BACKGROUND:Finite element analysis has been widely used for the research of bone and joint biomechanics, but the reports about finite element analysis of distal tibial articular surface defect are rare at home and abroad. OBJECTIVE:To establish ankle three-dimensional finite element model, produce distal tibial articular surface defects with different areas, and to simulate the distal tibial articular surface deformation and displacement under the different phases, thus predict the maximum al owable degree of distal tibial articular surface defect and explore the mechanics pathogenesis of ankle traumatic arthritis. METHODS:Continuous tomographic images were obtained by multi-slice spiral CT scan of a normal adult male ankle, and then the images were imported into the Mimics medicine modeling software to generate a entity model;the large general-purpose finite element analysis software ANSYS 13.0 was used for meshing, material property assignment and generating a finite element model. Restricted boundary conditions and simulated ankle distal end axial force, and then the stress distribution and displacement results of distal tibial articular surface in different phases were obtained. RESULTS AND CONCLUSION:The total number of units of the established finite element model of ankle joint was 157 990, and the total number of nodes was 193 801. On three phases, with the increase of the distal tibial defect area, the contact area was gradual y decreased, especial y in plantar flexion with the defect diameter of 13 mm, the change of the area was most obvious;The contact area of the neutral position was largest;with the increase of the distal tibial defect area in the neutral position and dorsiflexion, the peak stress was increased gradual y, and significantly increased after the diameter changed into 11-13 mm;in the neutral position and 10° of dorsiflexion, the peak stress mainly concentrated in the posteromedial and posterolateral quadrant;in 10° of plantar flexion, the change was complex, and when the diameter was 11-13 mm, the peak stress was increased gradual y with the increasing of defect area, when the diameter increased to 13 mm, the peak stress reached maximum. The maximum diameter of distal tibial articular surface defect was considered to be 11-13 mm. The joint function wil be affected when the diameter of distal tibial articular cartilage and bone bed defects was more than 11-13 mm.

Objective To investigate the role of protein phosphorylation in Pseudomonas aeruginosa (P.aeruginosa) strains in response to stress triggered by mouse macrophages.Methods The strong cation exchange-immobilized metal affinity chromatography (SCX-IMAC) was performed to enrich phosphopeptides.The nanoscale liquid chromatography coupled to tandem mass spectrometry (nano LC-MS/MS) was carried out to identify and analyze phosphoproteome.Results Fourteen phosphopeptides from twelve proteins were identified within thirty-one phosphorylation sites on serine,threonine and tyrosine residues.Fifty percent of these phosphorylated proteins were membrane proteins,indicating that their phosphorylation modification was more critical for bacteria in response to the stress.In terms of biological process of Gene Ontology,these identified proteins were involved in stress response,iron transport,anaerobic respiration,response to hydrogen peroxide and signal transduction by phosphorylation,etc.Conclusion These phosphorylated proteins in P.aeruginosa strains are necessary for signal transduction and their response to harsh environment within the macrophages,such as iron limitation,hypoxia and oxidative stress.This study provides evidence for further investigation on virulence and pathogenesis of P.aeruginosa.

Objective Comparing the effects of steam sterilization on cyclic fatigue of stainless steel files. Meth-ods Fifty instruments of 25# stainless steel K files were randomly divided into 5 groups, which include 10 in each group. Group 1 was the blank control group, group 2 to 5 were subjected to 1, 3, 4, 5 steam sterilization cycles, then the files were tested by a custom-made device to assess cyclic fatigue and the number of cycles of failure (NCF) was calculated. Microstruc-ture of each file’s fracture surface was analyzed by Scanning Electron microscope (SEM). Results NCF in the 5 groups were 4 345.2 ± 384.2,3 937.9 ± 645.4,3 812.9 ± 532.5,3 626.2 ± 380.0,3 625.9 ± 565.6 respectively, and the differences among 5 groups were significantly different(F=2.598, P<0.05). After 4 or 5 times of steam sterilization, cyclic fatigue de-creased if compared with that in control group (P<0.05). Fracture surface in group 1 and group 2 was tough dimple structure and large numbers of regular, deep dimples were distributed on the surface. You could also see micro cavities clearly formed by fracture;Fracture surface in group 4 was dimple structure in brittle intergranular morphology. It is characterized by the presence of thin brittle precipitates, clean and smooth crystal interface, and a great sense of polyhedral stereo. Conclusion After 4 times of steam sterilization, cyclic fatigue strength of 25# stainless steel K files declined, which possessed the poten-tial risk of fracture.

China Three Gorges University(CTGU) started undergraduate medical education for foreign students since 2004. Over the years,through continuous interaction with coordinators,CTGU grad-ually transited from passive teaching to active teaching. Firstly we determined basic principles,objectives and requirements of talent training programme. Secondly,we strengthen Chinese language teaching, reasonably adjusted professional curriculum and teaching content,added basic medical courses and rea-sonably arranged clinical practice based on the concrete situation in our country. in order to make the cur-riculum system consistent with the require-ments of talent training.

BACKGROUND:Recently, studies on three-dimensional reconstruction and biomechanics became more and more. Three-dimensional models of organs were established by modeling software based on image data using computer. Mechanical analysis was conducted using finite element analysis software. After literature retrieval, we found that the principle of three-dimensional reconstruction of human organs is not clear, and the process description is relatively simple. Some is not accorded with the fact. Above studies cannot guide related research. OBJECTIVE:To explore the principle, process, results and further application of three-dimensional reconstruction models of organs, and to provide evidence for future studies. METHODS:We retrieved China National Knowledge Infrastructure for representative literatures about three-dimensional reconstruction of human organs using the computer, and analyzed the principle, process, results and further application of three-dimensional reconstruction models of organs. RESULTS AND CONCLUSION:In combination with established three-dimensional bone models, we explained the principle, process, and application of three-dimensional reconstruction in detail, and laid the theoretical foundation for subsequent biomechanical research. With continuous development of tissue engineering technology, scholars have begun to study the pathogenesis of bone injury from various angles and different aspects so as to better prevent and treat this disease. The related research is stil in its primary stage, and stil needs further investigations. 

Objective: To investigate the trend in incidence of stroke in Nanshan District, Shenzhen City from 2010 to 2021, so as to provide the evidence for formulating the integrated strategy for stroke control. Methods: The data of stroke morbidity in Nanshan District from 2010 to 2021 were collected through Shenzhen Chronic Disease Prevention and Control Management System. The incidence of stroke was calculated, and standardized by the population of the Chinese Sixth National Census in 2010. The trends in stroke incidence were evaluated in Nanshan District from 2010 to 2021 using annual percent change (APC) and average annual percent change (AAPC), and gender-, age- and subtype-specific incidence of stroke was descriptively analyzed. Results: A total of 30 377 cases with stroke were reported in Nanshan District from 2010 to 2021, with a crude incidence rate of 190.45/105 and a standardized incidence rate of 405.65/105. The crude incidence rate of stroke appeared a tendency towards a rise in Nanshan District from 2010 to 2021 (APC=5.38%, t=4.678, P=0.001), and a higher crude incidence rate of stroke was seen among men than among women (227.57/105 vs. 148.40/105; χ2=1 309.580, P<0.001). The incidence of stroke appeared a tendency towards a rise with age (χ2trend =435.717, P<0.001), and there was a tendency towards a rise in stroke incidence among residents under 40 years of age (APC=2.89%, t=2.538, P=0.029). The crude incidence of ischemic stroke was 151.24/105, which was higher than that of hemorrhagic stroke (39.21/105) (χ2=10 521.000, P<0.001). Conclusions The incidence of stroke appeared a tendency towards a rise in Nanshan District from 2010 to 2021, with ischemic stroke as the predominant subtype of stroke. Males and middle-aged and elderly residents should be given a high priority for stroke prevention and treatment.

Objective: To investigate the prevalence of current smoking and smoking cessation, and identify the influencing factors among hypertensive patients in Nanshan District, Shenzhen City, so as to provide insights into smoking control among hypertensive patients. Methods: The demographic features, life style, status of smoking and smoking cessation in hypertensive patients were collected from 69 community health centers in Nanshan District from 2017 to 2019. The gender- and age-specific prevalence of smoking and smoking cessation was estimated among hypertensive patients, and the factors affecting hypertensive patients' smoking and smoking cessation were identified using a multivariable logistic regression model. Results: Totally 4 385 patients with hypertension were enrolled, with a mean age of (58.41±11.19) years, and the participants included 2 265 men (51.65%) and 2 120 women (48.35%). There were 724 current smokers, and the prevalence of current smoking was 16.51%, with 29.71% prevalence in males and 2.41% in females. There were 424 hypertensive patients quitting smoking, and the prevalence of smoking cessation was 36.93%, with 38.20% prevalence in males. Multivariable logistic regression analysis identified male ( OR=12.885, 95%CI: 9.567-17.354 ) and drinking ( OR=2.567, 95%CI: 2.118-3.111 ) as facilitating factors for current smoking among hypertensive patients, and increasing age (OR=0.723, 95%CI: 0.642-0.815) and high exercise frequency (OR=0.881, 95%CI: 0.817-0.950) as barrier factors, while male ( OR=7.309, 95%CI: 3.304-16.165), increasing age ( OR=1.381, 95%CI: 1.120-1.703 ), unmarried ( OR=1.819, 95%CI: 1.329-2.490 ), divorced ( OR=7.837, 95%CI: 1.254-48.975 ), retired ( OR=1.545, 95%CI: 1.095-2.180 ), unemployed (OR=1.801, 95%CI: 1.057-3.066), and high exercise frequency ( OR=1.221, 95%CI: 1.096-1.360 ) were identified as facilitating factors for smoking cessation among hypertensive patients and widowed ( OR=0.285, 95%CI: 0.089-0.906 ), high educational level ( OR=0.766, 95%CI: 0.619-0.949 ), and drinking ( OR=0.488, 95%CI: 0.368-0.647 ) as barrier factors. Conclusions The prevalence of smoking is lower, and the prevalence of smoking cessation is higher among hypertensive patients than among general populations in Nanshan District. Young and middle-aged, employed, widowed men with a high educational level are key populations for tobacco control, and alcohol consumption control and intensified exercises are important measures to reduce the prevalence of smoking and improve the prevalence of smoking cessation.

Objective: To analyze the influencing factors for hospitalization costs among stroke patients with different subtypes, so as to provide the reference for reducing the economic burden of patients. Methods: Data of patients with hemorrhagic or ischemic stroke who were discharged from hospitals in Nanshan District, Shenzhen City from January 1, 2016 to December 31, 2021 were collected through Hospital Information System. Hospitalization costs were analyzed between hemorrhagic and ischemic stroke patients, and factors affecting hospitalization costs among stroke patients with different subtypes were identified using a structural equation model. Results: A total of 10 298 patients with stroke were recruited, including 2 820 patients with hemorrhagic stroke (27.38%) and 7 478 patients with ischemic stroke (72.62%). The patients with hemorrhagic stroke had a median duration of hospital stay of 19.00 (interquartile range, 18.00) d, and a median hospitalization cost of 26 759.48 (interquartile range, 51 000.87) Yuan. The patients with ischemic stroke had a median duration of hospital stay of 12.00 (interquartile range, 10.00) d, and a median hospitalization cost of 12 199.87 (interquartile range, 13 290.20) Yuan. Structural equation model analysis showed that department of hospitalization, discharge status, ways of leaving hospital, surgery and hypertension had direct effects on hospitalization costs and indirect effects on hospitalization costs through duration of hospital stay among hemorrhagic stroke patients, and duration of hospital stay had the highest total effect (0.684), followed by surgery (0.632). Employment status, admission route, department of hospitalization, ways of leaving hospital, payment mode, surgery and dyslipidemia had direct effects on hospitalization costs and indirect effects on hospitalization costs through duration of hospital stay among ischemic stroke patients, and duration of hospital stay (0.746), surgery (0.424) and department of hospitalization (0.151) ranked the top three in total effects. Conclusion The hospitalization cost is relatively high among stroke patients in Nanshan District, and duration of hospital stay and surgery have great influence on hospitalization costs among stroke patients with different subtypes.

Objective To investigate the prevalence of DUOX2 mutations in Chinese patients with congenital hypothyroidism (CH) and to discuss the inheritance pattern of DUOX2 gene.Methods Blood samples were collected from 91 CH children and their genomic DNA was extracted from peripheral blood leukocytes.All exons and exon-intron boundaries of DUOX2 were analyzed by target next-generation sequencing and family trios was established to study the inheritance pattern of DUOX2 gene.Results Fifty-four out of 91 children with CH carried DUOX2 mutation, with a prevalence of 59.34%.Of the 54 CH children, 36 carried DUOX2 biallelic mutations.In all 12 family trios with probands carrying biallelic DUOX2 mutations, the parents carried heterozygous DUOX2 mutations while still showing normal thyroid function, suggesting that CH caused by DUOX2 mutations is inherited in an autosomal recessive manner.Conclusion DUOX2 gene is one of the most frequently mutated genes in Chinese CH patients and its inheritance pattern is an autosomal recessive one.

Objective:To compare the effectivity and safety of ureteral stenting and percutaneous nephrostomy for patients with upper urinary calculi and sepsis.Methods:From June 2013 to June 2019, 429 patients with upper urinary calculi and urosepsis were accepted in the second hospital of Tianjin Medical University. According to surgical decompression, patients were divided into two groups, ureteral stenting (US, n=304) and percutaneous nephrostomy (PCN, n=125).121 patients were accompanied with septic shock in US group, 56 in PCN group. The effectivity of decompression was analyzed separately in patients with or without shock. For decompression, data included the success rate of decompression, the time of infection related parameters (temperature, blood WBC and CRP) returning to normal and the complications (progress of infection within 30min after decompression, perforation of ureter or pelvis). When urosepsis was cured, ureteroscopic lithotripsy was followed for all patients. The operation time, the stone free rate, the rate of using RIRS and the complications were compared.Results:For patients without septic shock, the success rate of decompression in PCN was higher (68/69)than that of US(165/183)( P =0.025); there was no significant difference in hospital stay for infection control and the time of infection related parameters (temperature, blood WBC and CRP) returning to normal ( P>0.05). The rate of infection progress within 30min in US(25/183) was higher than PCN(3/69)( P=0.036). When ureteroscopic lithotripsy was mentioned, the operation time in US(38.5±6.8 min) was longer than PCN(32.8±4.5 min)( P=0.000), the stone free rate and the rate of using RIRS were lower in PCN( P=0.044, P=0.0002). For patients with septic shock, the success rate of decompression in PCN was higher (55/56)than that of US(106/121)( P=0.022). The rate of infection progress within 30min after decompression was still higher in US ( P=0.048), the time of infection related parameters (temperature, blood WBC and CRP) returning to normal was shorter in PCN ( P=0.000, P=0.003, P=0.000). For lithotripsy, the operation time was longer in US ( P=0.017), the stone free rate and the rate of using RIRS were lower in PCN ( P=0.024, P=0.005). Conclusions:For patients with upper urinary calculi and urosepsis, both ureteral stenting and percutaneous nephrostomy can drainage the pelvis effectively. PCN provides quick recovery, especially when septic shock is involved. For the following ureteroscopic lithotripsy, PCN contributes to less operation time and higher stone free rate, reduces the use of flexible ureteroscope.