Remote visualization of underwater oil using a flash Raman lidar system.

We propose and experimentally demonstrate a new, to the best of our knowledge, underwater monitoring system that incorporates Raman spectroscopy based on a flash lidar. We have visualized underwater oil at a 5 m distance by illuminating the area of around 15 cm diameter with an expanding laser beam at 532 nm and detecting the oil and water Raman images. By calibrating the oil Raman image with the water Raman image, the detection limit of liquid oil thickness has been estimated to be about 0.27 mm. Thus, the proposed technique provides the capability of effectively detecting oil leaks in underwater sea areas.

Field-of-view dependence of lidar signals by use of Newtonian and Cassegrainian telescopes.

The dependence of lidar return signals on the aperture size of the field stop is examined. Observational results are presented for both Newtonian and Cassegrainian telescopes. Analytic expressions are derived for the lidar geometric form factors, in satisfactory agreement with the experiments.

[A patient with myotonic dystrophy who presented with chest roentgenographic abnormalities and alveolar hypoventilation].

A 52-year-old man had been asymptomatic except for nasal speech since his third decade of life. A chest roentgenogram obtained during a health screening one year before admission revealed elevation of the right hemidiaphragm and infiltrates in the right lower lung field. Because the pulmonary shadows had gradually increased, he was admitted to the hospital, for further examination. Based on physiological findings and on the results of electromyography, myotonic dystrophy was diagnosed. The chest roentgenographic abnormalities were regarded as resulting from complications of this disease. Arterial blood gas analysis showed hypercapnic hypoxia and a spirogram showed that the vital capacity and maximum voluntary ventilation were about half of their respective predicted values. The hypercapnic ventilatory response was also abnormally low. An overnight study of oxygen saturation showed episodes of marked desaturation, and polysomnography revealed central sleep apnea. Inhalation of capsaicin showed an abnormally high cough threshold. Patients with undiagnosed myotonic dystrophy rarely present with chest roentgenographic abnormalities.

[The cause of paradoxical growth of intracranial tuberculomas during anti-tuberculous chemotherapy].

A case of multiple intracranial tuberculomas diagnosed by enhanced brain CT scan and MRI, which developed during the course of miliary tuberculosis under anti-tuberculous chemotherapy was experienced. Chemotherapy with an increased dose of each agent and corticosteroid was administered, and eventually intracranial tuberculomas nearly disappeared. After 1970, there have been 29 reported cases of intracranial tuberculomas in Japan, which were diagnosed by brain CT and treated with anti-tuberculous agents. Among them, 27 evaluable cases were classified into 3 groups. Group A: Intracranial tuberculomas were proved by CT before chemotherapy in 7 cases. Four of them enlarged during chemotherapy. Group B: During chemotherapy of tuberculous meningitis, neurological symptoms worsened or prolonged, and finally intracranial tuberculomas were found by CT in 9 cases. In 5 of them, after meningitis was improved by chemotherapy, neurological symptoms worsened and intracranial tuberculomas were found. Group C: During chemotherapy of pulmonary tuberculosis or miliary tuberculosis, neurological symptoms appeared and intracranial tuberculomas were found by CT in 11 cases (including our own case). Getting 3 groups together, intracranial tuberculomas seem to have worsened during chemotherapy in 24 out of 27 evaluable cases. In view of response to chemotherapy, these 24 cases can be divided into 2 categories: 1) non-responders to chemotherapy; 2) cases finally cured by chemotherapy ("transient worsening").(ABSTRACT TRUNCATED AT 250 WORDS)