6,120 research outputs found
Universal conductance fluctuations in indium tin oxide nanowires
Magnetic field dependent universal conductance fluctuations (UCF's) are
observed in weakly disordered indium tin oxide nanowires from 0.26 K up to
K. The fluctuation magnitudes increase with decreasing temperature,
reaching a fraction of at K. The shape of the UCF
patterns is found to be very sensitive to thermal cycling of the sample to room
temperatures, which induces irreversible impurity reconfigurations. On the
other hand, the UCF magnitudes are insensitive to thermal cycling. Our measured
temperature dependence of the root-mean-square UCF magnitudes are compared with
the existing theory [C. W. J. Beenakker and H. van Houten, Phys. Rev. B
\textbf{37}, 6544 (1988)]. A notable discrepancy is found, which seems to imply
that the experimental UCF's are not cut off by the thermal diffusion length
, as would be expected by the theoretical prediction when , where is the electron dephasing length. The approximate
electron dephasing length is inferred from the UCF magnitudes and compared with
that extracted from the weak-localization magnetoresistance studies. A
reasonable semiquantitative agreement is observed.Comment: 11 pages, 9 figure
Enhanced Antifungal Bioactivity of Coptis Rhizome Prepared by Ultrafining Technology
The aim of this study was to identify and quantify the bioactive constituents in the methanol extracts of Coptis Rhizome prepared by ultrafining technology. The indicator compound was identified by spectroscopic method and its purity was determined by HPLC. Moreover, the crude extracts and indicator compound were examined for their ability to inhibit the growth of Rhizoctonia solani Kühn AG-4 on potato dextrose agar plates. The indicator compound is a potential candidate as a new plant derived pesticide to control Rhizoctonia damping-off in vegetable seedlings. In addition, the extracts of Coptis Rhizome prepared by ultrafining technology displayed higher contents of indicator compound; they not only improve their bioactivity but also reduce the amount of the pharmaceuticals required and, thereby, decrease the environmental degradation associated with the harvesting of the raw products
Breakpoints and deleted genes identification of ring chromosome 18 in a Chinese girl by whole-genome low-coverage sequencing: a case report study
The serological examination results. (DOCX 13 kb
Probing Primordial Gravitational Waves: Ali CMB Polarization Telescope
In this paper, we will give a general introduction to the project of Ali CMB
Polarization Telescope (AliCPT), which is a Sino-US joint project led by the
Institute of High Energy Physics (IHEP) and has involved many different
institutes in China. It is the first ground-based Cosmic Microwave Background
(CMB) polarization experiment in China and an integral part of China's
Gravitational Waves Program. The main scientific goal of AliCPT project is to
probe the primordial gravitational waves (PGWs) originated from the very early
Universe.
The AliCPT project includes two stages. The first stage referred to as
AliCPT-1, is to build a telescope in the Ali region of Tibet with an altitude
of 5,250 meters. Once completed, it will be the worldwide highest ground-based
CMB observatory and open a new window for probing PGWs in northern hemisphere.
AliCPT-1 telescope is designed to have about 7,000 TES detectors at 90GHz and
150GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with
the number of detectors more than 20,000.
Our simulations show that AliCPT will improve the current constraint on the
tensor-to-scalar ratio by one order of magnitude with 3 years' observation.
Besides the PGWs, the AliCPT will also enable a precise measurement on the CMB
rotation angle and provide a precise test on the CPT symmetry. We show 3 years'
observation will improve the current limit by two order of magnitude.Comment: 11 pages, 7 figures, 2 table
Lentivirus-mediated RNA interference targeting the H19 gene inhibits cell proliferation and apoptosis in human choriocarcinoma cell line JAR
BACKGROUND: H19 is a paternally imprinted gene that has been shown to be highly expressed in the trophoblast tissue. Results from previous studies have initiated a debate as to whether noncoding RNA H19 acts as a tumor suppressor or as a tumor promotor in trophoblast tissue. In the present study, we developed lentiviral vectors expressing H19-specific small interfering RNA (siRNA) to specifically block the expression of H19 in the human choriocarcinoma cell line JAR. Using this approach, we investigated the impact of the H19 gene on the proliferation, invasion and apoptosis of JAR cells. Moreover, we examined the effect of H19 knockdown on the expression of insulin-like growth factor 2 (IGF2), hairy and enhancer of split homologue-1 (HES-1) and dual-specific phosphatase 5 (DUSP5) genes. RESULTS: H19 knockdown inhibited apoptosis and proliferation of JAR cells, but had no significant impact on cell invasion. In addition, H19 knockdown resulted in significant upregulation of HES-1 and DUSP5 expression, but not IGF2 expression in JAR cells. CONCLUSIONS: The finding that H19 downregulation could simultaneously inhibit proliferation and apoptosis of JAR cells highlights a putative dual function for H19 in choriocarcinoma and may explain the debate on whether H19 acts as a tumor suppressor or a tumor promotor in trophoblast tissue. Furthermore, upregulation of HES-1 and DUSP5 may mediate H19 downregulation-induced suppression of proliferation and apoptosis of JAR cells
Finite-Time Boundedness of Impulsive Delayed Reaction–Diffusion Stochastic Neural Networks
Considering the impulsive delayed reaction&#x2013;diffusion stochastic neural networks (IDRDSNNs) with hybrid impulses, the finite-time boundedness (FTB) and finite-time contractive boundedness (FTCB) are investigated in this article. First, a novel delay integral inequality is presented. By integrating this inequality with the comparison principle, some sufficient conditions that ensure the FTB and FTCB of IDRDSNNs are obtained. This study demonstrates that the FTB of neural networks with hybrid impulses can be maintained, even in the presence of impulsive perturbations. And for a system that is not FTB due to impulsive perturbations, achieving FTB is possible through the implementation of appropriate impulsive control and optimization of the average impulsive intervals. In addition, to validate the practicality of our results, three illustrative examples are provided. In the end, these theoretical findings are successfully applied to image encryption.</p
Finite-Time Boundedness of Impulsive Delayed Reaction–Diffusion Stochastic Neural Networks
Considering the impulsive delayed reaction&#x2013;diffusion stochastic neural networks (IDRDSNNs) with hybrid impulses, the finite-time boundedness (FTB) and finite-time contractive boundedness (FTCB) are investigated in this article. First, a novel delay integral inequality is presented. By integrating this inequality with the comparison principle, some sufficient conditions that ensure the FTB and FTCB of IDRDSNNs are obtained. This study demonstrates that the FTB of neural networks with hybrid impulses can be maintained, even in the presence of impulsive perturbations. And for a system that is not FTB due to impulsive perturbations, achieving FTB is possible through the implementation of appropriate impulsive control and optimization of the average impulsive intervals. In addition, to validate the practicality of our results, three illustrative examples are provided. In the end, these theoretical findings are successfully applied to image encryption.</p
- …
