450 research outputs found
Effect of lysolecithin on the oxygen uptake of tumour cells, polymorphonuclear leucocytes, lymphocytes and macrophages in vitro.
LYSOLECITHN has been widely studied as a surface-active haemolytic agent (Robinson, 1961) and has been implicated in immune haemolysis (Fischer, 1964), in hypersensitivity reactions (Middleton and Phillips, 1963, 1964), and in the delayed stage of the increase of vascular permeability in inflammation (Cotran and Majno, 1964). Fischer (1964) found that the oxygen uptake (Q02) of tumour cells was reduced by small concentrations of "lysolecithin ", while micro and macrophages responded by an increase Of Q02 and phagocytic activity. We felt that this observation should be confirmed, because it could form the basis of a therapeutic method of increasing the radiosensitivity of tumours by raising the oxygen tension (PO2), and from the theoretical aspect might clarify differences between the cell membranes of tumour and of normal cells. Moreover, Fischer's experiments are open to criticism. His cell suspension was stirred by a moving mercury seal and this could have produced cell damage from mercury poisoning. Also he treated his cell suspensions not with lysolecithin, but with complement plus a specific antibod
Techniques for improving reliability of computers
Modular design techniques improve methods of error detection, diagnosis, and recovery. Theoretical computer (MARCS (Modular Architecture for Reliable Computer Systems)) study deals with postulated and modeled technology indigenous to 1975-1980. Study developments are discussed
Charged Vortices in High Temperature Superconductors Probed by NMR
We report a first experimental evidence that a vortex in the high temperature
superconductors (HTSC) traps a finite electric charge from the high resolution
measurements of the nuclear quadrupole frequencies. In slightly overdoped
YBa_2Cu_3O_7 the vortex is negatively charged by trapping electrons, while in
underdoped YBa_2Cu_4O_8 it is positively charged by expelling electrons. The
sign of the trapped charge is opposite to the sign predicted by the
conventional BCS theory. Moreover, in both materials, the deviation of the
magnitude of the charge from the theory is also significant. These unexpected
features can be attributed to the novel electronic structure of the vortex in
HTSC.Comment: 6 pages, 7 figures, to be published in Phys Rev.
Hairs on the cosmological horizon
We investigate the possibility of having hairs on the cosmological horizon.
The cosmological horizon shares similar properties of black hole horizons in
the aspect of having hairs on the horizons. For those theories admitting haired
black hole solutions, the nontrivial matter fields may reach and extend beyond
the cosmological horizon. For Q-stars and boson stars, the matter fields cannot
reach the cosmological horizon. The no short hair conjecture keeps valid,
despite the asymptotic behavior (de Sitter or anti-de Sitter) of black hole
solutions. We prove the no scalar hair theorem for anti-de Sitter black holes.
Using the Bekenstein's identity method, we also prove the no scalar hair
theorem for the de Sitter space and de Sitter black holes if the scalar
potential is convex.Comment: Revtex, no figures, 16 page
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