Molecular elastic crystals exhibiting slow magnetic relaxations

We report an elastic crystal of a copper(II) porphyrinato complex that exhibits slow magnetic relaxations and is a promising candidate for an external-force-responsive spin qubit.

Ultra-High-Capacity Lithium Metal Batteries Based on Multi-Electron Redox Reaction of Organopolysulfides including Conductive Organic Moieties

Recently, organic polysulfides have been synthesized as cathode active materials exceeding the battery performance of sulfur. However, the conventional organic polysulfides have exhibited capacities lower than the theoretical capacity of sulfur because the π-organic moieties do not conjugate with the sulfur chains. In this work, the organopolysulfides, synthesized via inverse vulcanization using disulfide compounds, exhibited higher capacities equal to the theoretical capacity of sulfur because of enhanced electronic conductivity based on the conjugation between organic moieties and sulfur chains. Furthermore, the organopolysulfide including 1,3-dhitiol-2-thione moiety exhibited the highest capacity because of the enhanced electronic conductivity. This finding will pave the way to develop next-generation rechargeable batteries.

Potential impact factors on the enhancement of antibiotic resistance in a lake environment

There is considerable concern regarding antibiotic resistance in the water environment due to antibiotic residues from anthropogenic origins. The low antibiotic concentration in the water environment may promote the selection of antibiotic resistance. However, it is unclear how environmental factors affect resistance selection. We investigated the proliferation of quinolone-susceptible faecal bacteria (E. coli) exposed to low norfloxacin concentration (ng/L) at variable temperatures, exposure times, and carbon concentrations, simulating the conditions of the water environment. The induction of antibiotic resistance in thirteen E. coli isolates was more likely to occur at 37 °C. However, resistance also occurred at temperatures as low as 25 °C, provided a longer exposure time of 5 days. These results suggest that antibiotic resistance is more likely to be induced in regions where temperatures may reach 25-37 °C, such as tropical regions.

Solid polymorphism and dynamic magnetic properties of a dodecylated vanadyl–porphyrinato complex: spin–lattice relaxations modulated by phase stabilisation

Phase stabilisation elongates spin–lattice relaxation times.

Ionic Liquid-Containing Coordination Polymer: Solvent-Free Synthesis, Incongruent Melting, and Glass Formation

An ionic-liquid-containing 2D coordination polymer was synthesized via a solvent-free reaction. The material exhibited incongruent melting at 112 °C, forming a solid–liquid mixture; further heating to 240 °C led to...

Relationships between management factors in dairy production systems and mental health of farm managers in Japan

To facilitate sustainable dairy farming, it is essential to assess and support the mental health of dairy farm workers, which is affected more than that of workers in other industries, as indicated by the relatively few studies to date. In addition, the limited investigations on mental health in dairy workers minimize the opportunities to suggest practical approaches of improvement of their mental health. Therefore, further data acquisition and analysis is required. In the present study, we undertook quantitative surveys on 17 management factors and administered a mental health questionnaire to 81 dairy farm managers (80 male, 1 female) in Hokkaido, northern Japan. The management factors were categorized into 3 groups: production input, production output, and facility indicator; mental health was evaluated based on the Center for Epidemiologic Studies Depression Scale (CES-D). Principal component analysis assigned the factors into 2 groups: intensiveness factors of dairy production systems (PC1: livestock care cost, fat- and protein-corrected milk, stocking density, medical consultation fee per unit time per animal unit, nonfamily wages, fertilizer and pesticide expenses, and net agricultural income ratio) and basic dairy management factors (PC2: net agricultural income ratio, quantity of concentrate feed, and milk quality variable). The depression symptoms of dairy farm managers were not significantly associated with PC1 and milking methods; however, they were significantly negatively associated with PC2, which integrated 3 management factors, including factors related to finances, feeding, and milk quality. According to the findings of the present study, the efforts needed for stable economic farm management, adequate feed supply, and milk quality maintenance may increase the depression levels of dairy farm managers and negatively affect their mental health. These findings could be the basis for future studies on the relationship between the mental health of farm managers and sustainable dairy farm management and production.

The involvement of axillary reverse mapping nodes in patients with clinically node-negative breast cancer

BACKGROUND

Axillary reverse mapping (ARM) was developed to preserve the lymphatic drainage from the upper arm during sentinel lymph-node (SLN) biopsy or axillary lymph-node dissection (ALND). However, the oncological safety of ARM has been controversial because of not infrequent involvement of ARM nodes.

METHODS

Patients with clinically negative nodes (cN0) underwent SLN biopsy and ARM. SLNs were identified using blue dye and radioisotope, and ARM nodes were traced using the fluorescent method. Patients with positive SLN underwent the standard ALND. After surgery, they were followed up for more than 3 years.

RESULTS

A total of 507 patients with cN0 breast cancer were enrolled between May 2009 and November 2017. SLNs were identified in 499 (98%) of 507 patients, and ARM nodes were identified in 159 (31%) patients in the SLN field. The crossover rate of SLN-ARM nodes was 28%. Among 95 patients with positive SLNs, 70 patients underwent conventional ALND. ARM nodes were identified in 65 (93%) of those patients in the ALND field. The mean number of removed ARM nodes was 7.2 (range 0-25) in patients who underwent the standard ALND. Although ARM nodes were involved in 18 of 65 patients, the involved ARM nodes were the same SLNs identified in 14 (78%) patients. Since SLN-ARM nodes should be removed, ARM nodes were involved only in 4 (5.7%) patients after SLN biopsy.

CONCLUSIONS

Except for positive SLN-ARM nodes, the involvement of ARM nodes is infrequent in patients with positive SLN.

Vermiculite as a culture substrate greatly improves the viability of frozen cultures of ectomycorrhizal basidiomycetes

We assessed a new cryopreservation protocol that uses vermiculite as a culture substrate, called the vermiculite protocol (VP), by assessing the viability, recovery time of hyphae after revival, and colony diameter of cryosensitive ectomycorrhizal basidiomycete strains after storage for 2 weeks or 1 year in a vapour-phase liquid nitrogen tank. Twelve difficult-to-preserve strains of nine species (Amanita citrina, A. pantherina, A. rubescens, A. spissa, Kobayasia nipponica, Lactarius akahatsu, L. hatsudake, Sarcodon aspratus, and Tricholoma flavovirens) that did not achieve good revival after cryopreservation with our previous Homolka's perlite protocol and modified perlite protocol (MPP) experiments were used to assess the new methodology. Vermiculite and liquid medium were put into a cryotube and inoculated with an agar plug containing mycelia. The cryotube was cultured for various incubation times. After adequate mycelial growth, a mixture of cryoprotectants (5% dimethyl sulfoxide and 10% trehalose [5D10T] or 5% glycerol and 10% trehalose [5G10T]) was placed into the cryotube. The cryotube was frozen in a freezing container in a -80 °C freezer and then stored in vapour-phase liquid nitrogen. In the recovery test, 10 of 12 strains showed 100% revival after 2 weeks of storage in the 5G10T cryoprotectant, and all 12 strains showed 100% revival after 2 weeks of storage in the 5D10T cryoprotectant. Furthermore, all strains were viable after 1 year of storage in a vapour-phase liquid nitrogen tank. Thus, the VP is applicable to a wide range of ectomycorrhizal basidiomycete cultures, including highly cryosensitive strains.

Solid-State Spin Equilibrium of Ni(cyclam)2 Complex: Magnetostructural Correlations in Two Polymorphs

Two crystal polymorphs of Ni(cyclam)I₂ (cyclam = 1,4,8,11-tetraazacyclotetradecane) were synthesized, and their magnetic properties were investigated. Temperature-dependent X-ray structural analysis and magnetic measurements revealed gradual spin transition in molecular-crystal polymorph trans-[Ni(cyclam)I₂] (1a), whereas the zigzag-chain polymorph catena-[Ni(cyclam)(μ-I)]I (1b) did not show an obvious spin transition. The entropy difference between high- and low-spin states of 1a estimated by assuming the spin-equilibrium model is much smaller than those in typical iron(II)-based spin-crossover (SCO) complexes, suggesting that the normal mode softening is less remarkable in 1a. In this system, it is clearly evidenced that the interaction mode responsible to the spin equilibrium in octahedral nickel(II) complexes is highly anistropic, i.e., z-elongation and x,y-shortening of the coordination octahedron.

Temperature dependence of spherical electron transfer in a nanosized [Fe14] complex

The study of transition metal clusters exhibiting fast electron hopping or delocalization remains challenging, because intermetallic communications mediated through bridging ligands are normally weak. Herein, we report the synthesis of a nanosized complex, [Fe(Tp)(CN)3]8[Fe(H2O)(DMSO)]6 (abbreviated as [Fe14], Tp-, hydrotris(pyrazolyl)borate; DMSO, dimethyl sulfoxide), which has a fluctuating valence due to two mobile d-electrons in its atomic layer shell. The rate of electron transfer of [Fe14] complex demonstrates the Arrhenius-type temperature dependence in the nanosized spheric surface, wherein high-spin centers are ferromagnetically coupled, producing an S = 14 ground state. The electron-hopping rate at room temperature is faster than the time scale of Mössbauer measurements (<~10-8 s). Partial reduction of N-terminal high spin FeIII sites and electron mediation ability of CN ligands lead to the observation of both an extensive electron transfer and magnetic coupling properties in a precisely atomic layered shell structure of a nanosized [Fe14] complex.

A modified perlite protocol with a mixed dimethyl sulfoxide and trehalose cryoprotectant improves the viability of frozen cultures of ectomycorrhizal basidiomycetes

Homolka's perlite protocol (HPP) was evaluated for cryopreservation of a wide range of ectomycorrhizal basidiomycete cultures, then a modified perlite protocol (MPP), in which cryoprotectant was added just before freezing rather than during the culturing process, was applied to cryosensitive strains that failed to survive when HPP was used. Further modifications of MPP with various cryoprotectants were explored to improve the cryopreservation of hard-to-preserve strains. The efficacy of HPP was assessed in 111 strains of 38 species of basidiomycetes of various cryosensitivities. After freezing strains using HPP, the viability and colony diameter of the strains were examined after 2 wk, 6 mo, and 1 y of storage at -80 C. Of the 111 strains tested, 91 survived after 1 y of storage with high viability of 80% or more, whereas the remaining 20 strains exhibited low and unstable viability. For those selected cryosensitive strains that did not survive well when HPP was used, MPP was applied with a mixture of cryoprotectants, dimethyl sulfoxide (DMSO), glycerol, and trehalose, at different concentrations and combinations. Toxicity testing of the cryoprotectants in the nonfrozen state revealed that 12% (v/v) glycerol was highly toxic for six strains (four species), whereas DMSO (5% and 10% [v/v]) was less toxic than glycerol. The viability of the cryosensitive strains after freezing demonstrated that DMSO was more efficient than glycerol, and trehalose enhanced the cryoprotective effects of both glycerol and DMSO when MPP was used for cryopreservation. Our comparative analysis of MPP with various combinations and concentrations of cryoprotectants revealed that a mixture of 5% DMSO and 10% trehalose was the most effective cryoprotectant, and that using MPP with this cryoprotectant was applicable to many cryosensitive strains.