Hybrid (plasma + gas tungsten arc) weldability of modified 12% Cr ferritic stainless steel

This paper deals with the hybrid (plasma + gas tungsten arc) welding properties of 12 mm thick modified 12% Cr ferritic stainless steel complying with EN 1.4003 and UNS S41003 steels with a carbon content of 0.01% to improve the weldability. The root passes of the butt welds were produced with plasma arc welding (PAW) without filler metal while gas tungsten arc welding (GTAW) was used to accomplish filler passes with 309 and 316 austenitic stainless steel type of consumables, respectively. The joints were subjected to tensile and bend tests as well as Charpy impact toughness testing at −20 °C, 0 °C and 20 °C. Examinations were carried out in terms of metallography, chemical analysis of the weld metal, ferrite content, grain size and hardness analyses. Although 309 consumables provided higher mean weld metal toughness values compared to 316 (90 J vs. 75 J), 316 type of consumables provided better mean HAZ toughness data for the joints (45 J vs. 20 J) at −20 °C. Toughness properties of the welds correspond with those of microstructural features including grain size and ferrite content.     

Comparative tear concentrations of topically applied ciprofloxacin, ofloxacin, and norfloxacin in human eyes

The tear pharmacokinetic profiles of 0.3% ciprofloxacin, 0.3% ofloxacin, and 0.3% norfloxacin ophthalmic solutions after a single drop topically administrations in the eyes of 30 healthy volunteers were evaluated. Tear samples collected at 30, 120, 180, and 240 minutes, were analyzed for drug concentrations by high performance liquid chromatography (HPLC) with fluorometric detection. Topically applied ciprofloxacin, ofloxacin, and norfloxacin achieved the mean tear concentrations (mean +/- SD) of 11.28 +/- 6.98, 6.52 +/- 4.06, and 13.28 +/- 8.78 micrograms/g at 30 min, and then fell to 3.52 +/- 1.30, 4.82 +/- 1.80, and 5.79 +/- 4.80 micrograms/g at 240 min, respectively. Topical norfloxacin achieved mean tear level significantly higher than ofloxacin at 30 min (p = 0.031). There were no statistically significant differences in the mean tear levels of ciprofloxacin versus ofloxacin (at 30, 120, 180, and 240 min), ciprofloxacin versus norfloxacin (at 30, 120, 180, and 240 min) and ofloxacin versus norfloxacin (at 120, 180, and 240 min). However, the mean tear levels, 240 min after dosing ciprofloxacin and norfloxacin, fell to the statistically significant concentrations (p = 0.02 and p = 0.01, respectively). But, it is concluded that concentrations of ciprofloxacin, ofloxacin, and norfloxacin in tears were still significantly greater than the minimum inhibitory concentrations for the most sensitive organisms, 240 min after a single drop application.     

A novel molecular determinant for cAMP-dependent regulation of the frog heart Na+-Ca2+ exchanger

Na+-Ca2+ exchanger is one of the major sarcolemmal Ca2+ transporters of cardiac myocytes. In frog ventricular myocytes the exchanger is regulated by isoproterenol via a beta-adrenoreceptor/adenylate-cyclase/cAMPdependent signaling pathway providing a molecular mechanism for the relaxant effect of the hormone. Here, we report on the presence of a novel exon of 27-base pair insertion, which generates a nucleotide binding motif (P-loop) in the frog cardiac Na+-Ca2+ exchanger. To examine the functional role of this motif, we constructed a full-length frog heart Na+-Ca2+ exchanger cDNA (fNCX1a) containing this exon. The functional expression of fNCX1a in oocytes showed characteristic voltage dependence, divalent (Ni2+, Cd2+) inhibition, and sensitivity to cAMP in a manner similar to that of native exchanger in frog myocytes. In oocytes expressing the dog heart NCX1 or the frog mutant (DeltafNCX1a) lacking the 9-amino acid exon, cAMP failed to regulate Na+-dependent Ca2+ uptake. We suggest that this motif is responsible for the observed cAMP-dependent functional differences between the frog and the mammalian hearts.     

Persistent vacuoles in leukocytes: familial Jordans anomaly

DNA typing of HLA-DRB1 genes was conducted for 192 samples from the Gidra who speak one of the non-Austronesian languages and inhabit the southern lowlands of New Guinea. Comparison of the allele frequencies with those of eight other Oceanian populations reveals that the Gidra are genetically closest to the non-Austronesian-speaking Goroka and, next, to the Aboriginal Australian groups, but are remote from the Austronesian-speaking groups in mainland New Guinea and the rest of Melanesia. This finding clearly supports the hypothesis that non-Austronesians and Aboriginal Australians are descendants of the first-stage migrants to Oceania.     

Algorithmic Computation and Approximation of Semantic Similarity

Automatic extraction of semantic information from text and links in Web pages is key to improving the quality of search results. However, the assessment of automatic semantic measures is limited by the coverage of user studies, which do not scale with the size, heterogeneity, and growth of the Web. Here we propose to leverage human-generated metadata—namely topical directories—to measure semantic relationships among massive numbers of pairs of Web pages or topics. The Open Directory Project classifies millions of URLs in a topical ontology, providing a rich source from which semantic relationships between Web pages can be derived. While semantic similarity measures based on taxonomies (trees) are well studied, the design of well-founded similarity measures for objects stored in the nodes of arbitrary ontologies (graphs) is an open problem. This paper defines an information-theoretic measure of semantic similarity that exploits both the hierarchical and non-hierarchical structure of an ontology. An experimental study shows that this measure improves significantly on the traditional taxonomy-based approach. This novel measure allows us to address the general question of how text and link analyses can be combined to derive measures of relevance that are in good agreement with semantic similarity. Surprisingly, the traditional use of text similarity turns out to be ineffective for relevance ranking.     

Non‐covalent interactions of pyrene end‐labeled star poly(ɛ‐caprolactone)s with fullerene

Pyrene end‐labeled star poly(?‐caprolactone)s (PCLs) with polyhedral oligomeric silsesquioxane (POSS) core were prepared by combination of copper(I)‐catalyzed azide–alkyne cycloaddition (CuAAC) click chemistry and ring‐opening polymerization techniques. First, ?‐caprolactone (?‐CL) is polymerized by using 1‐pyrene methanol as initiator and stannous octoate as catalyst to obtain α‐pyrene‐ω‐hydroxyl telechelic PCL with different chain lengths. Then, its hydroxyl group is converted to acetylene functionality by esterification reaction with propargyl chloroformate. Finally, the CuAAC click reaction of α‐pyrene‐ω‐acetylene telechelic PCL with POSS‐(N₃)₈ leads to corresponding pyrene end‐labeled star‐shaped PCLs. The successful synthesis of pyrene end‐labeled star polymers is clearly confirmed by ¹H‐nuclear magnetic resonance, Fourier transform infrared, gel permeation chromatograph, differential scanning calorimeter, and thermogravimetric analysis. Furthermore, non‐covalent interactions of obtained star polymers with fullerene are investigated in liquid media. Based on Raman spectroscopy and visual investigations, the star polymer having shorter chain length exhibited better and more stable dispersion with fullerene. The amount of pyrene units present per polymer chains can directly influence the dispersion stability of fullerene. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46520.     

Structural,magnetic, electrical,and electrochemical properties of Sr–Co–Ru–O: A hybrid‐capacitor application

In this study, we report the synthesis of SrCo_1?xRu_xO_3?δ nominal compositions, where x = 0.0‐1.0, using solid‐state reaction technique. XRD analysis confirms the structure of x = 0 sample as hexagonal Sr₆Co₅O₁₅. As the Co ions are substituted by Ru, a two‐phase structure (hexagonal R32 and orthorhombic Pbnm) emerges up to x ≤ 0.5. As the Ru content is increased further, the hexagonal R32 phase disappears completely and an orthorhombic Pbnm phase becomes the main phase. SEM images show that grain size of the samples decreases with increasing Ru content. Temperature‐dependent electrical conductivity studies indicate upon Ru substitution in the nominal SrCo_1?xRu_xO_3?δ compounds, resistivity decreases due to appearance of metallic SrRuO₃ phase. The cyclic voltammogram (CV) of the samples show capacitive properties upon Ru substitution. The cycle measurements of the capacitors yield promising results for potential supercapacitor applications.     

Synthesis,characterization, and Pb2+ ion sensing application of hexa‐armed dansyl end‐capped poly(ε‐caprolactone) star polymer with phosphazene core

Novel hexa‐armed dansyl end‐capped poly(ε‐caprolactone) (PCL) star polymer with phosphazene core ( P2 ) was prepared via ring opening polymerization (ROP) and esterification reactions. P2 showed dual fluorescence emission when excited at 328 nm in acetonitrile : water (6 : 4) due to twisted intramolecular charge transfer (TICT) between dimethylamino and naphthalene units in the dansyl moiety. TICT emission band (A band) in the emission spectra red‐shifted with increasing solvent polarity. P2 responded to the addition of Pb²⁺, Hg²⁺, Co²⁺, Cd²⁺, Mn²⁺, and Zn²⁺ metal ions by decreasing TICT emission band with slight bathochromic shifts. The highest quenching efficiency was observed for Pb²⁺ ion with Stern–Volmer constant of 324.74M^?1. The Stern–Volmer plot for Pb²⁺ was rather linear with the increasing concentration of the quencher, indicating a dynamic (collisional) quenching mechanism. Stern–Volmer constants for Hg²⁺, Co²⁺, Cd²⁺, Mn²⁺, and Zn²⁺ ions were found to be 212.33, 189.21, 36.24, 20.84, and 20.69, respectively. Besides, the highest quenching efficiency (94.24%) was attained in the presence of Pb²⁺, suggesting that P2 could be employed as a potential Pb²⁺ chemical probe. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42380.