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基于分子动力学模拟与实验验证探讨黄芩素抑制PD-1/PD-L1相互作用的分子机制

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食品工业科技 2024年第2期45卷 40-47页

作者：郭妍郭怡琳刘柏平徐建国山西师范大学食品科学学院山西太原030031 华南农业大学材料与能源学院广东广州510630 华南农业大学教育部生物材料与能源重点实验室广东广州510630

为研究黄芩素阻断程序性细胞死亡-1/程序性细胞死亡配体1(PD-1/PD-L1)通路的分子机制,本文首先采用分子对接、分子动力学模拟、结合自由能计算和主成分分析等方法预测了黄芩素的抑制作用,然后利用酶联免疫吸附试验(ELISA)进行了实验验... 详细信息

为研究黄芩素阻断程序性细胞死亡-1/程序性细胞死亡配体1(PD-1/PD-L1)通路的分子机制,本文首先采用分子对接、分子动力学模拟、结合自由能计算和主成分分析等方法预测了黄芩素的抑制作用,然后利用酶联免疫吸附试验(ELISA)进行了实验验证。结合自由能结果表明,黄芩素与PD-L1二聚体(PD-L1 dimer)的结合亲和力为-32.41±0.31 kcal/mol。结合能分解、接触数和非键相互作用结果显示,黄芩素主要结合在PD-L1 dimer的C-、C’-、F-和G-sheet区域,其中关键残基Tyr56、Met115、Ala121和Asp122与黄芩素之间的非极性相互作用在结合过程中起主导作用。互相关矩阵和二级结构结果进一步表明,黄芩素可与PD-L1 dimer的sheet区域稳定结合。ELISA结果显示黄芩素对PD-1/PD-L1相互作用抑制率的IC_(50)为79.47μg/L。黄芩素可通过直接与PD-L1dimer结合抑制PD-1/PD-L1相互作用,本研究为该通路天然小分子抑制剂的发现提供了依据。

关键词：程序性细胞死亡-1/程序性细胞死亡配体1 天然小分子黄芩素分子动力学模拟抑制机制

Preparation of Mesoporous Nano-Hydroxyapatite Using a Surfactant Template Method for Protein Delivery

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Journal of Bionic Engineering 2012年第2期9卷 224-233页

作者： Xiaodong Wu Xiaofeng Song Dongsong Li Jianguo Liu Peibiao Zhang Xuesi Chen Department of Bone and Joint Surgery First Hospital of Jilin UniversityChangchun 130021P R.China Key Laboratory of Polymer Ecobiomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangehun 130022P.R.China

Mesoporous nano-hydroxyapatite （n-HA） has gained more and more attention as drug storage and release hosts. The aim of this study is to observe the effect of the ratio of surfactant to the theoretical yield of HA on the mesoporous n-HA, then to reveal the effect of the mesoporous nanostructure on protein delivery. The mesoporous n-HA was synthesized using the wet precipitation in the presence of cetyltrimethylammonium bromide （CTAB） at ambient temperature and normal atmospheric pressure. The morphology, size, crystalline phase, chemical composition and textural characteristics of the product were well characterized by X-ray Powder Diffraction （XRD）, Fourier Transform Infrared Spectroscopy （FTIR）, Scanning Electron Microscopy （SEM）, Transmission Electron Microscopy （TEM）, Dynamic Light Scattering （DLS） and N2 adsorption/desorption, respectively. The protein adsorption/release studies were also carried out by using Bovine Serum Albumin （BSA） as a model protein. The results reveal that the mesoporous n-HA synthesized with CTAB exhibits high pure phase, low crystallinity and the typical characteristics of the mesostructure. The BSA loading increases with the specific surface area and the pore volume of n-HA, and the release rates of BSA are different due to their different pore sizes and pore structures, n-HA synthesized with 0.5% CTAB has the highest BSA loading and the slowest release rate because of its highest surface area and smaller pore size. These mesoporous n-HA materials demonstrate a potential application in the field of protein delivery due to their bioactive, biocompatible and mesoporous properties.

关键词： hydroxyapatite nanoparticles mesostructure cetyltrimethylammonium bromide drug delivery

Effects of temperature on pyrolysis products of oil sludge

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Frontiers of Environmental Science & Engineering 2008年第1期2卷 8-14页

作者： Jianguo Liu Wei SONG Yongfeng NIE Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China

Temperature is the determining factor of pyro-lysis,which is one of the alternative technologies for oil sludge treatment.The effects of final operating temper-ature ranging from 350 to 550uC on pyrolysis products of oil sludge were studied in an externally-heating fixed bed reactor.With an increase of temperature,the mass fraction of solid residues,liquids,and gases in the final product is 67.00%–56.00%,25.60%–32.35%,and 7.40%–11.65%,and their corresponding heat values are 34.4–13.8 MJ/kg,44.41–46.6 MJ/kg,and 23.94–48.23 MJ/Nm 3,respectively.The mass and energy tend to shift from solid to liquid and gas phase(especially to liquid phase)during the process,and the optimum temperature for oil sludge pyrolysis is 500uC.The liquid phase is mainly com-posed of alkane and alkene(C_(5)–C_(29)),and the gas phase is dominantly HC S and H 2.

关键词： oil sludge pyrolysis temperature fixed bed reactor pyrolysis products

Visualization of force networks in 2D dense granular materials

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Frontiers of Structural and Civil Engineering 2010年第1期4卷 109-115页

作者： Jianguo Liu Qicheng SUN Feng JIN State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijing 100084China

Dense granular matter is a conglomeration of discrete solid and closely packed particles.As subjected to external loadings,the stress is largely transmitted by heavily stressed chains of particles forming a sparse network of larger contact forces.To understand the structure and evolution of force chains,a photoelastic technique was improved for determining stresses and strains in the assemblies of photoelastic granular disks in this paper.A two-dimensional vertical slab was designed.It contains 7200 polydispersed photoelastic disks and is subjected to a localized probe penetrating at the top of the slab to mimic the cone penetration test.The interparticle contact force distribution was found a peak around the mean value,a roughly exponential tail for greater force and a dip toward zero for smaller force.The force chain network around the probe tip was depicted,and the contact angle distribution of particles in force chains was found to be well aligned in the directions of major principal stress.

关键词： granular matter force chain multiscale modeling

Diagnostic Method and Adaptability Analysis of Multiple Water Breakthroughs in Horizontal Well in Combined Well Pattern

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Journal of Geoscience and Environment Protection 2023年第5期11卷 150-158页

作者： Zheng Lv Meinan Wang Guohao Zhang Rui Zhang Jianguo Liu Bohai Oilfield Research Institute of CNOOC Ltd.-Tianjin Branch Tianjin China

The combined well pattern has been widely used in reservoir development, with a common pattern being a horizontal well in the center for oil production and multiple vertical wells around for water injection. For this type of well pattern, determining the horizontal well is affected by which injection wells, especially when the injecting water breaks through, accurately determining the direction of water inflow will provide an important basis for targeted water well measures. Based on the production performance data of horizontal wells, the semi logarithmic relationship curves of water-oil ratio, derivative water-oil ratio, and cumulative production were used for the first time to determine the breakthrough problem of water injection in the surrounding water injection wells of horizontal wells based on their response characteristics. The adaptability of this method under different influencing factors was analyzed. Introducing the parameter of cumulative production not only preserves the variation trend of the derivative of water-oil ratio with time, but also facilitates the processing of actual production data.

关键词： Combined Well Pattern Multiple Water Breakthroughs in Horizontal Derivative of Water-Oil Ratio

Optimizing protected areas to boost the conservation of key protected wildlife in China

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The Innovation 2023年第3期4卷 55-62页

作者： Chunrong Mi Kai Song Liang Ma Jiliang Xu Baojun Sun Yuehua Sun Jianguo Liu Weiguo Du Key Laboratory of Animal Ecology and Conservation Biology Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China School of Ecology Shenzhen Campus of Sun Yat-sen UniversityShenzhen 518107China School of Ecology and Nature Conservation Beijing Forestry UniversityBeijing 100083China Center of Systems Integration and Sustainability Department of Fisheries and WildlifeMichigan State UniversityEast LansingMI 48823USA

To meet the challenge of biodiversity loss and reach the targets of the proposed Post-2020 Global Biodiversity Framework,the Chinese government updated the list of national key protected wildlife in 2021 and has been continually expanding the protected areas(PAs).However,the status of protected wildlife in PAs remains unclear.In this study,we conducted a national assessment of the status of protected wildlife and suggested an optimization plan to overcome these shortcomings.From 1988 to 2021,the number of protected species almost doubled,and the area of PAs increased by 2.4 times,covering over 92.8%of the protected species.Nonetheless,some protected species have less than 10%of their habitat included in PAs.Despite the significant addition of amphibians and reptiles to the latest protection list,they are the fewest species and are the least covered by PAs compared with birds and mammals.To fix these gaps,we systematically optimized the current PAs network by adding another 10.0%of China’s land area as PAs,which resulted in 37.6%coverage of protected species’habitats in PAs.In addition,26 priority areas were identified.Our research aimed to identify gaps in current conservation policies and suggest optimization solutions to facilitate wildlife conservation planning in China.In general,updating the list of key protected wildlife species and systematically optimizing PA networks are essential and applicable to other countries facing biodiversity loss.

关键词： protected habitat optimization

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基于单目视觉实时测量桥式起重机负载摆角

上海海事大学学报 2024年第2期45卷 111-118页

作者：刘建国徐为民上海海事大学物流科学与工程研究院上海201306

针对目前基于视觉的桥式起重机负载摆角测量方法实时性较低,且没有考虑由运动模糊导致的测量精度下降问题,将一个对旋转和倾斜不敏感的球形标识物安装在负载上,设计一种计算灰度概率分布特征余弦相似度的方法,结合卡尔曼滤波器实时跟踪... 详细信息

针对目前基于视觉的桥式起重机负载摆角测量方法实时性较低,且没有考虑由运动模糊导致的测量精度下降问题,将一个对旋转和倾斜不敏感的球形标识物安装在负载上,设计一种计算灰度概率分布特征余弦相似度的方法,结合卡尔曼滤波器实时跟踪标识物。提出一种基于背景灰度值的局部自适应分割算法,使模糊边缘变清晰。从感兴趣区域(region of interest,ROI)的中心向周围8个方向寻找灰度梯度最大的点作为模糊图像的边缘点,对这些点采用最小二乘法进行拟合确定标识物位置。通过几何关系模型计算负载摆角。实验结果表明,本文方法在图像模糊情况下的测量精度和实时性能更优。

关键词：桥式起重机单目视觉卡尔曼滤波摆角测量模糊图像

Utilizing Dynamic Data to Quickly Evaluate Advantageous Channels and Applications

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World Journal of Engineering and Technology 2023年第3期11卷 417-423页

作者： Jianguo Liu Rui Zhang Zheng Lv Meinan Wang Guohao Zhang Tianjin Branch of CNOOC Ltd. Tianjin China

In response to the high cost and difficulty of high-speed development and testing data in offshore oil fields, this paper proposes to use the most easily available production performance data as the basis and use the grey correlation method to calculate the correlation coefficient between oil and water wells to characterize the degree of development of advantageous channels. The consistency between the calculated results of this method and the tracer test results is over 80%. Based on the fitting results, the correlation coefficient exceeds 0.74 to determine the existence of an advantageous channel. According to the research results of grey correlation method, Bohai K oilfield has completed the combined profile control and flooding measures, and the daily oil production has increased by 20 m3/d. This method is simple, fast, and can achieve quantitative evaluation, which saves time and investment compared to offshore testing. It has strong application and reference value for the development of other offshore water injection oilfields.

关键词： Offshore Oil Fields Production Performance Correlation Coefficient Advantageous Channel Quantitative Assessment

Research on Well Testing Interpretation of Low Permeability Deformed Dual Medium Reservoir

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Open Journal of Applied Sciences 2023年第11期13卷 2141-2148页

作者： Meinan Wang Yue Xie Rui Zhang Guohao Zhang Jianguo Liu Bohai Oilfield Research Institute of CNOOC Ltd.-Tianjin Branch Tianjin China

Considering the influence of quadratic gradient term and medium deformation on the seepage equation, a well testing interpretation model for low permeability and deformation dual medium reservoirs was derived and established. The difference method was used to solve the problem, and pressure and pressure derivative double logarithmic curves were drawn to analyze the seepage law. The research results indicate that the influence of starting pressure gradient and medium deformation on the pressure characteristic curve is mainly manifested in the middle and late stages. The larger the value, the more obvious the upward warping of the pressure and pressure derivative curve;the parameter characterizing the dual medium is the crossflow coefficient. The channeling coefficient determines the time and location of the appearance of the “concave”. The smaller the value, the later the appearance of the “concave”, and the more to the right of the “concave”.

关键词： Low Permeability Oil Reservoirs Deformation Medium Dual Media Cross Flow Coefficient Well Testing Interpretation Model