Microdischarge‐Based Direct Current Triboelectric Nanogenerator via Accumulation of Triboelectric Charge in Atmospheric Condition

Direct conversion of mechanical energy into direct current (DC) by triboelectric nanogenerators (TENGs) is one of the desired features in terms of energy conversion efficiency. Although promising applications have been reported using the triboelectric effect, effective DC generating TENGs must be developed for practical purposes. Here, it is reported that continuous DC generation within a TENG itself, without any circuitry, can be achieved by triggering air breakdown via triboelectrification. It is demonstrated that DC generation occurs in combination with i) charge accumulation to generate air breakdown, ii) incident discharge (microdischarge), and iii) conveyance of charges to make the device sustainable. 10.5 mA m^?2 of output current and 10.6 W m^?2 of output power at 33 MΩ load resistance are achieved. Compared to the best DC generating TENGs ever reported, the TENG in this present study generates about 20 times larger root‐mean square current density.     

Activation of Ni Particles into Single Ni–N Atoms for Efficient Electrochemical Reduction of CO2

Electrochemical reduction of carbon dioxide (CO₂) to fuels and value‐added industrial chemicals is a promising strategy for keeping a healthy balance between energy supply and net carbon emissions. Here, the facile transformation of residual Ni particle catalysts in carbon nanotubes into thermally stable single Ni atoms with a possible NiN₃ moiety is reported, surrounded with a porous N‐doped carbon sheath through a one‐step nanoconfined pyrolysis strategy. These structural changes are confirmed by X‐ray absorption fine structure analysis and density functional theory (DFT) calculations. The dispersed Ni single atoms facilitate highly efficient electrocatalytic CO₂ reduction at low overpotentials to yield CO, providing a CO faradaic efficiency exceeding 90%, turnover frequency approaching 12 000 h^?1, and metal mass activity reaching about 10 600 mA mg^?1, outperforming current state‐of‐the‐art single atom catalysts for CO₂ reduction to CO. DFT calculations suggest that the Ni@N₃ (pyrrolic) site favors *COOH formation with lower free energy than Ni@N₄, in addition to exothermic CO desorption, hence enhancing electrocatalytic CO₂ conversion. This finding provides a simple, scalable, and promising route for the preparation of low‐cost, abundant, and highly active single atom catalysts, benefiting future practical CO₂ electrolysis.     

1D Stretchable Block Copolymer Yarn‐Based Energy Harvesters via BaTiO3/Polydimethylsiloxane Composite‐Carbon Conductive Ink

Highly stretchable self‐powered energy sources are promising options for powering diverse wearable smart electronics. However, commercially existing energy sources are disadvantaged by tensile strain limitations and constrained deformability. Here, 1D thread‐based highly stretchable triboelectric nanogenerators (HS‐TENGs), a crucial step toward overcoming these obstacles, are developed based on a highly stretchable coaxial‐type poly[styrene‐b‐isoprene‐b‐styrene] (SIS) elastomer tube. Carbon conductive ink is injected into the SIS tube as a core 1D electrode that remains almost unaffected even under 250% stretching because of its low Young's modulus. To further facilitate power generation by the HS‐TENG, a composite of barium titanate nanoparticles (BaTiO₃ NPs) and polydimethylsiloxane (PDMS) is coated on the initial SIS tube to modulate the dielectric permittivity based on variations in the BaTiO₃ NPs volume ratio. The 1D PDMS/BaTiO₃ NP composite‐coated SIS and a nylon 6‐coated 2D Ni–Cu conductive fabric are selected as triboelectric bottom and top layers, respectively. Woven HS‐TENGs textiles yield consistent power output under various extreme and harsh conditions, including folded, twisted, and washed states. These experimental findings indicate that the approach may become useful for realizing stretchable multifunctional power sources for various wearable electronics.     

Revisiting the Role of Conductivity and Polarity of Host Materials for Long‐Life Lithium–Sulfur Battery

Despite their high theoretical energy density and low cost, lithium–sulfur batteries (LSBs) suffer from poor cycle life and low energy efficiency owing to the polysulfides shuttle and the electronic insulating nature of sulfur. Conductivity and polarity are two critical parameters for the search of optimal sulfur host materials. However, their role in immobilizing polysulfides and enhancing redox kinetics for long‐life LSBs are not fully understood. This work has conducted an evaluation on the role of polarity over conductivity by using a polar but nonconductive platelet ordered mesoporous silica (pOMS) and its replica platelet ordered mesoporous carbon (pOMC), which is conductive but nonpolar. It is found that the polar pOMS/S cathode with a sulfur mass fraction of 80 wt% demonstrates outstanding long‐term cycle stability for 2000 cycles even at a high current density of 2C. Furthermore, the pOMS/S cathode with a high sulfur loading of 6.5 mg cm^?2 illustrates high areal and volumetric capacities with high capacity retention. Complementary physical and electrochemical probes clearly show that surface polarity and structure are more dominant factors for sulfur utilization efficiency and long‐life, while the conductivity can be compensated by the conductive agent involved as a required electrode material during electrode preparation. The present findings shed new light on the design principles of sulfur hosts towards long‐life and highly efficient LSBs.     

Short bZIP homologue of sulfur regulator Met4 from Ogataea parapolymorpha does not depend on DNA-binding cofactors for activating genes in sulfur starvation

The acquisition of sulfur from environment and its assimilation is essential for fungal growth and activities. Here, we describe novel features of the regulatory network of sulfur metabolism in Ogataea parapolymorpha, a thermotolerant methylotrophic yeast with high resistance to harsh environmental conditions. A short bZIP protein (OpMet4p) of O. parapolymorpha, displaying the combined structural characteristics of yeast and filamentous fungal Met4 homologues, plays a key role as a master regulator of cell homeostasis during sulfur limitation, but also its function is required for the tolerance of various stresses. Domain swapping analysis, combined with deletion analysis of the regulatory domains and genes encoding OpCbf1p, OpMet28p, and OpMet32p, indicated that OpMet4p does not require the interaction with these DNA-binding cofactors to induce the expression of sulfur genes, unlike the Saccharomyces cerevisiae Met4p. ChIP analysis confirmed the notion that OpMet4p, which contains a canonical bZIP domain, can bind the target DNA in the absence of cofactors, similar to homologues in other filamentous fungi. Collectively, the identified unique features of the O. parapolymorpha regulatory network, as the first report on the sulfur regulation by a short yeast Met4 homologue, provide insights into conservation and divergence of the sulfur regulatory networks among diverse ascomycetous fungi.     

Integrating comprehensive functional annotations to boost power and accuracy in gene-based association analysis

Gene-based association tests aggregate genotypes across multiple variants for each gene, providing an interpretable gene-level analysis framework for genome-wide association studies (GWAS). Early gene-based test applications often focused on rare coding variants; a more recent wave of gene-based methods, e.g. TWAS, use eQTLs to interrogate regulatory associations. Regulatory variants are expected to be particularly valuable for gene-based analysis, since most GWAS associations to date are non-coding. However, identifying causal genes from regulatory associations remains challenging and contentious. Here, we present a statistical framework and computational tool to integrate heterogeneous annotations with GWAS summary statistics for gene-based analysis, applied with comprehensive coding and tissue-specific regulatory annotations. We compare power and accuracy identifying causal genes across single-annotation, omnibus, and annotation-agnostic gene-based tests in simulation studies and an analysis of 128 traits from the UK Biobank, and find that incorporating heterogeneous annotations in gene-based association analysis increases power and performance identifying causal genes.     

Acetylation changes tau interactome to degrade tau in Alzheimer’s disease animal and organoid models

Alzheimer's disease (AD) is an age‐related neurodegenerative disease. The most common pathological hallmarks are amyloid plaques and neurofibrillary tangles in the brain. In the brains of patients with AD, pathological tau is abnormally accumulated causing neuronal loss, synaptic dysfunction, and cognitive decline. We found a histone deacetylase 6 (HDAC6) inhibitor, CKD‐504, changed the tau interactome dramatically to degrade pathological tau not only in AD animal model (ADLP^APT) brains containing both amyloid plaques and neurofibrillary tangles but also in AD patient‐derived brain organoids. Acetylated tau recruited chaperone proteins such as Hsp40, Hsp70, and Hsp110, and this complex bound to novel tau E3 ligases including UBE2O and RNF14. This complex degraded pathological tau through proteasomal pathway. We also identified the responsible acetylation sites on tau. These dramatic tau‐interactome changes may result in tau degradation, leading to the recovery of synaptic pathology and cognitive decline in the ADLP^APT mice.     

Review: Helicobacter pylori infection in children

Helicobacter pylori infection in children and adolescents differs in comparison to adults with respect to epidemiology, host responses, and disease manifestations. Furthermore, treatment options are limited in this population and antibiotic resistance rates continue to increase. Therefore, ongoing research is vital to understand disease pathogenesis and provide optimal management of children with infection. This review summarizes relevant publications from April 2019 to March 2020. Similar to adults, recent studies show a decreasing prevalence of infection in the pediatric population. Studies of pathogenesis investigated serum immune responses and the potential inverse association of infection and allergy. Several studies investigated the effect of H pylori and related inflammation on the gut microbiome. The recommendation of endoscopy‐based testing to identify the cause of symptoms and not just H pylori, reserving noninvasive UBT or stool antigen tests for post‐eradication follow‐up, was supported by the current literature.