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91.
Abstract— Balb/c mice bearing a transplantedMS–2 fibrosarcoma have been injected with 2 mg kg-1 hematoporphyrin either dissolved in phosphate-buffered saline (Hp-aq), or incorporated into unilamellar liposomes of dipalmitoyl-phosphatidylcholine (Hp-lip), or precomplexed with low density lipoproteins (Hp-LDL). At 24 h after injection, the mice received 150 J cm-2 of600–680 nm light irradiation. Electron microscopic studies performed on tumor tissues taken from mice sacrificed at different times after the phototreatment showed that, in the presence of Hp-aq. tumor necrosis is largely the consequence of vascular damage. On the other hand, in the presence of Hp-lip and Hp-LDL, the response of the tumor to the phototreatment occurs at a faster rate and is mainly determined by direct damage of neoplastic cells. These findings are correlated with the different distribution of the various hematoporphyrin forms (Hp-aq, Hp-lip, Hp-LDL) among the serum proteins and the modalities of hematoporphyrin delivery to tissues by the possible carriers. 相似文献
92.
93.
Summary Suitable measures of plastic and of total deflections developed over a time interval by an elastic-perfectly plastic continuous structure in the presence of significant inertia and viscous forces, is shown to be bounded from above by a quantity which can be evaluated merely on the basis of a linear-elastic dynamic analysis. The results achieved are extended to elastic-workhardening bodies under the assumption of piecewiselinear yield surfaces. The practical use of the present results is checked comparatively by a simple example.
Paper accepted for presentation at the Second Bulgarian Congress of Theoretical and Applied Mechanics, Varna, 8–14 October 1973. 相似文献
Sommario Si mostra come misure opportunamente definite delle deformazioni plastiche o totali che si sviluppano in un certo intervallo di tempo in un continuo perfettamente elastoplastico soggetto ad azioni dinamiche, siano delimitate superiormente da quantità valutabili attraverso un'analisi dinamica in campo elastico-lineare. I risultati ottenuti vengono estesi a materiali incrudenti, mediante linearizzazione a tratti della superficie di snervamento. La loro utilizzabilità pratica è illustrata da unsemplice esempio.
Paper accepted for presentation at the Second Bulgarian Congress of Theoretical and Applied Mechanics, Varna, 8–14 October 1973. 相似文献
94.
Giulio Ceccarelli Giancarlo Berti Giorgio Lippi Bruno Macchia 《Magnetic resonance in chemistry : MRC》1970,2(4):379-388
NMR spectra of several styrene, stilbene and stilbazole oxides have been determined, and chemical shifts and coupling constants have been correlated with cis-and trans-configurations. Assignments have been made for all protons, and double resonance technique and 13C? H coupling constants have been used in some particular cases. An explanation is proposed for the observation that chemical shifts of oxirane protons are higher for cis than for trans isomers. 相似文献
95.
Giulio Supino 《Meccanica》1970,5(1):42-53
Summary Propagation of the tide in a lagoon is studied, taking into account expansion of the waves in the shallows, but otherwise utilizing the classic theory of first approximation. The time lag in propagation and the attenuation of the wave may thus be determined.
Sommario Si studia la propagazione della marea in una laguna, tenendo conto della espansione delle onde sui bassifondi, ma per il resto, utilizzando la teoria classica di prima approssimazione. Si giunge così a determinare il ritardo nella propagazione e l'attenuazione dell'onda.相似文献
96.
We show that pointlike defect model of glasses cannot explain the thermodynamic properties of glass formers, as for example, the excess specific heat close to the glass transition, contrary to the claim of Garrahan and Chandler [Proc. Natl. Acad. Sci. U.S.A. 100, 9710 (2003)]. More general models and approaches in terms of extended defects are also discussed. 相似文献
97.
Giulio Mattei 《Annali di Matematica Pura ed Applicata》1968,80(1):327-341
Sunto Si determinano delle classi di soluzioni delle equazioni descriventi nell'ambito della teoria di Chew, Goldberger e Low un
plasma anisotropo con condizioni al contorno relative ai due casi: (a) dominio cilindrico indefinito, (b) dominio cilindrico
finito. Si danno poi le condizioni necessarie e sufficienti per la stabilità delle soluzioni trovate.
Lavoro eseguito nell'ambito della attività dei Gruppi di Ricerca Matematica del C.N.R. presso l'Istituto di Matematiche Applicate
della Facoltà di Ingegneria della Università di Pisa. 相似文献
98.
The use of correlation function methods to predict the onset of chaotic motion in conservative Hamiltonian systems is critically examined. It is shown that microcanonical correlation functions do not, in general, provide a convenient criterion to distinguish between stable and unstable motions. 相似文献
99.
Weissker HC Serrano J Huotari S Bruneval F Sottile F Monaco G Krisch M Olevano V Reining L 《Physical review letters》2006,97(23):237602
We present an investigation of the dynamic structure factor and of the dielectric function epsilonM(Q,omega) of the prototypical semiconductor silicon for finite momentum transfer, combining inelastic x-ray scattering experiments and ab initio calculations. In contrast with optical spectra, for finite momentum transfer time-dependent density-functional theory in the adiabatic local-density approximation together with lifetime broadening describes the physics of valence excitations correctly. Major structures in the spectra, governed by short-range crystal and exchange-correlation local-field effects, are strongly influenced by a mixing of transitions of positive and negative energies, in striking difference to spectra for vanishing momentum transfer. This mixing gives rise to a pronounced Fano asymmetry. 相似文献
100.
Caracciolo G Pozzi D Caminiti R Amenitsch H 《The journal of physical chemistry. B》2006,110(42):20829-20835
The mechanism of formation of multicomponent lipoplexes was investigated by means of synchrotron Small-Angle X-ray Diffraction (SAXD). Mixed lipid dispersions were prepared by mixing different populations of binary cationic liposomes. When adding DNA to mixed lipid dispersions, multicomponent lipoplexes spontaneously formed exhibiting structural properties, i.e., membrane thickness, surface charge density, and one-dimensional DNA packing density, intermediate between those of binary lipoplexes. These results suggested that DNA lets liposomes come into contact and fuse and that a complete lipid mixing at the molecular level occurs. The equilibrium structure of multicomponent lipoplexes was found to be unique and did not depend on the number and kind of populations composing lipid dispersion but only on the lipid species involved and on their relative molar ratio. According to recent theoretical models we identified two-dimensional lipid mixing entropy as the key factor regulating the existence of only multicomponent lipoplexes with ideally mixed lipid species. 相似文献