31 results on '"Gao, Jianfang"'
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2. Strong convergence of the semi-implicit Euler method for nonlinear stochastic Volterra integral equations with constant delay.
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Gao, Jianfang, Liang, Hui, and Ma, Shufang
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STOCHASTIC convergence , *EULER method , *VOLTERRA equations , *NONLINEAR equations , *STOCHASTIC analysis - Abstract
Abstract This paper is mainly concerned with the strong convergence analysis of the semi-implicit Euler method for nonlinear stochastic Volterra integral equations (SVIEs) with constant delay. The solvability and the boundedness of the numerical solution are established. It is proved that the strong convergence order of the semi-implicit Euler method is 0.5 under Lipschitz conditions. Moreover, the strong superconvergence order is 1.0 if further, the kernel σ of the stochastic term satisfies σ (0) = σ (τ) = 0. The theoretical results are illustrated by extensive numerical examples. [ABSTRACT FROM AUTHOR]
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- 2019
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3. Oscillation analysis of numerical solutions for delay differential equations with real coefficients.
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Wang, Yunzhu and Gao, Jianfang
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BINOMIAL coefficients , *OSCILLATIONS , *DELAY differential equations , *NUMERICAL analysis , *COMPUTER simulation , *MATHEMATICAL models - Abstract
The paper is mainly concerned with the oscillations of numerical solutions by the linear θ − methods for a kind of linear delay differential equations with positive and negative coefficients. Some conditions under which the numerical solutions are oscillatory are obtained and it is proved that oscillations of the analytical solutions are preserved by the numerical solutions under mild conditions. Numerical experiments are given to demonstrate our results. [ABSTRACT FROM AUTHOR]
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- 2018
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4. Oscillations analysis for two kinds of Nicholson models.
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Sui, Tianqi, Gao, Jianfang, and Lv, Xueqin
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OSCILLATION theory of differential equations , *LINEAR differential equations , *OSCILLATIONS , *DIFFERENCE equations , *DELAY differential equations - Abstract
Oscillations of two kinds of delay Nicholson models with density constraint are mainly considered. The nonlinear models are transformed into the corresponding linear delay differential equation by the theory of oscillation. The difference equations are obtained by using the linear θ − method. Oscillations conditions of the analytical solution and numerical solution of models are obtained. The properties of non-oscillatory solutions are investigated. In order to better explain the results, some numerical examples are given. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Numerical oscillation and non-oscillation for differential equation with piecewise continuous arguments of mixed type.
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Gao, Jianfang
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OSCILLATIONS , *DIFFERENTIAL equations , *RUNGE-Kutta formulas , *ANALYTICAL solutions , *APPLIED mathematics - Abstract
The paper deals with the oscillation and non-oscillation of the Runge–Kutta methods for a differential equation with piecewise continuous arguments of mixed type. The conditions of the oscillation and non-oscillation for the Runge–Kutta method are obtained. It is proved that oscillation of the analytic solution is not preserved by the Runge–Kutta method under any conditions. The conditions under which the non-oscillation of analytic solutions is preserved by the Runge–Kutta method are obtained. Some numerical experiments are given. [ABSTRACT FROM AUTHOR]
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- 2017
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6. The effect of two cryopreservation methods on human sperm DNA damage.
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Liu, Taixiu, Gao, Jianfang, Zhou, Niya, Mo, Min, Wang, Xiaogang, Zhang, Xi, Yang, Huan, Chen, Qing, Ao, Lin, Liu, Jinyi, Cui, Zhihong, and Cao, Jia
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FROZEN semen , *DNA damage , *SEMEN analysis , *SPERM banks , *FREEZE-thaw cycles , *GEL electrophoresis - Abstract
Several methods are currently available for selection when conducting sperm cryopreservation, however, these methods might cause different degrees of damage on sperm DNA. The aim of the this study is to compare the effects of storage at −80 °C (in ultra-low temperature refrigerator) and at −196 °C (in liquid nitrogen) on sperm DNA damage, thus to provide a reference for choosing the right method according to different aims. We randomly collected 28 semen samples from college students of Chongqing city. The samples stored at −80 °C were neat semen samples and the samples stored at −196 °C were mixed with additional cryoprotectants. Each sample was subjected to two freezing-thawing cycles, and the sperm DNA damage levels of fresh and thawed samples were measured by single cell gel electrophoresis (SCGE) and sperm chromatin structure assay (SCSA). Both SCGE and SCSA assays showed cryopreservation induced significant damage to sperm DNA. However, storage at −196 °C lead to more severe damage to sperm DNA than storage at −80 °C measured by SCSA. Sperm DNA damage increased simultaneously with the higher frequency of freezing-thawing cycles. We concluded that storage of neat semen samples at −80 °C had milder damage to sperm DNA than storage at −196 °C mixed with cryoprotectants. To avoid additional sperm DNA damage, repeated freezing and thawing should be prevented. [ABSTRACT FROM AUTHOR]
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- 2016
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7. Oscillation analysis of numerical solutions in the ?-methods for differential equation of advanced type.
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Gao, Jianfang and Liu, Shimeng
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OSCILLATION theory of differential equations , *NUMERICAL solutions to differential equations , *OSCILLATIONS , *NUMERICAL analysis , *PERTURBATION theory - Abstract
The paper deals with the oscillation analysis of numerical solution in the ?-methods for differential equations with piecewise constant arguments of advanced type. The conditions of the oscillation for the ?-method are obtained. It is proved that the oscillation of the analytic solution is preserved by the ?- method. Some numerical experiments are given. [ABSTRACT FROM AUTHOR]
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- 2015
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8. Preservation of Oscillations in the Runge-Kutta Method for a Type of Advanced Differential Equation.
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Gao, Jianfang, Shi, Tiantian, and Song, Fuyi
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RUNGE-Kutta formulas , *OSCILLATIONS , *DIFFERENTIAL equations , *MATHEMATICAL proofs , *NUMERICAL analysis - Abstract
This article is concerned with the preservation of oscillations for differential equations with piecewise constant arguments of advanced type. By using the Runge-Kutta method, new oscillation conditions for numerical solution are established. We prove that oscillations of the analytic solution are preserved by the numerical solution in the Runge-Kutta method under some conditions. Some experiments are given. [ABSTRACT FROM PUBLISHER]
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- 2015
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9. Oscillation analysis of numerical solutions for nonlinear delay differential equations of hematopoiesis with unimodal production rate.
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Gao, Jianfang and Song, Fuyi
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NUMERICAL solutions to nonlinear differential equations , *OSCILLATIONS , *HEMATOPOIESIS , *NUMERICAL analysis , *DELAY differential equations - Abstract
This paper is concerned with oscillation and non-oscillation of numerical solutions for nonlinear delay differential equation of hematopoiesis with unimodal production rate. By investigating the roots of characteristic equation, some conditions under which the numerical solution is oscillatory and non-oscillatory are obtained. The properties of non-oscillatory numerical solutions are investigated. To verify our results, we give numerical experiments. [ABSTRACT FROM AUTHOR]
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- 2015
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10. Oscillation Analysis of Numerical Solutions for Nonlinear Delay Differential Equations of Population Dynamics.
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Gao, Jianfang, Song, Minghui, and Liu, Mingzhu
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POPULATION dynamics , *NUMERICAL analysis , *OSCILLATIONS , *NONLINEAR theories , *DIFFERENTIAL equations , *EQUATIONS , *MECHANICAL ventilators - Abstract
This paper is concerned with oscillations of numerical solutions for the nonlinear delay differential equation of population dynamics. The equation proposed by Mackey and Glass for a ”dynamic disease” involves respiratory disorders and its solution resembles the envelope of lung ventilation for pathological breathing, called Cheyne-Stokes respiration. Some conditions under which the numerical solution is oscillatory are obtained. The properties of non-oscillatory numerical solutions are investigated. To verify our results, we give numerical experiments. [ABSTRACT FROM AUTHOR]
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- 2011
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11. Oscillation analysis of numerical solution in the θ-methods for equation x′(t)+ ax(t)+ a 1 x([t −1])=0
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Liu, M.Z., Gao, Jianfang, and Yang, Z.W.
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NUMERICAL analysis , *FUNCTIONAL differential equations , *DIFFERENTIAL equations , *MATHEMATICAL analysis - Abstract
Abstract: The paper deals with the oscillation analysis of numerical solution in the θ-methods for equation x′(t)+ ax(t)+ a 1 x([t −1])=0. The conditions of the oscillation for the θ-method are obtained. It is proved that the oscillation of the analytic solution is preserved by the θ-method. It turns out that the zeros of the linear interpolation function of the numerical solution can converge to the zeros of the analytic solution with the order of accuracy 1 and 2 . Some numerical experiments are given. [Copyright &y& Elsevier]
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- 2007
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12. Study on pulp metabolism of patients with pulpitis using ultra-performance liquid chromatography coupled with Orbitrap mass spectrometry.
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Guo, Ke, Xu, Xiaodong, Gao, Jianfang, Zhang, Ying, Wang, Yu, Zhuang, Yulian, Zhu, Yonggan, Zhou, Zhenfeng, Chen, Xuzhuo, Zhang, Zhongxiao, and Wei, Wenjia
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PULPITIS , *LIQUID chromatography , *MASS spectrometry , *MULTIVARIATE analysis , *DISCRIMINANT analysis - Abstract
• Pulp samples from 20 pulpitis cases together with 20 normal participants were analyzed with a serum metabolomics approach using ultra-high-performance liquid chromatography (UPLC)/Orbitrap mass spectrometry. • Determine the key metabolites of pulpitis and the pathways associated with pulpitis incidence, providing certain foundation for analyzing the relation of metabolites with pulpitis incidence. Pulpitis, a pulp disease caused by caries, trauma, and other factors, has a high clinical incidence. This study focused on identifying possible metabolic biomarkers of pulpitis cases and analyzing the related metabolic pathways for providing a theoretical foundation to diagnose and prevent pulpitis. Pulp samples from 20 pulpitis cases together with 20 normal participants were analyzed with a serum metabolomics approach using ultra-high-performance liquid chromatography (UPLC)/Orbitrap mass spectrometry. Moreover, this work carried out multivariate statistical analysis for screening potential biomarkers of pulpitis. Through biomarker analysis and identification, such as partial least squares discrimination analysis, orthogonal partial least squares discriminant analysis model establishment, correlation analysis, and biomarker pathway analysis, 40 biomarkers associated with 20 metabolic pathways were identified, including 20 upregulated and 20 downregulated metabolites. Those major biomarkers included oxoglutaric acid, inosine, citric acid, and PA(14:1(9Z)/PGD1). Among them, oxoglutaric acid and inosine were most significantly downregulated and had the highest correlation with pulpitis. Among these metabolic pathways, GABAergic synapse and alanine, aspartate, and glutamate metabolism were positively correlated with pulpitis. 4. These biomarkers as well as metabolic pathways may offer the theoretical foundation to understand pulpitis pathogenesis and develop preventive drugs. [ABSTRACT FROM AUTHOR]
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- 2024
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13. CHIP promotes CAD ubiquitination and degradation to suppress the proliferation and colony formation of glioblastoma cells.
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Li, Guanya, Xiao, Kai, Li, Yinan, Gao, Jianfang, He, Shanping, and Li, Tingting
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GLIOBLASTOMA multiforme , *UBIQUITINATION , *PYRIMIDINE nucleotides , *INHIBITION of cellular proliferation , *DNA replication , *CELL proliferation , *DNA synthesis - Abstract
Purpose: Cancer cells are characterized as the uncontrolled proliferation, which demands high levels of nucleotides that are building blocks for DNA synthesis and replication. CAD (carbamoyl-phosphate synthetase 2, aspartate transcarbamylase and dihydroorotase) is a trifunctional enzyme that initiates the de novo pyrimidine synthesis, which is normally enhanced in cancer cells to preserve the pyrimidine pool for cell division. Glioma, representing most brain cancer, is highly addicted to nucleotides like pyrimidine to sustain the abnormal growth and proliferation of cells. CAD is previously reported to be dysregulated in glioma, but the underlying mechanism remains unclear. Methods: The expression of CAD and CHIP (carboxyl terminus of Hsc70-interacting protein) protein in normal brain cells and three glioblastoma (GBM) cell lines were measured by immunoblots. Lentiviruses-mediated expression of target proteins or shRNAs were used to specifically overexpress or knock down CAD and CHIP. Cell counting, colony formation, apoptosis and cell cycle assays were used to assess the roles of CAD and CHIP in GBM cell proliferation and survival. Co-immunoprecipitation and ubiquitination assays were used to examine the interaction of CHIP with CAD and the ubiquitination of CAD. The correlation of CAD and CHIP expression with GBM patients' survival was obtained by analyzing the GlioVis database. Results: In this study, we showed that the expression of CAD was upregulated in glioma, which was positively correlated with the tumor grade and survival of glioma patients. Knockdown of CAD robustly inhibited the cell proliferation and colony formation of GBM cells, indicating the essential role of CAD in the pathogenesis of GBM. Mechanistically, we firstly identified that CAD was modified by the K29-linked polyubiquitination, which was mediated by the E3 ubiquitin ligase CHIP. By interacting with and ubiquitinating CAD, CHIP enhanced its proteasomal and lysosomal degradation, which accounted for the anti-proliferative role of CHIP in GBM cells. To sustain the expression of CAD, CHIP is significantly downregulated, which is correlated with the poor prognosis and survival of GBM patients. Notably, the low level of CHIP and high level of CAD overall predict the short survival of GBM patients. Conclusion: Altogether, these results illustrated the essential role of CAD in GBM and revealed a novel therapeutic strategy for CAD-positive and CHIP-negative cancer. [ABSTRACT FROM AUTHOR]
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- 2024
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14. Antioxidant status and cytogenetic damage in hospital workers occupationally exposed to low dose ionizing radiation.
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Gao, Jianfang, Dong, Xiaomei, Liu, Taixiu, Zhang, Lilong, and Ao, Lin
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HOSPITAL personnel , *IONIZING radiation , *OXIDANT status , *SUPEROXIDE dismutase , *GLUTATHIONE peroxidase , *ERYTHROCYTES , *RADIATION doses , *MULTIPLE regression analysis - Abstract
• Differences were found between hospital workers and controls in terms of MDA. • MN frequency was correlated with duration of occupational exposure and exposure doses. • A weak positive relationship was found between MDA level and MN frequency. The aim of the present study was to assess the oxidative stress level and chromosomal damage induced by occupational exposure to low dose ionizing radiation (LDIR). Two hundred and eighteen hospital workers occupationally exposed to LDIR were included in this study, along with 118 healthy age- and gender-comparable controls. Occupational dosimetry records were collected over the last year and revealed that the accumulated annual dose for each hospital worker was below the permissible limit of the International Commission on Radiological Protection (ICRP). The individuals' oxidative and antioxidative status were determined by measuring the activities of copper zinc-superoxide dismutase (CuZn-SOD), glutathione peroxidase (GSH-Px), catalase (CAT) enzymes, and the levels of malondialdehyde (MDA) in erythrocytes. The effect of radiation on chromosomal integrity was measured by the frequency of micronuclei (MN) formation using the cytokinesis block technique. Our results showed that the activities of CuZn-SOD and CAT enzymes and MDA levels observed in the hospital workers were higher than those in the controls (p < 0.05). We did not find significant difference in GSH-Px enzyme activity between the two groups (p = 0.247). A higher frequency of MN was found in exposed groups than in the controls [3(1–5) ‰ versus 2(0.75–4) ‰; p <0.001]. The difference was significant for males (p = 0.012), but not females (p = 0.14). Multiple linear regression analysis showed differences in the oxidant activities and MN frequency between hospital workers and controls adjusted for age, gender, smoking status and drinking status. Correlation analysis indicated that the frequency of MN was positively associated with MDA levels (p < 0.05). Altogether, these results support the detrimental effects of chronic low dose radiation in humans, which involves the induction of oxidative stress and chromosomal damage. [ABSTRACT FROM AUTHOR]
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- 2020
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15. Correction to: Functional analysis of GhCHS, GhANR and GhLAR in colored fiber formation of Gossypium hirsutum L.
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Gao, Jianfang, Shen, Li, Yuan, Jingli, Zheng, Hongli, Su, Quansheng, Yang, Weiguang, Zhang, Liqing, Nnaemeka, Vitalis Ekene, Sun, Jie, Ke, Liping, and Sun, Yuqiang
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COTTON , *COTTON quality , *FUNCTIONAL analysis , *FIBERS - Abstract
In the original publication of this article [1], the authors pointed out the Fig. 4b was same with Fig. 4c. The correct Fig. 4b should be below. [ABSTRACT FROM AUTHOR]
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- 2020
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16. Functional analysis of GhCHS, GhANR and GhLAR in colored fiber formation of Gossypium hirsutum L.
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Gao, Jianfang, Shen, Li, Yuan, Jingli, Zheng, Hongli, Su, Quansheng, Yang, Weiguang, Zhang, Liqing, Nnaemeka, Vitalis Ekene, Sun, Jie, Ke, Liping, and Sun, Yuqiang
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COTTON quality , *COTTON , *COTTON fibers , *FUNCTIONAL analysis , *NATURAL fibers , *CHALCONE synthase - Abstract
Background: The formation of natural colored fibers mainly results from the accumulation of different anthocyanidins and their derivatives in the fibers of Gossypium hirsutum L. Chalcone synthase (CHS) is the first committed enzyme of flavonoid biosynthesis, and anthocyanidins are transported into fiber cells after biosynthesis mainly by Anthocyanidin reductase (ANR) and Leucoanthocyanidin reductase (LAR) to present diverse colors with distinct stability. The biochemical and molecular mechanism of pigment formation in natural colored cotton fiber is not clear. Results: The three key genes of GhCHS, GhANR and GhLAR were predominantly expressed in the developing fibers of colored cotton. In the GhCHSi, GhANRi and GhLARi transgenic cottons, the expression levels of GhCHS, GhANR and GhLAR significantly decreased in the developing cotton fiber, negatively correlated with the content of anthocyanidins and the color depth of cotton fiber. In colored cotton Zongxu1 (ZX1) and the GhCHSi, GhANRi and GhLARi transgenic lines of ZX1, HZ and ZH, the anthocyanidin contents of the leaves, cotton kernels, the mixture of fiber and seedcoat were all changed and positively correlated with the fiber color. Conclusion: The three genes of GhCHS, GhANR and GhLAR were predominantly expressed early in developing colored cotton fibers and identified to be a key genes of cotton fiber color formation. The expression levels of the three genes affected the anthocyanidin contents and fiber color depth. So the three genes played a crucial part in cotton fiber color formation and has important significant to improve natural colored cotton quality and create new colored cotton germplasm resources by genetic engineering. [ABSTRACT FROM AUTHOR]
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- 2019
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17. Transcriptomics profiling reveal the heterogeneity of white and brown adipocyte.
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Zhang, Zhongxiao, Xu, Liling, Zhang, Ling, Lu, Jingxian, Peng, Zhou, Guo, Xirong, and Gao, Jianfang
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ADIPOGENESIS , *FAT cells , *FOCAL adhesions , *OXIDATIVE phosphorylation , *HETEROGENEITY , *SOX transcription factors - Abstract
The marker genes associated with white adipocytes and brown adipocytes have been previously identified; however, these markers have not been updated in several years, and the differentiation process of preadipocytes remains relatively fixed. Consequently, there has been a lack of exploration into alternative differentiation schemes. In this particular study, we present a transcriptional signature specific to brown adipocytes and white adipocytes. Notably, our findings reveal that ZNF497, ZIC1, ZFY, UTY, USP9Y, TXLNGY, TTTY14, TNNT3, TNNT2, TNNT1, TNNI1, TNNC1, TDRD15, SOX11, SLN, SFRP2, PRKY, PAX3KLHL40, PAX3, INKA2-AS1, SOX11, and TDRD15 exhibit high expression levels in brown adipocytes. XIST, HOXA10, PCAT19, HOXA7, PLSCR3, and AVPR1A exhibited high expression levels in white adipocytes, suggesting their potential as novel marker genes for the transition from white to brown adipocytes. Furthermore, our analysis revealed the coordinated activation of several pathways, including the PPAR signaling pathway, focal adhesion, retrograde endocannabinoid signaling, oxidative phosphorylation, PI3K-Akt signaling pathway, and thermogenesis pathways, in brown adipocytes. Moreover, in contrast to prevailing culture techniques, we conducted a comparative analysis of the differentiation protocols for white preadipocytes and brown preadipocytes, revealing that the differentiation outcome remained unaffected by the diverse culture schemes employed. However, the expression levels of certain marker genes in both adipocyte types were found to be altered. This investigation not only identified potential novel marker genes for adipocytes but also examined the impact of different differentiation methods on preadipocyte maturation. Consequently, these findings offer significant insights for further research on the differentiation processes of diverse adipocyte subtypes. [ABSTRACT FROM AUTHOR]
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- 2023
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18. Unconditional stability analysis of Grünwald Letnikov method for fractional-order delay differential equations.
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Yao, Zichen, Yang, Zhanwen, and Gao, Jianfang
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DELAY differential equations , *NUMERICAL analysis , *HEAT equation , *CAPUTO fractional derivatives , *ANALYTICAL solutions - Abstract
In this paper, we investigate the unconditional stability and the generally unconditional stability of the Grünwald Letnikov method for fractional-order delay differential equations (FDDEs), which is the generalization of P -stability and G P -stability for classical integer-order delay differential equations. Using the Z -transform, an equivalent form of the discrete Laplace transform, we first show the unconditional stability of the Grünwald Letnikov method for any delay and any constraint mesh. Secondly, we also derive the generally unconditional stability of the Grünwald Letnikov method with a linear interpolation for approximating the delay term under a general uniform mesh. It is shown that the Grünwald Letnikov method for FDDEs preserves the stability for the analytical solution and hence naturally inherits the α -dependence. Finally, two numerical examples for FDDEs and time fractional-order diffusion equations with delay are presented to demonstrate the validity and effectiveness of theoretical results. • We establish a general framework of the numerical stability analysis for FDDEs. • The unconditional and general unconditional numerical stability of Grunwald Letnikov method are established. • Our results generalize the P-stability and GP-stability for classical DDEs. • We prove that the Grunwald Letnikov method for FDDEs preserves the stability and hence naturally inherit the α -dependence. [ABSTRACT FROM AUTHOR]
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- 2023
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19. Differences in the metabolic profiles of brown and white adipocytes based on secretomics.
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Zhang, Zhongxiao, Liao, Xiangpeng, Guo, Xirong, and Gao, Jianfang
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JAK-STAT pathway , *ADIPOKINES , *FAT cells - Abstract
Brown adipocytes and white adipocytes play important roles in systemic metabolism and energy homeostasis. Recent studies have demonstrated that white adipocytes and brown adipocytes secrete numerous adipokines and thus act as endocrine cells. However, differences in the metabolites secreted from white adipocytes and brown adipocytes have never been reported. In this study, we assessed the metabolites secreted from white adipocytes and brown adipocytes. In total, the levels of 47 metabolites in brown adipocytes were significantly different from those in white adipocytes, with 31 high and 16 low in brown adipocytes as compared with those in white adipocytes. We classified these secreted metabolites as amino acids and peptides, fatty acids, and conjugates, glycerophosphocholines, furanones, and trichloroacetic acids. In addition, we identified the glycerophospholipid metabolism activated in white adipocytes, and these differentially expressed metabolites were associated with the mitogen-activated protein kinase pathway and Janus kinase-signal transducer and activator of transcription signaling pathway according to the Ingenuity Pathway Analysis (IPA) software analysis. This study revealed novel metabolites secreted from brown adipocytes and white adipocytes, and these metabolites from adipocytes may perform specific biological functions based on the type of adipocyte that secretes them, and this forms the material basis of the interaction between adipocytes and other cells. • Differences in the metabolites secreted from white adipocytes and brown adipocytes. • 47 metabolites in brown adipocytes different from those in white adipocytes. • We revealed the material basis of the interaction between adipocytes and other cells. [ABSTRACT FROM AUTHOR]
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- 2023
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20. Methionine sulfoxide suppresses adipogenic differentiation by regulating the mitogen‐activated protein kinase signaling pathway.
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Qin, Dani, Lei, Yong, Xie, Wen, Zheng, Qiuju, Peng, Zhou, Liu, Yiwen, Dai, Biao, Ma, Tieliang, Wei, Ping, Gao, Chunlin, Guo, Xirong, Gao, Jianfang, Zhao, Jing, Du, Juan, Zeng, Qianyi, Zhang, Zhongxiao, Dong, Xiaohua, and Shen, Huiping
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ADIPOGENESIS , *MITOGEN-activated protein kinases , *PEROXISOME proliferator-activated receptors , *CELLULAR signal transduction , *CARRIER proteins , *METHIONINE , *SULFOXIDES , *PROTEIN expression - Abstract
In this study, methionine sulfoxide (MetO) was identified as an active metabolite that suppresses adipogenesis after screening obese individuals versus the normal population. MetO suppressed the gene and protein expression of CCAAT/enhancer binding protein (C/EBP) α, adipocyte fatty acid binding protein 4 (FABP4), and the nuclear receptor peroxisome proliferator‐activated receptor γ (PPARγ) during human preadipocyte (HPA) differentiation. Adipogenesis decreased following MetO treatment; however, the preadipocyte number, proliferation, and apoptosis were unaffected. The activity of phosphorylated extracellular signal‐related kinase (P‐ERK) of the mitogen‐activated protein kinase (MAPK) pathway was significantly inhibited in HPA after MetO treatment. Furthermore, treatment of preadipocytes with the selective P‐ERK1/2 agonist Ro 67‐7476 abolished the effect of MetO against adipogenesis suggesting that MetO function is dependent on the MAPK pathway. The mechanistic insights of adipogenesis suppression by MetO presented in this study shows its potential as an antiobesity drug. [ABSTRACT FROM AUTHOR]
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- 2023
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21. Strong superconvergence of the Euler–Maruyama method for linear stochastic Volterra integral equations.
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Liang, Hui, Yang, Zhanwen, and Gao, Jianfang
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FUNCTIONAL analysis , *NUMERICAL analysis , *INTEGRAL equations , *STOCHASTIC convergence - Abstract
The Euler–Maruyama method is presented for linear stochastic Volterra integral equations. Then the strong convergence property is analyzed for convolution kernels and general kernels, respectively. It is well known that for stochastic ordinary differential equations, the strong convergence order of the Euler–Maruyama method is 1 2 . However, the strong superconvergence order of 1 is obtained for linear stochastic Volterra integral equations with convolution kernels if the kernel K 2 of the diffusion term satisfies K 2 ( 0 ) = 0 ; and this strong superconvergence property is inherited by linear stochastic Volterra integral equations with general kernels if the kernel K 2 of the diffusion term satisfies K 2 ( t , t ) = 0 . The theoretical results are illustrated by extensive numerical examples. [ABSTRACT FROM AUTHOR]
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- 2017
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22. Metabolomic analysis reveals macrophage metabolic reprogramming and polarization under different nutritional cues.
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Zhang, Zhongxiao, Peng, Zhou, Wang, Rui, Guo, Xirong, and Gao, Jianfang
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METABOLIC reprogramming , *METABOLOMICS , *METABOLIC disorders , *MACROPHAGES , *MACROPHAGE activation , *FAT - Abstract
• Obesity-induced chronic inflammation and metabolic abnormalities are highly relevant to the functional dysregulation of macrophages, especially under obese conditions. • We employed metabolomic approaches to examine the metabolic responses of macrophages to high glucose, high fat and their coexistence, aiming to delineate the molecular mechanisms of nutritional factors on macrophage activation and obesity-related diseases from a metabolic perspective. • Our findings revealed that different nutritional conditions could reprogram key metabolism in macrophages. • We identified a metabolite derived from macrophages, Long-Chain Phosphatidylcholine (LPC), which exerts beneficial effects on obese mice. • This finding reveals a potential dialogue mechanism between macrophages and adipocytes. Obesity-induced chronic inflammation and metabolic abnormalities are highly relevant to the functional dysregulation of macrophages, especially under obese conditions. Hyperglycemia and hyperlipidemia, central to obesity, directly alter macrophage activity. However, the impacts of different nutritional cues on the intricate metabolic networks in macrophages remain unclear. In this study, we employed metabolomic approaches to examine the metabolic responses of macrophages to high glucose, high fat and their coexistence, aiming to delineate the molecular mechanisms of nutritional factors on macrophage activation and obesity-related diseases from a metabolic perspective. Our findings revealed that different nutritional conditions could reprogram key metabolism in macrophages. Additionally, we identified a metabolite derived from macrophages, Long-Chain Phosphatidylcholine (LPC), which exerts beneficial effects on obese mice. It ameliorates the obesity phenotype and improves glucose metabolism profiles. This discovery suggests that LPC has a significant therapeutic potential in the context of obesity-induced metabolic dysfunctions. Our study unveils the metabolic phenotype of macrophages in high-fat and high-sugar environments and uncovers a macrophage-derived metabolite that significantly ameliorates the obesity phenotype. This finding reveals a potential dialogue mechanism between macrophages and adipocytes, shedding light on the complex interplay of immune and metabolic systems in obesity. This discovery not only enhances our understanding of obesity's underlying mechanisms but also opens up new avenues for therapeutic interventions targeting macrophage-adipocyte interactions. [ABSTRACT FROM AUTHOR]
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- 2024
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23. Anti-adipogenesis effect of indole-3-acrylic acid on human preadipocytes and HFD-induced zebrafish.
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Zhang, Ling, Zhao, Jing, Peng, Zhou, Zhang, Zhongxiao, Huang, Shan, Dong, Xiaohua, Gao, Jianfang, and Guo, Xirong
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Background: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.Aims: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.Methods: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.Results: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.Conclusions: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity.Graphic Abstract: Obesity, defined as excessive or abnormal body fat accumulation, which could significantly increase the risk of cardiovascular disease, type 2 diabetes mellitus (T2DM) diseases and seriously affect people’s quality of life. More than 2 billion people are overweight, and the incidence of obesity is increasing rapidly worldwide, it has become a widely concerned public health issue in the world. Diverse evidence show that active metabolites are involved in the pathophysiological processes of obesity.However, whether the downstream catabolite of tryptophan, 3-indole acrylic acid (IA), is involved in obesity remains unclear.We collected the samples of serum from peripheral blood of obesity and health controls, and liquid chromatography–mass spectrometry (LC-MS) was performed to identify the plasma levels of IA. Additionally, we verified the potential benefits of IA on human preadipocytes and HFD- induced zebrafish by cell viability assay, flow cytometry assay, Oil red O staining, total cholesterol (T-CHO), triglyceride (TG) and nonesterified free fatty acids (NEFA) measurements and Nile Red staining. RNA-Seq, functional analysis and western blot revealed the mechanisms underlying the function of IA.We found that the content of IA in peripheral blood serum of overweight people was significantly lower than that of normal people. In addition, supplementation with IA in zebrafish larvae induced by a high fat diet (HFD) dramatically reduced HFD induced lipid accumulation. IA had no effect on proliferation and apoptosis of preadipocytes, but significantly inhibited adipogenesis of preadipocytes by down-regulate CEBPα and PPARγ. RNA-Seq and functional analysis revealed that IA regulated the adipogenesis of preadipocytes through stimulate the phosphorylation of STAT1.Taken together, IA has been identified as a potent metabolite for the prevention or treatment of obesity. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
24. Monitoring glacial shrinkage using remote sensing and site-observation method on southern slope of Kalik Mountain, eastern Tian Shan, China.
- Author
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Wang, Wenbin, Li, Kaiming, and Gao, Jianfang
- Subjects
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GLACIERS , *REMOTE-sensing images , *RUNOFF , *CLIMATE change , *ENVIRONMENTAL degradation - Abstract
Currently, one of the effective means in monitoring glacier change in regional scale is remote sensing and site-observation method. In this article, we present a study of comparing glacier area in 2005 derived from SPOT5 satellite image with area in 1972 derived from topographic maps. Moreover, Miaoergou (庙儿沟) flat-summit glacier is site observed to verify glacial change in regional scale. During the study period, glaciers located in the southern slope of Kalik (喀尔里克) Mountain reduced their area by 12.3%. The high individual change indicates that the wastage corresponding to area changes has been the dominant process of glacier mass loss in this region. Glaciers smaller than the mean size (1.3 km), especially those <0.5 km, lost more of their area with high variability and yielding two glaciers vanished. It is suggested that small glaciers are prone to disappear under such climate conditions in future years. With the difference supplied by upstream glaciers, there appears great disparity trend of river runoff recently. Seen from decade-scale, the discharge, the lower glacier-covered catchment, is decreased because of strong consumption of small glaciers during the past decades. Owing to the rivers that are supplied by more meltwater from medium and larger glaciers mainly, the trend of the river runoff increase is still going on. Trends of river runoff of three different glacier-covered catchments exhibit distinctive results. This implies that retreating glaciers will reduce the ability to regulate the water circulation. [ABSTRACT FROM AUTHOR]
- Published
- 2011
- Full Text
- View/download PDF
25. Serum matrix metalloproteinase-13 as a diagnostic biomarker for cutaneous squamous cell carcinoma.
- Author
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Wang, Hui, Li, Hong, Yan, Qingtao, Gao, Sumei, Gao, Jianfang, Wang, Zhenhua, and Sun, Yi
- Subjects
- *
SQUAMOUS cell carcinoma , *BIOMARKERS , *MATRIX metalloproteinases , *SENSITIVITY & specificity (Statistics) , *RECEIVER operating characteristic curves , *ESOPHAGEAL cancer - Abstract
Background: A significant proportion of newly diagnosed patients with cutaneous squamous cell carcinoma (cSCC) have metastasis and eventually die of the disease, necessitating the exploration of novel biomarkers for early detection of cSCC aggressiveness, risk assessment and monitoring. Matrix metalloproteinase-13 (MMP-13) has been implicated in cSCC pathogenesis. Serum MMP-13 levels have been shown to predict survival in patients with esophageal SCC, but their diagnostic value for cSCC has not been explored.Methods: We conducted a case-control study to examine serum MMP-13 as a biomarker for cSCC. Patients with cSCC undergoing surgical resection and health controls undergoing plastic surgery were recruited. ELISA for measurement of serum MMP-13 and immunohistochemistry for detection of tissue MMP-13 were performed, and the results were compared between the case and the control group, and among different patient groups. ROC curve analysis was performed to determine the diagnostic value of serum MMP-13 levels.Results: The ratio of male to female, and the age between the case (n = 77) and the control group (n = 50) were not significantly different. Patients had significantly higher serum MMP-13 levels than healthy controls. Subjects with stage 3 cSCC had markedly higher serum MMP-13 levels than those with stage 1 and stage 2 cSCC. Patients with invasive cSCC had remarkably higher serum MMP-13 than those with cSCC in situ. Post-surgery serum MMP-13 measurement was done in 12 patients, and a significant MMP-13 decrease was observed after removal of cSCC. Tumor tissues had a remarkably higher level of MMP-13 than control tissues. Serum MMP-13 predicted the presence of invasive cSCC with an AUC of 0.87 (95% CI [0.78 to 0.95]) for sensitivity and specificity of 81.7 and 82.4%, respectively for a cut-off value of 290 pg/mL. Serum MMP-13 predicted lymph node involvement with an AUC of 0.94 (95% CI [0.88 to 0.99]) for sensitivity and specificity of 93.8 and 88.5%, respectively for a cut-off value of 430 pg/mL.Conclusion: Serum MMP-13 might serve as a valuable biomarker for early detection of cSCC invasiveness and monitoring of cSCC progression. [ABSTRACT FROM AUTHOR]- Published
- 2021
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- View/download PDF
26. Theoretical and numerical analysis of the Euler–Maruyama method for generalized stochastic Volterra integro-differential equations.
- Author
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Zhang, Wei, Liang, Hui, and Gao, Jianfang
- Subjects
- *
NUMERICAL analysis , *STOCHASTIC analysis , *VOLTERRA equations , *INTEGRO-differential equations , *STOCHASTIC difference equations , *CONTINUITY - Abstract
In this paper, we concern with the theoretical and numerical analysis of the generalized stochastic Volterra integro-differential equations (SVIDEs). The existence, uniqueness, boundedness and Hölder continuity of the analytic solutions for generalized SVIDEs are investigated. The Euler–Maruyama method for generalized SVIDEs is presented. The boundedness of the numerical solution is proved, and the strong convergence order is obtained. The theoretical results are illustrated by some numerical examples. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. Correlation between the Expression of PD-L1 and Clinicopathological Features in Patients with Thymic Epithelial Tumors.
- Author
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Chen, Yanmei, Zhang, Yuping, Chai, Xiaoling, Gao, Jianfang, Chen, Guorong, Zhang, Weifen, and Zhang, Yunxiang
- Subjects
- *
AUTOPHAGY , *CANCER , *CHI-squared test , *GENE expression , *IMMUNOHISTOCHEMISTRY , *PROBABILITY theory , *PROTEINS , *TUMOR classification , *TREATMENT effectiveness , *THYMOMA ,EPITHELIAL cell tumors - Abstract
The incidence of thymic epithelial tumors (TETs) in the Chinese population was much higher than that in the North American population. In clinical treatment, the prognosis of benign tumors after surgical resection was significantly better than that of malignant tumors. Currently, the commonly used clinical indicators for TET staging included Masaoka staging and WHO (2015) pathological criteria; however, the distinction between the benign and malignant tumors and diagnosis is yet to be explored. The current study demonstrated that the expression of PD-L1 in tumor cells was correlated with the degree of TET malignancy. The quantitative analysis of PD-L1 expression in 70 cases of TET tumor samples revealed that the positive rate of PD-L1 expression in types A, AB, B1, and B2 of thymoma (40 cases) was 37.5% (15/40), which was significantly lower than that in type B3 thymoma and thymic carcinoma (76.67%, 30 cases, 23/30) as demonstrated by chi-square test (P<0.05). In addition, the two methods were analyzed for the quantitative detection of PD-L1 expression. The results from the estimation of transcriptional RNA expression and quantitative protein immunohistochemistry were consistent (r=0.745). Furthermore, we also analyzed PD-L1 expression level in different types of TETs from TCGA database and observed that higher PD-L1 expression was in thymic carcinoma than in thymoma. Therefore, it could be concluded that PD-L1 expression in TET cells was correlated with the degree of malignancy, whereas the estimation of PD-L1 expression was potentially applicable in the clinical staging of TETs. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
28. Mitochondrial Biomarkers Reflect Semen Quality: Results from the MARCHS Study in Chongqing, China.
- Author
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Zhang, Guowei, Wang, Zhi, Ling, Xi, Zou, Peng, Yang, Huan, Chen, Qing, Zhou, Niya, Sun, Lei, Gao, Jianfang, Zhou, Ziyuan, Cao, Jia, and Ao, Lin
- Subjects
- *
INFERTILITY , *SEMEN analysis , *BIOMARKERS , *MALE reproductive health , *DIAGNOSIS - Abstract
Unexplained infertility requires that more sensitive and mechanism-based biomarkers should be developed and used independently of or in addition to conventional semen parameters for an infertility diagnosis. In the present study, semen samples were collected from young men participating in the Male Reproductive Health in Chongqing College students (MARCHS) cohort study in the follow-up stage in 2014. Conventional semen parameters were measured in all 656 participants, whereas sperm mitochondrial membrane potential (MMP), mitochondrial DNA copy number (mtDNAcn), mtDNA integrity and apoptotic parameters were measured among 627, 386, 362, and 628 participants, respectively. We found that sperm MMP was significantly positively correlated with all of conventional semen parameters including semen volume (r = 0.090, p = 0.025), sperm concentration (r = 0.301, p<0.01), total sperm count (r = 0.324, p<0.01), and progressive motility (r = 0.399, p<0.01); sperm MMP was also negatively correlated with Annexin V+ sperm (r = -0.553, p<0.01); mtDNAcn was significantly negatively correlated with sperm concentration (r = -0.214, p<0.01), total sperm count (r = -0.232, p<0.01), and progressive motility (r = -0.164, p = 0.01); mtDNA integrity was also significantly positively correlated with sperm concentration (r = 0.195, p<0.01), total sperm count (r = 0.185, p<0.01), and progressive motility (r = 0.106, p = 0.043). After adjusting for potential confounders, these relationships remained significant. Furthermore, we explored the potential effects of lifestyles on such mitochondrial biomarkers and found that the current drinkers displayed a higher level of sperm MMP; additionally, mt DNAcn was increased with age. The results indicated that certain mitochondrial biomarkers could serve as predictors of semen quality in a general population, and the study provides a baseline for the effects of population characteristics and lifestyles on such mitochondrial markers. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
29. The p-eIF2α/ATF4 pathway links endoplasmic reticulum stress to autophagy following the production of reactive oxygen species in mouse spermatocyte-derived cells exposed to dibutyl phthalate.
- Author
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Zhang, Guowei, Ling, Xi, Liu, Kaijun, Wang, Zhi, Zou, Peng, Gao, Jianfang, Cao, Jia, and Ao, Lin
- Subjects
- *
ENDOPLASMIC reticulum , *AUTOPHAGY , *REACTIVE oxygen species , *LABORATORY mice , *DIBUTYL phthalate - Abstract
Dibutyl phthalate (DBP) is a widely used plasticizer that has been shown to induce germ cell apoptosis-related testicular atrophy and cause reproductive toxicity. Our previous results indicated that endoplasmic reticulum (ER) stress-activated autophagy served as a self-defense mechanism against DBP-induced germ cell apoptosis. However, the specific pathways that link ER stress and autophagy remain unclear. Here, we showed that exposure to DBP enhanced autophagic flux in mouse spermatocyte-derived GC-2 cells and that the eukaryotic translation initiation factor 2/activating transcription factor 4 pathway mediated ER stress-related autophagy independent of the mTOR and Beclin-1 pathways. Moreover, we demonstrated that DBP treatment led to the generation of reactive oxygen species (ROS) and that the inhibition of ROS by melatonin abrogated both ER stress and autophagy. The results indicated that excessive ROS production might be involved in DBP-induced ER stress and autophagy in GC-2 cells. Thus, ROS may serve as upstream mediators of ER stress and autophagy in DBP-treated GC-2 cells. [ABSTRACT FROM PUBLISHER]
- Published
- 2016
- Full Text
- View/download PDF
30. DBP-induced endoplasmic reticulum stress in male germ cells causes autophagy, which has a cytoprotective role against apoptosis in vitro and in vivo.
- Author
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Zhang, Guowei, Liu, Kaijun, Ling, Xi, Wang, Zhi, Zou, Peng, Wang, Xiaogang, Gao, Jianfang, Yin, Li, Zhang, Xi, Liu, Jinyi, Ao, Lin, and Cao, Jia
- Subjects
- *
DIBUTYL phthalate , *ENDOPLASMIC reticulum , *GERM cells , *AUTOPHAGY , *APOPTOSIS , *SPERMATOGENESIS , *ATROPHY - Abstract
Recently, spermatogenic cell apoptosis was shown to play a key role in the induction of testicular atrophy by dibutyl phthalate (DBP), thus causing reproductive toxicology. However, the molecular events induced by DBP in apoptotic germ cells remain unclear. In the present study, the mouse spermatocyte-derived GC-2 cell line was exposed to different doses of DBP. We found that DBP induced marked apoptosis in GC-2 cells. The levels of the major endoplasmic reticulum (ER) stress markers GRP-78, ATF-6, and p-EIF2α were elevated when GC-2 cells were exposed to 25 μM DBP and increased in a dose-dependent manner at higher concentrations. Furthermore, at a concentration that resulted in significant apoptosis (100 μM), CHOP, which plays a convergent role in ER stress-mediated apoptosis and is regulated by various upstream ER stress signals, was activated and partially contributed to the DBP-induced apoptosis. However, inhibition of ER stress by 4-PBA, a chemical with chaperone-like activities, augmented the GC-2 cell apoptosis induced by DBP. Further experiments demonstrated that DBP-induced ER stress additionally had a protective role, mediated through the activation of autophagy. These results were confirmed in prepubertal rat testis germ cells; DBP treatment significantly induced testicular atrophy, accompanied by apoptosis, ER stress, and autophagy. Inhibition of ER stress and autophagy significantly aggravated the DBP-induced damage to the germ cells and testes. Taken together, our data suggest that DBP-induced ER stress in germ cells has a cytoprotective effect that is mediated through autophagy activation. These findings provide novel clues regarding the molecular events involved in DBP-induced germ cell apoptosis. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
31. The Effect of Thermo-Chemical Treatment on the Water Resistance of Defatted Soybean Flour-Based Wood Adhesive.
- Author
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Zhang, Binghan, Li, Jin, Kan, Yufei, Gao, Jianfang, Zhang, Yuehong, and Gao, Zhenhua
- Subjects
- *
ADHESIVES , *SODIUM dodecyl sulfate , *CROSSLINKING (Polymerization) , *POLYAMIDES , *VISCOSITY , *SOYBEAN - Abstract
The aim of this study was to effectively improve the water resistance of a defatted soybean flour (DSF)-based adhesive by subjecting DSF to thermo-chemical treatment in the presence of sodium dodecyl sulfate (SDS), and then the crosslinking with epichlorohydrin-modified polyamide (EMPA). The effect of thermo-chemical treatment on the structures and properties of the DSF and DSF-based adhesive were investigated by plywood evaluation, boiling-water-insoluble content, and acetaldehyde value measurements, as well as FTIR, X-ray photoelectron spectroscopic (XPS), X-ray diffraction spectroscopy (XRD), thermogravimetric analysis (TGA), and rheology analyses. The test results revealed that the water resistance of the DSF-based adhesive was significantly improved, attributed to the formation of a solid three-dimensional crosslinked network structure resulted from the repolymerization of DSF, the Maillard reaction between the protein and carbohydrate, and chemical crosslinking between the crosslinker and DSF. Moreover, SDS destroyed the hydrophobic interactions within protein and inhibited macromolecular aggregations during the thermal treatment. Therefore, more reactive groups buried within the globular structure of the soybean protein component of DSF could be released, which supported the repolymerization, Maillard reaction, and chemical crosslinking of DSF, thereby leading to an improved crosslinking density of the cured DSF-based adhesive. In addition, the adhesive composed of thermo-chemically treated DSF and EMPA exhibited preferable viscosity and viscosity stability suitable for the production of wood composites. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
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