353 research outputs found
Mesenchyme Homeobox 2 Enhances Migration of Endothelial Colony Forming Cells Exposed to Intrauterine Diabetes Mellitus
Diabetes mellitus (DM) during pregnancy has long-lasting implications for the fetus, including cardiovascular morbidity. Previously, we showed that endothelial colony forming cells (ECFCs) from DM human pregnancies have decreased vasculogenic potential. Here, we evaluate whether the molecular mechanism responsible for this phenotype involves the transcription factor, Mesenchyme Homeobox 2 (MEOX2). In human umbilical vein endothelial cells, MEOX2 upregulates cyclin-dependent kinase inhibitor expression, resulting in increased senescence and decreased proliferation. We hypothesized that dysregulated MEOX2 expression in neonatal ECFCs from DM pregnancies decreases network formation through increased senescence and altered cell cycle progression. Our studies show that nuclear MEOX2 is increased in ECFCs from DM pregnancies. To determine if MEOX2 is sufficient and/or required to induce impaired network formation, MEOX2 was overexpressed and depleted in ECFCs from control and DM pregnancies, respectively. Surprisingly, MEOX2 overexpression in control ECFCs resulted in increased network formation, altered cell cycle progression, and increased senescence. In contrast, MEOX2 knockdown in ECFCs from DM pregnancies led to decreased network formation, while cell cycle progression and senescence were unaffected. Importantly, migration studies demonstrated that MEOX2 overexpression increased migration, while MEOX2 knockdown decreased migration. Taken together, these data suggest that altered migration may be mediating the impaired vasculogenesis of ECFCs from DM pregnancies. While initially believed to be maladaptive, these data suggest that MEOX2 may serve a protective role, enabling increased vessel formation despite exposure to a DM intrauterine environment. J. Cell. Physiol. 232: 1885-1892, 2017
A comparison of forward and backward pp pair knockout in 3He(e,e'pp)n
Measuring nucleon-nucleon Short Range Correlations (SRC) has been a goal of
the nuclear physics community for many years. They are an important part of the
nuclear wavefunction, accounting for almost all of the high-momentum strength.
They are closely related to the EMC effect. While their overall probability has
been measured, measuring their momentum distributions is more difficult. In
order to determine the best configuration for studying SRC momentum
distributions, we measured the He reaction, looking at events
with high momentum protons ( GeV/c) and a low momentum neutron
( GeV/c). We examined two angular configurations: either both protons
emitted forward or one proton emitted forward and one backward (with respect to
the momentum transfer, ). The measured relative momentum distribution
of the events with one forward and one backward proton was much closer to the
calculated initial-state relative momentum distribution, indicating that
this is the preferred configuration for measuring SRC.Comment: 8 pages, 9 figures, submitted to Phys Rev C. Version 2 incorporates
minor corrections in response to referee comment
Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab
We present measurements of the differential cross section and Lambda recoil
polarization for the gamma p to K+ Lambda reaction made using the CLAS detector
at Jefferson Lab. These measurements cover the center-of-mass energy range from
1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles.
Independent analyses were performed using the K+ p pi- and K+ p (missing pi -)
final-state topologies; results from these analyses were found to exhibit good
agreement. These differential cross section measurements show excellent
agreement with previous CLAS and LEPS results and offer increased precision and
a 300 MeV increase in energy coverage. The recoil polarization data agree well
with previous results and offer a large increase in precision and a 500 MeV
extension in energy range. The increased center-of-mass energy range that these
data represent will allow for independent study of non-resonant K+ Lambda
photoproduction mechanisms at all production angles.Comment: 22 pages, 16 figure
Measurement of the nuclear multiplicity ratio for hadronization at CLAS
The influence of cold nuclear matter on lepto-production of hadrons in
semi-inclusive deep inelastic scattering is measured using the CLAS detector in
Hall B at Jefferson Lab and a 5.014 GeV electron beam. We report the
multiplicity ratios for targets of C, Fe, and Pb relative to deuterium as a
function of the fractional virtual photon energy transferred to the
and the transverse momentum squared of the . We find that the
multiplicity ratios for are reduced in the nuclear medium at high
and low , with a trend for the transverse momentum to be
broadened in the nucleus for large .Comment: Submitted to Phys. Lett.
Near-threshold Photoproduction of Phi Mesons from Deuterium
We report the first measurement of the differential cross section on
-meson photoproduction from deuterium near the production threshold for a
proton using the CLAS detector and a tagged-photon beam in Hall B at Jefferson
Lab. The measurement was carried out by a triple coincidence detection of a
proton, and near the theoretical production threshold of 1.57 GeV.
The extracted differential cross sections for the initial
photon energy from 1.65-1.75 GeV are consistent with predictions based on a
quasifree mechanism. This experiment establishes a baseline for a future
experimental search for an exotic -N bound state from heavier nuclear
targets utilizing subthreshold/near-threshold production of mesons
Absorption of the and Mesons in Nuclei
Due to their long lifetimes, the and mesons are the ideal
candidates for the study of possible modifications of the in-medium
meson-nucleon interaction through their absorption inside the nucleus. During
the E01-112 experiment at the Thomas Jefferson National Accelerator Facility,
the mesons were photoproduced from H, C, Ti, Fe, and Pb targets. This
paper reports the first measurement of the ratio of nuclear transparencies for
the channel. The ratios indicate larger in-medium widths compared
with what have been reported in other reaction channels.Comment: 6 pages, 4 figure
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