Search results for "MOBILITY"
showing 10 items of 922 documents
Mobility decline in old age.
2012
Mobility is important for community independence. With increasing age, underlying pathologies, genetic vulnerabilities, physiological and sensory impairments, and environmental barriers increase the risk for mobility decline. Understanding how mobility declines is paramount to finding ways to promote mobility in old age. peerReviewed
Contribution of musculoskeletal pain to postural balance in community-dwelling people aged 75 years and older.
2010
Background. Balance is among the most important prerequisites for safe and independent mobility. Whether musculoskeletal pain is related to standing balance impairment has received limited attention. The aim of this study was to examine the association of musculoskeletal pain with the control of balance in older people. Methods. A total of 605 participants aged 75 years and older (mean age 80.4, 71 % women) were interviewed about presence and severity of musculoskeletal pain. Balance was measured by a force platform, and impaired balance was defined as a high sway velocity moment or inability to maintain semitandem standing. Results. Musculoskeletal pain was reported by 48% of the participa…
Impact of contact resistance on the electrical properties of MoS
2016
Molybdenum disulphide (MoS2) is currently regarded as a promising material for the next generation of electronic and optoelectronic devices. However, several issues need to be addressed to fully exploit its potential for field effect transistor (FET) applications. In this context, the contact resistance, R C, associated with the Schottky barrier between source/drain metals and MoS2 currently represents one of the main limiting factors for suitable device performance. Furthermore, to gain a deeper understanding of MoS2 FETs under practical operating conditions, it is necessary to investigate the temperature dependence of the main electrical parameters, such as the field effect mobility (μ) a…
Redox signaling in acute pancreatitis
2015
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On th…
Cycloamphilectenes, a new type of potent marine diterpenes: inhibition of nitric oxide production in murine macrophages.
2003
The inhibitory effect of a series of 6 cycloamphilectenes, novel marine diterpenes based on amphilectene skeletons and isolated from the Vanuatu sponge Axinella sp., on NO, PGE(2) and TNFalpha production in murine peritoneal macrophages was studied. These compounds reduced potently nitric oxide production in a concentration-dependent manner with IC(50) values in the submicromolar range (0.1-4.3 microM). Studies on intact cells and Western blot analysis showed that the more potent cycloamphilectenes reduced the expression of inducible nitric oxide synthase without affecting cyclo-oxygenase-2 expression. Among them cycloamphilectene 2, the unique compound bearing an exocyclic methylene group,…
Peptidases specific for proline-containing peptides and their unusual peptide-dependent regulation in Oenococcus oeni
2009
International audience; Growth of the lactic acid bacterium (LAB) Oenococcus oeni, which is involved in malolactic fermentation during the winemaking process, is stimulated by peptides originating from yeast. In this study, we investigated the impact of peptides on O. oeni growth, peptidase activity and the expression of genes encoding the studied peptidases. Low levels of PepN activity and very high levels of PepI activity were observed in O. oeni, whereas levels of PepX activity were intermediate. The level of biosynthesis of these O. oeni peptidases was shown to depend on peptides present in the culture medium. These results were confirmed by transcriptional analyses of putative pep gene…
Temperature Dependence of pHEMT-Based LNA Performance for VSAT Applications
1994
From a complete characterization in terms of noise and scattering parameters carried out at room temperature in the 8-16 GHz frequency range, the noisy small-signal model of a pseudomorphic HEMT series has been extracted. The transistor scattering parameters have been subsequently measured at lower temperatures (down to -50 °C) by placing the device text fixture in a thermo-controlled chamber. An accurate noisy model has then been extracted by determining the circuit element values at the different temperatures. The trade-off performance of a pHemt-based LNA for VSAT receiver system applications has been investigated vs. frequency and temperature.
Typical Aspects of the Microwave Noise Performance of HEMTs at Decreasing Temperatures
1996
In analog signal processing at microwave frequencies the noise performance of active devices is of fundamental importance for the accurate design of low-noise amplifiers. To this aim, the determination of the four noise parameters F O , Γ O (complex variable) and Rn has to be accomplished together with the usual scattering parameter measurements vs. frequency. In addition, the dependence of the device performance vs. temperature is of interest for circuit applications characterized by harsh environmental conditions. In this work the noise behavior of high electron mobility transistors has been investigated by means of measurements and modeling in the 2-18 GHz frequency range and as a functi…
Fast and efficient procedures for determining the microwave noise parameters of HEMT's at decreasing temperatures
1998
Noise parameters are an electrical representation of the noise performance of transistors which is widely used in reliability studies as well as in the design of low-noise microwave amplifiers. Such parameters are usually determined by employing a complex indirect (standard) procedure based on multiple noise figure measurements and appropriate data processing techniques. We report here two altemative and rapid methods used to perform the complete noise characterization of HEMT's at decreasing temperatures over the 6 to 18 GHz frequency range. The results show a very satisfactory agreement.among the different procedures thus assessing the inherent consistency of the global approach to the pr…
Dislocation mobility study of heavy ion induced track damage in LiF crystals
2008
Track damage created in LiF crystals by swift U, Kr, Xe and Ni ions with a specific energy of 11.1 MeV/u was studied using dislocation mobility measurements, track etching, SEM, AFM and optical microscopy. The results demonstrate continuity of etching of U tracks while discontinuities of etching are observed in the case of Xe ions. The relationship between the track structure and dislocation mobility in irradiated crystals is discussed. The dislocation mobility technique can serve as a highly sensitive method for track core damage studies.