Increasing Bending Strength of Polycarbonate Reinforced by Carbon Fiber Irradiated by Electron Beam.

In an interlayered carbon fiber-reinforced polycarbonate polymer (CFRPC) composite composed of three sized of CF plies, alternating between four PC sheets, designated [PC]4[CF]3, and a new process of activating CF cross-weave cloth plies directly on both sides with homogeneous low-energy electron beam irradiation (HLEBI) before lamination assembly and hot pressing at 6.0 MPa and 537 K for 8 min was produced. Experimental results show that a dose of 215 kGy of HLEBI raised the bending strength, σb, at each experimental accumulative probability, Pa, with the σb at a median Pa of 0.50, increasing by 25% over that of the untreated sample. Three-parameter Weibull analysis showed that when quality can be controlled, a dose of 215 kGy of HLEBI can raise the statistically lowest bending strength, σs, at Pa = 0 (94.3 Mpa), with a high correlation coefficient. This is because, although it had a higher bending strength than that in the other experimental conditions, the weakest sample of the 215 kGy data set had a much lower σb value than that of the others. Electron spin resonance (ESR) of the CF showed that naturally occurring dangling bonds in CF were increased at 215 kGy. Charge transfer to the PC occurs, apparently generating stronger bonds, which are possibly covalent, resulting in enhanced adhesion at the CF-PC interface.

A Novel Nickel-Plated Carbon Fiber Insert in Aluminum Joints with Thermoplastic ABS Polymer or Stainless Steel.

New types of hybrid aluminum joints: Al-acrylonitrile butadiene styrene (ABS) carbon fiber reinforced thermoplastic polymer (CFRTP) designated Al/Ni-CFP/ABS, and Al-18-8 Stainless steel, Al/Ni-CFP/18-8, by Ni-plated carbon fiber plug (Ni-CFP) insert not before seen in the literature have been fabricated. The goal is to take advantage of extremely high ~6 mm CF surface area for high adhesion, to enhance the safety level of aircraft and other parts. This is without fasteners, chemical treatment, or glue. First, the CFP is plated with Ni. Second, the higher melting point half-length is spot welded to the CFP; and third, the remaining half-length is fabricated. The ultimate tensile strength (UTS) of Al/Ni-CFP/ABS was raised 15 times over that of Al/ABS. Normalized cUTS according to CFP cross-section by Rule of Mixtures for cAl/Ni-CFP/18-8 was raised over that of cAl/Ni-CFP/18-8 from 140 to 360 MPa. Resistance energy to tensile deformation, UT, was raised 12 times from Al/ABS to Al/Ni-CFP/ABS, and 6 times from Al/CFP/18-8 to Al/Ni-CFP/18-8. Spot welding allows rapid melting followed by rapid solidification for amorphous metal structures minimizing grain boundaries. The Ni-coating lowers or counters the effects of brittle Al4C3 and FexC formation at the interface and prevents damage by impingement to CFs, allowing joints to take on more of the load.

Reduced level of physical activity in Japanese patients with chronic obstructive pulmonary disease.

BACKGROUND: There is increasing interest in the quantification of physical activity (PA) with an accelerometer for the management of chronic obstructive pulmonary disease (COPD). However, a detailed understanding of the PA in Japanese patients with COPD is lacking. We evaluated the levels of PA in terms of intensity in Japanese patients with COPD and evaluated the factors, which could influence the PA. METHODS: Forty-three outpatients with COPD and 21 age-matched healthy subjects were monitored with a triaxial accelerometer, and their PA was compared. Furthermore, the effects of pulmonary function, ADO index (age, dyspnea, and airflow obstruction) and modified BODE index (body mass index, airflow obstruction, dyspnea, and exercise capacity) on the PA were evaluated. RESULTS: The PA in COPD was significantly reduced at all intensities. The reduced levels of PA in COPD were 23.1% at ≥2.0 metabolic equivalents (METs), 33.0% at ≥2.5 METs, 50.9% at ≥3.0 METs, and 66.9% at ≥3.5 METs, compared with that of healthy subjects, and the reduction was significant at GOLD stage III. The values of FVC, FEV1.0, and DLCO/VA were correlated with that of the PA, but the lung volume parameters were not. The ADO and modified BODE indices were also well correlated with the PA. CONCLUSIONS: The reduced levels of PA in Japanese patients with COPD were objectively demonstrated in terms of intensity that could provide us a new target for the management of COPD.

Validation of the triaxial accelerometer for the evaluation of physical activity in Japanese patients with COPD.

OBJECTIVE: The quantification of physical activity is useful for the management of chronic obstructive pulmonary disease (COPD) but has not been fully established yet. The DynaPort Activity Monitor(®) (DAM), a triaxial accelerometer is the only well validated accelerometer in Caucasians but it has not been validated in Japanese COPD patients. We initially evaluated the reproducibility of the DAM in Japanese healthy subjects. Next, the within-subject repeatability and the determinants of physical activity were investigated in Japanese COPD patients. MATERIALS AND METHODS: The durations of locomotion, standing, and sitting measured by the DAM were compared to those of the self-records (Study 1). COPD patients wore the DAM for 3 days and the durations of each activity of 2 selected days were compared to assess the repeatability (Study 2). The relationship between the duration of locomotion and the physiological properties were examined (Study 3). RESULTS: The activities measured by the DAM were significantly associated with those of the self-records (p<0.001). The values of the intra-class correlation coefficient (ICC) for the reproducibility were over 0.99, and the agreement with the self-records was observed for the DAM. Similarly, the values of ICC for repeatability were over 0.84 in all activities, and there was no systematic bias in the COPD patients. The duration of locomotion was negatively correlated with the total lung capacity (TLC) and closing capacity/TLC, but not with other pulmonary functions, exercise capacity, muscle force, dyspnea, or modified BODE index. CONCLUSION: The triaxial accelerometer is reliable for evaluating the physical activity of Japanese COPD patients.

Validation of a compact motion sensor for the measurement of physical activity in patients with chronic obstructive pulmonary disease.

BACKGROUND: The DynaPort Activity Monitor (DAM) has been reported to be useful to evaluate the activity in healthy subjects and patients with chronic obstructive pulmonary disease (COPD). However, it is difficult to estimate the activity of COPD patients using DAM, because its battery works only for several hours and sensors should be worn at two parts of the body. A newly developed compact, single-position triaxial accelerometer (Actimarker) can measure the activity for >1 month, but has not been validated for COPD patients. OBJECTIVES: The validity of the Actimarker was evaluated in COPD patients. METHODS: In study 1, the validity of the device was tested in 14 stable COPD patients by comparing it with DAM. In study 2, the influence of the weather on activity was examined. In study 3, the number of measurement days required to ensure repeatability was determined. RESULTS: The durations of activity measured by the Actimarker and DAM were significantly correlated at intensity values ≥2.0, ≥2.5 and ≥3.0 METs. The duration of activity on rainy days was significantly shorter than that on non-rainy days. The values of intraclass correlation coefficients were >0.8 in 3-, 4- or 5-day measurements, and there was no systematic bias at any number of days or intensities with Bland-Altman plots. CONCLUSIONS: The validity of the Actimarker was confirmed, and repeatability was obtained when the data from at least 3 non-rainy weekdays were analyzed. Actimarker appears to be useful as a simplified method to evaluate the physical activity of COPD patients.

Increase of nitrosative stress in patients with eosinophilic pneumonia.

BACKGROUND: Exhaled nitric oxide (NO) production is increased in asthma and reflects the degree of airway inflammation. The alveolar NO concentration (Calv) in interstitial pneumonia is reported to be increased. However, it remains unknown whether NO production is increased and nitrosative stress occurs in eosinophilic pneumonia (EP). We hypothesized that nitrosative stress markers including Calv, inducible type of NO synthase (iNOS), and 3-nitrotyrosine (3-NT), are upregulated in EP. METHODS: Exhaled NO including fractional exhaled NO (FENO) and Calv was measured in ten healthy subjects, 13 patients with idiopathic pulmonary fibrosis (IPF), and 13 patients with EP. iNOS expression and 3-NT formation were assessed by immunocytochemistory in BALf cells. The exhaled NO, lung function, and systemic inflammatory markers of the EP patients were investigated after corticosteroid treatment for 4 weeks. RESULTS: The Calv levels in the EP group (14.4 ± 2.0 ppb) were significantly higher than those in the healthy subjects (5.1 ± 0.6 ppb, p < 0.01) and the IPF groups (6.3 ± 0.6 ppb, p < 0.01) as well as the FENO and the corrected Calv levels (all p < 0.01). More iNOS and 3-NT positive cells were observed in the EP group compared to the healthy subject and IPF patient. The Calv levels had significant positive correlations with both iNOS (r = 0.858, p < 0.05) and 3-NT positive cells (r = 0.924, p < 0.01). Corticosteroid treatment significantly reduced both the FENO (p < 0.05) and the Calv levels (p < 0.01). The magnitude of reduction in the Calv levels had a significant positive correlation with the peripheral blood eosinophil counts (r = 0.802, p < 0.05). CONCLUSIONS: These results suggested that excessive nitrosative stress occurred in EP and that Calv could be a marker of the disease activity.

High COPD prevalence in patients with liver disease.

OBJECTIVE: Comorbidities of chronic obstructive pulmonary disease (COPD) have been recognized as an important issue in COPD management. We have reported that patients with liver diseases show a higher prevalence of COPD, but the number of patients with liver diseases was small and the details of liver diseases were not clearly investigated. In this study, we investigated the prevalence of COPD in patients with liver diseases by recruiting a large number of patients, and also investigated was the effect of hepatitis virus infection on COPD prevalence. PATIENTS AND METHODS: Six hundred sixty-six patients were recruited from 9 primary care clinics and three hospitals. All of these patients were aged 40 years or older with chronic diseases and had not been diagnosed as having respiratory diseases. A spirometry was performed without administration of an inhaled bronchodilator. Airflow limitation was defined as FEV1/FVC<70%. Underlying diseases were diagnosed by doctors of the clinics or the hospitals. RESULTS: Two hundred fifty-six patients had liver diseases, and 410 did not. Of 410 patients without liver diseases, 37 patients (9.0%) were diagnosed as COPD, and of 256 patients with liver diseases, 35 patients (13.8%) were COPD. When the prevalence was analyzed according to smoking, age and gender, liver diseases showed a significantly high odds ratio (2.10, 95%CI 1.23-3.57, p=0.006), but hepatitis virus infection showed a non-significant tendency toward a high odds ratio. CONCLUSION: The patients with liver diseases had a significantly high prevalence of COPD. The presence of liver disease might become a useful predictor for the early detection of COPD.

Oxidative stress augments toll-like receptor 8 mediated neutrophilic responses in healthy subjects.

BACKGROUND: Excessive oxidative stress has been reported to be generated in inflamed tissues and contribute to the pathogenesis of inflammatory lung diseases, exacerbations of which induced by viral infections are associated with toll-like receptor (TLR) activation. Among these receptors, TLR8 has been reported as a key receptor that recognizes single-strand RNA virus. However, it remains unknown whether TLR8 signaling is potentiated by oxidative stress. The aim of this study is to examine whether oxidative stress modulates TLR8 signaling in vitro. METHODS: Human peripheral blood neutrophils were obtained from healthy non-smokers and stimulated with TLR 7/8 agonist imidazoquinoline resiquimod (R848) in the presence or absence of hydrogen peroxide (H2O2). Neutrophilic responses including cytokine release, superoxide production and chemotaxis were examined, and the signal transduction was also analyzed. RESULTS: Activation of TLR8, but not TLR7, augmented IL-8 release. The R848-augmented IL-8 release was significantly potentiated by pretreatment with H2O2 (p < 0.01), and N-acetyl-L-cysteine reversed this potentiation. The combination of H2O2 and R848 significantly potentiated NF-kB phosphorylation and IkBalpha degradation. The H2O2-potentiated IL-8 release was suppressed by MG-132, a proteosome inhibitor, and by dexamethasone. The expressions of TLR8, myeloid differentiation primary response gene 88 (MyD88), and tumor necrosis factor receptor-associated factor 6 (TRAF6) were not affected by H2O2. CONCLUSION: TLR8-mediated neutrophilic responses were markedly potentiated by oxidative stress, and the potentiation was mediated by enhanced NF-kB activation. These results suggest that oxidative stress might potentiate the neutrophilic inflammation during viral infection.

Peroxynitrite augments fibroblast-mediated tissue remodeling via myofibroblast differentiation.

Irreversible airflow limitation in asthma is associated with airway remodeling in which the differentiation of fibroblasts to myofibroblasts plays a pivotal role. In asthmatic airways, excessive production of reactive nitrogen species (RNS) has been observed. The aim of this study is to evaluate whether peroxynitrite, one of the RNS, can affect the differentiation of fibroblasts to myofibroblasts. Human fetal lung fibroblasts were treated with various concentrations of authentic peroxynitrite or a peroxynitrite donor 3-morpholinosydnonimine hydrochloride (SIN-1), and the expressions of alpha-smooth muscle actin (alpha-SMA) and desmin, markers of myofibroblast differentiation, were evaluated. The releases of transforming growth factor-beta(1) (TGF-beta(1)) and ECM proteins including fibronectin and collagen I were assessed. To clarify the mechanism in this differentiation, the effect of anti-TGF-beta antibody or NF-kappaB inhibitors on the alpha-SMA expression and ECM production was assessed. Peroxynitrite and SIN-1 significantly augmented the alpha-SMA expression compared with control in a concentration-dependent manner (P < 0.01 and P < 0.05, respectively). Peroxynitrite significantly increased desmin and TGF-beta(1) production (P < 0.01). Peroxynitrite enhanced the translocation of NF-kappaB into the nucleus confirmed by immunocytostaining and immunoblotting. Peroxynitrite-augmented alpha-SMA expression was blocked by NF-kappaB inhibitors, MG132 and caffeic acid phenethyl ester (CAPE), and anti-TGF-beta antibody. CAPE completely inhibited the peroxynitrite-augmented TGF-beta(1) release. The production of fibronectin and collagen I was significantly increased by peroxynitrite (P < 0.01) and inhibited by anti-TGF-beta antibody. These results suggest that RNS can affect the differentiation to myofibroblasts and excessive ECM production via a NF-kappaB-TGF-beta(1)-dependent pathway.

Peak expiratory flow variability adjusted by forced expiratory volume in one second is a good index for airway responsiveness in asthmatics.

BACKGROUND: The lowest peak expiratory flow (PEF) over a week, expressed as a percentage of the highest PEF (Min%Max PEF) has been reported to be the index that most closely correlates with airway hyperresponsiveness (AHR) in asthmatics. However, both fluctuation of the airway caliber and airflow limitation are regarded as physiological properties of asthma closely related to AHR. An accurate index that shows the degree of AHR may be obtained by combining the index of airway lability with the parameters that represent airway caliber. METHODS: Ninety-two steroid-naive and twenty-eight steroid-treated asthmatic patients were enrolled. Using the physiological parameters obtained from spirometry and PEF monitoring, we investigated the indices which correlate accurately with airway responsiveness measured by the inhalation challenge test. RESULTS: Although the methacholine threshold was related to all parameters that represent airway caliber and lability, Min%Max PEF had the strongest correlation with AHR. When Min%Max PEF was adjusted by the airway geometric factors, the normalization of Min%Max PEF with forced expiratory volume in one second as a percentage of the predicted value (%FEV(1)) improved the relationship between Min%Max PEF and AHR. CONCLUSIONS: Min%Max PEF adjusted by %FEV(1) showed a good correlation with airway responsiveness measured by the inhalation challenge test, and may be useful as a convenient alternative index of AHR in asthmatic patients.