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排序方式: 共有504条查询结果,搜索用时 31 毫秒
71.
Dr. Ignacio Delso Dr. Jessika Valero‐Gonzalez Dr. Fernando Gomollón‐Bel Jorge Castro‐López Dr. Wenxia Fang Dr. Iva Navratilova Prof. Daan M. F. van Aalten Prof. Tomás Tejero Prof. Pedro Merino Dr. Ramon Hurtado‐Guerrero 《ChemMedChem》2018,13(2):128-132
Fungal β‐1,3‐glucan glucanosyltransferases are glucan‐remodeling enzymes that play important roles in cell wall integrity, and are essential for the viability of pathogenic fungi and yeasts. As such, they are considered possible drug targets, although inhibitors of this class of enzymes have not yet been reported. Herein we report a multidisciplinary approach based on a structure‐guided design using a highly conserved transglycosylase from Sacharomyces cerevisiae, that leads to carbohydrate derivatives with high affinity for Aspergillus fumigatus Gel4. We demonstrate by X‐ray crystallography that the compounds bind in the active site of Gas2/Gel4 and interact with the catalytic machinery. The topological analysis of noncovalent interactions demonstrates that the combination of a triazole with positively charged aromatic moieties are important for optimal interactions with Gas2/Gel4 through unusual pyridinium cation–π and face‐to‐face π–π interactions. The lead compound is capable of inhibiting AfGel4 with an IC50 value of 42 μm . 相似文献
72.
Díaz B Sánchez-Espinel C Arruebo M Faro J de Miguel E Magadán S Yagüe C Fernández-Pacheco R Ibarra MR Santamaría J González-Fernández A 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(11):2025-2034
Inorganic nanoparticles (NPs) show great potential for medicinal therapy. However, biocompatibility studies are essential to determine if they are safe. Here, five different NPs are compared for their cytotoxicity, internalization, aggregation in medium, and reactive oxygen species (ROS) production, using tumoral and normal human blood cells. Differences depending on the cell type are analyzed, and no direct correlation between ROS production and cell toxicity is found. Results are discussed with the aim of standardizing the procedures for the evaluation of the toxicity. 相似文献
73.
Ballesteros B Tobias G Shao L Pellicer E Nogués J Mendoza E Green ML 《Small (Weinheim an der Bergstrasse, Germany)》2008,4(9):1501-1506
Purification and shortening of single-walled carbon nanotubes (SWNTs) is carried out by treatment with steam. During the steam purification the graphitic shells coating the catalytic metal particles are removed. Consequently, the exposed catalytic particles can be easily dissolved by treatment with hydrochloric acid. No damage to the carbon nanotube tubular structure is observed, even after prolonged treatment with steam. Samples are characterized by HRTEM, TGA, magnetic measurements, Raman spectroscopy, AFM, and XPS. 相似文献
74.
Tunable Nanoparticle and Cell Assembly Using Combined Self‐Powered Microfluidics and Microcontact Printing 下载免费PDF全文
Cyrille Hamon Malou Henriksen‐Lacey Andrea La Porta Melania Rosique Judith Langer Leonardo Scarabelli Ana Belén Serrano Montes Guillermo González‐Rubio Marian M. de Pancorbo Luis M. Liz‐Marzán Lourdes Basabe‐Desmonts 《Advanced functional materials》2016,26(44):8053-8061
The combination of cell microenvironment control and real‐time monitoring of cell signaling events can provide key biological information. Through precise multipatterning of gold nanoparticles (GNPs) around cells, sensing and actuating elements can be introduced in the cells' microenviroment, providing a powerful substrate for cell studies. In this work, a combination of techniques are implemented to engineer complex substrates for cell studies. Alternating GNPs and bioactive areas are created with micrometer separation by means of a combination of vacumm soft‐lithography of GNPs and protein microcontract printing. Instead of conventional microfluidics that need syringe pumps to flow liquid in the microchannels, degas driven flow is used to fill dead‐end channels with GNP solutions, rendering the fabrication process straightforward and accessible. This new combined technique is called Printing and Vacuum lithography (PnV lithography). By using different GNPs with various organic coating ligands, different macroscale patterns are obtained, such as wires, supercrystals, and uniformly spread nanoparticle layers that can find different applications depending on the need of the user. The application of the system is tested to pattern a range of mammalian cell lines and obtain readouts on cell viability, cell morphology, and the presence of cell adhesive proteins. 相似文献
75.
Hongrui Liu Patrick Da Costa Haithem Bel Hadj Taief Mourad Benzina Maria Elena Gálvez 《International Journal of Hydrogen Energy》2017,42(37):23508-23516
Ce and Zr promoted Fe/Cu-modified natural clay based catalysts were prepared and tested in dry reforming of methane (DRM) at temperatures from 600 to 800 °C. The physicochemical properties of these catalysts were analyzed by means of N2 adsorption, X-ray diffraction (XRD). H2-temperature programmed reduction (H2-TPR) and CO2-temperature programmed desorption (TPD). Ce and Zr promotion resulted in a considerable increase of the catalytic activity. This increase can be mainly ascribed to an improved reducibility of Ni species, together with slightly higher Ni0 crystal size, that, on the other hand, also catalyze undesired parallel reactions resulting in carbon formation, such as direct methane decomposition. Both Ce and Zr presence also promoted the presence of weak and medium strength basic sites, which are thought to favor CO2 adsorption and desorption on the catalyst surface, leading to enhanced catalytic activity. 相似文献
76.
Sarah Bel Thomas Struyf Tine Fierens Griet Jacobs Christine Vinkx Mia Bellemans 《Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment》2018,35(5):828-837
A dietary exposure assessment of food emulsifiers E481 (sodium stearoyl-2-lactylate) and E482 (calcium stearoyl-2-lactylate) in the Belgian population was performed. Nationally representative food consumption data from the Belgian National Food Consumption Surveys 2004 (BNFCS2004) and 2014 (BNFCS2014) were used for calculations. A conservative approach (combining individual food consumption data with the maximum permitted level (MPL) of foods (tier 2), was compared with more refined estimates (combining individual food consumption data with actual concentrations measured in food products available on the Belgian market (tier 3)). Estimated daily intakes were compared to the acceptable daily intake (ADI) of the stearoyl-2-lactylates. The results of tier 2 demonstrated that 92% of the children (3–9 years), 53% of the adolescents (10–17 years), 15% of the adults (18–64 years) and 26% of the elderly (64–98 years) had a potential intake higher than the ADI. When replacing the MPL with maximum analysed concentration levels in foods, daily intake estimates decreased dramatically. The estimated daily intake of the food emulsifiers was below the ADI for all age groups, except for a small percentage of children (1.9%) for which the intake exceeded the ADI. The main contributors to the exposure of E481 and E482 were bread, rolls and fine bakery wares. 相似文献
77.
Franzoni MB Acosta RH Pastawski HM Levstein PR 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2012,370(1976):4713-4733
Nuclear spins are promising candidates for quantum information processing because their good isolation from the environment precludes the rapid loss of quantum coherence. Many strategies have been developed to further extend their decoherence times. Some of them make use of decoupling techniques based on the Carr-Purcell and Carr-Purcell-Meiboom-Gill pulse sequences. In many cases, when applied to inhomogeneous samples, they yield a magnetization decay much slower than that of the Hahn echo. However, we have proved that these decays cannot be associated with longer decoherence times, as coherences remain frozen. They result from coherences recovered after their storage as local polarization and thus they can be used as memories. We show here how this freezing of the coherent state, which can subsequently be recovered after times longer than the natural decoherence time of the system, can be generated in a controlled way with the use of field gradients. A similar behaviour of homogeneous samples in inhomogeneous fields is demonstrated. It is emphasized that the effects of inhomogeneities in solid-state nuclear magnetic resonance, independently of their origin, should not be disregarded, as they play a crucial role in multipulse sequences. 相似文献
78.
Fruit flesh volatile and carotenoid profile analysis within the Cucumis melo L. species reveals unexploited variability for future genetic breeding 下载免费PDF全文
79.
Evaluation of postharvest calcium treatment and biopreservation with Lactobacillus rhamnosus GG on the quality of fresh‐cut ‘Conference’ pears 下载免费PDF全文
80.
The present investigation involves a unique, 7 year (2001–2007) long study of corrosion and deposits on superheater tubes in a biomass fired circulated fluidized bed boiler. These measurements are correlated against the different fuels used over this period. In the earlier years, the boiler was run with a mixture of different biomass fuels and peat. In later years, recycled wood was introduced into the fuel mix. The deposit growth rate approximately doubled when the recycled wood content of the fuel was increased to 10–20%. Small amounts of chlorine and zinc were found both in the recycled wood and in the deposit layer. These elements together with alkali metals from the biomass, have the potential to form sticky compounds that increase the deposit growth rate. The corrosion rate of the superheater tubes varied over the study period. A number of possible explanations for this phenomenon are discussed. 相似文献