213 research outputs found

    Undergraduatesā€™ Self-reported Learning Outcomes of General Education Courses: A Case Study of a Chinese Elite University

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    Based on a conceptual framework of college impact, this article studies the impact of gender, graduation paths, family cultural capital and disciplines on undergraduatesā€™ self-reported learning outcomes of general education courses. The conclusions are as follows: female students report significantly higher learning outcomes of general education courses than male students; students who will enter the labor market after graduation report significantly higher learning outcomes of general education courses than students who will enter graduate school; students majoring in social sciences report higher learning outcomes of general education courses than students from other disciplines. Familial cultural capital has no significant influence on undergraduatesā€™ self-reported learning outcomes of general education courses. This article makes exploratory explanations of the above results from two perspectives

    ChemRL-GEM: Geometry Enhanced Molecular Representation Learning for Property Prediction

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    Effective molecular representation learning is of great importance to facilitate molecular property prediction, which is a fundamental task for the drug and material industry. Recent advances in graph neural networks (GNNs) have shown great promise in applying GNNs for molecular representation learning. Moreover, a few recent studies have also demonstrated successful applications of self-supervised learning methods to pre-train the GNNs to overcome the problem of insufficient labeled molecules. However, existing GNNs and pre-training strategies usually treat molecules as topological graph data without fully utilizing the molecular geometry information. Whereas, the three-dimensional (3D) spatial structure of a molecule, a.k.a molecular geometry, is one of the most critical factors for determining molecular physical, chemical, and biological properties. To this end, we propose a novel Geometry Enhanced Molecular representation learning method (GEM) for Chemical Representation Learning (ChemRL). At first, we design a geometry-based GNN architecture that simultaneously models atoms, bonds, and bond angles in a molecule. To be specific, we devised double graphs for a molecule: The first one encodes the atom-bond relations; The second one encodes bond-angle relations. Moreover, on top of the devised GNN architecture, we propose several novel geometry-level self-supervised learning strategies to learn spatial knowledge by utilizing the local and global molecular 3D structures. We compare ChemRL-GEM with various state-of-the-art (SOTA) baselines on different molecular benchmarks and exhibit that ChemRL-GEM can significantly outperform all baselines in both regression and classification tasks. For example, the experimental results show an overall improvement of 8.8% on average compared to SOTA baselines on the regression tasks, demonstrating the superiority of the proposed method

    Impact Analysis of Energy Storage Participating in Peak Shaving and Valley Filling for Distribution Network on Network Loss and Voltage Deviation

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    [Introduction] The application scenarios of peak shaving and valley filling by energy storage connected to the distribution network are studied to clarify the influence of energy storage access on network losses and voltage quality on the distribution network side. [Method] The paper analyzed the change trend of network loss power with the energy storage injection current and access position during peak hours of energy storage discharge, and then analyzed the change trend of network loss power with the energy storage injection current and access position when the energy storage system was connected and charged during valley hours. For the influence of energy storage connected to the distribution network for peak shaving and valley filling on the voltage of the distribution network, the influence of different energy storage injection currents and access positions on the voltage distribution along the distribution network was studied from the perspective of energy storage discharge during peak hours and energy storage charging during valley hours. Finally, considering the total voltage deviation index of the distribution network, the influence on the total voltage deviation index after the distribution network which was connected to energy storage was studied. [Result] Through simulation calculations, the influence trend of energy storage participating in peak shaving and valley filling for the distribution network on network loss power and voltage loss is analyzed when different fixed or continuous values of energy storage current and access position are taken, and it is compared with theoretical analysis. [Conclusion] The study will provide useful references for the coordinated planning and optimized operation of various energy storage facilities in the distribution network, and it has good engineering reference value

    Linifanib (ABT-869) Potentiates the Efficacy of Chemotherapeutic Agents through the Suppression of Receptor Tyrosine Kinase-Mediated AKT/mTOR Signaling Pathways in Gastric Cancer

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    Gastric cancer, highly dependent on tumor angiogenesis, causes uncontrolled lethality, in part due to chemoresistance. Here, we demonstrate that linifanib (ABT-869), a novel multi-targeted receptor tyrosine kinase inhibitor, markedly augments cytotoxicity of chemotherapies in human gastric cancer. ABT-869 and chemotherapeutic agents exhibited a strong synergy to inhibit the viability of several gastric cancer cell lines, with combination index values ranging from 0.017 to 0.589. Additionally, the combination of ABT-869 and chemotherapeutic agents led to remarkable suppression of vascular endothelial growth factor (VEGF)-induced angiogenesis in vitro and in vivo. Importantly, in a preclinical gastric cancer xenograft mouse model, drug co-treatments led to increased mouse survival as well as a synergistic reduction in tumor size and the inhibition of tumor angiogenesis. Mechanistic studies further revealed that all of the co-treatments containing ABT-869 resulted in decreased activation of the VEGF receptor, the epidermal growth factor receptor and the insulin growth factor receptor. Inhibition of these receptor tyrosine kinases consequently attenuated the activation of the downstream AKT/mTOR signaling pathway both in cultured gastric cancer cells and in gastric cancer xenografts. Collectively, our findings suggest that the addition of ABT-869 to traditional chemotherapies may be a promising strategy for the treatment of human gastric cancer

    Suppression of KRas-mutant cancer through the combined inhibition of KRAS with PLK1 and ROCK

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    No effective targeted therapies exist for cancers with somatic KRAS mutations. Here we develop a synthetic lethal chemical screen in isogenic KRAS-mutant and wild-type cells to identify clinical drug pairs. Our results show that dual inhibition of polo-like kinase 1 and RhoA/Rho kinase (ROCK) leads to the synergistic effects in KRAS-mutant cancers. Microarray analysis reveals that this combinatory inhibition significantly increases transcription and activity of cyclin-dependent kinase inhibitor p21(WAF1/CIP1), leading to specific G2/M phase blockade in KRAS-mutant cells. Overexpression of p21(WAF1/CIP1), either by cDNA transfection or clinical drugs, preferentially impairs the growth of KRAS-mutant cells, suggesting a druggable synthetic lethal interaction between KRAS and p21(WAF1/CIP1). Co-administration of BI-2536 and fasudil either in the LSL-KRAS(G12D) mouse model or in a patient tumour explant mouse model of KRAS-mutant lung cancer suppresses tumour growth and significantly prolongs mouse survival, suggesting a strong synergy in vivo and a potential avenue for therapeutic treatment of KRAS-mutant cancers

    New Ceratocystis species from Eucalyptus and Cunninghamia in South China

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    During routine surveys for possible fungal pathogens in the rapidly expanding plantations of Eucalyptus and Cunninghamia lanceolata in China, numerous isolates of unknown species in the genus Ceratocystis (Microascales) were obtained from tree wounds. In this study we identified the Ceratocystis isolates from Eucalyptus and Cunninghamia in the GuangDong, GuangXi, FuJian and HaiNan Provinces of South China based on morphology and through comparisons of DNA sequence data for the ITS, partial Ī²-tubulin and TEF-1Ī± gene regions. Morphological and DNA sequence comparisons revealed two previously unknown species residing in the Indo-Pacific Clade. These are described here as C. cercfabiensis sp. nov. and C. collisensis sp. nov. Isolates of C. cercfabiensis showed intragenomic variation in their ITS sequences and four strains were selected for cloning of the ITS gene region. Twelve ITS haplotypes were obtained from 17 clones selected for sequencing,differing in up to seven base positions and representing two separate phylogenetic groups. This is the first evidence of multiple ITS types in isolates of Ceratocystis residing in the Indo-Pacific Clade. Caution should thus be exercised when using the ITS gene region as a barcoding marker for Ceratocystis species in this clade. This study also represents the first record of a species of Ceratocystis from Cunninghamia.This study was initiated through the bilateral agreement between the Governments South Africa and China, and we are grateful for the funding via projects 2012DFG31830 (International Science & Technology Cooperation Program of China), 31400546 (National Natural Science Foundation of China: NSFC),2010KJCX015-03 (Forestry Science and Technology Innovation Project of Guangdong Province of China). The Tree Protection and Cooperation Programme (TPCP) and the National ResearchFoundation (NRF), South Africa.http://link.springer.com/journal/104822016-06-30hb201

    Calonectria species isolated from Eucalyptus plantations and nurseries in South China

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    Diseases caused by species of Calonectria (Ca.) represent a serious threat to the growth and sustainability of Eucalyptus plantations in China. Symptoms caused by these fungi mainly include leaf blight on trees in plantations and rotting of stems and leaves in nurseries. Extensive surveys have recently been conducted where Calonectria species were collected in Eucalyptus plantations and nurseries in the FuJian, GuangDong, GuangXi, and YunNan Provinces of South China. Additional isolates were baited from soil samples in the Hong Kong Region. The aim of this study was to identify the 115 Calonectria isolates obtained using comparisons of DNA sequence data for the Ī²-tubulin (tub2), calmodulin (cmdA), histone H3 (his3) and partial translation elongation factor-1Ī± (tef1) gene regions as well as their morphological features. Seven known species were identified, including Calonectria arbusta, Ca. asiatica, Ca. chinensis, Ca. eucalypti, Ca. hongkongensis, Ca. mossambicensis and Ca. pentaseptata. In addition, six novel taxa were collected and are described here as Ca. aciculata, Ca. honghensis, Ca. lantauensis, Ca. pseudoturangicola, Ca. pseudoyunnanensis, and Ca. yunnanensis spp. nov. Overall, the results reflect a high diversity of Calonectria species in China.The National Natural Science Foundation of China (NSFC) (Project Numbers 31622019, 31400546).http://www.imafungus.orgam2018Forestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc

    Reconsideration of species boundaries and proposed DNA barcodes for Calonectria

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    Calonectria represents a genus of phytopathogenic ascomycetous fungi with a worldwide distribution. In recent years, there has been an increase in the number of taxonomic studies on these fungi. Currently, there are 169 described species of Calonectria based on comparisons of DNA sequence data, combined with morphological characteristics. However, for some of these species, the sequence data utilised at the time of their description were relatively limited. This has justified an urgent need to reconsider the species boundaries for Calonectria based on robust genus-wide phylogenetic analyses. In this study, we utilised 240 available isolates including the ex-types of 128 Calonectria species, and re-sequenced eight gene regions (act, cmdA, his3, ITS, LSU, rpb2, tef1 and tub2) for them. Sequences for 44 Calonectria species, for which cultures could not be obtained, were downloaded from GenBank. DNA sequence data of all the 169 Calonectria species were then used to determine their phylogenetic relationships. As a consequence, 51 species were reduced to synonymy, two new species were identified, and the name Ca. lauri was validated. This resulted in the acceptance of 120 clearly defined Calonectria spp. The overall data revealed that the genus includes 11 species complexes, distributed across the Prolate and Sphaero-Naviculate Groups known to divide Calonectria. The results also made it possible to develop a robust set of DNA barcodes for Calonectria spp. To accomplish this goal, we evaluated the outcomes of each of the eight candidate DNA barcodes for the genus, as well as for each of the 11 species complexes. No single gene region provided a clear identity for all Calonectria species. Sequences of the tef1 and tub2 genes were the most reliable markers; those for the cmdA, his3, rpb2 and act gene regions also provided a relatively effective resolution for Calonectria spp., while the ITS and LSU failed to produce useful barcodes for species discrimination. At the species complex level, results showed that the most informative barcodes were inconsistent, but that a combination of six candidate barcodes (tef1, tub2, cmdA, his3, rpb2 and act) provided stable and reliable resolution for all 11 species complexes. A six-gene combined phylogeny resolved all 120 Calonectria species, and revealed that tef1, tub2, cmdA, his3, rpb2 and act gene regions are effective DNA barcodes for Calonectria.http://www.studiesinmycology.orgam2021BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

    Expression of MK-1 and Regā…£ and its clinicopathological significances in the benign and malignant lesions of gallbladder

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    <p>Abstract</p> <p>Background</p> <p>To study the expression of MK-1 and Regā…£ and to detect their pathological significances in benign and malignant lesions of gallbladder.</p> <p>Methods</p> <p>The expression of MK-1 and Regā…£ was detected by immunohistochemical method in paraffin-embedded sections of surgical resected specimens from gallbladder adenocarcinoma (n = 108), peritumoral tissues (n = 46), adenomatous polyp (n = 15), and chronic cholecystitis (n = 35).</p> <p>Results</p> <p>The positive rate of MK-1 or Regā…£ expression was significantly higher in gallbladder adenocarcinoma than that in peritumoral tissues (Ļ‡<sup>2</sup><sub>MK-1 </sub>= 18.76, <it>P </it>< 0.01; Ļ‡<sup>2</sup><sub>Regā…£ </sub>= 9.92, <it>P </it>< 0.01), denomatous polyp (Ļ‡<sup>2</sup><sub>MK-1 </sub>= 9.49, <it>P </it>< 0.01; Ļ‡<sup>2</sup><sub>Regā…£ </sub>= 8.59, <it>P </it>< 0.01) and chronic cholecystitis (Ļ‡<sup>2</sup><sub>MK-1 </sub>= 24.11, <it>P </it>< 0.01; Ļ‡<sup>2</sup><sub>Regā…£ </sub>= 19.24, <it>P </it>< 0.01). The positive cases of MK-1 and/or Regā…£ in the benign lesions showed moderately- or severe-atypical hyperplasia of gallbladder epitheli. The positive rates of MK-1 were significantly higher in the cases of well-differentiated adenocarcinoma, no-metastasis of lymph node, and no-invasiveness of regional tissues than those in the ones of differentiated adenocarcinoma, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma (<it>P </it>< 0.05 or <it>P </it>< 0.01). On the contrary, the positive rates of Regā…£ were significantly lower in the cases of well-differentiated adenocarcinoma, no-metastasis of lymph node, and no-invasiveness of regional tissues than those in the ones of differentiated adenocarcinoma, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma (<it>P </it>< 0.05 or <it>P </it>< 0.01). Univariate Kaplan-Meier analysis showed that decreased expression of MK-1 (<it>P </it>= 0.09) or increased expression of Regā…£ (<it>P </it>= 0.003) was associated with decreased overall survival. Multivariate Cox regression analysis showed that decreased expression of MK-1 (<it>P </it>= 0.033) and increased expression of Regā…£ (<it>P </it>= 0.008) was an independent prognostic predictor in gallbladder adenocarcinoma.</p> <p>Conclusions</p> <p>The expression of MK-1 and/or Regā…£ might be closely related to the carcinogenesis, clinical biological behaviors, and prognosis of gallbladder adenocarcinoma.</p

    Design and Research of Electron Cyclotron Resonance Heating and Current Dive System on HL-2M Tokamak

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    A research has been conducted to develop an 8MW electron cyclotron resonance heating and current drive (ECRH/ECCD) system on HL-2M tokamak. The ECRH system compromise eight 1MW gyrotrons, eight evacuated transmission lines and three launchers. The main purpose of the ECRH system was to suppress the neo-classical tearing modes and control the plasma profile. This paper presents an overview of the design and studies performed in this framework. Some primary test results of the critical components have been released in this paper, e.g. polarizers, power monitor and fast steering launchers
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