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Background Peripherally inserted central catheter (PICC) use among critically ill patients with or without acute kidney injury (AKI) has gradually increased. Ultrasound-guided bedside PICC insertion in intensive care units (ICU) has been reported to be safe and effective. Reports of PICC insertion by a nephrologist without fluoroscopy, however, are relatively rare. Methods This retrospective study included patients (n = 224) who had a PICC inserted by a single nephrologist at Samsung Changwon Hospital from January 2019 to June 2020. Group 1 patients (n = 98) had PICCs inserted under ultrasound guidance, while group 2 patients (n = 126) had PICCs inserted under fluoroscopic guidance. Success rates, multiple puncture rates, and malposition rates were compared between the two groups. Results Underlying comorbidities (sepsis, AKI, ventilator use, and shock) were more common in group 1 than in group 2. Success rates were comparable between the two groups (93.9% vs. 97.6%, p = 0.171). Multiple puncture rate among successful cases (4.1% vs. 0.0%, p = 0.035) was higher in group 1 than group 2. Excluding central vein occlusion cases, malposition occurred only one in group 1. Conclusion Bedside PICC insertion by a nephrologist is easy and safe to perform in comorbid patients who are difficult to move to the angiography room. The success rate of ultrasound-guided PICC insertions was comparable to that of PICC insertion performed under fluoroscopic guidance. In the life-threatening ICU setting, PICCs can be successfully placed by the interventional nephrologists.

Abstract The association between alcohol consumption and kidney function is intriguing, but study results are mixed and controversial. We examined the association of alcohol consumption with the overall change in kidney function over 12 years. We analyzed data from a population-based cohort that was part of the Korean Genome and Epidemiology Study. Primary exposure was total alcohol intake (non-drinkers, 0 to

Abstract Background A loss of muscle mass may be influenced by multiple factors. Insulin sensitivity and metabolic acidosis are associated with muscle wasting and may be improved with potassium intake. This study evaluated the association between dietary potassium intake and skeletal muscle mass. Methods We performed a cross-sectional study with data obtained from the Korean National Health and Nutrition Examination Survey (KNHANES) (2008–2011). Participant’s daily food intake was assessed using a 24-h recall method. Appendicular skeletal muscle mass (ASM) was calculated as the sum of muscle mass in both arms and legs, measured using dual energy X-ray absorptiometry. The skeletal muscle index (SMI) was calculated as ASM divided by height2 (kg/m2). Low muscle mass was defined as a SMI

This paper examines the actions and the factors driving those actions to reduce energy consumption and enhance energy efficiency taken by United States cities. While not much empirical evidence is available on why governments pursue practical sustainability actions, we attempt to shed more light on this important topic by empirically identifying factors that contribute to concrete actions toward sustainability policies. We adopt political market theory as a basic theoretical framework with policy-making applied to city energy consumption. Using the 2010 ICMA (local government sustainability policies and program) data, this study expands the focus of analyses to evaluate the effect of the form of government on energy consumption and energy efficiency by using multiple regression analysis. The findings show that at the city level, the mayor- council form of government are negatively associated with governments’ efforts to reduce energy consumption. However, cities with at-large elections and municipal ownership are more likely to adopt sustainability actions. We also find that a large-scale economy has significant effects on the effort to reduce city energy consumption and improve energy efficiency. This shows that environmental policies are directly connected to locally relevant affairs, including housing, energy use, green transportation, and water. Thus, local level administrators could take an executive role to protect the environment, encourage the development of alternative energy, and reduce the use of fossil fuel and coal energy. These efforts can lead to important environmental ramifications and relevant actions by municipal governments.

Background/Aims The strategy of access care at out center involves the use of ultrasound (USG) in case of physical examination (PE) abnormality. USG determines the need of angiography. This study investigated the possible association between the need for percutaneous transluminal angioplasty (PTA) and hemodynamic parameters of USG. The study also assessed the effects of this monitoring strategy on outcomes in comparison with a historical control. Methods A retrospective study of the medical records of 127 patients (65 PTA, 62 non-PTA) was conducted. Data were analyzed using logistic regression analysis and receiver operating characteristic curve. Fistula outcomes and intervention rates were calculated and compared with 100 historic controls. Results Logistic regression analysis showed that brachial artery flow volume (FV) < 612.9 mL/min or brachial artery resistance index (RI) > 0.63 was independently associated with the need for PTA. This monitoring strategy showed an a reduction in thromboses (0.02 ± 0.11 events/arteriovenous fistula [AVF]-year vs. 0.07 ± 0.23 events/AVF-year, p = 0.046), reduction in central venous catheter placement (0.01 ± 0.05 events/AVF-year vs. 0.06 ± 0.22 events/AVF-year, p = 0.010), reduction in access loss (0.02 ± 0.13 events/AVF-year vs. 0.19 ± 0.34 events/AVF-year, p = 0.015), and increase in access selective repair (0.49 ± 0.66 events/AVF-year vs. 0.21 ± 0.69 events/AVF-year, p = 0.003), compared to historic control. Conclusions There was significant stenosis if brachial artery FV was < 612.9 mL/min or RI was > 0.63 for PE abnormality. These parameters should be used as markers for assessing PTA risk in hemodialysis patients. Addition of USG to determine the need of angiography after detection of PE abnormality leads to decreases in access thrombosis, catheter placement, and access loss despite increasing access intervention rates compared to clinical monitoring.

Background: Salvage of a thrombosed arteriovenous fistula (AVF) by secondary fistula conversion may be more effective than a conventional endovascular procedure for forearm fistula thrombosis. Surgical access procedures are an undeveloped area in interventional nephrology compared to endovascular procedures. Herein, the author report the results of surgical salvage of thrombosed AVFs by interventional nephrologists. Methods: The author retrospectively analyzed 52 surgical salvage procedures for AVF thrombosis (radiocephalic fistula = 44 cases, brachiocephalic fistula = 8 cases) that were performed by interventional nephrologist between March 2007 and January 2016. Results: Secondary fistula formation using the proximal vein was performed for 46 cases (88.5%); outflow rerouting was performed for two cephalic-arch stenosis cases (3.9%), simple thrombectomy was performed for two cases (3.9%), and a graft interposition was performed for two cases (3.9%). Technical success after the surgical procedures was achieved in 51 cases (98.1%), and 39 AVFs (75.0%) were prepared for immediate puncturing without catheter insertion. The primary and secondary patency rates for AVF at 6, 12, 18, and 24 months were 88.5%, 83.2%, 83.2%, and 83.2% and 96.0%, 96.0%, 93.2%, and 93.2%, respectively. The re-intervention rate was 0.27 ± 0.92/patient/ year. Conclusion: Based on these results, the author conclude that surgical salvage of a thrombosed AVF, when performed under local anesthesia by a skilled interventional nephrologist, offers favorable short- and long-term success and should be the preferred treatment.

Background: The use of ultrasound guided percutaneous transluminal angioplasty (UG-PTA), which use ultrasound as an imaging modality, is an evolving strategy. But, in Korea, this method is rarely used. We report our experiences with UG-PTA with respect to technical success rates and complication rates compared to conventional PTA (C-PTA), performed between 2010 and 2015 at Samsung Changwon Hospital, Korea. Methods: In our series, 53 cases of UG-PTA and 90 cases of C-PTA were reviewed, respectively. Cases of central vein stenosis, cephalic arch stenosis, arterial stenosis and thrombosis were excluded. However, cases of juxta-anastomotic stenosis and outflow vein stenosis were included. Results: Technical success was achieved in 96.2% (51 of 53) of cases in the UG-PTA group and in 93.3% (84 of 90) of cases in the C-PTA group, respectively (P = 0.710). Technical failure was experienced in a total 8 cases (UG-PTA group: 2/53, 3.8%; C-PTA group: 6/90, 6.7%). No differences were observed in complications. Conclusion: Duplex ultrasound-guided angioplasty for dialysis access in the outpatient setting is feasible, safe, and effective for peripheral venous stenotic lesions. It offers many advantages over conventional angiographic procedures, and, in the future, it has great potential to play a significant role in the management of these challenging patients.

Manganite perovskite has a wide variety of potential applications as an advanced material, for example, in magnetic random access memory, spintronics, magnetoelectric, magnetic field sensors and cooling technology, based on magnetism and magnetic materials. In work on cooling technology, magnetic materials show a magnetocaloric effect. Manganite perovskite has some fundamental properties, such as Curie temperature, magnetic entropy change, temperature span and relative cooling power. Current works report detailed properties of manganite perovskite in La0.7Ca0.3MnO3 doped with Cu, which show magnetocaloric effects. The samples were synthesized by a conventional solid state reaction. A small amount of doping Cu 1%~3% at a Mn site maintains the First-Order Magnetic Transition (FOMT) without leading into the Second-Order Magnetic Transition (SOMT). Maximum magnetic entropy change increased as the Cu-doped decreased. Introducing a small percentage of Cu-doped on La0.7Ca0.3Mn1-xCuxO3 also implies decreasing the Curie temperature, TC. For all samples under external application in a field of 10 kOe, these resulted in a slightly wider temperature span and the Relative Cooling Power (RCP) of about 39 J/kg to 47 J/kg as the Cu-doped decreased. The small amount of Cu-doping on La0.7Ca0.3MnO3 keeps the rate of relative cooling power in a wider temperature range. It may be beneficial for cooling technology based on magnetism and magnetic materials.

Modern technology for refrigerators and coolers is based on the chemical gas Chlorofluorocarbon (CFC) compression method that is indicative of a high consumption of electricity. The CFC is also understood as a reason for global warming. One of the solutions to this issue is magnetic refrigeration technology, which is environmentally friendly because it does not use any hazardous chemicals or ozone depleting/greenhouse gases. Magnetic refrigeration technology is based on the magnetocaloric effect of magnetic refrigerant materials. Exploring the magnetocaloric effect of magnetic refrigerant materials is important because these contain many of the physical properties needed for magnetic refrigeration technology. Herein, the present work reports on the magnetocaloric effect of La0.7Ca0.3Mn1?xSnxO3 (x = 0.0, x = 0.02 and x = 0.04) compound samples produced with the solid state reaction technique. Curie temperature TC obtained for the La0.7Ca0.3Mn1?xSnxO3 (x = 0.0, x = 0.02 and x = 0.04) are 260 K, 176 K and 170 K with -?SM max of 4.32 J×kg-1×K-1, 1.61 J×kg-1×K-1 and 1.24 J×kg-1×K-1 and a refrigerant capacity of 48 J/kg, 41.43 J/kg and 28.53 J/kg for x = 0.0, x = 0.02 and x = 0.04, respectively. A small addition of Sn-doped resulted in a significant decrease of more than 80 K on the Curie temperature scale compared to that of La0.7Ca0.3MnO3. The large gap in the decreasing magnetic temperature phase transition might be useful as an option of metal/transition metal doped for tuning the Curie temperature of magnetic refrigerant materials.

The magnetocaloric effect and the critical behavior near the first to second-order phase transition of La _0.7 Ca _0.3-x Sn _x MnO _3 compounds (with x = 0–0.04), which were prepared by a conventional solid state reaction method, have been investigated. With increasing Sn-doping, a systematic decrease in the Curie temperature ( T _C ) and the magnetic entropy change (Δ S _m ) are observed. We also pointed out that the width and the order of the magnetic phase transition in La _0.7 Ca _0.3-x Sn _x MnO _3 compounds can be easily modified by changing Sn concentration. The Banerjee criterion suggests that the Sn-undoped sample ( x = 0) undergoes a first-order phase transition (FOPT). Meanwhile, Sn-doped samples ( x = 0.02 and 0.04) undergo a second-order phase transition (SOPT). Based on the Kouvel-Fisher method and the critical isotherm analyses, we have determined the values of the critical exponents ( β , γ , and δ ) and T _C for two SOPT samples. The results obtained for x = 0.02 sample are β = 0.218, γ = 0.858, and δ = 4.717, which are close to those expected for the tricritical mean field theory. Whereas, β = 0.468, γ = 1.095 and δ = 3.315 obtained for x = 0.04 sample are close to those expected for the mean field theory. This suggests that the presence of Sn favors establishing the ferromagnetic long-range interactions in the sample.

The aim of the present study was to investigate the relationship among nutritional status, N-terminal probrain-type natriuretic peptide (NT–proBNP) and ventricular remodeling in hemodialysis (HD) patients. Serum concentrations of NT-proBNP were measured by immunoassay. Nutritional status was assessed using the subjective global assessment (SGA) score and malnutrition–inflammation score (MIS). Echocardiographic examinations were performed on all patients. Forty-four patients undergoing maintenance HD were enrolled in this study. Malnourished patients, assessed according to SGA, had higher levels of extracellular water (ECW) per kg body weight (BWt) than well-nourished patients (mean, 0.30 vs 0.26 l/ kg, respectively) and higher levels of NT-proBNP (median, 24,807 vs 4,342 pg/ml, respectively). MIS was positively correlated with left ventricular mass index (LVMI), log NT–proBNP and ECW/BWt (r =0.35, 0.45 and 0.38), and negatively correlated with fat mass and LV systolic dysfunction (r=–0.41 and –0.32). LV systolic dysfunction, LVMI and MIS were associated with log NT-proBNP levels. Multiple regression analysis showed that log NT–proBNP, mean arterial pressure and ECW/BWt were independently associated with LVMI. In conclusion, malnutrition in HD patients is accompanied by volume overload and associated with increased log NT–proBNP levels independent of volume status, and these levels are independently associated with increased LVMI. This suggests that malnutrition may affect ventricular remodeling or dysfunction in HD patients.