scholarly journals Strategies for the deposition of LaFeO3 photocathodes: improving the photocurrent with a polymer template

2020 ◽  
Vol 4 (2) ◽  
pp. 884-894 ◽  
Author(s):  
Emma Freeman ◽  
Santosh Kumar ◽  
Veronica Celorrio ◽  
Min Su Park ◽  
Jong Hak Kim ◽  
...  

LaFeO3 photocathodes with high porosity and uniformity are developed through polymer templating with Triton X-100, improving charge separation and boosting photocurrents achieved.

1994 ◽  
Vol 223 (5-6) ◽  
pp. 511-516 ◽  
Author(s):  
Dirk M. Guldi ◽  
Robert E. Huie ◽  
Pedatsur Neta ◽  
Hartmut Hungerbühler ◽  
Klaus-Dieter Asmus
Keyword(s):  

Author(s):  
S.W. French ◽  
N.C. Benson ◽  
C. Davis-Scibienski

Previous SEM studies of liver cytoskeletal elements have encountered technical difficulties such as variable metal coating and heat damage which occurs during metal deposition. The majority of studies involving evaluation of the cell cytoskeleton have been limited to cells which could be isolated, maintained in culture as a monolayer and thus easily extracted. Detergent extraction of excised tissue by immersion has often been unsatisfactory beyond the depth of several cells. These disadvantages have been avoided in the present study. Whole C3H mouse livers were perfused in situ with 0.5% Triton X-100 in a modified Jahn's buffer including protease inhibitors. Perfusion was continued for 1 to 2 hours at ambient temperature. The liver was then perfused with a 2% buffered gluteraldehyde solution. Liver samples including spontaneous tumors were then maintained in buffered gluteraldehyde for 2 hours. Samples were processed for SEM and TEM using the modified thicarbohydrazide procedure of Malich and Wilson, cryofractured, and critical point dried (CPD). Some samples were mechanically fractured after CPD.


Author(s):  
H. M. Kerch ◽  
R. A. Gerhardt

Highly porous ceramics are employed in a variety of engineering applications due to their unique mechanical, optical, and electrical characteristics. In order to achieve proper design and function, information about the pore structure must be obtained. Parameters of importance include pore size, pore volume, and size distribution, as well as pore texture and geometry. A quantitative determination of these features for high porosity materials by a microscopic technique is usually not done because artifacts introduced by either the sample preparation method or the image forming process of the microscope make interpretation difficult.Scanning electron microscopy for both fractured and polished surfaces has been utilized extensively for examining pore structures. However, there is uncertainty in distinguishing between topography and pores for the fractured specimen and sample pullout obscures the true morphology for samples that are polished. In addition, very small pores (nm range) cannot be resolved in the S.E.M. On the other hand, T.E.M. has better resolution but the specimen preparation methods involved such as powder dispersion, ion milling, and chemical etching may incur problems ranging from preferential widening of pores to partial or complete destruction of the pore network.


1990 ◽  
Vol 63 (02) ◽  
pp. 303-311
Author(s):  
Tone Børsum

SummaryHuman endothelial cells isolated from umbilical cordswere solubilized in Triton X-100 and examined by crossedimmunoelec-trophoresis using rabbit antiserum against endothelial cells. Endogenous labelling of the endothelialcell proteins with 14Cmannose followed by crossed immunoelectrophoresis and autoradiography revealed about 10 immunoprecipitates. Four of these endothelial cell glycoproteins were labelled by lactoperoxidase catalyzed iodination and thus were surface located. Three of the surface located glycoproteins showed reduced electrophoretic mobility after incubation of the endothelial cells with neuraminidase and were therefore sialoglycoproteins. Amphiphilicity of endothelial cell glycoproteins was studied by crossed hydrophobic interaction immunoelectrophoresis with phenyl-Sepharose in the intermediate gel. Amphiphilic proteins also show increasing electrophoretic migration velocity with decreasing concentration of Triton X-100 in the first dimension gels. Five of the endothelial cell glycoproteins were shown to be amphiphilic using these two techniques.Two monoclonal antibodies against the platelet glycoprotein complex Ilb-IIIa and glycoprotein IlIa, respectively, reacted with the same precipitate of endothelial cells. When a polyclonal antibody against the platelet glycoprotein complex Ilb-IIIa was incorporated into the intermediate gel the position of two endothelial cell precipitates were lowered. One of these was a sialoglycoprotein.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 457-464
Author(s):  
Paul C. French ◽  
Jan J. Sixma ◽  
Holm Holmsen

SummaryAdenine uptake into isolated platelet membranes had about the same Km (151 ± 21 • 9 nM) as uptake into intact cells (159 ± 21 nM) and was also competitively inhibited by papaverine and hypoxanthine. No uptake occurred at 0° and accumulated adenine was converted to AMP. AMP was not firmly bound to protein as judged by chromatography of triton X-100 solubilized membranes on Sephadex G25. The pH optimum for adenine uptake was at pH 5-5. Exogenous 5-phosphoribosyl-l-pyrophos- phate strongly stimulated uptake. These data may be explained by uptake of adenine by facilitated diffusion followed by conversion to AMP by adenine phosphoribosyltransferase but group translocation cannot be entirely excluded.


1992 ◽  
Vol 67 (02) ◽  
pp. 252-257 ◽  
Author(s):  
Anne M Aakhus ◽  
J Michael Wilkinson ◽  
Nils Olav Solum

SummaryActin-binding protein (ABP) is degraded into fragments of 190 and 90 kDa by calpain. A monoclonal antibody (MAb TI10) against the 90 kDa fragment of ABP coprecipitated with the glycoprotein lb (GP lb) peak observed on crossed immunoelectrophoresis of Triton X-100 extracts of platelets prepared without calpain inhibitors. MAb PM6/317 against the 190 kDa fragment was not coprecipitated with the GP lb peak under such conditions. The 90 kDa fragment was adsorbed on protein A agarose from extracts that had been preincubated with antibodies to GP lb. This supports the idea that the GP Ib-ABP interaction resides in the 90 kDa region of ABP. GP lb was sedimented with the Triton-insoluble actin filaments in trace amounts only, and only after high speed centrifugation (100,000 × g, 3 h). Both the 190 kDa and the 90 kDa fragments of ABP were sedimented with the Triton-insoluble actin filaments.


1984 ◽  
Vol 51 (01) ◽  
pp. 119-124 ◽  
Author(s):  
M B Zucker ◽  
N C Masiello

SummaryMacIntyre et al. showed that over 1 mM dithiothreitol (DTT) aggregates blood platelets in the presence of fibrinogen; aggregation is not inhibited by prostaglandin E1. We confirmed their data and found that 70 mM 2-mercaptoethanol was also active. DTT- induced aggregation was not associated with platelet shape change or secretion of dense granule contents, was not inhibited by tetracaine or metabolic inhibitors, was prevented at pH 6.5, and prevented, reversed, or arrested by EDTA, depending on when the EDTA was added. DTT did not cause aggregation of thrombasthenic, EDTA-treated, or cold (0° C) platelets, which also failed to aggregate with ADP. Platelets stimulated with DTT bound 125I-labeled fibrinogen. Thus DTT appears to “expose” the fibrinogen receptors. SDS gel electrophoresis of platelet fractions prepared by use of Triton X-114 showed that aggregating concentrations of DTT reduced proteins of apparent Mr 69,000 and 52,000 (probably platelet albumin) and, to a variable extent, glycoproteins Ib, IIb and III. Exposure of unlabeled or 125I- labeled platelets to ADP had no discernible effect on the electrophoretic patterns.


1983 ◽  
Vol 50 (04) ◽  
pp. 848-851 ◽  
Author(s):  
Marjorie B Zucker ◽  
David Varon ◽  
Nicholas C Masiello ◽  
Simon Karpatkin

SummaryPlatelets deprived of calcium and incubated at 37° C for 10 min lose their ability to bind fibrinogen or aggregate with ADP when adequate concentrations of calcium are restored. Since the calcium complex of glycoproteins (GP) IIb and IIIa is the presumed receptor for fibrinogen, it seemed appropriate to examine the behavior of these glycoproteins in incubated non-aggregable platelets. No differences were noted in the electrophoretic pattern of nonaggregable EDTA-treated and aggregable control CaEDTA-treated platelets when SDS gels of Triton X- 114 fractions were stained with silver. GP IIb and IIIa were extracted from either nonaggregable EDTA-treated platelets or aggregable control platelets with calcium-Tris-Triton buffer and subjected to sucrose density gradient centrifugation or crossed immunoelectrophoresis. With both types of platelets, these glycoproteins formed a complex in the presence of calcium. If the glycoproteins were extracted with EDTA-Tris-Triton buffer, or if Triton-solubilized platelet membranes were incubated with EGTA at 37° C for 30 min, GP IIb and IIIa were unable to form a complex in the presence of calcium. We conclude that inability of extracted GP IIb and IIIa to combine in the presence of calcium is not responsible for the irreversible loss of aggregability that occurs when whole platelets are incubated with EDTA at 37° C.


TAPPI Journal ◽  
2018 ◽  
Vol 17 (03) ◽  
pp. 145-153 ◽  
Author(s):  
Chengua Yu ◽  
Feng Wang ◽  
Shiyu Fu ◽  
Lucian Lucia

A very low-density oil-absorbing hydrophobic material was fabricated from cellulose nanofiber aerogels–coated silane substances. Nanocellulose aerogels (NCA) superabsorbents were prepared by freeze drying cellulose nanofibril dispersions at 0.2%, 0.5%, 0.8%, 1.0%, and 1.5% w/w. The NCA were hydrophobically modified with methyltrimethoxysilane. The surface morphology and wettability were characterized by scanning electron microscopy and static contact angle. The aerogels displayed an ultralow density (2.0–16.7 mg·cm-3), high porosity (99.9%–98.9%), and superhydrophobicity as evidenced by the contact angle of ~150° that enabled the aerogels to effectively absorb oil from an oil/water mixture. The absorption capacities of hydrophobic nanocellulose aerogels for waste engine oil and olive oil could be up to 140 g·g-1 and 179.1 g·g-1, respectively.


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