241 research outputs found
The Stellar Mass, Star Formation Rate and Dark Matter Halo Properties of LAEs at
We present average stellar population properties and dark matter halo masses
of \lya emitters (LAEs) from SED fitting and clustering analysis,
respectively, using objects () in four separate
fields of deg in total. With an average stellar mass of and star formation rate of , the LAEs lie on an extrapolation
of the star-formation main sequence (MS) to low stellar mass. Their effective
dark matter halo mass is estimated to be $4.0_{-2.9}^{+5.1} \times 10^{10}\
{\mathrm M_\odot}1.22^{+0.16}_{-0.18}z \sim 21.8\, \pm\, 0.396\%.
However, the difference in the bias values can be explained if cosmic variance
is taken into account. If such a low halo mass implies a low HI gas mass, this
result appears to be consistent with the observations of a high \lya escape
fraction. With the low halo masses and ongoing star formation, our LAEs have a
relatively high stellar-to-halo mass ratio (SHMR) and a high efficiency of
converting baryons into stars. The extended Press-Schechter formalism predicts
that at z=0z \sim 2$ as some previous
studies have reported for the LMC itself.Comment: 34 pages, 15 figures, 6 tables. Accepted for publication in PAS
Relationship of IE and oral conditions
Objectives
Infective endocarditis (IE) is a life-threatening infectious disease, but the pathogenesis of the disease remains uncertain. The objective of this study was to examine whether oral infectious conditions are associated with the occurrence of IE in valvular heart disease (VHD) patients.
Materials and Methods
A total of 119 periodontitis (P) patients with or without VHD were enrolled, and cross-sectional analyses were performed. Patients were classified as follows: 1) mild-to-moderate P without VHD, 2) mild-to-moderate P with VHD, 3) severe P without VHD, or 4) severe P with VHD. A total of 78 VHD patients were classified as 1) VHD without IE or 2) VHD with IE. Conditional logistic regression analysis was performed to compute the odds ratio (OR) and 95% confidence interval (CI).
Results
No significant differences were observed between patients with or without VHD in oral conditions. A significant increase in the percentage of alveolar bone loss in VHD patients with IE was observed compared with that of patients without IE. The ratio of both Porphyromonas gingivalis (Pg) IgG titer>1.68 and Pg fimA type II genotype in patients with IE was significantly higher than in patients without IE. There was a significant correlation between the occurrence of IE and clinical oral findings (number of remaining teeth: OR, 0.17; rate of alveolar bone loss>40%: OR, 11.8).
Conclusions
VHD patients with IE might have severe periodontitis compared with patients without IE, although further investigation will be needed because this is based on only 7 VHD patients with IE.
Clinical relevance
The patients with IE had fewer remaining teeth, more advanced bone resorption compared with those of patients without IE. These findings suggest a possible association between the occurrence of IE and periodontal infection
Adsorption of Laminin on Hydroxyapatite and Alumina and the MC3T3-E1 Cell Response
Artificial hydroxyapatite (HAp) is osteoconductive, but the mechanism is still unclear. It is likely that some serum proteins are adsorbed onto HAp and influence its osteoconductivity. We investigated the adsorption behavior of laminin (LN), which was isolated from murine Engelbreth–Holm–Swarm sarcoma, onto HAp and compared it with nonosteoconductive alpha-type alumina (α-Al2O3). Cell adhesion, spreading, and proliferation on native and LN-adsorbed discs of HAp or α-Al2O3 were examined using murine MC3T3-E1 osteoblastic cells. A larger amount of LN adsorbed onto HAp than α-Al2O3 despite the electrostatic repulsion between LN and HAp, suggesting the specific adsorption of LN onto HAp. The LN adsorbed onto HAp remarkably enhanced initial attachment and spreading of MC3T3-E1 cells, but subsequent proliferation of MC3T3-E1 cells was influenced by the type of material rather than LN adsorption. These fundamental findings imply that LN adsorbed on HAp could trigger osteoconductivity in vivo, aiding in the development of novel biomaterials that specifically adsorb LN and effectively enhance cell attachment and spreading
Fibronectin Adsorption on Osteoconductive Hydroxyapatite and Non-osteoconductive α-alumina
The osteoconductivity mechanism of hydroxyapatite (HAp) has not been elucidated. It is hypothesized that specific proteins adsorb on HAp, promoting its osteoconductivity. To verify this hypothesis, we compared the adsorption behavior of fibronectin (Fn) on HAp powder and on α-alumina (α-Al2O3) powder, a material with no osteoconductivity. More Fn adsorbed on α-Al2O3 than on HAp, irrespective of the Fn concentration, and there was no significant difference in the secondary structure of Fn adsorbed on HAp and α-Al2O3. Further, it is possible that Fn did not adsorb on HAp and α-Al2O3 through the Arg-Gry-Asp motif of Fn. The amount of Fn adsorbed on HAp oriented to the a(b)-axis with very little decrease in carbonate and the adsorbed Fn had a smaller α-helix structure content. The results suggest that the secondary and/or higher-order structure rather than the amount of adsorbed Fn might affect the osteoconductivity of HAp, which might be electrostatically controlled by the crystal face orientation and/or carbonate content of HAp, although this should be confirmed by a cell culture test in the future
Adsorption characteristics of bovine serum albumin onto alumina with a specific crystalline structure
Bone cement containing alumina particles with a specific crystalline structure exhibits the ability to bond with bone. These particles (AL-P) are mainly composed of delta-type alumina (δ-Al2O3). It is likely that some of the proteins present in the body environment are adsorbed onto the cement and influence the expression of its bioactivity. However, the effect that this adsorption of proteins has on the bone-bonding mechanism of bone cement has not yet been elucidated. In this study, we investigated the characteristics of the adsorption of bovine serum albumin (BSA) onto AL-P and compared them with those of its adsorption onto hydroxyapatite (HA), which also exhibits bone-bonding ability, as well as with those of adsorption onto alpha-type alumina (α-Al2O3), which does not bond with bone. The adsorption characteristics of BSA onto AL-P were very different from those onto α-Al2O3 but quite similar to those onto HA. It is speculated that BSA is adsorbed onto AL-P and HA by interionic interactions, while it is adsorbed onto α-Al2O3 by electrostatic attraction. The results suggest that the specific adsorption of albumin onto implant materials might play a role in the expression of the bone-bonding abilities of the materials
FOREVER22: the first bright galaxies with population III stars at redshifts and comparisons with JWST data
We study the formation of the first galaxies in overdense regions modelled by
the FORmation and EVolution of galaxies in Extremely overdense Regions
motivated by SSA22 (FOREVER22) simulation project. Our simulations successfully
reproduce the star formation rates and the relations
of candidate galaxies at observed by the James Webb Space
Telescope (JWST). We suggest that the observed galaxies are hosted by
dark-matter haloes with and are in
short-period starburst phases. On the other hand, even simulated massive
galaxies in overdense regions cannot reproduce the intense star formation rates
and the large stellar masses of observed candidates at . Also, we
show that the contribution of population III stars to the UV flux decreases as
the stellar mass increases and it is a few percent for galaxies with . Therefore, a part of the observed flux by
JWST could be the light from population III stars. Our simulations suggest that
the UV flux can be dominated by population III stars and the UV-slope shows
if future observations would reach galaxies with at of which the mass fraction
of population III stars can be greater than 10 percent.Comment: 9 pages, 6 figures, accepted for publication in MNRA
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