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1.
Surface engineering of synthetic carriers is an essential and important strategy for drug delivery in vivo. However, exogenous properties make synthetic nanosystems invaders that easily trigger the passive immune clearance mechanism, increasing the retention effect caused by the reticuloendothelial systems and bioadhesion, finally leading to low therapeutic efficacy and toxic effects. Recently, a cell membrane cloaking technique has been reported as a novel interfacing approach from the biological/immunological perspective, and has proved useful for improving the performance of synthetic nanocarriers in vivo. After cell membrane cloaking, nanoparticles not only acquire the physiochemical properties of natural cell membranes but also inherit unique biological functions due to the presence of membrane-anchored proteins, antigens, and immunological moieties. The derived biological properties and functions, such as immunosuppressive capability, long circulation time, and targeted recognition integrated in synthetic nanosystems, have enhanced their potential in biomedicine in the future. Here, we review the cell membrane-covered nanosystems, highlight their novelty, introduce relevant biomedical applications, and describe the future prospects for the use of this novel biomimetic system constructed from a combination of cell membranes and synthetic nanomaterials. 相似文献
2.
Rong Chen Gui-Lin Zhuang Zhi-Ye Wang Yi-Jing Gao Zhe Li Cheng Wang Yang Zhou Ming-Hao Du Suyuan Zeng La-Sheng Long Xiang-Jian Kong Lan-Sun Zheng 《国家科学评论(英文版)》2021,8(9)
Photosynthesis in nature uses the Mn4CaO5 cluster as the oxygen-evolving center to catalyze the water oxidation efficiently in photosystem II. Herein, we demonstrate bio-inspired heterometallic LnCo3 (Ln = Nd, Eu and Ce) clusters, which can be viewed as synthetic analogs of the CaMn4O5 cluster. Anchoring LnCo3 on phosphorus-doped graphitic carbon nitrides (PCN) shows efficient overall water splitting without any sacrificial reagents. The NdCo3/PCN-c photocatalyst exhibits excellent water splitting activity and a quantum efficiency of 2.0% at 350 nm. Ultrafast transient absorption spectroscopy revealed the transfer of a photoexcited electron and hole into the PCN and LnCo3 for hydrogen and oxygen evolution reactions, respectively. A density functional theory (DFT) calculation showed the cooperative water activation on lanthanide and O−O bond formation on transition metal for water oxidation. This work not only prepares a synthetic model of a bio-inspired oxygen-evolving center but also provides an effective strategy to realize light-driven overall water splitting. 相似文献
3.
Ke Li Yingfeng Li Xinyu Wang Mengkui Cui Bolin An Jiahua Pu Jintao Liu Boyang Zhang Guijun Ma Chao Zhong 《国家科学评论(英文版)》2021,8(8)
Marine diatoms construct their hierarchically ordered, three-dimensional (3D) external structures called frustules through precise biomineralization processes. Recapitulating the remarkable architectures and functions of diatom frustules in artificial materials is a major challenge that has important technological implications for hierarchically ordered composites. Here, we report the construction of highly ordered, mineralized composites based on fabrication of complex self-supporting porous structures—made of genetically engineered amyloid fusion proteins and the natural polysaccharide chitin—and performing in situ multiscale protein-mediated mineralization with diverse inorganic materials, including SiO2, TiO2 and Ga2O3. Subsequently, using sugar cubes as templates, we demonstrate that 3D fabricated porous structures can become colonized by engineered bacteria and can be functionalized with highly photoreactive minerals, thereby enabling co-localization of the photocatalytic units with a bacteria-based hydrogenase reaction for a successful semi-solid artificial photosynthesis system for hydrogen evolution. Our study thus highlights the power of coupling genetically engineered proteins and polysaccharides with biofabrication techniques to generate hierarchically organized mineralized porous structures inspired by nature. 相似文献
4.
基因线路是生命体对自身生命过程控制的动态调控系统。在工程化的设计原理的指导下,人工基因线路是对天然基因调控线路进行简单化处理和重新编程,以及引入自然界不存在的人造法则。人工基因线路由遗传开关、生物振荡器、逻辑门等组成,以执行诸多调控功能。多种多样的人工基因线路设计与构建,不仅极大地促进了人们对生命调控基本规律的认识,也进一步丰富了人们对天然的生物系统进行改造、再创的手段,并为医药健康、农业环境和工业发酵等领域的实际需求提供了全新解决方案。虽然在过去20年里,人们在人工基因线路领域取得了丰硕的研究成果,但是细胞体内蕴含着的众多复杂生化反应和信号传导途径,为设计和组装具有更加高级功能的基因线路带来了挑战。相应地,如何实现微小细胞内复杂基因线路的可预测设计组装,如何保障基因线路在复杂的体内外环境下发挥稳健的功能,将成为未来几年人工基因线路研究的关键核心问题和势必克服的重大挑战。 相似文献
5.
首先介绍光合作用在国际及国内研究现状,进而简介当前光合作用合成生物学作为一个新兴学科其主要研究范围及进展,提出我国光合作用合成生物学研究目前面临提高其研究系统性、与需求更紧密结合及提高支持力度等需求。鉴于光合作用对未来粮食安全、能源安全及可持续性生态环境维持具有重要战略意义,其未来发展需聚焦于已有光合作用系统优化、光合系统与光合同化产物利用途径协同、跨物种间光合系统重构、全新光合途径构建、光合系统与生物材料耦合等研究方向。 相似文献
6.
我们仿造有超疏水性质和自清洁功能荷叶表面的微米鄄纳米双重结构,通过分子设计和大分子在溶液及凝聚过程中分子形态的控制,采用一步法浇铸成膜制备出相应的高分子仿生表面,得到了可与荷叶相媲美的超疏水性质和荷叶所不具备的疏油特性,该表面具备自清洁功能和“自修复”功能。 相似文献
7.
柴达木盆地农业生产条件及潜力分析 总被引：10，自引：0，他引：10
本文对柴达木盆地的农业自然条件进行了分析,并对光合生产潜力、光温生产潜力、光温水（气候）生产潜力及灌溉调节后的光温水生产潜力进行了计算,在此基础上,对提高柴达木盆地农业生产潜力的主要措施进行了讨论。 相似文献
8.
Ultrathin two-dimensional (2D) materials have attracted considerable attention for their unique physicochemical properties and promising applications; however, preparation of freestanding ultrathin 2D noble metal remains a significant challenge. Here, for the first time, we report use of a wet-chemical method to synthesize partially hydroxylated ultrathin Ir nanosheets (Ir-NSs) of only five to six atomic layers’ thickness. Detailed analysis indicates that the growth confinement effect of carbon monoxide and the partially hydroxylated surface play a critical role in formation of the ultrathin structure. The ultrathin Ir-NSs exhibit excellent performance for both the hydrogen evolution reaction and oxygen evolution reaction in a wide pH range, outperforming the state-of-the-art Pt/C and IrO2, respectively. Density-functional theory calculations reveal that the partial hydroxylation not only enhances the surface electron transfer between Ir-sites and intermediate O-species, but also guarantees efficient initial activation of bond cleavage of H-O-H for first-step H2O splitting. This, ultimately, breaks through barriers to full water splitting, with efficient electron transfer essentially maintained. 相似文献
9.
Oliva Saldanha Martha E. Brennich Manfred Burghammer Harald Herrmann Sarah K?ster 《Biomicrofluidics》2016,10(2)
The structural organization of metazoan cells and their shape are established through the coordinated interaction of a composite network consisting of three individual filament systems, collectively termed the cytoskeleton. Specifically, microtubules and actin filaments, which assemble from monomeric globular proteins, provide polar structures that serve motor proteins as tracks. In contrast, intermediate filaments (IFs) assemble from highly charged, extended coiled coils in a hierarchical assembly mechanism of lateral and longitudinal interaction steps into non-polar structures. IF proteins are expressed in a distinctly tissue-specific way and thereby serve to generate the precise plasticity of the respective cells and tissues. Accordingly, in the cell, numerous parameters such as pH and salt concentration are adjusted such that the generation of functional networks is ensured. Here, we transfer the problem for the mesenchymal IF protein vimentin to an in vitro setting and combine small angle x-ray scattering with microfluidics and finite element method simulations. Our approach is adapted to resolve the early assembly steps, which take place in the sub-second to second range. In particular, we reveal the influence of ion species and concentrations on the assembly. By tuning the flow rates and thus concentration profiles, we find a minimal critical salt concentration for the initiation of the assembly. Furthermore, our analysis of the surface sensitive Porod regime in the x-ray data reveals that the formation of first assembly intermediates, so-called unit length filaments, is not a one-step reaction but consists of distinct consecutive lateral association steps followed by radial compaction as well as smoothening of the surface of the full-width filament. 相似文献
10.
Immiscible aqueous phases, formed by dissolving incompatible solutes in water, have been used in green chemical synthesis, molecular extraction and mimicking of cellular cytoplasm. Recently, a microfluidic approach has been introduced to generate all-aqueous emulsions and jets based on these immiscible aqueous phases; due to their biocompatibility, these all-aqueous structures have shown great promises as templates for fabricating biomaterials. The physico-chemical nature of interfaces between two immiscible aqueous phases leads to unique interfacial properties, such as an ultra-low interfacial tension. Strategies to manipulate components and direct their assembly at these interfaces needs to be explored. In this paper, we review progress on the topic over the past few years, with a focus on the fabrication and stabilization of all-aqueous structures in a multiphase microfluidic platform. We also discuss future efforts needed from the perspectives of fluidic physics, materials engineering, and biology for fulfilling potential applications ranging from materials fabrication to biomedical engineering. 相似文献
11.
《中国科学院院刊(英文版)》2004,18(4):193-193
Marine fish will die if placed in fresh water and they cannot live in simple salt water. Instead, they need water that contains a mixture of different ingredients, as found in natural seawater. Conventional methods of making artificial seawater have shortcomings, because the water so achieved is only composed of mineral elements and lacks organic components similar to those in natural seawater. 相似文献
12.
在施主/受主荧光系统中,荧光猝灭可用于研究光致电子的转移。当样品中各组分的吸收谱及相应荧光谱存在严重交迭时,荧光检测不可避免地会受到内滤效应及荧光材料吸收深度的影响,造成猝灭率虚高的赝象。本文就三聚噻吩/富勒烯混合液的光谱校正进行研究,以便于正确评估施主与受主材料间的光致电子转移。 相似文献
13.
《Endeavour》2022,46(4):100845
Synthetic biology is often seen as the engineering turn in biology. Philosophically speaking, entities created by synthetic biology, from synthetic cells to xenobots, challenge the ontological divide between the organic and inorganic, as well as between the natural and the artificial. Entities such as synthetic cells can be seen as hybrid or transitory objects, or neo–things. However, what has remained philosophically underexplored so far is the impact these hybrid neo–things will have on (our phenomenological experience of) the living world. By extrapolating from Walter Benjamin’s account of how technological reproducibility affects the aura of art, we embark upon an exploratory inquiry that seeks to fathom how the technological reproducibility of life itself may influence our experience and understanding of the living. We conclude that, much as technologies that enabled reproduction corroded the aura of original artworks (as Benjamin argued), so too will the aura of life be under siege in the era of synthetic lifeforms. This article zooms in on a specific case study, namely the research project Building a Synthetic Cell (BaSyC) and its mission to create a synthetic cell–like entity, as autonomous as possible, focusing on the properties that differentiate organic from synthetic cells. 相似文献
14.
Weigang Chen Mingzhe Han Jianting Zhou Qi Ge Panpan Wang Xinchen Zhang Siyu Zhu Lifu Song Yingjin Yuan 《国家科学评论(英文版)》2021,8(5)
DNA digital storage provides an alternative for information storage with high density and long-term stability. Here, we report the de novo design and synthesis of an artificial chromosome that encodes two pictures and a video clip. The encoding paradigm utilizing the superposition of sparsified error correction codewords and pseudo-random sequences tolerates base insertions/deletions and is well suited to error-prone nanopore sequencing for data retrieval. The entire 254 kb sequence was 95.27% occupied by encoded data. The Transformation-Associated Recombination method was used in the construction of this chromosome from DNA fragments and necessary autonomous replication sequences. The stability was demonstrated by transmitting the data-carrying chromosome to the 100th generation. This study demonstrates a data storage method using encoded artificial chromosomes via in vivo assembly for write-once and stable replication for multiple retrievals, similar to a compact disc, with potential in economically massive data distribution. 相似文献
15.
Liuqing Yang Ce Zhang Xiwen Yu Yingfang Yao Zhaosheng Li Congping Wu Wei Yao Zhigang Zou 《国家科学评论(英文版)》2021,8(8)
Aerospace milestones in human history, including returning to the moon and manned Martian missions, have been implemented in recent years. Space exploration has become one of the global common goals, and to ensure the survival and development of human beings in the extraterrestrial extreme environment has been becoming the basic ability and technology of manned space exploration. For the purpose of fulfilling the goal of extraterrestrial survival, researchers in Nanjing University and the China Academy of Space Technology proposed extraterrestrial artificial photosynthesis (EAP) technology. By simulating the natural photosynthesis of green plants on the Earth, EAP converts CO2/H2O into fuel and O2 in an in-situ, accelerated and controllable manner by using waste CO2 in the confined space of spacecraft, or abundant CO2 resources in extraterrestrial celestial environments, e.g. Mars. Thus, the material loading of manned spacecraft can be greatly reduced to support affordable and sustainable deep space exploration. In this paper, EAP technology is compared with existing methods of converting CO2/H2O into fuel and O2 in the aerospace field, especially the Sabatier method and Bosch reduction method. The research progress of possible EAP materials for in-situ utilization of extraterrestrial resources are also discussed in depth. Finally, this review lists the challenges that the EAP process may encounter, which need to be focused on for future implementation and application. We expect to deepen the understanding of artificial photosynthetic materials and technologies, and aim to strongly support the development of manned spaceflight. 相似文献
16.
"分子模块设计育种创新体系"战略性先导科技专项以水稻为主,小麦、鲤等为辅,利用野生种、农家品种和主栽(养)优良品种等种质资源,综合运用基因组学、系统生物学、合成生物学等手段,解析高产、稳产、优质、高效等重要农艺(经济)性状的分子模块,揭示水稻复杂性状全基因组编码规律,发展多模块非线性耦合理论和"全基因组导航"分子模块设计育种技术,优化多模块组装的品种设计的最佳策略,建立从"分子模块"到"设计型品种"的现代生物技术育种创新体系,为实现全基因组水平多模块优化组装、培育新一代超级品种提供系统解决方案。文章介绍了该专项的背景、总体目标、研究内容、进展及发展展望。 相似文献
17.
Klaus H. Theopold 《Journal of The Franklin Institute》2005,342(6):586-591
The Franklin Institute, Philadelphia, Pennsylvania, awarded the 2004 Benjamin Franklin Medal in Chemistry to Harry B. Gray for his pioneering contributions in the field of electron transfer in metalloproteins. In a series of elegant and challenging experiments beginning in the late 70s, Gray and his coworkers have shown that the transfer of electrons in metalloproteins can proceed over long distances (~ 20 Å) and at fast rates. These experiments have involved the regiospecific functionalization of structurally characterized electron transfer proteins with ruthenium complexes, coupled with laser excitation and transient spectroscopy. Probing the effects of thermodynamic driving force, temperature, donor-acceptor distance and electronic coupling, Gray has shaped our detailed current understanding of the principles governing biological electron flow. The mechanism of electron transfer has been identified as electron tunneling mediated by the molecules separating donor and acceptor. Tunneling timetables have been established for various intervening media. Important biological processes like respiration and photosynthesis depend on facile electron transfer, and Gray's contribution serves as the fundamental basis for understanding these and many related reactions. 相似文献
18.
本文以马铃薯(Solanum tuberosum.L.)块茎为材料,研究了不同光诱导期间块茎近表皮内淀粉质体向叶绿体转化过程中叶绿素的形成和积累,光系统Ⅰ和光系统Ⅱ复合物的出现和发育,以及相应光化学活性的变化。结果表明:光诱导淀粉质体转化为叶绿体的过程,不仅是叶绿体不断发育,叶绿素和蛋白质成分不断形成、组装,使其光合机构不断完善的过程,也是相应光合功能不断完善的过程。在转化初期,叶绿素a的形成速度较快,光系统Ⅰ的发育较光系统Ⅱ快。 相似文献
19.
自然资源资产负债表是十八届三中全会为生态文明建设与社会经济可持续发展提出的全新概念。因此,探索各种自然资源资产负债表编制的框架与方法、界定并核算自然资源资产负债对于编制自然资源资产负债表具有极其重要的意义。本研究首先从自然资源资产负债的经济学本质出发,结合自然资源资产负债产生的前提、途径以及界定依据,阐述自然资源资产负债的基本内涵;在此基础上,从可再生资源数量变化、不可再生资源数量变化和自然资源质量变化三个方面对因自然资源“过度”消耗而产生的自然资源资产负债进行界定;最后,以森林资源、水资源、矿产资源和土地资源为研究对象,从资源可持续利用阈值和国家政策红线两个方面提出了自然资源资产负债核算的基本思路,以期为自然资源资产负债表中的负债界定及其核算提供借鉴。 相似文献
20.
Janna Tenenbaum-Katan Rami Fishler Barbara Rothen-Rutishauser Josué Sznitman 《Biomicrofluidics》2015,9(1)
At the onset of life in utero, the respiratory system begins as a liquid-filled tubular organ and undergoes significant morphological changes during fetal development towards establishing a respiratory organ optimized for gas exchange. As airspace morphology evolves, respiratory alveolar flows have been hypothesized to exhibit evolving flow patterns. In the present study, we have investigated flow topologies during increasing phases of embryonic life within an anatomically inspired microfluidic device, reproducing real-scale features of fetal airways representative of three distinct phases of in utero gestation. Micro-particle image velocimetry measurements, supported by computational fluid dynamics simulations, reveal distinct respiratory alveolar flow patterns throughout different stages of fetal life. While attached, streamlined flows characterize the shallow structures of premature alveoli indicative of the onset of saccular stage, separated recirculating vortex flows become the signature of developed and extruded alveoli characteristic of the advanced stages of fetal development. To further mimic physiological aspects of the cellular environment of developing airways, our biomimetic devices integrate an alveolar epithelium using the A549 cell line, recreating a confluent monolayer that produces pulmonary surfactant. Overall, our in vitro biomimetic fetal airways model delivers a robust and reliable platform combining key features of alveolar morphology, flow patterns, and physiological aspects of fetal lungs developing in utero. 相似文献