20,123 research outputs found
Crystal structure of the heterotrimeric integrin-binding region of laminin-111
Laminins are cell - adhesive glycoproteins that are essential for basement membrane assembly and function. Integrins are important laminin receptors, but their binding site on the heterotrimeric laminin s is poorly defined structurally. We report the crystal structure at 2.13 Å resolution of a minimal integrin - binding fragment of mouse laminin - 111, consisting of ~50 resid ues of α 1 β 1 γ 1 coiled coil and the first three lam inin G - like (LG) domains of the α 1 chain . The LG domains adopt a triangular arrangem ent, with the C - terminus of the coiled coil situated between LG1 and LG2. The critical integrin - binding glutamic acid residue in the γ 1 chain tail is surface - exposed and predicted to bind to the metal ion - dependent adhesion site in the integrin β 1 subunit. Additional contacts to the integrin are likely to be made by the LG1 and LG2 surfaces adjacent to the γ 1 chain tail, which are notably conserved and free of obstructing glycans
The attitudes, feelings and experiences of online gamers: a qualitative analysis
The playing of massively multiplayer online role-playing games (MMORPGs) is now a highly popular leisure activity. The present study set out to explore the attitudes, experiences, and feelings of online gamers. The study entailed 71 interviews with online gamers (52 males, 19 females) from 11 different countries. Six main themes emerged from the analyses of the interview transcripts: (a) online gaming and integration into day-to-day lives; (b) online gaming, excessive play, and problems; (c) addiction; (d) psychosocial impact of online gaming; (e) online gaming, dissociation, and time loss; and (f) online gaming and the alleviation of negative feelings and mood states. These findings specifically showed how gamers used MMORPGs to alleviate negative feelings and provided detailed descriptions of personal problems that had arisen due to playing MMORPGs. The implications of these findings are discussed in relation to previous qualitative and quantitative research in the area
Water for rural development: Background paper on water for rural development prepared for the World Bank
Water management / Irrigation management / Rural development / Water resources development / Small scale systems / Land management / Groundwater / Environment / Health / Water policy / Institutions / Food consumption / Water supply / Water demand / Water allocation / Crop yield / Cereals / Water scarcity / Food production / Food security / Crop production / Population growth
Role of microenvironment in the mixed Langmuir-Blodgett films
This paper reports the pi-A isotherms and spectroscopic characteristics of
mixed Langmuir and Langmuir-Blodgett (LB) films of non-amphiphilic carbazole
(CA) molecules mixed with polymethyl methacrylate (PMMA) and stearic acid (SA).
pi-A isotherm studies of mixed monolayer and as well as also the collapse
pressure study of isotherms definitely conclude that CA is incorporated into
PMMA and SA matrices. However CA is stacked in the PMMA/SA chains and forms
microcrystalline aggregates as is evidenced from the scanning electron
micrograph picture. Nature of these aggregated species in the mixed LB films
has been revealed by UV-Vis absorption and fluorescence spectroscopic studies.
The presence of two different kinds of band systems in the fluorescence spectra
of the mixed LB films have been observed. This may be due to the formation of
low dimensional aggregates in the mixed LB films. Intensity distribution of
different band system is highly sensitive to the microenvironment of two
different matrices as well as also on the film thicknessComment: 11 pages, 5 figure
Formation of complex Langmuir and Langmuir-Blodgett films of water soluble rosebengal
This communication reports the formation of complex Langmuir monolayer at the
air-water interface by charge transfer types of interaction with the water
soluble N- cetyl N, N, N trimethyl ammonium bromide (CTAB) molecules doped with
rosebengal (RB), with the stearic acid (SA) molecules of a preformed SA
Langmuir monolayer. The reaction kinetics of the formation of RB-CTAB-SA
complex monolayer was monitored by observing the increase in surface pressure
with time while the barrier was kept fixed. Completion of interaction kinetics
was confirmed by FTIR study. This complex Langmuir films at the air-water
interface was transferred onto solid substrates at a desired surface pressure
to form multilayered Langmuir-Blodgett films. Spectroscopic characterizations
reveal some molecular level interactions as well as formation of
microcrystalline aggregates depending upon the molar ratios of CTAB and RB
within the complex LB films. Presence of two types of species in the complex LB
films was confirmed by fluorescence spectroscopy.Comment: 13 pages, figures
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