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High-performance, thin-film mixed-matrix membranes (MMMs) on a porous support have been developed, using zeolitic imidazole framework (ZIF) decorated graphene oxide (GO) as a filler, dispersed in a...

Programmed alloying within a van der Waals (vdW) semiconductor monolayer (ML) is achieved by metalorganic vapor-phase epitaxy. Specifically, two versions of on-ML alloying are demonstrated by preci...

The pseudocapacitors based on metal–organic frameworks (MOFs) are one of the state-of-the-art candidates to improve the future energy storage systems because of their high porosity, diverse functional groups, and potential as the template. In this study, the direct growth of a urea-assisted hierarchically layered cobalt-based MOF (u-hl-MOF) on Ni foam and direct growth of nanorods and nanosheets on the surface of the u-hl-MOF via the MOF-mediated approach without the addition of a cobalt precursor are reported. After the annealing process with sulfur powder under an Ar flow is complete, only the surface of the u-hl-MOF is converted into cobalt sulfide@carbon (Co1–xS@C), whereas the bulk internal u-hl-MOF remains without any degradation. Therefore, a core–shell structure of u-hl-MOF@Co1–xS@C (u-hl-MSC) is formed, which exhibits a high areal specific capacitance of 13.1 F cm–2 with a three-electrode system. A solid-state flexible asymmetric supercapacitor (ASC) is also assembled using poly(vinyl alcohol)/KO...

Structural coloration is promising as an alternative to chemical coloration because it has characteristics of their high color brightness, no fading, and low toxicity. Here, we report a pragmatic micromolding technique to create functional photonic microcylinders which are useful as structural color pigments. Photocurable dispersions of silica particles with interparticle repulsion are molded to spontaneously form regular arrays in confined volumes, which are instantly stabilized by photopolymerization. The resulting photonic microcylinders, released from the mold, exhibit pronounced structural colors from the entire visible range. In addition, multiple compartments can be integrated into single microcylinders through volatile-solvent-mediated sequential molding. As each compartment can be independently rendered to be structurally colored, transparent, or magneto-responsive, the multicompartment microcylinders show advanced functionalities, such as color-brightness tunability and switchable color properti...

A simple and flexible strategy for controlled synthesis of mesoporous metal oxide films using an amphiphilic graft copolymer as sacrificial template is presented and the effectiveness of this approach for gas-sensing applications is reported. The amphiphilic graft copolymer poly(vinyl chloride)-g-poly(oxyethylene methacrylate) (PVC-g-POEM) is used as a sacrificial template for the direct synthesis of mesoporous SnO2. The graft copolymer self-assembly is shown to enable good control over the morphology of the resulting SnO2 layer. Using this approach, mesoporous SnO2 based sensors with varied porosity are fabricated in situ on a microheater platform. This method reduces the interfacial contact resistance between the chemically sensitive materials and the microheater, while a simple fabrication process is provided. The sensors show significantly different gas-sensing performances depending on the SnO2 porosity, with the highly mesoporous SnO2 sensor exhibiting high sensitivity, low detection limit, and fast...

Recently, the WO3/BiVO4 heterojunction has shown promising photoelectrochemical (PEC) water splitting activity based on its charge transfer and light absorption capability, and notable enhancement of the photocurrent has been achieved via morphological modification of WO3. We developed a graft copolymer-assisted protocol for the synthesis of WO3 mesoporous thin films on a transparent conducting electrode, wherein the particle size, particle shape, and thickness of the WO3 layer were controlled by tuning the interactions in the polymer/sol–gel hybrid. The PEC performance of the WO3 mesoporous photoanodes with various morphologies and the individual heterojunctions with BiVO4 (WO3/BiVO4) were characterized by measuring the photocurrents in the absence/presence of hole scavengers using light absorption spectroscopy and intensity-modulated photocurrent spectroscopy. The morphology of the WO3 photoanode directly influenced the charge separation efficiency within the WO3 layer and concomitant charge collection ...

The control of the thickness and porosity of a mesoporous TiO2 layer is important to improve the photovoltaic performance of perovskite solar cells. We produced organized mesoporous TiO2 (om-TiO2) layers using a low-cost amphiphilic graft copolymer, poly(vinyl chloride)-graft-poly(oxyethylene methacrylate) (PVC-g-POEM), as a sacrificial template. This simple but effective synthetic approach generates highly mesoporous and well-organized TiO2 nanostructures with interconnected and size-tunable features. Specifically, the average pore size increased with the amount of hydrophobic PVC main chain in the graft copolymer, which acted as the pore forming agent. Perovskite layers were prepared on top of an om-TiO2 layer according to a two-step sequential deposition: after coating the PbI2 solution in dimethylformamide (DMF) on an om-TiO2 substrate, the substrate was prewetted in isopropyl alcohol (IPA) solvent before immersing into a CH3NH3I/IPA solution. This prewetting treatment not only improves the yields of ...

Polymeric microparticles with complex shapes have attracted substantial attention in many application areas because particle shape is a critical parameter to impart programmable functionalities. The formation of specific three-dimensional (3D) microstructures in a simple, scalable, and controllable manner is difficult. Here, we report the controlled fabrication of microparticles with complex 3D shapes based on the simple tuning of mold swelling and capillarity. Specifically, a photocurable solution loaded in micromolds is spatially deformed into complex shapes depending on the degree of molding swelling and capillarity, thereby producing polymeric microparticles with controlled 3D shapes upon photopolymerization. The results show that highly uniform microparticles with controlled two-dimensional (2D) and 3D shapes were fabricated from identical 2D micromolds via the simple tuning of the wetting fluids. This technique can be extended to produce highly complex microarchitectures with controlled 3D geometric domains via 2D mold designs. Finally, multicompartment microparticles with independently controlled 3D shapes for each compartment are produced by a simple combination of fabrication sequences. We envision that this strategy of producing 3D microarchitectures from easily designed simple micromolds could provide a path to new materials and new properties.

We report a one-step process for the synthesis and deposition of anatase, two-dimensional (2D), disk-shaped TiO2 (DS-TiO2) using titanium isopropoxide (TTIP), ethyl cellulose (EC), and solvents. The planar structure of EC plays a pivotal role as the sacrificing template to generate the 2D disk-shaped structure with a thickness of 1.5–3.5 μm, while a disk-like structure was well developed in the tetrahydrofuran (THF)/toluene mixed solvent. The quasi-solid-state dye-sensitized solar cells (qssDSSCs), fabricated with a nanogel electrolyte and a DS-TiO2 layer on a nanocrystalline (NC)-TiO2 photoanode, showed an energy conversion efficiency of 5.0% without any TiCl4 post-treatment, which is higher than that fabricated without DS-TiO2 (4.2%). When utilizing a poly((1-(4-ethenylphenyl)methyl)-3-butyl-imidazolium iodide) (PEBII) as the solid electrolyte, a high efficiency of 6.6% was achieved due to the combination of high mobility PEBII and a bifunctional DS-TiO2 layer with a 2D structure and anatase phase. The ...

We present a facile and inexpensive approach without any fluorinated chemistry to create superhydrophobic surface with exceptional liquid repellency, transportation of oil, selective capture of oil, optical bar code, and self-cleaning. Here we show experimentally that the control of evaporation is important and can be used to form superhydrophobic surface driven by Marangoni instability: the method involves in-situ photopolymerization in the presence of a volatile solvent and porous PDMS cover to afford superhydrophobic surfaces with the desired combination of micro- and nanoscale roughness. The porous PDMS cover significantly affects Marangoni convection of coating fluid, inducing composition gradients at the same time. In addition, the change of concentration of ethanol is able to produce versatile surfaces from hydrophilic to superhydrophobic and as a consequence to determine contact angles as well as roughness factors. In conclusion, the control of evaporation under the polymerization provides a convenient parameter to fabricate the superhydrophobic surface, without application of fluorinated chemistry and the elegant nanofabrication technique.

We present a surfactant-free fabrication method for simultaneous generation of monodisperse microspheres with controllable size manner. Droplets that become microspheres by solidification processes are made in a two-step process: capillary rising-induced fluid division and wetting of immiscible fluid in a micromold. Design of the mold geometry and the monomer concentration primarily determines the microsphere size and the size distribution. Furthermore, the synergistic effect of two parameters is able to efficiently manipulate the microsphere sizes from submicrometers to a few hundred micrometers.

The direct synthesis of hydrogen peroxide (DSHP) from H2 and O2 is conceptually the most ideal and straightforward reaction for producing H2O2 in industry. However, precisely tailored catalysts are...

In previous proteomic studies, heat shock protein β 1 (HSPB1) was detected as a candidate protein related to meat quality in cattle. This study sought to determine if its gene expression was associated with intramuscular fat content in the longissimus thoracis muscle of Korean cattle (Hanwoo). Tissue from two groups of 10 steers each, low-marbling (mean intramuscular fat content, 7.4 ± 1.5%) and high-marbling (23.5 ± 2.8%), were used for immunoblotting, real-time PCR, and statistical analyses. HSPB1 expression in both mRNA and protein was shown to be negatively related to intramuscular fat content (P < 0.05). Pathway analysis found two genes, TNF receptor superfamily member 6 (FAS) and angiotensinogen (AGT), that were regulators of the HSPB1 gene. The expression of the two genes showed a negative correlation with intramuscular fat content (P < 0.05). These results suggest that HSPB1, FAS, and AGT may be good candidate genes associated with intramuscular fat content in the longissimus muscle of Korean cattle.

We identify and investigate several critical parameters in the fabrication of single-stranded DNA conjugated poly(ethylene glycol) (PEG) microparticles based on replica molding (RM) for highly uniform and robust nucleic acid hybridization assays. The effects of PEG-diacrylate, probe DNA, and photoinitiator concentrations on the overall fluorescence and target DNA penetration depth upon hybridization are examined. Fluorescence and confocal microscopy results illustrate high conjugation capacity of the probe and target DNA, femtomole sensitivity, and sequence specificity. Combined, these findings demonstrate a significant step toward simple, robust, and scalable procedures to manufacture highly uniform and high-capacity hybridization assay particles in a well-controlled manner by exploiting many advantages that the batch processing-based RM technique offers. We envision that the results presented here may be readily applied to rapid and high-throughput hybridization assays for a wide variety of applications in bioprocess monitoring, food safety, and biological threat detection.

Inhibition of acyl CoA:diacylglycerol acyltransferase (DGAT), which is a key enzyme in triglyceride synthesis in eukaryotic organisms, has been proposed as one of the drug targets for treating obesity, type II diabetes mellitus, and metabolic syndrome. Bioassay-guided fractionation of EtOH extract of the flower buds of Tussilago farfara , using an in vitro DGAT enzyme assay, resulted in the isolation of four known sesquiterpenoids, tussilagonone (1), tussilagone (2), 7beta-(3-ethyl-cis-crotonoyloxy)-1alpha-(2-methylbutyryloxy)-3,14-dehydro-Z-notonipetranone (3), and 8-angeloylxy-3,4-epoxy-bisabola-7(14),10-dien-2-one (4). DGAT1 inhibitory activity was studied by in vitro DGAT assay using rat liver microsomes and HepG2 cell microsomes. They showed DGAT1 inhibition with IC(50) values of 99.2 (1), 18.8 (2), 47.0 (3), and 211.1 (4) microM (for rat liver microsomes) and >1 mM (1), 49.1 (2), 160.7 (3), and 294.4 (4) microM (for HepG2 cell microsomes), respectively. Compound 2 showed the most potent inhibition against microsomal DGAT1 derived from rat liver and human hepatocellular carcinoma HepG2 cells and also significantly inhibited triglyceride synthesis by suppressing incorporation of [(14)C]acetate or [(14)C]glycerol into triglycerides in HepG2 cells. These findings suggest that tussilagone is a potential lead compound in the treatment of obesity and type 2 diabetes.

Exposing single-walled carbon nanotubes to room-temperature UV-generated ozone leads to an irreversible increase in their electrical resistance. We demonstrate that the increased resistance is due to ozone oxidation on the sidewalls of the nanotubes rather than at the end caps. Raman and X-ray photoelectron spectroscopies show an increase in the defect density due to the oxidation of the nanotubes. Using ultraviolet photoelectron spectroscopy, we show that these defects represent the removal of pi-conjugated electron states near the Fermi level, leading to the observed increase in electrical resistance. Oxidation of carbon nanotubes is an important first step in many chemical functionalization processes. Because the oxidation rate can be controlled with short exposures, UV-generated ozone offers the potential for use as a low-thermal-budget processing tool.

We demonstrate the electrically addressable biomolecular functionalization of single-walled carbon nanotube electrodes and vertically aligned carbon nanofiber electrodes. The method uses an electrochemical reaction in which nitro groups on specific nanostructures are reduced to amino groups and then used to covalently link DNA to only these nanostructures. We demonstrate fabrication of a four-element array of distinct DNA oligonucleotides on carbon nanotube electrodes and the addressable functionalization of submicron bundles of

A series of (E)-5-(2-bromovinyl)uracil analogues and related nucleosides was synthesized, and their antiviral activities were evaluated. (E)-5-(2-Bromovinyl)-2'-deoxy-L-uridine (L-BVDU, 2), 1-(beta-L-arabinofuranosyl)-(E)-5-(2-bromovinyl)uracil (L-BVAU, 4), (E)-5-(2-bromovinyl)-1-(2-deoxy-2-fluoro-beta-L-ribofuranosyl)uracil (L-FBVRU, 8) and (E)-5-(2-bromovinyl)-1-(2-deoxy-2-fluoro-beta-L-arabinofuranosyl)urac il (L-FBVAU, 10) were synthesized via appropriate 5-iodouracil analogues from L-arabinose. D- and L-Oxathiolane and -dioxolane derivatives 13, 16, 20, 21, and 29-34 were prepared by glycosylation reaction of the oxathiolane and dioxolane intermediates with silylated uracil analogues using TMSI as the coupling agent. The synthesized compounds were evaluated in cell cultures infected with the following viruses: varicella zoster virus (VZV), Epstein Barr virus (EBV), and herpes simplex virus types 1 and 2 (HSV-1 and HSV-2). Among the tested compounds, beta-L-CV-OddU (29), beta-L-BV-OddU (31), and beta-L-IV-OddU (33) exhibited potent in vitro antiviral activity against VZV with EC(50) values of 0.15, 0. 07, and 0.035 microM, respectively, and against EBV with EC(50) values of 0.49, 0.59, and 3.91 microM, respectively.

Electrically addressable biomolecular functionalization of diamond thin films is achieved by growing a conductive diamond thin film on molybdenum electrodes, functionalizing to produce surface nitro groups, and electrochemically reducing the nitro groups on specific diamond-coated electrodes to primary amines. The amines are then used to covalently link DNA to the surface.

exo-2-Chloro- and 7-chloronorbornane in the presence of tin(IV) chloride or aluminium chloride react with benzene and substituted benzenes to give the corresponding norbornylated products. Mechanistic aspects of the reactions proceeding through carbocationic intermediates are discussed