The latest research from Nature Materials February 2021

[Nature Materials]( [] Advertisement Optical spectroscopy with nanometer-scale spatial resolution Uncover the optical and electronic properties of new materials far below the diffraction limit. [To learn more see our Experiment Brief]( TABLE OF CONTENTS --------------------------------------------------------------- February 2021 Volume 20, Issue 2 [Current issue]( [Editorial](#_20_2-1) [News & Views](#_20_2-2) [Review Articles](#_20_2-3) [Letters](#_20_2-4) [Articles](#_20_2-5) [Why it Matters](#_20_2-6) Advertisement [APR]( [Give your paper to us and we'll give back to science]( Applied Physics Reviews (APR) has an Impact Factor of 17.054 and publishes original research and reviews. As a society publisher, we support the scientific and educational programs of the American Institute of Physics. Invest in the future of physical science research with APR. [Submit your research today]( Advertisement Buy first-class training for your research team Does your team need training on data or guidance on narrative tools? We're launching two more essential courses, delivered by expert Nature editors. [Find out more >>]( Advertisement [Communications Materials: Call for papers]( [Communications Materials]( is a selective open access, peer-reviewed journal publishing high-quality research, reviews and commentary in all areas of materials science. Learn about the benefits of submitting your research today. [Find out more >>]( [Communications Materials]( [] Editorial [ ] [The promise of organoids and embryoids p121]( doi:10.1038/s41563-021-00926-3 [] News & Views [ ] [Making large single crystals of 2D MOFs pp122 - 123]( Renhao Dong & Xinliang Feng doi:10.1038/s41563-020-00912-1 [ ] [Defined matrices bring IBD to 3D pp124 - 125]( Bauer L. LeSavage & Sarah C. Heilshorn doi:10.1038/s41563-020-00904-1 [ ] [How nano can fight the virus p126]( Philip Ball doi:10.1038/s41563-020-00916-x [ ] [Probing a mesoscopic elephant pp127 - 128]( Robert Stamps doi:10.1038/s41563-020-00915-y [ ] [Bioprinting better kidney organoids pp128 - 130]( Benjamin D. Humphreys doi:10.1038/s41563-020-00881-5 [ ] [Exfoliating large monolayers in liquids pp130 - 131]( Christopher A. Howard doi:10.1038/s41563-020-00907-y [] Review Articles [ ] [Stem-cell-based embryo models for fundamental research and translation pp132 - 144]( Jianping Fu, Aryeh Warmflash & Matthias P. Lutolf doi:10.1038/s41563-020-00829-9 This Review highlights the recent emergence of stem-cell-derived embryo models for the purpose of advancing our understanding of mammalian embryology as well as their potential uses in regenerative and reproductive medicine. [ ] [Rethinking organoid technology through bioengineering pp145 - 155]( Elena Garreta, Roger D. Kamm, Susana M. Chuva de Sousa Lopes, Madeline A. Lancaster, Ron Weiss et al. doi:10.1038/s41563-020-00804-4 This Review provides an overview of bioengineering technologies that can be harnessed to facilitate the culture, self-organization and functionality of human pluripotent stem cell-derived organoids. [ ] [Somatic cell-derived organoids as prototypes of human epithelial tissues and diseases pp156 - 169]( Masayuki Fujii & Toshiro Sato doi:10.1038/s41563-020-0754-0 This Review highlights approaches used to generate somatic cell-derived organoids for modelling epithelial tissue to understand disease progression and how they are employed in preclinical drug screening. [] Letters [ ] [AC Josephson effect between two superfluid time crystals pp171 - 174]( S. Autti, P. J. Heikkinen, J. T. Mäkinen, G. E. Volovik, V. V. Zavjalov et al. doi:10.1038/s41563-020-0780-y Two adjacent quantum time crystals implemented by two magnon condensates in the superfluid B-phase of helium-3 are observed to coherently exchange magnons as a manifestation of the AC Josephson effect, offering insights on the dynamics and interactions between these phases of matter. [ ] [Carbazole isomers induce ultralong organic phosphorescence pp175 - 180]( Chengjian Chen, Zhenguo Chi, Kok Chan Chong, Andrei S. Batsanov, Zhan Yang et al. doi:10.1038/s41563-020-0797-2 A carbazole isomer, typically present as an impurity in commercially produced carbazole batches, is shown to be responsible for the ultralong phosphorescence observed in these compounds and their derivatives. [] Articles [ ] [Printable two-dimensional superconducting monolayers pp181 - 187]( Jing Li, Peng Song, Jinpei Zhao, Kristina Vaklinova, Xiaoxu Zhao et al. doi:10.1038/s41563-020-00831-1 A mild electrochemical exfoliation method has been developed to obtain large-size two-dimensional superconductor monolayers with high crystallinity and production yield, which enables the easy fabrication of twisted van der Waals heterostructures and printed films. [ ] [Tuning spin excitations in magnetic films by confinement pp188 - 193]( Jonathan Pelliciari, Sangjae Lee, Keith Gilmore, Jiemin Li, Yanhong Gu et al. doi:10.1038/s41563-020-00878-0 The thickness dependence of the dispersion of spin waves in mesoscopic iron films is measured and found to be renormalized in the out-of-plane direction as the thickness is reduced. The results are captured by a Heisenberg model that accounts for the confinement in the out-of-plane direction through the loss of Fe bonds. [ ] [Local negative permittivity and topological phase transition in polar skyrmions pp194 - 201]( S. Das, Z. Hong, V. A. Stoica, M. A. P. Gonçalves, Y. T. Shao et al. doi:10.1038/s41563-020-00818-y Polar skyrmions are topologically protected structures that can exist in (PbTiO3)n/(SrTiO3)n superlattices. Here, it is shown that they have negative permittivity at the surface, and that they can undergo a reversible phase transition with large dielectric tunability under an electric field. [ ] [Towards chirality control of graphene nanoribbons embedded in hexagonal boron nitride pp202 - 207]( Hui Shan Wang, Lingxiu Chen, Kenan Elibol, Li He, Haomin Wang et al. doi:10.1038/s41563-020-00806-2 Oriented trenches are created in h-BN using different catalysts, and used as templates to grow seamlessly integrated armchair and zigzag graphene nanoribbons with chirality-dependent electrical and magnetic conductance properties. [ ] [Self-supported Pt–CoO networks combining high specific activity with high surface area for oxygen reduction pp208 - 213]( Gustav W. Sievers, Anders W. Jensen, Jonathan Quinson, Alessandro Zana, Francesco Bizzotto et al. doi:10.1038/s41563-020-0775-8 A high oxygen reduction reaction activity can usually be realized by increasing platinum specific activity at the expense of active surface area. Self-supported platinum–cobalt-oxide networks combining high activity and surface area now promise a stable fuel-cell operation. [ ] [Cation-disordered rocksalt-type high-entropy cathodes for Li-ion batteries pp214 - 221]( Zhengyan Lun, Bin Ouyang, Deok-Hwang Kwon, Yang Ha, Emily E. Foley et al. doi:10.1038/s41563-020-00816-0 High-entropy ceramics are solid solutions offering compositional flexibility and wide variety of applicability. High-entropy concepts are shown to lead to substantial performance improvement in cation-disordered rocksalt-type cathodes for Li-ion batteries. [ ] [Atomically precise single-crystal structures of electrically conducting 2D metal–organic frameworks pp222 - 228]( Jin-Hu Dou, Maxx Q. Arguilla, Yi Luo, Jian Li, Weizhe Zhang et al. doi:10.1038/s41563-020-00847-7 Two-dimensional MOFs can possess porosity and electrical conductivity but are difficult to grow as single crystals. Here, by balancing in-plane and out-of-plane interactions, single crystals of sizes up to 200 µm are grown, allowing in-plane transport measurements and atomic-resolution analysis. [ ] [Electrical bioadhesive interface for bioelectronics pp229 - 236]( Jue Deng, Hyunwoo Yuk, Jingjing Wu, Claudia E. Varela, Xiaoyu Chen et al. doi:10.1038/s41563-020-00814-2 A graphene nanocomposite hydrogel showing anisotropic swelling is used to realize an electrically conducting and removable bioadhesive that improves the mechanical and electrical integration of bioelectronics devices with wet dynamic tissues. [ ] [Mechanically robust lattices inspired by deep-sea glass sponges pp237 - 241]( Matheus C. Fernandes, Joanna Aizenberg, James C. Weaver & Katia Bertoldi doi:10.1038/s41563-020-0798-1 Computational analysis and mechanical testing demonstrate that the skeletal system of a marine sponge has, through the course of evolution, achieved a near-optimal resistance to buckling. [ ] [A bioinspired and hierarchically structured shape-memory material pp242 - 249]( Luca Cera, Grant M. Gonzalez, Qihan Liu, Suji Choi, Christophe O. Chantre et al. doi:10.1038/s41563-020-0789-2 Shear-aligned keratin protofibres are used to fabricate shape-memory fibres and three-dimensional scaffolds that respond to water. [ ] [ILC1 drive intestinal epithelial and matrix remodelling pp250 - 259]( Geraldine M. Jowett, Michael D. A. Norman, Tracy T. L. Yu, Patricia Rosell Arévalo, Dominique Hoogland et al. doi:10.1038/s41563-020-0783-8 Type-1 innate lymphoid cells have been shown to drive intestinal epithelial proliferation and extracellular matrix remodelling through TGF-β1 secretion, which could exacerbate inflammatory bowel disease comorbidities such as cancer and fibrosis. [ ] [Cellular extrusion bioprinting improves kidney organoid reproducibility and conformation pp260 - 271]( Kynan T. Lawlor, Jessica M. Vanslambrouck, J. William Higgins, Alison Chambon, Kristina Bishard et al. doi:10.1038/s41563-020-00853-9 Extrusion-based bioprinting has been shown to rapidly and reproducibly generate kidney organoids from a cell-only paste, with the number and maturation of functional units within the kidney tissue capable of being further improved by bioprinting tissue sheets. [] Why it Matters [ ] [Politics should listen to science, not hide behind it p272]( Carlo Rovelli doi:10.1038/s41563-020-00891-3 [nature events]( Natureevents is a fully searchable, multi-disciplinary database designed to maximise exposure for events organisers. The contents of the Natureevents Directory are now live. The digital version is available [here](. Find the latest scientific conferences, courses, meetings and symposia on [natureevents.com](. For event advertising opportunities across the Nature Publishing Group portfolio please contact natureevents@nature.com [More Nature Events]( This email has been sent to {EMAIL}. If you no longer wish to receive the email alerts from Nature Materials [click here to unsubscribe](. If you wish to discontinue all email services from Nature Research please [click here to unsubscribe](. Visit [Nature Support]( for answers to our most frequently asked questions. 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