1,545 research outputs found

    Frequency Shifts Inherent in the 6328 a Helium-neon Laser

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    Frequency shifts inherent in helium neon lase

    Development of lasers for plasma diagnostics

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    Optical heterodyne system used to measure electron density of plasm

    NanoWalker: a fully autonomous highly integrated miniature robot for nanoscale measurements

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    The aim of this project is to develop the smallest and most sophisticated wireless fully autonomous instrumented robot capable of subatomic movements. The robot named 'NanoWalker' should bring a new paradigm in the way instruments are built while providing a sophisticated platform for a new range of applications. The project involves primarily the investigation of a new legged locomotion based on piezo-actuators with advanced micro-assembly techniques applied to complex embedded electronic systems; the development of new miniature instruments, micro-manipulators, integrated behavior for controlling, searching and scanning at the atomic scale; and the development of a subatomic navigation system. Besides all the new technologies and techniques that we intend to develop and which will be applicable to many areas and systems, the NanoWalker should provide a suitable yet more flexible and powerful platform compared to traditional macro-scaled instruments. It is anticipated that this new form of highly integrated autonomous microsystem will be used as the main building block for a new generation of measurement and inspection systems. In this paper, the main components of the NanoWalker are briefly described.Seaver Institut

    Urological procedures in Central Europe and the current reality based on the national registries of Czech Republic, Hungary, and Poland (2012 status)

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    INTRODUCTION: In recent years, the laparoscopic approach in oncologic urology seems more attractable to the surgeons. It is considered to have the same oncologic quality as open surgery, but is less invasive in patients. It is used widely in all of Europe, but with various frequency. The aim of the study was to present a various amount of oncourological procedures from three neighbouring countries - Poland, Czech Republic and Hungary. Prostatectomy, cystectomy, nephrectomy and tumorectomy (Nephron Sparing Procedures - NSS) were presented as a list of procedures prepared from the national registry. MATERIAL AND METHODS: The total amount of procedures was presented, as well as the LO (Lap to Open procedures) index, P/P (procedures/population) index, ratio of cystectomy/population, and cystectomy/TURBT. RESULTS: In the Czech Republic, the most complex procedures are performed (laparoscopic/robotic prostatectomy, NSS LAP, LAP nephrectomy) in the majority when analysing the country's population. In Hungary and Czech Republic, there are more laparoscopic/robotic radical prostatectomies performed, than open ones. In Poland the largest number of cystectomies is performed when analysing the country's population, but it is difficult to explain the much higher ratio of 6.57 TUR/one cystectomy. In the Czech Republic this procedure is performed in almost one quarter of the patients (23.36%). Interestingly, in Hungary the cystectomy with pouch creation is performed in about 67.65% cases. The highest reimbursement for surgical procedure is present in the Czech Republic with approximately 20-40% more than when compared to Poland or Hungary. CONCLUSIONS: The definitive leader in Central Europe (based on the national registry) is the Czech Republic, where the most complex procedures are performed (laparoscopic/robotic prostatectomy, NSS LAP, LAP nephrectomy) in biggest amounts when analysing the country's population. Explanation of such circumstances, can be the higher reimbursement rate for surgical procedure in this country

    Evaluating Children’s Advocacy Centers’ Response to Child Sexual Abuse

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    Children’s Advocacy Centers (CACs) play an increasingly significant role in the response to child sexual abuse and other child maltreatment in the United States. First developed in the 1980s, CACs were designed to reduce the stress on child abuse victims and families created by traditional child abuse investigation and prosecution procedures and to improve the effectiveness of the response. According to several experts (Fontana, 1984; Pence and Wilson, 1992; Whitcomb, 1992), child victims were subjected to multiple, redundant interviews about their abuse by different agencies, and were questioned by professionals who had no knowledge of children’s developmental limitations or experience working with children. Child interviews would take place in settings like police stations that would further stress already frightened children. Moreover, the response was hampered because the multiple agencies involved did not coordinate their investigations, and children’s need for services could be neglected

    Manufacturing methods for high density micro-channel arrays

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    Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.Includes bibliographical references (leaves 124-127).This thesis explores two distinct methods of micro-array manufacture for high throughput pharmaceutical scanning. The first method, impact shaping of polymers, is a novel, inexpensive way to form large numbers of small channels or wells in plastics. The impact method uses the kinetic energy from a ram to punch holes into a polymer sample without melting the bulk of the workpiece. The second method is electrical discharge machining (EDM) of silicon, which machines high aspect ratio holes arranged in high density arrays on silicon wafers. The method may be viewed as complementary to current plasma etching techniques and lithography. Several testing platforms were devised for the creation of the plastic well arrays based on the high speed ram principle. A modified Charmilles Roboform 30 machine was used to create the silicon arrays. While creating high volume manufacturing methods for will required additional work, both processes were fundamentally successful, producing individual arrays of acceptable quality. Both methods hold promise for manufacture of accurate, inexpensive, and useful replacements for current plate technology.by Luke Sosnowski.S.M

    Effect of the inoculum dose of three grapevine trunk pathogens on the infection of artificially inoculated pruning wounds

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    This study assessed the infection rates of different spore inoculum doses of the grapevine trunk pathogens Diplodia seriata, Phaeomoniella chlamydospora and Eutypa lata following artificial inoculation of pruning wounds. Potted vines of cv. Tempranillo were inoculated with doses ranging from 10 to 4000 conidia per wound of D. seriata and P. chlamydospora and led to recovery percentages of 10–100% for D. seriata and 16–94% for P. chlamydospora. Eutypa lata, when inoculated onto wounds of vines in a mature vineyard (cv. Shiraz) and on detached canes (cv. Cabernet Sauvignon) with a dose range of 10 to 1000 ascospores per wound, led to recovery percentages of 17–95%. In the field assay, there was no difference in recovery from wounds that were exposed to single or double inoculations with the same total spore dose, or between canes that were harvested 7 or 11 months after inoculation. The results obtained in this study showed significant variability in pathogen recovery between trials, comparable with that reported previously, which suggests that factors such as pathogen virulence, environmental parameters and experimental conditions may influence the infection process. According to this study, in order to obtain optimal recovery percentages of 50–70% for robust evaluation of pruning wound treatments, dose ranges of 100-1000 conidia of D. seriata, 100–2000 conidia of P. chlamydospora, and 100–500 ascospores of E. lata per wound would be required.Georgina Elena, Mark R. Sosnowski, Matthew R. Ayres, Pascal Lecomte, Celine Benetreau, Francesc Garcia-Figueres, Jordi Luqu

    Doxazosin induces apoptosis in PTEN–positive androgen-independent PC cells via inhibition of Akt activation

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    Doxazosin, a selective α1-adrenoreceptor antagonist widely used in the management of benign prostatic hyperplasia (BPH), has been shown to induce apoptosis in androgen-independent (AI) and PTEN (phosphatases and tensin homolog)-negative prostate cancer (PC) cells. The objective of this study was to assess the effects of doxazosin on the growth of PC cells with a functional PTEN/PI3K/Akt pathway in relation to cell androgen sensitivity and Bcl-2 expression. Material and methods. The DU145 cell line and two derivatives: 1) DKC9 [DU145 (Bcl2 +/+)] and 2) DAR19 [DU145 (AR+/+)] were used. The effect of doxazosin on i) cell proliferation and ii) Akt phosphorylation was measured using the MTT assay and Western blotting, respectively. Results. Doxazosin caused significant concentration, but not time-dependent, decrease in cell viability. The threshold of sensitivity to the compound differed between the cell lines and was the lowest in the parental cell line. In DAR 19 cells, AR-mediated signaling further increased cell resistance to doxazosin. In all cell lines, doxazosin-induced apoptosis was rescued by EGF stimulation and, in DAR19 cells, by AR activation. Doxazosin reduced basal and EGF-/DHT-induced Akt phosphorylation. Conclusions. This study demonstrates that doxazosin induces apoptosis in PTEN-positive AI PC cells, at least partially, via Akt deactivation and that over-expression of Bcl-2 or AR increases cell resistance to the drug. These results imply that translational potential of doxazosin depends on phenotypic characteristics of PC cells and provide evidence for limitations to its application in hormone refractory tumors

    High-carrier-density electron dynamics in low-temperature-grown GaAs

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    Pump-probe differential transmission measurements examine high-carrier-density phenomena in as-grown and annealed GaAs samples grown at temperatures from 210 to 270 °C. We observe trap saturation and Auger recombination, and accurately model the measurements on annealed samples with a simple two level rate equation, allowing us to extract the trapped-electron lifetimes. © 1997 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70634/2/APPLAB-70-24-3245-1.pd
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