Search results for "oligo"

Rupture Force of Single Small Drug Molecule Binding a Split Aptamer

2012

Aptamers are specific oligonucleotides (DNA or RNA) which bind small inorganic or organic molecules, large proteins or cells. In particular, the high affinity of aptamers is expected to lead to a new class of therapeutic reagents. Thus the detection and characterization of binding strength of small molecules is important for drug and medical research. Atomic force spectroscopy (AFS) with a force resolution in the piconewton range is a valuable tool for studying interactions on a single molecular level. The detection of very small target molecules less than 500 Dalton is characterized by only a few hydrogen interactions between the aptamer and the target molecules. Thus tiny rupture forces w…

1984

Pharmacokinetics of oligodeoxynucleotides encapsulated in liposomes: effect of lipid composition and preparation method

2000

1. The effect of the method employed to prepare liposomes and their lipid composition were evaluated in terms of the encapsulation efficiency and pharmacokinetic features of two oligodeoxynucleotides of a 21 mer: the normal (N-Odn) and the phosphorothioate (S-Odn) oligodeoxynucleotide. 2. Liposomes were prepared by the classical method of multilamellar vesicles (MV) and by the dehydration-rehydration method (DR). Two lipid mixtures were used to prepare liposomes--the predominant lipid being phosphatidylcholine (PC) and sphingomyelin (SM) respectively. 3. The DR method for liposome preparation provided the highest encapsulation efficiency, regardless of liposome lipid composition and the typ…

Pharmacogenomic and molecular docking studies on the cytotoxicity of the natural steroid wortmannin against multidrug-resistant tumor cells

2014

Wortmannin is a cytotoxic compound derived from the endophytic fungi Fusarium oxysporum, Penicillium wortmannii and Penicillium funiculosum that occurs in many plants, including medicinal herbs. The rationale to develop novel anticancer drugs is the frequent development of tumor resistance to the existing antineoplasic agents. Therefore, it is mandatory to analyze resistance mechanisms of novel drug candidates such as wortmannin as well to bring effective drugs into the clinic that have the potential to bypass or overcome resistance to established drugs and to substantially increase life span of cancer patients. In the present project, we found that P-glycoprotein-overexpressing tumor cells…

The Classical Notion of Competition Revisited

2013

This article seeks to fill a lacuna within classical economics concerning the process of market price determination in situations of market disequilibrium. To this aim, first we distinguish the classical notion of free competition from the Walrasian notion of perfect competition and we argue that the latter is beset with some theoretical difficulties alien to the former. Second, we reconstruct in some detail Smith’s and Marx’s views concerning market price determination and show that Marx’s extensive use of metaphors and numerical examples foreshadows the modern taxonomy of buyers’ market, sellers’ market, and mixed strategy equilibrium in the capacity space of a standard Bertrand duopoly m…

More firms, more competition? The case of the fourth operator in France's mobile phone market

2010

Accepted, Forthcoming; International audience; To foster competition the French government authorized a fourth operator, ‘Free', to enter the country's mobile phone market at the end of 2009 alongside Orange, SFR and Bouygues Telecom (BT), who held respectively one-half, one-third and one-sixth of the market. By using a stylized model of France's phone market, we have examined what we call the regulator's nightmares and dreams. If Cournot competition is in place before Free's entry, minimizing the total profit fails to maximize the consumer surplus and the total surplus; the maximum most realistic price fall is 6.7% compared to three-way competition and could be 1.7% only; if Orange, SFR an…

Competition with targeted product design: Price, variety, and welfare

2018

Abstract We consider the price and welfare effects of competition in targeted product design, in the context of the Salop circle model. Changes in product design lead to demand rotations that set the stage for our analysis. With an exogenous number of firms, we show that the degree of targeted product design tends to increase with the number of firms. Moreover, under reasonable conditions, price-increasing competition takes place, for intermediate levels of the number of firms. This effect is associated with the possibility of lower consumer welfare. With endogenous firm entry, an interesting insight from our analysis is that in some situations an increase in market size or a technological …

Product-market integration with endogenous firm heterogeneity

2021

Abstract This paper proposes a general equilibrium oligopoly model in which firm heterogeneity is endogenously reproduced through technology adoption decisions. The model can explain persistent oligopolistic market structures and prices in spite of free entry and market enlargement. Moreover, strong selection might deteriorate average cost efficiency due to strategic interactions. Integrating identical countries can be welfare-improving. But distributional issues and tensions between welfare and scale economies may arise. The theory can be motivated by recent evidence on oligopolistic market structures resisting globalization forces.

INTERNATIONALIZATION STRATEGIES IN OLIGOPOLY WITH HETEROGENEOUS FIRMS

2016

This paper examines the foreign direct investment (FDI) versus exports decision of foreign oligopolistic firms under cost heterogeneity. An additional motivation for firms to invest abroad is the technological sourcing via spillovers, which flow from the host more efficient firm to foreign less advantaged firms. For intermediate values of the set-up costs associated with FDI entry, it is shown that foreign firms choose opposite entry strategies. An equilibrium where the less efficient foreign firm exports whereas the more efficient invests is more likely to happen when foreign firms become more heterogeneous, the larger the trade costs and not too big oligopolistic profitability. Interestin…

A novel approach for analysis of oligonucleotide-cisplatin interactions by continuous elution gel electrophoresis coupled to isotope dilution inducti…

2008

In this work we present a novel approach for in vitro studies of cisplatin interactions with 8-mer oligonucleotides. The approach is based on the recently developed coupling of continuous elution gel electrophoresis (GE) to an inductively coupled plasma-sector field mass spectrometer (ICP-SFMS) with the aim of monitoring the interaction process between this cytostatic drug and the nucleotides. In contrast to existing methods, the electrophoretic separation conditions used here allow both the determination of the reaction kinetics in more detail as well as the observation of dominant intermediates. Two different nucleotides sequences have been investigated for comparison purposes, one contai…