Identification of chlorinated styrenes in cormorant tissues by a computerized gas chromatography-mass spectrometry system

The results of a study concerning the identification of three unknown compounds which were detected in extracts of cormorant tissue are reported. From these results it has been concluded that one of the compounds is octachlorostyrene. It is highly probable that the other two compounds are heptachlorostyrenes. Octachlorostyrene was also detected in fish, seals and various other aquatic bird species.     

Effects of GABA, glycine, picrotoxin and bicuculline methochloride on rubrospinal neurones in cats

A microelectrophoretic study was performed of the actions of GABA and glycine, and of their antagonists on rubrospinal neurones. GABA and glycine depressed antidromic and synaptic potentials, hyperpolarized the cell membrane and increased the membrane conductance. GABA was more effective than glycine. Corticorubral IPSPs and the GABA-induced membrane hyperpolarization could be reversed by intracellular application of hyperpolarizing currents. Picrotoxin and bicuculline methochloride antagonized inhibitory GABA actions and the corticorubral IPSP or the corresponding extracellular positive field potential. The results support the hypothesis that GABA is the transmitter of the corticorubral inhibition in the cat.     

DESIGN AND APPLICATION OF A DEHUMIDIFIER DRYER FOR DRYING PINE CONES AND POLLEN CATKINS

A critical issue for the plantation forest industry is the preservation and control of genetic material in order to facilitate the fertilisation process. This is best achieved by drying at low temperature and low humidity prior to extraction of seeds and pollen. For example, freshly picked green cones of Pinus radiata are best dried at 25°C, 20% relative humidity to avoid thermal damage and to prevent mould formation. Similar conditions are required for drying pollen catkins. These conditions can be met efficiently and reliably by the use of a dehumidifier dryer. This paper describes the design of such a drying system, including a review of the dehumidifier and the kiln design parameters necessary to achieve the required drying conditions. Performance data and commercial operating experience are also presented and analysed. The system is effective and reliable, and has increased both the speed of drying and the quality of the product.     

Analysis of a mini-sandwich compression test specimen

Mini-sandwich compression specimens have been analyzed by using a rule-of-mixtures approach and a finite element method which takes into account the mechanical and non-mechanical loadings. The results of stress analysis are illustrated for an [(ASA4/3501-60/3501-6]_s specimen and an [(AS4/APC-2)/APC-2]_s specimen as examples. Both specimen configurations contain face sheets consisting of two plies of O° orientation. The compressive strengths of these two unidirectional composites were computed from the experimentally measured strengths of the mini-sandwich specimen and the stress state predicted by the present analysis. The present result shows that a rule-of-mixtures approach can cause considerable error in the interpretation of the compressive strength of unidirectional face sheets. Procedures for the accurate determination of the compressive strengths of the face sheets for mini-sandwich specimens are presented. A simplified non-linear approach reveals that it is important to consider the final tangent or secant material properties rather than the initial material properties to obtain accurate stress distributions of the specimen prior to failure.     

Results of high-dose thoracic irradiation incorporating beam's eye view display in non-small cell lung cancer: a retrospective multivariate analysis

PURPOSE: To review the University of Michigan clinical experience in nonsmall cell lung cancer using high-dose thoracic irradiation (> or = 60 Gy) so that a starting dose for our prospective dose-escalation study could be determined. METHODS AND MATERIALS: Eighty-eight consecutive patients diagnosed with medically inoperable or locally advanced, unresectable nonsmall cell lung cancer were identified who were treated with thoracic irradiation alone to a minimum total dose of 60 Gy (uncorrected for lung density). All patients except four (95%) underwent computed tomography scanning for treatment planning that included beam's eye view display for tumor and critical structure localization. All patients were treated with standard fractionation in a continuous course to uncorrected total doses ranging from 60 to 74 Gy (median, 67.6 Gy). RESULTS: The median follow-up exceeds 24 months for all surviving patients (range, 12 to 78 months). The median survival time was 15 months, and the 2- and 3-year overall actuarial survival rates were 37% and 15%, respectively. Survival was significantly different between stage of disease (p = .004) and N-stage (p = .002) by univariate analysis. In a multivariate analysis, stage becomes the only characteristic significantly associated with outcome. The median time to local progression for 86 evaluable patients was 29 months. Stage (p = .0003), T-stage (p = .0095) and N-stage (p = .027) were significantly different with respect to local progression-free survival by univariate analysis. However, only stage was prognostic for local progression-free survival by multivariate analysis. There was no difference between large volume treatment (inclusion of the contralateral hilar and supraclavicular lymph nodes) and small volume treatment (exclusion of these elective nodal sites) with respect to local progression-free survival (p = .507) or survival (p = .520). With regard to dose, there was no significant difference between patients who received > 67.6 Gy and patients who received < or = 67.6 Gy with respect to local progression-free survival (p = .094) or survival (p = .142). Within the Stage III subgroup, local progression-free survival (p = .018) and survival (p = .061) were longer favoring the high-dose group of patients. Despite these doses, disease progression within the irradiated field was the predominant first site of treatment failure. CONCLUSION: This retrospective study has shown that it is feasible to deliver uncorrected tumor doses as high as 70 Gy using standard fractionation in NSCLC with acceptable morbidity. Local control remains a significant problem. These data indicate justification for a starting dose in a prospective radiation dose-escalation study.     

Survey of the contamination of Dutch coastal waters by chlorinated hydrocarbons,including the occurrence of methylthio-pentachlorobenzene and di-(methylthio)tetrachlorobenzene

In 1976 contamination of Dutch coastal waters by organochlorine compounds was assessed by analysing mussels, Mytilus edulis, as an indicator-organism. HCB, dieldrin, endrin, p,p′-DDT, p,p′-TDE and PCB's were detected, and also two new compounds previously unknown in the aquatic fauna.Using gas-liquid chromatography, mass spectrometry and ¹³C nuclear magnetic resonance spectrometry these could be identified as methylthiopentachlorobenzene and 1,4-di(methylthio)-2,3,5,6-tetrachlorobenzene. Their concentrations in the mussels ranged from 0.005 to 0.40 mg/kg on a fresh weight basis, depending on sampling site. Their presence is associated with the exposure of mussels to water from the river Rhine. Further work is required to establish the origin of these compounds and their possible precursors.     

221厂核设施退役工程的竣工验收辐射检测

本文叙述２２１厂核设施退役工程的竣工验收辐射检测，内容涉及竣工验收辐射检测小组的职能和组织形式，验收检测标准，验收检测的实施及其主要结果。     

A room-based diagnostic imaging system for measurement of patient setup

A room-based diagnostic x-ray imaging system for routine measurement of radiotherapy patient orientation has been developed. The system consists of a pair of room-mounted x-ray tubes and a portable imager consisting of an orthogonal pair of phosphor screens, a mirror/lens system, a CCD camera, and computer software for comparing images of the patient to reference images. Orthogonal pairs of images can be acquired quickly and with relatively little exposure, allowing correction of patient setup on a daily basis. This could limit patient setup error to the uncertainty in the measurement and repositioning processes, a potentially significant improvement over the present standard.     

Improved convergence of Lyapunov model reference adaptive systems by a parameter misalignment function

A modified approach is presented for the design of Lyapunov model reference adaptive systems. The approach introduces the use of a function of the parameter misalignment, which can be generated with minor demands for additional hardware. Simulation confirms the acceleration in convergence of the system error compared to previous design procedures.