Mackaywrenn9868

Herein, a two-step hydrothermal pretreatment combined with alkali extraction method was applied to deconstruct the poplar cell walls for enzymatic hydrolysis. #link# Results revealed that 88.1 % of hemicelluloses and 77.6 % of lignin were removed during the integrated treatment performed at 180 °C and a maximum enzymatic hydrolysis efficiency of 96.1 % was achieved. Confocal Raman microscopy suggested that the removal of hemicelluloses from cell walls was inhomogeneous, and most hemicelluloses were released from the secondary wall. In addition, 35.2-56.8 % of hemicelluloses were isolated from the integrated treatment. Detailed structural analysis revealed that the water-soluble hemicelluloses possessed more branched structure than the alkali-soluble hemicelluloses and the hemicelluloses isolated from the poplar were mainly composed of a linear backbone of (1→4)-β-d-Xylp with 4-O-Me-α-d-GlcpA attached as side chains. This work provides an efficient pathway to transform poplar into fermentable sugars and hemicelluloses with considerable yield.Exfoliated kaolinite sheets/cellulose fibres nanocomposite (EXK/CF) was synthesised as a novel hybrid of materials of enhanced surface area and adsorption capacities for inorganic-selenate [Se(VI)] and selenite [Se(IV)]-and organic selenium pollutants-selenomethionine (SeMt). The adsorption reactions of the addressed selenium forms followed pseudo-first-order as a kinetic model and Langmuir as an isotherm model. The fitting results and the calculated Gaussian energies-Se (VI) at 2.0 KJ/mol, Se (IV) at 2.2 KJ/mol, and SeMt at 1.7 KJ/mol-suggested physisorption uptake in a monolayer and homogeneous form. The theoretical maximum selenium uptake capacity (qmax) for Se (VI), Se (IV), and SeMt was 137.5 mg/g, 161.4 mg/g, and 95.4 mg/g, respectively. The thermodynamic investigation verified spontaneous and exothermic properties of the selenium uptake reactions by the EXK/CF composite.In order to overcome treatment difficulty of S. aureus infections, a pH/hyaluronidase dual responsive enrofloxacin-cyclodextrin (β-CD) inclusion complexes (IC) containing hyaluronic acid/chitosan (HA/CS) self-assemble composite nanosystems covered by poloxamer 188 (F68) was firstly explored for targeted "on-demand" delivery. The FTIR, DSC and PXRD showed that enrofloxacin was embedded into IC and then distributed into F68 coating nanogels formulated by electrostatic interaction between CS and HA. The optimal nanosystems of 118.8 ± 30.7 nm showed excellent stability and responsive release in the acid medium, hyaluronidase containing medium, and LB broth medium where S. aureus present. The nanosystems displayed strong surface adsorption on S. aureus and enhanced activity against S. aureus. It had stronger sustained release than the polymeric nanoparticles formulated by entrapping of IC into F68 and the single HA/CS nanogels. This study provides a promising multi-functionalized nanosystems to overcome the treatment challenge of S. aureus and other bacterial infections.Dynamics and thermophysical properties of amorphous starch were explored using molecular dynamics (MD) simulations. Using the OPLS3e force field, simulations of short amylose chains in water were performed to determine force field accuracy. Using well-tempered metadynamics, a free energy map of the two glycosidic angles of an amylose molecule was constructed and compared with other modern force fields. Good agreement of torsional sampling for both solvated and amorphous amylose starch models was observed. link2 Using combined grand canonical Monte Carlo (GCMC)/MD simulations, a moisture sorption isotherm curve is predicted along with temperature dependence. Concentration-dependent activation energies for water transport agree quantitatively with previous experiments. Finally, the plasticization effect of moisture content on amorphous starch was investigated. Predicted glass transition temperature (Tg) depression as a function of moisture content is in line with experimental trends. Further, our calculations provide a value for the dry Tg for amorphous starch, a value which no experimental value is available.Herein, an amidoxime-functionalized chitosan (CTS) AM/AO/AEBI-CTS containing imidazoline groups was facilely prepared through amidoximation of cyano groups in cross-linked CTS obtained by crosslinking of imidazoline-functionalized polyacrylamide and CTS. AM/AO/AEBI-CTS exhibited porous structure, good water wettability, and higher selectivity for Cu2+ than Ni2+. The adsorption process correlated well with Sips isotherm and pseudo-second-order kinetics models. The adsorption capacities for Cu2+ and Ni2+ onto AM/AO/AEBI-CTS were 190.7 and 128.9 mg/g, respectively. The adsorption thermodynamics demonstrated that the adsorption of Cu2+ and Ni2+ ions onto AM/AO/AEBI-CTS was a spontaneous endothermic process. The FTIR and XPS analyses revealed that nitrogen and oxygen atoms were involved in the chelation with metal ions. The presence of Na+, K+ and Ca2+ had weakly impact on the adsorption efficiency of AM/AO/AEBI-CTS. Furthermore, the adsorption efficiency of AM/AO/AEBI-CTS remained above 90 % after five adsorption-desorption successive cycles. Overall, this CTS material has a good application prospects for wastewater treatment.Cellulose nanomaterials (CNMs) have attracted great attention in the last decades due to the abundance of the biopolymer, the biorenewable character and the outstanding mechanical properties they account for. These, together with their biocompatibility makes them ideal candidates for tissue engineering (TE) applications. Additive manufacturing is an ideal biofabrication approach for TE, providing rapid and reliable technologies to produce scaffolds aimed for the guidance of host or implanted cells to form functional tissues. However, the control of parameters at the nanoscale that regulate cellular functions such as proliferation and differentiation remain challenging. This review article presents the latest advances in the use of CNMs as platforms to guide cellular functions in additive manufactured scaffolds. Special attention is given to functionalization routes, methods to exploit them as topographical cues and to improve the local mechanical properties together with the resulting cell-CNM interactions.Magnetic NiFe2O4 nanoparticles and multi-walled carbon nanotubes functionalized cellulose composite (m-NiFe2O4/MWCNTs@cellulose) as a magnetic bioadsorbent was prepared and used for effectively removing Congo Red (CR) from aqueous solution. The chemical and physical properties of the prepared m-NiFe2O4/MWCNTs@cellulose were characterized by XRD, TGA, FT-IR, VSM, SEM and TEM. Batch experiments were carried out to investigate the adsorption capacity and mechanisms. Effects of different adsorption parameters such as initial CR concentration, adsorbent dosage and temperature were studied. Results demonstrated that m-NiFe2O4/MWCNTs@cellulose had high adsorption capacity for CR from aqueous solution. The obtained experimental data fitted well with the pseudo-second-order equation and followed the Langmuir isotherm model with a maximum adsorption capacity of 95.70 mg g-1 for CR. The m-NiFe2O4/MWCNTs@cellulose with rapid magnetic separation and high adsorption capacity can be a promising and recyclable engineering biomaterials for purification and treatment of practical wastewater.Chitosan is considered as a green additive with broad application prospects due to its advantages like biodegradability and antibacterial ability. Herein, we proposed an effective chitosan grafting approach via "one-enzyme double catalysis" strategy which aimed at functionalizing wool fibers to achieve bidirectionally multiple covalent crosslinking between chitosan and wool by laccase/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) mediated oxidization. The mechanism was studied using models of wool and chitosan in terms of UV, FTIR, GPC and MALDI-TOF MS. Meanwhile, the structure and morphology of wool fiber grafted with chitosan were characterized by ATR-FTIR and SEM. Compared with Selleck UNC2250 , this efficient method can significantly improve the dimensional stability to felting (2.53 %), wettability and dyeability of wool fabric, and can also compensate for the strength loss caused by the pretreatment. link3 The present work provides a useful path for the enzymatic modification of keratin-containing fibers like wool using chitosan and other natural biopolymers with similar structure.A new natural formulation composed of CMC and various contents of CNC immobilized AgNPs (CNC@AgNPs) was developed for paper coating. The mechanical strength, water vapor and air barrier properties, and antibacterial activities of CMC/CNC@AgNPs coated paper improved with the increasing content of CNC@AgNPs. CMC/CNC@AgNPs7 % coated paper exhibited 1.26 times increase in tensile strength, 45.4 % decrease in WVP, 93.3 % reduction in air permeability as well as the best antibacterial activities against E.coli and S.aureus compared with uncoated paper. Moreover, the cumulative release rate of AgNPs from coated paper significantly reduced due to the immobilization effect of CNC on AgNPs. Furthermore, CMC/CNC@AgNPs coated paper was used to package strawberries under ambient conditions. The results showed that coated paper could maintain better strawberries quality compared with unpackaged strawberries and extend the shelf-life of strawberries to 7 days. Therefore, the prepared CMC/CNC@AgNPs coated paper will have a great application prospect in the food packaging.Inulin-type fructans (ITFs) as functional fructans and soluble dietary fiber are a mixture of inulin, oligofructose and fructooligosaccharide with β configuration. They are modified by gut microbiota at the end of ileum, subsequently, improve digestive system, metabolic syndrome, immune system and inflammatory diseases, and prevent against infection and cancer. However, it has been reported that inadequate consumption of ITFs aggravates the development of non-alcoholic fatty liver disease, results in gastrointestinal symptoms, liver cancer and intestinal inflammation. Therefore, this review summarizes the health benefits, pharmaceutical applications and safety evaluation of ITFs, which would direct their rational applications.Self-assembly potential of new amphiphilic block copolymers containing dextran (Mn 4500, 8000, 15,000) and a semi-rigid deoxycholic acid-oligoethyleneglycol polyester (Mn 2500-8800, 2 or 4 ethyleneglycol units), was evaluated as a function of copolymer composition and self-assembly procedure, using dynamic light scattering and transmission electron microscopy. Addition of copolymer solution to water provided small star-like micelles (∼ 100 nm), while addition of water to copolymer solution led to various morphologies and sizes (60-600 nm), depending on polymer composition. Worm-like micelles were obtained from a copolymer containing dextran with Mn 4500 and 66 wt% polyester, and vesicles were formed by copolymers prepared from dextran with Mn 8000 and containing 46 wt% polyester. Presence of a longer oligoethyleneglycol decreased the size of micelles and vesicles due to an enhanced flexibility of the polyester hydrophobic block. The results allow the selection of the most appropriate parameters to obtain the desired aggregate characteristics.