239 research outputs found
Bayesian Inference of Absorption Spectra Based on Binomial Distribution
In this paper, we propose a Bayesian spectral deconvolution method for
absorption spectra. In conventional analysis, the noise mechanism of absorption
spectral data is never considered appropriately. In that analysis, the
least-squares method, which assumes Gaussian noise from the perspective of
Bayesian statistics, is frequently used. Since Bayesian inference is possible
by introducing an appropriate noise model for the data, we consider the
absorption process of a single photon to be a Bernoulli trial and develop a
Bayesian spectral deconvolution method based on binomial distribution. We have
evaluated our method on artificial data under several conditions by numerical
experiments. The results show that our method not only allows us to estimate
parameters with high accuracy from absorption spectral data, but also to infer
them even from absorption spectral data with large absorption rates where the
spectral structure is flattened, which was previously impossible to analyze
Bayesian Inference for Small-Angle Scattering Data
In this paper, we propose a method for estimating model parameters using
Small-Angle Scattering (SAS) data based on the Bayesian inference. Conventional
SAS data analyses involve processes of manual parameter adjustment by analysts
or optimization using gradient methods. These analysis processes tend to
involve heuristic approaches and may lead to local solutions.Furthermore, it is
difficult to evaluate the reliability of the results obtained by conventional
analysis methods. Our method solves these problems by estimating model
parameters as probability distributions from SAS data using the framework of
the Bayesian inference. We evaluate the performance of our method through
numerical experiments using artificial data of representative measurement
target models.From the results of the numerical experiments, we show that our
method provides not only high accuracy and reliability of estimation, but also
perspectives on the transition point of estimability with respect to the
measurement time and the lower bound of the angular domain of the measured
data.Comment: 31 pages, 25 figure
Magnetization dynamics and its scattering mechanism in thin CoFeB films with interfacial anisotropy
Studies of magnetization dynamics have incessantly facilitated the discovery
of fundamentally novel physical phenomena, making steady headway in the
development of magnetic and spintronics devices. The dynamics can be induced
and detected electrically, offering new functionalities in advanced electronics
at the nanoscale. However, its scattering mechanism is still disputed.
Understanding the mechanism in thin films is especially important, because most
spintronics devices are made from stacks of multilayers with nanometer
thickness. The stacks are known to possess interfacial magnetic anisotropy, a
central property for applications, whose influence on the dynamics remains
unknown. Here, we investigate the impact of interfacial anisotropy by adopting
CoFeB/MgO as a model system. Through systematic and complementary measurements
of ferromagnetic resonance (FMR), on a series of thin films, we identify
narrower FMR linewidths at higher temperatures. We explicitly rule out the
temperature dependence of intrinsic damping as a possible cause, and it is also
not expected from existing extrinsic scattering mechanisms for ferromagnets. We
ascribe this observation to motional narrowing, an old concept so far neglected
in the analyses of FMR spectra. The effect is confirmed to originate from
interfacial anisotropy, impacting the practical technology of spin-based
nanodevices up to room temperature.Comment: 23 pages,3 figure
Electric-field effect on the easy cone angle of the easy-cone state in CoFeB/MgO investigated by ferromagnetic resonance
Effects of dimensions and regularity on the mechanical properties of the smectic phase formed during orientation-induced crystallization of poly (ethylene terephthalate)
A fibrillar-shaped metastable smectic phase forms during orientation-induced crystallization of poly(ethylene terephthalate). We investigated the effects of dimensions and regularity of the smectic phase on the mechanical properties by high-precision X-ray measurements. The drawing stress dependence was 76-168 MPa and the spinning speed dependence of 250-2000 m/min. The proportion, persistence length, and thickness of the smectic phase achieved their maximum values at 0.3-0.4 ms after necking. At this time g(II) also reached a minimum value of 3.7%-4.3%. The persistence length increased linearly with the natural draw ratio of as-spun fibers at less than 1500 m/min. The maximum values of the proportion, persistence length, and thickness showed no dependence on the drawing stress; however, the proportion and persistence length increased more rapidly. The increase of d-spacing with drawing stress led to an apparent elastic modulus of approximately 40 GPa for the oriented molecular bundle.ArticlePOLYMER.164:163-173(2019)journal articl
Current smoking status may be associated with overt albuminuria in female patients with type 1 diabetes mellitus: a cross-sectional study
Background
There are very few clinical reports that have compared the association between cigarette smoking
and microangiopathy in Asian patients with type 1 diabetes mellitus (T1DM). The objective of this study was to
assess the relationships between urinary protein concentrations and smoking and gender-based risk factors among
patients with T1DM.
Methods
A cross-sectional study of 259 patients with T1DM (men/women = 90/169; mean age, 50.7 years) who
visited our hospital for more than 1 year between October 2010 and April 2011 was conducted. Participants
completed a questionnaire about their smoking habits. Patient characteristics included gender, age, body mass
index, blood pressure, hemoglobin A1c, lipid parameters, and microangiopathy. Diabetic nephropathy (DN) was
categorized as normoalbuminuria (NA), microalbuminuria (MA), or overt albuminuria (OA) on the basis of the
following urinary albumin/creatinine ratio (ACR) levels: NA, ACR levels less than 30 mg/g creatinine (Cr); MA, ACR
levels between 30 and 299 mg/g Cr; and OA, ACR levels over 300 mg/g Cr.
Results
The percentages of current nonsmokers and current smokers with T1DM were 73.0% (n = 189) and 27.0%
(n = 70), respectively. In addition, the percentage of males was higher than that of females (52.2% versus 13.6%) in
the current smoking population. The percentage of DN was 61.8% (n = 160) in patients with NA, 21.6% (n = 56) in
patients with MA, and 16.6% (n = 43) in patients with OA. The percentage of males among OA patients was also
higher than that of females (24.4% versus 12.4%). However, current smoking status was associated with OA in
females with T1DM only [unadjusted odds ratio (OR), 4.13; 95% confidence interval (CI), 1.45–11.73, P < 0.01;
multivariate-adjusted OR, 5.41; 95% CI, 1.69–17.30, P < 0.01].
Conclusions
Based on our results in this cross-sectional study of Asian patients with T1DM, smoking might be a
risk factor for OA among female patients. Further research is needed of these gender-specific results
CtBP1/BARS is an activator of phospholipase D1 necessary for agonist-induced macropinocytosis
Vesicular trafficking such as macropinocytosis is a dynamic process that requires coordinated interactions between specialized proteins and lipids. A recent report suggests the involvement of CtBP1/BARS in epidermal growth factor (EGF)-induced macropinocytosis. Detailed mechanisms as to how lipid remodelling is regulated during macropinocytosis are still undefined. Here, we show that CtBP1/BARS is a physiological activator of PLD1 required in agonist-induced macropinocytosis. EGF-induced macropinocytosis was specifically blocked by 1-butanol but not by 2-butanol. In addition, stimulation of cells by serum or EGF resulted in the association of CtBP1/BARS with PLD1. Finally, CtBP1/BARS activated PLD1 in a synergistic manner with other PLD activators, including ADP-ribosylation factors as demonstrated by in vitro and intact cell systems. The present results shed light on the molecular basis of how the ‘fission protein' CtBP1/BARS controls vesicular trafficking events including macropinocytosis
Deletion of both p62 and Nrf2 spontaneously results in the development of nonalcoholic steatohepatitis
Nonalcoholic steatohepatitis (NASH) is one of the leading causes of chronic liver disease worldwide. However, details of pathogenetic mechanisms remain unknown. Deletion of both p62/Sqstm1 and Nrf2 genes spontaneously led to the development of NASH in mice fed a normal chow and was associated with liver tumorigenesis. The pathogenetic mechanism (s) underlying the NASH development was investigated in p62:Nrf2 double-knockout (DKO) mice. DKO mice showed massive hepatomegaly and steatohepatitis with fat accumulation and had hyperphagia-induced obesity coupled with insulin resistance and adipokine imbalance. They also showed dysbiosis associated with an increased proportion of gram-negative bacteria species and an increased lipopolysaccharide (LPS) level in feces. Intestinal permeability was elevated in association with both epithelial damage and decreased expression levels of tight junction protein zona occludens-1, and thereby LPS levels were increased in serum. For Kupffer cells, the foreign body phagocytic capacity was decreased in magnetic resonance imaging, and the proportion of M1 cells was increased in DKO mice. In vitro experiments showed that the inflammatory response was accelerated in the p62:Nrf2 double-deficient Kupffer cells when challenged with a low dose of LPS. Diet restriction improved the hepatic conditions of NASH in association with improved dysbiosis and decreased LPS levels. The results suggest that in DKO mice, activation of innate immunity by excessive LPS flux from the intestines, occurring both within and outside the liver, is central to the development of hepatic damage in the form of NASH
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