6,075 research outputs found
Use of microwave in chicken breast and application of different storage conditions: consequences on oxidation
Slices of chicken breast were subjected to microwave heating (750 W, 3 min) and further storage in different conditions (refrigeration at 4 °C and freezing at −18 °C combined with aerobic, vacuum, and modified atmosphere packaging). Evaluation of the intensity of the oxidation process was carried out. A 16-fold increment in the amount of cholesterol oxidation products (COP) was found as a consequence of microwave cooking (45.86 μg/g lipid after microwave and 2.88 μg/g lipid in raw samples). 7-ketocholesterol was the most affected COP by microwave, accounting for a 25% of the total COP. Storage of microwaved samples under aerobic refrigeration led to the highest oxidation status with the following values: peroxide 19.41 meqO2/kg lipid, TBA 0.32 ppm and COP 123.50 μg/g lipid. MAP refrigerated samples showed 50.94 μg/g lipid of total COP, an amount slightly higher than in vacuum conditions (46.81 μg/g lipid). Under frozen storage MAP and vacuum samples showed the lowest amounts of total COP (29.76 and 39.28 μg/g lipid, respectively)
Yellowtail flounder, redfish (Sebastes spp.) and witch flounder indices from the Spanish Survey conducted in Divisions 3NO of the NAFO Regulatory Area
Since 1995, Spain carries out a spring stratified random bottom trawl survey in Div. 3NO of the NAFO
Regulatory Area. Total mean catches, biomass and mean numbers for yellowtail flounder (Limanda ferruginea)
are presented for the period 1995-8 for redfish (Sebastes spp.) for the period 1997-2018 and for witch flounder
(Glyptocephalus cynoglossus) for the period 2002-2018. Detailed indices are presented from 2013.
Yellowtail flounder indices do not show a clear trend. Biomass increased from 1997 to 1999 has maintained
almost constant values until 2013 and then decreased in 2014-2018. Redfish indices oscillate greatly over time,
probably because the gear does not sample adequately aggregating pelagic species. There was a sharp increase
in 2009 and since then until 2015, biomass fluctuated maintaining higher values than before 2009. In 2016
biomass dropped and increase again in 2017-2018 to the 2012 level. The 3N division comprises around the
90% of the total biomass in the last years. Good year classes have not been registered recently. Length
distribution in thousands (abundance) by Division and year since 2002 is presented. Following the trend of the
biomass, most of the abundance corresponds to Division 3N. Witch flounder is very scarce and its indices
fluctuated throughout the series reaching the minimum value in 2014 and 2018, with an increasing trend in
the middle time. Recruitment was quite good at the beginning of the series but poor in recent years
Biomass and length distribution for roughhead grenadier, thorny skate, white hake, squid and capelin from the surveys conducted by Spain in NAFO 3NO
Data for roughhead grenadier (Macrourus berglax), thorny skate (Amblyraja radiata) and white hake
(Urophycis tenuis) from the Spanish Spring survey are presented. Abundance and biomass were estimated for
roughhead grenadier and thorny skate for the period 1997-2019 and for white hake for the period 2001-2019.
The length distribution is presented as numbers per haul stratified mean catches for the last five years (2015-
2019). The roughhead grenadier indices showed no discernible trend during the whole series, reaching a
maximum in 2004 and a minimum in 2019. In 2017 and 2018, a quite good presence of small and medium
lengths (1.5-19.5 cm) can be seen. Thorny skate indices follow a large oscillating trend, dropping in 2007 and
has been since then more or less stables at a low level, reaching the minimum of the series by far in 2019. In
2017 there is a discrete presence of length between 12 and 18 cm. White hake indices were highest in 2001
and then showed an overall decreasing trend until 2008 with low values, generally increasing since then with
some fluctuations. The 2019 biomass is the second lowest of the period studied. Small recruitment events were
detected in 2004, 2012 and 2013, with individuals between 16-26 cm. In 2017 the highest numbers are at small
lengths, between 20 and 24 cm, being around 34 cm in 2018. In 2019, the mode is around 8 cm. The estimated
biomass of squid is inconstant and very low in general. There were no catches of squid during the 2002 and
2013-2015 surveys. In 2018 and 2019, a step increase in biomass was observed during the survey, being 5.5
and 7 times, respectively, the third value of the series in 2011. Length samples were taken in 2011, 2017 and
2019. The lengths range between 3.5 and 19 cm. Capelin biomass reached a maximum in 2012, decreasing
sharply since then until 2017. In 2018 the index increased to a level similar to that in the early 2000s,
decreasing slightly in 201
Yellowtail flounder, redfish (Sebastes spp.) and witch flounder indices from the Spanish Survey conducted in Divisions 3NO of the NAFO Regulatory Area
Since 1995, Spain carries out a spring stratified random bottom trawl survey in Div. 3NO of the NAFO
Regulatory Area. Total mean catches, biomass and mean numbers for yellowtail flounder (Limanda ferruginea)
are presented for the period 1995-2019, for redfish (Sebastes spp.) for the period 1997-2019 and for witch
flounder (Glyptocephalus cynoglossus) for the period 2002-2019. Detailed indices are presented from 2015.
Yellowtail flounder indices do not show a clear trend between 1999 and 2016. The 2017-2019 values were
lower than the 1998 one. There has not been good recruitment in recent years. Redfish indices oscillate greatly
over time, probably because the gear does not sample adequately aggregating pelagic species. There was a
sharp increase in 2009 and since then until 2015, biomass fluctuated maintaining higher values than before
2009. In 2016 biomass dropped and increase again in 2017-2019 to or below the 2012 level. The 3N division
comprises around the 90% of the total biomass in the last years. Good year classes have not been registered
recently. Abundance by Division shows since 2002 shows the same trend of the biomass; most of the abundance
corresponds to Division 3N. Witch flounder is very scarce and its indices fluctuated throughout the series
reaching a low level in 2014 and 2018, with an increasing trend in the middle time. The 2019 value is the lowest
of the series, being less than 50% of 2014 value. Recruitment was quite good at the beginning of the series but
poor in recent years
Remodeling Capacity of Femoral Bone Defect by POP-CHA Bone Substitute: a Study in Rats\u27 Osteoclast (First Series of POP-based Bone Graft Improvement)
Reconstruction of large bone defects caused by trauma, excision of tumors, and congenital malformations can be very difficult to perform. Bone engineering offers an option to improve bone reconstruction procedures. This interdisciplinary field applies the principles of biology and engineering to the development of functional substitutes for damaged bone. Our research aimed to find the ideal scaffold for bone regeneration, focusing on Calcium and Phosphate combination. In this study, Plaster of Paris (POP) was combined with CHA and implanted in femoral condyles of rats. According to the experimental result, it can be concluded that there was no significant difference in response to the implantation of POP and POP-CHA in Sprague Dawley rat femur condyle (p<0.05). It can be stated that both POP-CHA and POP shows similar trait in bone healing
Inflation without inflatons
(abridged)We present a model which predicts inflation without the presence of
inflaton fields, based on the \epsilon R^2 and Starobinsky models. It links the
above models to the observable universe, in particular, to the ratio r of
tensor to scalar fluctuations. In our model, we assume the existence of
particles with the mass M that have a long decay time. These particles which
were gravitationally produced \sim 60e-folds before the end of inflation
produced the nearly scale invariant scalar density fluctuations which are
observed. Gravitational waves (tensor fluctuations) were also produced at this
epoch. The ratio of tensor to scalar fluctuations r (which are to be measured
in the near future to good accuracy) determines M, which together with H_0,
determine the time at the end of inflation, t_end. At t_end, the Hubble
parameter begins to oscillate rapidly, gravitationally producing the bulk of
the M particles, which we identify with the matter content of the universe
today. The time required for the universe to dissipate its vacuum energy into M
particles is found to be t_dis \simeq 6M_Pl^2/M^3. We assume that the time
t_RH, (called the reheating time) needed for the M particles to decay into
relativistic particles, is very much greater than that necessary to create the
M particles, t_dis. From the ratio f\equiv t_dis/t_RH and g_\ast (the total
number of degrees of freedom of the relativistic particles) we can, then,
evaluate the maximum temperature of the universe, T_max, and the reheat
temperature, T_RH, at t_RH. Our model, thus, predicts M, t_dis, t_end, T_max,
T_RH, t_max, and t_RH as a function of r, f, and g_\ast (and to a weaker extent
the particle content of the vacuum near the Planck epoch).Comment: 11 pages, 2 figures. Revised version, accepted for publication in
Phys. Rev.
Evaluation of the nutritional aspects and cholesterol oxidation products of pork liver and fish patés
A comparative study between traditional patés elaborated with pork liver and fish patés (salmon, anchovy and cod) was carried out. The nutritional value and their security related to cholesterol oxidation products (COP) content were evaluated. Salmon paté showed similar fat content (24-28%) and energetic value (300Kcal/100g) to pork liver patés, whereas patés made with anchovy and cod showed less fat (13-16%) and calories (200-236 Kcal/100g).
PUFA/SFA ratios were much higher in all fish patés (1.55-4.95) than in liver pork patés (0.36-0.44). No great differences were found in ω-6/ω-3 ratio between salmon and pork liver patés (11.34-18.4), being even much higher this ratio in anchovy (32.32) and cod patés (62.77). EPA and DHA supply was around 0.63 for salmon, 0.21 for anchovy and 0.07 for cod patés. Cholesterol amounts were lower in fish patés (31-37mg/100g) than in pork liver patés (77-102mg/100g). Total COP ranged 0.38-2.83ppm, without clear differences between pork liver and fish patés
Topological transition in a two-dimensional model of liquid crystal
Simulations of nematic-isotropic transition of liquid crystals in two
dimensions are performed using an O(2) vector model characterised by non linear
nearest neighbour spin interaction governed by the fourth Legendre polynomial
. The system is studied through standard Finite-Size Scaling and
conformal rescaling of density profiles of correlation functions. A topological
transition between a paramagnetic phase at high temperature and a critical
phase at low temperature is observed. The low temperature limit is discussed in
the spin wave approximation and confirms the numerical results
Effective growth of matter density fluctuations in the running LCDM and LXCDM models
We investigate the matter density fluctuations \delta\rho/\rho for two dark
energy (DE) models in the literature in which the cosmological term \Lambda is
a running parameter. In the first model, the running LCDM model, matter and DE
exchange energy, whereas in the second model, the LXCDM model, the total DE and
matter components are conserved separately. The LXCDM model was proposed as an
interesting solution to the cosmic coincidence problem. It includes an extra
dynamical component, the "cosmon" X, which interacts with the running \Lambda,
but not with matter. In our analysis we make use of the current value of the
linear bias parameter, b^2(0)= P_{GG}/P_{MM}, where P_{MM} ~
(\delta\rho/\rho)^2 is the present matter power spectrum and P_{GG} is the
galaxy fluctuation power spectrum. The former can be computed within a given
model, and the latter is found from the observed LSS data (at small z) obtained
by the 2dF galaxy redshift survey. It is found that b^2(0)=1 within a 10%
accuracy for the standard LCDM model. Adopting this limit for any DE model and
using a method based on the effective equation of state for the DE, we can set
a limit on the growth of matter density perturbations for the running LCDM
model, the solution of which is known. This provides a good test of the
procedure, which we then apply to the LXCDM model in order to determine the
physical region of parameter space, compatible with the LSS data. In this
region, the LXCDM model is consistent with known observations and provides at
the same time a viable solution to the cosmic coincidence problem.Comment: LaTeX, 38 pages, 8 figures. Version accepted in JCA
Oxysterols: A world to explore
Oxysterols (oxidized derivatives of cholesterol and phytosterols) can be generated in the human organism through different oxidation processes, some requiring enzymes. Furthermore, oxysterols are also present in food due to lipid oxidation reactions caused by heating treatments, contact with oxygen, exposure to sunlight, etc., and they could be absorbed from the diet, at different rates depending on their side chain length. In the organism, oxysterols can follow different routes: secreted into the intestinal lumen, esterified and distributed by lipoproteins to different tissues or degraded, mainly in the liver. Cholesterol oxidation products (COPs) have shown cytotoxicity, apoptotic and pro-inflammatory effects and they have also been linked with chronic diseases including atherosclerotic and neurodegenerative processess. In the case of phytosterol oxidation products (POPs), more research is needed on toxic effects. Nevertheless, current knowledge suggests they may also cause cytotoxic and pro-apoptotic effects, although at higher concentrations than COPs. Recently, new beneficial biological activities of oxysterols are being investigated. Whereas COPs are associated with cholesterol homeostasis mediated by different mechanisms, the implication of POPs is not clear yet. Available literature on sources of oxysterols in the organism, metabolism, toxicity and potential beneficial effects of these compounds are reviewed in this paper
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