Thermodynamic study of racemic ibuprofen separation by liquid chromatography using cellulose-based stationary phase

Ibuprofen is a nonsteroidal anti-inflammatory drug (NSAID), also known for its significant antipyretic and analgesic properties. This chiral drug is commercialized in racemic form; however, only S-(+)-ibuprofen has clinical activities. In this paper the effect of temperature change (from 288.15 to 308.15 K) on the ibuprofen resolution was studied. A column ( mm) packed with tris(3,5-dimethylphenylcarbamate) was used to obtain the thermodynamic parameters, such as enthalpy change (), entropy change (), variation enthalpy change (), variation entropy change (), and isoenantioselective temperature (). The mobile phase was a combination of hexane (99%), isopropyl alcohol (1%), and TFA (0.1%), as an additive. The conditions led to a selectivity of 1.20 and resolution of 4.55. The first peak, R-(−)-ibuprofen, presented an enthalpy change of 7.21 kJ/mol and entropy change of 42.88 kJ/K·mol; the last peak, S-(+)-ibuprofen, has an enthalpy change of 8.76 kJ/mol and 49.40 kJ/K·mol of entropy change2016CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQsem informaçã

Pattern recognition of lipase-catalyzed or chemically interesterified fat blends containing n-3 polyunsaturated fatty acids

Research PaperThe feasibility to discriminate among samples of different fat blends prior and after inorganic or lipasecatalyzed interesterification, via pattern recognition techniques [principal component analysis (PCA) and discriminant analysis (DA)], was investigated. Blends I and II, consisting of mixtures of palm stearin, palm kernel oil and a concentrate of triacylglycerols (TAG) rich in n-3 polyunsaturated fatty acids (EPAX 4510TG or EPAX 2050TG) were used. These blends, prior (64 samples) and after interesterification, catalyzed by an immobilized Thermomyces lanuginosa lipase (Lipozyme TL IM, 54 samples) or by sodium methoxide (10 samples), were characterized by their acylglycerol profiles (25 chromatographic peaks) and solid fat content (SFC) at 10, 20, 30 and 35 7C. PCA on the multivariate data (i) showed that the initial samples were characterized by higher SFC and higher contents of high-melting TAG and (ii) suggested two separate clusters of initial and interesterified samples. DA was performed on the multivariate data to determine which of the 29 variables have discriminative power. When the 124 samples, characterized by their acylglycerols, were grouped into (i) initial and interesterified samples of blends I or II (four groups) or (ii) also by the catalyst used (six groups), 98.4% of the samples were correctly classifie

Investigation of Trypanosoma-induced vascular damage sheds insights into Trypanosoma vivax sequestration

Multiple blood-borne pathogens infecting mammals establish close interactions with the host vascular endothelium as part of their life cycles. In this work, we investigate differences in the interactions of three Trypanosoma species: T. brucei, T. congolense and T. vivax with the blood vasculature. Infection with these species results in vastly different pathologies, including different effects on vascular homeostasis, such as changes in vascular permeability and microhemorrhages. While all three species are extracellular parasites, T. congolense is strictly intravascular, while T. brucei is capable of surviving both extra- and intravascularly. Our knowledge regarding T. vivax tropism and its capacity of migration across the vascular endothelium is unknown. In this work, we show for the first time that T. vivax parasites sequester to the vascular endothelium of most organs, and that, like T. congolense, T. vivax Y486 is largely incapable of extravasation. Infection with this parasite species results in a unique effect on vascular endothelium receptors including general downregulation of ICAM1 and ESAM, and upregulation of VCAM1, CD36 and E-selectin. Our findings on the differences between the two sequestering species (T. congolense and T. vivax) and the non-sequestering, but extravasating, T. brucei raise important questions on the relevance of sequestration to the parasite’s survival in the mammalian host, and the evolutionary relevance of both sequestration and extravasation.info:eu-repo/semantics/publishedVersio

Corporate social responsibility in Brazil : a comparative analysis of two paper companies

Thesis (M.C.P.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2004.Includes bibliographical references (leaves 57-62).If being socially responsible can result in short or long-term economic benefits, then why do not all companies adopt corporate social responsibility (CSR) practices? This thesis draws on general assumptions from illustrative examples of two paper companies in Brazil--Aracruz and Riocell-- to answer this question. The two examples suggest that stakeholder pressure, managers' perceptions of the economic benefits of CSR and managers' environmental and social values affect the decisions of companies to adopt corporate social responsibility. In addition, data from these two paper companies indicate that company size and economic and political context explain the variations of CSR practices between Aracruz and Riocell. This study argues that both companies have responded to pressures from stakeholders in different ways. As a result, their corporate social responsibility practices have been different. If the goals of companies are to demonstrate increased commitment to corporate social responsibility and to strengthen these practices, businesses need to focus on extending their actions beyond compliance, and incorporate corporate social responsibility as part of their policies.by Ana Paula M. do Nascimento.M.C.P

Drought response of cowpea (Vigna unguiculata (L.) Walp.) landraces at leaf physiological and metabolite profile levels

Drought threatens the world’s food production, particularly in Sub Saharan Africa low external input and rain fed agricultural systems, where cowpea (Vigna unguiculata (L.) Walp.) is an important food crop. In the context of growing concerns regarding climate changes implications on water availability, this study aimed at 1) to evaluate the drought responses in cowpea landraces with contrasting drought tolerance levels (A55 – high sensitivity; A80 - mild sensitivity; A116 - tolerant), 2) using an integrated physiological (leaf gas exchanges; chlorophyll a fluorescence) and biochemical (photoprotective pigments; RuBisCO activity; primary metabolite profiling) analysis to identify drought tolerance probes, in plants submitted to three water availability levels (well-watered, WW; mild drought, MD; severe drought, SD). A116 plants maintained a better water status under drought, what could justify the higher Pn and Pnmax values in MD, as well as higher photochemical use of energy (reflected in the photochemical quenching (qL) and in the quantum yield of non-cyclic electron transport (Y(II))), and the lower need of photoprotective thermal dissipation mechanisms (given by the non-photochemical quenching (qN), and the quantum yield of regulated energy dissipation at photosystem PSII (Y(NPQ))), in MD and SD plants. Greater declines of net (Pn) and potential (Pnmax) photosynthesis were observed in A55 plants, which frequently showed significant impacts already under MD conditions in most parameters, whereas A80 usually displayed and intermediate behaviour. Still, even A55 showed some acclimation response, regarding photoprotective mechanisms associated with high contents of zeaxanthin, lutein, and carotenes, and high Y(NPQ), and qN values, supporting the absence of an increase in the non-regulated energy dissipation at PSII (Y(NO) did not increased) even in SD plants. Additionally, A55 was not significantly affected in RuBisCO activity, which showed to be quite resilient in cowpea. A primary metabolite profiling, complemented with a partial least square discrimination analysis (PLS-DA), allowed a better separation of A116 and A55 plants according to their degree of drought tolerance. In response to drought, A116 showed the greatest accumulation of most responsive metabolites, 14 in total, with sucrose, fucose, urea, alanine and putrescine being exclusively increased in this genotype, suggesting that they can be candidates as drought tolerance proxies. Other compounds, as proline, valine, isoleucine (among amino acids), and rhamnose and raffinose (among sugars) showed close increase patternsinfo:eu-repo/semantics/publishedVersio

New Vaccine Formulations Containing a Modified Version of the Amastigote 2 Antigen and the Non-Virulent Trypanosoma cruzi CL-14 Strain Are Highly Antigenic and Protective against Leishmania infantum Challenge

Visceral leishmaniasis (VL) is a major public health issue reported as the second illness in mortality among all tropical diseases. Clinical trials have shown that protection against VL is associated with robust T cell responses, especially those producing IFN-gamma. The Leishmania amastigote 2 (A2) protein has been repeatedly described as immunogenic and protective against VL in different animal models; it is recognized by human T cells, and it is also commercially available in a vaccine formulation containing saponin against canine VL. Moving toward a more appropriate formulation for human vaccination, here, we tested a new optimized version of the recombinant protein (rA2), designed for Escherichia coli expression, in combination with adjuvants that have been approved for human use. Moreover, aiming at improving the cellular immune response triggered by rA2, we generated a recombinant live vaccine vector using Trypanosoma cruzi CL-14 non-virulent strain, named CL-14 A2. Mice immunized with respective rA2, adsorbed in Alum/CpG B297, a TLR9 agonist recognized by mice and human homologs, or with the recombinant CL-14 A2 parasites through homologous prime-boost protocol, were evaluated for antigen-specific immune responses and protection against Leishmania infantum promastigote challenge. Immunization with the new rA2/Alum/CpG formulations and CL-14 A2 transgenic vectors elicited stronger cellular immune responses than control groups, as shown by increased levels of IFN-gamma, conferring protection against L. infantum challenge. Interestingly, the use of the wild-type CL-14 alone was enough to boost immunity and confer protection, confirming the previously reported immunogenic potential of this strain. Together, these results support the success of both the newly designed rA2 antigen and the ability of T. cruzi CL-14 to induce strong T cell-mediated immune responses against VL in animal models when used as a live vaccine vector. In conclusion, the vaccination strategies explored here reveal promising alternatives for the development of new rA2 vaccine formulations to be translated human clinical trials

Proteome Analysis of Leptospira interrogans Virulent Strain

Leptospirosis is a worldwide zoonotic infection of human and veterinary concern. Caused by pathogenic spirochetes of the genus Leptospira, the disease presents greater incidence in tropical and subtropical regions. The identification of proteins that could be involved in the bacteria host interactions may facilitate the search for immune protective antigens. We report the proteomic analysis of Leptospira interrogans serovar Pomona virulent strain LPF cultured from kidney and liver of infected hamsters. Total protein extracts were separated by two-dimensional gel electrophoresis (2-DE), 895 spots were analyzed by MALDI-TOF mass spectrometry (MS), and 286 were identified as leptospiral proteins, corresponding to 108 distinct proteins. These proteins are allocated in all the bacterial cell compartments and are distributed in every functional category. Furthermore, the previously described, known outer membrane proteins, OmpL1, LipL21, LipL31, LipL32/Hap-1, LipL41, LipL45, LipL46, LruA/LipL71, and OmpA-like protein Loa22 were all recognized. Most importantly, this research work identified 27 novel leptospiral proteins annotated as hypothetical open reading frames (ORFs). We report for the first time an array of proteins of the Leptospira expressed by virulent, low-passage strain. We believe that our studies, together with the genome data will enlighten our understanding of the disease

SÍNTESE E CARACTERIZAÇÃO DE COPOLÍMEROS A PARTIR DO GLICEROL

Atualmente existe um crescente interesse no desenvolvimento de plásticos biodegradáveis sintetizados a partir de fontes renováveis, devido à preocupação com os impactos ambientais gerados pela extração da matéria-prima para a síntese dos plásticos convencionais e suas baixas velocidades de degradação. Esforços têm sido concentrados no desenvolvimento de materiais com as mesmas propriedades dos plásticos convencionais, mas que sejam biodegradados em um curto intervalo de tempo ao serem descartados no meio ambiente. Este trabalho tem como objetivo sintetizar e caracterizar polímeros a partir do glicerol oriundo da produção de biodiesel, que é uma fonte renovável, para que no futuro sejam utilizados no preparo de plásticos (bio)degradáveis. Neste  trabalho pretende-se, ainda, a caracterização físico-química dos polímeros sintetizados.PALAVRAS-CHAVE: Biodiesel; Glicerol; Polímeros