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61.
62.
Akiyuki Yokoyama Akiyuki Yokoyama Hiroyuki Sakakibara Akiyuki Yokoyama Hiroyuki Sakakibara Alan Crozier 《Free radical research》2013,47(10):913-921
Quercetin has strong antioxidant potency. Quercetin-3′-O-sulphate (Q3′S) and quercetin-3-O-glucuronide (Q3GA) are the main circulating metabolites after consumption of quercetin-O-glucoside-rich diets by humans. However, information about how these quercetin metabolites function in vivo is limited. Hence, this study evaluated the efficacy of Q3′S and Q3GA for the protection of oxidative injury using in vitro and in vivo experiments. Peroxynitrite-mediated hepatic injury in rats was induced by administration of galactosamine/lipopolysaccharide (GalN/LPS). Twenty-four hours after GalN/LPS treatment, plasma ALT and AST levels δ increased significantly. However, pretreatment with 4G-α-D-glucopyranosyl rutin, a quercetin glycoside (30 mg/kg body weight), prevented these increases and reduced nitrotyrosine formation, indicating that consumption of quercetin glycosides prevent oxidative hepatotoxicity. Moreover, physiological levels of Q3′S and Q3GA (1 µM) effectively prevented peroxynitrite-induced nitrotyrosine formation in human serum albumin in in vitro experiments. These findings indicate peroxynitrite-induced oxidative hepatotoxicity is protected by the in vivo metabolites of quercetin, Q3′S and Q3GA. 相似文献
63.
We used ethylenediaminetetraacetic acid dianhydride (EDTAD) to modify oxalate decarboxylase (OXDC) to improve its adsorption on calcium oxalate stones. The modified sites were identified by Ultra performance liquid chromatography-mass spectrometry (UPLC-MS) and the adsorption mechanism of the EDTAD-modified OXDC on calcium oxalate (CaOx) was investigated. We investigated adsorption time, initial enzyme concentration, temperature and solution pH on the adsorption process. Data were analyzed using kinetics, thermodynamics and isotherm adsorption models. UPLC-MS showed that EDTAD was attached to OXDC covalently and suggested that the chemical modification occurred at both the free amino of the side chain and the α-NH2 of the peptide. The adsorption capacity of the EDTAD-OXDC on calcium oxalate was 53.37% greater than that of OXDC at the initial enzyme concentration of 5 mg/ml, pH = 7.0, at 37° C. The modified enzyme (EDTAD-OXDC) demonstrated improved oxalate degradation activity at pH 4.5?6.0. Kinetic data fitting analysis suggested a pseudo second order kinetic model. Estimates of the thermodynamic parameters including ΔG0, ΔH0 and ΔS0 of the adsorption process showed it to be feasible, spontaneous and endothermic. Isotherm data fitting analysis indicated that the adsorption process is reduced to monolayer adsorption at a low enzyme concentration and to multilayer adsorption at a high enzyme concentration. It may be possible to apply OXDC to degradation of calcium oxalate stones. 相似文献
64.
65.
The flicker response contour for the frog Rana pipiens exhibits the duplex character typical for most vertebrates. By comparison (under the same conditions of temperature, 21.5°, and light-time fraction, = 0.5), the low intensity section of the F - log I curve is the smallest thus far found. The cone portion of the curve is satisfactorily described by a probability integral. The rod part represents the addition of a small group of sensory effects upon the lower end of the cone curve, from which it can be analytically separated. The relation between the two groups of sensory effects permits certain tests of the rule according to which (in homogeneous data) Im and σ1I1 are in direct proportion. 相似文献
66.
The upward geotropic orientation (angle θ) of adult rats (race A) has been measured as a function of slope of substratum. The relative variation of orientation angle is a declining rectilinear function of θ. The fraction of the total observable variation of performance (θ) which is controlled by the intensity of excitation (56 per cent) is identical with that found for young rats of the same strain, although the total variation is a little greater. Injection of adrenin distorts the θ vs. α graph in a manner quite concordant with the effect obtained in young rats. With the adults the absolute magnitudes of the variations of θ, at corresponding intensities of excitation, are not affected by the action of adrenin, and, as with the young, the proportion of modifiable variation of θ is not altered. The variability of performance, considered as a function of the performance, must therefore be regarded as an organic invariant. Certain consequences of this finding are referred to. 相似文献
67.
W. J. Crozier 《The Journal of general physiology》1927,8(6):671-684
When orientation is attained under the influence of beams of parallel light opposed at 180° the deflection θ from a path at right angles to the beams is given by tan See PDF for Equation, where I
1 and I
2 are the photic intensities and H is the average angle between the photoreceptive surfaces. This expression is independent of the units in which I is measured, and holds whether the primary photosensory effect is proportional to I or to log I. When photokinetic side-to-side motions of the head occur, H decreases with increasing total acting light intensity, but increases if higher total light intensity restricts the amplitude of random movements; in each case, H is very nearly proportional to log I
1
I
2. For beams of light at 90°, See PDF for Equation. The application of these equations to some particular instances is discussed, and it is shown why certain simpler empirical formulæ previously found by others yield fair concordance with the experimental data. The result is thus in complete accord with the tropism theory, since the equations are based simply on the assumption that when orientation is attained photic excitation is the same on the two sides. 相似文献
68.
The geotropic orientation of Rattus rattus (roof rat) obeys the equations previously found applicable for Rattus norvegicus. The former is more sensitive, geotiopically, and the numerical values of the constants in the equations for the two forms are found to differ significantly. Certain consequences of this difference are pointed out. 相似文献
69.
The temperature characteristic for respiratory production of CO2 by young seedlings of Phaseolus aureus (Roxb.) is µ = 16,500 calories, 12–21°C., even when the analyses depend upon the use of many seedlings crowded in a small respiration chamber, provided reasonable precautions are taken to avoid injury and to permit proper thermal adaptation. There is evidence of a definite critical temperature at 20–21°. These findings agree quantitatively with those obtained with other similar seedlings, and contradict the results reported by Kurbatov and Leonov (1930); the reasons for this are analysed. 相似文献
70.
Christina Vogel Sarah Crozier Daniel Penn-Newman Kylie Ball Graham Moon Joanne Lord Cyrus Cooper Janis Baird 《PLoS medicine》2021,18(9)
BackgroundPrevious product placement trials in supermarkets are limited in scope and outcome data collected. This study assessed the effects on store-level sales, household-level purchasing, and dietary behaviours of a healthier supermarket layout.Methods and findingsThis is a prospective matched controlled cluster trial with 2 intervention components: (i) new fresh fruit and vegetable sections near store entrances (replacing smaller displays at the back) and frozen vegetables repositioned to the entrance aisle, plus (ii) the removal of confectionery from checkouts and aisle ends opposite. In this pilot study, the intervention was implemented for 6 months in 3 discount supermarkets in England. Three control stores were matched on store sales and customer profiles and neighbourhood deprivation. Women customers aged 18 to 45 years, with loyalty cards, were assigned to the intervention (n = 62) or control group (n = 88) of their primary store. The trial registration number is . Interrupted time series analysis showed that increases in store-level sales of fruits and vegetables were greater in intervention stores than predicted at 3 (1.71 standard deviations (SDs) (95% CI 0.45, 2.96), P = 0.01) and 6 months follow-up (2.42 SDs (0.22, 4.62), P = 0.03), equivalent to approximately 6,170 and approximately 9,820 extra portions per store, per week, respectively. The proportion of purchasing fruits and vegetables per week rose among intervention participants at 3 and 6 months compared to control participants (0.2% versus −3.0%, P = 0.22; 1.7% versus −3.5%, P = 0.05, respectively). Store sales of confectionery were lower in intervention stores than predicted at 3 (−1.05 SDs (−1.98, −0.12), P = 0.03) and 6 months (−1.37 SDs (−2.95, 0.22), P = 0.09), equivalent to approximately 1,359 and approximately 1,575 fewer portions per store, per week, respectively; no differences were observed for confectionery purchasing. Changes in dietary variables were predominantly in the expected direction for health benefit. Intervention implementation was not within control of the research team, and stores could not be randomised. It is a pilot study, and, therefore, not powered to detect an effect.ConclusionsHealthier supermarket layouts can improve the nutrition profile of store sales and likely improve household purchasing and dietary quality. Placing fruits and vegetables near store entrances should be considered alongside policies to limit prominent placement of unhealthy foods.Trial registrationClinicalTrials.gov NCT03518151 (pre-results)Christina Vogel and colleagues assess the effects of creating a healthier layout in supermarkets in England on store-level sales, household-level purchasing, and dietary behaviors of women customers. NCT03518151相似文献