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1.
Water Res ; 242: 120183, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37320874

RESUMEN

Urea reacts with chlorine to form chlorinated ureas (chloroureas), and fully chlorinated urea (tetrachlorourea) is further hydrolyzed into CO2 and chloramines. This study found that the oxidative degradation of urea by chlorination was enhanced by the pH swing, wherein the reaction proceeded under an acidic pH (e.g., pH = 3) in the first stage, and the solution pH was subsequently increased to a neutral or alkaline value (e.g., pH > 7) in the second-stage reaction. The degradation rate of urea by pH-swing chlorination increased with increasing chlorine dose and pH during the second-stage reaction. The pH-swing chlorination was based on the opposite pH dependence of sub-processes comprising urea chlorination. The formation of monochlorourea was favored under acidic pH conditions; however, the subsequent conversion into di- and trichloroureas was favored under neutral or alkaline pH conditions. The deprotonation of monochlorourea (pKa = 9.7 ± 1.1) and dichlorourea (pKa = 5.1 ± 1.4) was suggested to be responsible for the accelerated reaction in the second stage under increased pH conditions. pH-swing chlorination was also effective in degrading urea at low concentrations (micromolar levels). In addition, the total nitrogen concentration significantly decreased during the degradation of urea because of the volatilization of chloramines and the release of other gaseous nitrogen compounds.

2.
Taehan Yongsang Uihakhoe Chi ; 81(3): 688-700, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-36238614

RESUMEN

Purpose: To compare the incidence, survival rate, and CT findings of acute exacerbation (AE) of idiopathic pulmonary fibrosis (IPF) between patients with and without lung cancer. Materials and Methods: From June 2004 to July 2018, 89 consecutive patients diagnosed with IPF were included. Among them, 26 patients had IPF with lung cancer (IPF-LCA), and 63 patients had IPF alone. The clinical characteristics and CT findings associated with IPF, lung cancer, and AE were reviewed. Surgery and chemotherapy were performed for 6 and 23 cases of lung cancer, respectively, as the first- or second-line anticancer treatment. The overall survival, CT findings, disease-free period before AE, and duration from the onset of AE to death were compared. Results: The incidence of AE was 61.5% in the IPF-LCA group and 58.7% in the IPF group (p = 0.806). The mean overall survival in the IPF-LCA and IPF groups were 16.8 and 83.0 months, respectively (p < 0.001). The mean durations from the start of the lung cancer treatment to the onset of AE were 16.0 and 4.6 months in cases of surgical treatment and chemotherapy, respectively. In comparison of death from AE, the survival rate was significantly lower in the IPF-LCA group than in the IPF group (p = 0.008). In the CT findings associated with AE, the IPF-LCA group tended to have a peribronchial (p < 0.001) or asymmetric distribution (p = 0.016). Conclusion: In patients with IPF who develop lung cancer, the rate of death from AE is higher than that in patients with IPF alone. They tend to have unusual CT patterns associated with AE, such as a peribronchial or asymmetric distribution.

3.
J Infect Dev Ctries ; 12(4): 250-256, 2018 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-31851634

RESUMEN

INTRODUCTION: Vaccination is the most effective method of preventing infectious disease among healthcare workers (HCWs). Although HCWs are recommended to receive vaccination, the vaccination rates have been low. We sought to investigate the effect of HCWs' vaccination recommendation program by the types of enforcement and influencing factors on compliance, with the aim of enhancing their immunity. METHODOLOGY: First and second interventions were carried out. During the first intervention, vaccinations were recommended through official documents. Hepatitis B vaccination was mandatory. Diphtheria toxoid, acellular pertussis (Tdap) and Hepatitis A vaccinations were recommended without financial support. MMR and varicella vaccinations were recommended with fees for the antibody test were covered by the hospital. One-to-one consultation (OC) regarding vaccination was held in the second intervention. Aside from the OC, the second intervention followed the same procedure as the first intervention for the antibody tests and vaccination, but differed in that pertussis vaccination fees were covered. RESULTS: The immunization rates for infectious diseases were greater after the second intervention than the first intervention. The rate of immunized HCWs with hepatitis B virus was 100% at the end of the second intervention. The greatest increase in immunization rates from the first to the second intervention was that for pertussis, and the second greatest was that for hepatitis A. Age and working units were influencing factors on hepatitis A vaccine compliance. CONCLUSIONS: In order to increase vaccination rates, efforts must be made to deliver information to individual HCWs through OC as well as financial support including a mandatory policy.

4.
Asian-Australas J Anim Sci ; 31(1): 86-90, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28728393

RESUMEN

OBJECTIVE: This study was conducted to investigate the effects of dietary detoxified Rhus verniciflua sap (RVS) on production performance, egg quality, lipid fractions of egg yolk, liver and serum, and the profile of cecal microflora in laying hens. METHODS: Two hundred 52-week-old Hy-Line Brown layers were randomly divided into 4 groups with 5 replicates per group (2 hens per cage, 5 cages per replicate) and were provided with one of 4 experimental diets containing 0%, 0.05%, 0.1%, or 0.2% RVS, for 6 weeks. Due to unequal intervals of RVS doses, the interactive matrix language procedure of the SAS program was used to correct the contrast coefficients of orthogonal polynomials. RESULTS: There were no differences in feed intake and egg weight among the groups. Egg production increased (linearly and quadratically, p<0.05) with increasing levels of RVS. Eggshell thickness increased (linear, p<0.05) as the level of RVS in diets increased. The levels of blood cholesterol and activities of glutamic-oxaloacetic transaminase and glutamic-pyruvic transaminase were not altered by dietary treatments. Increasing level of RVS increased (linear, p<0.05) the populations of cecal lactic acid bacteria. The content of yolk cholesterol decreased (linear, p< 0.05) with increasing levels of dietary RVS, although there were no significant differences in each lipid fraction of the liver. CONCLUSION: This study indicates that dietary RVS could improve laying performance and eggshell quality, and affect cecal lactic acid bacteria in a dose-dependent manner.

5.
Korean J Crit Care Med ; 32(1): 29-38, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31723613

RESUMEN

BACKGROUND: Carbapenem-resistant Enterobacteriaceae (CRE) with acquired metallo ß-lactamase (MBL) resistance have been increasingly reported worldwide and associated with significant mortality and morbidity. Here, an outbreak of genetically related strains of Klebsiella pneumoniae producing the imipenemase (IMP)-1 MBL in a medical intensive care unit (MICU) in Korea is reported. METHODS: Since isolating carbapenem-resistant K. pneumoniae (CRKP) at the MICU of the hospital on August 10, 2011, surveillance cultures for CRE in 31 hospitalized patients were performed from August to September 2011. Carbapenem resistance was determined based on the disk diffusion method outlined in the Clinical and Laboratory Standards Institute guidelines. Polymerase chain reaction (PCR) was performed for genes coding for ß-lactamase. Associations among isolates were assessed via pulsed-field gel electrophoresis (PFGE). In addition, a surveillance study of environmental cultures and health-care workers (HCWs) was conducted in the MICU during the same time frame. RESULTS: During the study period, non-duplicated CRKP specimens were discovered in four patients in the MICU, suggestive of an outbreak. On August 10, 2011, CRKP was isolated from the sputum of a 79-year-old male patient who was admitted to the MICU. A surveillance study to detect additional CRE carriers by rectal swab revealed an additional three CRKP isolates. PCR and sequencing of the four isolates identified the presence of the IMP-1 gene. In addition, PFGE showed that the four isolated strains were genetically related. CRE was not identified in specimens taken from the hands of HCWs or other environmental sources during surveillance following the outbreak. Transmission of the carbapenemase-producing Enterobacteriaceae strain was controlled by isolation of the patients and strict contact precautions. CONCLUSIONS: This study shows that rapid and systemic detection of CRE and strict infection controls are important steps in preventing nosocomial transmission.

6.
Korean Circ J ; 44(2): 89-96, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24653738

RESUMEN

BACKGROUND AND OBJECTIVES: Excessive catecholamine causes the alteration of cardiac structure and function. This study evaluated if there is any difference in left ventricular hypertrophy (LVH) and QTc prolongation in conditions with pheochromocytoma and Takotsubo cardiomyopathy (TC). SUBJECTS AND METHODS: We reviewed the medical records of 20 pheochromocytoma patients for cardiovascular events prior to diagnosis. The patient's clinical history and electrocardiographic and echocardiographic findings were compared to those of 20 patients diagnosed with TC. RESULTS: Left ventricular (LV) mass index (133.3±37.8 vs. 113.3±17.3, p=0.031), relative wall thickness (0.55±0.15 vs. 0.47±0.07, p=032) and elevated blood pressure (BP) were more prominent in pheochromocytoma compared to TC. The mean creatinine kinase-MB elevation, reduced LV systolic function and ST segment changes were more prominent in the TC group compared to the pheochromocytoma groups (all p<0.05). The prevalence of QTc prolongation was high in patients with pheochromocytoma (45%) and TC (55%), and TC male patients appeared to have a more prolonged QTc interval. Urine epinephrine (r=0.844, p=0.004) and norepinephrine level (r=0.782, p=0.013) were significantly correlated with LV mass index, and the predictors for the QTc prolongation were male gender and the presence of LVH. CONCLUSION: A prolonged QTc was prominent in pheochromocytoma and TC regardless of BP and systolic LV function, and LVH was more prominent in pheochromocytoma than TC.

7.
Korean J Gastroenterol ; 63(1): 18-24, 2014 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-24463284

RESUMEN

BACKGROUND/AIMS: The incidence of colorectal cancer has been increasing every year in Korea. Irinotecan- or oxaliplatin-based regimens including biologic agents are known to be effective in patients with advanced colorectal cancer. But in practice, FOLFOX (combination of oxaliplatin, 5-fluorouracil, and leucovorin) or FOLFIRI (combination of irinotecan, 5-fluorouracil, and leucovorin) regimens without biologic agents are more commonly used in Korea due to of the high costs of biologic agents. The aim of this study was to evaluate the efficacy and toxicity of FOLFIRI following FOLFOX4 in patients with advanced colorectal cancer. METHODS: A total of 54 patients with advanced colorectal cancer who were treated between May 2005 and May 2013 with FOLFOX4 as first-line chemotherapy and with FOLFIRI as second-line chemotherapy at Kosin University Gospel Hospital (Busan, Korea) were reviewed retrospectively. RESULTS: A total of 54 patients received second-line FOLFIRI chemotherapy. Five patients (9.3%) had a partial response, 29 patients (53.7%) had a stable disease. The median overall survival was 8.90 months and the median time to progression was 4.33 months. Toxicities were tolerable. CONCLUSIONS: In a Korean population, FOLFIRI as second-line chemotherapy is effective and well tolerated in patients with advanced colorectal cancer after failure of FOLFOX4. Although the efficacy of FOLFIRI in this study was lower than that of second-line FOLFIRI with biologic agents, these results can help in the formulation of a treatment strategy for financially troubled patients.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Camptotecina/análogos & derivados , Neoplasias Colorrectales/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Camptotecina/administración & dosificación , Camptotecina/uso terapéutico , Neoplasias Colorrectales/mortalidad , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Fluorouracilo/uso terapéutico , Humanos , Inyecciones Intravenosas , Irinotecán , Leucovorina/administración & dosificación , Leucovorina/uso terapéutico , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Compuestos Organoplatinos/administración & dosificación , Compuestos Organoplatinos/uso terapéutico , Oxaliplatino , República de Corea , Estudios Retrospectivos , Análisis de Supervivencia
8.
Clin Hypertens ; 20: 10, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-26893913

RESUMEN

INTRODUCTION: Wall shear stress (WSS) is critically important in both vascular remodeling and atherosclerosis. Carotid intima-media thickness (IMT) and deformation parameters have been used as relevant indicators of carotid atherosclerosis. This study aimed to investigate the relationships between hemodynamic parameters in the common carotid artery (CCA) and the severity of carotid atherosclerosis in untreated hypertensive patients. METHODS: Carotid artery ultrasound was performed in 100 untreated hypertensive patients. Morphologic and hemodynamic parameters of the CCA, including peak and mean WSS, global circumferential strain, peak posterior radial strain assessed by two-dimensional speckle tracking method, and IMT, were measured. RESULTS: In patients with hypertension, there were significant correlations between carotid strain parameters and peak/mean WSS. Stepwise multiple regression analysis for carotid strain parameters after adjustment for age, carotid IMT, and brachial pulse wave velocity showed that peak WSS was an independent determinant of peak posterior radial strain (p = 0.009) and global circumferential strain (p = 0.002). CONCLUSIONS: These findings indicate that local shear stress is associated with carotid vascular deformation, which could be an underlying mechanism for the progression of atherosclerosis.

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