Rotational traction testing : How can we improve the current test device?

Rotational resistance is an important sports surface property in optimising both performance and safety for participants. Despite various attempts to create valid devices to measure the rotational traction, the Studded Boot Apparatus (SBA) originally developed in 1975 is still used in the synthetic turf standards of many governing bodies of sport. In addition to validity limitations, poor operator reliability of the SBA has been reported and it was postulated that the manual nature of the device contributed significantly to this result. Therefore, the aim of this paper is to present data on the automation of the SBA and to discuss the reliability and validity issues of the device. An automated version of the SBA was developed called the UB Turf Tester (UBTT) and data was collected by ten inexperienced operators using the original SBA and the UBTT. Testing was undertaken on a synthetic turf and each operator completed ten trials with each device. Despite a slightly greater peak traction value for the UBTT, there was no significant difference between the peak traction for the two devices, F 1,2 = 0.341, p = 0.57. Greater reliability was found between operators for the UB Turf Tester. Given that the SBA is still commonly used to comply with standards, achieving the highest level of intra- and inter-operator reliability is both desirable and invaluable. However, the research on the validity of the device also needs to continue. Interestingly, limitations of the device were identified when it was first developed but very few adaptations have been implemented since then. Undoubtedly, the interaction between the human and the surface is a complex phenomenon but the weight force, the level of penetration, the pattern, shape and position of the cleats and the possibility of measuring rotational stiffness rather than peak traction all require further discussion and investigation

The effect of stud configuration on rotational traction using the studded boot apparatus

Due to its associated injury risk, rotational traction is a frequently measured natural turf surface property. The most commonly used equipment, the studded boot apparatus (SBA), consists of a circular stud configuration that does not replicate the stud pattern on a regular football boot and may under or over estimate the surface traction. The aim of this study was to establish potential differences in the rotational traction measured between the current stud configuration on the SBA and the stud configuration on the most commonly used Australian football boots. The original studded boot had significantly higher rotational traction than the moulded stud sole or bladed sole. Location, quality and time tested all interacted significantly with the rotational traction measured. The current SBA may not accurately represent the rotational traction experienced by football players, and consequently may not be the most appropriate configuration to assess the relationship between rotational traction and injuries. © 2012 International Sports Engineering Association

Genome-wide association study identifies six new loci influencing pulse pressure and mean arterial pressure.

Numerous genetic loci have been associated with systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Europeans. We now report genome-wide association studies of pulse pressure (PP) and mean arterial pressure (MAP). In discovery (N = 74,064) and follow-up studies (N = 48,607), we identified at genome-wide significance (P = 2.7 × 10(-8) to P = 2.3 × 10(-13)) four new PP loci (at 4q12 near CHIC2, 7q22.3 near PIK3CG, 8q24.12 in NOV and 11q24.3 near ADAMTS8), two new MAP loci (3p21.31 in MAP4 and 10q25.3 near ADRB1) and one locus associated with both of these traits (2q24.3 near FIGN) that has also recently been associated with SBP in east Asians. For three of the new PP loci, the estimated effect for SBP was opposite of that for DBP, in contrast to the majority of common SBP- and DBP-associated variants, which show concordant effects on both traits. These findings suggest new genetic pathways underlying blood pressure variation, some of which may differentially influence SBP and DBP

Resveratrol induced neuroprotection is mediated via both estrogen receptor subtypes, Erα and Erβ

Resveratrol, a dietary polyphenol with antioxidant and anti-inflammatory activity, has been shown to provide neuroprotection in models of ischemia. However, the mechanism of action of resveratrol-induced neuroprotection remains unclear. Previous work in our laboratory has provided evidence that acute, systemic administration of resveratrol is neuroprotective in a permanent model of cerebral ischemia, an effect that was blocked when animals received the non-selective estrogen receptor antagonist, ICI, 182,780. The present study was designed to investigate whether the source of neuroprotection afforded by resveratrol action within the cerebral cortex itself is mediated preferentially via selective activation of either α or β estrogen receptor subtype. Intracortical injection of resveratrol (0.1 and 1.0 μM) 10 min prior to 30 min of ischemia followed by 5.5 h of reperfusion significantly reduced infarct volume in the prefrontal cortex. This neuroprotective effect was significantly attenuated when resveratrol injection (1.0 μM) was preceded by injection of a selective estrogen receptor α antagonist, 1,3-bis(4-hydroxyphenyl)-4-methyl-5-[4-(2-piperidinylethoxy)phenol]-1N-pyrozole dihydrochloride (MPP) or a selective estrogen receptor beta (ERβ) antagonist, 4-[2-phenyo-5,7-bis(trifluoromrthyl)pyrazolo(1,5-a)pyrimidin-3-yl]phenol (PHTPP). These results provide evidence for rapidly induced neuroprotection mediated by resveratrol activation of either estrogen receptor subtype within the ischemic cortex of rats

Co-administration of resveratrol and lipoic acid, or their synthetic combination, enhances neuroprotection in a rat model of ischemia/reperfusion.

The present study demonstrates the benefits of combinatorial antioxidant therapy in the treatment of ischemic stroke. Male Sprague-Dawley rats were anaesthetised and the middle cerebral artery (MCA) was occluded for 30 minutes followed by 5.5 hours of reperfusion. Pretreatment with resveratrol 30 minutes prior to MCA occlusion resulted in a significant, dose-dependent decrease in infarct volume (p<0.05) compared to vehicle-treated animals. Neuroprotection was also observed when resveratrol (2 × 10(-3) mg/kg; iv) was administered within 60 minutes following the return of blood flow (reperfusion). Pretreatment with non-neuroprotective doses of resveratrol (2 × 10(-6) mg/kg) and lipoic acid (LA; 0.005 mg/kg) in combination produced significant neuroprotection as well. This neuroprotection was also observed when resveratrol and LA were administered 15 minutes following the onset of MCA occlusion. Subsequently, we synthetically combined resveratrol and LA in both a 1 ∶ 3 (UPEI-200) and 1 ∶ 1 (UPEI-201) ratio, and screened these new chemical entities in both permanent and transient ischemia models. UPEI-200 was ineffective, while UPEI-201 demonstrated significant, dose-dependent neuroprotection. These results demonstrate that combining subthreshold doses of resveratrol and LA prior to ischemia-reperfusion can provide significant neuroprotection likely resulting from concurrent effects on multiple pathways. The additional protection observed in the novel compound UPEI 201 may present opportunities for addressing ischemia-induced damage in patients presenting with transient ischemic episodes

UPEI-300, A Conjugate Of Lipoic Acid And Edaravone, Mediates Neuroprotection In Ischemia/Reperfusion

Edaravone, an electron spin trapper with radical scavenging activity, has been shown to be effective in reducing infarct volume in humans following ischemic stroke. However, concerns of edaravone-induced renal toxicity have limited its clinical adoption. Previous work has demonstrated that edaravone produced significant neuroprotection when injected prior to a period of ischemia and/or reperfusion. The current investigation was designed to determine if a newly synthesized co-drug consisting of lipoic acid and edaravone, named UPEI-300, could produce neuroprotection in in vitro and/or an in vivo rodent model of stroke. UPEI-300 produced dose-dependent neuroprotection in vitro and was subsequently tested in vivo. Male rats were anaesthetized and the middle cerebral artery was occluded for 30 min followed by 5.5 hrs of reperfusion (ischemia/reperfusion; I/R). Pre-administration of UPEI-300 dose-dependently decreased infarct volume. Significant neuroprotection was also observed when UPEI-300 (1.0 mg/kg) was injected during the 30 min period of ischemia as well as up to 60 mins following the start of reperfusion. These results indicate that a co-drug consisting of edaravone and lipoic acid is a potent neuroprotectant, and clinically, the use of such a novel co-drug following an ischemic stroke might maintain neuroprotection while potentially decreasing edaravone associated renal toxicit

All-printed cell counting chambers with on-chip sample preparation for point-of-care CD4 counting

We demonstrate the fabrication of fully printed microfluidic CD4 counting chips with complete on-chip sample preparation and their applicability as a CD4 counting assay using samples from healthy donors and HIV-infected patients. CD4 counting in low-income and resource-limited point-of-care settings is only practical and affordable, if disposable tests can be fabricated at very low cost and all manual sample preparation is avoided, while operation as well as quantification is fully automated and independent of the skills of the operator. Here, we show the successful use of (inkjet) printing methods both to fabricate microfluidic cell counting chambers with controlled heights, and to deposit hydrogel layers with embedded fluorophore-labeled antibodies for on-chip sample preparation and reagent storage. The maturation process of gelatin after deposition prevents antibody wash-off during blood inflow very well, while temperature-controlled dissolution of the matrix ensures complete antibody release for immunostaining after the inflow has stopped. The prevention of antibody wash-off together with the subsequent complete antibody release guarantees a homogeneous fluorescence background, making rapid and accurate CD4 counting possible. We show the successful application of our fully printed CD4 counting chips on samples from healthy donors as well as from HIV-infected patients and find an excellent agreement between results from our method and from the gold standard, flow cytometry, in both cases