BACKGROUND:Socket-shield technique can effectively maintain labial soft and hard tissues,but the incidence of postoperative complications such as exposure and displacement of root shield is relatively high.It is speculated that the root shield may be exposed and displaced due to excessive load after long-term function of dental implants. OBJECTIVE:Through three-dimensional finite element analysis,we aim to study the influence of varying root shield thicknesses on the stress distribution,equivalent stress peaks,and displacement in the root shield,periodontal ligaments,implant,and surrounding alveolar bone under normal occlusal loading.We also attempt to analyze the correlation between the thickness of the root shield and occurrence of mechanical events such as root shield exposure,displacement,and fracture. METHODS:Cone-beam CT data of a patient who met the indication standard of socket-shield technique for maxillary central incisor were retrieved from database.Reverse engineering techniques were used to build models of the maxillary bone and root shield,while forward engineering was used to create models for the implant components based on their parameters.Models depicting various root shield thicknesses(0.5,1.0,1.5,and 2.0 mm)were created using Solidworks 2022 software.ANSYS Workbench 2021 software was then used to simulate and analyze the effects of varying root shield thicknesses on stress distribution,equivalent stress peaks,and displacement of the root shields,periodontal ligaments,implants,and surrounding alveolar bone under normal occlusion. RESULTS AND CONCLUSION:(1)In all root shield models,the stress was concentrated on the palatal cervical side,both sides of the edges and the lower edge of the labial side.As the thickness of the root shield increased,the equivalent stress peak and displacement showed a decreasing trend.The 0.5 mm thickness model produced a stress concentration of 176.20 MPa,which exceeded the yield strength(150 MPa)of tooth tissue.(2)The periodontal ligament stress in each group was concentrated in the neck margin and upper region.With the increase of root shield thickness,the equivalent stress peak and displacement of periodontal ligament showed a decreasing trend.(3)Implant stress in all models was concentrated in the neck of the implant and the joint of the implant-repair abutment,and the labial side was more concentrated than the palatal side.With the increase of root shield thickness,the equivalent stress peak of the implant in the model showed an increasing trend.(4)In each group of models,stress of cortical bone concentrated around the neck of the implant and the periphery of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the equivalent stress peak around the root shield decreased;the peak value of the equivalent stress of the bone around the neck of the implant showed an increasing trend.In the model,the stress of cancellous bone was mainly concentrated around the neck of the lip of the implant,the top of the thread,the root tip and the lower margin of the root shield,and the labial side was more concentrated than the palatal side.With the increase of the thickness of the root shield,the peak value of the equivalent stress of the bone around the root shield in the model showed a decreasing trend.The minimum principal stress of cortical bone in each group of models was concentrated around the neck of the implant,exhibiting a fan-shaped distribution.As the thickness of the root shield increased,the minimum principal stress of cortical bone showed an increasing trend.(5)These results indicate that different thicknesses of the root shield have different biomechanical effects.The root shield with a thickness of 0.5 mm is easy to fracture.For patients with sufficient bone width,the root shield with a thickness of 2.0 mm is an option to reduce the risk of complications such as root shield exposure,fracture,and displacement.Meanwhile,it should be taken into account to protect the periodontal ligament in the preparation process,and rounding treatments ought to be carried out on both sides and the lower edge of the root shield.

Objective To investigate CT features of Chlamydia psittaci(C.psittaci)pneumonia patients.Methods Ten patients with C.psittaci pneumonia were collected retrospectively based on macro gene second-generation sequencing(mNGS).The radiological manifestations of the disease were analyzed.Results Seven patients(70%)had contact history with birds(poultry)or their feces.Chest CT on the day of admission was mainly mass patchy consolidation,all of which were located in single lung,involving 8 cases(80%)with one lobe and 2 cases(20%)with two lobes.All of them were accompanied by air bronchogram,9 cases(90%)with ground glass shadow and 8 cases(80%)with interstitial changes.One case(10%)showed a reversed halo sign,and 1 case(10%)showed fan-shaped consolidation.Nine cases(90%)showed progress with increased fusion or new lesions within nine days.Conclusion CT findings of C.psittaci pneumonia have certain characteristics,and combining with history of contacting birds(poultry)can suggest diagnosis.

Objective To investigate the fluctuations in the population density of Aedes albopictus and changes in the population density of Ae. albopictus in different geographical areas and different breeding habitats in Guangdong Province from 2018 to 2023, so as to provide insights into prevention and control of mosquito-borne infectious diseases in the province. Methods Ae. albopictus surveillance sites were assigned in 1 609 townships (streets) from 121 districts (counties) of 21 cities in Guangdong Province during the period between March and November from 2018 to 2023. The surveillance of the population density of Ae. albopictus was performed once a month in each surveillance site, and once a month in specific settings in cities where dengue were highly prevalent in Guangdong Province from December to February of the next year during the period from 2018 through 2023. Four streets (villages) were selected in each surveillance site according to the geographic orientation, and mosquito ovitraps were assigned in gardens, rooftops or public green belts at residential areas, parks, hospitals and construction sites. All mosquito ovitraps were collected, and the mosquito ovitrap index (MOI) was calculated. The population density of Ae. albopictus was classified into four grades in each surveillance site according to MOI, including no risk, low risk, medium risk and high risk. The risk classification of the Ae. albopictus density was analyzed in each surveillance site each year from 2018 to 2023, and the population density of Ae. albopictus was analyzed at different months and in different geographical areas and breeding habitats. Results A total of 118 241 Ae. albopictus surveillance sites were assigned in 21 cities of Guangdong Province from 2018 to 2023, and there were 68.26% of the surveillance sites with the population density of Ae. albopictus that met the requirements for dengue prevention and control, among which low, medium and high risk surveillance sites accounted for 23.61%, 6.67% and 1.47%. The risk classification of the Ae. albopictus density increased rapidly in Guangdong Province since April to May each year from 2018 to 2023, and then gradually reduced since September to October, with the peak during the period between May and July. The mean MOI was 4.21 at each surveillance site in Guangdong Province during the period from 2018 to 2023, with 4.69, 4.80, 4.38, 3.82, 3.38, and 4.33 from 2018 to 2023, respectively. The MOI was 4.35, 4.43, 3.53 and 3.58 in the Pearl River Delta region, and eastern, western, and northern Guangdong Province, respectively, and was 4.18, 5.44, 4.75, 3.24, 4.27 and 3.70 in residential areas, parks, construction sites, hospitals, waste collection stations, and other breeding habitats, respectively. Conclusions The population density of adult Ae. albopictus peaked in Guangdong Province during the period between May and July from 2018 to 2023, with a high density of Ae. albopictus in the Pearl River Delta region and eastern Guangdong Province. Targeted Ae. albopictus control measures are recommended to be implemented prior to the peak of the Ae. albopictus population density to reduce the development of mosquito-borne infectious diseases.

BACKGROUND:Bone tissue remodeling is closely related to stress loading.Currently,there are few studies or guidelines on the relationship between bone and occlusal adjustment of implant prostheses and there is also a lack of scientific evidence. OBJECTIVE:To investigate the effects of different implant occlusal gaps on stress distribution,stress peak and displacement at the implant-bone interface under Ⅰ-Ⅳ bone conditions by a finite element method. METHODS:After scanning the equal-scale tooth model with an optical scanner,equal-scale models of the upper right first molar Straumann 4.8×8 mm BL RC implant and its related components was constructed using Solidworks 2022.Then,using Mimics,Geomagic,and Solidworks software,the maxillary and mandibular bone models of class Ⅰ-Ⅳ bones were established based on the bone classification proposed by ZARB and LEKHOLM in the literature,and the NORTON and TRISI bone density classification method.The models were assembled with the occlusal gaps of 0,20,40,60,80,and 100 μm for the restorations,and an additional set of homogeneous models without density ratio settings was constructed for comparison.After the above models were imported into Hypermesh for meshing,the material assignment,boundary constraints and parameter setting were performed for the finite element analysis.Finally,250 N was used as the loading force to simulate the maxillary and mandibular stress conditions.Stress distribution,peak stress and displacement of the implant-bone interface in each group of models were analyzed and compared. RESULTS AND CONCLUSION:Under the same loading conditions,the stresses in the implant restorations were evenly distributed with the occlusal contact points.When the occlusal gap reached 80 and 100 μm,stress interruptions occurred in the implant crowns under class Ⅰ bone and class Ⅱ,Ⅲ and Ⅳ bones,respectively.The displacement of the implant-bone interface was mainly concentrated in the cortical bone region around the implant and transmitted down the long axis of the implant to the cancellous bone region at the bottom.With the changes of class Ⅰ-Ⅳ jaw bones,the displacement and Von Mises stress in the cortical bone region increased in all groups,and were greater than those in the cancellous bone region.The Von Mises stress in the cancellous bone region was similar to that in the cortical bone region except that it showed a downward trend from class Ⅱ bone.However,when the occlusal gap increased,the stress and displacement peak values in the cortical bone and the cancellous bone showed a decreasing trend.The stress of the implant-bone interface was between 20 MPa and 60 MPa when the occlusal gap was 0-40 μm for class Ⅱ-Ⅳ bones and 60 μm for class Ⅳ bone,and the stress of the other groups was less than 20 MPa.The Von Mises stress was mainly concentrated in the neck of the implant,and the peak value of von Mises stress in class Ⅱ-Ⅳ bones with the occlusal gap of 20 μm was higher than that(144.10 MPa)in class Ⅰ bone with the occlusal gap of 0 μm.In the homogeneous model with different elastic moduli,the distribution of stress and displacement was more uniform than that in the heterogeneous model and the occlusal space should increase with the decrease of jaw bone density in clinical practice.To conclude,from the perspective of biomechanics,the alveolar bone should be taken into account in the occlusal adjustment of implant denture.An occlusal gap of 20-40 μm between a single dental implant and a natural tooth in the opposite jaw is a relatively suitable solution for occlusal adjustment under different bone conditions.However,due to the particularity of finite element analysis method,it needs to be further studied in combination with clinical practice.

Rheumatoid arthritis (RA) is an autoimmune disease and is mainly characterized by abnormal proliferation of fibroblast-like synoviocytes (FLS). The up-regulated cellular membrane expression of G protein coupled receptor kinase 2 (GRK2) of FLS plays a critical role in RA progression, the increase of GRK2 translocation activity promotes dysfunctional prostaglandin E4 receptor (EP4) signaling and FLS abnormal proliferation. Recently, although our group found that paeoniflorin-6'-

Objective:To summarize clinical characteristics of and treatment experience with patients with critical illnesses in a dermatological ward.Methods:All patients with serious or life-threatening conditions, who were hospitalized at the dermatological ward of the Second Xiangya Hospital of Central South University from July 9, 2011 to December 31, 2020, were collected, and their clinical data were retrospectively analyzed. Demographic characteristics, disease types and proportions, main complications, causes of serious or life-threatening conditions, important treatment measures and outcomes were summarized, and causes of death were also analyzed and discussed.Results:A total of 1 057 patients with critical illnesses were collected, with a male-to-female ratio of 1∶1.11, and 64.81% of them aged 18 to 65 years. The types of diseases mainly included drug eruptions (332 cases) , connective tissue diseases (226 cases) , bullous skin diseases (104 cases) , psoriasis (57 cases) , erythroderma (45 cases) , infectious skin diseases (67 cases) , etc. Among them, psoriasis (39 cases) and erythroderma (32 cases) mostly occurred in males, and connective tissue diseases (168 cases) mostly occurred in females. Common complications mainly involved infections, important organ damage or dysfunction, hypoalbuminemia, and fluid, electrolyte and acid-base imbalances. A total of 94 patients were diagnosed with life-threatening conditions, which were found to be mainly caused by primary skin diseases, hematologic abnormalities, respiratory failure, nervous system abnormalities, renal failure, sepsis, fluid, electrolyte and acid-base imbalances, etc. During the management of critical illnesses, 43 patients were treated with high-dose glucocorticoid pulse therapy, 264 were treated with gamma-globulin pulse therapy, 355 were transfused with other blood products, and 34 received special therapies such as hemoperfusion/immunoadsorption therapy, plasma exchange, dialysis, artificial liver support therapy; 42 patients were transferred to the intensive care unit (ICU) , 12 were transferred to the department of surgery for operations, and 12 were transferred to the department of obstetrics and gynecology for delivery or induction of labor. After treatment, 989 patients (93.57%) achieved improvement and were discharged. A total of 14 patients (1.32%) died, of whom 7 died of secondary sepsis, 2 died of severe pulmonary infections, 2 died of asphyxia caused by respiratory mucosa shedding-induced airway obstruction, the other 3 died of gastrointestinal hemorrhage, cerebral hemorrhage and neuropsychiatric systemic lupus erythematosus, respectively.Conclusions:Critical cases in the dermatological ward mainly suffered from serious skin diseases such as severe drug eruptions, connective tissue diseases and bullous skin diseases, as well as complications such as severe underlying diseases, severe organ dysfunction, sepsis or severe fluid, electrolyte and acid-base imbalances. In terms of treatment, it is of critical significance to make a clear diagnosis and assess the severity of disease as early as possible, monitor and prevent possible complications, and to consult with specialists in relevant disciplines in time.

Objective:To understand the current practice of preoperative bowel preparation in elective colorectal surgery in China.Methods:A cross-sectional questionnaire survey was conducted through wechat. The content of the questionnaire survey included professional title of the participants, the hospital class, dietary preparation and protocol, oral laxatives and specific types, oral antibiotics, gastric intubation, and mechanical enema before elective colorectal surgery. A stratified analysis based on hospital class was conducted to understand their current practice of preoperative bowel preparation in elective colorectal surgery.Result:A total of 600 questionnaires were issued, and 516 (86.00%) questionnaires of participants from different hospitals, engaged in colorectal surgery or general surgeons were recovered, of which 366 were from tertiary hospitals (70.93%) and 150 from secondary hospitals (29.07%). For diet preparation, the proportions of right hemicolic, left hemicolic and rectal surgery were 81.59% (421/516), 84.88% (438/516) and 84.88% (438/516) respectively. The average time of preoperative dietary preparation was 2.03 days. The study showed that 85.85% (443/516) of surgeons chose oral laxatives for bowel preparation in all colorectal surgery, while only 4.26% (22/516) of surgeons did not choose oral laxatives. For mechanical enema, the proportions of right hemicolic, left hemicolic and rectal surgery were 19.19% (99/516), 30.04% (155/516) and 32.75% (169/516) respectively. Preoperative oral antibiotics was used by 34.69% (179/516) of the respondents. 94.38% (487/516) of participants were satisfied with bowel preparation, and 55.43% (286/516) of participants believed that preoperative bowel preparation was well tolerated. In terms of preoperative oral laxatives, there was no statistically significant difference between different levels of hospitals [secondary hospitals vs. tertiary hospitals: 90.00% (135/150) vs. 84.15% (308/366), χ 2=2.995, P=0.084]. Compared with the tertiary hospitals, the surgeons in the secondary hospitals accounted for higher proportions in diet preparation [87.33% (131/150) vs. 76.78% (281/366), χ 2=7.369, P=0.007], gastric intubation [54.00% (81/150) vs. 36.33% (133/366), χ 2=13.672, P<0.001], preoperative oral antibiotics [58.67% (88/150) vs. 24.86% (91/366), χ 2=12.259, P<0.001] and enema [28.67% (43/150) vs. 15.30% (56/366), χ 2=53.661, P<0.001]. Conclusion:Although the preoperative bowel preparation practice in elective colorectal surgery for most of surgeons in China is basically the same as the current international protocol, the proportions of mechanical enema and gastric intubation before surgery are still relatively high.

Objective:To understand the current practice of preoperative bowel preparation in elective colorectal surgery in China.Methods:A cross-sectional questionnaire survey was conducted through wechat. The content of the questionnaire survey included professional title of the participants, the hospital class, dietary preparation and protocol, oral laxatives and specific types, oral antibiotics, gastric intubation, and mechanical enema before elective colorectal surgery. A stratified analysis based on hospital class was conducted to understand their current practice of preoperative bowel preparation in elective colorectal surgery.Result:A total of 600 questionnaires were issued, and 516 (86.00%) questionnaires of participants from different hospitals, engaged in colorectal surgery or general surgeons were recovered, of which 366 were from tertiary hospitals (70.93%) and 150 from secondary hospitals (29.07%). For diet preparation, the proportions of right hemicolic, left hemicolic and rectal surgery were 81.59% (421/516), 84.88% (438/516) and 84.88% (438/516) respectively. The average time of preoperative dietary preparation was 2.03 days. The study showed that 85.85% (443/516) of surgeons chose oral laxatives for bowel preparation in all colorectal surgery, while only 4.26% (22/516) of surgeons did not choose oral laxatives. For mechanical enema, the proportions of right hemicolic, left hemicolic and rectal surgery were 19.19% (99/516), 30.04% (155/516) and 32.75% (169/516) respectively. Preoperative oral antibiotics was used by 34.69% (179/516) of the respondents. 94.38% (487/516) of participants were satisfied with bowel preparation, and 55.43% (286/516) of participants believed that preoperative bowel preparation was well tolerated. In terms of preoperative oral laxatives, there was no statistically significant difference between different levels of hospitals [secondary hospitals vs. tertiary hospitals: 90.00% (135/150) vs. 84.15% (308/366), χ 2=2.995, P=0.084]. Compared with the tertiary hospitals, the surgeons in the secondary hospitals accounted for higher proportions in diet preparation [87.33% (131/150) vs. 76.78% (281/366), χ 2=7.369, P=0.007], gastric intubation [54.00% (81/150) vs. 36.33% (133/366), χ 2=13.672, P<0.001], preoperative oral antibiotics [58.67% (88/150) vs. 24.86% (91/366), χ 2=12.259, P<0.001] and enema [28.67% (43/150) vs. 15.30% (56/366), χ 2=53.661, P<0.001]. Conclusion:Although the preoperative bowel preparation practice in elective colorectal surgery for most of surgeons in China is basically the same as the current international protocol, the proportions of mechanical enema and gastric intubation before surgery are still relatively high.

Objective To investigate the correlation between the expression of (epidermal growth factor receptor-2,HER-2) and clinicopathological features and survival of colorectal cancer.Methods From Jan 2005 to Dec 2015,all colorectal cancer cases were enrolled that the expression levels of HER-2 were detected in Guangdong Provincial People's Hospital.Clinicopathological features of the tumors and survival of the patients were analyzed.Results A total of 1 463 cases were collected in 10 years,including 711 cases (48.6％) of HER-2 (-),470 cases (32.1％) of HER-2 (+),249 cases (17％) of HER-2 (+ +),and 33 cases (2.3％) of HER-2 (+ + +).Correlation analysis shows that the expression levels of HER-2 were significantly correlated with tumor differentiation and the depth of tumor invasion(T stage),but not correlated with gender,age,tumor location,N stage,M stage,TNM stage and overall survival,and disease-free survival.Conclusion The expression of HER-2 may be related to tumor differentiation and growth infiltration,but it cannot be used as a predictor of prognosis in patients with colorectal cancer.

Objective: To investigate the value and feasibility of C reactive protein (CRP) in predicting postoperative anastomotic leakage in rectal cancer patients with enhanced recovery after surgery (ERAS) for safer implementation of this ERAS. Methods: A cohort study on serum CRP of 455 rectal cancer patients undergoing laparoscopic radical resection according to the ERAS procedure at Gastrointestinal Unit of General Surgery Department, Guangdong General Hospital from August 2014 to June 2017 was retrospectively carried out. The serum CRP level was measured before operation and at postoperative days 1-7, and the serum CRP level of the groups with and without anastomotic leakage was compared to analyze its prediction for anastomotic leakage. Diagnostic standard of anastomotic leakage was based on the definition of postoperative anastomotic leakage in rectal cancer from International Study Group of Rectal Cancer (ISREC) : (1) Postoperative localized or diffuse peritonitis occurred, or fecal liquid was found from the abdominal drainage tube; (2) When anastomotic leakage was uncertain, peritoneal or pelvic computed tomography scan should be used to confirm. Results: All the 455 patients underwent surgery successfully, and 41 patients (9.0%) had anastomotic leakage postoperatively. Patients with anastomotic leakage were diagnosed (4.0 ± 2.0) days postoperatively, of whom 8 cases (19.5%) were diagnosed more than 5 days postoperatively. Serum CRP levels in patients with anastomotic leakage continued to increase within 1-4 days postoperatively[ (50.04 ± 27.98) mg/L to (122.75 ± 52.98) mg/L]and decreased 5 days postoperatively[ (92.02 ± 58.26) mg/L], both were higher than those of non-anastomotic leakage group, and the difference was statistically significant (all P < 0.05, except postoperative day 2) . The serum CRP level of non-anastomotic leakage group reached the peak on the second postoperative day[ (83.10 ± 37.45) mg/L] and decreased 3 days postoperatively[ (48.01 ± 27.59) mg/L]. The ROC curve was drawn with the anastomotic leakage as the state variable, and the CRP level as the detection variable. The area under the curve (AUC) at postoperative 1, 2, 4, 5, 6 and 7 days was 0.74, 0.58, 0.83, 0.82, 0.65, and 0.70, respectively. The maximum was at postoperative day 3[0.93 (95%CI: 0.86-0.99) ]. The Youden index was 0.72, and the threshold of CRP was 80.09 mg/L, as the cut-off point to predict anastomotic leakage, with sensitivity, specificity, and positive predictive value of 79.3%, 92.3%, and 74.2%, respectively. Conclusions Monitoring the postoperative serum CRP level can help predict the occurrence of anastomotic leakage after laparoscopic surgery for rectal cancer. When the serum CRP level is > 80.09 mg/L on the third postoperative day, the CRP level has the largest value in predicting postoperative anastomotic leakage, and the safety of ERAS has a certain clinical significance as well.