Search results for "Donor"
showing 10 items of 436 documents
Ab initio calculations of Nb doped SrTiO3
2010
We present and discuss the results of the large scale Hartree–Fock calculations of Nb impurities substituting for Ti ions in SrTiO3 using ab initio computer code CRYSTAL and several supercells containing up to 135 atoms. The local structure optimisation, the electronic charge redistribution, chemical bond covalence and the band-structure changes induced by the defect are analysed. According to the results of our calculations, Nb is a shallow donor; six nearest O ions are slightly displaced outwards from the Nb ion. The calculated bond population between nearest Ti and O ions (64 me) is much larger than that between Nb and O ions (8 me), since Nb impurity is more ionic than the host Ti.
Rīcības ar cilvēka audiem un orgāniem regulējums Latvijā
2019
Darba tēma ir „Rīcības ar cilvēka audiem un orgāniem regulējums Latvijā”. Šobrīd, kad pasaulē strauji attīstās tāda medicīnas nozare kā cilvēka audu un orgānu transplantācija, pieaug arī cilvēka ķermeņa nelikumīgas izmantošanas gadījumi. Lai arī audu un orgānu nelikumīgas izmantošanas prakse Latvijā ir reti sastopama, arī šiem gadījumiem jāparedz atbilstošs regulējums starptautiskajiem tiesību avotiem. Darba mērķis bija noskaidrot, par kādām nelikumīgām darbībām ar cilvēka audiem un orgāniem ir paredzēta kriminālatbildība Latvijā, kādi ir embriju (fetālo) audu izmantošanas tiesiskie aspekti, un salīdzināt Latvijas tiesisko regulējumu ar starptautisko un ārvalstu regulējumu. Transplantācijas…
Prolactin supplementation to culture medium improves beta-cell survival
2010
OBJECTIVES.: Recent studies demonstrated that prolactin (PRL) has beneficial effects on β cells for islet transplantation. We examined the effect of human recombinant PRL (rhPRL) supplementation to the culture media to determine its potential use in the context of clinical islet transplantation. MATERIALS AND METHODS.: Each human islet isolated from 14 deceased multiorgan donors was cultured in Miami modified media-1 supplemented with or without rhPRL (500 μg/L) for 48 hr. β-Cell survival and proliferation (BrdU and Ki-67) were determined by laser scanning cytometry. The cytoprotective effects of rhPRL against noxious stimuli were assessed by flow cytometry (tetramethylrhodamine ethyl ester…
Katalizatory i proces koordynacyjnej polimeryzacji etylenu - eksperyment i teoria
2004
Badania eksperymentalne i teoretyczne koordynacyjnej polimeryzacji etylenu przeprowadzono wobec katalizatorów otrzymanych z prekursorów - kompleksów halogenków Ti, Zr, Hf, V z organicznymi zasadami Lewisa, nośnika magnezowego [MgCl2(THF)2] i związków glinoorganicznych. Określono zależnosć pomiędzy rodzajem halogenków w prekursorze a aktywnością katalizatora wanadowego. Ustalono profile energetyczne reakcji insercji i terminacji (beta-eliminacji) oraz przeniesienia atomu wodoru beta. Obliczone wartości barier insercji, a także energii wiązania etylenu do centrum aktywnego dobrze korelują z wynikami polimeryzacji. Stwierdzono występowanie w centrach aktywnych oddziaływań agostycznych, które o…
Compactness in Groups of Group-Valued Mappings
2022
We introduce the concepts of extended equimeasurability and extended uniform quasiboundedness in groups of group-valued mappings endowed with a topology that generalizes the topology of convergence in measure. Quantitative characteristics modeled on these concepts allow us to estimate the Hausdorff measure of noncompactness in such a contest. Our results extend and encompass some generalizations of Fréchet–Šmulian and Ascoli–Arzelà compactness criteria found in the literature.
Comparison of Luminescence in LiGaO2, Al2 O3 -Ga and Al2 O3 -Li Crystals
2018
We have studied luminescence of LiGaO 2 , Al 2 O 3 -Ga and Al 2 O 3 -Li crystals in order to reveal the nature of luminescence centres and mechanisms in these crystals. In Al 2 O 3 -Ga presence of Ga impurities determines occurrence of the 280 nm emission band, which demonstrates intra-centre character in photoluminescence and recombination character under X-ray irradiation. In Al 2 O 3 -Li crystal lithium induced luminescence is presented with the 326 nm band, which has a recombination character. Basing on spectral similarity of the main luminescence bands in pure LiGaO 2 crystal with the dopant-induced emission bands in Al 2 O 3 , and on peculiarities of the X-ray induced thermoluminescen…
Multivalent N-donor ligands for the construction of coordination polymers and coordination polymer gels
2018
This work describes the synthesis and characterisation of several multivalent N-donor ligands and their coordination compounds and the use of these ligands in the construction of coordination polymers and coordination polymer gels. The project can be divided into two parts. The first part of the research is focused on the coordination chemistry of ring-substituted biimidazoles in acidic media. The dependence of the formation of ion pairs and zwitterionic, especially zinc and copper containing coordination compounds on the pH of the reaction medium and ring-substituents of the ligand were examined. The second part of the study deals with the preparation of Ag, Zn and Cu coordination polymers…
Prolonging in utero-like oxygenation after birth diminishes oxidative stress in the lung and brain of mice pups☆
2013
Background Fetal-to-neonatal transition is associated with oxidative stress. In preterm infants, immaturity of the antioxidant system favours supplemental oxygen-derived morbidity and mortality. Objectives To assess if prolonging in utero-like oxygenation during the fetal-to-neonatal transition limits oxidative stress in the lung and brain, improving postnatal adaptation of mice pups. Material and methods Inspiratory oxygen fraction (FiO2) in pregnant mice was reduced from 21% (room air) to 14% (hypoxia) 8–12 h prior to delivery and reset to 21% 6–8 h after birth. The control group was kept at 21% during the procedure. Reduced (GSH) and oxidized (GSSG) glutathione and its precursors [γ-glut…
Uztura nozīme asins un asins komponentu donoriem. Hilozes profilakse.
2015
Bakalaura darba „Uztura nozīme asins un asins komponentu donoriem. Hilozes profilakse” mērķis ir noskaidrot uztura nozīmi asins donoriem hilozes profilaksei. Pētījums veikts X asins sagatavošanas nodaļa.. Pētījumā respondenti: 9 plazmas donori, ar 8 no tiem tika runāts 2 reizes ar 2 nedēļu intervālu, ar 1 respondentu tika runāts 1 reizi. Pētījumā jautājumi: Kā donora uzturs ietekmē asins un asins komponentu hilozi? Vai donori ir gatavi mainīt savus uztura ieradumus lai uzlabotu asins kvalitāti?. Pielietota kvalitatīva pētījuma metode- kontentanalize. Datu pārstrāde– Microsoft Office Word 2007. Iegūtie rezultāti parāda, ka donora uzturs ietekmē asins un asins komponentu hilozi un mainoties d…
Vascularized composite allotransplantation - a Council of Europe position paper
2017
After more than 120 hand-upper extremity and 37 face transplant procedures performed worldwide, vascularized composite allotransplantation (VCA) now falls under the scope of organ transplant legislation in Europe and the United States. While in the USA, VCA has been considered as standard care since 2014, VCA in Europe is still performed through clinical research trials, except in United Kingdom. However, after two decades of favourable experience with upper extremity transplantation (UET), professionals in Europe are proposing hand allotransplantation as “controlled standard” care, as opposed to face transplantation (FT), which is still a challenging activity. The European Committee on Org…