Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 45
Filtrar
1.
J Fish Dis ; 41(7): 1041-1048, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29770449

RESUMO

Monogeneans are ectoparasites that may cause losses in production and productivity in the aquaculture of Colossoma macropomum. Chemotherapeutics used in aquaculture usually have major adverse effects on fish; hence, the use of essential oils has been considered advantageous, but these are not soluble in water. Thus, the use of nanostructures to enhance water solubility of compounds and improve bioactivity may be very promising. This study investigated the antiparasitic activity of nanoemulsion prepared with Copaifera officinalis oleoresin (50, 100, 150, 200 and 300 mg/L), against monogenean parasites from the gills of C. macropomum. The particle size distribution and zeta potential suggested that a potentially kinetic stable system was generated. The nanoemulsion from C. officinalis oleoresin achieved high efficacy (100%) at low concentrations (200 and 300 mg/L) after 15 min of exposure. This was the first time that a nanoemulsion was generated from C. officinalis oleoresin using a solvent-free, non-heating and low-energy method. Moreover, this was the first time that an antiparasitic against monogeneans on fish gills, based on nanoemulsion of C. officinalis oleoresin, was tested.


Assuntos
Antiparasitários/farmacologia , Caraciformes , Fabaceae/química , Extratos Vegetais/farmacologia , Trematódeos/efeitos dos fármacos , Infecções por Trematódeos/veterinária , Animais , Relação Dose-Resposta a Droga , Emulsões , Doenças dos Peixes/tratamento farmacológico , Doenças dos Peixes/parasitologia , Nanoestruturas/análise , Infecções por Trematódeos/tratamento farmacológico , Infecções por Trematódeos/parasitologia
2.
J Fish Dis ; 41(3): 443-449, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29194663

RESUMO

Outbreaks of diseases pose a major threat to sustainable aquaculture development worldwide. Application of herbal products to combat parasitic diseases provides an alternative approach for sustainable aquaculture. This study investigated the in vitro antiparasitic effects of an oil-in-water nanoemulsion prepared using the essential oil from Pterodon emarginatus, against monogeneans infesting Colossoma macropomum. Gill arches from C. macropomum (47.6 ± 14.5 g and 13.5 ± 1.4 cm) that were naturally parasitized by Anacanthorus spathulatus, Notozothecium janauachensis and Mymarothecium boegeri were immersed in different dispersions of the P. emarginatus nanoemulsions (0, 50, 100, 200, 400 and 600 mg/L). The major compounds presented in the essential oil of P. emarginatus were ß-elemene, ß-caryophyllene and α-humulene. Characterization of these nanoemulsions showed that they have a small mean droplet size and low polydispersity index, which is concordant with stable systems. In this in vitro trial, the P. emarginatus nanoemulsion concentrations of 100, 200, 400 and 600 mg/L presented 100% helminthic efficacy against monogeneans of the gills of C. macropomum. The highest two concentrations used (400 and 600 mg/L) were seen to immobilize the parasites after only 15 min. Therefore, it would be worthwhile testing these concentrations in therapeutic baths against monogeneans of C. macropomum.


Assuntos
Anti-Helmínticos/farmacologia , Caraciformes , Fabaceae/química , Doenças dos Peixes/prevenção & controle , Óleos Voláteis/farmacologia , Trematódeos/efeitos dos fármacos , Infecções por Trematódeos/veterinária , Animais , Emulsões , Doenças dos Peixes/parasitologia , Nanoestruturas/análise , Infecções por Trematódeos/parasitologia , Infecções por Trematódeos/prevenção & controle
3.
Climacteric ; 18(2): 311-5, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25263313

RESUMO

OBJECTIVE: To investigate the possible association between periodontal changes and osteoporosis in postmenopausal women through a longitudinal study. METHODS: This longitudinal study included 33 patients. The participants were divided into three groups according to the bone mineral density assessed in the lumbar region: normal bone (G1, n = 15), osteopenia (G2, n = 12) and osteoporosis (G3, n = 6). Periodontal evaluation included clinical attachment level, probing depth, gingival bleeding index and visible plaque index, evaluated by two examiners blinded to systemic bone condition. The statistical process included the t-test for paired samples, with a significance level of 5% to check for changes in periodontal parameters considered at initial and final systemic bone density. RESULTS: The results showed that, after follow-up, there was a significant increase in gingival bleeding index in the group of women who had normal initial bone condition and progressed to osteopenia (after 3 years, 59.89%, p = 0.010) and osteoporosis (after 3 years, 74.37%, p = 0.035). In addition, the group diagnosed with osteopenia at baseline who progressed to osteoporosis after 3 years also showed a significant increase in gingival bleeding index (p < 0.001). CONCLUSIONS: The findings suggest that periodontal changes can be associated with osteoporosis in postmenopausal women.


Assuntos
Osteoporose Pós-Menopausa/complicações , Doenças Periodontais/complicações , Pós-Menopausa/fisiologia , Idoso , Densidade Óssea , Índice de Placa Dentária , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Pessoa de Meia-Idade , Índice Periodontal
4.
Community Dent Health ; 32(2): 77-82, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26263599

RESUMO

UNLABELLED: Pregnancy is a period in which several physical and emotional changes occur. These changes in pregnant women's mouths promote changes that need to be known by dentists, so that they can provide the necessary care to women. PURPOSE: To gather data from published studies on the knowledge of dentists about the oral health of pregnant women. METHODS: Papers published between 2003 and 2013 containing surveys on the topic under study were searched. Fourteen studies were selected and grouped into work areas. RESULTS: Dentists have doubts and fears about the care of pregnant women, to a greater or lesser degree, especially with regard to the use of X-rays, prescriptions and ideal gestational period of treatment. CONCLUSION: The results suggest a need to improve dentists' knowledge regarding dental care of pregnant women especially as during pregnancy women may acquire new habits relevant to the oral health of their children.


Assuntos
Odontólogos , Educação em Odontologia , Saúde Bucal , Gestantes , Atitude do Pessoal de Saúde , Assistência Odontológica , Odontólogos/psicologia , Feminino , Humanos , Padrões de Prática Odontológica , Gravidez , Cuidado Pré-Natal
5.
Artigo em Inglês | MEDLINE | ID: mdl-39038187

RESUMO

OBJECTIVES: This in vitro study focused on verifying the influence of different ambient light conditions on the accuracy and precision of models obtained from digital scans. METHODOLOGY: To measure the tested illuminances: chair light/reflector; room light, and natural light at the time of scanning, a luxmeter was used. From the STL file, nine experimental groups were formed. RESULTS: Of the nine specific combinations between the three IOS and the three types of lighting, it was verified that for all of them, as well as the ICC, the accuracy was also excellent, in which the measured values were not significantly influenced by the IOS brand (p = 0.994) nor by the type of lighting (p = 0.996). For precision data, GLM indicated a statistically significant interaction between IOS and lighting type. Under LS, accuracy was significantly higher with 3Shape® than with CS 3600 CareStream®, which had significantly higher accuracy than Virtuo Vivo™ Straumann®. CONCLUSIONS: The models obtained with the three IOS evaluated exhibited excellent accuracy under the different illuminance tested and the 3Shape® under the three illuminance conditions was the device that presented the best precision, specifically when using LC and LS.

6.
Appl Radiat Isot ; 170: 109559, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33476941

RESUMO

From a commercial supplier, three independent lots of an aqueous solution containing 223Ra in equilibrium with its deteriorating progeny were considered for standardization, by using live-time anticoincidence counting (LTAC) in the Laboratório Nacional de Metrologia das Radiações Ionizantes (LNMRI) Brazil. The ionization chamber calibration factors were obtained using measurements of independent lots of 223Ra in LTAC considering the absolute method in order to evaluate the constancy and reproducibility of the standardization. The calibration factors of three high-performance well-type ionization chamber systems and four commercial well-type ionization chambers were determined. The LTAC results showed that lots 2 and 3 were 1069.88 and 1097.44 kBq/kg, with corresponding relative standard uncertainties 0.12% and 0.20%, respectively. The spectrometry method results of each lot value were classified as positive by ANOVA hypothesis testing. The emission probabilities relating to the X- and γ-rays in region from 81 to 830 keV ware determined. Hence, LNMRI can provide calibration services for 223Ra.

7.
Appl Radiat Isot ; 166: 109323, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32795698

RESUMO

There are few long-lived radionuclides yielding high intensity gamma-rays emission with energies ranging from 100 keV to 500 keV that can be applied as radioactive gamma standard to calibrate HPGe detectors. Furthermore, this energy range represents the main emitted energies of the majority of radionuclides used in nuclear medicine. The Brazilian National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) has attempted to identify radionuclides that have the potential to be used as a calibration source due to their long half-life as well as their emission spectrum. Hence, LNMRI promotes standardization studies of gamma-emitting radionuclides that meet these criteria on order to disseminate them. Thorium-229, with its well-defined energies and relatively high intensities, is one such candidate radionuclide for the energy and full-energy peak efficiency calibration of high-purity gamma spectrometers. Thorium-229 was standardized by the method of 4παß(LS)-γ(NaI(Tl)) live timed anticoincidence counting. The emission intensities of gamma-rays associated with the decay of 229Th have been determined by HPGe gamma ray spectrometry with accuracy and precision. The results are in agreement with current literature data.

8.
Appl Radiat Isot ; 134: 64-67, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28942991

RESUMO

Traceability in Nuclear Medicine Service (NMS) measurements was checked by the Institute of Radioprotection and Dosimetry (IRD) through the Institute of Energy and Nuclear Research (IPEN). In 2016, IRD ran an intercomparison program and invited Brazilian NMS authorized to administer 131I to patients. Sources of 131I were distributed to 33 NMSs. Three other sources from the same solution were sent to IRD, after measurement at IPEN. These sources were calibrated in the IRD reference system. A correction factor of 1.013 was obtained. Ninety percent of the NMS comparisons results are within ±10% of the National Laboratory of Metrology of Ionizing Radiation (LNMRI) value, the Brazilian legal requirement.


Assuntos
Instituições de Assistência Ambulatorial , Radioisótopos do Iodo/análise , Serviço Hospitalar de Medicina Nuclear , Compostos Radiofarmacêuticos/análise , Brasil , Calibragem , Competência Profissional , Controle de Qualidade , Reprodutibilidade dos Testes , Fatores de Tempo , Incerteza
9.
Braz J Med Biol Res ; 39(11): 1435-44, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17146556

RESUMO

Evidence based on immunological cross-reactivity and anti-diabetic properties has suggested the presence of insulin-like peptides in plants. The objective of the present study was to investigate the presence of insulin-like proteins in the leaves of Bauhinia variegata ("pata-de-vaca", "mororó"), a plant widely utilized in popular medicine as an anti-diabetic agent. We show that an insulin-like protein was present in the leaves of this plant. A chloroplast protein with a molecular mass similar to that of bovine insulin was extracted from 2-mm thick 15% SDS-PAGE gels and fractionated with a 2 x 24 cm Sephadex G-50 column. The activity of this insulin-like protein (0.48 mg/mL) on serum glucose levels of four-week-old Swiss albino (CF1) diabetic mice was similar to that of commercial swine insulin used as control. Further characterization of this molecule by reverse-phase hydrophobic HPLC chromatographic analysis as well as its antidiabetic activity on alloxan-induced mice showed that it has insulin-like properties. Immunolocalization of the insulin-like protein in the leaves of B. variegata was performed by transmission electron microscopy using a polyclonal anti-insulin human antibody. Localization in the leaf blades revealed that the insulin-like protein is present mainly in chloroplasts where it is also found associated with crystals which may be calcium oxalate. The presence of an insulin-like protein in chloroplasts may indicate its involvement in carbohydrate metabolism. This finding has strengthened our previous results and suggests that insulin-signaling pathways have been conserved through evolution.


Assuntos
Bauhinia/química , Cloroplastos/química , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/isolamento & purificação , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/isolamento & purificação , Folhas de Planta/química , Animais , Autoanticorpos/sangue , Bauhinia/citologia , Bovinos , Cloroplastos/ultraestrutura , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Hipoglicemiantes/uso terapêutico , Imunoglobulina G/sangue , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/uso terapêutico , Camundongos , Microscopia Eletrônica de Transmissão , Folhas de Planta/citologia
10.
Appl Radiat Isot ; 109: 389-392, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26805708

RESUMO

(123)I is widely used for radiodiagnostic procedures. It is produced by reaction of (124)Xe (p,2n) (123)Cs →(123)Xe →(123)I in cyclotrons. (121)Te and (125)I appear in a photon energy spectrum as impurities. An activity of (121)Te was calibrated absolutely by sum-peak method and its photon emitting probability was estimated, whose results were consistent with published results.

11.
Appl Radiat Isot ; 109: 236-241, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26688362

RESUMO

Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.


Assuntos
Radioisótopos de Flúor/análise , Radioisótopos de Flúor/normas , Setor Público/normas , Radiometria/métodos , Radiometria/normas , Brasil , Padrões de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
12.
Braz J Med Biol Res ; 36(9): 1167-73, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12937781

RESUMO

Since the discovery of bovine insulin in plants, much effort has been devoted to the characterization of these proteins and elucidation of their functions. We report here the isolation of a protein with similar molecular mass and same amino acid sequence to bovine insulin from developing fruits of cowpea (Vigna unguiculata) genotype Epace 10. Insulin was measured by ELISA using an anti-human insulin antibody and was detected both in empty pods and seed coats but not in the embryo. The highest concentrations (about 0.5 ng/micro g of protein) of the protein were detected in seed coats at 16 and 18 days after pollination, and the values were 1.6 to 4.0 times higher than those found for isolated pods tested on any day. N-terminal amino acid sequencing of insulin was performed on the protein purified by C4-HPLC. The significance of the presence of insulin in these plant tissues is not fully understood but we speculate that it may be involved in the transport of carbohydrate to the fruit.


Assuntos
Fabaceae/química , Insulina/análise , Proteínas de Plantas/análise , Homologia de Sequência de Aminoácidos , Animais , Western Blotting , Bovinos , Cromatografia Líquida de Alta Pressão , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Fabaceae/genética , Insulina/genética , Peso Molecular , Proteínas de Plantas/genética
13.
Braz J Med Biol Res ; 33(2): 191-8, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10657058

RESUMO

The presence of phaseolin (a vicilin-like 7S storage globulin) peptides in the seed coat of the legume Phaseolus lunatus L. (lima bean) was demonstrated by N-terminal amino acid sequencing. Utilizing an artificial seed system assay we showed that phaseolin, isolated from both cotyledon and testa tissues of P. lunatus, is detrimental to the nonhost bruchid Callosobruchus maculatus (F) (cowpea weevil) with ED50 of 1.7 and 3.5%, respectively. The level of phaseolin in the seed coat (16.7%) was found to be sufficient to deter larval development of this bruchid. The expression of a C. maculatus-detrimental protein in the testa of nonhost seeds suggests that the protein may have played a significant role in the evolutionary adaptation of bruchids to legume seeds.


Assuntos
Besouros/fisiologia , Fabaceae/química , Proteínas de Plantas/isolamento & purificação , Plantas Medicinais , Sementes/química , Sequência de Aminoácidos , Animais , Besouros/efeitos dos fármacos , Fabaceae/parasitologia , Dados de Sequência Molecular , Proteínas de Plantas/genética , Proteínas de Plantas/farmacologia
14.
Braz J Med Biol Res ; 35(3): 297-303, 2002 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11887207

RESUMO

We report the detection of insulin-like antigens in a large range of species utilizing a modified ELISA plate assay and Western blotting. We tested the leaves or aerial parts of species of Rhodophyta (red alga), Bryophyta (mosses), Psilophyta (whisk ferns), Lycopodophyta (club mosses), Sphenopsida (horsetails), gymnosperms, and angiosperms, including monocots and dicots. We also studied species of fungi and a cyanobacterium, Spirulina maxima. The wide distribution of insulin-like antigens, which in some cases present the same electrophoretic mobility as bovine insulin, together with results recently published by us on the amino acid sequence of an insulin isolated from the seed coat of jack bean (Canavalia ensiformis) and from the developing fruits of cowpea (Vigna unguiculata), suggests that pathways depending on this hormone have been conserved through evolution.


Assuntos
Fungos/química , Insulina/análise , Proteínas de Plantas/análise , Proteínas/análise , Rodófitas/química , Animais , Proteínas de Bactérias/análise , Proteínas de Bactérias/genética , Western Blotting , Bovinos , Cianobactérias/química , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Fungos/genética , Peso Molecular , Proteínas de Plantas/genética , Rodófitas/genética
15.
J Econ Entomol ; 90(2): 340-8, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9145031

RESUMO

Canatoxin is a toxic protein isolated from the jackbean, Canavalia ensiformis. The toxin injected intraperitoneally is lethal for mice and rats; however, it is inactive if given orally. In this study, Manduca sexta (L.) (Lepidoptera), Schistocerca americana (Drury) (Orthoptera), Drosophila melanogaster (L.) (Diptera), Aedes aegypti (L.) (Diptera), Rhodnius prolixus (Stål) (Hemiptera), and Callosobruchus maculatus (F.) (Coleoptera) were fed on canatoxin-containing diets. No effects were seen in M. sexta, S. americana, D. melanogaster, or A. aegypti. No traces of canatoxin were found in their feces, suggesting that the protein was digested completely by these insects, which characteristically have a trypsin-based digestion. In contrast, canatoxin was lethal for insects displaying cathepsin-based digestion. Thus, for C. maculatus, a diet containing 0.25% wt:wt canatoxin caused complete inhibition of larval growth. When R. prolixus were fed on canatoxin, 2 effects were seen: impairment of water excretion and increased lethality 48-96 h after feeding. The lethal effect of canatoxin in R. prolixus was blocked partially or completely when the digestion of the toxin by R. prolixus midgut enzymes was impaired. The data showed that canatoxin is highly toxic when ingested by some species of insects but not affecting others, probably in correlation with the characteristics of the digestive process of the insect.


Assuntos
Controle de Insetos , Insetos , Inseticidas , Lectinas , Proteínas de Plantas , Plantas , Toxinas Biológicas , Aedes , Animais , Biotransformação , Catepsinas/metabolismo , Besouros , Drosophila melanogaster , Endopeptidases/metabolismo , Manduca , Ortópteros , Rhodnius
16.
Fitoterapia ; 72(1): 73-5, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11163947

RESUMO

The antibacterial effects of extracts obtained from Persea cordata stem bark, employed in Brazil to treat infectious diseases, were studied. The ethyl acetate fraction of the hydroalcoholic extract showed activity against pathogenic bacteria which may justify the popular use of the plant.


Assuntos
Bactérias/efeitos dos fármacos , Lauraceae , Plantas Medicinais , Humanos , Testes de Sensibilidade Microbiana , Extratos Vegetais/farmacologia , Caules de Planta/química
17.
J Forensic Odontostomatol ; 20(2): 25-30, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12585670

RESUMO

The aim of this study was to evaluate the ability of trained observers to identify altered radiographic images after modifications using an image-editing software. Based on implantology in 10 radiographs, eight panoramic and one linear tomograph were modified while one tomograph was untouched. Implants were placed or removed and bone levels were altered, and seventy dentists were invited to identify these alterations. The results showed that the percentage of the correct answers was 12.5% or 2 identifications per examiner. The rate of false positives in relation to correct answers was at a level of 6:1. We concluded that the professionals have difficulty in identifying altered radiographs after using an image-editing software and that the seriousness of this situation demands that dentists be warned of the dangers of the use and abuse of this technology.


Assuntos
Enganação , Implantes Dentários , Fraude/prevenção & controle , Radiografia Dentária Digital , Brasil , Odontologia Legal/legislação & jurisprudência , Humanos , Processamento de Imagem Assistida por Computador/legislação & jurisprudência , Mandíbula/diagnóstico por imagem , Maxila/diagnóstico por imagem , Variações Dependentes do Observador , Radiografia Panorâmica/normas
18.
Spectrochim Acta A Mol Biomol Spectrosc ; 56A(7): 1329-35, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10888438

RESUMO

Atomic polar tensors of carbon tetrafluoride are calculated from experimental fundamental infrared intensities measured by several research groups. Quantum chemical calculations using a 6-311 + + G(3d, 3p) basis set at the Hartree-Fock, Möller-Plesset 2 and Density Functional Theory (B3LYP) levels are used to resolve the sign ambiguities of the dipole moment derivatives. The resulting carbon mean dipole moment derivative, pC = 2.051 e, is in excellent agreement with values estimated by a MP2/6-311 + + G(3d, 3p) theoretical calculation, 2.040 e, and by an empirical electronegativity model, 2.016 e. The pC value determined here is also in excellent agreement with the one obtained from the CF4 1s carbon ionization energy using a simple potential model, 2.059 e. Crawford's G intensity sum rule applied to the fundamental intensities of CH4, CH3F, CH2F2 and CHF3 results in a prediction of a 1249 km mol(-1) intensity sum for CF4 in good agreement with the experimental values of 1328 +/- 37.9, 1208.0 +/- 54.4 and 1194.8 +/- 7.4 km mol(-1) reported in the literature.


Assuntos
Carbono/química , Espectroscopia de Luz Próxima ao Infravermelho
19.
Artigo em Inglês | MEDLINE | ID: mdl-11206559

RESUMO

The polar tensors of CF3Cl, CF2Cl2 and CFCl3 have been calculated using recent measurements of their gas phase infrared fundamental intensities. The polar tensors obtained for CF2Cl2 and CFCl3 are in very good agreement with those obtained previously since the more recent experimental intensity results are in good agreement with those reported earlier. For CF2Cl2 rhoC = +1.626, rhoF = -0.577 and rhoCl = -0.26e whereas rhoC = +1.369, 0.478 and rhoCl = 0.297e for CFCl3. However, two sets of significantly different mean dipole moment derivatives are obtained from the experimentally measured intensities of CF3Cl reported by two different laboratories. On the other hand, the differences in the mean derivatives of these two sets are not large enough so that results from electronegativity models, potential models for core ionization energies and quantum chemical calculations at the Moller-Plesset 2 and B3LYP density functional levels are sufficient to indicate which set is the correct one. As such average values of rhoC = +1.907+/-0.178e, rhoF = -0.590+/-0.056e and rhoCl = -0.139+/-0.013e obtained from both sets of polar tensor elements are recommended for the CF33Cl mean dipole moment derivatives.


Assuntos
Clorofluorcarbonetos de Metano/química , Eletroquímica , Software
20.
Z Naturforsch C J Biosci ; 55(9-10): 820-3, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11098837

RESUMO

This paper describes the isolation, identification and analgesic activity of a new biflavonoid from Rheedia gardneriana leaves, which correspond to I3-naringenin-II8-4'-OMe-eriodictyol (GB-2a-II-4'-OMe) (1), with a methoxyl group in position 4 of ring-II. Its structure was determined by spectroscopic data and confirmed by an alkaline hydrolysis. Its analgesic effect was evaluated in a writhing test and a formalin test in mice. It was found that this compound exhibits potent and dose-related analgesic action in both experimental models, with ID50's values of 4.5 micromol/kg against the writhing test and 8.2 and 6.8 micromol/kg against the first and second phase of the formalin test, respectively. It was several times more potent than some well-known analgesic drugs used as reference.


Assuntos
Analgésicos/química , Biflavonoides , Flavonoides/química , Dor/tratamento farmacológico , Plantas Medicinais/química , Acetaminofen/farmacologia , Ácido Acético , Analgésicos/isolamento & purificação , Analgésicos/farmacologia , Animais , Aspirina/farmacologia , Dipirona/farmacologia , Flavanonas , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Formaldeído , Indometacina/farmacologia , Masculino , Camundongos , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Dor/induzido quimicamente , Dor/fisiopatologia , Folhas de Planta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA