Electronic structure, linear, nonlinear optical susceptibilities and birefringence of CuInX2 (X = S, Se, Te) chalcopyrite-structure compounds

The electronic structure, linear and nonlinear optical properties have been calculated for CuInX2 (X=S, Se, Te) chalcopyrite-structure single crystals using the state-of-the-art full potential linear augmented plane wave (FP-LAPW) method. We present results for band structure, density of states, and imaginary part of the frequency-dependent linear and nonlinear optical susceptibilities. We find that these crystals are semiconductors with direct band gaps. We have calculated the birefringence of these crystals. The birefringence is negative for CuInS2 and CuInSe2 while it is positive for CuInTe2 in agreement with the experimental data. Calculations are reported for the frequency-dependent complex second-order non-linear optical susceptibilities . The intra-band and inter-band contributions to the second harmonic generation increase when we replace S by Se and decrease when we replace Se by Te. We find that smaller energy band gap compounds have larger values of in agreement with the experimental data and previous theoretical calculations.Comment: 17 pages, 6 figure

Guanaco hunting strategies in the southeastern Pampas during the late holocene

In this chapter we discuss the strategies used by hunter-gatherers to capture guanaco (Lama guanicoe) in the southeastern Pampas during the Late Holocene (ca. 3500 to 500 14C years BP). We summarize the analysis of different evidence (e.g., mortality and skeletal part profiles, sex structure, weapons systems) obtained from four archaeological sites; three associated with the initial Late Holocene (ca. 3400? 1700 14C years BP; Calera, Nutria Mansa 1, and Empalme Querandíes 1) and one with the final Late Holocene (ca. 1300?800 14C years BP; Hangar). Results indicate that during the initial Late Holocene, the guanaco hunting tactics were focused on family groups and troops of males. At this time, bola stones were more frequently used as thrown weapons. On the other hand, during the final Late Holocene, there is a significant quantity of small triangular projectile points linked with the use of bow and arrow, indicating a change in the Pampas weapon systems. The landscape geomorphology in which some of the archaeological sites are located allows us to suggest the use of active traps during the Late Holocene. River junctions and dune ridges were places where it would have been possible to enclose the principal prey of pre-Hispanic indigenous populations that inhabited the Pampas for millennia.Fil: Kaufmann, Cristian Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Alvarez, María Clara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Messineo, Pablo Geronimo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Barros, Maria Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano. Universidad Nacional del Centro de la Provincia de Buenos Aires. Investigaciones Arqueológicas y Paleontológicas del Cuaternario Pampeano; ArgentinaFil: Bonomo, Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Heider, Guillermo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Departamento de Geología; Argentin

Renal Hypoxia and Dysoxia After Reperfusion of the Ischemic Kidney

Ischemia is the most common cause of acute renal failure. Ischemic-induced renal tissue hypoxia is thought to be a major component in the development of acute renal failure in promoting the initial tubular damage. Renal oxygenation originates from a balance between oxygen supply and consumption. Recent investigations have provided new insights into alterations in oxygenation pathways in the ischemic kidney. These findings have identified a central role of microvascular dysfunction related to an imbalance between vasoconstrictors and vasodilators, endothelial damage and endothelium–leukocyte interactions, leading to decreased renal oxygen supply. Reduced microcirculatory oxygen supply may be associated with altered cellular oxygen consumption (dysoxia), because of mitochondrial dysfunction and activity of alternative oxygen-consuming pathways. Alterations in oxygen utilization and/or supply might therefore contribute to the occurrence of organ dysfunction. This view places oxygen pathways’ alterations as a potential central player in the pathogenesis of acute kidney injury. Both in regulation of oxygen supply and consumption, nitric oxide seems to play a pivotal role. Furthermore, recent studies suggest that, following acute ischemic renal injury, persistent tissue hypoxia contributes to the development of chronic renal dysfunction. Adaptative mechanisms to renal hypoxia may be ineffective in more severe cases and lead to the development of chronic renal failure following ischemia-reperfusion. This paper is aimed at reviewing the current insights into oxygen transport pathways, from oxygen supply to oxygen consumption in the kidney and from the adaptation mechanisms to renal hypoxia. Their role in the development of ischemia-induced renal damage and ischemic acute renal failure are discussed

Safe prescribing of non-steroidal anti-inflammatory drugs in patients with osteoarthritis--an expert consensus addressing benefits as well as gastrointestinal and cardiovascular risks

BACKGROUND: There are several guidelines addressing the issues around the use of NSAIDs. However, none has specifically addressed the upper versus lower gastrointestinal (GI) risk of COX-2 selective and non-selective compounds nor the interaction at both the GI and cardiovascular (CV) level of either class of drugs with low-dose aspirin. This Consensus paper aims to develop statements and guidance devoted to these specific issues through a review of current evidence by a multidisciplinary group of experts. METHODS: A modified Delphi consensus process was adopted to determine the level of agreement with each statement and to determine the level of agreement with the strength of evidence to be assigned to the statement. RESULTS: For patients with both low GI and CV risks, any non-selective NSAID (ns-NSAID) alone may be acceptable. For those with low GI and high CV risk, naproxen may be preferred because of its potential lower CV risk compared with other ns-NSAIDs or COX-2 selective inhibitors, but celecoxib at the lowest approved dose (200 mg once daily) may be acceptable. In patients with high GI risk, if CV risk is low, a COX-2 selective inhibitor alone or ns-NSAID with a proton pump inhibitor appears to offer similar protection from upper GI events. However, only celecoxib will reduce mucosal harm throughout the entire GI tract. When both GI and CV risks are high, the optimal strategy is to avoid NSAID therapy, if at all possible. CONCLUSIONS: Time is now ripe for offering patients with osteoarthritis the safest and most cost-effective therapeutic option, thus preventing serious adverse events which could have important quality of life and resource use implications. Please see related article: http://dx.doi.org/10.1186/s12916-015-0291-x