University of Ulsan Open Access Korea
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Evaluating YOLO Models for Efficient Crack Detection in Concrete Structures Using Transfer Learning
No full textThe You Only Look Once (YOLO) network is considered highly suitable for real-time object detection tasks due to its characteristics, such as high speed, single-shot detection, global context awareness, scalability, and adaptability to real-world conditions. This work introduces a comprehensive analysis of various YOLO models for detecting cracks in concrete structures, aiming to assist in the selection of an optimal model for future detection and segmentation tasks. The YOLO models are initially trained on a dataset containing both images with and without cracks, producing a generalized model capable of extracting abstract features beneficial for crack detection. Subsequently, transfer learning is employed using a dataset that reflects real-world conditions, such as occlusions, varying crack sizes, and rotations, to further refine the model. Crack detection in concrete remains challenging due to the wide variation in crack sizes, aspect ratios, and complex backgrounds. To achieve optimal performance, we test different versions of YOLO, a state-of-the-art single-shot detector, and aim to balance inference speed and mean average precision (mAP). Our results indicate that YOLOv10 demonstrates superior performance, achieving a mean average precision (mAP) of 74.52% with an inference time of 19.5 milliseconds per image, making it the most effective among the models tested
Localized Photodynamic Therapy Using a Chlorin e6-Embedded Silicone-Covered Self-Expandable Metallic Stent as a Palliative Treatment for Malignant Esophageal Strictures
No full textLocalized photodynamic therapy (PDT) uses a polymeric-photosensitizer (PS)-embedded, covered self-expandable metallic stent (SEMS). PDT is minimally invasive and a noteworthy potential alternative for treating esophageal strictures, where surgery is not a viable option. However, preclinical evidence is insufficient, and optimized irradiation energy dose ranges for localized PDT are unclear. Herein, we validated the irradiation energy doses of the SEMS (embedded in a PS using chlorin e6 [Ce6] and covered in silicone) and PDT-induced tissue changes in a rat esophagus. Cytotoxicity and phototoxicity in the Ce6-embedded SEMS piece with laser irradiation were significantly higher than that of the silicone-covered SEMS with or without laser and the Ce6-embedded silicone-covered SEMS without laser groups (all p < 0.001). Moreover, surface morphology, atomic changes, and homogeneous coverage of the Ce6-embedded silicone-covered membrane were confirmed. The ablation range of the porcine liver was proportionally increased with the irradiation dose (all p < 0.001). The ablation region was identified at different irradiation energy doses of 50, 100, 200, and 400 J/cm2. The in vivo study in the rat esophagus comprised a control group and 100, 200, and 400 J/cm2 energy-dose groups. Finally, histology and immunohistochemistry (TUNEL and Ki67) confirmed that the optimized Ce6-embedded silicone-covered SEMS with selected irradiation energy doses (200 and 400 J/cm2) effectively damaged the esophageal tissue without ductal perforation. The polymeric PS-embedded silicone-covered SEMS can be easily placed via a minimally invasive approach and represents a promising new approach for the palliative treatment of malignant esophageal strictures
The Electrical, Optical, Heating Property and Electromagnetic Wave Shield Effect of TiO2/Ag/TiO2 Thin Films
No full textTransparent TiO2 single layer and TiO2/Ag/TiO2(TAT) tri-layer films were deposited by DC and RF magnetron sputter on a polyimide substrate at room temperature. During the TAT deposition, the thickness of the TiO2 layer was kept at 20 nm, while the Ag interlayer was varied as 10, 15, 20 nm to investigate the effect of Ag thickness on the figure of merit value which is decided by the visible transmittance and sheet resistance of the films. The compared FOM values revealed that the TiO2 films with a 15 nm thick Ag interlayer had an ideal tri-layer structure with a higher figure of merit of 8.96×10-3 Ω-1. In a planar heater test, when the bias voltage of 15 V was applied to the TiO2 20 nm/Ag 15 nm/TiO2 20 nm films, their steady state temperature increased to 108.1 °C. After the heat radiation test, the films retained constantly stable optical and electrical properties. In addition, the TAT films showed superior electromagnetic interference shielding effectiveness up to 45 db, which is above the specifications grade of commercial electromagnetic interference shielding products. From the observed experimental results, it is supposed that TAT films with an optimal Ag interlayer of 15 nm deposited on PI films can be applied as transparent electrodes for rollable display devices and as planar heating elements, as well as electromagnetic shielding glass in future autonomous cars
Clinical validation of enhanced CT imaging for distal radius fractures through deep learning based interpolation and thickness reduction
No full textBackgrounds: Distal radius fractures (DRFs) account for approximately 18% of fractures in patients 65 years and older. While plain radiographs are standard, the value of high-resolution computed tomography (CT) for detailed imaging crucial for diagnosis, prognosis, and intervention planning, and increasingly recognized. High-definition 3D reconstructions from CT scans are vital for applications like 3D printing in orthopedics and for the utility of mobile C-arm CT in orthopedic diagnostics. However, concerns over radiation exposure and suboptimal image resolution from some devices necessitate the exploration of advanced computational techniques for refining CT imaging without compromising safety. Purpose: This study aims to utilize conditional Generative Adversarial Networks (cGAN) to improve the resolution of 3mm CT images (CT enhancement). Methods: Following institutional review board approval, 3mm-1mm paired CT data from 11 patients with DRFs were collected. cGAN was used to improve the resolution of 3mm CT images to match that of 1mm images (CT enhancement). Two distinct methods were employed for training and generating CT images. In Method 1, a 3mm CT raw image was used as input with the aim of generating a 1mm CT raw image. Method 2 was designed to emphasize the difference value between the 3mm and 1mm images; using a 3mm CT raw image as input, it produced the difference in image values between the 3mm and 1mm CT scans. Both quantitative metrics, such as peak signal-to-noise ratio (PSNR), mean squared error (MSE), and structural similarity index (SSIM), and qualitative assessments by two orthopedic surgeons were used to evaluate image quality by assessing the grade (1~4, which low number means high quality of resolution). Results: Quantitative evaluations showed that our proposed techniques, particularly emphasizing the difference value in Method 2, consistently outperformed traditional approaches in achieving higher image resolution. In qualitative evaluation by two clinicians, images from method 2 showed better quality of images (grade: method 1, 2.7; method 2, 2.2). And more choice was found in method 2 for similar image with 1mm slice image (15 vs 7, p=201). Conclusion: In our study utilizing cGAN for enhancing CT imaging resolution, the authors found that the method, which focuses on the difference value between 3mm and 1mm images (Method 2), consistently outperformed traditional techniques. Keywords: distal radius fracture, high-resolution computed tomography, conditional generative adversarial networks, enhancementDocto
Chronic cough management: Practical guidelines and PICO-based evidence for treatment
No full textThis part reviews the management of chronic cough and proposes a management algorithm. Despite proven improvements in quality of life following chronic cough treatment, a clear understanding of the disease and the evidence for the efficacy of some treatments remain vague. Eight key questions regarding the treatment in the uncertain areas were systematically addressed based on the PICO framework and applying the GRADE system for evidence synthesis to provide the strength of recommendation and quality of evidence for key questions, with narrative components for the description of other chronic cough treatment including non-pharmacological therapy. Practical diagrams were developed to facilitate clinical decision-making on treatment. Our guideline introduces the concept of the cough management process for guiding practitioners to assess chronic cough using a holistic approach
Vacuum-assisted reforming cathode interlayer orientation for efficient and stable perovskite solar cells
No full textThe cathode interlayer (CIL) is vital for enhancing the performance of inverted (p-i-n) perovskite solar cells (PSCs) by preventing charge recombination and ion diffusion, thereby achieving superior efficiency. Herein, we introduce cost-effective perylene-diimide (PDI)-based CILs-PDIN-S, PDIN, and PDIN-L-with varying spacer lengths. Among them, PDIN-S exhibits exceptional attributes in thermal evaporation processability, optical absorbance, and charge transfer capabilities. Molecular orientations of PDIN-S are studied through two deposition techniques: vacuum thermal evaporation (VE) and spin-coating (SC). The face-on orientation observed in PDIN-S (VE) confers significant advantages, including improved π-π stacking, efficient charge carrier transfer, reduced interfacial resistance, and inhibited ion diffusion. Furthermore, PDIN-S (VE) also lowers the energy barrier towards cathode, boosting PSC efficiency to 23.82%. Moreover, it enhances both thermal and light stability, maintaining over 90% initial efficiency for 2036 h at 85 °C and sustaining 80% efficiency for 1848 h under continuous illumination. Our application of a straightforward VE method enables the manipulation of molecular orientation, resulting in a concurrent enhancement of efficiency and stability. These findings underscore the potential of PDIN-S as a promising component for highly efficient and stable PSCs
The HLA-C*14:152 Allele Was Identified Using a Next-Generation Sequencing Method
No full textHLA-C*14:152 differs from HLA-C*14:02:01:01 by a non-synonymous nucleotide substitution in exon 5
Percutaneous insertion of long-covered biliary stents in patients with malignant duodenobiliary stricture
No full textObjective: To investigate the technical feasibility, safety, and efficacy of a long-covered biliary stent in patients with malignant duodenobiliary stricture.
Methods: This retrospective study enrolled 57 consecutive patients (34 men, 23 women; mean age, 64 years; range, 32-85 years) who presented with malignant duodenobiliary stricture between February 2019 and November 2020. All patients were treated with a long (18 or 23 cm)-covered biliary stent.
Results: The biliary stent deployment was technically successful in all 57 patients. The overall adverse event rate was 17.5% (10 of 57 patients). Successful internal drainage was achieved in 55 (96.5%) of 57 patients. The median patient survival and stent patency times were 99 days (95% confidence interval [CI], 58-140 days) and 73 days (95% CI, 60-86 days), respectively. Fourteen (25.5%) of the fifty-five patients presented with biliary stent dysfunction due to sludge (n = 11), tumor overgrowth (n = 1), collapse of the long biliary stent by a subsequently inserted additional duodenal stent (n = 1), or rapidly progressed duodenal cancer (n = 1). A univariate Cox proportional hazards model did not reveal any independent predictor of biliary stent patency.
Conclusions: Percutaneous insertion of a subsequent biliary stent was technically feasible after duodenal stent insertion. Percutaneous insertion of a long-covered biliary stent was safe and effective in patients with malignant duodenobiliary stricture.
Clinical relevance statement: In patients with malignant duodenobiliary stricture, percutaneous insertion of a long-covered biliary stent was safe and effective regardless of duodenal stent placement.
Key points: • Percutaneous insertion of long-covered biliary stents in patients with malignant duodenobiliary stricture is a safe and effective procedure. • Biliary stent deployment was technically successful in all 57 patients and successful internal drainage was achieved in 55 (96.5%) of 57 patients. • The median patient survival and stent patency times were 99 days and 73 days, respectively, after placement of a long-covered biliary stent in patients with duodenobiliary stricture
Patient-specific, deliverable, and self-expandable surgical guide development and evaluation using 4D printing for laparoscopic partial nephrectomy
No full textAccurate lesion diagnosis through computed tomography (CT) and advances in laparoscopic or robotic surgeries have increased partial nephrectomy survival rates. However, accurately marking the kidney resection area through the laparoscope is a prevalent challenge. Therefore, we fabricated and evaluated a 4D-printed kidney surgical guide (4DP-KSG) for laparoscopic partial nephrectomies based on CT images. The kidney phantom and 4DP-KSG were designed based on CT images from a renal cell carcinoma patient. 4DP-KSG were fabricated using shape-memory polymers. 4DP-KSG was compressed to a 10 mm thickness and restored to simulate laparoscopic port passage. The Bland-Altman evaluation assessed 4DP-KSG shape and marking accuracies before compression and after restoration with three operators. The kidney phantom’s shape accuracy was 0.436 ± 0.333 mm, and the 4DP-KSG’s shape accuracy was 0.818 ± 0.564 mm before compression and 0.389 ± 0.243 mm after restoration, with no significant differences. The 4DP-KSG marking accuracy was 0.952 ± 0.682 mm before compression and 0.793 ± 0.677 mm after restoration, with no statistical differences between operators (p = 0.899 and 0.992). In conclusion, our 4DP-KSG can be used for laparoscopic partial nephrectomies, providing precise and quantitative kidney tumor marking between operators before compression and after restoration
Structural variability of the cerebral cortex in schizophrenia and its association with clinical symptoms
No full textBackground: Substantial evidence indicates structural abnormalities in the cerebral cortex of patients with schizophrenia (SCZ), although their clinical implications remain unclear. Previous case-control studies have investigated group-level differences in structural abnormalities, although the study design cannot account for interindividual differences. Recent research has focused on the association between the heterogeneity of the cerebral cortex morphometric features and clinical heterogeneity.
Methods: We used neuroimaging data from 420 healthy controls and 695 patients with SCZ from seven studies. Four cerebral cortex measures were obtained: surface area, gray matter volume, thickness, and local gyrification index. We calculated the coefficient of variation (CV) and person-based similarity index (PBSI) scores and performed group comparisons. Associations between the PBSI scores and cognitive functions were evaluated using Spearman's rho test and normative modeling.
Results: Patients with SCZ had a greater CV of surface area and cortical thickness than those of healthy controls. All PBSI scores across cortical measures were lower in patients with SCZ than in HCs. In the patient group, the PBSI scores for gray matter volume and all cortical measures taken together positively correlated with the full-scale IQ scores. Patients with deviant PBSI scores for gray matter volume and all cortical measures taken together had lower full-scale IQ scores than those of other patients.
Conclusions: The cerebral cortex in patients with SCZ showed greater regional and global structural variability than that in healthy controls. Patients with deviant similarity of cortical structural profiles exhibited a lower general intelligence than those exhibited by the other patients