The accurate segmentation of breast ultrasound images is an important precondition for the lesion determination. The existing segmentation approaches embrace massive parameters, sluggish inference speed, and huge memory consumption. To tackle this problem, we propose T ²KD Attention U-Net (dual-Teacher Knowledge Distillation Attention U-Net), a lightweight semantic segmentation method combined double-path joint distillation in breast ultrasound images. Primarily, we designed two teacher models to learn the fine-grained features from each class of images according to different feature representation and semantic information of benign and malignant breast lesions. Then we leveraged the joint distillation to train a lightweight student model. Finally, we constructed a novel weight balance loss to focus on the semantic feature of small objection, solving the unbalance problem of tumor and background. Specifically, the extensive experiments conducted on Dataset BUSI and Dataset B demonstrated that the T ²KD Attention U-Net outperformed various knowledge distillation counterparts. Concretely, the accuracy, recall, precision, Dice, and mIoU of proposed method were 95.26%, 86.23%, 85.09%, 83.59%and 77.78% on Dataset BUSI, respectively. And these performance indexes were 97.95%, 92.80%, 88.33%, 88.40% and 82.42% on Dataset B, respectively. Compared with other models, the performance of this model was significantly improved. Meanwhile, compared with the teacher model, the number, size, and complexity of student model were significantly reduced (2.2×10 ⁶ vs. 106.1×10 ⁶, 8.4 MB vs. 414 MB, 16.59 GFLOPs vs. 205.98 GFLOPs, respectively). Indeedy, the proposed model guarantees the performances while greatly decreasing the amount of computation, which provides a new method for the deployment of clinical medical scenarios.
Humans ; Breast Neoplasms/diagnostic imaging* ; Female ; Ultrasonography, Mammary/methods* ; Image Processing, Computer-Assisted/methods* ; Algorithms ; Neural Networks, Computer ; Breast/diagnostic imaging*

Objective:To understand the contract renewal willingness and its influencing factors among rural order-oriented medical students in Shaanxi Province. M ethods This study employed an explanatory sequential mixed methods design to examine contract renewal patterns among rural order-oriented medical graduates. From February to July 2024, a questionnaire survey was conducted among rural order-oriented medical students who graduated from 2015 to 2023 in Shaanxi Province. The participants were first stratified into three strata based on their year of graduation and stage of service, and one-third of each stratum was randomly selected as the research subjects. Univariate and multivariate analysis methods were used to explore the influencing factors of their willingness to renew their service in rural areas. Secondly, qualitative research methods were employed to conduct thematic interviews with 36 targeted medical students on the influencing factors of their willingness to renew their service. Results:A total of 513 valid questionnaires were collected during the quantitative research phase, including 224 males and 289 females. Of these, 14 were from the 2015-2017 cohort, 247 from the 2018-2020 cohort, and 252 from the 2021-2023 cohort. The results showed that only 30.4%(156/513) of the orientation medical students were willing to practice in primary care after the period of service. Univariate analysis showed that there were six factors related to the willingness to renew the contract, the consistency of the source and implementation of the contract, the completion of the standardized training of residents, the satisfaction with primary work, professional identity, the ability of primary diagnosis and treatment, and the training system and the suitability of primary work. Multivariate analysis showed that the willingness to renew the contract was significantly higher in the students who had the same place of origin and the place of performance( OR=1.7, 95% CI: 1.1-2.6, P=0.022). The willingness to renew the contract was significantly higher among students who participated in the standardized residency training than those who completed the training( OR=2.0, 95% CI: 1.3-3.0, P=0.003), and students with a better fit between the training system and working in primary care were more likely to renew their contract( OR=4.1, 95% CI: 2.8-6.0, P<0.001). Four themes were extracted from the interview: subjective factors, objective environment, policy factors and other factors. Conclusions:The study shows that improving the consistency of the source of students and the implementation of the contract, strengthening the standardized training of residents, and optimizing the adaptation of the training system to the primary work are the key measures to improve the willingness of directional medical students to renew their contract at the primary level.

The specific mechanisms of interferon regulatory factor 8(IRF8)in porcine intestinal in-nate immunity and resistance to enteric virus infection remain to be elucidated.To investigate the immunoregulatory role of IRF8,establishing an IRF8 gene knockout porcine intestinal epithelial cell(IPEC-J2)monoclonal cell line is of significant importance.This study initially aimed to obtain recombinant adeno-associated virus rAAV-sgIRF8-eGFP capable of knocking out the IRF8 gene through co-transfection of HEK-293T cells with three plasmids.Subsequently,IPEC-J2 cells were infected with the virus,and those expressing eGFP were selected by flow cytometry and cultured to form monoclonal cell lines.These cell lines were then identified by Sanger sequencing and West-ern blot techniques.Lastly,qPCR analysis was used to measure the expression levels of interferon factors IFN-α,IFN-β,IFN-γ and IFN-λ,providing preliminary insights into the impact of IRF8 gene knockout on IPEC-J2 cell immunity.The results demonstrated successful generation of rAAV-sgIRF8-eGFP,which successfully infected IPEC-J2 cells leading to eGFP fluorescence.Flow cytometry followed by cell culture led to the establishment of two monoclonal cell lines,IRF8-KO1 and IRF8-KO3.Sanger sequencing revealed a five-base deletion in IRF8-KO1 and a seven-base dele-tion in IRF8-KO3.Western blot confirmed the absence of IRF8 protein expression in IRF8-KO1,making it an ideal candidate monoclonal cell line.qPCR analysis of interferon factors indicated sig-nificant decrease in IFN-γ(P＜0.05)and IFN-λ(P＜0.01)transcription level in IRF8-knockout cells,while the transcription levels of IFN-α and IFN-β remained relatively unchanged.This study successfully established an IRF8 gene knockout IPEC-J2 monoclonal cell line,providing a founda-tion for further research on IRF8-related porcine intestinal immune regulation and mechanisms of intestinal virus infection.

BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.

The specific mechanisms of interferon regulatory factor 8(IRF8)in porcine intestinal in-nate immunity and resistance to enteric virus infection remain to be elucidated.To investigate the immunoregulatory role of IRF8,establishing an IRF8 gene knockout porcine intestinal epithelial cell(IPEC-J2)monoclonal cell line is of significant importance.This study initially aimed to obtain recombinant adeno-associated virus rAAV-sgIRF8-eGFP capable of knocking out the IRF8 gene through co-transfection of HEK-293T cells with three plasmids.Subsequently,IPEC-J2 cells were infected with the virus,and those expressing eGFP were selected by flow cytometry and cultured to form monoclonal cell lines.These cell lines were then identified by Sanger sequencing and West-ern blot techniques.Lastly,qPCR analysis was used to measure the expression levels of interferon factors IFN-α,IFN-β,IFN-γ and IFN-λ,providing preliminary insights into the impact of IRF8 gene knockout on IPEC-J2 cell immunity.The results demonstrated successful generation of rAAV-sgIRF8-eGFP,which successfully infected IPEC-J2 cells leading to eGFP fluorescence.Flow cytometry followed by cell culture led to the establishment of two monoclonal cell lines,IRF8-KO1 and IRF8-KO3.Sanger sequencing revealed a five-base deletion in IRF8-KO1 and a seven-base dele-tion in IRF8-KO3.Western blot confirmed the absence of IRF8 protein expression in IRF8-KO1,making it an ideal candidate monoclonal cell line.qPCR analysis of interferon factors indicated sig-nificant decrease in IFN-γ(P＜0.05)and IFN-λ(P＜0.01)transcription level in IRF8-knockout cells,while the transcription levels of IFN-α and IFN-β remained relatively unchanged.This study successfully established an IRF8 gene knockout IPEC-J2 monoclonal cell line,providing a founda-tion for further research on IRF8-related porcine intestinal immune regulation and mechanisms of intestinal virus infection.

BACKGROUND:Osteonecrosis is an orthopedic disease that severely limits joint function,with complex pathogenesis involving multiple risk factors.Cathepsins,as a class of enzymes that play a key role in bone metabolism,are closely related to the proliferation,differentiation of bone cells,and remodeling of the bone matrix.However,previous studies have mostly focused on descriptive analyses,lacking direct evidence of causal relationships.OBJECTIVE:To clarify the potential causal relationship between cathepsins and osteonecrosis and to explore their possible mechanisms by analyzing large-scale sample data from the FinnGen database.METHODS:We obtained osteonecrosis-related data from the FinnGen database,including R9(a total of 359 399 samples:1 385 cases and 358 014 controls)and R10 versions(a total of 392 580 samples:1 543 cases and 391 037 controls).Single nucleotide polymorphisms associated with nine cathepsins(cathepsin B,E,F,G,H,O,S,L2,and Z)were acquired from a previous study(3 301 individuals).Univariate Mendelian randomization,reverse univariate Mendelian randomization,and multivariate Mendelian randomization analyses were conducted using the inverse variance weighted method,MR-Egger method,weighted median method,simple mode method,and weighted mode method.Initially,Mendelian randomization analysis was performed using osteonecrosis data from R9.Additionally,sensitivity analyses were conducted using Cochran's Q test,MR-Egger intercept,MR-PRESSO global test,and leave-one-out analysis to check for horizontal pleiotropy and heterogeneity.Subsequently,a validation analysis study was carried out on the R10 dataset,and a meta-analysis was conducted to combine the two datasets to explore the joint effect.RESULTS AND CONCLUSION:Univariate Mendelian randomization analysis results showed that higher levels of cathepsin B were significantly associated with a reduced risk of osteonecrosis(inverse variance weighted:odds ratio(OR)=0.865,95％confidence interval(CI):0.762-0.982,P=0.025),and no reverse causal relationship was found between the nine cathepsins and osteonecrosis(P＞0.05).These associations were validated by meta-analysis.Multivariate analysis,using the nine cathepsins as covariates,revealed a reverse causal relationship between the levels of cathepsin Band the risk of osteonecrosis(inverse variance weighted:OR=0.8710,95％CI:0.761-0.997,P=0.045),consistent with the results before adjustment.Sensitivity analyses based on heterogeneity and horizontal pleiotropy suggested that the results were relatively robust.This study suggests that there is a causal relationship between high levels of cathepsin B and the reduced risk of osteonecrosis,and it may serve as a biomarker for osteonecrosis,providing new directions and insights for the diagnosis and treatment of osteonecrosis.Although this study is based on data analysis of European populations,these findings have important implications for Chinese biomedical research,especially in understanding disease mechanisms,developing biomarkers,and formulating treatment strategies.They also encourage similar studies conducted on Chinese populations to explore the impact of racial and genetic background differences on the occurrence of osteonecrosis.

Objective:To understand the contract renewal willingness and its influencing factors among rural order-oriented medical students in Shaanxi Province. M ethods This study employed an explanatory sequential mixed methods design to examine contract renewal patterns among rural order-oriented medical graduates. From February to July 2024, a questionnaire survey was conducted among rural order-oriented medical students who graduated from 2015 to 2023 in Shaanxi Province. The participants were first stratified into three strata based on their year of graduation and stage of service, and one-third of each stratum was randomly selected as the research subjects. Univariate and multivariate analysis methods were used to explore the influencing factors of their willingness to renew their service in rural areas. Secondly, qualitative research methods were employed to conduct thematic interviews with 36 targeted medical students on the influencing factors of their willingness to renew their service. Results:A total of 513 valid questionnaires were collected during the quantitative research phase, including 224 males and 289 females. Of these, 14 were from the 2015-2017 cohort, 247 from the 2018-2020 cohort, and 252 from the 2021-2023 cohort. The results showed that only 30.4%(156/513) of the orientation medical students were willing to practice in primary care after the period of service. Univariate analysis showed that there were six factors related to the willingness to renew the contract, the consistency of the source and implementation of the contract, the completion of the standardized training of residents, the satisfaction with primary work, professional identity, the ability of primary diagnosis and treatment, and the training system and the suitability of primary work. Multivariate analysis showed that the willingness to renew the contract was significantly higher in the students who had the same place of origin and the place of performance( OR=1.7, 95% CI: 1.1-2.6, P=0.022). The willingness to renew the contract was significantly higher among students who participated in the standardized residency training than those who completed the training( OR=2.0, 95% CI: 1.3-3.0, P=0.003), and students with a better fit between the training system and working in primary care were more likely to renew their contract( OR=4.1, 95% CI: 2.8-6.0, P<0.001). Four themes were extracted from the interview: subjective factors, objective environment, policy factors and other factors. Conclusions:The study shows that improving the consistency of the source of students and the implementation of the contract, strengthening the standardized training of residents, and optimizing the adaptation of the training system to the primary work are the key measures to improve the willingness of directional medical students to renew their contract at the primary level.

Objective:To determine the causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema using Mendelian randomization (MR) analyses.Methods:This study was a secondary data analysis based on the summary data of genome-wide association studies (GWAS), which involved 293 723 participants (educational attainment) from the Social Science Genetics Association Consortium and 462 013 participants [allergic rhinitis and (or) eczema] from the UK Biobank. Genetic variants that were closely related to educational attainment were identified as instrumental variables. Two-sample MR analyses, including inverse-variance weighted (IVW), MR-Egger regression, weighted median method and weighted model-based estimation, were performed to investigate the causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema, in which the odds ratio ( OR) values were used as indicators. Results:A total of 70 single-nucleotide polymorphisms (SNPs) were chosen as instrumental variables. The MR-Egger regression results suggested that the genetic pleiotropy was unlikely to bias our results ( P=0.107). In the univariable MR analyses, IVW regression showed that the risk of allergic rhinitis and (or) eczema was OR=1.044 (95% CI: 1.020-1.069, P<0.001) and OR=1.170 (95% CI: 1.074-1.256, P<0.001), respectively, for the increase in the duration of education by one year or one standard deviation ( SD) (3.71 years). In the reverse MR analysis, IVW regression showed little evidence that allergic rhinitis and (or) eczema affected educational attainment ( OR=1.020, 95% CI: 0.927-1.023, P=0.683). The results of the weighted median method and weighted mode-based estimation were consistent with the results of IVW. Conclusion:This study suggests that there is a positive causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema, which means that educational attainment can increase the occurrence of allergic rhinitis and (or) eczema.

Objective:To determine the causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema using Mendelian randomization (MR) analyses.Methods:This study was a secondary data analysis based on the summary data of genome-wide association studies (GWAS), which involved 293 723 participants (educational attainment) from the Social Science Genetics Association Consortium and 462 013 participants [allergic rhinitis and (or) eczema] from the UK Biobank. Genetic variants that were closely related to educational attainment were identified as instrumental variables. Two-sample MR analyses, including inverse-variance weighted (IVW), MR-Egger regression, weighted median method and weighted model-based estimation, were performed to investigate the causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema, in which the odds ratio ( OR) values were used as indicators. Results:A total of 70 single-nucleotide polymorphisms (SNPs) were chosen as instrumental variables. The MR-Egger regression results suggested that the genetic pleiotropy was unlikely to bias our results ( P=0.107). In the univariable MR analyses, IVW regression showed that the risk of allergic rhinitis and (or) eczema was OR=1.044 (95% CI: 1.020-1.069, P<0.001) and OR=1.170 (95% CI: 1.074-1.256, P<0.001), respectively, for the increase in the duration of education by one year or one standard deviation ( SD) (3.71 years). In the reverse MR analysis, IVW regression showed little evidence that allergic rhinitis and (or) eczema affected educational attainment ( OR=1.020, 95% CI: 0.927-1.023, P=0.683). The results of the weighted median method and weighted mode-based estimation were consistent with the results of IVW. Conclusion:This study suggests that there is a positive causal relationship between educational attainment and the risk of allergic rhinitis and (or) eczema, which means that educational attainment can increase the occurrence of allergic rhinitis and (or) eczema.

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.