Admixture of evolutionary rates across a butterfly hybrid zone

Hybridization is a major evolutionary force that can erode genetic differentiation between species, whereas reproductive isolation maintains such differentiation. In studying a hybrid zone between the swallowtail butterflies Papilio syfanius and Papilio maackii (Lepidoptera: Papilionidae), we made the unexpected discovery that genomic substitution rates are unequal between the parental species. This phenomenon creates a novel process in hybridization, where genomic regions most affected by gene flow evolve at similar rates between species, while genomic regions with strong reproductive isolation evolve at species-specific rates. Thus, hybridization mixes evolutionary rates in a way similar to its effect on genetic ancestry. Using coalescent theory, we show that the rate-mixing process provides distinct information about levels of gene flow across different parts of genomes, and the degree of rate-mixing can be predicted quantitatively from relative sequence divergence (FST ) between the hybridizing species at equilibrium. Overall, we demonstrate that reproductive isolation maintains not only genomic differentiation, but also the rate at which differentiation accumulates. Thus, asymmetric rates of evolution provide an additional signature of loci involved in reproductive isolation

Advanced fiber-shaped aqueous Zn ion battery integrated with strain sensor

Multifunctional batteries have attracted increasing attention, offering additional functionalities beyond the conventional batteries. Herein, we report a fiber-shaped Zn ion battery that not only acts as a high-performance power supply, but also provides sensing function to monitor human motions. Titanium fiber coated with α-MnO2 nanoflowers is exploited as cathode for fiber-shaped Zn ion battery, taking full advantage of such unique three-dimensional nanoflower structures of α-MnO2 with a large electrochemical active surface area and fast electrochemical reaction kinetics. Thus, the obtained fiber-shaped Zn ion battery shows high capacity of 280 mAh g-1 at 0.1 A g-1, resulting in a notable energy density of 396 Wh kg-1, good stability (capacity retention of 80.6% after 300 cycles), and high flexibility. As a demonstration, an electronic watch and five LEDs are successfully driven by two fiber-shaped Zn ion batteries. Furthermore, the fiber-shaped Zn ion battery is integrated with a strain sensor based on the carbon nanotube/polydimethylsiloxane film, offering good sensitivity to monitor motions of different body parts, such as wrist, finger, elbow, and knee. This work provides insights into multifunctional battery applications for the next-generation wearable electronics.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)Nanyang Technological UniversityNational Research Foundation (NRF)Submitted/Accepted versionThis work was supported by the Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2019-T2-2-127 and MOE-T2EP50120-0002), A*STAR under AME IRG (A2083c0062), and the Singapore National Research Foundation Competitive Research Program (NRF-CRP18-2017-02). This work was supported by A*STAR under its IAF-ICP Programme I2001E0067 and the Schaeffler Hub for Advanced Research at NTU. This work was also supported by NTU-PSL Joint Lab collaboration

Stretchable fiber-shaped aqueous aluminum ion batteries

The emerging wearable electronics have significantly motivated the development of fiber-shaped batteries with excellent electrochemical performance, safety, and flexibility. Aluminum (Al) ion batteries are potential candidates due to their high natural abundance, three-electron-redox behavior, and low cost. However, the integration of Al ion battery into wearable electronics remains unexplored. Herein, a stretchable fiber-shaped aqueous Al ion battery is reported, which involves manganese hexacyanoferrate cathode, graphene oxide decorated MoO3 anode, and hydrogel electrolyte. The resulting fiber-shaped battery exhibits good stretching properties and cycling stability (91.6% over 100 cycles at 1 A cm−3). Moreover, by employing a rocking-chair energy storage mechanism, the fiber-shaped battery offers a high specific capacity of 42 mAh cm−3 at 0.5 A cm−3, corresponding to a high specific energy of 30.6 mWh cm−3. As a demonstration, the fiber-based Al ion batteries are integrated into wearable textiles to power LED light, demonstrating the feasibility in stretchable and wearable electronics. (Figure presented.).Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)Nanyang Technological UniversityNational Research Foundation (NRF)Published versionThis work was supported by the Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2019-T2-2-127 and MOE-T2EP50120-0002), A*STAR under AME IRG (A2083c0062), the Singapore Ministry of Education Academic Research Fund Tier 1 (MOE2019-T1-001-103 (RG 73/19) and MOE2019-T1-001-111 (RG90/19)) and the Singapore National Research Foundation Competitive Research Program (NRF-CRP18-2017-02). This work was partly supported by the Schaeffler Hub for Advanced Research at NTU, under the ASTAR IAF-ICP Programme ICP1900093. This work was also supported by Nanyang Technological University

Ultra-compact MXene fibers by continuous and controllable synergy of interfacial interactions and thermal drawing-induced stresses

Recent advances in MXene (Ti3C2Tx) fibers, prepared from electrically conductive and mechanically strong MXene nanosheets, address the increasing demand of emerging yet promising electrode materials for the development of textile-based devices and beyond. However, to reveal the full potential of MXene fibers, reaching a balance between electrical conductivity and mechanical property is still the fundamental challenge, mainly due to the difficulties to further compact the loose MXene nanosheets. In this work, we demonstrate a continuous and controllable route to fabricate ultra-compact MXene fibers with an in-situ generated protective layer via the synergy of interfacial interactions and thermal drawing-induced stresses. The resulting ultra-compact MXene fibers with high orientation and low porosity exhibit not only excellent tensile strength and ultra-high toughness, but also high electrical conductivity. Then, we construct meter-scale MXene textiles using these ultra-compact fibers to achieve high-performance electromagnetic interference shielding and personal thermal management, accompanied by the high mechanical durability and stability even after multiple washing cycles. The demonstrated generic strategy can be applied to a broad range of nanostructured materials to construct functional fibers for large-scale applications in both space and daily lives.Agency for Science, Technology and Research (A*STAR)Ministry of Education (MOE)Nanyang Technological UniversityNational Research Foundation (NRF)Published versionThis work was supported by the Singapore Ministry of Education Academic Research Fund Tier 2 (MOE2019-T2-2-127 and MOE-T2EP50120-0002, L.W.), A*STAR under AME IRG (A2083c0062, L.W.), and the Singapore National Research Foundation Competitive Research Program (NRF-CRP18-2017-02, L.W.). This work was supported by A*STAR under its IAF-ICP Programme I2001E0067 and the Schaeffler Hub for Advanced Research at NTU (L.W.). This work was also supported by NTU-PSL Joint Lab collaboration (L.W.). This work was partly supported by the National Science Fund for Distinguished Young Scholars (52125302, Q.F.C.), the National Key Research and Development Program of China (2021YFA0715703, Q.F.C.), the National Postdoctoral Program for Innovative Talents (BX2021025, T.Z.Z.), and Postdoctoral Science Foundation (2021M690005, T.Z.Z.