Search results for "IOLs"
showing 10 items of 43 documents
Palladium-catalyzed heteroaryl thioethers synthesis overcoming palladium dithiolate resting states inertness: Practical road to sulfones and NH-sulfo…
2018
International audience; We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium-1,1'-bis [(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance. In the palladium catalyzed C-S coupling of heteroaromatic thiols, reactivity limitation is attached with electron-deficient thiols. We show that this limitation can be resolved by the successful use of 2-bromoheteroarenes in the C-S coupling. We established herein…
Dynamic Stabilization of the Ligand-Metal Interface in Atomically Precise Gold Nanoclusters Au68 and Au144 Protected by meta-Mercaptobenzoic Acid
2017
Ligand-stabilized, atomically precise gold nanoclusters with a metal core of a uniform size of just 1–3 nm constitute an interesting class of nanomaterials with versatile possibilities for applications due to their size-dependent properties and modifiable ligand layers. The key to extending the usability of the clusters in applications is to understand the chemical bonding in the ligand layer as a function of cluster size and ligand structure. Previously, it has been shown that monodispersed gold nanoclusters, stabilized by meta-mercaptobenzoic acid (m-MBA or 3-MBA) ligands and with sizes of 68–144 gold atoms, show ambient stability. Here we show that a combination of nuclear magnetic reson…
Studies on the Stereoselective Selenolactonization, Hydroxy and Methoxy Selenenylation of α- and β-Hydroxy Acids and Esters. Synthesis of δ- and γ-La…
2003
Abstract The diastereoselective synthesis of hydroxy substituted γ- and δ-lactones was accomplished following two approaches. A 5- or 6-endo cyclization promoted by electrophilic selenium reagents of α- or β-hydroxy acids and a 5- or 6-exo cyclization of hydroxy esters obtained through a diastereoselective hydroxy selenenylation reaction of α- or β-hydroxy esters. Moreover, the diastereoselective methoxy selenenylation of the above compounds was investigated showing a case in which the compound that was unreactive in the hydroxy selenenylation conditions gave, in the methoxy selenenylation conditions, the deprotected diol. The usefulness of the methoxy selenenylation procedure was proven by…
Presbiopijas korekcija ar multifokālajām intraokulārajām lēcām
2017
Bakalaura darbs ir uzrakstīts angļu valodā uz 47 lapaspusēm. Tas satur 3 zīmējumus, 20 tabulas, 39 literatūras avotus un pielikumu. Darba mērķis ir salīdzināt divu jaunu intraokulāro lēcu (difraktīvā trifokālā lēca un paplašināta fokusa dziļuma multifokālā lēca) efektivitāti presbiopija korekcijā pēc kataraktas operācijas. Pētījumi tika veikti 3 mēnešu periodā pēc kataraktas operācijas, kad tika novērtēta redzes kvalitāte, mērot redzes asumu un kontrasta redzi fotopiskos gaismas un mezopiskos krēslas apstākļos. Abi introokulāro lēcu veidi nodrošināja lielisku redzes asumu visos skata attālumos un pilnu neatkarību no brillēm. Taču kontrasta jūtība un redzes asums mezopiskos krēslas apstākļos…
What Contributes to the Measured Chiral Optical Response of the Glutathione-Protected Au25 Nanocluster?
2023
The water-soluble glutathione-protected [Au25(GSH)18]−1 nanocluster was investigated by integrating several methodologies such as molecular dynamics simulations, essential dynamics analysis, and state-of-the-art time-dependent density functional theory calculations. Fundamental aspects such as conformational, weak interactions and solvent effects, especially hydrogen-bonds, were included and found to play a fundamental role in assessing the optical response of this system. Our analysis demonstrated not only that the electronic circular dichroism is extremely sensitive to the solvent presence but also that the solvent itself plays an active role in the optical activity of such system, formin…
Multifokale Intraokularlinsen
2001
Modern cataract surgery has developed tremendously during the past 10-15 years. Improved surgical techniques, as well as improved implant materials and designs, have enlarged patient profiles and indications for cataract surgery. This also created much higher expectations from the patients' site. The loss of accommodation is loss of quality of life for presbyopic and especially young pseudophakic patients. Therefore cataract surgery with multifocal IOL implantation is not only of academic interest, but reflects demands and expectations of our patients. Multifocal IOLs have been implanted since 1986, starting with 2-3 zone refractive and diffractive designs. Due to surgical techniques of tha…
Latvijā legālie kaņepju preparāti un to izmantošana Latvijas iedzīvotāju vidū
2022
Kaņepju preparāti ir gan vēsturiski, gan mūsdienās aktuāls līdzeklis, ko izmanto gan skaistumkopšanā, gan medicīniskiem nolūkiem, gan arī uzturā. Tie kļuvuši īpaši populāri kā uztura bagātinātāji ikdienas dzīvēs cilvēkiem, lai uzlabotu dzīves kvalitāti, papildinot uzturu ar vērtīgajām vielām, ko satur kaņepes. Kanabinoīdi no kaņepju auga uz organismu iedarbojas caur endokanabinoīdu sistēmu. Pētījuma mērķis ir apkopot datus par Latvijas iedzīvotāju informētību par legālajiem kaņepju preparātiem un par parametriem, kas saistīti ar šo preparātu lietošanu. Rezultāti liecina, ka arī starp Latvijas iedzīvotajiem kaņepju preparāti ir zināmi un tiek izmantoti dažādiem potenciāliem ieguvumiem, kurie…
Kaņepju auga iegūšanas, izplatīšanas, izmantošanas uzturā un medicīniskiem nolūkiem - tiesiskais regulējums Eiropas Savienībā, starptautiskajās tiesī…
2020
Kaņepju augu šķiedra, sēklas, ziedi un lapas jau tūkstošiem gadu ir tikušas izmantotas gan dažādu sadzīves, gan pārtikas produktu pagatavošanai, kā arī medicīniskiem un atpūtas nolūkiem, tomēr daudzu politisku iemeslu dēļ 20.gs vidū daudzviet pasaulē šī auga izmantošana tika aizliegta, jo kaņepju sastāvā tika atklāta viela tetrahidrokanabinols, kas ir psihoaktīva un atkarību izraisoša viela. Turklāt 20.gs. 60.gados kaņepju izmantošanas aizliegumu sāka noteikt starptautiskā līmenī, tomēr vēlāk kaņepes atļāva audzēt šķiedras un sēklu ieguvei, kā arī dārzkopības mērķiem. Neraugoties uz pastāvošajiem ierobežojumiem, interese par kaņepju augiem sabiedrībā nav zudusi, tieši pretēji – palielinājus…
Dynamic Stabilization of the Ligand-Metal Interface in Atomically Precise Gold Nanoclusters Au68 and Au144 Protected by meta-Mercaptobenzoic Acid
2017
Ligand-stabilized, atomically precise gold nanoclusters with a metal core of a uniform size of just 1-3 nm constitute an interesting class of nanomaterials with versatile possibilities for applications due to their size-dependent properties and modifiable ligand layers. The key to extending the usability of the clusters in applications is to understand the chemical bonding in the ligand layer as a function of cluster size and ligand structure. Previously, it has been shown that monodispersed gold nanoclusters, stabilized by meta-mercaptobenzoic acid (m-MBA or 3-MBA) ligands and with sizes of 68-144 gold atoms, show ambient stability. Here we show that a combination of nuclear magnetic reson…
Evolving European guidance on the medical management of neovascular age related macular degeneration
2006
BACKGROUND: Until recently, only two options were available for the treatment of choroidal neovascularisation (CNV) associated with age related macular degeneration (AMD)-thermal laser photocoagulation and photodynamic therapy with verteporfin (PDT-V). However, new treatments for CNV are in development, and data from phase III clinical trials of some of these pharmacological interventions are now available. In light of these new data, expert guidance is required to enable retina specialists with expertise in the management of AMD to select and use the most appropriate therapies for the treatment of neovascular AMD. METHODS: Consensus from a round table of European retina specialists was obt…