Noncontacting device to indicate deflection of turbopump internal rotating parts

Phase 2 (development) which was concluded for the ultrasonic Doppler device and the light-pipe-reflectance device is reported. An ultrasonic Doppler breadboard system was assembled which accurately measured runout in the J-2 LOX pump impeller during operation. The transducer was mounted on the outside of the pump volute using a C-clamp. Vibration was measured by conducting the ultrasonic wave through the volute housing and through the fluid in the volute to the impeller surface. The impeller vibration was also measured accurately using the light-pipe probe mounted in an elastomeric-gland fitting in the pump case. A special epoxy resin developed for cryogenic applications was forced into the end of the fiber-optic probe to retain the fibers. Subsequently, the probe suffered no damage after simultaneous exposure to 2150 psi and 77 F. Preliminary flash X-radiographs were taken of the turbine wheel and the shaft-bearing-seal assembly, using a 2-megavolt X-ray unit. Reasonable resolution and contrast was obtained. A fast-neutron detector was fabricated and sensitivity was measured. The results demonstrated that the technique is feasible for integrated-time measurements requiring, perhaps, 240 revolutions to obtain sufficient exposure at 35,000 rpm. The experimental verification plans are included

Noncontacting devices to indicate deflection and vibration of turbopump internal rotating parts

Published report discusses feasibility of ultrasonic techniques; neutron techniques; X-radiography; optical devices; gamma ray devices; and conventional displacement sensors. Use of signal transmitters in place of slip rings indicated possible improvement and will be subject of futher study

Sensitivity of cold acclimation to elevated autumn temperature in field-grown Pinus strobus seedlings

Climate change will increase autumn air temperature, while photoperiod decrease will remain unaffected. We assessed the effect of increased autumn air temperature on timing and development of cold acclimation and freezing resistance in Eastern white pine (EWP, Pinus strobus) under field conditions. For this purpose we simulated projected warmer temperatures for southern Ontario in a Temperature Free-Air-Controlled Enhancement (T-FACE) experiment and exposed EWP seedlings to ambient (Control) or elevated temperature (ET, +1.5°C/+3°C during day/night). Photosynthetic gas exchange, chlorophyll fluorescence, photoprotective pigments, leaf non-structural carbohydrates (NSC), and cold hardiness were assessed over two consecutive autumns. Nighttime temperature below 10°C and photoperiod below 12 h initiated downregulation of assimilation in both treatments. When temperature further decreased to 0°C and photoperiod became shorter than 10 h, downregulation of the light reactions and upregulation of photoprotective mechanisms occurred in both treatments. While ET seedlings did not delay the timing of the downregulation of assimilation, stomatal conductance in ET seedlings was decreased by 20–30% between August and early October. In both treatments leaf NSC composition changed considerably during autumn but differences between Control and ET seedlings were not significant. Similarly, development of freezing resistance was induced by exposure to low temperature during autumn, but the timing was not delayed in ET seedlings compared to Control seedlings. Our results indicate that EWP is most sensitive to temperature changes during October and November when downregulation of photosynthesis, enhancement of photoprotection, synthesis of cold-associated NSCs and development of freezing resistance occur. However, we also conclude that the timing of the development of freezing resistance in EWP seedlings is not affected by moderate temperature increases used in our field experiments

Regional chemotherapy of neoplastic diseases

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25399/1/0000848.pd

Determination of plasma trimetrexate levels using gas chromatography--mass spectrometry with selected-ion monitoring

Trimetrexate is a potent inhibitor of dihydrofolate reductase and has demonstrated significant antitumor activity against murine and human cell lines both in vitro and against several murine transplanted tumors. The importance of antifolate concentration and exposure time in determining toxic and therapeutic effects necessitates an assay of suitable sensitivity, accuracy and specifity for investigation of trimetrexate pharmacokinetics. This paper describes a gas chromatographic--mass spectrometric (GC--MS) procedure using selected-ion monitoring (SIM) for the determination of plasma trimetrexate levels. Using the C18 Bond-Elut extraction columns, the drug and internal standard are removed from plasma, derivatized to their bis(trimethylsilyl) derivatives and analysed by GC--SIM-MS. The reproducibility of the daily standard curves had coefficients of variation ranging from 4.9 to 11.4%. The precision of the assay yielded a coefficient of variation ranging from 5.6 to 10.1%, and the concentration means for the seeded control samples were found to be within -3.7 to +0.7% of the theoretical values for trimetrexate. No interfering peaks have been observed in application of the procedure on patient samples. The minimum detectable level under the conditions described was 0.005-0.014 [mu]M trimetrexate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26336/1/0000423.pd

Improved regional selectivity of hepatic arterial mitomycin by starch microspheres

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109929/1/cptclpt1983163.pd

Contrasting effects of sleep fragmentation and angiotensin-II treatment upon pro-inflammatory responses of mice

Disordered sleep promotes inflammation in brain and peripheral tissues, but the mechanisms that regulate these responses are poorly understood. One hypothesis is that activation of the sympathetic nervous system (SNS) from sleep loss elevates blood pressure to promote vascular sheer stress leading to inflammation. As catecholamines produced from SNS activation can directly regulate inflammation, we pharmacologically altered blood pressure using an alternative approach-manipulation of the renin-angiotensin system (RAS). Male C57BL6/J mice were treated with angiotensin or captopril to elevate and reduce blood pressure, respectively and then exposed to 24-h of sleep fragmentation (SF) or allowed to sleep (control). Pro- and anti-inflammatory cytokine gene expression and as endothelial adhesion gene expression as well as serum glucocorticoids (corticosterone) were measured. RAS manipulation elevated cytokines and endothelial adhesion expression in heart and aorta while SF increased cytokine expression in peripheral tissues, but not brain. However, there were interactive effects of angiotensin-II and SF upon cytokine gene expression in hippocampus and hypothalamus, but not prefrontal cortex. SF, but not RAS manipulation, elevated serum corticosterone concentration. These findings highlight the contrasting effects of RAS manipulation and SF, implying that inflammation from SF is acting on different pathways that are largely independent of RAS manipulation

Sensitive high-performance liquid chromatographic method for the determination of 5-fluorouracil in plasma

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25895/1/0000458.pd