Eliminating drug target interference with specific antibody or its F(ab')2 fragment in the bridging immunogenicity assay.

Background: DB-1003 is a humanized anti-IgE monoclonal antibody with higher affinity than omalizumab. In the affinity capture elution (ACE)-based bridging electrochemiluminescent immunoassay (ECLIA) for antibodies to DB-1003, monkey serum IgE caused false-positive results. Materials & methods: The target-specific antibody or its F(ab')2 fragment was used to mitigate drug target interference in an ACE-based bridging ECLIA for the detection of anti-DB-1003 antibodies. Results: The sensitivity of the developed assay was at least 100 ng/ml. When the anti-drug antibody concentration was 250 ng/ml, the assay tolerated at least 20.0 µg/ml of the monkey IgE. Conclusion: Incorporating the target-specific antibody or its F(ab')2 fragment can overcome the interference from monkey serum IgE in ACE-based bridging ECLIA for anti-DB-1003 antibody detection.

Epitaxial Ultrathin Pt Atomic Layers on CrN Nanoparticle Catalysts.

The construction of platinum (Pt) atomic layers is an effective strategy to improve the utilization efficiency of Pt atoms in electrocatalysis, thus is important for reducing the capital costs of a wide range of energy storage and conversion devices. However, the substrates used to grow Pt atomic layers are largely limited to noble metals and their alloys, which is not conducive to reducing catalyst costs. Herein, low-cost chromium nitride (CrN) is utilized as a support for the loading of epitaxial ultrathin Pt atomic layers via a simple thermal ammonolysis method. Owing to the strong anchoring and electronic regulation of Pt atomic layers by CrN, the obtained Pt atomic layers catalyst (containing electron-deficient Pt sites) exhibits excellent activity and endurance for the formic acid oxidation reaction, with a mass activity of 5.17 A mgPt -1 that is 13.6 times higher than that of commercial Pt/C catalyst. This novel strategy demonstrates that CrN can replace noble metals as a low-cost substrate for constructing Pt atomic layers catalysts.

Titania-Supported Cu-Single-Atom Catalyst for Electrochemical Reduction of Acetylene to Ethylene at Low-Concentrations with Suppressed Hydrogen Evolution.

Electrochemical acetylene reduction (EAR) is a promising strategy for removing acetylene from ethylene-rich gas streams. However, suppressing the undesirable hydrogen evolution is vital for practical applications in acetylene-insufficient conditions. Herein, Cu single atoms are immobilized on anatase TiO2 nanoplates (Cu-SA/TiO2 ) for electrochemical acetylene reduction, achieving an ethylene selectivity of ≈97% with a 5 vol% acetylene gas feed (Ar balance). At the optimal Cu-single-atom loading, Cu-SA/TiO2 is able to effectively suppress HER and ethylene over-hydrogenation even when using dilute acetylene (0.5 vol%) or ethylene-rich gas feeds, delivering a 99.8% acetylene conversion, providing a turnover frequency of 8.9 × 10-2  s-1 , which is superior to other EAR catalysts reported to date. Theoretical calculations show that the Cu single atoms and the TiO2 support acted cooperatively to promote charge transfer to adsorbed acetylene molecules, whilst also inhibiting hydrogen generation in alkali environments, thus allowing selective ethylene production with negligible hydrogen evolution at low acetylene concentrations.

External Fields Assisted Highly Efficient Oxygen Evolution Reaction of Confined 1T-VSe2 Ferromagnetic Nanoparticles.

As a clean and effective approach, the introduction of external magnetic fields to improve the performance of catalysts has attracted extensive attention. Owing to its room-temperature ferromagnetism, chemical stability, and earth abundance, VSe2 is expected to be a promising and cost-effective ferromagnetic electrocatalyst for the accomplishment of high-efficient spin-related OER kinetics. In this work, a facile pulsed laser deposition (PLD) method combined with rapid thermal annealing (RTA) treatment is used to successfully confine monodispersed 1T-VSe2 nanoparticles in amorphous carbon matrix. As expected, with external magnetic fields of 800 mT stimulation, the confined 1T-VSe2 nanoparticles exhibit highly efficient oxygen evolution reaction (OER) catalytic activity with an overpotential of 228 mV for 10 mA cm-2 and remarkable durability without deactivation after >100 h OER operation. The experimental results together with theoretical calculations illustrate that magnetic fields can facilitate the surface charge transfer dynamics of 1T-VSe2 , and modify the adsorption-free energy of *OOH, thus finally improving the intrinsic activity of the catalysts. This work realizes the application of ferromagnetic VSe2 electrocatalyst in highly efficient spin-dependent OER kinetics, which is expected to promote the application of transition metal chalcogenides (TMCs) in external magnetic field-assisted electrocatalysis.

Stereoselective Synthesis of Chiral Hydrophenanthridines via a One-Pot Stepwise Aza-Michael/Michael/Michael Process.

A one-pot, two-step aza-Michael/Michael/Michael process was developed to diastereospecifically construct C6a,C10a-cis-hydrophenanthridines in a highly enantioselective manner (83-99% ee). The tricyclic products were provided in 50-99% isolated yields, sequentially promoted by bifunctional squaramide and diamine in a one-pot operation. This doubly annulative protocol indicated that the complicated polycyclic structures could be easily constructed via full employment of the available reaction sites of readily prepared precursors.

Ordered PtFeIr Intermetallic Nanowires Prepared through a Silica-Protection Strategy for the Oxygen Reduction Reaction.

Developing efficient and stable Pt-based oxygen reduction reaction (ORR) catalysts is a way to promote the large-scale application of fuel cells. Pt-based alloy nanowires are promising ORR catalysts, but their application is hampered by activity loss caused by structural destruction during long-term cycling. Herein, the preparation of ordered PtFeIr intermetallic nanowire catalysts with an average diameter of 2.6 nm and face-centered tetragonal structure (fct-PtFeIr/C) is reported. A silica-protected strategy prevents the deformation of PtFeIr nanowires during the phase transition at high temperature. The as-prepared fct-PtFeIr/C exhibited superior mass activity for ORR (2.03 A mgPt -1 ) than disordered PtFeIr nanowires with face-centered cubic structure (1.11 A mgPt -1 ) and commercial Pt/C (0.21 A mgPt -1 ). Importantly, the structure and electrochemical performance of fct-PtFeIr/C were maintained after stability tests, showing the advantages of the ordered structure.

MIL-101-Derived Mesoporous Carbon Supporting Highly Exposed Fe Single-Atom Sites as Efficient Oxygen Reduction Reaction Catalysts.

Fe single-atom catalysts (Fe SACs) with atomic FeNx active sites are very promising alternatives to platinum-based catalysts for the oxygen reduction reaction (ORR). The pyrolysis of metal-organic frameworks (MOFs) is a common approach for preparing Fe SACs, though most MOF-derived catalysts reported to date are microporous and thus suffer from poor mass transfer and a high proportion of catalytically inaccessible FeNx active sites. Herein, NH2 -MIL-101(Al), a MOF possessing a mesoporous cage architecture, is used as the precursor to prepare a series of N-doped carbon supports (denoted herein as NC-MIL101-T) with a well-defined mesoporous structure at different pyrolysis temperatures. The NC-MIL101-T supports are then impregnated with a Fe(II)-phenanthroline complex, and heated again to yield Fe SAC-MIL101-T catalysts rich in accessible FeNx single atom sites. The best performing Fe SAC-MIL101-1000 catalyst offers outstanding ORR activity in alkaline media, evidenced by an ORR half-wave potential of 0.94 V (vs RHE) in 0.1 m KOH, as well as excellent performance in both aqueous primary zinc-air batteries (a near maximum theoretical energy density of 984.2 Wh kgZn -1 ) and solid-state zinc-air batteries (a peak power density of 50.6 mW cm-2 and a specific capacity of 724.0 mAh kgZn -1 ).

An industrial perspective on catalysts for low-temperature CO2 electrolysis.

Electrochemical conversion of CO2 to useful products at temperatures below 100 °C is nearing the commercial scale. Pilot units for CO2 conversion to CO are already being tested. Units to convert CO2 to formic acid are projected to reach pilot scale in the next year. Further, several investigators are starting to observe industrially relevant rates of the electrochemical conversion of CO2 to ethanol and ethylene, with the hydrogen needed coming from water. In each case, Faradaic efficiencies of 80% or more and current densities above 200 mA cm-2 can be reproducibly achieved. Here we describe the key advances in nanocatalysts that lead to the impressive performance, indicate where additional work is needed and provide benchmarks that others can use to compare their results.

Enantioselective synthesis of trifluoromethyl substituted cyclohexanones via an organocatalytic cascade Michael/aldol reaction.

An enantioselective (92-99% ee) Michael/aldol cascade reaction between 4,4,4-trifluoroacetoacetates and α,ß-unsaturated enones was established in the presence of cinchona alkaloid-based primary amines. Various ß-CF3-cyclohexanones were constructed in high yields (81-99%) as a couple of separable diastereomers. This tandem reaction was sensitive to acidic co-catalysts, with a Michael/aldol condensation process favorably occurring to generate ß-CF3-cyclohexenones (42-69% yield, 84-96% ee) in the presence of trifluoroacetic acid.

A universal ligand mediated method for large scale synthesis of transition metal single atom catalysts.

There is interest in metal single atom catalysts due to their remarkable activity and stability. However, the synthesis of metal single atom catalysts remains somewhat ad hoc, with no universal strategy yet reported that allows their generic synthesis. Herein, we report a universal synthetic strategy that allows the synthesis of transition metal single atom catalysts containing Cr, Mn, Fe, Co, Ni, Cu, Zn, Ru, Pt or combinations thereof. Aberration-corrected high-angle annular dark-field scanning transmission electron microscopy and extended X-ray absorption fine structure spectroscopy confirm that the transition metal atoms are uniformly dispersed over a carbon black support. The introduced synthetic method allows the production of carbon-supported metal single atom catalysts in large quantities (>1 kg scale) with high metal loadings. A Ni single atom catalyst exhibits outstanding activity for electrochemical reduction of carbon dioxide to carbon monoxide, achieving a 98.9% Faradaic efficiency at -1.2 V.

Carbon Dioxide and Water Electrolysis Using New Alkaline Stable Anion Membranes.

The recent development and market introduction of a new type of alkaline stable imidazole-based anion exchange membrane and related ionomers by Dioxide Materials is enabling the advancement of new and improved electrochemical processes which can operate at commercially viable operating voltages, current efficiencies, and current densities. These processes include the electrochemical conversion of CO2 to formic acid (HCOOH), CO2 to carbon monoxide (CO), and alkaline water electrolysis, generating hydrogen at high current densities at low voltages without the need for any precious metal electrocatalysts. The first process is the direct electrochemical generation of pure formic acid in a three-compartment cell configuration using the alkaline stable anion exchange membrane and a cation exchange membrane. The cell operates at a current density of 140 mA/cm2 at a cell voltage of 3.5 V. The power consumption for production of formic acid (FA) is about 4.3-4.7 kWh/kg of FA. The second process is the electrochemical conversion of CO2 to CO, a key focus product in the generation of renewable fuels and chemicals. The CO2 cell consists of a two-compartment design utilizing the alkaline stable anion exchange membrane to separate the anode and cathode compartments. A nanoparticle IrO2 catalyst on a GDE structure is used as the anode and a GDE utilizing a nanoparticle Ag/imidazolium-based ionomer catalyst combination is used as a cathode. The CO2 cell has been operated at current densities of 200 to 600 mA/cm2 at voltages of 3.0 to 3.2 respectively with CO2 to CO conversion selectivities of 95-99%. The third process is an alkaline water electrolysis cell process, where the alkaline stable anion exchange membrane allows stable cell operation in 1 M KOH electrolyte solutions at current densities of 1 A/cm2 at about 1.90 V. The cell has demonstrated operation for thousands of hours, showing a voltage increase in time of only 5 µV/h. The alkaline electrolysis technology does not require any precious metal catalysts as compared to polymer electrolyte membrane (PEM) design water electrolyzers. In this paper, we discuss the detailed technical aspects of these three technologies utilizing this unique anion exchange membrane.

GPS Satellite Orbit Prediction at User End for Real-Time PPP System.

This paper proposed the high-precision satellite orbit prediction process at the user end for the real-time precise point positioning (PPP) system. Firstly, the structure of a new real-time PPP system will be briefly introduced in the paper. Then, the generation of satellite initial parameters (IP) at the sever end will be discussed, which includes the satellite position, velocity, and the solar radiation pressure (SRP) parameters for each satellite. After that, the method for orbit prediction at the user end, with dynamic models including the Earth's gravitational force, lunar gravitational force, solar gravitational force, and the SRP, are presented. For numerical integration, both the single-step Runge-Kutta and multi-step Adams-Bashforth-Moulton integrator methods are implemented. Then, the comparison between the predicted orbit and the international global navigation satellite system (GNSS) service (IGS) final products are carried out. The results show that the prediction accuracy can be maintained for several hours, and the average prediction error of the 31 satellites are 0.031, 0.032, and 0.033 m for the radial, along-track and cross-track directions over 12 h, respectively. Finally, the PPP in both static and kinematic modes are carried out to verify the accuracy of the predicted satellite orbit. The average root mean square error (RMSE) for the static PPP of the 32 globally distributed IGS stations are 0.012, 0.015, and 0.021 m for the north, east, and vertical directions, respectively; while the RMSE of the kinematic PPP with the predicted orbit are 0.031, 0.069, and 0.167 m in the north, east and vertical directions, respectively.

High-Indexed Pt3Ni Alloy Tetrahexahedral Nanoframes Evolved through Preferential CO Etching.

Chemically controlling crystal structures in nanoscale is challenging, yet provides an effective way to improve catalytic performances. Pt-based nanoframes are a new class of nanomaterials that have great potential as high-performance catalysts. To date, these nanoframes are formed through acid etching in aqueous solutions, which demands long reaction time and often yields ill-defined surface structures. Herein we demonstrate a robust and unprecedented protocol for facile development of high-performance nanoframe catalysts using size and crystallographic facet-controlled PtNi4 tetrahexahedral nanocrystals prepared through a colloidal synthesis approach as precursors. This new protocol employs the Mond process to preferentially dealloy nickel component in the ⟨100⟩ direction through carbon monoxide etching of carbon-supported PtNi4 tetrahexahedral nanocrystals at an elevated temperature. The resultant Pt3Ni alloy tetrahexahedral nanoframes possess an open, stable, and high-indexed microstructure, containing a segregated Pt thin layer strained to the Pt-Ni alloy surfaces and featuring a down-shift d-band center as revealed by the density functional theory calculations. These nanoframes exhibit much improved catalytic performance, such as high stability under prolonged electrochemical potential cycles, promoting direct electro-oxidation of formic acid to carbon dioxide and enhancing oxygen reduction reaction activities. Because carbon monoxide can be generated from the carbon support through thermal annealing in air, a common process for pretreating supported catalysts, the developed approach can be easily adopted for preparing industrial scale catalysts that are made of Pt-Ni and other alloy nanoframes.

Transcriptomic and metabonomic profiling reveal synergistic effects of quercetin and resveratrol supplementation in high fat diet fed mice.

Dietary quercetin and resveratrol have been frequently used in treating various diseases, but the underlying mechanisms are not entirely clear. Here, we report combined transcriptomic and metabonomic profiling that showed that the combined supplementation with quercetin and resveratrol produced synergistic effects on a high-fat diet-induced metabolic phenotype in mice. Histological and phenotypic improvements in serum and hepatic total cholesterol, insulin, fasting blood glucose, and HbA1c were also observed in mice receiving combined quercetin and resveratrol supplementation. This combined quercetin and resveratrol supplementation resulted in significant restoration of gene sets in functional pathways of glucose/lipid metabolism, liver function, cardiovascular system, and inflammation/immunity, which were altered by high fat diet feeding. The integration of transcriptomic and metabonomic data indicated quercetin and resveratrol supplementation enhanced processes of glycolysis and fatty acid oxidation, as well as suppressed gluconeogenesis. These alterations discovered at both the transcriptional and metabolic levels highlight the significance of combined "omics" platforms for elucidating mechanistic pathways altered by dietary polyphenols, such as quercetin and resveratrol, in a synergistic manner.

Synthesis and oxygen reduction activity of shape-controlled Pt(3)Ni nanopolyhedra.

Platinum-based alloys have been extensively shown to be effective catalysts for oxygen reduction reaction (ORR) in proton exchange membrane fuel cells (PEMFCs). Most of these catalysts are nanoparticles without shape control. Recently, extended Pt(3)Ni(111) surfaces prepared in ultrahigh vacuum were demonstrated to possess enhanced ORR catalytic activity as compared to the state-of-the-art carbon supported Pt (Pt/C) nanoparticle catalysts. How and whether this promising surface can be transformed into practical nanoscale electrocatalysts used in PEMFCs remain a challenge. We report a new wet-chemical approach of preparing monodisperse Pt(3)Ni nanoctahedra and nanocubes terminated with {111} and {100} facets, respectively. We further show that the ORR activity on the Pt(3)Ni nanoctahedra is approximately 5-fold higher than that of nanocubes with a similar size. Comparison of ORR activity between carbon-supported Pt(3)Ni nanoctahedra and commercial Pt/C reveals that the Pt(3)Ni nanoctahedra are highly active electrocatalysts. This synthetic strategy may be extended to the preparation of other shape-controlled fuel cell electrocatalysts.

Inhibitory effect of total lignan from Fructus Arctii on aldose reductase.

The potent inhibitory effect of the total lignan from the plant Fructus Arctii on aldose reductase was observed, suggesting its preventive potential on diabetic complications upon long term administration.

[Study on effects of baicalin, berberine and Astragalus polysaccharides and their combinative effects on aldose reductase in vitro].

OBJECTIVE: To observe the activities of baicalin, berberine and Astragalus polysaccharides and their combinative effects on aldose reductase (AR) by a screening model of aldose reductase inhibitor (ARI) in vitro. METHODS: The inhibition of AR by baicalin, berberine and Astragalus polysaccharides and positive drug (Epalrestat) in different concentrations were evaluated, and their combinative effects were studied according to orthogonal t design. RESULTS: Baicalin and berberine had remarkable inhibitory effects on AR, the inhibitory rates were (88.4 +/- 7.4)% and (69.0 +/- 9.4)% at the concentration of 300 microg/mL. However, the combinative effect of the inhibition on AR by the two compounds was antagonistic action. Astragalus polysaccharides had no activity of inhibition on AR. CONCLUSION: Baicalin and berberine are the potential AR inhibitors as they can inhibit the activity of AR in vitro.

Solution-based evolution and enhanced methanol oxidation activity of monodisperse platinum-copper nanocubes.

Shape-controlled catalysis: High-quality Pt-Cu nanocubes with an average size of about 8 nm (see picture, scale bar = 20 nm) were synthesized from a high-temperature organic solution system in the presence of various capping ligands. These cubic Pt-Cu nanocrystals terminated with {100} facets demonstrated a superior catalytic activity towards methanol oxidation compared to similar sized Pt-Cu and Pt nanospheres.

Multiparametric analysis of amino acids and organic acids in rat brain tissues using GC/MS.

Using design of experiment (DOE) theory coupled with multivariate statistical analysis, we have developed a simple and reliable GC/MS-based analytical assay for simultaneous analysis of amino acids and organic acids in rat brain tissue samples. The process of water extraction (pH 10.0) was extensively evaluated using brain tissue samples and a set of 21 reference standards. Acceptable calibration curves were obtained over a wide concentration range, 0.2-35.0 microg/mL for standards and 15.0-2.4 mL/g (tissue) for brain tissue samples. The precision was mostly better than 10% for both the mixed standards and the brain tissue samples. The brain tissue samples exhibited good stability within 48 h with RSD generally less than 15%. Furthermore, the developed analytical method was successfully applied in distinguishing the subtle variation among different parts of the brain tissues, such as cerebral cortex, hippocampus, and thalamus.