Fabrication of the continuous carbon fiber reinforced plastic composites by additive manufacturing

Additive manufacturing has been adopted in a wide range of industry. However, limited mechanical properties have prevented additive manufacturing from further development in high value applications. Carbon-fibre-reinforced composites are widely used in automobile and aerospace industries due to their improved mechanical properties and reduced weight. The introduction of carbon fibre into additive manufacturing will allow its application across a broader industrial field. In this paper, carbon-fibre-reinforced composite samples were produced by material extrusion and stereolithography. Tensile tests were performed on pure polymer and carbon-fibre-reinforced samples. Experimental results were compared to theoretical ones based on a rule of mixture. Samples produced by material extrusion showed a 73.3 % reduction in elastic modulus compared with theoretical values whereas those produced by stereolithography showed a 42.06% reduction. Micrographs showed that stereolithography samples had better bonding between the matrix and the fibre

Photosynthesis-fermentation hybrid system to produce lipid feedstock for algal biofuel

<div><p>To avoid bacterial contamination due to medium replacement in the expanded application of a photosynthesis–fermentation model, an integrated photosynthesis-fermentation hybrid system was set up and evaluated for algal lipid production using <i>Chlorella protothecoides</i>. In this system, the CO₂-rich off-gas from the fermentation process was recycled to agitate medium in the photobioreactor, which could provide initial cells for the heterotrophic fermentation. The cell concentration reached 1.03±0.07 g/L during photoautotrophic growth and then the concentrated green cells were switched to heterotrophic fermentation after removing over 99.5% of nitrogen in the medium by a nitrogen removal device. At the end of fermentation in the system, the cell concentration could reach as high as 100.51±2.03 g/L, and 60.05±1.38% lipid content was achieved simultaneously. The lipid yield (60.36±2.63 g/L) in the hybrid system was over 700 times higher than that in a photobioreactor and exceeded that by fermentation alone (47.56±7.31 g/L). The developed photosynthesis-fermentation hybrid system in this study was not only a feasible option to enhance microalgal lipid production, but also an environment-friendly approach to produce biofuel feedstock through concurrent utilization of ammonia nitrogen, CO₂, and organic carbons.</p> </div

Map of FGF2-amp2 and the CpG sites in this amplicon.

<p>The CpG island in proximity of initiation codon (ATG) is indicated as capital letters. Amplicon FGF2-amp2 was underlined with solid line. Individual CpG sites in FGF2-amp2 are indicated as bold type and numbered from CpG-S1 to CpG-S9. Pax3 binding site was underlined with hollow line. The initiation codon (ATG) is also underlined. N and n represent the unknown sequence.</p

Expression and Methylation of <i>FGF2</i>, <i>TGF-β</i> and Their Downstream Mediators during Different Developmental Stages of Leg Muscles in Chicken

<div><p>A number of growth factors determine the proliferation of myoblasts and therefore the number of ultimate myofibers. The members of transforming growth factor-beta (TGF-β) family and the fibroblast growth factor 2 (FGF2) have profound effects on skeletal myoblasts proliferation in various animal systems. To investigate their involvement in different stages of avian skeletal muscle development <i>in vivo</i>, we detected the mRNA expression and DNA methylation profiles of <i>TGF-β2</i>, <i>TGF-β3, FGF2</i> and their downstream mediators in leg muscles at embryonic day 10, day of hatch and day 45 posthatch, using both Arbor Acres meat-type and White Leghorn egg-type chickens. By real-time PCR, we found that the expression levels of <i>TGF-β2</i>, <i>TGF-β3</i>, <i>Smad3</i> and <i>FGF2</i> were significantly (<i>P</i>≤0.01) higher at embryonic day 10, a developmental window of abundant fetal myoblasts expansion, by comparison to day of hatch and day 45 posthatch. The methylation status of the 5′ end region of these four genes was examined subsequently. A section of a CpG island in the 5′ end region of <i>FGF2</i> was significantly hypomethylated (<i>P</i>≤0.01) at embryonic day 10, compared with neonatal and postnatal stages in both stocks. Our results suggested that <i>TGF-β2</i>, <i>TGF-β3</i>, <i>Smad3</i> and <i>FGF2</i> may play important roles in fetal myoblasts proliferation in chicken hindlimb, and the transcription of <i>FGF2</i> in this wave of myogenesis could be affected by DNA methylation in 5′ flanking region. These outcomes contribute to our knowledge of the growth factors in avian myogenesis. Further investigation is needed to confirm and fully understand their functions in fetal limb myogenesis in birds.</p></div

Expressions of candidate genes in leg muscles of AA broiler and White Leghorn chicken.

<p>Panels A, B, C, D and E show <i>TGF-β2</i>, <i>TGF-β3</i>, <i>Smad3</i>, <i>FGF2</i> and <i>PKCα</i> mRNA expressions in lower leg muscles, respectively. Groups are as follows: AA broiler and White Leghorn chicken, sampled at embryonic day 10, day of hatch and day 45 posthatch. Target gene expression is presented relative to <i>GAPDH</i> expression and normalized to a calibrator. Error bars represent standard deviation of the means. *<i>P</i>≤0.05, **<i>P</i>≤0.01.</p

DNA methylation of candidate genes in leg muscles of AA broiler and White Leghorn chicken.

<p>Panels A and B show DNA methylation of TGF-β2-amp, TGF-β3-amp1 and FGF2-amp2 in lower leg muscles of AA broiler and White Leghorn chicken, respectively. (%) methylation: the number of methylated CpG sites/(the number of methylated CpG sites + the number of unmethylated CpG sites). Error bars represent standard error of the means. *<i>P</i>≤0.05, **<i>P</i>≤0.01.</p

Primers used in the real-time PCR analysis.

<p>Primers used in the real-time PCR analysis.</p

Primers used in the DNA methylation analysis.

1<p>Bold symbol represents the amplicons with good quality.</p>2<p>No. of CpG site = the number of CpG sites in each amplicon.</p

Primary and Higher Order Structure of the Reaction Center from the Purple Phototrophic Bacterium Blastochloris viridis: A Test for Native Mass Spectrometry

The reaction center (RC) from the phototrophic bacterium Blastochloris viridis was the first integral membrane protein complex to have its structure determined by X-ray crystallography and has been studied extensively since then. It is composed of four protein subunits, H, M, L, and C, as well as cofactors, including bacteriopheophytin (BPh), bacteriochlorophyll (BCh), menaquinone, ubiquinone, heme, carotenoid, and Fe. In this study, we utilized mass spectrometry-based proteomics to study this protein complex via bottom-up sequencing, intact protein mass analysis, and native MS ligand-binding analysis. Its primary structure shows a series of mutations, including an unusual alteration and extension on the C-terminus of the M-subunit. In terms of quaternary structure, proteins such as this containing many cofactors serve to test the ability to introduce native-state protein assemblies into the gas phase because the cofactors will not be retained if the quaternary structure is seriously perturbed. Furthermore, this specific RC, under native MS, exhibits a strong ability not only to bind the special pair but also to preserve the two peripheral BCh’s

Oxidative Corrosion Mechanism for Ag@C Coaxial Nanocables in Radiolytic Water

To date it remains challenging to clarify the corrosion mechanism of coaxial nanocables in an oxidative moisture environment, which sets an immediate bottleneck for their engineering application. Herein, we report a series of <i>in situ</i> structure evolutions of Ag and Ag@C coaxial nanocables in a liquid environmental transmission electron microscope, followed with mechanistic unraveling of their oxidative corrosion. The bubbles generated by Ag nanocable oxidation inversely triggered rapid dissolution of the nanocables in radiolytic water. For the complicated dissolution of Ag@C nanocables, the oxidative species interact with carbon defects to thicken the carbon shell; as a consequence of holes drilling-on and exposure to the oxidative water, the inner Ag nanocables were triggered for its dissolution. The derived oxidation mechanism of nanocables provides us new insight into accurately controlling antioxidative chemistry