Laserthermia: a computer-controlled contact Nd:YAG system for interstitial local hyperthermia

Contact Nd:YAG laser surgery is assuming a role of greater importance in endoscopic and open surgery, allowing coagulation, cutting, and vaporization with greater precision and safety. A synthetic sapphire probe allows a wider angle of irradiation and diffusion of low power laser energy (less than 5 W) using an interstitial technique for producing local hyperthermia. Sensors placed directly into surrounding tissue or tumor continuously monitor temperature, and a pertinent computer program produces a controlled and stable temperature (e.g., 42 degrees C) over a period of time (e.g., 20-40 min). The Laserthermia system (Surgical Laser Technologies, Inc., Malvern, PA), using the Nd:YAG laser, offers many advantages in the experimental and clinical treatment of carcinoma by local interstitial hyperthermia.     

Induction of aberrant crypt foci and flat-type adenocarcinoma in the colons of dogs by N-ethyl-N''-nitro-nitrosoguanidine and their sequential changes

Dengue virus infections have been well known for many years; still dengue virus is regarded as an 'emerging' pathogen, as the disease profile is changing. Its geographical range and overall incidence, and the incidence of the associated complications, dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS), are on the increase. Modern-day travel and increasing urbanization seem to be the main contributing factors. In order to estimate the risk of infection during long-term stays in dengue-endemic countries, we tested sera obtained from 323 development aid workers and their family members who had spent on average 9.8 years in dengue-endemic regions for the presence of dengue virus antibodies. Dengue virus antibody screening was done by a commercially available immunofluorescence test (IF). Reactive samples were re-tested by an in-house IF and also tested for cross-reactivity to yellow fever virus using yellow fever IF and neutralization test (NT). Evaluation of the results revealed that the screening test has a specificity of at least 63.2%. In 12 of 19 initially positive cases crossreacting antibodies against yellow fever virus could be ruled out. Three cases remained indeterminable, whereas four of the reactive and 10 (out of 12) of the borderline reactive cases showed crossreactivity with yellow fever virus, probably due to previous vaccination. We found seroprevalence rates of 4.3% with no significant differences related to gender or area of upbringing. Seroprevalence rates were evaluated according to region of suspected or confirmed infection. In two cases the dengue infection had taken a classical clinical course; in another three cases an extraordinary febrile illness was reported in the history. None of the other seropositive individuals had a history of an illness possibly attributable to dengue virus infection. Our results show that there definitely is a risk for long-term expatriates to acquire (mostly non- or oligo-symptomatic) dengue infection, which might be important especially in the light of the supposed aetiology of DHF or DSS as a secondary infection with another dengue virus serotype.     

A Software Defined Radio Platform with Direct Conversion: SOPRANO

In this paper, a new software defined radio platform with direct conversionisintroduced.The platform is named SOPRANO, which stands for Software Programmableand Hardware Reconfigurable Architecture for Network.Main features of SOPRANO include a high-level design methodologyfor digital circuits, direct conversion based on six-port technology, andnovel digital signal processingalgorithms for multi-band and multi-mode operation.The first prototype of the SOPRANO platform has been built and was ableto receive M-ary PSK (Phase Shift Keying)and QAM (Quadrature Amplitude Modulation) signals,with two different carrier frequencies at 2.45 GHz and 5.25 GHz,by changing signal-processing software.     

Electrocatalysis Characteristics of a Polynuclear Cyanide Complex, Ruthenium Purple, for Dihydrogen Oxidation

An electrocatalytic dihydrogen oxidation was found to take place on an electrode coated with iron(III) ruthenocyanide (i.e., repeating unit cell structure: Fe^III ₄[Ru^II(CN)₆]₃ or MFe^III[Ru^II(CN)₆] and M = alkali metal counter ion) called ruthenium purple (RP). It was shown by voltammetric study that an electrocatalytic dihydrogen oxidation is induced on oxidizing the Fe^II ion in the cyanometallate. When the electrocatalysis characteristics of RP were investigated by voltammetry, especially in terms of the kinds of electrolyte used (K⁺ or Na⁺), RP exhibited a more efficient electrocatalysis in the K⁺ than in the Na⁺ electrolyte system. While a one-electron electro-oxidation of Fe^II to Fe^III occurs, there is also a release of hydrated alkali metal cation(s) from the anionic RP (i.e., reduced RP) to compensate for charge. Moreover, cation transport through the cyanometallate network is more facile for the K⁺ electrolyte system (cf., size of hydrated cation: Na⁺ at 0.36 nm lattice channel of RP at 0.35 nm > K⁺ at 0.24 nm). Therefore, it was most probable that the present electrocatalysis is kinetically dominated by the electro-oxidation.     

Characterization of mono- and multilayered films with Mn-doped ZnS nanoparticles and luminescence properties of the monolayered films prepared by applying magnetic fields

Mn²⁺-doped ZnS (ZnS:Mn) nanoparticles were prepared using bis(2-ethylhexyl) sulfosuccinate (AOT) reversed micelle method. Luminescence at 583-589 nm were observed in the ZnS:Mn nanoparticles and are ascribed to Mn²⁺ ion in the nanoparticles due to energy transfer from ZnS. The luminescence was enhanced by capping with alkanethiol. Mono-and multilayered films with the alkanethiol-capped ZnS:Mn nanoparticles were fabricated on quartz substrates by layer-by-layer method using self-assembled monolayer (SAM) of 1,6-hexanedithiol. The polarization degrees of luminescence for the monolayered films were enhanced by preparation under applying magnetic field. The enhancements are probably caused by magnetic orientation of the ZnS:Mn nanoparticles on the quartz substrates.     

XPS study of carbon nitride films deposited by hot filament chemical vapor deposition using carbon filament

Amorphous carbon nitride, a-CN_x, thin films were deposited by hot filament CVD using a carbon filament with dc negative bias voltage on the substrate. The effects of the negative bias and the filament components on the binding structure of the films are investigated by XPS. The composition ratio of graphite to amorphous carbon in the filaments affects the bonding structure of carbon and nitrogen in the films, although the nitrogen content in the films is almost same as 0.1. The nitrogen content in the films changes from 0.1 to 0.3 as the negative bias changes from 0 to − 300 V.     

Excess Solute Carbon and Tetragonality in As-Quenched Fe-1Mn-C (C:0.07 to 0.8 Mass Pct) Martensite

The carbon distribution behavior and crystal structure of as-quenched martensite in Fe-1Mn-C (C: 0.07 to 0.8 mass pct) steels were quantitatively investigated by atom probe tomography (APT) and X-ray diffraction with Rietveld analysis. APT revealed that the martensite steels contained quantities of carbon in solid solution far beyond its solubility in body-centered cubic (bcc)-Fe in all the alloys investigated; the carbon atoms were non-homogeneously distributed as carbides or aggregates on dislocations due to autotempering. Tetragonality was observed in the steels with interstitial solute carbon concentrations in the range of 0.1 to 0.7 mass pct, but was not evident below 0.1 mass pct. The appearance and disappearance of tetragonality in the low-carbon steels may be explained by the disordered bcc ? ordered body-centered tetragonal (bct) mechanism, considering the partial tetragonality due to the heterogeneity of the interstitial solute carbon distribution. The existence of tetragonality in the autotempered low-carbon steels can alternatively be understood by a mechanism based on the kinetic decrease of tetragonality during cooling, where the microscopic strain release is the rate-controlling process. The excess carbon solubility in the autotempered low- and medium-carbon martensite is due to the existence of tetragonal distortions, owing to the slow kinetics of the tetragonality decrease during cooling.

     

Pattern recognition using boundary data of component distributions

In statistical pattern recognition, a Gaussian mixture model is sometimes used for representing the distribution of vectors. The parameters of the Gaussian mixture model are usually estimated from given sample data by the expectation maximization algorithm. However, when the number of data attributes is large, the parameters cannot be estimated correctly. In this paper, we propose a novel approach for estimating the parameters of the Gaussian mixture model by using sample data located on the boundary of regions defined by the component density functions. Experiments are carried out to show the characteristics of the proposed method.     

Direct simulation of sound and underwater sound generated by a water drop hitting a water surface using the finite difference lattice Boltzmann method

The sound and underwater sound emitted from a water drop colliding with a water surface are simulated by a new model of the finite difference lattice Boltzmann method. The two-particle immiscible fluid model is modified to simulate sound in the gas phase and underwater simultaneously. In the very early stage after the collision, sounds propagating into the gas and liquid phases are successively detected, and the effects of drop shape and gas bubbles are also observed.