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 isolate the Japanese encephalitis virus carried by Culex tritaeniorhynchus in Dongchuan District of Yunnan Province and analyze its molecular characteristics, so as to provide insights into the prevention and control of Japanese encephalitis in Yunnan Province. Methods Mosquito specimens were collected using mosquito-trapping lamps from pig farms in Batang Village and Xiaoxin Village, Dongchuan District, Kunming City, Yunnan Province in July 2016, and the mosquito species was identified according to the mosquito morphology. Then, 60 to 100 mosquitoes of each species served as a group and were ground. Baby hamster kidney-21 (BHK-21) cells and Aedes albopictus clone C6/36 cells were used for virus isolation, and positive isolates were identified using flavivirus primers. The positive isolates were amplified using reverse transcription polymerase chain reaction (RT-PCR) assay with 15 pairs of specific primers covering the full length of the genotype I Japanese encephalitis virus, and DNA sequence assembly was performed using the software SeqMan in the DNASTAR package. The obtained sequences were aligned with the complete sequences of 38 Japanese encephalitis virus downloaded from the GenBank with the software MegAlign, and the nucleotide and amino acid homology analyses of the obtained sequences were performed. The difference in amino acid sites was analyzed with the software GeneDoc, and phylogenetic trees were created based on the sequences of the coding region and E protein of the isolated Japanese encephalitis virus with the software Mega X. In addition, the secondary and tertiary structures of the E protein of the Japanese encephalitis virus were predicted using the online tool SOPMA and the software Swiss-Model. Results A total of 5 820 mosquitoes were collected and 3 843 Cx. tritaeniorhynchus (66.03%) were identified according to the mosquito morphology. A positive virus isolate, termed YNDC55-33, was isolated from Cx. tritaeniorhynchoides following batches of virus isolation from mosquito specimens, and cytopathic effect was observed following inoculation into BHK-21 and C6/36 cells. The YNDC55-33 virus isolate was successfully amplified with the flavivirus primes, and a long sequence containing 300 nucleotides was obtained. Following sequence alignment using the BLAST tool, the sequence of the YNDC55-33 virus isolate had high homology with that of the genotype I Japanese encephalitis virus. A long sequence with 10 845 nucleotides in length, which encoded 3 432 amino acids, was obtained by splicing the full sequence of the YNDC55-33 virus isolate. Phylogenetic analysis based on the whole-genome sequence and E gene sequence of the YNDC55-33 virus isolate showed that the new YNDC55-33 virus isolate was most closely related to the genotype I Guizhou isolate (GenBank accession number: HM366552), with nucleotide homology of 98.5% and amino acid homology of 99.4%, and the YNDC55-33 virus isolate shared 97.96% ± 0.33% nucleotide homology and 99.35% ± 0.08% amino acid homology with other genotype I Japanese encephalitis virus isolates, and < 90% nucleotide homology and < 98% amino acid homology with other genotypes of Japanese encephalitis virus. The YNDC55-33 virus isolate and the live attenuated virus vaccine candidate SA14-14-2 isolate differed at 16 amino acid sites on E gene, and 7 out of 8 key amino acid sites related to neurovirulence. The secondary and tertiary structures of the E protein of the YNDC55-33 virus isolate were predicted to be characterized by random coils. Conclusions A genotype I Japanese encephalitis virus was isolated from Cx. tritaeniorhynchus in Dongchuan District, Kunming City. This virus isolate and the live attenuated virus vaccine candidate SA14-14-2 isolate does not differ at antigenic epitopes-related key amino acid sites, and the major protein structure of the virus isolate is random coils. This study adds new data for the epidemiological distribution of Japanese encephalitis virus in Yunnan Province, which may provide insights into the prevention and control of Japanese encephalitis in the province.

Objective To analyze the influencing factors of unplanned extubation(UE)occurrence of peripherally inserted central catheter(PICC)in the patients with hematological diseases.Methods A retro-spective cohort study method was adopted.The data of 7 298 patients with hematological diseases implanted with PICC catheter and followed up to its removal from January 1,2016 to December 31,2020 in the Hematol-ogy Hospital of Chinese Academy of Medical Sciences were collected,including the demographic information,catheterization records,maintenance and extubation records.According to whether UE occurring,they were divided into the UE group(n=262)and normal extubation group(n=7 036).The general data were com-pared between the two groups.The COX regression was used to analyze the influencing factors of UE in pa-tients with hematological diseases.The dose-effect relationship between age and PICC UE occurrence risk was studied by the restrictive cubic spline method.Results The incidence rate of UE was 3.6％(262/7 298).The COX regression analysis results showed that the gender,disease diagnosis,fibrinogen,prothrombin time,PLT,catheter material,number of punctures during catheterization,positioning method of catheter tip,num-ber of catheter-related complications occurrence were related to PICC UE occurrence in the patients with he-matological diseases(P＜0.05).The results of restricted cubic spline showed that there was a"U"-type non-linear relationship between age and UE risk(X2=17.710,P＜0.05),and the risk of UE was the lowest when the age was 30 years old.Conclusion In PICC,the emphasis should be paid to the male patients with hemato-logical malignancies who have repeated punctures during catheterization,no intracardiac electrocardiographic positioning during catheterization,bleeding tendency,indwelling polyurethane catheters and repeated catheter-related complications in order to decrease the UC occurrence probability.

With the progress of information technology and intelligent technology,the intelligent development of urine testing instruments is facing new opportunities.Using the disease cybernetics theory model to analyze the business process and current urine testing instruments of clinical urine analyzer,a generational theoretical model of urine testing instruments has been constructed,which is conducive to guiding the intelligent development direction of urine testing instruments.The study divides urine testing instruments into one to four generations of products,with the first-generation of products being operated by doctors.The second-generation products are currently available for laboratory technicians to use various urine analyzers.The third-generation products further optimize the testing process and intelligence,without the need for inspectors to operate.The fourth-generation products are unmanned and do not require sampling.It can be seen that with the development of technology,urine analysis has indeed become more convenient,but after all,various instruments have their limitations.Therefore,the establishment of a theoretical model for the generation of urine testing instruments should be applied in clinical urine testing,which can not only improve the efficiency of urine analysis but also improve its quality.

Summarizing the nursing experience of a child with HHV-6B encephalitis after umbilical cord blood transplantation and CAR-T therapy. The child was 4 years old and was diagnosed with acute T lymphocytic leukemia on May 28, 2021. Nursing points: meticulously observe symptoms for early diagnosis and treatment; develop a specialized management plan, implement individualized care; enhance medication management to improve the quality of care; establish a shared decision-making communication model to prevent hospital-acquired infections; provide patient-centered care for lumbar puncture; assess the needs of the child and family, alleviate negative emotions; improve pre-discharge preparation, emphasize continuity of care. With proactive treatment and careful nursing, the child′s condition improved, and they were discharged. Follow-up for six months showed the child in a sustained remission state with no adverse sequelae, and normal life resumed.

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.

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.

Shoulder pain ranks the third in musculoskeletal pain,with relatively high incidence in the population.Early diagnosis of shoulder diseases is crucial.Deep learning(DL)in shoulder joint imaging was conducive to clinical diagnosis,treatment and prognosis evaluation of shoulder diseases.The research progresses of DL in shoulder joint imaging were reviewed in this article.

Chronic chloropropene poisoning is a disease mainly caused by peripheral nerve damage due to close contact with chloropropene in industrial production, its clinical manifestations include varying degrees of sensory, motor, or tendon reflex disorders in the distal limbs, and neuromyography can show neurogenic damage. This article analyzed and summarized the clinical characteristics, diagnosis and treatment methods of three patients with occupational chronic chloropropene poisoning, in order to enhance the clinical understanding of occupational chronic chloropropene poisoning and provide reference for clinical diagnosis and treatment.

Chronic chloropropene poisoning is a disease mainly caused by peripheral nerve damage due to close contact with chloropropene in industrial production, its clinical manifestations include varying degrees of sensory, motor, or tendon reflex disorders in the distal limbs, and neuromyography can show neurogenic damage. This article analyzed and summarized the clinical characteristics, diagnosis and treatment methods of three patients with occupational chronic chloropropene poisoning, in order to enhance the clinical understanding of occupational chronic chloropropene poisoning and provide reference for clinical diagnosis and treatment.