Comprehensive theoretical and experimental analysis of UV-radiation and low energy electron induced phenomena in nucleic acid bases (NABs) and base assemblies are presented in this book. NABs are highly photostable; the absorbed energy is dissipated in the form of ultrafast nonradiative decay. This book highlights the possible mechanisms of these phenomena which is important for all living species and discusses technical challenges in exploration of these processes.

Since the discovery of X-rays and radioactivity, ionizing radiations have been widely applied in medicine both for diagnostic and therapeutic purposes. The risks associated with radiation exposure and handling led to the parallel development of the field of radiation protection. Pioneering experiments done by Sanche and co-workers in 2000 showed that low-energy secondary electrons, which are abundantly generated along radiation tracks, are primarily responsible for radiation damage through successive interactions with the molecular constituents of the medium. Apart from ionizing processes, which are usually related to radiation damage, below the ionization level low-energy electrons can induce molecular fragmentation via dissociative processes such as internal excitation and electron attachment. This prompted collaborative projects between different research groups from European countries together with other specialists from Canada, the USA and Australia. This book summarizes the advances achieved by these research groups after more than ten years of studies on radiation damage in biomolecular systems. An extensive Part I deals with recent experimental and theoretical findings on radiation induced damage at the molecular level. It includes many contributions on electron and positron collisions with biologically relevant molecules. X-ray and ion interactions are also covered. Part II addresses different approaches to radiation damage modelling. In Part III biomedical aspects of radiation effects are treated on different scales. After the physics-oriented focus of the previous parts, there is a gradual transition to biology and medicine with the increasing size of the object studied. Finally, Part IV is dedicated to current trends and novel techniques in radiation reserach and the applications hence arising. It includes new developments in radiotherapy and related cancer therapies, as well as technical optimizations of accelerators and totally new equipment designs, giving a glimpse of the near future of radiation-based medical treatments.

The growth of technology for chemical assessment has led to great developments in the investigation of chemical reactivity in recent years, but key information is often dispersed across many different research fields. Exploring both traditional and advanced methods, Chemical Reactivity, Volume 2: Approaches and Applications present the latest approaches and strategies for the computational assessment of chemical reactivity.Following an insightful introduction, the book begins with an overview of conformer searching techniques before progressing to explore numerous different techniques and methods, including confined environments, quantum similarity descriptors, volume-based thermodynamics and polarizability. A unified approach to the rules of aromaticity is followed by methods for assessing interaction energies and the role of electron density for varied different analyses. Algorithms for confirmer searching, partitioning and a whole range of quantum chemical methods are also discussed.Consolidating the knowledge of a global team of experts in the field, Chemical Reactivity, Volume 2: Approaches and Applications is a useful resource for both students and researchers interested in applying and refining their use of the latest approaches for assessing chemical reactivity in their own work. - Compiles a broad range of contemporary methods and approaches for reactivity and structure prediction - Highlights the application of chemical reactivity strategies for the investigation of such areas as aromaticity, halogen bonds, and electronic materials - Includes discussion of computational tools for exploring molecular spaces from different angles, including interaction energies, quantum similarity, and electron density

The DNA of all organisms is constantly being damaged by endogenous and exogenous sources. Oxygen metabolism generates reactive species that can damage DNA, proteins and other organic compounds in living cells. Exogenous sources include ionizing and ultraviolet radiations, carcinogenic compounds and environmental toxins among others. The discovery of multiple DNA lesions and DNA repair mechanisms showed the involvement of DNA damage and DNA repair in the pathogenesis of many human diseases, most notably cancer. These books provide a comprehensive overview of the interdisciplinary area of DNA damage and DNA repair, and their relevance to disease pathology. Edited by recognised leaders in the field, this two-volume set is an appealing resource to a variety of readers including chemists, chemical biologists, geneticists, cancer researchers and drug discovery scientists.

This book discusses biomedical spectroscopy and the applications of spectroscopic techniques in advanced medical technology. Applicable to scientists and medical professionals, the aim of this work is to enable them to work together in this field, so that healthcare facilities can be made routinely available in a cost-effective manner—especially for developing countries which may not be able to afford universal healthcare with present day expensive medical technologies. The subject matter of this book also covers – Instrumentation, Experimental Techniques and Computational Methods Spectroscopy of Animal Models Microspectroscopy for Biomedical Applications Clinical Applications of Optical Spectroscopy Spectroscopy of Human Models Print edition not for sale in South Asia (India, Sri Lanka, Nepal, Bangladesh, Pakistan and Bhutan)

Practical Aspects of Computational Chemistry I: An Overview of the Last Two Decades and Current Trends gathers the advances made within the last 20 years by well-known experts in the area of theoretical and computational chemistry and physics. The title itself reflects the celebration of the twentieth anniversary of the “Conference on Current Trends in Computational Chemistry (CCTCC)” to which all authors have participated and contributed to its success. This volume poses (and answers) important questions of interest to the computational chemistry community and beyond. What is the historical background of the “Structural Chemistry”? Is there any way to avoid the problem of intruder state in the multi-reference formulation? What is the recent progress on multi-reference coupled cluster theory? Starting with a historical account of structural chemistry, the book focuses on the recent advances made in promising theories such as many body Brillouin-Wigner theory, multireference state-specific coupled cluster theory, relativistic effect in chemistry, linear and nonlinear optical properties of molecules, solution to Kohn-Sham problem, electronic structure of solid state materials, development of model core potential, quantum Monte Carlo method, nano and molecular electronics, dynamics of photodimerization and excited states, intermolecular interactions, hydrogen bonding and non-hydrogen bonding interactions, conformational flexibility, metal cations in zeolite catalyst and interaction of nucleic acid bases with minerals. Practical Aspects of Computational Chemistry I: An Overview of the Last Two Decades and Current Trends is aimed at theoretical and computational chemists, physical chemists, materials scientists, and particularly those who are eager to apply computational chemistry methods to problem of chemical and physical importance. This book will provide valuable information to undergraduate, graduate, and PhD students as well as to established researchers.

This book gives an extensive description of the state-of-the-art in research on excited-state hydrogen bonding and hydrogen transfer in recent years. Initial chapters present both the experimental and theoretical investigations on the excited-state hydrogen bonding structures and dynamics of many organic and biological chromophores. Following this, several chapters describe the influences of the excited-state hydrogen bonding on various photophysical processes and photochemical reactions, for example: hydrogen bonding effects on fluorescence emission behaviors and photoisomerization; the role of hydrogen bonding in photosynthetic water splitting; photoinduced electron transfer and solvation dynamics in room temperature ionic liquids; and hydrogen bonding barrier crossing dynamics at bio-mimicking surfaces. Finally, the book examines experimental and theoretical studies on the nature and control of excited-state hydrogen transfer in various systems. Hydrogen Bonding and Transfer in the Excited State is an essential overview of this increasingly important field of study, surveying the entire field over 2 volumes, 40 chapters and 1200 pages. It will find a place on the bookshelves of researchers in photochemistry, photobiology, photophysics, physical chemistry and chemical physics.