Radio frequency ablation (RFA) has become the most commonly used ablative therapy for selected group of patients with liver tumors. To understand the effectiveness of RFA it is important to understand the mechanism of injury to the liver caused by RFA. There is no large animal model to study hepatocellular cancer. This book details the animal experiments carried out by the author in an attempt to create a porcine model of hepatocellular cancer. This book also details the discovery of Transition zone following ablation of liver tissue. This zone lies beyond the zone of cell necrosis and can not be identified by the usual histological techniques. Transition zone lies between necrotic liver tissue and normal liver parenchyma in lesion produced by RFA. This zone has cells showing apoptosis and increased expression of Heat Shock Protein (HSP) suggestive of cellular injury which will eventually lead to cell death. Further research to find techniques to increase the size of "Transition zone" may help in ablating larger areas of liver tumors.
This book is mostly concerned on the experimental research of the nonlinear optical characteristics of various media, low- and high-order harmonic generation in different materials, and formation, and nonlinear optical characterization of clusters. We also demonstrate the inter-connection between these areas of nonlinear optics.Nonlinear optical properties of media such as optical limiting can be applied in various areas of science and technology. To define suitable materials for these applications, one has to carefully analyse the nonlinear optical characteristics of various media, such as the nonlinear refractive indices, coefficients of nonlinear absorption, saturation absorption intensities, etc. Knowing the nonlinear optical parameters of materials is also important for describing the propagation effects, self-interaction of intense laser pulses, and optimisation of various nonlinear optical processes. Among those processes one can admit the importance of the studies of the frequency conversion of coherent laser sources. The area of interest for nonlinear optical characterization of materials is also closely related with new field of nanostructures formation and application during laser-matter interaction.We show how the nonlinear optical analysis of materials leads to improvement of their high-order nonlinear optical response during the interaction with strong laser fields. Ablation-induced nanoparticles formation is correlated with their applications as efficient sources of coherent short-wavelength photons. From other side, recent achievements of harmonic generation in plasmas are closely related with the knowledge of the properties of materials in the laser plumes. All of these studies are concerned with the low-order nonlinear optical features of various materials. The novelty of the approach developed in present book is related with inter-connection of those studies with each other.
Reconstruction of large and complex bone segments is one of the most challenging problems facing modern clinical practice. In order to diminish the donor site morbidity associated with autogenous bone transfer, synthetic biomaterials are being used nowadays to regenerate lost bone due to disease or trauma. The majority of currently applied regenerative medicine approaches rely on extrinsic vascularization, which could not be applied to reconstruction after cancer ablation. This book presents an experimental pilot study introducing for the first time the concept of axial vascularization of bone substitutes to regenerate mandibular defects in a large animal model (goat). The book is also presenting a review about conventional reconstructive techniques, describes the fine details of a novel model for axial vascularization and discusses its results in comparison with literature. The book contains valuable details suitable for graduate, and post-graduate researchers in the field of Reconstructive Maxillofacial surgery as well as biotechnology and Regenerative medicine.
This book reveals some details of research done at Marshall University, USA, involving functional aspects of pancreatic beta cells in several experimental models: avian, transgenic mice, and beta-cell lines. In this book you will gain some knowledge of genetic engineering approaches to improve beta-cell insulin secretion which could be applied to manage models and cases of diabetes mellitus. This work is presented as three separate chapters. The first chapter aims to gain an understanding of the expression pattern of CaBP28k in the chicken pancreas and to explore its spatial relationships with insulin in beta cells. The second chapter is to identify the influence of CaBP28k-ablation on the dynamics of [Ca2+]i in response to glucose stimulation in murine beta cells of CaBP28k-KO mice pancreatic islets and wildtype islets. The third chapter is an attempt to elucidate the genomic and non-genomic effects of in vitro CaBP28k-ablation in a cultured beta-cell line. It highlights the effects on the gene expression profile and insulin secretory responses from cultured rat insulinoma cell lines using antisense oligonucleotides transfection.
The radiative properties of plasmas are governed by opacity and emissivity. Accurate determinations of these quantities are of relevance, therefore, to inertially confined nuclear fusion (particularly indirect drive schemes) and to resolving discrepancies between the observed behavior of astrophysical plasmas and theory. This work summarises achievements in the field over the last few decades. It also presents the results of experiments to (i) determine the opacity of warm to hot, dense iron plasma and (ii) investigate laser ablation rates using the transmission through sample targets of x-ray laser pulses. These results are compared with the predictions of computer simulations. Laser ablation rates are of relevance to direct drive nuclear fusion and other technologies such as laser welding and materials deposition. Experimental work was undertaken using a nickel-like silver x-ray laser (XRL) of 13.9 nm wavelength at the Rutherford Appleton Laboratory and a 21.2 nm neon-like zinc XRL at the Prague Asterix Laser System.
As Neurosurgeon I was interested to know more about epilepsy for two main reasons. First, the surgeon encounters and manages pathological conditions, which may induce seizures, these conditions are referred to as symptomatic epilepsies. Second, nearly one third of genuine epilepsies remain resistant to pharmacotherapy and neurosurgical intervention may be needed for better seizure control. That motivated me to join the research group of the Institute of the Anatomy of University of Szeged to follow experimemtal studies on 4-aminopyridin induced epileptic seizures. We aimed to follow the path and traces of epileptogenesis in every possible way: basic histological, electrophysiological, behavioural studies were accomplished with mapping of potential receptors playing central role in the process.
After decades of development, laser ablation has become an important technique for a large number of applications such as thin film deposition, nanoparticle synthesis, micromachining, chemical analysis, etc. Experimental and theoretical studies have been conducted to understand the physical mechanisms of the laser ablation processes and their dependence on the laser wavelength, pulse duration, ambient gas and target material. The present work describes and investigates the relative importance of the physical mechanisms influencing the characteristics of aluminum laser-induced plasmas. The general scope of this research encompasses a thorough study of the interplay between the plasma plume dynamics and the ambient gas in which they expand. This is achieved by imaging and analyzing the temporal and spatial evolution the plume in terms of spectral intensity, electron density and excitation temperature within various environments, extending from vacuum to atmospheric pressure (760 Torr), in an inert gas like argon and heluim, as well as in a chemically active gas like nitrogen.
Laser-induced shock waves have found many applications such as artifacts cleaning, material processing, lithotripsy, photo-disruption and nano-surgery. In artifact cleaning, contamination from the surface are removed without damaging the surface. Reasonably higher laser pulse energies help the obtainment of better surface clearness. In laser ablative lithotripsy, the stone is fragmentized, and stone ablation in water showed better results than in air. Chapter 1 reviews the previous experimental work and outlines some theoretical background. Chapter 2 describes the experimental techniques and Chapter 3 illustrates all results obtained and discusses their impact on laser surface cleaning of surfaces and stone fragmentation. Chapter 4 concludes the main findings and suggests some future work. This book is a valuable source of information to medical doctors, archaeologists, academics and students in the field of science and engineering. It is written in a narrative way with a large number of photos, tables and plots. It needs no deep scientific background to understand.
The gold nanoparticles prepared by laser ablation (Q-switched Nd:YAG) at different experimental parameters. The results show that, as the ethanol ratio increases, the average size of prepared GNPs was increased and their size distribution became broad. The second parameter studied was the ablation time. As ablation time increased, the concentration of the obtained GNPs was increased. If the fluence of laser beam increased, the average size of particles became smaller until, it reaches to critical size at certain fluence and then became increase again as the fluence increased. It was found that the 1064nm wave length was more effective than 532nm wavelength. When the geometry of laser beam changed the shapes and the average size of GNPs were changed.