Continuous recording of arteriolar dimensions with a television microscope

1963 ◽  
Vol 18 (5) ◽  
pp. 1041-1042 ◽  
Author(s):  
Curt A. Wiederhielm
Keyword(s):  
Experimental Study ◽  
Electron Beam ◽  
Viscoelastic Properties ◽  
Continuous Recording ◽  
Time Interval ◽  
Short Term ◽  
Small Arteries ◽  
Glass Capillaries ◽  
Time Required ◽  
Analog Voltage

A system which permits continuous recording of dimensions of microscopic blood vessels is described. The system utilizes information contained in the video signal of a television microscope to develop an analog voltage proportional to the time required for the electron beam to sweep across the image of the blood vessel. This time interval is also proportional to the dimension of the vessel. Calibration of the system yielded a standard error of estimate of ±3.7 μ on a series of glass capillaries, ranging in size from 15 to 150 μ. The rise time of the system was in the order of 40 msec. Long- and short-term drift was less than 3 μ/hr. The system is used in an experimental study of viscoelastic properties of small arteries and arterioles. microcirculation; viscoelastic properties; frog mesentery Submitted on April 17, 1963

scholarly journals A Near-Surface Layer Heat Treatment of Die Casting Dies by Means of Electron-Beam Technology

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1236
Author(s):  
Torsten Schuchardt ◽  
Sebastian Müller ◽  
Klaus Dilger
Keyword(s):  
Heat Treatment ◽  
Boundary Layer ◽  
Surface Layer ◽  
Electron Beam ◽  
Process Planning ◽  
Die Casting ◽  
Time Interval ◽  
Short Term ◽  
Simulation Based ◽  
Temperature Time

Increasing the service life of die casting dies is an important goal of the foundry industry. Approaches are either material- or process-related. Despite new material concepts, hot work steels such as H11 are still predominantly used in the uncoated condition for die casting dies. In order to withstand the stresses that occur, this steel is used exclusively in the quenched and tempered condition. Required properties such as high high-temperature strength and high hardness combined with high toughness are, in principle, contradictory and can only be adjusted consistently over the entire die by furnace-based heat treatment. However, the results of various investigations have shown that improvements in the thermal shock resistance and wear resistance of hot work tool steels can be achieved by thermally influencing the microstructure near the surface. Based on these studies and related findings, an approach to surface heat treatment using the electron beam was developed. Due to the particle character of the radiation and the associated possibility of high-frequency beam deflection, the electron beam offers significantly greater flexibility in energy input into the workpiece surface compared with lasers or induction. The overall technological concept envisages replacing furnace-based heat treatment in the production of casting dies by localized and demand-oriented boundary layer heat treatment with the electron beam. The experiments include, on the one hand, the experimental determination of a suitable temperature–time interval with a focus on short-term austenitization. On the other hand, a simulation-based approach of boundary layer heat treatment with validation of a suitable heat source is investigated. Regarding short-term austenitization, the corresponding temperature and time range could be narrowed down more precisely. Some of these parameter combinations seem to be very suitable for practical use. The test specimens show a hard surface layer with a depth of at least up to 6 mm and a very tough buffer layer. Numerical simulation is used to estimate the resulting metallurgical microstructure and the achievable hardness as a function of the temperature–time interval. In addition, the results provided show the possibility of determining and optimizing the material properties by means of a simulation-based approach within the framework of a purely digital process planning and subsequently transferring them into a process planning. In the technical implementation, a temperature control was first established by means of a two-color pyrometer. In the further course of research, the pyrometer will be supplemented by an internally installed infrared camera, which will allow the reproducible setting of specified temperature profiles even for complex, large-area contours in the future.

scholarly journals Time Interval to Biochemical Failure as a Surrogate End Point in Locally Advanced Prostate Cancer: Analysis of Randomized Trial NRG/RTOG 9202

2019 ◽  
Vol 37 (3) ◽  
pp. 213-221 ◽  
Author(s):  
James J. Dignam ◽  
Daniel A. Hamstra ◽  
Herbert Lepor ◽  
David Grignon ◽  
Harmar Brereton ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Randomized Trial ◽  
Locally Advanced ◽  
Biochemical Failure ◽  
Mediating Effect ◽  
Time Interval ◽  
Short Term ◽  
End Points ◽  
End Point

Background In prostate cancer, end points that reliably portend prognosis and treatment benefit (surrogate end points) can accelerate therapy development. Although surrogate end point candidates have been evaluated in the context of radiotherapy and short-term androgen deprivation (AD), potential surrogates under long-term (24 month) AD, a proven therapy in high-risk localized disease, have not been investigated. Materials and Methods In the NRG/RTOG 9202 randomized trial (N = 1,520) of short-term AD (4 months) versus long-term AD (LTAD; 28 months), the time interval free of biochemical failure (IBF) was evaluated in relation to clinical end points of prostate cancer–specific survival (PCSS) and overall survival (OS). Survival modeling and landmark analysis methods were applied to evaluate LTAD benefit on IBF and clinical end points, association between IBF and clinical end points, and the mediating effect of IBF on LTAD clinical end point benefits. Results LTAD was superior to short-term AD for both biochemical failure (BF) and the clinical end points. Men remaining free of BF for 3 years had relative risk reductions of 39% for OS and 73% for PCSS. Accounting for 3-year IBF status reduced the LTAD OS benefit from 12% (hazard ratio [HR], 0.88; 95% CI, 0.79 to 0.98) to 6% (HR, 0.94; 95% CI, 0.83 to 1.07). For PCSS, the LTAD benefit was reduced from 30% (HR, 0.70; 95% CI, 0.52 to 0.82) to 6% (HR, 0.94; 95% CI, 0.72 to 1.22). Among men with BF, by 3 years, 50% of subsequent deaths were attributed to prostate cancer, compared with 19% among men free of BF through 3 years. Conclusion The IBF satisfied surrogacy criteria and identified the benefit of LTAD on disease-specific survival and OS. The IBF may serve as a valid end point in clinical trials and may also aid in risk monitoring after initial treatment.

Experimental study of the possibility to increase the pitch factor of an intense relativistic helical electron beam

2008 ◽  
Vol 51 (10) ◽  
pp. 772-779 ◽  
Author(s):  
E. V. Ilyakov ◽  
I. S. Kulagin ◽  
V. N. Manuilov ◽  
A. S. Shevchenko
Keyword(s):  
Experimental Study ◽  
Electron Beam ◽  
Pitch Factor ◽  
Helical Electron Beam

Inter-Repetition Interval in Short-Term Motor Memory

1975 ◽  
Vol 40 (2) ◽  
pp. 535-538 ◽  
Author(s):  
Philip H. Marshall ◽  
Susan L. Wyatt ◽  
Shirley A. Moore ◽  
Stephen E. Sigman
Keyword(s):  
Short Interval ◽  
Motor Memory ◽  
Time Interval ◽  
Short Term ◽  
Verbal Responses ◽  
Motor Movement ◽  
Repetition Interval ◽  
Improved Accuracy

An investigation was conducted to ascertain the influence of the duration of the time interval between successive repetitions of a discrete motor movement in a short-term motor memory paradigm. With one repetition a long interval increased error relative to a short interval. The opposite was true for seven repetitions; a long interval improved accuracy. The results were discussed in terms of the “trace shrinkage” hypothesis and compared with those from similar studies using verbal responses.

scholarly journals Vascular Matrix Metalloproteinase-9 Mediates the Inhibition of Myogenic Reactivity in Small Arteries Isolated from Rats after Short-Term Administration of Relaxin

Endocrinology ◽  
2007 ◽  
Vol 148 (1) ◽  
pp. 189-197 ◽  
Author(s):  
Arundhathi Jeyabalan ◽  
Jacqueline Novak ◽  
Ketah D. Doty ◽  
Julianna Matthews ◽  
Michelle C. Fisher ◽  
...  
Keyword(s):  
Matrix Metalloproteinase ◽  
Matrix Metalloproteinase 9 ◽  
Short Term ◽  
Small Arteries ◽  
Term Administration ◽  
Metalloproteinase 9
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