Objective To explore the optimization for parameters of 5.0T pseudo continuous arterial spin labeling(pCASL)MRI of whole brain.Methods Nine healthy adults were prospectively enrolled,and single-delay pCASL scanning was performed based on a 5.0T MR scanner with 3 sets of labeling gradients:Group A,average gradient(Gavg)=1 mT/m and the ratio of maximum gradient(Gmax)to Gavg(Gratio)=10,group B,Gavg=0.6 mT/m and Gratio=10,group C,Gavg=0.3 mT/m and Gratio=9.The labeling efficiency and cerebral blood flow(CBF)of 3 groups were compared to screen the best labeling gradient group.Results When the marked average blood flow velocity was 40 cm/s,the gradient field tolerance of group C was better than that of group A and B at the situation of reduced B1+and larger B0 offset frequency range.Under the gradient field of group C,the level of labeled artery B1 ranged from 54.19％to 75.36％,with an average of 64.71％.The labeling efficiencies of group C were all ≥85％,and all ≥90％at the average B1 level(64.71％).In the whole gray matter and almost all brain regions,CBF on pCASL under gradient field of group C was significantly higher than that of group A and B(all P＜0.05).Conclusion Low Gavg and low Gmax were the optimal parameters for 5.0T whole brain pCASL MRI.

ObjectiveTo explore the possible mechanism of Tongdu Xingshen needling method （通督醒神针刺法） on post-stroke cognitive impairment. MethodsSD rats were randomly divided into a normal group （n=12）， a sham surgery group （n=12）， a model group （n=12）， and a electroacupuncture group （n=13）. The rats in the model group and electroacupuncture group were subjected to the wire bolus method to establish the rats model with learning memory impairment after cerebral ischaemia-reperfusion. After successful modelling， the rats in the electroacupuncture group were given electroacupuncture interventions at “Shenting （GV 24）” and “Baihui （GV 20）” once a day for 30 minutes for 14 days. The other three groups did not receive other interventions but grasp. A 5-day localisation navigation experiment was conducted on the 9th day of intervention， and a spatial exploration experiment was conducted on the 14th day of intervention to evaluate the learning and memory abilities of the rats. After the spatial exploration experiment， hippocampal tissues were taken from each group of rats， and the changes in the volume of cerebral infarction were observed by TTC staining； the changes in the morphology of pyramidal neurons and the density of dendritic spines in the CA1 area of the hippocampus were observed by Golgi staining； protein immunoblotting was used to detect the relative protein expression of the subunits of the α-amino-3-carboxy-5-methylisoxazole-4-propionic acid （AMPA） receptor including glutamate receptor 1 （GluR1）， glutamate receptor 2 （GluR2）， glutamate receptor 3 （GluR3） and auxiliary proteins TARPγ2， TARPγ8 in hippocampal tissues of rats in each group； the real-time fluorescence quantitative PCR was used to detect GluR1， GluR2， GluR3 mRNA levels in the hippocampal tissues of rats. ResultsIn the localisation navigation experiment， compared with the normal group and sham surgery group， the escape latency and total distance of rats in the model group were significantly extended （P＜0.05） at day 1， 2， 3， 4， and 5； and the escape latency and total distance of rats in the electroacupuncture group tended to be significantly shorter than those in the model group （P＜0.05）. In the spatial exploration experiment， compared with the normal group and the sham surgery group， the number of rats crossing the platform in the model group was significantly reduced （P＜0.05）， and the number of crossings of the platform in the electroacupuncture group increased significantly （P＜0.05）. The results of TTC staining showed that the volume of cerebral infarction increased clearly in the model group compared with the sham surgery group （P＜0.05）， and apparently decreased in the electroacupuncture group compared with the model group （P＜0.05）. Golgi staining showed that the number of dendritic branches of pyramidal neurons and dendritic spines in hippocampal CA1 region significantly decreased in the model group compared with the normal group and the sham surgery group （P＜0.05）. The number of dendritic branches of pyramidal neurons and the density of dendritic spines in hippocampal CA1 region significantly increased in the electroacupuncture group compared with the model group （P＜0.05）. The protein relative expression levels of GluR1， GluR2， GluR3， TARPγ2 and TARPγ8， and the mRNA levels of GluR1， GluR2 and GluR3 in hippocampus decreased in the model group compared with the normal group and the sham surgery group （P＜0.05）. The protein relative expression levels of GluR1， GluR2， GluR3， TARPγ2 and TARPγ8， and the mRNA levels of GluR1， GluR2 and GluR3 in hippocampus increased in the electroacupuncture group compared with model group （P＜0.05）. ConclusionThe Tongdu Xingshen needling method can improve learning memory impairment after cerebral ischaemia-reperfusion， which may be related to up-regulation of the expression of AMPA receptor and their auxiliary protein TARP， and promoting the synaptic plasticity of hippocampal tissues.

In recent decades, bone tissue engineering has made great progress in the treatment of large bone defects, among which bioprinting is one of the most important technologies. 3D bioprinting achieves precise control of the spatial structure of bone tissue engineering scaffold manufacturing by adding different materials in layers, and cells are placed into the scaffolds based on hydrogel materials to solve the uniform distribution of cells in the scaffolds. However, most biomedical materials used for 3D bioprinting are static and cannot be changed with the dynamics of the body's internal environment. 4D bioprinting combines the concept of time with 3D bioprinting and uses stimulus-responsive materials to change their shape under various stimuli to create dynamic 3D biological structures. It offers unprecedented potential for bone tissue engineering. The shape memory properties of printed structures meet the needs of personalized bone defect repair, and functional maturation procedures promote osteogenic differentiation of stem cells. In this paper, we review the commonly used 3D bioprinting methods and the mechanism of functional and morphological transformation in 3D bioprinting developed into 4D bioprinting technology by summarizing the research on bioprinting and tissue engineering at home and abroad in recent years. What's more, we introduce the application of bioprinting in the treatment of bone defects in bone tissue engineering as well as the current challenges and future prospects.

Objective:To observe the clinical efficacy of combining neuromuscular joint facilitation (NJF) with floating needle treatment in treating stroke survivors with painful shoulder subluxation.Methods:Thirty-nine stroke survivors with painful shoulder subluxation were randomly divided into an NJF group, a floating needle group and a combination group, each of 13. In addition to the basic treatment for shoulder subluxation and pain (including positioning, physiotherapy, active and passive motor function training, progressive training of the upper limbs, and using shoulder pads to protect the affected shoulders when standing or walking), the 3 groups were also given NJF, floating needle therapy or both as their group names imply six days per week for 4 weeks. Shoulder subluxation was evaluated using ultrasonography to measure the acromion-greater tuberosity distance (AGT). Pain was self-reported using a visual analogue scale. And the Fugl-Meyer assessment (FMA) was applied to quantify the treatments′ efficacy.Results:Before the treatment, no significant differences were found among the 3 groups in terms of their average AGTs, pain ratings or FMA scores. Afterward, significant improvement was observed in all of the measurements in all 3 groups, with the combination group′s average results significantly better than those of the other two. The combination group′s overall effectiveness was 85%, significantly better than that of NJF group (54%) and the floating needle group (62%).Conclusions:Floating needle treatment combined with NJF and routine rehabilitation can significantly improve motor functioning and relieve the pain of shoulder subluxation after a stroke.

This study is aimed to explore the value of high-resolution magnetic resonance （HRMRI） in the diagnosis of the etiology of stroke in young adults. Methods We retrospectively enrolled ischemic stroke or transient ischemic attack patients who ≤55 years old admitted in Peking Union Medical College Hospital from January 1，2016 to December 31，2020.Patients were separated into two groups：with or without HRMRI. After collecting the baseline data，clinical features，and imaging characteristics，we explore the differences in the clinical characteristics，the etiology of stroke，and the proportion of cryptogenic stroke between the two groups. The changes of cryptogenic stroke proportion in the HRMRI group before and after HRMRI were further calculated，and the changes of the revised diagnosis were also obtained. Results A total of 155 cases were included in the study. Of those，73 cases （47.1%） underwent HRMRI，while 82 cases （52.9%） did not. HRMRI group was slightly younger than the non-HRMRI group （40.36 VS 43.89，P=0.026），while there were no significant differences in gender，risk factors，and family history. The cryptogenic stroke proportion in the HRMRI group was lower than that in the group without HRMRI （16.4% VS 26.8%，P=0.119）.29% of patients were corrected or make more accurate the diagnosed with the help of HRMRI，reducing cryptogenic stroke by 7%. The changes in the etiology diagnosis mainly from cryptogenic stroke to atherosclerosis disease （5，5/20），and also from other vascular diseases such as arterial dissection to atherosclerosis disease （5，5/20）.Conclusion With HRMRI，nearly one-third of young stroke has revised or accurate for their diagnosis，and the remaining has confirmed for their diagnosis. This technique should be widely used in young stroke patients.

Unicompartmental knee arthroplasty(UKA) is an important surgical technique for the treatment of end-stage knee osteoarthritis, which has high requirement for the position and angle of the prosthesis. The application of three-dimensional(3D) printed in UKA reflects several characteristics such as accuracy,efficiency and safety,but the current research results show that there is still lack of consistency in the design of 3D printed guides and the standard of prosthetic position parameters. This article reviews the history, manufacturing requirements and process of 3D printed guides during UKA surgery, as well as the results of current clinical research. Whether 3D printed guides can safely and effectively improve the placement accuracy of inexperienced doctors during UKA surgery,and whether the long-term results are worthy of clinical promotion need further verification.

Unicompartmental knee arthroplasty(UKA) is an important surgical technique for the treatment of end-stage knee osteoarthritis, which has high requirement for the position and angle of the prosthesis. The application of three-dimensional(3D) printed in UKA reflects several characteristics such as accuracy,efficiency and safety,but the current research results show that there is still lack of consistency in the design of 3D printed guides and the standard of prosthetic position parameters. This article reviews the history, manufacturing requirements and process of 3D printed guides during UKA surgery, as well as the results of current clinical research. Whether 3D printed guides can safely and effectively improve the placement accuracy of inexperienced doctors during UKA surgery,and whether the long-term results are worthy of clinical promotion need further verification.

Objective:To explore the clinical predictive effect of the preoperative ratio of C reactive protein to albumin (CAR) on perioperative delirium (POD) in geriatric patients with femoral intertrochanteric fracture.Methods:The clinical data were analyzed retrospectively of the 398 patients who had undergone surgery for femoral intertrochanteric fractures at Department of Orthopedics, Xuanwu Hospital from January 2013 to March 2016. According to the presence or absence of POD, all the patients were divided into 2 groups: a delirium group and a normal group. The 2 groups were compared in terms of general clinical data like gender, age, body mass index, blood routine, CAR, biochemical indicators, blood coagulation indicators and concomitant internal diseases. After a single factor logistic regression analysis of the general clinical data of the patients, factors with P<0.10 were introduced into the multivariate logistic binary regression model to screen out the risk factors for POD in geriatric patients with femoral intertrochanteric fracture. The receiver operating characteristic (ROC) curve was drawn to analyze the predictive value and optimal cut-off point of CAR for POD in geriatric patients with femoral intertrochanteric fracture. Results:The incidence of POD in this cohort was 14.32%(57/398). The age, C-reactive protein, CAR, platelet and probability of pulmonary infection in the delirium group were significantly higher than those in the normal group, but the hemoglobin, albumin and prealbumin in the former were significantly lower than those in the latter ( P< 0.05). The multivariate logistic binary regression analysis showed that hemoglobin ( OR=0.975, 95% CI: 0.957 to 0.993, P=0.006) and CAR( OR=53.713, 95% CI: 17.713 to 162.876, P<0.001) were risk factors for POD in geriatric patients with femoral intertrochanteric fracture. The area under ROC of CAR in predicting POD in geriatric patients with femoral intertrochanteric fracture was 0.906 (95% CI: 0.873 to 0.933, P<0.001), and the cut-off point was 2.06. When CAR>2.06, its predicted incidence of POD was 50.50%, with a sensitivity of 89.47% and a specificity of 85.34%. Conclusion:As CAR is a risk factor for POD in geriatric patients with femoral intertrochanteric fracture, it can be used as an effective indicator to predict POD.

Objective:To explore the influence of lateral patellofemoral joint degeneration on the treatment of anteromedial osteoarthritis of knee joint by Oxford medial unicompartmental knee arthroplasty.Methods:The clinical data of 73 patients (73 knees) with knee osteoarthritis underwent unicompartmental knee arthroplasty at Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University from March 2016 to December 2017 were analysed respectively.There were 18 males and 55 females, aged (68.6±7.5) years(range: 53 to 89 years).The lateral patellofemoral joints of patients were evaluated by Ahlback grading system. Patients with Ahlback 0 andⅠ were in the non degenerative group (37 cases), and those with Ahlback Ⅱ and above were in the degenerative group (36 cases). Hospital for special surgery knee score(HSS) and the Western Ontario and McMaster Universities(WOMAC) osteoarthritis index, as well as the condition of kneeling, sit to stand movement, up stair and down stair were recorded. The data before and after operation were compared by paired sample t test, and the data between groups were compared by independent sample t test. χ 2 test was used for counting data. Pearson correlation analysis was used to compare the correlation between ahlback score, HSS and WOMAC osteoarthritis index. Results:The follow-up time was (35.1±6.6) months (range: 25 to 47 months).The knee function of the patients improved significantly after operation.The HSS score increased from 57.7±11.8 preoperative to 81.8±7.8 postoperative ( t=16.64, P=0.00) and WOMAC osteoarthritis index decreased from 48.9±13.4 preoperative to 15.6±8.8 postoperative ( t=20.48, P=0.00). There was no statistical difference in the change of HSS between the degenerative group and the non-degenerative group before and after surgery(27.5±12.2 vs. 22.5±12.3, t=-1.65, P=0.10) as well as the change of WOMAC osteoarthritis index(31.8±14.0 vs. 36.4±13.7, t=-1.35, P=0.18), but the lateral patellofemoral joint degeneration was related to inability to complete squats (χ 2=5.17, P=0.04) and sitting up (χ 2=7.22, P=0.01). Conclusion:The degeneration of lateral patellofemoral joint has no effect on the early functional recovery of patients with anteromedial knee osteoarthritis after Oxford medial unicompartmental knee arthroplasty.

Objective:To explore the influence of lateral patellofemoral joint degeneration on the treatment of anteromedial osteoarthritis of knee joint by Oxford medial unicompartmental knee arthroplasty.Methods:The clinical data of 73 patients (73 knees) with knee osteoarthritis underwent unicompartmental knee arthroplasty at Department of Orthopaedic Surgery, Xuanwu Hospital, Capital Medical University from March 2016 to December 2017 were analysed respectively.There were 18 males and 55 females, aged (68.6±7.5) years(range: 53 to 89 years).The lateral patellofemoral joints of patients were evaluated by Ahlback grading system. Patients with Ahlback 0 andⅠ were in the non degenerative group (37 cases), and those with Ahlback Ⅱ and above were in the degenerative group (36 cases). Hospital for special surgery knee score(HSS) and the Western Ontario and McMaster Universities(WOMAC) osteoarthritis index, as well as the condition of kneeling, sit to stand movement, up stair and down stair were recorded. The data before and after operation were compared by paired sample t test, and the data between groups were compared by independent sample t test. χ 2 test was used for counting data. Pearson correlation analysis was used to compare the correlation between ahlback score, HSS and WOMAC osteoarthritis index. Results:The follow-up time was (35.1±6.6) months (range: 25 to 47 months).The knee function of the patients improved significantly after operation.The HSS score increased from 57.7±11.8 preoperative to 81.8±7.8 postoperative ( t=16.64, P=0.00) and WOMAC osteoarthritis index decreased from 48.9±13.4 preoperative to 15.6±8.8 postoperative ( t=20.48, P=0.00). There was no statistical difference in the change of HSS between the degenerative group and the non-degenerative group before and after surgery(27.5±12.2 vs. 22.5±12.3, t=-1.65, P=0.10) as well as the change of WOMAC osteoarthritis index(31.8±14.0 vs. 36.4±13.7, t=-1.35, P=0.18), but the lateral patellofemoral joint degeneration was related to inability to complete squats (χ 2=5.17, P=0.04) and sitting up (χ 2=7.22, P=0.01). Conclusion:The degeneration of lateral patellofemoral joint has no effect on the early functional recovery of patients with anteromedial knee osteoarthritis after Oxford medial unicompartmental knee arthroplasty.