Degradation of acetonitrile residues using oxidation processes

Several oxidation processes were investigated to degrade residues of acetonitrile. Alternatives such as photolysis, degradation with hydrogen peroxide, Fenton and photo-Fenton processes were investigated. Among the options studied, photolysis proved to be the best choice. Photolysis promoted 100% degradation of 20% aqueous acetonitrile solutions in 30 hours. This method proved to be a cheap alternative to decompose toxic residues of acetonitrile, which tend to be accumulated in laboratories that use RP-HPLC equipments.Neste trabalho são relatados vários processos de oxidação para a degradação de acetonitrila. Foram investigadas alternativas como fotólise, degradação com peróxido de hidrogênio, processos Fenton e foto-Fenton. A fotólise, o processo mais simples e de menor custo dentre os avaliados, promoveu 100% de degradação de soluções aquosas de acetonitrila a 20%, após 30 horas de irradiação. Este método apresenta, portanto várias vantagens dentre as opções a serem usadas em processos de decomposição de resíduos tóxicos de acetonitrila, os quais tendem a se acumular em laboratórios que utilizam equipamentos de Cromatografia Líquida de Alta Eficiência com Fase Reversa.509513Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

The role of calcium in intracellular trafficking

The molecular mechanism of membrane fusion essential to vital cellular activities such as intracellular transport, hormone secretion, enzyme release, or neurotransmission, involve the assembly and disassembly of a specialized set of proteins in opposing bilayers. Recent evidences shed new light on the role Ca has in the regulation of this mechanism in which the Golgi apparatus works as a central station; from here, Ca ions are released into and recovered from the cytosol during the different steps of the cargo progression. In fact, transient cytosolic Ca fluctuations take a crucial role to recruit proteins and enzymes Ca-sensitive on Golgi membranes where they are involved in membranes remodelling which is fundamental process for the fusion events that allow protein trafficking. Here I provide an overview of the role Ca plays in intra-Golgi trafficking underlying some interesting aspects to clarify the mechanisms of cargo progression

Photoelectrochemistry Of Poly(3-methylthiophene), I: Surface Morphology And Thickness Effect

Photocyclovoltammetric experiments with films of poly(3-methylthiophene) under polychromatic light irradiation show a p-type semiconductor behavior in the reduced state, with a flat band potential of 0.18 V. The photocurrent depends on film thickness and surface morphology. Films with different thickness were characterized by scanning electron microscopy, indicating a globular morphology with globule sizes changing according to the charge density used during polymer deposition. The highest photocurrent is observed for the lowest globule diameter. These films were also irradiated with monochromatic light from the electrolyte side and from the substrate side. A higher photocurrent and a photocurrent spectrum matching the absorption spectrum of the reduced form of the polymer is observed on irradiation from the electrolyte side of a 0.7 μm thick film. In contrast, for irradiation from the electrode side, the photocurrent is lower and the spectrum shows a peak at lower energy. These results were interpreted in terms of a delocalized space charge zone, different kinetics for charge transfer and mass transport across the solvent swollen polymer film and different depth of penetration of the light as a function of wavelength.4317991Horowitz, G., (1990) Adv. Mater., 2, p. 287Glenis, S., Tourillon, G., Garnier, F., (1984) Thin Solid Films, 111, p. 93Glenis, S., Tourillon, G., Garnier, F., (1986) Thin Solid Films, 139, p. 221Glenis, S., Tourillon, G., Garnier, F., (1984) Thin Solid Films, 122, p. 9Kaneto, K., Ishii, G., Yoshino, K., (1985) Jpn. J. Appl. Phys., 24, pp. L320Peramunage, D., Tomkiewicz, M., Ginley, D.S., (1987) J. Electrochem. Soc., 134, p. 1384Youm, I., Cadene, M., Laplaze, D., Rincot, D., Vedel, J., (1992) J. Chim. Phys., 89, p. 1105Frank, A.J., Glenis, S., Nelson, A.J., (1989) J. Phys. Chem., 93, p. 3818Glenis, S., Frank, A.J., (1989) Synth. Met., 28, pp. C681Fang, Y., Chen, S.-A., Chu, M.L., (1992) Synth. Met., 52, p. 261Chen, S.A., Fang, Y., (1993) Angew. Makromol. Chem., 208, p. 79Miquelino, F.L.C., De Paoli, M.-A., Gèniés, E.M., (1994) Synth. Met., 68, p. 91Abrantes, L.M., Castillo, L.M., Fleischmann, M., Hill, I.R., Peter, L.M., Mengoli, G., Zotti, G., (1984) J. Electroanal. Chem., 177, p. 129Li, Z., Dong, S., (1992) Electrochim. Acta, 37, p. 1003Lindquist, S.-E., Lindstöm, H., Petterson, H., Södergren, S., Rensmo, H., Solbrand, A., (1994) Proc. 10th Int. Conf. on Photochemical Conversion and Storage of Solar Energy, p. 429. , InterlakenHagfeldt, A., Björkstén, U., Lindquist, S.-E., (1992) Sol. Energy. Mater. Sol. Cells, 27, p. 293Lindquist, S.-E., Finnström, B., Tegnér, L., (1983) J. Electrochem. Soc., 130, p. 351Hodes, G., Howell, I.D.J., Peter, L.M., (1992) J. Electrochem. Soc., 139, p. 3136Södergren, S., Hagfeldt, A., Olsson, J., Lindquist, S.-E., (1994) J. Phys. Chem., 98, p. 5552Schroeder, A.F., Kaufman, F.B., Patel, V., Engler, E.M., (1980) J. Electroanal. Chem., 113, p. 193Tanguy, J., Baudoin, J.L., Chao, F., Costa, M., (1992) Electrochim. Acta, 37, p. 141

La fauna di spugne di Porto Tricase, Canale d\u2019Otranto

This study deals with the sponge fauna of Porto Tricase, Strait of Otranto, Ionian Sea. The present sponge fauna was compared with that described by Pulitzer-Finali more than 40 years ago. The main results are three new findings for the Ionian Sea, a second record for the Mediterranean Sea and a likely new sponge species

The electronic behavior of poly(3-octylthiophene) electrochemically synthesized onto Au substrate

The consequences of declining biodiversity remain controversial, in part because many studies focus on a single metric of ecosystem functioning and fail to consider diversity's integrated effects on multiple ecosystem functions. We used tide pool microcosms as a model system to show that different conclusions about the potential effects of producer diversity on ecosystem functioning may result when ecosystem functions are measured separately vs. together. Specifically, we found that in diverse seaweed assemblages, uptake of either nitrate or ammonium alone was equal to the average of the component monocultures. However, when nitrate and ammonium were available simultaneously, uptake by diverse assemblages was 22% greater than the monoculture average because different species were complementary in their use of different nitrogen forms. Our results suggest that when individual species have dominant effects on particular ecosystem processes (i.e., the sampling effect), multivariate complementarity can arise if different species dominate different processes. Further, these results suggest that similar mechanisms ( complementary nutrient uptake) may underlie diversity - functioning relationships in both algal and vascular-plant-based systems

Shallow-water sponge grounds along the Apulian coast (central Mediterranean Sea)

Sponge grounds are complex three-dimensional benthic habitats dominated by sponges. These sponge-dominated assemblages have been reported worldwide, from the intertidal zone to the deep sea. In shallow euphotic waters, dense sponge aggregations have been mainly found in tropical areas, and their presence is in some cases related to environmental degradation and coral decline. The Mediterranean Sea is globally recognised as a biodiversity hotspot, where light-exposed rocky reefs are typically dominated by photophilous algae. However, high local anthropogenic pressures, coupled with climate change, are leading to the reorganisation of benthic communities and the occurrence of regime shifts in several areas. Here we report the first description of unusual, shallow-water sponge grounds in Mediterranean light-exposed rocky reefs, in an area previously impacted by the destructive date-mussel fishery. These assemblages, found along the Apulian coast (central Mediterranean Sea), are now (2017) characterised by a mean coverage of sponges ranging between 3% and 33%, with maximum values up to 85%. Variation in the structure of assemblages and in the abundance of individual taxa between depths has been tested by multivariate and univariate techniques. The spatial characterisation has been complemented with the taxonomic analysis of the sponge assemblages, which resulted in the identification of 14 sponge taxa. These findings are compared with results of previous research in the same area and discussed with particular reference to the potential variables involved in sponge dominance and spatial distribution in the present system and elsewhere

Degradation of acetonitrile residues using oxidation processes

Several oxidation processes were investigated to degrade residues of acetonitrile. Alternatives such as photolysis, degradation with hydrogen peroxide, Fenton and photo-Fenton processes were investigated. Among the options studied, photolysis proved to be the best choice. Photolysis promoted 100% degradation of 20% aqueous acetonitrile solutions in 30 hours. This method proved to be a cheap alternative to decompose toxic residues of acetonitrile, which tend to be accumulated in laboratories that use RP-HPLC equipments