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61.
Inmaculada de Vargas Lynne E Macaskie Eric Guibal 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2004,79(1):49-56
The biosorption capacities of palladium and platinum were studied in three different species of Desulfovibrio: Desulfovibrio desulfuricans, Desulfovibrio fructosivorans and Desulfovibrio vulgaris. The influence of several parameters such as pH, acidic background and competitor anions on biosorption equilibria and biosorption kinetics were evaluated. Differences were observed between the three strains of Desulfovibrio with respect to the optimum biosorption parameters of both metals, suggesting differences in the metal speciation–dependent sorption mechanisms involved. The most promising Pd and Pt biosorption results were obtained using D desulfuricans with rapid achievement of equilibrium (90% of total sorption was achieved in 5–15 min) and a maximum value of 190 mg g?1 dry biomass and 90 mg g?1 dry biomass for Pd and Pt accumulation respectively, at pH 3. Copyright © 2003 Society of Chemical Industry 相似文献
62.
Dearomatization levels during electrochemical oxidation of p-methoxyphenol (PMP) and p-nitrophenol (PNP) have been determined through UV-Vis spectroscopy using solid phase extraction (UV-Vis/SPE). The results show that the method is satisfactory to determine the ratio between aromatic compounds and aliphatic acids and reaction kinetics parameters during treatment of wastewater, in agreement with results obtained from numerical deconvolution of UV-Vis spectra. Analysis of solutions obtained from electrolysis of substituted phenols on antimony-doped tin oxide (SnO2Sb) showed that an electron acceptor substituting group favored the aromatic ring opening reaction, preventing formation of intermediate quinone during oxidation. 相似文献
63.
Talavera-Saenz A Gardner SC Riosmena Rodriquez R Acosta Vargas B 《The Science of the total environment》2007,373(1):94-102
The Baja California Peninsula, Mexico serves an important role for feeding and developing sea turtles. High concentrations of metals detected in green turtles (Chelonia mydas) from Magdalena Bay prompted an investigation into the sources of metals in the region. We compared metal concentrations in sea turtle tissues with plant species found in their stomach contents, and with the same species of plants collected inside a sea turtle refuge area known as Estero Banderitas. Differences in the metal concentrations between marine plant species were minimal. Principal components analysis of the percent contribution of individual metals to the overall metal signature of each plant or tissue sample generated three principal components that explained 80.7% of the total variance in the data. The plant samples collected within Estero Banderitas formed a separate grouping from the green turtle tissue samples and the plants from the stomach contents. The plants in the stomach contents contained greater percent contributions of Cd and Zn than the plants collected inside the bay, while Pb and Mn contributed more to the metal profiles in the bay samples. The metal profiles in the sea turtle tissues more closely resembled the stomach contents than the same species of plants collected within Estero Banderitas, and suggest that sea turtles collected inside Magdalena Bay use foraging resources outside of the Estero Banderitas region. This work supports the suggestion that metal profiles can be used as "environmentally acquired markers" to improve our understanding of the extent of sea turtle foraging areas. 相似文献
64.
Nowadays, the serial production of Carbon Fiber-Reinforced Polymers remains a challenge for the industry. Their production and application have been limited by the intensive manual work required to produce them and the resulting elevated manufacturing costs. Moreover, the production handling tasks are fulfilled to a limited extent by the gripping systems currently available in the market. The delicate process and specific material requirements of these polymers compromise the feasibility and use of automated gripper systems. An innovative solution for the automated material handling of carbon fiber textiles developed by the wbk Institute for Production Science in cooperation with J. Schmalz GmbH will be presented in this paper. The main focus of this study deals with measuring principles to increase energy efficiency, process reliability and adaptability of a gripping system using low pressure grippers. This study presents suitable solutions for the implementation of low pressure grippers in a production environment. 相似文献
65.
Palomares Iván Martínez-Cámara Eugenio Montes Rosana García-Moral Pablo Chiachio Manuel Chiachio Juan Alonso Sergio Melero Francisco J. Molina Daniel Fernández Bárbara Moral Cristina Marchena Rosario de Vargas Javier Pérez Herrera Francisco 《Applied Intelligence》2021,51(9):6497-6527
Applied Intelligence - The17 Sustainable Development Goals (SDGs) established by the United Nations Agenda 2030 constitute a global blueprint agenda and instrument for peace and prosperity... 相似文献
66.
PG Deriabin SO Viazov EI Isaeva EI Samokhvalov DK L'vov 《Canadian Metallurgical Quarterly》1997,42(6):254-258
A model of chronic infection of primary cultures of suckling mouse brain (SMB) cells actively producing hepatitis C virus (HCV) is developed. Destruction and repopulation of cells was observed for at least 6 months; this phenomenon was paralleled by virus release in culture medium. Persistent HCV contained in SMB cultures induced a cytopathogenic effect in PS, BHK-21, Vero, HAK, and click embryo cell cultures, its infective titers being 10.0-12.0 lg TCD50/0.2 ml. Persistent HCV formed heterogeneous plaques under agar in chick embryo cells. The polymerase chain reaction (PCR) regularly detected the HCV RNA at the stage of cell destruction in the culture fluid of HCV-infected cell cultures. The cytopathogenic activity of persistent HCV was neutralized by anti-HCV positive patients' sera with the neutralization index of 8.0-9.0 lg. The results of persistent HCV neutralization were confirmed by PCR. Immunofluorescence detected virus-specific HCV antigens in 15-40% of infected cells. Hence, the SMB-HCV system realized the cytopathogenic potential of HCV circulating in the blood of patients with hepatitis C. This system is promising for the study of the pathogenesis of HCV infection at a cellular level, for screening for specific and nonspecific antiviral agents, and for preparing native virus-specific proteins and RNA. 相似文献
67.
68.
Colloidal aggregation induced by the reduction in pH and the synthesis of new molecular structures during the milk fermentation process 下载免费PDF全文
Susana Vargas Rogelio Rodríguez Francisco Quintanilla Maykel González–Torres 《International Journal of Dairy Technology》2018,71(1):56-63
The use of different inocula in the milk‐to‐yoghurt transformation influences the kinetics of the fermentation process. The aim of this work was to study the kinetics induced by Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (Lb–St). The milk‐to‐yoghurt transformation showed no delay in the production of lactic acid for yoghurt produced using Lactobacillus johnsonii with S. thermophilus (La1–St) or Lactobacillus casei with S. thermophilus (Lc1–St); the delays were 20–70 min and 40–80 min, respectively. The absence of delay was 1.0/min (Lb–St) as compared with 0.015/min (La1–St) and 0.7/min (Lc1–St). The kinetics was fitted using second‐order reaction. 相似文献
69.
Alberto Cornejo Francisco Salgado Julio Caballero Reinaldo Vargas Mario Simirgiotis Carlos Areche 《International journal of molecular sciences》2016,17(8)
Liquid chromatography coupled with mass spectrometry is an outstanding methodology for fast analysis of phenolic compounds in biological samples. Twenty two compounds were quickly and accurately identified in the methanolic extract of the Antarctic lichen Ramalina terebrata for the first time using ultra high pressure liquid chromatography coupled with photodiode array detector and high resolution mass spectrometry (UHPLC-PDA-Q/Orbitrap/MS/MS). In addition, the extract and the four compounds isolated from this species were tested for the inhibitory activity of tau protein aggregation, which is a protein involved in Alzheimer’s disease (AD). All compounds showed null activity with the exception of parietin, which it was able to inhibit aggregation process of tau in a concentration range between 3 µg/mL (10 µM) to 28 µg/mL (100 µM). In addition, we show how parietin interact with tau 306VQIVYK311 hexapeptide inside of the microtubule binding domain (4R) with the help of molecular docking experiments. Finally, the constituents present in the methanolic extract could possibly contribute to the established anti-aggregation activity for this extract and this in-depth analysis of the chemical composition of R. terebrata could guide further research into its medicinal properties and potential uses. 相似文献
70.
DP Vargas L Giraldo JC Moreno-Piraján 《International journal of molecular sciences》2012,13(7):8388-8397
Activated carbon honeycomb-monoliths with different textural properties were prepared by chemical activation of African palm shells with H(3)PO(4), ZnCl(2) and CaCl(2) aqueous solutions of various concentrations. The adsorbents obtained were characterized by N(2) adsorption at 77 K, and their carbon dioxide adsorption capacities were measured at 273 K and 1 Bar in volumetric adsorption equipment. The experimental adsorption isotherms were fitted to Langmuir and Tóth models, and a better fit was observed to Tóth equation with a correlation coefficient of 0.999. The maximum experimental values for adsorption capacity at the highest pressure (2.627-5.756 mmol·g(-1)) are between the calculated data in the two models. 相似文献