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Search Results: 1 - 10 of 80639 matches for " Zhidong Liu "
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Electrochemical Performance of a Carbon Nanotube/La-Doped TiO2 Nanocomposite and its Use for Preparation of an Electrochemical Nicotinic Acid Sensor
Jing Wu,Hanxing Liu,Zhidong Lin
Sensors , 2008, DOI: 10.3390/s8117085
Abstract: A carbon nanotube/La-doped TiO2 (La-TiO2) nanocomposite (CLTN) was prepared by a procedure similar to a complex/adsorption process. Scanning electron microscopy (SEM) images show that the La-TiO2 distributes on the carbon nanotube walls. The CLTN was mixed with paraffin to form a CLTN paste for the CLTN paste electrode (CLTNPE). The electrochemical characteristics of CLTNPE were compared with that of conventional carbon electrodes such as the carbon paste electrode (CPE) and glass carbon electrode (GC). The CLTNPE exhibits electrochemical activity and was used to investigate the electrochemistry of nicotinic acid (NA). The modified electrode has a strong electrocatalytic effect on the redox of NA. The cyclic voltammetry (CV) redox potential of NA at the CLTNPE is 320 mV. The oxidation process of NA on the CLTNPE is pH dependent. A sensitive chronoamperometric response for NA was obtained covering a linear range from 1.0×10-6 mol·L-1 to 1.2×10-4 mol·L-1, with a detection limit of 2.7×10-7 mol·L-1. The NA sensor displays a remarkable sensitivity and stability. The mean recovery of NA in the human urine is 101.8%, with a mean variation coefficient (RSD) of 2.6%.
Research Progresses of Circulating Tumor Cells in Diagnosis and Treatment of ?Early Lung Cancer
Xinchun DUAN, Zhidong LIU, Shaofa XU
- , 2017, DOI: : 10.3779/j.issn.1009-3419.2017.10.07
Abstract: As one of the important liquid biopsies, circulating tumor cells (CTCs) shows more and more clinical values in the treatment of lung cancer such as diagnostic screening, treatment evaluation, postoperative monitoring, and prognosis predicting etc. A large number of small pulmonary nodules patients are detected when screening the high risk population of lung cancer. However, small lung nodules are not equal to lung cancer, and 90%-95% of them are benign lesion, therefore, to accurately and correctly differentiate whether it is benign or malignant when patients firstly detected and treat a small pulmonary nodule is become a new opportunity and challenge for clinician. With the improvement of CTCs detection technology, whether it will play an important role in early differential diagnosis of lung cancer. And whether it will have clinical significance to early lung cancer surgery operations. These require further researches and explorations so as to achieve clinical transformation in the future.
Electrochemical Performances of Electroactive Nano-LayeredOrganic-Inorganic Perovskite Containing Trivalent Iron Ion and its Use for a DNA Biosensor Preparation
Jing Wu,Hanxing Liu,Zhidong Lin,Minghe Cao
International Journal of Analytical Chemistry , 2010, DOI: 10.1155/2010/419439
Abstract: A steady nano organic-inorganic perovskite hybrid with Fe(CN)6 (3-AMP = 3-methylaminopyridine) was prepared in the air. The structure is an unusual layered organic-inorganic type. The resulting hybrid enveloped in paraffin to prepare Fe(CN)6 paste electrode (HPE) shows good electrochemical activity and a couple of oxidation and reduction peaks with potential of cyclic voltammometry (CV) at around 440?mV and 30?mV. Compared with that on CPE, oxidation potential of on HPE shifts negatively 259.7?mV and that of reduction shifts positively 338.7?mV, which exhibits that Fe(CN)6 can accelerate the electron-transfer to improve the electrochemical reaction reversibility. Such characteristics of Fe(CN)6 have been employed to prepare the DNA biosensor. The single-strand DNA (ssDNA) and double-strand DNA (dsDNA) immobilized on HPE, respectively, can improve the square wave voltammometry (SWV) current and SWV potential shifts positively. The effect of pH was evaluated. And there is hybridization peak on SWV curve using HPE immobilized ssDNA in the complementary ssDNA solution. And HPE immobilized ssDNA can be utilized to monitor the DNA hybridization and detect complementary ssDNA, covering range from to ?g/mL with detection limit of ?g/mL. The DNA biosensor exhibits a good stability and reproducibility. 1. Introduction In recent years, layered organic-inorganic perovskite hybrids have attracted great interest of researchers. Organic-inorganic perovskite hybrids offer an important opportunity to combine useful properties from two chemical realms, organic and inorganic compounds, within a single molecular scale composite. Especially, the design and generation of the organic-inorganic self-organized quantum well structure represent an approach to synthesis that offers new horizons in the context of synthetic chemistry and its possible impact on new material technology [1]. The hybrid organoammonium halometallate(II), (RNH3)2MX4, series of layer perovskite structures have played a significant role in the development of the understanding of low-dimensional magnetic systems and, more recently, of semiconducting, optical, photoelectric materials [2–6]. So far, only organic-inorganic perovskite hybrids containing the chemical element of tin (Sn), copper (Cu), and lead (Pb) have been used to application [7–13]. While it is not reported that organic-inorganic perovskite hybrids were used as electrochemical materials. On the other hand, a few organic-inorganic perovskite hybrids containing M3+ have been reported. As for conventional perovskite frameworks, trivalent metal
MicroRNA Genes Derived from Repetitive Elements and Expanded by Segmental Duplication Events in Mammalian Genomes
Zhidong Yuan,Xiao Sun,Hongde Liu,Jianming Xie
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0017666
Abstract: MicroRNAs (miRNAs) are a class of small noncoding RNAs that regulate gene expression by targeting mRNAs for translation repression or mRNA degradation. Many miRNAs are being discovered and studied, but in most cases their origin, evolution and function remain unclear. Here, we characterized miRNAs derived from repetitive elements and miRNA families expanded by segmental duplication events in the human, rhesus and mouse genomes. We applied a comparative genomics approach combined with identifying miRNA paralogs in segmental duplication pair data in a genome-wide study to identify new homologs of human miRNAs in the rhesus and mouse genomes. Interestingly, using segmental duplication pair data, we provided credible computational evidence that two miRNA genes are located in the pseudoautosomal region of the human Y chromosome. We characterized all the miRNAs whether they were derived from repetitive elements or not and identified significant differences between the repeat-related miRNAs (RrmiRs) and non-repeat-derived miRNAs in (1) their location in protein-coding and intergenic regions in genomes, (2) the minimum free energy of their hairpin structures, and (3) their conservation in vertebrate genomes. We found some lineage-specific RrmiR families and three lineage-specific expansion families, and provided evidence indicating that some RrmiR families formed and expanded during evolutionary segmental duplication events. We also provided computational and experimental evidence for the functions of the conservative RrmiR families in the three species. Together, our results indicate that repetitive elements contribute to the origin of miRNAs, and large segmental duplication events could prompt the expansion of some miRNA families, including RrmiR families. Our study is a valuable contribution to the knowledge of evolution and function of non-coding region in genome.
Expression of Integrins and Extracellular Matrix Proteins in Non-small Cell Lung Cancer:Correlation with Tumor Metastasis and Prognosis
Zhi YANG,Shaofa XU,Haiqing ZHANG,Zhidong LIU
Chinese Journal of Lung Cancer , 2009,
Abstract: Background and objective As invasion and metastasis of cancer seriously threaten human's life, it is of more important clinical significance to understand and evaluate the biologic behavior of cancer correctly. Abnormal expression of integrin and ECM proteins play an important role in invasion and metastasis of cancer. The objective of this study is to analyze the expression of the integrin α5, β1 and ECM proteins in patients with NSCLC and its correlationwith lymph node (LN) metastasis as well as prognosis, and to evaluate its roles in the metastasis of tumor. Methods The expression of integrin α5, β1 and collagen type Ⅳ, fibronectin, tenascin was determined by immunohistochemistry. The relationship was analysized that between integrin α5, β1 and ECM proteins expression and clinico-pathologic parameters especially LN metastasis and prognosis. Results The expression of collagen type Ⅳ was negatively correlated with LN metastasis, and positively to prognosis of patients; The expression of integrin α5, β1 was positively correlated with LN metastasis, and integrin α5 was negatively to prognosis of patients. The expression of integrin α5 was positively correlated with the expression of integrin β1, and negatively with the expression of collagen type Ⅳ. The expressionof collagen type Ⅳ in stage Ⅰ disease P-TNM stage was remarkably higher than that in stage Ⅲ disease and poordifferentiated disease (P <0.001), but integrin α5, β1 was significantly higher than that in stage Ⅲ disease and poordifferentiated disease. Conclusion Increased expression of integrin α5, β1 and decreased expression of ECM significantly correlated with LN metastasis of NSCLC. Integrin α5 and collagen type Ⅳ are prognosic factors in patients with NSCLC.
Serum Tumor Markers for Lung Cancer Diagnosis
Zikun LIANG,Shaofa XU,Zhidong LIU,Shijie ZHOU
Chinese Journal of Lung Cancer , 2008,
Abstract: Background and objective Progress has been made in research of lung cancer tumor markers in recent years, and these tumor markers have been used in clinical application. This study is to evaluate the regimens of six serum tumor markers in lung cancer diagnosis. Methods The serum levels of the six tumor markers (NSE、pro-GRP、CYFRA21-1、SCC、p53 antibody and CA199) were detected in 80 healthy adults, 170 patients with lung cancer and 80 patients with respiratory infection by ELISA. Results The levels of the six tumor markers in patients with lung cancer were remarkably higher than those in healthy adults and patients with respiratory infection (P<0.01). The levels of the NSE、pro-GRP in patients with small cell lung cancer were significantly higher than those in other subtypes of the lung cancer (P<0.01); The levels of the CYFRA21-1、SCC in patients with squamous carcinoma was remarkably higher than that in other subtypes of the lung cancer (P<0.01). The sensitivity of the NSE、pro-GRP in diagnosing small cell lung cancer was remarkably higher than that in other subtypes of the lung cancer (P<0.01); The sensitivity of the CYFRA21-1、SCC in diagnosing squamous carcinoma was remarkably higher than that in other subtypes of the lung cancer (P<0.01). The sensitivity of the tumor markers combinations in diagnosing lung cancer was remarkably higher than that of the single marker (P<0.01). Conclusion Detection of the six tumor markers is helpful for diagnosis lung cancer. Combination of NSE and pro-GRP is more economic than other combinations in diagnosing small cell lung cancer; Combined CYFRA21-1、SCC is more economic than other combinations in diagnosing squamous carcinoma.
Overexpression of IL-8 and MMP-9 Confer High Malignant Phenotype in Patients with Non-small Cell Lung Cancer
Zhidong LIU,Shaofa XU,Ning XIAO,Changxing SONG
Chinese Journal of Lung Cancer , 2010,
Abstract: Background and objective IL-8 (interleukin-8) has been identified as a chemotactic factor, but recent found that IL-8 and matrix metalloproteinase-9 (MMP-9) are important cytokines which are closely related to the growth and metastasis of tumor. The aim of this study is to explore the relationship between IL-8, MMP-9 expressions and clinical pathological features of non-small cell lung cancer (NSCLC) patients and evaluate the diagnostic potential of IL-8, MMP-9 as tumor markers. Methods The serum levels of IL-8 and MMP-9 were detected by enzyme-linked immunosorbentassay (ELISA) in 141 NSCLC patients, 40 healthy adults and 40 patients with benign pulmonary disease. The expressions of IL-8 and MMP-9 were detected by immunohistochemical method in 95 NSCLC tissues, and 21 benign disease lung tissues, 25 normal lung tissues as control. Results The level of expression of IL-8 and MMP-9 in serum and tissue of NSCLC was significantly higher than that of healthy and benign respiratory disease, and the expression was gradually increased with the upgrade of clinicopathological stage. The serum and tissue expression of IL-8 and MMP-9 in NSCLC patients with lymph node metastasis was remarkably higher than that without lymph node metastasis. There is an positive correlation (r=0.765) between IL-8 and MMP-9 in the tissue of NSCLC patients. Conclusion This study has confirmed that IL-8, MMP-9 expressions are related to the development of NSCLC. There is an obvious correlation between IL-8 expression and lymph node metastasis, IL-8 may facilitate the lymph node metastasis by up-regulating MMP-9 expression. Serum level of IL-8 is a valuable auxiliary parameter in diagnosing lymph node metastases of NSCLC with good sensitivity and specificity.
Fidelity susceptibility and topological phase transition of a two dimensional spin-orbit coupled Fermi superfluid
Xuebing Luo,Kezhao Zhou,Wuming Liu,Zhaoxin Liang,Zhidong Zhang
Physics , 2013, DOI: 10.1103/PhysRevA.89.043612
Abstract: We investigate the fidelity susceptibility (FS) of a two-dimensional spin-orbit coupled (SOC) Fermi superfluid and the topological phase transition driven by a Zeeman field in the perspective of its ground-state wave-function. Without Zeeman coupling, FS shows new features characterizing the BCS-BEC crossover induced by SOC. In the presence of a Zeeman field, the topological phase transition is explored using both FS and the topological invariant. In particular, we obtain the analytical result of the topological invariant which explicitly demonstrates that the topological phase transition corresponds to a sudden change of the ground state wave-function. Consequently, FS diverges at the phase transition point with its critical behavior being: $\chi \propto ln|h-h_{c}|$ . Based on this observation, we conclude that the topological phase transition can be detected by measuring the momentum distribution in cold atoms experiment.
An Effective Extract Method of Phospholipids from Antarctic Krill Euphausea superba  [PDF]
Xiaoqing Tian, Chengqi Fan, Zhidong Liu, Hongliang Huang, Yanan Lu
Open Journal of Marine Science (OJMS) , 2018, DOI: 10.4236/ojms.2018.82015
Phospholipids are one of the major bioactive ingredients of Antarctic krill Euphausea superba. A feasible and effective extraction method of Antarctic krill oil was investigated and modified by orthogonal test which the ratio of solid to liquid was 1:2.5, extraction time was 5 min, ratio of ethyl acetate (EA) and n-butanol (BuOH) was 1:1. With this method, the extract of krill oil has a higher phospholipids content of 27.7% - 42.3%, together with total oil yields of 4.15% - 6.18%.
Dynamics of a ±1/2 Defect Pair in a Confined Geometry  [PDF]
Lixia Lu, Zhidong Zhang
Journal of Modern Physics (JMP) , 2014, DOI: 10.4236/jmp.2014.518204
Abstract: This paper investigated the dynamics of a dipole of ±1/2 parallel wedge disclination lines in a confined geometry, based on Landau-de Gennes theory. The behavior of the pair depends on the competition between two kinds of forces: the attractive force between the two defects, aggravating the annihilation process, and the anchoring forces coming from the substrates, inhibiting the annihilation process. There are three states when the system is equilibrium, divided by two critical thicknesses dc1 and dc2 (existing when r015ξ, r0 is the initial distance between the two defects), both changing linearly with r0. When the cell gap ddc1, the two defects coalesce and annihilate. The dynamics follows the function of r(t0-t)α during the annihilation step when d is sufficiently large, relative to r0, where r is the relative distance between the pair and t0 is the coalescence time. α decreases with the decrease of d or the increase of r0. The annihilation process has delicate structures: when r015ξ and ddc2 or r015ξand ddc1, the two defects annihilate and the system is uniaxial at equilibrium state; when r015ξ and dc2ddc1, the two
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