Search results for "Gels"
showing 10 items of 671 documents
Monte Carlo simulation of DNA electrophoresis
1989
This paper describes an attempt to study the electrophoresis mobility of a DNA molecule in a gel by means of a Monte Carlo simulation. We find that the electrophoresis mobility mu can be well described by the empirical equation mu v kappa 1/N + kappa 2E2 with N being the number of monomers of the model chain and E being the applied field. For small E the data can merge into the linear response result mu = kappa 1/N. The paper also discusses necessary extensions of the present approach.
Engels on Corruption
2021
Kirja-arvio käsittelee johtavan saksalaisen korruptiotutkija Jens Ivo Engelsin kahta laajaa tutkimusta. Arviossa Engelsin havainnot yhdistetään Suomen lähihistorian kuuluisimpaan ”lautakasajupakkaan” eli silloisen pääministeri Matti Vanhasen tapaukseen vuodelta 2009. nonPeerReviewed
Equilibrium swelling properties of polyampholytic hydrogels
1996
The role of counter ions and ion dissociation in establishing the equilibrium swelling of balanced and unbalanced polyampholytic hydrogels has been investigated experimentally and theoretically. The swelling dependence on both the net charge offset and the external bath salt concentration has been examined using an acrylamide based polyampholytic hydrogels. By careful consideration of the swelling kinetics, we illustrate the effects of ion dissociation equilibria and counter ion shielding in polyampholytic hydrogels near their balance point where both polyelectrolyte and polyampholyte effects are present. The theory considers a Flory type swelling model where the Coulombic interactions betw…
Swellable microparticles containing Suprofen: evaluation of in vitro release and photochemical behaviour
1998
Suprofen, an anti-inflammatory drug was incorporated in polymer networks based on biocompatible macromolecules, such as alpha,beta-polyasparthydrazide (PAHy) and alpha,beta-poly(N-hydroxyethyl)-DL-aspartamide (PHEA) crosslinked by glutaraldehyde or gamma-rays, respectively. Swelling tests carried out in aqueous media showed that pH value affects the swelling degree of the prepared hydrogels. In vitro release tests were performed in simulated gastrointestinal fluids (pH 1/6.8) using the pH variation method and in phosphate-buffered saline, pH 7.4. Experimental data indicated that Suprofen was released in a sustained way both from PAHy and PHEA microparticles. Further, incorporation of Suprof…
“Dumb” pH-Independent and Biocompatible Hydrogels Formed by Copolymers of Long-Chain Alkyl Glycidyl Ethers and Ethylene Oxide
2020
The formation and rheological properties of hydrogels based on amphiphilic ABA triblock polyether copolymers are described, relying solely on the hydrophobic interaction of long-chain alkyl glycidyl ether (AlkGE)- based A-blocks that are combined with a hydrophilic poly(ethylene glycol) (PEG) midblock. Via anionic ring-opening copolymerization (AROP), ethylene oxide (EO) and long-chain alkyl glycidyl ethers (AlkGEs) were copolymerized, using deprotonated poly(ethylene glycol) (PEG) macroinitiators (Mn of 10, 20 kg mol-1). The polymerization afforded amphiphilic ABA triblock copolymers with molar masses in the range of 21-32 kg mol-1 and dispersities (Đ) of Đ = 1.07-1.17. Kinetic studies rev…
Marxismo y nacionalismo
2010
Capítulo del libro Cosmopolitismo y nacionalismo. De la ilustración al mundo contemporáneo en el que se exponen los principios básicos de la filosofía de la praxis marxista y se discute la comprensión que Marx y Engels tuvieron del nacionalismo.
Availability of alternative financial resources for SMES as a critical part of the entrepreneurial eco-system: Latvia and Italy
2015
Abstract The importance of non-traditional alternative/innovative financing is gaining recognition in both developed and emerging economies throughout the world (OECD, 2012; EC, 2013; ECB, 2013; ECB, 2014). SME financing in Europe remains primarily bank based, in spite of the many policies proposed to develop alternative financing instruments (e.g. adopting directives on venture capital, improving the transparency and visibility of SMEs on capital markets, etc.) The paper aims at understanding the availability of alternative resources for SMEs by analyzing them rigorously, understanding the obstacles for the development of non-bank finance and developing recommendations to overcome them. Th…
Business Angel Investments: Risks and Opportunities
2015
Abstract For the last few years the need of improving the access to finance for the companies, especially SME's (small and middle enterprises), has been on the agenda in European Union. As long as the traditional financing such as bank loans became more complex to attract, the development of alternative investment, like seed and start-up capital investments, crowd funding, venture capital and Business angels, became a bold topic. Moreover, there is an opinion that development of alternative investment might be seen as a ground for boosting economic activity and entrepreneurship development. Even though a lot of various studies have been done on the evaluation and description of alternative …
Physics of agarose fluid gels: Rheological properties and microstructure
2021
Agarose, a strongly gelling polysaccharide, is a common ingredient used to optimize the viscoelastic properties of a multitude of food products. Through aggregation of double helices via hydrogen bonds while cooling under quiescent conditions it forms firm and brittle gels. However, this behavior can be altered by manipulating the processing conditions viz shear. For example, gelation under shear leads to microgel particles with large surface area, which in turn leads to completely different rheological properties and texture. Such fluid gels are shown to play an important role in texture modification of foods and beverages for dysphagia patients. In this study, different concentration of a…