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1.
Int J Biol Macromol ; 253(Pt 7): 127368, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37838129

RESUMO

Recyclable, non-toxic, and degradable biological substrates contribute significantly to super-wetting surfaces. In this work, we prepared magnetic micro-nano super-hydrophobic surfaces through a robust solution with magnetic modified lignin particles as the supporting structure. A novel PDMS (polydimethylsiloxane)/magnetic lignin particle (lignin@Fe3O4)/PDA sponge composite was fabricated. Through dopamine (DA) self-polymerization, covalent deposition of magnetic lignin (ML), and PDMS silane modification, the magnetic super-hydrophobic polyurethane sponge composite (Sponge-P) was synthesized so that the Fe3O4 nanoscale microspheres wrapped with microscale lignin magnetic particles adhered to the sponge surface tighter and were barely dislodged. The as-prepared Sponge-P displayed excellent flexibility and a water contact angle of up to 152.2°. The super-hydrophobic sponge prepared with the proposed method was acid-base stable (pH = 2-12), self-cleaning, and suitable for high-salinity seawater. The magnetic super-hydrophobic sponge has good oil-water separation ability and can absorb 43 times its own weight of oil. In the meantime, due to the introduction of magnetic materials into lignin, we not only constructed micro-nanostructures to improve the surface super-hydrophobicity, but also made Sponge-P have the function of magnetic recovery, which has a unique advantage in treating oily wastewater.


Assuntos
Bandagens , Lignina , Fenômenos Físicos , Dopamina , Fenômenos Magnéticos
2.
Chempluschem ; 85(5): 866-875, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32378808

RESUMO

Porous carbons have shown considerable potential in catalysis as either as supports or metal-free catalysts. Various methods based on solution chemistry have been intensively developed for the preparation of porous carbon-based catalysts with controllable morphology, pore structure, surface chemical property as well as the desired active sites. Nowadays, mechanochemical synthesis, a re-emerging strategy, has become more and more popular in the synthesis of porous carbons, due to its feasibility and high synthetic efficiency under solvent-free condition. This Minireview presents recent advances in the mechanochemical synthesis of porous carbons by ball milling, and their applications in catalysis. It starts a brief introduction of the characteristics and work mechanism of ball milling, and then discuss the preparation of porous carbons as metal-free catalysts and carbon-supported metal catalysts. Finally, some issues and further opportunities for the mechanochemical synthesis of porous carbon-based catalysts are proposed and discussed.

3.
Adv Mater ; 32(21): e2000447, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32253798

RESUMO

Hard carbon attracts considerable attention as an anode material for sodium-ion batteries; however, their poor rate capability and low realistic capacity have motivated intense research effort toward exploiting nanostructured carbons in order to boost their comprehensive performance. Ultramicropores are considered essential for attaining high-rate capacity as well as initial Coulombic efficiency by allowing the rapid diffusion of Na+ and inhibiting the contact of the electrolyte with the inner carbon surfaces. Herein, hard carbon nanosheets with centralized ultramicropores (≈0.5 nm) and easily accessible carbonyl groups (CO)/hydroxy groups (OH) are synthesized via interfacial assembly and carbonization strategies, delivering a large capacity (318 mA h g-1 at 0.02 A g-1 ), superior rate capability (145 mA h g-1 at 5.00 A g-1 ), and approximately 95% of reversible capacity below 1.00 V. Notably, a new charge model favoring fast capacitive sodium storage with dual potential plateaus is proposed. That is, the deintercalation of Na+ from graphitic layers is manifested as the low-potential plateau region (0.01-0.10 V), contributing to stable insertion capacity; meanwhile, the surface desodiation process of the CO and OH groups corresponds to the high-potential plateau region (0.40-0.70 V), contributing to a fast capacitive storage.

4.
Chemistry ; 26(9): 2041-2050, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31785014

RESUMO

A green and convenient solid-state method assisted by mechanical energy is employed for the synthesis of boron (B) and nitrogen (N) co-doped porous carbons (B,N-Cs). Glutamic acid (Glu) and boric acid (H3 BO3 ) are used as the N-containing carbon precursor and boron source, respectively. This method is easy to perform and proved to be efficient towards co-doping B and N into the carbon matrix with high contents of B (7 atom %) and N (10 atom %). By adjusting the molar ratio of H3 BO3 to Glu, the surface chemical states of B and N could be readily modulated. When increasing H3 BO3 dosage, the pore size of B,N-Cs could be tuned ranging from micropores to mesopores with a Brunauer-Emmett-Teller (BET) surface area up to 940 m2 g-1 . Finally, the B,N-Cs were applied as metal-free catalysts for the cycloaddition of CO2 to epoxides, which outperform the N-doped carbon catalyst (NC-900) and the physically mixed catalyst of NC-900/B4 C. The enhanced activity is attributed to the cooperative effect between B and N sites. X-ray photoelectron spectroscopy (XPS) analysis reveals that BN3 in the B,N-Cs serves as a critical active site for the cooperative catalysis.

5.
J Colloid Interface Sci ; 557: 519-527, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31546117

RESUMO

Introduction of hierarchical porous structure and heteroatom in porous carbons are always effective approaches to improve the capacitive performance for supercapacitor. However, it is still a challenge to achieve the desired structure characteristics by a convenient one-step synthesis. Herein, C16mimPF6, an ionic liquid, was introduced in the self-assembly process of poly-benzoxazine to obtain a unique skin-tissue-bone structured hierarchical porous carbon with homogeneous N, P co-doping after carbonization. As the key component, C16mimPF6 works not only as a structure-directing agent to form a hierarchical structure through microphase separation mechanism, thereby promoting the transfer of ion and electron, but also as a heteroatom precursor to contribute an additional pseudocapacitance by doping phosphorus atoms on carbon matrix. The obtained porous carbon displays a high gravimetric capacitance (Cg) of 209 F g-1 (especially in the carbons prepared without corrosive activation step), a good volumetric capacitance (Cv) of 132 F cm-3 and an excellent area-normalized capacitance (Ca) of 35 µF cm-2. Overall, this work opens a new way to design the polymer-derived carbons with easy heteroatoms doping and hierarchical porous structure.


Assuntos
Benzoxazinas/química , Carbono/química , Carbono/metabolismo , Líquidos Iônicos/química , Nitrogênio/química , Fósforo/química , Polímeros/química , Capacitância Elétrica , Condutividade Elétrica , Técnicas Eletroquímicas , Eletrodos , Estrutura Molecular , Porosidade , Propriedades de Superfície
6.
ACS Appl Mater Interfaces ; 10(50): 43946-43952, 2018 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-30475571

RESUMO

A lithium ion capacitor (LIC) is a hybrid energy storage device that combines the energy storage mechanism of lithium ion batteries and supercapacitors and presents their complementary features. However, imbalances of the capacity and kinetics between cathode and anode still remain challenges. Herein, to address the issue of low capacity in the cathode, we constructed a morning glory like porous material crimped from an opening sandwich structure consisting of a hard carbon inner layer and soft carbon outer layer, by coating graphene oxide containing flaky phenolic resin with coal tar pitch followed by carbonization and activation. Both the hard@soft carbon integrated design and the reduced graphene oxide network cocontributed to a favorable electrical conductivity and a developed microporosity. To deal with the sluggish kinetics limitation of the anode, a structure-optimized MnO@C electrode prepared by pore creation of CO2 from an MnCO3@polydopamine precursor was chosen due to its excellent rate performance. The LIC with this configuration can deliver a maximum energy density of 117.6 Wh kg-1 and an favorable capacity retention of 76% after 3000 cycles at 2050 W kg-1. Furthermore, the energy density of 27.8 Wh kg-1 can still be delivered even at a high power density of 10250 W kg-1. In general, this well-designed hybrid capacitor has a potential to make up the gap between lithium ion batteries and supercapacitors.

7.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(6): 1572-6, 2015 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-26601369

RESUMO

The feasibility of a combination method of surface-enhanced Raman spectroscopy (SERS) technology and linear regression algorithm was investigated for rapid quantitative analysis of pesticide residues in honey. The total of 30 samples was applied in the experiment with dimethoate pesticide residues range from 1 ppm to 10 ppm. The samples were divided into calibration set (20) and prediction set (10). The substrate of Klarite with an inverted pyramidal structure was adopted for improvement of the relative intensity of the majority of Raman shift peaks. The comparative analysis was carried out between SERS spectra of dimethoate pesticide residues in honey samples and conventional Raman spectra of dimethoate standard sample. And four characteristic Raman shift peaks at the wavenumbers of 867, 1 065, 1 317 and 1 453 cm(-1) were found, which were related with the vibrational information of dimethoate molecule. The relationship was developed by linear regression algorithm between the intensity of Raman shift and the concentration of dimethoate pesticide residues. The 10 new samples in the prediction set were applied to evaluate the performance of the models. By comparison, the optimal model was obtained with the characteristic Raman shift peak of 867 cm(-1). The higher correlation coefficient of prediction of 0.984 and lower root mean square error of prediction of 0.663 ppm were obtained. The detection limit of this method was 2 ppm, which was close to the maximum levels of pesticide residue detection limits. Experimental results showed that it was feasible to rapidly analyze quantitative of pesticide residues in honey with the combination method of SERS technology and linear regression algorithm. Compared with the conventional method coupled with the suitable pretreatment, the combination method of SERS technology and linear regression method could analyze the dimethoate pesticide residues in honey, and it also provided an optional method for rapid quantitative analysis pesticide residues in other agricultural products.


Assuntos
Mel/análise , Resíduos de Praguicidas/análise , Análise Espectral Raman
8.
Guang Pu Xue Yu Guang Pu Fen Xi ; 33(12): 3216-20, 2013 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-24611373

RESUMO

The feasibility was explored in determination of reducing sugar content of potato granules based on wavelet compression algorithm combined with near-infrared spectroscopy. The spectra of 250 potato granules samples were recorded by Fourier transform near-infrared spectrometer in the range of 4000- 10000 cm-1. The three parameters of vanishing moments, wavelet coefficients and principal component factor were optimized. The optimization results of three parameters were 10, 100 and 20, respectively. The original spectra of 1501 spectral variables were transfered to 100 wavelet coefficients using db wavelet function. The partial least squares (PLS) calibration models were developed by 1501 spectral variables and 100 wavelet coefficients. Sixty two unknown samples of prediction set were applied to evaluate the performance of PLS models. By comparison, the optimal result was obtained by wavelet compression combined with PLS calibration model. The correlation coefficient of prediction and root mean square error of prediction were 0.98 and 0.181%, respectively. Experimental results show that the dimensions of spectral data were reduced, scarcely losing effective information by wavelet compression algorithm combined with near-infrared spectroscopy technology in determination of reducing sugar in potato granules. The PLS model is simplified, and the predictive ability is improved.


Assuntos
Carboidratos/análise , Solanum tuberosum/química , Espectroscopia de Luz Próxima ao Infravermelho , Calibragem , Análise dos Mínimos Quadrados , Análise de Ondaletas
9.
Asian Pac J Cancer Prev ; 13(7): 3427-30, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22994772

RESUMO

AIM: The significance of the mucinous adenocarcinoma in TNM staging and prognosis for colorectal tumor patients is still controversial. The aim was to provide a meta-analysis for TNM staging and prognostic features of colorectal tumors. METHODS: 30 individual case-control studies were finally included into this meta-analysis, involving a total of 444,489 cancer cases and 45,050 mucinous adenocarcinomas, of relations with TNM staging and prognostic features. RESULTS: Compared to non-mucinous adenocarcinoma patients, the TNM IV stage accounted for a larger percentage of mucinous adenocarcinomas (OR=1.48, 95%CI 1.28-1.71, POR<0.001) and the prognosis was significantly poor (HR=1.06, 95%CI 1.04-1.08, P<0.001). After heterogeneity testing, the results was similar to the holistic approach outcome (HR=1.48, 95%CI 1.35-1.62, P<0.001). CONCLUSION: Compared to patients with non-mucinous adenocarcinomas, mucinous adenocarcinoma patients with later TNM staging make up a big percentage, and mucinous adenocarcinoma is an independent risk factor for poor prognosis.


Assuntos
Adenocarcinoma Mucinoso/patologia , Neoplasias Colorretais/patologia , Estudos de Casos e Controles , Método Duplo-Cego , Humanos , Estadiamento de Neoplasias/métodos , Prognóstico , Fatores de Risco
10.
Cell Biochem Funct ; 28(5): 420-5, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20589737

RESUMO

Tip growth of pollen tubes is essential for higher plant sexual reproduction and has been proposed to be highly regulated by the ubiquitin/proteasome pathway (UPP). The dynamics of mitochondria and the functions of the UPP on mitochondrial dynamics during pollen tube development are still poorly understood. In the present study, using real-time laser scanning and transmission electron microscope, it was revealed that mitochondria in Picea wilsonii, are either ellipsoid or filamentous with various lengths. Time-lapse images indicated that the two forms of mitochondria interconvert frequently through opposite process of fusion and fission. Examination of mitochondrial morphology during four key stages of in vitro pollen tube development revealed a link between mitochondrial remodeling and the process of pollen tube elongation. We also report that MG132, a specific proteasome inhibitor, not only strongly disturbed the mitochondrial remodeling but also significantly reduced mitochondrial membrane potential during pollen tube development. This finding provides new insight into the function of the proteasome in tip growth of pollen tubes.


Assuntos
Picea/crescimento & desenvolvimento , Tubo Polínico/crescimento & desenvolvimento , Complexo de Endopeptidases do Proteassoma/metabolismo , Leupeptinas/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Microscopia Eletrônica de Transmissão , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Mitocôndrias/ultraestrutura , Picea/ultraestrutura , Tubo Polínico/metabolismo , Tubo Polínico/ultraestrutura , Inibidores de Proteassoma
11.
Chin Med J (Engl) ; 122(5): 509-13, 2009 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-19323899

RESUMO

BACKGROUND: The lung functional status could be displayed on lung perfusion images. With the images, the radiotherapy plans of lung cancer could be guided to more optimized. This study aimed to assess quantitatively the impact of incorporating functional lung imaging into 3-dimensional conformal radiotherapy (3DCRT) and intensity-modulated radiation therapy (IMRT) planning for non-small cell lung cancer (NSCLC). METHODS: Ten patients with NSCLC who had undergone radiotherapy were included in this study. Before radiotherapy, each patient underwent CT simulation and lung perfusion imaging with single photon emission computed tomography (SPECT). The SPECT images were registered with simulation planning CT and used to contour functional lung (lung-F) and non-functional lung (lung-NF). Two 3DCRT plans and two IMRT plans were designed and compared in each patient: two anatomic plans using simulation CT alone and two functional plans using SPECT-CT in addition to the simulation CT. Dosimetric parameters of the four types of plans were compared in terms of tumor coverage and avoidance of normal tissues. Total radiation dose was set at 66 Gy (2 Gy x 33 fractions). RESULTS: In incorporating perfusion information in 3DCRT and IMRT planning, the reductions on average in the mean doses to the functional lung in the functional plan were 168 cGy and 89 cGy, respectively, compared with those in the anatomic plans. The median reductions in the percentage of volume irradiated with > 5 Gy, > 10 Gy, > 20 Gy, > 30 Gy and > 40 Gy for functional lung in the functional plans were 6.50%, 10.21%, 14.02%, 22.30% and 23.46% in 3DCRT planning, respectively, and 3.05%, 15.52%, 14.16%, 4.87%, and 3.33% in IMRT planning, respectively. No greater degree of sparing of the functional lung was achieved in functional IMRT than in 3DCRT. CONCLUSION: Function-guided 3DCRT and IMRT plannings both appear to be effective in preserving functional lung in NSCLC patients.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/radioterapia , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Carcinoma Pulmonar de Células não Pequenas/diagnóstico por imagem , Humanos , Radiografia , Radioterapia Conformacional/métodos , Radioterapia de Intensidade Modulada/métodos
12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(2): 271-4, 2006 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-16826904

RESUMO

The in vitro dry matter digestion (IVDMD) in maize stalk was analyzed with 161 samples selected from 600 samples of different eco-environments, hybrids and inbred lines, development stages, and various parts of the plants in two years. The technique of near infrared reflectance spectroscopy (NIRS) and partial least square regression (PLS) were used to establish the models by comparing several preprocessing procedures and wavelength ranges. The optimal models could be obtained in the range of 6 101. 7-5 773. 8 cm(-1) and 4 601. 3-4 246. 5 cm(-1) by the spectral data preprocessing of the Max-Min normalization. The model is suitable for measuring various sample IVDMD. The determination coefficients of the modes were 0.907 3 and 0.906 6 for cross and external validation, respectively. The root mean square error of prediction was 2.08%, and the coefficient of correlation(r) was 0.956 between NIRS predicted and actual IVDMD in these materials. The results showed that NIRS is a simple effective means for measuring IVDMD in maize stalk. The results are of great value of application in screening and evaluating quality constituents of silage maize.


Assuntos
Ração Animal/análise , Digestão , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Zea mays/química , Animais , Bovinos , Análise dos Mínimos Quadrados , Masculino , Caules de Planta/química
14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 24(11): 1345-7, 2004 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-15762472

RESUMO

The NDF (Neutral Detergent Fiber) and ADF (Acid Detergent Fiber) concentrations in maize stalk were analyzed with 147 samples selected from 600 samples of different eco-environments, hybrids and inbred lines, development stages, and various parts of the plants in two years. The technique of near infrared reflectance spectroscopy (NIRS) and partial least square (PLS) regression were used to establish the models. The results showed that the calibration models developed by the spectral data pretreatment of the first derivative + vector normalization, and the first derivative + multivariate scattering correction were the best for NDF and ADF with the same spectral regions (7501.7-5449.8 cm(-1) and 4601.3-4246.5 cm(-1)). All these models yielded coefficients of determination of calibration (R2(cal)) for NDF and ADF that are higher than 0.94, while R2(cv) and R2(val) ranged from 0.92 to 0.96 for cross and external validation. The root mean square error of estimation, root mean square error of cross validation, and root mean square error of prediction (RMSEE, RMSECV and RMSEP) for NDF and ADF ranged from 1.49% to 1.81%. The models can be used to measure various samples in screening and evaluating quality constituents of silage maize.


Assuntos
Espectroscopia de Luz Próxima ao Infravermelho/métodos , Zea mays/química , Calibragem , Estudos de Avaliação como Assunto , Zea mays/classificação
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