Search results for "PreP"
showing 10 items of 1334 documents
Fast, non-toxic, and inexpensive n-butanol preparation of recombinant plasmids
2000
Various commercial and non-commercial plasmid preparation protocols are currently available. However, the kits are expensive and many of the protocols contain toxic chemicals. Here we present a novel, optimized and, therefore, very advantageous plasmid preparation protocol using n-butanol. The preparation can be performed quickly and no toxic chemicals are used, at overall costs of about one cent per plasmid preparation.Atualmente vários protocolos comerciais e não comerciais para preparação de plasmídeos estão disponíveis. Contudo, os kits são caros e muitos dos protocolos contêm substâncias químicas tóxicas. Apresentamos neste trabalho um novo, otimizado e portanto muito vantajoso protoco…
L'influence de l'hyperthyroidisation expérimentale sur le plumage des oiseaux carnivores: (note préliminaire) [Gaļas ēdāju putnu spalvojuma atkarība …
1931
Teksts franču valodā, kopsavilkums latviešu valodā.
Antoniego Zabłockiego relacja o pobycie Katarzyny II i Józefa II w Chersoniu i na Krymie w roku 1787
2022
From July 1784 to mid-1792, a Polish trade and diplomatic post operated in Kherson (until the spring of 1788), and then in Mirgorod, in the Black Sea territories of the Russian Empire. From mid-1784 until the end of 1791, Antoni Zabłocki, a former soldier of the Crown Army, the Bar Confederate, and an exile in Russia, was the head of the facility, and from the summer-autumn 1786, the consul. He did not have any diplomatic preparation, and his qualifications were limited to the knowledge of the Russian language and the realities of social and economic life in the tsarist state, as well as to close contacts with the surroundings of King Stanisław August. This secured him a job as a royal agen…
Application potential of dummy molecularly imprinted polymers as solid-phase extraction sorbents for determination of low-mass polybrominated dipheny…
2019
Abstract Despite the introduction of restrictive regulations in the USA and the European Union, polybrominated diphenyl ethers (PBDEs) are still found in various types of environmental and biological samples at significant concentration levels. The presence of these persistent organic pollutants in the environment raises important issues because of their negative impact on immunological and neurological systems, and on the hormonal balances in living organisms. From the analytical point of view, the final determination of PBDEs would entail substantial challenges, because it would necessitate conducting the pre-concentration of analytes, or sample clean up. The aim of the present study is t…
Strategies for the rapid characterization of metals and organic pollutants in solid wastes and contaminated soils by using mass spectrometry
1998
Abstract Hyphenated techniques involving mass spectrometry (MS) such as ICP-MS, GC–MS and LC–MS are the most powerful tools for both qualitative and quantitative characterization of metals and organic pollutants in previously dissolved or extracted samples. However a considerable analytical effort is required in developing simple and general sample preparation strategies for the complete characterization of toxic substances in solid wastes and soils. This article gives a critical review of the state-of-the-art and future perspectives for rapid procedures to evaluate the pollution of soils and sediments, also considering new alternatives like flow injection analysis–MS and direct sampling MS.
FIA-AAS determination of salicylic acid by a solid-phase reactor of copper carbonate incorporated in polyester resin beads.
1994
Abstract The determination of salicylic acid was carried out by reaction of the drug with copper carbonate entrapped in a polymeric material in a solid-phase reactor; the released cupric ions were monitored by flame atomic absorption at 324.8 nm. The calibration graph is linear over the range 4.0–75 μg ml −1 of salicylic acid, with a relative standard deviation of less than 1.5% and a sample throughout of 257 h −1 . The influence of foreign compounds was studied and the method was applied to the determination of salicylic acid content in two different pharmaceutical formulations.
Cure monitoring of catalysed cyanate ester resins
2000
The cure behaviour of two bisphenol A-based cyanate ester resins, AroCy B10 and B30, catalysed by copper acetylacetonate and nonylphenol was studied. For this purpose, differential scanning calorimetric (DSC) and rheological measurements were carried out at temperatures between 130 and 170 °C. The cyanate conversion profiles are fitted with a second-order rate law in the kinetically controlled regime where a good time–temperature superposition is attained. However, it is necessary to add an empirical kinetic term to give a good description of the entire range of curing. Simultaneously, times to gelation and vitrification have been determined by dynamic rheological measurements over the same…
Functionalization of Active Ester-Based Polymersomes for Enhanced Cell Uptake and Stimuli-Responsive Cargo Release
2016
Poly(2,3-dihydroxypropyl methacrylamide) (P(DHPMA))-based amphiphilic block copolymers have recently proven to form polymer vesicles (polymersomes). In this work, we further expand their potential by incorporating (i) units for pH-dependent disintegration into the hydrophobic membrane and (ii) mannose as targeting unit into the hydrophilic block. This last step relies on the use of an active ester prepolymer. We confirm the stability of the polymersomes against detergents like Triton X-100 and their low cytotoxicity. The incorporation of 2-(2,2-dimethyl-1,3-dioxolane-4-yl)ethyl methacrylate into the hydrophobic block (lauryl methacrylate) allows a pH-responsive disintegration for cargo rele…
UV-photocrosslinking of inulin derivatives to produce hydrogels for drug delivery application.
2005
In this work, INU, a natural polysaccharide, has been chemically modified in order to obtain new photocrosslinkable derivatives. To reach this goal, INU has been derivatized with MA thus obtaining four samples (INU-MA derivatives) as a function of the temperature and time of reaction. An aqueous solution of the derivative INU-MA1 was irradiated by using a UV lamp with an emission range from 250 to 364 nm and without using photoinitiators. The obtained hydrogel showed a remarkable water affinity but it underwent a partial degradation in simulated gastric fluid. To overcome this drawback, INU-MA 1 was derivatized with SA thus obtaining the INU-MA1-SA derivative designed to produce a hydrogel …
CONTROLLED RELEASE OF IgG BY NOVEL UV INDUCED POLYSACCHARIDE/POLY(AMINO ACID)HYDROGELS
2009
The development of new protein and peptide drugs needs new delivery systems able to entrap such drugs in safe conditions without affecting their structure and biological activity. In this context, the present work reports a new approach to load IgG, used as a model of therapeutic proteins such as anti-TNF-alpha monoclonal antibodies, into a polymeric system able to release the entrapped IgG in a controlled manner. In particular, new polysaccharide/poly(amino acid) UV induced hydrogels are proposed as colon delivery systems for human IgG. The poly(amino acid), alpha,beta-poly[N-(2-hydroxyethyl)-D,L-aspartamide], has been functionalized with methacrylic anhydride, while the polysaccharide, in…