68 research outputs found

    Kinetic and mechanistic aspects of acid-catalysed hydrolysis of hydroxamic acids

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    1089-110

    Episodic Ataxia Type 1 (K‐channelopathy) Manifesting as Paroxysmal Nonkinesogenic Dyskinesia: Expanding the Phenotype

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/138880/1/mdc312518_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/138880/2/mdc312518.pd

    Sustainable Phenylalanine-Derived SAILs for Solubilization of Polycyclic Aromatic Hydrocarbons

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    The solubilization capacity of a series of sustainable phenylalanine-derived surface-active ionic liquids (SAILs) was evaluated towards polycyclic aromatic hydrocarbons—naphthalene, anthracene and pyrene. The key physico-chemical parameters of the studied systems (critical micelle concentration, spectral properties, solubilization parameters) were determined, analyzed and compared with conventional cationic surfactant, CTABr. For all studied PAH solubilization capacity increases with extension of alkyl chain length of PyPheOCn SAILs reaching the values comparable to CTABr for SAILs with n = 10–12. A remarkable advantage of the phenylalanine-derived SAILs PyPheOCn and PyPheNHCn is a possibility to cleave enzymatically ester and/or amide bonds under mild conditions, to separate polycyclic aromatic hydrocarbons in situ. A series of immobilized enzymes was tested to determine the most suitable candidates for tunable decomposition of SAILs. The decomposition pathway could be adjusted depending on the choice of the enzyme system, reaction conditions, and selection of SAILs type. The evaluated systems can provide selective cleavage of the ester and amide bond and help to choose the optimal decomposition method of SAILs for enzymatic recycling of SAILs transformation products or as a pretreatment towards biological mineralization. The concept of a possible practical application of studied systems for PAHs solubilization/separation was also discussed focusing on sustainability and a green chemistry approach

    Interfacial and thermodynamic approach of surfactants with α-chymotrypsin and trypsin: A comparative study

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    1128-1135This work deals with the interactions among cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) with α-chymotrypsin (α-CT) and trypsin in aqueous medium on pH 7.75 by conductivity and surface tension measurements. The critical micelle concentrations (CMC), surface parameters i.e., the maximum surface excess concentration (Γmax), minimum area per surfactant molecule (Amin), the surface pressure at CMC (πCMC) and thermodynamic parameters i.e., degree of ionization (α), Gibbs free energy of micellization (ΔG°m), the standard Gibbs energy of adsorption (ΔG°ads), the free energy at air-water interface (ΔGsmim) have been evaluated. The CMC has increased and surface tension of CMC (γCMC) values have decreased (at maximum μL of α-CT and trypsin), significantly in the presence of different μL of the added α-CT and trypsin. In this study, ΔG0ads value is established to be greater than ΔG0m, showing that adsorption is more favored in aqueous surfactants systems. Thermodynamic parameters show that enzyme-CTAB/SDS monomeric aggregation started to form micelles at a higher concentration of surfactant to compare with the CMC of pure CTAB/SDS micelles. It is significant that increasing the μL of α-CT and trypsin results in an increase in the spontaneity CMC on surfactants, α-CT and trypsin have more affinity for SDS compared to CTAB

    Electrochemical integration of graphene with light absorbing copper-based thin films

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    We present an electrochemical route for the integration of graphene with light sensitive copper-based alloys used in optoelectronic applications. Graphene grown using chemical vapor deposition (CVD) transferred to glass is found to be a robust substrate on which photoconductive Cu_{x}S films of 1-2 um thickness can be deposited. The effect of growth parameters on the morphology and photoconductivity of Cu_{x}S films is presented. Current-voltage characterization and photoconductivity decay experiments are performed with graphene as one contact and silver epoxy as the other

    Antiviral and Neuroprotective Role of Octaguanidinium Dendrimer-Conjugated Morpholino Oligomers in Japanese Encephalitis

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    Japanese encephalitis (JE) is caused by a flavivirus that is transmitted to humans by mosquitoes belonging to the Culex sp. The threat of JE looms over a vast geographical realm, encompassing approximately 10 billion people. The disease is feared because currently there are no specific antiviral drugs available. There have been reports where other investigators have shown that agents that block viral replication can be used as effective therapeutic countermeasures. Vivo-Morpholinos (MOs) are synthetically produced analogs of DNA or RNA that can be modified to bind with specific targeted regions in a genome. In this study the authors propose that in an animal model of JE, MOs specifically designed to bind with specific region of JE virus (JEV) genome, blocks virus production in cells of living organisms. This results in reduced mortality of infected animals. As the major target of JEV is the nerve cells, analysis of brain of experimental animals, post treatment with MOs, showed neuroprotection. Studies in cultured cells were also supportive of the antiviral role of the MOs. The potent anti-sense effect in animals and lack of obvious toxicity at the effective dosage make these MOs good research reagents with future therapeutic applications in JE

    RIG-I Mediates Innate Immune Response in Mouse Neurons Following Japanese Encephalitis Virus Infection

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    Neuroinflammation associated with Japanese encephalitis (JE) is mainly due to the activation of glial cells with subsequent release of proinflammatory mediators from them. The recognition of viral RNA, in part, by the pattern recognition receptor retinoic acid-inducible gene I (RIG-I) has been indicated to have a role in such processes. Even though neurons are also known to express this receptor, its role after JE virus (JEV) infections is yet to be elucidated.Upon infecting murine neuroblastoma cells and primary cortical neurons with JEV the expression profile of key proinflammatory cyto/chemokines were analyzed by qRT-PCR and bead array, both before and after ablation of RIG-I. Immunoblotting was performed to evaluate the levels of key molecules downstream to RIG-I leading to production of proinflammatory mediators. Changes in the intracellular viral antigen expression were confirmed by intracellular staining and immunoblotting. JEV infection induced neuronal expression of IL-6, IL-12p70, MCP-1, IP-10 and TNF-α in a time-dependent manner, which showed significant reduction upon RIG-I ablation. Molecules downstream to RIG-I showed significant changes upon JEV-infection, that were modulated following RIG-I ablation. Ablation of RIG-I in neurons also increased their susceptibility to JEV.In this study we propose that neurons are one of the potential sources of proinflammatory cyto/chemokines in JEV-infected brain that are produced via RIG-I dependent pathways. Ablation of RIG-I in neurons leads to increased viral load and reduced release of the cyto/chemokines
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