BACKGROUND:With the development of computer-aided design and computer-aided manufacturing technology,zirconia abutments with a titanium base are widely used in clinic due to its good application advantages,but there are still some problems and a lack of consensus design standards. OBJECTIVE:To review the fabrication methods of Ti-base zirconia abutment,and the effect of abutment connection,emergence design,abutment angle,and bonding on mechanical properties of Ti-base zirconia abutment. METHODS:Relevant literature published from 2010 to 2023 was searched in CNKI and PubMed databases with the search terms"zirconia abutment,titanium base"in Chinese and English,respectively.The search time limit was extended for some classical literature.The relevant literature was obtained through inclusion and exclusion criteria,and 57 eligible documents were included for review. RESULTS AND CONCLUSION:It is recommended that clinicians try to select antirotational titanium bases or rotational titanium bases with a Morse taper connection.Implants should be placed in the correct axial angulation of not more than 15° or with an inclination to the palatal side when using angled zirconia abutments.When a≥30° labial inclination is followed for implant placement,the bite force must be decreased effectively to reduce the risk of mechanical and biological complications of implants,abutments,and prostheses.Ti-base zirconia abutments with a higher gingival height should be selected,and its restorative angle should not exceed 40°.Multilink Hybrid Abutment could be the first choice for extraoral bonding of zirconia abutment to titanium bases.

The Burkholderia cepacia complex (Bcc) comprises a group of genetically related yet phenotypically diverse Gram-negative opportunistic pathogens. These organisms demonstrate significant pathogenicity in immunocompromised populations, particularly cystic fibrosis (CF) and chronic granulomatous disease (CGD) patients, causing severe infections including pneumonia, bacteremia, and urinary tract infections. Notably, Bcc infection in CF patients may progress to acute respiratory failure or the life-threatening "cepacia syndrome". Of particular concern is the widespread nosocomial colonization by Bcc strains coupled with their sophisticated multidrug resistance mechanisms, which contribute substantially to clinical treatment failures. This review systematically examines the epidemiological characteristics, clinical manifestations and resistance mechanisms of Bcc. The review aims to provide evidence-based references for improving accurate diagnosis and enhancing infection control measures against this challenging pathogen.

Objective:To analyze the histopathological characteristics of peri-implant soft tissue in re-constructed jaws and the changes after keratinized mucosa augmentation(KM A)with free gingival graft(FGG).Methods:Twenty patients were enrolled in this study.Five patients of them,who were perio-dontal and systemic healthy and referred for crown lengthening before restoration with healthy keratinized gingiva collected were enrolled as healthy controls.15 patients of them were with fibula or iliac bone flaps jaw reconstruction(10 with fibula flap and 5 with iliac flap),who were referred to FGG and implant exposures before restoration.Soft tissue was collected before FGG in reconstructed jaws,and in 5 patients(3 with fibula flap and 2 with iliac flap)8 weeks after FGG if a second surgery was conducted.Histologi-cal analysis with hematoxylin-eosin stain and immunological analysis to interlukin-1(IL-1),interlukin-6(IL-6)and tumor necrosis factor-α(TNF-α)were performed.Results:Thickness from the bottom of stratum basale to the top of stratum granulosum and thickness of keratinized layer in reconstructed jaws were significantly lower compared with that of natural healthy keratinized gingiva[0.27(0.20,0.30)mmvs.0.36(0.35,0.47)mm,P＜0.05;16.49(14.90,23.37)μm vs.26.37(24.12,31.53)μm,P＜0.05].In the reconstructed area,thickness from the bottom of stratum basale to the top of stra-tum granulosum increased after KMA with FGG[0.19(0.16,0.25)mm vs.0.38(0.25,0.39)mm,P=0.059]and the thickness of keratinized layer significantly increased after KMA with FGG[16.42(14.16,22.35)μm vs.28.57(27.16,29.14)μm,P＜0.05],which was similar to that in the con-trol group.Furthermore,the number of positive cells of IL-1,IL-6 and TNF-α significantly increased after KMA[0.67(0.17,8.93)vs.11.00(9.16,18.00);13.00(8.50,14.14)vs.21.89(15.00,28.12);0.22(0.04,0.63)vs.2.83(1.68,5.00),respectively,P＜0.05]as well as the average optical density value[0.15(0.14,0.17)vs.0.18(0.17,0.21);0.28(0.26,0.33)vs.0.36(0.33,0.37);0.23(0.22,0.29)vs.0.30(0.28,0.42),respectively,P＜0.05],which was similar to that in the healthy keratinized gingiva.Conclusion:The lack of rete pegs and inflammato-ry factors were common in soft tissue with jaw reconstruction.FGG can improve the quality of the epithe-lium and may improve the stability of the mucosa around implants.

Objective To investigate the genetic risk factors of deep vein thrombosis(DVT)after trauma.Methods In a nested case-control study,50 patients with DVT after traumatic lower extremity fractures and 50 patients without DVT were recruited.The two groups were matched with gender,age and fracture sites.Preoperative venography was performed to diagnose DVT in trauma patients.Genome wide association study(GWAS)was used to investigate the genetic risk factors for preoperative DVT after traumatic lower ex-tremity fractures.Genomic DNA in leukocytes from blood sample was extracted and used for GWAS.Results GWAS was conducted based on 2 662 single nucleotide variants(SNV)which were dispersed in 144 interested genes.Ten genes were found to have signifi-cant association with trauma-related DVT,including cofactors of hemostasis mechanism,i.e.,THBD,F5,SERPIND1 and ITGA2,the factors related to vitamin K-dependent(VKD)carboxylation,i.e.,GGCX and CALU,and the members of cytochrome P450 family,i.e.,CYP1A1,CYP3A4,CYP2C19 and CYP2B6.Conclusion DVT after trauma might be regulated by the cofactors of hemostasis mechanism,the factors related to VKD carboxylation and the members of cytochrome P450 family.The results of our study may provide reference and inspiration for genetic susceptibility of preoperative DVT after trauma.

ObjectiveTo explore the improving effects and its synergistic mechanism of Olibanum before and after processing with vinegar on glycodesoxycholic acid（GDCA） intervention in mice with ulcerative colitis（UC） based on the perspective of intestinal flora. MethodC57BL/6J male mice were randomly divided into the normal group， model group， GDCA group， Olibanum group（1.5 g·kg^-1） and vinegar-processed Olibanum（1.5 g·kg^-1） group， with 6 mice in each group. Mice in the normal group drank water freely， and mice in the other groups were given 2% dextran sulfate sodium（DSS） periodically to establish a UC mouse model. During the modeling， GDCA group， Olibanum group and vinegar-processed Olibanum group were intervened by intraperitoneally injection of GDCA（0.05 g·kg^-1）. From the 13^th day after modeling， Olibanum group and vinegar-processed Olibanum group were given the corresponding doses of drugs by gavage， once a day， for 36 d. During this period， the body mass of mice was recorded and the disease activity index（DAI） was assessed. On day 48， faeces were collected for 16S rRNA and metagenomic sequencing to analyse changes in intestinal flora. On the 49^th day， hematoxylin-eosion（HE） staining was used to observe the colon histological lesions， enzyme-linked immunosorbent assay（ELISA） was used to determine serum levels of tumour necrosis factor-α（TNF-α）， interleukin（IL）-1β and IL-6， and Spearman correlation analysis was used to explore the correlation between differential bacterial species and inflammatory factor levels. ResultCompared with the normal group， the model group showed a significant decrease in body weight（P<0.01）， a significant increase in DAI（P<0.05）， and a significant increase in TNF-α， IL-1β and IL-6 levels（P<0.01）， and there was partial infiltration of inflammatory cells in the colon. Compared with the model group， mice in the GDCA group showed a significant decrease in body weight， a significant increase in DAI and levels of TNF-α， IL-1β and IL-6（P<0.01）， and severe disruption of colonic crypt structure， extensive infiltration of inflammatory cells， and a significant decrease in goblet cells. Compared with the GDCA group， both the Olibanum and vinegar-processed Olibanum groups showed a significant recovery in body weight， a significant decrease in DAI and levels of TNF-α， IL-6 and IL-1β（P<0.05， P<0.01）， and the modulating effect of vinegar-processed Olibanum was significantly better than that of Olibanum. Alpha diversity showed that Chao1 index of UC mice significantly increased（P<0.01） and Shannon index decreased significantly（P<0.05） in UC mice after GDCA intervention. Beta diversity showed that the microbial community structure of the 5 groups had significant changes， Olibanum and vinegar-processed Olibanum could modulate the changes in the structure of the intestinal flora in UC mice after GDCA intervention. Microbial sequencing results indicated that， compared with the normal group， the Firmicutes/Bacteroidetes ratio in the model group was significantly higher（P<0.05）， and the relative abundance of 3 genera and 5 species of flora changed significantly（P<0.05， P<0.01）. Compared with the model group， the Firmicutes/Bacteroidetes ratio in the GDCA group was significantly higher（P<0.05）， the relative abundance of 7 pathogenic bacterial genera and four species was significantly increased（P<0.05， P<0.01）， and the relative abundance of three beneficial bacterial genera and Bacteroides_intestinalis was significantly decreased（P<0.05， P<0.01）. Olibanum group and vinegar-processed Olibanum group could modulate the Firmicutes/Bacteroidetes ratio， the relative abundance of pathogenic bacteria and beneficial bacteria， and the vinegar-processed Olibanum group was significantly superior to Olibanum group in terms of modulating the Firmicutes/Bacteroidetes ratio， the relative abundance of the three genera and five species of bacteria（P<0.01， P<0.05）. Correlation analysis showed that the relative abundance of Bacteroides_intestinalis was negatively correlated with the levels of TNF-α， IL-6 and IL-1β， the relative abundance of Prevotella_sp_CAG873， Bacteroides_sp_CAG927， Bacteroidales_bacterium_52_46 and Bacteroidales_bacterium was positively correlated with TNF-α， IL-6 and IL-1β levels. ConclusionGDCA can exacerbate UC colonic inflammation， and Olibanum and vinegar-processed Olibanum have an ameliorative effect on GDCA-mediated UC， with the vinegar-processed Olibanum showing a stronger ameliorative effect， the mechanism may be related to the regulation the abundance and structure of intestinal beneficial and pathogenic bacteria， and the reduction of inflammatory factor levels.

BACKGROUND:It was found that the ligands and receptors of Notch are both cell membrane surface proteins,which are important proteins to mediate intercellular communication,and the Notch signaling pathway plays a crucial regulatory role in the proliferation and differentiation of mesenchymal stem cells. OBJECTIVE:To review the regulatory mechanism of the Notch signaling pathway on the proliferation and differentiation of mesenchymal stem cells,summarize and clarify the research advance in how the Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells,and provide theoretical support for the future use of stem cells to treat various related diseases. METHODS:By using the computer,the first author searched the relevant studies involving Notch signaling pathway regulation of mesenchymal stem cell proliferation and differentiation on CNKI,Wanfang,VIP,PubMed,Web of Science,and Nature databases with Chinese search terms"mesenchymal stem cells,Notch,Notch signaling pathway,proliferation,differentiation"and the English search terms"mesenchymal stem cells,MSC,Notch,Notch signaling pathway,proliferation,differentiation".Part of the literature was searched in combination with the literature tracing method.Finally,87 articles were included in the review analysis. RESULTS AND CONCLUSION:(1)Notch signaling pathway is a conserved signaling pathway in multicellular organisms,which plays an important role in regulating cell differentiation,proliferation,apoptosis,and the cell cycle by mediating communication between neighboring cells through receptor-ligand binding.(2)Mesenchymal stem cells are a class of adult stem cells with self-proliferative and multi-directional differentiation potential,which can be regulated by external signaling pathways to affect their proliferation and differentiation.Notch signaling pathway,as one of them,when Notch ligands are activated,the Notch proteins will undergo two protein hydrolysis cleavages to release Notch intracellular structural domain NICD,which then enters the nucleus and thus promotes the transcription of target genes to regulate the proliferation and differentiation of mesenchymal stem cells from different sources,such as bone marrow,adipose,and umbilical cord.However,the specific mechanisms that regulate the proliferation and differentiation of mesenchymal stem cells from different tissue sources of the same species are different.(3)The Notch signaling pathway can regulate the differentiation of mesenchymal stem cells into different target cells,but due to different target cells,the expression levels of receptors or ligands in the Notch signaling pathway vary.(4)Clinical targeting of the Notch signaling pathway to promote mesenchymal stem cells for the treatment of various refractory diseases,such as aplastic anemia,severe joint injuries,ischemic strokes,and myocardial infarctions,has a promising application.(5)By exploring the Notch signaling pathway via regulating the expression levels of its receptors and ligands in bone marrow mesenchymal stem cells from rat,mouse,and human,it can be found that the Notch signaling pathway expression levels in the proliferation and differentiation of mesenchymal stem cells from different species origins are also different.(6)The role of mesenchymal stem cells in tissue engineering has been gradually highlighted due to their advantages of safety,low immune rejection,and wide therapeutic prospects.The Notch signaling pathway regulates the proliferation and differentiation of mesenchymal stem cells with a wide range of influencing factors,and subsequent studies should further optimize the influencing factor variables and explore the standardized studies of regulating the proliferation and differentiation of mesenchymal stem cells.

BACKGROUND:With the increasing demand for edentulous jaw restoration,"All-on-4"concept is widely used.The load transfer mode of implant is different from that of natural tooth.The three-dimensional finite element analysis can study the stress distribution of implants and surrounding bone tissues under functional loading.On this basis,it provides research methods for finding suitable implant materials,optimizing implant geometry,and designing clinical surgical protocols. OBJECTIVE:To review researches related to three-dimensional finite element analysis in"All-on-4"concept. METHODS:Relevant literature published from 2003 to 2023 was searched in CNKI and PubMed databases with the search terms of"finite element method;All-on-4;edentulous;biomechanics"in Chinese and English.Finally,65 articles were included for review. RESULTS AND CONCLUSION:(1)In the case of insufficient horizontal bone mass,we can choose to apply narrow diameter implants,but we need to pay attention to the effect of the presence of the cantilever on the stress distribution and reduce the risk of failure.(2)The"All-on-4"concept reduces the stress distribution of bone by tilting the distal middle implant,but the ideal angle of the distal implant tilt in different jaw types requires further study.(3)The presence of cantilevers increases the risk of implant failure,and keeping the cantilever length/AP distance ratio at 0.9 helps to minimize mechanical complications.(4)When a framework is made of a material with a lower elastic modulus,the stress on the framework itself will be smaller,but it will increase the stress on the implant,prosthetic screw,abutment and peri-implant bone.On the contrary,when a material with a higher elastic modulus is used,it can reduce the stress on the prosthetic components,implants and peri-implant bone in the restoration,but the stress on the framework itself is higher.(5)The"All-on-4"concept allows for a better mechanistic balance,but requires the development of a long-term,effective treatment program that is tailored to the patient's specific situation.(6)Proper occlusal scheme is the key to the success of implant treatment,and there is no difference between canine-guide occlusion and group function occlusion in terms of the longevity of the restoration.However,there are many factors that influence occlusal design,and further in vitro experiments as well as a number of clinical studies are needed to explore the ideal occlusal design of the"All-on-4".

Objective:To explore the characteristics, prevention and treatment strategies of lower urinary tract injury in transvaginal reconstructive pelvic surgery (vRPS).Methods:A retrospective analysis was conducted on 24 patients who suffered lower urinary tract injuries occuring in vRPS from January 2005 to June 2021, among which 4 cases were referred to our hospital from other hospitals.Results:(1) In our hospital, 1 952 patients underwent vRPS for anterior and (or) middle pelvic organ prolapse during that study period, with a 1.0% (20/1 952) incidence of lower urinary tract injuries occurring in 20 cases. (2) Ureteral injuries were observed in 14 cases who underwent transvaginal high uterosacral ligament suspension (1.4%, 14/966). The symptoms were relieved after the removal of sutures. (3) Bladder injuries occurred in 6 cases in our hospital, with 4 cases (0.7%, 4/576) in anterior transvaginal mesh surgery (aTVM), one (0.4%, 1/260) in colpocleisis, and one (0.7%, 1/150) in apical suspension for fornix prolapse. An additional 4 cases of bladder injury were referred to our hospital after aTVM. Among the 8 cases of bladder injury during aTVM, 2 cases were intraoperative incidents. Cystoscopy confirmed that the superficial branch or puncture rod of anterior vaginal mesh had penetrated into the bladder. Re-puncturing and placement of the mesh were successfully performed. No abnormalities were observed during a follow-up period of 4-5 years. Postoperative bladder injuries were identified in 6 cases, characterized by mesh erosion into the bladder and formation of calculi. These injuries were confirmed between 6 months to 2 years after vRPS. The exposed mesh and calculi in the bladder were removed through laparotomy or cystoscopy, followed up for 2-12 years. One case experienced slight re-erosion of mesh to the bladder.Conclusions:Lower urinary tract injuries are difficult to avoid in vRPS, particularly in transvaginal high uterosacral ligament suspension and aTVM. However, the incidence is low. Lower urinary tract injuries during vRPS could be easily detected and managed intraoperatively because of the use of cystoscopy. As long-term postoperative complications, erosion of transvaginal mesh to lower urinary tract postoperatively could be treated correctly, seldom with severe sequelae.

Objective:To conduct quantitative evaluation on the revise requirements of Specifications of Air Sampling for Hazardous Substances Monitoring in the Workplace (GBZ 159-2004) , clarify the problems and suggestions during its implementation for improvement, and provide a basis for the revision of the standard.Methods:From April to September 2021, stratified convenient sampling method was adopted and semi-open questionnaire was used to investigate the occupational health personnel in CDC, occupational prevention and control institutes, employers, third-party technical service institutions and universitie. The entropy weight of each index and the score based on entropy weight of GBZ 159 were calculated. Spearman rank correlation analysis was used to describe the correlation between the two indexes and radar chart was drawn for comprehensive evaluation.Results:A total of 151 questionnaires were received from the respondents, of which 147 were valid, with an effective recovery rate of 97.35%, involving 29 provinces, autonomous regions and municipalities. The median G scores of the necessity and urgency of GBZ 159 revision based on entropy weight were 2.84 and 3.17, respectively, and the difference was statistically significant ( M=-25.50, P<0.001) . The trend of the score G of necessity and urgency based on entropy weight was basically the same for all secondary items ( rs=0.9998, P<0.001) , and the score G of urgency based on entropy weight was higher than that of necessity. The highest score G of necessity and urgency based on entropy weight was "3.13 long time sampling", which were 7.56 and 8.23 respectively. This was followed by "3.12 short time sampling", which were 7.19 and 7.13 respectively. Conclusion:GBZ 159 has encountered some new problems and challenges in the implementation process, and some of its technical indicators have been out of line with the actual practice of occupational health at present. These are the two items that urgently needs to be revised and improved, such as "3.13 long time sampling" and "3.12 short time sampling" and other items need to be revised and improved.

Systematically evaluate the implementation of Specifications of Air Sampling for Hazardous Substances Monitoring (GBZ 159-2004) , so as to provide technical basis for the future standard revision. The semi-structured interview method was used to interview the industry experts from centers for disease control and prevention, occupational disease prevention and control hospitals/institutes, employers, third-party technical service institutions and universities, and the induction method was used to refine the topics and relevant suggestions. Some technical indicators of GBZ 159 are not suitable for the current actual work of occupational health, and need to be revised and improved urgently. The revised GBZ 159 should comply with the current situation of China's industrial development and the development of occupational health testing equipment in the new era, and improve the relevant technical requirements of sampling quality control.