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Objective: To observe oxygen uptake efficiency plateau (OUEP, i.e.highest V˙O2/V˙E) and carbon dioxide output efficiency (lowest V˙E/V˙CO2) parameter changes during exercise in normal subjects., Methods: Five healthy volunteers performed the symptom limited maximal cardiopulmonary exercise test (CPET) at Harbor-UCLA Medical Center. V˙O2/V˙E and V˙E/V˙CO2 were determined by both arterial and central venous catheters. After blood gas analysis of arterial and venous sampling at the last 30 seconds of every exercise stage and every minute of incremental loading, the continuous parameter changes of hemodynamics, pulmonary ventilation were monitored and oxygen uptake ventilatory efficiency (V˙O2/V˙E and V˙E/V˙CO2) was calculated., Results: During CPET, as the loading gradually increased, cardiac output, heart rate, mixed venous oxygen saturation, arteriovenous oxygen difference, minute ventilation, minute alveolar ventilation, tidal volume, alveolar ventilation and pulmonary ventilation perfusion ratio increased near-linearly (P < 0.05-0.01, vs.resting); arterial oxygen concentration maintained at a high level without significant change (P > 0.05); stroke volume, respiratory rate, arterial partial pressure of carbon dioxide, arterial blood hydrogen ion concentration and dead space ventilation ratio significantly changed none-linearly (compare resting state P < 0.05-0.01).OUE during exercise increased from 30.9 ± 3.3 at resting state to the highest plateau 46.0 ± 4.7 (P < 0.05 vs.resting state), then, declined gradually after anaerobic threshold (P < 0.05-0.01, vs.OUEP) and reached 36.6 ± 4.4 at peak exercise. The V˙E/V˙CO2 during exercise decreased from the resting state (39.2 ± 6.5) to the minimum value (24.2 ± 2.4) after AT for a few minutes (P > 0.05 vs.earlier stage), then gradually increased after the ventilatory compensation point (P < 0.05 vs.earlier stage) and reached to 25.9 ± 2.7 at peak exercise., Conclusions: Cardiac and lung function as well as metabolism change during CPET is synchronous.In the absence of pulmonary limit, appearing before and after anaerobic threshold, OUEP and lowest V˙E/V˙CO2 could be used as reliable parameters representing the circulatory function.

Objective: To investigate the imaging features of burst injury of the lung in coal miners and to provide reference for clinical diagnosis and treatment., Methods: A retrospective analysis was performed on the clinical data and imaging findings of 78 patients with burst injury of the lung., Results: The imaging findings of burst injury of the lung were variable and complex, and they varied over time. Eleven cases showed no abnormalities on X-ray and CT within 24 h, but abnormalities appeared within 3 d; 53 cases showed abnormalities on X-ray and CT and had an exacerbation within 3 d; 8 cases showed improvements when reexamined. Among the 78 patients examined by X-ray and (or) CT, ground glass-like shadows were noted in 15 cases, interstitial changes in 13 cases, segmental consolidation in 24 cases, and diffuse consolidation in 26 cases. The complications included pneumothorax (n = 35), hemothorax (n = 28), costal fracture (n = 24), and pulmonary infection (n = 27)., Conclusion: X-ray plain film and CT offer a reliable basis for early diagnosis of burst injury of the lung. CT is superior to X-ray plain film in detecting lesions, so chest CT should be performed as early as possible to remedy burst injury of the lung.

Objective: To investigate the chemical constituents of Hypericum petiolulatum., Method: The chemical constituents were isolated and purified by column chromatography on silica gel, macroporous adsorbent resin, Sephadex LH-20, and preparative HPLC. Structures of the compounds were identified by NMR and MS spectroscopic methods., Result: Nine lignans were obtained and their structures were elucidated as (-)-(2R, 3R)-1-O-feruloyl-8,8'-bisdihydrosiringenin (1), (-) -secoisolariciresinol 4-O-beta-D-glucopyrano-side (2), isolariciresinol-beta-4'-O-beta-D-glucopyranoside (3), 5-methoxy-9beta-xylopyra-nosyl-(+) -isolariciresinol (4), (+) -lyoniresinol 2alpha-O-beta-D-xylopyranoside (5), 5-methoxy-9-beta-xylopyranosyl-(-) -isolariciresinol (6), isolariciresinol 6a-O-beta-D-gluco-side (7), (+)-lyoniresinol 3alpha-O-beta-D-xylopyranoside (8) and 7-methoxy-5-benzofuranpropanol 4'-O-beta-D-glucopyranoside (9)., Conclusion: Coupound 1 was new and compounds 2-9 were obtained from the genus Hypericum for the first time.