857 research outputs found
Synthesis & anticonvulsant activity of some condensed imidazoles
2-Mercapto-4,5-dihydroimidazole (la), 2-mercapto-3,4,5,6-tetrahydropyrimidine (lb) and 2-mer-_capto-3,4,5,6-tetrahydro-7H-l,3-diazepine (1c) react with methyl iodide to give the corresponding mercaptomethyl derivatives (2a-2c). Reaction of these mercaptomethyl compounds with aminoacetaldehyde diethyl acetal followed by treatment with hydrochloric acid affords lH-2,3-dihydroimidazo[l,2-a]imidazole (4), 5,6,7,8-tetrahydroimidazo[l,2-a]pyrimidine (19) and 9H-5,6,7, 8-tetrahydroimidazo[l,2-a]-[l,3]-diazepine (22), respectively. These condensed imidazoles have been reacted with aromatic acid chlorides, isocyanates and isothiocyanates. The structure and anticonvulsant activity of these compounds are described
Nitroimidazoles: Part XI. Some Halonitro- & dinitroimidazoles
Methylation of 2-chloro-4-nitroimidazole (6), obtained from imidazole in four steps, either with dimethyl sulphate or with diazomethane affords a mixture of 2-chloro-l-methyl-5-nitroimidazole (10) and the 4-nitro-isomer (7). The corresponding dinitro compounds 11 and 8 are formed in the methylation of 2,4-dinitroimidazole (5), 8 being converted to 7 by the action of POCl3. Reaction of 10 with the sodium salt of N-methanesulphonyl-2-imidazolidinone provides the potent amoebicide, 1-methylsulphonyl-3-(1-methyl-5-nitroimidazol-2-yl)-2-imidazolidinone (2). The isomer 14 is synthesised from 7 in low yield. Ethylation of 5 leads to preponderant N-alkylation, providing a mixture of l-ethyldinitroimidazoles (9) and (12), but a small amount of N,C-diethyl derivative 15 is also obtained. The formation of 15 from 5 is rationalised. The diiodination product of imidazole is shown to be 4,5-diiodoimidazole (19), nitric acid transforming it to 4-iodo-5-nitroimidazole (20). Methylation of 20 affords a mixture of isomeric 1 -methyliodonitro derivatives (21) and (22). The structures of 21 and 22 are established by 13C NMR data as well as by conversion into morpholine derivatives 26 and 24 respectively which also arise from 1-methylchloronitroimidazoles (25) and (23). A mechanism is proposed for the reported conversion of 5 into 4-chloro-5-nitroimidazole (32) in boiling 2-chloroethanol
Database on nutritional composition of food fishes from India
This database is the first of its kind on
fish-food data in the country and is envisaged
to serve as a repository of all
such nutritional information on different
food-fish species. This would also serve
as a knowledgebase for different clientele
groups, including physicians, nutritionists,
planners and consumers to
increase the utility of fish as a health
food and in clinical nutrition as well. The
nutritional information generated could
also be helpful in prioritization of fish
species for aquaculture depending upon
their associated nutritional values
Measurement of the ratio of branching fractions BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma)
The ratio of branching fractions of the radiative B decays B0 -> K*0 gamma
and Bs0 -> phi gamma has been measured using 0.37 fb-1 of pp collisions at a
centre of mass energy of sqrt(s) = 7 TeV, collected by the LHCb experiment. The
value obtained is BR(B0 -> K*0 gamma)/BR(Bs0 -> phi gamma) = 1.12 +/- 0.08
^{+0.06}_{-0.04} ^{+0.09}_{-0.08}, where the first uncertainty is statistical,
the second systematic and the third is associated to the ratio of fragmentation
fractions fs/fd. Using the world average for BR(B0 -> K*0 gamma) = (4.33 +/-
0.15) x 10^{-5}, the branching fraction BR(Bs0 -> phi gamma) is measured to be
(3.9 +/- 0.5) x 10^{-5}, which is the most precise measurement to date.Comment: 15 pages, 1 figure, 2 table
Measurement of the CKM angle γ from a combination of B±→Dh± analyses
A combination of three LHCb measurements of the CKM angle γ is presented. The decays B±→D K± and
B±→Dπ± are used, where D denotes an admixture of D0 and D0 mesons, decaying into K+K−, π+π−, K±π∓, K±π∓π±π∓, K0Sπ+π−, or K0S K+K− final states. All measurements use a dataset corresponding to 1.0 fb−1 of integrated luminosity. Combining results from B±→D K± decays alone a best-fit value of
γ =72.0◦ is found, and confidence intervals are set
γ ∈ [56.4,86.7]◦ at 68% CL,
γ ∈ [42.6,99.6]◦ at 95% CL.
The best-fit value of γ found from a combination of results from B±→Dπ± decays alone, is γ =18.9◦,
and the confidence intervals
γ ∈ [7.4,99.2]◦ ∪ [167.9,176.4]◦ at 68% CL
are set, without constraint at 95% CL. The combination of results from B± → D K± and B± → Dπ±
decays gives a best-fit value of γ =72.6◦ and the confidence intervals
γ ∈ [55.4,82.3]◦ at 68% CL,
γ ∈ [40.2,92.7]◦ at 95% CL
are set. All values are expressed modulo 180◦, and are obtained taking into account the effect of D0–D0
mixing
Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−
The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions
Search for CP violation in decays
A model-independent search for direct CP violation in the Cabibbo suppressed
decay in a sample of approximately 370,000 decays is
carried out. The data were collected by the LHCb experiment in 2010 and
correspond to an integrated luminosity of 35 pb. The normalized Dalitz
plot distributions for and are compared using four different
binning schemes that are sensitive to different manifestations of CP violation.
No evidence for CP asymmetry is found.Comment: 13 pages, 8 figures, submitted to Phys. Rev.
Measurement of the relative rate of prompt χc0, χc1 and χc2 production at √s=7TeV
Prompt production of charmonium χc0, χc1 and χc2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of √s=7TeV. The χc mesons are identified through their decay to J/ψγ, with J/ψ→μ+mu− using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χc1 and χc2 in the rapidity range 2.0<y<4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χc0 meson production at a hadron collider is also presented
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