Journal articles: 'Substrate contribution'

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Ebersberger, L., and G. Fischerauer. "Influence of the substrate on the overall sensor impedance of planar H2 sensors involving TiO2–SnO2 interfaces." Journal of Sensors and Sensor Systems 4, no. 1 (February 23, 2015): 85–90. http://dx.doi.org/10.5194/jsss-4-85-2015.

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Abstract. To date, very little has been written about the influence of the substrate layer on the overall sensor impedance of single- and multilayer planar sensors (e.g., metal-oxide sensors). However, the substrate is an elementary part of the sensor element. Through the selection of a substrate, the sensor performance can be manipulated. The current contribution reports on the substrate influence in multilayer metal-oxide chemical sensors. Measurements of the impedance are used to discuss the sensor performance with quartz substrates, (laboratory) glass substrates and substrates covered by silicon-dioxide insulating layers. Numerical experiments based on previous measurement results show that inexpensive glass substrates contribute up to 97% to the overall sensor responses. With an isolating layer of 200 nm SiO2, the glass substrate contribution is reduced to about 25%.

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Mehra, Rukmankesh, and Kasper P. Kepp. "Contribution of substrate reorganization energies of electron transfer to laccase activity." Physical Chemistry Chemical Physics 21, no. 28 (2019): 15805–14. http://dx.doi.org/10.1039/c9cp01012b.

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Yio, Marcus H. N., Virginia Stovin, Jörg Werdin, and Gianni Vesuviano. "Experimental analysis of green roof substrate detention characteristics." Water Science and Technology 68, no. 7 (October 1, 2013): 1477–86. http://dx.doi.org/10.2166/wst.2013.381.

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Green roofs may make an important contribution to urban stormwater management. Rainfall-runoff models are required to evaluate green roof responses to specific rainfall inputs. The roof's hydrological response is a function of its configuration, with the substrate – or growing media – providing both retention and detention of rainfall. The objective of the research described here is to quantify the detention effects due to green roof substrates, and to propose a suitable hydrological modelling approach. Laboratory results from experimental detention tests on green roof substrates are presented. It is shown that detention increases with substrate depth and as a result of increasing substrate organic content. Model structures based on reservoir routing are evaluated, and it is found that a one-parameter reservoir routing model coupled with a parameter that describes the delay to start of runoff best fits the observed data. Preliminary findings support the hypothesis that the reservoir routing parameter values can be defined from the substrate's physical characteristics.

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Jin, Eunsook S., A. Dean Sherry, and Craig R. Malloy. "Metabolism of Glycerol, Glucose, and Lactate in the Citric Acid Cycle Prior to Incorporation into Hepatic Acylglycerols." Journal of Biological Chemistry 288, no. 20 (April 9, 2013): 14488–96. http://dx.doi.org/10.1074/jbc.m113.461947.

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During hepatic lipogenesis, the glycerol backbone of acylglycerols originates from one of three sources: glucose, glycerol, or substrates passing through the citric acid cycle via glyceroneogenesis. The relative contribution of each substrate source to glycerol in rat liver acylglycerols was determined using 13C-enriched substrates and NMR. Animals received a fixed mixture of glucose, glycerol, and lactate; one group received [U-13C6]glucose, another received [U-13C3]glycerol, and the third received [U-13C3]lactate. After 3 h, the livers were harvested to extract fats, and the glycerol moiety from hydrolyzed acylglycerols was analyzed by 13C NMR. In either fed or fasted animals, glucose and glycerol provided the majority of the glycerol backbone carbons, whereas the contribution of lactate was small. In fed animals, glucose contributed >50% of the total newly synthesized glycerol backbone, and 35% of this contribution occurred after glucose had passed through the citric acid cycle. By comparison, the glycerol contribution was ∼40%, and of this, 17% of the exogenous glycerol passed first through the cycle. In fasted animals, exogenous glycerol became the major contributor to acylglycerols. The contribution from exogenous lactate did increase in fasted animals, but its overall contribution remained small. The contributions of glucose and glycerol that had passed through the citric acid cycle first increased in fasted animals from 35 to 71% for glucose and from 17 to 24% for glycerol. Thus, a substantial fraction from both substrate sources passed through the cycle prior to incorporation into the glycerol moiety of acylglycerols in the liver.

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Cho, Min-Hyung, James O. Wrabl, James Taylor, and Vincent J. Hilser. "Hidden dynamic signatures drive substrate selectivity in the disordered phosphoproteome." Proceedings of the National Academy of Sciences 117, no. 38 (September 8, 2020): 23606–16. http://dx.doi.org/10.1073/pnas.1921473117.

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Phosphorylation sites are hyperabundant in the eukaryotic disordered proteome, suggesting that conformational fluctuations play a major role in determining to what extent a kinase interacts with a particular substrate. In biophysical terms, substrate selectivity may be determined not just by the structural–chemical complementarity between the kinase and its protein substrates but also by the free energy difference between the conformational ensembles that are, or are not, recognized by the kinase. To test this hypothesis, we developed a statistical-thermodynamics-based informatics framework, which allows us to probe for the contribution of equilibrium fluctuations to phosphorylation, as evaluated by the ability to predict Ser/Thr/Tyr phosphorylation sites in the disordered proteome. Essential to this framework is a decomposition of substrate sequence information into two types: vertical information encoding conserved kinase specificity motifs and horizontal information encoding substrate conformational equilibrium that is embedded, but often not apparent, within position-specific conservation patterns. We find not only that conformational fluctuations play a major role but also that they are the dominant contribution to substrate selectivity. In fact, the main substrate classifier distinguishing selectivity is the magnitude of change in local compaction of the disordered chain upon phosphorylation of these mostly singly phosphorylated sites. In addition to providing fundamental insights into the consequences of phosphorylation across the proteome, our approach provides a statistical-thermodynamic strategy for partitioning any sequence-based search into contributions from structural–chemical complementarity and those from changes in conformational equilibrium.

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Stamenović, Dimitrije, Srboljub M. Mijailovich, Iva Marija Tolić-Nørrelykke, Jianxin Chen, and Ning Wang. "Cell prestress. II. Contribution of microtubules." American Journal of Physiology-Cell Physiology 282, no. 3 (March 1, 2002): C617—C624. http://dx.doi.org/10.1152/ajpcell.00271.2001.

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The tensegrity model hypothesizes that cytoskeleton-based microtubules (MTs) carry compression as they balance a portion of cell contractile stress. To test this hypothesis, we used traction force microscopy to measure traction at the interface of adhering human airway smooth muscle cells and a flexible polyacrylamide gel substrate. The prediction is that if MTs balance a portion of contractile stress, then, upon their disruption, the portion of stress balanced by MTs would shift to the substrate, thereby causing an increase in traction. Measurements were done first in maximally activated cells (10 μM histamine) and then again after MTs had been disrupted (1 μM colchicine). We found that after disruption of MTs, traction increased on average by ∼13%. Because in activated cells colchicine induced neither an increase in intracellular Ca2+ nor an increase in myosin light chain phosphorylation as shown previously, we concluded that the observed increase in traction was a result of load shift from MTs to the substrate. In addition, energy stored in the flexible substrate was calculated as work done by traction on the deformation of the substrate. This result was then utilized in an energetic analysis. We assumed that cytoskeleton-based MTs are slender elastic rods supported laterally by intermediate filaments and that MTs buckle as the cell contracts. Using the post-buckling equilibrium theory of Euler struts, we found that energy stored during buckling of MTs was quantitatively consistent with the measured increase in substrate energy after disruption of MTs. This is further evidence supporting the idea that MTs are intracellular compression-bearing elements.

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Yildirim, Can, Philippe Ballet, Jean-Louis Santailler, Dominique Giotta, Rémy Obrecht, Thu Nhi Tran Thi, José Baruchel, and Delphine Brellier. "Role of threading dislocations on the growth of HgCdTe epilayers investigated using monochromatic X-ray Bragg diffraction imaging." Journal of Synchrotron Radiation 28, no. 1 (January 1, 2021): 301–8. http://dx.doi.org/10.1107/s1600577520014149.

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High-quality Hg1–x Cd x Te (MCT) single crystals are essential for two-dimensional infrared detector arrays. Crystal quality plays an important role on the performance of these devices. Here, the dislocations present at the interface of CdZnTe (CZT) substrates and liquid-phase epitaxy grown MCT epilayers are investigated using X-ray Bragg diffraction imaging (XBDI). The diffraction contributions coming from the threading dislocations (TDs) of the CZT substrate and the MCT epilayers are separated using weak-beam conditions in projection topographs. The results clearly suggest that the lattice parameter of the growing MCT epilayer is, at the growth inception, very close to that of the CZT substrate and gradually departs from the substrate's lattice parameter as the growth advances. Moreover, the relative growth velocity of the MCT epilayer around the TDs is found to be faster by a factor of two to four compared with the matrix. In addition, a fast alternative method to the conventional characterization methods for probing crystals with low dislocation density such as atomic force microscopy and optical interferometry is introduced. A 1.5 mm × 1.5 mm area map of the epilayer defects with sub-micrometre spatial resolution is generated, using section XBDI, by blocking the diffraction contribution of the substrate and scanning the sample spatially.

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Xu, Ming, K. Sam Wells, and Ronald B. Emeson. "Substrate-dependent Contribution of Double-stranded RNA-binding Motifs to ADAR2 Function." Molecular Biology of the Cell 17, no. 7 (July 2006): 3211–20. http://dx.doi.org/10.1091/mbc.e06-02-0162.

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ADAR2 is a double-stranded RNA-specific adenosine deaminase involved in the editing of mammalian RNAs by the site-specific conversion of adenosine to inosine (A-to-I). ADAR2 contains two tandem double-stranded RNA-binding motifs (dsRBMs) that are not only important for efficient editing of RNA substrates but also necessary for localizing ADAR2 to nucleoli. The sequence and structural similarity of these motifs have raised questions regarding the role(s) that each dsRBM plays in ADAR2 function. Here, we demonstrate that the dsRBMs of ADAR2 differ in both their ability to modulate subnuclear localization as well as to promote site-selective A-to-I conversion. Surprisingly, dsRBM1 contributes to editing activity in a substrate-dependent manner, indicating that dsRBMs recognize distinct structural determinants in each RNA substrate. Although dsRBM2 is essential for the editing of all substrates examined, a point mutation in this motif affects editing for only a subset of RNAs, suggesting that dsRBM2 uses unique sets of amino acid(s) for functional interactions with different RNA targets. The dsRBMs of ADAR2 are interchangeable for subnuclear targeting, yet such motif alterations do not support site-selective editing, indicating that the unique binding preferences of each dsRBM differentially contribute to their pleiotropic function.

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Álvarez-Troncoso, Romina, Cesar João Benetti, Amadou Babacar Sarr, and Josefina Garrido. "The microhabitat preferences of Trichoptera in rivers in north-western Spain." Marine and Freshwater Research 68, no. 9 (2017): 1686. http://dx.doi.org/10.1071/mf16246.

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We analysed the microhabitat preferences of caddisfly species in four rivers in north-western Spain. In each river, we sampled five sites with different types of substrate. These sites were characterised in situ according to the predominant material type (macrophytes, moss, pebbles and sand). A one-way ANOVA was used to test for significant differences in species abundance among substrates, and a nested ANOVA was used to test for significant differences in physical and chemical variables among rivers and sampling sites. A similarity percentage-species contribution analysis was performed to estimate the contribution of each species to the characterisation of each substrate. We observed significant differences in the abundance of seven species (Drusus bolivari, Glossosoma privatum, Larcasia partita, Micrasema longulum, M. servatum, M. gr. moestum and Sericostoma sp.) among substrates, confirming that these species have substrate preferences. According to similarity percentage-species contribution, the species that contributed most to differences were as follows: for sand, Sericostoma sp.; for macrophytes, Rhyacophila adjuncta, Hydropsyche ambigua, Sericostoma sp.; for moss, Micrasema gr. moestum, M. servatum, M. longulum, Hydropsyche tibialis and R. adjuncta; and for pebbles, Sericostoma sp., Larcasia partita and H. tibialis. These preferences can be explained by the fact that different species use different materials from the substrate to build their cases and also as a source of stability, protection and food.

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Chen, Lang, J.-H. Li, J. Slutsker, J. Ouyang, and A. L. Roytburd. "Contribution of substrate to converse piezoelectric response of constrained thin films." Journal of Materials Research 19, no. 10 (October 1, 2004): 2853–58. http://dx.doi.org/10.1557/jmr.2004.0367.

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The converse piezoelectric response of a thin film constrained by a substrate is analyzed in different geometries under various boundary conditions. We considerthe effects of elastic deformation of the substrate on the total displacement of thefilm surface induced by the electric field. The change of film thickness and the bending curvature of a film/substrate couple are calculated. For a thin film island clamped on a large thick substrate, the theoretical estimation of the piezoresponse, including a local bending in the vicinity of the island/substrate interface, is in agreement with the finite element calculation.

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McNulty, Patrick H., Gary W. Cline, Jennifer M. Whiting, and Gerald I. Shulman. "Regulation of myocardial [13C]glucose metabolism in conscious rats." American Journal of Physiology-Heart and Circulatory Physiology 279, no. 1 (July 1, 2000): H375—H381. http://dx.doi.org/10.1152/ajpheart.2000.279.1.h375.

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Administration of supplemental glucose and/or insulin is postulated to improve the outcome from myocardial ischemia by increasing the heart's relative utilization of glucose as an energy substrate. To examine the degree to which circulating glucose and insulin levels actually influence myocardial substrate preference in vivo, we infused conscious, chronically catheterized rats withd-[1-13C]glucose and compared steady-state13C enrichment of plasma glucose with that of myocardial glycolytic ([3-13C]alanine) and oxidative ([4-13C]glutamate) intermediary metabolites. In fasting rats, [3-13C]alanine-to-[1-13C]glucose and [4-13C]glutamate-to-[3-13C]alanine ratios averaged 0.16 ± 0.12 and 0.14 ± 0.03, respectively, indicating that circulating glucose contributed 32% of myocardial glycolytic flux, whereas subsequent flux through pyruvate dehydrogenase contributed 14% of total tricarboxylic acid (TCA) cycle activity. Raising plasma glucose to 11 mmol/l, or insulin to 500 pmol/l, increased these contributions equivalently. At supraphysiological (>6,500 pmol/l) insulin levels, the plasma glucose contribution to glycolysis increased further, and addition of hyperglycemia made it the sole glycolytic substrate, yet [4-13C]glutamate-to-[3-13C]alanine ratios remained ≤0.60. Thus plasma levels of glucose and insulin independently regulate the proportional contribution of exogenous glucose to myocardial glycolytic and TCA cycle flux in vivo in a dose-dependent manner. However, even at supraphysiological levels, nonglucose substrates continue to supply ≥40% of myocardial TCA cycle flux.

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Scott, J. F. "Contribution to Pyroelectricity from Domain Walls and Substrate Strain." Ferroelectrics 472, no. 1 (November 18, 2014): 19–28. http://dx.doi.org/10.1080/00150193.2014.964103.

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Papaioannou, E. H., and M. Liakopoulou-Kyriakides. "Substrate contribution on carotenoids production in Blakeslea trispora cultivations." Food and Bioproducts Processing 88, no. 2-3 (June 2010): 305–11. http://dx.doi.org/10.1016/j.fbp.2009.03.001.

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Oh, Gyung-Geun, Young-Chae Song, Byung-Uk Bae, and Chae-Young Lee. "Electric Field-Driven Direct Interspecies Electron Transfer for Bioelectrochemical Methane Production from Fermentable and Non-Fermentable Substrates." Processes 8, no. 10 (October 15, 2020): 1293. http://dx.doi.org/10.3390/pr8101293.

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The bioelectrochemical methane production from acetate as a non-fermentable substrate, glucose as a fermentable substrate, and their mixture were investigated in an anaerobic sequential batch reactor exposed to an electric field. The electric field enriched the bulk solution with exoelectrogenic bacteria (EEB) and electrotrophic methanogenic archaea, and promoted direct interspecies electron transfer (DIET) for methane production. However, bioelectrochemical methane production was dependent on the substrate characteristics. For acetate as the substrate, the main electron transfer pathway for methane production was DIET, which significantly improved methane yield up to 305.1 mL/g chemical oxygen demand removed (CODr), 77.3% higher than that in control without the electric field. For glucose, substrate competition between EEB and fermenting bacteria reduced the contribution of DIET to methane production, resulting in the methane yield of 288.0 mL/g CODr, slightly lower than that of acetate. In the mixture of acetate and glucose, the contribution of DIET to methane production was less than that of the single substrate, acetate or glucose, due to the increase in the electron equivalent for microbial growth. The findings provide a better understanding of electron transfer pathways, biomass growth, and electron transfer losses depending on the properties of substrates in bioelectrochemical methane production.

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Zacková, Paulína, Lucia Števlíková, Ľubomír Čaplovič, Martin Sahul, and Vitali Podgurski. "Effect of Pulsed Laser Ablation on the Increase of Adhesion of CRN Coating-Substrate." Research Papers Faculty of Materials Science and Technology Slovak University of Technology 26, no. 43 (September 1, 2018): 61–70. http://dx.doi.org/10.2478/rput-2018-0031.

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Abstract The contribution deals with analysis of the influence of the substrate surface laser ablation before deposition process to improve the adhesion of coating-substrate system. The coatings were applied to the high-speed steel 6-5-2-5 (STN 19 852) and WC-Co cemented carbide with cobalt content of 10 wt%. LAteral Rotating Cathodes (LARC®) process was chosen for evaporation of individual CrN layers. Influence of laser ablation on the substrate morphology, structure, roughness, presence of residual stresses inside the substrates and layers and their adhesion behavior between the layers and the base material was studied. Scanning electron microscopy fitted with energy dispersive spectroscopy was utilized to investigate morphology and fracture areas of substrates with CrN layers. X-ray diffraction analysis was employed to detect the residual stresses measurements. Adhesion between the coatings and substrate was analyzed using “Mercedes” testing.

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Kajimoto, Masaki, Colleen M. O'Kelly Priddy, Dolena R. Ledee, Chun Xu, Nancy Isern, Aaron K. Olson, and Michael A. Portman. "Effects of continuous triiodothyronine infusion on the tricarboxylic acid cycle in the normal immature swine heart under extracorporeal membrane oxygenation in vivo." American Journal of Physiology-Heart and Circulatory Physiology 306, no. 8 (April 15, 2014): H1164—H1170. http://dx.doi.org/10.1152/ajpheart.00964.2013.

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Extracorporeal membrane oxygenation (ECMO) is frequently used in infants with postoperative cardiopulmonary failure. ECMO also suppresses circulating triiodothyronine (T3) levels and modifies myocardial metabolism. We assessed the hypothesis that T3 supplementation reverses ECMO-induced metabolic abnormalities in the immature heart. Twenty-two male Yorkshire pigs (age: 25–38 days) with ECMO received [2-13C]lactate, [2,4,6,8-13C4]octanoate (medium-chain fatty acid), and [U-13C]long-chain fatty acids as metabolic tracers either systemically (totally physiological intracoronary concentration) or directly into the coronary artery (high substrate concentration) for the last 60 min of each protocol. NMR analysis of left ventricular tissue determined the fractional contribution of these substrates to the tricarboxylic acid cycle. Fifty percent of the pigs in each group received intravenous T3 supplement (bolus at 0.6 μg/kg and then continuous infusion at 0.2 μg·kg−1·h−1) during ECMO. Under both substrate loading conditions, T3 significantly increased the fractional contribution of lactate with a marginal increase in the fractional contribution of octanoate. Both T3 and high substrate provision increased the myocardial energy status, as indexed by phosphocreatine concentration/ATP concentration. In conclusion, T3 supplementation promoted lactate metabolism to the tricarboxylic acid cycle during ECMO, suggesting that T3 releases the inhibition of pyruvate dehydrogenase. Manipulation of substrate utilization by T3 may be used therapeutically during ECMO to improve the resting energy state and facilitate weaning.

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VILLAGÓMEZ, R. "INFRARED OPTICAL RESPONSE FROM Nb ON SiO2 ULTRATHIN FILMS." Modern Physics Letters B 21, no. 25 (October 30, 2007): 1723–32. http://dx.doi.org/10.1142/s021798490701405x.

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Oscillations in the infrared reflectance from metallic ultrathin films are described as consequence of quantum size effects. In this contribution, we present experimental evidence of such oscillations for Nb ultrathin films deposited on α-type SiO 2 substrates. Also, it is shown how substrates influence the size effects and the amplitude but not the period of oscillations. Because of the strong influence from the chosen substrate due to absorption, IR reflectivity was fitted to the optical response of our metal-substrate and bare-substrate system by using the three-oscillator model and numerical calculations on the basis of the local field calculation for a single metallic quantum well. Although quantum size effects are well studied in semiconductor compounds, there are few studies of this effect in metallic films where the present investigation has its most important contribution. Measurements for p-polarized reflectance (Rp) are made using a tunable p-polarized CO 2 waveguide laser using wavelengths from the p-branch (9.4 to 9.7 μm) and R-branch (10.0 to 10.4 μm). Nb/SiO 2 ultrathin films were assembled by a conventional RF sputtering technique and tailored thicknesses were deposited from 5.5 to 55 Å.

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Rojas-Gómez, Óscar A., Margarida M. Telo da Gama, and José M. Romero-Enrique. "Wetting of Nematic Liquid Crystals on Crenellated Substrates: A Frank–Oseen Approach." Crystals 9, no. 8 (August 19, 2019): 430. http://dx.doi.org/10.3390/cryst9080430.

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We revisit the wetting of nematic liquid crystals in contact with crenellated substrates, studied previously using the Landau–de Gennes formalism. However, due to computational limitations, the characteristic length scales of the substrate relief considered in that study limited to less than 100 nematic correlation lengths. The current work uses an extended Frank–Oseen formalism, which includes not only the free-energy contribution due to the elastic deformations but also the surface tension contributions and, if disclinations or other orientational field singularities are present, their core contributions. Within this framework, which was successfully applied to the anchoring transitions of a nematic liquid crystal in contact with structured substrates, we extended the study to much larger length scales including the macroscopic scale. In particular, we analyzed the interfacial states and the transitions between them at the nematic–isotropic coexistence.

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Fujihashi, Masahiro, Toyokazu Ishida, Shingo Kuroda, Kazuya Mito, Lakshmi Kotra, Emil Pai, and Kunio Miki. "Substrate distortion in the catalysis of orotidine monophosphate decarboxylase." Acta Crystallographica Section A Foundations and Advances 70, a1 (August 5, 2014): C447. http://dx.doi.org/10.1107/s2053273314095527.

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One way for enzymes to affect reactions they catalyze is through transition state stabilization. Another factor to be considered is the contribution of substrate distortion, although it has been thoroughly described for only a few enzymes. We have a longstanding interest in the reaction mechanism of orotidine monophosphate decarboxylase (ODCase) and determined various crystal structures bound with distorted substrates at around 1.5 Å resolution. The enzyme is known as one of the most proficient enzymes, which accelerates the decarboxylation of orotidine 5'-monophosphate (OMP) to form uridine 5'-monophosphate (UMP) by 17 orders of magnitude. One argument against the contribution of substrate distortion to the ODCase reaction is the weak affinity of UMP. The distortions observed so far all appear at the C6-substituent of the pyrimidine ring, which corresponds to the carboxylate of OMP. Since the carboxylate is removed by the reaction, the product UMP should bind more tightly to ODCase than OMP, if the distortion of C6-substituent contributes to the catalysis. In order to investigate this inconsistency, we determined the crystal structure of ODCase with UMP at atomic resolution (1.03 Å). The structure showed an unfavorable interaction between UMP and the catalytic residue K72, an interaction considered to be absent in the OMP complex. Surface plasmon resonance analysis indicated that UMP binds stronger to the K72A mutant than to the wild-type enzyme by 5 orders of magnitude. These analyses invalidate the argument against a contribution of substrate distortion to ODCase catalysis. Finally, we estimated how much the distortion contributes to the catalysis using computational simulation methods. The results indicated that 10-15% decrease of the ΔΔG‡ value is contributed by substrate distortion.

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Kosterin, S. O., S. O. Karakhim, and P. F. Zhuk. "Consideration of the contribution of chemical (non-enzymatic) conversion of substrate in the general mechanism of enzyme reaction." Ukrainian Biochemical Journal 91, no. 4 (June 14, 2019): 78–87. http://dx.doi.org/10.15407/ubj91.04.078.

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Chatham, J. C., and J. R. Forder. "Relationship between cardiac function and substrate oxidation in hearts of diabetic rats." American Journal of Physiology-Heart and Circulatory Physiology 273, no. 1 (July 1, 1997): H52—H58. http://dx.doi.org/10.1152/ajpheart.1997.273.1.h52.

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The effects of streptozotocin-induced diabetes on myocardial substrate oxidation and contractile function were investigated using 13C nuclear magnetic resonance (NMR) spectroscopy. To determine the consequences of diabetes on glucose oxidation, hearts were perfused with [1–13C]glucose (11 mM) alone as well as in the presence of insulin (to stimulate glucose transport) and dichloroacetate (to stimulate pyruvate dehydrogenase). The contribution of glucose to the tricarboxylic acid (TCA) cycle was significantly decreased in hearts from diabetic animals compared with controls, with glucose alone and with insulin; however, the addition of dichloroacetate significantly increased the contribution of glucose to the TCA cycle. Contractile function in hearts from diabetic animals was significantly depressed with glucose as the sole substrate, regardless of the presence of insulin or dichloroacetate (P < 0.0005). To determine whether diabetes had any direct effects on beta-oxidation and the TCA cycle, hearts were perfused with glucose (11 mM) plus [6-13C]hexanoate (0.5 mM) as substrates. In control hearts, with glucose plus hexanoate as substrates, hexanoate contributed 98.9 +/- 2% of the substrate entering the TCA cycle; this was significantly decreased to 90.7 +/- 0.6% in the diabetic group (P < 0.02). The addition of hexanoate to the perfusate resulted in a significant increase in peak systolic pressure in the diabetic group (P < 0.001) such that contractile function was indistinguishable from controls.

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Labarthe, François, Maya Khairallah, Bertrand Bouchard, William C. Stanley, and Christine Des Rosiers. "Fatty acid oxidation and its impact on response of spontaneously hypertensive rat hearts to an adrenergic stress: benefits of a medium-chain fatty acid." American Journal of Physiology-Heart and Circulatory Physiology 288, no. 3 (March 2005): H1425—H1436. http://dx.doi.org/10.1152/ajpheart.00722.2004.

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The spontaneously hypertensive rat (SHR) is a model of cardiomyopathy characterized by a restricted use of exogenous long-chain fatty acid (LCFA) for energy production. The aims of the present study were to document the functional and metabolic response of the SHR heart under conditions of increased energy demand and the effects of a medium-chain fatty acid (MCFA; octanoate) supplementation in this situation. Hearts were perfused ex vivo in a working mode with physiological concentrations of substrates and hormones and subjected to an adrenergic stimulation (epinephrine, 10 μM). 13C-labeled substrates were used to assess substrate selection for energy production. Compared with control Wistar rat hearts, SHR hearts showed an impaired response to the adrenergic stimulation as reflected by 1) a smaller increase in contractility and developed pressure, 2) a faster decline in the aortic flow, and 3) greater cardiac tissue damage (lactate dehydrogenase release: 1,577 ± 118 vs. 825 ± 44 mU/min, P < 0.01). At the metabolic level, SHR hearts presented 1) a reduced exogenous LCFA contribution to the citric acid cycle flux (16 ± 1 vs. 44 ± 4%, P < 0.001) and an enhanced contribution of endogenous substrates (20 ± 4 vs. 1 ± 4%, P < 0.01); and 2) an increased lactate production from glycolysis, with a greater lactate-to-pyruvate production ratio. Addition of 0.2 mM octanoate reduced lactate dehydrogenase release (1,145 ± 155 vs. 1,890 ± 89 mU/min, P < 0.001) and increased exogenous fatty acid contribution to energy metabolism (23.7 ± 1.3 vs. 15.8 ± 0.8%, P < 0.01), which was accompanied by an equivalent decrease in unlabeled endogenous substrate contribution, possibly triglycerides (11.6 ± 1.5 vs. 19.0 ± 1.2%, P < 0.01). Taken altogether, these results demonstrate that the SHR heart shows an impaired capacity to withstand an acute adrenergic stress, which can be improved by increasing the contribution of exogenous fatty acid oxidation to energy production by MCFA supplementation.

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Uchida, S., and H. Endou. "Substrate specificity to maintain cellular ATP along the mouse nephron." American Journal of Physiology-Renal Physiology 255, no. 5 (November 1, 1988): F977—F983. http://dx.doi.org/10.1152/ajprenal.1988.255.5.f977.

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To evaluate substrate utilization along the mouse nephron, cellular ATP content was measured under various conditions by the luciferin-luciferase technique. Individual micro-dissected nephron segments were incubated in a modified Hanks' solution (pH 7.4) with or without each of the following substrates: D-glucose, DL-lactate, beta-hydroxybutyrate (HBA), and L-glutamine. ATP production from glucose was minimal in the early proximal tubule (S1), but was substantial in the late proximal tubule (S3). Glutamine and lactate were the preferred substrates in proximal tubules. In contrast, ATP production from glutamine was less than that from the other substrates in distal nephron segments, including medullary and cortical thick ascending limbs of Henle's loop (MTAL and CTAL), distal tubule including the connecting tubule (DT), and cortical and medullary collecting tubules (CCT and MCT). Lactate and HBA were preferred substrates for ATP maintenance in CTAL, MTAL, and DT. Glucose was the best substrate in CCT. In addition, the specific contribution of anaerobic metabolism to maintaining cellular ATP was low in MTAL and CTAL. On the other hand, the glycolytic capacity of CCT and MCT was high. The above results demonstrate the substrate requirements for maintaining cellular ATP content within specific nephron segments.

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Hanson, Anne-Marie, J. Roger Harris, Robert Wright, Alex Niemiera, and Naraine Persaud. "Water Content of a Pine-bark Growing Substrate in a Drying Mineral Soil." HortScience 39, no. 3 (June 2004): 591–94. http://dx.doi.org/10.21273/hortsci.39.3.591.

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Newly transplanted container-grown landscape plants are reported to require very frequent irrigation. However, container nurseries in the U.S. commonly use growing substrates that are mostly bark, even though the contribution of bark-based growing substrates to water relations of transplanted root balls is unknown. Therefore, a field experiment was undertaken to determine water relations of a pine-bark substrate (container removed) within a drying mineral soil over a three week period. A range of common production container sizes—3.7 L (#1), 7.5 L (#2), 21.9 L (#7), 50.6 L (#15), and 104.5 L (#25)—was used. The fraction of substrate volume that is water [total volumetric water (TVW)] within the top and middle zones of substrate was compared to TVW at corresponding depths of adjacent mineral soil. The fraction of substrate and soil volume that is plant-available water [plant-available volumetric water (PAVW)] was calculated by subtracting the fraction of substrate or soil volume below where water is unavailable to most plants (measured with pressure plates) [plant-unavailable volumetric water (PUVW)] from each TVW measurement. The pine-bark substrate had a PUVW of 0.32 compared to a PUVW of 0.06 for soil. Top sections of substrate dried to near zero PAVW 6 days after irrigation for all containers. Larger container sizes maintained higher PAVW in middle sections than smaller container sizes, and PAVW was always higher in the adjacent soil than in the embedded substrate. Overall, very little PAVW is held by the embedded pine-bark growing substrate, suggesting the need for container substrates with greater water retention once transplanted to mineral soils.

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Moraïs, Sarah, Yoav Barak, Jonathan Caspi, Yitzhak Hadar, Raphael Lamed, Yuval Shoham, David B. Wilson, and Edward A. Bayer. "Contribution of a Xylan-Binding Module to the Degradation of a Complex Cellulosic Substrate by Designer Cellulosomes." Applied and Environmental Microbiology 76, no. 12 (April 16, 2010): 3787–96. http://dx.doi.org/10.1128/aem.00266-10.

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ABSTRACT Conversion of components of the Thermobifida fusca free-enzyme system to the cellulosomal mode using the designer cellulosome approach can be employed to discover the properties and inherent advantages of the cellulosome system. In this article, we describe the conversion of the T. fusca xylanases Xyn11A and Xyn10B and their synergistic interaction in the free state or within designer cellulosome complexes in order to enhance specific degradation of hatched wheat straw as a model for a complex cellulosic substrate. Endoglucanase Cel5A from the same bacterium and its recombinant dockerin-containing chimera were also studied for their combined effect, together with the xylanases, on straw degradation. Synergism was demonstrated when Xyn11A was combined with Xyn10B and/or Cel5A, and ∼1.5-fold activity enhancements were achieved by the designer cellulosome complexes compared to the free wild-type enzymes. These improvements in activity were due to both substrate-targeting and proximity effects among the enzymes contained in the designer cellulosome complexes. The intrinsic cellulose/xylan-binding module (XBM) of Xyn11A appeared to be essential for efficient substrate degradation. Indeed, only designer cellulosomes in which the XBM was maintained as a component of Xyn11A achieved marked enhancement in activity compared to the combination of wild-type enzymes. Moreover, integration of the XBM in designer cellulosomes via a dockerin module (separate from the Xyn11A catalytic module) failed to enhance activity, suggesting a role in orienting the parent xylanase toward its preferred polysaccharide component of the complex wheat straw substrate. The results provide novel mechanistic insight into the synergistic activity of designer cellulosome components on natural plant cell wall substrates.

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Pompeo, N., R. Marcon, and E. Silva. "Substrate Contribution to the Surface Impedance of HTS Films on Si." Journal of Superconductivity and Novel Magnetism 19, no. 7-8 (January 10, 2007): 611–15. http://dx.doi.org/10.1007/s10948-006-0208-1.

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Marcus, Nancy Y., Roland A. Marcus, Bela Z. Schmidt, and David B. Haslam. "Contribution of the HEDJ/ERdj3 cysteine-rich domain to substrate interactions." Archives of Biochemistry and Biophysics 468, no. 2 (December 2007): 147–58. http://dx.doi.org/10.1016/j.abb.2007.10.001.

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28

Gosch, C., H. Flachowsky, H. Halbwirth, J. Thill, R. Mjka-Wittmann, D. Treutter, K. Richter, M. V. Hanke, and K. Stich. "Substrate specificity and contribution of the glycosyltransferase UGT71A15 to phloridzin biosynthesis." Trees 26, no. 1 (December 28, 2011): 259–71. http://dx.doi.org/10.1007/s00468-011-0669-0.

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29

Sakamoto, Naoya, Yoshimasa Yamazaki, Toshiro Ohashi, and Masaaki Sato. "Effect of Mechanical Environment of Focal Adhesions on Remodeling of Endothelial Cells Subjected to Cyclic Stretching Using Microsubstrates." Journal of Robotics and Mechatronics 19, no. 5 (October 20, 2007): 557–64. http://dx.doi.org/10.20965/jrm.2007.p0557.

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Endothelial cells (ECs) adapt to mechanical environments such as cyclic stretching by altering their morphology and cytoskeletal structure. The detailed mechanism underlying EC remodeling in response to cyclic stretching, however, remains unclear. To understand the contribution of strain in contact area between focal adhesions (FAs) and the substrate to morphological and cytoskeletal changes in cells, we applied cyclic stretching to ECs using a microsubstrate with arrays of micropillars on which cells were selectively stretched between FAs but FA-substrate contact area were hardly stretched. Bovine aortic ECs were seeded on a silicone elastomer micropillar substrate in a silicone chamber. ECs were then subjected to 20% stretching at 0.5 Hz for up to 6 h using a stretching apparatus. Cells stretched on a flat substrate were also observed. Under static conditions, no significant difference was seen in EC morphology between flat and micropillar substrates. After exposure to cyclic stretching for 3 h, ECs on both flat and micropillar substrates were aligned perpendicular to the direction of stretching. Stress fibers were oriented about 60° to the direction of stretching on the flat substrate, while stress fibers were not aligned in any direction for the micropillar substrate. After 6 h of stretching, stress fibers on the micropillar substrate were oriented approximately 90° to the direction of stretching. These results suggest that strain in contact area between FAs and the substrate may have an impact on reorientation rates of stress fibers in ECs in response to cyclic stretching.

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Rezaie, Alireza R. "Contribution of the 60 Loop To Substrate and Inhibitor Specificity of Thrombin." Blood 104, no. 11 (November 16, 2004): 1734. http://dx.doi.org/10.1182/blood.v104.11.1734.1734.

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Relative to chymotrypsin, the 60-loop of thrombin contains 8–9 insertion residues which are believed to be partly responsible for the restricted substrate and inhibitor specificity of thrombin. Previous deletion of 3–4 residues of this loop (des-PPW and des-YPPW) dramatically impaired the activity of thrombin toward antithrombin, protein C and fibrinogen, implicating a key role for the productive interaction of these residues with the target macromolecules. To further investigate the role of this loop, we expressed a mutant of thrombin in which all 8 insertion residues (Tyr-Pro-Pro-Trp-Asp-Lys-Asn-Phe) of the 60-loop were deleted (des-60-loop). In contrast to the partially deleted loop mutants, we discovered that des-60-loop thrombin cleaved small synthetic substrates, clotted purified fibrinogen, and activated protein C with a near normal catalytic efficiency; however, its activity toward cofactors V and VIII was impaired ~2–4-fold. Further studies revealed that the reactivity of des-60-loop with antithrombin is not impaired, but rather improved ~2-fold. Remarkably, the mutant could also activate prothrombin to thrombin. These results suggest that the 60-loop plays a key role in regulating the specificity of thrombin by shielding the active-site pocket; however, its productive interaction with the target molecules may not be as critical for the catalytic function of thrombin as has been speculated in previous reports.

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Lewis, David F. V. "Hydrogen Bonding in Human P450-Substrate Interactions: A Major Contribution to Binding Affinity." Scientific World JOURNAL 4 (2004): 1074–82. http://dx.doi.org/10.1100/tsw.2004.210.

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The importance of hydrogen bonding, a relatively strong intermolecular force of attraction between molecules in biological systems, is discussed in the respect of P450 substrate affinity towards one or more of the human P450 enzymes that are generally associated with drug and other xenobiotic metabolism. It is shown that calculation of hydrogen bond distances and energies based on simple empirical relationships provide values that agree closely with experimental findings. It is thus possible to estimate the hydrogen bond contribution to P450 enzyme-substrate binding affinity based on modelled interactions and by use of these relatively simple formulae, particularly when employed in conjunction with substrate-lipophilicity relationships.

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32

Kajimoto, Masaki, Dolena R. Ledee, Nancy G. Isern, and Michael A. Portman. "Right ventricular metabolism during venoarterial extracorporeal membrane oxygenation in immature swine heart in vivo." American Journal of Physiology-Heart and Circulatory Physiology 312, no. 4 (April 1, 2017): H721—H727. http://dx.doi.org/10.1152/ajpheart.00835.2016.

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Venoarterial extracorporeal membrane oxygenation (VA-ECMO) provides hemodynamic rescue for patients encountering right or left ventricular (RV or LV) decompensation, particularly after surgery for congenital heart defects. ECMO, supported metabolically by parenteral nutrition, provides reductions in myocardial work and energy demand and, therefore, enhances functional recovery. The RV must often assume systemic ventricular pressures and function on weaning from VA-ECMO. However the substrate utilization responses of the RV to VA-ECMO or stimulation are unknown. We determined RV and LV substrate utilization response to VA-ECMO in immature swine heart. Mixed-breed male Yorkshire pigs (33–49 days old) underwent normal pressure volume loading (control, n = 5) or were unloaded by VA-ECMO (ECMO, n = 10) for 8 h. Five pigs with ECMO received intravenous thyroid hormone [triiodothyronine (T3)] to alter substrate utilization. Carbon 13 (13C)-labeled substrates (lactate and medium-chain and long-chain fatty acids) were systemically infused as metabolic tracers. Analyses by nuclear magnetic resonance showed that both ventricles have similar trends of fractional 13C-labeled substrate contributions to the citric acid cycle under control conditions. VA-ECMO produced higher long-chain fatty acids and lower lactate contribution to the citric acid cycle via inhibition of pyruvate dehydrogenase, whereas T3 promoted lactate metabolism in both ventricles. However, these metabolic shifts were smaller in RV, and RV fatty acid contributions showed minimal response to perturbations. Furthermore, VA-ECMO and T3 also achieved high [phosphocreatine]/[ATP] and low [NADH]/[NAD+] in LV but not in RV. These data suggest that the RV shows decreased ability to modify substrate utilization and achieve improvements in energy supply/demand during VA-ECMO. NEW & NOTEWORTHY We showed that the right ventricle unloaded by venoarterial extracorporeal membrane oxygenation (VA-ECMO) has diminished capacity to alter substrate utilization compared with the left ventricle. This decrease in metabolic flexibility contributes to the inability to increase high-energy phosphate reserves during myocardial rest by VA-ECMO.

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33

Beccari, M., D. Dionisi, A. Giuliani, M. Majone, and R. Ramadori. "Effect of different carbon sources on aerobic storage by activated sludge." Water Science and Technology 45, no. 6 (March 1, 2002): 157–68. http://dx.doi.org/10.2166/wst.2002.0103.

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A study of substrate removal by real activated sludge with several synthetic substrates (acetate, ethanol, glutamic acid) and wastewater (raw and filtered) was carried out. Substrate, stored compounds (polyhydroxyalkanoates, PHA and internal carbohydrates), ammonia and oxygen uptake rate (OUR) were analytically determined. Polyhydroxybutyrate (PHB) was stored when the substrate was acetate or ethanol, while no appreciable formation of storage compound was detected using glutamic acid. A low amount of PHB was also formed in tests with raw and filtered wastewater which was probably mainly due to its acetate content. As far as the sum of storage and growth (indirectly estimated through ammonia consumption) did not match the overall solids formation, other unidentified mechanisms of substrate removal were likely to occur (biosorption, accumulation and/or storage of unidentified compounds). ASM3 and two derived models were used in the interpretation of experimental data with reference to synthetic substrates. With reference to synthetic substrates ASM3 can well describe the experimental data only assuming a stored product formation much higher than the analytically detected one, whereas the model that assumes a parallel growth and storage on the substrate can well describe the observed stored product profile only assuming a direct contribution of growth much higher than estimated from ammonia consumption. The model that assumes an accumulation/biosorption stage as first step of substrate removal can better describe the whole experimentally observed behaviour. However as well as in ASM3 this implies that some fraction of removed COD is still unidentified. With reference to real wastewater where the different phenomena were mixed up due to the presence of several substrates, the different models gave similar results.

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Jakubowski, Simon J., Eric Cascales, Vidhya Krishnamoorthy, and Peter J. Christie. "Agrobacterium tumefaciens VirB9, an Outer-Membrane-Associated Component of a Type IV Secretion System, Regulates Substrate Selection and T-Pilus Biogenesis." Journal of Bacteriology 187, no. 10 (May 15, 2005): 3486–95. http://dx.doi.org/10.1128/jb.187.10.3486-3495.2005.

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ABSTRACT Agrobacterium tumefaciens translocates DNA and protein substrates between cells via a type IV secretion system (T4SS) whose channel subunits include the VirD4 coupling protein, VirB11 ATPase, VirB6, VirB8, VirB2, and VirB9. In this study, we used linker insertion mutagenesis to characterize the contribution of the outer-membrane-associated VirB9 to assembly and function of the VirB/D4 T4SS. Twenty-five dipeptide insertion mutations were classified as permissive for intercellular substrate transfer (Tra+), completely transfer defective (Tra−), or substrate discriminating, e.g., selectively permissive for transfer only of the oncogenic transfer DNA and the VirE2 protein substrates or of a mobilizable IncQ plasmid substrate. Mutations inhibiting transfer of DNA substrates did not affect formation of close contacts of the substrate with inner membrane channel subunits but blocked formation of contacts with the VirB2 and VirB9 channel subunits, which is indicative of a defect in assembly or function of the distal portion of the secretion channel. Several mutations in the N- and C-terminal regions disrupted VirB9 complex formation with the outer-membrane-associated lipoprotein VirB7 or the inner membrane energy sensor VirB10. Several VirB9.i2-producing Tra+ strains failed to elaborate T pilus at detectable levels (Pil−), and three such Tra+ Pil− mutant strains were rendered Tra− upon deletion of virB2, indicating that the cellular form of pilin protein is essential for substrate translocation. Our findings, together with computer-based analyses, support a model in which distinct domains of VirB9 contribute to substrate selection and translocation, establishment of channel subunit contacts, and T-pilus biogenesis.

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35

Turković, Erna, Ivana Vasiljević, Milica Drašković, Nataša Obradović, Dragana Vasiljević, and Jelena Parojčić. "An Investigation into Mechanical Properties and Printability of Potential Substrates for Inkjet Printing of Orodispersible Films." Pharmaceutics 13, no. 4 (March 30, 2021): 468. http://dx.doi.org/10.3390/pharmaceutics13040468.

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Inkjet printing is novel approach in drug manufacturing that enables dispensing precise volumes of ink onto substrates. Optimal substrate properties including suitable mechanical characteristic are recognized as crucial to achieve desired dosage form performance upon administration. Identification of relevant quality attributes and their quantification is subject of intensive scientific research. The aim of this work was to explore applicability of different materials as printing substrates and explore contribution of the investigated substrate properties to its printability. Substrates were characterized with regards to uniformity, porosity, disintegration time, mechanical properties and drug dissolution. Experimentally obtained values were mathematically transformed and the obtained results were presented as relevant radar charts. It was shown that structurally different substrates may be employed for orodispersible films inkjet printing. Main disadvantage of single-polymer films was low drug load, and their printability was dependent on film flexibility and mechanical strength. Structured orodispersible film templates exhibited favorable mechanical properties and drug load capacity. Wafer edible sheets were characterized with high mechanical resistance and brittleness which somewhat diminished printability, but did not hinder high drug load. Obtained results provide insight into application of different materials as printing substrates and contribute to understanding of substrate properties which can affect printability.

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36

Pal, Sunil K., Youngsuk Son, Theodorian Borca-Tasciuc, Diana-Andra Borca-Tasciuc, Swastik Kar, Robert Vajtai, and Pulickel M. Ajayan. "Thermal and electrical transport along MWCNT arrays grown on Inconel substrates." Journal of Materials Research 23, no. 8 (August 2008): 2099–105. http://dx.doi.org/10.1557/jmr.2008.0256.

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This work reports on thermal and electrical conductivities and interface resistances for transport along aligned multiwalled carbon nanotubes (CNT) films grown on a nickel superalloy (Inconel) substrate. The measured specific thermal resistance of the combined Inconel–CNT and indium–CNT interfaces is of the same order as reported for CNT and silicon or SiO2 interfaces but much higher than theoretical predictions considering perfect contact between the tubes and substrate. Imperfect mechanical contact with the substrate and a large contribution caused by indium–CNT interface are thought to be mainly responsible for the high interface resistances and the low effective values of thermal and electrical conductivities. However, reported results represent an incentive for further research on CNT synthesis on metallic substrates for thermal management applications and pave the way for much easier integration of carbon nanotubes in electronic applications.

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37

BAICI, Antonio, Stefan E. SZEDLACSEK, Hans FRÜH, and Beat A. MICHEL. "pH-dependent hysteretic behaviour of human myeloblastin (leucocyte proteinase 3)." Biochemical Journal 317, no. 3 (August 1, 1996): 901–5. http://dx.doi.org/10.1042/bj3170901.

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Human myeloblastin (leucocyte proteinase 3) showed a very slow approach to the steady-state velocity when the pH was rapidly increased from 3.2 to 7.0. The kinetic mechanism of this hysteretic process was interpreted as a slow conformational change of myeloblastin from an inactive form at acidic pH to the active form at neutral pH. The transition between the two enzyme forms could occur spontaneously in the absence of substrates with a first-order rate constant of 0.0033 s-1. In the presence of peptide substrates activation occurred more rapidly: the observed rate constant was linearly dependent upon the substrate concentration and contained a contribution of the spontaneous as well as of the substrate-dependent process, whose second-order rate constant was characteristic of the particular substrate. This pH-dependent phenomenon of hysteresis on the part of myeloblastin, that is not manifested by the closely related leucocyte elastase, may have a physiological control function during phagocytosis by damping the rate of interconversion between enzymically inactive and active enzyme conformations.

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38

Bai, Bing, Jin He, Yan-Shu Li, Xiu-Mei Wang, Hong-Jun Ai, and Fu-Zhai Cui. "Activation of the ERK1/2 Signaling Pathway during the Osteogenic Differentiation of Mesenchymal Stem Cells Cultured on Substrates Modified with Various Chemical Groups." BioMed Research International 2013 (2013): 1–15. http://dx.doi.org/10.1155/2013/361906.

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The current study examined the influence of culture substrates modified with the functional groups –OH, –COOH, –NH2, and –CH3using SAMs technology, in conjunction with TAAB control, on the osteogenic differentiation of rabbit BMSCs. The CCK-8 assay revealed that BMSCs exhibited substrate-dependent cell viability. The cells plated on –NH2- and –OH-modified substrates were well spread and homogeneous, but those on the –COOH- and –CH3-modified substrates showed more rounded phenotype. The mRNA expression of BMSCs revealed that –NH2-modified substrate promoted the mRNA expression and osteogenic differentiation of the BMSCs. The contribution of ERK1/2 signaling pathway to the osteogenic differentiation of BMSCs cultured on the –NH2-modified substrate was investigatedin vitro. The –NH2-modified substrate promoted the expression of integrins; the activation of FAK and ERK1/2. Inhibition of ERK1/2 activation by PD98059, a specific inhibitor of the ERK signaling pathway, blocked ERK1/2 activation in a dose-dependent manner, as revealed for expression of Cbfα-1 and ALP. Blockade of ERK1/2 phosphorylation in BMSCs by PD98059 suppressed osteogenic differentiation on chemical surfaces. These findings indicate a potential role for ERK in the osteogenic differentiation of BMSCs on surfaces modified by specific chemical functional groups, indicating that the microenvironment affects the differentiation of BMSCs. This observation has important implications for bone tissue engineering.

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Binsker, Ulrike, Thomas P. Kohler, and Sven Hammerschmidt. "Contribution of Human Thrombospondin-1 to the Pathogenesis of Gram-Positive Bacteria." Journal of Innate Immunity 11, no. 4 (2019): 303–15. http://dx.doi.org/10.1159/000496033.

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A successful colonization of different compartments of the human host requires multifactorial contacts between bacterial surface proteins and host factors. Extracellular matrix proteins and matricellular proteins such as thrombospondin-1 play a pivotal role as adhesive substrates to ensure a strong interaction with pathobionts like the Gram-positive Streptococcus pneumoniae and Staphylococcus aureus. The human glycoprotein thrombospondin-1 is a component of the extracellular matrix and is highly abundant in the bloodstream during bacteremia. Human platelets secrete thrombospondin-1, which is then acquired by invading pathogens to facilitate colonization and immune evasion. Gram-positive bacteria express a broad spectrum of surface-exposed proteins, some of which also recognize thrombospondin-1. This review highlights the importance of thrombospondin-1 as an adhesion substrate to facilitate colonization, and we summarize the variety of thrombospondin-1-binding proteins of S. pneumoniae and S. aureus.

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40

Shi-yi, Lun, and Chen Jian. "The contribution of interspecies hydrogen transfer to the substrate removal in methanogenesis." Process Biochemistry 27, no. 5 (September 1992): 285–89. http://dx.doi.org/10.1016/0032-9592(92)85013-r.

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41

Manios, E., D. Stamopoulos, N. Moutis, M. Pissas, and D. Niarchos. "Magnetic measurements in thin film specimens: Rejecting the contribution of the substrate." Journal of Magnetism and Magnetic Materials 320, no. 23 (December 2008): 3264–71. http://dx.doi.org/10.1016/j.jmmm.2008.06.020.

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42

Wilkens, Matthias, and Sriram Krishnaswamy. "The Contribution of Factor Xa to Exosite-dependent Substrate Recognition by Prothrombinase." Journal of Biological Chemistry 277, no. 11 (January 8, 2002): 9366–74. http://dx.doi.org/10.1074/jbc.m110848200.

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Rajak, Abdul, Tri Siswandi Syahputra, Muhammad Miftahul Munir, and K. Khairurrijal. "The Effect of Nonwoven Microfiber Substrate Polypropylene Thickness to Air Filtration Performance of Polyacrilonitrille Nanofiber." Jurnal ILMU DASAR 20, no. 2 (July 16, 2019): 95. http://dx.doi.org/10.19184/jid.v20i2.9658.

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Since a nanofiber medium on itself is soft and fragile and cannot be used alone as air filters. Coating nanofiber on a rigid substrate to form a composite that can be handled readily is necessary. Beside can improve the filtration efficiency, adding the substrate will also save the use of nanofibers mat itself. The aim of this study is to evaluate the effect of substrate thickness on the performance of nanofibers mat in aerosol filtration in order to find the optimum thickness of substrate that can increase the quality of nanofiber filter. The substrate used was a low cost microfiber non-woven fabric made from polypropylene (PP). The nanofibers mat was composed of electrospun polyacrylonitrile (PAN) with concentration of 9 wt.% which dissolved at N,N dimethylformamide (DMF). Five variations of PP different in thickness was used as substrate. From the SEM image, it was found that there is increasing fiber diameter of PAN after electrospun into PP substrate. From the porosity estimation of each nanofiber, it was found that the porosity decreased with increasing the substrate thickness. For test the performance of nanofiber filter, the particles of polystyrene latex (PSL) which generated by atomizer was used as the aerosol particle. In addition, to evaluate the performance filter in PM2.5 filtration, the experiment was carried out with generate the smoke from burning incense. Air filtration performance of all variations is obtained by comparison the results of measurement including: pressure drop, efficiency and quality factor. From the results, there is limitation on the substrates thickness based on the value of the quality factor obtained. Overall, PP nonwoven as the substrates gives the great contribution on the efficiency of PAN nanofiber. Keywords: substrate, polypropylene, thickness, nanofiber, air filtration.

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Jech, David, Ladislav Čelko, Lenka Klakurková, Karel Slámečka, Miroslava Horynová, and Jiří Švejcar. "Formation of Thermally Sprayed Coatings on Grid-Like Structure Substrate." Solid State Phenomena 258 (December 2016): 387–90. http://dx.doi.org/10.4028/www.scientific.net/ssp.258.387.

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The main goal of this contribution is to investigate the influence of the substrate morphology on the resulting thermally sprayed coatings microstructure. Therefore, three different representative coating systems and/or thermal spray techniques were utilized to produce the coatings on grid-like structure substrates: (i) CoNiCrAlY bond coat (BC) sprayed by high velocity oxygen fuel (HVOF) technique and yttria stabilized zirconia (YSZ) top coat (TC) sprayed by means of atmospheric plasma spray (APS) technique, (ii) YSZ coating sprayed by means of APS and (iii) YSZ coating sprayed by means of nanoparticle colloid suspension plasma spraying (SPS). The shadowing effect of thermal spray coatings in relation with the grid-like substrate structure was investigated in detail. Resulting microstructure of sprayed samples was studied utilizing light microscopy, digital image analysis, scanning electron microscopy, energy-dispersive spectrometer and X-ray diffraction techniques.

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Rao, M. Hema Lata, and Neti V. L. Narasimha Murty. "The Role of Substrate Compensation on DC Characteristics of 4H-SiC MESFET with Buffer Layer: A Combined Two-Dimensional Simulations and Analytical Study." Materials Science Forum 778-780 (February 2014): 887–90. http://dx.doi.org/10.4028/www.scientific.net/msf.778-780.887.

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An analytical model of 4H-SiC metal semiconductor field effect transistor (MESFET) is proposed with buffer layer on high purity semi-insulating (HPSI) 4H-SiC substrate compensated by multiple deep level traps. The contribution of deep level traps (DLT) is projected and verified using two-dimensional simulations (Silvaco®). The modeled DC characteristics are compared with two-dimensional simulations performed on the same device as considered in the analytical model.The 4H-SiC MESFET is simulated with and without the effect of buffer layer and the electron concentration profiles in different regions are observed from two-dimensional simulations.The electron concentration profiles obtained at channel-substrate interface clearly shows that when the buffer layer is not present, the channel electrons get trapped by the deep level traps used for substrate compensation. It is also observed that the inclusion of buffer layer minimizes the extent of electron trapping by screening out the active channel from the substrate. However, the trapping phenomena take place in both the cases.We believe that the proposed model of 4H-SiC MESFET which includes the substrate compensation through multiple deep level traps may be useful for realizing SiC based monolithic circuits (MMICs) on HPSI substrates.

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Nagle, Julie A., Zhefu Ma, Maura A. Byrne, Morris F. White, and Leslie M. Shaw. "Involvement of Insulin Receptor Substrate 2 in Mammary Tumor Metastasis." Molecular and Cellular Biology 24, no. 22 (November 15, 2004): 9726–35. http://dx.doi.org/10.1128/mcb.24.22.9726-9735.2004.

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ABSTRACT The insulin receptor substrate (IRS) proteins are adaptor molecules that integrate signals generated by receptors that are implicated in human breast cancer. We investigated the specific contribution of IRS-2 to mammary tumor progression using transgenic mice that express the polyoma virus middle T antigen (PyV-MT) in the mammary gland and IRS-2-null (IRS-2−/−) mice. PyV-MT-induced tumor initiation and growth were similar in wild-type (WT) and IRS-2−/− mice. However, the latency and incidence of metastasis were significantly decreased in the absence of IRS-2 expression. The contribution of IRS-2 to metastasis is intrinsic to the tumor cells, because IRS-2−/− mammary tumor cells did not metastasize when grown orthotopically in the mammary fat pads of WT mice. WT and IRS-2−/− tumors contained similar numbers of mitotic cells, but IRS-2−/− tumors had a higher incidence of apoptosis than did WT tumors. In vitro, IRS-2−/− mammary tumor cells were less invasive and more apoptotic in response to growth factor deprivation than their WT counterparts. In contrast, IRS-1−/− tumor cells, which express only IRS-2, were highly invasive and were resistant to apoptotic stimuli. Collectively, our findings reveal an important contribution of IRS-2 to breast cancer metastasis.

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CHANG, CUI-ZU, KE HE, LI-LI WANG, XU-CUN MA, MIN-HAO LIU, ZUO-CHENG ZHANG, XI CHEN, YA-YU WANG, and QI-KUN XUE. "GROWTH OF QUANTUM WELL FILMS OF TOPOLOGICAL INSULATOR Bi2Se3 ON INSULATING SUBSTRATE." SPIN 01, no. 01 (June 2011): 21–25. http://dx.doi.org/10.1142/s2010324711000033.

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Insulating substrates are crucial for electrical transport study and room-temperature application of topological insulator films at thickness of only several nanometers. High-quality quantum well films of Bi 2 Se 3, a typical three-dimensional topological insulator, have been grown on α- Al 2 O 3 (sapphire) (0001) by molecular beam epitaxy. The films exhibit well-defined quantum well states and surface states, suggesting the uniform thickness over macroscopic area. The Bi 2 Se 3 thin films on sapphire (0001) provide a good system to study low-dimensional physics of topological insulators since conduction contribution from the substrate is negligibly small.

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Naylor, S., J. Brisson, M. A. Labelle, A. Drizo, and Y. Comeau. "Treatment of freshwater fish farm effluent using constructed wetlands: the role of plants and substrate." Water Science and Technology 48, no. 5 (September 1, 2003): 215–22. http://dx.doi.org/10.2166/wst.2003.0324.

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Freshwater fish farm effluents have low nutrient concentrations but high flow rates, resulting in a pollutant load, especially phosphorus (P), causing eutrophication. The feasibility was tested of a treatment combining, within a single constructed wetland, the contribution of macrophytes for reducing organic matter and nitrogen (N), with the high efficiency of steel slag and limestone for P removal. Twenty subsurface flow (SSF) basins of 280 L with different combinations of plants (Phragmites communis or Typha latifolia) and substrates (steel slag, limestone, gravel, peat) were fed with a reconstituted fish farm effluent in a greenhouse experiment. Pollutant removal was generally very good under all treatments. N and organic matter removal were correlated with plant biomass while P removal was better in substrates with steel slag and limestone. However, the high pH of the P-adsorbing substrate was detrimental to plant growth so that no combination of plants and substrates could maximise in one step the simultaneous removal of all evaluated pollutants. Therefore, the use of two sequential units is recommended, a first one consisting of a macrophyte planted basin using a neutral substrate to remove organic matter and N, followed by a second unplanted basin containing only a P-adsorbing substrate.

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Myears, D. W., B. E. Sobel, and S. R. Bergmann. "Substrate use in ischemic and reperfused canine myocardium: quantitative considerations." American Journal of Physiology-Heart and Circulatory Physiology 253, no. 1 (July 1, 1987): H107—H114. http://dx.doi.org/10.1152/ajpheart.1987.253.1.h107.

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The patterns of use of substrate in reperfused myocardium are not yet well elucidated, and their delineation is essential for adequate interpretation of results of analyses performed after positron emission tomography with labeled substrates to differentiate normal from abnormal heart muscle. Accordingly, in open-chest, anesthetized dogs we measured glucose and fatty acid utilization in normal, ischemic, and reperfused myocardium and assessed the contributions of metabolism of each substrate to overall oxidative metabolism. Intracoronary [3H]glucose and [14C]palmitate were administered in five control dogs, eight dogs subjected to 1 h of coronary occlusion, and nine dogs subjected to reperfusion after 1 h of ischemia. Regional coronary venous blood samples were assayed sequentially. In reperfused myocardium, utilization of glucose (463 +/- 88 nmol X g-1 X min-1) was 103% greater than that in ischemic and 273% greater than in normal myocardium (P less than 0.05 for each). Utilization of fatty acid during reperfusion (55 +/- 10 nmol X g-1 X min-1), although greater than that in ischemic myocardium, was significantly less than that in normal myocardium (48% of control, P less than 0.05) despite restoration of flow to 80% of control values. Although glucose constituted 70% of the substrate oxidized in ischemic myocardium, its contribution to overall oxidative metabolism in reperfused myocardium was only 25%. In contrast, despite diminished net uptake of fatty acid, oxidation of fatty acid accounted for 63% of total oxygen consumption in reperfused myocardium. These studies indicate that canine myocardium reperfused after 1 h of ischemia exhibits enhanced uptake of glucose and impaired utilization of palmitate.(ABSTRACT TRUNCATED AT 250 WORDS)A

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Antunes, Jorge M., Nataliya A. Sakharova, José Valdemar Fernandes, and Luís Filipe Menezes. "Strain and Stress Distribution in Vickers Indentation of Coated Materials." Materials Science Forum 514-516 (May 2006): 1472–76. http://dx.doi.org/10.4028/www.scientific.net/msf.514-516.1472.

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Depth sensing indentation equipment allows the mechanical properties of thin films to be easily determined, particularly the hardness and Young’s modulus. In order to minimize the influence of the substrate on the measured properties, the indentation depth must be limited to a small fraction of the film’s thickness. However, for very thin films, the determination of the contribution of the substrate and the film to the measured mechanical properties becomes a hard task, because both deform plastically. The numerical simulation of ultramicrohardness tests can be a helpful tool towards better understanding of the influence of the parameters involved in the mechanical characterization of thin films. For this purpose, a three-dimensional numerical simulation home code, HAFILM, was used to simulate ultramicrohardness tests on coated substrates. Materials with different Young’s modulus film/substrate ratios were tested. Analyses of strain and stress distributions for several indentation depth values were performed, in order to clarify the composite behaviour.

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Journal articles on the topic 'Substrate contribution'

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