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171.
Rafael Alique Pilar Luna Teresa Hernández M. Angel Martínez 《European Food Research and Technology》2009,229(4):661-669
Atomised hot water vapour at between 46 and 54 °C for 60 min was tested as a method of delaying ripening and extending shelf
life in cv “Fino de Jete” cherimoya fruit (Annona cherimola Mill.). Heat treatment at 46 °C stimulated the respiration rate and starch degradation, induced ethylene production, increased
the accumulation of soluble sugars and α-amylase activity, and moved the onset of ethylene production (OEP) forward. Treatment
at 50 °C, and especially at 52 °C, delayed the climacteric peak and the OEP, decreased sugar and organic acid accumulation,
and reduced α-amylase and invertase activity. The results obtained indicate that temperatures higher than 48 °C slowed physiological
processes and carbohydrate metabolism and extend the shelf life of the cherimoya fruits, while temperatures higher than 52 °C
blocked ripening irreversibly. 相似文献
172.
Raquel Ibáñez Marco Peluso Armelle Munnia Sara Piro Carlos A. González Pilar Amiano M. J. Tormo Eva Ardanaz Aurelio Barricarte Antonio Berenguer M. Dolores Chirlaque Miren Dorronsoro Paula Jakszyn Nerea Larrañaga Carmen Martínez Carmen Navarro J. Ramón Quirós M. José Sánchez Antonio Agudo 《European Food Research and Technology》2009,229(4):549-559
The aim of this study was to assess the relationship between bulky DNA adducts in white blood cells (WBC) and lifestyle factors
in a sample from the Spanish cohort of the European Prospective Investigation into Cancer and Nutrition (EPIC). 296 subjects
aged between 35 and 64 years, from five regions, were included. Food intake was estimated with a computerized version of dietary
history questionnaire. Daily intake of polycyclic aromatic hydrocarbons (PAH) was estimated using a database with information
on food content of potential carcinogens. Data on lifestyle and health factors were collected and DNA adducts measured using
the nuclease P1 32P-postlabelling technique. Geometric means of adducts were similar for men and women (4.11/109 and 3.94/109 nucleotides, respectively). Highest levels of adduct were observed in non-smokers and non-occupationally exposed. Meat intake,
oils and fats were associated with higher levels of adducts, but all non-statistically significant. Higher intakes of calcium,
sodium and phosphorus were associated with lower adducts levels. Summarising, our study shows that bulky adducts measured
by 32P-postlabelling in DNA from WBC do not correlate with the usual diet of healthy Spanish adults. Although it has been proposed
that diet be the main source of PAH in nonsmokers without occupational exposure, DNA adducts do not seem to be suitable biomarkers
of dietary PAH in general population. 相似文献
173.
Lilian Abugoch Eduardo Castro Cristian Tapia María Cristina Añón Pilar Gajardo & Andrea Villarroel 《International Journal of Food Science & Technology》2009,44(10):2013-2020
The amino acid composition and the physicochemical and functional properties of quinoa flour proteins (QFP) were evaluated during storage (at 20, 30 and 40 °C). Quinoa flour showed a protein content of 14.2 ± 0.1 g 100 g−1 and high levels of essential amino acids as lysine. SDS–PAGE of the QFP presented ten major band, and native-PAGE of the QFP showed similar banding; there was a little variation due to time-temperature. TCA-protein solubility variation (%) was small and the values of water activity were low, a non-significant endogenous hydrolysis was observed. Differential scanning calorimetry flour analysis allowed determining two endotherms, starch and protein. Important structural changes of protein soluble fractions were not detected by UV and fluorescence spectroscopy due to temperature and time of storage. It was found during storage time loss of protein solubility and water absorption. These changes could be to influence in the manufacture of quinoa flour based products. For avoid changes in these functional properties (solubility and water holding capacity), quinoa flour can be stored at ambient temperature (between 20 and 30 °C) and packed in double kraft paper bags (2 months). 相似文献
174.
A. Vioque M. A. Albi Pilar Ma del Villagran 《Journal of the American Oil Chemists' Society》1964,41(12):785-787
The effects of different solvents, degree of dilution, type of resin, and temperature were studied to determine the optimum
conditions for “demetalization” of soybean oils with cation exchange resins. Prooxidant metals in crude soybean oils in acetone
orn-hexane solutions can be effectively removed when passed through columns of a strong cation exchange resin.
Supported by Grant No. FG-Sp-103-60 under Public Law 480. Agricultural Util. Res. Program. USDA. 相似文献
175.
1. Whole-cell and perforated-patch tight-seal recording techniques were used to characterize the voltage-dependent membrane conductances of the Y-79 cells, a human retinoblastoma line composed of pluripotential retinal precursor cells. 2. Membrane resistance and capacitance were measured under current clamp, yielding approximate average values of 1.8 G omega and 26 pF, respectively. The cells are electrically excitable, and depolarization above -20 mV triggers slow action potentials. 3. Step depolarization of the membrane under voltage clamp elicits a high-threshold transient inward current, followed by a sustained, larger outward current. The outward current is carried by potassium ions, as determined by its susceptibility to blockage by K-channel antagonists [tetraethylammonium (TEA), Cs, and 4-aminopyridine (4-AP)] and insensitivity to reduction of external chloride concentration. 4. The isolated inward current displayed some unusual properties: its amplitude is directly related to extracellular calcium concentration, and replacement of calcium by magnesium completely abolishes it. However, none of the calcium channel antagonists tested (cadmium, nickel, nifedipine, and amiloride) exerted a substantial blockage. In addition, removal of external sodium or superfusion with tetrodotoxin significantly reduce the size of this current. 5. A single voltage-dependent conductance appears to underlie the inward current, because a variety of manipulations, such as changes in the holding potential, in the extracellular concentration of calcium or sodium, or superfusion with tetrodotoxin, failed to reveal the presence of kinetically distinct components. 6. The results suggest that a single voltage-dependent conductance mechanism underlies the depolarization-activated inward current in Y-79 cells. This channel appears to be primarily permeable to calcium, but with a significant contribution by sodium ions. Its functioning appears to be modulated by extracellular calcium. 相似文献
176.
The timing, magnitude, and orientation of the escape response from a model predator were examined. A high proportion of the responses were touch-evoked; the lizards responded only immediately after the model contacted them. When the model approached at a higher speed, lizards (Psammodromus algirus) initiated the escape sooner, ran at higher speeds, and escaped to longer distances, but their reactive distances did not vary. Model speed did not affect the escape duration or the directness of the response. Escape trajectories were not random. Responses away from the model occurred more often than responses toward the model, but initial orientation affected the direction of escape trajectories. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
177.
J Gómez V Ba?os J Ruiz F Herrero M Pérez L Pretel M Canteras M Valdés 《Canadian Metallurgical Quarterly》1993,71(8):595-599
A prospective study was designed to investigate anaerobic bacteremias and evaluate their incidence and significance in a general hospital. One or more blood cultures positive for anaerobic microorganisms were analyzed from each of a total of 61 patients hospitalized between January 1988 and April 1992, in accordance with an established protocol. The clinical repercussions of bacteremia were also analyzed. Two percent of blood cultures were positive for anaerobes, with an incidence of 0.6 cases per 1000 hospitalized patients. The most frequently isolated anaerobes were Bacteroides fragilis and Clostridium perfringens. Intraabdominal disease was the route of entry in 50% of the patients. A death rate of 37.3% was mostly attributed to B. fragilis. Hospitalization in the surgical department, nosocomial acquisition, previous surgery, critical initial clinical status and the presence of complications were significantly associated with increased death rates. No significant differences were found in the clinical course between patients whose antibiotic treatment was judged adequate and those for whom it was considered inadequate. The frequency and incidence of anaerobic bacteremia was low in our hospital. The well-known clinical and epidemiological characteristics of these infections facilitates their prompt diagnosis and empirical treatment with antibiotics of proven effectiveness against anaerobes. 相似文献
178.
Isabel M Martín Del Molino Brbara Rojo Rafael Martinez-Carrasco Pilar Prez 《Journal of the science of food and agriculture》1988,42(1):29-37
The changes in the composition of free and total amino acids in wheat grain during development are described: the experiment was performed in a growth chamber with three varieties of winter wheat (Triticum aestivum L.): Splendeur, Hobbit and Maris Huntsman. The changes in the total composition of amino acids of the grain as development progressed were consistent with an increase in the proportion of storage proteins. At 15 days after anthesis, the relative amount of glycine increased, suggesting that at this moment the proportion of gliadins was relatively low. The relative amount of arginine increased in mature grain, showing that at times close to maturity the relative proportion of synthesis of a protein fraction rich in this amino acid increased. Free glutamate, proline and arginine decreased at 15 days to a greater extent than the other amino acids and was present in low relative amounts during the period of maximum protein synthesis in the grain; these three amino acids could be the most limiting for protein synthesis in grain. In the free fraction the following showed a similar pattern of change during grain development: aspartate, arginine and histidine on the one hand, and on the other alanine, valine, leucine, isoleucine, threonine, phenylalanine and tyrosine; moreover both groups were inversely correlated. Glycine and lysine were directly related to each other and inversely to glutamate. 相似文献
179.
M García González AL Sanromán C Herrero L Ledo A Moreno C González V Moreira 《Canadian Metallurgical Quarterly》1994,194(3):170-172
Three new cases of cholestatic hepatitis caused by droxicam are described, along with a revision of the other eight cases published to date. Itching, asthenia, and jaundice were the most common symptoms. Average age was 62.8 years (range: 45-82 years), and the median time of exposition was 22.7 days (range: 5-50 days). Biochemistry of the liver showed primarily cholestasis and in 4/11 cases hypereosinophilia. Two patients presented elevated levels of cholesterol and triglycerides which disappeared within the month. Clinical manifestations persisted in one patient for eight weeks after the cessation of treatment. The three patients presented in the present series presented alteration in the biochemistry of the liver two months after initiation. Liver biopsy in three patients showed centrozonal cholestasis associated with portal inflammatory activity and presence of granulomas consistent with toxic hepatitis. 相似文献
180.
I Herrero MT Miras-Portugal J Sánchez-Prieto 《Canadian Metallurgical Quarterly》1998,273(4):1951-1958
We have investigated the role of metabotropic glutamate receptors linked to phosphoinositide hydrolysis in the control of glutamate release in cerebrocortical nerve terminals. The activation of these receptors with the agonist 3,5-dihydroxyphenylglycine enhanced intra-synaptosomal diacylglycerol and facilitated both the depolarization-induced increase in the cytosolic free Ca2+ concentration and the release of glutamate. However, 5 min after receptor activation, a second stimulation of the pathway with the agonist failed to produce diacylglycerol and to facilitate glutamate release. Interestingly, during the period in which the diacylglycerol response was desensitized, a strong agonist-induced inhibition of Ca2+ entry and glutamate release was observed. This change in the presynaptic effects of 3,5-dihydroxyphenylglycine is reversible since 30 min after the first stimulation, the agonist-induced inhibition of release disappeared, whereas both the production of diacylglycerol and the facilitation of glutamate release were recovered. The tonic elevation of the extracellular glutamate concentration from basal levels (0.8 microM) up to 5 microM also produced the switch from facilitation to inhibition in the receptor response. The existence of this activity-dependent switch in the presynaptic control of glutamate release suggests that release facilitation is limited to conditions under which an appropriate clearance of synaptic glutamate exists, probably to prevent the neurotoxic accumulation of glutamate in the synapse. 相似文献