Preparation and electro-catalytic activity of nanoporous palladium by dealloying rapidly-quenched Al_(70)Pd_(17)Fe_(13) quasicrystalline alloy

The formation of nanoporous Pd was studied by electro-chemical dealloying a rapidly-quenched Al70Pd17Fe13 quasicrystal alloy in dilute NaCl aqueous solution,and the electro-catalytic activity of the nanoporous Pd towards methanol electro-oxidation was evaluated by cyclic voltammetry in 1 mol/L KOH solution.XRD and TEM analyses revealed that nano-decomposition of quasicrystal grains occurred in the initial stage of dealloying,and the fully dealloyed sample was composed of FCC-Pd phase.Scanning electron microscopy observation indicated that a maze-like nanoporous pattern was formed in the dealloyed sample,consisting of percolated pores of 5.20 nm in diameter in a skeleton of randomly-orientated Pd nano-ligaments with a uniform thickness of^5 nm.A retention of^12 at.%Al in the Pd nano-ligments was determined by energy dispersive X-ray spectroscopy(EDS).The nanoporous Pd demonstrated obvious electro-catalytic activity towards methanol electro-oxidation in alkaline environment.

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid

The graphene nanopowder for electro-catalytic oxidation of dopamine and uric acid in the presence of ascorbic acid has been investigated by cyclic voltammetry,linear polarization and chronoamperometry.The graphene nanopowder modified electrode was prepared using the drop coating method,which displayed excellent electrocatalytic activity towards the oxidation of dopamine and uric acid compared with the bare glassy carbon electrode in phosphate buffer solution at pH=7.0.Linear responses for dopamine and uric acid were obtained in the ranges of3.3μmol/L to 249.1μmol/L and 6.7μmol/L to 386.3μmol/L with detection limits of 1.5μmol/L and 2.7μmol/L(S/N=3),respectively.The response time was less than 2 s in case of dopamine and 3 s in case of uric acid,respectively.The results demonstrated that the graphene nanopowder had potential for detecting dopamine and uric acid.

Is the iron regulatory hormone hepcidin a risk factor for alcoholic liver disease?

Despite heavy consumption over a long period of time, only a small number of alcoholics develop alcoholic liver disease. This alludes to the possibility that other factors, besides alcohol, may be involved in the progression of the disease. Over the years, many such factors have indeed been identified, including iron. Despite being crucial for various important biological processes, iron can also be harmful due to its ability to catalyze Fenton chemistry. Alcohol and iron have been shown to interact synergistically to cause liver injury. Iron-mediated cell signaling has been reported to be involved in the pathogenesis of experimental alcoholic liver disease. Hepcidin is an iron-regulatory hormone synthesized by the liver, which plays a pivotal role in iron homeostasis. Both acute and chronic alcohol exposure suppress hepcidin expression in the liver. The sera of patients with alcoholic liver disease, particularly those exhibiting higher serum iron indices, have also been reported to display reduced prohepcidin levels. Alcohol-mediated oxidative stress is involved in the inhibition of hepcidin promoter activity and transcription in the liver. This in turn leads to an increase in intestinal iron transport and liver iron storage. Hepcidin is expressed primarily in hepatocytes. It is noteworthy that both hepatocytes and Kupffer cells are involved in the progression of alcoholic liver disease. However, the activation of Kupffer cells and TNF-α signaling has been reported not to be involved in the down-regulation of hepcidin expression by alcohol in the liver. Alcohol acts within the parenchymal cells of the liver to suppress the synthesis of hepcidin. Due to its crucial role in the regulation of body iron stores, hepcidin may act as a secondary risk factor in the progression of alcoholic liver disease. The clarification of the mechanisms by which alcohol disrupts iron homeostasis will allow for further understanding of the pathogenesis of alcoholic liver disease.

Electrochemical degradation of acidified reed pulp black liquor with three-dimensional electrode reactor

The electrochemical degradation of reed pulp black liquor containing lignin pretreated by acidification method was investigated using a three-dimensional electrode reactor. Using activated carbon as particle electrode, the effects of p H value, reaction temperature, electrolysis time and current on residual concentration of total organic carbon(TOC) were discussed in detail. The optimal conditions were obtained: pH 2.5, influent flow rate of 200 mL/min, 25 °C, 300 mA and 2h of electrolysis time, and the removal efficiency of TOC maintains at 35.57 %. The results of the electrochemical method indicate that ·OH radicals are produced in activated carbon anode in the electrolysis process and then adsorbed on the activated carbon surface. Microcell consists of ·OH radicals and the absorbed lignin. With the microcell reaction, the lignin is degraded, while the anodic polarized curve illustrates that the lignin is obviously oxidized in the anode. The contributions of direct and indirect electrolyses to the TOC removal ratio are about 50%, respectively.

Electro-catalytic degradation of sulfisoxazole by using graphene anode

Graphite and graphene electrodes were prepared by using pure graphite as precursor. The electrode materials were characterized by a scanning electron microscope（SEM）, X-ray diffraction（XRD） and cyclic voltammetry（CV） measurements. The electro-catalytic activity for degradation of sulfisoxazole（SIZ） was investigated by using prepared graphene or graphite anode. The results showed that the degradation of SIZ was much more rapid on the graphene than that on the graphite electrode. Moreover, the graphene electrode exhibited good stability and recyclability. The analysis on the intermediate products and the measurement of active species during the SIZ degradation demonstrated that indirect oxidation is the dominant mechanism, involving the electro-catalytic generation of OH and O_2^- as the main active oxygen species. This study implies that graphene is a promising potential electrode material for long-term application to electro-catalytic degradation of organic pollutants.

Hepatoprotective Activity of Yigan Mingmu Oral Liquid against Isoniazid/Rifampicin-Induced Liver Injuries in Rats

Background: To explore the hepatoprotective effect of Yigan mingmu oral liquid (YGMM) on isoniazid-rifampicin induced liver injury in rats. Methods: Total 38 SD rats were randomly divided into 6 groups including control group, model group, silymarin positive control group, and three YGMM treatment groups. Model group was administered intragastrically with INH (100 mg/kg) and RIF (100 mg/kg) for 14 days. Silymarin group and YGMM treatment groups were administered intragastrically with silymarin (100 mg/kg) and different doses of YGMM (1, 2.5, 5 mg/kg) 2 hours before INH and RIF administration from day 4 to day 14.?Results: Rats were sacrificed 16 hours after the last day treatment to determine the activities of serum alanine transaminase (ALT), aspartate transaminase (AST) and alkaline phosphatase (ALP), as well as total bilirubin (TB) content. Oxidative stress was evaluated by measuring total superoxide dismutase (T-SOD) and malondialdehyde (MDA) levels. Histopathological changes in liver tissues were observed under an optical microscope by using hematoxylin and eosin staining. The mice?in model groups showed significantly (p < 0.05) increased levels in AST, ALT, ALP, TB and MDA compared to their control groups;and showed significantly (p < 0.05) decreased level in T-SOD. These changes were significantly (p < 0.05) reversed by the YGMM treatments in a dose-dependent manner. Hepatic pathological changes were attenuated or even reversed by silymarin or YGMM treatments. Conclusions: YGMM has a good hepatoprotective activity on isoniazid-rifampicin induced liver injuries in rats.

The protective effect and action mechanisms of Icariin on oxidative injury of HUVEC induced by H2 02

Aim To investigate the protective effects of icariin（ICA） on oxidative injury of human umbilical vascu- lar endothelial cells （HUVEC） caused by H202 and analysis action machenisms of ICA. Methods HUVEC were cultured in DMEM medium with 10% fetal bovine serum and 1% antibiotic mixture comprising penicillin and strep- tomycin, at 37℃; with 5% CO2 in vitro. The model of oxidative injury was established by H202 （ 750 μmol · L^-1 ）. The cells were divided into six groups： control group, H202 group, H202 ＋ ICA（ 10-8, 10-7, 10-6 tool · L^-1 ） group and H202 ＋ DMSO （solvent） ; HUVEC were treated with different concentration ICA according to grou- os before 12h H202 treatment and cultured for 12, 24 and 36h respectively, the cell vitality （OD value） and the level of ROS was measured by MTT and ELISA. The apoptosis and death of HUVEC were detected using Annexin V-FITC/PI kit. Real Time RT-PCR was used to detect Bcl-2 and Bax mRNA expression in the HUVEC. Results Compared with control group, cell vitality significantly declined （P 〈 0.01 ） , the level of ROS and the number of apoptotic HUVEC notably increased （P 〈 0. 01 ） in H202 group. Compared with H202 group, ICA treatment could increase HUVEC vitality and reduce level of ROS （P 〈 0.01 or P 〈 0. 05） with manners of time-dependence and dose-dependence,ICA treatment could decrease the apoptosis and death rate of HUVEC （P 〈 0.01 ）. ICA treat- ment could also down-regulate the expression of Bax mRNA （ P 〈 0.05 ） and up-regulate the expression of Bcl-2 （ P 〈 0.05）. Conclusion The ICA can alleviate the oxidative injury of HUVEC induced by H202 treatment. The ac- tion mechanisms of ICA may, at least partly, be related to inhibit HUVEC apoptosis caused by H202 treatment through up-regulation of expression of Bcl-2 and down-regulation of expression of Bax mRNA.

Photothermal Catalytic Selective Oxidation of Isobutane to Methacrylic Acid over Keggin-Type Heteropolyacid

Thermal and photothermal catalytic selec-tive oxidation of isobutane to methacrylic acid(MAA)are comparatively studied over a keggin-type Cs2.9Cu0.34V0.49PMo12O40 het-eropolyacid acid.An introduction of light was observed to enhance both the i-C4H10 conversion and the MAA selectivity,and consequently the MAA formate rate,particularly at low temperatures.Characterization re-sults show that oxidation of methacrolein(MAL)to MAA is the rate-limiting step while UV light illumination promotes the oxidation ofσ-bonded MAL with OH groups toσ-bonded MAA on the catalyst surface.These results demonstrate a synergistic effect of thermal cataly-sis and photocatalysis in selective oxidation of isobutane to MAA,which suggests photother-mal catalysis as a promising strategy to catalyze the selective oxidation of higher hydrocar-bons at relative mild reaction conditions.

The effect of ornithine ingestion on carbohydrate metabolism during rest after acute resistance exercise in healthy young males

The effect of oral L-ornithine hydrochloride (0.1 g/kg BW) on energy expenditure during a rest period from 120 to 180 min after resistance exercise was evaluated by indirect calorimetry. Healthy male subjects who have no habit of resistance training underwent resistance exercise (chest press, lat pulldown, leg press, shoulder press, leg extension, and leg curl), with 3 sets of each exercise and 10 repetitions in each set at 90-s intervals, 30 min after ingestion of ornithine or placebo. Plasma ornithine levels immediately after, and 120 and 180 min after, resistance exercise were significantly greater after ingestion of ornithine than of placebo (Treatment: F = 347.1, P p2 = 0.95;Interaction: F = 160.7, P p2 = 0.95), but no significant difference in serum growth hormone levels was observed between the two treatments (Treatment: F = 0.1, P = 0.751, ηp2 = 0.01;Time: F = 1.7, P = 0.229, ηp2 = 0.16;Interaction: F = 2.4, P = 0.155, ηp2 = 0.21). Although there was no between-treatment difference in energy expenditure during the rest period 120 to 180 min after resistance exercise (Treatment: F = 0.1, P = 0.718, ηp2 = 0.02;Time: F = 0.1, P = 0.767, ηp2 = 0.01;Interaction: F = 0.1, P = 0.112, ηp2 = 0.26), with ornithine ingestion carbohydrate oxidation was significantly greater than with placebo from 170 to 180 min after exercise (Treatment: F = 0.8, P = 0.383, ηp2 = 0.09;Time: F = 9.7, P = 0.013, ηp2 = 0.52;Interaction: F = 5.8, P = 0.039, ηp2 = 0.39). Moreover, 180 min after exercise, serum free fatty acid levels after ornithine ingestion were lower than after placebo (Treatment: F = 0.3, P = 0.602, ηp2 = 0.03;Time: F = 34.6, P p2 = 0.79;Interaction: F = 5.6, P = 0.042, ηp2 = 0.38). A similar trend in 3-hydroxybutylate was observed. In conclusion, ornithine ingestion before resistance exercise may enhance post-exercise carbohydrate oxidation without changing total energy expenditure.

Dicyclopentamethylenethiuram Disulfide as Precursor of Mononuclear Complexes: Oxidative Cleavage of Metal-Metal Bond in [CpMo(CO)₃]₂and Molecular Structure of <i>cis</i>-[CpMo(CO)₂{S₂C-N(CH₂)₅}]

The reaction of [CpMo(CO)3]2 with dicyclopentamethylenethiuram disulfide in refluxing xylene resulted a novel mono nuclear complex, cis-[(CpMo(CO)2{S2C-N(CH2)5}] as red crystals in moderate yield. The compound was formed by the oxidative cleavage of metal-metal bond in [CpMo(CO)3]2 together with a reductive sulfur-sulfur bond scission in the ligand.

Electrochemical performance of NiAl-activated cathode for green hydrogen production

The current study presents for the first time the preparation of a NiAl(68%(mass)Ni)intermetallic compound through the induction heating technique as a cathode for alkaline water electrolysis.The high-purity target was confirmed by X-ray diffraction and scanning electron microscopy combined with energy dispersive X-ray analysis.The chemical activation of Al from the NiAl electrode was achieved in a 25%NaOH solution at 353 K for 72 h.The performance and stability tests in a 1 mol·L^(-1)KOH solution at 298 K demonstrated that the enhancement of the hydrogen evolution reactionwas 13 times higher in the activated NiAl electrode than in the non-activated NiAl electrode.In addition,the electrochemical tests showed that the activated NiAl electrode exhibited the best hydrogen evolution reaction performance.Based on the findings,it is believed that the induction heating technique is a promising route for preparing a highly active and cost-effective NiAl electrode for green hydrogen production.

Nanomagnetic CoPt truncated octahedrons:facile synthesis,superior electrocatalytic activity and stability for methanol oxidation

Nanomagnetic CoPt truncated octahedral nanoparticles （TONPs） were successfully synthesised through a facile one-pot strategy. These single crystal CoPt TONPs with an average size of about 8 nm exhibit excellent electrocatalytic performance of both activity and stability for methanol oxidation reaction （MOR）. The mass and specific activities of CoPt TONPs is 8 and 6 times higher than that of standard commercial Pt/C, respectively. After accelerated durability test （ADT）, the loss of electrochemical surface area （ECSA） for CoPt TONPs is only 18.5%, which is significantly less than that of commercial Pt/C （68.2%）, indicating that CoPt TONPs possess much better stability than commercial Pt/C in the prolonged operation. The Curie temperature of CoPt TONPs down to 8 nm is as high as 350 K with weak ferromagntism at room temperature （RT）, which is greatly valuable for recycling in the eletrocatalytic applications.

Towards High-performance Lithium-Sulfur Batteries: the Modification of Polypropylene Separator by 3D Porous Carbon Structure Embedded with Fe3C/Fe Nanoparticles

Lithium-sulfur(Li-S)batteries with high energy densities have received increasing attention.However,the electrochemical performance of Li-S batteries is still far from the satisfactory of the practical application,which can be mainly attributed to the shuttling of polysulfides and the slow reaction kinetics of polysulfide conversion.To address this issue,a 3D porous carbon structure constructed by 2D N-doped graphene and 1D carbon nanotubes with embedded Fe3C/Fe nanoparticles(NG@Fe3C/Fe)was designed and prepared by a simple programmed calcination method for the modification of polypropylene(PP)separator.The Fe3C/Fe nanoparticles demonstrate an excellent catalytic conversion and strong chemisorption towards polysulfides,while the unique architecture of N-doped graphene promotes the Li+/electron transfer and the physical adsorption of polysulfides.The electrochemical performance of the Li-S batteries with the NG@Fe3C/Fe-modified separator is significantly improved.A large discharge capacity of 1481 mA∙h∙g-1 is achieved at 0.2 C(1 C=1675 mA/g),and a high capacity of 601 mA∙h∙g-1 is maintained after discharged/charged for 500 cycles at a current rate of 1 C.This work provides a new approach for the development of high-performance Li-S batteries through the modification of the PP separator by rationally designed composites with large adsorption capability to polysulfides,good wettability to the electrolyte and high catalytic property.

Electrocatalytic oxidation of hydrazine with alizarin red S as a homogenous mediator on the glassy carbon electrode

Electro-catalytic oxidation and detection of hydrazine on a glassy carbon electrode,at pH 6.0,was studied by using alizarin red S as a homogeneous mediator.The overall number of electrons involved in the catalytic oxidation of hydrazine and that involved in the rate-determining step were four and one,respectively.The interfering effect of some cations,anions and organic compounds were examined.Peak current for this process varied linearly with the square root of the scan rate.The kinetic parameters,such as the electron transfer coefficient(α) and catalytic rate constant(k) ,were determined using cyclic voltammetry,linear sweep voltammetry and chronoamperometry.The electro-catalytic response was optimized with regards to the pH,scan rate,hydrazine concentration and other variables.

Poly(Dimethylbenzimidazolium) Iodide Assisted Dispersion of Multiwalled Carbon Nanotubes and Their Palladium Nanoparticle Hybrid

The multi walled carbon nanotubes(MWNTs) have always been as the catalyst supporting materials,but for high-performance composite catalysts, the dispersion and functionalization of MWNTs are important challenging problems. In this paper, Electrocatalytically active palladium nanoparticles(Pd NPs) on MWNTs with the high-performance and excellent solubility polymer, poly(dimethylbenzimidazolium) iodide(P(DMBI)-I-)as modifier and glue was first discussed. The results of transmission electron microscopy(TEM) demonstrate a better dispersion of MWNTs with the assist of P(DMBI)-I-. The Raman spectra indicate a strong π-π interaction between MWNTs and P(DMBI)-I-. Taking advantages of the coordination effect of imidazole groups and the electrostatic attraction to Pd NPs, the prepared Pd/MWNTs-P(DMBI)-I-(Pd/MPDI-) hybrid is of well electrocatalytic activity to the ethanol fuel cells by electrochemical measurements. So it is believed that P(DMBI)-Ican be further applied in the dispersion of different carbon-based materials and metal nanoparticles for fabricating more novel composites for catalyst and electrode material.