Flow profiling of a surface acoustic wave nanopump

The flow profile in a capillary gap and the pumping efficiency of an acoustic micropump employing Surface Acoustic Waves is investigated both experimentally and theoretically. Such ultrasonic surface waves on a piezoelectric substrate strongly couple to a thin liquid layer and generate an internal streaming within the fluid. Such acoustic streaming can be used for controlled agitation during, e.g., microarray hybridization. We use fluorescence correlation spectroscopy and fluorescence microscopy as complementary tools to investigate the resulting flow profile. The velocity was found to depend on the applied power somewhat weaker than linearly and to decrease fast with the distance from the ultrasound generator on the chip.Comment: 12 pages 20 figure

Long-term tillage, straw, and N rate effects on quantity and quality of organic C and N in a Black Chernozemic soil

Non-Peer Reviewe

Long-term tillage, straw, and N rate effects on quantity and quality of organic C and N in a Gray Luvisol soil

Non-Peer Reviewe

Influence of long-term application of N and S fertilizers (1980-2002) and liming in 1992 on dry matter yield of grass and soil properties in a Dark Gray Chernozem in north-central Saskatchewan

Non-Peer ReviewedMost soils are deficient in plant-available N in the Prairie Provinces of Canada, and in the Parkland region, many soils are also insufficient in available S for high crop yields. Long-term field experiments, initiated in 1980 and 1996 on a Dark Gray Chernozem loam soil at Canwood in north-central Saskatchewan, were conducted to determine the effects of N, S and lime application and forage removal on forage dry matter yield (DMY) and soil properties. The results indicated that application of N or S alone had only a little effect on DMY, while application of N together with S substantially increased DMY. Decline of soil pH by annual applications of N and S fertilizers mainly happened in the 0-5 cm layer. In layers below 10 cm, soil pH tended to increase with N or NS fertilization. Surface application of granular lime increased soil pH mainly in the 0-5 cm layer, and the high pH was maintained for at least 9 years. The TOC and TN mass in the 0-7.5 cm soil layer increased with annual applications of N and S fertilizers, and the increase was more pronounced with application of N and S together. In the subsoil layers, the N treatment tended to decrease, but the NS treatment tended to increase the TOC and TN. This suggests that application of N and S together was more effective in increasing C and N sequestration in a soil deficient in both N and S

Sortilin, SorCS1b, and SorLA Vps10p sorting receptors, are novel γ-secretase substrates

BACKGROUND: The mammalian Vps10p sorting receptor family is a group of 5 type I membrane homologs (Sortilin, SorLA, and SorCS1-3). These receptors bind various cargo proteins via their luminal Vps10p domains and have been shown to mediate a variety of intracellular sorting and trafficking functions. These proteins are highly expressed in the brain. SorLA has been shown to be down regulated in Alzheimer's disease brains, interact with ApoE, and modulate Aβ production. Sortilin has been shown to be part of proNGF mediated death signaling that results from a complex of Sortilin, p75(NTR )and proNGF. We have investigated and provide evidence for γ-secretase cleavage of this family of proteins. RESULTS: We provide evidence that these receptors are substrates for presenilin dependent γ-secretase cleavage. γ-Secretase cleavage of these sorting receptors is inhibited by γ-secretase inhibitors and does not occur in PS1/PS2 knockout cells. Like most γ-secretase substrates, we find that ectodomain shedding precedes γ-secretase cleavage. The ectodomain cleavage is inhibited by a metalloprotease inhibitor and activated by PMA suggesting that it is mediated by an α-secretase like cleavage. CONCLUSION: These data indicate that the α- and γ-secretase cleavages of the mammalian Vps10p sorting receptors occur in a fashion analogous to other known γ-secretase substrates, and could possibly regulate the biological functions of these proteins

Model-based design of AM components to enable decentralized digital manufacturing systems

Additive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy

Crystallisation and preliminary X-ray analysis of the receptor-binding domain of human and bovine α2-macroglobulin

AbstractThe receptor-binding domains (RBDs) of human and bovine α2-macroglobulin (α2M) have been isolated after limited proteolysis of methylamine-treated α2M with papain. Single crystals of the RBDs have been grown by vapour diffusion. Crystals of human RBD are very thin plates unsuited for data collection. However, crystals of RBD from bovine α2M give diffraction patterns suitable for X-ray analysis, and a complete dataset with a maximum resolution of 2.3 Å has been collected with synchrotron radiation at cryogenic temperature. The crystals belong to spacegroup P3121 or P3221 with cell parameters a = b = 106.8 Å, c = 72.2 Å