21,639 research outputs found
A simplified holographic-interferometry technique for real-time flow visualization and analysis
A holographic-interferometry technique for flow visualization and analysis that produces real-time moire fringes is described from both experimental and application considerations. It has three chief advantages: real-time data for continuous observation and photography, ease of optical adjustment, and capability of using ordinary-glass test-section windows without affecting the results. A theoretical discussion is presented describing the formation of the fringes in holographic terms and then comparing this result to that which is obtained from a conventional moire approach. A discussion on obtaining density information from the fringe pattern is also included
Optimal MRI sequences for 68Ga-PSMA-11 PET/MRI in evaluation of biochemically recurrent prostate cancer.
BackgroundPET/MRI can be used for the detection of disease in biochemical recurrence (BCR) patients imaged with 68Ga-PSMA-11 PET. This study was designed to determine the optimal MRI sequences to localize positive findings on 68Ga-PSMA-11 PET of patients with BCR after definitive therapy. Fifty-five consecutive prostate cancer patients with BCR imaged with 68Ga-PSMA-11 3.0T PET/MRI were retrospectively analyzed. Mean PSA was 7.9 ± 12.9 ng/ml, and mean PSA doubling time was 7.1 ± 6.6 months. Detection rates of anatomic correlates for prostate-specific membrane antigen (PSMA)-positive foci were evaluated on small field of view (FOV) T2, T1 post-contrast, and diffusion-weighted images. For prostate bed recurrences, the detection rate of dynamic contrast-enhanced (DCE) imaging for PSMA-positive foci was evaluated. Finally, the detection sensitivity for PSMA-avid foci on 3- and 8-min PET acquisitions was compared.ResultsPSMA-positive foci were detected in 89.1% (49/55) of patients evaluated. Small FOV T2 performed best for lymph nodes and detected correlates for all PSMA-avid lymph nodes. DCE imaging performed the best for suspected prostate bed recurrence, detecting correlates for 87.5% (14/16) of PSMA-positive prostate bed foci. The 8-min PET acquisition performed better than the 3-min acquisition for lymph nodes smaller than 1 cm, detecting 100% (57/57) of lymph nodes less than 1 cm, compared to 78.9% (45/57) for the 3-min acquisition.ConclusionPSMA PET/MRI performed well for the detection of sites of suspected recurrent disease in patients with BCR. Of the MRI sequences obtained for localization, small FOV T2 images detected the greatest proportion of PSMA-positive abdominopelvic lymph nodes and DCE imaging detected the greatest proportion of PSMA-positive prostate bed foci. The 8-min PET acquisition was superior to the 3 min acquisition for detection of small lymph nodes
Influence of Dilute Acetic Acid Treatments on American Pondweed Winter Buds in the Nevada Irrigation District, California
American pondweed (
Potamogeton nodosus
Poir.) is commonly
found in northern California irrigation canals. The
purpose of this study was to test the hypothesis that exposure
of American pondweed winter buds to dilute acetic acid under
field conditions would result in reduced subsequent biomass
Settlement location models, archaeological survey data and social change in Bronze Age Crete
This paper builds spatial models of Bronze Age settlement using published survey datasets from the Mirabello region in east Crete. Methodologically, we examine how point process modelling can account for uncertainties in legacy survey datasets, and thereafter can highlight patterns of both cultural change and continuity in Mirabello settlement. Comparison of fitted models over different chronological periods gives an insight, we argue, into the kinds of settlement and subsistence choices that lay behind settlement patterns, holding constant the broadly similar environmental constraints faced by inhabitants throughout the Bronze Age. Overall, the results suggest prehistoric preference for, and exploitation of, agriculturally favourable parts of the landscape, although contrasting emphases in different periods do emerge despite this unsurprising overall preference. Many of the analytical results prove robust to a sensitivity analysis which addresses commonplace uncertainties associated with settlement survey data. The results also dovetail well with previous archaeological interpretations of changing settlement and Bronze Age life in the Mirabello region. Survey datasets are also relatively common in other archaeological settings worldwide and we advocate for more widespread application of similarly formalised methods to them
The effect of bedrest on various parameters of physiological function. part xi- the effect of bedrest on blood volume, urinary volume, and urinary electrolyte excretion
Effect of bed rest on blood volume, urinary volume, and urinary electrolyte excretio
The effect of bedrest on various parameters of physiological function. part viii- the . . . effect on the cardiovascular tolerance to passive tilt
Effect of short and long term bed rest on cardiovascular tolerance to passive til
The effect of bedrest on various parameters of physiological function. Part XIII - A review of possible mechanisms of orthostatic intolerance to passive tilt
Possible mechanisms of orthostatic intolerance to passive tilt - bed rest and water immersion effects on various parameters of physiological functio
The effect of bedrest on various parameters of physiological function. Part X - The effect of bedrest on the circulatory response to a valsalva maneuver
Quantitative arterial blood pressure change during Valsalva maneuver after bed res
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