Microparticles with hetero-nanointerfaces: controlled assembly of cobalt hydroxide and nickel hydroxide nanoclusters towards improved electrochemical functions

The ultimate control of the interfaces of nanocomposite materials is essential to tailor and improve their physical/chemical properties in applications such as catalysis, or energy storage or production. Fabrication and co-assembly of a variety of nanostructured colloids is a promising way to design the interface of materials in nano-scale toward high functionality. In this study, we demonstrate a synthesis of colloids of nanocluster-sized (~ 2 nm) cobalt and nickel hydroxides and their assembly into microparticles that present hetero-nanointerfaces. Electrochemical properties were investigated to elucidate the effect of the hetero-nanointerface. Microparticles with hetero nanostructures composed of cobalt and nickel hydroxide nanoclusters revealed improved mass specific capacity (91.4 mAh/g) compared with respective microparticles with homo-nanointerface (cobalt hydroxide; 15.8 mAh/g: nickel hydroxide; 64.4 mAh/g). Further investigation suggests that the introduced hetero-nanointerface leads to lower charge transfer resistance and to improved electrochemical properties. The synthetic concept demonstrated here is expected to create unique hetero-nanointerfaces for various materials with wide-range of chemical composition towards improved and novel functionalities.The present work is partially supported by JSPS KAKENHI, LNLS proposal SAXS1 18927, ANPCyT (PICT 2087), UBACyT (20020130100610BA), Izumi Science and Technology Foundation (H29-J-130) and the Foundation for the Promotion of Ion Engineering

Mesoporous Microspheres of Nickel-based Layered Hydroxides by Aerosol-Assisted Self-Assembly using Crystalline Nano-Building Blocks.

Structural control in micro- and nanometer scale is necessary to design highly functional materials. Crystalline mesoporous microspheres are expected to improve electrochemical, catalytic, and adsorption performances. In this study, we focused on the preparation of templated mesoporous microspheres of nickel-based layered hydroxides by using pre-crystallized nano-building blocks (NBBs). Layered nickel hydroxide nanoparticles were prepared through an epoxide-mediated alkalinization process and used as NBBs to construct microspheres. The spherical particles in micrometer scale were synthesized by an aerosol-assisted assembly of the NBBs dispersed in a solvent, in the presence of supramolecular templates. It was found that controlling the crystallization as well as the surface philicity permits to yield the NBB with an adequately small size and interparticle interactions that generate self-assembled mesoporous microspheres akin to those obtained in NBB-based mesoporous thin films. The preparation technique demonstrated here is highly versatile; templated mesoporous microspheres with various chemical compositions of nickel-based layered double hydroxides were successfully obtained.The present work was partially supported by JSPS KAKENHI, JSPS bilateral program, LNLS proposal SAXS1 18927, ANPCyT (PICT 2012-2087 and 2015-3526), UBACyT (20020130100610BA), Hitachi Metals Materials Science Foundation, The Sumitomo Foundation, and Izumi Science and Technology Foundation

Single-nanometer sized low-valence metal hydroxide crystals: synthesis via epoxide-mediated alkalinization and assembly towards functional mesoporous materials

The present work is partially supported by JSPS KAKENHI, LNLS proposal SAXS1 18927, ANPCyT (PICT 2087), UBACyT (20020130100610BA), and the Foundation for the Promotion of Ion Engineering

Highly Ordered Mesoporous Hydroxide Thin Films through Self-Assembly of Size-Tailored Nano-Building Blocks: A Theoretical- Experimental Approach

Mesoporous crystalline (hydr)oxides of low-valence metal ions (M(II) and M(III)) are highly demanded in the context of various applications. In this study, we demonstrate key factors to the successful formation of ordered mesoporous films through the Assembly of Nano-Building Block (ANBB) approach using a colloidal solution of crystalline M(OH)2 (M = Mn, Fe, Co, Ni, and Cu). The colloidal system of α-Ni(OH)2 is presented in-depth as a typical example. Crystal growth and aggregation kinetics of the NBB were tuned by synthetic parameters. Nanometer-sized NBBs of tailored size between oligomer scale to over 20 nm were obtained. The films prepared from α-Ni(OH)2 NBBs with a diameter of ≤ 7.5 nm showed ordered mesostructures through evaporation-induced self-assembly in the presence of supramolecular templates. Coarse-grained simulation suggests that there is a threshold diameter of NBB toward the formation of wellordered mesostructures. It was found that, as well as limiting the diameter of NBB, inhibition of an aggregation of NBBs by using coordinative additives or diluting the NBB colloidal solution were essential to control the assembly of NBBs and templates into the ordered mesostructures. The results obtained here open up the synthesis of ordered mesoporous materials with a crystalline wall of variety of chemical compositions containing low-valence metal elements.The present work was partially supported by JSPS KAKENHI, JSPS bilateral program, ABTLuS (LNLS proposal SAXS1 18927), ANPCyT (PICT 2014-3687 and 2015-3526), UBACyT (20020130100610BA), The Sumitomo Foundation, Izumi Science and Technology Foundation and Deutsche Forschungsgemeinschaft-CONICET under grant Mu1674/15-1

Biochemical classification of tauopathies by immunoblot, protein sequence and mass spectrometric analyses of sarkosyl-insoluble and trypsin-resistant tau

Intracellular filamentous tau pathology is the defining feature of tauopathies, which form a subset of neurodegenerative diseases. We have analyzed pathological tau in Alzheimer’s disease, and in frontotemporal lobar degeneration associated with tauopathy to include cases with Pick bodies, corticobasal degeneration, progressive supranuclear palsy, and ones due to intronic mutations in MAPT. We found that the C-terminal band pattern of the pathological tau species is distinct for each disease. Immunoblot analysis of trypsin-resistant tau indicated that the different band patterns of the 7–18 kDa fragments in these diseases likely reflect different conformations of tau molecular species. Protein sequence and mass spectrometric analyses revealed the carboxyl-terminal region (residues 243–406) of tau comprises the protease-resistant core units of the tau aggregates, and the sequence lengths and precise regions involved are different among the diseases. These unique assembled tau cores may be used to classify and diagnose disease strains. Based on these results, we propose a new clinicopathological classification of tauopathies based on the biochemical properties of tau

Structure-based classification of tauopathies

The ordered assembly of tau protein into filaments characterizes several neurodegenerative diseases, which are called tauopathies. It was previously reported that, by cryo-electron microscopy, the structures of tau filaments from Alzheimer’s disease, Pick’s disease, chronic traumatic encephalopathy and corticobasal degeneration are distinct. Here we show that the structures of tau filaments from progressive supranuclear palsy (PSP) define a new three-layered fold. Moreover, the structures of tau filaments from globular glial tauopathy are similar to those from PSP. The tau filament fold of argyrophilic grain disease (AGD) differs, instead resembling the four-layered fold of corticobasal degeneration. The AGD fold is also observed in ageing-related tau astrogliopathy. Tau protofilament structures from inherited cases of mutations at positions +3 or +16 in intron 10 of MAPT (the microtubule-associated protein tau gene) are also identical to those from AGD, suggesting that relative overproduction of four-repeat tau can give rise to the AGD fold. Finally, the structures of tau filaments from cases of familial British dementia and familial Danish dementia are the same as those from cases of Alzheimer’s disease and primary age-related tauopathy. These findings suggest a hierarchical classification of tauopathies on the basis of their filament folds, which complements clinical diagnosis and neuropathology and also allows the identification of new entities—as we show for a case diagnosed as PSP, but with filament structures that are intermediate between those of globular glial tauopathy and PSP

Kinetics of circulating Th17 cytokines and adipokines in psoriasis patients

Psoriasis is associated with an increase of Th17 cytokines, such as IL-17, IL-22, IL-21, and TNF-α, which are produced by Th17 cells. Adipokines are peptide hormones or cytokines secreted from adipose tissues and involved in the pathogenesis of metabolic syndrome (MS). Psoriasis patients have a high prevalence of the MS. In this study, we investigated the statistics of circulating Th17-related cytokines and adipokines in psoriasis patients. Our study identified the significant elevation of serum IL-6, IL-21, IL-22, and resistin levels in psoriasis patients. Increased serum levels of IL-22 and adiponectin were positively correlated with Psoriasis Area and Severity Index (PASI). In contrast, serum high molecular weight adiponectin levels were decreased in psoriasis and negatively correlated with PASI

Requirement of CHROMOMETHYLASE3 for somatic inheritance of the spontaneous tomato epimutation Colourless non-ripening

Naturally-occurring epimutants are rare and have mainly been described in plants. However how these mutants maintain their epigenetic marks and how they are inherited remain unknown. Here we report that CHROMOMETHYLASE3 (SlCMT3) and other methyltransferases are required for maintenance of a spontaneous epimutation and its cognate Colourless non-ripening (Cnr) phenotype in tomato. We screened a series of DNA methylation-related genes that could rescue the hypermethylated Cnr mutant. Silencing of the developmentally-regulated SlCMT3 gene results in increased expression of LeSPL-CNR, the gene encodes the SBP-box transcription factor residing at the Cnr locus and triggers Cnr fruits to ripen normally. Expression of other key ripening-genes was also up-regulated. Targeted and whole-genome bisulfite sequencing showed that the induced ripening of Cnr fruits is associated with reduction of methylation at CHG sites in a 286-bp region of the LeSPL-CNR promoter, and a decrease of DNA methylation in differentially-methylated regions associated with the LeMADS-RIN binding sites. Our results indicate that there is likely a concerted effect of different ethyltransferases at the Cnr locus and the plant-specific SlCMT3 is essential for sustaining Cnr epi-allele. Maintenance of DNA methylation dynamics is critical for the somatic stability of Cnr epimutation and for the inheritance of tomato non-ripening phenotype

Erk1/2 MAP kinases are required for epidermal G2/M progression

Erk1/2 mitogen-activated protein kinases (MAPKs) are often hyperactivated in human cancers, where they affect multiple processes, including proliferation. However, the effects of Erk1/2 loss in normal epithelial tissue, the setting of most extracellular signal-regulated kinase (Erk)–associated neoplasms, are unknown. In epidermis, loss of Erk1 or Erk2 individually has no effect, whereas simultaneous Erk1/2 depletion inhibits cell division, demonstrating that these MAPKs are necessary for normal tissue self-renewal. Growth inhibition caused by Erk1/2 loss is rescued by reintroducing Erk2, but not by activating Erk effectors that promote G1 cell cycle progression. Unlike fibroblasts, in which Erk1/2 loss decreases cyclin D1 expression and induces G1/S arrest, Erk1/2 loss in epithelial cells reduces cyclin B1 and c-Fos expression and induces G2/M arrest while disrupting a gene regulatory network centered on cyclin B1–Cdc2. Thus, the cell cycle stages at which Erk1/2 activity is required vary by cell type, with Erk1/2 functioning in epithelial cells to enable progression through G2/M