Instability of calcium channel antagonists during sample preparation for LC-MS-MS analysis of serum samples

1,4-Dihydropyridines calcium channel antagonists (1,4-DHP CCAs) are photolabile and the products of their photodecomposition have no pharmaceutical activity. In our previous work we have presented a screening procedure for eleven 1,4-DHPs in plasma by LC-MS-MS using multiple reaction motoring. The laboratory process includes preparation and storage of stock solutions, plasma storage, solid-phase extraction, reconstitution of extracts and storage time in an autosampler for LC-MS-MS analysis. Prior to validation of the analytical procedure, we have tested the stability of these compounds by exposure to light. Methanolic solutions have been exposed to laboratory and UV light and the stability of the compounds in plasma was tested by exposure of spiked plasma samples to laboratory light at room temperature. Stability during freeze-thaw cycles and stability during 2 month storage at -20 degrees C have been tested as well. Products of photodecomposition have been identified after forced degradation and the degree of degradation has been quantified using LC-UV-DAD and LC-MS-MS, respectively. A 96% degradation after only 2h has been observed when solutions of nifedipine or nisoldipine were exposed to laboratory light in clear glass vials. In plasma samples degradation was 25% in only 2h for both compounds. The main degradation product was produced by oxidation of the dihydropyridinic ring resulting in the pyridine analogue that has been described as the first metabolite in the metabolic pathway. Only minor degradation was found for the other tested compounds after 2h light exposure in methanolic solutions. Furthermore, lercanidipine and nicardipine were also degradated by esterhydrolysis. Several additional minor degradation products were found for the other tested 1,4-DHPs, however, some of them could not be identified. Preconditions for storage and handling of plasma samples prior to and during analysis for 1,4-DHP CCAs are suggested in order to avoid photodecomposition of the analytes.     

Technology Competitiveness in Emerging Markets: The Case of the Brazilian Polymer Industry

The Brazilian polymer industry (plastics, rubbers, fibers, adhesives, paints, and varnishes) is the fastest growing segment of the Petrochemical Chain. Since the polymer industry is characterized as science based, the capacity to create technology is vital for its long-range survival in the market. This paper analyzes how Brazilian polymer firms maintain their technological competitiveness, explains the main modes of technology transfer, and evaluates the degree of technological dependence of this industry. The methodology consisted of a database built with data from the Brazilian Patent Office. To confirm the findings, interviews were conducted with staff members from seven Brazilian polymer firms. The data base analysis and the interviews reveal that, in spite of the fact that Research and Development (R&D) and technological innovation have a fundamental role in their competitiveness, the firms are technologically dependent upon foreign suppliers.     

Paving the (Hard) Way for Regional Partnerships: Evidence from Portugal

A fundamental dilemma which troubles advocates of interinstitutional partnerships in regional development pertains to the extent to which partnerships enhance the effectiveness of governance processes and outcomes. This dilemma is particularly relevant in contexts that lack strong cohesive regional development alliances, such as the Portuguese case. This article aims to shed light on the debate regarding the role of partnerships in regional development, drawing on a unique collaborative interinstitutional partnership. It explores the responses to complexity across the different stakeholders, as well as its effects at the formulation and implementation stages of the strategic plans devised to apply for EU funding. Findings suggest that interinstitutional partnerships induce significantly different allocative choices at the agenda-setting. However, the established partnership was unable to cope with the several obstacles that emerged during the implementation, suggesting several vulnerabilities of partnerships, which are explored. Findings suggest the need to reinforce governance mechanisms during the implementation stage.     

Perceptions of Economic Inequality and Support for Redistribution: The role of Existential and Utopian Standards

Perceived greater economic inequality is supposedly associated with higher demand for redistribution. However, the findings in the literature are mixed in this regard, with some researchers providing evidence in favour of this association and some findings evidence against it. Given that perceived economic inequality and endorsement of system-justifying beliefs are related to increased inequality acceptance, we explore the interplay between them in relation to support for redistribution. This study is intended to shed light on the role of utopian standards (ideal estimates about what ought to be) as one mechanism that affects the relationship between perceived greater economic inequality and support for redistribution. Based on correlational data (N?=?794), we conducted a conditional process analysis and found that perceived greater inequality displayed a negative indirect effect on support for redistribution, through acceptance of ideal level of economic inequality: Perception of higher inequality was related to increased ideal levels of inequality and thus with lower support for redistribution. In addition, we found that economic system-justifying beliefs conditioned the effect of perceived economic inequality in two ways: First, perceived economic inequality was positively associated with higher acceptance of inequality, and this association was stronger for those that justified the economic system more, and perceived greater inequality was associated with higher support for redistribution—but only for those who endorsed lower levels of economic system justification beliefs. These findings provide evidence that perceived greater economic inequality does not in itself lead to a push for more redistribution; rather, utopian standards such as ideal estimates of economic inequality, which are conditioned by system-justifying ideologies.