Silicon micromachining with nanometer-thin boron masking and membrane material

2019 ◽  
Vol 6 (11) ◽  
pp. 116438
Author(s):  
Xingyu Liu ◽  
Joe Italiano ◽  
Robin Scott ◽  
Lis K Nanver
Author(s):  
Robert M. Glaeser ◽  
David W. Deamer

In the investigation of the molecular organization of cell membranes it is often supposed that lipid molecules are arranged in a bimolecular film. X-ray diffraction data obtained in a direction perpendicular to the plane of suitably layered membrane systems have generally been interpreted in accord with such a model of the membrane structure. The present studies were begun in order to determine whether selected area electron diffraction would provide a tool of sufficient sensitivity to permit investigation of the degree of intermolecular order within lipid films. The ultimate objective would then be to apply the method to single fragments of cell membrane material in order to obtain data complementary to the transverse data obtainable by x-ray diffraction.


Author(s):  
B. Monis ◽  
D. Lis ◽  
I. Parlanti ◽  
A. R. Eynard ◽  
M. A. Valentich ◽  
...  

We are gathering evidences which indicate ultrastructural variations and chemical heterogeneity of certain glycocalyces as well as hormone dependence of some of them. Thus, in the lumenal glycocalyx of renal collecting tubules of the guinea-pig granular and filamentous structures were seen (1, fig. 1). By isolation, chemical analysis and cellulose acetate electrophoresis in various buffers of tubular membrane material, glycopeptides and glycosaminoglycans were identified (fig. 2).Guinea-pig and rat transitional epithelium of urinary tract showed a filamentous lumenal glycocalyx demonstrable with ruthenium red (fig. 3) but which only in part stained with concanavalin A. Chemical and electrophoretic data indicated that urothelium contains glycoproteins, glycosaminoglycans and glycolipids.The glycocalyx of the fat globule membrane of milk of several species has a granular appearance as shown by cationic dyes and by concanavalin A (2, 3, fig. 4 and 5). Also, several glycoproteins were isolated and identified on polyacrilamide gel electrophoresis (fig. 6). Glycosaminoglycans and certain glycolipids such as sulfatides were chemically identified in this glycocalyx.


Reproduction ◽  
2000 ◽  
pp. 315-326 ◽  
Author(s):  
MH Stoffel ◽  
AE Friess ◽  
SH Hartmann

In dogs, passive immunity is conferred to fetuses and neonates by the transfer of maternal immunoglobulin G through the placenta during the last trimester of pregnancy and via the mammary gland after parturition, respectively. However, morphological evidence of transplacental transport is still lacking. The aim of the present study was to localize maternal immunoglobulin G in the labyrinthine zone and in the haemophagous zone of the canine placenta by means of immunohistochemistry and immunocytochemistry. In the labyrinthine zone, immunoglobulin G was detected in all the layers of the materno-fetal barrier including the fetal capillaries. Immunoreactivity was particularly prominent in maternal basement membrane material as well as in the syncytiotrophoblast. However, this evidence of transplacental transport of immunoglobulin G originated from a limited number of unevenly distributed maternal vessels only. In the cytotrophoblast of the haemophagous zone, immunoglobulin G was localized to phagolysosomes at various stages but was never detected within fetal vessels. The results indicate that maternal immunoglobulin G is degraded in cytotrophoblast cells of the hemophagous zone and, therefore, that transplacental transport is restricted to a subpopulation of maternal vessels in the labyrinthine zone.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Hiroko Yuzawa ◽  
Yousuke Hirose ◽  
Tomonori Kimura ◽  
Keisuke Shinozaki ◽  
Moe Oguchi ◽  
...  

Abstract Background In continuous renal replacement therapy (CRRT), administration of anticoagulants is necessary for achieving a certain level of filter lifetime. Generally, anticoagulant doses are controlled to keep activated partial thromboplastin time and other indicators within a certain target range, regardless of the membrane materials used for the filter. However, in actual clinical practice, the filter lifetime varies significantly depending on the membrane material used. The objective of this study was to demonstrate that the minimum anticoagulant dose necessary for prolonging the filter lifetime while reducing the risk of hemorrhagic complications varies depending on the type of membrane. Methods In three beagles, hemodiafiltration was performed with hemofilters using polysulfone (PS), polymethylmethacrylate (PMMA), and AN69ST membranes separately. The minimum dose of nafamostat mesylate (NM) that would allow for 6 h of hemodiafiltration (required dose) was investigated for each membrane material. Results The NM doses required for 6 h of hemodiafiltration were 2 mg/kg/h for the PS membrane, 6 mg/kg/h for the PMMA membrane, and 6 mg/kg/h for the AN69ST membrane. Conclusion For hemodiafiltration performed in beagles, the required NM dose varied for each filter membrane material. Using the optimal anticoagulant dose for each membrane material would allow for safer CRRT performance.


2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sudhanshu Tripathi ◽  
Rekha Agarwal ◽  
Rashmi Vashisth ◽  
Devraj Singh

Abstract Capacitive micromachined ultrasonic transducers (CMUTs) are dominant in generating and receiving acoustic signals. CMUT transmission efficiency solely depends upon the membrane material utilized. This work presents the structural examination of receiving and transmitting characteristics of CMUT with divergent membrane materials, namely Silicon (Si), Silicon Nitride ( Si 3 N 4 {\mathrm{Si}_{3}}{\text{N}_{4}} ), Indium Phosphide (InP), Zinc Oxide (ZnO), and Polysilicon (Poly-Si). The analysis includes the membrane deflection, pull-in voltage, output pressure, resonant frequency and capacitance modification with variable DC voltage. It has been found that InP gives the pull-in voltage comparable to Si in the receiving mode and have more transduction efficiency in transmitting mode. Effect of dimensions of CMUT on pull-in voltage and resonant frequency are also discussed. The major contribution lies in the analytical and estimation study of CMUT for appropriate membrane material selection meant for transmission and reception in the field of pressure sensing application.


2021 ◽  
pp. 110569
Author(s):  
Gabriela Vollet Marson ◽  
Débora Tamires Vitor Pereira ◽  
Mariana Teixeira da Costa Machado ◽  
Marco Di Luccio ◽  
Julian Martínez ◽  
...  

2010 ◽  
Vol 362 (1-2) ◽  
pp. 407-416 ◽  
Author(s):  
Wilfredo Yave ◽  
Anna Szymczyk ◽  
Nancy Yave ◽  
Zbigniew Roslaniec

1980 ◽  
Vol 58 (14) ◽  
pp. 1412-1417 ◽  
Author(s):  
Michel Gérin ◽  
James Fresco

The potentiometric behaviour of nitrobenzene solutions of 21 trialkylammonium salts employed as membrane material has been investigated. Deviations from ideal Nernst response curves for chloride, bromide, iodide, and perchlorate sensors were explicable on the basis of partition and hydrolysis of the ion exchangers. Interference coefficients for the anion selective electrochemical sensor tridodecylammonium perchlorate could be related to the ion-exchange constant of the salt.


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