1,977 research outputs found
Syntheses of spiro[cyclopropane-1,3\u27-oxindole]-2-carboxylic acid and cyclopropa[c]quinoline-7b-carboxylic acid and their derivatives
The synthesis of spiro[cyclopropane-1,3′-oxindole]-2-carboxylic acid, including novel 3-(2- and 3-pyridyl)-substituted analogues and the novel cyclopropa[c]quinoline-7b-carboxylic acid and their ester and amide derivatives is described. These syntheses involve diastereoselective cyclopropanation reactions of methyl 2-(2-nitrophenyl)acrylate and (3E)-(pyridin-2-ylmethylene)- and (3E)-(pyridin-3-ylmethylene)-1,3-dihydro-2H-indol-2-one with ethyl (dimethyl sulfuranylidene) acetate (EDSA). The synthesis of methyl cyclopropa[c]quinoline-7b-carboxylate involves a regioselective reductive cyclization of a nitro-diester precursor. The relative stereochemistry of key compounds has been determined by single-crystal X-ray structural analysis
Synthesis of (+/-)epipentenomycin I and III
A synthesis of (±) epipentenomycin I and III is reported from a regioselective epoxidation of racemic 3-hydroxy- and 3-acetoxy-2-methylene-4-cyclopentenone, respectively, with dimethyldioxirane followed by hydrolytic ring-opening of the resulting epoxide
Longitudinal evaluation of cognitive functioning in young children with type 1 diabetes over 18 months
OBJECTIVE: Decrements in cognitive function may already be evident in young children with type 1 diabetes (T1D). Here we report prospectively acquired cognitive results over 18 months in a large cohort of young children with and without T1D. METHODS: 144 children with T1D (mean HbA1c: 7.9%) and 70 age-matched healthy controls (mean age both groups 8.5 years; median diabetes duration 3.9 yrs; mean age of onset 4.1 yrs) underwent neuropsychological testing at baseline and after 18-months of follow-up. We hypothesized that group differences observed at baseline would be more pronounced after 18 months, particularly in those T1D patients with greatest exposure to glycemic extremes. RESULTS: Cognitive domain scores did not differ between groups at the 18 month testing session and did not change differently between groups over the follow-up period. However, within the T1D group, a history of diabetic ketoacidosis (DKA) was correlated with lower Verbal IQ and greater hyperglycemia exposure (HbA1c area under the curve) was inversely correlated to executive functions test performance. In addition, those with a history of both types of exposure performed most poorly on measures of executive function. CONCLUSIONS: The subtle cognitive differences between T1D children and nondiabetic controls observed at baseline were not observed 18 months later. Within the T1D group, as at baseline, relationships between cognition (VIQ and executive functions) and glycemic variables (chronic hyperglycemia and DKA history) were evident. Continued longitudinal study of this T1D cohort and their carefully matched healthy comparison group is planned
Coordinative flexibility of 1,2-bis[1,4,7-triazacyclonon-1-yl]propan-2-ol in mononuclear and binuclear Ni(II) complexes
Ilmu Kimia Tanaman Lauraceae Indonesia: VI. Kriptokaryon dari Cryptocarya Laevigata BL. (Lauraceae)
Ekstraksi kulit akar dan kulit barang tanaman Cryptocarya laevigata Bl. (Lauraceae) dengan n-heksan menghasilkan suatu calkon yang diidentifikasi sebagai kriptokaryon (I). Struktur senyawa ini ditetapkan berdasarkan data spektroskopi dan analisis Kristal sinar-X. Kesimpulan mengenai struktur kriptokaryon (I) mendukung saran peneliti sebelumnya, yang terlah merevisi struktur (II) yang pertama kali disarankan. C. laevigata adalah spesies kedua anggota suku Lauraceae yang telah ditemukan mengandung kriptokaryon (I). Tambahan pula, kriptokaryon (I) adalah senyawa alam kedua dari jenis flavonoid yang mengandung cincin A yang tereduksi sebagian, yang pernah ditemukan. Extraction of the root and the tree barks of Cryptocarya laevigata Bl. (Lauraceae) with n-hexane yielded a chalcone identified as cryptocaryone (I). The structure of this compound had been elucidated based on spectroscopic measurements and X-ray crystal analysis. Conclusions about the structure of cryprocaryone (I) confirm the previous suggestion, which revised the structure (ll) suggested earlier. C. laevigata is the second species of Lauraceae which contains cryptocaryone (I). Furthermore, cryptocaryone (I) is a second naturally occurring flavonoid containing a reduced A ring system which has so far been isolated
The effect of alkyl chain length in a series of novel N-alkyl-3-benzylimidazolium iodide salts
Publishing and sharing multi-dimensional image data with OMERO
Imaging data are used in the life and biomedical sciences to measure the molecular and structural composition and dynamics of cells, tissues, and organisms. Datasets range in size from megabytes to terabytes and usually contain a combination of binary pixel data and metadata that describe the acquisition process and any derived results. The OMERO image data management platform allows users to securely share image datasets according to specific permissions levels: data can be held privately, shared with a set of colleagues, or made available via a public URL. Users control access by assigning data to specific Groups with defined membership and access rights. OMERO’s Permission system supports simple data sharing in a lab, collaborative data analysis, and even teaching environments. OMERO software is open source and released by the OME Consortium at www.openmicroscopy.org
The first GCT camera for the Cherenkov Telescope Array
The Gamma Cherenkov Telescope (GCT) is proposed to be part of the Small Size
Telescope (SST) array of the Cherenkov Telescope Array (CTA). The GCT
dual-mirror optical design allows the use of a compact camera of diameter
roughly 0.4 m. The curved focal plane is equipped with 2048 pixels of
~0.2{\deg} angular size, resulting in a field of view of ~9{\deg}. The GCT
camera is designed to record the flashes of Cherenkov light from
electromagnetic cascades, which last only a few tens of nanoseconds. Modules
based on custom ASICs provide the required fast electronics, facilitating
sampling and digitisation as well as first level of triggering. The first GCT
camera prototype is currently being commissioned in the UK. On-telescope tests
are planned later this year. Here we give a detailed description of the camera
prototype and present recent progress with testing and commissioning.Comment: In Proceedings of the 34th International Cosmic Ray Conference
(ICRC2015), The Hague, The Netherlands. All CTA contributions at
arXiv:1508.0589
Chemistry of o-Xylidene-Metal Complexes. Part 3.' Tungsten o-Xylidene Complexes derived from Tetrachloro(oxo)tungsten(vl) ; X-Ray Crystal Structures of [~( C H 2 C 6 H 4~H z -o )~]~~.~~~~6 and [{~(CH2C,H4CH2=~)20}2~g(C4H*0)41*
Reaction of WCI4O with the di-Grignard reagent O-C&(CH2MgC1)2 or the chloride-free ' o-xylidene ' complex Mg(CH2C6H4CH2-o) (thf) in tetrahydrofuran (thf) yields either the thermally stable tris(chelate), [We use the umbrella term ' o-xylidenemetal complex ' to describe, without prejudice as to bonding, all O-C~I&(CH~)~-metal complexes in which the organic ligand binds in (a) a bridging mode, as i
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