Dispersion and Confinement Loss Control in Modified Hexagonal Photonic Crystal Fibers

This paper presents a novel technique for the control of chromatic dispersion and confinement loss in hexagonal photonic crystal fibers (H-PCFs). It is demonstrated that it is possible to obtain very low chromatic dispersion of 0 ± 0:38 ps/(nm·km) in the wavelength range of 1.41 to 1.66 μm and confinement loss of less than 0.0001 dB/km from a six ring modified H-PCF (MH-PCF). The higher order dispersion at 1.55 μm is about −0.001 ps/(nm²-km).     

Flattened chromatic dispersion in square photonic crystal fibers with low confinement losses

This research presents a simple index-guiding square photonic crystal fibers (SPCFs) that has a silica core surrounded by air hole with two different diameters. It is demonstrated that the designed two-different-size hole-arrayed index-guiding SPCFs has a ultra-flattened chromatic dispersion of 0 ± 0.9 ps/(nm·km) in a wavelength range of 1.34 to 1.61 μm and low confinement loss of less than 10⁻⁷ dB/m in a wavelength range of 1.2 to 1.7 μm. It has also been shown that the proposed SPCFs show reasonable dispersion tolerance.     

Two-dimensional protein map of human vastus lateralis muscle

Protein samples of human vastus lateralis muscle were analyzed by two-dimensional gel electrophoresis, using immobilized pH gradients encompassing several pH regions in the first dimension and sodium dodecyl sulfate-polyacrylamide gel electrophoresis in the second dimension. More than 500 protein spots on each gel were detected by silver staining, of which 150 were excised, digested in-gel with trypsin and characterized by matrix assisted laser desorptioin/ionization-mass spectrometry and tandem electrospray mass spectrometry. Using these techniques, 124 spots including contractile proteins and metabolic enzymes were identified. This database should provide a valuable resource for the definition of the functional properties of muscle fibres and for assessment of the influence of e.g., hypoxia, ischaemia and ageing on protein level.     

New insecticidal amides from petroleum ether extract of dried Piper nigrum L. whole fruits

The petroleum ether extract of dried ground whole fruits of Piper nigrum L. afforded 20 compounds (1-20) including two new insecticidal amides named as pipnoohine (1), and pipyahyine (2), seven reported for the first time from this plant (12, 13, 15-17, 19, 20), and eleven known compounds (3-11, 14, 18). The structure of 1 has been elucidated as (2E,4E,12Z)-N-(4-methylpentyl)octadeca-2,4,12-trienamide and that of 2 as (2E,4E,11E)-12-(benzo[1,3]dioxol-5-yl)-N-(3-methylbutyl)dodeca-2,4,11-trien-amide through extensive ID-, 2D-NMR spectral studies and chemical reactions. The known compounds have been identified through comparison of their spectral data with those reported in literature. 1 and 2 exhibited toxicity at 35.0 and 30.0 ppm respectively against fourth instar larvae of Aedes aegypti L. by WHO method.     

Piptigrine, a new insecticidal amide from Piper nigrum Linn

A new insecticidal amide piptigrine (1) possessing highly extended conjugation was isolated from the dried ground seeds of Piper nigrum Linn. along with the known amides piperine and wisanine (hitherto unreported from this plant). The structure of 1 has been elucidated as 1-[9-(3',4'-methylenedioxyphenyl)-4E,6E,8E-nonatrienoyl]piperidine through extensive 1D- and 2D-NMR (COSY-45, NOESY, J-resolved, HMQC, HMBC and NOESY studies. The known compounds have been identified through comparison of their spectral data with those reported in literature. 1 exhibited toxicity of 15.0 ppm against fourth instar larvae of Aedes aegypti Liston.     

Isolation and structure determination of a benzofuran and a bis-nor-isoprenoid from Aspergillus niger grown on the water soluble fraction of Morinda citrifolia Linn. leaves

The leaves of Morinda citrifolia, Linn. afforded a new benzofuran and a bis-nor-isoprenoid, blumenol C, hitherto unreported from this source. The structures of these have been elucidated as 5-benzofuran carboxylic acid-6-formyl methyl ester (1) and 4-(3'(R)-hydroxybutyl)-3,5,5, trimethyl-cyclohex-2-en-1-one (2) respectively through spectroscopic studies. The NMR data (including 1D, 2D techniques) and stereochemistry at C-3' of Compound 2 is also being reported for the first time.     

Theoretical insight of nitric oxide adsorption on neutral and charged Pdn (n = 1–5) clusters

Density functional theory (DFT) calculations within the framework of generalized gradient approximation have been used to systematically investigate the adsorption of nitric oxide (NO) molecule on neutral, cationic, and anionic Pd_n (n = 1–5) clusters. NO coordinate to one Pd atom of the cluster by the end‐on mode, where the tilted end‐on structure is more favorable due to the additional electron in the π* orbital. On the contrary, in the neutral and cationic Pd₂ system, NO coordinates to the bridge site of cluster preferably by the side‐on mode. Charge transfer between Pd clusters and NO molecule and the corresponding weakening of N? O bond is an essential factor for the adsorption. The N? O stretching frequency follow the order of cationic > neutral > anionic. Binding energy of NO on anionic clusters is found to be greater than those of neutral and cationic clusters. © 2015 Wiley Periodicals, Inc.     

Reaction of [Ru3(CO)12] with tri(2-furyl)phosphine: Di- and tri-substituted triruthenium and phosphido-bridged diruthenium complexes

Reaction of [Ru₃(CO)₁₂] with tri(2-furyl)phosphine, P(C₄H₃O)₃, at 40 °C in the presence of a catalytic amount of Na[Ph₂CO] furnishes two triruthenium complexes [Ru₃(CO)₁₀{P(C₄H₃O)₃}₂] (1) and [Ru₃(CO)₉{P(C₄H₃O)₃}₃] (2) with the ligand coordinated through the phosphorus atom. Treatment of 1 and 2 with Me₃NO at 40 °C affords the dinuclear phosphido-bridged complexes [Ru₂(CO)₆(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}] (3) and [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(C₄H₃O)₃}] (4), respectively, that are formed via phosphorus–carbon bond cleavage of a coordinated phosphine followed by coordination of the dissociated furyl moiety to the diruthenium center in a σ,π-alkenyl mode. Reaction of [Ru₃(CO)₁₂] with tri(2-furyl)phosphine in refluxing benzene gives, in addition to 3 and 4, low yields of the cyclometallated complex [Ru₃(CO)₉{μ-η¹,η¹-P(C₄H₃O)₂(C₄H₂O)}₂] (5). Treatment of 3 with EPh₃ (E = P, As, Sb) at room temperature yields the monosubstituted derivatives [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}(EPh₃)] (E = P, 8; E = As, 9; E = Sb, 10). Similar reactions of 3 with P(C₄H₃O)₃, P(OMe)₃ and Bu^tNC yield 4, [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(OMe)₃}] (11) and [Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}(NCBu^t)] (12), respectively. The molecular structures of complexes 3, 4 and 8 have been elucidated by single crystal X-ray diffraction studies. Each complex contains a bridging σ,π-alkenyl group and while in 4 the phosphine is bound to the σ-coordinated metal atom, in 8 it is at the π-bound atom. Protonation of 3 and 4 gives the hydride complexes [(μ-H)Ru₂(CO)₆(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}]⁺ (6) and [(μ-H)Ru₂(CO)₅(μ-η¹,η²-C₄H₃O){μ-P(C₄H₃O)₂}{P(C₄H₃O)₃}]⁺ (7), respectively, while heating 3 with dimethylacetylenedicarboxylate (DMAD) in refluxing toluene gives the cyclotrimerization product, C₆(CO₂Me)₆.     

Tunable Surface Wrinkling by a Bio-Inspired Polyamine Anion Coacervation Process that Mediates the Assembly of Polyoxometalate Nanoclusters

A bio-inspired method is used to render controlled wrinkling surface patterns on supramolecular architectures assembled from polyoxometalate (POM) clusters. It involves a polyamine-multivalent anion interaction generating positively charged coacervates, which while dictating the assembly of POM into spherical structures further facilitate an interesting surface morphogenesis with wrinkling patterns. This spontaneous surface wrinkling depends on the type of multivalent anion and the pH. As the polyamine-anion interaction becomes stronger, the wrinkles turn denser with lesser depth, which eventually undergoes post-buckling to engender a complex surface pattern. Interestingly, the order of influence exerted by different anions on the morphology follows the Hofmeister series. Moreover, the mild synthesis conditions keep the functional POM units dispersed in the sphere with a structural transformability to their lacunary form.