Polyelemental Nanoparticles as Catalysts for a Li-O2 Battery.

The development of highly efficient catalysts in the cathodes of rechargeable Li-O2 batteries is a considerable challenge. Polyelemental catalysts consisting of two or more kinds of hybridized catalysts are particularly interesting because the combination of the electrochemical properties of each catalyst component can significantly facilitate oxygen evolution and oxygen reduction reactions. Despite the recent advances that have been made in this field, the number of elements in the catalysts has been largely limited to two metals. In this study, we demonstrate the electrochemical behavior of Li-O2 batteries containing a wide range of catalytic element combinations. Fourteen different combinations with single, binary, ternary, and quaternary combinations of Pt, Pd, Au, and Ru were prepared on carbon nanofibers (CNFs) via a joule heating route. Importantly, the Li-O2 battery performance could be significantly improved when using a polyelemental catalyst with four elements. The cathode containing quaternary nanoparticles (Pt-Pd-Au-Ru) exhibited a reduced overpotential (0.45 V) and a high discharge capacity based on total cathode weight at 9130 mAh g-1, which was ∼3 times higher than that of the pristine CNF electrode. This superior electrochemical performance is be attributed to an increased catalytic activity associated with an enhanced O2 adsorbability by the quaternary nanoparticles.

Understanding Reaction Pathways in High Dielectric Electrolytes Using ß-Mo2C as a Catalyst for Li-CO2 Batteries.

The rechargeable Li-CO2 battery has attracted considerable attention in recent years because of its carbon dioxide (CO2) utilization and because it represents a practical Li-air battery. As with other battery systems such as the Li-ion, Li-O2, and Li-S battery systems, understanding the reaction pathway is the first step to achieving high battery performance because the performance is strongly affected by reaction intermediates. Despite intensive efforts in this area, the effect of material parameters (e.g., the electrolyte, the cathode, and the catalyst) on the reaction pathway in Li-CO2 batteries is not yet fully understood. Here, we show for the first time that the discharge reaction pathway of a Li-CO2 battery composed of graphene nanoplatelets/beta phase of molybdenum carbide (GNPs/ß-Mo2C) is strongly influenced by the dielectric constant of its electrolyte. Calculations using the continuum solvents model show that the energy of adsorption of oxalate (C2O42-) onto Mo2C under the low-dielectric electrolyte tetraethylene glycol dimethyl ether is lower than that under the high-dielectric electrolyte N,N-dimethylacetamide (DMA), indicating that the electrolyte plays a critical role in determining the reaction pathway. The experimental results show that under the high-dielectric DMA electrolyte, the formation of lithium carbonate (Li2CO3) as a discharge product is favorable because of the instability of the oxalate species, confirming that the dielectric properties of the electrolyte play an important role in the formation of the discharge product. The resulting Li-CO2 battery exhibits improved battery performance, including a reduced overpotential and a remarkable discharge capacity as high as 14,000 mA h g-1 because of its lower internal resistance. We believe that this work provides insights for the design of Li-CO2 batteries with enhanced performance for practical Li-air battery applications.

Does Exposure to Computed Tomography Contrast Media Increase Risk of End-Stage Renal Disease?

BACKGROUND There are many studies on acute kidney injury (AKI) after exposure to contrast media in patients with chronic kidney disease (CKD). However, whether the risk of end-stage renal disease (ESRD) increases after exposure to contrast media in the long term, regardless of development of AKI after such exposure, has not been studied. MATERIAL AND METHODS The electronic health records of patients diagnosed with CKD and followed up from 2014 to 2018 at a tertiary university hospital were retrospectively collected. Patients were divided into patients who progressed to ESRD (ESRD group) and those who did not (non-ESRD group). Patients in the non-ESRD group were matched 1: 1 to those in the ESRD group by using disease risk score generation and matching. Multivariate logistic regression analysis was performed to assess the effect of contrast media exposure on progression to ESRD. RESULTS In total, 179 patients were enrolled per group; 178 (99.4%) were in CKD stage 3 or above in both groups. Average serum creatinine was 4.31±3.02 mg/dl and 3.64±2.55 mg/dl in the ESRD and non-ESRD groups, respectively (p=0.242). Other baseline characteristics were not statistically significant, except for the number of times contrast-enhanced computed tomography (CECT) was performed (0.00 [Interquartile range (IQR) 0.00-2.00] in the ESRD group and 0.00 [IQR 0.00-1.00] in the non-ESRD group [p=0.006]); in multivariate logistic regression, this number (OR=1.24, 95% CI=1.08-1.47, p=0.006) was significantly related to progression to ESRD. CONCLUSIONS The use of CECT increased the risk of ESRD 1.2-fold in advanced and stable CKD outpatients after 5-year follow-up.

Optimal cut-off value of high-sensitivity troponin I in diagnosing myocardial infarction in patients with end-stage renal disease.

End-stage renal disease (ESRD) is a major risk factor for cardiovascular disease and the prognosis after myocardial infarction (MI) is dismal. Although cardiac troponin is a key diagnostic test, troponin levels are often elevated in ESRD patients without evidence of MI. Thus, this study attempted to determine the optimal diagnostic value of high-sensitivity troponin I (hsTnI) by dialysis modality in ESRD patients.Medical records of adult dialysis patients who visited tertiary emergency department (ED) were collected retrospectively. Diagnosis of MI was made according to the fourth universal definition of MI. The cut-off values were calculated using a receiver operating characteristic (ROC) curve.Medical records of 1144 patients were analyzed and MI was diagnosed in 82 patients (75 on hemodialysis and 7 on peritoneal dialysis). The optimal cut-off value of hsTnI in hemodialysis patients was 75 ng/L, with 93.33% sensitivity and 60.76% specificity. Area under the curve (AUC) was .870 (95% confidence interval (CI) .833-.906). The optimal cut-off value of hsTnI in peritoneal dialysis patients was 144 ng/L, with 100.00% sensitivity and 83.10% specificity. AUC was .943 (95% CI .893-.992).The dialysis modality should also be considered when diagnosing MI using hsTnI in ESRD patients.

Congenital adrenal hyperplasia presenting as pelvic inflammatory disease in a phenotypic male: A case report.

RATIONALE: Congenital adrenal hyperplasia (CAH) is caused by various enzyme deficiencies, among which 21-hydroxylase (21-OH) deficiency accounts for more than 90% of cases. Neonatal screening became mandatory only a few decades ago. Many patients who were born before this went undiagnosed and some of the severely virilized females were raised as men. PATIENT CONCERNS: A 58-year old man with a history of excisional surgery in the external genitalia when he was a toddler presented with three days of dysuria and low abdominal pain. DIAGNOSIS: The patient's laboratory results showed leukocytosis and elevated C-reactive protein (CRP); thus, the physicians decided to perform a computed tomography (CT) scan. The CT demonstrated pelvic inflammatory disease (PID), left adrenal gland myelolipoma, and a mesenteric mass. Meanwhile, we suspected CAH based on the clinical history and assessed the patient's hormone levels. Seventeen-hydroxyprogesterone (17-OH-PG) was markedly elevated and the patient was diagnosed with classic simple virilizing CAH. INTERVENTIONS: Intravenous antibiotics were administered, and positron emission tomography-CT (PET-CT) was performed to evaluate any metastases. OUTCOMES: After 2 weeks of antibiotic treatment, CRP decreased to 0.12 mg/dL and PID was resolved. The patient opted for resection of the female genitalia along with the mesenteric and adrenal gland tumors in the near future, and was safely discharged. LESSONS: The adrenal gland myelolipoma was thought to have developed as a result of a longstanding exposure to adrenocorticotropic hormone. There are controversies regarding the management of female genitalia in CAH patients who identify themselves as men. In this case, the physician and patient decided to remove the female genitalia because the surgery for the mesenteric mass was inevitable and there was a possibility of recurrent PID. To our knowledge, this is the first article to report primary mesenteric tumor in a CAH patient to date. In conclusion, patients who were born before neonatal screening for CAH became the mainstay, who are suspected to have CAH from their history, and present with abdominal pain must be diagnosed by performing an imaging study, testing levels of serum 17-OH-PG, and screening for female genitalia and adrenal gland myelolipoma.

Effects of education on low-phosphate diet and phosphate binder intake to control serum phosphate among maintenance hemodialysis patients: A randomized controlled trial.

BACKGROUND: For phosphate control, patient education is essential due to the limited clearance of phosphate by dialysis. However, well-designed randomized controlled trials about dietary and phosphate binder education have been scarce. METHODS: We enrolled maintenance hemodialysis patients and randomized them into an education group (n = 48) or a control group (n = 22). We assessed the patients' drug compliance and their knowledge about the phosphate binder using a questionnaire. RESULTS: The primary goal was to increase the number of patients who reached a calcium-phosphorus product of lower than 55. In the education group, 36 (75.0%) patients achieved the primary goal, as compared with 16 (72.7%) in the control group (P = 0.430). The education increased the proportion of patients who properly took the phosphate binder (22.9% vs. 3.5%, P = 0.087), but not to statistical significance. Education did not affect the amount of dietary phosphate intake per body weight (education vs. control: -1.18 ± 3.54 vs. -0.88 ± 2.04 mg/kg, P = 0.851). However, the dietary phosphate-to-protein ratio tended to be lower in the education group (-0.64 ± 2.04 vs. 0.65 ± 3.55, P = 0.193). The education on phosphate restriction affected neither the Patient-Generated Subjective Global Assessment score (0.17 ± 4.58 vs. -0.86 ± 3.86, P = 0.363) nor the level of dietary protein intake (-0.03 ± 0.33 vs. -0.09 ± 0.18, P = 0.569). CONCLUSION: Education did not affect the calcium-phosphate product. Education on the proper timing of phosphate binder intake and the dietary phosphate-to-protein ratio showed marginal efficacy.

Disease-specific impairment of the quality of life in adult patients with chronic spontaneous urticaria.

BACKGROUND/AIMS: Chronic urticaria (CU) is a common skin disorder characterized by wheals and pruritus lasting more than 6 weeks. Due to its long duration and changeable symptoms, the quality of life (QOL) of patients with CU can be impaired substantially. We evaluated the CU-QOL, a previously validated CU-specific QOL measure, and investigated factors influencing QOL in chronic spontaneous urticaria (CSU) patients. METHODS: A hospital-based cross-sectional study was performed on 390 adult patients diagnosed with CSU from March 2009 to December 2012 at the Allergy and Clinical Immunology Clinic at Ajou University Hospital. The CU-QOL questionnaire, urticaria activity score (UAS), combined angioedema, and serum total immunoglobulin E (IgE) levels were investigated. RESULTS: The average CU-QOL score obtained from the questionnaire was 70.6 (of 100 points). The CU-QOL scores correlated significantly with the UAS, particularly with the 15-point UAS (UAS-15; coefficient -0.532, p < 0.01) rather than the 6-point UAS (-0.502, p < 0.01). The patients presenting with angioedema and urticaria had poorer scores in the urticaria symptom domain than those with urticaria alone (37.4 vs. 46.9, p = 0.004). Log-transformed serum total IgE levels correlated significantly with CU-QOL (-0.131, p < 0.05). Multivariate regression models indicated that severe CU (UAS-15 score ≥ 13), log (total IgE), and the presence of angioedema were significant predictors of impaired CU-QOL (< 85 points). CONCLUSIONS: CU has a substantial negative impact on QOL. The assessment of UAS-15, total IgE, and the presence of angioedema can be useful to predict QOL of the patients with CSU.

Clinical analysis of single filtration plasmapheresis using continuous renal replacement therapy machines in kidney transplantation.

BACKGROUND: Plasmapheresis has become an essential element of kidney transplantation (KT). In the present study, we report clinical outcomes of filtration plasmapheresis using continuous renal replacement therapy machines with a single filter for the first time in Korea. METHODS: We retrospectively analyzed six patients who underwent filtration plasmapheresis for KT in our center; plasmapheresis was performed using the Plasmaflex (Baxter®) with a TPE 2000 filter set (Baxter®) in our hemodialysis unit. Five percent albumin was used as the replacement fluid, and intravenous immunoglobulin G was administered after each plasmapheresis session. The target preoperative ABO isoagglutinin titer was less than 1:8. RESULTS: Filtration plasmapheresis was performed in four patients for ABO-incompatible KT, one for antibody-mediated rejection after KT, and the last one for positive T cell crossmatch. Altogether, 46 sessions of plasmapheresis were performed. ABO isoagglutinin titers successfully declined to or below the target level in all patients, and all patients successfully received KT with no significant antibody titer rebound. Acute antibody-mediated rejection and positive T cell crossmatch were well treated with filtration plasmapheresis, and no patient required fresh frozen plasma infusion for coagulopathy. There were one episode of hypotension and three of hypocalcemia. No patients experienced bleeding, infection, or allergic reaction. CONCLUSION: Filtration plasmapheresis was effective and safe. Although our result is from a single center, our protocol appears to be promising.

Enrichment of phosphopeptides using bare magnetic particles.

Magnetic iron(II, III) oxide (magnetite, Fe(3)O(4)) nanoparticles were used to selectively enrich phosphopeptides from tryptic digests of bovine beta-casein and from tryptic digest mixtures containing bovine beta-casein, cytochrome c, bovine serum albumin, and horse heart myoglobin. The magnetic property of the particles permits an easy and speedy enrichment process. No enrichment of phosphopeptides was observed from ferric magnetic iron(III) oxide (Fe(2)O(3)) nanoparticles. These data collectively demonstrate that the enrichment of phosphopeptides using magnetic iron(II, III) oxide nanoparticles is a practical method for the selective analysis of phosphopeptides and could be helpful in isolating and analyzing phosphorylated peptides from complex biological samples.