Subacute myocardial infarction: assessment by STIR T2-weighted MR imaging in comparison to regional function

Purpose Increased T2 signal intensity (SI) can be regularly observed in myocardial infarction. However, there are controversial reports about the relationship of elevated T2 SI to myocardial viability and some authors propose that high T2 SI serves as a sign of irreversible myocardial injury. This study investigates increased T2 SI compared to myocardial function in patients with reperfused subacute myocardial infarction. Preserved function was used as criterion for viability. Methods Ten healthy volunteers and 17 patients with myocardial infarction and patent inlarct related coronary artery were examined on a 1.5 T Magnetom Vision system (Siemens). For T2-weighted MR imaging a breath-hold STIR sequence with dark-blood preparation was used. Cine FLASH 2D imaging was applied to assess myocardial function. Signal-to-noise (S/N) in STIR T2 images was measured in normal and infarcted regions and subsequently identified by two independent observers. Based on a 20 segment model of the left ventricle findings were compared to regional myocardial function. Results Elevated STIR T2 SI was found in all 17 patients and observed in 27% (204/754) of segments. S/N of normal myocardium was 5.1 ±0.7 in volunteers and 4.9 ± 0.8 in patients(P=NS). Infarcted myocardium presented with significantly-increased S/N 12.8 ± 1.9 (P < 0.0001). Significant transmural elevation of T2 SI was noted in 32% of segments with preserved systolic function. Conclusion Increased STIR T2 SI can be observed transmurally in post-ischemic myocardial regions with preserved function. It therefore cannot be used as an exclusive marker for the non-viable region.     

Priorities for Standards and Measurements to Accelerate Innovations in Nano-Electrotechnologies: Analysis of the NIST-Energetics-IEC TC 113 Survey

In 2008, the National Institute of Standards and Technology and Energetics Incorporated collaborated with the International Electrotechnical Commission Technical Committee 113 (IEC TC 113) on nano-electrotechnologies to survey members of the international nanotechnologies community about priorities for standards and measurements to accelerate innovations in nano-electrotechnologies. In this paper, we analyze the 459 survey responses from 45 countries as one means to begin building a consensus on a framework leading to nano-electrotechnologies standards development by standards organizations and national measurement institutes. The distributions of priority rankings from all 459 respondents are such that there are perceived distinctions with statistical confidence between the relative international priorities for the several items ranked in each of the following five Survey category types: 1) Nano-electrotechnology Properties, 2) Nano-electrotechnology Taxonomy: Products, 3) Nano-electrotechnology Taxonomy: Cross-Cutting Technologies, 4) IEC General Discipline Areas, and 5) Stages of the Linear Economic Model. The global consensus prioritizations for ranked items in the above five category types suggest that the IEC TC 113 should focus initially on standards and measurements for electronic and electrical properties of sensors and fabrication tools that support performance assessments of nano-technology enabled sub-assemblies used in energy, medical, and computer products.     

Investigations on the Laboratory Scale Separation of Mung Bean Starch

Mung bean starch is used as a high-grade raw material for noodle production in the food industry. Until now the applied separation techniques are often less efficient. Therefore, investigations were carried out on the laboratory scale to give first informations about the development of new separation techniques. The raw materials were flour and whole kernels. In both cases it was possible to produce a pure starch with a protein content less than 0.2% in dry matter. Physical and chemical investigations of the isolated starch pointed to the qualification of mung bean starch in different application fields, especially in view of the high viscosity.     

Gas Generator Development for Fire Protection Purpose

High effective Halon fire protection systems were introduced as a technical standard during many years. Because these substances are harmful to the ozone layer, this technology was prohibited. Looking for alternatives in a first step INERGEN or CO₂ pressure gas systems were applied, which show strong disadvantages with respect to extinguishing efficiency and toxicity. As a consequence a new gas generator concept is proposed, based on the idea to produce N₂ by a chemical reaction out of a solid gas generator. The technology enables small units of low mass with suitable escape characteristics of the gas. Within the presented work test results of a model formulation are described and discussed.     

Grundlagenuntersuchungen zur Herstellung von Emulsionen im Ultraschallfeld — Teil 2

The formation of emulsions by use of ultrasonication was investigated, particularly for low‐viscosity oils. The influence of the irradiated volume, power density, viscosity of the dispersed and continuous phases as well as the influence of the oil fraction on drop size were investigated. An equation based on turbulence theory can be used to predict the dependence of drop size on different process conditions and substance properties. Comparison with other methods shows that emulsification can be achieved with ultrasound just as efficiently.     

Burning Phenomena of the Gun Propellant JA2

The combustion phenomena of the standard gun propellant JA2 are investigated in experiments and analyzed by a simplified theoretical model. Hereby energy transfer from the gas phase governs ignition and combustion of solid rocket and gun propellants. In addition to the heat conduction and convection, the radiation of the flame contributes to the heat feedback which controls the burning rate in dependence on pressure. The dependence on the initial temperature is given by physical parameters of the conversion from the solid to the gaseous state. Burning rates are measured in dependence on pressure and initial temperature confirming a simplified law for the burning rate. The evaluation yields that the pressure exponent can be directly assigned to the heat feedback and that the temperature of the conversion from the condensed to the gas phase lies at about 675 K. The experiments also comprise spectroscopic measurements at low pressures in the wavelength ranges from 300 nm to 14000 nm which are resolved spatially along the vertical flame profile. The analysis of the spectra delivers the profiles of species in the flames including di‐atomic radicals and tri‐atomic molecules of the final combustion products. In addition, gas phase temperatures are derived by application of the Single‐Line‐Group model which gives approximately 2800 K closely below the adiabatic flame temperature of 2900 K at low pressures. They are compared to temperatures assigned to soot particle emission. In summary, these data enable an estimation of the heat feedback from the flame to the burning surface.     

Gas-Solid Hydroxyethylation of Potato Starch in a Stirred Vibrating Fluidized Bed Reactor

A novel reactor for modifying cohesive C-powders such as in the gassolid hydroxyethylation of semidry potato starch is characterized, the so-called stirred vibrating fluidized bed reactor. Good fluidization chracteristics are obtained in this reactor for certain combinations of stirring and vibration parameters. Channeling can be suppressed by stirring in the bed with equidistant flat blades whereas agglomerated are destroyed by vibration of the gas distributor. Also the complex sorption, diffusion and reaction behaviour of ethylene oxide in semi-dry starch was investigated. Reaction rate equations were obtained for all four parallel reactions involved: the catalyzed and uncatalyzed hydroxyethylation of starch and the catalyzed and uncatalyzed hydrolysis of ethylene oxide. By combining all results, a pressure-controlled stirred vibrating fluidized bed reactor could be designed for the gas-solid hydroxyethylation of potato starch. This process was optimized and compared to the classical slurry process. In our novel reactor the reaction time can be reduced at least by a factor of 10 relative to the slurry process whereas the selectivity is also higher. Products with a high molar substitution can be obtained by this novel process without loss of the granular structure of the starch.     

Design optischer Schichtsysteme

A logical approach to optical coatings, their design, manufacture, properties and application would be the dream of all users. Optical coatings are thought to be rather mysterious with the unexpected the norm and success depende? How can it be manufactured in large numbers of items under real conditions reproducibly and profitable? The article is a mixture of fundamental optics and practical design examples. The objective is the presentation of a logical unified treatment of the subject with emphasis throughout on understanding and reasoning.     

Photochemische Reaktionen von Pyrazolidon-(3)-betainen. IV. Photooxydation von Pyrazolidon-(3)-azomethiniminen

Photochemical Reactions of 3-Pyrazolidone Betains. IV. Photooxidation of 3-Pyrazolidone Azomethinimines Azomethinimines 1 , easily obtainable from 3-pyrazolidone and aldehydes, on dyesensitized photooxidation in methanol as a solvent undergo decomposition to nitrogen, methyl β-methoxypropionate 3 , methyl acrylate 4 and the corresponding aldehyde 2 . The formation of these products is interpreted by formation and decomposition of a cyclic peroxide 5 , produced by a 1,3-dipolar cycloaddition reaction between 1 and singlet oxygen. The photooxidation of 1 in acetonitrile produces: nitrogen, carbon dioxide, ethylene, β-propiolactone 9 , and the corresponding aldehyde 2 . The dye-sensitized photooxidation in methanol of the azomethinimines 16 , prepared from 3-pyrazolidone and ketones, gives the following products: nitrogen, methyl β-methoxypropionate 3 , methyl acrylate 4 , and the corresponding ketone, besides hydrazine and the corresponding α-methoxy-alkylhydroperoxides 17 and 21 . Key intermediate of the peroxide formation is the Criegee ozonization zwitterion which was trapped with acetaldehyde as an ozonide.