Influence of particle shedding from silicone tubing on antibody stability

2016 ◽  
Vol 70 (5) ◽  
pp. 675-685 ◽  
Author(s):  
Verena Saller ◽  
Constanze Hediger ◽  
Julia Matilainen ◽  
Ulla Grauschopf ◽  
Karoline Bechtold-Peters ◽  
...  
Keyword(s):  
Radiocarbon ◽  
2021 ◽  
pp. 1-17
Author(s):  
Shawn Pedron ◽  
X Xu ◽  
J C Walker ◽  
J C Ferguson ◽  
R G Jespersen ◽  
...  

ABSTRACT We developed a passive sampler for time-integrated collection and radiocarbon (14C) analysis of soil respiration, a major flux in the global C cycle. It consists of a permanent access well that controls the CO2 uptake rate and an exchangeable molecular sieve CO2 trap. We tested how access well dimensions and environmental conditions affect collected CO2, and optimized cleaning procedures to minimize 14CO2 memory. We also deployed two generations of the sampler in Arctic tundra for up to two years, collecting CO2 over periods of 3 days–2 months, while monitoring soil temperature, volumetric water content, and CO2 concentration. The sampler collects CO2 at a rate proportional to the length of a silicone tubing inlet (7–26 µg CO2-C day-1·m Si-1). With constant sampler dimensions in the field, CO2 recovery is best explained by soil temperature. We retrieved 0.1–5.3 mg C from the 1st and 0.6–13 mg C from the 2nd generation samplers, equivalent to uptake rates of 2–215 (n=17) and 10–247 µg CO2-C day-1 (n=20), respectively. The method blank is 8 ± 6 µg C (mean ± sd, n=8), with a radiocarbon content (fraction modern) ranging from 0.5875–0.6013 (n=2). The sampler enables more continuous investigations of soil C emission sources and is suitable for Arctic environments.


Perfusion ◽  
2021 ◽  
pp. 026765912199618
Author(s):  
Mirko Kaluza ◽  
Benjamin May ◽  
Torsten Doenst

Objective: The COVID-19 pandemic requires thinking about alternatives to establish ECMO when often-limited hardware resources are exhausted. Heart-lung-machines may potentially be used for ECMO but contain roller pumps as compared to centrifugal pumps in ECMO-circuits. We here tested roller pumps as rescue pump for ECMO-establishment. Methods: We set up in vitro circuits on roller pumps from C5 heart-lung-machine with 5 l/minutes flow. In two series, we placed either PVC or silicon tubing for an ECMO circuit into the roller pump. We assessed the mechanical stress on the tubing (aiming to run the pump for at least 1 week), measured the temperature increase generated by the friction and assessed flow characteristics and its measurement in simulated situations resembling tube kinking and suction. Results: The roller pumps led to expected and unexpected adverse events. PVC tubing burst between 36 and 78 hours, while silicon tubing lasted for at least 7 days. At 7 days, the silicone tubing showed significant signs of roller pump wear visible on the outside. The inside, however, was free of surface irregularities. Using these tubings in a roller pump led to a remarkable increase in circuit temperature (PVC: +12.0°C, silicone +2.9°C). Kinking or suction on the device caused the expected dramatic flow reduction (as assessed by direct measurement) while the roller pump display continued to show the preset flow. The roller pump is therefore not able to reliably determine the true flow rate. Conclusion: Roller pumps with silicone tubing but not PVC tubing may be used for running ECMO circuits. Silicone tubing may endure the roller pump shear forces for up to 1 week. Thus, repeated tubing repositioning may be a solution. Circuit heating and substantial limitations in flow detection should increase attention if clinical use in situations of crisis is considered.


2017 ◽  
Vol 112 ◽  
pp. 109-118 ◽  
Author(s):  
Verena Saller ◽  
Julia Matilainen ◽  
Christian Rothkopf ◽  
Daniel Serafin ◽  
Karoline Bechtold- Peters ◽  
...  
Keyword(s):  

2009 ◽  
Vol 43 (9) ◽  
pp. 855-865 ◽  
Author(s):  
Michael T. Timko ◽  
Zhenhong Yu ◽  
Jesse Kroll ◽  
John T. Jayne ◽  
Douglas R. Worsnop ◽  
...  

Ophthalmology ◽  
1984 ◽  
Vol 91 (8) ◽  
pp. 963-965 ◽  
Author(s):  
S. Rutherford ◽  
J.S. Crawford ◽  
J.J. Hurwitz

1974 ◽  
Vol 41 (3) ◽  
pp. 367-371 ◽  
Author(s):  
Oscar Sugar ◽  
Orville T. Bailey

✓Silicone tubing (Silastic) used for ventriculoperitoneal shunts induces a fibrous connective tissue sheath around the tubing in children and adults. Two children examined 8 and 3 years after subcutaneous implantation showed a complete tube of dense fibrous connective tissue around the silicone tubing. The reaction was entirely quiescent. These tubes of connective tissue were apparently capable of conveying cerebrospinal fluid for some months after the silicone tubing was disconnected from the pump or pulled out of the abdomen.


Perfusion ◽  
2018 ◽  
Vol 34 (4) ◽  
pp. 297-302
Author(s):  
Anke Dürr ◽  
Andreas Kunert ◽  
Günter Albrecht ◽  
Andreas Liebold ◽  
Markus Hoenicka

Introduction: Pulsatile extracorporeal circulation may improve organ perfusion during cardiac surgery. Some minimally invasive extracorporeal circulation (MiECC) systems allow pulsatile perfusion. The present study investigated the influence of arterial tubing compliance on hemodynamic energy transfer into the patient. Methods: Aortic models with adult human geometry were perfused in a mock circulation. A MiECC system was connected using either high-compliance silicone tubing or standard kit tubing. Energy equivalent pressure (EEP) and surplus hemodynamic energy (SHE) were computed from flow and pressure data. Aortic models with physiological and sub-physiological compliance were tested to assess the influence of the pseudo-patient. Results: Non-pulsatile flow did not generate SHE. SHE during pulsatile flow in the compliant aortic model was significantly higher with kit tubing compared to silicone tubing. Maximum SHE was achieved at 1.6 L/min with kit tubing (7.7% of mean arterial pressure) and with silicone tubing (4.9%). Using the low-compliance aortic model, SHE with kit tubing reached a higher maximum of 14.2% at 1.8 L/min compared to silicone tubing (11.8% at 1.5 L/min). Conclusions: Flexible arterial tubing did not preserve more hemodynamic energy from a pulsatile pump compared to standard kit tubing in a model of adult extracorporeal circulation. The pseudo-patient’s compliance significantly affected the properties of the mock circulation.


2004 ◽  
Vol 278 (2) ◽  
pp. 303-309 ◽  
Author(s):  
Monique W.J den Brok ◽  
Sabien C.van der Schoot ◽  
Bastiaan Nuijen ◽  
Michel J.X Hillebrand ◽  
Jos H Beijnen
Keyword(s):  

1999 ◽  
Vol 24 (6) ◽  
pp. 703-706 ◽  
Author(s):  
J. BRAGA-SILVA

A silicone tube segment was used for repairing the median and ulnar nerves in the forearm. This study includes 26 patients (20 male and six female), with a mean age of 23 years (range, 18-26). Injuries were caused by saw, knife and glass accidents, the latter being most frequent. The mean interval between the injury and repair was 101 days. Fourteen patients had median nerve injuries, eight had ulnar nerve injuries and four had both median and ulnar nerve injuries. The technique was effective in the repair of peripheral nerve injuries with gaps of up to 3 cm, with better results in the ulnar nerves than in the median nerves.


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