134 research outputs found
The Role of the Superior Order GLCM in the Characterization and Recognition of the Liver Tumors from Ultrasound Images
The hepatocellular carcinoma (HCC) is the most frequent malignant liver tumor. It often has a similar visual aspect with the cirrhotic parenchyma on which it evolves and with the benign liver tumors. The golden standard for HCC diagnosis is the needle biopsy, but this is an invasive, dangerous method. We aim to develop computerized,noninvasive techniques for the automatic diagnosis of HCC, based on information obtained from ultrasound images. The texture is an important property of the internal organs tissue, able to provide subtle information about the pathology. We previously defined the textural model of HCC, consisting in the exhaustive set of the relevant textural features, appropriate for HCC characterization and in the specific values of these features. In this work, we analyze the role that the superior order Grey Level Cooccurrence Matrices (GLCM) and the associated parameters have in the improvement of HCC characterization and automatic diagnosis. We also determine the best spatial relations between the pixels that lead to the highest performances, for the third, fifth and seventh order GLCM. The following classes will be considered: HCC, cirrhotic liver parenchyma on which it evolves and benign liver tumors
Untargeted Metabolomics for Sea Buckthorn (Hippophae rhamnoides ssp. carpatica) Berries and Leaves: Fourier Transform Infrared Spectroscopy as a Rapid Approach for Evaluation and Discrimination
Untargeted metabolomics coupled with chemometric analysis was applied to evaluate and discriminate six Romanian sea buckthorn (Hippophae rhamnoides L.) berries and leaves. Total carotenoids and total phenolics were determined quantitatively by UV-Vis spectrometry. The qualitative evaluation and discrimination was obtained using the FTIR fingerprints (by using Fourier Transform Infrared spectroscopy) of raw carotenoid and phenolic extracts. The average concentration of total carotenoids was 54 and 3.9 mg carotenoids/ 100g DW in berries and leaves, respectively. The average concentration of total phenolics was 746 mg GAE/100g DW in berries, approximately 1.8 times lower than total phenolics found in leaves. By PCA (Principal Component Analysis) of fingerprints (900-1800 cm-1), the responsible bands for samples discrimination were identified. In case of total carotenoids extract the biomarker bands were: 1745, 1743, 1500 cm-1 for berries and 1458 cm-1 and 1735 cm-1 for leaves, while for total phenolic extract the key bands were 1731, 1033, 1622 cm-1 for berries and 1047 cm-1, 1616, 1512 and 1454 cm-1 for leaves. FTIR spectroscopy proved to be a simple and sensitive analytical technique that can be successfully used in sample discrimination and classification
Anthocyanins-Smart Molecules for Cancer Prevention
Anthocyanins are one of the most widespread natural pigments in the plant kingdom. Being surrounded by so many fruits and vegetables rich in anthocyanins, it is recommended to consume a relatively large amount of them. A daily intake of anthocyanins has a certain demonstrated benefits: lowers the risk of cardiovascular disease, diabetes, arthritis, and cancer due, at least in part, to their antioxidant and anti-inflammatory activities. Lately, great attention is paid to their anticancer properties due to the need for user-friendly approaches to improve the treatment. So far, cancer had been nominated to be the second in top 10 diseases of the twenty-first century. Those colorful pigments have the ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression and can also inhibit the growth of cancer cells. However, the main concern related to the use of anthocyanins as anticancer agents is their poor bioavailability, more specific poor absorption, and biodistribution. In this chapter, the anticancer activities of anthocyanins or anthocyanin-rich extracts in vitro or in vivo were reviewed
Thermal Stability Study of the Grape Seeds Extracts in the Aqueous Solutions
This study was carried out to evaluate the effect of parameters the extraction process of grape seeds extracts on the bioactive compounds. The aqueous extracts were screened for total polyphenol content and total flavonoid content wich were determined spectrophotometrically using a modified Folin-Ciocalteu method, respectively a chromogenic system of NaNO2-Al (NO3)3-NaOH based method. The antioxidant activity was determined using DPPH method while their polyphenolic composition by means of HPLC-DAD- MS/ ESI(+) analysis. Total phenols content and flavonoid content varied between 37.835 and 31.830 mg GAE/g, 23.420 and 17.645 mg QE/g respectively in Fetească Neagră seeds; between 24.265 and 27.065 mg GAE/g, 17.970 and 15.205 mg QE/g respectively in Fetească Regală seeds. All extracts showed remarkable DPPH radical-scavenging activity ranging from 94.110 to 95.515%. The study revealed 14 phenolic compounds belonging to the following groups: flavan-3-ol monomers, proanthocyanidins, hydroxycinnamic acid and hydroxybenzoic acid derivatives. Quantitative differences among the varieties and the level of temperature applied of the extraction process were observed. The results suggested that the heat treatment of grape seeds liberated phenolic compounds having a significant effect in increasing the amounts of active when a 90°C extraction temperature was used
CO adsorption on neutral iridium clusters
The adsorption of carbon monoxide on neutral iridium clusters in the size
range of n = 3 to 21 atoms is investigated with infrared multiple photon
dissociation spectroscopy. For each cluster size only a single v(CO) band is
present with frequencies in the range between 1962 cm-1 (n = 8) and 1985 cm-1
(n = 18) which can be attributed to an atop binding geometry. This behaviour is
compared to the CO binding geometries on clusters of other group 9 and 10
transition metals as well as to that on extended surfaces. The preference of Ir
for atop binding is rationalized by relativistic effects on the electronic
structure of the later 5d metals
Dynamic and wear study of an extremely bidisperse magnetorheological fluid
Acceso a la versión publicada en Smart Mater. Struct. 24(12) 127001
(http://iopscience.iop.org/0964-1726/24/12/127001)"This is an author-created, un-copyedited version of an article accepted for publication/published in Smart Materials and Structures. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The Version of Record is available online at http://dx.doi.org/10.1088/0964-1726/24/12/127001."In this work the friction and wear properties of five magnetorheologicalfluids (MRFs)with varying compositions are investigated. Considering that many of the proposed applications for these fluids involve lubricated contact between mobile metal –metal or polymer– metal parts, the relationship between MR response and wear behavior appears to be of fundamental importance. One of the fluids(MR#1)contains only the iron microparticles and base oil; the second and third ones(MR#2 and MR#3) contain an anti-wear additive as well. The fourth one(MR#4)is a well known commercial MRF. Finally, MR#5 is stabilized by dispersing the iron particles in a magnetite ferrofluid. The MR response of the latter fluid is better(higher yield stress and post-yield viscosity)than that of the others. More importantly, it remains(and even improves)after the wear test: the pressure applied in the four-ball apparatus produces a compaction of the magnetite layer around the iron microparticles. Additionally, the friction coefficient is larger, which seems paradoxical in principle, but can be explained by considering the stability of MR#5 in comparison to the other four MRs, which appear to undergo partial phase separation during the test. In fact, electron and optical microscope observations confirm a milder wear effect of MR#5, with almost complete absence of scars from the steel test spheres and homogeneous
and shallow grooves on them. Comparatively, MR#2, MR#3 and, particularly, MR#1 produce a much more significant wear.MINECO Ramón y Cajal Programme (RYC-2014-16901)MINECO FIS 2013-07666-C3-1-RCEI Biotic BS27.2015Junta de Andalucía, PE2012-FQM-069
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