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Integrins are heterodimeric transmembrane proteins that play a fundamental role in the migration of leukocytes to sites of infection or injury. We found that protein tyrosine phosphatase nonreceptor type 22 (PTPN22) inhibits signaling by the integrin lymphocyte function-associated antigen-1 (LFA-1) in effector T cells. PTPN22 colocalized with its substrates at the leading edge of cells migrating on surfaces coated with the LFA-1 ligand intercellular adhesion molecule-1 (ICAM-1). Knockout or knockdown of PTPN22 or expression of the autoimmune disease-associated PTPN22-R620W variant resulted in the enhanced phosphorylation of signaling molecules downstream of integrins. Superresolution imaging revealed that PTPN22-R620 (wild-type PTPN22) was present as large clusters in unstimulated T cells and that these disaggregated upon stimulation of LFA-1, enabling increased association of PTPN22 with its binding partners at the leading edge. The failure of PTPN22-R620W molecules to be retained at the leading edge led to increased LFA-1 clustering and integrin-mediated cell adhesion. Our data define a previously uncharacterized mechanism for fine-tuning integrin signaling in T cells, as well as a paradigm of auto-immunity in humans in which disease susceptibility is underpinned by inherited phosphatase mutations that perturb integrin function. 2016

Introduction: COPD and smoking are closely linked to each other. Aim: Compare main characteristics between current and former COPD smokers and analyze the association between smoking status and development of exacerbations and mortality. Methods: Retrospective study with COPD patients from the specialist clinic. Severe exacerbations (requiring hospitalization or visit to the emergency department) in the following 2 years after inclusion were recorded. Disease impact was measured by the CAT questionnaire. Results: Patients main characteristics are displayed in table 1. Focusing on the number of exacerbations,no differences were found between groups (table 2). No correlation was found between the number of years of abstinence and the number of exacerbations (Graphic 2). Conclusions: 33% of COPD patients were active smokers. Current smokers were younger, with a higher pack-years index, were diagnosed earlier, had less severe airflow obstruction, and similar disease impact. No correlation was found between smoking status and development of exacerbations. No mortality differences were found between groups.

INTRODUCTION: Lung cancer has the highest mortality rate and it is rising in women and non-smokers.Due to the increase in smoking habit of women the data have become similar. OBJECTIVE: To determine the development of lung cancer in women comparing clinical-epidemiological features and survival rates of two cohorts from different decades. METHODS: Descriptive retrospective study.Two cohorts of women diagnosed with lung cancer.The data were presented at Lung Tumor Committee of our hospital from 2000-2002 and 2011-2013.Chi square and Student t-test were used.Survival was assessed in 2004 and 2015.Level of significance was set at p RESULTS: CONCLUSIONS: Age at which lung cancer in women is diagnosed has not been modified.There is an increase of active smokers although the majority are former smokers.Adenocarcinoma is still the most frequent histological type.There are no significant differences between patients in operable and inoperable stages of cancer.The majority of tumors are still diagnosed in late stages.Death due to lung cancer has been significantly reduced from 60.9%to31.8%(p=0.02).There are no significant differences in two-year survival rate when compared with the past decade.

Climate change affects distribution and persistence of species. However, forecasting species’ responses to these changes requires long-term data series that are often lacking in ecological studies. We used 15 years of small mammal trapping data collected between 1978 and 2015 in 3 areas at Do~nana National Park (southwest Spain) to (i) describe changes in species composition and (ii) test the association between local climate conditions and size of small mammal populations. Overall, 5 species were captured: wood mouse Apodemus sylvaticus, algerian mouse Mus spretus, greater whitetoothed shrew Crocidura russula, garden dormouse Eliomys quercinus, and black rat Rattus rattus. The temporal pattern in the proportion of captures of each species suggests that the small mammal diversity declined with time. Although the larger species (e.g., E. quercinus), better adapted to colder climate, have disappeared from our trapping records, M. spretus, a small species inhabiting southwest Europe and the Mediterranean coast of Africa, currently is almost the only trapped species. We used 2- level hierarchical models to separate changes in abundance from changes in probability of capture using records of A. sylvaticus in all 3 areas and of M. spretus in 1. We found that heavy rainfall and low temperatures were positively related to abundance of A. sylvaticus, and that the number of extremely hot days was negatively related to abundance of M. spretus. Despite other mechanisms are likely to be involved, our findings support the importance of climate for the distribution and persistence of these species and raise conservation concerns about potential cascading effects in the Do~nana ecosystem

The aim of this work was to study the influence of nutrients on the tolerance, removal efficiency and accumulation of high concentration of Cr(III) by Typha domingensis. This species was exposed to the following Cr(III) treatments, arranged in triplicate: 200 mg L−1 Cr; 600 mg L−1 Cr; 200 mg L−1 Cr + 50 mg L−1 P + 50 mg L−1 N; 600 mg L−1 Cr + 50 mg L−1 P + 50 mg L−1 N; without metal or nutrient additions (control 1); 50 mg L−1 P + 50 mg L−1 N, without metal addition (control 2). In order to simulate extreme events, the concentrations studied were higher than the concentrations commonly found in constructed wetlands. Cr and nutrient concentrations in water decreased in all treatments along time. Nutrient addition did not affect Cr removal for the two concentrations studied. In tissues, the highest Cr concentrations were observed in roots in all treatments. The mass balance showed that sediment showed the highest accumulation of Cr. Metals caused growth inhibition and a decrease in chlorophyll concentration. Despite these sublethal effects, T. domingensis demonstrated that it could accumulate Cr. These results confirm the high tolerance of this species ensuring the survival plant and wetland efficiency in time. Fil: Mufarrege, María de Las Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Di Luca, Gisela Alfonsina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Sánchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Hadad, Hernán Ricardo. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina

DNA damage independent of caspase activation accompanies programmed cell death in different vertebrate embryonic organs. We analyzed the significance of DNA damage during the regression of the interdigital tissue, which sculpts the digits in the embryonic limb. Interdigit remodeling involves oxidative stress, massive apoptosis and cell senescence. Phosphorylation of H2AX mediated by ATM precedes caspase dependent apoptosis and cell senescence during interdigit regression. The association of γH2AX with other downstream DNA repair factors, including MDC1, Rad50 and 53BP1 suggests a defensive response of cells against DNA damage. The relative distribution of cells γH2AX-only positive, TUNEL-only positive, and cells double positive for both markers is consistent with a sequence of degenerative events starting by damage of the DNA. In support of this interpretation, the relative number of γH2AX-only cells increases after caspase inhibition while the relative number of TUNEL-only cells increases after inhibition of ATM. Furthermore, cultured interdigits survived and maintained intense chondrogenic potential, even at advanced stages of degeneration, discarding a previous commitment to die. Our findings support a new biological paradigm considering embryonic cell death secondary to genotoxic stimuli, challenging the idea that considers physiological cell death a cell suicide regulated by an internal death clock that pre-programmes degeneration.

O Genocídio Armênio (1915-16) é negado até hoje com veemência pelo governo turco, com apoio de várias nações interessadas em manter a versão oficial em detrimento da verdade histórica. Infelizmente, as vozes dos sobreviventes demoraram demais para serem ouvidas e registradas enquanto testemunhos. Detalhes sobre esta tragédia, considerada como o protótipo do genocídio moderno, foram esquecidos por tempo suficiente para que Hitler proferisse a famosa frase: “afinal, quem fala da aniquilação dos Armênios hoje?”.

este estudo objetivou desenvolver e verificar o efeito de um programa de exercícios físicos multifuncionais no desempenhode capacidades e habilidades motoras de pessoas com deficiência física. Participaram do estudo 10 pessoas com deficiência física (cadeirantes), de ambos os sexos (média de idade de 43,6±10,31 anos). Os participantes responderam um questionário de anamnese e tiveram suas capacidades motoras avaliadas por meio dos seguintes testes: tempo de reação da mão; velocidade de 20 metros e resistência de força de membros superiores. O programa de exercícios multifuncionais foi desenvolvido em oito semanas, com frequência de duas sessões semanais, com duração de 90 minutos cada sessão. Os resultados apontaram significativa melhora com relação ao desempenho no tempo de reação em 66% dos participantes; além disso, 50% melhoraram sua velocidade sobre a cadeira de rodas e 86% melhoraram a resistência de força de membros superiores. Assim, pode-se dizer que o programa foi eficiente em melhorar as capacidades físicas avaliadas.

O Genocídio Armênio (1914-1916), reconhecido por alguns estudiosos como o protótipo do genocídio moderno, é negado até hoje pelo governo turco, apesar dos protestos da comunidade armênia dispersa em todo o mundo. Oficialmente, a Turquia reconhece que ocorreram muitas mortes, mas nega a intenção estatal do ato genocida. Na mesma época ou até mesmo um pouco antes, os gregos a outra grande minoria cristã do Império Otomano também sofreram massacres e perseguições, com um saldo de centenas de milhares de mortos, vivenciando situações semelhantes às sofridas pelos armênios. Sob este mesmo viés, movimentos nacionalistas e imperialistas europeus levaram à perda significativa de territórios do Império Otomano, forçando, em consequência, a mobilização de centenas de milhares de muçulmanos que, fugindo do domínio cristão, instalaram-se na Anatólia, fortalecendo as questões etno-religiosas. Hoje, essas histórias seguem sendo motivo de questionamento, ainda que esquecidas ou silenciadas por alguns grupos. O objetivo deste estudo é contribuir para a elucidação desta polêmica, reunindo um conjunto de informações que permita uma compreensão mais ampla do assunto. Com base na historiografia especializada no tema, procuramos inventariar e comparar as versões de diversos autores, cujos discursos são complementares ou mesmo antagônicos, bem como a posição oficial do governo turco, postada no site do Ministério das Relações Internacionais da Turquia. Somam-se aqui os testemunhos de sobreviventes e as declarações de diplomatas e missionários estrangeiros que presenciaram os acontecimentos. The Armenian Genocide (1914-1916), recognized by some scholars as the prototipe of the modern genocide, is denied by the turkish government even today, despite the protests of the armenian community around the world. Officially, Turkey recognizes that many people died in the period, but denies the genocidal intent. At the same time or little before. The greeks the other major minority of the Ottoman Empire also suffered with massacres and persecutions, resulting in hundreds of thousands dead, experiencing similar situations as those suffered by the Armenians. In the same period, nationalist and imperialist movements led to great losses of territory of the Ottoman Empire, forcing, as a result, the mobilization of hundreds of thousands of muslims, escaping from the Christian rule, who settled at Anatólia, stressing the etno-religious conflicts. Today, those stories are still a reason to argue, even if forgotten or silenced by some groups. The intention of this work is help on the elucidation of the polemica, collecting a set of informations that may allow a wider understanding of the subject. Using the specialized historiography, we tried to catalogue and compare the many opinions of authors, whose speeches are complementary or even opposing, as well as the official version of the Turkish government, posted at the Ministery of Foreign Affairs website. Here is added the voices of the survivors and the statements of foreign missionaries and diplomats, who witnessed the events.

A free water surface wetland was built in 2002 to treat wastewater from a tool factory containing metals (Cr, Ni, Zn and Fe), nutrients and organic matter. Until 2006, the last reported period, the wetland retained metals and stored them primarily in the bottom sediment and in the biomass of macrophytes secondarily. The aim of this work was to study metal retention and distribution in the sediment of a constructed wetland for industrial wastewater treatment. Total concentrations and fractions (exchangeable, carbonate-bound, Fe–Mn oxides-bound, organic matter-bound and residual) of metals in sediment were analyzed in this treatment wetland, in order to estimate the fate of metals over time. Metal concentrations were significantly higher in the inlet than in the outlet sediment; concentrations in the latter remained without significant differences throughout the testing period. Metal concentrations and redox potential decreased with depth within the sediment. The lowest metal concentrations and pH and the highest redox values were attained in spring, in agreement with the period of maximum macrophyte growth. Ni and Zn were mainly stored associated with the carbonate fraction; Cr was mainly associated with the Fe–Mn oxides fraction, while Fe was mainly associated with the residual fraction, probably as pyrite. The incoming wastewater composition containing high pH, carbonate, calcium and Fe concentrations favored the observed association in the surface sediment. It would be expected that sediment will continue retaining metals in fractions that will not release them into the water while the chemical and environmental conditions remain unchanged.

Background: The selection of patients for genetic testing to rule out Lynch syndrome is currently based on fulfilment of at least one of the revised Bethesda criteria followed by mismatch repair (MMR) status analysis. A study was undertaken to compare the present approach with universal MMR study-based strategies to detect Lynch syndrome in a large series of patients with colorectal cancer (CRC). Methods: 2093 patients with CRC from the EPICOLON I and II cohorts were included. Immunohistochemistry for MMR proteins and/or microsatellite instability (MSI) analysis was performed in tumour tissue. Germline MLH1 and MSH2 mutation analysis was performed in patients whose tumours showed loss of MLH1 or MSH2 staining, respectively. MSH6 genetic testing was done in patients whose tumours showed lack of MSH6 expression or a combined lack of MSH2 and MSH6 expression but did not have MSH2 mutations. PMS2 genetic testing was performed in patients showing isolated loss of PMS2 expression. In patients with MSI tumours and normal or not available MMR protein expression, all four MMR genes were studied. Results: A total of 180 patients (8.6%) showed loss of expression of some of the MMR proteins and/or MSI. Four hundred and eighty-six patients (23.2%) met some of the revised Bethesda criteria. Of the 14 (0.7%) patients who had a MMR gene mutation, 12 fulfilled at least one of the revised Bethesda criteria and two (14.3%) did not. Conclusions: Routine molecular screening of patients with CRC for Lynch syndrome using immunohistochemistry or MSI has better sensitivity for detecting mutation carriers than the Bethesda guidelines. Instituto de Salud Carlos III (INT09/208 and PI08/0726). Fundación de la CV para la Investigación en el Hospital General Universitario de Alicante. Grant SAF 07-64873 from the Ministerio de Educación y Ciencia. Funds from the AGAUR (2009 SGR 849) Instituto de Salud Carlos III (FI07/00303) CIBERehd is funded by the Instituto de Salud Carlos III. Grant from Conselleria d’Educació de la Generalitat Valenciana (VALi+d).

The PTPN22 locus is one of the strongest risk factors outside of the major histocompatability complex that associates with autoimmune diseases. PTPN22 encodes lymphoid protein tyrosine phosphatase (Lyp) which is expressed exclusively in immune cells. A single base change in the coding region of this gene resulting in an arginine to tryptophan amino acid substitution within a polyproline binding motif associates with type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosis, Hashimotos thyroiditis, Graves disease, Addison’s disease, Myasthenia Gravis, vitiligo, systemic sclerosis juvenile idiopathic arthritis and psoriatic arthritis. Here, we review the current understanding of the PTPN22 locus from a genetic, geographical, biochemical and functional perspective.

Introducao: Avaliacoes fisicas sao necessarias para se propor treinamento fisico, particularmente numa periodizacao de treinamento no futsal feminino, tema sobre o qual ha poucos estudos. Este estudo teve como objetivo verificar a alteracao cardiorrespiratoria (VO2maximo) e o indice de massa corporea (IMC) numa periodizacao de treinamento de jogadoras de futsal feminino adulto da Universidade Norte do Parana. Materiais e Metodos: A amostra foi composta por 12 jogadoras de futsal feminino da categoria adulta (idade=23±4 anos), nivel nacional. Apos a leitura e assinatura do termo de consentimento livre e esclarecido, calculou-se o IMC e foi utilizado o Shuttle Run Test, proposto por Leger e Lambert. Resultados: O IMC nao variou significativamente (p=0,93) entre os periodos competitivos, apresentando uma discreta diminuicao de 0,31±0,02%; quanto ao VO2maximo, houve alteracao significativa (p=0,0005), correspondendo a 8,31±0,06% de um periodo para o outro. A correlacao entre VO2maximo e o IMC, por sua vez, nao foi significativa (p=0,28; p=0,15). Discussao: Os dados obtidos nos levam a inferir que as atletas nao alteraram significativamente o IMC; no entanto, melhoraram a sua condicao cardiorrespiratoria, respondendo de forma positiva aos estimulos do treinamento.

The intersection of language education and special education is not clearly marked for linguistically and culturally diverse students; some qualify as English language learners; others as English language learners with disabilities or specific language impairment; still others with only disabilities or specific language impairment. It is often perplexing to try to decipher which category is most appropriate and, consequently, how best to serve these students. Assessment data, if reliable and valid, coupled with historical information, can help define the pathway to educational success for the fastest growing segment of our school population. This article shares the challenges facing educators of English language learners and attempts to show how proper assessment can guide educational decision making. We pose that for English language learners, assessment must entail the gathering of information from multiple sources on their language proficiency and academic achievement in both English and their native language. In that way, we obtain a comprehensive portrait of the students' full complement of knowledge and skills. Ultimately, English as a Second Language or bilingual teachers working along with speech-language pathologists need to collaborate in the collection, analysis, and interpretation of data to afford English language learners optimal opportunities for success in school.

The aim of this work was to compare Cr(III) and Cr(VI) removal kinetics from water by Pistia stratiotes and Salvinia herzogii. The accumulation in plant tissues and the effects of both Cr forms on plant growth were also evaluated. Plants were exposed to 2 and 6 mg L−1 of Cr(III) or Cr(VI) during 30 days. At the end of the experiment, Cr(VI) removal percentages were significantly lower than those obtained for Cr(III) for both macrophytes. Cr(III) removal kinetics involved a fast and a slow component. The fast component was primarily responsible for Cr(III) removal while Cr(VI) removal kinetics involved only a slow process. Cr accumulated principally in the roots. In the Cr(VI) treatments a higher translocation from roots to aerial parts than in Cr(III) treatments was observed. Both macrophytes demonstrated a high ability to remove Cr(III) but not Cr(VI). Cr(III) inhibited the growth at the highest studied concentration of both macrophytes while Cr(VI) caused senescence. These results have important implications in the use of constructed wetlands for secondary industrial wastewater treatment. Common primary treatments of effluents containing Cr(VI) consists in its reduction to Cr(III). Cr(III) concentrations in these effluents are normally below the highest studied concentrations in this work. Fil: Maine, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Hadad, Hernán Ricardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Sánchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Caffaratti, Sandra Ester. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina Fil: Pedro, María del Carmen. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analitica; Argentina

This contribution summarizes the nutrient and metal removal of a free water surface constructed wetland, compares it with the previous small-scale prototype and discusses the observed differences. Several locally available macrophyte species were transplanted into the wetland. Eichhornia crassipes (water hyacinth) showed a fast growth and it soon became dominant, attaining 80% cover of the wetland surface. Typha domingensis (cattail) and Panicum elephantipes (elephant panicgrass) developed as accompanying species attaining 14 and 4% cover. The wetland removed 86% of Cr and 67% of Ni. Zn concentrations were below 50 μg l−1 in most samplings. The FeS precipitation probably caused the high retention of Fe (95%). The outcoming water was anoxic in most samplings. Phosphate and ammonium were not retained within the wetland while 70% and 60% of the incoming nitrate and nitrite were removed. Large denitrification losses are suggested. Cr, Ni and Zn were retained by the macrophytes in the larger wetland and in sediment in the small-scale one. Differences in the retention mechanism of the two wetlands are discussed.

The synthesis, characterization, and electrochemical study of the Zn(II)–Al(III) and Zn(II)–Cr(III) Layered Double Hydroxides (LDHs) containing 2-thiopenecarboxylate as the interlayer anions are described. The LDHs were prepared by the constant pH coprecipitation technique followed by hydrothermal treatment for 72 h. The materials were analyzed by PXRD, FT-IR, 13 C CP-MAS, EDX, TEM, and CV. The presence of the organic heterocyclic anions was confirmed by FT-IR and the related solid-state 13 C NMR data strongly suggested that these were dimerised during coprecipitation. Accordingly, the basal spacing found by the X-ray technique was ∼15.3 A, a distance coincident with the formation of bilayers of the intercalated anions. The structural organization of all the new materials was greatly enhanced by hydrothermal treatment, as shown by PXRD. The improved organization of the bilayered structures had a strong influence in the electrochemical behaviour of clay-modified electrodes produced with these materials, such as the diminished resistance to the ionic flow through the LDHs films.

An on-line method for the determination of airborne organophosphate esters based on dynamic sonication-assisted solvent extraction and large-volume injection (LVI) gas chromatography with nitrogen-phosphorous detection is introduced. The LVI is performed with a programmed-temperature vaporizer. The entire extracted fraction of 800 microl (hexane-methyl-tert.-butyl ether, 7:3, v/v) is introduced directly into the GC system without any clean-up step following extraction. The extraction and analysis step were completed in less than 15 min. The limit of detection of the investigated organophosphate esters was established to be in the range of 5-32 pg/filter. The correlation coefficients (r2) were investigated in the linear range study of the entire system and established to be approximately 0.9900 for all the investigated organophosphates esters. Applications of the method was demonstrated with the extraction of air samples collected onto glass fiber filters from different indoor environments. Six organophosphate esters were found at the levels 0.4-138 ng/m3.

The competition between 2'-deoxyguanosine (dG) and water has been quantitatively evaluated for the allylic carbocation derived from tamoxifen and for the stabilized diarylmethyl cation (bis-(4-methoxyphenyl)methyl). Both systems were examined by the competition kinetics method, in which the products were quantitatively analyzed after the SN1 solvolysis of the corresponding acetate esters in aqueous solutions containing the nucleoside. The principal product of the reaction of both cations with dG is the adduct at the NH2 group, a characteristic of delocalized carbocations. The tamoxifen cation was also examined by laser flash photolysis, with absolute rate constants for the reaction with dG and water being obtained and converted into rate constant ratios. The principal result of this study is that there is a three orders of magnitude difference in the reactivity of these cations towards the neutral form of dG and its conjugate base. Under acidic conditions where the reaction occurs with neutral dG, the guanine–water selectivity is low. Even at relatively high concentrations of dG, the majority of the product is alcohol derived from the water reaction. At pH 10 to 11, in contrast, dG is present as the anion and this is highly competitive. Yields of adduct as high as 90% can be attained. A consequence of the large difference in reactivities is that at neutral pH the majority of the reaction of the cation with dG is actually occurring via the small amount of conjugate base present. A further feature of the results is that the NH2 adduct is the predominant stable product from the anion. To explain the high rate constant for the reaction forming this product, a mechanism is proposed whereby one of the protons of the NH2 group is transferred to N1 as the N2-cation bond is forming.Key words: guanine, DNA adduct, carbocation, tamoxifen.

The effect of exposure of Eichhornia crassipes to Cr (III) was assessed by measuring changes in photosynthetic pigments, malondialdehyde, superoxide dismutase, glutathione reductase, catalase, and guaiacol peroxidase activities, as well as Cr concentration in tissues. Cr concentration in roots was significantly higher than in aerial parts and increased with Cr concentration in water. Photosynthetic pigments increased significantly, whereas the activities of antioxidant enzymes varied differently in plant tissues. Low Cr concentrations induced a rapid response of E. crassipes during short-term exposure, implying that the antioxidant system conferred redox homeostasis. Results showed that Cr (III) was more toxic at the two highest concentrations and long-term exposure, while it was not harmful but beneficial at the two lowest concentrations and short-term exposure. This work concludes that E. crassipes was able to grow under Cr (III) stress by protecting itself with an increase in the activity of its antioxidant system. Fil: González, César Iván. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Maine, Maria Alejandra. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina Fil: Cazenave, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentina Fil: Sanchez, Gabriela Cristina. Universidad Nacional del Litoral. Facultad de Ingeniería Química. Laboratorio de Química Analítica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Benavides, Maria Patricia. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Química Biológica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina

The tamoxifen carbocation (Ph(Ar)C=CPh-CH+-CH3, Ar = 4-Me2NCH2CH2OC6H4) is generated from acetate and sulfate precursors by SN1 ionization in water. The cation exists in (E) and (Z) forms which equilibrate before reaction. The major products are the α-hydroxytamoxifens Ph(Ar)C=CPh-CHOH-CH3, both (E) 64% and (Z) 29%, with the ratio independent of the configuration of the starting ester. Two minor products with a total yield of 7% account for the rest of the products. These have been characterized as indenes derived from intramolecular cyclization, a 4.5% yield of the indene derived from cyclization into the Ar ring with 2.5% due to cyclization into the phenyl ring. Experiments in acid solutions (0.01-0.1 M HCl) starting with pure (E)- or (Z)-α-hydroxytamoxifen reveal that the two alcohols equilibrate. This occurs by H+-catalyzed formation of the carbocation followed by water capture. Occurring about 10-fold slower than this isomerization is an irreversible process resulting in the two indenes. This cyclization will result in the destruction of the α-hydroxytamoxifens upon exposure to acidic conditions and also makes the direct observation of the tamoxifen carbocation under super-acid conditions difficult, if not impossible. The indenes do form in low yield whenever the tamoxifen carbocation is generated from an SN1 precursor. Thus these products could serve as markers for the formation of the tamoxifen carbocation in cellular systems or in in vivo experiments.Key words: carbocation, indene, allylic cation, isomerization.

The structure and the rheology of systems resulting from heating at 80°C isoelectric solutions of bovine serum albumin (BSA) in the concentration range 10–200mg/ml were studied. Small-angle neutron scattering measurements view the systems as being formed of large aggregates of micrometric size with a close packed arrangement of denatured protein molecules. No indication of a fractal structure stands out. The viscoelastic behaviour is linear up to about 5% strain, except in the BSA concentration range 30–90mg/ml where the linearity limit is below 1% strain. The viscoelastic response was analysed in the linear domain, or as close as possible to it, by combining the results of dynamic and creep recovery measurements. The dependence on concentration of the steady state viscosity, of the steady state compliance, and of the average retardation time shows a marked change around a concentration C0∼50mg/ml, corresponding probably to a percolation threshold.

When aqueous suspensions of gold nanorods are irradiated with a pulsing laser (808 nm), pressure waves appear even at low frequencies (pulse repetition rate of 25 kHz). We found that the pressure wave amplitude depends on the dynamics of the phenomenon. For fixed concentration and average laser current intensity, the amplitude of the pressure waves shows a trend of increasing with the pulse slope and the pulse maximum amplitude. We postulate that the detected ultrasonic pressure waves are a sort of shock waves that would be generated at the beginning of each pulse, because the pressure wave amplitude would be the result of the positive interference of all the individual shock waves.