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71.
Marek Bučko Danica Mislovičová Jozef Nahálka Alica Vikartovská Jana Šefčovičová Jaroslav Katrlík Ján Tkáč Peter Gemeiner Igor Lacík Vladimír Štefuca Milan Polakovič Michal Rosenberg Martin Rebroš Daniela Šmogrovičová Juraj Švitel 《Chemical Papers》2012,66(11):983-998
Biological molecules such as enzymes, cells, antibodies, lectins, peptide aptamers, and cellular components in an immobilized form are extensively used in biotechnology, in biorecognition and in many medicinal applications. This review provides a comprehensive summary of the developments in new immobilization materials, techniques, and their practical applications previously developed by the authors. A detailed overview of several immobilization materials and technologies is given here, including bead cellulose, encapsulation in ionotropic gels and polyelectrolyte complexes, and various immobilization protocols applied onto surfaces. In addition, the review summarises the screening and design of an immobilization protocol, practical applications of immobilized biocatalysts in the industrial production of metabolites, monitoring, and control of fermentation processes, preparation of electrochemical/optical biosensors and biofuel cells. 相似文献
72.
Ielpo P Cassano D Lopez A Pappagallo G Uricchio VF De Napoli PA 《Chemistry Central journal》2012,6(Z2):S5
Background
Ground waters are an important resource of water supply for human health and activities. Groundwater uses and applications are often related to its composition, which is increasingly influenced by human activities.In fact the water quality of groundwater is affected by many factors including precipitation, surface runoff, groundwater flow, and the characteristics of the catchment area. During the years 2004-2007 the Agricultural and Food Authority of Apulia Region has implemented the project “Expansion of regional agro-meteorological network” in order to assess, monitor and manage of regional groundwater quality. The total wells monitored during this activity amounted to 473, and the water samples analyzed were 1021. This resulted in a huge and complex data matrix comprised of a large number of physical-chemical parameters, which are often difficult to interpret and draw meaningful conclusions. The application of different multivariate statistical techniques such as Cluster Analysis (CA), Principal Component Analysis (PCA), Absolute Principal Component Scores (APCS) for interpretation of the complex databases offers a better understanding of water quality in the study region.Results
Form results obtained by Principal Component and Cluster Analysis applied to data set of Foggia province it’s evident that some sampling sites investigated show dissimilarities, mostly due to the location of the site, the land use and management techniques and groundwater overuse. By APCS method it’s been possible to identify three pollutant sources: Agricultural pollution 1 due to fertilizer applications, Agricultural pollution 2 due to microelements for agriculture and groundwater overuse and a third source that can be identified as soil run off and rock tracer mining.Conclusions
Multivariate statistical methods represent a valid tool to understand complex nature of groundwater quality issues, determine priorities in the use of ground waters as irrigation water and suggest interactions between land use and irrigation water quality.73.
Gomes de Melo J de Sousa Araújo TA Thijan Nobre de Almeida e Castro V Lyra de Vasconcelos Cabral D do Desterro Rodrigues M Carneiro do Nascimento S Cavalcanti de Amorim EL de Albuquerque UP 《Molecules (Basel, Switzerland)》2010,15(12):8534-8542
The objective of this study was to evaluate antiproliferative activity, antioxidant capacity and tannin content in plants from semi-arid northeastern Brazil (Caatinga). For this study, we selected 14 species and we assayed the methanol extracts for antiproliferative activity against the HEp-2 (laryngeal cancer) and NCI-H292 (lung cancer) cell lines using the (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazole) (MTT) method. In addition, the antioxidant activity was evaluated with the DPPH (2,2-diphenyl-2-picrylhydrazyl) assay, and the tannin content was determined by the radial diffusion method. Plants with better antioxidant activity (expressed in a dose able to decrease the initial DPPH concentration by 50%, or IC50) and with higher levels of tannins were: Poincianella pyramidalis (42.95±1.77 μg/mL IC50 and 8.17±0.64 tannin content), Jatropha mollissima (54.09±4.36μg/mL IC50 and 2.35±0.08 tannin content) and Anadenanthera colubrina (73.24±1.47 μg/mL IC50 and 4.41±0.47 tannin content). Plants with enhanced antiproliferative activity (% living cells) were Annona muricata (24.94±0.74 in NCI-H292), Lantana camara (25.8±0.19 in NCI-H292), Handroanthus impetiginosus (41.8±0.47 in NCI-H292) and Mentzelia aspera (45.61±1.94 in HEp-2). For species with better antioxidant and antiproliferative activities, we suggest future in vitro and in vivo comparative studies with other pharmacological models, and to start a process of purification and identification of the possible molecule(s) responsible for the observed pharmacological activity. We believe that the flora of Brazilian semi-arid areas can be a valuable source of plants rich in tannins, cytotoxic compounds and antioxidant agents. 相似文献
74.
Dos Santos VA Dos Santos DP Castro-Gamboa I Zanoni MV Furlan M 《Molecules (Basel, Switzerland)》2010,15(10):6956-6973
This work describes the isolation of the secondary metabolites identified as the quinonemethides maytenin (1) and pristimerin (2) from Maytenus ilicifolia extracts obtained from root barks of adult plants and roots of seedlings and their quantification by high performance liquid chromatography coupled to a diode array detector. The electrochemical profiles obtained from cyclic voltammetry and a coulometric detector coupled to high-performance liquid chromatography contributed to the evaluation of their antioxidant capacity. The antioxidant properties of individual components and the crude extracts of the root barks of Maytenus ilicifolia were compared and the possible synergistic associations of quinonemethide triterpenes and phenolic substances were investigated by using rutin as a model phenolic compound. 相似文献
75.
Daniela Belli Dell’Amico Luca Labella Fabio Marchetti Simona Samaritani 《Coordination chemistry reviews》2010,254(5-6):635-645
In this review we summarize some recent literature data concerning synthetic procedures, properties, structure, reactivity and applications of halo-carbonyl complexes of palladium, platinum and gold, taking into consideration that the organometallic chemistry of these metals, with a particular attention to the halo-carbonyls, has been reviewed 20 years ago [F. Calderazzo, J. Organomet. Chem. 400 (1990) 303]. A brief overview of the early studies is provided. 相似文献
76.
p-tert-Butylcalix[4]arene, [CalixBut(OH)4], reacts with Mo(PMe3)6 and W(PMe3)4(eta2-CH2PMe2)H to yield compounds of composition {[CalixBut(OH)2(O)2]M(PMe3)3H2} which exhibit unprecedented use of a C-H bond of a calixarene methylene group as a binding functionality in the form of agostic and alkyl hydride derivatives. Thus, X-ray diffraction studies demonstrate that, in the solid state, the molybdenum complex [CalixBut(OH)2(O)2]Mo(PMe3)3H2 exists as an agostic derivative with a Mo...H-C interaction, whereas the tungsten complex exists as a metallated trihydride [Calix-HBut(OH)2(O)2]W(PMe3)3H3. Solution 1H NMR spectroscopic studies, however, provide evidence that [Calix-HBut(OH)2(O)2]W(PMe3)3H3 is in equilibrium with its agostic isomer [CalixBut(OH)2(O)2]W(PMe3)3H2. Dynamic NMR spectroscopy also indicates that the [M(PMe3)3H2] fragments of both the molybdenum and tungsten complexes [CalixBut(OH)2(O)2]M(PMe3)3H2 migrate rapidly around the phenolic rim of the calixarene on the NMR time scale, an observation that is in accord with incorporation of deuterium into the methylene endo positions upon treatment of the isomeric mixture of [CalixBut(OH)2(O)2]W(PMe3)3H2 and [Calix-HBut(OH)2(O)2]W(PMe3)3H3 with D2. Treatment of {[CalixBut(OH)2(O)2]W(PMe3)3H2} with Ph2C2 gives the alkylidene complex [CalixBut(O)4]W=C(Ph)Ar [Ar = PhCC(Ph)CH2Ph]. 相似文献
77.
78.
Scott Gaynor Dorota Greszta Daniela Mardare Mircea Teodorescu Krzysztof Matyjaszewski 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1561-1578
Various methods which lead to the control of molecular weight and polydispersities, and which allow for the preparation of block copolymers by radical polymerization are discussed. Thermal polymerizationof styrenes in the presence of stable radicals, polymerization of vinyl acetate and methyl methacrylate in the presence of chromium complexed by macrocyclic ligands polymerization of vinyl acetate initiated by organoaluminum compounds complexed by dipyridyl and activated by stable radicals, as well as in the presence of phosphites, are described in detail. 相似文献
79.
80.
Lucilena Rebelo Monteiro Daniela Graffitti Filipe Albano Darilena Porfírio Laercio Pires Fernandes Junior Marycel E. B. Cotrim Maria Aparecida Faustino Pires 《Accreditation and quality assurance》2013,18(3):207-215
This paper describes a Brazilian interlaboratory program study on anion measurement in synthetic water. The program described is promoted regularly since 2007 and recommended the use of ion chromatography as analytical technique for all participant laboratories. Two samples (X and Y) with different anion (fluoride, chloride, nitrite-N, nitrate-N, sulfate and phosphate-P) concentration levels were twice distributed in 2011. Each sample on each round had the homogeneity, and the stability tested for a period of 15 days. Upon ensuring the homogeneity and stability, the samples were distributed to 39 laboratories located around the country. The aim of this study was to verify the laboratories’ precision and to establish the measurement comparability among Brazilian laboratories that routinely use ion chromatography for water sample analysis. It was also possible to identify the most frequent sources of systematic and random errors for each measured anion, related to the ion chromatography technique. Some specific metrological issues related to the geographical region are discussed. 相似文献