Search results for "fluorescense"
showing 4 items of 4 documents
Bio-imaging with the helium-ion microscope: A review
2021
Scanning helium-ion microscopy (HIM) is an imaging technique with sub-nanometre resolution and is a powerful tool to resolve some of the tiniest structures in biology. In many aspects, the HIM resembles a field-emission scanning electron microscope (FE-SEM), but the use of helium ions rather than electrons provides several advantages, including higher surface sensitivity, larger depth of field, and a straightforward charge-compensating electron flood gun, which enables imaging of non-conductive samples, rendering HIM a promising high-resolution imaging technique for biological samples. Starting with studies focused on medical research, the last decade has seen some particularly spectacular …
Microbial Food Web Components as Potential Indicators of Urban Hydroecosystems / Mikrobiālās ķēdēs Komponentu Potenciāls Pielietojums Urbānās Vides Ū…
2015
Abstract Assessment of the effect of urbanisation on biodiversity and ecological impact studies are focused on plants, birds, terrestrial arthropods, and relatively few studies have been on aquatic organisms. The aim of this study was to investigate the microbial food web components as potential indicators of the trophic state of two small natural lakes (Gaiļezers, Bābelītis), two artificial lakes or reservoirs (created after excavation activities before 20 years) and the Gulf of Riga seaside Vecāķi beach (littoral), all of which are located in the city of Riga or close to it. Analysis of samples was conducted from April til October 2014 by epifluorescense microscopy for pico and nanoplankt…
Analīzes metožu attīstīšana nātru tēju elementsastāva noteikšanai
2015
Tā kā organiskā materiāla izpēte ar dažādām analīzes metodēm sagādā grūtības, tad šajā darbā tiks izvērtēta analīzes metožu atbilstība dzelzs, kālija un kalcija satura noteikšanai lielo nātru (Urtica dioica L.) tējās. Dzelzs saturs noteikts ar spektrofotometrijas metodi, kālijs un kalcijs – ar liesmas fotometrijas, bet visi 3 elementi – ar rentgenfluorescenses spektrometrijas metodi. Paraugi sagatavoti tablešu formā, ar sauso vai slapjo mineralizāciju. Spektrofotometrijas metode nav piemērota dzelzs, bet liesmas fotometrija – kalcija satura noteikšanai nātru tējās. Kāliju var noteikt precīzi ar abām metodēm. Rentgenfluorescenses spektrometrija ir piemērota visu minēto elementu noteikšanai. …
Human apolipoprotein A-I natural variants: molecular mechanisms underlying amyloidogenic propensity
2012
Human apolipoprotein A-I (apoA-I)-derived amyloidosis can present with either wild-type (Wt) protein deposits in atherosclerotic plaques or as a hereditary form in which apoA-I variants deposit causing multiple organ failure. More than 15 single amino acid replacement amyloidogenic apoA-I variants have been described, but the molecular mechanisms involved in amyloid-associated pathology remain largely unknown. Here, we have investigated by fluorescence and biochemical approaches the stabilities and propensities to aggregate of two disease-associated apoA-I variants, apoA-IGly26Arg, associated with polyneuropathy and kidney dysfunction, and apoA-ILys107-0, implicated in amyloidosis in severe…