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排序方式: 共有2647条查询结果,搜索用时 17 毫秒
1.
Rafael Salomão Mirian A. Kawamura Ana B.V. Emilio José Sakihama Ana M. Segadães 《Ceramics International》2021,47(11):15082-15093
Calcium hexaluminate (CA6) is an intrinsically densification-resistant material, therefore, its porous structures are key materials for applications as high-temperature thermal insulators. This article reports on the combination of calcined alumina and calcium aluminate cement (CAC) in castable aqueous suspensions for the in situ production of porous CA6. The CAC content (10–34 vol%) and the curing conditions ensure structural integrity prior to sintering and maximize the development of hydrated phases. Changes in physical properties, crystalline phases, and microstructure were investigated after isothermal treatments (120–1500 °C), and three sequential porogenic events were observed. The hydration of CAC preserved the water-derived pores (up to 120 °C), and the dehydroxylation of CAC hydrates (250–700 °C) generated inter-particles pores. Moreover, the in situ expansive formation of CA2 and CA6 (900–1500 °C) hindered densification and generated intra-particle pores. Such events differed from those observed with other CaO sources, and resulted in significantly higher pores content and lower thermal conductivity. 相似文献
2.
Dr. Walter D. Guerra Dr. Daniel Lucena-Agell Rafael Hortigüela Prof. Roberto A. Rossi Dr. J. Fernando Díaz Prof. José M. Padrón Dr. Silvia M. Barolo 《ChemMedChem》2021,16(19):3003-3016
We prepared a series of free NH and N-substituted dibenzonthiazines with potential anti-tumor activity from N-aryl-benzenesulfonamides. A biological test of synthesized compounds (59 samples) was performed in vitro measuring their antiproliferative activity against a panel of six human solid tumor cell lines and its tubulin inhibitory activity. We identified 6-(phenylsulfonyl)-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide and 6-tosyl-6H-dibenzo[c,e][1,2]thiazine 5,5-dioxide as the best compounds with promising values of activity (overall range of 2–5.4 μM). Herein, we report the dibenzothiazine core as a novel building block with antiproliferative activity, targeting tubulin dynamics. 相似文献
3.
Myriam Gonzlez María Ovejero-Snchez Alba Vicente-Blzquez Raquel lvarez Ana B. Herrero Manuel Medarde Rogelio Gonzlez-Sarmiento Rafael Pelez 《International journal of molecular sciences》2021,22(4)
Pan-Gyn cancers entail 1 in 5 cancer cases worldwide, breast cancer being the most commonly diagnosed and responsible for most cancer deaths in women. The high incidence and mortality of these malignancies, together with the handicaps of taxanes—first-line treatments—turn the development of alternative therapeutics into an urgency. Taxanes exhibit low water solubility that require formulations that involve side effects. These drugs are often associated with dose-limiting toxicities and with the appearance of multi-drug resistance (MDR). Here, we propose targeting tubulin with compounds directed to the colchicine site, as their smaller size offer pharmacokinetic advantages and make them less prone to MDR efflux. We have prepared 52 new Microtubule Destabilizing Sulfonamides (MDS) that mostly avoid MDR-mediated resistance and with improved aqueous solubility. The most potent compounds, N-methyl-N-(3,4,5-trimethoxyphenyl-4-methylaminobenzenesulfonamide 38, N-methyl-N-(3,4,5-trimethoxyphenyl-4-methoxy-3-aminobenzenesulfonamide 42, and N-benzyl-N-(3,4,5-trimethoxyphenyl-4-methoxy-3-aminobenzenesulfonamide 45 show nanomolar antiproliferative potencies against ovarian, breast, and cervix carcinoma cells, similar or even better than paclitaxel. Compounds behave as tubulin-binding agents, causing an evident disruption of the microtubule network, in vitro Tubulin Polymerization Inhibition (TPI), and mitotic catastrophe followed by apoptosis. Our results suggest that these novel MDS may be promising alternatives to taxane-based chemotherapy in chemoresistant Pan-Gyn cancers. 相似文献
4.
Camila C. Lopes Wagner A. Pinheiro Daniel Navarro da Rocha José G. Neves Américo Bortolazzo Correr José R.M. Ferreira Rafael M. Barbosa Jefferson R.F. Soares Jheison L. Santos Marcelo H. Prado da Silva 《Ceramics International》2021,47(6):7653-7665
The repair of bone fractures is a clinical challenge for patients with impaired healing, such as osteoporosis. Currently, different strategies have been developed to design new biomaterials, enhancing their interactions with biological systems and conducting the cellular behavior in the desired direction to help fracture healing. In the present work, hydroxyapatite-graphene oxide (HA-GO) nanocomposites were produced and the morphological and physicochemical influences of the addition of 0.5 wt%, 1.0 wt% and 1.5 wt% of GO to HA were observed. FEG-SEM and TEM analyses of HA-GO nanocomposites showed HA nanoparticles adhered to the surface of the GO sheets, suggesting an effective method to form nanostructured graphene-based biomaterials. As confirmation, physicochemical analyses by Raman, FTIR and TGA demonstrated a strong affinity between HA and GO, according to the increase of concentration from 0.5 wt% to 1.5 wt% GO in the HA-GO nanocomposites. Also, in order to evaluate the HA-GO nanocomposites behavior under biological microenvironment, in vitro bioactivity and indirect cytotoxicity tests were performed. FEG-SEM analyses confirmed the positive results for the bioactivity properties of HA-GO nanocomposite and indirect cytotoxicity demonstrated that even with a decrease in the hDPSCs viability and proliferation, when increasing to 1.5 wt% of GO concentration, high level of cell viability was exhibited by HA-GO nanocomposites. These biological results suggested the 0.5 wt% HA-GO nanocomposite as a potential bioactive bone graft and a promising biomaterial for bone tissue regeneration, when compared to the pure HA. 相似文献
5.
Pedro Gama Dr. Ruben D. Cadena-Nava Dr. Karla Juarez-Moreno Dr. Javier Pérez-Robles Prof. Rafael Vazquez-Duhalt 《ChemMedChem》2021,16(9):1438-1445
Enzymatic nanoreactors were obtained by galactose-1-phosphate uridylyl-transferase (GALT) encapsulation into plant virus capsids by a molecular self-assembly strategy. The aim of this work was to produce virus-like nanoparticles containing GALT for an enzyme-replacement therapy for classic galactosemia. The encapsulation efficiency and the catalytic constants of bio-nanoreactors were determined by using different GALT and virus coat protein ratios. The substrate affinity of nanoreactors was slightly lower than that of the free enzyme; the activity rate was 16 % of the GALT free enzyme. The enzymatic nanoreactors without functionalization were internalized into different cell lines including fibroblast and kidney cells, but especially into hepatocytes. The enzymatic nanoreactors are an innovative enzyme preparation with potential use for the treatment of classic galactosemia. 相似文献
6.
Rafael Bernardo Carmona-Paredes Rafael Bernardo Carmona-Benítez 《Water Resources Management》2018,32(5):1651-1673
The rapid population growth of cities in developing countries (DC) make difficult to distribute the available potable water (PW) with equality. The distribution problem arises from an insufficient amount of PW and because cities water distribution systems (WDS) are not efficient. The novelty of this paper is a self-tuning controller (STC) proposed to manage, along the day, the pressure of water through the nodes of a WDS. It means, pressure management (PM) is proposed to control water levels (WLs) in householders tanks (HTs). The objective is to satisfy with equality the PW demand at different zones of a city forcing the flow of water by managing the pressure. The proposed STC performance is tested on the digital simulator developed to characterize the hydraulic operation of a WDS. The dynamic behaviour of the WDS is determined by the variation of the WL in the tanks of the WDS when water is supplied or extracted from them. The WDS of Mexico City is analysed and the proposed STC is applied to a simplified WDS. The results allow to conclude that the proposed STC could become a supporting tool for the decision making of WDS operators. 相似文献
7.
Rafael Raphaela Azevedo Noronha Fábio Bellot Gaspar Alexandre Barros 《Topics in Catalysis》2020,63(11-14):1066-1076
Topics in Catalysis - This work investigated the photodegradation of bromophenol blue (BPB) and indigo carmine (IC) dye under UV–Visible light using pure oxides of titanium and niobium, as... 相似文献
8.
Pablo Ares Tommaso Cea Matthew Holwill Yi Bo Wang Rafael Roldán Francisco Guinea Daria V. Andreeva Laura Fumagalli Konstantin S. Novoselov Colin R. Woods 《Advanced materials (Deerfield Beach, Fla.)》2020,32(1):1905504
2D hexagonal boron nitride (hBN) is a wide-bandgap van der Waals crystal with a unique combination of properties, including exceptional strength, large oxidation resistance at high temperatures, and optical functionalities. Furthermore, in recent years hBN crystals have become the material of choice for encapsulating other 2D crystals in a variety of technological applications, from optoelectronic and tunneling devices to composites. Monolayer hBN, which has no center of symmetry, is predicted to exhibit piezoelectric properties, yet experimental evidence is lacking. Here, by using electrostatic force microscopy, this effect is observed as a strain-induced change in the local electric field around bubbles and creases, in agreement with theoretical calculations. No piezoelectricity is found in bilayer and bulk hBN, where the center of symmetry is restored. These results add piezoelectricity to the known properties of monolayer hBN, which makes it a desirable candidate for novel electromechanical and stretchable optoelectronic devices, and pave a way to control the local electric field and carrier concentration in van der Waals heterostructures via strain. The experimental approach used here also shows a way to investigate the piezoelectric properties of other materials on the nanoscale by using electrostatic scanning probe techniques. 相似文献
9.
Ricardo Cambraia Parreira Diana Paola Gmez‐Mendoza Itamar Couto Guedes de Jesus Rafael Pereira Lemos Anderson Kennedy Santos Cristiana Perdigo Rezende Henrique Csar Pereira Figueiredo Mauro Cunha Xavier Pinto Frank Kjeldsen Silvia Guatimosim Rodrigo Ribeiro Resende Thiago Verano‐Braga 《Proteomics. Clinical applications》2020,14(4)