BACKGROUND:Total knee arthroplasty serves as an effective intervention for the treatment of late-stage knee joint disorders.However,prosthetic liners are prone to wear and failure due to internal stress variations,resulting in limited lifespan and decreased postoperative patient activity.Addressing how to enhance prosthetic design to meet a broader range of patient needs constitutes a significant focus in prosthesis research. OBJECTIVE:Based on the morphological design of the meniscus,we propose an asymmetric design prosthesis and compare it with a symmetric posterior stabilized prosthesis.The stress distribution patterns and variations in the contact area of the liners for both prostheses were analyzed to explore whether the asymmetric prosthesis design offers advantages over the symmetric design. METHODS:Using the finite element method,we simulated the osteotomy and prosthesis assembly in a knee osteoarthritis patient.Two different prostheses(asymmetric design and posterior stabilized)were employed to establish post-total knee arthroplasty knee joint models.Under flexion conditions at 0°,10°,20°,and 30°,we investigated the Mises stress on the femoral and tibial components as well as the liner.Additionally,by comparing the contact area on the inner and outer sides of the liner,we aimed to explore the changes in biomechanics and alterations in motion behavior in the post-total knee arthroplasty knee joint. RESULTS AND CONCLUSION:(1)Throughout the flexion range from 0 to 30 degrees,the Mises stress peak on the liner exhibited a trend of initial decrease followed by an increase,with the stress on the medial side consistently surpassing that on the lateral side.(2)In comparison to the posterior stabilized prosthesis,the asymmetrically designed prosthesis demonstrated smaller stress peaks.At a flexion angle of 30 degrees,the Mises stress peak values of the medial and lateral parts of the asymmetric prosthesis were 15.81 MPa and 11.95 MPa,and those of the posterior stabilization prosthesis were 16.70 MPa and 13.76 MPa.The difference of Mises stress on the medial part was 5.33%,and the difference of Mises stress on the lateral part was 13.15%.Comparing the peak Mises stress on the femoral and tibial components,the asymmetric component was always lower than the posterior stable component during knee flexion.(3)In the upright position at 0 degrees,the medial contact area of the posterior stabilization prosthesis was 17.96 mm2,and the lateral contact area was 34.10 mm2.The contact area on the inner and outer sides of the asymmetric design prosthesis liner was 105.47 mm2 and 107.80 mm2,respectively,indicating a larger contact area with a smaller difference between the inner and outer sides.(4)These results suggest that the biomechanical performance of the asymmetric prosthesis is superior,contributing to the maintenance of knee joint stability and improved joint mobility.This design,to a certain extent,mimics the rotational motion mechanism of the knee joint about the medial condyle as an axis,making it a more effective choice for knee joint prosthesis selection.

BACKGROUND:With social progress,the incidence rate of knee osteoarthritis is getting higher and higher in the face of the rapidly developing aging problem in the social population,and the number of total knee replacement operations is gradually increasing. OBJECTIVE:To study the relationship between prosthesis size and stress shielding by improving the tibial prosthesis base. METHODS:A female patient with severe knee osteoarthritis was selected.Based on Mimics,through extracting the bone structure of the knee joint and simulating the total knee replacement surgery,osteotomy,positioning,and implantation operations were carried out to establish the geometric modeling of the total knee replacement prosthesis(including the femoral prosthesis,tibial bracket,and tibial pad),and improve the design of the tibial prosthesis base,analyze the effect of different tibial prosthesis bases on stress shielding of surrounding bone tissue. RESULTS AND CONCLUSION:(1)Compared with single-stem tibial intramedullary stem prosthesis,the design of four-post tibial intramedullary stem prosthesis created a certain degree of stress shielding around the short stem.However,compared with a thicker single long stem,this stress shielding effect was significantly reduced,and the load was evenly distributed among the four short stems,so there was no stress concentration at the bottom of the pile.(2)The design with a rectangular hole in the middle not only provided relatively good stability,but also helped to reduce stress shielding of cancellous bone to a certain extent,with a reduction rate of 77.5%.(3)Compared with a single-stem tibial intramedullary stem prosthesis,both the four-post tibial intramedullary stem prosthesis and the four-post tibial intramedullary stem prosthesis with a hole in the middle have good stability,which can reduce stress shielding to a certain extent without causing stress concentration,providing theoretical guidance for the design of the tibial intramedullary stem.

Objective:To develop and validate an artificial intelligence (AI) diagnostic model for coronary artery disease based on facial photos.Methods:This study was a cross-sectional study. Patients who were scheduled to undergo coronary angiography (CAG) at Beijing Anzhen Hospital and Beijing Daxing Hospital from August 2022 to November 2023 were included consecutively. Before CAG, facial photos were collected (including four angles: frontal view, left and right 60° profile, and top of the head). Photo datasets were randomly divided into a training set, a validation set (70%), and a testing set (30%). The model was constructed using Masked Autoencoder (MAE) and Vision Transformer (ViT) architectures. Firstly, the model base was pre-training using 2 million facial photos obtained from the publicly available VGGFace dataset, and fine-tuned by the training and validation sets; the model was validated in the test set. In addition, the ResNet architecture was used to process the dataset, and its outputs were compared with those of the models based on MAE and ViT. In the test set, the area under the operating characteristic curve ( AUC) of the AI model was calculated using CAG results as the gold standard. Results:A total of 5 974 participants aged 61 (54, 67) years were included, including 4 179 males (70.0%), with a total of 84 964 facial photos. There were 79 140 facial photos in the training and validation sets, with 3 822 patients with coronary artery disease; there were 5 824 facial photos in the test set, with 239 patients with coronary artery disease. The AUC value of the MAE and ViT model initialized with pre-training model weights was 0.841 and 0.824, respectively. The AUC of the ResNet model initialized with random weights was 0.810, while the AUC of the ResNet model initialized with pre-training model weights was 0.816. Conclusion:The AI model based on facial photos showes good diagnostic performance for coronary artery disease and holds promise for further application in early diagnosis.

Objective:This study aims to explore the temporal trend of Low Anterior Resection Syndrome (LARS) and its symptoms after laparoscopic anterior resection for rectal cancer.Methods:A retrospective cohort study design was employed. The study included primary rectal (adenocarcinoma) cancer patients who underwent laparoscopic anterior resection at Tongji Hospital, Huazhong University of Science and Technology, between January 1, 2010, and December 31, 2020. Complete medical records and follow-up data at 3, 6, 9, 12, and 18 months postoperatively were available for all patients. A total of 1454 patients were included, of whom 1094 (75.2%) were aged ≤65 years, and 597 (41.1%) were females. Among them, 1040 cases (71.5%) had an anastomosis-to-anus distance of 0-5cm, and 86 cases (5.9%) received neoadjuvant treatment. All patients completed the Chinese version of the LARS questionnaire and their LARS occurrence and specific symptom information were recorded at 3, 6, 9, 12, and 18 months postoperatively. Considering past literature and clinical experience, further subgroup analyses were performed to explore the potential impact factors on severe LARS, including anastomosis level, preoperative neoadjuvant therapy, postoperative adjuvant therapy, and the presence of preventive stoma.Results:The occurrence rates of LARS at 3, 6, 9, 12, and 18 months postoperatively were 78.5% (1142/1454), 71.4% (1038/1454), 55.0% (799/1454), 45.7% (664/1454), and 45.7% (664/1454), respectively (χ 2=546.180 , P<0.001). No statistically significant difference was observed between the 12-month and 18-month time points ( P>0.05). When compared with the symptoms at 3 months, the occurrence rates of gas incontinence [1.7% (24/1454) vs. 33.9% (493/1454)], liquid stool incontinence [3.9% (56/1454) vs. 41.9% (609/1454)], increased stool frequency [79.6% (1158/1454) vs. 95.9% (1395/1454)], stool clustering [74.3% (1081/1454) vs. 92.9% (1351/1454)], and stool urgency [46.5% (676/1454) vs. 78.7% (1144/1454)] in the LARS symptom spectrum were significantly alleviated at 12 months (all P<0.05) and remained stable beyond 12 months (all P>0.05). With the extension of postoperative time, the incidence rates of severe LARS exhibited a decreasing trend in different subgroups, of anastomosis level, preoperative neoadjuvant therapy, postoperative adjuvant therapy, and the presence of preventive stoma, and reached stability at 12 months postoperatively (all P>0.05). Conclusion:LARS and its specific symptom profile showed a trend of gradual improvement over time up to 1 year postoperatively, and stabilized after more than 1 year. Increased stool frequency and stool clustering are the most common features of abnormal bowel dys function, which improve slowly after surgery.

Objective:This study aims to explore the temporal trend of Low Anterior Resection Syndrome (LARS) and its symptoms after laparoscopic anterior resection for rectal cancer.Methods:A retrospective cohort study design was employed. The study included primary rectal (adenocarcinoma) cancer patients who underwent laparoscopic anterior resection at Tongji Hospital, Huazhong University of Science and Technology, between January 1, 2010, and December 31, 2020. Complete medical records and follow-up data at 3, 6, 9, 12, and 18 months postoperatively were available for all patients. A total of 1454 patients were included, of whom 1094 (75.2%) were aged ≤65 years, and 597 (41.1%) were females. Among them, 1040 cases (71.5%) had an anastomosis-to-anus distance of 0-5cm, and 86 cases (5.9%) received neoadjuvant treatment. All patients completed the Chinese version of the LARS questionnaire and their LARS occurrence and specific symptom information were recorded at 3, 6, 9, 12, and 18 months postoperatively. Considering past literature and clinical experience, further subgroup analyses were performed to explore the potential impact factors on severe LARS, including anastomosis level, preoperative neoadjuvant therapy, postoperative adjuvant therapy, and the presence of preventive stoma.Results:The occurrence rates of LARS at 3, 6, 9, 12, and 18 months postoperatively were 78.5% (1142/1454), 71.4% (1038/1454), 55.0% (799/1454), 45.7% (664/1454), and 45.7% (664/1454), respectively (χ 2=546.180 , P<0.001). No statistically significant difference was observed between the 12-month and 18-month time points ( P>0.05). When compared with the symptoms at 3 months, the occurrence rates of gas incontinence [1.7% (24/1454) vs. 33.9% (493/1454)], liquid stool incontinence [3.9% (56/1454) vs. 41.9% (609/1454)], increased stool frequency [79.6% (1158/1454) vs. 95.9% (1395/1454)], stool clustering [74.3% (1081/1454) vs. 92.9% (1351/1454)], and stool urgency [46.5% (676/1454) vs. 78.7% (1144/1454)] in the LARS symptom spectrum were significantly alleviated at 12 months (all P<0.05) and remained stable beyond 12 months (all P>0.05). With the extension of postoperative time, the incidence rates of severe LARS exhibited a decreasing trend in different subgroups, of anastomosis level, preoperative neoadjuvant therapy, postoperative adjuvant therapy, and the presence of preventive stoma, and reached stability at 12 months postoperatively (all P>0.05). Conclusion:LARS and its specific symptom profile showed a trend of gradual improvement over time up to 1 year postoperatively, and stabilized after more than 1 year. Increased stool frequency and stool clustering are the most common features of abnormal bowel dys function, which improve slowly after surgery.

Objective To explore the effect of improved total cavity endoscopy on lung function,postoperative feeding and complications in patients with chronic lung disease of esophageal cancer.Methods 120 esophageal cancer patients with chronic lung disease admitted to our hospital from September 2022 to June 2023 were randomly divided into two groups.The observation group consisted of 60 patients who underwent improved total cavity endoscopy assisted esophageal cancer resection,while the control group consisted of 60 patients who underwent traditional open surgery.The perioperative related indexes,lung function indexes[forced expiratory volume in the first second(FEV1),forced vital capacity(FVC),maximum ventilation volume(MVV)],inflammatory level[interleukin-6(IL-6),interleukin-8(IL-8),tumor necrosis factor(TNF-α)]were compared between the two groups.Results The blood loss,operation time,number of lymph node dissection and drainage time in the observation group were(329.51±78.84)ml,(175.47±10.41)min,(29.67±17.86)pieces per case and(3.14±0.98)d respectively.In the control group,the intraoperative blood loss,operation time,number of lymph node dissection and drainage time were(372.31±99.23)ml,(148.54±10.68)min,(28.36±18.15)pieces and(6.37±1.23)d,respectively,there was statistical significance between the two groups(P＜0.05).The FEV,,FVC and MVV of the observation group were(1.88±0.53)L,(2.33±0.46)L and(32.59±11.84)L,respectively.Two weeks after operation,the control group was(1.37±0.31)L,(1.75±0.38)L and(23.68±9.41)L respectively,there was statistical significance between the two groups(P＜0.05).The inflammatory factors IL-6,IL-8 and TNF-α in the observation group were(2.17±1.62)ng/ml,(2.09±1.52)ng/ml and(1.32±0.57)ng/ml,respectively.The control group were(3.06±1.52)ng/ml,(2.75±1.29)ng/ml and(1.73±0.75)ng/ml respectively,there was statistical significance between the two groups(P＜0.05).The incidence of postoperative complications in the observation group and the control group were 6.67％and 20.00％respectively,and patients in the observation group ate earlier than those in the control group(P＜0.05).Conclusion Compared with the traditional open surgery,the improved total laparoscopic surgery has the advantages of less trauma,simpler operation,less damage to lung function,significantly lower incidence of postoperative complications,and shorter postoperative eating time.

Objective To investigate the safety and efficacy of sodium fluorescein-guided microsurgery in children with medulloblastoma,and to analyze the surgical efficacy and prognosis.Among them,12 cases underwent unilateral telovelar approach,2 cases underwent bilateral telovelar approach,and 6 cases underwent telovelar approach combined with transvermian approach.The intraoperative dose of sodium fluorescein was 2 mg/kg.Methods The clinical data of 20 patients with medulloblastoma treated with fluorescein sodium assisted microsurgery from January 2018 to August 2023 in Xinjiang Autonomous Region People's Hospital were retrospectively analyzed.Results Of the 20 patients,12 were male and 8 were female.The mean age of onset was(7.9±3.7)years.In all cases,there was clear tumor fluorescence,none of the cases had adverse reaction associated with the use of sodium fluorescein.There were 16 cases of gross-total resection,3 cases of near-total resection,1 case of partial resection,1 case of intracranial infection,2 case of subcutaneous effusion,2 cases of cerebellar mutism.The follow-up time was from 3 to 72 months.5 cases did not receive sufficient radiotherapy and chemotherapy,and 9 cases died due to tumor progression or recurrence.In all cases,the longest overall survival was 72 months,the mean survival time was 39.2 months,and the median survival time was 41.2 months.Conclusion Fluorescein sodium assisted microsurgery is safe and effective in pediatric medulloblastoma surgery.

Objective:To investigate the potential effect and mechanism of docosahexaenoic acid(DHA) on hippocampal neuronal apoptosis and c-Jun N-terminal kinase(JNK) protein in rats with subarachnoid hemorrhage(SAH).Methods:Forty eight SPF-grade male SD rats were randomly divided into control group, sham group, model group and DHA intervention group according to the random number table method, with 12 rats in each group.The rats in model group and DHA group were injected with autologous blood(0.3 mL) into the optic chiasma to establish the SAH model.Rats in model group were intraperitoneally injected with DHA(35 mg/kg) 3 hours after SAH model establishment, rats in sham operation group were injected with 0.3 mL 0.9% sodium chloride solution into the optic chiasma, and rats in control group were fed normally.Neurobehavioral function of all rats was evaluated after 24 hours.The apoptosis of neuron was observed by TUNEL staining, and the expression of phosphorylated JNK(p-JNK)and apoptosis-related proteins Bax and Bcl-2 was observed by Western blot.Statistical analysis was performed using GraphPad Prism 7.0 software.One-way ANOVA was used for comparison among multiple groups, and Tukey test was used for further pairwise comparison.Results:(1)The differences in neurobehavioral function scores among the 4 groups of rats were statistically significant( F=103.60, P<0.05), the neurobehavioral function scores in model group(8.67±1.37) and DHA intervention group(13.67±1.51) were lower than that in control group(18.00±0.00) and sham group(17.67±0.52)( all P<0.05), while the neurobehavioral function score in DHA intervention group was higher than that in the model group( P<0.05).(2)The results of TUNEL staining showed that there were statistical differences in the number of hippocampal neuron apoptosis among the 4 groups( F=30.76, P<0.05), the number of hippocampal neuron apoptosis in model group(55.67±5.28) was higher than those in control group(25.83±7.06) and sham group(25.50±6.72) (both P<0.05), the number of hippocampal neuron apoptosis in DHA intervention group(35.17±5.78) was lower than that in model group.(3)The results of Western blot showed that there were no statistical differences in the Bax protein levels among the four groups( F=2.00, P>0.05).There were statistical differences in the expression levels of Bcl-2, p-JNK and Bax/Bcl-2 ratio among the 4 groups( F=8.48, 5.69, 5.39, all P<0.05).There was no statistical difference in Bcl-2, p-JNK protein levels and Bax/Bcl-2 ratio between the control group and sham group(all P>0.05).The p-JNK protein levels and Bax/Bcl-2 ratio in model group ((1.93±0.25), (2.05±0.86)) were higher than those in sham group ((1.42±0.33), (1.05±0.26)) (both P<0.05), the Bcl-2 protein level in model group (1.04±0.23) was lower than that in sham group (1.61±0.16) ( P<0.05).The p-JNK protein level and Bax/Bcl-2 ratio in DHA intervention group((1.43±0.33), (1.19±0.30)) were lower than those in model group(both P<0.05), the Bcl-2 protein level in DHA intervention group(1.42±0.28) was higher than that in model group( P<0.05). Conclusion:DHA can reduce neuronal apoptosis, inhibit the activation of p-JNK and improve neurological function of SAH model rats.

Objective To analyze the impact of artificial intelligence (AI) on colorectal adenoma detection rate (ADR) in fatigue state of endoscopists. Methods A total of 784 patients undergoing colonoscopy at the Endoscopy Center of Hengshui People's Hospital in Hebei Province were enrolled. Patients were divided into group A (n=405, time from 14: 00 to 15: 59) and group B (n=379, time from 16: 00 to 17: 30) based on the operation time. Patients in both groups who underwent AI-assisted examination were included in AI subgroup, while those without AI assistance were included in non-AI subgroup. Baseline data, including age, gender and bowel preparation quality [assessed by the Boston Bowel Preparation Scale (BBPS) score] were collected. The ADR and polyp detection rate (PDR) for colorectal lesions were calculated for both groups, and the ADR was compared between groups with and without AI assistance. Results The overall ADR was 32.10% in the group A, which was higher than 26.91% in the group B, but the difference was not statistically significant (P>0.05). Without AI assistance, the ADR in the group A was 25.85%, which was significantly higher than 17.30% in the group B (P < 0.05). In the group B with AI assistance, the ADR was significantly higher than that in the group A without AI assistance (P < 0.05). Without AI assistance, the PDR in the group A was 33.17%, which was significantly higher than 22.70% in the group B (P < 0.05). After using AI assistance, there was no significant difference in PDR between the two groups (P>0.05). In the group A, the ADR was 38.50% in the AI subgroup (n=200) and 25.80% in the non-AI subgroup (n=205), with a statistically significant difference (P=0.006). In the group B, the ADR was 36.08% in the AI subgroup (n=194) and 17.30% in the non-AI subgroup (n=185), with a statistically significant difference (P < 0.001). Conclusion AI-assisted colonoscopy can effectively improve the ADR of endoscopists under fatigue conditions.

Two Hofmann-Martius-like rearrangement products generated in the production of duloxetine hydrochloride were studied. The structures and generation mechanism of the two Hofmann-Martius rearrangement products were analyzed by LC-MS and NMR. The results showed that under the acidic conditions, the naphthol ether bond of duloxetine would break down and the intermediates of naphthol and the alkyl thiophene cation was generated; the two Hofmann-Martius-like rearrangement products were proven to be a pair of isomers produced by nucleophilic substitution between the naphthol intermediate state and the alkyl thiophene cation intermediate state at the ortho or the para position, respectively. The production of two isomers was related to the strong acidic and protic solvent environment. Therefore, in the salting process of duloxetine hydrochloride, the pH value should be controlled in the range of 3-7 and temperature should be maintained below 50 °C, as well as the nonprotic solvent acetone is chosen to avoid generation of the two isomers.