84 research outputs found
Inclusive Dielectron Production in Ar+KCl Collisions at 1.76 AGeV studied with HADES
Results of the HADES measurement of inclusive dielectron production in Ar+KCl
collisions at a kinetic beam energy of 1.76 AGeV are presented. For the first
time, high mass resolution spectroscopy was performed. The invariant mass
spectrum of dielectrons is compared with predictions of UrQMD and HSD transport
codes.Comment: 4 pages, 3 figures - To appear in the conference proceedings for
Quark Matter 2009, March 30 - April 4, Knoxville, Tennesse
Dilepton production in pp and CC collisions with HADES
Dilepton production has been measured with HADES, the "High Acceptance
DiElectron Spectrometer". In pp collisions at 2.2GeV kinetic beam energy,
exclusive eta production and the Dalitz decay eta -> gamma e+e- has been
reconstructed. The electromagnetic form factor is well in agreement with
existing data. In addition, an inclusive e+e- spectrum from the C+C reaction at
2AGeV is presented and compared with a thermal model.Comment: 11 pages, 3 figures, proceedings of the IVth International Conference
on Quarks and Nuclear Physics, Madrid, June 5th-10th, submitted to
Eur.Phys.J.
Future perspectives at SIS-100 with HADES-at-FAIR
Currently, the HADES spectrometer undergoes un upgrade program to be prepared
for measurements at the upcoming SIS-100 synchrotron at FAIR. We describe the
current status of the HADES di-electron measurements at the SIS-18 and our
future plans for SIS-100.Comment: Invited contribution presented at the XLVII International Winter
Meeting on Nuclear Physics, Bormio (Italy), Jan. 26-30, 200
Magnesium reduces calcification in bovine vascular smooth muscle cells in a dose-dependent manner
WOS: 000300421300010PubMed ID: 21750166Vascular calcification (VC), mainly due to elevated phosphate levels, is one major problem in patients suffering from chronic kidney disease. In clinical studies, an inverse relationship between serum magnesium and VC has been reported. However, there is only few information about the influence of magnesium on calcification on a cellular level available. Therefore, we investigated the effect of magnesium on calcification induced by beta-glycerophosphate (BGP) in bovine vascular smooth muscle cells (BVSMCs). BVSMCs were incubated with calcification media for 14 days while simultaneously increasing the magnesium concentration. Calcium deposition, transdifferentiation of cells and apoptosis were measured applying quantification of calcium, von Kossa and Alizarin red staining, real-time reverse transcription-polymerase chain reaction and annexin V staining, respectively. Calcium deposition in the cells dramatically increased with addition of BGP and could be mostly prevented by co-incubation with magnesium. Higher magnesium levels led to inhibition of BGP-induced alkaline phosphatase activity as well as to a decreased expression of genes associated with the process of transdifferentiation of BVSMCs into osteoblast-like cells. Furthermore, estimated calcium entry into the cells decreased with increasing magnesium concentrations in the media. In addition, higher magnesium concentrations prevented cell damage (apoptosis) induced by BGP as well as progression of already established calcification. Higher magnesium levels prevented BVSMC calcification, inhibited expression of osteogenic proteins, apoptosis and further progression of already established calcification. Thus, magnesium is influencing molecular processes associated with VC and may have the potential to play a role for VC also in clinical situations.Fresenius Medical Care Deutschland GmbH, GermanyThis study was supported by Fresenius Medical Care Deutschland GmbH, Germany
Phi decay: a relevant source for K- production at SIS energies?
We present phase space distributions and multiplicities of K+, K- and phi
mesons produced in Ar+KCl reactions at a kinetic beam energy of 1.756 AGeV and
measured with the HADES spectrometer. The inverse slope parameters and yields
of kaons supplement the systematics of previous measurements. The percentage of
K- mesons coming fromphi decay is found to be 18+- 7%
Charged pion production in C+C and Ar+KCl collisions measured with HADES
Results of a study of charged pion production in 12C+12C collisions at
incident beam energies of 1A GeV and 2A GeV, and 40Ar+natKCl at 1.76AGeV, using
the spectrometer HADES at GSI, are presented. We have performed a measurement
of the transverse momentum distributions of pi+- mesons covering a fairly large
rapidity interval, in case of the C+C collision system for the first time. The
yields, transverse mass and angular distributions are compared with a transport
model as well as with existing data from other experiments.Comment: 7 pages, 2 figures Contribution presented at the XLVII International
Winter Meeting on Nuclear Physics, Bormio (Italy), Jan. 26-30, 200
Measurement of charged pions in 12C + 12C collisions at 1A GeV and 2A GeV with HADES
We present the results of a study of charged pion production in 12C + 12C
collisions at incident beam energies of 1A GeV and 2A GeV using the HADES
spectrometer at GSI. The main emphasis of the HADES program is on the
dielectron signal from the early phase of the collision. Here, however, we
discuss the data with respect to the emission of charged hadrons, specifically
the production of pi+- mesons, which are related to neutral pions representing
a dominant contribution to the dielectron yield. We have performed the first
large-angular range measurement of the distribution of pi+- mesons for the 12C
+ 12C collision system covering a fairly large rapidity interval. The pion
yields, transverse-mass and angular distributions are compared with
calculations done within a transport model, as well as with existing data from
other experiments. The anisotropy of pion production is systematically
analyzed.Comment: 15 pages, 13 figures, v2 - the text unchanged, only full author list
added to METADATA (in v1 only the first author and collaboration name),
reference to published paper adde
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