• Journal of Hydrogen and New Energy
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• v.34 no.5
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• pp.413-420
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• 2023

Holmium-doped TiO₂ nanotubes (Ho-TNTs) were manufactured through anodization treatment and electrochemical deposition, and optimization experiments were conducted using various Holmium doping concentrations and time as variables. Surface as well as electrochemical characteristics were analyzed to study the prepared photocatalysts. Ho-TNTs were found to exist only in anatase phase through X-ray diffraction analysis. Ho-TNTs with 0.01 wt% 100 seconds shows a photocurrent density of 3.788 mA/cm² and an effective photo-conversion efficiency (PCE) of 4.30%, which is more efficient than pure TiO₂ nanotubes (pure-TNTs) (at bias potential 1.5 V vs. Hg/HgO). The photocatalytic activity of the aforementioned Ho-TNTs for hydrogen production was evaluated with the result of -29.20 µmol/h·cm².

• Childhood Kidney Diseases
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• v.27 no.2
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• pp.105-110
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• 2023

Purpose: To analyze electrocardiograms (ECGs) of patients with a salt-losing tubulopathy (SLT) and to determine the frequency and risk factors for long QT and arrhythmia. Methods: A total of 203 patients aged <19 years with SLT, specifically Bartter syndrome and Gitelman syndrome, who had a 12-lead ECG were included in this retrospective study. We analyzed the presence of an arrhythmia or prolonged corrected QT (QTc) on ECGs obtained for these patients. Demographic and laboratory data were compared between patients with abnormal and normal ECG findings. Results: Out of the 203 SLT patients, 38 (18.7%) underwent electrocardiography and 10 (40.0%) of 25 patients with inherited SLT had abnormal ECG findings, including prolonged QTc and arrhythmias. The abnormal ECG group had significantly lower serum potassium levels than the normal group (median [interquartile range]: 2.50 mmol/L [2.20-2.83] vs. 2.90 mmol/L [2.70-3.30], P=0.036), whereas other serum chemistry values did not show significant differences. The cutoff level for a significant difference in QTc interval was serum potassium level <2.50 mmol/L. One cardiac event occurred in a 13-year-old boy, who developed paroxysmal supraventricular tachycardia and underwent cardiac ablation. No sudden cardiac deaths occurred in this cohort. Conclusions: The incidence of ECG abnormalities in patients with inherited SLT was 40.0%, whereas the ECG screening rate was relatively low (18.7%). Therefore, we recommend ECG screening in patients with inherited SLT, especially in those with serum potassium level <2.50 mmol/L.

• Korean Journal of Radiology
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• v.22 no.1
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• pp.97-105
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• 2021

Objective: The present study aimed to investigate the association between myocardial blood flow (MBF) quantified by dynamic CT myocardial perfusion imaging (CT-MPI) and the increments in heart rate (HR) after stress in patients without obstructive coronary artery disease. Materials and Methods: We retrospectively included 204 subjects who underwent both dynamic CT-MPI and coronary CT angiography (CCTA). Patients with more than minimal coronary stenosis (diameter ≥ 25%), history of myocardial infarction/revascularization, cardiomyopathy, and microvascular dysfunction were excluded. Global MBF at stress was measured using hybrid deconvolution and maximum slope model. Furthermore, the HR increments after stress were recorded. Results: The median radiation dose of dynamic CT-MPI plus CCTA was 5.5 (4.5-6.8) mSv. The median global MBF of all subjects was 156.4 (139.8-180.4) mL/100 mL/min. In subjects with HR increment between 10 to 19 beats per minute (bpm), the global MBF was significantly lower than that of subjects with increment between 20 to 29 bpm (153.3 mL/100 mL/min vs. 171.3 mL/100 mL/min, p = 0.027). This difference became insignificant when the HR increment further increased to ≥ 30 bpm. Conclusion: The global MBF value was associated with the extent of increase in HR after stress. Significantly higher global MBF was seen in subjects with HR increment of ≥ 20 bpm.

• Journal of Periodontal and Implant Science
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• v.54 no.1
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• pp.37-43
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• 2024

Purpose: The inflammatory response due to inflammatory cytokines, bacterial pathogens, and the altered lipoprotein metabolism in patients with periodontitis indicates that infection with periodontal anaerobic bacteria may influence atherogenesis in vitro and in vivo. We aimed to explore the effect of periodontitis concerning clinical and ultrasound markers of early atherosclerosis. Methods: In this case-control study, a total of 30 systemically healthy adults (15 with periodontitis and 15 without periodontitis) over 40 years of age were studied. Periodontitis was determined by measuring the clinical attachment level (CAL) and radiographic bone loss (RBL). Conventional cardiovascular risk factors, including body mass index, serum levels of total cholesterol (TCH), triglycerides (TG), and high-density and low-density lipoprotein (HDL and LDL, respectively) cholesterol were evaluated. Carotid artery intima-media thickness (IMT) was measured using ultrasonography. Results: The mean values of the CAL and carotid IMT were 5.02±0.9 mm and 0.084±0.01 cm vs. 1.6±0.61 mm and 0.072±0.02 cm in the periodontitis and healthy groups, respectively, reflecting statistically significant differences (P=0.001 and P=0.037, respectively). There were statistically significant differences in the serum levels of TCH, TG, and LDL between the 2 groups (P=0.017). The CAL and RBL were positively associated with carotid IMT and serum cholesterol levels, except for HDL, whereas tooth loss was not associated with any markers (P<0.05). Compared to the healthy group, participants with periodontitis exhibited 2.09 times higher odds (95% confidence interval, 1.22-3.59) of having subclinical atherosclerosis. Conclusions: The presence of periodontitis increased the risk of atherosclerosis.

• Korean Journal of Radiology
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• v.24 no.7
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• pp.626-639
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• 2023

Objective: To investigate the association of clinical, pathologic, and magnetic resonance imaging (MRI) variables with progressive disease (PD) during neoadjuvant chemotherapy (NAC) and distant metastasis-free survival (DMFS) in patients with triple-negative breast cancer (TNBC). Materials and Methods: This single-center retrospective study included 252 women with TNBC who underwent NAC between 2010 and 2019. Clinical, pathologic, and treatment data were collected. Two radiologists analyzed the pre-NAC MRI. After random allocation to the development and validation sets in a 2:1 ratio, we developed models to predict PD and DMFS using logistic regression and Cox proportional hazard regression, respectively, and validated them. Results: Among the 252 patients (age, 48.3 ± 10.7 years; 168 in the development set; 84 in the validation set), PD was occurred in 17 patients and 9 patients in the development and validation sets, respectively. In the clinical-pathologic-MRI model, the metaplastic histology (odds ratio [OR], 8.0; P = 0.032), Ki-67 index (OR, 1.02; P = 0.044), and subcutaneous edema (OR, 30.6; P = 0.004) were independently associated with PD in the development set. The clinical-pathologic-MRI model showed a higher area under the receiver-operating characteristic curve (AUC) than the clinical-pathologic model (AUC: 0.69 vs. 0.54; P = 0.017) for predicting PD in the validation set. Distant metastases occurred in 49 patients and 18 patients in the development and validation sets, respectively. Residual disease in both the breast and lymph nodes (hazard ratio [HR], 6.0; P = 0.005) and the presence of lymphovascular invasion (HR, 3.3; P < 0.001) were independently associated with DMFS. The model consisting of these pathologic variables showed a Harrell's C-index of 0.86 in the validation set. Conclusion: The clinical-pathologic-MRI model, which considered subcutaneous edema observed using MRI, performed better than the clinical-pathologic model for predicting PD. However, MRI did not independently contribute to the prediction of DMFS.

• Hip & pelvis
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• v.35 no.1
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• pp.32-39
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• 2023

Purpose: A staged revision with placement of a temporary antibiotic-loaded cement spacer after removal of the implant is the "gold standard" for treatment of chronic prosthetic joint infection (PJI). It enables local delivery of antibiotics, maintenance of limb-length and mobility, easier reimplantation. However, bacterial colonization of spacers and mechanical complications can also occur. The aim of this study is to evaluate functional results and infection control in two-stage treatment of total hip arthroplasty (THA) PJI with and without a spacer. Materials and Methods: A retrospective review of 64 consecutive patients was conducted: 34 underwent two-stage revision using a cement spacer (group A), 30 underwent two-stage revision without a spacer (group B). At the final follow-up, functional evaluation of patients with a THA in site, without PJI recurrence, was performed using the Harris hip score (HHS). Measurement of limb-length and off-set discrepancies was performed using anteroposterior pelvic X-rays. Results: Most patients in group B were older with more comorbidities preoperatively. Thirty-three patients (97.1%) in group A underwent THA reimplantation versus 22 patients (73.3%) in group B (P<0.001). No significant differences in limb-length and off-set were observed. The results of functional evaluation performed during the final follow-up (mean, 41 months) showed better function in patients in group A (mean HHS, 76.3 vs. 55.9; P<0.001). Conclusion: The use of antibiotic-loaded cement spacer seems superior in terms of functional outcomes and reimplantation rate. Resection arthroplasty might be reserved as a first-stage procedure in patients who are unfit, who might benefit from a definitive procedure.

• Korean Journal of Radiology
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• v.21 no.7
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• pp.829-837
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• 2020

Objective: The aim of this study was to investigate the prognostic value of the maximum standardized uptake value (SUV_max) measured while restaging with F-18 fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) to predict the 3-year post-recurrence survival (PRS) in patients with recurrent gastric cancer after curative surgical resection. Materials and Methods: In total, 47 patients with recurrent gastric cancer after curative resection who underwent restaging with ¹⁸F-FDG PET/CT were included. For the semiquantitative analysis, SUV_max was measured over the visually discernable ¹⁸F-FDG-avid recurrent lesions. Cox proportional-hazards regression models were used to predict the 3-year PRS. Differences in 3-year PRS were assessed with the Kaplan-Meier analysis. Results: Thirty-nine of the 47 patients (83%) expired within 3 years after recurrence in the median follow-up period of 30.3 months. In the multivariate analysis, SUV_max (p = 0.012), weight loss (p = 0.025), and neutrophil count (p = 0.006) were significant prognostic factors for 3-year PRS. The Kaplan-Meier curves demonstrated significantly poor 3-year PRS in patients with SUV_max > 5.1 than in those with SUV_max ≤ 5.1 (3-year PRS rate, 3.5% vs. 38.9%, p < 0.001). Conclusion: High SUV_max on restaging with ¹⁸F-FDG PET/CT is a poor prognostic factor for 3-year PRS. It may strengthen the role of ¹⁸F-FDG PET/CT in further stratifying the prognosis of recurrent gastric cancer.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.281-288
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• 2024

Background: Venoarterial extracorporeal membrane oxygenation (ECMO) is a key treatment method used with patients in cardiac arrest who do not respond to medical treatment. A critical step in initiating therapy is the insertion of ECMO cannulas. Peripheral ECMO cannulation methods have been preferred for extracorporeal cardiopulmonary resuscitation (ECPR). Methods: Patients who underwent ECPR at Daegu Catholic University Medical Center between January 2017 and May 2023 were included in this study. We analyzed the impact of 2 different peripheral cannulation strategies (surgical cutdown vs. percutaneous cannulation) on various factors, including survival rate. Results: Among the 99 patients included in this study, 66 underwent surgical cutdown, and 33 underwent percutaneous insertion. The survival to discharge rates were 36.4% for the surgical cutdown group and 30.3% for the percutaneous group (p=0.708). The ECMO insertion times were 21.3 minutes for the surgical cutdown group and 10.3 minutes for the percutaneous group (p<0.001). The factors associated with overall mortality included a shorter low-flow time (hazard ratio [HR], 1.045; 95% confidence interval [CI], 1.019-1.071; p=0.001) and whether return of spontaneous circulation was achieved (HR, 0.317; 95% CI, 0.127-0.787; p=0.013). Low-flow time was defined as the time from the start of cardiopulmonary resuscitation to the completion of ECMO cannula insertion. Conclusion: No statistically significant difference in in-hospital mortality was observed between the surgical and percutaneous groups. However, regardless of the chosen cannulation strategy, reducing ECMO cannulation time was beneficial, as a shorter low-flow time was associated with significant benefits in terms of survival.

• Clinical and Experimental Vaccine Research
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• v.13 no.1
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• pp.35-41
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• 2024

Purpose: The effectiveness of coronavirus disease 2019 (COVID-19) vaccination schemes and the combination of vaccines of various platforms for administering booster doses is still being studied since it will depend on the population's response to vaccines. We aimed to evaluate the safety, protection, and immunogenicity of the Salvadorean population's third dose booster COVID-19 vaccine and the potential benefit of homologous vs. heterologous regimens. Materials and Methods: This is an analytical observational cohort study in a population aged 18 to 65 years that was primarily vaccinated with AstraZeneca, Sinovac, or Pfizer/BioNTech. Volunteers were recruited (n=223) and followed up for 3 months after receiving the 3rd vaccine (BNT162b2) as a booster. Adverse reactions were monitored, serum anti-spike immunoglobulin G (IgG) was assessed by chemiluminescence, and a polymerase chain reaction was carried out when subjects developed clinical signs. Results: The cohorts finally included 199 participants, and we observed only mild adverse effects in all cohorts. A significant increase in specific IgG levels was found after the booster dose in all cohorts. The heterologous scheme with Sinovac showed the greatest increase in antibody titer, and a decrease was observed in all participants after 3 months. During the follow-up period, 30 participants showed symptomatology compatible with COVID-19, but only four were laboratory-confirmed and they showed mild clinical signs. Conclusion: These findings indicate that the booster doses used were safe and promoted an immediate increase in immunogenicity, which decreased over time. The heterologous regimen showed stronger immunogenicity compared to the messenger RNA-based homologous scheme.

• Clinical Endoscopy
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• v.55 no.5
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• pp.630-636
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• 2022

Background/Aims: Transoral incisionless fundoplication (TIF) is an accepted anatomic treatment for gastroesophageal reflux disease in selected patients. In this report, we analyze our institution's programmatic allocation of resources during the safe implementation of TIF as a new procedure. Methods: A retrospective analysis of all patients who underwent TIF from January 2020 to February 2021 at our institution was performed. The process of initially allocating the operating room (OR) with overnight admission and postoperative esophagram for added safety, and subsequently transitioning TIF to the endoscopy suite (ES) as an outpatient procedure was described. Patient safety and outcomes were evaluated during transition. Results: Thirty patients who underwent TIF were identified. The mean age was 51.2±16.0 years. TIF was performed in an OR in nine patients (30%) and 21 (70%) in the ES. All the OR patients were admitted overnight and had routine esophagogram. In contrast, four (19%) from the ES group required clinically-indicated admission and three (14.2%) required esophagram. The mean procedure duration was significantly lower in the ES group (65.7 min vs. 84 min, p=0.02). Conclusions: A stepwise, resource-efficient process was described that allowed safe initiation of TIF as a new technique and its effective transition to a fully outpatient procedure.