97 research outputs found

    Selective Adsorption and Separation of (−)-Epigallocatechin Gallate (EGCG) based on Silica Gel Surface Molecularly Imprinted Polymers

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    AbstractTo separate and enrich EGCG from a mixture of tea catechins, the molecular imprinted polymers (MIPs) were synthesized on silica gel by surface molecular imprinting technique and characterized with Fourier transform infrared spectroscopy (FT-IR), elemental analysis and scanning electronic microscopy (SEM). MIPs exhibited favorable recognition, better selectivity for EGCG than the other monomers, and the descending order was EGCG, (+)-catechin (C), (−)-epicatechin (EC), (−)-epigallocatechin (EGC), (−)-catechin gallate (CG) and (−)-gallocatechin gallate (GCG). These results demonstrated that MIPs could realize the separation and enrichment of EGCG in real sample

    1-(2-Hy­droxy-3,5-dimeth­oxy­phen­yl)ethanone

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    In title compound, C10H12O4, all of the non-H atoms lie approximately in a plane with the largest deviation being 0.061 (2) Å. An intra­molecular O—H⋯O hydrogen bond generates an S(6) ring motif. No classical inter­molecular hydrogen bonding occurs, with only van der Waals forces stabilizing the crystal structure

    C1ql4 regulates breast cancer cell stemness and epithelial-mesenchymal transition through PI3K/AKT/NF-κB signaling pathway

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    BackgroundThe stemness characteristic of breast cancer (BC) is a crucial factor underlying cancer recurrence and metastasis after operative therapy and chemoradiotherapy. Understanding the potential mechanism of breast cancer stem cells (BCSCs) may ameliorate the prognosis of patients.MethodsWe collected clinical specimens of BC patients for staining and statistical analysis to verify the expression status and clinical significance of complement C1q-like 4 (C1ql4). Western blot and qRT-PCR were employed to detect the expression of molecules. Flow cytometry was used to examine cell cycle, cell apoptosis and the portion of BCSCs. Wound healing and Transwell assays were used to detect cell metastasis. The effect of C1ql4 on breast cancer progression in vivo was examined in a nude mouse tumor bearing model.ResultsOur clinical analysis showed that C1ql4 was highly expressed in BC tissues and cell lines, and the high expression of C1ql4 was significantly corelated with the malignancy of BC patients. Moreover, we also found that C1ql4 was overexpressed in BCSCs. C1ql4 knockdown suppressed the BCSC and EMT properties, promoted cell cycle progression, enhanced BC cell apoptosis, and inhibited cell migration and invasion, whereas the C1ql4 overexpression exhibited the opposite effects. Mechanistically, C1ql4 promoted the activation and nuclear location of NF-κB and the expression of downstream factors TNF-α and IL-1β. Moreover, inhibition of PI3K/AKT signaling suppressed the C1ql4-induced stemness and EMT.ConclusionsOur findings suggest that C1ql4 promotes the BC cell stemness and EMT via modulating the PI3K/AKT/NF-κB signaling, and provides a promising target for BC treatment

    Xuetonglactones A–F: Highly Oxidized Lanostane and Cycloartane Triterpenoids From Kadsura heteroclita Roxb. Craib

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    © Copyright © 2020 Shehla, Li, Cao, Zhao, Jian, Daniyal, Wahab, Khan, Liao, Rahman, Choudhary and Wang. Xuetonglactones A–F (1–6), six unreported highly oxidized lanostane- and cycloartane-type triterpenoids along with 22 known scaffolds (7–28) were isolated from the stems of Kadsura heteroclita (Roxb.) Craib. Compared with previous congeners, xuetonglactone A (1), possesses an unprecedented 20,21-α-epoxide, and xuetonglactone D (4) features an unusual 19-α-hydroperoxyl moiety. The structures and the absolute configurations of the compounds were established by extensive one- and two-dimensional NMR, and electronic circular dichroism (ECD) spectroscopic analysis, with those of 1 and 5 confirmed by single-crystal X-ray diffraction technique. Compounds 1 and 2 exhibited inhibition of iNOS activity in LPS-induced macrophages with IC50 values of 22.0, and 17.0 μg/mL, respectively. While compounds 6, 7, 8, and 24 showed potent cytotoxic activities against human cervical cancer cell lines (HeLa) with the IC50 values of 4.0, 5.8, 5.0, and 6.4 μM, and against human gastric cancer cells (BGC 823) with the IC50 values of 2.0, 5.0, 2.5, and 2.0 μM, respectively. Moreover, plausible biogenetic pathways of (1–6) were also proposed

    The Preparation, Antioxidant Activity Evaluation, and Iron-Deficient Anemic Improvement of Oat (Avena sativa L.) Peptides–Ferrous Chelate

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    Iron-chelating peptides have been widely considered as one of the best iron supplements to alleviate the iron deficiency. In this study, a novel oat peptides–ferrous (OP-Fe2+) chelate was prepared from antioxidant oat peptides obtained in the laboratory of the authors. The optimal preparation condition was obtained through the single-factor and response surface methodology, and the chelating rate could reach up to 62.6%. After chelation, the OP-Fe2+ chelate exhibited a significantly higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity than oat peptides. It was discovered that the hemoglobin concentration and the number of red blood cell levels in OP-Fe2+-treated iron-deficient anemic (IDA) rats were significantly higher than untreated IDA rats. The OP-Fe2+ chelate could also improve the hypertrophy of the spleen, serum iron (SI), total iron and binding capacity, and serum ferritin levels in the IDA rats. In addition, the OP-Fe2+ treatment significantly increased the antioxidant activities of super oxidase and glutathione in the liver homogenate of the IDA rats. Therefore, the OP-Fe2+ chelate is an effective type of iron supplement for IDA rats, which could be a promising source with anti-anemia and antioxidant activity

    QTL Mapping of Six Spike and Stem Traits in Hybrid Population of Agropyron Gaertn. in Multiple Environments

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    Most Agropyron Gaertn. species are excellent sources of forage. The derivative lines of wheat-Agropyron cristatum show elite agronomic traits, and some are valuable for wheat breeding. The species of Agropyron Gaertn. was mainly recognized by the spike morphology in traditional taxon. Six traits, including spike length (SL), ear stem length (ESL), the second internodes length (SIL), spikelet number per spike (SNS), floret number per spikelet (FNS), and grain number per spikelet (GNS), are vital to morphology studies and also influences the forage crop yield. To elucidate the genetic basis of spike and stem traits, a quantitative trait locus (QTL) analysis was conducted in a cross-pollinated (CP) hybrid population derived from a cross between two diverse parents, Agropyron mongolicum Keng Z2098 and A. cristatum (L.) Gaertn. Z1842, evaluated across three ecotopes (Langfang, Changli, and Guyuan of Hebei, China) over 3 years (from 2014 to 2016). Construction of a high-density linkage map was based on 1,023 single-nucleotide polymorphism (SNP) markers, covering 907.8 cM of the whole Agropyron genome. A total of 306 QTLs with single QTL in different environments explaining 0.07–33.21% of the phenotypic variation were detected for study traits. Seven major-effect QTLs were identified, including one for ESL on chromosome 3, one for SIL on chromosome 5, three for SL (two on chromosome 2 and one on chromosome 4), and two for SNS on chromosomes 3 and 7. Also, seven stable QTLs, including four for ESL, one for SL, one for GNS, and one for FNS, were mainly mapped on chromosomes 2, 3, 4, 5, and 7, respectively, elucidating 0.25–14.98% of the phenotypic variations. On the use of Agropyron CP hybrid population to identify QTL determining spike and stem traits for the first time, these QTLs for six traits would provide a theoretical reference for the molecular marker-assisted selection in the improvement of forage and cereal crop species

    Robust vibration control of uncertain flexible structures based on model reduction

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    This paper considers robust vibration control of uncertain flexible structures. It firstly uses finite element method (FEM) to formulate the model and then reduces the degrees of freedom by employing mode truncation method. It compares the control effects of different number of modes reserved, and presents the principle of determining the number of modes truncated. Then it chooses the number and optimal place of actuators by using genetic algorithm (GA). Taking into account uncertainties which are caused by model parameter variations, a robust controller is designed to suppress the vibration of the flexible structure. The effectiveness of the methods is illustrated through numerical simulations. ? 2014 TCCT, CAA.EI

    Modelling the Nanomechanical Responses of Biofilms Grown on the Indenter Probe

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    Biofilms have a profound impact on the environment, human health and industrial systems. In order to manage and control them, it is important to measure their mechanical properties intact. Therefore, it has been proposed to grow the biofilms on the atomic force microscope prior to nanoindentation tests with the same probe. However, for nanoindentation of biofilm grown on spherical indenter itself, the existing nanoindentation models become invalid. Therefore, modified models have been proposed to describe the nanoindentation response of biofilm grown on a sphere based on finite element modelling. It was found that the applicability of the models depends on the biofilm thickness and constitutive mechanical models adopted for biofilms. The models developed here would enable more reliable determination of viscoelastic properties of biofilms that grow intact on the indenter itself

    Anti-saturation control and control allocation for hypersonic vehicles with reaction jets

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    In this paper, a new method is proposed for the controlling of hypersonic vehicles in exoatmospheric flight with reaction jets, which can only provide a single finite value of control. A control allocation based on linear programming is designed to minimize the difference between a desired moment and the one produced by a reaction jet. An anti-saturation control law is presented to limit the norm of the desired control input, which considers the system uncertainty and maximizes the domain of attraction. The effectiveness of the method is illustrated through numerical simulations. ? 2014 TCCT, CAA.EI
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