Search results for "CELLULAR"
showing 10 items of 6449 documents
Eine Bemerkung zur Frage der Verwendung Lagrangescher Koordinaten in der Physik nichtlinearer Schwingungen
1958
For the Cartesian coordinates of the elements of a vibrating string, which are introduced as functions of time and a parameter (similar to the Lagrangean method in hydrodynamics), a general, non-linear system of differential equations is offered. The behaviour of the freely vibrating string corresponding to this system agrees, approximately, with the behaviour of a string put in motion in a certain way, which string, if moving freely, would act according to the linear differential equation of the elementary theory.
(+)-α-Pinene in the defensive secretion ofNasutitermes princeps (Isoptera, Termitidae)
1990
The frontal secretion ofNasutitermes princeps consists of 89% diterpenes and 11% monoterpenes. In the samples studied, (+)-α-pinene, whose optical purity reaches 99.5%, accounts for more than 80% of the monoterpenic content.
P-glycoprotein and its inhibition in tumors by phytochemicals derived from Chinese herbs
2011
P-glycoprotein belongs to the family of ATP-binding cassette (ABC) transporters. It functions in cellular detoxification, pumping a wide range of xenobiotic compounds, including anticancer drugs out of the cell. In cancerous cells, P-glycoprotein confers resistance to a broad spectrum of anticancer agents, a phenomenon termed multidrug resistance. An attractive strategy for overcoming multidrug resistance is to block the transport function of P-glycoprotein and thus increase intracellular concentrations of anticancer drugs to lethal levels. Efforts to identify P-glycoprotein inhibitors have led to numerous candidates, none of which have passed clinical trials with cancer patients due to the…
Prostaglandin production by human polymorphnuclear leucocytes during phagocytosis in vitro.
1977
Human polymorphonuclear leukocytes were found to be able to synthetize and release substantial amounts of PGE2' when stimulated by a phagocytic stimulus such as zymosan particles coated with complement. Hydrocortisone, at a concentration of 10(-5) M, which proved to be effective in other biological systems, failed to inhibit phagocytosis and PG release.
A method for the incorporation of radioactive isotopes in the sea urchin egg.
1957
Con la iniezione di 10–20µc di Metionina-S35 nella cavita celomatica di femmine adulte diParacentrotus lividus si ottiene una rapida ed efficiente incorporazione dell'isotopo nelle uova. Si discutono i vantaggi del metodo rispetto a quello attualmente in uso.
Hörempfindungen im Ultraschallgebiet
1950
Tones between 15 and 200 kcycles are audible when applied by bone-conduction. The resulting sensation is to be observed not over the whole surface of the head and neck, but only over many points, of which early 60 have been investigated in cases of normally hearing persons of both sexes and middle age. The sensation is that of a very high tone and does not change according to frequency. The highest limit of hearing may lie near 200 kcycles. The reasons are discussed why hearing in this “ultrasonic” range seems to be a real one, which can be understood by observations ofGalambos andDavis on single nerve fiber-preparations.
Antigen-distribution in rat liver mitochondria.
1962
I mitocondri di fegato di ratto possiedono almeno tre gruppi di antigeni, dei quali uno e esclusivamente legato alle membrane mitocondriali, uno e presente nella frazione solubile in 0,3% desossicolato di sodio ed un altro, che, sebbene principalmente localizzato nelle membrane, e anche dimostrabile nella frazione desossicolato solubile.
Effects of N2, O2'-dibutyril cyclic GMP on the nucleoside phosphotransferase activity of the retina of the chick embryos.
1977
In the retina of the chick embryo, 2 different forms of nucleoside phosphotransferase take part in the phosphorylation of thymidine. One is an unstable form with higher molecular weight. The other with lower m. wt is a stable form. This paper shows that N2, O2′-dibutyril cyclic GMP causes a marked decrement of the activity of the unstable nucleoside phosphotransferase.
ATPase in the normal and dystrophic developing retina of the rat
1966
Viene descritto un aumento significativo dell'attivita specifica dell'ATPasi (attivita/mg proteine) durante lo sviluppo post-natale della retina in ratti normali ed in ratti con retinite pigmentosa ereditaria. Il rapporto tra attivita ATPasica in presenza di Mg++-Na+-K+ ed attivita ATPasica in presenza di Mg++ non varia nella retina normale, mentre esso va incontro ad un precoce declino durante lo sviluppo della retina distrofica. Il significato di questi dati e discusso molto brevemente.
Eubotriol and eubol, new diterpenes fromSideritis euboea
1977
2 new diterpenes Eubotriol (ent-kaur-16-ene-7α, 15β, 18triol) (I), and eubol (ent-kaur-16-ene-7α-acetoxy-15β, 18 diol) (II) have been isolated from Sideritis euboea Helder.