60 research outputs found

    Alternative and simple normal-phase HPLC enantioseparation of a chiral amino acid-type spin label derivative

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    In this work an alternative chromatographic process was developed for fractionating the (+)-(3R,4R) and ( - )-(3S,4S) enantiomers of the chiral trans β-amino acid trans-2,2,5,5-tetramethylpyrrolidine-3-amino-4-carboxylic acid (POAC), which was protected at its amine group for further coupling to a peptide, polymer or other macromolecule. The HPLC enantioseparation was achieved using a chiral cellulose-based normal stationary phase and isocratic elution. The n-hexane:isopropanol system, always with greater amount of the former component, was used as mobile phase as revealed by improved fractionation property of both components, demonstrated by the separation factor and resolution index values. These parameters presented values of 3.7 and 18.4 and of 2.0 and 6.7 when in 90:10 (v/v) and 80:20 (v/v) n-hexane:isopropanol solutions, respectively. These findings indicate that the one-step chromatographic purification strategy using normal-phase is feasible, thus opening the perspective of a fast large-scale production this paramagnetic spin probe.Neste trabalho desenvolveu-se um processo alternativo para separação cromatográfica dos enantiômeros (+)-(3R,4R) e ( - )-(3S,4S) do β-aminoácido quiral trans-2,2,5,5-tetrametilpirrolidina-3-amino-4-carboxílico (POAC), que estava protegido no grupo amínico para posterior ligação a um peptídeo, polímero ou outra macromolécula. A enantioseparação foi obtida por HPLC usando uma fase estacionária normal à base de celulose quiral e eluição isocrática. O sistema n-hexano:isopropanol, sempre com maior quantidade do primeiro solvente, foi usado como fase móvel, pois forneceu os melhores resultados na separação dos dois componentes, constatado pelos valores mais elevados de fator de separação e de índice de resolução cromatográfica. Estes parâmetros apresentaram valores de 3,7 e 18,4 e de 2,0 e 6,7 nas soluções com proporção 90:10 (v/v) e 80:20 (v/v) de n-hexano:isopropanol, respectivamente. Estes dados indicam que a estratégia de purificação cromatográfica em uma única etapa usando fase normal é viável, abrindo assim a perspectiva de uma produção rápida e em grande escala desta sonda paramagnética.18401845Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

    The Advertisement Calls and Distribution of Two Sympatric Species of \u3cem\u3eChiasmocleis\u3c/em\u3e (Méhely 1904) (Anura, Microhylidae, Gastrophryninae) from the Atlantic Forest

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    The advertisement calls of Chiasmocleis cordeiroi and C. crucis are described for populations from the municipalities of Igrapiúna and Camacan, respectively, state of Bahia, Brazil. Both calls consist of multipulsed notes produced in series. Differences between the two calls are: dominant frequency, higher in C. cordeiroi (range 4500-4898 Hz; C. crucis range 4069-4435 Hz); note rate, higher in C. cordeiroi (range 6.20--7.46 s/note; C. crucis range 5.17-5.59 s/note); pulse rate, higher in C. cordeiroi (151.82-194.83 s/note; C. crucis range 125.30- 142.12 s/note); and the structure of the modulation patterns of the notes. Moreover, the advertisement calls of C. crucis and C. cordeiroi are more similar than the calls of all syntopic congeners. Furthermore, the current distribution of both species was extended

    PARTITION OF DRY BIOMASS AND NUTRIENT IN MINISTUMPS OF Eucalyptus INFLUENCED BY NPK FERTILIZATION

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    O estado nutricional da planta-matriz \ue9 de grande import \ue2ncia para a manuten\ue7\ue3o do seu vigor vegetativo, o que determina a produ\ue7\ue3o de brotos e tamb\ue9m os \uedndices de enraizamento e velocidade de forma\ue7\ue3o das ra\uedzes, uma vez que os macronutrientes e os micronutrientes est\ue3o envolvidos nos processos bioqu\uedmicos e fisiol\uf3gicos vitais \ue0 planta. Nesse sentido, o objetivo deste trabalho foi avaliar a influ\ueancia da aduba\ue7\ue3o NPK sobre a parti\ue7\ue3o de biomassa seca e nutriente em minicepa de eucalipto em solu\ue7\ue3o nutritiva. O trabalho foi realizado de novembro de 2008 a janeiro de 2009, em casa de vegeta\ue7\ue3o. Foi utilizado delineamento inteiramente casualizado em esquema fatorial fracionado (4x4x4)\ubd, perfazendo 32 tratamentos com tr\ueas repeti\ue7\uf5es. Os tratamentos se constitu\uedram de quatro doses dos nutrientes de N (50; 100; 200 e 400 mg L-1) na forma de ureia, P (7,5; 15; 30 e 60 mg L-1) na forma de \ue1cido fosf\uf3rico e K (50; 100; 200 e 400 mg L-1) na forma de cloreto de pot\ue1ssio em solu\ue7\ue3o nutritiva. Houve efeito significativo apenas para as doses de N isoladamente, para a biomassa seca das miniestacas e biomassa seca da parte a \ue9rea e raiz das minicepas com efeito linear decrescente, com o aumento das doses de N. A dose de 50 mg L-1 de N proporcionou maior ac\ufamulo de biomassa seca das miniestacas e minicepas. A distribui\ue7\ue3o percentual da biomassa seca e dos nutrientes na biomassa seca das miniestacas, parte a \ue9rea e ra \uedzes das minicepas variou em rela\ue7\ue3o \ue0s doses de N. A extra\ue7\ue3o de macronutrientes pelas miniestacas de 6 cm na dose de 50 mg L-1 de N seguiu a seguinte ordem decrescente de N > S > P > K > Ca > Mg e micronutrientes de Cu > B > Mn > Fe > Zn.The nutritional status of the matrix plant has a great importance for the maintenance of its vegetative vigor, which determines the sprouts production and also the rooting percentage and the speed of root formation, since the macro and micronutrients are involved in biochemical and physiological vital processes for the plant. Thus, this study aimed to evaluate the influence of NPK fertilizer on dry biomass production by minicuttings and mini-stumps and the percentage distribution of nutrients in a simple hybrid plant of Eucalyptus urophylla in nutrient solution. The experiment was realized from November, 2008 to January, 2009 in a vegetation environment. The experimental design was a completely randomized in factorial scheme with a fractional factorial (4x4x4)1/2, adding up to 32 treatments with three replicates. The treatments consisted of four levels nutrients of nitrogen (50, 100, 200 and 400 mg L-1) in the urea form, P (7.5, 15, 30 and 60 mg L-1) in the phosphoric acid form and K (50, 100, 200 and 400 mg L-1) in the potassium chloride form, in the nutrient solution. There was significant effect only to the N doses to the dry mass of mini-cuttings and the dry mass of shoots and roots of mini-stumps with decreasing linear effect against N doses increasing. The doses of 50 mg.L-1 of N promoted higher accumulation of dry mass in mini-cuttings and mini-stumps. The percentage distribution of dry mass and of the nutrients in dry mass of mini-stumps, shoots and roots of mini-stumps varied in relation to N doses. Macronutrients extraction from mini-stumps of 6 cm at a dose of 50 mg L-1 of N followed the order of decreasing N > S > P > K > Ca > Mg and micronutrients Cu > B > Mn > Fe >Zn

    Bicistronic DNA vaccines simultaneously encoding HIV, HSV and HPV antigens promote CD8⁺ T cell responses and protective immunity

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    Millions of people worldwide are currently infected with human papillomavirus (HPV), herpes simplex virus (HSV) or human immunodeficiency virus (HIV). For this enormous contingent of people, the search for preventive and therapeutic immunological approaches represents a hope for the eradication of latent infection and/or virus-associated cancer. To date, attempts to develop vaccines against these viruses have been mainly based on a monovalent concept, in which one or more antigens of a virus are incorporated into a vaccine formulation. In the present report, we designed and tested an immunization strategy based on DNA vaccines that simultaneously encode antigens for HIV, HSV and HPV. With this purpose in mind, we tested two bicistronic DNA vaccines (pIRES I and pIRES II) that encode the HPV-16 oncoprotein E7 and the HIV protein p24 both genetically fused to the HSV-1 gD envelope protein. Mice i.m. immunized with the DNA vaccines mounted antigen-specific CD8⁺ T cell responses, including in vivo cytotoxic responses, against the three antigens. Under experimental conditions, the vaccines conferred protective immunity against challenges with a vaccinia virus expressing the HIV-derived protein Gag, an HSV-1 virus strain and implantation of tumor cells expressing the HPV-16 oncoproteins. Altogether, our results show that the concept of a trivalent HIV, HSV, and HPV vaccine capable to induce CD8⁺ T cell-dependent responses is feasible and may aid in the development of preventive and/or therapeutic approaches for the control of diseases associated with these viruses.CNPqINCTVFAPESPUS

    Short-Term Analysis of Human Dental Pulps After Direct Capping with Portland Cement

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    This study evaluated the short-term response of human pulp tissue when directly capped with Portland cement. In this series of cases, twenty human third molars that were scheduled for extraction were used. After cavity preparation, pulp exposure was achieved and Portland cement pulp capping was performed. Teeth were extracted after 1, 7, 14 and 21 days following treatment and prepared for histological examination and bacterial detection. Each group had 5 teeth. The results were descriptively analysed. Dentin bridge formation was seen in two teeth with some distance from the material interface (14 and 21 days). Soft inflammatory responses were observed in most of the cases. Bacteria were not disclosed in any specimen. PC exhibited some features of biocompatibility and capability of inducing mineral pulp response in short-term evaluation. The results suggested that PC has a potential to be used as a less expensive pulp capping material in comparison to other pulp capping materials

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

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    Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt
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