Although metal blocks have been widely used for reconstructing uncontained tibial bone defects, the influence of their elastic modulus on the stability of tibial prosthesis fixation remains unclear. Based on this, a finite element model incorporating constrained condylar knee (CCK) prosthesis, tibia, and metal block was established. Considering the influence of the post-restraint structure of the prosthesis, the effects of variations in the elastic modulus of the block on the von Mises stress distribution in the tibia and the block, as well as on the micromotion at the bone-prosthesis fixation interface, were investigated. Results demonstrated that collision between the insert post and femoral prosthesis during tibial internal rotation increased tibial von Mises stress, significantly influencing the prediction of block elastic modulus variation. A decrease in the elastic modulus of the metal block resulted in increased von Mises stress in the proximal tibia, significantly reduced von Mises stress in the distal tibia, decreased von Mises stress of the block, and increased micromotion at the bone-prosthesis fixation interface. When the elastic modulus of the metal block fell below that of bone cement, inadequate block support substantially increased the risk of stress shielding in the distal tibia and fixation interface loosening. Therefore, this study recommends that biomechanical investigations of CCK prostheses must consider the post-constraint effect, and the elastic modulus of metal blocks for bone reconstruction should not be lower than 3 600 MPa.
Knee Prosthesis ; Humans ; Finite Element Analysis ; Tibia/surgery* ; Elastic Modulus ; Arthroplasty, Replacement, Knee/methods* ; Stress, Mechanical ; Metals ; Prosthesis Design ; Knee Joint/surgery* ; Biomechanical Phenomena

Objective:To investigate the demand of rural elderly in Shenyang for integrated medical and elderly care service model,providing references for the improvement and development of rural integrated medical and elderly care services in Shenyang.Methods:Elderly individuals from selected rural areas in Shenyang were randomly sampled as study subjects.A questionnaire survey was conducted to analyze their basic demographics,satisfaction with current elderly care services,and demand levels for integrated medical and elderly care programs.Multiple linear regression analysis was used to identify factors influencing the demand for integrated medical and elderly care services among rural elderly.Results:The satisfaction scores of the rural elderly for medical care,cultural and recreational activities,spiritual comfort,and daily living assistance were 3.86±1.37,3.67±1.36,3.49±1.45,and 3.15±1.58,respectively.Multiple linear regression analysis showed that gender,monthly family income,occupation,insurance situation,living situation,and self-care ability were factors influencing the demand for integrated medical and elderly care services(P＜0.05).Conclusion:The demand for integrated medical and elderly care service model among rural elderly is affected by multiple factors.

Objective To quantitatively assess the correlation between the skeletal muscle index(SMI)of patients and the occur-rence of anastomotic leakage(AL)in rectal cancer patients after surgery,and to analyze the risk factors for AL in rectal cancer patients and the influencing factors of sarcopenia.Methods The clinical,pathological,and related imaging data of 362 patients who under-went radical surgery for rectal cancer were retrospectively analyzed.All patients underwent pelvic MRI and abdominal CT scans(plain/enhanced)within one month before surgery,and the third lumbar vertebra skeletal muscle area(L3-SMA)was measured from the images.All patients were divided into AL group(56 cases)and control group(306 cases)based on the presence or absence of postoperative complications.The differences in clinical characteristics and imaging parameters between the two groups were analyzed.A logistic risk prediction model was established.Results Significant differences were observed between the two groups in sarcopenia,type of surgery,surgical approach,serum albumin level,operation duration,stoma type,and extramural vascular invasion(EMVI)(P＜0.05).These factors were incorporated in a multivariate logistic regression analysis model,the area under the curve(AUC)of receiver operating characteristic(ROC)curve of the model was 0.810[95％confidence interval(CI)0.743-0.876,P＜0.001],with a sensitivity of 0.865 and specificity of 0.669.Conclusion Sar-copenia is a significant risk factor for AL after rectal cancer surgery.It enhances the predictive efficacy for postoperative AL and serves as a basis for identifying high-risk populations for AL in clinical practice.

Purpose To develop and validate a nomogram incorporating high-resolution MRI and clinicopathological indicators for predicting distant metastasis after curative resection of mid-low rectal cancer.Materials and Methods This retrospective study analyzed 219 patients with pathologically confirmed mid-low rectal cancer from Tianjin Union Medical Center(December 2016 to December 2021).Patients were categorized into metastasis(n=46)and non-metastasis(n=173)groups based on postoperative distant metastasis occurrence.All patients underwent preoperative pelvic MRI with measurement of posterior mesangial thickness(PMT),mesentery fat area(MFA)and mesenteric fascia envelopment volume(MFEV)on high-resolution T2WI.Clinicopathological and imaging data were collected.Cox proportional hazards model identified predictive factors for distant metastasis,and a risk probability nomogram was constructed.Predictive performance,goodness-of-fit and clinical applicability were evaluated.Results Kaplan-Meier analysis demonstrated significantly higher distant metastasis risk in patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 compared to those with higher values(χ2=29.07,8.71,19.05;all P<0.05).Cox regression identified tumor differentiation(HR=0.536,95％CI 0.290-0.990),pathological N stage(HR=0.397,95％CI 0.210-0.747),perirectal structure invasion(HR=0.242,95％CI 0.068-0.865)and PMT(HR=0.334,95％CI 0.168-0.664)as independent predictors.The nomogram achieved a concordance index of 0.775 with good calibration.Decision curve analysis demonstrated substantial net benefit across wide probability thresholds,indicating excellent clinical applicability.Conclusion Patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 exhibit elevated distant metastasis risk.The nomogram incorporating tumor differentiation,pathological N stage,perirectal structure invasion and PMT effectively predicts distant metastasis after curative resection of mid-low rectal cancer.

Purpose To develop and validate a nomogram incorporating high-resolution MRI and clinicopathological indicators for predicting distant metastasis after curative resection of mid-low rectal cancer.Materials and Methods This retrospective study analyzed 219 patients with pathologically confirmed mid-low rectal cancer from Tianjin Union Medical Center(December 2016 to December 2021).Patients were categorized into metastasis(n=46)and non-metastasis(n=173)groups based on postoperative distant metastasis occurrence.All patients underwent preoperative pelvic MRI with measurement of posterior mesangial thickness(PMT),mesentery fat area(MFA)and mesenteric fascia envelopment volume(MFEV)on high-resolution T2WI.Clinicopathological and imaging data were collected.Cox proportional hazards model identified predictive factors for distant metastasis,and a risk probability nomogram was constructed.Predictive performance,goodness-of-fit and clinical applicability were evaluated.Results Kaplan-Meier analysis demonstrated significantly higher distant metastasis risk in patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 compared to those with higher values(χ2=29.07,8.71,19.05;all P<0.05).Cox regression identified tumor differentiation(HR=0.536,95％CI 0.290-0.990),pathological N stage(HR=0.397,95％CI 0.210-0.747),perirectal structure invasion(HR=0.242,95％CI 0.068-0.865)and PMT(HR=0.334,95％CI 0.168-0.664)as independent predictors.The nomogram achieved a concordance index of 0.775 with good calibration.Decision curve analysis demonstrated substantial net benefit across wide probability thresholds,indicating excellent clinical applicability.Conclusion Patients with PMT≤1.43 cm,MFA≤19.31 cm2 and MFEV≤137.46 cm3 exhibit elevated distant metastasis risk.The nomogram incorporating tumor differentiation,pathological N stage,perirectal structure invasion and PMT effectively predicts distant metastasis after curative resection of mid-low rectal cancer.

Objective:To investigate the demand of rural elderly in Shenyang for integrated medical and elderly care service model,providing references for the improvement and development of rural integrated medical and elderly care services in Shenyang.Methods:Elderly individuals from selected rural areas in Shenyang were randomly sampled as study subjects.A questionnaire survey was conducted to analyze their basic demographics,satisfaction with current elderly care services,and demand levels for integrated medical and elderly care programs.Multiple linear regression analysis was used to identify factors influencing the demand for integrated medical and elderly care services among rural elderly.Results:The satisfaction scores of the rural elderly for medical care,cultural and recreational activities,spiritual comfort,and daily living assistance were 3.86±1.37,3.67±1.36,3.49±1.45,and 3.15±1.58,respectively.Multiple linear regression analysis showed that gender,monthly family income,occupation,insurance situation,living situation,and self-care ability were factors influencing the demand for integrated medical and elderly care services(P＜0.05).Conclusion:The demand for integrated medical and elderly care service model among rural elderly is affected by multiple factors.

Objective To quantitatively assess the correlation between the skeletal muscle index(SMI)of patients and the occur-rence of anastomotic leakage(AL)in rectal cancer patients after surgery,and to analyze the risk factors for AL in rectal cancer patients and the influencing factors of sarcopenia.Methods The clinical,pathological,and related imaging data of 362 patients who under-went radical surgery for rectal cancer were retrospectively analyzed.All patients underwent pelvic MRI and abdominal CT scans(plain/enhanced)within one month before surgery,and the third lumbar vertebra skeletal muscle area(L3-SMA)was measured from the images.All patients were divided into AL group(56 cases)and control group(306 cases)based on the presence or absence of postoperative complications.The differences in clinical characteristics and imaging parameters between the two groups were analyzed.A logistic risk prediction model was established.Results Significant differences were observed between the two groups in sarcopenia,type of surgery,surgical approach,serum albumin level,operation duration,stoma type,and extramural vascular invasion(EMVI)(P＜0.05).These factors were incorporated in a multivariate logistic regression analysis model,the area under the curve(AUC)of receiver operating characteristic(ROC)curve of the model was 0.810[95％confidence interval(CI)0.743-0.876,P＜0.001],with a sensitivity of 0.865 and specificity of 0.669.Conclusion Sar-copenia is a significant risk factor for AL after rectal cancer surgery.It enhances the predictive efficacy for postoperative AL and serves as a basis for identifying high-risk populations for AL in clinical practice.

Objective To investigate the biomechanical effects of the backside design of tibial trays on the bone-prosthesis fixation interfaces in unicompartmental knee arthroplasty(UKA).Methods Finite element models of medial knee arthroplasty were constructed using a fixed UKA prosthesis.The knee joint load and joint motion under walking motion were considered as boundary conditions,and the differences in tibial von Mises stress,contact stress,and micromotion of the bone-prosthesis fixation interface of the UKA tibial trays with big keel,small keel,two-peg with fin,three-oblique peg,and three-upright peg types were compared.Results At the maximum medical knee force moment,compared to the two-peg with fin type,the tibial von Mises stress,contact stress,and micromotion of the bone-prosthesis fixation interface decreased by 8%and 15.9%and increased by 9.9%for the big keel type;decreased by 12.3%and increased by 7.5%and 0.9%for the small keel type;decreased by 10%,10.5%,and increased by 1.2%for the three-oblique peg type;and decreased by 7.7%,14.7%,and 1.6%for the three-upright peg type,respectively.However,the maximum micromotion of the bone-prosthesis fixation interface occurred at 21%of the gait cycle.Compared to the two-peg with fin type,the micromotion of the bone-prosthesis fixation interface increased by 11.6%for the big keel type,increased by 1.6%for the small keel type,decreased by 0.4%for the three-oblique peg type,and decreased by 2.3%for the three-upright peg type.Conclusions To improve the long-term fixation effects of tibial prostheses,it is recommended to focus on a two-upright peg with fin or small keel designs when UKA tibial trays are designed,which can effectively balance the stress transfer and interface micromotion,thereby ensuring prosthesis stability and reducing the risk of aseptic loosening.

Abstract Dry eye disease is a chronic ocular surface inflammatory disease caused by abnormal tear quality or quantity and decreased tear film stability due to various reasons, and often accompanied by ocular discomfort such as itching, dryness, foreign body sensation, and visual dysfunction, which can seriously affect the patient′s quality of life and visual quality if not intervened in time. With the change of social lifestyles, the increase of environmental pollution and the trend of population aging, dry eye disease has become the most common ocular surface disease besides refractive error. Currently, dry eye disease is widely recognized as a non-infectious immune-related inflammatory disease, but the signaling pathways involved in dry eye disease are poorly understood. Whether dry eye disease is caused by excessive tear evaporation, insufficient tear production, or mucin deficiency, the ocular surface tissues(cornea/conjunctiva) inevitably undergo pathological processes such as aberrant proliferation, squamous epithelial hyperplasia, initiation of corneal damage repair mechanisms, and reduction in the number of conjunctival goblet cells, whereas the Wnt/β-catenin pathway is known to have a wide range of biological functions and plays an important role in cell proliferation, differentiation, and stemness maintenance. Therefore, this review describes the pathogenesis and potential experimental therapeutic options of the Wnt/β-catenin signaling pathway in dry eye disease from this perspective, aiming to provide new targets for the treatment of dry eye disease and achieve the goal of controlling the disease progression from the root.

Sinapic acid (SA) is a phenolic acid that is widely distributed in fruits and vegetables, which has various bioactivities, such as antidiabetic, anticancer and anti-inflammatory functions. Over-activated microglial is involved in the development progress of neurodegenerative diseases, such as Parkinson’s disease and Alzheimer’s disease. The objective of this study was to investigate the effect of SA in microglia neuroinflammation models. Our results demonstrated that SA inhibited secretion of the nitric oxide (NO) and interleukin (IL)-6, reduced the expression of inducible nitric oxide synthase (iNOS) and enhanced the release of IL-10 in a dose-dependent manner. Besides, our further investigation revealed that SA attenuated the phosphorylation of AKT and MAPK cascades in LPS-induced microglia. Consistently, oral administration of SA in mouse regulated the production of inflammationrelated cytokines and also suppressed the phosphorylation of MAPK cascades and AKT in the mouse cerebral cortex. These results suggested that SA may be a possible therapy candidate for anti-inflammatory activity by targeting the AKT/MAPK signaling pathway.