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1.
PLoS One ; 16(10): e0254542, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34648508

RESUMO

The purposes are to solve the isomorphism encountered while processing hyperspectral remote sensing data and improve the accuracy of hyperspectral remote sensing data in extracting and classifying lithological information. Taking rocks as the research object, Backpropagation Neural Network (BPNN) is introduced. After the hyperspectral image data are normalized, the lithological spectrum and spatial information are the feature extraction targets to construct a deep learning-based lithological information extraction model. The performance of the model is analyzed using specific instance data. Results demonstrate that the overall accuracy and the Kappa coefficient of the lithological information extraction and classification model based on deep learning were 90.58% and 0.8676, respectively. This model can precisely distinguish the properties of rock masses and provide better performance compared with the state of other analysis models. After introducing deep learning, the recognition accuracy and the Kappa coefficient of the proposed BPNN model increased by 8.5% and 0.12, respectively, compared with the traditional BPNN. The proposed extraction and classification model can provide some research values and practical significances for the hyperspectral rock and mineral classification.

2.
Talanta ; 235: 122818, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517674

RESUMO

As a type of environmental endocrine disrupting chemicals, bisphenols (BPs) have a certain embryonic toxicity and teratogenicity, which can significantly increase the risks of breast cancer, prostate cancer, leukemia and other cancers. In this work, stable multivariate metal-organic frameworks (UiO-66-NH2/TCPPx) were synthesized via in situ one-pot method and used as miniaturized dispersive solid-phase extraction (dµSPE) sorbents for extraction of trace BPs from environmental samples. The phase purity, crystal morphology and physical properties of UiO-66-NH2/TCPPx samples were varied by adjusting the mass ratio of TCPP. The extraction performance of UiO-66-NH2/TCPPx samples were investigated and UiO-66-NH2/TCPP1.0 exhibited the highest adsorption efficiency. Besides, UiO-66-NH2/TCPP1.0 possessed excellent recycling stability for the adsorption and desorption of BPs more than 20 cycles. The experimental parameters including amount of adsorbent, adsorption time, sample solution pH, temperature, desorption time and desorption solvents which affecting the efficiency of dµSPE were studied, respectively. Good linearity (R2 > 0.9992) in range of 0.1-200 ng mL-1 was obtained. The detection limits (S/N = 3) and quantification limits (S/N = 10) were achieved at 0.03-0.08 ng mL-1 and 0.1-0.5 ng mL-1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day ranged from 2.5 to 5.5% and 1.1-6.8%. Enrichment factors were calculated in the range of 303-338. The obtained recoveries of bisphenol F (BPF), bisphenol A (BPA), bisphenol B (BPB) and bisphenol AF (BPAF) were 81.26-91.03% (RSDs = 0.96-6.47%), 82.2-97.27% (RSDs = 0.45-6.15%), 87.56-97.26% (RSDs = 1.1-6.22%) and 82.2-100.8% (RSDs = 0.46-4.07%). The UiO-66-NH2/TCPP1.0 can be employed as potential dµSPE sorbents for the enrichment of trace BPs in the environmental samples.


Assuntos
Estruturas Metalorgânicas , Adsorção , Compostos Benzidrílicos , Humanos , Masculino , Fenóis , Extração em Fase Sólida , Solventes
3.
Bioresour Technol ; 318: 124257, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33096442

RESUMO

2-Phenylethanol (2-PE) is an important high-grade aromatic alcohol, which is widely used in the cosmetics, perfumery and food industries. However, 2-PE is mainly synthesized using a chemical route, which produces environmental pollution and harmful by-products. Screening of high-yielding wild-type strains has become an important goal for the future biosynthesis of 2-PE. In this study, a wild-type Wickerhamomyces anomalus was isolated from rice wine fermented mash. By optimizing the initial glucose and l-phenylalanine concentrations, 2630.7 mg/L of 2-PE was obtained in shaking flasks. The conditions of initial glucose and l-phenylalanine concentration, pH, and inoculation amount were optimized for 2-PE production with W. anomalus. Finally, based on the optimal conditions, the 2-PE titer reached 4,727.3 mg/L by a single-dose fed-batch strategy in a 5-L bioreactor. The results showed that the ability was expanded to harness the Ehrlich pathway for the production of high-value aromatics in aroma-producing yeast species.


Assuntos
Álcool Feniletílico , Vinho , Candida , Fermentação , Saccharomyces cerevisiae
4.
J Chromatogr A ; 1626: 461354, 2020 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-32797834

RESUMO

The Al-doped mesoporous crystalline material-41 (Al-MCM-41) composite was prepared and applied as fiber coating material of headspace solid-phase microextraction (HS-SPME) for extraction of polycyclic aromatic hydrocarbons (PAHs) from human urine. Five PAHs including acenaphthene, fluorene, phenanthrene, anthracene, and pyrene are chosen as target analytes to evaluate the performance of the material by GC-FID analysis. The mesoporous Al-MCM-41 composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption/desorption measurement, and thermogravimetric analysis. The parameters affecting the extraction efficiency of HS-SPME were investigated. Under the optimal conditions, the method exhibits ideal linearity for target analytes in the range of 0.3-600 ng⋅mL-1 with the coefficients (R2) equal or higher than 0.9906. The enrichment factors are calculated from 540 to 1760. The limits of detection (LODs) and limits of quantitation (LOQs) are between the ranges of 0.06-0.18 and 0.3-0.9 ng⋅mL-1, respectively. The relative standard deviations (RSDs) (n = 5) of intra-day and inter-day are in the ranges of 1.08-7.49% and 2.84-18.3% respectively. The fiber-to-fiber reproducibility (n = 3) is in the range of 6.47-13.9%. The method was successfully applied for the analysis of PAHs in human urine with reasonable recoveries which is ranging from 73.29 to 116.1%.


Assuntos
Alumínio/química , Hidrocarbonetos Policíclicos Aromáticos/urina , Dióxido de Silício/química , Microextração em Fase Sólida/métodos , Adsorção , Cristalização , Humanos , Limite de Detecção , Masculino , Concentração Osmolar , Porosidade , Padrões de Referência , Reprodutibilidade dos Testes , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Difração de Raios X
5.
J Nanosci Nanotechnol ; 18(12): 8296-8301, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30189950

RESUMO

Special morphological noble metal-based bimetallic alloy nanostructures became popular for methanol oxidation reaction in order to reduce the high cost of the Pt catalyst and improve the catalyst activity. Herein, we developed a facile one pot hydrothermal method for the synthesis of platinum-copper bimetallic nanoflowers (Pt-Cu NFs) in the presence of hexadecyl trimethyl ammonium bromide (CTAB). The morphology, structure and composition of Pt-Cu NFs were carefully characterized and the synthesized parameters were optimized systematically by adjusting different experimental conditions. Results showed that the CTAB usage and the NaI amount were critical to the controlled synthesis of Pt-Cu NFs. The Pt-Cu NFs were high-performance electrocatalysts for the methanol oxidation reaction (MOR) with superior activity and superior stability in alkaline solution, which were far better than pure Pt nanoparticle electrocatalysts.

6.
J Biosci Bioeng ; 125(1): 23-29, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28743658

RESUMO

In this study, the coding sequence of the lipase from Proteus sp. SW1 was optimized via codon optimization and subjected to expression in Pichia pastoris GS115. The maximum enzyme yield was 387 mg/L in the supernatants of the shake-flask culture. The purified recombinant lipase exhibited a specific activity of 130 U/mg toward p-nitrophenyl Laurate. Its optimum pH and temperature were 8.0 and 40°C, respectively. It was highly stable and even activated in water-miscible solvents, showing over 102% residual activity after 24 h incubation in ethanol, acetone, isopropanol and acetonitrile. In addition, the enzyme showed promoted activity with the increasing concentrations of methanol/ethanol and exhibited the maximum activity at 80%. In a solvent-free system for biodiesel synthesis with a one-step addition of methanol, the recombinant lipase displayed a 87% conversion rate toward palm oil at the high water content of 80%. The highly improved expression level and activity of the recombinant lipase may contribute to enable its commercial-scale production, and the unique properties would make it a particularly promising biocatalyst for biodiesel production in the future.


Assuntos
Lipase/genética , Lipase/metabolismo , Pichia/genética , Solventes/farmacologia , 2-Propanol/farmacologia , Acetona/farmacologia , Acetonitrilas/farmacologia , Biocombustíveis/provisão & distribuição , Ativação Enzimática/efeitos dos fármacos , Estabilidade Enzimática/efeitos dos fármacos , Etanol/farmacologia , Concentração de Íons de Hidrogênio , Lauratos/metabolismo , Lipase/biossíntese , Lipase/isolamento & purificação , Metanol/farmacologia , Óleo de Palmeira/metabolismo , Proteus/enzimologia , Temperatura
7.
Nanomaterials (Basel) ; 8(1)2017 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-29295535

RESUMO

In this work, a highly efficient and rapid method for simultaneously removing cationic dyes from aqueous solutions was developed by using monodispersed mesoporous silica nanoparticles (MSNs) as the adsorbents. The MSNs were prepared by a facile one-pot method and characterized by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared spectroscopy, and Brunauer-Emmett-Teller. Experimental results demonstrated that the as-prepared MSNs possessed a large specific surface area (about 585 m²/g), uniform particle size (about 30 nm), large pore volume (1.175 cm³/g), and narrow pore size distribution (1.68 nm). The materials showed highly efficient and rapid adsorption properties for cationic dyes including rhodamine B, methylene blue, methyl violet, malachite green, and basic fuchsin. Under the optimized conditions, the maximum adsorption capacities for the above mentioned cationic dyes were in the range of 14.70 mg/g to 34.23 mg/g, which could be achieved within 2 to 6 min. The probable adsorption mechanism of MSNs for adsorption of cationic dyes is proposed. It could be considered that the adsorption is mainly controlled by electrostatic interactions and hydrogen bonding between the cationic dyes and MSNs. As a low-cost, biocompatible, and environmentally friendly material, MSNs have a potential application in wastewater treatment for removing some environmental cationic contaminants.

8.
PLoS One ; 10(10): e0139775, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26440522

RESUMO

Pea (Pisum sativum L.) is an important food legume globally, and is the plant species that J.G. Mendel used to lay the foundation of modern genetics. However, genomics resources of pea are limited comparing to other crop species. Application of marker assisted selection (MAS) in pea breeding has lagged behind many other crops. Development of a large number of novel and reliable SSR (simple sequence repeat) or microsatellite markers will help both basic and applied genomics research of this crop. The Illumina HiSeq 2500 System was used to uncover 8,899 putative SSR containing sequences, and 3,275 non-redundant primers were designed to amplify these SSRs. Among the 1,644 SSRs that were randomly selected for primer validation, 841 yielded reliable amplifications of detectable polymorphisms among 24 genotypes of cultivated pea (Pisum sativum L.) and wild relatives (P. fulvum Sm.) originated from diverse geographical locations. The dataset indicated that the allele number per locus ranged from 2 to 10, and that the polymorphism information content (PIC) ranged from 0.08 to 0.82 with an average of 0.38. These 1,644 novel SSR markers were also tested for polymorphism between genotypes G0003973 and G0005527. Finally, 33 polymorphic SSR markers were anchored on the genetic linkage map of G0003973 × G0005527 F2 population.


Assuntos
Genoma de Planta , Repetições de Microssatélites , Ervilhas/genética , Polimorfismo Genético , Alelos , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala
9.
J Mater Chem B ; 2(35): 5847-5853, 2014 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32262028

RESUMO

This work reports a simple and sensitive sensing protocol for the quantitative monitoring of telomerase activity based on target-responsive release of cargo from wrapping DNA-capped mesoporous silica nanoparticles (MSNs) by coupling with a portable personal glucometer (PGM). To construct such an assay system, glucose molecules are initially loaded into the pores of the aminated MSN, and the pores are then sealed with a specially designed wrapping DNA. Upon the addition of telomerase and dNTPs, the assembled wrapping DNA strands are prolonged with the assistance of telomerase on the aminated MSN. Accompanying the progression of telomerase, the extended DNA strands detach from the MSN, owing to the formation of rigid, hairpin-like DNA structures. The "molecular gates" are then opened, resulting in the release of glucose from MSN. The released glucose molecules can be quantitatively monitored using an external PGM. The PGM signal increases with the increment of telomerase activity. Under optimal conditions, the PGM-based sensing platform exhibits good analytical properties for the determination of telomerase activity and allows for the detection of telomerase activity in the HeLa extract at concentrations as low as 80 cells mL-1. Using somatic and tumor cell lines, the generality of the assay is evaluated with satisfactory results. The inhibition effect of 3'-azido-3'-deoxythymidine also receives a good performance in the telomerase-inhibitor screening research. The methodology affords good reproducibility and simple operations, thus providing a useful scheme for practical use in a quantitative telomerase activity assay for clinical application.

10.
Ann Vasc Surg ; 24(2): 225-32, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19748211

RESUMO

BACKGROUND: We conducted a randomized controlled study on the neuroprotective effect of a commonly used anesthetic, etomidate, in an ischemia-reperfusion (IR) injury rabbit model. METHODS: We studied 24 white adult Japanese rabbits at the animal facility at the Medical College of Wuhan University. Rabbits were randomly assigned into a sham-operation group (group I), an IR group (group II), and an etomidate-treated IR group (group III). Rabbits in groups II and III were subjected to 45 min of infrarenal aortic cross-clamping to induce spinal cord ischemia, while group I rabbits received the sham operation as a control. Following an initial single-dose intravenous injection at 0.6 mg/kg 10 min before aortic clamping, etomidate was infused intravenously at 3mg/(kg . hr) in group III rabbits until unclamping, while 0.9% saline was given as the control in group II. RESULTS: Changes in neurological function scores, histopathology, electromyography, malondialdehyde levels, superoxide dismutase activities, and the concentrations of Ca(2+), Mg(2+), Cu(2+), and Zn(2+) ions were measured. Compared with the sham-operation group, group II showed significant IR injury-associated changes in all parameters evaluated (p<0.01), whereas these unfavorable changes were significantly reversed in etomidate-treated animals (p<0.05 or p<0.01). No significant differences were observed between group I and group III animals in all parameters. CONCLUSION: Etomidate displayed a potent neuroprotective effect against IR-induced spinal cord injuries. We propose that this effect may be associated with the ability of etomidate to enhance the activities of endogenous antioxidants and maintain the ion balance in IR-affected tissues.


Assuntos
Antioxidantes/farmacologia , Etomidato/farmacologia , Fármacos Neuroprotetores/farmacologia , Traumatismo por Reperfusão/prevenção & controle , Isquemia do Cordão Espinal/tratamento farmacológico , Medula Espinal/irrigação sanguínea , Medula Espinal/efeitos dos fármacos , Anestésicos Intravenosos/farmacologia , Animais , Antioxidantes/administração & dosagem , Aorta/cirurgia , Cálcio/metabolismo , Cobre/metabolismo , Modelos Animais de Doenças , Eletromiografia , Etomidato/administração & dosagem , Feminino , Membro Posterior , Infusões Intravenosas , Injeções Intravenosas , Ligadura , Magnésio/metabolismo , Masculino , Malondialdeído/metabolismo , Músculo Esquelético/inervação , Exame Neurológico , Fármacos Neuroprotetores/administração & dosagem , Coelhos , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Medula Espinal/metabolismo , Medula Espinal/patologia , Medula Espinal/fisiopatologia , Isquemia do Cordão Espinal/complicações , Isquemia do Cordão Espinal/metabolismo , Isquemia do Cordão Espinal/patologia , Isquemia do Cordão Espinal/fisiopatologia , Superóxido Dismutase/metabolismo , Zinco/metabolismo
11.
J Org Chem ; 73(21): 8558-62, 2008 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-18844413

RESUMO

The low-molecular-weight and easily prepared N-thiobenzoyl 1-methyl-histidine methyl ester 3k was utilized to efficiently catalyze the kinetic resolution of racemic secondary alcohols. Comparison of the conformations of amide catalyst 3c and thioamide catalyst 3k was made to understand the origin of the improvement of the enantioselectivity by thioamide modification.


Assuntos
Álcoois/isolamento & purificação , Histidina/análogos & derivados , Tioamidas/química , Álcoois/química , Amidas , Histidina/química , Cinética , Conformação Molecular , Estereoisomerismo
12.
Artigo em Chinês | MEDLINE | ID: mdl-11986749

RESUMO

BACKGROUND: To study the effect of gene amplification and selection system with DHFR plus GS and DHFR or GS gene on the foreign gene expression. METHODS: Using the N-terminal truncated hTPO(T184) gene as target gene, two plasmidsre were constructed: pDC- T184 and pGC-T184 where DHFR and GS gene were used respectively as the selective amplification marker. They were cotransfected into CHO dhfr cells to establish dual gene amplification and selection system of DHFR plus GS gen and respectively transfected to establish single gene amplification and selection system of DHFR or GS gene. Three selective methods in dual selective system to compare expression efficiency of hTPO were designed: the first method (DG) was to use drug pressure of MTX, then use MSX; the second method (GD) was reversed; the third method was simultaneously to use MTX and MSX as drug pressure. RESULTS: DHFR+GS dual system had not only higher gene amplification efficiency but also higher level expression. There was no distinct affect in different method of drug pressure. CONCLUSIONS: MTX plus MSX dual drug pressure in dual selection system was an efficient and simple method to increase the expression of foreign gene in mammalian cells.


Assuntos
Amplificação de Genes , Glutamato-Amônia Ligase/genética , Tetra-Hidrofolato Desidrogenase/genética , Animais , Células CHO , Cricetinae , Amplificação de Genes/efeitos dos fármacos , Expressão Gênica , Metotrexato/farmacologia , Plasmídeos/genética
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