High entropy alloying strategy for accomplishing quintuple-nanoparticles grafted carbon towards exceptional high-performance overall seawater splitting

High entropy alloys (HEAs), a novel class of material, have been explored in terms of their excellent mechanical properties. Seawater electrolysis is a step towards sustainable production of carbon-neutral fuels such as H2, O2, and industrially demanding Cl2. Herein, we report a practically viable FeCoNiMnCr HEA nanoparticles system grafted on a conductive carbon matrix for promising seawater electrolysis. The comprehensive kinetics analysis of the hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and chlorine evolution reaction (CER) confirms the effectiveness of our system. As an electrocatalyst, HEAs grafted on carbon black show trifunctionality with promising kinetics, selectivity and enduring performance, towards seawater splitting. We optimize high entropy alloy decorated/grafted carbon black (HEACB) catalysts, studying their synthesis temperature to scrutinize the effect of alloy formation variation on the catalysis efficacy. During the catalysis, selectivity between two mutually competing reactions, CER and OER, in the electrochemical catalysis of seawater is controlled by the reaction media pH. We employ Mott-Schottky measurements to probe the band structure of the intrinsically induced metal-semiconductor junction in the HEACB catalyst, where the carrier density and flat band potential are optimized. The HEACB sample provides promising results towards overall seawater electrolysis with a net half-cell potential of about 1.65 V with good stability, which strongly implies its broad practical applicability.

FeCoNiMnCr High-Entropy Alloy Nanoparticle-Grafted NCNTs with Promising Performance in the Ohmic Polarization Region of Fuel Cells

We report a user-friendly methodology for the successful designing of targeted single-phased face-centered cubic (fcc) FeCoNiMnCr high-entropy alloy (HEA) nanoparticle-grafted N-doped carbon nanotubes (CNTs). The nanostructure assimilates the advantages of N-doped carbon and HEA nanoparticles as a core for the efficient promotion of electrochemical oxygen reduction reaction (ORR). It emulates the commercial Pt-C electrocatalyst for ORR and shows promise for better performance in the Ohmic polarization region of fuel cells. In addition, it ensures superior efficacy over those of numerous recently reported transition metal-based traditional alloy composites for ORR. The presented methodology has the potential to pave the way for the effective designing of a variety of targeted HEA systems with ease, which is necessary to widen the domain of HEA for numerous applications.

Atomic Arrangement Modulation in CoFe Nanoparticles Encapsulated in N-Doped Carbon Nanostructures for Efficient Oxygen Reduction Reaction

The properties and, hence, the application of materials are dependent on the way their constituent atoms are arranged. Here, we report a facile approach to produce body-centered cubic (bcc) and face-centered cubic (fcc) phases of bimetallic FeCo crystalline nanoparticles embedded into nitrogen-doped carbon nanotubes (NCNTs) with equal loading and almost similar particle size for both crystalline phases by a rational selection of precursors. The two electrocatalysts with similar composition but different crystalline structures of the encapsulated nanoparticles have allowed us, for the first time, to account for the effect of crystal structure on the overall work function of electrocatalysts and the concomitant correlation with the oxygen reduction reaction (ORR). This study unveils that the electrocatalysts with lower work function show lower activation energy to facilitate the ORR. Importantly, the difference between the ORR activation energy on electrocatalysts and their respective work functions are found to be identical (∼0.2 eV). A notable decrease in the ORR activity after acid treatment indicates the significant role of encapsulated FeCo nanoparticles in influencing the oxygen electrochemistry by modulating the material property of overall electrocatalysts.

High-entropy alloys for water oxidation: a new class of electrocatalysts to look out for

High-entropy alloys (HEAs) with five or more elements can provide near-continuous adsorption energies and can be optimized for superior persistent catalytic activity. This report presents electrochemical water oxidation facilitated by employing graphene and FeCoNiCuCr HEA nanoparticle based composites prepared via the mechanical milling of graphite-metal powders. The composite efficiently facilitates water oxidation with a low overpotential of 330 mV at 10 mA cm-2, and high specific and mass activities (∼143 mA cm-2 and 380 mA mg-1, respectively, at 1.75 V). Importantly, the composites exhibit excellent accelerated cycling stability with ∼99% current retention (after 3250 cycles). The HEA-based composites are anticipated to replace noble/precious metal based traditional electrocatalysts in the future, the use of which is a major obstacle in the technological scalability of electrochemical energy conversion and storage devices.

Ruthenium nanodendrites on reduced graphene oxide: an efficient water and 4-nitrophenol reduction catalyst

A green and efficient protocol is reported for the elegant design of reduced graphene oxide (rGO)-supported Ru nanodendrites for promotion of electrochemical water reduction in a wide pH range as well as for environmental remediation.

Unique One-Step Strategy for Nonmetallic and Metallic Heteroatom Doped Carbonaceous Materials

Nonmetallic and metallic heteroatom doped carbonaceous materials have garnered tremendous research attention due to a potential replacement to the precious Pt-group and (Ru, Ir)-oxide based catalysts and are essential part of the next-generation electrode catalysts for fuel cells, electrolyzers, and metal-air batteries. In this regard, we focus on three important categories of carbonaceous material, namely, metal-free heteroatom doped, transition metal heteroatom codoped, and carbon nitride (C₃N₄) based hybrid materials. Implications of various strategies, using one-step pyrolysis technique have been discussed for the effective design of heteroatom modified carbonaceous electrocatalysts. In this minireview, we outline the richness of one-step strategy for designing electrochemically active heteroatom doped carbon, transition metal-heteroatom codoped carbon, and C₃N₄ derived hybrid materials in the perspective of electrochemical energy conversion and storage devices. We also outline the future research direction in the development of highly efficient and sustainable electrocatalysts for oxygen electrochemistry. Finally, we wind up the article with the challenges and outlook on heteroatoms and transition metal-heteroatom codoped carbon material as an efficient and low-cost electrocatalysts, thereby promoting the development of this important area.

Energy-Efficient Rational Designing of Multifunctional Nanocomposites by Preferential Anchoring of Metal Ions via Fermi Level Positioning of Carbon Nanostructures

Despite the availability and dedicated studies on a variety of carbon nanostructures, amorphous carbon is still a preferred support for a wide range of commercially available metal catalysts. In order to shed some light on this, we carried out electroless deposition of metal nanoparticles on various carbon nanostructures such as amorphous carbon (a-C), carbon nanotubes (CNTs), and nitrogen-doped CNTs (NCNTs) under similar experimental conditions. The main objective is to elucidate the preferable deposition on a particular carbon nanostructure, if any, and understand the underlying mechanism. Experimental results unveil preferred electroless deposition of metal nanoparticles on a-C over CNTs and NCNTs. Notably, the deposition is nicely correlated with the position of the Fermi level (E_F) with respect to the Mⁿ⁺ ↔ M⁰ redox level (E₀). Remarkably, E_F is found to be in the following order NCNT > CNT > a-C and the smaller gap (E₀-E_F) favors the faster electron transfer, resulting in the preferential reduction of Mⁿ⁺, yielding finer nanoparticles on a-C. We believe that this approach can pave the way for designing noble metal-based carbon nanocomposites for a variety of applications, ranging from environmental redemption to electrochemical energy harvesting. As case studies, we have explored the nanocomposites for various catalytic activities and found them to be very competent with recently reported various state-of-the-art electrocatalysts and their commercial counterparts.

Inner Sphere Electron Transfer Promotion on Homogeneously Dispersed Fe-Nx Centers for Energy-Efficient Oxygen Reduction Reaction

The study reports the optimized incorporation of pyridinic nitrogen in nitrogen-doped carbon nanotubes (CNTs) to realize effective Fe-N_x centers throughout the framework. The study unveils nitrogen as a valuable asset to promote the homogeneous dispersion of Fe moieties throughout the CNT framework, which is a necessary component to institute uniform Fe-N_x centers. In addition, pyridinic nitrogen causes disruption in strongly delocalized π-electrons, which impart electron-withdrawing nature in the carbon matrix, resulting in an anodic shift in oxygen reduction reaction (ORR) onset potential (E_onset). The direct interaction of Fe-N_x with O₂, as evidenced by poisoning and computational studies, ensures the preferential inner sphere electron transfer mechanism. Despite the alkaline medium, the outer sphere electron transfer mechanism was muted, with suppressed HO₂^- generation, preferential 4e^- reduction pathways, and excellent cyclic stability. The study indicates the dependency of ORR half-wave potential on the electron transfer mechanism. The poisoning study unveils the direct involvement of Fe-N_x electroactive centers in facilitating ORR in alkaline medium. It further indicates a noticable increase (up to ∼25%) in peroxide generation-an unwanted ORR intermediate-and concomitant reduction in average electron transfer no. per oxygen molecule.

Mechanistic Investigation into Efficient Water Oxidation by Co-Ni-Based Hybrid Oxide-Hydroxide Flowers

Oxides are envisioned as promising catalysts to facilitate water oxidation, and the benign presence of hydroxide moieties can further enhance the catalyst performance. However, the nature of synergy between oxides and hydroxides remains elusive. In this study, we have designed a one-pot solution growth technique for the synthesis of flower-shaped N-doped-C-enveloped NiCo₂O₄/Ni_xCo_(1-x)(OH)_y catalysts with varying oxide and hydroxide contents and investigated their water oxidation behavior. The correlation between performance-determining parameters involved in water oxidation, such as the onset potential and overpotential with oxide and/or hydroxide content, oxidation states (oxides), and elemental composition (Co/Ni content), and the possible ways to achieve their optimal values are discussed in detail. Our observations conclude that the onset potential and overpotential are minimal for the hybrid oxide-hydroxide bimetallic system compared with pristine hydroxide or oxide. The optimal hybrid catalyst shows excellent current density, low Tafel slope (82 mV/dec), and low onset potential (281 mV at 2 mA/cm²) and overpotential (348 mV at 10 mA/cm²), besides enduring operational stability in alkaline medium. The low Tafel slope suggests the preferable kinetics for water oxidation, and the poisoning study reveals the direct involvement of metal as active sites. The overall study unveils the synergy in the Co-Ni-based binary transition-metal oxide-hydroxide hybrid, which makes it a potential candidate for water oxidation catalysts, and hence, it is expected that the hybrid will find applications in energy conversion devices, such as electrolyzers.

Rational geometrical engineering of palladium sulfide multi-arm nanostructures as a superior bi-functional electrocatalyst

Geometrical tunability offers sharp edges and an open-armed structure accompanied with a high electrochemical active surface area to ensure the efficient and effective utilization of materials by exposing the electrochemical active sites for facile accessibility of reactant species. Herein, we report a one-step, single-pot, surfactant-free, electroless, and economic route to synthesize palladium sulfide nanostructures with different geometries at mild temperatures and their catalytic properties towards the oxygen reduction reaction (ORR) and methanol electro-oxidation (MOR). For ORR, the positive on-set, half wave potentials, smaller Tafel slope, high electrochemical active surface area, large roughness factor, and better cyclic stability of the proposed nanostructures as compared to those of the commercial state-of-the-art Pt-C/PdS catalysts suggest their superiority in an alkaline medium. In addition, high mass activity (J_f ∼ 715 mA mg^-1), in comparison with that of the commercial state-of-the-art Pt-C/PdS catalysts (J_f ∼ 138/41 mA mg^-1, respectively), and high J_f/J_b (1.52) along with the superior operational stability of the multi-arm palladium sulfide nanostructures towards MOR advocates the bi-functional behavior of the catalyst and its potential as a promising Pt-free anode/cathode electrocatalyst in fuel cells.

Stability of Sputter Deposited Al-Cu Bilayers on SiO2

An investigation of the stability and electrical characteristics of Aluminum-Copper bilayer films on SiO2 has been carried out. In this investigation, a thin layer of sputtered aluminum is used as a diffusion barrier/adhesion promoter between the copper and SiO2. The electrical performance of these structures when subjected to thermal cycles and applied biases is determined. The interactions and diffusion of copper through aluminum into SiO2 was investigated using both blanket films and MOS capacitors. Results are compared with those obtained from structures of Al and Cu metallization on SiO2. Samples were annealed at various temperatures in the range of 200°C to 500°C. Analysis using four-point probe resistivity measurements, X-ray diffraction, and Rutherford Back Scattering were carried out. MOS capacitors are used to establish performance under applied bias. Capacitance-Voltage characteristics of formed alloys are discussed. These results will be presented and discussed in view of the applicability of aluminum as the adhesion promoter for copper interconnections on SiO2.

Functional profiling in stage IV NSCLC: A phase II trial of individualized therapy

e19079

Background: The introduction of new classes of agents has improved survival in NSCLC yet the accurate selection of candidates for these often costly & toxic drugs remains a challenge. Genomic platforms have identified several prognostic & predictive factors e.g. ERCC1, RRM1/2, EGFr mutations but the comparatively small number of known cellular analytes has limited their broad application. Methods: To address the complexity and redundancy of cell-death signaling pathways, we applied Ex Vivo Analysis of Programmed Cell Death (EVA/PCD) (Nagourney, R. Curr Treat Options in Oncol. 2006) to select therapies for chemo- naïve pts with metastatic NSCLC. This functional platform uses morphologic and metabolic endpoints to gauge cellular response to drugs & signal transduction inhibitors in human tumor microspheroids isolated from surgical biopsies. Modified Z-scores & synergy analyses (median-effect) were used to identify the ex vivo best regimen (EVBR) for each pt. from FDA-approved NSCLC drugs. All pts signed informed consent. Results: 22/25 (88%) pts are evaluable with 3/25 (12%) excluded, 1 for CVA & 2 inadequate PFS at time of treatment. There were CR = 2/22 (9%); PR = 10/22 (45%); SD = 9/22 (41%) & PD = 1/22 (5%) for an ORR = 12/22 (54%) & CBR = 21/22 (95%). 1st line EVBR were CDDP/Gemcitabine 10/25 (40%); CDDP/Taxane 7/25(28%); Erlotinib 5/25(20%); CDDP/Vinorelbine 1/25 (4%); CDDP/Irinotecan1/25(4%) & Ifex/Gemcitabine1/25(4%). Six of 22 (27%) stage IV pts were converted to surgical and/or radiation candidates by therapy. Accrual continues with current TTP ranges from 1.2–35+ months and OS from 1.7 to 46+ months. Conclusions: EVA/PCD ORR in Stage IV NSCLC of 54%, many durable, compares very favorably with reports in this population. By examining drug-induced cell death events in native-state microspheroids, this platform has the unique capacity to capture stromal, vascular and inflammatory cell interactions with tumor cells, now known to be crucial for clinical response prediction. EVA/PCD analysis in NSCLC warrants further evaluation. Supported by the Memorial Medical Center Foundation of Long Beach.

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GM and KM allotypes and GM RFLP allogenotypes in Micronesians from Nauru

Immunoglobulin allotypes of the GM and KM systems were determined in a sample of Micronesian subjects from Nauru. Four GM haplotypes were identified in the sample: GM*1,3 23 5, 10,11,13,14, GM*1,17 23' 21, GM*1,3 23' 5,10,11,13,14, and GM*1,2,17 23' 21, although the last of these may have been introduced by non-Micronesian admixture. The frequency of the KM*1 allele is 0.115 +/- 0.033, which is slightly lower than reported in Micronesians from the Caroline Islands. RFLPs generated by the enzymes Taq I and Pvu II and detected by a Hu gamma 4 probe were related to GM phenotypes. The haplotypes GM*1,3 +/- 23 5,10,11,13,14 were strongly associated with a Taq I 5.0-kb band. The presence and absence of the allotype G2M 23 were marked by a Pvu II 7.0 + 2.0 kb pair and a Pvu II 9.0-kb fragment, respectively. GM*1,17 23' 21 was strongly associated with a Pvu II 5.0 + 2.7 kb pair. The different relationships between GM haplotypes and Hu gamma 4 RFLPs in Micronesians and Caucasians indicate that a universal GM allogenotyping procedure cannot yet be developed; instead, population-specific procedures are necessitated by differences in GM allotype arrangements between populations.

Detection of endotoxins in human blood and plasma. An improved in-vitro pyrogen test

We describe an improved in-vitro procedure for detection of endotoxin in human blood and plasma by use of Limulus amoebocyte lysate. Increasing concentrations of Escherichia coli endotoxin added to a constant amount of the lysate cause a proportional increase in protein precipitated by the endotoxin. By measuring the amount of protein precipitated, it was possible to determine the equivalent E. coli endotoxin concentration in unknown samples, when samples were run with E. coli endotoxin standards and negative controls. The E. coli endotoxin, present in human whole blood and platelet-rich plasma, failed to react with the lysate. However, the concentration of endotoxin in whole blood and platelet-rich plasma could be measured with this Limulus test after lysing the platelets to release the endotoxin and subsequently removing the inhibitory proteins by chloroform precipitation. With this procedure it was possible accurately and repeatedly to determine E. coli equivalent endotoxin concentrations as low as 195 ng per liter of whole blood or 49 ng per liter of platelet-rich plasma.

Detection of endotoxins in human blood and plasma. An improved in-vitro pyrogen test

We describe an improved in-vitro procedure for detection of endotoxin in human blood and plasma by use of Limulus amoebocyte lysate. Increasing concentrations of Escherichia coli endotoxin added to a constant amount of the lysate cause a proportional increase in protein precipitated by the endotoxin. By measuring the amount of protein precipitated, it was possible to determine the equivalent E. coli endotoxin concentration in unknown samples, when samples were run with E. coli endotoxin standards and negative controls. The E. coli endotoxin, present in human whole blood and platelet-rich plasma, failed to react with the lysate. However, the concentration of endotoxin in whole blood and platelet-rich plasma could be measured with this Limulus test after lysing the platelets to release the endotoxin and subsequently removing the inhibitory proteins by chloroform precipitation. With this procedure it was possible accurately and repeatedly to determine E. coli equivalent endotoxin concentrations as low as 195 ng per liter of whole blood or 49 ng per liter of platelet-rich plasma.

An improved in vitro pyrogen test: to detect picograms of endotoxin contamination in intravenous fluids using limulus amoebocyte lysate

A method for in vitro pyrogen testing using Limulus amoebocyte lysate (LAL) has been described. The method is based upon the measurement of endotoxin-precipitable protein and can be used to measure picogram quantities equivalent to E. coli endotoxin in unknown solutions. When increasing concentrations of E. coli endotoxin are added to a constant amount of LAL and the reaction is allowed to proceed to completion, there is a proportional increase in the protein precipitated by endotoxin. Therefore, by measuring the amount of protein precipitated from LAL, it is possible to determine the equivalent E. coli endotoxin concentration in unknown solutions, when samples of the unknowns are run simultaneously with E. coli endotoxin standards and negative controls. The endotoxin proportional precipitation of protein occurs in reaction mixture showing gelation as well as in reaction mixture where the levels of endotoxin are lower than required for gelation. Determination of precipitated protein provides greater sensitivity for endotoxin detection than the gelation methods currently in use.

Effects of dextrothyroxine on hyperlipidemia and experimental atherosclerosis in beagle dogs

Beagle dogs, 24 +/- 6 months old, fed a thiouracil-free semi-synthetic diet containing hydrogenated coconut oil and cholesterol (SS diet) for 12 months, developed marked hyperlipidemia and severe atherosclerosis. SS diet produced a marked elevation of serum cholesterol, triglyceride, phospholipid, and beta-lipoprotein and severe atherosclerosis in large and small arteries. Intimal fatty lesions were always present in the abdominal aorta and many of its branches. Large and small coronary arteries showed similar lesions. The degree of atherosclerosis was directly related to circulating lipid levels. Dextrothyroxine, at dose levels of 0.1 (equivalent to normal human dose) and 0.5 mg/kg body weight, produced a significant dose related lowering of serum lipids and was associated with a markedly decreased severity of aortic and coronary artery lesions. Untreated control dogs that were maintained on purina dog meal developed neither hyperlipidemia nor atherosclerosis.