Heating rate and electrode charging measurements in a scalable, microfabricated, surface-electrode ion trap

We characterise the performance of a surface-electrode ion "chip" trap fabricated using established semiconductor integrated circuit and micro-electro-mechanical-system (MEMS) microfabrication processes which are in principle scalable to much larger ion trap arrays, as proposed for implementing ion trap quantum information processing. We measure rf ion micromotion parallel and perpendicular to the plane of the trap electrodes, and find that on-package capacitors reduce this to <~ 10 nm in amplitude. We also measure ion trapping lifetime, charging effects due to laser light incident on the trap electrodes, and the heating rate for a single trapped ion. The performance of this trap is found to be comparable with others of the same size scale.Comment: 6 pages, 10 figure

G-protein signaling: back to the future

Heterotrimeric G-proteins are intracellular partners of G-protein-coupled receptors (GPCRs). GPCRs act on inactive Gα·GDP/Gβγ heterotrimers to promote GDP release and GTP binding, resulting in liberation of Gα from Gβγ. Gα·GTP and Gβγ target effectors including adenylyl cyclases, phospholipases and ion channels. Signaling is terminated by intrinsic GTPase activity of Gα and heterotrimer reformation — a cycle accelerated by ‘regulators of G-protein signaling’ (RGS proteins). Recent studies have identified several unconventional G-protein signaling pathways that diverge from this standard model. Whereas phospholipase C (PLC) β is activated by Gαq and Gβγ, novel PLC isoforms are regulated by both heterotrimeric and Ras-superfamily G-proteins. An Arabidopsis protein has been discovered containing both GPCR and RGS domains within the same protein. Most surprisingly, a receptor-independent Gα nucleotide cycle that regulates cell division has been delineated in both Caenorhabditis elegans and Drosophila melanogaster. Here, we revisit classical heterotrimeric G-protein signaling and explore these new, non-canonical G-protein signaling pathways

Analysis of the DC-arc behavior of a novel 3D-active fuse

In this work, the DC-arc behavior of an active fuse integrated into a CMOS process is described. The purpose of this fuse is to prevent serious hazards in power electronics in the case of a malfunction of a single power-transistor. The focus of this work is on the characterization of functionality and reliability of the "cutout-bridge". Different cutout-bridge geometries and the DC-arc behavior during fuse release are analyzed. It is shown that a significant increase in release time occurs, when a DC-arc across the cutout-bridge is ignited at voltages above 20V. By integrating a snubber device into the circuit, the DC-arc behavior will be clearly reduced and the release time of the fuse will be decreased significantly

Circulating and tissue expression levels of YKL-40 in renal cell cancer

PURPOSE: Blood levels of YKL-40 are elevated in various malignancies and other inflammatory diseases. Moreover, higher YKL-40 levels, have consequently been shown to correlate with poor prognosis in several cancers. The aim of this study was to investigate the prognostic value of circulating and tissue levels of YKL-40 in renal cell cancer (RCC). PATIENTS AND METHODS: Preoperative YKL-40 serum/plasma levels were determined in 222 surgically treated RCC patients, as well as in 35 controls. Postoperative serum samples were analysed in 19 of the 222 RCC cases. Moreover, gene expression levels were assessed in 101 RCC frozen tissue samples using quantitative RT real-time PCR. Finally, immunohistochemical analysis was done in 37 RCC cases to assess the tissue localization of YKL-40. Results were correlated with clinicopathological and follow-up data. RESULTS: YKL-40 serum but not tissue gene expression levels were higher in RCC patients compared to controls (p= 0.050). Serum YKL-40 levels significantly increased following nephrectomy (p< 0.001). High circulating YKL-40 concentrations were independently associated with shorter survival in both serum and plasma cohorts. YKL-40 gene expression was not correlated with patients' prognosis. CONCLUSIONS: Preoperative elevated circulating levels of YKL-40 predict survival in patients treated with nephrectomy for RCC independently of determining from serum or plasma. Tumour cells do not seem to be the main source of elevated serum/plasma YKL-40 levels in RCC patients

Inactivation of ceramide synthase 6 in mice results in an altered sphingolipid metabolism and behavioral abnormalities

The N-acyl chain length of ceramides is determined by the specificity of different ceramide synthases (CerS). The CerS family in mammals consists of six members with different substrate specificities and expression patterns. We have generated and characterized a mouse line harboring an enzymatically inactive ceramide synthase 6 (CerS6KO) gene and lacz reporter cDNA coding for beta-galactosidase directed by the CerS6 promoter. These mice display a decrease in C16:0 containing sphingolipids. Relative to wild type tissues the amount of C16:0 containing sphingomyelin in kidney is approximately 35%, whereas we find a reduction of C16:0 ceramide content in the small intestine to about 25%. The CerS6KO mice show behavioral abnormalities including a clasping abnormality of their hind limbs and a habituation deficit. LacZ reporter expression in the brain reveals CerS6 expression in hippocampus, cortex, and the Purkinje cell layer of the cerebellum. Using newly developed antibodies that specifically recognize the CerS6 protein we show that the endogenous CerS6 protein is N-glycosylated and expressed in several tissues of mice, mainly kidney, small and large intestine, and brain