Azorin J.,Metropolitan Autonomous University
Applied Radiation and Isotopes | Year: 2014
Many different natural minerals and synthetic inorganic compounds present the phenomenon of thermoluminescence (TL); however, only a part of them satisfy the requirements to be used as TL dosimeters. The mechanism of excitation energy transformation into the output of light is one of the most important points in the TL materials designing. Both the threshold detection dose and accuracy of measurements depend on the efficiency of energy transformation.The role of diverse mechanisms of energy transfer and energy losses is very different depending on the nature of the TL material and its composition including intrinsic defects and those induced by impurities. The structure of these defects can be controlled to a high extent by the preparation method. That is why the most important fact is to find the interrelations among the preparation methods, the structural defects and the TL properties of the material.The aim of this paper is to give a selected review on the preparation methods of the most popular and commercially available phosphors as well as those less used or "homemade" for special studies. © 2013 Elsevier Ltd.
Ireta J.,Metropolitan Autonomous University
Journal of Chemical Theory and Computation | Year: 2011
Under certain circumstances β-sheets prefer to be twisted instead of flat. To get insight into the reasons of such preference, bare and microsolvated parallel and antiparallel two-strand polyalanine β-sheets are investigated using density functional theory. Full geometry optimizations show that microsolvation increases interstrand twisting and promotes a flat to twist transition. It is found that the latter behavior is connected to compressive strain resulting from microsolvation. Residues in flat β-sheets adjust the sense of its local intrastrand twist, which leads to the appearance of interstrand twist, to release strain and to favor water-water hydrogen bonding. The predicted microsolvation effect is corroborated analyzing the geometry of residues forming β-sheet motifs in protein crystals. © 2011 American Chemical Society.
Hernandez-Guerrero M.,Metropolitan Autonomous University |
Stenzel M.H.,University of New South Wales
Polymer Chemistry | Year: 2012
Among various structuring techniques, a water-driven 'templating' method for the fabrication of highly ordered porous membranes has been widely exploited for the past 17 years due to its versatility and robustness. This simple method relies on the formation of "breath figures" and the assembly of a polymer around them, resulting in the production of membranes with hexagonally arranged pores known as honeycomb structured porous polymer films/membranes. Herein, we present a review of relevant literature to stress on the advantages of this simple templating method compared with the wide range of conventional templating and lithographic techniques that have been previously used in the field. Furthermore, we present a comprehensive review on the progress in the field including the study of relevant variables, the materials that have been used, the combination of the method with other techniques, some current and potential applications for the membranes as well as characterization techniques. © 2012 The Royal Society of Chemistry.
Performance of the 2012 Systemic Lupus International Collaborating Clinics and the 1997 American College of Rheumatology classification criteria for systemic lupus erythematosus in a real-life scenario
Amezcua-Guerra L.M.,Metropolitan Autonomous University
Arthritis Care and Research | Year: 2015
Objective. To evaluate the performance of the 2012 Systemic Lupus International Collaborating Clinics (SLICC) criteria in classifying systemic lupus erythematosus (SLE) in an uncontrolled real-life scenario. Methods. Chart review study was performed in which each criterion from the 1997 American College of Rheumatology (ACR) and the 2012 SLICC criteria to classify SLE was applied to patients from an outpatient rheumatology clinic. The clinical diagnosis was used as the gold standard. Results. The sensitivity and specificity of the 2012 SLICC criteria were 92% and 99%, respectively, compared with the 1997 ACR criteria, which were 97% and 99%, respectively. The 2012 SLICC criteria were similar to the 1997 ACR criteria in terms of positive (98.9% versus 99%) and negative (92.5% versus 97.1%) predictive values as well as positive (92 versus 97) and negative (0.08 versus 0.03) likelihood ratios. A concordance of 0.96 (95% confidence interval [95% CI] 0.92-1.00) was observed between clinical diagnosis and the 1997 ACR criteria, while the concordance was 0.91 (95% CI 0.85-0.97) for the 2012 SLICC criteria. Seven SLE patients classified by the 1997 ACR criteria did not meet the 2012 SLICC criteria because of either the new definition for lymphopenia (2 patients) or the presence of isolated cutaneous involvement (5 patients), while 2 SLE patients who were classified by the 2012 SLICC criteria did not meet the 1997 ACR criteria because of either the presence of erosive arthritis or biopsy-proven nephritis with circulating antinuclear antibodies. Conclusion. Overall, the 1997 ACR and the 2012 SLICC criteria are similar to classify SLE in an uncontrolled real-life scenario, although several new items contained in the 2012 SLICC criteria could represent a step forward for research purposes in selected clinical settings. © 2015, American College of Rheumatology.
Rodriguez L.,Metropolitan Autonomous University
International journal of environmental research and public health | Year: 2011
Infectious disease is the major cause of morbidity and mortality in developing countries, particularly in children. Increasing evidence suggests that protein-calorie malnutrition is the underlying reason for the increased susceptibility to infections observed in these areas. Moreover, certain infectious diseases also cause malnutrition, which can result in a vicious cycle. Malnutrition and bacterial gastrointestinal and respiratory infections represent a serious public health problem. The increased incidence and severity of infections in malnourished children is largely due to the deterioration of immune function; limited production and/or diminished functional capacity of all cellular components of the immune system have been reported in malnutrition. In this review, we analyze the cyclical relationship between malnutrition, immune response dysfunction, increased susceptibility to infectious disease, and metabolic responses that further alter nutritional status. The consequences of malnutrition are diverse and included: increased susceptibility to infection, impaired child development, increased mortality rate and individuals who come to function in suboptimal ways.