https://yunus.hacettepe.edu.tr/~damlacetin/kmu407/index_dosyalar/4.%20makale.pdf

Biodegradable polymers as biomaterials

The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

American Society for Testing and Materials

American Heart Association Council on cardiovascular nursing.

Circadian rhythms modulate nearly every mammalian physiological process. Chronic disruption of circadian timing in shift work or during chronic jet lag in animal models leads to a higher risk of several pathologies. Many of these conditions in both shift workers and experimental models share the common risk factor of inflammation. In this study, we show that experimentally induced circadian disruption altered innate immune responses. Endotoxemic shock induced by LPS was magnified, leading to hypothermia and death after four consecutive weekly 6-h phase advances of the light/dark schedule, with 89% mortality compared with 21% in unshifted control mice. This may be due to a heightened release of proinflammatory cytokines in response to LPS treatment in shifted animals. Isolated peritoneal macrophages harvested from shifted mice exhibited a similarly heightened response to LPS in vitro, indicating that these cells are a target for jet lag. Sleep deprivation and stress are known to alter immune function and are potential mediators of the effects we describe. However, polysomnographic recording in mice exposed to the shifting schedule revealed no sleep loss, and stress measures were not altered in shifted mice. In contrast, we observed altered or abolished rhythms in the expression of clock genes in the central clock, liver, thymus, and peritoneal macrophages in mice after chronic jet lag. We conclude that circadian disruption, but not sleep loss or stress, are associated with jet lag-related dysregulation of the innate immune system. Such immune changes might be a common mechanism for the myriad negative health effects of shift work.

Dysregulation of Inflammatory Responses by Chronic Circadian Disruption

http://www.tara.tcd.ie/bitstream/handle/2262/68354/CurtisFINAL.pdf;sequence=1

Circadian Clock Proteins and Immunity

Various extracorporeal circulation devices require a real time thrombus detection system. This paper presents a study toward the establishment of real-time thrombus detection by measuring the electrical properties of blood. We conducted experiments on static bovine blood samples and determined the change in relative permittivity of the samples by changing the size and red blood cell (RBC) concentration of the thrombus in each sample. Results show that the relative permittivity increases linearly with increases in the number of RBCs that form the thrombus. Similarly, permittivity also increases linearly with increases in the volume of the blood that forms the thrombus. These results are consistent with the numerical simulations. However, we found the linear relationship to be dependent on the AC frequency of the applied voltage. We compare and explain this dependency on the basis of earlier studies.

Analysis of the influence of volume and red blood cell concentration of a thrombus on the permittivity of blood

Measurements of dynamic tube deformation were conducted using a laser displacement meter supported on a pulse motor stage together with an electromagnetic flow meter. The results have clarified that fluid velocity approaches pressure wave velocity, which is estimated from the tube law, at the throat around the stability boundaries and that a supercritical flow and subcritical flow occur alternately during oscillations. By contrast, a linearized lumped parameter model has been developed

Relationship of Pressure Wave Velocity to Self-Excited Oscillation of Collapsible Tube Flow

We are developing a monopivot centrifugal pump for circulatory assist for a period of more than 2 weeks. The impeller is supported by a pivot bearing at one end and by a passive magnetic bearing at the other. The pivot undergoes concentrated exposure to the phenomena of wear, hemolysis, and thrombus formation. The pivot durability, especially regarding the combination of male/female pivot radii, was examined through rotating wear tests and animal tests. As a result, combinations of similar radii for the male/female pivots were found to provide improved pump durability. In the extreme case, the no-gap combination would result in no thrombus formation.

Pivot wear of a centrifugal blood pump developed for circulatory assist

In this paper, we describe a new boundary acoustic wave structure employing multilayered metal electrodes with a high-density metal and a low-density metal. By using this structure, such as Pt/Al/Pt, the electromechanical coupling coefficient (k2) and temperature coefficient of frequency (TCF) of the boundary acoustic wave can be changed. We theoretically studied the dependence of the energy distribution of the boundary wave on the position of the total electrode gravity center when the electrode layer structure is changed. It was experimentally confirmed that k2 and TCF can be changed simultaneously. By using this structure, we developed a novel filter with good electrical characteristics, and a very small variation of the filter characteristic with temperature (almost zero TCF) was successfully realized.

Takashi Yamane

Papers

Analysis of the influence of volume and red blood cell concentration of a thrombus on the permittivity of blood

Relationship of Pressure Wave Velocity to Self-Excited Oscillation of Collapsible Tube Flow

Pivot wear of a centrifugal blood pump developed for circulatory assist

Improvement of Temperature Characteristics of Boundary Acoustic Wave Resonators Using Multilayered Electrodes

Design of an axial-type self-bearing motor for small axial pump