Thermal beam of metastable krypton atoms produced by optical excitation

A room-temperature beam of krypton atoms in the metastable 5s[3/2]2 level is demonstrated via an optical excitation method. A Kr-discharge lamp is used to produce vacuum ultraviolet photons at 124 nm for the first-step excitation from the ground level 4p6 1S0 to the 5s[3/2]1 level. An 819 nm Ti:sapphire laser is used for the second-step excitation from 5s[3/2]1 to 5s[3/2]2 followed by a spontaneous decay to the 5s[3/2]2 metastable level. A metastable atomic beam with an angular flux density of 3 x 10(14) s(-1) sr(-1) is achieved at the total gas flow rate of 0.01 cm3/s at STP (or 3 x 10(17) at./s). The dependences of the flux on the gas flow rate, laser power, and lamp parameters are investigated.

Frequency-stabilized diode laser with the Zeeman shift in an atomic vapor

We demonstrate a robust method of stabilizing a diode laser frequency to an atomic transition. This technique employs the Zeeman shift to generate an antisymmetric signal about a Doppler-broadened atomic resonance, and therefore offers a large recapture range as well as high stability. The frequency of a 780-nm diode laser, stabilized to such a signal in Rb, drifted less than 0.5 MHz peak-peak (1 part in 10(9)) in 38 h. This tunable frequency lock can be constructed inexpensively, requires little laser power, rarely loses lock, and can be extended to other wavelengths by use of different atomic species.

[Thoracic gastric and large area necrotic perforation of the neck gastric wall after surgery of esophageal and cardial cancer: analysis of 9 cases]

Nine cases of gastric perforation after operation for esophageal were reported. Eight cases were esophageal cancer. One case was cardial cancer. Five of the nine cases were anastomosed in intrathorax, and four in neck. Intrathoracic gastric perforation occurred in six cases. Five of them were operated on again. Gastric perforation in neck occurred in three cases. The nine cases were all cured. This article analysed the reasons of the gastric perforation and emphasised that early diagnosis, early operation or drainage in neck were the key steps in treatment.

[Sharing antigenic determinant of colon carcinoma between serous and mucinous tumors of the ovary]

Expression of colon-ovarian tumor antigen (COTA) in serous and mucinous tumors of the ovary was determined immunohistochemically, using monoclonal antibody SC13A against colon carcinoma antigen as a probe. In 67 serous tumor of the ovary, the frequency of expression was 90.0% in the cystadenocarcinomas, 71.4% in the borderline cystadenomas, and only 8.0% in the cystadenomas. In 44 mucinous tumors of the ovary, the SC13A marker was expressed in 87.5% of the malignant tumors, 80.0% of the borderline tumors, and 25.8% of the benign cystadenomas. And in 20 samples of normal ovarian tissue a negative immunostaining for the SC13A was found. These findings showed that the serous and the mucinous tumors share the same antigenic determinant of colon cancer, and the percentage expression of which is significantly higher in the malignant than in the benign and the borderline tumors, as well as in the normal ovarian tissues (P < 0.005). The marker might be valuable for further studies of these tumors.

[Significance of perioperative elevation of blood viscosity in patients with esophageal or cardiac carcinoma]

The blood viscosity of 21 patients with esophageal or cardiac carcinoma during preoperative period was measured and compared with that of 25 healthy persons. The results indicate that the blood viscosity in patients is higher than that in the control group (P < 0.001) immediately and one day after operation. Elevation of blood viscosity is not only related to myocardial infarction, but also may be one of the causes for the poor therapeutic effect in patients with carcinomas. It is suggested that proper measures should be taken to control the elevating blood viscosity in patients, especially the elderly ones during the perioperative period. Colloid fluid which is believed to increase blood viscosity should be avoided within the first two days after operation to prevent cardiac complications.

[Serum testosterone level in patients with cardiac or gastric carcinoma before and after surgery]

Serum testosterone level (STL) was determined in 52 male patients with cardiac carcinoma and in 48 male patients with gastric carcinoma before and after operation, and in 54 normal male subjects and preoperative 40 male patients with benign diseases as control groups. The STL of the patients with cardiac carcinoma or gastric carcinoma was lower than the normal group and the benign diseases group (P less than 0.001, respectively). The postoperative STL of the patients with cardiac or gastric carcinoma was not significantly different from the normal group and the benign diseases group. The STL was lower in patients with recurrence than in the normal group and benign diseases group (P less than 0.001, respectively), and lower in patients with cardiac or gastric carcinoma invading outside the serosa than in those with lesions confined to the musculature (P less than 0.001 and P less than 0.05). Therefore, it appears that the STL may be an important parameter in diagnosis, and in the evaluation of prognosis, postoperative recurrence and resectability of the tumors.

[Serum testosterone level of patients with cardiac or gastric carcinoma]

Serum testosterone level (STL) was examined in 25 male patients with cardiac or gastric carcinoma before and after operation and 28 male patients with benign diseases as control. The preoperative STL of patients with carcinoma was lower than that of the control (P less than 0.001). Postoperatively STL of these patients rose to the level of control group. When cancer recurred, STL again dropped to low level. STL was lower when cancer had invaded beyond the serosa than that limited to the musculature. Therefore, STL may be a good parameter for diagnosis and prognosis in patients with cancer of the stomach and gastric cardia.