基底高スピンとなる3dホモ金属および3d-4fヘテロ金属錯体の構造と磁性の研究

This doctor thesis is written about the structural and magnetic study on the complexes related to single-molecule magnets (SMMs). SMMs have been attractive molecules due to their potential applications for information storage and quantum computing at the molecular level. Large magnetic moment and strong uniaxial magnetic anisotropy are required for SMMs. The author succeeded to prepare some novel compounds and precisely determined the magnetic parameters by means of magnetizations, magnetic susceptibilities, and electron paramagnetic resonance (EPR) techniques.The author studied the structure and magnetic properties of a novel nickel(II) trinuclear complex as well as two known related compounds. They possess the ground high-spin state and a uniaxial magnetic anisotropy, which are favorable for SMMs. However, they also showed intermolecular antiferromagnetic couplings through the weak halogen...halogen contacts. One of these complexes was characterized as a pseudo one-dimensional antiferromagnetic chain, and another as a ground antiferromagnet. The magnetic hysteresis was observed at the metamagnetic-like magnetization jump and not at zero field. The author concluded that the compounds were potential SMMs with considerable intermolecular antiferromagnetic interaction.For a heterospin 4f-3d system, the author et al. synthesized three new complexes involving one dysprosium(III) and two copper(II) ion as a magnetically interacting unit. The structural analysis of them clarified double oxygen bridges between the Dy and Cu ions. The magnetic study revealed the presence of Dy?Cu ferromagnetic interactions together with the SMM behavior.From the high-frequency EPR study the author found that the copper signal was biased owing to the exchange interaction from the dysprosium ion. The exchange coupling parameters were precisely determined from these exchange biases. To investigate magneto-structure relation, two additional data were taken from the literature, and the author attempted to draw a few plots of the exchange parameter as a function of geometrical parameters. Meaningful correlations were found when the Dy?O?Cu angle and Dy?O???O?Cu dihedral angle were applied. Though it is only empirical, such a magneto-structure relation has been proposed in Dy?Cu systems for the first time.In conclusion, the magnetic properties of the Ni3 and DyCu2 complexes were studied in detail in connection with the crystal structures. The present results would assist comprehension of SMMs and accelerate development of novel SMMs.電気通信大学201

Rising rural body-mass index is the main driver of the global obesity epidemic in adults

Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

The Contribution of SAA1 Polymorphisms to Familial Mediterranean Fever Susceptibility in the Japanese Population

Background/Aims: Familial Mediterranean Fever (FMF) has traditionally been considered to be an autosomal-recessive disease, however, it has been observed that substantial numbers of patients with FMF possess only 1 demonstrable MEFV mutation. The clinical profile of familial Mediterranean fever (FMF) may be influenced by MEFV allelic heterogeneity and other genetic and/or environmental factors. Methodology/Principal Findings: In view of the inflammatory nature of FMF, we investigated whether serum amyloid A (SAA) and interleukin-1 beta (IL-1β) gene polymorphisms may affect the susceptibility of Japanese patients with FMF. The genotypes of the -13C/T SNP in the 5′-flanking region of the SAA1 gene and the two SNPs within exon 3 of SAA1 (2995C/T and 3010C/T polymorphisms) were determined in 83 Japanese patients with FMF and 200 healthy controls. The same samples were genotyped for IL-1β-511 (C/T) and IL-1 receptor antagonist (IL-1Ra) variable number of tandem repeat (VNTR) polymorphisms. There were no significant differences between FMF patients and healthy subjects in the genotypic distribution of IL-1β -511 (C/T), IL-1Ra VNTR and SAA2 polymorphisms. The frequencies of SAA1.1 allele were significantly lower (21.7% versus 34.0%), and inversely the frequencies of SAA1.3 allele were higher (48.8% versus 37.5%) in FMF patients compared with healthy subjects. The frequency of -13T alleles, associated with the SAA1.3 allele in the Japanese population, was significantly higher (56.0% versus 41.0%, p = 0.001) in FMF patients compared with healthy subjects. Conclusions/Significance: Our data indicate that SAA1 gene polymorphisms, consisting of -13T/C SNP in the 5′-flanking region and SNPs within exon 3 (2995C/T and 3010C/T polymorphisms) of SAA1 gene, are associated with susceptibility to FMF in the Japanese population

Linker Stoichiometry-controlled stepwise supramolecular growth of a flexible Cu₂Tb single molecule magnet from monomer to dimer to one-dimensional chain

A trinuclear complex [(CuL)₂Tb(H₂O)(NO₃)₃]•MeOH•H₂O (1) is synthesized by using a metalloligand [CuL] (H₂L = N,N′-bis(salicylidene)-1,3-propanediamine or salpn). This complex is used as a new 3d-4f metallatecton for stepwise supramolecular oligomerization along with a simple diimine linker, 4,4′-bipyridine (bpy). A ratio of metallatecton/linker = 2:1 is conducive for the formation of a dimer [{(CuL) ₂Tb(H₂O)(NO₃)₃}₂bpy]•2MeOH•4H₂O (2), whereas a higher proportion of linker at a ratio of 1:1 gives rise to a zigzag one-dimensional coordination polymer {[(CuL) ₂Tb(NO₃)₃bpy]•MeOH•2H₂O}_∞ (3). The inherent conformational flexibility of the trinuclear (CuL) ₂Tb node which is folded (cisoid) for 1 and 2 (asymmetric TbO₉ tricapped trigonal prism) and unfolded (transoid) for 3 (a C₂-symmetric TbO₁₀ tetradecahedron) seems to stabilize the crystal packing of these coordination-driven self-assemblies. The rapidly saturated magnetization at 1.8 K for 1 (11 μ_B) and 2 (22 μ_B) clearly indicates the presence of Tb–Cu ferromagnetic coupling through the phenoxido bridges of the Cu(μ_1,1-O) ₂Tb(μ_1,1-O)₂Cu cores. A slow saturation behavior has been found for 3 (9.5 μ_B). Both in-phase and out-of-phase ac magnetic measurements of 1 under an applied dc magnetic field reveal temperature dependence of the susceptibility at different frequencies below 5 K, characteristic of Single Molecule Magnets (SMMs), which is conserved in 2 and 3 signifying oligo- and polymeric aggregates of SMMs

Formation of two drastically different MOFs based on Mn(II)–benzoate and pyrazine with a change in seasonal temperature: structural analysis and magnetic study

Two new stoichiometrically and structurally very different Mn (II) coordination compounds {[Mn(pyz)(C6H5COO)2](C2H5OH)}n (1) and [Mn5(pyz)(C6H5COO)10(H2O)2]n (2) (where pyz = pyrazine) have been synthesized by the reaction of Mn(C6H5COO)2•4H2O and pyz in 1 : 1 molar ratio in different seasons of the year. The structural analyses reveal that complex 1, which is synthesized in summer when the temperature remains around 28–40 °C, features a 1D molecular ladder formed by joining of syn–syn benzoate-bridged dimeric Mn (II) units by pyz. Complex 2, which is obtained in winter (temperature around 10–20 °C), is an unprecedented 2D rectangular sheet motif based on a 1D column constructed from syn–syn benzoate bridged repetitive Mn5 units which are further interconnected by the pyz spacer. The compounds are interconvertible in solution: when an ethanol solution of 1 is allowed to evaporate slowly in winter or in a refrigerator (5–6 °C) it transformed into 2 whereas crystallization of 2 from ethanol medium in summer (28–40 °C) yields 1. Variable-temperature (1.8–300 K) magnetic susceptibility measurements showed presence of weak antiferromagnetic coupling in 1 that has been fitted with the van Vleck equation. The interaction in benzoate-bridged Mn2 unit was characterized to be J = −0.586(1) cm−1, where the spin-Hamiltonian is defined as H = −2JS1S2. The interaction in 2 was also characterized with the modified van Vleck equation to be weakly antiferromagnetic

Amino Acid Substitutions in Mosaic Penicillin-Binding Protein 2 Associated with Reduced Susceptibility to Cefixime in Clinical Isolates of Neisseria gonorrhoeae

The molecular mechanisms of reduced susceptibility to cefixime in clinical isolates of Neisseria gonorrhoeae, particularly amino acid substitutions in mosaic penicillin-binding protein 2 (PBP2), were examined. The complete sequence of ponA, penA, and por genes, encoding, respectively, PBP1, PBP2, and porin, were determined for 58 strains isolated in 2002 from Japan. Replacement of leucine 421 by proline in PBP1 and the mosaic-like structure of PBP2 were detected in 48 strains (82.8%) and 28 strains (48.3%), respectively. The presence of mosaic PBP2 was the main cause of the elevated cefixime MIC (4- to 64-fold). In order to identify the mutations responsible for the reduced susceptibility to cefixime in isolates with mosaic PBP2, penA genes with various mutations were transferred to a susceptible strain by genetic transformation. The susceptibility of partial recombinants and site-directed mutants revealed that the replacement of glycine 545 by serine (G545S) was the primary mutation, which led to a two- to fourfold increase in resistance to cephems. Replacement of isoleucine 312 by methionine (I312M) and valine 316 by threonine (V316T), in the presence of the G545S mutation, reduced susceptibility to cefixime, ceftibuten, and cefpodoxime by an additional fourfold. Therefore, three mutations (G545S, I312M, and V316T) in mosaic PBP2 were identified as the amino acid substitutions responsible for reduced susceptibility to cefixime in N. gonorrhoeae

A unique example of structural diversity tuned by apparently innocento-,m-, and p-nitro substituents of benzoate in their complexes of Mn (II) with 4,4′-bipyridine: 1D ladder, 2D sheet, and 3D framework

Four new Mn(II) coordination polymers [Mn(4,4′-bpy)(C₆H₅COO)₂]_n (1), [Mn(4,4′-bpy)(o-(NO)₂)C)₆H4COO) )₂]_n (2), [Mn(4,4′-bpy)(m-(NO)₂)C)₆H)₄COO) )₂]_n (3) and [Mn(4,4′-bpy)(p-(NO)₂)C)₆H)₄COO) )₂]_n (4) (where 4,4′-bpy = 4,4′-bipyridine) have been synthesized by self-assembly of the primary ligands, benzoate and the o-, m- and p-isomers of nitrobenzoates, respectively, together with 4,4′-bpy as the secondary spacer. All four complexes were characterized by elemental analyses, IR spectroscopy, single-crystal X-ray diffraction analyses and variable-temperature magnetic measurements. The structural analyses reveal that complexes 1 and 3 are constructed by linear fused chains through double syn-syn (for 1) or syn-anti (for 3) carboxylate-bridged Mn (II), which are further linked to one another by trans coordinated 4,4′-bpy bridges, giving rise to a rectangular grid-like two-dimensional (2D) net. Complex 2 features one-dimensional (1D) molecular ladder formed by both syn-syn and syn-anti carboxylate-bridged dimeric Mn (II) units which are joined alternately by 4,4′-bpy. Complex 4 is formed by fused zigzag chains of double syn-syn carboxylate-bridged Mn (II) that are connected by cis oriented 4,4′-bpy to generate an unprecedented three-dimensional (3D) framework. The dimensionality of the complexes thus varies from 1D to 2D to 3D on changing the position of the nitro group from o- to m- to p- in the benzoate, showing explicitly the tuning ability of this apparently innocent substituent on the topology of the coordination polymer. Variable-temperature (1.8–300 K) magnetic susceptibility measurements showed the presence of antiferromagnetic coupling in all four complexes that have been fitted with an infinite classical-spin chain model derived by Fisher for 1, 3, and 4 (J = −0.779(2), −0.855(2) and −0.536(2) cm^–1, respectively) and van Vleck equation for 2 (J = −0.354(2) cm^–1)