Abstract:
:A theory is proposed to study the sensitivity of cylindrical explosives. Using the equations governing the conservation of mass, energy, and momentum, the equation of state, and Newtonian mechanics, we have derived the expression D = D(o)e(-a2/d), in which the apparent length of the reaction zone, a, takes into account burned and unburned explosive and pressure release through the back and sides of the reaction zone. D is the detonation velocity and d is the diameter of the cylindrical charge. From the observed D(1/d) curves and critical energy values, we can interpret failure and other phenomena associated with detonation.
journal_name
Proc Natl Acad Sci U S Aauthors
Eyring H,Walker FE,Ma SM,Coon Ndoi
10.1073/pnas.77.5.2358subject
Has Abstractpub_date
1980-05-01 00:00:00pages
2358-61issue
5eissn
0027-8424issn
1091-6490journal_volume
77pub_type
杂志文章abstract::We have examined the affinity of two recently synthesized flavin analogs for the isoalloxazine binding site of riboflavin-binding protein (RBP). The results showed that pyrimidopteridines could bind to RBP (Kd 160-250 microM). This suggested that, at the FMN or FAD level, these analogs might also bind to other apoflav...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.81.14.4246
更新日期:1984-07-01 00:00:00
abstract::The lateral neural plate border (NPB), the neural part of the vertebrate neural border, is composed of central nervous system (CNS) progenitors and peripheral nervous system (PNS) progenitors. In invertebrates, PNS progenitors are also juxtaposed to the lateral boundary of the CNS. Whether there are conserved molecula...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1704194114
更新日期:2017-08-01 00:00:00
abstract::Heymann nephritis is an experimental autoimmune disease model for human membranous nephropathy. We have recently identified a pathogenic epitope, clone 14 (C14), responsible for formation and deposition of glomerular immune complexes that is contained within the small subunit of the Heymann nephritis antigenic complex...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.23.11179
更新日期:1992-12-01 00:00:00
abstract::Near-zero-index (NZI) supercoupling, the transmission of electromagnetic waves inside a waveguide irrespective of its shape, is a counterintuitive wave effect that finds applications in optical interconnects and engineering light-matter interactions. However, there is a limited knowledge on the local properties of the...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.2008143117
更新日期:2020-09-29 00:00:00
abstract::The "protein only" hypothesis states that the infectious agent causing transmissible spongiform encephalopathies is a conformational isomer of PrP, a host protein predominantly expressed in brain, and is strongly supported by many lines of evidence. Prion diseases are so far unique among conformational diseases in tha...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.172403799
更新日期:2002-12-10 00:00:00
abstract::In preeclampsia (PE), cytotrophoblast (CTB) invasion of the uterus and spiral arteries is often shallow. Thus, the placenta's role has been a focus. In this study, we tested the hypothesis that decidual defects are an important determinant of the placental phenotype. We isolated human endometrial stromal cells from no...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1706546114
更新日期:2017-10-03 00:00:00
abstract::The pathogenesis of tuberculous meningitis, a devastating complication of tuberculosis in man, is poorly understood. We previously reported that rabbits with experimental tuberculous meningitis were protected from death by a combination of antibiotics and thalidomide therapy. Survival was associated with inhibition of...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.96.10.5657
更新日期:1999-05-11 00:00:00
abstract::The basic theory of a newly discovered physical technique, steady-state electrophoresis, is described followed by analyses of several representative macro-ion systems with the technique. This method measures apparent moments of molar diminished charge (defined below) of solvated macro-ions from an analysis of a concen...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.12.4479
更新日期:1989-06-01 00:00:00
abstract::cGMP is a second messenger that mediates numerous metabolic events; in the present work a role in myeloid cell differentiation was demonstrated. Nitroprusside and NaNO2, which activate cytosolic guanylate cyclase and increase the intracellular cGMP concentration, induced granulocytic differentiation of the human promy...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.86.18.7174
更新日期:1989-09-01 00:00:00
abstract::The flow orientation of anisotropic particles through narrow channels is of importance in many fields, ranging from the spinning and molding of fibers to the flow of cells and proteins through thin capillaries. It is commonly assumed that anisotropic particles align parallel to the flow direction. When flowing through...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1219340110
更新日期:2013-04-23 00:00:00
abstract::Paclitaxel has emerged as a front line treatment for aggressive malignancies of the breast, lung, and ovary. Successful therapy of cancer is frequently undermined by the development of paclitaxel resistance. There is a growing need to find other therapeutic targets to facilitate treatment of drug-resistant cancers. Us...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0910649107
更新日期:2010-02-09 00:00:00
abstract::Bone mineralization is an essential step during the embryonic development of vertebrates, and bone serves vital functions in human physiology. To systematically identify unique gene functions essential for osteogenesis, we performed a forward genetic screen in zebrafish and isolated a mutant, no bone (nob), that does ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1214231110
更新日期:2012-12-26 00:00:00
abstract::We have shown that rat glioma tumors contain a protein that crossreacts with antibody against mouse 2.5S nerve growth factor prepared in rabbit in microcomplement fixation assays and has analogous isoelectric points to all the hybrids of 2.5S nerve growth factor (a dimer). Partially purified protein preparations from ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.71.6.2347
更新日期:1974-06-01 00:00:00
abstract::People who are more avoidant of pathogens are more politically conservative, as are nations with greater parasite stress. In the current research, we test two prominent hypotheses that have been proposed as explanations for these relationships. The first, which is an intragroup account, holds that these relationships ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章,多中心研究
doi:10.1073/pnas.1607398113
更新日期:2016-11-01 00:00:00
abstract::Monocytes originate from precursors made in the bone and remain in the circulation for nearly 24 h. Much effort has been done to identify the molecules regulating transendothelial migration of monocytes during inflammatory conditions. In contrast, considerably less is known about the process of constitutive monocyte e...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0700732104
更新日期:2007-03-27 00:00:00
abstract::Microorganisms must sense their environment and rapidly tune their metabolism to ambient conditions to efficiently use available resources. We have identified a gene encoding a response regulator, NblR, that complements a cyanobacterial mutant unable to degrade its light-harvesting complex (phycobilisome), in response...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.95.18.11008
更新日期:1998-09-01 00:00:00
abstract::Endocrine therapy resistance invariably develops in advanced estrogen receptor-positive (ER+) breast cancer, but the underlying mechanisms are largely unknown. We have identified C-terminal SRC kinase (CSK) as a critical node in a previously unappreciated negative feedback loop that limits the efficacy of current ER-t...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1722617115
更新日期:2018-07-31 00:00:00
abstract::Previous studies have shown that the helical RecA nucleoprotein filament formed on a circular single strand of DNA causes the progressive, directional transfer of a complementary strand from naked linear duplex DNA to the nucleoprotein filament, even when the duplex contains a sizable heterologous insertion. Since Rec...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.89.16.7596
更新日期:1992-08-15 00:00:00
abstract::Previous studies have identified human breast tumor particles possessing many of the features characteristic of RNA tumor viruses. In addition to the expected size (600 S) and density (1.16 g/ml) these include possession of an outer membrane and an inner one surrounding a "core" containing a DNA polymerase and a large...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.74.2.764
更新日期:1977-02-01 00:00:00
abstract::Long interspersed nuclear elements 1 (L1) are active retrotransposons that reside in many species, including humans and rodents. L1 elements produce an RNA intermediate that is reverse transcribed to DNA and inserted in a new genomic location. We have tagged an active human L1 element (L1(RP)) with a gene encoding enh...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0337627100
更新日期:2003-02-18 00:00:00
abstract::Female Utetheisa ornatrix exercise postcopulatory mate selection, favoring sperm of larger males. Larger males also produce larger spermatophores, raising the question whether males are selected on the basis of body size or the size of their spermatophore. We here present evidence, based on matings in which males were...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.91.15.7081
更新日期:1994-07-19 00:00:00
abstract::Opioid drugs produce their pharmacological effects by activating inhibitory guanine nucleotide-binding regulatory protein-linked mu, delta, and kappa opioid receptors. One major effector for these receptors is adenylyl cyclase, which is inhibited upon receptor activation. However, little is known about which of the te...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.0508812103
更新日期:2006-03-07 00:00:00
abstract::In eukaryotes, ubiquitination is an important posttranslational process achieved through a cascade of ubiquitin-activating (E1), conjugating (E2), and ligase (E3) enzymes. Many pathogenic bacteria deliver virulence factors into the host cell that function as E3 ligases. How these bacterial "Trojan horses" integrate in...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1115025109
更新日期:2012-02-07 00:00:00
abstract::Levels and subcellular distribution of connexin 43 (Cx43), a gap junction protein, were studied in hamster leukocytes before and after activation with endotoxin (lipopolysaccharide, LPS) both in vitro and in vivo. Untreated leukocytes did not express Cx43. However, Cx43 was clearly detectable by indirect immunofluores...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.92.15.7011
更新日期:1995-07-18 00:00:00
abstract::On the basis of earlier energy computations, the various single peptide units in proteins were designated as helix-making or helix-breaking.(1) With the use of these designations, empirical rules for distinguishing between alpha-helical and non-alpha-helical regions of proteins have been formulated. These rules includ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.62.1.14
更新日期:1969-01-01 00:00:00
abstract::An argument is presented in favor of the hypothesis that, bovine carboxypeptidases A and B fit by and large, the concept of homology on the levels of both amino acid sequence and three-dimensional structure. Two peptide sequences from carboxypeptidases A and B, comprising 46 amino acid residues, display structural hom...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.63.2.406
更新日期:1969-06-01 00:00:00
abstract::Using brain transcriptomic profiles from 853 individual honey bees exhibiting 48 distinct behavioral phenotypes in naturalistic contexts, we report that behavior-specific neurogenomic states can be inferred from the coordinated action of transcription factors (TFs) and their predicted target genes. Unsupervised hierar...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1114093108
更新日期:2011-11-01 00:00:00
abstract::The recruitment and evolutionary optimization of promiscuous enzymes is key to the rapid adaptation of organisms to changing environments. Our understanding of the precise mechanisms underlying enzyme repurposing is, however, limited: What are the active-site features that enable the molecular recognition of multiple ...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1607817115
更新日期:2018-07-31 00:00:00
abstract::DG42 is one of the main mRNAs expressed during gastrulation in embryos of Xenopus laevis. Here we demonstrate that cells expressing this mRNA synthesize hyaluronan. The cloned DG42 cDNA was expressed in rabbit kidney (RK13) and human osteosarcoma (tk-) cells using a vaccinia virus system. Lysates prepared from infecte...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.93.10.4543
更新日期:1996-05-14 00:00:00
abstract::Phages of the Caudovirales order possess a tail that recognizes the host and ensures genome delivery upon infection. The X-ray structure of the approximately 1.8 MDa host adsorption device (baseplate) from the lactococcal phage TP901-1 shows that the receptor-binding proteins are pointing in the direction of the host,...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 杂志文章
doi:10.1073/pnas.1200966109
更新日期:2012-06-05 00:00:00