查找使用阿拉丁产品的科研文献

Dielectric strength of glass fibre fabric reinforced epoxy by nano-Al2O3

Shuang Wang,Yu Chen,Jiale Mao,Cong Liu,Lei Zhang,Yonghong Cheng,Chaoyun Du,Toshikatsu Tanaka

La(OH)3-decorated NiFe nanoparticles as efficient catalyst for hydrogen evolution from hydrous hydrazine and hydrazine borane

Hongtao Zou,Feng Guo,Minghong Luo,Qilu Yao,Zhang-Hui Lu

Ultrafine NiFe nanoparticles (NPs) decorated by La(OH) 3 have been successfully prepared via a facile one-step co-reduction method without the help of surfactant or support. It was found that after being decorated with La(OH) 3 , the NiFe–La(OH) 3 NPs have a smaller particle size and lower crystallinity . The resultant NiFe–La(OH) 3 nanocatalyst exhibits an excellent catalytic activity , 100% H 2 selectivity, and satisfied recyclability for hydrogen evolution from hydrous hydrazine (N 2 H 4 ·H 2 O) at 343 K under alkaline conditions, giving a high turnover frequency (TOF) value of 100.6 h −1 , which is more than 35 times higher than pure NiFe NPs (2.8 h −1 ). The kinetics study shows that with respect to the concentration of catalyst and N 2 H 4 , the N 2 H 4 dehydrogenation reaction follows fist-order kinetics and zero-order kinetics, respectively. Furthermore, NiFe–La(OH) 3 also exhibits an outstanding performance and excellent recycle stability during high dehydrogenation of hydrazine borane (N 2 H 4 BH 3 ). The excellent performances for the dehydrogenation of N 2 H 4 and N 2 H 4 BH 3 could be attributed to the strong interaction between La(OH) 3 and NiFe NPs, as well as ultrafine and low crystalline NiFe NPs due to the addition of La(OH) 3 .

Penicimutanin C, a New Alkaloidal Compound, Isolated from a Neomycin-Resistant Mutant 3-f-31of Penicillium purpurogenum G59

Nan Wang,Yuan Dong,Yu Yang,Rui Xu,Chang-Wei Li,Cheng-Bin Cui

Penicimutanin C, a new alkaloidal compound, was isolated from the neomycin-resistant mutant strain 3-f-31 of the marine-derived fungus, Penicillium purpurogenum G59, together with four known compounds. The structure of penicimutanin C, including the absolute configuration, was determined by spectroscopic and chemical methods. The absolute configuration of penicimutanin A was also re-confirmed by Marfey's and chiral HPLC analyses of the hydrolyzed products. Penicimutanins C and A inhibited the proliferation of five human cancer cell lines to some extent. Penicimutanin C is the third dimer of diketopiperazine and penicimutanolone, which are only produced by mutants of P. purpurogenum G59 isolated to date, and it showed cytotoxic activity against human cancer cell lines. The neomycin-resistant screening strategy has been previously successfully used to discover new compounds by activating silent metabolites in fungi, and the present results provide an additional example of the effectiveness of this method. Graphical

Enhancing quantum yield of CsPb(BrxCl1-x)3 nanocrystals through lanthanum doping for efficient blue light-emitting diodes

Shuai Zhang,Hongli Liu,Xianggao Li,Shirong Wang

All-inorganic perovskite quantum dots (PQDs) have attracted great attention in optoelectronic applications . However, compared with green and red PQDs, the poor photoluminescence quantum yield (PLQY) and terrible external quantum efficiencies (EQE) of blue-emission PQDs light-emitting diodes (QLEDs) have limited their further development in display field. Here, a general strategy for enhancing PLQY and EQE through lanthanum ions doping is proposed. Density functional theory (DFT) calculations confirmed that the partial substitution of La 3+ for Pb 2+ leads to a reduced defect states and an increased radiative recombination , meanwhile, a higher carrier temperature and exciton binding energy are also obtained. In consequence, a maximum PLQY of 84.3% is obtained for La 3+ -doped CsPb(Br x Cl 1-x ) 3 PQDs with emissions ranging from 448 to 500 nm. In terms of devices, phase separation and ion migration are effectively alleviated with La 3+ profiting from the constricted lattice and stronger interaction between La and Cl. Resultantly, QLEDs with La 3+ -doped PQDs show the maximum EQE of 2.17% (480 nm) and 3.25% (489 nm), which is higher than state-of-the-art records at this wavelength.

Preparation and characterization of poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/pullulan-gelatin electrospun nanofibers with shell-core structure

Fanchen Sun,Jing Guo,Yuanfa Liu,Yue Yu

In this study, hydrophilic pullulan, which is favorable for cell adhesion, proliferation, and differentiation, was selected as a modifier for the preparation of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P(3HB-co-4HB))/pullulan nanofibers via electrospinning to improve the biocompatibility of P(3HB-co-4HB) and increase the drug loading of composite fibers. Alkyl polyglycoside was used as the emulsifying agent to promote emulsification and stabilize the P(3HB-co-4HB)/pullulan composite solution. Drug-loading property of the nanofibers with a shell-core structure is increased because gelatin was not formed into fibers via electrospinning, thereby forming a stable drug-containing gelatin solution in the core layer. Finally, P(3HB-co-4HB)/pullulan-gelatin shell-core nanofibers were prepared. The intermolecular interaction, morphology, crystallization properties, mechanical properties, morphology, sustained release, and biocompatibility of composite nanofibers were characterized. Results show that the crystallization property of P(3HB-co-4HB)/pullulan composite nanofibers increases continuously with an increase in the pullulan content. As the pullulan content increases, the strain and stress of P(3HB-co-4HB)/pullulan nanofibers increase initially and decrease later. At the mass ratio of P(3HB-co-4HB) to pullulan of 10:2, P(3HB-co-4HB)/pullulan composite nanofibers exhibit a uniform morphology with an average diameter of 590 nm and porosity of 70.71%. At this mass ratio, the P(3HB-co-4HB)/pullulan-gelatin/drug shell-core structure, which sustained a release effect for more than 180 h, has potential applications as biomaterials without cytotoxicity.

Self-Supported 3 D Ultrathin Cobalt–Nickel–Boron Nanoflakes as an Efficient Electrocatalyst for the Oxygen Evolution Reaction

Hefeng Yuan,Shiwei Wei,Bin Tang,Zizai Ma,Jinping Li,Manab Kundu,Xiaoguang Wang

Graphical Flakes make O 2 : Self-supported ultrathin CoNiB nanoflakes are prepared by a simple one-step solid-state boronation. The unique sheet-like structure, bimetallic boride components, and optimal hybrid crystalline nature enable a synergistic promotion for the catalysis of the oxygen evolution reaction with long-term stability. The development of highly active and efficient nonprecious-metal electrocatalysts for the oxygen evolution reaction is important for the design of renewable energy production and storage devices. In this work, highly dense, ultrathin Co–Ni boride nanoflakes supported on a 3 D CoNi skeleton are fabricated in situ by a simple one-step, high-temperature, solid-state boronation process. As a result of the induced high electroactive surface area and low charge transfer resistance, CoNiB-700 exhibits high catalytic activity at an overpotential of 262 ( η 10 ) and 284 mV ( η 20 ) to deliver current densities of 10 and 20 mA cm −2 , respectively, with a Tafel slope of 58 mV dec −1 in an alkaline medium towards the oxygen evolution reaction. DFT calculations show that the Ni-regulated Co–B compound has a lower rate-determining energy barrier for the *OOH intermediate than the mono-Co–B compound, which facilitates the production of more active catalytic sites for an accelerated surface charge-transfer process for the oxygen evolution reaction.

Influence of magnetic field on morphological structures and physiological characteristics of bEnd.3 cells cultured on polypyrrole substrates

Xue Yang,Ke Ma,Libo Yang,Yujuan Chen,Yingmin Qu,Ying Wang,Xinyue Wang,Fan Yang,Qi Sun,Zhengxun Song,Zuobin Wang

This paper employs a spin-coated method to construct conductive polypyrrole (PPy) substrates which present superior properties for controlling the morphological structures and functions of bEnd.3 cells. The PPy substrates with a homogeneous particle size, uniform distribution and proper roughness show enhanced hydrophilic characteristics and improve cell adhesion to the substrates. The changes in the mechanical properties of cells and the responses to the designed substrates and magnetic field are also explored. Due to the synergistic effect between the magnetic field and the conductive PPy substrate, the cells cultured in such an environment exhibit applanate shapes with more branches and enhanced cell viability. In addition, the cells preferentially extend along the magnetic field direction. The mechanical characteristics of cells change significantly under varying magnetic intensity stimulations (5–16 mT). The satisfying effect on cells' morphology and outgrowth is acquired at the magnetic intensities of 9–10 mT and duration of 20 min, compared with other stimulated groups, while retaining cell viability. Moreover, the cells express higher adhesion up to 5.2 nN. The results suggest that the application of the PPy substrates and magnetic field is a promising candidate for the protection of neurovascular units and treatment of neurological diseases.

Well-defined 3-Aminopropyltriethoxysilane functionalized magnetite nanoparticles and their adsorption performance for partially hydrolyzed polyacrylamide from aqueous solution

Bowen Zhang,Yufei Wang,Jiao Zhang,Sanyuan Qiao,Zhenzhong Fan,Jiaqi Wan,Kezheng Chen

The application of magnetite (Fe 3 O 4 ) nanoparticles (MNPs) as adsorbent materials in solving wastewater treatment problems has attracted increasing attention. In this work, well-defined 3-Aminopropyltriethoxysilane (APTES) functionalized MNPs (APTES-MNPs) were synthesized by two-step method, in which a simple and scalable polyol method was used to initially synthesize MNPs with relatively large sizes and provide a defect site enriched surface to enable the APTES to coat on Fe 3 O 4 uniformly without using SiO 2 coating. The structure, morphology and properties of the APTES-MNPs were studied by TEM, XRD, FTIR, XPS and MPMS. The APTES-MNPs showed enhanced adsorption capacity towards HPAM due to the presence of high density of amino groups on the surface. Kinetics study revealed that the adsorption process followed the pseudo-second-order model, whereas the equilibrium isotherm data matched well with the Langmuir model. The APTES-MNPs could be rapidly separated from aqueous solution under magnetic field and be repeatedly used up to three cycles without significant loss of adsorption capacity. This new type of APTES-MNPs is expected to be a promising candidate for HPAM removal from aqueous solution.

Influence of Gd+3 incorporation on ethanol sensing properties of Barium Stannate microrod films prepared by coprecipitation method

Anish Bhattacharya,Xiangfeng Chu,Qi Gao,Xue Li,Yongping Dong,Shiming Liang,Amit K. Chakraborty

Ethanol sensing is an important area of research given its relevance to human health, traffic control and various industries. Metal oxide semiconductor nanostructures are most commonly used as gas sensors. In this study, enhanced ethanol sensing properties were obtained by incorporation of Gd 3+ ions into Barium Stannate (GBSO), a bimetallic oxide microrods prepared through a simple co-precipitation method. The GBSO films, when exposed to ethanol, showed that incorporation of Gd improved the sensing response till 3 wt% of Gd (3GBSO) loading while further increase in Gd content resulted in reduced response. 3GBSO sample showed response as high as 76 to 500 ppm of ethanol vapor at an operating temperature of 220 °C along with a very low detection limit of 0.1 ppm (response of 1.5). Good repeatability and moderate stability were also observed suggesting its potential as low-cost ethanol sensor. Significant increase in both specific surface area as well as oxygen content (as measured by x-ray photoelectron spectroscopy) was observed in 3GBSO sample compared to that of BSO. Thus, we showed that incorporation of Gd improved the surface area of BSO microrods and in turn the surface adsorption of oxygen which led to their enhanced response to ethanol.

A novel electrochemical biosensor based on dual signal amplification of CMK-3@AuNPs and ATRP for DR1 detection

Fuchun Si,Xiaojing Cui,Yaping Zhang,Yifan Li,Huaixia Yang,Yanju Liu

Down-regulator of transcription 1 (DR1) is a crucial biomarker closely related to Hashimoto's Thyroiditis (HT). In this study, a highly selective electrochemical biosensor for ultrasensitive detection of DR1 was prepared by combining nanomaterials CMK-3 @AuNPs and atom transfer radical polymerization (ATRP) signal amplification strategy for the first time. Based on the specific recognition of antigen and antibody, the sensor has strong selectivity. CMK-3 @AuNPs can not only increase the conductivity of the electrode, but also provide more active sites for biological molecules, so as to effectively amplify the output signal. The FMMA monomers were polymerized on the electrode surface through ATRP reaction, which made the electrochemical signal increased significantly. Under optimal conditions, the fabricated electrochemical biosensor showed a wide detection range of 5 × 10 -4 ng/mL ∼ 5 × 10 2 ng/mL with a detection limit as low as 0.159 pg/mL. In addition, the electrochemical biosensor has good stability and anti-interference ability. Therefore, the sensor has broad prospects in the detection of biomarkers.

Synthesis of natural 3′-Prenylchalconaringenin and biological evaluation of ameliorating non-alcoholic fatty liver disease and metabolic syndrome

Mengdi Zhang,Zhaoxin Wang,Siyu Hao,Lei Hao,Xinying Zhang,Peng Yu,Hua Sun

Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease and important risk factor for cardiac diseases, diabetes and extrahepatic cancers. Natural 3′-geranylchalconaringenin (GC) and desmethylxanthohumol (DX) from hop were synthesized using a regio-selective iodination and the Suzuki coupling reaction as key steps. GC and DX, along with their aglycone naringenin chalcone (NC) were investigated their decreasing the accumulation of cellular lipids . GC reduced lipid content and activated the AMP-activated protein kinase (AMPK) pathway in HepG2 and 3T3-L1 cells. In addition, GC had an obvious therapeutic effect on alleviating NAFLD and metabolic syndrome by activating the AMPK pathway in vivo . In conclusion, GC may be potentially used as a candidate drug and functional food for treating NAFLD and metabolic syndrome.

Developmental cardiotoxicity of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) in marine medaka (Oryzias melastigma)

Mengyuan Liu,Jing Li,Jiali Li,Bingsheng Zhou,Paul K.S. Lam,Chenyan Hu,Lianguo Chen

The application of 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one (DCOIT) as an antifouling biocide causes high toxicity to non-target marine organisms. To examine the developmental cardiotoxicity and mechanisms of DCOIT, we concurrently performed sub-chronic exposure and life-cycle exposure experiments using marine medaka embryos. After sub-chronic exposure to DCOIT at 1, 3, 10, and 33 μg/L, cardiac defects were caused by upregulation of cardiac gene transcriptions, decreasing heart size, and accelerating heartbeat. Hyperthyroidism in medaka larvae was identified as the cause of developmental cardiotoxicity of DCOIT sub-chronic exposure. In addition, parental life-cycle exposure to 1, 3, and 10 μg/L DCOIT led to transgenerational impairment of cardiogenesis in offspring medaka. A crossbreeding strategy discriminated a concentration-dependent mechanism of transgenerational cardiotoxicity. At 1 μg/L, the DCOIT-exposed female parent transferred a significantly higher amount of triiodothyronine (T3) hormone to offspring, corresponding to an accelerated heart rate. However, DCOIT at higher exposure concentrations modified the methylome imprinting in larval offspring, which was associated with cardiac dysfunction. Overall, the findings provide novel insights into the developmental cardiotoxicity of DCOIT. The high risks of DCOIT—even at environmentally realistic concentrations—raise concerns about its applicability as an antifoulant in a marine environment.