نتایج جستجو برای: surface changes
تعداد نتایج: 1453740 فیلتر نتایج به سال:
Microfabricated cantilever sensors were used to measure the surface stress induced by protein adsorption onto a gold surface. Two proteins, immoglobulin G (IgG) and albumin (BSA), were studied. The change of surface stress upon adsorption of IgG was found to be compressive, whereas that of BSA was tensile. This difference is elucidated in terms of protein deformation and packing. Most stress ch...
The purpose of this study was to determine the effects of a particular psychological stress, exposure to an open-field, on plasma IL-6 activity in rats. Plasma IL-6 activity was 40.6 +/- 7.2 units/ml in control rats, 105 +/- 6.8 units/ml after 30 minutes exposure to an open-field, and 221 +/- 17 units/ml after 60 minutes of exposure (p = 0.0003). There was a positive correlation (r = .71, p = 0...
OBJECTIVES Many analytical methods are not very sensitive to change because of the difficulty of distinguishing short-term fluctuation from the developmental change of primary interest. The current project investigated one possible solution to this problem in the form of a measurement-burst design in which research participants perform several versions of each test at each measurement occasion....
General lifestyle activities were examined as a predictor of current cognition and cognitive change over a 6-year interval in older adults. Participants were drawn from a population-based longitudinal study, and they completed the Adelaide Activities Profile and a battery of tests measuring cognition and sensory functioning. Hierarchical regression analyses revealed that, after sensory function...
A moisture- electrical - temperature (MET) test is proposed to evaluate the outdoor reliability of high power blue LEDs, with and without phosphor, and to understand the degradation physics of LEDs under the environment of combined humidity, temperature and electrical stresses. The blue LEDs with phosphor will be the high power white LEDs. Scanning acoustic microscopy is used to examine the res...
It has been suggested that work characteristics, such as mental demands, job control, and occupational complexity, are prospectively related to cognitive function. However, current evidence on links between psychosocial working conditions and cognitive change over time is inconsistent. In this study, we applied the effort-reward imbalance model that allows to build on previous research on menta...
It is proposed that personality (conceptualized in terms of motives and psychological resources) changes normatively not only from young adulthood to middle age but also within middle age and that these changes take place in relation to social and biosocial change over the same period. Data from 123 women studied at ages 27, 43, 52, and 61 largely supported hypotheses about change in social rol...
BACKGROUND A Vygotskian framework links cognitive change to collaborative interaction with a more competent partner whereas a Piagetian perspective supports the view that cognitive conflict arising from peer interaction leads to cognitive change. AIMS The study investigated the effect of collaborative learning on children's problem-solving ability and whether differences in knowledge status o...
Research on age-related cognitive change traditionally focuses on either development or aging, where development ends with adulthood and aging begins around 55 years. This approach ignores age-related changes during the 35 years in-between, implying that this period is uninformative. Here we investigated face recognition as an ability that may mature late relative to other abilities. Using data...
The objective of our study was to establish whether rectal temperature recordings in humans could be replaced by a non-invasive skin temperature sensor combined with a heat flux sensor (Double Sensor) located at the forehead to monitor core body temperature changes due to circadian rhythms. Rectal and Double Sensor data were collected continuously for 24h in seven men undertaking strict head-do...
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