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.

BACKGROUND:Spleen has the functions of blood storage,hematopoiesis,and immunity.With the increase of age,the structural degeneration and functional decline of spleen lead to the impairment of immune system function,thus accelerating the aging process of the body.The treatment of spleen aging in tree shrews with highly active umbilical cord mesenchymal stem cells has not been reported. OBJECTIVE:To explore the intervention effect and mechanism of highly active umbilical cord mesenchymal stem cells on spleen aging in tree shrews. METHODS:Highly active umbilical cord mesenchymal stem cells were isolated,cultured,and obtained from the umbilical cord tissue of newborn tree shrews by caesarean section.The differentiation abilities of adipogenesis,osteogenesis,and chondrogenesis were detected by three-line differentiation kit.Cell cycle and surface markers were detected by flow cytometry.The second generation of highly active umbilical cord mesenchymal stem cells were transfected with Genechem Green Fluorescent Protein with infection complex values of 100,120,140,160,180,and 200,respectively,to screen the best transfection conditions.After transfection,the fourth generation of highly active umbilical cord mesenchymal stem cells was injected into the tail vein of tree shrews in the elderly treatment group.The young control group and the aged model group were not given special treatment.After 4 months of treatment,the spleen tissue was taken and the structure of the spleen was observed by hematoxylin-eosin staining.β-Galactosidase staining was used to detect the activity of aging-related galactosidase.Immunohistochemical staining was used to detect the expression levels of p21 and p53 proteins.Ki67 and PCNA immunofluorescence staining was used to detect cell proliferation activity.Immunofluorescence staining was used to detect the expression levels of spleen autophagy protein molecules Beclin 1 and APG5L/ATG5.Reactive oxygen species fluorescence staining was used to detect the content of reactive oxygen species in spleen tissue.CD3 immunofluorescence staining was used to detect the change of the proportion of total T lymphocytes.The secretion levels of interleukin 1β and transforming growth factor β1 in spleen were detected by enzyme linked immunosorbent assay.The distribution of highly active umbilical cord mesenchymal stem cells labeled with green fluorescent protein in spleen tissue was observed by DAPI double staining of nucleus. RESULTS AND CONCLUSION:(1)Highly active umbilical cord mesenchymal stem cells grew in a short spindle shape with fish-like growth,with a large proportion of G0/G1 phase,and had the potential to differentiate into adipogenesis,osteogenesis,and chondrogenesis.(2)Multiplicity of infection=140 and transfection for 72 hours were the best conditions for labeling tree shrews highly active umbilical cord mesenchymal stem cells with Genechem Green Fluorescent Protein.(3)Compared with the aged model group,in the aged treatment group,the spleen tissue cells of tree shrews were arranged closely,and the area of white pulp was increased(P<0.01);the boundary between red pulp and white pulp was clear;the proportion of germinal centers did not show statistically significant difference(P>0.05).The activity level of galactosidase related to spleen tissue aging was decreased(P<0.001),and the expression levels of aging protein molecules p21 and p53 were down-regulated(P<0.001).The expression levels of proliferation-related molecules Ki67 and PCNA were up-regulated(P<0.001,P<0.05);expression levels of autophagy-related molecules Beclin 1 and APG5L/ATG5 were up-regulated(P<0.001),and the content of reactive oxygen species decreased(P<0.001),and the proportion of CD3+T cells increased(P<0.05).The secretion level of interleukin 1β in the aging-related secretion phenotype decreased(P<0.001);no significant difference was found in transforming growth factor β1 level(P>0.05).Compared with the young control group,the above indexes were significantly different in the elderly treatment group(P<0.05).(4)Green fluorescent cells labeled with green fluorescent protein were observed in spleen tissue of tree shrews the elderly treatment group by frozen tissue section observation.The results show that intravenous infusion of highly active umbilical cord mesenchymal stem cells can migrate to spleen tissue,inhibit the production of reactive oxygen species,down-regulate the expression of aging-related proteins,induce autophagy,promote cell proliferation,reduce chronic inflammation,and then improve the structure and function of spleen tissue.

Objective To analyze the literature related to diphenidol tablets poisoning,the characteristics of poisoning were summarized to provide reference for controlling the suicidal abuse risk of diphenidol tablets.Methods The global literature on suicide,overdose,poisoning,shock,and death related to difenidol published from January 1,2011 to December 31,2022 was analyzed,including gender,age,dosage,cardiac(blood)concentration,poisoning symptoms,etc.Results Young women were the majority of people with poisoning.The highest proportion of the age group is 11 to 30 years group.Patients who take medication doses greater than 3 000 mg may have a higher risk of death;patients with a heart(blood)concentration greater than 6 μg·mL-1 may have a higher risk of death.Malignant arrhythmia,consciousness disorders,coma,and apnea are common serious adverse events during poisoning.Conclusion It is recommended that the drug regulatory authorities should require the Listing permit holder of difenidol tablets to add the risk and symptoms of poisoning into the instructions.It is suggested that restricting individual consumers from purchasing large amounts of difenidol tablets in the short term.It is recommended that canceling the high-dose sales packaging of difenidol tablets.It is suggested that converting difenidol tablets into prescription drugs,even consider canceling the registration certificate of difenidol tablets.

Lower-cost genotyping technology has promoted the generation of large genetic datasets with the evolving next-generation sequencing technology. The emergence of genome-wide association studies (GWAS) has facilitated researchers’ understanding of common complex diseases. GWAS refers to finding the sequence variations present in the human genome and screening out disease-related single nucleotide polymorphisms (SNPs). These SNPs are considered as the basis for assessing the stability of complex diseases. However, a single variation is not sufficient to assess an individual’s risk of disease. Polygenic risk score (PRS) is an emerging genetic data analysis method for quantitatively estimating an individual’s genetic risk for complex diseases by comprehensively considering multiple genetic variation sites. A single-value estimate of an individual’s genetic risk for a certain phenotype can be calculated as the cumulative impact of multiple genetic variants by building a PRS model. The finally expected risk score is weighted by the strength and direction of association of each SNP with the phenotype based on the number of alleles carried by each SNP. With the continuous development of various PRS calculation methods and the constant accumulation of genomic data, PRS has received widespread attention in the field of genetics. So far, quite a few studies at home and abroad have shown that PRS is valuable in risk prediction of different types of human traits or complex diseases, and its effectiveness has been further verified in clinical applications. At present, many studies have established PRS models based on GWAS summary statistics to quantify the genetic risk of susceptibility loci and clinical characteristics on diseases such as lung cancer, breast cancer, coronary heart disease, diabetes and Alzheimer’s disease. The disease-susceptible populations can be recognized through comparing the relative risk and absolute risk of the disease in different risk groups according to the population risk stratification results. Additionally, individual-level genotype data and omics data can also be used as data sources for PRS analysis research, especially the latter can dynamically reflect the short-term or long-term effects of environmental factors on human gene expression, and has potential application value in building early warning models to assess health risks. Since the calculation of PRS involves a large amount of genomic data analysis, there are big differences in the methods for data selection, model building and validation. Different PRS construction methods and software have different performances in disease risk prediction, and even the performance of same algorithm varies across diseases. It is worth noting that the PRS model often needs to be re-evaluated and verified for different groups of people, because PRS is affected by race and region. This review combines currently published PRS-related research and algorithms to describe the basic principles of PRS, compares their construction and verification methods, and discusses their applications and prospects. As a powerful genetic risk assessment tool, PRS has great potential in analyzing the genetic code of complex diseases and achieving precise diagnosis and personalized treatment.

Objective:To identify the strengths and weaknesses of hospital development through the application of individual scientific research performance assessment, thereby providing a basis for the formulation of science and technology policies.Methods:We established a research performance assessment system and conducted research performance assessments across the hospital for three consecutive years. The assessment results were analyzed in-depth, utilizing the Kruskal-Wallis test to determine if there were differences in the overall level of assessment scores between years and series; the Mann-Whitney test to analyze differences between the promoted and non-promoted groups; the χ2 test to analyze whether age, degree, gender, and maternity situations affected assessment grades. Results:From 2020 to 2022, the individual scientific research performance assessment scores showed an overall upward trend, with the average per capita assessment score increasing significantly from 35.26 points in 2020 to 74.04 points in 2022. There were statistical differences in the assessment scores of different professional titles, indicating that the senior professionals > the associate senior professionals > the intermediates. There was no significant difference between the promoted and non-promoted groups. Additionally, age, degree, gender, and maternity factors affected assessment grades.Conclusions:It has been preliminarily established that the assessment of individual scientific research performance can effectively steer the scientific innovation activities of researchers, and play a positive role in enhancing the overall scientific research strength. The findings from the data analysis indicate that the hospital is expected to continuously enhance its scientific research performance by focusing on newly recruited doctoral personnel, establishing a system of support and guidance, and providing preferential support to female researchers. The assessment results serve as a " benchmark" for management departments and provide data-driven insights for the development of science and technology policies.

BACKGROUND:Periodontitis is an inflammatory and destructive disease with plaque biofilm as the main pathogenic material,which occurs in the gingiva,periodontal ligament,alveolar bone and cementum.The antigen of bacterial complex and its secreted toxin and enzyme directly lead to the destruction of periodontal tissue and trigger the host's immune response,causing indirect damage to the body tissue.Silence information regulatory factors(Sirtuins,SIRTs)play an important role in anti-aging,anti-oxidative stress,regulating inflammation,and mediating autophagy,and are closely related to the occurrence and development of periodontitis. OBJECTIVE:To review the research status of Sirtuins in periodontitis. METHODS:The first author used the computer to search the relevant research regarding the role of Sirtuins in periodontitis in PubMed,Web of Scene,CNKI and WanFang databases.The key words were"Sirtuins,Sirtuin1-7,periodontitis"in English and Chinese.After literature screening,57 articles were included for review and analysis. RESULTS AND CONCLUSION:SIRT1,SIRT2,SIRT3,and SIRT6 participate in regulating the occurrence and development of periodontitis.Inhibition of SIRT1 expression may be the target of periodontitis treatment,while overexpression of SIRT1 can inhibit periodontitis and protect periodontal tissue.The activator of SIRT1 can reduce the inflammation of periodontal tissue and improve the systemic pathological changes caused by periodontitis.SIRT2 is involved in nicotinamide phosphoribosyltransferase-mediated periodontal inflammation and plays a role in the treatment and prognosis of periodontal diseases.SIRT3 can improve age-related periodontal disease.Gastrodin promotes the osteogenic differentiation of periodontal ligament stem cells through the up-regulation of SIRT3.The activator of SIRT3 reduces the damage of periodontitis to periodontal and renal tissues by regulating the level of autophagy in the cells.SIRT6 can inhibit the inflammatory reaction of periodontal tissue and inhibit the differentiation and mineralization of cementoblasts.SIRT6 is beneficial to the prognosis of periapical periodontitis.The relationship between SIRT4,SIRT5,SIRT7 and periodontitis is rarely reported.

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".

Medical education in China has undergone many changes amid the revolution of medical education worldwide. The Healthy China initiative in the new era highlights the increasing demand for a high-quality children's health service system as well as more excellent pediatricians. This article aims to delve into the current opportunities and challenges of pediatric education in China, summarize the response strategies, and take a look at the new mode of talent cultivation in pediatric medicine. With the rapid shift in the newborn population, the strengthening of multidisciplinary collaboration, the development of medical informatization, and the continuous improvement in scientific research levels, pediatric medical education is facing unprecedented opportunities. However, the late start of pediatrics and the lack of high-level talents have also brought great challenges to pediatric medical education. Therefore, future efforts should be focused on multi-disciplinary cooperation and innovative education and teaching to nurture pediatrician-scientists with innovative abilities and practical experience.

Objective:This study aimed to explore the status of radiological Kashin-Beck disease (KBD) among school-aged children in Chamdo City, Tibet, through a 3-year monitoring survey, providing epidemiological evidence for prevention and control strategies.Methods:The target areas for this study were Luolong, Bianba, and Basu counties in Chamdo City, Tibet Autonomous Region, identified as having the most severe historical cases of KBD. Children aged 7-12 years attending school were enrolled as study subjects. Anteroposterior X-ray films of the right-hand were taken, and radiological diagnoses were made based on the "Diagnosis of Kashin-Beck Disease" criteria (WS/T 207-2010). Two experienced researchers independently reviewed the X-rays, and intra- and inter-group consistency were assessed using weighted Kappa values and percentage agreement. Cross-sectional surveys were conducted in 2017 and 2020 to describe the X-ray detection rates of KBD, and logistic regression analysis was employed to construct a predictive model of risk factors for radiological KBD cases.Results:In 2017, a total of 5,711 children aged 7-12 years in Chamdo City, Tibet, participated in the baseline cross-sectional survey (average age 9.2 years, 48.0% female), with 28 cases of radiological KBD. The age- and gender-standardized prevalence rate was 0.527%. In 2020, 6,771 participants (average age 9.3 years, 49.5% female) underwent a second cross-sectional survey, with 9 cases of radiological KBD and a standardized prevalence rate of 0.134%. Logistic regression analysis indicated that older age [ OR=2.439, 95% CI(1.299, 4.580), P=0.006] and female gender [ OR=8.157, 95% CI(1.016, 65.528), P=0.048] were independent risk factors for radiological KBD cases. Conversely, higher residential altitude, under the premise of Tibet's high altitude, was a protective factor [ OR=0.995, 95% CI(0.990, 0.999), P=0.032). Conclusion:The radiographically positive detection rate of KBD among school-aged children in Chamdo City, Tibet Autonomous Region, is at an extremely low level and showing a declining trend, reaching the historical standard in 2020. Considering the absence of positive signs in affected children, it suggests that local KBD has been effectively eliminated.

AIM To investigate the variation rules of main secondary metabolites in Hedysari Radix before and after rubbing strip.METHODS UPLC-MS/MS was adopted in the content determination of formononetin,ononin,calycosin,calycosin-7-glucoside,medicarpin,genistein,luteolin,liquiritigenin,isoliquiritigenin,vanillic acid,ferulic acid,γ-aminobutyric acid,adenosine and betaine,after which cluster analysis,principal component analysis and orthogonal partial least squares discriminant analysis were used for chemical pattern recognition to explore differential components.RESULTS After rubbing strip,formononetin,calycosin,liquiritigenin and γ-aminobutynic acid demonstrated increased contents,along with decreased contents of ononin,calycosin-7-glucoside and vanillic acid.The samples with and without rubbing strip were clustered into two types,calycosin-7-glucoside,formononetin,γ-aminobutynic acid,vanillic acid,calycosin-7-glucoside and formononetin were differential components.CONCLUSION This experiment clarifies the differences of chemical constituents in Hedysari Radix before and after rubbing strip,which can provide a reference for the research on rubbing strip mechanism of other medicinal materials.