scholarly journals Novel method for clarifying faster interstitial flow in the intimal side of the aorta under intraluminal pressurization

2021 ◽  
Author(s):  
Wataru Fukui ◽  
Yoshihiro Ujihara ◽  
Masanori Nakamura ◽  
Shukei Sugita
Keyword(s):  
Flow Velocity ◽  
Mechanical Stress ◽  
Ex Vivo ◽  
Time Lapse ◽  
Fluorescent Dye ◽  
Intraluminal Pressure ◽  
Interstitial Flow ◽  
Advection Diffusion Equation ◽  
Novel Method ◽  
The One

Hypertension causes aortic thickening, especially on the intimal side. Although the production of the extracellular matrix is observed, the type of mechanical stress that produces this response remains unclear. In this study, we hypothesize that the interstitial flow causes the thickening. To validate this claim, we proposed a novel method to measure the velocity distribution in the radial direction in the aorta, which has been unclear. A fluorescent dye was introduced in the lumen of the mouse thoracic aorta ex vivo, intraluminal pressure was applied, and a time-lapse image in the radial-circumferential plane was acquired under a two-photon microscope. The flow of the fluorescent dye from the intimal to the adventitial sides in the aorta was successfully observed. The acquired image was converted to a radial-time image (i.e., kymograph), and the flow velocity was quantified by applying the one-dimensional advection-diffusion equation to the fluorescent images. The results revealed a higher interstitial flow velocity in the aortic walls under higher intraluminal pressure and a higher velocity on the more intimal side. Thus, the interstitial flow is a candidate for the mechanical stress causing hyperplasia of the aorta under hypertension.

A Novel Method for the Rapid Purification of Human and Rat Fibrin(OGEN) Degradation Products in High Yields

1979 ◽  
Author(s):  
W. Nieuwenhuizen ◽  
I. A. M. van Ruijven-Vermeer ◽  
F. Haverkate ◽  
G. Timan
Keyword(s):  
Degradation Products ◽  
Complete Separation ◽  
Purification Method ◽  
Amino Terminal ◽  
Novel Method ◽  
Rapid Purification ◽  
The One ◽  
High Yields ◽  
Size Heterogeneity ◽  
D Dimer

A novel method will be described for the preparation and purification of fibrin(ogen) degradation products in high yields. The high yields are due to two factors. on the one hand an improved preparation method in which the size heterogeneity of the degradation products D is strongly reduced by plasmin digestion at well-controlled calcium concentrations. At calcium concentrations of 2mM exclusively D fragments, M.W.= 93-000 (Dcate) were formed; in the presence of 1OmM EGTA only fragments M.W.= 80.000 (D EGTA) were formed as described. on the other hand a new purification method, which includes Sephadex G-200 filtration to purify the D:E complexes and separation of the D and E fragments by a 16 hrs. preparative isoelectric focussing. The latter step gives a complete separation of D (fragments) (pH = 6.5) and E fragments (at pH = 4.5) without any overlap, thus allowing a nearly 100% recovery in this step. The overall recoveries are around 75% of the theoretical values. These recoveries are superior to those of existing procedures. Moreover the conditions of this purification procedure are very mild and probably do not affect the native configuration of the products. Amino-terminal amino acids of human Dcate, D EGTA and D-dimer are identical i.e. val, asx and ser. in the ratgly, asx and ser were found. E 1% for rat Dcate=17-8 for rat D EGTA=16.2 and for rat D- dimer=l8.3. for the corresponding human fragments, these values were all 20.0 ± 0.2.

Near-Perfect Reconstruction Oversampled Nonuniform Cosine-Modulated Filter Banks Based on Frequency Warping and Subband Merging

2012 ◽  
Vol 58 (2) ◽  
pp. 177-192 ◽  
Author(s):  
Marek Parfieniuk ◽  
Alexander Petrovsky
Keyword(s):  
Group Delay ◽  
Filter Banks ◽  
Main Idea ◽  
Perceptual Processing ◽  
Perfect Reconstruction ◽  
Frequency Warping ◽  
Small Loss ◽  
Novel Method ◽  
The One ◽  
Near Perfect Reconstruction

Near-Perfect Reconstruction Oversampled Nonuniform Cosine-Modulated Filter Banks Based on Frequency Warping and Subband MergingA novel method for designing near-perfect reconstruction oversampled nonuniform cosine-modulated filter banks is proposed, which combines frequency warping and subband merging, and thus offers more flexibility than known techniques. On the one hand, desirable frequency partitionings can be better approximated. On the other hand, at the price of only a small loss in partitioning accuracy, both warping strength and number of channels before merging can be adjusted so as to minimize the computational complexity of a system. In particular, the coefficient of the function behind warping can be constrained to be a negative integer power of two, so that multiplications related to allpass filtering can be replaced with more efficient binary shifts. The main idea is accompanied by some contributions to the theory of warped filter banks. Namely, group delay equalization is thoroughly investigated, and it is shown how to avoid significant aliasing by channel oversampling. Our research revolves around filter banks for perceptual processing of sound, which are required to approximate the psychoacoustic scales well and need not guarantee perfect reconstruction.

scholarly journals A novel approach to the computation of one-loop three- and four-point functions: I. The real mass case

2019 ◽  
Vol 2019 (11) ◽  
Author(s):  
J Ph Guillet ◽  
E Pilon ◽  
Y Shimizu ◽  
M S Zidi
Keyword(s):  
Building Blocks ◽  
The Real ◽  
Alternative Method ◽  
Novel Approach ◽  
Reduction Methods ◽  
Real Mass ◽  
Novel Method ◽  
Algebraic Reduction ◽  
The One ◽  
Mass Case

Abstract This article is the first of a series of three presenting an alternative method of computing the one-loop scalar integrals. This novel method enjoys a couple of interesting features as compared with the method closely following ’t Hooft and Veltman adopted previously. It directly proceeds in terms of the quantities driving algebraic reduction methods. It applies to the three-point functions and, in a similar way, to the four-point functions. It also extends to complex masses without much complication. Lastly, it extends to kinematics more general than that of the physical, e.g., collider processes relevant at one loop. This last feature may be useful when considering the application of this method beyond one loop using generalized one-loop integrals as building blocks.

scholarly journals Posturography with head movements in the assessment of balance in chronic unilateral vestibular lesions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Magdalena Janc ◽  
Mariola Sliwinska-Kowalska ◽  
Piotr Politanski ◽  
Marek Kaminski ◽  
Magdalena Jozefowicz-Korczynska ◽  
...  
Keyword(s):  
High Reliability ◽  
Low Frequency ◽  
Random Order ◽  
Head Movements ◽  
Canal Paresis ◽  
Eyes Closed ◽  
Static Posturography ◽  
Unstable Surface ◽  
Novel Method ◽  
The One

AbstractThe aim of our study was to validate the method of head-shake static posturography (HS-posturography) in healthy individuals and to establish the value of this novel method in the diagnostics of patients with unilateral vestibular lesion (UV). The study included 202 participants divided into two groups, one consisting of 133 patients with canal paresis CP > 19% and one of 69 healthy subjects. Participant was tested according to the standard protocol of static posturography (SP), and with head movements of 0.3 Hz (HS 40), 0.6 Hz (HS 70) in random order controlled by a metronome. HS-posturography revealed a similar repeatability and internal consistency as the standard posturography. In patients with UV, 4th condition revealed higher sensitivity (74%) and specificity (71%) in HS 40 than in the standard posturography (67%, 65% respectively) and HS 70 (54%, 70% respectively). Static posturography and HS- posturography revealed a high reliability of the testing method. The head movements added to static posturography improve the sensitivity and specificity of the method in group with vestibular impairment. The most important test for that purpose seems to be the one on unstable surface with the eyes closed, with low frequency of head movements.

A Novel Method for the One-Pot Three-Component Synthesis of 2,3-Dihydroquinazolin-4(1H)-ones.

ChemInform ◽  
2005 ◽  
Vol 36 (41) ◽  
Author(s):  
Peyman Salehi ◽  
Minoo Dabiri ◽  
Mohammad Ali Zolfigol ◽  
Mostafa Baghbanzadeh
Keyword(s):  
One Pot ◽  
Novel Method ◽  
The One

A Novel Method for Ex-Vivo Latex Angiography of the Mouse Brain

2021 ◽  
pp. 109342
Author(s):  
Keyan Peterson ◽  
Stephanie Coffman ◽  
Stacey Wolfe ◽  
Zhidan Xiang
Keyword(s):  
Mouse Brain ◽  
Ex Vivo ◽  
Novel Method

Luminally released serotonin stimulates colonic motility and accelerates colonic transit in rats

2007 ◽  
Vol 293 (1) ◽  
pp. R64-R69 ◽  
Author(s):  
Kiyoshi Tsukamoto ◽  
Hajime Ariga ◽  
Chris Mantyh ◽  
Theodore N. Pappas ◽  
Hidenori Yanagi ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Colonic Motility ◽  
Physiological Role ◽  
Distal Colon ◽  
Proximal Colon ◽  
Colonic Transit ◽  
Intraluminal Pressure ◽  
Ex Vivo Model ◽  
Colon Tissue ◽  
Ec Cells

Enterochromaffin (EC) cells of the epithelial cells release 5-HT into the lumen, as well as basolateral border. However, the physiological role of released 5-HT into the lumen is poorly understood. Concentrations of 5-HT in the colonic mucosa, colonic lumen, and feces were measured by HPLC in rats. To investigate whether intraluminal 5-HT accelerates colonic transit, 5-HT and 51Cr were administered into the lumen of the proximal colon, and colonic transit was measured. To investigate whether 5-HT is released into the lumen, we used an ex vivo model of isolated vascularly and luminally perfused rat proximal colon. To investigate whether luminal 5-HT is involved in regulating stress-induced colonic motility, the distal colonic motility was recorded under the stress loading, and a 5-HT3 receptor antagonist (ondansetron, 10−6 M, 0.5 ml) was administered intraluminally of the distal colon. Tissue content of 5-HT in the proximal colon (15.2 ± 4.3 ng/mg wet tissue) was significantly higher than that in the distal colon (3.3 ± 0.7 ng/mg wet tissue), while fecal content and luminal concentration of 5-HT was almost the same between the proximal and distal colon. Luminal administration of 5-HT (10−6–10−5 M) significantly accelerated colonic transit. Elevation of intraluminal pressure by 10 cmH2O significantly increased the luminal concentration of 5-HT but not the vascular concentration of 5-HT. Stress-induced stimulation of the distal colonic motility was significantly attenuated by the luminal administration of ondansetron. These results suggest that luminally released 5-HT from EC cells plays an important role in regulating colonic motility in rats.

Ex vivo time-lapse confocal imaging of the mouse embryo aorta

2011 ◽  
Vol 6 (11) ◽  
pp. 1792-1805 ◽  
Author(s):  
Jean-Charles Boisset ◽  
Charlotte Andrieu-Soler ◽  
Wiggert A van Cappellen ◽  
Thomas Clapes ◽  
Catherine Robin
Keyword(s):  
Mouse Embryo ◽  
Ex Vivo ◽  
Time Lapse ◽  
Confocal Imaging

A Novel Method for Determination of Inorganic Polyphosphates Using the Fluorescent Dye Fura-2

1997 ◽  
Vol 246 (2) ◽  
pp. 176-184 ◽  
Author(s):  
Bernd Lorenz ◽  
Jessica Münkner ◽  
Marco P. Oliveira ◽  
José M. Leitão ◽  
Werner E.G. Müller ◽  
...  
Keyword(s):  
Fluorescent Dye ◽  
Inorganic Polyphosphates ◽  
Fura 2 ◽  
Novel Method

Abstract 235: Ischemia-Reperfusion Injury Decreases Myocardial Hydration Potential Without Changing Flow Resistance in the Interstitial Matrix

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Maria P McGee ◽  
Michael Morykwas ◽  
James Jordan ◽  
Louis Argenta
Keyword(s):  
At Risk ◽  
Flow Resistance ◽  
Ischemia Reperfusion Injury ◽  
Ex Vivo ◽  
Ischemia Reperfusion ◽  
P Value ◽  
Mechanical Forces ◽  
Interstitial Flow ◽  
Elastic Recoil ◽  
Fluid Accumulation

Interstitial edema is an early response to myocardial ischemia, leading to fibrosis and remodeling in several heart failure conditions. We aimed to clarify whether osmotic, frictional, or mechanical forces drive fluid accumulation. Equilibrium and dynamic interstitial hydration parameters were determined, compared, and analyzed using osmotic stress approaches in explants from ischemic and nonischemic myocardial regions of pig heart. They were isolated after injury induced by ligating 3-4 branches of the left anterior descending coronary artery, for 85 min followed by 3 hours’ reperfusion. Their volume changed (Δ V max ) linearly with colloidosmotic pressure in both ischemic and nonischemic areas, yielding interstitial compliance values of 1.04 ± 0.09 and 1.08 ± 0.05 µl/g/ mmHg , which do not differ significantly, and hydration potentials from the abscissa intercepts at Δ V max = 0, of -121.4 ± 28 and -14.7 ± 7.6 mmHg, which do (mean ± SE, n = 5 , P-value = 0.001). These hydration potential differences manifest ex-vivo influx rates 8.5 ± 2.7- fold slower in ischemic than nonischemic myocardium. Surprisingly, interstitial flow resistance values derived from net-flow rates at an imposed pressure difference of 216 mmHg were 0.23 ± 0.08 and 0.19 ± 0.01 µl -1 . g. min and did not differ significantly between the areas. The similarity in interstitial compliance and fluid resistance indicates that the more negative hydration potential and faster efflux rates in at-risk regions after reperfusion are due to increased hydrostatic pressure rather than decreased osmotic or frictional forces. Tissue distends due to interstitial fluid accumulation against matrix mechanical forces, including elastic recoil of the collagen elastin mesh and fibroblast action, consistent with impaired drainage and persistent diastolic-like conditions during reperfusion of at-risk areas in vivo . These results indicate changes in pressure gradient magnitude and may have clinical and therapeutic implications; for example, reversal of paracrine interstitial flows during early remodeling

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