5,961 research outputs found
Vibrational Sum-Frequency Generation Spectroscopy of Electrode Surfaces: Studying the Mechanisms of Sustainable Fuel Generation and Utilisation
Transient post-exercise hyper-perspiration of forehead area
Information about sweating responses during exercise recovery is insufficient and mostly controversial. In the present study, particular attention is given to sweating behavior at forehead area immediately after exercise. Simultaneous changes of some underlying factors are also addressed. Eight healthy young males (27.4±0.8 years old) volunteered for the study. They performed a constant work rate exercise (60 rpm at 50% of individual work load for VO2 peak) for 30 min. Sweating from the forehead area was measured by the weight gain of a covered filter paper disk. Simultaneous variations in tympanic temperature, heart rate and mean arterial pressure were obtained. Plasma concentrations for sodium, vasopressin, adrenalin and noradrenalin were also determined. Sweating rate increased up to the first sample taken immediately after exercise cessation (P < 0.05). All other variables measured increased during exercise and with exception of noradrenalin, which was maintained high. Other variables, on the whole, decreased during recovery period. At exercise, off-transient coincident with overshoot in sweating rate, tympanic temperature, noradrenalin and vasopressin were subject to a non significant elevation. These results suggest that, sweating from forehead area is still subject to increase at exercise off-transient. The effects of relevant factors studied here are contradictory and could not justify the increase seen in sweating at off-transient. More studies are required to elucidate the causative factor(s).Key words: Exercise off-transient, recovery, sweating rate, forehead
Evaluating the Impact of Transmission Range on the Performance of VANET
Recently, interest in the field of Vehicular Ad-hoc Networks (VANETs) has grown among research community to improve traffic safety and efficiency on the roads. Despite the many advantages, the transmission range in vehicular network remains one of the major challenges due to the unique characteristics of VANETs such as various communication environments, highly dynamic topology, high node mobility and traffic density. The network would suffer from a broadcast-storm in high vehicular density when a fixed transmission range in VANET is used, while in sparse vehicular density the network could be disconnected frequently. In this paper, we evaluated the impact of different transmission ranges and number of flows formed between vehicles in a highway scenario using AODV as routing protocol. In order to validate the simulation of VANET, traffic and network simulators (SUMO & NS-2) have been used. The performance was evaluated in terms of packet delivery ratio and end-to-end delay. The simulation results have shown that better performance was achieved in term of higher PDR and lower end-to-end delay for less than 500 meters transmission range. On the contrary, the PDR started to decrease and end-to-end delay increased when the transmission range exceeded 500 meters. The performance degraded as the number of flows increased
Fabrication and characterization of oxygen-generating polylactic acid/calcium peroxide composite filaments for bone scaffolds
The latest advancements in bone scaffold technology have introduced novel biomaterials that have the ability to generate oxygen when implanted, improving cell viability and tissue maturation. In this paper, we present a new oxygen-generating polylactic acid (PLA)/calcium peroxide (CPO) composite filament that can be used in 3D printing scaffolds. The composite material was prepared using a wet solution mixing method, followed by drying and hot melting extrusion. The concentration of calcium peroxide in the composite varied from 0% to 9%. The prepared filaments were characterized in terms of the presence of calcium peroxide, the generated oxygen release, porosity, and antibacterial activities. Data obtained from scanning electron microscopy and X-ray diffraction showed that the calcium peroxide remained stable in the composite. The maximum calcium and oxygen release was observed in filaments with a 6% calcium peroxide content. In addition, bacterial inhibition was achieved in samples with a calcium peroxide content of 6% or higher. These results indicate that an optimized PLA filament with a 6% calcium peroxide content holds great promise for improving bone generation through bone cell oxygenation and resistance to bacterial infections
Risk factors of Gestational Diabetes Mellitus Among Saudi Women
Abstract:Objective: The aim of this study was to identify the main risk factors of Gestational Diabetes Mellitus among Saudi women. Methodology: This is a case control laboratory-based study conducted in Wadi Al Dawasir City in Saudi Arabia.600 pregnant women as follows; 300 screened pregnant women as the study group and 300 non screened pregnant women as the control group.Selection Criteria for the screened group: Should be booked at 28 weeks or before that, not known to be diabetic before pregnancy or diagnosed as cases of GDM before 24 weeks. Selection Criteria for the non-screened group: They were not diagnosed before pregnancy as cases of DM or diagnosed during pregnancy as cases of GDM.Screening for GDM: Screening for GDM was a routine using loading dose glucose (LDG) or glucose challenge test (GCT) between 24-28 weeks gestation according to the hospitals protocol. The pregnant women were classified into high risk or low risk according to the following characteristics Results: Risk factors in the screened mothers with positive LDG result was: family history was identified in 56.1% (23/41) of mothers and it was absent in 43.8% (18/41). The next main risk factor among the mothers with positive LDG results was a history of baby weight 4 kg or more and was found in 9.76% (4/41) followed by history of intrauterine fetal death that was detected in 7.32% (3/41). Only one mother 2.44% (1/41) had past history of gestational diabetes mellitus similar to mothers with history of babies with congenital malformation that was detected in 2.44% (1/41) also. Family history was the main risk factor among mothers with positive LDG results as it was found in 56.1%. Within the 20 mothers with significant oral glucose tolerance test (OGTT) results, 80% (16/20) had risk factors and 20% (4/20) had no risk factors. Conclusion: Identifying of risk factors is important for screening for GDM but even women with low risk and no risk factors should be screened for GDM
Detection of elliptical shapes via cross-entropy clustering
The problem of finding elliptical shapes in an image will be considered. We
discuss the solution which uses cross-entropy clustering. The proposed method
allows the search for ellipses with predefined sizes and position in the space.
Moreover, it works well for search of ellipsoids in higher dimensions
Silver influence of physical and thermo luminescence properties on lithium-Strontium-borate LSBO: Ag exposed to cobalt-60 gamma ray
This work investigates the properties of glow curve of lithium Strontium borate doped sliver glass (LSBO: Ag), subjected to Co-60 gamma irradiation. The glass samples were prepared in different compositions based on 15%Li2CO3+2%SrCO3 (83-x) H3BO3 +xAgNO3, where x = 0.001, 0.003, 0.005, 0.007, 0.009 and 0.01 mol% by traditional melting quenching method at temperature 1300 °C for 1 hour. The structural pattern of glass samples has been identified by X-ray diffraction. The XRD pattern shows that the samples are glasses since there is broader peak appearing in the spectral pattern. FESEM images verify the homogeneous and transmitting surface morphology of all samples. Stable glasses with Hurby parameter ~ 0.5 are achieved. EDX spectra determine the accurate elemental compositions in the samples. Physical properties are determined in terms of glass density, molar volume, polar on radius, inter-nuclear distance, and ion concentration. Glass density is found to increase from 2.45 to 2.46 g cm-1 after addition of AgNO3 concentration. The TL intensity at different compositions of lithium borate doped sliver glass after exposed to 50 Gy Co-60 gamma-rays is presented. The results clearly show that the highest TL intensity is found in glass composition of 0.09 mol% of AgNO3
Impact of infection control educational activities on the rates and frequencies of percutaeous injuries (PIS) at a tertiary care hospital in Saudi Arabia
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