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As a compliment to several other publications that present and honor Rolf Huisgen's research achievements, the first part of this paper reveals the human side of this eminent chemist. From excerpts from many of his personal and professional writings, Huisgen's personality and philosophies of life are revealed. Also revealed is Huisgen functioning as a historian of chemistry. The second part of this paper examines the scientometrics of Huisgen's publication history. In the late 1950s and early 1960s, Huisgen's career experienced a major transition in terms of publication metrics and the influence these papers had on the organic chemistry community. This was the result of his research into 1,3‐dipolar cycloadditions. Citations to his scientific contributions are well spread over many of his papers, demonstrating his constant work and the building up of a research topic, which continued after his official retirement in 1988. In fact, 17 % of his more than 600 publications appeared after 1988. The majority of Huisgen's papers were co‐authored with his many graduate and postdoctoral students. Consistent with the trend of that era, Huisgen was the sole author of most of his Review articles, and not just those of his many plenary lectures, and it is those Review articles that proved to be his most cited publications. This demonstrates the power and influence of Review articles—secondary sources, in the vocabulary of historians and sociologists of science. In those Review articles, Huisgen principally described the state of the art of 1,3‐dipolar cycloadditions—his golden offspring. [ABSTRACT FROM AUTHOR]

The recent outbreaks of Zika virus (ZIKV) infection represent a public health challenge. Rapid, cost‐effective, and reliable diagnostic tools for ZIKV detection at the point of care (POC) are highly desirable, especially for resource‐limited nations. To address the need, we have developed an integrated device to achieve sample‐to‐answer ZIKV detection. The device features innovative ball‐based valves enabling the storage and sequential delivery of reagents for virus lysis and a paper‐based unit for RNA enrichment and purification. The paper unit is placed in a commercially available coffee mug that provides a constant temperature for reverse transcription loop‐mediated isothermal amplification (RT‐LAMP), followed by colorimetric detection by naked eye or a cellphone camera. Using the device, we demonstrated the reproducible detection of ZIKV in human urine and saliva samples. POC Zika detection: A valve‐enabled lysis, paper‐based RNA enrichment, and RNA amplification device (VLEAD) is designed for sample‐to‐answer Zika virus detection. RNA is enriched with VLEAD in 25 min. A colorimetric signal is generated with SYBR Green dye and a blue LED flashlight after 25 min of reverse transcription loop‐mediated amplification (RT‐LAMP). [ABSTRACT FROM AUTHOR]

Flexible non-metal oxygen electrodes fabricated from phosphorus-doped graphitic carbon nitride nano-flowers directly grown on carbon-fiber paper exhibit high activity and stability in reversibly catalyzing oxygen reduction and evolution reactions, which is a result of N, P dual action, enhanced mass/charge transfer, and high active surface area. The performance is comparable to that of the state-of-the-art transition-metal, noble-metal, and non-metal catalysts. Remarkably, the flexible nature of these oxygen electrodes allows their use in folded and rolled-up forms, and directly as cathodes in Zn-air batteries, featuring low charge/discharge overpotential and long lifetime. [ABSTRACT FROM AUTHOR]

φ29 DNA polymerase (Polφ29) is capable of synthesizing long‐chain single‐stranded (ss) DNA molecules by copying the sequence of a small ss circular DNA template (ssCDT) in a process known as rolling circle amplification (RCA). The use of a ssCDT in RCA, however, comes with a key drawback: the rate of DNA synthesis is significantly reduced. We hypothesize that this issue can be overcome using a very long linear ssDNA template with a repeating sequence. To test this idea, we engineered a DNA assembly, which we denote "micrometer‐sized DNA track" (μDT). This μDT, with an average length of ≈13.5 μm, is made of a long chain DNA with a primer‐binding domain at its 3′ end and ≈1000 repeating sequence units at its 5′ end, each carrying a DNA anchor. We find that Polφ29 copies μDT at a speed ≈5‐time faster than it does a related ssCDT. We use this to design a simple all‐in‐one printed paper device for rapid and sensitive detection of microRNA let‐7. This paper sensor is capable of detecting 1 pM let‐7a in 10 minutes. [ABSTRACT FROM AUTHOR]

In this contribution, a unique donor‐acceptor conjugated organic‐small‐molecule photothermal material, namely GDPA‐QCN, is presented. Bulky dendritic triphenylamine (GDPA) was grafted onto quinoxaline‐6,7‐dicarbonitrile (QCN) with a phenyl ring as a bridge to form an "umbrella" architecture. Benefited from the particular molecular structure, in solid state, GDPA‐QCN molecules adopted a loose packing mode due to the steric effect of "umbrella head" dendritic triphenylamine and flexible molecular structure feature, which allows efficient intramolecular motions and consequently elevates energy dissipation by taking the pathway of thermal deactivation within broad absorption range. The GDPA‐QCN solid has high solar‐thermal conversion efficiency with an absorption range from 300 to 1100 nm, which can promote superior water purification and electricity generation performance. [ABSTRACT FROM AUTHOR]

Research data management (RDM) is needed to assist experimental advances and data collection in the chemical sciences. Many funders require RDM because experiments are often paid for by taxpayers and the resulting data should be deposited sustainably for posterity. However, paper notebooks are still common in laboratories and research data is often stored in proprietary and/or dead‐end file formats without experimental context. Data must mature beyond a mere supplement to a research paper. Electronic lab notebooks (ELN) and laboratory information management systems (LIMS) allow researchers to manage data better and they simplify research and publication. Thus, an agreement is needed on minimum information standards for data handling to support structured approaches to data reporting. As digitalization becomes part of curricular teaching, future generations of digital native chemists will embrace RDM and ELN as an organic part of their research. [ABSTRACT FROM AUTHOR]

Detecting antibodies in blood is as simple as it can get. In their Communication on page 15369 ff., D. Citterio, M. Merkx et al. integrate antibody‐targeting bioluminescent sensing proteins and other essential assay components into a microfluidic paper‐based analytical device. A drop of blood, a digital camera, and twenty minutes are all that is required to detect the presence and the concentration of multiple antibodies in whole blood based on the color of the emitted light. [ABSTRACT FROM AUTHOR]

A photo‐annealing approach was developed for building functional polymer layers on paper. In their Communication on page 4465 ff., Y. Wang and co‐workers show that conducting polyaniline with the ability to undergo photothermal conversion can be annealed by near‐infrared light. The porous structure is retained in the annealed polymer but it becomes insulating and hydrophobic. The asymmetric paper functions as a “water diode” and selective photo‐annealing produces patterned conductive arrays. [ABSTRACT FROM AUTHOR]

A piece of paper that is impregnated with multi‐walled or single‐walled carbon nanotubes generates ions from diverse analytes at voltages as low as 3 V, as T. Pradeep et al. show in their Communication on page 5936 ff. This miniaturized ion source is held in front of a mass‐spectrometer inlet to collect the mass spectrum. Common pesticides from the surface of an orange, active molecules from tablets, and a variety of analytes, such as amino acids, can been characterized. [ABSTRACT FROM AUTHOR]

We introduce an NAD(P)H‐sensitive polymer dot (Pdot) biosensor for point‐of‐care monitoring of metabolites. The Pdot is combined with a metabolite‐specific NAD(P)H‐dependent enzyme that catalyzes the oxidation of the metabolite, generating NAD(P)H. Upon UV illumination, the NAD(P)H quenches the fluorescence emission of Pdot at 627 nm via electron transfer, and also fluoresces at 458 nm, resulting in a shift from red to blue emission at higher NAD(P)H concentrations. Metabolite concentration is quantified ratiometrically‐based on the ratio of blue‐to‐red channel emission intensities, with a digital camera‐with high sensitivity and specificity. We demonstrate phenylalanine biosensing in human plasma for a phenylketonuria screening test, quantifying several other disease‐related metabolites (lactate, glucose, glutamate, and β‐hydroxybutyrate), and a paper‐based assay with smartphore imaging for point‐of‐care use. [ABSTRACT FROM AUTHOR]

Long‐lived afterglow room‐temperature phosphorescence (RTP) from natural phenolics has seldom been reported yet this is essential for the development of sustainable afterglow RTP materials. With this research, we have prepared sustainable afterglow RTP materials (GA@SA) with a lifetime of up to ≈934.7 ms by embedding gallic acid (GA) within a Ca2+‐crosslinked sodium alginate (SA) matrix. Theoretical simulations indicate that the restricted carbonyl moieties of the GA and H‐type aggregates of GA in a SA matrix promoted the spin orbit coupling (SOC) of GA and induced afterglow emission. Moreover, afterglow RTP emission could be produced by embedding different types of natural phenolics such as, tannic acid, caffeic acid and chlorogenic acid into Ca2+‐crosslinked networks of SA. As an illustration of potential applications, GA@SA was used to prepare anti‐counterfeit afterglow clothing and paper. This work provides an innovative method for the activation of long‐lived afterglow RTP from sustainable phenolics. [ABSTRACT FROM AUTHOR]

The silk road: By employing silk fibroin as a binder between graphene oxide films and aluminum foil for a facile, highly localized reduction process, conductive paper is reinvented. The flexible, robust biographene papers have high toughness and electrical conductivity. This electrochemical written‐in approach is readily applicable for the fabrication of conductive patterned papers (see picture) with complex circuitries. [ABSTRACT FROM AUTHOR]

Wearable electronics require highly conductive fibrous materials, which can now be fabricated at room temperature. In their Communication on page 7718 ff., H. M. Lee, S. H. Ko, and co‐workers demonstrate that cotton or paper fibers can be impregnated and coated with Al atoms from the precursor Al{O(C4H9)2}. The fibrous materials exhibit excellent electrical conductivity, as well as enduring mechanical strength, which is indicative of their potential applications for flexible and wearable electronics. [ABSTRACT FROM AUTHOR]

The combination of electrogenerated chemiluminescence (ECL) and aptamer‐gated indicator delivering (gAID) magnetic mesoporous silica nanoparticles embedded into glass fibre paper functionalised with poly(ethyleneglycol) and N‐(3‐triethoxysilylpropyl)diethanolamine allowed the development of a rapid test that detects penicillin directly in diluted milk down to 50±9 ppt in <5 min. Covalent attachment of the aptamer "cap" to the silica scaffold enabled pore closure through non‐covalent electrostatic interactions with surface amino groups, while binding of penicillin led to a folding‐up of the aptamer thus releasing the ECL reporter Ru(bpy)32+ previously loaded into the material and letting it be detected after lateral flow by a smartphone camera upon electrochemical excitation with a screen printed electrode inserted into a 3D‐printed holder. The approach is simple, generic and presents advantages with respect to sensitivity, measurement uncertainty and robustness compared with conventional fluorescence or electrochemical detection, especially for point‐of‐need analyses of challenging matrices and analytes at ultra‐trace levels. [ABSTRACT FROM AUTHOR]

Aliphatic polycarbonates (aPCs) have become increasingly popular as functional materials due to their biocompatibility and capacity for on‐demand degradation. Advances in polymerization techniques and the introduction of new functional monomers have expanded the library of aPCs available, offering a diverse range of chemical compositions and structures. To accommodate the emerging requirements of new applications in biomedical and energy‐related fields, various manufacturing techniques have been adopted for processing aPC‐based materials. However, a summary of these techniques has yet to be conducted. The aim of this paper is to enrich the toolbox available to researchers, enabling them to select the most suitable technique for their materials. In this paper, a concise review of the recent progress in processing techniques, including controlled self‐assembly, electrospinning, additive manufacturing, and other techniques, is presented. We also highlight the specific challenges and opportunities for the sustainable growth of this research area and the successful integration of aPCs in industrial applications. [ABSTRACT FROM AUTHOR]

Between 1910 and 1947, Robert Robinson (primarily), among others, published numerous proposed structures for strychnine. Robinson published 17 of his strychnine papers with his doctoral advisor William Henry Perkin, Jr. though all but two appeared after Robinson had taken his first permanent academic position. This Essay analyzes 20 key publications leading up to Robinson's (correct, then incorrect, then correct again though not definitively) proposal and Woodward's assignment of the actual structure of strychnine. We subjected the assignment of the strychnine structure to a modern computational quantum chemistry workflow. By computing, with density functional theory, 1H and 13C NMR chemical shifts for the literature‐proposed strychnine structures, we were able to rule out most incorrect structures. 13C NMR predictions were better at this, but 1H NMR chemical shifts were helpful. A comparison is made between the consequences of publishing erroneous ideas in the first half of the 20th century and doing so in the 21st century. [ABSTRACT FROM AUTHOR]

Developing self‐oscillating soft actuators that enable autonomous, continuous, and directional locomotion is significant in biomimetic soft robotics fields, but remains great challenging. Here, an untethered soft photoactuators based on covalently‐bridged black phosphorus‐carbon nanotubes heterostructure with self‐oscillation and phototactic locomotion under constant light irradiation is designed. Owing to the good photothermal effect of black phosphorus heterostructure and thermal deformation of the actuator components, the new actuator assembled by heterostructured black phosphorus, polymer and paper produces light‐driven reversible deformation with fast and large response. By using this actuator as mechanical power and designing a robot configuration with self‐feedback loop to generate self‐oscillation, an inchworm‐like actuator that can crawl autonomously towards the light source is constructed. Moreover, due to the anisotropy and tailorability of the actuator, an artificial crab robot that can simulate the sideways locomotion of crabs and simultaneously change color under light irradiation is also realized. [ABSTRACT FROM AUTHOR]

Protein biomarkers often exist as degradation fragments in biological samples, and affinity agents derived using a purified protein may not recognize them, limiting their value for clinical diagnosis. Herein, we present a method to overcome this issue, by selecting aptamers against a degraded form of the toxin B protein, which is a marker for diagnosing toxigenic Clostridium difficile infections. This approach has led to isolation of a DNA aptamer that recognizes degraded toxin B, fresh toxin B, and toxin B spiked into human stool samples. DNA aptamers selected using intact recombinant toxin B failed to recognize degraded toxin B, which is the form present in stored stool samples. Using this new aptamer, we produced a simple paper‐based analytical device for colorimetric detection of toxin B in stool samples, or in the NAP1 strain of Clostridium difficile. The combined aptamer‐selection and paper‐sensing strategy can expand the practical utility of DNA aptamers in clinical diagnosis. [ABSTRACT FROM AUTHOR]

Organic ultralong room temperature phosphorescence (OURTP) materials with photophysical properties sensitive to external stimulus are highly attractive for advanced applications. However, most OURTP molecules are in crystal and OURTP materials with good practicability and stimulus‐responsive character are hard to be achieved. Here, we report, for the first time, the highly efficient, ultralong‐lived and deep‐blue OURTP materials by simply doping boron phosphor into cyanuric acid host. Host–guest OURTP composites with abundant and tunable H‐bond network are highly stable in air with ultralong lifetime of 5.08 s at room temperature. They are sensitive to water, which can strength the H‐bond network to significantly enhance OURTP quantum yield from 16.1 % to 37.6 %. Anti‐counterfeiting paper was easily prepared for water‐jet printing; the jet‐printed high‐resolution OURTP patterns can be easily erased by solvent fuming for another printing/erasing cycle with high reversibility. [ABSTRACT FROM AUTHOR]

Carbon-based transition-metal oxides are considered as an appropriate anode material candidate for lithium-ion batteries. Herein, a simple and scalable dry production process is developed to produce carbon-encapsulated 3D net-like FeO x/C materials. The process is simply associated with the pyrolysis of a solid carbon source, such as filter paper, adsorbed with ferrite nitrate. The carbon derived from filter paper induces a carbothermal reduction to form metallic Fe, the addition of carbon and iron increase the conductivity of this material. As expected, this 3D net-like FeO x/C composite delivers an excellent charge capacity of 851.3 mAh g−1 after 50 cycles at 0.2 A g−1 as well as high stability and rate performance of 714.7 mAh g−1 after 300 cycles at 1 A g−1. Superior performance, harmlessness, low costs, and high yield may greatly stimulate the practical application of the products as anode materials in lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Because the TIM molecular weight was somewhat greater than that of PER and the two proteins associate in a yeast two hybrid assay,[42] TIM was an excellent candidate for the PER partner protein we had identified in fly head extracts. This fear was not entirely unfounded as almost 25 years had passed between the publication of Konopka and Benzer on I period i and these Young lab publications on the second I Drosophila i clock gene I timeless i ( I tim i ). Keywords: circadian rhythm; Nobel lecture; period protein EN circadian rhythm Nobel lecture period protein 8650 8666 17 04/03/21 20210412 NES 210412 Circadian rhythms are present in most if not all animals, plants, and even photosynthetic cyanobacteria. The data in this paper also indicated that the I per i SP I S i sp protein is a hypomorph (has decreased function) rather than a hypermorph, with an increase in gene/protein activity as originally postulated by Konopka and Benzer.[11] The Young lab identified all 3 Konopka and Benzer mutations and also showed that more copies of I period i transgenes led to shorter periods.[29] At the risk of making a slight tangent to discuss much more recent data, we now have a quite sophisticated view of at least part of the PER molecular cycle, and these data underscore the hypomorphic or loss-of-function character of the I per i SP I S i sp protein. Remarkably and consistent with the original hypothesis of Konopka that I per i SP I 01 i sp is a null mutant with no biological activity, this mutation creates a stop codon; there is therefore no wild-type PER encoded and perhaps no protein at all. [Extracted from the article]

Transition‐metal phosphides have stimulated great interest as catalysts to drive the hydrogen evolution reaction (HER), but their use as bifunctional catalytic electrodes that enable efficient neutral‐pH water splitting has rarely been achieved. Herein, we report the synthesis of ternary Ni0.1Co0.9P porous nanosheets onto conductive carbon fiber paper that can efficiently and robustly catalyze both the HER and water oxidation in 1 m phosphate buffer (PBS; pH 7) electrolyte under ambient conditions. A water electrolysis cell comprising the Ni0.1Co0.9P electrodes demonstrates remarkable activity and stability for the electrochemical splitting of neutral‐pH water. We attribute this performance to the new ternary Ni0.1Co0.9P structure with porous surfaces and favorable electronic states resulting from the synergistic interplay between nickel and cobalt. Ternary metal phosphides hold promise as efficient and low‐cost catalysts for neutral‐pH water splitting devices. Sheets and paper: Ternary Ni0.1Co0.9P porous nanosheets anchored onto conductive carbon fiber paper, can be used as a bifunctional catalytic material for driving both water reduction and oxidation reactions efficiently in neutral‐pH electrolyte under ambient conditions. [ABSTRACT FROM AUTHOR]

The Na–K alloy is a liquid at 25 °C over a large compositional range. The liquid alloy is also immiscible in the organic‐liquid electrolytes of an alkali‐ion rechargeable battery, providing dendrite‐free liquid alkali‐metal batteries with a liquid–liquid anode‐electrolyte interface at room temperature. The two liquids are each immobilized in a porous matrix. In previous work, the porous matrix used to immobilize the alloy was a carbon paper that is wet by the alloy at 420 °C; the alloy remains in the paper at room temperature. Here we report a room‐temperature vacuum infiltration of the alloy into a porous Cu or Al membrane and a reversible stripping/plating of the liquid alloy with the immobilized organic‐liquid electrolyte; no self‐diacharge is observed since the liquid Na–K does not dissolve into the liquid carbonate electrolytes. The preparation and stripping/plating of the liquid alkali‐metal anode can both now be done safely at room temperature. As an alternative to the high‐temperature Na–S battery with a dendrite‐free molten sodium anode, a room‐temperature liquid alkali‐metal battery with a liquid Na‐K anode and a liquid organic electrolyte is proposed. The liquid Na–K anode membranes can be prepared, used, and recycled at room temperature. [ABSTRACT FROM AUTHOR]

The artificial microenvironments inside coordination cages have gained significant attention for performing enzyme‐like catalytic reactions by facilitating the formation of labile and complex molecules through a "ship‐in‐a‐bottle" approach. Despite many fascinating examples, this approach remains scarcely explored in the context of synthesizing metallic clusters such as polyoxometalates (POMs). The development of innovative approaches to control and influence the speciation of POMs in aqueous solutions would greatly advance their applicability and could ultimately lead to the formation of elusive clusters that cannot be synthesized by using traditional methods. In this study, we employ host–guest stabilization within a coordination cage to enable a novel cavity‐directed synthesis of labile POMs in aqueous solutions under mild conditions. The elusive Lindqvist [M6O19]2− (M=Mo or W) POMs were successfully synthesized at room temperature via the condensation of molybdate or tungstate building blocks within the confined cavity of a robust and water‐soluble Pt6L4(NO3)12 coordination cage. Importantly, the encapsulation of these POMs enhances their stability in water, rendering them efficient catalysts for environmentally friendly and selective sulfoxidation reactions using H2O2 as a green oxidant in a pure aqueous medium. The approach developed in this paper offers a means to synthesize and stabilize the otherwise unstable metal‐oxo clusters in water, which can broaden the scope of their applications. [ABSTRACT FROM AUTHOR]

Two‐dimensional (2D) layered materials demonstrate prominent advantage in regulating lithium plating/stripping behavior by confining lithium diffusion/plating within interlayer gaps. However, achieving effective interlayer confined lithium diffusion/plating without compromising the stability of bulk‐structural and the solid electrolyte interphase (SEI) remains a considerable challenge. This paper presents an electrochemical scissor and lithium zipper‐driven protocol for realizing interlayer confined lithium plating with pretty‐low strain and volume change. In this protocol, lithium serves as a "zipper" to reunite the adjacent MXene back to MAX‐like phase to markedly enhance the structural stability, and a lithium halide‐rich SEI is formed by electrochemically removing the terminals of halogenated MXenes to maintain the stability and rapid lithium ions diffusion of SEI. When the Ti3C2I2 serves as the host for lithium plating, the average coulomb efficiency exceeds 97.0 % after 320 lithium plating/stripping cycles in conventional ester electrolyte. Furthermore, a full cell comprising of LiNi0.8Mn0.1Co0.1O2 and Ti3C2I2@Li exhibits a capacity retention rate of 73.4 % after 200 cycles even under high cathode mass‐loading (20 mg cm−2) and a low negative/positive capacity ratio of 1.4. Our findings advance the understanding of interlayer confined lithium plating in 2D layered materials and provide a new direction in regulating lithium and other metal plating/stripping behaviors. [ABSTRACT FROM AUTHOR]

Machine learning is increasingly integrated into chemistry research by guiding experimental procedures, correlating structure and function, interpreting large experimental datasets, to distill scientific insights that might be challenging with traditional methods. Such applications, however, largely focus on gaining insights via big data and/or big computation, while neglecting the valuable chemical prior knowledge dwelling in chemists' minds. In this paper, we introduce an Electrochemistry‐Informed Neural Network (ECINN) by explicitly embedding electrochemistry priors including the Butler–Volmer (BV), Nernst and diffusion equations on the backbone of neural networks for multi‐task discovery of electrochemistry parameters. We applied the ECINN to voltammetry experiments of Fe2+/Fe3+ ${{\rm F}{{\rm e}}^{2+}/{\rm F}{{\rm e}}^{3+}}$ and RuNH362+/RuNH363+ ${{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{2+{\rm \ }}/{\rm R}{\rm u}{\left({\rm N}{{\rm H}}_{3}\right)}_{6}^{3+{\rm \ }}}$ redox couples to discover electrode kinetics and mass transport parameters. Notably, ECINN seamlessly integrated mass transport with BV to analyze the entire voltammogram to infer transfer coefficients directly, so offering a new approach to Tafel analysis by outdating various mass transport correction methods. In addition, ECINN can help discover the nature of electron transfer and is shown to refute incorrect physics if imposed. This work encourages chemists to embed their domain knowledge into machine learning models to start a new paradigm of chemistry‐informed machine learning for better accountability, interpretability, and generalization. [ABSTRACT FROM AUTHOR]

Benzo‐fused nitrogen heterocycles are common features of bioactive molecules, and the enantioselective synthesis of their substituted analogues is an important goal. In this paper we demonstrate a practical and mechanistically intriguing approach to the enantioselective synthesis of 1‐arylbenzazepines and their analogues. The reaction sequence starts with an asymmetric migratory ring expansion of indoline, tetrahydroquinoline, or tetrahydrobenzazepine ureas on treatment with a chiral lithium amide base. Treatment of the ring‐expanded ureas with acid triggers a two‐atom ring contraction—an 'azatropic shift' in which one urea nitrogen displaces the other—with almost complete retention of stereochemistry. Aminolysis of the urea products provides enantioenriched 1‐aryl‐tetrahydrobenzazepine derivatives and their congeners, including an analogue of an intermediate in the synthesis of the drug solifenacin. Deuteration, in situ IR, and DFT studies provide evidence for the mechanisms of the reaction steps. [ABSTRACT FROM AUTHOR]

In this paper, we proposed a heteroatom substitution strategy (HSS) in the δ‐valerolactone (VL) system to modulate thermodynamics toward chemically recyclable polyesters. Three VL‐based monomers containing different heteroatoms (M1 (N), M2 (S), and M3 (O)), instead of C‐5 carbon, were designed and synthesized to verify our proposed HSS. All three monomers undergo organocatalytic living/controlled ROP and controllable depolymerization. Impressively, the resulting P(M1) achieved over 99 % monomer recovery under both mild solution depolymerization and high vacuum pyrolysis conditions without any side reactions, and the recycled monomers can be polymerized again forming new polymers. The systematic study of the relationship between heteroatom substitution and recyclability shows that introducing heteroatoms does change the thermodynamics of the monomers (ΔHpo, ΔSpo and Tc values), thereby adjusting the polymerizability and depolymerizability. DFT calculations found that the introduction of heteroatoms adjusts the ring strain by changing the angular strain of the monomers, and the order of their angular strain (M2>M1>M3) is consistent with the order of the experimentally obtained enthalpy change. Notably, the one‐pot/one‐step copolymerization of two of each of the three monomers enables the synthesis of sequence‐controlled copolymers from gradient to random to block structures, by simply switching the copolymerization temperature. [ABSTRACT FROM AUTHOR]

The paper aims to elucidate the final stages in the biosynthesis of the [2Fe]H active site of the [FeFe]‐hydrogenases. The recently hypothesized intermediate [Fe2(SCH2NH2)2(CN)2(CO)4]2− ([1]2−) was prepared by a multistep route from [Fe2(S2)(CN)(CO)5]−. The following synthetic intermediates were characterized in order: [Fe2(SCH2NHFmoc)2(CNBEt3)(CO)5]−, [Fe2(SCH2NHFmoc)2(CN)−(CO)5]−, and [Fe2(SCH2NHFmoc)2(CN)2(CO)4]2−, where Fmoc is fluorenylmethoxycarbonyl). Derivatives of these anions include [K(18‐crown‐6)]+, PPh4+ and PPN+ salts as well as the 13CD2‐isotopologues. These Fe2 species exist as a mixture of two isomers attributed to diequatorial (ee) and axial‐equatorial (ae) stereochemistry at sulfur. In vitro experiments demonstrate that [1]2− maturates HydA1 in the presence of HydF and a cocktail of reagents. HydA1 can also be maturated using a highly simplified cocktail, omitting HydF and other proteins. This result is consistent with HydA1 participating in the maturation process and refines the roles of HydF. [ABSTRACT FROM AUTHOR]

An Au‐on‐Au tip sensor is developed for the detection of Salmonella typhimurium (Salmonella), using a new synthetic nucleic acid probe (NAP) as a linker for the immobilization of a DNA‐conjugated Au nanoparticle (AuNP) onto a DNA‐attached thin Au layer inside a pipette tip. In the presence of Salmonella, RNase H2 from Salmonella (STH2) cleaves the NAP and the freed DNA‐conjugated AuNP can be visually detected by a paper strip. This portable biosensor does not require any electronic, electrochemical or optical equipment. It delivers a detection limit of 3.2×103 CFU mL−1 for Salmonella in 1 h without cell‐culturing or signal amplification and does not show cross‐reactivity with several control bacteria. Further, the sensor reliably detects Salmonella spiked in food samples, such as ground beef and chicken, milk, and eggs. The sensor can be reused and is stable at ambient temperature, showing its potential as a point‐of‐need device for the prevention of food poisoning by Salmonella. [ABSTRACT FROM AUTHOR]

Developing easily accessible descriptors is crucial but challenging to rationally design single‐atom catalysts (SACs). This paper describes a simple and interpretable activity descriptor, which is easily obtained from the atomic databases. The defined descriptor proves to accelerate high‐throughput screening of more than 700 graphene‐based SACs without computations, universal for 3–5d transition metals and C/N/P/B/O‐based coordination environments. Meanwhile, the analytical formula of this descriptor reveals the structure–activity relationship at the molecular orbital level. Using electrochemical nitrogen reduction as an example, this descriptor's guidance role has been experimentally validated by 13 previous reports as well as our synthesized 4 SACs. Orderly combining machine learning with physical insights, this work provides a new generalized strategy for low‐cost high‐throughput screening while comprehensive understanding the structure‐mechanism‐activity relationship. [ABSTRACT FROM AUTHOR]