Removal of Cr(VI) from Waters by Multi-Walled Carbon Nanotubes: Optimization and Kinetic Investigations

The adsorption of chromium(VI) from aqueous solutions onto multi-walled carbon nanotubes (MWCNTs) has been investigated under various experimental conditions of initial metal concentration, agitation speed, aqueous pH, temperature and adsorbent dosage to assess the equilibrium and kinetic parameters. It was found that the kinetic data were fitted with the pseudo-first- and pseudo-second-order models, whereas the chromium(VI) adsorption data were fitted with the Langmuir and Freundlich equilibrium models to give the characteristic parameters of each model. According with the evaluation, both isotherm models are useful to represent the measured adsorption data. The adsorption of chromium(VI) is also dependent on the temperature, and the corresponding thermodynamic parameters including ΔH°, ΔG° and ΔS° were estimated from the experimental data, indicating the exothermic and non-spontaneous nature of the metal adsorption onto the MWCNTs. Chromium(VI) desorption was investigated by the use of aqueous hydrazine sulfate solutions

Semiconductor Materials by Ultrasonic Spray Pyrolysis and Their Application in Electronic Devices

Ultrasonic spray pyrolysis is a deposition technique that enables a fine mist of the precursor solution in order to deposit higher-density thin films. This characteristic makes of great potential the use of ultrasonically spray-deposited semiconductors films for low-cost, transparent, flexible and large-area applications. In this chapter, low-temperature deposition and characterization of ultrasonically spray-deposited zinc oxide (ZnO) films are presented. The ZnO films deposited by ultrasonic spray pyrolysis at 200°C were characterized by optical transmittance, photoluminescence spectroscopy, X-ray diffraction and Fourier transform infrared spectroscopy. The study of low-temperature annealing of ZnO films is also presented. Moreover, the characterization of aluminum-doped ZnO films deposited by ultrasonic spray pyrolysis at 200°C is presented. Finally, applications of these ultrasonic spray-deposited films in electronic devices are presented

The first steps of iodine gas-to-particle conversion as seen in the lab: constraints on the role of iodine oxides and oxyacids

&amp;lt;p&amp;gt;The photooxidation of gas phase iodine-bearing molecules emitted by marine biota leads to intense particle nucleation events in the coastal and polar marine boundary layer&amp;lt;sup&amp;gt;1-3&amp;lt;/sup&amp;gt;. The ubiquity of iodine in the marine atmospheric environment&amp;lt;sup&amp;gt;4-7&amp;lt;/sup&amp;gt; has suggested that this may be a previously unrecognized global source of new aerosol particles&amp;lt;sup&amp;gt;8&amp;lt;/sup&amp;gt;. Atmospheric modeling is required in order to evaluate the importance of this process, but a substantial lack of understanding of the gas-to-particle conversion mechanism is hindering this effort, especially regarding the gas phase chemistry of the nucleating molecules (iodine oxides&amp;lt;sup&amp;gt;9&amp;lt;/sup&amp;gt;&amp;lt;sup&amp;gt;,&amp;lt;/sup&amp;gt;&amp;lt;sup&amp;gt;10&amp;lt;/sup&amp;gt; and/or oxyacids&amp;lt;sup&amp;gt;7&amp;lt;/sup&amp;gt;) and the formation kinetics of molecular clusters. To address this problem, we have conducted new flow tube laboratory experiments where pulsed laser photolysis or continuous broad-band photolysis of I&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;/O&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; mixtures&amp;amp;#160; in air are used to generate iodine radicals in the presence of atmospherically representative mixing ratios of water vapor. The molecular reactants and the resulting molecular products are detected by time-resolved VUV laser photo-ionization time-of-flight mass spectrometry. High-level quantum chemistry and master equation calculations and gas kinetics modelling are used to analyse the experimental data. In this presentation we discuss our results and their implications for the interpretation of field meassurements and for the implementatiion of an iodine oxide particle formation mechanism in atmospheric models.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;References:&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;1. Hoffmann, T., O'Dowd, C. D. &amp;amp; Seinfeld, J. H. Iodine oxide homogeneous nucleation: An explanation for coastal new particle production. Geophys. Res. Lett. &amp;lt;strong&amp;gt;28&amp;lt;/strong&amp;gt;, 1949-1952 (2001).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;2. McFiggans, G. et al. Direct evidence for coastal iodine particles from Laminaria macroalgae - linkage to emissions of molecular iodine. Atmos. Chem. Phys. &amp;lt;strong&amp;gt;4&amp;lt;/strong&amp;gt;, 701-713 (2004).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;3. O'Dowd, C. D. et al. Marine aerosol formation from biogenic iodine emissions. Nature &amp;lt;strong&amp;gt;417&amp;lt;/strong&amp;gt;, 632-636 (2002).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;4. Prados-Roman, C. et al. Iodine oxide in the global marine boundary layer. Atmos. Chem. Phys. &amp;lt;strong&amp;gt;15&amp;lt;/strong&amp;gt;, 583-593, doi:10.5194/acp-15-583-2015 (2015).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;5. Sch&amp;amp;#246;nhardt, A. et al. Simultaneous satellite observations of IO and BrO over Antarctica. Atmos. Chem. Phys. &amp;lt;strong&amp;gt;12&amp;lt;/strong&amp;gt;, 6565-6580, doi:10.5194/acp-12-6565-2012 (2012).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;6. Mahajan, A. S. et al. Concurrent observations of atomic iodine, molecular iodine and ultrafine particles in a coastal environment. Atmos. Chem. Phys. &amp;lt;strong&amp;gt;10&amp;lt;/strong&amp;gt;, 27227-27253 (2010).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;7. Sipil&amp;amp;#228;, M. et al. Molecular-scale evidence of aerosol particle formation via sequential addition of HIO3. Nature &amp;lt;strong&amp;gt;537&amp;lt;/strong&amp;gt;, 532-534, doi:10.1038/nature19314 (2016).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;8. Saiz-Lopez, A. et al. Atmospheric Chemistry of Iodine. Chem. Rev. &amp;lt;strong&amp;gt;112&amp;lt;/strong&amp;gt;, 1773&amp;amp;#8211;1804, doi:DOI: 10.1021/cr200029u (2012).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;9. G&amp;amp;#243;mez Mart&amp;amp;#237;n, J. C. et al. On the mechanism of iodine oxide particle formation. Phys. Chem. Chem. Phys. &amp;lt;strong&amp;gt;15&amp;lt;/strong&amp;gt;, 15612-15622, doi:10.1039/c3cp51217g (2013).&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;10. Saunders, R. W., Mahajan, A. S., G&amp;amp;#243;mez Mart&amp;amp;#237;n, J. C., Kumar, R. &amp;amp; Plane, J. M. C. Studies of the Formation and Growth of Aerosol from Molecular Iodine Precursor. Z. Phys. Chem. &amp;lt;strong&amp;gt;224&amp;lt;/strong&amp;gt;, 1095-1117 (2010).&amp;lt;/p&amp;gt; </jats:p

Análisis bibliométrico de la producción científica peruana en cardiología y medicina cardiovascular

Objective. To determine the characteristics and trend of the articles published on cardiology and cardiovascular medicine in the Peruvian context, and to understand how it has changed over the years. Materials and methods. A bibliometric study of original articles published up to 2020 by Peruvian authors in journals indexed under the category “Cardiac &amp; Cardiovascular Systems” in Web of Science (WOS) was performed. The articles were included according to the selection criteria in the Rayyan web application and the bibliometric analysis was performed using the Bibliometrix package in the R programming language and VOSviewer. Results. A total of 159 published articles were included, and an increase in the number of publications since 2015 was observed. The most cited article was a clinical trial by Fitchett et al. and published in 2016. Miranda JJ was the Peruvian author with the highest number of published articles followed by Hernández AV and Málaga G. The institutional affiliation with the highest number of original articles was Universidad Peruana Cayetano Heredia. Regarding the terms or keywords, it was found that most of the published studies had terms related to epidemiology, while in the most recent articles, the terms were related to outcomes or specific interventions that are used in clinical studies. Conclusions. In the last five years, there has been an increase in the scientific production on cardiology and cardiovascular medicine by authors with Peruvian institutional affiliation, with a greater production from the Universidad Peruana Cayetano Heredia. The journal with the highest number of publications by authors with Peruvian institutional affiliation on cardiology and cardiovascular medicine was Circulation, where two of the most cited articles with Peruvian institutional affiliation were also found.Objetivo. Determinar las características y la tendencia de los artículos publicados sobre cardiología y medicina cardiovascular en el contexto peruano, y comprender cómo ha cambiado a lo largo de los años. Materiales y métodos. Se realizó un estudio bibliométrico de artículos originales publicados hasta el año 2020 por autores peruanos en revistas indexadas bajo la categoría «Cardiac &amp; Cardiovascular Systems» en Web of Science (WOS). Se incluyeron los artículos según los criterios de selección en el aplicativo web Rayyan y se realizó el análisis bibliométrico mediante el paquete Bibliometrix en el lenguaje de programación R y VOSviewer. Resultados. Se incluyeron 159 artículos publicados, y se observó un incremento del número de publicaciones desde 2015. El artículo más citado fue un ensayo clínico realizado por Fitchett et al. y publicado en 2016. Miranda JJ fue el autor peruano con mayor número artículos publicados seguido de Hernández AV y Málaga G. La filiación institucional con mayor número de artículos originales fue la Universidad Peruana Cayetano Heredia. En cuanto a los términos o palabras clave, se encontró que la mayor cantidad de estudios publicados contaban con términos relacionados con la epidemiología, mientras que en los artículos más recientes, los términos se relacionaron con desenlaces o intervenciones específicas que son utilizados en estudios clínicos. Conclusiones. Se encontró un incremento en los últimos cinco años en la producción científica sobre cardiología y medicina cardiovascular de autores con filiación institucional peruana, con una mayor producción de la Universidad Peruana Cayetano Heredia. La revista con mayores publicaciones de autores con filiación institucional peruana sobre cardiología y medicina cardiovascular fue Circulation, donde también se encontraron dos de los artículos con filiación institucional peruana más citados

Update on obesity and obesity paradox in heart failure

Obesity has reached epidemic proportions in most of the Westernized world. Overweightness and obesity adversely impact cardiac structure and function, including on both the right and, especially, left sides of the heart, with adverse affects on systolic and, especially, diastolic ventricular function. Therefore, it is not surprising that obesity markedly increases the prevalence of heart failure (HF). Nevertheless, many studies have documented an obesity paradox in large cohorts with HF, where overweight and obese have a better prognosis, at least in the short-term, compared with lean HF patients. Although weight loss clearly improves cardiac structure and function and reduces symptoms in HF, there are no large studies on the impact of weight loss on clinical events in HF, preventing definitive guidelines on optimal body composition in patients with HF

New Insights into Martian Atmospheric Chemistry

HO_x radicals are produced in the Martian atmosphere by the photolysis of water vapor and subsequently participate in catalytic cycles that recycle carbon dioxide (CO_2) from its photolysis product carbon monoxide (CO), providing a qualitative explanation for the stability of its atmosphere. Balancing CO_2 production and loss based on our current understanding of Martian gas-phase chemistry has, however, proven to be difficult. The photolysis of O_3 produces O(^1D), while oxidation of CO produces HOCO radicals, a new member of the HO_x family. The O(^1D) quantum yield has recently been updated, which quantifies nonzero quantum yields in the Huggins bands. In Earth’s atmosphere HOCO is considered to be unimportant since it is quickly removed by abundant oxygen molecules. The smaller amount of O_2 in the Mars’ atmosphere causes HOCO’s lifetime to be longer in Mars’ atmosphere than Earth’s (3 × 10^(-5) seconds to 1.2 days from Mars’s surface to 240 km, respectively). Limited kinetic data on reactions involving HOCO prevented consideration of its reactions directly in atmospheric models. Therefore, the impact of HOCO reactions on Martian chemistry is currently unknown. Here, we incorporate new literature rate constants for HOCO chemistry and an updated representation of the O(^1D) quantum yield in the Caltech/JPL 1-D photochemical model for Mars’ atmosphere. Our simulations exemplify perturbations to NO_y, HO_x, and CO_x species, ranging from 5 to 50%. The modified O(^1D) quantum yield and new HOCO chemistry cause a 10% decrease and a 50% increase in OH and H_2O_2 total column abundances, respectively. At low altitudes, HOCO production contributes 5% towards CO_2 production. Given recent experimentally-obtained branching ratios for the oxidation of CO, HOCO may contribute up to 70% toward the production of NO_y, where HO_x and NO_y species are enhanced up to a factor 3, which has implications for rethinking the fundamental understanding of NO_y, HO_x, and CO/CO_2 cycling on Mars. Two new reaction mechanisms for converting CO to CO_2 using HOCO reactions are proposed, which reveal that H_2O_2 is more intimately coupled to CO_x chemistry. Our simulations are in good agreement with satellite/spacecraft measurements of CO and H_2O_2 on Mars

Route Towards a Label-free Optical Waveguide Sensing Platform Based on Lossy Mode Resonances

According to recent market studies of the North American company Allied Market Research, the field of photonic sensors is an emerging strategic field for the following years and it is expected to garner $18 billion by 2021. The integration of micro and nanofabrication technologies in the field of sensors has allowed the development of new technological concepts such as lab-on-a-chip, which have achieved extraordinary advances in terms of detection and applicability, for example in the field of biosensors. This continuous development has allowed that equipment consisting of many complex devices that occupied a whole room a few years ago, at present it is possible to handle them in the palm of the hand; that formerly long duration processes are carried out in a matter of milliseconds and that a technology previously dedicated solely to military or scientific uses is available to the vast majority of consumers. The adequate combination of micro and nanostructured coatings with optical fiber sensors has permitted us to develop novel sensing technologies, such as the first experimental demonstration of lossy mode resonances (LMRs) for sensing applications, with more than one hundred citations and related publications in high rank journals and top conferences. In fact, fiber optic LMR-based devices have been proven as devices with one of the highest sensitivity for refractometric applications. Refractive index sensitivity is an indirect and simple indicator of how sensitive the device is to chemical and biological species, topic where this proposal is focused. Consequently, the utilization of these devices for chemical and biosensing applications is a clear opportunity that could open novel and interesting research lines and applications as well as simplify current analytical methodologies. As a result, on the basis of our previous experience with LMR based sensors to attain very high sensitivities, the objective of this paper is presenting the route for the development of label-free optical waveguide sensing platform based on LMRs that enable to explore the limits of this technology for bio-chemosensing applications

Geographical variations in the risk of adverse birth outcomes in Spain

The objective of this study was to describe the spatial risk-patterns of prematurity and low birth weight in Spain. A descriptive spatial analysis of births registered in the Spanish Vital Statistics during 2004–2008 using municipalities as the observation unit was carried out. Besag-York-Mollié autoregressive spatial models were adjusted using the Integrated Nested Laplace approximation to calculate relative risks and posterior probabilities of having very and moderate preterm or low weight newborns. Results were represented in maps to assess geographic risk-patterns. Spatial analysis shows geographical variations in the risk of adverse reproductive outcomes in Spain highlighting three main high-risk zones, namely, municipalities in Asturias, Madrid City and Murcia. The specific risk patterns identified on each zone suggests some differences regarding the potential underlying risk factors and specific areas for future research. A differential exposure during pregnancy to some risks potentially related to industry or agriculture and other contextual factors could underlie an unequal vulnerability to adverse reproductive outcomes in some Spanish regions.Fondo de Investigación Sanitaria (PI081330); Spanish Ministry of Science and Innovation (SEJ 2005/07679); CIBER en Epidemiología y Salud Pública (CIBERESP), Spain.S

Late myocardial reperfusion in ST-elevation myocardial infarction: Protocol for a systematic review and meta-analysis

Introduction ST-segment elevation myocardial infarction (STEMI) is the most severe clinical form of acute myocardial infarction, for which the current treatment consists of effective and timely myocardial reperfusion (within 12 hours of symptom onset). However, between 10% and 15% of patients with STEMI arrive at hospital facilities 12 hours after the onset of symptoms (late presentation). Therefore, the objective of the present study will be to determine if late revascularisation (12-72 hours after the onset of symptoms) affects the indicators of cardiovascular mortality, reinfarction, recurrent infarction, hospitalisation for heart failure and post infarction angina compared with no late revascularisation in patients with STEMI. Methods and analysis A systematic literature search of PubMed, The Cochrane Library, Embase, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Web of Science, Scopus and Global Health will be conducted. Publications in English, Portuguese or Spanish that report the clinical results of primary percutaneous revascularisation (primary PCI) in adult patients with STEMI 12-72 hours after the onset of symptoms will be included. Studies with participants with a diagnosis other than STEMI or patients with STEMI of >12 hours complicated by heart failure, cardiogenic shock or ventricular arrhythmias, and studies of combined interventions (pharmacoinvasive strategy) were excluded. Two independent authors will identify the relevant publications, and discrepancies will be adjudicated by a third author. Data extraction will be performed by two independent authors and verified by a third author. Risk of bias of studies will be assessed using the Cochrane risk of bias' tool (RoB 2) or Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool. If appropriate, a meta-analysis will be performed in order to examine the effect of late revascularisation in clinical outcomes of interest. Ethics and discussion This study will use published data only, thus, ethical approval will not be required. The results will be disseminated through peer-reviewed publication and conference presentations. PROSPERO registration number CRD42021283429.Revisión por pare