Bonding in palladium(II) and platinum(II) allyl MeO- and H-MOP complexes. Subtle differences via C-13 NMR

C-13 NMR studies have shown that in both Pd(II)- and Pt(II)-allyl (modified-MOP) (MOP = (S)-2-diarylphosphino-1,1'-binaphthyl) complexes the substituent on the MOP auxiliary can affect how the naphthyl backbone interacts with a metal center. With the MeO-MOP analogue, the metal binds the carbon in a weak eta(1)-fashion, whereas with H-MOP it prefers an eta(2)-binding mode. For the Pt complexes, the (1)J(Pt-195,C-13) values proved to be diagnostic tools. Both modes of bonding afford relatively weak bonds to the metal. Modifying the MOP ligand structure from a PPh2 to a P(3,5-di-tert-butylphenyl)2 analogue can markedly affect the bond distances within the coordination sphere, as indicated by the X-ray structural data for PdCl(eta(3)-C3H5)(modified-MOP). 2-D NMR exchange spectroscopy can be used to recognize and distinguish between the two most common types of eta(3)-eta(1)-eta(3) isomerization process, i.e., rotation around the allyl C-C bond versus rotation around the allyl M-C bond. For the complex PdCl(eta(3)-C3H5)(H-MOP), the fastest isomerization process involves rotation around the allyl C-C bond

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Not AvailableHibiscus sabdariffa L. is a bast fibre crop bearing edible calyx. In the present study we characterized geographically diverse accessions (124) of H. sabdariffa var. altissima (HSA) and H. sabdariffa var. sabdariffa (HSS) using 23 morpho-metric (10 qualitative, 13 quantitative) traits and 19 microsatellite based markers (11 ISSRs; 8 SSRs). Wide spectrum diversity for agro-morphological traits recorded. Principal component analysis using 13 quantitative traits explained 99.30% of the total variation in the data by first four axes. A total of 91 polymorphic bands were yielded by microsatellite based markers (60 by ISSRs and 31 by SSRs) from them SSRs revealed more polymorphism (PIC = 0.32, polymorphism = 96.87%). The ISSR marker namely U818 exhibited highest primer index (ISPI = 2.275) whereas, SSR marker HA-8 reported highest PIC value (0.495). However, the highest genetic diversity at species level exhibited by ISSR markers (Shannon’s index = 0.519, heterozygosity = 0.353). Different diversity parameters, structure and cluster analysis employed in the present study demonstrated more genetic diversity of fibre type roselle accessions (HSA) than calyx type (HSS). Moreover, employed agro-morphological traits and molecular markers complemented each other and imparted greater resolution to understand genetic diversity of roselle plant genetic resources in toto.Not Availabl

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Not AvailableIn search of causal factors underlying perceived allogamy in sunnhemp (Crotalaria juncea L.), we investigated the breeding system and pollen–pistil interaction. Floral biology study in the species established Fabaceae type hermaphrodite zygomorphic flower with dimorphic anthers. Study of the breeding system revealed preferential success of allogamy despite delayed autonomous selfing mechanism characteristically prevailing in the species. Pollen–pistil interaction study in selfed and crossed pistils revealed significant differences in pollen tube growth rates inside the pistil. Further, in self-pollinated pistils callose formation observed at and around nucellus cells suggesting the late-acting type of selfincompatibility mechanism in the species. To the best of our knowledge, this is the first scientific communication underscoring the prevalence of self-incompatibility mechanism in sunnhemp.Not Availabl

Toward an Understanding of the Anion Effect in CpRu-Based Diels-Alder Catalysts via PGSE-NMR Measurements

The rate dependence of the [Ru(η5-C5H5)(BIPHOP-F)(acetone)][Y]-catalyzed Diels-Alder reaction of cyclopentadiene with methacrolein on the anion, Y, is shown to be due to selective ion pairing. Pulsed gradient spin-echo (PGSE) diffusion measurements on the model Cp and indenyl complexes [Ru(η5-C5H5)(CH2CH==CN)(BIPHOP-F)][Y], Y = BF4 and BArF, and [Ru(η5-C9H7)(CH2CH==CN)(BIPHOP-F)][Y], Y = BF4 and BArF, respectively, combined with 1H-19F HOESY NMR data can be used to understand how the ion pairing for the BF4 anion differs relative to that of the BArF anion. Solid-state structures for [Ru(η5-C5H5)(CH2CH==CN)(BIPHOP-F)][BF4] and [Ru(η5-C5H5)(CH2CH==CN)(BIPHOP-F)][BArF] are reported and support the NMR solution data. The model carbonyl complexes [Ru(η5-C5H5)(BIPHOP-F)(CO)][Y], 8 (Y = BF4, SbF6, and BArF) have been synthesized. The IR CO stretching frequencies for 8 showed little variation with anion, thereby proving that the anions do not affect the Lewis acidity of the salts

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Not AvailableA total of 130 flax accessions of diverse morphotypes and worldwide origin were assessed for genetic diversity and population structure using 11 morphological traits and microsatellite markers (15 gSSRs and 7 EST–SSRs). Analysis performed after classifying these accessions on the basis of plant height, branching pattern, seed size, Indian/foreign origin into six categories called sub-populations viz. fibre type exotic, fibre type indigenous, intermediate type exotic, intermediate type indigenous, linseed type exotic and linseed type indigenous. The study assessed different diversity indices, AMOVA, population structure and included a principal coordinate analysis based on different marker systems. The highest diversity was exhibited by gSSR markers (SI = 0.46; He = 0.31; P = 85.11). AMOVA based on all markers explained significant difference among fibre type, intermediate type and linseed type populations of flax. In terms of variation explained by different markers, EST-SSR markers (12%) better differentiated flax populations compared to morphological (9%) and gSSR (6%) markers at P = 0.01. The maximum Nei’s unbiased genetic distance (D = 0.11) was observed between fibre type and linseed type exotic subpopulations based on EST-SSR markers. The combined structure analysis by using all markers grouped Indian fibre type accessions (63.4%) in a separate cluster along with the Indian intermediate type (48.7%), whereas Indian accessions (82.16%) of linseed type constituted an independent cluster. These findings were supported by the results of the principal coordinate analysis. Morphological markers employed in the study found complementary with microsatellite based markers in deciphering genetic diversity and population structure of the flax germplasmNot Availabl

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Health-status outcomes with invasive or conservative care in coronary disease

BACKGROUND In the ISCHEMIA trial, an invasive strategy with angiographic assessment and revascularization did not reduce clinical events among patients with stable ischemic heart disease and moderate or severe ischemia. A secondary objective of the trial was to assess angina-related health status among these patients. METHODS We assessed angina-related symptoms, function, and quality of life with the Seattle Angina Questionnaire (SAQ) at randomization, at months 1.5, 3, and 6, and every 6 months thereafter in participants who had been randomly assigned to an invasive treatment strategy (2295 participants) or a conservative strategy (2322). Mixed-effects cumulative probability models within a Bayesian framework were used to estimate differences between the treatment groups. The primary outcome of this health-status analysis was the SAQ summary score (scores range from 0 to 100, with higher scores indicating better health status). All analyses were performed in the overall population and according to baseline angina frequency. RESULTS At baseline, 35% of patients reported having no angina in the previous month. SAQ summary scores increased in both treatment groups, with increases at 3, 12, and 36 months that were 4.1 points (95% credible interval, 3.2 to 5.0), 4.2 points (95% credible interval, 3.3 to 5.1), and 2.9 points (95% credible interval, 2.2 to 3.7) higher with the invasive strategy than with the conservative strategy. Differences were larger among participants who had more frequent angina at baseline (8.5 vs. 0.1 points at 3 months and 5.3 vs. 1.2 points at 36 months among participants with daily or weekly angina as compared with no angina). CONCLUSIONS In the overall trial population with moderate or severe ischemia, which included 35% of participants without angina at baseline, patients randomly assigned to the invasive strategy had greater improvement in angina-related health status than those assigned to the conservative strategy. The modest mean differences favoring the invasive strategy in the overall group reflected minimal differences among asymptomatic patients and larger differences among patients who had had angina at baseline