Ventilator is one of important medical equipment for the treatment of patients with critically ill. With the continuous development of medical technology,the structural performance of ventilators tends to be more precision,and the daily maintenance and repair of equipment become more important. Air-oxygen mixing is an important module of gas supply of ventilator,which structure includes access pathway of air,access pathway of oxygen and a pressurization section of air-oxygen mixing. The function of air path control is controlling air flow volume and pressure,which is basis of ensuring safe ventilation,and which includes both flow volume control system and safety valve system. Combined with the actually clinical application of ventilator,the working principles of air-oxygen mixing and air path control of the ventilator were analyzed and the maintenance methods of common faults were summarized from the key components of maintenance and repair,so as to improve the clinical service capability of ventilator equipment and the management level of hospital.

Objective To conduct the biomechanical analysis on a new power-assisted knee orthosis.Methods A self-force source power-assisted knee orthosis was used,and four motions(level walking,sitting and standing,ascending and descending stairs)were measured before and after wearing the orthosis.A musculoskeletal multibody dynamic model was adopted to calculate the joint angles and pressures at the knee,patellofemoral and hip joints.The effects of power-assisted knee orthosis on biomechanical changes of lower limbs were investigated by comparing the joint angles and pressures before and after wearing this orthosis.Results The orthosis would reduce the knee angles during level walking,as well as the knee pressures during sitting and standing on the wearing side.Wearing the orthosis did not significantly affect the joint angles during sitting and standing;however,it led to a significant decrease in joint pressures at both bilateral knee joints and patellofemoral joints.During ascending and descending stairs,the knee angle change on the wearing side was opposite to that on the non-wearing side.The increase of the peak knee angle was(14.3±3.6)%on the non-wearing side during ascending stairs.Conclusions The power-assisted knee orthosis can offer a conservative treatment for individuals with various knee diseases by reducing joint angles and pressures in daily motions.

Metabolic-associated fatty liver disease has become a common chronic liver disease with changes in lifestyle and the increasing prevalence rate of overweight and obesity in adults and even children. The liver synthesizes bile acids via cholesterol metabolism, which are important signaling molecules that modulate and regulate host glucose, lipid metabolism, and immunity. Abnormal bile acid metabolism closely correlates with the occurrence and progression of metabolic-associated fatty liver disease. This article systematically organizes the research of bile acid metabolism in children and adults with metabolic-associated fatty liver disease from the perspective of analyzing bile acid profiles by mass spectrometry detection, and compares the characteristics of bile acid metabolic disorders across different age groups and different developmental stages of disease so as to provide a reference for subsequent research.

Objective To conduct the biomechanical analysis on a new power-assisted knee orthosis.Methods A self-force source power-assisted knee orthosis was used,and four motions(level walking,sitting and standing,ascending and descending stairs)were measured before and after wearing the orthosis.A musculoskeletal multibody dynamic model was adopted to calculate the joint angles and pressures at the knee,patellofemoral and hip joints.The effects of power-assisted knee orthosis on biomechanical changes of lower limbs were investigated by comparing the joint angles and pressures before and after wearing this orthosis.Results The orthosis would reduce the knee angles during level walking,as well as the knee pressures during sitting and standing on the wearing side.Wearing the orthosis did not significantly affect the joint angles during sitting and standing;however,it led to a significant decrease in joint pressures at both bilateral knee joints and patellofemoral joints.During ascending and descending stairs,the knee angle change on the wearing side was opposite to that on the non-wearing side.The increase of the peak knee angle was(14.3±3.6)%on the non-wearing side during ascending stairs.Conclusions The power-assisted knee orthosis can offer a conservative treatment for individuals with various knee diseases by reducing joint angles and pressures in daily motions.

Metabolic-associated fatty liver disease has become a common chronic liver disease with changes in lifestyle and the increasing prevalence rate of overweight and obesity in adults and even children. The liver synthesizes bile acids via cholesterol metabolism, which are important signaling molecules that modulate and regulate host glucose, lipid metabolism, and immunity. Abnormal bile acid metabolism closely correlates with the occurrence and progression of metabolic-associated fatty liver disease. This article systematically organizes the research of bile acid metabolism in children and adults with metabolic-associated fatty liver disease from the perspective of analyzing bile acid profiles by mass spectrometry detection, and compares the characteristics of bile acid metabolic disorders across different age groups and different developmental stages of disease so as to provide a reference for subsequent research.

Ventilator is one of important medical equipment for the treatment of patients with critically ill. With the continuous development of medical technology,the structural performance of ventilators tends to be more precision,and the daily maintenance and repair of equipment become more important. Air-oxygen mixing is an important module of gas supply of ventilator,which structure includes access pathway of air,access pathway of oxygen and a pressurization section of air-oxygen mixing. The function of air path control is controlling air flow volume and pressure,which is basis of ensuring safe ventilation,and which includes both flow volume control system and safety valve system. Combined with the actually clinical application of ventilator,the working principles of air-oxygen mixing and air path control of the ventilator were analyzed and the maintenance methods of common faults were summarized from the key components of maintenance and repair,so as to improve the clinical service capability of ventilator equipment and the management level of hospital.

Morita therapy has been bom for more than 100 years.Inpatient Morita therapy is highly oper-able and easy to master.It can improve many refractory neuroses through four-stage treatment.But more neuroses are treated in outpatient clinics,and Morita therapy cannot be used in hospitalized patients.Therefore,the formula-tion of expert opinions on outpatient operations is particularly important.This paper is based on domestic and for-eign references,and after many discussions by domestic Morita therapy experts,and then drew up the first version of the expert opinions on operation of outpatient Morita therapy.Meanwhile the operation rule of Morita therapy in three stages of outpatient treatment was formulated:in the etiological analysis stage,under the theoretical guidance of Morita therapy,analyze the pathogenic factors,to improve treatment compliance and reduce resistance;during the operating stage,guide patients to engage in constructive and meaningful actions,realizing the achievement of letting nature take its course principle;in the cultivating character and enriching life stage,pay attention to positive infor-mation,expanding the scope and content of actions,improving the ability to adapt to complex life,and preventing recurrence caused by insufficient abilities.It will lay a foundation for the promotion of Morita therapy in domestic outpatient clinics,so that more patients with neurosis and other psychological diseases could receive characteristic Morita therapy treatment in outpatient clinics.

Objective:To investigate the effects of different tube voltages combined with artificial intelligence reconstruction algorithm(CI)on the computed tomography(CT)imaging quality and radiation dose of chest phantom on the basis of the CT scan for an adult male simulated chest phantom(PH-N1).Methods:A 512-slice CT scanner of ultrahigh-end was adopted to conduct scan,and the images were divided into 70 kV group,80 kV group,100 kV group and 120 kV group according to different tube voltage.For 4 groups of CT scan images with different tube voltages,the 10%,30%,50%,70%and 90%CI were adopted to reconstruct 1mm thin layer image.The CT volume dose index(CTDIvol)and the dose-length product(DLP)of the scans of 4 groups were compared.The CT values and standard deviation(SD)values of the aorta,abdominal wall fat and erector spine muscle were measured.Two senior diagnostic physicians with more than 5 years of work experience independently and double-blindly evaluated the image quality by using 5-point scale.A Kappa consistency test was conducted.One-way analysis of variance was adopted to compare the differences of CT values and SD values of the tissues of image targets.The Friedman rank-sum test was adopted to compare the differences of subjective image qualities among different groups.Results:The differences of CTDIvol and DLP among 4 groups with different tube voltages were significant(F=1855.617,3996.118,P<0.05),respectively.Under 70 kV tube voltage,there were no significant differences in CT values of the aorta,abdominal wall fat and erector spine muscle,which were reconstructed by using 10%,30%,50%,70%and 90%CI(P>0.05),while the differences of SD values among them were statistically significant(F=32.267,53.327,14.873,P<0.05),respectively.Under the different tube voltages of 4 groups,which were reconstructed by 90%CI,the CT values of aorta,abdominal wall fat and erector spine muscle gradually decreased with decreasing of tube voltage,the differences were significant(F=139.899,2563.93,219.231,P<0.05),respectively.The consistency of subjective scores between two diagnostic physicians was better for each group of images(Kappa=0.712～0.869).Conclusion:Compared with 80 kV,90 kV and 120 kV images,the reconstructed images with 90%CI algorithm under 70 kV tube voltage can significantly reduce the radiation dose,and the images have a favorable signal-to-noise ratio at the same time.

Objective To observe the effect of pre-hospital and intra-hospital collaborative ther-apeutic model in the treatment of patients with acute cerebral infarction.Methods A total of 67 pa-tients with acute cerebral infarction were selected as the research objects,and they were divided into observation group(n=37)and control group(n=30)according to the therapeutic model.The con-trol group was conducted with the traditional therapeutic model,while the observation group was con-ducted with the pre-hospital and intra-hospital collaborative therapeutic model.The time efficiency of intravenous thrombolysis,early recovery of nerve function and oxidative stress indexes were compared between the two groups.Results There was no significant difference in the time from onset to visit between the two groups(P＞0.05);the time from seeing a doctor to thrombolysis and the time from seeing a doctor to signing the informed consent for intravenous thrombolysis in the observation group were significantly shorter than those in the control group(P＜0.05).On the hospital admission,there was no significant difference in the National Institutes of Health Stroke Scale(NIHSS)score be-tween the two groups(P＞0.05);at the time points of 7 days after admission and 90 days after thrombolysis,the NIHSS scores of patients in the observation group were significantly lower than that in the control group(P＜0.05).There were no significant differences in the levels of serum glutathione peroxidase(GSH-Px)and malonaldehyde(MDA)between the two groups(P＞0.05);the level of serum superoxide dismutase(SOD)in the observation group was significantly higher than that in the control group(P＜0.05).One patient died in the control group,with a mortality rate of 3.33％;no patient died in the observation group.Conclusion Pre-hospital and intra-hospital collaborative therapeutic model can effectively improve the time efficiency of intravenous thrombolysis for patients with acute cerebral infarction,alleviate the neurological damage,and reduce degree of oxidative stress reaction and death risk.

Objective:To construct machine learning models based on CT imaging and clinical parameters for predicting progression-free survival (PFS) of locally advanced cervical cancer (LACC) patients after concurrent chemoradiotherapy (CCRT).Methods:Clinical data of 167 LACC patients treated with CCRT at Shandong Cancer Hospital from September 2015 to October 2021 were retrospectively analyzed. All patients were randomly divided into the training and validation cohorts according to the ratio of 7 vs. 3. Clinical features were selected by univariate and multivariate Cox proportional hazards model ( P<0.1). Radiomics models and nomograms were constructed by radiomics features which were selected by least absolute shrinkage and selection operator (LASSO) Cox regression model to predict the 1-, 3- and 5-year PFS. Combined models and nomogram models were developed by selected clinical and radiomics features. The Kaplan Meier-curve, receiver operating characteristic (ROC) curve, C-index and calibration curve were used to evaluate the model performance. Results:A total of 1 409 radiomics features were extracted based on the region of interest (ROI) in CT images. CT radiomics models showed better performance for predicting 1-, 3-and 5-year PFS than the clinical model in the training and validation cohorts. The combined model displayed the optimal performance in predicting 1-, 3-and 5-year PFS in the training cohort [area under the curve (AUC): 0.760, 0.648, 0.661, C-index: 0.740, 0.667, 0.709] and verification cohort (AUC: 0.763, 0.677, 0.648, C-index: 0.748, 0.668, 0.678).Conclusions:Combined model constructed based on CT radiomics and clinical features yield better prediction performance than that based on radiomics or clinical features alone. As an objective image analysis approach, it possesses high prediction efficiency for PFS of LACC patients after CCRT, which can provide reference for clinical decision-making.