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1.
Chem Commun (Camb) ; 59(85): 12723-12726, 2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37798956

RESUMO

A 5-nm-thick artificial solid electrolyte interface (SEI) was engineered for the hard carbon anodes of sodium-ion batteries. Benefiting from the artificial SEI, the hard carbon anode shows a significantly improved initial Coulombic efficiency of 94% and superior rate performance with a reversible capacity of 247 mA h g-1 after 800 cycles at 1C, 220 mA h g-1 after 400 cycles at 6C.

2.
Bioresour Technol ; 347: 126721, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35051568

RESUMO

Wheat straw was pretreated using ball milling (BM) promoted by solid particles (NaOH, NaCl, citric acid). NaOH showed the best synergistic interaction effect, due to the breakage of ß-1,4-glycosidic bonds among cellulose molecules by the alkali solid particles induced by BM. NaOH-BM pretreatment decreased the straw crystallinity from 46% to 21.4% and its average particle size from 398.3 to 50.6 µm in 1 h. After 4 h milling, the reducing-end concentration of cellulose increased by 3.8 times from 12.5 to 60.2 µM, with glucose yield increased by 2.1 times from 26.6% to 82.4% for 72 h enzymatic hydrolysis at cellulase loading of 15 FPU/g dry substrate. The pretreatment washing liquor was recycled for the re-treatment of partially pretreated biomass at 121 °C for 30 min, resulting in 99.4% glucose yield by enzymatic hydrolysis. BM assisted with alkali particles was an effective approach for improving biomass enzymatic saccharification.


Assuntos
Celulase , Triticum , Biomassa , Celulose , Hidrólise
3.
Bioresour Technol ; 320(Pt A): 124252, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33137639

RESUMO

Aromatic amines could be produced from organic wastes via catalytic pyrolysis with ammonia that served not only as a carrier gas but also as a reactant. Aromatic amines of 14.2 C% with selectivity of 57.6% were obtained from phenol-formaldehyde resins via pyrolysis over commercial HZSM-5-3 zeolite (Si/Al ratio of 80) catalyst at 650 °C. Significant synergetic effects have been observed when lignin was added, which improved aromatic amines yield by 32.2% to 11.8 C% at the mixing weight ratio of lignin to PF resins of 1:1. HZSM-5-3 was slightly deactivated after 3 cycles with acid sites loss. Catalytic co-pyrolysis of plastics and biomass wastes is a fast and effective method to produce aromatic amines.


Assuntos
Pirólise , Zeolitas , Aminas , Amônia , Biomassa , Catálise , Formaldeído , Temperatura Alta , Lignina , Fenóis , Polímeros
4.
Bioresour Technol ; 298: 122558, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31862395

RESUMO

Excessive utilization of fossil fuels has resulted in serious concerns about climate change. Integrating biorefinery technology to convert waste-derived-lignocellulosic biomass into biofuels and biopolymers has become an emerging topic toward our sustainable future. Pretreatment to fractionate the building block chemicals from the biomass is a crucial unit operation to ease the downstream processes in biorefinery. However, application of solvents and chemicals in the process can create many operational and environmental challenges in sensitive areas like highly populated cities. To shed light on how to determine a green biorefinery, this study presents the sustainability metrics of various pretreatment techniques and their operational risks during urbanization. The proposed green indexes include fractionation outputs, chemical recyclability, operational profile, and safety factors. In line with the design principles of lignin valorization, the issue of urban biomass and water-and-energy nexus are addressed to support future development and application of urban biorefinery for municipal waste management.


Assuntos
Benchmarking , Lignina , Biocombustíveis , Biomassa
5.
Bioresour Technol ; 250: 102-109, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29161568

RESUMO

The economic feasibility of high-concentration cellulosic bioethanol production remains challenging because it requires easily available feedstock and low energy consumption process. Simultaneous saccharification and fermentation (SSF) of sulfite pretreated Momentary pine slurry at 20% (w/w) loadings increased ethanol concentration from 59.3 g/L to 68.5 g/L by washing strategy. Effects of inhibitors in pretreatment liquor were further investigated. Besides HMF, furfural and acetic acid, other inhibitors and/or their synergistic effects proved to be responsible for a lower fermentability. To bypass the inhibition and achieve high-efficient bioethanol concentration, a fermentation temperature of 28 °C was optimized for both cell growth and ethanol production. Under the optimal conditions with prehydrolyzed 25% (w/w) whole undetoxified slurry, a high ethanol concentration (up to 82.1 g/L) were produced with a yield of 205 kg/ton Monterey pine in the SSF. Thus, this high cellulosic bioethanol production from Monterey pine makes it a potential strategy for biofuel production.


Assuntos
Biocombustíveis , Fermentação , Etanol , Furaldeído , Saccharomyces cerevisiae , Temperatura
6.
Guang Pu Xue Yu Guang Pu Fen Xi ; 37(1): 327-32, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30222301

RESUMO

Fleroxacin (FLRX) is a new member of the class of fluoroquinolones, its effects on human serum albumin (HSA) and the mechanism of action are poorly understood, Especially, the secondary structural alterations of HSA induced by FLRX and the inner filter effect, which resulted in a spurious decrease in the observed fluorescence intensity and affected the binding parameters calculated from it are not considered. In this paper, binding of FLRX to HSA has been studied using multi-spectroscopy and molecular modeling methods. Fluorescence spectra revealed that the observed fluorescence quenching of HSA by FLRX was due to a 1∶1 complex formation by a static quenching process with a constant of 105 L·mol-1. The thermodynamic parameters (ΔH and ΔS) were calculated to be -107.99 kJ·mol-1 and -240.99 J·mol-1·K-1 via the Van't Hoff equation, which indicated that hydrogen bond and van der Waals force were the dominant intermolecular force. From the synchronous fluorescence, FT-IR and three dimensional fluorescence spectra, it was evident that the binding of FLRX to HSA induced a conformational change in the protein, and the alterations of secondary structure were quantitatively calculated by the evidence from FTIR spectra with reductions of α-helices of about 18.3%, decreases of ß-sheet structures of about 9.6%, and increases of ß-turn structures of about 18.0%. Site marker competitive experiments showed that phenylbutazone and FLRX shared a common binding site Ⅰ corresponding to the subdomain Ⅱ A of HSA. The binding details between FLRX and HSA were further confirmed by molecular docking studies, which revealed that FLRX was bound at subdomain Ⅱ A through multiple interactions, such as hydrogen bond, hydrophobic and van der Waals, etc. The accurate and full basic data in the work is beneficial to clarify the binding mechanism of FLRX with HSA and is helpful for understanding its effect on protein function during the blood transportation process.


Assuntos
Fleroxacino/química , Albumina Sérica Humana/química , Sítios de Ligação , Dicroísmo Circular , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(8): 2141-6, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26672282

RESUMO

Three China trademarks of milk powder called Mengniu, Yili, Wandashan were taken as testing samples. Each of them mixed varied amount of starch in different gradient, which were consisted of 32 adulterated milk powder samples mixed with starch, was taken as standard samples for constructing predicted model. To those 32 samples, the reflecting spectrum characteristics in middle wave of near infrared spectrum with Near Infrared Spectrum Analyzer (Micro NIR 1700) produced by JDSU Ltd. USA were collected for five repeats in five different days. The time span was nearly two months. Firstly, we build the model used the reflecting spectrum characteristics of those samples with biomimetic pattern recognition (BPR) arithmetic to do the qualitative analysis. The analysis included the reliability of testing result and stability of the model. When we took ninety percent as the evaluation threshold of testing result of CAR (Correct Acceptance Rate) and CRR (Correct Rejection Rate), the lowest starch content of adulterate milk powder in all tested samples which the tested result were bigger than that abovementioned threshold was designated CAR threshold (CAR-T) and CRR threshold (CRR-T). CAR means the correct rate of accepting a sample which is belong to itself, CRR means correct rate of refusing to accept a sample which is not belong to itself. The results were shown that, when we constructed a model based on the near infrared spectrum data from each of three China trademark milk powders, respectively, if we constructed a model with infrared spectrum data tested in a same day, both the CAR-T and CRR-T of adulterate starch content of a sample can reach 0.1% in predicting the remainder infrared spectrum data tested within a same day. The three China trademarks of milk powder had the same result. In addition, when we ignored the trademarks, put the spectrum data of adulterate milk powder samples mixed with the same content of starch of three China trademarks milk powder together to construct a model, the CAR-T of mixed starch content of a sample may reach 0.1%, the CRR-T can reach 1%, if the model construction and predicting were performed with near infrared spectrum data tested in a same day. However, the CAR-T can just stably reach up to 5% and the CRR-T have the same result, if the model construction and predicting were crossly performed with mixed near infrared spectrum data tested in different days. Furthermore, the correct recognizing threshold mixed starch of a sample can stably reach up to 1% and the CAR-T can reach 5%, if the model construction was based on near infrared spectrum data combined the previous four days to predict the output of the another day. On the other hand, we also engaged quantitative analysis to the starch content in milk power with two kinds of arithmetic (PLSR, LS-SVR). In contrast with the testing outputs, the reliability of both the CAR-T and CRR-T in qualitative analysis was further validated.


Assuntos
Contaminação de Alimentos/análise , Leite/química , Amido/análise , Animais , Modelos Teóricos , Espectroscopia de Luz Próxima ao Infravermelho
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 34(4): 1064-9, 2014 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-25007630

RESUMO

Levofloxacin (LVFX) is widely used in clinical treatment due to it has a broad spectrum of in vitro activity against Gram-positive and Gram-negative bacteria. Human serum albumin (HSA) is the most abundant protein in plasma and constitutes approximately half of the protein founds in human blood. And more than 90% of the drugs used in people are bound to HSA. So it is commonly used for the investigation of drug-serum albumin interaction because the binding will significantly influence the absorption, distribution, metabolism excretion, stability and toxicity of the drugs. Therefore, detailed investigating the interaction of LVFX with HSA is very important to understand the pharmacokinetic behavior of the LVFX. In this paper, the interaction of LVFX and HSA has been studied fluorescence, UV, Fourier transform infrared (FT-IR) and molecular modeling method. The results indicated that LVFX induced the intrinsic fluorescence quenching of HSA though a static quenching procedure, and the effective binding constants (K(a)) were calculated to be 9.44 x 10(4) L x mol(-1) (294 K) and 2.74 x 10(4) L x mol(-1) (310 K) by used of the Stern-Volmer equation. According to the Vant's Hoff equation, the reaction was characterized by negative enthalpy (deltaH = -59.00 kJ x mol(-1)) and negative entropy (delta S = - 105.38 J x mol(-1) x K(-1)), indicated that the predominant forces in the LVFX-HSA complex were hydrogen bonding and van der Waals forces. By displacement measurements, the specific binding of LVFX in the vicinity of Site I of HSA was clarified. The binding distance of 3.66 nm between Trp214 and HSA was obtained by the Förster theory on resonance energy transfer. Furthermore, the binding details between LVFX and HSA were further confirmed by molecular docking studies, which were consistent with the experimental results. The alternations of protein secondary structure were calculated from FT-IR spectra. Upon formation of LVFX-HSA complexes, the amount of alpha-helical structures were decrease, but the numbers of beta-sheet structures, beta-turn structures and random structures were increase, respectively. This result indicated that LVFX induced unfolding of the polypeptides of HSA.


Assuntos
Levofloxacino/química , Albumina Sérica/química , Fluorescência , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Ligação Proteica , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
9.
Luminescence ; 28(6): 933-41, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23233363

RESUMO

This study was designed to examine the interaction of methacyline (METC) with human serum albumin (HSA) by multispectroscopy and a molecular modeling method under simulative physiological conditions. The quenching mechanism was suggested to be static quenching based on fluorescence and ultraviolet-visible (UV-Vis) spectroscopy. According to the Vant' Hoff equation, the values of enthalpy (∆H) and entropy change (∆S) were calculated to be -95.29 kJ/mol and -218.13 J/mol/K, indicating that the main driving force of the interaction between HSA and METC were hydrogen bonds and van der Waals's forces. By performing displacement measurements, the specific binding of METC in the vicinity of Sudlow's site I of HSA was clarified. An apparent distance of 3.05 nm between Trp214 and METC was obtained via the fluorescence resonance energy transfer (FRET) method. Furthermore, the binding details between METC and HSA were further confirmed by molecular docking studies, which revealed that METC was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, polar forces, hydrogen bonding, etc. The results of three-dimensional fluorescence and Fourier transform infrared (FTIR) spectroscopy showed that METC caused conformational and some microenvironmental changes in HSA and reduced the α-helix significantly in the range of 52.3-40.4% in HSA secondary structure. Moreover, the coexistence of metal ions such as Ca(2+), Al(3+), Fe(3+), Zn(2+), Cu(2+), Cr(3+) and Cd(2+) can decrease the binding constants of METC-HSA.


Assuntos
Metaciclina/química , Albumina Sérica/química , Sítios de Ligação , Humanos , Modelos Moleculares , Estrutura Terciária de Proteína , Espectrometria de Fluorescência , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
10.
Spectrochim Acta A Mol Biomol Spectrosc ; 103: 179-86, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23261611

RESUMO

This study was designed to examine the interaction of demeclocycline (DMCTC) with human serum albumin (HSA) by multi-spectroscopic and molecular docking methods. The inner filter effect was corrected before we calculated the binding parameters. Fluorescence and UV-vis spectroscopy revealed that DMCTC induced the fluorescence quenching of HSA though a static quenching procedure. Thermodynamic analysis by Van Hoff equation found enthalpy change (ΔH) and entropy change (ΔS) were -53.01 kJ mol(-1) and -65.13 J mol(-1)K(-1), respectively, which indicated hydrogen bond and van der Waals force were the predominant force in the binding process. According to fluorescence resonance energy transfer (FRET), the specific binding distances between Trp-214 (donor) and DMCTC (acceptor) were 3.18 nm. Through site marker competitive experiments, subdomain IIA of HSA has been assigned to possess the high-affinity binding site of DMCTC. The three dimensional fluorescence showed that the conformation of HSA was changed after its complexation with DMCTC, and the alternations of protein secondary structure were quantitatively calculated from FT-IR with reduction of α-helices content about 4.8%, ß-sheet from 30.3% to 21.6% and with increases of ß-turn from 15.6% to 22.2%. Furthermore, the binding details between DMCTC and HSA were further confirmed by molecular docking studies, which revealed that DMCTC was bound at subdomain IIA through multiple interactions, such as hydrophobic effect, polar forces and π-π interactions. Moreover, the coexist metal ions such as Al(3+), Fe(3+), Cu(2+), Cr(3+) and Cd(2+) can decrease the binding constants of DMCTC-HSA.


Assuntos
Antibacterianos/metabolismo , Demeclociclina/metabolismo , Albumina Sérica/metabolismo , Sítios de Ligação , Humanos , Simulação de Acoplamento Molecular , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Albumina Sérica/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica
11.
Mol Biosyst ; 8(5): 1446-51, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22337082

RESUMO

The interaction of nitrofurazone (NF) and human serum albumin (HSA) has been studied by fluorescence spectroscopy, FT-IR spectroscopy and molecular modeling methods. The results showed that the fluorescence of HSA was quenched by NF in a static quenching mechanism. Thermodynamic parameters revealed that hydrogen bonds and van der Waals force played the major role during the interaction. The calculated binding distance (r) indicated that the non-radioactive energy transfer came into being in the interaction between NF and HSA. HSA had a single class of binding site at Sudlow' site I in subdomain IIA for NF, which was verified by the displacement experiment. The molecular modeling study further confirmed the specific binding sites of NF on HSA, such as the interaction between N11 and N14 of NF with Lue 283 and Ser 287 predominately through hydrogen bonds. Three-dimensional fluorescence spectra indicated that the polarity around the tryptophan residues decreased and the conformation of HSA changed after adding NF. FT-IR spectra showed that NF could induce the polypeptides of HSA unfolding because it changed α-helix and ß-sheet into ß-turn and random structure of HSA.


Assuntos
Modelos Moleculares , Nitrofurazona/metabolismo , Albumina Sérica/metabolismo , Espectrometria de Fluorescência/métodos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Sítios de Ligação , Transferência de Energia , Humanos , Ligação de Hidrogênio , Cinética , Nitrofurazona/química , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Albumina Sérica/química , Termodinâmica
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 32(10): 2759-64, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23285882

RESUMO

Based on the self-ordered ring (SOR) fluorescence microscopic imaging technique on a hydrophobic glass slide with Zn2+ and cetyltrimethyl ammonium bromide (CTMAB) as sensitizer, and poly (vinyl alcohol) 124 (PVA-124) and NH3-NH4Cl (pH 10.00) as the medium, a method has been developed for determining sparfloxacin (SPFX) concentrations in chicken serum and residues in chicken tissues and manures. When the droplet volume was 0.20 microL, SPFX was determined in the range of 1.38 x 10(-13)-2.03 x 10(-12) mol x ring(-1) (or 6.90 x 10(-7)-1.02 x 10(-5) mol x L(-1)), and the limit of detection (LOD) was 14 fmol x ring (or 6.90 x 10(-8) mol x L(-1)). The recoveries of SPFX at all different spiked levels are in the range of 90.74%-106.61% when the methanol or acetonitrile were used as extracting agent, respectively, and the relative standard deviations (RSDs) are less than 3.0%. This study expands the applied fields of SOR technique in drug concentrations and residues determination.


Assuntos
Resíduos de Drogas/análise , Fluoroquinolonas/sangue , Carne/análise , Microscopia de Fluorescência/métodos , Animais , Galinhas , Fluoroquinolonas/metabolismo , Limite de Detecção , Esterco/análise
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