422 research outputs found
Fingerprinting models of first-order phase transitions by the synergy between collider and gravitational-wave experiments
We investigate the sensitivity of future space-based interferometers such as
LISA and DECIGO to the parameters of new particle physics models which drive a
first-order phase transition in the early Universe. We first perform a Fisher
matrix analysis on the quantities characterizing the gravitational wave
spectrum resulting from the phase transition, such as the peak frequency and
amplitude. We next perform a Fisher analysis for the quantities which determine
the properties of the phase transition, such as the latent heat and the time
dependence of the bubble nucleation rate. Since these quantities are determined
by the model parameters of the new physics, we can estimate the expected
sensitivities to such parameters. We illustrate this point by taking three new
physics models for example: (1) models with additional isospin singlet scalars
(2) a model with an extra real Higgs singlet, and (3) a classically conformal
model. We find that future gravitational wave observations play
complementary roles to future collider experiments in pinning down the
parameters of new physics models driving a first-order phase transition.Comment: 64 pages, 35 figure
Development of refrigeration oil for use with R32
R32 has been applied as an air-conditioner refrigerant in Japan for a few years. Although its GWP is slightly higher than the limit of F-gas restriction, high COP is a key driving force for R32 system. Regarding refrigeration oil applied to R32, there are two main issues. First issue is miscibility with R32, because incumbent refrigeration oil for R410A is rather immiscible to R32. Second issue is lubricity. When refrigerant is miscible well with refrigeration oil, generally, dissolved refrigerant reduce viscosity of refrigerant-oil mixture. Lower viscosity results in, lower lubricity, and finally, it would cause wear of sliding parts, compressor durability shortage, insufficient sealing, or reduced COP. At the earlier stage, several refrigeration oils miscible with R32 have been proposed. However, we have experienced wearing problems on surface of a main shaft in R32 system with such refrigeration oils, for example. Those problems were not found in R410A systems. We assumed there is some different mechanism on sliding parts in R32 systems comparing with current refrigerant systems. We focused on viscosity of refrigerant – oil mixture, which could be correlated to lubricity. Then, we found that viscosity of R32 – refrigeration oil mixture is extremely lower than that of R410A – refrigeration oil. Together with results of wearing problem in sliding parts, which are not worn by fluid lubrication in general, we assumed that oil film is formed insufficiently on the surface due to the extreme low viscosity of the mixture. Our goal of development of refrigeration oil for R32 was reset to balance miscibility and lubricity, which is trade-off normally. Through various studies, finally, we found a new base oil to meet our goal, which makes us possible to achieve not only high viscosity of the mixture, but also good miscibility with R32. Its excellent characteristics on lubricity and miscibility are also confirmed by several compressor tests
Evaluation of the histological and mechanical features of tendon healing in a rabbit model
Objectives
This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing.
Materials and Methods
A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation.
Results
While the SHG light intensity of the healing tendon samples was significantly lower than that of the uninjured tendon samples, 2D Fourier transform SHG images showed a clear difference in collagen fibre structure between the uninjured and the healing samples, and among the healing samples. The mean intensity of the SHG image showed a moderate correlation (R2 = 0.37) with Young’s modulus obtained from the tensile testing.
Conclusion
Our results indicate that SHG microscopy may be a potential indicator of tendon healing
Effects of safflower seed extract on arterial stiffness
Safflower seed extract (SSE) contains characteristic polyphenols and serotonin derivatives (N-( p-coumaroyl) serotonin and N-feruloylserotonin), which are reported to inhibit oxidation of low-density lipoprotein (LDL), formation of atherosclerotic plaques, and improve arterial stiffness as assessed by pulse wave analysis in animal models. The effects of long-term supplementation with SSE on arterial stiffness in human subjects were evaluated. This doubleblind, placebo-controlled study was conducted in 77 males (35–65 years) and 15 postmenopausal females (55–65 years) with high-normal blood pressure or mild hypertension who were not undergoing treatment. Subjects received SSE (70 mg/day as serotonin derivatives) or placebo for 12 weeks, and pulse wave measurements, ie, second derivative of photoplethysmogram (SDPTG), augmentation index, and brachial-ankle pulse wave velocity (baPWV) were conducted at baseline, and at weeks 4, 8, and 12. Vascular age estimated by SDPTG aging index improved in the SSE-supplemented group when compared with the placebo group at four (P = 0.0368) and 12 weeks (P = 0.0927). The trend of augmentation index reduction (P = 0.072 versus baseline) was observed in the SSE-supplemented group, but reduction of baPWV by SSE supplementation was not observed. The SSE-supplemented group also showed a trend towards a lower malondialdehyde-modified-LDL autoantibody titer at 12 weeks from baseline. These results suggest long-term ingestion of SSE in humans could help to improve arterial stiffness
Effects of single administration of Rokumi-gan (TJ-87) on serum amino acid concentration of 6 healthy Japanese male volunteers
Rokumi-gan (TJ-87) has beneficial effects on renal diseases, including pollakisuria, dysuria and edema. We previously reported that its long-term administration clinically improved serum protein concentration and edema in renal failure. In this study, we focused on amino acid/protein contents in Rokumi-gan as one of its effectors. Commercially prepared Rokumi-gan contained arginine, aspartate and glutamate at the high levels, alanine, phenylalanine and serine at the moderate levels, and glycine, histidine, isoleucine, leucine, lysine and valine at the low levels. To examine effects of Rokumi-gan on serum amino acid concentrations, 6 healthy Japanese volunteers were treated with commercially prepared Rokumi-gan, an amino acid mixture, and lactose. In subjects treated with an amino acid mixture containing similar amounts of amino acids in Rokumi-gan (10 g), or lactose, serum amounts of many amino acids, except for arginine, gradually and significantly decreased until 6 hr after their treatments. In contrast, a single treatment with Rokumi-gan (10 g) increased serum levels of several amino acids, alanine, arginine, glutamate, glycine and serine. Serum concentrations of almost of all tested amino acids showed the peak value 1-2 hr after administration, and they were sustained at the basal level even 6 hr after the treatment. Our present results suggest that Rokumi-gan may be a beneficial amino acid supplier, because it could sustain serum amino acid concentration at the higher level than an amino acid mixture supplement
Partial Purification and Chraracterization of Dendritic Cell Differentiation Factor
Previously, we reported that interleukin-2 (IL-2)-stimulated helper T cells produced an unknown soluble factor which induced dendritic cell-like differentiation in primary cultures of monocytic leukemia cells and we referred to this factor as dendritic cell differentiation factor (DCDF). In this study, we attempted to purify and characterize DCDF and investigated its biological effect on normal human monocytes. Gel filtration chromatography indicated that the molecular weight of DCDF is approximately 30-35 kDa. Chromatofocusing indicated that the isoelectric point of DCDF is approximately 5.0. DCDF, partially purified by subsequent gel filtration, chromatofocusing, and hydrophobic chromatography, significantly enhanced the HLA-DR expression of normal human monocytes and a human monocytic leukemia cell line, THP-1. This biological activity was not neutralized by any known antibodies to human cytokines. DCDF significantly amplified the T-cell stimulatory activity of monocytes in the allogeneic mixed leukocyte reaction (MLR). Moreover, DCDF significantly enhanced IL-1 beta and IL-6 production by monocytes in a dose-dependent manner. These results suggest that DCDF is a novel human cytokine which stimulates the accessory cell function of monocytes.</p
Nonreciprocal surface acoustic wave propagation via magneto-rotation coupling
One of the most fundamental forms of magnon-phonon interaction is an
intrinsic property of magnetic materials, the "magnetoelastic coupling". This
particular form of interaction has been the basis for describing magnetic
materials and their strain related applications, where strain induces changes
of internal magnetic fields. Different from the magnetoelastic coupling, more
than 40 years ago, it was proposed that surface acoustic waves may induce
surface magnons via rotational motion of the lattice in anisotropic magnets.
However, a signature of this magnon-phonon coupling mechanism, termed
magneto-rotation coupling, has been elusive. Here, we report the first
observation and theoretical framework of the magneto-rotation coupling in a
perpendicularly anisotropic ultra-thin film Ta/CoFeB(1.6 nm)/MgO, which
consequently induces nonreciprocal acoustic wave attenuation with a
unprecedented ratio up to 100 rectification at the theoretically predicted
optimized condition. Our work not only experimentally demonstrates a
fundamentally new path for investigating magnon-phonon coupling, but also
justify the feasibility of the magneto-rotation coupling based application.Comment: 30 pages, 12 figure
Household income relationship with health services utilization and healthcare expenditures in people aged 75 years or older in Japan: A population-based study using medical and long-term care insurance claims data
Background: This study aimed to determine whether there are disparities in healthcare services utilization according to household income among people aged 75 years or older in Japan.Methods: We used data on medical and long-term care (LTC) insurance claims and on LTC insurance premiums and needs levels for people aged 75 years or older in a suburban city. Data on people receiving public welfare were not available. Participants were categorized according to household income level using LTC insurance premiums data. The associations of low income with physician visit frequency, length of hospital stay (LOS), and medical and LTC expenditures were evaluated and adjusted for 5-year age groups and LTC needs level.Results: The study analyzed 12,852 men and 18,020 women, among which 13.3% and 41.5%, respectively, were categorized as low income. Participants with low income for both genders were more likely to be functionally dependent. In the adjusted analyses, lower income was associated with fewer physician visits (incidence rate ratio [IRR] 0.90; 95% confidence interval [CI], 0.87–0.92 for men and IRR 0.97; 95% CI, 0.95–0.99 for women), longer LOS (IRR 1.98; 95% CI, 1.54–2.56 and IRR 1.42; 95% CI, 1.20–1.67, respectively), and higher total expenditures (exp(β) 1.09; 95% CI, 1.01–1.18 and exp(β) 1.09; 95% CI, 1.05–1.14, respectively).Conclusions: This study suggests that older people with lower income had fewer consultations with physicians but an increased use of inpatient services. The income categorization used in this study may be an appropriate proxy of socioeconomic status
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