Objective:To explore the effectiveness of robotic implant technology in the postgraduate education of implant dentistry.Methods:The teaching method that combines of theory and model manipulation was used to teach 20 postgraduate students. After completing the theoretical course of implant dentistry, all students performed free hand, digital template, and dental implant robot implant surgery on the simulation jaw models. At the end of the course, an error analysis of the three and a feedback questionnaire distributed to the students were conducted in order to assess the effectiveness of the dental implant robot.Results:Compared to the freehand [2.45(1.1) mm,2.80(0.88) mm,4.95°(2.68°)] and digital template group [1.25(0.68) mm,2.00(0.90) mm, 3.35°(1.60°)], the dental robot implant group had smaller values for implant platform deviation, apical deviation and angular deviation [0.29(0.08) mm,0.26(0.20) mm,0.72°(0.13°)], and the difference was statistically significant ( P<0.001). The results of the questionnaire showed that dental implant robot helps to ensure the accuracy and safety of the implanting process and stimulates students′ interest in learning. Conclusions:At postgraduate level, the safety and accuracy of the implantation process was effectively improved and good teaching result achieved by introducing dental implant robot into the process of dental implant training.

Objective:To explore the effectiveness of robotic implant technology in the postgraduate education of implant dentistry.Methods:The teaching method that combines of theory and model manipulation was used to teach 20 postgraduate students. After completing the theoretical course of implant dentistry, all students performed free hand, digital template, and dental implant robot implant surgery on the simulation jaw models. At the end of the course, an error analysis of the three and a feedback questionnaire distributed to the students were conducted in order to assess the effectiveness of the dental implant robot.Results:Compared to the freehand [2.45(1.1) mm,2.80(0.88) mm,4.95°(2.68°)] and digital template group [1.25(0.68) mm,2.00(0.90) mm, 3.35°(1.60°)], the dental robot implant group had smaller values for implant platform deviation, apical deviation and angular deviation [0.29(0.08) mm,0.26(0.20) mm,0.72°(0.13°)], and the difference was statistically significant ( P<0.001). The results of the questionnaire showed that dental implant robot helps to ensure the accuracy and safety of the implanting process and stimulates students′ interest in learning. Conclusions:At postgraduate level, the safety and accuracy of the implantation process was effectively improved and good teaching result achieved by introducing dental implant robot into the process of dental implant training.

BACKGROUND:Rapid developments in the field of bioinformatics have provided new methods for the diagnosis of osteoarthritis.Artificial neural networks have powerful data computing and classification capabilities,which have shown better performance in disease diagnosis. OBJECTIVE:To establish a new diagnostic predictive model of osteoarthritis based on artificial neural network and to verify the diagnostic value of the model in osteoarthritis with an external dataset. METHODS:The eligible osteoarthritis-related data sets were downloaded through GEO database search and divided into Train group and Test group.The gene expression matrix of the Train group was analyzed to screen the differentially expressed genes.GO and KEGG enrichment analyses were performed on the differentially expressed genes.Through Lasso regression model,support vector machine model and random forest tree model,the key genes of osteoarthritis were further identified from the differentially expressed genes.The R software"Neuralnet"package was then used to construct the osteoarthritis diagnosis model based on artificial neural network,and the model performance was evaluated by the five-fold cross-validation.Two independent data sets in the Test group were used to verify their diagnostic results. RESULTS AND CONCLUSION:A total of 90 differentially expressed genes related to osteoarthritis were obtained by differential analysis,of which 33 were down-regulated and 57 were up-regulated.GO enrichment analysis showed that the differentially expressed genes were mainly involved in the following biological processes,including leukocyte-mediated immunity,leukocyte migration in bone marrow and chemokine production.KEGG enrichment analysis showed that these genes were mainly enriched in rheumatoid arthritis,interleukin-17 signaling pathway and osteoclast differentiation pathway.Five key genes for the diagnosis of osteoarthritis,HMGB2,GADD45A,SLC19A2,TPPP3 and FOLR2,were identified by three machine learning methods.The artificial neural network model of five key genes in the Train group showed that the accuracy was 96.36%and the area under the curve was 0.997.The five-fold cross validation of the neural network model showed that the average area under the curve was greater than 0.9 and the model was of robustness.Two independent data sets in the Test group showed its area under the curve was 0.814 and 0.788 respectively.Therefore,the establishment of an artificial neural network model for the diagnosis of osteoarthritis has a certain diagnostic value.

Background A large amount of iron deposition in the brain can cause neuronal damage by inducing oxidative stress, neuroinflammation, and abnormal mitochondrial function. In addition, iron deposition is also reported to be closely related to the pathogenesis of Alzheimer's disease (AD). The neurofibrillary tangles aggregated by tau hyperphosphorylation are one of the important pathological features of AD. Objective To investigate potential effect of exogenous trivalent iron ions on neuronal activity in human neuroblastoma (SH-SY5Y) cells and tau hyperphosphorylation and aggregation. Methods SH-SY5Y cells were treated with ferric chloride (FeCl₃) at four concentrations (10, 100, 200, and 400 mg·L⁻¹). Cell survival rate was then detected by CCK8 assay. Intracellular iron content was determined prussian blue (Perl's) by iron staining after 24 h exposure to FeCl₃ at 10 or 200 mg·L⁻¹. Transfection of tau-P301L plasmid was conducted to construct an AD-like cell model for tau overexpression. The differences in the expression of the phosphorylated tau (p-tau) protein in SH-SY5Y cells and SH-SY5Y cells with tau overexpression were detected by Western blotting after 24 h exposure to FeCl₃ at 10 and 200 mg·L⁻¹. After dilution with phosphate buffered saline (PBS), FeCl₃, human tauR3, and FeCl₃ + tauR3 were incubated at 37℃, and the fluorescence intensity reflecting tau aggregation level was measured by thioflavin T(ThT) method at 12, 24, 36, 48, 60, 72, 84, and 96 h, respectively. Meanwhile, after 96 h coincubation of FeCl₃ and tauR3, the fibers formed by tau aggregation were observed under a transmission electron microscope (TEM). Results After 24 h of FeCl₃ exposure, the cell survival rate of SH-SY5Y cells among all groups was statistically different (F=8.63, P<0.01). The cell survival rates in the 200 and 400 mg·L⁻¹ groups were 80.1% and 68.7% of the control group, respectively (P<0.05). Compared with the control group, the nuclei of the 200 mg·L⁻¹ FeCl₃ group were mainly yellowish-brown after iron staining and the positive cell rate was up-regulated by 12.9% (P<0.01). After 24 h of FeCl₃ exposure , the p-tau (Ser396) protein expression was statistically different among all groups (F=11.6, P<0.01). Compared with the control group, the p-tau protein expression level of SH-SY5Y cells in the 200 mg·L⁻¹ group was up-regulated by 72.7% (P<0.01). After FeCl₃-treated SH-SY5Y cells with tau overexpression for 24 h, the p-tau (Ser396) protein expression was statistically different among all groups (F=27.8, P<0.01). Compared with the tau group, the p-tau (Ser396) protein expression level of SH-SY5Y cells in the tau + 200 mg·L⁻¹ group was up-regulated by 44.6% (P<0.05). Compared with the tauR3 group, the fluorescence intensities in the 84 and 96 h tauR3 + FeCl₃ groups were up-regulated by 49.9% and 53.7% (P<0.01) respectively. After 96 h of coincubation, compared with the tauR3 group, FeCl₃ + tauR3 aggravated tau aggregation and formed fiber deposition under TEM. Conclusion Exogenous trivalent iron ions may inhibit SH-SY5Y cell viability, promote the phosphorylation of tau in SH-SY5Y cells transfected with tau-P301L plasmid, and aggravate tauR3 aggregation and fiber production.

Oxalicine B ( 1) is an α-pyrone meroterpenoid with a unique bispirocyclic ring system derived from Penicillium oxalicum. The biosynthetic pathway of 15-deoxyoxalicine B ( 4) was preliminarily reported in Penicillium canescens, however, the genetic base and biochemical characterization of tailoring reactions for oxalicine B ( 1) has remained enigmatic. In this study, we characterized three oxygenases from the metabolic pathway of oxalicine B ( 1), including a cytochrome P450 hydroxylase OxaL, a hydroxylating Fe(II)/α-KG-dependent dioxygenase OxaK, and a multifunctional cytochrome P450 OxaB. Intriguingly, OxaK can catalyze various multicyclic intermediates or shunt products of oxalicines with impressive substrate promiscuity. OxaB was further proven via biochemical assays to have the ability to convert 15-hydroxdecaturin A ( 3) to 1 with a spiro-lactone core skeleton through oxidative rearrangement. We also solved the mystery of OxaL that controls C-15 hydroxylation. Chemical investigation of the wild-type strain and deletants enabled us to identify 10 metabolites including three new compounds, and the isolated compounds displayed potent anti-influenza A virus bioactivities exhibiting IC₅₀ values in the range of 4.0-19.9 μmol/L. Our studies have allowed us to propose a late-stage biosynthetic pathway for oxalicine B ( 1) and create downstream derivatizations of oxalicines by employing enzymatic strategies.

【Objective】 To analyze the related factors and countermeasures of adverse reactions to whole blood donation(ARBD) for medical student donors, so as to further reduce the incidence of ARBD. 【Methods】 The demographic data of medical/non-medical student donors and those suffered from ARBD from 2016 to 2018 were retrospectively analyzed, and the relationship between ARBD and age, gender, frequency of blood donation, blood volume, blood type, pulse, ALT, blood pressure, hemoglobin, etc. was statistically analyzed. 【Results】 The incidence of ARBD in all medical student donors from 2016 to 2018 was 1.16%, lower than that of non-medical students (1.51%). The ARBD rate(2.30%) of senior medical students (> 20 years old) was significantly lower than that of non-medical students (3.93%) and higher than that of junior medical students (≤20 years old)(0.70%). The ARBD rate of novel medical student donors was 1.27%, lower than that of novel non-medical students (2.12%) (P<0.05). Male medical students(1.68%) were more likely to develop ARBD than females(0.78%), donations within 200 mL(55%) than 300mL(0.26%) and 400mL(0), Hb<120 g/L(13.04%) than Hb≥120 g / L( 1.10% ), and blood type A(1.70%) than type O (0.88%) (P<0.05). Logistic regression analysis showed that blood volume and blood type were related factors. ARBD was more likely to occur in Type A blood than type O, and was more likely to occur when blood volume was lower. ARBD occurred frequently during phlebotomy, due to mental stress(75%) and hunger(8.92%)(P<0.05), while 96.43% of ARBD could recover within 10 minutes. 【Conclusion】 Novel, male, older than 20 years, Hb<120 g / L, blood type A and donation unit ≤200 mL were main risks for ARBD in medical student donors. Popularizing the knowledge of voluntary blood donation and strengthening pre-donation communication are important measures to prevent ARBD.

Objective To investigate the clinical treatment and outcomes of severe community-acquired pneumonia (CAP) complicated with mediastinal emphysema after renal transplantation. Methods Clinical data of9 patients with severe CAP complicated with mediastinal emphysema after renal transplantation were retrospectively analyzed. The acute physiology and chronic health evaluationⅡ(APACHEⅡ) and oxygenation index were recorded when the patients were admitted to the intensive care unit (ICU). The complications of mediastinal emphysema and corresponding treatment were observed. The treatment course during the ICU, mortality rate in ICU, ICU stay time and hospital stay time were recorded. All patients underwent pathogenic examinations. Results The APACHEⅡ score of9 patients with severe CAP complicated with mediastinal emphysema after renal transplantation was 14 (8-21) scores and the oxygenation index was 150 (133-189) mmHg. Among 9 patients, 3 cases were infected by bacteria alone, 3 cases were infected by bacterial infection combined with viral infection, 1 case was infected by mycobacterium tuberculosis complicated with other bacterial infection and 1 case was viral infection. No pathogenic evidence was detected in the remaining 1 patient. Mediastinal emphysema complicated with subcutaneous emphysema occurred in 7 cases and pneumothorax occurred in 6 cases. Treatment methods included anti-infection, modified immunosuppressive program, mediastinal drainage, thoracic closed drainage, subcutaneous incision and extracorporeal membrane oxygenation (ECMO) treatment. Six patients received invasive mechanical ventilation (IMV), 2 received non-invasive positive pressure ventilation (NIV) and 1 received high-flow nasal oxygen cannula (HFNC). Among 9 patients, the mortality rate in ICU was 6/9, the remaining 3 patients were recovered and discharged, the ICU stay time was 26 (17-40) d, and the total hospital stay time was 27-61 d. Conclusions Mediastinal emphysema is a serious complication of patients presenting with severe CAP after renal transplantation with a high mortality rate. For these patients, imaging evaluation, timely drainage and full sedation should be strengthened, and ECMO treatment should be delivered when necessary.

Objective To investigate the risk factors of perioperative complications of laparoscopic radical distal gastrectomy and influence of body shape on the short-term therapeutic effects.Methods The retrospective case-control study was conducted.The clinicopathological data of 506 patients (328 males and 178 females,average age 60 years with the range of 24-85 years) who underwent laparoscopic radical distal gastrectomy+D2 lymph nodes dissection in the 8 clinical centers between March 2016 and November 2018 were collected,including 143 in the First Affiliated Hospital of Xiamen University,66 in the Affiliated Hospital of Qinghai University,66 in the Second Affiliated Hospital of Wenzhou Medical University,64 in the Zhongshan Hospital of Xiamen University,54 in the Affiliated Hangzhou First people's Hospital of Zhejiang University School of Medicine,48 in the Zhangzhou Affiliated Hospital of Fujian Medical University,35 in the Affiliated Quanzhou First Hospital of Fujian Medical University,30 in the Second Affiliated Hospital of Xiamen Medical College.The maximum thickness of subcutaneous fat at the level of umbilicus (USCF),the maximum vertical distance between the anterior abdominal skin and the back skin at the level of the umbilicus (UAPD),the maximum horizontal distance between the anterior abdominal skin and the back skin at the level of the umbilicus (UTD),the maximum verticaldistance between the anterior abdominal skin and the back skin at the level of the xiphoid bone (XAPD),the maximum horizontal distance between the.anterior abdominal skin and the back skin at the level of the xiphoid bone (XTD),the distance between the anterior abdominal skin and the root of celiac artery (CAD) and the maximum horizontal distance at a right angle to CAD (CATD) were measured using preoperative imaging examinations.Observation indicators:(1) intraoperative and postoperative situations;(2) follow-up situations;(3) risk factors analysis of perioperative complications;(4) influence of body shape related indexes on intraoperative situations and postoperative recovery:① Pearson univariate correlation analysis,② liner regression model analysis.Followup using outpatient examination and telephone interview was performed to detect the postoperative survival and tumor recurrence or metastasis up to December 2018.Measurement data with normal distribution were represented as Mean±SD.Measurement data with skewed distribution were described as M (range).Comparisons of count data were analyzed using the chi-square test.Comparisons of ordinal data were analyzed by Mann-Whitney U nonparametric test.Risk factors of perioperative complications of laparoscopic distal gastrectomy were analyzed by Logistic regression model.Influence of body shape related indexes on intraoperative situations and postoperative recovery was analyzed by Pearson univariate correlation analysis and liner regression model.Results (1) Intraoperative and postoperative situations:all the 506 patients underwent successful laparoscopic distal gastrectomy,including 103 with Billroth Ⅰ anastomosis,140 with Billroth Ⅱ anastomosis,201 with Billroth Ⅱ + Braun anastomosis,62 with Roux-en-Y anastomosis.The operation time,volume of intraoperative blood loss,number of lymph nodes dissected,time to postoperative anal exsufflation,time for initial fluid diet intake,time for initial semi-fluid diet intake and duration of postoperative hospital stay were (233±44)minutes,(102±86)mL,34±13,(3.6±1.5)days,(5.8±3.3)days,(8.3±3.8)days,(12.2±5.7)days respectively in the 506 patients.Of 506 patients,196 were defined as pathological stage Ⅰ,122 were defined as pathological stage Ⅱ and 188 were defined as pathological stage Ⅲ postoperatively.Of 506 patients,93 had 106 times of perioperative complications,including 33 times of pulmonary and upper respiratory infection,12 times of incisional infection,11 times of anastomotic leakage,11 times of abdominal infection,8 times of intestinal obstruction,8 times of gastroplegia,6 times of abdominal hemorrhage,5 times of bacteremia,3 times of anastomotic hemorrhage,3 times of lymph fluid leakage,2 times of pancreatic leakage,1 time of urinary infection,1 time of anatomotic stenosis,1 time of deep venous thrombosis and 1 time of pulmonary embolism;the same patient can merge multiple complications.Eleven patients were in the Clavien-Dindo classification ≥ Ⅲ.(2) Follow-up situations:465 of 506 patients were followed up for 1-32 months with a median time of 12 months.During the follow-up,451 had postoperative survival and 38 had tumor recurrence or metastasis.(3) Risk factors analysis of perioperative complications.① Results of univariate analysis showed that age,body mass index (BMI),preoperative hemoglobin,preoperative serum albumin and XAPD were related factors affecting perioperative complications of laparoscopic distal gastrectomy (x2 =10.289,7.427,5.269,5.481,4.285,P＜ 0.05).② Results of multivariate analysis showed that age,BMI,preoperative serum albumin were independent related factors affecting perioperative complications of laparoscopic distal gastrectomy (odds ratio =1.033,1.118,0.937,95％ interval confidence:1.011-1.057,1.025-1.219,0.887-0.990,P＜0.05).(4) Influence of body shape related indexes on intraoperative situations and postoperative recovery.① Results of Pearson univariate correlation analysis showed correlations between UAPD,XAPD,CAD,CATD and volume of intraoperative blood loss (r=0.107,0.169,0.179,0.106,P＜0.05),between UAPD,XAPD,CAD and the number of lymph nodes dissected (r=-0.137,-0.143,-0.173,P＜0.05),between USCF,XAPD and time to postoperative anal exsufflation (r =0.122,0.109,P＜0.05),between USCF,XAPD,CAD and time for initial fluid diet intake (r=0.132,0.108,0.132,P＜0.05),between USCF,XAPD and duration of postoperative hospital stay (r=0.116,0.100,P＜0.05).② Results of liner regression model analysis showed a positive correlation between CAD and volume of intraoperative blood loss (r =6.776),a negative correlation between CAD and the number of lymph nodes dissected (r =-0.841),with statistically significant differences (t =2.410,-1.992,P＜ 0.05);a positive correlation between USCF and time to postoperative anal exsufflation (r=0.170),between USCF and time for initial fluid diet intake (r=0.365),between USCF and duration of postoperative hospital stay (r=0.636) respectively,with statisticallysignificant differences (t =2.188,1.981,2.107,P＜ 0.05).Conclusions Abdominal shape can influence intraoperative situations and postoperative recovery of laparoscopic distal gastrectomy,but cannot increase risks ofperioperative complications.Age,BMI and preoperative serum albumin are independent related factors affecting perioperative complications of laparoscopic distal gastrectomy.

Objective To compare the effect of nutritional support with and without tube feeding on the incidence of adverse reactions in radiotherapy for esophageal cancer.Methods A total of 120 esophageal cancer patients with high-risk factors receiving radiotherapy were selected and randomly assigned into the tube feeding (TF,n=60) and non-tube feeding groups (NTF,n=60) according to the random number method.Nutritional interventions were performed during radiotherapy in both groups.The incidence of esophagitis and myelosuppressioa,aulmonary infectioa,autritional status and the completion of radiotherapy were observed and statistically compared between TF and NTF groups.Results In the TF groua,ahe incidence of ≥ grade 2 esophagitis was lower than that in the NTF group.The incidence of grade 3 esophagitis significantly differed between two groups (P＜ 0.05).The incidence of grade 1-2 myelosuppression did not differ between two groupa,ahereas the incidence of grade 3 myelosuppression in the TF group was significantly lower than that in the NTF group (P＜0.05).In the TF groua,ahe incidence of pulmonary infection was remarkably lower than that in the NTF group (P＜0.05).The changes of BMI and prealbumin in the TF group were better than those in the NTF group (both P＜0.05).One patient in the NTF group failed to complete the radiotherapy due to grade Ⅳ esophagitia,and 5 cases in the NTF group (P＜ 0.05).In the TF groua,ahe length of hospital stay was significantly shortened by 6.2 d on average (P＜ 0.05).Conclusions During radiotherapy for esophageal cancer patients with high-risk factora,autritional support with tube feeding can effectively reduce the incidence of adverse reactiona,amprove the completion rate of treatmena,and shorten the average length of hospital stay.

Objective To investigate the application value of ultrasound-guided fine-needle aspiration cytology of lymph nodes in the pre-radiotherapy evaluation of superficial lymph nodes metastases in patients with lung cancer and esophageal cancer. Methods A total of 115 patients with lung cancer and esophageal cancer prepared for thoracic radiotherapy from February 2017 to September 2018 in Cancer Hospital of Huanxing Chaoyang District Beijing were retrospectively analyzed. Ultrasound-guided fine-needle aspiration cytology examination was performed in 166 lymph nodes. Puncture tissues were prepared for cytology production. Then cytological specialist read the film to evaluate if the cancer cells metastasis were present after conventional papanicolaou staining. The effects of short diameter of lymph nodes, blood flow signal and tumor characteristics of patients on the results of cytological examination were analyzed. Results The ultrasound results showed the median short diameter of lymph nodes was 0.6 cm (0.2-3.5 cm), and 25 (15.1％) lymph nodes had blood flow signals, 50 (30.1％) lymph nodes had positive results of puncture tissues cytology. The positive rate of puncture tissues cytology was 10.0％(4/40), 21.6％(21/97) and 86.2％(25/29) in the shortdiameter of lymph nodes <0.5 cm group, ≥0.5 cm and <1 cm group, and ≥1 cm group, respectively (P<0.01). Cytology positive rate of lymph nodes with or without blood flow signal detected by ultrasound was 48.0％ (12/25) and 27.0％ (38/141), and there was a statistical difference (P = 0.034). Location of primary tumor, T stage and chemotherapy history had no significant influence on the cytological results in patients with lung cancer (all P> 0.05). Pathological types had a significant influence on cytological results (χ2= 8.050, P= 0.045). Lymph node metastasis of the upper mediastinum was a risk factor for lymph node metastasis in lower neck and supraclavicular region (χ2= 9.699, P= 0.002). Location of primary tumor, T stage and chemotherapy history had no significant influence on cytological results in patients with esophageal cancer (all P> 0.05). Conclusions Ultrasound-guided fine-needle aspiration cytology is safe and efficient. It can be used to evaluate the metastasis status of superficial lymph nodes in pre-radiotherapy patients with lung cancer and esophageal cancer.