排序方式: 共有36条查询结果,搜索用时 31 毫秒
1.
One of the main directions of research for ecologists studying the Earth as a global system is the search for quantitative methods for mapping and monitoring broad-scale patterns of net primary productivity (NPP). While all monitoring activities have a spatial context to a varying degree, the monitoring of NPP patterns requires an objective, criterion-based method for characterizing the spatial distribution of areas that are high or low in NPP relative to their surroundings. In this Letter, we apply a topology-based methodology called the 'echelon approach' to characterize the spatial structure of the remotely sensed NPP spatial structure across the island of Corsica (France) using a coarse-grained grid consisting of annually integrated Normalized Difference Vegetation Index (NDVI) values. Results show that the echelon approach provides a new perspective to objectively characterize the structural complexity of a tessellated surface variable for environmental monitoring purposes. 相似文献
2.
Spray drying of a phenolic‐rich membrane filtration fraction of olive mill wastewater: optimisation and dried product quality
下载免费PDF全文
![点击此处可从《International Journal of Food Science & Technology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Ivana Sedej Rebecca Milczarek Selina C. Wang Runqi Sheng Roberto de Jesús Avena‐Bustillos Lan Dao Gary Takeoka 《International Journal of Food Science & Technology》2016,51(8):1900-1909
Olive mill wastewater (OMWW) from 3‐ and 2‐phase mills was subjected to a two‐step membrane filtration process. The obtained reverse osmosis retentate (RO‐R) is a phenolic‐rich coproduct stream, and the reverse osmosis permeate is a near‐pure water stream. A pilot‐scale spray dryer was used for the production of RO‐R powder. The optimum temperature/feed pump conditions were obtained for 3‐phase (150°C/4.4 Hz) and for 2‐phase RO‐R (175°C/3.8 Hz). The powders obtained by spray drying under these conditions were analysed for physicochemical properties, including identification and quantification of phenolic compounds. Protocatechuic acid, 3‐hydroxytyrosol, tyrosol, vanillic acid and p‐coumaric acid were quantified in both RO‐R powders, which show the possibility to obtain a phenolic‐rich powder from an OMWW filtration fraction. This will lead towards better usage of by‐products from olive oil production. 相似文献
3.
Adele Chimento Anna Santarsiero Domenico Iacopetta Jessica Ceramella Arianna De Luca Vittoria Infantino Ortensia Ilaria Parisi Paola Avena Maria Grazia Bonomo Carmela Saturnino Maria Stefania Sinicropi Vincenzo Pezzi 《International journal of molecular sciences》2021,22(10)
Resveratrol (RSV) is a natural compound that displays several pharmacological properties, including anti-cancer actions. However, its clinical application is limited because of its low solubility and bioavailability. Here, the antiproliferative and anti-inflammatory activity of a series of phenylacetamide RSV derivatives has been evaluated in several cancer cell lines. These derivatives contain a monosubstituted aromatic ring that could mimic the RSV phenolic nucleus and a longer flexible chain that could confer a better stability and bioavailability than RSV. Using MTT assay, we demonstrated that most derivatives exerted antiproliferative effects in almost all of the cancer cell lines tested. Among them, derivative 2, that showed greater bioavailability than RSV, was the most active, particularly against estrogen receptor positive (ER+) MCF7 and estrogen receptor negative (ER-) MDA-MB231 breast cancer cell lines. Moreover, we demonstrated that these derivatives, particularly derivative 2, were able to inhibit NO and ROS synthesis and PGE2 secretion in lipopolysaccharide (LPS)-activated U937 human monocytic cells (derived from a histiocytoma). In order to define the molecular mechanisms underlying the antiproliferative effects of derivative 2, we found that it determined cell cycle arrest at the G1 phase, modified the expression of cell cycle regulatory proteins, and ultimately triggered apoptotic cell death in both breast cancer cell lines. Taken together, these results highlight the studied RSV derivatives, particularly derivative 2, as promising tools for the development of new and more bioavailable derivatives useful in the treatment of breast cancer. 相似文献
4.
5.
The influence of interlayer composition in the surface charge and reactivity of layered double hydroxides (LDHs) has been explored. With this purpose, a chloride-intercalated Zn–Cr-LDH has been synthesized by the constant pH coprecipitation method and afterwards exchanged with carbonate to obtain solids with different Cl?/CO32? ratios. The solids structure has been characterized by elemental chemical analysis, powder X-ray diffraction and infrared spectroscopy, while its surface-charging behavior and reactivity have been studied by acid–base potentiometric titrations and electrophoretic mobility determinations. The chloride-intercalated sample shows an increasing hydroxyl adsorption with increasing pH and decreasing support electrolyte concentration and the particles present positive electrophoretic mobility in the measured pH range. As carbonate content increases in the samples, the total OH? uptake diminishes and the samples show an isoelectric point at pH around 10. When the gallery is totally occupied by carbonate anions, the OH uptake vs. pH curves registered at different electrolyte concentrations merge at around pH 10. A LDH–water interface model has been used to give an interpretation to the experimental data. The model indicates that as carbonate content increases, the sample behavior becomes similar to that of a metal (hydr)oxide and that surface (bi)carbonate anions undergo acid–base reactions. 相似文献
6.
7.
Effect of montmorillonite clay addition on the morphological and physical properties of Jatropha curcas L. and Glycine max L. protein concentrate films
下载免费PDF全文
![点击此处可从《应用聚合物科学杂志》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Alex Osorio‐Ruiz Javier Solorza‐Feria Bor‐Sen Chiou Delilah F. Wood Tina G. Williams Roberto J. Avena‐Bustillos Alma‐Leticia Martínez‐Ayala 《应用聚合物科学杂志》2017,134(7)
Protein concentrates from jatropha (JPC) and soy seeds (SPC) were obtained by solubilization and acid precipitation of proteins. JPC and SPC films were prepared by the casting method, using two different montmorillonite (MMT) clay concentrations and plasticized with glycerol. Film properties were evaluated by scanning electron microscopy, transmission electron microscopy, X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, thermogravimetric analysis, tensile properties, water retention, and water vapor transmission rate (WVRT). Typical tactoid microcomposite structures were found to be heterogeneously dispersed in the films containing MMT. A small XRD peak was found in films with MMT. Slight improvements in thermal stability and tensile strength were observed in the films with MMT. Reductions in water retention and WVRT were obtained when MMT was added into the films. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44459. 相似文献
8.
9.
10.
Silvia A. Fuente Patricia G. Belelli Norberto J. Castellani Marcelo Avena 《Materials Chemistry and Physics》2013
The electronic and structural properties of bulk goethite and Al-rich goethite were studied on the basis of spin-polarized DFT at the LDA + U and GGA(PW91) + U levels. Firstly, the periodic model of bulk goethite was optimized varying the value of Ueff. Considering all the results obtained we can conclude that the bulk goethite described at the GGA + U level with Ueff = 6 eV gives us the better agreement with different physical properties. The results of magnetic moments of Fe ions, the DOS analysis and the Bader atomic charges identify goethite as an antiferromagnetic Fe(III) compound. For Al-rich goethite the GGA + U (Ueff = 6 eV) approach was used. The isomorphous substitution of one Fe ion with Al ion produces the reduction of the cell parameters with respect to the bulk goethite. Regarding the magnetic ordering, it was observed that Fe atoms surrounding the Al atom must have the same spin projection, i.e., spin-up or -down. The charge density was changed with the addition of Al ion, producing a depletion where the ion is located and some electron redistribution in the zone of the oxygen atoms surrounding the Al ion. This behavior produces some small magnetization in these O ions. 相似文献