Tolerance space and molecular similarity

Molecular similarity methods were used in selecting K nearest neighbors and in estimating mutagenicity of 95 aromatic amines and boiling points of a large set of over 2,900 compounds. Similarity is analyzed in terms of the concept of tolerance space. Specifically, the role of non-transitivity of the tolerance relation in estimating properties using similarity methods is examined.     

Characterization of poly(vinyl alcohol)/sodium bromide polymer electrolytes for electrochemical cell applications

Sodium‐ion conducting polymer electrolytes based on poly(vinyl alcohol) complexed with sodium bromide were prepared with a solution‐casting technique. The structure of these films was determined with X‐ray diffraction, and the complexation of the salt with the polymer was confirmed with Fourier transform infrared spectroscopy studies. Electrical conductivity was measured with an alternating‐current impedance analyzer in the frequency range of 100 Hz to 1 MHz and in the temperature range of 303–373 K. It was observed that the magnitude of conductivity increased with the increase in the salt concentration as well as the temperature. The nature of the charge transport in these polymer electrolyte films was determined with both Wagner's polarization technique and the Watanabe technique. The dominant conducting species were found to be ions, particularly anions. Optical absorption studies were performed in the wavelength range of 200–600 nm, and the absorption edge, direct band gap, and indirect band gap values were evaluated. Electrochemical cells were fabricated, and their discharge characteristics were studied. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Functional copolymer of geraniol and acrylonitrile: Synthesis and characterization

The radical copolymerization of acyclic terpene namely geraniol [GER] with acrylonitrile [AN] in DMF at (70 ± 0.1)°C for 1 h, using benzoylperoxide (BPO) as an initiator has been carried out under inert atmosphere of nitrogen. The kinetic expression for reaction is R_p ∝ [BPO]^0.5 [AN]^1.0 [GER]^1.0. The IR spectrum of the copolymer shows bands at 3432 and at 2244 cm^?1 due to ? OH group of GER and ? CN group of AN, respectively. The ¹³C‐NMR spectrum shows peaks at 73–75 δ ppm and 116–120 δ ppm due to ? OH group of GER and ? CN group of AN, respectively. The thermogravimetric analysis and differential scanning calorimetry study shows that copolymer is thermally stable up to 407°C and has glass transition temperatures (T_g) 56°C. The reactivity ratios r₁ (AN) and r₂ (GER) have been calculated as 0.05 and 0.005, respectively. The Alfrey‐Price Q‐e parameter for GER has been calculated as 0.094 and ?2.0, respectively. The molecular weights of the copolymers have been evaluated by gel‐permeation chromatography. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Metallurgical Investigation of a Prematurely Failed Concentric Reducer Tube Used in a Hot-Rolling Mill

A concentric reducer tube, which was a part of the top exit roughing hydraulic descaler in a hot strip mill failed prematurely under working pressure. A detailed metallurgical investigation comprising physical examination, optical microscopy, scanning electron microscopy, and electron probe microanalysis was carried out to find out the genesis of the failure. Physical examination revealed cracks located symmetrically around the circumference of the tube that ran along its full length, up to the weld beads at both ends. Optical microscopy of etched samples revealed a banded ferrite-pearlite structure and the existence of forging folds near the change-in-section(160° fillets). Cracks were found to initiate from these forging folds. No structural abnormalities were found in the weld beads and heat-affected zones.     

Synthesis and characterization of acidic properties of Al-SBA-15 materials with varying Si/Al ratios

Al-SBA-15 of varying Si/Al ratios in the range 11.4–78.4 was synthesized using tri-block copolymer P123. The calcined materials were examined by XRD, pore size distribution, surface area, ²⁷Al NMR spectroscopy. The acidity and acid strength distribution were studied using microcalorimetric adsorption of NH₃. The acidic properties were also examined by cumene cracking reaction as a function of Si/Al ratios. Systematic variation of acidity and activity was observed as a function of Si/Al ratio. The initial heats of NH₃ adsorption correlated well with activity indicate that acid sites with ΔH > 100 kJ/mole is responsible for cumene cracking activity. Linear correlations were obtained with total acidity and cumene cracking activities. The tetrahedral aluminum was found to be responsible for the observed acidities and catalytic activities.     

A classification for incidents and accidents in the health-care system

Problems that arise from health-care management, rather than from a disease process, are now recognized as making a substantial contribution to patient morbidity and mortality and to the cost of health care. However, most classifications of these problems do not provide sufficient detail to allow comparisons or to develop better strategies for the prevention, detection and management of these problems. A 'Generic Occurrence Classification' was developed to record their salient features, place them in context and elicit any system or human error-based contributing factors. This was done by an iterative process in which 'natural categories', identified from over 2000 incidents and 800 adverse events, were placed in a hierarchical structure created using software written in Microsoft Visual Basic; data were stored in a Microsoft Access database. This was shown to be a valid and reliable way to compare incidents and accidents from different sources and to allow sufficient detail to be retrieved to develop preventive strategies.     

A model to assess the effectiveness of topical antipruritics

A model has been developed to determine the effectiveness of topical antipruritics. It utilizes controlled, experimentally induced itch and has demonstrated the effectiveness of the direct action on cutaneous receptor sites of a topical anesthetic, benzocaine, in a topical antipruritic formulation, and has been used to differentiate between two effective topical antipruritics. Three studies are presented: The first study examined the reliability of the experimentally induced itch. Several indices of reliability were computed from the data of this first study. Cronbach's alpha was 0.92. Winer's theta also was 0.92. Simple test-retest reliability, computed at intervals of 29 min, 1 day, and 6-7 days, resulted in Pearson correlations of 0.84, 0.73, and 0.60, respectively. In the second study, the model differentiated statistically between the itch relief resulting from the topical application of a formulation with 6% benzocaine and the same formulation without benzocaine. The third study examined 2 known topical antipruritics: one containing 6% benzocaine and the other 1% hydrocortisone. Both topical antipruritics were found to relieve itch; however, the benzocaine antipruritic produced statistically significantly greater itch relief in more subjects than the hydrocortisone antipruritic at both 1 and 30 min after application. These results demonstrate that OTC antipruritics can be differentiated for effectiveness.     

Dependence of mutation induction on fast-neutron energy in a human epithelial teratocarcinoma cell line (P3)

Cultivation of Candida albicans NIH B-792 (serotype B) at high temperature (37 degrees C) for 48 h in yeast extract-containing Sabouraud liquid medium (YSLM) provided the following findings in comparison with the findings obtained after incubation at 27 degrees C. Growth of the blastoconidia of this strain was decreased, with a dry weight of 9%, and the cells were deficient in cytokinesis. The cells did not undergo agglutination with serum factor 5 from a commercially available serum factor kit (Candida Check). Mannan (B-37-M) obtained from the cells cultured at 37 degrees C had partially lost its reactivity against serum factor 4 and lost most of its reactivity against serum factor 5 in an enzyme-linked immunosorbent assay (ELISA) in contrast to that (B-27-M) at 27 degrees C. Both cells and mannan prepared by cultivation first at 37 degrees C and then at 27 degrees C entirely recovered their reactivities with serum factors 4 and 5. 1H-nuclear magnetic resonance analysis also revealed that B-37-M had lost a beta-1,2-linked mannopyranose unit and retained a phosphate group. Similar changes were observed in the three other serotype B strains used in the study. The beta-1,2-linked mannooligosaccharides longer than mannotetraose were not included among the products released from B-37-M by mild acid treatment. The results of the inhibition ELISA with a series of beta-1,2-linked mannooligosaccharides from biose to octaose (M2 to M8, respectively) showed that the reactivity against serum factor 4 was inhibited most strongly by the oligosaccharides M4 to M8 and that the reactivity against serum factor 5 was inhibited completely by relatively longer oligosaccharides, M5 to M8, indicating their participation as the antigenic factor 5 epitopes.     

Neem oil as a sand fly (Diptera: Psychodidae) repellent

The repellent action of neem oil was evaluated against sand flies under laboratory and field conditions. Concentrations of 2% neem oil mixed in coconut or mustard oil provided 100% protection against Phlebotomus argentipes throughout the night under field conditions; against Phlebotomus papatasi it repelled sand flies for about 7 h in the laboratory. Neem oil is an indigenous product and a low-cost alternative for personal protection against sand fly bites.