208 research outputs found
Dense ceramic coatings deposited by aerosol deposition for multilayered architecture towards thermal/environmental barrier coatings
The demands for thermal/environmental barrier coatings (T/EBCs) have been increased as the operating temperature of gas turbines increased in harsh environment [1]. Multilayered and multifunctional coatings are required for advanced T/EBCs [2], varied from porous insulative layer to dense environmental barrier layer. Aerosol deposition (AD) method is a unique deposition method that enables the deposition of dense ceramic coatings with high adhesion strength without melting of injected powder based on room temperature impact consolidation (RTIC) phenomena [3-5]. Thus, it will be interesting to apply this process for T/EBC applications. However, in order to apply the AD method to these applications, the deposition rate and the ability of three-dimensional coverage should be improved. Mori et al. preliminary reported that the introduction of plasma assistance drastically improved the deposition rate for lead zirconate titanate [6]. Thus, it would be worth to try to enhance aerosol deposition by introduction of plasma assistance [7]. The use of mesoplasma flow, which is transitional state from thermal plasma to low-pressure plasma, is the key to the deposition [8]. Fine powder of 8-wt% yttria-stabilized zirconia was sprayed by an rf-inductively coupled plasma at a reduced pressure. The effect of plasma assistance was confirmed at the power input of several kilowatts, which was much smaller compared to conventional plasma spray. Coatings with uniform thickness of 5-20 µm was obtained. The Vickers hardness of the coating reached to 1200 HV. This coating will be useful for the architecture of multilayered advanced T/EBCs.
References
[1] J. M. Drexler et al., Adv. Mater., 23 (2011) 2419-2424.
[2] V. Viswanathan et al., J. Am. Ceram. Soc., 97 (2014) 2770-2778.
[3] J. Akedo and M. Levedev, Jpn. J. Appl. Phys. Part 1, 38 (1999) 5397-5401.
[4] J. Akedo, J. Am. Ceram. Soc. 89 (2006) 1834-1839.
[5] J. Akedo, J. Therm. Spray Technol. 17 (2008) 181-198.
[6] M. Mori et al., Proc. IEEE Int. Symp. Appl. Ferroelectric. 1-2 (2007) 454-456.
[7] A. Vardelle et al., J. Therm. Spray Technol. 25 (2016) 1376-1440 (J. Akedo and K. Shinoda, Section 2.2, 1379-1383).
[8] T. Yoshida, Pure Appl. Chem. 78 (2006) 1093-1107
Citizen science "Thundercloud Project" -- multi-point radiation measurements of gamma-ray glows from accelerated electrons in thunderstorms
38th International Cosmic Ray Conference (ICRC2023), 26 July - 3 August, 2023, Nagoya, JapanIt has been a long-standing question whether cosmic rays promote the triggering of lightning and how cosmic-ray air showers interact with the electric field of thunderclouds. The strong electric field in the thunderclouds accelerates electrons to the relativistic regime, of which seed electrons are thought to be supplied from cosmic-ray air shower. Such relativistic electrons emit bremsstrahlung photons in gamma rays, which have been detected by on-ground measurements called gamma-ray glows. Low-altitude winter thunderstorm in Japan provides an ideal environment for observations of gamma-ray glows. We newly launched the citizen science ``Thundercloud Project" to construct a multi-point radiation mapping campaign for glows from winter thunderstorms around Kanazawa, Japan. We developed a new handy radiation monitor and shipped about 60 detectors to citizen supporters. The radiation data are stored in the microSD cards in the detectors, and a part of them is remotely sent to the web server so that researchers and supporters can watch the real-time data. In addition, an automatic alert is sent to public Twitter from the server when a glow is detected. The purpose of this project is (1) to characterize the methodological condition of electron acceleration, (2) to investigate whether accelerated relativistic electrons can enhance the chance of the initiation of lightning discharges, and (3) to find a new way of the citizen science to join in the cutting edge science in the physics field. Here we report this growing citizen science project and examples of successful gamma-ray glow observations. Our first scientific result from this citizen science project was published in Tsurumi et al., GRL 2023, where we reported lightning discharges started in or near the electron acceleration site of a gamma-ray glow
Intraventricular glioneuronal tumor with disseminated lesions at diagnosis - a case report -
A 55-year-old man presented with a large tumor in his lateral ventricles. Magnetic resonance imaging revealed disseminated lesions in the third and fourth ventricles at the time of diagnosis. The patient underwent a partial removal of the tumor in the lateral ventricles. Histologically, the surgical specimens showed glioneuronal differentiation with ganglion or ganglioid cells, Rosenthal fibers, oligodendroglia-like honeycomb appearances, a spongy pattern, perivascular pseudorosettes, and many hyalinized blood vessels. Papillary structure was not observed. The neuronal component showed a moderately high labeling index of Ki-67/MIB-1. We diagnosed this tumor as atypical intraventricular glioneuronal tumor. The disseminated lesions disappeared after chemoradiation therapy with temozolomide, and the residual tumors in the lateral ventricles remained stable for 3 years after the surgery. We discuss the pathological diagnosis, therapy and clinical course with review of the literatures
Effects of cilostazol against the progression of carotid IMT in symptomatic ischemic stroke patients
Characterization of age-related gene expression profiling in bone marrow and epididymal adipocytes
<p>Abstract</p> <p>Background</p> <p>While an increase in bone marrow adiposity is associated with age-related bone disease, the function of bone marrow adipocytes has not been studied. The aim of this study was to characterize and compare the age-related gene expression profiles in bone marrow adipocytes and epididymal adipocytes.</p> <p>Results</p> <p>A total of 3918 (13.7%) genes were differentially expressed in bone marrow adipocytes compared to epididymal adipocytes. Bone marrow adipocytes revealed a distinct gene profile with low expression of adipocyte-specific genes peroxisome proliferator-activated receptor gamma (PPARγ), fatty acid binding protein 4 (FABP4), perilipin (Plin1), adipsin (CFD) and high expression of genes associated with early adipocyte differentiation (CCAAT/enhancer binding protein beta (C/EBPβ), regulator of G-protein signaling 2 (RGS2). In addition, a number of genes including secreted frizzled related protein 4 (SFRP4), tumor necrosis factor α (TNFα), transforming growth factor beta 1(TGFβ1), G-protein coupled receptor 109A (GPR109A) and interleukin 6 (IL-6), that could affect adipose-derived signaling to bone are markedly increased in bone marrow adipocytes. Age had a substantial effect on genes associated with mitochondria function and inflammation in bone marrow adipocytes. Twenty seven genes were significantly changed with age in both adipocyte depots. Among these genes, IL6 and GPR109A were significantly reduced with age in both adipocyte depots.</p> <p>Conclusions</p> <p>Overall, gene profiling reveals a unique phenotype for primary bone marrow adipocytes characterized by low adipose-specific gene expression and high expression of inflammatory response genes. Bone marrow and epididymal adipocytes share a common pathway in response to aging in mice, but age has a greater impact on global gene expression in epididymal than in bone marrow adipocytes. Genes that are differentially expressed at greater levels in the bone marrow are highly regulated with age.</p
Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial
Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie
Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial
Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials.
Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure.
Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen.
Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
Stress-induced adaptive morphogenesis in bacteria
Bacteria thrive in virtually all environments. Like all other living organisms, bacteria may encounter various types of stresses, to which cells need to adapt. In this chapter, we describe how cells cope with stressful conditions and how this may lead to dramatic morphological changes. These changes may not only allow harmless cells to withstand environmental insults but can also benefit pathogenic bacteria by enabling them to escape from the immune system and the activity of antibiotics. A better understanding of stress-induced morphogenesis will help us to develop new approaches to combat such harmful pathogens.Microbial Biotechnolog
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