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ABSTRACT Aims/Introduction Insulin resistance syndrome and lipoatrophic diabetes are rare conditions characterized by the development of treatment‐refractory diabetes with severe insulin resistance. We recently conducted a 24 week, multicenter, single‐arm trial (EMPIRE‐01) that demonstrated a certain level of effectiveness and safety of empagliflozin for these conditions. To evaluate treatment safety over a longer period, we have now performed an additional 28 week trial (EMPIRE‐02) that followed on from EMPIRE‐01. Materials and Methods The primary and secondary outcomes were safety and efficacy evaluations, respectively. All eight subjects of the EMPIRE‐01 trial participated in EMPIRE‐02. Results Twenty adverse events (AEs) were recorded among five individuals during the combined 52 week treatment period of both trials. Whereas one case of chronic hepatitis B was moderate in severity, all other AEs were mild. There were thus no serious AEs or events necessitating discontinuation or suspension of treatment or a reduction in drug dose. Whereas ketoacidosis or marked increases in serum ketone body levels were not observed, the mean body mass of the subjects was decreased slightly after completion of EMPIRE‐02. The improvement in mean values of glycemic parameters observed in EMPIRE‐01 was not sustained in EMPIRE‐02, mostly because of one individual whose parameters deteriorated markedly, likely as a result of nonadherence to diet therapy. The improvement in glycemic parameters was sustained during EMPIRE‐02 after exclusion of this subject from analysis. Conclusions Empagliflozin demonstrated a certain level of safety and efficacy for the treatment of insulin resistance syndrome and lipoatrophic diabetes over 52 weeks, confirming its potential as a therapeutic option.

Abstract This study aimed to investigate how intermittent hyperoxic exposure (three cycles of 21% O2 [10 min] and 30% O2 [15 min]) affects exercise performance in mice. Three hours after the acute exposure, there was an observed increase in mRNA levels of phosphofructokinase (Bayes factor [BF] ≥ 10), mitochondrial transcription factor‐A (BF ≥10), PPAR‐α (BF ≥3), and PPAR‐γ (BF ≥3) in the red gastrocnemius muscle (Gr). Four weeks of exercise training under intermittent (INT), but not continuous (HYP), hyperoxia significantly (BF ≥30) increased maximal exercise capacity compared to normoxic exercise‐trained (ET) group. INT group exhibited significantly higher activity levels of 3‐hydroxyacyl‐CoA‐dehydrogenase (HAD) in Gr (BF = 7.9) compared to ET group. Pyruvate dehydrogenase complex activity levels were significantly higher in INT group compared to ET group in white gastrocnemius, diaphragm, and left ventricle (BF ≥3). NT‐PGC1α protein levels in Gr (BF = 7.7) and HAD activity levels in Gr (BF = 6.9) and soleus muscles (BF = 3.3) showed a significant positive correlation with maximal work values. These findings suggest that exercise training under intermittent hyperoxia is a beneficial strategy for enhancing endurance performance by improving fatty acid and pyruvic acid utilization.

Optical wireless power transmission (OWPT) attracts attention because it enables wireless power transfer over longer distances than current wireless power transfer methods, irradiating laser light to a light-receiving element. In this study, an OWPT system was investigated under water and deep seawater using visible lasers with low optical absorption loss in water. Three laser beams (450 nm, 532 nm, and 635 nm) were transmitted through 30 cm, 60 cm, and 90 cm long tanks filled with tap water and deep seawater and were irradiated to 1.0 × 1.0 cm2 GaInP solar cells. The light reaching rate (ηop) of laser light and the system efficiency (ηsys) of the system (excluding the laser efficiency) were investigated. GaInP solar cells showed photo-electric conversion efficiencies of 30.6%, 40.3%, and 39.3% for 450 nm, 532 nm, and 635 nm irradiations, respectively. As a result, a 532 nm laser through a 90 cm water tank in tap water showed a 78.4% ηop and a 30.8% ηsys. Under deep seawater, a 532 nm laser through a 90 cm tank exhibited a 58.3% ηop and a 23.5% ηsys. A 532 nm green laser showed a higher efficiency than the other 450 nm and 635 nm lasers in this underwater system using GaInP solar cells.

ABSTRACT Aims/Introduction The aim of the study was to compare two continuous glucose monitoring (CGM) systems, intermittently scanned CGM (isCGM) and real‐time CGM (rtCGM), to determine which system achieved better glycemic control in pediatric patients. Materials and Methods We carried out a retrospective cohort study of children and adolescents with type 1 diabetes, and compared the time in range (70–180 mg/dL), time below range (180 mg/dL), and estimated glycated hemoglobin levels between patients on isCGM and rtCGM. Results Of the 112 participants, 76 (67.9%) used isCGM and 36 (32.1%) used rtCGM for glycemic management. Patients on rtCGM had significantly greater time in range (57.7 ± 12.3% vs 52.3 ± 12.3%, P = 0.0368), and had significantly lower time below range (4.3 ± 2.7% vs 10.2% ± 5.4%, P

Abstract Aims/Introduction We examined the impact of scanning frequency with flash glucose monitoring on glycemic control in children and adolescents with type 1 diabetes. Materials and Methods The study included 85 patients, aged 14.0 ± 0.5 years, with type 1 diabetes. The median time in the target glucose range (TIR) and glycosylated hemoglobin (HbA1c) values were 50.0 ± 1.4% and 7.5 ± 0.1%, respectively. Results The median scanning frequency using flash glucose monitoring was 12.0 ± 0.4 times/day. Scanning frequency showed a significant positive correlation with TIR and an inverse correlation with HbA1c. Scanning frequency was identified to be the determinant of TIR and HbA1c by using multivariate analysis. The participants whose scanning frequency was 12 times/day were categorized as the high‐frequency group (n = 45). Patients in the high‐frequency group were more likely to be treated with insulin pumps compared with those in the low‐frequency group; however, this difference was not significant (21.3 vs 5.3%, P = 0.073). The high‐frequency group showed significantly greater TIR than the low‐frequency group (57 ± 1.6 vs 42 ± 1.7%, P = 0.002). Furthermore, the high‐frequency group showed significantly lower HbA1c levels than the low‐frequency group (6.8 ± 0.1 vs 8.0 ± 0.1%, P 12 times/day might contribute to better glycemic outcomes in real‐world practice in children with type 1 diabetes.

Abstract This study was designed to (1) investigate the effects of acute exercise under intermittent hypoxia on muscle mRNA and protein levels, and (2) clarify the mechanisms by which exercise under intermittent hypoxia improves endurance capacity. Experiment‐1: Male mice were subjected to either acute endurance exercise, exercise under hypoxia (14% O2), exercise under intermittent hypoxia (Int, three cycles of room air [10 min] and 14% O2 [15 min]). At 3 h after exercise under intermittent hypoxia, sirtuin‐6 mRNA levels and nuclear prolyl hydroxylases‐2 protein levels were significantly upregulated in white gastrocnemius muscle in the Int group. Experiment‐2: Mice were assigned to sedentary control (Sed), normoxic exercise‐trained (ET), hypoxic exercise‐trained (HYP) or exercise‐trained under intermittent hypoxia (INT) groups. Exercise capacity was significantly greater in the INT group than in the ET and HYP group. Activity levels of citrate synthase were significantly greater in the INT group than in the HYP group in soleus (SOL) and red gastrocnemius muscles. In SOL, nuclear N‐terminal PGC1α levels were considerably increased by the INT training (95% confidence interval [CI]: 1.09–1.79). The INT significantly increased pyruvate dehydrogenase complex activity levels in left ventricle (LV). Monocarboxylate transporter‐4 protein levels were significantly increased after the INT training in LV. Capillary‐to‐fiber ratio values were significantly increased in SOL and were substantially increased in LV (CI: 1.10–1.22) after the INT training. These results suggest that exercise training under intermittent hypoxia represents a beneficial strategy for increasing endurance performance via improving metabolic properties and capillary profiles in several hind‐leg muscles and the heart.

Abstract Hyperbaric exposure (1.3 atmospheres absolute with 20.9% O2) for 1 h a day was shown to improve exercise capacity. The present study was designed to reveal whether the daily exposure time affects exercise performance and metabolism in skeletal and cardiac muscles. Male mice in the training group were housed in a cage with a wheel activity device for 7 weeks from 5 weeks old. Trained mice were then subjected to hybrid training (HT, endurance exercise for 30 min followed by sprint interval exercise for 30 min). Hyperbaric exposure was applied following daily HT for 15 min (15HT), 30 min (30HT), or 60 min (60HT) for 4 weeks. In the endurance capacity test, maximal work values were significantly increased by 30HT and 60HT. In the left ventricle (LV), activity levels of 3‐hydroxyacyl‐CoA‐dehydrogenase, citrate synthase, and carnitine palmitoyl transferase (CPT) 2 were significantly increased by 60HT. CPT2 activity levels were markedly increased by hyperbaric exposure in red gastrocnemius (Gr) and plantaris muscle (PL). Pyruvate dehydrogenase complex activity values in PL were enhanced more by 30HT and 60HT than by HT. Protein levels of N‐terminal isoform of PGC1α (NT‐PGC1α) protein were significantly enhanced in three hyperbaric exposed groups in Gr, but not in LV. These results indicate that hyperbaric exposure for 30 min or longer has beneficial effects on endurance, and 60‐min exposure has the potential to further increase performance by facilitating fatty acid metabolism in skeletal and cardiac muscles in highly trained mice. NT‐PGC1α may have important roles for these adaptations in skeletal muscle.

Abstract The author previously reported that short‐duration intermittent hypoxia had additive effects on improvements in endurance capacity by enhancing fatty acid metabolism. The present study was designed to investigate the effects of short‐duration intermittent hypoxia on endurance capacity, metabolic enzyme activity, and protein levels associated with mitochondrial biogenesis in well‐trained mice. Mice in the training group were housed in a cage with a running wheel for 7 weeks from 5 weeks old. Voluntary running markedly increased maximal work values by 5.0‐fold. Trained mice were then subjected to either endurance treadmill training (ET) for 60 min or hybrid training (HT, ET for 30 min followed by sprint interval exercise (5‐sec run‐10‐sec rest) for 30 min) with (H‐ET or H‐HT) or without (ET or HT) short‐duration intermittent hypoxia (4 cycles of 12–13% O2 for 15 min and 20.9% O2 for 10 min) for 4 weeks. Maximal endurance capacity was markedly greater in the H‐ET and H‐HT than ET and HT groups, respectively. H‐ET and H‐HT increased activity levels of 3‐hydroxyacyl‐CoA‐dehydrogenase in oxidative muscle portion and pyruvate dehydrogenase complex in glycolytic muscle portion. These activity levels were significantly correlated with maximal endurance capacity. Protein levels of dynamin‐related protein‐1 were increased more by H‐ET and H‐HT than by ET and HT, but were not significantly correlated with maximal work. These results suggest that intermittent hypoxic exposure has beneficial effects on endurance and hybrid training to improve the endurance capacity via improving fatty acid and pyruvate oxidation in highly trained mice.

In this study, simulations are conducted using a network model to examine how the macroscopic network in the brain is related to the complexity of activity for each region. The network model is composed of multiple neuron groups, each of which consists of spiking neurons with different topological properties of a macroscopic network based on the Watts and Strogatz model. The complexity of spontaneous activity is analyzed using multiscale entropy, and the structural properties of the network are analyzed using complex network theory. Experimental results show that a macroscopic structure with high clustering and high degree centrality increases the firing rates of neurons in a neuron group and enhances intraconnections from the excitatory neurons to inhibitory neurons in a neuron group. As a result, the intensity of the specific frequency components of neural activity increases. This decreases the complexity of neural activity. Finally, we discuss the research relevance of the complexity of the brain activity.

In recent years, many experiments have investigated the impact of dietary amino acid supplementation on improvements in muscle strength and endurance capacity. However, it is unclear whether this supplementation causes vascular remodelling in skeletal muscle. This review focused on the effects of L-arginine and/or L-ornithine supplementation on capillary growth in cardiac and skeletal muscles. Although the chronic administration of 4% L-arginine did not improve capillarization in rat cardiac and hind-leg muscles, it facilitated exercise-induced capillary growth via vascular endothelial growth factor (VEGF) protein upregulation. In middle-aged rats, moderate intensity endurance training for 6 weeks did not cause capillary growth, whereas training with L-arginine supplementation led to an improvement in capillarization in the hind-leg muscle and left ventricle by promoting VEGF and endothelial nitric oxide synthase (eNOS) protein expression. The administration of L-arginine and L-ornithine for 6 weeks caused a marked increase in capillarization in rat skeletal muscle via the downregulation of endostatin and upregulation of VEGF-R2 protein expression. Moreover, this supplementation facilitated exercise-induced improvements in capillarization in the hind-leg muscles via the downregulation of endostatin and upregulation of VEGF and eNOS protein levels. The evidence presented in this review indicates that L-arginine and/or L-ornithine administration may facilitate capillary growth and endurance exercise capacity. Furthermore, this supplementation may be a useful therapeutic intervention for ischemic-related diseases.

The present study was designed to investigate the effects of short-duration intermittent hypoxia on endurance capacity, metabolic enzyme activity, and protein levels associated with mitochondrial biogenesis in well-trained mice. Mice in the training group were housed in a cage with a running wheel for 7 weeks from 5 weeks old. Voluntary running markedly increased maximal work values by 5.0-fold. Trained mice were then subjected to either endurance treadmill training (ET) for 60 min or hybrid training (HT, ET for 30 min followed by sprint interval exercise (5-sec run-10-sec rest) for 30 min) with (H-ET or H-HT) or without (ET or HT) short-duration intermittent hypoxia (4 cycles of 12-13% O2 for 15 min and 20.9% O2 for 10 min) for 4 weeks. Maximal endurance capacity was markedly greater in the H-ET and H-HT than ET and HT groups, respectively. H-ET and H-HT increased activity levels of 3-hydroxyacyl-CoA-dehydrogenase in oxidative muscle portion and pyruvate dehydrogenase complex in glycolytic muscle portion. These activity levels were significantly correlated with maximal endurance capacity. Protein levels of dynamin-related protein-1 were increased more by H-ET and H-HT than by ET and HT, but were not significantly correlated with maximal work. These results suggest that intermittent hypoxic exposure has beneficial effects on endurance and hybrid training to improve the endurance capacity via improving fatty acid and pyruvate oxidation in highly trained mice. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to investigate the effects of acute short-duration intermittent hyperoxia on muscle mRNA expression levels. Methods: Male MCH(ICR)/jcl mice were subjected to either acute 75-min hyperoxia (30% O2, HYP, n = 5), acute short-duration intermittent hyperoxia (30% O2 for 15-min followed by room air for 10 min, 3 times, INT, n = 5), or non-treated control (CNT, n = 5). At 3 h after each treatment, under sevoflurane anesthesia, gastrocnemius muscle was excised and the deep red portion (Gr) was isolated from the superficial white (Gw) region. Expression levels of mRNA were determined by real-time PCR reaction. Nuclear protein levels were measured by western-blot procedure. Results & Discussion: mRNA levels ofTFAM in Gr were significantly greater values in the INT group than in the CNT and HYP groups (Bayes factor [BF] ≥ 10). PPARy mRNA levels showed significantly greater values in the INT group than in the CNT group in both Gr and Gw (BF ≥ 3). mRNA levels of MEF2A in Gr and Gw were markedly greater in the INT group than in the CNT and HYP groups (Cohen's d. ≥ 1.8). Nuclear NT-PGCla protein levels were substantially greater in the INT group than in the CNT group in both Gr and Gw (d ≥ 0.8). These results indicate that acute intermittent hyperoxic exposure probably improve muscle metabolic function. [ABSTRACT FROM AUTHOR]

We investigated the effect of zinc supplementation on growth and serum IGF-1 levels in 10 prepubertal Japanese children with idiopathic short statures, who had serum zinc levels of less than 80 µg/dL. Subjects were started on oral zinc supplementation at a dose of 25 mg once daily. In three children, the doses were increased by 50 mg once daily during the study period of 12 mo. The serum zinc levels rose in all subjects and reached a normal range (beyond 80 µg/dL). However, it was found that zinc supplementation did not promote growth. Although the mean IGF-1 standard deviations significantly increased, the majority did not reach the normal range. There were no significant adverse events other than mild gastrointestinal symptoms in 4 out of 10 subjects during the supplementation period. The most likely reason why growth was not promoted is that the zinc supplementation dosage was not enough to stimulate IGF-1 generation and subsequent growth velocity. [ABSTRACT FROM AUTHOR]

The first-line pharmacological treatment for patients with maturity-onset diabetes of the young type 1 (MODY1) and maturity-onset diabetes of the young type 3 (MODY3) are sulfonylureas (SUs) or insulin. However, several reports have suggested the possibility of using incretin-associated drugs, including dipeptidyl-peptidase-4 (DPP-4) inhibitors, for the treatment of patients with these types of MODY. Here we report a case of a pediatric patient with MODY1 who was successfully treated with a DPP-4 inhibitor, alogliptin. A 13-yr-old Japanese girl with diabetes was initially treated with insulin for 5 mo. After diagnosis of MODY1, confirmed via a genetic analysis, treatment was changed from insulin to alogliptin. SUs were prescribed temporarily, but monotherapy with alogliptin finally resulted in good glycemic control. After changing to alogliptin, the patient maintained optimal glycemic control with glycated hemoglobin levels of 6.3-7.0% while maintaining substantial β-cell function. No adverse events associated with alogliptin were observed. These results suggest that DPP-4 inhibitors may be a potential treatment for patients with MODY1 at the early stage of the disease when residual insulin secretion is still being sustained. [ABSTRACT FROM AUTHOR]

The article present a study that found that chromosome 6q24 methylation defects are uncommon in childhood-onset non-autoimmune diabetes mellitus patients born appropriate- or large-for-gestational age. It says that methylation defects in the imprinting locus at chromosome 6q24 result in transient neonatal diabetes and small-for-gestational age (SGA) births.

Angiogenesis, the formation of new blood vessels from a preexisting capillary network, is an essential process that improves endurance capability and also plays a critical role in embryonic development, wound healing, and cardiovascular diseases. In the 1930s, increased muscle capillarity was reported following endurance exercise training in animals. Many factors that facilitate or inhibit angiogenesis have been hitherto identified. Exercise-induced angiogenesis may involve sprouting and intussusceptive vessel growth, and has been attributed to the coordinated responses of numerous factors and stimuli. Vascular endothelial growth factor (VEGF) is thought to be an important regulator of capillary growth during exercise training. The expression of VEGF was shown to be increased in response to tissue hypoxia by hypoxiainducible transcription factor (HIF) α subunits. PGC-1 and interleukin-6 are also known to stimulate the expression of VEGF. Endurance exercise has been shown to enhance anti-angiogenic factors, such as thrombospondin-1 and endostatin. Recent findings demonstrated that miRNAs were important regulators of exerciseinduced angiogenesis. The expression of miR20b markedly declined following acute exercise and exercise training. miR20b was shown to inhibit the translation of VEGF and accumulation of HIF α. Further studies are needed to clarify whether and how miRNA, undifferentiated progenitor cells, and extracellular remodeling participate in exercise-induced capillary growth. [ABSTRACT FROM AUTHOR]

Introduction: Urethral caruncles are the most frequent benign tumors of the female urethra. Most of them are found in post-menopausal women, and they are rare in childhood. Only a few pediatric cases have been published in the literature. In this report, we present an unusual case of a pediatric patient with a urethral caruncle, along with a review of the literature. Case presentation: A 9-year-old Mongolian girl was referred to our hospital with a 2-week history of frequent adherence of a small amount of blood to her underwear. We found a sessile smooth margin, a clear boundary and an elastic, soft red tumor over the entire circumference of the urethral meatus. At the beginning, because of the child's age, urethral prolapse was suspected. There was no response after 3 weeks of conservative treatment with steroid ointment. With the patient under general anesthesia, a partial tumor resection was performed for the purpose of histological examination. The tumor excision was limited to about 1/2 laps of the urethral meatus to prevent the development of urethral stricture. On the basis of clinical and histopathological examinations, a diagnosis of a urethral caruncle was made. Post-operatively, steroid ointment application to residual masses was continued, and these disappeared about 6 months later. Our patient was free of recurrence and had had no complications after 3 years of follow-up. Conclusions: Urethral caruncles are rare in children, and the possibility of malignancy is slight during this period. Biopsy of the mass is not required for diagnosis. It should be indicated only if the mass has other characteristics that raise suspicion of malignancy. In previously reported cases, all of the tumor was removed. However, the trigger of the caruncle in childhood is chronic inflammation. Conservative therapy with steroid ointment should be the core treatment. However, it may be necessary to proceed to treatment because caruncles take a long time to heal. The case that we describe in this report will serve as an example for similar cases in the future. [ABSTRACT FROM AUTHOR]

β-cyclodextrin (β-CD) cross-linked with epichlorohydrin to form water insoluble β-cyclodextrin polymer (β-CDP) has been shown to be an effective sorbent for sorption of organic particles, but the sorption of copper (Cu2+) in aqueous solutions by β-CDP has not been conducted. The objective of this study was to explore the sorption mechanism of β-CDP for copper. The effects of different experimental conditions such as pH, ionic strength, contact time, and temperature were inspected using a batch method. In addition, binding scheme was estimated by using Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), a scanning electron microscope (SEM), and Brunauer-Emmett-Teller (BET) analysis. The adsorption of Cu2+ was observed to be higher at pH 6.0. The kinetic study revealed that the adsorption is fitted well by the pseudo-second-order kinetic model. The maximum binding of Cu2+ was estimated to be 111.11 mg/g through the Langmuir isotherm model - much higher than the existing sorption technologies. Hence, the adsorption-desorption trends of epichlorohydrin cross-linked with β-CD, along with its good recyclability, establish an alternative, effective, and novel remediation technology for the removal of Cu2+ from aqueous solutions. [ABSTRACT FROM AUTHOR]

Background: In Japan, treatment guidelines are lacking for patients with upper gastrointestinal symptoms. We aimed to compare the efficacy of different drugs for the treatment of uninvestigated upper gastrointestinal symptoms. Methods: This was a randomized, open-label, parallel-group multicenter study. Helicobacter pylori-negative, endoscopically uninvestigated patients ≥20 years of age with upper gastrointestinal symptoms of at least moderate severity (Global Overall Symptom score [GOS] ≥4 on a 7-point Likert scale) were randomized to treatment with omeprazole (10 mg once daily), famotidine (10 mg twice daily), mosapride (5 mg three times daily) or teprenone (50 mg three times daily). The primary endpoint was sufficient relief of upper gastrointestinal symptoms after 4 weeks of treatment (GOS≤2). UMIN clinical trial registration number: UMIN000005399. Results: Of 471 randomized patients, 454 were included in the full analysis set. After 4 weeks of treatment, sufficient symptom relief was achieved by 66.9% of patients in the omeprazole group, compared with 41.0%, 36.3% and 32.3% in the famotidine, mosapride and teprenone groups, respectively (all, p<0.001 vs omeprazole). There were no treatment-related adverse events. Conclusions: The favorable efficacy and safety profiles of omeprazole in relieving uninvestigated upper gastrointestinal symptoms support its use as first-line treatment in this patient group in Japan. Patients who show no improvement in symptoms despite PPI use, and those with alarm symptoms (such as vomiting, GI bleeding or acute weight loss) should receive further investigation, including prompt referral for endoscopy. Trial registration: UMIN000005399. [ABSTRACT FROM AUTHOR]

Purpose: The author previously reported that short-duration intermittent hypoxia had additive effects on improvements in endurance capacity by enhancing fatty acid metabolism. The present study was designed to investigate the effects of short-duration intermittent hypoxia on endurance capacity, metabolic enzyme activity, and protein levels associated with mitochondrial biogenesis in well-trained mice. Methods: Mice in the training group were housed in a cage with a running wheel for 7 weeks from 5 weeks old. Trained mice were then subjected to either endurance treadmill training (ET) for 60 min or hybrid training (HT, ET for 30 min followed by sprint interval exercise (5-s run-10-s rest) for 30 min) with (H-ET or H-HT) or without (ET or HT) short-duration intermittent hypoxia (4 cycles of 12-13% O2 for 15 min and 20.9% O2 for 10 min) for 4 weeks. Results and Discussion: Maximal endurance capacity was markedly greater in the H-ET and H-HT than ET and HT groups, respectively. H-ET and H-HT increased activity levels of 3-hydroxyacyl-CoAdehydrogenase in oxidative muscle portion and pyruvate dehydrogenase complex in glycolytic muscle portion. These results suggest that intermittent hypoxic exposure has beneficial effects on endurance and hybrid training to improve the endurance capacity via improving fatty acid and pyruvate oxidation in highly trained mice. [ABSTRACT FROM AUTHOR]

An optical mode converter between hybrid device and Si waveguide is the key component for efficient and stable operation of III–V/silicon-on-insulator (SOI) hybrid photonic integrated circuits (PICs). In this study, we introduced a double taper structure into such a mode converter and investigated the coupling efficiency dependence on their structural parameters. By using N2 plasma activated bonding technology, III–V/SOI double-taper-type mode couplers with various taper-tip-widths and taper lengths were fabricated, and their coupling efficiencies were evaluated. As the result, a coupling efficiency of as high as −0.2 dB was achieved for a double-taper device with a tip width of 0.4 µm and total length of 85 µm. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to (1) investigate the effects of acute hyperbaric exposure on muscle mRNA expression levels, and (2) clarify the mechanisms by which intermittent hyperbaric exposure improves endurance capacity. Exp-1: Male mice were subjected to acute 1-h hyperbaric exposure (1.3 atmospheres absolute with 20.9% O2). The expression of PGC-1α and PPARα mRNA levels significantly increased 3 h after hyperbaric exposure in hindlimb muscles. Exp-2: Mice were subjected to exercise training with (HypTr) and without (Tr) 1-h hyperbaric exposure for 4 weeks. Increases in maximal exercise capacity were significantly greater in HypTr than in Tr. In plantaris (PL), activity levels of 3-HAD and CS were significantly greater in HypTr than in Tr. CS and PFK activities both markedly increased in the white gastrocnemius muscle (Gw) in HypTr only. PGC-1α expression in the nucleus was significantly greater in HypTr than in Tr in PL, red gatrocnemius and Gw. Protein levels of Tfam and HSP 70 significantly increased after training with hyperbaric exposure. Conclusion: These results suggest that exercise training with intermittent hyperbaric exposure represents a beneficial strategy for increasing endurance performance by facilitating oxidative and glycolytic capacities and the expression of proteins involved in mitochondrial biogenesis in the hindlimb muscles. [ABSTRACT FROM AUTHOR]

An AlInAs-oxide current-confinement structure was introduced into a III–V/Si-on-insulator (SOI) hybrid laser for realizing an efficient light source composed of III–V/Si hybrid photonic integrated circuits. Lasing of the hybrid Fabry–Pérot laser was confirmed after introduction of the confinement structure providing both optical and electrical confinement. We determined the lasing characteristics of the designed hybrid laser, which showed a low threshold current and high external differential quantum efficiency comparable to that of conventional lasers fabricated on III–V compound semiconductor wafers. Comparison of the photoluminescence spectra of the III–V/SOI hybrid wafers before and after the process proved that oxidation had no influence on the active layer. The threshold current and external differential quantum efficiency of the fabricated laser with a stripe width of 4.5 µm and cavity length of 500 µm were obtained as 50 mA and 11%/facet, respectively. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine whether current cardiovascular fitness or weekly physical activity more important for lowering cardiovascular disease (CVD) risk factors regardless of ages in healthy Japanese women. Methods: 358 females participated in our study. Most of them live in Toyota City. Weekly physical activity was measured by an accelerometer attached to the subject's waist for one week. To determine cardiovascular fitness, VO2 max was estimated by the sub-maximal cycle test. Major CVD risk factors included TG, TC, HDL-c, LDL-c, Apo A-I, Apo B, systolic blood pressures, and body fat content. Results and discussion: The relationship between weekly physical activity and VO2 max were positively related with a moderate degree of significance. Our findings suggest that regular physical activity offers benefits to physically fitness. Conventional CVD risk factors, as well as their simple correlations with cardiovascular fitness and physical activity, were found. Most of the individual risk factors were more closely associated with cardiovascular fitness, than with physical activity in women after the data was age-adjusted. The evidence supported that the reduction of selected CVD risk factors are more closely linked to improved cardiovascular fitness than to physical activity in middle-aged women. [ABSTRACT FROM AUTHOR]

Purpose: The previous study showed that short-duration intermittent hypoxia causes additive effects on improving endurance capacity during chronic exercise training via enhancing fatty acid metabolism (Physiol Rep 4(7), el2744, 2016). The present study was designed to investigate the effects of short-duration intermittent hypoxia on endurance capacity in long-term trained mice. Methods: Mice of training group were housed in a cage with wheel activity device for 7 weeks from five weeks old. Thereafter trained mice were subjected to either normoxic treadmill training (Tr) or training with short-duration intermittent hypoxia (12% O2 for 15-min, room air for 10 min, 4 times, IntTr) for 4 weeks. Results and Discussion: Maximal exercise capacity was significantly greater in the IntTr group (by 36%) than in the Tr group. Total CPT activity in plantaris muscle (PL) was significantly greater in the IntTr group (by 22%) than in the Tr group. In the PL and deep red region of gastrocnemius, increases in the proportion of type IIA and 11 AX fibers, and decrease in the proportion of type IIX fiber were observed in both training groups. Whereas increase in the proportion of type I fiber was observed in the IntTr group only. These results suggest that exercise training with short-duration intermittent hypoxic exposure facilitates endurance performance via enhancing fatty acid metabolism and slow-twitch fiber composition in long-term trained mice. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to determine the effects of basal vascular tone on mechanical vasodilation of the feed arteries of rat soleus muscle. Methods: Mechanical vasodilation was measured in caged control male Wistar Hannover rats (7-72 weeks of age). Soleus muscle feed arteries were isolated and mounted on a micropipette in a sealed chamber. Arteries were pressurized to 80 mmHg. Pressure pulses of 250 mmHg were delivered for 1 s and as a series of 10 repeated 1-s pulses at 1-s intervals. Luminal diameter was measured under an inverted microscope. Results and Discussion: The mechanical vasodilation of the feed arteries of rat soleus muscle peaked at 40%-50% of the basal vascular tone. The amplitude of the mechanical dilation was significantly larger in the young rats (15.2 ± 1.86% (n = 16)) than in the mature rats (9.13 ± 1.86% (n = 16)) (p<0.05). There were no significant differences in the basal tone at rest between the young and mature rat groups. Our findings indicate that it is important to evaluate the amplitude of the mechanical vasodilation of the feed arteries of rat soleus muscle under the 40%-50% of basal vascular tone condition. These results indicate that basal tone is a crucial factor in determining the amplitude of mechanical vasodilation. [ABSTRACT FROM AUTHOR]

Purpose: Excessive of visceral fat accumulation is well known to be associated with life-style diseases such as type-2 diabetes. Intramuscular fat has been reported as a factor causing insulin resistance (IR) in obesity. Skeletal muscle attenuation (CT value) determined by computed tomography is associated with skeletal muscle fat content. This study attempted to calculate HOMA-R, an indicator of IR from the amount of skeletal muscle CT values. In addition, we examined the relationship between IR, exercise habits, and maximum oxygen uptake. Methods: The subjects were 33 healthy athletes and 29 non-athletes at our university. Skeletal muscle CT values were measured at the following points: erector spinae, psoas major, gastrocnemius, soleus, and tibialis anterior muscles. We used HOMA-R as an index of IR. Results and discussion: A high correlation was observed between VFA and HOMA-R in healthy adult males. A significant relationship was observed between HOMA-R and both V02max and VFA, but was no significant relationship between skeletal muscle CT value and either HOMA-R or VFA. However, individuals engaged in regular endurance exercise had higher muscular fat despite being markedly insulin sensitive. Higher muscular fat of long distance runner is considered that does not cause IR. [ABSTRACT FROM AUTHOR]

III–V/Si hybrid integration with direct bonding is an attractive method of realizing an electrophotonic convergence router with a small size and a low power consumption. Plasma-activated bonding (PAB) is an effective approach for reducing thermal stress during the bonding process because PAB achieves a high bonding strength with low-temperature annealing. This time, the fabrication of a GaInAsP/silicon-on-insulator (SOI) hybrid laser with Si ring-resonator-type reflectors was demonstrated by N2 PAB. By measuring the lasing spectra, we confirmed the reflective characteristics resulting from the cascaded Si ring resonators. We also investigated kink characteristics, which occur around the threshold current, of the current–light output (I–L) characteristics, and successfully approximated the kink characteristics by considering saturable absorption occurring at the III–V/Si taper tip. The taper structure was investigated in terms of a passive device as well as an active device, and a structure for eliminating saturable absorption was proposed. [ABSTRACT FROM AUTHOR]

Purpose: This study was designed to (1) investigate the effects of acute short-duration intermittent hypoxia on muscle mRNA and miroRNA expression levels, and to (2) clarify how short-duration intermittent hypoxia causes additive effects on improving endurance capacity during chronic exercise training. Methods: Exp.-l: Male ICR mice were subjected to either acute 1-h hypoxia (12% O2), acute short-duration intermittent hypoxia (12% O2 for 15-min, room air for 10 min, 4 times, Int-Hypo), or acute endurance exercise (Ex). Exp.-2: Mice were subjected to normoxic exercise training with or without hypoxic exposure for 3 weeks. Results and Discussion: PGC-la mRNA levels were significantly greater than control at 3 h post Ex and at 6 h post Int-Hypo. Expression levels of mi-23a were lower than control at 6-24 h post Int-Hypo. Training with intermittent hypoxia (IntTr) increased maximal exercise capacity greater than training alone. The HAD and total CPT activity levels were significantly enhanced after the IntTr only in deep red gastrocnemius muscle. Both PPAR5 and PGC-la mRNA levels were significantly greater in IntTr than in sedentary control. These results suggest that exercise training in normoxia with short-duration intermittent hypoxic exposure may be a beneficial strategy for increasing endurance performance via enhancing fatty acid utilization in mitochondria. [ABSTRACT FROM AUTHOR]

A pair of grating couplers with apodized structure, sandwiched by metal mirrors, was proposed for inter-layer coupling between multilayer waveguides based on hydrogenated amorphous silicon (a-Si:H). We proved theoretically that the introduction of an apodized grating coupler yields a high coupling efficiency of about 90% even for an inter-layer distance of several micrometers. In addition, this high coupling efficiency was obtained for a large bandwidth by adjusting the grating period. [ABSTRACT FROM AUTHOR]

The partial removal of the III–V layers of a III–V/silicon-on-insulator hybrid wafer was investigated to realize III–V/Si hybrid photonic integrated circuits. Using transmission electron microscopy, we found that an amorphous layer was generated at the interface of a III–V/Si wafer fabricated by N2-plasma-activated bonding. In order to remove the III–V layers including the amorphous layers without damage to the Si surface, several etching processes were carried out, and the surface conditions were evaluated by X-ray photoelectron spectroscopy. As a result, we demonstrated comparable propagation losses in Si wire waveguides with and without the bonding/removal processes. [ABSTRACT FROM AUTHOR]

Higher-order mode coupling at bending waveguides between Si multimode waveguides and 500-nm-wide wire waveguides was evaluated for low-loss Si multimode waveguide circuits. By narrowing the multimode waveguides to the wire waveguides at the bending section, the TE fundamental mode propagation was strongly maintained in the entire circuit, and the spectral fluctuation was improved from 10 dB to less than 1 dB for a 4-µm-wide waveguide. Furthermore, propagation losses were reduced to less than 1 dB/cm with waveguide widths greater than 1 µm. [ABSTRACT FROM AUTHOR]