Conductive Cotton by In Situ Laccase-Polymerization of Aniline

Conductive cotton fabrics were obtained via in situ aniline polymerization by laccase from Myceliophthora thermophila under mild reaction conditions without the addition of strong proton acids. The reactions were conducted using two types of reactors, namely a water bath (WB) and an ultrasonic bath (US), and the role of a mediator, 1-hydroxybenzotriazol (HBT), on the laccase-assisted polymerization of aniline was investigated. A similar polymerization degree was obtained when using both reactors—however, the ultrasonic bath allowed the experiments to be conducted in shorter periods of time (24 h for WB vs. 2 h for US). The data obtained also revealed that the mediator (1-hydroxybenzotriazol-HBT) played a crucial role in aniline oxidation. A higher conversion yield and polymerization degree were obtained when the reaction was conducted in the presence of this compound, as confirmed by MALDI-TOF analysis. The cotton fabrics coated with polyaniline presented deep coloration and conductivity, especially when the mediator was included on the reactional system. The results obtained are a step forward in the enzymatic polymerization of aniline with the purpose of obtaining coloured conductive textile surfaces, with potential applications in wearable electronics.

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Enzymatic synthesis and phosphorolysis of 4(2)-thioxo- and 6(5)-azapyrimidine nucleosides by E. coli nucleoside phosphorylases

Beilstein Journal of Organic Chemistry ◽

10.3762/bjoc.12.254 ◽

2016 ◽

Vol 12 ◽

pp. 2588-2601 ◽

Cited By ~ 3

Author(s):

Vladimir A Stepchenko ◽

Anatoly I Miroshnikov ◽

Frank Seela ◽

Igor A Mikhailopulo

Keyword(s):

Purine Nucleoside Phosphorylase ◽

Reaction Conditions ◽

E Coli ◽

No Formation ◽

Structural Peculiarities ◽

Substrate Properties ◽

Nucleoside Phosphorylases ◽

Derivatives Of

The trans-2-deoxyribosylation of 4-thiouracil (4SUra) and 2-thiouracil (2SUra), as well as 6-azauracil, 6-azathymine and 6-aza-2-thiothymine was studied using dG and E. coli purine nucleoside phosphorylase (PNP) for the in situ generation of 2-deoxy-α-D-ribofuranose-1-phosphate (dRib-1P) followed by its coupling with the bases catalyzed by either E. coli thymidine (TP) or uridine (UP) phosphorylases. 4SUra revealed satisfactory substrate activity for UP and, unexpectedly, complete inertness for TP; no formation of 2’-deoxy-2-thiouridine (2SUd) was observed under analogous reaction conditions in the presence of UP and TP. On the contrary, 2SU, 2SUd, 4STd and 2STd are good substrates for both UP and TP; moreover, 2SU, 4STd and 2’-deoxy-5-azacytidine (Decitabine) are substrates for PNP and the phosphorolysis of the latter is reversible. Condensation of 2SUra and 5-azacytosine with dRib-1P (Ba salt) catalyzed by the accordant UP and PNP in Tris∙HCl buffer gave 2SUd and 2’-deoxy-5-azacytidine in 27% and 15% yields, respectively. 6-Azauracil and 6-azathymine showed good substrate properties for both TP and UP, whereas only TP recognizes 2-thio-6-azathymine as a substrate. 5-Phenyl and 5-tert-butyl derivatives of 6-azauracil and its 2-thioxo derivative were tested as substrates for UP and TP, and only 5-phenyl- and 5-tert-butyl-6-azauracils displayed very low substrate activity. The role of structural peculiarities and electronic properties in the substrate recognition by E. coli nucleoside phosphorylases is discussed.

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Fischer-Tropsch synthesis nanostructured catalysts: understanding structural characteristics and catalytic reaction

Nanotechnology Reviews ◽

10.1515/ntrev-2013-0025 ◽

2013 ◽

Vol 2 (5) ◽

pp. 547-576 ◽

Cited By ~ 10

Author(s):

Peng Zhai ◽

Geng Sun ◽

Qingjun Zhu ◽

Ding Ma

Keyword(s):

Structural Characteristics ◽

Nanostructured Catalysts ◽

Catalytic Performance ◽

Tropsch Synthesis ◽

Fischer Tropsch ◽

Reaction Conditions ◽

Catalyst Structure ◽

Fischer Tropsch Synthesis

AbstractOne key goal of heterogeneous catalysis study is to understand the correlation between the catalyst structure and its corresponding catalytic activity. In this review, we focus on recent strategies to synthesize well-defined Fischer-Tropsch synthesis (FTS) nanostructured catalysts and their catalytic performance in FTS. The development of those promising catalysts highlights the potentials of nanostructured materials to unravel the complex and dynamic reaction mechanism, particularly under the in situ reaction conditions. The crucial factors associated with the catalyst compositions and structures and their effects on the FTS activities are discussed with an emphasis on the role of theoretical modeling and experimental results.

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The skyrmion annihilations induced by local reversal of background field in skyrmion lattice

Journal of Physics D Applied Physics ◽

10.1088/1361-6463/ac4a39 ◽

2022 ◽

Author(s):

Yang Li ◽

Hua Pang

Keyword(s):

Stable State ◽

Topological Defects ◽

Background Field ◽

Information Storage ◽

Uniform Field ◽

Annihilation Process ◽

Complex Process ◽

Potential Applications

Abstract The understanding of the creation and annihilation dynamics of a magnetic skyrmion is significant due to its potential applications in information storage and spintronics. Although there have been extensive investigations on the annihilation of isolated skyrmion, topological annihilation in periodic skyrmion lattice is a more complex process. We report a micromagnetic simulation study about the annihilation process of a two-dimensional skyrmion triangular lattice triggered by a uniform field HREV of comparable size to the skyrmion, which is opposite to the direction of the background field, revealing two annihilation modes. When the HREV center is within the range of a skyrmion, the neighboring skyrmions annihilate in situ, while the center is between adjacent skyrmions, anti-skyrmion is induced in the interstitial region. Both mechanisms tend to experience the intermediate topological vortex or antivortex structure, and the spin system undergoes a long period of relaxation to reach a stable state after the topological charge is stabilized. Our results present a local annihilation scheme that is easy to achieve in a 2D skyrmion lattice and highlight the role of interaction between skyrmions in the transformation between different kinds of topological defects.

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Growth of Boron Nanowires by Chemical Vapor Deposition

MRS Proceedings ◽

10.1557/proc-1017-dd03-04-ee02-04 ◽

2007 ◽

Vol 1017 ◽

Author(s):

Li Guo ◽

Raj N. Singh

Keyword(s):

Vapor Deposition ◽

Chemical Vapor ◽

Growth Mechanisms ◽

Nano Structures ◽

Gas Chemistry ◽

Potential Applications ◽

Vls Growth ◽

Boron Nanowires

AbstractMotivated by the extensive research on carbon nanotubes (CNTs), boron and its related nano-structures have attracted increasing interests for potential applications in nanodevices and nanotechnologies due to their extraordinary properties. B-related nanostructures are successfully grown on various substrates in a CVD process. The boron nanowires have diameters around 50-200 nanometers and lengths up to a few microns. The gas chemistry is monitored by the in-situ mass-spectroscopy, which helps to identify reactive species in the process. Modified vapor-solid growths as well as VLS growth mechanisms are proposed for the growth of these nanostructures. The role of the catalysts in the synthesis is also discussed.

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Iminopyridine Ni(II) Catalysts Affording Oily Hyperbranched Oligoethylenes and/or Crystalline Polyethylenes Depending on the Reaction Conditions: Possible Role of In Situ Catalyst Structure Modifications

10.20944/preprints202103.0600.v1 ◽

2021 ◽

Author(s):

Ilaria D'Auria ◽

Zeinab Saki ◽

Claudio Pellecchia

Keyword(s):

Ethylene Polymerization ◽

Active Species ◽

Polymerization Catalysts ◽

Reaction Conditions ◽

Catalyst Structure ◽

Variable Content ◽

Peculiar Behavior ◽

Number Of Branches

Nickel-based ethylene polymerization catalysts have unique features, being able to produce macromolecules with a variable content of branches, resulting in polymers ranging from semicrystalline plastics to elastomers to hyperbranched amorphous waxes and oils. In addition to Brookhart's α-diimine catalysts, iminopyridine Ni(II) complexes are among the most investigated systems. We report that Ni(II) complexes bearing aryliminopyridine ligands with bulky substituents both at the imino moiety and in the 6-position of pyridine afford either hyperbranched low molecular weight polyethylene oils or prevailingly linear crystalline polyethylenes or both depending on the ligand structure and the reaction conditions. The formation of multiple active species in situ is suggested by analysis of the post-polymerization catalyst residues, showing the partial reduction of the imino function. Some related arylaminopyridine Ni(II) complexes were also synthesized and tested, showing a peculiar behavior, i.e. the number of branches of the produced polyethylenes increases while ethylene pressure increases.

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Development and characterization of conductive textile (cotton) for wearable electronics and soft robotic applications

Textile Research Journal ◽

10.1177/0040517519897113 ◽

2020 ◽

Vol 90 (15-16) ◽

pp. 1792-1804

Author(s):

Zuhaib Hassan ◽

Fatma Kalaoglu ◽

Ozgur Atalay

Keyword(s):

Cotton Fabric ◽

Cotton Fabrics ◽

Metal Coating ◽

Wearable Electronics ◽

Before And After ◽

Coating Method ◽

Yarn Count ◽

Finer Yarn ◽

Conductive Textile ◽

Fabric Surface

This study aims to manufacture and characterize various types of conductive cotton fabrics through the copper metal coating approach. Thus, we selected nine-combed cotton knitted fabrics with different yarn fineness and elastane percentage in order to see the effect of these parameters on conductivity and physical properties of the samples. We also explored the surface morphology of all the knitted cotton fabric samples before and after the coating method via scanning electron microscopy (SEM), which showed a remarkably uniform deposition of copper on the fabric surface, and performed SEM-energy-dispersive X-ray spectroscopy to determine the coated material content on the surface of the fabric after the metal coating process. The results revealed that knitted cotton fabric of 5% elastane with the finer yarn count (Ne = 40/1) showed excellent conductivity compared to the other knitted cotton fabric of 10% elastane with a finer count (Ne = 40/1) or coarser 5% elastane (Ne = 30/1). Therefore, the knitted cotton fabrics of 5% elastane having the finer count (Ne = 40/1) can be considered a suitable candidate for e-textile applications.

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Inhibition of GSK-3 to induce cardiomyocyte proliferation: a recipe for in situ cardiac regeneration

Cardiovascular Research ◽

10.1093/cvr/cvy255 ◽

2018 ◽

Vol 115 (1) ◽

pp. 20-30 ◽

Cited By ~ 14

Author(s):

Anand Prakash Singh ◽

Prachi Umbarkar ◽

Yuanjun Guo ◽

Thomas Force ◽

Manisha Gupte ◽

...

Keyword(s):

Glycogen Synthase ◽

Cardiac Regeneration ◽

Cardiomyocyte Proliferation ◽

Short Supply ◽

Injured Myocardium ◽

Proliferation And Differentiation ◽

Potential Applications ◽

Specific Deletion

Abstract With an estimated 38 million current patients, heart failure (HF) is a leading cause of morbidity and mortality worldwide. Although the aetiology differs, HF is largely a disease of cardiomyocyte (CM) death or dysfunction. Due to the famously limited amount of regenerative capacity of the myocardium, the only viable option for advanced HF patients is cardiac transplantation; however, donor’s hearts are in very short supply. Thus, novel regenerative strategies are urgently needed to reconstitute the injured hearts. Emerging data from our lab and others have elucidated that CM-specific deletion of glycogen synthase kinase (GSK)-3 family of kinases induces CM proliferation, and the degree of proliferation is amplified in the setting of cardiac stress. If this proliferation is sufficiently robust, one could induce meaningful regeneration without the need for delivering exogenous cells to the injured myocardium (i.e. cardiac regeneration in situ). Herein, we will discuss the emerging role of the GSK-3s in CM proliferation and differentiation, including their potential implications in cardiac regeneration. The underlying molecular interactions and cross-talk among signalling pathways will be discussed. We will also review the specificity and limitations of the available small molecule inhibitors targeting GSK-3 and their potential applications to stimulate the endogenous cardiac regenerative responses to repair the injured heart.

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A Review of Enzyme Induced Carbonate Precipitation (EICP): The Role of Enzyme Kinetics

Sustainable Chemistry ◽

10.3390/suschem2010007 ◽

2021 ◽

Vol 2 (1) ◽

pp. 92-114

Author(s):

Isaac Ahenkorah ◽

Md Mizanur Rahman ◽

Md Rajibul Karim ◽

Simon Beecham ◽

Christopher Saint

Keyword(s):

Oil Recovery ◽

Ground Improvement ◽

Kinetic Properties ◽

Carbonate Precipitation ◽

Theoretical Understanding ◽

Sustainable Engineering ◽

Urease Enzyme ◽

Potential Applications

Enzyme-induced carbonate precipitation (EICP) is a relatively new bio-cementation technique for ground improvement. In EICP, calcium carbonate (CaCO3) precipitation occurs via urea hydrolysis catalysed by the urease enzyme sourced from plants. EICP offers significant potential for innovative and sustainable engineering applications, including strengthening of soils, remediation of contaminants, enhancement of oil recovery through bio-plugging and other in situ field applications. Given the numerous potential applications of EICP, theoretical understanding of the rate and quantity of CaCO3 precipitation via the ureolytic chemical reaction is vital for optimising the process. For instance, in a typical EICP process, the rate and quantity of CaCO3 precipitation can depend significantly on the concentration, activity and kinetic properties of the enzyme used along with the reaction environment such as pH and temperature. This paper reviews the research and development of enzyme-catalysed reactions and its applications for enhancing CaCO3 precipitation in EICP. The paper also presents the assessment and estimation of kinetic parameters, such as the maximal reaction velocity (Vmax) and the Michaelis constant (Km), that are associated with applications in civil and geotechnical engineering. Various models for evaluating the kinetic reactions in EICP are presented and discussed, taking into account the influence of pH, temperature and inhibitors. It is shown that a good understanding of the kinetic properties of the urease enzyme can be useful in the development, optimisation and prediction of the rate of CaCO3 precipitation in EICP.

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Iminopyridine Ni(II) Catalysts Affording Oily Hyperbranched Ethylene Oligomers and/or Crystalline Polyethylenes Depending on the Reaction Conditions: Possible Role of In Situ Catalyst Structure Modifications

Macromol ◽

10.3390/macromol1020010 ◽

2021 ◽

Vol 1 (2) ◽

pp. 121-129

Author(s):

Ilaria D’Auria ◽

Zeinab Saki ◽

Claudio Pellecchia

Keyword(s):

Active Species ◽

Polymerization Catalysts ◽

Reaction Conditions ◽

Catalyst Structure ◽

Variable Content ◽

Peculiar Behavior ◽

Number Of Branches ◽

Ethylene Oligomers

Nickel-based ethylene polymerization catalysts have unique features, being able to produce macromolecules with a variable content of branches, resulting in polymers ranging from semicrystalline plastics to elastomers to hyperbranched amorphous waxes and oils. In addition to Brookhart’s α-diimine catalysts, iminopyridine Ni(II) complexes are among the most investigated systems. We report that Ni(II) complexes bearing aryliminopyridine ligands with bulky substituents both at the imino moiety and in the 6-position of pyridine afford either hyperbranched low molecular weight polyethylene oils or prevailingly linear crystalline polyethylenes or both, depending on the ligand structure and the reaction conditions. The formation of multiple active species in situ is suggested by analysis of the post-polymerization catalyst residues, showing the partial reduction of the imino function. Some related arylaminopyridine Ni(II) complexes were also synthesized and tested, showing a peculiar behavior, i.e., the number of branches of the produced polyethylenes increases while ethylene pressure increases.

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An in situ and ex situ TEM study of the formation of thin cobalt silicide films by molecular beam epitaxy on the silicon (100) surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010010648x ◽

1988 ◽

Vol 46 ◽

pp. 884-885

Author(s):

D. Loretto ◽

J. M. Gibson ◽

S. M. Yalisove ◽

R. T. Tung

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Defect Density ◽

High Vacuum ◽

Ultra High Vacuum ◽

Ex Situ ◽

Metal Base ◽

In Situ Experiments ◽

Potential Applications

The cobalt disilicide/silicon system has potential applications as a metal-base and as a permeable-base transistor. Although thin, low defect density, films of CoSi2 on Si(111) have been successfully grown, there are reasons to believe that Si(100)/CoSi2 may be better suited to the transmission of electrons at the silicon/silicide interface than Si(111)/CoSi2. A TEM study of the formation of CoSi2 on Si(100) is therefore being conducted. We have previously reported TEM observations on Si(111)/CoSi2 grown both in situ, in an ultra high vacuum (UHV) TEM and ex situ, in a conventional Molecular Beam Epitaxy system.The procedures used for the MBE growth have been described elsewhere. In situ experiments were performed in a JEOL 200CX electron microscope, extensively modified to give a vacuum of better than 10-9 T in the specimen region and the capacity to do in situ sample heating and deposition. Cobalt was deposited onto clean Si(100) samples by thermal evaporation from cobalt-coated Ta filaments.

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