The diagnostic capacity of serum amyloid A protein for early recognition of kidney allograft rejection

Chitosan derivatives, sulfated N-acyl-chitosan (S-Cn-chitosan) possessing various lengths of alkyl chain, were prepared, and the properties of their aqueous solutions were examined. The 1H-NMR spectrum of D2O solutions of S-C12-chitosan showed broadening of the proton signals caused by aggregation of the alkyl chain. The solubility of a hydrophobic compounds, azobenzene, was small in the aqueous solutions of S-Cn-chitosan with shorter alkyl chains, but increased with increasing length of the chains above C10, showing that micelles had been formed. The ESR spectrum of a spin probe, TEMPO, in an S-C14-chitosan solution showed the existence of a hydrophobic region in the solution, but this region did not exist in the S-C2-chitosan solution. The rigidity of this region was examined by using a spin probe, 16-doxyl-stearic acid. From these results, it was revealed that S-Cn-chitosan with longer alkyl chains formed a novel type of micelle called a "polymer micelle," which was more stable than the ordinary micelles formed from low-molecular-weight surfactants.     

Docosahexaenoic acid and traumatic brain injury

Traumatic brain injury (TBI) is becoming increasingly recognised as a major cause of disability, with a significant impact on health costs both in the developed and developing world. At present, there is no effective treatment for this type of acute neurological injury. Docosahexaenoic acid (DHA) is an abundant polyunsaturated fatty acid in the brain, known to have a significant structural role as well as functional roles. Preclinical accumulating evidence indicates that DHA has potential as a restorative therapeutic agent for traumatic brain injury.     

Thermally reversible cross-links in a healable polymer: Estimating the quantity,rate of formation,and effect on viscosity

The conversion behavior of 2MEP4FS, a polymer with thermally reversible Diels–Alder cross-links, is modeled. A processing method is developed to create small, homogeneous prepolymer samples. The glass transition temperature of the prepolymer is estimated using temperature modulated differential scanning calorimetry and equated with the conversion of the polymer. Comparing the measured energy with the literature and computational estimates, the fully cured polymer appears to have a large portion of its moieties unreacted. An autocatalytic model is considered to approximate the reaction rate of 2MEP4FS as a function of conversion and temperature. Outside of the fitted temperature range, the model underpredicts the reaction rates at room temperature and 100 °C. Manual mixing of the monomers is determined to be inadequate to obtain a maximum level of cross-linking. Viscosity measurements made at room temperature and elevated temperatures are correlated with the conversion of the prepolymer.     

Velocardiofacial manifestations and microdeletions in schizophrenic inpatients

Sigma receptors are found in motor and limbic areas in the brains of humans, non-human primates, and rodents. The most extensive pharmacological studies of ligand binding to sigma receptors have utilized brain tissue from guinea pigs, where two subtypes of sigma receptor, designated sigma1 and sigma2, have been identified. Few functional roles for sigma receptors have been described. Their location in guinea pig striatum, a terminal field of dopaminergic projections arising from the substantia nigra, suggested that this tissue would be a logical choice in which to examine physiological properties of sigma receptor activation. We found that sigma1 receptor agonists inhibited N-methyl-D-aspartate-stimulated [3H]dopamine release from guinea pig striatal slices in a concentration-dependent manner. The inhibition by sigma1 receptor agonists was reversed by a selective sigma1 receptor antagonist, as well as by a non-subtype-selective sigma receptor antagonist. The ability of agonists working through sigma1 receptors, but not through sigma2 receptors, to inhibit the stimulated release of catecholamines appears to be a unique characteristic of guinea pig striatum. We have previously reported that in rat striatum and hippocampus, as well as in guinea pig nucleus accumbens, prefrontal cortex, and hippocampus, activation of either sigma receptor subtype inhibits such release. Stimulated release of [3H]dopamine from guinea pig striatum was also inhibited by the phencyclidine receptor agonist dizocilpine, but this inhibition was not reversed by the sigma receptor antagonists. Therefore, the inhibition produced by sigma receptor agonists was not mediated via the phencyclidine binding site within the N-methyl-D-aspartate-operated cation channel. Our findings support the hypothesis that sigma receptor activation provides a mechanism of modulating dopamine release from striatum, and that striatal tissue from guinea pigs appears to be an appropriate model for characterizing sigma1 receptor-mediated effects.     

Comparison of different modes of excitation in X-ray emission spectroscopy in the detection of trace elements in coal and coal ash

Three different modes of sample excitation in X-ray emission spectroscopy were used in trace element analysis of coal and coal ash: proton beam, Mo X-ray tube and radioactive sources ⁵⁷Co and ¹⁰⁹Cd. The results of analysis are presented and methods and their possibilities are compared in order to indicate the most appropriate technique for the particular purpose.     

Lateral preference in post-traumatic stress disorder

Two sets of experiments on the role of tea in azoxymethane (AOM) induced colon cancer were performed. The first test involved male F344 rats given 1.25% solutions of black tea beginning at 5 weeks of age and ending at 51 days of age. At 6 and 7 weeks of age, they received 15 mg/kg AOM and were held for 50 weeks. Another group received the AOM dosage at 6 and 7 weeks and were placed on the tea solutions 2 days after the last AOM dosage, at 51 days of age, and held for the 50-week period. The end point was the occurrence and multiplicity of colon cancer, classified as in situ, exophytic, invasive and Peyer's patch carcinomas. Tea failed to affect the incidence and multiplicity of colon cancers when given during or after the AOM administration, but tea after AOM increased the multiplicity of exophytic carcinomas. In a second series of tests, solutions of 0.6, 1.25, 1.75 or 2.5% tea were given, beginning 1 week prior to the two AOM doses and extending for 42 weeks. Also, one group received 1.25% tea and 1.85% whole milk. The incidence of exophytic or invasive colon cancer and tumor multiplicity were similar in all treatment groups, although the incidence of exophytic neoplasms was higher with 2.5% tea. Thus, chronic administration failed to significantly change the incidence and multiplicity of the AOM-induced colon cancers. These findings are accounted for by the underlying mechanism, namely the fact that tea solutions do not alter the amount of cytochrome P-4502E1 required for the metabolic activation of AOM.     

Forensic Architecture

The urban destruction captured by black and white photos of London after the Blitz or bomb-damaged Berlin are emblematic of the desolation brought by modern warfare. Eyal Weizman , Paulo Tavares , Susan Schuppli and Situ Studio describe, though, how the built environment now represents more than a means of violation in conflict, as it has become an important source of evidence bearing witness to the event when international justice is sought. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of brominated epoxy on epoxy/phenolic reactive blends

Innovative reactive blends containing epoxy and brominated epoxy (BE) incorporated with resole-type phenolic were studied with the aim to elucidate the curing kinetics and the final thermomechanical characteristics of this unique system. Curing kinetics was investigated by means of the activation energy determined using differential scanning calorimetry (DSC ) at various heating rates analyzed by the Arrhenius equation. Both DSC and Fourier transform infrared revealed that bromine elimination at elevated temperatures (above 220 °C) had lowered the activation energy in the case of BE containing phenolic blends. The thermomechanical properties showed that the addition of conventional epoxy to resole decreased its thermal properties and modulus compared to neat resole. Distinctively, BE/resole blends exhibited increased glass-transition temperature, compared to diglycidyl ether of bisphenol A/resole blends in combination with higher elongation and toughness compared to neat resole. It was concluded that BE/epoxy resin/phenolic reactive systems offer high T _g, mechanical properties and toughness and hence are applicable for structural adhesives and for matrices of polymer-fiber composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47172.     

Toughening of epoxy systems by brominated epoxy

Blends of brominated epoxy (BE) and conventional epoxy resins were studied following curing with aliphatic triethylenetetramine (TETA), etheric (polyether diamine‐ PEA4), and aromatic (3,3′‐diamino diphenyl sulfone [DDS]) hardeners. The addition of BE resulted in an increase in T_g in all tested blends. Blends with 50 wt% BE cured with TETA demonstrated an increase in flexural modulus and flexural strength, while preserving the elongation. Blends with 40 wt% BE cured with PEA4 and 50 wt% BE cured with DDS resulted in a significant enhanced tensile elongation. The shear strength of all cured systems decreased moderately with the addition of BE exhibiting a mixed mode failure. Analysis of the fracture morphology using electron microscopy supported the increase of toughness levels as a result of incorporating BE to conventional epoxy. A unique nodular and rough fracture morphology was obtained, which is related to a toughening mechanism caused by the addition of BE. It was concluded that blends of BE and conventional epoxy could be used as structural adhesives having high T_g, enhanced mechanical properties and increased toughness. POLYM. ENG. SCI., 59:206–215, 2019. © 2018 Society of Plastics Engineers     

Quantitative analysis of cascade impactor samples – revisited

Concentrations of aerosols collected in Singapore during the three months long haze period that affected the whole South-East Asian region in 1997 are reported. Aerosol samples were continuously collected by using a fine aerosol sampler (PM2.5) and occasionally with a single orifice cascade impactor (CI) sampler. Our results show that in the fine fraction (<2.5 μm) the concentrations of two well-known biomass burning products, i.e. K and S were generally increased by a factor 2–3 compared to the non-hazy periods. However, a discrepancy was noticed, at least for elements with lower atomic number (Ti and below) between the results obtained by the fine aerosol sampler and the cascade impactor. Careful analysis by means of Nuclear Microscopy, in particular by the Scanning Transmission Ion Microscopy (STIM) technique, revealed that thicknesses of the lower CI stages exceeded thick target limits for 2 MeV protons. Detailed depth profiles of all CI stages were therefore measured using the STIM technique and concentrations corrected for absorption and proton energy loss. After correcting results for the actual sample thickness, concentrations of all major elements (S, Cl, K, Ca) agreed much better with the PM2.5 results. The importance of implementing thick target corrections in analysis of CI samples, especially those collected in the urban environments, is emphasized. Broad beam PIXE analysis approach is certainly not adequate in these cases.