101,923 research outputs found
Dip patch clamp currents suggest electrodiffusive transport of the polyelectrolyte DNA through lipid bilayers
No full textSpassova M, Tsoneva I, Petrov AG, Petkova JI, Neumann E. Dip patch clamp currents suggest electrodiffusive transport of the polyelectrolyte DNA through lipid bilayers. Biophysical Chemistry. 1994;52(3):267-274.Planar lipid bilayers formed from monolayers of diphytanoyl lecithin (DPhL) were found to interact with plasmid DNA (5.6 kbp; M(r) = 3.7 X 10(6)) leading to an increase in the conductance of the membrane. The association of DNA with a lipid bilayer greatly facilitates the transport of the small ions of the main salt KCl. The appearance of long-lived current levels, for instance, of 27.6 pA at V-m = +60 mV membrane voltage, where the actual contact (adsorption) is electrophoretically enhanced, suggests a locally conductive DNA/lipid interaction zone where parts of the DNA strand may be transiently inserted in the bilayer, leaving other parts of the DNA probably protruding out from the outer surface of the bilayer. At V-m = -60 mV, where DNA can be electrophoretically moved away from the membrane, the membrane current is practically zero. This current asymmetry is initially also observed at higher voltages, for instance at 200 mV. However, if the voltage sign (V-m = +200 mV) is changed after a transient positive current (approximate to 15 pA) was observed, there is also now (at V-m = -200 mV) a finite negative current at the negative membrane voltage. Thus, it appears that at V-m = +200 mV the adsorbed parts of the polyelectrolyte DNA are not only transiently inserted in, but actually also electrophoretically pulled through, the porous zones onto the other membrane side leaving the bilayer structure basically intact. These data provide direct electric evidence for the electrophoretic transport of a highly charged and hydrated macromolecule, probably together with the associated gegen-ions, through the thin hydrophobic film of the lipid bilayer
Effect of delivery sydtem on the pharmacokinetic and phtotherapeutic properties of bis (methyloxyethylenoxy) silicon-phtalocyanine in tumor-bearing mice.
No full textA Si(N)-phthalocyanine bearing two methoxyethyleneglycol axial ligands bound to the central metal ion (SiPc) has been prepared by chemical synthesis and analyzed for its phototherapeutic activity after administration in a Cremophor or liposome formulation to C57B1/6 mice bearing a subcutaneously transplanted Lewis lung carcinoma (LLC). The maximum drug accumulation in the tumor is found at 24 h after intraperitoneal injection, independent of the delivery system. However, the tumor concentration of SiPc in the Cremophor formulation is about two-fold higher, while the drug concentration in Liver and skin shows similar trends with the two delivery systems. The drug accumulation and retention in the brain is much larger when using Cremophor emulsion. Photodynamic therapy (672 nm, 370 mW m(-2), 360 J cm(-2)) at 24 h after the injection of Cremophor emulsion- or DPPC liposome-formulated SiPc causes a very efficient and similar response for the LLC ( similar to 8 versus 22 mm mean tumor diameter for the control groups at 21 days after phototreatment). These very promising effects, obtained both at higher and lower tumor drug concentrations, clearly demonstrate the potential phototherapeutical activity of the newly synthesized SiPc
Star clusters and associations (Sofia, 1985)
No full textCONTENTS
PREFACE
LIST OF CONTRIBUTORS
HOME INSTITUTES
1. QUASI-EMPIRIC DETERMINATION OF ANGULAR VELOCITY OF GALACTIC
SPIRAL ARMS by B.A.Balázs
2. MASS AND AGE 0ISTRIBUTI0NS OF STARS IN YOUNG OPEN CLUSTERS
by U.C. Ooshi, V.I. Myakutin, A.E. Piskunov and R. Sagar
3. INTEGRAL MAGNITUDES OF STELLAR CLUSTERS AND THE INITIAL MASS
FUNCTION by P .V. Baev and N.M. Spassova
4. INTEGRATED PHOTOMETRIC PARAMETERS OF OPEN CLUSTERS by B.A.
Balázs
5. ON THE ROLE OF FLARE STARS IN YOUNG OPEN CLUSTERS by G. Szé-
csényi-Nagy
6. SOME REMARKS ON THE CLUSTER MEMBER FG VULPECULAE by W. Götz
7. EARLY TYPE STARS IN THE DIRECTION OF THE ASSOCIATION VULPECULA OB4 by T.S. Radoslavova
8. ASSOCIATIONS IN M31 AND M33 by N.S. Nikolov
9. ELLIPTICITY OF 30 GLOBULAR CLUSTERS IN THE ANDROMEDA GALAXY
by A.V. Staneva, N.M. Spassova and P.V. Baev
10. WHAT PERCENTAGE OF THE STARS IS KNOWN IN THE OPEN CLUSTERS
- THE EXAMPLE OF THE PLEIADES by G. Szécsényi-Nagy
11. H-R DIAGRAM OF THE PLEIADES' FLARE STARS by E. S. Parsamian
12. NEW FLARE STARS IN THE REGION OF MON I ASSOCIATION by E.S.
Parsamian, L. Rosino and D.S. Chavushian
13. NONSTABILTY OF STARS IN THE STARFORMING REGION AROUND
GAMMA CYGNI by K. P. Tsvetkova
14. H-ALPHA SURVEY OF GALACTIC NEBULAE NGC 7129 AND IC 5146 by
E. Semkov and M. Tsvetkov
15. CATALOGUE OF THE COORDINATES OF 3600 STARS IN GLOBULAR
CLUSTER M15 FOR THE PERIOD 1896-1910 by N.M. Spassova and
Ch. N. Niko
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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3346: Samuel G. Freedman, author, 2013
No full textPhotograph of author Samuel G. Freedman, at NT Daily Slash meeting in the Mayborn School of Journalism at UNT
Theoretical and experimental investigation of electric field induced second harmonic generation in tetrathia 7 helicenes
No full textIn this paper, we report the first systematic experimental and theoretical investigation of the electric field induced second harmonic response of some tetrathia[7]helicene-based NLOphores. We studied six model compounds carrying the NO2, CH=CHCN, and COCF3 units as accepting groups on both the terminal thiophene positions as well as on the central benzene ring of the helicene backbone. These groups, known to be of medium and medium-strong accepting strength, allow tuning of both the electronic and structural properties of the helicenes studied. This experimental/theoretical study should set a milestone in addressing new structure-properties relationship of this class of nonconventional chiral chromophores able to show second order as well as third order NLO phenomena
The Right to Strike under the United States Constitution: Theory, Practice, and Possible Implications for Canada
No full textAnswering critics of the Canadian Supreme Court's judgment in B.C. Health, the author argues that the Court laid the foundation for a principled and durable doctrine protecting constitutional labour rights, one that goes directly to the heart of the matter — the inequality of workers’ power in the employment relation. In the author’s view, two paths could lead from B.C. Health to the recognition of Charter protec- tion for a right to strike: one that treats the right as an accessory to col- lective bargaining, and one that upholds the right directly on the basis of the Charter values of equality and participation. The author supports the latter approach, contending that constitutional rights should be defined in relation to fundamental values, in a way that is not contingent on time-bound or fact-sensitive assessments about the role of strikes within a particular collective bargaining regime. Although a Charter right to strike may involve the courts in difficult choices about when to defer to legislative policy decisions, and courts may lack the institutional capac- ity to deal effectively with labour law issues, the author points out that judges can look to ILO standards for expert guidance. Noting that the U.S. experience in this area might be of considerable use to Canadians, the author concludes by providing an overview of American case law concerning a constitutional right to strike.Peer reviewe
G-Rank: Unsupervised Continuous Learn-to-Rank for Edge Devices in a P2P Network
No full textRanking algorithms in traditional search engines are powered by enormous training data sets that are meticulously engineered and curated by a centralized entity. Decentralized peer-to-peer (p2p) networks such as torrenting applications and Web3 protocols deliberately eschew centralized databases and computational architectures when designing services and features. As such, robust search-and-rank algorithms designed for such domains must be engineered specifically for decentralized networks, and must be lightweight enough to operate on consumer-grade personal devices such as a smartphone or laptop computer. We introduce G-Rank, an unsupervised ranking algorithm designed exclusively for decentralized networks. We demonstrate that accurate, relevant ranking results can be achieved in fully decentralized networks without any centralized data aggregation, feature engineering, or model training. Furthermore, we show that such results are obtainable with minimal data preprocessing and computational overhead, and can still return highly relevant results even when a user’s device is disconnected from the network. G-Rank is highly modular in design, is not limited to categorical data, and can be implemented in a variety of domains with minimal modification. The results herein show that unsupervised ranking models designed for decentralized p2p networks are not only viable, but worthy of further research.https://github.com/awrgold/G-RankComputer Scienc
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