17 research outputs found

    Untersuchungen über Tanaidaceen, 1 : Bemerkungen über die postmarsupiale Entwicklung der Tanaidaceen

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    In dieser Arbeit wird wahrscheinlich gemacht, daß der Modus der postmarsupialen Entwicklung von Heterotanais oerstedi (KRÖYER), wie ihn BÜCKLE-RAMIREZ beschrieben hat, für alle Tanaidaccen zutrifft. In this work the statement is made that the postmarsupial development of Heterotanais oerstedi (KRÖYER) found by BÜCKLE-RAMIREZ holds true for all species of Tanaidacea

    Flexible 23-channel coil array for high-resolution magnetic resonance imaging at 3 Tesla.

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    PURPOSE:The purpose of this work is the design, implementation and evaluation of a mechanically flexible receive-only coil array for magnetic resonance imaging (MRI) at 3 T that can be applied to various target organs and provides high parallel imaging performance. METHODS:A 23-channel array was designed based on a rigid-flex printed circuit board (PCB). The flexible multi-layer part contains the copper traces forming the coil elements. The rigid part of the PCB houses the solder joints and lumped elements. The coil housing consists of rigid caps mounted above the rigid parts. Adhesive PTFE sheets cover all flexible parts. The developed array was tested on the bench as well as in phantom and in vivo MRI experiments employing parallel imaging acceleration factors up to six. RESULTS:Efficient mutual decoupling between receive elements and detuning between receive array and body coil was achieved. An increased signal-to-noise ratio in comparison to commercial reference coils is demonstrated, especially in regions close to the developed array and for high parallel imaging acceleration factors. Exemplary in vivo images of head, ankle, knee, shoulder and hand are presented. CONCLUSION:Based on high sensitivity close to the array and low g-factors, this flexible coil is well suited for studies of occipital and temporal cortex, as well as musculoskeletal targets like knee, ankle, elbow and wrist

    Proton-decoupled carbon magnetic resonance spectroscopy in human calf muscles at 7 T using a multi-channel radiofrequency coil

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    13C magnetic resonance spectroscopy is a viable, non-invasive method to study cell metabolism in skeletal muscles. However, MR sensitivity of 13C is inherently low, which can be overcome by applying a higher static magnetic field strength together with radiofrequency coil arrays instead of single loop coils or large volume coils, and 1H decoupling, which leads to a simplified spectral pattern. 1H-decoupled 13C-MRS requires RF coils which support both, 1H and 13C, Larmor frequencies with sufficient electromagnetic isolation between the pathways of the two frequencies. We present the development, evaluation, and first in vivo measurement with a 7 T 3-channel 13C and 4-channel 1H transceiver array optimized for 1H-decoupled 13C-MRS in the posterior human calf muscles. To ensure minimal cross-coupling between 13C and 1H arrays, several strategies were combined: mutual magnetic flux was minimized by coil geometry, two LCC traps were inserted into each 13C element, and band-pass and low-pass filters were integrated along the signal pathways. The developed coil array was successfully tested in phantom and in vivo MR experiments, showing a simplified spectral pattern and increase in signal-to-noise ratio of approximately a factor 2 between non-decoupled and 1H-decoupled spectra in a glucose phantom and the human calf muscle.(VLID)464140

    Cabbage Cryoprotectin Is a Member of the Nonspecific Plant Lipid Transfer Protein Gene Family

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    We have recently purified a protein (cryoprotectin) from the leaves of cold-acclimated cabbage (Brassica oleracea) to electrophoretic homogeneity, which protects thylakoids isolated from the leaves of nonacclimated spinach (Spinacia oleracea) from freeze-thaw damage. Sequencing of cryoprotectin showed the presence of at least three isoforms of WAX9 proteins, which belong to the class of nonspecific lipid transfer proteins. Antibodies raised against two synthetic peptides derived from the WAX9 proteins recognized a band of approximately 10 kD in western blots of crude cryoprotectin preparations. This protein and the cryoprotective activity could be precipitated from solution by the antiserum. We show further that cryoprotectin is structurally and functionally different from WAX9 isolated from the surface wax of cabbage leaves. WAX9 has lipid transfer activity for phosphatidylcholine, but no cryoprotective activity. Cryoprotectin, on the other hand, has cryoprotective, but no lipid transfer activity. The cryoprotective activity of cryoprotectin was strictly dependent on Ca(2+) and Mn(2+) and could be inhibited by chelating agents, whereas the lipid transfer activity of WAX9 was higher in the presence of ethylenediaminetetraacetate than in the presence of Ca(2+) and Mn(2+)

    A flexible 12-channel transceiver array of transmission line resonators for 7 T MRI.

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    International audienceA flexible transceiver array based on transmission line resonators (TLRs) combining the advantages of coil arrays with the possibility of form-fitting targeting cardiac MRI at 7 T is presented. The design contains 12 elements which are fabricated on a flexible substrate with rigid PCBs attached on the center of each element to place the interface components, i.e. transmit/receive (T/R) switch, power splitter, pre-amplifier and capacitive tuning/matching circuitry. The mutual coupling between elements is cancelled using a decoupling ring-based technique. The performance of the developed array is evaluated by 3D electromagnetic simulations, bench tests, and MR measurements using phantoms. Efficient inter-element decoupling is demonstrated in flat configuration on a box-shaped phantom (Sij < -19 dB), and bent on a human torso phantom (Sij < -16 dB). Acceleration factors up to 3 can be employed in bent configuration with reasonable g-factors (<1.7) in an ROI at the position of the heart. The array enables geometrical conformity to bodies within a large range of size and shape and is compatible with parallel imaging and parallel transmission techniques

    Specific differences in migratory function of myofibroblasts isolated from Crohn's disease fistulae and strictures

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    BACKGROUND: Recently we found that migration of colonic lamina propria fibroblasts in Crohn's disease patients (CD-CLPF) from inflamed mucosa is significantly reduced as compared to control-CLPF. The behavior of CD-CLPFs isolated from fistulae and strictures was now investigated in detail. METHODS: Initially migration assays for all CLPF cultures (CD-CLPF, fibrosis-CLPF, and fistula-CLPF) were performed in the modified 48-well Boyden chamber. Subsequently, for a migration assay more resembling the in vivo situation a 3D matrix model was developed. After seeding of cells into the 3D matrix the CLPF layer was wounded by an ERBIUM:YAG laser leading to circular cell rupture without effect on the extracellular matrix. RESULTS: In the modified Boyden chamber migration of fistula-CLPF was significantly reduced compared to CD-CLPF. This was correlated with a decrease in FAK-protein expression, whereas in migrating fibrosis-CLPF an increase in FAK-protein expression, -autophosphorylation and migratory potential was found. This was confirmed in the 3D matrix wounding assay: Fistula-CLPF migrated less than CD-CLPF, whereas fibrosis-CLPF migrated significantly more in the 3D matrix wounding assay. Between 1 to 36 hours incubation time fibrosis-CLPF always displayed increased migration ability as compared to CD-CLPF. In contrast, fistula-CLPF migratory potential was always below that of CD-CLPF. CONCLUSIONS: Myofibroblasts isolated from inflamed, fibrostenotic, or fistulized CD mucosa differ in their migratory potential both in the modified Boyden chamber as well as in a 3D matrix model. These different migratory behaviors could be an explanation for impaired or excess wound healing and subsequently for fistula and fibrosis formation

    Streiks und die Zuverlässigkeit der Verkehrsbedienung

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    Mit der Privatisierung und der Aufhebung des Prinzips der Tarifeinheit haben die Arbeitskämpfe im Verkehrswesen stark zugenommen. Die Zuverlässigkeit der Verkehrsbedienung ist gefährdet und unbeteiligte Dritte haben oft das Nachsehen. Der Wissenschaftliche Beirat beim Bundesminister für Verkehr und digitale Infrastruktur hat eine Stellungnahme vorgelegt, die Empfehlungen ausspricht, wie das Streikrecht im Verkehrswesen neu geregelt werden kann.Of late, Germany has been hit by unprecedented strike actions by airline and railway staff. Lufthansa's pilots staged 13 walkouts between April 2014 and September 2015, resulting in the cancellation of 8,500 flights and affecting around one million passengers. The one week strike by Lufthansa's cabin crews in November 2015 forced the company to cancel another 4,700 flights. The trend towards industrial action in the German transportation sector is not limited to airline pilots and cabin crew, however. In addition, security agents and ground staff at several airports have gone on strike, and most of all, train drivers walk out with increasing frequency. In this article, measures are proposed to balance the legal, and legitimate, right of workers to use strikes as a tool of last resort in wagebargaining processes with the no less important right of customers to have access to reliable transportation services. While many other Western countries have regulations in place for the conduct of wage bargaining, including rules on work stoppages in core public service sectors, no such rules exist in Germany
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