52 research outputs found
Therapiemöglichkeiten bei Schwangerschaftstübelkeit
Bis zu 85 Prozent der schwangeren Frauen leiden an Übelkeit in der Frühschwangerschaft, und weitere 25 Prozent zusätzlich an Erbrechen. Isabelle Arnet und Kurt Hersberger, beide im Departement für Pharmazeutik der Universität Basel tätig, und Ursula von Mandach, Präsidentin der Schweizerischen Arbeitsgemeinschaft für Perinatale Pharmakologie (SAPP), präsentieren aktuelle medikamentöse Therapieoptionen und die Mittel der ersten Wahl in der Selbstmedikation
Neutrino energy loss rates and positron capture rates on Co for presupernova and supernova physics
Proton-neutron quasi-particle random phase approximation (pn-QRPA) theory has
recently being used for calculation of stellar weak interaction rates of
-shell nuclide with success. Neutrino losses from proto-neutron stars play
a pivotal role to decide if these stars would be crushed into black holes or
explode as supernovae. The product of abundance and positron capture rates on
Co is substantial and as such can play a role in fine tuning of input
parameters of simulation codes specially in the presupernova evolution.
Recently we introduced our calculation of capture rates on Co, in a
luxurious model space of , employing the pn-QRPA theory with a
separable interaction. Simulators, however, may require these rates on a fine
scale. Here we present for the first time an expanded calculation of the
neutrino energy loss rates and positron capture rates on Co on an
extensive temperature-density scale. These type of scale is appropriate for
interpolation purposes and of greater utility for simulation codes. The pn-QRPA
calculated neutrino energy loss rates are enhanced roughly up to two orders of
magnitude compared with the large-scale shell model calculations and favor a
lower entropy for the core of massive stars.Comment: 27 pages, 6 figures, 5 table
Ground and excited states Gamow-Teller strength distributions of iron isotopes and associated capture rates for core-collapse simulations
This paper reports on the microscopic calculation of ground and excited
states Gamow-Teller (GT) strength distributions, both in the electron capture
and electron decay direction, for Fe. The associated electron and
positron capture rates for these isotopes of iron are also calculated in
stellar matter. These calculations were recently introduced and this paper is a
follow-up which discusses in detail the GT strength distributions and stellar
capture rates of key iron isotopes. The calculations are performed within the
framework of the proton-neutron quasiparticle random phase approximation
(pn-QRPA) theory. The pn-QRPA theory allows a microscopic
\textit{state-by-state} calculation of GT strength functions and stellar
capture rates which greatly increases the reliability of the results. For the
first time experimental deformation of nuclei are taken into account. In the
core of massive stars isotopes of iron, Fe, are considered to be
key players in decreasing the electron-to-baryon ratio () mainly via
electron capture on these nuclide. The structure of the presupernova star is
altered both by the changes in and the entropy of the core material.
Results are encouraging and are compared against measurements (where possible)
and other calculations. The calculated electron capture rates are in overall
good agreement with the shell model results. During the presupernova evolution
of massive stars, from oxygen shell burning stages till around end of
convective core silicon burning, the calculated electron capture rates on
Fe are around three times bigger than the corresponding shell model
rates. The calculated positron capture rates, however, are suppressed by two to
five orders of magnitude.Comment: 18 pages, 12 figures, 10 table
Biophysical aspects of handcycling performance in rehabilitation, daily life and recreational sports; a narrative review
Aim
In this narrative review the potential and importance of handcycling are evaluated. Four conceptual models form the framework for this review; (1) the International Classification of Functioning, Disability and Health; (2) the Stress-Strain-Capacity model; (3) the Human-Activity-Assistive Technology model; and (4) the power balance model for cyclic exercise.
Methods
Based on international handcycle experience in (scientific) research and practice, evidence-based benefits of handcycling and optimization of handcycle settings are presented and discussed for rehabilitation, daily life and recreational sports.
Results
As the load can be distributed over the full 360° cycle in handcycling, peak stresses in the shoulder joint and upper body muscles reduce. Moreover, by handcycling regularly, the physical capacity can be improved. The potential of handcycling as an exercise mode for a healthy lifestyle should be recognized and advocated much more widely in rehabilitation and adapted sports practice.
The interface between handcycle and its user should be optimized by choosing a suitable person-specific handcycle, but mainly by optimizing the handcycle dimensions to one’s needs and desires. These dimensions can influence efficient handcycle use and potentially improve both endurance and speed of handcycling.
Conclusion
To optimize performance in rehabilitation, daily life and recreational sports, continued and more systematic research is required.
Implications for rehabilitation
Handcycling allows users to travel farther distances at higher speeds and to train outdoors. It should be recognized as an alternative exercise modality for daily outdoor use, also already in early rehabilitation, while it contributes to a healthy lifestyle.
To individualize handcycle performance, the user-handcycle (assistive device) interface as well as the vehicle mechanics should be optimized to minimize external power and reduce friction, so that the upper body capacity can be efficiently used.
To optimize handcycling individual performance, both the physiological and biomechanical aspects of handcycling should be considered when monitoring or testing handcycle exercise
Handcycling: training effects of a specific dose of upper body endurance training in females
Purpose: This study aims to evaluate a handcycling training protocol based on ACSM guidelines in a well-controlled laboratory setting. Training responses of a specific dose of handcycling training were quantified in a homogeneous female subject population to obtain a more in depth understanding of physiological mechanisms underlying adaptations in upper body training. Methods: 22 female able-bodied participants were randomly divided in a training (T) and control group (C). T received 7-weeks of handcycling training, 3 × 30 min/week at 65 % heart rate reserve (HRR). An incremental handcycling test was used to determine local, exercise-specific adaptations. An incremental cycling test was performed to determine non-exercise-specific central/cardiovascular adaptations. Peak oxygen uptake (peakVO2), heart rate (peakHR) and power output (peakPO) were compared between T and C before and after training. Results: T completed the training sessions at 65 ± 3 % HRR, at increasing power output (59.4 ± 8.2 to 69.5 ± 8.9 W) over the training program. T improved on handcycling peakVO2 (+18.1 %), peakPO (+31.9 %), and peakHR (+4.0 %). No improvements were found in cycling parameters. Conclusion: Handcycling training led to local, exercise-specific improvements in upper body parameters. Results could provide input for the design of effective evidence-based training programs specifically aimed at upper body endurance exercise in females
Posttranscriptional and transcriptional regulation of endothelial nitric-oxide synthase during hypoxia: the role of microRNAs
- …