Artigos de revistas: "Molecular machines and motors"

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Endow, Sharyn A. "Kinesin motors as molecular machines". BioEssays 25, n.º 12 (17 de novembro de 2003): 1212–19. http://dx.doi.org/10.1002/bies.10358.

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Kistemaker, Jos C. M., Anouk S. Lubbe e Ben L. Feringa. "Exploring molecular motors". Materials Chemistry Frontiers 5, n.º 7 (2021): 2900–2906. http://dx.doi.org/10.1039/d0qm01091j.

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The introduction of mechanical functions and controlled motion based on molecular motors and machines offers tremendous opportunities towards the design of dynamic molecular systems and responsive materials.

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Kay, Euan R, David A Leigh e Francesco Zerbetto. "Synthetic Molecular Motors and Mechanical Machines". Angewandte Chemie International Edition 46, n.º 1-2 (janeiro de 2007): 72–191. http://dx.doi.org/10.1002/anie.200504313.

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Kay, Euan R., e David A. Leigh. "Beyond switches: Rotaxane- and catenane-based synthetic molecular motors". Pure and Applied Chemistry 80, n.º 1 (1 de janeiro de 2008): 17–29. http://dx.doi.org/10.1351/pac200880010017.

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Nature uses molecular motors and machines in virtually every significant biological process, but learning how to design and assemble simpler artificial structures that function through controlled molecular-level motion is a major challenge for contemporary physical science. The established engineering principles of the macroscopic world can offer little more than inspiration to the molecular engineer who creates devices for an environment where everything is constantly moving and being buffeted by other atoms and molecules. Rather, experimental designs for working molecular machines must follow principles derived from chemical kinetics, thermodynamics, and nonequilibrium statistical physics. The remarkable characteristics of interlocked molecules make them particularly useful for investigating the control of motion at the molecular level. Yet, the vast majority of synthetic molecular machines studied to date are simple two-state switches. Here we outline recent developments from our laboratory that demonstrate more complex molecular machine functions. This new generation of synthetic molecular machines can move continuously and progressively away from equilibrium, and they may be considered true prototypical molecular motors. The examples discussed exemplify two, fundamentally different, "Brownian ratchet" mechanisms previously developed in theoretical statistical physics and realized experimentally in molecular-level devices for the first time in these systems.

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Credi, Alberto, e Margherita Venturi. "Molecular machines operated by light". Open Chemistry 6, n.º 3 (1 de setembro de 2008): 325–39. http://dx.doi.org/10.2478/s11532-008-0033-4.

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AbstractThe bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. Researchers in this field are stimulated and inspired by the outstanding progress of molecular biology that has begun to reveal the secrets of the natural nanomachines which constitute the material base of life. Like their macroscopic counterparts, nanoscale machines need energy to operate. Most molecular motors of the biological world are fueled by chemical reactions, but research in the last fifteen years has demonstrated that light energy can be used to power nanomachines by exploiting photochemical processes in appropriately designed artificial systems. As a matter of fact, light excitation exhibits several advantages with regard to the operation of the machine, and can also be used to monitor its state through spectroscopic methods. In this review we will illustrate the design principles at the basis of photochemically driven molecular machines, and we will describe a few examples based on rotaxane-type structures investigated in our laboratories.

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Dunn, K. E., M. C. Leake, A. J. M. Wollman, M. A. Trefzer, S. Johnson e A. M. Tyrrell. "An experimental study of the putative mechanism of a synthetic autonomous rotary DNA nanomotor". Royal Society Open Science 4, n.º 3 (março de 2017): 160767. http://dx.doi.org/10.1098/rsos.160767.

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DNA has been used to construct a wide variety of nanoscale molecular devices. Inspiration for such synthetic molecular machines is frequently drawn from protein motors, which are naturally occurring and ubiquitous. However, despite the fact that rotary motors such as ATP synthase and the bacterial flagellar motor play extremely important roles in nature, very few rotary devices have been constructed using DNA. This paper describes an experimental study of the putative mechanism of a rotary DNA nanomotor, which is based on strand displacement, the phenomenon that powers many synthetic linear DNA motors. Unlike other examples of rotary DNA machines, the device described here is designed to be capable of autonomous operation after it is triggered. The experimental results are consistent with operation of the motor as expected, and future work on an enhanced motor design may allow rotation to be observed at the single-molecule level. The rotary motor concept presented here has potential applications in molecular processing, DNA computing, biosensing and photonics.

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Siletti, Kimberly. "Roop Mallik: From machines to molecular motors". Journal of Cell Biology 216, n.º 4 (27 de março de 2017): 852–53. http://dx.doi.org/10.1083/jcb.201703074.

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Tafoya, Sara, e Carlos Bustamante. "Molecular switch-like regulation in motor proteins". Philosophical Transactions of the Royal Society B: Biological Sciences 373, n.º 1749 (7 de maio de 2018): 20170181. http://dx.doi.org/10.1098/rstb.2017.0181.

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Motor proteins are powered by nucleotide hydrolysis and exert mechanical work to carry out many fundamental biological tasks. To ensure their correct and efficient performance, the motors' activities are allosterically regulated by additional factors that enhance or suppress their NTPase activity. Here, we review two highly conserved mechanisms of ATP hydrolysis activation and repression operating in motor proteins—the glutamate switch and the arginine finger—and their associated regulatory factors. We examine the implications of these regulatory mechanisms in proteins that are formed by multiple ATPase subunits. We argue that the regulatory mechanisms employed by motor proteins display features similar to those described in small GTPases, which require external regulatory elements, such as dissociation inhibitors, exchange factors and activating proteins, to switch the protein's function ‘on’ and ‘off'. Likewise, similar regulatory roles are taken on by the motor's substrate, additional binding factors, and even adjacent subunits in multimeric complexes. However, in motor proteins, more than one regulatory factor and the two mechanisms described here often underlie the machine's operation. Furthermore, ATPase regulation takes place throughout the motor's cycle, which enables a more complex function than the binary ‘active' and ‘inactive' states. This article is part of a discussion meeting issue ‘Allostery and molecular machines'.

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Li, Dongbo, Walter F. Paxton, Ray H. Baughman, Tony Jun Huang, J. Fraser Stoddart e Paul S. Weiss. "Molecular, Supramolecular, and Macromolecular Motors and Artificial Muscles". MRS Bulletin 34, n.º 9 (setembro de 2009): 671–81. http://dx.doi.org/10.1557/mrs2009.179.

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AbstractRecent developments in chemical synthesis, nanoscale assembly, and molecular-scale measurements enable the extension of the concept of macroscopic machines to the molecular and supramolecular levels. Molecular machines are capable of performing mechanical movements in response to external stimuli. They offer the potential to couple electrical or other forms of energy to mechanical action at the nano- and molecular scales. Working hierarchically and in concert, they can form actuators referred to as artificial muscles, in analogy to biological systems. We describe the principles behind driven motion and assembly at the molecular scale and recent advances in the field of molecular-level electromechanical machines, molecular motors, and artificial muscles. We discuss the challenges and successes in making these assemblies work cooperatively to function at larger scales.

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Beeby, Morgan. "The bacterial flagellar motor and the evolution of molecular machines". Biochemist 40, n.º 2 (1 de abril de 2018): 4–9. http://dx.doi.org/10.1042/bio04002004.

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Understanding how life on earth evolved is an enduringly fascinating and profound question. Relative to our understanding of eukaryotic evolution, however, our understanding of how the molecular machines underpinning life have evolved is poor. The bacterial flagellar motor, which drives a rotary propeller for motility, offers a fascinating case study to explore this further, and is now revealing recurring themes in molecular evolution. This article describes recent discoveries about how flagellar motors have diversified since the first flagellar motor evolved, and what this diversity tells us about molecular evolution.

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Novotný, Filip, Hong Wang e Martin Pumera. "Nanorobots: Machines Squeezed between Molecular Motors and Micromotors". Chem 6, n.º 4 (abril de 2020): 867–84. http://dx.doi.org/10.1016/j.chempr.2019.12.028.

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Novotný, Filip, Hong Wang e Martin Pumera. "Nanorobots: Machines Squeezed between Molecular Motors and Micromotors". Chem 6, n.º 4 (abril de 2020): 1032. http://dx.doi.org/10.1016/j.chempr.2020.02.007.

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Hawthorne, M. Frederick, Bhaskar M. Ramachandran, Robert D. Kennedy e Carolyn B. Knobler. "Approaches to rotary molecular motors". Pure and Applied Chemistry 78, n.º 7 (1 de janeiro de 2006): 1299–304. http://dx.doi.org/10.1351/pac200678071299.

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Interest has recently intensified in the search for molecular motors and actuators capable of delivering useful work to nanodevices under the control of electrochemical or photochemical power sources. While many of these man-made molecular machines are designed to deliver rectilinear motion, very few are proposed for the controlled delivery of rotary motion on the time scale characteristic of intramolecular rearrangements. The adaptation of commo-bis-dicarbollide metallacarborane structures to the possible design and synthesis of such rotary molecular motors is now under investigation. Progress toward this goal will be reported.

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Kolomeisky, Anatoly B. "Motor proteins and molecular motors: how to operate machines at the nanoscale". Journal of Physics: Condensed Matter 25, n.º 46 (7 de outubro de 2013): 463101. http://dx.doi.org/10.1088/0953-8984/25/46/463101.

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Rossmann, Florian M., e Morgan Beeby. "Insights into the evolution of bacterial flagellar motors from high-throughput in situ electron cryotomography and subtomogram averaging". Acta Crystallographica Section D Structural Biology 74, n.º 6 (1 de junho de 2018): 585–94. http://dx.doi.org/10.1107/s2059798318007945.

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In situ structural information on molecular machines can be invaluable in understanding their assembly, mechanism and evolution. Here, the use of electron cryotomography (ECT) to obtain significant insights into how an archetypal molecular machine, the bacterial flagellar motor, functions and how it has evolved is described. Over the last decade, studies using a high-throughput, medium-resolution ECT approach combined with genetics, phylogenetic reconstruction and phenotypic analysis have revealed surprising structural diversity in flagellar motors. Variations in the size and the number of torque-generating proteins in the motor visualized for the first time using ECT has shown that these variations have enabled bacteria to adapt their swimming torque to the environment. Much of the structural diversity can be explained in terms of scaffold structures that facilitate the incorporation of additional motor proteins, and more recent studies have begun to infer evolutionary pathways to higher torque-producing motors. This review seeks to highlight how the emerging power of ECT has enabled the inference of ancestral states from various bacterial species towards understanding how, and `why', flagellar motors have evolved from an ancestral motor to a diversity of variants with adapted or modified functions.

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Credi, Alberto, e Belén Ferrer. "Rotaxane-based molecular machines operated by photoinduced electron transfer". Pure and Applied Chemistry 77, n.º 6 (1 de janeiro de 2005): 1051–57. http://dx.doi.org/10.1351/pac200577061051.

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A molecular machine is an assembly of a definite number of molecular components designed to perform mechanical motions as a result of an appropriate external stimulation. Like their macroscopic counterparts, nanoscale machines need energy to operate. Energy can be supplied through (i) chemical reactions, (ii) electrochemical processes, and (iii) photoinduced processes. Although most molecular motors of the biological world are fueled by chemical reactions, for several reasons light is a very good choice to operate artificial molecular machines. Rotaxanes, owing to their peculiar architecture, are attractive candidates for the construction of artificial nanoscale machines. By adopting an incrementally staged design strategy, photoinduced electron-transfer processes have been engineered within rotaxane-type structures with the purpose of obtaining light-powered molecular machines. Such an approach is illustrated by describing the behavior of prototypes investigated in our laboratories.

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Yanagida, Toshio, Mitsuhiro Iwaki e Yoshiharu Ishii. "Single molecule measurements and molecular motors". Philosophical Transactions of the Royal Society B: Biological Sciences 363, n.º 1500 (13 de março de 2008): 2123–34. http://dx.doi.org/10.1098/rstb.2008.2265.

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Single molecule imaging and manipulation are powerful tools in describing the operations of molecular machines like molecular motors. The single molecule measurements allow a dynamic behaviour of individual biomolecules to be measured. In this paper, we describe how we have developed single molecule measurements to understand the mechanism of molecular motors. The step movement of molecular motors associated with a single cycle of ATP hydrolysis has been identified. The single molecule measurements that have sensitivity to monitor thermal fluctuation have revealed that thermal Brownian motion is involved in the step movement of molecular motors. Several mechanisms have been suggested in different motors to bias random thermal motion to directional movement.

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Balzani, Vincenzo. "Nanoscience and nanotechnology: The bottom-up construction of molecular devices and machines". Pure and Applied Chemistry 80, n.º 8 (1 de janeiro de 2008): 1631–50. http://dx.doi.org/10.1351/pac200880081631.

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The bottom-up approach to miniaturization, which starts from molecules to build up nanostructures, enables the extension of the macroscopic concepts of a device and a machine to molecular level. Molecular-level devices and machines operate via electronic and/or nuclear rearrangements and, like macroscopic devices and machines, need energy to operate and signals to communicate with the operator. Examples of molecular-level photonic wires, plug/socket systems, light-harvesting antennas, artificial muscles, molecular lifts, and light-powered linear and rotary motors are illustrated. The extension of the concepts of a device and a machine to the molecular level is of interest not only for basic research, but also for the growth of nanoscience and the development of nanotechnology.

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HIRATSUKA, Yuichi, e Taro Q. P. UYEDA. "Assembly of Protein Molecular Motors for Nano-Bio-Machines". Seibutsu Butsuri 45, n.º 3 (2005): 134–39. http://dx.doi.org/10.2142/biophys.45.134.

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Newton, D. "Our molecular nature the body's motors, machines and messages". Biochemical Education 25, n.º 2 (abril de 1997): 114. http://dx.doi.org/10.1016/s0307-4412(97)88301-x.

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21

Pfeifer, Lukas, Nong V. Hoang, Maximilian Scherübl, Maxim S. Pshenichnikov e Ben L. Feringa. "Powering rotary molecular motors with low-intensity near-infrared light". Science Advances 6, n.º 44 (outubro de 2020): eabb6165. http://dx.doi.org/10.1126/sciadv.abb6165.

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Light-controlled artificial molecular machines hold tremendous potential to revolutionize molecular sciences as autonomous motion allows the design of smart materials and systems whose properties can respond, adapt, and be modified on command. One long-standing challenge toward future applicability has been the need to develop methods using low-energy, low-intensity, near-infrared light to power these nanomachines. Here, we describe a rotary molecular motor sensitized by a two-photon absorber, which efficiently operates under near-infrared light at intensities and wavelengths compatible with in vivo studies. Time-resolved spectroscopy was used to gain insight into the mechanism of energy transfer to the motor following initial two-photon excitation. Our results offer prospects toward in vitro and in vivo applications of artificial molecular motors.

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Cairns, Bradley R. "Chromatin remodeling machines: similar motors, ulterior motives". Trends in Biochemical Sciences 23, n.º 1 (janeiro de 1998): 20–25. http://dx.doi.org/10.1016/s0968-0004(97)01160-2.

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Lopes, Tiago Drummond, Adroaldo Raizer e Wilson Valente Júnior. "The Use of Digital Twins in Finite Element for the Study of Induction Motors Faults". Sensors 21, n.º 23 (25 de novembro de 2021): 7833. http://dx.doi.org/10.3390/s21237833.

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Induction motors play a key role in the industrial sector. Thus, the correct diagnosis and classification of faults on these machines are important, even in the initial stages of evolution. Such analysis allows for increased productivity, avoids unexpected process interruptions, and prevents damage to machines. Usually, fault diagnosis is carried out by analyzing the characteristic effects caused by the faults. Thus, it is necessary to know and understand the behavior during the operation of the faulty machine. In general, monitoring these characteristics is complex, as it is necessary to acquire signals from the same motor with and without failures for comparison purposes. Whether in an industrial environment or in laboratories, the experimental characterization of failures can become unfeasible for several reasons. Thus, computer simulation of faulty motors digital twins can be an important alternative for failure analysis, especially in large motors. From this perspective, this paper presents and discusses several limitations found in the technical literature that can be minimized with the implementation of digital twins. In addition, a 3D finite element model of an induction motor with broken rotor bars is demonstrated, and motor current signature analysis is used to verify the fault effects. Results are analyzed in the time and frequency domain. Additionally, an artificial neural network of the multilayer perceptron type is used to classify the failure of broken bars in the 3D model rotor.

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Credi, Alberto. "Artificial Molecular Motors Powered by Light". Australian Journal of Chemistry 59, n.º 3 (2006): 157. http://dx.doi.org/10.1071/ch06025.

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The bottom-up construction and operation of machines and motors of molecular size is a topic of great interest in nanoscience, and a fascinating challenge of nanotechnology. The problem of the energy supply to make molecular motors work is of the greatest importance. Research in the last ten years has demonstrated that light energy can indeed be used to power artificial nanomotors by exploiting photochemical processes in appropriately designed systems. More recently, it has become clear that under many aspects light is the best choice to power molecular motors; for example, systems that show autonomous operation and do not generate waste products can be obtained. This review is intended to discuss the design principles at the basis of light-driven artificial nanomotors, and provide an up-to-date overview on the prototype systems that have been developed.

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Dietrich-Buchecker, C. O., M. C. Jimenez-Molero, V. Sartor e J. P. Sauvage. "Rotaxanes and catenanes as prototypes of molecular machines and motors". Pure and Applied Chemistry 75, n.º 10 (1 de janeiro de 2003): 1383–93. http://dx.doi.org/10.1351/pac200375101383.

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In the course of the last 20 years, our view on rotaxanes and catenanes has completely changed. Copper(I)-templated strategies, in particular, have allowed us to prepare catenanes on a real preparative scale, in a few chemical steps from commercially available compounds. A particularly significant improvement was the introduction of the recently developed ring-closing metathesis reaction, using Grubbs catalyst. The dynamic properties of rotaxanes and catenanes has been exploited to construct molecular systems for which one component can be set in motion under the action of an external signal, while the other components can be considered as motionless (artificial molecular “machines ”and “motors ”). A particularly representative example is that of a rotaxane dimer, whose overall length can be controlled chemically: A metal exchange reaction (CuI/ZnII) triggers a reversible contraction/stretching process of the same molecular assembly, in a way reminiscent of the functioning of biological muscles.

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Hiratsuka, Yuichi, Takashi Kamei, Noboru Yumoto e Taro Q. P. Uyeda. "Three approaches to assembling nano-bio-machines using molecular motors". NanoBiotechnology 2, n.º 3-4 (setembro de 2006): 101–15. http://dx.doi.org/10.1007/bf02697265.

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Colasson, Beno�t Xavier, Christiane Dietrich-Buchecker, Maria Consuelo Jimenez-Molero e Jean-Pierre Sauvage. "Towards molecular machines and motors based on transition metal complexes". Journal of Physical Organic Chemistry 15, n.º 8 (2002): 476–83. http://dx.doi.org/10.1002/poc.481.

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Ribetto, Federico D., Sebastián E. Deghi, Hernán L. Calvo e Raúl A. Bustos-Marún. "A dynamical model for Brownian molecular motors driven by inelastic electron tunneling". Journal of Chemical Physics 157, n.º 16 (28 de outubro de 2022): 164102. http://dx.doi.org/10.1063/5.0113504.

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In recent years, several artificial molecular motors driven and controlled by electric currents have been proposed. Similar to Brownian machines, these systems work by turning random inelastic tunneling events into a directional rotation of the molecule. Despite their importance as the ultimate component of future molecular machines, their modeling has not been sufficiently studied. Here, we develop a dynamical model to describe these systems. We illustrate the validity and usefulness of our model by applying it to a well-known molecular motor, showing that the obtained results are consistent with the available experimental data. Moreover, we demonstrate how to use our model to extract some difficult-to-access microscopic parameters. Finally, we include an analysis of the expected effects of current-induced forces (CIFs). Our analysis suggests that, although nonconservative contributions of the CIFs can be important in some scenarios, they do not seem important in the analyzed case. Despite this, the conservative contributions of CIFs could be strong enough to significantly alter the system’s dynamics.

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Priya, Anshu, Dharambir Singh e Nisha. "Role of Molecular Motors in Endosomal Dynamics: A review". Journal of Agriculture Research and Technology 47, n.º 03 (2022): 348–52. http://dx.doi.org/10.56228/jart.2022.47316.

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Molecular motors are continually agitated by random Brownian motion, which provides both challenges and opportunities for energy conversion mechanisms. Molecular motors, an important class of molecular machines, harness various energy sources to generate unidirectional mechanical motion. In biological systems, molecular motors made of proteins and nucleic acids are ubiquitous, and commonly use the chemical energy of ATP or the electrochemical potential of protons across the cell membrane (the so-called proton-motive force) as an energy source. ATP synthase and V-ATPase also act as energy converters, in which ATP chemical energy and proton electrochemical potential are reversibly converted via mechanical rotation. In the cytoplasm of eukaryotic cells, three different classes of motors that generate linear movement are known to exist – myosin, kinesin and dynein. Most motors studied so far in some detail can generate a force that is sufficient to move even large objects through viscous cytoplasm

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Roke, Diederik, Sander J. Wezenberg e Ben L. Feringa. "Molecular rotary motors: Unidirectional motion around double bonds". Proceedings of the National Academy of Sciences 115, n.º 38 (30 de abril de 2018): 9423–31. http://dx.doi.org/10.1073/pnas.1712784115.

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The field of synthetic molecular machines has quickly evolved in recent years, growing from a fundamental curiosity to a highly active field of chemistry. Many different applications are being explored in areas such as catalysis, self-assembled and nanostructured materials, and molecular electronics. Rotary molecular motors hold great promise for achieving dynamic control of molecular functions as well as for powering nanoscale devices. However, for these motors to reach their full potential, many challenges still need to be addressed. In this paper we focus on the design principles of rotary motors featuring a double-bond axle and discuss the major challenges that are ahead of us. Although great progress has been made, further design improvements, for example in terms of efficiency, energy input, and environmental adaptability, will be crucial to fully exploit the opportunities that these rotary motors offer.

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Service, Robert F. "Tiny labmade motors are poised to do useful work". Science 376, n.º 6590 (15 de abril de 2022): 233. http://dx.doi.org/10.1126/science.abq4278.

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NI, CHEN, e JUN-ZHONG WANG. "STM STUDIES ON MOLECULAR ROTORS AND MOTORS". Surface Review and Letters 25, Supp01 (dezembro de 2018): 1841004. http://dx.doi.org/10.1142/s0218625x18410044.

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Molecular motor is a nanoscale machine that consumes energy to produce work via the unidirectional and controlled movement. They are universal in nature and essential to numerous processes of life. When mounted onto solid surfaces, scanning tunneling microscopy (STM) is a powerful technique to characterize the molecular rotors and motors due to the atomic-scale resolution coupled with its ability to track the motion of molecular rotor and motor over time. Moreover, the molecular rotors and motors can be powered by STM tip through injecting tunneling electrons. This review addresses recent advances in the STM studies of the structure, motion, and manipulation of molecular rotors and motors. The developments of surface-mounted azimuthal and altitudinal rotor and motors, large-scale array of molecular rotors, as well as the molecular motors with translational motion will be addressed.

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LIPOWSKY, REINHARD, e ANGELO VALLERIANI. "Editorial: "ACTIVE BIOMIMETIC SYSTEMS: FORCE GENERATION AND CARGO TRANSPORT BY MOLECULAR MACHINES"". Biophysical Reviews and Letters 04, n.º 01n02 (abril de 2009): 1–4. http://dx.doi.org/10.1142/s1793048009000892.

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This special issue of Biophysical Reviews and Letters describes recent advances in the area of active biomimetic systems, which are inspired by the cytoskeletal architecture found in all eukaryotic cells. The main building blocks of these systems are provided by two types of cytoskeletal filaments, F-actin and microtubules, as well as molecular stepping motors such as kinesins and myosins. All of these building blocks represent molecular machines: They are coupled to nucleotide hydrolysis and are able to convert the chemical energy released from this process into mechanical work. Bundles of filaments and teams of stepping motors generate strong pushing forces and perform long-ranged cargo transport.

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Astumian, R. D. "Optical vs. chemical driving for molecular machines". Faraday Discussions 195 (2016): 583–97. http://dx.doi.org/10.1039/c6fd00140h.

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Molecular machines use external energy to drive transport, to do mechanical, osmotic, or electrical work on the environment, and to form structure. In this paper the fundamental difference between the design principles necessary for a molecular machine to use light or external modulation of thermodynamic parameters as an energy sourcevs.the design principle for using an exergonic chemical reaction as a fuel will be explored. The key difference is that for catalytically-driven motors microscopic reversibility must hold arbitrarily far from equilibrium. Applying the constraints of microscopic reversibility assures that a coarse grained model is consistent with an underlying model for motion on a single time-independent potential energy surface. In contrast, light-driven processes, and processes driven by external modulation of the thermodynamic parameters of a system cannot in general be described in terms of motion on a single time-independent potential energy surface, and the rate constants are not constrained by microscopic reversibility. The results presented here call into question the value of the so-called power stroke model as an explanation of the function of autonomous chemically-driven molecular machines such as are commonly found in biology.

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Rodriguez-Franco, V., M. Mañosas e F. Ritort. "Controlled transport by molecular machines: exploring biological motors and their physics". Europhysics News 55, n.º 2 (2024): 20–23. http://dx.doi.org/10.1051/epn/2024208.

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Molecular motors are fascinating biological machines that play a crucial role in a variety of cellular processes, including mass transport, muscle contraction, DNA replication, transcription and repair, and RNA translation. These structures convert chemical energy from adenosine triphosphate (ATP) hydrolysis into mechanical work.

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Ethington, Marirose T. "Our Molecular Nature: The Body's Motors, Machines and Messages.David S. Goodsell". Quarterly Review of Biology 72, n.º 3 (setembro de 1997): 316–17. http://dx.doi.org/10.1086/419870.

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Davey, Megan J., David Jeruzalmi, John Kuriyan e Mike O'Donnell. "Motors and switches: AAA+ machines within the replisome". Nature Reviews Molecular Cell Biology 3, n.º 11 (novembro de 2002): 826–35. http://dx.doi.org/10.1038/nrm949.

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Astumian, R. D. "How molecular motors work – insights from the molecular machinist's toolbox: the Nobel prize in Chemistry 2016". Chemical Science 8, n.º 2 (2017): 840–45. http://dx.doi.org/10.1039/c6sc04806d.

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The Nobel prize in Chemistry for 2016 was awarded to Jean Pierre Sauvage, Sir James Fraser Stoddart, and Bernard (Ben) Feringa for their contributions to the design and synthesis of molecular machines.

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Wagoner, Jason A., e Ken A. Dill. "Opposing Pressures of Speed and Efficiency Guide the Evolution of Molecular Machines". Molecular Biology and Evolution 36, n.º 12 (20 de agosto de 2019): 2813–22. http://dx.doi.org/10.1093/molbev/msz190.

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Abstract Many biomolecular machines need to be both fast and efficient. How has evolution optimized these machines along the tradeoff between speed and efficiency? We explore this question using optimizable dynamical models along coordinates that are plausible evolutionary degrees of freedom. Data on 11 motors and ion pumps are consistent with the hypothesis that evolution seeks an optimal balance of speed and efficiency, where any further small increase in one of these quantities would come at great expense to the other. For FoF1-ATPases in different species, we also find apparent optimization of the number of subunits in the c-ring, which determines the number of protons pumped per ATP synthesized. Interestingly, these ATPases appear to more optimized for efficiency than for speed, which can be rationalized through their key role as energy transducers in biology. The present modeling shows how the dynamical performance properties of biomolecular motors and pumps may have evolved to suit their corresponding biological actions.

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Colasson, Benoit Xavier, Christiane Dietrich-Buchecker, Maria Consuelo Jimenez-Molero e Jean-Pierre Sauvage. "ChemInform Abstract: Towards Molecular Machines and Motors Based on Transition Metal Complexes". ChemInform 33, n.º 51 (18 de maio de 2010): no. http://dx.doi.org/10.1002/chin.200251267.

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Sauvage, Jean-Pierre. "ChemInform Abstract: Rotaxanes and Catenanes in Motion: Towards Molecular Machines and Motors". ChemInform 30, n.º 21 (15 de junho de 2010): no. http://dx.doi.org/10.1002/chin.199921290.

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Okazaki, Kei-ichi, e Gerhard Hummer. "Elasticity, friction, and pathway of γ-subunit rotation in FoF1-ATP synthase". Proceedings of the National Academy of Sciences 112, n.º 34 (10 de agosto de 2015): 10720–25. http://dx.doi.org/10.1073/pnas.1500691112.

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We combine molecular simulations and mechanical modeling to explore the mechanism of energy conversion in the coupled rotary motors of FoF1-ATP synthase. A torsional viscoelastic model with frictional dissipation quantitatively reproduces the dynamics and energetics seen in atomistic molecular dynamics simulations of torque-driven γ-subunit rotation in the F1-ATPase rotary motor. The torsional elastic coefficients determined from the simulations agree with results from independent single-molecule experiments probing different segments of the γ-subunit, which resolves a long-lasting controversy. At steady rotational speeds of ∼1 kHz corresponding to experimental turnover, the calculated frictional dissipation of less than kBT per rotation is consistent with the high thermodynamic efficiency of the fully reversible motor. Without load, the maximum rotational speed during transitions between dwells is reached at ∼1 MHz. Energetic constraints dictate a unique pathway for the coupled rotations of the Fo and F1 rotary motors in ATP synthase, and explain the need for the finer stepping of the F1 motor in the mammalian system, as seen in recent experiments. Compensating for incommensurate eightfold and threefold rotational symmetries in Fo and F1, respectively, a significant fraction of the external mechanical work is transiently stored as elastic energy in the γ-subunit. The general framework developed here should be applicable to other molecular machines.

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Kafeel, Ayaz, Sumair Aziz, Muhammad Awais, Muhammad Attique Khan, Kamran Afaq, Sahar Ahmed Idris, Hammam Alshazly e Samih M. Mostafa. "An Expert System for Rotating Machine Fault Detection Using Vibration Signal Analysis". Sensors 21, n.º 22 (15 de novembro de 2021): 7587. http://dx.doi.org/10.3390/s21227587.

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Accurate and early detection of machine faults is an important step in the preventive maintenance of industrial enterprises. It is essential to avoid unexpected downtime as well as to ensure the reliability of equipment and safety of humans. In the case of rotating machines, significant information about machine’s health and condition is present in the spectrum of its vibration signal. This work proposes a fault detection system of rotating machines using vibration signal analysis. First, a dataset of 3-dimensional vibration signals is acquired from large induction motors representing healthy and faulty states. The signal conditioning is performed using empirical mode decomposition technique. Next, multi-domain feature extraction is done to obtain various combinations of most discriminant temporal and spectral features from the denoised signals. Finally, the classification step is performed with various kernel settings of multiple classifiers including support vector machines, K-nearest neighbors, decision tree and linear discriminant analysis. The classification results demonstrate that a hybrid combination of time and spectral features, classified using support vector machines with Gaussian kernel achieves the best performance with 98.2% accuracy, 96.6% sensitivity, 100% specificity and 1.8% error rate.

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Goychuk, Igor. "Molecular machines operating on the nanoscale: from classical to quantum". Beilstein Journal of Nanotechnology 7 (3 de março de 2016): 328–50. http://dx.doi.org/10.3762/bjnano.7.31.

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The main physical features and operating principles of isothermal nanomachines in the microworld, common to both classical and quantum machines, are reviewed. Special attention is paid to the dual, constructive role of dissipation and thermal fluctuations, the fluctuation–dissipation theorem, heat losses and free energy transduction, thermodynamic efficiency, and thermodynamic efficiency at maximum power. Several basic models are considered and discussed to highlight generic physical features. This work examines some common fallacies that continue to plague the literature. In particular, the erroneous beliefs that one should minimize friction and lower the temperature for high performance of Brownian machines, and that the thermodynamic efficiency at maximum power cannot exceed one-half are discussed. The emerging topic of anomalous molecular motors operating subdiffusively but very efficiently in the viscoelastic environment of living cells is also discussed.

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Lavelle, Christophe, Elise Praly, David Bensimon, Eric Le Cam e Vincent Croquette. "Nucleosome-remodelling machines and other molecular motors observed at the single-molecule level". FEBS Journal 278, n.º 19 (8 de setembro de 2011): 3596–607. http://dx.doi.org/10.1111/j.1742-4658.2011.08280.x.

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Sauvage, Jean-Pierre. "Transition Metal-Containing Rotaxanes and Catenanes in Motion: Toward Molecular Machines and Motors". Accounts of Chemical Research 31, n.º 10 (outubro de 1998): 611–19. http://dx.doi.org/10.1021/ar960263r.

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Rapenne, Gw�na�l. "Synthesis of technomimetic molecules: towards rotation control in single-molecular machines and motors". Organic & Biomolecular Chemistry 3, n.º 7 (2005): 1165. http://dx.doi.org/10.1039/b419282f.

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Harris, Jared D., Mark J. Moran e Ivan Aprahamian. "New molecular switch architectures". Proceedings of the National Academy of Sciences 115, n.º 38 (16 de julho de 2018): 9414–22. http://dx.doi.org/10.1073/pnas.1714499115.

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In this paper we elaborate on recently developed molecular switch architectures and how these new systems can help with the realization of new functions and advancement of artificial molecular machines. Progress in chemically and photoinduced switches and motors is summarized and contextualized such that the reader may gain an appreciation for the novel tools that have come about in the past decade. Many of these systems offer distinct advantages over commonly employed switches, including improved fidelity, addressability, and robustness. Thus, this paper serves as a jumping-off point for researchers seeking new switching motifs for specific applications, or ones that address the limitations of presently available systems.

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Ariga, Katsuhiko. "Confined Space Nanoarchitectonics for Dynamic Functions and Molecular Machines". Micromachines 15, n.º 2 (17 de fevereiro de 2024): 282. http://dx.doi.org/10.3390/mi15020282.

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Nanotechnology has advanced the techniques for elucidating phenomena at the atomic, molecular, and nano-level. As a post nanotechnology concept, nanoarchitectonics has emerged to create functional materials from unit structures. Consider the material function when nanoarchitectonics enables the design of materials whose internal structure is controlled at the nanometer level. Material function is determined by two elements. These are the functional unit that forms the core of the function and the environment (matrix) that surrounds it. This review paper discusses the nanoarchitectonics of confined space, which is a field for controlling functional materials and molecular machines. The first few sections introduce some of the various dynamic functions in confined spaces, considering molecular space, materials space, and biospace. In the latter two sections, examples of research on the behavior of molecular machines, such as molecular motors, in confined spaces are discussed. In particular, surface space and internal nanospace are taken up as typical examples of confined space. What these examples show is that not only the central functional unit, but also the surrounding spatial configuration is necessary for higher functional expression. Nanoarchitectonics will play important roles in the architecture of such a total system.

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Deguchi, Takahiro, Malina K. Iwanski, Eva-Maria Schentarra, Christopher Heidebrecht, Lisa Schmidt, Jennifer Heck, Tobias Weihs et al. "Direct observation of motor protein stepping in living cells using MINFLUX". Science 379, n.º 6636 (10 de março de 2023): 1010–15. http://dx.doi.org/10.1126/science.ade2676.

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Dynamic measurements of molecular machines can provide invaluable insights into their mechanism, but these measurements have been challenging in living cells. Here, we developed live-cell tracking of single fluorophores with nanometer spatial and millisecond temporal resolution in two and three dimensions using the recently introduced super-resolution technique MINFLUX. Using this approach, we resolved the precise stepping motion of the motor protein kinesin-1 as it walked on microtubules in living cells. Nanoscopic tracking of motors walking on the microtubules of fixed cells also enabled us to resolve the architecture of the microtubule cytoskeleton with protofilament resolution.

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