Search results for "lek"
showing 10 items of 2808 documents
Effects of activated carbon ageing in three PCB contaminated sediments: Sorption efficiency and secondary effects on Lumbriculus variegatus.
2015
The sorption efficiency and possible secondary effects of activated carbon (AC) (o 63-200 μm) was studied with Lumbriculus variegatus in three PCB contaminated sediments applying long AC-sediment contact time (3 years). AC amendment efficiently reduced PCB bioavailability as determined with both, L. variegatus bioaccumulation test and passive samplers. However, dose related secondary effects of AC on egestion rate and biomass were observed (applied doses 0.25% and 2.5% sediment dry weight). The sorption capacity and secondary effects remained similar when the experiments were repeated after three years of AC-sediment contact time. Further, transmission electron microscopy (TEM) samples reve…
Katjona-pī mijiedarbību ietekme uz luminoforu optiskajām īpašībām
2020
Literatūras apskatā aplūkota luminiscence, enerģijas pārnese, agregācijas izraisītās dzēšanas (ACQ) un agregācijas inducētās emisijas (AIE) luminiscenci ietekmējošie efekti. Iekļauti ACQ un AIE luminoforu piemēri un emisijas mehānismi. Rezultātu izvērtējumā aplūkotas veiktās sintēzes, analizētas iegūto savienojumu optiskās īpašības, iegūtās rentgenstruktūras un savienojumu optimizēto ģeometriju rezultāti. Darba eksperimentālajā daļā sintezēti 28 savienojumi. 3 no tiem ir benziltipa katjonās daļas saturoši savienojumi, 6 – piridīna atvasinājumi un 17 – piridīnija atvasinājumi, bet 2 ir starpprodukti. Aprakstītas sintēžu metodes, iekļauti vielu raksturojumi, izmantojot 1H–KMR, 13C–KMR, IS un …
Chest electrical impedance tomography examination, data analysis, terminology, clinical use and recommendations: consensus statement of the translati…
2017
Electrical impedance tomography (EIT) has undergone 30 years of development. Functional chest examinations with this technology are considered clinically relevant, especially for monitoring regional lung ventilation in mechanically ventilated patients and for regional pulmonary function testing in patients with chronic lung diseases. As EIT becomes an established medical technology, it requires consensus examination, nomenclature, data analysis and interpretation schemes. Such consensus is needed to compare, understand and reproduce study findings from and among different research groups, to enable large clinical trials and, ultimately, routine clinical use. Recommendations of how EIT findi…
Sprediķi no J. Lautenbacha
1902
Manuskripts rokrakstā.
Jurista Dītriha Andreja Lēbera personālais fonds Latvijas Akadēmiskajā bibliotēkā
2004
Di- and Tetrairon(III) μ-Oxido Complexes of an N3S-Donor Ligand: Catalyst Precursors for Alkene Oxidations
2019
The new di- and tetranuclear Fe(III) μ-oxido complexes [Fe 4 (μ-O) 4 (PTEBIA) 4 ](CF 3 SO 3 ) 4 (CH 3 CN) 2 ] (1a), [Fe 2 (μ-O)Cl 2 (PTEBIA) 2 ](CF 3 SO 3 ) 2 (1b), and [Fe 2 (μ-O)(HCOO) 2 (PTEBIA) 2 ](ClO 4 ) 2 (MeOH) (2) were prepared from the sulfur-containing ligand (2-((2,4-dimethylphenyl)thio)-N,N-bis ((1-methyl-benzimidazol-2-yl)methyl)ethanamine (PTEBIA). The tetrairon complex 1a features four μ-oxido bridges, while in dinuclear 1b, the sulfur moiety of the ligand occupies one of the six coordination sites of each Fe(III) ion with a long Fe-S distance of 2.814(6) A. In 2, two Fe(III) centers are bridged by one oxido and two formate units, the latter likely formed by methanol oxidati…
Behavioral and Brain Measures of Morphological Processing in Children With and Without Familial Risk for Dyslexia From Pre-school to First Grade
2021
School-age reading skills are associated with and predicted by preschool-age cognitive risk factors for dyslexia, such as deficits in phonological awareness, rapid automatized naming, letter knowledge, and verbal short-term memory. In addition, evidence exists that problems in morphological information processing could be considered a risk factor for dyslexia. In the present study, 27 children at pre-school age and the same 27 children at first grade age performed a morphological awareness task while their brain responses were measured with magnetoencephalography. Our aim was to examine how derivational morphology in Finnish language, and concomitant accuracy and reaction times are associat…
Meliorācijas ietekme uz Vesetnieku ekoloģiskā stacionāra kūdras augsnes ķīmisko sastāvu
2015
Darbā pētīti nosusinātā un nenosusinātā pārejas tipa purva augsnes paraugi, sadarbībā ar Latvijas Valsts mežzinātnes institūta „Silava” pētniekiem. Darba ietvaros ķīmiskajām analīzēm kūdras paraugi ņemti no 6 parauglaukumiem, no noteiktiem augsnes dziļumiem (O horizonts, 0-10 cm, 10-20 cm, 20-40 cm, 40-80 cm, kopā 26 paraugi). Augsnes paraugiem noteikta oglekļa un slāpekļa stabilo izotopu attiecība, 1 M HNO3 ekstrahējamo Fe, Zn, Cu, Mn, K, Pb, Cr, Cd un Ni saturs, augsnes pH un homogenitāte. Noteikta elementu analizatora izotopu attiecības masspektrometra mērījumu linearitāte un stabilitāte ar laboratorijas references materiāla.
Elementu identifikācijas metožu salīdzinājums farmaceitiskajos paraugos
2019
Elementu identifikācijas metožu salīdzinājums farmaceitiskajos paraugos. Sleže V., zinātniskais vadītājs Mg. Chem. Bērtiņš M. Bakalaura darbs, 43 lappuses, 15 attēli, 12 tabulas, 31 literatūras avoti. Latviešu valodā. Organisko vielu sintēzēs tai starpā farmaceitisko preparātu ražošanā nereti tiek izmantoti katalizatori, lai ražošanas process notiktu ātrāk. Katalizatoru atliekas galaproduktā nav vēlamas, it īpaši farmaceitiskajos preparātos, kuri tiek lietoti cilvēku uzturā. Ir noteiktas direktīvas, kuras ierobežo katalizatoru maksimālās devas farmaceitiskajos preparātos. Tāpēc ir sastādītas ķīmiski analītiskās metodes, kuras spēj noteikt, cik daudz ir palikuši katalizatoru atlikumi.
Symplekin, a polyadenylation factor, prevents MOZ and MLL activity on HOXA9 in hematopoietic cells
2013
International audience; MOZ and MLL encoding a histone acetyltransferase and a histone methyltransferase, respectively, are targets for recurrent chromosomal translocations found in acute myeloblastic or lymphoblastic leukemia. We have previously shown that MOZ and MLL cooperate to activate HOXA9 gene expression in hematopoietic stem/progenitors cells. To dissect the mechanism of action of this complex, we decided to identify new proteins interacting with MOZ. We found that the scaffold protein Symplekin that supports the assembly of polyadenylation machinery was identified by mass spectrometry. Symplekin interacts and co-localizes with both MOZ and MLL in immature hematopoietic cells. Its …