Search results for "4-D"
showing 10 items of 955 documents
Metālorganiskā ietvara sintēze ar kovalenti saistītu 4-(dimetilamino)piridīnu
2020
Bakalaura darbā veikta metālorganiskā ietvara sintēze ar kovalenti saistītu 4-dimetilaminopiridīnu un pārbaudītas tā katalītiskās īpašības acilēšanas reakcijā. Literatūras apskatā aplūkota informācija par 4-dimetilaminopiridīnu heterogēno katalīzi un metālorganisko ietvaru sintēzi.
Vibrational dephasing of νs (OH) in 2,4-dichlorophenol
1990
Abstract A quantitative analysis of the infrared bandshape of ν s (OH) in intramolecularly hydrogen-bonded 2,4-dichlorophenol in a series of solvents is presented. A distinct dependence of bandshape indices and relaxation parameters on the polarity of solvent has been found. The band shifts to lower wavenumbers, broadens and becomes more intense with increasing solvent polarity; correspondingly, the correlation function decays faster and the correlation time diminishes. The results are compared with those for previously studied systems. Factors influencing the bandshape are discussed.
Determination and separation of diarylheptanoids from alder growing in Latvia
2015
The composition of diarylhepatnoids fraction isolated from bark of two alder species (grey alder and black alder) was studied. The efficiency of three extraction methods used for isolation of diarylhepatnoids from alder bark was compared. Two diarylhepatnoids: 1,7-bis-(3,4-dihydroxyphenyl)-heptan- 3-one-5-O-β-D-xylopyronoside (oregonin) and 1,7-bis-(3,4-dihydroxyphenyl)-3-hydroxyheptane-5-O-β-D- xylopyranoside were isolated from the bark of grey alder. The phenolic components of the extracts were analyzed by high-performance liquid chromatography (HPLC). Quantitative determination of oregonin was performed using an internal standard method. The results obtained show that alder barks are ric…
Amfifīlu 1,4-dihidropiridīna atvasinājumu 2,6-vietu modificēšana un to pašasociējošo īpašību pētījumi
2017
Amfifīlu 1,4-dihidropiridīna atvasinājumu 2,6-vietu modificēšana un to pašasociējošo īpašību pētījumi. Ragže J., darba vadītājs Dr.chem., vadošais pētnieks Pajuste K. Bakalaura darbs, 46 lappuses, 10 attēli, 5 tabulas, 59 literatūras avoti, 1 pielikums. Latviešu valodā. Raksturota šķīdinātāja ietekme “klika” reakcijai ar didodecil 2,6-bis(azidometil)-4-fenil-1,4-dihidropiridīna-3,5-dikarboksilātu. Sintezēti pieci jauni kandidātsavienojumi gēnu terapijai, aizvietojot bromu didodecil 2,6-bis((4-(brommetil)-1H-1,2,3-triazol-1-il)metil)-4-fenil-1,4-dihidropiridīna-3,5-dikarboksilātā ar dažādiem piridīniem. Noteikta kritiskā micellu koncentrācija, izmantojot dinamiskās gaismas izkliedes metodi. …
2,4-Dimetoksibenzaldehīda kondensācija ar etilcianoacetātu jonu šķidrumu vidēs
2019
2,4-Dimetoksibenzaldehīda kondensācija ar etilcianoacetātu jonu šķidrumu vidēs. Maševska Z., zinātniskais vadītājs prof., Dr.h.ķīm. Zicmanis A. Maģistra darbs, 54 lappuses, 14 attēli, 10 tabulas, 66 literatūras avoti, 19 pielikumi. Latviešu valodā. Darbā apkopota literatūra par jonu šķidrumu iegūšanas metodēm, to attīrīšanu, toksiskajām īpašībām, fizikāli-ķīmiskajām īpašībām. Apkopota informācija par Knēvenāgela kondensācijas reakcijas principiem. Sintezēti 17 strukturāli atšķirīgi jonu šķidrumi. Veiktas Knēvenāgela kondensācijas reakcijas jonu šķidrumu vidēs, izvērtēti iegūtie rezultāti. Iegūtie rezultāti salīdzināti ar citiem līdzīgiem pētījumiem.
Modulation of Contact Sensitivity Responses by Bacterial Superantigen
1995
Superantigens are potent modulators of the immune system, especially T cells. Therefore, we determined the influence of superantigens on the T-cell-mediated immune response, contact sensitivity. We chose the combination of staphylococcal enterotoxin B (SEB) as superantigen and 2,4-dinitrofluorbenzene (DNFB) as the contact sensitizer, because in BALB/c mice SEB reacts almost exclusively with V beta 8+ T cells, and these cells are capable of transferring contact sensitivity to DNFB from sensitized donors to naive syngeneic recipients. Pretreatment with a single intradermal injection of 50 ng SEB 24 h before DNFB exposure at the same site on the lower abdomen enhanced the induction of contact …
The SGLT2 inhibitor empagliflozin improves the primary diabetic complications in ZDF rats
2017
Hyperglycemia associated with inflammation and oxidative stress is a major cause of vascular dysfunction and cardiovascular disease in diabetes. Recent data reports that a selective sodium-glucose co-transporter 2 inhibitor (SGLT2i), empagliflozin (Jardiance®), ameliorates glucotoxicity via excretion of excess glucose in urine (glucosuria) and significantly improves cardiovascular mortality in type 2 diabetes mellitus (T2DM). The overarching hypothesis is that hyperglycemia and glucotoxicity are upstream of all other complications seen in diabetes. The aim of this study was to investigate effects of empagliflozin on glucotoxicity, β-cell function, inflammation, oxidative stress and endothel…
Shell/core differences in mu- and delta-opioid receptor modulation of dopamine efflux in nucleus accumbens
2008
The mu- and delta-opioid receptors located at the terminal level in nucleus accumbens are involved in the opiate modulation of dopamine release in this brain area. However, recent studies suggest that the effects of opioid drugs on the core subregion of nucleus accumbens may completely differ from those observed in the shell. We used in vivo microdialysis to simultaneously apply selective mu- and delta-opioid receptor agonists and to measure extracellular levels of dopamine in three subregions of the accumbens, namely shell, core, and the transition zone between them. The regional analysis of these subregions of the accumbens demonstrated that basal levels of dopamine and its metabolites we…
Assessment of the abuse potential of MDMA in the conditioned place preference paradigm: Role of CB1 receptors
2013
Numerous reports have highlighted the role of the endocannabinoid system in the addictive potential of MDMA (3,4-methylenedioxy-methamphetamine). A previous report showed that CB1 knockout (KOCB1) mice do not acquire MDMA self-administration, despite developing conditioned place preference (CPP). This contradiction could be due to the particular procedure of place conditioning used. The present work compares MDMA-induced CPP in KOCB1 mice using unbiased and biased procedures of place conditioning. In the unbiased procedure, MDMA induced CPP and reinstatement of the extinguished preference in wild type (WT) mice, but not in KOCB1 mice. In contrast, in a biased protocol of CPP, MDMA produced …
Genotyping of sex hormone-related pathways in benign and malignant human prostate tissues: data of a preliminary study.
2011
Prostate cancer (PCa) is a major health issue in Westernized countries, representing a common cause of morbidity and mortality in the elderly male population. Endogenous sex steroids, along with environmental factors (notably diet) and host immune and inflammatory responses, are likely to cooperate in the pathogenesis of the disease. Based on the assumption that a complex endocrine–inflammatory-immune interaction is primarily implicated in human PCa, we have investigated the interplay between sex steroids and inflammation in development and growth of human PCa. To this end, we have assessed nine functional single nucleotide polymorphisms (SNP)s of five genes involved in sex hormone-related …