14 results on '"Xu, Po"'
Search Results
2. A Current Control Method for Grid-Connected Inverters.
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Zhang, Wenping, Wang, Yiming, Xu, Po, Li, Donghui, and Liu, Baosong
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DYNAMIC stability , *DYNAMICAL systems , *MATHEMATICAL models , *ELECTRIC inverters - Abstract
It is simple to implement conventional current control with a proportional integral (PI) controller. However, system stability and dynamic performance are not perfect, particularly when operating under unfavorable conditions. In this paper, an improved control method is proposed by introducing a compensation unit. The compensation unit can effectively compensate the system's phase around the crossover frequency, greatly enhancing the system's phase margin and stability. It is also capable of handling weak-grid conditions. In this paper, the concept of the proposed compensation unit is explained first. Then, the corresponding mathematical model for the current control loop is built, and system bode diagrams for the conventional and proposed methods are compared. Furthermore, the effect of the parameters for the compensation unit is investigated, and an optimization method is proposed to determine optimal parameters. In addition, to handle weak-grid conditions, the proposed scheme is expanded by including the compensation unit in the grid's feed-forward loop. Finally, an experimental platform is constructed, and the experimental results are presented to validate the proposed method. [ABSTRACT FROM AUTHOR]
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- 2023
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3. Evaluation and Improvement of Backup Capacity for Household Electric Vehicle Uninterruptible Power Supply (EV-UPS) Systems.
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Zhang, Wenping, Wang, Yiming, Xu, Po, Li, Donghui, and Liu, Baosong
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UNINTERRUPTIBLE power supply , *ELECTRIC capacity , *RURAL geography - Abstract
The use of electric vehicles (EVs) for household uninterruptible power supplies (UPSs), particularly in rural areas, can greatly improve household power reliability. However, because EVs are mobile, the evaluation of backup capacity for EV-UPS systems is completely different when compared to traditional UPSs. As a result, the focus of this paper is on the evaluation and improvement of backup capacity for EV-UPS systems. The architectures for EV-UPS systems are presented first. The methodology for calculating backup capacity for EV-UPS systems is then presented, followed by four detailed cases based on different grid failure times. Furthermore, the impact of system operating parameters on backup capacity, such as different load power, EV mobility pattern parameters, and grid outage durations, is investigated. The results of backup capacity in cases of different operating parameters are detailed using an EV mobility model. An improved strategy for increasing backup capacity is proposed, in which more backup energy can be released during a power outage. Meanwhile, the next trip requirement is unaffected. The backup capacity with the improved strategy is then calculated and compared to the results with the traditional strategy. Finally, a 5 kW EV-UPS experimental platform is constructed, and the experimental results are presented to validate the proposed method. [ABSTRACT FROM AUTHOR]
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- 2023
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4. MicroRNA-15a promotes prostate cancer cell ferroptosis by inhibiting GPX4 expression.
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Xu, Po, Wang, Ying, Deng, Zhe, Tan, Zhibo, and Pei, Xiaojuan
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PROSTATE cancer , *ANDROGEN receptors , *CANCER cells , *REVERSE transcriptase polymerase chain reaction , *WESTERN immunoblotting , *LACTATE dehydrogenase - Abstract
Ferroptosis is a novel form of regulated cell death characterized by accumulated lipid reactive oxygen species (ROS) and inactivation of glutathione peroxidase 4 (GPX4). The present study aimed to investigate the role of microRNA (miRNA/miR)-15a in ferroptosis of prostate cancer cells. Bioinformatics analysis was performed to predict the potential interaction between miR-15a and the 3′-untranslated region (UTR) of GPX4 mRNA. The prostate cancer cell line, LNCAP was transfected with miR-15a mimics or small interfering (si)-GPX4. Reverse transcription-quantitative PCR and western blot analyses were performed to detect the mRNA and protein expression levels of GPX4, respectively. Biotin-RNA pull-down and dual-luciferase reporter assays were performed to verify the interaction between miR-15a and GPX4 mRNA. The Cell Counting Kit-8 assay was performed to assess cell proliferation, while lactate dehydrogenase (LDH) and intracellular ferrous iron levels were detected via ELISA. Lipid ROS and mitochondrial membrane potential (MMP) were assessed via flow cytometry and staining with C11-BIODIPY probes or JC-1. Furthermore, lipid peroxidation was identified by measuring malondialdehyde (MDA) levels. The results demonstrated that transfection with miR-15a mimics decreased GPX4 protein expression. Bioinformatics analysis revealed potential binding sites between miR-15a and the 3′-UTR region of GPX4, and RNA pull-down and the dual-luciferase reporter assays further confirmed the interaction between miR-15a and GPX4 mRNA. Both transfection with miR-15a mimics and si-GPX4 suppressed cell proliferation, elevated LDH release, accumulated intracellular ferrous iron and ROS, disrupted MMP and increased MDA levels. Taken together, the results of the present study suggest miR-15a induces ferroptosis by regulating GPX4 in prostate cancer cells, which provides evidence for investigating the therapeutic strategies of prostate cancer. [ABSTRACT FROM AUTHOR]
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- 2022
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5. Increased serum aminotransferases associated with anti-mitochondrial antibodies in systemic lupus erythematosus patients with autoimmune liver disease
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Li, Cheng-Hai, Xu, Po-Shi, Wang, Chun-Yan, and Zou, Guo-Lin
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SYSTEMIC lupus erythematosus , *AMINOTRANSFERASES , *AUTOIMMUNE diseases , *BLOOD plasma - Abstract
Abstract: Background: Serum aminotransferase activities are increased in many liver diseases, but the causes for the elevation might be difficult to determine. Whether the elevation of aminotransferases correlates with anti-mitochondrial antibodies (AMA) in systemic lupus erythematosus (SLE) patients with autoimmune liver disease deserves further consideration. Methods: A meticulous review was done in a large SLE cohort searching for laboratory features of the presence of AMA. Forty-eight hospitalized SLE patients with AMA and 60 randomly selected SLE patients without AMA as a matched case control were enrolled into the retrospective study. Laboratory data were collected, analyzed and compared in SLE patients with and without AMA. Results: Serum activities of aminotransferases were significantly increased in the 48 SLE patients with AMA compared with the 60 subjects without AMA. Meanwhile, we found a positive correlation between serum AMA titers and serum aminotransferase activities. Conclusion: Although much remains to be learned about the pathogenesis of autoimmune liver disease associated with AMA, it is possible to suggest that AMA might contribute to the elevation of aminotransferases in SLE patients with the progressive disease. [Copyright &y& Elsevier]
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- 2006
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6. Shenfu injection prevents sepsis-induced myocardial injury by inhibiting mitochondrial apoptosis.
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Xu, Po, Zhang, Wen-Qing, Xie, Jing, Wen, Ying-Shi, Zhang, Guo-Xing, and Lu, Shi-Qi
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MYOCARDIAL infarction risk factors , *ANIMAL experimentation , *APOPTOSIS , *B cell lymphoma , *EDEMA , *ELECTRON microscopy , *HERBAL medicine , *INJECTIONS , *CHINESE medicine , *MICE , *MITOCHONDRIA , *NECROSIS , *SEPSIS , *WESTERN immunoblotting , *TREATMENT effectiveness , *DESCRIPTIVE statistics , *DISEASE complications - Abstract
Shenfu injection (SFI) is a well-known Chinese herbal medicine widely used in the treatment of septic shock in China. The aims of this study are to investigate the protective effects of SFI on sepsis-induced myocardial injury in mice and to identify the underlying mechanism of action. Seventy-two male C57/B6J mice (5–6 weeks old) were randomly divided into five groups: control (NC), sham sepsis (sham), sepsis (Lipopolysaccharide- LPS), sepsis treated with a low dose SFI, and sepsis treated with a high dose SFI. Sepsis was induced in mice by intraperitoneal injection of LPS. Myocardial tissue samples were collected from different groups at 6 h, 12 h, and 24 h post-LPS injection. Myocardial injury was examined using hematoxylin-eosin (H&E) and TUNEL staining. Western-blot analysis was performed to determine the protein expression of B-cell lymphoma 2 (Bcl-2), BH3 interacting-domain death agonist (Bid), truncated-Bid (t-Bid) and caspase-9 in all the groups. Moreover, the structural changes in the mitochondria of cardiomyocytes were also observed by transmission electron microscopy. H&E staining revealed structural damage, local necrosis, interstitial edema, inflammatory cell infiltration and vacuolar changes in the myocardial tissue in the sepsis (LPS) group; almost intact myocardial tissue was observed in the high dose SFI group with improvements in interstitial edema and inflammatory cell infiltration. We observed that LPS-induced cardiomyocyte apoptosis was significantly improved with high dose SFI as compared with sepsis (LPS) group (P ˂ 0.05). LPS was found to decrease the protein expression of Bcl-2 and increase the level of Bid, t-Bid and caspase-9. Treatment with SFI significantly increased the Bcl-2 protein expression (P ˂ 0.05) and decreased the protein expression of Bid, t-Bid and caspase-9 as compared with LPS group (P ˂ 0.05). Markedly swollen myocardial mitochondria with partial vacuolation were observed in LPS treated mice while SFI treatment was found to significantly improve the LPS-induced morphological damage of the mitochondria. In conclusion, we demonstrate that SFI protects against sepsis-induced myocardial injury in mice through the suppression of myocardial apoptosis. It upregulates the protein expression of Bcl-2 and downregulates the protein expression of Bid, t-Bid and caspase-9, and alleviates sepsis-induced mitochondrial damage. Image 1 [ABSTRACT FROM AUTHOR]
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- 2020
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7. Inferior vestibular neuritis in a fighter pilot: A case report.
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Xie Su Jiang, Jia Hong Bo, Xu Po, and Zheng Ying Juan
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VESTIBULAR apparatus diseases , *NEURITIS , *AIR pilots , *VERTIGO , *VESTIBULAR function tests , *DIAGNOSIS - Published
- 2013
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8. Genome-wide identification and expression analysis of terpene synthase gene family in Aquilaria sinensis.
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Li, Rong-Shuang, Zhu, Jia-Hong, Guo, Dong, Li, Hui-Liang, Wang, Ying, Ding, Xu-Po, Mei, Wen-Li, Chen, Zhi-Bao, Dai, Hao-Fu, and Peng, Shi-Qing
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GENE families , *TERPENES , *JASMONIC acid , *TRANSCRIPTION factors , *GENE expression , *BRASSINOSTEROIDS - Abstract
Agarwood is the resinous portion of Aquilaria trees, and has been widely used as medicine and incense. Sesquiterpenes are the main chemical characteristic constituents of agarwood. Terpene synthase (TPS) is a critical enzyme responsible for biosynthesis of sesquiterpene compounds. However, limited information is available on genome-wide identification and characterization of the TPS family in Aquilaria trees. In this study, TPS gene family was identified and characterized in A quilaria sinensis by bioinformatics methods. The expression of those genes was analyzed by RNA-seq and quantitative real-time PCR. Transcription factors regulating TPS gene expression were identified by yeast one-hybrid and dual-luciferase assay. In total, 26 AsTPS genes (AsTPS1–AsTPS26) were identified, which were classified into five subgroups. Many putative cis-elements putatively involved in stresses and phytohormones (especially jasmonic acid) were identified in the promoter regions of AsTPSs , suggesting that AsTPSs genes may be regulated by stresses and jasmonic acid. Expression analysis revealed seven TPS genes encoding sesquiterpene synthetases were induced by wounding and methyl jasmonic acid (MeJA), which may be related to sesquiterpene biosynthesis. By yeast one-hybrid screening, a ERF transcription factor AsERF1 was identified to interact with the AsTPS1 promoter. Subcellular localization analysis indicated AsERF1 was a nucleus-localized protein. Transient transfection of AsERF1 in leaves of Nicotiana benthamiana significantly enhanced the promoter activation of AsTPS1 , suggesting AsERF1 may participate in sesquiterpene biosynthesis by regulating AsTPS1 expression. These data generated in this study provide a foundation for future studies on functional roles and regulation mechanisms of AsTPS in sesquiterpene biosynthesis and agarwood formation. • 26 terpene synthases (TPS) genes were identified in Aquilaria sinensis. • Seven TPS genes were induced by wounding and methyl jasmonic acid, which may be related to sesquiterpene biosynthesis. • A ERF transcription factor AsERF1 was identified to interact with the AsTPS1 promoter. • AsERF1 could significantly activate the AsTPS1 promoter in Nicotiana benthamiana. [ABSTRACT FROM AUTHOR]
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- 2021
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9. Model Predictive Control Method of Torque Ripple Reduction for BLDC Motor.
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Xia, Kun, Ye, Yanhong, Ni, Jiawen, Wang, Yiming, and Xu, Po
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TORQUE control , *PREDICTION models , *ELECTRIC potential , *BRUSHLESS electric motors , *COMPUTER software , *BRAIN-computer interfaces , *AUTOMOBILE driving simulators - Abstract
The commutation torque ripple of a brushless dc motor (BLDCM) in a six-step driving mode generates vibration noise. To minimize the commutation torque ripple of the BLDCM, this article analyzes the cause of torque ripple and establishes the model of torque ripple suppression by using the phase current predictive method based on the trapezoidal back electromotive force (EMF). In addition, based on the prediction model of the non-commutation phase current, the pulsewidth modulation model predictive control (PWM-MPC) algorithm is proposed. By changing the duty cycle with prior evaluation, the predictive control avoids commutation current hopping, thereby reducing torque ripple during commutation. This control approach is more accessible to be implemented, because it does not require changing the topology of the motor driving circuit. Simulation models of the proposed control scheme constructed in the MATLAB/Simulink environment are given, compared with the conventional square-wave driving method. Moreover, experiments are performed to verify the feasibility. The output torque during experiments is transmitted to the computer software through the torque transducer. Compared with the traditional driving methods, the simulation and experimental results show that the proposed novel algorithm in this article could suppress the torque ripple efficiently. [ABSTRACT FROM AUTHOR]
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- 2020
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10. Honokiol Attenuates the Memory Impairments, Oxidative Stress, Neuroinflammation, and GSK-3β Activation in Vascular Dementia Rats.
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Guo, Si, Xu, Jing-Jing, Wei, Na, Han, Jun-Ya, Xue, Rui, Xu, Po-Shi, Gao, Chuan-Yu, and Zhu, Ling-Qiang
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VASCULAR dementia , *OXIDATIVE stress , *MAZE tests , *MEMORY , *ALZHEIMER'S disease , *RATS , *DENDRITIC spines - Abstract
Vascular dementia (VaD) is caused by chronic decreases in brain blood flow and accounts for 15-20% of dementia cases worldwide. In contrast to Alzheimer's disease (AD), no effective drug treatments are currently available for VaD. Previous studies have suggested that oxidative stress and neuroinflammation in the brain play important roles in the pathogenesis of VaD. Honokiol (HKL) is a well-known bioactive and nutraceutical compound that can act as an antioxidant and anti-inflammatory molecule. HKL can protect against memory impairments in AD mouse models. In this study, we explored whether the application of HKL was also protective against the insult of chronic cerebral hypoperfusion (CCH) in rats. We found that HKL supplementation prevented the memory impairments in the inhibitory avoidance step-down and Morris water maze tasks in CCH rats. HKL also suppressed the levels of oxidative stress and inflammation in CCH rats. Moreover, HKL prevented dendritic spines abnormalities in CCH rats. We also found that HKL inhibited the activity of GSK-3β, which may be critical for the neuroprotective activity of HKL. Thus, our study demonstrated the protective role of HKL in VaD. [ABSTRACT FROM AUTHOR]
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- 2019
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11. High lncRNA HULC expression is associated with poor prognosis and promotes tumor progression by regulating epithelial-mesenchymal transition in prostate cancer.
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Pengyi Zheng, Huibing Li, Po Xu, Xiaohui Wang, Zhenguo Shi, Qingjiang Han, Zhijun Li, Zheng, Pengyi, Li, Huibing, Xu, Po, Wang, Xiaohui, Shi, Zhenguo, Han, Qingjiang, and Li, Zhijun
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NON-coding RNA , *GENE expression , *CANCER invasiveness , *PROSTATE cancer prognosis , *POLYMERASE chain reaction - Abstract
Introduction: Recently, increasing evidence has shown that long non-coding RNAs (lncRNAs) play critical roles in tumor progression and development. However, the expression pattern and biological function of lncRNA HULC (highly upregulated in liver cancer) in prostate cancer (PCa) remain largely unclear.Material and Methods: The expression of lncRNA HULC in 53 paired PCa tissues and cell lines was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The χ2 test was used to explore the association of lncRNA HULC expression with clinicopathologic features. Kaplan-Meier analysis was used to detect the association between HULC expression and overall survival of PCa patients. Furthermore, the function of HULC in cell growth and metastasis was detected in PCa cells.Results: Our data showed that HULC expression was upregulated in PCa tissues and cell lines compared to adjacent non-tumor tissues and the normal prostate cell line RWPE-1 (p < 0.05). High HULC expression was positively associated with advanced clinicopathologic features and poor overall survival (OS) for PCa patients (p < 0.05). HULC inhibition suppressed PCa cell growth and metastasis both in vitro and in vivo (p < 0.05). Furthermore, HULC knockdown reduced N-cadherin and vimentin expression and increased E-cadherin expression in PCa cells (p < 0.05).Conclusions: Our data suggested that lncRNA HULC might play oncogenic roles in PCa progression, which provided a novel therapeutic strategy for PCa patients. [ABSTRACT FROM AUTHOR]- Published
- 2018
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12. MicroRNA-183 functions as the tumor suppressor via inhibiting cellular invasion and metastasis by targeting MMP-9 in cervical cancer.
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Fan, Dongmei, Wang, Ying, Qi, Pengwei, Chen, Yawei, Xu, Po, Yang, Xianan, Jin, Ximeng, and Tian, Xiaoyu
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CERVICAL cancer , *CANCER invasiveness , *MICRORNA , *TUMOR suppressor genes , *TARGETED drug delivery , *MATRIX metalloproteinases , *CANCER cells , *GENETICS - Abstract
Objective MicroRNAs have been reported to play an important role in the invasion and metastasis of cervical cancer. miR-183 was found to inhibit or promote the invasion and metastasis of multiple solid tumors. However, the roles of miR-183 in cervical cancer are unclear. Methods In this study, miR-183 expression levels were measured in 53 cervical cancer and 13 normal cervical tissues by qRT-PCR. The effects of forced expression of miR-183 on cervical cancer cells invasion and metastasis were investigated using Transwell uncoated or coated with growth factor-reduced Matrigel for migration or invasion assays, respectively. Results We found that miR-183 expression levels were significantly down-regulated in cervical cancer tissues compared with normal tissues (0.15 ± 0.011 to 0.86 ± 0.049). Ectopic expression of miR-183 resulted in the suppression of invasion and migration of cervical cancer cell lines, siha and Hela cells ( p < 0.0001). Bioinformatics analysis revealed that MMP-9 was the potential target of miR-183 and it was found that MMP-9 was remarkably up-regulated in cervical cancer. Furthermore, a dual-luciferase reporter assay showed that MMP-9 as a target of miR-183 ( p < 0.0001). The invasion and metastasis ability of siha and Hela was suppressed when MMP-9 was down-regulated in vitro ( p < 0.0001). Conclusions In conclusion, our study revealed that miR-183 might be a tumor suppressor via inhibiting the invasion and metastasis of cervical cancer cells through targeting MMP-9, indicating that miR-183 may be a novel potential therapeutic target for cervical cancer. [ABSTRACT FROM AUTHOR]
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- 2016
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13. Multidrug-Resistance Related Long Non-Coding RNA Expression Profile Analysis of Gastric Cancer.
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Wang, Ying, Wu, Kaichun, Yang, Zhiping, Zhao, Qingchuan, Fan, Dongmei, Xu, Po, Nie, Yongzhan, and Fan, Daiming
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STOMACH cancer , *MULTIDRUG resistance , *NON-coding RNA , *DOWNREGULATION , *MICROARRAY technology , *BIOINFORMATICS , *GENETICS - Abstract
The effect of chemotherapy of gastric cancer (GC) remains very poor because of multidrug resistance (MDR). However, the mechanisms underlying MDR of GC remains far from fully understood. The aim of this study is to illustrate the potential mechanisms of the MDR of GC at mainly the long non-coding RNA (lncRNA) level. In this study, GC cell line, SGC7901, and two MDR sublines, SGC7901/VCR and SGC7901/ADR were subjected to an lncRNA microarray analysis. Bioinformatics and verification experiments were performed to investigate the potential lncRNAs involved in the development of MDR. Pathway analysis indicated that 15 pathways corresponded to down-regulated transcripts and that 20 pathways corresponded to up-regulated transcripts (p-value cut-off is 0.05). GO analysis showed that the highest enriched GOs targeted by up-regulated transcripts were “system development” and the highest esenriched GOs targeted by the down-regulated transcripts were “sterol biosynthetic process”. Our study is the first to interrogate differentially expressed lncRNAs in human GC cell line and MDR sublines and indicates that lncRNAs are worthwhile for further study to be the novel candidate biomarkers for the clinical diagnosis of MDR and potential targets for further therapy. [ABSTRACT FROM AUTHOR]
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- 2015
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14. New tricyclic prezizaane sesquiterpenoids from agarwood.
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Yang, Yi-Ling, Li, Wei, Wang, Hao, Yang, Li, Yuan, Jing-Zhe, Cai, Cai-Hong, Chen, Hui-Qin, Dong, Wen-Hua, Ding, Xu-Po, Jiang, Bei, Mándi, Attila, Kurtán, Tibor, Mei, Wen-Li, and Dai, Hao-Fu
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ANALYTICAL chemistry techniques , *MOLECULAR structure , *NUCLEAR magnetic resonance spectroscopy , *ORGANIC compounds , *RESEARCH funding , *TERPENES , *PLANT extracts - Abstract
Ten new tricyclic prezizaane types sesquiterpenoids (1 − 10) were isolated from ethyl ether extract of agarwood originated from Aquilaria sp. Their structures were unambiguously elucidated on the basis of 1D and 2D NMR spectra as well as by HRESIMS data. The absolute configuration of the new prezizaenes 1 , 2 and 4 was determined by single-crystal X-ray diffraction, while TDDFT-ECD method was applied for 6. Compounds 4 and 5 displayed significant inhibitory activities toward α -glucosidase with IC 50 values of 0.22 and 1.99 mM, respectively. Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2019
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