Search results for "Cone"
showing 10 items of 772 documents
(E)-1-(1,3-Benzodioxol-5-yl)-3-(2,4,5-trimethoxyphenyl)prop-2-en-1-one
2017
The molecule of the title compound C19H18O6, adopts anEconformation about the C=C double bond and the C—C=C—C torsion angle is −179.30 (16)°. The molecule is nearly planar, as indicated by the dihedral angle of 6.99 (6)° between the benzene ring and the benzodioxalane ring. In the crystal, molecules are linkedviaweak C—H...O hydrogen bonds, forming zigzag chains propagating along thebaxis.
The structure and stereochemistry of atractyligenin
1966
Abstract The structure of atractyligenin C19H28O4, the nor-diterpenoidic aglycone of atractyloside C30H44O16S2K2 has been substantiated as Ia. The absolute configuration shown in Ia proves it to be a derivative of (−)kaurene.
Synthesis of pyrido[2,3-d]pyrimidines in the reaction of 6-amino-2,3-dihydro-2-thioxo-4(1H)-pyrimidinone with chalcones
1992
6-Amino-2,3-dihydro-2-thioxo-4(1H)-pyrimidinone (1) reacts in boiling DMF with α,/β-unsaturated ketones 2 yielding the pyrido[2,3-d]pyrimidine systems 5 and 6, respectively. The orientation in the addition process can be determined by nmr measurements, especially by NOE difference spectroscopy. The products do not correspond to a normal Skraup or Doebner-v. Miller synthesis.
Konvergenz von Absorption und Fluoreszenz bei gekreuzt konjugierten Oligomeren aus Chalkon-Bausteinen
1999
The absorption and fluorescence spectra of two series of chalcone oligomers (1a–d) and (2a–d) are reported. Due to small or vanishing orbital coefficients (HMO calculation) within the cross-conjugated systems, the bathochromic shifts caused by the extension of the chains are modest. The effective conjugation lengths amount to 6 and 14 chalcone building blocks in the absorptions of the series 1 and 2. The convergence of the fluorescence bands is already reached in 1d and 2d with 4 and 8 enone units, respectively. Besides the uniform or alternate arrangement of the chalcone building blocks, the positions of the propoxy substituents show a considerable influence on the electronic transitions p…
The chemical composition of essential oil from Seseli bocconei (Apiaceae) aerial parts growing in Sicily (Italy)
2022
Seseli is a large genus of aromatic and economically important herbs of the Apiaceae family that includes eighty-seven taxa, mainly distributed in Europe and Asia. Several species of this genus are extensively used in various popular medicines and based on their traditional uses, much research concerning biological activities have been carried out. In the present study, the chemical composition of the essential oil from aerial parts of Seseli bocconei Guss., a rare plant endemic of Sicily, was analysed by GC-MS. No one report has been previously published on the essential oil of this species. The result showed the presence of large quantity of monoterpene and sesquiterpene hydrocarbons wher…
PCARE and WASF3 regulate ciliary F-actin assembly that is required for the initiation of photoreceptor outer segment disk formation
2020
Significance The photoreceptor outer segments are primary cilia, modified for phototransduction by incorporation of stacked opsin-loaded membrane disks that are continuously regenerated. This process is disrupted in several types of inherited retinal dystrophy, but the driving force remained unclear. We show that C2orf71/PCARE (photoreceptor cilium actin regulator), associated with inherited retinal dystrophy subtype RP54, efficiently recruits the Arp2/3 complex activator WASF3 to the cilium. This activates an actin dynamics-driven expansion of the ciliary tip, resembling membrane evagination in lamellipodia formation. Colocalization of this actin dynamics module to the base of the outer se…
Impact of the knowledge society in the university and in scientific communication
2014
Over the last two decades, as a result of the introduction and intensive use of technologies for information and general knowledge, especially from the internet, the university is living in a process of complete transformation that affects it´s academic and organizational structures as well as the conception of educational methodology. The ICTs have demonstrated a need to establish coherent institutional strategies in their use and application, along with the possibility to expand the sphere of institutional action, in regards to general access to higher education. All of this shows an existing change from a model of education based on the transmission of knowledge, that was rather limited …
Third molar surgical difficulty scales: systematic review and preoperative assessment form
2021
Background The main objective of this systematic review was to collect the pre-existing scales for assessing the difficulty of third molar extraction. The secondary objective was to design a proposal for a preoperative evaluation protocol for the difficulty of third molar extraction. Material and Methods Two independent researchers conducted an electronic search in Pubmed (MEDLINE), Cochrane, and Scopus databases during March 2021. Included studies evaluated the prediction of the difficulty of surgical removal of impacted upper or lower third molars using new indices/scales or pre-existing scales with or without modifications. Articles referring to coronectomies or assessing pre-surgical di…
Estudio de los conectores contraargumentativos en las definiciones lexicográficas
2018
El tema que nos ocupa trata fundamentalmente de los marcadores del discurso, y, en particular, de los conectores contraargumentativos; los cuales transmiten un significado de de contraste u oposición. Actuación que nos fijamos llevar a cabo En el presente trabajo, nos hemos propuesto como cometido abordar el tratamiento de los marcadores del discurso (desde ahora, abreviaremos este término con la sigla MD) en la lexicografía monolingüe / unilingüe francesa y española. En la búsqueda de nuestro corpus, nos hemos ceñido al ámbito lexicográfico de los diccionarios descriptivos o también llamados de uso de la lengua. Hemos centrado, pues, nuestra atención, en aquellos diccionarios que fueran de…
Pasaulē lielākā koka čiekuri Latvijas Universitātes Muzejā
2019
LU Muzeja Botānikas un mikoloģijas kolekcijas dāvinājumā no valodnieces Ievas Auziņas Szentivanyi saņēmušas 5 milzu mamutkoka (Sequoiadendron giganteum (Lindl.) J.Buchh.) čiekurus, 3 no kuriem savākti šīs sugas pārstāvja, pašlaik pasaulē lielākā koka pēc koksnes apjoma, Ģenerāļa Šermana (General Sherman), pakājē.