BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.

BACKGROUND:Clinical studies suggest that both bone quality and excessive crown-to-implant ratio are factors that affect the success rate of implant surgery,but there is no consensus on how large the crown-to-implant ratio under each bone quality will affect the prognosis of implant repair.OBJECTIVE:To analyze the stress and strain of bone tissue around implant restorations with different crown-to-implant ratios under different bone types after stress loading using three-dimensional finite element method.Combined with the Frost bone mechanics regulation system theory,the physiological limits of bone strain were observed for each bone type within a certain range of crown to implant ratios.METHODS:Cone beam CT data were selected from a patient to establish solid bone block models with four different bone types(class Ⅰ bone:cortical bone thickness 3 mm+dense cancellous bone,class Ⅱ bone:cortical bone thickness 2 mm+relatively dense cancellous bone,class Ⅲ bone:cortical bone thickness 1 mm+relatively low-density cancellous bone,class Ⅳ bone:cortical bone thickness 1 mm+low-density cancellous bone).Implant restorations with five different crown-to-implant ratios(1,1.5,2,2.5,and 3)were created on each bone block model,for a total of 20 models.Vertical and oblique forces were applied to the dental crown to observe the von Mises stress values,strains,and displacement of the cortical and cancellous bones,as well as the degree of implant displacement.RESULTS AND CONCLUSION:(1)In the class Ⅰ bone model,when the crown-to-implant ratio reached 3 under oblique loading,the cortical bone strain exceeded the physiological limit.In the class Ⅱ bone model,under oblique loading,when the crown-to-implant ratio reached 2.5,the cortical bone strain exceeded the physiological limit.In the class Ⅲ bone model,under oblique loading,cortical bone exceeded the physiological limit when the crown-to-implant ratio reached 2.5,while cancellous bone reached the critical physiological limit at 1.In the class Ⅳ bone model,under oblique loading,when the crown-to-implant ratio reached 1.5,2,2.5,and 3,the cortical bone strain exceeded the physiological limit.In the class Ⅳ bone model,all five crown-to-implant ratios of cancellous bone exceeded physiological limits.(2)Under vertical load,the cancellous bone strain exceeded the physiological limit when the crown-root ratio reached 1,2,2.5,and 3 in the class Ⅲ bone model,and when the cancellous bone strain of the five crown-root ratios in the class Ⅳ bone model exceeded the physiological limit.(3)Under oblique or vertical load,the implant displacement of the 20 groups of models did not exceed 100 μm.(4)From the perspective of biomechanics,when patients with insufficient bone height choose implant restoration,the crown-root ratio that class Ⅰ bone can tolerate is up to 2.5 times,the crown-root ratio that class Ⅱ bone can tolerate is up to 2 times,and the crown-root ratio that class Ⅲ and class Ⅳ bones can tolerate is up to 1 times due to excessive strain of cancellous bone;but the crown-root ratio that cortical bone in class Ⅲ bone can tolerate is up to 2 times.Whether class Ⅲ bone can tolerate implant restoration with a high crown-root ratio and whether cancellous bone can tolerate higher strains needs further study.

ObjectiveTo explore the potential mechanism of Weicanqing Formula （微残清方， WF） combined with chemotherapy in treating acute myeloid leukemia （AML） based on malic enzyme 2 （ME2）-mediated bone marrow immune-metabolic homeostasis and . MethodsSixty-five male C57BL/6N mice were randomly divided into control group， model group， WF group， chemotherapy group， and the combination group （WF plus chemotherapy）， with 13 mice per group. Except for the control group， mice were injected with C1498 cells （appro-ximately 1×10⁶ cells per mouse） via the tail vein on day 1 to establish an AML model. Starting from day 8， mice in the chemotherapy group and the combination group were administered with cytarabine at 30 mg/（kg·d） via subcutaneous injection， once daily for 3 consecutive days； WF group and the combination group received WF at 7.54 g/（kg·d） by gavage， once daily for 21 consecutive days. On days 1， 7， 14， 21 and 28， hemoglobin （Hb） and white blood cell （WBC） levels were determined in each group. On day 28， Giemsa staining was used to observe morphological changes in bone marrow cells. Flow cytometry was employed to detect the expression levels of bone marrow T lympthocyte subsets， including CD8⁺， CD4⁺， and regulatory T lymphocytes （Treg）. The contents of glutamine （Gln）， nicotinamide adenine dinucleotide phosphate （NADP⁺）， and reduced nicotinamide adenine dinucleotide phosphate （NADPH） in bone marrow were determined using visible spectrophotometry. Adenosine triphosphate （ATP） concentration in bone marrow was measured by chemiluminescence assay. The mRNA expression of malic enzyme 2 （ME2） in bone marrow was detected by RT-qPCR， and the protein expression level of ME2 was determined by Western blotting. ResultsCompared to the control group， the model group showed decreased Hb levels on day 14， 21， and 28， and increased WBC levels on day 7， 14， 21， and 28 （P＜0.05）. On day 28， bone marrow CD8⁺ and CD8⁺/CD4⁺ levels decreased， while Treg cells， ATP， Gln， NADP⁺， NADPH， ME2 mRNA， and their corresponding protein levels increased （P＜0.05）. Compared to the model group， the chemotherapy group and the combination group both exhibited reduced Hb level on day 14， 21 and 28， as well as the increased WBC level； the combination group showed increased CD8⁺ level， decreased Treg， ATP， Gln， and NADPH content， as well as reduced ME2 mRNA expression and protein levels （P＜0.05）. Compared to the chemotherapy group， the combination group showed significantly increased Hb level on days 21 and 28， and increased WBC level on day 28 （P＜0.05）. Bone marrow smear pathology revealed that， in the model group， myeloid blast cells exhibited cytoplasmic vacuoles indicative of abnormal metabolic activity. In contrast， both the chemotherapy group and the combination group showed large numbers of metamyelocytes and band neutrophils， with only a few immature granulocytic blast cells observed. ConclusionWF may improve the prognosis of AML when used as an adjunct to chemotherapy by modulating ME2 expression， inhibiting metabolic energy competition within the bone marrow microenvironment， and reshaping the distribution of T lymphocyte subsets in the bone marrow.

Objective To compare functional differences of CD8+T cells in lung tissues between young and aged C57BL/6J mice during the contraction phase and memory immune response phase after infection with influenza A(H1N1)virus.Methods Lung tissues from young(3-month-old)and aged(24-month-old)C57BL/6J female mice without influenza virus infection were collected to prepare single-cell suspensions,which were stimulated with phorbol 12-myristate 13-acetate(PMA)/ionomycin or cluster of differentiation(CD)3/CD28 antibodies(T-cell antigen receptor/co-stimulatory signals)respectively(non-specific antigens stimulation).Flow cytometry intracellular cytokine staining(ICS)was performed on lung CD8+T cells to detect their secretion capacity of tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ).Young and aged C57BL/6J mice were infected intranasally with 490 PFU PR8 influenza virus,and reinfected with homologous influenza virus 28 days later.Lung tissues were isolated on day 28(the contraction phase)and day 32(the memory immune response phase)after primary infection.Influenza virus-specific MHC-Ⅰ tetramer staining was used to detect the proportion of virus-specific CD8+T cells in lung tissue CD8+T cells,and ICS was used to analyze TNF-α,IFN-γ,and granzyme B expression in CD8+CD44high T cell subset.Results After non-specific antigen stimulation,TNF-α and IFN-γ secretion capacity in lung tissue CD8+T cells of aged group mice was significantly higher than that of young group(P＜0.05).After virus-specific antigen stimulation,there were no statistically significant differences in the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B between the two groups of mice during the contraction phase(P＞0.05),while during the memory immune response phase,the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B in the aged group mice were significantly lower than those in the young group(P＜0.05).Conclusion CD8+T cells in aged mice maintain normal immune-related factor expression function under non-specific antigen stimulation,but show impaired immune-related factor expression function during antigen-specific memory immune response phase,suggesting that aging leads to defects in the formation or maintenance of CD8+T cell immune memory.

Objective:To investigate the clinical results of gasless endoscopic thyroidectomy via posterior chest-collarbone approach (GETPCA) compared with open neck surgery for papillary thyroid carcinoma (PTC) .Mthods:Retrospective analysis of PTC patients admitted to the Department of Thyroid and Breast Surgery of the Third Affiliated Hospital of Anhui Medical University from Jan. 2022 to Dec. 2023,and randomly divided into the open group and the lumbo-scopic group according to whether or not they had a requirement for an unmarked neck, in which the open group was n=100,and the lumbo-scopic group was n=67,with 39 male cases and 128 female cases. Clinicopathological characteristics, surgery-related indexes, postoperative complications, postoperative pain scores and postoperative cosmetic satisfaction were compared between the two groups.The t-test,Wilcoxon rank-sum test, χ2 test, consecutively corrected χ2 test, or Fisher’s exact probability method were used to compare the groups. Results:No recurrence was seen during the follow-up period,and none of the cases in the luminal group was open in the middle. The differences in age, body mass index BMI, gender, relative tumor location,preoperative TSH, T stage and N stage between the two groups were not statistically significant ( P>0.05) . The total operation time [ (121.07±39.80) min vs. (93.87±26.97) min]in the luminal group was greater than that in the open group,intraoperative bleeding was less than that in the open group, and the postoperative drainage flow[ (130.69±31.01) mL vs. (105.52±32.71) mL] was greater than that in the open group in the postoperative period of 72 h, and the difference was statistically significant ( P<0.001) .There was no statistical difference between the two groups in terms of 24-h postoperative drainage volume, number of central zone lymph node dissection, number of positive central zone lymph nodes,postoperative hospitalization days or total hospitalization cost ( P>0.05) .The number of cases of neck discomfort (3 cases vs.23 cases, P<0.001) and swallowing dysfunction (2 cases vs.20 cases, P=0.003) in the luminal group was smaller than that in the open group,and the difference was statistically significant.The difference in the incidence of bleeding,incision infection,seroma,temporary recurrent laryngeal nerve injury and temporary parathyroid gland injury between the two groups was also not statistically significant ( P>0.05) .The postoperative NRS on day 1 and postoperative NRS on day 3 of the luminal group were lower than those of the open group,and the difference was statistically significant ( P>0.05) ,while there was no statistically significant difference between the postoperative NRS on day 7,the postoperative NRS on month 1 and the postoperative NRS on month 3 ( P>0.05) .Cosmetic satisfaction at 6 months postoperatively was higher in the luminal group than in the open group,and the difference was statistically significant ( P<0.001) . Conclusion:GETPCA for the treatment of the PTC is safe and feasible,with satisfactory cosmetic results and reduction of neck discomfort and swallowing dysfunction,which is worthy of clinical popularization.

Objective To observe imaging manifestations of spinal chronic osteomyelitis.Methods Totally 56 patients with spinal chronic osteomyelitis were retrospectively enrolled,including 18 cases complicated with synovitis,acne,pustulosis,hyperostosis and osteomyelitis(SAPHO)syndrome while 38 cases did not.CT and MRI manifestations were observed.Results Among 56 cases,cervical spine involvement was observed in in 25 cases(25/56,44.64％).Single spine segment involvement,2 segments involvements and 3 or more segments involvements were found in 17(17/56,30.36％),18(18/56,32.14％)and 21 cases(21/56,37.50％),respectively.The ratio of 3 or more segments involvements in 18 cases with SAPHO syndrome was 61.11％(11/18),while in 38 cases without SAPHO syndrome was 26.32％(10/38),the former was higher than the latter(P＜0.05).Meanwhile,16 cases(16/56,28.57％)complicated with compression fracture,30(30/56,53.57％)with hyperosteogeny,22(22/56,39.29％)with paraspinal soft tissue swelled and 15(15/56,26.79％)with extra spinal involvements.The ratio of extra spinal involvement in patients with and without SAPHO syndrome was 72.22％(13/18)and 5.26％(2/38),respectively,the former was higher than the latter(P＜0.05).Conclusion Imaging manifestations of spinal chronic osteomyelitis had certain characteristics.In patients complicated with SAPHO syndrome,3 or more segments of spine involvements were common,with more extra spinal involvements.

Objective To establish a quantifiable quality control index system for infection management in neonatal specialty hospitals for the comprehensive evaluation of neonatal healthcare-associated infection(HAI)management quality,and to promote the continuous enhancement and improvement of neonatal HAI management quality.Methods The framework of the index system was preliminarily established through literature research and focus group discussion,the indexes were repeatedly screened using Delphi expert consultation approach,and the weights of each index were determined using the analytic hierarchy process.The empirical study of the established index sys-tem was conducted using TOPSIS method and rank sum ratio method.Results Three rounds of expert consultation were conducted,and the effective response rate of the questionnaire was 100％.The authoritative coefficient of the third round of expert consultation was 0.89,and the Kendall's coefficient of concordance for expert opinion was 0.322.The established index system included 3 first-level indexes,6 second-level indexes,and 16 third-level inde-xes.Thirteen of third-level indexes could be directly obtained from the hospital information system.Conclusion The quality control index system for neonatal HAI management established in this study is relatively scientific,with rational weights and all quantifiable indexes.It can be used for vertical and horizontal evaluations of neonatal HAI management quality,providing a reference for the continuous improvement of neonatal HAI management work.

BACKGROUND:The development of calcium phosphate bone cement is limited due to its poor mechanical properties and weak osteogenic ability.Silicate bioactive glass is highly favored due to its excellent biological activity and osteogenic ability.Simultaneously,fiber structures can enhance the mechanical strength of materials.OBJECTIVE:To investigate the mechanical properties,biocompatibility,and osteogenic effect of silicate bioactive glass fiber composite calcium phosphate bone cement.METHODS:Different mass percentages(0％,10％,and 20％)of silicate bioactive glass fiber were added to the solid phase of calcium phosphate bone cement,mixed with the liquid phase and cured for 48 hours to obtain silicate bioactive glass fiber composite calcium phosphate bone cement.The mechanical properties,setting time,and ion precipitation of the cement were characterized.The three groups of bone cement extracts were co-cultured with MC3T3-E1 cells.The cell compatibility of the materials was evaluated by CCK-8 assay,live/dead staining,and phalloidin staining.After osteogenic induction,the osteogenic induction ability of the materials was evaluated by alkaline phosphatase staining,alizarin red staining,RUNX2 immunofluorescence staining,and RT-PCR.RESULTS AND CONCLUSION:(1)With the increase of silicate bioactive glass fiber content,the compressive strength and flexural strength of bone cement increased,and the setting time was prolonged.When bone cement was immersed in simulated body fluid,the precipitation of silicon ions,calcium ions,and phosphorus ions could be detected.Moreover,with the increase of silicate bioactive glass fiber content,the mass concentration of silicon ions and phosphorus ions released by bone cement increased,and the mass concentration of calcium ions decreased.(2)Live/dead staining and phalloidin staining results exhibited that silicate bioactive glass fiber composite calcium phosphate bone cement had no toxic effect on MC3T3-E1 cells.CCK-8 assay results showed that silicate bioactive glass fiber composite calcium phosphate bone cement could promote the proliferation of MC3T3-E1 cells.(3)With the increase of silicate bioactive glass fiber content in bone cement,the alkaline phosphatase activity and extracellular calcium deposition of MC3T3-E1 cells increased,the expression of RUNX2 protein increased,and the expression of alkaline phosphatase,osteocalcin,osteopontin,and RUNX2 mRNA expression increased.(4)The results indicate that silicate bioactive glass fibers can enhance the mechanical properties and osteogenic induction ability of calcium phosphate bone cement,among which 20％silicate bioactive glass fibers have a more obvious effect.

Objective:To establish a reference interval for serum iodine of pregnant women with normal thyroid function and to analyze the relationship between serum iodine and thyroid disease risk.Methods:From July 2022 to October 2023, using cross-sectional survey method, pregnant women aged 18 to 48 years old who had lived in iodine-deficient areas in the six provinces of China (Shanxi Province, Fujian Province, Yunnan Province, Xinjiang Uygur Autonomous Region, Zhejiang Province, and Anhui Province) for more than six months were selected as the survey subjects. Blood samples were collected, serum iodine was tested, and the percentile method was used to establish a reference interval for serum iodine of pregnant women with normal thyroid function. Meanwhile, serum levels of free thyroxine, thyroid stimulating hormone, thyroglobulin antibody (TgAb), and thyroid peroxidase antibody (TPOAb) were tested, and logistic regression was used to analyze the relationship between serum iodine and thyroid disease risk.Results:A total of 1 409 pregnant women from 6 provinces were investigated, including 1 087 with normal thyroid function and 322 with abnormal thyroid function. The median serum iodine level of pregnant women with normal thyroid function was 79.74 μg/L, and the preliminary reference interval for serum iodine was 47.57 - 128.96 μg/L. When serum iodine levels were lower (< 47.57 μg/L), pregnant women had a significantly increased risk of developing TgAb positivity, TPOAb positivity, hypothyroxinemia, hypothyroidism, and autoimmune thyroiditis ( OR = 4.44, 2.91, 3.41, 41.67, 23.43, P < 0.05). When serum iodine levels were high (> 128.96 μg/L), pregnant women had a significantly increased risk of developing hyperthyroidism ( OR = 9.91, P = 0.001). Conclusions:The reference interval for serum iodine of pregnant women with normal thyroid function is successfully established. Low serum iodine levels are associated with an increased risk of TgAb positivity, TPOAb positivity, hypothyroxinemia, hypothyroidism, and autoimmune thyroiditis, while high serum iodine levels are associated with an increased risk of hyperthyroidism.

Objective To compare functional differences of CD8+T cells in lung tissues between young and aged C57BL/6J mice during the contraction phase and memory immune response phase after infection with influenza A(H1N1)virus.Methods Lung tissues from young(3-month-old)and aged(24-month-old)C57BL/6J female mice without influenza virus infection were collected to prepare single-cell suspensions,which were stimulated with phorbol 12-myristate 13-acetate(PMA)/ionomycin or cluster of differentiation(CD)3/CD28 antibodies(T-cell antigen receptor/co-stimulatory signals)respectively(non-specific antigens stimulation).Flow cytometry intracellular cytokine staining(ICS)was performed on lung CD8+T cells to detect their secretion capacity of tumor necrosis factor-α(TNF-α)and interferon-γ(IFN-γ).Young and aged C57BL/6J mice were infected intranasally with 490 PFU PR8 influenza virus,and reinfected with homologous influenza virus 28 days later.Lung tissues were isolated on day 28(the contraction phase)and day 32(the memory immune response phase)after primary infection.Influenza virus-specific MHC-Ⅰ tetramer staining was used to detect the proportion of virus-specific CD8+T cells in lung tissue CD8+T cells,and ICS was used to analyze TNF-α,IFN-γ,and granzyme B expression in CD8+CD44high T cell subset.Results After non-specific antigen stimulation,TNF-α and IFN-γ secretion capacity in lung tissue CD8+T cells of aged group mice was significantly higher than that of young group(P＜0.05).After virus-specific antigen stimulation,there were no statistically significant differences in the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B between the two groups of mice during the contraction phase(P＞0.05),while during the memory immune response phase,the proportion of virus-specific CD8+T cells and the expression levels of TNF-α,IFN-γ,and granzyme B in the aged group mice were significantly lower than those in the young group(P＜0.05).Conclusion CD8+T cells in aged mice maintain normal immune-related factor expression function under non-specific antigen stimulation,but show impaired immune-related factor expression function during antigen-specific memory immune response phase,suggesting that aging leads to defects in the formation or maintenance of CD8+T cell immune memory.