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To solve the problem of low recognition accuracy of radar active jamming in strong noise environment,an algorithm for ER-C-L(Extended ResNet-CNN-LSTM) network model based on one-dimensional composite features is proposed. Firstly, the amplitude, instantaneous frequency, instantaneous envelope of power spectrum and their composite features are taken as network input to compare their recognition accuracy in ResNet-CNN model. The composite features of amplitude and instantaneous envelope of power spectrum with high detection probability and small data volume are selected as the optimal features. Then, the complex features are injammed into the ER-C-L network to identify six new active jamming models. Simulation experiments show that the recognition accuracy of jamming is 98.5% in strong noise environment within the JNR of -10 dB. Compared with other deep learning algorithms such as CNN, ResNet-CNN, extended ResNet-CNN and LSTM, it has higher interference recognition accuracy.

As one of the most critical and failure-prone parts of the mechanical systems of industrial equipment, bearings are subjected to high loads for long periods of time. When they fail or wear irreversibly, they may cause accidents or even huge economic losses. Therefore, effective health monitoring and fault diagnosis are of great significance to ensure safe and stable operation of industrial equipment. In order to further promote the development of bearing health monitoring and fault diagnosis technology, the current existing models and methods are analyzed and summarized, and the existing technologies are divided and compared. Starting from the distribution of vibration signal data used, firstly, the relevant methods under uniform data distribution are sorted out, the classification, analysis and summary of the current research status are carried out mainly according to signal-based analysis and data-driven-based, and the shortcomings and defects of the fault detection methods in this case are outlined. Secondly, considering the problem of uneven data acquisition under actual working conditions, the detection methods for dealing with such cases are summarized, and different processing techniques for this problem in existing research are classified into data processing methods, feature extraction methods, and model improvement methods according to their different focuses, and the existing problems are analyzed and summarized. Finally, the challenges and future development directions of bearing fault detection in existing industrial equipment are summarized and prospected.

BackgroundNatural circulation systems are widely used in the nuclear industry for decay heat removal, post-accident containment cooling, and the cooling of radioactive waste storage facilities. Because a large number of spent fuel assemblies are densely arranged in the spent fuel pool, the spent fuel assemblies in the central area of the spent fuel pool can be approximated as having adiabatic boundary conditions. In the event of a coolant loss accident, the heat generated by the spent fuel assemblies can be exported only by the natural circulation of air.PurposeThis study aims to develop analytical models for fuel assembly natural circulation characteristics independent of the results of computational fluid dynamics (CFD) to investigate the natural circulation characteristics of spent fuel pools following a coolant loss accident.MethodsBased on the experimental results of a fuel assembly pressure drop of a full-scale pressurized water reactor (PWR), the Darcy–Forchheimer model was firstly revised to predict the pressure drop of humid air flowing through the fuel assembly. Models for the fuel assembly natural circulation flow rate and peak cladding temperature were then established, and the effects of the relative humidity of air on the models were considered. Finally, these models were applied to investigating effects of total heating power, ambient temperature, and relative humidity on the natural circulation flow rate and peak cladding temperature of the fuel assembly.ResultsThe results show that the models accurately predict the natural circulation flow rate and peak cladding temperature of the fuel assembly under different heating powers, and the errors are less than 25% and 20%, respectively, as compared with the experimental measurement values.ConclusionsThe developed models in this study can be used to study the natural circulation characteristics of full-scale PWR fuel assemblies.

BackgroundPassive residual heat-removal system (PRHRS) based on natural circulation has been widely used in small reactors connected on secondary side loop.PurposeThis study aims to develop and analyze a passive residual heat-removal system on the secondary side of a small reactor to improve reactor safety.MethodsBased on the completed heat-transfer experiment of the intermediate circuit of a small integrated nuclear power plant, Reactor Excursion and Leak Analysis Program (RELAP) was employed to determine and analyze the natural circulation characteristics of the intermediate loop were determined and analyzed.ResultsThe heat transfer rate results of the program are in good agreement with the experimental data, and the natural cycle characteristics of PRHRS can be characterized. The pressure of the system loop is determined by the average temperature of the primary side of the steam generator (SG), and the difference in the inlet temperature of the SG primary side, mass flow rate, and height of the cooling and heating sources significantly influence the heat-transfer performance of the SG system. The heat-transfer performance of the waste-heat-removal system is more sensitive to the resistance of the system loop when the temperature of the primary-side inlet of the SG is higher.ConclusionsThese results provide a valuable application for further investigations of passive systems in small reactors.

The helical-coiled once-through steam generator (H-OTSG) is widely used in small modular reactors due to its compactness and higher heat transfer efficiency. In this study, an experimental and numerical simulation study of the thermalhydraulics characteristics of HOTSG under different thermal power conditions was carried out, and the experimental results were used to verify the onedimensional system code SGTH1D. The configuration consists of 85 helically coiled tubes divided into ten layers according to the coil diameter. Both steadystate experiments and flow instability experiments were conducted under thermal power condition ranging from 06 MW to 23 MW. Firstly, the steadystate experimental results show the difference between the shellside inlet temperature and the tubeside outlet temperature increases with thermal power, which is due to the decreasing of the heat transfer capacity of the HOTSG. Sensitivity analysis of the system parameters shows that the shellside pressure has little effect on the average heat transfer coefficient. And the average heat transfer coefficient also is insensitive to tubeside pressure and shellside inlet temperature under low thermal power conditions. However, under low thermal power conditions, the average heat transfer coefficient increases with the decrease of the tubeside pressure and the increases of the shellside inlet temperature. Secondly, the flow instability experimental results show that the increase of the thermal power can stabilize the HOTSG and decrease the inlet throttling of the flow instability thresholds because the length of the subcooled singlephase region increases with the thermal power. The sensitivity analysis of the system parameters shows that the increase of the tubeside pressure and the decrease of the shellside inlet temperature are beneficial to the stability of the system. The influence of the shellside parameters on the flow instability threshold is weaker than that of the tubeside parameters. Finally, a numerical study on the thermal-hydraulics characteristics of the configuration was carried out in the present study. By comparing the experimental data with the numerical simulation results of the SGTH1D code, the accuracy of the SGTH1D code in predicting the steadystate heat transfer characteristics and flow instability of configuration was verified. The SGTH1D code can accurately predict the heat transfer rate of the HOTSG under various thermal power conditions, and the prediction errors of shellside and tubeside outlet temperatures are within ±1 ℃. The numerical results of flow instability characteristics of the SGTH1D code are conservative at low thermal power condition, and the error of numerical results is within ±20% when the thermal power is larger than 12 MW.

Helically coiled tube (HCT) is widely used in nuclear engineering and other fields due to its effective compactness, excellent structure robustness, heat transfer efficiency and flow stability. As one of the most important gasliquid twophase flow patterns in HCT, the characteristic of annular flow has a great influence on the heat transfer performance of helical oncethrough steam generator. Especially, the circumferential distribution of liquid film thickness in annular flow directly determines the dryout onset location. Although the liquid film flow in straight tubes has been extensively studied, due to the limitation of measurement technology, the precise measurement data of liquid film thickness in HCT are still very rare. In this paper, based on the selfdeveloped noninvasive contact ringisland array sensor (RIAS), airwater twophase flow experiments were carried out to study the threedimensional spatialtemporal distribution of liquid film thickness in vertical HCT with different structures. According to the results, four typical liquid film flow regimes were defined based on the circumferential position of the thicker liquid film appearing in the tube wall. That is, the bottom distribution (BD) dominated by gravity force, the outside distribution (OD) dominated by liquid centrifugal force, the inside distribution (ID) dominated by gas centrifugal force and the insideoutside distribution (IOD) dominated by secondary flow. The effects of coil diameter and coil pitch of HCT as well as gas and liquid velocities on the distribution of liquid film flow regimes were detailed analyzed. It is implied that the coil diameter determines the intensity of centrifugal force and secondary flow. Generally, the smaller the coil diameter, the easier the circumferential distribution forms of OD, ID and IOD are to appear. Also, increasing the coil pitch weakens the effect of centrifugal force on the liquid film. Then a small coil pitch normally results in the circumferential distribution form of OD while it is ID for large coil pitch. It is also found that the IOD occurs only when both gas and liquid velocities are large enough. By taking the influence of HCT geometry and fluid parameters into account, a general submap of liquid film flow in HCT was proposed using the modified Dean number De* and the modified LockhartMartinelli parameter X*. The transition criteria between different liquid film flow regimes were also established and verified with experimental data in present work and previous references. From this work, the mechanism of curvatureinduced centrifugal force and secondary flow on the spatiotemporal evolution of liquid film in HCT is revealed.

Traditional orchard production is facing problems of labor shortage due to the aging, difficulties in the management of agricultural equipment and production materials, and low production efficiency which can be expected to be solved by building a smart orchard that integrates technologies of Internet of Things(IoT), big data, equipment intelligence, et al. In this study, based on the objectives of full mechanization and intelligent management, a smart orchard was built in Pinggu district, an important peaches and pears fruit producing area of Beijing. The orchard covers an aera of more than 30 hm2 in Xiying village, Yukou town. In the orchard, more than 10 kinds of information acquisition sensors for pests, diseases, water, fertilizers and medicines are applied, 28 kinds of agricultural machineries with intelligent technical support are equipped. The key technologies used include: intelligent information acquisition system, integrated water and fertilizer management system and intelligent pest management system. The intelligent operation equipment system includes: unmanned lawn mower, intelligent anti-freeze machine, trenching and fertilizer machine, automatic driving crawler, intelligent profiling variable sprayer, six-rotor branch-to-target drone, multi-functional picking platform and finishing and pruning machine, etc. At the same time, an intelligent management platform has been built in the smart orchard. The comparison results showed that, smart orchard production can reduce labor costs by more than 50%, save pesticide dosage by 30% ~ 40%, fertilizer dosage by 25% ~ 35%, irrigation water consumption by 60% ~ 70%, and comprehensive economic benefits increased by 32.5%. The popularization and application of smart orchards will further promote China's fruit production level and facilitate the development of smart agriculture in China.

To realize the autonomous navigation and automatic target spraying of intelligent plant protect machinery in orchard, in this study, an autonomous navigation and automatic target spraying robot for orchards was developed. Firstly, a single 3D light detection and ranging (LiDAR) was used to collect fruit trees and other information around the robot. The region of interest (ROI) was determined using information on the fruit trees in the orchard (plant spacing, plant height, and row spacing), as well as the fundamental LiDAR parameters. Additionally, it must be ensured that LiDAR was used to detect the canopy information of a whole fruit tree in the ROI. Secondly, the point clouds within the ROI was two-dimension processing to obtain the fruit tree center of mass coordinates. The coordinate was the location of the fruit trees. Based on the location of the fruit trees, the row lines of fruit tree were obtained by random sample consensus (RANSAC) algorithm. The center line (navigation line) of the fruit tree row within ROI was obtained through the fruit tree row lines. The robot was controlled to drive along the center line by the angular velocity signal transmitted from the computer. Next, the ATRS's body speed and position were determined by encoders and the inertial measurement unit (IMU). And the collected fruit tree zoned canopy information was corrected by IMU. The presence or absence of fruit tree zoned canopy was judged by the logical algorithm designed. Finally, the nozzles were controlled to spray or not according to the presence or absence of corresponding zoned canopy. The conclusions were obtained. The maximum lateral deviation of the robot during autonomous navigation was 21.8 cm, and the maximum course deviation angle was 4.02°. Compared with traditional spraying, the automatic target spraying designed in this study reduced pesticide volume, air drift and ground loss by 20.06%, 38.68% and 51.40%, respectively. There was no significant difference between the automatic target spraying and the traditional spraying in terms of the percentage of air drift. In terms of the percentage of ground loss, automatic target spraying had 43% at the bottom of the test fruit trees and 29% and 28% at the middle of the test fruit trees and the left and right neighboring fruit trees. But in traditional spraying, the percentage of ground loss was, in that sequence, 25%, 38%, and 37%. The robot developted can realize autonomous navigation while ensuring the spraying effect, reducing the pesticides volume and loss.

Objective The process of spermatogenesis is complex involving multiple regulatory mechanisms and requiring complex interactions between germ cells and somatic cells. The mechanisms of Sertoli cells involving in spermatogenesis remain to be explored. Methods We collected single-cell RNA sequencing data from a high-throughput gene expression database (GEO: GSE113293) from wild-type C57BIL6J male mice with normal spermatogenesis and four different mutant mouse strains (knockout Mlh3, Hormadl, and Cul4a; Cnp transgene). Then bioinformatics analyses such as gene function enrichment analysis (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) enriched pathway analysis, protein- protein interaction (PPI) network analysis, transcription factor regulation analysis (SCENIC), and gene set variation analysis (GSVA) on the Sertoli cells were further indentified. Results We identified nine subtypes of spermatogenic cell clusters (undiferentiated spermatogonia, diferentiating sperrmatogonia, leptotene/zygotene, pachytene, diplotene, round sperrmatids, elongating spermatids, and spermatozoa), and two types of somatic cell clusters (Leydig cells, and Sertoli cells), and one unknown type of cell cluster. Compared to the normal spermatogenesis model, 276 genes were upregulated and 234 genes were downregulated in the Sertoli cells of the mouse spermatogenesis defect model. GO analysis showed that differential genes in Sertoli cells were significantly enriched in spermatogenesis and energy metabolism. KEGG enrichment analyses showed that the homogeneous ribosomal pathway, glycolytic pathway, and oxidative phosphorylation pathway were significantly enriched in Sertoli cells. Protein-protein interaction (PPI) network analysis of diferentially expressed genes identified 20 hub genes, all of which belonged to ribosomal genes, and GSVA analysis revealed that the upregulated genes in Sertoli cells were closely related to the Notch signaling pathway. Conclusion The hub genes and the Notch signaling pathway in Sertoli cells are involved in the process of spermatogenesis. This study provides new perspectives on infertility caused by spermatogenesis dis orders. [ABSTRACT FROM AUTHOR]

Due to the compact structure, high heat transfer efficiency and strong reliability, helical coil once-through steam generator (HCSG) is widely used in advanced small reactors. In HCSG, the liquid in the tube side is heated by the helical coils so that subcooled water in the tube side is transferred into superheated steam, and the entire heat transfer regime is covered. Moreover, the evolution mechanism of thermalhydraulic behaviors is complex because it is affected by the helical geometry, the centrifugal force and the secondary flow. Hence, the development of advanced HCSG was limited due to the lack of more accurate models of heat transfer and regime transition. With the financial support of the three major nuclear power groups in China, experimental and theoretical research on heat and mass transfer behaviors in helical coils was carried out systematically. Different helical coils were investigated and comprehensive parametric analysis of heat transfer was conducted to provide a better understanding of different heat transfer regimes. According to our research, a fundamental database of heat transfer and flow resistance in helical coils with a wide range of geometric dimensions and thermalhydraulic parameters was established. In addition, the transition pattern of the circumferential nonuniform heat transfer mechanism was clarified. Due to the secondary flow, it consequently leaded to the nonuniform distribution of flow field. The heat transfer and flow resistance characteristics were notably affected by the special behaviors of liquid in the helical coils. Hence, based on mechanism analysis, several models were proposed to construct a high precision library of allregime prediction model, such as a threeregion dryout quality model, a postdryout heat transfer model based on dryness gradient and a widerange model for twophase frictional multiplier factor. For the model of dryout quality, it takes the relative intensity of gravity, buoyancy and centrifugal force into consideration. Since different dominant forces lead to different heat transfer behaviors, a piecewise correlation is established to give more accurate predictions. As for the postdryout heat transfer model, it considers the influence of dryness gradient and achieves a more accurate prediction. For the twophase pressure drop model, the modified frictional multiplier factor is adjusted according to our database. Then, a prediction model was proposed which was also validated by other researchers and had great prediction accuracy in a wide range. In all, this work includes part of our investigation on the heat transfer of helical coils and provides a highprecision prediction in the entire heat transfer regime, which meets the design requirement of HCSG for advanced reactors.

The fluorescence quantum yield (Φf), molar extinction coefficient (ε), and electrogenerated chemiluminescence (ECL) of perylene monoimide alcohol ester derivatives (PMDs) were characterized by UV-Vis spectroscopy, fluorescence spectroscopy and cyclic voltammetry (CV) charge trapping technique under identical conditions. The results showed that the Φf values of n-propylPMI, ethylPMI and PMD(1~4) were 0.96, 0.98, 0.94, 0.93, 0.91 and 0.89. ECL test results displayed that the luminescence intensity of PMD-2 was the highest, followed by that of PMD-4. The anhydride bond esterification affected the fluorescence quenching less, and only the derivatives spectral peaks were shifted. In the CV curves of PMD(1~4) the oxidation peaks disappeared, and those of PMD-2, and PMD-4 exhibited only reduction peaks.

To explore the reasonable pillar width of roadway along goaf in inclined coal seam, theoretical analysis, numerical simulation and industrial test are combined to carry out the research. The results show that the influence range of stress field in inclined coal seam is 12.2 m to 12.8 m by establishing the basic roof mechanics model of roadway along goaf; the distribution characteristics of deviating stress in surrounding rock of roadway under different widths of coal pillar are numerically simulated, and the reasonable narrow coal pillar width is determined to be 10 m; then the asymmetric surrounding rock control under the coupling action of roof pre-stressed bolt + high strength single bolt cable + truss bolt cable support is proposed. The results of field observation show that the surrounding rock of roadway is stable.

BackgroundAs a nuclear power system with high energy density and strong adaptability, heat pipe cooled reactor can play an important role in space and deep sea exploration, and is attracting more and more attention from all over the world. Due to the solid-state core and high-temperature operation of the heat pipe cooled reactor, the thermal expansion and thermal stress are non-negligible. The nuclear-thermal-mechanical coupling effect should be considered for the heat pipe cooled reactor core.PurposeThis study aims to investigate the thermal-mechanical characteristics of the reactor core, and evaluate the safety performance of the reactor under typical conditions and transient accidents for a typical heat pipe cooled nuclear reactor, Nuclear Silence ThermoElectric Reactor (NUSTER).MethodsBased on FLUENT and MECHANICAL modules in finite element analysis software ANSYS, calculation of the nuclear-thermal-mechanical coupling was conducted for the reactor core of NUSTER under the steady-state and the reactor reactivity insertion accident respectively, hence the temperature and stress distribution were obtained. The core design safety was evaluated by comparing the temperature and stress peak values of each component with the melting point and yield strength of material.Results & ConclusionThe comparison results show that NUSTER core can operate safely within the safety limit in both steady state and accident conditions. Each component has a safety margin of 200 K for temperature and 150 MPa for stress under accident condition, so the core design safety has been verified.

Objective To investigate the clinical and pathological features of adenoid basal cell carcinoma (ABC), adenoid cystic carcinoma (ACC), and basaloid squamous cell carcinoma (BSCC) with basaloid characteristics and improve the diagnostic and differential diagnostic ability of clinicians and pathologists for these lesions. Methods A retrospective study was conducted on the clinical and pathological data of 4 cases of ABC, 1 case of ACC, and 3 cases of BSCC diagnosed and treated at Shenzhen Maternal and Child Health Hospital, Southern Medical University from April 2018 to December 2022. Pathological slides were reviewed and relevant literature was analyzed and summarized. Results All three types of tumors were common in postmenopausal women and were associated with high-risk HPV infection. ABC was a low-grade cancer and patients were often clinically asymptomatic. It was usually detected incidentally during cervical screening due to cytological abnormalities, or after cervical cone biopsy or hysterectomy for HSIL. It presented as superficial cervical infiltration and clinical staging was often early. ACC and BSCC were intermediate to high-grade cancers and they often presented with postmenopausal vaginal bleeding. A visible mass was observed on the cervix. The clinical staging was intermediate to advanced. The three types of lesions could coexist. Careful observation of the morphological characteristics and immunohistochemical staining could help with differential diagnosis. None of the 8 patients experienced recurrence or metastasis during follow-up. Conclusion Cervical ABC, ACC and BSCC are rare and they originate from reserve cells. They share the similarities in clinical and pathological morphology, but differ in treatment and prognosis. So, accurate differentiation among them has important clinical significance. [ABSTRACT FROM AUTHOR]

Fermentation is a key process for the formation of black tea quality, and the fermentation conditions are the important factors affecting the degree of fermentation. In order to optimize the parameters of a self-designed roller fermentation machine, the extended distinct element method (EDEM) was used to simulate three distinct gradients of the rotational speed of the flexible scraper, and compare the degree of uniformity. With sensory score as evaluation index, response surface method (RSM) was applied for optimizing three key factors affecting fermentation quality (fermentation temperature, fermentation time, stirring interval). The results indicate that the uniformity of fermentation was the best at a rotation speed of 36(°)s-1. Based on this rotational speed, the order of importance of each factor on fermentation quality was: fermentation time, fermentation temperature, stirring interval. The optimal process parameters were as follows: fermentation time, 230 min, fermentation temperature, 28.5 C, and stirring interval, 20 min. [ABSTRACT FROM AUTHOR]

The moving system is the most critical part of numerical control（ NC for short） forming machine to achieve its fundamental function,but also the most importent part that affect the processing accuracy. The moving system of forming machine were lightweight designed firstly. Based on lightweight design principles,aluminum material was adopted on its key components of Y and Z axis,and the sandwich structure which has advantages of lightweight core and large inertia moment. Then structural static analysis and mode analysis of moving system were done by using the method of FEM numerical simulation,and the engineering verification was carried out. Results of the study show that the strength and stiffness of the moving system can satisfy the use requirement and allowable conditions of the forming machine.

Objective: To introduce a new occipitocervical angle parameter, occipito-odontoid angle (O-Da), for predicting dysphagia after occipitocervical fusion (OCF) in patients with C 2, 3 Klippel-Feil syndrome (KFS) and analyze its effectiveness., Methods: A total of 119 patients met selective criteria between April 2010 and November 2019 were retrospectively included as the study subjects. There were 56 males and 63 females. The age ranged from 14 to 76 years, with a median age of 51 years. There were 44 cases of basilar invagination and 75 cases of atlantoaxial subluxation. Forty patients were combined with C 2, 3 KFS. Seven patients underwent anterior decompression combined with posterior OCF and 112 patients underwent posterior OCF. The fixed segments were O-C 2 in 36 cases, O-C 3 in 51 cases, O-C 4 in 25 cases, and O-C 5 in 7 cases. All patients were followed up 21-136 months, with a median time of 79 months. The lateral cervical X-ray films before operation and at last follow-up were used to measure the occipital to C 2 angle (O-C 2 a), the occipital and external acoustic meatus to axis angle (O-EAa), the occipital protuberance to axial angle (Oc-Axa), the O-Da, and the narrowest oropharyngeal airway space (nPAS). The differences of the above parameters between the last follow-up and the preoperative values were calculated (represented as dO-C 2 a, dO-EAa, dOc-Axa, dO-Da, and dnPAS). Patients were divided into two groups according to whether they suffered dysphagia after operation, and the differences in clinical data and radiographic parameters were compared between the two groups. The correlation between occipitocervical angle parameters and nPAS in 40 patients with C 2, 3 KFS was analyzed respectively. In addition, sensitivity and specificity analyses were used to assess the effectiveness of dO-Da≤-5° for the prediction of postoperative dysphagia., Results: Thirty-one patients (26.1%) suffered dysphagia after OCF (dysphagia group), including 10 patients with C 2, 3 KFS; no dysphagia occurred in 88 patients (non-dysphagia group). There was no significant difference in age, follow-up time, fixed segment, proportion of patients with rheumatoid arthritis, proportion of patients with atlantoaxial subluxation, and proportion of patients with C 2, 3 KFS between the two groups ( P >0.05). The proportion of female patients was significantly higher in dysphagia group than in non-dysphagia group ( χ 2 =7.600, P =0.006). The difference in preoperative O-C 2 a between the two groups was significant ( t =2.528, P =0.014). No significant differences were observed in preoperative O-EAa, Oc-Axa, O-Da, and nPAS ( P >0.05). There was no significant difference in dO-C 2 a, dO-EAa, dOc-Axa, dO-Da, and dnPAS between the two groups ( P >0.05). The dO-C 2 a, dO-EAa, dOc-Axa, and dO-Da were positively correlated with dnPAS in 40 patients with C 2, 3 KFS ( r =0.604, P <0.001; r =0.649, P <0.001; r =0.615, P <0.001; r =0.672, P <0.001). Taking dO-Da≤-5° as the standard, the sensitivity and specificity of dO-Da to predict postoperative dysphagia in patients with C 2, 3 KFS were 80.0% (8/10) and 93.3% (28/30), respectively., Conclusion: The dO-Da is a reliable indicator for predicting dysphagia after OCF in patients with C 2, 3 KFS.

Objective: To develop a smart orthosis personalized management system for the treatment of patients with adolescent idiopathic scoliosis (AIS) and to evaluate the feasibility and efficiency through clinical preliminary applications., Methods: The smart orthosis personalized management system consists of a wireless force monitor, a WeChat Mini Program, a cloud-based storage system, and a website backstage management system. Twenty-two patients with AIS who underwent orthosis treatment and met the selection criteria between March 2020 and December 2020 were enrolled. The follow-up time was 4 months. The parameters used to evaluate patients' compliance were as follows (back and lumbar): baseline force value, measured force value, force compliance (measured force value/baseline force value×100%), measured wearing time (wearing time of force value was more than 0 N), and time compliance (measured wearing time/prescribed wearing time×100%), in which the prescribed wearing time was 23 hours/day. The baseline force values were measured at initiation, while the measured force value, measured wearing time, force compliance, and time compliance were measured during follow-up. The differences of these parameters between back and lumbar, and the differences among these parameters at 1, 2, 3, and 4 months after orthosis wearing were analyzed., Results: The average measured force value of 22 patients (back and lumbar) was (0.83±0.34) N, the average force compliance was 68.5%±17.9%, the average measured wearing time was (15.4±1.7) hours, and the average time compliance was 66.9%±7.7%. The baseline force value and measured force value of back were significantly higher than those of lumbar ( P <0.05); the measured wearing time, force compliance, and time compliance between back and lumbar showed no significant difference ( P >0.05). The measured force value, measured wearing time, force compliance, and time compliance at 1 month after wearing were significantly lower than those at 2, 3, and 4 months after orthosis wearing ( P <0.05), no significant difference was found among 2, 3, and 4 months after orthosis wearing ( P >0.05). At different time points after wearing, the measured force value of back were significantly higher than that of lumbar ( P <0.05), while there was no significant difference between back and lumbar on the other parameters ( P >0.05)., Conclusion: The smart orthosis personalized management system has high feasibility to treat AIS, and can improve the compliance of such patients with orthosis wearing.

Objective: To compare the predictive abilities of O-C2 angle (O-C2a), O-EA angle (O-EAa), and Oc-Ax angle (Oc-Axa) for development of dysphagia in patients after occipitocervical fusion (OCF)., Methods: Between April 2010 and May 2019, 114 patients who underwent OCF and met the selection criteria were selected as the research objects. Among them, 54 were males and 60 were females; they were 14-76 years old, with an average of 50.6 years old. The follow-up time was 13-122 months (median, 60.5 months). The O-C2a, O-EAa, Oc-Axa, and the narrowest oropharyngeal airway space (nPAS) were measured by the lateral X-ray films before operation and at last follow-up, and the differences before and after operation (dO-C2a, dO-EAa, dOc-Axa, and dnPAS) were calculated. Patients were divided into two groups according to whether they had developed postoperative dysphagia. The general data including age, gender, fixed segment, proportion of patients with rheumatoid arthritis (RA), atlantoaxial subluxation (AS), and combined with anterior release surgery (ARS), and imaging indicators were compared between the two groups. The correlations between dO-C2a, dO-EAa, and dOc-Axa and dnPAS in 114 patients were analyzed to further compare the predictive value of three imaging indicators for occurrence of dysphagia after OCF., Results: Dysphagia occurred after OCF in 31 cases with the incidence of 27.2%. There was significant difference in gender between the dysphagia group and the non-dysphagia group ( χ 2 =7.940, P =0.005). There was no significant difference between the two groups in age, fixed segment, the proportion of patients with RA, the proportion of patients with AS, and the proportion of patients combined with ARS ( P >0.05). There was no significant difference in O-C2a and Oc-Axa of 114 patients before operation and at last follow-up ( P >0.05). The differences in O-EAa and nPAS were significant ( P <0.05). There was no significant difference in preoperative O-EAa, Oc-Axa, and nPAS between the dysphagia group and the non-dysphagia group ( P >0.05); the difference in the O-C2a was significant ( t =2.470, P =0.016). At last follow-up, the differences in the above imaging indicators were significant ( P <0.05). There were significant differences in the dO-C2a, dO-EAa, dOc-Axa, and dnPAS between the two groups ( P <0.05). Correlation analysis showed that the dO-C2a, dO-EAa, dOc-Axa were all positively correlated with dnPAS ( P <0.05). The dO-C2a≤-5°, postoperative O-EAa≤100°, postoperative Oc-Axa≤65° were all related to postoperative dysphagia ( P <0.05), and the highest risk factor suffering postoperative dysphagia was dO-C2a ≤-5° with a significant OR of 14.4., Conclusion: The dO-C2a, postoperative O-EAa, and postoperative Oc-Axa can be used as the predictive indexes of dysphagia after OCF, among which dO-C2a has the highest predictive value.

Objective: To summarize the research progress of hydrogels for the regeneration and repair of degenerative intervertebral disc and to investigate the potential of hydrogels in clinical application., Methods: The related literature about the role of hydrogels in intervertebral disc degeneration especially for nucleus pulposus was reviewed and analyzed., Results: Hydrogels share similar properties with nucleus pulposus, and it plays an important role in the regeneration and repair of degenerative intervertebral disc, which can be mainly applied in nucleus pulposus prosthesis, hydrogel-based cell therapy, non-cellular therapy, and tissue engineering repair., Conclusion: Hydrogels are widely used in the regeneration and repair of intervertebral disc, which provides a potential treatment for intervertebral disc degeneration.

Objective: To discuss the effectiveness of atlantoaxial joint release through anterior retrophayngeal approach and staged posterior reduction fixation and fusion for irreducible atlantoaxial dislocation (IAAD)., Methods: Fifteen patients with IAAD (9 males, 6 females), aged 14-53 years (mean, 31.4 years) were included in the study. The disease duration was 3 months to 17 years (mean, 5.7 years). IAAD was attributed to trauma in 13 cases, and 2 cases were caused by congenital odontoid disconnection. Preoperative imaging examination showed atlantoaxial dislocation and could not be reset automatically in functional position. The preoperative visual analogue scale (VAS) score was 3-7 (mean, 4.1), and the preoperative Japanese Orthopaedic Association (JOA) score was 10-17 (mean, 13.8). All patients received atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion., Results: Anatomical reduction was achieved in all 15 patients, and the alignment of atlantoaxial joints was restored. After operation, the neck pain and neurological symptom were partially or fully improved in all patients, without deterioration of neurological function. One patient developed pharyngeal discomfort and cough after one-stage operation, 4 patients developed pharyngeal discomfort and foreign body sensation after operation, and 2 patients developed pin-path lipstick swelling during skull traction. All patients were cured by symptomatic treatment. No pulmonary infection, pressure ulcers, venous thrombosis, and incision infection was found during the treatment. All 15 patients were followed up 24-36 months, with an average of 28.6 months. Bony fusion was achieved in all patients, and the fusion time was 3-5 months, with an average of 3.6 months. At last follow-up, the VAS score was 0-2 (mean, 0.5) and the JOA score was 13-17 (mean, 15.9). There was no dislocation, recurrence, or other abnormal sign in the cervical X-ray films and three-dimensional CT., Conclusion: Anatomical reduction can be achieved by atlantoaxial joint release through anterior retrophayngeal approach and staged posterior fixation and fusion for treating IAAD. It is an optional procedure for IAAD.

Objective: To research the biological characteristics of different generations of rabbit nucleus pulposus cells (NPCs) that were cultured with natural culture and subculture method., Methods: The thoracolumbar segments of New Zealand white rabbits (6-8 weeks old and weighing 1.5-2.5 kg) were obtained and nucleus pulposus were isolated from disc regions. And NPCs were harvested by enzymatic digestion from nucleus pulposus. Primary NPCs were counted as P0 generation. Then, NPCs were passaged by trypsin and counted as P1, P2, P3 with a totle of 4 generations. P0 to P3 generations NPCs were separately examined by observation of cell morphology and proliferation time, detection of apoptosis rates of cells by flow cytometry, and detection of hypoxia-inducible factor 1α (HIF-1α), matrix metalloproteinases 2 (MMP-2), Aggrecan, and collagen type Ⅱ proteins by immunofluorescence and Western blot., Results: The morphology of NPCs transformed from triangular or polygonal in P0 generation to spindle in P3 generation; the characteristic vacuolated cells gradually disappeared; and the cell volume and cell proliferation time increased. The cell apoptosis rates were 5.47%±0.91%, 13.77%±2.42%, 33.46%±1.82%, and 38.76%±1.50% from P0 to P3 generations, with the increase of culture time, and there were significant differences between 4 generations ( P <0.05). Immunofluorescence staining showed that with the increase of cells generation, the fluorescence intensity of HIF-1α, collagen type Ⅱ, and Aggrecan decreased, and the fluorescence intensity of MMP-2 increased. Western blot results showed that the relative expression of HIF-1α protein was high in P0 generation, the P1 generation has a rising trend, and then gradually decreased; the differences between generations were significant ( P <0.05). The relative expression of collagen type Ⅱ protein decreased from P0 to P3 generations and there were significant differences between generations ( P <0.05). The relative expression of Aggrecan protein decreased from P0 to P2 generations and there were significant differences between generations ( P <0.05); but no significant difference was found between P2 and P3 generations ( P >0.05). The relative expression of MMP-2 protein increased significantly in P3 generation; except that the difference between P0 and P2 generations was not significant ( P >0.05), the significant differences were found between the other generations ( P <0.05)., Conclusion: Rabbit NPCs degeneration model was successfully established by the natural culture and subculture method. Transforming of NPCs morphology, increasing of cell apoptosis rates, decreasing of anabolism, and increasing of catabolism were presented in NPCs degeneration model.

Objective: To evaluate the effectivity and safety of posterior osteotomy for thoracolumbar stress fracture in ankylosing spondylitis (AS) through the gap of a pathological fracture., Methods: Between April 2012 and August 2015, 8 patients with AS combined with thoracolumbar stress fracture were treated with posterior osteotomy through the gap of a pathological fracture to correct the kyphosis. There were 7 males and 1 female, with an average age of 51 years (range, 37-74 years). The history of AS was 1-40 years (mean, 21.7 years) and disease duration of stress fracture was 2-60 months (mean, 18.5 months). The segmental lesions included T 8, 9 in 1 case, T 10, 11 in 2 cases, T 11 in 2 cases, T 12 , L 1 in 1 case, L 1, 2 in 1 case, and L 2, 3 in 1 case. The nerve function before operation according to Frankel grading was grade D in 3 cases and grade E in 5 cases. The pre- and post-operative X-ray films, CT three-dimensional reconstruction, and MRI were collected to measure the global kyphosis (GK), local kyphosis (LK), angle of the fusion levels (AFL), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Visual analogue scale (VAS) score was used to assess the back pain intensity., Results: The operation time was 210-320 minutes (mean, 267 minutes), and the intraoperative blood loss was 400-2 000 mL (mean, 963 mL). Cerebrospinal fluid leakage was found in 3 patients, and the wound healed by removal of drainage tube and suturing drainage outlet after 5-7 days of operation. The wounds of the rest patients healed by first intention. Lower extremity numbness occurred in 1 case and recovered after 1 month of postoperative administration of oral mecobalamin. All the patients were followed up 20-43 months (mean, 28.4 months). No internal fixator loosening, fracture, and other complications occurred. All the fractures healed with the healing time of 3-12 months (mean, 6.8 months). At 3 months after operation, 3 cases with spinal cord injury of preoperative Frankel grade D recovered to grade E. The GK, LK, AFL, PI, PT, SVA, and VAS scores at 1 week after operation and at last follow-up were significantly improved when compared with preoperative ones ( P <0.05). Except for VAS score at last follow-up was significantly improved when compared with that at 1 week after operation ( P <0.05), there was no significant difference in the other indexes between at 1 week after operation and at last follow-up ( P >0.05)., Conclusion: Posterior osteotomy through the gap of a pathological fracture is a safe and effective surgical procedure for kyphosis correction and relief of back pain in AS patients combined with thoracolumbar stress fracture. Successful bony fusion and good clinical outcomes can also be achieved by this surgical procedure.

Objective: To explore the feasibility of co-transduction and co-expression of Nogo extracellular peptide residues 1-40 (NEP1-40) gene and neurotrophin 3 (NT-3) gene into neural stem cells (NSCs)., Methods: NSCs were derived from the cortex tissue of Sprague Dawley rat embryo. The experiment included 5 groups: no-load lentiviral vector transducted NSCs (group A), NEP1-40 transducted NSCs (group B), NT-3 transducted NSCs (group C), NEP1-40 and NT-3 corporately transducted NSCs (group D), and blank control (group E). Target genes were transducted into NSCs by lentiviral vectors of different multiplicity of infection (MOI; 5, 10, 15) for different time (24, 48, 72 hours). Fluorescent microscope was used to observe the expression of fluorescence protein and acquire the optimum MOI and optimum collection time. Real-time fluorescence quantitative PCR and Western blot tests were utilized to evaluate the gene expressions of NEP1-40 and NT-3 in NSCs and protein expressions of NEP1-40 and NT-3 in NSCs and in culture medium., Results: The optimum MOI for both target gene was 10 and the optimum collection time was 48 hours. The real-time fluorescence quantitative PCR and Western blot results showed that the mRNA and protein relative expressions of NEP1-40 in groups B and D were significantly higher than those in groups A and C ( P <0.05), but no significant difference was found between groups B and D, and between groups A and C ( P >0.05). The mRNA and protein relative expressions of NT-3 in groups C and D were significantly higher than those in groups A and B ( P <0.05), but no significant difference was found between groups A and B, and between groups C and D ( P >0.05)., Conclusion: NEP1-40 and NT-3 gene can be successfully co-transducted into NSCs by the mediation of lentiviral vector. The expressions of the two target genes are stable and have no auxo-action or antagonism between each other.

Objective: To summarize the research progress of the regulation effect of hypoxia inducible factor (HIF) on intervertebral disc., Methods: The domestic and foreign related literature about the regulation effect of HIF on intervertebral disc was reviewed, summarized, and analyzed., Results: HIF is a key transcription factor that is in response to hypoxia by cells, which is widely distributed in tissues and organs, including intervertebral disc. Hypoxia inducible factor is expressed highest in the nucleus pulposus which has the lowest oxygen concentration in the intervertebral disc. The effects of HIF include the regulation of nucleus pulposus differentiation and development, maintenance of the survival, energy metabolism, and anabolism of nucleus pulposus cells, and maintenance of the stability of extracellular matrix., Conclusions: HIF plays a vital role in the development and differentiation of intervertebral disc and maintenance of physiological function, which may become a target for the research of the mechanism and the treatment of intervertebral disc degeneration.

Objective: To discuss the early effectiveness of polyaminoacid/nano-hydroxyapatite/calcium sulfate (PAA/HA/CS) Cage (PHC Cage) in lumbar fusion surgery., Methods: Thirty cases undergoing lumbar fusion of single segment between March and September 2014 were enrolled in this study. The patients were randomly divided into the trial group (n = 20) and the control group (n = 10). The PHC Cage was implanted in the trial group, while the polyetheretherketone (PEEK) Cage was implanted in the control group. The patients of 2 groups mainly presented lumbocrural pain and lower limb radiation pain or numbness. There was no significant difference in gender, age, type, affected segment, disease duration, preoperative intervertebral height, the lordosis angle of fusion segments, and the Oswestry Disability Index (ODI) between 2 groups (P > 0.05). Lateral lumbar X-ray films and three dimensional CT were taken preoperatively and at 1 week and 3, 6, and 12 months postoperatively. The intervertebral height and the lordosis angle of fusion segments at 1 week and 3, 6, and 12 months after operation and ODI at 3, 6, and 12 months after operation were measured; and the bone graft fusion rate was evaluated according to Brantigan criteria., Results: There was no significant difference in operation time, intraoperative blood loss, and the amount of autologous blood transfusion between 2 groups (P > 0.05). Healing by first intention as obtained in 30 cses. All patients were followd up 12 months. The intervertebral height of fusion segments, the lordosis angle of fusion segments, and ODI at each time point after operation were significantly improved when compared with preoperative ones (P < 0.05). The ODI showed significant difference between 3 months and 6, 12 months (P < 0.05), but there was no significant difference between the other time points after operation (P > 0.05). There was no significant difference in the intervertebral height and the lordosis angle of fusion segments between groups at different time points (P > 0.05). There was no significant difference in the above indexes between the trial group and the control group at each time point (P > 0.05). At last follow-up, 5 cases were rated as Brantigan grade E, 13 cases as grade D, and 2 cases as grade C in the trial group; 4 cases were rated grade E, 5 cases as grade D, and 1 case as grade C in the control group. The bone fusion rate was 90% in 2 groups., Conclusion: The PHC Cage can effectively restore and maintain the disc height of fusion segment, normal sequence and biomechanical stability of the lumbar spine. The PHC Cage is similar to the PEEK Cage and has good clinical outcome in short-term follow-up.

Objective: To observe the character of spino-pelvic sagittal alignment in patients with high-grade L5 isthmic spondylolisthesis, and to analyze the sagittal alignment alteration after operation., Methods: Between January 2009 and June 2014, 25 patients with high-grade L5 isthmic spondylolisthesis underwent posterior surgery, and the clinical data were retrospectively analyzed as study group. There were 14 males and 11 females with a mean age of 42.5 years (range, 20-65 years). The mean disease duration was 6 months (range, 3-12 months). According to the Meyerding evaluating system, 15 cases were rated as degree III, and 10 cases as degree IV. Eighty healthy adult volunteers were recruited simultaneously as control group. The lumbar sacral angle (LSA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), thoracic kyphosis (TK), and sagittal vertical axis (SVA) were measured on preoperative and last follow-up standing full length lateral X-ray films. And these parameters were compared between study group (preoperative parameters) and control group. Then the patients in study group were divided into 2 subgroups according to Hresko's method: the balanced pelvis subgroup (n = 14) and unbalanced pelvis subgroup (n = 11). The sagittal parameters were compared between 2 subgroups, and the alteration of sagittal parameters before surgery and at last follow-up was analyzed in each subgroup respectively., Results: All patients in study group were followed up 18 months on average (range, 6-48 months). After surgery, spondylolisthesis was reduced from degree III to degree 0 in 12 cases and to degree I in 3 cases, and from degree IV to degree 0 in 6 cases and to degree I in 4 cases. Bone fusion was obtained in all patients at last follow-up. The preoperative PI, SS, PT, and SVA of study group were significantly greater than those of control group (P < 0.05), while the TK was significantly smaller than that of control group (P < 0.05). In the balanced pelvis subgroup, LSA, LL, and SVA at last follow-up significantly decreased while TK significantly increased when compared with preoperative ones (P < 0.05). In the unbalanced pelvis subgroup, LSA, PT, and SVA at last follow-up significantly decreased while SS, LL, and TK significantly increased when compared with preoperative ones (P < 0.05). The preoperative LSA and PT in the unbalanced pelvis subgroup were significantly greater, while SS, LL, and TK were significantly smaller than those of balanced pelvis subgroup (P < 0.05); while at last follow-up, significant differentce was found only in LSA between 2 subgroups (P < 0.05)., Conclusion: The LSA should be paid more attention in surgery to assure recovery of the sagittal balance because patients with high-grade L5 isthmic spondylolisthesis have greater PI, abnormal lumbosacral kyphosis, and sagittal imbalance.

Objective: To study the clinical characteristics of patients with alcoholic liver disease (ALD)., Methods: The records of the 302 Hospital of People's Liberation Army (Beijing, China) were searched to identify patients diagnosed with liver disease for retrospective analysis of ALD. Measurement data was summarized as mean +/- standard deviation and intergroup comparisons were made using ANOVA; count data was assessed using the chi-square test., Results: Among the total 4132 ALD cases, 97.68% were male and 2.32% were female; ages ranged from 18 to 95 years-old,with the average age being 48.11+/-10.58 years and the range of 40 to 60 years-old being the most frequently represented.Considering all patients with liver disease from 2003 to 2012,ALD cases increased over time (from 2.00% in 2003 to 5.05% in 2012). The overall ALD cases were represented by alcoholic cirrhosis (70.35%), alcoholic hepatitis (19.26%), alcoholic fatty liver (6.29%), and alcoholic liver failure (4.09%). Among the ALD patients between 40 and 60 years of age, 73.81% had cirrhosis,compared to 50.42% of ALD patients less than 40 years-old (P less than 0.001). Comparison of ALD cases in 5-year increments showed increasing trends in rates of alcoholic cirrhosis and alcoholic hepatic failure;moreover, there was an increasing annual trend in the percentage of alcoholic liver failure cases among the total cases of liver failure in our hospital., Conclusion: From 2003 to 2012,our hospital admissions increased for patients with alcoholic liver disease, and the patients were primarily in the age range of 40-60 years-old. In general, incidences of alcoholic liver failure and cirrhosis increased in recent years, and cirrhosis has been common among the elderly patients with ALD.

Objective: To observe the medium-term clinical and radiological outcomes of anterior release internal distraction in treatment of severe and rigid scoliosis., Methods: Between March 2009 and March 2012, 26 patients with severe and rigid scoliosis were treated with anterior release, posterior internal distraction, and two stage posterior spinal fusion. There were 11 males and 15 females with an average age of 19.6 years (range, 14-25 years). The average disease duration was 13.6 years (range, 3-2:4 years). All cases were idiopathic scoliosis. Of 26 cases, 2 cases were rated as Lenke type I, 8 as type II, 13 as type IV, 1 as type V, and 2 as type VI. The apical vertebrae located at T6 in 1 case, at T7 in 3 cases, at T8 in 7 cases, at T9 in 13 cases, and at T10 in 2 cases. The average 4 vertebral bodies were released by anterior approach, and average 14 vertebral bodies were fused after posterior surgery. Fourteen patients received 2 times distraction. Scoliosis Research Society-22 (SRS-22) questionnaire was used to access health-related quality of life. The radiological parameters were measured, including coronal plane Cobb angel of major curve, apical vertebral translation (AVT), C7 plumb line-center sacral vertical line (C7PL-CSVL), sagittal vertical axis (SVA), and thoracic kyphosis (TK) at pre- and post-operation. Results The average total operation time was 592.7 minutes; the average total blood loss volume was 1 311.2 mL; and total hospitalization cost was (14.7±1.4)x10(4) yuan RMB. The coronal plane Cobb angle of major curve was (55.7±16.5)°, and the TK was (43.2±16.2)° after first distraction. The patients were followed up 2-5 years (mean, 3.8 years). Temporary dyspnea and pleural effusion occurred in 1 case respectively after distraction, and symptoms disappeared after symptomatic treatment. Screw loosening and pseudoarthrosis formation was observed in 1 case at 6 months after fusion, good recovery was achieved after revision. No infection or neurological complication was found. The coronal plane Cobb angel of major curve, TK, and AVT after fusion and at last follow-up were significantly lower than preoperative ones (P<0.05), but no significant difference was found between at post-fusion and last follow-up (P>0.05). There was no significant difference in C,PL-CSVL and SVA between at pre- and post-operation (P>0.05). At last follow-up, SRS-22 questionnaire scores were 4.32±0.42 for active degree, 4.54±0.58 for mental health, 3.97±0.76 for self-image, 4.09±0.64 for pain, and 4.03±0.83 for satisfaction degree., Conclusion: Anterior release internal distraction can provide satisfactory correction results for severe and rigid scoliosis with higher safety and lower incidence of complication.

Objective: To evaluate the effect of poly-amino acid/nano-hydroxyapatite/calcium sulfate (PHC) Cage in lumbar interbody fusion of the goat., Methods: Eighteen mature female goats (weighing 29-33 kg) were divided into 3 groups randomly: PHC Cage group (group A), titanium Cage group (group B), and ilium group (group C). A left extraperitoneal approach was used to establish the animal model of discectomy and interbody fusion with Cage or ilium. The general situation was observed for 24 weeks after operation. X-ray films were taken to measure disc space height (DSH) before operation and at 4, 12, and 24 weeks after operation. CT three dimensional reconstuction was performed at 24 weeks after operation to evaluate the interbody fusion according to modified Brantigan grading. The specimens of L3,4 were harvested for mechanical test, histological, and scanning electron microscope (SEM) observation at 24 weeks after operation., Results: All goats survived to the end of experiment. DSH at 4 weeks after operation increased when compared with preoperative one in each group, and then decreased; DSH was significantly lower at 12 and 24 weeks after operation than preoperative one in group C (P < 0.05). There was no significant difference in DSH among 3 groups at preoperation and 4 weeks after operation (P > 0.05); at 12 and 24 weeks after operation, DSH of groups A and B was significantly higher than that of group C (P < 0.05), but no significant difference was found between groups A and B (P > 0.05). CT three dimensional reconstuction showed that bony fusion was obtained in all goats of groups A and C, and in 3 goats of group B; according to modified Brantigan grading, the scores of groups A and C were significantlly higher than that of group B (P < 0.05), but no significant difference between groups A and C (P > 0.05). The biomechanical test showed that there was no significant difference in range of motion between group A and group B (P > 0.05), which were significantly lower than that of group C (P < 0.05). Microscopy and SEM observations showed that the interface between the Cage and vertebral body in group A was compact without obvious gap, and most conjunctive region was filled with osseous tissue; the interface was filled with soft tissue, and the connection was slack with obvious gap in some region in group B; the interface connection was compact, most region was filled with osseous tissue in group C., Conclusion: The interbody fusion with PHC Cage is effective in goat lumbar interbody fusion model. The interface connection is compact between the Cage and the host bone followed by micro-degradation of PHC Cage, but the long-term degradation need further observation.

This study was aimed to compare the mechanical characteristics under different physiological load conditions with three-dimensional finite element model of rigid fixation and elastic fixation in the lumbar. We observed the stress distribution characteristics of a sample of healthy male volunteer modeling under vertical, flexion and extension torque situation. The outcomes showed that there existed 4-6 times pressure on the connecting rod of rigid fixation compared with the elastic fixations under different loads, and the stress peak and area of force on elastic fixation were much higher than that of the rigid fixations. The elastic fixation has more biomechanical advantages than rigid fixation in promoting interbody lumbar fusion after surgery.

Objective: To evaluate the efficacies of hematopoietic stem cell transplantation (HSCT) for severe aplastic anemia (SAA)., Methods: A total of 43 SAA patients (SAA-I, n = 29; SAA-II, n = 14) underwent HSCT from 2002 January to 2013 December. There were 22 males and 21 females with a median age of 31 (12-49) years. And 35 patients received HLA-matched sibling HSCT (Sib-HSCT) while another 8 had unrelated donor HSCT (UD-HSCT). The hematopoietic stem cells were collected from bone marrow (n = 10), peripheral blood (n = 23) and bone marrow & peripheral blood (n = 10). Conditioning regimens were mostly composed of Fludarabine, antihuman thymocyte gloBulin and cyclophosphamide. Cyclosporine and methotrexate (including mycophenolate mofetil for UD) were offered for preventing graft-versus-host disease (GVHD). The median counts of mononuclear cell and CD34(+) stem cell were 8.1 (2.4-13.5) ×10(8)/kg and 3.7 (2.3-14.7) ×10(6)/kg respectively., Results: Hematopoiesis reconstitution was achieved in 42 patients. The median periods for neutrophils to 0.5×10(9)/L and platelets to 20×10(9)/L were +10 (+8-+25) days and +14 (+8-+80) days respectively. The median of survival time was not reached. Overall survival (OS) and failure-free survival (FFS) at 5 years had no differences between UD-HSCT and Sib-HSCT groups (OS: 87.6% vs 84.5%, P = 0.87; FFS: 86.2% vs 79.5%, P = 0.64). The same results also were seen between age ≤ 20 group and > 20 group (OS: 92.0% vs 82.5%, P = 0.39; FFS: 91.0% vs 77.3%, P = 0.38). The median follow-up time was 17.0 (0.4-140.0) months. And 8/43 patients died from thrombotic microangiopathy (TMA) (n = 1), TMA associated with capillary leak syndrome (n = 1), pulmonary infection (n = 3), acute GVHD of grade IV (n = 1) and unknown causes (n = 2)., Conclusions: Sib-HSCT is preferred for SAA patients under 40 years. Searching of HLA-matched unrelated donor should be performed soon after diagnosis if HLA-matched sibling is unavailable.