Objective To investigate the cerebral protective role of Duzhi pills on ischemic stroke rats and its mechanisms.Methods The healthy male SD rats were assigned to 5 groups:sham group,model group,Duzhi pill low-dose group(1.0 g/kg a day),Duzhi pill high-dose group(2.0 g/kg a day),or argatroban group(positive control).The low-dose and high-dose groups of Duzhi pills were intragastrically administered once a day for 8 d,while the other groups were intragastrically administered with the same amount of normal saline.Except the sham group,the middle cerebral artery occlusion(MCAO)cerebral ischemia-reperfusion model was established by suture method at 0.5 h after intragastric administration on the 8th day in other groups,and the ischemia duration was 90 min.Argatroban group was given a single dose(3.0 mg/kg)of argatroban via caudal vein at the same time of reperfusion.After 24 h of cerebral ischemia,the area of cerebral infarction,degree of cerebral infarction and neurological function injury were evaluated by 2,3,5-triphenyltetrazolium chloride(TTC)staining,Nissl staining and neurobehavioral score,respectively.The levels of inflammatory factors(transforming growth factor-β1[TGF-β1]and interleukin-1β[IL-1β])in the brain after cerebral ischemia were detected by enzyme-linked immunosorbent assay(ELISA),and the coagulation indexes were detected by an automatic coagulation analyzer.The scavenging ability of Duzhi pills on free radicals was analyzed by 2,2-diphenyl-1-picrylhydrazyl(DPPH)scavenging experiment.Results High-dose Duzhi pills reduced the cerebral infarction area,decreased the deep Nissl staining score of neural cells,and improved the symptoms of neurobehavioral defects in MCAO rats(compared with the model group,all P＜0.01).The levels of IL-1β and TGF-β1 in the ischemic brain tissue of the model group were significantly increased(compared with the sham group,both P＜0.01),while the levels of IL-1β and TGF-β1 in the brain tissue of the rats treated with low-dose and high-dose Duzhi pills were significantly decreased(compared with the model group,all P＜0.01).The coagulation index fibrinogen level in the model group was significantly higher than that in the sham group(P＜0.01),and both low-dose and high-dose Duzhi pills could inhibit the production of fibrinogen(compared with the model group,both P＜0.01).DPPH scavenging test results showed that Duzhi pills could scavenge free radical,the half inhibitory concentration was(1.33±1.11)mg/mL,and the slope of the curve was 1.378±0.145.Conclusion Duzhi pills play a cerebral protective role in ischemic stroke rats.The mechanism may be related to the inhibition of fibrinogen production,the reduction of inflammatory factors(TGF-β1 and IL-1β),and the antioxidant effects.

Objective To explore the biomechanical safety of applying traditional Chinese orthopedic manipulation therapy after anterior cervical discectomy and fusion(ACDF)surgery,so as to provide a theoretical basis for clinical treatment in biomechanics.Methods Based on CT data,a three-dimensional finite element model of the normal C0-T1 cervical spine was established,and an ACDF postoperative finite element model of the C5-6 segment was constructed on this basis.Cervical spine rotation manipulation was simulated at the C4 and C7 segments of both models,and the von Mises stresses of the vertebral body,bilateral facet joints,intervertebral discs,and internal fixation system under manipulation loading of the C4 and C7 segments in both models were compared and analyzed.Results When the C4 segment was manipulated,the stress on the C5,C6,and C7 vertebral bodies in the ACDF postoperative model decreased by 12.3％,11.5％,and 26.4％,compared to the normal model.The stress on the left facet joints of the C4-5,C5-6,and C6-7 segments decreased by 12.3％,58.8％,and 15.4％,and the stress on the right facet joints decreased by 16.6％,92.1％,and 17.2％.The stress on the C4-5 and C6-7 segments decreased by 13.2％and 4.0％,while the maximum stress of the fusion cage,titanium plate,and screws in the C5-6 segment were 9.349,111.9,and 300.8 MPa.When the C7 segment was manipulated,the stress on the C4,C5,and C6 vertebral bodies in the ACDF postoperative model increased significantly compared to the normal model,especially the C5 vertebral body,with an increase of nearly 18 times.Except for the stress on the left facet joint of the C4-5 segment increased by 57.7％,the stress on the bilateral facet joints of other segments generally decreased,but the stress on the C4-5 and C6-7 segments increased by 43.2％and 21.7％and the stresses on the fusion cage,titanium plate,and screws in the C5-6 segment were 2.926,205.4,and 256.2 MPa.Conclusions The safety of performing manipulation on the upper vertebral body of the fusion segment after ACDF surgery is relatively high,but performing manipulation on the lower vertebral body of the fusion segment may lead to stress concentration and increase the risk of injury.When postoperative conservative treatment is implemented,the manipulation safety and indications should be considered to avoid operations in high-risk areas,and more precise and safe manipulation intervention treatment should be implemented based on the specific postoperative biomechanical state of the patient.

Objective To explore the biomechanical characteristics of different types of lumbar disc herniation(LDH),and provide a theoretical basis for the clinical classification,diagnosis,and treatment of LDH.Methods A normal lumbar spine model with spinal nerves and four types of LDH models(central type,paracentral type/lateral recess type,intervertebral foramen type,extreme type)were constructed,and the biomechanical characteristics of the intervertebral discs and nerve roots in neutral posture and under six degrees of freedom conditions were analyzed.Results In neutral position,the stress of normal intervertebral disc was carger than that of the herniated intervertebral disc,and the stress ratio of annulus fibrosus and nucleus pulposus in normal model was greater than that of annulus fibrosus and nucleus pulposus in herniated models.In neutral position,the disc stress was mainly concentrated at the incisor between the protrusion and normal part,and recruitment occurred at outer edge of the disc.In flexion and extension position,the stress of the herniated intervertebral disc shifted to the right side.The maximum stress of herniated intervertebral disc appeared during right flexion,and the nerve root stress on the right side was carger than that on the left side.The stress of the herniated intervertebral disc during right rotation was slightly lower than that during right flexion,and the stress of nerve root on the right side was smaller than that on the left side.Conclusions The intervertebral disc is important in maintaining lumbar dynamic and static stability and flexibility.Different positions have an obvious effect the intervertebral disc stress.For patients with LDH,forward bending,flexion of the affected side and large extension should be avoided.Appropriate rotation of the affected side can help relieve the symptoms of nerve root compression.

Objective To explore the biomechanical safety of applying traditional Chinese orthopedic manipulation therapy after anterior cervical discectomy and fusion(ACDF)surgery,so as to provide a theoretical basis for clinical treatment in biomechanics.Methods Based on CT data,a three-dimensional finite element model of the normal C0-T1 cervical spine was established,and an ACDF postoperative finite element model of the C5-6 segment was constructed on this basis.Cervical spine rotation manipulation was simulated at the C4 and C7 segments of both models,and the von Mises stresses of the vertebral body,bilateral facet joints,intervertebral discs,and internal fixation system under manipulation loading of the C4 and C7 segments in both models were compared and analyzed.Results When the C4 segment was manipulated,the stress on the C5,C6,and C7 vertebral bodies in the ACDF postoperative model decreased by 12.3％,11.5％,and 26.4％,compared to the normal model.The stress on the left facet joints of the C4-5,C5-6,and C6-7 segments decreased by 12.3％,58.8％,and 15.4％,and the stress on the right facet joints decreased by 16.6％,92.1％,and 17.2％.The stress on the C4-5 and C6-7 segments decreased by 13.2％and 4.0％,while the maximum stress of the fusion cage,titanium plate,and screws in the C5-6 segment were 9.349,111.9,and 300.8 MPa.When the C7 segment was manipulated,the stress on the C4,C5,and C6 vertebral bodies in the ACDF postoperative model increased significantly compared to the normal model,especially the C5 vertebral body,with an increase of nearly 18 times.Except for the stress on the left facet joint of the C4-5 segment increased by 57.7％,the stress on the bilateral facet joints of other segments generally decreased,but the stress on the C4-5 and C6-7 segments increased by 43.2％and 21.7％and the stresses on the fusion cage,titanium plate,and screws in the C5-6 segment were 2.926,205.4,and 256.2 MPa.Conclusions The safety of performing manipulation on the upper vertebral body of the fusion segment after ACDF surgery is relatively high,but performing manipulation on the lower vertebral body of the fusion segment may lead to stress concentration and increase the risk of injury.When postoperative conservative treatment is implemented,the manipulation safety and indications should be considered to avoid operations in high-risk areas,and more precise and safe manipulation intervention treatment should be implemented based on the specific postoperative biomechanical state of the patient.

Objective To explore the biomechanical characteristics of different types of lumbar disc herniation(LDH),and provide a theoretical basis for the clinical classification,diagnosis,and treatment of LDH.Methods A normal lumbar spine model with spinal nerves and four types of LDH models(central type,paracentral type/lateral recess type,intervertebral foramen type,extreme type)were constructed,and the biomechanical characteristics of the intervertebral discs and nerve roots in neutral posture and under six degrees of freedom conditions were analyzed.Results In neutral position,the stress of normal intervertebral disc was carger than that of the herniated intervertebral disc,and the stress ratio of annulus fibrosus and nucleus pulposus in normal model was greater than that of annulus fibrosus and nucleus pulposus in herniated models.In neutral position,the disc stress was mainly concentrated at the incisor between the protrusion and normal part,and recruitment occurred at outer edge of the disc.In flexion and extension position,the stress of the herniated intervertebral disc shifted to the right side.The maximum stress of herniated intervertebral disc appeared during right flexion,and the nerve root stress on the right side was carger than that on the left side.The stress of the herniated intervertebral disc during right rotation was slightly lower than that during right flexion,and the stress of nerve root on the right side was smaller than that on the left side.Conclusions The intervertebral disc is important in maintaining lumbar dynamic and static stability and flexibility.Different positions have an obvious effect the intervertebral disc stress.For patients with LDH,forward bending,flexion of the affected side and large extension should be avoided.Appropriate rotation of the affected side can help relieve the symptoms of nerve root compression.

Objective:To explore the relationship between school bullying and mental sub-health in middle school students and the potential moderating role of resilience in this relationship.Methods:Totally 792 students aged 10 to 14 years from two middle schools in Wuhan were selected.The Chinese version of Olweus Bully/Victim Questionnaire,Multidimensional Sub-health Questionnaire of Adolescents,and Adolescent Psychological Resilience Scale were used to measure school bullying,mental sub-health,and psychological resilience of students,respectively.Results:Being bullied scores were positively associated with mental sub-health scores(β=1.88).The moderating effect of psychological resilience scores between being the scores of bullied and mental sub-health was statistically significant(β=-0.07).Conclusion:The experience of bullying may be associated with mental sub-health problems of middle school students,and psychological resilience may play a moderating role in the relation-ship between being bullied and mental sub-health.

Objective To simultaneously collect and analyze the kinematic and dynamic parameters for two techniques of traditional Chinese cervical manipulation ( TCCM), and quantitatively describe its biomechanical characteristics. Methods A senior practitioner completed the TCCM (positioning and directional rotation pulling, lateral flexion, respectively) on 10 healthy subjects, and the fluorescent marker balls were pasted on the operator to capture manipulation movements. The dynamic parameters and the surface electromyography ( sEMG) signals were collected by pressure-sensitive gloves and wireless sEMG acquisition system. Results The upper arm muscle was the main force muscle during TCCM, and biceps brachii had the highest contribution rate. The range of motion (ROM), speed, pulling force, and time during cervical spine positioning and directional rotation pulling were all greater than those during cervical spine lateral flexion. The integrate electromyography ( iEMG) and root mean square (RMS) for each muscle of the operator during cervical spine positioning and directional rotation pulling were higher than those during cervical spine lateral flexion. Conclusions The overall ROM, three-dimensional (3D) motion angle, load intensity and time during CCTM have the characteristics of high speed, low amplitude and strong force, reflecting the biomechanical characteristics of ‘ cunjin ’ ( one-inch punch ) in traditional Chinese medicine. This study provides references for further standardizing manual teaching and training and improving clinical safety.

Background:Understanding and minimizing existing global coronavirus disease 2019(COVID-19)vaccination disparities is critical to global population health and eliminating health inequities.The study aims to investigate the disparities of vaccination coverage and progression and the associated economic and educational determinants to inform global COVID-19 vaccination strategies.Methods:COVID-19 vaccination coverage data from 206 countries used in the study were derived from"Our World in Data"website.After obtaining the vaccination coverage indicators,we fitted the progression indicators for vaccination.Correlation and multiple linear regression analysis were used to examine the effects of gross domestic product(GDP)per capita,Gini index,education,and their interactions on the coverage and progression of the COVID-19 vaccination.Results:The coverage of COVID-19 vaccination ranged from less than 30 doses to more than 150 doses per hun-dred people,from less than 15％to more than 75％for proportion of people vaccinated,from less than 15％to more than 60％for proportion of people fully vaccinated.Similarly,the progression of vaccination ranged from less than 0.1 to more than 0.6 for progression of total number of doses,from less than 0.1 to more than 0.3 for progression of proportion of people vaccinated,and from less than 0.1 to more than 0.4 for progression of propor-tion of people fully vaccinated.GDP per capita and education were positively associated with the coverage and progression,while Gini index was negatively associated with the coverage and progression.Negative interaction between GDP per capita and education was also observed for coverage(β=-0.012 to-0.011,P＜0.05)and progression(β=-0.012 to-0.011,P＜0.05).Conclusions:Substantial geographic disparities existed for the coverage and progression of COVID-19 vaccination.Economy and education are two important factors contributing to the disparities.Different countries may adopt varied strategies to promote the national distribution and vaccination of COVID-19 vaccines.

A comprehensive, geometrically accurate, nonlinear C0-T1 three-dimensional finite element (FE) model was developed for the biomechanical study of human cervical spine and related disorders. The model was developed with anatomic detail from the computed tomography (CT) images of a 46-year-old female healthy volunteer, and applied the finite element model processing softwares such as MIMICS13.1, Hypermesh11.0, Abaqus 6.12-1, etc., for developing, preprocessing, calculating and analysing sequentially. The stress concentration region and the range of motion (ROM) of each vertebral level under axial rotation, flexion, extension, and lateral bending under physiologic static loadings were observed and recorded. The model was proven reliable, which was validated with the range of motion in previous published literatures. The model predicted the front and side parts of the foramen magnum and contralateral pedicle and facet was the stress concentration region under physiological loads of the upper spine and the lower spine, respectively. The development of this comprehensive, geometrically accurate, nonlinear cervical spine FE model could provide an ideal platform for theoretical biomechanical study of human cervical spine and related disorders.
Biomechanical Phenomena ; Cervical Vertebrae ; Female ; Finite Element Analysis ; Humans ; Middle Aged ; Models, Biological ; Range of Motion, Articular ; Rotation

Clinical advantages of Chinese spinal manipulation therapy (CSMT) were recognized for spinal chronic lesions of soft tissues and bones, such as cervical spondylosis, etc. However, the security of CSMT and the hypotheses of practice mechanisms were questioned for lacking of the relevant basic researches. Researches have proved that these methods could be used to observe the dynamic effects of spine with application of finite element analysis (FEA) computer technology. Combining with other biomechanical experimental methods and applying advanced FEA technology for mechanical problems of CSMT, we may not only find the mechanisms of action and provide theoretical supports for the traditional Chinese therapy, but also standardize the key techniques and optimize the treatment options improving clinical outcomes, and even promote spreading of CSMT. Computer models are ideally suited for studying phenomena that cannot be satisfactorily investigated with other models. However, computer models of CSMT practice remain to be further refined. The results which had been acquired so far not only verified some of the traditional points of view, but also revised and specified some perspectives of the past. This paper intends to review FEA studies with Chinese cervical manipulation therapy (CCMT) for cervical spinal chronic lesions of soft tissues and bones, involving different effects for cervical spine joints (pulling/traction and thrusting) with practice techniques and cervical spine soft tissues (including vessels and its hemodynamics, muscles and fasciae, etc).
Biomechanical Phenomena ; Cervical Vertebrae ; anatomy & histology ; physiopathology ; Finite Element Analysis ; Humans ; Manipulation, Spinal ; methods ; Spondylosis ; physiopathology ; therapy