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51.
Gang Li Tianming Liu Jingxin Nie Lei Guo Jarema Malicki Andrew Mara Scott A Holley Weiming Xia Stephen T C Wong 《Cytometry. Part A》2007,71(10):835-845
The zebrafish has become an important vertebrate animal model for the study of developmental biology, functional genomics, and disease mechanisms. It is also being used for drug discovery. Computerized detection of blob objects has been one of the important tasks in quantitative phenotyping of zebrafish. We present a new automated method that is able to detect blob objects, such as nuclei or cells in microscopic zebrafish images. This method is composed of three key steps. The first step is to produce a diffused gradient vector field by a physical elastic deformable model. In the second step, the flux image is computed on the diffused gradient vector field. The third step performs thresholding and nonmaximum suppression based on the flux image. We report the validation and experimental results of this method using zebrafish image datasets from three independent research labs. Both sensitivity and specificity of this method are over 90%. This method is able to differentiate closely juxtaposed or connected blob objects, with high sensitivity and specificity in different situations. It is characterized by a good, consistent performance in blob object detection. 相似文献
52.
Chemically sulfated polysaccharide (S-GAP-P) was derived from water-insoluble polysaccharide of Grifola frondosa mycelia. In this research, we investigated the anticancer effects of S-GAP-P and its combination with 5-fluorouracil (5-FU) on human gastric carcinoma SGC-7901 cells. Results showed that S-GAP-P distinctly inhibited SGC-7901 cells growth in a dose-dependent manner and induced cell apoptosis evidenced by characteristic DNA ladder and sub-G0/G1 peak. Furthermore, the combination of S-GAP-P (10–50 μg/ml) with 1 μg/ml 5-FU resulted in a significant inhibition on SGC-7901 cells growth, meaning the beneficial interaction between the two drugs. All these results suggested that S-GAP-P has evident anticancer activity through apoptotic induction and could significantly accelerate the anticancer activity of 5-FU. 相似文献
53.
Small molecules blocking the entry of severe acute respiratory syndrome coronavirus into host cells 总被引:4,自引:0,他引:4 下载免费PDF全文
Yi L Li Z Yuan K Qu X Chen J Wang G Zhang H Luo H Zhu L Jiang P Chen L Shen Y Luo M Zuo G Hu J Duan D Nie Y Shi X Wang W Han Y Li T Liu Y Ding M Deng H Xu X 《Journal of virology》2004,78(20):11334-11339
Severe acute respiratory syndrome coronavirus (SARS-CoV) is the pathogen of SARS, which caused a global panic in 2003. We describe here the screening of Chinese herbal medicine-based, novel small molecules that bind avidly with the surface spike protein of SARS-CoV and thus can interfere with the entry of the virus to its host cells. We achieved this by using a two-step screening method consisting of frontal affinity chromatography-mass spectrometry coupled with a viral infection assay based on a human immunodeficiency virus (HIV)-luc/SARS pseudotyped virus. Two small molecules, tetra-O-galloyl-beta-D-glucose (TGG) and luteolin, were identified, whose anti-SARS-CoV activities were confirmed by using a wild-type SARS-CoV infection system. TGG exhibits prominent anti-SARS-CoV activity with a 50% effective concentration of 4.5 microM and a selective index of 240.0. The two-step screening method described here yielded several small molecules that can be used for developing new classes of anti-SARS-CoV drugs and is potentially useful for the high-throughput screening of drugs inhibiting the entry of HIV, hepatitis C virus, and other insidious viruses into their host cells. 相似文献
54.
Photosynthesis Research - Formation of photosynthetic complexes leads to a higher demand for Fe–S clusters. We hypothesized that in the facultative phototrophic alpha-proteobacterium... 相似文献
55.
Xiaopeng Ji Bin Zhao Zhaoping Cheng Biao Si Zhiheng Wang Yanhua Duan Pei Nie Haiou Li Shifeng Yang Hui Jiao Ximing Wang 《PloS one》2014,9(4)
Objective
To explore the clinical value of low-dose prospectively electrocardiogram-gated axial dual-source CT angiography (low-dose PGA scanning, CTA) in patients with pulsatile bilateral bidirectional Glenn shunt (bBDG) as an alternative noninvasive method for postoperative morphological estimation.Methods
Twenty patients with pulsatile bBDG (mean age 4.2±1.6 years) underwent both low-dose PGA scanning and conventional cardiac angiography (CCA) for the morphological changes. The morphological evaluation included the anatomy of superior vena cava (SVC) and pulmonary artery (PA), the anastomotic location, thrombosis, aorto-pulmonary collateral circulation, pulmonary arteriovenous malformations, etc. Objective and subjective image quality was assessed. Bland–Altman analysis and linear regression analyses were used to evaluate the correlation on measurements between CTA and CCA. Effective radiation dose of both modalities was calculated.Results
The CT attenuation value of bilateral SVC and PA was higher than 300 HU. The average subjective image quality score was 4.05±0.69. The morphology of bilateral SVC and PA was displayed completely and intuitively by CTA images. There were 24 SVC above PA and 15 SVC beside PA. Thrombosis was found in 1 patient. Collateral vessels were detected in 13 patients. No pulmonary arteriovenous malformation was found in our study. A strong correlation (R2>0.8, P<0.001) was observed between the measurements on CTA images and on CCA images. Bland–Altman analysis demonstrated a systematic overestimation of the measurements by CTA (the mean value of bias>0).The mean effective dose of CTA and CCA was 0.50±0.17 mSv and 4.85±1.34 mSv respectively.Conclusion
CT angiography with a low-dose PGA scanning is an accurate and reliable noninvasive examination in the assessment of morphological changes in patients with pulsatile bBDG. 相似文献56.
Yoo J Rodriguez Perez CE Nie W Edwards RA Sinnett-Smith J Rozengurt E 《American journal of physiology. Gastrointestinal and liver physiology》2012,302(8):G805-G814
The myofibroblast has recently been identified as an important mediator of tumor necrosis factor-α (TNF-α)-associated colitis and cancer, but the mechanism(s) involved remains incompletely understood. Recent evidence suggests that TNF-α is a central regulator of multiple inflammatory signaling cascades. One important target of TNF-α may be the signaling pathway downstream of the epidermal growth factor receptor (EGFR), which has been associated with many human cancers. Here, we show that long-term exposure of 18Co cells, a model of human colonic myofibroblasts, with TNF-α led to a striking increase in cell surface EGFR expression, an effect that was completely inhibited by cycloheximide. Subsequent EGFR binding by EGF and heparin binding (HB)-EGF was associated with enhanced EGFR tyrosine kinase activity, prolonged ERK activation, and a significant increase in cyclooxygenase-2 (COX-2) expression compared with 18Co cells treated with EGF and HB-EGF alone. TNF-α also increased EGFR expression and signaling in primary myofibroblasts isolated from human colon tissue. TNF-α-induced upregulation of EGFR may be a plausible mechanism to explain the exaggerated cellular responsiveness that characterizes inflammatory bowel disease and that may contribute to a microenvironment that predisposes to colitis-associated cancer through enhanced COX-2 expression. 相似文献
57.
Chen Minmin Nie Gongping Yang Liuyan Zhang Yongchun Cai Youming 《Plant Growth Regulation》2021,95(1):49-64
Plant Growth Regulation - As one of the most popular bulbous plant with high ornamental value, Lilium spp. has been used as cut flower or green plants in urban landscapes and home gardening. We... 相似文献
58.
懒猴属的核糖体DNA变异及其种间分化关系 总被引:3,自引:2,他引:3
用15种限制性内切酶和人28S、18SrDNA探针构建了懒猴属各物种核糖体DNA重复单位的限制性内切酶图谱。在进化速率较高的非转录间隔区,在大、中、小懒猴中分别定位了23、24、24个酶切位点。大懒猴与中懒猴有12个位点不同,与小懒猴有14个位点不同,而中、小懒猴间则只有一个位点的差异。经过计算,大懒猴与中懒猴的遗传距离值为12.65%,与小懒猴的差异为14.24%,中、小懒猴间的差异则仅为0.7 相似文献
59.
本文研究了不同底物(N_2,H_2,N_2O,NaN_3,C_2H_2)对棕色固氮菌固氮酶及其钼铁蛋白荧光光谱的影响。结果表明,上述底物均能络合在钼铁蛋白及固氮酶上,但络合程度不同,从而为固氮酶系统有多个不同的底物络合中心,底物络合中心在钼铁蛋白分子上,铁蛋白对钼铁蛋白有变构作用,提供了光谱学证据。 相似文献
60.
A series of dinickel acetato complexes [LNi2(OAc)(solvent)x](ClO4)2 (1-3, 5) as well as related complexes [LNi2(OAc)2](OAc) (4) and [LNi2(OAc)(NO3)2] (6), all derived from three pyrazolate-based binucleating ligands, have been prepared and characterized by X-ray crystallography. The solid state structures reveal different acetate binding modes (μ1,3-bridging and bidentate chelating) plus severe twisting and tilting of the μ1,3-acetate bridges with respect to their bimetallic scaffolds, reflecting the great flexibility of carboxylate coordination. Magnetic properties of all six complexes have been investigated, and the strength of antiferromagnetic coupling is discussed in the light of the structural differences, suggesting a magnetostructural correlation for acetato-bridged complexes. 相似文献