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1.
Artículo en Inglés | MEDLINE | ID: mdl-36360854

RESUMEN

Breast cancer (BC) is the leading cause of cancer in women, and has implications for sexual function (SF). In this study, we used an evidence map to identify, describe, and organise the current available evidence regarding SF in women with BC. We searched the MEDLINE, PsycINFO, and CINAHL databases for observational studies assessing SF in women with BC published in English, Spanish, Portuguese, and French between 2000 and 2021 (sample ≥ 50 women). Of the 64 included studies (13,257 women with BC), 58 were published since 2010. Women who were married, partnered, or in relationships represented 74.1% of the entire sample. Only a single study was conducted on women representing a sexual minority. We identified 22 assessment instruments and 40 sexual dysfunction (SdF) domains. The number of publications on SF in women with BC has increased in the last 10 years, but still remains low. Some groups of women are underrepresented, and some SdF domains are underdiagnosed, with the assessment instrument used affecting which domains are studied. Women with BC need to be better screened, as their quality of life (QoL) is affected by SdF.


Asunto(s)
Neoplasias de la Mama , Disfunciones Sexuales Fisiológicas , Femenino , Humanos , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/complicaciones , Calidad de Vida , Disfunciones Sexuales Fisiológicas/etiología , Parejas Sexuales , Estudios Observacionales como Asunto
2.
Spectrochim Acta A Mol Biomol Spectrosc ; 280: 121544, 2022 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-35753098

RESUMEN

n-Alkanes and long-chain alcohols (LCOH) have been used as faecal markers to assess the feeding behaviour of both wild and domestic herbivore species. However, their chemical analysis is time-consuming and expensive, making it necessary to develop more expeditious methodologies to evaluate concentrations of these markers. This work aimed to evaluate the use of Fourier Transform Infrared Spectroscopy (FTIR) technology in the near infrared (NIR) and mid infrared (MIR) intervals, for the determination of n-alkane and LCOH concentrations of different plant species and faecal samples of domestic herbivores. Spectra of 33 feed samples, namely L. perenne, T. repens, U. gallii, short heathers (mixture of Erica spp. and Calluna vulgaris), improved pasture grasses (mixture of L. perenne and A. capillaris), heath grasses (mixture of P. longifolium and A. curtissii), improved pasture species (mixture of L. perenne, T. repens and A. capillaris) and herbaceous species (mixture of all herbaceous species found in the plot)) and 181 faecal samples (cattle and horses) were recorded. In order to develop calibrations for the prediction of n-alkanes and LCOH concentrations, partial least squares (PLS) regression was used. Regarding the models developed for plant species, the best results were observed for the calibrations using NIR. The best external validation coefficients of determination (R2v) obtained were 0.90 and 0.79 for LCOH and n-alkanes, respectively. For faecal samples, in the NIR interval, results indicate similar external validation predictions (R2v) for both animal species (0.64). On the contrary, in the MIR interval, differences between cattle (0.70) and horses (0.57) faecal samples in R2v were observed. Regarding the models created for both animal species faeces, LCOH (C26-OH and C30-OH concentrations ranging from 713.3 to 4451.9 mg/kg DM, respectively; R2v values ranging from 0.72 to 0.95) and n-alkanes (C31 and C33 concentrations ranging from 112.8 to 643.2 mg/kg DM, respectively; R2v values ranging from 0.19 to 0.90) present in higher concentrations tended to be those with better estimates. Results obtained suggest that the selection of the technique to be used may depend on the type of matrix, being the homogeneity of the matrices one of the most important factors for its success. In order to improve the accuracy and robustness of the models created for the estimation of the concentrations of these markers using these methodologies, the database (greater variability) used for the calibrations of these models must be increased.


Asunto(s)
Alcanos , Conducta Alimentaria , Alcanos/análisis , Animales , Biomarcadores/análisis , Bovinos , Heces/química , Caballos , Plantas , Espectroscopía Infrarroja por Transformada de Fourier
3.
J Sci Food Agric ; 102(2): 782-793, 2022 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-34227127

RESUMEN

BACKGROUND: The application of kaolin particle film is considered a short-term strategy against several environmental stresses in areas with a Mediterranean-like climate. However, it is known that temperature fluctuations and water availability over the season can jeopardize kaolin efficiency in many Mediterranean crops. Hence, this study aims to evaluate the effects of kaolin foliar application on berry phytohormones, antioxidant defence, and oenological parameters at veraison and harvest stages of Touriga-Franca (TF) and Touriga-Nacional (TN) grapevines in two growing seasons (2017 and 2018). The 2017 growing season was considered the driest (-147.1 dryness index) and the warmest (2705 °C growing degree days) of the study. RESULTS: In 2017, TF kaolin-treated berries showed lower salicylic acid (-26.6% compared with unsprayed vines) and abscisic acid (ABA) (-10.5%) accumulation at veraison, whereas salicylic acid increased up to 28.8% at harvest. In a less hot season, TN and TF kaolin-treated grapevines showed a twofold in ABA content and a threefold increase in the indole-3-acetic acid content at veraison and lower ABA levels (83.8%) compared with unsprayed vines at harvest. Treated berries showed a decreased sugar content, without compromising malic and tartaric acid levels, and reactive oxygen species accumulation throughout berry ripening. CONCLUSION: The results suggest kaolin exerts a delaying effect in triggering ripening-related processes under severe summer stress conditions. Treated berries responded with improved antioxidant defence and phytohormone balance, showing significant interactions between kaolin treatment, variety, and developmental stage in both assessed years. © 2021 Society of Chemical Industry.


Asunto(s)
Frutas/química , Reguladores del Crecimiento de las Plantas/metabolismo , Vitis/efectos de los fármacos , Vitis/crecimiento & desarrollo , Ácido Abscísico/análisis , Ácido Abscísico/metabolismo , Clima , Frutas/efectos de los fármacos , Frutas/crecimiento & desarrollo , Frutas/metabolismo , Ácidos Indolacéticos/análisis , Ácidos Indolacéticos/metabolismo , Caolín/farmacología , Reguladores del Crecimiento de las Plantas/análisis , Ácido Salicílico/análisis , Ácido Salicílico/metabolismo , Vitis/química , Vitis/metabolismo
4.
Plant Physiol Biochem ; 162: 647-655, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33774469

RESUMEN

Field-grown grapevines are often exposed to multiple environmental stresses, which challenges wine-growers to develop sustainable measures to sustain vine growth, yield, and quality. Under field conditions this task is demanding, due to differences in the magnitudes of stresses and associated plant responses. In this study we explored the hypothesis that kaolin-particle film application improves grapevine photoprotection through the regulation of xanthophyll cycle genes, limiting the thermal dissipation of excess energy under harsh environmental conditions. Hence, we selected two grapevine varieties, Touriga-Nacional (TN) and Touriga-Franca (TF), grown in the Douro Demarcated Region, and evaluated changes in light dissipation mechanisms, xanthophyll cycle components, and the expression of xanthophyll cycle genes during the 2017 summer season. The results showed that, from veraison to ripening, kaolin triggered the up-regulation of violaxanthin de-epoxidase (VvVDE1) and zeaxanthin epoxidase (VvZEP1) genes, indicating optimised regulation of the xanthophyll cycle. Kaolin treatment also decreased chlorophyll (Chla, Chlb, Chl(a+b)) and carotenoid (Car) accumulation under increasing summer stress conditions in both varieties and lowered the non-photochemical quenching (NPQ) of grapevines on ripening, suggesting a long-term response to summer stress. In addition, kaolin-treated grapevines showed increased Chla/Chlb and lower Chl(a+b)/Car ratios, displaying some features of high light adapted leaves. Overall, this study suggests that kaolin application enabled grapevines to benefit from fluctuating periods of summer stress by managing chlorophyll and carotenoid content and limiting down-regulation of both photochemistry and photoinhibition processes. Under Mediterranean field conditions, kaolin application can be considered an efficient method of minimising summer stress impact on grapevines.


Asunto(s)
Clorofila , Xantófilas , Carotenoides , Luz , Hojas de la Planta , Tecnología
5.
Food Chem ; 325: 126938, 2020 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-32387957

RESUMEN

The present study evaluated the ability of Attenuated Total Reflectance - Mid-Infrared (ATR-MIR) spectroscopy combined with Partial Least Squares Discriminant Analysis (PLS-DA) to discriminate the origin and harvest year of 'Tempranillo' grape clones and with Partial Least Squares (PLS) regressions to predict its contents in soluble solids (SS), pH and titratable acidity (TA). Normalized spectra of grape homogenates and normalized plus 1st Derivative spectra of grape skins allowed an overall percentage of correct classifications of 99.6% and 96.7% in validation, according to origin, and 98.3% and 90.0% in validation, according to harvest year, respectively. The normalized spectra of grape homogenates allowed a calibration and validation determination coefficients (R2) of 0.92 and 0.90 for SS, 0.90 and 0.84 for pH, 0.88 and 0.84 for TA, respectively. The ATR-MIR combined with multivariate analysis showed to be an appropriate tool to assist the clonal selection process of 'Tempranillo'.

6.
Antioxidants (Basel) ; 9(2)2020 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-32102193

RESUMEN

Phaseolus vulgaris L. is the most commonly consumed legume in the world, given its high vegetable protein content, phenolic compounds, and antioxidant properties. It also represents one of the most sustainable, low-carbon and sources of food available at present to man. This study aims to identify the nutrients, antinutrients, phenolic composition, and antioxidant profile of 10 common bean cultivars (Arikara yellow, butter, cranberry, red kidney, navy, pinto, black, brown eyed, pink eyed, and tarrestre) from two harvest years, thereby assessing the potential of each cultivar for specific applications in the food industry. Navy and pink eyed beans showed higher potential for enrichment of foodstuffs and gluten-free products due to their higher protein and amino acid contents. Additionally, red kidney, cranberry and Arikara yellow beans had the highest content of phenolic compounds and antioxidant properties, which can act as functional ingredients in food products, thus bringing health benefits. Our study highlights the potential of using specific bean cultivars in the development of nutrient-enriched food and as functional ingredients in diets designed for disease prevention and treatment.

7.
Food Chem ; 306: 125509, 2020 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-31627082

RESUMEN

Common beans (Phaseolus vulgaris L.), represent the most consumed legume worldwide and constitute an important source of protein, being also known to contain antinutritional compounds, which compromise nutrients' bioavailability. However, the standard methodologies to assess these constituents are time-consuming and complex. Therefore, the present study evaluated the suitability of near-infrared (NIR) and mid-infrared (MIR) spectroscopies for the development of simple and reliable methods to assess protein, lipids, tannins and phytic acid contents, besides specific amino acids, in whole bean flours. Partial least squares (PLS) regression was used to develop analytical models, and external validation was performed. NIR displayed better performance for the evaluation of protein, lipids, tannins and phytic acid contents, and MIR, for the assessment of specific amino acids. In both techniques, the use of the 1st derivative was the best data treatment. Overall, both techniques represent reliable methods to evaluate the proximate and antinutritional composition of bean flours.


Asunto(s)
Phaseolus/química , Análisis de los Mínimos Cuadrados , Ácido Fítico/análisis , Espectroscopía Infrarroja Corta/métodos , Análisis Espectral , Taninos/análisis
8.
Nanomaterials (Basel) ; 9(7)2019 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-31323800

RESUMEN

The interaction between gold sub-nanometer clusters composed of ten atoms (Au10) and tetrakis(4-sulfonatophenyl)porphyrin (TPPS) was investigated through various spectroscopic techniques. Under mild acidic conditions, the formation, in aqueous solutions, of nanohybrid assemblies of porphyrin J-aggregates and Au10 cluster nanoparticles was observed. This supramolecular system tends to spontaneously cover glass substrates with a co-deposit of gold nanoclusters and porphyrin nanoaggregates, which exhibit circular dichroism (CD) spectra reflecting the enantiomorphism of histidine used as capping and reducing agent. The morphology of nanohybrid assemblies onto a glass surface was revealed by atomic force microscopy (AFM), and showed the concomitant presence of gold nanoparticles with an average size of 130 nm and porphyrin J-aggregates with lengths spanning from 100 to 1000 nm. Surface-enhanced Raman scattering (SERS) was observed for the nanohybrid assemblies.

9.
Molecules ; 22(11)2017 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-29144445

RESUMEN

Olive oil displays remarkable organoleptic and nutritional features, which turn it into a foodstuff appreciated by consumers, and a basic component of the Mediterranean diet. Indeed, the noticed benefits of including olive oil in the diet have been assigned to the presence of diverse bioactive compounds with different molecular structures. These compounds confer a wide range of biological properties to this food matrix, including the prevention of distinct human diseases as well as the modulation of their severity. The most relevant bioactive compounds present in olive oil correspond to benzoic and cinnamic acids, phenolic alcohols and secoiridoids, and also flavonoids. Over the last decades, several studies, devoted to gaining a further insight into the relative contribution of the separate groups and individual compounds for their biological activities, have been conducted, providing relevant information on structure-activity relationships. Therefore, this paper critically reviews the health benefits evidenced by distinct phenolic compounds found in olive oils, thus contributing to clarify the relationship between their chemical structures and biological functions, further supporting their interest as essential ingredients of wholesome foods.


Asunto(s)
Olea/química , Olea/metabolismo , Aceite de Oliva/química , Fitoquímicos/química , Fitoquímicos/metabolismo , Animales , Antioxidantes/química , Flavonoides/química , Humanos , Iridoides/química , Fenoles/química
10.
J Sci Food Agric ; 97(13): 4295-4305, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28276078

RESUMEN

BACKGROUND: Freezing represents a common conservation practice regarding vegetal foodstuffs. Since compositional features need to be monitored during storage, the development of rapid monitoring tools suitable for assessing nutritional characteristics arises as a pertinent issue. In this study, cowpea (Vigna unguiculata L.) pods, both fresh and after 6 and 9 months of freezing at -18 °C, were evaluated by high-performance liquid chromatography for their content of protein as well as of essential and nonessential amino acids, while their Fourier transform infrared spectra in the mid infrared (MIR) and near infrared (NIR) ranges were concomitantly registered to assess the feasibility of this approach for the traceability of these frozen matrices. RESULTS: For the NIR interval, the application of the 1st derivative to the spectral data retrieved the best results, while for lower concentrations the application of the Savitzky-Golay algorithm was indispensable to achieve quantification models for the amino acids. MIR is also suitable for this purpose, though being unable to quantify amino acids with concentrations below 0.07 mmol g-1 dry weight, irrespective of the data treatment used. CONCLUSIONS: The spectroscopic approach constitutes a methodology suitable for monitoring the impact of freezing on the nutritional properties of cowpea pods, allowing accurate quantification of the protein and amino acid contents, while NIR displayed better performance. © 2017 Society of Chemical Industry.


Asunto(s)
Conservación de Alimentos/métodos , Semillas/química , Vigna/química , Aminoácidos/análisis , Cromatografía Líquida de Alta Presión , Almacenamiento de Alimentos , Congelación , Fitoquímicos/análisis , Proteínas de Plantas/análisis , Semillas/crecimiento & desarrollo , Espectroscopía Infrarroja por Transformada de Fourier , Vigna/crecimiento & desarrollo
11.
Molecules ; 22(2)2017 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-28216592

RESUMEN

Grape and wine phenolics display a noticeable structural diversity, encompassing distinct compounds ranging from simple molecules to oligomers, as well as polymers usually designated as tannins. Since these compounds contribute critically to the organoleptic properties of wines, their analysis and quantification are of primordial importance for winery industry operators. Besides, the occurrence of these compounds has been also extensively described in winery residues, which have been pointed as a valuable source of bioactive phytochemicals presenting potential for the development of new added value products that could fit the current market demands. Therefore, the cumulative knowledge generated during the last decades has allowed the identification of the most promising compounds displaying interesting biological functions, as well as the chemical features responsible for the observed bioactivities. In this regard, the present review explores the scope of the existing knowledge, concerning the compounds found in these winery by-products, as well as the chemical features presumably responsible for the biological functions already identified. Moreover, the present work will hopefully pave the way for further actions to develop new powerful applications to these materials, thus, contributing to more sustainable valorization procedures and the development of newly obtained compounds with enhanced biological properties.


Asunto(s)
Fenoles/química , Extractos Vegetales/química , Vitis/química , Vino/análisis , Antocianinas/química , Antioxidantes/química , Flavonoles/química , Frutas/química , Hidroxibenzoatos/química , Fitoquímicos/química , Taninos/química
12.
J Sci Food Agric ; 97(13): 4285-4294, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28182278

RESUMEN

BACKGROUND: Freezing represents an important storage method for vegetal foodstuffs, such as cowpea pods, and thus the impact of this process on the chemical composition of these matrices arises as a prominent issue. In this sense, the phytochemical contents in frozen cowpea pods (i.e. at 6 and 9 months) have been compared with fresh cowpea pods material, with the samples being concomitantly assessed by Fourier-transform infrared spectroscopy (FTIR), both mid-infrared (MIR) and near infrared (NIR), aiming to evaluate the potential of these techniques as a rapid tool for the traceability of these matrices. RESULTS: A decrease in phytochemical contents during freezing was observed, allowing the classification of samples according to the freezing period based on such variations. Also, MIR and NIR allowed discrimination of samples: the use of the first derivative demonstrated a better performance for this purpose, whereas the use of the normalized spectra gave the best correlations between the spectra and specific contents. In both cases, NIR displayed the best performance. CONCLUSION: Freezing of cowpea pods leads to a decrease of phytochemical contents, which can be monitored by FTIR spectroscopy, both within the MIR and NIR ranges, whereas the use of this technique, in tandem with chemometrics, constitutes a suitable methodology for the traceability of these matrices. © 2017 Society of Chemical Industry.


Asunto(s)
Espectroscopía Infrarroja por Transformada de Fourier/métodos , Vigna/química , Conservación de Alimentos , Almacenamiento de Alimentos , Congelación , Fitoquímicos/análisis
13.
Food Chem ; 190: 896-903, 2016 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-26213054

RESUMEN

A number of traditional liqueurs are obtained by maceration of red fruits in aqueous ethanol liquor, namely sloe berries or sour cherry. On the other hand, the exploration of residual plant material derived from the winery industry (grape (Vitis vinifera L.) stems), which has been regarded as an interesting source of colored and uncolored (poly)phenols, could lead to an industrial alternative to the traditional distilled spirits produced, with valuable physicochemical and phytochemical properties. In the present work, vinification residues (grape stems) were used to produce a new beverage. The evaluation of the physic-chemical characteristics and phytochemical composition as well as the evolution of the determined parameters during maceration (90 and 180 days) allowed a number of interesting bioactive compounds to be identified. This new beverage is a liqueur with a high retention of phenolic compounds (ortho-diphenols, flavanols, flavonols, and anthocyanins), with interesting physic-chemical characteristics, that revealed significant antioxidant activity.


Asunto(s)
Vitis/química , Vino/análisis , Antocianinas/análisis , Antioxidantes/farmacología , Color , Concentración de Iones de Hidrógeno , Fenoles/análisis , Extractos Vegetales/farmacología , Tallos de la Planta/química
14.
J Oleo Sci ; 64(10): 1083-93, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26440928

RESUMEN

Olive (Olea europaea L.) represents one of the most important and ancient crops in the Mediterranean countries, being widely known due to the optimal organoleptic characteristics of its oil, besides the important health benefits assigned to this product in the last few years. Since olive oil composition, respecting specific trace elements, has a direct impact on the quality and safety of this product, eleven monovarietal and twelve commercial olive oils were analysed spectrometrically concerning their metal composition. Regarding quality parameters, the monovarietal olive oils display larger quantities of Mg, Fe, Mn, while the commercial samples are characterized by greater amounts of Na, Ca, Cu and Zn. In which respects to safety parameters, the commercial samples present higher values for Al and Pb, and lower quantities of Cd, respecting the monovarietal ones. The assessment of the values observed for the trace elements, resorting to multivariate statistical methods, allowed to clearly distinguish the type of olive oil production-monovarietal or commercial blend. For this purpose, besides Cluster analysis, the data have been subjected to Principal Component Analysis-undertaken for either all the evaluated parameters simultaneously, or the quality/safety parameters separately, both data sets allowing the discrimination of the samples.


Asunto(s)
Aceite de Oliva/química , Oligoelementos/análisis , Calidad de los Alimentos , Inocuidad de los Alimentos , Análisis Multivariante , Portugal , Análisis Espectral
15.
Food Chem ; 174: 226-32, 2015 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-25529674

RESUMEN

A methodology based on Fourier transform infrared (FTIR) spectroscopy, combined with multivariate analysis methods, was applied in order to monitor extra virgin olive oils produced from three distinct cultivars on different maturation stages. For the first time, this kind of methodology is used for the simultaneous discrimination of the maturation stage, and different cultivars. Principal component analysis and discriminant analysis were utilised to create a model for the discrimination of olive oil samples. Partial least squares regression was employed to design calibration models for the determination of chemical parameters. The performance of these models was based on the multiple coefficient of determination (R(2)), the root mean square error of calibration (RMSEC) and root mean square error of cross validation (RMSECV). The prediction models for the chemical parameters resulted in a R(2) ranged from 0.93 to 0.99, a RMSEC ranged from 1% to 4% and a RMSECV from 2% to 5%. It has been shown that this kind of approach allows to distinguish the different cultivars, and to clearly discern the different maturation stages, in each one of these distinct cultivars. Furthermore, the results demonstrated that FTIR spectroscopy in tandem with chemometric techniques allows the creation of viable and accurate models, suitable for correlating the data collected by FTIR spectroscopy, with the chemical composition of the EVOOs, obtained by standard methods.


Asunto(s)
Aceites de Plantas/química , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Calibración , Análisis de los Mínimos Cuadrados , Análisis Multivariante , Aceite de Oliva
16.
Talanta ; 132: 829-35, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25476384

RESUMEN

Extra virgin olive oils produced from three cultivars on different maturation stages were characterized using Raman spectroscopy. Chemometric methods (principal component analysis, discriminant analysis, principal component regression and partial least squares regression) applied to Raman spectral data were utilized to evaluate and quantify the statistical differences between cultivars and their ripening process. The models for predicting the peroxide value and free acidity of olive oils showed good calibration and prediction values and presented high coefficients of determination (>0.933). Both the R(2), and the correlation equations between the measured chemical parameters, and the values predicted by each approach are presented; these comprehend both PCR and PLS, used to assess SNV normalized Raman data, as well as first and second derivative of the spectra. This study demonstrates that a combination of Raman spectroscopy with multivariate analysis methods can be useful to predict rapidly olive oil chemical characteristics during the maturation process.


Asunto(s)
Olea/química , Aceites de Plantas/análisis , Espectrometría Raman/métodos , Calibración , Interpretación Estadística de Datos , Análisis Discriminante , Concentración de Iones de Hidrógeno , Análisis de los Mínimos Cuadrados , Análisis Multivariante , Olea/clasificación , Olea/crecimiento & desarrollo , Olea/metabolismo , Aceite de Oliva , Peróxidos/análisis , Peróxidos/metabolismo , Análisis de Componente Principal , Especificidad de la Especie
17.
Phys Chem Chem Phys ; 16(16): 7491-500, 2014 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-24626795

RESUMEN

The conformational preferences and hydrogen-bonding motifs of several potential chemopreventive hydroxycinnamic derivatives were determined by inelastic neutron scattering spectroscopy. The aim is to understand their recognized beneficial activity and establish reliable structure-activity relationships for these types of dietary phytochemicals. A series of phenolic acids with different hydroxyl/methoxyl ring substitution patterns were studied: trans-cinnamic, p-coumaric, m-coumaric, trans-caffeic and ferulic acids. Their INS spectra were completely assigned by theoretical calculations performed at the Density Functional Theory level, for the isolated molecule, dimeric centrosymmetric species and the solid (using plane-wave expansion approaches). Access to the low energy vibrational region of the spectra enabled the identification of particular modes associated with intermolecular hydrogen-bonding interactions, which are the determinants of the main conformational preferences and antioxidant capacity of these systems.


Asunto(s)
Hidroxibenzoatos/química , Antioxidantes/química , Enlace de Hidrógeno , Difracción de Neutrones , Teoría Cuántica
19.
J Mol Model ; 13(8): 865-77, 2007 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-17340115

RESUMEN

The conformational preferences of several potential anticancer dihydroxycinnamic esters with a variable length alkyl chain were studied by quantum-mechanical (DFT) calculations (both for the isolated molecule and for aqueous solutions). The orientation of the hydroxyl ring substituents and of the alkyl ester moiety relative to the carbonyl group showed these to be the most determinant factors for the overall stability of this type of phenolic systems, strongly dependent on an effective pi-electron delocalization. Compared to the parent caffeic acid (dihydroxycinnamic acid), esterification was found to lead to a higher conformational freedom, and to affect mainly the energy barrier corresponding to the (O=)C-OR internal rotation. No particular differences were verified to occur upon lengthening of the ester alkyl chain, except when this is branched instead of linear. The vibrational spectra of the whole series of compounds were simulated, based on their calculated harmonic vibrational frequencies, and a preliminary assignment was performed.


Asunto(s)
Antineoplásicos/química , Ácidos Cumáricos/química , Ésteres , Modelos Moleculares , Conformación Molecular , Fenol
20.
J. bras. med ; 89(4): 77-78, out. 2006. ilus
Artículo en Portugués | LILACS | ID: lil-447733

RESUMEN

Os pseudocisto liquóricos abdominais são complicações relativamente infreqüentes das derivações ventriculoperitoneais. Apresentam etiopatogenia pouco compreendida e podem levar a sintomatologia importante. Devido a tais fatos, existem poucos casos relatados na literatura. O presente estudo tem por objetivos apresentar dois cados de pseudocistos liquóricos diagnosticados e tratados em nosso serviço, bem como realizar uma revisão de literatura sobre tal patologia


Asunto(s)
Humanos , Derivación Ventriculoperitoneal/efectos adversos , Derivación Ventriculoperitoneal/métodos , Derivación Ventriculoperitoneal , Hidrocefalia , Líquido Cefalorraquídeo , Diagnóstico Diferencial
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