Showing papers by "Hong Liu published in 2016"
TL;DR: Compounds Currently in Phase II−III Clinical Trials of Major Pharmaceutical Companies: New Structural Trends and Therapeutic Areas is presented.
Abstract: Compounds Currently in Phase II−III Clinical Trials of Major Pharmaceutical Companies: New Structural Trends and Therapeutic Areas Yu Zhou,† Jiang Wang,† Zhanni Gu,† Shuni Wang,† Wei Zhu,† Jose ́ Luis Aceña,*,‡,§ Vadim A. Soloshonok,*,‡,∥ Kunisuke Izawa,* and Hong Liu*,† †Key Laboratory of Receptor Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China ‡Department of Organic Chemistry I, Faculty of Chemistry, University of the Basque Country UPV/EHU, Paseo Manuel Lardizab́al 3, 20018 San Sebastiań, Spain Department of Organic Chemistry, Autońoma University of Madrid, Cantoblanco, 28049 Madrid, Spain IKERBASQUE, Basque Foundation for Science, María Díaz de Haro 3, 48013 Bilbao, Spain Hamari Chemicals Ltd., 1-4-29 Kunijima, Higashi-Yodogawa-ku, Osaka, Japan 533-0024
1,740 citations
TL;DR: Using numerical simulations, it is demonstrated that, by solely exploiting a proper geometrical arrangement and WGM resonances in a TiO2 sphere, the plasmonic absorption can be extended over the entire visible range and can be increased by more than 40 times.
Abstract: Recently, surface plasmon resonance (SPR) effects have been widely used to construct photocatalysts which are active in the visible spectral region. Such plasmonic photocatalysts usually comprise a semiconductor material transparent in the visible range (such as TiO2) and plasmonic nano-objects (e.g., Au nanoparticles (Au NPs)). Specific SPRs, though, only partially cover the visible spectrum and feature weak light absorption. Here, we explore the unique role played by whispering gallery mode (WGM) resonances in the expression of the photocatalytic activity of plasmonic photocatalysts. Using numerical simulations, we demonstrate that, by solely exploiting a proper geometrical arrangement and WGM resonances in a TiO2 sphere, the plasmonic absorption can be extended over the entire visible range and can be increased by more than 40 times. Furthermore, the local electric field at the Au–TiO2 interface is also considerably enhanced. These results are experimentally corroborated, by means of absorption spectro...
220 citations
TL;DR: This study illustrates the customizability of the rGO-PEDOT hybrid microfiber for neural tissue engineering scaffolding applications, underlines the potential of a self-powered TENG electrical stimulation system for accelerating MSC differentiation into neural cells without bio/chemical cues, and suggests the TENG's practical use as a wearable stimulation system to assist nerve regeneration for a walking person.
Abstract: Engineered conductive scaffolds toward neural regeneration should have the ability to regulate mesenchymal stems cell (MSC) differentiation into neural lineage through an electrical stimulation-assisted culture process. In this work, a self-powered electrical stimulation-assisted neural differentiation system for MSCs was realized by combining a high effective triboelectric nanogenerator (TENG) to supply pulsed electric simulation signals and a poly(3,4-ethylenedioxythiophene) (PEDOT)–reduced graphene oxide (rGO) hybrid microfiber (80 μm in diameter) as a scaffold. The conductive PEDOT endows the rGO–PEDOT hybrid microfiber with an enhanced electrical conductivity and maintains a good cytocompatibility. MSCs cultured on this highly conductive rGO–PEDOT hybrid microfiber possess enhanced proliferation ability and good neural differentiation tendency. Importantly, by inducing electric pulses generated by the TENG as the electrical stimulation signal, which are triggered by human walking steps, neural differ...
210 citations
TL;DR: A heterostructured photocatalyst comprised of few-layered MoS2 nanosheets coated on a TiO2 nanobelts surface was synthesized through a simple hydrothermal treatment and can harness UV and visible light energy to decompose organic contaminants in aqueous solutions as well as split water to hydrogen and oxygen.
Abstract: Photocatalytic materials comprised of semiconductor nanostructures have attracted tremendous scientific and technological interest over the last 30 years. This is due to the fact that these photocatalytic materials have unique properties that allow for an effective direct energy transfer from light to highly reactive chemical species which are applicable in the remediation of environmental pollutants and photocatalytic hydrogen generation. Heterostructured photocatalysts are a promising type of photocatalyst which can combine the properties of different components to generate a synergic effect, resulting in a high photocatalytic activity. In this work, a heterostructured photocatalyst comprised of few-layered MoS2 nanosheets coated on a TiO2 nanobelts surface was synthesized through a simple hydrothermal treatment. The hybrid heterostructures with enhanced broad spectrum photocatalytic properties can harness UV and visible light energy to decompose organic contaminants in aqueous solutions as well as split water to hydrogen and oxygen. The mechanism of the enhancement is that the MoS2/TiO2 nanobelts heterostructure can enhance the separation of the photo-induced carriers, which results in a higher photocurrent due to the special electronic characteristics of the graphene-like layered MoS2 nanosheets. This methodology is potentially applicable to the synthesis of a range of hybrid nanostructures with promising applications in photocatalysis and other relevant areas.
129 citations
TL;DR: This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of M SCs into neural cells.
Abstract: The cell–material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM–rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM–rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM–rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM–rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.
118 citations
TL;DR: The nanocapsules with efficient photothermal conversion and excellent biocompatibility achieve a synergistic effect of photothermal and chemotherapy and can act as a multimodal imaging agent of computed tomography and photoacoustic tomography imaging for guiding the therapy.
Abstract: Carbon-based nanomaterials have been developed for photothermal cancer therapy, but it is still a great challenge to fabricate their multifunctional counterparts with facile methods, good biocompatibility and dispersity, and high efficiency for cancer theranostics. In this work, an alternative multifunctional nanoplatform is developed based on carbon–silica nanocapsules with gold nanoparticle in the cavity (Au@CSN) for cancer theranostics. The encapsulated chemodrug doxorubicin can be released from the Au@CSN with mesoporous and hollow structure in a near-infrared light and pH stimuli-responsive manner, facilitating spatiotemporal therapy to decrease off-target toxicity. The nanocapsules with efficient photothermal conversion and excellent biocompatibility achieve a synergistic effect of photothermal and chemotherapy. Furthermore, the nanocapsules can act as a multimodal imaging agent of computed tomography and photoacoustic tomography imaging for guiding the therapy. This new design platform can provide a promising strategy for precise cancer theranostics.
114 citations
TL;DR: An overview of the synthesis methods, properties, and practical applications of 1D nanostructures is provided and the prospects for future investigations are outlined.
Abstract: One-dimensional (1D) ferroelectric nanostructures, such as nanowires, nanorods, nanotubes, nanobelts, and nanofibers, have been studied with increasing intensity in recent years. Because of their excellent ferroelectric, ferroelastic, pyroelectric, piezoelectric, inverse piezoelectric, ferroelectric-photovoltaic (FE-PV), and other unique physical properties, 1D ferroelectric nanostructures have been widely used in energy-harvesting devices, nonvolatile random access memory applications, nanoelectromechanical systems, advanced sensors, FE-PV devices, and photocatalysis mechanisms. This review summarizes the current state of 1D ferroelectric nanostructures and provides an overview of the synthesis methods, properties, and practical applications of 1D nanostructures. Finally, the prospects for future investigations are outlined.
108 citations
TL;DR: This in situ polymeric encapsulation approach allows for the careful tuning of the thickness of graphite-like carbon, and it potentially constitutes a general and efficient route to prepare other oxide@C catalysts, which can therefore largely expand the applications of nanomaterials in catalysis.
Abstract: Nanocomposites composed of TiO2 and carbon materials (C) are widely popular photocatalysts because they combine the advantages of TiO2 (good UV photocatalytic activity, low cost, and stability) to the enhanced charge carrier separation and lower charge transfer resistance brought by carbon. However, the presence of carbon can also be detrimental to the photocatalytic performance as it can block the passage of light and prevent the reactant from accessing the TiO2 surface. Here using a novel interfacial in situ polymer encapsulation–graphitization method, where a glucose-containing polymer was grown directly on the surface of the TiO2, we have prepared uniform TiO2@C core–shell structures. The thickness of the carbon shell can be precisely and easily tuned between 0.5 and 8 nm by simply programming the polymer growth on TiO2. The resulting core@shell TiO2@C nanostructures are not black and they possess the highest activity for the photodegradation of organic compounds when the carbon shell thickness is 1–2...
102 citations
TL;DR: The fabrication of supercapacitor electrodes with high energy density and excellent cycling stability is still a great challenge, therefore, NiCo2S4 nanotube array/carbon aerogel and Ni co2O4 nanoneedle array/ carbon aerogels hybrid super capacitor electrode materials were synthesized by assembling Ni-Co precursor needle arrays on the surface of the channel walls of hierarchical porous carbon Aerogels derived from chitosan.
Abstract: The fabrication of supercapacitor electrodes with high energy density and excellent cycling stability is still a great challenge. A carbon aerogel, possessing a hierarchical porous structure, high specific surface area and electrical conductivity, is an ideal backbone to support transition metal oxides and bring hope to prepare electrodes with high energy density and excellent cycling stability. Therefore, NiCo2S4 nanotube array/carbon aerogel and NiCo2O4 nanoneedle array/carbon aerogel hybrid supercapacitor electrode materials were synthesized by assembling Ni–Co precursor needle arrays on the surface of the channel walls of hierarchical porous carbon aerogels derived from chitosan in this study. The 1D nanostructures grow on the channel surface of the carbon aerogel vertically and tightly, contributing to the enhanced electrochemical performance with ultrahigh energy density. The energy density of NiCo2S4 nanotube array/carbon aerogel and NiCo2O4 nanoneedle array/carbon aerogel hybrid asymmetric supercapacitors can reach up to 55.3 Wh kg−1 and 47.5 Wh kg−1 at a power density of 400 W kg−1, respectively. These asymmetric devices also displayed excellent cycling stability with a capacitance retention of about 96.6% and 92% over 5000 cycles.
98 citations
TL;DR: Investigation of the influence of graphene quantum dots on key characteristics of bone marrow derived mesenchymal stem cells (MSCs) phenotype shows that GQDs can also promote the adipogenic differentiation of MSCs, thus confirming the prevalence of their pluripotency potential.
Abstract: The influence of graphene quantum dots (GQDs) on key characteristics of bone marrow derived mesenchymal stem cells (MSCs) phenotype (i.e., self-renewal, differentiation potential, and pluripotency) is systematically investigated in this work. First, the viability and impact of GQDs on the self-renewal potential of MSCs is evaluated in order to determine a threshold for the exposing dose. Second, GQDs uptake by MSCs is confirmed due to the excellent fluorescent properties of the particles. They exhibit a homogenous cytoplasmatic distribution that increases with the time and concentration. Third, the impact of GQDs on the osteogenic differentiation of MSCs is deeply characterized. An enhanced activity of alkaline phosphatase promoted by GQDs indicates early activation of osteogenesis. This is also confirmed upon GQD-induced up-regulation of phenotypically related osteogenic genes (Runx2, osteopontin, and osteocalcin) and specific biomarkers expression (osteopontin and osteocalcin). GQDs also effectively enhance the formation of calcium-rich deposits characteristics of osteoblasts. Furthermore, genes microarray results indicate that the enhanced osteogenic differentiation of MSCs by GQDs is in progress through a bone morphogenetic protein and transforming growth factor-β relative signaling pathways. Finally, intracytoplasmatic lipid detection shows that GQDs can also promote the adipogenic differentiation of MSCs, thus confirming the prevalence of their pluripotency potential.
98 citations
TL;DR: A packaged self-powered system by hybridizing nanogenerators (PSNGS) and the connectors can significantly advance the development of self- powered implanted medical devices and wearable/portable electronics.
Abstract: A packaged self-powered system by hybridizing nanogenerators (PSNGS) is demonstrated. The performance of the PSNGS is tested in a biofluid and used for powering an electronic thermometer. Select waterproof universal connectors are designed and fabricated for energy and signal transmission. This PSNGS and the connectors can significantly advance the development of self-powered implanted medical devices and wearable/portable electronics.
TL;DR: The MPNAs for cancer theranostics pave a way toward biodegradable bio-nanomaterials for biomedical applications and respond to the local microenvironment with acidic pH and enzymes where they accumulated including tumors, liver, spleen, etc., collapse into small molecules and discrete nanoparticles, and finally be cleared from the body.
Abstract: Biocompatibility and bioelimination are basic requirements for systematically administered nanomaterials for biomedical purposes. Gold-based plasmonic nanomaterials have shown potential applications in photothermal cancer therapy. However, their inability to biodegrade has impeded practical biomedical application. In this study, a kind of bioeliminable magnetoplasmonic nanoassembly (MPNA), assembled from an Fe3O4 nanocluster and gold nanoshell, was elaborately designed for computed tomography, photoacoustic tomography, and magnetic resonance trimodal imaging-guided tumor photothermal therapy. A single dose of photothermal therapy under near-infrared light induced a complete tumor regression in mice. Importantly, MPNAs could respond to the local microenvironment with acidic pH and enzymes where they accumulated including tumors, liver, spleen, etc., collapse into small molecules and discrete nanoparticles, and finally be cleared from the body. With the bioelimination ability from the body, a high dose of 400 mg kg(-1) MPNAs had good biocompatibility. The MPNAs for cancer theranostics pave a way toward biodegradable bio-nanomaterials for biomedical applications.
TL;DR: In this article, a series of visible light-responsive Mn 0.8 Cd 0.2 S/g-C 3 N 4 hybrid materials with different g-C3 N 4 contents were synthesized via a facile hydrothermal method.
Abstract: A series of novel visible light-responsive Mn 0.8 Cd 0.2 S/g-C 3 N 4 hybrid materials with different g-C 3 N 4 contents were synthesized via a facile hydrothermal method. The obtained Mn 0.8 Cd 0.2 S/g-C 3 N 4 composites displayed highly efficient photocatalytic activities for H 2 evolution from aqueous solutions containing sacrificial reagents (Na 2 S and Na 2 SO 3 ) under visible light ( λ > 420 nm) even without noble metal co-catalysts. The highest H 2 evolution rate of 4.0 mmol h −1 g −1 (with an apparent quantum efficiency of 4.1% at 420 nm) was achieved on the Mn 0.8 Cd 0.2 S/g-C 3 N 4 (10 wt%) sample, which was about 3.40 times higher than that of pure Mn 0.8 Cd 0.2 S. The enhanced photocatalytic activity of Mn 0.8 Cd 0.2 S/g-C 3 N 4 composites should be attributed to the well-matched band structure and intimate contact interfaces between Mn 0.8 Cd 0.2 S and g-C 3 N 4 , which led to the effective transfer and separation of the photogenerated charge carriers. In addition, the Mn 0.8 Cd 0.2 S/g-C 3 N 4 photocatalysts showed good stability during the photocatalytic water splitting to hydrogen under visible light. A possible mechanism of the enhanced photocatalytic activity of Mn 0.8 Cd 0.2 S/g-C 3 N 4 was also proposed.
TL;DR: In this article, mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) nanosheets with high surface area were obtained by using SBA-15 as a hard template.
Abstract: In this study, mesoporous graphitic carbon nitride (mpg-C 3 N 4 ) nanosheets with high surface area (317 m 2 g −1 ) were obtained by using SBA-15 as a hard-template, and CdLa 2 S 4 nanoparticles were successfully grown on these mpg-C 3 N 4 nanosheets via a facile hydrothermal method. The as-synthesized CdLa 2 S 4 /mpg-C 3 N 4 hybrids were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), high-resolution transmission electron microcopy (HRTEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), N 2 adsorption-desorption, ultraviolet–visible diffuse reflection spectroscopy (DRS). Compared with pure CdLa 2 S 4 , the CdLa 2 S 4 /mpg-C 3 N 4 hybrid materials displayed higher photocatalytic H 2 evolution performance under the visible light (λ > 420 nm) using Na 2 S and Na 2 SO 3 as the sacrificial agent. The optimal content of mpg-C 3 N 4 was about 20 wt% and the corresponding photocatalytic H 2 evolution was 5984.8 μmol h −1 g −1 (with an apparent quantum efficiency of 7.1% at 420 nm), which was 7.7 times higher than that of pure CdLa 2 S 4 . The results of photoluminescence (PL) and photocurrent response demonstrated that the recombination of photo-generated electron-hole pairs was effectively inhibited due to the well-matched band structure and intimate contact interfaces of CdLa 2 S 4 and mpg-C 3 N 4 . Based on the results and analysis, a possible enhanced photocatalytic activity mechanism of CdLa 2 S 4 /mpg-C 3 N 4 composites was also proposed.
TL;DR: A one-pot chemoenzymatic synthesis of glycoengineered Herceptin using an egg-yolk sialylglycopeptide (SGP) substrate is reported, which represents a new approach for glycosite-specific and dual-drug ADC design and rapid synthesis, and also provides the structural requirement for their biologic activities.
Abstract: Chemoenzymatic transglycosylation catalyzed by endo-S mutants is a powerful tool for in vitro glycoengineering of therapeutic antibodies. In this paper, we report a one-pot chemoenzymatic synthesis of glycoengineered Herceptin using an egg-yolk sialylglycopeptide (SGP) substrate. Combining this one-pot strategy with novel non-natural SGP derivatives carrying azido or alkyne tags, glycosite-specific conjugation was enabled for the development of new antibody–drug conjugates (ADCs). The site-specific ADCs and semi-site-specific dual-drug ADCs were successfully achieved and characterized with SDS-PAGE, intact antibody or ADC mass spectrometry analysis, and PNGase-F digestion analysis. Cancer cell cytotoxicity assay revealed that small-molecule drug release of these ADCs relied on the cleavable Val-Cit linker fragment embedded in the structure. These results represent a new approach for glycosite-specific and dual-drug ADC design and rapid synthesis, and also provide the structural requirement for their biologic activities.
TL;DR: In this article, the reduced TiO2 nanobelts were prepared through reduction of pure nanobels by utilizing NaBH4, which can increase the visible light absorption, promote charge carrier trapping, and improve photogenerated electron hole separation efficiency.
TL;DR: Findings suggest that the combination of GO and PDLSCs provides a promising construct for regenerative dentistry.
Abstract: As a biocompatible and low cytotoxic nanomaterial, graphene oxide (GO) has captured tremendous interests in tissue engineering. However, little is known about the behavior of dental stem cells on GO. This study was to evaluate the bioactivity of human periodontal ligament stem cells (PDLSCs) on GO coated titanium (GO-Ti) substrate in vitro as compared to sodium titanate (Na-Ti) substrate. By scanning electron microscope (SEM), confocal laser scanning microscope (CLSM), methylthiazol tetrazolium (MTT) assay, alkaline phosphatase (ALP) activity, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot analysis, we investigated the attachment, morphology, proliferation and osteogenic differentiation of PDLSCs on these two substrates. When seeded on GO-Ti substrate, PDLSCs exhibited significantly higher proliferation rate, ALP activity and up-regulated gene expression level of osteogenesis-related markers of collagen type I (COL-I), ALP, bone sialoprotein (BSP), runt related transcription factor 2 (Runx2) and osteocalcin (OCN) compared with those on Na-Ti substrate. Moreover, GO promoted the protein expression of BSP, Runx2 and OCN. These findings suggest that the combination of GO and PDLSCs provides a promising construct for regenerative dentistry.
TL;DR: A method for the pyridine-directed, rhodium-catalyzed, site-selective C-H alkylation and arylation of pyridones using commercially available trifluoroborate reagents with perfect site selectivity is developed.
TL;DR: Rutile/anatase TiO2 (R/A-TiO2 ) heterostructured nanotree arrays are fabricated by assembling anatase nanowires as branches on rutile nanorods to enable significant advances for next-generation photodetection and photosensing applications.
Abstract: Self-powered UV photodetectors based on TiO2 nanotree arrays have captured much attention in recent years because of their many advantages. In this work, rutile/anatase TiO2 (R/A-TiO2 ) heterostructured nanotree arrays are fabricated by assembling anatase nanowires as branches on rutile nanorods. External quantum efficiencies as high as 90% are reached at 325 nm. These high quantum efficiencies are related to the higher amount of light harvesting due to the larger surface area, the better separation ability of the photogenerated carriers by the rutile/anatase heterostructure, and the faster electron transport, related to the 1D nanostructure and lattice connection at the interface of the two kinds of TiO2 . Furthermore, a self-powered wireless UV photodetector is shown with excellent wireless detection performance. Such devices will enable significant advances for next-generation photodetection and photosensing applications.
TL;DR: The fluorescent enhancement property of the photonic nitrocellulose is used to increase the fluorescent intensity for multiplex detection of two cancer biomarkers and label-free detection of human immunoglobin G based on the structure color of the photographer's nitro cellulose.
Abstract: We report a pseudo-paper microfluidic chip based on patterned photonic nitrocellulose. The photonic nitrocellulose is fabricated using self-assembled monodisperse SiO2 nanoparticles as template. The SiO2 nanoparticles form a photonic crystal having a close-packed hexagonal structure in the microchannels, so the resulting nitrocellulose has a complementary inverse-opal structure. After lamination, a hollow channel is obtained that is partially filled with the photonic nitrocellulose. Owing to the highly ordered photonic structure of the pseudo-paper chip, the flow profile of aqueous solution wicking through the channel is more uniform than conventional paper microfluidic chip. It is also found that the wicking rate of aqueous solution can be easily manipulated by changing the diameter of the self-assembled monodisperse SiO2 nanoparticles, which determines the pore size of the photonic nitrocellulose. The fluorescent enhancement property of the photonic nitrocellulose is used to increase the fluorescent int...
TL;DR: In this article, the electrical properties and microstructures of piezoelectric ceramics with different grain size distributions were investigated and it was shown that the critical region separating the ferroelectric from ergodic relaxor is located around x ǫ = 0.26.
Abstract: The electrical properties and microstructures of (1 − x ) Bi 1/2 Na 1/2 TiO 3 – x SrTiO 3 (BNT-ST100 x , 0.20 ≤ x ≤ 0.30) piezoceramics with different grain size distributions were investigated. The critical region separating the ferroelectric from ergodic relaxor is located around x = 0.26. Strains up to 0.2% could be achieved under a low driving fields ( E S max /E max >1000 pm/V. The electrostrain was largely depended on the grain size and an increment of strain up to ∼38% can be realized by increasing the grain size from 5 μm to 13 μm in the BNT-ST26 samples. The results indicate that the field-induced strain performance of BNT-based incipient piezoelectric ceramics can be tailored via microstructure modifications, an alternative strategy to enhance the electromechanical properties.
TL;DR: In this article, the energy band matching between RuO2 and TiO2 has been used to design and fabricated a paper-like porous nanobelt heterostructures for heterogeneous catalysis and presented enhanced activity and selectivity for catalyzing aerobic oxidation of benzyl acohol.
TL;DR: A route to control the differentiation of MSCs by a nanostructured surface, which can also control the location and direction of M SCs on the surface of biomaterials with micro-nano scale surface engineering, is demonstrated.
Abstract: As a physical cue for controlling the fate of stem cells, surface nanotopography has attracted much attention to improve the integration between implants and local host tissues and cells. A biocompatible surface TiO2 nanorod array is proposed to regulate the fate of bone marrow derived mesenchymal stem cells (MSCs). TiO2 substrates with different surface nanotopographies: a TiO2 nanorod array and a polished TiO2 ceramic are built by hydrothermal and sintering processes, respectively. The assessment of morphology, viability, gene expression, and protein characterization of the MSCs cultured on the different TiO2 substrates proves that a TiO2 nanorod array promotes the osteogenic differentiation of MSCs, while a TiO2 ceramic with a smooth surface suppresses it. Periodically assembled TiO2 nanorod array stripes on the smooth TiO2 ceramic are constructed by a combination of microfabrication and a chemical synthesis process, which realizes the location-committed osteogenic differentiation of MSCs. A route to control the differentiation of MSCs by a nanostructured surface, which can also control the location and direction of MSCs on the surface of biomaterials with micro-nano scale surface engineering, is demonstrated.
TL;DR: The aero-optical effects of an optical seeker with a supersonic jet for hypersonic vehicles in near space were investigated by three suites of cases, in which the altitude, angle of attack, and Mach number were varied in a large range.
Abstract: The aero-optical effects of an optical seeker with a supersonic jet for hypersonic vehicles in near space were investigated by three suites of cases, in which the altitude, angle of attack, and Mach number were varied in a large range. The direct simulation Monte Carlo based on the Boltzmann equation was used for flow computations and the ray-tracing method was used to simulate beam transmission through the nonuniform flow field over the optical window. Both imaging displacement and phase deviation were proposed as evaluation parameters, and along with Strehl ratio they were used to quantitatively evaluate aero-optical effects. The results show that aero-optical effects are quite weak when the altitude is greater than 30 km, the imaging displacement is related to the incident angle of a beam, and it is minimal when the incident angle is approximately 15°. For reducing the aero-optical effects, the optimal location of an aperture should be in the middle of the optical window.
TL;DR: Ang II induces NLRP3 inflammasome activation in TECs which is mediated by mitochondrial dysfunction, and the role of mitochondria in Ang II-infused mice with or without mitoTEMPO is examined.
Abstract: // Yi Wen 1 , Yiran Liu 1 , Taotao Tang 1 , Linli Lv 1 , Hong Liu 1 , Kunling Ma 1 and Bicheng Liu 1 1 Institute of Nephrology, Zhong Da Hospital, Southeast University, Nanjing, Jiangsu, China Correspondence to: Bicheng Liu, email: // Keywords : NLRP3 inflammasome, angiotensin II, mitochondrial dysfunction, RAS, Pathology Section Received : December 05, 2015 Accepted : June 29, 2016 Published : August 05, 2016 Abstract Growing evidence has shown that NLRP3 inflammasome activation promotes the development of tubulointerstitial inflammation and progression of renal injury. We previously found that mitochondrial dysfunction is a critical determinant for the activation of NLRP3 inflammasome in albumin-overload rats. Angiotensin (Ang) II plays an important role in mitochondrial homeostasis. Here, we investigated the role of Ang II in NLRP3 inflammasome activation and the involvement of mitochondrial dysfunction in this process. In vitro , Ang II triggered NLRP3 inflammasome activation in a dose- and time-dependent manner, and this effect is mediated by AT1 receptor rather than AT2 receptor. MitoTEMPO, a mitochondrial targeted antioxidant, attenuated Ang II induced mitochondrial reactive oxygen species (mROS) production and NLRP3 inflammation activation. Following chronic Ang II infusion for 28 days, we observed remarkable tubular epithelial cells (TECs) injury, mitochondrial damage, and albuminuria in WT mice. However, these abnormalities were significantly attenuated in AT1 receptor KO mice. Then, we examined the role of mitochondria in Ang II-infused mice with or without mitoTEMPO treatment. As expected, Ang II-induced mitochondrial dysfunction and NLRP3 inflammasome activation was markedly inhibited by mitoTEMPO. Notably, NLRP3 deletion signally protected TECs from Ang II-triggered mitochondrial dysfunction and NLRP3 inflammasome activation. Taken together, these data demonstrate that Ang II induces NLRP3 inflammasome activation in TECs which is mediated by mitochondrial dysfunction.
TL;DR: This work developed the first nickel-catalyzed direct ortho-thiolation of N-benzoyl α-amino acid derivatives, which showed wide generality, functional tolerance, and high regioselectivity.
Abstract: We developed the first nickel-catalyzed direct ortho-thiolation of N-benzoyl α-amino acid derivatives. This novel strategy showed wide generality, functional tolerance, and high regioselectivity. In addition, dipeptide derivatives were also compatible with this transformation system, providing a potential protocol for the direct modification of peptide derivatives.
TL;DR: The Cu(II)-catalyzed and chelate-directed C6-selective C–H thiolation of 2-pyridones with disulfides was developed to provide aryl and alkyl thioethers and it was found that this reaction accommodated both electronic and steric factors at the C3–C5 positions.
Abstract: The Cu(II)-catalyzed and chelate-directed C6-selective C–H thiolation of 2-pyridones with disulfides was developed to provide aryl and alkyl thioethers. This transformation uses a catalytic amount of Cu(OAc)2 and molecular oxygen in air as an oxidant, no cocatalysts or metallic oxidants are required. The reaction accommodated both electronic and steric factors at the C3–C5 positions of 2-pyridones, which is efficient for the C6 thiolation of a broad range of 2-pyridones with up to 93% yield.
TL;DR: This work has successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method and observed that the nanoparticles are cytocompatible even at a concentration as high as 800 μg ml(-1).
Abstract: Lanthanide doped fluorinated hydroxyapatite (FAp) nanoparticles are promising cell imaging nanomaterials but they are excited at wavelengths which do not match the light sources usually found in a commercial confocal laser scanning microscope (CLSM). In this work, we have successfully prepared spindle-shaped Eu/Tb codoped FAp nanoparticles by a hydrothermal method. Compared with single Eu doped FAp, Eu/Tb codoped FAp can be excited by a 488 nm laser, and exhibit both green and red light emission. By changing the amounts of Eu and Tb peaks, the emission in the green region (500–580 nm) can be decreased to the benefit of the emission in the red region (580–720 nm), thus reaching a balanced dual color emission. Using MC3T3-E1 cells co-cultured with Eu/Tb codoped FAp nanoparticles, it is observed that the nanoparticles are cytocompatible even at a concentration as high as 800 μg ml−1. The Eu/Tb codoped FAp nanoparticles are located in the cytoplasm and can be monitored by dual color—green and red imaging with a single excitation light at 488 nm. At a concentration of 200 μg ml−1, the cytoplasm is saturated in 8 hours, and Eu/Tb codoped FAp nanoparticles retain their fluorescence for at least 3 days. The cytocompatible Eu/Tb codoped FAp nanoparticles with unique dual color emission will be of great use for cell and tissue imaging.
TL;DR: The structural role of matrix exopolysaccharide (EPS) in the organization of surface-dwelling bacterial cells is examined and it is found that Myxococcus xanthus cell organization in biofilms is dependent on the formation of EPS microchannels.
Abstract: The myxobacteria are a family of soil bacteria that form biofilms of complex architecture, aligned multilayered swarms or fruiting body structures that are simple or branched aggregates containing myxospores. Here, we examined the structural role of matrix exopolysaccharide (EPS) in the organization of these surface-dwelling bacterial cells. Using time-lapse light and fluorescence microscopy, as well as transmission electron microscopy and focused ion beam/scanning electron microscopy (FIB/SEM) electron microscopy, we found that Myxococcus xanthus cell organization in biofilms is dependent on the formation of EPS microchannels. Cells are highly organized within the three-dimensional structure of EPS microchannels that are required for cell alignment and advancement on surfaces. Mutants lacking EPS showed a lack of cell orientation and poor colony migration. Purified, cell-free EPS retains a channel-like structure, and can complement EPS- mutant motility defects. In addition, EPS provides the cooperative structure for fruiting body formation in both the simple mounds of M. xanthus and the complex, tree-like structures of Chondromyces crocatus. We furthermore investigated the possibility that EPS impacts community structure as a shared resource facilitating cooperative migration among closely related isolates of M. xanthus.
TL;DR: In this paper, multi-walled carbon nanotubes (MWCNT)-reinforced reaction bonded silicon carbide (RBSC) composites were fabricated by epoxy resin curing and liquid infiltration of molten silicon at 1600°C for 90min.