Forces driving transposable element load variation during Arabidopsis range expansion.

Genetic load refers to the accumulated and potentially life-threatening deleterious mutations in populations. Understanding the mechanisms underlying genetic load variation of transposable element (TE) insertion, a major large-effect mutation, during range expansion is an intriguing question in biology. Here, we used 1,115 global natural accessions of Arabidopsis (Arabidopsis thaliana) to study the driving forces of TE load variation during its range expansion. TE load increased with range expansion, especially in the recently established Yangtze River basin population. Effective population size, which explains 62.0% of the variance in TE load, high transposition rate, and selective sweeps contributed to TE accumulation in the expanded populations. We genetically mapped and identified multiple candidate causal genes and TEs, and revealed the genetic architecture of TE load variation. Overall, this study reveals the variation in TE genetic load during Arabidopsis expansion and highlights the causes of TE load variation from the perspectives of both population genetics and quantitative genetics.

What Is the Real Origin of Single-Walled Carbon Nanotubes for the Performance Enhancement of Si-Based Anodes?

A large amount of lithium-ion storage in Si-based anodes promises high energy density yet also results in large volume expansion, causing impaired cyclability and conductivity. Instead of restricting pulverization of Si-based particles, herein, we disclose that single-walled carbon nanotubes (SWNTs) can take advantage of volume expansion and induce interfacial reactions that stabilize the pulverized Si-based clusters in situ. Operando Raman spectroscopy and density functional theory calculations reveal that the volume expansion by the lithiation of Si-based particles generates ∼14% tensile strains in SWNTs, which, in turn, strengthens the chemical interaction between Li and C. This chemomechanical coupling effect facilitates the transformation of sp2-C at the defect of SWNTs to Li-C bonds with sp3 hybridization, which also initiates the formation of new Si-C chemical bonds at the interface. Along with this process, SWNTs can also induce in situ reconstruction of the 3D architecture of the anode, forming mechanically strengthened networks with high electrical and ionic conductivities. As such, with the addition of only 1 wt % of SWNTs, graphite/SiOx composite anodes can deliver practical performance well surpassing that of commercial graphite anodes. These findings enrich our understanding of strain-induced interfacial reactions, providing a general principle for mitigating the degradation of alloying or conversion-reaction-based electrodes.

High-Rate and Selective C2H6-to-C2H4 Photodehydrogenation Enabled by Partially Oxidized Pdδ+ Species Anchored on ZnO Nanosheets under Mild Conditions.

Photocatalytic C2H6-to-C2H4 conversion is very promising, yet it remains a long-lasting challenge due to the high C-H bond dissociation energy of 420 kJ mol-1. Herein, partially oxidized Pdδ+ species anchored on ZnO nanosheets are designed to weaken the C-H bond by the electron interaction between Pdδ+ species and H atoms, with efforts to achieve high-rate and selective C2H6-to-C2H4 conversion. X-ray photoelectron spectra, Bader charge calculations, and electronic localization function demonstrate the presence of partially oxidized Pdδ+ sites, while quasi-in situ X-ray photoelectron spectra disclose the Pdδ+ sites initially adopt and then donate the photoexcited electrons for C2H6 dehydrogenation. In situ electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and trapping agent experiments verify C2H6 initially converts to CH3CH2OH via ·OH radicals, then dehydroxylates to CH3CH2· and finally to C2H4, accompanied by H2 production. Density-functional theory calculations elucidate that loading Pd site can lengthen the C-H bond of C2H6 from 1.10 to 1.12 Å, which favors the C-H bond breakage, affirmed by a lowered energy barrier of 0.04 eV. As a result, the optimized 5.87% Pd-ZnO nanosheets achieve a high C2H4 yield of 16.32 mmol g-1 with a 94.83% selectivity as well as a H2 yield of 14.49 mmol g-1 from C2H6 dehydrogenation in 4 h, outperforming all the previously reported photocatalysts under similar conditions.

Multi-dimensional cylindrical vector beam (de)multiplexing through cascaded wavelength- and polarization-sensitive metasurfaces.

Cylindrical vector beams (CVBs) exhibit great potential for multiplexing communication, owing to their mode orthogonality and compatibility with conventional wavelength multiplexing techniques. However, the practical application of CVB multiplexing communication faces challenges due to the lack of effective spatial polarization manipulation technologies for (de)multiplexing multi-dimensional physical dimensions of CVBs. Herein, we introduce a wavelength- and polarization-sensitive cascaded phase modulation strategy that utilizes multiple coaxial metasurfaces for multi-dimensional modulation of CVBs. By leveraging the spin-dependent phase modulation mechanism, these metasurfaces enable the independent transformation of the two orthogonal polarization components of CVB modes. Combined with the wavelength sensitivity of Fresnel diffraction in progressive phase modulation, this approach establishes a high-dimensional mapping relationship among CVB modes, wavelengths, spatial positions, and Gaussian fundamental modes, thereby facilitating multi-dimensional (de)multiplexing involving CVB modes and wavelengths. As a proof of concept, we theoretically demonstrate a 9-channel multi-dimensional multiplexing system, successfully achieving joint (de)multiplexing of 3 CVB modes (1, 2, and 3) and 3 wavelengths (1550 nm, 1560 nm, and 1570 nm) with a diffraction efficiency exceeding 80%. Additionally, we show the transmission of 16-QAM signals across 9 channels with the bit-error-rates below 10-5. By combining the integrability of metasurfaces with the high-dimensional wavefront manipulation capabilities of multilevel modulation, our strategy can effectively address the diverse demands of different wavelengths and CVB modes in optical communication.

High-order orbital angular momentum mode-based phase shift-keying communication using phase difference modulation.

Orbital angular momentum (OAM) mode offers a promising modulation dimension for high-order shift-keying (SK) communication due to its mode orthogonality. However, the expansion of modulation order through superposing OAM modes is constrained by the mode-field mismatch resulting from the rapidly increased divergence with mode orders. Herein, we address this problem by propose a phase-difference modulation strategy that breaks the limitation of modulation orders via introducing a phase-difference degree of freedom (DoF) beyond OAM modes. Phase-difference modulation exploits the sensitivity of mode interference to phase differences, thereby providing distinct tunable parameters. This enables the generation of a series of codable spatial modes with continuous variation within the same superposed OAM modes by manipulating the interference state. Due to the inherent independence between OAM mode and phase-difference DoF, the number of codable modes increases exponentially, which facilitates establishing ultra-high-order phase shift-keying by discretizing the continuous phase difference and establishing a one-to-one mapping between coding symbols and constructed modes. We show that a phase shift-keying communication link with a modulation order of up to 4 × 104 is achieved by employing only 3 OAM modes (+1, + 2 and +3), and the decode accuracy reaches 99.9%. Since the modulation order is exponentially correlated with the OAM modes and phase differences, the order can be greatly improved by further increasing the superimposed OAM modes, which may provide new insight for high-order OAM-based SK communication.

Adaptation and Phenotypic Diversification in Arabidopsis through Loss-of-Function Mutations in Protein-Coding Genes.

According to the less-is-more hypothesis, gene loss is an engine for evolutionary change. Loss-of-function (LoF) mutations resulting in the natural knockout of protein-coding genes not only provide information about gene function but also play important roles in adaptation and phenotypic diversification. Although the less-is-more hypothesis was proposed two decades ago, it remains to be explored on a large scale. In this study, we identified 60,819 LoF variants in 1071 Arabidopsis (Arabidopsis thaliana) genomes and found that 34% of Arabidopsis protein-coding genes annotated in the Columbia-0 genome do not have any LoF variants. We found that nucleotide diversity, transposable element density, and gene family size are strongly correlated with the presence of LoF variants. Intriguingly, 0.9% of LoF variants with minor allele frequency larger than 0.5% are associated with climate change. In addition, in the Yangtze River basin population, 1% of genes with LoF mutations were under positive selection, providing important insights into the contribution of LoF mutations to adaptation. In particular, our results demonstrate that LoF mutations shape diverse phenotypic traits. Overall, our results highlight the importance of the LoF variants for the adaptation and phenotypic diversification of plants.

Transposable elements drive rapid phenotypic variation in Capsella rubella.

Rapid phenotypic changes in traits of adaptive significance are crucial for organisms to thrive in changing environments. How such phenotypic variation is achieved rapidly, despite limited genetic variation in species that experience a genetic bottleneck is unknown. Capsella rubella, an annual and inbreeding forb (Brassicaceae), is a great system for studying this basic question. Its distribution is wider than those of its congeneric species, despite an extreme genetic bottleneck event that severely diminished its genetic variation. Here, we demonstrate that transposable elements (TEs) are an important source of genetic variation that could account for its high phenotypic diversity. TEs are (i) highly enriched in C. rubella compared with its outcrossing sister species Capsella grandiflora, and (ii) 4.2% of polymorphic TEs in C. rubella are associated with variation in the expression levels of their adjacent genes. Furthermore, we show that frequent TE insertions at FLOWERING LOCUS C (FLC) in natural populations of C. rubella could explain 12.5% of the natural variation in flowering time, a key life history trait correlated with fitness and adaptation. In particular, we show that a recent TE insertion at the 3' UTR of FLC affects mRNA stability, which results in reducing its steady-state expression levels, to promote the onset of flowering. Our results highlight that TE insertions can drive rapid phenotypic variation, which could potentially help with adaptation to changing environments in a species with limited standing genetic variation.

Three-Phase Partitioning for the Extraction and Purification of Polysaccharides from the Immunomodulatory Medicinal Mushroom Inonotus obliquus.

Polysaccharides from the immunomodulatory medicinal mushroom Inonotus obliquus (IOPS) were extracted and purified using three-phase partitioning (TPP), which is an efficient, fast, safe, and green purification technique. An optimal extraction procedure that gave a good 2.2% isolated yield was identified, using the following protocol: a solid-liquid ratio of 1 g to 12 mL; mass fraction of (NH4)2SO4 20% (w/v); 11 mL t-butanol; pH 8.0; temperature 30 °C; and extraction time 30 min. The purified IOPS was shown to be a proteoglycan of 40 kDa molecular weight comprising of d-galactose, d-glucose, d-xylose, and d-mannose in a molar ratio of 2.0:3.5:1.0:1.5. The purified IOPS displayed strong free-radical scavenging abilities, antioxidant activities, and immunological activity in vitro. IOPS' Trolox antioxidant equivalent capacity and ferric-reducing ability of plasma were 251.2 µmol Trolox/g sample and 1040.5 µmol Fe2+/g sample, respectively, with the activity of its immunomodulatory behavior shown to be gradient dependent.

Electron Transfer and Geometric Conversion of Co-NO Moiety in Saddled Porphyrins: Implications for Trigger Role of Tetrapyrrole Distortion.

The electrons of NO and Co are strongly delocalized in normal {Co-NO}8 species. In this work, {Co-NO}8 complexes are induced to convert from (CoII)+•-NO• to CoIII-NO- by a core contraction of 0.06 Šin saddled cobalt(II) porphyrins. This intramolecular electron transfer mechanism indicates that nonplanarity of porphyrin is involved in driving conversion of the NO units from electrophilic NO• as a bent geometry to nucleophilic NO- as a linear geometry. This implies that distortion acts as a trigger in enzymes containing tetrapyrrole. The electronic behaviors of the CoII ions and Co-NO moieties were confirmed by X-ray crystallography, EPR spectroscopy, theoretical calculation, UV-vis and IR spectroscopy, and electrochemistry.

Ultralight Multifunctional Carbon-Based Aerogels by Combining Graphene Oxide and Bacterial Cellulose.

Nanostructured carbon aerogels with outstanding physicochemical properties have exhibited great application potentials in widespread fields and therefore attracted extensive attentions recently. It is still a challenge so far to develop flexible and economical routes to fabricate high-performance nanocarbon aerogels, preferably based on renewable resources. Here, ultralight and multifunctional reduced graphene oxide/carbon nanofiber (RGO/CNF) aerogels are fabricated from graphene oxide and low-cost, industrially produced bacterial cellulose by a three-step process of freeze-casting, freeze-drying, and pyrolysis. The prepared RGO/CNF aerogel possesses a very low apparent density in the range of 0.7-10.2 mg cm-3 and a high porosity up to 99%, as well as a mechanically robust and electrically conductive 3D network structure, which makes it to be an excellent candidate as absorber for oil clean-up and an ideal platform for constructing flexible and stretchable conductors.

A new synthetic method for non-symmetric pillar[5]arenes with simple isolation and improved yield.

The conventional method to synthesize non-symmetric pillar[n]arenes (PA[n]s) generally results in a low yield and requires laborious isolation. We developed a new synthetic method to prepare non-symmetric PA[5]s with various substitutions. Monomers were synthesized starting from commercially available chemicals. The desired products could be easily isolated with an improved yield.

Ultrathin Tungsten Oxide Nanowires/Reduced Graphene Oxide Composites for Toluene Sensing.

Graphene-based composites have gained great attention in the field of gas sensor fabrication due to their higher surface area with additional functional groups. Decorating one-dimensional (1D) semiconductor nanomaterials on graphene also show potential benefits in gas sensing applications. Here we demonstrate the one-pot and low cost synthesis of W18O49 NWs/rGO composites with different amount of reduced graphene oxide (rGO) which show excellent gas-sensing properties towards toluene and strong dependence on their chemical composition. As compared to pure W18O49 NWs, an improved gas sensing response (2.8 times higher) was achieved in case of W18O49 NWs composite with 0.5 wt. % rGO. Promisingly, this strategy can be extended to prepare other nanowire based composites with excellent gas-sensing performance.

Graphene-based macroscopic assemblies and architectures: an emerging material system.

Due to the outstanding physicochemical properties arising from its truly two-dimensional (2D) planar structure with a single-atom thickness, graphene exhibits great potential for use in sensors, catalysts, electrodes, and in biological applications, etc. With further developments in the theoretical understanding and assembly techniques, graphene should enable great changes both in scientific research and practical industrial applications. By the look of development, it is of fundamental and practical significance to translate the novel physical and chemical properties of individual graphene nanosheets into the macroscale by the assembly of graphene building blocks into macroscopic architectures with structural specialities and functional novelties. The combined features of a 2D planar structure and abundant functional groups of graphene oxide (GO) should provide great possibilities for the assembly of GO nanosheets into macroscopic architectures with different macroscaled shapes through various assembly techniques under different bonding interactions. Moreover, macroscopic graphene frameworks can be used as ideal scaffolds for the incorporation of functional materials to offset the shortage of pure graphene in the specific desired functionality. The advantages of light weight, supra-flexibility, large surface area, tough mechanical strength, and high electrical conductivity guarantee graphene-based architectures wide application fields. This critical review mainly addresses recent advances in the design and fabrication of graphene-based macroscopic assemblies and architectures and their potential applications. Herein, we first provide overviews of the functional macroscopic graphene materials from three aspects, i.e., 1D graphene fibers/ribbons, 2D graphene films/papers, 3D network-structured graphene monoliths, and their composite counterparts with either polymers or nano-objects. Then, we present the promising potential applications of graphene-based macroscopic assemblies in the fields of electronic and optoelectronic devices, sensors, electrochemical energy devices, and in water treatment. Last, the personal conclusions and perspectives for this intriguing field are given.

Fabrication of Two-Dimensional Lateral Heterostructures of WS2 /WO3 ⋠H2 O Through Selective Oxidation of Monolayer WS2.

Two-dimensional (2D) lateral heterostructures have emerged as a hot topic in the fast evolving field of advanced functional materials , but their fabrication is challenging. The layer-structured WS2 was theoretically demonstrated to be inert to oxidation except for the monolayer, which can be selectively oxidized owing to the simultaneous interaction of oxygen with both sides. Combined with the theoretical calculations, a new method was developed for the successful construction of 2D lateral heterostructures of WS2 /WO3 ⋅H2 O in an ambient environment, based on a simple liquid-phase solution exfoliation. These lateral heterostructures of WS2 /WO3 ⋅H2 O have interesting properties, as indicated by enhanced photocatalytic activity toward the degradation of methyl orange (MO).

Photothermal poly(N-isopropylacrylamide)/Fe3O4 nanocomposite hydrogel as a movable position heating source under remote control.

Multifunctional nanocomposite hydrogel: swelling-shrink transition of the magnetic sensitive poly(N-isopropylacrylamide)/Fe3O4 (PNIPAM/Fe3O4) nanocomposite hydrogel can be controlled via near-infrared (NIR) laser exposure or non-exposure, which shows potential as a movable position heating source manipulated by combination of an external magnet and near-infrared laser irradiation.

Low-temperature reactivity of Zn+ ions confined in ZSM-5 zeolite toward carbon monoxide oxidation: insight from in situ DRIFT and ESR spectroscopy.

We report the low-temperature catalytic reactivity of Zn(+) ions confined in ZSM-5 zeolite toward CO oxidation. In situ DRIFT and ESR spectroscopy demonstrated that molecular O2 is readily activated by Zn(+) ion to produce O2(-) species at room temperature (298 K) via facile electron transfer between Zn(+) ion and O2 and that the formation of the active O2(-) species is responsible for the high activity of the ZnZSM-5 catalyst toward CO oxidation.

A novel method to fabricate discrete porous carbon hemispheres and their electrochemical properties as supercapacitors.

A simple and efficient method to produce discrete, hierarchical porous carbon hemispheres (CHs) with high uniformity has been successfully developed by constructing nanoreactors and using low crosslinked poly(styrene-co-divinylbenzene) (P(St-co-DVB)) capsules as precursors. The samples are characterized by scanning and transmission electron microscopy, Fourier transform infrared and Raman spectroscopy, X-ray diffraction, and N2 adsorption and desorption. Considering their application, the cyclic voltammetry and electrochemical impedance spectroscopy characterization are tested. The experimental results show that the achievement of discrete and perfect carbon hemispheres is dependent on the proper amount of DVB in the P(St-co-DVB) capsules, which can contribute to the ideal thickness or mechanical strength of the shells. When the amount of DVB is 35 wt% in the precursors, a high Brunauer-Emmett-Teller surface area of 676 m(2) g(-1) can be obtained for the carbon hemispheres, and the extremely large pore volume of 2.63 cm(3) g(-1) can also be achieved at the same time. The electrochemical test shows the carbon hemispheres have a higher specific capacitance of ca. 83 F g(-1) at 10 mV s(-1), compared to other carbon materials. So this method supplies a platform to extend the fabrication field of carbon materials and supplies more chances for the application of carbon materials including carbon hemispheres that are important components and substrates for supercapacitors.

In situ controlled synthesis of thermosensitive poly(N-isopropylacrylamide)/Au nanocomposite hydrogels by gamma radiation for catalytic application.

Thermosensitive poly(N-isopropylacrylamide) (PNIPAM)/Au nanoparticle (NP) nanocomposite hydrogels are synthesized by in situ γ-radiation-assisted polymerization of N-isopropylacrylamide monomer aqueous solution in the presence of HAuCl4·4H2O. In this reaction, the PNIPAM hydrogels and the Au NPs are formed simultaneously, thus demonstrating an easy and straightforward synthetic strategy for the preparation of a uniform nanocomposite. The results suggest that increasing the monomer content during the preparation of nanocomposite materials can increase the sizes of Au NPs. The effects of irradiation dose and concentration of HAuCl4·4H2O on the optical and thermal properties of the hydrogel are also investigated. The PNIPAM/Au nanocomposite hydrogels act as an excellent catalyst for the conversion of o-nitroaniline to 1,2-benzenediamine, and the catalytic activity of the composite hydrogel can be tuned by the volume transition of PNIPAM. The in situ polymerization of monomer and reduction of metal ions initiated by a "clean" and "green" γ-radiation technique can be extended to the efficient synthesis of other nanocomposite materials.

Identification of Serum Oxylipins Associated with the Development of Coronary Artery Disease: A Nested Case-Control Study.

Coronary artery disease (CAD) is among the leading causes of death globally. The American Heart Association recommends that people should consume more PUFA-rich plant foods to replace SFA-rich ones to lower serum cholesterol and prevent CAD. However, PUFA may be susceptible to oxidation and generate oxidized products such as oxylipins. In this study, we investigated whether the blood oxylipin profile is associated with the risk of developing CAD and whether including identified oxylipins may improve the predictability of CAD risk. We designed a nested case-control study with 77 cases and 148 matched controls from a 10-year follow-up of the Nutrition and Health Survey in a Taiwanese cohort of 720 people aged 50 to 70. A panel of 46 oxylipins was measured for baseline serum samples. We discovered four oxylipins associated with CAD risk. 13-oxo-ODE, which has been previously found in formed plagues, was positively associated with CAD (OR = 5.02, 95%CI = 0.85 to 15.6). PGE2/PGD2, previously shown to increase cardiac output, was inversely associated (OR = 0.16, 95%CI = 0.06 to 0.42). 15-deoxy-PGJ2, with anti-inflammatory and anti-apoptosis effects on cardiomyocytes (OR = 0.26, 95%CI = 0.09 to 0.76), and 5-HETE, which was associated with inflammation (OR = 0.28, 95%CI = 0.10 to 0.78), were also negatively associated as protective factors. Adding these four oxylipins to the traditional risk prediction model significantly improved CAD prediction.

Atomic-layered Pt clusters on S-vacancy rich MoS2-x with high electrocatalytic hydrogen evolution.

Developing suitable supports to maximize the atomic utilization efficiency of platinum group metals is of great significance to hydrogen evolution from water splitting. Herein, we report a fully exposed Pt cluster supported on an S-vacancy rich MoS2-x support (Pt/Sv-MoS2-x) by a facile impregnation method. Pt/Sv-MoS2-x exhibits an outstanding electrochemical HER performance with a low overpotential of 26.6 mV at a current density of 10 mA cm-2, a small Tafel slope of 34.8 mV dec-1 and good durability. Most importantly, the mass activity of Pt is an order of magnitude more active than that of commercial Pt/C at an overpotential of 0.08 V. We attribute this exceptional HER catalytic performance to the fact that platinum and Sv-MoS2-x act in synergy to accelerate the reaction kinetics.