Search results for "Lates"
showing 10 items of 738 documents
A novel and selective fluoride opening of aziridines by XtalFluor-E. synthesis of fluorinated diamino acid derivatives.
2015
The selective introduction of fluorine onto the skeleton of an aminocyclopentane or cyclohexane carboxylate has been developed through a novel and efficient fluoride opening of an activated aziridine ring with XtalFluor-E. The reaction proceeded through a stereoselective aziridination of the olefinic bond of a bicyclic lactam and regioselective aziridine ring opening with difluorosulfiliminium tetrafluoroborate with the neighboring group assistance of the sulfonamide moiety to yield fluorinated diamino acid derivatives. The method based on the selective aziridine opening by fluoride has been generalized to afford access to mono- or bicyclic fluorinated substances.
Iodine containing species in the remote marine boundary layer: A link to oceanic phytoplankton
2011
[1] Iodine containing species have been measured in the particle phase (PM2.5) and the gas phase during a ship campaign between January and February 2007 in the South Atlantic marine boundary layer (MBL). Methyl iodide (CH3I) in the gas phase and soluble iodine species, i.e. iodide, iodate and an unidentified organic iodine species (UOI), in PM2.5 were measured. Temporal variations of gaseous and particulate iodine species were investigated. The exposure of the sampled air masses to phytoplankton along the back-trajectories was studied using a lagrangian transport model and satellite observations of oceanic chlorophyll-a concentration. Significant correlations were found between the concent…
Thymine content of sea water as a measure of biosynthetic potential
1977
A hydrolysis procedure along with a high-pressure liquid chromatographic procedure is given enabling simple and reliable thymine determinations in the nanogram range in different fractions of sea-water samples taken from three different locations in the Northern Adriatic Sea. The levels corresponded to 1–3 μg DNA per liter. From total polyanionic thymine, which had been precipitated as the cetyltrimethylammonium salt, the highest percentage was linked to the particulate fraction, with a definite subsurface minimum at 10 to 15 m. There was a corresponding maximum of a high molecular “non-particulate” thymine-containing fraction at the corresponding depth. From the bottom at 30 m upwards to a…
Synthesis and thermal decomposition studies of homo- and heteroleptic tin(iv) thiolates and dithiocarbamates: molecular precursors for tin sulfides
2002
The syntheses and X-ray structures of novel heteroleptic thiolate/dithiocarbamate derivatives (Et2NCS2)2(RS)2Sn (R = Cy, CH2CF3) have been examined and their thermal decompositions compared with those of selected tin(II) and tin(IV) dithiocarbamates. The heteroleptic species decompose to SnS by initial elimination of RSSR to afford (Et2NCS2)2Sn and subsequent loss of [Et2NC(S)]2S. In contrast, (Et2NCS2)4Sn decomposes via [(Et2NCS2)2SnS]2, whose structure has been determined, and finally to SnS2 by sequential elimination of [Et2NC(S)]2S. The two families of compounds, (R2NCS2)4Sn and (Et2NCS2)2(RS)2Sn, thus provide single-source materials for bulk SnS2 and SnS, respectively, by virtue of the…
Postbuckling analysis of cracked stiffned plates by pb–2 Rayleigh-Ritz method
2015
A Rayleigh-Ritz approach for the analysis of buckling and post-buckling behavior of cracked composite stiffened plates is presented. The structure is thought as the assembly of plate elements modeled by the first order shear deformation theory. Continuity along the edges common to contiguous elements are enforced by using penalty techniques, which also allow to straightforwardly implement efficient crack modeling strategies. General symmetric and unsymmetric stacking sequences are considered and numerical procedures have been developed and used to validate the present solution by comparison with FEA results. Original results are also presented for post-buckling solution of multilayered stif…
Naphthalene-2,6-diyl bis(4-methylbenzenesulfonate)
2018
The complete molecule of the title compound, C24H20O6S2, is generated by a crystallographic inversion centre at the middle of the naphthalene ring system. The dihedral angle between the naphthalene ring system and the pendant benzene ring is 10.23 (6)° and the C—S—O—C torsion angle is −172.05 (10)°. In the crystal, weak C—H...O interactions link the molecules into (10-1) sheets.
4-Chloronaphthalen-1-yl 4-methylbenzenesulfonate
2018
In the title compound, C17H13ClO3S, the naphthalene ring system and the benzene ring of the tosylate substituent are inclined to one another by 55.32 (5)°. The crystal structure features weak intermolecular C—H...O hydrogen bonds, one of which forms inversion dimers. Additional C—H...O hydrogen bonds and weak Cl...Cl halogen bonds stack the molecules along the b-axis direction.
The influence of soft acidic drinks in exposing dentinal tubules after non-surgical periodontal treatment: a SEM investigation on the protective effe…
2007
Objective: The aim of this study was to investigate the different smear layer morphologies produced by instrumentation with a hand curette and a periodontal sonic scaler for potential removal by soft acidic solution. The effect of a new oxalate-containing phytocomplex spray in preventing tubules exposure after citric acid solution application was also evaluated. Methods: Thirty recently extracted human teeth were used to obtain root dentinal fragments and divided in two groups: Curette treatment (CRT) root planed applying 30 working strokes to each surface using a Gracey?s curette 5-6 and Ultrasonic scaler (USC) treated using a periodontal scaler mounted on an ultrasonic hand-piece for 30 s…
Genome-wide association study reveals new insights into the heritability and genetic correlates of developmental dyslexia
2021
Developmental dyslexia (DD) is a learning disorder affecting the ability to read, with a heritability of 40–60%. A notable part of this heritability remains unexplained, and large genetic studies are warranted to identify new susceptibility genes and clarify the genetic bases of dyslexia. We carried out a genome-wide association study (GWAS) on 2274 dyslexia cases and 6272 controls, testing associations at the single variant, gene, and pathway level, and estimating heritability using single-nucleotide polymorphism (SNP) data. We also calculated polygenic scores (PGSs) based on large-scale GWAS data for different neuropsychiatric disorders and cortical brain measures, educational attainment,…
Memory for time intervals is impaired in left hemi-Parkinson patients.
2004
The basal ganglia have been proposed as one of the neural correlates of timekeeping functions. Both encoding and memory retrieval components for time perception are impaired in Parkinson's disease (PD). The aim of our study was to investigate in hemi-Parkinsonian patients the existence of a specific alteration in memory for time depending on the affected side, to better understand the contribution of the left or right basal ganglia circuits in different components of time perception. Right and left hemi-PD patients performed a time reproduction task in which they were required to reproduce in the same session short (5 s) and long (15 s) time intervals, in off- and on-therapy condition. Whil…