Showing papers by "Hong Liu published in 2013"
TL;DR: The as-prepared TiO( 2)@MoS(2) heterostructure shows a high photocatalytic hydrogen production even without the Pt co-catalyst and possesses a strong adsorption ability towards organic dyes and shows high performance in photocatallytic degradation of the dye molecules.
Abstract: MoS(2) nanosheet-coated TiO(2) nanobelt heterostructures--referred to as TiO(2)@MoS(2)--with a 3D hierarchical configuration are prepared via a hydrothermal reaction. The TiO(2) nanobelts used as a synthetic template inhibit the growth of MoS(2) crystals along the c-axis, resulting in a few-layer MoS(2) nanosheet coating on the TiO(2) nanobelts. The as-prepared TiO(2)@MoS(2) heterostructure shows a high photocatalytic hydrogen production even without the Pt co-catalyst. Importantly, the TiO(2)@MoS(2) heterostructure with 50 wt% of MoS(2) exhibits the highest hydrogen production rate of 1.6 mmol h(-1) g(-1). Moreover, such a heterostructure possesses a strong adsorption ability towards organic dyes and shows high performance in photocatalytic degradation of the dye molecules.
1,166 citations
TL;DR: A Ni3S2 nanorods/Ni foam composite electrode is prepared as a high-performance catalyst for the oxygen evolution reaction (OER), which exhibits excellent OER activity with a small overpotential of ∼157 mV based on the onset of catalytic current as discussed by the authors.
Abstract: A Ni3S2 nanorods/Ni foam composite electrode is prepared as a high-performance catalyst for the oxygen evolution reaction (OER), which exhibits excellent OER activity with a small overpotential of ∼157 mV based on the onset of catalytic current.
904 citations
TL;DR: The 2.7 angstrom–resolution crystal structure of human CCR5 bound to the marketed HIV drug maraviroc reveals a ligand-binding site that is distinct from the proposed major recognition sites for chemokines and the viral glycoprotein gp120, providing insights into the mechanism of allosteric inhibition of chemokine signaling and viral entry.
Abstract: The CCR5 chemokine receptor acts as a co-receptor for HIV-1 viral entry. Here we report the 2.7 angstrom-resolution crystal structure of human CCR5 bound to the marketed HIV drug maraviroc. The structure reveals a ligand-binding site that is distinct from the proposed major recognition sites for chemokines and the viral glycoprotein gp120, providing insights into the mechanism of allosteric inhibition of chemokine signaling and viral entry. A comparison between CCR5 and CXCR4 crystal structures, along with models of co-receptor-gp120-V3 complexes, suggests that different charge distributions and steric hindrances caused by residue substitutions may be major determinants of HIV-1 co-receptor selectivity. These high-resolution insights into CCR5 can enable structure-based drug discovery for the treatment of HIV-1 infection.
618 citations
TL;DR: In this paper, the Ni3S2@Ni(OH)2/3DGN was synthesized using a one-step hydrothermal reaction, and the morphological and structural evolution of the 3DGN has been investigated.
Abstract: A three-dimensional graphene network (3DGN) grown on nickel foam is an excellent template for the synthesis of graphene-based composite electrodes for use in supercapacitors. Ni(OH)2nanosheets coated onto single-crystal Ni3S2nanorods grown on the surface of the 3DGN (referred to as the Ni3S2@Ni(OH)2/3DGN) are synthesized using a one-step hydrothermal reaction. SEM, TEM, XRD and Raman spectroscopy are used to investigate the morphological and structural evolution of the Ni3S2@Ni(OH)2/3DGN. Detailed electrochemical characterization shows that the Ni3S2@Ni(OH)2/3DGN exhibits high specific capacitance (1277 F g−1 at 2 mV s−1 and 1037.5 F g−1 at 5.1 A g−1) and areal capacitance (4.7 F cm−2 at 2 mV s−1 and 3.85 F cm−2 at 19.1 mA cm−2) with good cycling performance (99.1% capacitance retention after 2000 cycles).
532 citations
TL;DR: The active light band of the novel hybrid photocatalyst with high photocatalytic activity covers full-spectrum solar light including the UV, visible, and near-infrared ranges.
Abstract: Near-infrared active photocatalytic properties of Bi2 WO6 nanosheets owing to the oxygen vacancies of the Bi2 WO6 nanosheets are reported. The broad spectrum photocatalyst, Bi2 WO6 -TiO2 nanobelt heterostructures, are obtained by assembling Bi2 WO6 nanocrystals on TiO2 nanobelts. The active light band of the novel hybrid photocatalyst with high photocatalytic activity covers full-spectrum solar light including the UV, visible, and near-infrared ranges.
513 citations
TL;DR: Curcumin-based near-infrared fluorescence imaging probes for detecting both soluble and insoluble amyloid beta (Aβ) species and then an inhibitor that could attenuate cross-linking of Aβ induced by copper are designed and synthesized.
Abstract: In this article, we first designed and synthesized curcumin-based near-infrared (NIR) fluorescence imaging probes for detecting both soluble and insoluble amyloid beta (Aβ) species and then an inhibitor that could attenuate cross-linking of Aβ induced by copper. According to our previous results and the possible structural stereohindrance compatibility of the Aβ peptide and the hydrophobic/hydrophilic property of the Aβ13-20 (HHQKLVFF) fragment, NIR imaging probe CRANAD-58 was designed and synthesized. As expected CRANAD-58 showed significant fluorescence property changes upon mixing with both soluble and insoluble Aβ species in vitro. In vivo NIR imaging revealed that CRANAD-58 was capable of differentiating transgenic and wild-type mice as young as 4 months old, the age that lacks apparently visible Aβ plaques and Aβ is likely in its soluble forms. According to our limited studies on the interaction mechanism between CRANAD-58 and Aβ, we also designed CRANAD-17 to attenuate the cross-linking of Aβ42 induced by copper. It is well-known that the coordination of copper with imidazoles on Histidine-13 and 14 (H13, H14) of Aβ peptides could initialize covalent cross-linking of Aβ. In CRANAD-17, a curcumin scaffold was used as an anchoring moiety to usher the designed compound to the vicinity of H13 and H14 of Aβ, and imidazole rings were incorporated to compete with H13/H14 for copper binding. The results of SDS-PAGE gel and Western blot indicated that CRANAD-17 was capable of inhibiting Aβ42 cross-linking induced by copper. This raises a potential for CRANAD-17 to be considered for AD therapy.
262 citations
TL;DR: With its high degradation efficiency, broad active light wavelength, and good stability, the CeO2 /TiO2 nanobelt heterostructures represent a new effective photocatalyst that is low-cost, recyclable, and will have wide application in photodegradation of various organic pollutants.
Abstract: CeO2 /TiO2 nanobelt heterostructures are synthesized via a cost-effective hydrothermal method. The as-prepared nanocomposites consist of CeO2 nanoparticles assembled on the rough surface of TiO2 nanobelts. In comparison with P25 TiO2 colloids, surface-coarsened TiO2 nanobelts, and CeO2 nanoparticles, the CeO2 /TiO2 nanobelt heterostructures exhibit a markedly enhanced photocatalytic activity in the degradation of organic pollutants such as methyl orange (MO) under either UV or visible light irradiation. The enhanced photocatalytic performance is attributed to a novel capture-photodegradation-release mechanism. During the photocatalytic process, MO molecules are captured by CeO2 nanoparticles, degraded by photogenerated free radicals, and then released to the solution. With its high degradation efficiency, broad active light wavelength, and good stability, the CeO2 /TiO2 nanobelt heterostructures represent a new effective photocatalyst that is low-cost, recyclable, and will have wide application in photodegradation of various organic pollutants. The new capture-photodegradation-release mechanism for improved photocatalysis properties is of importance in the rational design and synthesis of new photocatalysts.
249 citations
TL;DR: Overall, miR-29c in urinary exosome correlates with both renal function and degree of histological fibrosis, suggesting it as a novel, noninvasive marker for renal fibrosis.
Abstract: Micro (mi)RNAs are frequently dysregulated in the development of renal fibrosis. Exosomes are small membrane vesicles that could be isolated from urine secreted from all nephron segments. Here we s...
194 citations
TL;DR: The presence of urinary exosomal miRNA was confirmed for patients with a diversity of chronic kidney disease and the conditions of urine collection, storage and miRNA detection determined may be useful for future biomarker discovery efforts.
Abstract: Recent studies indicate that microRNA (miRNA) is contained within exosome. Here we sought to optimize the methodologies for the isolation and quantification of urinary exosomal microRNA as a prelude to biomarker discovery studies. Exosomes were isolated through ultracentrifugation and characterized by immunoelectron microscopy. To determine the RNA was confined inside exosomes, the pellet was treated with RNase before RNA isolation. The minimum urine volume, storage conditions for exosomes and exosomal miRNA was evaluated. The presence of miRNAs in patients with various kidney diseases was validated with real-time PCR. The result shows that miRNAs extracted from the exosomal fraction were resistant to RNase digestion and with high quality confirmed by agarose electrophoresis. 16 ml of urine was sufficient for miRNA isolation by absolute quantification with 4.15×10(5) copies/ul for miR-200c. Exosomes was stable at 4℃ 24h for shipping before stored at -80℃ and was stable in urine when stored at -80°C for 12 months. Exosomal miRNA was detectable despite 5 repeat freeze-thaw cycles. The detection of miRNA by quantitative PCR showed high reproducibility (>94% for intra-assay and >76% for inter-assay), high sensitivity (positive call 100% for CKD patients), broad dynamic range (8-log wide) and good linearity for quantification (R(2)>0.99). miR-29c and miR-200c showed different expression in different types of kidney disease. In summary, the presence of urinary exosomal miRNA was confirmed for patients with a diversity of chronic kidney disease. The conditions of urine collection, storage and miRNA detection determined in this study may be useful for future biomarker discovery efforts.
165 citations
TL;DR: The SnS2-RGO sheet-on-sheet nanostructure exhibits good electrochemical performances as an anode material for lithium ion batteries and is for the first time identified as an excellent visible light-driven catalyst of rhodamine B and phenol with high degradation efficiencies.
Abstract: Reduced graphene oxide (RGO) nanosheet-supported SnS2 nanosheets are prepared by a one-step microwave-assisted technique. These SnS2 nanosheets are linked with each other and dispersed uniformly on RGO surface. The SnS2-RGO sheet-on-sheet nanostructure exhibits good electrochemical performances as an anode material for lithium ion batteries. It shows larger-than-theoretical reversible capacities at 0.1 C and excellent high-rate capability at 1 C and 5 C. The composite is also for the first time identified as an excellent visible light-driven catalyst of rhodamine B and phenol with high degradation efficiencies. The removal rates of rhodamine B and phenol are 100 and 83.2%, respectively, for the SnS2-RGO composite, whereas these values are only 64.8 and 51.5% for pristine SnS2 after the same irradiation times. The outstanding electrochemical or photocatalytic performances of the composite have been attributed to the complementary effect of RGO and SnS2 in the perfect sheet-on-sheet composition nanostructure.
132 citations
TL;DR: The enhanced photocatalytic activity can be attributed to more effective charge transportations and separations arisen from the strong chemical bonding between BiOI and graphene, the high dye adsorption performance, and the increased light absorption.
TL;DR: An asymmetric organo- and gold-catalyzed one-pot sequential Mannich/hydroamination reaction has been developed and spiro[pyrrolidin-3,2'-oxindole] derivatives were synthesized in good yields and excellent enantioselectivities.
TL;DR: In this article, the composition and morphology of the papers, and the valence state of the silver in the papers were characterized by X-ray diffraction, scanning electron microscopy and Xray photoelectron spectroscopy, respectively.
TL;DR: In this article, a 3D carnation-flower-like hexagonal SnS2 hierarchical structures have been successfully synthesized through a simple microwave-assisted solvothermal process.
Abstract: Novel 3D carnation-flowerlike hexagonal SnS2 hierarchical structures have been successfully synthesized through a simple microwave-assisted solvothermal process. The as-prepared products were characterized by power X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), high-resolution transmission electron micrographs (HRTEM), selected area electron diffraction (SAED), X-ray photoelectron spectroscopy (XPS) and UV–vis diffuse reflectance spectra (DRS). The photocatalytic activity of the sample under visible-light irradiation (λ > 420 nm) was evaluated by the degradation of two different organic pollutants, rhodamine B (RhB) and phenol. The results reveal that the carnation-flowerlike SnS2 architectures show much higher photocatalytic activity than the SnS2 nanoparticles. The high catalytic performance of the SnS2 architectures comes from their hierarchical mesoporous structures, high BET surface area, high surface-to-volume ratios, and increased light absorbance. In addition, the SnS2 hierarchical architectures are stable during the photocatalytic reaction and can be used repeatedly.
TL;DR: In this paper, the surfactant-free synthesis of well-defined Fe 3 O 4 /PANI microspheres through an interfacial polymerization approach was reported, and the as-prepared magnetic composite spheres show good dispersion, core-shell structure and high magnetization.
TL;DR: Pirfenidone may be effective prior to the onset of renal fibrosis because this drug exerts its anti-fibrotic effect by protection of mitochondria in renal proximal tubular cells.
Abstract: Dysfunctional mitochondria participate in the progression of chronic kidney disease (CKD). Pirfenidone is a newly identified anti-fibrotic drug. However, its mechanism remains unclear. Mitochondrial dysfunction is an early event that occurs prior to the onset of renal fibrosis. In this context, we investigated the protective effect of pirfenidone on mitochondria and its relevance to apoptosis and oxidative stress in renal proximal tubular cells. A remnant kidney rat model was established. Human renal proximal tubular epithelial cells (HK2) using rotenone, a mitochondrial respiratory chain complex Ι inhibitor were further investigated in vitro to examine the mitochondrial protective effect of pirfenidone. Pirfenidone protected mitochondrial structures and functions by stabilizing the mitochondrial membrane potential, maintaining ATP production and improving the mitochondrial DNA (mtDNA) copy number. Pirfenidone decreased tubular cell apoptosis by inhibiting the mitochondrial apoptotic signaling pathway. Pirfenidone also reduced oxidative stress by enhancing manganese superoxide dismutase (Mn-SOD) and inhibiting intracellular reactive oxygen species (ROS) generation, which suggested that the anti-oxidant effects occurred at least partially via the mitochondrial pathway. Pirfenidone may be effective prior to the onset of renal fibrosis because this drug exerts its anti-fibrotic effect by protection of mitochondria in renal proximal tubular cells.
TL;DR: Calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis find that near the dipole-quadrupole Fano resonance, the optical binding force reverses, indicating an attractive to repulsive transition.
Abstract: We present calculations of the optical force on heterodimer of two gold nanorods aligned head-to-tail, under plane wave illumination that is polarized along the dimer axis. It is found that near the dipole-quadrupole Fano resonance, the optical binding force between the nanorods reverses, indicating an attractive to repulsive transition. This is in contrast to homodimer which in similar configuration shows no negative binding force. Moreover, the force spectrum features asymmetric line shape and shifts accordingly when the Fano resonance is tuned by varying the nanorods length or their gap. We show that the force reversal is associated with the strong phase variation between the hybridized dipole and quadrupole modes near the Fano dip. The numerical results may be demonstrated by a near-field optical tweezer and shall be useful for studying “optical matters” in plasmonics.
TL;DR: The in vitro cell study results revealed that the GCS/GO composite films were suitable for the proliferation and adhesion of mouse preosteoblast (MC3T3-E1) cells.
Abstract: A genipin-cross-linked chitosan/graphene oxide (GCS/GO) composite film was prepared using a solution casting method. Fourier transform infrared (FTIR) and ultraviolet-visible (UV-Vis) spectroscopy of the composite films showed that the interactions between the CS and oxygen-containing groups of GO resulted in good dispersion of the GO sheets in the CS network. The addition of GO decreased the expansion ratio of the composite films in physiological conditions and increased the resistance to degradation by lysozymes in vitro. As well, the tensile strength values of the GCS/GO films were significantly increased with the increasing load of GO. Moreover, the GCS/GO composite film also maintained the intrinsic fluorescence of GCS. The in vitro cell study results revealed that the composite films were suitable for the proliferation and adhesion of mouse preosteoblast (MC3T3-E1) cells. The GCS/GO biocomposite films might have a potential use in tissue engineering, bioimaging, and drug delivery.
TL;DR: The results suggest that these two THPBs compounds targeted to multiple neurotransmitter receptors may present novel lead drugs with new pharmacological profiles for the treatment of schizophrenia.
TL;DR: In this article, high electrocatalytic activity for alcohol electrooxidation by Pt nanoparticles supported on sub-micrometer-sized TiO2 spheres is achieved by using a simple wet chemical synthesis.
TL;DR: In this paper, the authors used carbodiimide to chemically modify the collagen derived from porcine acellular dermal matrix (PADM), and showed that the strength and resistance of PADM to enzymatic digestion can be adjusted by reconnection of free amino and carboxyl groups of the collagen fibers.
TL;DR: It is shown that the gating charge pathway of the voltage-gated KCNQ2 potassium channel, activity reduction of which causes epilepsy, can accommodate various small molecule ligands.
Abstract: Voltage-gated potassium (Kv) channels derive their voltage sensitivity from movement of gating charges in voltage-sensor domains (VSDs). The gating charges translocate through a physical pathway in the VSD to open or close the channel. Previous studies showed that the gating charge pathways of Shaker and Kv1.2-2.1 chimeric channels are occluded, forming the structural basis for the focused electric field and gating charge transfer center. Here, we show that the gating charge pathway of the voltage-gated KCNQ2 potassium channel, activity reduction of which causes epilepsy, can accommodate various small molecule ligands. Combining mutagenesis, molecular simulation and electrophysiological recording, a binding model for the probe activator, ztz240, in the gating charge pathway was defined. This information was used to establish a docking-based virtual screening assay targeting the defined ligand-binding pocket. Nine activators with five new chemotypes were identified, and in vivo experiments showed that three ligands binding to the gating charge pathway exhibit significant anti-epilepsy activity. Identification of various novel activators by virtual screening targeting the pocket supports the presence of a ligand-binding site in the gating charge pathway. The capability of the gating charge pathway to accommodate small molecule ligands offers new insights into the gating charge pathway of the therapeutically relevant KCNQ2 channel.
TL;DR: Pirfenidone inhibits M1 and M2 macrophage infiltration in 5/6 nephrectomized rats, which suggests its efficacy in the early and late periods of renal fibrosis.
Abstract: Tubulointerstitial macrophage infiltration is a hallmark of chronic kidney disease involved in the progression of renal fibrosis. Pirfenidone is a newly identified antifibrotic drug, the potential mechanism of which remains unclear. The aim of this study was to investigate the effects of pirfenidone on M1/M2 macrophage infiltration in nephrectomized rats. Nephrectomized rats were treated with pirfenidone by gavage for 12 wk. Twenty-four hour urinary protein, N-acetyl-β-D-glycosaminidase (NAG) activity, systolic blood pressure, and C-reactive protein were determined. Paraffin-embedded sections were stained for CD68, CCR7, and CD163 macrophages. Monocyte chemoattractant protein-1 (MCP-1) and macrophage inflammatory protein-1α (MIP-1α), as well as M1 and M2 macrophages secretory markers, were evaluated by real-time RT-PCR and Western blotting analysis. Pirfenidone significantly improved the elevated proteinuria and NAG activity from week 2 onward after surgery. Pirfenidone attenuated interstitial fibrosis and decreased expression of fibrotic markers including transforming growth factor-β(1), connective tissue growth factor, α-smooth muscle actin, fibronectin, and fibroblast-specific protein-1. Pirfenidone significantly decreased the infiltrating macrophages. The number of M1 and M2 macrophages was significantly lower after pirfenidone treatment. MCP-1 and MIP-1α were increased in nephrectomized rats at mRNA and protein levels. Pirfenidone treatment significantly inhibited their expression. The TNF-α, IL-6, and nitric oxide synthases-2 expressed by M1 macrophages were increased in nephrectomized rats, and pirfenidone significantly attenuated their expression. Pirfenidone treatment also significantly decreased arginase-1, dectin-1, CD206, and CD86 expressed by M2 macrophages. Thus pirfenidone inhibits M1 and M2 macrophage infiltration in 5/6 nephrectomized rats, which suggests its efficacy in the early and late periods of renal fibrosis.
TL;DR: This study may represent a novel starting point for the future development of improved antiflu agents and molecular modeling provided information about the binding model between the new inhibitors and neuraminidase, with the elongated groups at the C-1-position being projected toward the 430-loop region.
Abstract: In order to exploit the 430-cavity in the active sites of neuraminidases, 22 zanamivir analogs with C-1 and C-4 modification were synthesized, and their inhibitory activities against both group-1 (H5N1, H1N1) and group-2 neuraminidases (H3N2) were determined. Compound 9f exerts the most potency, with IC50 value of 0.013, 0.001, and 0.09 μM against H3N2, H5N1, and H1N1, which is similar to that of zanamivir (H3N2 IC50 = 0.0014 μM, H5N1 IC50 = 0.012 μM, H1N1 IC50 = 0.001 μM). Pharmacokinetic studies of compound 9f in rats showed a much longer plasma half-life (t1/2) than that of zanamivir following administration (po dose). Molecular modeling provided information about the binding model between the new inhibitors and neuraminidase, with the elongated groups at the C-1-position being projected toward the 430-loop region. This study may represent a novel starting point for the future development of improved antiflu agents.
TL;DR: In this article, the decoloration activity of the composite photocatalyst was investigated by adsorbing/degrading methyl orange (MO) solutions in the dark/under visible light irradiation.
TL;DR: Three distinct sets of indole-based heterocycles were rapidly and selectively synthesized from the same set of Ugi-adducts under microwave heating in a reaction-condition-controlled manner and an unprecedented metal-free intramolecular sp(3)-hybridized C-H arylation using only cesium carbonate was discovered.
TL;DR: In this article, the pure tetragonal bismuth oxiselenide nanosheets are synthesized by the composite-molten-salt approach at 200°C.
TL;DR: The results suggest that although DC260126 could not provide benefit for improving hyperglycemia, it could protect against pancreatic β-cells dysfunction through reducing overload ofβ-cells, and it increases insulin sensitivity possibly via alleviation of hyperinsulinemia in db/db mice.
Abstract: G protein-coupled receptor 40 (GPR40) mediates both acute and chronic effects of free fatty acids (FFAs) on insulin secretion. However, it remains controversial whether inhibition of GPR40 would be beneficial in prevention of type 2 diabetes. This study is designed to evaluate the potential effects of DC260126, a small molecule antagonist of GPR40, on β-cell function following administration of 10 mg/kg dose of DC260126 to obese diabetic db/db mice. Oral glucose tolerance test, glucose stimulated insulin secretion and insulin tolerance test were used to investigate the pharmacological effects of DC260126 on db/db mice after 21-days treatment. Immunohistochemistry and serum biochemical analysis were also performed in this study. Although no significant change of blood glucose levels was found in DC260126-treated mice, DC260126 significantly inhibited glucose stimulated insulin secretion, reduced blood insulin level and improved insulin sensitivity after 3 weeks administration in db/db mice. Moreover, DC260126 reduced the proinsulin/insulin ratio and the apoptotic rate of pancreatic β-cells remarkably in DC260126-treated db/db mice compared to vehicle-treated mice (p<0.05, n = 8). The results suggest that although DC260126 could not provide benefit for improving hyperglycemia, it could protect against pancreatic β-cells dysfunction through reducing overload of β-cells, and it increases insulin sensitivity possibly via alleviation of hyperinsulinemia in db/db mice.
TL;DR: Based on these Au-Ag/TiO2-NB nanostructures, a porous paper-like monolithic catalyst was fabricated and exhibited synergistically enhanced activity and stability for catalyzing aerobic oxidation of benzyl alcohol.
TL;DR: In this article, a gold(I) complex and trifluoroacetic acid (TFA) cocatalyzed one-pot, Michael addition/intramolecular cyclization cascade reaction for the synthesis of unusual tetracyclic indoles containing a seven-membered ring in water with microwave irradiation was described.