Search

Chemoresistance has become a primary hurdle in the therapeutic outcome of hepatocellular carcinoma. Substantial evidences have demonstrated that microRNAs (miRNAs) are closely associated with the chemoresistance of hepatocellular carcinoma (HCC). Our investigation is aimed at testifying the influence of microRNA-15a-5p (miR-15a-5p)/eukaryotic translation initiation factor 4E (eIF4E) on hepatocellular carcinoma resistance to pirarubicin (THP). In our study, miR-15a-5p expression was increased in THP-treated HepG2 cells. Downregulation of miR-15a-5p blocked cell growth and elevated cell apoptosis of HepG2 cells treated with THP. Moreover, eIF4E was verified as a direct target of miR-15a-5p by binding its 3 ′ -UTR, which was confirmed by luciferase report experiment. Additionally, eIF4E was negatively associated with the miR-15a-5p expression in HepG2 cells. Mechanically, eIF4E was proven as a specific downstream of miR-15a-5p and mediated the effects of miR-15a-5p on cell viability and apoptosis of HepG2 cells treated with THP. These findings supported that miR-15a-5p facilitated THP resistance of hepatocellular carcinoma cells by modulating eIF4E, thus providing an experimental basis that miR-15a-5p might act as a novel diagnostic target in hepatocellular carcinoma resistance to THP.

A series of side-chain-type sulfonated poly(arylene ether ketone)s with high ion exchange capacity (IEC) values were prepared by polycondensation reaction of 4,4′-difluorobenzophenone with 2,2′-bis(3-amino-4-hydroxyphenyl) and bisphenol A, followed by post-grafting reaction using 1,4-butanesultone. For these obtained membranes, sulfoalkylamine functionalized poly(ether ether ketone) (SAm-PEEK)-0.8 with the highest IEC of 3.42 mequiv. g−1 displayed the highest proton conductivity of 0.11 S cm−1 at 25°C and 0.167 S cm−1 at 60°C, respectively. The morphology of these membranes was investigated by transmission electron microscope analysis. The result showed that these membranes exhibited well-connected hydrophilic channels due to their high IEC values and densely populated flexible acid side chains. Owing to their low methanol permeability and high selectivity, SAm-PEEK- x membranes are promising candidates for direct methanol fuel cell applications.

Here, a series of novel poly(ether ether ketone) containing sulfoalkylamine pendant groups (SNPEEK-x) were synthesized by grafting copolymerization reaction. The chemical structure of SNPEEK-x was identified by 1H NMR and the morphology of all films was measured by SAXS and TEM. The impedance varied for five orders of magnitude (from 107 to 102 Ω) as the relative humidity increasing from 11 to 97% RH. At the same time, all samples exhibited a fast response time of less than 3 s, outstanding repeatability and good long-term durability against high humidity. Especially, SNPEEK-x sensors displayed an extremely small humidity hysteresis in the impedance versus RH relationship during absorption and desorption processes. These essential properties of humidity sensors such as the impedance at various humidity, sensitivity, linearity and humidity hysteresis revealed that SNPEEK-x are suitable to be used as humidity sensors.

Infectious hematopoietic necrosis virus (IHNV) is the main pathogen threatening the aquaculture used by the salmonid industry worldwide. Our previous study showed that IHNV infection induced autophagy activation in epithelioma papulosum cyprinid (EPC) cells, but the relationship between IHNV infectivity and autophagy induction had not yet been addressed. To investigate this question, IHNV was inactivated by ultraviolet (UV) irradiation and the complete protein sequence of IHNV glycoprotein was segmented by pepscan into 43 peptides. The induction of autophagy was analyzed by transmission electron microscopy, confocal fluorescence microscopy, flow cytometry, and western blotting. The results show that UV-inactivated IHNV and viral glycoprotein can induce autophagosome formation, obvious punctate clusters of LC3-II and an elevated LC3-II to LC3-I ratio. All these results suggested that UV-inactivated IHNV and viral glycoprotein can induce autophagy independently of viral infectivity. The flow cytometry and western blotting results show that EPC cells treated with peptide p108 displayed an obvious induction of autophagy (LC3-II increased by approximately 2.5-fold). The cells pretreated with peptide p108 showed a significant inhibition of intracellular viral mRNA replication levels and extracellular viral yields of IHNV. These results suggest that peptide p108 could be a promising drug for use in IHNV prevention, and they lay a new foundation for anti-IHNV drug development.

Recent increases in concentrations of chemical oxygen demand (COD-Cr) in Dianchi Lake, China, is an important factor affecting its water quality. Large volumes of cyanobacteria algae have also been recorded in this lake; its growth, distribution and metabolism are believed to directly or indirectly affect water quality. The relationship between metabolism of cyanobacteria and COD-Cr in Dianchi Lake, and the causes of this relationship, are examined in this study. Results show that the increase of COD-Cr concentration is closely related to the metabolism of algae, and that organic substances containing nitrogen and sugars, produced by metabolism, contribute to an increase of COD-Cr to a certain extent. The characteristics of fluorescence spectra of dissolved organic matter (DOM) in the Waihai area of Dianchi Lake are similar to those of algae culture water, and their dominant substances are protein-like substances. Algae release organic substances into water during its growth cycle and extracellular organic substances are mainly released during its normal growth and metabolism stages. Once algae cells enter the decline stage, internal organic matter is released during the dying and decomposition stages, resulting in a distinct increase of COD-Cr. A high concentration of organic matter is present in Dianchi Lake sediments, dominated by native organic matter predominantly derived from aquatic plants and plankton. This finding indicates a potential long-term risk of organic pollutants being released from dead algae cells into the lake. PRACTITIONER POINTS: There is a distinct positive correlation between COD-Cr and Chl-a concentration in Dianchi Lake. Organic substances containing nitrogen and sugars produced by algae metabolism contributed to COD-Cr. The cells die and decompose organic matter content in the water substantially increases, resulting in a distinct increase of COD-Cr. Weight >20 kDa are mainly released into the water body during the decomposition of algae cells after mortality. Organic matter content in the water substantially increases, resulting in a distinct increase of COD-Cr.

The integration circuits are exposing to meet fundamental limits induced by short channel effect Single layer molybdenum disulfide (MoS 2 ) is a promising channel material for field effect transistors (FETs) because the short channel effect is largely reduced. In this paper, a common-source amplifier based on single layer MoS 2 is reported, indicating that single layer MoS 2 is capable to amplify signals. The carrier mobility of the as-made MoS 2 FETs was reached to ∼2.84 cm2/V·s. Furthermore, the output voltage gain of the amplifier is ∼1.3, which can be used as a unify gain amplifier.

A novel strategy that combines the second-order calibration method based on the trilinear decomposition algorithms with high performance liquid chromatography with diode array detector (HPLC-DAD) was developed to mathematically separate the overlapped peaks and to quantify quinolones in honey samples. The HPLC-DAD data were obtained within a short time in isocratic mode. The developed method could be applied to determine 12 quinolones at the same time even in the presence of uncalibrated interfering components in complex background. To access the performance of the proposed strategy for the determination of quinolones in honey samples, the figures of merit were employed. The limits of quantitation for all analytes were within the range 1.2–56.7 μg kg−1. The work presented in this paper illustrated the suitability and interesting potential of combining second-order calibration method with second-order analytical instrument for multi-residue analysis in honey samples.

We first synthesized gadolinium oxide (Gd2O3) by a modified “polyol” strategy and then embedded it into mesoporous silica by a simple self-assembly sol-gel reaction. Scanning electron microscope (SEM) results show that the samples have good sphericity and good dispersibility. The structure of mesoporous silica was characterized by transmission electron microscopy (TEM) and small-angle X-ray diffraction (SAXRD). Results show that the mesoporous structure has not been destroyed after gadolinium oxide imbedding. The ratio of gadolinium and silica was determined by the mean of energy dispersive spectroscopy (EDS).

Molecular imaging has generated a demand for more sensitive contrast agents for magnetic resonance (MR) imaging. We synthesized, by a novel one-step method, Gd(3+) incorporated mesoporous SiO(2) nanoparticles, Gd(2)O(3)@SiO(2), for use as an efficient contrast agent. The prepared nanoparticles were also coated with poly(lactic-co-glycolic acid) (PLGA). The size, morphology, composition and Brunauer-Emmett-Teller specific surface area of the nanoparticles were evaluated. The Gd(2)O(3)@SiO(2) nanoparticles possess intragranular network morphology with a uniform size distribution and an average size of approximately 20-40 nm. The PLGA-coated nanoparticles were spherical or near-spherical in shape with a diameter of approximately 120 nm, a smooth surface, and neither aggregation nor adhesion tendencies. No free Gd ions were detected to dissociate from Gd(2)O(3)@SiO(2) even up to the limit (

Using first-principles calculations, we have discussed the stability of the defect charge state and magnetic properties of V(Ti) defects in anatase TiO(2). While N, F, and Cl are typical nonmetal dopants for photocatalytic activity enhancement of TiO(2), their influence on the magnetism of TiO(2):V is also investigated. We find that V(Ti)(+) (i.e. V(5+)) would be favored in the p-type region and V(Ti)(0) (i.e. V(4+)) and V(Ti)(-) (i.e. V(3+)) would be stable in the n-type region. It is demonstrated that while V(5+) does not carry any local moment, both V(4+) and V(3+) defects are preferred to ferromagnetic ordering. Thus, n-type dopants (such as F and Cl) in TiO(2):V samples, which could stabilize V as V(3+), are suggested for their many applications requiring combined magnetic and optical functionality, while p-type dopants (such as N) are not suggested.

Gd2O3@SiO2 nanoparticles with a core-shell structure are synthesized by pulsed laser ablation in liquid (PLAL) in single steps. A Gd2O3 target immersed in tetraethyl orthosilicate (TEOS) is ablated by a microsecond Nd:YAG laser, which induces the generation of a Gd2O3 plasma plume and pyrolysis of the TEOS. We propose that the moment Gd2O3 nanoparticles are formed they will be coated immediately by SiO2 and directly synthesized Gd2O3@SiO2 core-shell nanoparticles. These particles obtain high r1 relaxivity of 5.26s−1mM−1 and are used as T1-weighted magnetic resonance imaging contrast agents. It is shown that the PLAL technique is promising for fabricating core-shell structure nanomaterial with potential medical applications.

We study the energy transport in the copper nanowire driven by a Z -direction periodic vibration through nonequilibrium molecular-dynamics simulations. It is observed that the energy transport is dependence on the frequency of the periodic vibration. This phenomenon can be explained by the matches between the phonon spectra of the particle and the external vibration. It is suggested that the energy flux flowing through the copper nanowire can be controlled by applying high frequency external driven forces.

The water-adsorptive capabilities of Gd2O3@MCM-41 as contrast agents with various gadolinium additions were evaluated by molecular dynamic simulation, which indicates that increasing gadolinum leads to the decrease in water molecules adsorbed on the surfaces of mesoporous silica and Gd2O3 nanocluster. Gd2O3@MCM-41 nanoparticles were synthesized by a one-step method. The measured microstructure and water-adsorptive capability of Gd2O3@MCM-41 consist with their simulated counterparts. The observation disclosed that the nanoparticles injected within mice were distributed in their liver and tumor. The enhancement of in vivo magnetic resonance imaging was detected in the tumor and inferior vena cava of the mice contrasted with Gd2O3@MCM-41.

The influence of defect charge state on the magnetism of Cu doped ZnO as well as the Cu defects clustering have been investigated by the first-principles calculations. We demonstrate that p-type ZnO:Cu could have ferromagnetic (FM) property, but n-type ZnO:Cu would not have local magnetic moment. Furthermore, the neutral substitutive Cu defects are found to be favorable in clustering, which maintains the FM ordering.