Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
      More Filters
      Clear All
      More Filters
      Source
    • Language
124 result(s) for "Gun-Woo Lee"
Sort by:
The effect of smoking on the outcomes of arthroscopic microfracture for osteochondral lesions of the talus
Smoking is known to negatively affect the outcomes of orthopedic procedures, but its impact on arthroscopic microfracture for osteochondral lesions of the talus (OLT) remains unclear. We aimed to compare clinical outcomes and the status of repaired cartilage following arthroscopic microfracture for small to medium-sized OLT in smokers versus nonsmokers. We enrolled 239 patients (250 ankles), dividing them into smoker (56 patients, 59 ankles) and nonsmoker groups (183 patients, 191 ankles). The primary outcome measure was the FAOS (Foot and Ankle Outcome Score). The AOFAS (American Orthopaedic Foot & Ankle Society) ankle-hindfoot scale, SF-36 PCS (Short Form-36 Physical Component Summary) score, and VAS (Visual Analog Scale) for pain were included as secondary outcomes. Preoperative magnetic resonance imaging (MRI) assessed lesion size, location, and subchondral cyst presence. Postoperative cartilage repair status was evaluated using the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score on 3.0-T MRI. The mean OLT sizes were 74.4 mm2 in smokers and 69.9 mm2 in nonsmokers on preoperative MRI. The mean age was 35.9 years in smoker group and 38.8 years in nonsmoker group (p = 0.157). The overall mean follow-up duration was 83.6 months (range, 24-217), with no significant intergroup difference (p = 0.582). There was no significant difference in primary and secondary clinical outcome variables between the two groups at the final follow-up (p > 0.05). In terms of postoperative MRI, 75 ankles (18 smokers, 57 nonsmokers) assessed repaired cartilage status and the mean total MOCART score was significantly lower in smokers (65.0, range 30.0-85.0) compared with nonsmokers (73.7, range 40.0-95.0; p = 0.027). Particularly, the smoker group had significantly lower MOCART scores for surface for repair tissue and signal intensity of the repair tissue variables, respectively (p = 0.019, p = 0.008). Although smoker group showed worse status of repaired cartilage on postoperative MRI, the smoker group reported comparable clinical outcomes to those of the nonsmoker group following arthroscopic microfracture for small to medium-sized OLT over a mean follow-up of 7 years. However, caution should be taken in interpreting our conclusion and further larger studies are needed for robust conclusions.
Outcome comparison of rotational ankle fractures: Supination external rotation versus pronation external rotation
Ankle fractures are among the most common types of fractures in the orthopaedic field, and the Lauge-Hansen classification is commonly used to categorize rotational ankle fractures. This study evaluated and compared the clinical and radiological outcomes of surgically treated supination external rotation (SER) and pronation external rotation (PER) injuries of grades III or IV. We retrospectively reviewed and enrolled 104 patients who underwent open reduction and internal fixation for SER or PER injuries classified as Grades III or IV between January 2016 and December 2021, all performed at a single center. Of these, 72 belonged to the SER group and 32 to the PER group. The average postoperative follow-up durations were 31.3 months (range, 24 to 74) for the SER group and 32.1 months (range, 24 to 71) for the PER group. Clinical and radiological outcomes were assessed 24 months after surgery and compared between the two groups. Details of concomitant surgical procedures performed and postoperative complications were also evaluated. All clinical outcome variables, including the Foot and Ankle Outcome Score, Visual Analog Scale for pain, and ankle range of motion, were comparable between the two groups. Similarly, no statistically significant differences were observed in the development of post-traumatic arthritis or in the frequency of syndesmotic widening 24 months postoperatively. However, the time required for fibular union was significantly longer in the PER group, taking 5.6 ± 2.2 months compared to 3.4 ± 1.3 months in the SER group on average (p < 0.001). Our study demonstrated that both types of rotational ankle fractures can achieve equivalent clinical and radiological outcomes with surgical treatment. Given the prolonged time to fibular union in the PER group, careful monitoring during postoperative follow-up is required.
Gate-controlled amplifiable ultraviolet AlGaN/GaN high-electron-mobility phototransistor
Gate-controlled amplifiable ultraviolet phototransistors have been demonstrated using AlGaN/GaN high-electron-mobility transistors (HEMTs) with very thin AlGaN barriers. In the AlGaN/GaN HEMTs, the dark current between the source and drain increases with increasing thickness of the AlGaN barrier from 10 to 30 nm owing to the increase in piezoelectric polarization-induced two-dimensional electron gas (2-DEG). However, the photocurrent of the AlGaN/GaN HEMT decreases with increasing thickness of the AlGaN barrier under ultraviolet exposure conditions. It can be observed that a thicker AlGaN barrier exhibits a much higher 2-DEG than the photogenerated carriers at the interface between AlGaN and GaN. In addition, regardless of the AlGaN barrier thickness, the source–drain dark current increases as the gate bias increases from − 1.0 to + 1.0 V. However, the photocurrent of the phototransistor with the 30 nm thick AlGaN barrier was not affected by the gate bias, whereas that of the phototransistor with 10 nm thick AlGaN barrier was amplified from reduction of the gate bias. From these results, we suggest that by controlling the gate bias, a thin AlGaN barrier can amplify/attenuate the photocurrent of the AlGaN/GaN HEMT-based phototransistor.
Monolithic GaN-Based Dual-Quantum-Well LEDs with Size-Controlled Color-Tunable White-Light Emission
We report a monolithic GaN-based light-emitting diode (LED) platform capable of color-tunable white-light emission via LED size scaling. By varying the LED size from 800 µm to 50 µm, the injection current density was effectively controlled under constant driving current, enabling precise modulation of carrier distribution within a dual-composition multi-quantum well (MQW) structure. The active layer consists of five lower In0.15Ga0.85N/GaN QWs for blue emission and strain induction, and an upper In0.3Ga0.7N/GaN single QW engineered for red-orange emission. The strain imposed by lower QWs promotes indium segregation in the last QW through spinodal decomposition, resulting in a broadened emission spanning from ~500 nm to 580 nm. High-resolution TEM and EDX analyses directly confirmed the indium segregation and phase-separated structure of the last QW. Spectral analysis revealed that larger devices exhibited dominant emission at 580 nm with a correlated color temperature (CCT) of 2536 K and a CIE coordinate of (0.501, 0.490). As LED size decreased, increased hole injection allowed recombination to occur in deeper QWs, resulting in a blueshift to 450 nm and a CCT of 9425 K with CIE (0.224, 0.218) in the 50 × 50 µm2 LED. This approach enables phosphor-free white-light generation with tunable color temperatures and chromaticities using a single wafer, offering a promising strategy for compact, adaptive solid-state lighting applications.
The E3 ligase C-CBL inhibits cancer cell migration by neddylating the proto-oncogene c-Src
Neddylation is a cellular process that covalently conjugates substrate proteins with the small ubiquitin-like molecule NEDD8. As neddylation is required for fast turnover of proteins in proliferating cancer cells, the neddylation process is currently regarded as a potential target for cancer therapy. However, little is known about the role of neddylation in cancer invasion and metastasis. Unexpectedly, we here found that the neddylation blockade stimulates migration of lung cancer and glioblastoma cells. Mechanistically, C-CBL acts as the E3 ligase for neddylation of the proto-oncogene c-Src. After neddylation, c-Src is poly-ubiquitinated and degraded through the proteasome, which inhibits the PI3K–AKT pathway responsible for cell migration. In human lung cancer tissues, the downregulation of C-CBL was associated with c-Src/AKT, cancer metastasis, and poor survival in patients. Therefore, C-CBL is likely to play a tumor suppressive role by antagonizing a robust oncogenic signaling driven by c-Src. This study provides new insight about the role of neddylation in cancer metastasis. It also implies that the metastasis risk should be carefully evaluated before the clinical application of neddylation inhibitors as anticancer regimens.
Diagnostic Modality in Spine Disease: A Review
Spine diseases are common and exhibit several causes, including degeneration, trauma, congenital issues, and other specific factors. Most people experience a variety of symptoms of spine diseases during their lifetime that are occasionally managed with conservative or surgical treatments. Accurate diagnosis of the spine pathology is essential for the appropriate management of spine disease, and various imaging modalities can be used for the diagnosis, including radiography, computed tomography (CT), magnetic resonance imaging (MRI), and other studies such as EOS, bone scan, single photon emission CT/CT, and electrophysiologic test. Patient (or case)-specific selection of the diagnostic modality is crucial; thus, we should be aware of basic information and approaches of the diagnostic modalities. In this review, we discuss in detail, about diagnostic modalities (radiography, CT, MRI, electrophysiologic study, and others) that are widely used for spine disease.
Older Korean men with inadequate vitamin D status have lower odds of radiologic osteoarthritis
Most studies on osteoarthritis (OA) and vitamin D status were performed in Whites with relatively adequate vitamin D status. Associations may differ by baseline 25-hydroxyvitamin D (25(OH)D) and race. We assessed the odds of OA and joint pain according to vitamin D status in Korean adults ≥ 50 years of age in the nationally representative Korea National Health and Nutrition Examination Survey ( n  = 8575). Agreement between radiologic OA (ROA) and self-reported OA were also assessed. Multivariate logistic regression was performed and participants were stratified by sex. Adults with serum 25(OH)D < 12 ng/mL and 12 to < 20 ng/mL had 26% and 18% lower odds of knee ROA, respectively, compared to those with 25(OH)D ≥ 20 ng/mL. Similar results were observed in men, but not women. No associations were found between 25(OH)D and knee ROA severity, lumbar spine ROA, symptomatic OA, or knee pain. Sensitivity of self-reported OA was low (27%), indicating a weak possibility of reverse causation. Prospective studies are required to identify the possible causality of vitamin D on OA in Korean men.
Does gender influence the outcomes of total ankle arthroplasty in patients with ankle osteoarthritis?
Background Total ankle arthroplasty has progressed as a treatment option for patients with ankle osteoarthritis. However, no studies have been conducted to evaluate the effect of gender on the outcome. The purpose of the present study was to evaluate outcomes, survivorship, and complications rates of total ankle arthroplasty, according to gender differences. Methods This study included 187 patients (195 ankles) that underwent mobile-bearing HINTEGRA prosthesis at a mean follow-up of 7.5 years (range, 4 to 14). The two groups consisted of a men’s group (106 patients, 109 ankles) and a women’s group (81 patients, 86 ankles). Average age was 64.4 years (range, 45 to 83). Results Clinical scores on the Ankle Osteoarthritis Scale for pain and disability, and American Orthopaedic Foot and Ankle Society ankle-hindfoot score improved and the difference was not statistically significant between the two groups at the final follow-up. There were no significant differences in complication rates and implant survivorship between the two groups. The overall survival rate was 96.4% in men and 93.4% in women at a mean follow-up of 7.5 years ( p = 0.621). Conclusions Clinical outcomes, complication rates, and survivorship of total ankle arthroplasty were comparable between men and women. These results suggest that gender did not seem to affect outcomes of total ankle arthroplasty in patients with ankle osteoarthritis. Level of evidence Therapeutic level III
Comparison of 2-octyl cyanoacrylate skin adhesive and interrupted polypropylene sutures for wound closure in total ankle arthroplasty
Background Adhesive skin materials have increasingly been used in orthopedic surgery. We aimed to compare the efficacy and safety of skin adhesive (2-octyl cyanoacrylate and polymer mesh, Dermabond Prineo) and interrupted polypropylene sutures for wound closure in patients undergoing total ankle arthroplasty (TAA). Methods We prospectively enrolled 107 consecutive patients (108 ankles) undergoing TAA and divided them into two groups: skin adhesive group (36 ankles) and suture group (72 ankles). The primary outcome assessment included wound complications and patient satisfaction for wound cosmesis. The secondary outcome assessment included duration of surgery, length of hospital stay, and the Ankle Osteoarthritis Scale (AOS) pain and disability score. Results There was one case of allergic contact dermatitis, three cases of wound dehiscence, and one case of superficial surgical site infection in the skin adhesive group. Among them, one case each with allergic contact dermatitis and wound dehiscence finally progressed to deep surgical site infection. Three cases of wound dehiscence were also reported in the suture group; however, there was no case of surgical site infection. Patient satisfaction for wound cosmesis was significantly higher in the skin adhesive group than in the suture group ( p  = 0.001). There was no statistically significant difference between the groups in terms of secondary outcomes ( p  > 0.05). Conclusions Although the use of Dermabond Prineo showed better patient satisfaction for wound cosmesis, it showed significantly high wound complication rates and no other clinical benefits compared to interrupted polypropylene suture in TAA. Our results suggest that awareness of the possibility of wound complications is necessary when Dermabond Prineo is used in TAA.
Identification of L5 vertebra on lumbar spine radiographs using deep learning
Objective Deep learning is an advanced machine-learning approach that is used in several medical fields. Here, we developed a deep learning model using an object detection algorithm to identify the L5 vertebra on anteroposterior lumbar spine radiographs, and assessed its detection accuracy. Methods We retrospectively recruited 150 participants for whom both anteroposterior whole-spine and lumbar spine radiographs were available. The anteroposterior lumbar spine radiographs of these patients were used as the input data. Of the 150 images, 105 (70%) were randomly selected as the training set, and the remaining 45 (30%) were assigned to the validation set. YOLOv5x, of the YOLOv5 family model, was used to detect the L5 vertebra area. Results The mean average precisions 0.5 and 0.75 of the trained L5 detection model were 99.2% and 96.9%, respectively. The model’s precision was 95.7% and its recall was 97.8%. Furthermore, 93.3% of the validation data were correctly detected. Conclusion Our deep learning model showed an outstanding ability to identify L5 vertebrae.