ZIB

Treffer pro Seite

Treffer 1 - 2 | 2 Treffer

Sortierung

Digitale Medien

Studies on alpha adrenoceptors in guinea-pig peripheral lung strips (1987)

Turner, A. J. ; Seale, J. P. ; Black, J. L. ; [weitere]

Springer

Naunyn-Schmiedeberg's archives of pharmacology 335 (1987), S. 269-273

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 1432-1912

Schlagwort(e): Guinea-pig lung ; Noradrenaline ; Catecholamine uptake inhibitors ; α-Adrenoceptors ; Phentolamine ; Prazosin

Quelle: Springer Online Journal Archives 1860-2000

Thema: Medizin

Notizen: Summary Contractile responses of guinea-pig peripheral lung strips to noradrenaline were determined in the presence of propranolol (2.5 × 10−6 mol/l). All strips (n = 44) contracted to noradrenaline and a geometric mean EC50 of 1.4 × 10−6 mol/l (1.1 × 10−6 mol/l, 1.8 x 10−6 mol/l 95% confidence limits) was obtained. Contractions were antagonised by phentolamine (5 × 10−7−10−5 mol/l) and by prazosin (10∞−10−7 mol/l). Dose-ratios (DR) were calculated and log (DR-1) was plotted against log concentration of antagonist to yield slopes (± SE) of 0.84 ± 0.14 and 0.73 ± 0.22 respectively which were not significantly different from unity. A pA2 value (± SE) of 6.7 ± 0.2 was obtained for phentolamine and 7.5 ± 0.1 for prazosin. Yohimbine (10−7−10−5 mol/l) did not significantly affect the maximal tension generated or the EC50 values for noradrenaline. These results suggest that α1 adrenoceptors are mediating the contractile responses to noradrenaline. In the presence of cocaine (10−5 mol/l, n=18), normetanephrine (2 × 10−5 mol/l, n = 15), hydrocortisone (2.5 × 10−5 mol/l, n = 15) and normetanephrine (2 × 10−5-5 mol/l) plus cocaine (10−6 5 mol/l, n=15) pA2 values for phentolamine of 6.9, 6.7, 6.6, and 6.3 respectively were obtained. Since these pA2 values are not significantly different from 6.7, it is unlikely that this original pA2 value, which is lower than values obtained with phentolamine at α-adrenoceptors in other tissues, may be explained by neuronal or extraneuronal uptake of noradrenaline. A possible explanation may be that more than one population of α-adrenoceptors contribute to changes in tension in peripheral lung strips.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00172795

Permalink

Bibliothek	Standort	Signatur	Band/Heft/Jahr	Verfügbarkeit

Andere fanden auch interessant ...

Artikel (Nationallizenzen)

Volltext

Digitale Medien

Epoxy resins for deep UV lithography (1989)

Stewart, K. J. ; Hatzakis, M. ; Shaw, J. M.

Stamford, Conn. [u.a.] : Wiley-Blackwell

Polymer Engineering and Science 29 (1989), S. 907-910

zur Merkliste hinzufügen auf der Merkliste

Details

ISSN: 0032-3888

Schlagwort(e): Chemistry ; Chemical Engineering

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Maschinenbau , Physik

Notizen: A negative resist based upon photo-acid initiated cationic polymerization of an epoxy resin (1, 2) was reported in the early eighties with the advent of onium salts (3-5). An efficient acid generating onium salt, triphenylsulfonium hexafluoroantimonate (6), absorbs light in the deep UV producing acid upon direct photolysis in this region of the spectrum. The resin component of such a negative resist system must be optically transparent over the exposure wavelengths to obtain vertical image profiles. Another difficulty often encountered with crosslinking negative resists is swelling of the crosslinked matrix during development with organic solvents. This swelling manifests itself in distorted images and/or complete adhesion loss, especially when submicron features are involved. Our goal has been to address these problems and develop an organic developable deep UV resist capable of providing submicron images. Optically transparent commercial resins, styrene-allyl alcohol copolymers, have been converted to glycidyl ethers, thereby providing cationically polymerizable functionalities. Careful choice of the resin was made to obtain reactive ion etch resistance, thermal stability, good adhesion, and coating properties. The synthetic procedure and characterization of the epoxy resin will be presented. The effect of the molecular weight distribution upon swelling during development and general solubility properties also will be discussed. Resist formulations exhibited sensitivities of 19 to 30 mJ/cm2 on a Perkin Elmer 500 in the deep UV (UV2) mode. The electron beam sensitivity is 3 to 5 μC/cm2 at 20 KeV. Submicron images have been generated in both optical and electron beam lithography.

Zusätzliches Material: 5 Ill.