Search results for "actin"
showing 10 items of 1375 documents
Dispersion from C
2019
Resonance assignment of intrinsically disordered proteins is remarkably challenging due to scant chemical shift dispersion arising from conformational heterogeneity. The challenge is even greater if repeating segments are present in the amino acid sequence. To forward unambiguous resonance assignment of intrinsically disordered proteins, we present iHACANCO, HACACON and (HACA)CONCAHA, three Hα-detected 4D experiments with Cα as an additional dimension. In addition, we present (HACA)CON(CA)NH and (HACA)N(CA)CONH, new 4D Hα-start, HN-detect experiments which have two NH dimensions to enhance peak dispersion in a sequential walk through C′, NH and HN, and provide more accurate NH/HN chemical s…
Resonance ionization spectroscopy for trace analysis and fundamental research
1994
Resonance ionization spectroscopy (RIS) and its combination with mass spectrometry (RIMS) have grown to become powerful techniques, which offer high sensitivity as well as elemental and isotopic selectivity. The principles of RIS and RIMS are introduced; they primarily concern the analysis of the optical spectra for the choice of efficient excitation schemes and the suitable design of the experimental apparatus. Recent applications span from studies of short-lived isotopes at on-line mass separators to a wide variety of trace analysis applications for radioactive isotopes, which can range from measurements of solar neutrino flux to environmental assessment.
Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation
2015
Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel. Through measurement of the (230)Th/(234)U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare-earth-element content and the (87)Sr/(86)Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of (236)U and (239)Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence.
A method for rapid generation of competitive standard molecules for RT-PCR avoiding the problem of competitor/probe cross-reactions.
1995
The analysis of gene expression is a widespread issue in a growing number of fields such as molecular genetics, immunology, and medical diagnostics. The ideal method for mRNA detection should be fast, inexpensive, sensitive, and reliable. Well-elaborated standard methods such as Northern hybridization, Sl-mapping, and RNAse protection are useful and recommended, but only reverse transcription PCR (RT-PCR) gives the highest possible sensitivity required. For many issues it is necessary not only to detect a distinct mRNA but to compare changes in mRNA levels. The use of RT-PCR for such semiquantitative and quantitative approaches resolves problems attributable to the intrinsic property of PCR…
α-parvin is required for epidermal morphogenesis, hair follicle development and basal keratinocyte polarity
2020
Epidermal morphogenesis and hair follicle (HF) development depend on the ability of keratinocytes to adhere to the basement membrane (BM) and migrate along the extracellular matrix. Integrins are cell-matrix receptors that control keratinocyte adhesion and migration, and are recognized as major regulators of epidermal homeostasis. How integrins regulate the behavior of keratinocytes during epidermal morphogenesis remains insufficiently understood. Here, we show that alpha-parvin (alpha-pv), a focal adhesion protein that couples integrins to actin cytoskeleton, is indispensable for epidermal morphogenesis and HF development. Inactivation of the murine alpha-pv gene in basal keratinocytes res…
Epidermolysis Bullosa Simplex-Type Mutations Alter the Dynamics of the Keratin Cytoskeleton and Reveal a Contribution of Actin to the Transport of Ke…
2003
Dominant keratin mutations cause epidermolysis bullosa simplex by transforming keratin (K) filaments into aggregates. As a first step toward understanding the properties of mutant keratins in vivo, we stably transfected epithelial cells with an enhanced yellow fluorescent protein-tagged K14R125C mutant. K14R125C became localized as aggregates in the cell periphery and incorporated into perinuclear keratin filaments. Unexpectedly, keratin aggregates were in dynamic equilibrium with soluble subunits at a half-life time of <15 min, whereas filaments were extremely static. Therefore, this dominant-negative mutation acts by altering cytoskeletal dynamics and solubility. Unlike previously post…
Maturation of epidermal Langerhans cells: increased expression of beta- and gamma-actin isoforms as a basis of specialized cell functions.
1999
Epidermal Langerhans cells (LC) represent immature dendritic cells. During in vitro culture in the presence of keratinocytes they mature into potent immunostimulatory cells for naive T cells. This process is thought to simulate in vivo maturation of LC following activation by antigen contact. Maturation of LC is accompanied by morphological alterations. Applying a differential screening procedure we isolated differentially expressed cDNAs involved in the maturation events including cDNAs of the cytoskeletal actin isoforms beta- and gamma-actin. Stronger signals with hybridization probes derived from cultured LC compared with probes derived from freshly isolated LC indicate upregulation of a…
Mobility of the Singly-Charged Lanthanide and Actinide Cations: Trends and Perspectives
2020
The current status of gaseous transport studies of the singly-charged lanthanide and actinide ions is reviewed in light of potential applications to superheavy ions. The measurements and calculations for the mobility of lanthanide ions in He and Ar agree well, and they are remarkably sensitive to the electronic configuration of the ion, namely, whether the outer electronic shells are 6s, 5d6s or 6s$^2$. The previous theoretical work is extended here to ions of the actinide family with zero electron orbital momentum: Ac$^+$ (7s$^2$, $^1$S), Am$^+$ (5f$^7$7s $^9$S$^\circ$), Cm$^+$ (5f$^7$7s$^2$ $^8$S$^\circ$), No$^+$ (5f$^{14}$7s $^2$S) and Lr$^+$ (5f$^{14}$7s$^2$ $^1$S). The calculations rev…
Fast preparation and gas-chromatographic separation of lanthanide and actinide hexafluoroacetylacetonates
1986
A fast method for the separation of lanthanide elements by gas chromatography of their hexafluoroacetylacetonates is described. Individual lanthanides can be isolated within a few minutes, and the whole group can be separated in less than 10 min. The hexafluoroacetylacetonates are applied in form of mixed complexes with tri-n-butyl phosphate or trioctylphosphine oxide prepared by fast extraction into quasi-solid solvents. The applicability of this method for the separation of trivalent actinide elements is shown, including the fast preparation of thin counting samples.
Fast volatilization of some lanthanide and actinide elements from titanium surfaces
1989
The ad- and desorption of trace quantities of the lanthanide elements lanthanum, praseodymium, neodymium, samarium, europium, gadolinium, dysprosium, and ytterbium and of the actinide elements americium and curium were investigated by thermochromatographic and isothermal measurements with hot titanium columns. The adsorption enthalpies deduced from the experimental data are in reasonable agreement with calculated values which indicate considerable variations in volatility under such conditions. More volatile elements can quickly be separated from less volatile elements by heating the mixture on titanium in high vacuum.