Amorphous coatings with a composition of Fe
48Cr
15Mo
14C
15B
6Y
2 were prepared by means of high velocity oxygen fuel (HVOF) thermal spraying under different conditions. Microstructural studies show ...that the coatings present dense layered structure and low porosity with a fraction of nanocrystals precipitated. The porosity and amorphous fraction of the coatings decrease as the kerosene and oxygen flow increase within the parameter range examined. Corrosion behavior of the amorphous coatings was investigated by electrochemical measurement. The results show that the coatings are spontaneously passivated with wide passive region and low passive current density in 3.5% NaCl, 1
N HCl and 1
N H
2SO
4 solutions, and exhibit an excellent ability to resist localized corrosion. However, the corrosion resistance of the coatings decreases in 1
N NaOH solution with lower transpassive potential and passive region. In addition, the optimal spraying parameter improves the corrosion resistance of the amorphous coatings obviously due to the proper proportion of porosity and amorphous fraction.
Emerging evidence has shown that cancer stem cells (CSCs) are the cellular determinants to promote cancer invasion and metastasis. However, the mechanism underlying CSC invasion remains unknown. ...MicroRNAs are evolutionally conserved small noncoding RNAs that are critical for the regulation of gene expression, and their expressions are often dysregulated in cancers. In the present study, we demonstrated that two functionally related microRNAs, miR-20a and -106a (miR-20a/106a), were capable of enhancing the invasiveness of CD133(+) glioma stem cells (GSCs) isolated from both glioblastoma cell line U87 and primary human glioma specimens. We found that the level of miR-20a/106a in GSCs was significantly higher than that in the committed CD133(-) glioma cells, and correlated with the invasive capability of GSCs. By bioinformatic analysis, we identified tissue inhibitor of metalloproteinases-2 (TIMP-2) as one of the miR-20a/106a-targeted genes. TIMP-2 level correlated inversely with miR-20/106 expression. Directly targeting by miR-20a/106a on 3'-untranslation region (3'-UTR) of TIMP-2 mRNA was confirmed by 3'-UTR dual-luciferase reporter assay. Knockdown of miR-20a/106a in GSCs increased endogenous TIMP-2 protein abundance, thereby inhibiting GSC invasion. We also found that Nordy, a synthetic lipoxygenase inhibitor, inhibited GSC invasiveness by elevating the expression of TIMP-2 via downregulation of miR-20a/106a. Our results indicate that miR-20a/106a has a key role in GSC invasion and may serve as targets for treatment of glioblastoma.
Phosphatidylinositol-3 kinases (PI3K)-Protein kinase B (Akt)-mammalian target of rapamycin (mTOR) pathway plays an important role in the synthesis and secretion of triacylglycerol. However, the ...mechanism of PI3K-Akt-mTOR pathway in regulating lipid metabolism of goose liver was poorly understood. The purpose of this study was to determine how PI3K-Akt-mTOR pathway regulating lipid metabolic homeostasis in goose hepatocytes. Goose primary hepatocytes were treated with different PI3K-Akt-mTOR signal inhibitors (LY294002, rapamycin and NVP-BEZ235) for 24 h. The results showed that these inhibitors evidently inhibited PI3K-Akt-mTOR downstream signaling. Meanwhile, these PI3K-Akt-mTOR inhibitors reduced intracellular lipid accumulation, decreased the mRNA expression and protein content of genes involved in the de novo fatty acid synthesis, while increased the transcriptional and protein level of key factors involved in fatty acid oxidation and very low density lipoprotein (VLDL) assembly and secretion.
These findings suggested that the reduction of lipids accumulation induced-by inhibiting PI3K-Akt-mTOR pathway was closely linked to the decrease of lipogenesis, the increase of fatty acids oxidation, and the increase of VLDL assembly and secretion in goose hepatocytes.
We report the detailed electronic structure of WTe2 by high resolution angle-resolved photoemission spectroscopy. We resolved a rather complicated Fermi surface of WTe2. Specifically, there are in ...total nine Fermi pockets, including one hole pocket at the Brillouin zone center Γ, and two hole pockets and two electron pockets on each side of Γ along the Γ-X direction. Remarkably, we have observed circular dichroism in our photoemission spectra, which suggests that the orbital angular momentum exhibits a rich texture at various sections of the Fermi surface. This is further confirmed by our density-functional-theory calculations, where the spin texture is qualitatively reproduced as the conjugate consequence of spin-orbital coupling. Since the spin texture would forbid backscatterings that are directly involved in the resistivity, our data suggest that the spin-orbit coupling and the related spin and orbital angular momentum textures may play an important role in the anomalously large magnetoresistance of WTe2. Furthermore, the large differences among spin textures calculated for magnetic fields along the in-plane and out-of-plane directions also provide a natural explanation of the large field-direction dependence on the magnetoresistance.
Aims
The aims of this study were to investigate the effects of probiotics and antibiotics on microbial composition, short chain fatty acids (SCFAs) concentration and free fatty acid receptor 2/3 ...(FFAR2/3) expression in boiler chickens.
Methods and Results
A total of 150 1‐day‐old male broilers were randomly allocated into three groups, control (CON) group, probiotics (PB) group and antibiotics (ATB) group. Results indicated that PB improved the average body weight from 1 to 21 days and feed intake from 21 to 42 days (P < 0·05), while ATB improved the feed efficiency from 1 to 42 days (P < 0·05). Based on 16s rRNA sequencing, PB treatment increased the amount of kingdom bacteria, and the relative abundance of the main bacteria including acetate and butyrate producing bacteria of phylum Firmicutes, family Ruminococcaceae and genus Faecalibacterium. ATB treatment also increased the relative abundance of phylum Firmicutes, family Ruminococcaceae and Lachnospiraceae, however, it introduced some pathogenic bacteria, such as bacteria of family Rikenellaceae and Enterobacteriaceae. Gas chromatography and mass spectrometry (GC‐MS) assay revealed that PB increased acetate and butyrate concentrations at both 21 and 42 days, and propionate at 42 days in the colorectum. Moreover qRT‐PCR analysis showed PB treatment significantly activated the FFAR2/3 mRNA expressions. On the contrast, ATB treatment lowered the colorectal propionate at 21 days, and decreased acetate, propionate and butyrate concentrations at 42 days, accompanied with decreased FFAR2/3 mRNA expressions.
Conclusions
Compared to the CON birds, an enriched SCFAs producing bacteria with higher SCFAs contents and activated FFAR2/3 expressions are prominent features of PB birds. However, antibiotics treatment plays the reverse effect compared to PB treatment.
Significance and Impact of the Study
This study brings a significant idea that less SCFAs concentration may be another reason why the antibiotics inhibit the immune system development and immunity of the body.
A Nationwide Nitrogen Deposition Monitoring Network (NNDMN) containing 43 monitoring sites was established in China to measure gaseous NH3, NO2, and HNO3 and particulate NH4+ and NO3− in air and/or ...precipitation from 2010 to 2014. Wet/bulk deposition fluxes of Nr species were collected by precipitation gauge method and measured by continuous-flow analyzer; dry deposition fluxes were estimated using airborne concentration measurements and inferential models. Our observations reveal large spatial variations of atmospheric Nr concentrations and dry and wet/bulk Nr deposition. On a national basis, the annual average concentrations (1.3–47.0 μg N m−3) and dry plus wet/bulk deposition fluxes (2.9–83.3 kg N ha−1 yr−1) of inorganic Nr species are ranked by land use as urban > rural > background sites and by regions as north China > southeast China > southwest China > northeast China > northwest China > Tibetan Plateau, reflecting the impact of anthropogenic Nr emission. Average dry and wet/bulk N deposition fluxes were 20.6 ± 11.2 (mean ± standard deviation) and 19.3 ± 9.2 kg N ha−1 yr−1 across China, with reduced N deposition dominating both dry and wet/bulk deposition. Our results suggest atmospheric dry N deposition is equally important to wet/bulk N deposition at the national scale. Therefore, both deposition forms should be included when considering the impacts of N deposition on environment and ecosystem health.
Using a data sample of
e
+
e
−
collision data corresponding to an integrated luminosity of
19
fb
−
1
collected with the BESIII detector at the BEPCII collider, we search for the production of ...deuterons and antideuterons via
e
+
e
−
→
p
p
π
−
d
¯
+
c
.
c
.
for the first time at center-of-mass energies between 4.13 and 4.70 GeV. No significant signal is observed and the upper limit of the
e
+
e
−
→
p
p
π
−
d
¯
+
c
.
c
.
cross section is determined to be from 9.0 to 145 fb depending on the center-of-mass energy at the 90% confidence level.
Published by the American Physical Society
2024
Using data samples collected with the BESIII detector operating at the BEPCII storage ring, we measure the cross sections of the e + e − → π + π − D + D − process at center-of-mass energies from ...4.190 to 4.946 GeV with a partial reconstruction method. Resonance structures are seen and the cross section line shape can be described by the coherent sum of either two Breit-Wigner functions or a Breit-Wigner function and a phase space term. The mass and width of the resonance at about 4.4 GeV are determined to be (4371.6±2.5±9.2) MeV/c 2 and (167±4±29) MeV, respectively, which are in agreement with those of the ψ(4360) or Y(4390) state. The spin-3D-wave charmonium state X(3842) is searched for through the e + e − → π + π − X(3842) → π + π − D + D − process, and evidence with a significance of 4.2σ is found in the data samples with center-of-mass energies from 4.6 to 4.7 GeV.
Stem cells need to be protected from genotoxic and proteotoxic stress to maintain a healthy pool throughout life
. Little is known about the proteostasis mechanism that safeguards stem cells. Here we ...report endoplasmic reticulum-associated degradation (ERAD) as a protein quality checkpoint that controls the haematopoietic stem cell (HSC)-niche interaction and determines the fate of HSCs. The SEL1L-HRD1 complex, the most conserved branch of ERAD
, is highly expressed in HSCs. Deletion of Sel1l led to niche displacement of HSCs and a complete loss of HSC identity, and allowed highly efficient donor-HSC engraftment without irradiation. Mechanistic studies identified MPL, the master regulator of HSC identity
, as a bona fide ERAD substrate that became aggregated in the endoplasmic reticulum following ERAD deficiency. Restoration of MPL signalling with an agonist partially rescued the number and reconstitution capacity of Sel1l-deficient HSCs. Our study defines ERAD as an essential proteostasis mechanism to safeguard a healthy stem cell pool by regulating the stem cell-niche interaction.
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