80 research outputs found
Regio- and Stereoselective Ruthenium Catalyzed Hydrovinylation of 1,3-Dienes: Application to the Generation of a 20S-Steroidal Sidechain
The addition of ethylene to 1,3-dienes and 1-vinylcycloalkenes, catalyzed by two ruthenium complexes, proceeds in a regioselective fashion to afford 3-methyl-1,4-dienes as products. For a steroidal-based 1-vinylcycloalkene, the addition is stereospecific, giving a product with a 20(S) configuration
Probing the Human Estrogen Receptor-Ī± Binding Requirements for Phenolic Mono- and Di-Hydroxyl Compounds: A Combined Synthesis, Binding and Docking Study
Various estrogen analogs were synthesized and tested for binding to human ERĪ± using a fluorescence polarization displacement assay. Binding affinity and orientation were also predicted using docking calculations. Docking was able to accurately predict relative binding affinity and orientation for estradiol, but only if a tightly bound water molecule bridging Arg394/Glu353 is present. Di-hydroxyl compounds sometimes bind in two orientations, which are flipped in terms of relative positioning of their hydroxyl groups. Di-hydroxyl compounds were predicted to bind with their aliphatic hydroxyl group interacting with His524 in ERĪ±. One nonsteroid-based dihdroxyl compound was 1000-fold specific for ERĪ² over ERĪ±, and was also 25-fold specific for agonist ERĪ² versus antagonist activity. Docking predictions suggest this specificity may be due to interaction of the aliphatic hydroxyl with His475 in the agonist form of ERĪ², versus with Thr299 in the antagonist form. But, the presence of this aliphatic hydroxyl is not required in all compounds, since mono-hydroxyl (phenolic) compounds bind ERĪ± with high affinity, via hydroxyl hydrogen bonding interactions with the ERĪ± Arg394/Glu353/water triad, and van der Waals interactions with the rest of the molecule
Who is Gambling? Finding Cryptocurrency Gamblers Using Multi-modal Retrieval Methods
With the popularity of cryptocurrencies and the remarkable development of
blockchain technology, decentralized applications emerged as a revolutionary
force for the Internet. Meanwhile, decentralized applications have also
attracted intense attention from the online gambling community, with more and
more decentralized gambling platforms created through the help of smart
contracts. Compared with conventional gambling platforms, decentralized
gambling have transparent rules and a low participation threshold, attracting a
substantial number of gamblers. In order to discover gambling behaviors and
identify the contracts and addresses involved in gambling, we propose a tool
termed ETHGamDet. The tool is able to automatically detect the smart contracts
and addresses involved in gambling by scrutinizing the smart contract code and
address transaction records. Interestingly, we present a novel LightGBM model
with memory components, which possesses the ability to learn from its own
misclassifications. As a side contribution, we construct and release a
large-scale gambling dataset at
https://github.com/AwesomeHuang/Bitcoin-Gambling-Dataset to facilitate future
research in this field. Empirically, ETHGamDet achieves a F1-score of 0.72 and
0.89 in address classification and contract classification respectively, and
offers novel and interesting insights
Spectral Data for Probing the human estrogen receptor-alpha binding requirements for phenolic mono- and do-hydroxyl compounds: A combined synthesis, binding and docking study
Spectral data used in the course of researching Probing the human estrogen receptor-alpha binding requirements for phenolic mono- and do-hydroxyl compounds: A combined synthesis, binding and docking study .
Various estrogen analogs were synthesized and tested for binding to human ERĪ± using a fluorescence polarization displacement assay. Binding affinity and orientation were also predicted using docking calculations. Docking was able to accurately predict relative binding affinity and orientation for estradiol, but only if a tightly bound water molecule bridging Arg394/Glu353 is present. Di-hydroxyl compounds sometimes bind in two orientations, which are flipped in terms of relative positioning of their hydroxyl groups. Di-hydroxyl compounds were predicted to bind with their aliphatic hydroxyl group interacting with His524 in ERĪ±. One nonsteroid-based dihdroxyl compound was 1000-fold specific for ERĪ² over ERĪ±, and was also 25-fold specific for agonist ERĪ² versus antagonist activity. Docking predictions suggest this specificity may be due to interaction of the aliphatic hydroxyl with His475 in the agonist form of ERĪ², versus with Thr299 in the antagonist form. But, the presence of this aliphatic hydroxyl is not required in all compounds, since mono-hydroxyl (phenolic) compounds bind ERĪ± with high affinity, via hydroxyl hydrogen bonding interactions with the ERĪ± Arg394/Glu353/water triad, and van der Waals interactions with the rest of the molecule
Probing the Human Estrogen Receptor-Alpha Binding Requirements for Phenolic Mono- and di-Hydroxyl compounds: A Combined Synthesis, Binding and Docking Study
Various estrogen analogs were synthesized and tested for binding to human ERĪ± using a fluorescence polarization displacement assay. Binding affinity and orientation were also predicted using docking calculations. Docking was able to accurately predict relative binding affinity and orientation for estradiol, but only if a tightly bound water molecule bridging Arg394/Glu353 is present. Di-hydroxyl compounds sometimes bind in two orientations, which are flipped in terms of relative positioning of their hydroxyl groups. Di-hydroxyl compounds were predicted to bind with their aliphatic hydroxyl group interacting with His524 in ERĪ±. One nonsteroid-based dihdroxyl compound was 1000-fold specific for ERĪ² over ERĪ±, and was also 25-fold specific for agonist ERĪ² versus antagonist activity. Docking predictions suggest this specificity may be due to interaction of the aliphatic hydroxyl with His475 in the agonist form of ERĪ², versus with Thr299 in the antagonist form. But, the presence of this aliphatic hydroxyl is not required in all compounds, since mono-hydroxyl (phenolic) compounds bind ERĪ± with high affinity, via hydroxyl hydrogen bonding interactions with the ERĪ± Arg394/Glu353/water triad, and van der Waals interactions with the rest of the molecule
The paleoclimatic footprint in the soil carbon stock of the Tibetan permafrost region
Data and code availability The authors declare that the majority of the data supporting the findings of this study are available through the links given in the paper. The unpublished data are available from the corresponding author upon request. The new estimate of Tibetan soil carbon stock and R code are available in a persistent repository (https://figshare.com/s/4374f28d880f366eff6d). Acknowledgements This study was supported by the Strategic Priority Research Program (A) of the Chinese Academy of Sciences (XDA20050101), the National Natural Science Foundation of China (41871104), Key Research and Development Programs for Global Change and Adaptation (2017YFA0603604), International Partnership Program of the Chinese Academy of Sciences (131C11KYSB20160061) and the Thousand Youth Talents Plan project in China. Jinzhi Ding acknowledges the General (2017M620922) and the Special Grade (2018T110144) of the Financial Grant from the China Postdoctoral Science Foundation.Peer reviewedPublisher PD
A male sterility-associated cytotoxic protein ORF288 in Brassica juncea causes aborted pollen development
Cytoplasmic male sterility (CMS) is a widespread phenomenon in higher plants, and several studies have established that this maternally inherited defect is often associated with a mitochondrial mutant. Approximately 10 chimeric genes have been identified as being associated with corresponding CMS systems in the family Brassicaceae, but there is little direct evidence that these genes cause male sterility. In this study, a novel chimeric gene (named orf288) was found to be located downstream of the atp6 gene and co-transcribed with this gene in the hau CMS sterile line. Western blotting analysis showed that this predicted open reading frame (ORF) was translated in the mitochondria of male-sterile plants. Furthermore, the growth of Escherichia coli was significantly repressed in the presence of ORF288, which indicated that this protein is toxic to the E. coli host cells. To confirm further the function of orf288 in male sterility, the gene was fused to a mitochondrial-targeting pre-sequence under the control of the Arabidopsis APETALA3 promoter and introduced into Arabidopsis thaliana. Almost 80% of transgenic plants with orf288 failed to develop anthers. It was also found that the independent expression of orf288 caused male sterility in transgenic plants, even without the transit pre-sequence. Furthermore, transient expression of orf288 and green fluorescent protein (GFP) as a fused protein in A. thaliana protoplasts showed that ORF288 was able to anchor to mitochondria even without the external mitochondrial-targeting peptide. These observations provide important evidence that orf288 is responsible for the male sterility of hau CMS in Brassica juncea
Fast Decision Algorithm of CU Size for HEVC Intra-Prediction Based on a Kernel Fuzzy SVM Classifier
High Efficiency Video Coding (HEVC) achieves a significant improvement in compression efficiency at the cost of extremely high computational complexity. Therefore, large-scale and wide deployment applications, especially mobile real-time video applications under low-latency and power-constrained conditions, are more challenging. In order to solve the above problems, a fast decision method for intra-coding unit size based on a new fuzzy support vector machine classifier is proposed in this paper. The relationship between the depth levels of coding units is accurately expressed by defining the cost evaluation criteria of texture and non-texture rate-distortion cost. The fuzzy support vector machine is improved by using the information entropy measure to solve the negative impact of data noise and the outliers problem. The proposed method includes three stages: the optimal coded depth level ā0ā early decision, coding unit depth early skip, and optimal coding unit early terminate. In order to further improve the rate-distortion complexity optimization performance, more feature vectors are introduced, including features such as space complexity, the relationship between coding unit depths, and rate-distortion cost. The experimental results showed that, compared with the HEVC reference test model HM16.5, the proposed algorithm can reduce the encoding time of various test video sequences by more than 53.24% on average, while the Bjontegaard Delta Bit Rate (BDBR) only increases by 0.82%. In addition, the proposed algorithm is better than the existing algorithms in terms of comprehensively reducing the computational complexity and maintaining the rate-distortion performance
Ruthenium-Catalyzed Hydrovinylation of Dienoates: Model Studies Directed Toward the C10āC18 Segment of Ambruticin
The ruthenium-catalyzed hydrovinylation of 2,4-dienoates 3 proceeds in a regioselective fashion to give 4-alkyl-2,5-dienoates 4 in good yields. Olefin cross-metathesis of a vinylcyclopropane with 4e demonstrates a synthetic route to the C10-C18 Āsegment of ambruticin
Convergent Synthesis of Polysubstituted Furans via Catalytic Phosphine Mediated Multicomponent Reactions
Tri- or tetrasubstituted furans have been prepared from terminal activated olefins and acyl chlorides or anhydrides by a multicomponental convergent synthesis mode. Instead of stoichiometric nBu3P, only catalytic nBu3P or nBu3P=O is needed to furnish the furans in modest to excellent yields with a good functional group tolerance under the aid of reducing agent silane. This synthetic method features a silane-driven catalytic intramolecular Wittig reaction as a key annulation step and represents the first successful application of catalytic Wittig reaction in multicomponent cascade reaction
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