1,311 research outputs found
Influence of deflocculant on the isoelectric point of refractory powders: Considerations on the action of deflocculant
Isoelectric point changes in suspensions of refractory materials vis-a-vis the role of deflocculants used in monolithic refractories were investigated by considering the mineral compositions and adsorbed ions in four kinds of clay. Three types of curves represented the relation between the isoelectric point and the deflocculant. The surface charge of clay particles in the suspensions became negative as a result of the deflocculant, since the isoelectric point of suspensions decreased as the deflocculant was added. The isoelectric point changes of calcined alumina were also compared with those of the clays, and a similar phenomenon was observed, except that the deflocculant dispersed the calcined alumina better than it did the clays. A simple model was used to analyze the results
Observation of Self-binding in Monolayer He
We report clear experimental signatures of the theoretically unexpected
gas-liquid transition in the first three monolayers of He adsorbed on
graphite. The transition is inferred from the linear density dependence of the
-coefficient of the heat capacity measured in the degenerate region (2
80 mK) below a critical liquid density (). Surprisingly,
the measured values (0.60.9 nm) are nearly the same
for all these monolayers in spite of their quite different environments. We
conclude that the ground-state of He in strict two dimensions is not a
dilute quantum gas but a self-bound quantum liquid with the lowest density ever
found.Comment: 5 pages, 4 figure
FK506 and Cyclosporin A Enhance IL-6 Production in Monocytes: A single-Cell Assay
The effect of FK506 and cyclosporin A (CsA) on the production of
interleukin 6 (IL-6) in adherent monocytes was studied at a
single-cell level by the avidinbiotin- peroxidase complex methods.
The percentage of IL-6-producing monocytes increased when stimulated
with lipopolysaccharide (LPS) at concentrations between 10 ng/ml and
10 μg/ml, in a dose dependent manner. Both FK506 and CsA
enhanced the percentage of IL-6- producing monocytes stimulated with
100 pg/ml-1 μg/ml of LPS up to values near those
obtained with 10 μg/ml of LPS. The enhancement by FK506 and
CsA was not seen when monocytes were stimulated with a high
concentration of LPS (10 μg/ml). When monocytes were
stimulated with a low concentration of LPS (10 ng/ml), FK506 and
CsA enhanced IL-6 production in a dose dependent manner, at a drug
concentration of 0.12 nM–1.2 μM (0.1–1 000 ng/ml)
for FK506 and 0.83 nM–8.3 μM (1–10 000 ng/ml) for
CsA. The optimal effect of FK506 was achieved at a concentration
7-fold lower than that of CsA. In contrast, production of turnout
necrosis factor-α (TNFα and interleukin 1β
(IL-1β) was slightly suppressed by FK506 and CsA at the
concentrations tested. Moreover, pretreatment of monocytes with
FK506 and CsA had a significant enhancing effect on LPS-induced IL-6
production, while treatment with FK506 or CsA after LPS stimulation
had no effects on IL-6 production, suggesting that the enhancing
effect of each drug is exerted before LPS stimulation or at an early
stage of the post-receptor pathway after LPS stimulation. These
experiments demonstrate that FK506 and CsA can selectively enhance
IL-6 production in monocytes under certain conditions in
vitro and, possibly, also in vivo
Linear-stability analysis of plane beds under flows with suspended loads
Plane beds develop under flows in fluvial and marine environments; they are recorded as parallel lamination in sandstone beds, such as those found in turbidites. However, whereas turbidites typically exhibit parallel lamination, they rarely feature dune-scale cross-lamination. Although the reason for the scarcity of dune-scale cross-lamination in turbidites is still debated, the formation of dunes may be dampened by suspended loads. Here, we perform, for the first time, linear-stability analysis to show that flows with suspended loads facilitate the formation of plane beds. For a fine-grained bed, a suspended load can promote the formation of plane beds and dampen the formation of dunes. These results of theoretical analysis were verified with observational data of plane beds under open-channel flows. Our theoretical analysis found that suspended loads promote the formation of plane beds, which suggests that the development of dunes under turbidity currents is suppressed by the presence of suspended loads.</p
Sex differences in gene expression and proliferation are dependent on the epigenetic modifier HP1γ
Summary Sex differences in growth rate in very early embryos have been recognized in a variety of mammals and attributed to sex-chromosome complement effects as they occur before overt sexual differentiation. We previously found that sex-chromosome complement, rather than sex hormones regulates heterochromatin-mediated silencing of a transgene and autosomal gene expression in mice. Here, sex dimorphism in proliferation was investigated. We confirm that male embryonic fibroblasts proliferate faster than female fibroblasts and show that this proliferation advantage is completely dependent upon heterochromatin protein 1 gamma (HP1γ). To determine whether this sex-regulatory effect of HP1γ was a more general phenomenon, we performed RNA sequencing on MEFs derived from males and females, with or without HP1γ. Strikingly, HP1γ was found to be crucial for regulating nearly all sexually dimorphic autosomal gene expression because deletion of the HP1γ gene in males abolished sex differences in autosomal gene expression. The identification of a key epigenetic modifier as central in defining gene expression differences between males and females has important implications for understanding physiological sex differences and sex bias in disease
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