Developmental capacity and implantation potential of the embryos with multinucleated blastomeres.

The presence of multinucleated blastomeres (MNBs) in embryos is associated with poor developmental competence in assisted reproductive technologies. This phenomenon is observed not only in humans but also in other animal species. The purpose of the present study was to investigate the characteristics of embryos with MNBs (MNB embryos) that could be utilized in embryo transfer. The developmental rate of MNB embryos to the blastocyst stage (50.8%) was significantly lower than that of normal embryos (73.3%) (P < 0.05). The clinical pregnancy rates of fresh embryo transfer (ET) using day 2 or day 3 embryos were significantly lower in MNB embryos (5.1%) compared with normal embryos (24.0%) (P < 0.05). In the case of frozen-thawed ET using a single vitrified/warmed blastocyst, however, the clinical pregnancy rate of MNB embryos was close to that of normal embryos (59.1% vs. 52.8%). Thus, the findings of the present study suggest that the frozen-thawed ET of MNB embryos might improve the potential for implantation followed by successful pregnancy.

Role of edge geometry and chemistry in the electronic properties of graphene nanostructures.

The geometry and chemistry of graphene nanostructures significantly affects their electronic properties. Despite a large number of experimental and theoretical studies dealing with the geometrical shape-dependent electronic properties of graphene nanostructures, experimental characterisation of their chemistry is clearly lacking. This is mostly due to the difficulties in preparing chemically-modified graphene nanostructures in a controlled manner and in identifying the exact chemistry of the graphene nanostructure on the atomic scale. Herein, we present scanning probe microscopic and first-principles characterisation of graphene nanostructures with different edge geometries and chemistry. Using the results of atomic scale electronic characterisation and theoretical simulation, we discuss the role of the edge geometry and chemistry on the electronic properties of graphene nanostructures with hydrogenated and oxidised linear edges at graphene boundaries and the internal edges of graphene vacancy defects. Atomic-scale details of the chemical composition have a strong impact on the electronic properties of graphene nanostructures, i.e., the presence or absence of non-bonding π states and the degree of resonance stability.

Electronic state of oxidized nanographene edge with atomically sharp zigzag boundaries.

Combined scanning tunneling microscopy (STM) and density functional theory (DFT) characterizations of the electronic state were performed on the zigzag edge of oxidized nanographene samples. The oxidized zigzag edge with atomically sharp boundaries was prepared by electrochemical oxidation of the graphite surface in aqueous sulfuric acid solution. Bias-dependent STM measurements demonstrated the presence of the edge state at the zigzag edges with local density of states (LDOS) split into two peaks around the Fermi level. Our DFT-based analysis showed that the two-peak structure of the edge state was due to the termination of the zigzag edge by carbonyl functional groups. The LDOS arising from the edge states was slowly dampened in the bulk at the carbonyl-terminated zigzag edges (~1.5 nm). This result is in clear contrast to the strongly localized edge states at hydrogenated zigzag edges in previous reports. The oxygen atoms in the carbonyl functional groups act as additional π sites at the edges; thus, the topology of the π electron network changes from "zigzag" to "Klein" type, leading to drastic modification of the edge states at the oxidized edges.

First total synthesis of antitumor natural product (+)- and (-)-pericosine A: determination of absolute stereo structure.

The first total synthesis of (+)- and (-)-pericosine A has been achieved, enabling the revision and determination of the absolute configuration of this antitumor natural product as methyl (3S,4S,5S,6S)-6-chloro-3,4,5-trihydroxy-1-cyclohexene-1-carboxylate. Every step of this total synthesis proceeded well with excellent stereoselectivity. Structures of the intermediates in crucial steps were confirmed by detailed 2D NMR analysis.

Relationship between phalangeal bone density and risk of vertebral fracture.

The aims of our study were to determine the relationship between bone mineral density (BMD) measurements of the phalanges obtained with the accuDEXA and recent vertebral fractures. To determine whether osteoarthritis of the hands affects phalangeal BMD measurements, and to illustrate the conversion of phalangeal BMD measurements to absolute fracture risk estimates for clinical application. The prospective Hawaii Osteoporosis Study began in 1981, and incident vertebral fractures were identified from serial radiographs obtained at approx 2-yr intervals. Vertebral fractures occurring between 1993 and 1994 and 1997 and 1998 were compared to phalangeal BMD measurements obtained in 1997-1998. A total of 199 women participated in this case-control study. The association of the phalangeal BMD measurements with vertebral fractures was examined in age-adjusted, logistic regression models. Results are expressed as odds ratios (ORs) per SD difference in the phalangeal BMD measurements. Osteoarthritis of the hands was graded according to the Kellgren-Lawrence scale. There were 34 incident fractures since the eighth examination in 1993-1994. For vertebral fractures, the OR per SD of phalangeal BMD was 1.5 (1.0-2.1). Phalangeal BMD was not influenced significantly by established osteoarthritis (p = 0.68). Phalangeal BMD measurements obtained with the accuDEXA device relate to recent vertebral fractures and can be used to identify women at high risk of fractures. The phalangeal BMD measurements obtained with this device are not significantly influenced by the presence of osteoarthritis of the hands.