Subsidence Performance of the Bioactive Glass-Ceramic (CaO-SiO2-P2O5-B2O3) Spacer in Terms of Modulus of Elasticity and Contact Area: Mechanical Test and Finite Element Analysis.

OBJECTIVE: The objective of this study is to evaluate the subsidence performance of a bioactive glass-ceramic (CaO-SiO2-P2O5-B2O3) spacer in terms of its modulus of elasticity and contact area using mechanical tests and finite element analysis. METHODS: Three spacer three-dimensional models (Polyether ether ketone [PEEK]-C: PEEK spacer with a small contact area; PEEK-NF: PEEK spacer with a large contact area; and Bioactive glass [BGS]-NF: bioactive glass-ceramic spacer with a large contact area) are constructed and placed between bone blocks for compression analysis. The stress distribution, peak von Mises stress, and reaction force generated in the bone block are predicted by applying a compressive load. Subsidence tests are conducted for three spacer models in accordance with ASTM F2267. Three types of blocks measuring 8, 10, and 15 pounds per cubic foot are used to account for the various bone qualities of patients. A statistical analysis of the results is conducted using a one-way Analysis of variance and post hoc analysis (Tukey's Honestly Significant Difference) by measuring the stiffness and yield load. RESULTS: The stress distribution, peak von Mises stress, and reaction force predicted via the finite element analysis are the highest for PEEK-C, whereas they are similar for PEEK-NF and BGS-NF. Results of mechanical tests show that the stiffness and yield load of PEEK-C are the lowest, whereas those of PEEK-NF and BGS-NF are similar. CONCLUSIONS: The main factor affecting subsidence performance is the contact area. Therefore, bioactive glass-ceramic spacers exhibit a larger contact area and better subsidence performance than conventional spacers.

Biomechanical Comparison of Multilevel Lumbar Instrumented Fusions in Adult Spinal Deformity According to the Upper and Lower Fusion Levels: A Finite Element Analysis.

Multilevel lumbar fusion with posterior pedicle screw fixation is a widely performed surgical procedure for the management of adult spinal deformity. However, there has not been a comprehensive biomechanical study on the different types of fusion levels in terms of stability and possible complications. We aimed to investigate the biomechanical properties of multilevel lumbar fusion according to different types of upper and lower fusion levels. Six different types of fusions were performed using three-dimensional finite element models. Type A and B referred to the group of which upper fusion level was L1 and T10, respectively. Subtype 1, 2, and 3 referred to the group of which lower fusion level was L5, S1, and ilium, respectively (A1, L1-L5; A2, L1-S1; A3, L1-ilium; B1, T10-L5; B2, T10-S1; B3, T10-ilium). Flexion, extension, axial rotation, and lateral bending moments were applied, and the risk of screw loosening and failure and adjacent segment degeneration (ASD) was analyzed. Stress at the bone-screw interface of type B3 was lowest in overall motions. The risk of screw failure showed increasing pattern as the upper and lower levels extended in all motions. Proximal range of motion (ROM) increased as the lower fusion level changed from L5 to S1 and the ilium. For axial rotation, type B3 showed higher proximal ROM (16.2°) than type A3 (11.8°). In multilevel lumbar fusion surgery for adult spinal deformity, adding iliac screws and increasing the fusion level to T10-ilium may lower the risk of screw loosening. In terms of screw failure and proximal ASD, however, T10-ilium fusion has a higher potential risk compared with other fusion types. These results will contribute for surgeons to provide adequate patient education regarding screw failure and proximal ASD, when performing multilevel lumbar fusion.

Combined Deep Learning Techniques for Mandibular Fracture Diagnosis Assistance.

Mandibular fractures are the most common fractures in dentistry. Since diagnosing a mandibular fracture is difficult when only panoramic radiographic images are used, most doctors use cone beam computed tomography (CBCT) to identify the patient's fracture location. In this study, considering the diagnosis of mandibular fractures using the combined deep learning technique, YOLO and U-Net were used as auxiliary diagnostic methods to detect the location of mandibular fractures based on panoramic images without CBCT. In a previous study, mandibular fracture diagnosis was performed using YOLO learning; in the detection performance result of the YOLOv4-based mandibular fracture diagnosis module, the precision score was approximately 97%, indicating that there was almost no misdiagnosis. In particular, fractures in the symphysis, body, angle, and ramus tend to be distributed in the middle of the mandible. Owing to the irregular fracture types and overlapping location information, the recall score was approximately 79%, which increased the detection of undiagnosed fractures. In many cases, fractures that are clearly visible to the human eye cannot be grasped. To overcome these shortcomings, the number of undiagnosed fractures can be reduced using a combination of the U-Net and YOLOv4 learning modules. U-Net is advantageous for the segmentation of fractures spread over a wide area because it performs semantic segmentation. Consequently, the undiagnosed case in the middle of the mandible, where YOLO was weak, was somewhat supplemented by the U-Net module. The precision score of the combined module was 95%, similar to that of the previous method, and the recall score improved to 87%, as the number of undiagnosed cases was reduced. Through this study, the performance of a deep learning method that can be used for the diagnosis of the mandibular bone has been improved, and it is anticipated that as an auxiliary diagnostic inspection device, it will assist dentists in making diagnoses.

Tone Image Classification and Weighted Learning for Visible and NIR Image Fusion.

In this paper, to improve the slow processing speed of the rule-based visible and NIR (near-infrared) image synthesis method, we present a fast image fusion method using DenseFuse, one of the CNN (convolutional neural network)-based image synthesis methods. The proposed method applies a raster scan algorithm to secure visible and NIR datasets for effective learning and presents a dataset classification method using luminance and variance. Additionally, in this paper, a method for synthesizing a feature map in a fusion layer is presented and compared with the method for synthesizing a feature map in other fusion layers. The proposed method learns the superior image quality of the rule-based image synthesis method and shows a clear synthesized image with better visibility than other existing learning-based image synthesis methods. Compared with the rule-based image synthesis method used as the target image, the proposed method has an advantage in processing speed by reducing the processing time to three times or more.

Stereospecific inhibition of AMPK by (R)-crizotinib induced changes to the morphology and properties of cancer and cancer stem cell-like cells.

Crizotinib is used in the clinic for treating patients with ALK- or ROS1-positive non-small-cell lung carcinoma. The objective of the present study was to determine if crizotinib enantiomers could induce changes to the properties of cancer and cancer stem cell (CSC)-like cells at a high concentration (∼ 3 µM). While (R)-crizotinib induced changes in morphologies or sizes of cells, (S)-crizotinib did not. Pretreatment with (R)-crizotinib suppressed the proliferation of cancer or CSC-like cells in vitro and tumor growth in vivo. In vivo administration of (R)-crizotinib inhibited the growth of tumors formed from CSC-like cells by 72%. %. Along with the morphological changes induced by (R)-crizotinib, the expression levels of CD44 (NCI-H23 and HCT-15), ALDH1 (NCI-H460), nanog (PC-3), and Oct-4A (CSC-like cells), which appear to be specific marker proteins, were greatly changed, suggesting that changes in cellular properties accompanied the morphological changes in the cells. The expression levels of Snail, Slug, and E-cadherin were also greatly altered by (R)-crizotinib. Among several signal transduction molecules examined, AMPK phosphorylation appeared to be selectively inhibited by (R)-crizotinib. BML-275 (an AMPK inhibitor) and AMPKα2 siRNA efficiently induced morphological changes to all types of cells examined, suggesting that (R)-crizotinib might cause losses of characteristics of cancer or CSCs via inhibition of AMPK. These results indicate that (R)-crizotinib might be an effective anticancer agent that can cause alteration in cancer cell properties.

Automatic Detection of Mandibular Fractures in Panoramic Radiographs Using Deep Learning.

Mandibular fracture is one of the most frequent injuries in oral and maxillo-facial surgery. Radiologists diagnose mandibular fractures using panoramic radiography and cone-beam computed tomography (CBCT). Panoramic radiography is a conventional imaging modality, which is less complicated than CBCT. This paper proposes the diagnosis method of mandibular fractures in a panoramic radiograph based on a deep learning system without the intervention of radiologists. The deep learning system used has a one-stage detection called you only look once (YOLO). To improve detection accuracy, panoramic radiographs as input images are augmented using gamma modulation, multi-bounding boxes, single-scale luminance adaptation transform, and multi-scale luminance adaptation transform methods. Our results showed better detection performance than the conventional method using YOLO-based deep learning. Hence, it will be helpful for radiologists to double-check the diagnosis of mandibular fractures.

Influence of group resilience on job satisfaction among Korean nurses: A cross-sectional study.

PURPOSE: This study examined whether the individual and organisational factors of ecological systems theory are associated with job satisfaction among nurses in South Korea. BACKGROUND: Nursing shortages and high turnover rates are a global issue in healthcare settings, and job satisfaction is significantly associated with the turnover intention of nurses. Therefore, efforts to promote job satisfaction are needed to decrease the high turnover rates among nurses and promote care quality and patient safety. DESIGN: A cross-sectional study was performed. This paper adhered to the STROBE guidelines. METHODS: A sample of 438 nurses working in five secondary or tertiary hospitals was surveyed. The study instruments included work-life balance, resilience, insomnia and job satisfaction. RESULTS: Using multilevel analysis, both individual and organisational factors were associated significantly with job satisfaction, and variance at the group level accounted for 19.98% of the total variance of job satisfaction. Among the individual factors, marital status and work-life balance were significantly associated with job satisfaction. At the organisational level, the group mean resilience score was significantly associated with job satisfaction (p < .05). CONCLUSION: The psychosocial characteristics of individual nurses and their affiliated groups (nursing units) were significant in explaining the job satisfaction of nurses. RELEVANCE TO CLINICAL PRACTICE: Both individual-focused and group-focused interventions are needed to improve job satisfaction and decrease the turnover intention.

Risk of rod fracture according to cross-link position in pedicle subtraction osteotomy (PSO): A finite element study.

PURPOSE: The purpose of this study is to investigate the effect of the cross-link position on the rod fracture phenomenon during pedicle subtraction osteotomy (PSO) surgery using finite element model (FEM). METHODS: A three-dimensional finite element model of a lumbar spine with sagittal imbalance was constructed using computed tomography data of a 65-year-old female patient. After simulating the standard PSO at the L4 level, we constructed four models, specifically a model without a cross-link and three models with a cross-link at three different sites. The peak von Mises stress (PVMS) of the rod around the PSO site was measured after applying physiological loads (flexion, extension, axial rotation, and lateral bending) in each model. RESULTS: The measured PVMS outcomes at the PSO site were 135.8, 135.9, 208.9, and 384.7 MPa for model 1, 2, 3, and 4 during flexion, and 180.0, 180.1, 210.1, and 445.7 MPa during extension. These results show that when the cross-link is located at the PSO site, the rod stress at the PSO site increases significantly during flexion and extension. As the cross-link moved away from the PSO site, the effect on the rod stress decreased. When the cross-link was placed two levels away from the PSO site, the rod stress was scarcely affected. CONCLUSION: When the cross-link during PSO surgery was positioned two levels away from the PSO site, the risk of rod fracture did not increase.

[Factors associated with Self-Rated Health in Metabolic Syndrome and Relationship between Sleep Duration and Metabolic Syndrome Risk Factors].

PURPOSE: Purpose was to explore associations between sleep duration and metabolic syndrome (MS) risks, and to determine factors associated with self-rated health (SRH) of adults with MS compared to other adults. METHODS: This is a secondary data analysis based on the Fifth Korea National Health and Nutrition Examination Survey KNHANES V (N=12662). Study instruments included sleep duration, MS risk factors, SRH and health-related quality of life (HRQoL). RESULTS: Mean age of participants was 43.68±12.26 years. Fifty-eight percent were women, and 18.3% were identified as having MS. Systolic blood pressure (SBP), diastolic blood pressure (DBP), and SRH were significantly different according to sleep duration (p<.05) among all participants. In the non MS group, male gender, younger age (19~30 and 41~50 age brackets) upper income level, sufficient sleep duration, and high density lipoprotein (HDL) were positively associated with SRH, whereas, lower education levels (≤middle school), glucose level, and waist circumference were negatively associated with SRH (p<.05). In the MS group, lower income, lower education levels (≤middle school), glucose level, and waist circumference were negatively associated with SRH, whereas, having an occupation was positively associated with SRH (p<.05). CONCLUSION: Results suggest that tailored approaches are required for prevention and control of MS and sleep duration of each individual should be considered rather than applying standardized guidelines. However, as sleep quality was not included in the analysis, further investigations regarding influence of sleep quality on MS and SRH and controlling for other lifestyle and health behavior factors are required.