938 resultados para Effect of the pasture supplementation strategy in the growing period on performance


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In this work a detailed investigation of the exohedral reactivity of the most important and abundant endohedral metallofullerene (EMF) is provided, that is, Sc3N@Ih-C80 and its D5h counterpart Sc3N@D5h-C80, and the (bio)chemically relevant lutetium- and gadolinium-based M3N@Ih/D5h-C80 EMFs (M=Sc, Lu, Gd). In particular, we analyze the thermodynamics and kinetics of the Diels–Alder cycloaddition of s-cis-1,3-butadiene on all the different bonds of the Ih-C80 and D5h-C80 cages and their endohedral derivatives. First, we discuss the thermodynamic and kinetic aspects of the cycloaddition reaction on the hollow fullerenes and the two isomers of Sc3N@C80. Afterwards, the effect of the nature of the metal nitride is analyzed in detail. In general, our BP86/TZP//BP86/DZP calculations indicate that [5,6] bonds are more reactive than [6,6] bonds for the two isomers. The [5,6] bond D5h-b, which is the most similar to the unique [5,6] bond type in the icosahedral cage, Ih-a, is the most reactive bond in M3N@D5h-C80 regardless of M. Sc3N@C80 and Lu3N@C80 give similar results; the regioselectivity is, however, significantly reduced for the larger and more electropositive M=Gd, as previously found in similar metallofullerenes. Calculations also show that the D5h isomer is more reactive from the kinetic point of view than the Ih one in all cases which is in good agreement with experiments

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A reduced secretion of thyroid hormones with age has been documented in humans and animals with no substantial increase in TSH secretion, which may be indicative of an age-related impairment of the pituitary sensitivity to the negative control exerted by thyroid hormones. We have evaluated in rats the influence of sex and age on pituitary T3 nuclear receptors--known to be determinant in the regulation of TSH secretion--as well as on T3 concentration in the pituitary gland. As regards sex, the density of T3 receptors and the concentration of T3 in pituitary gland and plasma were greater in females than in males whereas pituitary and plasma TSH concentrations were less. As for age, the density of T3 receptors was greater in old male rats than in young ones with no changes in pituitary T3 and plasma TSH concentrations. In old female rats in contrast, there was no significant increase in T3 receptors but pituitary T3 was less and plasma TSH greater than in young female rats. In both sexes plasma thyroid hormones and pituitary TSH were reduced with age whereas TSH response to TRH was not altered. These results illustrate sex and age differences in pituitary T3 receptors and pituitary T3 concentration as well as in TSH secretion. In young animals of both sexes an inverse correlation is observed between the density of pituitary T3 receptors and plasma TSH. In contrast, in old animals the absence of this correlation is suggestive of an age-related impairment of T3 action on the thyrotrophs or of changes pertaining to other factors modulating TSH secretion.

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The study aimed to describe how violence is revealed in the production of the Research Group on Gender, Health and Nursing. This is a historical research of qualitative approach, which evaluated the production of the Research Group, through content analysis. The results show gender as a central category in determining violence and health practices. This aspect determines limitations on professional practices of coping, such as the invisibility of the problem. The female autonomy, the use of alcohol and drugs and social vulnerability play an important relation with the phenomenon and the bond is revealed as potentiality of health practices to address the problem. Conclusion: The gender perspective in nursing research is an innovative field and counter-hegemonic, a possibility to assume a meaning of praxis by transforming potential of understanding and modes of intervention in the phenomenon of gender violence.

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The aim of this single-blind, placebo-controlled study was to investigate the effects of the new beta-adrenergic compound Ro 40-2148 on resting energy expenditure (REE) at rest and after an oral glucose load in non-diabetic obese women before and after two weeks of treatment. After one week of placebo administration and after an overnight fast and one hour rest, REE and glucose and lipid oxidation rates were measured by indirect calorimetry (hood system) before and for 6 h after a single dose of placebo solution. A 75 g oral glucose tolerance test (OGTT) was performed during this period starting 90 min after the placebo administration. During the following two weeks, using a randomization design, six patients received Ro 40-2148 at a dose of 400 mg diluted in 100 ml water twice a day (i.e. 800 mg per day), while six others continued with the placebo administration. The same tests and measurements were repeated after two weeks, except for the treatment group which received the drug instead of the placebo. The 14-day period of drug administration did not increase REE measured in post-absorptive conditions. Similarly, there was no acute effect on REE of a 400 mg dose of Ro 40-2148. In contrast, glucose-induced thermogenesis was significantly increased after two weeks in the treatment group (means +/- s.e.m.: 3.7 +/- 1.3%, P = 0.047), while no change was observed in the placebo group (-0.8 +/- 0.7%, not significant). Since there was no significant change in the respiratory quotient, the increase in energy expenditure observed in the treatment group was due to stimulation of both lipid and glucose oxidation. The drug induced no variations in heart rate, blood pressure, axillary temperature or in plasma glucose, insulin and free fatty acid levels. In conclusion, this study shows that Ro 40-2148 activates glucose-induced thermogenesis in obese non-diabetic patients.

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PURPOSE: This study aimed at examining the influence of different playing surfaces on in-shoe loading patterns in each foot (back and front) separately during the first serve in tennis. METHODS: Ten competitive tennis players completed randomly five first (ie, flat) serves on two different playing surfaces: clay vs GreenSet. Maximum and mean force, peak and mean pressure, mean area, contact area and relative load were recorded by Pedar insoles divided into 9 areas for analysis. RESULTS: Mean pressure was significantly lower (123 ± 30 vs 98 ± 26 kPa; -18.5%; P < .05) on clay than on GreenSet when examining the entire back foot. GreenSet induced higher mean pressures under the medial forefoot, lateral forefoot and hallux of the back foot (+9.9%, +3.5% and +15.9%, respectively; both P < .01) in conjunction with a trend toward higher maximal forces in the back hallux (+15.1%, P = .08). Peak pressures recorded under the central and lateral forefoot (+21.8% and +25.1%; P < .05) of the front foot but also the mean area values measured on the back medial and lateral midfoot were higher (P < .05) on clay. No significant interaction between foot region and playing surface on relative load was found. CONCLUSIONS: It is suggested that in-shoe loading parameters characterizing the first serve in tennis are adjusted according to the ground type surface. A lesser asymmetry in peak (P < .01) and mean (P < .001) pressures between the two feet was found on clay, suggesting a greater need for stability on this surface.

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The whole body sweating response was measured at rest in eight women during the follicular (F) and the luteal (L) phases of the menstrual cycle. Subjects were exposed for 30-min to neutral (N) environmental conditions [ambient temperature (Ta) 28 degrees C] and then for 90-min to warm (W) environmental conditions (Ta, 35 degrees C) in a direct calorimeter. At the end of the N exposure, tympanic temperature (Tty) was 0.18 (SEM 0.06) degrees C higher in the L than in the F phase (P less than 0.05), whereas mean skin temperature (Tsk) was unchanged. During W exposure, the time to the onset of sweating as well as the concomitant increase in body heat content were similar in both phases. At the onset of sweating, the tympanic threshold temperature (Tty,thresh) was higher in the L phase [37.18 (SEM 0.08) degrees C] than in the F phase [36.95 (SEM 0.07) degrees C; P less than 0.01]. The magnitude of the shift in Tty,thresh [0.23 (SEM 0.07) degrees C] was similar to the L-F difference in Tty observed at the end of the N exposure. The mean skin threshold temperature was not statistically different between the two phases. The slope of the relationship between sweating rate and Tty was similar in F and L. It was concluded that the internal set point temperature of resting women exposed to warm environmental conditions shifted to a higher value during the L phase compared to the F phase of the menstrual cycle; and that the magnitude of the shift corresponded to the difference in internal temperature observed in neutral environmental conditions between the two phases.

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Cardiovascular magnetic resonance (CMR) has become an established imaging modality which provides often unique information on a wide range of cardiovascular diseases. The European Society of Cardiology (ESC) training curriculum reflects the emerging role of CMR by recommending that all trainees obtain a minimum level of training in CMR and by defining criteria for subspecialty training in CMR. 1 The wider use of CMR requires the definition of standards for data acquisition, reporting, and training in CMR across Europe. At the same time, training and accreditation in all cardiac imaging methods should be harmonized and integrated to promote the training of cardiac imaging specialists. The recommendations presented in this document are intended to inform the discussion about standards for accreditation and certification in CMR in Europe and the discussion on integrated imaging training. At present, the recommendations in this position statement are not to be interpreted as guidelines. Until such guidelines are available and nationally ratified, physicians will be able to train and practice CMR according to current national regulations.

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INTRODUCTION: In November 2009, the "3rd Summit on Osteoporosis-Central and Eastern Europe (CEE)" was held in Budapest, Hungary. The conference aimed to tackle issues regarding osteoporosis management in CEE identified during the second CEE summit in 2008 and to agree on approaches that allow most efficient and cost-effective diagnosis and therapy of osteoporosis in CEE countries in the future. DISCUSSION: The following topics were covered: past year experience from FRAX® implementation into local diagnostic algorithms; causes of secondary osteoporosis as a FRAX® risk factor; bone turnover markers to estimate bone loss, fracture risk, or monitor therapies; role of quantitative ultrasound in osteoporosis management; compliance and economical aspects of osteoporosis; and osteoporosis and genetics. Consensus and recommendations developed on these topics are summarised in the present progress report. CONCLUSION: Lectures on up-to-date data of topical interest, the distinct regional provenances of the participants, a special focus on practical aspects, intense mutual exchange of individual experiences, strong interest in cross-border cooperations, as well as the readiness to learn from each other considerably contributed to the establishment of these recommendations. The "4th Summit on Osteoporosis-CEE" held in Prague, Czech Republic, in December 2010 will reveal whether these recommendations prove of value when implemented in the clinical routine or whether further improvements are still required.

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The occurrence of heterostructures of cubic silicon/hexagonal silicon as disks defined along the nanowire (111) growth direction is reviewed in detail for Si nanowires obtained using Cu as catalyst. Detailed measurements on the structural properties of both semiconductor phases and their interface are presented. We observe that during growth, lamellar twinning on the cubic phase along the (111) direction is generated. Consecutive presence of twins along the (111) growth direction was found to be correlated with the origin of the local formation of the hexagonal Si segments along the nanowires, which define quantum wells of hexagonal Si diamond. Finally, we evaluate and comment on the consequences of the twins and wurtzite in the final electronic properties of the wires with the help of the predicted energy band diagram.

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The recently measured inclusive electron-proton cross section in the nucleon resonance region, performed with the CLAS detector at the Thomas Jefferson Laboratory, has provided new data for the nucleon structure function F2 with previously unavailable precision. In this paper we propose a description of these experimental data based on a Regge-dual model for F2. The basic inputs in the model are nonlinear complex Regge trajectories producing both isobar resonances and a smooth background. The model is tested against the experimental data, and the Q2 dependence of the moments is calculated. The fitted model for the structure function (inclusive cross section) is a limiting case of the more general scattering amplitude equally applicable to deeply virtual Compton scattering. The connection between the two is discussed.

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Introduction: Surgical decision making in lumbar spinal stenosis (LSS) takes into account primarily clinical symptoms as well as concordant radiological findings. We hypothesized that a wide variation of operative threshold would be found in particular as far as judgment of severity of radiological stenosis is concerned. Patients and methods: The number of surgeons who would proceed to decompression was studied relative to the perceived severity of radiological stenosis based either on measurements of dural sac cross sectional area (DSCA) or on the recently described morphological grading as seen on axial T2 MRI images. A link to an electronic survey page with a set of ten axial T2 MRI images taken from ten patients with either low back pain or LSS were sent to members of three national or international spine societies. Those 10 images were randomly presented initially and re-shuffled on a second page including this time DSCA measurements in mm2, ranging from 14 to 226 mm2, giving a total of 20 images to appraise. Morphological grades were ranging from grade A to D. Surgeons were asked if they would consider decompression given the radiological appearance of stenosis and that symptoms of neurological claudication were severe in patients who were otherwise fit for surgery. Fisher's exact test was performed following dichotomization of data when appropriate. Results: A total of 142 spine surgeons (113 orthopedic spine surgeons, 29 neurosurgeons) responded from 25 countries. A substantial agreement was observed in operating patients with severe (grade C) or extreme (grade D) stenosis as defined by the morphological grade compared to lesser stenosis (A&B) grades (p<0.0001). Decision to operate was not dependent on number of years in practice, medical density in practicing country or specialty although more neurosurgeons would operate on grade C stenosis (p<0.005). Disclosing the DSCA measurement did not alter the decision to operate. Although 20 surgeons only had prior knowledge of the description of the morphological grading, their responses showed no statistically significant difference with those of the remaining 122 physicians. Conclusions: This study showed that surgeons across borders are less influenced by DSCA in their decision making than by the morphological appearance of the dural sac. Classifying LSS according to morphology rather than surface measurements appears to be consistent with current clinical practice.

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Distribution of myosin, tubulin and laminin immunoreactive cells in the area opaca of the young chick embryo (Stages 4-8 HH) was studied using immunofluorescence technique. For the three markers, the number of stained cells increased with the age of the blastoderm. Cells stained for tubulin and laminin, were distributed throughout the area opaca, showing no supracellular organization. On the contrary, the cells stained for myosin became organized in a ring surrounding the area pellucida. This pattern appeared at the stage 6. Such an heterogenous distribution of the markers suggests a functional diversification of the ectodermal cell monolayer forming at these early developmental stages the area opaca. This idea is also supported by the results of autoradiography for tritiated thymidin which showed that the edge cells did not synthetize DNA and consequently did not divide.

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PURPOSE: Mutations within the KRAS proto-oncogene have predictive value but are of uncertain prognostic value in the treatment of advanced colorectal cancer. We took advantage of PETACC-3, an adjuvant trial with 3,278 patients with stage II to III colon cancer, to evaluate the prognostic value of KRAS and BRAF tumor mutation status in this setting. PATIENTS AND METHODS: Formalin-fixed paraffin-embedded tissue blocks (n = 1,564) were prospectively collected and DNA was extracted from tissue sections from 1,404 cases. Planned analysis of KRAS exon 2 and BRAF exon 15 mutations was performed by allele-specific real-time polymerase chain reaction. Survival analyses were based on univariate and multivariate proportional hazard regression models. RESULTS: KRAS and BRAF tumor mutation rates were 37.0% and 7.9%, respectively, and were not significantly different according to tumor stage. In a multivariate analysis containing stage, tumor site, nodal status, sex, age, grade, and microsatellite instability (MSI) status, KRAS mutation was associated with grade (P = .0016), while BRAF mutation was significantly associated with female sex (P = .017), and highly significantly associated with right-sided tumors, older age, high grade, and MSI-high tumors (all P < 10(-4)). In univariate and multivariate analysis, KRAS mutations did not have a major prognostic value regarding relapse-free survival (RFS) or overall survival (OS). BRAF mutation was not prognostic for RFS, but was for OS, particularly in patients with MSI-low (MSI-L) and stable (MSI-S) tumors (hazard ratio, 2.2; 95% CI, 1.4 to 3.4; P = .0003). CONCLUSION: In stage II-III colon cancer, the KRAS mutation status does not have major prognostic value. BRAF is prognostic for OS in MS-L/S tumors.