Nivel de mercurio en cabello de ninos peruanos expuestos en una zona minera de Arequipa y de la ciudad de Lima

Objetivo: El propósito del estudio fue comparar los niveles de mercurio en cabello en dos muestras de ninos peruanos provenientes de dos zonas geográficas distintas: una zona rural minera y una zona urbana. Material y métodos: La zona minera correspondió al poblado de Mollehuaca (Arequipa), de donde se obtuvieron 52 muestras de cabello; la zona urbana no expuesta a minería correspondió al distrito de Los Olivos (Lima), de donde se obtuvieron 40 muestras. Se determinó el nivel de mercurio con la técnica estandarizada de plasma de inducción acoplado con un espectrómetro de masas (ICP-MS). Resultados: En la zona rural, en promedio, se obtuvo un nivel de mercurio de 7,47 ppb±26,9. En la zona urbana, el nivel de mercurio alcanzó un promedio de 2,47 ppb±1,28. No se encontraron diferencias significatives en el nivel de mercurio según edad o género. Conclusión: Se concluye que el grupo expuesto a minería aurífera informal y de zona rural presentó niveles de mercurio en cabello en promedio mayores a los del grupo de zona urbana, pero esta diferencia no fue significativa (p=0,188, α=0,05)

The photophysics of nitrocarbazoles studied by using spectroscopic, photoacoustic and luminescence techniques

The photophysical behaviour of 1-nitrocarbazol and 3-nitrocarbazol in different organic solvents has been studied by using spectroscopic, luminescence and photoacoustic techniques. Absorption spectra and triplet state transient spectra were recorded and formation quantum yields and lifetimes determined. Phosphorescence emission at 77 K and laser induced luminescence in acetonitrile solution at 298 K for the nitrocarbazoles were studied. Results are discussed in terms of the optimized structure of 1 -nitrocarbazole and 3-nitrocarbazole and compared with that of carbazole. The nitro group attached to the carbazole moiety induces important changes in the photophysical behavior of those compounds.Facultad de Ciencias Exacta

The photophysics of nitrocarbazoles studied by using spectroscopic, photoacoustic and luminescence techniques

The photophysical behaviour of 1-nitrocarbazol and 3-nitrocarbazol in different organic solvents has been studied by using spectroscopic, luminescence and photoacoustic techniques. Absorption spectra and triplet state transient spectra were recorded and formation quantum yields and lifetimes determined. Phosphorescence emission at 77 K and laser induced luminescence in acetonitrile solution at 298 K for the nitrocarbazoles were studied. Results are discussed in terms of the optimized structure of 1 -nitrocarbazole and 3-nitrocarbazole and compared with that of carbazole. The nitro group attached to the carbazole moiety induces important changes in the photophysical behavior of those compounds.Facultad de Ciencias Exacta

“Education Network” a new way to teach Chemistry

The complexity of chemistry has implications for the teaching of chemistry. That chemistry is a very complex subject. The majority of the students at University think that chemistry is a difficult discipline and they have difficulty in understanding the concepts. Moreover, students' interest in chemistry decreases the first year at university. The reason for this decrease might be that the contents of chemistry laboratory classes are boring, out of date and lacking of dynamism that students experience through visual media tools. For these reasons, new programs and methodologies should be developed. Those are based on making chemistry relevant through problem solving and collaborative learning hold promise for reforming chemistry education. It is about an education according to circumstances, which is adapted to context and virtual behaviour of people. It's time to CRUSH boredom by transforming your classroom into an Escape Room adventure. School-based escape games are a great teaching tool. The students while playing, learn. The most important point is that they won’t realize they’re doing both at the same time. In this work, an educational gamification experience based on the escape room concept was developed. The first (Do It Yourself) DIY Escape Room was built the year before at Mechanical Engineer Degree started, that took more than three weeks of work. It was presented to other professors to the same subject at different degrees. That DIY Escape Room was modified and adapted to each group. Each professor changed the clues, problems and so on in order to orientate the topic as much as possible to their students.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Uterine sarcomas: clinical practice guidelines for diagnosis, treatment, and follow-up, by Spanish group for research on sarcomas (GEIS)

Adenosarcoma; Guidelines; Uterine sarcomaAdenosarcoma; Pautas; Sarcoma uterinoAdenosarcoma; Pautes; Sarcoma uteríUterine sarcomas are very infrequent and heterogeneous entities. Due to its rarity, pathological diagnosis, surgical management, and systemic treatment are challenging. Treatment decision process in these tumors should be taken in a multidisciplinary tumor board. Available evidence is low and, in many cases, based on case series or clinical trials in which these tumors have been included with other soft tissue sarcoma. In these guidelines, we have tried to summarize the most relevant evidence in the diagnosis, staging, pathological disparities, surgical management, systemic treatment, and follow-up of uterine sarcomas

Treatment of olive oil mill wastewater by single electrocoagulationwith different electrodes and sequentialelectrocoagulation/electrochemical Fenton-based processes

The treatment of olive oil mill wastewater (OOMW) by novel sequential processes involving electrocoagulation (EC) followed by electro-Fenton (EF) or photoelectro-Fenton (PEF) under UVA irradiation has been studied using a boron-doped diamond anode and an air-diffusion cathode for H2O2 electrogeneration. Their performance was monitored from the removal of total organic carbon (TOC), chemical oxygen demand, turbidity, total solids and total nitrogen, as well as from the energy consumption. Preliminary EC assays were performed with one pair of electrodes made of Al, Fe, AISI 304 or AISI 316L. The Fe/Fe cell showed the best performance, yielding 40% TOC decay in 20 min. Subsequent EF or PEF at natural pH 7.2 performed similarly, whereas PEF became superior at pH 3.0 due to the action of UVA photons. Comparison between EC/PEF and single EF or PEF at pH 3.0 and 25 mA cm-2 with 0.50 mM Fe2+ revealed the positive outcome of the sequential process, attaining 97.1% TOC abatement after 600 min. GC-MS analysis of the raw wastewater allowed identifying 18 cyclic and 27 aliphatic compounds, most of which could not be removed by EC. The final solutions in EC/EF and EC/PEF contained a large plethora of persistent long-chain aliphatic acids and alkanes

The photophysics of nitrocarbazoles studied by using spectroscopic, photoacoustic and luminescence techniques

The photophysical behaviour of 1-nitrocarbazol and 3-nitrocarbazol in different organic solvents has been studied by using spectroscopic, luminescence and photoacoustic techniques. Absorption spectra and triplet state transient spectra were recorded and formation quantum yields and lifetimes determined. Phosphorescence emission at 77 K and laser induced luminescence in acetonitrile solution at 298 K for the nitrocarbazoles were studied. Results are discussed in terms of the optimized structure of 1 -nitrocarbazole and 3-nitrocarbazole and compared with that of carbazole. The nitro group attached to the carbazole moiety induces important changes in the photophysical behavior of those compounds.Facultad de Ciencias Exacta

Selective Fractionation And Isolation Of Allelopathic Compounds From Helianthus Annuus L. Leaves By Means Of High-Pressure Techniques

The allelopathic potential of Helianthus annuus L. leaves was study based on bio-directed chemical fractionation approach. Aerial parts of H. annuus were extracted by means of SFE using supercritical carbon dioxide (scCO2) and ESE using CO2+50% EtOH/H2O (varying ethanol in water from 0 to 100%). Extractions were carried out at 400 bar, 55 °C, 20 g/min and for 4 h. Then, extracts were fractionated in three separators at the following conditions: S1: 200 bar/45 °C; S2: 90 bar/40 °C; and S3: 1 atm/30 °C. ESE obtained higher overall yields than scCO2 and the use of water as cosolvent (CO2+50% H2O) resulted in a S3 fraction free from chlorophylls and rich in bioactive compounds. 14 compounds, including fatty acids, terpenes, flavonoids and heliannuols, were isolated from this fraction. After performing the bioassay on pure compounds, heliannuol D, tambulin, pinoresinol and sesquiterpene 10-oxo-isodauc-3-en-15-al showed the most effective inhibitor profiles

Manganese Defective Clustering: Influence on the Spectroscopic Features of Ceria-Based Nanomaterials

The influence of manganese modification on the spectroscopic features of manganese-doped CeO2 systems synthesized by the microwave-assisted hydrothermal route and their correlation with the presence of O defective structures were verified, focusing on their interaction with poisonous atmospheres. Raman and electron paramagnetic resonance studies confirmed the presence of defective clusters formed by dipoles and/or quadrupoles. The number of paramagnetic species was found to be inversely proportional to the doping concentration, resulting in an increase in the Mn2+ signal, likely due to the reduction of Mn3+ species after the interaction with CO. X-ray photoelectron spectroscopy data showed the pure system with 33% of its cerium species in the Ce3+ configuration, with an abrupt decrease to 19%, after the first modification with Mn, suggesting that 14% of the Ce3+ species are donating one electron to the Mn2+ ions, thus becoming nonparamagnetic Ce4+ species. On the contrary, 58% of the manganese species remain in the Mn2+ configuration with five unpaired electrons, corroborating the paramagnetic feature of the samples seen in the electron paramagnetic resonance study