Ni/HZSM-5 catalyst preparation by deposition-precipitation. Part 2. Catalytic hydrodeoxygenation reactions of lignin model compounds in organic and aqueous systems

Nickel metal supported on HZSM-5 (zeolite) is a promising catalyst for lignin depolymerization. In this work, the ability of catalysts prepared via deposition-precipitation (DP) to perform hydrodeoxygenation (HDO) on two lignin model compounds in organic and aqueous solvents was evaluated; guaiacol in dodecane and 2-phenoxy-1-phenylethanol (PPE) in aqueous solutions. All Ni/HZSM-5 catalysts were capable of guaiacol HDO into cyclohexane at 523 K. The role of the HZSM-5 acid sites was confirmed by comparison with Ni/SiO2 (inert support) which exhibited incomplete deoxygenation of guaiacol due to the inability to perform the cyclohexanol dehydration step. The catalyst prepared with 15 wt% Ni, a DP time of 16 h, and a calcination temperature of 673 K (Ni(15)/HZSM-5 DP16_Cal673), performed the guaiacol conversion with the greatest selectivity towards HDO products, with an intrinsic rate ratio (HDO rate to conversion rate) of 0.31, and 90% selectivity to cyclohexane. Catalytic activity and selectivity of Ni/HZSM-5 (15 wt%) in aqueous environments (water and 0.1 M NaOH solution) was confirmed using PPE reactions at 523 K. After 30 min reaction time in water, Ni/HZSM-5 exhibited ~100% conversion of PPE, and good yield of the desired products; ethylbenzene and phenol (~35% and 23% of initial carbon, respectively). Ni/HZSM-5 in NaOH solution resulted in significantly higher ring saturation compared to the Ni/HZSM-5 in water or the NaOH solution control

TEM Examination of Surface Characteristics of Rubberwood (Hevea brasiliensis) HTMP Fibers

A study was conducted on the surface features of rubberwood high temperature thermomechanical (HTMP) fibers. The transmission electron microscopy (TEM) was used for the characterization of the surface features. The fracture behavior of the cell walls of the fibers were also studied. It was found that the outer surface of the HTMP fiber wall was completely covered by middle lamella, whose thickness was highly variable

Presence of a Distinct S3 Layer in Mild Compression Wood Tracheids of Pinus radiata

A study of electron microscopic evidence for the presence of a distinct S3 layer in mild compression wood tracheids of Pinus radiata was performed. S3 layers have an important role to play in strengthening the xylem tissues in standing trees and in minimizing collapse in wood tissues. These layers are also likely to be an important factor in wood processes involving physical and chemical treatments, as well as in the biodegradation of wood

Anisotropy of the Upper Critical Field and Critical Current in Single Crystal MgB2_2

We report on specific heat, high magnetic field transport and $ac-$susceptibility measurements on magnesium diboride single crystals. The upper critical field $H_{c2}$ for magnetic fields perpendicular and parallel to the Mg and B planes is presented for the first time in the entire temperature range. A very different temperature dependence has been observed in the two directions which yields to a temperature dependent anisotropy with $\Gamma \sim$ 5 at low temperatures and about 2 near $T_c$. A peak effect is observed in susceptibility measurements for $H \sim$2 T parallel to the $c-$axis and the critical current density presnts a sharp maximum for $H$ parallel to the ab-plane.Comment: 6 pages, 5 figure

Naïve CD8 + T cell derived tumor-specific cytotoxic effectors as a potential remedy for overcoming TGF-β immunosuppression in the tumor microenvironment

Despite of the potential implications for cancer immunotherapy, conventional approaches using in vitro expanded CD8 + T cells have suboptimal outcomes, mostly due to loss of functionality from cellular exhaustion. We therefore investigated the phenotypic and functional differences among in vitro activated CD8 + T cells of three different sources, namely naïve (NT eff), memory (MT eff) and tumor-infiltrating lymphocytes (TIL eff) from human and mice, to better understand mechanisms behind potent effector functions and potential for overcoming current limitations. In line with the greater proliferation activity and longer telomere lengths of NT eff populations, cells of naïve origin exhibited significantly less amounts of T cell exhaustion markers than those of MT eff and TIL eff, and moreover, acquired distinct expression patterns of memory-promoting transcription factors, T-bet and Eomes, induced in a rapid and sustainable manner. NT eff cells appeared to have lower expression of Foxp1 and were refractory to apoptosis upon TGF-β conditioning, implying better survival potential and resistance to tumor-induced immune suppression. Of CD8 + T cell pools activated to tumor-specific CTLs, naïve cell generated effectors possessed the most potent cytotoxic activity, validating implications for use in rational design of adoptive immunotherapy11091sciescopu

Competing Orders in Coupled Luttinger Liquids

We consider the problem of two coupled Luttinger liquids both at half filling and at low doping levels, to investigate the problem of competing orders in quasi-one-dimensional strongly correlated systems. We use bosonization and renormalization group equations to investigate the phase diagrams, to determine the allowed phases and to establish approximate boundaries among them. Because of the chiral translation and reflection symmetry in the charge mode away from half filling, orders of charge density wave (CDW) and spin-Peierls (SP) diagonal current (DC) and $d$-density wave (DDW) form two doublets and thus can be at most quasi-long range ordered. At half-filling, umklapp terms break this symmetry down to a discrete group and thus Ising-type ordered phases appear as a result of spontaneous breaking of the residual symmetries. Quantum disordered Haldane phases are also found, with finite amplitudes of pairing orders and triplet counterparts of CDW, SP, DC and DDW. Relations with recent numerical results and implications to similar problems in two dimensions are discussed.Comment: 16 pages, 5 figures, 4 tables. Revised manuscript; a misprint in Eq. B3 has been corrected. The paper is already in print in PR

Bio-orthogonal Supramolecular Latching inside Live Animals and Its Application for in Vivo Cancer Imaging

© 2019 American Chemical Society.Here, we demonstrate a supramolecular latching tool for bio-orthogonal noncovalent anchoring of small synthetic molecules in live animal models using a fully synthetic high-affinity binding pair between cucurbit[7]uril (CB[7]) and adamantylammonium (AdA). This supramolecular latching system is small (∼1 kDa), ensuring efficient uptake into cells, tissues, and whole organisms. It is also chemically robust and resistant to enzymatic degradation and analogous to well-characterized biological systems in terms of noncovalent binding. Occurrence of fluorescence resonance energy transfer (FRET) between cyanine 3-CB[7] (Cy3-CB[7]) and boron-dipyrromethene 630/650X-AdA (BDP630/650-AdA) inside a live worm (Caenorhabditis elegans) indicates efficient in situ high-affinity association between AdA and CB[7] inside live animals. In addition, selective visualization of a cancer site of a live mouse upon supramolecular latching of cyanine 5-AdA (Cy5-AdA) on prelocalized CB[7]-conjugating antibody on the cancer site demonstrates the potential of this synthetic system for in vivo cancer imaging. These findings provide a fresh insight into the development of new chemical biology tools and medical therapeutic systems11sciescopu