Nanocomposite TiO2-f-MWCNTs as durable support for Pt in polymer electrolyte fuel cells

Journal of Solid State Electrochemistry - Durability is a major issue and has been the growing focus of research for the successful commercialization of polymer electrolyte fuel cells (PEFCs)....     

Controlling the contents of microdroplets by exploiting the permeability of PDMS

A microfluidic device capable of exploiting the permeability of small molecules through polydimethylsiloxane (PDMS) has been fabricated in order to control the contents of microdroplets stored in storage wells. We demonstrate that protein precipitation and crystallization can be triggered by delivery of ethanol from a reservoir channel, thus controlling the protein solubility in microdroplets. Likewise quorum sensing in bacteria was triggered by delivery of the auto-inducer N-(3-oxododecanoyl)-l-homoserine lactone (OdDHL) through the PDMS membrane of the device.     

A tandem Baylis-Hillman-singlet oxygen oxidation reaction for facile synthesis of γ-substituted γ-hydroxybutenolides

A series of highly functionalised γ-hydroxyacryl γ-hydroxybutenolides, 2, were synthesised in 25-50% overall yields in two or three steps from 2-furfural using a tandem Baylis-Hillman-singlet oxygen oxidation reaction.     

Amine Exchange Reactions in Ionic Liquid

An operationally simple, inexpensive, efficient, and environmentally friendly protocol for the amine exchange reactions of 3-N,N-dimethylaminopropiophenone and N,N-dimethylaminomethylferrocene with primary aryl amines is developed using the ionic liquid [bmim]PF ₆ as a solvent. The recovered ionic liquid can be reused for several cycles with constant activity.     

Glucose Responsive Hydrogel Networks Based on Protein Recognition

Stimuli‐responsive materials capable of manifesting physical changes in response to environmental signals are valuable tools for use in a variety of biomedical applications. Herein we describe one such smart glucose‐responsive hydrogel material prepared by immobilizing the glucose/galactose binding protein within an acrylamide hydrogel network. This hydrogel demonstrates a quantitative “accordion”‐like dynamic response in the presence of glucose. We further show the feasibility of employing this responsive smart material as a gating agent for controlled drug delivery, thus, demonstrating that these hydrogels may eventually lead to the development of implantable drug delivery systems for diabetes management applications.

     

Anion exchange membrane from polyvinyl alcohol functionalized with quaternary ammonium groups via alkyl spacers

Anion exchange membranes (AEMs) functionalized with quaternary ammonium groups are prepared from polyvinyl alcohol for alkaline polymer electrolyte fuel cell (APEFC) application. A series of AEMs were synthesized by direct quaternization of PVA using flexible alkyl spacer as charge carrier added in different weight percentages. These membranes were further cross-linked chemically and thermally before evaluating their ionic conductivity and ion exchange capacity. The interaction of alkyl spacer group with the polymer backbone was confirmed by FT-IR spectroscopy. XRD pattern reveals that the introduction of quaternary ammonium group disrupts the crystalline structure of polymer, increasing its amorphous phase thereby enhancing the conductivity. The QPVA membrane with 15 wt% of alkyl spacer exhibited an improved conductivity of 0.0057 S cm^?1 at 40 °C in comparison with other ratios. The cell polarization data for the optimized QPVA membrane was studied at 40 °C with varying ionomer amount. The alkaline stability and cell durability for the optimized QPVA membrane were evaluated for 300 and 25 h, respectively.     

Fluoride-assisted regioselective conversion of functionalized furans to alpha-substituted gamma-hydroxybutenolides using singlet oxygen

A facile synthesis of alpha-substituted gamma-hydroxybutenolides from 3-furfural was achieved using a Baylis-Hillman reaction followed by singlet oxygen oxidation. The regioselectivity of this conversion was controlled by using TBAF.     

Repurposing n-butyl stannoic acid as highly efficient catalyst for direct amidation of carboxylic acids with amines

This is the first-time report on the repurposing n-butyl stannoic acid as a catalyst for direct amidation of carboxylic acids with amines. Notably, efficient amidation observed in comparison with all other catalytic methods reported up until now. The protocol has successfully applied to the synthesis of a variety of amides. Moderate reaction parameters, clean amidation with excellent yields of desired amides, ability to tolerate a variety of functional groups, easy product isolation; commercial availability and recyclability of the catalyst are key advantages of the current protocol.     

Indole-3-Acetic Acid Biosynthesis in Fusarium delphinoides Strain GPK, a Causal Agent of Wilt in Chickpea

Fusarium delphinoides (Ascomycota; Nectriaceae) is an indole-3-acetic acid (IAA) producing plant pathogen and a causal agent of wilt in chickpea. The IAA biosynthetic pathway in F. delphinoides strain GPK (FDG) was examined by analyzing metabolic intermediates and by feeding experiments. Gas chromatograph (GC) analysis of FDG culture filtrates showed the presence of metabolic intermediates of indole-3-pyruvic acid (IPyA), indole-3-acetamide (IAM), and tryptamine (TRA) pathways. The different IAA biosynthetic pathways were further confirmed by identifying the presence of different enzymes of these pathways. Substrate specificity study of aromatic amino acid aminotransferase revealed that the enzyme is highly specific for tryptophan (Trp) and α-ketoglutarate (α-kg) as amino group donor and acceptor, respectively. Furthermore, the concentration-dependent effect of exogenous IAA on fungal growth was established. Low concentration of exogenous IAA increases the fungal growth and at high concentration it decreases the growth of FDG.