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Dedicated to Professor Josef Breu on the Occasion of his 60 th BirthdayTo unambiguously clarify the long-debated crystal structure of the low-temperature orthoborate π-YBO 3 , single-crystals of the europium-doped π-YBO 3 :Eu 3 + were prepared via a highpressure/high-temperature route at 7.5 GPa and 1400 °C. The structure was solved and refined in the monoclinic space group C2/c (no. 15) in the pseudowollastonite structure type, with the lattice parameters a = 11.3407( 5), b = 6.5501(3), c = 9.5798(4) Å, and β = 113.08(2)°. This structure determination was corrobo-rated by powder X-ray diffraction and vibrational spectroscopy. 11 B as well as 89 Y MAS NMR spectroscopy was used to verify that our results are also accurate for the undoped π-YBO 3 and samples with varying europium content prepared under ambient pressure conditions. Additionally, the luminescence properties of the Eu 3 + doped π-orthoborate were determined in comparison with these ambient-pressure samples.

BackgroundTo effectively prevent injury in recreational alpine skiing, it is important to identify modifiable risk factors that can be targeted through exercise and training. Fatigue is a potential risk factor in recreational skiing, but no investigations have evaluated concentric/eccentric quadriceps and hamstring fatigue in recreational skiers. We tested the hypothesis that recreational skiing is associated with more pronounced eccentric as compared with concentric muscle fatigue.MethodsTwenty-four healthy and fit recreational skiers (14 male and 10 female) performed an isokinetic muscle test 1 day before, 1 h after, and 24 h after a 4 h skiing session. The testing protocol consisted of concentric and eccentric quadriceps and hamstring contractions for both legs.ResultsEccentric peak hamstring torque (both thighs) and eccentric peak quadriceps torque (left thigh) were reduced in male and female participants (p<0.05). Reduced peak torques were still present 24 h after the skiing session. There were no other significant findings.SummaryRecreational skiing is associated with prolonged (at least 24 h) eccentric quadriceps (left thigh) and hamstring (both thighs) fatigue in men and women. Eccentric quadriceps and hamstring fatigue may be a potential injury risk factor in male and female recreational skiers. This provides some justification for judicious use of additional eccentric training modalities for alpine skiing.

The title compound β-Eu(BO2)3 was synthesized in a high-pressure/high-temperature experiment at 4 GPa and 1473 K. The europium borate crystallizes in the orthorhombic space group Pnma (no. 62) with the lattice parameters a = 16.071(2), b = 7.440(4), and c = 12.362(5) Å. The structure is isotypic to the already known meta-borates β-RE(BO2)3 (RE = Y, Nd, Sm, Gd, Dy–Lu) and is built up of approximately triangular ribbons of BO4 tetrahedra. The compound was further characterized by X-ray powder diffraction, vibrational spectroscopy and shows a typical Eu3+ line emission upon excitation at 448 nm.