Ultrafast Room-Temperature Synthesis of Self-Supported NiFe-Layered Double Hydroxide as Large-Current-Density Oxygen Evolution Electrocatalyst.

Water splitting is a promising sustainable technology to produce high purity hydrogen, but its commercial application remains a giant challenge due to the kinetically sluggish oxygen evolution reaction (OER). In this work, a time- and energy-saving approach to directly grow NiFe-layered double hydroxide (NiFe-LDH) nanosheets on nickel foam under ambient temperature and pressure is reported. These NiFe-LDH nanosheets are vertically rooted in nickel foam and interdigitated together to form a highly porous array, leading to numerous exposed active sites, reduced resistance of charge/mass transportation and enhanced mechanical stability. As self-supported electrocatalyst, the representative sample (NF@NiFe-LDH-1.5-4) shows an excellent large-current-density catalytic activity for OER in alkaline electrolyte, requiring low overpotentials of 190 and 220 mV to reach the current densities of 100 and 657 mA cm-2 with a Tafel slope of 38.1 mV dec-1 . In addition, NF@NiFe-LDH-1.5-4 as an overall water splitting electrocatalyst can stably achieve a large current density of 200 mA cm-2 over 300 h at a low cell voltage of 1.83 V, meeting the requirement of industrial hydrogen production. This exceedingly simple and ultrafast synthesis of low-cost and highly active large-current-density OER electrocatalysts can propel the commercialization of hydrogen producing technology via water splitting.

Encapsulation of Fe nanoparticles into an N-doped carbon nanotube/nanosheet integrated hierarchical architecture as an efficient and ultrastable electrocatalyst for the oxygen reduction reaction.

The exploration of cost-effective, highly efficient and robust electrocatalysts toward the oxygen reduction reaction (ORR) is of paramount significance for the advancement of future renewable energy conversion devices, and yet still remains a great challenge. Herein, we demonstrate a straightforward one-step pyrolysis strategy for the scalable synthesis of an iron-nitrogen-carbon hierarchically nanostructured catalyst, in which Fe-based nanoparticles are encapsulated in bamboo-like N-doped carbon nanotubes in situ rooted from porous N-doped carbon nanosheets (Fe@N-C NT/NSs). The delicate fabrication of such an 0D/1D/2D integrated hierarchical architecture with encased Fe species and open configuration renders the formed Fe@N-C NT/NSs with sufficient confined active sites, reduced charge transfer resistance, improved diffusion kinetics and outstanding mechanical strength. As such, compared with commercial Pt/C, the optimized Fe@N-C NT/NSs catalyst exhibits efficient ORR activity, superior durability and strong tolerance to methanol in KOH medium. More impressively, when assembled as a cathode catalyst in a microbial fuel cell, the Fe@N-C NT/NSs electrode displays significantly enhanced power density and output voltage in comparison with commercial Pt/C, holding great promise in practical energy conversion devices. What's more, the simple yet reliable synthesis strategy developed here may shed light on the future design of advanced high-efficiency hierarchical architectures for diverse electrochemical applications and beyond.

A hybrid YSZ/SnO2/MEMS SO2 gas sensor.

This study uses a solid YSZ electrolyte film in a SnO2 MEMS SO2 gas sensor of the semiconductor type to enhance the redox reaction. The YSZ film is prepared by RF sputtering. XRD analysis shows the presence of the (111), (200), (220) and (311) peaks that denote the crystallization planes of YSZ. The experimental results show that the SnO2 MEMS SO2 gas sensor with a YSZ film has a better sensor response than a pure SnO2 MEMS SO2 gas sensor or a YSZ MEMS SO2 gas sensor when the SO2 concentration and the sensor's temperature sensors are 250 ppb and 400 °C, respectively. The YSZ/SnO2 sensor's measured responses are around 6%, 45%, 20% and 16% when the sensor is respectively operated at 250 °C, 300 °C, 350 °C, and 400 °C.

Discovery of Small-Molecule Antagonists of the H3K9me3 Binding to UHRF1 Tandem Tudor Domain.

Ubiquitin-like with PHD and RING finger domains 1 (UHRF1) is a multidomain protein that plays a critical role in maintaining DNA methylation patterns through concurrent recognition of hemimethylated DNA and histone marks by various domains, and recruitment of DNA methyltransferase 1 (DNMT1). UHRF1 is overexpressed in various cancers, including breast cancer. The tandem tudor domain (TTD) of UHRF1 specifically and tightly binds to histone H3 di- or trimethylated at lysine 9 (H3K9me2 or H3K9me3, respectively), and this binding is essential for UHRF1 function. We developed an H3K9me3 peptide displacement assay, which was used to screen a library of 44,000 compounds for small molecules that disrupt the UHRF1-H3K9me3 interaction. This screen resulted in the identification of NV01, which bound to UHRF1-TTD with a Kd value of 5 µM. The structure of UHRF1-TTD in complex with NV01 confirmed binding to the H3K9me3-binding pocket. Limited structure-based optimization of NV01 led to the discovery of NV03 (Kd of 2.4 µM). These well-characterized small-molecule antagonists of the UHRF1-H3K9me2/3 interaction could be valuable starting chemical matter for developing more potent and cell-active probes toward further characterizing UHRF1 function, with possible applications as anticancer therapeutics.

A high-performance asymmetric supercapacitor based on vanadyl phosphate/carbon nanocomposites and polypyrrole-derived carbon nanowires.

A novel asymmetric supercapacitor device in an aqueous electrolyte is fabricated using a vanadyl phosphate/carbon nanocomposite as the positive electrode and a polypyrrole-derived carbon nanowire as the negative electrode. The vanadyl phosphate/carbon nanocomposites are synthesized by a simple two-step approach in which layered VOPO4·2H2O is first intercalated by dodecylamine and then annealed at high temperature, leading to the in situ carbonization of the intercalated dodecylamine. It is found that the sample in which the incorporated carbon with a high degree of graphitization exhibits a high specific capacitance of 469 F g-1 at a current density of 1 A g-1 and excellent rate performance (retained 77% capacitance at 10 A g-1). A polypyrrole-derived carbon nanowire is synthesized by the direct carbonization of nanowire-shaped polypyrrole, revealing a rough surface of nanowire-like frameworks and good electrochemical behavior. Taking advantage of both positive and negative materials, the assembled asymmetric supercapacitor device exhibits a high energy density of 30.6 W h kg-1 at a high power density of 813 W kg-1 in a wide voltage region of 0-1.6 V, as well as a good electrochemical stability (84.3% capacitance retention after 5000 cycles). The present work can shed light on the fabrication of novel asymmetric supercapacitors with high-performance.

Through-silicon via submount for the CuO/Cu2O nanostructured field emission display.

A three dimensional (3D) field emission display structure was prepared using CuO/Cu2O composite nanowires (NWs) and a three dimensional through silicon via (3D-TSV) technique. The experimental results indicated that the diameter and length of the Si via were about 100 µm and 200 µm, respectively. For the 3D field emission structure, high-density CuO/Cu2O composite nanowires (NWs) were grown on the concave TSV structure using thermal oxidation. The field emission turn-on field and enhancement factor of the CuO/Cu2O composite NWs were 15 V µm-1 and ∼1748, respectively. With regard to field emission displays, we successfully used the 3D field emission structure to excite the orange phosphors.

Regioselective Bromination of Thieno[2',3':4,5]pyrrolo[1,2-d][1,2,4]triazin-8(7H)-one and Sequential Suzuki Couplings.

Regioselective bromination of thieno[2',3':4,5]pyrrolo[1,2-d][1,2,4]triazin-8(7H)-one at the 2- or 9-position was achieved by modulating the basicity of the reaction conditions. An anion-directed site-specific bromination mechanism was proposed. In addition, a one-pot bromination-Suzuki coupling protocol was developed for quick access of analogues at the 9-position.

Effects of breviscapine on amyloid beta 1-42 induced Alzheimer's disease mice: A HPLC-QTOF-MS based plasma metabonomics study.

Herba Erigerontis has long been used to cure apoplexy hemiplegia and precordial pain in China. In addition, the bioactivities of its total flavonoids-breviscapine included inhibiting amyloid beta (Aß) fibril formation, antioxidation and metal chelating, which are beneficial to treat Alzheimer's disease (AD). Hence, A HPLC-QTOF-MS based plasma metabonomics approach was applied to investigate the neuroprotective effects of breviscapine on intracerebroventricular injection of aggregated Aß 1-42 induced AD mice for the first time in the study. Ten potential biomarkers were screened out by multivariate statistical analysis, eight of which were further identified as indoleacrylic acid, C16 sphinganine, LPE (22:6), sulfolithocholic acid, LPC (16:0), PA (22:1/0:0), taurodeoxycholic acid, and PC (0:0/18:0). According to their metabolic pathways, it was supposed that breviscapine ameliorated the learning and memory deficits of AD mice predominantly by regulating phospholipids metabolism, elevating serotonin level and lowering cholesterols content in vivo.

Isolation, purification, and identification of the main phenolic compounds from leaves of celery (Apium graveolens L. var. dulce Mill./Pers.).

We developed a simple and meaningful preparative method for the separation and purification of the main phenolic compounds from the leaves of celery (Apium graveolens L. var. dulce Mill./Pers.) and we established an accurate and specific analytical method for the identification of the main phenolic compounds from celery leaves. The crude extract from celery leaves was prefractioned by polyamide resin to enrich the phenolic compounds. They were then purified further by preparative high-performance liquid chromatography, and seven main phenolic compounds were obtained: including chlorogenic acid, luteolin 7-O-ß-d-apiofuranosyl(1→2)-ß-d-glucopyranoside, luteolin 7-O-ß-d-glucopyranoside, apiin, chrysoeriol 7-O-ß-d-apiofuranosyl(1→2)-ß-d-glucopyranoside, luteolin 7-O-[ß-d-apiofuranosyl(1→2)-(6''-O-malonyl)]-ß-d-glucopyranoside, and apigenin 7-O-[ß-d-apiofuranosyl(1→2)-(6''-O-malonyl)]-ß-d-glucopyranoside. Their purities were measured by using high-performance liquid chromatography, and their chemical structures were confirmed using UV spectrophotometry, ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry, and NMR spectroscopy. Our studies indicate that preparative high-performance liquid chromatography combined with polyamide resin is a simple and meaningful preparative method for the separation and purification of phenolic compounds from the leaves of celery or other plants, and the use of UV spectrophotometry, ultra high performance liquid chromatography with quadrupole time-of-flight tandem mass spectrometry, and NMR spectroscopy is an accurate and specific analytical method for the identification of phenolic compounds.

A novel approach for sulfur-doped hierarchically porous carbon with excellent capacitance for electrochemical energy storage.

A novel approach for hierarchically porous S-doped carbon was developed. Owing to the obviously reduced particle size and greatly enhanced meso-/macropores, electronic conductivity and surface polarity as well as the active sites available for Faradaic reactions, the resultant S-doped carbon electrode shows an excellent supercapacitor performance.

Dissipation kinetics, safety evaluation, and preharvest interval assessment of trichlorfon application on rice.

Nowadays, there is an urgent need for the investigation of the field dissipation and assessment of the preharvest interval for trichlorfon residues on rice. To protect consumers from potential health risks, this study can provide references for the safe application of trichlorfon in the rice fields. Results of the field dissipation study showed that the dissipation dynamic equations of trichlorfon were based on the first-order reaction dynamic equations and that the dissipation rates vary among rice plant, brown rice, rice bran, soil, and water. The 2-year field trials conducted in Yangzhou and Xiaogan suggested the interval of each application for trichlorfon on rice to be at least 7 days when 80 % trichlorfon SP was sprayed with a dose ranges between 80 and 160 a.i g/667 m(2). Additionally, the preharvest interval of the last application should be at least 15 days to ensure the amounts of residues below the maximum residue limits of trichlorfon on brown rice (0.1 mg/kg).

Degradation kinetics and pathways of spirotetramat in different parts of spinach plant and in the soil.

Spirotetramat is a new pesticide against a broad spectrum of sucking insects and exhibits a unique property with a two-way systemicity. In order to formulate a scientific rationale for a reasonable spray dose and the safe interval period of 22.4 % spirotetramat suspension concentrate on controlling vegetable pests, we analyzed degradation dynamics and pathways of spirotetramat in different parts of spinach plant (leaf, stalk, and root) and in the soil. We conducted experimental trials under field conditions and adopted a simple and reliable method (dispersive solid phase extraction) combined with liquid chromatography-triple quadrupole tandem mass spectrometry to evaluate the dissipation rates of spirotetramat residue and its metabolites. The results showed that the spirotetramat was degraded into different metabolite residues in different parts of spinach plant (leaf, stalk, and root) and in the soil. Specifically, spirotetramat was degraded into B-keto, B-glu, and B-enol in the leaf; B-glu and B-enol in the stalk; and only B-enol in the root. In the soil where the plants grew, spirotetramat followed a completely different pathway compared to the plant and degraded into B-keto and B-mono. Regardless of different degradation pathways, the dissipation dynamic equations of spirotetramat in different parts of spinach plant and in the soil were all based on the first-order reaction dynamic equations. This work provides guidelines for the safe use of spirotetramat in spinach fields, which would help prevent potential health threats to consumers.

Instantaneous Directional Growth of Block Copolymer Nanowires During Heterogeneous Radical Polymerization (HRP).

Polymeric nanowires that consist of ultrahigh molecular weight block copolymers were instantaneously prepared via one-step surfactant-free heterogeneous radical polymerization (HRP). Under heterogeneous reaction and initiator-starvation conditions, the sequential copolymerization of hydrophilic and hydrophobic monomers facilitates the formation of amphiphilic ultrahigh molecular weight block copolymers, which instantaneously assemble to polymeric nanowires. As polymerization progresses, initially formed nanoparticles exhibit the directional growth due to localized repulsive forces of hydrophilic blocks and confinement of the hydrophobic blocks that adopt favorable high aspect ratio nanowire morphologies. Using one-step synthetic approach that requires only four ingredients (water as a solvent, two polymerizable monomers (one hydrophilic and one hydrophobic), and water-soluble initiator), block copolymer nanowires ∼70 nm in diameter and hundreds of microns in length are instantaneously grown. For example, when 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA) and styrene (St) were copolymerized, high aspect ratio nanowires consist of ultrahigh (>10(6) g/mol) molecular weight pDMAEMA-b-St block copolymers and the presence of temperature responsive pDMAEMA blocks facilitates nanowire diameter changes as a function of temperature. These morphologies may serve as structural components of the higher order biological constructs at micro and larger length scales, ranging from single strand nanowires to engineered biomolecular networks capable of responding to diverse and transient environmental signals, and capable of dimensional changes triggered by external stimuli.

Systematic identification of multiple tumor types in microarray data based on hybrid differential evolution algorithm.

Correct classification and prediction of tumor cells are essential for microarrays to construct a diagnostic system. Differential evolution (DE) is a powerful optimization algorithm, which has been widely used in many areas. However, the standard DE and most of its variants search in the continuous space, which cannot solve the binary optimizations directly. In this paper, the hybrid framework based on the binary DE algorithm and silhouette filter, is proposed to improve searching ability to classify breast and leukemia cancers in microarray for biomarker discovery. The study is focused to use hybrid DE algorithm for gene selection and silhouette statistics as a discriminant function to classify multiple tumor types in microarray data. Distance metrics on silhouette statistics have also been discussed for high classification accuracy. Experimental results show that the hybrid method is effective to discriminate breast and leukemia cancer subtypes and find potential biomarkers for cancer diagnosis.

Systematic identification of multiple tumor types in microarray data based on hybrid differential evolution algorithm.

Correct classification and prediction of tumor cells are essential for microarrays to construct a diagnostic system. Differential evolution (DE) is a powerful optimization algorithm, which has been widely used in many areas. However, the standard DE and most of its variants search in the continuous space, which cannot solve the binary optimizations directly. In this paper, the hybrid framework based on the binary DE algorithm and silhouette filter, is proposed to improve searching ability to classify breast and leukemia cancers in microarray for biomarker discovery. The study is focused to use hybrid DE algorithm for gene selection and silhouette statistics as a discriminant function to classify multiple tumor types in microarray data. Distance metrics on silhouette statistics have also been discussed for high classification accuracy. Experimental results show that the hybrid method is effective to discriminate breast and leukemia cancer subtypes and find potential biomarkers for cancer diagnosis.

Marine bacterial chemoresponse to a stepwise chemoattractant stimulus.

We found recently that polar flagellated marine bacterium Vibrio alginolyticus is capable of exhibiting taxis toward a chemical source in both forward and backward swimming directions. How the microorganism coordinates these two swimming intervals, however, is not known. The work presented herein is aimed at determining the response functions of the bacterium by applying a stepwise chemoattractant stimulus while it is swimming forward or backward. The important finding of our experiment is that the bacterium responds to an identical chemical signal similarly during the two swimming intervals. For weak stimuli, the difference is mainly in the amplitudes of the response functions while the reaction and adaptation times remain unchanged. In this linear-response regime, the amplitude in the forward swimming interval is approximately a factor of two greater than in the backward direction. Our observation suggests that the cell processes chemical signals identically in both swimming intervals, but the responses of the flagellar motor to the output of the chemotaxis network, the regulator CheY-P concentration, are different. The biological significance of this asymmetrical response in polar flagellated marine bacteria is discussed.

Rationally designed gibbous stimuli-responsive colloidal nanoparticles.

Multiphase colloidal copolymer nanoparticles, if properly designed, offer a number of unique properties and well-documented technological opportunities for drug delivery, nanolithography, high surface area colloidal crystals, or hollow nanoparticles, to name just a few. Using a simple free radical polymerization process, we synthesized copolymer nanoparticles with controlled stimuli-responsive phase-separated gibbosities. The topography of the gibbous phase can be controlled by the copolymer composition and polymerization conditions. When pH-sensitive monomers were copolymerized onto surface bulges, pH changes resulted in localized gibbous phase dimensional changes. Facilitated by monomer diffusion into interfacial particle seed solution regions, localized polymerization near the surface is responsible for the formation of phase-separated gibbous topographies. This general approach may offer a number of possibilities for controllable design of ordered heterogeneous copolymer morphologies for a variety of applications.

One-Step Synthesis of Amphiphilic Ultrahigh Molecular Weight Block Copolymers by Surfactant-Free Heterogeneous Radical Polymerization.

Ultrahigh molecular weight (>106 g/mol) amphiphilic block copolymers were synthesized using one-step surfactant-free heterogeneous radical polymerization (SFHRP). The polymerization initially involves formation of water-soluble homopolymer blocks, followed by copolymerization of a hydrophobic monomer, resulting in ultrahigh molecular weight block copolymers. Facilitating heterogeneous reaction conditions and continuous supply of an initiator controls the process. Using this synthetic approach, we synthesized amphiphilic block copolymers of poly(2-(N,N-dimethylamino)ethyl methacrylate)-block-poly(n-butyl acrylate) (pDMAEMA-b-pnBA), pDMAEMA-block-p(tert-butyl acrylate) (pDMAEMA-b-tBA), and pDMAEMA-block-polystyrene (pDMAEMA-b-pSt) with molecular weights of 1.98 × 106, 1.18 × 106, and 0.91 × 106 g/mol, respectively. These ultrahigh molecular weight block copolymers can self-assemble in nonpolar solvents to form thermochromic inverse polymeric micelles as well as other shapes and exhibit many potential applications.

Analysis of flavonoids and hydroxycinnamic acid derivatives in rapeseeds (Brassica napus L. var. napus) by HPLC-PDA--ESI(--)-MS(n)/HRMS.

A comprehensive description of flavonoids and hydroxycinnamic acid derivatives in Brassica napus L. var. napus seeds is important to improve rapeseed quality. HPLC-PDA-ESI(-)-MS(n)/HRMS has been broadly applied to study phenolic compounds in plants. In the present study, crude phenolic compounds extracted from rapeseed were subjected to column chromatography, alkaline hydrolysis, and HPLC-PDA-ESI(-)-MS(n)/HRMS analysis. A total of 91 flavonoids and hydroxycinnamic acid derivatives were detected, including 39 kaempferol derivatives, 11 isorhamnetin derivatives, 5 quercetin derivatives, 6 flavanols and their oligomers, and 30 hydroxycinnamic acid derivatives. A total of 78 of these compounds were tentatively identified; of these, 55 were reported for the first time in B. napus L. var. napus and 24 were detected for the first time in the genus Brassica. This research enriches our knowledge of the phenolic composition of rapeseed and provides a reliable guide for the selection of rapeseed with valuable breeding potential.

Tri-Phasic Size- and Janus Balance-Tunable Colloidal Nanoparticles (JNPs).

These studies show synthesis of triphasic size- and Janus balance (JB)-tunable nanoparticles (JNPs) utilizing a two-step emulsion polymerization of pentafluorostyrene (PFS) and 2-(dimethylamino)ethyl methacrylate (DMAEMA) and n-butyl acrylate (nBA) in the presence of poly(methyl methacrylate (MMA)/nBA) nanoparticle seeds. Each JNP consists of three phase-separated copolymers: p(MMA/nBA) core, temperature, and pH-responsive (p(DMAEMA/nBA)) phase capable of reversible size and shape changes, and shape-adoptable (p(PFS/nBA)) phase. Due to built-in second-order lower critical solution temperature (II-LCST) transition of p(DMAEMA/nBA) copolymer, macromolecular segments collapse when temperature increases from 30 to 45 °C, resulting in size and shape changes. The p(DMAEMA/nBA) and p(MMA/nBA) phases within each JNP assume concave, flat, or convex shapes, forcing p(PFS/nBA) phase to adopt convex, planar, or concave interfacial curvatures, respectively. As a result, the JB can be tuned from 3.78 to 0.72. The presence of pH-responsive DMAEMA component also facilitates the size and JB changes due to protonation of the tertiary amine groups of p(DMAEMA/nBA) backbone. Synthesized in this manner, JNPs are capable of stabilizing oil droplets in water at high pH to form Pickering emulsions, which at lower pH values release oil phase. This process is reversible and can be repeated many times.