Copper transport protein (CTR1), which is essential for copper uptake, also plays an important role in the cellular uptake of other heavy metal ions. In this work, the interactions of the C-terminal metalbinding domain of human CTR1 (C8) with both Ag⁺ and Hg²⁺ were studied, using ultraviolet-visible (UV-Vis) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). The results showed that Ag⁺ and Hg²⁺ bind to C8 by different binding modes. Each C8 binds to two Ag⁺, whereas one Hg²⁺ crosslinks two C8 units. In addition, the coordination of Ag⁺ to C8 has an intermediate exchange rate, whereas the binding of Hg²⁺ to C8 has a fast exchange rate. The cysteine residue of C8 is one of the most important binding sites for both Ag⁺ and Hg²⁺. However, histidine residues are also involved in the metalbinding process. Ag⁺ binds histidine preferentially, whereas Hg²⁺ prefers to bind to cysteine residues. Although the HCH motif of C8 is crucial for metal binding, some other residues can also participate in the binding of Ag⁺. These residues may be involved in the metal-transfer process in the cellular uptake of Ag⁺ by CTR1. These results provide important information for a better understanding of the mechanism of cellular uptake of metal ions by CTR1.

Increasing the operating temperature of proton exchange membrane fuel cells (PEMFCs) can not only increase their electrocatalytic activities and their tolerance to impurities, such as CO, in feed gas, and decrease the precious metal loading on the electrocatalysts, but also simplify the hydrothermal management system and increase the overall energy conversion efficiency. The core obstacle to realize high-temperature PEMFCs is the development of high-temperature proton exchange membranes (HTPEMs), so this has attracted much research interest. Among the many types of HT-PEMs, HT-PEMs based on polymeric phosphonic acid are one of the best candidates, and thus is an essential research field. In this article, we review recent research progress in HT-PEMs based on polymeric phosphonic acid, discuss the proton transport mechanism, and compare the proton conductivities, physical and chemical stabilities, and mechanical properties of pristine polymeric phosphonic acid, polymers grafted with phosphonic acid, copolymers consisting of phosphonic acid and heterocyclic bases, and composite membranes based on phosphonic acid and other materials. We finally summarize and give an overview of some of the development trends in HT-PEMs based on polymeric phosphonic acid.

The ultrafast dynamics of excited states in 3-picoline were studied using femtosecond timeresolved photoelectron imaging, coupled with time-resolved mass spectroscopy. An ultrafast internal conversion from the S₂ state to the vibrationally excited S₁ state in about 910 fs was observed. This secondary-populated S₁ state further deactivates to the S₀ state in 2.77 ps. The photoelectron energy and angular distributions show ionizations from the singlet 3p Rydberg states. Two 400 nm photon excitations to the 3s Rydberg state suggest that this state probably decays to the ground state in 62 fs.

The enhanced fluorescence effect of silver nanoparticles on a europium complex, Eu(Ⅲ)DPA, where DPA is dipicolinic acid (C₇H₅NO₄), with deionized (DI) water, heavy water, ethanol, and dimethylformamide as solvents, was studied. The results indicated that with increasing silver nanoparticle concentration, the intensities of the electric dipole transition (⁵D₀→⁷F₂)and magnetic dipole transition (⁵D₀→⁷F₁) first increased and then decreased, and the enhancement efficiency of ⁵D₀→⁷F₂ was higher than that of ⁵D₀→⁷F₁. The enhanced fluorescence effect of silver nanoparticles on Eu(Ⅲ)DPA was maximum in ethanol. In the DI water, heavy water, and ethanol solution systems, the asymmetric ratio increased significantly, but there was little change in the dimethylformamide solution system. The observed silver nanoparticle dependence of the luminescent intensity of Eu(Ⅲ)DPA was considered to be the result of stronger coupling between the surface plasmon resonance and the excited luminescence centers, and reabsorption of the surface plasmon resonance of silver nanoparticles.

The effects of proton transfer on the reaction between 2,4-diisocyanatotoluene (2,4-TDI) and active-hydrogen-containing amine compounds were calculated using density functional theory (DFT) at the B3LYP/6-31+G(d, p) level. The energy barriers are significantly reduced when a methanol molecule serves as a proton transporter or a reactive catalyst, indicating that the labile hydrogen-containing compound plays a key role in accelerating the reaction rate and proton transfer. The catalytic addition of 2,4-TDI and methyl N-methylcarbamate follows a one-step mechanism, with a transition state characterized by a sixmembered ring. However, the catalytic additions of 2,4-TDI and aromatic amines such as N-methyl-p-nitroaniline, diphenylamine, and 1,2-dihydro-2,2,4-trimethylquinoline involve two steps, with the first step as the rate-limiting step. The reactions between 2,4-TDI and aromatic amines have lower energy barriers than that between 2,4-TDI and methyl N-methylcarbamate. The aromatic amines are more active than methyl N-methylcarbamate in the reaction with 2,4-TDI, which is in a od agreement with experimental results.

Some properties of g-C₃N₄ with carbon positions doped by B, P, and S atoms were investigated using quantum mechanics (first principles). There are two symmetric carbon atoms in g-C₃N₄, named C1 and C2. C1 is easier to dope than C2, and the system doped at C1 is more stable. It was found that it is easier to dope g-C₃N₄ with B than with P and S. There are significant differences among the crystal structures after doping, this is attributed to the sizes and electronegativities of the different doping atoms. The orbital population distributions showed that the electronic valences of the B, P, and S atoms changed when the doping was changed. This shows that hybrid doped atoms linked with adjacent atoms through covalent bonds are present. The differences between the valence electrons of the dopant atoms and the substituted atoms result in new bands after doping. The emergence of a new energy band in the band gap of the original g-C₃N₄ results in a decreased band gap after doping, indicating that the conductivity of the doped system is higher than that of the non-doped system. Analyses of the optical properties of pure g-C₃N₄ and doped g-C₃N₄ show that the optical absorption spectrum of g-C₃N₄ is mainly in the ultraviolet region, and the wavelength range of light absorption is unchanged after doping with P and S. However, after doping with B, the wavelength range of light absorption extends to the visible and infrared regions. Strong absorption in the infrared region shows that the photocatalytic activity of g-C₃N₄ after doping with B is much higher than that of undoped g-C₃N₄. The electron energy loss spectrum, optical conductivity spectrum, and the dielectric function curve support these points.

We investigated the effect of alkali-metal-atom doping on the electronic transport properties of BDC60 molecules, using a combination of first-principles density-functional theory and the non-equilibrium Green's function. Our calculation results show that alkali-metal-atom-doped BDC60 molecules exhibit od rectifying and negative differential resistance behaviors at very low bias. The intrinsic mechanisms for these phenomena are discussed systematically in terms of the transmission spectra and frontier molecular orbitals, as well as their spatial distributions under various external applied biases. Our study will help in developing future applications of BDC60 molecules in low-bias rectifying and negative differential resistance molecular devices.

The effect of pH on the corrosion resistance of Alloy 800, one of the preferred nuclear steam generator tubing materials, was investigated using in-situ scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS). The experimental results show that positive feedback is observed in the probe approach curve (PAC) in acidic chloride solutions, indicating that Alloy 800 is active in acidic solutions; the EIS at the corrosion potential in acidic solutions exhibits an intact capacitance arc. However, negative feedbacks are observed in the PAC in either neutral or basic chloride solutions, showing that Alloy 800 is self-passivated in these two solutions. The EIS plots at different anodic potentials show incomplete capacitance arcs, and the arc radius decreases with increasing potential, indicating that the corrosion resistance of the passive film decreases. The SECM images show that the surface reactivity increases (or the dissolution rate of the passive film increases) as the polarization potential increases from the corrosion potential to the positive direction; this is verified by an increased tip current. Some "active spots" can be seen on the SECM images in neutral or basic chloride solutions, which are possibly related to grain boundaries, triple points, and/or inclusions.

In this study, the influences of alkali concentration, oxygen partial pressure, and temperature on the oxygen reduction reaction (ORR) were examined in detail, using a specially designed electrochemical cell, by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) in NaOH solutions. It was found that the ORR pathway is dependent on the solution alkalinity, and is transformed from a two-electron reduction by forming HO₂^- in dilute solutions to a one-electron reduction by forming stable O₂^- in concentrated solutions. The process was significantly suppressed by decreases in the oxygen solubility and increases in the media viscosity. The oxygen pressure had a significant influence on the ORR, substantially promoting the ORR in alkaline solutions as a result of the greatly increased solubility of oxygen in the solutions. We obtained the Henry's constants of oxygen in NaOH solutions with different concentrations. The temperature had a clear dual effect on the ORR, as shown by the existence of an optimal temperature for the ORR in a given alkaline solution. These observations are discussed in terms of the oxygen reaction activity, oxygen solubility, and diffusion coefficient.

Rod-like LiFePO₄/C particles with different aspect ratios were synthesized by controlling the reflux reaction time in polyol medium at a low temperature, using an Fe³⁺ salt as the iron source. The precursors and final LiFePO₄/C samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge test. The results show that the reflux reaction time has a significant effect on the characteristics of the LiFePO₄ precursors and electrochemical performance of the final LiFePO₄/C samples. The morphology of the precursors is transformed from irregular short rod-like particles into regular long rod-like particles, and the aspect ratios of the rods increase with increasing reflux reaction time from 4 to 16 h. At a reflux reaction time of 10 h, the material contains multifarious morphologies, which is beneficial to the electron transmission, and displays an excellent electrochemical performance at low discharge rates, the discharge capacity is 163 mAh·g^-1 at 0.1C rate. Extension of the reflux reaction time to 16 h, the material reveals the biggest aspect ratio, which is conducive to the diffusion of lithium ions, and gives od electrochemical performance at high discharge rates, the discharge capacities are measured to be 135, 125, 118, 110, and 98 mAh·g^-1 at 1C, 3C, 5C, 10C, and 20C rates, respectively, revealing od cycling performance and little capacity fading.

Hollow mesoporous tungsten trioxide microsphere (HMTTS) was synthesized by spay drying method and employed as the support material for Pd catalyst. The catalyst was characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The Pd nanoparticles had a face-centered cubic crystal structure and were well dispersed on the external walls of HMTTS. The as-prepared Pd/HMTTS catalyst exhibits higher electrocatalytic activity and od stability during formic acid oxidation in comparison to Pd/WO₃ catalyst. The enhanced catalytic performance is attributed to the unique structure and surface properties of HMTTS and the hydrogen spillover effect which greatly accelerates the direct dehydrogenation of formic acid on palladium.

An olivine LiFePO₄/carbon (C-LiFePO₄) nanocrystallinematerial was prepared using a low-temperature solvothermalmethod, followed by a high-temperature post-annealing process. Then polytriphenylamine (PTPAn)-modified C-LiFePO₄ (C-LiFePO₄/PTPAn) was prepared, as a composite for novel cathodes for lithium-ion batteries, by solution blending of the C-LiFePO₄ nanocrystallinematerial and the electroactive conducting polymer PTPAn. The effects of PTPAn coating of the C-LiFePO₄/PTPAn samples were investigated using X-ray diffraction (XRD), scanning electronmicroscopy (SEM), transmission electronmicroscopy (TEM), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge testing. The results indicated that the solution blending method produced a compact PTPAn coating on the C-LiFePO₄, providing an effective electronic/ionic conducting pathway and enhancing the electrochemical activities of C-LiFePO₄-based composites. The C-LiFePO₄/10%(w) PTPAn electrode displayed an improved initial discharge capacity of 154.5mAh·g^-1 at 0.1C, a superior high-rate performance discharge capacity of 114.2 mAh·g^-1 at 10C, and excellent cycling stability.With further increases in the PTPAn content of the coating on the C-LiFePO₄/PTPAn composite, the electrochemical properties of the composite decreased. Electrochemical impedance measurements also demonstrated that the PTPAn coating significantly decreased the charge-transfer resistance of the C-LiFePO₄ electrode.

Ce_0.8Nd_0.2O_1.9 (NDC) and La_0.95Sr_0.05Ga_0.9Mg_0.1O_3-δ (LSGM) electrolytes were each prepared using a sol-gel method. NDC-LSGM composite electrolytes were then prepared by adding 0-15% (w, mass fraction) precalcined LSGM powders to NDC sols. The microstructure and phase composition of the pellets were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and energydispersive X-ray spectroscopy (EDS). The electrical conductivities of the pellets were measured using alternative current (AC) impedance spectroscopy. The results showed that all the composites were composed of the cubic fluorite structure, perovskite structure, and secondary phases. The LSGM additive significantly promoted grain growth. The grain boundary conduction increased greatly as a result of the presence of phase interfaces and mitigation of the harmful effects of SiO₂ impurities. NL10 was found to have the highest conductivities (σ_gb=12.15×10^-4 S·cm^-1, σ_t=3.49×10^-4 S·cm^-1 at 400 ℃); these values are 7.62 and 1.91 times higher than those of NDC (σ_gb=1.41×10^-4 S·cm^-1, σ_t=1.2×10^-4 S·cm^-1). The enhancement of the total conductivity of NL10 is mainly attributed to the large increase in grain boundary conductivity.

Linear block polyethers, i.e., poly(ethylene oxide) (PEO)-poly(propylene oxide) (PPO)-PEO (LPE), and X-shaped block polyethers, i.e., PEO-PPO-PEO (TPE), with same EO/PO ratios and molecular masses were synthesized by anionic polymerization. The aggregation behaviors at air/water and n-heptane/water interfaces were systematically studied. The results show that LPE is more efficient at decreasing the surface tension of water and n-heptane than TPE is. The dynamic interfacial tension curves indicate that the lag-time of the adsorption of the block polyethers at the n-heptane/water interface is smaller than that at the air/water surface, implying that immersion of the PO groups in the oil phase is more energetically favorable than immersion in the air phase. The oil molecules can insert into the adsorption layer, and hydrophobic interactions between oil molecules and PO moieties lead to a relatively ordered arrangement of adsorbed polyether molecules. At the n-heptane/water interface, diffusion of the block polyethers is faster than that at the air/water surface. The dilatational elasticity at the n-heptane/water interface is much higher than that at the air/water surface.

Hydrogels are important functional materials with many potential applications. Anovel hemicellulosebased magnetic hydrogel was synthesized using a graft copolymer method, with H₂O₂-Vc as a redox initiator system to initiate the hemicellulosic derivative and surface-modified Fe₃O₄ particles as the magnetic component. The structures and morphologies of the prepared magnetic hydrogels were investigated using Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM). The crystal structure of the modified Fe₃O₄ particles and the magnetic behaviors of the hemicellulosebased magnetic hydrogels were analyzed using X-ray diffraction (XRD) and a vibration sample magnetometer (VSM), respectively. The results showed that the Fe₃O₄ particles were well dispersed in the hydrogel matrix and the prepared hydrogels had paramagnetic properties. The effects of the acrylic acid/hemicellulose ratio and the amounts of Fe₃O₄ particles and cross-linker on the swelling ratio of the hydrogels were studied, and the swelling mechanism of the hydrogels was explored. The swelling behaviors of the hydrogels were simulated using Fickian and Schott kinetic models in a pH 8 buffer solution. The pore size and swelling ratio of the prepared hydrogels increased with increasing the pH value because the ―COOH groups in the hydrogels were converted to ―COO^- at higher pH values. In addition, the prepared hydrogels were used to adsorb lysozyme; the adsorption capacity of the magnetic hydrogel was much higher than that of a non-magnetic hydrogel, and the equilibrium adsorption data fitted the Freundlich and Temkin isotherm models well.

Uniform molecularly imprinted polymeric microspheres (EM-MIPMs) were prepared by emulsion polymerization using erythromycin as the template molecule, methacrylic acid (MAA) as the functional monomer, and ethylene glycol dimethacrylate (EDMA) and sodium dodecylbenzene sulfonate (SBS) as the cross-linker and emulsifier, respectively. The obtained erythromycin-MAA complexes were characterized using ultraviolet (UV) absorption spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, and ¹H nuclear magnetic resonance (NMR) spectroscopy. The results showed that erythromycin-MAA complexes were obtained by cooperative hydrogen-bonding interactions. The surface features and thermal stability of the EM-MIPMs were investigated using scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). The average diameter of the EM-MIPMs was 4.24 μm, larger than non-imprinted polymeric microspheres. They exhibited excellent thermal stability. Kinetic, equilibrium adsorption, and selectivity adsorption experiments (solid-phase extraction) were used to evaluate the binding properties and molecule recognition characteristics of EM-MIPMs for erythromycin. The experimental kinetic data were well described by a pseudo-second-order kinetic model. Erythromycin binding was examined using the Langmuir and Freundlich isotherm models. The EM-MIPMs had an excellent affinity for erythromycin. The equilibrium experimental data for the EM-MIPMs fitted the Langmuir isotherm well, and the binding amount reached 0.242 mmol·g^-1. Furthermore, solid-phase extraction experiments demonstrated that the EM-MIPMs had a higher affinity for the target molecules than for roxithromycin and erythromycin ethylsuccinate.

Pd nanoparticles (NPs) supported on a metal-organic framework (MOF), MIL-53(Al) (MIL: Materials of Institut Lavoisier), were prepared using the incipient wetness impregnation method. The structures of the synthesized Pd/MIL-53(Al) catalysts were determined using X-ray diffraction (XRD), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The same peaks were observed in the XRD patterns of Pd/MIL-53(Al) before and after the catalytic reaction, confirming that the integrity of the MIL-53(Al) support was maintained. The TEM results indicated that the crystalline porous structure of MIL-53(Al) favored the formation of highly dispersed Pd NPs of average size 2.21 nm. The heterogeneous catalytic composite materials exhibited high activities for CO oxidation, with full conversion at 115 ℃. The catalytic activity and structure of Pd/MIL-53(Al) were stable after several reaction runs.

Boron-doped β-SiC (B_xSiC) photocatalysts were prepared by in-situ carbothermal reduction, and their photocatalytic performances for H₂ evolution under visible light irradiation were investigated. The crystal structure, surface property, morphology, and band gap structure of the B_xSiC photocatalysts were studied using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. The characterization results indicate that B atoms have doped into the SiC lattice and substituted Si sites, leading to the formation of a shallow acceptor level above the valence band of SiC, resulting in a narrowed band gap energy. The shallow acceptor level acts as a hole trap, preventing the recombination of photo-excited electrons and holes. Therefore, the photocatalytic H₂ evolution activity of B-doped SiC was greatly improved compared with that of SiC. The highest hydrogen evolution rate was obtained when the B/Si molar ratio was 0.05.

A novel photocatalyst, C@CdS/halloysite nanotubes (HNTs), was synthesized using a facile and effective pyrolytic method. The as-prepared photocatalyst was characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, specific surface area measurements, and X-ray energy dispersive, ultraviolet-visible diffuse reflectance, Fourier-transform infrared, specific surface area, and Raman spectroscopies. The photocatalytic activity of the sample was evaluated by the degradation of tetracycline (TC) under visible-light irradiation. The influence of different pyrolysis temperatures on the photocatalytic degradation of TC was investigated. The optimal pyrolysis temperature was found to be 400 ℃. The photodegradation rate reached 86% in 60 min under visible-light irradiation. In addition, benefiting from the common effects of carbon, CdS, and HNTs, the photocatalyst exhibited od chemical stability. After being laid aside for one year, the photocatalytic efficiency was unaffected and the photocatalyst retained its high catalytic activity after three catalytic cycles. Based on our experimental results, the preparation mechanism and degradation of the intermediate product of TC are discussed.

The development of low-cost and effective electrocatalysts for air electrodes is critical for practical applications of lithium/oxygen batteries. In the present work, phenanthroline (phen) was used as a ligand to prepare a Co(phen)₂ complex. The Co(phen)₂ complex was coated on BP2000 and then heat treated at 600, 700, 800, and 900 ℃, to obtain carbon-supported Co-N (Co-N/C) catalysts. The catalytic activities in oxygen reduction reaction/oxygen evolution reaction (ORR/OER) of the prepared catalysts were measured and compared with those of a typical carbon-supported cobalt tetramethoxyphenylporphyrin (CoTMPP/C) catalyst. The influence of the calcination temperature on the composition and structure of the Co-N/C catalysts was investigated. Electrochemical tests showed that the Co-N/C catalysts prepared at 700 and 800 ℃ gave better performances, comparable to that of the CoTMPP/C catalyst. The superior electrochemical performance of the prepared Co-N/C catalysts and the low cost of the phenanthroline chelating agent make Co-N/C a promising cheap catalyst for lithium/oxygen batteries.

A series of Cu/Fe₂O₃ catalysts with different Cu loadings were prepared using a co-precipitation method, and the relationship between their structures and catalytic activities for the water gas shift (WGS) reaction was carefully examined. It was found that the as-prepared Cu/Fe₂O₃ catalysts exhibit excellent WGS performances, in particular, the one containing 20% (w) CuO (CF-20) shows the best catalytic activity, with CO conversion of 97.2% at 250 ℃. Its catalytic stability is also outstanding during the temperature range of 250-400 ℃. X-ray diffraction (XRD), N₂ physisorption, and H₂ temperature program reduction (H₂-TPR) techniques were used to characterize the crystal phases, textures, and reduction properties of the Cu/Fe₂O₃ catalysts. The results show that the generation of CuFe₂O₄, which has a spinel structure in stabilizing Cu microcrystals and is easier to be reduced at low temperature, resulting in enhancing their reduction properties and facilitating electrons transfer between Cu and Fe₂O₃, thus greatly improving the catalytic performance. Furthermore, (NH₄)₂CO₃ solution treatment of the as-prepared catalysts was performed to study the effect of bulk CuO existed in the Cu/Fe₂O₃ catalysts. The result suggests that the bulk CuO is favor for H atom transfer between Cu and Fe₂O₃, thus promoting the reduction of CuFe₂O₄, finally improving the catalytic performance.

Three new acceptor-donor-acceptor (A-D-A) up-converted fluorescent molecules were designed and synthesized. Their structures were characterized using Fourier transform infrared and hydrogen nuclear magnetic resonance spectroscopy, mass spectrometry, and elemental analysis. The linear absorption spectra, single-photon excited fluorescence spectra, and fluorescence quantum yields were measured in different solvents. The two-photon absorption and up-converted fluorescent properties were studied using a femtosecond laser. The results showed that the fluorescence quantum yields were 0.20-0.68, the two-photon absorption cross-sections were 16×10^-50-101×10^-50 cm⁴·s·photon^-1, and they exhibited strong blue up-converted fluorescence.

Matrix metalloproteinase-13 (MMP-13) is an interesting target for the prevention and therapy of osteoarthritis (OA). Interruption of MMP-13 activity with an inhibitor has the potential to affect OA. However, a broad-spectrum inhibitor, which restrains the other members of the MMP family, especially MMP-1, can cause musculoskeletal syndrome. So, the design and discovery of potential and highly selective inhibitors for MMP-13 over MMP-1 are necessary and of great significance for the development of novel therapeutic agents against OA. Two machine-learning (ML) methods, support vector machine and random forest (RF), were explored in this work to develop classification models for predicting selective inhibitors of MMP-13 over MMP-1 from diverse compounds. These ML models achieved promising prediction accuracies. Among the two ML models, RF gave the better performance, i.e., 97.58% for MMP-13 selective inhibitors and 100% for non-inhibitors. We also used different feature selection methods to extract the molecular features most relevant to selective inhibition of MMP-13 over MMP-1 from the two models. In addition, the betterperforming RF model was used to perform virtual screening of MMP-13 selective inhibitors against the "fragment-like" subset of the ZINC database to enrich the potential active agents, thereby obtaining a series of the most potent candidates. Our study suggests that ML methods, particularly RF, are potentially useful for facilitating the discovery of MMP-13 inhibitors and for identifying the molecular descriptors associated with MMP-13 selective inhibitors.

Dopamine, which is an important neural transmitter in brain tissue, needs to move freely within and through cell membranes to fulfill its function. The molecular dynamics of dopamine diffusion within and permeation through, cell membranes are involved in smoothing dopamine molecular protective channels, associated with schizophrenia and Parkinson's disease. In the present work, using a 1-palmitoyl-2-oleoyl-glycero-3-phosphatedylcholine (POPC) phospholipid bilayer membrane to model the cell membrane, we obtained the freeenergy changes (ΔG) for dopamine diffusion within and permeation through the cell membrane, using molecular dynamics simulations, and probed the molecular dynamics of dopamine diffusion and permeation. The obtained values of ΔG for dopamine diffusion within the cell membrane were 10-54 kJ·mol^-1 at 310 K, which implies that dopamine diffuses easily horizontally and vertically within the cell membrane to protect smoothing of the protective channel. However, it is not easy for dopamine to permeate through the cell membrane, because ΔG for this process was 117-125 kJ·mol^-1 (310 K). Superfluous dopamine passes through the dopaminemolecular protective channel and enters themiddle region of the phospholipid bilayer membrane, and then diffuses easily along the horizontal and vertical orientations within the cell membrane, even permeating through the cell membrane, preventing schizophrenia. It is therefore important for the normal function of a biological cell membrane to protect smoothing of dopamine molecular protective channels, preventing schizophrenia. These results are in agreement with other experimental observations.

When a sticky gel consisting of an aqueous HAuCl₄ solution mixed with poly-vinylpyrrolidone (PVP) surfactant is kept at room temperature (about 30 ℃), the HAuCl₄ is reduced by the PVP, resulting in the formation of nanostructures. In this study, ld nanoplates with new shapes, which were single crystalline, several micrometers wide, and tens of nanometers thick, were mass-synthesized by adjusting the crystal growth conditions. For example, through inducing temperature decrease (10-20 ℃) in the early stage of crystal growth, the product is dominated by star-like ld nanoplates, together with other new shapes such as shields, concave and convex triangles, corner snipped shapes, triple branched shapes, and shapes that are step-rich in the side plane. Based on theoretical calculations, we present the growth mechanism of these new ld nanoplates. Under certain growth conditions, the (111) plane of the ld crystal can grow not only along the <110> direction into regular triangular or hexa nal nanoplates, but also along other directions such as <211> and <321>, to give new nanoplates with high-index side facets.