miR-484/MAP2/c-Myc-positive regulatory loop in glioma promotes tumor-initiating properties through ERK1/2 signaling

Glioma is the most common intracranial malignant tumor. Cancer stem cells (CSCs) are resistant to chemotherapy and radiotherapy, and are closely related to cancer metastasis and recurrence. In this study, we aimed to explore the effect of miR-484 on glioma stemness and the underlying mechanism involved. miR-484 enhanced glioma tumor-initiating properties in vitro and in vivo. Moreover, miR-484 was shown to directly target MAP2, resulting in activation of ERK1/2 signaling and promotion of stemness in glioma. The ERK1/2 signaling facilitated the formation of a miR-484/MAP2/c-Myc positive feedback loop in glioma. High miR-484 expression predicted a poor prognosis for glioma patients, and high MAP2 expression predicted a good prognosis for glioma patients. Low miR-484 expression and high MAP2 expression was associated with the best prognosis in glioma. Our study suggests that miR-484 and MAP2 can be utilized as predictors for the clinical diagnosis and prognosis of glioma, and miR-484 and MAP2 are potential targets for the treatment of glioma.     

Design and Analysis of Ultra Broadband Nano-absorber for Solar Energy Harvesting

In this paper, we propose a metamaterial based ultra broadband nano-absorber (UBNA) for solar energy harvesting, whose elements consist of a ring column and dual hexagon pillar at the center. In this absorber, the light of shorter wavelengths is harvested at ring column, while the light of longer wavelengths is trapped by dual hexagon pillar. It is found that the average absorptivity of the UBNA is as high as 96% in 300–1300 nm waveband and the UBNA can maintain 95% in the whole visible and near-infrared waveband ranging from 300 to 2000 nm. In addition, the perfect light absorbing capability of the UBNA is independent of the incident light polarization state in the waveband of 300–1300 nm, and it can keep up an average absorptivity of 91% with an large incident angle varying between ?60^° and 60^°. We attribute the perfect absorbing property of UBNA to the synergistic effect of the slow wave effect, Fabry-Perot resonance and the localized surface plasmon resonance enhancement.     

Design,characterization, and in vitro antiproliferative efficacy of gemcitabine conjugates based on carboxymethyl glucan

Gemcitabine (GEM) is widely used in clinical practice in the treatment of cancer and several other solid tumors. Nevertheless, the antitumor effect of GEM is partially prevented by some limitations including short half life, and lack of tumor localizing. Carboxymethyl glucan (CMG), a carboxymethylated derivative of β-(1-3)-glucan, shows biocompatibility and biodegradability as well as a potential anticarcinogenic effect. To enhance the antiproliferative activity of GEM, four water soluble conjugates of GEM bound to CMG via diverse amino acid linkers were designed and synthesized. ¹H NMR, FT IR, elementary analysis and RP-HPLC chromatography were employed to verify the correct achievement of the conjugates. In vitro release study indicated that conjugates presented slower release in physiological buffer (pH 7.4) than acidic buffer (pH 5.5) mimicking the acidic tumor microenvironment. Moreover, A549, HeLa and Caco-2 cancer cell lines were used to evaluate the in vitro cytotoxicity of conjugates and the results showed that binding GEM to CMG significantly enhanced antiproliferative activity of GEM on A549 cells. Therefore, these conjugates may be potentially useful as a delivery vehicle in cancer therapy and worthy of further study on structure-activity relationship and antiproliferative activity in vitro and in vivo, especially for lung tumor.     

Biosynthesis of gold nanoparticles using cell-free extracts of Magnusiomyces ingens LH-F1 for nitrophenols reduction

Bioprocess and Biosystems Engineering - A green and eco-friendly method for the synthesis of gold nanoparticles (AuNPs) was developed using the cell-free extracts of a yeast strain Magnusiomyces...     

New species and records of orbiliaceous fungi from Georgia,USA

Orbilia georgiana and O. renispora are described as new species to science, in addition, O. eucalypti, O. occulta, and O. xanthoguttulata are reported based on collections taken from the state of Georgia, USA. Orbilia xanthoguttulata is a new record for North America. The morphology of all species is described based on both sexual and asexual morphs. Asexual morphs were obtained from ascospore isolates, from which also DNA was extracted and used to amplify rDNA genes (ITS and LSU) for phylogenetic comparison.     

Photosynthetic characteristics of leaves and fruits of Hickory (<Emphasis Type="Italic">Carya cathayensis</Emphasis> Sarg.) and Pecan (<Emphasis Type="Italic">Carya illinoensis</Emphasis> K.Koch) during fruit development stages

Key message

Fruit photosynthesis in both hickory and pecan significantly contribute to the carbon requirements of late growth stage (corresponding to seed development).

Abstract

Plant parts other than leaves can perform photosynthesis and contribute to carbon acquisition for fruit development. To determine the role of fruit photosynthesis in fruit carbon acquisition in hickory (Carya cathayensis Sarg.) and pecan (Carya illinoensis K.Koch), we studied changes in dry mass, surface area and CO₂ exchange rate in these fruits during fruit development. Fruit development was divided into two phases: phase one involves the rapid increase of fruit size (from 0 to 59 days after pollination (DAP) for hickory; from 0 to 88 DAP for pecan); phase two involves seed development (from 59 to 121 DAP for hickory; from 88 to 155 DAP for pecan). The net photosynthetic rate (P _n) in hickory leaves decreased by 48.5 % from 76 to 88 DAP, while the P _n in pecan leaves decreased by 32.3 % from 88 to 123 DAP. The gross photosynthetic rate (P _g) in hickory fruit was significantly greater than that of the leaf during the late stage (88 to 121 DAP) of fruit development. Pecan fruit had a significantly higher P _g than leaves during ontogeny. The contribution of fruit photosynthesis to fruit carbon requirements increased during fruit development, which was estimated by the gross fruit photosynthesis divided by respiration and increased dry mass. The contribution of fruit photosynthesis to pecan carbon requirements was significantly greater than that of hickory. Fruit photosynthesis in both hickory and pecan significantly contribute to the carbon requirements of late growth stage.

     

Novel Alginate Lyase (Aly5) from a Polysaccharide-Degrading Marine Bacterium,Flammeovirga sp. Strain MY04: Effects of Module Truncation on Biochemical Characteristics,Alginate Degradation Patterns,and Oligosaccharide-Yielding Properties

Alginate lyases are important tools for oligosaccharide preparation, medical treatment, and energy bioconversion. Numerous alginate lyases have been elucidated. However, relatively little is known about their substrate degradation patterns and product-yielding properties, which is a limit to wider enzymatic applications and further enzyme improvements. Herein, we report the characterization and module truncation of Aly5, the first alginate lyase obtained from the polysaccharide-degrading bacterium Flammeovirga. Aly5 is a 566-amino-acid protein and belongs to a novel branch of the polysaccharide lyase 7 (PL7) superfamily. The protein rAly5 is an endolytic enzyme of alginate and associated oligosaccharides. It prefers guluronate (G) to mannuronate (M). Its smallest substrate is an unsaturated pentasaccharide, and its minimum product is an unsaturated disaccharide. The final alginate digests contain unsaturated oligosaccharides that generally range from disaccharides to heptasaccharides, with the tetrasaccharide fraction constituting the highest mass concentration. The disaccharide products are identified as ΔG units. While interestingly, the tri- and tetrasaccharide fractions each contain higher proportions of ΔG to ΔM ends, the larger final products contain only ΔM ends, which constitute a novel oligosaccharide-yielding property of guluronate lyases. The deletion of the noncatalytic region of Aly5 does not alter its M/G preference but significantly decreases the enzymatic activity and enzyme stability. Notably, the truncated protein accumulates large final oligosaccharide products but yields fewer small final products than Aly5, which are codetermined by its M/G preference to and size enlargement of degradable oligosaccharides. This study provides novel enzymatic properties and catalytic mechanisms of a guluronate lyase for potential uses and improvements.     

Manipulating Magnetoinductive Coupling with Graphene-Based Plasmonic Metamaterials in THz Region

Coupling between physical modes can trigger some new physical phenomena such as frequency shift, new mode, and Rabi splitting. Resonant modes in graphene-based metamaterials provide a new platform for the research of coupling. In this work, we demonstrate that the plasmonic coupling of split ring resonator (SRR) dimer in graphene-based metamaterials can be easily manipulated. This magnetoinductive coupling can switch on/off the dark modes easily, which is usually done by symmetry-breaking structure previously. Furthermore, the dark mode can also be activated by Fermi energy as well as carrier concentration changing with either physical or chemical methods conveniently. In addition, different graphene-based SRR dimer configurations present different coupling strengths, which benefits the designing and optimizing of graphene-based metamaterials. The demonstration could enhance the versatility of both coupling studies in terahertz (THz) region and graphene-based metamaterials for THz devices.