519 research outputs found

    Proteome analysis of human colorectal cancer tissue using 2-D DIGE and tandem mass spectrometry for identification of disease-related proteins

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    Laser capture microdissection and two-dimensional difference gel electrophoresis were used to establish the proteomic profiles for tumor and matched adjacent tissues from 12 patients. Differential protein spots were identified by mass spectrometric analysis. The cDNA of the differential protein was transfected into colorectal cancer cells, and the biological behavior of these cells was observed. The proteomic profile in colorectal cancer tissues was significantly different from that in normal adjacent tissues. There was a 1.5-fold difference and 60 differential protein spots between cancer and adjacent tissues. Ten differential protein spots were analyzed. Among them, two protein spots were down-regulated and eight protein spots were up-regulated in the primary tumor tissues. After identification by mass spectrometry, the two down-regulated proteins were carbonic anhydrase II and protein disulfide isomerase, and these eight up-regulated proteins included APC-stimulated guanine nucleotide exchange factor, phosphoglycerate kinase 1, fumarate hydratase, aldolase A, activator protein 2B, glutathione S-transferase A3, Arginase and zinc finger protein 64 homolog. After been transfected with carbonic anhydrase II, the invasive ability, mobility and drug resistance of colon cancer lovo cells were significantly reduced. The proteomic profile was significantly different between colorectal cancer tissues and normal adjacent tissues. The down-regulation of carbonic anhydrase II and protein disulfide isomerase and up-regulation of APC-stimulated guanine nucleotide exchange facto, aldolase A, glutathione S-transferase A3 and arginase were correlated with the onset of colorectal cancer.Key words: Colorectal cancer, proteomics

    Experimental study of THGEM detector with mini-rim

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    The gas gain and energy resolution of single and double THGEM detectors (5{\times}5cm2 effective area) with mini-rims (rim is less than 10{\mu}m) were studied. The maximum gain can reach 5{\times}103 and 2{\times}105 for single and double THGEM respectively, while the energy resolution of 5.9 keV X-ray varied from 18% to 28% for both single and double THGEM detectors of different hole sizes and thicknesses.All the experiments were investigated in mixture of noble gases(argon,neon) and small content of other gases(iso-butane,methane) at atmospheric pressure.Comment: 4pages,6figures, it has been submitted to Chinese Physics

    Auto-correlative weak-value amplification under strong noise background

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    In the general optical metro-logical protocols based on the weak-value amplification(WVA) approach, it is beneficial to choose the pre-selected state and the post-selected one to be nearly orthogonal for improving the sensitivity. However, the orthogonality of the post-selection decreases the probability of detecting photons and makes the weak measurement difficult, especially when there is strong noise background and the pointer is drowned in noise. In this article, we investigate a modified weak measurement protocol with a temporal pointer, namely, the auto-correlative weak-value amplification (AWVA) approach. We find it can significantly improve the precision of optical metrology under Gaussian white noise, especially with a negative signal-to-noise ratio. With the AWVA approach, a small longitudinal time delay (tiny phase shift) τ\tau of a Gaussian pulse is measured by implementing two auto-correlative weak measurements. The small quantities are obtained by measuring the auto-correlation coefficient of the pulses instead of fitting the shift of the mean value of the probe. Simulation results show that the AWVA approach outperforms the standard WVA technique in the time domain, remarkably increasing the precision of weak measurement under strong noise background.Comment: 15 pages, 10 figure

    The fast light of CsI(Na) crystals

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    The responds of different common alkali halide crystals to alpha-rays and gamma-rays are tested in our research. It is found that only CsI(Na) crystals have significantly different waveforms between alpha and gamma scintillations, while others have not this phenomena. It is suggested that the fast light of CsI(Na) crystals arises from the recombination of free electrons with self-trapped holes of the host crystal CsI. Self-absorption limits the emission of fast light of CsI(Tl) and NaI(Tl) crystals.Comment: 5 pages, 11 figures Submit to Chinese Physics

    Detection of a parsec-scale jet in a radio-quiet narrow-line Seyfert 1 galaxy with highly accreting supermassive black hole

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    The jet in active galactic nuclei (AGN) is a key ingredient in understanding the co-evolution of galaxies and their central supermassive black holes (SMBHs). Unfortunately, the mechanism of jet launching and collimation is still elusive. The observational evidence of decreasing radio loudness with increasing Eddington ratio implies that the jet should be coupled with the accretion process. To further explore the relationship between the jet and accretion, it is necessary to extend our knowledge of the jet to an extreme end of the Eddington ratio distribution of AGN. Using Very Long Baseline Array (VLBA), we report the detection of the parsec-scale radio structure in Mrk 335, a radio-quiet narrow-line Seyfert 1 galaxy with an Eddington ratio close to/above unity. The VLBA image at 1.5 GHz reveals an elongated structure extending ∼20 pc in north-south direction with a peak flux density of 1.98 \ub1 0.05 mJy beam-1 and radio brightness temperatures as high as 6 7 107 K. This feature provides a strong evidence of a parsec-scale (bipolar) jet launched from a highly accreting SMBH. We discuss the result by comparing Mrk 335 with other highly accreting systems, e.g. Galactic black holes and tidal disruption events, and recall the discovery of collimated corona in the vicinity of SMBH in Mrk 335 by previous X-ray observations, whose relation to the parsec-scale radio jet should be explored by future simultaneous X-ray spectroscopy and high resolution radio observations

    Y Chromosomes of 40% Chinese Are Descendants of Three Neolithic Super-grandfathers

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    Demographic change of human populations is one of the central questions for delving into the past of human beings. To identify major population expansions related to male lineages, we sequenced 78 East Asian Y chromosomes at 3.9 Mbp of the non-recombining region (NRY), discovered >4,000 new SNPs, and identified many new clades. The relative divergence dates can be estimated much more precisely using molecular clock. We found that all the Paleolithic divergences were binary; however, three strong star-like Neolithic expansions at ~6 kya (thousand years ago) (assuming a constant substitution rate of 1e-9/bp/year) indicates that ~40% of modern Chinese are patrilineal descendants of only three super-grandfathers at that time. This observation suggests that the main patrilineal expansion in China occurred in the Neolithic Era and might be related to the development of agriculture.Comment: 29 pages of article text including 1 article figure, 9 pages of SI text, and 2 SI figures. 5 SI tables are in a separate ancillary fil

    Effective components screening and anti-myocardial infarction mechanism study of the Chinese medicine NSLF6 based on "system to system" mode

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    <p>Abstract</p> <p>Background</p> <p><it>Shuanglong </it>formula (SLF), a Chinese medicine composed of <it>panax ginseng </it>and <it>salvia miltiorrhiza </it>exhibited significant effect in the treatment of myocardial infarction (MI) in clinical. Because of the complex nature and lack of stringent quality control, it's difficult to explain the action mechanism of SLF.</p> <p>Method</p> <p>In this study, we present a "system to system" (S2S) mode. Based on this mode, SLF was simplified successively through bioactivity-guided screening to achieve an optimized minimal phytochemical composition (new formula NSLF6) while maintaining its curative effect for MI.</p> <p>Results</p> <p>Pharmacological test combining with the study of systems biology show that NSLF6 has activity for treatment MI through synergistic therapeutic efficacies between total ginsenosides and total salvianolic acids via promoting cardiac cell regeneration and myocardial angiogenesis, antagonistic myocardial cell oxidative damage.</p> <p>Conclusions</p> <p>The present S2S mode may be an effective way for the discovery of new composite drugs from traditional medicines.</p
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