Search results for "Fluorescence"
showing 10 items of 2463 documents
Hidroksilapatītu analītiskās raksturošanas metožu izstrāde
2018
Hidroksilapatītu analītiskās raksturošanas metožu izstrāde. Grebņevs V., zinātniskais vadītājs Dr. chem., prof. Vīksna A. Bakalaura darbs, 100 lappuses, 24 attēli, 59 tabulas, 79 literatūras avoti, 12 pielikumi. Latviešu valodā. Darbā apkopota literatūra par hidroksilapatītiem, to īpašībām, veidiem, izmantošanu un sintēzi, par klasiskajām un modernajām kalcija un fosfora kvantitatīvās noteikšanas metodēm tajos. Eksperimentālajā daļā veikta kalcija un fosfora kvantitatīvā noteikšana hidroksilapatīta paraugā no ražotāja Cambioceramics. Abi elementi tika kvantificēti ar gravimetriju, fotometriju, viļņu dispersīvo rentgenfluorescences spektrometriju, induktīvi saistītās plazmas optiskās emisija…
Implementation of a double-scanning technique for studies of the Hanle effect in rubidium vapor
2007
We have studied the resonance fluorescence of a room-temperature rubidium vapor exited to the atomic 5P3/2 state (D2 line) by powerful single-frequency cw laser radiation (1.25 W/cm^2) in the presence of a magnetic field. In these studies, the slow, linear scanning of the laser frequency across the hyperfine transitions of the D2 line is combined with a fast linear scanning of the applied magnetic field, which allows us to record frequency-dependent Hanle resonances from all the groups of hyperfine transitions including V- and Lambda - type systems. Rate equations were used to simulate fluorescence signals for 85Rb due to circularly polarized exciting laser radiation with different mean fre…
HPLC-SEC: a new approach to characterise complex wastewater effluents
2016
ABSTRACTThis work investigates the use of HPLC-SEC to characterise dissolved organic matter (DOM) of complex wastewater effluents. A silica-based column, sodium acetate eluent and multiple detections were employed: UV-254 absorbance for humictype, and tryptophan-like (Ex/Em = 270/355) and tyrosine-like (Ex/Em = 270/310) fluorescence for protein type compounds. Effects of eluent pH, eluent ionic strength and injection volume on separation efficiency were tested. Humic-type and protein-type fractions were clearly differentiated and eluted within and out of calibration range. Eluent ionic strength had the greatest influence on global resolution; the lowest eluent concentration of 0.01 M produc…
Array-CGH and clinical characterization in a patient with subtelomeric 6p deletion without ocular dysgenesis
2011
Subtelomeric terminal 6p deletion has been recognized as a clinically identifiable syndrome including facial dysmorphism, malformation of the anterior eye chamber, hearing loss, heart defect and developmental delay. Genotype –phenotype correlations of previously published patients have been strongly suggested anterior eye segment anomalies as one of major malformation of the syndrome if the critical 6p25 region containing the FOXC 1 gene. In addition it has been hypothesized the presence in this region of one or more genes involved in hearing loss. We report on a case of terminal 6p deletion in a 47, XYY karyotype. Further characterization of the deletion with array comparative genome hybri…
Hepatitis B virus maturation is sensitive to functional inhibition of ESCRT-III, Vps4, and gamma 2-adaptin.
2007
ABSTRACT Hepatitis B virus (HBV) is an enveloped DNA virus that presumably buds at intracellular membranes of infected cells. HBV budding involves two endocytic host proteins, the ubiquitin-interacting adaptor γ2-adaptin and the Nedd4 ubiquitin ligase. Here, we demonstrate that HBV release also requires the cellular machinery that generates internal vesicles of multivesicular bodies (MVBs). In order to perturb the MVB machinery in HBV-replicating liver cells, we used ectopic expression of dominant-negative mutants of different MVB components, like the ESCRT-III complex-forming CHMP proteins and the Vps4 ATPases. Upon coexpression of mutated CHMP3, CHMP4B, or CHMP4C forms, as well as of ATPa…
Characterization of Anti Liver Kidney Microsomal Antibody Associated with Chronic HDV Infection by Immunoblotting
1989
Cytoplasmic antibodies directed against antigen(s) present in the membranes of the endoplasmic reticulum have been reported in a proportion of patients with chronic HBV-HDV infection (Crivelli et al.,1981). While the immunofluorescence (IFL) pattern associated with LKMδ antibody is quite similar to that of the liver kidney microsomal antibody (LKM) described by Rizzetto et al. (1973) and associated with an autoimmune type of chronic active hepatitis (Thomas, 1980), the target antigen(s) was supposed to be different on the basis of blocking experiments. The target antigen of LKM antibody has been recently partially identified as a 50kD protein located in the membranes of the smooth endoplasm…
Infection of Soybean Plants with the Insect Bacterial Symbiont Burkholderia gladioli and Evaluation of Plant Fitness
2017
To investigate the establishment and consequences of host-microbe interactions, it is important to develop controlled infection assays suitable for each system, as well as appropriate methods to evaluate successful infection and its associated effects. Here, we describe a procedure for bacterial inoculation of soybean plants, followed by the assessment of systemic infection and impact on plant fitness. Soybean (Glycine max) seedlings were mechanically wounded using a device that mimics insect herbivory and inoculated with known cell numbers of Burkholderia gladioli bacteria previously isolated from an insect host. The impact on the plants was evaluated by monitoring changes in height, time …
Host plant and arbuscular mycorrhizal fungi show contrasting responses to temperature increase: Implications for dioecious plants
2014
Individual plants live in complex environments where they interact with other organisms such as herbivores, pollinators, fungi and pathogens. The influence of rising temperature on biotic interactions has begun to receive attention, and is an important research frontier currently. However, the belowground interactions with organisms such as arbuscular mycorrhizal (AM) fungi have received little attention so far. In this study, we investigated the response of the dioecious plant Antennaria dioica and its AM fungi to increased temperature in a controlled environment simulating the period of growth of A. dioica in central Finland. Specifically, we evaluated the effect of rising temperature on …
Ancient Haplotypes at the 15q24.2 Microdeletion Region Are Linked to Brain Expression of MAN2C1 and Children's Intelligence
2016
The chromosome bands 15q24.1-15q24.3 contain a complex region with numerous segmental duplications that predispose to regional microduplications and microdeletions, both of which have been linked to intellectual disability, speech delay and autistic features. The region may also harbour common inversion polymorphisms whose functional and phenotypic manifestations are unknown. Using single nucleotide polymorphism (SNP) data, we detected four large contiguous haplotype-genotypes at 15q24 with Mendelian inheritance in 2,562 trios, African origin, high population stratification and reduced recombination rates. Although the haplotype-genotypes have been most likely generated by decreased or abse…
p16INK4A (CDKN2A) gene deletion is a frequent genetic event in synovial sarcomas.
2006
We assessed the frequency of genomic deletion of p16 INK4A (CDKN2A) in synovial sarcomas (SSs) and its possible association with immunoexpression of p16 and cyclin D1 and the Ki-67 proliferation index using dualcolor fluorescence in situ hybridization (FISH) on tissue microarray sections of 41 histologically and molecularly confirmed SSs. A heterozygous p16 INK4A gene deletion was identified in 28 (74%) of 38 cases, with 25 (89%) of them showing abnormal p16 protein expression (20 negative and 5 heterogeneous). Of 25 cases, 19 (76%) exhibiting increased cyclin D1 expression also demonstrated heterozygous p16 INK4A deletion. No significant association was observed between p16 INK4A deletion …