to choose a larger width-thickness ratio and slenderness ratio section components.

Purpose Clinical studies have shown that endplate Modic change in the cervical spine and intramedullary high signal intensity often occurs simultaneously. We aimed to investigate whether there is a correlation between Modic change and intramedullary high signal intensity, and to explore the possible risk factors. Materials and methods In total, 133 patients with cervical spondylotic myelopathy treated at the First Affiliated Hospital of Nanjing Medical University between May 2009 and March 2013 were enrolled in the study. Preoperative cervical magnetic resonance imaging and radiographs in hyperextension and hyperflexion were analyzed. With regard to magnetic resonance imaging, all patients were classified into groups according to Modic change types and intramedullary high signal intensity; the ratio of spinal cord compression reflected the degree of spinal stenosis. For plain radiographs, total range of motion (ROM) and segmental ROM of the cervical vertebrae were measured. Results Modic change of the cervical vertebral endplate and intramedullary high signal intensity demonstrated a significantly positive correlation. In patients with Modic change and intramedullary high signal intensity, the segmental angle of motion of the cervical vertebrae in hyperextension, cervical segmental ROM, and ratio of spinal cord compression were significantly higher than in patients without Modic change and intramedullary high signal intensity. Conclusions The occurrence of Modic change and intramedullary high signal intensity are related to cervical instability and spinal canal stenosis. Severe disc protrusion may cause an increase of ROM in cervical hyperextension. Such patients are more prone to Modic change of the cervical vertebral endplate and intramedullary high signal intensity.

The aim of the present study was to investigate risk factors for the development of an acute-phase response (APR) associated with the initial zoledronic acid (ZA) infusion in patients undergoing surgery, and to assess whether its onset may be reduced by post-dose administration of low-dose methylprednisolone (MP) or acetaminophen. A retrospective study of patients with osteoporosis who attended the departments of orthopedics and endocrinology of a single hospital and received 5 mg ZA was conducted; the patients included surgical and non-surgical cases. A total of 450 ZA-naïve patients who were treated with acetaminophen following ZA infusion were stratified based on whether they suffered APR (APR+) or not (APR−). In addition, 155 of the aforementioned acetaminophen-treated patients (acetaminophen group) were compared with another 32 patients from the orthopedic department who were treated with MP immediately following ZA infusion (MP group). Inflammatory marker levels were significantly higher in APR+ patients than in APR− patients, and the odds ratios of experiencing APR following minimally invasive or open surgery were found to be 3.54 (P

The goal of this paper was to study preoperative concentrations of vitamin D in patients undergoing spinal surgery and analyze relevant risk factors associated with vitamin D deficiency. Vitamin D plays an important role in maintaining normal functions of skeletal muscles, and vitamin D insufficiency or deficiency may affect outcomes of spinal surgery patients. A retrospective analysis was conducted on 503 patients undergoing spinal surgery in the First Affiliated Hospital with Nanjing Medical University from September 2012 to October 2013. Preoperative concentrations of serum 25-hydroxyvitamin D [25(OH)D] were measured. Normal vitamin D was defined as a serum 25(OH)D level ≥ 32 ng/mL, vitamin D insufficiency as ≥20 and

Clear cell sarcoma is a rare malignant soft tissue neoplasm with a predilection for arising deep soft tissues adjacent to tendons and aponeuroses and fascial structures. This report presents a 32-year-old woman with low back pain and swelling, night sweat and lateral numbness in her right thigh for three months. MRI revealed a 4.0 x 5.8 cm vertebral lesion on the right lumbar region, without characteristics of a melanin rich tumor. Immunohistochemistry and fluorescence in situ hybridization confirmed diagnosis of clear cell sarcoma. The patient underwent a chemotherapy protocol. At four months post-surgery, CT revealed a soft tissue lesion in the right L3, suspected to be either a cancer relapse or harmless post-surgery lesion. Radiotherapy was performed in precaution of a relapse. At eleven months post-surgery, tumor relapse and multiple bone metastasis were observed. Combination of imaging methods improves diagnostics and subsequently differentiate clear cell sarcoma from other pathologies.

Winter wheat production in the North China Plain (NCP) relies mainly on irrigation. To assess the effect irrigation management practices on crop production, the HYDRUS-1D model was modified by incorporating the crop growth module adopted from the EPIC model. The modified HYDRUS-1D model was calibrated and validated by using data collected from 2006/2007 and 2007/2008 winter wheat growing seasons in Beijing area. The predicted values for soil water content, soil nitrate concentration, crop growth, yield, and evapotranspiration showed good agreements with the measured values. The calibrated model was then used to evaluate the yield and water use efficiency (WUE) under different hydrologic years. The WUE for different irrigation depth was considered as the criterion for investigating the appropriate irrigation management practices. Results showed that the appropriate irrigation depth per application could be determined as 62.5% of the difference between 20 cmpan evaporation and precipitation for hydrologic years with 75%, 50% and 25% probability of rainfall occurrence, respectively, under the recommended nitrogen application rate in Beijing area. And the corresponding total irrigation amount was 244.7, 213.8 and 192.5 mm. The results of this study provide scientific implications for water management of winter wheat under sprinkler irrigation in the NCP and those areas with similar climatic and cropping practice conditions.

This study aimed to introduce a novel mini-open pedicle screw fixation technique via Wiltse approach, and compared it with the traditional posterior open method. A total of 72 cases of single-segment thoracolumbar fractures without neurologic injury underwent pedicle screw fixation via two different approaches. Among them, 37 patients were treated using posterior open surgery, and 35 patients received mini-open operation via Wiltse approach. Crew placement accuracy rate, operative time, blood loss, postoperative drainage, postoperative hospitalization time, radiation exposure time, postoperative improvement in R value, Cobb's angle and visual analog scale (VAS) scores of the two methods were compared. There were no significant differences in the accuracy rate of pedicle screw placement, radiation exposure and postoperative R value and Cobb's angle improvement between the two groups. However, the mini-open method had obvious advantages over the conventional open method in operative time, blood loss, postoperative drainage, postoperative hospitalization time, and postoperative improvement in VAS. The mini-open pedicle screw technique could be applied in treatment of single-segment thoracolumbar fracture without neurologic injury and had advantages of less tissue trauma, short operative and rehabilitative time on the premise of guaranteed accuracy rate and no increased radiation exposure.

To investigate the effect of zoledronic acid (ZA) on lumbar spinal fusion in patients with osteoporosis. This retrospective study includes 94 osteoporotic patients suffering from lumbar degenerative diseases or lumbar fracture who underwent lumbar spinal fusion in our institution from January 2013 to August 2014. They were divided into ZA group and control group according to whether the patient received ZA infusion or not. The patients in ZA group were given 5 mg intravenous ZA at the 3rd–5th days after operation. All patients took daily oral supplement of 600 mg calcium carbonate and 800 IU vitamin D during the follow-up after operation. The Visual Analogue Scale (VAS), Oswestry Disability Index (ODI), and Short Form 36 (SF-36) scores were recorded preoperatively and post-operatively to evaluate the clinic outcomes; the spinal fusion was assessed by X-ray or CT Scan. 64 patients finished the final follow-up, including 30 patients in ZA group and 34 patients in control group. No significant difference was observed in gender, age, and preoperative BMI VAS, ODI, and SF-36 scores between the two groups (P > 0.05). The post-operative VAS and ODI scores decreased rapidly at 3 and 6 months, but rose back slightly at 12 and 24 months in both groups. On the contrary, post-operative SF-36 scores increased rapidly at 3 and 6 months, while fell back slightly at 12 and 24 months, with a statistically significant difference between the two groups at 12 months, but not at 3 and 6 month post-operation. The spinal fusion rate in ZA group was 90% at 6 months, 92% at 12 months, while it was 75% at 6 months, 92.86% at 12 months in control group, significantly different between the two groups at 12 months, but not at 6 months. In the whole follow-up period, adjacent vertebral compressing fracture occurred in five patients in control group, none in ZA group. No pedicle screw loosening was observed in ZA group, with six in control group. Zoledronic acid accelerates spinal fusion, shortens the time of fusion without changing fusion rate, and also decreases the risk of adjacent vertebral compressing fracture and the rate of pedicle screw loosening, resulting in the improvement of clinical outcomes and quality of life.

Background/Aims: Endogenous parathyroid hormone (PTH) plays an important role in fracture healing. This study investigated whether endogenous PTH regulates fracture healing by bone morphogenetic protein (BMP) and/or the transforming growth factor-β (TGF-β) signaling pathway. Methods: Eight-week-old wild-type (WT) and PTH-knockout (PTH KO) male mice were selected, and models of open right-femoral fracture were constructed. Fracture healing and callus characteristics of mice in the two groups were compared by X-ray, micro-computed tomography, histological, and immunohistochemical examinations. Bone marrow mesenchymal stem cells (BMMSCs) of 8-week-old WT and PTHKO male mice were obtained and induced into osteoblasts and chondrocytes. Results: We found that expression levels of Runt-related transcription factor (RUNX2), bone morphogenetic protein-receptor-type Ⅱ (BMPR2), phosphorylated Smad 1/5/8, and phosphorylated cyclic adenosine monophosphate-responsive element binding protein (CREB) in the callus of PTHKO mice were significantly decreased, whereas no significant difference in expression of SOX9, TGF-βR2,or pSMAD2/3 was observed between PTHKO and WT mice. Additionally, the activity of osteoblast alkaline phosphatase was low at 7 days post-induction, and was upregulated by addition of PTH or dibutyryl cyclic adenosine monophosphate (dbcAMP) to the cell culture. Furthermore, H89 (protein kinase A inhibitor)eliminated the simulating effects of PTH and dbcAMP, and a low concentration of cyclic adenosine monophosphate (cAMP) was observed in PTHKO mouse BMMSCs. Conclusion: These results suggested that endogenous PTH enhanced BMPR2 expression by a cAMP/PKA/CREB pathway in osteoblasts, and increased RUNX2 expression through transduction of the BMP/pSMAD1/5/8 signaling pathway.

The North China Plain (NCP) is one of the main productive regions for winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) in China. However, water-saving irrigation technologies (WSITs), such as sprinkler irrigation technology and improved surface irrigation technology, and water management practices, such as irrigation scheduling have been adopted to improve field-level water use efficiency especially in winter wheat growing season, due to the water scarcity and continuous increase of water in industry and domestic life in the NCP. As one of the WSITs, sprinkler irrigation has been increasingly used in the NCP during the past 20 years. In this paper, a three-year field experiment was conducted to investigate the responses of volumetric soil water content (SWC), winter wheat yield, evapotranspiration (ET), water use efficiency (WUE) and irrigation water use efficiency (IWUE) to sprinkler irrigation regimes based on the evaporation from an uncovered, 20-cm diameter pan located 0–5 cm above the crop canopy in order to develop an appropriate sprinkler irrigation scheduling for winter wheat in the NCP. Results indicated that the temporal variations in SWC for irrigation treatments in the 0–60-cm soil layer were considerably larger than what occurred at deeper depths, whereas temporal variations in SWC for non-irrigation treatments were large throughout the 0–120-cm soil layer. Crop leaf area index, dry biomass, 1000-grains weight and yield were negatively affected by water stress for those treatments with irrigation depth less than 0.50E, where E is the net evaporation (which includes rainfall) from the 20-cm diameter pan. While irrigation with a depth over 1.0E also had negative effect on 1000-grains weight and yield. The seasonal ET of winter wheat was in a range of 206–499 mm during the three years experiments. Relatively high yield, WUE and IWUE were found for the irrigation depth of 0.63E. Therefore, for winter wheat in the NCP the recommended amount of irrigation to apply for each event is the total 0.63E that occurred after the previous irrigation provided total E is in a range of 30–40 mm.

Objective Giant cell tumours(GCT) represent one of the most common benign tumours of bone. However, despite its benign nature they are aggressive lesions that have a tendency to recur. This study aims to report experience with the treatment of GCTs, and reviews the relationship between surgical management and clinical outcome. Methods A retrospective review was performed with 70 patients (32 males and 38 females) who presented to our institution between 1991 and 2001 with GCT of bone. An evaluation of the oncological and functional results was conducted and patients were divided into three groups according to the treatment method; Group I: (46 patients) intralesional curettage and adjuvant therapy and packing with filling materials. Group II: (18 patients) en-bloc resection and arthrodesis or reconstruction. Group III: (6 patients) amputation. Results The mean follow-up period was 10 years (range, 5-15 years). The overall rate of local recurrence was 14%, 22% in Group I, and only 4% in Group II and Group III. According to the Musculoskeletal Tumour Society(MSTS) score for functional outcome, the mean overall score for Group I was 27.9 (out of 30), 15.9 for Group II. Of note, the 9 patients within Group II who received endoprosthetic reconstruction, the mean overall MSTS functional score was 25.5. Conclusion Intralesional curettage with adjuvant therapies and filling agents is often associated with a relatively high recurrence rate, however joint function is well preserved. Patients with more extensive, biologically aggressive, and/or recurrent tumours are best treated with en-bloc resection.

Background Percutaneous vertebroplasty (PVP) has been demonstrated to be effective in the treatment of osteoporotic fracture. The bilateral pedicular approach is the most frequently used method. However, unilateral PVP is becoming increasingly more attractive for surgeons because of its numerous benefits, including lower radiation exposure, less tissue injury, and less bone cement leakage. The purpose of this study was to investigate the anatomical feasibility of unilateral PVP by exploring the differences in the puncture success rate of the unilateral pedicular approach among different lumbar segments, between men and women, and between the left and right sides. Methods Punctures were simulated on magnetic resonance imaging scans of 200 patients (100 men, 100 women) at a maximum angle via a pedicular approach. The distance between the entry point and the midline of the vertebral body, the maximum puncture angle, the puncture success value, and the puncture success rate were measured and compared among different lumbar levels, between the two sexes, and between the left and right sides. Results The maximum puncture distance between the entry point and the midline gradually increased from L1 to L5, and the maximum puncture angle showed the same tendency from L1 to L5. The puncture success values for L3 and L4 were higher than those for the other lumbar levels (L1, 31.53 ± 34.45; L2, 42.15 ± 28.06; L3, 56.21 ± 18.30; L4, 56.20 ± 12.93; and L5, 48.01 ± 6.88). The puncture success rates varied from 69.5 to 98.0 % among the different lumbar levels; L3 and L4 were the two highest (L3, 95.5 %; L4, 98.0 %). There were significant differences in these measurements between men and women and between the left and right sides. Conclusions PVP with the unilateral puncture approach appears more likely to succeed at L3 to L5 than at L1 and L2. The unilateral approach might be more suitable for men than women at levels other than L5. Additionally, the left pedicular approach might be optimal for unilateral PVP procedures.

BackgroundThe beta2-adrenergic receptor (ADRB2) gene polymorphism has been implicated in susceptibility to obesity, but study results are still controversial.ObjectiveThe present meta-analysis is performed to determine whether there are any associations between the Gln27Glu (rs1042714) or the Arg16Gly (rs1042713) polymorphisms in ADRB2 and obesity susceptibility.MethodsThe PubMed (1950-2014), Embase (1974-2014), and China National Knowledge Infrastructure (CNKI, 1994-2014) databases were searched using the search terms ("Beta2-adrenergic receptor", "β2-adrenergic receptor" or "ADRB2"), "polymorphism," and "obesity". Fixed- or random-effects pooled measures were determined on the bias of heterogeneity tests across studies. Publication bias was examined by Egger's test and the modified Begg's test.ResultsEighteen published articles were selected for meta-analysis. Overall analyses showed that rs1042714 (Gln27Glu) was associated with significantly increased obesity risk in the heterozygote model (Gln/Glu vs. Gln/Gln: OR: 1.16, 95% CI: 1.04-1.30, I2 = 49%, P = 0.009) and the dominant model (Gln/Glu + Glu/Glu vs. Gln/Gln: OR: 1.2, 95% CI: 1.00-1.44, I2 = 55%, P = 0.04), whereas no significant association was found in the other models for rs1042714. Also, no significant association was found between the rs1042713 (Arg16Gly) gene polymorphism and the risk of obesity in all genetic models. In addition, neither rs1042713 (Arg16Gly) nor rs1042714 (Gln27Glu) showed any significant association with obesity susceptibility when the population were stratified based on gender.ConclusionOur meta-analysis revealed that the rs1042714 (Gln27Glu) polymorphism is associated with obesity susceptibility. However, our results do not support an association between rs1042713 (Arg16Gly) polymorphisms and obesity in the populations investigated. This conclusion warrants confirmation by more case-control and cohort studies.

STUDY DESIGN Technical note. OBJECTIVE To determine the correlation between the high-intensity lesions observed on T2-weighted magnetic resonance images (T2W MRI) and the cervical dynamic characteristics of patients with cervical spondylotic myelopathy (CSM). SUMMARY OF BACKGROUND DATA Intramedullary high signal intensity is frequently observed on T2W MRI of CSM patients and represents pathologic changes in the spinal cord. However, few studies have attempted to identify the effects on cervical dynamics associated with such changes in MRI signals. METHODS This study included 71 CSM patients who were admitted to our hospital between May, 2009 and May, 2012 (44 men, 27 women; average age, 52.5±11.7 y). They were divided into 3 groups depending on T2W MRI data: group 1, no hyperintensity; group 2, slight hyperintensity; and group 3, bright hyperintensity. The Cobb angle on cervical flexion-extension radiographs was measured as a parameter of cervical spine dynamics. RESULTS Total hyperflexion, hyperextension curvature, range of movement (ROM), and segmental hyperflexion curvature did not differ among the groups (P>0.05). Segmental hyperextension curvature and ROM were greater in groups 2 and 3 than in group 1 (P 0.05). CONCLUSIONS Increased segmental hyperextension curvature (≥10 degrees) and ROM are risk factors for high-intensity lesions on T2W MRI in CSM patients.

We sought to compare the safety and accuracy of a new free-hand pedicle screw placement technique to that of the conventional technique. One hundred fifty-three consecutive adult patients with simple fracture in the thoracic or/and lumbar spine were alternately assigned to either the new free-hand or the conventional group. In the new free-hand technique group, preoperative computerized tomography (CT) images were used to calculate the targeted medial-lateral angle of each pedicle trajectory and the pedicle screw was inserted perpendicular to the correspond-ing supraspinal ligament. In the conventional technique group, the medial-lateral and cranial-caudal angle of each pedicle trajectory was determined by intraoperatively under fluoroscopic guidance. The accuracy rate of pedicle screw placement, the time of intraoperative fluoroscopy, the operating time and the amount of blood loss during operation were respectively compared. All screws were analyzed by using intraoperative radiographs, intraoperative triggered electromyography (EMG) monitoring data, postoperative CT data and clinical outcomes. The accuracy rate of pedicle screw placement in the new free-hand technique group and the conventional technique group was 96.3% and 94.2% (P < 0.05), respectively. The intraoperative fluoroscopy time of the new technique group was less than that of the conventional technique group (5.37 seconds vs. 8.79 seconds, P < 0.05). However, there was no statistical difference in the operating time and the amount of blood loss during operation (P > 0.05). Pedicle screw placement with the free-hand technique which keeps the screw perpendicular to the supraspinal ligament is an accurate, reliable and safe technique to treat simple fracture in the thoracic or lumbar spine.

Electro-optic modulator (EOM) is widely used in optical fiber Brillouin sensing system. However, the characteristics of EOM are sensitive to the external temperature change and mechanical vibration. It manifests a time-dependent drift of transmission curve, which leads to the decrease of extinction ratio and measurement accuracy of the sensing system. In order to set a stable EOM operation point for pulse modulation of input lightwave, an automatic bias control system with optical feedback is designed in this paper based on the observation of drift phenomenon of transmission curve and the measurement of half-wave voltage of EOM. This system can control the bias more precisely and steadily than the previous methods. Experimental results indicate that the extinction ratio of output pulse can be as high as more than 28 dB and keep stable in the whole measurement time of three hours with this system. The steady bias control and obtained high extinction ratio provide a foundation of high accuracy for optical-fiber Brillouin sensing system.

Osteoblast migration and proliferation are fundamental processes in bone healing. We demonstrated that the G-protein-coupled receptor kinase interacting protein 1(GIT1) is a key regulator of bone mass and osteoblast cell migration, but little is known about GIT1 regulation by upstream signaling systems or the impact of GIT1 on downstream effectors. We found that platelet-derived growth factor (PDGF) stimulated the GIT1 tyrosine phosphorylation in osteoblast cells and increased the association of GIT1 with focal adhesion kinase (FAK) at osteoblast focal adhesions. The Src inhibitor PP2 and FAK siRNA inhibited GIT1 tyrosine phosphorylation and the increased association between GIT1 and FAK following stimulation with PDGF. The spa2 homology domain (SHD) of GIT1 was required for association with FAK. Furthermore, phosphorylation of tyrosine 321 of GIT1, which is localized within the SHD, was critical for association with FAK. Mutagenesis analysis revealed that GIT1Y321F inhibited the increased association between GIT1 and FAK. Immunofluorescent staining revealed that GIT1Y321F inhibited FAK activation in focal adhesions after PGDF stimulation. A cell spreading assay demonstrated that GIT1Y321F also inhibited osteoblast cell motility, while the Boyden chamber assay demonstrated that the GIT1Y321F mutation inhibited PDGF-induced osteoblastic cell migration. Phosphorylation of tyrosine 321 of GIT1 is necessary for PDGF-induced association with FAK, FAK activation in focal adhesions, and for osteoblastic cell migration.

Background Osteoporotic vertebral compression fracture is a serious complication of osteoporosis. Various vertebral kyphoplasty surgeries, which have their own unique features, are commonly used for osteoporotic vertebral compression fracture. Based on the anatomic property of the thoracolumbar vertebral pedicle that its horizontal diameter is twice that of the vertical diameter, we designed Jack vertebral dilator for better restoration of the vertebral height by manipulating the mechanical force. Methods A total of 218 patients (236 vertebrae) with osteoporotic vertebral compression fracture were treated with Jack vertebral dilator. Surgery was successfully completed in all cases, and all the 218 patients were followed up for an average of 14.2 months (range 3 to 30 months). Results Bone cement leakage occurred in 12 cases, but no symptoms were reported. No other complications were noticed. The VAS scores were 8.2 ± 1.3, 1.7 ± 0.9, and 1.8 ± 0.8 and the ODI was 78.2 ± 13.3 %, 18.5 ± 7.3 %, and 20.9 ± 6.8 % before surgery and 1 week after surgery and at the final follow-up, respectively. The anterior vertebral body height was 19.3 ± 3.2, 25.1 ± 2.6, and 24.9 ± 2.6 mm and the central vertebral body height was 18.7 ± 3.0, 24.8 ± 3.0, and 24.5 ± 2.9 mm before surgery and 1 week after surgery and at the final follow-up, respectively. Cobb angle was 16.2° ± 6.6°, 8.1° ± 5.6°, and 8.5° ± 5.6° before surgery and 1 week after surgery and at the final follow-up, respectively. Conclusions Jack vertebral dilator kyphoplasty for osteoporotic vertebral compression fracture is safe, feasible, and effective and has the prospect of further broad application in the future. Electronic supplementary material The online version of this article (doi:10.1186/s13018-016-0371-4) contains supplementary material, which is available to authorized users.

In fires, people are easier to lose their mind. Panic will lead to irrational behavior and irreparable tragedy. It has great practical significance to make contingency plans for crowd evacuation in fires. However, existing studies about crowd simulation always paid much attention on the crowd density, but little attention on emotional contagion that may cause a panic. Based on settings about information space and information sharing, this paper proposes an emotional contagion model for crowd in panic situations. With the proposed model, a behavior mechanism is constructed for agents in the crowd and a prototype of system is developed for crowd simulation. Experiments are carried out to verify the proposed model. The results showed that the spread of panic not only related to the crowd density and the individual comfort level, but also related to people's prior knowledge of fire evacuation. The model provides a new way for safety education and evacuation management. It is possible to avoid and reduce unsafe factors in the crowd with the lowest cost.