ABSTRACT
The lack of acid-proof high-potential cathode largely limits the development and competitiveness of proton batteries. Herein, the authors systematically investigated six dihydroxynaphthalenes (DHNs) and found that 2,6-DHN delivered the best cathode performance in proton battery with the highest redox potential (0.84 V, vs SHE) and a specific capacity of 91.6 mAh g-1 at 1 A g-1 . In situ solid-state electropolymerization of DHNs is responsible for the voltage and capacity fading of DHNs, and 2,6-DHN's excellent electrochemical performance is derived from its high polymerization energy barrier. By compounding with rGO, the 2,6-DHN/rGO electrode can maintain a specific capacity of 89 mAh g-1 even after 12â¯000 cycles at 5 A g-1 . When it is paired with the 2,6-dihydroxyanthraquinone (DHAQ) anode, the assembled rocking-chair all-organic proton battery exhibited a high cell voltage of 0.85 V, and excellent energy/power densities (70.8 Wh kg-1 /850 W kg-1 ). This study showcases a new-type high-potential proton-containing organic cathode and paves the way for constructing a high-voltage rocking-chair proton battery. Also, in situ solid-state electropolymerization will inspire the further study of phenol-based small-molecule electrodes.
ABSTRACT
It is still challenging to find a spherical-aberration-free singlet lens with well corrected coma due to an undesired and complicated residual high-order coma. In this paper, we present a spherical-aberration-free singlet lens with reduced coma containing high-order coma contribution. This design algorithm is to deduce the front aspherical surface parameters from the back spherical surface using meridional ray tracing to find the proper values of the back focal length and the back spherical radius to reduce the coma. The exemplary lens demonstrates an excellent well-balanced and diffraction-limited performance at the field angle ranging from 0.0° to 2.5° with a working F# equal to 1.65.
ABSTRACT
Benefiting from the proton's small size and ultrahigh mobility in water, aqueous proton batteries are regarded as an attractive candidate for high-power and ultralow-temperature energy storage devices. Herein, a new-type C4 N polymer with uniform micropores and a large specific surface area is prepared by sulfuric acid-catalyzed ketone amine condensation reaction and employed as the electrode of proton batteries. Multi-walled carbon nanotubes (MWCNT) are introduced to induce the in situ growth of C4 N, and reaped significantly enhanced porosity and conductivity, and thus better both room- and low-temperature performance. When coupled with MnO2 @Carbon fiber (MnO2 @CF) cathode, MnO2 @CF//C4 N-50% MWCNT full battery shows unprecedented cycle stability with a capacity retention of 98% after 11 000 cycles at 10 A g-1 and even 100% after 70 000 cycles at 20 A g-1 . Additionally, a novel anti-freezing electrolyte (5 m H2 SO4 + 0.5 m MnSO4 ) is developed and showed a high ionic conductivity of 123.2 mS cm-1 at -70 °C. The resultant MnO2 @CF//C4 N-50% MWCNT battery delivers a specific capacity of 110.5 mAh g-1 even at -70 °C at 1 A g-1 , the highest in all reported proton batteries under the same conditions. This work is expected to offer a package solution for constructing high-performance ultralow-temperature aqueous proton batteries.
ABSTRACT
Recent evidence suggests that many endogenous circular RNAs (circRNAs) may play roles in biological processes. However, the expression patterns and functions of circRNAs in human diseases are not well understood. Computationally identifying circRNAs from total RNA-seq data is a primary step in studying their expression pattern and biological roles. In this work, we have developed a computational pipeline named UROBORUS to detect circRNAs in total RNA-seq data. By applying UROBORUS to RNA-seq data from 46 gliomas and normal brain samples, we detected thousands of circRNAs supported by at least two read counts, followed by successful experimental validation on 24 circRNAs from the randomly selected 27 circRNAs. UROBORUS is an efficient tool that can detect circRNAs with low expression levels in total RNA-seq without RNase R treatment. The circRNAs expression profiling revealed more than 476 circular RNAs differentially expressed in control brain tissues and gliomas. Together with parental gene expression, we found that circRNA and its parental gene have diversified expression patterns in gliomas and control brain tissues. This study establishes an efficient and sensitive approach for predicting circRNAs using total RNA-seq data. The UROBORUS pipeline can be accessed freely for non-commercial purposes at http://uroborus.openbioinformatics.org/.
Subject(s)
Computational Biology/methods , Glioma/genetics , RNA/genetics , Base Sequence , Brain/cytology , Gene Library , Humans , RNA, Circular , Sequence Analysis, RNAABSTRACT
One of the two branches of the α-linolenic acid metabolism pathway is catalyzed by 12-oxo-phytodienoic acid reductase I, and the other is involved in jasmonic acid (JA) synthesis. The former is known to be active in the response to salinity tolerance in wheat (Triticum aestivum), but the participation of the latter in this response has not been established as yet. Here, the salinity-responsive bread wheat gene TaAOC1, which encodes an allene oxide cyclase involved in the α-linolenic acid metabolism pathway, was constitutively expressed in both bread wheat and Arabidopsis (Arabidopsis thaliana). In both species, transgenic lines exhibited an enhanced level of tolerance to salinity. The transgenic plants accumulated a higher content of JA and developed shorter roots. Both the shortened roots and the salinity tolerance were abolished in a background lacking a functional AtMYC2, a key component of the JA and abscisic acid signaling pathway, but were still expressed in a background deficient with respect to abscisic acid synthesis. We provide the first evidence, to our knowledge, suggesting that JA is also involved in the plant salinity response and that the α-linolenic acid metabolism pathway has a regulatory role over this response.
Subject(s)
Cyclopentanes/metabolism , Intramolecular Oxidoreductases/genetics , Oxylipins/metabolism , Plant Proteins/genetics , Salt Tolerance/genetics , Signal Transduction/genetics , Triticum/enzymology , Triticum/genetics , Adaptation, Physiological/drug effects , Adaptation, Physiological/genetics , Arabidopsis/drug effects , Arabidopsis/genetics , Arabidopsis/physiology , Arabidopsis Proteins/metabolism , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Hydrogen Peroxide/pharmacology , Intramolecular Oxidoreductases/metabolism , Models, Biological , Molecular Sequence Data , Osmosis/drug effects , Phenotype , Phylogeny , Plant Growth Regulators/pharmacology , Plant Leaves/drug effects , Plant Leaves/physiology , Plant Proteins/metabolism , Plants, Genetically Modified , Salt Tolerance/drug effects , Seedlings/drug effects , Seedlings/genetics , Signal Transduction/drug effects , Stress, Physiological/genetics , Triticum/drug effects , Triticum/physiology , Up-Regulation/drug effectsABSTRACT
A compact Ka-band antenna array has been proposed to realize broadband and high gain for millimeter-wave applications. The antenna array is divided into a multilayer composed of a driven slot patch layer and a parasitic patch array layer, which is excited by a mixed CPW-Slot-Couple feeding network layer. According to characteristic mode analysis, a pair of narrow coupling slots are introduced in the driven patch to move the resonant frequency of characteristic mode 3 to the resonant frequency of characteristic mode 2 for enhanced bandwidth. In this article, a 1to4 CPW-Slot-Couple feeding network for a 2 × 2 driven slot patch array is implemented, and then each driven slot patch excites a 2 × 2 parasitic patch array. Finally, a proposed 4 × 4 × 3 (row × column × layer) Ka-band antenna array is fabricated to verify the design concepts. The measured results show that the frequency bandwidth of the antenna array is 25 GHz to 32 GHz, and the relative bandwidth is 24.5%. The peak gain is 20.1 dBi. Due to its attractive properties of miniaturization, broadband, and high gain, the proposed antenna array could be applied to millimeter-wave wireless communication systems.
ABSTRACT
Mitochondrial division inhibitor-1 (mdivi-1), a non-specific inhibitor of Drp1-dependent mitochondrial fission, is neuroprotective in numerous preclinical disease models. These include rodent models of Alzheimer's disease and ischemic or traumatic brain injury. Among its Drp1-independent actions, the compound was found to suppress mitochondrial Complex I-dependent respiration but with less resultant mitochondrial reactive oxygen species (ROS) emission compared with the classical Complex I inhibitor rotenone. We employed two different methods of quantifying Trolox-equivalent antioxidant capacity (TEAC) to test the prediction that mdivi-1 can directly scavenge free radicals. Mdivi-1 exhibited moderate antioxidant activity in the 2,2'-azinobis (3-ethylbenzothiazoline 6-sulfonate) (ABTS) assay. Half-maximal ABTS radical depletion was observed at ~25 µM mdivi-1, equivalent to that achieved by ~12.5 µM Trolox. Mdivi-1 also showed antioxidant activity in the α, α-diphenyl-ß-picrylhydrazyl (DPPH) assay. However, mdivi-1 exhibited a reduced capacity to deplete the DPPH radical, which has a more sterically hindered radical site compared with ABTS, with 25 µM mdivi-1 displaying only 0.8 µM Trolox equivalency. Both assays indicate that mdivi-1 possesses biochemical antioxidant activity but with modest potency relative to the vitamin E analog Trolox. Future studies are needed to evaluate whether the ability of mdivi-1 to directly scavenge free radicals contributes to its mechanisms of neuroprotection.
ABSTRACT
The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.
Subject(s)
Epilepsy, Temporal Lobe , Epilepsy , Hippocampus , Humans , Magnetic Resonance Imaging , Neurogenesis , SeizuresABSTRACT
Stem cell dysfunction drives many age-related disorders. Identifying mechanisms that initially compromise stem cell behavior represent early targets to promote tissue function later in life. Here, we pinpoint multiple factors that disrupt neural stem cell (NSC) behavior in the adult hippocampus. Clonal tracing showed that NSCs exhibit asynchronous depletion by identifying short-term NSCs (ST-NSCs) and long-term NSCs (LT-NSCs). ST-NSCs divide rapidly to generate neurons and deplete in the young brain. Meanwhile, multipotent LT-NSCs are maintained for months but are pushed out of homeostasis by lengthening quiescence. Single-cell transcriptome analysis of deep NSC quiescence revealed several hallmarks of molecular aging in the mature brain and identified tyrosine-protein kinase Abl1 as an NSC aging factor. Treatment with the Abl inhibitor imatinib increased NSC activation without impairing NSC maintenance in the middle-aged brain. Our study indicates that hippocampal NSCs are particularly vulnerable and adaptable to cellular aging.
Subject(s)
Neural Stem Cells , Neurogenesis , Brain , Cellular Senescence , HippocampusABSTRACT
This paper presents a novel J band (220-325 GHz) MEMS switch design. The equivalent circuits, the major parameters, capacitance, inductance and resistance in the circuit were extracted and calculated quantitatively to carry out the radio frequency analysis. In addition, the mechanical property of the switch structure is analyzed, and the switching voltage is obtained. With the designed parameters, the MEMS switch is fabricated. The measurement results are in good agreement with simulation results, and the switch is actuated under a voltage of ~30 V. More importantly, the switch has achieved a low insertion loss of ~1.2 dB at 220 GHz and <~4 dB from 220 GHz to 270 GHz in the "UP" state, and isolation of ~16 dB from 220 GHz to 320 GHz in the "DOWN" state. Such switch shows great potential in the integration for terahertz components.
ABSTRACT
OBJECTIVES: Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. METHODS: The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. RESULTS: There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. CONCLUSION: Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.