Choline acetyltransferase neurons in the vertical diagonal band of Broca (vChATs) degenerate in the early stage of Alzheimer's disease (AD). Here, we report that vChATs directly innervate newly ...generated immature neurons (NGIs) in the dorsal hippocampus (dNGIs) of adult mice and regulate both the dNGIs survival and spatial pattern separation. In a mouse model that exhibits amyloid-β plaques similar to AD patients, cholinergic synaptic transmission, dNGI survival and spatial pattern separation are impaired. Activation of vChATs with theta burst stimulation (TBS) that alleviates the decay in cholinergic synaptic transmission effectively protects against spatial pattern separation impairments in the AD mice and this protection was completely abolished by inhibiting the dNGIs survival. Thus, the impairments of pattern separation-associated spatial memory in AD mice are in part caused by degeneration of cholinergic synaptic transmission that modulates the dNGIs survival.
Much attention has been paid to imidoyl radical-involved reactions in recent years. As a divergent reactive intermediate, imidoyl radicals are used for the synthesis of functionalized heterocycles, ...nitriles, imines, amines,
etc
. This review is intended to highlight some recent progress in the past decade.
This review discusses the recent progress in imidoyl radical-involved reactions including the synthesis of functionalized heterocycles, nitriles, imines, amines,
etc
.
The previously reported hybrid orthogonal frequency division multiplexing-digital filter multiple access (OFDM-DFMA) PONs offer promising solutions for seamlessly converging optical and mobile ...networks for 5G. However, the hybrid OFDM-DFMA PONs based on intensity-modulation and direct-detection (IMDD) convey double sideband (DSB) signals at different sub-wavelengths, this halves the spectral efficiency and signal transmission capacity. In this article, hybrid single sideband (SSB) OFDM-DFMA PONs are proposed and explored, for the first time, where multiple SSB OFDM channels produced without employing the Hilbert transform operation are multiplexed using orthogonal digital filtering in ONUs, and demultiplexed/demodulated by a single FFT operation in OLT without incorporating matching filters. It is shown that similar to the DSB PON, the proposed SSB PON has excellent robustness against digital filter characteristic variations and channel interferences. More importantly, it decreases peak-to-average power ratios (PAPRs) of digitally-filtered OFDM signals by >2 dB, thus leading to >2 dB reductions in optimum signal clipping ratio and >1 bit reductions in minimum required DAC/ADC resolution bits. For fixed spectral bandwidths, the SSB PON almost doubles the maximum upstream transmission capacity without considerably degrading its differential ONU optical launch power dynamic range compared to the DSB PON. While for fixed upstream signal transmission capacities, compared to the DSB PON, the SSB PON not only halves the overall signal transmission bandwidth, but also leads to >2.5 dB (>1.2 dB) improvements in power budget (differential optical launch power dynamic range for ONUs locating at high frequency regions).
This review mainly focuses on the topics related to metal complex based delayed fluorescence (DF) materials including their molecular design principle, photophysical studies, as well as their ...performance in the device settings. Due to the choice of various metal ions and metal complex system, metal based DF materials can be categorized into four major material classes based on their emission mechanisms at room temperature: (I) TADF materials exhibiting both fluorescence and DF; (II) TADF materials exhibiting DF only; (III) metal assisted delayed fluorescence (MADF) materials exhibiting both phosphorescence and DF; (IV) DF materials exhibiting fluorescence, phosphorescence and DF.
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•This review focuses on recent progress of metal complex based delayed fluorescence materials.•Their molecular design principle, photophysical studies, as well as the device performance have been summarized.•These materials can be categorized into four major material classes based on their emission mechanisms.•An outlook on the future development of metal complex based delayed fluorescence materials is given.
Luminescent materials play an important role in making solid state white light-emitting diodes (w-LEDs) more affordable home lighting applications. To realize the next generation of solid-state ...w-LEDs with high color-rendering index (CRI), the discovery of broad band and long emission wavelength luminescent materials is an urgent mission. Regarding this, the oxonitridosilicate Y3Si5N9O with a high nitrogen concentration should be a suitable host material to achieve those promising luminescent properties. In this work, a phase-pure Ce3+-doped Y3Si5N9O was successfully synthesized through the carbothermal reduction and nitridation method. Y3Si5N9O:Ce3+ shows an emission maximum at 620 nm and an extremely broad emission band with a full-width at half-maximum (fwhm) of 178 nm. The electronic and crystal structure calculations indicate an indirect band gap of 2.6 eV (experimental value: 4.0 eV), and identify two Ce3+ sites with different local environments that determine the luminescence properties. The orange-emitting phosphor has the absorption, internal and external quantum efficiencies of 89.5, 17.2, and 15.6% under 450 nm excitation, respectively. The valence state of Ce, cathodoluminescence, decay time, and thermal quenching of the phosphor were also investigated to understand the structure–property relationships.
This article proposes a novel method for estimating the high-frequency (HF) incremental dq -axis and cross-coupling inductances of interior permanent magnet synchronous machines based on both the HF ...rotating and pulsating voltage injection techniques. It mainly includes three HF voltage injection stages, i.e., a HF rotating voltage injection in the stationary reference frame, and a pulsating voltage injection in the d -axis and a pulsating voltage injection in the q -axis of the synchronous rotating reference frame. Compared with conventional estimation methods which either use only rotating voltage injection, or use only pulsating voltage injections in the dq -axes, the proposed method neither requires the closed-loop position estimator to obtain the offset angle caused by the cross-coupling effect nor is sensitive to the delay effects caused by digital filters and voltage synthesis. The estimated results obtained by the proposed method show a good agreement with those by finite element analysis and are also compared with those obtained by the conventional methods.
Dual three-phase (DTP) permanent magnet synchronous machine (PMSM) systems exhibit high current harmonics due to low impedance to voltage disturbance such as inverter voltage errors and back-EMF ...harmonics. This article proposes a concept of virtual multi three-phase systems to achieve independent regulation of the current harmonics in a DTP PMSM system. The virtual multi three-phase currents are first reconstructed by appropriately shifting the phase of original physical DTP currents, and then decomposed with the help of vector space decomposition techniques. As a result, the fundamental and the major current harmonics, i.e., the 5th, 7th, 11th, and 13th, can be completely separated in several isolated subspaces, where the independent current control loops can be easily designed and implemented. Compared with existing methods, the steady-state and dynamic-state performance of current harmonic regulation are enhanced by the proposed virtual multi three-phase systems and the effectiveness is validated by experimental.
An
n
-dimensional bijective connection network (in brief, BC network), denoted by
X
n
, is an
n
-regular graph with 2
n
nodes and
n
2
n
−1
edges. Hypercubes, crossed cubes, twisted cubes, and Möbius ...cubes all belong to the class of BC networks (Fan and He in Chin. J. Comput. 26(1):84–90,
2003
). We prove that the super connectivity of
X
n
is 2
n
−2 for
n
≥3 and the conditional diagnosability of
X
n
is 4
n
−7 for
n
≥5. As a corollary of this result, we obtain the super connectivity and conditional diagnosability of the hypercubes, twisted cubes, crossed cubes, and Möbius cubes.
Intracerebral haemorrhage (ICH) is a severe neurological disorder caused by bleeding within the brain tissue. Inflammation has been implicated in ICH pathogenesis and is a potential therapeutic ...target for ICH. Haemin, an activator of haem oxygenase‐1 (HO‐1), rapidly increases HO‐1 protein expression and activity and has been shown to distinctly affect anti‐inflammatory functions after central nervous system (CNS) injury. However, less is known about the mechanisms that underlie the anti‐inflammatory effects of haemin in aged rats post‐ICH. Here, we performed microarray analysis to identify miRNAs that respond strongly to HO‐1 regulation in ICH rats and found that miR‐21‐5p induced the most significant change. Using Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment and Gene Ontology (GO) analysis, we focused on dual‐specificity phosphatase 8 (DUSP8) from the predicted miR‐21‐5p targets. Luciferase reporter assays confirmed that miR‐21‐5p bound directly to DUSP8. MiR‐21‐5p upregulation in vitro downregulated DUSP8 expression. Importantly, intracerebroventricularly injecting antagomir for miR‐21‐5p (A‐miR‐21‐5p), which was used to inhibit miR‐21‐5p in aged ICH rats, significantly reduced the neurological defects, repaired cognitive impairment, alleviated blood–brain barrier (BBB) permeability, inhibited neuronal apoptosis posthaemorrhage and accelerated haematoma absorption. In addition, serum miR‐21‐5p levels were notably elevated in patients relative to healthy individuals and were correlated with National Institutes of Health Stroke Scale (NIHSS) scores and clinical outcomes. In summary, A‐miR‐21‐5p increased HO‐1 expression in cerebral haematomas, thus eliciting the DUSP8‐modulated perifocal neuroprotective effect of haemin. MiR‐21‐5p with haemin therapy may be a potential therapy post‐ICH.
In the ICH brain, the miR‐21‐5p‐DUSP8‐ERK1/2 signalling pathway mediates the hemin‐induced elevation of HO‐1 activity to attenuate the ICH‐induced oxidative and inflammatory injury.
An efficient one‐pot assembly of all‐carbon spiro‐oxindole compounds from non‐oxindole‐based materials has been developed through a palladium‐catalyzed asymmetric Heck/carbonylative lactonization and ...lactamization sequence. Diversified spirooxindole γ‐and δ‐lactones/lactams were accessed in high yields with good to excellent enantioselectivities (up to 99 % ee) under mild reaction conditions. The natural product coixspirolactam A was conveniently synthesized by applying the current methodology, and thus its absolute configuration was elucidated for the first time. Asymmetric synthesis of an effective CRTH2 receptor antagonist has also been demonstrated utilizing this method in the key step.
An efficient one‐pot assembly of all‐carbon spiro‐oxindole compounds from non‐oxindole‐based materials has been developed using a palladium‐catalyzed asymmetric Heck/carbonylative lactonization and lactamization sequence. Diversified spirooxindole γ‐and δ‐lactones/lactams were accessed in high yields with good to excellent enantioselectivities under mild reaction conditions.
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