Synthesis of rGO supported Cu@FeCo catalyst and catalytic hydrolysis of ammonia borane.

Highly dispersed Cu@FeCo/rGO catalysts have been prepared by two-step reduction method and used for hydrogen production from ammonia borane (NH3BH3, AB) hydrolysis at 298 K. The activity and reusability of synthesized composite catalyst were much more higher than Cu@FeCo for AB hydrolysis dehydrogenation at 298 K. Kinetic study manifested that AB hydrolysis dehydrogenation with Cu@FeCo/rGO catalysts was approaching to the first order at different catalyst concentrations. The hydrolysis reaction completed within four minutes, and its maximum hydrogen production rate reached to 7863.0 ml min-1 g-1 at 298 K.

Piezo type mechanosensitive ion channel component 1 facilitates gastric cancer omentum metastasis.

The peritoneum, especially the omentum, is a common site for gastric cancer (GC) metastasis. Our aim was to expound the role and mechanisms of Piezo1 on GC omentum metastasis. A series of functional assays were performed to examine cell proliferation, clone formation, apoptosis, Ca2+ influx, mitochondrial membrane potential (MMP) and migration after overexpression or knockdown of Piezo1. A GC peritoneal implantation and metastasis model was conducted. After infection by si-Piezo1, the number and growth of tumours were observed in abdominal cavity. Fibre and angiogenesis were tested in metastatic tumour tissues. Piezo1 had higher expression in GC tissues with omentum metastasis and metastatic lymph node tissues than in GC tissues among 110 patients. High Piezo1 expression was associated with lymph metastasis, TNM and distant metastasis. Overexpressed Piezo1 facilitated cell proliferation and suppressed cell apoptosis in GC cells. Moreover, Ca2+ influx was elevated after up-regulation of Piezo1. Piezo1 promoted cell migration and Calpain1/2 expression via up-regulation of HIF-1α in GC cells. In vivo, Piezo1 knockdown significantly inhibited peritoneal metastasis of GC cells and blocked EMT process and angiogenesis. Our findings suggested that Piezo1 is a key component during GC omentum metastasis, which could be related to up-regulation of HIF-1α.

Co2O3/Co2N0.67 nanoparticles encased in honeycomb-like N, P, O-codoped carbon framework derived from corncob as efficient ORR electrocatalysts.

It is essential to develop cost-effective rechargeable metal-air batteries, with high activity, stability, and efficiency, that use non-precious metals (NPMs)-based cathodic oxygen reduction reaction (ORR) catalysts. Here, by using earth-abundant corncob (CC) as the carbon source, Co(OH)2, NaH2PO4, and melamine as the precursors, and KOH as the chemical activator, CoNP@bio-C-a is obtained and comparative studies are carried out with three other types of CC-derived carbon-based catalytic materials, namely, bio-C, CoP@bio-C, and CoNP@bio-C. Depending mainly on the formation of Co2O3/Co2N0.67 active sites (as p-n heterojunctions) and N, P, O-containing functional groups, the resultant CoNP@bio-C-a catalyst exhibits best electrocatalytic activity among the four types of catalysts; via a 4-electron pathway, it has good stability and good methanol tolerance. In addition, its unique honeycomb-like porous structure, high graphitization degree, and abundant oxygen-containing groups contribute to its excellent ORR activity. This study provides insights for exploring the application of heteroatom-doped biomass-derived carbon catalysts.

[Study on the relationship between transaminase activity and metabolic syndrome in Hui and Han nationality of Ningxia Province].

OBJECTIVE: To analyze the relationship between the transaminase activity in serum and metabolic syndrome( MS) and its related indicators in Hui and Han nationality of Ningxia Province. METHODS: Using the method of case-control study, people of regional organizations who received regular health checks in the General Hospital of Ningxia Medical University and Wuzhong City People's Hospital from the October 2011 to October 2012 were enrolled in the study. According to inclusion and exclusion criteria, we selected 877 unrelated cases with metabolic syndrome as the case group and 655 unrelated health cases as control group. Date were collected through questionnaire investigation, physical examination and laboratory tests. The association between the transaminase activity and MS was analyzed by Chi-square test, t test and analysis of variance. RESULTS: The average levels and abnormality rate of AST and ALT in case group were significantly higher than that of control group, especially the average levels and abnormality rate of ALT, there were significant difference( t =-3. 971, t =-6. 048, χ2= 11. 556, χ2=33. 231, all P < 0. 01). To control the AST and ALT levels of seventy-five percent in control group and 40 U/L as the boundary and divided all the research object into low, medium and high groups. After adjustment for gender, age, nationality, culture degree, smoking and drinking, the odds ratios for MS were 1. 663( 95% CI 1. 263-2. 189) and2. 126( 95% CI 1. 586-2. 852) in the people with the medium AST, ALT levels people and low AST and ALT levels people, the odds ratios for MS were 2. 801( 95% CI 1. 696-4. 624) and 4. 918( 95% CI 2. 980-8. 116) in the people with the high AST, ALT levels people and low AST and ALT levels people, the odds ratios for MS were 2. 517( 95% CI1. 530-4. 142) and 4. 194( 95% CI 2. 554-6. 885) in the people with the high AST, ALT levels people and low and medium AST and ALT levels people. With the number of components of metabolic syndrome increases, the average levels of AST, ALT increased gradually, there were significant difference( F = 7. 742, F = 11. 753, all P < 0. 01). Comparing the average levels of AST and ALT of different age groups, except the control group, there were significant difference( all P < 0. 05). The average levels of AST and ALT of Hui is higher than that of Han nationality, but there were no significant difference( all P > 0. 05). The average levels of AST and ALT of male was significantly higher than that of female, there were significant difference in addition to the average levels of AST of case group( all P < 0. 01). There were significant difference in the average levels of AST, ALT in case, control and total survey population between different BMI levels( all P <0. 05). CONCLUSION: The average levels of AST and ALT are closely related with the incidence of MS, in normal range, the levels of AST and ALT on the high side can increase the risk of MS, and the risk of MS creased significantly in the abnormal increase ones. The levels of AST and ALT can become an important factor to predict the risk of MS, synthetically evaluate the risk factors of MS and predict the progress of the MS.

Bimetallic NiCo functional graphene: an efficient catalyst for hydrogen-storage properties of MgH2.

Bimetallic NiCo functional graphene (NiCo/rGO) was synthesized by a facile one-pot method. During the coreduction process, the as-synthesized ultrafine NiCo nanoparticles (NPs), with a typical size of 4-6 nm, were uniformly anchored onto the surface of reduced graphene oxide (rGO). The NiCo bimetal-supported graphene was found to be more efficient than their single metals. Synergetic catalysis of NiCo NPs and rGO was confirmed, which can significantly improve the hydrogen-storage properties of MgH2. The apparent activation energy (E(a)) of the MgH2-NiCo/rGO sample decreases to 105 kJ mol(-1), which is 40.7% lower than that of pure MgH2. More importantly, the as-prepared MgH2-NiCo/rGO sample can absorb 5.5 and 6.1 wt% hydrogen within 100 and 350 s, respectively, at 300 °C under 0.9 MPa H2 pressure. Further cyclic kinetics investigation indicates that MgH2-NiCo/rGO nanocomposites have excellent cycle stability.

Synthesis of size-controlled Ag@Co@Ni/graphene core-shell nanoparticles for the catalytic hydrolysis of ammonia borane.

Size-controlled Ag0.04@Co0.48@Ni0.48 core-shell nanoparticles (NPs) were synthesized by employing graphene (rGO) with different reduction degrees as supports. The number of C=O and C=O functional groups on the surface of rGO might play a major role in controlling the particle size. The strong steric-hindrance effect of C=O resulted in the growth of large particles, whereas C=O contributed to the formation of small particles. The particle size of Ag0.04@Co0.48@Ni0.48 NPs supported on rGO with different reduction degrees decreased as the number of C=O functional groups decreased. The decrease in the particle size probably led to the increase in the catalytic activity towards the hydrolysis of ammonia borane (AB). The enhanced catalytic activity largely stemmed from the increasing active sites on the surface of catalysts owing to the decreasing particle size.

NbN nanoparticles as additive for the high dehydrogenation properties of LiAlH4.

The effects of NbN nanoparticles synthesized via a simple "urea glass" route on the dehydrogenation properties of LiAlH4 have been systematically investigated. The particle size of the as-synthesized NbN nanoparticles is determined to be about 10 nm. The surface configuration and dehydrogenation behaviors of the 2 mol% NbN-doped LiAlH4 (2% NbN-LiAlH4) system are also discussed. It is found that the 2% NbN-LiAlH4 sample starts to decompose at about 95 °C and releases a total of 7.10 wt% hydrogen, which is 55 °C lower than that of as-milled LiAlH4. The isothermal dehydrogenation kinetics shows that the 2% NbN-LiAlH4 sample could release approximately 6.10 wt% hydrogen in 150 min at 130 °C, whereas as-received LiAlH4 only releases about 0.63 wt% hydrogen under the same conditions, revealing that the enhancements arising upon adding NbN nanoparticles are almost 8-9 times that of as-milled LiAlH4. The activation energy (Ea) is calculated to be 71.91 and 90.87 kJ mol(-1) for the first and second hydrogen desorption of the NbN-LiAlH4 sample, a 38% and 32% reduction relative to as-received LiAlH4, respectively. A detailed modeling study shows that the first dehydrogenation step can be sufficiently interpreted with the nucleation and growth in a one-dimensional model based on the first-order reaction. More interestingly, the dehydrogenated LiAlH4 sample can recharge H2 under a 5.5 MPa hydrogen pressure. An SEM image of the dehydrogenated 8% NbN-LiAlH4 sample after HP-DSC under 5.5 MPa H2 shows that some nanorods appear.

Synthesis of triple-layered Ag@Co@Ni core-shell nanoparticles for the catalytic dehydrogenation of ammonia borane.

Triple-layered Ag@Co@Ni core-shell nanoparticles (NPs) containing a silver core, a cobalt inner shell, and a nickel outer shell were formed by an in situ chemical reduction method. The thickness of the double shells varied with different cobalt and nickel contents. Ag0.04 @Co0.48 @Ni0.48 showed the most distinct core-shell structure. Compared with its bimetallic core-shell counterparts, this catalyst showed higher catalytic activity for the hydrolysis of NH3 BH3 (AB). The synergetic interaction between Co and Ni in Ag0.04 @Co0.48 @Ni0.48 NPs may play a critical role in the enhanced catalytic activity. Furthermore, cobalt-nickel double shells surrounding the silver core in the special triple-layered core-shell structure provided increasing amounts of active sites on the surface to facilitate the catalytic reaction. These promising catalysts may lead to applications for AB in the field of fuel cells.

Excellent catalytic effects of highly crumpled graphene nanosheets on hydrogenation/dehydrogenation of magnesium hydride.

Highly crumpled graphene nanosheets (GNS) with a BET surface area as high as 1159 m(2) g(-1) was fabricated by a thermal exfoliation method. A systematic investigation was performed on the hydrogen sorption properties of MgH(2)-5 wt% GNS nanocomposites acquired by ball-milling. It was found that the as-synthesized GNS exhibited a superior catalytic effect on hydrogenation/dehydrogenation of MgH(2). Differential Scanning Calorimetry (DSC) and isothermal hydrogenation/dehydrogenation measurements indicated that both hydrogen sorption capacity and dehydrogenation/hydrogenation kinetics of the composites improved with increasing milling time. The composites MgH(2)-GNS milled for 20 h can absorb 6.6 wt% H(2) within 1 min at 300 °C and 6.3 wt% within 40 min at 200 °C, even at 150 °C, it can also absorb 6.0 wt% H(2) within 180 min. It was also demonstrated that MgH(2)-GNS-20 h could release 6.1 wt% H(2) at 300 °C within 40 min. In addition, microstructure measurements based on XRD, SEM, TEM as well as Raman spectra revealed that the grain size of thus-prepared MgH(2)-GNS nanocomposites decreased with increasing milling time, moreover, the graphene layers were broken into smaller graphene nanosheets in a disordered and irregular manner during milling. It was confirmed that these smaller graphene nanosheets on the composite surface, providing more edge sites and hydrogen diffusion channels, prevented the nanograins from sintering and agglomerating, thus, leading to promotion of the hydrogenation/dehydrogenation kinetics of MgH(2).