BACKGROUND: Neoadjuvant chemoradiotherapy followed by radical surgery has been a common practice for patients with locally advanced rectal cancer, but the response rate varies among patients. This study aimed to develop a ResNet-Vision Transformer based magnetic resonance imaging (MRI)-endoscopy fusion model to precisely predict treatment response and provide personalized treatment. METHODS: In this multicenter study, 366 eligible patients who had undergone neoadjuvant chemoradiotherapy followed by radical surgery at eight Chinese tertiary hospitals between January 2017 and June 2024 were recruited, with 2928 pretreatment colonic endoscopic images and 366 pelvic MRI images. An MRI-endoscopy fusion model was constructed based on the ResNet backbone and Transformer network using pretreatment MRI and endoscopic images. Treatment response was defined as good response or non-good response based on the tumor regression grade. The Delong test and the Hanley-McNeil test were utilized to compare prediction performance among different models and different subgroups, respectively. The predictive performance of the MRI-endoscopy fusion model was comprehensively validated in the test sets and was further compared to that of the single-modal MRI model and single-modal endoscopy model. RESULTS: The MRI-endoscopy fusion model demonstrated favorable prediction performance. In the internal validation set, the area under the curve (AUC) and accuracy were 0.852 (95% confidence interval [CI]: 0.744-0.940) and 0.737 (95% CI: 0.712-0.844), respectively. Moreover, the AUC and accuracy reached 0.769 (95% CI: 0.678-0.861) and 0.729 (95% CI: 0.628-0.821), respectively, in the external test set. In addition, the MRI-endoscopy fusion model outperformed the single-modal MRI model (AUC: 0.692 [95% CI: 0.609-0.783], accuracy: 0.659 [95% CI: 0.565-0.775]) and the single-modal endoscopy model (AUC: 0.720 [95% CI: 0.617-0.823], accuracy: 0.713 [95% CI: 0.612-0.809]) in the external test set. CONCLUSION The MRI-endoscopy fusion model based on ResNet-Vision Transformer achieved favorable performance in predicting treatment response to neoadjuvant chemoradiotherapy and holds tremendous potential for enabling personalized treatment regimens for locally advanced rectal cancer patients.
Humans ; Rectal Neoplasms/diagnostic imaging* ; Magnetic Resonance Imaging/methods* ; Male ; Female ; Middle Aged ; Neoadjuvant Therapy/methods* ; Aged ; Adult ; Chemoradiotherapy/methods* ; Endoscopy/methods* ; Treatment Outcome

Objective To explore the failure criterion that can accurately simulate the tensile and compressive fracture of hollow cortical bone structure.Methods Based on the previous compression and bending experimental data,the predicted results using different failure criteria were compared to determine the simulation accuracy.Results Under the compressive load,the differences in the fracture load between the simulations using the equivalent and invariant strain failure criteria and the experiment were less than 5％,indicating that these two failure criteria were suitable for predicting the cortical bone failure;under the bending load,the differences in the fracture load between the simulations using the equivalent and invariant strain failure criteria and the experiment were less than 5％,indicating that these two failure criteria could accurately predict the failure process.Conclusions The prediction accuracy using different failure criteria mainly depends on whether the strain growth rate conforms to the actual bone deformation.Too fast or too low strain growth rate will lead to premature or delayed structural fracture.The fracture simulation adopted in this study is suitable for most cortical bone structures,and can be used to determine the suitable failure criterion under different loads,so as to assist in obtaining the strength limit of cortical bone in various parts and provide data support for improving the simulation accuracy and grasping the condition of fracture occurrence in clinical practice.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes were found to be effective in promoting neural repair in spinal cord injury.OBJECTIVE:To investigate whether exosomes derived from human umbilical cord mesenchymal stem cells are able to attenuate neuroinflammation and promote recovery of motor function by promoting polarization of microglia toward the M2 type.METHODS:Totally 48 SD rats were randomly divided into a sham operation group,a model group,and an exosome group(n=16 per group).A rat spinal cord injury model was established using the modified Allen method.The exosome group was injected with 20 μL of human umbilical cord mesenchymal stem cell-derived exosomes intrathecally via neuroendoscopy 24 hours after injury.At 3,7,14,and 21 days after modeling,the recovery of the motor function of the hind limbs of the rats was assessed by BBB scoring method combined with Rivlin's slant plate test.The damage of spinal cord tissues was detected by using hematoxylin-eosin staining and Nissl staining.The expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor A proteins were detected by western blot assay.The expression proportion of M1-type markers(inducible nitric oxide synthase)and M2 markers(arginase-1)in the spinal cord tissues was detected by immunofluorescence method.qRT-PCR and western blot assay were used to detect the expression levels of inducible nitric oxide synthase and arginase-1 in spinal cord tissues.ELISA was utilized to detect the levels of pro-inflammatory factors(tumor necrosis factor α,interleukin 1β,and interleukin 6)and anti-inflammatory factors(interleukin 10)levels in spinal cord tissues.RESULTS AND CONCLUSION:(1)At 3,7,and 14 days postoperatively,the BBB scores of the exosome group were better than those of the model group(P＜0.05).The angles of the Rivlin slanting plate experiments of the exosome group were significantly higher than those of the model group at 7 and 14 days postoperatively(P＜0.05).The results of hematoxylin-eosin staining and Nissl staining indicated that the spinal cord tissues and nerve injuries of the exosome group were reduced in comparison with those of the model group,and the levels of brain-derived neurotrophic factor and vascular endothelial growth factor A in spinal cord tissues of the exosome group were higher than those in the model group at 7 days postoperatively(P＜0.05).(2)Immunofluorescence experiments showed that the number of inducible nitric oxide synthase-positive microglial cells in the lesion area of the exosome group was significantly reduced and the level of Arg1-positive microglial cells increased in the lesion area of the exosome group compared with the model group at 7 days postoperatively(P＜0.05).qRT-PCR and western blot assay also confirmed the results of immunofluorescence experiments.(3)The secretion of pro-inflammatory factors tumor necrosis factor α,interleukin 1β,and interleukin 6 in spinal cord tissues of the exosome group was reduced compared with the model group(P＜0.05),whereas the secretion of the inflammation-suppressing factor interleukin 10 was increased compared with the model group(P＜0.05).These findings conclude that human umbilical cord mesenchymal stem cell-derived exosomes could promote the polarization of microglial cells from the M1 to the M2 type and decrease the release of pro-inflammatory factors,thereby reducing the secondary damage of neuroinflammation in spinal cord injury.

BACKGROUND:Human umbilical cord mesenchymal stem cell-derived exosomes were found to be effective in promoting neural repair in spinal cord injury.OBJECTIVE:To investigate whether exosomes derived from human umbilical cord mesenchymal stem cells are able to attenuate neuroinflammation and promote recovery of motor function by promoting polarization of microglia toward the M2 type.METHODS:Totally 48 SD rats were randomly divided into a sham operation group,a model group,and an exosome group(n=16 per group).A rat spinal cord injury model was established using the modified Allen method.The exosome group was injected with 20 μL of human umbilical cord mesenchymal stem cell-derived exosomes intrathecally via neuroendoscopy 24 hours after injury.At 3,7,14,and 21 days after modeling,the recovery of the motor function of the hind limbs of the rats was assessed by BBB scoring method combined with Rivlin's slant plate test.The damage of spinal cord tissues was detected by using hematoxylin-eosin staining and Nissl staining.The expression levels of brain-derived neurotrophic factor and vascular endothelial growth factor A proteins were detected by western blot assay.The expression proportion of M1-type markers(inducible nitric oxide synthase)and M2 markers(arginase-1)in the spinal cord tissues was detected by immunofluorescence method.qRT-PCR and western blot assay were used to detect the expression levels of inducible nitric oxide synthase and arginase-1 in spinal cord tissues.ELISA was utilized to detect the levels of pro-inflammatory factors(tumor necrosis factor α,interleukin 1β,and interleukin 6)and anti-inflammatory factors(interleukin 10)levels in spinal cord tissues.RESULTS AND CONCLUSION:(1)At 3,7,and 14 days postoperatively,the BBB scores of the exosome group were better than those of the model group(P＜0.05).The angles of the Rivlin slanting plate experiments of the exosome group were significantly higher than those of the model group at 7 and 14 days postoperatively(P＜0.05).The results of hematoxylin-eosin staining and Nissl staining indicated that the spinal cord tissues and nerve injuries of the exosome group were reduced in comparison with those of the model group,and the levels of brain-derived neurotrophic factor and vascular endothelial growth factor A in spinal cord tissues of the exosome group were higher than those in the model group at 7 days postoperatively(P＜0.05).(2)Immunofluorescence experiments showed that the number of inducible nitric oxide synthase-positive microglial cells in the lesion area of the exosome group was significantly reduced and the level of Arg1-positive microglial cells increased in the lesion area of the exosome group compared with the model group at 7 days postoperatively(P＜0.05).qRT-PCR and western blot assay also confirmed the results of immunofluorescence experiments.(3)The secretion of pro-inflammatory factors tumor necrosis factor α,interleukin 1β,and interleukin 6 in spinal cord tissues of the exosome group was reduced compared with the model group(P＜0.05),whereas the secretion of the inflammation-suppressing factor interleukin 10 was increased compared with the model group(P＜0.05).These findings conclude that human umbilical cord mesenchymal stem cell-derived exosomes could promote the polarization of microglial cells from the M1 to the M2 type and decrease the release of pro-inflammatory factors,thereby reducing the secondary damage of neuroinflammation in spinal cord injury.

Objective To explore the failure criterion that can accurately simulate the tensile and compressive fracture of hollow cortical bone structure.Methods Based on the previous compression and bending experimental data,the predicted results using different failure criteria were compared to determine the simulation accuracy.Results Under the compressive load,the differences in the fracture load between the simulations using the equivalent and invariant strain failure criteria and the experiment were less than 5％,indicating that these two failure criteria were suitable for predicting the cortical bone failure;under the bending load,the differences in the fracture load between the simulations using the equivalent and invariant strain failure criteria and the experiment were less than 5％,indicating that these two failure criteria could accurately predict the failure process.Conclusions The prediction accuracy using different failure criteria mainly depends on whether the strain growth rate conforms to the actual bone deformation.Too fast or too low strain growth rate will lead to premature or delayed structural fracture.The fracture simulation adopted in this study is suitable for most cortical bone structures,and can be used to determine the suitable failure criterion under different loads,so as to assist in obtaining the strength limit of cortical bone in various parts and provide data support for improving the simulation accuracy and grasping the condition of fracture occurrence in clinical practice.

The visual impairment and blindness caused by myopia have become a global burden, and the World Health Organization has included the prevention and control of myopia in the global program for preventing blindness. In China, the development of myopia is showing a trend with higher incidence, younger age, and higher refractive errors. Moving forward the port of prevention and control myopia has become an important strategy to address the current predicament. Premyopia refers to the stage in children where the refractive power is ≤+0.75 D and >-0.50 D, and there are multiple risk factors during this stage that can potentially lead to myopia. Currently, the incidence of premyopia and its transformation into myopia is high, and the key prevention and control measures include building a predictive model for the transformation of premyopia into myopia, emphasizing the reduction of exposure to risk factors, using low-concentration atropine eye drops, red light therapy, and optical defocus intervention. This article provides a comprehensive review of the current situation regarding the incidence of premyopia and its transformation into myopia, as well as the research progress on existing prevention and control measures, with the aim of providing relevant references for the prevention and control of myopia during the premyopia stage.

Objective To predict the micro-level energy release rate in the rat femoral cortical bone and investigate the variation in the micro-level energy release rate with age.Methods Based on previous experimental data and numerical simulation of fracture modes for cortical bone,load-displacement curves and fracture modes measured by simulation and experiment were compared,and the micro-level energy release rates of rat femoral cortical bone at different months were predicted by back-calculation.Results It was predicted that the micro-level energy release rate of rat femoral cortical bone at 1-,3-,5-,7-,9-,11-,and 15-month age was 0.08-0.12,0.12-0.14,0.15-0.19,0.25-0.28,0.23-0.25,0.19-0.22,and 0.13-0.16 N/mm,respectively.Conclusions The decrease in the microlevel energy release rate with increasing age led to a decreasing failure load,indicating that the microlevel energy release rate is one of the main factors determining fracture occurrence;however,no significant decrease was observed at the time of fracture,indicating that the microlevel energy release rate was not linearly proportional to the fracture time.These results can help explain the mechanism of cortical bone fractures at the clinical level.

Objective To study the injury risk and fatigue status of firefighters with different training postures under load-bearing conditions to reduce the occurrence of physical injuries and occupational diseases.Methods First,a questionnaire was administered to investigate the training injury conditions of firefighters in a fire-rescue brigade.Considering the exercise fatigue factor,which accounts for the highest proportion of injury causes,lower back analysis,static strength analysis,fatigue analysis,comfort analysis,and other human factor analysis tools in Jack software were used to analyze four common firefighter water-shooting training postures.Training postures while climbing a five-storey building with loads and a hooked ladder were also simulated.Results Injury caused by exercise fatigue accounted for 69.8%of injuries and was the most important injury-causing factor.The risk of knee and ankle joint injuries increased in all four water-shooting postures.The comfort levels of the four water-shooting postures from high to low were shoulder,standing,kneeling,and lying postures.For the entire dynamic training process,while climbing the five-storey building with loads and climbing the hooked ladder,firefighters did not have an increased risk of lower back injury but had an increased risk of ankle and knee joint injuries.Conclusions Some training postures are uncomfortable for firefighters,and they experience body discomfort during firefighting training with loads,thereby increasing injury risk.These results provide scientific references for the prevention and reduction of firefighter training injuries,and the formulation of reasonable training plans and targeted protective measures.

Objective:To explore the benefits of transradial diagnostic cerebral angiography in elderly patients and its correlation with morphometric parameters of the aortic arch.Methods:Clinical data and aortic arch CTA imaging parameters of patients who underwent cerebral angiography at the Department of Neurosurgery, Beijing Hospital, between May 2022 and April 2023 were retrospectively analyzed.The study aimed to compare the time taken for angiography via radial artery access in elderly patients versus younger patients, as well as via femoral artery access, and to evaluate the associated aortic arch morphology parameters.Results:A total of 101 patients' data were analyzed, with 67 males(66.3%)and an average age of 63.4±12.0 years.Among them, 69 patients(68.3%)were aged 60 and above.The arterial approach for 44 patients(43.6%)was radial, while 57 cases(56.4%)used the femoral artery approach.In the elderly group, 14 cases(20.6%), 31 cases(45.6%), and 23 cases(33.8%)had type Ⅲ aortic arch, respectively.For younger patients, 17 cases(53.1%), 12 cases(37.5%), and 3 cases(9.4%)fell into these categories.The distribution difference was statistically significant( χ2=12.765, P=0.002).Elderly patients had a larger aortic arch width angle compared to younger patients(106°±12°and 100°±12°, t=2.334, P=0.022).The time for whole-brain angiography via radial artery was shorter for elderly patients than via femoral artery(39.8±29.5 minutes and 52.2±28.4 minutes, respectively, t=1.845, P=0.070).In young patients, there was no significant time difference between the two approaches(42.3±30.4 minutes for radial artery and 34.6±11.2 minutes for femoral artery, t=1.026, P=0.313).In the type Ⅱ aortic arch group, the average times for transradial and transfemoral approaches were 38.1±21.7 minutes and 46.7±32.2 minutes, respectively( t=1.020, P=0.314).The average times for the type Ⅲ aortic arch group were 41.9±37.3 minutes and 48.9±20.7 minutes, respectively.Correlation analysis revealed a significant negative correlation between the duration of radial artery access and the distance from the origin of the innominate artery to the left subclavian artery(Pearson correlation coefficien( r=-0.372, P=0.014). Conclusions:In elderly patients, particularly those with type Ⅱ or Ⅲ aortic arch or a wide aortic arch, diagnostic cerebral angiography using transradial access is preferable to femoral access.The distance between the innominate artery and the left subclavian artery origin could impact the duration of the procedure.

Using machine learning algorithms to construct an early prediction model of brucellosis to improve the diagnosis efficiency of Brucellosis. This study was a case-control study. 2 381 brucellosis patients from Beijing Ditan Hospital affiliated to Capital Medical University were retrospectively collected as case group, and healthy people from Beijing Chaoyang Hospital affiliated to Capital Medical University were collected as control group from May 9, 2011 to November 29, 2021. The relevant clinical information and full blood count results of 13 257 data were collected and five algorithms of machine learning were used to construct an early predication model of brucellosis by using machine learning: random forest, Naive Bayes, decision tree, logistic regression and support vector machine;14 074 data (2 143 cases incase group and 11 931 cases in control group) were used to establish the early predication model of brucellosis, and 1 564 (238 cases in case group and 1 326 cases in control group) data were used to test the predication efficiency of the brucellosis model. The results showed that the support vector machine algorithm has the best predication performance by comparing the five machine learning models. The area under receiver curve (AUC) of receiver operating characteristic (ROC) was 0.991, and the accuracy, precision, specificity and Recall were 95.6%, 95.5%, 95.4% and 95.9%, respectively. Based on the SHAP plot, platelet distribution width (PDW) and basophil relative value (BASO%) results were low, and men with high coefficient of variation (R-CV), erythrocyte hemoglobin concentration (MCHC), and platelet volume (MPV) were predicted to be at high risk of brucellosis. Platelet distribution width (PDW) contributed the most to the prediction model, followed by red blood cell distribution width coefficient of variation (R-CV). In conclusion, the establishment of a high-precision early predication method of brucellosis based on machine learning may be of great significance for the early detection and treatment of brucellosis patients.
Male ; Humans ; Retrospective Studies ; Case-Control Studies ; Bayes Theorem ; Algorithms ; Machine Learning