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.

The deficiency in immunogenicity and the presence of immunosuppression within the tumor microenvironment significantly hindered the efficacy of immunotherapy. Consequently, a nanoformulation containing metal sulfide of FeS and GSDMD plasmid (NP_FeS/GD) had been developed to effectively augment antitumor immune responses through dual activation of immunogenic PANoptosis and ferroptosis, as well as reprogramming immunosuppressive effects via H₂S amplification. The bioactive NP_FeS/GD exhibited controlled release of GSDMD plasmid, H₂S, and Fe²⁺ in response to the tumor microenvironment. Fe²⁺, H₂S, and the expression of GSDMD protein could effectively elicit highly immunogenic PANoptosis and ferroptosis. Furthermore, releasing H₂S could mitigate the overexpression of indoleamine 2,3-dioxygenase1 (IDO1) induced by immunogenic PANoptotic and ferroptotic cell death and disrupt the activity of IDO1. Consequently, NP_FeS/GD effectively triggered the antitumor innate and adaptive immune responses through induction of PANoptotic and ferroptotic cell death and reshaped the tumor immunosuppressive microenvironment to enhance antitumor immunotherapy for metastasis inhibition. This study unveiled the significant potential of immunogenic PANoptosis and ferroptosis in H₂S gas therapy for enhancing tumor immunotherapy, offering novel insights and ideas for the rational design of nanomedicine to enhance tumor immunogenicity while reprogramming the tumor immunosuppressive microenvironment.

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 repair effect of amphiregulin (Areg) on injured lung tissue in mice with acute respiratory distress syndrome (ARDS) and its underlying mechanism.Methods:The ARDS mouse model was made by tracheal infusion of lipopolysaccharide (LPS), and bronchoalveolar lavage fluid (BALF) was extracted for 7 consecutive days. Adult male C57BL/6 mice were randomly (random number) divided into 5 groups ( n=4 per group): (1) Control group; (2) Areg group: mice were treated intraperitoneally (i.p.) with recombinant Areg; (3) LPS+PBS group; (4) LPS+Areg group; and (5) LPS+Anti-Areg group; mice were instilled with LPS, then were injected i.p. with PBS, Areg or Areg neutralization antibody (Anti-Areg) 30 min later. Lung tissue and BALF were extracted at day 1, 3, 5 and 7 after ARDS. HE staining was used to evaluate the pathological changes of lung tissues. The total protein content in BALF was detected by BCA method, and the concentrations of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-1β and immunoglobulin M (IgM) were determined by ELISA method. The phosphorylated levels of epidermal growth factor receptor (EGFR) and expressions of proliferating cell nuclear antigen (PCNA) and surface proteins-C (SP-C) were tested by Western blot. The immunofluorescence was used to detect the co-expression of PCNA and SP-C in lung tissues. One-way analysis of variance was used to compare the mean values of normally distributed measurement data between groups. Comparisons between groups were performed using the least significant difference t-test. Results:Compared with that at before modeling [(51.05±2.47) pg/mL], Areg concentrations were increased significantly at day 1 [(71.97±6.51) pg/mL; P<0.01] and day 3 [(147.58±7.56) pg/mL, P<0.01] in the BALF after ARDS. At day 1 after ARDS, there were significant interstitial edema, neutrophil infiltration and alveolar collapse in the LPS+PBS group and LPS+Areg group. Compared with the LPS+PBS group at day 3, 5 and 7, the pathological changes of lung tissues were notably improved in the LPS+Areg group, while were more serious in the LPS+Anti-Areg group. Compared with the control group, the LPS+PBS group had higher levels of neutrophil number, total protein, IgM, TNF-α, IL-1β, and IL-6. However, Areg treatment significantly reduced the levels of these indicators. Moreover, the expressions of PCNA (1.34±0.10), SP-C (1.48±0.10) and p-EGFR (0.92±0.032) in the LPS+Areg group were significantly up-regulated compared with those in the LPS+PBS group (0.88±0.03, 1.06±0.15, and 0.68±0.03, all P<0.01). And compared with the LPS+PBS group, PCNA and SP-C double positive cells were significantly increased in the LPS+Areg group, but decreased in the LPS+Anti-Areg group. Conclusions:Areg enhances the proliferation of alveolar typeⅡ epithelial cells by activating EGFR pathway, therefore promotes the repair of lung tissues during ARDS development.

Objective To explore the risk factors of severe pneumonia caused by multi-drug resistant Klebsiella pneumonia,and antimicrobial drug resistance among these isolates.It may help to prevent and control the disease and promote to rational use of antibiotics.Methods We conducted the case-control study in our PICU.It included 89 patients with severe pneumonia caused by multi-drug resistant Klebsiella pneumonia as case group and 68 patients with severe pneumonia caused by Klebsiella pneumonia as control group during the same period.To compare the two groups on irrationality use of antibiotics (especial for third generation cephalosporin),length of stay,tracheal cannula,time of mechanical ventilation and underlying conditions (malnutrition,congenital heart disease,heredity and metabolic disease).Antimicrobial susceptibilities among 89 multi-drug resistant Klebsiella pneumonia isolates were analyzed.Results There were 63 cases (70.79％) for irrationality use antibiotics in case group,while there were 27 cases (39.70％) in control group (P ＜ 0.01).The cases for length of stay over 7 days in case group (48 cases,53.93％) were more than those cases with the same situation in control group (12 cases,17.65 ％) (P ＜ 0.01).Thirty-eight cases (42.69 ％) needed mechanical ventilation therapy in case group,while 16 cases (23.53％) needed mechanical ventilation therapy in control group (P ＜ 0.01).The cases for duration of mechanical ventilation over 5 days in case group (18 cases,20.22％) were more than those cases in control group (5 cases,7.35％) (P ＜0.05).The cases with underlying disease in case group (13 cases,14.61％) were more than those cases in control group (2 cases,2.94％) (P ＜ 0.05).Multi-drug resistant Klebsiella pneumonia isolates demonstrated that high-level resistance for penicillins,cephalosporins,aminoglycosides and quinolones,but still susceptible to carbapenems.Conclusion Several risk factors are associated with severe pneumonia caused by multi-drug resistant Klebsiella pneumonia,including irrational use of antibiotics (especial for third generation cephalosporin),long term of length of stay,endotracheal intubation,long term of mechanical ventilation,and having underlying disease (malnutrition,congenital heart disease,heredity and metabolic disease).Multi-drug resistant Klebsiella pneumonia isolates demonstrated that high-level resistance for penicillins,cephalosporins,aminoglycosides and quinolones,but still susceptible to Carbapenems.Carbapenems should be used as first-line drugs for severe pneumonia caused by multi-drug resistant Klebsiella pneumonia.

ObjectiveTo study the correlation between the etiology and clinical features of erythroderma.MethodsThe clinical data on 182 patients with erythroderma were retrospectively collected and analyzed.ResultsThe male-to-female ratio was 2.8 ∶ 1 and the average age at onset was 58.6 ± 14.6 years.Of the 182 cases,135 (74.2％) were due to pre-existing dermatoses,14 (7.7％) to drug reaction,8 (4.4％) to malignancies,while 25(13.7％) had no obvious precipitating factors.The most frequent triggering factor was systemic consumption of drugs(52 patients,28.6％ ),and glucocorticosteroid was the most prevalent causative drug.Seventy-six patients were followed up,recurrence was observed in 14 patients but not in 58 patients,and 5 patients died,2 patients with idiopathic erythroderma were finally diagnosed with mycosis fungoides (MF)after multiple skin biopsies.ConclusionsPre-existing dermatoses are the most frequent cause of erythroderma.Idiopathic erythroderma is liable to relapse,possibly associated with malignancies,and should be closely followed up.

The purpose of this study was to screen peptides that can specifically bind to human hepatocellular carcinoma (hHCC) cells using phage display of random peptide library in order to develope a peptide-based carrier for the diagnosis or therapy of hHCC. A peptide 12-mer phage display library was employed and 4 rounds of subtractive panning were performed using the hHCC cell line HepG2 as the target. After panning, the phages that specifically bound to and internalized in hHCC cells were selected. The selected phages demonstrated highly specific affinity to HepG2 cells analyzed by ELISA and immunofluorescence analysis. 57.3% of the selected phage clones displayed repeated sequence FLLEPHLMDTSM, and 4 amino acid residues, FLEP were extremely conservative. Based on the sequencing results, a 16-mer peptide (WH-16) was synthesized. The competitive ELISA showed that the binding of the phage clones displayed sequence FLLEPHLMDTSM to HepG2 cells was efficiently inhibited by WH-16. Our findings indicate that cellular binding of phage is mediated via its displayed peptide and the synthesized 16-mer peptide may have the potential to be a delivery Carrier in target diagnosis or therapy for hHCC.