chirality

手性
  • 文章类型: Journal Article
    生物体中各种迷人的光学特性鼓励科学家开发仿生合成策略并模仿其独特的微观结构。灵感来自变色龙的皮肤,具有可调的颜色和卓越的灵活性,这项工作设计了蒸发诱导自组装技术来合成手性光子晶体薄膜。超声强化和添加剂辅助技术协同优化薄膜性能,在光学和机械方面。薄膜显示出相当大的刚性和优越的灵活性,可以经历多次机械变形。在不破坏手性向列结构的情况下,极限应变接近50%,超过大多数纤维素衍生的薄膜材料。它还集成了优异的光学性能。薄膜颜色可以通过调整光子带隙来覆盖整个可见区域,并且具有角度依赖性。它可以使对湿度和溶剂的反应,色度变化反映了刺激的程度。重要的是,这种结构依赖的颜色变化是可逆的。最后,光子晶体材料以其优良的力学特性和独特的光学特性被应用于安全领域。防伪材料设计包含光子晶体墨水,可重复的书写纸,信息隐藏胶片,和变色标签,具有环保的特点,经济,非破坏性的,和方便的身份验证。
    Various fascinating optical characteristics in organisms encourage scientists to develop biomimetic synthesis strategies and mimic their unique microstructure. Inspired by the Chameleon\'s skin with tunable color and superior flexibility, this work designs the evaporated-induced self-assembly technique to synthesize the chiral photonic crystal film. Ultrasonic-intensified and additive-assisted techniques synergistically optimize the film properties, on the aspects of optic and mechanic. The film shows considerable rigidity and superior flexibility, which can undergo multiple mechanical deformations. Without destroying the chiral nematic structure, the ultimate strain approaches 50%, which exceeds most cellulose-derived film materials. It also integrates excellent optical performance. The film color can cover the total visible region by tuning the photonic bandgap and has angle-dependent properties. It can make the response to humidity and solvents, and chromaticity variation reflects the degree of stimulation. Importantly, this structural-dependent color change is reversible. Lastly, the photonic crystal materials with excellent mechanics and unique optics have been applied in the security. The anti-counterfeiting material design contains photonic crystal ink, repeatable writing paper, information-hiding film, and color-changing labels, with the features of environmentally friendly, economical, non-destructive, and convenient for authentication.
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  • 文章类型: Journal Article
    硫氧还蛋白还原酶(TXNRD)的过表达在肿瘤发生中起着至关重要的作用。因此,设计TXNRD抑制剂是靶向抗癌药物开发的有前景的策略。然而,选择性差一直是一个挑战,导致临床上不可避免的毒性。在本文中,我们展示了开发基于高选择性手性金属络合物的TXNRD抑制剂的策略。通过操纵两个不同的弱相互作用基团的构象,我们优化了药物与TXNRD活性位点内的亲电子基团之间的相容性,以增强它们的非共价相互作用,从而有效地避免了共价药物相互作用产生的选择性差,在保证强抑制的基础上。详细的实验和计算结果表明,手性异构药物与TXNRD的活性位点结合,相互作用强度受到手性很好的调节。尤其是,介观构型,其中两个大的空间位阻活性基团位于药物的相对侧,表现出最高数量的非共价相互作用和对TXNRD的最有效抑制。一起来看,这项工作不仅为开发高选择性蛋白酶抑制剂提供了一种新的方法,但也揭示了未来应用的潜在机制。
    Overexpression of thioredoxin reductase (TXNRD) plays crucial role in tumorigenesis. Therefore, designing TXNRD inhibitors is a promising strategy for targeted anticancer drug development. However, poor selectivity has always been a challenge, resulting in unavoidable toxicity in clinic. Herein we demonstrate a strategy to develop highly selective chiral metal complexes-based TXNRD inhibitors. By manipulating the conformation of two distinct weakly interacting groups, we optimize the compatibility between the drug and the electrophilic group within the active site of TXNRD to enhance their non-covalent interaction, thus effectively avoids the poor selectivity deriving from covalent drug interaction, on the basis of ensuring the strong inhibition. Detailed experimental and computational results demonstrate that the chiral isomeric drugs bind to the active site of TXNRD, and the interaction strength is well modulated by chirality. Especially, the meso-configuration, in which the two large sterically hindered active groups are positioned on opposite sides of the drug, exhibits the highest number of non-covalent interactions and most effective inhibition on TXNRD. Taken together, this work not only provides a novel approach for developing highly selective proteinase inhibitors, but also sheds light on possible underlying mechanisms for future application.
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  • 文章类型: Journal Article
    最近,已经表明,具有两种不同的圆极化组合(或-)的两个设计良好的激光脉冲可以在定向的异核双原子分子中产生手性电子密度。随后,手性从电子Ra翻转到Sa到Ra到Sa等。对映体,周期在飞秒(fs)和阿秒(as)时域中。结果是通过定向NaK的量子动力学模拟获得的。在这里,我们研究了所有可能(++,-+,+-,-)两个设计合理的激光脉冲的圆偏振组合。因此,++和-以及-和-组合产生相反的电子对映异构体,e.g.Ra对Sa,随后是相反的周期性手性翻转,例如形成Ra至Sa至Ra至Sa等。相对于形式Sa至Ra至Sa至Ra等,周期在fs中,作为时域,分别。激光诱导的时空对称性来自第一性原理,并通过量子动力学模拟进行了说明。
    Recently it has been shown that two coincident well designed laser pulses with two different combinations of circular polarizations ( ++ or -+ ) can create chiral electronic densities in an oriented heteronuclear diatomic molecule. Subsequently, the chirality flips from the electronic Ra to Sa to Ra to Sa etc. enantiomers, with periods in the femtosecond (fs) and attosecond (as) time domains. The results were obtained by means of quantum dynamics simulations for oriented NaK. Here we investigate the electronic chirality flips in oriented RbCs induced by all possible ( ++ , -+ , +- , -- ) combinations of circular polarizations of two coincident well-designed laser pulses. Accordingly, the ++ and -- as well as the +- and -+ combinations generate opposite electronic enantiomers, e. g. Ra versus Sa, followed by opposite periodic chirality flips, e.g. form Ra to Sa to Ra to Sa  etc. versus form Sa to Ra to Sa to Ra  etc, with periods in the fs and as time domains, respectively. The laser induced spatio-temporal symmetries are derived from first principles and illustrated by quantum dynamics simulations.
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  • 文章类型: Journal Article
    我们在此报告了两个具有小环尺寸的螺旋碳纳米环的容易合成,环[6]对亚苯基-1,5-亚萘基([6]CPPNap1,5),和环[6]对亚苯基-1,5-蒽基([6]CPPAn1,5)。通过NMR和HR-MS确定结构。还获得了[6]CPPNap1,5的X射线单晶数据。通过DFT计算研究了应变能和外消旋过程。减小的环尺寸导致增加的环应变和升高的能量势垒。通过紫外-可见吸收研究了其光物理性质,荧光发射,和时间分辨荧光衰减。
    We herein report the facile synthesis of two helical carbon nanorings with small ring sizes, cyclo[6]paraphenylene-1,5-naphthylene ([6]CPPNap1,5), and cyclo[6]paraphenylene-1,5-anthrylene ([6]CPPAn1,5). The structures were determined by NMR and HR-MS. X-ray single-crystal data of [6]CPPNap1,5 was also achieved. The strain energy and racemization processes were investigated by DFT calculations. The reduced ring sizes result in increased ring strain and elevated energy barriers. The photophysical properties were studied by UV-Vis absorption, fluorescence emission, and time-resolved fluorescence decay.
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  • 文章类型: Journal Article
    手性代表生命系统中的基本属性,是自然界中的普遍现象。在自然环境和生物系统中识别和分析手性材料在临床上至关重要。化学,和生物科学。在手性分析中,有一个新兴的重点是开发具有特殊选择性的手性传感器,灵敏度,和稳定性,将其标记为研究的前沿领域。在过去的十年(2013-2023年),大约1990年有关各种手性材料在手性传感器中的应用的论文已经发表。生物材料和纳米材料在手性传感器的发展中有着重要的应用,占这些传感器中材料相关应用的26.67%和45.24%,分别;此外,手性纳米材料的发展与便携式、稳定的手性传感器的发展密切相关。天然手性材料,用作选择性识别单元,与具有良好物理和化学性能的载体结合,通过功能化形成各种功能性手性材料,提高了手性传感器的识别效率。在这篇文章中,从生物材料的角度来看,聚合物材料,纳米材料,和其他功能性手性材料,综述了手性传感器的应用,并对手性传感器的研究前景进行了展望。
    Chirality represents a fundamental attribute within living systems and is a pervasive phenomenon in the natural world. The identification and analysis of chiral materials within natural environments and biological systems hold paramount importance in clinical, chemical, and biological sciences. Within chiral analysis, there is a burgeoning focus on developing chiral sensors exhibiting exceptional selectivity, sensitivity, and stability, marking it as a forefront area of research. In the past decade (2013-2023), approximately 1990 papers concerning the application of various chiral materials in chiral sensors have been published. Biological materials and nanomaterials have important applications in the development of chiral sensors, which accounting for 26.67% and 45.24% of the material-related applications in these sensors, respectively; moreover, the development of chiral nanomaterials is closely related to the development of portable and stable chiral sensors. Natural chiral materials, utilized as selective recognition units, are combined with carriers characterized by good physical and chemical properties through functionalization to form various functional chiral materials, which improve the recognition efficiency of chiral sensors. In this article, from the perspective of biological materials, polymer materials, nanomaterials, and other functional chiral materials, the applications of chiral sensors are summarized and the research prospects of chiral sensors are discussed.
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  • 文章类型: Journal Article
    由于目前对其临床治疗无效,因此揭示与创伤诱发的异位骨化(tHO)的发生和发展有关的机制要求很高。先前的研究表明,硫化氢(H2S)对于干细胞的命运决定至关重要,提示在调节tHO发育中的潜在作用。在目前的研究中,我们发现肌腱损伤后硫转化途径中代谢酶的表达增强,导致H2S在tHO区域内积聚。内源性H2S的产生增加被证明可以促进肌腱源性干细胞(TDSC)的异常成骨活性,加速了THO的形成。抑制H2S产生的代谢酶或直接吸收H2S可以消除TDSC的成骨诱导和tHO的形成。机械上,通过RNA测序结合拯救实验,我们证明Ca2+/ERK通路的激活是H2S诱导的TDSC和tHO成骨承诺的下游分子事件。对于治疗策略的探索,在这项研究中,氧化锌纳米颗粒(ZnO)作为有效的H2S消除材料被验证为理想地停止了tHO的形成。此外,就纳米粒子的手性而言,D-ZnO或L-ZnO纳米颗粒在清除H2S和抑制tHO方面均优于R-ZnO纳米颗粒。我们的研究不仅从一个新的角度揭示了tHO通过内源性气体信号事件的机制,还提出了一个消除天然气生产过度的适用平台,从而帮助发展tHO的临床治疗。
    Unveiling of the mechanism involved in the occurrence and development of trauma-induced heterotopic ossification (tHO) is highly demanding due to current ineffective clinical treatment for it. Previous studies proposed that hydrogen sulfide (H2S) was vital for fate determination of stem cells, suggesting a potential role in the regulation of tHO development. In the current study, We found that expression of metabolic enzyme within sulfur conversion pathway was enhanced after tendon injury, leading to H2S accumulation within the tHO region. Increased production of endogenous H2S was shown to promote aberrant osteogenic activity of tendon-derived stem cells (TDSCs), which accelerated tHO formation. The inhibition of metabolic enzyme of H2S production or directly absorption of H2S could abolished osteogenic induction of TDSCs and the formation of tHO. Mechanistically, through RNA sequencing combined with rescue experiments, we demonstrated that activation of Ca2+/ERK pathway was the downstream molecular event of H2S-induced osteogenic commitment of TDSCs and tHO. For treatment strategy exploration, zine oxide nanoparticles (ZnO) as an effective H2S elimination material was validated to ideally halt the tHO formation in this study. Furthermore, in terms of chirality of nanoparticles, D-ZnO or L-ZnO nanoparticles showed superiority over R-ZnO nanoparticles in both clearing of H2S and inhibition of tHO. Our study not only revealed the mechanism of tHO through the endogenous gas signaling event from a new perspective, but also presented a applicable platform for elimination of the inordinate gas production, thus aiding the development of clinical treatment for tHO.
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  • 文章类型: Journal Article
    手性农药约占农药总量的40%。在使用杀虫剂的过程中,它将不可避免地流入地表水,甚至通过地表径流和其他方式渗透到地下水中,因此,影响水环境。尽管手性农药的对映体具有相同的物理和化学性质,他们的分布,比率,新陈代谢,毒性,等。在生物体中往往是不同的,有时甚至表现出完全相反的生物活动。在这篇文章中,不同类型手性农药如有机氯的选择性命运,有机磷,三唑,拟除虫菊酯和天然水体和沉积物中的其他手性农药,对水生生物的急性毒性,从慢性毒性等方面进行综述,进一步反映手性农药对映体对水环境中非靶标生物的风险。在这次审查中,我们希望通过手性农药对映体的毒性研究,进一步探讨其对人类社会的危害,从而为生化农药的开发和生产提供数据支持和理论依据。
    Chiral pesticides account for about 40% of the total pesticides. In the process of using pesticides, it will inevitably flow into the surface water and even penetrate into the groundwater through surface runoff and other means, as a consequence, it affects the water environment. Although the enantiomers of chiral pesticides have the same physical and chemical properties, their distribution, ratio, metabolism, toxicity, etc. in the organism are often different, and sometimes even show completely opposite biological activities. In this article, the selective fate of different types of chiral pesticides such as organochlorine, organophosphorus, triazole, pyrethroid and other chiral pesticides in natural water bodies and sediments, acute toxicity to aquatic organisms, chronic toxicity and other aspects are summarized to further reflect the risks between the enantiomers of chiral pesticides to non-target organisms in the water environment. In this review, we hope to further explore its harm to human society through the study of the toxicity of chiral pesticide enantiomers, so as to provide data support and theoretical basis for the development and production of biochemical pesticides.
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  • 文章类型: Journal Article
    强烈的圆二色性(CD)响应的动态控制在工程应用中至关重要,例如偏振操纵,传感,和成像。这里,我们提出并通过实验证明了在二维拓扑保护的超表面中通过连续介质(BIC)中的束束态实现宽带可调谐双CD响应,该超表面由全电介质Si手性光栅结构组成,该结构产生一对混合和退化的BIC模式和圆形二向色模式(CDM)作为CD操纵中的附加自由度。发现当BIC在垂直入射下隐藏时,通过CDM可以在1.6μm处实现近100%的奇异CD峰,而CD峰可以分为两个,其中当BIC模式在倾斜入射下激发时,峰值波长可以通过入射角在180nm的带宽上精确线性调谐。此外,由于BIC将Γ点处的各种偏振状态解耦到K空间中的不同位置,因此在引入手性光栅上的不对称扰动时,可以通过控制入射角来在CD峰值处任意实现从线性到圆形的输出偏振状态的动态调制。所提出的手性光栅超表面表现出独特的角度敏感可调谐CD光谱特性,使其成为高光谱和自旋选择性波前整形的理想选择,并在各种应用中拥有重要的前景,如光学安全,角度传感器,手性激光器,非线性滤波器,和其他有源手性光学器件。
    Dynamic control for a strong circular dichroism (CD) response is essential in engineering applications such as polarization manipulation, sensing, and imaging. Here, we propose and experimentally demonstrate a broadband tunable dual CD response via bound states in the continuum (BICs) in two-dimensional topologically protected metasurfaces composed of all-dielectric Si chiral grating structures that generate a pair of mixed and degenerated BIC mode and circular dichroic mode (CDM) as an additional degree of freedom in CD manipulation. It is found that a singular CD peak of nearly 100% at 1.6 μm can be achieved by CDM when BIC is hidden under normal incidence, while the CD peak can be split into two in which peak wavelengths can be precisely and linearly tuned over a bandwidth of 180 nm by the incident angle when the BIC mode is excited under oblique incidence. Additionally, dynamic modulation of output polarization states from linear to circular can be arbitrarily achieved at the split CD peaks by controlling the incident angle when asymmetry perturbations on chiral gratings are introduced due to the decoupling of various polarization states at Γ point by BIC to different positions in K space. The proposed chiral grating metasurface exhibits unique angle-sensitive tunable CD spectral characteristics, making it ideal for hyperspectral and spin-selective wavefront shaping, and holds significant promise in various applications such as optical security, angle sensors, chiral lasers, nonlinear filters, and other active chiral optical devices.
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  • 文章类型: Journal Article
    具有可控几何形状的DNA纳米管具有广泛的跨学科应用。当制备不同宽度或不同手性的DNA纳米管时,现有的方法需要反复设计和合成特定的DNA序列,这可能是昂贵和费力的。这里,我们提出了一种嵌入剂辅助的DNA瓦片组装方法,该方法可以使用相同的DNA链生产不同宽度和手性的DNA纳米管。通过在组装过程中调节嵌入剂的浓度,可以调节DNA瓦片的扭曲方向和程度,导致形成具有可控宽度和手性的DNA纳米管。此外,通过引入额外的嵌入剂和二次退火,右旋纳米管可以重新配置成不同的左旋纳米管。我们期望这种方法可以普遍应用于调节各种DNA瓦片和其他手性材料的自组装途径,推进DNA瓷砖组装的景观。
    DNA nanotubes with controllable geometries hold a wide range of interdisciplinary applications. When preparing DNA nanotubes of varying widths or distinct chirality, existing methods require repeatedly designing and synthesizing specific DNA sequences, which can be costly and laborious. Here, we proposed an intercalator-assisted DNA tile assembly method which enables the production of DNA nanotubes of diverse widths and chirality using identical DNA strands. Through adjusting the concentration of intercalators during assembly, the twisting direction and extent of DNA tiles could be modulated, leading to the formation of DNA nanotubes featuring controllable widths and chirality. Moreover, through introducing additional intercalators and secondary annealing, right-handed nanotubes could be reconfigured into distinct left-handed nanotubes. We expect that this method could be universally applied to modulating the self-assembly pathways of various DNA tiles and other chiral materials, advancing the landscape of DNA tile assembly.
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  • 文章类型: Journal Article
    手性在自然界中无处不在,与生物现象密切相关。源自自然的纳米材料,例如纤维素纳米晶体(CNCs)能够自组装成分层的手性向列型CNC膜,并赋予纳米和微米级的手性。然而,手性向列表面对细胞粘附的影响尚不清楚。在这里,我们提供的证据表明,与随机排列的各向同性CNC膜(I-CNC)相比,左手自组装的手性向列型CNC膜(L-CNC)显着改善了L929成纤维细胞的粘附。引入基于流体力显微镜(FluidFM)的单细胞力谱(SCFS)来评估L-CNC和I-CNC基底上的细胞粘附力,分别。使用这种方法,在L-CNC上培养24小时后,成熟L929成纤维细胞的最大粘附力为133.2nN,而L929成纤维细胞在相同条件下对I-CNC施加的最大粘附力为78.4nN。此外,瞬时单细胞力谱表明,细胞粘附力的这种差异在细胞粘附的早期阶段上升,L929成纤维细胞与L-CNC或I-CNC基底接触5s内。有趣的是,用RGD肽阻断跨膜整合素后,细胞粘附力的差异消失,表明整合素途径参与感测基底表面的手性。此外,免疫荧光染色和粘着斑蛋白的Westernblot分析表明,L-CNC底物上的talin表达和F-actin组装上调,而Y397-磷酸化粘着斑激酶(FAKY397)的表达无统计学差异,维古林,和α-肌动蛋白。我们的发现表明,talin的上调是促进细胞在L-CNC膜上粘附的关键因素。总的来说,这项工作提供了一个起点,通过自组装的纳米和微结构的手性向列型数控膜细胞粘附的调控,在组织工程和再生医学中具有潜在的实际应用。本文受版权保护。保留所有权利。
    Chirality is ubiquitous in nature, and closely related to biological phenomena. Nature-originated nanomaterials such as cellulose nanocrystals (CNCs) are able to self-assemble into hierarchical chiral nematic CNC films and impart handedness to nano and micro scale. However, the effects of the chiral nematic surfaces on cell adhesion are still unknown. Herein, this work presents evidence that the left-handed self-assembled chiral nematic CNC films (L-CNC) significantly improve the adhesion of L929 fibroblasts compared to randomly arranged isotropic CNC films (I-CNC). The fluidic force microscopy-based single-cell force spectroscopy is introduced to assess the cell adhesion forces on the substrates of L-CNC and I-CNC, respectively. With this method, a maximum adhesion force of 133.2 nN is quantified for mature L929 fibroblasts after culturing for 24 h on L-CNC, whereas the L929 fibroblasts exert a maximum adhesion force of 78.4 nN on I-CNC under the same condition. Moreover, the instant SCFS reveals that the integrin pathways are involved in sensing the chirality of substrate surfaces. Overall, this work offers a starting point for the regulation of cell adhesion via the self-assembled nano and micro architecture of chiral nematic CNC films, with potential practical applications in tissue engineering and regenerative medicine.
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