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Given its health benefits to the human body, quercetin (QT) offers promising applications in the healthcare food and pharmaceutical industries. However, the instability, low water solubility and low bioavailability of QT remain to be solved. In this paper, cellulose nanofiber (CNF) was used as an effective nanoscale carrier to alleviate these problems. By adjusting the solvent composition ratio and processing method, QT was optimally immobilized on CNF surfaces and was eventually encapsulated in the CNF matrices, forming a CNF/QT nanoformulation. A high loading capacity of 78.91% and encapsulation efficiency of 88.77% were achieved simultaneously. The nanoformulation exhibited better dietary performance and antioxidant activity than raw QT. Moreover, sustained release of QT was demonstrated in vitro. These results reveal that CNF is an ideal natural nanoscale dietary carrier and offers high encapsulation efficiency for healthcare supplementation. This work also provides a promising nanoformulation candidate for managing sustained antioxidant requirements.

Coronaviruses have a wide host range and can cause a variety of diseases with varying severity in different animals. Several enteric coronaviruses have been identified that are associated with diarrhea in swine and that have caused substantial economic losses. In this study, a newly emerged porcine enteric alphacoronavirus (PEAV), PEAV-GD-CH/2017, was identified from suckling piglets with diarrhea in southern China, and a full-length genome sequence of PEAV was obtained for systematic analysis. The novel PEAV sequence was most identical to that of bat-HKU2, and the differences between them were comprehensively compared, especially the uniform features of the S protein, which was shown to have a close relationship with betacoronaviruses and to perhaps represent unrecognized betacoronaviruses. In addition, Bayesian analysis was conducted to address the origin of PEAV, and the divergence time between PEAV and bat-HKU2 was estimated at 1926, which indicates that PEAV is not newly emerged and may have circulated in swine herds for several decades since the interspecies transmission of this coronavirus from bat to swine. The evolutionary rate of coronaviruses was estimated to be 1.93 × 10−4 substitutions per site per year for the RdRp gene in our analysis. For the origin of PEAV, we suspect that it is the result of the interspecies transmission of bat-HKU2 from bat to swine. Our results provide valuable information about the uniform features, origin and evolution of the novel PEAV, which will facilitate further investigations of this newly emerged pathogen., Highlights • Identify and sequence a PEAV strain from suckling piglets with diarrhea • The S protein of PEAV may recombination from unrecognized beta-CoV. • The novel PEAV was emerged approximately at 1926 based on Bayesian analysis. • PEAV origin from the interspecies transmission of bat-HKU2 from bat to swine

Natural gas hydrate can be a potential energy resource to be developed in the near future. Gas production is feasible via depressurization, which has been applied for gas extraction from gas hydrate deposits in Messoyakha. Understanding the dynamic behavior of hydrate dissociation, i.e. the variations of pressure, temperature and gas production rate during the depressurization process, is important for process optimization and predications of geological hazards caused by hydrate dissociation. In this study, methane hydrate formation and dissociation experiments were conducted using a self-designed apparatus under different conditions in simulated porous media. Hydrate formation in sand packs with different hydrate saturations were simulated, and the dynamic behavior of hydrate dissociation process and its influencing factors were analyzed, illustrated by gas production rate, accumulated gas production, and the associated temperature and pressure changes in the gas production process. The experimental results show that hydrate dissociation can be inhibited in the early stage if the production pressure is low, which can cause a decrease of the local temperature in the dissociation zone and restabilize the hydrate, and the efficiency of gas production can be improved by reducing the production pressure gradually. High permeability of the sand packs is conductive to increase gas production rate, but it can also induce a fast decrease on temperature and pressure. The time for hydrate dissociation becomes longer in the case of a higher hydrate saturation, and depressurization along with other stimulation methods, such as thermal stimulation, may be required for efficient gas production.

α-Chitin nanofibers were fabricated with dried shrimp shells via a simple high-intensity ultrasonic treatment under neutral conditions (60 KHz, 300 W, pH = 7). The diameter of the obtained chitin nanofibers could be controlled within 20–200 nm by simply adjusting the ultrasonication time. The pulsed ultrasound disassembled natural chitin into high-aspect-ratio nanofibers with a uniform width (19.4 nm after 30 min sonication). The EDS, FTIR, and XRD characterisation results verified that α-chitin crystalline structure and molecular structure were maintained after the chemical purification and ultrasonic treatments. Interestingly, ultrasonication can slightly increase the degree of crystallinity of chitin (from 60.1 to 65.8). Furthermore, highly transparent chitin films (the transmittance was 90.2% at a 600 nm) and flexible ultralight chitin foams were prepared from chitin nanofiber hydrogels.

We report a millimeter-long TiO 2 fiber with nanostructures fabricated using bamboo cellulose fiber as a template. The method includes the in situ synthesis of titanium oxide nanoparticles in the cellulose fiber template and subsequent removal of the cellulose matrix by calcination. The prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), and transmission electron microscope (TEM) techniques. XRD pattern confirmed the crystalline phase of the prepared TiO 2 is anatase phase. From the observation of SEM image, the cellulose-templated TiO 2 inherited the initial millimetric length of the bamboo cellulose. TEM image revealed the millimeter-long TiO 2 was comprised of the spherical nanoparticles with the diameter of about 30 nm. Meanwhile, the as-fabricated TiO 2 presented a superior photocatalytic ability to decompose phenol under ultraviolet irradiation. This approach is facile, and would provide ready access to metallic oxide nanostructures of desired morphology and size with the appropriate templates.

A good nanocrystal covering layer on wood can serve as a protective coating and present some new surface properties. In this study, well-aligned ZnO nanorods (NRs) arrays were successfully grown on wood surface through a two-step bottom-up growth process. The process involved pre-sow seeds and subsequently their growing into NRs under hydrothermal environment. The interface incorporation between wood and ZnO colloid particles in the precursor solution during the seeding process was analyzed and demonstrated through a schematic. The growth process of forming well-aligned ZnO NRs was analyzed by field-emission scanning electron microscopy and X-ray diffraction, which showed that the NRs elongated with increased reaction time. The effects of ZnO crystal form and capping agent on the growth process were studied through different viewpoints.

Fast-growing plant wood Populus ussuriensis Kom, and Micheliamacclurel wood were respectively modified by formation of wood-polymer composite to improve their decay resistance. Two functional monomers, glycidyl methacrylate and ethylene glycol dimethacrylate, added with a few Azo-bis-isobutryonitrile as initiator, and maleic anhydride as catalyst, were first impregnated into wood cell lumen under a vacuum-pressure condition, and then in-situ polymerized into copolymers through a catalyst-thermal treatment. The decay resistances of untreated wood and wood-polymer composites were assessed by weight loss and compared by SEM observations. SEM and FTIR analysis indicated that the in-situ polymerized copolymers fully filled up wood cell lumen and also grafted onto wood cell walls, resulting in the blockage of passages for microorganisms and moisture to wood cell walls. Thus, the decay resistance of poplar wood-polymer composite and Micheliamacclurel wood-polymer composite against brown rot fungus and white rot fungus in terms of weight loss achieved 3.43–3.92% and 1.04–1.33%, improved 95.06–95.18% and 95.10–95.35% than those of untreated poplar wood and Micheliamacclurel wood, respectively; and also respectively higher than that of boron-treated wood. The SEM observations for the decayed poplar wood, Micheliamacclurel wood and their corresponding treated wood also showed the remarkable improvement of decay resistance of wood after such treatment, which effectively protected wood from degradation by fungi.

In this work, wood materials with UV-resistant ability were successfully fabricated by depositing submicrometer-sized rutile TiO2 spheres on wood surface using a facile and one-pot hydrothermal method. The prepared samples were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and attenuated total reflectance-Fourier transformation infrared (ATR-FTIR) techniques. ATR-FTIR spectra demonstrated that chemical bonds were formed at the interfaces between rutile TiO2 and wood owing to the presence of hydroxyl groups. Accelerated aging was used to measure the UV resistance of the original wood (OW), anatase TiO2/wood (ATW) and rutile TiO2/wood (RTW). Comparison with OW and ATW samples, RTW exhibited more UV-resistant ability due to high UV light absorption capability, superior light scattering property and high recombination of the photogenerated electron and hole of the submicrometer-sized rutile TiO2 spheres on the wood surface.

To convert the hydrophilic surface of wood into a hydrophobic surface, the present study investigated activators regenerated by electron transfer for atom transfer radical polymerization (ARGET ATRP) as a method of grafting methyl methacrylate (MMA) onto the wood surface. The wood treated with 2-bromoisobutyryl bromide and with the subsequently attached MMA via ARGET ATRP under different polymerization times (2 h, 4 h, 6 h, 8 h) were examined using scanning electron microscopy, Fourier transform infrared spectroscopy, and thermogravimetric analysis. All the analyses confirmed that PMMA had been grafted onto the wood surface. Water contact angle measurement proved that the covering layer of PMMA on wood made the surface hydrophobic. Polymerization time had a positive influence on the contact angle value and higher contact angle can be produced with the prolongation of the polymerization time. When the reaction time was extended to 8 h, the contact angle of treated wood surface reached 130° in the beginning, and remained at 116° after 60 s. The ARGET ATRP method may raise an alteration on the wood surface modification.

Ultralong and highly uniform cellulose I nanofibers (CNFs) with lengths >1 mm, diameters of 30–80 nm, and aspect ratios >10,000 were successfully prepared from bamboo fibers, by using chemical pretreatment combined with high intensity ultrasonication to purify and defibrillate bamboo fibers into parallel arrays cellulose nanofibrils (1–5 nm width and several microns long), and then assembling the nanofibrils into ultralong CNFs by simple freeze-drying; Similar findings were also observed from the micrographs of CNFs fabricated from wheat straw and softwood fibers. The chemical composition of the fabricated CNFs is mainly cellulose because hemicelluloses and lignin were appreciably removed during the chemical process. With the removal of the matrix materials, the cellulose I crystal structure was maintained, whereas the crystallinity and thermal stability of the fibers increased. The crystallinity and thermal degradation temperature of the CNFs reached 61.25% and over 309 °C, respectively. Ultralong CNFs could serve as unique building blocks for green nanocomposites and are expected to open up new opportunities for application in tissue engineering scaffolds.

Cellulose nanofibers were individualized from poplar wood in two distinct stages. Initially, wood fibers were subjected to a chemical process to eliminate lignin and hemicellulose. The obtained chemical-purified cellulose fibers were then mechanically separated into nanofibers using high-intensity ultrasonication. The diameter distributions of the resulting nanofibers were dependent on the output power of the ultrasonic treatment. TEM and FE-SEM images showed that the diameter of the obtained nanofibers ranged from 5 to 20nm when the output power of the conducted ultrasonication was greater than 1000W. FTIR and XRD results indicated that hemicellulose and lignin were removed extensively in the cellulose nanofibers, with a crystallinity of approximately 69%. The TGA results showed that the degradation temperature of the nanofibers was dramatically increased to approximately 335°C compared with 210°C of the original wood fibers. The obtained nanofibers may be potentially applied in various fields, such as bio-nanocomposites, tissue engineering scaffolds, filtration media, packaging, and so on.

This paper examines the growth of anatase TiO 2 coating on a wood surface through the hydrolysis of tetrabutyl orthotitanate (TBOT) in different conditions, using a controlled hydrothermal method at low temperatures. Energy disperse X-ray analysis and Fourier transform infrared spectroscopy analysis confirm that the growth of TiO 2 coating on a wood surface is bonded to hydrocarbon chains. Several reaction factors that influence the morphologies and amount of TiO 2 present on wood surface were also investigated. As observed from the scanning electron microscopy images, the morphology and content of TiO 2 grown on a wood surface could be controlled under appropriate reaction conditions. Approximately 32.6% TiO 2 content on a wood surface could be obtained when specific conditions are applied.

Characterization of natural gas hydrate bearing formations is important in the exploration and development of gas hydrate resources in subsea sediments. Solid hydrates can fill the voids of the matrix formed by sand grains and change their cementation condition, which may have a great impact on the electrical resistance and sound velocity of the sand matrix. In this study, experiments have been conducted to measure the ultrasonic velocity and electrical resistance in a large sandpack simulating the conditions of hydrate formation in subsea sediments. The effects of hydrate on the resistivity and ultrasonic velocity of hydrate bearing sand matrix have been revealed and modeled. The data can be used in well logging to determine hydrate saturation and other properties of hydrate bearing formations.