assembly

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  • 文章类型: Journal Article
    人类免疫缺陷病毒(HIV)-1的组装是通过Gag与质膜(PM)的内部小叶结合而启动的。Gag靶向由其N-末端肉豆蔻酰化基质(MA)结构域和PM磷脂酰肌醇4,5-二磷酸[PI(4,5)P2]介导。在Gag集会上,包膜(Env)糖蛋白被募集到组装位点;该过程取决于Gag的MA结构域和Env细胞质尾。为了调查Env招聘的动态,我们应用化学二聚体系统通过可逆PI(4,5)P2消耗结合超分辨率和活细胞显微镜来操纵HIV-1组装。这种方法使我们能够控制和同步HIV-1组装,并实时跟踪Env招募到各个新生组装地点。单病毒体追踪显示Gag和Env在HIV-1组装位点以相似的动力学积累。PI(4,5)P2耗尽阻止GagPM靶向和Env簇形成,确认Env招聘的Gag依赖性。在显示预组装Gag晶格的单元格中,PI(4,5)P2耗尽导致完整组装域的解体,因为不仅Gag而且Env集群都从PM中迅速丢失。这些结果证明了Gag诱导和维持的膜微环境的存在,这吸引了Env。PI(4,5)P2耗尽引起的Gag团簇解离显然破坏了这种微环境,导致从以前的组装域中丢失Env。IMPORTANCEHuman免疫缺陷病毒(HIV)-1在感染细胞的质膜上组装,导致膜包裹的病毒体出芽。HIV-1组装是由HIV-1的主要结构蛋白Gag启动的复杂过程。有趣的是,HIV-1仅将少数包膜(Env)糖蛋白掺入出芽的病毒体中,尽管在表达HIV的细胞的质膜上检测到新生Gag组件周围的大量Env积累。Gag的基质结构域和Env细胞质尾巴在Env募集到HIV-1组装位点及其掺入新生病毒体中起作用。然而,这些过程的调节还没有完全理解。通过结合化学二聚化系统来操纵具有超分辨率和活细胞显微镜的HIV-1组装,我们的研究为Gag之间的相互作用提供了新的见解,Env,在病毒组装过程中和宿主细胞膜,并将Env掺入HIV-1病毒体中。
    Human immunodeficiency virus (HIV)-1 assembly is initiated by Gag binding to the inner leaflet of the plasma membrane (PM). Gag targeting is mediated by its N-terminally myristoylated matrix (MA) domain and PM phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]. Upon Gag assembly, envelope (Env) glycoproteins are recruited to assembly sites; this process depends on the MA domain of Gag and the Env cytoplasmic tail. To investigate the dynamics of Env recruitment, we applied a chemical dimerizer system to manipulate HIV-1 assembly by reversible PI(4,5)P2 depletion in combination with super resolution and live-cell microscopy. This approach enabled us to control and synchronize HIV-1 assembly and track Env recruitment to individual nascent assembly sites in real time. Single virion tracking revealed that Gag and Env are accumulating at HIV-1 assembly sites with similar kinetics. PI(4,5)P2 depletion prevented Gag PM targeting and Env cluster formation, confirming Gag dependence of Env recruitment. In cells displaying pre-assembled Gag lattices, PI(4,5)P2 depletion resulted in the disintegration of the complete assembly domain, as not only Gag but also Env clusters were rapidly lost from the PM. These results argue for the existence of a Gag-induced and -maintained membrane micro-environment, which attracts Env. Gag cluster dissociation by PI(4,5)P2 depletion apparently disrupts this micro-environment, resulting in the loss of Env from the former assembly domain.IMPORTANCEHuman immunodeficiency virus (HIV)-1 assembles at the plasma membrane of infected cells, resulting in the budding of membrane-enveloped virions. HIV-1 assembly is a complex process initiated by the main structural protein of HIV-1, Gag. Interestingly, HIV-1 incorporates only a few envelope (Env) glycoproteins into budding virions, although large Env accumulations surrounding nascent Gag assemblies are detected at the plasma membrane of HIV-expressing cells. The matrix domain of Gag and the Env cytoplasmatic tail play a role in Env recruitment to HIV-1 assembly sites and its incorporation into nascent virions. However, the regulation of these processes is incompletely understood. By combining a chemical dimerizer system to manipulate HIV-1 assembly with super resolution and live-cell microscopy, our study provides new insights into the interplay between Gag, Env, and host cell membranes during viral assembly and into Env incorporation into HIV-1 virions.
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  • 文章类型: Journal Article
    4-硝基苯酚(4-NP)的高效催化还原是工业和实际工程研究的热点之一。因为4-NP是生态环境和人类健康最重要的污染源之一。这里,通过一步合成方法成功开发了柱[5]芳烃(P5A)和金纳米颗粒(AuNPs)的共组装混合复合材料,作为一种用于还原4-NP的水不溶性催化剂。几何和拓扑结构,以及AuNPs/P5A复合催化剂的理化性质,通过透射电子显微镜(TEM)等各种测试进行了充分的表征和分析,X射线衍射(XRD)和傅里叶变换红外光谱(FTIR),这表明AuNP很好地分散在组装的P5A的二维膜的表面上。对4-NP催化还原的影响因素进行了进一步的研究和讨论,证实了在催化过程中AuNP的含量和4-NP的浓度非常显著。在30°C下,在100mg·L-1的催化剂浓度和90mg·L-1的初始4-NP浓度下进行催化反应。计算的反应速率常数为0.3959min-1,4-NP在20min内的还原率大于95%。此外,所制备的催化剂在5次循环后仍能保持较高的催化效率。因此,易回收的复合催化剂水溶液较差,可用于水中4-NP的处理。
    Efficient catalytic reduction of 4-nitrophenol (4-NP) is one focus of industry and practical engineering, because 4-NP is one of the most important sources of pollution of the ecological environment and human health. Here, coassembled hybrid composites of pillar[5]arene (P5A) and gold nanoparticles (Au NPs) were successfully developed by a one-step synthetic method as a type of water-insoluble catalyst for the reduction of 4-NP. The geometric and topological structures, as well as physiochemical properties of Au NPs/P5A composite catalyst, were fully characterized and analyzed through various tests such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), indicating that Au NPs were well dispersed on the surface of the two-dimensional film of assembled P5A. The influence factors of the catalytic reduction of 4-NP were further investigated and discussed, confirming that the content of Au NPs and the concentration of 4-NP were very significant during the catalysis. The catalytic reaction was carried out at the catalyst concentration of 100 mg·L-1 and an initial 4-NP concentration of 90 mg·L-1 under 30 °C. The calculated reaction rate constant was 0.3959 min-1 and the reduction rate of 4-NP was more than 95% in 20 min. In addition, the as-prepared catalyst can maintain a high catalytic efficiency after five cycles. Thus, the easily recyclable composite catalyst with poor aqueous solution can exhibit prospective application to the treatment of 4-NP in water.
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  • 文章类型: Journal Article
    近年来,基于一维纳米结构的器件已经在各个领域得到了广泛的应用,如传感器,能量采集器,晶体管,和电极由于其特殊和独特的性能。1964年贝尔实验室R.S.Wagner博士的开创性工作介绍了气-液-固(VLS)过程,一种强大的合成方法。从那以后,众多的合成技术,包括溶胶-凝胶,热液,化学气相沉积(CVD)物理气相沉积(PVD),还有更多,已经开发了。这些方法使研究人员能够有效地控制纳米线的形状(长度和直径)和材料特性。然而,大约二十年前,纳米线开始被广泛用作功能器件的关键部件,主要是由于缺乏适当的集成方法。尽管已经开发了数十种集成技术,没有一个成为主导选择,每种方法都有自己的优点和局限性。因此,这项工作旨在根据其工作原理对这些方法进行分类,并提供其优缺点的全面总结。此外,介绍了利用一维纳米材料集成的最先进的设备。
    In recent years, 1D nanostructure-based devices have achieved widespread usage in various fields, such as sensors, energy harvesters, transistors, and electrodes owing to their exceptional and distinct properties. The pioneering work of Dr. R. S. Wagner at Bell Laboratories in 1964 introduced the vapor-liquid-solid (VLS) process, a powerful synthesis method. Since then, numerous synthesis techniques, including sol-gel, hydrothermal, chemical vapor deposition (CVD), physical vapor deposition (PVD), and more, have been developed. These methods have enabled researchers to effectively control the shape (length and diameter) and material properties of nanowires. However, it was only about two decades ago that nanowires started to be widely utilized as key components in functional devices, primarily due to the lack of proper integration methods. Although dozens of integration techniques have been developed, none have emerged as a predominant choice, with each method presenting its own set of advantages and limitations. Therefore, this work aims to categorize these methods based on their working principles and provide a comprehensive summary of their pros and cons. Additionally, state-of-the-art devices that capitalize on the integration of 1D nanomaterials are introduced.
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  • 文章类型: Journal Article
    协同相互作用凝胶(SIG)可以通过混合魔芋葡甘露聚糖(KGM)和κ-角叉菜胶,并已用于修饰和改善食品体系的流变学和质地特性。然而,它们之间的组装行为尚不清楚。这项工作表明,KGM的存在可能通过促进熵增加来促进附近κ-角叉菜胶分子的相变。随后,κ-角叉菜胶的其余部分转化为螺旋结构,组装成一系列横向排列的三角单元,并形成一个三维网络。在KGM/κ-角叉菜胶SIG中,随着KGM含量的增加,聚集体中高密度域(Ξ)的大小和这些高密度域(ζ)的距离先变窄,然后增大。这些纳米级结构特征导致比例为1:9(K1C9)和3:7(K3C7)的KGM/κ-角叉菜胶SIG的相对较高的凝胶强度。这项研究有助于促进具有必要性能特征的SIG的设计和生产。
    The synergistic interaction gels (SIGs) can be created by blending konjac glucomannan (KGM) and κ-carrageenan, and have been applied to modify and improve the rheological and texture properties of food system. However, the assembly behaviors between them are still unclear. This work revealed that the presence of KGM promoted phase transition of nearby κ-carrageenan molecules probably by contributing to entropy increment. Subsequently, the rest of κ-carrageenan transformed into helical structure, assembled into a series of laterally arranged trigonal units and formed a three-dimensional network. In KGM/κ-carrageenan SIGs, the size of high density domains (Ξ) in aggregates and the distance of these high density domains (ξ) were narrowed firstly and then enlarged as increasing of KGM content. These nano-scale structure features were responsible for the relative higher gel strength for KGM/κ-carrageenan SIGs with proportion ratios of 1:9 (K1C9) and 3:7 (K3C7). This study serves to facilitate the design and production of SIGs with the requisite performance characteristics.
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  • 文章类型: Journal Article
    微/纳米马达代表一类有前途的药物递送载体,能够将周围的化学能或外部能转化为机械动力,实现自主运动。它们独特的自主推进力使它们区别于其他航母,为增强药物在细胞和组织屏障中的渗透提供了巨大的潜力。全面了解具有各种电源的微/纳米运动动力学对于促进其从概念验证到临床应用的过渡至关重要。在这次审查中,微型/纳米马达根据其能量来源分为三类:内源性刺激,外生刺激,活细胞驱动。该综述总结了在这些能源下控制微/纳米运动的机制,并探讨了影响自主运动的因素。此外,它讨论了控制微/纳米运动的方法,涵盖与它们的结构相关的方面,composition,和环境因素。微/纳米马达所表现出的显着推进力使它们对重要的生物医学应用有价值,包括肿瘤治疗,生物检测,细菌感染治疗,炎症治疗,胃肠疾病治疗,和环境修复。最后,该综述讨论了微/纳米马达应用的挑战和前景。总的来说,这篇综述强调了微/纳米马达在克服生物障碍和增强治疗功效方面的转化潜力,突出了它们在各个生物医学领域的有前途的临床应用。
    Micro/nanomotors represent a promising class of drug delivery carriers capable of converting surrounding chemical or external energy into mechanical power, enabling autonomous movement. Their distinct autonomous propulsive force distinguishes them from other carriers, offering significant potential for enhancing drug penetration across cellular and tissue barriers. A comprehensive understanding of micro/nanomotor dynamics with various power sources is crucial to facilitate their transition from proof-of-concept to clinical application. In this review, micro/nanomotors are categorized into three classes based on their energy sources: endogenously stimulated, exogenously stimulated, and live cell-driven. The review summarizes the mechanisms governing micro/nanomotor movements under these energy sources and explores factors influencing autonomous motion. Furthermore, it discusses methods for controlling micro/nanomotor movement, encompassing aspects related to their structure, composition, and environmental factors. The remarkable propulsive force exhibited by micro/nanomotors makes them valuable for significant biomedical applications, including tumor therapy, bio-detection, bacterial infection therapy, inflammation therapy, gastrointestinal disease therapy, and environmental remediation. Finally, the review addresses the challenges and prospects for the application of micro/nanomotors. Overall, this review emphasizes the transformative potential of micro/nanomotors in overcoming biological barriers and enhancing therapeutic efficacy, highlighting their promising clinical applications across various biomedical fields.
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  • 文章类型: Journal Article
    精确控制金属纳米粒子(NP)在嵌段共聚物中的空间分布和排列对于制造具有所需光学和电子性能的新型纳米材料非常重要。在这里,我们开发了一种简单而通用的策略来制备由乳液液滴中的聚苯乙烯-嵌段-聚(4-乙烯基吡啶)(PS-b-P4VP)和PS系金纳米颗粒(AuNPs@PS)共组装形成的有机/无机纳米片。嵌段共聚物(BCP)/AuNP纳米片内的AuNP@PS结构单元的排列可以通过调节有效尺寸比(λeff)来调节,这可以通过AuNP的核心直径和PS的分子量来控制。此外,AuNP的含量也是操纵具有特定λeff的纳米片结构的另一个基本参数。因此,通过调整λeff和AuNP的含量,成功制备了具有可控分布和AuNP排列的BCP/AuNP杂化纳米片。这项研究提供了一种简单的方法来制造有序的混合纳米片。
    Precisely controlling the spatial distributions and arrangements of metal nanoparticles (NPs) into block copolymers is of great importance for fabricating novel nanomaterials with the desired optical and electronic properties. Herein, we develop a simple yet versatile strategy to prepare organic/inorganic nanosheets formed by the coassembly of polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) and PS tethered gold nanoparticles (AuNPs@PS) within emulsion droplets. The arrangement of the AuNPs@PS building blocks within the block copolymers (BCP)/AuNPs nanosheets can be adjusted by tuning the effective size ratio (λeff), which can be controlled by the core diameter of the AuNPs and the molecular weight of the PS. Furthermore, the content of the AuNPs is also another essential parameter to manipulate the structures of the nanosheets with the specific λeff. Thus, the BCP/AuNPs hybrid nanosheets with controllable distributions and arrangements of the AuNPs were successfully prepared via tuning of λeff and the content of AuNPs. This study provides a facile way to fabricate well-ordered hybrid nanosheets.
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  • 文章类型: Journal Article
    已经开发了体内自组装策略以改善抗癌药物在肿瘤组织中的富集和长期保留。然而,大多数具有非共价键相互作用的自组装体对复杂的生理环境敏感,导致弱的稳定性和生物功能的丧失。这里,我们开发了一种耦合诱导组装(CIA)策略来产生共价交联的纳米纤维,用于在线粒体上原位构建人工外壳。合成了氧化响应肽-卟啉缀合物P1,自组装成纳米粒子。在线粒体的氧化微环境下,P1中硫醇的偶联导致二聚体的形成,其进一步有序并堆叠成交联的纳米纤维。因此,由于结合位点的增加,人工壳通过多价协同相互作用有效地构建在线粒体上。在超声(US)照射下,壳中的卟啉分子产生大量的活性氧(ROS),作用于相邻的线粒体膜,在体外和体内表现出比纳米颗粒高~2倍的抗肿瘤活性。因此,线粒体靶向CIA策略为改进的声动力疗法(SDT)提供了新的视角,并显示了在抗肿瘤治疗中的潜在应用.
    The strategy of in vivo self-assembly has been developed for improved enrichment and long-term retention of anticancer drug in tumor tissues. However, most self-assemblies with non-covalent bonding interactions are susceptible to complex physiological environments, leading to weak stability and loss of biological function. Here, we develop a coupling-induced assembly (CIA) strategy to generate covalently crosslinked nanofibers, which is applied for in situ constructing artificial shell on mitochondria. The oxidation-responsive peptide-porphyrin conjugate P1 is synthesized, which self-assemble into nanoparticles. Under the oxidative microenvironment of mitochondria, the coupling of thiols in P1 causes the formation of dimers, which is further ordered and stacked into crosslinked nanofibers. As a result, the artificial shell is constructed on the mitochondria efficiently through multivalent cooperative interactions due to the increased binding sites. Under ultrasound (US) irradiation, the porphyrin molecules in the shell produce a large amount of reactive oxygen species (ROS) that act on the adjacent mitochondrial membrane, exhibiting ~2-fold higher antitumor activity than nanoparticles in vitro and in vivo. Therefore, the mitochondria-targeted CIA strategy provides a novel perspective on improved sonodynamic therapy (SDT) and shows potential applications in antitumor therapies.
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  • 文章类型: Journal Article
    在负链RNA病毒中,核糖核蛋白,不是裸露的RNA,构成具有聚合酶活性的大蛋白质用于复制和转录病毒基因组的模板。在这里,我们概述了来自静脉病毒的核糖核蛋白的结构和功能。核衣壳单体,构成基本结构单元,具有柔性臂,允许在闭合单体状态和形成聚合丝状结构之间进行构象转换,该结构可在N的开放状态下进行病毒RNA结合和衣壳化。描述了N-N寡聚化模式以及与vRNA的相互作用。最后,层析成像的最新进展为更全面地了解N-L相互作用和特定抗病毒化合物的设计开辟了令人兴奋的前景。
    In negative strand RNA viruses, ribonucleoproteins, not naked RNA, constitute the template used by the large protein endowed with polymerase activity for replicating and transcribing the viral genome. Here we give an overview of the structures and functions of the ribonucleoprotein from phleboviruses. The nucleocapsid monomer, which constitutes the basic structural unit, possesses a flexible arm allowing for a conformational switch between a closed monomeric state and the formation of a polymeric filamentous structure competent for viral RNA binding and encapsidation in the open state of N. The modes of N-N oligomerization as well as interactions with vRNA are described. Finally, recent advances in tomography open exciting perspectives for a more complete understanding of N-L interactions and the design of specific antiviral compounds.
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  • 文章类型: Journal Article
    在这里,氧化的3,3\',开发了5,5'-四甲基联苯胺(oxTMB)纳米带,以增强H2O2的比色和纸基传感。研究发现,Na2SO4试剂中的少量Fe2成分可以催化H2O2将TMB氧化为带正电荷的oxTMB,通过与SO42-的静电相互作用进一步组装成深蓝色的oxTMB纳米带。源自oxTMB纳米带的吸收和散射的消光被用于定量检测H2O2,具有宽的线性检测范围(1.0-300μM)和低的检测限(0.48μM)。此外,在纸基比色阵列的测试区中没有观察到咖啡环效应,有利于肉眼判断颜色。最后,采用比色法检测隐形眼镜护理液中的H2O2。这项工作不仅提出了一种新的H2O2比色传感平台,而且还强调了试剂中的次要成分可能会影响实验结果。
    Herein, oxidized 3,3\',5,5\'-tetramethylbenzidine (oxTMB) nanobelts were developed to enhance the colorimetric and paper-based sensing of H2O2. It was found that the minor component of Fe2+ in Na2SO4 reagent could catalyze the oxidization of TMB by H2O2 into positively charged oxTMB, which was further assembled into dark blue oxTMB nanobelts via electrostatic interaction with SO42-. The extinction originating from the absorption and scattering of oxTMB nanobelts was utilized to quantitatively detect H2O2 with a wide linear detection range (1.0-300 μM) and a low limit of detection (0.48 μM). In addition, no coffee-ring effect was observed in the test zone of the paper-based colorimetric array, which was beneficial to judge the color by naked eye. Finally, the colorimetric method was applied to detect H2O2 in contact lens care solution. This work not only proposed a new colorimetric sensing platform for H2O2, but also highlighted the minor component in the reagent might influence the experimental result.
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  • 文章类型: Journal Article
    具有可编码特性的光子异质结构作为微型和纳米级的通用信息载体已显示出巨大的价值。这些异质结构通常通过逐步生长或后官能化方法来制备,以实现不同结构单元之间的不同发射颜色。为了实现高通量、多变量信息加载,我们在这里报告了一种将极化信号集成到光子异质结中的策略。通过强的分子间Pt····Pt相互作用,将U形di-Pt(II)配合物组装成高度极化的黄色磷光晶体微棒(Y棒)。在最终引发引入的CH2Cl2溶剂的解吸后,Y棒以多米诺方式转化为具有交替的红-黄-红发射或红色磷光微棒(R棒)的三块极化光子异质结(PPH)。这些结构的红色发射也是高度极化的;然而,它们的偏振方向与Y棒的黄色磷光方向正交。借助图案化的掩模,通过侧向允许的CH2Cl2蒸气吸附,将R-rod进一步编程为具有精确控制的嵌段尺寸的多嵌段PPH。X射线衍射分析和理论计算表明,分子内和分子间激发态的溶剂调节调制对于这些PPH的构建至关重要。
    Photonic heterostructures with codable properties have shown great values as versatile information carriers at the micro and nanoscale. These heterostructures are typically prepared by a step-by-step growth or post-functionalization method to achieve varied emission colors among different building blocks. In order to realize high-throughput and multivariate information loading, we report here a strategy to integrate polarization signals into photonic heterojunctions. A U-shaped di-Pt(II) complex is assembled into highly-polarized yellow-phosphorescent crystalline microrods (Y-rod) by strong intermolecular Pt···Pt interaction. Upon end-initiated desorption of the incorporated CH2Cl2 solvents, Y-rod is transformed in a domino fashion into tri-block polarized photonic heterojunctions (PPHs) with alternate red-yellow-red emissions or red-phosphorescent microrods (R-rod). The red emissions of these structures are also highly polarized; however, their polarization directions are just orthogonal to those of the yellow phosphorescence of Y-rod. With the aid of a patterned mask, R-rod is further programmed into multi-block PPHs with precisely-controlled block sizes by side-allowed adsorption of CH2Cl2 vapor. X-ray diffraction analysis and theoretical calculations suggest that the solvent-regulated modulation of intramolecular and intermolecular excited states is critical for the construction of these PPHs.
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