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1.
Anim Genet ; 42(1): 89-92, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20528846

RESUMO

Brazilian Santa Inês (SI) sheep are very well-adapted to the tropical conditions of Brazil and are an important source of animal protein. A high rate of twin births was reported in some SI flocks. Growth and Differentiation Factor 9 (GDF9) and Bone Morphogenetic Protein 15 (BMP15) are the first two genes expressed by the oocyte to be associated with an increased ovulation rate in sheep. All GDF9 and BMP15 variants characterized, until now, present the same phenotype: the heterozygote ewes have an increased ovulation rate and the mutated homozygotes are sterile. In this study, we have found a new allele of GDF9, named FecG(E) (Embrapa), which leads to a substitution of a phenylalanine with a cysteine in a conservative position of the mature peptide. Homozygote ewes presenting the FecG(E) allele have shown an increase in their ovulation rate (82%) and prolificacy (58%). This new phenotype can be very useful in better understanding the genetic control of follicular development; the mechanisms involved in the control of ovulation rate in mammals; and for the improvement of sheep production.


Assuntos
Fator 9 de Diferenciação de Crescimento/genética , Ovulação , Ovinos/genética , Animais , Proteína Morfogenética Óssea 15/genética , Feminino , Prole de Múltiplos Nascimentos/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Ovinos/fisiologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-17981081

RESUMO

The aim of this work is to present results derived from experimental IR and UV spectra and theoretical studies of DPCH, in order to get a more deeper insight on the physicochemical properties of this compound to gain a more deep knowledge of its action, helping in the design of new compounds with antimalaric effects. Experimental results are analyzed on the basis of theoretical calculations, which allow to derive suitable interpretations of spectral data.


Assuntos
Cicloexanonas/química , Oxigênio/química , Peróxidos/química , Compostos de Espiro/química , Modelos Moleculares , Conformação Molecular , Espectrofotometria Infravermelho , Eletricidade Estática , Vibração
3.
Artigo em Inglês | MEDLINE | ID: mdl-17331797

RESUMO

The influence of temperature and solvent effects on the stability of the complex formed by two molecules of 1,2-dihydroxybenzene and one molecule of AlCl3 were experimentally and theoretically studied, by means of UV spectroscopic methods and Density Functional Theory methods. The changes of the stability constant with the temperature were analyzed using the van't Hoff equation, while the variations with the permittivity of the reaction medium were explained with an equation proposed by us. The experimental and theoretical data obtained allowed proving that the increase in the hydrogen-bond donor ability of the solvents favors a higher thermodynamic stability of the reactants with respect to the complex and, therefore a decrease in the corresponding stability constant. The non-planar structure proposed for the 2:1 ligand-metal complex is coherent with the small batochromic shift experimentally observed. In the complex molecule, the planes containing the phenyl rings are tilted by approximately 89 degrees with each other. It was concluded that the complexation reaction is an endothermic process in which the solvent-solute interactions play an essential role.


Assuntos
Alumínio/química , Catecóis/química , Compostos Organometálicos/química , Estabilidade de Medicamentos , Solventes , Espectrofotometria Ultravioleta , Temperatura , Termodinâmica
4.
Eur J Clin Nutr ; 71(12): 1393-1398, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28561039

RESUMO

BACKGROUND/OBJECTIVES: To examine compensatory changes in sedentary behavior (SB) and light-intensity physical activities (LIPA) in response to a 22-week exercise training program in overweight/obese adults; and to determine if different forms of exercise training and physical activity recommendations interact with these compensatory changes. SUBJECTS/METHODS: Eighty-nine overweight and obese individuals (body mass index (BMI): 25-34.9 kg/m2, 48% males), aged 18-50 years, were randomized into four intervention groups (strength, endurance, combined strength + endurance and physical activity recommendations) with a 25-30% caloric restriction of total daily energy expenditure for 22 weeks. Energy expenditure was measured by accelerometry before, during and after the program. RESULTS: LIPA increased significantly (P<0.001) after three months and at the end of intervention compared to baseline (pre: 281±9 min; 3 months: 303±9 min; post: 312±8 min). SB percentage decreased by 5.3 at the end of the intervention (P=0.002). No interactions were observed between groups or sexes. Significant correlations were found between SB and body weight, fat mass, android fat mass and lean body mass before and after the intervention (P<0.05). LIPA was also significantly correlated with all these body composition variables in the pre-intervention, but only correlated with body weight at the end of intervention. CONCLUSIONS: There were no compensatory changes after a combined exercise and diet program; where minutes in LIPA increased and %SB decreased after the program, without differences among exercise modes. Greater physical activity levels can contribute to a better percentage and distribution of body tissues.


Assuntos
Terapia por Exercício/métodos , Obesidade/terapia , Sobrepeso/terapia , Comportamento Sedentário , Acelerometria , Adolescente , Adulto , Composição Corporal , Índice de Massa Corporal , Peso Corporal , Restrição Calórica , Dieta , Metabolismo Energético , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Redução de Peso , Adulto Jovem
5.
SAR QSAR Environ Res ; 28(9): 749-763, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28965425

RESUMO

The ANTARES dataset is a large collection of known and verified experimental bioconcentration factor data, involving 851 highly heterogeneous compounds from which 159 are pesticides. The BCF ANTARES data were used to derive a conformation-independent QSPR model. A large set of 27,017 molecular descriptors was explored, with the main intention of capturing the most relevant structural characteristics affecting the studied property. The structural descriptors were derived with different freeware tools, such as PaDEL, Epi Suite, CORAL, Mold2, RECON, and QuBiLs-MAS, and so it was interesting to find out the way that the different descriptor tools complemented each other in order to improve the statistical quality of the established QSPR. The best multivariable linear regression models were found with the Replacement Method variable sub-set selection technique. The proposed QSPR model improves previous reported models of the bioconcentration factor in the present dataset.


Assuntos
Biodegradação Ambiental , Compostos Orgânicos/química , Relação Quantitativa Estrutura-Atividade , Modelos Lineares , Modelos Químicos , Conformação Molecular , Medição de Risco
6.
Artigo em Inglês | MEDLINE | ID: mdl-16442838

RESUMO

We report the experimental preparation of the 1,3-butanal-1,2,4,5-tetroxane by oxidation of glutataldehyde with oxygen peroxide in presence of concentrated sulfuric acid, following the Bayer and Viller method modified by Jorge et al. The UV and IR spectra are studied from the experimental and theoretical standpoint. A rather complete vibrational assignment was performed and the nature of the electronic transitions was discussed in detail.


Assuntos
Aldeídos/química , Tetraoxanos/química , Tetraoxanos/síntese química , Espectrofotometria Infravermelho , Espectrofotometria Ultravioleta
7.
Acta Trop ; 164: 290-296, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27640323

RESUMO

The selection of oviposition sites by females of Aedes (Stegomyia) aegypti is a key factor for the larval survival and egg dispersion and has a direct influence in vector control programs. In this study, we evaluated the aspects of reproductive physiology of Ae. aegypti mosquitoes tested in the presence of raw sewage. Ae. aegypti females were used in oviposition bioassays according to two methodologies: (i) choice assay, in which three oviposition substrates were offered in the same cage: treatment (raw sewage), positive control (distilled water) and negative control (1% sodium hypochlorite) and; (ii) no choice assay, in which only one substrate was available. The physicochemical and microbiological analysis of the raw sewage used in this study indicated virtually no levels of chlorine, low levels of dissolved oxygen and high levels of nitrogenous compounds as well as the presence of Escherichia coli and total fecal coliforms. After 72h of oviposition, the eggs were counted and there was no statistically significant difference (p>0.05) in the oviposition rate between raw sewage and positive control in both methodologies. In addition, females were dissected to evaluate egg-retention and also there were no appreciable differences in egg retention even when raw sewage was the only substrate offered. The data also showed that egg hatching and larvae development occurred normally in the raw sewage. Therefore, the present study suggests that Ae. aegypti can adapt to new sites and lay eggs in polluted water, such as the raw sewage. These findings are of particular importance for the control and surveillance programs against Ae. aegypti in countries where the conditions of poor infrastructure and lack of basic sanitation are still an issue.


Assuntos
Aedes/fisiologia , Cruzamento/métodos , Oviposição/fisiologia , Esgotos/parasitologia , Adaptação Fisiológica , Animais , Feminino , Larva/crescimento & desenvolvimento , Oócitos/fisiologia , Água
8.
ScientificWorldJournal ; 3: 636-9, 2003 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-12920305

RESUMO

The results of a theoretical study on the structure of some diborane(4) compounds are presented in order to analyze the issue related to the relative stabilities of the 1,1- vs. 1,2-isomers. Through the employment of the molecular mechanics method, characteristic distances and angles are given and they are compared with available experimental data. In order to rationalize the results, the different energy components are discussed in a comparative fashion. We find a rather satisfactory agreement between theoretical and experimental data. Some possible future extensions are pointed out to complement this sort of analysis.

9.
ScientificWorldJournal ; 1: 897-905, 2001 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-12805723

RESUMO

Experimental and theoretical results for retention index of a set of 20 beta-diketones are given. The quantitative structure-chromatographic retention relationships (QSRR) theory is employed and six molecular descriptors are chosen to compute the fitting polynomials. Multiple regression analysis yields satisfactory results when one resorts to several variables equations, instead of computing just one-variable formulae. Average absolute deviations from experimental results are rather low, which seems to point out the suitability of the present approach.


Assuntos
Alcanos/química , Cetonas/química , Propano/análogos & derivados , Propano/química , Relação Quantitativa Estrutura-Atividade , Alcanos/análise , Cromatografia Gasosa/métodos , Cromatografia Gasosa/estatística & dados numéricos , Modelos Químicos , Modelos Estatísticos , Estrutura Molecular , Projetos de Pesquisa/estatística & dados numéricos , Termodinâmica
10.
ScientificWorldJournal ; 2: 455-60, 2002 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12806029

RESUMO

We report the results obtained for the experimental determination and the theoretical calculation of the enthalpy of formation of 3,6-diphenyl-1,2,4,5-tetroxane molecule. The experimental work was performed using a macrocalorimeter to measure the combustion heat, and the sublimation enthalpy was determined via the measurement of the vapor pressure at equilibrium with the vapor phase at different temperatures resorting to the Clapeyron-Claussius equation. Theoretical calculations were performed using semiempirical AM1 and PM3 methods as well as ab initio techniques at the 3-21, 6-31G(d,p), and 6-311G(d,p) basis set levels.


Assuntos
Tetraoxanos/química , Termodinâmica , Fenômenos Químicos , Físico-Química , Modelos Químicos , Tetraoxanos/síntese química
11.
Rev Soc Bras Med Trop ; 34(5): 421-8, 2001.
Artigo em Português | MEDLINE | ID: mdl-11600907

RESUMO

This study evaluates the prevalence and viability of helminth eggs and protozoan cysts in sludge obtained by anaerobic treatment in four treatment stations in Curitiba, Parana State, Brazil. The parasites observed were helminths: Ascaris sp (85%), Toxocara sp (5.5%), Trichuris sp (4.5%), Hymenolepis diminuta (3.7%), H. nana (1%) and Taenia sp (0.4%), protozoan: Isospora sp, Entamoeba coli, Entamoeba histolytica, Giardia lamblia, Endolimax nana. In biological treatment based on the anaerobic digestion the effectiveness depends on the duration and temperature. The treatment showed efficiency for pathogen reduction of between 59.7 to 93%. However, the number of helminth eggs found in treatment stations was still high and new higher performance treatment is necessary for land application or for other objectives, seeking to reduce the risks for human and animal health.


Assuntos
Helmintos/crescimento & desenvolvimento , Contagem de Ovos de Parasitas , Esgotos/parasitologia , Anaerobiose , Animais , Técnicas de Laboratório Clínico/métodos
12.
Mini Rev Med Chem ; 12(10): 936-46, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22303974

RESUMO

This article reviews multi-criteria QSAR applications on Acetylcholinesterase inhibitors as palliative drugs for Alzheimer's Disease, published in the period 2001-2011. It includes QSAR models for different series of compounds, comparative studies, and advances in methodologies. This period is marked by a shift in focus from palliative treatment to pathogenesis. However, we believe that research into palliative treatment should continue. More comparative studies are desirable. In order to facilitate comparative and general studies on Acetylcholinesterase inhibitors, a standard experimental protocol for measuring an inhibitor's potency is needed. Finally, we recommend chemists to work closely with system and molecular biologists.


Assuntos
Acetilcolinesterase/metabolismo , Doença de Alzheimer/tratamento farmacológico , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Relação Quantitativa Estrutura-Atividade , Doença de Alzheimer/enzimologia , Animais , Inibidores da Colinesterase/uso terapêutico , Humanos
13.
Mini Rev Med Chem ; 12(10): 959-70, 2012 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-22420574

RESUMO

CNS drug development is characterized by an especially high attrition rate, despite clear unmet medical needs in the field of neuro-pharmacology and significant investment in R of novel CNS drug treatments. Here, we overview the issues underlying the intrinsic difficulty of CNS drugs development, including obstacles of pharmacokinetic nature and lack of predictivity of preclinical tests. We highlight current efforts to overcome these limitations, with an emphasis on modeling opportunities towards early recognition of CNS candidates (stressing the possibilities of multi-target directed ligands or "magic shotguns") and different approaches to improve CNS bioavailability.


Assuntos
Fármacos do Sistema Nervoso Central/química , Fármacos do Sistema Nervoso Central/farmacologia , Doenças do Sistema Nervoso Central/tratamento farmacológico , Descoberta de Drogas/métodos , Animais , Sistema Nervoso Central/efeitos dos fármacos , Desenho Assistido por Computador , Humanos
17.
J Chem Theory Comput ; 2(3): 775-81, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-26626682

RESUMO

In a previous report, the approximate crystalline structure and electronic structure of a novel, hypothetical hexagonal carbon allotrope has been disclosed. Employing the approximate extended Hückel method, this C structure was determined to be a semiconducting structure. In contrast, a state-of-the-art density functional theory (DFT) optimization reveals the hexagonal structure to be metallic in band profile. It is built upon a bicyclo[2.2.2]-2,5,7-octatriene (barrelene) generating fragment molecule and is a Catalan network, with the Wells point symbol (6(6))2(6(3))3 and the corresponding Schläfli symbol (6, 3.4). As the network is entirely composed of hexagons and, in addition, possesses hexagonal symmetry, lying in space group P6/mmm (space group #191), it has been given the name hexagonite. The present report describes a density functional theory (DFT) optimization of the lattice parameters of the parent hexagonite structure, with the result giving the optimized lattice parameters of a = 0.477 nm and c = 0.412 nm. A calculation is then reported of a simple diffraction pattern of hexagonite from these optimized lattice parameters, with Bragg spacings enumerated for the lattice out to fourth order. Results of a synchrotron diffraction study of carbon nanotubes which underwent cold compression in a diamond anvil cell (DAC) to 100 GPa, in which the carbon nanotubes have evidently collapsed into a hitherto unknown hexagonal C polymorph, are then compared to the calculated diffraction pattern for the DFT optimized hexagonite structure. It is seen that a close fit is obtained to the experimental data, with a standard deviation over the 5 matched reflections being given by σx = 0.003107 nm/reflection.

18.
Rev. bras. anal. clin ; 43(2): 131-134, 2011. tab, ilus
Artigo em Português | LILACS | ID: lil-605687

RESUMO

0 aumento significativo do número de casos notificados da Leishmaniose Tegumentar Americana (LTA) e a expansão geográfica da endemia tem motivado o desenvolvimento de novas tecnologias para auxiliar no diagnóstico das leishmanioses, visando minimizar as restrições apresentadas pelos testes diagnósticos disponíveis nos serviços de saúde. 0 presente trabalho empregou imunocitoquimica e imunohistoquímica (ICQ/IHQ) como métodos diagnósticos laboratoriais para LTA. Amostras de culturas de Leishmania in vitro e cortes histológicos de lesões em animais infectados experimentalmente foram submetidos a ICQ/IHQ, utilizando anticorpos policlonais desenvolvidos para este estudo e o complexo avidina-biotina modificado (Ultra Streptavidin®). Em comparação com outras técnicas empregadas para o diagnóstico da LTA, nos casos avaliados, a IHQ apresentou resultados semelhantes aos da histopatologia com coloração HE, com sensibilidade de 33,3% para formas amastigotas. Quando considerada a presenva de antígenos de Leishmania no padrão celular, a IHQ apresentou uma sensibilidade de 83,3%, significativamente maior que na histopatologia e compatível com metodos padrão ouro de cultura e PCR. As metodologias de ICQ/IHQ desenvolvidas neste trabalho foram capazes de demonstrar em biópsias de lesões, a presença de formas amastigotas e antígenos de Leishmania, oferecendo contribuição adicional ao diagnóstico da LTA, sendo de facil aplicação e podendo ser utilizada no sistema público de saúde.


The significant increase in cutaneous leishmaniasis (CL) notified cases and the geographic expansion of this endemy has motivated the development of new techniques to help in leishmaniasis diagnosis, seeking the minimization of the restrictions imposed by the diagnostic tests available at the health services. The current study applied immunocytochemistry and immunohystochemistry methods (ICC/IHC) for laboratory diagnosis of CL. Imprints and histological sections from tissue infected with Leishmania were submitted to ICC/IHC methods using polyclonal antibodies developed for this study and a modified avidin-biotin complex (Ultra Streptavidin®). The samples also were submitted for routinely stained hematoxylin and eosin (H&E) specimens and gold standard methods (culture and PCR). Compared with other useful techniques for the CL diagnosis, ICC/IHC showed the same sensitivity results (33%) as H&E stain for amastigotes recognition. When the presence of Leishmania antigens was evaluated, ICC/IHC presented 83,3% sensitivity, i.e., higher than that detected by histopathology and equivalent with gold standard methods (culture and PCR). The ICC/IHC techniques developed in the current study were able to recognize amastigote forms and also Leishmania antigens in lesion biopsies, offering an additional help to CL diagnosis and it can be easily applied in the public health system.


Assuntos
Técnicas de Laboratório Clínico , Imuno-Histoquímica , Leishmaniose Tegumentar Difusa/diagnóstico , Avidina , Biópsia , Biotina
19.
Bioorg Med Chem ; 13(20): 5826-9, 2005 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-15990317

RESUMO

A thermochemical a rather simple experimental technique method, is used to determine the enthalpy of the formation of 3,6-dibutanoic-1,2,4,5-tetroxane. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6-311G basis set level. Some possible extensions of the present procedure are pointed out.


Assuntos
Calorimetria/métodos , Tetraoxanos/química , Termodinâmica
20.
J Org Chem ; 66(9): 3129-32, 2001 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-11325278

RESUMO

The reactions of 4-nitrophenyl, 2,4-dinitrophenyl, and 2,4,6-trinitrophenyl methyl carbonates (NPC, DNPC, and TNPC, respectively) with substituted phenoxide ions are subjected to a kinetic study in water at 25.0 degrees C, ionic strength 0.2 M (KCl). Production of the leaving groups (the nitro derivatives) is followed spectrophotometrically. Under excess of the phenoxide ions pseudo-first-order rate coefficients (k(obsd)) are found throughout. Plots of k(obsd) vs substituted phenoxide concentration at constant pH are linear, with the slope (k(N)) independent of pH. The Brönsted-type plots (log k(N) vs pK(a) of the phenols) are linear with slopes beta = 0.67, 0.48, and 0.52 for the phenolysis of NPC, DNPC, and TNPC, respectively. The magnitudes of these Brönsted slopes are consistent with a concerted mechanism. In the particular case of the phenolysis of NPC the expected hypothetical curvature center of the Brönsted plot for a stepwise mechanism should be pK(a)(0) = 7.1 (the pK(a) of 4-nitrophenol). This curvature does not appear within the pK(a) range of the substituted phenols studied (5.3--10.3), indicating that these reactions are concerted. The phenolysis of DNPC and TNPC should also be concerted in view of the even more unstable tetrahedral intermediates that would be formed if the reactions were stepwise. The reactions of the same substrates with pyridines are stepwise, which means that substitution of a pyridine moiety in a tetrahedral intermediate by a phenoxy group destabilizes the intermediate perhaps to the point of nonexistence. The k(N) values for the title reactions are larger than those for the concerted phenolysis of the corresponding ethyl S-aryl thiolcarbonates. The k(N) values found in the present reactions are subjected to a dual regression analysis as a function of the pK(a), of both the nucleophile and leaving group, the coefficients being beta(N) = 0.5 and beta(lg) = -0.3, respectively. These coefficients are consistent with a concerted mechanism.

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