Biomimetic Total Synthesis of Paeoveitol

Zhang, Yuhan,Guo, Yonghong,Li, Zhongle,Xie, Zhixiang American Chemical Society 2016 ORGANIC LETTERS Vol.18 No.18

<P>A highly stereocontrolled synthesis of paeoveitol has been developed in 26% yield, in 7 steps from commercially available materials. The synthetic strategy was inspired primarily by the biogenetic hypothesis and was enabled by hetero-Diels–Alder cycloaddition to construct the target molecular framework.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2016/orlef7.2016.18.issue-18/acs.orglett.6b02228/production/images/medium/ol-2016-02228p_0009.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol6b02228'>ACS Electronic Supporting Info</A></P>

Carbon dispersed iron-manganese catalyst for light olefin synthesis from CO hydrogenation

Jianli Zhang,Kegong Fang,Kan Zhang,Wenhuai Li,Yuhan Sun 한국화학공학회 2009 Korean Journal of Chemical Engineering Vol.26 No.3

High performance iron-manganese catalysts dispersed with carbon to produce light olefins from CO hydrogenation were prepared by sol-gel method using citric acid as precursor. The effects of carbon content on the bulk structure, the water gas shift reaction, the chain propagation ability and the activity and selectivity of the catalysts were investigated. The results showed that the catalysts were gradually reduced during the decomposition of the precursor when calcined under pure N2. The formation of iron-manganese mixed crystallites was favored and stabilized because of the enhanced interaction of iron and manganese with increasing carbon content. During the subsequent CO hydrogenation reaction, all the catalysts showed high activity and olefin selectivity. With increasing carbon content, the water gas shift (WGS) reaction was restrained and the chain propagation ability was inhibited. Catalysts with higher carbon content showed much lighter hydrocarbon products; however, the selectivity of CH4 was almost unchanged.

Protective effect of hepatocyte-enriched lncRNA-Mir122hg by promoting hepatocyte proliferation in acute liver injury

Yu Zhenjun,Li Yuhan,Shao Shuai,Guo Beichen,Zhang Mengxia,Zheng Lina,Zhang Kun,Zhou Feng,Zhang Li,Chen Chiyi,Jiang Wentao,Hong Wei,Han Tao 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Some long noncoding RNAs (lncRNAs), which harbor microRNAs in their gene sequence and are also known as microRNA host gene derived lncRNAs (lnc-MIRHGs), play a dominant role alongside miRNAs, or both perform biological functions synergistically or independently. However, only a small number of lnc-MIRHGs have been identified. Here, multiple liver injury datasets were analyzed to screen and identify the target lncRNA Mir122hg. Mir122hg was mainly enriched in liver tissues with human-mouse homology. In both CCl4-induced acute liver injury and Dgal/LPS-induced fulminant liver failure in mice, Mir122hg was sharply downregulated at the early stage, while a subsequent significant increase was only found in the CCl4 group with liver recovery. Overexpression and silencing assays confirmed that Mir122hg played a protective role in acute injury by promoting hepatocyte proliferation in vivo and in vitro. Consistent with the results of gene enrichment analysis, Mir122hg binding to C/EBPα affected its transcriptional repression, promoted gene transcription of downstream chemokines, Cxcl2, Cxcl3, and Cxcl5, and exerted pro-proliferative effects on hepatocytes through activation of the AKT/GSK-3β/p27 signaling pathway by CXC/CXCR2 complexes. This study identifies a novel lncRNA with protective effects in acute liver injury and demonstrates that the binding of Mir122hg-C/EBPα promotes hepatocyte proliferation via upregulation of CXC chemokine and activation of AKT signaling.

HIST1H2BN induced cell proliferation and EMT phenotype in prostate cancer via NF-κB signal pathway

Zhang Juan,Chang Yuhan,Xia Haiyan,Xu Luwei,Wei Xiaowei 한국유전학회 2021 Genes & Genomics Vol.43 No.11

Background The potential role of HIST1H2BN in prostate cancer remains unclear. Objective To evaluate the carcinogenic role of HIST1H2BN in prostate cancer. Methods The expression of HIST1H2BN in prostate cancer was analyzed using TCGA database and clinical samples. The roles and mechanisms of HIST1H2BN were investigated in DU145 and PC3 cells. Results HIST1H2BN was signifcantly upregulated in prostate cancer. HIST1H2BN knockdown inhibited cell proliferation, migration and EMT phenotype in prostate cancer cells. Downregulating HIST1H2BN diminished the expression and binding activity of NF-κB p65, then infuenced the expression of MMP2 and MMP9. Conclusion This is the frst study to elaborate a HIST1H2BN-NF-κB-EMT regulatory axis in oncogenesis, indicating that HIST1H2BN might be potential therapeutic target for prostate cancer.

Robust IFNTSM–ESO Control Design for Aircraft Subject to Parameter Uncertainties

Jing Zhang,Jianing Yan,Lingyu Yang,Yuhan Mou 한국항공우주학회 2020 International Journal of Aeronautical and Space Sc Vol.21 No.1

A comprehensive strategy that combines improved fast nonsingular terminal sliding mode (IFNTSM) control and an extended state observer (ESO) is developed to solve the problems of uncertainty in the aeronautical field. First, the IFNTSM control method is proposed to solve the singularity problem and guarantee a faster finite-time convergence speed. Second, an ESO is introduced to estimate the parameter uncertainties, and then a control scheme that combines IFNTSM and ESO is developed to overcome the drawback of large switching gains in a sliding mode controller and alleviate the chattering problem. The stability of the composite system is analyzed via the Lyapunov stability theorem. Finally, the simulation demonstrates that the composite controller accelerates the convergence speed and offers excellent robustness for complex parameter uncertainties.

Improved Genetic Algorithm based 3-D deployment of UAVs

Xiting Wen,Yuhan Ruan,Yongzhao Li,Hongxing Xia,Rui Zhang,Chao Wang,Wei Liu,Xiaoyu Jiang 한국통신학회 2022 Journal of communications and networks Vol.24 No.2

Unmanned aerial vehicles (UAVs) are widely usedas aerial base stations (BSs) to provide flexible connectivity andcoverage for ground users in various scenarios such as disasterrelief, traffic offloading, and so on. Especially, UAV deployment isan important issue that directly affects the coverage performanceof the UAV network. In this paper, we propose a novel heuristic algorithmbased three-dimensional (3-D) UAV deployment schemewhile guaranteeing the connectivity of the UAV network in bothstatic and dynamic user scenarios. For the static user scenario, weaim to deploy the minimum number of UAVs to provide coveragefor the users from the perspective of deployment cost. To reducethe deployment complexity, we decouple the 3-D UAV deploymentproblem from the vertical and horizontal dimensions. Specifically,we firstly determine the optimal vertical height of UAVs based onthe air-to-ground (A2G) model. Then, to alleviate the prematureconvergence of standard genetic algorithm (SGA), we designan improved genetic algorithm (IGA) to obtain the optimalhorizontal locations of UAVs. On this basis, when the users moveor increase, i.e., the dynamic user scenario, the already deployedUAVs cannot provide effective coverage. For this scenario, wepropose a UAV redeployment scheme to maximize the numberof covered users without increasing the number of UAVs. Tofurther reduce the cost of redeployment, we firstly modify theproposed IGA to obtain a feasible set of two-dimensional (2-D)redeployed locations of the UAVs. Then, we design a backtrackingalgorithm (BA) based UAV movement strategy to minimize thetotal flying distance of the UAVs. The simulation results showthat the effectiveness and convergence of our proposed schemes.

The involvement of Parkin-dependent mitophagy in the anti-cancer activity of Ginsenoside

Xin Sun,Yeting Hong,Yuhan Shu,Caixia Wu,Guiqin Ye,Hanxiao Chen,Hongying Zhou,Ruilan Gao,Jianbin Zhang 고려인삼학회 2022 Journal of Ginseng Research Vol.46 No.2

Colon cancer, the third most frequent occurred cancer, has high mortality and extremely poor prognosis. Ginsenoside, the active components of traditional Chinese herbal medicine Panax ginseng, exerts antitumor effect in various cancers, including colon cancer. However, the detailed molecular mechanism of Ginsenoside in the tumor suppression have not been fully elucidated. Here, we chose the representative ginsenoside Rg3 and reported for the first time that Rg3 induces mitophagy in human colon cancer cells, which is responsible for its anticancer effect. Rg3 treatment leads to mitochondria damage and the formation of mitophagosome; when autophagy is inhibited, the clearance of damaged mitochondria can be reversed. Next, our results showed that Rg3 treatment activates the PINK1-Parkin signaling pathway and recruits Parkin and ubiquitin proteins to mitochondria to induce mitophagy. GO analysis of Parkin targets showed that Parkin interacts with a large number of mitochondrial proteins and regulates the molecular function of mitochondria. The cellular energy metabolism enzyme GAPDH is validated as a novel substrate of Parkin, which is ubiquitinated by Parkin. Moreover, GAPDH participates in the Rg3-induced mitophagy and regulates the translocation of Parkin to mitochondria. Functionally, Rg3 exerts the inhibitory effect through regulating the nonglycolytic activity of GAPDH, which could be associated with the cellular oxidative stress. Thus, our results revealed GAPDH ubiquitination by Parkin as a crucial mechanism for mitophagy induction that contributes to the tumor-suppressive function of ginsenoside, which could be a novel treatment strategy for colon cancer.

Kinetics studies of dimethyl carbonate synthesis from urea and methanol over ZnO catalyst

Wei Wei,Junliang Zhang,Feng Wang,Fukui Xiao,Yuhan Sun 한국화학공학회 2010 Korean Journal of Chemical Engineering Vol.27 No.6

A kinetic experiment of dimethyl carbonate (DMC) synthesis by urea methanol over ZnO catalyst was carried out in an isothermal fixed-bed reactor. A kinetic model based on the mole fraction was proposed and the kinetic parameters were estimated from the experimental results. The model predictions were compared with the experimental data and fair agreements were found. The effects of the reaction temperature (443-473 K), space time (0-4.7 h mol−1kgcat) and urea mass percent (5-9%) in feed on DMC mole fraction were investigated. It was found that the reactions are mainly influenced by the reaction temperature and space time rather than urea mass percent in feed. The experimental and simulated results indicated that the reaction from MC to DMC was the rate-controlling step in the DMC synthesis process from urea and methanol. It is important to remove the DMC and byproduct ammonia to achieve a high selectivity of DMC. This implies that reactive distillation might be used in the DMC synthesis on an industrial scale to achieve a higher selectivity of DMC.

Risk Prediction Model for Radiation-induced Dermatitis in Patients with Cervical Carcinoma Undergoing Chemoradiotherapy

Hong Yang,Yaru Zhang,Fanxiu Heng,Wen Li,Yumei Feng,Jie Tao,Lijun Wang,Zhili Zhang,Xiaofan Li,Yuhan Lu 한국간호과학회 2024 Asian Nursing Research Vol.18 No.2

PurposeRadiation-induced dermatitis (RD) is a common side-effect of therapeutic ionizing radiation that can severely affect patient quality of life. This study aimed to develop a risk prediction model for the occurrence of RD in patients with cervical carcinoma undergoing chemoradiotherapy using electronic medical records (EMRs). MethodsUsing EMRs, the clinical data of patients who underwent simultaneous radiotherapy and chemotherapy at a tertiary cancer hospital between 2017 and 2022 were retrospectively collected, and the patients were divided into two groups: a training group and a validation group. A predictive model was constructed to predict the development of RD in patients who underwent concurrent radiotherapy and chemotherapy for cervical cancer. Finally, the model's efficacy was validated using a receiver operating characteristic curve. ResultsThe incidence of radiation dermatitis was 89.5% (560/626) in the entire cohort, 88.6% (388/438) in the training group, and 91.5% (172/188) in the experimental group. The nomogram was established based on the following factors: age, the days between the beginning and conclusion of radiotherapy, the serum albumin after chemoradiotherapy, the use of single or multiple drugs for concurrent chemotherapy, and the total dose of afterloading radiotherapy. Internal and external verification indicated that the model had good discriminatory ability. Overall, the model achieved an area under the receiver operating characteristic curve of .66. ConclusionsThe risk of RD in patients with cervical carcinoma undergoing chemoradiotherapy is high. A risk prediction model can be developed for RD in cervical carcinoma patients undergoing chemoradiotherapy, based on over 5 years of EMR data from a tertiary cancer hospital.

Fixed switching frequency strategy for finite-control-set model predictive control based on cost function reconstruction

Lei, Yanxiong,Du, Guiping,Zhang, Yuhan,Li, Tuhuan The Korean Institute of Power Electronics 2021 JOURNAL OF POWER ELECTRONICS Vol.21 No.6

Considering the spread spectrum problem of finite-control-set model predictive control (FCS-MPC), a fixed switching frequency strategy based on cost function reconstruction is proposed in this paper. It achieves a fixed switching frequency by selecting the optimal voltage vector through the redefined cost function. A frequency coefficient is added to this to change the selecting area of the optimal voltage vector. The proposed strategy reshapes the spectrum of the inductor current and focuses the harmonics near the switching frequency so that the design of the output LC filter is easier. Without adding any modulators or greatly increasing the number of computations, the proposed strategy reserves the excellent dynamic performance of the FCS-MPC and is convenient in terms of implementation. Finally, a 1 kW single-phase inverter is built and experiments are conducted. Experimental results demonstrate that the proposed control strategy realizes a fixed switching frequency. In addition, it has a comparative dynamic response speed and number of calculations when compared to dead-beat-based FCS-MPC. These features are beneficial to its application.