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Antioxidant Activities of Polyphenols Extracted from Perilla frutescens Varieties

Linghua Meng, Yves Lozano, Emile Gaydou, Bin Li
2008 Molecules  
Various cultivars of Perilla frutescens (L.) (var. crispa and var. frutescens) Britt. were harvested in China and Japan. They were easily differentiated on the basis of their foliage color, that varied from red to green. Water extracts of dried plants were investigated for their antioxidant activity (AA) and their polyphenolic compounds compared. Among them, cinnamic acid derivatives (coumaroyl tartaric acid, caffeic acid and rosmarinic acid), flavonoids (apigenin 7-O-caffeoylglucoside,
more » ... rein 7-Odiglucuronide, luteolin 7-O-diglucuronide, apigenin 7-O-diglucuronide, luteolin 7-Oglucuronide, and scutellarein 7-O-glucuronide) and anthocyanins (mainly cis-shisonin, shisonin, malonylshisonin and cyanidin 3-O-(E)-caffeoylglucoside-5-O-malonylglucoside) were quantified. AA assays are based on the inhibition of the free radical 2,2-diphenyl-1picrylhydrazyl (DPPH). The DPPH radical scavenging activity was calculated as Trolox ® [(±)-6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid] equivalent antioxidant capacity (TEAC). The mean amount of total phenolics of the water extracts (4-29 µmol/100 mL) and the TEAC value calculated (23-167 µmol TE/100 mL) confirmed the high antioxidant activity of these leaf water extracts. These results were highly correlated within some o-dihydroxylated polyphenolic compounds and AA.
doi:10.3390/molecules14010133 pmid:19127243 fatcat:6w4nu3hmpreadjihenrrwkpscy

Discovery of Indoleamine 2,3-Dioxygenase 1 (IDO-1) Inhibitors Based on Ortho-Naphthaquinone-Containing Natural Product

Hongchuan Zhao, Pu Sun, Wei Guo, Yi Wang, Ao Zhang, Linghua Meng, Chunyong Ding
2019 Molecules  
There is great interest in developing small molecules agents capable of reversing tumor immune escape to restore the body's immune system. As an immunosuppressive enzyme, indoleamine 2,3-dioxygenase 1 (IDO-1) is considered a promising target for oncology immunotherapy. Currently, none of IDO-1 inhibitors have been launched for clinical practice yet. Thus, the discovery of new IDO-1 inhibitors is still in great demand. Herein, a series of diverse ortho-naphthaquinone containing natural product
more » ... rivatives were synthesized as novel IDO-1 inhibitors. Among them, 1-ene-3-ketone-17-hydroxyl derivative 12 exhibited significantly improved enzymatic and cellular inhibitory activity against IDO-1 when compared to initial lead compounds. Besides, the molecular docking study disclosed that the two most potent compounds 11 and 12 have more interactions within the binding pocket of IDO-1 via hydrogen-bonding, which may account for their higher IDO-1 inhibitory activity.
doi:10.3390/molecules24061059 fatcat:ihigyyw5jfec3dnbiyw33y3oa4

Spatiotemporal Changes and Driving Factors of Cultivated Soil Organic Carbon in Northern China's Typical Agro-Pastoral Ecotone in the Last 30 Years

Liping Wang, Xiang Wang, Dianyao Wang, Beisong Qi, Shufeng Zheng, Huanjun Liu, Chong Luo, Houxuan Li, Linghua Meng, Xiangtian Meng, Yihao Wang
2021 Remote Sensing  
In order to explore the spatiotemporal changes and driving factors of soil organic carbon (SOC) in the agro-pastoral ecotone of northern China, we took Aohan banner, Chifeng City, Inner Mongolia Autonomous Region as the study area, used the random forest (RF) method to predict the SOC from 1989 to 2018, and the geographic detector method (GDM) was applied to analyze quantitatively the natural and anthropogenic factors that are affecting Aohan banner. The results indicated that: (1) After adding
more » ... the terrain factors, the R2 and residual predictive deviation (RPD) of the RF model increased by 1.178 and 0.39%, with root mean square errors (RMSEs) of 1.42 g/kg and 1.05 g/kg, respectively; (2) The spatial distribution of SOC was higher in the south and lower in the north; the negative growth of SOC accounted for 55.923% of the total area, showing a trend of degradation; (3) Precipitation was the main driving factor of SOC spatial variation in the typical agro-pastoral ecotone of northern China, which was also affected by temperature, elevation, soil type and soil texture (p < 0.01). (4). Anthropogenic factors (carbon input and gross domestic product (GDP)) had a greater impact on SOC than did climate factors (temperature and precipitation), making anthropogenic factors the dominant factors affecting SOC temporal variation (p < 0.01). The results of this work constitute a basis for a regional assessment of the temporal evolution of organic carbon in the soil surface, which is a key tool for monitoring the sustainable development of agropastoral ecotones.
doi:10.3390/rs13183607 fatcat:t3fmwu4cdfbjtbhylbdd2dkc64

A Three-Dimensional, Magnetic and Electroactive Nanoprobe for Amperometric Determination of Tumor Biomarkers

Linghua Meng, Ning Gan, Tianhua Li, Yuting Cao, Futao Hu, Lei Zheng
2011 International Journal of Molecular Sciences  
A novel electrochemical immunosensor for tumor biomarker detection based on three-dimensional, magnetic and electroactive nanoprobes was developed in this study. To fabricate the nanoprobes, negatively charged Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) and gold nanoparticles (Au NPs) were first loaded on the surface of multiple wall carbon nanotubes (MCNTs) which were functioned with redox-active hemin and cationic polyelectrolyte poly(dimethyldiallylammonium chloride) (PDDA). Using alpha
more » ... (AFP) as a model analyte, AFP antibody (anti-AFP) was absorbed on the surface of Au NPs, bovine serum albumin (BSA) was then used to block sites against non-specific binding, and finally formed anti-AFP/Au NPs/Fe 3 O 4 /hemin/MCNTs named anti-AFP nanoprobes. When the target antigen AFP was present, it interacted with anti-AFP and formed an antigenantibody complex on the nanoprobe interface. This resulted in a decreased electrochemical signal of hemin for quantitative determination of AFP when immobilized onto the screenprinted working electrode (SPCE). The results showed that the nanoprobe-based electrochemical immunosensor was sensitive to AFP detection at a concentration of 0.1 to 200 ngmL 1 with a detection limit of 0.04 ngmL 1 , it also demonstrated good selectivity against other interferential substances. The electroactive nanoprobes can be massively OPEN ACCESS Int. J. Mol. Sci. 2011, 12 363 prepared, easily immobilized on the SPCE for target detection and rapidly renewed with a magnet. The proposed immunosensor is fast, simple, sensitive, stable, magnet-controlled, nontoxic, label-free and reproducible.
doi:10.3390/ijms12010362 pmid:21339991 pmcid:PMC3039957 fatcat:te26p7ycy5efxe6y3vjunxaray

Sevoflurane may be more beneficial than propofol in patients receiving endoscopic variceal ligation and endoscopic variceal sclerotherapy: A randomized, double-blind study

Linghua Tang, Huimin Liu, Yang Wu, Mei Li, Wei Li, Meng Jiang, Jiabao Hou, Ying Jiang, Zhongyuan Xia, Qingtao Meng
2017 Experimental and Therapeutic Medicine  
The aim of the present study was to evaluate the safety and efficacy of various general anesthesia regimens during endoscopic variceal ligation (EVL) and endoscopic variceal sclerotherapy (EVS). A total of 123 patients with American Society of Anesthesiologists physical status III and IV, aged 40-70 years, undergoing general anesthesia for EVL and EVS were randomly divided into two groups: Sevoflurane anesthesia (group S; n=60) and propofol anesthesia (group P; n=60). Vital signs, particularly
more » ... eart rate (HR) and mean arterial pressure (MAP), were monitored. The designated time points were as follows: 5 min before induction (T0), and 1, 5, 10, 15, 20, 25 and 30 min after intubation (T1, T2, T3, T4, T5, T6 and T7, respectively). Time intervals were recorded, including recovery time and extubation time. Following surgery, the observer recorded the Ramsay sedation scale (RSS) score and the visual analogue scale (VAS) score. Adverse reactions were noted. Results demonstrated that there were significant differences in MAP between the two groups at T2, T3, T5, T6 and T7 (P<0.05). There was a significant difference in HR between the two groups at T2, T3 and T4 (P<0.05). Recovery time and extubation time in group P were significantly longer than those in group S (P<0.05; 18.38±2.25 min vs. 14.57±1.04 min and 21.70±2.70 min vs. 15.83±0.88 min, respectively). The rate of ephedrine injected was 58.3% (35/60 patients) in group P vs. 28.3% (17/60 patients) in group S (P<0.05). There was a significant difference in the RSS score between the two groups 5 min after extubation (P<0.05). VRS scores demonstrated that anesthetists and patients were significantly more satisfied with the procedure in group S than in group P (P<0.01). In conclusion, the superiority and special clinical value of inhalational anesthesia has been demonstrated during EVL and EVS attributed to stable hemodynamics and high quality of anesthesia recovery in the present study.
doi:10.3892/etm.2017.4919 pmid:28966686 pmcid:PMC5615208 fatcat:4poqu7lxfbhf7gf5enkg3sh2ha

Predicting Maize Yield at the Plot Scale of Different Fertilizer Systems by Multi-Source Data and Machine Learning Methods

Linghua Meng, Huanjun Liu, Susan L. Ustin, Xinle Zhang
2021 Remote Sensing  
Timely and reliable maize yield prediction is essential for the agricultural supply chain and food security. Previous studies using either climate or satellite data or both to build empirical or statistical models have prevailed for decades. However, to what extent climate and satellite data can improve yield prediction is still unknown. In addition, fertilizer information may also improve crop yield prediction, especially in regions with different fertilizer systems, such as cover crop,
more » ... fertilizer, or compost. Machine learning (ML) has been widely and successfully applied in crop yield prediction. Here, we attempted to predict maize yield from 1994 to 2007 at the plot scale by integrating multi-source data, including monthly climate data, satellite data (i.e., vegetation indices (VIs)), fertilizer data, and soil data to explore the accuracy of different inputs to yield prediction. The results show that incorporating all of the datasets using random forests (RF) and AB (adaptive boosting) can achieve better performances in yield prediction (R2: 0.85~0.98). In addition, the combination of VIs, climate data, and soil data (VCS) can predict maize yield more effectively than other combinations (e.g., combinations of all data and combinations of VIs and soil data). Furthermore, we also found that including different fertilizer systems had different prediction accuracies. This paper aggregates data from multiple sources and distinguishes the effects of different fertilization scenarios on crop yield predictions. In addition, the effects of different data on crop yield were analyzed in this study. Our study provides a paradigm that can be used to improve yield predictions for other crops and is an important effort that combines multi-source remotely sensed and environmental data for maize yield prediction at the plot scale and develops timely and robust methods for maize yield prediction grown under different fertilizing systems.
doi:10.3390/rs13183760 fatcat:sl5pz4rytrhkxga5ddvxblk3ni

An Innovative Approach for Improving the Accuracy of Digital Elevation Models for Cultivated Land

Yuyang Ma, Huanjun Liu, Baiwen Jiang, Linghua Meng, Haixiang Guan, Mengyuan Xu, Yang Cui, Fanchang Kong, Yue Yin, MengPei Wang
2020 Remote Sensing  
The redistribution of solar radiation, temperature, soil moisture and heat by topography affects the physical and chemical properties of the soil and the spatial distribution characteristics of crop growth. Analyses of the relationship between topography and these variables may help to improve the accuracy of digital elevation models (DEMs). The purpose of correcting Shuttle Radar Topography Mission (SRTM) data is to obtain high-precision DEM data in cultivated land. A typical black soil area
more » ... s studied. A high-precision reference DEM was generated from an unmanned aerial vehicle (UAV) and extensive measured ground elevation data. The normalized differential vegetation index (NDVI), perpendicular drought index (PDI) extracted from SPOT-6 remote sensing images and potential solar radiation (PSR) extracted from SRTM. The interactions between topography and NDVI, PDI, and PSR were analyzed. The NDVI, PDI and PSR in June, July, August and September of 2016 and the SRTM were used as independent variables, and the UAV DEM was used as the dependent variable. Linear stepwise regression (LSR) and a back-propagation neural network (BPNN) were used to establish an elevation prediction model. The results indicated that 1) The correlation between topography and NDVI, PSR, PDI was significant at 0.01 level. The PDI and PSR improved the spatial resolution of SRTM data and reduce the vertical error. 2) The BPNN (R21 = 0.98, root mean square error, RMSE1 = 0.54) yielded a higher SRTM accuracy than did the studied linear model (RMSE1 = 1.00, R21 = 0.90). 3) A series of significant improvements in the SRTM were observed when assessed with the reference DEMs for two different areas, with RMSE reductions of 91% (from 14.95 m to 1.23 m) and 93% (from 15.6 m to 0.94 m). The proposed method improved the accuracy of existing DEMs and could provide support for accurate farmland management.
doi:10.3390/rs12203401 fatcat:2tnc2hcnzre5plwa3o2srip6wm

Identification of a Non-Gatekeeper Hot Spot for Drug-Resistant Mutations in mTOR Kinase

Tzung-Ju Wu, Xiaowen Wang, Yanjie Zhang, Linghua Meng, John E. Kerrigan, Stephen K. Burley, X.F. Steven Zheng
2015 Cell Reports  
Graphical Abstract Highlights d L2185 of mTOR kinase is a hot spot for drug-resistant mutations d The "gatekeeper" residue does not confer drug resistance d A three-ring heterocyclic chemical structure is refractory to drug resistance d C-and R-spines of mTOR kinase are crucial for its catalytic function Wu et al., 2015, Cell Reports 11, 446-459 April 21, 2015 ª2015 The Authors http://dx.
doi:10.1016/j.celrep.2015.03.040 pmid:25865887 pmcid:PMC4761412 fatcat:q3ehf3gajbgrnc5hzwz7rusjfm

Assessment of FSDAF Accuracy on Cotton Yield Estimation Using Different MODIS Products and Landsat Based on the Mixed Degree Index with Different Surroundings

Linghua Meng, Huanjun Liu, Susan L. Ustin, Xinle Zhang
2021 Sensors  
Research on fusion modeling of high spatial and temporal resolution images typically uses MODIS products at 500 m and 250 m resolution with Landsat images at 30 m, but the effect on results of the date of reference images and the 'mixed pixels' nature of moderate-resolution imaging spectroradiometer (MODIS) images are not often considered. In this study, we evaluated those effects using the flexible spatiotemporal data fusion model (FSDAF) to generate fusion images with both high spatial
more » ... ion and frequent coverage over three cotton field plots in the San Joaquin Valley of California, USA. Landsat images of different dates (day-of-year (DOY) 174, 206, and 254, representing early, middle, and end stages of the growing season, respectively) were used as reference images in fusion with two MODIS products (MOD09GA and MOD13Q1) to produce new time-series fusion images with improved temporal sampling over that provided by Landsat alone. The impact on the accuracy of yield estimation of the different Landsat reference dates, as well as the degree of mixing of the two MODIS products, were evaluated. A mixed degree index (MDI) was constructed to evaluate the accuracy and time-series fusion results of the different cotton plots, after which the different yield estimation models were compared. The results show the following: (1) there is a strong correlation (above 0.6) between cotton yield and both the Normalized Difference Vegetation Index (NDVI) from Landsat (NDVIL30) and NDVI from the fusion of Landsat with MOD13Q1 (NDVIF250). (2) Use of a mid-season Landsat image as reference for the fusion of MODIS imagery provides a better yield estimation, 14.73% and 17.26% higher than reference images from early or late in the season, respectively. (3) The accuracy of the yield estimation model of the three plots is different and relates to the MDI of the plots and the types of surrounding crops. These results can be used as a reference for data fusion for vegetation monitoring using remote sensing at the field scale.
doi:10.3390/s21155184 fatcat:vurtsndap5g5pkuznzxfnisbvi

PI3Kα inhibitor impairs AKT phosphorylation and synergizes with novel angiogenesis inhibitor AL3810 in human hepatocellular carcinoma

Qin Xie, Shuaishuai Chi, Yanfen Fang, Yiming Sun, Linghua Meng, Jian Ding, Yi Chen
2021 Signal Transduction and Targeted Therapy  
doi:10.1038/s41392-021-00522-6 pmid:33785733 pmcid:PMC8010115 fatcat:4dpr6edpejbbniqs3a75og3m2u

New Insights into PI3K Inhibitor Design using X-ray Structures of PI3Kα Complexed with a Potent Lead Compound

Xiuyan Yang, Xi Zhang, Min Huang, Kun Song, Xuefen Li, Meilang Huang, Linghua Meng, Jian Zhang
2017 Scientific Reports  
Meng 3 & Jian Zhang 1,2 Figure 1 . 1 Structure of Thieno[3,2-d]pyrimidine Derivative YXY-4F, 9d and PI 103.  ...  The IC 50 values 43 were calculated by fitting the data to a logistic curve using the GraphPad Prism 6 software. 1,2 , Xi Zhang 3 , Min Huang 2,5 , Kun Song 2 , Xuefen Li 3 , Meilang Huang 4 , Linghua  ... 
doi:10.1038/s41598-017-15260-5 pmid:29109464 pmcid:PMC5674032 fatcat:r2evr6aql5ay7cdqm5qp2gj3jm

The Marine-Derived Oligosaccharide Sulfate (MdOS), a Novel Multiple Tyrosine Kinase Inhibitor, Combats Tumor Angiogenesis both In Vitro and In Vivo

Jingui Ma, Xianliang Xin, Linghua Meng, Linjiang Tong, Liping Lin, Meiyu Geng, Jian Ding, Mikhail V. Blagosklonny
2008 PLoS ONE  
Despite the emerging success of multi-targeted protein tyrosine kinase (PTK) inhibitors in cancer therapy, significant side effects and resistance concerns seems to be avoided unlikely. The aim of the present study was to identify novel multitargeting PTK inhibitors. The kinase enzymatic activities were measured by enzyme-linked immunosorbent assay (ELISA). The antiproliferative activities in human microvascular endothelial cells (HMECs) were evaluated by sulforhodamine (SRB) assay. The
more » ... ylation of kinases and their downstream molecules was probed by western blot analysis. The binding mode between MdOS and PTKs was profiled by surface plasmon resonance (SPR) approach and molecular simulation. Tube formation assay, rat aortic ring method and chicken chorioallantoic membrane assay were combined to illustrate the in vitro and in vivo anti-angiogenic effects. Results indicated that MdOS, a novel marine-derived oligosaccharide sulfate, exhibited a broad-spectrum PTK inhibitory action. At an enzymatic level, MdOS inhibited HER2, EGFR, VEGFR, PDGFR, c-Kit, FGFR1 and c-Src, with little impact on FGFR2. In cellular settings, MdOS inhibited phosphorylation of PTKs, exemplified by HER2, EGFR and VEGFR2, and downstream molecules of Erk1/2 and AKT. Further studies demonstrated that MdOS acted as an ATPcompetitive inhibitor via directly binding to the residues of entrance rather than those of the ATP-binding pocket. Furthermore, MdOS inhibited proliferation and tube formation of HMECs, arrested microvessel outgrowth of rat aortic rings and hindered the neovascularization of chick allantoic membrane. Taken together, results presented here indicated that MdOS exhibited anti-angiogenic activity in a PTK-dependent manner and make it a promising agent for further evaluation in PTK-associated cancer therapy.
doi:10.1371/journal.pone.0003774 pmid:19020661 pmcid:PMC2582481 fatcat:e7qdapgi4vdclbrkrepyf7oyg4

Rhodamine B derivatives-modified upconversion nanoparticles as a fluorescent turn-off–on sensor for the highly sensitive detection of Cu2+ and pyrophosphate

Zhipeng Meng, Suli Wu, Linghua Zhong, Min Zeng, Xiaoqian Sun, Lu Li, Shufen Zhang
2018 RSC Advances  
A new fluorescent turn-off–on sensor was developed based on the the rhodamine B derivatives (RBP) modified UCNPs to detect Cu2+ and pyrophosphate (PPi).
doi:10.1039/c8ra08090a pmid:35558582 pmcid:PMC9089887 fatcat:k5yj73c67zer7o72gc75vzr3um

Simultaneous inhibition of PI3Kα and CDK4/6 synergistically suppresses KRAS-mutated non-small cell lung cancer

Wang Yuxiang, Li Xian, Liu Xueling, Chen Yi, Yang Chunhao, Tan Cun, Wang Bobo, Sun Yiming, Zhang Xi, Gao Yinglei, Ding Jian, Meng Linghua
2019 Cancer Biology and Medicine  
Activating KRAS mutations are the most common drivers in the development of non-small cell lung cancer (NSCLC). However, unsuccess of treatment by direct inhibition of KRAS has been proven. Deregulation of PI3K signaling plays an important role in tumorigenesis and drug resistance in NSCLC. The activity of PI3Kα-selective inhibition against KRAS-mutated NSCLC remains largely unknown. Cell proliferation was detected by sulforhodamine B assay. Cell cycle distribution and apoptosis were measured
more » ... flow cytometry. Cell signaling was assessed by Western blot and immunohistochemistry. RNA interference was used to down-regulate the expression of cyclin D1. Human NSCLC xenografts were employed to detect therapeutic efficacy in vivo. CYH33 possessed variable activity against a panel of KRAS-mutated NSCLC cell lines. Although CYH33 blocked AKT phosphorylation in all tested cells, Rb phosphorylation decreased in CYH33-sensitive, but not in CYH33-resistant cells, which was consistent with G1 phase arrest in sensitive cells. Combined treatment with the CDK4/6 inhibitor, PD0332991, and CYH33 displayed synergistic activity against the proliferation of both CYH33-sensitive and CYH33-resistant cells, which was accompanied by enhanced G1-phase arrest. Moreover, down-regulation of cyclin D1 sensitized NSCLC cells to CYH33. Reciprocally, CYH33 abrogated the PD0332991-induced up-regulation of cyclin D1 and phosphorylation of AKT in A549 cells. Co-treatment with these two drugs demonstrated synergistic activity against A549 and H23 xenografts, with enhanced inhibition of Rb phosphorylation. Simultaneous inhibition of PI3Kα and CDK4/6 displayed synergistic activity against KRAS-mutated NSCLC. These data provide a mechanistic rationale for the combination of a PI3Kα inhibitor and a CDK4/6 inhibitor for the treatment of KRAS-mutated NSCLC.
doi:10.20892/j.issn.2095-3941.2018.0361 pmid:31119047 pmcid:PMC6528459 fatcat:egpdsglh7jgo3lykyvrw2gco4y

Erratum to Simultaneous inhibition of PI3Kα and CDK4/6 synergistically suppresses KRAS-mutated non-small cell lung cancer

Yuxiang Wang, Xian Li, Xueling Liu, Yi Chen, Chunhao Yang, Cun Tan, Bobo Wang, Yiming Sun, Xi Zhang, Yinglei Gao, Jian Ding, Linghua Meng
2019 Cancer Biology and Medicine  
Figure 1B NSCLC cells were treated with CYH33 at the indicated concentrations for 1 h. Cell lysates were subjected to Western blot with the indicated antibodies.
doi:10.20892/j.issn.2095-3941.2019.0401 pmid:31908900 pmcid:PMC6936228 fatcat:yboiruxzq5b3ldgxwp3jzgoa6u
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