Non‐Adhesive Behavior of New Nanostructured PNIPAM Surfaces Towards Specific Neurodegenerative Proteins: Application to Storage and Titration of Tau Proteins

New nonfouling tubes are developed and their influence on the adhesion of neuroproteins is studied. The biomarkers are considered as single components (recombinant prion and Tau proteins) or in a solution of native and pathological forms. The samples are stored for 24 h at 4 °C in virgin and treated tubes layered with two different nanostructured coatings based on poly(N‐isopropylacrylamide) with either a positive or a neutral charge, and the protein adhesion is monitored. The recombinant protein with a high pI is repelled from the nanostructured surface that has a negative ζ potential, whereas the recombinant protein with the lower pI is attracted. Furthermore, in the case of complex solutions, neutral nanostructured surfaces are able to retain all amyloid biomarkers.

     

Characterization of sulfurous acid, sulfite, and bisulfite aerosol systems

Acidic tropospheric aerosols contain inorganic species such as sulfurous acid (H(2)SO(3)). As the main alkaline species, ammonia (NH(3)) plays an important role in the heterogeneous neutralization of these acidic aerosols. An aerosol flow-tube apparatus was used to obtain simultaneous optical and size distribution measurements using FTIR and SMPS measurements, respectively, as a function of relative humidity and aerosol chemical composition. A novel chemiluminescence apparatus was also used to measure ammonium ion concentration [NH(4)(+)]. The interactions between ammonia and hydrated sulfur dioxide (SO(2)·H(2)O) were studied at different humidities and concentrations. SO(2)·H(2)O is an important species as it represents the first intermediate in the overall atmospheric oxidation process of sulfur dioxide to sulfuric acid (H(2)SO(4)). This complex was produced within gaseous, aqueous, and aerosol SO(2) systems. The addition of ammonia gave mainly hydrogen sulfite (SHO(3)(-)) tautomers and disulfite ions (S(2)O(5)(2-)). These species were prevalent at high humidities enhancing the aqueous nature of sulfur(IV) species. Their weak acidity is evident due to the low [NH(4)(+)] produced. Size distributions obtained correlated well with the various stages of particulate compositional development.     

Metallodynameric membranes--toward the constitutional transport of gases

The adequate selection of macromonomers, dialdehyde core connectors and of coordinating metal ions makes possible the generation of metallodynameric materials, allowing the fine modulation of the gas transport through rubbery membranes.     

ortho-Lithium/magnesium carboxylate-driven aromatic nucleophilic substitution reactions on unprotected naphthoic acids

Substitution of an ortho-fluoro or methoxy group in 1- and 2-naphthoic acids furnishing substituted naphthoic acids occurs in good to excellent yields upon reaction with alkyl/vinyl/aryl organolithium and Grignard reagents, in the absence of a metal catalyst without the need to protect the carboxyl (CO(2)H) group. This novel nucleophilic aromatic substitution is presumed to proceed via a precoordination of the organometallic with the substrate, followed by an addition/elimination.     

Effects of addition of nitrogen on bioglass properties and structure

Bioglasses have been developed for use in surgery because of their ability to form a hydroxy-carbonate apatite (HCA) layer on their surface which facilitates bonding to natural bone. However, they do not have sufficient strength for use in load-bearing situations and therefore improving their mechanical properties would allow their use in more robust applications. The purpose of this work was to study the effects of nitrogen addition on the physical and mechanical properties and the structure of oxynitride bioglasses based on the system Na₂O–CaO–SiO₂–Si₃N₄. The density, glass transition temperature, hardness and elastic modulus were measured and observed to increase linearly with nitrogen content. These increases are consistent with the incorporation of N into the glass structure in three-fold coordination with silicon which results in extra cross-linking of the glass network. The characterization of these oxynitride bioglasses using solid state nuclear magnetic resonance ²⁹Si MAS NMR and infrared spectroscopy have shown firstly that all the N atoms are bonded to Si atoms and secondly that this increase in rigidity of the glass network can be explained by the formation of SiO₃N, SiO₂N₂ tetrahedra and Q⁴ units with extra bridging anions at the expense of Q³ units. The oxynitride bioglasses in simulated body fluid form a hydroxy-carbonate apatite (HCA) layer on their surfaces showing that bioactivity is retained.     

Tetrathiafulvalene-triazine-dipyridylamines as multifunctional ligands for electroactive complexes: synthesis, structures, and theoretical study

The electroactive ligands (2,4-bis-tetrathiafulvalene[6-(dipyridin-2'-ylamino)]-1,3,5-triazine) TTF(2)-tz-dpa (1) and (2-tetrathiafulvalene[4,6-bis-(dipyridin-2'-ylamino)]-1,3,5-triazine) TTF-tz-dpa(2) (2) have been synthesized by palladium cross-coupling catalysis, and the single crystal X-ray structure for 1 was determined. In the solid state the TTF and triazine units are practically coplanar and short intermolecular S···S contacts are established. Two neutral and one tetracationic Zn(II) complexes, formulated as (TTF(2)-tz-dpa)ZnCl(2) (3), [ZnCl(2)(TTF-tz-dpa(2))Zn(H(2)O)Cl(2)] (4), and {[(H(2)O)(2)Zn(TTF-tz-dpa(2))](ClO(4))(2)}(2) (5) have been crystallized and analyzed by single crystal X-ray analysis. A peculiar feature is the evidence for anion-π interactions, as shown by the short Cl···triazine and O(perchlorate)···triazine distances of 3.52 and 3.00 ?, respectively. A complex set of intermolecular π···π, S···S, and hydrogen bonding interactions sustain the supramolecular organizations of the complexes in the solid state. Electronic absorption spectra provide evidence for the intramolecular charge transfer from TTF to triazine, also supported by time-dependent density functional theory (TD DFT) calculations.     

Synthesis of a new family of protected 1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derivatives with thioctic acid pending arms

The synthesis and characterization of a new family of ester protected N-substituted [1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (H3DO3A) derivatives containing a pendant thioctic acid (α lipoic acid, LA) are reported. These compounds (DO3A^tBu-NLA, DO3A^tBu-NMeNLA, and DO3A^tBu-NEtNLA) are suitable for the functionalization of gold surfaces with rare-earth complexes.     

Fluctuations of interacting Markov chain Monte Carlo methods

We present a multivariate central limit theorem for a general class of interacting Markov chain Monte Carlo algorithms used to solve nonlinear measure-valued equations. These algorithms generate stochastic processes which belong to the class of nonlinear Markov chains interacting with their empirical occupation measures. We develop an original theoretical analysis based on resolvent operators and semigroup techniques to analyze the fluctuations of their occupation measures around their limiting values.     

A constraint programming approach for a batch processing problem with non-identical job sizes

This paper presents a constraint programming approach for a batch processing machine on which a finite number of jobs of non-identical sizes must be scheduled. A parallel batch processing machine can process several jobs simultaneously and the objective is to minimize the maximal lateness. The constraint programming formulation proposed relies on the decomposition of the problem into finding an assignment of the jobs to the batches, and then minimizing the lateness of the batches on a single machine. This formulation is enhanced by a new optimization constraint which is based on a relaxed problem and applies cost-based domain filtering techniques. Experimental results demonstrate the efficiency of cost-based domain filtering techniques. Comparisons to other exact approaches clearly show the benefits of the proposed approach: it can optimally solve problems that are one order of magnitude greater than those solved by a mathematical formulation or by a branch-and-price.     

Existence of Solutions for a Fractional Derivative System of Equations

We study a fractional derivative system of equations. A Newton polygonal associated with this system is partially described. Under some additional assumptions, this Newton polygonal is fully described and L ² estimates are given, as well as an existence result. We finally discuss our assumptions.