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| 1 | Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China显示文摘To control the spread of the 2019 novel coronavirus(COVID-19),China imposed nationwide restrictions on the movement of its population(lockdown)after the Chinese New Year of 2020,leading to large reductions in economic activities and associated emissions.Despite such large decreases in primary pollution,there were nonetheless several periods of heavy haze pollution in eastern China,raising questions about the well-established relationship between human activities and air quality.Here,using comprehensive measurements and modeling,we show that the haze during the COVID lockdown was driven by enhancements of secondary pollution.In particular,large decreases in NOx emissions from transportation increased ozone and nighttime NO_(3)radical formation,and these increases in atmospheric oxidizing capacity in turn facilitated the formation of secondary particulate matter.Our results,afforded by the tragic natural experiment of the COVID-19 pandemic,indicate that haze mitigation depends upon a coordinated and balanced strategy for controlling multiple pollutants. | Xin Huang Aijun Ding Jian Gao Bo Zheng Derong Zhou Ximeng Qi Rong Tang Jiaping Wang Chuanhua Ren Wei Nie Xuguang Chi Zheng Xu Liangduo Chen Yuanyuan Li Fei Che Nini Pang Haikun Wang Dan Tong Wei Qin Wei Cheng Weijing Liu Qingyan Fu Baoxian Liu Fahe Chai Steven JDavis Qiang Zhang Kebin He | 2021 | National Science Review2021,8,2: | 47 |
| 2 | Polysaccharides from Angelica sinensis alleviate neuronal cell injury caused by oxidative stress显示文摘Angelica sinensis has antioxidative and neuroprotective effects. In the present study, we aimed to determine the neuroprotective effect of polysaccharides isolated from Angelica sinensis. In a preliminary experiment, Angelica sinensis polysaccharides not only protected PC12 neuronal cells from H 2 O 2-induced cytotoxicity, but also reduced apoptosis and intracellular reactive oxygen species levels, and increased the mitochondrial membrane potential induced by H 2 O 2 treatment. In a rat model of local cerebral ischemia, we further demonstrated that Angelica sinensis polysaccharides enhanced the antioxidant activity in cerebral cortical neurons, increased the number of microvessels, and improved blood flow after ischemia. Our findings highlight the protective role of polysaccharides isolated from Angelica sinensis against nerve cell injury and impairment caused by oxidative stress. | Tao Lei Haifeng Li Zhen Fang Junbin Lin Shanshan Wang Lingyun Xiao Fan Yang Xin Liu Junjian Zhang Zebo Huang Weijing Liao | 2014 | Neural Regeneration Research2014,9,3: | 17 |
| 3 | Atomic force microscopy imaging and mechanical properties measurement of red blood cells and aggressive cancer cells显示文摘Mechanical properties play an important role in regulating cellular activities and are critical for unlocking the mysteries of life. Atomic force microscopy (AFM) enables researchers to measure mechanical properties of single living cells under physiological conditions. Here, AFM was used to investigate the topography and mechanical properties of red blood cells (RBCs) and three types of aggressive cancer cells (Burkitt's lymphoma Raji, cutaneous lymphoma Hut, and chronic myeloid leukemia K562). The surface topography of the RBCs and the three cancer cells was mapped with a conventional AFM probe, while mechanical properties were investigated with a microsphere glued onto a tip-less cantilever. The diameters of RBCs are significantly smaller than those of the cancer cells, and mechanical measurements indicated that Young's modulus of RBCs is smaller than those of the cancer cells. Aggressive cancer cells have a lower Young's modulus than that of indolent cancer cells, which may improve our understanding of metastasis. | LI Mi LIU LianQing XI Ning WANG YueChao DONG ZaiLi XIAO XiuBin ZHANG WeiJing | 2012 | Science China(Life Sciences)2012,55,11: | 16 |
| 4 | Water-vapor source shift of Xinjiang region during the recent twenty years显示文摘这篇论文的目的是在过去的 20 年期间调查 Xinjiang 区域和他们的移动的气候水蒸汽来源。首先,原则和步粗略地被调整寻求水蒸汽来源。第二,在对流层的静止水蒸汽运输是打算的区分水蒸汽旁边来哪里从的气候 ERA-40 分析。另外,在运输之间的搭配和大气的列水蒸汽内容被分析。结果证明主要蒸汽来自 Xinjiang 的西方方面为季节中间月,除了 7 月当水蒸汽来自北方或西北方向时。水蒸汽来源是不同的不同季节,例如里海和地中海是来源在在 10 月的在 7 月的 1 月和 4 月,北方大西洋和北极海和黑海和里海分别地。在里面最近在 Xinjiang 上面的更多的水蒸汽与全球温暖来自高纬度和北极海的十年,和从与 1973-1986 的案例比较的地中海的更少。事实上,在画热带上的空气变得干燥,异常的水蒸汽运输方向在 1987-2000 期间转到西方或西南。由对比,在中间、高的纬度上的空气以前比 14 年更温暖、湿。 | Dai Xingang Li Weijing Ma Zhuguo Wang Ping | 2007 | Progress in Natural Science:Materials International2007,17,5: | 12 |
| 5 | Estimation of ground heat flux and its impact on the surface energy budget for a semi-arid grassland显示文摘Three approaches,i.e.,the harmonic analysis(HA) technique,the thermal diffusion equation and correction(TDEC) method,and the calorimetric method used to estimate ground heat flux,are evaluated by using observations from the Semi-Arid Climate and Environment Observatory of Lanzhou University(SACOL) in July,2008.The calorimetric method,which involves soil heat flux measurement with an HFP01SC self-calibrating heat flux plate buried at a depth of 5 cm and heat storage in the soil between the plate and the surface,is here called the ITHP approach.The results show good linear relationships between the soil heat fluxes measured with the HFP01SC heat flux plate and those calculated with the HA technique and the TDEC method,respectively,at a depth of 5 cm.The soil heat fluxes calculated with the latter two methods well follow the phase measured with the HFP01SC heat flux plate.The magnitudes of the soil heat flux calculated with the HA technique and the TDEC method are close to each other,and they are about 2 percent and 6 percent larger than the measured soil heat flux,respectively,which mainly occur during the nighttime.Moreover,the ground heat fluxes calculated with the TDEC method and the HA technique are highly correlated with each other(R2 = 0.97),and their difference is only about 1 percent.The TDEC-calculated ground heat flux also has a good linear relationship with the ITHP-calculated ground heat flux(R2 = 0.99),but their difference is larger(about 9 percent).Furthermore,compared to the HFP01SC direct measurements at a depth of 5 cm,the ground heat flux calculated with the HA technique,the TDEC method,and the ITHP approach can improve the surface energy budget closure by about 6 percent,7 percent,and 6 percent at SACOL site,respectively.Therefore,the contribution of ground heat flux to the surface energy budget is very important for the semi-arid grassland over the Loess Plateau in China.Using turbulent heat fluxes with common corrections,soil heat storage be-tween the surface and the heat flux plate can improve the surface energy budget closure by about 6 to 7 percent,resulting in a clo-sure of 82 to 83 percent at the SACOL site. | JinQing Zuo JieMin Wang JianPing Huang WeiJing Li GuoYin Wang HongLi Ren | 2011 | Research in Cold and Arid Regions2011,3,1: | 11 |
| 6 | Mapping CD20 molecules on the lymphoma cell surface using atomic force microscopy显示文摘Atomic force microscopy (AFM) was used to locate CD20 molecules on the surface of lymphoma Raji cells. Rituximab (a monoclonal antibody against CD20) molecules were linked onto the AFM tip via a polyethylene glycol (PEG) linker. Raji cells were adsorbed onto glass slides coated with poly-L-lysine. First, the CD20 distribution in a local area of the cell surface was visualized using the AFM lift scan mode. Second, 16 × 16 force curves were obtained from the same cell area to construct the CD20-rituximab binding force map. Finally, free rituximab was added to block the CD20 molecules on the cell surface and the lift phase image and CD20-rituximab force map were obtained again. The experimental results indicated that when the lift height was greater than the length of the PEG linker, no recognition sites were observed in the lift phase image. However, as the lift height decreased to the length of the PEG linker, some recognition sites were observed in the lift phase image and these sites were generally consistent with the pixels in the force map. After blocking, both the recognition sites in the lift phase image and the gray pixels in the binding force map decreased markedly. These results can improve our understanding of the distribution of protein molecules on the cell surface and facilitate further investigations into cellular functions. | LI Mi LIU LianQing XI Ning WANG YueChao DONG ZaiLi XIAO XiuBin ZHANG WeiJing | 2013 | Chinese Science Bulletin2013,58,13: | 6 |
| 7 | Atomic force microscopy imaging of live mammalian cells显示文摘Atomic force microscopy (AFM) was used to examine the morphology of live mammalian adherent and suspended cells. Time-lapse AFM was used to record the locomotion dynamics of MCF-7 and Neuro-2a cells. When a MCF-7 cell retracted, many small sawtooth-like filopodia formed and reorganized, and the thickness of cellular lamellipodium increased as the retraction progressed. In elongated Neuro-2a cells, the cytoskeleton reorganized from an irregular to a parallel, linear morphology. Suspended mammalian cells were immobilized by method combining polydimethylsiloxane-fabricated wells with poly-L-lysine electrostatic adsorption. In this way, the morphology of a single live lymphoma cell was imaged by AFM. The experimental results can improve our understanding of cell locomotion and may lead to improved immobilization strategies. | LI Mi LIU LianQing XI Ning WANG YueChao DONG ZaiLi XIAO XiuBin ZHANG WeiJing | 2013 | Science China(Life Sciences)2013,56,9: | 6 |
| 8 | Progress of AFM single-cell and single-molecule morphology imaging显示文摘Atomic force microscopy (AFM) can probe single living cells and single native membrane proteins in natural fluid environments with label-free high spatial resolution. It has thus become an important tool for cellular and molecular biology that significantly complements traditional biochemical and biophysical techniques such as optical and electron microscopy and X-ray crystallog-raphy. Imaging surface topography is the primary application of AFM in the life sciences. Since the early 1990s, researchers have used AFM to investigate morphological features of living cells and native membrane proteins with impressive results. Steady improvements in AFM techniques for imaging soft biological samples have greatly expanded its applications. Based on the authors' own research in AFM imaging of living cell morphologies, a review of sample preparation procedures for single-cell and single-molecule imaging experiments is presented, along with a summary of recent progress in AFM imaging of living cells and native membrane proteins. Finally, the challenges of AFM high-resolution imaging at the single-cell and single-molecule levels are discussed. | LI Mi LIU LianQing XI Ning WANG YueChao DONG ZaiLi XIAO XiuBin ZHANG WeiJing | 2013 | Chinese Science Bulletin2013,58,26: | 5 |
| 9 | Effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells investigated by atomic force microscopy显示文摘Cell mechanics plays an important role in cellular physiological activities. Recent studies have shown that cellular mechanical properties are novel biomarkers for indicating the cell states. In this article, temperature-controllable atomic force microscopy(AFM) was applied to quantitatively investigate the effects of temperature and cellular interactions on the mechanics and morphology of human cancer cells. First, AFM indenting experiments were performed on six types of human cells to investigate the changes of cellular Young's modulus at different temperatures and the results showed that the mechanical responses to the changes of temperature were variable for different types of cancer cells. Second, AFM imaging experiments were performed to observe the morphological changes in living cells at different temperatures and the results showed the significant changes of cell morphology caused by the alterations of temperature. Finally, by co-culturing human cancer cells with human immune cells, the mechanical and morphological changes in cancer cells were investigated. The results showed that the co-culture of cancer cells and immune cells could cause the distinct mechanical changes in cancer cells, but no significant morphological differences were observed. The experimental results improved our understanding of the effects of temperature and cellular interactions on the mechanics and morphology of cancer cells. | LI Mi LIU LianQing XI Ning WANG YueChao XIAO XiuBin ZHANG WeiJing | 2015 | Science China(Life Sciences)2015,58,9: | 5 |
| 10 | Study of rare earth element effect on microstructures and mechanical properties of an Al-Cu-Mg-Si cast alloy显示文摘The improvements of microstructures and properties of a high strength aluminum cast alloy were studied. The effects of rare earth elements on the microstructures and mechanical properties of the high strength cast alloy Al-Cu-Mg-Si were investigated. The result shows that the addition of rare earth elements can change the microstructures in refining the grain size of the alloy and making the needle-like and laminar eutectic Si to a granular Si. With the increase of the rare earth, the tensile strength and elongation of the alloy increase first and then fall down. The mechanical properties of the alloy will reach the highest value when the content of rare earth elements is about 0.7%. | WAN Weiwei HAN Jianmin LI Weijing WANG Jinhua | 2006 | Rare Metals2006,25,z2: | 5 |
| 11 | Role of MR-DWI and MR-PWI in the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbits显示文摘Objective: To detect the activity of tumor cells and tumor blood flow before and after the radiotherapy of implanted pulmonary VX-2 carcinoma in rabbit models by using magnetic resonance diffusion-weighted imaging(MR-DWI) and magnetic resonance perfusion weighted imaging(MR-PWI), and to evaluate the effectiveness and safety of the radiotherapy based on the changes in the MR-DWI and MR-PWI parameters at different treatment stages.Methods: A total of 56 rabbit models with implanted pulmonary VX-2 carcinoma were established, and then equally divided into treatment group and control group. MR-DWI and MR-PWI were separately performed using a Philips Acheiva 1.5T MRI machine(Philips, Netherland). MRI image processing was performed using special perfusion software and the WORKSPACE advanced workstation for MRI. MRDWI was applied for the observation of tumor signals and the measurement of apparent diffusion coefficient(ADC) values; whereas MR-PWI was used for the measurement of wash in rate(WIR), wash out rate(WOR), and maximum enhancement rate(MER). The radiation treatment was performed using Siemens PRIMUS linear accelerator. In the treatment group, the radiotherapy was performed 21 days later on a once weekly dosage of 1,000 c Gy to yield a total dosage of 5,000 c Gy.Results: The ADC parameters in the region of interest on DWI were as follows: on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values at the center and the edge of the lesions were 1.352 and 1.461 in the treatment group and control group(P>0.05). During weeks 0-1 after treatment, the t values at the center and the edge of the lesions were 1.336 and 1.137(P>0.05). During weeks 1-2, the t values were 1.731 and 1.736(P<0.05). During weeks 2-3, the t values were 1.742 and 1.749(P<0.05). During weeks 3-4, the t values were 2.050 and 2.127(P<0.05). During weeks 4-5, the t values were 2.764 and 2.985(P<0.05). The ADC values in the treatment group were significantly higher than in the control group. After the radiotherapy(5,000 c Gy), the tumors remarkably shrank, along with low signal on DWI, decreased signal on ADC map, and remarkably increased ADC values. As shown on PWI, on the treatment day for the implanted pulmonary VX-2 carcinoma, the t values of the WIR, WOR, and MER at the center of the lesions were 1.05, 1.31, and 1.33 in the treatment group and control group(P>0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.35, 1.07, and 1.51(P>0.05). During weeks 0-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 1.821, 1.856, and 1.931(P<0.05); in addition, the t values of the WIR, WOR, and MER at the edge of the lesions were 1.799, 2.016, and 2.137(P<0.05). During weeks 1-1 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.574, 2.156, and 2.059(P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 1.869, 2.058, and 2.057(P<0.05). During weeks 2-3 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.461, 2.098, and 2.739(P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.951, 2.625, and 2.154(P<0.05). During weeks 3-4 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.584, 2.107, and 2.869(P<0.05) and the t values of the WIR, WOR, and MER at the edge of the lesions were 2.057, 2.637, and 2.951(P<0.05). During weeks 4-5 after treatment, the t values of the WIR, WOR, and MER at the center of the lesions were 2.894, 2.827, and 3.285(P<0.05) and the t values of the WIR, WOR, andMER at the edge of the lesions were 3.45, 3.246, and 3.614(P<0.05). After the radiotherapy(500 c Gy), the tumors shrank on the T1 WI, WIR, WOR, and MER; meanwhile, the PWI parameter gradually decreased and reached its minimum value.Conclusions: MR-DWI and MR-PWI can accurately and directly reflect the inactivation of tumor cells and the tumor hemodynamics in rabbit models with implanted pulmonary VX-2 carcinoma, and thus provide theoretical evidences for judging the clinical effectiveness of radiotherapy for the squamous cell carcinoma of the lung. | Qiang Zhang Mingmin Zhang Zhaoxin Liu Baoqi Shi Fuliang Qi Haijiang Wang Yuan Lv Haijiao Jin Weijing Zhang | 2014 | Chinese Journal of Cancer Research2014,26,5: | 5 |
| 12 | A complete genome assembly of Glaciecola mesophila sp. nov. sequenced by using BIGIS-4 sequencer system显示文摘Using a pyrosequencing-based custom-made sequencer BIGIS-4, we sequenced a Gram-negative bacterium Glaciecola mesophila sp. nov. (Gmn) isolated from marine invertebrate specimens. We generated 152043 sequencing reads with a mean high-quality length of 406 bp, and assembled them using the BIGIS-4 post-processing module. No systematic low-quality data was detected beyond expected homopolymer-derived errors. The assembled Gmn genome is 5144318 bp in length and harbors 4303 annotated genes. A large number of metabolic genes correspond to various nutrients from surface marine invertebrates. Its abundant cold-tolerant and cellular signaling and related genes reveal a fundamental adaptation to low-temperature marine environment. | YUAN LiNa REN LuFeng LI YunTao HAN WeiJing YU Yong CHU YaNan LIU GuiMing YU Dan TENG MingJing WANG Liang WANG XuMin ZHOU XiaoGuang YU YuDe YU Jun | 2011 | Science China(Life Sciences)2011,54,9: | 4 |
| 13 | Clonal analysis reveals remarkable functional heterogeneity during hematopoietic stem cell emergence显示文摘 | Hui Ye Xiaobo Wang Zongcheng Li Fan Zhou Xianlong Li Yanli Ni Weijing Zhang Fuchou Tang Bing Liu Yu Lan | 2017 | Cell Research2017,27,8: | 4 |
| 14 | Improvement of 6–15 Day Precipitation Forecasts Using a Time-Lagged Ensemble Method显示文摘A time-lagged ensemble method is used to improve 6–15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model, version 2.0.1. The approach averages the deterministic predictions of precipitation from the most recent model run and from earlier runs, all at the same forecast valid time. This lagged average forecast(LAF) method assigns equal weight to each ensemble member and produces a forecast by taking the ensemble mean. Our analyses of the Equitable Threat Score, the Hanssen and Kuipers Score, and the frequency bias indicate that the LAF using five members at time-lagged intervals of 6 h improves 6–15 day forecasts of precipitation frequency above 1 mm d-1and 5 mm d-1in many regions of China, and is more effective than the LAF method with selection of the time-lagged interval of 12 or 24 h between ensemble members. In particular, significant improvements are seen over regions where the frequencies of rainfall days are higher than about 40%–50% in the summer season; these regions include northeastern and central to southern China, and the southeastern Tibetan Plateau. | JIE Weihua WU Tongwen WANG Jun LI Weijing LIU Xiangwen | 2014 | Advances in Atmospheric Sciences2014,31,2: | 4 |
| 15 | EXPERIMENTAL AND NUMERICAL STUDIES OF THE ANTI-PENETRATION PERFORMANCE OF SANDWICH PANELS WITH ALUMINUM FOAM CORES显示文摘Effects of face-sheet thickness and core thickness of sandwich panels, and shape of projectiles on the penetration resistance of sandwich panels were discussed, while typical penetration failure modes were presented. It was shown that the anti-penetration performance of sandwich panels was enhanced with the increase of face-sheet or core thickness; The penetration resistance of sandwich panels was shown to be strongest to blunt-shaped projectile impacts,weaker to hemispherical-nose-shaped projectile impacts, and weakest to conical-shaped projectile impacts. The corresponding numerical simulation was carried out using the finite element code LS-DYNA V970. Numerical results showed that the penetration time decreased with the increase of projectile impact velocity. | Fei Yang Weijing Niu Lin Jing Zhihua Wang Longmao Zhao Hongwei Ma | 2015 | Acta Mechanica Solida Sinica2015,28,6: | 3 |
| 16 | Structure and Corrosion Resistance of Microarc Oxidation Coatings on AZ91D Magnesium Alloy显示文摘Magnesium alloys are widely used as shells of 3C (computer, mobile phone and consumer electronics) equipments for its impressive mechanical and physical properties, such as low density, good resistance to electromagnetic radiation, suitable for high pressure diecasting and easily recycling, etc. But poor corrosion resistance confines its extensively application. In this paper, protective coatings was successfully prepared on AZ91D magnesium alloys by micro-arc oxidation (MAO) and painting process. Microstructures and phases of MAO coatings were invesgated with scanning electron microscope (SEM) and X-Ray diffractometer. Mechanical properties of MAO coating, such as adhesive force and corrosion resistance, were also tested. Results showed that MAO coatings were a good base for painting process. MAO coatings with paint have good adhesive properties to base metal and excellent corrosion resistance. Micro-arc oxidation with painting process is a good kind of surface treatment to improve the corrosion resistance of mobile phone shell made of AZ91D magnesium alloys. | Cui Shihai Han Jianmin Li Weijing Li Ronghua Zhu Xiaowen Wang Jinhua | 2004 | Journal of Rare Earths2004,22,z2: | 3 |
| 17 | BRAKE TEST OF SiCp/A356 BRAKE DISK AND INTERPRETATION OF EXPERIMENTAL RESULTS显示文摘材料性质是明显的在铝矩阵 composites 和铁和钢材料之间不同。在以一样的速度的刹车磁盘 braked 以后,铝刹车磁盘的平均温度 1.5 倍高于铁和钢刹车磁盘之一,铝刹车磁盘的热扩大值 2 倍大于铁和钢刹车磁盘之一。材料的机械性质减少,在另一方面,温度在 braking 期间通常增加因为材料扩大被抑制,在刹车磁盘的大热压力发生。第一,产生和刹车磁盘的破裂失败在 braking 期间是由三酒吧的应力的优点的分析品质上的热压力的原因在药品,然后引起热压力的五限制装裱并且夹变丑原则被总结。在 1:1 紧急情况刹车测试上的试验性的结果的底上,热压力和温度地被模仿;破裂失败的行为是由有限元素分析的解释半份量上。以二个方法为部分位置有重合的预报。最后根据分析和计算结果,它是结构设计和被总结的刹车磁盘的汇编观察的一般原则。 | YANG Zhiyong HAN Jianmin LI Weijing WANG Jinhua | 2007 | Chinese Journal of Mechanical Engineering2007,20,5: | 3 |
| 18 | Detecting CD20-Rituximab interaction forces using AFM single-molecule force spectroscopy显示文摘The invention of atomic force microscopy(AFM) has provided new technology for measuring specific molecular interaction forces.Using AFM single-molecule force spectroscopy(SMFS) techniques,CD20-Rimximab rupture forces were measured on purified CD20 proteins,Raji cells,and lymphoma patient B cells.Rimximab molecules were linked onto AFM tips using AFM probe functionalization technology,and purified CD20 proteins were attached to mica using substrate functionalization technology.Raji cells(a lymphoma cell line) or lymphoma patient cells were immobilized on a glass substrate via electrostatic adsorption and chemical fixation.The topography of the purified CD20 proteins,Raji cells,and patient lymphoma cells was visualized using AFM imaging and the differences in the rupture forces were analyzed and measured.The results showed that the rupture forces between the CD20 proteins on Raji cells and Rituximab were markedly smaller than those for purified CD20 proteins and CD20 proteins on lymphoma patient B cells.These findings provide an effective experimental method for investigating the mechanisms underlying the variable efficacy of Rituximab. | LI Mi LIU LianQing XI Ning WANG YueChao DONG ZaiLi LI GuangYong XIAO XiuBin ZHANG WeiJing | 2011 | Chinese Science Bulletin2011,56,35: | 3 |
| 19 | Influence maximization with limit cost in social network显示文摘Social networking service (SNS) applications are changing the way information spreads in online communities. As real social relationships are projected into SNS applications, word of mouth has been an important factor in the information spreading processes of those applications. By assuming each user needs a cost to accept some specific information, this paper studies the initial 'seed user' selection strategy to maximize information spreading in a social network with a cost budget. The main contributions of this paper are: 1) proposing a graphic SEIR model (gSEIR) by extending the epidemic compartmental model to simulate the dynamic information spreading process between individuals in the social network; 2) proposing a formal definition for the influence maximization problem with limit cost (IMLC) in social networks, and proving that this problem can be transformed to the weighted set-cover problem (WSCP) and thus is NP-Complete; 3) providing four different greedy algorithms to solve the IMLC problem; 4) proposing a heuristic algorithm based on the method of Lagrange multipliers (HILR) for the same problem; 5) providing two parts of experiments to test the proposed models and algorithms in this paper. In the first part, we verify that gSEIR can generate similar macro-behavior as an SIR model for the information spreading process in an online community by combining the micro-behaviors of all the users in that community, and that gSEIR can also simulate the dynamic change process of the statuses of all the individuals in the corresponding social networks during the information spreading process. In the second part, by applying the simulation result from gSEIR as the prediction of information spreading in the given social network, we test the effectiveness and efficiency of all provided algorithms to solve the influence maximization problem with cost limit. The result show that the heuristic algorithm HILR is the best for the IMLC problem. | WANG Yue HUANG WeiJing ZONG Lang WANG TengJiao YANG DongQing | 2013 | Science China(Information Sciences)2013,56,7: | 3 |
| 20 | Efficient and targeted drug/siRNA co-delivery mediated by reversibly crosslinked polymersomes toward anti-inflammatory treatment of ulcerative colitis (UC)显示文摘Co-delivery of anti-inflammatory siRNA and hydrophilic drug provides a promising approach for the treatment of ulcerative colitis (UC). However, lack of a suitable and efficient co-delivery carrier poses critical challenge against their utilization. We herein developed macrophage-targeting, reversibly crossli nked polymersomes (TKPR-RCP) based on the TKPR-modified, poly(ethyle ne glycol)-b-poly(trimethylene carbonate-codithiolane trimethylene carbonate)-b-polyethylenimine (PEG-P(TMC-DTC)-PEI) triblock copolymer, which could efficiently encapsulate TNF-α siRNA and dexamethasone sodium phosphate (DSP) in their hydrophilic core. The cationic PEI segments provided additional electrostatic interactions with cargo molecules to promote the encapsulatiion, and disulfide crosslinking of the polymersome membrane endowed the TKPR-RCP with high colloidal stability. Because the cationic PEI was embedded in the hydrophilic core, the polymersomes displayed neutral surface charge and thus possessed high serum stability. The TKPR-RCP co-encapsulating TNF-α siRNA and DSP could be efficiently internalized by macrophages (~98%) and undergo redox-responsive membrane de-crosslinking to accelerate cargo release in the cytoplasm, thus inducing efficient gene silencing and anti-inflammatory effect .Intravenous injectio n of the co-delivery TKPR-RCP mediated pote nt and cooperative anti-inflammatory effect in inflamed colons of UC mice, and significantly prevented animals from colonic injury. This study therefore provides a promising approach for the co-delivery of hydrophilic drug/siRNA toward the treatment of inflammatory bowel diseases. | Xin Xu Weijing Yang Qiujun Liang Yanan Shi Wenxin Zhang Xiao Wang Fenghua Meng Zhiyuan Zhong Lichen Yin | 2019 | Nano Research2019,12,3: | 2 |