Understanding the Adhesion Mechanism in Mycelium-Assisted Wood Bonding

The increasing environmental awareness has led to an increased interest in developing more sustainable materials as alternatives to petroleum-derived products. Among different nature-based products, fungal-mycelium-based bio-composites have gained considerable attention in various applications. Multiple materials with different densities and structures and potential applications can be fabricated by inoculating filamentous white-rot fungi in lignocellulosic materials and other substrates. Different from lower-density as-grown foam-like mycelium composites, higher-density mycelium-lignocellulosic panels have the potential to replace commercial particleboard and fiberboard bonded by petroleum-based resins. This kind of composite can be produced by directly adding heat and pressure to the low-density foams or by assembling mycelium-industry wastes before hot-pressing. The main goal of this dissertation was to investigate the principal adhesion mechanisms involved in the production of hot-pressed mycelium bio-composites. The functionality of surface mycelium for wood bonding was thoroughly investigated by growing Trametes versicolor on yellow birch veneers. The presence of surface mycelium improved the interface between two wood layers and consequently enhanced bonding. The surface mycelium layer was also confirmed to be able to be utilized as a stand-alone adhesive to bond untreated wood. The exopolysaccharides and proteins located at the interface between aerial mycelium and the substrate were confirmed to play an essential role in adhesion. The bonding mechanism and functionality of mycelium were also investigated in both as-grown and hot-pressed bio-composite structures. For low-density as-grown foam structures, fungal mycelium only worked as a binder, the lignocellulosic substrate material played an essential role in sound absorption and thermal insulation properties, and the denser mycelium structure had a negative effect on these properties. In a higher-density hot-pressed panel system, fungal mycelium contributed to bonding and reinforced the bio-composite by filling the gaps. Additionally, we also demonstrated that combining the advantages of nanocellulose research at UMaine into our novel mycelium bio-composite can provide further improvements in properties to manufacture formaldehyde-free hybrid composite panels. Finally, we discovered an all-natural mycelium surface with tunable wettability that can be switched several times from hydrophobic to hydrophilic status by a simple treatment. These surfaces can have potential applications in medical microfluidics and invisible pattern printing

International standards for exporting firms: Evidence from China

The existing literature provides mixed evidence of the impact of ISO 9000 international standards on country level export growth. Since it is costly to adopt the international standards, it is important to understand how these standards increase exports at the firm level. This paper examines the effect of ISO 9000 standards on firm-level export growth in China, which of all countries has the highest number of firms adopting ISO 9000 standards. With the assortative matching methodology, we first examine the factors related to the choice of applying for the certification. After controlling for this endogeneity issue, our results show that obtaining ISO 9000 standards significantly increases firm exports. Furthermore, we find low-tech firms and non-state-owned enterprises are more likely to benefit from adopting the standards. Overall, our study provides important guidelines for firms applying for the international quality standards

Induction of MET Receptor Tyrosine Kinase Down-Regulation through Antibody-Mediated Receptor Clustering

The proto-oncoprotein MET is a receptor tyrosine kinase that plays a key role in cancer cell growth and invasion. We have used fluorescence-tagged antibodies to activate MET in live serum-starved glioblastoma cells and monitor the fate of antibody-bound MET receptor in single cell-based assays. We found that the antibodies induced rapid and transient formation of highly polarized MET clusters on the plasma membrane and promoted the activation of MET, resembling the initial effects of binding to its ligand, HGF. However, the antibody-induced clustering and activation of MET led to the rapid removal of the receptor from cell surface and altered its intracellular processing, resulted in rapid degradation of the receptor. Consequently, while cells pre-treated with HGF remain competent to respond to further HGF stimulation, cells pre-treated with antibodies are refractory to further HGF stimulation due to antibody-mediated MET depletion. Removal of MET by sustained treatment of antibodies blocked cancer cell migration and invasion. Our studies reveal a novel mechanism to alter the recycling process of MET in glioblastoma cancer cells by promoting the receptor degradation through a proteasome-sensitive and lysosome-dependent pathway through the ligand-independent activation of MET using anti-MET antibodies

International Standards For Exporting Firms: Evidence From China

The existing literature provides mixed evidence of the impact of ISO 9000 international standards on country level export growth.  Since it is costly to adopt the international standards, it is important to understand how these standards increase exports at the firm level.  This paper examines the effect of ISO 9000 standards on firm-level export growth in China, which of all countries has the highest number of firms adopting ISO 9000 standards.  With the assortative matching methodology, we first examine the factors related to the choice of applying for the certification. After controlling for this endogeneity issue, our results show that obtaining ISO 9000 standards significantly increases firm exports.  Furthermore, we find low-tech firms and non-state-owned enterprises are more likely to benefit from adopting the standards.  Overall, our study provides important guidelines for firms applying for the international quality standards

Normalized solutions for a fractional Choquard-type equation with exponential critical growth in R\mathbb{R}

In this paper, we study the following fractional Choquard-type equation with prescribed mass \begin{align*} \begin{cases} (-\Delta)^{1/2}u=\lambda u +(I_\mu*F(u))f(u),\ \ \mbox{in}\ \mathbb{R}, \displaystyle\int_{\mathbb{R}}|u|^2 \mathrm{d}x=a^2, \end{cases} \end{align*} where $(-\Delta)^{1/2}$ denotes the $1/2$-Laplacian operator, $a>0$, $\lambda\in \mathbb{R}$, $I_\mu(x)=\frac{{1}}{{|x|^\mu}}$ with $\mu\in(0,1)$, $F(u)$ is the primitive function of $f(u)$, and $f$ is a continuous function with exponential critical growth in the sense of the Trudinger-Moser inequality. By using a minimax principle based on the homotopy stable family, we obtain that there is at least one normalized ground state solution to the above equation.Comment: arXiv admin note: text overlap with arXiv:2211.1370

Hydro-mechanical behaviours of highly compacted sand-bentonite mixture

AbstractThis paper presents the results of laboratory testing on a heavily compacted sand-bentonite mixture. To measure the soil-water retention curve (SWRC) of the mixture over a large range of suction, a pressure plate apparatus and filter papers were used. The obtained SWRC shows that the measurements via the two methods consistently agree with each other. By using a suction-controlled oedometer for unsaturated soils, a series of one-dimensional compression tests were performed on the unsaturated compacted sand-bentonite mixture at different constant suctions. The testing results indicate that the yield stress increases and compression index decreases with the increase of imposed suction. The results also demonstrate that the mixture wetted to saturation and subsequently dried to a certain suction level has a lower yield stress than that wetted directly to the same suction

Analysis of dynamic stiffness effect of primary suspension helical springs on railway vehicle vibration

Helical springs within the primary suspension are critical components for isolating the whole vehicle system from vibration generated at the wheel/rail contact. As train speeds increase, the frequency region of excitation becomes larger, and a simplified static stiffness can no longer represent the real stiffness property in a vehicle dynamic model. Coil springs in particular exhibit strong internal resonances, which lead to high vibration amplitudes within the spring itself as well as degradation of the vibration isolation. In this paper, the dynamic stiffness matrix method is used to determine the dynamic stiffness of a helical spring from a vehicle primary suspension. Results are confirmed with a finite element analysis. Then the spring dynamic stiffness is included within a vehicle-track coupled dynamic model of a high speed train and the effect of the dynamic stiffening of the spring on the vehicle vibration is investigated. It is shown that, for frequencies above about 50 Hz, the dynamic stiffness of the helical spring changes sharply. Due to this effect, the vibration transmissibility increases considerably which results in poor vibration isolation of the primary suspension. Introducing a rubber layer in series with the coil spring can attenuate this effect

Acid Sphingomyelinase Regulates the Localization and Trafficking of Palmitoylated Proteins

In human, loss of Acid Sphingomeylinase (ASM/SMPD1) causes Niemann-Pick Disease, type A. ASM hydrolyzes sphingomyelins to produce ceramides but protein targets of ASM remain largely unclear. ... See full text for complete abstract

Influences of Suspended Equipment under Car Body on High-speed Train Ride Quality

AbstractA vertical dynamics model of rigid-flexible coupling railway vehicle including suspended device under chassis is built. Using this model, the influences of devices suspending methods on ride quality of high-speed train are analyzed with the covariance method. Results show that the reasonable parameters of the equipments, which are used to suspend devices under car body, can effectively suppress the vibration of the flexible car body. And the suspending equipment stiffness dominates in the anti-vibration effects. Devices with elastic suspending would better be close to the centre of car body and the bigger the device mass is, the better the ride quality of the car body centre will be achieved. The optimal static deflection point of elastic suspending equipment will change and fluctuate with the change of the vehicle running speed. With the static deflection of about 6mm, the high-speed train in this paper will achieve better ride quality and the vibration of suspended device will be acceptable