RESUMO
The dense plasma focus (DPF) device-DPF-1000U which is operated at the Institute of Plasma Physics and Laser Microfusion is the largest that type plasma experiment in the world. The plasma that is formed in large plasma experiments is characterized by vast numbers of parameters. All of them need to be monitored. A neutron activation method occupies a high position among others plasma diagnostic methods. The above method is off-line, remote, and an integrated one. The plasma which has enough temperature to bring about nuclear fusion reactions is always a strong source of neutrons that leave the reactions area and take along energy and important information on plasma parameters and properties as well. Silver as activated material is used as an effective way of neutrons measurement, especially when they are emitted in the form of short pulses like as it happens from the plasma produced in Dense Plasma-Focus devices. Other elements such as beryllium and yttrium are newly introduced and currently tested at the Institute of Plasma Physics and Laser Microfusion to use them in suitable activation neutron detectors. Some specially designed massive indium samples have been recently adopted for angular neutrons distribution measurements (vertical and horizontal) and have been used in the recent plasma experiment conducted on the DPF-1000U device. This choice was substantiated by relatively long half-lives of the neutron induced isotopes and the threshold character of the 115In(n,n')115mIn nuclear reaction.
RESUMO
The spectra of neutrons outside the plasma focus device PF-1000 with an upper energy limit of ≈1 MJ was measured using a Bonner spheres spectrometer in which the active detector of thermal neutrons was replaced by nine thermoluminescent chips. As an a priori spectrum for the unfolding procedure, the spectrum calculated by means of the Monte Carlo method with a simplified model of the discharge chamber was selected. Differences between unfolded and calculated spectra are discussed with respect to properties of the discharge vessel and the laboratory layout.
RESUMO
Two hundred and forty-one patients were treated with radical hysterectomy at our institution between 1949 and December, 1978. The corrected 5-year survival rate for all patients with squamous cell carcinoma of the cervix was 73%. Seventeen percent of patients with occult invasive carcinoma had positive lymph nodes at the time of operation. The corrected 5-year survival rate for patients with Stage IB carcinoma who had positive nodes was 66%. Operations for recurrent or persistent disease after radiotherapy resulted in a 5-year survival rate of 54%. Current indications for radical hysterectomy and lymphadenectomy at our center are discussed.
PIP: This study reports the center's experience (Cancer Control Agency of British Columbia or CCABC and the Vancouver General Hospital) with 241 patients (aged 20 to 71+) who had undergone radical hysterectomy for invasive cancer during the period 1949 through 1978, and how this experience has led to the center's current indications for use of such surgical procedural procedure. Approximately 50% of the patients were aged 40 years or less, and 2/3 were under the age of 51; this suggests that most patients have long life expectancy if they could be cured of their disease. All but 15 patients had primary cervical carcinoma (Table 2). 76% of the patients had squamous cell carcinoma of the cervix. Of the 226 cervical cancers, 81.9% were squamous cell and 12.4% were adenocarcinoma. 5.6% had a mixed adenosquamous carcinoma. Diagnosis of cervical cancer correlated closely with the presence or absence of lymph node involvement at time of operation. Tables were also provided to present data on 5-year survival rates of patients with positive lymph nodes and squamous cell carcinoma; various treatment methods and results by stage for the 137 patients with squamous cell carcinoma of the cervix; 10, 15 and 20 year survival rates by stage for patients with squamous cell carcinoma; postoperative complications in 241 patients, and effect of radiotherapy on rate of development of fistulas. The data shows that radical hysterectomy was not a commonly performed procedure in this institution during the past 3 decades, and the encouraging 52% survival rate for patients managed with radical hysterectomy for recurrence or persistence of cancer after radiotherapy indicates the need for frequent, careful follow-up of patients with early stages of cancer. Current indications for radical hysterectomy and lymphadenectomy at CCABC are discussed.