1,755 research outputs found
The rapid response of ovarian and uterine veins of mice to sex hormones.
Subcutaneous injections in sesame oil of testosterone and estradiol-17 beta into ovariectomized and ovariectomized-hysterectomized young adult mice were followed in six hours or less by significant increases in the diameters of the ovarian and uterine veins as compared to the same vessels in sesame oil-injected controls. The circumflex iliac, femoral, and superior mesenteric veins and inferior vena cava failed to respond. The results demonstrate the specificity and speed of response of ovarian and uterine veins of mice and the control of the response by sex hormones
Bladder-cancer-associated mutations in RXRA activate peroxisome proliferator-activated receptors to drive urothelial proliferation
Multimodality Quantitative Imaging of Aortic Root for Transcatheter Aortic Valve Implantation More Complex Than It Appears**Editorials published in the Journal of the American College of Cardiologyreflect the views of the authors and do not necessarily represent the views of JACCor the American College of Cardiology.
Volumetric analysis of LAD-diagonal and LCX-obtuse marginal coronary bifurcations: An intravascular ultrasound study
Fecha errónea en el original
Increased Recombination Between Active tRNA Genes
Transfer RNA genes are distributed throughout eukaryotic genomes, and are frequently found as multicopy families. In Saccharomyces cerevisiae, tRNA gene transcription by RNA polymerase III suppresses nearby transcription by RNA polymerase II, partially because the tRNA genes are clustered near the nucleolus. We have tested whether active transcription of tRNA genes might also suppress recombination, since recombination between identical copies of the repetitive tRNA genes could delete intervening genes and be detrimental to survival. The opposite proved to be the case. Recombination between active tRNA genes was elevated, but only when both genes are transcribed. We also tested the effects of tRNA genes on recombination between the direct terminal repeats of a neighboring retrotransposon, since most Ty retrotransposons reside next to tRNA genes, and the selective advantage of this arrangement is not known.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63113/1/dna.2006.25.359.pd
Relationship Between Atheroma Regression and Change in Lumen Size After Infusion of Apolipoprotein A-I Milano
ObjectivesThe aim of this study was to determine the relationship between atheroma regression and arterial wall remodeling.BackgroundInfusion of reconstituted high-density lipoprotein (rHDL) containing recombinant apolipoprotein A-I Milano (AIM) has been reported to promote rapid regression of coronary atherosclerosis. The current study analyzed intravascular ultrasound (IVUS) to define the changes that take place in the arterial wall that accompanied atheroma regression in this study.MethodsForty-seven patients, ages 30 to 75 years, after an acute coronary syndrome were randomized to receive five weekly infusions of placebo or rHDL containing either low- or high-dose AIM. External elastic membrane (EEM) and lumen volumes were compared between coronary IVUS studies at baseline and follow-up.ResultsIn comparison with baseline, infusion of rHDL was associated with a 4.6% reduction in EEM volume. Lumen volume did not change. In 10-mm arterial subsegments with the greatest plaque burden at baseline, atheroma volume regressed by 10.9% with a similar reduction in EEM volume but with no change in lumen size. In contrast, EEM and atheroma volume did not change in the 10-mm segments containing the least plaque burden. The reduction in EEM in the most diseased segments was only apparent in subjects who underwent plaque regression. Reduction in EEM volume correlated with the decreased atheroma volume (r = 0.62), but there was no correlation between change in lumen size and change in plaque volume.ConclusionsRemodeling of the arterial wall is a focal and heterogeneous process. After infusion of rHDL containing AIM, regression of coronary atherosclerosis is accompanied by reverse remodeling of the EEM, resulting in no change in luminal dimensions
Ideal Bandgap in a 2D Ruddlesden-Popper Perovskite Chalcogenide for Single-junction Solar Cells
Transition metal perovskite chalcogenides (TMPCs) are explored as stable,
environmentally friendly semiconductors for solar energy conversion. They can
be viewed as the inorganic alternatives to hybrid halide perovskites, and
chalcogenide counterparts of perovskite oxides with desirable optoelectronic
properties in the visible and infrared part of the electromagnetic spectrum.
Past theoretical studies have predicted large absorption coefficient, desirable
defect characteristics, and bulk photovoltaic effect in TMPCs. Despite recent
progresses in polycrystalline synthesis and measurements of their optical
properties, it is necessary to grow these materials in high crystalline quality
to develop a fundamental understanding of their optical properties and evaluate
their suitability for photovoltaic application. Here, we report the growth of
single crystals of a two-dimensional (2D) perovskite chalcogenide, Ba3Zr2S7,
with a natural superlattice-like structure of alternating double-layer
perovskite blocks and single-layer rock salt structure. The material
demonstrated a bright photoluminescence peak at 1.28 eV with a large external
luminescence efficiency of up to 0.15%. We performed time-resolved
photoluminescence spectroscopy on these crystals and obtained an effective
recombination time of ~65 ns. These results clearly show that 2D
Ruddlesden-Popper phases of perovskite chalcogenides are promising materials to
achieve single-junction solar cells.Comment: 4 Figure
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