Afterloading technique for interstitial irradiation of lesions in deep-seated organs

An afterloading procedure using iridium 192 seeds was developed for the control of both localized primary lesions that are difficult to remove and superficial residual lesions that remain after the partial removal of tumors in relatively inaccessible, deep-seated organs. This technique makes possible the delivery of a minimal radiation dose to lesions in deep-seated organs. Fewer complications result, the seeds can be adjusted at appropriate intervals in proportion to the amount of radioactivity desired, and radiation exposure to personnel can be reduced. This paper describes the techniques and apparatus used to place the seeds in the tubing. Primary lesions of the urinary bladder, the prostate gland, and the esophagus, residual lesions in the brain and lung, and metastases in intrapelvic lymph nodes were treated. No technical difficulties or complications were encountered. Radiation exposures to personnel were minimized. The results indicate that the procedure has practical applications.     

Study of static cushioning properties: Automated data input and reliability test of static cushioning properties

A computer-controlled compression testing machine is used to compile a database of the static cushioning properties of package cushioning materials. Through research into automated data input procedures, so far not developed, a direct transfer program (ZABCON) has been devised, which allows direct access to the disk in which compression test data are stored. Elimination of manual data input has led to simplified and easy construction of a database, and the applied laboratory tests, such as that for determining the relationship between static cushioning properties and compression rate, can be performed quite readily. Also in this report, the application of the static cushioning characteristics of foamed polystyrene in the cushioning package design of dummy goods and the evaluation of its reliability by drop testing are discussed.     

Polarising fibre coupler with high extinction ratio

Fused polarising fibre couplers have been fabricated using single-polarisation single-mode fibres. When circularly polarised light is fed into the coupler, one of the two orthogonal polarisation modes suffers strong attenuation, and only one polarisation mode couples in the fused biconical taper region. The extinction ratio of the coupler is 41 dB at a wavelength ? = 1.3 ?m with a coupling ratio of 48:52.     

Lower levels of physical functioning are associated with higher body weight among middle-aged and older women

OBJECTIVE: To compare levels of physical function, across levels of body mass index (BMI), among middle- to older-aged women. DESIGN: Cross-sectional study. Physical function, body weight and other covariates were measured in 1992. SUBJECTS: 56510 women aged 45-71 y, free of cardiovascular disease and cancer, participating in the Nurses' Health Study. MAIN OUTCOME MEASURES: The four physical function scores on the Medical Outcomes Study (MOS) Short Form-36 (SF36) Health Survey: physical functioning, vitality, bodily pain and role limitations. RESULTS: After adjusting for age, race, smoking status, menopausal status, physical activity and alcohol consumption, there was a significant dose-response gradient between increasing levels of BMI in 1992 and reduced function. For example, women with a BMI between 30-34.9 kg/m2 averaged: 9.0 point lower physical functioning score (95% Confidence interval (CI) -9.5, -8.5), 5.6 point lower vitality score (95% CI: -6.1, -5.1), and 7.0 point lower freedom from pain score (95% CI: -7.6, -6.4). These declines represent an approximate 10% loss of function compared to the reference category of women with BMIs ranging from 22.0-23.9 kg/m2. For the same BMI comparison, heavier women were at 66% increased risk of limitations in ability to work or perform other roles (RR = 1.66; 95% odds ratio (OR) CI: 1.56, 1.76). These findings were replicated when the sample was restricted to women who had maintained their BMI over a ten year period. CONCLUSIONS: In addition to increasing risk of chronic health conditions, greater adiposity is associated with lower every day physical functioning, such as climbing stairs or other moderate activities, as well as lower feelings of well-being and greater burden of pain.     

Microlens formation on VAD single-mode fibre ends

The letter describes microlens formation process on VAD single-mode fibre ends by a chemical-etching/fire-polishing technique. No central dip in the VAD fibres leads to high-quality lens formation.     

Synthesis of coherent two-port lattice-form optical delay-linecircuit

A method is presented for synthesizing a coherent two-port lattice-form optical delay-line circuit that is composed of optical delay lines, directional couplers, and phase shifters. The two bases of the method are the use of a unimodulus para-unitary matrix as a transfer matrix and the division of the transfer matrix into basic component transfer matrices. We succeeded in obtaining a set of recurrent equations with which to calculate circuit parameters to use for designing an optical delay-line circuit with a desired cross-port (through-port) transfer function. In the developed method, it is shown that two-port optical delay-line circuits can have the same transmission characteristics as finite impulse response digital filters with complex expansion coefficients. Three synthesis examples for optical frequency filters are described: a linear-phase Chebyshev filter, a multi-channel selector, and a group-delay dispersion equalizer. It is confirmed that transmission characteristics with a maximum transmittance of 100% can be always synthesized. The allowable parameter error for the synthesized linear-phase Chebyshev filter is also discussed     

Nondestructive evaluation of coupling constants in single-modeoptical channel waveguides

A nondestructive method is proposed for evaluating power coupling coefficients of directional couplers contained in an optical integrated circuit. This technique, which is based on optical heterodyne interferometry, makes it possible to obtain individual coupler element information without removing the element from the optical circuit. General N-channel waveguide coupling characteristics are analyzed, and they are experimentally evaluated for two- and four-channel waveguides that have been practically designed as frequency multi/demultiplexers operating in the 1.55-μm-wavelength region     

Experimental gastric cancer (author's transl)

Methods have been established to produce gastric cancer in rats and dogs by administration of N-methyl-N'-nitro-N-nitrosoguanidine or of the ethyl derivate. The agent is administered in drinking water or by a pellet diet soaked in the carcinogen. Histologically well differentiated and poorly differentiated types of adenocarcinoma and signet-ring cell tumors are induced in several months with greath reliability. Metastases were observed in both rats and dogs with gastric carcinoma. The carcinogenic effect could be enhanced by surface active agents, sodium chloride, iodoacetamide, insertion of plastic beads into the stomach and gastroenteroanastomosis. Follow-up studies by radiologic, endoscopic and bioptic examinations are possible in the dog. There are similarities in these experimental tumors to those in man and thus they provide means for the investigation of histogenesis, prevention, and chemotherapy of gastric cancer. An adenocarcinoma of the glandular stomach of a Wistar rat was successively transplanted to new born rats of the same strain.