In the past few decades, Magnetic Resonance Imaging (MRI) has become an indispensable tool in modern medicine, with MRI systems now available at every major hospital in the developed world. But for all its utility and prevalence, it is much less commonly understood and less readily explained than other common medical imaging techniques. Unlike optical, ultrasonic, X-ray (including CT), and nuclear medicine-based imaging, MRI does not rely primarily on simple transmission and/or reflection of energy, and the highest achievable resolution in MRI is orders of magnitude smaller that the smallest wavelength involved.
In this book, MRI will be explained with emphasis on the magnetic fields required, their generation, their concomitant electric fields, the various interactions of all these fields with the subject being imaged, and the implications of these interactions to image quality and patient safety. Classical electromagnetics will be used to describe aspects from the fundamental phenomenon of nuclear precession through signal detection and MRI safety. Simple explanations and Illustrations combined with pertinent equations are designed to help the reader rapidly gain a fundamental understanding and an appreciation of this technology as it is used today, as well as ongoing advances that will increase its value in the future. Numerous references are included to facilitate further study with an emphasis on areas most directly related to electromagnetics.
This is an overview of different models and mechanisms developed to describe the capture and relaxation of carriers in quantum-dot systems. Despite their undisputed importance, the mechanisms leading to population and energy exchanges between a quantum dot and its environment are not yet fully understood. The authors develop a first-order approach to such effects, using elementary quantum mechanics and an introduction to the physics of semiconductors. The book results from a series of lectures given by the authors at the Master’s level.
The concept of smart drug delivery vehicles involves designing and preparing a nanostructure (or microstructure) that can be loaded with a cargo. This can be a therapeutic drug, a contrast agent for imaging, or a nucleic acid for gene therapy. The nanocarrier serves to protect the cargo from degradation by enzymes in the body, to enhance the solubility of insoluble drugs, to extend the circulation half-life, and to enhance its penetration and accumulation at the target site. Importantly, smart nanocarriers can be designed to be responsive to a specific stimulus, so that the cargo is only released or activated when desired. In this volume we cover smart nanocarriers that respond to internal stimuli that are intrinsic to the target site. These stimuli are specific to the cell type, tissue or organ type, or to the disease state (cancer, infection, inflammation etc). pH-responsive nanostructures can be used for cargo release in acidic endosomal compartments, in the lower pH of tumors, and for specific oral delivery either to the stomach or intestine. Nanocarriers can be designed to be substrates of a wide-range of enzymes that are over-expressed at disease sites. Oxidation and reduction reactions can be taken advantage of in smart nanocarriers by judicious molecular design. Likewise, nanocarriers can be designed to respond to a range of specific biomolecules that may occur at the target site. In this volume we also cover dual and multi-responsive systems that combine stimuli that could be either internal or external.
The concept of smart drug delivery vehicles involves designing and preparing a nanostructure (or microstructure) that can be loaded with a cargo, this can be a therapeutic drug, a contrast agent for imaging, or a nucleic acid for gene therapy. The nanocarrier serves to protect the cargo from degradation by enzymes in the body, to enhance the solubility of insoluble drugs, to extend the circulation half-life, and to enhance its penetration and accumulation at the target site. Importantly, smart nanocarriers can be designed to be responsive to a specific stimulus, so that the cargo is only released or activated when desired. In this volume we cover smart nanocarriers that respond to externally applied stimuli that usually involve application of physical energy. This physical energy can be applied from outside the body and can either cause cargo release, or can activate the nanostructure to be cytotoxic, or both. The stimuli covered include light of various wavelengths (ultraviolet, visible or infrared), temperature (increased or decreased), magnetic fields (used to externally manipulate nanostructures and to activate them), ultrasound, and electrical and mechanical forces. Finally we discuss the issue of nanotoxicology and the future scope of the field.
This book introduces various 3D printing systems, biomaterials, and cells for organ printing. In view of the latest applications of several 3D printing systems, their advantages and disadvantages are also discussed. A basic understanding of the entire spectrum of organ printing provides pragmatic insight into the mechanisms, methods, and applications of this discipline.
Organ printing is being applied in the tissue engineering field with the purpose of developing tissue/organ constructs for the regeneration of both hard (bone, cartilage, osteochondral) and soft tissues (heart). There are other potential application areas including tissue/organ models, disease/cancer models, and models for physiology and pathology, where in vitro 3D multicellular structures developed by organ printing are valuable.
In the last few years, several “bottom-up” and “top-down” synthesis routes have been developed to produce tailored hybrid nanoparticles (HNPs). This book provides a new insight into one of the most promising “bottom-up” techniques, based on a practical magnetron-sputtering inert-gas-condensation method. A modified magnetron-sputtering-based inert-gas-condensation (MS-IGC) system is presented, and its performances under different conditions are evaluated.
Designed for graduate students, researchers in physics, materials science, biophysics and related fields, and process engineers, this new resource fills a critical need to understand the fundamentals behind the design and tailoring of the nanoparticles produced by the MS-IGC method. It shows that the morphology, the size and the properties of the nanoparticles can be modulated by tuning the deposition parameters such as the energy, the cooling rate, and the collision and coalescence processes experienced by the nanoparticles during their formation. The mechanisms of formation of different HNPs are suggested, combining the physico-chemical properties of the materials with the experimental conditions.
This book illustrates the potential of MS-IGC method to synthesize multifunctional nanoparticles and nanocomposites with accurate control on their morphology and structure. However, for a better understanding of HNPs formation, further improvements in characterization methods of aggregation zone conditions are needed. In addition, the optimization of the yield and harvesting process of HNPs is essential to make this method sufficiently attractive for large-scale production.
The ability to arrange precisely designed patterns of nanoparticles into a desired spatial configuration is the key to creating novel nanoscale devices that take advantage of the unique properties of nanomaterials. While two-dimensional arrays of nanoparticles have been demonstrated successfully by various techniques, a controlled way of building ordered arrays of three-dimensional (3D) nanoparticle structures remains challenging. This book describes a new technique called the 'nanoscopic lens' which is able to produce a variety of 3D nano-structures in a controlled manner. This ebook describes the nanoscopic lens technique and how it can serve as the foundation for device development that is not limited to a variety of optical, magnetic and electronic devices, but can also create a wide range of bio-nanoelectronic devices.
This is the first book written on using Blender (an open-source visualization suite widely used in the entertainment and gaming industries) for scientific visualization. It is a practical and interesting introduction to Blender for understanding key parts
Activity theory – a conceptual framework originally developed by Aleksei Leontiev – has its roots in the socio-cultural tradition in Russian psychology. The foundational concept of the theory is human activity, which is understood as purposeful, mediated, and transformative interaction between human beings and the world. Since the early 1990s, activity theory has been a visible landmark in the theoretical landscape of Human-Computer Interaction (HCI). Along with some other frameworks, such as distributed cognition and phenomenology, it established itself as a leading post-cognitivist approach in HCI and interaction design. In this book we discuss the conceptual foundations of activity theory and its contribution to HCI research.
After making the case for theory in HCI and briefly discussing the contribution of activity theory to the field (Chapter One) we introduce the historical roots, main ideas, and principles of activity theory (Chapter Two). After that we present in-depth analyses of three issues which we consider of special importance to current developments in HCI and interaction design, namely: agency (Chapter Three), experience (Chapter Four), and activity-centric computing (Chapter Five). We conclude the book with reflections on challenges and prospects for further development of activity theory in HCI (Chapter Six).
Table of Contents: Introduction: Activity theory and the changing face of HCI / Basic concepts and principles of activity theory / Agency / Activity and experience / Activity-centric computing / Activity theory and the development of HCI