68 research outputs found
Preliminary in vitro evaluation of the anti-proliferative activity of guanylhydrazone derivatives
Guanylhydrazones have shown promising antitumor activity in preclinical tumor models in several studies. In this study, we aimed at evaluating the cytotoxic effect of a series of synthetic guanylhydrazones. Different human tumor cell lines, including HCT-8 (colon carcinoma), MDA-MB-435 (melanoma) and SF-295 (glioblastoma) were continuous exposed to guanylhydrazone derivatives for 72 hours and growth inhibition of tumor cell lines and macrophages J774 was measured using tetrazolium salt (MTT) assay. Compounds 7, 11, 16 and 17 showed strong cytotoxic activity with IC50 values lower than 10 ÎŒmol Lâ1 against four tumor cell lines. Among them, 7 was less toxic to non-tumor cells. Finally, the obtained data suggest that guanylhydrazones may be regarded as potential lead compounds for the design of novel anticancer agents
Kinetics of mass loss of arabica coffee during roasting process
Roasting is one of the most complex coffee processing steps due to simultaneous transfers of heat and mass. During this process, beans lose mass because of fast physical and chemical changes that will set color and flavor of the commercial coffee beverage. Therefore, we aimed at assessing the kinetics of mass loss in commercially roasted coffee beans according to heating throughout the processing. For that, we used samples of 350-g Arabica coffee processed grains with water content of 0.1217 kga kg-1, in addition to a continuous roaster with firing gas. The roaster had initial temperatures of 285, 325, 345 and 380 °C, decreasing during the process up to 255, 285, 305 and 335 °C respectively. Mass loss was calculated by the difference between grain weight before and after roasting. We observed a linear variation directly dependent on roaster temperature. For each temperature during the process was obtained a constant mass loss rate, which was reported by the Arrhenius model with r2 above 0.98. In a roaster in non-isothermal conditions, the required activation energy to start the mass loss in a commercial coffee roasting index was 52.27 kJ mol -1.A torrefação Ă© uma das etapas mais complexa do processamento do cafĂ© devido Ă
transferĂȘncia simultĂąnea de calor e massa, em que os grĂŁos perdem massa devido Ă rapidez das
mudanças fĂsicas e quĂmicas, necessĂĄrias para produzir a cor e o aroma do cafĂ© comercial. Assim,
objetivou-se com este trabalho determinar a cinética da perda de massa dos grãos de café torrados
comercialmente em função da temperatura do processo. Foram usadas amostras de 350 g de grãos
beneficiados de café aråbica com teor de ågua de 0,1217 kga kg-1
. Usou-se um torrador com queima
de gĂĄs constante e temperaturas iniciais de 285; 325; 345 e 380 °C, que diminuĂram durante a
operação até equilibrar-se em 255; 285; 305 e 335 °C, respectivamente. A perda de massa foi
calculada a partir do peso dos grãos antes e depois da torração, sendo observada uma variação linear
dependente diretamente da temperatura do torrador. Para cada temperatura do processo, foi obtida
uma taxa constante de perda de massa, que foi relacionada pelo modelo de Arrhenius com r2
acima
de 0,98. Em condiçÔes não isotérmicas do torrador, a energia de ativação necessåria para iniciar a
perda de massa, em Ăndices de torração comercial do cafĂ©, foi 52,27 kJ mol-1
.Universidad de Costa Rica/[]/UCR/Costa RicaConselho Nacional de Desenvolvimento CientĂfico e TecnolĂłgico/[]/CNPq/BrasilCoordenação de Aperfeiçoamento de Pessoal de NĂvel Superior/[]/CAPES/ BrasilFundação de Amparo Ă Pesquisa do Estado de Minas Gerais/[]/FAPEMIG/BrasilUCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS
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Globalisation from Above? Corporate Social Responsibility, the Workers' Party and the Origins of the World Social Forum
In its assessment of the origins and early development of the World Social Forum this article challenges traditional understandings of the Forum as representing âglobalisation from belowâ. By tracing the intricate relations among elements of business, civil society, and the Workersâ Party in the first years of the Forum, this article reveals the major role played by a corporate movement stemming from the Brazilian democratisation process in the 1980s, and how this combined with the transformed agenda of the Workersâ Party as it gained higher political offices to constrain the Forumâs activities from the outset. In so doing, this article challenges not only widespread conceptions of the Forum as a counterâhegemonic alternative but also current critiques concerning its subsequent limitations. Furthermore, it reveals how traditional understandings of the World Social Forum and of global civil society are underpinned by flawed assumptions which typecast political activities in the global âSouthâ
Conservação de cafĂ© torrado e moĂdo durante o armazenamento. Parte 2: Massa especĂfica e porosidade
The determination of physical properties is an important factor in the design of machinery
and the scaling of post-harvest operations. The present study evaluates the influence of the
level of roasting and the size of grinding on the physical properties of coffee during storage.
The following physical properties were evaluated: true and bulk density, and intergranular
porosity. Raw coffee beans (Coffea canephora and Coffea arabica), hulled and dried, were
roasted to two different levels: medium light (SCAA#65) and moderately dark (SCAA#45).
The beans were then grinded into three different sizes: fine (0.59 mm), medium (0.84 mm)
and coarse (1.19 mm). An additional coffee lot was kept whole. Following grinding, samples
were stored at two different temperatures (10 and 30 ÂșC) and analyzed after five different
storage durations (0, 30, 60, 120 and 180 days). The medium light roast had higher values
for each of the measured physical properties. Finely ground samples had higher true and
bulk densities, and porosities. It is concluded that the size of grinding, level of roasting and
duration of storage significantly affect the physical properties of coffee.A determinação das propriedades fĂsicas Ă© fator importante na formulação de projetos
de maquinårios e dimensionamento de operaçÔes pós-colheita. De forma a permitir o
dimensionamento correto e o uso desses maquinĂĄrios, objetivou-se avaliar e determinar,
durante o armazenamento, as propriedades fĂsicas: massa especĂfica unitĂĄria e aparente e
porosidade intergranular, alĂ©m de avaliar a influĂȘncia dos nĂveis de torrefação e moagem
sobre essas propriedades. Grãos de café cru (Coffea canephora e Coffea arabica) foram
utilizados, descascados e secados e sĂł entĂŁo torrados em dois nĂveis: mĂ©dia clara (SCAA#65) e
moderadamente escura (SCAA#45). Os grĂŁos foram moĂdos em trĂȘs granulometrias: fina (0,59
mm), média (0,84 mm) e grossa (1,19 mm), além do lote de café inteiro. Realizada a moagem as
amostras foram armazenadas em duas temperaturas (10 e 30 ÂșC) e analisadas em cinco tempos
distintos de armazenamento (0, 30, 60, 120 e 180 dias). A torra média clara permitiu maiores
valores das propriedades fĂsicas; jĂĄ as amostras de granulometria fina apresentaram aumento
das massas especĂfica unitĂĄria e aparente e porosidade. Conclui-se que a granulometria, o
nĂvel de torrefação e o tempo de armazenamento, afetaram as propriedades fĂsicas do cafĂ©.National Council for Scientificand Technological Development/[CNPq nÂș 14/2012]/CNPq/BrasilUCR::VicerrectorĂa de InvestigaciĂłn::Unidades de InvestigaciĂłn::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS
Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats
Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV
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