Seed oil triglyceride profiling of thirty-two hybrid grape varieties

Triglyceride profile of seed oil samples from 32 hybrid grape varieties not studied before was investigated. A new method for the analysis of triacylglycerols (TAGs) has been developed based on the direct infusion in the electrospray ionization (ESI) source and employing tetrahydrofuran/methanol/water (85:10:5 v|v|v) as solvent; the formation of [M?+?Na](+) ions in high yield has been observed. TAGs were identified by ESI-tandem mass spectrometry analysis, and the matrix-assisted-laser-desorption-ionization and time-of-flight profile of samples was determined. Six were the principal TAGs identified in seed oil: trilinolein (LLL) was the most abundant (43%), followed by dilinoleoyl-oleoylglycerol (LOL, 23%), and dilinoleoyl-palmitoylglycerol (LPL, 15%). Compounds present in lower concentration were LSL and LOO (11%), LOP (6%), and LSP (2%). Compared with seed oils produced from V. Vinifera grapes, some significant differences in the relative abundances of TAGs were found, in particular hybrid grape seed oils showed higher LOL and lower LPL content, respectively. Among the samples studied, a particularly high content of LLL (rich in unsaturated fatty acids) was found in seed oils from two red varieties. Copyright ? 2012 John Wiley & Sons, Ltd.     

A fast,efficient and automated method to extract vessels from fundus images

Abstract  

We present a fast, efficient, and automatic method for extracting vessels from retinal images. The proposed method is based on the second local entropy and on the gray-level co-occurrence matrix (GLCM). The algorithm is designed to have flexibility in the definition of the blood vessel contours. Using information from the GLCM, a statistic feature is calculated to act as a threshold value. The performance of the proposed approach was evaluated in terms of its sensitivity, specificity, and accuracy. The results obtained for these metrics were 0.9648, 0.9480, and 0.9759, respectively. These results show the high performance and accuracy that the proposed method offers. Another aspect evaluated in this method is the elapsed time to carry out the segmentation. The average time required by the proposed method is 3 s for images of size 565 × 584 pixels. To assess the ability and speed of the proposed method, the experimental results are compared with those obtained using other existing methods.     

Isotretinoin and Thalidomide Down-Regulate c-MYC Gene Expression and Modify Proteins Associated with Cancer in Hepatic Cells

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. The number of cases is increasing and the trend for the next few years is not encouraging. HCC is usually detected in the advanced stages of the disease, and pharmacological therapies are not entirely effective. For this reason, it is necessary to search for new therapeutic options. The objective of this work was to evaluate the effect of the drugs isotretinoin and thalidomide on c-MYC expression and cancer-related proteins in an HCC cellular model. The expression of c-MYC was measured using RT-qPCR and western blot assays. In addition, luciferase activity assays were performed for the c-MYC promoters P1 and P2 using recombinant plasmids. Dose-response-time analyses were performed for isotretinoin or thalidomide in cells transfected with the c-MYC promoters. Finally, a proteome profile analysis of cells exposed to these two drugs was performed and the results were validated by western blot. We demonstrated that in HepG2 cells, isotretinoin and thalidomide reduced c-MYC mRNA expression levels, but this decrease in expression was linked to the regulation of P1 and P1-P2 c-MYC promoter activity in isotretinoin only. Thalidomide did not exert any effect on c-MYC promoters. Also, isotretinoin and thalidomide were capable of inducing and repressing proteins associated with cancer. In conclusion, isotretinoin and thalidomide down-regulate c-MYC mRNA expression and this is partially due to P1 or P2 promoter activity, suggesting that these drugs could be promising options for modulating the expression of oncogenes and tumor suppressor genes in HCC.     

Predictive Multi Experiment Approach for the Determination of Conjugated Phenolic Compounds in Vegetal Matrices by Means of LC-MS/MS

Polyphenols (PCs) are a numerous class of bioactive molecules and are known for their antioxidant activity. In this work, the potential of the quadrupole/linear ion trap hybrid mass spectrometer (LIT-QqQ) was exploited to develop a semi-untargeted method for the identification of polyphenols in different food matrices: green coffee, Crocus sativus L. (saffron) and Humulus lupulus L. (hop). Several conjugate forms of flavonoids and hydroxycinnamic acid were detected using neutral loss (NL) as a survey scan coupled with dependent scans with enhanced product ion (EPI) based on information-dependent acquisition (IDA) criteria. The presented approach is focused on a specific class of molecules and provides comprehensive information on the different conjugation models that are related to specific base molecules, thus allowing a quick and effective identification of all possible combinations, such as mono-, di-, or tri-glycosylation or another type of conjugation such as quinic acid esters.     

Cation coordination induced modulation of the anion sensing properties of a ferrocene-imidazophenanthroline dyad: multichannel recognition from phosphate-related to chloride anions

A new chemosensor molecule 1 based on a ferrocene-imidazophenanthroline dyad, effectively recognizes aqueous hydrogenpyrophosphate and the organic anions ADP and ATP through three different channels. A cathodic shift of the ferrocene/ferrocenium oxidation wave (Delta E 1/2 ranging from -130 mV for hydrogenpyrophosphate and fluoride to -40 mV for ADP). A progressive red-shift of the absorption bands and/or appearance of a new low energy band at 314-319 nm. These changes in the absorption spectra are accompanied by color changes from pale yellow to orange or pink, which allow the potential for "naked eye" detection. The emission spectrum (lambda exc = 390 nm) undergoes an important chelation-enhanced fluorescence effect (CHEF = 50) in the presence of 2.5 equiv of hydrogenpyrophosphate anion and with a large excess of fluoride anion (CHEF = 114). Interestingly, the emission spectrum obtained at different excitation energy (lambda exc = 340 nm) in the presence of AcOH acid is red-shifted and not only perturbed by the hydrogenpyrophosphate anion (CHEF = 71) but also with the organic anions ATP (CHEF = 25), ADP (CHEF = 15), and the dihydrogenphosphate (CHEF = 25). The stable heterobimetallic ruthenium (II) complex 2 selectively senses the chloride anion over other anions examined through two channels: cathodic redox shift (Delta E 1/2 = -80 mV) of the Fe(II)/Fe(III) redox couple keeping the oxidation wave of the ruthenium (II) center unchanged and a significant red emission enhancement (CHEF = 30). (1)H and (31)P NMR studies as well as DFT calculations have been carried out to get information about which molecular sites are involved in bonding. About the deprotonation/coordination dualism, the combined electrochemical, absorption, emission, and NMR data strongly support that fluoride anion induces only deprotonation, anions dihydrogenphosphate, ATP, and ADP from hydrogen-bonded complexes and formation of hydrogen-bonded complex between receptor 1 and hydrogenpyrophosphate anion and deprotonation proceed simultaneously. In regards to receptor 2, all available data (electrochemical, absorption, emission, and 1H NMR) strongly support the formation of a [2. Cl ( - ) ] hydrogen-bonded complex.     

Necessary Optimality Conditions for Interval Optimization Problems with Functional and Abstract Constraints

Journal of Optimization Theory and Applications - This work addresses interval optimization problems in which the objective function is interval-valued while the constraints are given in functional...     

Correction of structured molecular background by means of high-resolution continuum source electrothermal atomic absorption spectrometry—Determination of antimony in sediment reference materials using direct solid sampling

A simple, fast and accurate procedure is proposed for the determination of antimony in certified sediment reference materials using direct solid sampling high-resolution continuum source electrothermal atomic absorption spectrometry and iridium as a permanent modifier. The less sensitive resonance line at 231.147 nm has been used in order to allow the introduction of larger sample mass. Six certified reference materials, one river, one estuarine and four marine sediments have been analyzed. The use of iridium as a permanent modifier caused an increase of 30% in sensitivity and stabilized antimony in the sediment to a pyrolysis temperature of 1100 °C. Significant background absorption with pronounced rotational fine structure was observed at the optimum atomization temperature of 2100 °C, which coincided with the analyte atomic absorption in time. This background was found to be due to the electron excitation spectra of mostly the SiO and in part the PO molecules, and could be eliminated by applying a least-squares background correction algorithm. A characteristic mass of 28 pg Sb was obtained, and the limit of detection (3σ, n = 10) was 0.02 μg g⁻¹, calculated for 0.2 mg of sample. The results obtained for six certified reference materials with concentrations between 0.40 and 11.6 ± 2.6 μg g⁻¹ Sb were in agreement with the certified values according to a Student's t-test for a 95% confidence level, using aqueous standards for calibration. The precision, expressed as relative standard deviation, ranged between 7% and 17% (n = 5).     

Simultaneous determination of Cd and Fe in sewage sludge by high-resolution continuum source electrothermal atomic absorption spectrometry with slurry sampling

This work describes the method development for the simultaneous determination of Cd and Fe using the main resonance line of Cd at 228.802 nm and a secondary Fe line at 228.725 nm, and high-resolution continuum source electrothermal atomic absorption spectrometry (HR-CS ET AAS). Two certified reference materials and two ‘real’ samples of industrial and domestic sewage sludge have been analyzed as slurries prepared in a mixture of HF and HNO₃. The simultaneous determination has been performed using a short temperature program of only 30 s, without a pyrolysis stage and with two atomization stages, at 1300 °C and 2300 °C, taking into consideration the significantly different thermal characteristics of Cd and Fe. Structured background, which is likely due to the presence of one or more diatomic molecules, including SiO, has been detected. However, there has been no spectral overlap between molecular bands and the atomic lines of Cd and Fe, making possible the determination to be carried out using only automatic correction for continuous background. Calibration against aqueous standards lead to good agreement between certified or informed values and the determined values, at a statistical confidence level of 95%; recovery tests were performed for real samples, resulting in recoveries ranging from 90 to 105%. Detection limits of 0.03 and 90 µg g^{− 1} for Cd and Fe, respectively, have been obtained, which are adequate for the purpose.