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.

AIM:To investigate the effect of 3% diquafosol sodium eye drops on tear film homeostasis in patients wearing overnight orthokeratology lenses.METHODS:Retrospective study. A total of 340 patients(564 eyes)fitted with night-worn orthokeratology lenses from June to December 2022 were respectively divided into a diquafosol sodium group(200 cases, 323 eyes, treated with 3% diquafosol sodium eye drops)and a sodium hyaluronate group(140 cases, 241 eyes, treated with sodium hyaluronate eye drops). The uncorrected visual acuity(LogMAR), ocular surface disease index(OSDI), non-invasive tear film break-up time(NIBUT), meibomian gland infrared imaging score, and corneal epithelial fluorescein staining were analyzed and compared between the two groups.RESULTS:Compared to baseline, both groups showed significant improvements in uncorrected visual acuity(LogMAR)at 1 wk, 1, and 3 mo after lens wear(all P<0.01). However, no statistically significant difference in uncorrected visual acuity(LogMAR)was observed between the two groups at any time point(all P>0.05). No significant differences in NIBUT or OSDI scores were found between the groups before and at 1 wk after lens wear(all P>0.05). At the 1- and 3 mo follow-ups, the 3% diquafosol sodium group demonstrated significantly longer NIBUT(all P<0.001)and lower OSDI scores(all P<0.001)compared to the sodium hyaluronate group. After wearing lens for 3 mo, the meibomian gland infrared imaging scores were significantly better in the diquafosol sodium group(P<0.001), whereas no significant intergroup difference was observed in corneal fluorescein staining(P>0.05). Furthermore, the incidence of adverse events during the study period did not differ significantly between the two groups(P>0.05).CONCLUSION:Compared with sodium hyaluronate, 3% diquafosol sodium eye drops were more effective in maintaining tear film homeostasis in patients wearing overnight orthokeratology lenses.

Objective To construct a logistic regression prediction model for stress ulcer(SU)after cerebral hemorrhage.Methods A total of 230 patients with cerebral hemorrhage admitted to our hospital from January 2020 to January 2023 were prospectively selected as the study subjects.They were randomly di-vided into a training group and a validation group using a random number table method,with 115 patients in each group.The incidence of postoperative SU was statistically compared between the two groups.The least absolute shrinkage and selection operator(Lasso)and logistic regression were used to analyze the influencing factors of SU after cerebral hemorrhage,and a logistic regression prediction model was established and valida-ted.Results The incidence of SU was 19.13%in the training group and 20.00%in the validation group.In-crement of age,blood loss≥30 mL,higher levels of neutrophil-to-lymphocyte ratio(NLR),heat shock protein 70(HSP70)and HSP90 were identified as independent risk factors for SU after cerebral hemorrhage(P<0.05),while lower levels of Glasgow Coma Scale(GCS)score and albumin(Alb)were protective factors(P<0.05).The prediction model was logit(P)=0.409×age+1.288×blood loss-1.335×GCS score-1.126×Alb+0.452×NLR+1.483×HSP70+1.593×HSP90-10.325.The areas under the receiver operat-ing characteristic(ROC)curve(AUC)for the training group and the validation group were 0.845(95%CI:0.765-0.906)and 0.855(95%CI:0.777-0.913),respectively.The sensitivities were 81.82%and 90.91%,and the specificities were 76.34%and 70.97%,respectively.Conclusion A logistic regression prediction model was successfully constructed,which has certain predictive value for SU after cerebral hemorrhage.

In current clinical practice, various dermal templates and skin substitutes are used to enhance wound healing. However, the role of wound commensal microbiome in regulating scaffold performance and the healing process remains unclear. In this study, we investigated the influence of both natural and synthetic scaffolds on the wound commensal microbiome and wound repair in three distinct models including diabetic wounds, burn injuries, and germ-free (GF) wounds. Remarkably, synthetic electrospun polycaprolactone (PCL) scaffolds were observed to positively promote microbiome diversity, leading to enhanced diabetic wound healing compared to the natural scaffolds Integra® (INT) and MatriDerm® (MAD). In contrast, both natural and synthetic scaffolds exhibited comparable effects on the diversity of the microbiome and the healing of burn injuries. In GF wounds with no detectable microorganisms, a reversed healing rate was noted showing natural scaffold (MAD) accelerated wound repair compared to the open or the synthetic scaffold (PCL) treatment. Furthermore, the response of the wound commensal microbiome to PCL scaffolds appears pivotal in promoting anti-inflammatory factors during diabetic wound healing. Our results emphasize that the wound commensal microbiome, mediated by different scaffolds plays an important role in the wound healing process.

Objective:To analyze the clinical efficacy and learning curve for robot-assisted cortical bone trajectory (CBT) screw fixation performed by surgeons with different seniority in the treatment of lumbar degenerative disease.Methods:The clinical data of 91 lumbar degenerative disease patients underwent robot-assisted CBT screw fixation from August 2020 to December 2022 in Beijing Shijitan Hospital, Capital Medical University were retrospectively analyzed. Among them, 48 patients underwent surgery performed by the same senior surgeon (senior group), with a total of 234 CBT screws were placed; while 43 patients underwent surgery performed by the same junior surgeon (junior group), with a total of 206 CBT screws were placed. The surgical related indexes, functional improvement score, lower back pain and lower limb radiation pain scores, acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications were compared between two groups. The functional improvement score was evaluated using the Japanese Orthopaedic Association (JOA) score, the pain score was evaluated using visual analog score (VAS). The cumulative sum (CUSUM) method was used to depict the learning curve with "single screw placement time" as the observation index.Results:There were no statistical difference in incision length, operation time, intraoperative blood loss and postoperative hospital stay between two groups ( P>0.05). The least squares means of JOA scores 1, 3 and 6 months after surgery in both groups increased significantly compared to baseline, while the least squares means of lower back pain VAS and lower limb radiation pain VAS decreased significantly compared to baseline; there were no statistical differences between two groups ( P>0.05). There were no statistical difference in acceptable nail insertion rate, non invasion rate of facet joints and incidence of postoperative complications between two group ( P>0.05). The CUSUM learning curves were fitting well and the inflection point for senior surgeon corresponded to 18 cases, while it was reached after performing surgery on 21 cases for junior surgeon. Conclusions:Robot-assisted CBT screw fixation performed by surgeons with different seniority could achieve similar clinical outcomes for treating lumbar degenerative disease. The senior surgeons are able to complete the initial learning stage faster than the junior surgeons, but there is not much difference in the number of surgeries performed the learning curve.

Objective: To investigate the expression of ribosomal protein L26 ( RPL26) in gastric cancer cells (GC) and its effect on cell apoptosis and proliferation . Methods: The expression of RPL26 in GES-1 and GC cell lines was detected by Western blot. GC cell line HGC-27 was used to construct RPL26 overexpression cell line , and GC cell lines HGC-27 and AGS cells were used to construct RPL26 knockdown cell line . The overexpression and knockdown efficiency of RPL26 were detected by Western blot. Cell counting kit-8 (CCK-8) , colony formation assay and Transwell assay were used to detect the effects of the overexpression and knockdown of RPL26 on the pro- liferation and migration of GC cells . Western blot was used to detect the expression of Phosphatidylinositol-3-kinase (PI3K) / protein kinase B (AKT) signaling pathway related factors PI3K , AKT , phosphorylated phosphatidylinosi- tol-3-kinase (p-PI3K) , phosphorylated protein kinase B ( p-AKT) and downstream factors B-Cell lymphoma-2 (Bcl-2) , Bcl-2 associated X protein (Bax) and Cyclin A , G1 /S-specific Cyclin D1(Cyclin D1) , Cyclin-depend- ent kinases (CDK)4 and CDK2 in overexpression and knockdown of RPL26 stably transfected cell lines . Results: Compared with GES-1 , RPL26 was highly expressed in HGC-27 cells ( tHGC-27 = 4. 97 ; P < 0. 01) and elevated in AGS , but the difference was not statistically significant. In HGC-27 and AGS cells , CCK-8 and colony formation assays showed that the proliferation ability of cells decreased after the knockdown of RPL26. Transwell assay showed that the migration ability of cells decreased after the knockdown of RPL26. Western blot showed that Bcl-2 expression was decreased in HGC-27 , AGS cells after the knockdown of RPL26 ( tHGC-27 = 11 . 50 , tAGS = 4. 77 ; P < 0. 001 , P < 0. 01) , and Bax expression increased ( tHGC-27 = 9. 63 , tAGS = 4. 05 ; P < 0. 001 , P < 0. 05) . In HGC-27 cells , the ratios of p-PI3K/PI3K and p-AKT/AKT significantly decreased after the knockdown of RPL26 ( tp-PI3K/PI3K = 3 . 86 , tp-AKT/AKT = 8. 29 ; P < 0. 05 , P < 0. 01) . Cyclin A , Cyclin D1 , CDK4 , CDK2 protein expressions de- creased ( t = 9. 61 , 5 . 10 , 11 . 64 , 7. 81 ; P < 0. 01 or P < 0. 001) , while the overexpression of RPL26 in HGC-27 cells showed the opposite trend . Conclusion The knockdown of RPL26 may arrest the cell cycle in G1 /S phase by inhibiting the PI3K/AKT signaling pathway , thereby inhibiting cell proliferation and promoting apoptosis .

Objective To investigate the expression of α7 nicotinic acetylcholine receptor (α7nAChR) in thymic T follicular helper cells (TFH) and its significance in patients with myasthenia gravis (MG). Methods Fifteen MG patients who underwent surgical treatment at the Myasthenia Gravis Comprehensive Diagnosis and Treatment Center of Henan Provincial People’s Hospital from June 2022 to June 2023 were selected as a MG group, including 7 males and 8 females, aged 12-30 years. Twelve patients who underwent partial thymectomy to optimize surgical field exposure during cardiac surgery at Fuwai Central China Cardiovascular Hospital from June 2022 to June 2023 were selected as a control group, including 5 males and 7 females aged 20-35 years. Thymus single cell suspension was obtained by grinding the thymus tissue, and flow cytometry was used to detect the expression of α7nAChR in TFH cells. The thymus cell suspension was purified using density gradient centrifugation, followed by immunomagnetic bead separation to obtain CD4+T cells. CXCR5 antibody and coupled magnetic beads were added to isolate TFH cells. Real-time fluorescent polymerase chain reaction and Western blotting were performed to further investigate the expression of α7nAChR in TFH cells. Results Compared with the control group, the proportion of thymic TFH cells in the MG group was significantly increased (P<0.05), along with significantly decreased mRNA and protein expression levels of α7nAChR within these cells (P<0.01). Conclusion The findings suggest that there is a reduced expression of α7nAChR within thymic TFH cells in MG patients, leading to weakened immunosuppressive function which may indirectly contribute to disease onset and progression.

Objective To investigate the effects of Caenorhabditis elegans(C.elegans)endogenous U6 promoters on dpy-10 gene editing efficiency.Methods We screened endogenous U6 small nuclear RNA(snRNA)genes of C.elegans from the WormBase database and constructed 14 editing plasmids targeting dpy-10 by replacing the U6r07e5.16 promoter in the pSX524 plasmid(Peft-3::cas9::tbb-2 terminator::U6 r07e5.16::dpy-10 sgRNA)through molecular cloning.Gene editing was performed in wild-type C.elegans using a standardized microinjection protocol.Gene editing efficiency and the high-efficiency gene editing index were quantified based on the screening of dpy-10 mutant phenotypes in the F1 progeny.Results A total of 15 U6 snRNA genes(r07e5.16,f35c11.9,t20d3.13,k09b11.15,k09b11.16,w05b2.8,c28a5.7,f54c8.9,k09b11.11,k09b11.12,k09b11.14,t20d3.12,f54c8.8,f54c8.10,and k09b11.13)were identified from the WormBase database.Based on the editing efficiency and high-efficiency gene editing index,the activity of these promoters was evaluated,and 4 U6 promoters(w05b2.8,c28a5.7,f54c8.9,and k09b11.11)were found to have significantly enhanced gene editing success rates,outperforming other promoters,including U6r07e5.16 and U6k09b11.12,which are commonly used in the C.elegans research community.Notably,the gRNAF+E scaffold did not show superior editing efficiency over the gRNA scaffold when paired with the optimal U6w05b2.8 promoter.Conclusion In this study,U6 promoters that significantly improve gene editing efficiency in C.elegans are identified and the critical role of promoter optimization in CRISPR-Cas9 systems is highlighted.These findings provide a valuable foundation for improving genome editing strategies and offer new ideas for optimizing the CRISPR technology applied in nematode research.

Objective To optimize the real-time quantitative polymerase chain reaction(RT-qPCR)data analysis process through mathematical principles by replacing the biased 2-??CT method with a more rigorous 2-CT method,thereby improving the accuracy of gene expression quantification analysis.Methods Essentially,the CT value serves as the exponent in a base-2 exponential equation within the logic of comparative CT method.In the traditional 2-??CT method,the arithmetic means of raw CT and ΔCT values are directly calculated and the exponential nature of CT data is overlooked,which may introduce systematic bias to the calculation results.We propose a new method,entitled the 2-CT method,in which all calculations are based on the transformation of CT values into 2-CT.This includes computing the relative initial expression levels of target and reference genes within each sample,the relative abundance of the target gene,and its fold change across groups.Statistical comparisons are then performed based on fold change values.By strictly adhering to the exponential nature of of CT values,the biases introduced by arithmetic averaging at the CT or ΔCT level are avoided.We applied this method to multiple RT-qPCR datasets to evaluate the differences between the traditional 2-??CT and the proposed 2-CT methods in gene expression quantification,as well as the effect of the differences.Results In the original dataset from LIVAK and SCHMITTGEN,the two methods produced similar results.However,in the cadmium exposure experiment,findings from the 2-??CT method indicated that 8-hour cadmium exposure caused an increase of irg-6 gene expression in Caenorhabditis elegans from 1.314-fold to 7.125-fold(P=0.000 2).In contrast,findings from the 2-CT method showed a fold change from 1.0 to 4.124(P=0.001 5),a 70%difference between the two methods.Conclusion The2-CT method provides a mathematically more rigorous approach that more accurately reflects gene expression changes,particularly in experiments with high CT variability.It offers a more reliable computational paradigm for quantitative gene expression analysis.