VALVE MOTION CHARACTERISTICS AND APPLICATION ON ENGINE BASED ON A NEW VARIABLE VALVE ACTUATION SYSTEM

You Zhou,Weihong Zhou,Fangxi Xie,Yu Liu,Xiaoping Li,Xun Gong 한국자동차공학회 2023 International journal of automotive technology Vol.24 No.1

A new mechanical-hydraulic variable valve actuation (VVA) system was developed and a thin-wall orifice velocity control system were analyzed. Meanwhile, influence of speed, needle valve overflow area, oil temperature and oil supply pressure on valve motion characteristics were explored, as well as the VVA system have been applied on a single-cylinder engine preliminary. By the VVA system, valve lifts can be adjusted from maximum of 8.7 mm to fully closing. Valve seating velocity decreased with orifice diameter reducing. Seating velocity can be maintained below 0.5 m/s with 0.8 mm diameter of thin-wall orifice and 3 mm check valve moving distance. Besides that, velocity control system also can help improve the coefficient of cyclic variation of maximum valve lift. Except for the needle valve closing state, valve lift decreased with oil temperature increasing and operating speed reducing under the same needle valve state. Oil supply pressure hardly had no influence on valve lifts, but delayed valve opening timing with pressure decreasing. Thin-wall orifice seating velocity control system was not sensitive to variable oil temperature and supply pressure. Compared with conventional engine, adjusting intake valve by VVA system under un-throttle internal EGR strategy, can improve BSFC and NOX emissions significantly about 13.8 % and 19.8 % on 6 bar IMEP.

MicroRNA-766-3p Inhibits Tumour Progression by Targeting Wnt3a in Hepatocellular Carcinoma

You, Yu,Que, Keting,Zhou, Yun,Zhang, Zhen,Zhao, Xiaoping,Gong, Jianpin,Liu, Zuojin Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.9

Recent studies have indicated that microRNAs (miRNAs) play an important role in hepatocellular carcinoma (HCC) progression. In this study, we showed that miR-766-3p was decreased in approximately 72% of HCC tissues and cell lines, and its low expression level was significantly correlated with tumour size, TNM stage, metastasis, and poor prognosis in HCC. Ectopic miR-766-3p expression inhibited HCC cell proliferation, colony formation, migration and invasion. In addition, we showed that miR-766-3p repressed Wnt3a expression. A luciferase reporter assay revealed that Wnt3a was a direct target of miR-766-3p, and an inverse correlation between miR-766-3p and Wnt3a expression was observed. Moreover, Wnt3a up-regulation reversed the effects of miR766-3p on HCC progression. In addition, our study showed that miR-766-3p up-regulation decreased the nuclear ${\beta}-catenin$ level and expression of Wnt targets (TCF1 and Survivin) and reduced the level of MAP protein regulator of cytokinesis 1 (PRC1). However, these effects of miR-766-3p were reversed by Wnt3a up-regulation. In addition, PRC1 upregulation increased the nuclear ${\beta}-catenin$ level and protein expression of TCF1 and Survivin. iCRT3, which disrupts the ${\beta}-catenin-TCF4$ interaction, repressed the TCF1, Survivin and PRC1 protein levels. Taken together, our results suggest that miR-766-3p down-regulation promotes HCC cell progression, probably by targeting the Wnt3a/PRC1 pathway, and miR-766-3p may serve as a potential therapeutic target in HCC.

Changes in element accumulation, phenolic metabolism, and antioxidative enzyme activities in the red-skin roots of Panax ginseng

Zhou, Ying,Yang, Zhenming,Gao, Lingling,Liu, Wen,Liu, Rongkun,Zhao, Junting,You, Jiangfeng The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.3

Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease's origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbate-glutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of $H_2O_2$ and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of $\text\tiny L$-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbate-glutathione cycles, are activated to protect against phenolic compound oxidation.

Changes in element accumulation, phenolic metabolism, and antioxidative enzyme activities in the red-skin roots of Panax ginseng

Ying Zhou,Zhenming Yang,Lingling Gao,Wen Liu,Rongkun Liu,Junting Zhao,Jiangfeng You 고려인삼학회 2017 Journal of Ginseng Research Vol.41 No.3

Background: Red-skin root disease has seriously decreased the quality and production of Panax ginseng (ginseng). Methods: To explore the disease’s origin, comparative analysis was performed in different parts of the plant, particularly the epidermis, cortex, and/or fibrous roots of 5-yr-old healthy and diseased red-skin ginseng. The inorganic element composition, phenolic compound concentration, reactive oxidation system, antioxidant concentrations such as ascorbate and glutathione, activities of enzymes related to phenolic metabolism and oxidation, and antioxidative system particularly the ascorbateeglutathione cycle were examined using conventional methods. Results: Aluminum (Al), iron (Fe), magnesium, and phosphorus were increased, whereas manganese was unchanged and calcium was decreased in the epidermis and fibrous root of red-skin ginseng, which also contained higher levels of phenolic compounds, higher activities of the phenolic compound-synthesizing enzyme phenylalanine ammonia-lyase and the phenolic compound oxidation-related enzymes guaiacol peroxidase and polyphenoloxidase. As the substrate of guaiacol peroxidase, higher levels of H2O2 and correspondingly higher activities of superoxide dismutase and catalase were found in red-skin ginseng. Increased levels of ascorbate and glutathione; increased activities of L-galactose 1-dehydrogenase, ascorbate peroxidase, ascorbic acid oxidase, and glutathione reductase; and lower activities of dehydroascorbate reductase, monodehydroascorbate reductase, and glutathione peroxidase were found in red-skin ginseng. Glutathione-S-transferase activity remained constant. Conclusion: Hence, higher element accumulation, particularly Al and Fe, activated multiple enzymes related to accumulation of phenolic compounds and their oxidation. This might contribute to red-skin symptoms in ginseng. It is proposed that antioxidant and antioxidative enzymes, especially those involved in ascorbateeglutathione cycles, are activated to protect against phenolic compound oxidation.

MicroRNA-766-3p Inhibits Tumour Progression by Targeting Wnt3a in Hepatocellular Carcinoma

Yu You,Keting Que,Yun Zhou,Zhen Zhang,Xiaoping Zhao,Jianpin Gong,Zuojin Liu 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.9

Recent studies have indicated that microRNAs (miRNAs) play an important role in hepatocellular carcinoma (HCC) progression. In this study, we showed that miR-766-3p was decreased in approximately 72% of HCC tissues and cell lines, and its low expression level was significantly correlated with tumour size, TNM stage, metastasis, and poor prognosis in HCC. Ectopic miR-766-3p expression inhibited HCC cell proliferation, colony formation, migration and invasion. In addition, we showed that miR-766-3p repressed Wnt3a expression. A luciferase reporter assay revealed that Wnt3a was a direct target of miR-766-3p, and an inverse correlation between miR-766-3p and Wnt3a expression was observed. Moreover, Wnt3a up-regulation reversed the effects of miR-766-3p on HCC progression. In addition, our study showed that miR-766-3p up-regulation decreased the nuclear β-catenin level and expression of Wnt targets (TCF1 and Survivin) and reduced the level of MAP protein regulator of cytokinesis 1 (PRC1). However, these effects of miR-766-3p were reversed by Wnt3a up-regulation. In addition, PRC1 upregulation increased the nuclear β-catenin level and protein expression of TCF1 and Survivin. iCRT3, which disrupts the β-catenin-TCF4 interaction, repressed the TCF1, Survivin and PRC1 protein levels. Taken together, our results suggest that miR-766-3p down-regulation promotes HCC cell progression, probably by targeting the Wnt3a/PRC1 pathway, and miR-766-3p may serve as a potential therapeutic target in HCC.

Sanshool from Zanthoxylum L. Induces Apoptosis in Human Hepatocarcinoma HepG2 Cells

Yuming You,Min Zhou,Hongjia Lu,Gasper Gerald Shirima,Yajiao Cheng,Xiong Liu 한국식품과학회 2015 Food Science and Biotechnology Vol.24 No.6

Anti-proliferation and apoptosis induction activities of sanshool isolated from Zanthoxylum bungeanum (Rutaceae) in HepG2 cells were investigated. Cell proliferation was analyzed using MTT assays. Apoptotic bodies were observed under scanning electron microscopy. Nucleus staining using dichlorofluorescin diacetate (DAPI) was performed and the mitochondrial membrane potential (ΔΨm) using rhodamine-123 was observed under laser confocal microscopy. Sanshool inhibited cell proliferation in both a dose and time-dependent manner. The anti-proliferation activity was stimulated with apoptosis induction based on an increase in the sub-G1 cell population, DNA fragmentation, and typical apoptotic morphological changes. Sanshool also disrupted ΔΨm and up-regulated mRNA and protein expressions of p53 and caspase-3. Sanshool induced apoptosis via a mitochondrion-dependent pathway. Thus, sanshool is a potential anticancer medicine.

The Influence of Circadian Gene Per2 on Cell Damaged by Ultraviolet C

( Yan You Liu ),( Yu Hui Wang ),( Zhou Jiang ),( Jing Xiao ),( Zheng Rong Wang ) 한국응용약물학회 2011 Biomolecules & Therapeutics(구 응용약물학회지) Vol.19 No.3

It has been shown that circadian genes not only play an important role on circadian rhythms, but also participate in other physiological and pathological activities, such as drug dependence, cancer development and radiation injury. The Per2, an indispensable component of the circadian clock, not only modulates circadian oscillations, but also regulates organic function. In the present study, we applied mPER2-upregulated NIH3T3 cells to reveal the relationship of mPer2 and the cells damaged by ultraviolet C (UVC). NIH3T3 cells at the peak of the expression of mPer2 induced by phorbol 12-myristate 13-acetate (PMA) demonstrated little damage by UVC evaluated by MTT assay, cell growth curves and cell colony-forming assay, compared with that at the nadir of the expression of mPer2. Overexpression of mPER2, accompanied p53 upregulated, also demonstrated protective effect on NIH3T3 cells damaged by UVC. These results suggest that mPer2 plays a protective effect on cells damaged by UVC, whose mechanism may be involved in upregulated p53.

Comparison study of the effect of bridge-tunnel transition on train aerodynamic performance with or without crosswind

Lei Zhou,Tanghong Liu,Zhengwei Chen,Wenhui Li,Zijian Guo,Xuhui He,You-Wu Wang 한국풍공학회 2021 Wind and Structures, An International Journal (WAS Vol.32 No.6

This paper studied the case of high-speed train running from flat ground to bridges and into/out of tunnels, with or without crosswind based on the Computational Fluid Dynamics (CFD) method. First, the flow structure was analyzed to explain the influence mechanisms of different infrastructures on the aerodynamic characteristics of the train. Then, the evolution of aerodynamic forces of the train during the entire process was analyzed and compared. Additionally, the pressure variation on the train body and the tunnel wall was examined in detail. The results showed that the pressure coefficient and the flow structure on both sides of the high-speed train were symmetrical for no crosswind case. By contrast, under crosswind, there was a tremendous and immediate change in the pressure mapping and flow structure when the train passing through the bridge-tunnel section. The influence of the ground-bridge transition on the aerodynamic forces was much smaller than that of the bridge-tunnel section. Moreover, the variation of aerodynamic load during the process of entering and exiting the bridge-tunnel sections was both significant. In addition, in the case without crosswind, the change in the pressure change in the tunnel conformed to the law of pressure wave propagation, while under crosswind, the variation in pressure was comprehensively affected by both the train and crosswind in the tunnel.

Null Glutathione S-transferase T1 and M1 Genotypes and Oral Cancer Susceptibility in China and India - a Meta-analysis

Peng, Jie,Liu, Hong-Zhou,Zhu, You-Jia Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.1

Objective: Genetic variation is considered to strongly impact on detoxification of carcinogens and therefore is related to cancer risk. However, findings for the null genotypes of GSTT1 and GSTM1 have not always been consistent. Therefore the present meta-analysis was conducted. Methods: We accessed the reported study at different research areas and used various databases, including PubMed and Wanfang Med Onlion from 1990 to May 1st 2013. We calculated the odds ratio (OR), 95% confidence interval (CI) and P value for oral cancer by using Review Manager 5.1 and STATE 12. Results: We found that there was no increased oral cancer risk among subjects carrying GSTM1 and GSTT1 null genotype (OR=1.35, 95%CI=0.68-2.68, P=0.39) and (OR=1.41, 95%CI=0.72-2.77, P=0.31) in the Chinese population. In contrast, in studies in India a significant correlation between GSTM1 null genotype and oral cancer was observed (OR=1.59, 95%CI=1.20-2.11, P=0.001), but not in GSTT1 (OR=1.21, 95% CI=0.84-1.74, P=0.31). Conclusion: We discovered that GSTM1 deletion polymorphism had a significant effect on the susceptibility of oral cancer in the Indian population.

Application of Intraoperative Ultrasonography for Guiding Microneurosurgical Resection of Small Subcortical Lesions

Jia Wang,Yun You Duan,Xi Liu,Yu Wang,Guo Dong Gao,Huai Zhou Qin,Liang Wang 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.5

Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions. Objective: We wanted to evaluate the clinical value of intraoperative ultrasonography for real-time guidance when performing microneurosurgical resection of small subcortical lesions. Materials and Methods: Fifty-two patients with small subcortical lesions were involved in this study. The pathological diagnoses were cavernous hemangioma in 25 cases, cerebral glioma in eight cases, abscess in eight cases, small inflammatory lesion in five cases, brain parasite infection in four cases and the presence of an intracranial foreign body in two cases. An ultrasonic probe was sterilized and lightly placed on the surface of the brain during the operation. The location, extent, characteristics and adjacent tissue of the lesion were observed by high frequency ultrasonography during the operation. Results: All the lesions were located in the cortex and their mean size was 1.3 ± 0.2 cm. Intraoperative ultrasonography accurately located all the small subcortical lesions, and so the neurosurgeon could provide appropriate treatment. Different lesion pathologies presented with different ultrasonic appearances. Cavernous hemangioma exhibited irregular shapes with distinct margins and it was mildly hyperechoic or hyperechoic. The majority of the cerebral gliomas displayed irregular shapes with indistinct margins, and they often showed cystic and solid mixed echoes. Postoperative imaging identified that the lesions had completely disappeared, and the original symptoms of all the patients were significantly alleviated. Conclusion: Intraoperative ultrasonography can help accurately locate small subcortical lesions and it is helpful for selecting the proper approach and guiding thorough resection of these lesions.