The effect of thermal treatment on the enhancement of detection of adulteration in extra virgin olive oils by synchronous fluorescence spectroscopy and chemometric analysis.

In this study the effect of thermal treatment on the enhancement of synchronous fluorescence spectroscopic method for discrimination and quantification of pure extra virgin olive oil (EVOO) samples from EVOO samples adulterated with refined oil was investigated. Two groups of samples were used. One group was analyzed at room temperature (25 °C) and the other group was thermally treated in a thermostatic water bath at 75 °C for 8h, in contact with air and with light exposure, to favor oxidation. All the samples were then measured with synchronous fluorescence spectroscopy. Synchronous fluorescence spectra were acquired by varying the wavelength in the region from 250 to 720 nm at 20 nm wavelength differential interval of excitation and emission. Pure and adulterated olive oils were discriminated by using partial least-squares discriminant analysis (PLS-DA). It was found that the best PLS-DA models were those built with the difference spectra (75 °C-25 °C), which were able to discriminate pure from adulterated oils at a 2% level of adulteration of refined olive oils. Furthermore, PLS regression models were also built to quantify the level of adulteration. Again, the best model was the one built with the difference spectra, with a prediction error of 3.18% of adulteration.

Development of new UV-vis spectroscopic microwave-assisted method for determination of glucose in pharmaceutical samples.

A new UV-Visible spectroscopic method assisted with microwave for the determination of glucose in pharmaceutical formulations was developed. In this study glucose solutions were oxidized by ammonium molybdate in the presence of microwave energy and reacted with aniline to produce a colored solution. Optimum conditions of the reaction including wavelength, temperature, and pH of the medium and relative concentration ratio of the reactants were investigated. It was found that the optimal wavelength for the reaction is 610 nm, the optimal reaction time is 80s, the optimal reaction temperature is 160°C, the optimal reaction pH is 4, and the optimal concentration ratio aniline/ammonium molybdate solution was found to be 1:1. The limits of detection and quantification of the method are 0.82 and 2.75 ppm for glucose solution, respectively. The use of microwaves improved the speed of the method while the use of aniline improved the sensitivity of the method by shifting the wavelength.

Simultaneous determination of aflatoxins B2 and G2 in peanuts using spectrofluorescence coupled with parallel factor analysis.

In the present study a method for the simultaneous determination of aflatoxins B2 and G2 in peanuts has been developed. The method uses second order standard addition method and excitation-emission fluorescence data together with parallel factor analysis (PARAFAC). The aflatoxin analysis was based on extraction with methanol-water and carried out using immunoaffinity clean-up. The results of PARAFAC on a set of spiked and naturally contaminated peanuts indicated that the two aflatoxins could be successfully determined. The method was validated and analytical figures of merit were obtained for both analytes. The limits of detection (LOD) were 0.05 and 0.04 µg kg(-1) for aflatoxins B2 and G2, respectively. The limits of quantification (LOQ) were 0.16 and 0.12 µg kg(-1) for aflatoxins B2 and G2, respectively. Coupling of spectrofluorimetry with PARAFAC can be considered as an alternative method for quantification of aflatoxins in the presence of unknown interferences obtained through analysis of highly complex matrix of peanuts samples at a reduced cost per analysis.

Objective chemical fingerprinting of oil spills by partial least-squares discriminant analysis.

An objective method based on partial least-squares discriminant analysis (PLS-DA) was used to assign an oil lump collected on the coastline to a suspected source. The approach is an add-on to current US and European oil fingerprinting standard procedures that are based on lengthy and rather subjective visual comparison of chromatograms. The procedure required an initial variable selection step using the selectivity ratio index (SRI) followed by a PLS-DA model. From the model, a "matching decision diagram" was established that yielded the four possible decisions that may arise from standard procedures (i.e., match, non-match, probable match, and inconclusive). The decision diagram included two limits, one derived from the Q-residuals of the samples of the target class and the other derived from the predicted y of the PLS model. The method was used classify 45 oil lumps collected on the Galician coast after the Prestige wreckage. The results compared satisfactorily with those from the standard methods.

Dynamic epigenetic regulation of the microRNA-200 family mediates epithelial and mesenchymal transitions in human tumorigenesis.

Epithelial-mesenchymal (EMT) and mesenchymal-epithelial (MET) transitions occur in the development of human tumorigenesis and are part of the natural history of the process to adapt to the changing microenvironment. In this setting, the miR-200 family is recognized as a master regulator of the epithelial phenotype by targeting ZEB1 and ZEB2, two important transcriptional repressors of the cell adherence (E-cadherin) and polarity (CRB3 and LGL2) genes. Recently, the putative DNA methylation associated inactivation of various miR-200 members has been described in cancer. Herein, we show that the miR-200ba429 and miR-200c141 transcripts undergo a dynamic epigenetic regulation linked to EMT or MET phenotypes in tumor progression. The 5'-CpG islands of both miR-200 loci were found unmethylated and coupled to the expression of the corresponding miRNAs in human cancer cell lines with epithelial features, such as low levels of ZEB1/ZEB2 and high expression of E-cadherin, CRB3 and LGL2, while CpG island hypermethylation-associated silencing was observed in transformed cells with mesenchymal characteristics. The recovery of miR-200ba429 and miR-200c141 expression by stable transfection in the hypermethylated cells restored the epithelial markers and inhibited migration in cell culture and tumoral growth and metastasis formation in nude mice. We also discovered, using both cell culture and animal models, that the miR-200 epigenetic silencing is not an static and fixed process but it can be shifted to hypermethylated or unmethylated 5'-CpG island status corresponding to the EMT and MET phenotypes, respectively. In fact, careful laser microdissection in human primary colorectal tumorigenesis unveiled that in normal colon mucosa crypts (epithelia) and stroma (mesenchyma) already are unmethylated and methylated at these loci, respectively; and that the colorectal tumors undergo selective miR-200 hypermethylation of their epithelial component. These findings indicate that the epigenetic silencing plasticity of the miR-200 family contributes to the evolving and adapting phenotypes of human tumors.

Discrimination and sensory description of beers through data fusion.

Beer samples of the same brand and commercialized as a same product, but brewed in four different factories were analyzed with three techniques, an MS e-nose, a mid-IR optical-tongue and a UV-visible, to see if the factories show differences and to find out if the differences found could be attributed to different sensory properties. The data from the three instruments were fused to improve the ability of classification with respect to the individual use of the techniques. Two levels of data fusion were studied: low and mid level fusion, and the classification was performed by linear discriminant analysis (LDA). Mid-level fusion provided better classification results (above 95% correct classification) than those of low-level fusion and also than those obtained when using the individual techniques. Moreover, by means of the score and loading plots obtained by Fisher-LDA, it was possible to interpret the chemical information provided by the three techniques, and we were able to relate the variables associated to each sensor to the main compounds responsible of the sensory perception.

Characterization and classification of the aroma of beer samples by means of an MS e-nose and chemometric tools.

An electronic nose based on coupling of headspace (HS) with a mass spectrometer (MS) has been used in this study to classify and characterize a series of beers according to their production site and chemical composition. With this objective, we analyzed 67 beers of the same brand and preparation process but produced in different factories. The samples were also subjected to sensory evaluation by a panel of experts. Linear discriminant analysis (LDA) was used as the classification technique and stepwise LDA based on Wilk's lambda criterion was used to select the most discriminating variables. To interpret the aroma characteristics of the beers from the m/z ions obtained, score and loading bi-plots were obtained by applying canonical variables. Because the beers analyzed were marketed with the same name and brand, we expected to be working with the same product irrespective of its origin. However, results from both sensory evaluation and use of the e-nose revealed differences between factories. With the e-nose it was possible to relate these differences to the presence (and abundance) of characteristic ions of different compounds typically found in beer. These results demonstrate that the HS-MS e-nose is not only an aroma sensor capable to classify and/or differentiate samples but it can also provide information about the compounds responsible for this differentiation.

Application of an electronic tongue based on FT-MIR to emulate the gustative mouthfeel "tannin amount" in red wines.

In this work, the ability of an electronic tongue based on Fourier-Transform Mid Infrared (FT-MIR) spectroscopy as a gustative sensor is assessed by emulating the responses of a tasting panel for the gustative mouthfeel "tannin amount". The FT-MIR spectra were modeled against the sensory responses evaluated in 37 red wines by means of partial least squares (PLS) regression models. In order to find the wavenumbers more correlated with the sensorial attribute and thus providing the best predictive models, six different variable selection techniques were tested. The iterative predictor weighting IPW-PLS technique showed the best results with the smallest RMSEC and RMSECV values (0.07 and 0.13, respectively) using 20 selected wavenumbers. The coincident wavenumbers selected by the six variable selection techniques were interpreted based on the absorption bands of tannin and then a calibration model using these wavenumbers was built to validate the interpretation made.

Uncertainty estimation in organic elemental analysis using information from proficiency tests.

We evaluate the uncertainty in organic elemental analysis of C, H, N, and S. We use data from six proficiency tests (PTs), in which some 35 Spanish laboratories participated. The uncertainty of the technique is estimated from the relative within-laboratory and between-laboratory variances for pure substances and samples with complex matrices (soil, powdered milk, oil, ash, and petroleum coke). We also calculate the relative standard uncertainties for individual laboratories when analysing pure substances using historical data from the participation of each laboratory in different editions of PTs. The uncertainty values obtained for the individual laboratories are comparable with the uncertainty of the technique and correlate with the combined z-scores. The evolution over time of those laboratories participating in common editions of PTs is also evaluated.

Resultados de un protocolo de rehabilitación respiratoria para pacientes sometidos a cirugía abdominal alta / Results of a respiratory rehabilitation protocol for patients undergoing upper abdominal surgery

Introducción y objetivos. Las complicaciones pulmonares postoperatorias (CPP) comportan un incremento en la morbimortalidad y en la estancia hospitalaria. Aunque la rehabilitación pulmonar reduce el porcentaje de CPP, no es posible aplicarla de manera generalizada en todos pacientes sometidos a cirugía abdominal. Nuestro propósito ha sido evaluar la eficacia de un protocolo terapéutico para reducir la incidencia de CPP. Pacientes y métodos. Se estudiaron prospectivamente 115 pacientes (62,6 ± 15,4 años) sometidos a cirugía abdominal procedente de un equipo quirúrgico colaborador. Los pacientes se estratificaron en 3 grupos (bajo, intermedio, elevado) según el riesgo predecible para sufrir CPP, teniendo en cuenta los factores de riesgo: edad, tabaquismo, índice de masa corporal, presencia y severidad de enfermedad pulmonar obstructiva crónica, duración prevista de la cirugía y tipo de cirugía. Se aplicó un protocolo de rehabilitación respiratoria que incluía ejercicios de expansión torácica para los niveles bajo, aerosolterapia para los del grupo intermedio y para los de riesgo elevado una pauta de fisioterapia respiratoria aplicada por el fisioterapeuta. Resultados. Un 51 % de los pacientes tenían un riesgo bajo, un 34 % moderado y un 24 % elevado. Las CPP se presentaron en un 10 % de los casos. Los pacientes que presentaban riesgo prequirúrgico leve precisaron menos días de ingreso comparados con los de riesgo moderado-alto (10,48 ± 7,3 frente a 14,46 ± 11,5; p < 0,05) y tenían una tendencia a complicarse menos (7,1 % frente a 13,2 %; p = 0,2). Conclusión. La aplicación de un protocolo para la prevención de CPP permite racionalizar los recursos humanos y materiales de un programa de rehabilitación respiratoria

Introduction and objectives. Postoperative pulmonary complications (PPCs) are associated with increased morbidity, mortality and hospital stay. Although pulmonary rehabilitation reduces the rate of PPCs, it cannot be systematically provided among all patients undergoing abdominal surgery. We have aimed to evaluate the efficacy of a therapeutic protocol to reduce the incidence of PPCs. Patients and methods. A prospective study of 115 patients (62.6 ± 15.4 years) undergoing abdominal surgery from an associated surgical team was carried out. The patients were stratified into 3 groups (low, intermediate and high) according to their predicted risk of developing PPC considering the risk factors of age, smoking, body mass index, chronic obstructive pulmonary disease, predicted length of the surgery and type of surgery. A pulmonary rehabilitation protocol was applied. This included thoracic expansion exercises for the low level of risk, inhaled therapy for the intermediate group, and an individualized respiratory physical therapy program for the high risk patients. Results. A total of 51 % were low risk patients, 34 % intermediate and 24 % were high risk. The incidence of PPCs was 10 % in general. Those patients with lower risk required a shorter hospital stay than those with intermediate and high risk (10.48 ± 7.3 vs. 14.46 ± 11.5; p < 0.05) and had a tendency for lower PPC rate (7.1 % vs. 13.2 %; p = 0.2). Conclusions. A specific protocol designed to prevent PPC allows for better distribution for human and material efforts for a respiratory rehabilitation program

Resultados de un protocolo de rehabilitación respiratoria para pacientes sometidos a cirugía abdominal alta / Results of a respiratory rehabilitation protocol for patients undergoing upper abdominal surgery

Resumen.—Introducción y objetivos. Las complicacionespulmonares postoperatorias (CPP) comportan un incrementoen la morbimortalidad y en la estancia hospitalaria. Aunque la rehabilitación pulmonar reduce el porcentaje de CPP, no es posible aplicarla de manera generalizada en todos pacientes sometidos a cirugía abdominal. Nuestro propósito ha sido evaluar la eficacia de un protocolo terapéutico para reducir la incidencia de CPP.Pacientes y métodos. Se estudiaron prospectivamente 115 pacientes (62,6 ± 15,4 años) sometidos a cirugía abdominal procedente de un equipo quirúrgico colaborador. Los pacientes se estratificaron en 3 grupos (bajo, intermedio, elevado) según el riesgo predecible para sufrir CPP, teniendo en cuenta los factores de riesgo: edad, tabaquismo, índice de masa corporal,presencia y severidad de enfermedad pulmonar obstructivacrónica, duración prevista de la cirugía y tipo de cirugía. Se aplicó un protocolo de rehabilitación respiratoria que incluía ejercicios de expansión torácica para los niveles bajo, aerosolterapia para los del grupo intermedio y para los de riesgo elevado una pauta de fisioterapia respiratoria aplicadapor el fisioterapeuta.Resultados. Un 51 % de los pacientes tenían un riesgo bajo, un 34 % moderado y un 24 % elevado. Las CPP se presentaron en un 10 % de los casos. Los pacientes que presentaban riesgo prequirúrgico leve precisaron menos días de ingreso comparados con los de riesgo moderado-alto (10,48 ± 7,3 frente a 14,46 ± 11,5; p < 0,05) y tenían una tendencia a complicarse menos (7,1 % frente a 13,2 %; p = 0,2).Conclusión. La aplicación de un protocolo para la prevención de CPP permite racionalizar los recursos humanos y materiales de un programa de rehabilitación respiratoria

Introduction and objectives. Postoperative pulmonary complications (PPCs) are associated with increased morbidity, mortality and hospital stay. Although pulmonary rehabilitation reduces the rate of PPCs, it cannot be systematically provided among all patients undergoing abdominal surgery. We have aimed to evaluate the efficacy of a therapeutic protocol to reduce the incidence of PPCs.Patients and methods. A prospective study of 115 patients(62.6 ± 15.4 years) undergoing abdominal surgery from an associated surgical team was carried out. The patients were stratified into 3 groups (low, intermediate and high) according to their predicted risk of developing PPC considering the risk factors of age, smoking, body mass index, chronic obstructive pulmonary disease, predicted length of the surgery and type of surgery. A pulmonary rehabilitation protocol was applied.This included thoracic expansion exercises for the low level of risk, inhaled therapy for the intermediate group, and an individualized respiratory physical therapy program for the high risk patients.Results. A total of 51 % were low risk patients, 34 % intermediate and 24 % were high risk. The incidence of PPCs was 10 % in general. Those patients with lower risk required a shorter hospital stay than those with intermediate and high risk (10.48 ± 7.3 vs. 14.46 ± 11.5; p < 0.05) and had a tendency for lower PPC rate (7.1 % vs. 13.2 %; p = 0.2).Conclusions. A specific protocol designed to prevent PPCallows for better distribution for human and material efforts for a respiratory rehabilitation program (AU)

Fast screening method for determining 2,4,6-trichloroanisole in wines using a headspace-mass spectrometry (HS-MS) system and multivariate calibration.

The system based on coupling a headspace sampler to a mass spectrometer (HS-MS), which is considered one kind of electronic nose, is an emergent technique for ensuring and controlling quality in industry. It involves injecting the headspace of the sample into the ionization chamber of the mass spectrometer where the analytes are fragmented. The result is a complex mass spectrum for each sample analyzed. When several samples are analyzed the data matrix generated is processed with chemometric techniques to compare and classify the substances from their volatile composition, in other words, to compare and classify their flavor. So far, information from electronic nose applications has mainly been qualitative. In this paper we present a quantitative study that uses a multivariate calibration. We analyzed several white wines using HS-MS to determine 2,4,6-tricholoranisole (TCA). This is an off-flavor that is a serious problem for the wine industry. The method is simple because it does not require sample preparation, only addition of sodium chloride being necessary for sample conditioning. Also, it provides a fast screening (10 min/sample) of the quantity of TCA in wines at ultratrace (sub microg L(-1)) levels.

Laparoscopic myotomy vs endoscopic dilation in the treatment of achalasia.

BACKGROUND: The aim of this study was to compare the results obtained in 14 patients with achalasia who underwent laparoscopic Heller's myotomy and Dor's fundoplication with those of 16 patients who had endoscopic dilation. METHODS: The diagnosis of achalasia was confirmed by manometry, endoscopy, and barium swallow. Esophageal symptoms were quantified before and after treatment using a clinical scale. Six patients had had endoscopic dilation prior to surgery. RESULTS: Before treatment, the patients in the surgical group complained of more severe dysphagia (median, 5; range, 0-5 vs median 4; range, 3-5) and chest pain (median, 3; range, 0-5 vs median, 1.5; range, 0-5), but both groups were comparable with respect to regurgitation, heartburn, and manometric results. Both groups achieved significant clinical improvement. The severity score decreased from 5 (range, 0-5) to 1 (range, 0-3) (p < 0.05) for dysphagia to solids in the laparoscopic group and from 4 (range, 3-5) to 1 (range, 0-5) (p < 0.05) in the endoscopic group. Lower esophageal sphincter (LES) basal pressure decreased significantly in both groups (from 29.3 to 11.8 mmHg in the laparoscopic group and from 28.9 to 16.5 mmHg in the endoscopic group). After treatment, there were no significant clinical differences between the two groups. Two patients in the surgical group were converted to open surgery. CONCLUSION: Laparoscopic myotomy is as save and effective as endoscopic dilation in the treatment of achalasia.