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.

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.

Objective To investigate the infection status and changing trend of hepatitis C virus(HCV)infection in hospitalized patients in medical institutions,and provide reference for formulating HCV infection prevention and control strategies.Methods HCV infection surveillance results from cross-sectional survey data reported to China Healthcare-associated Infection(HAI)Surveillance System in 2020 were summarized and analyzed,HCV positive was serum anti-HCV positive or HCV RNA positive,survey result was compared with the survey results from 2003.Results In 2020,1 071 368 inpatients in 1 573 hospitals were surveyed,738 535 of whom underwent HCV test,4 014 patients were infected with HCV,with a detection rate of 68.93％and a HCV positive rate of 0.54％.The positive rate of HCV in male and female patients were 0.60％and 0.48％,respectively,with a statistically sig-nificant difference(x2=47.18,P＜0.001).The HCV positive rate in the 50-＜60 age group was the highest(0.76％),followed by the 40-＜50 age group(0.71％).Difference among all age groups was statistically signifi-cant(x2=696.74,P＜0.001).In 2003,91 113 inpatients were surveyed.35 145 of whom underwent HCV test,resulting in a detection rate of 38.57％;775 patients were infected with HCV,with a positive rate of 2.21％.In 2020,HCV positive rates in hospitals of different scales were 0.46％-0.63％,with the highest in hospital with bed numbers ranging 600-899.Patients'HCV positive rates in hospitals of different scales was statistically signifi-cant(X2=35.34,P＜0.001).In 2020,12 provinces/municipalities had over 10 000 patients underwent HCV-rela-ted test,and HCV positive rates ranged 0.19％-0.81％,with the highest rate from Hainan Province.HCV posi-tive rates in different departments were 0.06％-0.82％,with the lowest positive rate in the department of pedia-trics and the highest in the department of internal medicine.In 2003 and 2020,HCV positive rates in the depart-ment of infectious diseases were the highest,being 7.95％and 3.48％,respectively.Followed by departments of orthopedics(7.72％),gastroenterology(3.77％),nephrology(3.57％)and general intensive care unit(ICU,3.10％)in 2003,as well as departments of gastroenterology(1.35％),nephrology(1.18％),endocrinology(0.91％),and general intensive care unit(ICU,0.79％)in 2020.Conclusion Compared with 2003,HCV positive rate decreased significantly in 2020.HCV infected patients were mainly from the department of infectious diseases,followed by departments of gastroenterology,nephrology and general ICU.HCV infection positive rate varies with gender,age,and region.

Hepatocellular carcinoma （HCC） is the sixth most common cancer in the world. In recent years， the clinical early diagnosis and treatment protocols of HCC have been improved， whereas the prognosis of patients is still not satisfactory， which is due to the fact that the mechanism of HCC development has not been fully elucidated. Therefore， it is of great significance to explore the molecular mechanisms and key regulatory links of hepatocellular carcinoma development to further improve the diagnosis and treatment of HCC in China. Epigenetics has become a research hotspot because of its reversibility and easy regulation. According to relevant studies， HCC involves the accumulation of multiple genetic and epigenetic changes during the initiation， promotion， and progression stages. HCC is categorized as infantile malnutrition with accumulation， hypochondriac pain， tympan ites， and abdominal mass in traditional Chinese medicine （TCM）. In the treatment of HCC， TCM with low toxicity， multi-targets， and multi-mechanisms can inhibit tumor growth， alleviate the clinical symptoms， and enhance the quality of life of the patients. Chinese medicines and their active ingredients exert anti-HCC effects through epigenetic regulation of DNA methylation， histone modification， and non-coding RNA. Abnormal gene expression due to epigenetic regulation disorders is involved in all stages of HCC development. There are few studies on epigenetic regulation in TCM treatment of HCC， and there is still much room for development in basic and clinical trials. This paper reviews the mechanism of epigenetic regulation in HCC and summarizes the experimental results of TCM research on the related mechanism， with a view to providing a theoretical basis for future research on the mechanism of HCC development and clinical diagnosis and treatment of hepatocellular carcinoma with TCM.

Chronic diseases bring significant changes to both the child and their parents. Compared to the child, the child's parents are more likely to perceive the child's vulnerability. Even though there is medical evidence to suggest that children with chronic diseases are in a stable state, parents still believe that their children are very vulnerable to disease, injury, or death, that is, parental perceptions of child vulnerability (PPCV). PPCV is commonly present in children with chronic diseases and can have a significant negative impact on both the child and their parents. This paper reviews the concept and evaluation tools of PPCV in children with chronic diseases, and focuses on the negative impact and intervention strategies of PPCV on children and their parents, so as to provide reference for the evaluation, prevention, and intervention of PPCV in children with chronic diseases.

Objective:To analyze the research hotspots on domestic and international chronic illness trajectory models (CITM) .Methods:Literature on CITM was retrieved from the Web of Science Core Collection and China National Knowledge Infrastructure. CiteSpace 6.2.R4 was used to analyze research institutions, authors, and keywords visually.Results:A total of 1 316 articles were obtained. The majority of the literature originated from foreign countries. Research hotspots on CITM included chronic diseases, anxiety, and quality of life. International studies focused on risk research, while domestic studies emphasized self-care, self-efficacy, and complications.Conclusions:Research on CITM in China is still in its infancy. Both domestic and international efforts need to enhance collaboration among institutions, authors, and disciplines to conduct in-depth research on CITM. Chronic illness, anxiety or depression, and quality of life are likely to become research hotspots in the field of CITM both domestically and internationally.

Objective To form the expert consensus on the limb management of patients with transvenous temporary cardiac pacing,standardize the limb management of patients with transvenous temporary cardiac pacing,and reduce complications related to the limb.Methods Using evidence-based methods,the evidence in this field was searched,evaluated and summarized,and relevant recommendations and research conclusions were extracted and classified by the level of evidence quality,and then the first draft of the consensus was formed.From December 2023 to January 2024,through 2 rounds of expert consultation and 4 rounds of expert meetings,the content was adjusted and the consensus was reached.Results Totally 16 experts participated in the consultation.The positive coefficient is 100%;the authoritative coefficient is 0.847 and 0.836;the average value of each index is more than＞3.8;the coefficient of variation is less than 0.21.The Kendall's harmony coefficient of the 2 rounds of expert consultation is 0.372 and 0.314,respectively,which were statistically significant.The consensus covers the preoperative,intraoperative and postoperative on limb management of patients with transvenous temporary cardiac pacing.Totally 11 themes were involved,including the preoperative preparation,position and catheter fixation in operation,position and catheter fixation in postoperative,activity,turn and transfer,duty shift on limb,nursing care after withdrawal of the catheter,prevention of deep vein thrombosis of the operative limb and prevent infection.Conclusion The consensus is highly scientific,and it is helpful to standardize the limb management of patients with transvenous temporary cardiac pacing.

Objective:To compare the efficacy of intraluminal microwave ablation with radiofrequency ablation in the treatment of varicose veins of the lower extremities.Methods:The clinical data of 520 patients (522 affected limbs) who underwent lower extremity varicose vein surgery at the Department of Vascular Surgery of the First Affiliated Hospital of Anhui Medical University from Jun 2021 to Sep 2022 were collected. Patients were divided into endovenous microwave ablation group (EMWA group, n = 201) and radiofrequency ablation group (RFA group, n = 321). Follow-up was performed at 1 week, 1 , 6 and 12 months after surgery. The primary efficacy endpoint was the occlusion rate of the treated segment vein, the primary safety endpoint was the incidence of surgery-related and/or device-related complications, and the secondary endpoints were the venous clinical severity score (VCSS) and chronic venous insufficiency quality of life questionnaire (CIVIQ) scores at follow-up. Results:The technique success rate and the occlusion rate of the affected segment vein was 100% in both groups evaluated one week after surgery; Six and 12 months after surgery, the occlusion rate in the RFA group was 98.9%, and that in the EMWA group was 99.3% and respectively 97.8%, 97.2% ,without statically significant difference.During the follow-up period, there were no cases of reoperation due to vein recanalization. no serious events such as deep vein thrombosis, pulmonary embolism or death occurred in either group. The incidence of adverse events (induration, ecchymosis, skin burn, incision infection, limb numbness, hematoma, thrombotic superficial phlebitis, endovenous heat induced thrombosis, etc.) in both groups was compared, and the difference was not statistically significant. VCSS and CIVIQ scores improved significantly in both groups at 1 ,6 and 12 months after treatment, and the difference was statistically significant(all P < 0.01). Conclusion:EMWA and RFA have the advantages of simple operation, good clinical efficacy and high degree of improvement in quality of life.

Objective:To establish a predictive model for preoperative diagnosis of benign and malignant phyllodes tumor of the breast(PTB). Methods:The clinicopathological data of 69 patients with benign PTB and 41 patients with malignant PTB(24 borderline and 17 malignant)who underwent multiple(≥2)preoperative ultrasound follow-ups in the Cancer Hospital of Harbin Medical University from January 2011 to December 2018 were retrospectively analyzed.The preoperative prediction models of benign and malignant PTB were constructed by using the influencing factors determined by multivariate logistic regression analysis.The receiver operating characteristic(ROC)curve was used to evaluate the efficiency of the prediction model.In addition,the clinicopathological data of 22 patients of benign PTB and 19 patients of malignant PTB(12 borderline and 7 malignant)admitted to the hospital from January 2019 to April 2022 were selected for external verification. Results:Logistic regression analysis showed that growth rate of tumor>2 mm/month and ultrasound BI-RADS category≥4b were independent predictors for the diagnosis of malignant PTB(OR:4.476,95％CI:1.673～11.975;OR:9.448,95％CI:3.149～28.345;P<0.01).The logistic regression equation:Logit(P)=-1.868+1.499×growth rate of tumor+2.246×ultrasound BI-RADS category.The AUC for the training cohort was 0.795(95％CI:0.699～0.890),the best cut-off value was 0.421,the corresponding sensitivity was 0.732,the specificity was 0.826,and the Jorden index was 0.558,P<0.001.The AUC for the the validation cohort was 0.772(95％CI:0.624～0.919),with the sensitivity of 0.526 and the specificity of 0.773,positive predictive value was 0.667 and negative predictive value was 0.654,P = 0.003.The AUC of the training cohort and the validation cohort were both>0.75,indicating that the model has certain predictive ability. Conclusion:The predictive model constructed by clinicopathological parameters can be used for preoperative diagnosis of benign PTB and malignant PTB,and provide a certain reference value for clinicians to select the appropriate surgical resection scope.

Objective:To evaluate the cosmetic outcomes of non-eyebag associated tear trough deformities (TTDs) using the transconjunctival lower eyelid blepharoplasty with release of the tear trough ligament (TTL) and orbital septum fat reposition.Methods:Non-eyebag associated TTDs patients who received the transconjunctival lower eyelid blepharoplasty with release of TTL and with reposition of the orbital septum fat flap internally fixed to the premaxillary-prezygomatic space were retrospectively reviewed at the Ninth People’s Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from September 2019 to April 2020. The "Hirmand" types of TTDs were classified preoperatively based on the digital photography. Tear trough rating scale (TTRS) introduced by Sadick was used to assess TTDs before and after surgeries based on depth of the trough, hyperpigmentation, prolapse of nasal fat pads/pockets, and lower eyelid skin rhytidosis. "Barton" grading system was used to evaluate demarcation of orbit-cheek junction area preoperatively and postoperatively. Ultimate surgical outcomes of TTDs were assessed by TTRS, Barton and patient self-assessment scores. Patients were followed up postoperatively and the complications were filed. Matched samples t-test (SPSS 20.0 software) was used for statistical analysis to compare TTRS scores pre- and post-surgery. Results:A total of 79 patients with bilateral TTDs were enrolled, including 24 men and 55 women. Their age ranged from 19 to 38 years old (average, 25.7 years old). Edema or congestion in conjunctiva presented in all patients within 3 days after surgery. Slight eyelid skin ecchymosis, lower eyelid edema or asymmetry was presented in 11 cases, and they all recovered in 1-2 weeks. No other complications occurred. The follow-up period ranged from 5 to 13 months (average, 8.5 months). TTRS scores between pre- and post-surgeries demonstrated no significant difference in Hirmand type Ⅰ ( P>0.05), but presenting significant difference both in Hirmand type Ⅱ and Hirmand type Ⅲ ( P<0.01). All cases (33) in Hirmand type Ⅰ graded as Barton 1 pre-surgery were improved to grade 0 post-surgery. There were 35 cases categorized as Hirmand type Ⅱ. Among them, 7 (20%), 25 (71.4%) and 3 cases (8.6%) were graded as Barton 1, 2 and 3 pre-surgery, respectively. Postoperatively, they were improved to Barton 0 (30 cases, 85.7%) and 1 (5 cases, 14.3%), accordingly. There were 11 cases categorized as Hirmand type Ⅲ, which included 6 cases graded as Barton 2 and 5 cases graded as Barton 3. After surgery, they were improved to Barton 0 (2 cases, 18.2%), Barton 1 (5 cases, 45.5%) and Barton 2(4 cases, 26.3%). As to overall cosmetic satisfaction, 78.5% (62/79), 17.7% (14/79) and 3.8% (3/79) were self-assessed as good, moderate and poor by the patients, respectively. Conclusions:Transconjunctival lower eyelid blepharoplasty with release of tear trough ligament and fat reposition can achieve satisfactory lower eyelid rejuvenation in tear trough deformities not associated with eyebags.