28 resultados para High-intensity exercise
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Attempting to achieve the high diversity of training goals in modern competitive alpine skiing simultaneously can be difficult and may lead to compromised overall adaptation. Therefore, we investigated the effect of block training periodization on maximal oxygen consumption (VO2max) and parameters of exercise performance in elite junior alpine skiers. Six female and 15 male athletes were assigned to high-intensity interval (IT, N = 13) or control training groups (CT, N = 8). IT performed 15 high-intensity aerobic interval (HIT) sessions in 11 days. Sessions were 4 x 4 min at 90-95% of maximal heart rate separated by 3-min recovery periods. CT continued their conventionally mixed training, containing endurance and strength sessions. Before and 7 days after training, subjects performed a ramp incremental test followed by a high-intensity time-to-exhaustion (tlim) test both on a cycle ergometer, a 90-s high-box jump test as well as countermovement (CMJ) and squat jumps (SJ) on a force plate. IT significantly improved relative VO2max by 6.0% (P < 0.01; male +7.5%, female +2.1%), relative peak power output by 5.5% (P < 0.01) and power output at ventilatory threshold 2 by 9.6% (P < 0.01). No changes occurred for these measures in CT. tlim remained unchanged in both groups. High-box jump performance was significantly improved in males of IT only (4.9%, P < 0.05). Jump peak power (CMJ -4.8%, SJ -4.1%; P < 0.01), but not height decreased in IT only. For competitive alpine skiers, block periodization of HIT offers a promising way to efficiently improve VO2max and performance. Compromised explosive jump performance might be associated with persisting muscle fatigue.
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During the past decade microbeam radiation therapy has evolved from preclinical studies to a stage in which clinical trials can be planned, using spatially fractionated, highly collimated and high intensity beams like those generated at the x-ray ID17 beamline of the European Synchrotron Radiation Facility. The production of such microbeams typically between 25 and 100 microm full width at half maximum (FWHM) values and 100-400 microm center-to-center (c-t-c) spacings requires a multislit collimator either with fixed or adjustable microbeam width. The mechanical regularity of such devices is the most important property required to produce an array of identical microbeams. That ensures treatment reproducibility and reliable use of Monte Carlo-based treatment planning systems. New high precision wire cutting techniques allow the fabrication of these collimators made of tungsten carbide. We present a variable slit width collimator as well as a single slit device with a fixed setting of 50 microm FWHM and 400 microm c-t-c, both able to cover irradiation fields of 50 mm width, deemed to meet clinical requirements. Important improvements have reduced the standard deviation of 5.5 microm to less than 1 microm for a nominal FWHM value of 25 microm. The specifications of both devices, the methods used to measure these characteristics, and the results are presented.
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Transcatheter aortic valve implantation (TAVI) is an alternative to surgery for high-risk patients with severe aortic valve stenosis. Periprocedural stroke is reported at an incidence up to 10%. Magnetic resonance imaging studies have identified new onset of clinically silent ischaemic cerebral lesions more frequently (68-84%). So far, few data are available about cerebral embolism during TAVI. The aim of this study was to determine the frequency of high-intensity transient signals (HITS) and to explore differences in the HITS pattern between transfemoral and transapical access and between self-expanding (SE) and balloon-expandable (BE) deployment technique.
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The DNA-enabled dimerization of pentamethine cyanine (Cy5) dyes was studied by optical methods. The value of cyanine as a chiroptical reporter using a monomer-to-dimer switch is demonstrated. The specific shape of the CD signal and its high intensity are a result of J-type assembly.
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Im vorliegenden Beitrag wird die Entwicklung von Schülerinnen und Schülern aus Ganztagsschulen, welche die Angebote intensiv nutzen im Vergleich zu Schülerinnen und Schülern, die nur den Unterricht besuchen (Kontrollgruppe) bezüglich (a) des prosozialen Verhaltens und (b) der sozio-emotionalen Verhaltensstärken bzw. Verhaltensauffälligkeiten untersucht. Die Teilstichprobe umfasst N = 295 Schüler aus 43 Primarschulklassen und 35 Schulen in der Deutschschweiz, die im Rahmen einer quasi-experimentellen Längsschnittstudie in den ersten drei Primarschuljahren untersucht wurden. Die Ergebnisse zeigen, dass es der Ganztagsschule insgesamt nicht gelingt, die Entwicklung des prosozialen Verhaltens oder der sozio-emotionalen Verhaltensstärken der Schülerinnen und Schüler positiv zu beeinflussen. Im Weiteren bestätigen die Befunde einen Zusammenhang zwischen der pädagogischen Qualität der Ganztagsschulangebote und der sozio-emotionalen Entwicklung von Primarschulkindern.
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The addition of anti-CD20 antibodies to high intensity polychemotherapy regimens has improved response and survival rates in newly diagnosed patients with Burkitt lymphoma (BL). However, the role of additional anti-CD20 directed radioimmunotherapy for consolidation of first remission (CR1) has not been reported so far in BL patients receiving rituximab during first-line treatment. We compared five BL patients receiving Y-90-IT radioimmunotherapy consolidation in CR1 to 22 consecutive BL patients without consolidation. We observed that Y-90-IT treatment was associated with clinically relevant myelosuppression. After a median follow-up of 50 months, none of the patients with Y-90-IT treatment relapsed, and no patient died. In contrast, one patient (4.5%) in the non-Y-90-IT group relapsed (50 months-PFS 95.5%; p = 0.6336), and one patient died (50 months-OS 95.5%; p = 0.6171). In conclusion, our data suggest that survival rates are excellent and equal in rituximab pretreated BL patients with or without Y-90-IT consolidation in first remission.
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Objectives The aim of this study was to quantify potential differences in count, frequency and pattern of high-intensity transient signals (HITS) during transapical transcatheter aortic valve implantation (TA-TAVI), by comparing the Symetis Acurate TA (SA) with the balloon-expandable Edwards Sapien XT (ES) system. Background Recently, the Symetis Acurate TA revalving system has been introduced for TA-TAVI. The Symetis Acurate TA aortic bioprosthesis is self-expanding and is deployed by a specific two-step implantation technique. Whether this novel method increases the load of intraprocedural emboli, detected by transcranial Doppler ultrasound (TCD) as HITS, or not is not clear. Methods Twenty-two patients (n = 11 in each study arm, median logistic EuroScore 20%, median STS score 7%) displayed continuous TCD signals of good quality throughout the entire TA-TAVI procedure and were included in the final analysis. Data are presented as median with interquartile ranges. Results No significant differences were detected in total procedural or interval-related HITS load (SA: 303 [200; 594], ES: 499 [285; 941]; p = 0.16). With both devices, HITS peaked during prosthesis deployment (PD), whereas significantly fewer HITS occurred during instrumentation (SA: p = 0.002; ES: <0.001) or post-implantation PI (SA: p = 0.007; ES: <0.001). PD-associated HITS amounted to almost half of the total HITS load. One patient suffered new disabling stroke at 30 days. Thirty-day mortality amounted to 13.6% (3 of 22 patients). Conclusions Simplified transapical delivery using the self-expanding SA device does not increase HITS, despite of a two-step deployment technique with more interactions with the native aortic valve, when compared to the balloon-expandable ES valve. The similarity in HITS count, frequency and pattern with the two systems suggests a common mechanism for the release of cerebral microemboli.
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Land-use intensification is a key driver of biodiversity change. However, little is known about how it alters relationships between the diversities of different taxonomic groups, which are often correlated due to shared environmental drivers and trophic interactions. Using data from 150 grassland sites, we examined how land-use intensification (increased fertilization, higher livestock densities, and increased mowing frequency) altered correlations between the species richness of 15 plant, invertebrate, and vertebrate taxa. We found that 54% of pairwise correlations between taxonomic groups were significant and positive among all grasslands, while only one was negative. Higher land-use intensity substantially weakened these correlations (35% decrease in r and 43% fewer significant pairwise correlations at high intensity), a pattern which may emerge as a result of biodiversity declines and the breakdown of specialized relationships in these conditions. Nevertheless, some groups (Coleoptera, Heteroptera, Hymenoptera and Orthoptera) were consistently correlated with multidiversity, an aggregate measure of total biodiversity comprised of the standardized diversities of multiple taxa, at both high and low land-use intensity. The form of intensification was also important; increased fertilization and mowing frequency typically weakened plant–plant and plant–primary consumer correlations, whereas grazing intensification did not. This may reflect decreased habitat heterogeneity under mowing and fertilization and increased habitat heterogeneity under grazing. While these results urge caution in using certain taxonomic groups to monitor impacts of agricultural management on biodiversity, they also suggest that the diversities of some groups are reasonably robust indicators of total biodiversity across a range of conditions. Read More: http://www.esajournals.org/doi/10.1890/14-1307.1
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BACKGROUND 2013 AHA/ACC guidelines on the treatment of cholesterol advised to tailor high-intensity statin after ACS, while previous ATP-III recommended titration of statin to reach low-density lipoprotein cholesterol (LDL-C) targets. We simulated the impact of this change of paradigm on the achievement of recommended targets. METHODS Among a prospective cohort study of consecutive patients hospitalized for ACS from 2009 to 2012 at four Swiss university hospitals, we analyzed 1602 patients who survived one year after recruitment. Targets based on the previous guidelines approach was defined as (1) achievement of LDL-C target < 1.8 mmol/l, (2) reduction of LDL-C ≥ 50% or (3) intensification of statin in patients who did not reach LDL-C targets. Targets based on the 2013 AHA/ACC guidelines approach was defined as the maximization of statin therapy at high-intensity in patients aged ≤75 years and moderate- or high-intensity statin in patients >75 years. RESULTS 1578 (99%) patients were prescribed statin at discharge, with 1120 (70%) at high-intensity. 1507 patients (94%) reported taking statin at one year, with 909 (57%) at high-intensity. Among 482 patients discharged with sub-maximal statin, intensification of statin was only observed in 109 patients (23%). 773 (47%) patients reached the previous LDL-C targets, while 1014 (63%) reached the 2013 AHA/ACC guidelines targetsone year after ACS (p value < 0.001). CONCLUSION The application of the new 2013 AHA/ACC guidelines criteria would substantially increase the proportion of patients achieving recommended lipid targets one year after ACS. Clinical trial number, NCT01075868.
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The aim of this study was to test the effects of a sustained nystagmus on the head impulse response of the vestibulo-ocular reflex (VOR) in healthy subjects. VOR gain (slow-phase eye velocity/head velocity) was measured using video head impulse test goggles. Acting as a surrogate for a spontaneous nystagmus (SN), a post-rotatory nystagmus (PRN) was elicited after a sustained, constant-velocity rotation, and then head impulses were applied. 'Raw' VOR gain, uncorrected for PRN, in healthy subjects in response to head impulses with peak velocities in the range of 150°/s-250°/s was significantly increased (as reflected in an increase in the slope of the gain versus head velocity relationship) after inducing PRN with slow phases of nystagmus of high intensity (>30°/s) in the same but not in the opposite direction as the slow-phase response induced by the head impulses. The values of VOR gain themselves, however, remained in the normal range with slow-phase velocities of PRN < 30°/s. Finally, quick phases of PRN were suppressed during the first 20-160 ms of a head impulse; the time frame of suppression depended on the direction of PRN but not on the duration of the head impulse. Our results in normal subjects suggest that VOR gains measured using head impulses may have to be corrected for any superimposed SN when the slow-phase velocity of nystagmus is relatively high and the peak velocity of the head movements is relatively low. The suppression of quick phases during head impulses may help to improve steady fixation during rapid head movements.
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BACKGROUND Continuous venovenous hemodialysis (CVVHD) may generate microemboli that cross the pulmonary circulation and reach the brain. The aim of the present study was to quantify (load per time interval) and qualify (gaseous vs. solid) cerebral microemboli (CME), detected as high-intensity transient signals, using transcranial Doppler ultrasound. MATERIALS AND METHODS Twenty intensive care unit (ICU group) patients requiring CVVHD were examined. CME were recorded in both middle cerebral arteries for 30 minutes during CVVHD and a CVVHD-free interval. Twenty additional patients, hospitalized for orthopedic surgery, served as a non-ICU control group. Statistical analyses were performed using the Mann-Whitney U test or the Wilcoxon matched-pairs signed-rank test, followed by Bonferroni corrections for multiple comparisons. RESULTS In the non-ICU group, 48 (14.5-169.5) (median [range]) gaseous CME were detected. In the ICU group, the 67.5 (14.5-588.5) gaseous CME detected during the CVVHD-free interval increased 5-fold to 344.5 (59-1019) during CVVHD (P<0.001). The number of solid CME was low in all groups (non-ICU group: 2 [0-5.5]; ICU group CVVHD-free interval: 1.5 [0-14.25]; ICU group during CVVHD: 7 [3-27.75]). CONCLUSIONS This observational pilot study shows that CVVHD was associated with a higher gaseous but not solid CME burden in critically ill patients. Although the differentiation between gaseous and solid CME remains challenging, our finding may support the hypothesis of microbubble generation in the CVVHD circuit and its transpulmonary translocation toward the intracranial circulation. Importantly, the impact of gaseous and solid CME generated during CVVHD on brain integrity of critically ill patients currently remains unknown and is highly debated.
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High-energy e(-) and pi(-) were measured by the multichannel plate (MCP) detector at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The measurements provide the absolute detection efficiencies for these particles: 5.8% +/- 0.5% for electrons in the beam momenta range 17.5-300 MeV/c and 6.0% +/- 1.3% for pions in the beam momenta range 172-345 MeV/c. The pulse height distribution determined from the measurements is close to an exponential function with negative exponent, indicating that the particles penetrated the MCP material before producing the signal somewhere inside the channel. Low charge extraction and nominal gains of the MCP detector observed in this study are consistent with the proposed mechanism of the signal formation by penetrating radiation. A very similar MCP ion detector will be used in the Neutral Ion Mass (NIM) spectrometer designed for the JUICE mission of European Space Agency (ESA) to the Jupiter system, to perform measurements of the chemical composition of the Galilean moon exospheres. The detection efficiency for penetrating radiation determined in the present studies is important for the optimisation of the radiation shielding of the NIM detector against the high-rate and high-energy electrons trapped in Jupiter's magnetic field. Furthermore, the current studies indicate that MCP detectors can be useful to measure high-energy particle beams at high temporal resolution. (C) 2015 AIP Publishing LLC.
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To compare intraoperative cerebral microembolic load between minimally invasive extracorporeal circulation (MiECC) and conventional extracorporeal circulation (CECC) during isolated surgical aortic valve replacement (SAVR), we conducted a randomized trial in patients undergoing primary elective SAVR at a tertiary referral hospital. The primary outcome was the procedural phase-related rate of high-intensity transient signals (HITS) on transcranial Doppler ultrasound. HITS rate was used as a surrogate of cerebral microembolism in pre-defined procedural phases in SAVR using MiECC or CECC with (+F) or without (-F) an oxygenator with integrated arterial filter. Forty-eight patients were randomized in a 1:1 ratio to MiECC or CECC. Due to intraprocedural Doppler signal loss (n = 3), 45 patients were included in final analysis. MiECC perfusion regimen showed a significantly increased HITS rate compared to CECC (by a factor of 1.75; 95% confidence interval, 1.19-2.56). This was due to different HITS rates in procedural phases from aortic cross-clamping until declamping [phase 4] (P = 0.01), and from aortic declamping until stop of extracorporeal perfusion [phase 5] (P = 0.05). Post hoc analysis revealed that MiECC-F generated a higher HITS rate than CECC+F (P = 0.005), CECC-F (P = 0.05) in phase 4, and CECC-F (P = 0.03) in phase 5, respectively. In open-heart surgery, MiECC is not superior to CECC with regard to gaseous cerebral microembolism. When using MiECC for SAVR, the use of oxygenators with integrated arterial line filter appears highly advisable. Only with this precaution, MiECC confers a cerebral microembolic load comparable to CECC during this type of open heart surgery.