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This paper presents the results of the numerical finite-difference time-domain analysis of a strongly localized antisymmetric plasmon, coupled across a nanogap between two identical metal wedges. Dispersion, dissipation, field structure, and existence conditions of such coupled wedge plasmons are determined and investigated on an example of the fundamental coupled mode. It is shown that in the general case there exist three critical wedge angles and a critical gap width (separation between the wedge tips). If the gap width is larger than the critical separation, then the antisymmetric wedge plasmons can exist only in the ranges between the first and the second critical angles, and between the third critical angle and 180 degrees. If the gap width is smaller or equal to the critical separation, then the third and the second critical angles merge, leaving only one interval of wedge angles within which the antisymmetric coupled wedge plasmons can exist. The effect of rounded edge tips is also investigated and is shown to be similar to that of different wedge angles. Feasibility of using these plasmons for the design of efficient subwavelength waveguides is discussed.

Minako Sato,1 Shotaro Chubachi,1 Mamoru Sasaki,1 Mizuha Haraguchi,1 Naofumi Kameyama,1 Akihiro Tsutsumi,1 Saeko Takahashi,1 Hidetoshi Nakamura,1,2 Koichiro Asano,3 Tomoko Betsuyaku1 1Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, 2Department of Respiratory Medicine, Saitama Medical University, Saitama, 3Division of Pulmonary Medicine, Department of Medicine, Tokai University School of Medicine, Kanagawa, Japan Background: Patients with COPD might not report mild exacerbation. The frequency, risk factors, and impact of mild exacerbation on COPD status are unknown. Objectives: The present study was performed to compare features between mild exacerbation and moderate or severe exacerbation in Japanese patients with COPD. Patients and methods: An observational COPD cohort was designed at Keio University and affiliated hospitals to prospectively investigate the management of COPD comorbidities. This study analyzes data only from patients with COPD who had completed annual examinations and questionnaires over a period of 2 years (n=311). Results: Among 59 patients with mild exacerbations during the first year, 32.2% also experienced only mild exacerbations in the second year. Among 60 patients with moderate or severe exacerbations during the first year, 40% also had the same severity of exacerbation during the second year. Findings of the COPD assessment test and the symptom component of the St George’s Respiratory Questionnaire at steady state were worse in patients with mild exacerbations than in those who were exacerbation free during the 2-year study period, although the severity of the ratio of predicted forced expiratory volume in 1 second did not differ between them. Severe airflow limitation (the ratio of predicted forced expiratory volume in 1 second

Masaki Miyazaki,1 Hidetoshi Nakamura,1,2 Saeko Takahashi,1 Shotaro Chubachi,1 Mamoru Sasaki,1 Mizuha Haraguchi,1 Hideki Terai,1 Makoto Ishii,1 Koichi Fukunaga,1 Sadatomo Tasaka,1 Kenzo Soejima,1 Koichiro Asano,3 Tomoko Betsuyaku1 On behalf of the Keio COPD Comorbidity Research (K-CCR) group 1Division of Pulmonary Medicine, Department of Medicine, Keio University School of Medicine, Tokyo, 2Department of Respiratory Medicine, Saitama Medical University, Saitama, 3Division of Pulmonary Medicine, Department of Medicine, Tokai University School of Medicine, Kanagawa, Japan Background: Triple combination therapy involving long-acting muscarinic antagonists long-acting β2 agonists, and inhaled corticosteroids has recently become an option for maintenance treatment of COPD. Some add-on clinical trials have reported the benefits of these combinations. However, the process to step up to triple therapy varies for individual cases.Methods: Keio University and affiliated hospitals conducted an observational COPD cohort study, recruiting patients diagnosed as having COPD by pulmonary physicians and those referred for investigation of possible COPD. Their prescription history and clinical course were retrospectively analyzed based on the physicians’ medical records and patient questionnaires. This study was registered with UMIN (UMIN000003470, April 10, 2010).Results: A total of 95 of the 445 COPD patients (21%) were treated with inhaled corticosteroids/long-acting β2 agonists/long-acting muscarinic antagonists as maintenance therapy, including 12 in COPD Grade I, 31 in Grade II, 38 in Grade III, and 14 in Grade IV, based on the Global Initiative for Chronic Obstructive Lung Disease spirometric grading. For more than half of the patients on triple therapy, the treatment had been intensified due to unsatisfactory improvement of symptoms, and 32% were treated with triple therapy due to comorbid asthma. In contrast, there were COPD patients whose therapy was maintained after starting with triple therapy because of their serious conditions or concurrent exacerbation at diagnosis (8%).Conclusion: Triple therapy was often prescribed in the real-life management of COPD, even in patients whose airflow limitation was not severe. To better control symptoms was the major reason for choosing triple therapy, regardless of the severity of COPD, in Japan. Keywords: chronic obstructive pulmonary disease, inhaled corticosteroids, long-acting muscarinic antagonists, long-acting β2 agonists, triple therapy

We propose a new type of photothermal spectroscopic technique. The experimental setup is simple and the experiment can be readily carried out, even in the difficult environments that are often required for optical and surface studies of materials. Features of the method proposed here are nondestructive and noncontact; in addition, the simplicity of our design enables us easily to make the system resistant to vibration and drift, which leads to a high signal-to-noise ratio of the photothermal signal. A few experiments have been conducted to demonstrate the utilization of the method, e.g., a quantum-radiative efficiency of surface polaritons in an air-Ag film-BK-7 prism geometry has been evaluated.