2,392 research outputs found
Combination of Electroacupuncture and Grafted Mesenchymal Stem Cells Overexpressing TrkC Improves Remyelination and Function in Demyelinated Spinal Cord of Rats
10.1038/srep09133Scientific Reports
Electron interaction-driven insulating ground state in Bi2Se3 topological insulators in the two dimensional limit
We report a transport study of ultrathin Bi2Se3 topological insulators with
thickness from one quintuple layer to six quintuple layers grown by molecular
beam epitaxy. At low temperatures, the film resistance increases
logarithmically with decreasing temperature, revealing an insulating ground
state. The sharp increase of resistance with magnetic field, however, indicates
the existence of weak antilocalization, which should reduce the resistance as
temperature decreases. We show that these apparently contradictory behaviors
can be understood by considering the electron interaction effect, which plays a
crucial role in determining the electronic ground state of topological
insulators in the two dimensional limit.Comment: 4 figure
Nitric oxide-induced lipophagic defects contribute to testosterone deficiency in rats with spinal cord injury
IntroductionMales with acute spinal cord injury (SCI) frequently exhibit testosterone deficiency and reproductive dysfunction. While such incidence rates are high in chronic patients, the underlying mechanisms remain elusive.Methods and resultsHerein, we generated a rat SCI model, which recapitulated complications in human males, including low testosterone levels and spermatogenic disorders. Proteomics analyses showed that the differentially expressed proteins were mostly enriched in lipid metabolism and steroid metabolism and biosynthesis. In SCI rats, we observed that testicular nitric oxide (NO) levels were elevated and lipid droplet-autophagosome co-localization in testicular interstitial cells was decreased. We hypothesized that NO impaired lipophagy in Leydig cells (LCs) to disrupt testosterone biosynthesis and spermatogenesis. As postulated, exogenous NO donor (S-nitroso-N-acetylpenicillamine (SNAP)) treatment markedly raised NO levels and disturbed lipophagy via the AMPK/mTOR/ULK1 pathway, and ultimately impaired testosterone production in mouse LCs. However, such alterations were not fully observed when cells were treated with an endogenous NO donor (L-arginine), suggesting that mouse LCs were devoid of an endogenous NO-production system. Alternatively, activated (M1) macrophages were predominant NO sources, as inducible NO synthase inhibition attenuated lipophagic defects and testosterone insufficiency in LCs in a macrophage-LC co-culture system. In scavenging NO (2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (CPTIO)) we effectively restored lipophagy and testosterone levels both in vitro and in vivo, and importantly, spermatogenesis in vivo. Autophagy activation by LYN-1604 also promoted lipid degradation and testosterone synthesis.DiscussionIn summary, we showed that NO-disrupted-lipophagy caused testosterone deficiency following SCI, and NO clearance or autophagy activation could be effective in preventing reproductive dysfunction in males with SCI
The CDEX-1 1 kg Point-Contact Germanium Detector for Low Mass Dark Matter Searches
The CDEX Collaboration has been established for direct detection of light
dark matter particles, using ultra-low energy threshold p-type point-contact
germanium detectors, in China JinPing underground Laboratory (CJPL). The first
1 kg point-contact germanium detector with a sub-keV energy threshold has been
tested in a passive shielding system located in CJPL. The outputs from both the
point-contact p+ electrode and the outside n+ electrode make it possible to
scan the lower energy range of less than 1 keV and at the same time to detect
the higher energy range up to 3 MeV. The outputs from both p+ and n+ electrode
may also provide a more powerful method for signal discrimination for dark
matter experiment. Some key parameters, including energy resolution, dead time,
decay times of internal X-rays, and system stability, have been tested and
measured. The results show that the 1 kg point-contact germanium detector,
together with its shielding system and electronics, can run smoothly with good
performances. This detector system will be deployed for dark matter search
experiments.Comment: 6 pages, 8 figure
An agonist sensitive, quick and simple cell-based signaling assay for determination of ligands mimicking prostaglandin E2 or E1 activity through subtype EP1 receptor: Suitable for high throughput screening
<p>Abstract</p> <p>Background</p> <p>Conventionally the active ingredients in herbal extracts are separated into individual components, by fractionation, desalting, and followed by high-performance liquid chromatography (HPLC). In this study we have tried to directly screen water-soluble fractions of herbs with potential active ingredients before purification or extraction. We propose that the herbal extracts mimicking prostaglandin E<sub>1 </sub>(PGE<sub>1</sub>) and E<sub>2 </sub>(PGE<sub>2</sub>) can be identified in the water-soluble non-purified fraction. PGE<sub>1 </sub>is a potent anti-inflammatory molecule used for treating peripheral vascular diseases while PGE<sub>2 </sub>is an inflammatory molecule.</p> <p>Methods</p> <p>We used cell-based assays (CytoFluor multi-well plate reader and fluorescence microscopy) in which a calcium signal was generated by the recombinant EP<sub>1 </sub>receptor stably expressed in HEK293 cells (human embryonic kidney). PGE<sub>1 </sub>and PGE<sub>2 </sub>were tested for their ability to generate a calcium signal. Ninety-six water soluble fractions of Treasures of the east (single Chinese herb dietary supplements) were screened.</p> <p>Results</p> <p>After screening, the top ten stimulators were identified. The identified herbs were then desalted and the calcium fluorescent signal reconfirmed using fluorescence microscopy. Among these top ten agonists identified, seven stimulated the calcium signaling (1-40 μM concentration) using fluorescence microscopy.</p> <p>Conclusions</p> <p>Fluorescence microscopy and multi-well plate readers can be used as a target specific method for screening water soluble fractions with active ingredients at a very early stage, before purification. Our future work consists of purifying and separating the active ingredients and repeating fluorescence microscopy. Under ordinary circumstances we would have to purify the compounds first and then test all the extracts from 96 herbs. Conventionally, for screening natural product libraries, the procedure followed is the automated separation of all constituents into individual components using fractionation and high performance liquid chromatography. We, however, demonstrated that the active ingredients of the herbal extracts can be tested before purification using an agonist sensitive, quick and simple cell-based signaling assay for ligands mimicking the agonists, PGE<sub>1 </sub>and PGE<sub>2</sub>.</p
Retrospective analysis of nosocomial infections in the intensive care unit of a tertiary hospital in China during 2003 and 2007
<p>Abstract</p> <p>Background</p> <p>Nosocomial infections are a major threat to patients in the intensive care unit (ICU). Limited data exist on the epidemiology of ICU-acquired infections in China. This retrospective study was carried out to determine the current status of nosocomial infection in China.</p> <p>Methods</p> <p>A retrospective review of nococomial infections in the ICU of a tertiary hospital in East China between 2003 and 2007 was performed. Nosocomial infections were defined according to the definitions of Centers for Disease Control and Prevention. The overall patient nosocomial infection rate, the incidence density rate of nosocomial infections, the excess length of stay, and distribution of nosocomial infection sites were determined. Then, pathogen and antimicrobial susceptibility profiles were further investigated.</p> <p>Results</p> <p>Among 1980 patients admitted over the period of time, the overall patient nosocomial infection rate was 26.8% or 51.0 per 1000 patient days., Lower respiratory tract infections (LRTI) accounted for most of the infections (68.4%), followed by urinary tract infections (UTI, 15.9%), bloodstream (BSI, 5.9%), and gastrointestinal tract (GI, 2.5%) infections. There was no significant change in LRTI, UTI and BSI infection rates during the 5 years. However, GI rate was significantly decreased from 5.5% in 2003 to 0.4% in 2007. In addition, <it>A. baumannii, C. albicans </it>and <it>S. epidermidis </it>were the most frequent pathogens isolated in patients with LRTIs, UTIs and BSIs, respectively. The rates of isolates resistant to commonly used antibiotics ranged from 24.0% to 93.1%.</p> <p>Conclusion</p> <p>There was a high and relatively stable rate of nosocomial infections in the ICU of a tertiary hospital in China through year 2003–2007, with some differences in the distribution of the infection sites, and pathogen and antibiotic susceptibility profiles from those reported from the Western countries. Guidelines for surveillance and prevention of nosocomial infections must be implemented in order to reduce the rate.</p
Evidence of a resonant structure in the cross section between 4.05 and 4.60 GeV
The cross section of the process for
center-of-mass energies from 4.05 to 4.60~GeV is measured precisely using data
samples collected with the BESIII detector operating at the BEPCII storage
ring.
Two enhancements are clearly visible in the cross section around 4.23 and
4.40~GeV.
Using several models to describe the dressed cross section yields stable
parameters for the first enhancement, which has a mass of 4228.6 \pm 4.1 \pm
6.3 \un{MeV}/c^2 and a width of 77.0 \pm 6.8 \pm 6.3 \un{MeV}, where the
first uncertainties are statistical and the second ones are systematic.
Our resonant mass is consistent with previous observations of the
state and the theoretical prediction of a molecule.
This result is the first observation of associated with an
open-charm final state.
Fits with three resonance functions with additional , ,
, , or a new resonance, do not show significant
contributions from either of these resonances. The second enhancement is not
from a single known resonance. It could contain contributions from
and other resonances, and a detailed amplitude analysis is required to better
understand this enhancement
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