Articles de revues : « Substrats II-VI »

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ZAHN, DIETRICH R. T. « PROBING SURFACES AND INTERFACES WITH OPTICAL TECHNIQUES ». Surface Review and Letters 01, n^o 04 (décembre 1994) : 421–28. http://dx.doi.org/10.1142/s0218625x94000382.

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The potential of optical techniques for probing semiconductor surfaces and interfaces is discussed using the example of Raman spectroscopy. The surface sensitivity of the technique is demonstrated by the detection of vibrational modes of atomic monolayers on semiconductor substrates, for instance arsenic on silicon(111). The special feature of Raman spectroscopy, namely its chemical sensivity, is illustrated by two examples: the interdiffusion of group III overlayers, e.g., In on the group V substrate Sb and the detection of reacted layers at II–VI/III– V heterointerfaces. The example of II–VI/III–V heteroepitaxy also serves as an example for demonstrating the growth monitoring capabilities of optical techniques.

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Naugle, Jennifer E., Erik R. Olson, Xiaojin Zhang, Sharon E. Mase, Charles F. Pilati, Michael B. Maron, Hans G. Folkesson, Walter I. Horne, Kathleen J. Doane et J. Gary Meszaros. « Type VI collagen induces cardiac myofibroblast differentiation : implications for postinfarction remodeling ». American Journal of Physiology-Heart and Circulatory Physiology 290, n^o 1 (janvier 2006) : H323—H330. http://dx.doi.org/10.1152/ajpheart.00321.2005.

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Cardiac fibroblast (CF) proliferation and differentiation into hypersecretory myofibroblasts can lead to excessive extracellular matrix (ECM) production and cardiac fibrosis. In turn, the ECM produced can potentially activate CFs via distinct feedback mechanisms. To assess how specific ECM components influence CF activation, isolated CFs were plated on specific collagen substrates (type I, III, and VI collagens) before functional assays were carried out. The type VI collagen substrate potently induced myofibroblast differentiation but had little effect on CF proliferation. Conversely, the type I and III collagen substrates did not affect differentiation but caused significant induction of proliferation (type I, 240.7 ± 10.3%, and type III, 271.7 ± 21.8% of basal). Type I collagen activated ERK1/2, whereas type III collagen did not. Treatment of CFs with angiotensin II, a potent mitogen of CFs, enhanced the growth observed on types I and III collagen but not on the type VI collagen substrate. Using an in vivo model of myocardial infarction (MI), we measured changes in type VI collagen expression and myofibroblast differentiation after post-MI remodeling. Concurrent elevations in type VI collagen and myofibroblast content were evident in the infarcted myocardium 20-wk post-MI. Overall, types I and III collagen stimulate CF proliferation, whereas type VI collagen plays a potentially novel role in cardiac remodeling through facilitation of myofibroblast differentiation.

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Jones, K. M., F. S. Hasoon, A. B. Swartzlander, M. M. Al-Jassim, T. L. Chu et S. S. Chu. « The morphology and microstructure of polycrystalline CdTe thin films for solar cell applications ». Proceedings, annual meeting, Electron Microscopy Society of America 50, n^o 2 (août 1992) : 1384–85. http://dx.doi.org/10.1017/s0424820100131553.

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Polycrystalline thin films of II-VI semiconductors on foreign polycrystalline (or amorphous) substrates have many applications in optoelectronic devices. In contrast to the extensive studies of the heteroepitaxial growth of compound semiconductors on single-crystal substrates, the nucleation and growth of thin films of II-VI compounds on foreign substrates have received little attention, and the properties of these films are often controlled empirically to optimize device performance. A better understanding of the nucleation, growth, and microstructure will facilitate a better control of the structural and electrical properties of polycrystalline semiconductor films, thereby improving the device characteristics. Cadmium telluride (CdTe) has long been recognized as a promising thin-film photovoltaic material. Under NREL's sponsorship, the University of South Florida has recently developed a record high efficiency (14.6% under global AM1.5 conditions) thin-film CdS/CdTe heterojunction solar cell for potential low-cost photovoltaic applications. The solar cell has the structure:glass (substrate)/SnO2:F/CdS/CdTe/HgTe (contact)The CdS films were grown from an aqueous solution, while the CdTe films were deposited by the closespaced sublimation method.

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Sato, K., Y. Seki, Y. Matsuda et O. Oda. « Recent developments in II–VI substrates ». Journal of Crystal Growth 197, n^o 3 (février 1999) : 413–22. http://dx.doi.org/10.1016/s0022-0248(98)00739-8.

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Wang, Jiawei, Jiahui Li, Yi Hou, Wei Dai, Ruopeng Xie, Tatiana T. Marquez-Lago, André Leier et al. « BastionHub : a universal platform for integrating and analyzing substrates secreted by Gram-negative bacteria ». Nucleic Acids Research 49, n^o D1 (21 octobre 2020) : D651—D659. http://dx.doi.org/10.1093/nar/gkaa899.

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Abstract Gram-negative bacteria utilize secretion systems to export substrates into their surrounding environment or directly into neighboring cells. These substrates are proteins that function to promote bacterial survival: by facilitating nutrient collection, disabling competitor species or, for pathogens, to disable host defenses. Following a rapid development of computational techniques, a growing number of substrates have been discovered and subsequently validated by wet lab experiments. To date, several online databases have been developed to catalogue these substrates but they have limited user options for in-depth analysis, and typically focus on a single type of secreted substrate. We therefore developed a universal platform, BastionHub, that incorporates extensive functional modules to facilitate substrate analysis and integrates the five major Gram-negative secreted substrate types (i.e. from types I–IV and VI secretion systems). To our knowledge, BastionHub is not only the most comprehensive online database available, it is also the first to incorporate substrates secreted by type I or type II secretion systems. By providing the most up-to-date details of secreted substrates and state-of-the-art prediction and visualized relationship analysis tools, BastionHub will be an important platform that can assist biologists in uncovering novel substrates and formulating new hypotheses. BastionHub is freely available at http://bastionhub.erc.monash.edu/.

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KERN, András, Zsófia SZENTPÉTERY, Károly LILIOM, Éva BAKOS, Balázs SARKADI et András VÁRADI. « Nucleotides and transported substrates modulate different steps of the ATPase catalytic cycle of MRP1 multidrug transporter ». Biochemical Journal 380, n^o 2 (1 juin 2004) : 549–60. http://dx.doi.org/10.1042/bj20031607.

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The human ABC (ATP-binding cassette) transporter MRP1 (human multidrug-resistance-associated protein 1; ABCC1) is involved in the cellular extrusion of conjugated metabolites and causes multidrug resistance in tumour cells. The transport of substrate molecules by ABC proteins is energized by ATP hydrolysis, performed by two co-operating ABC units. Orthovanadate (Vi), a non-covalent inhibitor of the ABC ATPases, was found to catalyse a photo-oxidative cleavage of various ATP-binding proteins. In the present study, we have identified three Vi-cleavage sites within MRP1, and found that the cleavage reactions were variably modulated by the presence of nucleotides and by transported substrates. We concluded that Vi cleavage of MRP1 at Site I detects conformational changes due to the binding of MgATP. In contrast, Site II could be identified as part of the substrate-modulated catalytic cycle, probably containing an MRP1·MgADP·Vi transition-state-like complex. Cleavage at Site III was modulated by both the binding and hydrolysis of MgATP, in a biphasic pattern, which was also affected by the presence of transported substrates. We detected two different allosteric effects and found that they control two consecutive steps of the MRP1 ATPase catalytic cycle. Nucleotide binding to the low-affinity site accelerated the formation of the pre-hydrolytic intermediate in the other catalytic centre. Interaction of the transporter with its transported substrates stimulated a later reaction of the hydrolytic cycle, the formation of the post-hydrolytic intermediate, which could be detected in both catalytic sites by the experimental strategy used.

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Staudenmann, J. L., R. D. Horning et R. D. Knox. « Buerger precession camera and overall characterization of thin films and flat-plate crystals ». Journal of Applied Crystallography 20, n^o 3 (1 juin 1987) : 210–21. http://dx.doi.org/10.1107/s0021889887086813.

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A fast simple and non-destructive method is described to provide qualitative structural information for flat-plate crystals and epitaxically grown films. The technique, based upon the Buerger precession camera, produces an easy-to-interpret photograph of the reciprocal space of all the components at once: substrate, film or buffer layer, and/or superlattice. A wide variety of technologically important examples are used to illustrate the technique: a mixture of CdTe phases on (001) Si, an aluminium layer on a (001) Si substrate, (001) Ge epitaxic layers on (001) Si substrates, three combinations of possible orientations of CdTe epitaxic layers on various substrate types, CdTe/ZnTe and other II–VI superlattices on GaAs substrates. In addition, the precession pictures readily reveal the common [111] face-centered cubic twin fault, or stacking disorder, seen in bulk growth methods. This finding may have severe consequences for the electronic mobility and the feasibility of devices fabricated from these composite systems.

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Brockhausen, Inka, Jeremy P. Carver et Harry Schachter. « Control of glycoprotein synthesis. The use of oligosaccharide substrates and HPLC to study the sequential pathway for N-acetylglucosaminyltransferases I, II, III, IV, V, and VI in the biosynthesis of highly branched N-glycans by hen oviduct membranes ». Biochemistry and Cell Biology 66, n^o 10 (1 octobre 1988) : 1134–51. http://dx.doi.org/10.1139/o88-131.

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Glycoproteins isolated from hen oviduct contain highly branched asparagine-linked oligosaccharides (N-glycans). Six N-acetylglucosaminyltransferases (GlcNAc-T I, II, III, IV, V, and VI) are involved in initiating the synthesis of these branches, as indicated below:[Formula: see text]where R is GlcNAcβ1—4(+/−Fucα1—6)GlcNAcAsn-X. HPLC has been used to study the substrate specificities of these GlcNAc-T and the sequential pathways involved in the biosynthesis of highly branched N-glycans in hen oviduct. Oligosaccharides with free reducing GlcNAc termini were prepared from various glycoproteins by hydrazinolysis–re-N-acetylation and used as GlcNAc-T substrates and HPLC standards. Enzyme assay components were separated on AG1 × 8, followed by HPLC on amine-bonded silica columns eluted with acetonitrile–water mixtures. Absorbance at 195 nm and radioactivity of eluted compounds were monitored. Substrates and products were identified by comparison of their retention times with those of oligosaccharides with known structures. Enzyme assay by HPLC is more rapid and convenient than previous GlcNAc-T assays using lectin columns or electrophoresis. Since some substrates yielded multiple products, these could be used to assay more than one GlcNAc-T in the same incubation. GlcNAc-T VI was shown to act on both bisected and nonbisected GlcNAc-terminating tetraantennary oligosaccharide substrates; GlcNAc-T II, IV, and V acted poorly or not at all on bisected substrates. GlcNAc-T V was the only enzyme among the six transferases studied that could be assayed in the absence of Mn2+.

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Witt, Katarzyna, Waldemar Studziński et Daria Bożejewicz. « Possibility of New Active Substrates (ASs) to Be Used to Prevent the Migration of Heavy Metals to the Soil and Water Environments ». Molecules 28, n^o 1 (22 décembre 2022) : 94. http://dx.doi.org/10.3390/molecules28010094.

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This paper aims to propose an alternative to the known permeable reactive barriers (PRBs). PRB is one of the methods, which is a reactive barrier placed below the ground, to clean up contaminated groundwater. New polymer active substrates (ASs) were used to prevent soil contamination by toxic heavy metals. The active substrates consisted of a mixture of poly(vinyl chloride), Aliquat 336, and bis(2-ethylhexyl)adipate, which was applied to the skeleton material (fiberglass or textile). Aliquat 336 was used as a binding agent for metal ions (Cr(VI), Ni(II), Cu(II), Zn(II), Cd(II), and Pb(II)). In contrast with the PRBs, the ASs (from AS-1 to AS-5) were obtained in a simple way using the pouring method. The obtained ASs could be recycled and reused. The active substrates were used for the binding of various metal ions from aqueous solutions and the examined soil. It was found that the active substrate AS-1 decreased the concentrations of nickel, cadmium, and lead by more than 50% and that of chromium by more than 90% in the aqueous solution. High sorption efficiency for chromium and zinc metals (81% and 66%) with the use of AS-2 was also found, owing to which the migration of metals from soil to water can be limited. In the soil environment, active substrate AS-5 with the addition of a plasticizer showed the greatest effectiveness. This solution resulted in a reduction in each tested metal ion of at least 50%, and reductions in cadmium, lead, and copper of over 70%.

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Ernst, K., I. Sieber, M. Neumann-Spallart, M. Ch Lux-Steiner et R. Könenkamp. « Characterization of II–VI compounds on porous substrates ». Thin Solid Films 361-362 (février 2000) : 213–17. http://dx.doi.org/10.1016/s0040-6090(99)00836-6.

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Kumar, Arun Babu, Sophia Masi, Farideh Ghomashchi, Naveen Kumar Chennamaneni, Makoto Ito, C. Ronald Scott, Frantisek Turecek, Michael H. Gelb et Zdenek Spacil. « Tandem Mass Spectrometry Has a Larger Analytical Range than Fluorescence Assays of Lysosomal Enzymes : Application to Newborn Screening and Diagnosis of Mucopolysaccharidoses Types II, IVA, and VI ». Clinical Chemistry 61, n^o 11 (1 novembre 2015) : 1363–71. http://dx.doi.org/10.1373/clinchem.2015.242560.

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Abstract BACKGROUND There is interest in newborn screening and diagnosis of lysosomal storage diseases because of the development of treatment options that improve clinical outcome. Assays of lysosomal enzymes with high analytical range (ratio of assay response from the enzymatic reaction divided by the assay response due to nonenzymatic processes) are desirable because they are predicted to lead to a lower rate of false positives in population screening and to more accurate diagnoses. METHODS We designed new tandem mass spectrometry (MS/MS) assays that give the largest analytical ranges reported to date for the use of dried blood spots (DBS) for detection of mucopolysaccharidoses type II (MPS-II), MPS-IVA, and MPS-VI. For comparison, we carried out fluorometric assays of 6 lysosomal enzymes using 4-methylumbelliferyl (4MU)-substrate conjugates. RESULTS The MS/MS assays for MPS-II, -IVA, and -VI displayed analytical ranges that are 1–2 orders of magnitude higher than those for the corresponding fluorometric assays. The relatively small analytical ranges of the 4MU assays are due to the intrinsic fluorescence of the 4MU substrates, which cause high background in the assay response. CONCLUSIONS These highly reproducible MS/MS assays for MPS-II, -IVA, and -VI can support multiplex newborn screening of these lysosomal storage diseases. MS/MS assays of lysosomal enzymes outperform 4MU fluorometric assays in terms of analytical range. Ongoing pilot studies will allow us to gauge the impact of the increased analytical range on newborn screening performance.

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Garcia, J. A., A. Remón, V. Munñz et R. Triboulet. « Annealing-induced Changes in the Electronic and Structural Properties of ZnTe Substrates ». Journal of Materials Research 15, n^o 7 (juillet 2000) : 1612–16. http://dx.doi.org/10.1557/jmr.2000.0231.

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The aim of this study is to demonstrate that the electronic and structural properties of II–VI substrates, here ZnTe, can be dramatically affected by thermal heating at temperatures in the range of those typically used in the epitaxial metalorganic chemical vapor deposition processes. Photoluminescence response shows that annealing at these temperatures produces a reduction of the sample crystalline quality, decreasing the free exciton emission relative to the deep level related one. Some factors, like the change in the charge and stress state of dislocations, Cu diffusion, and oxygen incorporation, could be responsible for changes in the substrate properties, which can produce stresses and contamination in the deposited sample.

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MONAICO, Eduard V. « MICRO- AND NANO-ENGINEERING OF SEMICONDUCTOR COMPOUNDS AND METAL STRUCTURES BASED ON ELECTROCHEMICAL TECHNOLOGIES ». Annals of the Academy of Romanian Scientists Series on Physics and Chemistry 9, n^o 1 (30 août 2024) : 85–107. http://dx.doi.org/10.56082/annalsarsciphyschem.2024.1.85.

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This paper aims to address the challenges of micro- and nano-engineering semiconductor compounds and fabricating metal-semiconductor nanocomposite materials by developing theoretical concepts for the application of electrochemical nanostructuring technologies to semiconductor substrates. It includes identifying the technological conditions for controlled electrochemical etching to create nanostructured semiconductor templates with wide bandgaps, such as III-V semiconductors (InP, GaAs, GaN) and II-VI compounds (CdSe, ZnSe, ZnxCd1-xS). The study also demonstrates the conditions for electrochemical metal deposition in porous semiconductor templates and investigates the laws and mechanisms of metal deposition depending on the composition of the semiconductor substrates and current pulse parameters. Additionally, the paper addresses the conditions for electrochemical etching of semiconductor substrates to produce nanowire networks with directed alignment to the substrate surface, instead of merely producing porous layers. A comprehensive investigation of the properties of the developed nanostructures and materials is proposed to demonstrate their applicability in nanoelectronic, optoelectronic, and photonic devices.

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Belyaev, A. P., et V. P. Rubets. « Heteroepitaxy of II-VI compound semiconductors on cooled substrates ». Semiconductors 35, n^o 3 (mars 2001) : 279–82. http://dx.doi.org/10.1134/1.1356146.

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Boney, C. « II–VI blue/green laser diodes on ZnSe substrates ». Journal of Vacuum Science & ; Technology B : Microelectronics and Nanometer Structures 14, n^o 3 (mai 1996) : 2259. http://dx.doi.org/10.1116/1.588914.

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Cywiński, G., T. Wojtowicz, K. Kopalko, G. Karczewski et J. Kossut. « Epitaxial Growths of II-VI Compounds on (110) Substrates ». Acta Physica Polonica A 94, n^o 2 (août 1998) : 281–84. http://dx.doi.org/10.12693/aphyspola.94.281.

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Thompson, J., K. T. Woodhouse et C. Dineen. « Epitaxial growth of II–VI compounds on sapphire substrates ». Journal of Crystal Growth 77, n^o 1-3 (septembre 1986) : 452–59. http://dx.doi.org/10.1016/0022-0248(86)90336-2.

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Schikora, D., H. Hausleitner, S. Einfeldt, C. R. Becker, Th Widmer, C. Giftge, K. Lübke, K. Lischka, M. von Ortenberg et G. Landwehr. « Epitaxial overgrowth of II–VI compounds on patterned substrates ». Journal of Crystal Growth 138, n^o 1-4 (avril 1994) : 8–13. http://dx.doi.org/10.1016/0022-0248(94)90772-2.

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Brill, Gregory N., Yuanping Chen, Priyalal S. Wijewarnasuriya et Nibir K. Dhar. « Hg based II-VI compounds on non-standard substrates ». physica status solidi (a) 209, n^o 8 (20 juin 2012) : 1423–27. http://dx.doi.org/10.1002/pssa.201100734.

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KOUMANOV, Kamen, Claude WOLF et Gilbert BÉREZIAT. « Modulation of human type II secretory phospholipase A2 by sphingomyelin and annexin VI ». Biochemical Journal 326, n^o 1 (15 août 1997) : 227–33. http://dx.doi.org/10.1042/bj3260227.

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Conjectural results have been reported on the capacity of inflammatory secreted phospholipase A2 (sPLA2) to hydrolyse mammalian membrane phospholipids. Development of an assay based on the release of non-esterified fatty acids by the enzyme acting on the organized phospholipid mixture constituting the membrane matrix has led to the identification of two prominent effectors, sphingomyelin (SPH) and annexin. Recombinant human type II sPLA2 hydrolyses red-cell membrane phospholipids with a marked preference for the inner leaflet. This preference is apparently related to the high content of SPH in the outer leaflet, which inhibits sPLA2. This inhibition by SPH is specific for sPLA2. Cholesterol counteracts the inhibition of sPLA2 by SPH, suggesting that the SPH-to-cholesterol ratio accounts in vivo for the variable susceptibility of cell membranes to sPLA2. Different effects were observed of the presence of the non-hydrolysable D-α-dipalmitoyl phosphatidylcholine (D-DPPC), which renders the membranes rigid but does not inhibit sPLA2. Annexin VI was shown, along with other annexins, to inhibit sPLA2 activity by sequestering the phospholipid substrate. The present study has provided the first evidence that annexin VI, in concentrations that inhibit hydrolysis of purified phospholipid substrates, stimulated the hydrolysis of membrane phospholipids by sPLA2. The activation requires the presence of membrane proteins. The effect is specific for type II sPLA2 and is not reproducible with type I PLA2. The activation by annexin VI of sPLA2 acting on red cell membranes results in the preferential release of polyunsaturated fatty acids. It suggests that type II sPLA2, in conjunction with annexin VI, might be involved in the final step of endocytosis and/or exocytosis providing the free polyunsaturated fatty acids acting synergistically to cause membrane fusion.

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Santos, Daniele Bezerra dos, Fúlvio Aurélio de Morais Freire et Cibele Soares Pontes. « Comportamento do camarão em diferentes substratos nas fases clara e escura do dia ». Pesquisa Agropecuária Brasileira 48, n^o 8 (août 2013) : 841–48. http://dx.doi.org/10.1590/s0100-204x2013000800005.

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O objetivo deste trabalho foi avaliar o efeito do tipo de substrato sobre a preferência, o enterramento e a atividade natatória de camarões (Litopenaeus vannamei). Juvenis (0,93±0,29 g) e adultos machos e fêmeas (10,05±1,18 g) foram observados durante 24 horas, por meio do método animal focal, com registros instantâneos. Foram testadas as seguintes granulometrias (tratamentos) dos substratos: I, 100% C; II, 50% C + 50% B; III, 50% A + 50% C; IV, 100% B; V, 50% B + 50% A; e VI, 100% A, em que as letras referemse ao diâmetro médio das partículas, A = 0,25-2,0 mm; B = 0,0625-0,25 mm; e C = <0,0625 mm. Foram aplicados seis tratamentos com 18 repetições para cada categoria: camarões juvenis, machos e fêmeas. Cada indivíduo foi exposto por 24 horas aos seis tipos de substrato, simultaneamente, e o seu comportamento foi observado nas fases clara e escura do dia. A natação ocorreu principalmente na fase escura e o enterramento, na fase clara, no substrato IV. Os camarões juvenis e adultos (machos ou fêmeas) preferem o substrato composto de areia fina e muito fina (0,0625-0,25 mm), tanto para permanência quanto para enterramento.

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Suarez, Ernesto, Pik-Yiu Chan, Mukesh Gogna, John E. Ayers, Evan Heller et Faquir Jain. « ZNS/ZNMGSETE/ZNS II-VI Energy Barrier for INGAAS Substrates ». International Journal of High Speed Electronics and Systems 23, n^o 01n02 (mars 2014) : 1450013. http://dx.doi.org/10.1142/s012915641450013x.

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InGaAs high mobility transistors presently provide the fastest speeds. As InGaAs nonvolatile memory field effect transistors (NVMFETs) are scaled down past 22 nm gate width, threshold voltage variation becomes a limiting factor. Replacing the amorphous SiO 2 or HfO 2 with a heteroepitaxial barrier stack the threshold voltage can be stabilized by minimizing the interface charge at the barrier-channel interface. The floating gate is comprised of individually germanium-oxide cladded germanium quantum dots. The tunneling layer is comprised of a quantum well stack of ZnSe / ZnS / ZnMgSeTe / ZnS / ZnSe . The magnesium incorporation increases the the energy barrier but introduces dislocation that can leak charge. The ZnS and ZnSe layers have a lower bandgap but a lower dislocation density to assist with gate leakage prevention. We present simulation and experimental C-V data on InGaAs FET and II-VI tunneling layer on an InGaAs substrate respectively.

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Bieker, S., P. R. Hartmann, T. Kießling, M. Rüth, C. Schumacher, C. Gould, W. Ossau et L. W. Molenkamp. « Removal of GaAs growth substrates from II–VI semiconductor heterostructures ». Semiconductor Science and Technology 29, n^o 4 (26 février 2014) : 045016. http://dx.doi.org/10.1088/0268-1242/29/4/045016.

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Gupta, Avinash K., Ilya Zwieback, Andrew E. Souzis, Murugesu Yoganathan et Thomas Anderson. « Status of Large Diameter SiC Single Crystals at II-VI ». Materials Science Forum 600-603 (septembre 2008) : 35–38. http://dx.doi.org/10.4028/www.scientific.net/msf.600-603.35.

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II-VI is developing large-diameter SiC crystals to be used as lattice-matched, high thermal conductivity substrates for new generation GaN-based and SiC-based semiconductor devices. Large-diameter 6H SiC single crystals are grown at II-VI using our Advanced PVT sublimation growth process. Stable SI properties are achieved by compensation with vanadium, which results in high and spatially uniform resistivity, on the order of 1011 Ohm-cm. The quality of the presently grown 100 mm 6H SI substrates has been dramatically improved [1], and they are free of edge defects. Micropipe density in the 100 mm 6H SI substrates ranges from 2 to 8 cm-2 and dislocation density from 3·104 to 6·104 cm-2. X-ray rocking curves measured on as-sawn 100 mm 6H wafers showed edge-to-edge lattice curvature () between 0.1° and 0.3° and FWHM of the rocking curve between 50 and 100 arc-seconds

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Abdelkareem, Mohammad Ali, Samah Ibrahim Alshathri, Mohd Shahbudin Masdar et Abdul Ghani Olabi. « Adaptive Neuro-Fuzzy Inference System Modeling and Optimization of Microbial Fuel Cells for Wastewater Treatment ». Water 15, n^o 20 (12 octobre 2023) : 3564. http://dx.doi.org/10.3390/w15203564.

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Due to their toxicity, Cr(VI) levels are subject to strict legislation and regulations in various industries and environmental contexts. Effective treatment technologies are also being developed to decrease the negative impacts on human health and the environment by removing Cr(VI) from water sources and wastewater. As a result, it would be interesting to model and optimize the Cr(VI) removal processes, especially those under neutral pH circumstances. Microbial fuel cells (MFCs) have the capacity to remove Cr(VI), but additional research is needed to enhance their usability, increase their efficacy, and address issues like scalability and maintaining stable operation. In this research work, ANFIS modeling and artificial ecosystem optimization (AEO) were used to maximize Cr(VI) removal efficiency and the power density of MFC. First, based on measured data, an ANFIS model is developed to simulate the MFC performance in terms of the Cu(II)/Cr(VI) ratio, substrate (sodium acetate) concentration (g/L), and external resistance Ω. Then, using artificial ecosystem optimization (AEO), the optimal values of these operating parameters, i.e., Cu(II)/Cr(VI) ratio, substrate concentration, and external resistance, are identified, corresponding to maximum Cr(VI) removal efficiency and power density. In the ANFIS modeling stage of power density, the coefficient-of-determination is enhanced to 0.9981 compared with 0.992 (by ANOVA), and the RMSE is decreased to 0.4863 compared with 16.486 (by ANOVA). This shows that the modeling phase was effective. In sum, the integration between ANFIS and AEO increased the power density and Cr(VI) removal efficiency by 19.14% and 15.14%, respectively, compared to the measured data.

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Doğan, S., Y. Ayyildiz, M. Doğan, ü. Alan et M. E. Diken. « Characterisation of polyphenol oxidase from Melissa officinalis L. subsp. officinalis (lemon balm) ». Czech Journal of Food Sciences 31, No. 2 (18 avril 2013) : 156–65. http://dx.doi.org/10.17221/288/2011-cjfs.

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Polyphenol oxidase (PPO) from Melissa officinalis L. subsp. officinalis (lemon balm) was partially purified by ammonium sulphate precipitation and dialysis; and then it was characterised in detail in terms of pH and temperature optima, thermal stability, kinetic parameters, and inhibition properties. Based on experimental results, it was found out that (i) the optimum pH and temperature values of PPO were 6.5, 4.0, and 8.5 and 40, 50, and 60°C for catechol, 4-methylcatechol and pyrogallol substrates, respectively; (ii) the best substrate was pyrogallol due to the highest V<sub>max</sub>/K<sub>m</sub> value, followed by catechol and 4-methylcatechol; (iii) enzyme activity decreased due to heat denaturation of the enzyme with increasing temperature and inactivation time for all substrates; (vi) gallic acid and l-glutamic acid did not inhibit PPO; and (v) the most effective inhibitor was glutathione. Furthermore, the phenolic and protein contents of lemon balm extract were also determined according to the Folin-Ciocalteu and Bradford methods, respectively.  

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Zaumseil, Peter, Grzegorz Kozlowski, Yuji Yamamoto, Markus Andreas Schubert et Thomas Schroeder. « X-ray characterization of Ge dots epitaxially grown on nanostructured Si islands on silicon-on-insulator substrates ». Journal of Applied Crystallography 46, n^o 4 (7 juin 2013) : 868–73. http://dx.doi.org/10.1107/s0021889813003518.

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On the way to integrate lattice mismatched semiconductors on Si(001), the Ge/Si heterosystem was used as a case study for the concept of compliant substrate effects that offer the vision to be able to integrate defect-free alternative semiconductor structures on Si. Ge nanoclusters were selectively grown by chemical vapour deposition on Si nano-islands on silicon-on-insulator (SOI) substrates. The strain states of Ge clusters and Si islands were measured by grazing-incidence diffraction using a laboratory-based X-ray diffraction technique. A tensile strain of up to 0.5% was detected in the Si islands after direct Ge deposition. Using a thin (∼10 nm) SiGe buffer layer between Si and Ge the tensile strain increases to 1.8%. Transmission electron microscopy studies confirm the absence of a regular grid of misfit dislocations in such structures. This clear experimental evidence for the compliance of Si nano-islands on SOI substrates opens a new integration concept that is not only limited to Ge but also extendable to semiconductors like III–V and II–VI materials.

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Moug, R., A. Alfaro-Martinez, L. Peng, T. Garcia, V. Deligiannakis, A. Shen et M. Tamargo. « Selective etching of InGaAs/InP substrates from II-VI multilayer heterostructures ». physica status solidi (c) 9, n^o 8-9 (6 juillet 2012) : 1728–31. http://dx.doi.org/10.1002/pssc.201100716.

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Garcia, Thor Axtmann, Vasilios Deligiannakis, Candice Forrester, Ido Levy et Maria C. Tamargo. « Bi2 Se3 van der Waals Virtual Substrates for II-VI Heterostructures ». physica status solidi (b) 254, n^o 11 (28 août 2017) : 1700275. http://dx.doi.org/10.1002/pssb.201700275.

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Lopes, Nuno, Maria L. Maia, Cátia S. Pereira, Inês Mondragão-Rodrigues, Esmeralda Martins, Rosa Ribeiro, Ana Gaspar et al. « Leukocyte Imbalances in Mucopolysaccharidoses Patients ». Biomedicines 11, n^o 6 (13 juin 2023) : 1699. http://dx.doi.org/10.3390/biomedicines11061699.

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Mucopolysaccharidoses (MPSs) are rare inherited lysosomal storage diseases (LSDs) caused by deficient activity in one of the enzymes responsible for glycosaminoglycans lysosomal degradation. MPS II is caused by pathogenic mutations in the IDS gene, leading to deficient activity of the enzyme iduronate-2-sulfatase, which causes dermatan and heparan sulfate storage in the lysosomes. In MPS VI, there is dermatan sulfate lysosomal accumulation due to pathogenic mutations in the ARSB gene, leading to arylsulfatase B deficiency. Alterations in the immune system of MPS mouse models have already been described, but data concerning MPSs patients is still scarce. Herein, we study different leukocyte populations in MPS II and VI disease patients. MPS VI, but not MPS II patients, have a decrease percentage of natural killer (NK) cells and monocytes when compared with controls. No alterations were identified in the percentage of T, invariant NKT, and B cells in both groups of MPS disease patients. However, we discovered alterations in the naïve versus memory status of both helper and cytotoxic T cells in MPS VI disease patients compared to control group. Indeed, MPS VI disease patients have a higher frequency of naïve T cells and, consequently, lower memory T cell frequency than control subjects. Altogether, these results reveal MPS VI disease-specific alterations in some leukocyte populations, suggesting that the type of substrate accumulated and/or enzyme deficiency in the lysosome may have a particular effect on the normal cellular composition of the immune system.

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Nguyen, Quang-Minh, Duy-Cam Bui, Thao Phuong, Van-Huong Doan, Thi-Nham Nguyen, Minh-Viet Nguyen, Thien-Hien Tran et Quang-Trung Do. « Investigation of Heavy Metal Effects on the Anaerobic Co-Digestion Process of Waste Activated Sludge and Septic Tank Sludge ». International Journal of Chemical Engineering 2019 (1 décembre 2019) : 1–9. http://dx.doi.org/10.1155/2019/5138060.

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The effect of copper, zinc, chromium, and lead on the anaerobic co-digestion of waste activated sludge and septic tank sludge in Hanoi was studied in the fermentation tests by investigating the substrate degradation, biogas production, and process stability at the mesophilic fermentation. The tested heavy metals were in a range of concentrations between 19 and 80 ppm. After the anaerobic tests, the TS, VS, and COD removal efficiency was 4.12%, 9.01%, and 23.78% for the Cu(II) added sample. Similarly, the efficiencies of the Zn(II) sample were 1.71%, 13.87%, and 16.1% and Cr(VI) efficiencies were 15.28%, 6.6%, and 18.65%, while the TS, VS, and COD removal efficiency of the Pb(II) added sample was recorded at 16.1%, 17.66%, and 16.03% at the concentration of 80 ppm, respectively. Therefore, the biogas yield also decreased by 36.33%, 31.64%, 31.64%, and 30.60% for Cu(II), Zn(II), Cr(VI), and Pb(II) at the concentration of 80 ppm, compared to the raw sample, respectively. These results indicated that Cu(II) had more inhibiting effect on the anaerobic digestion of the sludge mixture than Zn(II), Cr(VI), and Pb(II). The relative toxicity of these heavy metals to the co-digestion process was as follows: Cu (the most toxic) > Zn > Cr > Pb (the least toxic). The anaerobic co-digestion process was inhibited at high heavy metal concentration, which resulted in decreased removal of organic substances and produced biogas.

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Che, Song-Bek, Ichirou Nomura, Akihiko Kikuchi et Katsumi Kishino. « Yellow-green ZnCdSe/BeZnTe II-VI laser diodes grown on InP substrates ». Applied Physics Letters 81, n^o 6 (5 août 2002) : 972–74. http://dx.doi.org/10.1063/1.1492311.

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Wissmann, H., T. Tran Anh, S. Rogaschewski et M. von Ortenberg. « Self-organized MBE growth of II–VI epilayers on patterned GaSb substrates ». Journal of Crystal Growth 201-202 (mai 1999) : 619–22. http://dx.doi.org/10.1016/s0022-0248(98)01423-7.

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Wang, S., D. Ding, X. Liu, X. B. Zhang, D. J. Smith, J. K. Furdyna et Y. H. Zhang. « MBE growth of II–VI materials on GaSb substrates for photovoltaic applications ». Journal of Crystal Growth 311, n^o 7 (mars 2009) : 2116–19. http://dx.doi.org/10.1016/j.jcrysgro.2008.09.189.

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Faschinger, W., et J. Nürnberger. « Green II–VI light emitting diodes with long lifetime on InP substrate ». Applied Physics Letters 77, n^o 2 (10 juillet 2000) : 187–89. http://dx.doi.org/10.1063/1.126919.

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Anderson, Thomas, Donovan L. Barrett, J. Chen, Ejiro Emorhokpor, A. Gupta, R. H. Hopkins, Andrew E. Souzis et al. « Growth of Large Diameter SiC Crystals by Advanced Physical Vapor Transport ». Materials Science Forum 483-485 (mai 2005) : 9–12. http://dx.doi.org/10.4028/www.scientific.net/msf.483-485.9.

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Semi-insulating 6H SiC substrates, 2”, 3” and 100mm in diameter, and n+ 4H SiC substrates, 2” and 3” in diameter, are grown at II-VI using the Advanced Physical Vapor Transport (APVT) technique [1]. The process utilizes high-purity SiC source and employs special measures aimed at the reduction of background contamination. Semi-insulating properties are achieved by precise vanadium compensation, which yields substrates with stable and uniform electrical resistivity reaching ~ 1011 Ω-cm and higher. Conductive n+ 4H SiC crystals with the spatially uniform resistivity of 0.02 W-cm are grown using nitrogen doping. Crystal quality of the substrates, their electrical properties and low temperature photoluminescence are discussed.

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Jung, M. N., S. Y. Ha, H. S. Kim, H. J. Ko, H. Ko, W. H. Lee, D. C. Oh, Y. Murakami, T. Yao et J. H. Chang. « The Shape Control of ZnO Based Nanostructures ». Journal of Nanoscience and Nanotechnology 6, n^o 11 (1 novembre 2006) : 3628–32. http://dx.doi.org/10.1166/jnn.2006.17996.

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Tetrapod-shape ZnO nanostructures are formed on Si substrates by vapor phase transportation method. The effects of two important growth parameters, growth temperature and VI/II ratio, are investigated. The growth temperature is varied in the range from 600 °C to 900 °C to control the vapor pressure of group II-element and the formation process of nanostructures. VI/II ratio was changed by adjusting the flux of carrier gas which affects indirectly the supplying rate of group VI-element. From the scanning electron microscopy (SEM), systematic variation of shape including cluster, rod, wire and tetrapod was observed. ZnO tetrapods, formed at 800 °C under the carrier gas flux of 0.5 cc/mm2 min, show considerably uniform shape with 100 nm thick and 1 ∼ 1.5 μm long legs. Also stoichiometric composition (O/Zn ∼ 1) was observed without any second phase structures. While, the decrease of growth temperature and the increase of carrier gas flux, results in the irregular shaped nanostructures with non-stoichiometric composition. The excellent luminescence properties, strong excitonic UV emission at 3.25 eV without deep level emission, indicate that the high crystalline quality tetrapod structures can be formed at the optimized growth conditions.

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Dufresne, E., et D. E. Brodie. « A study of high-purity CdxSe1−x vacuum-deposited thin films ». Canadian Journal of Physics 69, n^o 2 (1 février 1991) : 124–30. http://dx.doi.org/10.1139/p91-018.

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Pure CdSe films were vacuum deposited onto liquid-nitrogen-cooled substrates using a doubly baffled source in an attempt to prepare and study amorphous CdSe. The deposition of stable stoichiometric amorphous pure films was not verified since the films were always polycrystalline when analyzed at room temperature. CdSe appears to be different from some other II– VI compounds that can be prepared as pure stoichiometric amorphous materials and can be studied at a temperature up to 400 K. Pure nonstoichiometric films were also prepared using a second source to supply the excess component. Amorphous Se-rich films could only be produced for samples with at least 59 at.% Se. For Cd-rich films, the excess Cd agglomerates and the CdSe crystallite sizes are smaller than those observed in stoichiometric films. The electrical and optical properties scale as a function of the Cd content and the films become metallike as the Cd content increases through 60 at.%. The electrical transport properties are very different for polycrystalline films, depending on whether the CdSe is deposited on a hot substrate, or on a cold substrate and annealed to the same high temperature. We show that impure amorphous films of CdSe can be deposited if the system's background pressure is high.

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Sorokin, Sergey V., Pavel S. Avdienko, Irina V. Sedova, Demid A. Kirilenko, Valery Yu Davydov, Oleg S. Komkov, Dmitrii D. Firsov et Sergey V. Ivanov. « Molecular Beam Epitaxy of Layered Group III Metal Chalcogenides on GaAs(001) Substrates ». Materials 13, n^o 16 (5 août 2020) : 3447. http://dx.doi.org/10.3390/ma13163447.

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Development of molecular beam epitaxy (MBE) of two-dimensional (2D) layered materials is an inevitable step in realizing novel devices based on 2D materials and heterostructures. However, due to existence of numerous polytypes and occurrence of additional phases, the synthesis of 2D films remains a difficult task. This paper reports on MBE growth of GaSe, InSe, and GaTe layers and related heterostructures on GaAs(001) substrates by using a Se valve cracking cell and group III metal effusion cells. The sophisticated self-consistent analysis of X-ray diffraction, transmission electron microscopy, and Raman spectroscopy data was used to establish the correlation between growth conditions, formed polytypes and additional phases, surface morphology and crystalline structure of the III–VI 2D layers. The photoluminescence and Raman spectra of the grown films are discussed in detail to confirm or correct the structural findings. The requirement of a high growth temperature for the fabrication of optically active 2D layers was confirmed for all materials. However, this also facilitated the strong diffusion of group III metals in III–VI and III–VI/II–VI heterostructures. In particular, the strong In diffusion into the underlying ZnSe layers was observed in ZnSe/InSe/ZnSe quantum well structures, and the Ga diffusion into the top InSe layer grown at ~450 °C was confirmed by the Raman data in the InSe/GaSe heterostructures. The results on fabrication of the GaSe/GaTe quantum well structures are presented as well, although the choice of optimum growth temperatures to make them optically active is still a challenge.

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Samir Attia Nagadi, Samir Attia Nagadi. « In vitro Gas Production, Methane Emission and Rumen Fermentation Characteristics with Increasing Roughage to Concentrate Ratios ». journal of King Abdulaziz University - Meteorology, Environment and Arid Land Agriculture Sciences 28, n^o 2 (9 juin 2019) : 27–36. http://dx.doi.org/10.4197/met.28-2.3.

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Effects of roughage to concentrate ratio on gas production (GP) and nutrient degradability were evaluated in vitro. Rations I: 0R:100C, II: 20R:80C, III: 40R:60C, IV: 60R:40C, V: 80R:20C and VI: 100R:0C were incubated for 24h. Concentrate (0R:100C) produced greater GP/gDM, TDOM and MCP. TDDM was higher for rations I to IV than V and VI. Roughage (100R:0C) had lower PF and higher pH and protozoal count with no VFA effect. Ration III and IV containing 60 and 40% concentrate, respectively exhibited balanced distribution of soluble substrate between microbial biomass production and fermentation waste products and are optimal for sheep nutrition.

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Stoica, V. A., L. Endicott, H. H. Shen, W. Liu, K. Sun, C. Uher et R. Clarke. « High-quality II-VI films grown on amorphous substrates using tunable tetradymite templates ». Applied Physics Letters 105, n^o 22 (1 décembre 2014) : 221606. http://dx.doi.org/10.1063/1.4903268.

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Ashenford, D., D. Johnston, B. Lunn et C. G. Scott. « Characteristics of II-VI semiconductor thin films grown by MBE on InSb substrates ». Journal of Physics : Condensed Matter 1, SB (1 octobre 1989) : SB51—SB54. http://dx.doi.org/10.1088/0953-8984/1/sb/010.

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Sidorov, Yu G., M. V. Yakushev, D. N. Pridachin, V. S. Varavin et L. D. Burdina. « The heteroepitaxy of II–VI compounds on the non-isovalent substrates (ZnTe/Si) ». Thin Solid Films 367, n^o 1-2 (mai 2000) : 203–9. http://dx.doi.org/10.1016/s0040-6090(00)00674-x.

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Hughes, W. C., C. Boney, M. A. L. Johnson, J. W. Cook et J. F. Schetzina. « Surface preparation of ZnSe substrates for MBE growth of II–VI light emitters ». Journal of Crystal Growth 175-176 (mai 1997) : 546–51. http://dx.doi.org/10.1016/s0022-0248(96)01022-6.

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Eschenlauer, S. C. P., N. McKain, N. D. Walker, N. R. McEwan, C. J. Newbold et R. J. Wallace. « Ammonia Production by Ruminal Microorganisms and Enumeration, Isolation, and Characterization of Bacteria Capable of Growth on Peptides and Amino Acids from the Sheep Rumen ». Applied and Environmental Microbiology 68, n^o 10 (octobre 2002) : 4925–31. http://dx.doi.org/10.1128/aem.68.10.4925-4931.2002.

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ABSTRACT Excessive NH3 production in the rumen is a major nutritional inefficiency in ruminant animals. Experiments were undertaken to compare the rates of NH3 production from different substrates in ruminal fluid in vitro and to assess the role of asaccharolytic bacteria in NH3 production. Ruminal fluid was taken from four rumen-fistulated sheep receiving a mixed hay-concentrate diet. The calculated rate of NH3 production from Trypticase varied from 1.8 to 19.7 nmol mg of protein−1 min−1 depending on the substrate, its concentration, and the method used. Monensin (5 μM) inhibited NH3 production from proteins, peptides, and amino acids by an average of 28% with substrate at 2 mg/ml, compared to 48% with substrate at 20 mg/ml (P = 0.011). Of the total bacterial population, 1.4% grew on Trypticase alone, of which 93% was eliminated by 5 μM monensin. Many fewer bacteria (0.002% of the total) grew on amino acids alone. Nineteen isolates capable of growth on Trypticase were obtained from four sheep. 16S ribosomal DNA and traditional identification methods indicated the bacteria fell into six groups. All were sensitive to monensin, and all except one group (group III, similar to Atopobium minutum), produced NH3 at >250 nmol min−1 mg of protein−1, depending on the medium, as determined by a batch culture method. All isolates had exopeptidase activity, but only group III had an apparent dipeptidyl peptidase I activity. Groups I, II, and IV were most closely related to asaccharolytic ruminal and oral Clostridium and Eubacterium spp. Group V comprised one isolate, similar to Desulfomonas piger (formerly Desulfovibrio pigra). Group VI was 95% similar to Acidaminococcus fermentans. Growth of the Atopobium- and Desulfomonas-like isolates was enhanced by sugars, while growth of groups I, II, and V was significantly depressed by sugars. This study therefore demonstrates that different methodologies and different substrate concentrations provide an explanation for different apparent rates of ruminal NH3 production reported in different studies and identifies a diverse range of hyper-ammonia-producing bacteria in the rumen of sheep.

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Gessert, T. A., E. Colegrove, B. Stafford, R. Kodama, Wei Gao, H. R. Moutinho, D. Kuciauskas, R. C. Reedy, T. M. Barnes et S. Sivananthan. « II-VI Material Integration With Silicon for Detector and PV Applications ». MRS Advances 1, n^o 50 (2016) : 3391–402. http://dx.doi.org/10.1557/adv.2016.408.

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ABSTRACTHeteroepitaxial growth of high-quality II-VI-alloy materials on Si substrates is a well-established commercial growth process for infrared (IR) detector devices. However, it has only recently been recognized that these same processes may have important applications for production of high-efficiency photovoltaic devices. This submission reviews the process developments that have enabled effective heteroepitaxy of II-VI alloy materials on lattice-mismatched Si for IR detectors as a foundation to describe recent efforts to apply these insights to the fabrication of multijunction Si/CdZnTe devices with ultimate conversion efficiencies >40%. Reviewed photovoltaic studies include multijunction Si/CdZnTe devices with conversion efficiency of ∼17%, analysis of structural and optoelectrical quality of undoped CdTe epilayer films on Si, and the effect that a Te-rich growth environment has on the structural and optoelectronic quality of both undoped and As-doped heteroepitaxial CdTe.

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Silvia CR, Wilma Delphine, Akshay Atre, Preksha Shivakumar et Arpita Chakraborty. « Mucopolysaccharidosis : An overview and new treatment modalities ». International Journal of Clinical Biochemistry and Research 10, n^o 2 (15 juillet 2023) : 101–9. http://dx.doi.org/10.18231/j.ijcbr.2023.016.

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Mucopolysaccharidosis is a lysosomal storage disorder, caused due to deficiency of enzymes required for the breakdown of Mucopolysaccharides. These undegraded Mucopolysaccharides accumulate in various tissues and cause characteristic features like neurological deficit, impaired motor function, developmental delay, hearing loss, behavioral problems, corneal clouding, glaucoma, respiratory distress, coarse facial features, skeletal deformities, and organomegaly. Based on deficient enzymes they have divided into subtypes Mucopolysaccharidosis I (MPS I) Hunter syndrome (I H / I HS / I S), Mucopolysaccharidosis II(MPS II) Hunter syndrome (severe and mild form), Mucopolysaccharidosis III (MPS III) Sanfilippo syndrome, Mucopolysaccharidosis IV(MPS IV) Morquio syndrome, Mucopolysaccharidosis VI(MPS VI) Maroteaux Lamy syndrome, Mucopolysaccharidosis VI (MPS VII) Sly syndrome. Diagnosis is classically based on clinical examination and urine analysis. Enzyme assay can also aid in diagnosis. Chorionic villi sampling and amniocentesis are also becoming popular. The main objective of treatment is to improve the quality of life. Symptomatic management includes daily exercise, physiotherapy, tonsillectomy, shunting surgery, and corneal transplantation. There are various recent concepts utilized for the treatment of Mucopolysaccharidosis. This review article emphasizes such treatment aspects as Hematopoietic stem cell therapy, Enzyme replacement therapy, Gene therapy, Nano-enabled therapy, and Substrate reduction therapy.

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Wiater, Józefa. « Sequential Analysis of Phosphorus Compounds Contained in the Substrates and the Digestate ». Water 14, n^o 22 (13 novembre 2022) : 3655. http://dx.doi.org/10.3390/w14223655.

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The aim of this study was to determine the properties of the components used for fermentation and digestate. The content of phosphorus and its fraction in the substrate mixture undergoing fermentation in the real agricultural biogas plant and in the digestate was determined. The research was carried out based on substrate and digestate samples from an agricultural biogas plant with a production capacity of up to 1 MW (Mega Watt). The biogas plant operates in a continuous system. To ensure optimal operating conditions of the installation, it is necessary to provide substrates with appropriate quality and composition throughout the year. The substrate consists mainly of maize silage, poultry manure and potato pulp. In the study, samples of individual substrates and digestate were taken in four terms. The time of collection depended on the fraction of individual substrates in the charge composition. In the first term, the fraction of three substrates in the orchard was as follows: 79%—maize silage, 15%—poultry manure, and 6%—potato pulp. In the second term, it reached 82%, 10% and 8%, respectively, in the third 83%, 8% and 9%, and the fourth 80%, 6% and 14%. Eight samples of the substrates and digestate were collected every time. The samples were determined considering the content of dry matter, organic matter and the total content of phosphorus, magnesium, calcium, potassium, nitrogen, iron, and the pH value. After drying the samples, the fractions were determined by the phosphorus method with the Sequential Chang–Jackson extraction with subsequent modifications by Petersen and Corey. Measurements were made using the ICP-AES method. The following fractions were isolated: P-lab. (labile) labile phosphorus, P-Al phosphorus in aluminium phosphates, P-Fe phosphorus in gel phosphates, P-red.(reduced), P-ok. (occluded) the fraction of occluded phosphates absorbed on the surface of mineral particles, P-Ca phosphorus in calcium phosphates. It was found that the physicochemical composition of the feed and digestate was determined by the content of about 80% of maize silage in fermented substrates. The addition of substrates in the form of poultry manure and potato pulp influenced the content of total phosphorus and slightly modified the content of individual fractions in it. The fermentation process, to some extent, decreased the share of fraction I (mobile) and fraction II (combined with aluminium), increased the share of fraction VI (combination with calcium) and had no significant effect on the others. Digestate is a material rich in macronutrients and should be used as a fertilizer. The dosage of digestate used for fertilisation should be preceded by a knowledge of the soils and the requirements of the cultivated plants in order to prevent mobile phosphorus fractions from entering surface waters and increasing the eutrophication process.

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Gupta, Avinash K., Ping Wu, Varatharajan Rengarajan, Xue Ping Xu, Murugesu Yoganathan, Christ Martin, Ejiro Emorhokpor, Andy Souzis, Ilya Zwieback et Tom Anderson. « Status of Large Diameter SiC Single Crystals ». Materials Science Forum 717-720 (mai 2012) : 3–8. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.3.

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Large-diameter SiC single crystals are grown at II-VI by the sublimation technique. 100mm substrates of semi-insulating 6H SiC and n-type 4H SiC are produced as commercial products; in development, diameter expansion to 125mm has been achieved. Over the last two years, significant improvements have been made in crystal quality. The values of FWHM of x-ray rocking curves are typically 20-40 arc-seconds for 6H SI wafers and 12-30 arc-seconds for 4H n+ wafers. Micropipe density is less than 3 cm-2, and less than 0.1 cm-2 in best substrates. Electrical resistivity of SI substrates is, typically, of 1011 Ω•cm or above. For 4H n+ substrates, the typical dislocation density is about 9×103 cm-2 and the typical BPD density is less than 1×103 cm-2.

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HIGO, NORIYUKI, TAKAO OISHI, AKIKO YAMASHITA, KEIJI MATSUDA et MOTOHARU HAYASHI. « Expression of MARCKS mRNA in lateral geniculate nucleus and visual cortex of normal and monocularly deprived macaque monkeys ». Visual Neuroscience 19, n^o 5 (septembre 2002) : 633–43. http://dx.doi.org/10.1017/s0952523802195083.

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We performed a nonradioactive in situ hybridization histochemistry (ISH) study of the lateral geniculate nucleus (LGN) and the primary visual area (area 17) of the macaque monkey to investigate mRNA expression of the myristoylated alanine-rich C-kinase substrate (MARCKS), a major protein kinase C (PKC) substrate. In the LGN, intense hybridization signals were observed in both magnocellular neurons (layers 1 and 2) and parvocellular neurons (layers 3 to 6). Double labeling using ISH and immunofluorescence revealed that MARCKS mRNA was coexpressed with the α-subunit of type II calcium/calmodulin-dependent protein kinase, indicating that MARCKS mRNA is also expressed in koniocellular neurons in the LGN. GABA-immunoreactive neurons in the LGN did not contain MARCKS mRNA, indicating that MARCKS mRNA is not expressed in inhibitory interneurons. The signals were generally weak in area 17, and intense signals were restricted to large neurons in layers IVB, V, and VI. GABA-immunoreactive neurons in layers II–VI of area 17 did not contain MARCKS mRNA. Double-label ISH revealed that MARCKS mRNA was coexpressed with mRNA of GAP-43, another PKC substrate, in neurons of both the LGN and area 17. To determine whether the expression of MARCKS mRNA is regulated by retinal activity, we performed ISH in the LGN and area 17 of monkeys deprived of monocular visual input by tetrodotoxin. After monocular deprivation for 5 to 30 days, MARCKS mRNA was down-regulated in the LGN, but not in area 17. These results suggest that MARCKS mediates the activity-dependent changes in the excitatory relay neurons in the LGN.

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