1,074 research outputs found
Magnetic domain walls in constrained geometries
Magnetic domain walls have been studied in micrometer-sized Fe20Ni80 elements
containing geometrical constrictions by spin-polarized scanning electron
microscopy and numerical simulations. By controlling the constriction
dimensions, the wall width can be tailored and the wall type modified. In
particular, the width of a 180 degree Neel wall can be strongly reduced or
increased by the constriction geometry compared with the wall in unconstrained
systems.Comment: 4 pages, 6 figure
Regulation of MMP-9 by p53 in first trimester cytotrophoblastic cells
BACKGROUND The matrix metalloproteinase (MMP) family is known to play a key role in tissue remodelling during embryonic development and in pathological conditions, such as cardiovascular disease, arthritis and cancer metastasis. It has been shown previously that p53 regulates positively or negatively the expression of different MMPs. Because of p53 overexpression in trophoblastic cells, and its potential role in regulating MMP-2 and MMP-9 expression in different cell lines, we hypothesized that the expression of MMP-9 could also be regulated by p53 in first trimester cytotrophoblasts (CTB). METHODS and RESULTS Transfection experiments in CTB demonstrated that wild-type p53 down-regulates the −670 (P < 0.001) but not the −531 and −90 human MMP-9 promoter/CAT reporter plasmid activity, whereas p53 mutants partially lost this repressive activity. However, endogenous p53 is not able to regulate MMP-9 expression in CTB. The presence of high molecular weight complexes of p53 in CTB suggests a potential mechanism of inactivation of p53 transcriptional activity towards MMPs in these cells. CONCLUSIONS Although p53 is mutated in trophoblast, it is functionally incompetent towards MMPs in these cell
Improving the chance of cure of follicular lymphoma by combining immunotherapy and radioimmunotherapy based on anti-CD20 antibodies?
GRP78 as a marker of pre-eclampsia: an exploratory study
Although the exact mechanisms that lead to shallow invasion or defective trophoblastic differentiation in pre-eclampsia are still unknown, it is widely admitted that the etiology of pre-eclampsia is a defect in trophoblast invasion of the uterine spiral arteries. We have previously observed that the status of a chaperone protein, glucose regulated protein 78 (GRP78) is associated with the invasive properties of cytotrophoblastic cells; we therefore hypothesized that circulating GRP78 could serve as a diagnostic tool in pre-eclampsia. In a prospective case-control study, we quantified GRP78 autoantibodies, complexes of GRP78 with autoantibodies and GRP78 (C-term fragment, N-term fragment and full-length GRP78) by ELISA. Plasma from women diagnosed with pre-eclampsia (n = 16), from women during the first trimester of pregnancy who subsequently developed pre-eclampsia (n = 10) and from healthy pregnant women (controls, n = 58 at term, n = 26 at first trimester) were analysed and compared. We observed no significant difference between pre-eclamptic and healthy pregnant women for autoantibodies-GRP78 complexes or total GRP78 at both first trimester and at delivery. In contrast, the ratio of C-terminal GRP78 over full length GRP78 was significantly different in plasma of pre-eclamptic patients as compared with controls both during first trimester (P < 0.004) and at term (P < 0.0001). Our findings suggest that circulating C-terminal GRP78 reflect the invasive properties of cells, and could be used as a predictive marker for pre-eclampsia early in pregnanc
Functional interaction between PML and SATB1 regulates chromatin-loop architecture and transcription of the MHC class I locus
Method, equipment and exemplary results for harmonized UFP number and size distribution measurements following CEN/TS 16976 and CEN/ TS 17434
Direct observation of domain-wall configurations transformed by spin currents
Direct observations of current-induced domain-wall propagation by
spin-polarized scanning electron microscopy are reported. Current pulses move
head-to-head as well as tail-to-tail walls in sub-micrometer Fe_{20}Ni_{80}
wires in the direction of the electron flow, and a decay of the wall velocity
with the number of injected current pulses is observed. High-resolution images
of the domain walls reveal that the wall spin structure is transformed from a
vortex to a transverse configuration with subsequent pulse injections. The
change in spin structure is directly correlated with the decay of the velocity.Comment: 5 pages, 3 figure
Characterisation of a self-sustained, water-based condensation particle counter for aircraft cruising pressure level operation
Aerosol particle number concentration measurements are a
crucial part of aerosol research. Vertical profile measurements and
high-altitude/low-pressure performance of the respective instruments become
more important for remote sensing validation and a vital tool for the
observation of climate variables. This study tests the new, commercially
available water condensation particle counter (MAGICÂ 210-LP) for the
deployment at aircraft cruising pressure levels that the European research
infrastructure IAGOS (In-service Aircraft for a Global Observing System;
http://www.iagos.org, last access: 2Â May 2023) is aiming for by operating measurement instrumentation onboard passenger aircraft. We conducted laboratory experiments for conditions
to simulate passenger aircraft flight altitude at operation pressure. We
demonstrate that this type of water condensation particle counter shows
excellent agreement with a butanol-based instrument used in parallel. A
Faraday cup aerosol electrometer serves as the reference instrument.
Experiments are performed with test aerosol ammonium sulfate and fresh
combustion soot at pressure levels ranging from 700 to 200 hPa. For soluble particles like ammonium sulfate, the 50 % detection efficiency cut-off diameter (D50) is around 5 nm and does not differ significantly for all
performed experiments. For non-soluble fresh soot particles, the D50
cut-off diameter of approximately 10 nm does not vary substantially as a
function of pressure, whereas the 90 % detection efficiency cut-off
diameter D90 increases from 19 nm at 700 hPa to 37 nm at 200 hPa. The overall counting efficiency for particles larger than 40 nm reaches 100 % for working pressures of 200 hPa and higher.</p
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