Long-Term Organ Function After HCT for SCD: A Report From the Sickle Cell Transplant Advocacy and Research Alliance.

Hematopoietic cell transplantation (HCT) is an established cure for sickle cell disease (SCD) supported by long-term survival, but long-term organ function data are lacking. We sought to describe organ function and assess predictors for dysfunction in a retrospective cohort (n = 247) through the Sickle cell Transplant Advocacy and Research alliance. Patients with <1-year follow-up or graft rejection/second HCT were excluded. Organ function data were collected from last follow-up. Primary measures were organ function, comparing pre- and post-HCT. Bivariable and multivariable analyses were performed for predictors of dysfunction. Median age at HCT was 9.4 years; the majority had HbSS (88.2%) and severe clinical phenotype (65.4%). Most received matched related (76.9%) bone marrow (83.3%) with myeloablative conditioning (MAC; 57.1%). Acute and chronic graft-versus-host disease (GVHD) developed in 24.0% and 24.8%. Thirteen patients (5.3%) died ≥1 year after HCT, primarily from GVHD or infection. More post-HCT patients had low ejection or shortening fractions than pre-HCT (0.6% â†’ 6.0%, P = .007 and 0% â†’ 4.6%, P = .003). The proportion with lung disease remained stable. Eight patients (3.2%) had overt stroke; most had normal (28.3%) or stable (50.3%) brain magnetic resonance imaging. On multivariable analysis, cardiac dysfunction was associated with MAC (odds ratio [OR] = 2.71; 95% confidence interval [CI], 1.09-6.77; P = .033) and severe acute GVHD (OR = 2.41; 95% CI, 1.04-5.62; P = .041). Neurologic events were associated with central nervous system indication (OR = 2.88; 95% CI, 2.00-4.12; P < .001). Overall organ dysfunction was associated with age ≥16 years (OR = 2.26; 95% CI, 1.35-3.78; P = .002) and clinically severe disease (OR = 1.64; 95% CI, 1.02-2.63; P = .043). In conclusion, our results support consideration of HCT at younger age and use of less intense conditioning.

Effect of halide-modified model carbon supports on catalyst stability.

Modification of physiochemical and structural properties of carbon-based materials through targeted functionalization is a useful way to improve the properties and performance of such catalyst materials. This work explores the incorporation of dopants, including nitrogen, iodine, and fluorine, into the carbon structure of highly-oriented pyrolytic graphite (HOPG) and its potential benefits on the stability of PtRu catalyst nanoparticles. Evaluation of the changes in the catalyst nanoparticle coverage and size as a function of implantation parameters reveals that carbon supports functionalized with a combination of nitrogen and fluorine provide the most beneficial interactions, resulting in suppressed particle coarsening and dissolution. Benefits of a carefully tuned support system modified with fluorine and nitrogen surpass those obtained with nitrogen (no fluorine) modification. Ion implantation of iodine into HOPG results in a consistent amount of structural damage to the carbon matrix, regardless of dose. For this modification, improvements in stability are similar to nitrogen modification; however, the benefit is only observed at higher dose conditions. This indicates that a mechanism different than the one associated with nitrogen may be responsible for the improved durability.

Composition- and morphology-dependent corrosion stability of ruthenium oxide materials.

Ruthenium oxide materials were evaluated as possible non-carbon-based supports for fuel cell catalysts. The effects of composition and morphology of ruthenium oxide materials on the conductivity and corrosion stability in the gas-diffusion electrode (GDE) configuration were thoroughly investigated. The compositions of the bulk and surface of three ruthenium oxide materials, along with the surface area and surface morphology, were compared. We have found that all tested ruthenium oxide powders exhibited higher corrosion stability compared to carbon. Full conversion of RuO(2).nH(2)O to the RuO(2) phase by postreduction in a hydrogen atmosphere leads to improved conductivity and corrosion stability.

Predictive modeling of electrocatalyst structure based on structure-to-property correlations of x-ray photoelectron spectroscopic and electrochemical measurements.

Chemical structure and catalytic activity of nonplatinum porphyrin-based electrocatalyst for oxygen reduction is characterized by combination of X-ray photoelectron spectroscopy (XPS) and rotating disk electrode. The goal of the study is to show how modifications in the molecular structure affect catalytic characteristics and how to use these structural modifications in a purposeful manner to increase catalytic activity. Initial correlation of structure to electrochemical performance is achieved through the application of principal component analysis (PCA) to curve-fits of high-resolution XPS spectra combined with results of electrochemical measurements. Furthermore, a predictive model that describes this correlation is build using the combination of genetic algorithm (GA) and multiple linear regression (MLR). Based on structure-to-property correlations, two types of active sites responsible for the catalytic activity, i.e., Co associated with pyropolymer and Co particles covered by oxide layer, are determined, and a dual-site for oxygen reduction on cobalt porphyrins is hypothesized, allowing for designing a catalyst structure with optimal performance characteristics.

Electrodeposition of gold particles on aluminum substrates containing copper.

Electrodeposition of adhesive metal films on aluminum is traditionally preceded by the zincate process, which activates the aluminum surface. This paper presents an alternative approach for activation of aluminum by using films containing 99.5% aluminum and 0.5% copper. Aluminum/copper films are made amenable for subsequent electrodeposition by anodization followed by chemical etching of aluminum oxide. The electrodeposition of gold is monitored with electrochemical impedance spectroscopy (EIS). Analysis of EIS data suggests that electrodeposition of gold increases the interfacial capacitance from values typical for electrodes with thin oxide layers to values typical for metal electrodes. Scanning electron microscopy examination of aluminum/copper films following gold electrodeposition shows the presence of gold particles with densities of 10(5)-10(7) particles cm(-2). The relative standard deviation of mean particle diameters is approximately 25%. Evaluation of the micrographs suggests that the electrodeposition occurs by instantaneous nucleation followed by growth of three-dimensional semispherical particles. The gold particles, which are electrically connected to the conductive aluminum/copper film, support a reversible faradaic process for a soluble redox couple. The deposited gold particles are suitable for subsequent metallization of aluminum and fabrication of particle-type films with interesting catalytic, electrical, and optical properties.