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A combinatorial synthesis method for identification of orally bioavailable cyclic peptide

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Science China Chemistry 2024年第8期67卷 2429-2430页

作者： zhenzhen liu Li liu Bo Tang College of Chemistry Chemical Engineering and Materials ScienceKey Laboratory of Molecular and Nano ProbesMinistry of EducationCollaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of ShandongInstitutes of Biomedical SciencesShandong Normal UniversityJinan 250014China Laoshan Laboratory Qingdao 266237China

Cyclic peptides are a type of polypeptide with macrocyclic structure formed by canonical and non-canonical amino *** to their rigid conformation and large surface area,cyclic peptides typically exhibit high binding affinity and specificity with target proteins,particularly those considered undruggable by traditional small molecule drugs,such as protein-protein interactions[1].Additionally,they are convenient to be chemical modified to improve the pharmacological or pharmacokinetic properties.

关键词： properties. canonical synthesis

Fluorescence triggered by ligand-protein hydrophobic interaction

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Science China Chemistry 2013年第11期56卷 1667-1670页

作者： liu zhenzhen DU LuPei LI MinYong Department of Medicinal Chemistry School of PharmacyShandong University

Hydrophobic fluorescence:Tan and his colleagues recently introduced a brand new chemotype of environment-sensitive fluorescent turn-on probes to detect the hydrophobic ligand-binding domain by using SBD *** design strategy described in this report generalized the environment sensitivity turn-on mechanism to recognize a specific protein,which provides a robust breakthrough for interchanging fluorescence in conventional small-molecule fluorescent imaging.

关键词： non-enzyme protein environment-sensitive probe turn-on fluorescence SBD fluorophore

Convergence analysis and performance optimization of parallel concatenated systematic polar code

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The Journal of China Universities of Posts and Telecommunications 2018年第2期25卷 1-9页

作者： liu zhenzhen Niu Kai Dong Chao Lin Jiaru School of Information and Communication Engineering Beijing University of Posts and Telecommunications

Similar to the analysis of Turbo codes, the parallel concatenated systematic polar code （PCSPC） can also be analyzed by the extrinsic information transfer （EXIT） chart. The convergence of the iterative decoding based on soft cancellation （SCAN） and belief propagation （BP） of PCSPC are analyzed by the EXIT chart. Analysis shows that SCAN decoder is more appropriate than BP decoder for this iterative decoding structure in terms of complexity. In addition, the weight coefficients of the iterative decoding structure are optimized by the simulated-EXIT （S- EXIT） chart, which improves the performance of PCSPC.

关键词： PCSPC EXIT chart SCAN decoder BP decoder weight coefficient

Evaluation of a deep-learning model for multispectral remote sensing of land use and crop classification

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The Crop Journal 2022年第5期10卷 1435-1451页

作者： Lijun Wang Jiayao Wang zhenzhen liu Jun Zhu Fen Qin Henan Industrial Technology Academy of Spatio-Temporal Big Data Henan UniversityKaifeng 475004HenanChina College of Geography and Environmental Science Henan UniversityKaifeng 475004HenanChina Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Ministry of EducationHenan UniversityKaifeng 475004HenanChina Key Research Institute of Yellow River Civilization and Sustainable Development Ministry of EducationHenan UniversityKaifeng 475004HenanChina Henan Technology Innovation Center of Spatial-Temporal Big Data Henan UniversityKaifeng 475004HenanChina

High-resolution deep-learning-based remote-sensing imagery analysis has been widely used in land-use and crop-classification mapping. However, the influence of composite feature bands, including complex feature indices arising from different sensors on the backbone, patch size, and predictions in transferable deep models require further testing. The experiments were conducted in six sites in Henan province from2019 to 2021. This study sought to enable the transfer of classification models across regions and years for Sentinel-2 A(10-m resolution) and Gaofen PMS(2-m resolution) imagery. With feature selection and up-sampling of small samples, the performance of UNet++ architecture on five backbones and four patch sizes was examined. Joint loss, mean Intersection over Union(m Io U), and epoch time were analyzed, and the optimal backbone and patch size for both sensors were Timm-Reg Net Y-320 and 256 × 256, respectively. The overall accuracy and Fscores of the Sentinel-2 A predictions ranged from 96.86% to 97.72%and 71.29% to 80.75%, respectively, compared to 75.34%–97.72% and 54.89%–73.25% for the Gaofen predictions. The accuracies of each site indicated that patch size exerted a greater influence on model performance than the backbone. The feature-selection-based predictions with UNet++ architecture and upsampling of minor classes demonstrated the capabilities of deep-learning generalization for classifying complex ground objects, offering improved performance compared to the UNet, Deeplab V3+, Random Forest, and Object-Oriented Classification models. In addition to the overall accuracy, confusion matrices,precision, recall, and F1 scores should be evaluated for minor land-cover types. This study contributes to large-scale, dynamic, and near-real-time land-use and crop mapping by integrating deep learning and multi-source remote-sensing imagery.

关键词： Land use and crop classification Deep learning High-resolution image Feature selection UNet++

An RDF Data Set Quality Assessment Mechanism for Decentralized Systems

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Data Intelligence 2020年第4期2卷 529-553页

作者： Li Huang zhenzhen liu Fangfang Xu Jinguang Gu Hubei Province Key Laboratory of Intelligent Information Processing and Real-time Industrial System Wuhan University of Science and TechnologyWuhan 430065China College of Computer Science and Technology Wuhan University of Science and TechnologyWuhan 430065China Key Laboratory of Rich-media Knowledge Organization and Service of Digital Publishing Content State Administration of Radio and TelevisionBeijing 100038China

With the rapid growth of the linked data on the Web,the quality assessment of the RDF data set becomes particularly important,especially for the quality and accessibility of the linked *** most cases,RDF data sets are shared online,leading to a high maintenance cost for the quality *** also potentially pollutes Internet *** blockchain technology has shown the potential in many *** the blockchain storage quality assessment results can reduce the centralization of the authority,and the quality assessment results have characteristics such as *** this end,we propose an RDF data quality assessment model in a decentralized environment,pointing out a new dimension of RDF data *** use the blockchain to record the data quality assessment results and design a detailed update strategy for the quality assessment *** have implemented a system DCQA to test and verify the feasibility of the quality assessment *** proposed method can provide users with better cost-effective results when knowledge is independently protected.

关键词： Decentralization Quality assessment Blockchain RDF data set

Discovery of nitric oxide in marine ecological system and the chemical characteristics of nitric oxide

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Science China Chemistry 2006年第5期49卷 475-480页

作者： ZHANG Zhengbin XING Lei WU zhenzhen liu Chunying LIN Cai liu Liansheng Institute of Marine Chemistry Ocean University of China Qingdao 266003 China Institute of Marine Chemistry Ocean University of China Qingdao 266003 China Institute of Marine Chemistry Ocean University of China Qingdao 266003 China Institute of Marine Chemistry Ocean University of China Qingdao 266003 China Institute of Marine Chemistry Ocean University of China Qingdao 266003 China Institute of Marine Chemistry Ocean University of China Qingdao 266003 China

Nitric oxide was discovered in both the lab and the alga culture pond of Daya Bay (1―300 m3) before the growth of alga reached the maximum. The results included: (1) NO was detected before the growth of alga reached the maximum in the case of red tide alga and food alga, and the concentration of NO decreased rapidly after the growth maximum; (2) the curve between NO con-centration and time indicated that the concentration of NO in the daytime was more than that at night, and the maximal concentration of NO appeared in the midday (1―3 pm); (3) the growth of alga reached the maximum in the alga culture pond of Daya Bay in about 8―10 d, and NO was discovered in 5―7 d; (4) the measured NO concentration was 10-9 mol/L, 10-9―10-8 mol/L, and 10-8 mol/L for Haeterosigma akashiwo, mixed alga in Daya Bay and Chaetoceros Curvisetus individually; (5) the relation of illumination with NO production was discussed.

关键词： marine ecological system, the detection of nitric oxide, red tide alga, the chemical characteristics of nitric oxide production.

Investigating Transport Properties of Environmentally Friendly Azeotropic Binary Blends Based on Evaporation in Auto-Cascade Refrigeration

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Frontiers in Heat and Mass Transfer 2024年第4期22卷 1087-1105页

作者： zhenzhen liu Hua Zhang Zilong Wang Yugang Zhao Institute of Refrigeration and Cryogenics Engineering School of Energy and Power EngineeringUniversity of Shanghai for Science and TechnologyShanghai200093China

The exploration of performance and prediction of environmentally friendly refrigerant physical properties represents a critical *** dynamics simulationswere employed to investigate the density and transport properties of propane and ethane at ultra-low temperatures under evaporative pressure *** results of the density simulation of the evaporation conditions of the blends proved the validity of the simulation *** identical temperature and pressure conditions,increasing the proportion of R170 in the refrigerant blends leads to a density decrease while the temperature range in which the gas-liquid phase transition occurs is *** analysis of simulated results pertaining to viscosity,thermal conductivity,and self-diffusion coefficient reveals heightened deviation levels within the phase transition temperature *** increase in deviation attributed to intensified molecular *** terms of uncovering the physical mechanism of gas-liquid phase transition,the work illustrates the macroscopic phenomenon of the intensified existing disorder during phase transitions at the molecular *** dynamics simulations analyzing the thermophysical properties of refrigerant blends from a microscopic point of view can deepen the comprehension of the thermal optimization of refrigeration processes.

关键词： Molecular dynamics simulation hydrocarbon binary blends transport properties evaporation

Scaling Factor Optimization of Turbo-Polar Iterative Decoding

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China Communications 2018年第6期15卷 169-177页

作者： zhenzhen liu Kai Niu Jiaru Lin Jingyuan Sun Hao Guan Beijing University of Posts and Telecommunications Beijing 100876China Nokia Shanghai Bell Co. Ltd.Beijing 100876China

In this paper, we investigate the weighted iterative decoding to improve the performance of turbo-polar code. First of all, a minimum weighted mean square error criterion is proposed to optimize the scaling factors(SFs). Secondly, for two typical iterative algorithms,such as soft cancellation(SCAN) and belief propagation(BP) decoding, genie-aided decoders are proposed as the ideal reference of the practical decoding. Guided by this optimization framework, the optimal SFs of SCAN or BP decoders are obtained. The bit error rate performance of turbo-polar code with the optimal SFs can achieve 0.3 dB or 0.7 dB performance gains over the standard SCAN or BP decoding respectively.

关键词： turbo-polar code BP decoder SCAN decoder mean square error scaling factors

Visualization of endoplasmic reticulum viscosity in the liver of mice with nonalcoholic fatty liver disease by a near-infrared fluorescence probe

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Chinese Chemical Letters 2021年第11期32卷 3641-3645页

作者： Yongqing Zhou zhenzhen liu Guangming Qiao Bo Tang Ping Li College of Chemistry Chemical Engineering and Materials ScienceKey Laboratory of Molecular and Nano ProbesMinistry of EducacionInstitutes of Biomedical SciencesShandong Normal UniversityJinan 250014China Environment Pollution Control Center Zibo 255000China

Nonalcoholic fatty liver disease(NAFLD)can cause serious liver *** diagnosis and effective treatment of NAFLD can greatly improve treatment *** initiation and development of NAFLD has been closely linked to endoplasmic reticulum(ER)stress,which might cause ER viscosity ***,if the internal relationship between ER viscosity and NAFLD is clarified,an effective approach for early diagnosis may ***,we fabricated a novel near-infrared(NIR)fluorescence imaging probe,Er-V,for monitoring ER viscosity through a molecular rotor ***-V exhibited a strong NIR fluorescence signal(at 626 nm)when the environmental viscosity hindered the rotation of the malononitrile *** Er-V,we successfully observed a significant enhancement in viscosity in the liver of mice with ***,this imaging method based on Er-V is expected to provide a new approach for early detection and diagnosis of NAFLD.

关键词： Nonalcoholic fatty liver disease Endoplasmic reticulum stress Viscosity Fluorescence imaging probe