Structural origin of thermal shrinkage in soda-lime silicate glass below the glass transition temperature: A theoretical investigation by microsecond timescale molecular dynamics simulations.

Microscopic dynamical features in the relaxation of glass structures are one of the most important unsolved problems in condensed matter physics. Although the structural relaxation processes in the vicinity of glass transition temperature are phenomenologically expressed by the Kohlrausch-Williams-Watts function and the relaxation time can be successfully interpreted by Adam-Gibbs theory and/or Narayanaswamy's model, the atomic rearrangement, which is the origin of the volume change, and its driving force have not been elucidated. Using the microsecond time-scale molecular dynamics simulations, this study provides insights to quantitatively determine the origin of the thermal shrinkage below Tg in a soda-lime silicate glass. We found that during annealing below Tg, Na ions penetrate into the six-membered silicate rings, which remedies the acute O-O-O angles of the energetically unstable rings. The ring structure change makes the space to possess the cation inside the rings, but the ring volume is eventually reduced, which results in thermal shrinkage of the soda-lime silica glass. In conclusion, the dynamical structural relaxation due to the cation displacement evokes the overall volume relaxation at low temperature in the glassy material.

Potential asbestos exposure among patients with primary lung cancer in Japan.

OBJECTIVE: To investigate the extent of asbestos exposure among patients with primary lung cancer in Japan. METHODS: A retrospective estimation of potential asbestos-exposed individuals, as determined by the presence of pleural plaques identified on chest computed tomography (CT), was conducted on 885 pathologically confirmed primary lung cancer patients (mean age 71.3 years, 641 males). All patients were diagnosed at 29 hospitals across Japan between 2006 and 2007. Since these hospitals belong to the Japan Federation of Democratic Medical Institutions (MIN-IREN), an organization of medical institutions for workers, the study subjects may contain a higher proportion of workers than the general population. RESULTS: Pleural plaques were identified in 12.8% of subjects (15.8% in males and 4.9% in females), consisting exclusively of cases older than 50 years. They were found most frequently on the chest wall pleura (96.5%), followed by the diaphragm (23.9%) and mediastinum (9.7%). Calcifications were seen in 47 cases (41.6%). The highest prevalence of pleural plaques was seen among workers from construction-related fields (37.7%). No distinct lung cancer histology was observed in patients with pleural plaques. Coexistence of pleural plaques and small irregular opacities was observed in 2.5% of subjects. CONCLUSION: In a Japanese population representing more workers than general Japanese, 12.8% of patients with primary lung cancer may have experienced asbestos exposure at some time in the past. Special medical attention should be paid to individuals with a history of employment in construction-related occupations, as workers in this sector showed the highest prevalence of pleural plaques.

Safety and efficacy of high-dose leukocytapheresis in patients with refractory asthma.

OBJECTIVE AND DESIGN: An open-label, non-randomized, single-arm study was performed to investigate the safety and efficacy of high-dose leukocytapheresis (pulse LCAP) for refractory asthma. SUBJECTS: Six patients who fulfilled the ATS workshop criteria for refractory asthma were enrolled and completed this clinical study. TREATMENT: After 4 weeks of observation, pulse LCAP using a large LCAP filter, Cellsorba(®) CS-180S, was performed twice with a 1-week interval at a target dose of 5 L per treatment session. METHODS: The clinical response was assessed by monitoring the peak expiratory flow rate (PEFR) twice a day. The asthma control test (ACT) was used to evaluate the condition of asthma symptoms. The fraction of exhaled nitric oxide (FeNO) as a biomarker for eosinophilic airway inflammation was measured using a chemiluminescence analyzer. RESULTS: PEFR in the morning or the evening and the sum total of the score on the ACT were increased after two consecutive sessions of pulse LCAP. FeNO decreased after pulse LCAP. CONCLUSIONS: The results suggest the efficacy of pulse LCAP for refractory asthma.