Direct Ethanol Production from Lignocellulosic Sugars and Sugarcane Bagasse by a Recombinant Trichoderma reesei

Trichoderma reesei can be considered as a candidate for consolidated bioprocessing (CBP) microorganism. However, its ethanol yield needs to be improved significantly. Here the ethanol production of T. reesei CICC 40360 was improved by genome shuffling while simultaneously enhancing the ethanol resistance. The initial mutant population was generated by nitrosoguanidine treatment of the spores, and an improved population producing more than fivefold ethanol than wild type was obtained by genome shuffling. The results show that the shuffled strain HJ48 can efficiently convert lignocellulosic sugars to ethanol under aerobic conditions. Furthermore, it was able to produce ethanol directly from sugarcane bagasse, demonstrating that the shuffled strain HJ48 is a suitable microorganism for consolidated bioprocessing

Synthesis of polyacrylamide-based aerosol fixative and its fixation effect on tellurium aerosol

The removal control of radioactive aerosols in a nuclear emergency is an important issue, and capture fixation is a parameter for studying the purification effect of aerosol fixatives on aerosols. Herein, PAM-g-PAA, PAM-g-PHEA, and PAM-g-PAA/PHEA were obtained by chemical grafting with polyacrylamide as the substrate, acrylic acid and 2-hydroxyethyl acrylate as grafting monomers. The grafting product was confirmed by infrared spectroscopy and the grafting rate was calculated. The microstructure of different products were compared and discussed by scanning electron microscope images of freeze-drying and film formation. The capture and sedimentation effects of tellurium (simulated polonium) aerosol were studied by surface tension and fixed sedimentation experiments (PAM, PAM-g-PAA, PAM-g-PHEA, PAM-g-PAA/PHEA aqueous solution), and the mechanism of aerosol fixation was discussed. The results showed that the surface tension of the grafted product was significantly lower than that of the substrate PAM. Among them, the aerosol fixing agent PAM-g-PHEA grafted with HEA modified polyacrylamide can more effectively capture and fix tellurium aerosol particles, and its fixed sedimentation efficiency is 94.34%, which provides a research idea for the purification of polonium radioactive aerosol by atomization fixation method

Layer-by-Layer Epitaxy of Multilayer MoS2 Wafers

Two-dimensional (2D) semiconductor of MoS2 has great potential for advanced electronics technologies beyond silicon1-9. So far, high-quality monolayer MoS2 wafers10-12 are already available and various demonstrations from individual transistors to integrated circuits have also been shown13-15. In addition to the monolayer, multilayers have narrower band gaps but improved carrier mobilities and current capacities over the monolayer5,16-18. However, achieving high-quality multilayer MoS2 wafers remains a challenge. Here we report the growth of high quality multilayer MoS2 4-inch wafers via the layer-by-layer epitaxy process. The epitaxy leads to well-defined stacking orders between adjacent epitaxial layers and offers a delicate control of layer numbers up to 6. Systematic evaluations on the atomic structures and electronic properties were carried out for achieved wafers with different layer numbers. Significant improvements on device performances were found in thicker-layer field effect transistors (FETs), as expected. For example, the average field-effect mobility ({\mu}FE) at room temperature (RT) can increase from ~80 cm2V-1s-1 for monolayer to ~110/145 cm2V-1s-1 for bilayer/trilayer devices. The highest RT {\mu}FE=234.7 cm2V-1s-1 and a record-high on-current densities of 1.704 mA{\mu}m-1 at Vds=2 V were also achieved in trilayer MoS2 FETs with a high on/off ratio exceeding 107. Our work hence moves a step closer to practical applications of 2D MoS2 in electronics.Comment: 13 pages,4 Figure

Compatibility of T91 steel with liquid Pb-Bi eutectic alloy at 450 oC

Pb-Bi eutectic alloy has been receiving increasing attention as a heavy liquid metal coolant in accelerator driven systems and Generation IV fission reactors. Compatibility of structural materials with liquid Pb-Bi eutectic alloy at high temperature is one of the issues concerned. In the present study, corrosion tests of T91 steel in stagnant Pb-Bi eutectic alloy in saturated oxygen condition at 450 篊 were carried out. After experiments, the thickness and compositional profile of the oxide layer on the specimen were analyzed using SEM and EDX. Analysis results show that the thickness of the oxide layer increases as the exposure time increases from 500 h to 1,000 h. The thickness of the oxide layer remains almost unchanged at 15 to 16 mm from 1,000 to 1,500 h. Formation of a thick and protective oxide layer at 450 oC prevents the penetration of liquid Pb-Bi eutectic alloy into the matrix of the T91 steel

miRNA-187-5p Regulates Osteoblastic Differentiation of Bone Marrow Mesenchymal Stem Cells in Mice by Targeting ICAM1

Osteoporosis (OP) is a common bone metabolic disease, the process of which is fundamentally irreversible. Therefore, the investigation into osteoblastic differentiation of bone marrow mesenchymal stem cells (BMSCs) will provide more clues for OP treatment. In the present study, we found that microRNA-187-5p (miR-187-5p) played a key role on osteoblastic differentiation, which was significantly upregulated during osteogenic differentiation of BMSCs in mice. Moreover, overexpression of miR-187-5p suppressed osteoblastic differentiation of BMSCs through increasing alkaline phosphatase (ALP), matrix mineralization, and levels of Osterix (OSX), and osteopontin (OPN) as well as runt-related transcription factor 2 (Runx2) in vitro. The results in vivo indicated that the upregulation of miR-187-5p enhanced the efficacy of new bone formation in the heterotopic bone formation assay. Luciferase reporter assay and western blot analysis revealed that miR-187-5p was involved in osteogenesis by targeting intracellular adhesion molecule 1 (ICAM-1). Furthermore, ICAM-1 silence inhibited osteoblastic differentiation of BMSCs. Taken together, our results suggested for the first time that miR-187-5p may promote osteogenesis by targeting ICAM-1, and provided a possible therapeutic target for bone metabolic diseases

Kinetic parameters of invertases from various sources.

<p>NR, not reported.</p>a<p>The data come from reference <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062306#pone.0062306-Vuji1" target="_blank">[33]</a>.</p>b<p>the unit was mmol min⁻¹.</p

Substrate profiles of uninv2.

<p>Substrates: 100 mM sucrose (a), 1-kestose (b), raffinose (c), nystose (d) and inulin (e) were hydrolyzed by uninv2. All the reactions were performed in a volume of 0.5 ml pH 4.5 HAC-NaAC buffer at 45°C for 12 h, except that sucrose was only incubated for 5 min. Peak numbers show the retention times for fructose (1), glucose (2), sucrose (3), melibiose (4), 1-kestose (5) and raffinose (6).</p

Characterization of an Invertase with pH Tolerance and Truncation of Its N-Terminal to Shift Optimum Activity toward Neutral pH

<div><p>Most invertases identified to date have optimal activity at acidic pH, and are intolerant to neutral or alkaline environments. Here, an acid invertase named uninv2 is described. Uninv2 contained 586 amino acids, with a 100 amino acids N-terminal domain, a catalytic domain and a C-terminal domain. With sucrose as the substrate, uninv2 activity was optimal at pH 4.5 and at 45°C. Removal of N-terminal domain of uninv2 has shifted the optimum pH to 6.0 while retaining its optimum temperaure at 45°C. Both uninv2 and the truncated enzyme retained highly stable at neutral pH at 37°C, and they were stable at their optimum pH at 4°C for as long as 30 days. These characteristics make them far superior to invertase from <i>Saccharomyces cerevisiae</i>, which is mostly used as industrial enzyme.</p></div

Effects of pH and temperature on the activity of recombinant uninv2 (dashed line) and M-inv2 (solid line).

<p>(a) Effect of pH on enzymatic activity, measured in 50 mM glycine-HCl buffer (pH 2.5–3.5, closed circles), HAC-NaAC buffer (pH 3.5–6.0, open circles) and Na phosphate buffer (pH 6.0–8.0, triangles) at 37°C for 30 min, the sucrose was 10 g l⁻¹ in a volume of 0.5 ml. Enzyme activity is shown as the specific activity: one unit represents 1 µmol of glucose released from the reaction per min per mg protein. (b) Effect of temperature on the activity of uninv2 (dashed line) and M-inv2 (solid line). The temperature dependence of the enzymes’ activity was measured between 20°C and 60°C under the optimum pH condition (pH 4.5 or 6.0 for uninv2 and M-inv2, respectively). The error bars represent the standard deviation of triplicate measurements.</p

Analysis of purified recombinant M-inv2.

<p>(a) SDS–PAGE analysis of M-inv2 protein stained with coomassie blue. Lane M, markers for molecular size (kDa); Lane P, protein sample. The M-inv2 is at 54 kDa by SDS-PAGE. (b) MALDI MS analysis of recombinant M-inv2, the arrows indicate the target protein peaks.</p