Heisenberg

Long-lived luminescent systems are developed based on pyrene-doped polymers, where the phosphorescence exhibits radiation-, concentration-, time-, and excitation-dependent characteristics at the same time.

Abstract

Materials exhibiting ultralong luminescent lifetime show promising applications in the fields of information encryption, sensing, and bioimaging. Herein, we present a low-cost and general strategy to achieve stimulus-responsive ultralong organic phosphorescence (UOP) based on pyrene chromophores doped into polymer matrices. The UOP of the resulted systems presents radiation-, concentration-, time-, and excitation-dependent characteristics. The UOP color can be turned from blue to red by changing the excitation wavelength or the concentration of chromophores. Experimental results prove that these characteristics are attributed to the consumption of triplet oxygen and the different aggregation states of chromophores in the polymer matrices. Finally, we demonstrate that these systems could be applied for multilevel information encryption. This work would promote further development of multi-responsive long-lived luminescent materials.

Synthetic polypeptide vesicles can regulate their membrane permeability via ordered transition of secondary conformations. Particularly, a transformation from extended β-strands to compact α-helices in response to reactive oxygen species reduces the vesicular wall thickness and remodels the membrane structure, thereby enhancing the membrane permeability for efficient nanoreaction, glucose-triggered insulin secretion and effective therapy of diabetes mellitus.

Abstract

In nature, the folding and conformation of proteins can control the cell or organelle membrane permeability and regulate the life activities. Here we report the first example of synthetic polypeptide vesicles that regulate their permeability via ordered transition of secondary conformations, in a manner similar to biological systems. The polymersomes undergo a β-sheet to α-helix transition in response to reactive oxygen species (ROS), leading to wall thinning without loss of vesicular integrity. The change of membrane structure increases the vesicular permeability and enables specific transport of payloads with different molecular weights. As a proof-of-concept, the polymersomes encapsulating enzymes could serve as nanoreactors and carries for glucose-stimulated insulin secretion in vivo inspired by human glucokinase, resulting in safe and effective treatment of type 1 diabetes mellitus in mouse models. This study will help understand the biology of biomembranes and facilitate the engineering of nanoplatforms for biomimicry, biosensing, and controlled delivery applications.

Fusion of benzofuran to either s-indacene or dicyclopenta[b,g]naphthalene results in two dramatically different outcomes depending upon heterocycle orientation. Whereas the “anti” isomers are unstable and hydrolyze readily to ring-opened products, the “syn” isomers are quite stable and afford molecules that either possess a high degree of antiaromaticity or exhibit pronounced diradical character.

Abstract

We examine the effects of fusing two benzofurans to s-indacene (indacenodibenzofurans, IDBFs) and dicyclopenta[b,g]naphthalene (indenoindenodibenzofurans, IIDBFs) to control the strong antiaromaticity and diradical character of these core units. Synthesis via 3-functionalized benzofuran yields syn-IDBF and syn-IIDBF. syn-IDBF possesses a high degree of paratropicity, exceeding that of the parent hydrocarbon, which in turn results in strong diradical character for syn-IIDBF. In the case of the anti-isomers, synthesized via 2-substituted benzofurans, these effects are decreased; however, both derivatives undergo an unexpected ring-opening reaction during the final dearomatization step. All the results are compared to the benzothiophene-fused analogues and show that the increased electronegativity of oxygen in the syn-fused derivatives leads to enhancement of the antiaromatic core causing greater paratropicity. For syn-IIDBF increased diradical character results from rearomati-zation of the core naphthalene unit in order to relieve this paratropicity.

Nature, Published online: 08 September 2021; doi:10.1038/d41586-021-02422-9

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The epigenome of macrophages can be reprogrammed by extracellular cues, but the extent to which different stimuli achieve this is unclear. Nuclear factor B (NF-B) is a transcription factor that is activated by all pathogen-associated stimuli and can reprogram the epigenome by activating latent enhancers. However, we show that NF-B does so only in response to a subset of stimuli. This stimulus specificity depends on the temporal dynamics of NF-B activity, in particular whether it is oscillatory or non-oscillatory. Non-oscillatory NF-B opens chromatin by sustained disruption of nucleosomal histone–DNA interactions, enabling activation of latent enhancers that modulate expression of immune response genes. Thus, temporal dynamics can determine a transcription factor’s capacity to reprogram the epigenome in a stimulus-specific manner.

Full insight into the dynamics of a coupled quantum system depends on the ability to follow the effect of a local excitation in real-time. Here, we trace the free coherent evolution of a pair of coupled atomic spins by means of scanning tunneling microscopy. Rather than using microwave pulses, we use a direct-current pump-probe scheme to detect the local magnetization after a current-induced excitation performed on one of the spins. By making use of magnetic interaction with the probe tip, we are able to tune the relative precession of the spins. We show that only if their Larmor frequencies match, the two spins can entangle, causing angular momentum to be swapped back and forth. These results provide insight into the locality of electron spin scattering and set the stage for controlled migration of a quantum state through an extended spin lattice.

A novel strategy to regulate the solvation sheath by introducing hydrogen bonds for constructing high‐performance lithium–metal batteries is proposed. Depending on the hydrogen bonding of the additives with both the anions of Li salt and the solvent, the regulated solvation sheath promoted the formation of desirable solid–electrolyte interphase with more LiF component and stabilized the electrolytes.

Abstract

The performance of Li anodes is extremely affected by the solvation of Li ions, leading to preferential reduction of the solvation sheath and subsequent formation of fragile solid–electrolyte interphase (SEI), Li dendrites, and low coulombic efficiency (CE). Herein, we propose a novel strategy to regulate the solvation sheath, through the introduction of intermolecular hydrogen bonds with both the anions of Li salt and the solvent by small amount additives. The addition of such hydrogen bonds reduced the LUMO energy level of anions in electrolyte, promoted the formation of a robust SEI, reduced the amount of free solvent molecules, and enhanced stability of electrolytes. Based on this strategy, flat and dense lithium deposition was obtained. Even under lean electrolytes, at a current density of 1 mA cm⁻² with a fixed capacity of 3 mAh cm⁻², the Li–Cu cells showed an impressive CE value of 99.2 %. The Li‐LiFePO₄ full cells showed long‐term cycling stability for more than 1000 cycles at 1 C, with a total capacity loss of only 15 mAh g⁻¹.

Poleward migrations of tropical cyclones have been observed globally, but their impact on coastal areas remains unclear. We investigated the change in global tropical cyclone activity in coastal regions over the period 1982–2018. We found that the distance of tropical cyclone maximum intensity to land has decreased by about 30 kilometers per decade, and that the annual frequency of global tropical cyclones increases with proximity to land by about two additional cyclones per decade. Trend analysis reveals a robust migration of tropical cyclone activity toward coasts, concurrent with poleward migration of cyclone locations as well as a statistically significant westward shift. This zonal shift of tropical cyclone tracks may be mainly driven by global zonal changes in environmental steering flow.

Nature, Published online: 28 January 2021; doi:10.1038/d41586-021-00249-y

New studies knock down a controversial report observing phosphine in the planet’s atmosphere.

Nature, Published online: 09 December 2020; doi:10.1038/d41586-020-03448-1

Laboratory-grown meat has been stuck in the experimental stage. For it to become a commercially viable industry, tissue needs to be grown efficiently at scale.

Nature, Published online: 04 November 2020; doi:10.1038/d41586-020-03066-x

Other nations are stepping up targets to reduce emissions — but the world will struggle to meet its goals.

Nature, Published online: 31 July 2020; doi:10.1038/d41586-020-02288-3

The pandemic is sabotaging the careers of researchers from under-represented groups, but institutions can help to staunch the outflow.

Nature, Published online: 15 July 2020; doi:10.1038/d41586-020-02059-0

Rice in deepwater paddy fields can survive a slow-rising flood by a remarkably rapid elongation of submerged stem sections. Two genes discovered to affect this process could aid targeted improvements in crop height and flood tolerance.

Nature, Published online: 03 July 2020; doi:10.1038/d41586-020-02009-w

What the reproduction number can and can’t tell us about managing COVID-19.

Taking action: The biomimetic synthesis of rhytidenone A was achieved by a Michael reaction/aldol/lactonization cascade in a single step from the proposed biosynthetic precursor rhytidenone F. Moreover, the highly cytotoxic rhytidenone F was shown to target PA28γ, leading to the accumulation of p53, which is an essential tumor suppressor in humans, ultimately initiating cellular apoptosis. Rhytidenone F may serve as a promising natural product lead for future anticancer drug development.

Abstract

The rhytidenone family comprises spirobisnaphthalene natural products isolated from the mangrove endophytic fungus Rhytidhysteron rufulum AS21B. The biomimetic synthesis of rhytidenone A was achieved by a Michael reaction/aldol/lactonization cascade in a single step from the proposed biosynthetic precursor rhytidenone F. Moreover, the mode of action of the highly cytotoxic rhytidenone F was investigated. The pulldown assay coupled with mass spectrometry analysis revealed the target protein PA28γ is covalently attached to rhytidenone F at the Cys92 residue. The interactions of rhytidenone F with PA28γ lead to the accumulation of p53, which is an essential tumor suppressor in humans. Consequently, the Fas‐dependent signaling pathway is activated to initiate cellular apoptosis. These studies have identified the first small‐molecule inhibitor targeting PA28γ, suggesting rhytidenone F may serve as a promising natural product lead for future anticancer drug development.

Stand and deliver: A coordinative dendrimer was rationally designed for cytosolic protein delivery. The synthesized polymer shows unprecedented efficiency in the cytosolic delivery of proteins and peptides with different isoelectric points. The bioactivities of the proteins are maintained after intracellular release.

Abstract

Cytosolic protein delivery is a prerequisite for the development of protein therapeutics that act on intracellular targets. Proteins are generally membrane‐impermeable and thus need a carrier such as a polymer to facilitate their internalization. However, the efficient binding of proteins with different isoelectric points to polymeric carriers is challenging. In this study, we designed a coordinative dendrimer to solve this problem. The dendrimers modified with dipicolylamine/zinc(II) complex were capable of binding proteins through a combination of ionic and coordination interactions. The best polymer efficiently delivered 30 cargo proteins and peptides into the cytosol, while maintaining their bioactivity after intracellular release. The removal or replacement of zinc ions in the polymer with other transition‐metal ions lead to significantly decreased efficiency in cytosolic protein delivery. This study provides a new strategy to develop robust and efficient polymers for cytosolic protein delivery.