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1.
Sensors (Basel) ; 24(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38339491

RESUMEN

Optical coherence tomography angiography (OCTA) offers critical insights into the retinal vascular system, yet its full potential is hindered by challenges in precise image segmentation. Current methodologies struggle with imaging artifacts and clarity issues, particularly under low-light conditions and when using various high-speed CMOS sensors. These challenges are particularly pronounced when diagnosing and classifying diseases such as branch vein occlusion (BVO). To address these issues, we have developed a novel network based on topological structure generation, which transitions from superficial to deep retinal layers to enhance OCTA segmentation accuracy. Our approach not only demonstrates improved performance through qualitative visual comparisons and quantitative metric analyses but also effectively mitigates artifacts caused by low-light OCTA, resulting in reduced noise and enhanced clarity of the images. Furthermore, our system introduces a structured methodology for classifying BVO diseases, bridging a critical gap in this field. The primary aim of these advancements is to elevate the quality of OCTA images and bolster the reliability of their segmentation. Initial evaluations suggest that our method holds promise for establishing robust, fine-grained standards in OCTA vascular segmentation and analysis.


Asunto(s)
Oclusión de la Vena Retiniana , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Reproducibilidad de los Resultados , Oclusión de la Vena Retiniana/diagnóstico , Vasos Retinianos/diagnóstico por imagen , Angiografía
2.
Zhongguo Zhong Yao Za Zhi ; 49(2): 361-369, 2024 Jan.
Artículo en Zh | MEDLINE | ID: mdl-38403312

RESUMEN

The 4-coumarate: CoA ligase(4CL) is a key enzyme in the upstream pathway of phenylpropanoids such as flavonoids, soluble phenolic esters, lignans, and lignins in plants. In this study, 13 4CL family members of Arabidopsis thaliana were used as reference sequences to identify the 4CL gene family candidate members of Isatis indigotica from the reported I. indigotica genome. Further bioinformatics analysis and analysis of the expression pattern of 4CL genes and the accumulation pattern of flavonoids were carried out. Thirteen 4CL genes were obtained, named Ii4CL1-Ii4CL13, which were distributed on chromosomes 1, 2, 3, 4, and 6. The analysis of the gene structure and conserved structural domains revealed the intron number of I. indigotica 4CL genes was between 1 and 12 and the protein structural domains were highly conserved. Cis-acting element analysis showed that there were multiple response elements in the promoter sequence of I. indigotica 4CL gene family, and jasmonic acid had the largest number of reaction elements. The collinearity analysis showed that there was a close relationship between the 4CL gene family members of I. indigotica and A. thaliana. As revealed by qPCR results, the expression analysis of the 4CL gene family showed that 10 4CL genes had higher expression levels in the aboveground part of I. indigotica. The content assay of flavonoids in different parts of I. indigotica showed that flavonoids were mainly accumulated in the aboveground part of plants. This study provides a basis for further investigating the roles of the 4CL gene family involved in the biosynthesis of flavonoids in I. indigotica.


Asunto(s)
Isatis , Ligasas , Ligasas/genética , Isatis/genética , Regiones Promotoras Genéticas , Plantas/metabolismo , Flavonoides , Coenzima A Ligasas/genética , Coenzima A Ligasas/química , Coenzima A Ligasas/metabolismo
3.
Small ; 19(38): e2301472, 2023 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-37218011

RESUMEN

The combination of optical transparency and mechanical strength is a highly desirable attribute of wood-based glazing materials. However, such properties are typically obtained by impregnation of the highly anisotropic wood with index-matching fossil-based polymers. In addition, the presence of hydrophilic cellulose leads to a limited water resistance. Herein, this work reports on an adhesive-free lamination that uses oxidation and densification to produce transparent all-biobased glazes. The latter are produced from multilayered structures, free of adhesives or filling polymers, simultaneously displaying high optical clarity and mechanical strength, in both dry and wet conditions. Specifically, high values of optical transmittance (≈85.4%), clarity (≈20% with low haze) at a thickness of ≈0.3 mm, and highly isotropic mechanical strength and water resistance (wet strength of ≈128.25 MPa) are obtained for insulative glazes exhibiting low thermal conductivity (0.27 W m-1 K-1 , almost four times lower than glass). The proposed strategy results in materials that are systematically tested, with the leading effects of self-adhesion induced by oxidation rationalized by ab initio molecular dynamics simulation. Overall, this work demonstrates wood-derived materials as promising solutions for energy-efficient and sustainable glazing applications.

4.
Zhongguo Zhong Yao Za Zhi ; 48(6): 1510-1517, 2023 Mar.
Artículo en Zh | MEDLINE | ID: mdl-37005838

RESUMEN

Chalcone isomerase is a key rate-limiting enzyme in the biosynthesis of flavonoids in higher plants, which determines the production of flavonoids in plants. In this study, RNA was extracted from different parts of Isatis indigotica and reverse-transcribed into cDNA. Specific primers with enzyme restriction sites were designed, and a chalcone isomerase gene was cloned from I. indigotica, named IiCHI. IiCHI was 756 bp in length, containing a complete open reading frame and encoding 251 amino acids. Homology analysis showed that IiCHI was closely related to CHI protein of Arabidopsis thaliana and had typical active sites of chalcone isomerase. Phylogenetic tree analysis showed that IiCHI was classified into type Ⅰ CHI clade. Recombinant prokaryotic expression vector pET28a-IiCHI was constructed and purified to obtain IiCHI recombinant protein. In vitro enzymatic analysis showed that the IiCHI protein could convert naringenin chalcone into naringenin, but could not catalyze the production of liquiritigenin by isoliquiritigenin. The results of real-time quantitative polymerase chain reaction(qPCR) showed that the expression level of IiCHI in the aboveground parts was higher than that in the underground parts and the expression level was the highest in the flowers of the aboveground parts, followed by leaves and stems, and no expression was observed in the roots and rhizomes of the underground parts. This study has confirmed the function of chalcone isomerase in I. indigotica and provided references for the biosynthesis of flavonoid components.


Asunto(s)
Arabidopsis , Isatis , Isatis/genética , Proteínas de Plantas/metabolismo , Filogenia , Arabidopsis/genética , Flavonoides , Clonación Molecular
5.
Biomacromolecules ; 22(12): 5033-5041, 2021 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-34813283

RESUMEN

Recently, because of the unique properties of anisotropic and isotropic structures, there are more research studies on anisotropic hydrogels. We prepared a gradient anisotropic carboxymethyl cellulose hydrogel (CMC-Al3+) by directionally diffusing aluminum chloride solution. The orientation of carboxymethyl cellulose (CMC) chains is perpendicular to the direction of aluminum ion diffusion. The degree of cross-linking and orientation gradually decrease along the direction of aluminum ion diffusion. Compared with anisotropic hydrogels prepared by other methods, the hydrogels prepared by directionally diffusing aluminum ion solution have a gradient lamellar structure. Because of the large amount of aluminum ions in CMC-Al3+, the hydrogel shows good sensing performance. CMC-Al3+ is packaged with PVC electrical flame retardant tape to produce a strain sensor used to detect human tiny movements, which can accurately and stably monitor tiny movements. Hydrogel-based strain sensors can be widely used in the fields of human-computer intelligence, human-computer interaction, and wearable devices in the future.


Asunto(s)
Hidrogeles , Dispositivos Electrónicos Vestibles , Carboximetilcelulosa de Sodio/química , Humanos , Hidrogeles/química
6.
Biomacromolecules ; 22(12): 5204-5213, 2021 12 13.
Artículo en Inglés | MEDLINE | ID: mdl-34787399

RESUMEN

The purpose of this research is to develop strong and tough wood-based hydrogels, which are reinforced by an aligned cellulosic wood skeleton. The hypothesis is that improved interfacial interaction between the wood cell wall and a polymer is of great importance for improving the mechanical performance. To this end, a facile and green approach, called ultraviolet (UV) grafting, was performed on the polyacrylamide (PAM)-infiltrated wood skeleton without using initiators. An important finding was that PAM-grafted cellulose nanofiber (CNF) architectures formed in the obtained hydrogels under UV irradiation, where CNFs themselves serve as both initiators and cross-linkers. Moreover, an alkali swelling treatment was utilized to improve the accessibility of the wood cell wall before UV irradiation and thus facilitate grafting efficiency. The resulting alkali-treated Wood-g-PAM hydrogels exhibited significantly higher tensile properties than those of the Wood/PAM hydrogel and were further assembled into conductive devices for sensor applications. We believe that this UV grafting strategy may facilitate the development of strong wood-based composites with interesting features.


Asunto(s)
Hidrogeles , Nanofibras , Celulosa , Conductividad Eléctrica , Madera
7.
Molecules ; 24(3)2019 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-30736411

RESUMEN

In this study, the Micrococcus luteus K-3 glutaminase was successfully over-expressed in the GRAS (Generally Recognized as Safe) Bacillus subtilis strain 168 by integration of the Mglu gene in the 16S rDNA locus. This was done in order to screen a strain producing high levels of recombinant glutaminase from the selected candidates. The transcription of the glutaminase genes in the B. subtilis 168 chromosome and the expression of glutaminase protein was further assessed by qPCR, SDS-PAGE analysis and an enzyme activity assay. To further increase the production of glutaminase, the nprB and nprE genes, which encode specific proteases, were disrupted by integration of the Mglu gene. After continuous cell culturing without the addition of antibiotics, the integrated recombinant strains showed excellent genetic stability, demonstrating favorable industrialization potential. After the fermentation temperature was optimized, a 5-L bioreactor was used for fed-batch fermentation of the recombinant glutaminase producing strain at 24 °C, and the highest enzyme activity achieved was approximately 357.6 U/mL.


Asunto(s)
Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Proteínas Bacterianas/genética , ADN Ribosómico/genética , Endopeptidasas/genética , Fermentación , Glutaminasa/biosíntesis , Regulación Bacteriana de la Expresión Génica , Glutaminasa/metabolismo , Temperatura
8.
J Nanosci Nanotechnol ; 18(1): 668-675, 2018 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-29768893

RESUMEN

In this work, novel porous cellulose nanofibrils (CNF)/poly(vinyl alcohol) (PVA) hydrogels were prepared using the hybrid solvent of dimethyl sulfoxide (DMSO)/water, followed by freezing/thawing process. Structure, swelling, mechanical and thermal properties of CNF/PVA were explored. The results revealed that porous hydrogels were formed by using the hybrid solvent of DMSO/water, and the pore sizes of hydrogels were controlled by the concentration of CNF. The porous structure of the composite hydrogels can strongly enhance the swelling properties as expected. Compared with pure PVA hydrogels, a 150% improvement in compressive strength were achieved by the hybrid solvent. And the increment of compressive strength depended on the concentration of the CNF. Moreover, the addition of CNF improved the thermal stability of the PVA hydrogels significantly. The low cost, nontoxic and high-performance nanoreinforced hydrogels may have a promising application in tissue engineering fields.

9.
Colorectal Dis ; 2017 Oct 04.
Artículo en Inglés | MEDLINE | ID: mdl-28977739

RESUMEN

AIM: The aim of this study was to investigate the detailed, in situ, morphology of Denonvilliers fascia (DVF) in cadavers using sheet plastination and confocal microscopy and to review and describe the optimal anterior plane for mobilisation of the distal rectum.. METHOD: Six, male cadavers (age range, 46-87 years) were prepared as six sets of transverse (x2), coronal (x1) and sagittal (x3) plastinated sections which were examined under a confocal laser scanning microscope. RESULTS: In this study a consistent space between the anterior rectal wall and the posterior surface of the prostate and seminal vesicles above the level of the perineal body was termed the prerectal space. Within that prerectal space we identified fibres which take their origin from the external urethral sphincter (EUS), together with others from the longitudinal rectal muscle (LRM) and the connective tissue sheaths of neurovascular bundles. Neither the EUS- nor the LRM-originated fibres were continuous with the endopelvic fascia;they are interposed laterally and cranially by multiple neurovascular bundles. Further, our results suggest that the peritoneum does not descend deep within the prerectal space. CONCLUSION: This study reveals the undisturbed, in situ, structural detail of membrane-like structures in the prerectal space and confirms that the optimal plane for anterolateral mobilization of the rectum is posterior to the multilayered DVF. This article is protected by copyright. All rights reserved.

10.
J Reprod Dev ; 63(5): 481-488, 2017 Oct 18.
Artículo en Inglés | MEDLINE | ID: mdl-28690291

RESUMEN

Geminin plays a critical role in cell cycle regulation by regulating DNA replication and serves as a transcriptional molecular switch that directs cell fate decisions. Spermatogonia lacking Geminin disappear during the initial wave of mitotic proliferation, while geminin is not required for meiotic progression of spermatocytes. It is unclear whether geminin plays a role in pre-meiotic DNA replication in later-stage spermatogonia and their subsequent differentiation. Here, we selectively disrupted Geminin in the male germline using the Stra8-Cre/loxP conditional knockout system. Geminin-deficient mice showed atrophic testes and infertility, concomitant with impaired spermatogenesis and reduced sperm motility. The number of undifferentiated spermatogonia and spermatocytes was significantly reduced; the pachytene stage was impaired most severely. Expression of cell proliferation-associated genes was reduced in Gmnnfl/Δ; Stra8-Cre testes compared to in controls. Increased DNA damage, decreased Cdt1, and increased phosphorylation of Chk1/Chk2 were observed in Geminin-deficient germ cells. These results suggest that geminin plays important roles in pre-meiotic DNA replication and subsequent spermatogenesis.


Asunto(s)
Geminina/genética , Infertilidad Masculina/genética , Meiosis/genética , Espermatogénesis/genética , Animales , Replicación del ADN/genética , Eliminación de Gen , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Espermatocitos/fisiología
11.
Int J Biol Macromol ; 256(Pt 1): 128326, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38000571

RESUMEN

Recent reports had shown that microplastics could be transferred to organisms through various channels, severely and adversely affecting organisms' health and their physiological functions. Therefore, there remained an urgency to adopt an effective and environmentally friendly method to extract microplastics from water. In this paper, a cationic-modified d-DCPG aerogel with a three-dimensional network structure was successfully prepared by a directional freeze-drying technology in which double-aldehyde-modified cellulose nanofiber (CNF) was used as the matrix, betaine chloride hydrazide (GT) provided modification, and polyvinyl alcohol (PVA) provided cross-linking function. Aerogels had an excellent adsorption capacity (145.05 mg/g) for microplastics in aqueous environment, and when the pH was from 10 to 4, it exhibited an excellent adsorption efficiency from 90.01 % to 97.61 %; an excellent adsorption efficiency after 8 cycles (>89 %); pseudo-second-order kinetics and Freundlich adsorption isotherm had a high fitting effects on the adsorption process and adsorption results, respectively. And ultraviolet analysis also verified the occurrence of adsorption behavior. These results showed that d-DCPG aerogels had an excellent application prospects in microplastics removal in river, lake, reservoir, and marine environments.


Asunto(s)
Microplásticos , Plásticos , Adsorción , Aldehídos , Betaína , Cationes
12.
Int J Biol Macromol ; 255: 128188, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37977473

RESUMEN

Petroleum-based plastics are useful but they pose a great threat to the environment and human health. It is highly desirable yet challenging to develop sustainable structural materials with excellent mechanical and optical properties for plastic replacement. Here, we report a simple and efficient method to manufacture high-performance all-biobased structural materials from cellulosic wood skeleton (WS) and gelatin via oxidation and densification. Specifically, gelatin was grafted to the oxidized cellulose wood skeletons (DAWS) and then physically crosslinked via Tannic acid (TA), resulting in a significant enhancement of the material properties. Notably, only a mild pressure was applied during the drying process to form a densified TA/Gelatin/transparent wood film(TWF). The developed TA/Gelatin/TWF (thickness:100 ± 12 µm) exhibited a desirable combination of high strength (∼154.59 MPa), light transmittance (86.2 % at 600 nm), low haze (16.7 %), high water stability (wet strength: ∼130.13 MPa) and ultraviolet blocking efficacy which surpass most of the petroleum-based plastics. In addition, due to the all bio-based origins (wood and gelatin), TA/Gelatin/TWF are easily biodegradable under natural conditions, leading to less impact on the environment. These findings would hold promises for exploring high-quality all bio-based wood composites as eco-friendly alternatives to substitute plastics with wide applications, e.g. anti-counterfeiting, UV protection, and flexible electricals.


Asunto(s)
Celulosa Oxidada , Petróleo , Humanos , Gelatina , Madera
13.
J Colloid Interface Sci ; 666: 529-539, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38613975

RESUMEN

Elastic carbon aerogels have promising applications in the field of wearable sensors. Herein, a new strategy for preparing carbon aerogels with excellent compressive strength and strain, shape recovery, and fatigue resistance was proposed based on the structure design and carbonization optimization of nanocellulose-based precursor aerogels. By the combination of directional freezing and zinc ion cross-linking, bacterial cellulose (BC)/alginate (SA) composite aerogels with high elasticity and compressive strength were first achieved. The existance of zinc ions also significantly improved the carbon retention rate and inhibited structural shrinkage, thus making the carbon aerogels retain ultra-high elasticity and fatigue resistance after compression. Moreover, the carbon aerogel possessed excellent piezoresistive pressure sensing performance with a wide detection range of 0-7.8 kPa, high sensitivity of 11.04 kpa-1, low detection limit (2 % strain), fast response (112 ms), and good durability (over 1,000 cycles). Based on these excellent properties, the carbon aerogel pressure sensors were further successfully used for human motion monitoring, from joint motion to and speech recognition.


Asunto(s)
Alginatos , Carbono , Celulosa , Elasticidad , Geles , Dispositivos Electrónicos Vestibles , Carbono/química , Geles/química , Humanos , Celulosa/química , Alginatos/química , Anisotropía , Tamaño de la Partícula , Propiedades de Superficie , Zinc/química
14.
Front Cell Infect Microbiol ; 14: 1371916, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38716199

RESUMEN

Porcine epidemic diarrhea virus (PEDV) has become a challenging problem in pig industry worldwide, causing significant profit losses. Lactobacillus rhamnosus GG (LGG) has been regarded as a safe probiotic strain and has been shown to exert protective effects on the intestinal dysfunction caused by PEDV. This study evaluated the effect of LGG on the gut health of lactating piglets challenged with PEDV. Fifteen piglets at 7 days of age were equally assigned into 3 groups (5 piglets per group): 1) control group (basal diet); 2) PEDV group: (basal diet + PEDV challenged); 3) LGG + PEDV group (basal diet + 3×109 CFU/pig/day LGG + PEDV). The trial lasted 11 days including 3 days of adaptation. The treatment with LGG was from D4 to D10. PEDV challenge was carried out on D8. PEDV infection disrupted the cell structure, undermined the integrity of the intestinal tract, and induced oxidative stress, and intestinal damage of piglets. Supplementation of LGG improved intestinal morphology, enhanced intestinal antioxidant capacity, and alleviated jejunal mucosal inflammation and lipid metabolism disorders in PEDV-infected piglets, which may be regulated by LGG by altering the expression of TNF signaling pathway, PPAR signaling pathway, and fat digestion and absorption pathway.


Asunto(s)
Infecciones por Coronavirus , Suplementos Dietéticos , Lacticaseibacillus rhamnosus , Virus de la Diarrea Epidémica Porcina , Probióticos , Enfermedades de los Porcinos , Animales , Porcinos , Probióticos/administración & dosificación , Enfermedades de los Porcinos/prevención & control , Infecciones por Coronavirus/veterinaria , Infecciones por Coronavirus/terapia , Estrés Oxidativo , Intestinos/patología , Polvos , Mucosa Intestinal/patología
15.
Animals (Basel) ; 14(10)2024 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-38791729

RESUMEN

Porcine epidemic diarrhea virus (PEDV) has developed as a global problem for the pig business, resulting in significant financial losses. Black soldier fly extract (BFE) has been proven to improve intestinal growth in pigs after weaning. Consequently, the goal of the present investigation was to explore the effects of BFE supplementation on intestinal function in PEDV-infected piglets. Eighteen piglets were randomly allocated to three groups: control, PEDV, and BFE + PEDV. The piglets in the BFE + PEDV group received 500 mg/kg BW of BFE orally for seven days from day 4 to 10 of the study. On day 9 of the study, six pigs from each group received either clean saline or PEDV solution at a dosage of 106 TCID50 (50% tissue culture infectious dose) per pig. On day 11, samples of blood and intestine were taken for additional investigation. The results indicated a significant decrease in the average daily gain (ADG) of piglets infected with PEDV (p < 0.05). Additionally, PEDV infection led to an alteration of blood indexes and a reduction in plasma D-xylose concentration and villi height in the small intestine, while it increased plasma diamine oxidase activity and small intestinal crypt depth in piglets (p < 0.05). The PEDV infection significantly reduced antioxidant enzyme activity in plasma and the gut, including total superoxide dismutase and catalase, while increasing contents of oxidation-relevant products such as malondialdehyde and hydrogen peroxide in piglets. Moreover, PEDV infection increased the mRNA expression level of antiviral-related genes (p < 0.05). Nutritional supplementation with BFE improved intestinal histomorphological indicators and reduced oxidative stress produced by PEDV infection in piglets. Interestingly, BFE could significantly promote the mRNA expression level of antiviral-related genes in the ileum (p < 0.05). Overall, the preliminary results suggest that dietary BFE could improve intestinal function in piglets after PEDV infection. Currently, the findings put a spotlight on the role of BFE in the prevention and treatment of PED in piglets.

16.
Int J Biol Macromol ; 263(Pt 1): 130176, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38368977

RESUMEN

Smart gating membranes have drawn much attention due to the controllable pore structure. Herein, a smart gating membrane with dual responsiveness was prepared from bacteria cellulose (BC) grafted with pH- and temperature-responsive polymers. By external stimulation, the average pore size of the membrane can be controlled from 33.75 nm to 144.81 nm, and the pure water flux can be regulated from 342 to 2118 L·m-2·h-1 with remarkable variation in the pH range of 1-11 and temperature range of 20-60 °C. The adjustability of pore size is able to achieve the gradient selective separation of particles and polymers with different sizes. In addition, owing to the underwater superoleophobicity and the nanoscale pore structure, the membrane separation efficiencies of emulsified oils are higher than 99 %. Moreover, the controllable pore size endows the membrane with good self-cleaning performance. This nanocellulose-based smart gating membrane has potential applications in the fields of controllable permeation, selective separation, fluid transport, and drug/chemical controlled release systems.


Asunto(s)
Polímeros , Agua , Temperatura , Agua/química , Polímeros/química , Celulosa , Concentración de Iones de Hidrógeno
17.
Math Biosci Eng ; 20(7): 12404-12432, 2023 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-37501448

RESUMEN

This systematic review aims to investigate recent developments in the area of arc fault detection. The rising demand for electricity and concomitant expansion of energy systems has resulted in a heightened risk of arc faults and the likelihood of related fires, presenting a matter of considerable concern. To address this challenge, this review focuses on the role of artificial intelligence (AI) in arc fault detection, with the objective of illuminating its advantages and identifying current limitations. Through a meticulous literature selection process, a total of 63 articles were included in the final analysis. The findings of this review suggest that AI plays a significant role in enhancing the accuracy and speed of detection and allowing for customization to specific types of faults in arc fault detection. Simultaneously, three major challenges were also identified, including missed and false detections, the restricted application of neural networks and the paucity of relevant data. In conclusion, AI has exhibited tremendous potential for transforming the field of arc fault detection and holds substantial promise for enhancing electrical safety.

18.
Int J Biol Macromol ; 235: 123884, 2023 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-36870642

RESUMEN

Currently, cellulose-based aerogel materials are a hot topic owing to their high specific surface area and high porosity, as well as the green, degradable and biocompatible characteristics of cellulosic materials. Modification of cellulose to enhance the adsorption properties of cellulose-based aerogels has important research significance in solving the problem of water body pollution. In this paper, cellulose nanofibers (CNFs) were modified with polyethyleneimine (PEI), and modified aerogels with directional structures were prepared by a simple reaction and freeze-drying method. The adsorption behavior of the aerogel followed the adsorption kinetic models and isotherm models. More significantly, the aerogel could rapidly adsorb microplastics, reaching equilibrium within 20 min. Furthermore, the fluorescence displayed directly expresses the occurrence of the adsorption behavior of the aerogels. Therefore, the modified cellulose nanofiber aerogels were of reference significance for microplastic removal from water bodies.


Asunto(s)
Nanofibras , Nanofibras/química , Microplásticos , Plásticos , Polietileneimina , Agua/química , Adsorción , Celulosa/química
19.
Int J Biol Macromol ; 225: 79-89, 2023 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-36460246

RESUMEN

Anisotropic hydrogels have attracted extensive attention because they are similar to natural hydrogel-like materials and exhibit superiority and new functions that isotropic hydrogels cannot. Here, we fabricated strong and tough carboxymethyl cellulose-based conductive hydrogels with oriented hierarchical structures through pre-stretching, solvent displacement induced phase separation, and subsequent ionic crosslinking immobilization. Solvent displacement made the pre-stretched carboxymethyl cellulose-based polymer network more dense and linear, while the toughness of the hydrogel was further improved under the effect of phase separation. Strong and tough hydrogels were prepared by combining pre-stretching and phase separation; the variation range (tensile strength of 2.24-6.19 MPa and toughness of 19.41-22.92 MJ/m3) can be adjusted by the stretching ratio. Compared with traditional carboxymethyl cellulose-based hydrogels, the tensile strength and toughness were increased by 49 times and 15 times, respectively. In addition, the hydrogels had good underwater stability, ion cross-linking made the hydrogels have good conductivity, and the directional stratification structure gave the hydrogels conductive anisotropy. These characteristics give hydrogel sensors broad application prospects in flexible wearable devices, anisotropic sensors, and intelligent underwater devices.


Asunto(s)
Carboximetilcelulosa de Sodio , Hidrogeles , Anisotropía , Conductividad Eléctrica , Solventes
20.
J Hazard Mater ; 441: 129965, 2023 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-36122524

RESUMEN

Oil spills frequently occur in the ocean, and adsorption is one of the effective ways to deal with oil spills. Compared with other adsorbent materials, biomass aerogel has superior selective adsorption capacity. CNF/SA aerogels with good mechanical properties (340 kPa at 90 % strain) and high adsorption capacity (88.91 g/g) were prepared by mixing cellulose nanofibers (CNF) with sodium alginate (SA) through bidirectional freeze-drying, ionic crosslinking, and surface modification to effectively solve the ocean oil spill problem. The bidirectional freeze-drying technology is a green and efficient technique for preparing layered microstructured composite aerogels. The prepared aerogels have a three-dimensional interpenetrating lamellar structure, low density (24.2 mg/cm3), high porosity (97.85 %), and high hydrophobicity (WCA = 144.5°), can be calibrated and used repeatedly. It has potential applications in water-oil separation and can be used as an absorbent for effectively treating oil spills in the ocean environment.


Asunto(s)
Incrustaciones Biológicas , Nanofibras , Alginatos , Incrustaciones Biológicas/prevención & control , Celulosa/química , Geles/química , Interacciones Hidrofóbicas e Hidrofílicas , Nanofibras/química , Océanos y Mares , Agua/química
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