Two-Dimensional Conjugated Metal-Organic Frameworks for Photochemical Transformations.

Photochemical transformation represents an attractive pathway for the conversion of earth-abundant resources, such as HO, CO, O, and N, into valuable chemicals by utilizing sunlight as an energy source. Recently, two-dimensional conjugated metal-organic frameworks (2D c-MOFs) have emerged as the focal points in the field of photo-to-chemical conversion due to their advantages in light harvesting, electrical conductivity, mass transport, tunable electronic and porous structures, as well as abundant active sites. In this review, we highlight various physical and chemical features of 2D c-MOFs that can contribute to enhanced photo-induced exciton generation, charge transport, proton migration and redox catalysis.

Laboratory demonstration of an off-axis optical bench design for future gravity missions.

The inter-satellite laser ranging interferometer is one of the core components of future gravity missions to achieve high ranging precision. This work builds a preliminary breadboard of the off-axis optical bench design, which integrates the merits of the off-axis optical bench design of GRACE Follow-On mission and other on-axis designs. The study finds that the displacement noise between two optical benches has been reduced to 20nm/Hz at a frequency of 10 mHz, and the differential wavefront sensing noise has been suppressed to 10-5rad/Hz at 1 kHz as well.

Interpretation and Prediction of the CO Sequestration of Steel Slag by Machine Learning.

The utilization of steel slag for CO sequestration is an effective way to reduce carbon emissions. The reactivity of steel slag in CO sequestration depends mainly on material and process parameters. However, there are many puzzles in regard to practical applications due to the different evaluations of process parameters and the lack of investigation of material parameters.

Bathymetry of a macro-pulsed chaotic laser based on a 520 nm laser diode subject to free space optical feedback.

We generate a macro-pulsed chaotic laser based on pulse-modulated laser diode subject to free space optical feedback, and demonstrate the performance of suppressing backscattering interference and jamming in turbid water. The macro-pulsed chaotic laser with a wavelength of 520 nm as a transmitter is used with a correlation-based lidar receiver to perform an underwater ranging. At the same power consumption, macro-pulsed lasers have higher peak power than in the continuous-wave form, enabling the former to detect longer ranging.

Studying an off-axis optical bench for future gravity missions from the perspective of carrier-to-noise ratio.

The inter-satellite laser ranging heterodyne interferometer is vital for future gravity missions to achieve high ranging accuracy. This paper proposes a novel off-axis optical bench design which integrates merits of the off-axis optical bench design of GRACE Follow-On mission and other on-axis designs. This design makes use of lens systems subtly to restrict the tilt-to-length coupling noise and takes advantage of the DWS feedback loop to maintain the transmitting beam and receiving beam anti-parallel.

Strain effect on the field-effect sensing property of Si wires.

Silicon-based field effect transistor (FET) sensors with high sensitivity are emerging as powerful sensors for detecting chemical/biological species. Strain engineering has been demonstrated as an effective means to improve the performance of Si-based devices. However, the strain effect on the field-effect sensing property of silicon materials has not been studied yet.

QM/MM and MM MD simulations on decontamination of the V-type nerve agent VX by phosphotriesterase: toward a comprehensive understanding of steroselectivity and activity.

Due to deadly toxicity and high environmental stability of the nerve agent VX, an efficient decontamination approach is desperately needed in tackling its severe threat to human security. The enzymatic destruction of nerve agents has been generally considered as one of the most effective ways, and here the hydrolysis of VX by phosphotriesterase (PTE) was investigated by extensive QM/MM and MM MD simulations. The hydrolytic cleavage of P-S by PTE is a two-step process with the free energy spans of 15.

Highly Cross-linked Epoxy Coating for Barring Organophosphate Chemical Warfare Agent Permeation.

Chemical warfare agents (CWAs) can be absorbed in polymeric coatings through absorption and permeation, thus presenting a lethal touch and vapor hazards to people. Developing a highly impermeable polymer coating against CWAs, especially against organophosphate CWAs (OPs), is challenging and desirable. Herein, fluorinated epoxy (F-EP) and epoxy (EP) coatings with different cross-link densities were prepared to resist OPs.

Ionic Carbazole-Based Water-Soluble Two-Photon Photoinitiator and the Fabrication of Biocompatible 3D Hydrogel Scaffold.

Two-photon polymerization of a three-dimensional (3D) hydrogel structure has been widely applied in biological tissue engineering. For improving the biocompatibility of hydrogel structures, a new kind of ionic carbazole water-soluble photoinitiator was prepared to realize the fabrication of a 3D hydrogel structure in aqueous phase. 3,6-Bis[2-(1-methyl-pyridinium)vinyl]-9-methyl-carbazole diiodide (BMVMC) and cucurbit[7]uril (CB7) have been employed to generate a complex with better water solubility by host-guest interactions.

Electrostatic Effect of Functional Surfaces on the Activity of Adsorbed Enzymes: Simulations and Experiments.

The efficient immobilization of haloalkane dehalogenase (DhaA) on carriers with retaining of its catalytic activity is essential for its application in environmental remediation. In this work, adsorption orientation and conformation of DhaA on different functional surfaces were investigated by computer simulations; meanwhile, the mechanism of varying the catalytic activity was also probed. The corresponding experiments were then carried out to verify the simulation results.

Chromo-Fluorogenic Detection of Soman and Its Simulant by Thiourea-Based Rhodamine Probe.

Here, we introduced a novel thiourea-based rhodamine compound as a chromo-fluorogenic indicator of nerve agent Soman and its simulant diethyl chlorophosphate (DCP). The synthesized probe N-(rhodamine B)-lactam-2-(4-cyanophenyl) thiourea (RB-CT), which has a rhodamine core linked by a cyanophenyl thiosemicarbazide group, enabled a rapidly and highly sensitive response to DCP with clear fluorescence and color changes. The detection limit was as low as 2 × 10 M.

Cucurbit[7]uril-Carbazole Two-Photon Photoinitiators for the Fabrication of Biocompatible Three-Dimensional Hydrogel Scaffolds by Laser Direct Writing in Aqueous Solutions.

We have introduced a novel water-soluble two-photon photoinitiator based on the host-guest interaction between 3,6-bis[2-(1-methyl-pyridinium)vinyl]-9-pentyl-carbazole diiodide (BMVPC) and cucurbit[7]uril (CB7) because most of the commercial photoinitiators have poor two-photon initiating efficiency in aqueous solutions. The binding ratio of BMVPC and CB7 was determined as 1:1 by isothermal titration calorimetry and quantum chemical calculation. The formation of the host-guest complex increases the two-photon absorption cross-section about five times, and improves the water solubility required as the photoinitiator for hydrogel fabrication.

Laser-Induced Antibacterial Activity of Novel Symmetric Carbazole-Based Ethynylpyridine Photosensitizers.

In this study, two kinds of novel carbazole-based ethynylpyridine salts: 3,6-bis[2-(1-methylpyridinium)ethynyl]-9-pentyl-carbazole diiodide (BMEPC) and 3,6-bis[2-(1-methylpyridinium)ethynyl]-9-methyl-carbazole diiodide (BMEMC) have been employed as photosensitizers owing to their excellent antibacterial activity. These molecules possess symmetric A-π-D-π-A-type structures, which would bring in the unique optical properties. The inhibition zone measurement of a gradient concentration from 0 to 100 μM showed BMEPC and BMEMC photoinduced antibacterial activity against .

Bone marrow derived mesenchymal stem cells inhibit the proliferative and profibrotic phenotype of hypertrophic scar fibroblasts and keloid fibroblasts through paracrine signaling.

Background: Hypertrophic scars and keloids, characterized by over-proliferation of fibroblasts and aberrant formation of the extracellular matrix (ECM), are considered fibrotic diseases. Accumulating evidence indicates that mesenchymal stem cells (MSCs) promote scar-free wound healing and inhibit fibrotic tissue formation, making them a potentially effective therapeutic treatment for hypertrophic scars and keloids.

Objective: To investigate the paracrine effects of bone marrow derived MSCs (BMSCs) on the biological behavior of hypertrophic scar fibroblasts (HSFs) and keloid fibroblasts (KFs).

MiR-134-Mbd3 axis regulates the induction of pluripotency.

MicroRNAs (miRNAs) are post-transcriptional modulators of gene expression and play an important role in reprogramming process; however, relatively little is known about the underlying regulatory mechanism of miRNAs on how they epigenetically modulate reprogramming and pluripotency. Here, we report that the expression level of microRNA-134 (miR-134) was low in mouse embryonic stem cells (mESCs) but significantly up-regulated during neural differentiation, while down-regulated during the induction of induced pluripotent stem cells (iPSCs) from neural progenitor cells (NPCs). Inhibition of miR-134 by miR-134 sponge promoted the efficiency of reprogramming which also was highly similar to mESCs.

Multi-stable fluorescent silica nanoparticles obtained from in situ doping with aggregation-induced emission molecules.

Microenvironment in biology is diverse and complex which has been a great challenge for in vivo imaging materials, and so materials with environmental tolerance and photostability need to be explored. For aggregation-induced emission (AIE) molecules, the fluorescence is closely related to the restricted structure which is directly affected by the microenvironment. Inorganic silica nanoparticles can provide a rigid microenvironment which can stabilize AIE molecules to obtain fluorescent materials with environmental tolerance.

Biscarbazolylmethane-based cyanine: a two-photon excited fluorescent probe for DNA and selective cell imaging.

Here, we have introduced a novel biscarbazolylmethane-based cyanine as a two-photon excited fluorescent probe, 6,6'-bis[2-(1-methylpyridinium)vinyl]-bis(9-methyl-carbazol-3-yl)methane diiodide, which has two vinylpyridinium carbazole moieties connected by a non-rigid methylene bridge. This molecule possesses a larger Stokes shift and enhanced two-photon absorption cross-section than the previously reported vinylpyridinium carbazole monocyanine, which is mainly attributed to the "through-space" type intramolecular charge transfer. The low fluorescence quantum yield and 30-fold fluorescence enhancement once binding with calf thymus DNA highlight this molecule as a promising fluorescence light-up probe for DNA.

Effect of the regulation of retinoid X receptor-α gene expression on rat hepatic fibrosis.

Aim:   To study the effect of retinoid X receptor-α (RXR-α) expression on rat hepatic fibrosis.

Methods:   Rat hepatic fibrosis was induced by CCl(4) , and the rats were randomly divided into an early-phase hepatic fibrosis group (2 weeks) and a sustained hepatic fibrosis group (8 weeks). They were then divided into four groups (normal control, hepatic fibrosis, negative control and RXR-α groups).

Peroxisome proliferator-activated receptor gamma inhibits hepatic fibrosis in rats.

Background: Hepatic fibrosis is a necessary step in the development of hepatic cirrhosis. In this study we used lentiviral vector-mediated transfection technology to evaluate the effect of peroxisome proliferator-activated receptor gamma (PPAR-gamma) on rat hepatic fibrosis.

Methods: Hepatic fibrosis in rats was induced by CCl4 for 2 weeks (early fibrosis) and 8 weeks (sustained fibrosis).