Hiroshi Kaneshima

Distribution coefficient of Mg2+ ions between calcite and solution at 10–50°C

The distribution coefficient (λMg) of Mg2+ ions between calcite and solution was found to be 0.012 ± 0.001 (10°C), 0.014 ± 0.001 (15°C), 0.019 ± 0.001 (25°C), 0.024 ± 0.001 (30°C), 0.027 ± 0.001 (35°C) and 0.040 + 0.003 (50°C). This indicates a remarkable dependence on temperature. The effect of the Mg2+/Ca2+ molar ratio in a parent solution on λMg for calcite is small, where the molar ratio lies in the range 0.04-2. However, the λMg value for aragonite tends to decrease with increasing Mg2+/Ca2+ ratio in the parent solution. The largest Mg content of calcite in the Ca(HCO3)2-Mg2+ → calcite system is around 2 mol% in the temperature range 10–50°C. Neither homogeneous nor heterogeneous distribution laws hold for aragonite precipitation, and the temperature effect on the coprecipitation of Mg2+ ions with aragonite is very small.

The prevalence of airway obstruction among Japanese HIV-positive male patients compared with general population; a case-control study of single center analysis.

BACKGROUND AND OBJECTIVE Previous studies have suggested that human immunodeficiency virus (HIV) infection and/or the airway colonization of Pneumocystis jirovecii (Pcj) impact on the progression of airway obstruction, such as chronic obstructive pulmonary disease (COPD). This study was aimed to evaluate the relationship between HIV infection, airway colonization of Pcj and airway obstruction in Japanese male patients. METHODS Case-control study of 49 HIV-positive and 257 HIV-negative men were enrolled in this study. Airway obstruction was determined by spirometry. Cigarette smoking was determined by a self report. Laboratory data were obtained from medical records. Among HIV positive patients, the airway colonization of Pcj was evaluated by induced sputum using the real time polymerase chain reaction method. RESULTS Forty-eight out of 49 (97.9%) HIV-positive patients received antiretroviral therapy, and their median CD4 cell counts were 491/μL (79-935). The prevalence of airway obstruction as determined by spirometry was 10.2% (5/49) in HIV-positive subjects and 2.4% (5/208) in HIV-negative subjects (p = 0.024). Compared with the control group, HIV-positive patients were significantly younger (median age 44 vs 40, p = 0.019). After adjusting for age, pack-years of smoking, HIV infection was an independent risk factor for airway obstruction (OR; 10.93, 95%CI 1.99-60.1, p = 0.006). None of patient was detected the airway colonization of Pcj. CONCLUSIONS HIV infection was an independent risk factor for airway obstruction regardless of airway colonization of Pcj. Health-care providers should be aware of the increased likelihood of airway obstruction among HIV-positive patients.