Synthesis and characterization of a new nanosorbent based on functionalized magnetic nanoparticles and its use in the determination of mercury by FI-CV-ETAAS

In this work, a new chelating sorbent which employs 1,5-bis(di-2-pyridil)methylene thiocarbohydrazide as the functional group and magnetic nanoparticles (MNPs) as its support (DPTH-MNP) was synthetized and characterized. The MNPs were prepared by coprecipitation of Fe+2 and Fe+3 with NH3 and then coated with silica in order to easily bind the support and the functionalizing molecule. The aim of the synthesis of this material is applying it as a solid-phase extracting agent and evaluating its potential for the extraction and pre-concentration of trace amounts of analytes present in biological and environmental samples with on-line methods. The MNPs’ magnetic core would allow overcoming the usual backpressure problems that happen in solid-phase extraction methods thanks to the possibility of immobilizing the MNPs by applying an external magnetic field. From the study of its adsorption capacity toward metal ions, mercury and antimony were the most retained. Thus, a flow injection solid phase extraction and cold vapor generation method for mercury determination based on the use of this new chelating nanosorbent was optimized. The greatest efforts were put into the reactor design to minimize compaction and loss of nanosorbent. The knotted reactor shown in Figure 1 was chosen as the best. Then, chemical and flow variables were optimized by Central composite designs (CCDs). The method developed has showed to be useful for the automatic pre-concentration and determination of mercury in environmental and biological samples. The determination was performed using electrothermal atomic absorption spectrometry (ETAAS). Under the optimum conditions, pH 5 and 120 s preconcentration time, the enrichment factor was 5.33; the detection limit (3σ) was 7.8 ng L-1; the determination limit (10σ) was 99 ng L-1; and the precisions (calculated for 10 replicate determinations at a 1 and 5 µg L-1 standards) were 1.7 and 1.9 % (RSD), respectively. Two linear calibration graphs were obtained, from the determination limits to 10 µg L-1 and from 10 to at least 50 µg L-1. From the comparison with other similar methods found in the bibliography, the detection limit and precisions calculated with our method were better. In order to evaluate the accurate and applicability of the method, the analysis of five certified samples LGC 6016 estuarine water, TMDA 54.4 fortified lake water, SRM 2976 mussel tissue, TORT-1 lobster hepatopancreas and DOLT-1 dogfish liver by standard addition and external calibration, were addressed. The results showed good agreement between the certified values, or added amounts of mercury, and the found concentrations. The method was successfully applied to the determination of mercury in sea-water samples collected in the Málaga Bay.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Archivo color-rostro. La sinestesia como motor del proceso creativo.

[ES] Archivo color-rostro. La sinestesia como motor del proceso creativo es un proyecto artístico de carácter teórico-práctico que surge de la necesidad de investigar y conocer más sobre la sinestesia. Por otra parte, este proyecto también nace de la necesidad de crear un archivo donde quede el registro de mis propios instantes de experimentación de la sinestesia, en concreto la del tipo color-rostro. Este Trabajo Final de Grado se realiza con el propósito de profundizar en la condición particular de sinésteta, poco conocida a nivel personal hasta el momento, haciendo visible este fenómeno mediante la creación de una instalación artística. La creación de este archivo autobiográfico, que toma como eje la sinestesia color-rostro, se ha organizado teniendo presentes las tres fases de todo proceso archivístico: recolectar, clasificar y almacenar. La investigación realizada se ha orientado a conocer con mayor detalle el fenómeno de la sinestesia y el arte del archivo. Todo ello converge en una obra instalativa final donde se muestra la convivencia personal con el fenómeno de la sinestesia color-rostro.[EN] Face-color archive. Synesthesia as the engine of the creative process is an artistic project of a theoretical-practical nature that arises from the need to investigate and learn more about synesthesia. On the other hand, this project was also born from the need to create my own archive where the record of my own moments of experimentation with synesthesia remains, specifically the color-face type. This Final Degree Project is carried out with the purpose of delving into the particular condition of synaestheta, little known on a personal level until now, making this phenomenon visible through the creation of an artistic installation. In the creation of this autobiographical archive, that takes color-face synesthesia as its axis, it has been organized keeping in mind the three phases of any archival process: collecting, classifying and storing. The research carried out has been aimed at knowing in greater detail the phenomenon of synesthesia and the art of the archive. All this converges in a final installation work where personal coexistence with the phenomenon of color-face synesthesia is shown.Alonso Suñer, IM. (2021). Archivo color-rostro. La sinestesia como motor del proceso creativo. Universitat Politècnica de València. http://hdl.handle.net/10251/170049TFG

Livestock grazing impact differently on the functional diversity of dung beetles depending on the regional context in subtropical forests

The replacement of native forest by cattle pastures reduces functional diversity; however, little is known about whether the changes depend on regional variation. Dung beetles are one of the most diverse and functionally important taxa; through organic matter burial, dung beetles improve soil quality. We collected dung beetles in native forests and cattle ranching areas in subtropical forests with contrasting climatic conditions: the Atlantic Forest, the Humid Chaco, and the Dry Chaco. We measured 11 traits related to the ecology and the physiology of species. Irrespectively of the region, functional richness was higher in forests (native and with cattle) when compared to open pastures. Humid forests (Atlantic Forest and Humid Chaco) showed higher functional richness than Dry Chaco. Functional dispersion in humid forests was similar between native forest and livestock systems, however, functional dispersion in the Dry Chaco was higher in open pastures compared to native forest. According to our results, native forests and forests with cattle maintain functional diversity in all regions. However, in the case of open pastures, the response depends on the regional context; the replacement of native forest by open pastures strongly affected functional diversity in humid forests and showed less impact on dry forest.Fil: Guerra Alonso, Celeste Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Zurita, Gustavo Andres. Universidad Nacional de Misiones. Facultad de Ciencias Forestales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Bellocq, Maria Isabel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; Argentin

Senegalese sole (Solea senegalensis) ISG15: molecular characterization and in vivo interplay with viral infections

The interferon-stimulated gene 15 (Isg15) is strongly induced by type I interferon (IFN I), viral infection, and double-stranded RNA (poly I:C) in several fish species, suggesting that Isg15 protein could play a key role in fish innate immunity against viral diseases. Thus, the aim of the present study was to characterize the molecular structure and transcription pattern of the Senegalese sole (Solea senegalensis) Isg15 gene in response to viral infections. The molecular characterization shows that the Senegalese sole Isg15 gene codes for a typical Isg15 protein of 165 aa, containing two ubiquitin-like domains and one conserved LRLRGG conjugating motif at the C-terminal end. The untranslated 5´-end region exhibited the structure of an IFN-stimulated gene promoter, with two interferon stimulated response elements (ISRE). Pairwise alignments based on deduced amino acid sequences showed homologous relationships (72.5-74.2%) between the Isg15 of Senegalese sole and other pleuronectiforms. The Isg15 transcription has been studied in head kidneys of Senegalese sole inoculated with poly I:C and with different fish viruses: two Viral Haemorrhagic Septicaemia Virus (VHSV) isolates (highly pathogenic and non-pathogenic to sole), and one reassortant Viral Nervous Necrosis Virus (VNNV) isolate, composed of a RGNNV-type RNA1 and a SJNNV-type RNA2 (pathogenic to sole). These challenges showed that poly I:C induces Isg15 transcription from 3 to 72 h post-injection (p.i.), whereas the induction in response to viral infections started at 24-48 h p.i. The fast induction of Isg15 indicates the potential implication of this ISG in the antiviral state stablished by the IFN I system. On the other hand, the interaction between each virus and the IFN I system was evaluated in fish inoculated with poly I:C and subsequently (24 h later) challenged with the different viruses. This challenge showed a viral multiplication decrease in poly I:C treated animals compared with untreated fish. Besides, results showed that only both pathogenic isolates interfered negatively with the Isg15 stimulation triggered by poly I:C. These results suggest that the Isg15 might play an important role in host defense against RNA virus infection, and the pathogenic isolates used in this study may have mechanisms to evade or limit the Senegalese sole innate host defenses.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Dung beetles response to livestock management in three different regional contexts

The response of biological communities to human disturbances depends on factors acting at local and regional scale and on the interaction between them. We compared the response of native forest dung beetle communities to cattle grazing under regional contexts differing on precipitation patterns (Atlantic forest and humid and dry Chaco). Through multivariate and GLMM analyses we contrasted richness and composition across regions and land uses and explored the role of local and regional variables accounting for those changes. We captured a total of 44101 individuals of 109 species. The interaction between local and regional variables influenced the response to livestock management. In the two wet regions (humid Chaco and Atlantic forest) diversity was similar in the native forest regardless of cattle presence but differs strongly in open pastures. In contrast, in the dry Chaco, differences between native forest and land use were not evident. Vegetation structure was a major determinant of species richness, whereas regional climate determined differences in species composition. We concluded that the response of dung beetles to livestock management cannot be generalized for all biomes. In dry ecosystems, dung beetles are probably pre-adapted to environmental conditions imposed by cattle ranching whereas in wet ecosystems the impact of cattle ranching is more significant.Fil: Guerra Alonso, Celeste Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Zurita, Gustavo Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Puerto Iguazú; ArgentinaFil: Bellocq, Maria Isabel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Rapid Magnetic Dispersive solid phase extraction to preconcentration/determination of Cd and Pb in aqueous samples

A new magnetic dispersive solid phase extraction (MDSPE) method and graphite furnace atomic absorption spectrometry (GFAAS) have been combined for the analysis of Cd and Pb in environmental samples. For the preconcentration, a shell structured Fe3O4@graphene oxide nanospheres was synthetized and characterized. The material was suspended in the ionic liquid 1-n-butyl-3-metilimidazolium tetrafluoroborate [BMIM][BF4], the obtained stable colloidal suspension is named ferrofluid. GO presents excellent adsorbent properties for organic species due to the presence of the electronic π system. For this reason, the organic ligand [1,5-bis-(2-dipyridyl) methylene] thiocarbonohydrazide (DPTH) was used in order to form organic complexes of Cd and Pb. Once the DPTH ligand has been added to sample, the ferrofluid was injected and finely dispersed in the sample solution in order to extract the formed chelates. The complete adsorption of the chelates took place within few seconds then, the solid was separated from the solution with the aid of a strong magnet. Cd and Pb ions were desorbed from the material with 1 mL of acid nitric 5% solution and quantified by GFAAS. All experimental and instrumental variables were optimized. The analytical performances of the optimized method were: EF (Enrichment factor): 200 with LODs (detection limit): 0.005 and 0.004 µg L-1 and LOQs (determination limit): 0.017 and 0.013 µg L-1, for Cd and Pb, respectively. The reliability of the developed procedure was tested by relative standard deviation (% RSD), which was found to be < 5%. The accuracy of the proposed method was verified using certified reference materials (SLRS-5, SPS-SW2, and BCR-723) and by determining the analyte content in spiked aqueous samples. Sea waters and tap water samples collected from Málaga (Spain) were also analysed. The determined values were in good agreement with the certified values and the recoveries for the spiked samples were around 100% in all cases.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Reduction of the transverse effective charge of optical phonons in ZnO under pressure

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 96, 231906 (2010) and may be found at https://doi.org/10.1063/1.3447798."From Raman scattering on a-plane wurtzite ZnO crystals we obtained a decreasing splitting between longitudinal and transversal optical phonons with A1 and E1 symmetry as a function of hydrostatic pressure up to 5.5 GPa. Consequently, the transverse effective charge (e∗T) exhibits a strong reduction with increasing pressure, yielding 2.17–14.6×10−3 P/GPa and 2.04–13.7×10−3 P/GPa (in units of the elementary charge) for the A1 and E1 phonons, respectively. We find a clear systematic in the linear pressure coefficient of e∗T with bond polarity for the series of wide-band gap semiconductors SiC, AlN, GaN, and ZnO.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement

Sunscreen-Based Photocages for Topical Drugs: A Photophysical and Photochemical Study of A Diclofenac-Avobenzone Dyad

[EN] Photosensitization by drugs is a problem of increasing importance in modern life. This phenomenon occurs when a chemical substance in the skin is exposed to sunlight. Photosensitizing drugs are reported to cause severe skin dermatitis, and indeed, it is generally advised to avoid sunbathing and to apply sunscreen. In this context, the nonsteroidal anti-inflammatory drug (NSAID) diclofenac is a photosensitive drug, especially when administered in topical form. In this work, efforts have been made to design and study an innovative pro-drug/pro-filter system containing diclofenac and the UVA filter avobenzone in order to develop a safer use of this topical drug. The design is based on the presence of a well-established photoremovable phenacyl group in the avobenzone structure. Steady-state photolysis of the dyad in hydrogen-donor solvents, monitored by UV-Vis spectrophotometry and HPLC, confirms the simultaneous photorelease of diclofenac and avobenzone. Laser flash photolysis and phosphorescence emission experiments allow us to gain insight into the photoactive triplet excited-state properties of the dyad. Finally, it is shown that avobenzone provides partial photoprotection to diclofenac from photocyclization to carbazole derivatives.The present work was supported by the Spanish Government (CTQ2015-70164-P, BES-2013-066566), Generalitat Valenciana (Prometeo/2017/075).Aparici-Espert, MI.; Miranda Alonso, MÁ.; Lhiaubet, VL. (2018). Sunscreen-Based Photocages for Topical Drugs: A Photophysical and Photochemical Study of A Diclofenac-Avobenzone Dyad. Molecules. 23(3):1-11. https://doi.org/10.3390/molecules23030673S111233Siegel, R. L., Miller, K. D., & Jemal, A. (2018). Cancer statistics, 2018. CA: A Cancer Journal for Clinicians, 68(1), 7-30. doi:10.3322/caac.21442Curtius, K., Wright, N. A., & Graham, T. A. (2017). An evolutionary perspective on field cancerization. Nature Reviews Cancer, 18(1), 19-32. doi:10.1038/nrc.2017.102Brem, R., Guven, M., & Karran, P. (2017). Oxidatively-generated damage to DNA and proteins mediated by photosensitized UVA. Free Radical Biology and Medicine, 107, 101-109. doi:10.1016/j.freeradbiomed.2016.10.488Epe, B. (2012). DNA damage spectra induced by photosensitization. Photochem. Photobiol. Sci., 11(1), 98-106. doi:10.1039/c1pp05190cKarran, P., & Brem, R. (2016). Protein oxidation, UVA and human DNA repair. DNA Repair, 44, 178-185. doi:10.1016/j.dnarep.2016.05.024Montoro, J., Rodriguez, M., Diaz, M., & Bertomeu, F. (2003). Photoallergic contact dermatitis due to diclofenac. Contact Dermatitis, 48(2), 115-115. doi:10.1034/j.1600-0536.2003.480212_1.xFernández-Jorge, B., Goday-Buján, J. J., Murga, M., Molina, F. P., Pérez-Varela, L., & Fonseca, E. (2009). Photoallergic contact dermatitis due to diclofenac with cross-reaction to aceclofenac: two case reports. Contact Dermatitis, 61(4), 236-237. doi:10.1111/j.1600-0536.2009.01596.xMonteiro, A. F., Rato, M., & Martins, C. (2016). Drug-induced photosensitivity: Photoallergic and phototoxic reactions. Clinics in Dermatology, 34(5), 571-581. doi:10.1016/j.clindermatol.2016.05.006Akat, P. (2013). Severe photosensitivity reaction induced by topical diclofenac. Indian Journal of Pharmacology, 45(4), 408. doi:10.4103/0253-7613.114999Kowalzick, L., & Ziegler, H. (2006). Photoallergic contact dermatitis from topical diclofenac in SolarazeR gel. Contact Dermatitis, 54(6), 348-349. doi:10.1111/j.0105-1873.2006.0645f.xEncinas, S., Boscá, F., & Miranda, M. A. (1998). Photochemistry of 2,6-Dichlorodiphenylamine and 1-Chlorocarbazole, the Photoactive Chromophores of Diclofenac, Meclofenamic Acid and Their Major Photoproducts. Photochemistry and Photobiology, 68(5), 640. doi:10.1562/0031-8655(1998)0682.3.co;2Encinas, S., Bosca, F., & Miranda, M. A. (1998). Phototoxicity Associated with Diclofenac:  A Photophysical, Photochemical, and Photobiological Study on the Drug and Its Photoproducts. Chemical Research in Toxicology, 11(8), 946-952. doi:10.1021/tx9800708Moore, D. E., Roberts-Thomson, S., Zhen, D., & Duke, C. C. (1990). PHOTOCHEMICAL STUDIES ON THE ANTIINFLAMMATORY DRUG DICLOFENAC. Photochemistry and Photobiology, 52(4), 685-690. doi:10.1111/j.1751-1097.1990.tb08667.xIoele, G., De Luca, M., Tavano, L., & Ragno, G. (2014). The difficulties for a photolabile drug in topical formulations: The case of diclofenac. International Journal of Pharmaceutics, 465(1-2), 284-290. doi:10.1016/j.ijpharm.2014.01.030Ioele, G., Tavano, L., De Luca, M., Ragno, G., Picci, N., & Muzzalupo, R. (2015). Photostability and ex-vivo permeation studies on diclofenac in topical niosomal formulations. International Journal of Pharmaceutics, 494(1), 490-497. doi:10.1016/j.ijpharm.2015.08.053Aparici-Espert, I., Cuquerella, M. C., Paris, C., Lhiaubet-Vallet, V., & Miranda, M. A. (2016). Photocages for protection and controlled release of bioactive compounds. Chemical Communications, 52(99), 14215-14218. doi:10.1039/c6cc08175dKlán, P., Šolomek, T., Bochet, C. G., Blanc, A., Givens, R., Rubina, M., … Wirz, J. (2012). Photoremovable Protecting Groups in Chemistry and Biology: Reaction Mechanisms and Efficacy. Chemical Reviews, 113(1), 119-191. doi:10.1021/cr300177kŠolomek, T., Wirz, J., & Klán, P. (2015). Searching for Improved Photoreleasing Abilities of Organic Molecules. Accounts of Chemical Research, 48(12), 3064-3072. doi:10.1021/acs.accounts.5b00400Young, D. D., & Deiters, A. (2007). Photochemical control of biological processes. Org. Biomol. Chem., 5(7), 999-1005. doi:10.1039/b616410mYu, H., Li, J., Wu, D., Qiu, Z., & Zhang, Y. (2010). Chemistry and biological applications of photo-labile organic molecules. Chem. Soc. Rev., 39(2), 464-473. doi:10.1039/b901255aPravst, I., Zupan, M., & Stavber, S. (2006). Solvent-free bromination of 1,3-diketones and β-keto esters with NBS. Green Chem., 8(11), 1001-1005. doi:10.1039/b608446jParis, C., Lhiaubet-Vallet, V., Jiménez, O., Trullas, C., & Miranda, M. Á. (2009). A Blocked Diketo Form of Avobenzone: Photostability, Photosensitizing Properties and Triplet Quenching by a Triazine-derived UVB-filter. Photochemistry and Photobiology, 85(1), 178-184. doi:10.1111/j.1751-1097.2008.00414.

Cold vapour generation electrothermal atomic absorption spectrometry and solid phase extraction based on a new nanosorbent for sensitive HG determination in environmental samples (sea water and river water)

Reunión bianual del Grupo Regional Andaluz de la Sociedad Española de Química AnalíticaMercury is not an essential element for plant or animal life and it is a potential environmental toxic because of its tendency to form covalent bonds with organic molecules and the high stability of the Hg-C bond. Reports estimate a total mercury concentration in natural waters ranging from 0.2 to 100 ng L-1. Due to this fact, highly sensitive methods are required for direct determination of such extremely low levels. In this work, a rapid and simple method was developed for separation and preconcentration of mercury by flow injection solid phase extraction coupled with on-line chemical vapour generation electrothermal atomic absorption spectrometry. The system is based on chelating retention of the analyte onto the mini column filled with a mesoporous silica functionalized with 1,5 bis (di-2-pyridyl) methylene thiocarbohydrazide. The main aim of this work was to develop a precise and accurate method for the determination of the Hg. Under the optima conditions and 120 s preconcentration time, the detection limit obtained was 0.009 μg L-1, with RSDs 3.7 % for 0.2 μg L-1, 4.8 % for 1 μg L-1 and enrichment factor 4, Furthermore, the method proposed has permitted the determination of Hg with a reduction in the analysis time, the sample throughput was about 18 h-1, low consumption of reagents and sample volume. The method was applied to the determination of Hg in sea water and river water. For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TMDA 54.4 Fortified Lake, and LGC6187 River sediment was addressed. The results showed good agreement with the certified values.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech