Hydrogen‐bonded organic frameworks (HOFs) possess various merits, such as high porosity, tunable structure, facile modification, and ready regeneration. These properties have yet to be explored in ...the context of new functional HOF materials. The facile and inexpensive electrophoretic deposition (EPD) method applied in this study generated a transparent HOF film at room temperature in just 2 min and is applicable to other HOFs. The resulting film exhibited reversible electrochromism with the advantage of long cycle life (>500 cycles). More strikingly, this all‐organic film could be readily regenerated (through rinsing with DMF and redeposition) and showed tunable electrochromic behavior (through low‐cost postsynthetic modification) with the ability to undergo successive color changes, which is difficult to achieve with conventional electrochromic materials. An electrochromic device was manufactured to further demonstrate the application potential of the film.
Facile and efficient electrophoretic deposition was used to prepare an electrochromic hydrogen‐bonded organic framework film (see picture), which exhibited reversible electrochromism with the advantages of long cycle life, ready regeneration, and tunable electrochromic behavior. An electrochromic device was manufactured with the film to further demonstrate its application potential.
Taylor series is accessible to all students and it is a useful mathematical tool to nonlinear equations. This paper shows it is extremely simple to solve approximately the well-known Lane–Emden ...equation.
Electrochromic technology offers exciting opportunities for smart applications such as energy‐saving and interactive systems. However, achieving dual‐band regulation together with the multicolor ...function is still an unmet challenge for electrochromic devices. Herein, an ingenious electrochromic strategy based on reversible manganese oxide (MnO2) electrodeposition, different from traditional ion intercalation/deintercalation‐type electrochromic materials is proposed. Such a deposition/dissolution‐based MnO2 brings an intriguing electrochromic feature of dual‐band regulation for the ultraviolet (UV) and visible lights with high optical modulation (93.2% and 93.6% at 400 and 550 nm, respectively) and remarkable optical memory. Moreover, a demonstrative smart window assembled by MnO2 and Cu electrodes delivers the electrochromic properties of effective dual‐band regulation accompanied by multicolor changes (transparent, yellow, and brown). The robust redox deposition/dissolution process endows the MnO2‐based electrochromic device with excellent rate capability and an areal capacity of 570 mAh m−2 at 0.1 mA cm−2. It is believed that the metal oxide‐based reversible electrodeposition strategy would be an attractive and promising electrochromic technology and provide a train of thought for the development of multifunctional electrochromic devices and applications.
A novel electrochromic strategy based on reversible manganese oxide (MnO2) electrodeposition is demonstrated, in which the robust deposition/dissolution process endows the MnO2‐based device with selective dual‐band regulation in ultraviolet–visible regions, remarkable optical memory, multicolor changes (transparent, yellow, and brown), in addition to high rate capability and superior energy storage capacity.
Index modulation concept has attracted considerable research interest in the past few years. As a realization of index modulation in the frequency domain, orthogonal frequency division multiplexing ...with index modulation (OFDM-IM) has recently been proposed, which conveys information bits through both the subcarrier activation patterns and the amplitude phase modulation constellation points. This paper proposes two enhanced OFDM-IM schemes aimed at achieving higher spectral efficiency and diversity gain, respectively. The first one, termed OFDM with hybrid in-phase/quadrature index modulation (OFDM-HIQ-IM), explores the I- and Q- dimensions jointly for index modulation, allowing transmission of more index modulation bits in each subcarrier group. The second one, termed linear constellation precoded OFDM-IQ-IM (LP-OFDM-IQ-IM), spreads information symbols across two adjacent active subcarriers through linear constellation precoding to harvest additional diversity gain. By maximizing the minimum squared Euclidean distance, two different realizations of LP-OFDM-IQ-IM are derived, which leads to a rotated and a diamond-shaped constellation, respectively. The proposed OFDM-HIQ-IM and LP-OFDM-IQ-IM, as revealed by both theoretical analyses and computer simulations, enable low-complexity detection and exhibit superior error rate performance over the existing OFDM-IM schemes.
NOMA is a promising radio access technique for next-generation wireless networks. In this article, we investigate the NOMA-based cooperative relay network. We begin with an introduction of the ...existing relay-assisted NOMA systems by classifying them into three categories: uplink, downlink, and composite architectures. Then we discuss their principles and key features, and provide a comprehensive comparison from the perspective of spectral efficiency, energy efficiency, and total transmit power. A novel strategy called hybrid power allocation is further discussed for the composite architecture, which can reduce the computational complexity and signaling overhead at the expense of marginal sum rate degradation. Finally, major challenges, opportunities, and future research trends for the design of NOMA-based cooperative relay systems with other techniques are also highlighted to provide insights for researchers in this field.
N
-methyladenosine (m6A) RNA methylation contributes to the cancer stem cell (CSC) phenotype through regulating gene expression. YTHDF2, an m6A reader, was shown to be associated with hepatocellular ...carcinoma (HCC) patient prognosis. However, the effect of YTHDF2 on liver CSC and cancer metastasis and the molecular mechanism of this effect have not been documented. Here, we show that YTHDF2 expression is negatively correlated with HCC patient survival in both data from the Cancer Genome Atlas (TCGA) database and clinical data from our center. By detecting CD133
cells and carrying out sphere culture assays, we found that knockdown of YTHDF2 led to impaired stemness in Hep3B and Huh7 cells. In contrast, overexpression of YTHDF2 increased the CSC phenotype. Mechanistically, the knockdown and overexpression of YTHDF2 in liver cancer cells resulted in decreased and increased m6A levels in the 5'-untranslated region (UTR) of OCT4 mRNA, respectively, leading to decreased and increased OCT4 protein expression, respectively. A luciferase activity assay showed that mutation of the corresponding m6A methylation sequence in the 5'-UTR of OCT4 mRNA caused significantly decreased gene expression, suggesting a role for YTHDF2-dependent m6A methylation in protein translation. Polysome profiling results also indicated the knockdown and overexpression of YTHDF2 could decrease and increase OCT4 translation, respectively. In particular, overexpression of OCT4 rescued the impaired stemness caused by YTHDF2 depletion, which confirmed the effect of YTHDF2 on CSC phenotype is dependent on OCT4. In vivo, the loss of YTHDF2 reduced tumor burden and inhibited lung metastasis following orthotopic transplantation in nude mice. Last, we demonstrated that YTHDF2 expression is positively correlated with OCT4 expression and m6A levels in the 5'-UTR of OCT4 mRNA in clinical HCC specimens. In conclusion, YTHDF2 promotes the CSC liver phenotype and cancer metastasis by modulating the m6A methylation of OCT4 mRNA.
•The Hamilton principle is used to derive the governing equation for transverse vibration of a reinforced concrete pillar.•A Boussinesq-like equation is obtained and its resonance-like and solitary ...solutions are discussed.•A fractal Boussinesq equation is discussed for vibration design by taking into account the porous structure of concrete.•The morphology of a travelling wave can be effectively controlled by the fractal dimensions of fractal concrete.
An approximate Hamilton principle is established for the transverse vibration of a reinforced concrete pillar by considering the dissipation energy, and a generalized Boussinesq equation is obtained. The exp-function method is adopted to solve the equation, and its solution properties are discussed and elucidated, including solitary solution, blowup solution, and discontinuous solution. In order to study the effect of a porous structure on the vibration property, fractal calculus is used to derive the fractal Boussinesq equation, and a fractal variational principle is also established. The fractal model confers many attractive properties, which can not be revealed by the traditional protocol. The effect of the nanofiber-reinforced concrete structure on its wave morphology is discussed and illustrated. A blowup solution can be converted into a flat solution by adjusting the value of the fractal derivative order. The paper sheds new light on the design of reinforced concrete pillars to avoid vibration damage.
The laboratory axolotl (Ambystoma mexicanum) is widely used in biological research. Recent advancements in genetic and molecular toolkits are greatly accelerating the work using axolotl, especially ...in the area of tissue regeneration. At this juncture, there is a critical need to establish gene and transgenic nomenclature to ensure uniformity in axolotl research. Here, we propose guidelines for genetic nomenclature when working with the axolotl.
Key Findings
Axolotl has become the favored model organism for tetrapod tissue regeneration. We propose here gene and transgenic nomenclature guidelines that will allow researchers to communicate it more efficiently.
In this paper, we study the performance of a downlink non-orthogonal multiple access-based cooperative relay system with a single relay over Nakagami-m fading channels, where both decode-and-forward ...(DF) and amplify-and-forward (AF) protocols are considered. We assume that only statistical channel state information is available to the system and used to determine the decoding order of cell-edge users' data. For DF relaying, both ergodic sum rate and outage probability are solved in closed form. For AF relaying, closed-form asymptotic ergodic sum rate and outage probability are provided. Numerical results verify the accuracy of the analysis and demonstrate that the DF protocol significantly outperforms the AF one in terms of ergodic sum rate even the channel's near-far effect weakens. In addition, the DF protocol exhibits better outage performance than the AF one at low signal-to-noise ratio (SNR), though the superiority becomes negligible with the increasing SNR.
Salamanders serve as important tetrapod models for developmental, regeneration and evolutionary studies. An extensive molecular toolkit makes the Mexican axolotl (Ambystoma mexicanum) a key ...representative salamander for molecular investigations. Here we report the sequencing and assembly of the 32-gigabase-pair axolotl genome using an approach that combined long-read sequencing, optical mapping and development of a new genome assembler (MARVEL). We observed a size expansion of introns and intergenic regions, largely attributable to multiplication of long terminal repeat retroelements. We provide evidence that intron size in developmental genes is under constraint and that species-restricted genes may contribute to limb regeneration. The axolotl genome assembly does not contain the essential developmental gene Pax3. However, mutation of the axolotl Pax3 paralogue Pax7 resulted in an axolotl phenotype that was similar to those seen in Pax3
and Pax7
mutant mice. The axolotl genome provides a rich biological resource for developmental and evolutionary studies.
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