Sealing of packaging sheets using high-frequency techniques

The packging industry seals mainly with heat-contact (HC) techniques, but is using ultrasonic (US) techniques more and more. Less widely practiced are high-frequency (HF), which are used in only a few cases. High-frequency techniques have two different working principles: the dielectric principle and the inductive principle. The dielectric principle was first applied in manufacturing plastic (particularly PVC) clothing, while the inductive principle is used in the heating of metals in a high-frequency electric field, for instance in hardening and refining steel. Nowadays, these techniques are often used in the automobile, clothing, and pharmaceutical industries, and in manufacturing office equipment and sports articles. The Swiss Packaging Institute (SVI) and EMPA have recently started a research project on this subject that will study potential examples of the application of these techniques in modern packaging. The preliminary study of the literature is now completed and is reported here.     

Assessment of antifungal activities of fluconazole and amphotericin B administered alone and in combination against Candida albicans by using a dynamic in vitro mycotic infection model

We evaluated the pharmacodynamic activities of fluconazole and amphotericin B given alone and in combination against Candida albicans by using an in vitro model of bloodstream infection that simulates human serum pharmacokinetic parameters for these antifungals. Fluconazole was administered as a bolus into the model to simulate regimens of 200 mg every 24 h (q24 h) and 400 mg q24 h. Amphotericin B was administered at doses producing the peak concentration (2.4 micrograms/ml) observed with a regimen of 1 mg/kg of body weight q24 h. A combination regimen of fluconazole (400 mg q24 h) and amphotericin B (1 mg/kg q24 h) administered simultaneously and as a staggered regimen (amphotericin B bolus given 8 h after fluconazole bolus) was also simulated in the model to characterize possible antagonism between these agents. Fluconazole alone and amphotericin B alone demonstrated fungistatic (< 99.9% reduction in numbers of CFU per milliliter from the starting inoculum) and fungicidal (> 99.9% reduction) activity, respectively. When fluconazole and amphotericin B were administered simultaneously, fungicidal activity similar to that observed with amphotericin B alone was observed. Staggered administration of fluconazole and amphotericin B, however, resulted in a substantial reduction of the fungicidal activity of amphotericin B, producing fungistatic activity similar to that observed with noncombination fluconazole regimens. These results demonstrate the usefulness of this model for comparing the in vitro pharmacodynamic characteristics of different antifungal regimens and support the theory of azole-polyene antagonism. The effects of this antagonism on the in vivo activity and clinical usefulness of combination antifungal therapy, however, remain to be determined.     

Fibrinogen and cardiovascular risk

We trained 24 rats to perform an eight-arm radial maze task and then assigned them with a matching procedure to one of three treatments: sham surgery or lesions of the projection areas of the mediodorsal thalamic nucleus (MDn) in the medial wall (MW) or in both the MW and rhinal sulcal (RS) areas of frontal cortex. After recovery we trained the rats to perform six tasks, beginning with the standard eight-arm task, followed by two versions of a four forced choice procedure, and then three versions of a two-choice delayed-nonmatching-to-sample (DNMTS) task. The two lesion groups performed comparably on all tasks, showing that impairments were not exacerbated by extension of the MW lesion to include all cortical areas innervated by MDn. As in previous studies, frontal animals performed the radial maze task poorly immediately after surgery but improved with subsequent training. Controlling the order of the arm entries by opening the first four gates in a random sequence had little effect on performance, although frontal animals were impaired when lengthy delays (5 or 15 min) were imposed after the last of the four forced entries. Frontal animals were not impaired on two-choice DNMTS when the arms used for training were selected at random from the eight alternatives on a trial by trial basis, even when visual cues were eliminated by darkening the room and covering the maze. Frontal animals were significantly impaired when the selection of sample and choice arms was limited to the same two alternatives on every trial. This finding may explain the reported sensitivity of DNMTS to the effects of frontal lesions when training is carried out in operant chambers.     

Accurate determination of chemical composition of urinary calculi by spiral computerized tomography

PURPOSE: Choice of efficacious clinical management of symptomatic renal calculi can be facilitated by ascertaining the precise chemical composition of the calculus. Spiral computerized tomography (CT) is becoming a frequently used radiographic examination to establish the diagnosis and severity of calculus disease. Our objective for this study was to determine the precision of spiral CT in identifying the chemical composition of 6 different types of urinary calculi with region of interest measurements using spiral CT. MATERIALS AND METHODS: A total of 102 chemically pure stones were separated into 6 groups. The stones along with phantoms containing butter (fat) and jello (water) were mounted vertically in the scanner gantry. Then 1 mm. thickness scanning was performed with a high speed scanner at the 2 energy levels of 80 and 120 kV. The determination of the chemical composition was performed using the absolute CT value measured at 120 kV. and the dual kilovolt CT values measured at 80 and 120 kV. Hounsfield unit at 80 kV.-Hounsfield unit at 120 kV.). RESULTS: The absolute CT value measured at 120 kV. was able to identify precisely the chemical composition of uric acid, struvite and calcium oxalate stones. It was imprecise in differentiating calcium oxalate from brushite stone and struvite from cystine stone. However, dual kilovolt CT value was able to differentiate these latter stones with statistical significance (p < 0.03). Uric acid stones were easily differentiated from all other stones using the absolute CT value. CONCLUSIONS: This study demonstrates that the chemical composition of urinary calculi can be accurately determined by CT scanning in an in vitro setting.     

Assessment of the Primary Structure of Slabs and the Influence on Hot‐ and Cold‐Rolled Strip Structure

The quality of the delivered strips depends ‐ among other things ‐ on the internal structure of the slabs. Solidification phenomena as micro‐ and macro‐segregation are of particular importance. This paper deals with the micro‐ and macro‐segregations in slabs of the steel grades DP and S355. The method for the investigation of segregations based on electron probe microanalysis is described in brief. Characteristic values of segregations are derived from quantitative element distribution images. These results serve as a basis for decisions on further processing steps in the hot and cold rolling mill.     

Differential temperature regulation of three sunflower microsomal oleate desaturase (FAD2) isoforms overexpressed in Saccharomyces cerevisiae

The oxygen‐independent temperature regulation of three sunflower microsomal oleate desaturase (FAD2) isoforms has been investigated using Saccharomyces cerevisiae cells expressing each FAD2 gene. Yeast cells transformed with the FAD2‐1 gene showed the highest percentage of dienoic acids when they were grown at 10–15 °C. In contrast, the maximal level of dienoic acids for S. cerevisiae cells expressing the FAD2‐2 and FAD2‐3 genes were obtained at 30 and 35 °C, respectively. Temperature shifts in the phase of exponential growth, from 30 to 15 °C or from 15 to 30 °C, produced changes in the final percentage of dienoic acids, mostly in yeast cells transformed with the FAD2‐1 gene, to reach the content corresponding to the new temperature. Low temperature (15 °C) increased the amount of neutral lipids in all transformed yeast cells, mainly because it favored triacylglycerol accumulation. In addition, the FAD2‐expressing yeast cells showed a higher polar lipid content than those transformed with the empty vector. Dienoic acids were present in all lipids, although high temperature (30 °C) favored their accumulation in neutral lipids. As the main conclusion, the low thermal stability observed for the major and seed specific isoform (FAD2‐1) is the key factor controlling the direct temperature regulation in sunflower seeds.     

UHP lamps for projection

UHP lamps are now standard equipment in highly efficient projection systems. These systems are moving toward smaller displays, brighter screens, and ultra‐compactness. Consequently, a range of UHP lamps has been developed to fulfil these ever‐increasing demands. This paper describes the basic principles of UHP lamps and reviews the major achievements made over the last several years, which include reduction in arc size, arc stabilization, and ignition voltage reduction.