27 research outputs found
In vitro evaluation of pan-PI3-kinase inhibitor SF1126 in trastuzumab-sensitive and trastuzumab-resistant HER2-over-expressing breast cancer cells
Stabilization of Fast Pyrolysis Liquids from Biomass by Mild Catalytic Hydrotreatment:Model Compound Study
Repolymerization is a huge problem in the storage and processing of biomass pyrolysis liquid (PL). Herein, to solve the problem of repolymerization, mild catalytic hydrotreatment of PL was conducted to convert unstable PL model compounds (hydroxyacetone, furfural, and phenol) into stable alcohols. An Ni/SiO2 catalyst was synthesized by the deposition-precipitation method and used in a mild hydrotreatment process. The mild hydrotreatment of the single model compound was studied to determine the reaction pathways, which provided guidance for improving the selectivity of stable intermediate alcohols through the control of reaction conditions. More importantly, the mild hydrotreatment of mixed model compounds was evaluated to simulate the PL more factually. In addition, the effect of the interaction between hydroxyacetone, furfural, and phenol during the catalytic hydrotreatment was also explored. There was a strange phenomenon observed in that phenol was not converted in the initial stage of the hydrotreatment of mixed model compounds. Thermogravimetric analysis (TGA), Ultraviolet-Raman (UV-Raman), and Brunauer−Emmett−Teller (BET) characterization of catalysts used in the hydrotreatment of single and mixed model compounds demonstrated that this phenomenon did not mainly arise from the irreversible deactivation of catalysts caused by carbon deposition, but the competitive adsorption among hydroxyacetone, furfural, and phenol during the mild hydrotreatment of mixed model compounds
Direct observation of topological surface states in the layered kagome lattice with broken time-reversal symmetry
Magnetic topological quantum materials display a diverse range of fascinating
physical properties which arise from their intrinsic magnetism and the breaking
of time-reversal symmetry. However, so far, few examples of intrinsic magnetic
topological materials have been confirmed experimentally, which significantly
hinder our comprehensive understanding of the abundant physical properties in
this system. The kagome lattices, which host diversity of electronic structure
signatures such as Dirac nodes, flat bands, and saddle points, provide an
alternative and promising platform for in-depth investigations into
correlations and band topology. In this article, drawing inspiration from the
stacking configuration of MnBiTe, we conceive and then synthesize a
high-quality single crystal EuTiBi, which is a unique natural
heterostructure consisting of both topological kagome layers and magnetic
interlayers. We investigate the electronic structure of EuTiBi and
uncover distinct features of anisotropic multiple Van Hove singularitie (VHS)
that might prevent Fermi surface nesting, leading to the absence of a charge
density wave (CDW). In addition, we identify the topological nontrivial surface
states that serve as connections between different saddle bands in the vicinity
of the Fermi level. Combined with calculations, we establish that, the
effective time-reversal symmetry S= play a crucial role in
the antiferromagnetic ground state of EuTiBi, which ensures the
stability of the topological surface states and gives rise to their intriguing
topological nature. Therefore, EuTiBi offers the rare opportunity to
investigate correlated topological states in magnetic kagome materials.Comment: 9 pages, 4 figure
Rapid screening of Salmonella enterica serovars Enteritidis, Hadar, Heidelberg and Typhimurium using a serologically-correlative allelotyping PCR targeting the O and H antigen alleles
<p>Abstract</p> <p>Background</p> <p>Classical <it>Salmonella </it>serotyping is an expensive and time consuming process that requires implementing a battery of O and H antisera to detect 2,541 different <it>Salmonella enterica </it>serovars. For these reasons, we developed a rapid multiplex polymerase chain reaction (PCR)-based typing scheme to screen for the prevalent <it>S. enterica </it>serovars Enteritidis, Hadar, Heidelberg, and Typhimurium.</p> <p>Results</p> <p>By analyzing the nucleotide sequences of the genes for O-antigen biosynthesis including <it>wb</it>a operon and the central variable regions of the H1 and H2 flagellin genes in <it>Salmonella</it>, designated PCR primers for four multiplex PCR reactions were used to detect and differentiate <it>Salmonella </it>serogroups A/D1, B, C1, C2, or E1; H1 antigen types i, g, m, r or z<sub>10</sub>; and H2 antigen complexes, I: 1,2; 1,5; 1,6; 1,7 or II: e,n,x; e,n,z<sub>15</sub>. Through the detection of these antigen gene allele combinations, we were able to distinguish among <it>S. enterica </it>serovars Enteritidis, Hadar, Heidelberg, and Typhimurium. The assays were useful in identifying <it>Salmonella </it>with O and H antigen gene alleles representing 43 distinct serovars. While the H2 multiplex could discriminate between unrelated H2 antigens, the PCR could not discern differences within the antigen complexes, 1,2; 1,5; 1,6; 1,7 or e,n,x; e,n,z<sub>15</sub>, requiring a final confirmatory PCR test in the final serovar reporting of <it>S. enterica</it>.</p> <p>Conclusion</p> <p>Multiplex PCR assays for detecting specific O and H antigen gene alleles can be a rapid and cost-effective alternative approach to classical serotyping for presumptive identification of <it>S. enterica </it>serovars Enteritidis, Hadar, Heidelberg, and Typhimurium.</p
Effects of different fertilization conditions and different geographical locations on the diversity and composition of the rhizosphere microbiota of Qingke (Hordeum vulgare L.) plants in different growth stages
IntroductionThe excessive use of chemical fertilizer causes increasing environmental and food security crisis. Organic fertilizer improves physical and biological activities of soil. Rhizosphere microbiota, which consist of highly diverse microorganisms, play an important role in soil quality. However, there is limited information about the effects of different fertilization conditions on the growth of Qingke plants and composition of the rhizosphere microbiota of the plants.MethodsIn this study, we characterized the rhizosphere microbiota of Qingke plants grown in three main Qingke-producing areas (Tibet, Qinghai, and Gansu). In each of the three areas, seven different fertilization conditions (m1–m7, m1: Unfertilized; m2: Farmer Practice; m3: 75% Farmer Practice; m4: 75% Farmer Practice +25% Organic manure; m5: 50% Farmer Practice; m6: 50% Farmer Practice +50% Organic manure; m7: 100% Organic manure) were applied. The growth and yields of the Qingke plants were also compared under the seven fertilization conditions.ResultsThere were significant differences in alpha diversity indices among the three areas. In each area, differences in fertilization conditions and differences in the growth stages of Qingke plants resulted in differences in the beta diversity of the rhizosphere microbiota. Meanwhile, in each area, fertilization conditions, soil depths, and the growth stages of Qingke plants significantly affected the relative abundance of the top 10 phyla and the top 20 bacterial genera. For most of microbial pairs established through network analysis, the significance of their correlations in each of the microbial co-occurrence networks of the three experimental sites was different. Moreover, in each of the three networks, there were significant differences in relative abundance and genera among most nodes (i.e., the genera Pseudonocardia, Skermanella, Pseudonocardia, Skermanella, Aridibacter, and Illumatobacter). The soil chemical properties (i.e., TN, TP, SOM, AN, AK, CEC, Ca, and K) were positively or negatively correlated with the relative abundance of the top 30 genera derived from the three main Qingke-producing areas (p < 0.05). Fertilization conditions markedly influenced the height of a Qingke plant, the number of spikes in a Qingke plant, the number of kernels in a spike, and the fresh weight of a Qingke plant. Considering the yield, the most effective fertilization conditions for Qingke is combining application 50% chemical fertilizer and 50% organic manure.ConclusionThe results of the present study can provide theoretical basis for practice of reducing the use of chemical fertilizer in agriculture
Photoemission Evidence of a Novel Charge Order in Kagome Metal FeGe
A charge order has been discovered to emerge deep into the antiferromagnetic
phase of the kagome metal FeGe. To study its origin, the evolution of the
low-lying electronic structure across the charge order phase transition is
investigated with angle-resolved photoemission spectroscopy. We do not find
signatures of nesting between Fermi surface sections or van-Hove singularities
in zero-frequency joint density of states, and there are no obvious energy gaps
at the Fermi level, which exclude the nesting mechanism for the charge order
formation in FeGe. However, two obvious changes in the band structure have been
detected, i.e., one electron-like band around the K point and another one
around the A point move upward in energy position when the charge order forms.
These features can be well reproduced by our density-functional theory
calculations, where the charge order is primarily driven by magnetic energy
saving via large dimerizations of a quarter of Ge1-sites (in the kagome plane)
along the c-axis. Our results provide strong support for this novel charge
order formation mechanism in FeGe, in contrast to the conventional nesting
mechanism.Comment: 6 pages, 4 figure
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FAK activation is required for IGF1R-mediated regulation of EMT, migration, and invasion in mesenchymal triple negative breast cancer cells
Triple negative breast cancer (TNBC) is a highly metastatic disease that currently lacks effective prevention and treatment strategies. The insulin-like growth factor 1 receptor (IGF1R) and focal adhesion kinase (FAK) signaling pathways function in numerous developmental processes, and alterations in both are linked with a number of common pathological diseases. Overexpression of IGF1R and FAK are closely associated with metastatic breast tumors. The present study investigated the interrelationship between IGF1R and FAK signaling in regulating the malignant properties of TNBC cells. Using small hairpin RNA (shRNA)-mediated IGF1R silencing methods, we showed that IGF1R is essential for sustaining mesenchymal morphologies of TNBC cells and modulates the expression of EMT-related markers. We further showed that IGF1R overexpression promotes migratory and invasive behaviors of TNBC cell lines. Most importantly, IGF1R-driven migration and invasion is predominantly mediated by FAK activation and can be suppressed using pharmacological inhibitors of FAK. Our findings in TNBC cells demonstrate a novel role of the IGF1R/FAK signaling pathway in regulating critical processes involved in the metastatic cascade. These results may improve the current understanding of the basic molecular mechanisms of TNBC metastasis and provide a strong rationale for co-targeting of IGF1R and FAK as therapy for mesenchymal TNBCs
Comparative Study of the Trajectories of Chinese International Students who Graduated from Japanese Universities and Australian Universities
Comparative Study of the Trajectories of Chinese International Students who Graduated from Japanese Universities and Australian Universities
Comparative Study of the Trajectories of Chinese International Students who Graduated from Japanese Universities and Australian Universities
identifier:oai:t2r2.star.titech.ac.jp:5067824