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R.B. Bapat 《Linear and Multilinear Algebra》1992,32(3):335-337
This section appears from time to time. Contributions are invited, and should be submitted to R C. Thompson, Mathematics Department. University of California, Santa Barbara, CA93106-3080, USA. 相似文献
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Takaaki Tsuchida Gang Zheng Ravindra K. Pandey William R. Potter David A. Bellnier Barbara W. Henderson Harubumi Kato Thomas J. Dougherty 《Photochemistry and photobiology》1997,66(2):224-228
Human serum albumin (HSA) is one of the key components in human blood that may influence drug distribution. As such, it is important to know the affinity of any drug for albumin. Previously, Photofrina mixture of monomeric, dimeric and oligomeric porphyrins, has been subjected to HSA binding studies. However, due to its complex nature, binding studies on Photofrin or other hematoporphyrin derivatives with HSA are inconclusive. In this report, the binding properties of some components (dimers and trimers) of Photofrin® and the relationship between murine photosensitizing efficacy and those binding properties were investigated. The interaction of these porphyrins with HSA was investigated by direct ultrafiltration and fluorescent titration techniques with fluorescent probes such as dansyl-L-proline (DP), which is known to interact selectively with site II on HSA. Porphyrins also were tested for antitumor activity in a mouse model following intravenous administration and exposure to laser light. Together, the results suggest that the photosensitizers that were preferentially bound to site II of HSA were most effective at controlling murine tumor regrowth 相似文献
5.
Anil P. Phadnis Bharati Sinha Bhagbat Nanda Sarita A. Patwardhan J. Venkatesh Rao Ravindra N. Sharma 《Monatshefte für Chemie / Chemical Monthly》1989,120(6-7):581-586
Summary A series of 8-proparglyoxy-3,7-dimethyl-2,6-octadienyl and 8-propargyloxy-3,7-dimethyl-6-octenyl ethers were prepared from 8-hydroxygeranyl and 8-hydroxycitronellyl ethers, respectively. Almost all compounds showed high toxicity toCulex quinquefaciatus larvae at 1 mgl–1 dose level.
Gegen Mücken aktive Produkte, 4. Mitt.: Synthese und biologische Aktivität von 8-Propargyloxy-3,7-dimethyl-2,6-octadienyl/6-octenyl-ethern
Zusammenfassung Eine Reihe von 8-Propargyloxy-3,7-dimethyl-2,6-octadienyl- und 8-propargyloxy-3,7-dimethyl-6-octenyl-ethern wurden aus 8-Hydroxygeranyl- bzw. 8-Hydroxycitronellyl-ethern hergestellt. Fast alle Verbindungen zeigten hoch Toxizität gegenüber Larven vonCulex quinquefaciatus in einer Dosierung von 1 mgl–1.相似文献
6.
Summary Two methods for the determination of ascorbic acid are described. The first employs titration with iodate in presence of cyanide and hydrochloric acid and starch indicator with two end points, corresponding to the formation of iodine after reduction to iodide and conversion of iodine to iodine cyanide respectively. The titration is applied to the indirect determination of vanadium(V). In the second method ascorbic acid is treated with excess ferric solution and the ferrous iron formed is determined colorimetrically by ortho-phenanthroline.
Zusammenfassung Zwei Verfahren zur Ascorbinsäurebestimmung werden beschrieben. Bei dem ersten wird in Gegenwart von KCN und Salzsäure sowie von Stärke als Indicator mit Jodatlösung titriert. Dabei werden zwei Endpunkte erhalten, die der Reduktion von Jodat zu Jodid und damit verbundener Jodbildung bzw. der Umwandlung des Jods in JCN entsprechen. Diese Titration wird auch zur indirekten Bestimmung von Vanadium(V) verwendet. Bei dem zweiten Verfahren wird die Ascorbinsäure mit überschüssiger Eisen(III)-lösung behandelt und das gebildete zweiwertige Eisen colorimetrisch mit o-Phenanthrolin bestimmt.相似文献
7.
Ravindra K. Agrawal 《Journal of Thermal Analysis and Calorimetry》1989,35(3):909-917
In this article, the facts and fictions surrounding the compensation effect is explored. False compensation effect occurs mainly due to: propagation of computational and experimental errors resulting in inaccurate estimates of the Arrhenius parameters; and, the natural compensation between InA andE. Since Arrhenius parameters are sensitive to errors in temperature; the errors due to uncertainty in temperature should be minimized to eliminate false compensation effect. Increasing the experimental temperature range is helpful in minimizing errors due to uncertainty in temperature. A point of concurrence in a plot of Ink and 1/T establishes the occurrence of true compensation effect. True compensation effect has been shown to be a useful tool in chemical research for: identifying the governing reaction mechanism; predicting the effects of various reaction parameters; and, correlating and reducing experimental data.
The author would like to thank the reviewer for his constructive criticisms. 相似文献
Zusammenfassung In dieser Mitteilung werden Fakten und Vorstellungen betreffs des Kompensationseffektes untersucht. Falsche Kompensationseffekte werden hauptsächlich verursacht durch: eine ungenaue Ermittlung der Arrheniusparameter durch die Fortpflanzung von rechnerischen und experimentellen Fehlern sowie dem natürlichen Kompensationseffektes zwischen InA undE. Das Arrheniusparameter gegenüber Fehler im Temperaturwert sehr empfindlich sind, sollten Temperaturungenäuigkeitsfehler zur Vermeidung eines falschen Kompensationseffektes minimalisiert werden. Zur Verminderung der aus der Temperaturungenauigkeit resultierenden Fehler ist es von Nutzen, den Temperaturbereich des Experimentes zu erweitern. Ein wahrer Kompensationseffekt wird durch einen Schnittpunkt in einem Ink-1/T Diagramm angezeigt. Es wird gezeigt, daß der wahre Kompensationseffekt ein nutzvolles Mittel in der chemischen Forschung darstellt: zur Feststellung des dominierenden Reaktionsmechanismus, zur Vorhersage der einflüsse verschiedener Reaktionsparameter und zur Aufarbeitung und Schlußfolgerung von bzw. aus experimentellen Daten.
, . , , lnA E. , , . . Ink-1/T . , , , .
The author would like to thank the reviewer for his constructive criticisms. 相似文献
8.
Summary Procedures have been described for the quantitative determination of thiourea and its methyl derivatives, wherein iodate, permanganate, and ceric sulphate have been used as direct titration solution, either following preoxidation by alkali hypoiodite via (ICI + KOH) or in case of thiourea, by iodine bromide method. Apart from using standard oxidants the methods have an added advantage of a high conversion factor due to oxidation of sulphur to sulphate. Alternative physical methods of detecting the end point is an added feature of these procedures.The authors wish to express their grateful thanks to Dr. S. S. Joshi, D. Sc. (London), for his kind interest in the work. 相似文献
9.
Summary An extension of the two stage titration of ascorbic acid against iodate to the determination of iodine and iodide in a solution is described. A known excess of ascorbic acid, standardized against iodate, is added to a mixed iodine and iodide solution and the excess ascorbic acid together with the total iodide is titrated against the same iodate to the two end points under controlled conditions of acidity. The differential method of calculation gives the amount of iodine and iodide with a blank and a direct titration. The accuracy of the results provides a useful evidence for the mechanism suggested for the two stage titration of ascorbic acid against iodate.Our sincere thanks are due to Professor S. S. Joshi for kind interest in the work. 相似文献
10.
G. S. Deshmukh M. G. Bapat E. Balakrishnan M. C. Eshwar 《Fresenius' Journal of Analytical Chemistry》1959,170(2):381-383
Summary A new procedure for the quantitative determination of Ag, Hg and Pb has been described. This is based on the precipitation, under appropriate conditions of their normal selenites and titrating amperometrically the excess SeIV against NaOBr after filtering the precipitate. In this respect the method is almost analogous to the volumetric determination of the above metals after precipitating their pyridine thiocyanate complexes.Sincere thanks of the authors are due to Prof. S. S. Joshi for kind interest in the work, and to the National Institute of Sciences of India for an award of a fellowship to one of them (M. G. B.). 相似文献