STATIC ELASTIC MODULUS OF THE TURKEY AORTA

1964 ◽  
Vol 42 (4) ◽  
pp. 553-562 ◽  
Author(s):  
Elwood W. Speckmann ◽  
Robert K. Ringer
Keyword(s):  
Blood Pressure ◽  
Elastic Modulus ◽  
Pressure Range ◽  
Elastic Moduli ◽  
Mature Male ◽  
Elevated Pressures ◽  
Arterial Blood ◽  
Blood Pressure Range ◽  
Thoracic And Abdominal

A method was described for the determination of the static elastic modulus for thoracic and abdominal aortas of the turkey. Love's equation was rearranged for calculation of the static elastic modulus as a function of volume. The elastic moduli of thoracic and abdominal aortas of untreated mature male Broad Breasted Bronze turkeys were in the neighborhood of 2.26 ± 0.11 and 9.55 ± 0.30 × 105 dynes/cm2 respectively in the normal physiological systolic blood pressure range. This difference became more pronounced at higher pressures. The data obtained support the concept that different connective tissue elements are primarily responsible for the elastic properties of arterial blood vessels at different pressure ranges. The addition of beta-amino-propionitrile (BAPN) to the ration tended to decrease, whereas the addition of ascorbic acid to the ration tended to elevate the elastic modulus. Reserpine fed in conjunction with BAPN in the ration did not correct the lowering action of BAPN on the elastic moduli of abdominal or thoracic aortas. Heat tended to elevate the elastic modulus of the aorta. Again, these effects became more significant at elevated pressures.

scholarly journals Tracking blood pressure changes by means of non-invasive intermittent blood pressure measurements in clinical application

2021 ◽  
Vol 7 (2) ◽  
pp. 815-818
Author(s):  
Robert Huhle ◽  
Thorsten Richter ◽  
Marcelo Gama de Abreu
Keyword(s):  
Blood Pressure ◽  
Arterial Blood Pressure ◽  
Pressure Range ◽  
Tracking Error ◽  
Correlation Coefficients ◽  
Non Invasive ◽  
Arterial Blood ◽  
The Mean ◽  
Blood Pressure Range ◽  
Pressure Changes

Abstract Considering accuracy/precision cut-offs of 5 ± 8 mmHg and cut-off values for inter-class correlation coefficients (ICC=0.37...1, from DIN EN ISO 81060-2), absolute and relative errors in time independent measurement of blood pressure changes with non-invasive intermittent devices (NiBP) are derived mathematically for mean arterial blood pressure range of 40-180 mmHg. As a clinically relevant value for change of arterial blood pressure 20% of the baseline blood pressure is considered. The mean ratio between the change of BP measured by the NiBP and measured by the invasive reference device (TE%) were proposed as quality measure for the evaluation of NiBP device tracking capability. The proposed measure TE%is theoretically independent of absolute accuracy but depends on precision and ICC of a device. NiBP devices show considerable maximum TE% of 41% in tracking mean blood pressure changes respectively. In 10% of the measurements in the low blood pressure range TE% exceeding 100%. The mean 50th/90th TE% percentile over the whole blood pressure range were 25/61%, respectively. Furthermore, TE% was relatively insensitive to assumed blood pressure range but sensitive to ICC. NiBP devices have high relative error in tracking blood pressure changes that make those devices not well-suited for tracking blood pressure changes. The proposed tracking error allows the definition of reasonable accuracy/precision requirements of NBP devices.

VOLUME–PRESSURE RELATIONSHIPS OF THE TURKEY AORTA

1966 ◽  
Vol 44 (6) ◽  
pp. 901-907 ◽  
Author(s):  
Elwood W. Speckmann ◽  
Robert K. Ringer
Keyword(s):  
Blood Pressure ◽  
Ascorbic Acid ◽  
Systolic Blood Pressure ◽  
Thoracic Aorta ◽  
Abdominal Aorta ◽  
Volume Change ◽  
Pressure Range ◽  
Pressure Curve ◽  
Blood Pressure Range ◽  
Thoracic And Abdominal

This experiment was an attempt to define the volume–pressure relationships of the untreated turkey aorta and to evaluate the effect on these relationships of treatment with beta-aminopropionitrile (BAPN) and ascorbic acid. Distensibility values (ΔV/ΔP) were calculated for each of three linear segments of the volume–pressure curve for treated and untreated thoracic and abdominal aortas. In general, the distensibility of the thoracic aorta was greater than that of the abdominal aorta. In both aortic segments addition of BAPN to the ration tended to increase, whereas the addition of ascorbic acid tended to decrease distensibility. The volume–pressure curve of the thoracic aorta was sigmoid in nature and demonstrated the greatest distensibility in the normal physiological systolic blood pressure range of the male Broad Breasted Bronze turkey. Both aortic segments exhibited hysteresis and an isobaric volume change upon successive loading. These phenomena decreased in magnitude with successive loadings.

Determination of the elastic modulus of microscale ceramic particles via nanoindentation

2004 ◽  
Vol 19 (8) ◽  
pp. 2437-2447 ◽  
Author(s):  
J.W. Leggoe
Keyword(s):  
Elastic Modulus ◽  
Elastic Moduli ◽  
Aluminum Matrix ◽  
Scalar Particle ◽  
Accurate Estimate ◽  
Flat Punch ◽  
Silicon Carbide Particles ◽  
Material Mismatch ◽  
Particulate Reinforced

Nanoindentation of the reinforcement in a particulate reinforced metal matrix composite (PR MMC) enables direct investigation of reinforcement properties within the finished material. Mismatch between the elastic moduli of the reinforcement and matrix creates a “secondary indentation” effect, whereby the stiffer reinforcement particles themselves “indent” the more compliant matrix. A finite-element investigation was undertaken to quantify the additional penetration arising under secondary indentation for spherical and cylindrical particles. Modification of Sneddon’s equation for a flat punch by a scalar particle shape factor provided an accurate estimate of the additional penetration. The modified equation was combined with the analysis of Field and Swain to extract the particle elastic modulus from results obtained using a spherical indenter under a multiple partial-unloading indentation regime. The resulting methodology was used to determine the elastic moduli of silicon carbide particles and MicralTM microspheres in two aluminum-matrix PR MMCs.

Hypotensive Hemostatis (Permissive Hypotension) for Ruptured Abdominal Aortic Aneurysm: Are We Really in Control?

Vascular ◽  
2007 ◽  
Vol 15 (4) ◽  
pp. 197-200 ◽  
Author(s):  
J. Adam van der Vliet ◽  
Dennis L. van Aalst ◽  
Leo J. Schultze Kool ◽  
Jan J. Wever ◽  
Jan D. Blankensteijn
Keyword(s):  
Blood Pressure ◽  
Abdominal Aortic Aneurysm ◽  
Aortic Aneurysm ◽  
Systolic Blood Pressure ◽  
Pressure Range ◽  
Ruptured Abdominal Aortic Aneurysm ◽  
Permissive Hypotension ◽  
Abdominal Aortic ◽  
Blood Pressure Range ◽  
Aneurysm Repair

The purpose of this study was to investigate whether a protocol for permissive hypotension was feasible for patients admitted with a ruptured abdominal aortic aneurysm (RAAA). It was aimed to limit prehospital intravenous fluid administration to 500 mL and to maintain systolic blood pressure at a range of 50 to 100 mm Hg following admission, using nitrates when indicated. The diagnosis of RAAA was confirmed with sonography, and all patients with uncontrolled hypovolemic shock immediately underwent open aneurysm repair (OAR). In all other cases, computed tomographic (CT) angiography was performed to determine the eligibility for endovascular aneurysm repair (EVAR). From January 1, 2004, to December 31, 2006, 95 patients with a suspected RAAA were admitted. In 77 patients, the diagnosis of RAAA was confirmed. Twenty-eight cases (36%) underwent OAR for uncontrolled hemodynamic instability. Following CT-angiographic evaluation, 25 of the remaining 49 cases were considered unsuitable for EVAR and subsequently underwent OAR. In 24 of 77 cases (31%), the RAAA was treated with EVAR. Preoperative systolic blood pressure recordings in EVAR patients showed median values (± SD) of 98 (± 34.7) mm Hg in the emergency department and 114 (± 26.2) mm Hg in the operating theater. The desired systolic blood pressure range of 50 to 100 mm Hg was reached in 11 of 24 cases (46%). In 13 of 24 cases (54%), a systolic blood pressure higher than 100 mm Hg was recorded for a period longer than 60 minutes. The 30-day mortality was 32 of 77 (42%), with 6 of 24 (25%) in the EVAR group and 26 of 53 (49%) in the OAR group. This is the first published series of RAAA in which a protocol of permissive hypotension has been adopted. The concept appeared to be feasible in the majority of cases. Protocol violations were sparse ( n = 5). Uncontrolled hypotension occurred in 36% (28 of 77) of all patients, and the desired systolic blood pressure range was achieved in 46% (11 of 24) of the EVAR patients.

Effect of norepinephrine on plasma free fatty acids in dogs treated with reserpine

1963 ◽  
Vol 205 (1) ◽  
pp. 57-59 ◽  
Author(s):  
Francois M. Abboud ◽  
Michael G. Wendling ◽  
John W. Eckstein
Keyword(s):  
Blood Pressure ◽  
Fatty Acids ◽  
Free Fatty Acids ◽  
Arterial Blood Pressure ◽  
Pressor Response ◽  
Maximal Increase ◽  
Arterial Blood ◽  
Anesthetized Dogs ◽  
Plasma Ffa

Some adrenergic blocking drugs reduce the mobilization of free fatty acids (FFA) in response to administration of catecholamines. The present experiments were done to see if potentiation of the pressor effect of norepinephrine by reserpine is accompanied by a greater increase in plasma FFA. Norepinephrine was infused intravenously into 16 anesthetized dogs. Eight of them had been treated with reserpine, 0.25 mg/kg daily, intraperitoneally for 2 days; the others were not treated. Arterial blood samples were drawn before, during, and after norepinephrine for determination of plasma FFA concentrations. Systemic arterial blood pressure was measured continuously. In the treated animals the maximal increase in arterial blood pressure as well as the progressive increments in FFA concentration were greater than in the untreated dogs. The experiments indicate that potentiation of the pressor response to norepinephrine after reserpine is accompanied by a greater FFA response.

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