154 research outputs found
J-R FRACTURE TOUGHNESS OF NUCLEAR PIPING MATERIALS UNDER EXCESSIVE SEISMIC LOADING CONDITION
ABSTRACT This study investigated the loading rate effect on the fracture resistance under cyclic loading conditions to clearly understand the fracture behavior of piping materials under excessive seismic conditions. J-R fracture toughness tests were conducted under monotonic and cyclic loading conditions at various displacement rates at room temperature (RT) and the operating temperature of nuclear power plants (NPPs), i.e., 316Β°C. SA508 Gr. 1a low-alloy steel (LAS) and SA312 TP316 stainless steel (SS) piping materials were used for the tests. The fracture resistance under a reversible cyclic load was considerably lower than that under monotonic load regardless of test temperature, material, and loading rate. Under both cyclic and monotonic loading conditions, the fracture behavior of SA312 TP316 SS was independent of the loading rate at both RT and 316Β°C. For SA508 Gr. 1a LAS, the loading rate effect on the fracture behavior was appreciable at 316Β°C under both cyclic and monotonic loading conditions. However, the loading rate effect diminished when the cyclic load ratio (R) was -1. Thus, it was recognized that the fracture behavior of piping materials, including seismic loading characteristics, can be evaluated when tested under a cyclic load of R = -1 at a quasi-static loading rate
Prospective Multi-Center Trial for the Efficacy of Ecabet Sodium on the Relief of Dyspepsia in Korean Patients with Chronic Gastritis
Anti-peptic and anti-inflammatory actions of ecabet sodium might be beneficial in either improving gastritis or relieving dyspeptic symptoms. This study was designed to evaluate the clinical efficacy of ecabet sodium on dyspeptic symptoms and to elucidate the molecular mechanism attributable to symptom relief in patients with chronic gastritis. Two hundred and sixty eight chronic gastritis patients with persistent dyspepsia received ecabet sodium 1 g b.i.d. for 2 weeks, after which dyspeptic symptoms were reassessed with a questionnaires as before. The changes of interleukin-8 (IL-8), inducible nitric oxide synthase (iNOS), prostaglandin E2 (PGE2), and vascular endothelial growth factor (VEGF) levels in gastric juices were measured by ELISA. The changes of nitrotyrosine in gastric mucosa were measured by immunohistochemical staining. The most common dyspeptic symptom in Korean patients with chronic gastritis was epigastric soreness (76.8%), which was improved significantly after ecabet sodium treatment (81.7%, p<0.001). Ecabet sodium was more effective in patients with epigastric pain than vague abdominal discomfort (p = 0.02), especially in patients with old age. Complete relief of discomfort was more highly achieved in patients with positive Helicobacter pylori than without (p = 0.01). In spite of clear tendency that the decreased levels of IL-8, iNOS, and PGE2 and increased levels of VEGF were measured in gastric juices after ecabet sodium treatment, no statistical significance was noted, which might be due to high inter-individual variations. The nitrotyrosine expressions were significantly decreased after ecabet sodium treatment than before (p<0.01). In conclusion, ecabet sodium treatment was very useful for the relief of dyspeptic symptoms in chronic gastritis, to which both attenuated inflammatory and enhanced regenerative mechanisms were contributive
The First Case of X-linked Alpha-thalassemia/Mental Retardation (ATR-X) Syndrome in Korea
Mutation of the ATRX gene leads to X-linked alpha-thalassemia/mental retardation (ATR-X) syndrome and several other X-linked mental retardation syndromes. We report the first case of ATR-X syndrome documented here in Korea. A 32-month-old boy came in with irritability and fever. He showed dysmorphic features, mental retardation and epilepsy, so ATR-X syndrome was considered. Hemoglobin H inclusions in red blood cells supported the diagnosis and genetic studies confirmed it. Mutation analysis for our patient showed a point mutation of thymine to cytosine on the 9th exon in the ATRX gene, indicating that Trp(C), the 220th amino acid, was replaced by Ser(R). Furthermore, we investigated the same mutation in family members, and his mother and two sisters were found to be carriers
Effect of sodium stearoyl-2-lactylate supplementation on lactation performance, blood-biochemical profile, and economic efficacy of mid-lactation Holstein cows
Objective This study was done to evaluate the effect of sodium stearoyl-2-lactylate (SSL) supplementation in a total mixed ration (TMR) on the lactation performance, blood parameters, and economic efficacy of mid-lactation Holstein cows. Methods Twenty-four cows (body weight 647Β±11.7 kg) were randomly divided into 4 treatment groups, with six cows per group. The dietary treatments were as follows: basal diet (CON); CON+17.5 g of top dressed SSL (treatment [TRT] 0.05); CON+35 g of SSL (TRT 0.1); and CON+70 g of SSL (TRT 0.2) per 35 kg TMR. Results The highest level of SSL supplementation (TRT 0.2) significantly improved milk yield during the second period compared to the TRT 0.05 group (5 to 8 wks; 33.28 vs 31.09 kg/d), during the third period compared to both the CON and TRT 0.05 groups (p<0.05) (9 to 13 wks; 32.59 vs 30.64 and 30.01 kg/d) and during the overall experimental period compared to both the CON and TRT 0.05 groups (p<0.05) (1 to 13 wks; 33.43 vs 32.06 and 31.40 kg/d), respectively. No negative effects on hematological or biochemical parameters were observed due to SSL supplementation. Considering both the milk fat and protein content, the total milk price was set at 1,073.60 (TRT 0.05), 1,085.60 (TRT 0.1), 1,086.10 (TRT 0.2), and 1,064.20 (CON) won/L, with consequent total milk profits of β1.7%, 5.4%, and 3.5% for the TRT 0.05, TRT 0.1, and TRT 0.2 diet, respectively, compared to those in the CON diet. Conclusion The milk sales revenue related to SSL supplementation of the TRT 0.1 diet was increased by up to 5.4% compared to the milk sales revenue of the CON diet. Therefore, 0.1% SSL supplementation might be effective and profitable during the mid-lactation period of cows, without producing adverse effects
Catheter ablation of atrial fibrillation in Korea: results from the Korean Heart Rhythm Society Ablation Registry for Atrial Fibrillation (KARA)
Background
This study aims to investigate the current status of AF (atrial fibrillation) catheter ablation in Korea.
Methods
The patients who underwent AF catheter ablation from September 2017 to December 2019 were prospectively enrolled from 37 arrhythmia centers. Demographic data, procedural characteristics, the extent of catheter ablation, acute success of the ablation lesion set, rate and independent risk factor for recurrence of AF were analyzed.
Results
A total of 2402 AF patients [paroxysmal AF (PAF) 45.7%, persistent AF (PeAF) 43.1% and redo AF 11.2%] were included. Pulmonary vein isolation (PVI) was performed in 2378 patients (99%) and acute success rate was 97.9%. Additional non-PV ablation (NPVA) were performed in 1648 patients (68.6%). Post-procedural complication rate was 2.2%. One-year AF-free survival rate was 78.6% and the PeAF patients showed poorer survival rate than the ones with other types (PeAF 72.4%, PAF 84.2%, redo AF 80.0%). Additional NPVA did not influence the recurrence of AF in the PAF patients (PVI 17.0% vs. NPVA 14.6%, P value 0.302). However, it showed lower AF recurrence rate in the PeAF patients (PVI 34.9% vs. NPVA 24.4%, P value 0.001). Valvular heart disease, left atrial diameter, PeAF, PVI alone, need of NPVA for terminating AF, and failed ablation were independent predictors of AF recurrence.
Conclusions
Additional NPVA was associated better rhythm outcome in the patients with PeAF, not in the ones with PAF. The independent risk factors for AF recurrence in Korean population were similar to previous studies. Further research is needed to discover optimal AF ablation strategy.This nationwide registry study was supported by a grant from the Korean Heart Rhythm Society 2017
Diagnostic algorithm for papillary urothelial tumors in the urinary bladder
Papillary urothelial neoplasms with deceptively bland cytology cannot be easily classified. We aimed to design a new algorithm that could differentiate between these neoplasms based on a scoring system. We proposed a new scoring system that enables to reproducibly diagnose non-invasive papillary urothelial tumors. In this system, each lesion was given individual scores from 0 to 3 for mitosis and cellular thickness, from 0 to 2 for cellular atypia, and an additional score for papillary fusion. These scores were combined to form a summed score allowing the tumors to be ranked as follows: 0β1 = UP, 2β4 = low malignant potential (LMP), 5β7 = low-grade transitional cell carcinoma (TCC), and 8β9 = high-grade TCC. In addition to the scoring system, ancillary studies of MIB and p53 indexes with CK20 expression pattern analyses were compared together with clinical parameters. The MIB index was strongly correlated with disease progression. Four of the 22 LMP patients (18.2%) had late recurrences, two of these four (9.1%) had progression to low-grade carcinoma. The MIB index for LMP patients was strongly associated with recurrence (recurrence vs. non-recurrence, 16.5 vs. 8.1, pβ<β0.001). The proposed scoring system could enhance the reproducibility to distinguish papillary urothelial neoplasms
Polyacrylamide Functionalized Graphene Oxide/Alginate Beads for Removing Ciprofloxacin Antibiotics
Ciprofloxacin (CPX), a widely used antibiotic, was removed by synthesizing graphene oxide/calcium alginate–polyacrylamide (GO/Ca-Alg2–PAM) beads, a three-dimensional double-network complex. The synthesis of GO/Ca-Alg2–PAM beads was performed by crosslinking and cation exchange mechanisms with graphene oxide (GO), sodium alginate (Na-Alg), and polyacrylamide (PAM). The properties of GO/Ca-Alg2–PAM beads were confirmed using field emission scanning electron microscopy, Fourier transform infrared spectroscopy, and a thermogravimetric analysis. Furthermore, isothermal adsorption experiments were performed and fitted using three isothermal adsorption models (Langmuir, Freundlich, and Temkin). The adsorption isotherm experimental data fit well with the Langmuir isotherm model with a qm value of 6.846 mg/g. In addition, the spontaneous reaction of the CPX adsorption using GO/Ca-Alg2–PAM was confirmed by temperature-dependent experiments
Enhanced Controlled Transdermal Delivery of Torasemide Using Ethylene-vinyl Acetate
Purpose: To develop an ethylene-vinyl acetate (EVA) matrix system
containing a permeation enhancer for enhanced transdermal delivery of
torasemide. Methods: The solubility of torasemide was studied at
various volume fraction of polyethylene glycol (PEG) 400. The effect of
drug concentration was tested at 1.0, 2.0 and 3.0 %, respectively while
the effect of temperature on drug release from drug-EVA matrix was
evaluated at 27, 32, 37 and 42 oC. To increase pore size and
flexibility of the EVA matrix, plasticizers with citrate and phthalate
groups were added to the matrix containing torasemide. To improve the
penetration of torasemide from the EVA matrix across the skin,
enhancers (propylene glycol derivatives, fatty acids, glycerides,
pyrrolidones and non-ionic surfactants) were incorporated into the
torasemide-EVA matrix. The effects of the enhancers on the skin
penetration were evaluated using Franz diffusion cell fitted with the
intact excised rat skin. Results: Solubility and permeation of
torasemide was highest at 40 %v/v PEG 400. The release rate of drug
from drug-EVA matrix increased with increased loading dose and
temperature. Release rate was proportional to the square root of
loading dose. The activation energy (Ea), which was derived from the
slope of log P versus 1000/T, was 14.95 kcal/mol for 2.0% loading dose.
Among the plasticizers used, diethyl phthalate showed the highest
release rate of torasemide. Among the enhancers used, polyoxyethylene
2-oleyl ether showed the greatest enhancing effect. Conclusion: For the
enhanced controlled transdermal delivery of torasemide, the application
of the EVA matrix containing plasticizer and penetration enhancer could
be useful in the development of a transdermal drug delivery system
Immunostimulatory Activities of Theobromine on Macrophages via the Activation of MAPK and NF-κB Signaling Pathways
Theobromine is mainly found in plant foods, such as tea; the primary source of theobromine is the seeds of the Theobroma cacao tree. Theobromine is an alkaloid belonging to the methylxanthine class of drugs, and it is similar to theophylline and caffeine. Theobromine is known for its efficacy and role in health and disorder prevention. We evaluated the effects of theobromine on macrophage function, including the phosphorylation of mitogen-activated protein kinases (MAPKs) and nuclear factor-kappa B (NF-κB). Theobromine significantly stimulated the production of nitric oxide (NO) and prostaglandin E2 through immune responses, which relate to the increased expression of inducible nitric oxide synthase and cyclooxygenase-2. Additionally, theobromine increased the production of inflammatory cytokines, including tumor necrosis factor-α and interleukin-6 in macrophages. Additionally, theobromine induced the translocation and activity of NF-κB in a concentration-dependent manner. Consistent with these results, the phosphorylation level of MAPKs was increased in theobromine-stimulated macrophages. Collectively, these data revealed that theobromine acts as an immune response stimulator via the NF-κB and MAPKs signaling pathways. Thus, theobromine might have protective effects against inflammatory disorders
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