By establishing a series of Dynamic Cervical Implants (DCI) within C5-C6 cervical spinal segments, the biomechanical finite element analysis for DCI with different width and thickness were carried out to investigate the influence of the width and thickness of DCI's curved section on its equivalent stress and range of motion (ROM), so as to provide some theoretical basis for the optimization of DCI's design. The results show that the width of DCI's curved section has more obvious influence on the ROM of lateral bending and torsion, in comparison with the thickness of DCI's curved section. By appropriate reduction in width, the ROMs of lateral bending and torsion increase obviously, i.e. the overall movement function of patients is improved. Furthermore, the increase of equivalent stress could be counteracted by corresponding increase of thickness.
Biomechanical Phenomena ; Cervical Vertebrae ; Finite Element Analysis ; Humans ; Movement ; Neck ; Prostheses and Implants ; Prosthesis Design ; Range of Motion, Articular

Two p-phenylenediamine (p-PD)-imprinted polymers, P (MAA) and P (AA), were synthesized using methacrylic acid (MAA) and acrylamide(AA) as functional monomer, respectively, in order to prepare molecular recognition material with high selectivity for p-PD and explore the feasibility of methods such as molecular spectrometry and computational approach of quantum chemistry for the selection of functional mono mer with high imprinting efficiency.The molecular recognition properties of the imprinted polymers were evaluated by high performance liquid chromatography.The results indicated that P(AA) exhibited no imprint ing effect for p-PD, while P(MAA) can bind p-PD selectively(k' =3.57), which showed remarkable imprint ing effect (IF=2.95), and p-PD and its analogues o-phenylenediamine and p-aminobenzoic acid can almost realize baseline separation on P (MAA) column in the mobile phase of methanol.Furthermore, we made a comparative study on the interaction of p-PD with MAA and AA by spectroscopic techniques such as UV and fluorometry as well as HF/6-31G~* computational approach.The results demonstrated that the complex of p-PD-MAA was more stable than that of p-PD-AA, which can give a good explanation for the molecular recog nition properties of P (MAA) and P (AA).The study indicated that both molecular spectrometry (UV and fluorometry)and computational approach of quantum chemistry can be employed as efficient means for the selection of efficient functional monomer.The results showed that fluorometry is sensitive and convenient for the choice of functional monomer if the template molecule is fluorescent.

Objective To investigate the effect of cystatin C (Cys C) on adventitia in rabbit abdominal aorta restenosis after angioplasty and its mechanism.Methods 48 New Zealand white rabbits were randomly divided into injury group (receiving balloon dilation of abdominal aorta),the treatment group (taking Cys C monoclonal antibody therapy) and the control group (receiving femoral artery puncture and catheter sheath without balloon dilation and intervention of Cys C monoclonal antibody injection),and each group had 16 rabbits.Peripheral vein blood was drawn to measure the serum level of cystatin C before and 8 h,1 day,1 week,3 weeks,6 weeks after the operation in all rabbits.After 6 weeks of operation,the abdominal aorta were taken and stained with HE.Vascular morphometry analysis and adventitial cell count were conducted.Smooth muscle actin (SM-actin) and proliferating cell nuclear antigen (PCNA) expressions in the adventitia were observed by immunohistochemical staining.The number of PCNA positive cell in the adventitia was counted and the PCNA proliferation index was calculated.The vascular remodeling index,vascular external elastic lamina area (EELA),internal elastic lamina area (IEIA) were used to evaluate the vascular remodeling and the residual stenosis and vascular cavity area was used to measure the vascular stenosis.Results Plasma Cys C level began to rise at 8h after operation and reached the peak at 1 week after operation,and continuously increased for 5 weeks in injury group,and reached to respectively at 3 weeks and 6 weeks after operation.The Cys C levels were significantly higher in injury group than in the treatment and control groups at different time points (all P＜0.05).There were no significant differences in Cys C levels at different time points between the treatment group and the control group.The injury group showed that the number of PCNA positive cells was higher in injury group than in treatment and control groups,both P＜0.05).Compared with the control group,the vascular luminal area,EELA and IELA were significantly increased (all P＜0.05).After treated with the monoclonal antibody Cys C intervention,the treatment group showed that lumen area,vascular EELA,IELA was significantly decreased (P＜0.05),and the vascular remodeling index and residual stenosis rate were decreased as compared with the injury group (0.871 vs.0.784,33.1％ vs.19.7 ％,both P＜0.05).Correlation analysis showed that Cystatin C level was positively correlated with the vascular lumen area,neointimal area,internal elastic lamina area,external elastic lamina area and the number of PCNA positive cells (r=0.812,0.797,0.876,0.932 and 0.822 respectively,all P＜0.01).Conclusions Plasma Cys C level is increased in rabbit after abdominal aorta balloon injury and has a positive correlation with the severity of arterial stenosis.High Cys C level can induce adventitial fibroblast activation,proliferation,phenotype transformation and migration,and accelerate the processes of atherosclerosis and stenosis.Cys C level is the independent risk factor for abdominal aortic stenosis.

Inner ear is one of the most sensitive parts to microwave radiation.The effect of microwave radiation on the inner ear system is its damage to the vestibule and cochlea.The vestibular and cochlear injury is closely related to the balance of the human body and hearing loss.This article reviews the mechanism of microwave and effects of microwave radiation on the structure and function of the inner ear in order to provide data for future related research.

Objective To investigate the urinary iodine level and thyroid function during different trimesters of pregnancy in Hangzhou residents and to provide evidence for monitoring iodine nutrition or screening thyroid function. Methods The urinary iodine level and thyroid function of 395 subjects from 5 hospitals in Hanzhou were investigated. The urinary iodine level was measured by arsenic-cerium contact process method. The serum TSH, FT3 and FT4 were measured by chemiluminescence method. Results (1) The urinary iodine median concentration during pregnancy in the 1st, 2nd and 3rd trimesters were 170.3, 170.2, 162.4 μ/L respectively, all significantly lower than that of non-pregnant women (251.9 μg/L, all P < 0.05); (2) The mean value of TSH during the 1st trimester of pregnancy was significantly lower than that of non-preguant women (P < 0.05). The mean values of FT4 and FT3 in the 2nd and the 3rd trimesters of pregnancy were significantly lower than those of the control (P < 0.05); (3) During 2nd trimester, there were 8.7% (9/104, in FT4) and 9.6% (10/104, in FT3) pregnant women below normal lower range while during 3rd trimester, these figures reached 22.7% (22/97) and 17.5% (17/97) resfectively. Conclusions More than half of the pregnant women in Hangzhou have good nutritional status of iodine. There are significant differences in thyroid hormone levels between the non-pregnant and pregnant women as well as between gestation periods. Therefore, it is necessary to establish a trimester-specific reference range of thyroid hormones for normal pregnancy. The screening for thyroid function is recommended for pregnant women besides monitoring routine urinary iodine.

Objective To assess the clinical value of endoscopic ultrasonography ( EUS ) for predicting esophageal varices ( EV ) progression in patients with hepatitis B virus ( HBV )-related hepatocirrhosis. Methods A retrospective cohort study was performed on 299 HBV-related hepatocirrhosis patients with light EV in Tianjin Second People′s Hospital admitted from September 2014 to September 2015. The diameter and number of peri-esophageal collateral veins ( ECV ) and para-ECV were measured and described by EUS. The first EUS examination time was the starting point, and the follow-up of 24 months or EV progression was the end. Risk factors of EV progression were evaluated by multivariate Cox regression model, and the predictive value of EUS for EV progression was analyzed by receiver operating characteristic ( ROC) curve. Results The cumulative incidence of EV progression was 2. 3％ ( 7/299 ) , 14. 8％( 44/297) , 33. 7％ ( 96/285) and 40. 0％ ( 120/273) at 6 months, 12 months, 18 months and 24 months of follow-up, respectively. The results of multivariate Cox regression analysis showed that the diameter of peri-ECV ( P=0. 0112, HR=1. 3232, 95％CI: 1. 0656-1. 6429 ) , the number of peri-ECV ( P=0. 0001, HR=1. 3666, 95％CI:1. 1634-1. 6052) and para-ECV diameter ( P=0. 0002, HR=1. 3641, 95％CI:1. 1558-1. 6100) were risk factors for EV progression. The use of nucleoside analogues treating HBV (P=0. 0020, HR=0. 4969, 95％CI: 0. 3186-0. 7751) and non-selective β-blockers descending portal venous pressure ( P=0. 0765, HR=0. 5732, 95％CI:0. 3097-1. 0611) were the protective factors for EV progression. The results of ROC curve analysis showed that the diameter of peri-ECV[ P<0. 001, area under the curve (AUC)= 0. 850, 95％CI: 0. 804-0. 895], the number of peri-ECV (P<0. 001, AUC=0. 831, 95％CI: 0. 784-0. 878), the diameter of para-ECV (P<0. 001, AUC=0. 924, 95％CI: 0. 895-0. 954) , and the number of para-ECV ( P<0. 001, AUC=0. 761, 95％CI: 0. 704-0. 817 ) had higher predictive value for EV progression;and the optimum cut-off values of each index were 1. 85 mm, 3. 5, 3. 35 mm, and 4. 5, respectively. The accuracies of prediction for EV progression were 76. 60％, 75. 19％, 84. 48％ and 70. 29％, respectively. Conclusion EUS can be used to predict EV progression in HBV-related hepatocirrhosis patients. Peri-ECV diameter>1. 85 mm, number>3. 5, and para-ECV diameter>3. 35 mm, number>4. 5 suggest a high risk of EV progression. For patients with HBV-related hepatocirrhosis complicated with mild EV, nucleoside analogues to anti-HBV and non-selective β-blockers to reduce portal hypertension can prevent EV progression.

Objective To assess the predictive value of endoscopic ultrasonography(EUS)for esophageal varices(EV)bleeding by studying the relationship between esophageal collateral veins(ECV), portal vein(PV)trunk with its main branches and EV bleeding. Methods A retrospective cohort study of 114 cases of moderate and severe EV was conducted. The ECV level was determined through EUS. At the same time,diameters of PV,azygos vein(AIV)and spleen vein(SV)were measured through EUS. The predictive value of ECV level and diameters of PV, AIV, SV for EV bleeding were assessed during the 1-year follow-up, which started from the first EUS examination to EV bleeding or the end of follow-up. Results Single factor Cox regression analysis showed severe peri-ECV varices had higher risk than mild in EV bleeding(HR=4.081,95%CI:1.833-9.086,P=0.001); severe para-ECV varices had higher risk than mild in EV bleeding(HR= 4.042, 95%CI:1.814-9.005,P= 0.001). Multivariable Cox retrospective analysis showed ECV level was an effective predictor for EV bleeding, when the peri-ECV and para-ECV were severe varices, EV bleeding risk increased to 3.831 3(P=0.004 3)and 3.493 3(P=0.003 1) times compared with mild respectively. Diameters of PV,AIV and SV could predict EV bleeding(PV AUC=0.959,P<0.001;AIV AUC=0.958,P<0.001;SV AUC=0.830,P<0.001).In addition, when diameter of PV>13.65 mm(sensitivity=0.94, specificity=0.84), AIV>8.65 mm(sensitivity=0.94, specificity=0.89),SV>9.45 mm(sensitivity=0.90, specificity=0.67), EV bleeding risk increased significantly. Conclusion EUS is helpful to predict the risk of moderate and severe EV bleeding, and severe varices of ECV,PV,AIV,and SV can be used as indicators to predict risk of EV bleeding.

Objective To evaluate the value of perfusion imaging mismatch and low perfusion ratio(HIR)based on CT perfusion imaging in predicting acute intracranial large vessel occlusion(LVO)associated with intracranial atherosclerotic stenosis(ICAS).Methods A total of 82 pa-tients with acute intracranial LVO who underwent emergency thrombectomy in our hospital from February 2019 to December 2020 were enrolled in this study.According to the etiology,they were divided into ICAS-related LVO group(ICAS-LVO,65 cases)and cardiogenic embolism group(17 cases).ROC curve was plotted to analyze the predictive value of CT perfusion imaging parame-ters.Results Compared with the cardiogenic embolism group,the ICAS-LVO group had signifi-cantly larger male ratio,higher BMI and TG level,more severe progression of disease,longer time from onset to surgery,larger proportion of ischemic penumbra and higher mismatch ratio,and ob-viously less ratio of atrial fibrillation,lower BNP and HDL levels,smaller infarct volume,and lower HIR(P＜0.05,P＜0.01).ROC curve analysis showed that HIR and mismatch ratio had good predictive value for the etiology of ICAS-LVO.The optimal cut-off value of HIR was 0.26,with an AUC value of 0.74,a specificity of 0.88,and a sensitivity of 0.54.The optimal cutoff for the mismatch ratio was 3.84,with an AUC value of 0.84,a specificity of 0.75,and a sensitivity of 0.90.Generalized linear model revealed that HIR and cerebral blood volume index had no signifi-cant difference in prognostic performance(P=0.175).Conclusion HIR and mismatch ratio are helpful to identify the pathogenesis earlier and formulate surgical strategies more accurately,thereby reducing iatrogenic injury to a greater extent,increasing the effective reperfusion rate,re-ducing the disability and mortality,and improving the prognosis of clinical outcomes.

The Coronaviridae family is characterized by a nucleocapsid that is composed of the genome RNA molecule in combination with the nucleoprotein (N protein) within a virion. The most striking physiochemical feature of the N protein of SARS-CoV is that it is a typical basic protein with a high predicted pI and high hydrophilicity, which is consistent with its function of binding to the ribophosphate backbone of the RNA molecule. The predicted high extent of phosphorylation of the N protein on multiple candidate phosphorylation sites demonstrates that it would be related to important functions, such as RNA-binding and localization to the nucleolus of host cells. Subsequent study shows that there is an SR-rich region in the N protein and this region might be involved in the protein-protein interaction. The abundant antigenic sites predicted in the N protein, as well as experimental evidence with synthesized polypeptides, indicate that the N protein is one of the major antigens of the SARS-CoV. Compared with other viral structural proteins, the low variation rate of the N protein with regards to its size suggests its importance to the survival of the virus.
Amino Acid Motifs ; genetics ; Amino Acid Sequence ; Antigens, Viral ; immunology ; Base Composition ; Base Sequence ; Cluster Analysis ; Computational Biology ; DNA Primers ; Enzyme-Linked Immunosorbent Assay ; Genetic Variation ; Molecular Sequence Data ; Nucleocapsid Proteins ; genetics ; immunology ; metabolism ; Phosphorylation ; SARS Virus ; genetics ; Sequence Analysis, DNA

The R (replicase) protein is the uniquely defined non-structural protein (NSP) responsible for RNA replication, mutation rate or fidelity, regulation of transcription in coronaviruses and many other ssRNA viruses. Based on our complete genome sequences of four isolates (BJ01-BJ04) of SARS-CoV from Beijing, China, we analyzed the structure and predicted functions of the R protein in comparison with 13 other isolates of SARS-CoV and 6 other coronaviruses. The entire ORF (open-reading frame) encodes for two major enzyme activities, RNA-dependent RNA polymerase (RdRp) and proteinase activities. The R polyprotein undergoes a complex proteolytic process to produce 15 function-related peptides. A hydrophobic domain (HOD) and a hydrophilic domain (HID) are newly identified within NSP1. The substitution rate of the R protein is close to the average of the SARS-CoV genome. The functional domains in all NSPs of the R protein give different phylogenetic results that suggest their different mutation rate under selective pressure. Eleven highly conserved regions in RdRp and twelve cleavage sites by 3CLP (chymotrypsin-like protein) have been identified as potential drug targets. Findings suggest that it is possible to obtain information about the phylogeny of SARS-CoV, as well as potential tools for drug design, genotyping and diagnostics of SARS.
Amino Acid Sequence ; Base Composition ; Base Sequence ; Cluster Analysis ; Computational Biology ; Conserved Sequence ; genetics ; Evolution, Molecular ; Gene Components ; Genome, Viral ; Molecular Sequence Data ; Mutation ; genetics ; Phylogeny ; Protein Structure, Tertiary ; RNA Replicase ; genetics ; SARS Virus ; genetics ; Sequence Analysis, DNA