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The use of tantalum as adhesion layer for Au/Si eutectic bonding was investigated and compared to the frequently used materials chromium or titanium in the case of oxidized silicon substrates. Suitable test structures have been fabricated, bonded and evaluated. The eutectically bonded chips were characterized in respect to the maximum bearable tensile and shear loading. Interfacial reactions were observed by SEM and optical microscopy. As a significant result when tantalum was used, the external load until fracture occurred could be increased up to a factor of 3 in comparison to usually applied chromium or titanium. Analyses after bonding gave no prove for diffusion between the metallic alloy and the adhesion layer and delamination could be minimized therefore. [ABSTRACT FROM AUTHOR]

A low-cost, polymer-based microfluidic platform is described that not only includes passive microfluidic parts, but also pumps based on an on-chip electrochemical gas generation by electrolysis. A hydrogel is used as electrolyte material, which allows a simple fabrication process by screen printing or stencil printing. Test structures were designed and fabricated to illustrate the feasibility of the approach for batch processing. Microfluidic chips including reservoirs and channel structures were fabricated by microinjection molding and used to demonstrate the movement of liquids inside microchannels by the proposed micropumps. The channel system was furthermore functionalized by a plasma surface treatment to form hydrophobic and hydrophilic areas. For sealing of the channel system, as well as for bonding the microfluidic part to glass-like sensor parts, laser-cut adhesive tapes were applied. [ABSTRACT FROM AUTHOR]

Infrared spectra of multiple frustrated total internal reflection and transmission for silicon wafers obtained by direct bonding in a wide temperature range (200–1100°C) are studied. Properties of the silicon oxide layer buried at the interface are investigated in relation to the annealing temperature. It is shown that the thickness of the SiO2 layer increases from 4.5 to 6.0 nm as the annealing temperature is increased. An analysis of the optical-phonon frequencies showed that stresses in the SiO2 relax as the annealing temperature is increased. A variation in the character of chemical bonds at the interface between silicon wafers bonded at a relatively low temperature (20–400°C) is studied in relation to the chemical treatment of the wafers’ surface prior to bonding. Models of the process of low-temperature bonding after various treatments for chemical activation of the surface are suggested. [ABSTRACT FROM AUTHOR]

Frequency selective vibration sensors for wear state recognition have been fabricated using surface near silicon bulk micromechaning (SCREAM). Capacitive detection combs convert the mechanical vibration into an electrical signal. Operating in a frequency selective resonant mode allows direct extraction of spectral information without Fourier transformation. To enlarge the measurement range they provide a frequency tuning capability by stress-stiffening which is achieved by electrostatic forces. Using force enhancing lever mechanism frequency variation of up to 100% of the base frequency has been measured with tuning voltages of 50 V. By arranging multiple cells with stepped base frequencies and overlapping tuning ranges the covered frequency range is widely extended. A fabricated array of ten cells is capable to continuously scan the range from 1 to 10 kHz. [ABSTRACT FROM AUTHOR]

Levels of plasma daunorubicin, daunorubicinol and aglycone metabolites were measured in 47 patients 3 h after daunorubicin was administered daily for three days as part of a cytosine arabinoside/daunorubicin remission induction regimen. High-pressure liquid chromatography with fluorescence detection was used for separation and quantitation of the drug and its metabolites. A wide range of plasma levels were observed regardless of the outcome of therapy. Patients who had high levels of the drug, or daunorubicinol on day 1 of therapy tended to have high levels on days 2 and 3 of the regimen. Three hours after the third daily dose of daunorubicin was administered, patients who would not enter remission had significantly higher levels of aglycone metabolites in plasma than did patients who entered remission. These data indicate that resistance to chemotherapeutic effects of daunorubicin may be connected with metabolism of the drug, especially with enhanced metabolism to aglycones. [ABSTRACT FROM AUTHOR]

A simple method was developed for the routine monitoring of daunorubicin (DR) or adriamycin (ADR) and of their chief fluorescent metabolites in plasma of cancer patients. The plasma samples were treated with ethanol: hydrochloric acid mixture, following which the drug and its metabolites, released to the 40,000 g supernatant, were analyzed by HPLC. A mu-bondapak-phenyl column was used and an isocratic mobile phase consisting of acetonitrile in 0.1 M ammonium-formate buffer at pH 4.0. Average recovery of all the tested compounds within the concentration range of 17-3,450 pmol/ml plasma was 108 +/- 5% (mean +/- SD). The method was applied to analyses of plasma samples of several patients treated with DR or ADR. At 3 h after treatment with a DR dose of 45 mg/m2 or 60 mg/m2, daunorubicinol was the major metabolite and its concentrations were 46-270 or 85-305 pmol/ml, respectively; the unchanged drug was present at concentrations of 16-99 or 30-101 pmol/ml, respectively. Deoxydaunorubicinolone and deoxydaunorubicinone were detected at concentrations ranging from 0 to 89 pmoles/ml in the plasma of some patients. Plasma of patients treated with ADR (30 mg/m2) contained adriamycinol as the main detectable metabolite, but at 3 h after treatment its concentration was usually lower than that of the unchanged drug (22 +/- 9 vs 53 +/- 16 pmol/ml). Traces of 7-deoxyaglycones were detected in some plasma samples. [ABSTRACT FROM AUTHOR]

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Copyright of Canadian Anaesthetists' Society Journal is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)