Characteristics of Perceived Stress and Salivary Levels of Secretory Immunoglobulin A and Cortisol in Japanese Women With Premenstrual Syndrome

Background: Several studies have demonstrated the associations between Premenstrual Syndrome and perceived stress, and no studies quantifying stress based on biochemical parameters have been conducted. Objectives: The objective of this study was to examine the changes in biochemical parameters of stress and measured perceived stress during the menstrual cycle of women with premenstrual syndrome. Patients and Methods: A longitudinal observational study was conducted in 2010 in the Kansai region of Japan. Thirteen women with premenstrual syndrome and 11 controls, all with regular menstrual cycles, participated in this study. Salivary secretory immunoglobulin A (S-IgA) and cortisol levels were measured as biochemical parameters, and scores on the Stress Check List KM (SCL-KM) (Cronbach’s α in this study ranged from 0.76 to 0.84) were used to indicate perceived stress through two complete menstrual cycles. Before stress measurements were taken, premenstrual, menstrual and postmenstrual phases were confirmed based on records of basal body temperature across two menstrual cycles. Data analysis was performed using the Student’s t-test, analysis of variance with repeated measures, and Pearson’s correlation coefficient, as appropriate. Results: Both the postmenstrual S-IgA concentration and secretion rate were significantly lower in the group with premenstrual syndrome than in controls (P < 0.05). Premenstrual S-IgA concentrations were significantly higher than postmenstrual levels in the group with premenstrual syndrome (P < 0.05). No significant differences in cortisol levels were seen in either group during any phase. Premenstrual and postmenstrual phase SCL-KM scores were significantly higher in the group with premenstrual syndrome than in controls (P < 0.05). No significant changes in the SCL-KM scores were observed among menstrual cycle phases in either group. Postmenstrual S-IgA levels were negatively correlated with the SCL-KM score (P < 0.05). Conclusions: The stress due to psychosomatic changes in the menstrual cycle is associated with premenstrual syndrome. Measures of S-IgA, rather than cortisol or subjective responses to stress, may be most closely associated with PMS

High statistics calculations of quenched QCD spectrum using various quark sources

We present the results for the hadron spectrum calculated on 400 configurations using point source, wall source and 8-cubic sources, in quenched QCD with Wilson fermions at $\beta=6.0$ and $K=0.155$ on a $24^3 \times 54$ lattice. The results for the ground state masses obtained with three types of quark sources agree well with each other. Masses of the first excited states appear consistent with experimental values within large errors.Comment: 3 pages, 2 postscript figures, to appear in the Proceedings of LATTICE 93, Dallas, USA; preprint UTHEP-26

Nonquasiparticle states in the half-metallic ferromagnet simulated by the two-band Hubbard model

The density-matrix renormalization group method is used to study the three-band zigzag ladder model that simulates the electronic state of the t 2g-orbital system of the double string of the edge-shared CrO 6 octahedra in the half-metallic ferromagnet K2Cr 8O16. The saturated ferromagnetism caused by the double-exchange mechanism is thereby demonstrated. We also use the Lanczos exact-diagonalization technique on small clusters to study the two Hubbard chains coupled with the ferromagnetic exchange interaction, whereby we consider the nonquasiparticle states in the half-metallic ferromagnet that appear in the single-particle spectral function.Ministry of Education, Culture, Sports, Science and Technology of Japa

Theoretical study of the electronic states of hollandite vanadate K 2V8O16

Electronic states of hollandite vanadate K2V8O 16, a one-dimensional zigzag-chain system of t2g orbitals in a mixed valent state, are considered. We calculate the Madelung energies to determine the most stable charge-ordering pattern that is consistent with the observed superlattice structure. We then develop the strong-coupling perturbation theory to derive the effective spin-orbit Hamiltonian, starting from the triply-degenerate t2g orbitals in the VO6 octahedral structure. An exact-diagonalization technique is used on small clusters of this Hamiltonian to determine the orbital-ordering pattern and spin structures in the ground state. We thereby discuss the electronic and magnetic properties of K2 V8O16. © 2009 IOP Publishing Ltd.Ministry of Education, Culture, Sports, Science and Technology of Japan/18028008Ministry of Education, Culture, Sports, Science and Technology of Japan/18043006Ministry of Education, Culture, Sports, Science and Technology of Japan/185400338Ministry of Education, Culture, Sports, Science and Technology of Japan/19014004JSPS Research Fellowship for Young Scientist

Spin and mass excitations in the doped multiple spin exchange model on a triangular lattice: 3He on graphite

Using an exact-diagonalization technique on small clusters, we calculate the spin and density excitation spectra as well as the temperature dependence of the specific heat for the triangular-lattice t-J model with the multiple-spin exchange interactions, whereby we consider the low-energy excitations of the two-dimensional liquid 3He adsorbed on graphite. We find that, for a relevant set of the parameter values, the spectral weight for the spin excitations is concentrated on a very low-energy region, while that of the density excitations extends over a wide energy range, indicating the clear separation of their energy scales. The double-peak structure in the temperature dependence of the specific heat is also obtained. © 2009 IOP Publishing Ltd.Ministry of Education, Culture, Sports, Science and Technology of Japan/18028008Ministry of Education, Culture, Sports, Science and Technology of Japan/18043006Ministry of Education, Culture, Sports, Science and Technology of Japan/18540338Ministry of Education, Culture, Sports, Science and Technology of Japan/19014004JSPS Research Fellowship for Young Scientist

A new half-metallic ferromagnet K2Cr8O16 predicted by an ab-initio electronic structure calculation

The first-principles electronic structure calculation is carried out to predict that a chromium oxide K2Cr8O16 with the hollandite-type crystal structure should be a new half-metallic ferromagnet. We compare our results with recent experimental data which indicate the ferromagnetic-metal to ferromagnetic-insulator transition at T ∼ 90 K, as well as the paramagnetic-metal to ferromagnetic-metal transition at T ∼ 180 K. Based on the calculated electronic structures, we argue that the double-exchange mechanism is responsible for the observed saturated ferromagnetism and the formation of the incommensurate, long-wavelength density wave of spinless fermions caused by the Fermi-surface nesting may be the origin of the opening of the charge gap.Ministry of Education, Culture, Sports, Science and Technology of Japa

Rock-salt SnS and SnSe: Native Topological Crystalline Insulators

Unlike time-reversal topological insulators, surface metallic states with Dirac cone dispersion in the recently discovered topological crystalline insulators (TCIs) are protected by crystal symmetry. To date, TCI behaviors have been observed in SnTe and the related alloys Pb$_{1-x}$Sn$_{x}$Se/Te, which incorporate heavy elements with large spin-orbit coupling (SOC). Here, by combining first-principles and {\it ab initio} tight-binding calculations, we report the formation of a TCI in the relatively lighter rock-salt SnS and SnSe. This TCI is characterized by an even number of Dirac cones at the high-symmetry (001), (110) and (111) surfaces, which are protected by the reflection symmetry with respect to the ($\bar{1}$10) mirror plane. We find that both SnS and SnSe have an intrinsically inverted band structure and the SOC is necessary only to open the bulk band gap. The bulk band gap evolution upon volume expansion reveals a topological transition from an ambient pressure TCI to a topologically trivial insulator. Our results indicate that the SOC alone is not sufficient to drive the topological transition.Comment: 5 pages, 5 figure