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Constructing a crystalline-amorphous hybrid structure is an effective strategy to overcome the conflict between the strength and toughness of materials. However, achieving such a material structure often involves complex, energy-intensive processing. Here, we leverage the natural wood featuring coexisting crystalline and amorphous regions to achieve superstrong and ultratough wood paper (W-paper) via a dual-phase nanostructure regulation strategy. After partially removing amorphous hemicellulose and eliminating most lignin, the treated wood can self-densify through an energy-efficient air drying, resulting in a W-paper with high tensile strength, toughness, and folding endurance. Coarse-grained molecular dynamics simulations reveal the underlying deformation mechanism of the crystalline and amorphous regions inside cell walls and the failure mechanism of the W-paper under tension. Life cycle assessment reveals that W-paper shows a lower environmental impact than commercial paper and common plastics. This dual-phase nanostructure regulation based on natural wood may provide valuable insights for developing high-performance and sustainable film materials. [ABSTRACT FROM AUTHOR]

Constructing a crystalline-amorphous hybrid structure is an effective strategy to overcome the conflict between the strength and toughness of materials. However, achieving such a material structure often involves complex, energy-intensive processing. Here, we leverage the natural wood featuring coexisting crystalline and amorphous regions to achieve superstrong and ultratough wood paper (W-paper) via a dual-phase nanostructure regulation strategy. After partially removing amorphous hemicellulose and eliminating most lignin, the treated wood can self-densify through an energy-efficient air drying, resulting in a W-paper with high tensile strength, toughness, and folding endurance. Coarse-grained molecular dynamics simulations reveal the underlying deformation mechanism of the crystalline and amorphous regions inside cell walls and the failure mechanism of the W-paper under tension. Life cycle assessment reveals that W-paper shows a lower environmental impact than commercial paper and common plastics. This dual-phase nanostructure regulation based on natural wood may provide valuable insights for developing high-performance and sustainable film materials.

The article discusses controlling the duration information lasts on paper so that disappears as desired has crucial for information security. Topics include the information duration on the rewritable paper coated with the title compounds has easily tuned by changing the cation of the compounds; and the fidelity of the information visualization has additionally be used as a time stamp, and a missing anti-counterfeiting label signals.

Mechanically transformative electronic systems (TESs) built using gallium have emerged as an innovative class of electronics due to their ability to switch between rigid and flexible states, thus expanding the versatility of electronics. However, the challenges posed by gallium's high surface tension and low viscosity have substantially hindered manufacturability, limiting high-resolution patterning of TESs. To address this challenge, we introduce a stiffness-tunable gallium-copper composite ink capable of direct ink write printing of intricate TES circuits, offering high-resolution (~50 micrometers) patterning, high conductivity, and bidirectional soft-rigid convertibility. These features enable transformative bioelectronics with design complexity akin to traditional printed circuit boards. These TESs maintain rigidity at room temperature for easy handling but soften and conform to curvilinear tissue surfaces at body temperature, adapting to dynamic tissue deformations. The proposed ink with direct ink write printing makes TES manufacturing simple and versatile, opening possibilities in wearables, implantables, consumer electronics, and robotics. [ABSTRACT FROM AUTHOR]

The article presents a study which explores how wearable plasmonic paper–based microfluidics for continuous sweat analysis. It mentions that wearable sweat sensors have the potential to provide clinically meaningful information associated with the health and disease states of individuals. It discusses that welld-defined flow characteristics of paper microfluidic devices enable accurate quantification of sweat loss and sweat rate.

Photonic crystal (PC) patterns have shown wide applications in optical devices, information encryption, anticounterfeiting, etc. Unfortunately, it is still a great challenge to reconfigure the PC patterns once fabricated. Herein, a new strategy is presented to reconfigure self-recordable PC patterns by printing local patterns into the chameleon-inspired PC papers using the phase change material (PCM) as ink and then erasing the patterns in ethanol. Multicolor and high-resolution (25 and 75  μ m for dot and lines, respectively) patterns can be efficiently and repeatedly reconfigured. In addition, the photonic patterns based on the PC paper and PCM combinations are gifted with mechanochromic characteristics and can show programmable and reversible color change under pressure. The high melting point of the ink, nonclosely packed structures of the PC paper, and the similar solubility parameter of PC paper, PCM, and ethanol are the keys for all these characteristics. This work offers a simple, flexible, efficient way to reconfigure PC patterns with mechanochromic properties and could open up exciting applications for novel hand-operation-based anticounterfeiting and optical devices., Competing Interests: The authors declare that there is no conflict of interest regarding the publication of this article., (Copyright © 2022 Dongpeng Yang et al.)

The paper wasp Polistes atrimandibularis is an obligatory social parasite of another Polistes species, P. biglumis bimaculatus. To control the host nest, the parasite sequentially changes the composition of its chemical signature, the cuticular hydrocarbons, during the colonial cycle. Gas chromatography-mass spectrometry of the cuticular hydrocarbons at every stage of the cycle showed that the parasite can switch on and off an entire chemical family, namely, the unsaturated hydrocarbons. In this way the parasite can match the host signature at a critical moment of the colonial cycle., Having no worker caste and being incapable of nest building, P. atrirwndibularis is an obligatory social parasite. During the short 4-month summer colonial cycle of the host, a P. atrimandibularis [...]

Controlling the duration that information lasts on paper so that it disappears as desired is crucial for information security. However, this area is rarely studied. Here, we report [TEMA] 2 SbCl 5 ( 1 , TEMA + = methyltriethylammonium), [TEA] 2 SbCl 5 ( 2 , TEA + = tetraethylammonium), [TEBA] 2 SbCl 5 ( 3 , TEBA + = benzyltriethylammonium), and [Ph 4 P] 2 SbCl 5 ( 4 , Ph 4 P + = tetraphenylphosphonium) with structure-dependent reversible photoluminescent switching induced by the absorption and thermal release of small guest molecules including H 2 O, methanol, and ethylene glycol. Comparing the structural disorder levels, bond lengths, and luminescent Stokes shifts of the compounds aided in understanding their selective absorption behavior. Our results indicated that the information duration on the rewritable paper coated with the title compounds is easily tuned by changing the cation of the compounds, the type of guest molecules, and laser heating power. Our study opens previously unidentified avenues for information security and extends the potential applications of rewritable paper., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

Lithium (Li) metal has been regarded as one of the most promising anode materials to meet the urgent requirements for the next-generation high-energy density batteries. However, the practical use of lithium metal anode is hindered by the uncontrolled growth of Li dendrites, resulting in poor cycling stability and severe safety issues. Herein, vertical graphene (VG) film grown on graphite paper (GP) as an all-carbon current collector was utilized to regulate the uniform Li nucleation and suppress the growth of dendrites. The high surface area VG grown on GP not only reduces the local current density to the uniform electric field but also allows fast ion transport to homogenize the ion gradients, thus regulating the Li deposition to suppress the dendrite growth. The Li deposition can be further guided with the lithiation reaction between graphite paper and Li metal, which helps to increase lithiophilicity and reduce the Li nucleation barrier as well as the overpotential. As a result, the VG film-based anode demonstrates a stable cycling performance at a current density higher than 5 mA cm -2 in half cells and a small hysteresis of 50 mV at 1 mA cm -2 in symmetric cells. This work provides an efficient strategy for the rational design of highly stable Li metal anodes., Competing Interests: The authors declare no conflict of interest regarding the publication of this article., (Copyright © 2020 Zhijia Huang et al.)

Bright, iridescent colors observed in nature are often caused by light interference within nanoscale periodic lattices, inspiring numerous strategies for coloration devoid of inorganic pigments. Here, we describe and characterize the septum of the Lunaria annua plant that generates large (multicentimeter), freestanding iridescent sheets, with distinctive silvery-white reflective appearance. This originates from the thin-film assembly of cellulose fibers in the cells of the septum that induce thin-film interference-like colors at the microscale, thus accounting for the structure's overall silvery-white reflectance at the macroscale. These cells further assemble into two thin layers, resulting in a mechanically robust, iridescent septum, which is also significantly light due to its high air porosity (>70%) arising from the cells' hollow-core structure. This combination of hierarchical structure comprising mechanical and optical function can inspire technological classes of devices and interfaces based on robust, light, and spectrally responsive natural substrates., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

A recent paper in Science Advances by Miller et al. concludes that Graduate Record Examinations (GREs) do not help predict whether physics graduate students will get Ph.D.'s. Here, I argue that the presented analyses reflect collider-like stratification bias, variance inflation by collinearity and range restriction, omission of parts of a needed correlation matrix, a peculiar choice of null hypothesis on subsamples, blurring the distinction between failure to reject a null and accepting a null, and an unusual procedure that inflates the confidence intervals in a figure. Release of results of a model that leaves out stratification by the rank of the graduate program would fix many of the problems., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).)

We demonstrate that the evolution of facial recognition in wasps is associated with specialized face-learning abilities. Polistes fuscatus can differentiate among normal wasp face images in rapidly and accurately than nonface images or manipulated faces. A close relative lacking facial recognition, Polistes metficus, however, lacks specialized face learning. Similar specializations for face learning are found in primates and other mammals, although P. fuscatus represents an independent evolution of specialization. Convergence toward face specialization in distant taxa as well as divergence among closely related taxa with different recognition behavior suggests that specialized cognition is surprisingly labile and may be adaptively shaped by species-specific selective pressures such as face recognition. [ABSTRACT FROM AUTHOR]

This paper shows that stacked sheets of paper preincubated with different biological reagents and skiving them into uniform test paper sheets allow mass manufacturing of multiplexed immunoassay devices and simultaneous detection of multiplex targets that can be read out by a barcode scanner. The thickness of one sheet of paper can form the width of a module for the barcode; when stacked, these sheets of paper can form a series of barcodes representing the targets, depending on the color contrast provided by a colored precipitate of an immunoassay. The uniform thickness of sheets of paper allows high-quality signal readout. The manufacturing method allows highly efficient fabrication of the materials and substrates for a straightforward assay of targets that range from drugs of abuse to biomarkers of blood-transmitted infections. In addition, as a novel alternative to the conventional point-of-care testing method, the paper-based barcode assay system can provide highly efficient, accurate, and objective diagnoses. [ABSTRACT FROM AUTHOR]

To learn the evolutionary trajectories of caste differentiation in eusocial species is a major goal of sociobiology. We present an explanatory framework for caste evolution in the eusocial wasp genus Polistes (Vespidae), which is a model system for insect eusocial evolution. We hypothesize that Polistes worker and gyne castes stern from two developmental pathways that characterized the bivoltine life cycle of a solitary ancestor. Through individual-based simulations, we show that our mechanistic framework can reproduce colony-level characteristics of Polistes and, thereby, that social castes can emerge from solitary regulatory pathways. Our explanatory framework illustrates, by specific example, a changed perspective for understanding insect social evolution., The essence of eusociality in Polistes wasps is the differentiation of female offspring into two castes: nonreproductive females that work in their natal colony and reproductive gynes that found colonies [...]

Even in the best of times, 95% of Jan Hendrik Schon's experiments fizzled out. It's the other 5% that made him one of nanotechnology's brightest stars and the envy of [...]

WHEN A TEAM OF RESEARCHERS PUBLISHED A paper in Cell in April 1986, (*) they probably expected to generate scientific controversy, for they were reporting results that challenged the conventional [...]

A new polyethylene paper may be marked on a hard surface with an ordinary oversize ball-point pen or dull pencil point. Where the paper is marked, a raised-line imprint appears on the same side of the paper as that used for writing. This imprint may be both felt and seen. Newly blinded and partially sighted persons are able to read ordinary Arabic letters and numerals after a few trials.