The Effect of Laser Induced Thermal Ablation on Liver Tumours ab 78.99 € als Taschenbuch: . Aus dem Bereich: Bücher, Wissenschaft, Medizin,
The Effect of Laser Induced Thermal Ablation on Liver Tumours ab 78.99 EURO
This dissertation presents a novel technique ofdelivering membrane impermeable molecules into singleliving cells with the assistance of femtosecond (fs)near-infrared (NIR) laser pulses. This techniquepromises several major advantages, namely, very hightransfection efficiency, high cell survival rate( 100%) and fully preserved cell viabilities. In this work, the system for fs NIR opto-injectionwas designed and built. Successful fs NIRopto-injection has been performed on several cellsystems including single mammalian cells, marineanimal eggs, and human cancer cells cultured in atissue-like environment. The connections betweenlaser parameters and cell responses were explored.Dye uptake rate of the target cells was observed todepend on incident laser intensity. Pore size wasfound dependent on incident laser intensity. Theconclusion was made that laser-induced breakdown andplasma-induced ablation in cell membrane are thephysical principles that govern the process of fs NIRopto-injection.
Laser thermal ablation (LTA) is an in situ ablative techniquethat induces heat destruction of liver tumours. Despite increasingclinical use of LTA, reports of long-term outcomes and limitationsof treatment in specific cohorts of patients with liver tumours arelacking. In addition, the mechanisms of action of therapy are notfully understood. This book highlights some of the clinical resultsand limitations of LTA in the treatment of colorectal livermetastases and examines its mechanisms of action. Overall, there isa high incidence of local tumour recurrence following thermalablation due to incomplete tumour destruction and regional andextrahepatic tumour recurrences. The mechanisms of action ofthermal ablation appear to be multifactorial with interplay ofseveral factors. An understanding and manipulation of the processesmay further ensure complete tumour destruction and reduce local anddistal recurrences. This may encourage more widespread use of thistechnology for the treatment of liver tumours. This book should beespecially useful for health professionals and researchers with aninterest in the ever expanding field of thermal ablation of livertumours.
The increasing demand for high-protein food from aquatic sources and the necessity to find an alternative for fisheries have given rise to a world-wide expansion of crustacean aquaculture. The bottleneck in crustacean aquaculture industry is the limited availability of quality seed. Eyestalk ablation technique is now practiced in the shrimp farms world-wide to induce spawning. The limitation with eyestalk-ablation-induced reproduction is the poor quality of the seed produced and high mortality in the brood stock. To overcome the above problems, one important task for the aquaculture biotechnologists will be finding the alternatives for eyestalk ablation that can accomplish the same increase in productivity. For a long time, biogenic amines have been considered as neurotransmitters and regulate a variety of functions including reproduction in crustaceans. This study aims at elucidating the effect of dopamine, serotonin and melatonin on ovarian maturation and growth in the fresh water edible crab, Oziotelphusa senex senex. This book provides valuable information to those working for hatchery industry and scientists working in the area of aquaculture and also to the interested layman.
In this work multi-application, multi-walled carbon nanotubes (MWCNTs) as super MR contrast agents and Near-Infared Radiation (NIR) laser absorbers are combined with Proton Resonance Frequency (PRF) based Magnetic Resonance Temperature Imaging (MRTI) to improve the safety and efficacy of Laser Induced Thermal Therapy (LITT). Instilled MWCNTs enable precise tumor localization and killing of the tumor through preferential high temperature while protecting surrounding healthy tissue by monitoring the 3D temperature distribution. As advanced MR contrast agents (CA), Fe-containing MWCNTs produced by chemical vapor deposition (CVD) with 600mg Ferrocene, show up to 5 times greater efficiency in changing T2 relaxation properties compared to the clinical MR CA, Feridex. Thus, MWCNTs could be used potentially as a super heating generator and contrast agents in thermal ablation therapy.
A novel femtosecond micromachining workstation that permits real-time measurement of ablation depth and transient reflectivity is demonstrated. This instrumentation is used to characterize two processes: micromachining of thin metal films, and laser induced forward transfer (LIFT). Spectral interferometry was incorporated in a femtosecond micromachining system to enable real-time visualization of micromachined features as they are written into thin metal films-low energy(pJ) femtosecond oscillator pulses are used to probe the sample as it is cut by high energy (uJ) pulses. Sub-wavelength depths are readily resolved using this technique, making it possible to monitor the integrity of micromachined structures as they are created. This technique can also be employed to characterize interesting processes such as laser induced forward transfer (LIFT) of thin metal films. LIFT essentially involves using a pulsed laser to pattern a structure by deposition as opposed to ablation. Using modest numerical apertures (0.65 or less) we have been able to produce submicron features using this method of femtosecond pulsed laser deposition.
Ultrafast lasers have been widely employed for material micro/nano processing with little thermal damage. Due to the ultra high intensity of ultrashort pulses, nonlinear absorption can be induced at the focus leading to highly localised material ablation or modification. This is now opening up applications ranging from integrated optics, through multi-photon induced refractive index engineering to precision surface micro-structuring. To ensure the non-thermal processing, input pulse energy must be kept around micro-joule level. However, running at kilohertz repetition rate, many ultrafast laser systems can provide milli-joule level output. Therefore, significant energy attenuation causes a great deal of energy loss. With this limitation in mind, a multi-beam ultrafast laser processing, where the milli-joule output is split into many desired diffracted beams, is proposed in this book. The multi-beam patterns are generated by phase modulation through a Spatial Light Modulator (SLM) and can be applied in real time with synchronized scanning methods. The results demonstrate high precision parallel ultrafast laser micro/nano fabrication with greatly increased efficiency and throughput.
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.