Objective:To explore the differences in the ability of different parts of the human skin to recognize vibration frequencies in order to provide data for physiological optimization of vibration parameters in pilots′ tactile vests.Methods:Ten healthy volunteers were selected and grouped by age as 20-40 years (6 cases) and 41-50 years (4 cases). All the subjects participated in 3 trials: ① identification test of frequency steps using cutaneous tactile perception: the back of the left hand was chosen as the test area, a dual-oscillator synchronous vibration system was adopted, and the frequency step was gradually increased (initially 0.1 Hz) to determine the threshold of frequency identification; ② maximum frequency threshold test of cutaneous tactile perception: the maximum frequency recognition thresholds in 7 parts of the trunk (the left waist, right waist, chest, back, left shoulder, right shoulder, neck) and the back of the hand were tested; ③ frequency discrimination test of cutaneous tactile perception: 5 equally spaced frequencies (covering the frequency recognition thresholds) were set to evaluate the accuracy of tactile frequency memory on the back of the hand after 3, 15 min and 24 h. The relationships between the adjacent step sizes of cutaneous tactile perception and the average value of the sum of adjacent frequencies were analyzed using simple linear regression. The highest identification thresholds of frequencies in different parts of the subjects as well as the accuracy of frequency discrimination during different periods were compared across the age groups.Results:The maximum thresholds of frequency identification of cutaneous tactile perception among the 10 subjects ranged from 16.20 to 33.55 Hz, while the range of adjacent step sizes was between 3.60 and 7.10 Hz. The adjacent step sizes were positively correlated with the average value of the sum of adjacent frequencies ( r=0.882, F=529.18, P<0.001). In the test on the maximum threshold of frequency identification of cutaneous tactile perception, there was a statistically significant difference in the main effect of an age group between the 2 groups ( F=15.87, P<0.001), but not in the main effect of the site ( P>0.05), or in the interactions between the group and age ( P>0.05). The accuracies of skin vibration frequency memory on the dorsal hand of the subjects at 3, 15 min and 24 h were 88%, 72% and 68% respectively. In the frequency discrimination test, there were no statistically significant differences in the main effect of the group, main effect of time or in their interactions between the 2 groups (all P>0.05). Conclusions:The ability of the human skin to identify vibration frequency is impacted by age, but there is no difference in sensitivity between the trunk and the back of the hand. It is recommended that the tactile vest for pilots be designed for general purposes to make it easy to adapt to vibration frequencies of multiple parts.

Objective:To explore the differences in the ability of different parts of the human skin to recognize vibration frequencies in order to provide data for physiological optimization of vibration parameters in pilots′ tactile vests.Methods:Ten healthy volunteers were selected and grouped by age as 20-40 years (6 cases) and 41-50 years (4 cases). All the subjects participated in 3 trials: ① identification test of frequency steps using cutaneous tactile perception: the back of the left hand was chosen as the test area, a dual-oscillator synchronous vibration system was adopted, and the frequency step was gradually increased (initially 0.1 Hz) to determine the threshold of frequency identification; ② maximum frequency threshold test of cutaneous tactile perception: the maximum frequency recognition thresholds in 7 parts of the trunk (the left waist, right waist, chest, back, left shoulder, right shoulder, neck) and the back of the hand were tested; ③ frequency discrimination test of cutaneous tactile perception: 5 equally spaced frequencies (covering the frequency recognition thresholds) were set to evaluate the accuracy of tactile frequency memory on the back of the hand after 3, 15 min and 24 h. The relationships between the adjacent step sizes of cutaneous tactile perception and the average value of the sum of adjacent frequencies were analyzed using simple linear regression. The highest identification thresholds of frequencies in different parts of the subjects as well as the accuracy of frequency discrimination during different periods were compared across the age groups.Results:The maximum thresholds of frequency identification of cutaneous tactile perception among the 10 subjects ranged from 16.20 to 33.55 Hz, while the range of adjacent step sizes was between 3.60 and 7.10 Hz. The adjacent step sizes were positively correlated with the average value of the sum of adjacent frequencies ( r=0.882, F=529.18, P<0.001). In the test on the maximum threshold of frequency identification of cutaneous tactile perception, there was a statistically significant difference in the main effect of an age group between the 2 groups ( F=15.87, P<0.001), but not in the main effect of the site ( P>0.05), or in the interactions between the group and age ( P>0.05). The accuracies of skin vibration frequency memory on the dorsal hand of the subjects at 3, 15 min and 24 h were 88%, 72% and 68% respectively. In the frequency discrimination test, there were no statistically significant differences in the main effect of the group, main effect of time or in their interactions between the 2 groups (all P>0.05). Conclusions:The ability of the human skin to identify vibration frequency is impacted by age, but there is no difference in sensitivity between the trunk and the back of the hand. It is recommended that the tactile vest for pilots be designed for general purposes to make it easy to adapt to vibration frequencies of multiple parts.

Objective:To propose a preliminary method for real-time assessment of pilot situational awareness based on assessing pilot′s visual gaze behavior during spatial orientation flight simulation.Methods:Fighter pilots who met the criteria were randomly selected by drawing lots. An eye-tracker was used to collect eye-track feature data from pilots in a flight simulator. The lightweight YOLOv8n model was used to detect the area of interest (AOI) in the training to construct the AOI gaze sequence feature data. The pilot′s illusory experiences and recovery from complex situations were recorded, and those were scored by the situation awareness global assessment technique to obtain such 3 situational awareness assessment levels as excellent, good, and fair which were used as labeled data. A transformer and inception module fusion situation awareness (Ti-SA) model was developed to extract and learn the features of eye-tracking time-series data and AOI gaze time-series data and was compared with other commonly used models in the field of multidimensional time-series classification.Results:Thirty fighter pilots were enrolled, all male, aged 23-38 years old, with flying hours of 300-2 200 h, were included in the study. Nineteen temporal features of pilots′ eye movement trajectories were obtained by eye-tracker. By situation awareness global assessment, 12 pilots were scored to excellent level, 15 to good level and 3 to fair level. When Ti-SA model was applied to the experimental dataset, the accuracy was 92.18%, the precision was 92.95%, the recall was 95.49%, and the F1 score was 94.20%, which were better than other commonly used models in the field of multidimensional time-series classification.Conclusions:The study indicates that the proposed dataset construction method and Ti-SA model can effectively assess the level of pilot situational awareness in spatial orientation flight simulation.

Objective:To propose a preliminary method for real-time assessment of pilot situational awareness based on assessing pilot′s visual gaze behavior during spatial orientation flight simulation.Methods:Fighter pilots who met the criteria were randomly selected by drawing lots. An eye-tracker was used to collect eye-track feature data from pilots in a flight simulator. The lightweight YOLOv8n model was used to detect the area of interest (AOI) in the training to construct the AOI gaze sequence feature data. The pilot′s illusory experiences and recovery from complex situations were recorded, and those were scored by the situation awareness global assessment technique to obtain such 3 situational awareness assessment levels as excellent, good, and fair which were used as labeled data. A transformer and inception module fusion situation awareness (Ti-SA) model was developed to extract and learn the features of eye-tracking time-series data and AOI gaze time-series data and was compared with other commonly used models in the field of multidimensional time-series classification.Results:Thirty fighter pilots were enrolled, all male, aged 23-38 years old, with flying hours of 300-2 200 h, were included in the study. Nineteen temporal features of pilots′ eye movement trajectories were obtained by eye-tracker. By situation awareness global assessment, 12 pilots were scored to excellent level, 15 to good level and 3 to fair level. When Ti-SA model was applied to the experimental dataset, the accuracy was 92.18%, the precision was 92.95%, the recall was 95.49%, and the F1 score was 94.20%, which were better than other commonly used models in the field of multidimensional time-series classification.Conclusions:The study indicates that the proposed dataset construction method and Ti-SA model can effectively assess the level of pilot situational awareness in spatial orientation flight simulation.

OBJECTIVES: The automatic delineation of organs at risk (OARs) can help doctors make radiotherapy plans efficiently and accurately, and effectively improve the accuracy of radiotherapy and the therapeutic effect. Therefore, this study aims to propose an automatic delineation method for OARs in cervical cancer scenarios of both after-loading and external irradiation. At the same time, the similarity of OARs structure between different scenes is used to improve the segmentation accuracy of OARs in difficult segmentations. METHODS: Our ensemble model adopted the strategy of ensemble learning. The model obtained from the pre-training based on the after-loading and external irradiation was introduced into the integrated model as a feature extraction module. The data in different scenes were trained alternately, and the personalized features of the OARs within the model and the common features of the OARs between scenes were introduced. Computer tomography (CT) images for 84 cases of after-loading and 46 cases of external irradiation were collected as the train data set. Five-fold cross-validation was adopted to split training sets and test sets. The five-fold average dice similarity coefficient (DSC) served as the figure-of-merit in evaluating the segmentation model. RESULTS: The DSCs of the OARs (the rectum and bladder in the after-loading images and the bladder in the external irradiation images) were higher than 0.7. Compared with using an independent residual U-net (convolutional networks for biomedical image segmentation) model [residual U-net (Res-Unet)] delineate OARs, the proposed model can effectively improve the segmentation performance of difficult OARs (the sigmoid in the after-loading CT images and the rectum in the external irradiation images), and the DSCs were increased by more than 3%. CONCLUSIONS Comparing to the dedicated models, our ensemble model achieves the comparable result in segmentation of OARs for different treatment options in cervical cancer radiotherapy, which may be shorten time for doctors to sketch OARs and improve doctor's work efficiency.
Female ; Humans ; Image Processing, Computer-Assisted/methods* ; Machine Learning ; Organs at Risk/radiation effects* ; Radiotherapy Planning, Computer-Assisted/methods* ; Uterine Cervical Neoplasms/radiotherapy*

Objective To determine the risk factors associated with early allograft dysfunction (EAD) after liver transplantation. Methods We retrospectively analyzed the records of 138 patients who underwent liver transplantation from January 2006 to October 2016 in our department. Transplant recipients were divided into two groups:those who met the diagnostic criteria of EAD (EAD group) and those who did not (non-EAD group). We compared blood flow into the transplanted livers and other clinical features between the two groups using univariate and multivariate analysis. Results Intraoperative portal vein flow (PVF) maximum was significantly different between the two groups. Multivariate analysis revealed that intraoperative PVF maximum ＜1 600 mL/min was the only independent risk factor for the occurrence of EAD after liver transplantation in this cohort. Conclusion Intraoperative PVF maximum ＜1 600 mL/min is an independent risk factor for the occurrence of EAD after liver transplantation. Measuring intraoperative blood flow into the transplanted liver in liver transplant recipients may help identify patients at risk for developing EAD.

Objective To investigate the effect of donepezil on subventricular zone ( SVZ) neuro-genesis related neurotrophic factors after cerebral infarction. Methods Mice were randomly assigned into three groups: vehicle-treated sham group (Sham+vehicle,n=18),vehicle-treated middle cerebral artery oc-clusion (MCAO) group (MCAO + vehicle,n=30) and donepezil-treated MCAO group (MCAO+donepezil, n=30). Middle cerebral artery occlusion( MCAO) was induced by thread-occlusion method. Nissl staining was used to measure the infarct volume and the modified neurological severity score(mNSS) was used to as-sess neurologic function and brain water content was detected to assess brain edema degree. Proliferative cells and neuroblasts were labeled with 5-bromodeoxyuridine ( BrdU) and doublecortin ( DCX). The SVZ BrdU+/DCX+cells were detected by immunofluorescence. The expression of glial cell line-derived neurotro-phic factor (GDNF),brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were detec-ted by Western blot. Results The infarct volume of MCAO + donepezil group ((13. 33±4. 55)%) was sig-nificantly lower than that of MCAO + vehicle group ((31. 33±3. 93)%,t=7. 34,P<0. 05). The neurologic deficits were significantly ameliorated after donepezil treatment,and the brain water content of MCAO + done-pezil group ((71. 82±10. 18)%)was significantly less than that of MCAO + vehicle group ((85. 93± 7. 54)%,F=13. 480,P<0. 05). All differences were statistically significant (P<0. 05). The area of BrdU+/DCX+cells within SVZ of MCAO + vehicle group ((6. 16±1. 79)%) was significantly larger than that of sham + vehicle group ((2. 25±1. 09)%),and was fewer than that of MCAO+donepezil group ((16. 19± 2. 16)%,F=102. 756,P<0. 05). MCAO significantly promoted the expression of GDNF,BDNF and NGF within SVZ compared with sham operation,and donepezil increased these protein levels(F=15. 114,27. 121, 27. 398,P<0. 05). Conclusion Donepezil regulates neurogenesis via increasesing the expression of GDNF, BDNF and NGF within SVZ after cerebral infarction.

Objective To investigate the effects of cholinergic signal on neural stem cell(NSC)differenti-ation in peri-infarction region after ischemic stroke. Methods Mice were randomly assigned into sham + vehicle group,middle cerebral artery occlusion(MCAO)+ vehicle group,MCAO + donepezil group and MCAO + atro-pine group(n = 25). MCAO was induced by thread-occlusion method. Modified neurological severity score (mNSS)was used to evaluate neurological function recovery,and the brain water content was measured by dry-wet weight method. NeuN/5-bromodeoxyuridine(BrdU),CNPase/BrdU,GFAP/BrdU double-labeled cells were tested by immunofluorescence. Results Brain water content of MCAO + vehicle group was significantly higher than that of sham operation group(P < 0.05). Donepezil-treated MCAO mice had lower neurologic deficit scores and brain water content than of MCAO + vehicle group(P < 0.05). On day 14 and day 28 after MCAO,the NeuN/BrdU, CNPase/BrdU and GFAP/BrdU immune-positive cells of MCAO + vehicle group were markedly increased as com-pared with that of sham+vehicle group(P<0.05).Compared with that of MCAO+vehicle group,the number of NeuN/BrdU-positive cells,CNPase/BrdU-positive cells and GFAP/BrdU-positive cells was higher in MCAO+done-pezil group,and the number of NeuN/BrdU-positive cells and CNPase/BrdU-positive cells of MCAO + atropine group was lower(P < 0.05). Conclusions Cholinergic signal could promote NSCs differentiation in peri-infarc-tion region,a lleviate cerebral edema,and improve the brain function restoration after stroke.

Objective To investigate the role of Src signaling pathway in neurogenesis promoted by choline acetyltransferase (CHAT) + neurons in the subventricular zone (SVZ) after ischemic stroke.Methods The eighty-four mice were randomly assigned into four groups:sham-operated mice treated with vehicle (Sham+vehicle,n=18),middle cerebral artery occlusion (MCAO)-operated mice treated with vehicle (MCAO+vehicle,n=22),MCAO mice treated with donepezil (MCAO+donepezil,n=21),MCAO mice treated with donepezil and Src inhibitor KX2-391 (MCAO+donepezil+KX2-391,n=23).Mice were subjected to the temporary MCAO model of ischemic stroke.Modified neurological severity score (mNSS) was used to assess neurologic function of the mice.Proliferative cells were labeled with Ki67,and neuroblasts with doublecortin (DCX).The expression of Ki67+/DCX+ in the SVZ was detected by immunofluorescence.The expression of Ki67,phospho-epidermal growth factor receptor (p-EGFR),p-Raf,Src and p-Akt in the SVZ were quantified by Western blot.Results MCAO+donepezil+KX2-391 group showed worse performance in the mNSS test than MCAO+donepezil group (P＜0.05).Ten days after MCAO,the number of Ki67+/DCX+ cells in the SVZ of MCAO+donepezil group was 125.33± 13.71/area,which was 71.67± 18.35/area in MCAO+ donepezil+KX2-391 group (P＜0.05).What's more,the expression of proteins Ki67,p-EGFR,p-Raf,Src and p-Akt in mice of MCAO+donepezil group was markedly increased,which was (1.39±0.23),(1.42±0.19),(0.88±0.13),(1.14±0.19),(1.04±0.18) and it was decreased in MCAO+donepezil+KX2-391 group,which was 0.84±0.26,0.94±0.26,0.73±0.15,0.71±0.18,0.81±0.19(P＜0.05).Conclusion CHAT+ neurons in SVZ may promote neurogenesis after stroke via Src-epidermal growth factor receptor (EGFR) signaling pathway.

Objective To observe the activities of ChAT + neurons in subventricular zone (SVZ) after ischemic stroke and their effects on angiogenesis in peri-infarction region and related signaling pathways. Methods C57BL/6 mice were randomly assigned into sham group,middle cerebral artery occlusion (MCAO) group and atropine group. Ischemic models were made by permanent coagulation of the distal middle cerebral artery. The expression of ChAT,AChE in SVZ and VEGF,VEGFR2,pERK in peripheral regions of ischemic injury was evaluated by Western blotting and immunofluorescence. 5-bromodeoxyuridine(BrdU)/CD31 double-labeled cells were also tested by immunofluorescence. Results At 14 d after the surgery,the ratio of ChAT/AChE in SVZ increased after stroke(P < 0.05). Compared with those in Sham group,the levels of VEGF,VEGFR2 and pERK were higher in MCAO group(P<0.05)and VEGFR2-positive and BrdU/CD31-positive cells increased significantly. However,lower expression of VEGF,VEGFR2 and pERK and less VEGFR2-positive and BrdU/CD31-positive cells were found in atropine group when compared with that in MCAO group. Conclusions The activities of ChAT +neurons in SVZ are enhanced after ischemic injury and they can promote angiogenesis in peripheral region of ischemic injury via upregulating VEGF-VEGFR2 signaling pathway and improving the brain function restoration.