scholarly journals Is the RealIn VivoNitric Oxide Concentration Pico or Nano Molar? Influence of Electrode Size on Unstirred Layers and NO Consumption

2013 ◽  
Vol 20 (1) ◽  
pp. 30-41 ◽  
Author(s):  
H. Glenn Bohlen
Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1475
Author(s):  
Masahiro Okamoto ◽  
Kazuya Murao

With the spread of devices equipped with touch panels, such as smartphones, tablets, and laptops, the opportunity for users to perform touch interaction has increased. In this paper, we constructed a device that generates multi-touch interactions to realize high-speed, continuous, or hands-free touch input on a touch panel. The proposed device consists of an electrode sheet printed with multiple electrodes using conductive ink and a voltage control board, and generates eight multi-touch interactions: tap, double-tap, long-press, press-and-tap, swipe, pinch-in, pinch-out, and rotation, by changing the capacitance of the touch panel in time and space. In preliminary experiments, we investigated the appropriate electrode size and spacing for generating multi-touch interactions, and then implemented the device. From the evaluation experiments, it was confirmed that the proposed device can generate multi-touch interactions with high accuracy. As a result, tap, press-and-tap, swipe, pinch-in, pinch-out, and rotation can be generated with a success rate of 100%. It was confirmed that all the multi-touch interactions evaluated by the proposed device could be generated with high accuracy and acceptable speed.


2021 ◽  
Vol 1874 (1) ◽  
pp. 012077
Author(s):  
Suzanna Ridzuan Aw ◽  
Ruzairi Abdul Rahim ◽  
Fazlul Rahman Mohd Yunus ◽  
Mohd Hafiz Fazalul Rahiman ◽  
Yasmin Abdul Wahab ◽  
...  

Author(s):  
Bahareh Abdi ◽  
Mathijs S. van Schie ◽  
Natasja M.S. de Groot ◽  
Richard C. Hendriks

2003 ◽  
Vol 67 (6) ◽  
pp. 585-590 ◽  
Author(s):  
Jonathan B. Hanson ◽  
Paul T. Russell ◽  
Andy T.A. Chung ◽  
Claire S. Kaura ◽  
Samantha H. Kaura ◽  
...  

1992 ◽  
Vol 12 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Marleen J. Verhaegen ◽  
Michael M. Todd ◽  
David S. Warner ◽  
Bruce James ◽  
Julie B. Weeks

Cerebral blood flow was measured by the H2 clearance method 30 and 60 min after the implantation of 300, 250, 125, or 50 μm diameter platinum–iridium electrodes 2 mm deep into the right parietal cortex of normothermic, normocarbic halothane-anesthetized rats. Another group of animals had 50 μm electrodes inserted 1 mm. In all animals, the presence or absence of a wave of spreading depression (SD) was noted at the time of implantation, with recordings made with glass micropipettes. H2 flow values were compared with those measured in gray matter from the same anatomical region (but from different rats), using [3H]nicotine. The incidence of SD ranged from 60% following insertion of 300 μm electrodes to 0% with 50 μm electrodes. H2 clearance flows also varied with electrode size, from 77 ± 21 ml 100 g−1 min−1 (mean ± standard deviation) with 300 μm electrodes to 110 ± 31 and 111 ± 16 ml 100 g−1 min−1 with 125 and 50 μm electrodes, respectively (insertion depth of 2 mm). A CBF value of 155 ± 60 ml 100 g−1 min−1 was obtained with 50 μm electrodes inserted only 1 mm. Cortical gray matter blood flow measured with [3H]nicotine was 154 ± 35 ml 100 g−1 min−1. When the role of SD in subsequent flow measurements was examined, there was a gradual increase in CBF between 30 and 60 min after electrode insertion in those animals with SD, while no such change was seen in rats without SD. These results indicate that the choice of electrode size and implantation depth influences the measurement of CBF by H2 clearance. CBF values equivalent to those obtained with isotopic techniques can be acutely obtained with small (50 μm diameter) electrodes inserted 1 mm into the cortex. While the occurrence of SD does influence CBF in the period immediately after implantation, a relationship between electrode size and measured flow is present that is independent of SD.


2008 ◽  
Vol 294 (4) ◽  
pp. C1079-C1087 ◽  
Author(s):  
Mary A. Robinson ◽  
James E. Baumgardner ◽  
Virginia P. Good ◽  
Cynthia M. Otto

Nitric oxide (NO) production by inducible NO synthase (iNOS) is dependent on O2 availability. The duration and degree of hypoxia that limit NO production are poorly defined in cultured cells. To investigate short-term O2-mediated regulation of NO production, we used a novel forced convection cell culture system to rapidly (response time of 1.6 s) and accurately (±1 Torr) deliver specific O2 tensions (from <1 to 157 Torr) directly to a monolayer of LPS- and IFNγ-stimulated RAW 264.7 cells while simultaneously measuring NO production via an electrochemical probe. Decreased O2 availability rapidly (≤30 s) and reversibly decreased NO production with an apparent KmO2 of 22 (SD 6) Torr (31 μM) and a Vmax of 4.9 (SD 0.4) nmol·min−1·10−6 cells. To explore potential mechanisms of decreased NO production during hypoxia, we investigated O2-dependent changes in iNOS protein concentration, iNOS dimerization, and cellular NO consumption. iNOS protein concentration was not affected ( P = 0.895). iNOS dimerization appeared to be biphasic [6 Torr ( P = 0.008) and 157 Torr ( P = 0.258) >36 Torr], but it did not predict NO production. NO consumption was minimal at high O2 and NO tensions and negligible at low O2 and NO tensions. These results are consistent with O2 substrate limitation as a regulatory mechanism during brief hypoxic exposure. The rapid and reversible effects of physiological and pathophysiological O2 tensions suggest that O2 tension has the potential to regulate NO production in vivo.


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