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Background: The occurrence of chemoresistance is a common problem in tumor treatment. Circular RNA (circRNA) has been confirmed to be related to tumor chemoresistance. However, the role and the underlying molecular mechanism of hsa_circ_0004674 in the chemoresistance of osteosarcoma (OS) are still unclear. Methods: The expression of hsa_circ_0004674, miR-342-3p, and fibrillin-1 (FBN1) was determined by qRT-PCR. Cell counting kit 8 assay was used to evaluate the doxorubicin (DXR) resistance of cells. The proliferation and apoptosis of cells were measured using colony formation assay and flow cytometry. Western blot analysis was utilized to examine the protein levels of resistance markers, Wnt/β-catenin pathway markers and FBN1. The interaction between miR-342-3p and hsa_circ_0004674 or FBN1 was confirmed by dual-luciferase reporter assay and RNA pull-down assay. Moreover, animal experiments were performed to assess the effect of hsa_circ_0004674 silencing on the DXR sensitive of OS in vivo. Results: The upregulated hsa_circ_0004674 was found in DXR-resistant OS tissues and cells. Knockdown of hsa_circ_0004674 could inhibit the DXR resistance of OS cells in vitro and promote the DXR sensitive of OS tumors in vivo. In addition, we discovered that hsa_circ_0004674 could sponge miR-342-3p, and miR-342-3p could target FBN1. MiR-342-3p inhibitor could reverse the inhibition effect of hsa_circ_0004674 knockdown on the DXR resistance of OS cells. Similarly, the suppressive effect of miR-342-3p on the DXR resistance of OS cells also could be reversed by FBN1 overexpression. Furthermore, we revealed that hsa_circ_0004674 silencing inhibited the activity of Wnt/β-catenin pathway by the miR-342-3p/FBN1 axis. Conclusion: Hsa_circ_0004674 facilitated the DXR resistance of OS through Wnt/β-catenin pathway via regulating the miR-342-3p/FBN1 axis, suggesting that hsa_circ_0004674 was a promising target for the chemoresistance of OS. [ABSTRACT FROM AUTHOR]

Rationale: Tetrahydropiperine is one of the natural arylpentanamide compounds isolated from Piper nigrum L., which has been demonstrated to have insecticidal activity. The aim of this study was to investigate the metabolic profiles of tetrahydropiperine in mouse, rat, dog, monkey and human hepatocytes. Methods: The in vitro metabolism of tetrahydropiperine was elucidated via incubation with hepatocytes for 2 h at 37°C. The samples were analyzed using ultrahigh‐performance liquid chromatography combined with diode‐array detection and high‐resolution tandem mass spectrometry operated in positive electrospray ionization mode. The structures of the metabolites were characterized using their retention times and their tandem mass spectrometric product ions. Results: A total of 20 metabolites were detected and their structures were proposed. These metabolites were formed mainly through the following pathways: (1) 1,3‐benzodioxole ring opening to form a catechol derivative (M12), which was prone to glucuronidation (M6 and M8), methylation (M17) and glutathione (GSH)‐derived conjugation through an ortho‐quinone intermediate (M4) or via an aldehyde intermediate (M7); (2) dehydrogenation to form a piperanine (M15), which was subsequently subject to hydroxylation (M2 and M5) and GSH conjugation (M10 and M11) via Michael addition; (3) hydroxylation (M13, M14, M16, M18 and M19); and (4) direct GSH conjugation through an aldehyde intermediate (M3). Conclusions: The major metabolic pathways of tetrahydropiperine were hydroxylation, dehydrogenation, methylation, GSH conjugation and glucuronidation. Tetrahydropiperine was bioactivated through ortho‐quinone, Michael receptor and aldehyde intermediates. [ABSTRACT FROM AUTHOR]

This Letter presents a methodology, which contains resistive‐reactive series of continuous inverse modes (Res.‐Rea. SCIMs), for the second octave power amplifier (PA) design. The bandwidth was extended by multiplying the current waveform of SCIMs with a cosine factor. The measurement of the proposed Res.‐Rea. SCIMs PA showed 67–78.8% drain efficiency and ∼10 W output power across a band of 0.5–2 GHz. [ABSTRACT FROM AUTHOR]

Herein, three new coordination polymers (CPs), namely {Ni (4,4′-abpt)(2,5-fdca)H2O]n (1), [Co(4,4′-abpt)(2,5-fdca)H2O]n (2) and [Co(4,4′-abpt)(1,3-abc)]n (3) {4,4′-abpt = 3,5-di-4-pyridinyl-4H-1,2,4-triazol-4-amine, 2,5-fdca2− (the fully deprotonated forms of 2,5-furandicarboxylic acid), 1,3-abc2− (the fully deprotonated forms of 1,3-adamantanedicarboxylic acid)} were synthesized under solvothermal conditions and were characterized by elemental analysis, thermogravimetric analysis, powder X-ray diffraction, and single crystal X-ray diffraction (1 and 3) techniques. Structural analyses revealed that 1 is a two-dimensional structure with quadrilateral holes, while 3 is a two-dimensional rhombus network configuration with a binuclear metal center. Three as-prepared compounds exhibited efficient photocatalytic performance for the degradation of organic dyes of crystal violet (CV), methylene blue (MB), and rhodamine B (Rh-B) under UV irradiation, among which, 1 exhibited the best photocatalytic activity with a percentage degradation of more than 96% for the three dyes in 30 min. In addition, in the free radical capture experiment involving 3, it was found that both, the hydroxyl radical OH˙ and superoxide radical (˙O2−) were involved in the degradation process of dyes, among which, the OH˙ radical is the main species to trigger the photocatalytic degradation experiment. Finally, the electrocatalytic performance of the catalysts was investigated in 1 M alkaline KOH solution, and the results showed that all three catalysts had certain electrocatalytic performance, and the catalytic performance of 1 was slightly better than that of 2 and 3. It exhibited a low overpotential of 367 mV at a current density of mA cm−2. [ABSTRACT FROM AUTHOR]

Four new coordination polymers, including 1D, 2D and 3D structures, were synthesized via a hydrothermal method using Cd2+/Zn2+/Cu2+ metal salts as nodes. These polymers were formed through self‐assembly of four different dicarboxylic acid ligands, namely adamantane‐1,3‐dicarboxylic acid (H2adc), glutaric acid (H2glu), 5‐hydroxyisophthalic acid (H2hip) and fumaric acid (H2fum), in conjunction with the auxiliary ligand [1,4‐bis(pyridin‐4‐ylmethyl)piperazine (bpmp). The corresponding formulae are [Cd3(adc)2(bpmp)Cl2(H2O)2]n (1), {[Cd2(glu)2(bpmp)2(H2O)2]·8H2O·2CH3OH}n (2), [Zn(hip)(bpmp)(H2O)]n (3) and [Cu(fum)(bpmp)(H2O)2]n (4). Single‐crystal X‐ray diffraction studies revealed that the Cd2+ centers in complex 1 all adopt a six‐coordinate mode but two distinct {CdO2N2Cl2} and {CuO5Cl} units. The 3D network of complex 1 can be simplified to a binodal (4.6)‐connected underlying net with the point symbol (3·42·5·62)4(32·62·72·88·10). Each Cd2+ cation in complex 2 adopts a seven‐coordinate {CdO5N2} center, forming an asymmetric pentagonal bipyramidal coordination. Its stacking structure is formed by the interaction of hydrogen bonds between 2D supramolecular layers, with the adjacent layers exhibiting mirror symmetry. Each Zn2+ ion in complex 3 displays a {ZnO3N} four‐coordinate unit. Its stacking structure is formed by one‐dimensional [Zn(hip)(bpmp)(H2O)]n chains connected through hydrogen bonds. On the other hand, complex 4 features a Jahn–Teller distorted {CuO4N2} octahedral coordination. Subsequently, the thermal stability of these complexes was investigated. The solid‐state fluorescence spectroscopy was employed to analyze complexes 1, 2 and 3. Additionally, a Hirshfeld surface analysis was performed on complex 3. [ABSTRACT FROM AUTHOR]

Background: Noncoding RNAs such as circular RNAs (circRNAs) are abundant in the human body and influence the occurrence and development of various diseases. Non-small cell lung cancer (NSCLC) is one of the most common malignant cancers. Information on the functions and mechanism of circRNAs in lung cancer is limited; thus, the topic needs more exploration. The purpose of this study was to identify aberrantly expressed circRNAs in lung cancer, unravel their roles in NSCLC progression, and provide new targets for lung cancer diagnosis and therapy. Methods: High-throughput sequencing was used to analyze differential circRNA expression in patients with lung cancer. qRT‒PCR was used to determine the level of circHERC1 in lung cancer tissues and plasma samples. Gain- and loss-of-function experiments were implemented to observe the impacts of circHERC1 on the growth, invasion, and metastasis of lung cancer cells in vitro and in vivo. Mechanistically, dual luciferase reporter assays, fluorescence in situ hybridization (FISH), RNA immunoprecipitation (RIP) and RNA pull-down experiments were performed to confirm the underlying mechanisms of circHERC1. Nucleocytoplasmic localization of FOXO1 was determined by nucleocytoplasmic isolation and immunofluorescence. The interaction of circHERC1 with FOXO1 was verified by RNA pull-down, RNA immunoprecipitation (RIP) and western blot assays. The proliferation and migration of circHERC1 in vivo were verified by subcutaneous and tail vein injection in nude mice. Results: CircHERC1 was significantly upregulated in lung cancer tissues and cells, ectopic expression of circHERC1 strikingly facilitated the proliferation, invasion and metastasis, and inhibited the apoptosis of lung cancer cells in vitro and in vivo. However, knockdown of circHERC1 exerted the opposite effects. CircHERC1 was mainly distributed in the cytoplasm. Further mechanistic research indicated that circHERC1 acted as a competing endogenous RNA of miR-142-3p to relieve the repressive effect of miR-142-3p on its target HMGB1, activating the MAPK/ERK and NF-κB pathways and promoting cell migration and invasion. More importantly, we found that circHERC1 could bind FOXO1 and sequester it in the cytoplasm, adjusting the feedback AKT pathway. The accumulation of FOXO1 in the cytosol and nuclear exclusion promoted cell proliferation and inhibited apoptosis. CircHERC1 is a new circRNA that promotes tumor function in NSCLC and may serve as a potential prognostic biomarker and therapeutic target for NSCLC. Conclusions: CircHERC1 is a new circRNA that promotes tumor function in NSCLC and may serve as a potential diagnosis biomarker and therapeutic target for NSCLC. Our findings indicate that circHERC1 facilitates the invasion and metastasis of NSCLC cells by regulating the miR-142-3p/HMGB1 axis and activating the MAPK/ERK and NF-κB pathways. In addition, circHERC1 can promote cell proliferation and inhibit apoptosis by sequestering FOXO1 in the cytoplasm to regulate AKT activity and BIM transcription. [ABSTRACT FROM AUTHOR]

Four new coordination frameworks with formulas of {[Co(fdca)(4-bpmp)(H2O)2]·2H2O}n (1), {[Ni(fdca)(4-bpmp)(H2O)2]·2H2O}n (2), [Co(tdca)(4-bpmp)(H2O)]n (3) and [Co(fuma)(4-bpmp)(H2O)2]n (4) [4-bpmp = bis (4-pyridylmethyl)piperazine, fdca = 2,5-furandicarboxylic acid, tdca = 2,5-thiophenedicarboxylic acid, fuma = fumaric acid] have been synthesized and structurally characterized by elemental analysis, single-crystal X-ray diffraction analysis and thermogravimetric analysis. Complex 3 exhibits a 4-connected sqc6 uninodal 3D structure with point symbol of {66}, while the other three complexes all exhibit mutually inclined 2D + 2D → 3D interpenetration structures. The magnetic properties reveal that complex 1, 2, and 4 show the antiferromagnetic exchange interaction behavior. An observed difference in structure and magnetic behavior in complex 3 is driven by coordination types of carboxylate building blocks and the final structure. Magnetic study indicates the magnetic-exchange coupling not only depends on the nature of the metal centers but the structure of the metal–organic framework can affect the magnetic. And then, the UV–Vis DRS properties of four complexes were also investigated. [ABSTRACT FROM AUTHOR]

WLY-0, as an α -D-glucan with a molecular weight (Mw) of 11.12 kDa, was successfully isolated and purified from Huangshui (HS). The results of methylation and NMR indicated that the mainchain of WLY-0 was (1 → 4)- α -D-glucan, with side chains linking at O-6. Meanwhile, the surface morphology characterization showed that WLY-0 had an irregular flake-like morphology with a rough and uneven surface and varies in sizes from nanometers to microns. Furthermore, WLY-0 relieved the increased paracellular permeability of FD4 and decreased TEER challenged by LPS, meanwhile inhibited the production of pro-inflammatory cytokines (TNF- α , IL-6, and IL-1 β) and up-regulated the expression of TJ protein (Occludin, Claudin-1, ZO-1, and JAM-A) in Caco-2 cells, so to improve the intestinal barrier function. Our findings about the structural characteristics and biological activities of WLY-0 provided a scientific foundation for the utilization of HS as a potent source of an effective adjuvant in intestinal barrier injury treatment. [Display omitted] • A polysaccharide WLY-0 extracted from Huangshui , was identified as a α -D-glucan. • WLY-0 contains (1 → 4)- α -D-glucan in backbone, with side chains linking at O-6. • WLY-0 had an irregular flake-like morphology with a rough and uneven surface. • WLY-0 reversed LPS induced low TEER value and high FITC-dextran flux. • WLY-0 showed obvious intestinal barrier protective effect in vitro. [ABSTRACT FROM AUTHOR]

A novel two-dimensional Co-MOF material {[Co(dptz)2(oba)2]·(DMF)2}n is prepared using mixed organic ligands, which exhibits both OER (oxygen evolution reaction) and HER (hydrogen evolution reaction) catalytic performance. The integration of an Fe dopant and amorphous interface into Co-MOF to improving the electrocatalytic performance of pristine MOFs (metal–organic frameworks) is demonstrated and the origin of the remarkable electrocatalytic performance of the catalyst is elucidated. The comprehensive characterization data of Fe@Co-MOFs illustrate that there is a crystallinity transition during the doping of Co-MOF, which increases the electron transfer rate of the material and ensures increased exposure of the ligand unsaturated active site on the surface, and modulates the electronic structure of the Co center in a synergistic manner. As a result, the optimized catalytic Fe@Co-MOF-3 with an amorphous structure exhibits outstanding electrocatalytic performance for the OER, with only 248 mV at a current density of 50 mA cm−2 and excellent stability after 11 h of testing in alkaline solution. Not only that, the HER was achieved with a low overpotential of 150 mV at 10 mA cm−2. The present work indicates that the as-synthesized Co-MOF and Fe@Co-MOFs offer prospects in developing electrocatalysts for water splitting. [ABSTRACT FROM AUTHOR]

Three new metal–organic coordination polymers, {[Co2(TDC)2(H-3,3′-pytz)2(μ2-OH)]·4DMF}n (1), [Mn5(NDC)4(3,3′-pytz)(DMF)4(μ3-OH)2]n (2), [Co5(NDC)4(3,3′-pytz)(DMF)4(μ3-OH)2]n (3). (3,3′-pytz = 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine; H-3,3′-pytz = protonated 3,6-bis(3-pyridyl)-1,2,4,5-tetrazine; H2TDC = 2,5-Thiophenedicarboxylic acid; H2NDC = 1,4-naphthalenedicarboxylic acid) were synthesized under hydro-/solvothermal conditions and characterized by techniques of single-crystal X-ray diffraction analysis, elemental analysis, infrared spectra (IR) and thermogravimetric analysis (TGA). The resulting analyses demonstrate that complex 1 displays a rare 3D 8-connected bcu framework with the point symbol of {424·64} based on dinuclear [Co2(μ2-OH)(COO)4] cluster, while complex 2 and 3 possessed a rare 3D 10-connected pentanuclear-cluster-based ile{36·434·53·62}framework. The variable-temperature magnetic susceptibility data show that the complex 1, 2 and 3 exhibit antiferromagnetic interaction. [ABSTRACT FROM AUTHOR]

Huangshui (HS), a typical by-product of traditional Chinese Baijiu, has attracted more and more attention since its rich resources of polysaccharides. However, there's little information on hydrogels preparation by Huangshui polysaccharides (HSPs). A series of novel HSP-loaded hydrogels were synthesized using crude HSP (cHSP), polyvinyl alcohol (PVA), sodium carboxyl methyl cellulose (CMC), and in situ incorporation of Fe 3 O 4 for methylene blue (MB) adsorption for the first time. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM) and texture tests indicated the paramagnetic hydrogels with porous structure were formed via physical crosslinking, and cHSP had no effect on hydrogel texture. Notably, cHSP enhanced the swelling capacity and MB adsorption ability of the hydrogels, and the corresponding maximum value was 38.67 g/g and 71.07 mg/g, respectively, when the additive amount of cHSP to the hydrogels was 2 % at 25°С. In addition, the swelling kinetics of hydrogels followed the Schott's second-order kinetics model, while MB adsorption fitted well with the Freundlich isotherm and pseudo-second-order model. Furthermore, intraparticle and film diffusion-controlled MB adsorption process. Significantly, cHSP amount could counteract the negative influence of high temperature on MB adsorption, and the prepared hydrogels could be reusable, demonstrating cHSP effectively promoted the properties of hydrogels and had potential application in MB removal. The adsorption mechanism of MB onto the hydrogels involved ion-exchange, hydrogen bonding, electrostatic interaction, and chemical reaction according to the above results together with the analysis by X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray (EDX) characterizations, thermodynamic, etc. [Display omitted] [ABSTRACT FROM AUTHOR]

Cu and Mn co-doped LiNbO 3 films were deposited on Si (111) substrates by rf-magnetron sputtering. XRD shows a randomly oriented polycrystalline R3C structure of LiNbO 3 was formed in the films annealed at 1000 °C for 1 h in air. XPS and XAFS determine that Mn 2+ substitutes on the Li site with a Li vacancy and Cu 2+ substitutes on the Nb site with an oxygen vacancy in the LiNbO 3 lattice. SQUID measurements indicate that all the films exhibit room temperature ferromagnetism, attributed to a strong d–d electron interaction between Mn and Nb and the bound magnetic polarons resulting from the oxygen vacancies. The saturated magnetization increases but the atom magnetic moment decreases with increasing Cu content in the films. The drop of the atom magnetic moment may arise from the antiferromagnetic coupling among adjacent Cu ions and an antiparallel configuration between Cu 2+ ions and their trapped electrons. [ABSTRACT FROM AUTHOR]

The SiC/Cu nano-multilayer films were deposited on Si substrates using radio frequency and direct current alternative sputtering technique. In this paper, the transport and magnetic properties of the films were investigated. XRR shows the SiC/Cu periodical structures of the films. XRD confirms that the 3C-SiC crystal structure is formed in the films without heating substrates. The XPS indicates that the Cu atoms substitute for Si sites of the SiC lattice and exist in a mixed valance state of Cu + and Cu 2+ . The best fitting for the plots of ln ρ versus T −1/4 using the combination of the Mott and the band gap VRH models suggests that the carriers in the films are strongly localized. The films have a typical semiconductor characteristic and an obvious room temperature ferromagnetism which should arise from the bond magnetic polarons. The maximum values of saturation magnetization and carrier concentration are up to 15.2 emu/cm 3 and 1.86E + 22/cm 3 respectively. [ABSTRACT FROM AUTHOR]