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991.
J. C. J. Da Silva S. Cadore J. A. Nobrega N. Baccan 《Food Additives & Contaminants》2007,24(2):130-139
Samples of commercial wine vinegar were introduced in an axially viewed inductively coupled plasma optical emission spectrometry instrument (AX-ICP OES) equipped with different sample introduction systems: a cross-flow nebulizer combined with a double-path spray chamber (CF-DP) and cone spray associated with a cyclone spray chamber (CS-CC). Samples of white and red wine vinegar were diluted with water before analysis. Higher magnesium Mg II/Mg I ratios (11 and 10 for CS-CC and CF-DP, respectively) were obtained using a nebulization gas flow rate of 0.6 l min-1 and an applied power of 1.3 kW. The background equivalent concentrations (BEC) and signal-to-background ratio (SBR) of analytes were improved using scandium (Sc) as the internal standard. The limits of detection (LOD) and limits of quantification (LOQ) for mineral constituents were similar for both introduction systems. Best recoveries values were obtained using a plasma under robust conditions, CS-CC system and Sc as the internal standard. The concentration determined in 13 commercial samples of wine vinegars varied between 0.2 and 3.0, between 0.02 and 0.4, between 8.5 and 100.0, between 0.01 and 0.05, between 27.0 and 540.0, between 4.0 and 79.0, between 0.4 and 10.0, and between 0.01 and 2.0 for aluminium (Al), barium (Ba), calcium (Ca), copper (Cu), potassium (K), magnesium (Mg), manganese (Mn), and zinc (Zn), respectively. 相似文献
992.
C André MM Da Silva EJ Da Silva MA Souza ES Bastos SA Novis 《Canadian Metallurgical Quarterly》1997,55(2):231-236
OBJECTIVE: It has been shown recently that 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) is expressed as at least 2 isozymes. In the liver, 11 beta-HSD1 converts cortisone to cortisol; in the kidney, 11 beta-HSD2 converts cortisol to cortisone. Conventional assessment of 11 beta-HSD activity in vivo has relied on gas chromatographic measurement of the ratios of conjugated cortisol and cortisone metabolites. However, these do not permit distinction between the tissue-specific activities of the enzymes and do not reflect all forms of 11 beta-HSD deficiency. In this report, we have assessed the usefulness of measuring unconjugated cortisol metabolites and free cortisol and cortisone in urine as indices of renal 11 beta-HSD activity in man. DESIGN: Six healthy male subjects established in sodium balance were given either glycyrrhetinic acid (170 mg t.d.s., to inhibit 11 beta-HSD2), carbenoxolone (100 mg t.d.s., to inhibit both 11 beta-HSD1 and 11 beta- HSD2) or both inhibitors in combination. MEASUREMENTS: Urinary electrolytes were measured and the concentrations of total and unconjugated urinary cortisol and its metabolites were determined by gas chromatography mass spectrometry. RESULTS: Glycyrrhetinic acid and carbenoxolone inhibited renal 11 beta-HSD2 to a similar degree, as judged by similar sodium retention. As previously reported, conventional measurement of ratios of total cortisol to cortisone metabolites were influenced to a greater extent by glycyrrhetinic acid (100-200% increase in ratio from baseline) than by carbenoxolone (< 30% increase). However, the effect of carbenoxolone was readily detected by measurement of urinary unconjugated cortisol/cortisone (130-480% increase of ratio from baseline) and also by measurement of ratios of unconjugated cortisol metabolites (60-130% increase). CONCLUSIONS: Measurement of free cortisol and cortisone in urine provides the most sensitive index of renal 11 beta-HSD activity. Measurement of total and conjugated urinary steroids is insensitive in circumstances where 11 beta-HSD activity in liver or elsewhere may be abnormal. 相似文献
993.
H Silva S Jerez A Paredes J Salvo P Rentería A Ramírez C Montes 《Canadian Metallurgical Quarterly》1997,25(6):391-395
The debate about mercury and dental amalgam has been one of the longest running in dentistry, and shows no signs of abating. This study aimed to investigate perceptions about mercury in dental fillings among a representative sample of the Australian public. A random sub-sample of participants in a national dental telephone interview survey completed a follow-up postal questionnaire which included four items on dental mercury. The postal survey response rate was 85.2%. Concern about mercury in dental fillings was expressed by 37.5%, while 16.2% reported having requested fillings that do not contain mercury. Avoidance of dental care because of concern about mercury in fillings was reported by 5.8%, but only 4.7% reported having had fillings replaced because they contained mercury. The data indicate that there is a substantial degree of concern about mercury and dental amalgam among the Australian public, but that the dental behavioural and treatment-pattern consequences of that concern are infrequent. 相似文献
994.
Edson da Costa Bortoni Roberto Alves de Almeida Augusto Nelson Carvalho Viana 《Energy Efficiency》2008,1(3):167-173
This paper presents an optimization framework based on dynamic programming mathematic tool suitable to be implemented in programmable
logic controllers to improve the automated control of parallel pumping loops aiming at energy conservation. The paper also
contributes with simple methods to derive system curve and pumping head-flow speed-dependent characteristic from ordinary
field measurements. 相似文献
995.
996.
997.
S Cascinu R Labianca P Alessandroni M Marcellini RR Silva G Pancera E Testa G Martignoni S Barni L Frontini A Zaniboni G Luporini R Cellerino G Catalano 《Canadian Metallurgical Quarterly》1997,15(11):3313-3319
PURPOSE: A multiinstitutional trial was performed to confirm the clinical activity, in terms of response rate and toxicity (primary objectives) and duration of responses and survival (secondary objectives), of an intensive weekly regimen in advanced gastric cancer. PATIENTS AND METHODS: Patients with measurable unresectable and/or metastatic gastric carcinoma received 1-day per week administration of cisplatin (CDDP) 40 mg/m2, fluorouracil (5FU) 500 mg/m2, epi-doxorubicin (epi-ADR) 35 mg/m2, 6S-stereoisomer of leucovorin 250 mg/m2, and glutathione 1.5 g/m2. On the other days, filgrastim was administered by subcutaneous injection at a dose of 5 mg/kg. One cycle of therapy consisted of eight 1-week treatments. Patients who showed a response or stable disease received a further 6 weeks of therapy. RESULTS: Of 105 enrolled patients, 11 had locally advanced unresectable disease only; 33 had primary nonresected and metastatic disease; 48 had metastatic disease and primary tumor resected; 10 had locoregional recurrence and metastatic disease; and three had locoregional recurrence only. After one cycle, 18 complete responses (CRs) and 47 partial responses (PRs) were achieved, for an overall response rate of 62% (95% confidence interval [CI], 53% to 71%). Twenty patients had stable disease and 20 progressed on therapy. The median survival duration of all 105 patients was 11 months, with 1- and 2-year survival rates of 42% and 5%, respectively. World Health Organization (WHO) grade III to IV toxicity, in terms of anemia, neutropenia, thrombocytopenia, and mucositis, was experienced by 40 patients (38%). There were no treatment-related deaths. CONCLUSION: These data support the results of the pilot study and confirmed the high activity of the regimen, with acceptable toxicity. This schedule deserves evaluation in the adjuvant setting. 相似文献
998.
999.
António César Silva Ferreira Judith Monteiro Carla Oliveira Paula Guedes de Pinho 《Food chemistry》2008
The carotenoids degradation and the formation of volatiles were examined by simulating Port wine aging. A two year old red Port wine was saturated with oxygen, supplemented with lutein and β-carotene and kept at 60 °C during 87 h. A similar study was performed in a model wine solution. Results showed that the percentage decrease in lutein levels was, respectively, 79% and 95%, in the wine model solution and in the Port wine, and 55% and 10% for β-carotene, indicating that lutein was more sensitive to degradation than β-carotene. Two other unknown degradation carotenoid compounds were identified by HPLC/DAD (reverse phase λmax: 422; 445; 475 and 422; 445; 472) in the lutein supplemented wine. Levels of β-ionone and β-cyclocitral increased (2.5 times) in both, wine and wine model solution, supplemented with β-carotene. Along with these compounds, the same behaviour was observed in β-damascenone in the supplemented lutein wine and wine model solution. New insights were provided into the understanding of aroma modifications occurring during Port wine aging. The relationship between carotenoid molecules (β-carotene and lutein) and some volatiles has also been provided. 相似文献
1000.
U. Asanka D. Jayasinghe Upali S. Amarasinghe Sena S. De Silva 《Lakes & Reservoirs: Research and Management》2005,10(3):157-166
This study was carried out to investigate the possibility of using the limnological characteristics of non‐perennial reservoirs in Sri Lanka for the future management of culture‐based fisheries. Forty‐five reservoirs were randomly selected to study their limnology, out of which 32 were stocked with fish fingerlings of Chinese and Indian carps, tilapia and freshwater prawn at stocking densities ranging from 218–4372 fingerlings ha?1. Of these, 23 reservoirs were harvested at the end of the culture period (6–10 months). Thirteen limnological parameters were measured during the water retention period of each of the 45 reservoirs between November 2001 and January 2004. The mean values of the limnological parameters were used to ordinate the reservoirs through principal component analysis. Ordination showed a productivity gradient among reservoirs where Secchi disc depth, total phosphorus, chlorophyll‐a, inorganic turbidity and organic turbidity were identified as key factors. The total fish yield of culture‐based fisheries was positively correlated to the scores of the first principal component axis. This study reveals that it is possible to classify non‐perennial reservoirs in Sri Lanka based on the above limnological parameters in order to develop culture‐based fisheries and that they could be applicable in comparable water bodies elsewhere in the tropics. 相似文献