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  1. Book ; Online: Variational Inference

    Li, Xuezhen / Le, Can M.

    Posterior Threshold Improves Network Clustering Accuracy in Sparse Regimes

    2023  

    Abstract: Variational inference has been widely used in machine learning literature to fit various Bayesian models. In network analysis, this method has been successfully applied to solve the community detection problems. Although these results are promising, ... ...

    Abstract Variational inference has been widely used in machine learning literature to fit various Bayesian models. In network analysis, this method has been successfully applied to solve the community detection problems. Although these results are promising, their theoretical support is only for relatively dense networks, an assumption that may not hold for real networks. In addition, it has been shown recently that the variational loss surface has many saddle points, which may severely affect its performance, especially when applied to sparse networks. This paper proposes a simple way to improve the variational inference method by hard thresholding the posterior of the community assignment after each iteration. Using a random initialization that correlates with the true community assignment, we show that the proposed method converges and can accurately recover the true community labels, even when the average node degree of the network is bounded. Extensive numerical study further confirms the advantage of the proposed method over the classical variational inference and another state-of-the-art algorithm.
    Keywords Statistics - Machine Learning ; Computer Science - Machine Learning
    Subject code 006
    Publishing date 2023-01-11
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  2. Article ; Online: Impact of sex and serum lipids interaction on working memory: A large-scale brain networks study.

    Zhang, Shujun / Li, Xuezhen / Sun, Zhanguo / Chen, Yueqin / Yu, Yongqiang

    Brain and behavior

    2023  Volume 13, Issue 7, Page(s) e3054

    Abstract: Backgrounds: Previous studies have demonstrated that both serum lipid levels and sex are crucial factors associated with individual cognition. However, the impact of sex and serum lipid interaction effects on the brain and cognition remains largely ... ...

    Abstract Backgrounds: Previous studies have demonstrated that both serum lipid levels and sex are crucial factors associated with individual cognition. However, the impact of sex and serum lipid interaction effects on the brain and cognition remains largely unknown. This study aimed to explore the underlying neural mechanisms among sex, serum lipids, and cognition using large-scale brain networks.
    Methods: Resting-state functional MRI data were collected from 157 young healthy adults. Independent component analysis was used to examine large-scale inter- and intra-network functional connectivity (FCs). Peripheral venous blood samples were collected to measure serum lipid levels. The three-back task was employed to assess cognition (i.e., working memory). General linear model, correlation, and mediation analyses were conducted to examine the interaction effects of sex and serum lipids on large-scale brain networks and their relationship with working memory.
    Results: We found that inter-network connectivity with the executive control network at its core was more susceptible to sex and triglyceride interaction effects. The intra-network connectivity in the dorsal attention networks (DANs), lateral visual networks, and anterior default mode networks was influenced by the interaction effects of sex and total cholesterol (TC)/low-density lipoprotein cholesterol. Specifically, correlations between serum lipids and affected brain networks were found to be sex-specific. In addition, higher intra-network FC in the right inferior parietal (R-IPL) of the DAN correlated with a longer three-back reaction time in females. More importantly, the relationship between serum TC levels and three-back reaction time was mediated by intra-network connectivity in the R-IPL of the DAN.
    Conclusions: Our findings describe the impact of sex and serum lipid interaction effects on large-scale brain networks, as well as on cognitive function. Our data suggest that sex-specific usage of serum lipids or brain networks would be beneficial for monitoring and therapy in dyslipidemia-related cognition decline.
    MeSH term(s) Male ; Adult ; Female ; Humans ; Memory, Short-Term ; Brain Mapping ; Neural Pathways ; Brain/diagnostic imaging ; Cognition ; Cholesterol ; Lipids ; Magnetic Resonance Imaging ; Nerve Net/diagnostic imaging
    Chemical Substances Cholesterol (97C5T2UQ7J) ; Lipids
    Language English
    Publishing date 2023-05-10
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2623587-0
    ISSN 2162-3279 ; 2162-3279
    ISSN (online) 2162-3279
    ISSN 2162-3279
    DOI 10.1002/brb3.3054
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article: I2/CH3ONa-Promoted Ring-Opening Alkylation of Benzothiazoles with Dialkyl Carbonates

    Li, Xuezhen / He, Jing / Xie, Jianwei / Liu, Ping

    Synthesis

    2022  Volume 55, Issue 04, Page(s) 609–616

    Abstract: Dialkyl carbonates were used as the green alkylating reagents in the I 2 -promoted ring-opening alkylation of benzothiazoles. A variety of benzo[ d ]thiazole derivatives underwent the alkylation smoothly to provide the diverse N -alkyl- N o -alkylthio) ... ...

    Abstract Dialkyl carbonates were used as the green alkylating reagents in the I 2 -promoted ring-opening alkylation of benzothiazoles. A variety of benzo[ d ]thiazole derivatives underwent the alkylation smoothly to provide the diverse N -alkyl- N o -alkylthio)phenylformamides in moderate to excellent yields. The synthetic utility of this protocol was verified by gram-scale reaction and further derivatization of the products. The mechanism of the involvement of two molecules of dialkyl carbonates in the formation of sulfur-alkyl and nitrogen-alkyl groups, respectively, was also demonstrated.
    Keywords alkylation ; benzothiazole ; dialkyl carbonate ; ring-opening ; iodine
    Language English
    Publishing date 2022-11-03
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article
    ZDB-ID 2033062-5
    ISSN 1437-210X ; 0039-7881
    ISSN (online) 1437-210X
    ISSN 0039-7881
    DOI 10.1055/s-0042-1752356
    Database Thieme publisher's database

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  4. Article ; Online: Exploring the Risk Thresholds of Soil Heavy Metals in Carbonate and Non-carbonate Rock Areas: The Case of Qianjiang District in Chongqing, China

    Wang, Xiang / Li, Xuezhen / Zhou, Xiaozhen / Sheng, Weikang / Lin, Kun / Ma, Xudong

    Bull Environ Contam Toxicol. 2022 Nov., v. 109, no. 5 p.910-919

    2022  

    Abstract: To determine whether the national soil heavy metal standards (GB 15618-2018) are applicable to some carbonate and non-carbonate zones in Southwest China, rice and rhizosphere soil samples were collected in Chongqing and analyzed for heavy metal contents, ...

    Abstract To determine whether the national soil heavy metal standards (GB 15618-2018) are applicable to some carbonate and non-carbonate zones in Southwest China, rice and rhizosphere soil samples were collected in Chongqing and analyzed for heavy metal contents, pH, and other chemical parameters. In addition, regression analysis was also used to predict the risk threshold of soil heavy metals. The Cd risk screening value in GB 15618-2018 was strict for alkaline soils (pH > 7.5) as compared to those revealed in carbonate and non-carbonate areas, while the calculated pollution threshold for Cd in acidic soils (pH ≤ 5.5) in the non-carbonate area was lower than that in GB 15618-2018. Therefore, to improve the applicability of the evaluation results, a soil-crop system evaluation is recommended.
    Keywords bulls ; carbonates ; heavy metals ; pH ; pollution ; regression analysis ; rhizosphere ; rice ; risk ; soil ; China
    Language English
    Dates of publication 2022-11
    Size p. 910-919.
    Publishing place Springer US
    Document type Article ; Online
    ZDB-ID 6895-0
    ISSN 1432-0800 ; 0007-4861
    ISSN (online) 1432-0800
    ISSN 0007-4861
    DOI 10.1007/s00128-022-03580-w
    Database NAL-Catalogue (AGRICOLA)

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  5. Article ; Online: Exploring the Risk Thresholds of Soil Heavy Metals in Carbonate and Non-carbonate Rock Areas: The Case of Qianjiang District in Chongqing, China.

    Wang, Xiang / Li, Xuezhen / Zhou, Xiaozhen / Sheng, Weikang / Lin, Kun / Ma, Xudong

    Bulletin of environmental contamination and toxicology

    2022  Volume 109, Issue 5, Page(s) 910–919

    Abstract: To determine whether the national soil heavy metal standards (GB 15618-2018) are applicable to some carbonate and non-carbonate zones in Southwest China, rice and rhizosphere soil samples were collected in Chongqing and analyzed for heavy metal contents, ...

    Abstract To determine whether the national soil heavy metal standards (GB 15618-2018) are applicable to some carbonate and non-carbonate zones in Southwest China, rice and rhizosphere soil samples were collected in Chongqing and analyzed for heavy metal contents, pH, and other chemical parameters. In addition, regression analysis was also used to predict the risk threshold of soil heavy metals. The Cd risk screening value in GB 15618-2018 was strict for alkaline soils (pH > 7.5) as compared to those revealed in carbonate and non-carbonate areas, while the calculated pollution threshold for Cd in acidic soils (pH ≤ 5.5) in the non-carbonate area was lower than that in GB 15618-2018. Therefore, to improve the applicability of the evaluation results, a soil-crop system evaluation is recommended.
    MeSH term(s) Soil/chemistry ; Soil Pollutants/analysis ; Cadmium/analysis ; Environmental Monitoring ; Risk Assessment ; Metals, Heavy/analysis ; China
    Chemical Substances Soil ; Soil Pollutants ; Cadmium (00BH33GNGH) ; Metals, Heavy
    Language English
    Publishing date 2022-08-01
    Publishing country United States
    Document type Journal Article
    ZDB-ID 6895-0
    ISSN 1432-0800 ; 0007-4861
    ISSN (online) 1432-0800
    ISSN 0007-4861
    DOI 10.1007/s00128-022-03580-w
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: The Protective Effect of Exogenous Ascorbic Acid on Photosystem Inhibition of Tomato Seedlings Induced by Salt Stress.

    Chen, Xianjun / Han, Hongwei / Cong, Yundan / Li, Xuezhen / Zhang, Wenbo / Wan, Wenliang / Cui, Jinxia / Xu, Wei / Diao, Ming / Liu, Huiying

    Plants (Basel, Switzerland)

    2023  Volume 12, Issue 6

    Abstract: This study investigated the protective effects of exogenous ascorbic acid (AsA, 0.5 mmol· ... ...

    Abstract This study investigated the protective effects of exogenous ascorbic acid (AsA, 0.5 mmol·L
    Language English
    Publishing date 2023-03-20
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2704341-1
    ISSN 2223-7747
    ISSN 2223-7747
    DOI 10.3390/plants12061379
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article: The positive effects of exogenous sodium nitroprusside on the plant growth, photosystem II efficiency and Calvin cycle of tomato seedlings under salt stress

    Li, Xuezhen / Wang, Song / Chen, Xianjun / Cong, Yundan / Cui, Jinxia / Shi, Qinghua / Liu, Huiying / Diao, Ming

    Scientia horticulturae. 2022 June 01, v. 299

    2022  

    Abstract: Although some studies have shown that exogenous sodium nitroprusside (SNP, an NO donor) participates in the tolerance of plants to stress, the protective role of the level of SNP-mediated endogenous nitrous oxide (NO) on the salt-induced inhibition of ... ...

    Abstract Although some studies have shown that exogenous sodium nitroprusside (SNP, an NO donor) participates in the tolerance of plants to stress, the protective role of the level of SNP-mediated endogenous nitrous oxide (NO) on the salt-induced inhibition of photosynthesis in salt-stressed tomato seedlings merits understanding. Thus, in this study, with the exception of tomato seedlings treated with 0 or 100 mmol· L⁻¹ NaCl alone or together with 0.1 mmol· L⁻¹ SNP, 100 μmol· L⁻¹ 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO, an NO scavenger) and 100 μmol· L⁻¹ N-nitro-L-arginine methyl ester (L-NAME, an inhibitor of NO synthase) was applied jointly to saline-stressed tomato seedlings by a foliage spray of 0.1 mmol· L⁻¹ SNP, respectively. The application of SNP counteracted the saline-induced growth inhibition and the reduction in net photosynthetic rate of tomato seedlings by enhancing their stomatal conductance, intercellular CO₂ concentration, apparent photosynthetic quantum efficiency, PSII maximum photochemical efficiency, actual photochemical efficiency of PSII, non-photochemical quenching coefficient, and a decrease in the dark respiration rate, which is coupled with an increase in the endogenous levels of NO. In addition, treatment with SNP increases the maximum carboxylation rate of ribulose-1,5-bisphosphate carboxylase (Rubisco), the maximum regeneration rate of ribulose-1,5-bisphosphate (RuBP) and the upregulated total and initial activity of Rubisco; the activity in Rubisco activase and fructose-1,6-bisphosphate phosphatase; and the transcriptions of genes that encode Rubisco activase, the Rubisco large subunit, and the Rubisco small subunit, and sedoheptulose-1,7-bisphosphatase, 3-phosphogiyceric acid kinase, transketolase and ribulose-5-phosphate kinase, which are the key enzymes involved in the Calvin-Benson cycle. However, the positive effect of SNP was impaired by the application of PTIO and L-NAME to eliminate the generation of endogenous NO, respectively. Our findings conclusively revealed that SNP triggers the upregulation of endogenous NO signal, which, in turn, conferred tolerance to salinity in tomato seedlings and positively regulated photosynthesis by overcoming stomatal limitations, enhancing the efficiency of photosystem II and maintaining the activation states of the Calvin-Benson cycle through the regulation of gene expressions and activities of key CO₂ assimilation enzymes.
    Keywords Calvin cycle ; carbon dioxide ; carboxylation ; cell respiration ; growth retardation ; leaves ; nitroprusside ; nitrous oxide ; photochemistry ; photosystem II ; plant growth ; protective effect ; ribulose-bisphosphate carboxylase ; ribulose-bisphosphate carboxylase activase ; salt stress ; salt tolerance ; stomatal conductance ; tomatoes ; transketolase
    Language English
    Dates of publication 2022-0601
    Publishing place Elsevier B.V.
    Document type Article
    ZDB-ID 185557-8
    ISSN 0304-4238
    ISSN 0304-4238
    DOI 10.1016/j.scienta.2022.111016
    Database NAL-Catalogue (AGRICOLA)

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  8. Article: Synthesis of novel 4-substituted 1,2,3-thiadiazoles via iodine-catalyzed cyclization reactions

    Li, Weiwei / Li, Xuezhen / Feng, Yijiao / Liu, Ping / Ma, Xiaowei / Zhao, Jixing

    Tetrahedron letters. 2021 Mar. 02, v. 66

    2021  

    Abstract: Iodine-catalyzed the reaction of substituted methyl ketone N-tosylhydrazones with elemental sulfur has been developed. The cyclizations of the ester-substituted N-tosylhydrazone substrates proceeded smoothly under optimal reaction conditions, and the ... ...

    Abstract Iodine-catalyzed the reaction of substituted methyl ketone N-tosylhydrazones with elemental sulfur has been developed. The cyclizations of the ester-substituted N-tosylhydrazone substrates proceeded smoothly under optimal reaction conditions, and the corresponding products 4-alkyl-1, 2, 3-thiadiazoles are obtained. For the reaction of 4-arylbutan-2-one of N-tosylhydrazone substrates, (E)-4-styryl-1, 2, 3-thiadiazole derivatives were obtained with high selectivity through the control of reaction conditions. In addition, gram-scale synthesis and further transformation of the product were also investigated.
    Keywords cyclization reactions ; sulfur ; synthesis
    Language English
    Dates of publication 2021-0302
    Publishing place Elsevier Ltd
    Document type Article
    Note NAL-light
    ZDB-ID 204287-3
    ISSN 1873-3581 ; 0040-4039
    ISSN (online) 1873-3581
    ISSN 0040-4039
    DOI 10.1016/j.tetlet.2021.152824
    Database NAL-Catalogue (AGRICOLA)

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  9. Article ; Online: Prediction of cadmium contents in rice grains from Quaternary sediment-distributed farmland using field investigations and machine learning

    Ma, Xudong / Yu, Tao / Guan, Dong-Xing / Li, Cheng / Li, Bo / Liu, Xu / Lin, Kun / Li, Xuezhen / Wang, Lei / Yang, Zhongfang

    Science of the Total Environment. 2023 July 17, p.165482-

    2023  , Page(s) 165482–

    Abstract: The Quaternary sediment-distributed regions of South China are suitable for rice cultivation, which is crucial for ensuring food security. Spatial correlations between soil cadmium (Cd) and rice Cd contents are generally poor, making the evaluation of ... ...

    Abstract The Quaternary sediment-distributed regions of South China are suitable for rice cultivation, which is crucial for ensuring food security. Spatial correlations between soil cadmium (Cd) and rice Cd contents are generally poor, making the evaluation of rice quality and associated health risks challenging. In this study, we developed machine learning models for predicting rice Cd contents using 654 data pairs of soil-rice samples collected in Guangxi province, China. After a comprehensive comparison, our results showed that the random forest (RF) had the better performance than artificial neural network (ANN) based on all the data (RMSEₜₑₛₜᵢₙg 0.066 vs. 0.099 and R²ₜₑₛₜᵢₙg 0.860 vs. 0.688). The feature importance analysis showed that soil CaO, Cd, elevation, and rainfall were the four most important features affecting the rice Cd contents in the study area. Using the established RF-predicated model, the rice Cd contents were predicted at the provincial level with an additional dataset of 1176 paddy soil samples. The prediction result revealed about 23 % of farmland cultivated rice with Cd content over 0.2 mg kg⁻¹ in the study area. Therefore, it is recommended to implement strict measures by local agricultural departments to reduce rice Cd contents and ensure food safety in these areas. Our study provides valuable insights into the prediction of rice Cd contents, thus contributing to ensuring food safety and preventing Cd exposure-associated health risks.
    Keywords agricultural land ; cadmium ; calcium oxide ; data collection ; environment ; food safety ; food security ; neural networks ; paddy soils ; prediction ; rain ; rice ; China ; Random forest ; Artificial neural network ; Regional prediction ; Hyperparameter optimization
    Language English
    Dates of publication 2023-0717
    Publishing place Elsevier B.V.
    Document type Article ; Online
    Note Pre-press version
    ZDB-ID 121506-1
    ISSN 1879-1026 ; 0048-9697
    ISSN (online) 1879-1026
    ISSN 0048-9697
    DOI 10.1016/j.scitotenv.2023.165482
    Database NAL-Catalogue (AGRICOLA)

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  10. Article: Atractylenolide-I Sensitizes Triple-Negative Breast Cancer Cells to Paclitaxel by Blocking CTGF Expression and Fibroblast Activation.

    Wang, Meng / Li, Xue-Zhen / Zhang, Ming-Xing / Ye, Qian-Yu / Chen, Ying-Xia / Chang, Xu

    Frontiers in oncology

    2021  Volume 11, Page(s) 738534

    Abstract: This investigation was conducted to elucidate whether atractylenolide-I (ATL-1), which is the main component of Atractylodes macrocephala Koidz, can sensitize triple-negative breast cancer (TNBC) cells to paclitaxel and investigate the possible mechanism ...

    Abstract This investigation was conducted to elucidate whether atractylenolide-I (ATL-1), which is the main component of Atractylodes macrocephala Koidz, can sensitize triple-negative breast cancer (TNBC) cells to paclitaxel and investigate the possible mechanism involved. We discovered that ATL-1 could inhibit tumor cell migration and increase the sensitivity of tumor cells to paclitaxel. ATL-1 downregulated the expression and secretion of CTGF in TNBC cells. Apart from inhibiting TNBC cell migration
    Language English
    Publishing date 2021-10-06
    Publishing country Switzerland
    Document type Journal Article
    ZDB-ID 2649216-7
    ISSN 2234-943X
    ISSN 2234-943X
    DOI 10.3389/fonc.2021.738534
    Database MEDical Literature Analysis and Retrieval System OnLINE

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