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Books > Science & Mathematics > Physics > Applied physics & special topics > Biophysics
There is a growing need in both industrial and academic research to obtain accurate quantitative results from continuous wave (CW) electron paramagnetic resonance (EPR) experiments. This book describes various sample-related, instrument-related and software-related aspects of obtaining quantitative results from EPR expe- ments. Some speci?c items to be discussed include: selection of a reference standard, resonator considerations (Q, B, B ), power saturation, sample position- 1 m ing, and ?nally, the blending of all the factors together to provide a calculation model for obtaining an accurate spin concentration of a sample. This book might, at ?rst glance, appear to be a step back from some of the more advanced pulsed methods discussed in recent EPR texts, but actually quantitative "routine CW EPR" is a challenging technique, and requires a thorough understa- ing of the spectrometer and the spin system. Quantitation of CW EPR can be subdivided into two main categories: (1) intensity and (2) magnetic ?eld/mic- wave frequency measurement. Intensity is important for spin counting. Both re- tive intensity quantitation of EPR samples and their absolute spin concentration of samples are often of interest. This information is important for kinetics, mechanism elucidation, and commercial applications where EPR serves as a detection system for free radicals produced in an industrial process. It is also important for the study of magnetic properties. Magnetic ?eld/microwave frequency is important for g and nuclear hyper?ne coupling measurements that re?ect the electronic structure of the radicals or metal ions.
There are probably few people who do not dream of the good old times, when do ing science often meant fascination, excitement, even adventure. In our time, do ing science involves often technology and, perhaps, even business. But there are still niches where curiosity and fascination have their place. The subject of this book, technological as its title may sound, is one of the fortunate examples. It will report on lasers generating the coldest places in the Universe, and on table top laser microtools which can produce a heat "inferno" as it prevails in the interior of the Sun, or simulate, for specific plant cells, microgravity of the space around our plan et Earth. There will be some real surprises for the reader. The applications range from basic studies of the driving forces of cell division (and thus life) via genetic modification of cells (for example, for plant breeding) to medical applications such as blood cell analysis and finally in vitro fertilization. What are these instruments: laser microbeams and optical tweezers? Both are lasers coupled with a fluorescence microscope. The laser microbeam uses a pulsed ultraviolet laser. Light is focused, as well as possible, in space and time, in order to obtain extremely high light intensities - high enough to generate, for a very short instant, extremely hot spots which can be used to cut, fuse or perforate biological material."
A reissue of a classic book -- corrected, edited, typeset, redrawn, and indexed for the Biological Physics Series. In- tended for undergraduate courses in biophysics, biological physics, physiology, medical physics, and biomedical engineering, this is an introduction to statistical physics with examples and problems from the medical and biological sciences. Topics include the elements of the theory of probability, Poisson statistics, thermal equilibrium, entropy and free energy, and the second law of thermodynamics. It can be used as a supplement to standard introductory physics courses, and as a text for medical schools, medical physics courses, and biology departments. The three volumes combined present all the major topics in physics. These books are being reissued in response to frequent requests to satisfy the growing need among students and practitioners in the medical and biological sciences with a working knowledge of the physical sciences. The books are also in demand in physics departments either as supplements to traditional intro texts or as a main text for those departments offering courses with biological or medical physics orientation.
This book provides a molecular view of membrane transport by means of numerous biochemical and biophysical techniques. The rapidly growing numbers of atomic structures of transporters in different conformations and the constant progress in bioinformatics have recently added deeper insights.The unifying mechanism of energized solute transport across membranes is assumed to consist of the conformational cycling of a carrier protein to provide access to substrate binding sites from either side of a cellular membrane. Due to the central role of active membrane transport there is considerable interest in deciphering the principles of one of the most fundamental processes in nature: the alternating access mechanism.This book brings together particularly significant structure-function studies on a variety of carrier systems from different transporter families: Glutamate symporters, LeuT-like fold transporters, MFS transporters and SMR (RND) exporters, as well as ABC-type importers.The selected examples impressively demonstrate how the combination of functional analysis, crystallography, investigation of dynamics and computational studies has made it possible to create a conclusive picture or more precisely, a molecular movie . Although we are still far from a complete molecular description of the alternating access mechanism, remarkable progress has been made from static snapshots towards membrane transport dynamics."
Mechanics plays a central role in determining form and function in biology. This holds at the cellular, molecular and tissue scales. At the cellular scale, mechanics in?uences cell adhesion, cytoskeletal dynamics and the traction that the cell can generate on a given substrate. All of these in turn - fect the cellular functions of migration, mitosis, phagocytosis, endocytosis and stem cell differentiation among others. Indeed, if cells do not develop the appropriate stresses, they are unviable and die. These aspects of cell mechanics are frequently used by mainstream biologists, as traditional mechanicians may be surprised to learn. There is a growing view that many functions of the cell are mechanical in nature even though chemical signals play crucial roles in the processes. Free energy barriers control transitions between different conformations of vir- ally every macromolecule including DNA, RNA, the adhesion protein integrin, the motor protein myosin, and the proteins vinculin and talin that link the cytoskeleton to focal adhesions. The strain energy can be a signi?cant component of the total free energy barrier. For binding to take place, the macromolecules need to be in conf- mational states that expose chemical groups without steric hinderance. The kinetics of chemical reactions are therefore strongly in?uenced by the conformational strain energy.
This volume describes the state-of-knowledge in the study of the relationships between mechanical loading states in tissues and common pathophysiologies related to increase in mass of adipose tissues and/or hyperglycemia which eventually lead to obesity, diabetes, insulin resistance, hyperlipidemia, metabolic inflammations, certain types of cancer and other related diseases. There appears to be an interaction between the loading states in tissues and cells and these chronic conditions, as well as with factors such as age, gender and genetics of the individual. Bioengineering has made key contributions to this research field in providing technologies for cell biomechanics experimentation, microscopy and image processing, tissue engineering and multi-scale, multi-physics computational modeling. Topics at the frontier of this field of study include: the continuous monitoring of cell growth, proliferation and differentiation in response to mechanical factors such as stiffness of the extracellular matrix (ECM) and mechanical loads transferred through the ECM; mechanically-activated signaling pathways and molecular mechanisms; effects of different loading regimes and mechanical environments on differentiation fates of mesenchymal stem cells (MSCs) into myogenic and osteogenic versus adipogenic lineages; the interactions between nutrition and mechanotransduction; cell morphology, focal adhesion patterns and cytoskeletal remodeling changes in adipogenesis; activation of receptors related to diabetes by mechanical forces; brown and white adipose plasticity and its regulation by mechanical factors.
This book is a collection of experimental studies demonstrating structure-function relationships in various biological systems having particular surface specialization to increase/decrease friction and adhesion. Studies on snake skin, adhesive pads, wing-interlocking devices and sticky mouthparts of insects as well as anti-adhesive and adhesive surfaces of plants are included in the volume containing four main subsections: (1) adhesion, (2) friction, (3) attachment-devices, (4) attachment-related behavior. Numerous experimental methods for characterizing tribological properties of biological surfaces at macro-, micro-, and nanoscale levels are demonstrated. This book is an excellent collection of publications on biotribology for both engineers and physicists working with biological systems as well as for biologists studying friction and adhesion. Inspirations from biology reported here may be also potentially interesting for biomimetics.
A reissue of a classic book, intended for undergraduate courses in biophysics, biological physics, physiology, medical physics, and biomedical engineering. This is an introduction to mechanics, with examples and problems from the medical and biological sciences, covering standard topics of kinematics, dynamics, statics, momentum, and feedback, control and stability but with the emphasis on physical and biological systems. The book can be used as a supplement to standard introductory physics courses, as well as for medical schools, medical physics courses, and biology departments. The three volumes combined present all the major topics in physics. Originally published in 1974 from the authors typescript, this reissue will be edited, corrected, typeset, the art redrawn, and an index added, plus a solutions manual will also be available.
This book focuses on important interfacial phenomena, such as interfacial potential and interfacial multi-functionality, responsible for determining the fate of nanoparticles inside the biological milieu. Additionally, this book explores the role of surface defects in photocatalytic nanoparticles in defining the nanoparticle interaction to biological membrane and cytotoxic propensity.The authors describe the interfacial assembly of peptide/protein on conformational/functional dynamics of the peptide/protein, which may be adopted as an approach to moderate the protein misfolding diseases.
The IUTAM Symposium on Flow in Collapsible Tubes and Past Other Highly Compliant Boundaries was held on 26-30 March, 2001, at the University of Warwick. As this was the first scientific meeting of its kind we considered it important to mark the occasion by producing a book. Accordingly, at the end of the Symposium the Scientific Committee met to discuss the most appropriate format for the book. We wished to avoid the format of the conventional conference book consisting of a large number of short articles of varying quality. It was agreed that instead we should produce a limited number of rigorously refereed and edited articles by selected participants who would aim to sum up the state of the art in their particular research area. The outcome is the present book. Peter W. Ca rpenter, Warwick Timothy J. Pedley, Cambridge May, 2002. VB SCIENTIFIC COMMITTEE Co-Chair: P.W. Carpenter, Engineering, Warwiek, UK Co-Chair: TJ. Pedley, DAMTP, Cambridge, UK V.V. Babenko, Hydromechanics, Kiev, Ukraine R. Bannasch, Bionik & Evolutionstechnik, TU Berlin, Germany C.D. Bertram, Biomedical Engineering, New South Wales, Australia M. Gad-el-Hak, Aerospace & Mechanical Engineering, Notre Dame, USA J.B. Grotberg, Biomedical Engineering, Michigan, USA. R.D. Kamm, Mechanical Engineering, MIT, USA Y. Matsuzaki, Aerospace Engineering, N agoya, Japan P.K. Sen, Applied Mechanics, IIT Delhi, India L. van Wijngaarden, Twente, Netherlands K-S. Yeo, Mechanical Engineering, NU Singapore.
A "brain defibrillator" may be closer than we think. An epileptic seizure involves a paroxysmal change in the activity of millions of neurons. Feedback control of seizures would require an implantable device that could predict seizure occurrence and then deliver a stimulus to abort it. To examine the feasibility of building such a device, this text brings together experts in epilepsy, bio-engineering, and dynamical systems theory. Topics include the development of epileptic systems, seizure prediction, neural synchronization, wave phenomena in excitable media, and the control of complex neural dynamics using brief electrical stimuli.
This volume focuses on latest research in therapeutic devices for cardiovascular, i.e. vascular and valvular and cardiac diseases. In the area of vascular therapies, aspects covered relate to latest research in small-diameter tissue-regenerative vascular grafts, one of the greatest persisting challenges in cardiovascular therapies, stent grafts and endovascular stents for percutaneous arterial interventions. Contributions on valvular therapies focus on tissue engineered and tissue regenerative prosthetic heart valves and valvular prostheses for trans-apical implantation including the challenges posed on the prosthesis design. The section on cardiac diseases aims at covering therapeutic advances for myocardial infarction and prevention of heart failure and on in vivo biomechanics of implantable cardiac pacemaker devices. A further section complements these three areas by presenting constitutive modelling of soft biological tissues of the cardiovascular system, an area imperative for advanced numerical and computational modelling in the development and optimisation of cardiovascular devices and therapies.
This volume details the essential role of the spiral ganglion neurons. The volume elucidates and characterizes their development, their environment, their electrophysiological characteristics, their connectivity to their targets in the inner ear and the brain, and discusses the potential for their regeneration. A comprehensive review about the spiral ganglion neurons is important for researchers not only in the inner ear field but also in development, neuroscience, biophysics as well as neural networks researchers. The chapters are authored by leading researchers in the field.
Non-Newtonian properties on bubble dynamics and cavitation are fundamentally different from those of Newtonian fluids. The most significant effect arises from the dramatic increase in viscosity of polymer solutions in an extensional flow, such as that generated about a spherical bubble during its growth or collapse phase. In addition, many biological fluids, such as blood, synovial fluid, and saliva, have non-Newtonian properties and can display significant viscoelastic behaviour. This monograph elucidates general aspects of bubble dynamics and cavitation in non-Newtonian fluids and applies them to the fields of biomedicine and bioengineering. In addition it presents many examples from the process industries. The field is strongly interdisciplinary and the numerous disciplines involve have and will continue to overlook and reinvent each others' work. This book helps researchers to think intuitively about the diverse physics of these systems, to attempt to bridge the various communities involved, and to convey the interest, elegance, and variety of physical phenomena that manifest themselves on the micrometer and microsecond scales.
This volume - like the NATO Advanced Research Workshop on which it is based - addresses the fundamental science that contributes to our understanding of the potential risks from ecological terrorism, i.e. dirty bombs, atomic explosions, intentional release of radionuclides into water or air. Both effects on human health (DNA and systemic effects) and on ecosystems are detailed, with particular focus on environmentally relevant low-dose ranges. The state-of-the-art contributions to the book are authored by leading experts; they tackle the relevant questions from the perspectives of radiation genetics, radiobiology, radioecology, radiation epidemiology and risk assessment.
Transport properties of plant cuticles are important for different ?elds of modern plant sciences. Ecologists and physiologists are interested in water losses to the environment via the cuticle. Penetration of plant protecting agents and nutrients into leaves and fruits is relevant for research in agriculture and plant protection. Ecotoxicologists need to know the amounts of environmental xenobiotics which accumulate in leaves and other primary plant organs from the environment. For all of these studies suitable methods should be used, and a sound theoretical basis helps to formulate testable hypotheses and to interpret experimental data. Unnecessary experiments and experiments which yield ambiguous results can be avoided. In this monograph, we have analysed on a molecular basis the movement of molecules across plant cuticles. Based on current knowledge of chemistry and str- ture of cuticles, we have characterised the aqueous and lipophilic pathways, the nature and mechanisms of mass transport and the factors controlling the rate of movement. We have focused on structure-property relationships for penetrant tra- port, which can explain why water and solute permeabilities of cuticles differ widely among plant species. Based on this knowledge, mechanisms of adaptation to en- ronmental factors can be better understood, and rates of cuticular penetration can be optimised by plant physiologists and pesticide chemists.
Adhesion plays a major role in the bacterial lifestyle. Bacteria can adhere to organic and inorganic surfaces, to each other, and of course to host cells during pathogenesis. The focus of this book is: how are such adhesion phenomena best studied? Microbial genetics experiments have greatly enhanced our knowledge of what bacterial factors are involved in adhesion. For numerous reasons, though, biochemical and structural biology knowledge of the molecular interactions involved in adhesion are limited. One major problem has been a lack of interdisciplinary research and understanding in the field. On the one hand, the microbiologists lack detailed knowledge of the biophysical possibilities and have limited access to the frequently expensive instrumentation involved while on the other hand, the experts in these methods frequently do not have access to the biological materials, nor do they necessarily understand the biological questions to be answered. The purpose of this book is thus to overcome this gap in communication between researchers in biology, chemistry and physics and to display the many ways and means to investigate bacterial adhesion. We hope to stimulate new and ground-breaking research.
Optical microscopy and associated technologies advanced quickly after the introduction of the laser. The techniques have stimulated further development of optical imaging theory, including 3-dimensional microscopy imaging theory in spatial and frequency domains, the theory of imaging with ultrashort-pulse beams and aberration theory for high-numerical-aperture objectives. This book introduces these new theories in terms of modern optical microscopy. It consists of seven chapters including an introduction. The chapters are organized to minimize cross-referencing. Comparisons with classical imaging theory are made when the new imaging theory is introduced. The book is intended for senior undergraduate students in courses on optoelectronics, optical engineering, photonics, biophotonics and applied physics, after they have completed modern optics or a similar subject. It is also a reference for other scientists interested in the field.
This book focuses on the assembly, organization and resultant collective dynamics of soft matter systems maintained away from equilibrium by an energy flux. Living matter is the ultimate example of such systems, which are comprised of different constituents on very different scales (ions, nucleic acids, proteins, cells). The result of their diverse interactions, maintained using the energy from physiological processes, is a fantastically well-organized and dynamic whole. This work describes results from minimal, biomimetic systems and primarily investigates membranes and active emulsions, as well as key aspects of both soft matter and non-equilibrium phenomena. It is shown that these minimal reconstitutions are already capable of a range of complex behaviour such as nonlinear electric responses, chemical communication and locomotion. These studies will bring us closer to a fundamental understanding of complex systems by reconstituting key aspects of their form and function in simple model systems. Further, they may also serve as the first technological steps towards artificial soft functional matter.
Heme and chlorophyll (Chl) are porphyrins. Porphyrins (also referred to as tetrapyrroles) are essential for life in the biosphere. Chlorophyll catalyzes the conversion of solar energy to chemical energy via the process of photosynthesis. Organic life in the biosphere is made possible by consumption of the chemical energy generated by photosynthesis. Hemes are the prosthetic groups of cytochromes which are involved in electron transport during oxidative phosphorylation and photosynthetic phosphorylation which generate ATP and NADPH. The latter are essential for many cellular functions. Chlorophyll on the other hands catalyzes the process of photosynthesis. Indeed, life in the biosphere depends on the process of photosynthesis which converts light energy, carbon dioxide and water into the chemical energy, required for the formation of food and fiber. Photosynthetic efficiency is controlled by extrinsic factors such as the availability of water, CO2, inorganic nutrients, ambient temperature and the metabolic and developmental state of the plant, as well as by intrinsic factors (Lien and San Pietro, 1975). The most important intrinsic factor is the efficiency of the photosynthetic electron transport system (PETS). Conventional agriculture is one of the few human activities that have not undergone a revolution to join other activities such as overcoming gravity by flying, and landing on the moon, crossing underwater the polar cap, and communicating wirelessly over long distances via electromagnetic waves. We now feel that enough biochemical and molecular biological knowledge has accumulated to render this dream amenable to experimentation. We believe that the time has come to bioengineer chloroplasts capable of synthesizing a short chain carbohydrate such as glycerol at rates that approach the upper theoretical limits of photosynthesis [Rebeiz, C. A. (2010) Investigations of possible relationships between the chlorophyll biosynthetic pathway and the assembly of chlorophyll-protein complexes and photosynthetic efficiency. In: Rebeiz, C. A. Benning, C., Bohnert, H.J., Daniell, H., Hoober J. K., Lichtenthaler, H. K., Portis , A. R., and Tripathy, B. C. eds. The chloroplast: Basics and Applications. Springer. The Netherlands, p 1-24]. In order to achieve this goal a thorough knowledge of the Chl biosynthetic pathway is needed along with knowledge in other domains (Rebeiz 2010). In this context, this monograph is devoted to an in depth discussion of our present knowledge of the Chl biosynthetic pathway. The complexity and biochemical heterogeneity of the Chl biosynthetic pathway and the relationship of this complexity to the structural and biosynthetic complexity of photosynthetic membranes will be emphasized. We will also emphasize in historical perspective, key stages in our understanding of the Chl biosynthetic heterogeneity. The reader should keep in mind that a complex biosynthetic process is only fully understood when it becomes possible to reconstitute in vitro every step of the process. We are not yet at this stage of understanding of thylakoid membrane biogenesis. Considerable progress has been achieved however, in the understanding of numerous facets of the Chl biosynthetic pathway, namely (a) detection and identification of various major and minor metabolic intermediates (b) precursor-product relationships between various intermediates, (c) structure and regulation of many enzymes of the pathway, and (d) the relationship of the Chl biosynthetic heterogeneity to the structural and functional heterogeneity of thylakoid membranes. In addition topics related to the development of Analytical techniques, Cell-free systems, Herbicides, Insecticides, and Cancericides are also discussed.
This book highlights recent advances in and diverse techniques for exploring the plasma membrane's structure and function. It starts with two chapters reviewing the history of membrane research and listing recent advances regarding membrane structure, such as the semi-mosaic model for red blood cell membranes and the protein layer-lipid-protein island model for nucleated tissue cell membranes. It subsequently focuses on the localization and interactions of membrane components, dynamic processes of membrane transport and transmembrane signal transduction. Classic and cutting-edge techniques (e.g. high-resolution atomic force microscopy and super-resolution fluorescence microscopy) used in biophysics and chemistry are presented in a very comprehensive manner, making them useful and accessible to both researchers in the field and novices studying cell membranes. This book provides readers a deeper understanding of the plasma membrane's organization at the single molecule level and opens a new way to reveal the relationship between the membrane's structure and functions, making it essential reading for researchers in various fields.
The biophysics of excitable membranes and extracellular potential fields emerged at the end of the 18th century, together with electrophysiology, and has been used ever since as a basis for the development of electrophysiological investigations. This holds true even for the contemporary stage of initial discoveries concerning the molecular mechanisms of membrane excitability. The biophysics of ionic channels has gradually revealed the genesis of the ionic currents and of the biopotentials in different excitable structures. On the basis of electrodynamics, the extracellular potential fields in the living body, considered as a volume conductor, have been studied intensively. The knowledge accumulated constitutes the theoretical basis for interpretation of the electrophysiological data. Over a period of more than 15 years a group of Bulgarian investigators led by A. Gydikov has systematically studied the dependence between the intra- and extracellular potentials of the skeletal muscles. The present book summarizes these investigations. Using a great amount of factual material from experiments and model investigations on the skeletal muscle potentials, the author considers: (a) the extracellular potential field of single skeletal muscle fibres and their dependence of the parameters of intracellular action potentials, the geometric parameters of the fibres and of the volume conductor; (b) the potentials of single motor units; (c) the compound and reflex muscle potentials, and (d) the interference electromyogram. The comprehensive consideration of the biophysics of skeletal muscle potentials is of interest to a broad circle of specialists. The book summarizes contemporary knowledge in thisfield and presents a consistent theoretical basis of electromyography which is of great importance not only for the neurological clinic, but also for different fields of applied physiology.
This book presents a physicists view of life. The primary life functions of animals, such as eating, growing, reproducing and getting around all depend on motion: Motion of materials through the body, motion of limbs and motion of the entire body through water, air and on land. These activities are driven by internal information stored in the genes or in the brain and by external information transmitted by the senses. This book models these life functions with the tools of physics. It will appeal to all scientists, from the undergraduate level upwards, who are interested in the role played by physics in the animal kingdom.
The present book provides recent developments in various in vivo imaging and sensing techniques such as photo acoustics (PA) imaging and microscopy, ultrasound-PA combined modalities, optical coherence tomography (OCT) and micro OCT, Raman and surface enhanced Raman scattering (SERS), Fluorescence lifetime imaging (FLI) techniques and nanoparticle enabled endoscopy etc. There is also a contributing chapter from leading medical instrumentation company on their view of optical imaging techniques in clinical laparoscopic surgery. The UN proclaimed 2015 as the International Year of Light and Light-based Technologies, emphasizing achievements in the optical sciences and their importance to human beings. In this context, this book focusses on the recent advances in biophotonics techniques primarily focused towards translational medicine contributed by thought leaders who have made cutting edge developments in various photonics techniques.
The living organisms and systems possess extraordinary properties of programmed development, differentiation, growth, response, movement, duplication of key molecules and in m any cases higher mental functions. But the organisms are physical objects so they must follow laws of physics yet they do not seem to obey them. Physicists cannot easily persuade themselves to accept this as finally true. Non-living objects are governed by these laws of physics and they can explain these properties. However, in the living systems too phenomena encountered like coupled non-linear interactions, manybody effects, cooperativity, coherence, phase transitions, reversible metastable states are being understood better with the aid of powerful theoretical and experimental techniques and hope is raised that these may let us understand the mysteriousness of life. Contributors to this volume are a small fraction of rapidly growing scientific opinion that these aspects of living bodies are to be expected in a hitherto inadequately suspected state of matter which is in the main directed by these physical properties pushed almost to limit. This state of matter, the living matter, deserves to be called The Living State. Mishra proposes that given hydrogenic orbitals, atoms showing easy hybridisability and multiple valances, molecules with low-lying electronic levels, "loosestructure," and a metabolic pump in thermodynamically open system, various fundamental properties of living state can emerge automatically. Structurally these are all known to be present. |
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