970 resultados para 6K-957-CG
Resumo:
Sediment sampling was performed at the center of the clam colony. Immediately after sample recovery onboard, the sediment core was sub-sampled and preserved for later analyses. Pyrite and carbonate content of the sediment was measured by X-ray refraction analysis as previously described (Ertefai et al., 2010).
Resumo:
Sediment samples were collected from the rim of a large vesicomyid clam colony in the Japan Deep Sea Trench. Immediately after sample recovery onboard, the sediment core was sub-sampled for ex situ rate measurements. Sulfate reduction were measured ex situ by the whole core injection method with three replicates. We incubated the samples at in situ temperature (1.5°C) for 48 hours with carrier-free 35SO4 (dissolved in water, 50 kBq). Sediment was fixed 20 ml ZnAc solution (20%, w/v) for AOM or SR. Turnover rates were measured as previously described (Kallmeyer et al., 2004).
Resumo:
Oxygen penetration depth and temperature at the rim of the clam colony was measured with a small deep-sea microprofiler module (Treude et al., 2009), carrying 3 oxygen Clark-type microelectrodes (Revsbech et al., 1980) and one temperature sensor (Pt100, UST Umweltsensorentechnik GmbH, Germany). High-resolution microprofiles across the sediment-water interface were measured with a vertical resolution of 100 µm on a total length of 15 cm. Oxygen electrodes had a linear response to the oxygen concentration in seawater and were calibrated in situ using constant readings in the bottom water (oxygen concentration determined by Winkler titration) and the anoxic parts of the sediment.
Resumo:
Utilizando cromatografia gás-espectrometria de massa (CG/EM) com computador, descreve-se os constituintes voláteis do óleo essencial das sementes de puxuri (Licaria puchury-major). Identificaram-se nove monoterpenos na mistura, além de safrol, eugenol, metileugenol e ácido dodecanóico, citados previamente.
Resumo:
Foram avaliadas as alterações nas características estruturais de ácidos húmicos (AH) decorrentes da adição de matéria orgânica de resíduos urbanos. Os AH foram extraídos da camada superficial (0-20 cm) de um Argissolo Vermelho-Amarelo (Seropédica, RJ) e de um Latossolo Vermelho Amarelo (Piraí, RJ), ambos tratados com o equivalente a 80 t ha-1 (em base seca) de composto de lixo urbano e lodo de estação de tratamento de esgotos. O tempo de incubação em laboratório foi de 24 semanas à temperatura ambiente e umidade mantida na capacidade de campo. Para caracterizar os AH, foram utilizadas a análise elementar, a ressonância magnética nuclear (RMN) de 13C e Pirólise acoplada à cromatografia gasosa e a espectrometria de massas (Pi-CG/EM). A análise de RMN 13C permitiu observar alterações na composição molecular dos AH de forma clara, principalmente, pelo aumento do teor de C mono e di oxigenados (δC 50-110) e pela diminuição dos teores de grupos CH2 e CH3 (δC 50-110). O aumento no teor de carboidratos evidencia a presença de estruturas mais lábeis nos AH com adição dos resíduos. Em adição, a técnica de Pi-CG/EM permitiu verificar diferenças qualitativas significativas nos compostos orgânicos, provenientes da fragmentação térmica dos AH com incorporação de novas estruturas, sobretudo da fração lipídica e de derivados de carboidratos (furanos), nas amostras de solos tratados com ambos os resíduos orgânicos. O uso em conjunto das técnicas analíticas de RMN 13C e de Pi-CG/EM foi eficiente para avaliar as mudanças na composição molecular de ácidos húmicos decorrentes da adição de resíduos orgânicos de origem urbana.
Resumo:
Cilengitide, a cyclicized arginine-glycine-aspartic acid-containing pentapeptide, potently blocks ανβ3 and ανβ5 integrin activation. Integrins are upregulated in many malignancies and mediate a wide variety of tumor-stroma interactions. Cilengitide and other integrin-targeting therapeutics have preclinical activity against many cancer subtypes including glioblastoma (GBM), the most common and deadliest CNS tumor. Cilengitide is active against orthotopic GBM xenografts and can augment radiotherapy and chemotherapy in these models. In Phase I and II GBM trials, cilengitide and the combination of cilengitide with standard temozolomide and radiation demonstrate consistent antitumor activity and a favorable safety profile. Cilengitide is currently under evaluation in a pivotal, randomized Phase III study (Cilengitide in Combination With Temozolomide and Radiotherapy in Newly Diagnosed Glioblastoma Phase III Randomized Clinical Trial [CENTRIC]) for newly diagnosed GBM. In addition, randomized controlled Phase II studies with cilengitide are ongoing for non-small-cell lung cancer and squamous cell carcinoma of the head and neck. Cilengitide is the first integrin inhibitor in clinical Phase III development for oncology.
Resumo:
The main purpose of this work was the qualitative study of organic compounds in landfill leachate. The samples were collected from a sanitary landfill located at Gravataí, a southern Brazilian city, that receive both, industrial and domestic refuse. The samples were submitted to solid phase extraction (SPE) with XAD-4 resin as the stationary phase. The instrumental analysis was performed by Gas Chromatography with a Mass Spectrometry Detector (GC/MSD). The compounds achieved in the SPE extracts were tentatively identified by the GC/MS library. It was found several oxygen and nitrogen compounds like carboxylic acids, ketones, amines and amides. Sulfur compounds and phthalate esters are also identified.
Resumo:
A headspace solid-phase microextraction (HS-SPME) for the determination of 1,4 dioxane in cosmetics by gas chromatography is described. A manual SPME holder with 85 µm polyacrylate coating is utilized. The method is determined to have good resolution, satisfactory linerity (correlation coefficient r=0.997 for 0.20-10.00 mg Kg-1 range), a relative standard deviation of 6.3% and a detection limit of 5.00 µg Kg-1. Some cosmectic products were analyzed.
Resumo:
Glucocorticosteroids (CT) show a powerful anti-inflammatory effect. In view of this, they are extensively used in sports medicine, but their misuse (systemic administration) can lead to severe injuries on athletes and has been restricted by the IOC in recent years. For GC-MS analysis, a derivatization step is necessary in order to convert them to a stable form, thus preventing thermal breakdown with the loss of the ketone side chain. Derivatization of CT is reviewed and a new approach of silylation is presented for screening of CT in urine.