Transferring the high strength of individual carbon nanotubes (CNTs) to macroscopic fibers is still a major technical challenge. In this study, CNT fibers are wound from a hollow cylindrical assembly. In particular, atomized catalytic pyrolysis is utilized to produce the fiber and control its purity.
View Article and Find Full Text PDFCarbon nanotube (CNT) materials show large degradation in tensile strength when they are exposed in chemically active environments due to the loss of inter-tube bonding. Here, we report the suppression of such degradation by chemical vapor infiltration of amorphous carbon into CNT films. The amorphous carbon generated by the thermal decomposition of the gaseous hydrocarbon of acetylene is firmly bonded on the CNT sidewalls and intersections.
View Article and Find Full Text PDFVertically aligned carbon nanotubes (VACNTs), a unique group of highly aligned CNTs normal to a substrate, have been extensively studied during the past decades. However, it is a long-standing challenge to improve the height of VACNTs due to the incidental deactivation of catalysts during growth. Herein, we demonstrate a facile strategy toward synthesizing high-density and well-aligned CNT arrays from formed Fe-based catalysts on a stainless steel (SS) mesh.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
September 2022
Two previously undescribed steroidal alkaloids, compounds 1-2, along with two known ones(3-4), were isolated from the 80% ethanol extract of ripe berries of Solanum nigrum by chromatographic methods, including silica gel, ODS, and HPLC. Based on spectroscopic and chemical evidence, including IR, NMR, and HR-ESI-MS data, the structures of the isolated compounds were identified as 12β,27-dihydroxy solasodine-3-O-β-D-glucopyranoside(1), 27-hydroxy solasodine-3-O-β-D-glucopyranosyl-(1→4)-α-L-rhamnopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→4)]-β-D-glucopyranoside(2), solalyraine A(3), and 12β,27-dihydroxy solasodine(4). Compounds 1-2 were tested for their potential effects against the proliferation of A549 cells, which revealed that compounds 1-2 had weak cytotoxic activity.
View Article and Find Full Text PDFEight undescribed, along with five known steroidal alkaloids were isolated from Solanum nigrum L., a plant used in traditional Chinese medicine. Their structures were elucidated by NMR, HR-ESI-MS, and IR spectroscopy.
View Article and Find Full Text PDFThermally insulating materials (TIMs) with ultra-low thermal conductivity, fire-retardancy, and mechanical stability are demanded to improve energy efficiency in many fields, such as petrochemical plants, energy-saving buildings, and aerospace. However, traditional polymer-based TIMs could not meet these demands. Herein, we propose a direct foaming strategy for obtaining carbon nanotube (CNT) aerogels by the gradual expansion of CNT films with H2O2 as a foaming agent at room temperature.
View Article and Find Full Text PDFCarbon nanotubes (CNTs) have been considered as promising electrode materials for energy storage devices, especially flexible electronics owing to their excellent electrical, physicochemical and mechanical properties. However, the severe aggregation between CNTs significantly reduces the electrochemically active surface areas and thus degrades the electrochemical properties. In this study, we demonstrate a facile layer-by-layer strategy toward preparing a CNT/hollow carbon nanocage (HCNC) hybrid film.
View Article and Find Full Text PDFFor applications in energy-saving buildings, aerospace industry, and wearable electronic devices, thermally insulating materials (TIMs) are required to possess not only low thermal conductivity but also light weight, mechanical robustness, and environmental stability. However, conventional TIMs can rarely meet these requirements. To overcome this shortcoming, we propose a new strategy for preparing TIMs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2020
Antireflective (AR) materials are required to possess high optical antireflection and mechanical stability for their practical applications in optical, opto-electronic, and electron-optical devices. However, the AR materials developed so far can hardly meet these requirements. Here, we report the construction of a highly porous and sponge-like material based on carbon nanotubes (CNTs).
View Article and Find Full Text PDFIn this study, seven previously undescribed steroidal glycoalkaloids, compounds 1-7, were isolated from Solanum lyratum, along with two known ones (8 and 9). Comprehensive spectroscopy techniques were used to determine their structures. Although 1-8 only showed a weak inhibitory effect on the proliferation of the tumor-derived vascular endothelial cells, however, in a former study we found both total steroidal glycoalkaloids from Solanum lyratum (TSGS) and 9 significantly inhibited tumor angiogenesis and its mechanism was linked to its ability to interfere with cell membrane lipid rafts.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2019
To achieve fuel cell commercialization, the performance improvement and cost reduction of catalysts are still the main challenges. To enhance the catalytic activity and durability for oxygen reduction reaction (ORR), we prepare Au-PtFe particles entrapped in a porous carbon and then convert them to have a fine-grained and highly ordered intermetallic structure. The optimal Au-PtFe particles in catalyzing ORR exhibit initial specific and mass activities 9 times higher than the commercial catalyst of Pt/C.
View Article and Find Full Text PDFBiomed Pharmacother
December 2018
An-te-xiao capsule consists of total alkaloids from the dried whole plantof Solanum lyratum, and showed antitumor effects in our previous study. However, its inhibitory effect on multiple non-small cell lung cancer (NSCLC) cell lines and the underlying mechanisms have not been elucidated clearly. This study sought to investigate the inhibitory effects of An-te-xiao capsule on three main types of NSCLC cell lines (A549, NCI-H460, and NCI-H520) in vitro and in vivo and the underlying mechanisms of action including its potential anti-angiogenesis effects.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
July 2018
Standard decoction of traditional Chinese medicine (TCM) is prepared by standardized process, and can be used as references to evaluate the quality of dosage forms such as decoction and dispensing granules. In order to determine the quality evaluation method for standard decoction of Chrysanthemi Flos and investigate its application, 10 batches of white chrysanthemum of Hangzhou were collected to prepare the standard decoction of white chrysanthemum of Hangzhou with standardized process parameters. Parameters such as traits, relative density, pH value, extraction ratio, transfer rate and fingerprint were selected as the indexes for quality evaluation.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
June 2018
The hawthorn leaves have the effect of activating blood, removing blood stasis, regulating qi through the veins, dissolving turbidity and lowering lipid. Procyanidinis is one of its main active components and plays an important role in regulating vasoactivity. Previous studies showed that the regulating effect of procyanidins was related to its regulation on nitric oxide secretion from vascular endothelial cells, and this effect was dependent on the extracellular calcium concentration, suggesting that the changes in intracellular calcium ion concentration in endothelial cells may play a key role in this process.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
December 2015
The accurate medical treatment is based on the information of the genome, which is the best treatment for the patients. Population pharmacokinetic study can be formulated according to the individual differences of patients to the dose, in the accurate medical model which has a unique advantage. At present, there are many problems such as adverse drug reaction in Chinese traditional medicine, and it is necessary to introduce a group of medicine on the basis of precise medical treatment.
View Article and Find Full Text PDFACS Appl Mater Interfaces
March 2016
So far, preparation of high-performance carbon nanotube (CNT)/polymer composites still faces big challenges mainly due to the limited control of CNT dispersion, fraction, and alignment in polymers. Here, a new "layer-by-layer deposition" method is put forward for preparing CNT/polymer composite fibers using poly(vinyl alcohol) (PVA) as an exemplary polymer. This is based on the continuous production of a hollow cylindrical CNT assembly from a high temperature reactor and its shrinking by a PVA-containing solution and deposition on a removable substrate wire.
View Article and Find Full Text PDFSo far, simultaneously realizing the continuous, controllable, and scalable preparation of carbon nanotube (CNT) film has remained a big challenge. Here, we report a scalable approach to continuously prepare CNT film with good control of film size and thickness. This is achieved through the layer-by-layer condensation and deposition of a cylindrical CNT assembly that is continuously produced from a floating catalyst CVD reactor on a paper strip.
View Article and Find Full Text PDFRealizing the continuous and large scale preparation of particle/carbon nanotube (CNT) composites with enhanced functionalities, and broad applications in energy conversion, harvesting, and storage systems, remains as a big challenge. Here, we report a scalable strategy to continuously prepare particle/CNT composite films in which particles are confined by CNT films. This is achieved by the continuous condensation and deposition of a cylindrical assembly of CNTs on a paper strip and the in situ incorporation of particles during the layer-by-layer deposition process.
View Article and Find Full Text PDFA new method is reported for preparing carbon nanotube (CNT) films. This method involves the continuous production of a hollow cylindrical CNT assembly and its condensation on a winding drum. The alignment and densification of CNTs in the film are improved by controlling the winding rate and imposition of mechanical rolling, respectively.
View Article and Find Full Text PDFAlthough many population pharmacokinetics (PPK) researches have been conducted on chemical drugs, few have been in the field of Chinese medicine (CM). Each ingredient in CMs possesses different pharmacokinetic characteristics, therefore, it is important to develop methods of PPK studies on them to identify the differences in CM drug safety and efficacy among the population subgroups and to conduct quantitative studies on the determinants of CM drug concentrations. To develop an expert consensus on study design and implementation for PPK of CM, in August 2013, 6 experts in the field of PPK, CMs pharmacology, and statistics discussed problems on the PPK research protocol of CMs, and a consensus was reached.
View Article and Find Full Text PDFLocalized surface plasmon (LSP) enhanced waveguide-type ultraviolet light-emitting diodes (LEDs) were fabricated by sputtering Ag nanoparticles (Ag-NPs) onto ZnO/MgZnO core/shell nanorod array (CS-NRA)/p-GaN heterostructures. A ∼9-fold enhancement of ZnO ultraviolet electroluminescence (EL) was demonstrated by the Ag-NPs decorated LED compared with the device without Ag-NPs. Angle-dependent EL measurements, as well as finite-difference time-domain simulations of the EL intensity spatial distribution, confirmed the waveguide-type EL transmission mode along the NR's axial direction.
View Article and Find Full Text PDFGraphene sheets (GNS) were synthesized continuously by spray pyrolysis of iron carbonyl and pyridine. The Pt catalyst supported on GNS exhibited excellent durability for oxygen reduction reaction (ORR). The GNS, when used as a metal-free catalyst for ORR, showed performance even better than the commercial Pt/C catalyst.
View Article and Find Full Text PDFObjective: To study the chemical constituents of the PTP 1B inhibitory effective parts of Paeoniae Rubra Radix.
Methods: The effective part of Paeoniae Rubra Radix was enriched by Sephadex LH-20. Compounds were isolated by various column chromatography and their structures were elucidated through spectroscopic analysis.
Low durability is the major challenge hindering the large-scale implementation of proton exchange membrane fuel cell (PEMFC) technology, and corrosion of carbon support materials of current catalysts is the main cause. Here, we describe the finding of remarkably high durability with the use of a novel support material. This material is based on hollow carbon nanocages developed with a high degree of graphitization and concurrent nitrogen doping for oxidation resistance enhancement, uniform deposition of fine Pt particles, and strong Pt-support interaction.
View Article and Find Full Text PDFZhongguo Zhong Yao Za Zhi
September 2013
In population pharmacokinetic (PPK) research of Chinese medicines with narrow therapeutic windows of toxicity, or when the target population is not homogeneous, or when there are frequent adverse reactions to parenterally administered Chinese medicine, select those that have a definite therapeutic effect, and in which the compositions of the toxic substances compositions are known, for study, and use complete PPK sampling design to take samples at specific time points. Use gas chromatography, HPLC, and LC-MS methods for the detection of target components. Finally, use total quantity statistical moment analysis, to account for each component of the PPK parameters.
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