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排序方式: 共有2933条查询结果,搜索用时 31 毫秒
1.
Lipase production by solid‐state fermentation of olive pomace in tray‐type and pressurized bioreactors 下载免费PDF全文
2.
André Campaniço Dr. Marta P. Carrasco Dr. Mathew Njoroge Ronnett Seldon Prof. Kelly Chibale Dr. João Perdigão Prof. Isabel Portugal Prof. Digby F. Warner Prof. Rui Moreira Prof. Francisca Lopes 《ChemMedChem》2019,14(16):1537-1546
Herein we report the screening of a small library of aurones and their isosteric counterparts, azaaurones and N-acetylazaaurones, against Mycobacterium tuberculosis. Aurones were found to be inactive at 20 μm , whereas azaaurones and N-acetylazaaurones emerged as the most potent compounds, with nine derivatives displaying MIC99 values ranging from 0.4 to 2.0 μm . In addition, several N-acetylazaaurones were found to be active against multidrug-resistant (MDR) and extensively drug-resistant (XDR) clinical M. tuberculosis isolates. The antimycobacterial mechanism of action of these compounds remains to be determined; however, a preliminary mechanistic study confirmed that they do not inhibit the mycobacterial cytochrome bc1 complex. Additionally, microsomal metabolic stability and metabolite identification studies revealed that N-acetylazaaurones are deacetylated to their azaaurone counterparts. Overall, these results demonstrate that azaaurones and their N-acetyl counterparts represent a new entry in the toolbox of chemotypes capable of inhibiting M. tuberculosis growth. 相似文献
3.
Diogo Mendes David Sousa Ana C. Cerdeira Laura C.J. Pereira Ana Marques João Murta-Pina Anabela Pronto Isabel Ferreira 《Ceramics International》2021,47(1):381-387
High-performance YBCO 123 (YBa2Cu3O7-x) bulk superconductor samples were produced using the 3D printing paste-extrusion technique. The YBCO powder obtained after sintering a pre-mixture of Y2O3, BaCO3 and CuO powders at 950 °C was used in the formulation of pastes for extrusion in a 3D freeform printer. The 3D samples printed from pastes containing the pre-mixture powders were sintered, while those produced using the YBCO powder were not. X-ray diffraction (XRD), energy dispersive spectroscopy (EDS) and Raman analysis all confirmed the YBCO phase after sintering, both in the powder and in the samples made with the pre-mixture. Scanning electron microscopy (SEM) images revealed powder grains of heterogeneous size and geometry, as well as grain aggregation, in the sintered samples. Superconducting quantum interference device (SQUID) measurements taken within a fixed magnetic range revealed that the printed pieces have a typical magnetization temperature of 92 K, reaching ?1.43 emu/g and ?1.59 emu/g respectively a zero-field-cooled magnetization (ZFC) for sintered and non-sintered printed samples. 相似文献
4.
Maria Quitrio Sandra Simes Andreia Ascenso Manuela Carvalheiro Ana Paula Leandro Isabel Correia Ana Silveira Viana Pedro Faísca Lia Ascenso Jesús Molpeceres Maria Manuela Gaspar Catarina Pinto Reis 《International journal of molecular sciences》2021,22(8)
Insulin is a peptide hormone with many physiological functions, besides its use in diabetes treatment. An important role of insulin is related to the wound healing process—however, insulin itself is too sensitive to the external environment requiring the protective of a nanocarrier. Polymer-based nanoparticles can protect, deliver, and retain the protein in the target area. This study aims to produce and characterize a topical treatment for wound healing consisting of insulin-loaded poly-DL-lactide/glycolide (PLGA) nanoparticles. Insulin-loaded nanoparticles present a mean size of approximately 500 nm and neutral surface charge. Spherical shaped nanoparticles are observed by scanning electron microscopy and confirmed by atomic force microscopy. SDS-PAGE and circular dichroism analysis demonstrated that insulin preserved its integrity and secondary structure after the encapsulation process. In vitro release studies suggested a controlled release profile. Safety of the formulation was confirmed using cell lines, and cell viability was concentration and time-dependent. Preliminary safety in vivo assays also revealed promising results. 相似文献
5.
6.
Biological nitrification in the presence of sulfide and organic matter: effect of zeolite on the process in a batch system 下载免费PDF全文
7.
Chitosan microspheres containing bromocresol green, cresol red, and phenolphthalein for corrosion detection, through pH change, are synthesized in order to be used in protective coatings for aluminium alloys. Microspheres containing corrosion detection species are characterized morphologically (SEM) and physico‐chemically (FTIR, TGA). Release studies (UV–vis) are performed in corrosion‐promoting conditions (pH, NaCl), and detection studies by immersion in media associated with corrosion activity while microspheres' sensing activity is evaluated visually. Electrochemical characterization of AA2024 substrates in the presence of chitosan spheres is performed to understand material performance, and a color change is observed as a result of local pH increase in cathodic areas when corrosion takes place. These findings can be correlated with the results from release studies and seem a promising approach for corrosion sensing purposes, not only because pH increase is possible to detect due to corrosion, but also because chitosan is considered an environmentally friendly material. 相似文献
8.
Isabel Fernandes Cecília Melo-Alvim Raquel Lopes-Brs Miguel Esperana-Martins Luís Costa 《International journal of molecular sciences》2021,22(2)
Osteosarcoma (OS) is a rare condition with very poor prognosis in a metastatic setting. Basic research has enabled a better understanding of OS pathogenesis and the discovery of new potential therapeutic targets. Phase I and II clinical trials are already ongoing, with some promising results for these patients. This article reviews OS pathogenesis and new potential therapeutic targets. 相似文献
9.
Research of polynaphthalimides (PNI) frequently reports difficulties over synthesis and processing due to insolubility. In this work, we present a novel comprehensive study on the effects of time, temperature and catalyst on the synthesis of soluble PNI precursors—polyamic acids (PAAs)—, as well as a novel synthetic procedure for the synthesis of PNI using mild conditions. Kinetic studies concerning the monomer conversion and the degree of premature imidization were performed through proton nuclear magnetic resonance and gel permeation chromatography for temperature ranging from 25 to 100°C. High temperatures (above 60°C) entail extensive premature imidization and insolubility. The use of triethylamine also catalyzes imidization. At the optimal condition, soluble PAA precursors for PNI of 72 kDa could be obtained at 40°C in N-methyl-2-pyrrolidone solution (30 wt%) after 5 hr polymerization. 相似文献
10.
Microbial Fuel Cell Application for Azoic Dye Decolorization with Simultaneous Bioenergy Production Using Stenotrophomonas sp. 下载免费PDF全文
Said Galai Antonia Pérez de los Ríos Francisco José Hernández‐Fernández Sihem Haj Kacem Francisco Mateo Ramírez Joaquín Quesada‐Medina 《化学工程与技术》2015,38(9):1511-1518
A single‐chamber air‐cathode microbial fuel cell (MFC) was successfully applied for decolorization of the diazoic dye Reactive Black 5 (RB5) with simultaneous production of electricity. An innovative low‐cost medium, the marine water‐glucose‐yeast extract medium (MWGY), was developed which appears as a textile marine effluent in terms of salinity. The anode compartment containing a single bacterial strain of Stenotrophomonas sp. showed almost complete dye decolorization with different RB5 concentrations after seven days of treatment. For the four dye concentrations used, a correlation between dye removal and production of electrical energy was found. The comparison of the decolorization process in the MFC with that in a batch reactor as control experiment highlights the efficiency of the single‐chamber air‐cathode MFC technology which improved the dye removal by the same bacterial strain. 相似文献