438 research outputs found
Atomic-scale combination of germanium-zinc nanofibers for structural and electrochemical evolution
Alloys are recently receiving considerable attention in the community of rechargeable batteries as possible alternatives to carbonaceous negative electrodes; however, challenges remain for the practical utilization of these materials. Herein, we report the synthesis of germanium-zinc alloy nanofibers through electrospinning and a subsequent calcination step. Evidenced by in situ transmission electron microscopy and electrochemical impedance spectroscopy characterizations, this one-dimensional design possesses unique structures. Both germanium and zinc atoms are homogenously distributed allowing for outstanding electronic conductivity and high available capacity for lithium storage. The as-prepared materials present high rate capability (capacity of similar to 50% at 20 C compared to that at 0.2 C-rate) and cycle retention (73% at 3.0 C-rate) with a retaining capacity of 546 mAh g(-1) even after 1000 cycles. When assembled in a full cell, high energy density can be maintained during 400 cycles, which indicates that the current material has the potential to be used in a large-scale energy storage system
Effect of 1,25-(OH)2D3 on proliferation of fibroblast-like synoviocytes and expressions of pro-inflammatory cytokines through regulating MicroRNA-22 in a rat model of rheumatoid arthritis
Objective: This study aims to investigate the regulatory mechanism of 1,25-(OH)2D3 on the proliferation of fibroblast-like synoviocytes (FLS) and expressions of pro-inflammatory cytokines in rheumatoid arthritis (RA) rats via microRNA-22 (miR-22).Methods: A rat model of RA was established with a subcutaneous injection of type II collagen. After treated with different concentrations of 1,25-(OH)2D3 the proliferation of FLS was estimated by the MTT method, and the optimal concentration of 1,25-(OH)2D3 was selected for further experiments. Cell proliferation was detected by MTT. Cell cycle and apoptosis were analyzed by FCM. The IL-1β, IL-6, IL-8, and PGE2 protein expressions were determined by ELISA, and MMP-3, INOS, and Cox-2 mRNA expressions were measured by qRT-PCR.Results: The rat model of RA was successfully established. Compared with the blank group, the 1,25-(OH)2D3 and miR-22 inhibitors groups exhibited higher proliferation inhibition and apoptosis rates, lower levels of pro-inflammatory cytokines (IL-1β, IL-6, IL-8, and PGE2), and decreased mRNA expressions of MMP-3, INOS, and Cox-2. The miR-22 mimics group had lower proliferation inhibition and apoptosis rates, elevated expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 than the blank group. In contrast to the 1,25-(OH)2D3 group, the proliferation inhibition and apoptosis rates were down-regulated, and the expressions of pro-inflammatory cytokines and MMP-3, INOS, and Cox-2 were up-regulated in the 1,25-(OH)2D3 + miR-22 mimics group.Conclusion: Our study demonstrated that 1,25-(OH)2D3 inhibits the proliferation of FLS and alleviates inflammatory response in RA rats by down-regulating miR-22
Observation of a ppb mass threshoud enhancement in \psi^\prime\to\pi^+\pi^-J/\psi(J/\psi\to\gamma p\bar{p}) decay
The decay channel
is studied using a sample of events collected
by the BESIII experiment at BEPCII. A strong enhancement at threshold is
observed in the invariant mass spectrum. The enhancement can be fit
with an -wave Breit-Wigner resonance function with a resulting peak mass of
and a
narrow width that is at the 90% confidence level.
These results are consistent with published BESII results. These mass and width
values do not match with those of any known meson resonance.Comment: 5 pages, 3 figures, submitted to Chinese Physics
PRELIMINARY REPORT ON THE PUTATIVE ASSOCIATION OF IL10 -3575 T/A GENETIC POLYMORPHISM WITH MALARIA SYMPTOMS
Only a small percentage of individuals living in endemic areas develop severe malaria suggesting that host genetic factors may play a key role. This study has determined the frequency of single nucleotide polymorphisms (SNPs) in some pro and anti-inflammatory cytokine gene sequences: IL6 (-174; rs1800795), IL12p40 (+1188; rs3212227), IL4 (+33; rs2070874), IL10 (-3575; rs1800890) and TGFb1 (+869; rs1800470), by means of PCR-RFLP. Blood samples were collected from 104 symptomatic and 37 asymptomatic subjects. Laboratory diagnosis was assessed by the thick blood smear test and nested-PCR. No association was found between IL6 (-174), IL12p40 (+1188), IL4 (+33), IL10 (- 3575), TGFb1 (+869) SNPs and malaria symptoms. However, regarding the IL10 -3575 T/A SNP, there were significantly more AA and AT subjects, carrying the polymorphic allele A, in the symptomatic group (c2 = 4.54, p = 0.01, OR = 0.40 [95% CI - 0.17- 0.94]). When the analysis was performed by allele, the frequency of the polymorphic allele A was also significantly higher in the symptomatic group (c2 = 4.50, p = 0.01, OR = 0.45 [95% CI - 0.21-0.95]). In conclusion, this study has suggested the possibility that the IL10 - 3575 T/A SNP might be associated with the presence and maintenance of malaria symptoms in individuals living in endemic areas. Taking into account that this polymorphism is related to decreased IL10 production, a possible role of this SNP in the pathophysiology of malaria is also suggested, but replication studies with a higher number of patients and evaluation of IL10 levels are needed for confirmation
In vivo and in vitro assessment of pathways involved in contrast media-induced renal cells apoptosis
Contrast-induced nephropathy accounts for >10% of all causes of hospital-acquired renal failure, causes a prolonged in-hospital stay and represents a powerful predictor of poor early and late outcome. Mechanisms of contrast-induced nephropathy are not completely understood. In vitro data suggests that contrast media (CM) induces a direct toxic effect on renal tubular cells through the activation of the intrinsic apoptotic pathway. It is unclear whether this effect has a role in the clinical setting. In this work, we evaluated the effects of CM both in vivo and in vitro. By analyzing urine samples obtained from patients who experienced contrast-induced acute kidney injury (CI-AKI), we verified, by western blot and immunohistochemistry, that CM induces tubular renal cells apoptosis. Furthermore, in cultured cells, CM caused a dose–response increase in reactive oxygen species (ROS) production, which triggered Jun N-terminal kinases (JNK1/2) and p38 stress kinases marked activation and thus apoptosis. Inhibition of JNK1/2 and p38 by different approaches (i.e. pharmacological antagonists and transfection of kinase-death mutants of the upstream p38 and JNK kinases) prevented CM-induced apoptosis. Interestingly, N-acetylcysteine inhibited ROS production, and thus stress kinases and apoptosis activation. Therefore, we conclude that CM-induced tubular renal cells apoptosis represents a key mechanism of CI-AKI
Inhibition of STAT3 signaling as critical molecular event in resveratrol-suppressed ovarian cancer cells
Electronic structure of the iron-based superconductor LaOFeP
The recent discovery of superconductivity in the so-called iron-oxypnictide
family of compounds has generated intense interest. The layered crystal
structure with transition metal ions in planar square lattice form and the
discovery of spin-density-wave order near 130 K seem to hint at a strong
similarity with the copper oxide superconductors. A burning current issue is
the nature of the ground state of the parent compounds. Two distinct classes of
theories have been put forward depending on the underlying band structures:
local moment antiferromagnetic ground state for strong coupling approach and
itinerant ground state for weak coupling approach. The local moment magnetism
approach stresses on-site correlations and proximity to a Mott insulating state
and thus the resemblance to cuprates; while the latter approach emphasizes the
itinerant electron physics and the interplay between the competing
ferromagnetic and antiferromagnetic fluctuations. Such a controversy is partly
due to the lack of conclusive experimental information on the electronic
structures. Here we report the first angle-resolved photoemission spectroscopy
(ARPES) investigation of LaOFeP (Tc = 5.9 K), the first reported iron-based
superconductor. Our results favor the itinerant ground state, albeit with band
renormalization. In addition, our data reveal important differences between
these and copper based superconductors.Comment: 17 pages, 4 figure
Caveolin-1-Enhanced Motility and Focal Adhesion Turnover Require Tyrosine-14 but Not Accumulation to the Rear in Metastatic Cancer Cells
Caveolin-1 is known to promote cell migration, and increased caveolin-1 expression is associated with tumor progression and metastasis. In fibroblasts, caveolin-1 polarization and phosphorylation of tyrosine-14 are essential to promote migration. However, the role of caveolin-1 in migration of metastatic cells remains poorly defined. Here, caveolin-1 participation in metastatic cell migration was evaluated by shRNA targeting of endogenous caveolin-1 in MDA-MB-231 human breast cancer cells and ectopic expression in B16-F10 mouse melanoma cells. Depletion of caveolin-1 in MDA-MB-231 cells reduced, while expression in B16-F10 cells promoted migration, polarization and focal adhesion turnover in a sequence of events that involved phosphorylation of tyrosine-14 and Rac-1 activation. In B16-F10 cells, expression of a non-phosphorylatable tyrosine-14 to phenylalanine mutant failed to recapitulate the effects observed with wild-type caveolin-1. Alternatively, treatment of MDA-MB-231 cells with the Src family kinase inhibitor PP2 reduced caveolin-1 phosphorylation on tyrosine-14 and cell migration. Surprisingly, unlike for fibroblasts, caveolin-1 polarization and re-localization to the trailing edge were not observed in migrating metastatic cells. Thus, expression and phosphorylation, but not polarization of caveolin-1 favor the highly mobile phenotype of metastatic cells
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