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1.
J Transl Med ; 18(1): 110, 2020 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-32122362

RESUMO

BACKGROUND: Inflammatory damage following stroke aggravates brain damage, resulting in long-term neurological sequelae. The purpose of this study was to identify ways to reduce inflammatory reactions and to accelerate neuron regeneration after cerebral apoplexy. METHODS: We formulated a biomimetic vesicle, the leukosome, constituted by liposome, artificial long intergenic noncoding RNA (lincRNA)-EPS, and membrane proteins derived from macrophages and their physical-chemical characteristics were evaluated. Migration distance and cytotoxic levels were measured to determine the effect of lncEPS-leukosomes on lipopolysaccharide-activated microglia. An in vivo transient middle cerebral artery occlusion/reperfusion (tMCAO) model was established in mice, which were treated with lncEPS-leukosomes. Vesicle seepage, infiltration of inflammatory cells, cytotoxic levels in the cerebrospinal fluid, and neural stem cell (NSC) density were measured. RESULTS: Biomimetic vesicles with a homogeneous size increased lincRNA-EPS levels in activated microglia by 77.9%. In vitro studies showed that lincRNA-EPS inhibited the migration and cytotoxic levels of activated microglia by 63.2% and 43.6%, respectively, which promoted NSC proliferation and anti-apoptotic ability. In vivo data showed that leukosomes targeted to inflamed sites and lncEPS-leukosomes decreased the infiltration of inflammatory cells and cytotoxic levels by 81.3% and 48.7%, respectively. In addition, lncEPS-leukosomes improved neuron density in the ischemic core and boundary zone after tMCAO. CONCLUSIONS: The biomimetic vesicles formulated in this study targeted inflammatory cells and accelerated neuron regeneration by promoting inflammation resolution. This study may provide a promising treatment approach for accelerated neuron regeneration after cerebral apoplexy.


Assuntos
Isquemia Encefálica , RNA Longo não Codificante , Animais , Biomimética , Modelos Animais de Doenças , Infarto da Artéria Cerebral Média/complicações , Macrófagos , Camundongos , Microglia , Neurogênese , RNA Longo não Codificante/genética
2.
Arch Biochem Biophys ; 682: 108275, 2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-31962109

RESUMO

Stroke is one of the world's most deadly pathologies, and the rate of stroke recurrence is high. However, due to the complex nature of ischemia and reperfusion injury, there is presently no reliable treatment. The main factors driving brain damage from ischemic stroke are neuronal cell death resulting from oxidative stress, inflammation, and failure of the blood brain barrier. While under normal conditions, the blood brain barrier acts as a selectively permeable membrane allowing solutes and other substances to pass into the tissues of the central nervous system, ischemia and reperfusion alter the expression of tight junction proteins such as occludin, which leads to unmitigated perfusion and loss of homeostasis. Phoenixin-14 is a 14-amino acid neuropeptide that has been shown to play a role in regulating reproduction, blood sugar metabolism, pain, anxiety, and more recently, certain aspects of ischemic cardiac injury. In the present study, we found that phoenixin-14 confers protective effects against oxygen-glucose deprivation/reoxygenation (OGD/R) injury in bEnd.3 brain endothelial cells. Phoenixin-14 attenuated oxidative stress via downregulation of ROS and NOX1 and inhibited HMGB1 expression. Additionally, phoenixin-14 increased the expression of eNOS and NO, which play a protective role. Phoenixin-14 reduced endothelial monolayer permeability by increasing the expression of occludin. Finally, we found that the effects of phoenixin-14 on the expression of eNOS and occludin are dependent on the KLF2 transcriptional pathway, as evidenced by the results of our KLF2 knockdown experiment. Thus, phoenixin-14 may serve as a novel therapeutic agent for ischemic stroke.


Assuntos
Encéfalo/irrigação sanguínea , Células Endoteliais/metabolismo , Glucose/metabolismo , Inflamação/metabolismo , Neuropeptídeos/farmacologia , Oxigênio/metabolismo , Acidente Vascular Cerebral/metabolismo , Animais , Barreira Hematoencefálica/metabolismo , Encéfalo/metabolismo , Linhagem Celular , Células Endoteliais/efeitos dos fármacos , Homeostase , Humanos , Fatores de Transcrição Kruppel-Like/metabolismo , Camundongos , Óxido Nítrico Sintase Tipo III/metabolismo , Estresse Oxidativo , Peptídeos , Permeabilidade , Substâncias Protetoras/farmacologia , Traumatismo por Reperfusão/metabolismo
3.
Z Naturforsch C J Biosci ; 71(5-6): 165-80, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27049617

RESUMO

To explore abundant marine ascidian bioresources, four species from two orders have been compared in their chemical compositions. After a universal separation of the animal body into two fractions, all tunics have been found rich in carbohydrate contents, while all inner body tissues are richer in proteins. Cellulose is present almost exclusively in the tunics and more in the order Stolidobranchia, while more sulfated polysaccharides are present in Phlebobranchia species. Almost all proteins are collagens with a high essential amino acid index and high delicious amino acid (DAA) content. All fractions also have high contents of good-quality fatty acids and trace minerals but low toxic element contents, with different sterols and glycosaminoglycans. There are species-specific characteristics observed for vanadium accumulation and sterol structures which are also meaningful for ascidian chemotaxonomy and resource exploitation. It is suggested that in addition to the present utilizations of tunics for cellulose production and of some species' inner body tissues as human food, one should explore all species' inner body tissues as human foods and all tunics as food or animal feed with the contained cellulose as dietary fiber. Collagens, sulfated polysaccharides, glycosaminoglycans, sterols and trace elements could be explored as byproducts for, e.g. pharmaceutical and chemical industries.


Assuntos
Urocordados/química , Urocordados/metabolismo , Animais , Humanos , Especificidade da Espécie
4.
J Environ Sci (China) ; 28: 14-21, 2015 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-25662233

RESUMO

The increasing amount of cyanided tailings produced as a by-product has gained significant attention in recent years because of the rapid development of the gold industry and extensive exploitation of gold mineral resources. The effective use of these secondary resources is becoming an important and urgent problem for all environmental protection staff. Manganese-catalyzed ozonation for the pre-oxidation of cyanided tailings was studied and the effects of Mn2+ dosage, initial sulfuric acid concentration, ozone volume flow, temperature and agitation speed on pretreatment were examined. The optimum reaction conditions were observed to be: ore pulp density 2.5%, agitation speed 700 r/min, temperature 60°C, Mn2+ dosage 40 g/L, ozone volume flow 80 L/hr, initial sulfuric acid concentration 1 mol/L, and reaction time 6 hr. Under these conditions, the leaching rate of Fe and weight loss could reach 94.85% and 48.89% respectively. The leaching process of cyanided tailings by Mn2+/O3 was analyzed, and it was found that the leaching of pyrite depends on synergetic oxidation by high-valent manganese and O3, in which the former played an important part.


Assuntos
Poluentes Ambientais/química , Poluição Ambiental/prevenção & controle , Recuperação e Remediação Ambiental/métodos , Resíduos Industriais/prevenção & controle , Manganês/química , Ozônio/química , Catálise , Cianetos/química , Ouro/química , Ferro/química , Mineração , Oxirredução , Reciclagem , Ácidos Sulfúricos/química
5.
Plant J ; 74(2): 328-38, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23332001

RESUMO

It is of both theoretical and practical importance to develop a universally applicable approach for the fractionation and sensitive lignin characterization of lignin-carbohydrate complexes (LCCs) from all types of lignocellulosic biomass, both natively and after various types of processing. In the present study, a previously reported fractionation approach that is applicable for eucalyptus (hardwood) and flax (non-wood) was further improved by introducing an additional step of barium hydroxide precipitation to isolate the mannan-enriched LCC (glucomannan-lignin, GML), in order to suit softwood species as well. Spruce wood was used as the softwood sample. As indicated by the recovery yield and composition analysis, all of the lignin was recovered in three LCC fractions: a glucan-enriched fraction (glucan-lignin, GL), a mannan-enriched fraction (GML) and a xylan-enriched fraction (xylan-lignin, XL). All of the LCCs had high molecular masses and were insoluble or barely soluble in a dioxane/water solution. Carbohydrate and lignin signals were observed in (1) H NMR, (13) C CP-MAS NMR and normal- or high-sensitivity 2D HSQC NMR analyses. The carbohydrate and lignin constituents in each LCC fraction are therefore believed to be chemically bonded rather than physically mixed with one another. The three LCC fractions were found to be distinctly different from each other in terms of their lignin structures, as revealed by highly sensitive analyses by thioacidolysis-GC, thioacidolysis-SEC and pyrolysis-GC.


Assuntos
Carboidratos/química , Lignina/química , Picea/química , Biomassa , Espectroscopia de Ressonância Magnética
6.
Planta ; 239(5): 1079-90, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24531838

RESUMO

Xylan-lignin (XL), glucomannan-lignin (GML) and glucan-lignin (GL) complexes were isolated from spruce wood, hydrolyzed with xylanase or endoglucanase/ß-glucosidase, and analyzed by analytical pyrolysis and 2D-NMR. The enzymatic hydrolysis removed most of the polysaccharide moieties in the complexes, and the lignin content and relative abundance of lignin-carbohydrate linkages increased. Analytical pyrolysis confirmed the action of the enzymatic hydrolysis, with strong decreases of levoglucosane and other carbohydrate-derived products. Unexpectedly it also revealed that the hydrolase treatment alters the pattern of lignin breakdown products, resulting in higher amounts of coniferyl alcohol. From the anomeric carbohydrate signals in the 2D-NMR spectra, phenyl glycoside linkages (undetectable in the original complexes) could be identified in the hydrolyzed GML complex. Lower amounts of glucuronosyl and benzyl ether linkages were also observed after the hydrolysis. From the 2D-NMR spectra of the hydrolyzed complexes, it was concluded that the lignin in GML is less condensed than in XL due to its higher content in ß-O-4' ether substructures (62 % of side chains in GML vs 53 % in XL) accompanied by more coniferyl alcohol end units (16 vs 13 %). In contrast, the XL lignin has more pinoresinols (11 vs 6 %) and dibenzodioxocins (9 vs 2 %) than the GML (and both have ~13 % phenylcoumarans and 1 % spirodienones). Direct 2D-NMR analysis of the hydrolyzed GL complex was not possible due to its low solubility. However, after sample acetylation, an even less condensed lignin than in the GML complex was found (with up to 72 % ß-O-4' substructures and only 1 % pinoresinols). The study provides evidence for the existence of structurally different lignins associated to hemicelluloses (xylan and glucomannan) and cellulose in spruce wood and, at the same time, offers information on some of the chemical linkages between the above polymers.


Assuntos
Glucanos/química , Hidrolases/metabolismo , Lignina/química , Mananas/química , Picea/química , Madeira/química , Xilanos/química , Configuração de Carboidratos , Celulase/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidrólise , Lignina/metabolismo , Espectroscopia de Ressonância Magnética , Mananas/metabolismo , Madeira/metabolismo , Xilanos/metabolismo
7.
RSC Adv ; 14(7): 4835-4843, 2024 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-38318616

RESUMO

The sol-gel method is used to synthesize a new compound called Na3Fe0.8V1.2(PO4)3/C (NFVP/C), which has a crystal structure and belongs to the NASICON-type family. The dimensions of NFVP's unit cell are a = 8.717 (1) Å, c = 21.84 (1) Å, and V = 1437.27 (0) Å3. The Na‖NFVP/C battery provides a discharge potential of 3.43 V compared to Na+/Na, an intriguing rate capability of 76.2 mA h g-1 at 40C, and maintains an impressive capacity of 97.8% after 500 cycles at 5C. The excellent efficiency of Na3Fe0.8V1.2(PO4)3/C can be ascribed to its elevated Na+ conductivity and reduced energy barrier for sodium-ion diffusion. The NASICON-type Na3Fe0.8V1.2(PO4)3/C is a promising material for sodium-ion batteries.

8.
Biomacromolecules ; 14(9): 3073-80, 2013 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-23841747

RESUMO

The effects and mechanism of pulp delignification by laccases in the presence of redox mediators have been investigated on unbleached eucalyptus kraft pulp treated with laccases from Pycnoporus cinnabarinus (PcL) and Myceliophthora thermophila (MtL) and 1-hydroxybenzotriazole (HBT) and methyl syringate (MeS) as mediators, respectively. Determination of the corrected κ number in eucalyptus pulps after the enzymatic treatments revealed that the PcL-HBT system exhibited a more remarkable delignification effect than the MtL-MeS system. To obtain further insight, lignin-carbohydrate complexes were fractionated and subsequently characterized by nuclear magnetic resonance, thioacidolysis (followed by gas chromatography and size exclusion chromatography), and pyrolysis-gas chromatography-mass spectrometry (pyrolysis-GC-MS) analyses before and after the enzymatic treatments and their controls. We can conclude that the laccase-mediator treatments altered the lignin structures in such a way that more lignin was recovered in the xylan-lignin fractions, as shown by Klason lignin estimation, with smaller amounts of both syringyl (S) and guaiacyl (G) uncondensed units, as shown by thioacidolysis and gas chromatography, especially after the PcL-HBT treatment. The laccase-mediator treatment produced oxidation at Cα and cleavage of Cα and Cß bonds in pulp lignin, as shown by pyrolysis-GC-MS. The general mechanism of residual lignin degradation in the pulp by laccase-mediator treatments is discussed in light of the results obtained.


Assuntos
Lacase/química , Lignina/química , Xilanos/química , Ascomicetos/enzimologia , Biocatálise , Configuração de Carboidratos , Eucalyptus/química , Proteínas Fúngicas/química , Lignina/isolamento & purificação , Preparações de Plantas/química , Pycnoporus/enzimologia , Xilanos/isolamento & purificação
9.
Contrast Media Mol Imaging ; 2022: 3556330, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35854781

RESUMO

In order to explore the clinical application value of intelligent health care knowledge combined with closed reduction intramedullary nail fixation in elderly patients with intertrochanteric fracture of the femur, a retrospective analysis is performed on 80 elderly patients who received intertrochanteric surgery from January 2019 to January 2021. All patients were divided into study group and control group based on intelligent medical knowledge received or not. During the phase of treatment, both the two groups were treated with closed reduction and intramedullary nailing. The control group received conventional knowledge training and rehabilitation before and after the surgery, and the research group received additional intelligent medical knowledge health care. Observations of patients after bed and ground time are compared and the VAS score is used to evaluate the pain degree at 12 h, 24 h, and 48 h after surgery. Besides, the incidence of postoperative complications in the two groups is observed. From the clinical follow-up results, it is clearly evident that intramedullary nail fixation based on medical care knowledge can effectively improve the hip function and quality of life in patients, reduce postoperative pain, and improve the prognosis of elderly patients with femoral trochanteric fracture.


Assuntos
Pinos Ortopédicos , Fraturas do Quadril , Idoso , Atenção à Saúde , Fraturas do Quadril/cirurgia , Humanos , Qualidade de Vida , Estudos Retrospectivos , Resultado do Tratamento
10.
J Healthc Eng ; 2021: 9971236, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34976333

RESUMO

It was to explore the effect of the CT and X-ray examinations before the hip replacement to predict the collapse of the necrotic femoral head under the classification of medical big data based on the decision tree algorithm of the difference grey wolf optimization (GWO) and provide a more effective examination basis for the treatment of patients with the osteonecrosis of the femoral head (ONFH). From January 2019 to January 2021, a total of 152,000 patients with ONFH and hip replacement in the tertiary hospitals were enrolled in this study. They were randomly divided into two groups, the study sample-X group (X-ray examination results) and based-CT group (CT examination results)-76,000 cases in each group. The actual measurement results of the femoral head form the gold standard to evaluate the effect of the two groups of detection methods. The measurement results of X-ray and CT before hip replacement are highly consistent with the detection results of the physical femoral head specimens, which can effectively predict the collapse of ONFH and carry out accurate staging. It is worthy of clinical promotion.


Assuntos
Necrose da Cabeça do Fêmur , Cabeça do Fêmur , Big Data , Cabeça do Fêmur/diagnóstico por imagem , Necrose da Cabeça do Fêmur/diagnóstico por imagem , Humanos , Tomografia Computadorizada por Raios X , Raios X
11.
Biomacromolecules ; 11(4): 904-10, 2010 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-20175586

RESUMO

Lignosulfonates are by-products from the sulfite pulping process. During this process, lignin is liberated from pulp fibers through sulfonation and washed away. As a consequence, the lignosulfonate molecules contain both hydrophobic and hydrophilic moieties. Lignosulfonates are low-value products with limited performance and are used as such as binders, surfactants, and plasticizers in concrete. Lignosulfonates face strong competition from synthetic petroleum-based plasticizers with superior quality. Therefore, increasing the performance of lignosulfonates is desirable not only from a sustainability point of view but also to expand their usage. One important aspect that describes how well lignosulfonates can act as plasticizers is the molecular weight. In this paper, the molecular weight of four commercial lignosulfonates is increased through oxidation by two laccases without utilization of mediators. Different parameters to obtain maximal molecular weight increase were identified and the technical significance of the experiments is discussed.


Assuntos
Lacase/metabolismo , Lignina/análogos & derivados , Catálise , Cromatografia em Gel , Lignina/química , Lignina/metabolismo , Peso Molecular , Oxirredução , Espectroscopia de Infravermelho com Transformada de Fourier
12.
Carbohydr Polym ; 242: 116396, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32564848

RESUMO

Quantum dots (QD)/polymer materials have wide applications in biological imaging, clinical diagnostics, anti-counterfeiting materials, light-emitting devices and solar cells. The development of QD/cellulose nanofibrils (CNF) hybrids with a more perfect structure and excellent properties is important for improving known applications. A unique tunicate CNF (TCNF) was homogeneously blended with outstanding CdSe/CdS core/shell QD to prepare a novel QD/TCNF hybrid. The QD were monodispersed on a single TCNF fibril surface as an evenly distributed monolayer with an extremely high packing density and no visible aggregation. The prepared hybrid is an excellent platform nanomaterial which was demonstrated by its good writing fidelity when applied as a 1D ink and by its good processability in the preparation of 2D films with acceptable transparency and flexibility. This one-step direct blending approach provides a facile shortcut to effectively fabricate cellulose-based high-performance functional QD nanomaterials at the single-fibril level.

13.
Carbohydr Res ; 342(11): 1442-9, 2007 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-17509543

RESUMO

Uronic acids can be quantified either by a colorimetric determination after treatment with concentrated sulfuric acid and carbazole or by gas chromatography after methanolysis and subsequent acetylation. Both methods suffer from incomplete hydrolysis, an unavoidable degradation of the products to be analysed, and an inability to separate and quantify different types of uronic acids. In the present work, the fundamental chemistry involved in the two methods has been evaluated, and some modifications to increase their accuracy are suggested. By combining the two methods, a complete quantification of all individual types of uronic acids present in a sample can be achieved.


Assuntos
Ácidos Urônicos/análise , Ácidos Urônicos/química , Madeira/química , Xilanos/química , Betula/química , Carbazóis , Ácido Glucurônico/química , Ácidos Hexurônicos/análise , Ácidos Hexurônicos/química , Hidrólise , Ácidos Sulfúricos
14.
Bioresour Technol ; 98(16): 3061-8, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17141499

RESUMO

Steam explosion is an important process for the fractionation of biomass components. In order to understand the behaviour of lignin under the conditions encountered in the steam explosion process, as well as in other types of steam treatment, aspen wood and isolated lignin from aspen were subjected to steam treatment under various conditions. The lignin portion was analyzed using NMR and size exclusion chromatography as major analytical techniques. Thereby, the competition between lignin depolymerization and repolymerization was revealed and the conditions required for these two types of reaction identified. Addition of a reactive phenol, 2-naphthol, was shown to inhibit the repolymerization reaction strongly, resulting in a highly improved delignification by subsequent solvent extraction and an extracted lignin of uniform structure.


Assuntos
Lignina/química , Populus/química , Vapor , Madeira/química , Biomassa , Cromatografia em Gel , Hidrólise , Naftóis/química , Ressonância Magnética Nuclear Biomolecular
15.
ACS Appl Mater Interfaces ; 9(15): 13508-13519, 2017 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-28350431

RESUMO

This work reveals the structural variations of cellulose nanofibers (CNF) prepared from different cellulose sources, including softwood (Picea abies), hardwood (Eucalyptus grandis × E. urophylla), and tunicate (Ciona intestinalis), using different preparation processes and their correlations to the formation and performance of the films prepared from the CNF. Here, the CNF are prepared from wood chemical pulps and tunicate isolated cellulose by an identical homogenization treatment subsequent to either an enzymatic hydrolysis or a 2,2,6,6-tetramethylpiperidinyl-1-oxyl (TEMPO)-mediated oxidation. They show a large structural diversity in terms of chemical, morphological, and crystalline structure. Among others, the tunicate CNF consist of purer cellulose and have a degree of polymerization higher than that of wood CNF. Introduction of surface charges via the TEMPO-mediated oxidation is found to have significant impacts on the structure, morphology, optical, mechanical, thermal, and hydrophobic properties of the prepared films. For example, the film density is closely related to the charge density of the used CNF, and the tensile stress of the films is correlated to the crystallinity index of the CNF. In turn, the CNF structure is determined by the cellulose sources and the preparation processes. This study provides useful information and knowledge for understanding the importance of the raw material for the quality of CNF for various types of applications.

16.
Environ Sci Pollut Res Int ; 24(8): 7264-7273, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28101711

RESUMO

In this study, reduced graphene oxide (rGO) embedded with bimetallic nanoparticles of cobalt-manganese oxide (CoMn2O4) was fabricated by hydrothermal treatment. The obtained product was characterized and applied for the heterogeneous activation of peroxymonosulfate (PMS) to degrade acid orange 7 (AO7). The characterization results revealed that 10-20 nm nanosized CoMn2O4 was homogenously decorated on the surface of rGO. The effect of different CoMn2O4 loadings showed that catalyst with a CoMn2O4 contents higher than 20% performs stronger capability for catalytic degradation of AO7 compared to pure CoMn2O4. In a system containing 4 mM PMS and 0.05 g/L 50% CoMn2O4/rGO, 100% conversion of AO7 (70 mg/L) and 43% mineralization could be achieved within 12 and 60 min, respectively. Recycling experiment along with XRD data demonstrates good stability of the catalyst for five successive runs. Inhibition confirmation results suggest that surface-bound SO4•- and HO• radicals both played a key role in degradation of AO7. Therefore, this material demonstrates a very efficient catalytic performance for the degradation of organic dyes.


Assuntos
Compostos Azo , Benzenossulfonatos , Cobalto/química , Grafite/química , Compostos de Manganês/química , Óxidos/química , Poluentes Químicos da Água , Purificação da Água/métodos , Compostos Azo/análise , Compostos Azo/química , Compostos Azo/isolamento & purificação , Benzenossulfonatos/análise , Benzenossulfonatos/química , Benzenossulfonatos/isolamento & purificação , Nanopartículas/química , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
17.
Environ Sci Pollut Res Int ; 23(6): 5352-60, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26564189

RESUMO

The content and speciation of heavy metals can fundamentally affect the hydrolysis of sludge. This research study investigates the migration and transformation rule of heavy metals during the hydrolysis process by measuring the content of exchangeables (F1), bound to carbonates (F2), bound to Fe-Mn oxides (F3), bound to organic matter (F4), and residuals (F5) under different periods of time undergoing hydrolysis. The results show that the hydrolysis process generally stabilized Cu, Zn, Mn, Ni, Pb, Cr, and As by transforming the unstable states into structurally stable states. Such transformations and stabilization were primarily caused by the changes in local metal ion environment and bonding structure, oxidation of sulfides, pyrolyzation of organic matter, and evaporation of resulting volatile materials. An X-ray diffractometry (XRD) of the residuals conducted after hydrolysis indicated that hydrolysis did have a significant influence on the transportation and transformation of heavy metals.


Assuntos
Metais Pesados/química , Proteínas/isolamento & purificação , Esgotos/química , Carbonatos/química , Hidrólise , Óxidos/química , Sulfetos/química
18.
Materials (Basel) ; 9(3)2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-28773252

RESUMO

The industrial lignin used here is a byproduct from Kraft pulp mills, extracted from black liquor. Since lignin is inexpensive, abundant and renewable, its utilization has attracted more and more attention. In this work, lignin was used for the first time as binder material for LiFePO4 positive and graphite negative electrodes in Li-ion batteries. A procedure for pretreatment of lignin, where low-molecular fractions were removed by leaching, was necessary to obtain good battery performance. The lignin was analyzed for molecular mass distribution and thermal behavior prior to and after the pretreatment. Electrodes containing active material, conductive particles and lignin were cast on metal foils, acting as current collectors and characterized using scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge cycles. Good reversible capacities were obtained, 148 mAh·g-1 for the positive electrode and 305 mAh·g-1 for the negative electrode. Fairly good rate capabilities were found for both the positive electrode with 117 mAh·g-1 and the negative electrode with 160 mAh·g-1 at 1C. Low ohmic resistance also indicated good binder functionality. The results show that lignin is a promising candidate as binder material for electrodes in eco-friendly Li-ion batteries.

19.
Appl Biochem Biotechnol ; 125(3): 175-88, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15917581

RESUMO

Aspen wood was treated with steam at different time-temperature severity factors. Analysis of the amounts of acids released revealed a relationship between the acidity and the formation of furfural and hydroxymethyl furfural as degradation products from carbohydrates. It is suggested that two concurrent or consecutive mechanisms are responsible for the observed results: a homolytic cleavage and an acid hydrolysis of glucosidic linkages in the polysaccharides. By preimpregnating the wood with alkali, hydrolysis can be eliminated, resulting in a much cleaner depolymerization of the polysaccharides without any further acid-catalyzed degradation. The enzymatic digestibility of the steam-treated wood material for the formation of glucose was compared with that of steam-exploded wood. A more efficient route for glucose production from steam-exploded wood was found as long as the biomass-pretreated material was homogeneous and without shives.


Assuntos
Celulase/química , Celulose/química , Temperatura Alta , Lignina/química , Populus/química , Vapor , Madeira , beta-Glucosidase/química , Carboidratos/química , Concentração de Íons de Hidrogênio , Hidrólise , Tamanho da Partícula
20.
Lipids ; 50(10): 1009-27, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26233815

RESUMO

In order to establish Ciona intestinalis as a new bioresource for n-3 fatty acids-rich marine lipids, the animal was fractionated into tunic and inner body tissues prior to lipid extraction. The lipids obtained were further classified into neutral lipids (NL), glycolipids (GL) and phospholipids (PL) followed by qualitative and quantitative analysis using GC-FID, GC-MS, (1)H NMR, 2D NMR, MALDI-TOF-MS and LC-ESI-MS methods. It was found that the tunic and inner body tissues contained 3.42-4.08% and 15.9-23.4% of lipids respectively. PL was the dominant lipid class (42-60%) irrespective of the anatomic fractions. From all lipid fractions and classes, the major fatty acids were 16:0, 18:1n-9, C20:1n-9, C20:5n-3 (EPA) and C22:6n-3 (DHA). The highest amounts of long chain n-3 fatty acids, mainly EPA and DHA, were located in PL from both body fractions. Cholestanol and cholesterol were the dominant sterols together with noticeable amounts of stellasterol, 22 (Z)-dehydrocholesterol and lathosterol. Several other identified and two yet unidentified sterols were observed for the first time from C. intestinalis. Different molecular species of phosphatidylcholine (34 species), sphingomyelin (2 species), phosphatidylethanolamine (2 species), phosphatidylserine (10 species), phosphatidylglycerol (9 species), ceramide (38 species) and lysophospholipid (5 species) were identified, representing the most systematic PL profiling knowledge so far for the animal. It could be concluded that C. intestinalis lipids should be a good alternative for fish oil with high contents of n-3 fatty acids. The lipids would be more bioavailable due to the presence of the fatty acids being mainly in the form of PL.


Assuntos
Ciona intestinalis/química , Ácidos Graxos Ômega-3/análise , Fosfolipídeos/análise , Animais , Ciona intestinalis/anatomia & histologia , Glicolipídeos/análise , Espectroscopia de Prótons por Ressonância Magnética/métodos
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