The purpose of the present study was to investigate the physical performance of elite female football players during match play along with transient alterations in running performance following 1- and 5-min univariate peak periods. 54 elite female players from four top-level Norwegian teams were monitored for one season (n = 393 match observations), and physical performance data collected using STATSport GPS APEX. Results revealed significant differences in physical performance between the positions during full match play, particularly between wide and central players. Both full backs (FBs) and wide midfielders (WMs) covered more total distance (TD), high-speed running distance (HSRD), and sprint distance (SpD) than center backs (CBs) (p < 0.05-0.001), while WMs also covered more HSRD than both central midfielders (CMs) (p < 0.01) and forwards (FWs) (p < 0.05), and more acceleration -and deceleration distance (Accdist and Decdist ) than both CBs and CMs (p < 0.01-0.001). A similar pattern was observed for the peak period analysis, with FBs and WMs covering more SpD in peak 1 min than CBs and CM (p < 0.001) and more SpD in peak 5-min than CBs, CMs, and FWs (p < 0.001). Irrespective of the variable analyzed, greater distances were covered during the peak 5-min period than in the next-5 and mean 5-min periods (p < 0.001). Significant (p < 0.001), but small to trivial (Cohen's Dz : 0.07-0.20), decreases in distance covered were also observed for each variable following each univariate peak 5-min period. In conclusion, practitioners should account for differences in physical performance when developing training programs for female football players and be aware of transient reductions in physical performance following univariate peak 1- and 5-min periods. Specifically, the very high intensity in 1-min peak periods adds support to the principal of executing speed endurance activities during training to mirror and be prepared for the physical demands of match play.

To examine the effect of acetazolamide, known to increase cerebral blood flow (CBF) and glyceryl trinitrate (GTN), known to increase cerebral blood volume (CBV) on the blood oxygenation level‐dependent (BOLD) response in humans using 3 T magnetic resonance imaging (MRI), and to evaluate how pharmacological agents may modulate cerebral hemodynamic and thereby possibly the BOLD signal.

A lab-on-a-chip device that enables positioning of single or small ensembles of cells on an aperture in close proximity to a mercaptopropionic acid (MPA) modified sensing electrode has been developed and characterized. The microchip was used for the detection of Ca(2+)-dependent quantal catecholamine exocytosis from single as well as small assemblies of rat pheochromocytoma (PC12) cells. The frequency of events increased considerably upon depolarization of the PC12 cell membrane using a high extracelluar concentration of potassium. The number of recorded events could be correlated with the number of cells immobilized on the electrode. Quantal characteristics, such as the number of released molecules per recorded event, are equivalent to data obtained using conventional carbon fiber microelectrodes. The detection sensitivity of the device allows for the detection of less than 10 000 dopamine molecules in a quantal release. The distribution of peak rise-time and full width at half maximum was constant during measurement periods of several minutes demonstrating the stability of the MPA modified surface.

A feasible scheme for positioning of cells in a patch clamp biochip for high throughput drug screening comprises the application of suction by means of on-chip micro-pumps. A practical realization of such micro-pumps is based on Electro-Osmotic Flow (EOF). The principle of operation, and the design considerations for such pumps is described. Specific EOF pump geometries are demonstrated.

We present the successful integration of an electroosmotic flow pump and a patch-clamp orifice in the same package. When experiments are performed the electroosmotic pump is used both to position e.g. a single HEK293 cell on a micron-sized orifice and later to rupture the cell membrane, to bring the cell in the whole-cell configuration. In this configuration we are able to perform high quality electrophysiological ion-channel measurements. In the experiments we have used a sieve geometry for the pump. This design is a particularly promising candidate for such an integration scheme. The sieve pumps have relatively low volumetric flow rats, but are able to supply relatively high stall pressures (>200 mbar), which make the sieve pumps well suited to work on a load with high flow resistance e.g. a patch-clamp orifice. In the following we present a characterisation of such electroosmotic sieve pumps. For our system we were able to determine the zeta-potential of the glass/electrolyte interface of to be well above 10 mV. Furthermore we also present ion-channel measurements performed on this integrated platform.

Planar silicon chips with 1-2-microm etched holes (average resistance: 2.04 +/- 0.02 MOmega in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been developed using this technology. A single-channel prototype of the QPatch system was used for validation of the patch-clamp chip technology. We present here data on the quality of patch-clamp recordings and from actual drug screening studies of human potassium channels expressed in cultured cell lines. Using Chinese hamster ovary (CHO) and human embryonic kidney cells (HEK), gigaseals of 4.1 +/- 0.4 GOmega (n = 146) and high-quality whole-cell current recordings were obtained from hERG and KCNQ4 potassium channels. Success rates for gigaseal recordings varied from 40 to 95%, and 67% of the whole-cell configurations lasted for >20 min. Cells were maintained in suspension up to 4 h in a cell storage facility that is integrated in the QPatch 16. No decline in patchability was observed during this time course. A series of screens was conducted with known inhibitors of the hERG and KCNQ4 potassium channels. Dose-response relationship characterizations of verapamil and rBeKm-1 blockage of hERG currents provided IC(50) values similar to values reported in the literature.

We present calculations of the spin- and phase-relaxation rates in GaAs/Al1-xGaAs p-type quantum wells. These rates are used to derive the temperature dependence of the weak-localization correction to the conductivity. In p-type quantum wells both weak localization and weak antilocalization are present due to the strong spin-orbit interaction. When determining the total conductivity correction one also has to include the term due to hole-hole interaction. The magnitude of the latter depends on the ratio between the thermal energy and the Fermi energy, k(B)T/E-F and whether the system can be considered as ballistic (k(B)Ttau(tr)/(h) over bar >1) or diffusive (k(B) Ttau(tr)/(h) over bar <1). We argue that due to the relatively low Fermi energy and the moderate mobilities, in the p-type systems in question, the conductivity correction arising from hole-hole interactions is negligible at the highest temperatures accessible in the experiments. Hence the "metal-insulator" transition observed at these relatively high temperatures could be caused by interference effects. We compare our calculations of the weak antilocalization correction with the experimental results from different independent groups with special emphasis on the experiments by Simmons We find good agreement between predicted and observed transistion density p(c).