Surface Plasma Negative Ion Sources

The influence of electric fields and neutral particles on the plasma sheath at ITER divertor conditions

The plasma needle is a novel design of a radio-frequency discharge in helium/air mixtures at atmospheric pressure. The discharge contains neutral, excited and ionized particles, and emits ultraviolet (UV) light. It operates at low electric power and close to ambient temperature; it combines chemical activity with non-destructive character. Therefore it is expected that the plasma needle will be used in future in (micro) surgery, e.g. in wound healing and in controlled tissue removal through cell detachment or apoptosis, avoiding necrosis and in°ammation reactions. Focus of this study is both on optimization of needle design and on assessment of effects of plasma activity on living cells. This work is a pio- neering study of the effects of non-thermal plasma on biological samples. The design of the plasma needle was adjusted in such a way that instead of operating in a closed reactor, now the treatments could be performed in open air. Thus, larger samples could be treated and handling times were reduced. Then, a characterization of the needle was performed using electrical as well as optical diagnostics (Chapter 3). It was found that the needle operated at voltages of 140 Vrms and higher. A model was made to determine the resistance of the plasma and from this an estimation of the electron density could be made. The latter can be regarded as an indirect measure for plasma reactivity. Results from optical emission spectroscopy showed that reactive oxygen species, such as O¢ and OH¢, were produced in the plasma. Furthermore, UV emission was detected. Both the radicals and the UV are known to interact with cells and tissues. For applications, the amount of radicals that reach the sample or that are generated in the sample is important. For this reason, radicals were detected in liquid that was treated with plasma using a chemical technique (Chapter 4). It involved a fluorescent probe: the probe was dissolved in liquid and after reaction with specific radicals it became fluorescent. Radical density in the liquid depended on plasma conditions, treatment time, and amount of liquid used, but it was always in the micromolar range. These concentrations were found to be comparable with physiological concentrations that were stated in literature. Basic cell reactions after plasma treatment were determined by experiments on cultured Chinese hamster ovarian (CHO K1) cells (Chapter 5). One of these reactions was cell detachment: cells detached from their environment but remained alive after treatment. Other reactions included a small percentage of apoptosis and, when high plasma powers were used, necrosis. A comparison with the effect of UV light from UV lamps was made (Chapter 7). The main effect of UV treatment was necrosis, but only above a certain threshold value. For mammalian cells, this threshold was reasonably high. Thus, the ef- fects of plasma treatment could not be explained by the action of the UV light from the plasma. Quantitative experiments were performed on cultured bovine aortic endothelial cells (BAEC) and rat smooth muscle cells (A7r5) (Chapter 6). These two cell types constitute walls of blood vessels. It was shown that treatment times of less than one minute cause detachment of the cells if the layer thickness of the liquid that covered the cells was low (around 0.1 mm). This suggests that at short treatment times, the penetration depth of the plasma into the sample is limited. The percentage of necrotic cells was low after treatment. No difference was found in the detachment behavior of both cell types. Finally, pilot experiments were performed on carotid arteries of C57BL/6 and Swiss mice ex vivo (Chapter 8). They were studied using a two-photon laser scanning microscope (TPLSM). Cell nuclei, elastin bands, and collagen could be visualized. Preliminary results indicate that induced changes are not strongly dependent on applied energy if no heating e®ects are induced. Apparent effects were limited to the adventitia, probably due to a low penetration depth of active plasma species. In conclusion, we can state that the plasma needle is a non-destructive tool that can be ap- plied with precision. It has a superficial action and causes little damage to the tissue. The level of damage can be controlled to achieve a desired therapeutic effect. Both on cultured cells and on ex vivo arteries interesting effects were found that confirm the hypothesis that the plasma needle will have a future in surgery.

In fusion reactors, the walls are exposed to very high particle and energy fluxes. To study the problem of wall erosion and hydrogen retention in these conditions, the Magnum-PSI experiment at the FOM Institute of Plasma Physics is set up. The plasma source for Magnum-PSI is a cascaded arc, where a strong magnetic field is applied to obtain the desired conditions. The focus of this thesis is the development of a numerical model for studying the plasma creation in the source and the consecutive magnetized expansion. To describe the behavior of the different species in the range of conditions in the plasma – from gas to fully ionized, from non-magnetized to strongly magnetized – a multicomponent diffusion description is needed. Numerical techniques are developed to successfully apply multicomponent diffusion to magnetized expanding plasmas. Multi-component diffusion results in a system of coupled continuity equations for all species. In addition this coupled system is subject to mass and charge conservation constraints. To deal with the coupling between the species a new finite volume discretization method is introduced to discretize the system of continuity equations. For numerical stability, mass and charge constraints are not explicitly applied. Instead, all species mass fractions are treated as independent unknowns and mass and charge constraints are a result of the continuity equations, the boundary conditions, the diffusion algorithm and the new discretization scheme. With this method, mass and charge constraints can be satisfied exactly, although they are not explicitly applied. To verify the suitability of the method, simulations of both magnetized and nonmagnetized expansions have been performed. The simulations are able to reproduce important characteristics of magnetic confinement. Results show that in the magnetized case, the plasma production cannot be modeled by considering the source alone, since plasma production extends into the expansion region.

The effect of plasma on the transmission properties of electromagnetic waves and its application have always been one of the key research directions of electromagnetic theory and technology and plasma physics. The enhancement effect of collisional plasma on electromagnetic waves is a classic subject of the interaction between electromagnetic waves and plasma. Based on the transmission characteristics of electromagnetic waves in medium, this paper takes plasma as a special medium, and carries out experimental, theoretical and simulation studies on the transmission characteristics of high power microwave (HPM) atmospheric plasma and a certain range of electromagnetic waves under certain experimental conditions. The study found that the plasma formed by the S-band HPM under a vacuum of 50 Pa has a great influence on the electromagnetic wave transmission characteristics of different frequencies, and the electromagnetic wave transmission signal enhancement effect occurs regularly within a certain frequency range. A series of transmission waveforms of continuous electromagnetic waves of different frequencies passing through the HPM plasma area were obtained, and the waveforms were normalized. At 32.4 GHz, the transmission coefficient of continuous electromagnetic waves passing through the plasma area with plasma is about twice as high as that through the area without plasma. A simulation model was established, and the transmission coefficient distribution curve in the range of 31.5−32.5 GHz was obtained. The electromagnetic wave passing through the plasma showed a transmission enhancement effect, and at some frequency points, there was a transmission enhancement of about 1.9 times. The research results provides important technical support for the application of plasma in stealth, emergency communications, and black barrier communications.

Nuclear fusion, the merging of light nuclei into a heavier one, is an attractive future energy source. It is safe, produces no carbon-dioxide and its resources are practically unlimited. Currently, the most promising concept of nuclear fusion as a commercial energy source is the tokamak. In a tokamak, the hot plasma is confined by a torus shaped magnetic field. However, the plasma gradually diffuses outwards to the so-called scrapeoff layer and is guided to the divertor, the exhaust of a fusion device. In the divertor of ITER, a tokamak experiment under construction that has to demonstrate that fusion is a feasible energy source, an enormous heat flux density of around 10 MW m-2 and particle flux density of around 1024 m-2s-1 are expected. Pilot-PSI and Magnum-PSI, two linear plasma devices at DIFFER, are unique in producing the plasma conditions as expected in the ITER divertor in a well controlled and diagnosed set-up. Therefore, Pilot-PSI and Magnum-PSI are crucial for a successful divertor design for next generation tokamaks. Via computer simulations results of Pilot-PSI and Magnum-PSI can be translated to ITER. The wide ranges of time and length scales of the processes in the divertor make simulations very challenging. For simulation of neutral particles under ITER divertor conditions, a non-linear, kinetic Monte Carlo code is required. Hereto, Eunomia has been developed and coupled to the multi-fluid plasma code B2.5. Eunomia is a welldocumented, modular code with a modern fortran programming style, using objects and dynamic memory allocation. The challenging part of B2.5 simulations of Pilot-PSI and Magnum-PSI is to describe the low temperature, high density plasma beam in suitable boundary conditions. For Monte Carlo simulations of neutral species in a linear device the statistically most challenging region is the plasma region, in particular in front of the target. The aim for B2.5-Eunomia is to simulate both the geometries of linear devices and the scrape-off layer and divertor region of a tokamak and to improve understanding of the important physics in the ITER divertor conditions. Since for a new code validation is essential, Eunomia has been subjected to several test problems, such as Couette flow, to ensure correctness of neutral flow calculations. In addition, performance of several features of Eunomia has been tested, such as the parallel speedup and the algorithms reducing statistical noise. The importance of various collision processes has been studied. As expected, for Pilot-PSI conditions the neutral-neutral collisions and charge exchange collisions with a proton are of great importance. Although typically neglected, because of the small scattering angle, the elastic collisions between a proton and atomic and molecular hydrogen should be included at the relatively high pressure of several Pascals, created by the recycling plasma. The density distributions of excited hydrogen atoms and line-of-sight integrated Balmer emission profiles were calculated with a collisional-radiative model, using Eunomia results as input. Simulation of the vibrational states of the hydrogen molecule as separate species in Eunomia is crucial. The distribution of the molecules over the vibrational states strongly deviates from local thermal equilibrium, due to transport and dissociative processes. This has an impact on the shapes and intensities of the emission profiles. Comparison to spectroscopic measurements in Pilot-PSI showed reasonably good agreement in both the widths and amplitudes of the line integrated emission profiles of Balmer-a. However, the results are sensitive to uncertainties in the association probability of atoms at the vessel wall and the distribution of molecules, produced by this association process, over the vibrational states. B2.5-Eunomia has successfully been coupled and applied to the cylindrically symmetric geometry of Pilot-PSI. The vibrationally excited molecules efficiently recombine the plasma at the edge of the plasma beam, whereas atoms efficiently cool the plasma. Comparison of B2.5-Eunomia simulations to Thomson scattering measurements near the target of Pilot-PSI showed good agreement. B2.5-Eunomia could not reproduce the floating potential and the saturation current to the target quantitatively, however, the amount of biasing required to reach saturation of the total current to the target is reproduced. When the target in Pilot-PSI is floating, so when the total net current is zero, locally strong plasma currents run into and out of the target. B2.5-Eunomia results show current paths from the anode to the target, returning via the center of the plasma to the source. Furthermore, B2.5-Eunomia simulations show that saturation of the total current, as measured experimentally in Pilot-PSI for a biased target, is not a good indicator for obtaining the ion saturation current density over the whole target surface. Locally, at the center of the target, the ion saturation current is only reached when biasing the target 20 V more negative. Only when locally the ion saturation current density has been reached, the sheath potential will increase linearly with the bias potential. Further development of Eunomia, to improve the B2.5-Eunomia code package in the future, and additional benchmarking of B2.5-Eunomia have been discussed. The incorporation of the collisional-radiative model has been initiated. There remain no technical limitations to simulate other linear devices, as well as tokamak divertors, with B2.5-Eunomia.

Electrical Discharge Machining (EDM) is a well-known machining technique since more than fifty years. Its principle is to use the eroding effect on the electrodes of successive electric spark discharges created in a dielectric liquid. EDM is nowadays widely-used in a large number of industrial areas. Nevertheless, few studies have been done on the discharge itself and on the plasma created during this process. Further improvements of EDM, especially for micro-machining, require a better control and understanding of the discharge and of its interaction with the electrodes. In this work, the different phases of the EDM process and the properties of the EDM plasma have been systematically investigated with electrical measurements, with imaging and with time- and spatially-resolved optical emission spectroscopy. The pre-breakdown phase in water is characterized by the generation of numerous small hydrogen bubbles, created by electrolysis. Since streamers propagate more easily in a gaseous medium, these bubbles can facilitate the breakdown process. In oil, no bubbles are observed. Therefore, the breakdown mechanism in oil could be rather enhanced by particles present in the electrode gap. Fast pulses of current and light are simultaneously measured during the pre-breakdown. These pulses are characteristic of the propagation of streamers in the dielectric liquid. The pre-breakdown duration is not constant for given discharge parameters, but distributed following a Weibull distribution. This shows that the breakdown is of stochastic nature. After the breakdown, the plasma develops very rapidly ( 2·1018 cm-3 during the first microsecond). Then it decreases with time, remaining nevertheless above 1016 cm-3 after 50 μs. During the whole discharge, the density is slightly higher in the plasma center. The EDM plasma has such a high density because it is formed from a liquid, and because it is constantly submitted to the pressure imposed by the surrounding liquid. This extreme density produces spectra with strongly-broadened spectral lines, especially the Hα line, and with an important continuum. During the first microsecond when the density is at its maximum, spectral lines are so broadened that they are all merged into a continuum. The low temperature and the high density of the EDM plasma make it weakly non-ideal. Its typical coupling parameter Γ is indeed around 0.3, reaching 0.45 during the first microsecond. In this plasma, the Coulomb interactions between the charged particles are thus of the same order as the mean thermal energy of the particles, which produces coupling phenomena. Spectroscopic results confirm the non-ideality of the EDM plasma. The strong broadening and shift of the Hα line and its asymmetric shape and complex structure, the absence of the Hβ line, and the merging of spectral lines are typical of nonideal plasmas. The EDM plasma has thus extreme physical properties, and the physics involved is astonishingly complex.

INVESTIGATION OF INOSINE AND HYPOXANTHINE AS BIOMARKERS OF CARDIAC ISCHEMIA IN PLASMA OF NON-TRAUMATIC CHEST PAIN PATIENTS AND A RAPID ANALYTICAL SYSTEM FOR ASSESSMENT By Don E. Farthing, Ph.D. A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at Virginia Commonwealth University. Virginia Commonwealth University, 2008 Major Director: H. THOMAS KARNES, Ph.D. PROFESSOR, DEPARTMENT OF PHARMACEUTICS Each year in the U.S., approximately 7-8 million patients with non-traumatic chest pain visit hospital emergency departments (ED) for medical evaluation. It is estimated that approximately 2-5% of these patients are experiencing acute cardiac ischemia, but due to the shortcomings of current test methods, they are incorrectly diagnosed and discharged without appropriate treatment provided, thus leading to poor patient outcome and potential medical malpractice litigation. The goals of this research were to evaluate plasma samples xxvi for potential biomarker(s) of acute cardiac ischemia prior to heart tissue necrosis, and to ultimately develop a rapid method for detection of the potential biomarker(s) in human plasma. Initial experiments were performed using the mouse model, with subsequent evaluations on human plasma samples using high performance liquid chromatographic ultraviolet detection (HPLC-UV). The final phase of this research involved the development of a rapid luminometer test method (<10 min analysis time objective) to be potentially used in the clinical laboratory environment. An HPLC-UV detection method was developed and utilized for inosine, hypoxanthine and other adenosine triphosphate (ATP) catabolic by-products in KrebsHenseleit (Krebs) buffer solution, with analysis on perfusate samples from isolated mouse hearts undergoing 20 min acute global ischemia. The HPLC-UV method was modified for subsequent use on human plasma samples, obtained from hospital emergency department (ED) patients presenting with non-traumatic chest pain (potential acute cardiac ischemia) and from healthy normal individuals. The HPLC-UV (component quantification) and HPLC-MS (component identification) test methods utilized C18 column technology, mobile phases consisting of aqueous trifluoroacetic acid (0.05% TFA in deionized water pH 2.2, v/v) and methanol gradient to achieve component separation, with both utilizing simple sample preparations (e.g. direct injection of Krebs perfusate samples and centrifugal membrane filtration on plasma samples). Results of the animal experiments using isolated mouse hearts undergoing 20 min acute global ischemia demonstrated significant levels of endogenous inosine effluxed from the heart tissue, indicating its use as a potential candidate biomarker of acute cardiac xxvii ischemia. The HPLC results from human plasma representing ED non-traumatic chest pain patients demonstrated elevated levels of inosine (hypoxanthine precursor) and significant levels of hypoxanthine, which provided additional support for the use of these candidate biomarker(s) as a potential diagnostic tool for the initial acute cardiac ischemic event, prior to heart tissue necrosis. The final phase of this research focused on the development of a rapid, simple and sensitive chemiluminescence test method. Using a microplate luminometer with direct injectors and continuous mixing, the measurement of inosine and hypoxanthine in human plasma was achieved for healthy normal individuals and on patients with confirmed acute MI, with an analysis time of less than 5 minutes. The utility of this rapid luminescence technique would be the potential use at point-of-care (POC) services (e.g. hospital clinical laboratory or emergency medical services) as part of the initial ED treatment protocol on patients presenting with non-traumatic chest pain and signs/symptoms of acute myocardial ischemia or acute MI.

Objective The formation of edema in children with nephrotic syndrome (NS) will involve both of the underfill and overfill mechanisms. It has been recognized that there is a variety of changes in the plasma volume in NS patients. The present study was designed to determine whether the pulmonary capillary wedge pressure (PCWP) could reflect the changes of the plasma volume in NS children. Methods PCWP was measured by using echocardiography techniques, detecting plasma atrial natriuretic factor (ANF, radioimmunoassay method) and hematocrit in 14 NS children, 5 poststreptococcal glomerulonephritis children and 10 normal controls. Results (1) In the edema phase compared with the remission phase, 4 of 14 NS children showed an increased PCWP, which was accompanied by an increased ANF and a decreased HCT; 3 of 14 showed a decreased PCWP, which was accompanied by a decreased ANF and an increased HCT; the rest of 7 NS children showed no change in PCWP along with the other indexes. There were no significant differences in the levels of PCWP, ANF and HCT between the NS children in the remission phase and the normal controls. PCWP was positively correlated with ANF (r=0.76 P<0.001)and negatively correlated with HCT (r=-0.61 , P<0.001). There was a negative correlation between ANF and HCT(r=-0.59 , P<0.001). (2) Fifteen minutes after the infusion of 6% low molecular dextran which would induce the central volume expansion, PCWP was increased [(13.0±2.0) mm Hg] when compared with that [ (10.5±2.8) mm Hg, P<0.01] before the infusion in 9 NS children in the edema phase. Most of them did not present remarkable changes in their heart rates and blood presures except for one who had increased PCWP (from 14.0 mm Hg to 16.9 mm Hg) and manifested with dysphoria, oppressed, hypertention and tachycardia. The symptoms were improved by the active diuretic treatment. Conclusions PCWP measurement with the echocardiography in NS patients could indirectly assess the plasma volume and help to work out the therapeutic strategy for the treatment of edema in NS children. Key words: Nephrotic syndrome; Pulmonary wedge pressure; Atrial natriuretic factor; Hematocrit

Band Structure, Alan T. Collins Diamond Morphology, Robert E. Clausing Mechanical Properties of Diamond, Diamond Films, Diamond-Like Carbon, and Like-Diamond Materials, Peter J. Gielisse Surface Properties of Diamond, Mark P. D'Evelyn Thermal Properties Heat Capacity, Conductivity, and the Thermal Coefficient of Expansion, V. I. Nepsha Thermal Measurement Techniques, John E. Graebner Optical Properties, Alexander M. Zaitsev Electrical and Electronic Properties, Alexander G. Gontar Characterization Characterization Methods, Karen McNamara Rutledge and Karen K. Gleason Mined Diamond Natural Diamond, Henry O. A. Meyer and Michael Seal Theory Theory of Diamond Chemical Vapor Deposition, David G. Goodwin and James E. Butler Modeling and Diagnostics of Plasma Reactors Introduction, A. Gicquel Basic Processes in Plasmas Under Conditions Typical for Diamond Deposition, A. Gicquel Basic Processes: Plasma/Surface Interactions, A. Gicquel The Boltzmann Equation, Matt Gordon Flow Modeling for a Plasma Assisted Diamond Deposition Reactor, K. Hassouni, C. D. Scott, and S. Farhat Electromagnetic Field Modeling of Diamond CVD Reactors, Timothy A. Grotjohn Modeling of the Diffusional Transport of an H2 Plasma Obtained Under Diamond Deposition Discharge Conditions, K. Hassouni, C. D. Scott, and S. Farhat Spatially Resolved Spectroscopic Analysis of the Plasma, A. Gicquel, M. Chenevier, and M. Lefebvre Methods of Chemical Vapor Deposition Growth Hot-Filament CVD Methods, Alberto Argoitia, Christopher S. Kovach, and John C. Angus Microwave Plasma Chemical Vapor Deposition of Diamonds, Peter K. Bachmann Diamond CVD Using Radio-Frequency Plasmas, Steven L. Girshick Synthesis of Diamond, Mark A. Cappelli Low Temperature CVD, Akimitsu Hatta and Akio Hiraki Structural Modification of Diamond Nucleation and Epitaxy, S. P. Bozeman, B. R. Stoner, and J. T. Glass Ion Implantation of Diamond and Diamond Films, R. Kalish and S. Prawer Processing, Victor G. Ralchenko and Sergei M. Pimenov Applications of Industrial Diamond Abrasive Applications of Diamond, K. Subramanian and V. R. Shanbhag Active Devices, David L. Dreifus and Bradley A. Fox Applications of Diamond in Computers, Richard C. Eden Diamond Vacuum Electronics, George R. Brandes Special Applications, Naoji Fujimori Cutting and Wear Applications, R. A. Hay and J. M. Galimberti Economics Economics and Commercialization, Adam T. Singer and John V. Busch

Background and Aims: The aim of this study was to retrospectively analyze use of argon plasma coagulation in lesions of the gastrointestinal tract. Materials and Methods: Data of 92 patients treated with an argon plasma coagulation system in the upper and lower gastrointestinal tract between May 2005 and November 2006, using a VIO argon plasma coagulation device (VIO 300 D with argon plasma coagulation 2; Erbe Elektromedizin, Tubingen, Germany; pulsed argon plasma coagulation, 20?120 W), were reviewed and analyzed. Results: Ninety-two patients were treated with argon plasma coagulation, and the mean age was 61.84 (3-91) years. Fifty of these patients were male (54.3%) and 42 (45.7%) were female. Ninety-two patients were treated in 155 sessions. The mean number of treatment sessions required was 1.68 (1?12). Indications were vascular lesions (24 patients), bleeding peptic ulcers or prevention of bleeding recurrence (19 patients), adjunctive therapy after piecemeal resection of colonic polyps (17 patients), palliative treatment of gastrointestinal tract cancers, treatment of bleeding after polypectomy or biopsy (11 patients), ablation of inlet patch (11 patients), ablation of Barrett?s esophagus (5 patients), radiation proctopathy (4 patients), and metallic stent cut (1 patient). There were no major complications observed. Minor complications were seen in only five patients (bleeding in 2, chest pain in 1, anal pain in 2 patients). Conclusions: Argon plasma coagulation system was an effective and safe method in various gastrointestinal pathologies.

Characteristics of low NOx burner is investigated. Low NOx burner introduced in this paper adopts two staged combustion with plasma burner for the 1st stage combustion. Extensive parametric tests were done to figure out the effect of burner stoichiometry, staged thermal load, electric power for plasma generation. Overall NOx production by burner shows effective reduction by adopting plasma staged burner. and the aspects depends on the fuel stoichiometry of 1st stage burner or operating condition of plasma burner. It is promising to use plasma burner as an alternative tools of low NOx burner technology.

Background: Strategies to expand access to routine HIV monitoring assays in resource limited settings (RLS) include the use of point-of-care (POC) tests and dried blood spots (DBS) collected at remote settings and shipped to central laboratories for testing for viral load (VL) testing. Currently access to CD4 testing is gradually expanding due to the emergence of relatively rapid, instrument-based POC tests. There are also instrument-free CD4 tests in the pipeline among which is VISITECT CD4 test, a semi-quantitative lateral-flow based technology. Though few near POC VL tests are commercially available currently and a few in the pipeline, these have not yet had much impact on the total level of VL monitoring in resource-poor settings they. As a result, the use of DBS is suggested as interim option for expanding access to VL testing in RLS. However, due to inclusion of HIV nucleic acids from white blood cells rather than only plasma HIV RNA, many studies reported its lack of accuracy to diagnose anti-retroviral therapy (ART) failure when used in most RT-PCR platforms <br> Aims: The broad aim of this thesis was to enhance access to HIV monitoring assays in RLS by improving performance and utility of assay technologies/methods. Specific aims included; studying the modified use of the standard VISITECT CD4 test for TB/HIV co-infected patients who need a different cut-off for timing of ART initiation, and development of a filter paper-based method of plasma separation (referred to as Filtered and Dried Plasma, FDP) from whole blood to enhance accurate quantification of HIV VL in RLS. <br> Methods: Experiments were conducted to investigate the potential use of test/reference ratio values generated by AX-2 reader of VISITECT CD4 test for TB/HIV co-infected <br> patients ART initiation (Chapter 2). In Chapter 4, different filtration materials (filter papers and biological reagents) and approaches were examined to develop a novel plasma separation method, known as Filtered and Dried Plasma (FDP). Proof-of-concept experiments to evaluate the new method efficiency in removing blood cells and generating cell-free plasma were also conducted. A prospective study to evaluate the performance of FDP in HIV VL quantification was performed using clinical samples (Chapter 5). Furthermore, long term storage stability of FDP was studied in laboratory conditions (Chapter 6). <br> Results: Only preliminary experiments that pinpoint a potential approach where modification of VISITECT CD4 test can be made were conducted and presented in Chapter 2. A preferred method (FDP) to DBS has been developed using filter papers that demonstrated effective elimination of RBCs and 93% of WBCs (Chapter 4). The prospective study (Chapter 5) demonstrated its accurate detection of treatment failure at the current cut-off (1000 cps/ml). Storage stability studies demonstrated adequate stability of FDP both in the pre and post- sample application storage (Chapter 6). <br> Conclusion: This thesis highlighted the diagnostic challenges in HIV/AIDS management, and strategies to enhance access and utility of diagnostics in RLS. Limited work were done and presented under the aim to investigate the modified use of VISITECT CD4 test (Chapter 2) due to delays in the final manufacturing product. The prototype plasma separation method, FDP, demonstrated efficient performance in HIV VL quantification and stability giving the promise to be used as the preferred dried sample for VL testing in RLS.

Determine the minimum concentration of plasma fibrinogen needed to stimulate the aggregation of platelets, collected from normal subjects, using ADP. Platelet rich plasmas (300 x 10(9) platelets/L) were made and adjusted to final fibrinogen concentrations of 75, 19, 5, and 0 mg/dL using fibrinogen free serum. Each fibrinogen concentration in all twelve subjects was aggregated with ADP SETTING: Research laboratory in the Department of Clinical Laboratory Science at Saint Louis University. Twelve healthy volunteers of both genders, between the ages of 18 and 60 years who were not pregnant and weighed at least 110 pounds were included in the study. Subjects were excluded from the study if they had ingested aspirin within one week prior to blood collection. In addition, subjects with a history of bleeding disorders such as afibrinogenemia, hypofibrinogenemia, von Willebrand disease, and Bernand-Soulier disease were rejected from the study. Platelet aggregation tracings were analyzed for amplitude and compared across plasma fibrinogen concentrations. In addition, the type of curve (monophasic vs. biphasic), smoothness and aggregation stability were also noted. The results show that aggregation occurred with every dilution of fibrinogen tested and that the amplitude of the aggregation curves appears not to be dependent on plasma fibrinogen. The results indicate that platelets from healthy individuals previously exposed to normal fibrinogen levels will aggregate equally well in decreasing plasma fibrinogen concentrations and even in the absence of plasma fibrinogen using ADP as the aggregator.

ALICE is a dedicated heavy-ion experiment at CERN LHC aiming to study the properties of the quark–gluon plasma. A lead– lead collision might produce several ten thousand new particles. Detailed study of the event requires precise measurements of the particle tracks. A 90 m Time Projection Chamber (TPC) with more than 500 000 read-out pads was built as the main central barrel tracker. Collisions can be recorded at a rate of up to about 1 kHz. The front-end electronics, designed from FPGAs and custom ASICs, performs shaping, amplification, digitisation and digital filtering of the signals. The data is forwarded to DAQ via 216 1.25 Gb/s fibre-optical links. Configuration, control and monitoring is done by an embedded Linux system on the front-end electronics. First results on the performance of the front-end electronics and the distributed detector control system are presented. I. TIME PROJECTION CHAMBER (TPC) The A Large Ion Collider Experiment (ALICE) [1] is using a TPC [2] as the main track-finding detector. A TPC is a gaseous detector. It is shaped like an horizontal barrel and positioned in the same direction as the beam pipe, which is passing through the centre of the barrel. The overall length is 500 cm, divided by a 100 kV Central Electrode (CE) into two identical drift volume. The diameter is 494 cm, though the innermost 170 cm is not part of the TPC to make room for the beam pipe and inner tracking detectors. A schematic view of the TPC can be seen in Figure 1. Collisions will take place in the beam pipe in the centre of the TPC, allowing the particles produced to traverse the TPC and leave tracks of ionised gas along their paths. A strong electric field of from the CE will make the electrons drift towards the end planes, where data read-out is performed. Each end plane is divided into 18 azimuthal sectors, which again are divided into two Multi-Wire Proportional Chambers (MWPC), the Outer and Inner Read-Out Chamber (OROC/IROC). The OROC has four Read-out Partitions (RPs); the IROC two. A RP is an electronic entity for reading out data from read-out pads. The ionistic signal will be amplified by the space charge around the wires of the MWPC. The induced charge on the read-out pads is forwarded to the read-out electronics. In total for both sides there are 557568 pads. The drift volume is filled with counting gas composed of 85.7 % Ne, 9.5 % CO2 and 4.8 % N2. A cold, light gas is used to assure low diffusion and low multiple scattering. Field distortions are minimised because of the high ion mobility and few ionisation electrons per unit length. The electronics design noise figure is 1000 RMS e− (700 actually achieved); not limiting the position resolution will require a signal/noise ratio of at least 20. Apart from tracking—measuring the charged particle momentum and having a good two-track separation—it also provides Particle IDentification (PID). The TPC is expected to perform well at multiplicities as high as dNch/dη=8000 in the particle momentum range [0.1, 100] GeV/c and within |η| 90 %, and the dE/dx resolution better than 10 %. Further, the TPC alone will have a momentum resolution of about 1 % at 2 GeV/c and 10 % at 50 GeV/c. For p–p collisions a read-out rate of ≈1 kHz is expected, while for central Pb–Pb collisions ≈0.2 kHz. Figure 1: Schematic view of the TPC. To the left a singe Read-out Partition (RP) is enlarged for visibility. The support for the sectors is shown on the two end planes. Between them is the Central Electrode (CE). The TPC allows space around the centre of the length axis for beam pipe and inner silicon detectors. II. DATA READ-OUT DESIGN As already mentioned, each sector has six RPs. A RP consists of a Read-out Control Unit (RCU) with up to 25 Front-End Cards (FEC), depending on the radial location. The innermost RPs have the highest number of FECs, as a smaller size for the readout-pads is used to increase the resolution to take into account the higher track density close to the collisions. The electronics for one RP, as well as its connection to the central systems is shown as a block diagram in Figure 2. Eight ALICE TPC Read-Out (ALTRO) [3] chips are mounted on a FEC, each capable of reading out 16 read-out pads. The FECs are attached to the RCU via buses; one for data transfer and one for control/monitoring. Once on the RCU, the data is forwarded to Data Acquisition system (DAQ) and the High Level Trigger (HLT) via a 1.25 Gb/s optical fibre. A Detector Control System (DCS) board equipped with an embedded

Introdução: O angioedema hereditário é uma doença rara, autossómica dominante, que se manifesta por crises súbitas, recorrentes e de gravidade variável de edema subcutâneo e submucoso. Estes episódios podem ocorrer de forma espontânea ou em resposta a triggers. São conhecidos três tipos de angioedema hereditário. A doença é condicionada por diminuição do nível plasmático de inibidor de C1 e aumento da bradicinina, com aumento da permeabilidade vascular e consequente edema. O objectivo deste trabalho é apresentar um protocolo para manuseamento perioperatório dos doentes com angioedema hereditário. Métodos: Realizámos uma revisão bibliográfica em três bases de dados, com os termos de pesquisa “hereditary angioedema” AND “anesthesia”. Foram incluídos artigos com menos de 10 anos e em inglês. No total obtivemos 58 artigos, foram selecionados 22. Resultados: Existem vários fármacos disponíveis para a abordagem do angioedema hereditário: o concentrado de inibidor de C1, plasma humano/plasma fresco congelado, androgéneos atenuados, anti-fibrinolíticos e moduladores do sistema de contacto. A profilaxia das crises pode ser efectuada a longo prazo, nos doentes com sintomas frequentes ou severos, e a curto prazo, antes de procedimentos dentários, médicos ou cirúrgicos. O tratamento das crises agudas é efectuado em meio intra ou extra-hospitalar. Discussão: A maioria dos artigos incluídos são descrição de casos clínicos individuais ou revisão dos casos de uma instituição. Várias medidas devem ser tomadas no período perioperatório de forma a evitar uma crise aguda. A profilaxia deverá ser realizada durante a gravidez antes de qualquer procedimento cirúrgico, nos procedimentos dentários (exceto limpeza dentária ou restauração simples), quando a cirurgia envolve manuseamento da via aérea, nos doentes com episódios prévios de angioedema afectando a via aérea e quando há estimativa de alterações significativas da volémia. Devido ao risco de crise de angioedema no pós-operatório, estes doentes devem permanecer numa unidade com vigilância permanente. Conclusões: Um dos potenciais triggers para uma crise de angioedema hereditário é o trauma anestésico e cirúrgico. Torna-se fundamental adoptar medidas para prevenção do angioedema e diminuição da morbimortalidade. Qualquer caso suspeito deverá ser referenciado para o Serviço de Imunoalergologia de um dos centros de referência.