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Biomedical subjects

V Sahni

Publications and source records attributed to V Sahni.

At least 19 recordsLinked to original sources
PubMed2000

Reconstructing the cosmic equation of state from supernova distances.

Observations of high-redshift supernovae indicate that the Universe is accelerating. Here we present a model-independent method for estimating the form of the potential V(phi) of the scalar field driving this acceleration, and the associated equation of state w(phi). Our method is based on a versatile analytical form for the luminosity distance D(L), optimized to fit observed distances to distant supernovae and differentiated to yield V(straight phi) and w(straight phi). Our results favor w(phi) approximately -1 at the present epoch, steadily increasing with redshift. A cosmological constant is consistent with our results.

Astronomy↗
PubMed1992

The potent irritancy of the daphnane orthoester, resiniferatoxin, exhibits features of a mixed aetiology.

Resiniferatoxin-induced erythema of mouse ear was shown to possess characteristics of both a phorbol ester-mediated response and that induced by the neurogenic irritant, capsaicin. Whereas the response to the phorbol ester, sapintoxin D, was delayed and prolonged, and was augmented by capsaicin pretreatment, the response to resiniferatoxin was biphasic, with the early phase being antagonized by capsaicin desensitization. However, resiniferatoxin was most potent in inducing a delayed erythema which, unlike the capsaicin response, was sensitive to inhibition by low dose hydrocortisone treatment, but not to chronic capsaicin desensitization. It is concluded that the erythema response to resiniferatoxin has a mixed aetiology, which may explain the unique potency of this toxin.

Animals↗