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This work presents a systematic study of the swelling behavior of a lecithin lamellar phase incorporating different amounts of the short peptide sequence diphenylalanine (FF). Small- and wide-angle X-ray scattering assays provide relevant information about the structure and elasticity of the lamellar stacking. These data show that important changes occur at the interface of the lipid membrane dependent not only on the peptide content but also on the hydration of the lamellar structure. Multilamellar-to-unilamellar transitions, previously observed for an increasing number of peptides, are now observed to be dependent on the hydration of the lamellar phase. Wide-angle X-ray scattering and electron microscopy observations (TEM) provide experimental evidence of peptide aggregation into long amylogenic fibers. We argue that aggregates that partition in water may become large enough to destabilize the lamellar structure. It is also shown that, for a given peptide concentration, the lamellar structure can be rendered more flexible or more rigid, by tuning the hydration.

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In the present work, we investigate the effect of two short phenylalanine-based peptides on lipid membranes. A simplified model membrane composed of lecithin vesicles was used to incorporate different amounts of the two amino acid sequences, the dimmer l,l-diphenylallanine (FF) and the trimmer cysteine-diphenylallanine (CFF). Spectroscopic and scattering techniques were applied to probe in detail the structural behavior of lipid membranes in the presence of the peptides. The experimental results demonstrate that both peptides are located mainly at the interface of the membrane interacting with phosphate groups modifying membrane thickness and flexibility. The multilamellar structure of the vesicles is preserved with inclusion of small amounts of FF, accompanied by changes in membrane thickness and elasticity. Finally, a multi- to unilamellar transition is observed as a result of peptide self-association into a crystalline structure onto the membrane interface.

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AIM: The aim of the present study was to evaluate the protective effect of the neodymium:yttrium-aluminum-garnet (Nd:YAG) laser and acidic phosphate fluoride (APF) on enamel erosion caused by hydrochloric acid. METHODS: Fifty human enamel specimens were distributed according to the following treatments (n = 10): untreated (control), APF (1.23%) 4 min, Nd:YAG laser (100 mJ, 1 W, 10 Hz, 141.5 J/cm2 ), APF + Nd:YAG laser, and Nd:YAG laser + APF. For 14 days the specimens were submitted to erosive challenge: 5 min in 3 mL hydrochloric acid (0.01 M, pH 2.2), rinsed with distilled water, and stored in artificial saliva for 3 h. This cycle was repeated four times per day. The calcium (Ca) loss was determined in demineralizing solution by atomic emission spectroscopy, and superficial roughness (Ra) was measured before and after the erosive challenge. RESULTS: The mean Ca loss was (mg/L, ± standard deviation): control 12.74 ± 3.33, APF 1.71 ± 0.11, laser 1.64 ± 0.08, APF + laser 1.38 ± 0.08, and laser + APF 1.48 ± 0.07. Kruskal-Wallis test showed a significant difference between the control and other groups. APF + laser showed minor loss of Ca. After the erosive challenge, the APF + laser group showed Ra alteration. CONCLUSION: A significant reduction in tooth dissolution was observed after fluoride application combined with Nd:YAG irradiation.

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Fifty two doctors (22 male, 30 female) got a degree in Ethology in 2010, according to a previous study; 46 curricula vitae (21 male, 25 female), 88% of the initial group, provided career information at Plataforma Lattes database during a life-span of six years. Employability was high, at least 90% for both sexes. 48% of doctors work at the public sector, holding stable jobs; 40% are professors at public universities. Fellowships provide 10 positions (19%), and the private sector nine jobs (17%); mostly at private universities (15%). Men occupy the majority of positions at public universities (14 of 21, representing 67%), while most women are holding positions at the private sector or as public servants outside professorship (nine out of 13, corresponding to 69%). 70% of fellowship holders are women. 96% advised or are advising academic works. 89% of all are co-authors of at least one peer-reviewed article: a total of 366 reports (male= 166, female= 170; 61 articles.year-1; 1.5 article.year-1.doctor-1). 56% of doctors graduate at Institutions located in the Southeast region, where most graduation programs are. A clear regional transference of doctors is observed when employment is considered, in this case the participation of the Southeast region shrinks to 30%. This indicates a role played by the Southeast region as disseminator of animal behavior knowledge within Brazil. This opens the possibility of an equitable relationship among regions in Brazil concerning higher education in Ethology. It is foreseen a positive effect upon the knowledge of the particular fauna of Brazilian regions, diverse and numerous, and mostly unknown from the ethological point of view. In our sample women are in slightly greater number than men, and are involved in mentoring and publishing, as well as men. Most females holding doctorate in Ethology work in less stable jobs (at private institutions or holding temporary fellowships) and probably endure less favorable conditions regarding research and remuneration. Not surprisingly this is the scenario seen in 30 out of 35 countries of the Organisation for Economic Co-operation and Development community, including in countries like USA and Germany. So it is not enough just to support accessibility; special attention should be given to assure fair working conditions for all. Our data also show a favorable scenario for Ethology in Brazil, mostly associated with the public educational system that is tuition-free and dependent of governmental resources. Recent governmental cutbacks for Science and Technology may curb further expansion of Ethology in Brazil

Cinquenta e dois doutores(as) (22 masculino, 30 feminino) defenderam teses em Etologia em 2010, de acordo com um estudo prévio; 46 curricula vitae (21 masculino, 25 feminino), 88% do grupo inicial, forneceram informações a partir de consulta à base de dados da Plataforma Lattes, durante seis anos. A empregabilidade foi alta, de pelo menos 90% para ambos os sexos. 48% dos doutores(as) trabalham no setor público, e têm empregos estáveis; 40% são professores(as) em universidades públicas. Dez posições são ocupadas por bolsistas (19%), e o setor privado é responsável por nove empregos (17%); a maioria deles em universidades privadas (15%). Homens ocupam a maioria das posições nas universidades públicas (14 de 21, representando 67%), enquanto que a maioria das mulheres tem posição no setor privado ou são servidoras públicas não docentes (nove de 13, correspondendo a 69%). Setenta por cento dos pesquisadores bolsistas são mulheres. 96% supervisionaram ou estão supervisando trabalhos acadêmicos. A maioria (89%) é coautor(a) de pelo menos um artigo peer-reviwed: um total de 366 publicações (masculino= 166, feminino= 170; 61 artigos.ano-1; 1,5 artigos.ano-1.autor-1). 56% dos doutores fizeram Pós Graduação em Instituições do sudeste brasileiro, onde a maioria dos programas de Pós Graduação está situada. Observa-se uma clara transferência regional de doutores quando se considera os empregos ocupados, nesse caso a participação do sudeste se reduz a 30%. Este dado indica que o sudeste pode ser considerado um disseminador de conhecimentos sobre comportamento animal dentro do Brasil. É possível se antever um futuro de relações de maior igualdade entre as regiões brasileiras em relação ao ensino superior de Etologia. Efeitos positivos são previstos com relação ao conhecimento de faunas muito particulares das regiões brasileiras, que são diversas e numerosas, além de majoritariamente pouco conhecidas do ponto de vista etológico. Na presente amostra as mulheres estão ligeiramente mais representadas em número do que os homens, e estão envolvidas em atividades de orientação e publicação, tanto quanto os homens. Entretanto, a maioria das doutoras trabalha em empregos menos estáveis (em instituições privadas ou como bolsistas temporárias), e provavelmente convivem com condições menos favoráveis tanto com relação à pesquisa e à remuneração. Não surpreendentemente este é o cenário visto em 30 dos 35 países da Organisation for Economic Co-operation and Development, inclusive em países como os Estados Unidos e a Alemanha. Não é suficiente, portanto, aumentar a acessibilidade; atenção especial deve ser dispensada de maneira a assegurar condições adequadas de trabalho para todos(as). Os dados também mostram um cenário favorável para a Etologia no Brasil, principalmente no sistema público de educação, que é isento de taxas e dependente de fundos governamentais. Cortes recentes no orçamento governamental da Ciência e Tecnologia podem interferir com a continuidade da expansão da Etologia no Brasil

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We investigate the behavior of multilamellar phases composed of lecithin and a commercial cosurfactant (Simusol), which is a mixture of ethoxylated fatty acids. Using X-ray scattering and a new procedure to fit the data, relevant parameters characterizing the lamellar structure were determined as a function of membrane composition, varying from 100% of lecithin to 100% of Simulsol. Scattering data illustrating the swelling of the lamellae for different amounts of cosurfactant are presented with the respective behavior of the Caillé parameter. With this experimental approach, we show that the incorporation of ethoxy brushes onto the lipid surface enhances repulsive interactions arising from membrane fluctuations and changes the interactions at the interface between bilayers.

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Lignocellulosic residues are interesting materials for the production of heavy metal adsorbents for aquatic systems. Whole fibers taken from coconut (Cocos nucifera) husks were functionalized with the thiophosphoryl (P=S) group by means of the direct reaction with Cl(3)PS, (CH(3)O)(2)ClP=S or (CH(3)CH(2)O)(2)ClP=S in order to obtain an adsorptive system for 'soft' metal ions, particularly Cd(2+). These functionalized fibers (FFs) were characterized by means of elemental analysis, infrared spectroscopy, thermal analysis and acid-base titration. Adsorption isotherms for Cd(2+) fitted the Langmuir model, with binding capacities of 0.2-5 m mol g(-1) of FF at 25 degrees C.

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OBJECTIVES: To evaluate the effect of laser irradiation (LI) on the glycemic state and the histological and ionic parameters of the parotid and submandibular glands in rats with diabetes. METHODS: One hundred twenty female rats were divided into eight groups. Diabetes was induced by administration of streptozotocin and confirmed later according to results of glycemia testing. Twenty-nine days after the induction, the parotid and submandibular glands of the rats were irradiated with 5, 10, and 20 J/cm2 using a laser diode (660 nm/100 mW) (without diabetes: C5, C10, and C20; with diabetes: D5, D10, and D20, respectively). On the following day, the rats were euthanized, and blood glucose determined. Histological and ionic analyses were performed. RESULTS: Rats with diabetes without irradiation (D0) showed lipid droplets accumulation in the parotid gland, but accumulation decreased after 5, 10, and 20 J/cm2 of laser irradiation. A decrease in fasting glycemia level from 358.97+/-56.70 to 278.33+/-87.98 mg/dL for D5 and from 409.50+/-124.41 to 231.80+/-120.18 mg/dL for D20 (p<0.05) was also observed. CONCLUSION: LI should be explored as an auxiliary therapy for control of complications of diabetes because it can alter the carbohydrate and lipid metabolism of rats with diabetes.

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The aim was to evaluate the performance of DIAGNOdent [laser fluorescence(LF) and LFpen] devices enhanced by fluorescent dye in detecting mineral loss around brackets and comparing the inhibitory effect of bonding material on artificial demineralization, and to verify whether LF methods show the same trends of mineral loss. Brackets were bonded to premolar halves with Fuji Ortho LC, Transbond XT, and Ortho Glass LC cements (n = 15). The teeth were soaked in demineralizing solution (pH = 4.8) for 16 days. Mineral loss was calculated by atomic emission spectrometry, and lesions were measured with LF devices with dye [tetrakis N-methylpyridyl porphyrin (TMPyP)]. Groups were compared with regard to LF readings and mineral loss, and performance of caries detection was calculated. Higher mineral loss and LF-TMPyP values occurred in the resin group. LFpen-TMPyP readings were significantly higher in the demineralized groups. Correlation was observed between mineral loss and LF measurements. LF methods are capable of identifying lower demineralization around brackets bonded with resin-modified glass ionomer cements.

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Trinomys yonenagae é um rato-de-espinho endêmico de dunas fixas na Caatinga. Estes animais vivem em colônias, cavam e compartilham túneis, apresentando altos níveis de tolerância intra e intergrupal. No presente trabalho testamos se fêmeas exibem preferência por um parceiro de longa convivência em um teste de escolha, onde cada fêmea estava livre para se locomover e os machos (o parceiro e um desconhecido) estavam restritos aos seus próprios compartimentos. Agressões ocorreram uma única vez, contra um macho desconhecido. Todas as fêmeas gastaram mais tempo em um compartimento com um macho do que no compartimento vazio, confirmando o alto grau de afiliação de T. yonenagae. Consideramos que houve escolha, uma vez que 70% das fêmeas preferiram repousar lado-a-lado mais tempo com o parceiro, do que com o macho desconhecido. Contudo, as frequências de visita a ambos os machos não foram estatisticamente diferentes. Considerando que a ausência de dimorfismo, a presença de cuidado parental, a maturação sexual tardia e a afiliação heterossexual, esta apontada no presente estudo, são todas características de monogamia social, sugerimos que T. yonenagae é socialmente monogâmico e que o relacionamento entre fêmeas e machos nesta espécie aparenta ser um balanço complexo entre estratégias de preferências por parceiros e de evitar parentescos.