Objective To investigate the effects of transcranial direct current stimulation(tDCS)combined with resistance training on the performance of college students completing pull-ups,and explore the potential mechanisms underlying the effects of training intervention from the perspective of neuromuscular activity control.Methods A total of 25 male college student volunteers were randomly divided into the tDCS combined with resistance training group(experiment group)and resistance training group(control group).Twelve subjects in the control group received a lat pull-down strength training intervention lasting for 8 weeks,with 4 sets of 12 movement repetitions each,3 times per week.Thirteen subjects in the experimental group received a 20-minute tDCS before the lat pull-up resistance training intervention.Lat pull-down isometric maximal voluntary contraction(MVC)force,lat pull-down maximal repetitions under 80％one-repetition maximum(1RM)loading,and conventional pull-up exercise were tested before and after the training intervention.Surface electromyography(sEMG)signals of the main exertion muscles of the upper limb were recorded during the pull-up exercise test.Results After the training intervention,the number of pull-ups completed by the experimental group and control group increased by 1.74 times and 1.42 times,respectively.Subjects in both groups showed significant improvements in their MVC and lat pull-down maximal repetitions under 80％1RM loading.However,there were no statistical differences in these indicators between groups.Activation levels of the agonist muscles brachioradialis,posterior deltoid,and pectoralis major were significantly decreased after the training compared to those before training for both groups.In addition,the coactivation level of the antagonist triceps brachii muscle in the experimental group significantly decreased from 0.50±0.22 to 0.37±0.09 after the training,while there was no significant change in the control group before and after the intervention.Conclusions Eight-week tDCS combined with resistance training and resistance training alone can significantly improve the pull-up performance of college students,which may be related to the fact that both types of training can significantly improve the active muscle contraction capacity.Combined with resistance training,tDCS is more effective in decreasing the coactivation level of triceps brachii during pull-ups and increasing the contraction efficiency of elbow joint muscles.

There exist risks of ionizing radiation in radiodiagnosis examinations. Implementing shielding protection following the optimization and as low as reasonably achievable (ALARA) principles represents a measure to reduce radiation doses to patients. The implementation of shielding protection in clinical practices should meet high requirements due to variations in the modalities and items in radiodiagnosis examinations, the characteristics and irradiation method of X-ray beams, the method of automatic selection of image quality and radiation dose-related parameters by imaging equipment, the radiation sensitivity of human tissues and organs. This review introduced the shielding products, methods and effects in various radiodiagnosis examinations, as well as the current status and challenges in their applications, aiming to provide a reference for future related research and clinical practices.

Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80％)had normal cognition,85(6.47％)had suspected cognitive impairment,and 49(3.73％)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P＜0.05)and normal cognitive group(P＜0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P＜0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.

There exist risks of ionizing radiation in radiodiagnosis examinations. Implementing shielding protection following the optimization and as low as reasonably achievable (ALARA) principles represents a measure to reduce radiation doses to patients. The implementation of shielding protection in clinical practices should meet high requirements due to variations in the modalities and items in radiodiagnosis examinations, the characteristics and irradiation method of X-ray beams, the method of automatic selection of image quality and radiation dose-related parameters by imaging equipment, the radiation sensitivity of human tissues and organs. This review introduced the shielding products, methods and effects in various radiodiagnosis examinations, as well as the current status and challenges in their applications, aiming to provide a reference for future related research and clinical practices.

Objective To investigate the effects of transcranial direct current stimulation(tDCS)combined with resistance training on the performance of college students completing pull-ups,and explore the potential mechanisms underlying the effects of training intervention from the perspective of neuromuscular activity control.Methods A total of 25 male college student volunteers were randomly divided into the tDCS combined with resistance training group(experiment group)and resistance training group(control group).Twelve subjects in the control group received a lat pull-down strength training intervention lasting for 8 weeks,with 4 sets of 12 movement repetitions each,3 times per week.Thirteen subjects in the experimental group received a 20-minute tDCS before the lat pull-up resistance training intervention.Lat pull-down isometric maximal voluntary contraction(MVC)force,lat pull-down maximal repetitions under 80％one-repetition maximum(1RM)loading,and conventional pull-up exercise were tested before and after the training intervention.Surface electromyography(sEMG)signals of the main exertion muscles of the upper limb were recorded during the pull-up exercise test.Results After the training intervention,the number of pull-ups completed by the experimental group and control group increased by 1.74 times and 1.42 times,respectively.Subjects in both groups showed significant improvements in their MVC and lat pull-down maximal repetitions under 80％1RM loading.However,there were no statistical differences in these indicators between groups.Activation levels of the agonist muscles brachioradialis,posterior deltoid,and pectoralis major were significantly decreased after the training compared to those before training for both groups.In addition,the coactivation level of the antagonist triceps brachii muscle in the experimental group significantly decreased from 0.50±0.22 to 0.37±0.09 after the training,while there was no significant change in the control group before and after the intervention.Conclusions Eight-week tDCS combined with resistance training and resistance training alone can significantly improve the pull-up performance of college students,which may be related to the fact that both types of training can significantly improve the active muscle contraction capacity.Combined with resistance training,tDCS is more effective in decreasing the coactivation level of triceps brachii during pull-ups and increasing the contraction efficiency of elbow joint muscles.

Objective To explore the relationship between plasma amyloid-β(Aβ)and cognitive impairment.Methods A total of all villagers(aged 40 years and above)from two villages of Xi'an,China,were enrolled.A validated Chinese version of the Mini-Mental State Examination and neuropsychological battery were used to assess cognition.Levels of fasting plasma Aβ1-42 and Aβ1-40 were tested using commercial enzyme-linked immunosorbent assay(ELISA).Relationship between plasma Aβ and cognitive impairment was analyzed using Logistic regression analysis.Results Of the 1 314 enrolled subjects,1 180(89.80％)had normal cognition,85(6.47％)had suspected cognitive impairment,and 49(3.73％)had probable cognitive impairment.Univariate analysis showed that plasma Aβ1-42/Aβ1-40 ratio was higher in the suspected cognitive impairment group than in the probable cognitive impairment group(P＜0.05)and normal cognitive group(P＜0.05);plasma Aβ1-42 level in the suspected cognitive impairment group was higher than that in normal cognitive group(P＜0.05).The level of Aβ1-40 did not differ between the three groups.After correcting for confounding factors(including age,gender,degree of education,cognitive impairment risk factors,habits of living)in the multivariate Logistic regression analysis,the results were consistent with those in the univariate analysis.Conclusion Levels of plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio were elevated in patients with suspected cognitive impairment,indicating that elevated plasma Aβ1-42 and Aβ1-42/Aβ1-40 ratio may be more pronounced in early stage of cognitive impairment.They may be early biomarkers for cognitive impairment,which can help identify and intervene the disease earlier.

Objective:To demonstrate the clinical significance of group A streptococcal infection (GAS) in patients with enthesitis related arthritis (ERA).Methods:A retrospective study was conducted on ERA (136) and PolyRF-/Oligo juvenile idiopathic arthritis (JIA) (272) patients in Beijing Children's Hospital from 2016 to 2018. Anti-streptococcal hemolysin "O" (ASO) was tested and documented in all patients. The infection rate of GAS was compared between patients with ERA and PolyRF-/Oligo JIA. Patients with ERA were divided to two groups according to the result of ASO (ASO positive and ASO negative). All the clinical data were documented and compared within the two groups. The statistical methods used mainly include t test, rank sum test, chi-square test, and Spearman correlation analysis.Results:The GAS infection rate of patients with ERA was higher than patients with PolyRF-/Oligo JIA (17.6% vs 9.5%, χ2=5.52, P=0.019). In ERA patients, clinical data were analyzed, and a statistical significant difference was observed in the presence of human leukocyte antigen (HLA)-B27 between ASO positive and ASO negative group [75.0%(18/24) vs 49.1%(55/112), χ2=5.329, P=0.021]. Statistical differences were found in Patrick's sign positive rate between the two groups [100%(24/24) vs 67.0%(75/112), χ2=10.61, P=0.001]. There was statistically significant difference between the two groups regarding the radiogr-aphic grading at the sacroiliac joint. More patients with positive ASO had grade Ⅲ damage at the sacroiliac joint compare to patients with negative ASO [68.2%(15/22) vs 28.4%(29/102), χ2=12.49, P<0.001]. The logarithmic of the ASO was slightly correlated with the radiographic grade of sacroiliac joint ( r=0.26, P=0.005). Conclusion:Patients with ERA are prone to be infected by GAS. It's probably related to HLA-B27 postivity for antigen presentation. Patients who were infected by GAS fre-quently have sacroiliac joint involvement, and tend to be more sever. This indicates that GAS may play an important role in the pathogenesis of sacroiliac joint destruction.

Studies on coat protein I (COPI) have contributed to a basic understanding of how coat proteins generate vesicles to initiate intracellular transport. The core component of the COPI complex is coatomer, which is a multimeric complex that needs to be recruited from the cytosol to membrane in order to function in membrane bending and cargo sorting. Previous structural studies on the clathrin adaptors have found that membrane recruitment induces a large conformational change in promoting their role in cargo sorting. Here, pursuing negative-stain electron microscopy coupled with single-particle analyses, and also performing CXMS (chemical cross-linking coupled with mass spectrometry) for validation, we have reconstructed the structure of coatomer in its soluble form. When compared to the previously elucidated structure of coatomer in its membrane-bound form we do not observe a large conformational change. Thus, the result uncovers a key difference between how COPI versus clathrin coats are regulated by membrane recruitment.
ADP-Ribosylation Factor 1 ; chemistry ; metabolism ; Animals ; Coatomer Protein ; chemistry ; metabolism ; Cytosol ; chemistry ; metabolism ; GTPase-Activating Proteins ; chemistry ; metabolism ; Humans ; Membranes, Artificial ; Rats

Background Herpes stromal keratitis (HSK) is a common infectious ocular surface disease,with a higher recurrent rate,especially in necrotizing HSK.The diagnosis of HSK primarily depends on signs and symptoms,and specific laboratory diagnostic is lack.Objective This study was to clarify the expression of herpes simplex virus (HSV) in the corneal epithelium scrapings and tears of necrotizing HSK patients.Methods Thirty eyes of 30 patients with necrotizing HSK were enrolled in Nanjing Hospital of Nanjing Medical Hospital from September 2012 to September 2013 under the patient's informed consent.The eyes were examined by slit lamp microscope and scored.HSK patients received local and systemic therapy for 8 weeks and then an oral maintenance dose for 6 months.Corneal epithelial scrapings and tears samples were collected for HSV DNA detection by real-time PCR before and the 1 st,2nd,4th,6th and 8th week after therapy respectively.The difference of HSV positive rate was compared between corneal epithelium scrapings and tears samples using Chi-square test.Multilevel mixed effective model was employed to evaluate HSV concentration change in the samples at various time points in the HSV-positive patients of initial visit.The correlation between HSV concentration and clinical score was analyzed by Spearman rank correlation.Results HSV-positive rate was 46.4％ (13/30) in the corneal epithelial scrapings and 13.3％(4/30) in the tear samples,showing a significant difference between them (P =0.006).HSV-positive rate was significantly lower in the corneal epithelial scrapings 1 week,2 weeks and 4 weeks after treatment than before (P =0.001,0.003,0.004),and no HSV was detected 6 weeks and 8 weeks after treatment.No significant change in HSV-positive rate in tear samples in 1 week and 2 weeks after treatment in comparison with before treatment (P =1.000,0.583),and no HSV was detected after 4 weeks following treatment.The HSV concentration was 2460 (2 165-636500)/ml in initial 13 HSV-positive eyes of corneal epithelial scrapings and 0 (0-1150)/ml in initial 13 HSV-positive eyes of tear samples.Multilevel mixed effective model determined that HSV concentration was significantly lower in corneal epithelial scraping than that in tear (P =0.005),and HSV concentration was reduced with the lapse of time (P =0.001),with the faster rate of decline in the corneal epithelial scrapings (P =0.049).A positive correlation was found between initial HSV concentration and clinical scores (rs =0.844,P =0.000).Conclusiors Real-time PCR appears to be a powerful molecular tool for the detection of HSV in the HSK,especially in corneal epithelial scrapings of lesion.The initial positive outcome of viral DNA in corneal epithelial scrapings predicts a severe clinical procedure.