Artificially Controllable Nanodevices Constructed By Dna Origami Technology

Download Artificially Controllable Nanodevices Constructed By Dna Origami Technology full books in PDF, epub, and Kindle. Read online Artificially Controllable Nanodevices Constructed By Dna Origami Technology ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!

Artificially Controllable Nanodevices Constructed by DNA Origami Technology

Author : Yangyang Yang
Publisher : Springer
ISBN 13 : 4431557695
Total Pages : 82 pages
Book Rating : 4.4/5 (315 download)

DOWNLOAD NOW!

Book Synopsis Artificially Controllable Nanodevices Constructed by DNA Origami Technology by : Yangyang Yang

Download or read book Artificially Controllable Nanodevices Constructed by DNA Origami Technology written by Yangyang Yang and published by Springer. This book was released on 2015-12-16 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this book, the author deals mainly with two topics: (1) single-molecule visualization of switching behaviors in the DNA nanoframe system utilizing different kinds of molecular switches through the use of high-speed atomic force microscope (AFM); (2) construction of photocontrollable DNA nanostructures in programmed patterns and direct visualization of the dynamic assembling process. Here, high-speed AFM was employed to observe the dynamic movements of single molecules. Compared to a traditional single-molecule analysis method, such as fluorescence spectroscopy or electron microscopy, high-speed AFM makes possible the real-time observation of molecule behaviors. DNA nanostructures were designed and assembled as scaffolds to incorporate interested biomolecules. The observations were carried out under robust conditions without complicated pretreatment. Moreover, the photoresponsive molecules were successfully assembled into around 100 nm-sized DNA nanostructures. The assembly/disassembly of nanostructures can be regulated reversibly by photoirradiation. This book explains how DNA origami has gradually become a useful tool for the investigation of biochemical interactions in defined nanospace. It also shows the possibility of DNA nanostructures acting as nanodevices for application in biological systems, serving as a good introduction to basic DNA nanotechnology.

Structural DNA Nanotechnology

Author : Nadrian C. Seeman
Publisher : Cambridge University Press
ISBN 13 : 0521764483
Total Pages : 269 pages
Book Rating : 4.5/5 (217 download)

DOWNLOAD NOW!

Book Synopsis Structural DNA Nanotechnology by : Nadrian C. Seeman

Download or read book Structural DNA Nanotechnology written by Nadrian C. Seeman and published by Cambridge University Press. This book was released on 2015 with total page 269 pages. Available in PDF, EPUB and Kindle. Book excerpt: Written by the founder of the field, this is a comprehensive and accessible introduction to structural DNA nanotechnology.

DNA Origami

Author : Masayuki Endo
Publisher : John Wiley & Sons
ISBN 13 : 1119682584
Total Pages : 436 pages
Book Rating : 4.1/5 (196 download)

DOWNLOAD NOW!

Book Synopsis DNA Origami by : Masayuki Endo

Download or read book DNA Origami written by Masayuki Endo and published by John Wiley & Sons. This book was released on 2022-05-05 with total page 436 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA ORIGAMI Discover the impact and multidisciplinary applications of this subfield of DNA nanotechnology DNA origami refers to the technique of assembling single-stranded DNA template molecules into target two- and three-dimensional shapes at the nanoscale. This is accomplished by annealing templates with hundreds of DNA strands and then binding them through the specific base-pairing of complementary bases. The inherent properties of these DNA molecules—molecular recognition, self-assembly, programmability, and structural predictability—has given rise to intriguing applications from drug delivery systems to uses in circuitry in plasmonic devices. The first book to examine this important subfield, DNA Origami brings together leading experts from all fields to explain the current state and future directions of this cutting-edge avenue of study. The book begins by providing a detailed examination of structural design and assembly systems and their applications. As DNA origami technology is growing in popularity in the disciplines of chemistry, materials science, physics, biophysics, biology, and medicine, interdisciplinary studies are classified and discussed in detail. In particular, the book focuses on DNA origami used for creating new functional materials (combining chemistry and materials science; DNA origami for single-molecule analysis and measurements (as applied in physics and biophysics); and DNA origami for biological detection, diagnosis and therapeutics (medical and biological applications). DNA Origami readers will also find: A complete guide for newcomers that brings together fundamental and developmental aspects of DNA origami technology Contributions by a leading team of experts that bring expert views from different angles of the structural developments and applications of DNA origami An emerging and impactful research topic that will be of interest in numerous multidisciplinary areas A helpful list of references provided at the end of each chapter to give avenues for further study Given the wide scope found in this groundbreaking work, DNA Origami is a perfect resource for nanotechnologists, biologists, biophysicists, chemists, materials scientists, medical scientists, and pharmaceutical researchers.

DNA in Supramolecular Chemistry and Nanotechnology

Author : Eugen Stulz
Publisher : John Wiley & Sons
ISBN 13 : 1118696867
Total Pages : 538 pages
Book Rating : 4.1/5 (186 download)

DOWNLOAD NOW!

Book Synopsis DNA in Supramolecular Chemistry and Nanotechnology by : Eugen Stulz

Download or read book DNA in Supramolecular Chemistry and Nanotechnology written by Eugen Stulz and published by John Wiley & Sons. This book was released on 2015-09-28 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers the emerging topic of DNA nanotechnology and DNA supramolecular chemistry in its broader sense. By taking DNA out of its biological role, this biomolecule has become a very versatile building block in materials chemistry, supramolecular chemistry and bio-nanotechnology. Many novel structures have been realized in the past decade, which are now being used to create molecular machines, drug delivery systems, diagnosis platforms or potential electronic devices. The book combines many aspects of DNA nanotechnology, including formation of functional structures based on covalent and non-covalent systems, DNA origami, DNA based switches, DNA machines, and alternative structures and templates. This broad coverage is very appealing since it combines both the synthesis of modified DNA as well as designer concepts to successfully plan and make DNA nanostructures. Contributing authors have provided first a general introduction for the non-specialist reader, followed by a more in-depth analysis and presentation of their topic. In this way the book is attractive and useful for both the non-specialist who would like to have an overview of the topic, as well as the specialist reader who requires more information and inspiration to foster their own research.

RNA Nanotechnology

Author : Bin Wang
Publisher : CRC Press
ISBN 13 : 9814411647
Total Pages : 468 pages
Book Rating : 4.8/5 (144 download)

DOWNLOAD NOW!

Book Synopsis RNA Nanotechnology by : Bin Wang

Download or read book RNA Nanotechnology written by Bin Wang and published by CRC Press. This book was released on 2014-04-02 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the past few decades there has been incredible growth in "bionano"-related research, which has been accompanied by numerous publications in this field. Although various compilations address topics related to deoxyribonucleic acid (DNA) and protein, there are few books that focus on determining the structure of ribonucleic acid (RNA) and using RNA as building blocks to construct nanoarchitectures for biomedical and healthcare applications. RNA Nanotechnology is a comprehensive volume that details both the traditional approaches and the latest developments in the field of RNA-related technology. This book targets a wide audience: a broad introduction provides a solid academic background for students, researchers, and scientists who are unfamiliar with the subject, while the in-depth descriptions and discussions are useful for advanced professionals. The book opens with reviews on the basic aspects of RNA biology, computational approaches for predicting RNA structures, and traditional and emerging experimental approaches for probing RNA structures. This section is followed by explorations of the latest research and discoveries in RNA nanotechnology, including the design and construction of RNA-based nanostructures. The final segment of the book includes descriptions and discussions of the potential biological and therapeutic applications of small RNA molecules, such as small/short interfering RNAs (siRNAs), microRNAs (miRNAs), RNA aptamers, and ribozymes.

Artificial Intelligence in the Age of Nanotechnology

Author : Jaber, Wassim
Publisher : IGI Global
ISBN 13 :
Total Pages : 313 pages
Book Rating : 4.3/5 (693 download)

DOWNLOAD NOW!

Book Synopsis Artificial Intelligence in the Age of Nanotechnology by : Jaber, Wassim

Download or read book Artificial Intelligence in the Age of Nanotechnology written by Jaber, Wassim and published by IGI Global. This book was released on 2023-12-07 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the world of academia, scholars and researchers are confronted with a rapidly expanding knowledge base in Artificial Intelligence (AI) and nanotechnology. The integration of these two groundbreaking fields presents an intricate web of concepts, innovations, and interdisciplinary applications that can overwhelm even the most astute academic minds. Staying up to date with the latest developments and effectively navigating this complex terrain has become a pressing challenge for those striving to contribute meaningfully to these fields. Artificial Intelligence in the Age of Nanotechnology is a transformative solution meticulously crafted to address the academic community's knowledge gaps and challenges. This comprehensive book serves as the guiding light for scholars, researchers, and students grappling with the dynamic synergy between AI and Nanotechnology. It offers a structured and authoritative exploration of the core principles and transformative applications of these domains across diverse fields. By providing clarity and depth, it empowers academics to stay at the forefront of innovation and make informed contributions.

Comprehensive Nanoscience and Nanotechnology

Author :
Publisher : Academic Press
ISBN 13 : 012812296X
Total Pages : 1881 pages
Book Rating : 4.1/5 (281 download)

DOWNLOAD NOW!

Book Synopsis Comprehensive Nanoscience and Nanotechnology by :

Download or read book Comprehensive Nanoscience and Nanotechnology written by and published by Academic Press. This book was released on 2019-01-02 with total page 1881 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Nanoscience and Technology, Second Edition, Five Volume Set allows researchers to navigate a very diverse, interdisciplinary and rapidly-changing field with up-to-date, comprehensive and authoritative coverage of every aspect of modern nanoscience and nanotechnology. Presents new chapters on the latest developments in the field Covers topics not discussed to this degree of detail in other works, such as biological devices and applications of nanotechnology Compiled and written by top international authorities in the field

Advanced Theranostic Materials

Author : Ashutosh Tiwari
Publisher : John Wiley & Sons
ISBN 13 : 1118998898
Total Pages : 360 pages
Book Rating : 4.1/5 (189 download)

DOWNLOAD NOW!

Book Synopsis Advanced Theranostic Materials by : Ashutosh Tiwari

Download or read book Advanced Theranostic Materials written by Ashutosh Tiwari and published by John Wiley & Sons. This book was released on 2015-07-10 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book is covers the recent advances in the development on the regulation of such theragnosis system and their biomedical perspectives to act as a future nanomedicine. Advanced Theranostics Materialsis written by a distinguished group of contributors and provides comprehensive coverage of the current literature, up-to-date overview of all aspects of advanced theranostics materials ranging from system biology, diagnostics, imaging, image-guided therapy, therapeutics, biosensors, and translational medicine and personalized medicine, as well as the much broader task of covering most topics of biomedical research. The books focusses on the following topics: Part 1: System biology and translational medicine Aberrant Signaling Pathways: Hallmark of Cancer Cells and Target for Nanotherapeutics Application of Nanoparticles in Cancer Treatment Biomacromolecule-Gated Mesoporous Silica Drug Delivery Systems Construction of Functional DNA Nanostructures for Theranostic Applications Smart Polypeptide Nanocarriers for Malignancy Therapeutics Part 2: Imaging and therapeutics Dimercaptosuccinic acid-coated magnetic nanoparticles as a localized delivery system in cancer immunotherapy Cardiovascular nanomedicine Chitosan-based systems for sustained drug release Nanocapsules in biomedicine: promises and challenges Chitosan-based polyelectrolyte complexes: characteristics and application in formulation of particulate drug carriers Part 3: Diagnostics and featured prognostics Non-invasive Glucose Biosensors based on Nanomaterials Self/directed Assembly of Nanoparticles: A review on various approaches Ion exchangers – an open window for the development of advanced materials with pharmaceutical and medical applications New Titanium Alloys for Biomedical Applications

Computational Intelligence and Intelligent Systems

Author : Kangshun Li
Publisher : Springer
ISBN 13 : 9811316511
Total Pages : 578 pages
Book Rating : 4.8/5 (113 download)

DOWNLOAD NOW!

Book Synopsis Computational Intelligence and Intelligent Systems by : Kangshun Li

Download or read book Computational Intelligence and Intelligent Systems written by Kangshun Li and published by Springer. This book was released on 2018-07-20 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: This two-volume set (CCIS 873 and CCIS 874) constitutes the thoroughly refereed proceedings of the 9th International Symposium, ISICA 2017, held in Guangzhou, China, in November 2017. The 101 full papers presented in both volumes were carefully reviewed and selected from 181 submissions. This second volume is organized in topical sections on swarm intelligence: cooperative Search, swarm optimization; complex systems modeling: system dynamic, multimedia simulation; intelligent information systems: information retrieval, e-commerce platforms; artificial intelligence and robotics: query optimization, intelligent engineering; virtualization: motion-based tracking, image recognition.

Polymeric Nanomaterials in Nanotherapeutics

Author :
Publisher : Elsevier
ISBN 13 : 0128139331
Total Pages : 561 pages
Book Rating : 4.1/5 (281 download)

DOWNLOAD NOW!

Book Synopsis Polymeric Nanomaterials in Nanotherapeutics by :

Download or read book Polymeric Nanomaterials in Nanotherapeutics written by and published by Elsevier. This book was released on 2018-10-26 with total page 561 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymeric Nanomaterials in Nanotherapeutics describes how polymeric nanosensors and nanorobotics are used for biomedical instrumentation, surgery, diagnosis and targeted drug delivery for cancer, pharmacokinetics, monitoring of diabetes and healthcare. Key areas of coverage include drug administration and formulations for targeted delivery and release of active agents (drug molecules) to non-healthy tissues and cells. The book demonstrates how these are applied to dental work, wound healing, cancer, cardiovascular diseases, neurodegenerative disorders, infectious diseases, chronic inflammatory diseases, metabolic diseases, and more. Methods of administration discussed include oral, dental, topical and transdermal, pulmonary and nasal, ocular, vaginal, and brain drug delivery and targeting. Drug delivery topics treated in several subchapters includes materials for active targeting and cases study of polymeric nanomaterials in clinical trials. The toxicity and regulatory status of therapeutic polymeric nanomaterials are also examined. The book gives a broad perspective on the topic for researchers, postgraduate students and professionals in the biomaterials, biotechnology, and biomedical fields. - Shows how the properties of polymeric nanomaterials can be used to create more efficient medical treatments/therapies - Demonstrates the potential and range of applications of polymeric nanomaterials in disease prevention, diagnosis, drug development, and for improving treatment outcomes - Accurately explains how nanotherapeutics can help in solving problems in the field through the latest technologies and formulations

Nanophotonics and Plasmonics

Author : Dr. Ching Eng (Jason) Png
Publisher : CRC Press
ISBN 13 : 1351649108
Total Pages : 570 pages
Book Rating : 4.3/5 (516 download)

DOWNLOAD NOW!

Book Synopsis Nanophotonics and Plasmonics by : Dr. Ching Eng (Jason) Png

Download or read book Nanophotonics and Plasmonics written by Dr. Ching Eng (Jason) Png and published by CRC Press. This book was released on 2017-08-21 with total page 570 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a first integrated view of nanophotonics and plasmonics, covering the use of dielectric, semiconductor, and metal nanostructures to manipulate light at the nanometer scale. The presentation highlights similarities and advantages, and shows the common underlying physics, targets, and methodologies used for different materials (optically transparent materials for nanophotonics, vs opaque materials for plasmonics). Ultimately, the goal is to provide a basis for developing a unified platform for both fields. In addition to the fundamentals and detailed theoretical background, the book showcases the main device applications. Ching Eng (Jason) Png is Director of the Electronics and Photonics Department at the Institute of High Performance Computing, Agency for Science Technology and Research, Singapore. Yuriy A. Akimov is a scientist in the Electronics and Photonics Department at the Institute of High Performance Computing, Agency for Science Technology and Research, Singapore.

Functional and Smart Materials

Author : Chander Prakash
Publisher : CRC Press
ISBN 13 : 1000193152
Total Pages : 239 pages
Book Rating : 4.0/5 (1 download)

DOWNLOAD NOW!

Book Synopsis Functional and Smart Materials by : Chander Prakash

Download or read book Functional and Smart Materials written by Chander Prakash and published by CRC Press. This book was released on 2020-10-25 with total page 239 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a comprehensive and broad-spectrum picture of the state-of-the-art research, development, and commercial prospective of various discoveries conducted in the real world of functional and smart materials. This book presents various synthesis and fabrication routes of function and smart materials for universal applications such as material science, mechanical engineering, manufacturing, metrology, nanotechnology, physics, biology, chemistry, civil engineering, and food science. The content of this book opens various scientific horizons proved to be beneficial for uplifting the standards of day-to-day practices in the biomedical domain. Myriad innovations in the materials science and engineering are transforming our everyday lives in extraordinary ways. This book captures the emerging areas of materials science and advanced manufacturing engineering and presents recent trends in research for researchers, field engineers, and academic professionals.

Chiral Nanomaterials

Author : Zhiyong Tang
Publisher : John Wiley & Sons
ISBN 13 : 3527337571
Total Pages : 300 pages
Book Rating : 4.5/5 (273 download)

DOWNLOAD NOW!

Book Synopsis Chiral Nanomaterials by : Zhiyong Tang

Download or read book Chiral Nanomaterials written by Zhiyong Tang and published by John Wiley & Sons. This book was released on 2018-03-05 with total page 300 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thorough and up-to-date, this book presents recent developments in this exciting research field. To begin with, the text covers the fabrication of chiral nanomaterials via various synthesis methods, including electron beam lithography, ion beam etching, chemical synthesis and biological DNA directed assembly. This is followed by the relevant theory and reaction mechanisms, with a discussion of the characterization of chiral nanomaterials according to the optical properties of metal nanoparticles, semiconductor nanocrystals, and nanoclusters. The whole is rounded off by a summary of applications in the field of catalysis, sensors, and biomedicine. With its comprehensive yet concise coverage of the whole spectrum of research, this is invaluable reading for senior researchers and entrants to the field of nanoscience and materials science.

Protein Self-Assembly

Author : Jennifer J. McManus
Publisher : Humana
ISBN 13 : 9781493996803
Total Pages : 266 pages
Book Rating : 4.9/5 (968 download)

DOWNLOAD NOW!

Book Synopsis Protein Self-Assembly by : Jennifer J. McManus

Download or read book Protein Self-Assembly written by Jennifer J. McManus and published by Humana. This book was released on 2020-08-08 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume explores experimental and computational approaches to measuring the most widely studied protein assemblies, including condensed liquid phases, aggregates, and crystals. The chapters in this book are organized into three parts: Part One looks at the techniques used to measure protein-protein interactions and equilibrium protein phases in dilute and concentrated protein solutions; Part Two describes methods to measure kinetics of aggregation and to characterize the assembled state; and Part Three details several different computational approaches that are currently used to help researchers understand protein self-assembly. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Thorough and cutting-edge, Protein Self-Assembly: Methods and Protocols is a valuable resource for researchers who are interested in learning more about this developing field.

DNA Nanotechnology

Author : Chunhai Fan
Publisher : Springer Science & Business Media
ISBN 13 : 3642360777
Total Pages : 361 pages
Book Rating : 4.6/5 (423 download)

DOWNLOAD NOW!

Book Synopsis DNA Nanotechnology by : Chunhai Fan

Download or read book DNA Nanotechnology written by Chunhai Fan and published by Springer Science & Business Media. This book was released on 2013-03-12 with total page 361 pages. Available in PDF, EPUB and Kindle. Book excerpt: DNA nanotechnology: From structure to function presents an overview of various facets of DNA nanotechnology, with a particular focus on their promising applications. This book is composed of three parts. Part I, Elements of DNA Nanotechnology, provides extensive basic information on DNA nanotechnology. Part II, Static and Dynamic DNA Nanotechnology, describes the design and fabrication of static and dynamic DNA nanostructures. Recent advances in DNA origami, DNA walkers and DNA nanodevices are all covered in this part. Part III, Applications of DNA Nanotechnology, introduces a variety of applications of DNA nanotechnology, including biosensing, computation, drug delivery, etc. Together these provide a comprehensive overview of this emerging area and its broad impact on biological and medical sciences. This book is intended for post-graduates, post-doctoral researchers and research scientists who are interested in expanding their knowledge of DNA nanotechnology. It provides readers an impression of the latest developments in this exciting filed.

Materials Nanoarchitectonics

Author : Katsuhiko Ariga
Publisher : Elsevier
ISBN 13 : 0323994733
Total Pages : 648 pages
Book Rating : 4.3/5 (239 download)

DOWNLOAD NOW!

Book Synopsis Materials Nanoarchitectonics by : Katsuhiko Ariga

Download or read book Materials Nanoarchitectonics written by Katsuhiko Ariga and published by Elsevier. This book was released on 2023-12-07 with total page 648 pages. Available in PDF, EPUB and Kindle. Book excerpt: Materials Nanoarchitectonics: From Integrated Molecular Systems to Advanced Devices provides the latest information on the design and molecular manipulation of self-organized hierarchically structured systems using tailor-made nanoscale materials as structural and functional units. The book is organized into three main sections that focus on molecular design of building blocks and hybrid materials, formation of nanostructures, and applications and devices. Bringing together emerging materials, synthetic aspects, nanostructure strategies, and applications, the book aims to support further progress, by offering different perspectives and a strong interdisciplinary approach to this rapidly growing area of innovation. This is an extremely valuable resource for researchers, advanced students, and scientists in industry, with an interest in nanoarchitectonics, nanostructures, and nanomaterials, or across the areas of nanotechnology, chemistry, surface science, polymer science, electrical engineering, physics, chemical engineering, and materials science. - Offers a nanoarchitectonic perspective on emerging fields, such as metal-organic frameworks, porous polymer materials, or biomimetic nanostructures - Discusses different approaches to utilizing "soft chemistry" as a source for hierarchically organized materials - Offers an interdisciplinary approach to the design and construction of integrated chemical nano systems - Discusses novel approaches towards the creation of complex multiscale architectures

Macrocyclic and Supramolecular Chemistry

Author : Reed M. Izatt
Publisher : John Wiley & Sons
ISBN 13 : 1119053846
Total Pages : 501 pages
Book Rating : 4.1/5 (19 download)

DOWNLOAD NOW!

Book Synopsis Macrocyclic and Supramolecular Chemistry by : Reed M. Izatt

Download or read book Macrocyclic and Supramolecular Chemistry written by Reed M. Izatt and published by John Wiley & Sons. This book was released on 2016-08-01 with total page 501 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book commemorates the 25th anniversary of the International Izatt-Christensen Award in Macrocyclic and Supramolecular Chemistry. The award, one of the most prestigious of small awards in chemistry, recognizes excellence in the developing field of macrocyclic and supramolecular chemistry Macrocyclic and Supramolecular Chemistry: How Izatt-Christensen Award Winners Shaped the Field features chapters written by the award recipients who provide unique perspectives on the spectacular growth in these expanding and vibrant fields of chemistry over the past half century, and on the role of these awardees in shaping this growth. During this time there has been an upsurge of interest in the design, synthesis and characterization of increasingly more complex macrocyclic ligands and in the application of this knowledge to understanding molecular recognition processes in host-guest chemistry in ways that were scarcely envisioned decades earlier. In October 2016, Professor Jean-Pierre Sauvage and Sir J. Fraser Stoddart (author for chapter 22 "Contractile and Extensile Molecular Systems: Towards Molecular Muscles" by Jean -Pierre Sauvage, Vincent Duplan, and Frédéric Niess and 20 "Serendipity" by Paul R. McGonigal and J. Fraser Stoddart respectively) were awarded the Nobel Prize in Chemistry alongside fellow Wiley author Bernard Feringa, for the design and synthesis of molecular machines.