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The impact of the polymeric matrix on the photophysical characteristics of monomeric dyes responsive to excited-state intramolecular proton transfer (ESIPT) was investigated through UV-Vis absorption as well as steady-state and time-resolved emission spectroscopies. For this purpose, two benzoxazole monomers (M1 and M2) with acryloyl groups at different positions in their molecular structures were employed to facilitate covalent bonding within a styrene chain. Our findings reveal significant variations in their excited-state properties due to the proximity of the acryloyl groups, which affects the energy barrier of the ESIPT reaction, the emission wavelength, and the balance between the normal and tautomeric forms. The experimental results were corroborated through theoretical investigations at the DFT/TDDFT level, specifically using the B3LYP-D3/def2-TZVP methodology. Three notable observations emerged: donor/acceptor groups at the meta/para positions induced electron distribution changes, causing red-shifted emission for M2; in the polymer film, particularly in PM1, intramolecular hydrogen bond deactivation favored N* emission over T* emission; and the zwitterionic character of the T* species. This study underscores the advantages of functionalization in polymers, which can lead to colorless films and prevalent N* or T* emission, and contributes valuable insights into molecular design strategies for tailoring the photophysical properties of polymeric materials.

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The synthetic hormone 17α ethinyl estradiol (EE2) is a molecule widely used in female contraceptives and recognized as a contaminant of attention (Watch List) in the European Union due to its high consumption, endocrine effects and occurrence in aquatic environments. Its main source of introduction is domestic sewage where it can be associated with other contaminants such as microplastics (MPs). Due to their characteristics, they can combine with each other and exacerbate their isolated effects on biota. This study evaluated the combined effects of microplastics (MPs) and 17α ethinylestradiol (EE2) on two tropical estuarine invertebrate species: Crassostrea gasar and Ucides cordatus. Polyethylene particles were spiked with EE2 and organisms were exposed to three treatments, categorized into three groups: control group (C), virgin microplastics (MPs), and spiked microplastics with EE2 (MPEs). All treatments were evaluated after 3 and 7 days of exposure. Oysters exhibited changes in phase 2 enzymes and the antioxidant system, oxidative stress in the gills, and reduced lysosomal membrane stability after exposure to MPs and MPEs. Crabs exposed to MPs and MPEs after seven days showed changes in phase 1 enzymes in the gills and changes in phases 1 and 2 enzymes in the hepatopancreas, such as disturbed cellular health. The combined effects of microplastics and EE2 increased the toxicity experienced by organisms, which may trigger effects at higher levels of biological organization, leading to ecological disturbances in tropical coastal ecosystems.

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Propofol, a phenol derivative, is commonly employed as an intravenous anesthetic during clinical procedures, formulated as an oil/water emulsion due to its poor solubility in water. The stability limitations associated with emulsions have prompted research efforts towards developing aqueous formulations of propofol. In this work, we investigate the solubility enhancement of propofol in anionic and cationic surfactants. Our findings reveal that the solubility of propofol can increase significantly, up to 100-fold, depending on the nature of the micellar aggregate, as observed for alkylammonium halogenates CnTAB (for n = 12, 14 and 16), contrasting with the lower solubility with SDS. Interestingly, C14TAB and C16TAB demonstrate significantly higher solubility than C12TAB. This was attributed to the formation of wormlike micelles, in which the propofol molecules are positioned between the cationic heads of the surfactant molecules, changing the micellar curvature and the morphology of the aggregate. Therefore, the aromatic molecules in the micellar environment can be partitioned into the micellar cores and their palisades. Regarding C12TAB, the alkyl chain is too short to form wormlike micelles, thus, concentrating propofol molecules mainly into the micellar core, and consequently, leading to their aggregation. Solubility diagrams of propofol were constructed in conjunction with different surfactants. The systems exhibiting viscoelastic behavior, indicative of wormlike micelle formation, were further investigated using rheology. Additionally, the fluorescent properties of propofol enabled the examination of the anesthetic molecule within diverse micellar environments.

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Isolated fallopian tube torsion (IFTT) is a rare pathology that causes acute abdomen in women, it is even less common in pediatric patients. We present a case of an 11-year-old girl who presented with abdominal pain 24 hours of evolution, the diagnosis could not be specified with cabinet methods, so the definitive diagnosis was made using a diagnostic laparoscopy. A necrotic hemorrhagic tubal cyst was found. A left salpingectomy had to be performed due to necrosis. Early diagnosis can have a positive impact on the fertility of these patients.

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In this study, we present the synthesis of benzimidazo[1,2-a] quinoline-based heterocycles bearing organosulfur and organoselenium moieties through transition-metal-free cascade reactions involving a sequential intermolecular aromatic nucleophilic substitution (SNAr). Both sulfur and selenium derivatives presented absorption maxima located around 355 nm related to spin and symmetry allowing electronic 1π-π* transitions, and fluorescence emission at the violet-blue region (~440 nm) with relatively large Stokes shift. The fluorescence quantum yields were slightly influenced by the chalcogen, with the sulfur derivatives presenting higher values than the selenium analogs. In this sense, the quantum yields for selenium derivatives can probably be affected by the intersystem crossing or even the photoinduced electron transfer process (PET). The compounds were successfully applied in all-solution-processed organic light-emitting diodes (OLEDs), where poly(9-vinylcarbazole) was employed as a dispersive matrix generating single-layer device cells. The obtained electroluminescence spectra are a sum of benzimidazo[1,2-a]quinolines and PVK singlet and/or triplet emissive states, according to their respective energy band gaps. The best diode rendered a luminance of 25.4 cd⋅m-2 with CIE (0.17, 0.14) and current efficiency of 20.2 mcd⋅A-1, a fivefold improvement in comparison to the PVK device that was explained by a 50-fold increase of charge-carriers electrical mobility.

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Herein, we report the synthesis and characterization of two Pt(II) coordination compounds, the new platinum(II)[N,N'-bis(salicylidene)-3,4-diaminobenzophenone)] ([Pt(sal-3,4-ben)]) and the already well-known platinum(II)[N,N'-bis(salicylidene)-o-phenylenediamine] ([Pt(salophen)]), along with their application as guests in a poly [9,9-dioctylfluorenyl-2,7-diyl] (PFO) conjugated polymer in all-solution processed single-layer white organic light-emitting diodes. Completely different performances were achieved: 2.2% and 15.3% of external quantum efficiencies; 2.8 cd A-1 and 12.1 cd A-1 of current efficiencies; and 3103 cd m-2 and 6224 cd m-2 of luminance for the [Pt(salophen)] and [Pt(sal-3,4-ben)] complexes, respectively. The Commission Internationale de l'Eclairage (CIE 1931) chromaticity color coordinates are (0.33, 0.33) for both 0.1% mol/mol Pt(II):PFO composites at between approximately 3.2 and 8 V. The optoelectronic properties of doped and neat PFO films have been investigated, using steady-state and time-resolved photoluminescence. Theoretical calculations at the level of relativistic density functional theory explained these results, based on the presence of the Pt(II) central ion's phosphorescence emission, considering spin-orbit coupling relationships. The overall results are explained, taking into account the active layer morphological properties, along with the device's electric balance and the emitter's efficiencies, according to deep-trap space-charge models. Considering the very simple structure of the device and the ease of synthesis of such compounds, the developed framework can offer a good trade-off for solution-deposited white organic light-emitting diodes (WOLEDs), with further applications in the field of lighting and signage.

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RESUMEN Introducción: La infección por SARS-CoV-2 produce alteraciones laboratoriales, que, si bien son inespecíficas, sus valores pueden resultar de utilidad como marcadores pronósticos. Materiales y métodos: Estudio observacional, analítico de casos y controles, con un muestreo no probabilístico de casos consecutivos de enero a julio de 2021 en pacientes con infección a SARS-CoV-2 del Hospital Nacional. Resultados: Se incluyeron un total de 237 pacientes (79 casos y 158 controles), la franja etaria estuvo comprendida de 21 a 90 años (53,67±15,11). El 66,7% era del sexo masculino. Se hallaron diferencias estadísticamente significativas, con tendencia de los pacientes fallecidos a presentar valores más elevados de leucocitos (12600 vs 9672; p=0,001), PCR (15,40 vs 10,97; p=0,002), Dímero D (15725 vs 3714; p=0,004), Ferritina (1312 vs 1049; p=0,020), Troponina I (1,71 vs 1,87; p=0,003). Conclusión: Los valores de leucocitos, PCR, Dímero D, Ferritina, Troponina I, se asocian significativamente a la mortalidad en esta serie de casos.

ABSTRACT Introduction : SARS-CoV-2 infection produces laboratory abnormalities, which, although they are nonspecific, their values can be useful as prognostic markers. Materials and methods : Observational, analytical study of cases and controls, with a non-probabilistic sampling of consecutive cases from January to July 2021 in patients with SARS-CoV-2 infection at Hospital National. Results : A total of 237 patients (79 cases and 158 controls) were included, the age range was between 21 and 90 years (53.67±15.11). 66.7% were male. Statistically significant differences were found, with a tendency for deceased patients to present higher values of leukocytes (12,600 vs 9,672; p=0.001), CRP (15.40 vs 10.97; p=0.002), D-dimer (15,725 vs 3,714 ; p=0.004), Ferritin (1312 vs 1049; p=0.020), Troponin I (1.71 vs 1.87; p=0.003). Conclusion : The values of leukocytes, PCR, Dimer D, Ferritin, Troponin I, are significantly associated with mortality in this series of cases.

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We evaluated the environmental quality in mangrove areas of the Western Atlantic with different levels and history of contamination, considering biomarkers for the crab Ucides cordatus. For this purpose, specimens were collected in two climatic seasons (rainy and dry seasons) and assays of genotoxicity (MN, micronucleus), cytotoxicity (NRRT, neutral red retention time) and biochemical (MT, metallothionein; and LPO, lipoperoxidation) were conducted. In the most impacted mangroves, there was an increase in the mean of micronucleus (frequency of MN/1000), which was associated with a shorter retention time (minutes of NRRT). In contrast, the most pristine areas showed MN < 3 and NRRT < 100 min, with no seasonal effect, indicating a lower effect of degenerative processes by xenobiotics. The rainy season was more harmful, especially regarding cytogenotoxicity. The use of bioindicator species for environmental monitoring should be guided by an analysis of biomarkers considering the season, because during the period of highest rainfall, biomarkers values can change.

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RESUMEN Algunos estudios han encontrado que la severidad de la COVID-19 se asocia con una alta carga viral determinada por los números de ciclos (Ct) de amplificación de ADN de SARS-CoV-2. El objetivo fue determinar la relación entre el umbral de ciclos de PCR de SARS-CoV-2 y la severidad de la infección por el virus SARS-COV-2 en pacientes internados y ambulatorios en un hospital de referencia entre marzo a junio del 2021. Estudio retrospectivo observacional analítico de corte trasverso de pacientes adultos con COVID-19, ambulatorios e internados en el Hospital Nacional. Se incluyeron los pacientes cuya infección fue confirmada por RT-PCR para SARS-CoV-2, se consideró un punto de corte para Ct60 años (36,6%), estuvieron hospitalizados (69,8%), internados en sala (57,1%), y admitidos en cuidados intensivos (12,8%), tiempo medio de enfermedad 8,48 ± 4,2 días. La mortalidad fue de 22,2%. Se encontró mayor riesgo de fallecer para los pacientes con Ct 60 años (OR: 3,69; IC95%: 2,39-5,68). Estos dos factores permanecieron asociados con el óbito en el análisis multivariado. Hubo mayor riesgo de hospitalizarse y fallecer en los pacientes con Ct<25. El valor Ct podría ser útil para la predicción del curso clínico y el pronóstico de los pacientes con COVID-19.

ABSTRACT Some studies have found that severity of COVID-19 is associated with a high viral load determined by the number of cycles (Ct) of SARS-CoV-2 DNA amplification. The objective was to determine the relationship between the Ct value and the severity of the SARS-COV-2 virus infection in inpatients and outpatients at a reference hospital in Paraguay between March and June 2021. Cross-sectional retrospective study of adult patients with COVID-19, ambulatory and hospitalized admitted to the National Hospital. Patients whose infection was confirmed by RT-PCR for SARS-CoV-2 were included, a cut off point of Ct 60 years (36.6%), hospitalized (69.8%), admitted to ward (57.1%), and admitted to intensive care (12.8%), mean time of illness 8.48 ± 4.2 days and mortality was 22.2%. A higher risk of death was found for patients with Ct 60 years (OR: 3.69; 95% CI: 2.39-5.68). These two factors remained associated with death in the multivariate analysis. There was a higher risk of hospitalization and death in patients with TC <25. Ct value could be useful for predicting clinical course and prognosis of COVID-19 patients.

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La investigación se refiere a un estudio de la rentabilidad de la acción del viraje del estilo libre en nadadoras escolares. El objetivo para la investigación se centró en evaluar las características temporales durante la acción del viraje en nadadoras de la categoría 13 y 14 años de la provincia de Sancti Spíritus. Para la recogida de la información, se utilizaron los métodos del nivel empírico: la observación científica, así como la de medición. Se utilizaron dos cámaras de videos, ubicadas en serie, y una cámara subacuática marca Sony. Para el análisis temporal, se requirió del software Kinovea, ver 0.9.3. Se aplicó el test de 15 m. para comprobar la rentabilidad del viraje. Se pudo comprobar una pobre efectividad de este elemento técnico en el estilo libre en las nadadoras evaluadas, lo que mostró, de forma generalizada, deficiencias durante la fase de impulso y se comprobó la formación de ángulos muy abiertos de las piernas que favoreció un déficit en la utilización de la potencia de las piernas durante el empuje de la pared, aspecto este que ayudó a disminuir el deslizamiento y comenzar a realizar los movimientos de salida a la superficie de forma prematura, aumentó el tiempo de forma general en la ejecución del viraje, concluyendo que para las categorías escolares es oportuno obtener ángulos entre las articulaciones de tobillos, rodillas y cadera en el rango de los 90° y 110° al momento de iniciar el impulso de la pared.

A pesquisa diz respeito a um estudo sobre a rentabilidade da ação de viragem em estilo livre em nadadores escolares. O objectivo da investigação foi centrado na avaliação das características temporárias durante a ação de viragem em nadadores de 13 e 14 anos de idade na província de Sancti Spíritus. Para a recolha de informação, foram empregues métodos empíricos: observação científica e medição. Foram instaladas duas câmaras de vídeo, colocadas em série, e uma câmara subaquática Sony. Para a análise temporal, foi utilizado o software Kinovea, ver 0.9.3. O teste de 15 m foi executado para verificar a relação custo-benefício da curva. Foi possível constatar uma baixa eficácia deste elemento técnico no estilo livre dos nadadores avaliados, que mostraram, em geral, deficiências durante a fase de impulso e a formação de ângulos de pernas muito abertos que favoreceram um défice na utilização da força das pernas durante o impulso para a parede, Este aspecto permitiu reduzir o deslizamento e começar a realizar os movimentos de saída para a superfície antecipadamente, aumentou o tempo total na execução da curva, concluindo-se que para as categorias escolares é adequado obter ângulos entre o calcanhar, o joelho e as articulações da anca na gama de 90° e 110° no momento de iniciar o impulso da parede.

The research refers to a study of the profitability of the freestyle turning action in school swimmers. The objective of the research was focused on evaluating the temporal characteristics during the action of the turn in swimmers of the 13 and 14 years old category in the province of Sancti Spíritus. For the collection of information, the empirical level methods used were: scientific observation, as well as measurement. Two video cameras, placed in series, and a Sony underwater camera were used. For the temporal analysis, the Kinovea software, ver 0.9.3, was used. The 15 m test was applied to check the profitability of the turn. It was possible to verify a poor effectiveness of this technical element in the freestyle in the swimmers evaluated, which showed, in a generalized way, deficiencies during the impulse phase and the formation of very open angles of the legs that favored a deficit in the use of the power of the legs during the wall push, This aspect helped to decrease the sliding and to begin to perform the exit movements to the surface prematurely, increased the time in general in the execution of the turn, concluding that for the school categories it is appropriate to obtain angles between the ankle, knee and hip joints in the range of 90° and 110° at the moment of initiating the wall push.

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Speeding up the phosphorescence channel in luminescent copper(I) complexes has been extremely challenging due to the copper atoms relatively low spin-orbit coupling constant compared to heavier metals such as iridium. Here, we report the synthesis and characterization of three mononuclear copper(I) complexes with diimines, triphenylphosphine, and iodide ligands to evaluate the effect of the copper-iodide (Cu-I) moiety into the phosphorescence decay pathway. Temperature-dependent photophysical studies revealed combined thermally activated delayed fluorescence and phosphorescence emission, with a phosphorescence decay rate of the order of 104 s-1. Density functional theory calculations indicate very high spin-orbit coupling matrix elements between the low-lying states of these complexes. Compared to the classical [Cu(phen)(POP)]+, our results demonstrate that Cu-I is a versatile moiety to speed up the phosphorescence decay pathway in about one order of magnitude, and it can be prepared by a simplified synthetic route with few synthetic steps. Furthermore, the SOC matrix elements and the phosphorescence decay rates of these complexes are comparable to those of extensively applied coordination complexes based on heavier metals, making them a promising alternative as active layers of organic light-emitting diodes.

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INTRODUCTION: Appendectomy is one of the most common surgical procedures performed worldwide There are different etiologies for acute appendicitis such as obstruction of the appendiceal lumen by fecalith, lymphoid hyperplasia, or neoplasm. Laparoscopic appendectomy has become the treatment of choice for both complicated and uncomplicated appendicitis; common postoperative complications include wound infection, bleeding, intraabdominal abscess. Stump appendicitis is defined as the interval repeated inflammation of remaining residual appendiceal tissue after an appendectomy. PRESENTATION OF CASE: 38-Year-old female patient with a history of laparoscopic appendectomy performed in 2016 for acute uncomplicated appendicitis. She arrived to the emergency room due to abdominal pain 7 out of 10, located in the periumbilical region, later with migration to the right lower quadrant, abdominal CT scan evidenced the presence of a cecal and pericecal inflammatory process as well as the base and residual proximal portion of the cecal appendix laparoscopic stump appendectomy was performed. DISCUSSION: Stump appendicitis (SA) is defined as the inflammation of the remnant of the cecal appendix after an appendectomy, whether due to impaction of a fecalith or secondary to an ischemic process, the probability of developing SA is estimated to be about 1/50,000 cases throughout life. The most frequently used treatment is exploratory laparotomy to complete the previous appendectomy; however, there are 5 reported cases of stump appendicitis, where surgical resolution was performed through laparoscopic surgery. CONCLUSIONS: It is important to keep this entity in mind when evaluating a patient with acute abdomen with previous history of appendectomy, since the delay in diagnosis and treatment increases morbidity and mortality; laparoscopic stump appendectomy has been shown to be a safe treatment (Agha et al., 2020 [14]).1.

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A low-cost signal processing circuit developed to measure and drive a heat dissipation soil matric potential sensor based on a single thermosensitive resistor is demonstrated. The SnSe2 has a high thermal coefficient, from -2.4Ω/°C in the 20 to 25 °C to -1.07Ω/°C in the 20 to 25 °C. The SnSe2 thermosensitive resistor is encapsulated with a porous gypsum block and is used as both the heating and temperature sensing element. To control the power dissipated on the thermosensitive resistor and keep it constant during the heat pulse, a mixed analogue/digital circuit is used. The developed control circuit is able to maintain the dissipated power at 327.98±0.3% mW when the resistor changes from 94.96Ω to 86.23Ω. When the gravimetric water content of the porous block changes from dry to saturated (θw=36.7%), we measured a variation of 4.77Ω in the thermosensitive resistor, which results in an end-point sensitivity of 130 mΩ/%. The developed system can easily meet the standard requirement of measuring the gravimetric soil water content with a resolution of approximately Δθw=1%, since the resistance is measured with a resolution of approximately µ31µΩ, three orders of magnitude smaller than the sensitivity.

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Multivariate Curve Resolution with Alternating Least Squares (MCR-ALS) was for the first time successfully used to evaluate an intricate photophysical behavior, where deprotonation on the electronic ground state (S0), intra and intermolecular proton transfer processes (ESPT and ESIPT) on the electronic excited state (S1) can simultaneously be presented. In this sense, the organic dye 2-(2'-hydroxyphenyl)benzothiazole (HBT) was used as a proof-of-concept model, where MCR-ALS showed to be a powerful tool for discriminate chemical reactions that occur concomitantly on different potential energy surfaces, which include photochemical reactions. As a result, the chemometric method showed to be a straightforward approach for the determination of the acidic strengths of those equilibria were estimated as 8.61 and 1.11 to hydroxyl deprotonation on electronic ground and excited states, respectively.

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Lead is a priority pollutant introduced in the aquatic environment by different sources commonly located in estuarine regions, such as ports, marinas and industries. Environmental agencies around the world set the maximum allowable concentration of lead in effluents, surface water and sediment, but few studies reported its accumulation and chronic toxicity in mangrove benthic invertebrates using concentrations believed to be safe. In the case of Brazilian mangrove environments, Ucides cordatus is a crab species of choice to be used in bioaccumulation studies. We have assessed biomarkers' responses (DNA strand breaks, micronucleated cells, metallothioneins, enzymatic activity of aminolevulinic acid dehydratase and neutral red retention time) and the total bioaccumulation in six tissues of U. cordatus crabs resident to mangrove areas under different conservation status during a 28-day period bioassay. We also investigated Pb subcellular partition and biomarkers' responses using a supposedly safe concentration (10 µg L-1). During the Pb exposure, the highest concentration of Pb was observed in crab gills. Crabs also showed a high ability to allocate Pb in detoxified forms. Multivariate analysis pointed out that bioaccumulation (total, active and detoxified) is linked to biomarkers. Even in supposedly safe dosage, U. cordatus triggered its defense mechanisms expressing more metallothioneins and presented relevant cyto-genotoxic damage. Our data suggest the development of biological tolerance to Pb in crabs from polluted areas. Our results provided a new insight about lead toxicity even at concentrations considered environmentally safe, which could support new strategies to manage estuarine areas considering their respective conservation status.

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Globally, there is limited knowledge about management and conservation of Callianassidae family. Their catches seem to be recently increasing in several parts of the world and evidences raise concern on the need of specialized literature focused on populations monitoring. At Southeast of Brazil, the species Callichirus major (Say 1818), known as the ghost shrimp, is frequently captured for use as bait in sport fishing and, according to previous studies, the overexploitation could threaten the population. The aim of this study was evaluated over a year this harmful human pressure on the species C. major in two beaches contiguous but susceptible to different anthropogenic impacts due to the existence of legislation on one beach that prohibits the capture of this crustacean. The population of C. major presented where the prohibition regulation does not exist a density almost three times lower when compared to the beach that prohibits the capture, with individuals with smaller carapace oval area and a shorter reproductive period. This paper alert to some evidence of C. major structure population disturbance resulting from its exploitation at Southeast of Brazil. Recommendations were also addressed to conservation management considering the species' ecological importance.

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The changes in the ability of three fluorescent derivatives of 2-(2'-hydroxyphenyl)benzothiazole to undergo excited-state intramolecular proton transfer (ESIPT) processes have been correlated with the rheological properties of four amino-polydimethylsiloxanes with different molar masses and containing different amounts of monomer units with amino pendant groups, in the presence and absence of a cross-linking molecule, CO2. The changes lead to a variety of species (keto, enol, and enolate forms) in both the ground and excited states. Calculations using the density-functional theory/time-dependent density-functional theory method at the CAM-B3LYP/6-311++G(d,p) level helped to identify how ESIPT is involved in the formation of the intermediates. The results demonstrate that proton transfer in 2-(2'-hydroxyphenyl)benzothiazoles is a powerful tool to identify local changes in the viscosity and micropolarity of the environment that are attributed to the structural differences of the amino-polydimethylsiloxanes and their cross-linking.

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Metals are persistent pollutants, able to accumulate in the biota and magnify in trophic web. In the specific case of cadmium contamination, it has been the subject of considerable interest in recent years because of its biological effects and it is one of major pollutant in estuarine areas. Ucides cordatus is considered a mangrove local sentinel crab species in Brazil and there are previous studies reporting crab subpopulations living from pristine to heavily metal impacted areas in São Paulo coast (Southeastern Brazil). Taking into account the background knowledge about these subpopulations, we proposed the hypothesis that crabs from a highly polluted mangrove (Cubatão - CUB) have developed biological tolerance to cadmium compared to animals from an Environmental Protected Area (Jureia - JUR). Aiming to verify this hypothesis, we have investigated total bioaccumulation and subcellular partition of Cd, besides biomarkers' responses during a long-term exposure bioassay (28 days, with weekly sampling) using a supposedly safe Cd concentration (0.0022 mg L-1). Specimens from the pristine area (JUR) accumulated higher total Cd, as such as in its biologically active form in gills. Animals living in the polluted site (CUB) presented higher amounts of Cd in the mainly detoxifying tissue (hepatopancreas), which could be considered a pathway leading to tolerance for this metal. Multivariate analysis indicated that bioaccumulation (active, detoxified and total Cd) is linked to geno-cytotoxic damages. CUB subpopulation was considered more tolerant since it presented proportionally less damage and more capacity to allocate Cd in the main detoxifying forms and tissues.

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HYPOTHESIS: When tetradecyltrimethylammonium bromide, TTAB, is added to aqueous solution of sodium salicylate, NaSal, the threading of the aromatic anion into the micellar palisade leads to the formation of wormlike micelles. Based on the calorimetric titration of NaSal with TTAB, and on the lifetime of fluorescence of salicylate, we propose that the aggregation of the two components directly leads to the formation of wormlike micelles, without any pre-aggregation. EXPERIMENTS: By using an isothermal titration calorimeter, aliquots of TTAB were added to a dilute solution of NaSal. The energy involved in each addition was then integrated and the variation of enthalpy was determined. In the same range of concentrations and molar ratios, the surface tensiometry and time-resolved emission spectroscopy experiments were performed. FINDINGS: A very characteristic calorimetric signal associated with wormlike micelle formation was obtained, being the enthalpy variation of this process, ΔWLMH2980 < 0. When 1.2 mmol L-1 of NaSal is titrated with 11.0 mmol L-1 of TTAB at 298.15 K, ΔfH2980 = -10.31 kJ per mol of injectant. By adding TTAB to NaSal solution, two fluorescence lifetimes of salicylate were observed solely after wormlike micelle being formed. The correspondent lifetime values of 4.0 ns and 7.2 ns are respectively associated with the free and associated species of salicylate. The new results demonstrated that wormlike micelles are the first aggregate formed when TTAB is added to salicylate. This aspect is relevant for understanding the mechanism of wormlike micelles formation.

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A simple method for the direct mono- and bis-organylselenylation of N-substituted pyrroles through a multicomponent reaction promoted by ultrasonic radiation was described. These sonochemical promoted reactions were performed between different primary amines, 2,5-hexanedione and dialkyl, diheteroaryl, or diaryl diselenides, using catalytic amounts of copper iodide. Depending on the amount of copper iodide and diorganyl diselenide used in the reactions, mono- or bis-organylselenylation products were efficiently synthesized in high yields.