170,608 research outputs found
Aspects of the merrifield peptide synthesis
No full textThis book was written in the context of the daily confrontation with problems in the utilization of polymeric supports for the synthesis of pep tides. Therefore, views and experiences which usually are not mentioned in scientific journals are collected in these pages. The author has deliberately discussed in detail the possible influence of the polymer phase on the varying reaction conditions in the Merrifield synthesis; this aspect is neglected in most publications dealing with peptide synthesis. However, in view of the growing body of information on the chemistry of polymer-supported peptide syntheses, the international readership should regard the author's arguments as open to discussion. I am very much indebted to all of my colleagues with whom I have had the opportunity to cooperate in studying the potential of the Merrifield synthesis. Above all I like to express my gratitude to my teacher, Professor Dr. Theodor Wieland, Heidelberg, for his boundless encouragement and support in my ef forts in the field of peptide synthesis, particularly in its polymer phase bound version. Last but not at least I wish to thank Miss Hildegard Leyden. With in finite patience and great accuracy she typed the manuscript in addition to her daily duties. The work which influenced this book was performed under the auspices of the Max-Planck-Gesellschaft, of which the financial support is gratefully ac knowledged
The Merrifield-Simmons Index and Hosoya Index of C(n,k,λ) Graphs
No full textThe Merrifield-Simmons index i(G) of a graph G is defined as the number of subsets of the vertex set, in which any two vertices are nonadjacent, that is, the number of independent vertex sets of G The Hosoya index z(G) of a graph G is defined as the total number of independent edge subsets, that is, the total number of its matchings. By C(n,k,λ) we denote the set of graphs with n vertices, k cycles, the length of every cycle is λ, and all the edges not on the cycles are pendant edges which are attached to the same vertex. In this paper, we investigate the Merrifield-Simmons index i(G) and the Hosoya index z(G) for a graph G in C(n,k,λ)
Cacti with the maximum Merrifield–Simmons index and given number of cut edges
No full textAbstractThe Merrifield–Simmons index of a graph G, denoted by i(G), is defined to be the total number of its independent sets, including the empty set. A graph G is called a cactus if each block of G is either an edge or a cycle. Denote by C(n,k) the set of connected cacti possessing n vertices and k cut edges. In this work, we shall characterize the cacti with the maximum Merrifield–Simmons index among all graphs in C(n,k) for all possible values of k
New solid-supported reagents (SSRs) for selective acylation of amines
No full textThe pyrimidine linker (4) was prepared by solid phase synthesis starting from Merrifield resin. Acylation of 4 with different acyl chlorides gave polymerbound 4-acyloxypyrimidines (2a-c), which proved to be useful solid-supported reagents for the selective acylation of amines. Their use in solution combinatorial chemistry has been also envisaged. (author abst.
Public debt sustainability: international perspectives/ edited by Barry W. Poulson, John Merrifield, and Steve H. Hanke.
No full textIncludes bibliographical references and index."This book examines the issue of debt sustainability from an international perspective, with reference to European countries, emerging nations, and the United States"--Part I: Rules-based fiscal policy in the United States. -- Organizing congress for budget reforms / Kurt Couchman -- Debt fatigue and the climacteric in U.S. economic growth / John Merrifield and Barry Poulson -- Part II: rules-based fiscal policy in Europe. -- Preparing for the next crisis: lessons from the successful Swedish fiscal framework / Fredrik N. G. Andersson and Lars Jonung -- The Swiss federal debt brake and its unbudgeted surpluses /Vera Z. Eichenauer and Jan-Egbert Sturm -- The German "debt brake": success factors and challenges -- Lars P. Feld and Wolf H. Reuter -Part III: rules-based fiscal and monetary policy in emerging nations. -- A money doctor's reflections on currency reforms and hard budget constraints /Steve H. Hanke -- Fiscal rules and public debt: an emerging market perspective / Pablo E. Guidott -- Populist economic thought: the legacy of Juan Domingo Perón -- Carlos Newland and Emilio Ocampo -- Part IV: is non-conventional monetary policy supporting or undermining fiscal stabilization policy? -- Monetary policy and the worsening U.S. debt crisis / Norbert j. Michel -- The Federal Reserve and the debt crises / Thomas r. Saving -- The high costs of fiscal and monetary anomie: Argentina since 1945 / Emilio Ocampo -- Part V: The ultimate challenge for fiscal sustainability entitlement reform. -- The failure to establish effective rules for financing U.S. federal entitlement programs / Charles Paul Blahous -- Fiscal rules for Social Security and Medicare: would accrual accounting help? / James C. Capretta.1 online resource (unpaged)
Merrifield resin-assisted routes to second-generation catalysts for olefin metathesis
No full textPhosphine-scavenging Merrifield resins can significantly facilitate the synthesis of highly active Ru metathesis catalysts, including the second-generation Grubbs, Hoveyda, and indenylidene catalysts (GII, HII, InII).</p
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Mitomycin C in highly myopic eyes - Author reply
No full textOphthalmology. 2005 Feb;112(2):208-18; discussion 219.
Mitomycin C modulation of corneal wound healing after photorefractive keratectomy in highly myopic eyes.
Gambato C, Ghirlando A, Moretto E, Busato F, Midena E.
SourceRefractive Surgery Service and Antimetabolite Therapy Research Unit, Department of Ophthalmology, University of Padova, Padova, Italy.
Abstract
PURPOSE: To evaluate the role of topical mitomycin C in corneal wound healing (CWH) after photorefractive keratectomy (PRK) in highly myopic eyes.
DESIGN: Prospective, double-masked, randomized clinical trial.
PARTICIPANTS: Seventy-two eyes of 36 patients affected by high (>7 diopters) myopia.
METHODS: In each patient, one eye was randomly assigned to PRK with intraoperative topical 0.02% mitomycin C application, and the fellow eye was treated with a placebo. Postoperatively, mitomycin C-treated eyes received artificial tears (3 times daily, tapered in 3 months), whereas the fellow eye was treated with fluorometholone sodium 2% and artificial tears (3 times daily, tapered in 3 months).
MAIN OUTCOME MEASURES: Uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA), contrast sensitivity, manifest refraction, and biomicroscopy. Contrast sensitivity was determined using the Pelli-Robson chart. Corneal confocal microscopy documented CWH.
RESULTS: Mean follow-up was 18 months (range, 12-36). No side effects or toxic effects were documented. At 12-month follow-up examination, UCVAs (logarithm of the minimum angle of resolution) were 0.4+/-0.48 and 0.5+/-0.53 (P = .03) in mitomycin C-treated eyes and corticosteroid-treated eyes, respectively. At 1 year, corneal haze developed in 20% of corticosteroid-treated eyes, versus 0% of mitomycin C-treated eyes. At 12, 24, and 36 months, corneal confocal microscopy showed activated keratocytes and extracellular matrix significantly more evident in untreated eyes (Ps = 0.004, 0.024, and 0.046, respectively).
CONCLUSION: Topical intraoperative application of 0.02% mitomycin C can reduce haze formation in highly myopic eyes undergoing PRK.
Comment in
Ophthalmology. 2006 Feb;113(2):357; author reply 357-8
An alternative mechanism of clathrin-coated pit closure revealed by ion conductance microscopy
No full textCurrent knowledge of the structural changes taking place during clathrin-mediated endocytosis is largely based on electron microscopy images of fixed preparations and x-ray crystallography data of purified proteins. In this paper, we describe a study of clathrin-coated pit dynamics in living cells using ion conductance microscopy to directly image the changes in pit shape, combined with simultaneous confocal microscopy to follow molecule-specific fluorescence. We find that 70% of pits closed with the formation of a protrusion that grew on one side of the pit, covered the entire pit, and then disappeared together with pit-associated clathrin-enhanced green fluorescent protein (EGFP) and actin-binding protein-EGFP (Abp1-EGFP) fluorescence. This was in contrast to conventionally closing pits that closed and cleaved from flat membrane sheets and lacked accompanying Abp1-EGFP fluorescence. Scission of both types of pits was found to be dynamin-2 dependent. This technique now enables direct spatial and temporal correlation between functional molecule-specific fluorescence and structural information to follow key biological processes at cell surfaces
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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