The TransEurope FootRace Project: longitudinal data acquisition in a cluster randomized mobile MRI observational cohort study on 44 endurance runners at a 64-stage 4,486 km transcontinental ultramarathon.

BACKGROUND: The TransEurope FootRace 2009 (TEFR09) was one of the longest transcontinental ultramarathons with an extreme endurance physical load of running nearly 4,500 km in 64 days. The aim of this study was to assess the wide spectrum of adaptive responses in humans regarding the different tissues, organs and functional systems being exposed to such chronic physical endurance load with limited time for regeneration and resulting negative energy balance. A detailed description of the TEFR project and its implemented measuring methods in relation to the hypotheses are presented. METHODS: The most important research tool was a 1.5 Tesla magnetic resonance imaging (MRI) scanner mounted on a mobile unit following the ultra runners from stage to stage each day. Forty-four study volunteers (67% of the participants) were cluster randomized into two groups for MRI measurements (22 subjects each) according to the project protocol with its different research modules: musculoskeletal system, brain and pain perception, cardiovascular system, body composition, and oxidative stress and inflammation. Complementary to the diverse daily mobile MR-measurements on different topics (muscle and joint MRI, T2*-mapping of cartilage, MR-spectroscopy of muscles, functional MRI of the brain, cardiac and vascular cine MRI, whole body MRI) other methods were also used: ice-water pain test, psychometric questionnaires, bioelectrical impedance analysis (BIA), skinfold thickness and limb circumference measurements, daily urine samples, periodic blood samples and electrocardiograms (ECG). RESULTS: Thirty volunteers (68%) reached the finish line at North Cape. The mean total race speed was 8.35 km/hour. Finishers invested 552 hours in total. The completion rate for planned MRI investigations was more than 95%: 741 MR-examinations with 2,637 MRI sequences (more than 200,000 picture data), 5,720 urine samples, 244 blood samples, 205 ECG, 1,018 BIA, 539 anthropological measurements and 150 psychological questionnaires. CONCLUSIONS: This study demonstrates the feasibility of conducting a trial based centrally on mobile MR-measurements which were performed during ten weeks while crossing an entire continent. This article is the reference for contemporary result reports on the different scientific topics of the TEFR project, which may reveal additional new knowledge on the physiological and pathological processes of the functional systems on the organ, cellular and sub-cellular level at the limits of stress and strain of the human body. Please see related articles: http://www.biomedcentral.com/1741-7015/10/76 and http://www.biomedcentral.com/1741-7015/10/77.

A mobile MRI field study of the biochemical cartilage reaction of the knee joint during a 4,486 km transcontinental multistage ultra-marathon using T2* mapping.

Nearly nothing is known about the consequences of ultra-long-distance running on knee cartilage. In this mobile MRI field study, we analysed the biochemical effects of a 4,486 km transcontinental multistage ultra-marathon on femorotibial joint (FTJ) cartilage. Serial MRI data were acquired from 22 subjects (20 male, 18 finisher) using a 1.5 T MR scanner mounted on a 38-ton trailer, travelling with the participants of the TransEurope FootRace (TEFR) day by day over 64 stages. The statistical analyses focused on intrachondral T2* behaviour during the course of the TEFR as the main outcome variable of interest. T2* mapping (sagittal FLASH T2* weighted gradient echo) is a validated and highly accurate method for quantitative compositional cartilage analysis of specific weightbearing areas of the FTJ. T2* mapping is sensitive to changes in the equilibrium of free intrachondral water, which depends on the content and orientation of collagen and the proteoglycan content in the extracellular cartilage matrix. Within the first 1,100 km, a significant running load-induced T2* increase occurred in all joint regions: 44.0% femoral-lateral, 42.9% tibial-lateral, 34.9% femoral-medial, and 25.1% tibial-medial. Osteochondral lesions showed no relevant changes or new occurrence during the TEFR. The reasons for stopping the race were not associated with knee problems. As no further T2* elevation was found in the second half of the TEFR but a decreasing T2* trend (recovery) was observed after the 3,500 km run, we assume that no further softening of the cartilage occurs with ongoing running burden over ultra-long distances extending 4,500 km. Instead, we assume the ability of the FTJ cartilage matrix to reorganize and adapt to the load.

Data on single pulse fs laser induced submicron bubbles in the subsurface region of soda-lime glass.

Submicron bubble formation in the subsurface range of soda-lime glass is investigated. The bubbles are induced by single femtosecond laser pulse irradiation with the wavelength of λ = 775 nm, the pulse duration of tp = 150 fs and the laser beam diameter of ∼12 µm. The data shows the changes of the morphologies of the soda-lime glass after laser irradiation with different pulse energy. Moreover, the data shows the detail of the cross-section view of the bubble during the Focused ion beam (FIB) cutting. It is found that the bubbles can be formed in a rather narrow pulse energy range with the bubbles in the size of 300 nm ∼3 µm which is much smaller than the laser beam diameter. Data presented in this article are related to the research article "Submicron bubbles/voids formation in the subsurface region of soda-lime glass by single pulse fs laser-induced spallation" [1].

It's all in our skin-Skin autofluorescence-A promising outcome predictor in cardiac surgery: A single centre cohort study.

BACKGROUND: The optimum risk score determining perioperative mortality and morbidity in cardiac surgery remains debated. Advanced glycation end products (AGEs) derived from glycaemic and oxidative stress accumulate to a comparable amount in skin and the cardiovascular system leading to a decline in organ function. We aimed to study the association between AGE accumulation measured as skin autofluorescence (sAF) and the outcome of cardiac surgery patients. METHODS: Between April 2008 and November 2016, data from 758 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement or a combined procedure were analyzed. Skin autofluorescence was measured using an autofluorescence reader. Beside mortality, for the combined categorical morbidity outcome of each patient failure of the cardiac-, pulmonary-, renal- and cerebral system, as well as reoperation and wound healing disorders were counted. Patients without or with only one of the outcomes were assigned zero points whereas more than one outcome failure resulted in one point. Odds ratios (ORs) were estimated in multivariable logistic regression analysis with other preoperative parameters and the established cardiac surgery risk score systems EuroSCORE II and STS score. RESULTS: Skin autofluorescence as non-invasive marker of tissue glycation provided the best prognostic value in identifying patients with major morbidity risks after cardiac surgery (OR = 3.13; 95%CI 2.16-4.54). With respect to mortality prediction the STS score (OR = 1.24; 95%CI 1.03-1.5) was superior compared to the EuroSCORE II (OR = 1.17: 95%CI 0.96-1.43), but not superior when compared to sAF (OR = 6.04; 95%CI 2.44-14.95). CONCLUSION: This finding suggests that skin autofluorescence is a good biomarker candidate to assess the perioperative risk of patients in cardiac surgery. Since the EuroSCORE does not contain a morbidity component, in our view further sAF measurement is an option.

Pre-race determinants influencing performance and finishing of a transcontinental 4486-km ultramarathon.

BACKGROUND: Pre-race determinants influencing performance and finishing of one of the largest transcontinental multistage ultramarathons were investigated. METHODS: Forty-four participants of the TransEurope FootRace 2009 (TEFR), running 4486 km in 64 stages (average 70.1 km daily) were analyzed regarding training and running history. This included years of regular endurance running (PRY), number of finished marathons, ultramarathons (UM) and multistage ultramarathons (MSUM), pre-race records (PRR) for marathon and specific UM races and the extent of pre-race training (PRT) in the last year before TEFR: volume (km/week), duration (h/week) and intensity (km/h). RESULTS: Mean total running speed during TEFR was 8.25 km/h.Seventy-one percent of subjects finished the race. The mean PRT-volume extends 5500 km. Finishers and non-finishers of the TEFR did not show significant difference in any tested pre-race determinants. There was no association between PRY, number of finished marathons, UM, and MSUM and TEFR performance. There was very strong positive correlation between PRT-intensity and TEFR performance. PRT volume correlated with a medium effect size to TEFR performance. PRR in specific ultra-races (6-hour, 50-km, 100-km races) showed a high correlation to TEFR performance. Performance in ultramarathon correlates inversely with age. CONCLUSIONS: Like in other endurance disciplines with shorter distances, in ultra-long multistage endurance running the athletes also need a stage-specific pre-race experience, training and adaptation if he wants to end up with a good performance. But dropping out of a MSUM seems not to be consistent with regard to specific pre-race experience. Further research results of TEFR project may reveal potential risk factors for non-finishing a transcontinental footrace.

Direct Measurement of Crystal Growth Velocity in Epitaxial Phase-Change Material Thin Films.

Central to the use of Ge-Sb-Te based phase-change materials for data storage applications is their crystallization capability since it determines memory writing time. Although being intensively studied to identify intrinsic limits and develop strategies to enhance memory performance, the crystallization process in these materials is still not fully explored. Therefore, this study focuses on the determination of crystal growth dynamics in an epitaxial phase-change material thin film model system offering the advantage of high crystalline quality and application-relevant sizing. By introducing a method that combines time-resolved reflectivity measurements with high-resolution scanning transmission electron microscopy, crystal growth velocities upon fast cooling after single ns-laser pulse irradiation of the prototypical phase-change material Ge2Sb2Te5 are determined. As a result, an increase in crystal growth velocity from 0.4 to 1.7 m/s with increasing laser fluence is observed with a maximum rate of 1.7 m/s as the upper detectable limit of the studied material.

Crystallization of Ge2Sb2Te5 thin films by nano- and femtosecond single laser pulse irradiation.

The amorphous to crystalline phase transformation of Ge2Sb2Te5 (GST) films by UV nanosecond (ns) and femtosecond (fs) single laser pulse irradiation at the same wavelength is compared. Detailed structural information about the phase transformation is collected by x-ray diffraction and high resolution transmission electron microscopy (TEM). The threshold fluences to induce crystallization are determined for both pulse lengths. A large difference between ns and fs pulse irradiation was found regarding the grain size distribution and morphology of the crystallized films. For fs single pulse irradiated GST thin films, columnar grains with a diameter of 20 to 60 nm were obtained as evidenced by cross-sectional TEM analysis. The local atomic arrangement was investigated by high-resolution Cs-corrected scanning TEM. Neither tetrahedral nor off-octahedral positions of Ge-atoms could be observed in the largely defect-free grains. A high optical reflectivity contrast (~25%) between amorphous and completely crystallized GST films was achieved by fs laser irradiation induced at fluences between 13 and 16 mJ/cm(2) and by ns laser irradiation induced at fluences between 67 and 130 mJ/cm(2). Finally, the fluence dependent increase of the reflectivity is discussed in terms of each photon involved into the crystallization process for ns and fs pulses, respectively.