Abstract:
:An essential element in the web-trap architecture, the capture silk spun by ecribellate orb spiders consists of glue droplets sitting astride a silk filament. Mechanically this thread presents a mixed solid-liquid behavior unknown to date. Under extension, capture silk behaves as a particularly stretchy solid, owing to its molecular nanosprings, but it totally switches behavior in compression to now become liquid-like: It shrinks with no apparent limit while exerting a constant tension. Here, we unravel the physics underpinning the unique behavior of this "liquid wire" and demonstrate that its mechanical response originates in the shape-switching of the silk filament induced by buckling within the droplets. Learning from this natural example of geometry and mechanics, we manufactured programmable liquid wires that present previously unidentified pathways for the design of new hybrid solid-liquid materials.
journal_name
Proc Natl Acad Sci U S Aauthors
Elettro H,Neukirch S,Vollrath F,Antkowiak Adoi
10.1073/pnas.1602451113subject
Has Abstractpub_date
2016-05-31 00:00:00pages
6143-7issue
22eissn
0027-8424issn
1091-6490pii
1602451113journal_volume
113pub_type
杂志文章abstract::We have developed a low stringency polymerase chain reaction (LSPCR) to isolate the unknown neighboring region around a known DNA sequence, thus allowing efficient targeted gene walking. The method involves the polymerase chain reaction (PCR) with a single primer under conditions of low stringency for primer annealing...
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.91.8.2975
更新日期:1994-04-12 00:00:00
abstract::The proteins cdc2 and cyclin form a heterodimer (maturation promoting factor) that controls the major events of the cell cycle. A mathematical model for the interactions of cdc2 and cyclin is constructed. Simulation and analysis of the model show that the control system can operate in three modes: as a steady state wi...
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.88.16.7328
更新日期:1991-08-15 00:00:00
abstract::This study presents, to our knowledge, the first on-line measurement of acetylcholinesterase (AcChoEase) release from brain tissue. It is now well established that a soluble form of the enzyme is released from central nervous system neurons, and it has been proposed on indirect grounds that such release may occur not ...
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.84.9.3047
更新日期:1987-05-01 00:00:00
abstract::Biological membranes contain an extraordinary diversity of lipids. Phospholipids function as major structural elements of cellular membranes, and analysis of changes in the highly heterogeneous mixtures of lipids found in eukaryotic cells is central to understanding the complex functions in which lipids participate. P...
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.131195098
更新日期:2001-06-19 00:00:00
abstract::It recently has been shown that epithelial Na(+) channels are controlled by a receptor for intracellular Na(+), a G protein (G(o)), and a ubiquitin-protein ligase (Nedd4). Furthermore, mutations in the epithelial Na(+) channel that underlie the autosomal dominant form of hypertension known as Liddle's syndrome inhibit...
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.96.17.9949
更新日期:1999-08-17 00:00:00
abstract::Molecular agitation more rapid than thermal Brownian motion is reported for cellular environments, motor proteins, synthetic molecular motors, enzymes, and common chemical reactions, yet that chemical activity coupled to molecular motion contrasts with generations of accumulated knowledge about diffusion at equilibriu...
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.2019810117
更新日期:2020-11-24 00:00:00
abstract::Genetic and biochemical studies on enzymes known to be involved in regulating DNA supercoiling yield a complex spectrum of effects on the Escherichia coli SOS system. Previous studies indicated that only inhibition of DNA gyrase by antibiotics that act on the DNA gyrase A subunit results in turning on the E. coli SOS ...
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.80.9.2510
更新日期:1983-05-01 00:00:00
abstract::MicroRNAs (miRNAs) are 18- to 24-nt RNA molecules that regulate messenger RNAs (mRNAs). Posttranscriptional mechanisms regulate miRNA abundance during development as well as in cancer cells where miRNAs frequently exhibit dysregulated expression. The molecular mechanisms that govern the global efficiency of miRNA biog...
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.0811523106
更新日期:2009-04-28 00:00:00
abstract::Preaxial polydactyly (PPD) is a common limb malformation in human. A number of polydactylous mouse mutants indicate that misexpression of Shh is a common requirement for generating extra digits. Here we identify a translocation breakpoint in a PPD patient and a transgenic insertion site in the polydactylous mouse muta...
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.112212199
更新日期:2002-05-28 00:00:00
abstract::Heterogeneous nucleation is vital to a wide range of areas as diverse as ice nucleation on atmospheric aerosols and the fabrication of high-performance thin films. There is excellent evidence that surface topography is a key factor in directing crystallization in real systems; however, the mechanisms by which nanoscal...
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.1617717114
更新日期:2017-01-31 00:00:00
abstract::We demonstrate that the receptor binding moiety of Escherichia coli heat-labile enterotoxin (EtxB) can completely prevent autoimmune disease in a murine model of arthritis. Injection of male DBA/1 mice at the base of the tail with type II collagen in the presence of complete Freund's adjuvant normally leads to arthrit...
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.94.10.5290
更新日期:1997-05-13 00:00:00
abstract::The bacterial adaptive immune system CRISPR-Cas9 has been appropriated as a versatile tool for editing genomes, controlling gene expression, and visualizing genetic loci. To analyze Cas9's ability to bind DNA rapidly and specifically, we generated multiple libraries of potential binding partners for measuring the kine...
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.1700557114
更新日期:2017-05-23 00:00:00
abstract::We analyze Niels Bohr's proposed two-slit interference experiment with highly charged particles which argues that the consistency of elementary quantum mechanics requires that the electromagnetic field must be quantized. In the experiment a particle's path through the slits is determined by measuring the Coulomb field...
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.0813239106
更新日期:2009-03-03 00:00:00
abstract::Alterations in serotonin (5-hydroxytriptamine, 5-HT), norepinephrine, and gamma-aminobutyric acid have been linked to the pathophysiology of anxiety and depression, and medications that modulate these neurotransmitters are widely used to treat mood disorders. Recently, the neuropeptide substance P (SP) and its recepto...
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.041596398
更新日期:2001-02-13 00:00:00
abstract::The timing of human colonization of East Polynesia, a vast area lying between Hawai'i, Rapa Nui, and New Zealand, is much debated and the underlying causes of this great migration have been enigmatic. Our study generates evidence for human dispersal into eastern Polynesia from islands to the west from around AD 900 an...
journal_title:Proceedings of the National Academy of Sciences of the United States of America
pub_type: 历史文章,杂志文章
doi:10.1073/pnas.1920975117
更新日期:2020-04-21 00:00:00
abstract::The GroE chaperonins assist substrate protein (SP) folding by cycling through several conformational states. With each cycle the SP is, in turn, captured, unfolded, briefly encapsulated (t1/2 ∼ 1 s), and released by the chaperonin complex. The protein-folding functional form is the US-football-shaped GroEL:GroES2 comp...
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.1412922111
更新日期:2014-09-02 00:00:00
abstract::Protein folding poses unique challenges for large, disordered proteins due to the low resolution of structural data accessible in experiment and on the basis of short time scales and limited sampling attainable in computation. Such molecules are uniquely suited to accelerated-sampling molecular dynamics algorithms due...
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.1801205115
更新日期:2018-07-10 00:00:00
abstract::In colloidal systems, the interplay between the short range attraction and long-range repulsion can lead to a low density associated state consisting of clusters of individual particles. Recently, such an equilibrium cluster phase was also reported for concentrated solutions of lysozyme at low ionic strength and close...
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.0711928105
更新日期:2008-04-01 00:00:00
abstract::Beneficial mutations are the driving force of adaptive evolution. In asexual populations, the identification of beneficial alleles is confounded by the presence of genetically linked hitchhiker mutations. Parallel evolution experiments enable the recognition of common targets of selection; yet these targets are inhere...
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.1702314114
更新日期:2017-08-01 00:00:00
abstract::Controlling calorie intake (CCI) extends healthful life-span by a mechanism that may involve reduced rates of cell division without detriment to inducible cellular responses. To test whether inducible cellular proliferation is preserved by CCI and whether the mRNA expression levels of oncogenes activated by cell divis...
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.89.12.5497
更新日期:1992-06-15 00:00:00
abstract::Male oriental fruit flies (Dacus dorsalis) from colonies in Taiwan and Hawaii were evaluated for limit of response to various analogues of methyl eugenol. The results are interpreted in terms of the geometry and allosteric requirements of the antennal receptor that triggers the characteristic methyl eugenol reflex. Th...
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.76.4.1561
更新日期:1979-04-01 00:00:00
abstract::Activated RAS transforming genes that encode proteins (p21s) with amino acid substitutions at positions 12, 13, or 61 have been detected in 10-20% of human neoplasms. This report describes a monoclonal antibody (DWP) raised against a synthetic peptide corresponding to amino acids 5-16 of a mutated RAS gene encoding Va...
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.83.19.7485
更新日期:1986-10-01 00:00:00
abstract::A tremendous amount of radioactivity was discharged because of the damage to cooling systems of nuclear reactors in the Fukushima No. 1 nuclear power plant in March 2011. Fukushima and its adjacent prefectures were contaminated with fission products from the accident. Here, we show a geographical distribution of radio...
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.1111724108
更新日期:2011-12-06 00:00:00
abstract::Conventional wisdom regarding mechanisms of bacterial pathogenesis holds that pathogens arise by external acquisition of distinct virulence factors, whereas determinants shared by pathogens and commensals are considered to be functionally equivalent and have been ignored as genes that could become adapted specifically...
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.95.15.8922
更新日期:1998-07-21 00:00:00
abstract::Lambdoid phages form clear plaques and show reduced ability to establish immunity in strains of Escherichia coli that lack adenylate cyclase or catabolite activator protein. The absence of the activator protein or cyclic AMP reduces the frequency of lysogenization, but does not prevent steady-state repressor synthesis...
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.69.2.366
更新日期:1972-02-01 00:00:00
abstract::High molecular weight proteins extracted from the walking nerves of the shore crab (Carcinus maenas) exhibit a cycle of phosphorylation-dephosphorylation that is influenced by neurotropic compounds and inorganic ions. The net phosphorylation state of the proteins is increased in the presence of K+ ions and decreased w...
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.77.2.812
更新日期:1980-02-01 00:00:00
abstract::Selenophosphate, an activated form of selenium that can serve as a selenium donor, is generated by the selD gene product, selenophosphate synthetase (SPS). Selenophosphate is required by several bacteria and by mammals for the specific synthesis of Secys-tRNA, the precursor of selenocysteine in selenoenzymes. Although...
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.0409042102
更新日期:2005-01-25 00:00:00
abstract::Understanding nuclear receptor signaling in vivo would be facilitated by an efficient methodology to determine where a nuclear receptor is active. Herein, we present a feedback-inducible expression system in transgenic mice to detect activated nuclear receptor effector proteins by using an inducible reporter gene. Wit...
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.96.23.13270
更新日期:1999-11-09 00:00:00
abstract::The lactose-H+ symport protein (LacS) of Streptococcus thermophilus has a C-terminal hydrophilic domain that is homologous to IIA protein(s) domains of the phosphoenolpyruvate:sugar phosphotransferase system (PTS). C-terminal truncation mutants were constructed and expressed in Escherichia coli and their properties we...
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.92.3.778
更新日期:1995-01-31 00:00:00
abstract::We recently showed that culture-derived metacyclic trypomastigotes (CMT), but not epimastigotes (Epi), of the Miranda 88 strain of Trypanosoma cruzi evade lysis by the human alternative complement pathway because of inefficient binding of factor B to complement component C3b on the parasite surface. These results sugg...
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.85.1.193
更新日期:1988-01-01 00:00:00