查看更多>>摘要：Cotton (Gossypium hirsutum) is the most important fiber crop globally and there is an incentive to improve cotton fiber yield and quality to meet the growing market demand. 1-Aminocyclopropane-1-Carboxylic Acid Oxidase (ACO) has been identified as a rate-limiting enzyme in the biosynthesis of ethylene that is known to play a pivotal regulatory role in fiber development. According to transcriptomic data analysis, GhACO1 is preferentially expressed at fiber elongation stage in a number of G. hirsutum varieties, suggestive of its involvement in regulating fiber development. Ethylene is known to cause premature senescence, and to abrogate its potential negative effects on plant growth by constitutive overexpression of GhACO1, a fiber-specific promoter E6 that imparts strong transcriptional activity in fiber elongation stage was employed to drive GhACO1 expression to improve fiber quality. The E6::GhACO1 cotton transgenic lines showed substantial improvements in fiber length, fiber strength and fiber yield relative to wild type. Exogenous application of pyrazinecarboxylic acid that is an effective inhibitor of ACO enzyme inhibited fiber elongation in ovule culture, validating that GhACOs may improve fiber quality by increasing ethylene levels. Furthermore, RNA-Seq analysis showed that upregulation of GhACO1 can activate the transcription of genes that are involved in hydrogen peroxide metabolism, cell wall loosening and cytoskeleton arrangement, thereby promoting fiber elongation. These findings suggest that GhACO1 is a key regulator of fiber development, and the application of "E6::GhACO1" strategy breaks the negative correlation between fiber quality and fiber yield, providing a novel route in formulating fiber improvement strategies in cotton.
查看更多>>摘要：Cellulose nanofibers (CNFs) have been shown to assemble at oil/water interface and act as Pickering emulsions stabilizers. Developing a simple approach to fabricate CNFs with tunable surface properties and elucidating the influence of the surface properties of the CNFs on their emulsifying performance are of great significance and highly demanded. Herein, a facile approach, namely FeCl3-catalyzed formic acid hydrolysis in combination with high pressure homogenization was reported to produce CNFs using industrial Kraft pulp as raw materials. The surface properties, especially the surface wettability of the CNFs could be easily adjusted by changing the hydrolysis time. Additionally, the emulsifying performance of the CNFs and the stability of CNF-stabilized Pickering emulsions were also evaluated. The obtained CNF-stabilized Pickering emulsions demonstrated great stability under various ionic strengths ranging from 0 to 1 M NaCl and high temperature of 80 ?. This work would greatly improve the possibility of sustainable production of CNFs for practical emulsions.
查看更多>>摘要：Photoluminescent carbon dots (CDs) inspire an emerging subclass of nanocarbons that is the topic of worldwide interest to smart materials with versatile functions. Despite an ideally sustainable biopolymer of industrial lignin with congenital phenylpropanoid skeleton, interior linkages and functional groups (e.g., -OCH3, -OH and -COOH), efficient lignin valorization is controversial by its heterogeneous structure. Herein, a "library " of CDs from technical lignin with gradient structure and narrow molecular dispersity is fabricated initiating by stepwise solvent fractionation, and lignin-derived CDs that function as the nanoprobe are thoroughly characterized with the interplay between fluorescence responses and sensing properties. Benefitting from the direction of molecular weights, beta-aryl ether, hydroxyl/carboxyl groups and particle size by refined lignin, their bimodal emissive CDs radiate the switchable and controllable blue-green color under a wide excitation span, which can be modulated to trimodule detect pH, silver ion and cysteine with an acceptable selectivity and sensitivity in a broad concentration scale. It thus is believed that this work not only delivers a facile strategy to overcome the lignin heterogeneity, but also paves the avenue to rationally nanoscale-design multifunctional lignin valorization with a perspective of broadening the biorefinery frontiers.
查看更多>>摘要：Design a novel and efficient adsorption-reutilization system is required urgently to overcome the difficulty of heavy metal-polluted water and secondary pollution of adsorbent-heavy metals. Here, a functional imitation wood-derived adsorbent was fabricated with carboxyl-functionalized ordered mesoporous tube bundles (named as OMTB@CA-IWA), which was successfully used in the high efficiency removal of heavy metal and then reused in chemiluminescence after adsorption. Experimental results indicated that high-density carboxyl groups were grafted onto the ordered mesoporous tube bundles of the delignified parasol via chemical modification, resulting in an efficient adsorption toward various heavy metal from wastewater. More importantly, the adsorbed spent adsorbent (M2+@OMTB@CA-IWA) was reused for the first time to act as heterogeneous catalytic cites for the chemiluminescence via an ingenious strategy in the system of N-(4-aminobutyl)-N-ethylisoluminol (ABEI) and H2O2. The prepared chemiluminescence system presented high intensity (1.42 x10(6) a.u.) and long duration time (over 10 h), which avoids the traditional secondary pollution and waste reprocessing. In view of the low price, easy availability and renewable of raw materials, the simple facile fabrication process, and the high efficiency of adsorbent as well as the interesting strategy for successive application in adsorption and chemiluminescence, the OMTB@CA-IWA will potentially bring about high speed development and widespread applications in wastewater treatment, biological imaging and cold light sources.
查看更多>>摘要：Soy protein isolate (SPI)-based nanocomposites are highly susceptible to degradation by microorganisms. To overcome this, this study explored the effects of incorporating curcumin into SPI-based nanocomposite films on the antimicrobial properties of the films. Cellulose nanofibril (CNF) was brushed with cetyltrimethylammonium chloride (CTAC) to prepare the modified drug-carrier system to better enable the binding of the lipophilic curcumin. Manifested by the strong hydrophobic interactions between curcumin and the CTAC molecules, curcumin was successfully loaded onto the modified CNF with encapsulation efficiency and loading amount of 97.79% and 9.78 mg/g, respectively. The curcumin hybrid film exhibited satisfactory antibacterial properties against E. coli and S. aureus due to the sustained release of curcumin, and they exhibited high antioxidant activities based on DPPH assays. The curcumin release rates were dependent on the solvent polarity; the release was faster in the 80% (v/v) and 50% (v/v) ethanol solutions than in the 20% (v/v) ethanol solution, and was diffusion-controlled. The oxidation of the CNF by sodium periodate before modification and loading resulted in the formation of dialdehyde groups that enabled Maillard reactions to occur with lysine residues of SPI peptides, which endowed films with desirable mechanical properties, including a maximum tensile strength of 11.86 MPa. This work broadened the research on the exploration of nanofiber-carrier systems for drug-loading/releasing to develop green composite films with strong antibacterial and mechanical properties.
Andrade, CatarinaFerreres, FedericoGomes, Nelson G. M.Gil-Izquierdo, Angel...
10页
查看更多>>摘要：Chukrasia tabularis A.Juss. is a canopy tree widely distributed in Asia and commonly used for construction-grade timber. While the residues resulting from the timber exploration constitute the major source of waste, other parts of the plant remain underutilized. Therefore, aiming the valorisation of a major residue resulting from C. tabularis wood industry, the leaves were here investigated on their potential content in bioactive constituents, but also on their capacity to modulate mediators and enzymes engaged in metabolic disorders, particularly those involved on the development and progression of diabetes. HPLC-DAD-ESI/MSn and UPLC-ESI-QTOF-MS2 characterization of a methanol extract obtained from the leaves, allowed the identification of 25 phenolic constituents, quercetin-3-O-rhamnoside being identified as the main bioactive. The leaf extract and the major flavonoid (quercetin-3-O-rhamnoside) were investigated on their impact towards a series of targets involved in the physiopathology of diabetes. The extract displayed significant scavenging properties against nitric oxide and superoxide radicals, inhibiting also lipid peroxidation and aldose reductase activity. While no noteworthy effects were noted on pancreatic lipase and a-amylase activity, the extract strongly inhibited a-glucosidase (IC50 = 21.14 mu g/mL) and proved to be ca. 5 times more effective than the benchmark drug, acarbose. Moreover, the leaf extract significantly inhibited also 5-lipoxygenase (5-LOX) (IC50 = 13.12 mu g/mL). Kinetic studies on a-glucosidase and 5-LOX activity disclosed a mixed type inhibition. Furthermore, C. tabularis extract reduced LPS-induced overproduction of NO, L-citrulline and IL-6 in activated RAW 264.7 macrophages. When individually assayed, quercetin-3-O-rhamnoside significantly contributed to the antiradical properties and inhibitory effects of the extract upon the enzymatic targets, but other phenolic bioactives appear also to underlie the recorded anti-inflammatory effects. Taken together, our results demonstrate that the leaves of C. tabularis are rich in phenolic constituents with a great potential to improve metabolic disorders. The evidenced bioactivity of this industrial product might feed R&D programs for the development of new drugs that might simultaneously improve glycaemic, oxidative and inflammatory benchmarks in diabetic patients.
查看更多>>摘要：Sclerotinia sclerotiorum (Lib.) de Bary is a crop-threatening fungus. Natural products are ideal antimicrobial agents to combat pathogens. They are considered a promising alternative to traditional synthetic fungicides due to low residual toxicity and possibly different modes of action on organisms. This work aims to develop a leading compound from natural products. Here, the antifungal activity of ten pentacyclic triterpenoids, including celastrol, pristimerin, asiatic acid, maslinic acid, ursolic acid, oleanic acid, quillaic acid, glycyrrhetinic acid, madecassic acid and corosolic acid were evaluated. Pristimerin exhibited an excellent activity against Sclerotinia sclerotiorum (S. sclerotiorum) with an EC50 value of 1.36 mu g/mL. Subsequently, the mode of action of pristimerin on S. sclerotiorum was further characterized by RNA-Seq-Based transcriptome profile. Pristimerin mainly inhibited oxidative phosphorylation, citrate cycle (TCA cycle) and blocked energy metabolism, and it also promoted the accumulation of ROS and disrupted the balance of the active oxygen metabolism system by affecting the activities of peroxidase (POD), catalase (CAT), superoxide dismutase (SOD) in the mycelial cells, and ultimately led to cell death. And beyond that, mitochondrial damage and changes in mycelial cells were also observed by transmission electron microscope (TEM) and scanning electron microscope (SEM). In general, these findings showed a molecular level perspective on the antifungal mechanism of pristimerin against S. sclerotiorum, and it could be used as a potential fungicide against S. sclerotiorum.
Pap, SabolcGaffney, Paul P. J.Zhao, QunyingKlein, Daniela...
13页
查看更多>>摘要：As a lignocellulose biomass, waste conifer brash (waste treetops and branches) from felled afforested peatland sites can be converted to biochar through pyrolysis, thus creating a potentially useful product. Here, we propose that brash from 'forest-to-bog' peatland restoration sites through conversion to biochar, could be utilised for nutrient (PO43 & xe213; -P and NH4+-N) removal at such restoration sites, or within the water sector. As a first step, we explore the factors involved in biochar production that will result in high nutrient adsorption efficiency and pyrolysis yield and low production cost (using a Plackett-Burman experimental design (PBD)). Central composite design (CCD) was used for further optimisation of pyrolysis time and temperature as the two most significant factors. Model predictions for an optimised biochar (OB) suggested pyrolysis conditions of 500 degrees C for 30 min could achieve the highest yield of 34.75 %, the lowest cost of 0.37 pound /kg, and the highest PO43 & xe213; -P and NH4+-N removal of 9.9 % and 65.2 %, respectively. Additionally, the OB morphology, structure and surface chemistry were characterised using different instrumental techniques which showed typical features for a wood-based biochar. While the OB did remove NH4+-N from solution (due to the presence of negatively charged functional groups), it did not remove significant amounts of PO43--P, indeed it leached PO43--P back into solution. Therefore, an unmodified biochar produced from conifer brash did not fulfil the aim of removing these two key nutrient pollutants for use in improving water quality at restoration sites. To address this challenge, the surface chemistry of the OB could be functionalised to increase its affinity toward both PO43 & xe213; -P and NH4+-N ions.
Fernandez-Silva, S. D. -Delgado, M. A.Ruiz-Mendez, M. V.Giraldez, I....
10页
查看更多>>摘要：This work explores the feasibility of using waste cooking oils (WCO) as eco-lubricants. Five WCO from different food facilities were studied. Three of them were fractionated into both lighter and heavier fractions by molecular distillation. A comprehensive chemical characterization (fatty acids distribution, polar compounds and acidity) was carried out on all WCOs and their fractions, which led to set relationships with the oils' properties (such as viscosity index, low temperature viscous flow behavior, oxidation resistance, etc.). It is worth mentioning the high viscosity index values found in waste cooking oils with both low total polar compounds and acidity level, as well as the benefit which acidity had on their fluidity at low temperature and their lubricity. Moreover, it was also noteworthy that the lighter fractions, merely constituted by free fatty acids (FFA), presented an improved oxidative resistance. The largest OOT enhancement, 12.4%, was found for the light fraction of a non-segregated oil. Moreover, a better thermal stability was shown by the heavier fractions. Finally, both fractions exhibited enhanced friction-reducing capability as compared to their parent WCO. The light fractions from a nonsegregated oil, a fast food restaurant oil and a deep-fried food establishment oil yielded wear reductions of 11.7%, 44.3% and 36.8%, respectively. Therefore, molecular distillation has been proved to be a key strategy to obtain more efficient liquid eco-lubricants.
查看更多>>摘要：As we all know, although petroleum-based plastic products greatly facilitated our life, they also caused great negative impacts on the environment and human health. In recent decades, cellulose nanofibers (CNFs) exhibit good degradability, renewability, and excellent mechanical properties, which is expected as a potential substitute for traditional petroleum-based plastic. Herein, we reported a facile preparation strategy of CNF dry powder based on TEMPO-oxidation process as well as the construction method of CNF-lignin bulk material which exhibited higher mechanical strength than most plastics. Among them, CNF-lignin bulk material containing 5% lignin performed excellent flexural strength (-198 MPa), which is much higher than that of most commercial plastics. Other important properties of this material such as super lightweight (-1.35 g/cm3), good toughness (-8.5 kJ/cm2), and high thermal stability (-295 degrees C) are also capable of meeting the requirements of replacing plastics. The mechanism investigation of lignin adding for improving the mechanical properties of CNF-lignin composite testified that the lignin in CNF-lignin composite filled the voids among CNFs and no chemical reactions happened between lignin and CNFs. Overall, this work offers a strategy to fabricate an environmentally friendly CNF-lignin bulk material, which is a promising alternative to petroleum-based plastics.
NSTL
Elsevier