818 research outputs found
Nurses\u27 Alumnae Association Bulletin, May 1956
Alumnae Notes
Anesthesiology at Jefferson
Committee Reports
Digest of Alumnae Meetings
Graduation Awards - 1955
Marriages
Necrology
New Arrivals
Physical Advances at Jefferson
President\u27s Message
School of Nursing Report
Thomas A. Shallow Memorial Fun
Nurses\u27 Alumnae Association Bulletin, September 1958
Committee Reports
Digest of Alumnae Meetings
Graduation Awards - 1957
List of Wrong Addresses
Marriages
Necrology
New Arrivals
Physical Advances at Jefferson
President\u27s Message
School of Nursing Repor
Nurses\u27 Alumnae Association Bulletin, December 1968
President\u27s Message
Officers and Committee Chairman
Financial Report
Report to Alumnae Association
Annual Report to Alumnae Association
School of Practical Nursing Report
Student Activities
Nursing Service Staff Association
Letter from Vietnam
Resume of Alumnae Meetings
Ways and Means Report
Social Committee
Building Fund Report
Bulletin Committee Report
Class News
Notice
Nurses\u27 Alumnae Association Bulletin, May 1957
Alumnae Notes
Committee Reports
Digest of Alumnae Meetings
Graduation Awards - 1956
Letter from Hong Kong
Leukemia
Marriages
Necrology
New Arrivals
Physical Advances at Jefferson
President\u27s Message
School of Nursing Report
Two Year Programs in Nursing
White Haven Repor
Experimental evidence of non-Amontons behaviour at a multicontact interface
We report on normal stress field measurements at the multicontact interface
between a rough elastomeric film and a smooth glass sphere under normal load,
using an original MEMS-based stress sensing device. These measurements are
compared to Finite Elements Method calculations with boundary conditions
obeying locally Amontons' rigid-plastic-like friction law with a uniform
friction coefficient. In dry contact conditions, significant deviations are
observed which decrease with increasing load. In lubricated conditions, the
measured profile recovers almost perfectly the predicted profile. These results
are interpreted as a consequence of the finite compliance of the multicontact
interface, a mechanism which is not taken into account in Amontons' law
Thrombin responses in human endothelial cells. Contributions from receptors other than PAR1 include the transactivation of PAR2 by thrombin-cleaved PAR1.
The recent identification of two new thrombin receptors, PAR3 and PAR4, led us to re-examine the basis for endothelial cell responses to thrombin. Human umbilical vein endothelial cells (HUVEC) are known to express PAR1 and the trypsin/tryptase receptor, PAR2. Northern blots detected both of those receptors and, to a lesser extent, PAR3, but PAR4 message was undetectable and there was no response to PAR4 agonist peptides. To determine whether PAR3 or any other receptor contributes to thrombin signaling in HUVEC, PAR1 cleavage was blocked with two selective antibodies and PAR1 activation was inhibited with the antagonist, BMS200261. The antibodies completely inhibited HUVEC responses to thrombin, but BMS200261 was only partly effective, even though separate studies established that the antagonist completely inhibits PAR1 signaling at the concentrations used. Since peptides mimicking the PAR1 tethered ligand domain can also activate PAR2, we asked whether the remaining thrombin response in the presence of the antagonist could be due in part to the intermolecular transactivation of PAR2 by cleaved PAR1. Evidence that transactivation can occur was obtained in COS-7 cells co-expressing PAR2 and a variant of PAR1 that can be cleaved, but not signal. There was a substantial response to thrombin only in cells expressing both receptors. Conversely, in HUVEC, complete blockade of the thrombin response by the PAR1 antagonist occurred only when signaling through PAR2 was also blocked. From these observations we conclude that 1) PAR1 is the predominant thrombin receptor expressed in HUVEC and cleavage of PAR1 is required for endothelial cell responses to thrombin; 2) although PAR3 may be expressed, there is still no evidence that it mediates thrombin responses; 3) PAR4 is not expressed on HUVEC; and 4) transactivation of PAR2 by cleaved PAR1 can contribute to endothelial cell responses to thrombin, particularly when signaling through PAR1 is blocked. Such transactivation may limit the effectiveness of PAR1 antagonists, which compete with the tethered ligand domain rather than preventing PAR1 cleavage
The dynamics of thin vibrated granular layers
We describe a series of experiments and computer simulations on vibrated
granular media in a geometry chosen to eliminate gravitationally induced
settling. The system consists of a collection of identical spherical particles
on a horizontal plate vibrating vertically, with or without a confining lid.
Previously reported results are reviewed, including the observation of
homogeneous, disordered liquid-like states, an instability to a `collapse' of
motionless spheres on a perfect hexagonal lattice, and a fluctuating,
hexagonally ordered state. In the presence of a confining lid we see a variety
of solid phases at high densities and relatively high vibration amplitudes,
several of which are reported for the first time in this article. The phase
behavior of the system is closely related to that observed in confined
hard-sphere colloidal suspensions in equilibrium, but with modifications due to
the effects of the forcing and dissipation. We also review measurements of
velocity distributions, which range from Maxwellian to strongly non-Maxwellian
depending on the experimental parameter values. We describe measurements of
spatial velocity correlations that show a clear dependence on the mechanism of
energy injection. We also report new measurements of the velocity
autocorrelation function in the granular layer and show that increased
inelasticity leads to enhanced particle self-diffusion.Comment: 11 pages, 7 figure
fbl-typing of Staphylococcus lugdunensis: a frontline tool for epidemiological studies
International audienc
- …