Magnetic phase control by an electric field

The quest for higher data density in information storage is motivating investigations into approaches for manipulating magnetization by means other than magnetic fields. This is evidenced by the recent boom in magnetoelectronics and 'spintronics', where phenomena such as carrier effects in magnetic semiconductors and high-correlation effects in colossal magnetoresistive compounds are studied for their device potential. The linear magnetoelectric effect-the induction of polarization by a magnetic field and of magnetization by an electric field-provides another route for linking magnetic and electric properties. It was recently discovered that composite materials and magnetic ferroelectrics exhibit magnetoelectric effects that exceed previously known effects by orders of magnitude, with the potential to trigger magnetic or electric phase transitions. Here we report a system whose magnetic phase can be controlled by an external electric field: ferromagnetic ordering in hexagonal HoMnO3 is reversibly switched on and off by the applied field via magnetoelectric interactions. We monitor this process using magneto-optical techniques and reveal its microscopic origin by neutron and X-ray diffraction. From our results, we identify basic requirements for other candidate materials to exhibit magnetoelectric phase control.     

Magnetic exchange force microscopy with atomic resolution

The ordering of neighbouring atomic magnetic moments (spins) leads to important collective phenomena such as ferromagnetism and antiferromagnetism. A full understanding of magnetism on the nanometre scale therefore calls for information on the arrangement of spins in real space and with atomic resolution. Spin-polarized scanning tunnelling microscopy accomplishes this but can probe only conducting materials. Force microscopy can be used on any sample independent of its conductivity. In particular, magnetic force microscopy is well suited to exploring ferromagnetic domain structures. However, atomic resolution cannot be achieved because data acquisition involves the sensing of long-range magnetostatic forces between tip and sample. Magnetic exchange force microscopy has been proposed for overcoming this limitation: by using an atomic force microscope with a magnetic tip, it should be possible to detect the short-range magnetic exchange force between tip and sample spins. Here we show for a prototypical antiferromagnetic insulator, the (001) surface of nickel oxide, that magnetic exchange force microscopy can indeed reveal the arrangement of both surface atoms and their spins simultaneously. In contrast with previous attempts to implement this method, we use an external magnetic field to align the magnetic polarization at the tip apex so as to optimize the interaction between tip and sample spins. This allows us to observe the direct magnetic exchange coupling between the spins of the tip atom and sample atom that are closest to each other, and thereby demonstrate the potential of magnetic exchange force microscopy for investigations of inter-spin interactions at the atomic level.     

Laserprobe oxygen isotope analysis of minerals from mantle-derived rocks in eastern China

Oxygen isotope analyses were carried out by the laserprobe technique for mineral separates from mantle xenolith and megacryst in Cenozoic basalts, East China. The results not only give the δ I8O range consistent with that reported for peridotites in the world, but also yield oxygen isotope equilibrium between coexisting minerals.     

Protein levels of clusterin and glutathione synthetase in platelets allow for early detection of colorectal cancer

Colorectal cancer (CRC) is one of the most frequent malignancies in the Western world. Early tumor detection and intervention are important determinants on CRC patient survival. During early tumor proliferation, dissemination and angiogenesis, platelets store and segregate proteins actively and selectively. Hence, the platelet proteome is a potential source of biomarkers denoting early malignancy. By comparing protein profiles of platelets between healthy volunteers (n = 12) and patients with early- (n = 7) and late-stage (n = 5) CRCs using multiplex fluorescence two-dimensional gel electrophoresis (2D-DIGE), we aimed at identifying differentially regulated proteins within platelets. By inter-group comparisons, 94 differentially expressed protein spots were detected (p < 0.05) between healthy controls and patients with early- and late-stage CRCs and revealed distinct separations between all three groups in principal component analyses. 54 proteins of interest were identified by mass spectrometry and resulted in high-ranked Ingenuity Pathway Analysis networks associated with Cellular function and maintenance, Cellular assembly and organization, Developmental disorder and Organismal injury and abnormalities (p < 0.0001 to p = 0.0495). Target proteins were validated by multiplex fluorescence-based Western blot analyses using an additional, independent cohort of platelet protein samples [healthy controls (n = 15), early-stage CRCs (n = 15), late-stage CRCs (n = 15)]. Two proteins—clusterin and glutathione synthetase (GSH-S)—featured high impact and were subsequently validated in this independent clinical cohort distinguishing healthy controls from patients with early- and late-stage CRCs. Thus, the potential of clusterin and GSH-S as platelet biomarkers for early detection of CRC could improve existing screening modalities in clinical application and should be confirmed in a prospective multicenter trial.     

A genome-wide association study of metabolic traits in human urine

We present a genome-wide association study of metabolic traits in human urine, designed to investigate the detoxification capacity of the human body. Using NMR spectroscopy, we tested for associations between 59 metabolites in urine from 862 male participants in the population-based SHIP study. We replicated the results using 1,039 additional samples of the same study, including a 5-year follow-up, and 992 samples from the independent KORA study. We report five loci with joint P values of association from 3.2 × 10(-19) to 2.1 × 10(-182). Variants at three of these loci have previously been linked with important clinical outcomes: SLC7A9 is a risk locus for chronic kidney disease, NAT2 for coronary artery disease and genotype-dependent response to drug toxicity, and SLC6A20 for iminoglycinuria. Moreover, we identify rs37369 in AGXT2 as the genetic basis of hyper-β-aminoisobutyric aciduria.     

CCN1: a novel inflammation-regulated biphasic immune cell migration modulator

In this study, we performed a comprehensive analysis of the effect of CCN1 on the migration of human immune cells. The molecule CCN1, produced by fibroblasts and endothelial cells, is considered as an important matrix protein promoting tissue repair and immune cell adhesion by binding various integrins. We recently reported that CCN1 therapy is able to suppress acute inflammation in vivo. Here, we show that CCN1 binds to various immune cells including T cells, B cells, NK cells, and monocytes. The addition of CCN1 in vitro enhances both actin polymerization and transwell migration. Prolonged incubation with CCN1, however, results in the inhibition of migration of immune cells by a mechanism that involves downregulation of PI3Kγ, p38, and Akt activation. Furthermore, we observed that immune cells themselves produce constitutively CCN1 and secretion is induced by pro-inflammatory stimuli. In line with this finding, patients suffering from acute inflammation had enhanced serum levels of CCN1. These findings extend the classical concept of CCN1 as a locally produced cell matrix adhesion molecule and suggest that CCN1 plays an important role in regulating immune cell trafficking by attracting and locally immobilizing immune cells.     

Impaired glycosylation and cutis laxa caused by mutations in the vesicular H+-ATPase subunit ATP6V0A2

We identified loss-of-function mutations in ATP6V0A2, encoding the a2 subunit of the V-type H+ ATPase, in several families with autosomal recessive cutis laxa type II or wrinkly skin syndrome. The mutations result in abnormal glycosylation of serum proteins (CDG-II) and cause an impairment of Golgi trafficking in fibroblasts from affected individuals. These results indicate that the a2 subunit of the proton pump has an important role in Golgi function.     

BIM-Based Indoor-Emergency-Navigation-System for Complex Buildings

The imminence of terrorist activities and the necessity of the maximum possible disaster preparedness in the sense of indoor-navigation support have been brought to evidence by several catastrophes, e.g., the fire at Istanbul Airport in May 2006 or the terror attacks on the London Underground on July 7, 2005. Since 2001 ten terror attacks have been thwarted only in Great Britain. For that reason the aim of the presented research project is to develop a solution for response and recovery to support rescuers in finding the shortest way within a public building and provide them with important information in their particular spa-tial context. Existing building information models (BIM) are used for displaying plans on mobile devices and for routing purposes. The indoor navigation system is based on wireless LAN (WLAN), ultra-wide-band (UWB), and radio frequency identification (RFID). These technologies are described in detail and an overview on data formats which are used to retrieve building data out of the BIM for generating routing networks is given.     

HDAC2 and TXNL1 distinguish aneuploid from diploid colorectal cancers

DNA aneuploidy has been identified as a prognostic factor for epithelial malignancies. Further understanding of the translation of DNA aneuploidy into protein expression will help to define novel biomarkers to improve therapies and prognosis. DNA ploidy was assessed by image cytometry. Comparison of gel-electrophoresis-based protein expression patterns of three diploid and four aneuploid colorectal cancer cell lines detected 64 ploidy-associated proteins. Proteins were identified by mass spectrometry and subjected to Ingenuity Pathway Analysis resulting in two overlapping high-ranked networks maintaining Cellular Assembly and Organization, Cell Cycle, and Cellular Growth and Proliferation. CAPZA1, TXNL1, and HDAC2 were significantly validated by Western blotting in cell lines and the latter two showed expression differences also in clinical samples using a tissue microarray of normal mucosa (n?=?19), diploid (n?=?31), and aneuploid (n?=?47) carcinomas. The results suggest that distinct protein expression patterns, affecting TXNL1 and HDAC2, distinguish aneuploid with poor prognosis from diploid colorectal cancers.