Ultrasonic examinations conducted in order to diagnose the depth of invasion and local lymph node metastases of rectal cancer. The intrarectal approach was performed preoperatively in 99 patients with rectal cancer, using either an Olympus-Aloka ultrasonic endoscopeTM (7.5 MHz) or other probes (Aloka, 7.5 MHz, 5 MHz). Through this method, intrapelvic organs were detected clearly, and hypoechoic findings due to tumors were detected in all patients. The normal rectal wall was echogenically divided into five layers, the third layer being the submucosal and the fourth layer being the proper muscle layer. In some cases, the proper muscle layer was divided into three layers in the echogram. In 79 of 88 patients, the diagnosis of depth of invasion, classified into three groups, was possible. Metastatic lymph nodes were shown as a hypoechoic round mass. In 52 of 71 patients proven to have local lymph node metastases in surgical specimens, lymph node metastases were diagnosed preoperatively. Thus, intrarectal ultrasonography provides valuable information concerning the choice of operating methods for rectal cancer.

Hydrothermal synthesis of potassium hexatitanate was carried out under various subcritical and supercritical water conditions using potassium hydroxide and titanium tetraisopropoxide as starting materials. Characterization of these hydrothermally synthesized potassium hexatitanates by XRD, SEM, TEM, and thermal analysis showed that long, felted-like fibers of potassium hexatitanates were formed and these fibers are thermally stable up to 1273 K. The use of these fibers as photocatalysts in water decomposition was investigated using ruthenium oxide as the catalytic active phase. Photocatalytic activitiy in the water decomposition reaction was found to be much higher in comparison with the solid state synthesized photocatalyst. Activites of more than 13-fold were obtained for the photocatalysts synthesized under subcritical water conditions and between 27- and 59-fold for those synthesized under supercritical water conditions for water decomposition.

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