Optically Active Methacrylic Polymers Bearing in the Side Chain the (S)-3-Hydroxypyrrolidinyl Group Linked to trans-bisazoaromatic Chromophore: Synthesis and Characterization

The synthesis by radical homopolymerization of a novel optically active methacrylic polymer containing a side-chain chiral moiety linked to a photochromic bisazoaromatic chromophore has been carried out starting from the related monomer (S)-3-methacryloyloxy-1-[4′-phenylazo-(4-azobenzene)]-pyrrolidine [(S)- MPAAP ]. The polymeric derivate has been fully characterized and its spectroscopic properties compared to those of the monomer and of the corresponding homopolymer bearing only one azoaromatic chromophore in the side chain. The optical activity displayed by the bisazo polymer is discussed in terms of extent of chiral conformation assumed by the macromolecules as a consequence of dipole-dipole interactions between the bisazoaromatic chromophores.     

On the existence of ɛ-fixed points

In this paper we prove some approximate fixed point theorems which extend, in a broad sense, analogous results obtained by Brânzei, Morgan, Scalzo and Tijs in 2003. By assuming also the weak demiclosedness property we state two fixed point theorems. Moreover, we study the existence of ?-Nash equilibria.     

Bifurcation phenomena for nonlinear superdiffusive Neumann equations of logistic type

We consider a nonlinear Neumann logistic equation driven by the p-Laplacian with a general Carathéodory superdiffusive reaction. We are looking for positive solutions of such problems. Using minimax methods from critical point theory together with suitable truncation techniques, we show that the equation exhibits a bifurcation phenomenon with respect to the parameter λ > 0. Namely, we show that there is a λ_* > 0 such that for λ < λ_*, the problem has no positive solution; for λ = λ_*, it has at least one positive solution; and for λ > λ_*, it has at least two positive solutions.     

Capillary electrophoresis separation of human milk neutral and acidic oligosaccharides derivatized with 2‐aminoacridone

Human milk is a unique fluid in glycobiology due to the presence of many free structurally complex oligosaccharides emerging as important dietary factors during early life and having many biological and protective functions. Methods that allow accurate profiling of oligosaccharide mixtures in this complex biological fluid with quantification of the four known genetically determined groups are welcomed. A high‐voltage CE separation and detection at 254 nm of 17 neutral and acidic human milk oligosaccharide (HMO) standard along with lactose derivatized with 2‐aminoacridone, using a BGE containing 20% methanol as an organic modifier and borate, able to form on‐capillary anionic borate‐polyol complexes, is reported. This CE approach was able to separate both neutral HMOs and acidic HMOs, with the sialic acid residue, also in the presence of lactose in high content. This method was applied to the four secretory groups individually extracted by a rapid and simple preparative step. LODs were found ranging from ～50 to 700 fmol. We were able to measure HMO content also in the presence of excess fluorophore, or interference from proteins, peptides, salts, and other impurities normally present in this complex biological fluid. Overall, CE equipped with a UV detector is a common analytical approach and this simple CE separation offers high resolution and sensitivity for the differentiation of human milk samples related to genetic groups and days of lactation by considering that important changes in HMO content are a reflection of the lactation day.     

Development of a Biosensor for Copper Detection in Aqueous Solutions Using an Anemonia sulcata Recombinant GFP

Fluorescent proteins from marine organisms represent potential candidates for biosensor development. In this paper, we described the isolation of a native green fluorescent protein from Anemonia sulcata and the cloning and purification of its equivalent as a recombinant protein in Escherichia coli. Furthermore, the spectroscopic behaviours of the native and recombinant GFPs were investigated as a function of Cu²⁺, Cd²⁺, Pb²⁺ and Ni²⁺ concentration. Our results suggest the high selectivity of both proteins at copper than the other metals and, for the recombinant protein, a great sensitivity at a very low concentration (0.1–1 μM). Moreover, starting from these data, using the combination of molecular biology techniques and optical setup, we developed a device for the detection of Cu²⁺ in water solutions. The quenching effect detected with the device showed that the relative attenuation of the signal (0.46?±?0.02 AU) was slightly larger than the data measured by fluorescence spectra (0.65?±?0.03 AU). The good sensitivity in the span of two orders of the magnitude of Cu²⁺ concentration, the fact that the instrument is made up of low-cost and sturdy parts and the selective quenching of rAsGFP to copper ions make this setup suited as a low cost, on-the-field, copper ion-specific biosensor.     

MK801 attenuates secondary injury in a mouse experimental compression model of spinal cord trauma

Background  

Glutamergic excitotoxicity has been shown to play a deleterious role in the pathophysiology of spinal cord injury (SCI). The aim of this study was to investigate the neuroprotective effect of dizocilpine maleate, MK801 (2 mg/Kg, 30 min and 6 hours after injury) in a mice model of SCI. The spinal cord trauma was induced by the application of vascular clips to the dura via a four-level T5-T8 laminectomy.     

Efficient visible-light photocatalytic water splitting by minute amounts of gold supported on nanoparticulate CeO2 obtained by a biopolymer templating method

When irradiated with visible light (λ > 400 nm) 1 wt % gold-supported ceria nanoparticles generate oxygen from water (10.5 μmol·h(-1)) more efficiently than the standard WO(3) (1.7 μmol·h(-1)) even under UV irradiation (9.5 μmol·h(-1)). This remarkable photocatalytic activity arises from a novel preparation method to reduce the particle size of ceria (5 nm) by means of electrostatic binding of Ce(4+) to alginate gel, subsequent supercritical CO(2) drying, and calcination. The low loading of Au is crucial for the observed high catalytic activity.     

Synthesis and Biological Evaluation of Halogenated E-Stilbenols as Promising Antiaging Agents

The increased risk of illness and disability is related to the age inevitable biological changes. Oxidative stress is a proposed mechanism for many age-related diseases. The crucial importance of polyphenol pharmacophore for aging process is largely described thanks to its effects on concentrations of reactive oxygen species. Resveratrol (3,5,4′-trihydroxy-trans-stilbene, RSV) plays a critical role in slowing the aging process but has a poor bioavailabity after oral intake. In this present work, a series of RSV derivatives was designed, synthesized, and evaluated as potential antioxidant agents. These derivatives contain substituents with different electronic and steric properties in different positions of aromatic rings. This kind of substituents affects the activity and the bioavailability of these compounds compared with RSV used as reference compound. Studies of Log P values demonstrated that the introduction of halogens gives the optimum lipophilicity to be considered promising active agents. Among them, compound 6 showed the higher antioxidant activity than RSV. The presence of trifluoromethyl group together with a chlorine atom increased the antioxidant activity compared to RSV.