147 research outputs found
Sensitivity Improvement of Highly Stretchable Capacitive Strain Sensors by Hierarchical Auxetic Structures
Highly stretchable sensors that can detect large strains are useful in deformable systems, such as soft robots and wearable devices. For stretchable strain sensors, two types of sensing methods exist, namely, resistive and capacitive. Capacitive sensing has several advantages over the resistive type, such as high linearity, repeatability, and low hysteresis. However, the sensitivity (gauge factor) of capacitive strain sensors is theoretically limited to 1, which is much lower than that of the resistive-type sensors. The objective of this study is to improve the sensitivity of highly stretchable capacitive strain sensors by integrating hierarchical auxetic structures into them. Auxetic structures have a negative Poisson\u27s ratio that causes increase in change in capacitance with applied strains, and thereby improving sensitivity. In order to prove this concept, we fabricate and characterize two sensor samples with planar dimensions 60 mm × 16 mm. The samples have an acrylic elastomer (3M, VHB 4905) as the dielectric layer and a liquid metal (eutectic gallium-indium) for electrodes. On both sides of the sensor samples, hierarchical auxetic structures made of a silicone elastomer (Dow Corning, Sylgard 184) are attached. The samples are tested under strains up to 50% and the experimental results show that the sensitivity of the sensor with the auxetic structure exceeds the theoretical limit. In addition, it is observed that the sensitivity of this sensor is roughly two times higher than that of a sensor without the auxetic structure, while maintaining high linearity (R2 = 0.995), repeatability (≥10^4 cycles), and low hysteresis
In-Orbit Demonstration of Propellant-Less Formation Flight with Momentum Exchange of Jointed Multiple CubeSats in the MAGNARO Mission
Recently, small satellites such as CubeSats have been applied to a variety of missions such as scientific observations and remote sensing. One of attractive applications that can be relatively easily achieved by small satellites are multi-satellite missions such as formation flight and constellation. As a new method to realize these multi-satellite missions, we propose a method to separate jointed multiple satellite magnetically to generate ΔV without thrusters. To demonstrate the proposed method, we are developing a 3U sized CubeSat called MAGNARO (MAGnetically separating NAnosatellite with Rotation for Orbit control)
Mitochondrial intermediate peptidase is a novel regulator of sirtuin-3 activation by caloric restriction
Sirtuin-3 (SIRT3) regulates mitochondrial quality and is involved in the anti-ageing and pro-longevity actions of caloric restriction (CR). Here, we show that CR upregulates the mature form of SIRT3 and mitochondrial intermediate peptidase (MIPEP), a mitochondrial signal peptidase (MtSPase), in white adipose tissue. We also demonstrate that upregulation of mature SIRT3 is dependent on MIPEP in 3T3-L1 cells, suggesting that MIPEP may contribute to the maintenance of mitochondrial quality during CRvia activation of SIRT3. This novel mechanism of SIRT3 activation through MIPEP facilitates the elucidation of additional molecular pathways of CR
Pathological analysis of spermatic dysfunction following testicular ischemia-reperfusion injury\n
Introduction & Objectives: Torsion, which may result in testicular ischemia, requires emergency surgery to restore testicular blood flow. However, the risk of spermatic dysfunction remains even if surgery is performed. The pathology of spermatic dysfunction in testicular ischemia-reperfusion injury (TIRI) remains unclear. A previous study showed the relevance of inflammation and oxidative stress in the other organs of ischemia-reperfusion injury. We hypothesized that inflammation and oxidative stress play key roles in causing spermatic dysfunction following TIRI. We investigated the pathophysiology of spermatic dysfunction in TIRI focusing on inflammatory changes using TIRI model mice. Materials and Methods: The study used C57BL/6J male mice aged 10 to 15 weeks. To create TIRI model mice, the unilateral (left side) testicular vessels were clamped using Dieffenbach clamps (Bulldog clamps) for 1 hour and de-clamped. The bilateral testes were removed at 0 (ischemic state), 1, 3, and 5 weeks after creating the TIRI model mice. Spermatic changes following TIRI were investigated by analyzing the histology of the testes and semen and assessing levels of inflammation and oxidative stress. Semen was collected from the bilateral cauda epididymites and investigated using the sperm motility analysis system (SMAS). Results: Histological analysis after hematoxylin-eosin staining showed tissue thickening in interstitial tissues at week 1 and 3 on the left (affected) testis, and week 1, 3 and 5 on the right (unaffected) testis. The infiltration of lymphocytes-predominant inflammatory cells were observed at week 1 and week 3 on the left (affected) testis. The destruction of ductal structures and giant cells were observed at weeks 3 and 5 on the left (affected) testis and week 5 on the right (unaffected) testis. SMAS showed significantly decreased spermatic concentration and motility in both testes of TIRI model mice compared with those of sham-operated mice at weeks 1, 3 and 5. Inflammation analysis using an inflammation-related proteome assay showed significantly increased levels of cytokines (IL-2, IL-3, IL-17A, and IL-23) and chemokines (CCL2, CCL5, CXCL1, and CX3CL1) at weeks 1, 3, and 5 in both testes of TIRI model mice. For the assessment of oxidative stress, enzyme-linked immuno-sorbent assay (ELISA) for 8-hydroxy-2’-deoxyguanosine (8-OHdG) was performed, which showed that levels of 8-OHdG were significantly increased in the left (affected) testis of TIRI model mice compared with that of sham-operated mice at all observation periods. Meanwhile, ELISA showed that levels of 8-OHdG in the right (unaffected) testis were significantly increased in TIRI model mice at weeks 3 and 5 compared with that of sham-operated mice. Conclusions: Spermatic dysfunction following TIRI is induced by inflammation and oxidative stress. Inflammation and oxidative stress may be novel regulatory factors to prevent spermatic dysfunction following TIRI
Pathophysiological analysis of detrusor overactivity following partial bladder outlet obstruction
Introduction: Detrusor overactivity (DO) following partial bladder outlet obstruction (PBOO) is a common urological condition in humans, with 50-70% patients with PBOO complicated with DO. The pathological mechanisms of DO following PBOO are largely unknown, but inflammatory changes may play a key role. We hypothesized that inflammation is important in the earlier pathophysiological phase before overproduction of oxidative stress in DO following PBOO. Therefore, we investigated the relationships among bladder function, ischemia, oxidative stress and inflammation in DO following PBOO in PBOO model mice. Materials and Methods: C57BL/6J male mice aged 10 to 15 weeks were used in the study. PBOO model mice were created surgically by ligation of the proximal urethra with 5-0 nylon suture under inhalation anesthesia. Sham-operated mice were used as controls. Pathophysiological changes in the bladder at 1, 3 and 5 weeks after creation of the PBOO model mice were compared with those in sham-operated mice using functional, histological, biochemical and immunohistochemical analyses. Results: Functional analysis using a pressure flow study showed increased maximum detrusor pressure at 1 week and DO from 3 to 5 weeks after creation of the PBOO model. Histological analysis using hematoxylin-eosin and Masson-Trichrome staining showed greater invasion of inflammatory cells and fibrosis in PBOO model mice compared with sham-operated mice at 3 and 5 weeks. Inflammatory cells were mainly present in interstitial tissue, and fibrosis gradually infiltrated from interstitial tissue to the muscular layer. Ischemia analysis showed significantlyincreased HIF-1α in PBOO model mice at all time points. Oxidative stress analysis indicated significantly increased levels of ROS from 1 week and 8-OHdG from 3weeks in PBOO model mice. An inflammation-related proteome assay showed high levels of colony stimulating factor (CSF) family proteins at 1 week and IL-2, IL-3, IL-17A, IL-23, MMP-3, MMP-9 and periostin from 3 to 5 weeks in PBOO model mice. Conclusions: Oxidative stress and inflammatory changes showed contemporaneous increase in pathophysiology of detrusor overactivity following partial bladder outlet obstruction. Especially, CSF family and ROS changes are showed in the early stage, and might be a predict marker in the pathophysiology of DO following PBOO at the early stage
Preventive effect of indoleamine 2,3-dioxygenase 1 inhibition on lipopolysaccharide-induced prostatitis
Introduction and Objectives: Bacterial infections are the main cause of acute prostatitis and are treated with appropriate antimicrobial therapy. However, approximately 5% of patients continue to have inflammatory symptoms even after receiving antibacterial therapy, leading to refractory conditions. Bacterial prostatitis requires additional therapy, focusing on inflammatory changes. Indoleamine 2,3-dioxygenase 1 (IDO1) catalysis is the first rate-limiting step of tryptophan metabolism. IDO1 is expressed in the prostate and plays a key role in the immune response. As the first step in investigating the relationship between acute prostatitis and IDO1, we investigated the preventive effect of IDO1 inhibition on lipopolysaccharide (LPS)- induced prostatitis using IDO knockout (Ido1 −/−) mice in this study. Materials and Methods: The study used Ido1 −/− and wild-type (Ido1 +/+) C57BL/6J malemice aged 10–15 weeks. LPS Escherichia coli O26 (100μg/PBS, 100μL) was administered transurethrally into the lower urinary tract to create a mouse model of LPS-induced prostatitis. The prostates were removed 1, 3, 5, and 7 days after creating the model mice. Histological, immunohistochemical, and biochemical analyses were used to compare the preventive effect in Ido1 −/− mice compared with that in Ido1+/+ mice. Results: HE staining showed suppression of ductal destruction following infiltration of inflammatory cells in Ido1 −/− mice compared with Ido1 +/+ mice. The enzyme-linked immunosorbent assay (ELISA) method was used for kynurenine pathway analysis, which showed significantly maintained tryptophan levels and decreased L-kynurenine levels in Ido1 −/− mice compared to Ido1 +/+ mice. The IDO1 assay in Ido1 +/+ mice showed significantly increased levels during all observation periods after creating the model compared with that under normal conditions. Immunofluorescent staining using five types of cytokines and chemokines (IL-2, IL-4, IL-17, CCL2, and CCL3) related to the pathophysiology of acute prostatitis showed decreased expression of these cytokines and chemokines in Ido1 -/- mice compared with Ido1 +/+ mice. Inflammation-related proteome assays showed decreased levels of IL-1β, IL-4, IL-5, IL-6, IL-17, CCL2, CCL3, CXCL1, CXCL11, and tissue inhibitor of matrix metalloproteinases (TIMP)-1 in Ido1 −/− mice compared with Ido1 −/− mice during all observation periods after model creation. Conclusions: IDO1 is involved in LPS-induced prostatitis through cytokines and chemokines. IDO1 inhibition contributes to the prevention of LPS-induced prostatitis. IDO1 inhibition has the potential to serve as an additional therapy for acute prostatitis
Changes in serum antibody titers after vaccination for COVID-19 and evaluation of post-vaccination health conditions
Introduction: The coronavirus disease 2019 (COVID-19) vaccine has preventive effects and high immunogenicity, but the outcomes of vaccination have not been widely reported. The goal of this study was to examine serum antibody titers before and after vaccination and to evaluate post-vaccination health conditions. Methods: The subjects were 2,304 medical workers (mean age 41 years) at Kawasaki Gakuen who agreed to participate in the study and underwent COVID-19 vaccination, beginning in March 2021. Serum IgG antibody titers for SARS-CoV-2 spike protein were measured before the first vaccination and 4 weeks after the second vaccination. Health conditions were observed for 4 weeks after the second vaccination. Results: The rates of seroconversion, seroprotection, and change in geometric mean antibody titer at 4 weeks after the second vaccination were 99.9%, 99.9%, and 2,685.5 (95% CI 587.8-5,319.2), respectively, suggesting high immunogenicity. After the first vaccination, pain, enlargement, and reddening occurred at the local injection site, and systemic side effects included fatigue, headache, physical pain, chill, nausea, and fever. After the second vaccination, the incidence of pain decreased, but those of other events increased. There were no serious side effects requiring hospitalization. In logistic regression analysis, sex, age, fever,chill, and lymph node enlargement after the second vaccination were associated with a change in antibody titer. Conclusions: Serum antibody titers suggested high immunogenicity of the COVID-19 vaccine and a health condition survey confirmed the safety of the vaccine. Systemic side effects may serve as an index of immunization (acquisition of antibody) by the vaccine
Species identification, antifungal susceptibility, and clinical feature association of Aspergillus section Nigri isolates from the lower respiratory tract
Species of Aspergillus section Nigri are generally identified by molecular genetics approaches, whereas in clinical practice, they are classified as A. niger by their morphological characteristics. This study aimed to investigate whether the species of Aspergillus section Nigri isolated from the respiratory tract vary depending on clinical diagnosis. Forty-four Aspergillus section Nigri isolates isolated from the lower respiratory tracts of 43 patients were collected from February 2012 to January 2017 at the National Hospital Organization (NHO) Tokyo National Hospital. Species identification was carried out based on β-tubulin gene analysis. Drug susceptibility tests were performed according to the Clinical and Laboratory Standards Institute (CLSI) M38 3rd edition, and the clinical characteristics were retrospectively reviewed. A. welwitschiae was isolated most frequently, followed by A. tubingensis. More than half of the A. tubingensis isolates exhibited low susceptibility to azoles in contrast to only one A. welwitschiae isolate. Approximately three quarters of the patients from whom A. welwitschiae was isolated were diagnosed with colonization, whereas more than half the patients from whom A. tubingensis was isolated were diagnosed with chronic pulmonary aspergillosis (CPA). More attention needs to be given to the drug choice for patients with CPA with Aspergillus section Nigri infection because A. tubingensis, which was found to be frequently azole-resistant, was the most prevalent in these patients
Status of adult outpatients with congenital heart disease in Japan: The Japanese Network of Cardiovascular Departments for Adult Congenital Heart Disease Registry
BackgroundThe Japanese Network of Cardiovascular Departments for Adult Congenital Heart Disease (JNCVD-ACHD) was founded in 2011 for the lifelong care of adult patients with congenital heart disease (ACHD patients). This network maintains the first Japanese ACHD registry.Methods and resultsFrom 2011 to 2019, the JNCVD-ACHD registered 54 institutions providing specialized care for ACHD patients in 32 of the 47 prefectures in Japan. The registry collected data on the disease profile for 24,048 patients from 50 institutions and the patient characteristics for 9743 patients from 24 institutions. The most common ACHDs were atrial septal defect (20.5 %), ventricular septal defect (20.5 %), tetralogy of Fallot (12.9 %), and univentricular heart (UVH)/single ventricle (SV; 6.6 %). ACHD patients without biventricular repair accounted for 37.0 % of the population. Also examined were the serious anatomical and/or pathophysiological disorders such as pulmonary arterial hypertension (3.0 %) including Eisenmenger syndrome (1.2 %), systemic right ventricle under biventricular circulation (sRV-2VC; 2.8 %), and Fontan physiology (6.0 %). The sRV-2VC cases comprised congenitally corrected transposition of the great arteries without anatomical repair (61.9 %) and transposition of the great arteries with atrial switching surgery (38.1 %). The primary etiology (86.4 %) for Fontan physiology was UVH/SV. In addition, developmental/chromosomal/genetic disorders were heterotaxy syndromes (asplenia, 0.9 %; polysplenia, 0.7 %), trisomy 21 (4.0 %), 22q11.2 deletion (0.9 %), Turner syndrome (0.2 %), and Marfan syndrome (1.1 %).ConclusionsAlthough the specific management of ACHD has systematically progressed in Japan, this approach is still evolving. For ideal ACHD care, the prospective goals for the JNCVD-ACHD are to create local networks and provide a resource for multicenter clinical trials to support evidence-based practice
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