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51.
Manuel Brenes Francisco J. Hidalgo Aranzazu García José J. Rios Pedro García Rosario Zamora Antonio Garrido 《Journal of the American Oil Chemists' Society》2000,77(7):715-720
Polyphenols of olive oil show autoprotective, sensory, and nutritional-therapeutic effects. Two new phenolic compounds have
been isolated from virgin olive oils by preparative high-performance liquid chromatography and their structures established
on the basis of their mass spectra and nuclear magnetic resonance spectral data. The compounds identified are the lignans
pinoresinol and 1-acetoxypinoresinol. Both have been found in all the commercial virgin olive oils analyzed. Pinoresinol concentration
was rather similar in all the oils. In contrast, 1-acetoxypinoresinol concentration was higher in oils of the Arbequina and
Empeltre cultivars than in Picual or Picudo cultivars. Pinoresinol and 1-acetoxypinoresinol may represent the major phenolic
compounds in some Arbequina and Empeltre oils. Lignans possess biological and pharmacological properties and, therefore, the
two new compounds identified in olive oils may contribute to the reported beneficial effects which are attributed to polyphenols
on human health of a diet rich in olive oil. 相似文献
52.
This study is aimed at the thermal analysis of sealant mortar (usually a mixtures of bentonite and cemem with addition of sand) used in geothermal cooling and heating. In particular, thermal conductivity and diffusivity measurements were performed on differem sealant mixtures by using Hot Disk thermal constants analyzer in order to identify the interesting thermal properties of grouting materials. The grouting materials that we considered are of porous nature and, if used in the presence of groundwater, have different levels of imbibitions. It is important to know the thermal behavior of these materials at different water content. A first set of measurements was performed on a not-tinted material at room temperature; then the samples were led to saturation conditions by contact capillary imbibitions with a cotton wool layer moistened in water. The determination of thermal conductivity in these test conditions appears to be critical compared to the measuremems on non-timed sample. The thermal conductivity tests have revealed how the thermal behavior of the samples analyzed is essentially determined by the density and water content of the material: in fact, the thermal conductivity increases of two to three times the value of the not-tinted material. 相似文献
53.
A study was carried out to increase the CLA contents in ewes’ milk fat under field conditions by dietary means and to investigate
the extent of the changes and consequences for milk processing and cheese quality. During a 3-mon period, ewes’ bulk milk
samples were collected every week from two different herds. For the first 4 wk the ewes were fed a conventional diet. Then
the following 6 wk a supplement enriched in α-linolenate (whole linseed) was incorporated into the ovine diet. Finally, in
the last 3 wk the feeding was the same as in the first 4 wk. The FA profile in milk fat was monitored by GC, and the distribution
of CLA isomers was thoroughly tested by combining GC-MS of 4,4-dimethyloxazoline derivatives (DMOX) with silver ion-HPLC (Ag+-HPLC) of FAME. Reconstructed mass spectral profiles of CLA characteristic ions from DMOX were used to identify positional
isomers, and Ag+-HPLC was used to quantify them. An increase in total CLA in milk fat was observed, and total CLA remained elevated during
the weeks of enriched α-linolenate feeding. In our experimental conditions there was a linear relationship between trans-vaccenic acid (trans-11-octadecenoic acid; trans-11 18∶1) and 9-cis, 11-trans CLA in ewes’ milk fat. Concerning the CLA isomer profile, increases in the 11,13- and 12,14–18∶2 positional isomers were
considerable when linseed was included in the diet. Organoleptic characteristics of cheeses made with CLA-enriched milk did
not substantially differ from those made with nonsupplemented ewes’ milk. CLA total content and isomer profile did not change
during ripening. 相似文献
54.
Andr Neto Carlos Silva Jorge Sousa Horcio Fernandes Carlos Hidalgo Jose Luis De Pablos Sophie Salasca Jean-Marcel Travre Jonathan B. Lister 《Fusion Engineering and Design》2009,84(7-11):1412-1415
The amount of data generated by the infra-red and visible cameras at ITER is expected to be considerably larger than most diagnostics. ITER will have 12 infra-red cameras plus 12 visible cameras in four different equatorial port plugs. Each of the ports will have a Plant System Host (PSH) that will provide a standard image of the plant system to the ITER's Control and Data Access and Communication (CODAC) system.The two key functions of these cameras will be the scientific exploitation with the detection of interesting physics events and the operational protection of the machine, namely the first wall. Already assuming high bandwidth requirements for both audio and video, ITER will provide a separate network for this kind of communication, which will be used to transmit both the experimental and informational data provided by the cameras.This paper presents the current camera plant system design and its interaction with ITER CODAC system and networks. Starting from the camera specifications several alternatives for data collection and compression are discussed. The required inputs from CODAC and a first specification for the internal finite state machine are also presented. Finally, a possible hardware straw man design solution for the plant system hardware is proposed. 相似文献
55.
Use of β-hydroxyacyl-CoA-dehydrogenase (HADH) activity to differentiate frozen from unfrozen fish and shellfish 总被引:1,自引:0,他引:1
Manuela Fernández Sergio Mano Gonzalo D. García de Fernando Juan A. Ordóñez L. Hoz 《European Food Research and Technology》1999,209(3-4):205-208
Further work on an enzymic method to differentiate frozen from unfrozen fish and shellfish is reported. The method is based
on the release of the β-hydroxyacyl-CoA-dehydrogenase (HADH) from mitochondria during freezing. Enzymic activity was evaluated
in fresh and frozen thawed samples from sole (Solea solea), sea bream (Pagellus centrodontus), hake (Merluccius merluccius), gilt headed bream (Sparus aurata), sea bass (Dicentrarchus labrax), salmon (Salmo salar), prawn (Penaeus japonicus) and Norwegian lobster (Nephrops norvegicus). Changes in the HADH activity of fresh and frozen thawed samples were compared after freezing at –196 °C for 15 min. Two
values were obtained: U (by dividing: HADH activity of samples frozen at –196 °C, then thawed/HADH activity of unfrozen samples) and F (by dividing: HADH activity of samples frozen at –18 °C, thawed, then frozen at –196 °C /HADH activity of samples frozen
at –18 °C, then thawed). Statistical analysis showed significant differences (P≤0.05) between both quotients for gilt headed bream, salmon, sea bream, sole and prawn, and an arbitrary limit was set at
2 to differentiate frozen thawed from unfrozen samples. The application of this limit made it possible to discriminate the
unfrozen from the frozen thawed state of around 90% of the total samples analysed. Best results were obtained for prawn (100%
of samples differentiated). In the present paper, a laboratory routine is proposed based on the comparison of the HADH activity
of a sample analysed straight away and that of a sample frozen at –196 °C and then thawed. The reported method is simple
and fast. The entire laboratory procedure can be performed in 45 min.
Received: 20 July 1998 / Revised version: 2 November 1998 相似文献
56.
Chandolia RK Luetjens CM Wistuba J Yeung CH Nieschlag E Simoni M 《Reproduction (Cambridge, England)》2006,132(2):355-363
Data on pubertal maturation in male marmoset, a model for human reproduction, are scant and conflicting. We collected data on novel parameters to characterize puberty. Twenty-five marmoset monkeys were assigned to five age groups by weeks (wk): 21 (pre-pubertal), 43 (onset of puberty), 52 (fully pubertal), 70 (mature), and 116 (fully adult). Serum and intratesticular testosterone and pituitary bioactive chorionic gonadotropin (bioCG) were measured. Testicular development was assessed by ultrasonography, histology, and flow cytometry. Three consecutive blood samples revealed extreme fluctuations in testosterone concentrations, suggesting an erratic secretion. Age-related changes in serum testosterone and pituitary bioCG concentrations were observed. Intratesticular androgens (ITAs) showed high fluctuations within groups at all ages and were high in some animals by 21 wk. Unexpectedly, no correlation between pituitary bioCG and serum testosterone or ITAs was found, but these parameters significantly correlated with testicular weight and volume. These observations were consistent a dependence on the testis growth on bioCG. Unfortunately, the low serum levels of bioCG were not measurable in this study. At 43 wk, the animals reached puberty. At 52 wk of age, animals attained maximum body and epididymal weights and qualitatively normal spermatogenesis, but testes continued growing, reaching a maximum of all parameters at 70 wk of age, without further major changes at the age of 116 wk. It is concluded that (1) gonadal activation is evident at wk 21, (2) the male marmoset reaches the pubertal threshold around 43 wk of age, attains qualitative parameters at 52 wk, matures further to sexual maturity at 70 wk, and (3) serum testosterone and ITAs are highly variable without any identifiable correlation with pituitary bioCG. 相似文献
57.
Clemente Neves Sousa Paulo Teles Vanessa Filipa Ferreira Dias João Luís Alves Apóstolo Maria Henriqueta Jesus Silva Figueiredo Maria Manuela Martins 《Hemodialysis international. International Symposium on Home Hemodialysis》2014,18(3):695-699
Vascular access is one of the leading causes of mobilization of financial resources in health systems for people with chronic kidney disease on hemodialysis. Physical examination of the arteriovenous fistula (AVF) has demonstrated its effectiveness in identifying complications. We decided to evaluate the influence of nurses' professional experience in the detection of complications of the AVF (venous stenosis and steal syndrome). The study took place in eight hemodialysis centers between May and September of 2011 in the north of Portugal. Sample was constituted by registered nurses. The nurses involved in the experiment were divided in two groups: those who had more than 5 years of experience and those who had less than 5 years of experience. Ninety‐two nurses participated in the study: 34 nurses had less than 5 years of professional experience and 58 had more than 5 years of professional experience. In the practices considered by nurses in the detection of venous stenosis, there were no differences observed between the groups (P > 0.05). In steal syndrome, there were no differences observed between the groups in the practices of the nurses in the detection of this complication of the AVF (P > 0.05). We concluded that professional experience does not influence the detection of venous stenosis and steal syndrome. 相似文献
58.
M. Acevedo I. Zuriguel D. Maza I. Pagonabarraga F. Alonso-Marroquin R. C. Hidalgo 《Granular Matter》2014,16(4):411-420
We present experimental and numerical results for particle alignment and stress distribution in packings of faceted particles deposited in a small-scale bi-dimensional silo. First, we experimentally characterize the deposits’ morphology in terms of the particles’ aspect ratio and feeding rate. Then we use the experimental results to validate our discrete element method (DEM) based on spheropolygons. After achieving excellent agreement, we use contact forces and fabric provided by the simulations to calculate the coarse-grained stress tensor. For low feeding rates, square particles display a strong tendency to align downwards, i.e., with a diagonal parallel to gravity. This morphology leads to stress transmission towards the walls, implying a quick development of pressure saturation, in agreement with the Janssen effect. When the feed rate is increased, both the disorder and the number of horizontal squares in the silo increase, hindering the Janssen effect. Conversely, for elongated particles the feed rate has a weak effect on the final deposit properties. Indeed, we always observe highly ordered structures of horizontal rods where the stress is transmitted mainly in the vertical direction. 相似文献
59.
A. Wojciechowski M. Manuela M. Raposo M. Cidália R. Castro W. Kuznik I. Fuks-Janczarek M. Pokladko-Kowar F. Bureš 《Journal of Materials Science: Materials in Electronics》2014,25(4):1745-1750
Novel nonlinear optical (NLO) materials based on six novel NLO chromophores featuring di(tri)cyanovinyl acceptor linked to (bi)thiophene heterocyclic donor system were fabricated for the first time in polymethyl methacrylate matrices with a 1,064 nm laser working in the 20 ns time pulse regime. Absorption spectra and DFT calculations were also done. This multidisciplinary study showed that tayloring of the optical (linear and nonlinear) properties in the desired direction can be achieved by increasing the length of the π-conjugated heterocyclic system (thiophene vs. bithiophene), the strength of the electron donor groups (H → MeO/EtO → Et2N) as well as the strength of the electron acceptor moieties (dicyanovinyl vs. tricyanovinyl, two vs. three electron withdrawing cyano groups). Due to the relatively high and tunable second-order susceptibilities (0.08–6.45 pm/V at wavelength 1,064 nm), the studied push–pull chromophores can be denoted as promising second-order NLO chromophores. 相似文献
60.
Nuria Hidalgo Mauricio E. Calvo Hernán Míguez 《Small (Weinheim an der Bergstrasse, Germany)》2009,5(20):2309-2315
A synthetic route is presented to attain high‐optical‐quality multilayered structures that result from coupling ordered mesoporous titanium oxide thin films to the surface of a dense one‐dimensional photonic crystal. Such architectures present spectrally well‐defined photon resonant modes localized in the outer coating that finely respond to physicochemically induced modifications of its pore volume. The potential of these porous coatings in detection of environmental changes through variations of the photonic response of the ensemble is demonstrated by performing isothermal optical reflectance measurements under controlled vapor‐pressure conditions. 相似文献