An Enzyme Immunoassay for Determining Immunoreactive Trypsinogen (IRT) in Dried Blood Spots on Filter Paper Using an Ultra-Microanalytical System

Cystic fibrosis (CF) is a severe autosomal recessive disorder. It is caused by mutations in the CF transmembrane conductance regulator gene. Early diagnosis of CF can be carried out by determining high immunoreactive trypsinogen (IRT) blood values in newborns. A simple sandwich-type ultramicroELISA assay (UMELISA®) has been developed for the measurement of IRT in dried blood spots on filter paper. Strips coated with a high affinity monoclonal antibody directed against IRT are used as solid phase, to ensure the specificity of the assay. The assay is carried out within 20 h. The useful rank of the curve is 0–500 ng/mL, and the lowest detectable concentration is 4.8 ng/mL. Intra- and inter-assay coefficients of variation were lower than 10%. The recovery mean value was 100.3 ± 11.2%. Cross-reactivity with proteins structurally related to IRT (α2-macroglobulin, α1-antitrypsin, and human chymotrypsin) was lower than the detection limit of the assay. Four thousand four hundred six newborn samples from the Cuban Newborn Screening Program were analyzed, and the mean IRT concentration was 12.8 ng/mL. Higher IRT values were obtained when samples were eluted overnight. Regression analysis showed a good correlation with the commercially available AutoDELFIA® Neonatal IRT kit (n?=?3948, r =?0.885, ??=?0.976, p?<?0.01). The analytical performance characteristics of our UMELISA® TIR Neonatal suggest that it can be used for the neonatal screening of CF.     

Thermal Conductivity of Nanocomposites Based in High Density Polyethylene and Surface Modified Hexagonal Boron Nitride via Cold Ethylene Plasma

Hexagonal boron nitride nanoparticles (hBN) were surface modified by treatment with cold ethylene plasma. During this treatment, an ultrathin plasma polymerized polyethylene layer is deposited on the surface of the hBN nanoparticles. Before and after the plasma treatment, the nanoparticles were characterized by infra-red spectroscopy, thermogravimetric analysis, transmission electron microscopy (TEM) and X-ray diffraction. Untreated and plasma treated nanoparticles were incorporated via melt mixing into high density polyethylene (HDPE), at different concentrations. Dispersion of hBN within the polymer and the polymer-particle interaction were studied by TEM. Thermal conductivity of the prepared nanocomposites was determined by modulated differential scanning calorimetry. In general, the thermal conductivity of all HDPE–hBN prepared nanocomposites was higher than that of pure HDPE. However, the higher conductivity values, 97 and 114% higher than that of pure HDPE, were obtained in plasma treated samples (treated at 100 W for 5 min) with 8 and 15 wt% loading of hBN.     

A bidirectional access to novel thiadiazine hybrid molecules by double multicomponent reactions

In an attempt to further exploit multicomponent reactions in the field of hybrid heterocyclic molecules, we describe a bidirectional approach for the synthesis of novel 1,3,5-thiadiazine-peptides molecules. The process relies on the execution of two Ugi reactions between dicarboxy-functionalized 1,3,5-thiadiazine with different amines and isocyanides. An alternative strategy relying on a sequential multicomponent macrocyclization procedure was also developed to afford thiadiazine peptide-like macrocycles. Both methods showed great chemical efficiency and versatility.     

Relativity of topology and dynamics

Recent developments in quantum set theory are used to formulate a program for quantum topological physics. The world is represented in a Hilbert space whose psi vectors represent abstract complexes generated from the null set by one bracket operator and the usual Grassmann (or Clifford) product. Such a theory may be more basic than field theory, in that it may generate its own natural topology, time, kinematics and dynamics, without benefit of an absolute timespace dimension, topology, or Hamiltonian. For example there is a natural expression for the quantum gravitational field in terms of quantum topological operators. In such a theory the usual spectrum of possible dimensions describes only one of an indefinite hierarchy of levels, each with a similar spectrum, describing nonspatial infrastructure. While c simplices have no continuous symmetry, the q simplex has an orthogonal group 0(m, n). Because quantum theory cannot take the universe as physical system, we propose a third relativity:The division between observer and observed is arbitrary. Then it is wrong to ask for the topology and dynamics of a system, in the same sense that it is wrong to ask for the the psi vectors of a system; topology and dynamics, like psi vectors, are not absolute but relative to the observer.     

Hydrogen Bonding of Carboxylic Acids in Aqueous Solutions—UV Spectroscopy, Viscosity, and Molecular Simulation of Acetic Acid

The UV spectra of aqueous acetic acid solutions up to 2M were investigated. At these wavelengths, the carboxylic acids exhibit an absorption peak, attributed to the C=O group, which shifts when hydrogen bonds are formed.. The measured spectra were best fitted to several bands, either of Gaussian or Lorentzian shape, which can be explained as several types of structural units formed by hydrogen bonds established between acetic acid and water molecules and between acetic acid molecules themselves. Molecular dynamics simulation of these mixtures was also performed, confirming the occurrence of several types of hydrogen bonds and showing the presence of dimers at higher concentrations. The viscosity and density of these solutions were also measured at different concentrations and temperatures. These results give a more complete picture of the hydrogen bond network of the system.     

Metallation of Ligands with Biological Activity: Synthesis and X‐ray Characterization of the New Sulfathiazolato Complexes of Gold(I) and Silver(I): [(sulfathiazolato)AuPPh3] and [Ag(sulfathiazolato)]2 (sulfathiazole = N1‐2‐thiazolyl‐sulfanilamide)

Sulfathiazole reacts with [Ph₃PAu(CH₃COO)] in benzene and with Ag(CH₃COO) in methanol giving [(sulfathiazolato)AuPPh₃] ( 1 ) and {[Ag(sulfathiazolato)]₂}_n ( 2 ). While the lattice of 1 contains single molecules with linear N–Au–P bonds, compound 2 performs a polymeric, one‐dimensional assembling of [Ag(sulfathiazolato)]₂ dimers linked through intermolecular Ag···O=S=O interactions along the crystallographic axis b. The silver atoms achieve a tetrahedral configuration through Ag–Ag contacts which measure 2.8427(4) Å, considerably shorter than the normal bonding distance of metallic silver.     

Pelseneeriol-1 and -2: new furanosesquiterpene alcohols from porostome nudibranch Doriopsilla pelseneeri

The paper reports the first chemical study of the porostome nudibranch Doriopsilla pelseneeri collected off the Portuguese coast (Atlantic Ocean). Two new furanosesquiterpene alcohols, pelseneeriol-1 (1) and pelseneeriol-2 (2), have been isolated together with known compounds, 15-acetoxy-ent-pallescensin-A (5), and dendocarbin-A (6), from the mantle of the nudibranch, whereas euryfuran (3) and drimane ester mixture 4 were identified in the extract of the internal glands. The structures of 1 and 2 have been determined by extensive spectroscopic studies as well as by comparison with literature model compounds. In order to assess the relative stereochemistry of 1 and 2, full NMR assignment of related sponge metabolite microcionin-2 (8) and of co-occurring sesquiterpenes 9-11, that have been re-isolated from the Mediterranean sponge Fasciospongia cavernosa, has been also conducted. In particular, the relative stereochemistry of tricyclic sesquiterpene microcionin-1 (9) has now been rigorously assigned by detailed analysis of NOE difference experiments.     

Preparation and Suzuki-Miyaura coupling reactions of tetrahydropyridine-2-boronic acid pinacol esters

[reaction: see text] A study on the conversion of lactam-derived vinyl triflates and phosphates into the corresponding vinyl boronates was carried out. While delta-valerolactam-derived vinyl triflates were successfully converted into 1,4,5,6-tetrahydropyridine-2-boronic acid pinacol ester derivatives by Pd-catalyzed coupling reaction with both bis(pinacolato)diboron and pinacolborane, pyrrolidinone and epsilon-caprolactam derivatives either did not react or were readily reduced. The delta-valerolactam-derived vinyl boronates are thermally stable compounds that efficiently coupled, under Pd catalysis, with structurally diverse aryl and heteroaryl bromides and triflates, vinyl iodides and bromides, and aromatic acid chlorides, to give the corresponding 2-substituted piperidines in good to excellent yields. The number of electrophiles that can virtually be coupled with these new boronic esters makes them very useful reagents for the synthesis of N-heterocyclic compounds.     

Self-doping effect in poly(o-methoxyaniline)/poly(3-thiopheneacetic acid) layer-by-layer films

Nanostructured films from two conducting polymers, poly(o-methoxyaniline) (POMA) and poly(3-thiopheneacetic acid) (PTAA), were fabricated with the layer-by-layer (LBL) technique. The electrochemical response of the LBL films differs from that of a POMA cast film, even in a potential range where PTAA is inactive. This is attributed to differences in the diffusion-controlled charge and mass transport, where distinct ionic species participate in the LBL films, as demonstrated by quartz crystal microbalance measurements. The results show that the transport properties of conducting polymers can be changed by alternation with layers of appropriate materials in LBL films.     

Aqueous room temperature metal-catalyzed living radical polymerization of vinyl chloride

This paper describes the room-temperature living radical polymerization (LRP) of vinyl chloride in H2O/THF in the presence of Cu0 or CuI salts as catalysts, tren or PEI as ligands, and iodoform as initiator. The disproportionation reaction 2CuI + L --> Cu0 + CuII(L) is the crucial step, as it continuously provides the active species for both the initiation (Cu0) and the reversible termination step (CuII). Mn was found to increase linearly with conversion and is in good agreement with Mth, with the Mw/Mn being approximately 1.5.