1,574 research outputs found
Effect of bonding of a CO molecule on the conductance of atomic metal wires
We have measured the effect of bonding of a CO molecule on the conductance of
Au, Cu, Pt, and Ni atomic contacts at 4.2 K. When CO gas is admitted to the
metal nano contacts, a conductance feature appears in the conductance histogram
near 0.5 of the quantum unit of conductance, for all metals. For Au, the
intensity of this fractional conductance feature can be tuned with the bias
voltage, and it disappears at high bias voltage (above 200 mV). The
bonding of CO to Au appears to be weakest, and associated with monotomic Au
wire formation.Comment: 6 figure
Occurrence of mylonite zones and pseudotachylyte veins around the base of the upper crust: An example from the southern Hidaka metamorphic belt, Samani area, Hokkaido, Japan
Abnormal expansion of naΓ―ve B lymphocytes after unrelated cord blood transplantation β a case report
A 33-year-old woman underwent unrelated cord blood transplantation (U-CBT) for myelodysplastic syndrome (MDS)-related secondary AML. She showed impressive increases in the number of CD19(+) B cells in bone marrow and CD19(+)27(β)IgD(+) B cells in peripheral blood from about 1 month to 3 months after U-CBT. The serum level of IL-6 temporarily increased after transplantation, and this increase seemed to be correlated with the expansion of CD19(+) B cells. Although, compared with BMT, little is known about the kinetics of hematological and immunological reconstitution in U-CBT, there was initial B-cell recovery after CBT as some described. This B cell recovery may be associated with a high number of B-cell precursors present in cord blood (CB). The phenomenon of naΓ―ve B lymphocyte expansion that we found might be associated with a high number of B-cell precursors present in CB
Effects of antenatal betamethasone on preterm human and mouse ductus arteriosus: comparison with baboon data.
BackgroundAlthough studies involving preterm infants β€34 weeks gestation report a decreased incidence of patent ductus arteriosus after antenatal betamethasone, studies involving younger gestation infants report conflicting results.MethodsWe used preterm baboons, mice, and humans (β€276/7 weeks gestation) to examine betamethasone's effects on ductus gene expression and constriction both in vitro and in vivo.ResultsIn mice, betamethasone increased the sensitivity of the premature ductus to the contractile effects of oxygen without altering the effects of other contractile or vasodilatory stimuli. Betamethasone's effects on oxygen sensitivity could be eliminated by inhibiting endogenous prostaglandin/nitric oxide signaling. In mice and baboons, betamethasone increased the expression of several developmentally regulated genes that mediate oxygen-induced constriction (K+ channels) and inhibit vasodilator signaling (phosphodiesterases). In human infants, betamethasone increased the rate of ductus constriction at all gestational ages. However, in infants born β€256/7 weeks gestation, betamethasone's contractile effects were only apparent when prostaglandin signaling was inhibited, whereas at 26-27 weeks gestation, betamethasone's contractile effects were apparent even in the absence of prostaglandin inhibitors.ConclusionsWe speculate that betamethasone's contractile effects may be mediated through genes that are developmentally regulated. This could explain why betamethasone's effects vary according to the infant's developmental age at birth
Abnormal expression of p27kip1 protein in levator ani muscle of aging women with pelvic floor disorders β a relationship to the cellular differentiation and degeneration
BACKGROUND: Pelvic floor disorders affect almost 50% of aging women. An important role in the pelvic floor support belongs to the levator ani muscle. The p27/kip1 (p27) protein, multifunctional cyclin-dependent kinase inhibitor, shows changing expression in differentiating skeletal muscle cells during development, and relatively high levels of p27 RNA were detected in the normal human skeletal muscles. METHODS: Biopsy samples of levator ani muscle were obtained from 22 symptomatic patients with stress urinary incontinence, pelvic organ prolapse, and overlaps (age range 38β74), and nine asymptomatic women (age 31β49). Cryostat sections were investigated for p27 protein expression and type I (slow twitch) and type II (fast twitch) fibers. RESULTS: All fibers exhibited strong plasma membrane (and nuclear) p27 protein expression. cytoplasmic p27 expression was virtually absent in asymptomatic women. In perimenopausal symptomatic patients (ages 38β55), muscle fibers showed hypertrophy and moderate cytoplasmic p27 staining accompanied by diminution of type II fibers. Older symptomatic patients (ages 57β74) showed cytoplasmic p27 overexpression accompanied by shrinking, cytoplasmic vacuolization and fragmentation of muscle cells. The plasma membrane and cytoplasmic p27 expression was not unique to the muscle cells. Under certain circumstances, it was also detected in other cell types (epithelium of ectocervix and luteal cells). CONCLUSIONS: This is the first report on the unusual (plasma membrane and cytoplasmic) expression of p27 protein in normal and abnormal human striated muscle cells in vivo. Our data indicate that pelvic floor disorders are in perimenopausal patients associated with an appearance of moderate cytoplasmic p27 expression, accompanying hypertrophy and transition of type II into type I fibers. The patients in advanced postmenopause show shrinking and fragmentation of muscle fibers associated with strong cytoplasmic p27 expression
Food and Habitat Selection of Lepus brachyurus lyoni
We determined the environmental requirements for Lepus brachyurus lyoni on Sado Island, Japan. during the winter when food resources are low Flare track survey sites were classified by vegetation type. The movement distances of hares, which indicated habitat preference, were evaluated as the relative length of tracks in a I-ha area In addition, we examined browse marks on plants and the protein content of plants to determine the preferred plant species. Movement distances of hares decreased significantly with increasing tree stand height, mean tree diameter. basal area of the tree stand, and forest canopy closure, but increased with branch-and-stem density. The percentage of browse marks Oil the branches of tree/shrub species decreased significantly with increasing branch-and-stem diameter The rate of feeding increased significantly with increased protein content in the branches These findings suggest that hares prefer shrub stands with high branch-and-stem density to mature forests. which have lower branch-and-stem densities Hares also prefer branches and stems containing large amounts of protein Young stands offering many shrub species as food resources and shelter constitute preferable environments for hare
ABL1 regulates spindle orientation in adherent cells and mammalian skin
Despite the growing evidence for the regulated spindle orientation in mammals, a systematic approach for identifying the responsible genes in mammalian cells has not been established. Here we perform a kinase-targeting RNAi screen in HeLa cells and identify ABL1 as a novel regulator of spindle orientation. Knockdown of ABL1 causes the cortical accumulation of Leu-Gly-Asn repeat-enriched-protein (LGN), an evolutionarily conserved regulator of spindle orientation. This results in the LGN-dependent spindle rotation and spindle misorientation. In vivo inactivation of ABL1 by a pharmacological inhibitor or by ablation of the abl1 gene causes spindle misorientation and LGN mislocalization in mouse epidermis. Furthermore, ABL1 directly phosphorylates NuMA, a binding partner of LGN, on tyrosine 1774. This phosphorylation maintains the cortical localization of NuMA during metaphase, and ensures the LGN/NuMA-dependent spindle orientation control. This study provides a novel approach to identify genes regulating spindle orientation in mammals and uncovers new signalling pathways for this mechanism
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