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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/S0002-8703(00)90321-1 Byline: Ulrich Koehler, Heinrich F. Becker, Wolfram Grimm, Jorg Heitmann, Jorg H. Peter, Harald Schafer Abstract: Background Obesity, apneic hypoxemia, and rapid eye movement (REM) sleep are supposed to be the major causes for bradyarrhythmia in patients with obstructive sleep apnea. The aims of this study were to compare clinical findings and diagnoses in patients with obstructive sleep apnea with and without nocturnal bradyarrhythmia and to analyze the relations among hypoxemia, sleep stage, and bradyarrhythmia. Methods During a 17-month period 239 patients were found to have sleep apnea in an ambulatory study. Patients with nocturnal bradyarrhythmia were hospitalized for 3 days and polysomnographies were performed over 2 successive nights. A Holter electrocardiogram was recorded for 48 hours. Results Nocturnal episodes of bradyarrhythmia were identified in 17 (7%) of 239 patients. Body mass index (39 [+ or -] 7 vs 31 [+ or -] 5 kg/m.sup.2) and respiratory disturbance index (90 [+ or -] 36 per hour vs 24 [+ or -] 24 per hour) were significantly different (P < .01) between patients with (n = 17) and without bradyarrhythmia (n = 222). Bradyarrhythmia occurred significantly more often during REM than non-REM sleep (P < .01). There was a significant difference in end-apneic oxygen saturation in apnea/hypopnea episodes with and without bradyarrhythmia (71% [+ or -] 9% vs 75% [+ or -] 10%; P < .01). A linear relation between end-apneic oxygen saturation and number of sinus arrests and heart blocks could not be found. Conclusions Patients with apnea-associated bradyarrhythmia are more overweight than patients without bradyarrhythmia. The higher respiratory disturbance index measurements found in these patients may be caused by this difference. Bradyarrhythmia occurs predominantly during REM sleep and occurred independently from decrease in oxygen saturation; a threshold value as an upper limit could not be found. (Am Heart J 2000;139:142-8.) Author Affiliation: Marburg and Bonn, Germany From the.sup.aDepartment of Internal Medicine, Philipps-University of Marburg, and the.sup.bDepartment of Internal Medicine, Rheinische Friedrich-Wilhelms University of Bonn Article History: Received 22 March 1999; Accepted 27 June 1999 Article Note: (footnote) [star] Reprint requests: Ulrich Koehler, MD, Department of Internal Medicine, Medizinische Poliklinik, Philipps-University Marburg, Baldingerstrasse, 35033 Marburg, Germany., [star][star] 0002-8703/2000/$12.00 + 0 4/1/101492

This paper presents design, fabrication and measurements for two single-axial resonant driven microscanners with apertures of 1.2 mm and 1 mm diameter, which achieve large θ opt D-products of 73.2̊ mm and 40̊ mm at high frequencies of 27 kHz and 60 kHz, respectively. Unipolar rectangular signals with different amplitudes of 15 V and 10 V have been used for driving. The attainment of large tilting angles and high frequencies are resulted from the high torque delivered by the thin-film PZT driving layer and mechanical leverage amplification. To study the influence of geometrical parameters on the static and dynamic performance and optimize the designs, FEM simulations have been applied. In order to realize closed-loop actuation one actuator has been used as piezoelectric sensor delivering corresponding feedback signals for position detection. The simulation and characterization results will be presented and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Chaetoceros calcitrans is a small, fast-growing diatom with a high nutritional value for filter feeders. It is often used in hatcheries, particularly in the production of bivalve spat. It is widely produced in batch culture systems ranging from carboys to plastic bags to high volume tanks. Continuous culture of C. calcitrans has generally not been successful due to frequent crashes of the culture. We report the continuous culture of C. calcitrans in a hanging plastic bag system that is suitable for use in commercial hatcheries. Runs of continuous production lasted up to 125d, with an average bag life of 24.4d. Crashes occurred at irregular intervals in individual bags and caused the cell concentration to drop by up to three orders of magnitude. Cultures recovered over a few days following a crash. The temporary reduction of production due to crashes in individual bags was compensated by a 30% higher production than required. At dilution rates of 1.0–1.3volume exchangesd−1 the system produced 7–13×106 cellsmL−1 d−1. The cell diameter mode as determined by a Coulter Counter was 2.8–3.0μm. The cells had the typical flat rectangular box shape with well-developed setae. The culturable bacterial population of the algae culture was 105–107 colony forming unitsmL−1. Genetic integrity of C. calcitrans and monospecific status of the continuous culture were maintained over 7 sequential bag-to-bag transfers during a 125-day run. The fatty acid profiles of continuous and batch cultures of C. calcitrans were similar. Growth and survival of Greenshell™ mussel (Perna canaliculus) larvae were identical when fed with C. calcitrans batch culture or continuous culture delivered directly from the harvest line. When continuous culture was first collected over 24h, diluted and then delivered to the rearing tanks over 24h, larval growth was markedly slower (24d to reach settlement competency compared to 21d for the other two treatments); however the subsequent settlement success of competent larvae was not statistically different between the three diets (‘Carboy’, ‘Continuous/Harvest line’, ‘Continuous/Feed-out bin’; 33.9–35.5% settled). Concomitant to the differences in larval performance we observed a difference in larval fatty acid profile: lower-performing larvae had a markedly lower proportion of mono-unsaturated fatty acids and a markedly higher proportion of poly-unsaturated fatty acids. Lower performance and different fatty acid profiles of larvae fed the ‘Continuous/Feed-out bin’ diet appeared to be caused by unidentified changes that occurred during storage of the C. calcitrans culture. [Copyright &y& Elsevier]

Abstract: Quite diverse concepts for targets have been proposed for ESS. While there is no doubt that different approaches are possible in principle, here it is argued that a large new neutron production facility, prepared for operation at an unprecedented power level, should rely as much as possible on proven technology. The neutron spallation sources SINQ and UCN at PSI feature as their standard a solid state target consisting of Zircaloy tubes filled with lead (“cannelloni”). These targets are cooled with heavy water. SINQ is currently being operated for the second decade at a power level of about 1MW. A first quick assessment of the suitability of this target type for ESS conditions gives encouraging results but a wide variety of technical questions has still to be addressed in more detail. Possible paths for optimization as well as proposals for promising configurations are sketched. [Copyright &y& Elsevier]

Abstract: Objectives: The aim was to assess in vitro the resistance to corrosion of eight commercial dental alloys by two quantitative methods, electrochemical and immersion tests, then to statistically test the hypothesis of possible correlation between the polarization resistance (R p) and the elemental release. Methods: Two quantitative methods; electrochemical and immersion test, were used. From the first, after recording the OCP during 24h immersion in acidified artificial saliva (pH 2.3), R p was obtained using the linear polarization in anodic path and applying the Mansfeld''s method. From the static immersion test, using the same test solution, the elemental release from was analysed and determined using the ICP-AES. Thereafter, the two measurements were used to plot the regression line and to determine the correlation coefficient. The significance of the correlation was tested using F-test at a confidence interval of 0.99. Results: : The resistance to corrosion results obtained from the two methods were ranked and compared; an inverse relation between them was evident. Then, the obtained coefficient of correlation (R 2) was 0.886. With the F-test at 0.99 confidence interval, the hypothesis was accepted as the calculated F was about 44 against critical F =13.7. Conclusion: The correlation between the two measurements, R p and mass loss, was proved statistically significant. This result may provide a new approach to predict the corrosion behaviour of dental alloys by firstly using the easier methods. [Copyright &y& Elsevier]

We designed new primers that give shorter amplicons for Penta D and Penta E for easy separation on native polyacrylamide gels. 112 unrelated Northern Thai men were typed. A total of nine and eight-teen alleles was found for Penta D and Penta E, respectively. Both loci showed a high power of discrimination (Penta D: 0.927; Penta E: 0.966; both loci combined: 0.9975) as reported in other populations. Penta D met Hardy-Weinberg expectations, whereas Penta E did not, maybe because of the small sample size in relation to the large number of alleles of this locus. [Copyright &y& Elsevier]

BACKGROUND: Two German sisters aged 14 and 17 y were admitted to the Tubingen eye hospital with a history of night blindness. In both siblings, plasma retinol binding protein (RBP) concentrations were below the limit of detection (<0.6 micromol/L) and plasma retinol concentrations were extremely low (0.19 micromol/L). Interestingly, intestinal absorption of retinyl esters was normal. In addition, other factors associated with low retinol concentrations (eg, low plasma transthyretin or zinc concentrations or mutations in the transthyretin gene) were not present. Neither sibling had a history of systemic disease. OBJECTIVE: Our aim was to investigate the cause of the retinol deficiency in these 2 siblings. DESIGN: The 2 siblings and their mother were examined clinically, including administration of the relative-dose-response test, DNA sequencing of the RBP gene, and routine laboratory testing. RESULTS: Genomic DNA sequence analysis revealed 2 point mutations in the RBP gene: a T-to-A substitution at nucleotide 1282 of exon 3 and a G-to-A substitution at nucleotide 1549 of exon 4. These mutations resulted in amino acid substitutions of asparagine for isoleucine at position 41 (Ile41-->Asn) and of aspartate for glycine at position 74 (Gly74-->Asp). Sequence analysis of cloned polymerase chain reaction products spanning exons 3 and 4 showed that these mutations were localized on different alleles. The genetic defect induced severe biochemical vitamin A deficiency but only mild clinical symptoms (night blindness and a modest retinal dystrophy without effects on growth). CONCLUSIONS: We conclude that the cellular supply of vitamin A to target tissues might be bypassed in these siblings via circulating retinyl esters, beta-carotene, or retinoic acid, thereby maintaining the health of peripheral tissues. Copyright (c) 1999 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]