38 research outputs found

    Fluorine-Free Oil Absorbents Made from Cellulose Nanofibril Aerogels

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    Aerogels based on cellulose nanofibrils (CNFs) have been of great interest as absorbents due to their high absorption capacity, low density, biodegradability, and large surface area. Hydrophobic aerogels have been designed to give excellent oil absorption tendency from water. Herein, we present an in situ method for CNF surface modification and hydrophobic aerogel preparation. Neither solvent exchange nor fluorine chemical is used in aerogel preparations. The as-prepared hydrophobic aerogels exhibit low density (23.2 mg/cm<sup>ā€“3</sup>), high porosity (98.5%), good flexibility, and solvent-induced shape recovery property. Successful surface modification was confirmed through field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and water contact angle measurements. The hydrophobic aerogels show high absorption capacities for various oils, depending on liquid density, up to 47Ɨ their original weight but with low water uptake (<0.5 g/g aerogel)

    High Efficiency Dye-Sensitized Solar Cells Based on Three-Dimensional Multilayered ZnO Nanowire Arrays with ā€œCaterpillar-likeā€ Structure

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    A 3D ZnO nanowire-based dye-sensitized solar cell (DSSC) with unique ā€œcaterpillar-likeā€ structure was designed. Because of the significant improvement of the total ZnO nanowire surface area, the amount of light absorption was substantially increased. This increase in the light harvesting efficiency enables us to achieve an overall power conversion efficiency as high as 5.20%, which is the highest reported value to date for ZnO nanowire-based DSSCs. A branched-multilayered design of ZnO nanowire arrays grown from ZnO nanofiber seed layers proves to be very successful in fabricating 3D ZnO nanowire arrays. Practically, electrospun ZnO nanowires were used as the seeds in multilayer growth of ZnO nanowire arrays with a unique ā€œcaterpillar-likeā€ structure. This unique structure significantly enhances the surface area of the ZnO nanowire arrays, leading to higher short-circuit currents. Additionally, this design resulted in closer spacing between the nanowires and more direct conduction pathways for electron transfer. Thus, the open-circuit voltage was so significantly improved as a direct result of the reduction in electron recombination

    Hydrogels Prepared from Cross-Linked Nanofibrillated Cellulose

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    Nanocomposite hydrogels were developed by cross-linking nanofibrillated cellulose with polyĀ­(methyl vinyl ether-co-maleic acid) and polyethylene glycol. The cross-linked hydrogels showed enhanced water absorption and gel content with the addition of nanocellulose. In addition, the thermal stability, mechanical strength, and modulus increased with an increase in the amount of nanocellulose in hydrogels, and this can be attributed to efficient cross-linking between the nanocellulose and the matrix. The addition of softwood nanocellulose showed much higher strength and strain properties in the hydrogels than with the addition of hardwood nanocellulose. The enhanced physical properties confirm that in situ cross-linking of nanofibrillated cellulose with the matrix polymer forms hydrogels that are not just blends of starting materials but are distinctively unique and formed by cross-linking interactions between the filler and matrix

    Structure Analysis of Pine Barkā€‘, Residueā€‘, and Stem-Derived Light Oil and Its Hydrodeoxygenation Products

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    Three constituents of loblolly pine (stem, residue, and bark) were independently pyrolyzed to produce light oil. The chemical structures of the light oils were analyzed using GC-MS, <sup>1</sup>H NMR, <sup>13</sup>C NMR, and HSQC-NMR. The experimental results indicate that levoglucosan observed in the light oil is the major product from cellulose pyrolysis. Furanic and phenolic monomers are derived from hemicellulose and lignin, respectively. The light oil hydrodeoxygenation reaction study was carried out using carbon-supported ruthenium as a catalyst. Light oils from all three constituents were independently upgraded under 8 MPa hydrogen gas at 300 Ā°C for 2 h. After the upgrading process, the aromatic rings were hydrogenated and the oxygen-containing functional groups were extensively removed. According to <sup>1</sup>H NMR, the percentage of the CH<sub><i>n</i></sub>O peak area for stem, residue, and bark decreases by 90.03%, 77.84%, and 94.98%, respectively, compared to that for the pre-HDO light oil After upgrading, the carbon yields are 83.31% for the bark and approximately 100% for both the stem and the residue. The results indicate that ruthenium can hydrogenate carbonyl (Cī—»O) bonds, furan ring, and aromatic ring as well as cleave the aliphatic Cā€“O and Cā€“C bonds by hydrogenolysis. However, it cannot cleave the ether and ester type bonds

    Direct Ink Write 3D Printed Cellulose Nanofiber Aerogel Structures with Highly Deformable, Shape Recoverable, and Functionalizable Properties

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    Recent advancements in cellulosic aerogels have been extensive, but the lack of reproducible customization over the aerogelā€™s overall 3D structure has limited their ability to adapt to different application requirements. In this paper, high pressure homogenization and 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) modified cellulose nanofiber (T-CNF) was printed using direct-ink-write (DIW) into customizable 3D structures. After freeze-drying and cross-linking, highly deformable and shape recoverable T-CNF aerogel 3D structures were obtained. The 3D printed parts have a porosity of 98% and density of 26 mg/cm<sup>3</sup>. Due to their sustainability, biocompatibility, ultralight weight with high porosity, and deformability, the resultant aerogels have great potential for applications in thermal insulation, shock/vibration damping, and tissue engineering. In addition, the 3D printed T-CNF aerogels were templated to impart hydrophobicity and electromechanical properties. The resultant aerogels demonstrated potential for oil/water separation, and electronic related applications

    Data_Sheet_1_Altered expression of inflammation-associated molecules in striatum: an implication for sensitivity to heavy ion radiations.docx

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    Background and objectiveHeavy ion radiation is one of the major hazards astronauts face during space expeditions, adversely affecting the central nervous system. Radiation causes severe damage to sensitive brain regions, especially the striatum, resulting in cognitive impairment and other physiological issues in astronauts. However, the intensity of brain damage and associated underlying molecular pathological mechanisms mediated by heavy ion radiation are still unknown. The present study is aimed to identify the damaging effect of heavy ion radiation on the striatum and associated underlying pathological mechanisms.Materials and methodsTwo parallel cohorts of rats were exposed to radiation in multiple doses and times. Cohort I was exposed to 15ā€‰Gy of 12C6+ ions radiation, whereas cohort II was exposed to 3.4ā€‰Gy and 8ā€‰Gy with 56Fe26+ ions irradiation. Physiological and behavioural tests were performed, followed by 18F-FDG-PET scans, transcriptomics analysis of the striatum, and in-vitro studies to verify the interconnection between immune cells and neurons.ResultsBoth cohorts revealed more persistent striatum dysfunction than other brain regions under heavy ion radiation at multiple doses and time, exposed by physiological, behavioural, and 18F-FDG-PET scans. Transcriptomic analysis revealed that striatum dysfunction is linked with an abnormal immune system. In vitro studies demonstrated that radiation mediated diversified effects on different immune cells and sustained monocyte viability but inhibited its differentiation and migration, leading to chronic neuroinflammation in the striatum and might affect other associated brain regions.ConclusionOur findings suggest that striatum dysfunction under heavy ion radiation activates abnormal immune systems, leading to chronic neuroinflammation and neuronal injury.</p

    Image_7_Bupleurum marginatum Wall.ex DC in Liver Fibrosis: Pharmacological Evaluation, Differential Proteomics, and Network Pharmacology.TIF

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    <p>Liver fibrosis is a common pathological feature of many chronic liver diseases. Bupleurum marginatum Wall.ex DC (ZYCH) is a promising therapeutic for liver fibrosis. In this study, 25 compounds were isolated from ZYCH, and the effects of ZYCH on DMN-induced liver fibrosis in rats were evaluated. The optimal effect group (H-ZYCH group) was selected for further proteomic analysis, and 282 proteins were altered in comparison to the DMN model group (FC > 1.2 or < 0.83, p < 0.05). Based on GO annotation analysis, clusters of drug metabolism, oxidative stress, biomolecular synthesis and metabolism, positive regulation of cell growth, extracellular matrix deposition, and focal adhesion were significantly regulated. Then networks of the altered proteins and compounds was generated by Cytoscape. Importantly, triterpenoid saponins and lignans had possessed high libdock scores, numerous targets, important network positions, and strong inhibitory activity. These findings may suggest that triterpenoid saponins and lignans are important active compounds of ZYCH in liver fibrosis and targeted by proteins involved in liver fibrosis. The combination of network pharmacology with proteomic analysis may provide a forceful tool for exploring the effect mechanism of TCM and identifying bioactive ingredients and their targets.</p

    Aerogel Microspheres from Natural Cellulose Nanofibrils and Their Application as Cell Culture Scaffold

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    We demonstrated that ultralight pure natural aerogel microspheres can be fabricated using cellulose nanofibrials (CNF) directly. Experimentally, the CNF aqueous gel droplets, produced by spraying and atomizing through a steel nozzle, were collected into liquid nitrogen for instant freezing followed by freeze-drying. The aerogel microspheres are highly porous with bulk density as low as 0.0018 g cm<sup>ā€“3</sup>. The pore size of the cellulose aeogel microspheres ranges from nano- to macrometers. The unique ultralight and high porous structure ensured high moisture (āˆ¼90 g g<sup>ā€“1</sup>) and water uptake capacity (āˆ¼100 g g<sup>ā€“1</sup>) of the aerogel microspheres. Covalent cross-linking between the native nanofibrils and cross-linkers made the aerogel microspheres very stable even in a harsh environment. The present study also confirmed this kind of aerogel microspheres from native cellulose fibers can be used as cell culture scaffold

    Table_1_Bupleurum marginatum Wall.ex DC in Liver Fibrosis: Pharmacological Evaluation, Differential Proteomics, and Network Pharmacology.DOCX

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    <p>Liver fibrosis is a common pathological feature of many chronic liver diseases. Bupleurum marginatum Wall.ex DC (ZYCH) is a promising therapeutic for liver fibrosis. In this study, 25 compounds were isolated from ZYCH, and the effects of ZYCH on DMN-induced liver fibrosis in rats were evaluated. The optimal effect group (H-ZYCH group) was selected for further proteomic analysis, and 282 proteins were altered in comparison to the DMN model group (FC > 1.2 or < 0.83, p < 0.05). Based on GO annotation analysis, clusters of drug metabolism, oxidative stress, biomolecular synthesis and metabolism, positive regulation of cell growth, extracellular matrix deposition, and focal adhesion were significantly regulated. Then networks of the altered proteins and compounds was generated by Cytoscape. Importantly, triterpenoid saponins and lignans had possessed high libdock scores, numerous targets, important network positions, and strong inhibitory activity. These findings may suggest that triterpenoid saponins and lignans are important active compounds of ZYCH in liver fibrosis and targeted by proteins involved in liver fibrosis. The combination of network pharmacology with proteomic analysis may provide a forceful tool for exploring the effect mechanism of TCM and identifying bioactive ingredients and their targets.</p

    CD4<sup>+</sup> T cell signals provided during priming and recall phase are required for optimal secondary responses.

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    <p>(<b>a</b>) A schematic protocol. After 90 days of immunization, total CD8<sup>+</sup> T cells containing memory CTLs were purified from WT B6 mice with helped CTLs or MHCII<sup>āˆ’/āˆ’</sup> mice with unhelped CTLs, adoptively transferred in equal numbers into the naĆÆve secondary recipients, WT and MHCII<sup>āˆ’/āˆ’</sup> mice (āˆ¼15Ɨ10<sup>6</sup>/mouse), and assessed for recall potential after boosting. (<b>b</b>) Three days after adoptive transfer of helped or unhelped memory CTLs into naĆÆve WT and MHCII<sup>āˆ’/āˆ’</sup> mice, all the mice groups were boosted with AdVova and monitored for the expansion of memory CTLs 6.5 days later. The values represent mean %Ā±SD of OVA-specific tetramer<sup>+</sup> CTLs in total CD8<sup>+</sup> T cell population and are representative of two independent experiments with five to six mice per group. **<i>P</i><0.01, versus MHCII<sup>āˆ’/āˆ’</sup> mice with helped or unhelped memory CTLs.</p
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