Aplicaciones de columnas capilares polares termoestables en cromatografía gaseosa

The composition, the effect of processing and storage, and the overall quality of food lipids can be evaluated by gas chromatography (GC). GC analyses are carried out on non-polar or polar capillary columns, which separate the various lipid components according to their polarity and boiling points. However, there are components with high-boiling points that require higher temperatures in order to be better resolved. Thermostable polar GC columns with a relatively low column bleeding, can be used for this scope. These columns generate GC traces with different separation characteristics, which can lead to the identification of components that cannot be completely resolved with non-polar GC columns. Thermostable polar GC columns are suitable for the separation of different lipid classes and can be utilised for a fast screening of the total unsaponifiable matter of the oil or lipid extract. A series of examples for the analysis of food lipids with thermostable polar GC columns, are here described.La composición, el efecto del procesamiento y el almacenamiento, y la calidad total de los alimentos grasos se pueden evaluar por cromatografía de gases (GC). El análisis cromatográfico se lleva a cabo con columnas capilares polares y apolares que separan los diferentes componentes lipídicos de acuerdo a su polaridad y punto de ebullición. Sin embargo, existen componentes con altos puntos de ebullición que requieren temperaturas más elevadas para lograr una mejor separación. Las columnas polares termoestables de cromatografía de gases con un “sangrado” relativamente bajo, se pueden usar para esta actividad. Estas columnas generan cromatogramas con características diferentes que pueden conducir a la identificación de componentes que no pueden ser completamente resueltos con columnas no polares. Las columnas polares termoestables de cromatografía de gases son óptimas para la separación de las diferentes clases de lípidos y pueden ser usadas para una visión rápida del total de la materia insaponificable del aceite o extracto lipídico. En este artículo se describen una serie de ejemplos de análisis de los lípidos de diferentes alimentos, llevados a cabo con columnas termoestables de cromatografía de gases

Impact of mild oven cooking treatments on carotenoids and tocopherols of cheddar and depurple cauliflower (Brassica oleracea L. var. Botrytis)

The effect of steam and sous-vide oven procedures on liposoluble antioxidants of colored cauliflower (orange and purple) was assessed for the first time and compared with domestic practice (boiling). In raw samples, the total carotenoid content was 10-fold higher in Cheddar than in Depurple (20.9 \ub1 2.1 vs. 2.3 \ub1 0.5 mg/kg dry weight), whereas the level of tocopherols was similar (28.5 \ub1 4.4 vs. 33 \ub1 5.2 mg/kg dry weight). The Cheddar liposoluble antioxidant matter contained violaxanthin, neoxanthin, \u3b1-carotene and \u3b4-tocopherol, not detected in Depurple. All tests increased the bioactive compounds extractability with steam oven and sous-vide displaying similar effects, lower than boiling. In boiled Cheddar cauliflower, the total carotenoids and tocopherols contents increased with cooking time until they were 13-fold and 6-fold more than in raw cauliflower, respectively. Conversely, in the Depurple variety, contents increased by half with respect to the orange variety. However, from a nutritional point of view, no differences were revealed among the three different cooking treatments in terms of vitamin A and E levels expressed in \u3bcg/100 g of fresh vegetable because of the higher water content of boiled samples that must be considered when evaluating the effect of thermal treatment on cauliflower nutritional traits

Milk and butter. From the Neolithic to the current nutritional aspects

The evolution in the history of nutrition knowledge towards dairy products, is strictly related to the socio-cultural development of humans. In fact, milk and butter have accompanied humans since ancient times, which traces of the consumption of such products are dated back about the earliest times after the last (glaciation) ice age, while the application for extra nutritional uses, such as cosmetics and ceremonial rites, are reported in the writings of the Old Testament. Even in Italy, before the Roman Empire, were known rudimentary techniques of production and storage of dairy products. But only with the advent of the Etruscans, and the Romans later, that the use of milk and dairy products reach a wide diffusion in several applications. Since the advent of Christ until today, milk and its derivatives have maintained a privileged place in the human diet, but it is only with the advent of modern medicine and new findings in lipidic chemistry that emerged multiple biological and nutritional properties, very important for human health. After a short summary of the ancient history of the milk and butter, the role of dairy products in cancer, in hypercholesterolemia, and cardiovascular disease are reported. Moreover, the current opinions on saturated fatty acids, the role of polyunsaturated fatty acids and their lipid mediators obtained by the action of cyclooxygenase, lipoxygenase and the cytochrome P450 enzymes, are treated. Even if sometimes mistreated, the milk, but most of all its high fat content derivatives such as butter, is a rich source of biologically active compounds that foster a controversial action against neolplastic and cardiovascular disease. These compounds, mainly contained in the lipid fraction, for the more obvious relationships that exist between nutrition and health status, have been the subject in the last decades of intense scientific investigation in which there were expressed lights and shadows, but recognizing that not all fats are harmful and further thorough studies are necessary, in particular, on the derived lipid mediators. This will allow a significant progress based on new scientific evidences, further orienting researchers and clinicians on evidencebased nutritional science

Constituyentes volátiles y estabilidad oxidativa de aceites vírgenes de oliva: influencia del batido de la pasta de aceitunas.

Olive crushing, olive-paste kneading and separation of the oil the most important technological steps in olive oil production since they directly influence the future quality of the product. The contact between the oil and the olive-paste increases lipolysis and lipid oxidation, which are mainly due to the highly-active lipases present in the paste and the lipoxygenase action, respectively. The choice of the technological parameters is directly related to the oil future stability and its organoleptic characteristics. This study confirms and emphasizes the fact that the oxidative degradation, simultaneously with the well-known formation of the flavor compounds, is related to the time required for the separation of the oil-water emulsion. Loss of the natural antioxidants (minor polar components) by an oxidative effect was demonstrated to be also influenced by the time required for oil separation.La molienda de aceitunas, el batido de la pasta y la separación del aceite de oliva producen una serie de transformaciones en las características del aceite que posteriormente será extraído. Es sabido que la formación de distintos componentes del aroma del aceite derivan de reacciones oxidativas enzimáticas. El contacto entre el aceite y la pasta de aceitunas incrementa la lipolisis y la oxidación lipídica, debido a un incremento de la actividad de las lipasas presentes en la pasta y a una acción lipoxigenásica respectivamente. La elección de los parámetros tecnológicos está en relación directa con la futura estabilidad y las características organolépticas del aceite. En este trabajo se confirma la formación de tales compuestos evidenciándose la degradación oxidativa del aceite en relación al tiempo de batido empleado. Se demuestra también una pérdida de antioxidantes (componentes polares menores) por efectos oxidativos en modo proporcional al tiempo de batido

Volatile constituents and oxidative stability of virgin olive oils: influence of the kneading of olive-paste.

La molienda de aceitunas, el batido de la pasta y la separacion del aceite de oliva producen una serie de transformaciones en las caracteristicas del aceite que posteriormente sera extraido. Es sabido que la formacion de distintos componentes del aroma del aceite derivan de reacciones oxidativas enzimaticas. El contacto entre el aceite y la pasta de aceitunas incrementa la lipolisis y la oxidacion lipidica, debido a un incremento de la actividad de las lipasas presentes en la pasta y a una accion lipoxigenasica respectivamente. La eleccion de los parametros tecnologicos esta en relacion directa con la futura estabilidad y las caracteristicas organolepticas del aceite. En este trabajo se confirma la formacion de tales compuestos evidenciandose la degradacion oxidativa del aceite en relacion al tiempo de batido empleado. Se demuestra tambien una perdida de antioxidantes (componentes polares menores) por efectos oxidatives en modo proporcional al tiempo de batido

Effets de la formation de la pourriture acide sur la composition de la fraction lipidique des différentes parties du grain de Vitis vinifera cv. Fortana

On a étudié par comparaison la composition de la fraction lipidique des différentes parties de grains de Vitis vinifera sains et attaqués par la pourriture acide.Des différences considérables ont été révélées entre les extraits des différents types d'échantillons de pulpe + peau en ce qui concerne les paramètres suivants: teneur en lipide, composition des triglycérides, composition des acides gras. Par contre, la fraction lipidique des deux échantillons de pépins était très semblable.Les composants principaux ainsi que leur répartition quantitative caractéristique correspondent aux résultats publiés dans une étude précédente. On a mis en évidence l'aldéhyde oléanoique qui n'était présente que dans quelques échantillons de pulpe + peau en même temps que l'acide correspondant et l'erythrodiol.Effects of sour rot on the composition of the lipid fraction of different parts of grapevine berries ( Vitis vinifera cv. Fortana)The composition of the lipid fraction of the various parts of berries of Vitis vinifera, healthy and infected by sour rot, have been compared. Notable differences became evident among the extracts of the various samples of pulp + skin with respect to the following parameters: lipid contens, composition of triglycerides and composition of fatty acids. The composition of the lipid fraction of the two samples of grape seeds, however, turned out to be very similar.The principal components and their quantitative distribution characteristics corresponded with the results reported in a preceding work. Oleanoic aldehyde has been identified which, together with the corresponding acid and erythrodiole, was only present in the samples of pulp + skin

Two Case Reports of Biliary Tract Injuries during Laparoscopic Cholecystectomy

Background and Study Aims. Biliary tract injuries (BTI) represent the most serious and potentially life-threatening complication of cholecystectomy occurring also during laparoscopic approaches. Patients and Methods. We describe and discuss two different cases of BTI occurring during laparoscopic cholecystectomy (LC). Results. Two patients developed BTI during LC and one evidenced the complication during the LC itself and was treated during the same LC in real time. The other patient evidenced BTI only after the primary intervention and was successfully reoperated in laparotomy after 10 days from the LC. Conclusions. The factors that predispose to the occurrence of BTI during cholecystectomy and the cautions to be used to prevent BTI are discussed

High-grade vaginal intraepithelial neoplasia and risk of progression to vaginal cancer. a multicentre study of the Italian Society of Colposcopy and Cervico-Vaginal Pathology (SICPCV)

OBJECTIVE: The aim of this study was to analyse the women with high grade vaginal intraepithelial neoplasia (HG-VaIN), in order to identify a subset of women at higher risk of progression to invasive vaginal cancer. MATERIALS AND METHODS: The medical records of all the women diagnosed with HG-VaIN, and subsequently treated, from January 1995 to December 2013 were analyzed in a multicentre retrospective case series. The rate of progression to invasive vaginal cancer and the potential risk factors were evaluated. RESULTS: 205 women with biopsy diagnosis of HG-VaIN were considered, with a mean follow up of 57 months (range 4-254 months). 12 cases of progression to vaginal squamocellular cancer were observed (5.8%), with a mean time interval from treatment to progression of 54.6 months (range 4-146 months). The rate of progression was significantly higher in women diagnosed with VaIN3 compared with VaIN2 (15.4% vs. 1.4%, p < 0.0001). Women with HG-VaIN and with previous hysterectomy showed a significantly higher rate of progression to invasive vaginal cancer compared to non-hysterectomised women (16.7% vs. 1.4%, p < 0.0001). A higher risk of progression for women with VaIN3 and for women with previous hysterectomy for cervical HPV-related disease was confirmed by multivariable logistic regression analysis. CONCLUSIONS: A higher rate of progression to vaginal cancer was reported in women diagnosed with VaIN3 on biopsy and in women with previous hysterectomy for HPV-related cervical disease. These patients should be considered at higher risk, thus a long lasting and accurate follow up is recommended

Rapid neuronal differentiation of induced pluripotent stem cells for measuring network activity on micro-electrode arrays

Neurons derived from human induced Pluripotent Stem Cells (hiPSCs) provide a promising new tool for studying neurological disorders. In the past decade, many protocols for differentiating hiPSCs into neurons have been developed. However, these protocols are often slow with high variability, low reproducibility, and low efficiency. In addition, the neurons obtained with these protocols are often immature and lack adequate functional activity both at the single-cell and network levels unless the neurons are cultured for several months. Partially due to these limitations, the functional properties of hiPSC-derived neuronal networks are still not well characterized. Here, we adapt a recently published protocol that describes production of human neurons from hiPSCs by forced expression of the transcription factor neurogenin-212. This protocol is rapid (yielding mature neurons within 3 weeks) and efficient, with nearly 100% conversion efficiency of transduced cells (>95% of DAPI-positive cells are MAP2 positive). Furthermore, the protocol yields a homogeneous population of excitatory neurons that would allow the investigation of cell-type specific contributions to neurological disorders. We modified the original protocol by generating stably transduced hiPSC cells, giving us explicit control over the total number of neurons. These cells are then used to generate hiPSC-derived neuronal networks on micro-electrode arrays. In this way, the spontaneous electrophysiological activity of hiPSC-derived neuronal networks can be measured and characterized, while retaining interexperimental consistency in terms of cell density. The presented protocol is broadly applicable, especially for mechanistic and pharmacological studies on human neuronal networks

Characterization of Large Volume 3.5 x 8 inches LaBr3:Ce Detectors

The properties of large volume cylindrical 3.5 x 8 inches (89 mm x 203 mm) LaBr3:Ce scintillation detectors coupled to the Hamamatsu R10233-100SEL photo-multiplier tube were investigated. These crystals are among the largest ones ever produced and still need to be fully characterized to determine how these detectors can be utilized and in which applications. We tested the detectors using monochromatic gamma-ray sources and in-beam reactions producing gamma rays up to 22.6 MeV; we acquired PMT signal pulses and calculated detector energy resolution and response linearity as a function of gamma-ray energy. Two different voltage dividers were coupled to the Hamamatsu R10233-100SEL PMT: the Hamamatsu E1198-26, based on straightforward resistive network design, and the LABRVD, specifically designed for our large volume LaBr3:Ce scintillation detectors, which also includes active semiconductor devices. Because of the extremely high light yield of LaBr3:Ce crystals we observed that, depending on the choice of PMT, voltage divider and applied voltage, some significant deviation from the ideally proportional response of the detector and some pulse shape deformation appear. In addition, crystal non-homogeneities and PMT gain drifts affect the (measured) energy resolution especially in case of high-energy gamma rays. We also measured the time resolution of detectors with different sizes (from 1x1 inches up to 3.5x8 inches), correlating the results with both the intrinsic properties of PMTs and GEANT simulations of the scintillation light collection process. The detector absolute full energy efficiency was measured and simulated up to gamma-rays of 30 Me