Estimation of the dissociation constant for unreacted silanol groups on the surface of ODS-silica from the relationship between ph and electroosmotic flow velocity in capillary electrochromatography

1995 ◽  
Vol 7 (1) ◽  
pp. 59-64 ◽  
Author(s):  
Shinya Kitagawa ◽  
Takao Tsuda
Keyword(s):  
Flow Velocity ◽  
Dissociation Constant ◽  
Capillary Electrochromatography ◽  
Electroosmotic Flow ◽  
Silanol Groups ◽  
The Relationship

The relationship between an aortic isthmus blood flow velocity index and the postnatal neurodevelopmental status of fetuses with placental circulatory insufficiency

2005 ◽  
Vol 192 (2) ◽  
pp. 497-503 ◽  
Author(s):  
Jean-Claude Fouron ◽  
Julie Gosselin ◽  
Marie-Josée Raboisson ◽  
Julie Lamoureux ◽  
Claudine-Amiel Tison ◽  
...  
Keyword(s):  
Blood Flow ◽  
Flow Velocity ◽  
Blood Flow Velocity ◽  
Aortic Isthmus ◽  
Circulatory Insufficiency ◽  
The Relationship

scholarly journals Left atrial appendage orifice area and morphology is closely associated with flow velocity in patients with nonvalvular atrial fibrillation

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lei Chen ◽  
Changjiang Xu ◽  
Wensu Chen ◽  
Chaoqun Zhang
Keyword(s):  
Atrial Fibrillation ◽  
Flow Velocity ◽  
Left Atrial ◽  
Left Atrial Appendage ◽  
Linear Regression Analysis ◽  
Left Ventricular ◽  
Atrial Appendage ◽  
Mechanical Function ◽  
Orifice Area ◽  
The Relationship

Abstract Background Thromboembolic events are the most serious complication of atrial fibrillation (AF), and the left atrial appendage (LAA) is the most important site of thrombosis in patients with AF. During the period of COVID-19, a non-invasive left atrial appendage detection method is particularly important in order to reduce the exposure of the virus. This study used CT three-dimensional reconstruction methods to explore the relationship between LAA morphology, LAA orifice area and its mechanical function in patients with non-valvular atrial fibrillation (NVAF). Methods A total of 81 consecutive patients with NVAF (36 cases of paroxysmal atrial fibrillation and 45 cases of persistent atrial fibrillation) who were planned to undergo catheter radiofrequency ablation were enrolled. All patients were examined by transthoracic echocardiography (TTE), TEE, and computed tomography angiography (CTA) before surgery. The LAA orifice area was obtained according to the images of CTA. According to the left atrial appendage morphology, it was divided into chicken wing type and non-chicken wing type. At the same time, TEE was performed to determine left atrial appendage flow velocity (LAAFV), and the relationship between the left atrial appendage orifice area and LAAFV was analyzed. Results The LAAFV in Non-chicken wing group was lower than that in Chicken wing group (36.2 ± 15.0 cm/s vs. 49.1 ± 22.0 cm/s, p-value < 0.05). In the subgroup analysis, the LAAFV in Non-chicken wing group was lower than that in Chicken wing group in the paroxysmal AF (44.0 ± 14.3 cm/s vs. 60.2 ± 22.8 cm/s, p-value < 0.05). In the persistent AF, similar results were observed (29.7 ± 12.4 cm/s vs. 40.8 ± 17.7 cm/s, p-value < 0.05). The LAAFV in persistent AF group was lower than that in paroxysmal AF group (34.6 ± 15.8 cm/s vs. 49.9 ± 20.0 cm/s, p-value < 0.001). The LAAFV was negatively correlated with left atrial dimension (R = − 0.451, p-value < 0.001), LAA orifice area (R= − 0.438, p-value < 0.001) and left ventricular mass index (LVMI) (R= − 0.624, p-value < 0.001), while it was positively correlated with LVEF (R = 0.271, p-value = 0.014). Multiple linear regression analysis showed that LAA morphology (β = − 0.335, p-value < 0.001), LAA orifice area (β = −  0.185, p-value = 0.033), AF type (β = − 0.167, p-value = 0.043) and LVMI (β = − 0.465, p-value < 0.001) were independent factors of LAAFV. Conclusions The LAA orifice area is closely related to the mechanical function of the LAA in patients with NVAF. The larger LAA orifice area and LVMI, Non-chicken wing LAA and persistent AF are independent predictors of decreased mechanical function of LAA, and these parameters might be helpful for better management of LA thrombosis.

Optimization of resolution of 13 diuretics in CZE by controlling capillary length and electroosmotic flow velocity

1994 ◽  
Vol 6 (6) ◽  
pp. 595-604 ◽  
Author(s):  
Juho Hermanni Jumppanen ◽  
Marja-Liisa Riekkola ◽  
Heikki Haario
Keyword(s):  
Flow Velocity ◽  
Electroosmotic Flow ◽  
Capillary Length

Research on Traffic Flow Velocity Characteristic at Temporary Reversible Lane

2014 ◽  
Vol 505-506 ◽  
pp. 1189-1193
Author(s):  
Yi Cao ◽  
Zhong Yi Zuo ◽  
Hui Zhi Xu
Keyword(s):  
Flow Velocity ◽  
Traffic Flow ◽  
Existing Problems ◽  
Before And After ◽  
Relationship Model ◽  
Velocity Characteristic ◽  
Utilization Ratio ◽  
The Individual ◽  
Lane Utilization ◽  
The Relationship

In order to analyze the existing problems of temporary reversible lane, traffic flow velocity characteristic at the period of direction changing was analyzed. Taking Huangpu road as the investigation object, the traffic flow velocity parameters before and after direction changing were investigated respectively. By the method of mathematical statistics, the individual vehicles velocities and the traffic flow velocity before and after direction changing were compared and analyzed. Using the method of regression analysis, the relationship model between velocity and density of reversible lane was constructed. This paper also discussed the problems of this kind of lane. The research showed that, in terms of traffic flow operation velocity of temporary reversible lane, there is obvious and regular difference between before and after direction changing. There is a certain relationship between the velocity and density. The problem of lower lane utilization ratio of temporary reversible lane usually exists.

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