The COVID-19 epidemic has spread to the whole world for three years and has had a serious impact on human life, health and economic activities. China's epidemic prevention and control has gone through the following stages: emergency unconventional stage, emergency normalization stage, and the transitional stage from the emergency normalization to the "Category B infectious disease treated as Category B" normalization, and achieved a major and decisive victory. The designated hospitals for prevention and control of COVID-19 epidemic in Tianjin has successfully completed its tasks in all stages of epidemic prevention and control, and has accumulated valuable experience. This article summarizes the experience of constructing a hospital infection prevention and control system during the "Category B infectious disease treated as Category A" period in designated hospital. The experience is summarized as the "Cluster" hospital infection prevention and control system, namely "three rings" outside, middle and inside, "three districts" of green, orange and red, "three things" before, during and after the event, "two-day pre-purification" and "two-director system", and "one zone" management. In emergency situations, we adopt a simplified version of the cluster hospital infection prevention and control system. In emergency situations, a simplified version of the "Cluster" hospital infection prevention and control system can be adopted. This system has the following characteristics: firstly, the system emphasizes the characteristics of "cluster" and the overall management of key measures to avoid any shortcomings. The second, it emphasizes the transformation of infection control concepts to maximize the safety of medical services through infection control. The third, it emphasizes the optimization of the process. The prevention and control measures should be comprehensive and focused, while also preventing excessive use. The measures emphasize the use of the least resources to achieve the best infection control effect. The fourth, it emphasizes the quality control work of infection control, pays attention to the importance of the process, and advocates the concept of "system slimming, process fattening". Fifthly, it emphasizes that the future development depends on artificial intelligence, in order to improve the quality and efficiency of prevention and control to the greatest extent. Sixth, hospitals need to strengthen continuous training and retraining. We utilize diverse training methods, including artificial intelligence, to ensure that infection control policies and procedures are simple. We have established an evaluation and feedback mechanism to ensure that medical personnel are in an emergency state at all times.

Traditional Chinese medicine fumigation device is the carrier of traditional Chinese medicine fumigation treatment. In recent years, with the rapid development of new technology and new materials, the development of fumigation device changes with each passing day, and a variety of new products continue to emerge. However, at present, the lack of corresponding evaluation norms, resulting in some difficulties in the registration, marketing, quality control, evaluation scale and other aspects of the product. Some products have many disadvantages in clinical use. From the perspective of technical review, this paper elaborates and analyzes the main concerns in technical review, such as product structure, main risks, performance requirements, clinical evaluation, etc., in order to provide a basis for the design, development, production, registration, use and post-marketing supervision of the devices.
Fumigation ; Medicine, Chinese Traditional ; Marketing ; Quality Control

Objective:To establish an automatic planning method using volumetric-modulated arc therapy (VMAT) for primary liver cancer (PLC) radiotherapy based on predicting the feasibility dose-volume histogram (DVH) and evaluate its performance.Methods:Ten patients with PLC were randomly chosen in this retrospective study. Pinnacle Auto-Planning was used to design the VMAT automatic plan, and the feasibility DVH curve was obtained through the PlanIQ dose prediction, and the initial optimization objectives of the automatic plan were set according to the displayed feasible objectives interval. The plans were accessed according to dosimetric parameters of the planning target volume and organs at risk as well as the monitor units. All patients′ automatic plans were compared with clinically accepted manual plans by using the paired t-test. Results:There was no significant difference of the planning target volume D 2%, D 98%, D mean or homogeneity index between the automatic and manual plans ((58.55±2.81) Gy vs.(57.98±4.17) Gy, (47.15±1.58) Gy vs.(47.82±1.38) Gy, (53.14±0.95) Gy vs.(53.44±1.67) Gy and 1.15±0.05 vs. 1.14±0.07, all P>0.05). The planning target volume conformity index of the manual plan was slightly higher than that of the automatic plan (0.77±0.08 vs. 0.69±0.06, P<0.05). The mean doses of normal liver, V 30Gy, V 20Gy, V 10Gy, V 5Gy and V< 5Gy of the automatic plan were significantly better than those of the manual plan ((26.68±11.13)% vs.(28.00±10.95)%, (29.96±11.50)% vs.(31.89±11.51)%, (34.88±11.51)% vs.(38.66±11.67)%, (45.38±12.40)% vs.(50.74±13.56)%, and (628.52±191.80) cm 3vs.(563.15±188.39) cm 3, all P<0.05). The mean doses of the small intestine, the duodenum, and the heart, as well as lung V 10 of the automatic plan were significantly less than those of the manual plan ((1.83±2.17) Gy vs.(2.37±2.81) Gy, (9.15±9.36) Gy vs.(11.18±10.49) Gy, and (5.44±3.10) Gy vs.(6.25±3.26) Gy, as well as (12.70±7.08)% vs.(14.47±8.11)%, all P<0.05). Monitor units did not significantly differ between two plans ((710.67±163.72) MU vs.(707.53±155.89) MU, P>0.05). Conclusions:The automatic planning method using VMAT for PLC radiotherapy based on predicting the feasibility DVH enhances the quality for PLC plans, especially in terms of normal liver sparing. Besides, it also has advantages for the protection of the intestine, whole lung and heart.

As a representative part of the oral system and masticatory robot system, the modeling method of the dental model is an important factor influencing the accuracy of the multi-body dynamic model. Taking the right first molars of the masticatory robot as the research object, an equivalent model, point-contact higher kinematic pair composed of v-shaped surface and sphere surface, was proposed. Firstly, the finite element method was used to analyze the occlusal dynamics of the original model in three static contact cases (intrusive contact, centric occlusion, and extrusive contact) and one dynamic chewing case, and the expected bite force was obtained. Secondly, the Hertz contact model was adopted to establish the analytical expression of the bite force of the equivalent model in three static contact cases. The normal vectors and contact stiffness in the expression were designed according to the expected bite force. Finally, the bite force performance of the equivalent model in three static contact cases and one dynamic chewing case was evaluated. The results showed that the equivalent model could achieve the equivalent bite force of 8 expected items in the static contact cases. Meanwhile, the bite force in the early and late stages of the dynamic chewing case coincides well with the original model. In the middle stage, a certain degree of impact is introduced, but it can be weakened by subsequent trajectory planning. The equivalent modeling scheme of the dental model proposed in this paper further improves the accuracy of the dynamic model of the multi-body system. It provides a new idea for the dynamic modeling of other complex human contacts.
Biomechanical Phenomena ; Bite Force ; Humans ; Mastication ; Molar

Masticatory robots have a broad application prospect in the field of denture material tests and mandible rehabilitation. Mechanism type of temporomandibular joint structure is an important factor influencing the performance of the masticatory robot. In view of the wide application of elastic components in the field of the biomimetic robot, an elastic component was adopted to simulate the buffering characteristics of the temporomandibular joint disc and formed the elastic temporomandibular joint structure on the basis of point-contact high pair. Secondly, the influences of the elastic temporomandibular joint structure (on mechanism degree, kinematics, dynamics, etc.) were discussed. The position and velocity of the temporomandibular joint were analyzed based on geometric constraints of the joint surface, and the dynamic analysis based on the Lagrange equation was carried out. Finally, the influence of the preload and stiffness of the elastic component was analyzed by the response surface method. The results showed that the elastic temporomandibular joint structure could effectively guarantee the flexible movement and stable force of the joint. The elastic joint structure proposed in this paper further improves the biomimetic behavior of masticatory robots. It provides new ideas for the biomimetic design of viscoelastic joint discs.

Stress distribution of denture is an important criterion to evaluate the reasonableness of technological parameters, and the bite force derived from the antagonist is the critical load condition for the calculation of stress distribution. In order to improve the accuracy of stress distribution as much as possible, all-ceramic crown of the mandibular first molar with centric occlusion was taken as the research object, and a bite force loading method reflecting the actual occlusal situation was adopted. Firstly, raster scanning and three dimensional reconstruction of the occlusal surface of molars in the standard dental model were carried out. Meanwhile, the surface modeling of the bonding surface was carried out according to the preparation process. Secondly, the parametric occlusal analysis program was developed with the help of OFA function library, and the genetic algorithm was used to optimize the mandibular centric position. Finally, both the optimized case of the mesh model based on the results of occlusal optimization and the referenced case according to the cusp-fossa contact characteristics were designed. The stress distribution was analyzed and compared by using Abaqus software. The results showed that the genetic algorithm was suitable for solving the occlusal optimization problem. Compared with the reference case, the optimized case had smaller maximum stress and more uniform stress distribution characteristics. The proposed method further improves the stress accuracy of the prosthesis in the finite element model. Also, it provides a new idea for stress analysis of other joints in human body.
Bite Force ; Ceramics ; Crowns ; Dental Stress Analysis ; Finite Element Analysis ; Humans ; Molar ; Prostheses and Implants ; Stress, Mechanical

Objective To evaluate the effect of case-PBL method and case-PBL method combined with SPSS software on the teaching of medical statistics for medical undergraduates. Methods Students from two classes major in experimental medicine from Nantong University Xingling College were selected as Experimental Class 1 ( using case-PBL teaching ) and Experimental Class 2 ( using case-PBL teaching combined with SPSS software). Each class attended lessons for five times. The teachers would send cases for each lesson one week in advance, and students would form into groups to access information, learn and discuss independently. Representatives from groups spoke in class, members would complement and discuss, while teachers offered guidance, review, analysis and summary. We shortened the discussion time in the class, and added instructions on the operation steps of SPSS software for case analysis and how to interpret the analysis result correctly in Experiment Class 2 . The Control Class received traditional teaching . Questionnaires, process assessment and final assessment were used to evaluate teaching effectiveness. SPSS 21.0 software was used to implement variance analysis and chi-square test for comparison between groups. Results The scores of the two experimental classes were higher than those of the control class in the five process assessments ( P<0 . 05 ) . Experimental Class 2 was the best in three section process assessments including those of t-test, the rank sum test and the straight-line correlation (P<0.05). However, there was no difference in the theoretical test scores among the three classes (P=0.670). 94％-100％of the students in the two experimental classes believed that the teaching effects of the case-PBL method and case-PBL method combined with SPSS software were better than the traditional teaching method (P<0.05) in such areas as stimulating interest in learning, improving learning efficiency, etc. Students in Experimental Class 2 were more prone to think these methods improved teaching effect. Conclusion The case-PBL teaching combined with the application of SPSS software will further help students to systematically grasp the statistical knowledge and cultivate statistical practice ability . However , neither methods will improve students' theoretical test scores.

Lung cancer is one of the most common cancers in the world,which seriously affects people's physical and mental health.About 85％ of them are non-small cell lung cancers.In recent years,with the rapid development of low-dose computed tomography,Da Vinci robotic surgery and targeted therapy,the therapeutic effect of lung cancer has been greatly improved.However,due to the lack of early diagnosis of biomarkers,therapeutic targets and signs of prognosis,most patients have metastases when they are at the time of treatment.Lung cancer remains the leading cause of cancer-related death.CircRNA is a special endogenous non coding RNA,which is formed by the reverse splicing of the 3'splice donor site and the 5'splice acceptor site to form a covalent closed loop.It is highly conservative and stable.The expression level of circRNA in non-small cell lung cancer is obviously abnormal,which is closely related to the occurrence,development and metastasis of non-small cell lung cancer.It is expected to become an ideal biomarker,which is used for early diagnosis of non-small cell lung cancer,and provides new therapeutic targets and prognostic markers.

Objective Assessment of fenestration in the aortic arch disease .Methods 13 patients with aortic arch dis-ease underwent fenestration operation to reconstruct affiliated vessels , aortic arch aneurysm in 5 patients, aortic anch ulcer in 4, Ⅲ type aortic dissection in 3 and Ⅰ type leakage after aortic stent graft in 1 patient.All patieuts were divided into 2 groups.8 patients in pre-fenestration group, 5 patients in in-situ fenestration group.Only left subclavian artery was rebuilded in 9 patients, both left carotid common artery and left subclavian artery were rebuilded in 3 patients, all three affiliated vessels of arch were rebuilded in 1 patient.Results Branch vessels of aortic arch were successfully rebuilded in all 13 patients.There were no endoleak, stenosis of branch vessels, graft diaplacement or deaths peri-operative period.During follow-up, no postop-erative complications occurred and all target vessels remained patent .No fenestration related endoleaks were observed.Conclu-sion Fenestration may be a viable alternative for patients with aortic arch disease .

To evaluate the estimation of prevalence ratio (PR) by using bayesian log-binomial regression model and its application,we estimated the PR of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea in their infants by using bayesian log-binomial regression model in Openbugs software.The results showed that caregivers' recognition of infant's risk signs of diarrhea was associated significantly with a 13％ increase of medical care-seeking.Meanwhile,we compared the differences in PR's point estimation and its interval estimation of medical care-seeking prevalence to caregivers' recognition of risk signs of diarrhea and convergence of three models (model 1:not adjusting for the covariates;model 2:adjusting for duration of caregivers' education,model 3:adjusting for distance between village and township and child month-age based on model 2) between bayesian log-binomial regression model and conventional log-binomial regression model.The results showed that all three bayesian log-binomial regression models were convergence and the estimated PRs were 1.130(95％CI:1.005-1.265),1.128(95％CI:1.001-1.264)and 1.132(95％CI:1.004-1.267),respectively.Conventional log-binomial regression model 1 and model 2 were convergence and their PRs were 1.130(95％ CI:1.055-1.206) and 1.126(95％ CI:1.051-1.203),respectively,but the model 3 was misconvergence,so COPY method was used to estimate PR,which was 1.125 (95％CI:1.051-1.200).In addition,the point estimation and interval estimation of PRs from three bayesian log-binomial regression models differed slightly from those of PRs from conventional log-binomial regression model,but they had a good consistency in estimating PR.Therefore,bayesian log-binomial regression model can effectively estimate PR with less misconvergence and have more advantages in application compared with conventional log-binomial regression model.