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1.
Nutrients ; 15(21)2023 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-37960289

RESUMEN

The aim of this study was to evaluate whether the geriatric nutritional risk index (GNRI) is associated with chronic kidney disease (CKD) progression in patients with type 2 diabetes mellitus (DM). In total, 1100 patients with type 2 DM with a follow-up duration > 1 year were included in this longitudinal study. The risk of CKD progression was assessed according to GNRI quartiles. Patients in the lowest GNRI quartile exhibited a significantly lower estimated glomerular filtration rate (eGFR), compared with those in quartile four. Moreover, these patients had poorer glycemic control and lower hemoglobin levels, body mass index, and albumin levels. Additionally, they exhibited a greater annual decline in eGFR. Multivariate logistic regression analysis showed that old age (>60 years), baseline eGFR, the presence of proteinuria, the use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and low GNRI were significantly associated with CKD progression. GNRI may serve as a valuable predictive tool for identifying the risk of adverse renal outcomes in patients with type 2 DM. It may potentially serve as a more feasible measure for assessing the nutritional status of these patients, as well as for predicting their clinical outcomes.


Asunto(s)
Diabetes Mellitus Tipo 2 , Insuficiencia Renal Crónica , Humanos , Anciano , Persona de Mediana Edad , Diabetes Mellitus Tipo 2/complicaciones , Pronóstico , Estudios Longitudinales , Riñón , Insuficiencia Renal Crónica/diagnóstico , Insuficiencia Renal Crónica/complicaciones , Estado Nutricional , Factores de Riesgo , Tasa de Filtración Glomerular , Progresión de la Enfermedad
3.
Kidney Res Clin Pract ; 41(3): 298-309, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35286796

RESUMEN

BACKGROUND: Hyponatremia overcorrection can result in irreversible neurologic impairment such as osmotic demyelination syndrome. Few prospective studies have identified patients undergoing hypertonic saline treatment with a high risk of hyponatremia overcorrection. METHODS: We conducted a post hoc analysis of a multicenter, prospective randomized controlled study, the SALSA trial, in 178 patients aged above 18 years with symptomatic hyponatremia (mean age, 73.1 years; mean serum sodium level, 118.2 mEq/L). Overcorrection was defined as an increase in serum sodium levels by >12 or 18 mEq/L within 24 or 48 hours, respectively. RESULTS: Among the 178 patients, 37 experienced hyponatremia overcorrection (20.8%), which was independently associated with initial serum sodium level (≤110, 110-115, 115-120, and 120-125 mEq/L with 7, 4, 2, and 0 points, respectively), chronic alcoholism (7 points), severe symptoms of hyponatremia (3 points), and initial potassium level (<3.0 mEq/L, 3 points). The NASK (hypoNatremia, Alcoholism, Severe symptoms, and hypoKalemia) score was derived from four risk factors for hyponatremia overcorrection and was significantly associated with overcorrection (odds ratio, 1.41; 95% confidence interval, 1.24-1.61; p < 0.01) with good discrimination (area under the receiver-operating characteristic [AUROC] curve, 0.76; 95% CI, 0.66-0.85; p < 0.01). The AUROC curve of the NASK score was statistically better compared with those of each risk factor. CONCLUSION: In treating patients with symptomatic hyponatremia, individuals with high hyponatremia overcorrection risks were predictable using a novel risk score summarizing baseline information.

4.
J Vasc Access ; 23(4): 574-580, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33779359

RESUMEN

BACKGROUND: Little is known about the changes in hemodynamic parameters during arteriovenous (AV) access maturation using duplex ultrasound according to radiocephalic fistula (RCF), brachiocephalic fistula (BCF), and AV graft (AVG) in incident hemodialysis (HD) patient. The objective of this study was to evaluate changes and differences in brachial artery flow rate (BAFR) and related parameters affecting maturation by duplex ultrasound in incident HD patients according to access type. METHODS: This study was an observational study conducted from March 2019 to October 2020. During the study period, 109 incident patients underwent new AV access creation, of which 100 were included in the study. The duplex ultrasound was performed on the day prior to access creation, further, day 1, 2 weeks, and 4 weeks later after access creation in incident HD patients. RESULTS: Among all the patients, 38 (38%) received BCF, while 26 (26%) underwent RCF. Of the patients with AVG, 18 (50%) had a forearm loop AVG. The overall mean age was 62.2 ± 13.8 years (range, 32-89). The BAFR increased about 6.9 times in the RCF, 17.4 times in the BCF, and 19.5 times in the AVG at day 1. The median BAFR measured on day 1 was 580.4 mL/min for RC, 1029.0 mL/min for BC, and 1133.0 mL/min for AVG. Relative to the values measured in week 4, the BAFR on day 1 was 69.5% in RCF, 90.6% in BCF, and 93.9% in AVG. The acceleration decreased most significantly on day 1(p < 0.05). The acceleration time increased significantly on day 1 (p < 0.05) and beyond during maturation in the RCF and BCF. The BAFR of the RCF had a significantly negative correlation with the pulsatility index. The BAFR of the BCF showed a significantly positive correlation with the systolic and diastolic blood pressure but negatively correlated with pulse rate. The BAFR of the AVG showed a significant positive correlation with the diameter of the outflow vein. CONCLUSIONS: There were differences in the clinical and duplex parameters during maturation according to access type. The most dramatic changes of duplex parameters were on the day after AV access creation regardless of AV access types. Though RCF had a lower BAFR rate compared to BCF and AVG, it already had a sufficient BAFR required for adequate HD treatment the day after creation. The BAFR of BCF was not different from that of AVG.


Asunto(s)
Derivación Arteriovenosa Quirúrgica , Anciano , Derivación Arteriovenosa Quirúrgica/efectos adversos , Arteria Braquial/cirugía , Antebrazo/irrigación sanguínea , Humanos , Persona de Mediana Edad , Diálisis Renal , Estudios Retrospectivos , Resultado del Tratamiento , Ultrasonografía Doppler Dúplex , Grado de Desobstrucción Vascular
5.
Kidney Res Clin Pract ; 40(4): 724-733, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34510858

RESUMEN

INTRODUCTION: Despite of the routine use of erythropoietin in hemodialysis patients to correct anemia, its administration route's effects on hemoglobin variability and cardiovascular events remain elusive. Herein, we determined different erythropoietin administration routes' effects on hemoglobin variability in hemodialysis patients and the associated factors of hemoglobin variability and cardiovascular events. METHODS: This is a post hoc analysis of a prospective, controlled, randomized, unblinded study with 78 Korean hemodialysis patients receiving intravenous (n = 40) or subcutaneous (n = 38) erythropoietin therapy. We evaluated hemoglobin variability by calculating the frequency of hemoglobin measurements outside the target range during all visits. The high-frequency group was defined by those with hemoglobin variability over the median value (25%) while the low-frequency group was defined by those with hemoglobin variability of <25%. RESULTS: In this analysis, 37 patients (51.1%) were male, and the mean age was 50.6 ± 12.5 years. The frequency of the value being outside the target hemoglobin range was higher in the subcutaneous group compared to the intravenous group (p = 0.03). The low-frequency group required significantly lower erythropoietin doses compared to the high-frequency group. In the adjusted Cox analysis, the parameter high group was a significant independent risk factor for cardiovascular events (p = 0.03). CONCLUSION: The risk out of the target hemoglobin range increased with subcutaneous administration compared with intravenous erythropoietin administration in hemodialysis patients. An increased frequency of the value being outside the target hemoglobin range was also associated with an increased risk of cardiovascular events.

6.
Kidney Res Clin Pract ; 40(3): 371-382, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34233437

RESUMEN

BACKGROUND: Copeptin is secreted in equimolar amounts as arginine vasopressin, main hormone regulating body fluid homeostasis. A recent study reported a copeptin-based classification of osmoregulatory defects in syndromes of inappropriate antidiuresis that may aid in prediction of therapeutic success. We investigated usefulness of copeptin for differentiating etiologies of hyponatremia and predicting efficacy and safety of hypertonic saline treatment in hyponatremic patients. METHODS: We performed a multicenter, prospective cohort study of 100 inpatients with symptomatic hyponatremia (corrected serum sodium [sNa] ≤ 125 mmol/L) treated with hypertonic saline. Copeptin levels were measured at baseline and 24 hours after treatment initiation, and patients were classified as being below or above median of copeptin at baseline or at 24 hours, respectively. Correlations between target, under correction, and overcorrection rates of sNa within 24 hours/24-48 hours and copeptin levels at baseline/24 hours were analyzed. RESULTS: Mean sNa and median copeptin levels were 117.9 and 16.9 pmol/L, respectively. Ratio of copeptin-to-urine sodium allowed for an improved differentiation among some (insufficient effective circulatory volume), but not all hyponatremia etiologic subgroups. Patients with below-median copeptin levels at baseline achieved a higher target correction rate in 6/24 hours (odds ratio [OR], 2.97; p = 0.02/OR, 6.21; p = 0.006). Patients with below-median copeptin levels 24 hours after treatment showed a higher overcorrection rate in next 24 hours (OR, 18.00, p = 0.02). CONCLUSION: There is a limited diagnostic utility of copeptin for differential diagnosis of hyponatremia. However, copeptin might be useful for predicting responses to hypertonic saline treatment in hyponatremic patients.

7.
PLoS One ; 14(5): e0216415, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31048884

RESUMEN

BACKGROUND AND AIMS: Malnutrition and inflammation are closely linked to vascular calcification (VC), the severity of which correlate with adverse outcome. However, there were few studies on the interplay between malnutrition, inflammation and VC progression, rather than VC presence per se. We aimed to determine the relationship of malnutrition, inflammation, abdominal aortic calcification (AAC) progression with survival in hemodialysis (HD) patients. METHODS: Malnutrition and inflammation were defined as low serum albumin (< 40 g/L) and high hs-CRP (≥ 28.57 nmol/L), respectively. We defined AAC progression as an increase in AAC score using lateral lumbar radiography at both baseline and one year later. Patients were followed up to investigate the impact of AAC progression on all-cause and cardiovascular mortality. RESULTS: AAC progressed in 54.6% of 97 patients (mean age 58.2±11.7 years, 41.2% men) at 1-year follow-up. Hypoalbuminemia (Odds ratio 3.296; 95% confidence interval 1.178-9.222), hs-CRP (1.561; 1.038-2.348), low LDL-cholesterol (0.976; 0.955-0.996), and the presence of baseline AAC (10.136; 3.173-32.386) were significant risk factors for AAC progression. During the mean follow-up period of 5.9 years, 38(39.2%) patients died and 27(71.0%) of them died of cardiovascular disease. Multivariate Cox regression analysis adjusted for old age, diabetes, cardiovascular history, and hypoalbuminemia determined that AAC progression was an independent predictor of all-cause mortality (2.294; 1.054-4.994). CONCLUSIONS: Malnutrition and inflammation were significantly associated with AAC progression. AAC progression is more informative than AAC presence at a given time-point as a predictor of all-cause mortality in patients on maintenance HD.


Asunto(s)
Aorta Abdominal/diagnóstico por imagen , Desnutrición , Diálisis Renal , Calcificación Vascular , Adulto , Anciano , Anciano de 80 o más Años , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Femenino , Estudios de Seguimiento , Humanos , Inflamación/diagnóstico por imagen , Inflamación/mortalidad , Inflamación/terapia , Masculino , Desnutrición/complicaciones , Desnutrición/diagnóstico por imagen , Desnutrición/mortalidad , Desnutrición/terapia , Persona de Mediana Edad , Estudios Prospectivos , Tasa de Supervivencia , Calcificación Vascular/diagnóstico por imagen , Calcificación Vascular/etiología , Calcificación Vascular/mortalidad , Calcificación Vascular/terapia
8.
Kidney Res Clin Pract ; 38(2): 205-211, 2019 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-30841691

RESUMEN

BACKGROUND: Elevated serum alkaline phosphatase (AP) and γ-glutamyl transferase (γ-GT) are commonly observed in patients with acute pyelonephritis. The goal of this study was to examine the clinical significance of elevated serum AP and γ-GT levels and to explore the mechanisms underlying these changes. METHODS: We examined serum AP and γ-GT levels in 438 patients with acute pyelonephritis. Urine AP/creatinine (Cr), urine γ-GT/Cr, fractional excretion of AP, and fractional excretion of γ-GT (FEγ-GT) were evaluated in patients with elevated and normal serum levels. AP isoenzymes were also examined. RESULTS: We identified 77 patients (17.6%) with elevated serum AP and 134 patients (30.6%) with elevated serum γ-GT. Among them, both enzymes were elevated in 64 patients (14.6%). Older age, longer hospital stay, elevated baseline serum Cr, and complicated pyelonephritis were associated with increases in serum AP and γ-GT. Multivariate analysis showed that high serum AP levels were significantly correlated with renal impairment (odds ratio, 2.13; 95% confidence interval, 1.08-4.19; P = 0.029). FEγ-GT was significantly lower in patients with elevated serum enzyme levels. The liver fraction for AP isoenzyme profile did not increase in patients with elevated serum AP. CONCLUSION: Our results demonstrated that elevated serum AP and γ-GT levels are associated with complicated pyelonephritis and renal impairment. Lower FEγ-GT levels in patients with elevated serum enzymes may be the result of decreased urinary excretion of these enzymes.

9.
Korean J Intern Med ; 34(6): 1297-1303, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29466851

RESUMEN

BACKGROUND/AIMS: Hepatitis A virus (HAV) is a self-limiting infectious disease, but 1% of subjects develop fulminant hepatitis. The prevalence of the anti-HAV immunoglobulin G (IgG) antibody in hemodialysis subjects in Korea remains unknown. The purpose of this study was to describe and compare the seropositive rate of anti-HAV antibody among hemodialysis subjects in two hospitals according to age group. METHODS: A total of 170 hemodialysis subjects were evaluated for the seropositive rate of the anti-HAV IgG antibody and its titer. RESULTS: Of the 170 maintenance hemodialysis subjects in two hospitals (Kangnam 92 vs. Chuncheon 78), 79 (46.5%) were male. The mean age was 53.2 years old, and 94.1% of the subjects were over 40 years old. The median vintage of hemodialysis was 29.0 months. Anti-HAV antibody was found in 163 subjects (95.9%), with no significant difference between the two areas (Kangnam 97.8% [n = 90] vs. Chuncheon 93.6% [n = 73]). Subjects younger than 40 years old showed a seropositive rate of 50%, while the seropositive rate increased with age for subjects aged 40 or older (p for trend < 0.001). Seropositive subjects from Kangnam showed a higher anti-HAV antibody titer than those from Chuncheon (median: Kangnam 14.2 vs. Chuncheon 11.7). Only age influenced seropositivity. The only factor that influenced the antibody level was the location of hospital (p < 0.001). CONCLUSION: The seropositive rate of the anti-HAV antibody in hemodialysis subjects was 95%, which is similar to findings in the general population. Active immunization against hepatitis A is strongly recommended for hemodialysis subjects under 40 years of age after anti-HAV testing.


Asunto(s)
Anticuerpos de Hepatitis A/sangre , Hepatitis A/sangre , Inmunoglobulina G/sangre , Enfermedades Renales/terapia , Diálisis Renal , Adulto , Factores de Edad , Anciano , Biomarcadores/sangre , Femenino , Hepatitis A/diagnóstico , Hepatitis A/epidemiología , Hepatitis A/virología , Humanos , Enfermedades Renales/sangre , Enfermedades Renales/diagnóstico , Enfermedades Renales/epidemiología , Masculino , Persona de Mediana Edad , Diálisis Renal/efectos adversos , República de Corea/epidemiología , Medición de Riesgo , Estudios Seroepidemiológicos , Resultado del Tratamiento
10.
Korean J Intern Med ; 34(6): 1304-1312, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30025441

RESUMEN

BACKGROUND/AIMS: Maintaining the patency of vascular access (VA) in hemodialysis (HD) patients is important and can be life-saving. We investigated the effects of aspirin resistance and mean platelet volume (MPV) on VA failure in HD patients. METHODS: We enrolled 163 patients on maintenance HD. VA failure was defined as thrombosis or a decrease of > 50% of the normal vessel diameter, as revealed by angiography. RESULTS: Aspirin resistance was observed in 17 of 109 patients in whom this parameter was measured, and was not significantly associated with VA failure (p = 0.051). The mean MPV was 9.15 ± 0.05 fL. The 163 patients were grouped by the median MPV value (9.08 fL) at baseline; patients with higher MPVs (n = 82) had lower platelet counts (p = 0.002) and albumin levels (p = 0.009). During 34 months of follow-up, 65 VA failures (39.9%) occurred. The Kaplan-Meier curve revealed significant differences between the two groups in terms of cumulative VA failure (54.1% vs. 35.3%, p = 0.018). On multivariate analysis, the MPV (hazard ratio [HR], 1.794; 95% confidence interval [CI], 1.066 to 3.020; p = 0.028), platelet count (HR, 1.003; 95% CI, 1.001 to 1.006; p = 0.01), and smoking status (HR, 1.894; 95% CI, 1.019 to 3.519; p = 0.043) independently predicted VA failure. CONCLUSION: A high MPV was associated with an increased risk of VA failure, whereas aspirin resistance showed only a weak association. The MPV may predict VA survival in HD patients.


Asunto(s)
Derivación Arteriovenosa Quirúrgica/efectos adversos , Aspirina/uso terapéutico , Implantación de Prótesis Vascular/efectos adversos , Resistencia a Medicamentos , Oclusión de Injerto Vascular/etiología , Fallo Renal Crónico/terapia , Volúmen Plaquetario Medio , Inhibidores de Agregación Plaquetaria/uso terapéutico , Agregación Plaquetaria/efectos de los fármacos , Diálisis Renal , Grado de Desobstrucción Vascular , Anciano , Aspirina/efectos adversos , Femenino , Oclusión de Injerto Vascular/sangre , Oclusión de Injerto Vascular/diagnóstico , Oclusión de Injerto Vascular/fisiopatología , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/diagnóstico , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria/efectos adversos , Valor Predictivo de las Pruebas , Medición de Riesgo , Factores de Riesgo , Insuficiencia del Tratamiento
11.
PLoS One ; 12(1): e0170272, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28099511

RESUMEN

BACKGROUND: In hemodialysis patients, fluid overload and malnutrition are accompanied by extracellular fluid (ECF) expansion and intracellular fluid (ICF) depletion, respectively. We investigated the relationship between ECF/ICF ratio (as an integrated marker reflecting both fluid overload and malnutrition) and survival and cardiovascular disease (CVD) in the context of malnutrition-inflammation-arteriosclerosis (MIA) complex. METHODS: Seventy-seven patients from a single hemodialysis unit were prospectively enrolled. The ECF/ICF volume was measured by segmental multi-frequency bioimpedance analysis. MIA and volume status were measured by serum albumin, C-reactive protein (CRP), pulse wave velocity (PWV) and plasma B-type natriuretic peptide (BNP), respectively. RESULTS: The mean ECF/ICF ratio was 0.56±0.06 and the cut-off value for maximum discrimination of survival was 0.57. Compared with the low ECF/ICF group, the high ECF/ICF group (ratio≥0.57, 42%) had higher all-cause mortality, CVD, CRP, PWV, and BNP, but lower serum albumin. During the 5-year follow-up, 24 all-cause mortality and 38 CVD occurred (18 and 24, respectively, in the high ECF/ICF group versus 6 and 14 respectively in the low ECF/ICF group, P<0.001). In the adjusted Cox analysis, the ECF/ICF ratio nullifies the effects of the MIA and volume status on survival and CVD and was an independent predictor of all-cause mortality and CVD: hazard ratio (95% confidence interval); 1.12 (1.01-1.25) and 1.09 (1.01-1.18) for a 0.01 increase in the ECF/ICF ratio. The degree of malnutrition (albumin), inflammation (CRP), arteriosclerosis (PWV), and fluid overload (BNP) were correlated well with the ECF/ICF ratio. CONCLUSIONS: Hemodialysis patients with high ECF/ICF ratio are not only fluid overloaded, but malnourished and have stiff artery with more inflammation. The ECF/ICF ratio is highly related to the MIA complex, and is a major risk indicator for all-cause mortality and CVD.


Asunto(s)
Arteriosclerosis/patología , Líquido Extracelular/metabolismo , Inflamación/patología , Líquido Intracelular/metabolismo , Desnutrición/patología , Diálisis Renal/mortalidad , Proteína C-Reactiva/análisis , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Péptido Natriurético Encefálico/sangre , Estudios Prospectivos , Análisis de la Onda del Pulso , Factores de Riesgo , Albúmina Sérica/análisis
12.
Electrolyte Blood Press ; 15(2): 42-46, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29399023

RESUMEN

Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the most common cause of euvolemic hypo-osmotic hyponatremia. There are several etiologies of SIADH including neuroendocrine tumor, pulmonary disease, infection, trauma, and medications. Here, we report a case of SIADH associated with a schwannoma involving the mediastinum in a 75-year-old woman who presented with nausea, vomiting, and general weakness. Laboratory testing showed hypo-osmolar hyponatremia, with a serum sodium level of 102mmol/L, serum osmolality of 221mOsm/kg, urine osmolality of 382mOsm/kg, urine sodium of 55 mmol/L, and plasma antidiuretic hormone (ADH) of 4.40 pg/mL. Chest computed tomography identified a 1.5-cm-sized solid enhancing nodule in the right lower paratracheal area. A biopsy specimen was obtained by video-assisted thoracoscopic surgery, which was diagnosed on pathology as a schwannoma. The hyponatremia was completely resolved after schwannoma resection and plasma ADH level decreased from 4.40 pg/mL to 0.86 pg/mL. This case highlights the importance of suspecting and identifying the underlying cause of SIADH when faced with refractory or recurrent hyponatremia, and that on possibility is mediastinal schwannoma.

13.
J Korean Med Sci ; 31(10): 1516-28, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27550478

RESUMEN

Atypical hemolytic uremic syndrome (aHUS) is a rare syndrome characterized by micro-angiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury. The major pathogenesis of aHUS involves dysregulation of the complement system. Eculizumab, which blocks complement C5 activation, has recently been proven as an effective agent. Delayed diagnosis and treatment of aHUS can cause death or end-stage renal disease. Therefore, a diagnosis that differentiates aHUS from other forms of thrombotic microangiopathy is very important for appropriate management. These guidelines aim to offer recommendations for the diagnosis and treatment of patients with aHUS in Korea. The guidelines have largely been adopted from the current guidelines due to the lack of evidence concerning the Korean population.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Síndrome Hemolítico Urémico Atípico/diagnóstico , Transfusión Sanguínea , Trasplante de Órganos , Proteína ADAMTS13/genética , Proteína ADAMTS13/metabolismo , Lesión Renal Aguda/etiología , Síndrome Hemolítico Urémico Atípico/epidemiología , Síndrome Hemolítico Urémico Atípico/terapia , Factor H de Complemento/genética , Proteínas del Sistema Complemento/genética , Proteínas del Sistema Complemento/metabolismo , Diagnóstico Tardío , Humanos , Fallo Renal Crónico/etiología , República de Corea/epidemiología
14.
J Nanosci Nanotechnol ; 15(3): 2404-8, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26413676

RESUMEN

In this paper, we demonstrated thin film semitransparent anode electrode using Ni/Ag/Ni (3/6/3 nm) on green and red phosphorescent OLEDs, which have basically high efficiency and good optical characteristics. Moreover, we applied this semitransparent anode on flexible green and red phosphorescent OLEDs, which were then optimized for possible applications on flexible substrates. First, we studied optimization using various conditions of Ni/Ag/Ni electrodes via transmittance and sheet resistance. We then fabricated the devices on a glass substrate with ITO or Ni/Ag/Ni electrodes as well as on a flexible substrate with a Ni/Ag/Ni electrode for green and red phosphorescent OLEDs. Consequently, we could be proposed that the potential of our semitransparent anode electrode is demonstrated. Green phosphorescent OLEDs characteristics using ITO or Ni/Ag/Ni anode electrodes were coincided and those of the red phosphorescent OLEDs were improved by semitransparent electrodes at 10,000 cd/m2 criterion. Therefore, this research suggests for additional studies to be conducted on flexible and high-performance phosphorescent OLED displays and light applications for ITO-free processes.

15.
J Nanosci Nanotechnol ; 15(2): 1456-9, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26353672

RESUMEN

We investigated a light emission mechanism of blue phosphorescent organic light emitting diodes (PHOLEDs), using a stepwise doping profile of 2, 8, and 14 wt.% within the emitting layer (EML). We fabricated several blue PHOLEDs with phosphorescent blue emitter iridium(III) bis[(4,6-difluorophenyl)-pyridinato-N,C2]picolinate doped in N,N'-dicarbazolyl-3,5-benzene as a p-type host material. A blue PHOLED with the highest doping concentration as part of the EML close to an electron transporting layer showed a maximum luminous efficiency of 20.74 cd/A, and a maximum external quantum efficiency of 10.52%. This can be explained by effective electron injection through a highly doped EML side. Additionally, a white OLED based on the doping profile was fabricated with two thin red EMLs within a blue EML maintaining a thickness of 30 nm for the entire EML. Keywords: Blue Phosphorescent Organic Light Emitting Diodes, Stepwise Doping Structure, Charge Trapping Effect.


Asunto(s)
Color , Iluminación/instrumentación , Nanocompuestos/química , Compuestos Orgánicos/química , Semiconductores , Transferencia de Energía , Diseño de Equipo , Análisis de Falla de Equipo , Ensayo de Materiales , Nanocompuestos/ultraestructura
16.
Diabetes Res Clin Pract ; 109(1): 164-9, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25979274

RESUMEN

Diabetic bladder dysfunction (DBD) is a common complication of type 2 diabetes mellitus (T2DM). The association between DBD and progression of diabetic nephropathy has not been clarified. In this study, we investigated the relationship between post-voiding residual urine (PVR) with decline in renal function in patients with type 2 diabetes. This retrospective study included 164 patients at a single center. We collected medical histories and laboratory findings of patients undergoing uroflowmetry from January 1, 2008 to October 30, 2013. Renal function was assessed by calculating the estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease (MDRD) study equation. We evaluated whether greater PVR was a risk factor for faster decline of GFR during a 1-year follow-up. The subjects' mean age was 65±12 years, duration of diabetes 12.8±8.8 years, baseline serum creatinine level 106.1±53.0 µmol/L, and eGFR was 64.6±25.2 mL/min/1.73 m(2). Mean PVR was 69.8±96.3 mL and in 17.7% of subjects, PVR>100 mL. In linear regression analysis, PVR was independently associated with GFR decrease (standardized ß coefficient=0.2, P=0.009). Multiple logistic analysis showed that subjects with PVR>100 mL had a 2.8-fold higher risk of an eGFR change during 1 year higher than the median value of all subjects (95% confidence interval, 1.1-6.8; P=0.03). Increased PVR was independently associated with a more rapid decline in renal function in patients with type 2 diabetes.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/orina , Nefropatías Diabéticas/orina , Riñón/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/fisiopatología , Nefropatías Diabéticas/fisiopatología , Progresión de la Enfermedad , Femenino , Tasa de Filtración Glomerular , Humanos , Masculino , Persona de Mediana Edad , Análisis de Regresión , Estudios Retrospectivos , Factores de Riesgo , Toma de Muestras de Orina , Adulto Joven
17.
Korean J Intern Med ; 30(1): 82-7, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25589839

RESUMEN

BACKGROUND/AIMS: Diabetic cystopathy is a frequent complication of diabetes mellitus. This study assessed the association between the post-voiding residual (PVR) urine volume and diabetic nephropathy in type 2 diabetics with no voiding symptoms. METHODS: This study investigated 42 patients with type 2 diabetes who were followed regularly at our outpatient clinic between July 1, 2008 and June 30, 2009. No patient had voiding problems or International Prostate Symptom Scores (IPSSs) ≥ 12. An urologist performed the urological evaluations and the PVR was measured using a bladder scan. A PVR > 50 mL on two consecutive voids was considered abnormal, which was the primary study outcome. RESULTS: The mean patient age was 60 ± 10 years; the IPSS score was 3.7 ± 3.3; and the diabetes duration was 11.9 ± 7.8 years. Seven of the 42 patients (16.7%) had a PVR > 50 mL. The presence of overt proteinuria or microalbuminuria was associated with an increased risk of a PVR > 50 mL (p < 0.01). Patients with a PVR > 50 mL had a significantly lower estimated glomerular filtration rate (eGFR) compared with those with a PVR ≤ 50 mL (59.2 ± 27.1 mL/min/1.73 m(2) vs. 28.7 ± 23.3 mL/min/1.73 m(2); p < 0.001). Multivariate logistic analysis revealed that a lower eGFR (odds ratio, 0.94; 95% confidence interval, 0.88 to 0.99; p = 0.04) was a significant risk factor for a PVR > 50 mL. CONCLUSIONS: Patients with diabetic nephropathy had a significantly higher PVR and a lower eGFR was associated with an abnormal PVR.


Asunto(s)
Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/etiología , Tasa de Filtración Glomerular , Riñón/fisiopatología , Urodinámica , Adulto , Anciano , Anciano de 80 o más Años , Diabetes Mellitus Tipo 2/diagnóstico , Nefropatías Diabéticas/diagnóstico , Nefropatías Diabéticas/fisiopatología , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Servicio Ambulatorio en Hospital , República de Corea , Factores de Riesgo , Factores de Tiempo
18.
Int J Cardiol ; 176(3): 941-5, 2014 Oct 20.
Artículo en Inglés | MEDLINE | ID: mdl-25200848

RESUMEN

BACKGROUND: Periprocedural (6 h pre- and 24 h post-angiography) hemofiltration appears to effectively prevent contrast-induced nephropathy (CIN) in chronic kidney disease (CKD) patients undergoing coronary angiography. However, this procedure over-uses medical resources, and the cessation of hemofiltration during coronary angiography results in persistent renal injury. In comparison, simultaneous hemofiltration performed only during coronary angiography requires fewer medical resources and can provide instantaneous protection against CIN. METHODS: Sixty-eight CKD patients (serum creatinine, 2.51±1.15 mg/dL) undergoing coronary angiography were randomized in a 1:2 ratio to receive either periprocedural (n=23) or simultaneous (n=45) hemofiltration. The expected CIN rate was similar for the two groups (41.3% versus 40.0%, p=0.769). RESULTS: On day 3 after contrast exposure, four and seven patients in the periprocedural and simultaneous groups, respectively experienced CIN (17.4% versus 15.6%, p=0.846). On days 5-30, seven and three patients in the periprocedural and simultaneous groups, respectively experienced CIN (30.4% versus 6.7%, p=0.009). The serum creatinine levels of patients in the periprocedural group transiently decreased on day 1 and persistently increased during days 5-30 compared with the simultaneous group. This difference between the two groups in terms of creatinine levels over time was statistically significant (F statistic=6.830; p=0.001, by ANCOVA). The cost of hemofiltration was doubled in the periprocedural group ($1066±83 versus $504±40, p<0.001). CONCLUSIONS: Simultaneous hemofiltration provide equal early (day 3) and better late-stage (days 5-30) renal protection against CIN at a significantly lower cost compared with periprocedural hemofiltration.


Asunto(s)
Lesión Renal Aguda/inducido químicamente , Lesión Renal Aguda/prevención & control , Medios de Contraste/efectos adversos , Angiografía Coronaria/efectos adversos , Hemofiltración/métodos , Insuficiencia Renal Crónica/diagnóstico por imagen , Lesión Renal Aguda/epidemiología , Anciano , Angiografía Coronaria/métodos , Creatinina/sangre , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Atención Perioperativa/métodos , Proyectos Piloto , Estudios Prospectivos , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/complicaciones , Ácidos Triyodobenzoicos/efectos adversos
19.
J Nanosci Nanotechnol ; 14(10): 7835-8, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25942876

RESUMEN

The authors describe the fabrication of white organic light-emitting diodes (WOLEDs) with dual electron transporting layers (D-ETL) using 2,9-dimethyl-4,7-diphenyl-1,10-phenanhroline/ 4,7-diphenyl-1,10-phenanthroline (BPhen) and bis-(2-methyl-8-quinolinolate)-4-(phenylphenolato) aluminum/BPhen. Stepwise D-ETL easily transports electrons easily to the emitting layer and reduces the leakage of electrons. Therefore, WOLEDs with D-ETL show higher external quantum efficiency (EQE) when compared to a control WOLED with a single ETL device. The optimized WOLEDs showed a peak EQE of 13.0%, luminous efficiency of 27.4 cd/A, and Commission Internationale de L'Eclairage coordinates of (0.40, 0.39) at 1000 cd/m2.

20.
J Nanosci Nanotechnol ; 14(11): 8315-9, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25958520

RESUMEN

We suggested that Ni/Ag/Ni semitransparent electrodes for the exchange of indium-tin-oxide (ITO) electrode, which is the most commonly used as a transparent electrode in spite of the structural defects, limited supply of indium, and toxic, could be apply on flexible Organic Light-Emitting Diodes (OLEDs). Red phosphorescent OLEDs (PHOLEDs) using different types of electrodes as ITO and various conditions of Ni/Ag/Ni electrode were fabricated and analyzed. The electrical and optical properties of device using Ni/Ag/Ni electrode were improved than that of devices on ITO glass substrate at the 10,000 cd/m2 criterion due to the micro-cavity effect even though their transmittance has lower than ITO glass. In addition, we also fabricated red PHOLEDs of same structure on Ni/Ag/Ni flexible substrate of various conditions. As a result, flexible red PHOLED showed competitive characteristics compared to the device on a glass substrate. Therefore, this study could be suggested to additional research on flexible OLEDs display and light applications for ITO-free fabrication.

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