24 resultados para Fonvizin, D. I. (Denis Ivanovich), 1745-1792
Resumo:
Vitamin D deficiency is associated with a myriad of musculoskeletal disorders in the elderly, including osteoporosis, reduced muscle function, falls and fractures. Recent scientific trials, conducted mostly in elderly or institutionalized women, indicate that supplementation with at least 800<i> IU/d</i> of vitamin <i>D</i><i>3i> or a dose required to raise serum <i>25(OH)i> D levels to at least 75 <i>nmol/Li>, and approximately 1200 <i>mg/d</i> of calcium is most effective for improving many of these musculoskeletal and functional performance measures. While further targeted research is still needed in elderly men, vitamin D supplementation should be considered as a safe and low cost strategy to optimize musculoskeletal health and function in both elderly men and women.
Resumo:
Some of the most important outcomes of physical therapy treatment have to do with behaviour and quality of life. This article involves examining what it is we are measuring in physical therapy research and what those measurements mean. In looking at differences between groups (e.g. placebo-control) or strength of association between variables (e.g. correlation, regression) the practitioner/researcher must consider what are meaningful magnitudes of effects. Depending on the variable that one measures, a medium effect size (e.g. Cohen's <i>d</i>=0.50) may, in the real world, be insignificant, or in the case of elite athletic performance such an effect size might be gigantic. A major problem in the sports sciences is the confusion of p values and significance testing with the results of interest, the magnitudes of effects. Also, the prevalence of possible Type II errors in the sports sciences and medicine may be quite high in light of the small sample sizes and the paucity of power analyses for non-significant results. We make an appeal for determining a priori minimal meaningful differences (or associations) to use as the primary metrics in discussing results.
Resumo:
The 4-amino-1,8-naphthalimide-based anion receptor 3 binds dihydrogenphosphate with 1:1 stoichiometry through cooperative hydrogen bonding to a naphthalimide N–H and thiourea N–H groups. This was clearly established from 1H NMR titration experiments in DMSO-<i>d</i>6 where a substantial shift in the resonance for the naphthalimide N–H was observed concomitant with the expected thiourea N–H chemical shift migration upon successive additions of H2PO4−. However, whilst 1H NMR titration experiments indicate that 3 was capable of binding other anions such as acetate, the naphthalimide N–H does not participate and the N–H resonance was essentially invariant during the titration. The lack of cooperative binding in this instance was justifiable on steric grounds.
Resumo:
The dynamics of fatty acid composition modifications were examined in tissues of Murray cod fed diets containing fish oil (FO), canola oil (CO) and linseed oil (LO) for a 25-week period and subsequently transferred to a FO (finishing/wash-out) diet for a further 16 weeks. At the commencement of the wash-out period, following 25 weeks of vegetable oil substitution diets, the fatty acid compositions of Murray cod fillets were reflective of the respective diets. After transfer to the FO diet, differences decreased in quantity and in numerousness, resulting in a revert to the FO fatty acid composition. Changes in percentages of the fatty acids and total accumulation in the fillet could be described by exponential equations and demonstrated that major modifications occurred in the first days of the finishing period. A dilution model was tested to predict fatty acid composition. In spite of a general reliability of the model (<i>Yi>=0.9234<i>Xi>+0.4260, <i>Ri><i>2i>=0.957, <i>Pi><0.001, where <i>Xi> is the predicted percentage of fatty acid; Y the observed percentage of fatty acid), in some instances the regression comparing observed and predicted values was markedly different from the line of equity, indicating that the rate of change was higher than predicted (i.e. <i>Yi>=0.4205<i>Xi>+1.191, <i>Ri><i>2i>=0.974, P<0.001, where <i>Xi> is the predicted percentage of α-linolenic acid; Y the observed percentage of α-linolenic acid). Ultimately, using the coefficient of distance (<i>D</i>), it was shown that the fatty acid composition of fish previously fed the vegetable oil diets returned to the average variability of the fillet fatty acid composition of Murray cod after 70 or 97 days (LO and CO respectively).
Resumo:
The new charge neutral 4-amino-1,8-naphthalimide based anion sensors 2 and 3 bind to both acetate and dihydrogenphosphate with 1:1 stoichiometry through hydrogen bonding to both thiourea N–H atoms and in the case of dihydrogenphosphate, the naphthalimide 4 amino N–H group as well. This was clearly established from 1H NMR titration experiments with H2PO4- in DMSO-<i>d</i>6 where a substantial shift in the resonance for the naphthalimide N–H was observed concomitant with the expected migration of the thiourea N–H chemical shifts. The binding constants determined from the titration studies indicate that the new sensors bind H2PO4- more strongly than AcO−. Fluorescence titrations with sensor 3 indicate quenching of 59% and 36% upon addition of acetate and dihydrogenphosphate, respectively.
Resumo:
Consumption of some dietary fibres may benefit bowel health; however, the effect of Australian sweet lupin (<i>Lupinus angustifoliusi>) kernel fibre (LKFibre) is unknown. The present study examined the effect of a high-fibre diet containing LKFibre on bowel function and faecal putative risk factors for colon cancer compared to a control diet without LKFibre. Thirty-eight free-living, healthy men consumed an LKFibre and a control diet for 1 month each in a single-blind, randomized, crossover study. Depending on subject energy intake, the LKFibre diet was designed to provide 17–30 g/d fibre (in experimental foods) above that of the control diet. Bowel function self-perception, frequency of defecation, transit time, faecal output, pH and moisture, faecal levels of SCFA and ammonia, and faecal bacterial [ß]-glucuronidase activity were assessed. In comparison to the control diet, the LKFibre diet increased frequency of defecation by 0·13 events/d (<i>Pi> = 0·047), increased faecal output by 21 % (<i>Pi> = 0·020) and increased faecal moisture content by 1·6 % units (<i>P i>= 0·027), whilst decreasing transit time by 17 % (<i>Pi> = 0·012) and decreasing faecal pH by 0·26 units (<i>Pi> < 0·001). Faecal butyrate concentration was increased by 16 % (<i>Pi> = 0·006), butyrate output was increased by 40 % (<i>Pi> = 0·002) and [ß]-glucuronidase activity was lowered by 1·4 µmol/h per g wet faeces compared to the control diet (<i>Pi> < 0·001). Addition of LKFibre to the diet incorporated into food products improved some markers of healthy bowel function and colon cancer risk in men.
Resumo:
It is well established that mammalian skeletal muscles exhibit a considerable degree of plasticity and one of the main determining factors of this plasticity is the activity pattern and duration of motoneurone discharge. Lesions to the right substantia nigra pars compacta (SNpc) of six adult rats were made to determine whether altered output from the SNpc ultimately leads to a change in the expression of proteins in contralateral skeletal muscles. After 4 months, altered motor performance was identified by the administration of amphetamine. After 7 months, 30–70% of dopaminergic cells in the SNpc had been destroyed. The protein content of muscles was then quantified from densitometric scans of gels, and expressed as a % of the amount of actin (the protein used as a reference in this study). The lesion affected the expression of different protein isoforms in the fast- and slow-twitch muscles. In slow-twitch soleus muscles, the lesion decreased the proportion of α-tropomyosin and increased the proportion of β-tropomyosin. In the fast-twitch extensor digitorum longus muscles, the lesion increased the proportion of the fast isoform of troponin-T1f, and decreased the proportions of the two isoforms of myosin light chain. This study establishes a connection between the chronic effects of a lesion to the SNpc, with a loss of dopaminergic neurones, impaired motor performance, and altered expression of proteins in skeletal muscle. The implication of these results is that the altered motor function observed in Parkinson’s disease may be associated with alterations to the expression of skeletal muscle proteins.
Resumo:
We reported 11B nuclear magnetic resonance studies of boron nitride (BN) nanotubes prepared by mechano-thermal route. The NMR lineshape obtained at 192.493 MHz (14.7 T) was fitted with two Gaussian functions, and the 11B nuclear magnetization relaxations were satisfied with the stretched–exponential function, exp[-(<i>tli>T1)(D+1)/6] (<i>D</i>: space dimension) at all temperatures. In addition, the temperature dependence of spin–lattice relaxation rates was well described by <i>Ti>i</sub>-1 <i>= aTi> (<i>ai>: constant, <i>Ti>: temperature) and could be understood in terms of direct phonon process. All the <i>11i>BNMR results were explained by considering the inhomogeneous distribution of the paramagnetic metal catalysts, such as α-Fe, Fe–N, and Fe2 B, that were incorporated during the process of high-energy ball milling of boron powder and be synthesized during subsequent thermal annealing. X-ray powder diffraction as well as electron paramagnetic resonance (EPR) on BN nanotubes were also conducted and the results obtained supported these conclusions.
Resumo:
An extracellular exoinulinase( <i>2, 1- ß- D</i> fructan fructanohydrolase, EC 3.2.1.7), which catalyzes the hydrolysis of inulin into fructose and glucose, was purified 23.5-fold by ethanol precipitation, followed by Sephadex G-100 gel permeation from a cell-free extract of Kluyveromyces marxianus YS-1. The partially purified enzyme exhibited considerable activity between pH 5 to 6, with an optimum pH of 5.5, while it remained stable(100%) for 3 h at the optimum temperature of 50º c. <i>Mni><i>2+i> and <i>Cai>2+ produced a 2A-fold and 1.2-fold enhancement in enzyme activity, whereas <i>Hgi><i>2+i> and <i>Agi><i>2+i> completely inhibited the inulinase. A preparation of the partially purified enzyme effectively hydrolyzed inulin, sucrose, and raffinose, yet no activity was found with starch, lactose, and maltose. The enzyme preparation was then successfully used to hydrolyze pure inulin and raw inulin from Asparagus racemosus for the preparation of a high-fructose syrup. In a batch system, the exoinulinase hydrolyzed 84.8% of the pure inulin and 86.7% of the raw Asparagus racemosus inulin, where fructose represented 43.6mg/ml and 41.3mg/ml, respectively.
Resumo:
Systems characterised by general graphs are very flexible because of a given application they offer a great number of degrees of freedom and consequently a great possibility of choice to the designer. This can become a drawback in practice when myriads of cases have to be examined analytically and most of them rejected for a variety of heterogeneous reasons. For such design problems, it appears that logic programming languages are ideally suited because they can implement the heterogeneous rules which describe the desired system in a natural way. An application of the Prolog language to the design of active RC biquad circuits investigated by Mouly in his doctoral thesis illustrates the advantages of such a rule-based approach.
Resumo:
We report here, for the first time, the surface-enhanced Raman scattering (SERS) spectra of resveratrol using KNO3-aggregated citrate-reduced silver (Ag) colloids. The technique provided a substantial spectral enhancement and therefore good quality spectra of resveratrol at parts per million (ppm) concentrations. The detection limit was found to be <1 μM, equivalent to <0.2 ppm. The SERS profile additionally closely resembled its normal solid-state Raman spectrum with some changes in relative intensity. These intensity changes, together with a precise band assignment aided by density functional theory calculations at the <i>B3LYP/6–31G(d)i> level, allowed the determination of the structural orientation of the adsorbed resveratrol on the surface of the metal nanoparticles. In particular, the SERS spectra obtained at different resveratrol concentrations exhibited concentration-dependent features, suggesting an influence of surface coverage on the orientation of the adsorbed molecules. At a high concentration, an adoption of close-to-upright orientation of resveratrol adsorbed on the metal surface through the p-OH phenyl ring is favoured. The binding structure is, however, altered at lower surface coverage when the concentration decreases to a tilted orientation with the trans-olefin C=C bond aligning closer to parallel to the surface of the Ag nanoparticles.
Resumo:
An isolated, perfused salmon tail preparation showed oxyconformance at low oxygen delivery rates. Addition of pig red blood cells to the perfusing solution at a haematocrit of 5 or 10% allowed the tail tissues to oxyregulate. Below ca. 60 ml O2 kg−1 h−1 of oxygen delivery (<i>D</i>O2), <i>Vi>O2 was delivery dependent. Above this value additional oxygen delivery did not increase <i>Vi>O2 of resting muscle above ca. 35 ml O2 kg−1 h−1. Following electrical stimulation, <i>Vi>O2 increased to ca. 65 ml O2 kg−1 h−1, with a critical <i>D</i>O2 of ca. 150 ml O2 kg−1 h−1. Dorsal aortic pressure fell to 69% of the pre-stimulation value after 5 min of stimulation and to 54% after 10 min. Microspheres were used to determine blood flow distribution (BFD) to red (RM) and white muscle (WM) within the perfused myotome. Mass specific BFD ratio at rest was found to be 4.03 ± 0.49 (RM:WM). After 5 min of electrical stimulation the ratio did not change. Perfusion with saline containing the tetrazolium salt 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2<i>Hi>-tetrazolium bromide (MTT) revealed significantly more mitochondrial activity in RM. Formazan production from MTT was directly proportional to time of perfusion in both red and WM. The mitochondrial activity ratio (RM:WM) did not change over 90 min of perfusion.
Resumo:
Heart rate (HR) variability and large arterial compliance can be improved using fish oils. DHA, a component of fish oil, has cardiovascular health benefits, but its effect on HR variability (HRV) and arterial compliance is yet to be quantified. Sixty-seven overweight or obese adults (thirty-six males and thirty-one females; 53 (sem 2) year; BMI 31·7 (sem 1·1) kg/m2) were randomly allocated to consume either 6 g/d sunola oil (control; <i>ni> 17), fish oil (260 mg DHA+60 mg EPA per g) at doses of 2 g/d (<i>n i>16), 4 g/d (n 17) or 6 g/d (<i>ni> 17). Blood pressure, HR and compliance of large and small arteries were measured while supine at baseline and after 12 weeks in all participants, and HRV was assessed in a subgroup of forty-six participants. There was no effect of fish oil on blood pressure, small artery compliance or HR. However, the low frequency:high frequency ratio of HRV decreased with increasing doses of fish oil (<i>ri> − 0·34, <i>Pi> = 0·02), while large artery compliance increased (<i>ri> 0·34, P = 0·006). Moreover, the changes in these biomarkers were significantly correlated (<i>ri> − 0·31, P = 0·04) and may reflect fish oil-induced improvements in arterial function and cardiac autonomic regulation.
