Objective:To investigate the feasibility and optimal expansion width of replacing the left anterior descending coronary artery (LADCA) with the region of heart sparing (RHS) to reduce cardiac radiation dose during breast cancer radiotherapy.Methods:Retrospective analysis was conducted on data from 88 patients with left-sided breast cancer who underwent radiotherapy at 2 centers: Nanfang Hospital of Southern Medical University (50 cases for the training set, 15 cases for the internal test set) and Ganzhou Hospital of Nanfang Hospital (23 cases for the external test set) from March 2022 to January 2024. All patients had left-sided invasive ductal carcinoma with axillary lymph node metastasis, and had undergone modified radical mastectomy and chemotherapy. Based on simulation CT images, 2 radiation oncologists delineated the LADCA and 8 RHSs. The RHSs were delineated by expanding the LADCA contour by 0.5 cm increments, totaling 8 expansions. The RHS widths were defined as 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 cm. The nnU-Net model was trained for 3D automatic segmentation of the LADCA and RHSs. Model performance was evaluated using the Dice similarity coefficient (DSC), relative volume error (RVE), sensitivity, specificity, and 95% Hausdorff distance (HD95). Additionally, the minimum, maximum, and average relative dose variations (RDV) as well as V5% and V20% indicators were calculated for the LADCA and each RHS. Correlation analysis was performed using the least squares regression, with the slope and coefficient of determination ( R2) employed to evaluate the accuracy of the model fitting, the relationship between the LADCA and RHS, and the degree of their correlation, thereby assessing the substitutive effect of the RHS for the LADCA. Results:The DSC for the LADCA was 0.415, while the DSCs for RHS widths of 0.5 cm and 4.0 cm were 0.718 and 0.835, respectively. Overall, the automatic segmentation performance improved with increasing RHS width. The DSC, RVE, sensitivity, specificity, and HD95 for the external test set were largely consistent with those of the internal test set, demonstrating the model's good robustness across different datasets. All RDVmin values were negative, while RDVmax and RDVmean showed a positive correlation with RHS width. RDVmean increased from 39.01% to 75.89% as the RHS width increased. In the correlation analysis, the slopes for RHS widths of 1.5 cm and 2.0 cm were 0.95 and 1.05, respectively, with R2 values and coefficients of variation of 0.79 and 0.73, and 21.11% and 24.03%, respectively. Conclusions:The automatic segmentation model trained on nnU-Net can accurately segment RHSs. Based on geometric and dosimetric indicators, a 1.5 cm-wide RHS is the most suitable substitute for the LADCA, effectively limiting the radiation dose to the LADCA without compromising target dose coverage.

Objective:To propose a semi-supervised learning method for dynamic generation of organ geometric contours, leveraging bladder volume variations and its relative position to the uterus to accurately generate uterine contours in cervical cancer radiotherapy.Methods:A total of 120 sets of pelvic planning CT images (including both full and empty bladder scans) from 60 patients with cervical cancer treated at the Department of Radiation Oncology, Nanfang Hospital of Southern Medical University between January and December 2023 were retrospectively collected. A conditional generative adversarial network (CGAN) based on a squeeze-and-excitation channel attention mechanism was proposed to accurately generate uterine geometric contours under varying bladder filling states. By emphasizing the critical spatial relationships between the bladder and uterus, the model learned the relative anatomical positions of pelvic organs and their motion correlations. The generative performance was quantitatively evaluated using the average Dice similarity coefficient (DSC), intersection over union (IoU), and the 95 th percentile Hausdorff distance (HD95), and was compared with GAN model, CGAN model, and Pix2Pix model. Pairwise comparisons were perfomed by paired-sample t-test. Results:The proposed SE-CGAN model achieved the best performance on the test set, with DSC of 0.83±0.09, IoU of 0.71±0.05, HD95 of (6.74±1.23) mm, improving DSC by 7.5%, 4.9%, and 3.6% compared to the GAN, CGAN, and Pix2Pix models, respectively (all P<0.001), and reducing the mean HD95 by 32.9%-45.3%. Statistical analysis revealed significant differences between SE-CGAN model and the other 3 baseline models, whereas no significant difference was observed between CGAN model and Pix2Pix model. The visualization results further demonstrated that the GAN model produced uterine contours deviated greatly from the real shape, and the edge was fuzzy; CGAN and Pix2Pix model achieved better overlap but lacked of precision in boundary reconstruction. In contrast, the contours generated by SE-CGAN model closely matched the ground truth with clearly defined edges, indicating superior reconstruction accuracy. Conclusions:In this study, we propose a generative adversarial network method that establishes a dynamic modulation mechanism by which the bladder state influences the uterine geometric contour, enabling accurate generation of the uterine contours from the bladder contours of any given localization CT scan. This approach effectively addresses the uncertainty in radiotherapy target delineation caused by pelvic organ motion.

Objective To investigate the effect of active muscle response on mechanical responses and injuries of human neck under high Gx loading.Methods A refined finite element model of the head and neck with active muscle response was established and validated based on the existing post-crash volunteer experiments.The effects of active muscle action on the kinematic and biomechanical responses of the neck were investigated under different G-value loads and at each tilting angle using this model.Results The stress distribution of vertebrae under high Gx load was dispersed from C4-7 to the whole vertebrae,and the active muscle action reduced the stress change,and the effect was significant under 8 G acceleration,which reduced the peak vertebral bone stress by 23.6％and 11.6％,and the peak intervertebral disc stress by 42.3％and 63.4％under 8 G and 10 G conditions,respectively.The maximum stress difference of 34.3 MPa was achieved by the active muscle action at 15° backward tilting.Conclusions The neck showed better stability by the active muscle action under the impact of high Gx loading.At different tilting angles,the active muscle action was more obvious in the backward tilting posture compared with the forward tilting and upright seated postures,and the backward tilting posture was safer to meet the impact when the same active muscle action was applied.The results can provide a reference for the subsequent studies related to the neck injury.

Objective To investigate the effect of active muscle response on mechanical responses and injuries of human neck under high Gx loading.Methods A refined finite element model of the head and neck with active muscle response was established and validated based on the existing post-crash volunteer experiments.The effects of active muscle action on the kinematic and biomechanical responses of the neck were investigated under different G-value loads and at each tilting angle using this model.Results The stress distribution of vertebrae under high Gx load was dispersed from C4-7 to the whole vertebrae,and the active muscle action reduced the stress change,and the effect was significant under 8 G acceleration,which reduced the peak vertebral bone stress by 23.6％and 11.6％,and the peak intervertebral disc stress by 42.3％and 63.4％under 8 G and 10 G conditions,respectively.The maximum stress difference of 34.3 MPa was achieved by the active muscle action at 15° backward tilting.Conclusions The neck showed better stability by the active muscle action under the impact of high Gx loading.At different tilting angles,the active muscle action was more obvious in the backward tilting posture compared with the forward tilting and upright seated postures,and the backward tilting posture was safer to meet the impact when the same active muscle action was applied.The results can provide a reference for the subsequent studies related to the neck injury.

Objective:To investigate the feasibility and optimal expansion width of replacing the left anterior descending coronary artery (LADCA) with the region of heart sparing (RHS) to reduce cardiac radiation dose during breast cancer radiotherapy.Methods:Retrospective analysis was conducted on data from 88 patients with left-sided breast cancer who underwent radiotherapy at 2 centers: Nanfang Hospital of Southern Medical University (50 cases for the training set, 15 cases for the internal test set) and Ganzhou Hospital of Nanfang Hospital (23 cases for the external test set) from March 2022 to January 2024. All patients had left-sided invasive ductal carcinoma with axillary lymph node metastasis, and had undergone modified radical mastectomy and chemotherapy. Based on simulation CT images, 2 radiation oncologists delineated the LADCA and 8 RHSs. The RHSs were delineated by expanding the LADCA contour by 0.5 cm increments, totaling 8 expansions. The RHS widths were defined as 0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0 cm. The nnU-Net model was trained for 3D automatic segmentation of the LADCA and RHSs. Model performance was evaluated using the Dice similarity coefficient (DSC), relative volume error (RVE), sensitivity, specificity, and 95% Hausdorff distance (HD95). Additionally, the minimum, maximum, and average relative dose variations (RDV) as well as V5% and V20% indicators were calculated for the LADCA and each RHS. Correlation analysis was performed using the least squares regression, with the slope and coefficient of determination ( R2) employed to evaluate the accuracy of the model fitting, the relationship between the LADCA and RHS, and the degree of their correlation, thereby assessing the substitutive effect of the RHS for the LADCA. Results:The DSC for the LADCA was 0.415, while the DSCs for RHS widths of 0.5 cm and 4.0 cm were 0.718 and 0.835, respectively. Overall, the automatic segmentation performance improved with increasing RHS width. The DSC, RVE, sensitivity, specificity, and HD95 for the external test set were largely consistent with those of the internal test set, demonstrating the model's good robustness across different datasets. All RDVmin values were negative, while RDVmax and RDVmean showed a positive correlation with RHS width. RDVmean increased from 39.01% to 75.89% as the RHS width increased. In the correlation analysis, the slopes for RHS widths of 1.5 cm and 2.0 cm were 0.95 and 1.05, respectively, with R2 values and coefficients of variation of 0.79 and 0.73, and 21.11% and 24.03%, respectively. Conclusions:The automatic segmentation model trained on nnU-Net can accurately segment RHSs. Based on geometric and dosimetric indicators, a 1.5 cm-wide RHS is the most suitable substitute for the LADCA, effectively limiting the radiation dose to the LADCA without compromising target dose coverage.

Objective:To propose a semi-supervised learning method for dynamic generation of organ geometric contours, leveraging bladder volume variations and its relative position to the uterus to accurately generate uterine contours in cervical cancer radiotherapy.Methods:A total of 120 sets of pelvic planning CT images (including both full and empty bladder scans) from 60 patients with cervical cancer treated at the Department of Radiation Oncology, Nanfang Hospital of Southern Medical University between January and December 2023 were retrospectively collected. A conditional generative adversarial network (CGAN) based on a squeeze-and-excitation channel attention mechanism was proposed to accurately generate uterine geometric contours under varying bladder filling states. By emphasizing the critical spatial relationships between the bladder and uterus, the model learned the relative anatomical positions of pelvic organs and their motion correlations. The generative performance was quantitatively evaluated using the average Dice similarity coefficient (DSC), intersection over union (IoU), and the 95 th percentile Hausdorff distance (HD95), and was compared with GAN model, CGAN model, and Pix2Pix model. Pairwise comparisons were perfomed by paired-sample t-test. Results:The proposed SE-CGAN model achieved the best performance on the test set, with DSC of 0.83±0.09, IoU of 0.71±0.05, HD95 of (6.74±1.23) mm, improving DSC by 7.5%, 4.9%, and 3.6% compared to the GAN, CGAN, and Pix2Pix models, respectively (all P<0.001), and reducing the mean HD95 by 32.9%-45.3%. Statistical analysis revealed significant differences between SE-CGAN model and the other 3 baseline models, whereas no significant difference was observed between CGAN model and Pix2Pix model. The visualization results further demonstrated that the GAN model produced uterine contours deviated greatly from the real shape, and the edge was fuzzy; CGAN and Pix2Pix model achieved better overlap but lacked of precision in boundary reconstruction. In contrast, the contours generated by SE-CGAN model closely matched the ground truth with clearly defined edges, indicating superior reconstruction accuracy. Conclusions:In this study, we propose a generative adversarial network method that establishes a dynamic modulation mechanism by which the bladder state influences the uterine geometric contour, enabling accurate generation of the uterine contours from the bladder contours of any given localization CT scan. This approach effectively addresses the uncertainty in radiotherapy target delineation caused by pelvic organ motion.

Objective To analyze the research status, hotspots of biofilms and periodontitis from 2013 to 2023 by bibliometric methods. Methods The literatures related to biofilms and periodontitis were searched in the Web of Science (Wos) database, and visualization software such as VOSviewer and CiteSpace were used to analyze the countries or regions, authors, institutions, journals and keywords. Results A total of 1 821 papers were included, and the results showed that the number of published papers increased year by year. The top three countries with the highest number of publications were the United States, Brazil and China; the top three institutions were Universidade de São Paulo, Harvard University and Forsyth Institute; the authors with the highest number of publications were Feres and Magda; among the top ten journals in terms of the number of publications, Journal of Periodontology had the highest number of publications (87 papers), followed by Plos One (69 papers) and Clinical Oral Investigations (51 papers). Oxidative stress, markers, adjunctive therapy and drug delivery were the main research hotspots; the frontiers mainly focused on quorum sensing, photodynamic therapy, reactive oxygen species, copper nanoparticles, and optical coherence tomography. Conclusion Researches on biofilms and periodontitis are growing year by year, and future research directions can focus on oxidative stress, adjuvant therapies, quorum sensing and photodynamic therapy.

Objective:To investigate the clinical characteristics and survival prognosis of patients with triple/quad-class exposed relapsed or refractory multiple myeloma(RRMM).Methods:The clinical data of patients with triple/quad-class exposed RRMM from eight centers in Shanxi Province between May 2017 and May 2024 were retrospectively analyzed.Overall survival(OS)and progression-free survival(PFS)were analyzed using the Kaplan-Meier method,and factors affecting survival were examined by the Cox proportional hazards model and Log-rank test.Results:Among the 112 patients with triple-class exposure,16 were quadruple-class exposed.The detection rates of high-risk cytogenetic abnormalities and extramedullary lesions in patients with triple-class exposure were 57.1%and 36.6%,respectively,while those in patients with quadruple-class exposure were 87.5%and 62.5%,respectively.The median PFS and OS of patients with triple-class expos-ure were 5.6 months and 12.2 months,respectively,while those of patients with quadruple-class exposure were 9.4 months and 16.9 months,respectively.Cox model analysis showed that extramedullary lesions and multi-line treatment(≥3 lines)were independent risk factors for the survival of patients with triple-class exposed RRMM(P<0.05).Previous autologous stem cell transplantation,subsequent con-ventional drug treatment,and B-cell maturation antigen(BCMA)chimeric antigen receptor T-cell(CAR-T)treatment were protective factors(P<0.05).After triple-class drug resistance,the Log-rank test verified that BCMA CAR-T treatment significantly prolonged the median PFS of patients compared to conventional drug treatment(9.4 months vs.5.2 months,P=0.026 9),whereas the difference in OS was not statistic-ally significant(16.9 months vs.7.9 months,P=0.263 4).Conclusions:Patients with triple/quad-class exposed RRMM have a poor prognosis,and BCMA CAR-T cell therapy can improve survival in patients with triple-class drug-resistant RRMM.

OBJECTIVE To analyze the distribution characteristics of allergens in patients with allergic rhinitis(AR)in Ningbo,so as to provide a reference for the scientific and accurate prevention and treatment of AR.METHODS A retrospective collection was performed for 2 329 AR patients with typical clinical symptoms who underwent serum allergen specific immunoglobulin E(sIgE)testing in the Department of Otolaryngology Head and Neck Surgery of the First Affiliated Hospital of Ningbo University from May 2021 to April 2024,and compared the distribution of positive rates of inhaled allergens and ingested allergens in different genders,seasons and ages.RESULTS 1.Among the 2 329 AR patients,the positive rate of sIgE was 55.00%,including 53.20%for inhalation allergens and 10.91%for ingestion allergens;2.The allergens of AR patients in Ningbo were mainly inhaled allergens,and the top 5 were house dust mites(90.16%),dust mites(86.61%),tropical parachus(17.66%),the top 5 allergens of cat hair(9.92%)and dog hair(7.82%)were milk(57.87%),shrimp(30.71%),crab(19.29%),egg white(17.32%)and peanut(9.84%);3.There was a statistically significant difference in the positive rates of sIgE between house dust mites in inhaled allergens and milk,crab and shrimp in ingested allergens among different gender groups(P<0.05);4.There was no significant difference in the positive rate of each allergen among patients of different ages and disease seasons(P>0.05),but 56.44%of AR patients were concentrated in minors,and the positive rate of house dust mites was statistically significant among minors(P<0.05).CONCLUSION The main allergens causing AR in Ningbo are house dust mites and dust mites,and the prevention and control work should be actively carried out,precise allergen-specific immunotherapy should be promoted,and the treatment of juvenile AR patients should be emphasized.

Objective To establish a coronavirus(CoV)infection model using human nasal mucosa organoids for testing antiviral drugs and evaluate the feasibility of using human nasal mucosa organoids with viral infection as platforms for viral research and antiviral drug development.Methods Human nasal mucosa organoids were tested for susceptibility to SARS-CoV-2 and HCoV-OC43 pseudoviruses.In a P3 laboratory,nasal mucosa organoids were infected with the original strain of SARS-CoV-2 and 4 variant strains,and the infection conditions were optimized.The viral loads in the culture supernatants were measured at different time points using RT-qPCR,and immunofluorescence assay was employed to localize SARS-CoV-2 nucleocapsid protein to determine the type of the infected cells.In the optimized nasal mucosa viral infection model,the antiviral effects of camostat and bergamot extract(which were known to inhibit SARS-CoV-2)were tested and the underlying molecular mechanisms were explored.Results In the optimized nasal mucosa organoid models infected with SARS-CoV-2 and HCoV-OC43 pseudoviruses,the viral load in the culture supernatants increased significantly during the period of 2 to 24 h following the infection,which confirmed infection of the organoids by both of the pseudoviruses.The nasal mucosa organoids could be stably infected by the original SARS-CoV-2 strain and its 4 variant strains,validating successful establishment of the viral infection model,in which both camostat and bergamot extract exhibited dose-dependent antiviral effects.Conclusions Human nasal mucosa organoids with SARS-CoV-2 infection can serve as platforms for screening and testing antiviral drugs,particularly those intended for nasal administration.