312 research outputs found

    A new approach to crystal growth of Hg1−xCdxTe by the travelling heater method (THM)

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    Crystal growth by the travelling heater method (THM) is reported using a source material preparation process that is different from all methods used before. Non-stoichiometric (Hg, Cd)Te melts were homogenized and quenched to prevent macroscopic segregation effects. Inclusions of excess Te were removed during a first THM pass, resulting in stoichiometric solid alloys with a shift of the mole fraction towards higher CdTe contents. The amount of the shift, dependent on the Te excess and on the equilibrium temperature of the first THM run, was calculated and taken into account in the preparation of x=0.22 and x=0.30 Hg1-xCdxTe single crystals. Source material ingots, as well as THM single crystals, were characterized with special emphasis of the compositional homogeneity. Radial as well as axial homogeneity are comparable with the best results on THM crystals reported so far. The described method can be used in growing all materials for which THM is possible. However, quantitative calculation requires the exact knowledge of the particular ternary phase diagram

    Histamine food poisonings: A systematic review and meta-analysis

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    ABSTRACTObjective: The aim of this study was to assess the mean of histamine concentration in food poisoning.Design: Systematic review and meta-analysis of reports published between 1959 and 2013.Study selection: Main criteria for inclusion of studies were: all report types that present outbreaks of "histamine poisoning' or "scombroid syndrome" from food, including histamine content and type of food. Health status of people involved must be nonpathological.Results: Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with confidence interval for the meta-mean of 422.62–2900.78 mg/kg; heterogeneity index (I2) was 100% (P < 0.0001); prediction interval was 24.12–50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication,..

    Increased sympathetic activity in normotensive offspring of malignant hypertensive parents compared to offspring of normotensive parents

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    Malignant hypertension seems to be the consequence of very high blood pressure. Furthermore, an increase in sympathetic and renin-angiotensin system activity is considered to be the main mechanisms producing malignant hypertension. In the present study, 10 offspring of malignant hypertensive (OMH) parents (age 28 ± 5 years, 7 males, 3 females, 2 white and 8 non-white) and 10 offspring of normotensive (ONT) parents (age 28 ± 6 years, 2 males, 8 females, 3 white and 7 non-white) were evaluated. The OMH group had significantly higher (P < 0.05) casual blood pressure (125 ± 10/81 ± 5 mmHg) compared with ONT (99 ± 13/67 ± 5 mmHg). The increase in blood pressure was greater in OMH (&#916; SBP = 17 ± 2 vs &#916; SBP = 9 ± 1 mmHg in ONT) during cold pressor testing, but they had a lower increase in heart rate (&#916; HR = 13 ± 2 vs &#916; HR = 20 ± 3 bpm in ONT) during isometric exercise (handgrip test). Sympathetic activity, measured by microneurography, was significantly higher (P < 0.05) before exercise in OMH (17 ± 6 vs 11 ± 4 burst/min in ONT) and exhibited a greater increase (&#916; = 18 ± 10 vs &#916; = 8 ± 3 burst/min in ONT) during isometric exercise. This study showed increased sympathetic activity in OMH before exercise and a greater response during isometric exercise, suggesting an autonomic abnormality before exercise and a greater sympathetic response to physical stress in OMH compared to ONT

    Histamine food poisoning : a systematic review and meta anlysis

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    Objective: Aim of this study was to assess the mean of histamine concentration in food poisoning. Design: Systematic review and meta-analysis of reports published between 1959-2013. Study selection: main criteria for inclusion of studies were: all report types that present outbreaks of \u201chistamine poisoning\u201d or \u201cscombroid syndrome\u201d from food, including histamine content and type of food. Health status of people involved must be non pathological. Results: Fifty-five (55) reports were included, these studies reported 103 incidents. All pooled analyses were based on random effect model; histamine mean concentration in poisoning samples was 1107.21 mg/kg with a prediction 95% interval of 422.62 - 2900.78 mg/kg; heterogeneity index (I2) was 100 % (P<0.0001); prediction interval was 24.12 \u2013 50822.78 mg/kg. Fish involved in histamine poisoning was mainly tuna or Istiophoridae species. No clues of association between concomitant conditions (female sex, alcohol consumption, previous medication and consumption of histamine releasing food) and histamine poisoning, were highlighted. Conclusions: This is the first systematic review and meta-analysis that analyzes all the available data on histamine poisoning outbreaks evaluating the histamine concentration in food involved. Histamine mean concentration in poisoning samples was fairly high. Our study suffers from some limitations, which are intrinsic of the studies included, for instance the lack of a complete anamnesis of each poisoning episode

    Evaluation of the in vitro antimicrobial activity of mixtures of Lactobacillus sakei and Lactobacillus curvatus isolated from argentine meat and their effect on vacuum-packaged beef

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    A L. sakei and a L. curvatus-based mixtures exerted an antagonistic activity in vitro against 12 different spoilage and pathogenic bacteria. No activity was exerted by the cell-free supernatants. The addition of the two mixtures to sliced vacuum-packaged beef showed a better capability of L. sakei to adapt to meat substrate. After 60 days, Total Viable Count (5.8 vs 7.4 Log CFU/g), Gram-negative bacteria (2.5 vs 6.4 Log CFU/g) and Enterobacteriaceae (2.3 vs 4.4 Log CFU/g) were significantly lower in L. sakei-inoculated samples if compared with control ones; TVC and Enterobacteriaceae were also significantly lower in L. curvatus-inoculated samples than control ones. The addition of mixtures gave no significant effects on meat pH and colour. The use of high dosage of viable cells could be suggestible in order to exert an early conditioning of meat environment

    Critical analysis of autoregressive and fast Fourier transform markers of cardiovascular variability in rats and humans

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    The autonomic nervous system plays an important role in physiological and pathological conditions, and has been extensively evaluated by parametric and non-parametric spectral analysis. To compare the results obtained with fast Fourier transform (FFT) and the autoregressive (AR) method, we performed a comprehensive comparative study using data from humans and rats during pharmacological blockade (in rats), a postural test (in humans), and in the hypertensive state (in both humans and rats). Although postural hypotension in humans induced an increase in normalized low-frequency (LFnu) of systolic blood pressure, the increase in the ratio was detected only by AR. In rats, AR and FFT analysis did not agree for LFnu and high frequency (HFnu) under basal conditions and after vagal blockade. The increase in the LF/HF ratio of the pulse interval, induced by methylatropine, was detected only by FFT. In hypertensive patients, changes in LF and HF for systolic blood pressure were observed only by AR; FFT was able to detect the reduction in both blood pressure variance and total power. In hypertensive rats, AR presented different values of variance and total power for systolic blood pressure. Moreover, AR and FFT presented discordant results for LF, LFnu, HF, LF/HF ratio, and total power for pulse interval. We provide evidence for disagreement in 23% of the indices of blood pressure and heart rate variability in humans and 67% discordance in rats when these variables are evaluated by AR and FFT under physiological and pathological conditions. The overall disagreement between AR and FFT in this study was 43%.FINEPFAPESPZerbini Foundatio

    The PlantLIBRA consumer survey: Findings on the use of plant food supplements in Italy

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    Background Food supplements, and in particular those containing botanicals (plant food supplements, PFS), have in recent decades been of great interest both to consumers and to food/pharmaceutical industries. Objectives The aim of this paper is to examine replies by Italian consumers to the PlantLIBRA consumers' survey in order to: 1) assess the behaviour of an Italian population with respect to the use of PFS, and to compare it with that of other 5 countries involved in the whole survey; 2) identify different habits in the 4 Italian cities selected according to their geographical distribution; 3) collect independent information on the actual intake of PFS and consumers' behaviour. Subjects/setting 397 Italian consumers enrolled, 187 males (49.5%) and 191 female (50.5%). The distribution of subjects among the 4 cities included was: Milan 99; Venice 90; Rome 96 and Catania 96. Results The interest in PFS in Italy is high, the prevalence of "regular" consumers being 22.7%. Some differences were observed between the 4 cities involved: the pattern of use during the year was specific to each city; consumers in Milan reported reasons to use PFS significantly different from those in the whole Italian sample and did not indicate supermarkets as an important place of purchase; respondents from Rome and Catania more frequently used family doctors and pharmacists as a source of recommendation. Some significant difference among cities, sex and age groups were observed when the most frequently used botanicals were ranked. Conclusions The results provide new insights on the socio-economic characteristics and lifestyle of Italian PFS consumers, on their reasons for and pattern of use, and on their behaviour and expectations. The value of this information is not restricted to the specific country (Italy) but allows for a more general evaluation of the pattern of use, according to habits and geographical area
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