Silicon nanotubes (SiNTs) have been grown on a porous alumina surface, without the assistance of catalysts, by molecular beam epitaxy (MBE). The flow rate of Si atoms and the corrugated porous alumina surface seem to play an important role in the continuous growth of Si tubular structures. The Figure shows a field‐emission scanning electron microscopy image of the SiNTs grown on a regular array of hexagonal porous alumina.
PurposeHand grip strength (HGS) is a simple way of predicting the risk of cardiovascular disease and all-cause mortality in the general population. However, the practical significance of grip strength in patients with COPD is uncertain. The aim of this study was to compare HGS between subjects with and without COPD and to evaluate its clinical relevance in patients with COPD by using a national survey.MethodsData were collected from the Korean National Health and Nutrition Examination Survey. The study included 421 adults with COPD and 2,542 controls who completed questionnaires, spirometry, and a HGS test. HGS was compared between subjects with and without COPD, and the association between grip strength, lung function, and quality of life (QoL) was evaluated.ResultsThe mean HGS was 33.3±9.1 kg in the COPD group and 29.9±9.5 kg in the non-COPD group; adjusted HGS was 30.9±0.33 kg and 30.9±0.11 kg, respectively (P=0.99). HGS was not related to forced vital capacity (β=0.04, P=0.70) or forced expiratory volume in 1 second (β=0.11, P=0.24) in multivariable analysis. HGS was independently associated with the EQ-5D index, but the relationship was stronger in the COPD group (β=0.30, P<0.001) than in the non-COPD group (β=0.21, P<0.001). The results were similar for each component of the EQ-5D, including mobility (β=−0.25, P<0.001), daily activity (β=−0.19, P=0.01), pain/discomfort (β=−0.32, P<0.001), and anxiety/depression (β=−0.16, P=0.01).ConclusionHGS was not different between subjects with and without COPD, but was associated with QoL – including mobility, daily activity, pain/discomfort, and anxiety/depression – in patients with COPD. The HGS test could be used as a marker of QoL in patients with COPD and could assist risk stratification in clinical practice.
Background: Outcomes of antibiotic treatment for lung disease caused by nontuberculous mycobacteria (NTM) are unsatisfactory. The role of adjunctive surgery in the treatment of NTM lung disease is still unclear. Methods: We conducted a retrospective review of 70 patients who underwent pulmonary resection for NTM lung disease from March 2007 to February 2013. All patients received recommended antibiotic treatment before and after the surgery. Results: A total of 70 patients underwent 74 operations. The median age of the patients was 50 years. Of the 70 patients, 45 (64%) had Mycobacterium avium complex infection (24 M. intracellulare and 21 M. avium) and 23 (33%) had M. abscessus complex infection (15 M. abscessus and 8 M. massiliense). Thirty-eight (54%) patients had the nodular bronchiectatic form and 28 (40%) had the fibrocavitary form of NTM lung disease. The indications for surgery were a poor response to drug therapy (n=52), remnant cavitary lesions and severe bronchiectasis (n=14), and hemoptysis (n=4). Preoperative sputum acid-fast bacilli staining results were positive in 44 (63%) patients, and sputum culture was positive in 54 (76%). The surgery included lobectomy or lobectomy plus segmentectomy (n=50, 68%), segmentectomy (n=11, 15%), pneumonectomy or completion pneumonectomy (n=8, 11%), bilobectomy or bilobectomy plus segmentectomy (n=4, 5%), and wedge resection (n=1, 1%). Postoperative complications occurred in 15 (21%) patients, including one postoperative death and bronchopleural fistula in 5 patients with the fibrocavitary form of the disease. A negative sputum culture was achieved and maintained in 57 (81%) patients.
This paper aims to measure the relative efficiency of liner shipping companies in terms of operational and financial performance and further investigates the impact of strategic and operational management on efficiency performance. A two-stage Data Envelopment Analysis (DEA) approach is employed combining DEA and Tobit regression, which has been extensively used in various research areas. 14 liner shipping companies from the top 20 container lines in terms of fleet capacity were included in this analysis. The results suggest that the firm size (in terms of TEU capacity), ship size, the ratio of chartered vessels, use of new vessels, and the formation of alliances all make a positive contribution to the financial performance of liner shipping companies. Ship age and ship type did not show a significant contribution to the financial performance and, for the operational performance, any of these determinant factors were not significant. This analysis is able to provide container shipping companies with information on the managerial and strategic implications of how managerial options influence operational and financial performance. In addition, maritime researchers will benefit from this study, measuring the efficiency of container shipping companies and the factors that influence efficiency, as this study is the first to investigate and model factors of relative efficiency of container shipping companies to the authors' knowledge.
BackgroundChronic obstructive pulmonary disease (COPD), is a chronic inflammatory disorder. We evaluated whether white blood cell (WBC) count, is associated with the severity of COPD, independent of other inflammatory conditions, such as metabolic syndrome.MethodsThe WBC counts were compared between 1227 COPD patients and 8679 non-COPD adults older than 40. The relationships between the WBC count, lung function, and symptoms score in COPD patients, were determined, using general linear regression analyses.ResultsThe WBC count was negatively associated with forced vital capacity (FVC, L), FVC (% predicted), forced expiry volume in one second (FEV1, L), and FEV1 (% predicted) in COPD patients. Additionally, the WBC count was independently associated with the quality of life measure, by EQ5D-index score. However, this relationship between WBC count, and disease severity, was not significant in current smokers, because of the confounding effect of smoking, on the WBC count.ConclusionThe WBC count is associated with current smoking status and COPD severity, and a risk factor for poor lung function, and quality of life, especially in non-currently smoking COPD patients. The WBC count can be used, as an easily measurable COPD biomarker.
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