Abstract:
:Strong, short-ranged positional correlations involving counterions can induce a net attractive force between negatively charged strands of DNA and lead to the formation of ion pairs in dilute ionic solutions. However, the long range of the Coulomb interactions impedes the development of a simple local picture. We address this general problem by mapping the properties of a nonuniform system with Coulomb interactions onto those of a simpler system with short-ranged intermolecular interactions in an effective external field that accounts for the averaged effects of appropriately chosen long-ranged and slowly varying components of the Coulomb interactions. The remaining short-ranged components combine with the other molecular core interactions and strongly affect pair correlations in dense or strongly coupled systems. We show that pair correlation functions in the effective short-ranged system closely resemble those in the uniform primitive model of ionic solutions and illustrate the formation of ion pairs and clusters at low densities. The theory accurately describes detailed features of the effective attraction between two equally charged walls at strong coupling and intermediate separations of the walls. Analytical results for the minimal coupling strength needed to get any attraction and for the separation at which the attractive force is a maximum are presented.
journal_name
Proc Natl Acad Sci U S Aauthors
Chen YG,Weeks JDdoi
10.1073/pnas.0600282103subject
Has Abstractpub_date
2006-05-16 00:00:00pages
7560-5issue
20eissn
0027-8424issn
1091-6490pii
0600282103journal_volume
103pub_type
杂志文章abstract::Allosteric regulation of oxygen delivery by RBCs may have significant effects on tumor growth. Indeed, angiogenesis, the formation of new blood vessels, is induced in growing tumors by low oxygen partial pressure. Hypoxia-inducible genes are switched on, among which are the VEGF gene and its receptors. Most important,...
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abstract::In organisms from insects to vertebrates, Toll-like receptors (TLRs) are primary pathogen detectors that activate downstream pathways, specifically those that direct expression of innate immune effector genes. TLRs also have roles in development in many species. The sea anemone Nematostella vectensis is a useful cnida...
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abstract::A series of pyrimidine nucleoside analogues containing [2',5'-bis-O-(tert-butyldimethylsilyl)-3'-spiro-5''-(4''-amino- 1'',2''-oxathiole-2'',2''-dioxide)]-beta-D-ribofuranose as the pentose were found to inhibit human immunodeficiency virus type 1 [HIV-1(IIIB)] replication at a concentration of 0.06-0.8 microM but wer...
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更新日期:1980-06-01 00:00:00
abstract::The rate of reproduction of deep-sea bacteria from six different capture depths between 1957 and 10,476 meters was studied as a function of temperature and pressure. The results showed the following: the true deep-sea bacteria of different depths have several characteristics, presumably evolutionally derived, distingu...
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更新日期:1990-03-01 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1994-12-06 00:00:00
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更新日期:2015-11-10 00:00:00
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更新日期:1972-06-01 00:00:00
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更新日期:2003-11-11 00:00:00
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更新日期:2011-05-03 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2016-10-11 00:00:00
abstract::The goal of this study was to characterize and classify pulmonary neuroendocrine tumors based on array comparative genomic hybridization (aCGH). Using aCGH, we performed karyotype analysis of 33 small cell lung cancer (SCLC) tumors, 13 SCLC cell lines, 19 bronchial carcinoids, and 9 gastrointestinal carcinoids. In con...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2010-07-20 00:00:00
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journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2012-10-16 00:00:00
abstract::A two-component transposon system based on the Ac element of maize was used as a mutagen in Arabidopsis thaliana. Transposition of a Ds element marked with a hygromycin-resistance gene was activated from four different locations in the Arabidopsis genome. The progeny of 201 plants carrying independent transposition ev...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1993-11-01 00:00:00
abstract::The alternative adaptive immune system of jawless vertebrates is based on different isotypes of variable lymphocyte receptors (VLRs) that are composed of leucine-rich repeats (LRRs) and expressed by distinct B- and T-like lymphocyte lineages. VLRB is expressed by B-like cells, whereas VLRA and VLRC are expressed by tw...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2014-10-14 00:00:00
abstract::A recombinant vaccinia virus that directs the synthesis of bacteriophage T7 RNA polymerase provides the basis for the expression of genes that are regulated by T7 promoters in mammalian cells. The T7 transcripts, which account for as much as 30% of the total cytoplasmic RNA at 24 hr after infection, are largely uncapp...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:1989-08-01 00:00:00
abstract::Expression of the bovine papillomavirus E2 regulatory protein in human cervical carcinoma cell lines repressed expression of the resident human papillomavirus E6 and E7 oncogenes and within a few days caused essentially all of the cells to synchronously display numerous phenotypic markers characteristic of cells under...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
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更新日期:2000-09-26 00:00:00
abstract::Bacterial virulence factors are typically surface-associated or secreted molecules that in Gram-negative bacteria must cross the outer membrane (OM). Protein translocation across the bacterial OM is not well understood. To elucidate this process we studied P pilus biogenesis in Escherichia coli. We present high-resolu...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
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更新日期:1998-03-17 00:00:00