Objective To investigate the effect of active muscle response on mechanical responses and injuries of human neck under high Gx loading.Methods A refined finite element model of the head and neck with active muscle response was established and validated based on the existing post-crash volunteer experiments.The effects of active muscle action on the kinematic and biomechanical responses of the neck were investigated under different G-value loads and at each tilting angle using this model.Results The stress distribution of vertebrae under high Gx load was dispersed from C4-7 to the whole vertebrae,and the active muscle action reduced the stress change,and the effect was significant under 8 G acceleration,which reduced the peak vertebral bone stress by 23.6％and 11.6％,and the peak intervertebral disc stress by 42.3％and 63.4％under 8 G and 10 G conditions,respectively.The maximum stress difference of 34.3 MPa was achieved by the active muscle action at 15° backward tilting.Conclusions The neck showed better stability by the active muscle action under the impact of high Gx loading.At different tilting angles,the active muscle action was more obvious in the backward tilting posture compared with the forward tilting and upright seated postures,and the backward tilting posture was safer to meet the impact when the same active muscle action was applied.The results can provide a reference for the subsequent studies related to the neck injury.

Objective To investigate the effect of active muscle response on mechanical responses and injuries of human neck under high Gx loading.Methods A refined finite element model of the head and neck with active muscle response was established and validated based on the existing post-crash volunteer experiments.The effects of active muscle action on the kinematic and biomechanical responses of the neck were investigated under different G-value loads and at each tilting angle using this model.Results The stress distribution of vertebrae under high Gx load was dispersed from C4-7 to the whole vertebrae,and the active muscle action reduced the stress change,and the effect was significant under 8 G acceleration,which reduced the peak vertebral bone stress by 23.6％and 11.6％,and the peak intervertebral disc stress by 42.3％and 63.4％under 8 G and 10 G conditions,respectively.The maximum stress difference of 34.3 MPa was achieved by the active muscle action at 15° backward tilting.Conclusions The neck showed better stability by the active muscle action under the impact of high Gx loading.At different tilting angles,the active muscle action was more obvious in the backward tilting posture compared with the forward tilting and upright seated postures,and the backward tilting posture was safer to meet the impact when the same active muscle action was applied.The results can provide a reference for the subsequent studies related to the neck injury.

Objective:To explore the correlation between high cholinergic pathway signaling and cognitive function in patients with Parkinson disease(PD) accompanied with sleep disorder.Methods:PD patients admitted from 2017 to 2022 were divided into PD with sleep disorder group (PD-SD group) ( n=56) and PD without sleep disorder group (PD-NSD group) ( n=41) according to the Parkinson's disease sleep scale (PDSS) score. All participants underwent magnetic resonance imaging examination.All patients were evaluated by the PDSS, Hoehn-Yahr (H-Y), Montreal cognitive assessment scale (MoCA), and cholinergic pathways hyper intensities scale (CHIPS). The difference of cognitive function between the two groups and the correlation between CHIPS and cognitive function were analyzed.Independent sample t-test, Spearman correlation analysis, and binary Logistic regression analysis were performed on the data by SPSS 26.0 statistical software. Results:(1)The MoCA score of the PD-SD group (22.00 (5.00)) was lower than that of the PD-NSD group (26.00 (5.00)) ( Z=-3.830, P<0.05). The total and all aspects scores of CHIPS in PD-SD group were higher than those in PD-NSD group(the total score of the low external capsule: 12.00(8.00), 0(8.00), the total score of the high external capsule: 12.00(2.00), 6.00(9.00), the total score of the radial crown: 8.00(0), 4.00(4.00), the total score of the centrum semiovale: 3.00(4.00), 0(2.00), the total score of the right side: 16.00(9.00), 5.00(10.00), the total score of the left side: 17.00(6.00), 7.00(9.00), the total score of CHIPS: 32.00(14.00), 14.00(20.00))( Z=-5.081, -5.873, -4.933, -3.211, -5.562, -6.232, -5.995, all P<0.05). (2)The correlation analysis between the score of CHIPS and cognitive function in the PD-SD group showed that, the total score of the low external capsule ( r=-0.286), the total score of the centrum semiovale ( r=-0.307), the total score of the right side ( r=-0.376), the total score of the left side ( r=-0.284) and the total score of CHIPS ( r=-0.349) were negatively correlated with MoCA(all P<0.05). (3)Binary Logistic regression analysis showed that white matter lesions in centrum semiovale, low inner capsule, right and left leukodystrophy were not influence factors for cognitive impairment (all P>0.05). Conclusion:PD patients with sleep disorders have lower cognitive function scores, higher CHIPS scores, and significant changes in white matter lesions compared to those without sleep disorders. In PD patients with sleep disorders, the higher the CHIPS score, the lower the cognitive function score, and the more significant the rate of cognitive impairment occurrence and development.

Chronic hepatitis B virus (HBV) infection is the main cause of viral hepatitis, liver cirrhosis, and primary liver cancer. At present, nucleos(t)ide analogues (NUC) and pegylated interferon α used in clinical practice cannot directly target covalently closed circular DNA, and it is difficult to achieve clinical cure of chronic hepatitis B patients; therefore, it is urgently needed to develop direct-acting antiviral agents targeting all stages of the HBV replication cycle. Capsid assembly modulator (CpAM) targets the assembly of viral capsids through various mechanisms, thereby exerting a direct-acting antiviral effect. Its combination with NUC should have a good synergistic antiviral effect, but the results of existing clinical trials have shown that chronic hepatitis B patients who received a limited course of antiviral therapy with CpAM and NUC all experienced off-therapy viral rebound. Based on the mechanism of action of these two types of drugs, this article provides a reasonable explanation for the above clinical trial results and points out that a longer course of antiviral therapy with CpAM and NUC may be needed in the future clinical trials with safe drug withdrawal as the end point of observation, so as to deplete or silence the pool of covalently closed circular DNA and increase the possibility of safe drug withdrawal in CHB patients. In addition, further studies are needed to explore antiviral therapeutic strategies with a combination of multiple targets.

Objective: To explore and analyze the possible mechanism of liver injury in patients with coronavirus disease 2019 (novel coronavirus pneumonia, NCP). Methods: The correlation between ALT, AST and other liver enzyme changes condition and NCP patients’ disease status reported in the literature was comprehensively analyzed. ACE2 expression in liver tissue for novel coronavirus was analyzed based on single cell sequencing (GSE115469) data. RNA-Seq method was used to analyze Ace2 expression and transcription factors related to its expression in liver tissues at various time-points after hepatectomy in mouse model of acute liver injury with partial hepatectomy. t-test or Spearman rank correlation analysis was used for statistical analysis. Results: ALT and AST were abnormally elevated in some patients with novel coronavirus infection, and the rate and extent of ALT and AST elevation in severe NCP patients were higher than those in non-severe patients. Liver tissue results of single cell sequencing and immunohistochemistry showed that ACE2 was only expressed in bile duct epithelial cells of normal liver tissues, and very low in hepatocytes. In a mouse model of acute liver injury with partial hepatectomy, Ace2 expression was down-regulated on the first day, but it was elevated up to twice of the normal level on the third day, and returned to normal level on seventh day when the liver recovered and hepatocyte proliferation stopped. Whether this phenomenon suggests that the bile duct epithelial cells with positive expression of Ace2 participate in the process of liver regeneration after partial hepatectomy deserves further study. In RNA-Seq data, 77 transcription factors were positively correlated with the expression of ACE2 (r > 0.2, FDR < 0.05), which were mainly enriched in the development, differentiation, morphogenesis and cell proliferation of glandular epithelial cells. Conclusion We assumed that in addition to the over activated inflammatory response in patients with NCP, the up-regulation of ACE2 expression in liver tissue caused by compensatory proliferation of hepatocytes derived from bile duct epithelial cells may also be the possible mechanism of liver tissue injury caused by 2019 novel coronavirus infection.

BACKGROUND:Intertrochanteric fracture can obtain good curative effects after active effective internal fixation in early stage.
OBJECTIVE:To compare dynamic hip screw+trochanter stabilizing plate and Gamma nail fixation for treatment of Evans type IIIB and type IV intertrochanteric fracture.
METHODS:A total of 67 patients with Evans type IIIB and type IV intertrochanteric fracture, including 28 cases undergoing dynamic hip screw+trochanter stabilizing plate and 39 cases undergoing Gamma nail, were selected from Chongming Branch, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from February 2009 to November 2012. Al patients received antibiotics and functional exercises after treatment. Time of therapy, intraoperative bleeding amount, fracture healing time and Harris Hip Score were retrospectively analyzed in patients of both groups.
RESULTS AND CONCLUSION:Al patients were fol owed up for 6-45 months, averagely 21 months. (1) One patient affected infection in the dynamic hip screw+trochanter stabilizing plate group. He was healed after fixation removal half a year after drug exchange. One obese patient experienced injury again during out-of-bed activity at 3 weeks after treatment in the Gamma nail group. Fracture appeared at distal end of lock pin, and healed after replaced by Gamma nail. Trochanteric stabilizing plate was unstable in four patients of the Gamma nail group. They affected severe pneumonia after over 6 weeks of lying in bed, and healed after treatment in the medical department (2) Coxa vara appeared in two cases of the dynamic hip screw+trochanter stabilizing plate group, and three cases in the Gamma nail group. Fracture healing was achieved in al patients. (3) The time of therapy was longer, and intraoperative bleeding amount was significantly more in the dynamic hip screw+trochanter stabilizing plate group compared with the Gamma nail group (P<0.05). No significant difference in healing time and Harris Hip Score was detected between the two groups (P>0.05). Dynamic hip screw+trochanter stabilizing plate and Gamma nail are effective methods for treatment of Evans type IIIB and type IV intertrochanteric fracture. To choose a suitable fixator, we should aggregately analyze fracture stability, healing state and the degree of osteoporosis.