Genes specifying long non-coding RNAs (lncRNAs) occupy a large fraction of the genomes of complex organisms. The term 'lncRNAs' encompasses RNA polymerase I (Pol I), Pol II and Pol III transcribed ...RNAs, and RNAs from processed introns. The various functions of lncRNAs and their many isoforms and interleaved relationships with other genes make lncRNA classification and annotation difficult. Most lncRNAs evolve more rapidly than protein-coding sequences, are cell type specific and regulate many aspects of cell differentiation and development and other physiological processes. Many lncRNAs associate with chromatin-modifying complexes, are transcribed from enhancers and nucleate phase separation of nuclear condensates and domains, indicating an intimate link between lncRNA expression and the spatial control of gene expression during development. lncRNAs also have important roles in the cytoplasm and beyond, including in the regulation of translation, metabolism and signalling. lncRNAs often have a modular structure and are rich in repeats, which are increasingly being shown to be relevant to their function. In this Consensus Statement, we address the definition and nomenclature of lncRNAs and their conservation, expression, phenotypic visibility, structure and functions. We also discuss research challenges and provide recommendations to advance the understanding of the roles of lncRNAs in development, cell biology and disease.
2D materials are of particular interest in light‐to‐heat conversion, yet challenges remain in developing a facile method to suppress their light reflection. Herein, inspired by the black scales of ...Bitis rhinoceros, a generalized approach via sequential thermal actuations to construct biomimetic 2D‐material nanocoatings, including Ti3C2Tx MXene, reduced graphene oxide (rGO), and molybdenum disulfide (MoS2) is designed. The hierarchical MXene nanocoatings result in broadband light absorption (up to 93.2%), theoretically validated by optical modeling and simulations, and realize improved light‐to‐heat performance (equilibrium temperature of 65.4 °C under one‐sun illumination). With efficient light‐to‐heat conversion, the bioinspired MXene nanocoatings are next incorporated into solar steam‐generation devices and stretchable solar/electric dual‐heaters. The MXene steam‐generation devices require much lower solar‐thermal material loading (0.32 mg cm−2) and still guarantee high steam‐generation performance (1.33 kg m−2 h−1) compared with other state‐of‐the‐art devices. Additionally, the mechanically deformed MXene structures enable the fabrication of stretchable and wearable heaters dual‐powered by sunlight and electricity, which are reversibly stretched and heated above 100 °C. This simple fabrication process with effective utilization of active materials promises its practical application value for multiple solar–thermal technologies.
Inspired by the black scales of Bitis rhinoceros, a generalized approach is developed via sequential thermal actuations to construct biomimetic 2D‐material nanocoatings, including Ti3C2Tx MXene, reduced graphene oxide, and MoS2. The hierarchical MXene nanocoatings result in broadband light absorption, and realize improved light‐to‐heat performance, demonstrating extremely practical application value in solar steam generation and wearable thermal management.
Research Summary: While research has focused primarily on stars as individual contributors, we examine organizational situations where stars must work closely with non-stars. We argue that, in such ...situations, building teamwork around a star is an exercise in learning under complexity. In response, organizations prioritize interactions involving the star to simplify learning. This simplification, however, creates organizational myopia. We claim that a star's temporary absence helps the organization overcome myopia by triggering a search for new routines. When he returns, the organization may combine these new routines with pre-absence routines to improve teamwork and performance. We exploit injuries to star players in the National Basketball Association as an exogenous shock and find that on average, teams perform better after a star's return than before his absence. Managerial Summary: This study examines the effect of the temporary absence of a star evidence that a star employee's temporary absence helps the organization overcome an over-reliance on the star and improve teamwork. Improved teamwork, in turn, enables the organization to perform better upon the star's return than it did prior to his absence. This result suggests that organizations might want to revisit the tendency to view stars as too valuable to lose, even for a short time. In particular, organizations may want to pull stars from ongoing projects and encourage them to attend professional development programs. A star's temporary absence and return from such a program improves not only the star's skills but also the organization's teamwork.
Highly active, stable, and cheap Pt‐free catalysts for the hydrogen evolution reaction (HER) are facing increasing demand as a result of their potential use in future energy‐conversion systems. ...However, the development of HER electrocatalysts with Pt‐like or even superior activity, in particular ones that can function under alkaline conditions, remains a significant challenge. Here, the synthesis of a novel carbon‐loaded ruthenium nanoparticle electrocatalyst (Ru@CQDs) for the HER, using carbon quantum dots (CQDs), is reported. Electrochemical tests reveal that, even under extremely alkaline conditions (1 m KOH), the as‐formed Ru@CQDs exhibits excellent catalytic behavior with an onset overpotential of 0 mV, a Tafel slope of 47 mV decade−1, and good durability. Most importantly, it only requires an overpotential of 10 mV to achieve the current density of 10 mA cm−2. Such catalytic characteristics are superior to the current commercial Pt/C and most noble metals, non‐noble metals, and nonmetallic catalysts under basic conditions. These findings open a new field for the application of CQDs and add to the growing family of metal@CQDs with high HER performance.
The ruthenium@carbon quantum dots (Ru@CQDs) electrocatalyst is very robust for the hydrogen evolution reaction in alkaline media, with an onset overpotential of 0 mV and low overpotentials at 10 mA cm−2 (10 mV). More importantly, after 10 000 cycles, the current density at 10 mA cm−2 of the Ru@CQDs catalyst increases merely 4 mV at 10 mA cm−2.
In the emerging Internet of Things, stretchable antennas can facilitate wireless communication between wearable and mobile electronic devices around the body. The proliferation of wireless devices ...transmitting near the human body also raises interference and safety concerns that demand stretchable materials capable of shielding electromagnetic interference (EMI). Here, an ultrastretchable conductor is fabricated by depositing a crumple‐textured coating composed of 2D Ti3C2Tx nanosheets (MXene) and single‐walled carbon nanotubes (SWNTs) onto latex, which can be fashioned into high‐performance wearable antennas and EMI shields. The resulting MXene‐SWNT (S‐MXene)/latex devices are able to sustain up to an 800% areal strain and exhibit strain‐insensitive resistance profiles during a 500‐cycle fatigue test. A single layer of stretchable S‐MXene conductors demonstrate a strain‐invariant EMI shielding performance of ≈30 dB up to 800% areal strain, and the shielding performance is further improved to ≈47 and ≈52 dB by stacking 5 and 10 layers of S‐MXene conductors, respectively. Additionally, a stretchable S‐MXene dipole antenna is fabricated, which can be uniaxially stretched to 150% with unaffected reflected power <0.1%. By integrating S‐MXene EMI shields with stretchable S‐MXene antennas, a wearable wireless system is finally demonstrated that provides mechanically stable wireless transmission while attenuating EM absorption by the human body.
2D titanium carbide–based ultrastretchable conductors are fabricated by harnessing the surface instability of pre‐stretched latex, showing strain‐invariant performance in stretchable electromagnetic interference (EMI) shields and wearable wireless communicators, respectively. Finally, a wearable antenna with on‐site EM protection for the human body is demonstrated, which exhibits mechanically stable and efficient wireless communication and shielding performance.
We present a study of extended galaxy halo gas through H i and O vi absorption over two decades in projected distance at z ... 0.2. The study is based on a sample of 95 galaxies from a highly ...complete (>80 per cent) survey of faint galaxies (L > 0.1L...) with archival quasar absorption spectra and 53 galaxies from the literature. A clear anticorrelation is found between H i (O vi) column density and virial radius normalized projected distance, d/R... Strong H i (O vi) absorption systems with column densities greater than 10... (10...) cm... are found for 48 of 54 (36 of 42) galaxies at d < R... indicating a mean covering fraction of ...Hi...=0.89 (...Ovi...=0.86). O vi absorbers are found at d ... R..., beyond the extent observed for lower ionization species. At d/R... = 1-3 strong H i (O vi) absorption systems are found for only 7 of 43 (5 of 34) galaxies (...Hi...=0.16 and ...Ovi...=0.15). Beyond d = 3 R..., the H i and O vi covering fractions decrease to levels consistent with coincidental systems. The high completeness of the galaxy survey enables an investigation of environmental dependence of extended gas properties. Galaxies with nearby neighbours exhibit a modest increase in O vi covering fraction at d > R... compared to isolated galaxies (...Ovi...0.13 versus 0.04) but no excess H i absorption. These findings suggest that environmental effects play a role in distributing heavy elements beyond the enriched gaseous haloes of individual galaxies. Finally, we find that differential H i and O vi absorption between early- and late-type galaxies continues from d < R... to d ... 3 R... (ProQuest: ... denotes formulae/symbols omitted.)
Noncoding mutations in cancer genomes are frequent but challenging to interpret. PVT1 encodes an oncogenic lncRNA, but recurrent translocations and deletions in human cancers suggest alternative ...mechanisms. Here, we show that the PVT1 promoter has a tumor-suppressor function that is independent of PVT1 lncRNA. CRISPR interference of PVT1 promoter enhances breast cancer cell competition and growth in vivo. The promoters of the PVT1 and the MYC oncogenes, located 55 kb apart on chromosome 8q24, compete for engagement with four intragenic enhancers in the PVT1 locus, thereby allowing the PVT1 promoter to regulate pause release of MYC transcription. PVT1 undergoes developmentally regulated monoallelic expression, and the PVT1 promoter inhibits MYC expression only from the same chromosome via promoter competition. Cancer genome sequencing identifies recurrent mutations encompassing the human PVT1 promoter, and genome editing verified that PVT1 promoter mutation promotes cancer cell growth. These results highlight regulatory sequences of lncRNA genes as potential disease-associated DNA elements.
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•Silencing PVT1 promoter enhances breast cancer cell competition•PVT1 promoter inhibits MYC transcription independent of PVT1 lncRNA•PVT1 and MYC promoters compete for enhancer contact in cis•Mutations encompassing PVT1 promoter are recurrent in human cancers
Recurrent mutations in human cancer are found encompassing the promotor for the lncRNA gene PVT1, which regulates MYC transcription via promoter competition for a shared set of enhancers.
Circadian rhythms are a pervasive property of mammalian cells, tissues and behaviour, ensuring physiological adaptation to solar time. Models of cellular timekeeping revolve around transcriptional ...feedback repression, whereby CLOCK and BMAL1 activate the expression of PERIOD (PER) and CRYPTOCHROME (CRY), which in turn repress CLOCK/BMAL1 activity. CRY proteins are therefore considered essential components of the cellular clock mechanism, supported by behavioural arrhythmicity of CRY‐deficient (CKO) mice under constant conditions. Challenging this interpretation, we find locomotor rhythms in adult CKO mice under specific environmental conditions and circadian rhythms in cellular PER2 levels when CRY is absent. CRY‐less oscillations are variable in their expression and have shorter periods than wild‐type controls. Importantly, we find classic circadian hallmarks such as temperature compensation and period determination by CK1δ/ε activity to be maintained. In the absence of CRY‐mediated feedback repression and rhythmic Per2 transcription, PER2 protein rhythms are sustained for several cycles, accompanied by circadian variation in protein stability. We suggest that, whereas circadian transcriptional feedback imparts robustness and functionality onto biological clocks, the core timekeeping mechanism is post‐translational.
SYNOPSIS
CRYPTOCHROME (CRY) proteins are central regulators of the circadian clock transcription/translation feedback loop. The finding that circadian timekeeping persists, albeit with reduced robustness, in CRY‐deficient cells and mice suggests that clock gene activity is determined by evolutionarily‐conserved post‐translational timing mechanisms.
CRY‐mediated transcriptional feedback is dispensable for circadian timekeeping in mammalian cells, but functions to make rhythms more robust.
CRY knockout mice exhibit behavioural rhythmicity under specific environmental conditions.
Circadian variation in the abundance of core clock component PER2 is amplified by, but does not require, rhythmic Per2 transcription.
CK1 and GSK3 kinases regulate PER2 stability in the absence of CRY.
Circadian timekeeping in the absence of CRYPTOCHROME provides further support to the central role of post‐translational regulation in the mammalian circadian clock mechanism.
Focused ultrasound (FUS) in the presence of microbubbles can transiently open the blood-brain barrier (BBB) to increase therapeutic agent penetration at the targeted brain site to benefit recurrent ...glioblastoma (rGBM) treatment. This study is a dose-escalating pilot trial using a device combining neuronavigation and a manually operated frameless FUS system to treat rGBM patients. The safety and feasibility were established, while a dose-dependent BBB-opening effect was observed, which reverted to baseline within 24 hours after treatment. No immunological response was observed clinically under the applied FUS level in humans; however, selecting a higher level in animals resulted in prolonged immunostimulation, as confirmed preclinically by the recruitment of lymphocytes into the tumor microenvironment (TME) in a rat glioma model. Our findings provide preliminary evidence of FUS-induced immune modulation as an additional therapeutic benefit by converting the immunosuppressive TME into an immunostimulatory TME via a higher but safe FUS dosage.
Large bandgap of pressurized trilayer graphene Ke, Feng; Chen, Yabin; Yin, Ketao ...
Proceedings of the National Academy of Sciences,
05/2019, Letnik:
116, Številka:
19
Journal Article
Recenzirano
Odprti dostop
Graphene-based nanodevices have been developed rapidly and are now considered a strong contender for postsilicon electronics. However, one challenge facing graphene-based transistors is opening a ...sizable bandgap in graphene. The largest bandgap achieved so far is several hundred meV in bilayer graphene, but this value is still far below the threshold for practical applications. Through in situ electrical measurements, we observed a semi-conducting character in compressed trilayer graphene by tuning the interlayer interaction with pressure. The optical absorption measurements demonstrate that an intrinsic bandgap of 2.5 ± 0.3 eV could be achieved in such a semiconducting state, and once opened could be preserved to a few GPa. The realization of wide bandgap in compressed trilayer graphene offers opportunities in carbon-based electronic devices.
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