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1.
Intensive fertilizer use has led to nitrate contamination of groundwater in many areas. This article examines the possibility of removing nitrates through the construction of artificial wetlands. A pilot study conducted in Denmark has found that the method is effective and economical, at least for small waterworks, though further treatment is necessary before an acceptable microbiological water quality is attained. 相似文献
2.
Wan-Yu Wu Jyh-Ming Ting Hayo Zutz Dominika Lyzwa Inga Gerhards Carsten Ronning Hans Hofsäss 《Diamond and Related Materials》2008,17(7-10):1494-1497
While experimenting with the growth of metal-containing amorphous carbon (a-c:Me) thin films using two different growth processes, self-assembled multilayered structures were observed. One of the processes is a reactive magnetron sputter deposition process. The other process is a mass selective ion beam deposition process. Despite of the differences in the growth method and the growth condition, self-assembled multilayered thin films, consisting of alternating dark layer and bright layer, were obtained in both processes. Based on the consideration of energy for atomic diffusion in the thin films, the growth mechanism is discussed. 相似文献
3.
4.
Tholén EA Platz D Forchheimer D Schuler V Tholén MO Hutter C Haviland DB 《The Review of scientific instruments》2011,82(2):026109
Nonlinear systems can be probed by driving them with two or more pure tones while measuring the intermodulation products of the drive tones in the response. We describe a digital lockin analyzer which is designed explicitly for this purpose. The analyzer is implemented on a field-programmable gate array, providing speed in analysis, real-time feedback, and stability in operation. The use of the analyzer is demonstrated for intermodulation atomic force microscopy. A generalization of the intermodulation spectral technique to arbitrary drive waveforms is discussed. 相似文献
5.
Carsten Behn 《Multibody System Dynamics》2011,26(3):213-243
In this paper we consider an adaptive control problem of finite DoF worm-like locomotion systems (WLLS) which contact the
ground with Coulomb dry friction. Using a rough mathematical friction law the system is shown to belong to a system class
that allows adaptive control. Gaits from the kinematic theory can be tracked by means of adaptive controllers. For this we
introduce two different adaptive controllers for λ-tracking and focus on that one which is not based on the derivative of the output. We pay attention to the analysis of such
systems and present some theoretical control investigations including proofs. Numerical simulations of tracking different
reference signals under arbitrary choice of the system parameters demonstrate and illustrate that the introduced simple adaptive
controllers work successfully and effectively. Current experiments are aimed at the justification of theoretical results. 相似文献
6.
Sebastian Kummer Susanne Rinn Gunnar Seemann Nadine Bachmann Katherine Timothy Paul S. Thornton Frank Pillekamp Ertan Mayatepek Carsten Bergmann Thomas Meissner Niels Decher 《International journal of molecular sciences》2022,23(15)
The voltage-dependent L-type calcium channel isoform CaV1.2 is critically involved in many physiological processes, e.g., in cardiac action potential formation, electromechanical coupling and regulation of insulin secretion by beta cells. Gain-of-function mutations in the calcium voltage-gated channel subunit alpha 1 C (CACNA1C) gene, encoding the CaV1.2 α1-subunit, cause Timothy syndrome (TS), a multisystemic disorder that includes autism spectrum disorders and long QT (LQT) syndrome. Strikingly, TS patients frequently suffer from hypoglycemia of yet unproven origin. Using next-generation sequencing, we identified a novel heterozygous CACNA1C mutation in a patient with congenital hyperinsulinism (CHI) and associated hypoglycemic episodes. We characterized the electrophysiological phenotype of the mutated channel using voltage-clamp recordings and in silico action potential modeling experiments. The identified CaV1.2L566P mutation causes a mixed electrophysiological phenotype of gain- and loss-of-function effects. In silico action potential modeling supports that this mixed electrophysiological phenotype leads to a tissue-specific impact on beta cells compared to cardiomyocytes. Thus, CACNA1C variants may be associated with non-syndromic hyperinsulinemic hypoglycemia without long-QT syndrome, explained by very specific electrophysiological properties of the mutated channel. We discuss different biochemical characteristics and clinical impacts of hypoglycemia in the context of CACNA1C variants and show that these may be associated with significant morbidity for Timothy Syndrome patients. Our findings underline that the potential of hypoglycemia warrants careful attention in patients with CACNA1C variants, and such variants should be included in the differential diagnosis of non-syndromic congenital hyperinsulinism. 相似文献
7.
Jonas Feldheim Almuth F. Kessler Julia J. Feldheim Ellina Schulz David Wend Lazaros Lazaridis Christoph Kleinschnitz Martin Glas Ralf-Ingo Ernestus Sebastian Brandner Camelia M. Monoranu Mario Lhr Carsten Hagemann 《International journal of molecular sciences》2022,23(9)
Glioblastoma leads to a fatal course within two years in more than two thirds of patients. An essential cornerstone of therapy is chemotherapy with temozolomide (TMZ). The effect of TMZ is counteracted by the cellular repair enzyme O6-methylguanine-DNA methyltransferase (MGMT). The MGMT promoter methylation, the main regulator of MGMT expression, can change from primary tumor to recurrence, and TMZ may play a significant role in this process. To identify the potential mechanisms involved, three primary stem-like cell lines (one astrocytoma with the mutation of the isocitrate dehydrogenase (IDH), CNS WHO grade 4 (HGA)), and two glioblastoma (IDH-wildtype, CNS WHO grade 4) were treated with TMZ. The MGMT promoter methylation, migration, proliferation, and TMZ-response of the tumor cells were examined at different time points. The strong effects of TMZ treatment on the MGMT methylated cells were observed. Furthermore, TMZ led to a loss of the MGMT promoter hypermethylation and induced migratory rather than proliferative behavior. Cells with the unmethylated MGMT promoter showed more aggressive behavior after treatment, while HGA cells reacted heterogenously. Our study provides further evidence to consider the potential adverse effects of TMZ chemotherapy and a rationale for investigating potential relationships between TMZ treatment and change in the MGMT promoter methylation during relapse. 相似文献
8.
Bernhard Deufel Carsten Mueller Gavan Duffy Tom Kevenaar 《Datenschutz und Datensicherheit - DuD》2013,37(6):363-366
While developing the specifications for electronically enabled Machine Readable Travel Documents, the ICAO paid significant attention to security aspects related to the digital information stored in this type of electronic document. This has resulted in Passive and Active Authentication, Basic Access Control and Extended Access Control. The goal of Basic Access Control (BAC) is preventing unauthorized access to the chip data stored on eMRTDs. The PACE protocol has been developed as a future-proof method to overcome the limitations of BAC and to replace BAC in the future. In this paper the BioPACE protocol is proposed as a supplement to the PACE protocol. Besides verifying if the document holder is indeed the rightful owner, the BioPACE protocol provides a higher convenience for the bearer of the document. 相似文献
9.
Koen Decroos Marc Seefeldt Carsten Ohms Roumen Petrov Frederik Verhaeghe Leo Kestens 《国际钢铁研究》2011,82(8):911-917
The relation between texture and microstructure and the macroscopic solidification direction has been investigated for an austenitic 316L stainless steel weld. The fusion zone has been characterised by EBSD. Texture development has been simulated by thermal Finite Element Analysis coupled with a simple model of preferential <100>‐oriented solidification following the solidification direction. The thermal part is validated by means of thermocouple measurements at several locations on the specimen. The predicted texture is in very good agreement with the measured one. 相似文献
10.
A multiparameter wearable physiologic monitoring system for space and terrestrial applications. 总被引:4,自引:0,他引:4
Carsten W Mundt Kevin N Montgomery Usen E Udoh Valerie N Barker Guillaume C Thonier Arnaud M Tellier Robert D Ricks Robert B Darling Yvonne D Cagle Nathalie A Cabrol Stephen J Ruoss Judith L Swain John W Hines Gregory T A Kovacs 《IEEE transactions on information technology in biomedicine》2005,9(3):382-391
A novel, unobtrusive and wearable, multiparameter ambulatory physiologic monitoring system for space and terrestrial applications, termed LifeGuard, is presented. The core element is a wearable monitor, the crew physiologic observation device (CPOD), that provides the capability to continuously record two standard electrocardiogram leads, respiration rate via impedance plethysmography, heart rate, hemoglobin oxygen saturation, ambient or body temperature, three axes of acceleration, and blood pressure. These parameters can be digitally recorded with high fidelity over a 9-h period with precise time stamps and user-defined event markers. Data can be continuously streamed to a base station using a built-in Bluetooth RF link or stored in 32 MB of on-board flash memory and downloaded to a personal computer using a serial port. The device is powered by two AAA batteries. The design, laboratory, and field testing of the wearable monitors are described. 相似文献