Abstract Introduction The aim of this study was to analyze risk factors for delayed graft function (DGF) after deceased donor kidney transplantation and to compare the clinical outcomes of non-DGF ...versus DGF recipients. Patients and methods From January 2004 to June 2008, 75/154 kidneys were transplanted into 74 recipients. We classified the recipients into two groups: group 1 ( n = 61) without DGF and group 2 ( n = 13) with DGF. Results On univariate analysis, recipient age ( P = .048) cause of brain death (traumatic brain injury vs disease, P = .016), blood urea nitrogen ( P = .002), serum creatinine ( P = .001), arterial pH ( P = .019), and serum sodium level ( P = .012) just before organ procurement showed significant differences. On multivariate analysis, the cause of brain death ( P = .015, hazard ratio HR: 7.086), the terminal serum creatinine ≥1.5 mg/dL before organ procurement ( P = .007, HR: 10.132), and recipient age over ≥50 years ( P = .021, HR: 7.767) were independent risk factors for the development of DGF. Graft failures occurred among 5/74 recipients with 5-year graft survivals between group 1 and group 2 of 91.7% and 84.6%, respectively. Patient death occurred in five cases, most by due to infection. The 5-year patient survival between groups 1 and 2 were 93.9% and 84.6%, respectively ( P = .106). Conclusion The independent risk factors for DGF were the cause of brain death, the terminal creatinine level, and the recipient age. In deceased donor kidney transplantation, DGF may have less effect on long-term patient and graft survivals.
Abstract Introduction Cytomegalovirus (CMV) can reactivate causing serious clinical problems during immunosuppression. CMV-specific CD8+ T cells play an important role in the control of CMV ...reactivation. Using pentameric major histocompatibility complex (MHC) peptide complexes, we investigated cellular immune responses to CMV among healthy individuals and kidney transplantation recipients in Korea, which is an endemic area of CMV infection. Materials and methods Analysis of CMV-specific T cells was performed on 28 healthy individuals and 40 recipients who bore human leukocyte antigen (HLA)-A2 or -A24. CMV pp65 pentamer-binding cells incubated with various monoclonal antibodies were measured by four-color flow cytometry. Results Detectable levels of pentamer+ CD8+ T cells were present in 109/139 samples (78.4%) that stained with the A*02NLV-pentamer, while 15/67 samples (22.4%) stained with the A*24QYD-pentamer ( P < .01). Among patients with HLA-A2, 22/24 (91.7%) samples showing positive CMV antigenemia revealed detectable pentamer+ CD8+ T cells, while 87/115 (75.7%) displaying negative CMV antigenemia had detectable pentamer+ CD8+ T cells ( P = .04). There was no significant difference in percentages of pentamer+ CD8+ T cells between patients who did versus who did not experience episodes of CMV infection. The subpopulation of CMV-specific CD8+ T cells in transplantation recipients was evaluated using phenotypic markers; memory cells comprised the majority of the CMV-specific CD8+ T-cell population. Conclusion The A*02NLV-pentamer complex was useful to monitor CMV-specific T cells. However, MHC pentamer-based techniques did not provide a clear distinction between patients who are or are not at risk for CMV infection.
A superconducting motor consisting of high temperature superconducting (HTS) rotor and air-core stator is under development in Korea Electrotechnology Research Institute. HTS motor was designed for ...having the rated power of 100 HP at 1800 rpm. HTS field winding is composed of sixteen HTS race track shaped coils wound with stainless steel-reinforced Bi-2223 tape conductor by react and wind fabrication method. Nomex paper was used for electrical insulation. Each of four field coil assemblies was constructed with four double pancake sub-coils, mechanically stacked and electrically connected in series. Four field coil assemblies were fixed on an aluminum support structure to make effective heat transfer. Voltage terminals were attached to both ends of joints to measure joint resistances. HTS field winding was tested at 77 K, and the Joule heats generated at all the joints was calculated. In this paper, design, construction and testing of HTS field winding, Joule heat generated by the joints, and operating current were discussed.
Electrooxidation of methanol in sulfuric acid solution was studied using Pt, Pt/Ni(1:1 and 3:1), Pt/Ru/Ni(5:4:1 and 6:3.5:0.5), and Pt/Ru(1:1) alloy nanoparticle catalysts, in relation to methanol ...oxidation processes in the direct oxidation methanol fuel cell. The Pt/Ni and Pt/Ru/Ni alloys showed excellent catalytic activities compared to those of pure Pt and Pt/Ru. The role of Ni as a catalytically enhancing agent in the oxidation process was interrogated using cyclic voltammetry, chronoamperometry, X-ray photoelectron spectroscopy, transmission electron microscopy, and X-ray diffraction. X-ray diffraction data showed alloy formation for all Pt/Ni, Pt/Ru/Ni, and Pt/Ru nanoparticles, whereas X-ray photoelectron spectroscopy confirmed that chemical states of Pt were exclusively metallic. The presence of metallic Ni, NiO, Ni(OH)2, NiOOH, metallic Ru, RuO2, and RuO3 was also confirmed. We found that the Pt4f binding energies for the Pt/Ni and Pt/Ru/Ni alloy nanoparticles were lower than those for clean Pt nanoparticles. The oxides that serve as the oxygen donors for the oxidation process, and the change in the electronic structure of the Pt component in the alloys versus those in Pt and Pt/Ru collectively account, we believe, for enhancement in rates of methanol oxidation. The difference in the peak shift in Pt4f between Pt/Ni and Pt/Ru alloy nanoparticles is discussed by using electronegativities of the three components: Pt, Ru, and Ni. A comparison between the alloy nanoparticle composition and that of disk alloy electrodes under similar conditions was made in terms of the surface-to-volume ratio and surface segregation of the alloying components.
This work is development of HTS motor at DOOSAN heavy industry and Korea Electrotechnology Research Institute in Korea, and is sponsored by DAPAS program which is supported by Korean government. The ...final aim of the project is realization of HTS motor in the field of industry such as large driving pumps, fans and compressors for utility and industrial environments. In the first phase (2001-2004), 100 hp HTS motor was developed in order to implement the preliminary technology for the large applicable HTS motor. All of the performance characteristics are well met to the designed ones. In second phase (2004-2007), 1 MW HTS motor is developed for the purpose to fully represent the design and manufacturing issues for the larger capacity machine. The machine is 2 pole and 3600 rpm, and all of the components are completely manufactured. This machine is now under assembly. This paper summarizes the status of 1 MW HTS motor development, such as design, construction, and experimental test results.
Abstract Patients with unresectable, beyond Milan criteria, hepatocellular carcinoma (HCC) invariably undergo palliative transarterial chemoembolization (TACE). The aim of this study was to compare ...the outcomes of conventional TACE versus liver transplantation (LT) in unresectable (beyond Milan criteria) HCC. Twelve patients underwent LT and 86 TACE for unresectable, beyond Milan criteria HCC. The inclusion criteria were a single tumor ≤6.5 cm or ≤5 tumors and all tumors ≤5 cm based on initial radiologic findings. We excluded patients with double primary cancers, age >60 years, vascular invasion, or extrahepatic spread. Survival rates were calculated using the Kaplan-Meier method. Multivariate analysis showed that TACE was a prognostic factor for survival (hazard ratio, 16.66, P = .000). The LT group showed significantly better survival than the TACE cohort. Two cases (16.7%) in the LT group recurred at a median time of 13.5 months. Survival rates at 1, 3, and 5 years were 100%, 88.9%, and 76.2% in the LT group, and 85.6%, 45.6%, and 21.4% in the TACE group, respectively. Patients with unresectable, beyond Milan criteria HCC should be given the option to receive LDLT, because LT offers a significantly better likelihood of survival than TACE.
Abstract Background The delayed onset of cytomegalovirus (CMV) infection after liver transplantation can place patients at risk for graft failure and mortality. Methods We compared early versus ...delayed onset of CMV infection to identify risk factors for mortality among liver transplant recipients in an endemic area. Results Among 710 consecutive adult liver transplant recipients, incidence of CMV infection was 47.5% (337/710). Male gender, biliary complications, acute rejection episodes, antilymphocyte antibodies high hemoglobin, and high total bilirubin were significantly different among patients with delayed versus early onset CMV infections. The overall incidence of early versus delayed CMV infections was 43.1% (306/710) versus 4.4% (31/710). Among them, 11.1% (34/306) and 25.8% (8/31) of patients developed CMV disease. Conclusion These results showed that a higher proportion of patients developed disease among delayed CMV infected patients ( P = .039). The overall and graft survival curves for patients with early onset CMV infections were better than those of patients who had delayed onset CMV infections ( P = .026 and P = .014). Recurrence of hepatitis B virus, hepatic dysfunction, and retransplantation were associated with increased mortality among patients who had a delayed CMV infection.
Abstract
Background
We aimed to assess absolute risk and benefit from OAC therapies in individual AF patients with liver cirrhosis (LC), and to develop the optimal dose selecting risk calculator for ...each patient.
Methods
We derived and validated a prediction model for major bleeding (MB) and stroke/systemic thromboembolism (SSTE) in AF patients with LC from two-center observational cohort (n=420 in derivation cohort, n=180 in validation cohort) with 4 treatment options (standard-, low-dose NOACs, warfarin, and no OACs). Readily available clinical variables were included in machine learning-based ensembled risk calculation models.
Results
Model calibration and discrimination was adequate with c-statistics of 0.770.66-0.87 for MB and 0.740.74-0.84 for SSTE. Three-year absolute risk increases (ARIs) for MB with standard-dose NOACs ranged from <10% in 37% of patients to >30% in 18% of patients, with low-dose NOACs ranged from <10% in 47% of patients to >30% in 12% of patients compared without OACs. Three-year absolute risk reductions (ARRs) for SSTE with standard-dose NOACs ranged from <7% in 48% of patients to >15% in 22% of patients, with low-dose NOACs ranged from <7% in 57% of patients to >15% in 17% of patients compared without OACs. The ARI cutoff for MB and ARR cutoff for SSTE with OAC were shown as >2.4%/year and >1.2%/year (c-statistics 0.810.78-0.83, 0.750.72-0.79).
Conclusions
Artificial intelligence combining clinical variables was found to predict individual patient’s bleeding and stroke/systemic embolism risks well and it can also guide each patient’s appropriate OAC dose in AF patients with LC (web-calculator can be accessed as: https://riskcalc.shinyapps.io/AFLC/).
