University of Alicante

About: University of Alicante is a education organization based out in Alicante, Spain. It is known for research contribution in the topics: Catalysis & Population. The organization has 8681 authors who have published 22690 publications receiving 476064 citations. The organization is also known as: Universitat d'Alacant & Universidad de Alicante.

Role of membrane lipids in the interaction of daunomycin with plasma membranes from tumor cells: implications in drug-resistance phenomena.

Abstract: Equilibrium binding studies on the interaction between the anthracycline daunomycin and plasma membrane fractions from daunomycin-sensitive and -resistant murine leukemia P-388 cells are presented. Drug binding constants (KS) are 15,000 and 9800 M-1 for plasma membranes from drug-sensitive and drug-resistant cells, respectively. Drug binding to the membranes is not affected by either (i) thermal denaturation of membrane proteins or (ii) proteolytic treatment with trypsin, thus suggesting that the protein components of the membranes do not have a major role in determining the observed drug binding. Also, fluorescence resonance energy transfer between tryptophan and daunomycin in the membranes indicates that interaction of protein components with the drug should not be responsible for the observed differences in drug binding exhibited by plasma membranes from drug-sensitive and -resistant cells. Plasma membranes from drug-sensitive cells contain more phosphatidylserine and slightly less cholesterol than membranes from drug-resistant cells. Differences in the content of the acidic phospholipid between the two plasma membranes seem to produce a different ionic environment at membrane surface domains, as indicated by titration of a membrane-incorporated, pH-sensitive fluorescence probe. The possible role of membrane lipids in modulating drug binding to the membranes was tested in equilibrium binding studies using model lipid vesicles made from phosphatidylcholine, phosphatidylserine, and cholesterol in different proportions. The presence of phosphatidylserine greatly increases both the affinity and the stoichiometry of daunomycin binding to model lipid vesicles. The similarity between the effects of phosphatidylserine and other negatively charged compounds such as dicetyl phosphate, cardiolipin, or phosphatidic acid suggests that electrostatic interactions are important in the observed binding of the drug.(ABSTRACT TRUNCATED AT 250 WORDS)

Integration of quality management and environmental management systems: Similarities and the role of the EFQM model

Abstract: Purpose – Quality management (QM) and environmental management (EM) systems have several similarities. These parallels may facilitate the development of an integrated system (QEM system). A QEM system is a full, single system where quality and environmental issues are taken into account at the same time, and where QM and EM systems lose their independence. The purpose of this paper is to identify the main benefits to be derived from the integration of QM and EM systems, and to use the European Foundation for Quality Management (EFQM) model as a bridge toward the implementation of a QEM system.Design/methodology/approach – First, an extensive literature review about the parallels between QM and EM systems is conducted. Second, the criteria of the EFQM model are taken into account to develop an integrated system.Findings – The literature review identifies several similarities between QM and EM systems, including the reasons to implement them, benefits derived from their adoption, positive influence on cost ...

The Holy Grail: Environmental management, competitive advantage and business performance in the Spanish hotel industry

Abstract: Purpose - This paper aims to analyse the influence of environmental proactivity on cost and differentiation competitive advantages, and to explore the double relationship between environmental proactivity and business performance. Design/methodology/approach - The population consists of all three- to five-star hotels in Spain. A sample of 350 hotels was classified according to environmental proactivity and performance levels, employing a two-step cluster analysis. Significant differences between groups were examined. Findings - The results show two types of environmental behaviour (reactive and proactive), with proactive hotels developing significantly better on both cost and differentiation competitive advantage and achieving significantly higher performance levels. Hotels which achieve above average business performance levels are significantly more environmentally proactive. Research limitations/implications - The present paper demonstrates that environmental management is related to competitive advantages and business performance. Environmental management systems are more developed in higher category, chain-affiliated and larger hotels. This could be due to having more resources to develop their environmental capability. The environmental proactivity scale employed in this study is presented as a reference measure for hotel managers to benchmark their current practices and implement environmental improvements. Originality/value - First, measuring environmental proactivity using four managerial systems (operative, information, strategic and technical) is innovative and provides a more detailed approach to measuring environmental proactivity. Second, demonstrating a double association between environmental proactivity and performance provides fresh insights into the relationship between these variables.

Selective Catalytic Reduction at Quasi-Perfect Pt(100) Domains: A Universal Low-Temperature Pathway from Nitrite to N2

Abstract: The highly selective conversion of nitrite to N(2) at a quasi-perfect Pt(100) electrode in alkaline media was investigated with a particular emphasis on its structure sensitivity and its mechanism. High-quality (100) terraces are required to optimize the catalytic activity and steer the selectivity to N(2): defects of any symmetry dramatically reduce the N(2) evolution at [(100) × (110)] and [(100) × (111)] surfaces. On the other hand, nitrite reduction proves to be an additional example of the unique intrinsic ability of (100) surfaces to catalyze reactions involving bond breaking and successive bond formation. In the present case, (100) is able to reduce nitrite to NH(2,ads), which in a certain potential window combines with NO(ads) to give N(2) in a Langmuir-Hinshelwood reaction. Our findings are similar to those for other processes generating N(2), from bacterial anoxic ammonia oxidation ("anammox") to the high-temperature NO + NH(3) reaction at Pt(100) crystals under ultra-high-vacuum conditions, thus suggesting that the combination of these two nitrogen-containing species is a universal (low-temperature) pathway to N(2). The advantages of this pathway over other N(2)-generating pathways are pointed out.