In recent years, 2D layered materials, including graphene, topological insulators, transition metal dichalcogenides, black phosphorus, MXenes, graphitic carbon nitride, and metal‐organic frameworks, ...have attracted considerable interest due to their potential applications in the fields of physics, chemistry, biology, and energy. Their rise in the field of nonlinear photonics began around 2009 and has become an important research direction. Here, the synthesis techniques, nonlinear optical properties, integration strategies, and device applications of layered materials are reviewed. In terms of nonlinear optical properties, the focus is on saturable absorption and Kerr nonlinearity. On this basis, their applications in various pulsed lasers, including fiber lasers, solid‐state lasers, waveguide lasers, and related nonlinear optical phenomenon, are summarized. In addition, novel optical devices using layered materials, such as optical modulators, optical polarizers, optical switchers, and even all‐optical device, are also involved. It is believed that the development of 2D layered materials in the field of photonics will continue to deepen, thus laying a good foundation for its practical application.
Synthesis techniques, nonlinear optical properties, integration strategies, and device applications of 2D layered materials are reviewed. Especially, the current state of the art in the application, both in various mode‐locked/Q‐switched lasers and related nonlinear optical phenomenon and even novel optical devices, such as modulators, polarizers, isolators, all‐optical devices, and sensors, are summarized.
After decades of molecular phylogenetic studies, the deep phylogeny of gymnosperms has not been resolved, and the phylogenetic placement of Gnetales remains one of the most controversial issues in ...seed plant evolution. To resolve the deep phylogeny of seed plants and to address the sources of phylogenetic conflict, we conducted a phylotranscriptomic study with a sampling of all 13 families of gymnosperms and main lineages of angiosperms. Multiple datasets containing up to 1 296 042 sites across 1308 loci were analysed, using concatenation and coalescence approaches. Our study generated a consistent and well-resolved phylogeny of seed plants, which places Gnetales as sister to Pinaceae and thus supports the Gnepine hypothesis. Cycads plus
is sister to the remaining gymnosperms. We also found that Gnetales and angiosperms have similar molecular evolutionary rates, which are much higher than those of other gymnosperms. This implies that Gnetales and angiosperms might have experienced similar selective pressures in evolutionary histories. Convergent molecular evolution or homoplasy is partially responsible for the phylogenetic conflicts in seed plants. Our study provides a robustly reconstructed backbone phylogeny that is important for future molecular and morphological studies of seed plants, in particular gymnosperms, in the light of evolution.
Food-grade colloidal particles and complexes, which are formed via modulation of the noncovalent interactions between macromolecules and natural small molecules, can be developed as novel functional ...ingredients in a safe and sustainable way. For this study was prepared a novel zein/tannic acid (TA) complex colloidal particle (ZTP) based on the hydrogen-bonding interaction between zein and TA in aqueous ethanol solution by using a simple antisolvent approach. Pickering emulsion gels with high oil volume fraction (φoil > 50%) were successfully fabricated via one-step homogenization. Circular dichroism (CD) and small-angle X-ray scattering (SAXS) measurements, which were used to characterize the structure of zein/TA complexes in ethanol solution, clearly showed that TA binding generated a conformational change of zein without altering their supramolecular structure at pH 5.0 and intermediate TA concentrations. Consequently, the resultant ZTP had tuned near neutral wettability (θow ∼ 86°) and enhanced interfacial reactivity, but without significantly decreased surface charge. These allowed the ZTP to stabilize the oil droplets and further triggered cross-linking to form a continuous network among and around the oil droplets and protein particles, leading to the formation of stable Pickering emulsion gels. Layer-by-layer (LbL) interfacial architecture on the oil–water surface of the droplets was observed, which implied a possibility to fabricate hierarchical interface microstructure via modulation of the noncovalent interaction between hydrophobic protein and natural polyphenol.
The degeneration of dopaminergic neurons is a major contributor to the pathogenesis of mid‐brain disorders. Clinically, cell therapeutic solutions, by increasing the neurotransmitter dopamine levels ...in the patients, are hindered by low efficiency and/or side effects. Here, a strategy using electromagnetized nanoparticles to modulate neural plasticity and recover degenerative dopamine neurons in vivo is reported. Remarkably, electromagnetic fields generated by the nanoparticles under ultrasound stimulation modulate intracellular calcium signaling to influence synaptic plasticity and control neural behavior. Dopaminergic neuronal functions are reversed by upregulating the expression tyrosine hydroxylase, thus resulting in ameliorating the neural behavioral disorders in zebrafish. This wireless tool can serve as a viable and safe strategy for the regenerative therapy of the neurodegenerative disorders.
Degeneration of dopaminergic neurons is a most common age‐related disorder in the central nervous system. A break‐through idea using electromagnetized nanoparticles to mediate neural plasticity and recover the functions of degenerative dopaminergic neurons in the midbrain of a Parkinson's disease animal model is conceived. A significant advance in remote and regenerative cell therapy of the neurodegenerative diseases is thus provided.
Non-invasive sonodynamic therapy (SDT) was developed because of its advantages of high penetration depth and low side effects; however, tumor hypoxia greatly restricts its therapeutic effect. In this ...study, we aimed to develop ideal O2 self-supplementing nanoparticles for imaging-guided enhanced sonodynamic therapy of tumors with the adept coalescence of biology with nanotechnology. Methods: Based on the natural enzyme system of red blood cells (RBC), biomimetic nanoparticles (QD@P)Rs were fabricated by encapsulating Ag2S quantum dots (QD) in RBC vesicle membranes. The anti-tumor drug PEITC was employed to increase the intracellular H2O2 concentration in tumor cells. Results: In vitro and in vivo experiments demonstrated excellent biocompatibility and prolonged blood circulation of (QD@P)Rs. Following oral administration of PEITC in mice to improve the H2O2 concentration, the enzyme in the nanoprobe catalyzed endogenous H2O2 to increase O2 content and effectively alleviate tumor hypoxia. Triggered by ultrasound under the guidance of fluorescence imaging, (QD@P)Rs generated reactive oxygen species (ROS) to induce tumor cell death, and the increased content of O2 significantly enhanced the effect of SDT. Conclusion: Ag2S QDs were used, for the first time, as a sonosensitizer in the SDT field. In this study, we integrated the advantages of the natural enzyme system and SDT to develop a novel approach for effective non-invasive treatment of cancer.
A cationic sliver-triazolate MOF displays an efficient function of Cr(VI) removal via anion exchange.
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•The anion-exchange pattern of the silver-triazolate MOF has been ...established.•Hofmeister bias has been invoked to explain the experimental results.•The MOF possesses a good function of Cr(VI)-removal from water.
Gram-scale synthesis of a silver-triazolato framework − {Ag8(tz)6(NO3)2·6H2O}n (1-NO3; tz−=3,5-diphenyl-1,2,4-triazolate) − has been achieved, enabling the systematic investigation of its anion-exchange properties. Our experimental results show that the anion-exchange pattern of 1-NO3 conforms to the so-called Hofmeister bias, which has been correlated to the hydrophobic nature of the MOF pores, and can be understood by considering the difference between the hydration energies of the exchanging anions. Furthermore, 1-NO3 displays a fast, efficient, and reversible adsorption of HCrO4− (via anion-exchange) from Cr(VI)-containing aqueous solution (Qmax=37.0 Cr mg/g, 303K), rendering it a promising prototype of a recyclable MOF for Cr(VI) removal.
Although several nucleo(s)tide analogs are available for treatment of HBV infection, long‐term treatment with these drugs can lead to the emergence of drug‐resistant viruses. Recent HIV‐1 studies ...suggest that combination therapies using nucleo(s)tide reverse transcriptase inhibitors (NRTIs) and non‐nucleo(s)tide reverse transcriptase inhibitors (NNRTIs) could drastically inhibit the viral genome replication of NRTI‐resistant viruses. In order to carry out such combinational therapy against HBV, several new NRTIs and NNRTIs should be developed. Here, we aimed to identify novel NNRTIs targeting the HBV polymerase terminal protein (TP)‐reverse transcriptase (RT) (TP‐RT) domain, which is a critical domain for HBV replication. We expressed and purified the HBV TP‐RT with high purity using an Escherichia coli expression system and established an in vitro ε RNA‐binding assay system. Then, we used TP‐RT in cell‐free assays to screen candidate inhibitors from a chemical compound library, and identified two compounds, 6‐hydroxy‐DL‐DOPA and N‐oleoyldopamine, which inhibited the binding of ε RNA with the HBV polymerase. Furthermore, these drugs reduced HBV DNA levels in cell‐based assays as well by inhibiting packaging of pregenome RNA into capsids. The novel screening system developed herein should open a new pathway the discovery of drugs targeting the HBV TP‐RT domain to treat HBV infection.
HBVpol; TP‐spacer‐RT specifically binds with HBV packaging signal epsilon.
Abstract
With speeding up development of 5 G chips, high-efficient thermal structure and precise management of tremendous heat becomes a substantial challenge to the power-hungry electronics. Here, ...we demonstrate an interpenetrating architecture of electrocaloric polymer with highly thermally conductive pathways that achieves a 240% increase in the electrocaloric performance and a 300% enhancement in the thermal conductivity of the polymer. A scaled-up version of the device prototype for a single heat spot cooling of 5 G chip is fabricated utilizing this electrocaloric composite and electromagnetic actuation. The continuous three-dimensional (3-D) thermal conductive network embedded in the polymer acts as nucleation sites of the ordered dipoles under applied electric field, efficiently collects thermal energy at the hot-spots arising from field-driven dipolar entropy change, and opens up the high-speed conduction path of phonons. The synergy of two components, thus, tackles the challenge of sluggish heat dissipation of the electroactive polymers and their contact interfaces with low thermal conductivity, and more importantly, significantly reduces the electric energy for switching the dipolar states during the electrocaloric cycles, and increases the manipulable entropy at the low fields. Such a feasible solution is inevitable to the precisely fixed-point thermal management of next-generation smart microelectronic devices.
Angiosperms and gymnosperms are two major groups of extant seed plants. It has been suggested that gymnosperms lack FLOWERING LOCUS T (FT), a key integrator at the core of flowering pathways in ...angiosperms.
Taking advantage of newly released gymnosperm genomes, we revisited the evolutionary history of the plant phosphatidylethanolamine-binding protein (PEBP) gene family through phylogenetic reconstruction. Expression patterns in three gymnosperm taxa and heterologous expression in Arabidopsis were studied to investigate the functions of gymnosperm FT-like and TERMINAL FLOWER 1 (TFL1)-like genes.
Phylogenetic reconstruction suggests that an ancient gene duplication predating the divergence of seed plants gave rise to the FT and TFL1 genes. Expression patterns indicate that gymnosperm TFL1-like genes play a role in the reproductive development process, while GymFT1 and GymFT2, the FT-like genes resulting from a duplication event in the common ancestor of gymnosperms, function in both growth rhythm and sexual development pathways. When expressed in Arabidopsis, both spruce FT-like and TFL1-like genes repressed flowering.
Our study demonstrates that gymnosperms do have FT-like and TFL1-like genes. Frequent gene and genome duplications contributed significantly to the expansion of the plant PEBP gene family. The expression patterns of gymnosperm PEBP genes provide novel insight into the functional evolution of this gene family.
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