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.
Perovskites in catalysis and electrocatalysis Hwang, Jonathan; Rao, Reshma R.; Giordano, Livia ...
Science (American Association for the Advancement of Science),
11/2017, Letnik:
358, Številka:
6364
Journal Article
Recenzirano
Odprti dostop
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.
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.
Early invasive growth along specific anatomical structures, especially the white matter tract, is regarded as one of the main causes of poor therapeutic outcome of people with gliomas. We show that ...some glioma stem cells (GSCs) are preferentially located along white matter tracts, which exhibit a demyelinated phenotype, at the invasive frontier of glioma tissues. These GSCs are CD133
Notch1
, whereas the nerve fibers express the Notch ligand Jagged1. The Notch-induced transcription factor Sox9 promotes the transcription of SOX2 and the methylation level of the NOTCH1 promoter is attenuated by the upregulation of SOX2 to reinforce NOTCH1 expression in GSCs. This positive-feedback loop in a cohort of glioma subjects is correlated with a poor prognosis. Inhibition of Notch signaling attenuates the white-matter-tract tropism of GSCs. These findings provide evidence indicating that the NOTCH1-SOX2 positive-feedback loop controls GSC invasion along white matter tracts.
Deep‐penetration fluorescence imaging in the second near‐infrared (NIR‐II) window heralds a new era of clinical surgery, in which high‐resolution vascular/lymphatic anatomy and detailed cancerous ...tissues can be visualized in real time. Described here is a series of polymethine‐based semiconducting polymers with intrinsic emission maxima in the NIR‐IIa (1300–1400 nm) window and absorption maxima ranging from 1082 to 1290 nm. These polymers were prepared as semiconducting polymer dots (Pdots) in aqueous solutions with fluorescence quantum yields of 0.05–0.18 %, and they demonstrate promising applications in noninvasive through‐skull brain imaging in live mice with remarkable spatial resolution as well as signal‐to‐background contrast. This study offers a platform for future design of NIR‐IIa or even NIR‐IIb emitting Pdots.
A novel series of polymethine‐based semiconducting polymers were synthesized for the first time and prepared as Pdots in water with both absorption and emission in the NIR‐II window. These Pdots can be further applied for deep‐tissue non‐invasive fluorescence imaging.
The development of stable and efficient hydrogen evolution reaction (HER) catalysts is essential for the production of hydrogen as a clean energy resource. A combination of experiment and theory ...demonstrates that the normally inert basal planes of 2D layers of MoS2 can be made highly catalytically active for the HER when alloyed with rhenium (Re). The presence of Re at the ≈50% level converts the material to a stable distorted tetragonal (DT) structure that shows enhanced HER activity as compared to most of the MoS2‐based catalysts reported in the literature. More importantly, this new alloy catalyst shows much better stability over time and cycling than lithiated 1T‐MoS2. Density functional theory calculations find that the role of Re is only to stabilize the DT structure, while catalysis occurs primarily in local Mo‐rich DT configurations, where the HER catalytic activity is very close to that in Pt. The study provides a new strategy to improve the overall HER performance of MoS2‐based materials via chemical doping.
Re‐doped MoS2 atomic layers in the distorted tetragonal structure show excellent activity and stability for electrocatalytic hydrogen production. Atomic‐level scanning transmission electron microscopy combined with density functional theory calculations reveal active local Mo‐rich structures and explain the best performance in Re0.55Mo0.45S2. The study provides a new catalyst design strategy through chemical doping.
The aim of this study was to summarize and discuss the similarities and differences in inflammatory biomarkers in postoperative delirium (POD) and cognitive dysfunction (POCD).
A systematic retrieval ...of literature up to June 2017 in PubMed, Embase, the Cochrane Library, the China National Knowledge Infrastructure database, and the Wanfang database was conducted. Extracted data were analyzed with STATA (version 14). The standardized mean difference (SMD) and the 95% confidence interval (95% CI) of each indicator were calculated using a random effect model. We also performed tests of heterogeneity, sensitivity analysis, assessments of bias, and meta-regression in this meta-analysis.
A total of 54 observational studies were included. By meta-analysis we found significantly increased C-reactive protein (CRP) (9 studies, SMD 0.883, 95% CI 0.130 to 1.637, P = 0.022 in POD; 10 studies, SMD -0.133, 95% CI -0.512 to 0.246, P = 0.429 in POCD) and interleukin (IL)-6 (7 studies, SMD 0.386, 95% CI 0.054 to 0.717, P = 0.022 in POD; 16 studies, SMD 0.089, 95% CI -0.133 to 0.311, P = 0.433 in POCD) concentrations in both POD and POCD patients. We also found that the SMDs of CRP and IL-6 from POCD patients were positively correlated with surgery type in the meta-regression (CRP: Coefficient = 1.555365, P = 0.001, 10 studies; IL-6: Coefficient = -0.6455521, P = 0.086, 16 studies).
Available evidence from medium-to-high quality observational studies suggests that POD and POCD are indeed correlated with the concentration of peripheral inflammatory markers. Some of these markers, such as CRP and IL-6, play roles in both POD and POCD, while others are specific to either one of them.
PDF
