Thematische Bibliographien / Quasi-Alpha

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Auswahl der wissenschaftlichen Literatur zum Thema „Quasi-Alpha“

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Veröffentlicht am 18. Mai 2024

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Zeitschriftenartikel zum Thema "Quasi-Alpha"

KOWALSKI, ZBIGNIEW S. „Quasi-Markovian transformations“. Ergodic Theory and Dynamical Systems 17, Nr. 4 (August 1997): 885–97. http://dx.doi.org/10.1017/s0143385797086264.

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Let $(f,\alpha)$ be the process given by an endomorphism $f$ and by a finite partition $\alpha=\{A\}_{i=1}^{s}$ of a Lebesgue space. Let $E(f,\alpha)$ be the set of densities of absolutely continuous invariant measures for skew products with the base $(f,\alpha)$. We prove that a process $(f,\alpha)$ is Markovian if and only if $E(f,\alpha)\subset \{g: g=\sum_{i=1}^{s} 1_{A_{i}}\otimes g_{i}\}$. If $f$ is the Lasota–Yorke or Misiurewicz type map with the Markovian partition $\alpha$, then $(f,\alpha)$ is quasi-Markovian, i.e. $E(f,\alpha)\subset \{g:\supp g=\bigcup_{i=1}^{s} A_{i}\times B_{i}\}$. Moreover, we give the characterization of quasi-Markovian processes.

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Patrick Udoudo, Unyime, und Ette Harrison Etuk. „Alpha power transformed quasi lindley distribution“. International Journal of Advanced Statistics and Probability 9, Nr. 1 (19.03.2021): 6. http://dx.doi.org/10.14419/ijasp.v9i1.31208.

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In this study, we proposed and studied the alpha power transformed quasi Lindley distribution. The new model has three sub models, namely, Lindley, quasi Lindley and alpha power transformed Lindley distributions. The pdf, hazard rate function, quantile function, mo-ments, Rényi entropy, stochastic ordering and distributions of order statistics were derived based on the new model. The maximum like-lihood method of estimating the model parameters was considered. A simulation study was conducted to investigate the behavior of the maximum likelihood estimates. It was observed that the average bias and mean squared error decreased as the sample size increased. By analyzing a real data set, we illustrated the usefulness of the proposed distribution.

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Noor, Khalida Inayat. „Some classes of alpha-quasi-convex functions“. International Journal of Mathematics and Mathematical Sciences 11, Nr. 3 (1988): 497–501. http://dx.doi.org/10.1155/s0161171288000584.

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LetC[C,D],−1≤D<C≤1denote the class of functionsg,g(0)=0,g′(0)=1, analytic in the unit diskEsuch that(zg′(z))′g′(z)is subordinate to1+CZ1+DZ,z∈E. We investigate some classes of Alpha-Quasi-Convex Functionsf, withf(0)=f′(0)−1=0for which there exists ag∈C[C,D]such that(1−α)f′(z)g′(z)+α(zf′(z))′g′(z)is subordinate to1+AZ1+BZ′,−1≤B<A≤1. Integral representation, coefficient bounds are obtained. It is shown that some of these classes are preserved under certain integral operators.

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Abdel-Gawad, H. R. „On the Fekete-Szego problem for alpha-quasi-convex functions“. Tamkang Journal of Mathematics 31, Nr. 4 (31.12.2000): 251–56. http://dx.doi.org/10.5556/j.tkjm.31.2000.381.

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Meftah, B., und A. Souahi. „Cebyšev inequalities for co-ordinated $QC$-convex and $(s,QC)$-convex“. Engineering and Applied Science Letters 4, Nr. 1 (23.01.2021): 14–20. http://dx.doi.org/10.30538/psrp-easl2021.0057.

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In this paper, we establish some new Cebyšev type inequalities for functions whose modulus of the mixed derivatives are co-ordinated quasi-convex and $\alpha $-quasi-convex and $s$-quasi-convex functions.

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Royer, G. „Alpha emission and spontaneous fission through quasi-molecular shapes“. Journal of Physics G: Nuclear and Particle Physics 26, Nr. 8 (27.06.2000): 1149–70. http://dx.doi.org/10.1088/0954-3899/26/8/305.

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Mahmood, Shahid, Sarfraz Nawaz Malik, Sumbal Farman, S. M. Jawwad Riaz und Shabieh Farwa. „Uniformly Alpha-Quasi-Convex Functions Defined by Janowski Functions“. Journal of Function Spaces 2018 (2018): 1–7. http://dx.doi.org/10.1155/2018/6049512.

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In this work, we aim to introduce and study a new subclass of analytic functions related to the oval and petal type domain. This includes various interesting properties such as integral representation, sufficiency criteria, inclusion results, and the convolution properties for newly introduced class.

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Littin Curinao, Jorge. „Asymptotic behavior and quasi-limiting distributions on time-fractional birth and death processes“. Journal of Applied Probability 59, Nr. 4 (11.11.2022): 1199–227. http://dx.doi.org/10.1017/jpr.2022.14.

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AbstractIn this article we provide new results for the asymptotic behavior of a time-fractional birth and death process $N_{\alpha}(t)$ , whose transition probabilities $\mathbb{P}[N_{\alpha}(t)=\,j\mid N_{\alpha}(0)=i]$ are governed by a time-fractional system of differential equations, under the condition that it is not killed. More specifically, we prove that the concepts of quasi-limiting distribution and quasi-stationary distribution do not coincide, which is a consequence of the long-memory nature of the process. In addition, exact formulas for the quasi-limiting distribution and its rate convergence are presented. In the first sections, we revisit the two equivalent characterizations for this process: the first one is a time-changed classic birth and death process, whereas the second one is a Markov renewal process. Finally, we apply our main theorems to the linear model originally introduced by Orsingher and Polito [23].

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Nicolopoulos, Anouk, Martin Campos Pinto, Bruno Després und Patrick Ciarlet. „Degenerate elliptic equations for resonant wave problems“. IMA Journal of Applied Mathematics 85, Nr. 1 (Februar 2020): 132–59. http://dx.doi.org/10.1093/imamat/hxaa001.

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Abstract The modelling of resonant waves in 2D plasma leads to the coupling of two degenerate elliptic equations with a smooth coefficient $\alpha $ and compact terms. The coefficient $\alpha $ changes sign. The region where $\{\alpha>0\}$ is propagative, and the region where $\{\alpha <0\}$ is non propagative and elliptic. The two models are coupled through the line $\varSigma =\{\alpha =0\}$. Generically, it is an ill-posed problem and additional information must be introduced to get a satisfactory treatment at $\varSigma $. In this work, we define the solution by relying on the limiting absorption principle ($\alpha $ is replaced by $\alpha +i0^+$) in an adapted functional setting. This setting lies on the decomposition of the solution in a regular and a singular part, which originates at $\varSigma $, and on quasi-solutions. It leads to a new well-posed mixed variational formulation with coupling. As we design explicit quasi-solutions, numerical experiments can be carried out, which illustrate the good properties of this new tool for numerical computation.

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Basar, E., und M. Schurmann. „Alpha Rhythms in the Brain: Functional Correlates“. Physiology 11, Nr. 2 (01.04.1996): 90–96. http://dx.doi.org/10.1152/physiologyonline.1996.11.2.90.

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Experimental evidence suggests a functional significance of electroencephalographic (EEG) alpha rhythms. Event-related, evoked, and induced alpha rhythms may have functional correates in primary sensory processing and preparatory processes. These results are in accord with the view that spontaneous and induced EEG alpha rhythms have quasi-deterministic properties.

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Mehr Quellen

Dissertationen zum Thema "Quasi-Alpha"

Boutana, Mohammed Nabil. „Modélisation microstructurale en fatigue/fluage à froid des alliages de titane quasi alpha par le modèle des automates cellulaires“. Mémoire, École de technologie supérieure, 2009. http://espace.etsmtl.ca/29/1/BOUTANA_Mohammed_Nabil.pdf.

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Les alliages de titane quasi alpha combinent de bonnes propriétés en fluage et en fatigue à des températures relativement hautes. Cela a ainsi permis l'augmentafion des températtires de service des compresseurs à haute pression à environ 600°C. Cependant, des difficultés sont appames, liées à l'utilisation de cet alliage et au contrôle difficile de l'évolution de sa micro structure pendant les étapes de mise en forme. Ces microstmctures sont caractérisées par des hétérogénéités locales d'orientation qui compromettent leur utilisation sécuritaire. Afin de mieux comprendre leur comportement en service et apporter des réponses quant à leiu- utilisation sécuritaire, un modèle numérique original basé sur une nouvelle approche appelée automate cellulaire utilisant la mécanique d'inclusion d'Eshelby a été réalisé. Cette approche permettra de déterminer les propriétés mécaniques locales de ce type d'alliage lors de son utilisation en fatigue-fluage, à savoir les déformations, contraintes, vitesses de déformations, déformations et contraintes résiduelles. Dans cette optique, l'analyse microstmcturale nous aide à mieux comprendre l'effet de l'orientation cristallographique et la distribution des grains sur le comportement mécanique global du matériau. A ce titre on a remarqué que les contraintes maximales sont localisées sur les grains avec module d'Young élevé et dont le module moyen du voisinage est élevé. Les déformations maximales ont été localisées sur des grains avec module d'Young faible et dont le module moyen du voisinage est élevé. D'autre part on a constaté que la contrainte locale de certains grains est fortement supérieure à la contrainte imposée à l'infini, d'où la possibilité que certains grains atteignent la contrainte de clivage, ce qui générerait tme fissure au niveau du grain. Au fin et à mesure que le nombre de cycles augmente, de nouveaux grains peuvent atteindre la contrainte de clivage, suggérant la possibilité d'activer plusieurs sites d'amorçage et ce à des moments différents des essais de fatigue-fluage. À l'échelle macroscopique on a démontré que des microstmctures semblables du point de vue propriétés mécaniques moyenne mais différentes selon l'orientation et la distribution spafiale des grains peuvent avoir des comportements locaux et globaux très différents. La difficulté rencontrée à simuler les principales caractéristiques de la fatigue-fluage a permis de mettre en évidence le caractère complexe de ce mode d'endommagement.

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Laporte, Julien. „Modulation fonctionnelle de l'IRES du virus de l'hépatite C en fonction de sa variabilité génétique : relations avec la réplication extrahépatique et la résistance au traitement par l'interféron alpha“. Paris 6, 2002. http://www.theses.fr/2002PA066209.

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Armanni, Thibaut. „Étude de nouveaux alliages de titane pour applications aéronautiques hautes températures“. Electronic Thesis or Diss., Université de Lorraine, 2023. http://www.theses.fr/2023LORR0342.

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L'amélioration de la tenue en température des alliages de titane représente un défi de taille pour l'industrie aéronautique. En effet, dépasser la limite actuelle de 550°C dans les turbomoteurs requiert de trouver le meilleur compromis entre une bonne tenue à l'oxydation et de bonnes propriétés mécaniques en température. Les alliages dits quasi-alpha, constitués majoritairement de phase hexagonale compacte, sont ceux qui offrent les meilleures performances. Ils sont malheureusement sensibles à la fatigue/fluage à froid dit effet Dwell. Dans ce contexte, l'objectif de notre travail est double. D'une part, il s'agit de contribuer à la conception de nouveaux alliages quasi-alpha par apprentissage automatique grâce à une campagne extensive de caractérisation des propriétés mécaniques, à l'ambiante et à chaud. D'autre part, il s'agit de mieux comprendre l'impact de la composition chimique, notamment la teneur en silicium, sur la microstructure et le comportement mécanique. Pour cela, notre démarche a reposé sur la caractérisation de la microstructure de plusieurs alliages sélectionnés judicieusement, en croisant différentes techniques de microscopie. Nous avons ainsi examiné l'influence d'une variation de la teneur en silicium à différentes échelles, en combinant la microscopie électronique à balayage (MEB) et la microscopie électronique en transmission (MET). Nous avons mis en évidence la précipitation de siliciures au-delà d'une certaine teneur en Si, et entrepris de les caractériser de manière approfondie. En particulier, nous avons démontré les limitations d'une analyse en deux dimensions, et nous avons utilisé une technique alternative, combinant le découpage par faisceau d'ions (FIB) et l'observation par MEB pour reconstruire la microstructure en trois dimensions. Cette approche nous a permis d'observer en détail les formes, les tailles et les répartitions spatiales des siliciures. Enfin, nous avons mené des essais de traction à différentes vitesses de déformation ainsi que des essais de fluage dans diverses conditions, pour mieux comprendre le rôle bénéfique du silicium sur le comportement à froid et à chaud des alliages quasi-alpha
Improving the high-temperature resistance of titanium alloys is a major challenge for the aerospace industry. Exceeding the current limit of 550°C in aircraft engines requires finding the best compromise between good oxidation resistance and good mechanical properties. Near-alpha alloys consisting mainly of a compact hexagonal phase are the best candidates. Unfortunately, they are sensitive to cold creep-fatigue, known as the dwell effect. In this context, our work aims to achieve two main objectives. Firstly, to contribute to the design of new near-alpha alloys based on machine learning, supported by extensive mechanical testing, at both ambient and high temperatures. Secondly, to gain a better understanding of the effect of chemical composition, particularly silicon content, on the microstructure and mechanical behaviour. Our approach was based on multi-scale microstructure study of selected alloys using a combination of different microscopy techniques. We examined the influence of a variation in silicon content using a combination of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). We showed that silicide precipitation occurs above a certain silicon content. We demonstrated the limitations of two-dimensional analysis, and used an alternative technique combining ion beam cutting (FIB) with SEM observation to reconstruct the 3D microstructure. This approach enabled us to analyze and quantify the shapes, sizes and spatial distributions of the silicides. Finally, we carried out tensile tests at different strain rates as well as creep tests under various conditions to better understand how silicon addition improves the behaviour of near-alpha alloys

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Bücher zum Thema "Quasi-Alpha"

Cook, Jeremy Charles. Quasi-elastic neutron scattering studies of hydrogen and deuterium diffusion in the systems[alpha]-NbD[inferior][xi]and[alpha]-NbD[inferior][xi]. Birmingham: University of Birmingham, 1990.

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Buchteile zum Thema "Quasi-Alpha"

Wu, Xiu-Yun, Li-Li Xie und Shi-Zhong Bai. „Characterizations of $$\alpha $$ -Quasi Uniformity and Theory of $$\alpha $$ -P.Q. Metrics“. In Advances in Intelligent Systems and Computing, 125–36. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-38667-1_14.

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Ma, Minghui, und Ahti-Veikko Pietarinen. „A Weakening of Alpha Graphs: Quasi-Boolean Algebras“. In Diagrammatic Representation and Inference, 549–64. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-91376-6_50.

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Kanada-En’yo, Yoshiko, Hideaki Matsuno und Naoyuki Itagaki. „Tensor Correlations in $$\alpha $$ Clustering Studied with Antisymmetrized Quasi Cluster Model“. In Recent Progress in Few-Body Physics, 85–89. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-32357-8_15.

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Noor, Khalida Inayat. „On Alpha-Quasi-Convex Functions Defined by Convolution with Incomplete Beta Functions“. In Analytic and Geometric Inequalities and Applications, 265–76. Dordrecht: Springer Netherlands, 1999. http://dx.doi.org/10.1007/978-94-011-4577-0_16.

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Boostani, Alireza Fadavi, Shiraz Mujahid, Andrew L. Oppedal, Cory Krivanec, Wilburn R. Whittington, Paul G. Allison, Jishnu J. Bhattacharyya, Sean Agnew und Haitham El Kadiri. „Heat Treatment Strategies to Improve the Quasi-Static and Dynamic Performance of Alpha + Beta Titanium Alloys“. In TMS 2019 148th Annual Meeting & Exhibition Supplemental Proceedings, 1383–87. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-05861-6_131.

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Vidyasagar, M. „Hidden Markov Processes: The Complete Realization Problem“. In Hidden Markov Processes. Princeton University Press, 2014. http://dx.doi.org/10.23943/princeton/9780691133157.003.0007.

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This chapter considers hidden Markov processes (HMPs), focusing on the so-called complete realization problem. It is quite easy to prove a universal necessary condition for the given process to have a hidden Markov model (HMM). However, this condition is not sufficient in general. In principle, one can derive a “necessary and sufficient condition,” but the “necessary and sufficient condition” is virtually a restatement of the problem to be solved and does not shed any insight into the solution. The chapter first introduces a very useful matrix known as the “Hankel” matrix before discussing the nonsufficiency of the finite Hankel rank condition, an abstract necessary and sufficient condition, and the existence of regular quasi-realizations. It also describes the spectral properties of alpha-mixing processes and goes on to analyze ultra-mixing processes and a sufficient condition for the existence of HMMs.

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Konferenzberichte zum Thema "Quasi-Alpha"

Rodrigues, M. R. D., T. Borello-Lewin, H. Miyake, L. B. Horodynski-Matsushigue, J. L. M. Duarte, C. L. Rodrigues, M. A. Souza et al. „Quasi-bound alpha resonant states populated by the 12C(6Li,d) reaction“. In XXXV BRAZILIAN WORKSHOP ON NUCLEAR PHYSICS. AIP, 2013. http://dx.doi.org/10.1063/1.4807468.

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Amadou, N., Erik Brambrink, Alessandra Benuzzi-Mounaix, T. Vinci, Thibaut de Resseguier, S. Mazevet, G. Morard et al. „Laser-driven quasi-isentropic compression experiments and numerical studies of the iron alpha-epsilon transition in the context of planetology“. In SHOCK COMPRESSION OF CONDENSED MATTER - 2011: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter. AIP, 2012. http://dx.doi.org/10.1063/1.3686573.

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Kelleher, Daniel E., D. Oza und R. L. Greene. „Collisional broadening of hydrogenic ion transitions of interest in x-ray lasers“. In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1986. http://dx.doi.org/10.1364/oam.1986.wp6.

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The gain coefficient depends on the differential oscillator strength at the peak of the lasing transition. Thus it depends directly on the spectral width of the transition. We discuss below the collisional broadening of hydrogenic transitions in plasmas. In a plasma, atomic and ionic transitions are broadened by collisions with electrons and ions. This effect tends to be particularly large for hydrogenic radiators, which experience a first-order Stark effect. In line-broadening, a hydrogenic radiator is one in which a level in the transition is quasi-degenerate with another level to which it is dipole-coupled, i.e., their energy separation is smaller than their homogeneous width. The Balmer-alpha (n = 3 → 2) transition of C5+ has been used by the Princeton x-ray laser group to achieve an enhancement of stimulated-to-spontaneous emission by a factor of ~100.1 We have performed detailed calculations of the collisional broadening of this line and the Balmer-beta (n = 4 → 2) transition over a wide range of plasma conditions. The calculations include dynamic many-body ion collisions, which are the dominant broadening mechanism. For plasma conditions of current x-ray laser experiments,1 the collisional width of Balmer-alpha is comparable with the Doppler width, and at higher densities it dominates.

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Drljača, Tamara, Kristina Stevanović, Draginja Radošević, Jelena Milićević, Nevena Veljković und Sanja Glišić. „In silico screening of Solanum lycopersicum carotenoids from Carotenoids Database for candidates PPARα agonists“. In 2nd International Conference on Chemo and Bioinformatics. Institute for Information Technologies, University of Kragujevac, 2023. http://dx.doi.org/10.46793/iccbi23.605d.

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Peroxisome proliferator-activated receptor alpha (PPARα) is crucial in regulating lipid metabolism. Clinically, PPARα is significant as a possible therapeutic target for a variety of human disorders, including cardiovascular, neurological, and metabolic syndromes. The wide range of natural compounds provides great opportunities for new approaches in targeting PPARα. Carotenoids, a large class of natural compounds, have been recognized as PPARα agonists. Tomatoes (Solanum lycopersicum) are one of the most widely grown crops in the world and contain compounds that improve lipid metabolism. Since there is no data on tomato carotenoids as PPARα agonists in this study, we focused on searching carotenoids from tomatoes as possible PPARα agonists. The Solanum lycopersicum carotenoids from Carotenoids Database were in silico screened using a combined protocol with the Electron-Ion Interaction Potential/Average Quasi Valence Number (EIIP/AQVN) filter and molecular docking to find the most promising candidate compounds. The best resulting compounds may have the promise to be further developed as candidates for PPARα agonists.

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Keten, Sinan, und Markus J. Buehler. „Elasticity and Strength of Beta-Sheet Protein Materials: Geometric Confinement and Size Effects“. In ASME 2009 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2009. http://dx.doi.org/10.1115/sbc2009-205464.

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Elasticity and strength of proteins influence their biological functions. Under external forces, many proteins exhibit entropic elasticity with a characteristic stiffening elastic behavior and unravel due to the rupture of interstrand H-bonds. We develop a fracture mechanics based theoretical framework that considers the free energy competition between entropic elasticity of polypeptide chains and rupture of peptide hydrogen bonds, which we use here to provide an explanation for the intrinsic strength limit of protein domains at vanishing rates [1, 2]. Our analysis predicts that individual protein domains stabilized only by hydrogen bonds cannot exhibit rupture forces larger than 100–300 pN in the asymptotic quasi-static limit. This result explains earlier experimental and computational observations that suggest such a universal, asymptotic strength limit at vanishing pulling rates. We show that the rupture strength of H-bond assemblies in beta-sheets is governed by geometric confinement effects, suggesting that clusters of at most 3–4 H-bonds break concurrently, even under uniform shear loading of a much larger number of H-bonds. These strength, elasticity and size effect predictions all agree well with recent experimental findings and proteomics data. Our model confirms that fracture mechanics concepts, previously primarily applied to macroscale fracture phenomena, can also be directly applied at nanoscale, to be used for describing failure mechanisms in protein materials. Our strength and optimal size predictions lead to a key hypothesis: confined H-bond clusters are prevalent in alpha helices, beta-sheets and beta-solenoids, perhaps as an evolutionary design principle that derives from generic mechanical properties of the fundamental building blocks of life.

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