15 research outputs found

    Postexercise fat intake repletes intramyocellular lipids but no faster in trained than in sedentary subjects

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    The hypotheses that postexercise replenishment of intramyocellular lipids (IMCL) is enhanced by endurance training and that it depends on fat intake were tested. Trained and untrained subjects exercised on a treadmill for 2 h at 50% peak oxygen consumption, reducing IMCL by 26-22%. During recovery, they were fed 55% (high fat) or 15% (low fat) lipid energy diets. Muscle substrate stores were estimated by (1)H (IMCL)- and (13)C (glycogen)-magnetic resonance spectroscopy in tibialis anterior muscle before and after exercise. Resting IMCL content was 71% higher in trained than untrained subjects and correlated significantly with glycogen content. Both correlated positively with indexes of insulin sensitivity. After 30 h on the high-fat diet, IMCL concentration was 30-45% higher than preexercise, whereas it remained 5-17% lower on the low-fat diet. Training status had no significant influence on IMCL replenishment. Glycogen was restored within a day with both diets. We conclude that fat intake postexercise strongly promotes IMCL repletion independently of training status. Furthermore, replenishment of IMCL can be completed within a day when fat intake is sufficient

    Single-tooth replacement using dental implants supporting all-ceramic and metal-based reconstructions: results at 18 months of loading

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    The aim of this study was to compare customized zirconia and titanium abutments with respect to survival rates and technical, biologic, and esthetic outcomes. A total of 28 patients with single implants were randomly assigned to 12 customized zirconia (test, AC) and 16 customized titanium (control, MC) abutments. Technical, biologic, and esthetic outcomes were assessed after a mean follow-up time of 18 months. No biologic complications were observed, and no statistical difference for the bone-to-implant distance was found at 18 months (AC -0.05 ± 0.51 mm vs MC -0.28 ± 0.77 mm; P = .40). A similar discoloration of the peri-implant mucosa was observed (ΔEAC 9.6 ± 5.4, ΔEMC 7.6 ± 5.3; P = .46). The mean papilla score values evaluation presented no statistically significant differences between the test and control groups (AC 2.07 ± 0.94, MC 1.96 ± 0.84). At 18 months, reconstructions based on zirconia and titanium abutments exhibited similar survival rates and similar clinical outcomes

    Observation and identification of metabolites emerging during postmortem decomposition of brain tissue by means of in situ 1H-magnetic resonance spectroscopy

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    Postmortem decomposition of brain tissue was investigated by (1)H-magnetic resonance spectroscopy (MRS) in a sheep head model and selected human cases. Aiming at the eventual estimation of postmortem intervals in forensic medicine, this study focuses on the characterization and identification of newly observed metabolites. In situ single-voxel (1)H-MRS at 1.5 T was complemented by multidimensional homo- and heteronuclear high-resolution NMR spectroscopy of an extract of sheep brain tissue. The inclusion of spectra of model solutions in the program LC Model confirmed the assignments in situ. The first postmortem phase was characterized mainly by changes in the concentrations of metabolites usually observed in vivo and by the appearance of previously reported decay products. About 3 days postmortem, new metabolites, including free trimethylammonium, propionate, butyrate, and iso-butyrate, started to appear in situ. Since the observed metabolites and the time course is comparable in sheep and human brain tissue, the model system seems to be appropriate

    Single-Tooth Replacement Using Dental Implants Supporting All-Ceramic and Metal-Based Reconstructions: Results at 18 Months of Loading

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    The aim of this study was to compare customized zirconia and titanium abutments with respect to survival rates and technical, biologic, and esthetic outcomes. A total of 28 patients with single implants were randomly assigned to 12 customized zirconia (test, AC) and 16 customized titanium (control, MC) abutments. Technical, biologic, and esthetic outcomes were assessed after a mean follow-up time of 18 months. No biologic complications were observed, and no statistical difference for the bone-to-implant distance was found at 18 months (AC -0.05 ± 0.51 mm vs MC -0.28 ± 0.77 mm; P = .40). A similar discoloration of the peri-implant mucosa was observed (ΔE 9.6 ± 5.4, ΔE 7.6 ± 5.3; P = .46). The mean papilla score values evaluation presented no statistically significant differences between the test and control groups (AC 2.07 ± 0.94, MC 1.96 ± 0.84). At 18 months, reconstructions based on zirconia and titanium abutments exhibited similar survival rates and similar clinical outcomes

    Early assessment of brain maturation by MR imaging segmentation in neonates and premature infants

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    PURPOSE: We evaluated the impact of premature extrauterine life on brain maturation. PATIENTS AND METHODS: Twelve neonates underwent MR imaging at 40 (39.64 +/- 0.98) weeks (full term). Fifteen premature infants underwent 2 MR imaging examinations, after birth (preterm at birth) and at 40 weeks (41.03 +/- 1.33) (preterm at term). A 3D MR imaging technique was used to measure brain volumes compared with intracranial volume: total brain volume, cortical gray matter, myelinated white matter, unmyelinated white matter, basal ganglia (BG), and CSF. RESULTS: The average absolute volume of intracranial volume (269.8 mL +/- 36.5), total brain volume (246.5 +/- 32.3), cortical gray matter (85.53 mL +/- 22.23), unmyelinated white matter (142.4 mL +/-14.98), and myelinated white matter (6.099 mL +/-1.82) for preterm at birth was significantly lower compared with that for the preterm at term: the average global volume of intracranial volume (431.7 +/- 69.98), total brain volume (391 +/- 66,1), cortical gray matter (179 mL +/- 41.54), unmyelinated white matter (185.3 mL +/- 30.8), and myelinated white matter (10.66 mL +/- 3.05). It was also lower compared with that of full-term infants: intracranial volume (427.4 mL +/- 53.84), total brain volume (394 +/- 49.22), cortical gray matter (181.4 +/- 29.27), unmyelinated white matter (183.4 +/- 27.37), and myelinated white matter (10.72 +/- 4.63). The relative volume of cortical gray matter (30.62 +/- 5.13) and of unmyelinated white matter (53.15 +/- 4.8) for preterm at birth was significantly different compared with the relative volume of cortical gray matter (41.05 +/- 5.44) and of unmyelinated white matter (43.22 +/- 5.11) for the preterm at term. Premature infants had similar brain tissue volumes at 40 weeks to full-term infants. CONCLUSION: MR segmentation techniques demonstrate that cortical neonatal maturation in moderately premature infants at term and term-born infants was similar

    Pathways that make voices - White matter changes in auditory hallucinations

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    BACKGROUND: The origin of auditory hallucinations, which are one of the core symptoms of schizophrenia, is still a matter of debate. It has been hypothesized that alterations in connectivity between frontal and parietotemporal speech-related areas might contribute to the pathogenesis of auditory hallucinations. These networks are assumed to become dysfunctional during the generation and monitoring of inner speech. Magnetic resonance diffusion tensor imaging is a relatively new in vivo method to investigate the directionality of cortical white matter tracts. OBJECTIVE: To investigate, using diffusion tensor imaging, whether previously described abnormal activation patterns observed during auditory hallucinations relate to changes in structural interconnections between the frontal and parietotemporal speech-related areas. METHODS: A 1.5 T magnetic resonance scanner was used to acquire twelve 5-mm slices covering the Sylvian fissure. Fractional anisotropy was assessed in 13 patients prone to auditory hallucinations, in 13 patients without auditory hallucinations, and in 13 healthy control subjects. Structural magnetic resonance imaging was conducted in the same session. Based on an analysis of variance, areas with significantly different fractional anisotropy values between groups were selected for a confirmatory region of interest analysis. Additionally, descriptive voxel-based t tests between the groups were computed. RESULTS: In patients with hallucinations, we found significantly higher white matter directionality in the lateral parts of the temporoparietal section of the arcuate fasciculus and in parts of the anterior corpus callosum compared with control subjects and patients without hallucinations. Comparing patients with hallucinations with patients without hallucinations, we found significant differences most pronounced in the left hemispheric fiber tracts, including the cingulate bundle. CONCLUSION: Our findings suggest that during inner speech, the alterations of white matter fiber tracts in patients with frequent hallucinations lead to abnormal coactivation in regions related to the acoustical processing of external stimuli. This abnormal activation may account for the patients' inability to distinguish self-generated thoughts from external stimulation

    Breaking up time: negotiating the borders between present, past and future

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    This article sketches some of the recent evolutions in the study historical time. It proposes three issues that up to now have not received a lot of attention, but in our view deserve to be put on the research agenda. Three questions seem especially pertinent and urgent. First there is the question of how cultures in general and historians in particular distinguish ‘past’ from ‘present’ and ‘future’. We have a closer look at three historians as examples. Secondly, there is the question concerning the 'performative' character of temporal distinctions. Usually ‘the past’ is somehow supposed to ‘break off’ from ‘the present’ by itself, by its growing temporal ‘weight’ or distance – also in most philosophy of history. The article analyzes the distinguishing of the three temporal modes as a form of social action and proposes to regard the drawing of lines between the present and the past as a form of disciplinary ‘border patrol’ (Joan Scott). The third question concerns the political nature of the borders that separate these temporal dimensions. Following among others François Hartog we argue that time is not the entirely neutral medium that it is often believed to be, but that it is up to a certain degree, inherently ethical and political
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