Mechanical energy in vivo could be harvested by BD-TENG in a designed time frame.

Summary The mechanisms underlying Zika virus (ZIKV)-related microcephaly and other neurodevelopment defects remain poorly understood. Here, we describe the derivation and characterization, including single-cell RNA-seq, of neocortical and spinal cord neuroepithelial stem (NES) cells to model early human neurodevelopment and ZIKV-related neuropathogenesis. By analyzing human NES cells, organotypic fetal brain slices and a ZIKV-infected micrencephalic brain, we show that ZIKV infects both neocortical and spinal NES cells and their fetal homolog, radial glial cells (RGCs), causing disrupted mitoses, supernumerary centrosomes, structural disorganization and cell death. ZIKV infection of NES cells and RGCs causes centrosomal depletion and mitochondrial sequestration of phospho-TBK1 during mitosis. We also found that nucleoside analogs inhibit ZIKV replication in NES cells, protecting them from ZIKV-induced pTBK1 relocalization and cell death. We established a model system of human neural stem cells to reveal cellular and molecular mechanisms underlying neurodevelopmental defects associated with ZIKV infection and its potential treatment.

IMPORTANCEPer the World Health Organization 2016 integrative classification, newly diagnosed glioblastomas are separated into isocitrate dehydrogenase gene 1 or 2 (IDH)-wild-type and IDH-mutant subtypes, with median patient survival of 1.2 and 3.6 years, respectively. Although maximal resection of contrast-enhanced (CE) tumor is associated with longer survival, the prognostic importance of maximal resection within molecular subgroups and the potential importance of resection of non-contrast-enhanced (NCE) disease is poorly understood.OBJECTIVE To assess the association of resection of CE and NCE tumors in conjunction with molecular and clinical information to develop a new road map for cytoreductive surgery.

The two-dimensional (2D) perovskites stabilized by alternating cations in the interlayer space (ACI) define a new type of structure with different physical properties than the more common Ruddlesden−Popper counterparts. However, there is a lack of understanding of material crystallization in films and its influence on the morphological/optoelectronic properties and the final photovoltaic devices. Herein, we undertake in situ studies of the solidification process for ACI 2D perovskite (GA)(MA) n Pb n I 3n+1 (⟨n⟩ = 3) from ink to solid-state semiconductor, using solvent mixture of DMSO:DMF (1:10 v/v) as the solvent and link this behavior to solar cell devices. The in situ grazing-incidence X-ray scattering (GIWAXS) analysis reveals a complex journey through disordered sol−gel precursors, intermediate phases, and ultimately to ACI perovskites. The intermediate phases, including a crystalline solvate compound and the 2D GA 2 PbI 4 perovskite, provide a scaffold for the growth of the ACI perovskites during thermal annealing. We identify 2D GA 2 PbI 4 to be the key intermediate phase, which is strongly influenced by the deposition technique and determines the formation of the 1D GAPbI 3 byproducts and the distribution of various n phases of ACI perovskites in the final films. We also confirm the presence of internal charge transfer between different n phases through transient absorption spectroscopy. The high quality ACI perovskite films deposited from solvent mixture of DMSO:DMF (1:10 v/v) deliver a record power conversion efficiency of 14.7% in planar solar cells and significantly enhanced long-term stability of devices in contrast to the 3D MAPbI 3 counterpart.

light-emitting diodes, [5][6][7] and photodetectors, [8,9] because of their remarkable structural flexibility, tunability, and excellent stability compared with their 3D perovskite counterparts. [10][11][12] 2D perovskites are generally a class of quantum wells (QWs), including Ruddlesden-Popper (RP), [13][14][15] Dion-Jacobson (DJ), [16][17][18] and alternating cations in the interlayer space (ACI) perovskites. [19,20] The RP and DJ families adopt the general formulas A′ 2 A n−1 M n X 3n+1 and BA n−1 M n X 3n+1 , respectively, where A is a univalent organic cation: methylammonium (MA + ) or formamidinium (FA + ), A′ is a large univalent organic spacer cation like phenylethylammonium (PEA + ), [8,21] or butylammonium (BA + ), etc., [3,22] B is a divalent organic cation like 3-(aminomethyl)piperidinium (3AMP 2+ ) [10] or 1,3-propanediamine. [23] Much work on 2D perovskites to date has focused on the RP and DJ families. For example, it was found that the incorporation of large organic spacer cations leads to the formation of a QW structure with strong quantum confinement, which leads to a higher bandgap and large exciton binding energy. [14,[24][25][26][27] The RP and DJ perovskites feature poor charge dissociation and transportation within the bulk polycrystalline film, which significantly limits the power conversion efficiency (PCE) of solar cells. [28][29][30] To address the issue, a hot-casting strategy was developed to achieve preferential outof-plane alignment of RP QWs. [3] A systematic understanding of how RP perovskites are formed as well as the charge transfer between QWs were also demonstrated, which guided development of the dynamic control of the phase transformation during QWs growth for better compositional and orientation control. [31][32][33][34][35][36] Compositional and solvent engineering were also developed to fabricate high-quality DJ films with significantly improved charge transport. [23,37] For the RP and DJ families, much has been achieved toward a deep understanding of the relationships between molecular chemistry, crystal structure, film quality and optoelectronic properties, leading to outstanding PCEs of 15.42% and 13.3% for PR and DJ perovskite solar cells, respectively. [23,38] The hybrid halide ACI perovskites, which are derived from the oxide perovskite family, are a very new entry in the class 2D perovskites stabilized by alternating cations in the interlayer space (ACI) represent a very new entry as highly efficient semiconductors for solar cells approaching 15% power conversion efficiency (PCE). However, further improvements will require understanding of the nature of the films, e.g., the thickness distribution and charge-transfer characteristics of ACI quantum wells (QWs), which are currently unknown. Here, efficient control of the film quality of ACI 2D perovskite (GA)(MA) n Pb n I 3n+1 (〈n〉 = 3) QWs via incorporation of methylammonium chloride as an additive is demonstrated. The morphological and optoelectronic characterizations unambiguously demonstrate that the additive ena...

Perovskite solar cells based on two-dimensional/three-dimensional (2D/3D) hierarchical structure have attracted significant attention in recent years due to their promising photovoltaic performance and stability. However, obtaining a detailed understanding of interfacial mechanism at the 2D/3D heterojunction, for example, the ligand-chemistrydependent nature of the 2D/3D heterojunction and its influence on charge collection and the final photovoltaic outcome, is not yet fully developed. Here we demonstrate the underlying 3D phase templates growth of quantum wells (QWs) within a 2D capping layer, which is further influenced by the fluorination of spacers and compositional engineering in terms of thickness distribution and orientation. Better QW alignment and faster dynamics of charge transfer at the 2D/3D heterojunction result in higher charge mobility and lower charge recombination loss, largely explaining the significant improvements in charge collection and open-circuit voltage (V OC ) in complete solar cells. As a result, 2D/3D solar cells with a power-conversion efficiency of 21.15% were achieved, significantly higher than the 3D counterpart (19.02%). This work provides key missing information on how interfacial engineering influences the desirable electronic properties of the 2D/3D hierarchical films and device performance via ligand chemistry and compositional engineering in the QW layer.

The intrinsic electrical characteristics of different types of neurons are shaped by the K channels they express. From among the more than 70 different K channel genes expressed in neurons, Kv3 family voltage-dependent K channels are uniquely associated with the ability of certain neurons to fire action potentials and to release neurotransmitter at high rates of up to 1,000 Hz. In general, the four Kv3 channels Kv3.1-Kv3.4 share the property of activating and deactivating rapidly at potentials more positive than other channels. Each Kv3 channel gene can generate multiple protein isoforms, which contribute to the high-frequency firing of neurons such as auditory brain stem neurons, fast-spiking GABAergic interneurons, and Purkinje cells of the cerebellum, and to regulation of neurotransmitter release at the terminals of many neurons. The different Kv3 channels have unique expression patterns and biophysical properties and are regulated in different ways by protein kinases. In this review, we cover the function, localization, and modulation of Kv3 channels and describe how levels and properties of the channels are altered by changes in ongoing neuronal activity. We also cover how the protein-protein interaction of these channels with other proteins affects neuronal functions, and how mutations or abnormal regulation of Kv3 channels are associated with neurological disorders such as ataxias, epilepsies, schizophrenia, and Alzheimer's disease.

Quasi-two-dimensional (quasi-2D) perovskites have attracted attention because they have better stability than the 3D counterpart. However, power conversion efficiency of perovskite solar cells (PSCs) based on quasi-2D perovskite still lags behind those of the devices with 3D perovskites. We report here on a quasi-2D PSC employing an alternating cation perovskite of multidimensional hybrid GA­(MA) n Pb n I3n+1 (n = 5) with a PCE over 22%, which is enabled by post-treatment with amphoteric imidazolium iodide (ImI). An optimal concentration of ImI reduces trap density and enhances charge mobility because of the improved phase purity and crystallinity, which eventually leads to a PCE of 22.26% with an open-circuit voltage of 1.19 V, a fill factor of 0.81, and a short-circuit current density of 22.99 mA/cm2. Moreover, a light-soaking stability test shows that ca. 94% of initial PCE is maintained after over 1200 h. The PCE achieved in this work is a record among the reported quasi-2D PSCs.