116 research outputs found
Microwave plasma-assisted photoluminescence enhancement in nitrogendoped ultrananocrystalline diamond film
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Nanoparticles prepared from the water extract of Gusuibu (Drynaria fortunei J. Sm.) protects osteoblasts against insults and promotes cell maturation
Our previous study showed that Gusuibu (Drynaria fortunei J. Sm.) can stimulate osteoblast maturation. This study was further designed to evaluate the effects of nanoparticles prepared from the water extract of Gusuibu (WEG) on osteoblast survival and maturation. Primary osteoblasts were exposed to 1, 10, 100, and 1000 μg/mL nanoparticles of WEG (nWEG) for 24, 48, and 72 hours did not affect morphologies, viability, or apoptosis of osteoblasts. In comparison, treatment of osteoblasts with 1000 μg/mL WEG for 72 hours decreased cell viability and induced DNA fragmentation and cell apoptosis. nWEG had better antioxidant bioactivity in protecting osteoblasts from oxidative and nitrosative stress-induced apoptosis than WEG. In addition, nWEG stimulated greater osteoblast maturation than did WEG. Therefore, this study shows that WEG nanoparticles are safer to primary osteoblasts than are normal-sized products, and may promote better bone healing by protecting osteoblasts from apoptotic insults, and by promoting osteogenic maturation
A Novel RFID Sensing System Using Enhanced Surface Wave Technology for Battery Exchange Stations
This paper presents a novel radio-frequency identification (RFID) sensing system using enhanced surface wave technology for battery exchange stations (BESs) of electric motorcycles. Ultrahigh-frequency (UHF) RFID technology is utilized to automatically track and manage battery and user information without manual operation. The system includes readers, enhanced surface wave leaky cable antennas (ESWLCAs), coupling cable lines (CCLs), and small radiation patches (SRPs). The RFID sensing system overcomes the electromagnetic interference in the metallic environment of a BES cabinet. The developed RFID sensing system can effectively increase the efficiency of BES operation and promote the development of electric vehicles which solve the problem of air pollution as well as protect the environment of the Earth
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Dual Supramolecular Nanoparticle Vectors Enable CRISPR/Cas9-Mediated Knockin of Retinoschisin 1 Gene-A Potential Nonviral Therapeutic Solution for X-Linked Juvenile Retinoschisis.
The homology-independent targeted integration (HITI) strategy enables effective CRISPR/Cas9-mediated knockin of therapeutic genes in nondividing cells in vivo, promising general therapeutic solutions for treating genetic diseases like X-linked juvenile retinoschisis. Herein, supramolecular nanoparticle (SMNP) vectors are used for codelivery of two DNA plasmids-CRISPR-Cas9 genome-editing system and a therapeutic gene, Retinoschisin 1 (RS1)-enabling clustered regularly interspaced short palindromic repeats (CRISPR)-associated protein 9 (CRISPR/Cas9) knockin of the RS1 gene with HITI. Through small-scale combinatorial screenings, two SMNP vectors, with Cas9 and single guide RNA (sgRNA)-plasmid in one and Donor-RS1 and green fluorescent protein (GFP)-plasmid in the other, with optimal delivery performances are identified. These SMNP vectors are then employed for CRISPR/Cas9 knockin of RS1/GFP genes into the mouse Rosa26 safe-harbor site in vitro and in vivo. The in vivo study involves intravitreally injecting the two SMNP vectors into the mouse eyes, followed by repeated ocular imaging by fundus camera and optical coherence tomography, and pathological and molecular analyses of the harvested retina tissues. Mice ocular organs retain their anatomical integrity, a single-copy 3.0-kb RS1/GFP gene is precisely integrated into the Rosa26 site in the retinas, and the integrated RS1/GFP gene is expressed in the retinas, demonstrating CRISPR/Cas9 knockin of RS1/GFP gene
Gene Transfer of Pro-opiomelanocortin Prohormone Suppressed the Growth and Metastasis of Melanoma: Involvement of ␣-Melanocyte-Stimulating Hormone-Mediated Inhibition of the Nuclear Factor B/Cyclooxygenase-2 Pathway
ABSTRACT Pro-opiomelanocortin (POMC) is a prohormone of various neuropeptides, including corticotropin, ␣-melanocyte-stimulating hormone (␣-MSH), and -endorphin (-EP) . POMC neuropeptides are potent inflammation inhibitors and immunosuppressants and may exert opposite influences during tumorigenesis. However, the role of POMC expression in carcinogenesis remains elusive. We evaluated the antineoplastic potential of POMC gene delivery in a syngenic B16-F10 melanoma model. Adenovirus-mediated POMC gene delivery in B16-F10 cells increased the release of POMC neuropeptides in cultured media, which differentially regulated the secretion of pro-and anti-inflammatory cytokines in lymphocytes. POMC gene transfer significantly reduced the anchorage-independent growth of melanoma cells. Moreover, pre-or post-treatment with POMC gene delivery effectively retarded the melanoma growth in mice. Intravenous injection of POMC-transduced B16-F10 cells resulted in reduced foci formation in lung by 60 to 70% of control. The reduced metastasis of POMC-transduced B16-F10 cells could be attributed to their attenuated migratory and adhesive capabilities. POMC gene delivery reduced the cyclooxygenase-2 (COX-2) expression and prostaglandin (PG) E 2 synthesis in melanoma cells and tumor tissues. In addition, application of NS-398, a selective COX-2 inhibitor, mimicked the antineoplastic functions of POMC gene transfer in melanoma. The POMC-mediated COX-2 down-regulation was correlated with its inhibition of nuclear factor B (NFB) activities. Exogenous supply of ␣-MSH inhibited NFB activities, whereas application of the ␣-MSH antagonist growth hormone-releasing peptide-6 (GHRP-6) abolished the POMC-induced inhibition of NFB activities and melanoma growth in mice. In summary, POMC gene delivery suppresses melanoma via ␣-MSH-induced inhibition of NFB/COX-2 pathway, thereby constituting a novel therapy for melanoma. POMC is a multifunctional polycistronic gene located on human chromosome 2p23.3. POMC is a 31 kDa prohormone that is processed into various neuropeptides, including corticotropin, melanotropins (␣-, -, and ␥-MSH), lipotropins, and -endorphin (-EP
In situ detection of dopamine using nitrogen incorporated diamond nanowire electrode
[[abstract]]Significant difference was observed for the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA) mixture using nitrogen incorporated diamond nanowire (DNW) film electrodes grown by microwave plasma enhanced chemical vapor deposition. For the simultaneous sensing of ternary mixtures of DA, AA, and UA, well-separated voltammetric peaks are obtained using DNW film electrodes in differential pulse voltammetry (DPV) measurements. Remarkable signals in cyclic voltammetry responses to DA, AA and UA (three well defined voltammetric peaks at potentials around 235, 30, 367 mV for DA, AA and UA respectively) and prominent enhancement of the voltammetric sensitivity are observed at the DNW electrodes. In comparison to the DPV results of graphite, glassy carbon and boron doped diamond electrodes, the high electrochemical potential difference is achieved via the use of the DNW film electrodes which is essential for distinguishing the aforementioned analytes. The enhancement in EC properties is accounted for by increase in sp2 content, new C–N bonds at the diamond grains, and increase in the electrical conductivity at the grain boundary, as revealed by X-ray photoelectron spectroscopy and near edge X-ray absorption fine structure measurements. Consequently, the DNW film electrodes provide a clear and efficient way for the selective detection of DA in the presence of AA and UA.[[booktype]]紙
Experimental and Theoretical Challenges in the Search for the Quark Gluon Plasma: The STAR Collaboration's Critical Assessment of the Evidence from RHIC Collisions
We review the most important experimental results from the first three years
of nucleus-nucleus collision studies at RHIC, with emphasis on results from the
STAR experiment, and we assess their interpretation and comparison to theory.
The theory-experiment comparison suggests that central Au+Au collisions at RHIC
produce dense, rapidly thermalizing matter characterized by: (1) initial energy
densities above the critical values predicted by lattice QCD for establishment
of a Quark-Gluon Plasma (QGP); (2) nearly ideal fluid flow, marked by
constituent interactions of very short mean free path, established most
probably at a stage preceding hadron formation; and (3) opacity to jets. Many
of the observations are consistent with models incorporating QGP formation in
the early collision stages, and have not found ready explanation in a hadronic
framework. However, the measurements themselves do not yet establish
unequivocal evidence for a transition to this new form of matter. The
theoretical treatment of the collision evolution, despite impressive successes,
invokes a suite of distinct models, degrees of freedom and assumptions of as
yet unknown quantitative consequence. We pose a set of important open
questions, and suggest additional measurements, at least some of which should
be addressed in order to establish a compelling basis to conclude definitively
that thermalized, deconfined quark-gluon matter has been produced at RHIC.Comment: 101 pages, 37 figures; revised version to Nucl. Phys.
Phi meson production in Au+Au and p+p collisions at sqrt (s)=200 GeV
We report the STAR measurement of Phi meson production in Au+Au and p+p
collisions at sqrt (s)=200 GeV. Using the event mixing technique, the Phi
spectra and yields are obtained at mid-rapidity for five centrality bins in
Au+Au collisions and for non-singly-diffractive p+p collisions. It is found
that the Phi transverse momentum distributions from Au+Au collisions are better
fitted with a single-exponential while the p+p spectrum is better described by
a double-exponential distribution. The measured nuclear modification factors
indicate that Phi production in central Au+Au collisions is suppressed relative
to peripheral collisions when scaled by the number of binary collisions. The
systematics of versus centrality and the constant Phi/K- ratio versus beam
species, centrality, and collision energy rule out kaon coalescence as the
dominant mechanism for Phi production.Comment: 6 pages, 3 figures, submitted to Phys. Rev. Let
The cell biology of vision
Humans possess the remarkable ability to perceive color, shape, and motion, and to differentiate between light intensities varied by over nine orders of magnitude. Phototransduction—the process in which absorbed photons are converted into electrical responses—is the first stage of visual processing, and occurs in the outer segment, the light-sensing organelle of the photoreceptor cell. Studies of genes linked to human inherited blindness have been crucial to understanding the biogenesis of the outer segment and membrane-trafficking of photoreceptors
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