Objective To establish an analytical strategy covering multi-dataset processing, recursive feature elimination (RFE) screening and multi-model evaluation based on multiple machine learning algorithms, so as to screen radiation-sensitive genes and verify the feasibility of the evaluation strategy. Methods Qualified radiation transcriptome datasets were retrieved from public gene expression databases. Following standardized data preprocessing and feature preselection, 13 machine learning algorithms were adopted to construct models. The performance of each model was compared and validated in independent datasets. Results A total of 38 eligible datasets were included. Sixteen differentially expressed genes unreported in existing literature were screened out, among which ugcrhl, pdcl3, mct4, h2-g2 and fam120aos were correlated with radiation phenotypes. Ensemble learning algorithms including random forest and gradient boosting exhibited the optimal comprehensive performance. Independent dataset verification confirmed that the screened genes overlapped with known radiation-sensitive genes, and the model performance was consistent with the findings. Conclusion The machine learning strategy constructed in this study can effectively explore potential radiation-sensitive genes, and provides methodological support for subsequent relevant studies.

Objective To establish an analytical strategy covering multi-dataset processing, recursive feature elimination (RFE) screening and multi-model evaluation based on multiple machine learning algorithms, so as to screen radiation-sensitive genes and verify the feasibility of the evaluation strategy. Methods Qualified radiation transcriptome datasets were retrieved from public gene expression databases. Following standardized data preprocessing and feature preselection, 13 machine learning algorithms were adopted to construct models. The performance of each model was compared and validated in independent datasets. Results A total of 38 eligible datasets were included. Sixteen differentially expressed genes unreported in existing literature were screened out, among which ugcrhl, pdcl3, mct4, h2-g2 and fam120aos were correlated with radiation phenotypes. Ensemble learning algorithms including random forest and gradient boosting exhibited the optimal comprehensive performance. Independent dataset verification confirmed that the screened genes overlapped with known radiation-sensitive genes, and the model performance was consistent with the findings. Conclusion The machine learning strategy constructed in this study can effectively explore potential radiation-sensitive genes, and provides methodological support for subsequent relevant studies.

Objective To establish an analytical strategy covering multi-dataset processing, recursive feature elimination (RFE) screening and multi-model evaluation based on multiple machine learning algorithms, so as to screen radiation-sensitive genes and verify the feasibility of the evaluation strategy. Methods Qualified radiation transcriptome datasets were retrieved from public gene expression databases. Following standardized data preprocessing and feature preselection, 13 machine learning algorithms were adopted to construct models. The performance of each model was compared and validated in independent datasets. Results A total of 38 eligible datasets were included. Sixteen differentially expressed genes unreported in existing literature were screened out, among which ugcrhl, pdcl3, mct4, h2-g2 and fam120aos were correlated with radiation phenotypes. Ensemble learning algorithms including random forest and gradient boosting exhibited the optimal comprehensive performance. Independent dataset verification confirmed that the screened genes overlapped with known radiation-sensitive genes, and the model performance was consistent with the findings. Conclusion The machine learning strategy constructed in this study can effectively explore potential radiation-sensitive genes, and provides methodological support for subsequent relevant studies.

Objective:To design an improved lamina hook system and compare its biomechanical properties with traditional lamina hook system in fixation of lumbar spondylolysis.Methods:The thin layer CT data of the lumbosacral vertebrae of 20 healthy young male servicemen who underwent physical examination in the outpatient department of the 940th Hospital of Joint Logistics Support Force of PLA from January 2021 to August 2022 were collected. The age of the subjects was 20-30 years [(25.0±3.0)years]. A 3-dimensional model of the L 5 vertebral body was constructed using the 3-dimensional modeling software. The new improved lamina hook was designed according to the measurements including the thickness of the middle area, the longest longitudinal diameter, the curvature radius of the lower edge, the angle between the upper and lower tail ends, the thickness of the lower edge, and the longest diameter of the lower edge of the bilateral L 5 vertebral plates. One serviceman was selected from the aforementioned group to construct a linear finite element model of segments L 4-S using the 3-dimensional virtual software (normal model, model A), based on which, the L 5 bilateral spondylolysis model (model B), improved lamina hook model (model C) and traditional lamina hook models (model D) were designed. By constraining both sides of the sacrum and applying a longitudinal load of 400 N on the L 4 vertebral body, the upper 1/3 gravity of the body was simulated, and with a bending moment of 10 N·m along the X, Y, and Z directions, motions of forward flexion, backward extension, lateral bending, rotation, etc were simulated. The range of motion of segment L 4/5 and L 5/S 1 of model A was evaluated and compared with the findings of the previous researches to verify its effectiveness. The overall range of motion of models A, B, C, and D, the range of motion of segment L 4/5 and L 5/S 1, the maximum overall displacement, the maximum displacement and stress of the isthmus, the stress distribution and maximum stress of internal fixation of models C and D, and the stress distribution and maximum stress of the vertebral body of models C and D were compared. Results:(1) During forward flexion, backward extension, lateral bending and rotation, the range of motion of model A was 5.01°, 4.03°, 3.91° and 1.42° in segment L 4/5, and was 4.62°, 2.51°, 2.40° and 1.23° in segment L 5/S 1. (2) The overall range of motion, range of motion of segment L 4/5 and L 5/S 1 and maximum overall displacement of models A, C, and D were similar in axial compression, forward flexion, backward extension, left bending, and left rotation, while those of model B were significantly increased. (3) There was no significant difference in the maximum displacement of the isthmus of models A, C, and D under different motion modes, while the maximum displacement of model B in the isthmus was significantly larger than that of models A, C, and D, especially during rotation, increased by 295%, 277%, and 276% respectively. The maximum stress of the isthmus of model C was 0.938 MPa, 1.698 MPa, 0.410 MPa, 2.775 MPa, and 1.554 MPa respectively. The maximum stress in the isthmus of model D was 0.590 MPa, 1.297 MPa, 0.520 MPa, 3.088 MPa, and 2.072 MPa respectively. The maximum stress of the isthmus of models C and D was similar during axial compression and forward flexion, while the stress of the isthmus of model C was smaller than that of model D during backward extension, lateral bending, and rotation, decreased by 21.1%, 10.2%, and 25.0% respectively compared with model D. (4) The maximum stress of internal fixation in models C and D during forward flexion, backward extension, left bending, and left rotation was 135.220 MPa, 130.180 MPa, 200.940 MPa and 306.340 MPa respectively, and was 131.840 MPa, 112.280 MPa, 349.980 MPa and 370.140 MPa respectively. The maximum stress of internal fixation in the two models of internal fixation during forward flexion and backward extension was similar, while it was decreased by 42.6% and 17.2% in model C during left bending and left rotation, compared with model D. (5) The maximum stress of the vertebral body during forward flexion, backward extension, left bending, and left rotation was 79.787 MPa, 36.857 MPa, 37.943 MPa and 96.965 MPa respectively in model C, but was 80.104 MPa, 64.236 MPa, 196.010 MPa and 193.020 MPa respectively in model D. The maximum stress of models C and D was all distributed in the contact area with the internal fixation, and especially during backward extension, left bending, and left rotation, when it was reduced by 42.6%, 80.6%, and 49.8% of model C respectively, compared with that of model D. Conclusions:The improved laminar hook is more consistent with the Chinese anatomized structure of the lamina. Compared with the traditional lamina hook system, the improved lamina hook system can effectively reduce the displacement in all directions and range of motion of lumbar spondylolysis, therefor can significantly reduce the stress of internal fixation and vertebral body and has better biomechanical performance.

Objective:To explore classification models for radiosensitive lipid metabolites in human peripheral blood by combining lipidomics with multiple machine learning (ML) algorithms.Methods:Totally 97 peripheral blood samples were collected from 25 leukemia cases admitted to a general hospital in Beijing from March to September 2023 who were ready to undergo bone marrow transplantation, including 0 Gy blood samples before irradiation in the control group ( n=24), and 73 blood samples after irradiation at doses of 4, 8 and 12 Gy in the radiation group ( n=73), and the targeted lipidomic based on the ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) platform method to analyze the differences of different lipids between control and radiation groups. Then, lipids responsive to radiation doses of 0-12 Gy were identified using linear regression. Finally, classification models were constructed using five ML algorithms based on the training set, followed by the validation and evaluation of these models using the validation set. Results:Compared with the control group, the differences in the concentration changes of 62 lipids in 9 classes of lipid metabolites sensitive to radiation group were statistically significant ( t=-4.91 to 4.74, P<0.05), including sphingomyelins(SMs), cholesteryl esters(CEs), ceramides(Cers), phosphatidylinositols(PIs), hexosylceramides(HexCers), lysophosphatidylcholines (LysoPCs), phosphatidylcholines (PCOs), phosphatidylethanolamines (PEs), and lysophosphatidylethanolamines (LysoPEs). Twenty lipids responsive to radiation doses of 0-12 Gy were identified, namely 11 SMs, 7 CEs, 1 Cer, and 1 PI. The five models based on ML algorithms of decision tree (DT), support vector machine (SVM), light gradient boosting machine (Light GBM), random forest (RF), and K-nearest neighbors (KNN) all exhibited high goodness of fit (F1=0.69-1.00) and high sensitivity. The evaluation and validation metrics revealed that the RF-based model yielded the optimal radiation classification discrimination (sensitivity: 1.00; accuracy: 0.72; F1 score: 0.80). Conclusions:Lipid metabolites responsive to radiation and lipids responsive to radiation dose in human samples were identified using targeted lipidomics. The RF-based model can provide new ideas for exploring models of human radiosensitive lipid metabolites.

Objective:To investigate the effect of radiofrequency radiation (RF) from 5G mobile phone communication frequency bands (3.5 GHz and 4.9 GHz) on the permeability of the blood-brain barrier (BBB) in mice.Methods:A total of 24 healthy adult male C57BL/6 mice (6-8 weeks old) were randomly divided into Sham, 3.5 GHz RF and 4.9 GHz RF groups, and 8 mice in each group. Mice in the RF groups were systemically exposed to 5G cell phone radiation for consecutive 35 d(1 h/d) with 50 W/m 2 power density. The BBB permeability of mice was detected by Evans Blue (EB) fluorescence experiment. The expression levels of the BBB tight junction-related proteins (ZO-1, occludin and claudin-11) and the gap junction-related protein Connexin 43 were determined by Western blot. Results:The number of spots, fluorescence intensity and comprehensive score of EB were significantly increased in 3.5 GHz RF group and 4.9 GHz RF group compared with the Sham group ( t=12.98, 17.82, P<0.001). Compared with the Sham group, the content of S100B in mouse serum was significantly increased in 3.5 GHz RF group and 4.9 GHz RF group ( t=19.34, 14.68, P<0.001). The BBB permeability was increased in the RF group. The expression level of occludin protein was significantly reduced in the 3.5 GHz RF group ( t=-3.13, P<0.05), and this decrease was much profound in the 4.9 GHz RF group ( t=-6.55, P<0.01). But the protein levels of ZO-1, Claudin-11 and Connexin 43 in the cerebral cortex of the RF groups had no significantly difference in comparison with the Sham group( P>0.05). Conclusions:The continuous exposure of mobile phone RF at 3.5 GHz or 4.9 GHz for 35 d (1 h/d) induces an increase of BBB permeability in the mouse cerebral cortex, perhaps by reducing the expression of occludin protein.

Lumbar spondylolysis is one of the common diseases of low back pain caused by spinal surgery. Its treatment options vary depending on different conditions, from early conservative ones to late surgical ones. There are still disputes over various conservative treatments, choice of surgical methods and the biomechanics of different internal fixation techniques to repair spondylolysis. Therefore, this review summarizes the clinical outcomes of previous clinical treatments of lumbar spondylolysis and the biomechanical characteristics of various techniques to find the mechanical and evidence-based clinical data that may facilitate the treatment of lumbar spondylolysis.

The real physical image of the affected limb, which is difficult to move in the traditional mirror training, can be realized easily by the rehabilitation robots. During this training, the affected limb is often in a passive state. However, with the gradual recovery of the movement ability, active mirror training becomes a better choice. Consequently, this paper took the self-developed shoulder joint rehabilitation robot with an adjustable structure as an experimental platform, and proposed a mirror training system completed by next four parts. First, the motion trajectory of the healthy limb was obtained by the Inertial Measurement Units (IMU). Then the variable universe fuzzy adaptive proportion differentiation (PD) control was adopted for inner loop, meanwhile, the muscle strength of the affected limb was estimated by the surface electromyography (sEMG). The compensation force for an assisted limb of outer loop was calculated. According to the experimental results, the control system can provide real-time assistance compensation according to the recovery of the affected limb, fully exert the training initiative of the affected limb, and make the affected limb achieve better rehabilitation training effect.
Electromyography ; Humans ; Movement ; Muscle Strength ; Robotics ; Shoulder Joint ; Stroke Rehabilitation

Objective:To investigate the effect of 5.8 GHz radiofrequency (RF) radiation on learning and memory along with hippocampal synaptic plasticity in rats, in order to provide theoretical and experimental references for scientific evaluation of potential hazards of 5.8 GHz RF radiation.Methods:A total of 56 healthy adult male Sprague-Dawley rats were randomly divided into sham exposure group ( n=28) and RF exposure group ( n=28). RF groups were exposed to 5.8 GHz RF for 1 h each day in 15 d or 30 d continuously, and the whole-body absorption rate was 1.15 W/kg. The learning and memory ability of rats was tested by Morris water maze (MWM). The hippocampal structure of rats was observed by Nissl stain. The density of dendritic spines in CA1 region of hippocampus was detected by Golgi stain. The expression of synaptic related protein (PSD95, Synaptophysin) in hippocampus was detected by Western blot. The level of hippocampal neurotransmitters was detected by liquid chromatography-mass spectrometry. Results:In MWM experiments, at 15 d and 30 d after RF exposure, there was no statistically significant difference between sham group and RF group in the escape latency, frequency of crossing plateau, percentage of stay time in plateau quadrant and latency of first arrival to the plateau ( P>0.05). Besides, the structure and the number of neurons in the hippocampus, the density of apical and basal dendritic spines of pyramidal neurons in the CA1 region (apical: 5.10±0.20, 4.89±0.24, 4.58±0.27, 4.49±0.24, and basal: 4.81±0.17, 4.79±0.34, 4.20±0.27, 4.22±0.17, named as Sham 15 d group, RF 15 d group, Sham 30 d group, RF 30 d group, respectively), the expression of PSD95 and Synaptophysin and the level of multiple kinds of neurotransmitters in the hippocampus had no significant changes ( P>0.05). Conclusions:In this study, 5.8 GHz RF radiation has no significant influence on the spatial learning and memory ability along with the synaptic plasticity of hippocampal neurons of rats.

OBJECTIVE: To investigate the effects of Hippo signaling pathway on lung injury repair of mesenchymal stem cells (MSC) in acute respiratory distress syndrome (ARDS) and its mechanism. METHODS: Mouse bone marrow-derived MSC (mMSCs) cell lines with low expression of large tumor suppressor 2 (LATS2) were constructed by lentiviral vector transfection. Male C57BL/6 mice aging 6-8 weeks old were divided into four groups according to random number table (n = 36). The ARDS animal model (ARDS group) was reproduced by intratracheally injection of 2 g/L lipopolysaccharide (LPS) 50 μL, the normal saline (NS) control group was injected with an equal volume of NS. After 4 hours of model reproduction, 5×10⁴ mMSCs transfected with blank lentivirus vector (MSC-shcontrol group) or shLATS2 lentivirus vector (MSC-shLATS2 group) were transplanted intratracheally, while NS control group and ARDS group were injected with equal volume of phosphate buffered saline (PBS). Mice were sacrificed at 3, 7, and 14 days after modeling, and lung tissue and bronchoalveolar lavage fluid (BALF) were harvested. Near-infrared fluorescence imaging, immunofluorescence staining and Western Blot were used to track mMSCs in lung tissue. Retension and proportion of mMSC differentiation into type II alveolar epithelial cells (AEC II) were evaluated. Lung tissue wet weight/body weight ratio (LWW/BW) and total protein (TP) and albumin (ALB) in BALF were determined to reflect pulmonary edema. The expression of Occludin protein in lung epithelium was tested by Western Blot to reflect permeability of epithelium. The levels of interleukins (IL-1β, IL-6, IL-10) in BALF were assessed by enzyme-linked immunosorbent assay (ELISA) to reflect lung inflammation. Hematoxylin-eosin (HE) staining and modified Masson staining were carried out, and the scores were assessed to reflect lung injury and evaluate pulmonary fibrosis. RESULTS: The signal intensity of isolated lung fluorescence images at 3 days in the MSC-shLATS2 group was significantly higher than that in the MSC-shcontrol group (fluorescence intensity: 0.039±0.005 vs. 0.017±0.002, P < 0.05), the number of green fluorescent protein (GFP)-positive cells in lung tissue was also significantly higher than that in the MSC-shcontrol group (cells/HP: 29.65±6.98 vs. 17.50±4.58, P < 0.05), but they all decreased with time; and the proportion of mMSCs differentiated into AEC II was significantly increased [(64.12±15.29)% vs. (19.64±3.71)%, P < 0.05]. Compared with the NS control group, the levels of surface active protein C (SPC) and Occludin protein in the ARDS group were significantly decreased, LWW/BW ratio and TP, ALB and inflammatory factors levels in BALF were significantly increased; extensive alveolar and interstitial edema, hemorrhage and diffuse inflammatory cell infiltration were found in lung tissue, and the lung injury score was significantly increased; collagen fibers were deposited in alveolar septum and alveolar cavity, and pulmonary fibrosis score was also increased significantly. Compared with the ARDS group, the expression levels of SPC and Occludin at 14 days in the MSC-shcontrol group and the MSC-shLATS2 group were significantly increased (SPC/β-actin: 0.51±0.12, 0.68±0.10 vs. 0.27±0.08, Occludin/β-actin: 0.49±0.19, 0.79±0.11 vs. 0.25±0.08, all P < 0.05), TP, ALB, IL-1β, IL-6 levels in BALF at 3 days were significantly decreased [TP (g/L): 8.08±1.72, 5.12±0.87 vs. 12.55±2.09; ALB (g/L): 0.71±0.21, 0.44±0.18 vs. 1.18±0.29, IL-1β (ng/L): 99.26±14.32, 60.11±8.58 vs. 161.86±25.17, IL-6 (ng/L): 145.54±13.29, 101.74±11.55 vs. 258.79±27.88, all P < 0.05], and IL-10 was significantly increased (ng/L: 190.83±22.61, 316.65±37.88, both P < 0.05). Furthermore, all the above parameters in the MSC-shLATS2 group were significantly improved as compared with those in the MSC-shcontrol group (all P < 0.05). LWW/BW ratio in the MSC-shLATS2 group was significantly lower than that in the ARDS group and the MSC-shcontrol group (mg/g: 9.85±1.51 vs. 16.78±1.92, 14.88±1.74, both P < 0.05). CONCLUSIONS Inhibiting Hippo signaling pathway by low expression of LATS2 could promote the retention of mMSCs in lung tissue and differentiation into AEC II cells of ARDS mice, improve pulmonary edema and alveolar epithelial permeability, regulate pulmonary inflammatory response, and alleviate pathological damage and fibrosis of lung tissue.
Animals ; Hippo Signaling Pathway ; Lung Injury/prevention & control* ; Male ; Mesenchymal Stem Cells/metabolism* ; Mice ; Mice, Inbred C57BL ; Protein Serine-Threonine Kinases/metabolism* ; Respiratory Distress Syndrome/metabolism* ; Signal Transduction