Search results for "lek"

Plasmonic Resonant Nanoantennas Induce Changes in the Shape and the Intensity of Infrared Spectra of Phospholipids.

2021

Surface enhanced infrared absorption spectroscopic studies (SEIRAS) as a technique to study biological molecules in extremely low concentrations is greatly evolving. In order to use the technique for identification of the structure and interactions of such biological molecules, it is necessary to identify the effects of the plasmonic electric-field enhancement on the spectral signature. In this study the spectral properties of 1,2-Dipalmitoyl-sn-glycero-3 phosphothioethanol (DPPTE) phospholipid immobilized on gold nanoantennas, specifically designed to enhance the vibrational fingerprints of lipid molecules were studied. An AFM study demonstrates an organization of the DPPTE phospholipid in…

Īss ievads komplekso savienojumu teorijā

1935

Īsais ievads komplekso savienojumu teorijā ir izvilkums no speciāla papildus kursa neorganiskajā ķīmijā.

Halogen-bonded solvates of tetrahaloethynyl cavitands

2017

The formation and structures of halogen-bonded solvates of three different tetrahaloethynyl cavitands with acetone, chloroform, acetonitrile, DMF and DMSO were prepared and investigated. The inclusion and host–guest behaviour of the resorcinarene cavitands was found to be highly dependent on the flexibility of the ethylene-bridging unit.

Suomalaisen perheen yhteisen sukunimen lyhyt historia

2016

Viimeistään 1900-luvulta lähtien on ajateltu, että yhteinen sukunimi symboloi suomalaista perhettä julkisissa yhteyksissä ja muodostaa perheenjäsenten yhteisen identiteetin perustekijän. Suomen lainsäädännön mukaan naiset olivat kuitenkin velvollisia ottamaan aviomiehensä sukunimen vain lyhyen aikaa, 1930-luvulta 1980-luvulle ulottuvalla ajanjaksolla. Pohdin artikkelissani, miksi 1800-luvun lopun ja 1900-luvun alkuvuosikymmenten ajatusmaailma vaikutti hyvin pitkään suomalaisten sukunimistöön. peerReviewed

Analytical-numerical methods for finding hidden oscillations in dynamical systems

2012

Metodika un aparatūra 14C aktivitātes noteikšanai mazaktīvos paraugos

1999

Darbu kopsavilkums fizikas doktora grāda iegūšanai

Актуальные проблемы физики и химии сегнетоэлектриков

1987

Объектом исследований являются монокристаллические и поликристаллические сегнетоэлектрики. Изучение свойств одного из основных классов сегнетоэлектриков дает ценную информацию как для фундаментальной науки, так и для решения ряда прикладных задач, например, по созданию элементов для электрооптики и нелинейной оптики пиродетекторов и электромеханических преобразователей.

Supramolecular Chirogenesis in Bis-Porphyrin: Crystallographic Structure and CD Spectra for a Complex with a Chiral Guanidine Derivative

2021

The complexation of (3aR,7aR)-N-(3,5-bis(trifluoromethyl)phenyl)octahydro-2H-benzo[d]imidazol-2-imine (BTI), as a guest, to ethane-bridged bis(zinc octaethylporphyrin), bis(ZnOEP), as a host, has been studied by means of ultraviolet-visible (UV-Vis) and circular dichroism (CD) absorption spectroscopies, single crystal X-ray diffraction, and computational simulation. The formation of 1:2 host-guest complex was established by X-ray diffraction and UV-Vis titration studies. Two guest BTI molecules are located at the opposite sides of two porphyrin subunits of bis(ZnOEP) host, which is resting in the anti-conformation. The complexation of BTI molecules proceed via coordination of the imine nitr…

Subcomponent self‐assembly of a cyclic tetranuclear Fe(II) helicate in a highly diastereoselective self‐sorting manner

2019

Abstract An enantiomerically pure diamine based on the 4,15‐difunctionalized [2.2]paracyclophane scaffold and 2‐formylpyridine self‐assemble into an optically pure cyclic metallosupramolecular Fe4L6 helicate upon mixing with iron(II) ions in a diastereoselective subcomponent self‐assembly process. The cyclic assembly results from steric strain that prevents the formation of a smaller linear dinuclear triple‐stranded helicate, and hence, leads to the larger strain‐free assembly that fulfils the maximum occupancy rule. Interestingly, use of the racemic diamine also leads to a racemic mixture of the homochiral cyclic helicates as the major product in a highly diastereoselective narcissistic ch…

Thiourea Organocatalysts as Emerging Chiral Pollutants: En Route to Porphyrin-Based (Chir)Optical Sensing

2021

Environmental pollution with chiral organic compounds is an emerging problem requiring innovative sensing methods. Amino-functionalized thioureas, such as 2-(dimethylamino)cyclohexyl-(3,5-bis(trifluoromethyl)phenyl)thiourea (Takemoto’s catalyst), are widely used organocatalysts with virtually unknown environmental safety data. Ecotoxicity studies based on the Vibrio fischeri luminescence inhibition test reveal significant toxicity of Takemoto’s catalyst (EC50 = 7.9 mg/L) and its NH2-substituted analog (EC50 = 7.2–7.4 mg/L). The observed toxic effect was pronounced by the influence of the trifluoromethyl moiety. En route to the porphyrin-based chemosensing of Takemoto-type thioureas, their s…