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Click and bioorthogonal hyaluronic acid hydrogels as an ultra-tunable platform for the investigation of cell-material interactions

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Bioactive Materials 2023年第6期24卷 438-449页

作者： Nathan Lagneau Pierre Tournier Boris Halgand François Loll Yves Maugars Jérôme Guicheux Catherine Le Visage Vianney Delplace Nantes Université OnirisCHU NantesINSERMRegenerative Medicine and SkeletonRMeSUMR 1229F-44000France

The cellular microenvironment plays a major role in the biological functions of ***,biomaterials,especially hydrogels,which can be design to mimic the cellular microenvironment,are being increasingly used for cell encapsulation,delivery,and 3D culture,with the hope of controlling cell ***,much remains to be understood about the effects of cell-material interactions,and advanced synthetic strategies need to be developed to independently control the mechanical and biochemical properties of *** address this challenge,we designed a new hyaluronic acid(HA)-based hydrogel platform using a click and bioorthogonal strain-promoted azide-alkyne cycloaddition(SPAAC)*** approach facilitates the synthesis of hydrogels that are easy to synthesize and sterilize,have minimal swelling,are stable long term,and are *** provides bioorthogonal HA gels over an uncommonly large range of stiffness(0.5-45 kPa),all forming within 1-15 *** importantly,our approach offers a versatile one-pot procedure to independently tune the hydrogel composition(e.g.,polymer and adhesive peptides).Using this platform,we investigate the independent effects of polymer type,stiffness,and adhesion on the secretory properties of human adipose-derived stromal cells(hASCs)and demonstrate that HA can enhance the secretion of immunomodulatory factors by hASCs.

关键词： Hydrogels Click and bioorthogonal chemistry Hyaluronic acid mesenchymal stromal cells Cell-material interactions Secretome

Solar wind transport into magnetosphere caused by magnetic reconnection at high latitude magnetopause during northward iMF: Cluster-DSP conjunction observations

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Science China(Technological Sciences) 2008年第10期51卷 1677-1684页

作者： M. DUNLOP e. LUCeK H. Rme C. M. CARR Rutherford Appleton Laboratory Didcot United Kingdom imperial College of Science Technology and Medicine London United Kingdom CeSR BP4346 31028 Toulouse Cedex 4 France

An event of Cluster-Double Star conjunction observations of magnetic reconnec-tion at high latitude magnetopause nightside of both cusps and solar wind trans-port into magnetosphere caused by such reconnection process has been investi-gated. During northward iMF, Cluster/SC1 observed accelerated flows and ion heating associated with magnetic reconnection at high latitude magnetopause nightside of southern cusp. And Double Star observed cold dense solar wind plasma transported into dayside magnetosphere. The analysis on such conjunction observations shows that: (1) during northward iMF, magnetic reconnection occurs at high latitude nightside of southern cusp, accompanied by accelerated flows that are observed by Cluster/SC1; (2) the direction of the accelerated flows, with its sunward component Vx, dawnward component Vy, northward component Vz, is quite consistent with the theoretical anticipation under the condition of northward iMF with dawnward component By; (3) reconnection can heat plasma more in par-allel direction than in perpendicular direction, to a level of about 4 keV; (4) with reconnection taking place at high latitude magnetopause nightside of the southern cusp, TC-1 observed cold and dense plasma transported into magnetosphere; (5) by reconnection at high latitude magnetopause nightside of both cusps, solar wind flux tube can be captured by magnetosphere and pulled into dayside magneto-sphere. This event presents further observational evidence for magnetic reconnec-tion at high latitude magnetopause nightside of both cusps as an important mech-anism of sol-ar w-ind transport into magnetosphere.

关键词： transport process magnetic reconnection solar wind-magnetosphere interactions

基于映射空间编码的高速运动轨道图像去模糊研究

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铁道科学与工程学报 2024年第2期21卷 812-825页

作者：鄢化彪刘词波黄绿娥赵恒江西理工大学理学院江西赣州341000 江西理工大学电气工程与自动化学院江西赣州341000 中铁二院工程集团有限责任公司四川成都610000

针对轨道缺陷检测系统因镜头抖动或相机快速移动而导致所采集图像较为模糊的问题,提出一种基于最大后验概率估计思想的映射空间编码的高速运动轨道图像去模糊算法。首先,该算法使用深度编解码器和残差网络分别对数据集中清晰图像到模糊... 详细信息

针对轨道缺陷检测系统因镜头抖动或相机快速移动而导致所采集图像较为模糊的问题,提出一种基于最大后验概率估计思想的映射空间编码的高速运动轨道图像去模糊算法。首先,该算法使用深度编解码器和残差网络分别对数据集中清晰图像到模糊图像的映射关系和模糊核进行编码,为了保证编码时频率信息的完整性,算法在传统的残差模块上引入快速傅里叶变换通道构成双通道残差网络,以补偿多次特征提取带来的频率损失;其次,算法采用深度图像先验(Deep image Prior,diP)将潜在的清晰图像和模糊核进行参数化,再利用先验得到的模糊核和清晰图像来调用编码空间中的映射关系;最后,通过交替优化潜在的清晰图像和模糊核,从而去逼近一个真实未知的映射,进而实现真实场景下高速运动轨道图像的去模糊。实验结果表明,双通道残差模块提取的特征图频率信息分量强度普遍高于传统的残差模块,相较于使用传统残差模块实现该算法,采用双通道残差模块可使峰值信噪比(Peak Signal-to-Noise Ratio,PSNR)提升0.84 dB,结构相似性(Structural Similarity,SSiM)提高0.025 1。与现有的深度学习去模糊算法相比,提出的去模糊算法对高速轨道检测系统所采集图像的去模糊效果更佳,在性能方面相较于最好的去模糊算法,PSNR提高了1.84 dB,SSiM提升了0.017 3,显著提升了采集图像的质量。研究结果可为下一步识别轨道部件是否存在缺陷提供清晰图像。

关键词：运动去模糊编码-解码器映射空间深度图像先验残差网络

Magnetoresistivity studies for BiPb-2223 phase added by BaSnO3 nanoparticles

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Journal of Advanced Ceramics 2017年第2期6卷 100-109页

作者： Mai me.BARAKAT Khulud HABANJAR Department of Physics Faculty of Science Alexandria University Alexandria Egypt Department of Physics Faculty of Science Beirut Arab University Beirut Lebanon

Co-precipitation method and conventional solid-state reaction technique were used to synthesize BaSnO3 nanoparticles and (BaSnO3) x /Bi1.6Pb0.4Sr2Ca2Cu3O10+δ (0 ≤ x ≤ 1.50 wt%) samples, respectively. X-ray powder diffraction (XRD), scanning electron microscopy (SeM), and electrical resistivity data were used to characterize BiPb-2223 phase added by BaSnO3 nanoparticles. The relative volume fraction and superconducting transition temperature Tc of BiPb-2223 phase were enhanced by increasing BaSnO3 addition up to 0.50 wt%. These parameters were decreased with further increase of x. The resistive transition broadening under different applied DC magnetic fields (0.29–4.40 kG) was analyzed through thermally activated flux creep (TAFC) model and Ambegaokar–Halperin (AH) theory. improvements of the derived flux pinning energy U, critical current density Jc (0) estimated from AH parameter C(B), and upper critical magnetic field Bc2 (0), were recorded by adding BaSnO3 nanoparticles up to 0.50 wt%, beyond which these parameters were suppressed. The magnetic field dependence of the flux pinning energy and critical current density decreased as a power-law relation, which indicated the single junction sensitivity between the superconducting grains to the applied magnetic field. Furthermore, the increase in the applied magnetic field did not affect the electronic thermal conductivity κe above the superconducting transition temperature and suppressed it below Tc.

关键词： BiPb-2223 BaSnO 3 nanoparticles flux pinning energy critical current density

Dependency-aware unequal erasure protection codes

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2006年第Z1期7卷 27-33页

作者： BOUABDALLAH Amine LACAN Jérme Laboratory for Analysis and Architecture of Systems Toulouse 31077 France Applied Mathematics and Computer Science DepartmentENSICAToulouse 31056France Telecommunications for Space and AeronauticToulouse 31000France

Classical unequal erasure protection schemes split data to be protected into classes which are encoded independently. The unequal protection scheme presented in this paper is based on an erasure code which encodes all the data together according to the existing dependencies. A simple algorithm generates dynamically the generator matrix of the erasure code according to the packets streams structure, i.e., the dependencies between the packets, and the rate of the code. This proposed erasure code was applied to a packetized MPeG4 stream transmitted over a packet erasure channel and compared with other classical protection schemes in terms of PSNR and mos. it is shown that the proposed code allows keeping a high video quality-level in a larger packet loss rate range than the other protection schemes.

关键词： Data dependencies integration Unequal erasure protection (UeP) Lossy networks Reliable video transmissions MPeG4 video codec

碳排放约束下广西城市建设用地利用效率特征分析

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智能建筑与智慧城市 2024年第1期 6-9页

作者：唐惠婷李庆覃雪华谢达么徐冰冰王永卿南宁师范大学自然资源与测绘学院

土地利用/覆被变化是影响碳排放、碳吸收量变化的主要原因。本文通过碳排放系数间接估算法、HicksMoorsteen生产率指数分析广西2011年-2020年城镇建设用地利用效率动态变化,结果发现:(1)广西建设用地碳排放总量的变化趋势可分为“先升... 详细信息

土地利用/覆被变化是影响碳排放、碳吸收量变化的主要原因。本文通过碳排放系数间接估算法、HicksMoorsteen生产率指数分析广西2011年-2020年城镇建设用地利用效率动态变化,结果发现:(1)广西建设用地碳排放总量的变化趋势可分为“先升后降再升”三个阶段,地均碳排放总量整体呈“先降后升”的趋势,万元GDP碳排放量的变化呈平稳下降趋势;(2)广西全区HM指数呈现年平均4.87%的上升趋势,受综合利用效率(Δ_(e))和技术进步(Δ_(tech))共同驱动,各市城镇建设用地利用效率都出现微小波动的上升趋势,呈现出区域的非均衡性。广西应综合考虑各市城镇建设用地利用效率存在的问题,因地制宜实施产业转型、能源结构优化以及节能环保等政策。

关键词：建设用地碳排放土地利用效率 Hicks-Moorsteen指数广西

Gamma induced changes in Makrofol/CdSe nanocomposite films

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Chinese Physics B 2022年第9期31卷 547-553页

作者： Ali A.Alhazime M.me.Barakat Radiyah A.Bahareth e.M.Mahrous Saad Aldawood S.Abd el Aal S.A.Nouh Physics Department Faculty of ScienceTaibah UniversityMedinaSaudi Arabia Department of Physics Faculty of ScienceTaibah UniversityYanbuSaudi Arabia Department of Physics Faculty of ScienceAlexandria UniversityAlexandriaEgypt Physics Department College of ScienceJeddah UniversityJeddahSaudi Arabia Department of Physics and Astronomy College of ScienceP.O.BOX 2455King Saud UniversitySaudi Arabia Center of Radiation Research and Technology Egyptian Atomic AuthorityNasr CityCairoEgypt Qassim University P.B.6644Buraidah 51452QassimSaudi Arabia Physics Department Faculty of ScienceAin Shams UniversityCairoEgypt

We applied an ex-situ casting procedure to prepare a nanocomposite(NCP)from Makrofol polycarbonate(PC)and CdSe *** CdSe nanoparticles were prepared by a thermolysis procedure in the presence of N_(2) gas *** refinement of x-ray data illustrated that the CdSe adopts a cubic zinc blend structure of 6.057 A lattice parameter and 2 nm typical grain *** from the prepared NCP were exposed to γ dosages(20 kGy-250 kGy).The modifications induced in the NCP films owing to γ dosages have been ***γirradiation(50 kGy-250 kGy)causes crosslinks that reduce the optical bandgap from 4.15 eV to 3.81 eV,associated with an increase in dielectric parameters and refractive *** is attributed to an increase in the mass fraction of the disordered regions as specified by x-ray *** PC-CdSe NCP was found to have a reaction to color modification which makes it suitable for saleable reproduction on a printing press.

关键词： gamma nanocomposite x-ray dfraction UV spectra color changes

以基因通路为单元的大青杨伤口诱导不定根发生转录组分析

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以基因通路为单元的大青杨伤口诱导不定根发生转录组分析

作者： PAK SOL me 东北林业大学

学位级别：硕士

外伤诱导的不定根(AR)诱导是一种重要的再生技术,特别是在大青杨等树木的造林实践中对于树木的无性繁殖很重要,但对树木外伤诱导的AR发育的分子机制的了解不足,极大地限制了造林实践。最近,转录组数据挖掘工具,如差异基因表达分析(DeG)... 详细信息

外伤诱导的不定根(AR)诱导是一种重要的再生技术,特别是在大青杨等树木的造林实践中对于树木的无性繁殖很重要,但对树木外伤诱导的AR发育的分子机制的了解不足,极大地限制了造林实践。最近,转录组数据挖掘工具,如差异基因表达分析(DeG)、聚类(clustering)、基因集富集分析(GSeA)和加权基因共表达网络分析(WGCNA),在杨树的AR发育基因组研究中得到广泛应用,揭示了关于杨树(包括大青杨)AR发育分子机制的一定量的证据,但是那些知识零散并不全面。这主要是因为当前的转录组数据挖掘方法存在局限性。本研究发现了当前转录组数据挖掘方法存在着局限性,并对WGCNA进行修改以提高数据挖掘效率,最终成功获取了关于伤口诱导AR发育的分子机制的全面和综合的知识。(1)本研究发现了当前转录组数据挖掘方法的局限性。一般来说,因为转录组数据产生的基因数非常大(数万个),对于研究人员来说,从数万个基因高效地提取关键基因和通路是很不容易的事情。本研究的DeG或聚类分析结果也观察到了这一点。DeG分析表明,在9个时间点之间存在大量的DeG;根据log FC>1和peG。Clustering分析还将27487个基因聚类为几个簇,并根据表达趋势对其进行重新分组,结果,两个主要组包含14612和8765个基因,这些基因进一步注释为2948和2899个GO通路。从这些大量的基因和通路中,很难找到能够全面反映生物过程各个方面的关键通路或基因。之前研究都从这些大量的基因和通路中只提取感兴趣的基因和通路了,所以可以说那些知识不全面并不综合。(2)本研究修改了传统WGCNA分析的功能分析单元,从基因到基因集,以解决当前转录组数据挖掘方法的局限性。这类的修改已经应用于GSeA或GSVA分析,但尚未应用于WGCNA分析。本研究WGCNA分析的修改如下。本研究在GSeA结果中证明了总共694个GO和KeGG通路在大青杨的AR发育过程中的特定时间点显著富集的,这些基因集进一步用作预定义的基因集。然后将WGCNA分析应用于这预定义的694个基因集,而不是27487个基因。结果,在特定时间点确定了枢纽通路。接下来,只有枢纽通路中的基因(比常规WGCNA小得多)进行第二次WGCNA分析,从而更容易识别驱动枢纽通路的关键基因和调控网络的构建,这个WGCNA流程命名为“逐步WGCNA”(stepwise WGCNA)。本研究中,与DeG,Clustering和GSeA/GSVA相比,“逐步WGCNA”分析揭示了关于特定时间关键基因和基因通路以及调控网络的综合和全面的知识。(3)根据本研究“逐步WGCNA”结果,外伤应激诱导JAZ蛋白和eRF109转录因子的快速上调,该转录因子在0.5 h调节JA生物合成和信号传导(eRF109是从头表达的)。eRF109在1 h激活生长素生物合成基因促进生长素积累。2 h后,JA生物合成停止,而生长素生物合成也在6 h后停止,可能是由于e3泛素连接酶对JA或生长素水平的感知具有负反馈调节作用。6 h后,AR发育中细胞命运转变的主调节因子基因WOX11在很长一段时间内(6 h至48 h)从头表达和调节生长素转运和信号传导,细胞分裂和根分生组织生长以及根形态发生的下游途径。120 h时,与根分生组织生长和根形态发生相关的途径高度活化,PLT1转录因子在途径中起中心作用。总体而言,在本研究中新的数据挖掘方法的应用为外伤诱导的大青杨AR发育机理解析提供了全新的理论基础和基因资源。

关键词：大青杨不定根发育外伤基因集加权基因集共富集网络

Glucose-6-Phosphate Dehydrogenase Deficiency: difficulties in diagnosis at the Souro Sanou University Hospital, Burkina Faso

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Open Journal of Blood diseases 2023年第1期13卷 24-32页

作者： Salifo Sawadogo Koumpingnin Nébié Jerôme Kouldiati Catherine Traoré Salam Sawadogo Aimée S. Kissou eléonore Kafando Souro Sanou University Hospital Bobo-Dioulasso Burkina Faso National Blood Transfusion Center Ouagadougou Burkina Faso Yalgado Ouédraogo University Hospital Ouagadougou Burkina Faso Charles De Gaule University Pediatric Hospital Ouagadougou Burkina Faso

Glucose-6-phosphate dehydrogenase deficiency is the most common enzymopathy worldwide. The precise prevalence of G6PD is unknown in Burkina Faso. The objective of the study was to describe the difficulties to diagnose this disease at the Souro Sanou University hospital (CHUSS) in Bobo-dioulasso. it involved five patients comprising one child with homozygous SS sickle cell disease, one adolescent screened following a family investigation, and three adults including a man and two women. Blood smear stained with May Grunwald Giemsa was performed to look for specific signs of G6PD-deficient red blood cell and brilliant cresyl Blue for Heinz Bodies. A microscope Olympus BX53 equipped with a Camera (XC10) and connected to a computer was used to read blood smears and capture images. Genes sequencing by Sanger method were performed in a specialized laboratory in molecular genetics. For each analysis, the protocol and instructions of the equipment and reagent manufacturer were applied. Of the five patients, three had anemia and only one had hyperreticulocytosis. Two patients had biological signs of hemolysis and one patient had an elevated CRP. Blood smear stained with MGG and cresyl blue showed specific signs of G6PD-deficient red blood cells and Heinz bodies in all patients. Biochemical analysis and molecular typing confirmed G6PD deficiency. The presence of G6PD-deficient red blood cells in the blood smear guides the diagnosis of G6PD deficiency. The diagnosis is biochemical and is based on the combined measurement of G6PD plus pyruvate kinase and/or hexokinase.

关键词： G6PD Deficiency G6PD-Deficient Red Cell diagnosis difficulties Burkina Faso