Search results for "Gate"
showing 10 items of 1811 documents
New complex polycyclic compounds: Synthesis, antiproliferative activity and mechanism of action
2020
Abstract Polycyclic or O-glycoconiugate polycyclic compounds 1a-g were previously tested for their in vitro antiproliferative activity. In this series of compounds, activity increases as log P decreases. Specifically, compounds 1d and 1g showed lower log P values together with the best antiproliferative profiles. With the aim of extending our understanding of the structure–activity relationship (SAR) of this class of compounds, we prepared new polycyclic derivatives 2a-c, which bear on each of the two phenyl rings hydrophilic substituents (OH, SO2NH2 or NHCOCH3). These substituents are able to form hydrogen bonds and to decrease the partition coefficient value as compared with compound 1d. …
Overcoming Steric Hindrance in Aryl‐Aryl Homocoupling via On‐Surface Copolymerization
2019
On-surface synthesis is a unique tool for growing low-dimensional carbon nanomaterials with precise structural control down to the atomic level. This novel approach relies on carefully designed precursor molecules, which are deposited on suitable substrates and activated to ultimately form the desired nanostructures. One of the most applied reactions to covalently interlink molecular precursors is dehalogenative aryl-aryl coupling. Despite the versatility of this approach, many unsuccessful attempts are also known, most of them associated to the poor capability of the activated precursors to couple to each other. Such failure is often related to the steric hindrance between reactants, which…
Solid State Luminescence Enhancement in π-Conjugated Materials: Unraveling the Mechanism beyond the Framework of AIE/AIEE
2017
Solid state luminescence enhancement (SLE) of conjugated organic materials has had a great impact in materials science, but a deep understanding has been rather limited to date. Here, we investigate a prototype example of SLE materials, cyano-substituted distyrylbenzene (DCS), by varying systematically and subtly the substitution pattern (inter alia of the position of the cyano-substituent) to give largely different photoresponse in fluid and solid solution as well in the crystalline state. The combination of quantitative (ultra)fast optical spectroscopic techniques, appropriate quantum-chemical methods, and structural (X-ray) data allows us to elucidate and rationalize all details of the S…
Highly Conjugatedp-Quinonoidπ-Extended Tetrathiafulvalene Derivatives: A Class of Highly Distorted Electron Donors
2004
A new class of pi-extended TTF-type electron donors (11 a-c) has been synthesized by Wittig-Horner olefination of bianthrone (9) with 1,3-dithiole phosphonate esters (10 a-c). In cyclic voltammetry experiments, donors 11 a-c reveal a single, electrochemically irreversible oxidation-yielding the corresponding dicationic products-at relatively low oxidation potentials (approximately 0.7-0.8 V). Theoretical calculations, performed at the DFT level (B3 P86/6-31 G*), predict a highly-folded C(2h) structure for 11 a. In the ground state, the molecule adopts a double saddle-like conformation to compensate the steric hindrance. The calculations suggest that the intramolecular charge transfer associ…
ChemInform Abstract: nBuLi-Mediated Hydrophosphination: A Simple Route to Valuable Organophosphorus Compounds.
2010
A straightforward synthesis of homoallyl- and allylphosphanes has been developed using nBuLi-mediated hydrophosphination of conjugated dienes. In all the cases the phosphorus atom of the reacting phosphane attacked the sterically less demanding side of the diene exclusively. In addition, high regioselectivities towards 1,2- or 1,4-addition products were observed depending on the nature of the dienes. This hydrophosphination reaction was extended to a variety of substrates such as styrene derivatives, alkynes and 1,3,5-cycloheptatriene. The structures of three hydrophosphination products were confirmed by X-ray diffraction studies.
nBuLi-Mediated hydrophosphination: a simple route to valuable organophosphorus compounds
2010
A straightforward synthesis of homoallyl- and allylphosphanes has been developed using nBuLi-mediated hydrophosphination of conjugated dienes. In all the cases the phosphorus atom of the reacting phosphane attacked the sterically less demanding side of the diene exclusively. In addition, high regioselectivities towards 1,2- or 1,4-addition products were observed depending on the nature of the dienes. This hydrophosphination reaction was extended to a variety of substrates such as styrene derivatives, alkynes and 1,3,5-cycloheptatriene. The structures of three hydrophosphination products were confirmed by X-ray diffraction studies.
Integrating Experiences: Palermo Mediterranean Gateway City. Identity and Innovation
2019
Metropolitan transformations of the Palermo as a Mediterranean city, guided by envisioning it as a ‘fluid’ gateway city, have been seen as an example for the planning of other such cities in Italy and Europe. The 2025 strategic vision for Palermo was inspired by three key components: (i) the relevance of Palermo as ‘hub territory’ in European level concerns in territorial and infrastructure development policies; (ii) the urban and regional experience with the concept ‘fluid city’ (envisioning the city as a portal and place of interaction and exchanges, not just in terms of goods and people); and (iii) new metropolitan vision produced by new regional and national legislation on metropolitan …
Study of the role of “gatekeeper” mutations V654A and T670I of c-kit kinase in the interaction with inhibitors by means mixed molecular dynamics/dock…
2011
The over-expression of c-kit proto-oncogene has been reported in hematopoietic cells, small cell lung cancer, and gastrointestinal stromal tumors. The clinical importance of c-kit expression in tumors focused the research towards inhibitors of this tyrosine kinase. Imatinib (Gleevec®) was the first compound used in therapy, but mutations on c-kit led to reduced effectiveness or ineffectiveness of this treatment. Other compounds are likely to be effective against mutants, such as Sunitinib (Sutent®), but the need for new and most effective inhibitors against mutants is still critical. We report mixed Molecular Dynamics/Docking study with the aim to unveil the molecular mechanism involved in …
A software tool via web for the statistical data analysis; R-php
2007
The spread of Internet and the growing demand of services from the web users have changed and are still changing the way to organize the work or the study. Nowadays, the main part of information and many services are on the web and the software is going toward the same direction: in fact, the use of software implemented via web is ever-increasing, with a client-server logic that enables the “centralized” use of software installed on a server. In this paper we describe the Structure and the running of R-php, an environment for statistical analysis, freely accessible and attainable through the World Wide Web, based on the statistical environment R. R-php is based on two modules: a base module…
Nörttikulttuurin identiteettikriisi
2020
Nörttikulttuuri on identiteettikriisissä. Perinteisesti nörttimäisinä pidetyt käytänteet ja kulttuurituotteet ovat siirtyneet lähemmäs valtavirtaa, mikä on häivyttänyt rajaa nörttien ja muiden median ja teknologian käyttäjien välillä. Nörttikulttuurin sisälle tämä on heijastunut kiistaksi siitä, kuka saa osallistua nörttikulttuurin kuluttamiseen, tuottamiseen ja määrittelyyn, ja millä tavoin. Stereotypia nörttikulttuurista valkoisten heteromiesten maskuliinisena kenttänä ei koskaan ole pitänyt täysin paikkansa, mutta 2000-luvulla väitteen totuudellisuus on murentunut entisestään.
 Tässä artikkelissa tarkastelemme nörttiyden kriisiä kolmen tapaustutkimuksen kautta ja analysoimme, mitä G…