59 research outputs found
Bi-collinear antiferromagnetic order in the tetragonal -FeTe
By the first-principles electronic structure calculations, we find that the
ground state of PbO-type tetragonal -FeTe is in a bi-collinear
antiferromagnetic state, in which the Fe local moments () are
ordered ferromagnetically along a diagonal direction and antiferromagnetically
along the other diagonal direction on the Fe square lattice. This bi-collinear
order results from the interplay among the nearest, next nearest, and next next
nearest neighbor superexchange interactions , , and , mediated
by Te -band. In contrast, the ground state of -FeSe is in the
collinear antiferromagnetic order, similar as in LaFeAsO and BaFeAs.Comment: 5 pages and 5 figure
Characterization of a DNA Aptamer for Ovarian Cancer Clinical Tissue Recognition and in Vivo Imaging
Backgrounds/Aims: Ovarian cancer is the most lethal gynaecologic malignancy and is difficult to detect early. The inefficient early diagnosis of ovarian cancer is the main contributor to its high mortality rate. Aptamers, as chemical antibodies, are single-stranded DNA or RNA oligonucleotides that target cells or molecules with high affinity. Methods: Binding ability of R13 was measured by flow cytometry analysis. Stability of R13 was tested in blood serum of an ovarian cancer patient. Internalization of R13 was verified by confocal microscope imaging. 80 cases ovarian cancer tissues, 10 cases normal ovary tissues in a microarray and 6 fallopian tube tissues were prepared for this study. R13’s target ability was further confirmed in vivo tumor models in NOD/SCID mice. Results: In this study, we found aptamer R13 bound to ovarian cancer cells with dissociation constants in the nanomolar range. Moreover, these results were further confirmed by tissue imaging. Next we demonstrated that the targets of R13 are membrane proteins and that its internalization occurs in a caveolae-mediated and clathrin-mediated manner. The target function of R13 was determined by imaging A2780 tumours in mouse models. Conclusion: These findings suggest that R13 is a promising novel tool to diagnose and deliver drugs to treat ovarian cancer
Pairing symmetry and properties of iron-based high temperature superconductors
Pairing symmetry is important to indentify the pairing mechanism. The
analysis becomes particularly timely and important for the newly discovered
iron-based multi-orbital superconductors. From group theory point of view we
classified all pairing matrices (in the orbital space) that carry irreducible
representations of the system. The quasiparticle gap falls into three
categories: full, nodal and gapless. The nodal-gap states show conventional
Volovik effect even for on-site pairing. The gapless states are odd in orbital
space, have a negative superfluid density and are therefore unstable. In
connection to experiments we proposed possible pairing states and implications
for the pairing mechanism.Comment: 4 pages, 1 table, 2 figures, polished versio
From Awe to Ecological Behavior: The Mediating Role of Connectedness to Nature
Awe is a self-transcendent emotion that can diminish one’s focus on the self and serves as an important motivator of commitment to social collectives. However, the influence of awe on ecological behavior is not clear. This study examines the relationships between people’s feeling of awe, their connectedness to nature, and ecological behavior. Three experiments tested the effect of awe on ecological behaviors including mediation tests. Compared with participants in the control condition, participants in the awe condition were more inclined to behave ecologically (Study 1 and 2) and reported a higher feeling of connectedness to nature (Study 2). Moreover, the relationship between awe and ecological behavior was mediated by connectedness to nature (Study 3). These findings indicate that awe helps broaden the self-concept by including nature and increase connectedness to nature, which in turn lead to ecological behavior. They also highlight the significance of connectedness in explaining why awe increases ecological behavior
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Electrical generation and methane emission from an anoxic riverine sediment slurry treated by a two-chamber microbial fuel cell.
A two-chamber slurry microbial fuel cell (SMFC) was constructed using black-odorous river sediments as substrate for the anode. We tested addition of potassium ferricyanide (K3[Fe(CN)6]) or sodium chloride (NaCl) to the cathode chamber (0, 50, 100, 150, and 200 mM) and aeration of the cathode chamber (0, 2, 4, 6, and 8 h per day) to assess their response on electrical generation, internal resistance, and methane emission over a 600-h period. When the aeration time in the cathode chamber was 6 h and K3[Fe(CN)6] or NaCl concentrations were 200 mM, the highest power densities were 6.00, 6.45, and 6.64 mW·m-2, respectively. With increasing K3[Fe(CN)6] or NaCl concentration in the cathode chamber, methane emission progressively decreased (mean ± SD: 181.6 ± 10.9 → 75.5 ± 9.8 mg/m3·h and 428.0 ± 28.5 → 157.0 ± 35.7 mg/m3·h), respectively, but was higher than the reference having no cathode/anode electrodes (~ 30 mg/m3·h). Cathode aeration (0 → 8 h/day) demonstrated a reduction in methane emission from the anode chamber for only the 6-h treatment (mean: 349.6 ± 37.4 versus 299.4 ± 34.7 mg/m3·h for 6 h/day treatment); methane emission from the reference was much lower (85.3 ± 26.1 mg/m3·h). Our results demonstrate that adding an electron acceptor (K3[Fe(CN)6]), electrolyte solution (NaCl), and aeration to the cathode chamber can appreciably improve electrical generation efficiency from the MFC. Notably, electrical generation stimulates methane emission, but methane emission decreases at higher power densities
Associations between the Epithelial-Mesenchymal Transition Phenotypes of Circulating Tumor Cells and the Clinicopathological Features of Patients with Colorectal Cancer
In this study, we identified CTCs using the previously reported CanPatrol CTC enrichment technique from peripheral blood samples of 126 patients with colorectal cancer (CRC) and found that CTCs could be classified into three subpopulations based on expression of epithelial cell adhesion molecule (EpCAM) (E-CTCs), the mesenchymal cell marker vimentin (M-CTCs), or both EpCAM and vimentin (biphenotypic E/M-CTCs). Circulating tumor microemboli (CTMs) were also identified in peripheral blood samples. Meanwhile, E-CTCs, M-CTCs, E/M-CTCs, and CTMs were detected in 76.98%, 42.06%, 56.35%, and 36.51% of the 126 patients, respectively. Interestingly, the presence of CTMs and each CTC subpopulation was significantly associated with blood lymphocyte counts and tumor-node-metastasis stage (P<0.001). Lymphocyte counts and the neutrophil-to-lymphocyte ratio (NLR) in patients lacking CTCs were significantly different from those in patients testing positive for CTMs and each CTC subpopulation (P<0.001). Our results indicate that tumor metastasis is more significantly associated with the presence of CTMs and M-CTCs than with other CTC subpopulations and suggest that EMT may be involved in CTC evasion of lymphocyte-mediated clearance
Maternal Supplementation with Ornithine Promotes Placental Angiogenesis and Improves Intestinal Development of Suckling Piglets
The blood vessels of the placenta are crucial for fetal growth. Here, lower vessel density and ornithine (Orn) content were observed in placentae for low-birth-weight fetuses versus normal-birth-weight fetuses at day 75 of gestation. Furthermore, the Orn content in placentae decreased from day 75 to 110 of gestation. To investigate the role of Orn in placental angiogenesis, 48 gilts (Bama pig) were allocated into four groups. The gilts in the control group were fed a basal diet (CON group), while those in the experimental groups were fed a basal diet supplemented with 0.05% Orn (0.05% Orn group), 0.10% Orn (0.10% Orn group), and 0.15% Orn (0.15% Orn group), respectively. The results showed that 0.15% Orn and 0.10% Orn groups exhibited increased birth weight of piglets compared with the CON group. Moreover, the 0.15% Orn group was higher than the CON group in the blood vessel densities of placenta. Mechanistically, Orn facilitated placental angiogenesis by regulating vascular endothelial growth factor-A (VEGF-A). Furthermore, maternal supplementation with 0.15% Orn during gestation increased the jejunal and ileal villi height and the concentrations of colonic propionate and butyrate in suckling piglets. Collectively, these results showed that maternal supplementation with Orn promotes placental angiogenesis and improves intestinal development of suckling piglets
Research on Temperature Characteristics of Pulse Laser Fuze Drive Circuit
The change in laser output power caused by the temperature change of the pulse laser fuze drive circuit directly affects the detection distance and accuracy. In order to achieve accurate distance determination of the pulse laser fuze, it is necessary to study the influence of temperature changes on the output characteristics of the pulse laser fuze drive circuit. In this paper, we study the changes in peak power caused by changes in component parameters such as resistors, capacitors, and laser diodes in the pulse laser drive circuit, which is caused by typical temperature gradients in the transient state. Based on Simulink software, a simulation model of pulsed laser drive circuit is built, and based on the theory of RLC loop equation and laser rate equation, the temperature-dependent gain coefficients are introduced to obtain the laser output characteristics corresponding to typical temperature. As a main result, we found that the laser output power decreases by about 10% during the temperature change from -50°C to 50°C. A hardware test platform is built to verify that the error is no more than 1%. The above study provides a reliable method for the design of the temperature model of the pulsed laser fuze drive circuit
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