Abstract
By electronically wiring-up living cells with abiotic conductive surfaces, bioelectrochemical systems (BES) harvest energy and synthesize electric-/solar-chemicals with unmatched ...thermodynamic efficiency. However, the establishment of an efficient electronic interface between living cells and abiotic surfaces is hindered due to the requirement of extremely close contact and high interfacial area, which is quite challenging for cell and material engineering. Herein, we propose a new concept of a single cell electron collector, which is
in-situ
built with an interconnected intact conductive layer on and cross the individual cell membrane. The single cell electron collector forms intimate contact with the cellular electron transfer machinery and maximizes the interfacial area, achieving record-high interfacial electron transfer efficiency and BES performance. Thus, this single cell electron collector provides a superior tool to wire living cells with abiotic surfaces at the single-cell level and adds new dimensions for abiotic/biotic interface engineering.
The cereal endosperm is a major factor determining seed size and shape. However, the molecular mechanisms of endosperm development are not fully understood. Long noncoding RNAs (lncRNAs) function in ...various biological processes. Here we show a lncRNA, MISSEN, that plays an essential role in early endosperm development in rice (Oryza sativa). MISSEN is a parent-of-origin lncRNA expressed in endosperm, and negatively regulates endosperm development, leading to a prominent dent and bulge in the seed. Mechanistically, MISSEN functions through hijacking a helicase family protein (HeFP) to regulate tubulin function during endosperm nucleus division and endosperm cellularization, resulting in abnormal cytoskeletal polymerization. Finally, we revealed that the expression of MISSEN is inhibited by histone H3 lysine 27 trimethylation (H3K27me3) modification after pollination. Therefore, MISSEN is the first lncRNA identified as a regulator in endosperm development, highlighting the potential applications in rice breeding.
N6-Methyladenosine (m6A) RNA methylation plays important roles during development in different species. However, knowledge of m6A RNA methylation in monocots remains limited. In this study, we ...reported that OsFIP and OsMTA2 are the components of m6A RNA methyltransferase complex in rice and uncovered a previously unknown function of m6A RNA methylation in regulation of plant sporogenesis. Importantly, OsFIP is essential for rice male gametogenesis. Knocking out of OsFIP results in early degeneration of microspores at the vacuolated pollen stage and simultaneously causes abnormal meiosis in prophase I. We further analyzed the profile of rice m6A modification during sporogenesis in both WT and OsFIP loss-of-function plants, and identified a rice panicle specific m6A modification motif "UGWAMH". Interestingly, we found that OsFIP directly mediates the m6A methylation of a set of threonine protease and NTPase mRNAs and is essential for their expression and/or splicing, which in turn regulates the progress of sporogenesis. Our findings revealed for the first time that OsFIP plays an indispensable role in plant early sporogenesis. This study also provides evidence for the different functions of the m6A RNA methyltransferase complex between rice and Arabidopsis.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Sodium storage capacity, mobility, and volume change during sodiation on the surfaces of interlayer-expanded Ti3C2 MXenes are investigated using ab initio density functional theory. The theoretical ...results reveal that the interlayer-expanded bare, F-, O-, and OH-functionalized Ti3C2 MXenes exhibit low barriers for sodium diffusion and small changes of lattice constant during sodiation. In addition, enlarged interlayer distance enables the stable multilayer adsorption on the bare and O-functionalized Ti3C2 MXenes and therefore significantly enhances their theoretical capacities. Both bare and O-functionalized Ti3C2 MXenes are predicted to be prospective anode materials for sodium-ion batteries with high theoretical capacities, fast discharge/charge rates, and good cycling performances. The present results provide a new route to improve the battery performances of anode materials based on MXene intercalation hosts.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
5.
Perovskites in catalysis and electrocatalysis Hwang, Jonathan; Rao, Reshma R.; Giordano, Livia ...
Science (American Association for the Advancement of Science),
11/2017, Volume:
358, Issue:
6364
Journal Article
Peer reviewed
Catalysts for chemical and electrochemical reactions underpin many aspects of modern technology and industry, from energy storage and conversion to toxic emissions abatement to chemical and materials ...synthesis. This role necessitates the design of highly active, stable, yet earth-abundant heterogeneous catalysts. In this Review, we present the perovskite oxide family as a basis for developing such catalysts for (electro)chemical conversions spanning carbon, nitrogen, and oxygen chemistries. A framework for rationalizing activity trends and guiding perovskite oxide catalyst design is described, followed by illustrations of how a robust understanding of perovskite electronic structure provides fundamental insights into activity, stability, and mechanism in oxygen electrocatalysis. We conclude by outlining how these insights open experimental and computational opportunities to expand the compositional and chemical reaction space for next-generation perovskite catalysts.
Full text
Available for:
BFBNIB, NMLJ, NUK, ODKLJ, PNG, SAZU, UL, UM, UPUK
Display omitted
•V2Ch2O monolayers exhibit highly mechanic, dynamic and thermal stabilities.•V2Ch2O monolayers have high storage capacities of potassium.•Lattice parameter changes are within 7.26% ...duaring K-intercalation.•There is no phase transition during K-intercalation, avoiding potential hysteresis.•V2S2O monolayer is a promising electrode material for K-ion batteries.
A new category of two-dimensional electrode materials, i.e., V2Ch2O (Ch = S, Se and Te) monolayers was explored for K-ion batteries (PIBs) based on principle of chemical exfoliation, density functional theory and ab initio molecular dynamics simulations. The V2Ch2O monolayers show low cleavage energies and excellent thermal, dynamical and mechanical stabilities. Adsorption energies of a potassium atom on the V2Ch2O monolayers are exothermic, which are of benefit to prevent forming dendrites. The existence of electrode potentials substantially decreases the diffusion barriers of potassium atoms on the three V2Ch2O monolayers. The V2Ch2O monolayers are able to maintain their metallic characteristics and single surface phase during the whole K-intercalation process, avoiding the decrease in electronic conductivity and the appearance of potential hysteresis. The theoretical specific capacities of the V2S2O, V2Se2O and V2Te2O monolayers are predicted to be 883.6, 583.1 and 431.0 mAh g−1, respectively, and the corresponding average open-circuit voltages are 0.449, 0.390 and 0.293 V, respectively. The maximum percentage changes in lattice parameters are 4.21%, 6.07% and 7.26% for the V2S2O, V2Se2O and V2Te2O monolayers, respectively. All the calculated properties indicate that the V2Ch2O monolayers are promising electrode materials for PIBs with high capacities and long cycle lives.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Silicene has recently shown high electrochemical performance with discharging product Li2O(s) and high stability, avoiding discharging byproducts for nonaqueous lithium–oxygen batteries. At the ...fundamental level, little was known about the effect of defects existing in silicene surface and various solvents on the discharging and charging processes occurring in the batteries. Here, ab initio density functional theory is employed to explore the mechanisms of oxygen reduction to Li2O(s) (ORR) on discharge and the reverse reactions on pristine and defective silicenes including single vacancy (SV), double vacancies (DV), and Stone–Thrower–Wales (STW) defects. The influence of the permittivity of solvents on the adsorption energy of the ORR intermediates as well as the stability of the cathode materials in dimethyl sulfoxide (DMSO) and 1,2-dimethoxyethane (DME) is evaluated. The analysis of the calculated results suggests that the defects show higher overpotentials when compared with pristine silicene due to their stronger attraction with the ORR intermediates, especially for LiO2(s) and lithium atoms. Pristine and three defective silicenes exhibit similar electrochemical performance in different solvents and their stabilities are related to the solvents used. Our investigation identifies the role of defective structures in silicene surfaces and the stability toward DMSO and DME. High performance of silicene cathode materials for lithium–oxygen batteries can be achieved by tuning the interaction between the ORR intermediates and silicene surfaces with attached hydrophobic functional groups.
Full text
Available for:
IJS, KILJ, NUK, PNG, UL, UM
Noncovalent macrocycle‐confined supramolecular purely organic room‐temperature phosphorescence (RTP) is a current research hotspot. Herein, a high‐efficiency noncovalent polymerization‐activated ...near‐infrared (NIR)‐emissive RTP‐harvesting system in aqueous solution based on the stepwise confinement of cucurbit7uril (CB7) and β‐cyclodextrin‐grafted hyaluronic acid (HACD), is reported. Compared with the dodecyl‐chain‐bridged 6‐bromoisoquinoline derivative (G), the dumbbell‐shaped assembly G⊂CB7 presents an appeared complexation‐induced RTP signal at 540 nm via the first confinement of CB7. Subsequently, benefitting from the stepwise confinement encapsulation of the β‐cyclodextrin cavity, the subsequent noncovalent polymerization of the binary G⊂CB7 assembly enabled by HACD can contribute to the further‐enhanced RTP emission intensity approximately eight times in addition to an increased lifetime from 59.0 µs to 0.581 ms. Moreover, upon doping a small amount of two types of organic dyes, Nile blue or tetrakis(4‐sulfophenyl)porphyrin as an acceptor into the supramolecular confinement assembly G⊂CB7 @ HACD, efficient RTP energy transfer occurs accompanied by a long‐lived NIR‐emitting performance (680 and 710 nm) with a high donor/acceptor ratio. Intriguingly, the prepared RTP‐harvesting system is successfully applied for targeted NIR imaging of living tumor cells by utilizing the targeting ability of hyaluronic acid, which provides a new strategy to create advanced water‐soluble NIR phosphorescent materials.
A highly efficient noncovalent polymerization‐activated phosphorescence‐harvesting system is successfully constructed in aqueous solution based on the stepwise confinement of cucurbit7uril and β‐cyclodextrin‐grafted hyaluronic acid, which shows high phosphorescence energy transfer efficiency accompanied by a long‐lived near‐infrared (NIR) emitting performance, and is ultimately applied for NIR targeted imaging of cancer cells.
Full text
Available for:
BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The electronic and adsorption properties of graphene can be changed significantly through substitutional doping with nitrogen and nitrogen decoration of vacancies. Here ab initio density functional ...theory with a dispersion correction was used to investigate the stability, magnetic and adsorption properties of nine defects in graphene, including both nitrogen substitutional doping and nitrogen decoration of vacancies. The results indicate that only pyridinic N2V2 defect in graphene shows a ferromagnetic spin structure with high magnetic moment and magnetic stabilization energy. Not all nitrogen-doped defects can improve the capacity of the lithium-ion batteries. The adsorption energies of a lithium atom on nitrogen-substituted graphenes are more positive, indicating that they are meta-stable and no better than the pristine graphene as anode materials of lithium-ion batteries. Nitrogen-decorated single and double vacancy defects, especially for the pyridinic N2V2 defect in graphene, can greatly improve the reversible capacity of the battery in comparison with the pristine graphene. The theoretical prediction of the reversible capacity of the battery is 1039 mA h g(-1) for the nitrogen-doped graphene material synthesized by Wu et al., which is in good agreement with the experimental data (1043 mA h g(-1)). The theoretical computations suggest that nitrogen-decorated single and double vacancy defects in graphene are the promising candidate for anode materials of lithium-ion batteries. Each nitrogen atom in the decoration can improve the reversible capacity of the battery by 63.3-124.5 mA h g(-1) in a 4 × 4 supercell of graphene. The present work provides crucial information for the development of N-doped graphene-based anode materials of lithium-ion batteries.
PDF
