57 resultados para QSAR-2D


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Objective To evaluate the association of conventional angiography (AG) with computed tomography angiography (CTA) as compared with CTA only, preoperatively, in the treatment of aortic diseases. Materials and Methods Retrospective study involving patients submitted to endovascular treatment of aortic diseases, in the period from January 2009 to July 2010, with use of preoperative CTA + conventional AG or CTA only. The patients were divided into two groups, namely: G1 – thoracic aortic diseases; and G2 – abdominal aortic diseases. G1 was subdivided into 1A (preoperative AG + CTA) and 1B (preoperative CTA). G2 was subdivided into 2C (CTA + AG) and 2D (CTA only). Results The authors evaluated 156 patients. In subgroups 1A and 1B, the rate of technical success was, respectively, 100% and 94.7% (p = 1.0); and the rate of therapeutic success was, respectively, 81% and 58% (p = 0.13). A higher number of complications were observed in subgroup 1B (p = 0.057). The accuracy in the calculation of the prosthesis was higher in subgroup 1A (p = 0.065). In their turn, the rate of technical success in subgroups 2C and 2D was, respectively, 92.3% and 98.6% (p = 0.17). The rate of therapeutic success was 73% and 98.6% (p = 0.79). Conclusion Preoperative conventional AG should be reserved for cases where CTA cannot provide all the information in the planning of a therapeutic intervention.

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Objetivo:Determinar intervalos de referência para o volume da cisterna magna fetal por meio do método bidimensional (2D) usando o modo multiplanar da ultrassonografia tridimensional.Materiais e Métodos:Estudo de corte transversal com 224 gestantes normais entre a 17ª e 29ª semanas. O volume foi obtido automaticamente pela multiplicação dos três maiores eixos nos planos axial e sagital pela constante 0,52. Regressão polinomial foi realizada para obter correlação entre o volume 2D da cisterna magna e a idade gestacional, sendo os ajustes realizados pelo coeficiente de determinação (R2). Confiabilidade e concordância foram obtidas pelo coeficiente de correlação intraclasse (CCI) e limites de concordância.Resultados:A média do volume da cisterna magna 2D variou de 0,71 ± 0,19 cm3 para 4,18 ± 0,75 cm3 entre a 17ª e 29ª semanas, respectivamente. Observou-se boa correlação do volume da cisterna magna fetal 2D e a idade gestacional (R2 = 0,67). Observou-se excelente confiabilidade e concordância intraobservador com CCI = 0,89 e limites de concordância 95% (-52,0; 51,8), respectivamente. Observou-se baixa confiabilidade e concordância interobservador com CCI = 0,64 e limites de concordância 95% (-110,1; 84,6), respectivamente.Conclusão:Intervalos de referência para o volume 2D da cisterna magna fetal usando o modo multiplanar da ultrassonografia tridimensional foram determinados e apresentaram excelente confiabilidade e concordância intraobservador.

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Objetivo: Avaliar um protocolo de espectroscopia por ressonância magnética (ERM) do próton de hidrogênio (1H) bidimensional (2D) disponível comercialmente (Siemens Medical Systems; Erlangen, Alemanha), aplicado para nódulos adrenais e diferenciação das massas (adenomas, feocromocitomas, carcinomas e metástases). Materiais e Métodos: Um total de 118 pacientes (36 homens e 82 mulheres), apresentando-se com 138 nódulos/massas adrenais, foi avaliado prospectivamente (média de idade: 57,3 ± 13,3 anos). Uma sequência de ERM-1H-PRESS-CSI (espectroscopia por resolução de ponto-imagem por desvio químico) multivoxel foi utilizada. Análise espectroscópica foi realizada da esquerda-direita, sentido crânio-caudal, usando três sequências sagitais, além de sequências axiais e coronais T2-HASTE. Os seguintes índices foram calculados: colina (Cho)/creatina (Cr), 4,0–4,3 ppm/Cr, lipídio (Lip)/Cr, Cho/Lip e lactato (Lac)/Cr. Resultados: ERM-1H-2D foi bem sucedida em 123 (89,13%) lesões. Os valores de sensibilidade e especificidade encontrados para as proporções e pontos de corte avaliados foram: Cho/Cr ≥ 1,2, sensibilidade de 100% e especificidade de 98,2% (diferenciação de adenomas e carcinomas de feocromocitomas e metástases); 4,0–4,3 ppm/Cr ≥ 1,5, 92,3% de sensibilidade, especificidade de 96,9% (diferenciação de carcinomas e feocromocitomas de adenomas e metástases); Lac/Cr ≤ –7,449, sensibilidade de 90,9% e especificidade de 77,8% (diferenciação de feocromocitomas contra carcinomas e adenomas). Conclusão: Os dados da ERM-1H-2D foram eficazes e permitiram a diferenciação entre massas adrenais e nódulos na maioria das lesões com diâmetro > 1,0 cm.

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There are NMR data of ¹H and 13C of the iridoid plumieride, but controversy related to the assignments of the protons H-3 or H-10 and carbons C-6 or C-7 and C-3 or C-10 are described in the literature. There are a little discussion regarding to the resonance assignment of protons of the glycoside unity. Analysis based on 2D shift correlated NMR spectra (COSY, HETCOR, HETCORLR) and NOE difference ¹H NMR spectra allowed to assign unambigously the chemical shift of ¹H and 13C of plumieride which has been found in the literature with non coincident values.

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A computational interface, using sybyl format as an input file, was created in order to calculate connectivity indexes. After generation and classification of all substructures, which derive from the molecular structure, this interface calculates all possible orders from zero up to the maximun number of bonds in the molecule. Other topological indexes such as Wiener and Schultz indexes can also be calculated.

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The flowers of Stiffitia chrysantha Mikam(Asteraceae) contain eriodictiol, quercetin, luteolin and b-D-glycopyranosil-sitosterol. These compounds and its derivatives were identified by their 1H and 13C NMR, infra-red and mass spectra data. The heteronuclear 2D NMR were used to confirm the assignments of the proton and carbon chemical shifts, it was used to eliminate definitively the ambiguous correlation reported in the literature for C-5 and C-9 of quercetin and C-23 and C-25 of b-D-glycopyranosil-sitosterol.

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This paper describes the chemical constituents isolated from roots of Pyrostegia venusta. From ethanol extract of the roots allantoin, beta-sitosterol, 3b-O-beta-D-glupyranosylsitosterol and hesperedin were isolated. The structures of these natural products were identified on the basis of spectral data, including 2D NMR of the peracetyl derivative of hesperidin.

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Combinatorial chemistry has emerged as a tool to circumvent a major problem of pharmaceutical industries to discover new lead compounds. A rapid and massive evaluation of a myriad of newly synthesised compounds can be carried out. Combinatorial synthesis leads to high throughput screening en masse towards another myriad of biological targets. The design of a set of compounds based upon combinatorial chemistry may be envisaged by using of QSPR-SIMCA and QSAR-SIMCA as tools for classification purposes. This work deals with the definition and establishment of a spanned substituent space (SSS) that reduces the analogue numbers with no exclusion of global content. The chemical diversity may be set properly within a specified pharmacological field. This allows a better use of its potentiality without loosing information.

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The structures of seven oleanene and ursene triterpenoids (1-7) isolated from aerial parts of Mentha villosa were identified. In addition, the complete ¹H and 13C resonance assignments of these triterpenoids were accomplished using 1D and 2D NMR spectroscopic experiments.

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The present paper aims to bring under discussion some theoretical and practical aspects about the proposition, validation and analysis of QSAR models based on multiple linear regression. A comprehensive approach for the derivation of extrathermodynamic equations is reviewed. Some examples of QSAR models published in the literature are analyzed and criticized.

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Chromatographic fractionation of bark extracts from Simira glaziovii (Rubiaceae) afforded the steroids beta-sitostenone, stigmastenone, beta-sitosterol and stigmasterol, methyl trans-4-hidroxy-3-methoxycinamate (1), the alkaloids harmane (2) and the new stereoisomer of ophiorine B (3). The structures were established by ¹H and 13C NMR, including 2D techniques and mass spectral analysis, of the natural products and pentaacetyllyalosidic acid (4a) and beta-carboline monoterpene tetraacetylglucoside (5, 1,22-lactamlyaloside) derivatives obtained by chemical transformations.

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Phytochemical investigation of the resin, fruits, leaves, and trunk of Protium heptaphyllum led to the isolation of the monoterpene p-menth-3-ene-1,2,8-triol, alpha and beta amyrin, quercetin, brein, quercetin-3-O-rhamnosyl, (-) catechin and scopoletin. Their structures were established by 1D and 2D NMR spectroscopy and comparison with published data.