Photoinduced Magnetization with a High Curie Temperature and a Large Coercive Field in a Co‐W Bimetallic Assembly

The crystal structure, magnetic properties, and temperature‐ and photoinduced phase transition of [{Co^II(4‐methylpyridine)(pyrimidine)}₂{Co^II(H₂O)₂}{W^V(CN)₈}₂]·4H₂O are described. In this compound, a temperature‐induced phase transition from the Co^II (S = 3/2)‐NC‐W^V(S = 1/2) [high‐temperature (HT)] phase to the Co^III(S = 0)‐NC‐W^IV(S = 0) [low temperature (LT)] phase is observed due to a charge‐transfer‐induced spin transition. When the LT phase is irradiated with 785 nm light, ferromagnetism with a high Curie temperature (T_C) of 48 K and a gigantic magnetic coercive field (H_c) of 27 000 Oe are observed. These T_C and H_c values are the highest in photoinduced magnetization systems. The LT phase is optically converted to the photoinduced phase, which has a similar valence state as the HT phase due to the optically induced charge‐transfer‐induced spin transition.     

Dietary supplementation of gamma-linolenic acid improves skin parameters in subjects with dry skin and mild atopic dermatitis

Disruption of the skin barrier function caused by epidermal hyper-proliferation, results in the skin becoming dry and showing high transepidermal water loss (TEWL). Gamma linolenic acid (GLA) is reportedly efficacious for treating TEWL and epidermal hyper-proliferation. In this study, to elucidate the effect of GLA-rich oil on skin function, GLA-containing food was given to adults with dry skin or mild atopic dermatitis and skin parameters were evaluated. In the results, we recognized beneficial effects on the TEWL index. The efficacy of GLA was also demonstrated to be statistically significant especially in subjects with pro-inflammatory features. The results suggest that the mechanism of improvement of skin barrier has been associated with possible generation of anti-inflammatory metabolites from GLA. The clinical physician also confirmed that none of the subjects showed any noteworthy side effects. GLA-enriched food appears to be safe and to improve skin barrier function in subjects with dry skin conditions and mild atopic dermatitis.     

Label-Free Investigations on the G Protein Dependent Signaling Pathways of Histamine Receptors

G protein activation represents an early key event in the complex GPCR signal transduction process and is usually studied by label-dependent methods targeting specific molecular events. However, the constrained environment of such “invasive” techniques could interfere with biological processes. Although histamine receptors (HRs) represent (evolving) drug targets, their signal transduction is not fully understood. To address this issue, we established a non-invasive dynamic mass redistribution (DMR) assay for the human H_1–4Rs expressed in HEK cells, showing excellent signal-to-background ratios above 100 for histamine (HIS) and higher than 24 for inverse agonists with pEC₅₀ values consistent with literature. Taking advantage of the integrative nature of the DMR assay, the involvement of endogenous Gα_q/11, Gα_s, Gα_12/13 and Gβγ proteins was explored, pursuing a two-pronged approach, namely that of classical pharmacology (G protein modulators) and that of molecular biology (Gα knock-out HEK cells). We showed that signal transduction of hH_1–4Rs occurred mainly, but not exclusively, via their canonical Gα proteins. For example, in addition to Gα_i/o, the Gα_q/11 protein was proven to contribute to the DMR response of hH_3,4Rs. Moreover, the Gα_12/13 was identified to be involved in the hH₂R mediated signaling pathway. These results are considered as a basis for future investigations on the (patho)physiological role and the pharmacological potential of H_1–4Rs.     

Photophysical properties and photostability of novel symmetric polycyclicphenazine-type fluorescent dyes and the dye-doped films

Novel symmetric polycyclicphenazine-type fluorescent dyes have been synthesized and characterized in solution and in polymer films. The dyes exhibited two strong absorption bands at around 365-428 nm and 519-567 nm and an intense fluorescence band at around 560-600 nm (Ф = 0.70-0.87) in 1,4-dioxane. The dye-doped polymer films showed excellent wavelength conversion function that efficiently convert ultraviolet and yellow lights into red light (Ф = 0.61-0.92). Moreover, the photostability of the dye-doped PS, PMMA, and PLA films has been investigated.     

Facile synthesis of branched chitin by glycosylation of fully trimethylsilylated chitin with a glucosamine-derived oxazoline

A simple and straightforward procedure for synthesizing branched chitin and chitosan has been developed on the basis of the glycosylation of trimethylsilylated chitin with an oxazoline derived from d-glucosamine. Chitin was first trimethylsilylated, and the derivative was treated with the oxazoline to introduce peracetylated d-glucosamine branches into the chitin backbone. The extent of branching was dependent on the amount of the oxazoline and reaction time, and under appropriate conditions, it reached around 0.65. Selective O-deacetylation or thorough N,O-deacetylation of the resulting glycosylated product gave chitin having N-acetyl-d-glucosamine branches or chitosan having d-glucosamine branches.     

Effect of Long Chain Fatty Acids on Organocatalytic Aqueous Direct Aldol Reactions

In an organocatalyzed, aqueous direct aldol reaction, the addition of a long chain fatty acid (1 mol%) such as stearic acid or erucic acid improved the aldol product yield and the enantioselectivity with low catalyst loading (1 mol%). The small particle size of the emulsion (less than 1 μm) was a key to the enhanced reactivity as shown by dynamic light scattering (DLS) analyses.     

Improvement of high temperature stability of Pd coating on Ta by HfN intermediate layer

Hafnium nitride (HfN) was chosen as a material for non-porous intermediate layer to improve the high temperature stability of Pd–Ta composite membranes for hydrogen separation. A layer of dense HfN (70 nm) was prepared between Ta substrate and thin Pd film (300 nm), and the high temperature stability of Pd coating was examined by hydrogen absorption experiments at 573 K after the heat treatments at 873 and 973 K. The HfN layer showed obvious hydrogen permeability, though the permeation rate in HfN appeared to be smaller than that in Pd and Ta. In addition, the degradation in coating effects of Pd at elevated temperatures was substantially retarded by HfN layer. Such improved stability was ascribed to retardation of open porosity development in Pd films and interdiffusion between Pd and Ta. It was concluded that HfN is a potential candidate material for intermediate layer to improve high temperature stability of Pd-group 5 metal composite hydrogen separation membranes.     

Atom-resolved noncontact atomic force microscopic and scanning tunneling microscopic observations of the structure and dynamic behavior of CeO2(1 1 1) surfaces

Atomic-scale structures and dynamic behaviors of CeO₂(1 1 1) surfaces were imaged by noncontact atomic force microscopy (NC-AFM) and scanning tunneling microscopy (STM). Hexagonally arranged oxygen atoms, oxygen point vacancies, multiple oxygen vacancies, and hydrogen adatoms at the surfaces were visualized by atom-resolved NC-AFM observations. Multiple defects were stabilized by displacement of the surrounding oxygen atoms around the multiple defects, which gave enhanced brightness in the NC-AFM image due to a geometric reason. Multiple defects without reconstruction of the surrounding oxygen atoms were reactive and were healed by exposure to O₂ gas and methanol at RT. Successive NC-AFM and STM measurements of slightly reduced CeO₂(1 1 1) surfaces revealed that hopping of surface oxygen atoms faced to the metastable multiple defects was thermally activated even at room temperature (RT) and more promoted at higher temperatures. Heterogeneous feature of the reactivity of surface oxygen atoms with methanol was imaged by successive NC-AFM observations. These observations gave a new insight for understanding the surface structures and behavior of CeO_2−x with the facile oxygen reservoir and oxidation–reduction properties related to the unique catalysis.