Utilization of Grape Seed Flour for Antimicrobial Lipopeptide Production by Bacillus amyloliquefaciens C5 Strain

Applied Biochemistry and Biotechnology - An endophytic Bacillus amyloliquefaciens strain called C5, able to produce biosurfactant lipopeptides with a broad antibacterial activity spectrum, has been...     

Coordination Cage-Based Emulsifiers: Templated Formation of Metal Oxide Microcapsules Monitored by In Situ LC-TEM

Metallo-supramolecular self-assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chemical reactions. However, the potential of low-molecular bottom-up self-assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo-supramolecular surfactant with the ability to stabilize non-aqueous emulsions for a significant period. The molecular design of the surfactant is based on a heteroleptic coordination cage ( CGA-3 ; CGA =Cage-based Gemini Amphiphile), assembled from two pairs of organic building blocks, grouped around two Pd(II) cations. Shape-complementarity between the differently functionalized components generates discrete amphiphiles with a tailor-made polarity profile, able to stabilize non-aqueous emulsions, such as hexadecane-in-DMSO. These emulsions were used as a medium for the synthesis of spherical metal oxide microcapsules (titanium oxide, zirconium oxide, and niobium oxide) from soluble, water-sensitive alkoxide precursors by allowing a controlled dosage of water to the liquid-liquid phase boundary. Synthesized materials were analyzed by a combination of electron microscopic techniques. In situ liquid cell transmission electron microscopy (LC-TEM) was utilized for the first time to visualize the dynamics of the emulsion-templated formation of hollow inorganic titanium oxide and zirconium oxide microspheres.     

Developing Luminescent Ratiometric Thermometers Based on a Covalent Organic Framework (COF)

Covalent Organic Frameworks (COFs), an emerging class of crystalline porous materials, are proposed as a new type of support for grafting lanthanide ions (Ln³⁺) and employing these hybrid materials as ratiometric luminescent thermometers. A TpBpy‐COF—prepared from 1,3,5‐triformylphloroglucinol (Tp) and 2,2′‐bipyridine‐5,5′‐diamine (Bpy) grafted with Eu/Tb and Dy acetylacetone (acac) complexes can be successfully used as a luminescent thermometer in the 10–360 K (Eu) and 280–440 K (Tb) ranges with good sensing properties (thermal sensitivity up to 1.403 % K^?1, temperature uncertainty δT<1 K above 110 K). For the Eu/Tb systems, we observe an unusual and rarely reported behavior, that is, no thermal quenching of the Tb³⁺ emission, a result of the absence of ion‐to‐ligand/host energy back‐transfer. The LnCOF materials proposed here could be a new class of materials employed for temperature‐sensing applications following up on the well‐known luminescent metal–organic framework thermometers.     

Intercomparison exercise on difficult to measure radionuclides in activated steel: statistical analysis of radioanalytical results and activation calculations

Journal of Radioanalytical and Nuclear Chemistry - This paper reports the results obtained during an intercomparison exercise for the determination of difficult to measure radionuclides in...     

Copper(I)-catalyzed azide-alkyne cycloaddition-assisted polymerization of linear glucose-derived co/polymers

The synthesis of linear and controllable oligomers and polymers using sugar-derived monomers is still highly challenging. Herein, we present a method allowing the linear polymerization of a bifunctional glucose derivative as monomer, which contained an azide group at C1 and a propargyl group at C4 position of the glucose ring. The reaction conditions were optimized by grafting the monomer onto the surface of silica nanoparticles (SiNPs) and at the end-modified polyethylene glycol (PEG). For grafting the surface of SiNPs with the monomer, an azide-bearing chlorosilane linker was synthesized and introduced onto SiNPs surface. The copper(I)-catalyzed azide-alkyne cycloaddition using the glucose-derived monomer led to the growth of linear triazole-linked oligosaccharide-mimics on the surface of SiNPs with a degree of polymerization up to 13 and the formation of cyclic trimers and tetramers in the solution. Furthermore, during polymerization of the monomer at end-modified PEG, various linear diblock-copolymers pseudo-cellulose-block-PEG and triblock-copolymers pseudo-cellulose-block-PEG-block-pseudo-cellulose were obtained. The polymerization reactions expired with nearly complete consumption of the monomer and high yields between 88 and 94% were achieved. Obtained block-copolymers showed amphiphilic properties that helped to fractionate obtained polymers into lower and higher molecular weight fractions with narrow polymer dispersity Đ.     

Nanorubbing of polythiophene surfaces

This work describes a new orientation method for semicrystalline poly(3-hexylthiophene) (P3HT) thin films, coupling nanorubbing and subsequent crystallization. Using the stylus of an atomic force microscope, we align the polymer chains on P3HT surfaces with a spatial and geometrical control of the oriented domains (nanorubbing). These chain-aligned structures can be made permanent thanks to the crystallization process, which propagates the orientation obtained at the surface to the bulk.     

Two new irregular acyclic sesquiterpenes aldehydes from Santolina corsica essential oil

Two isomeric irregular sesquiterpene aldehydes, namely 3,9-dimethyl-6-isopropyl-2(E),7(E),9-decatrienal and 3,9-dimethyl-6-isopropyl-2(Z),7(E),9-decatrienal, were isolated from the essential oil of Santolina corsica and their structures were elucidated by 1D and 2D NMR spectroscopy.     

Hamiltonian Stationary Tori in the Complex Projective Plane

Hamiltonian stationary Lagrangian surfaces are Lagrangian surfacesin a four-dimensional Kähler manifold which are criticalpoints of the area functional for Hamiltonian infinitesimaldeformations. In this paper we analyze these surfaces in thecomplex projective plane: in a previous work we showed thatthey correspond locally to solutions to an integrable system,formulated as a zero curvature on a (twisted) loop group. Herewe give an alternative formulation, using non-twisted loop groupsand, as an application, we show in detail why Hamiltonian stationaryLagrangian tori are finite type solutions, and eventually describethe simplest of them: the homogeneous ones. 2000 MathematicsSubject Classification 53C55 (primary), 53C42, 53C25, 58E12(secondary).