We introduce a methodology, fluorescence lifetime imaging (FLIM), in which the contrast depends on at each point two-dimensional image and not local concentration and/or intensity of fluorophore. used FLIM to create images NADH when free solution bound malate dehydrogenase. This represents challenging case for because decay times are just 0.4 1.0 ns states, respectively. In present apparatus, created from series phase-sensitive obtained with gain-modulated intensifier recorded charge-coupled...

Human growth has been viewed as a continuous process characterized by changing velocity with age. Serial length measurements of normal infants were assessed weekly ( n = 10), semiweekly 18), and daily 3) (19 females 12 males) during their first 21 months. Data show that in occurs discontinuous, aperiodic saltatory spurts. These bursts 0.5 to 2.5 centimeters amplitude intervals separated no measurable (2 63 days duration). data suggest 90 95 percent development infancy is growth-free...

We used 2-GHz frequency-domain fluorometry to examine the intensity decays of N-acetyl-L-tryptophamide (NATA) and protein staphylococcal nuclease in presence absence quenching by oxygen or acrylamide.When analyzed with a multiexponential model, NATA both become more heterogeneous quenching.We attribute increased complexity transient effects equivalently time-dependent rate constant for quenching.The data were using Smoluchowski model (exp(-t/T -ab&) radiation which is known correct some...

In water, glucagon exists in an equilibrium between a trimer which more than half of the peptide groups are alpha-helical configuration and monomer has random coil with few residues. The thermodynamics this self-association have been evaluated by studying temperature- concentration-dependence mean residue ellipticity at 220 nm. enthalpy entropy changes association were negative all temperatures 5 degrees 50 had large temperature dependencies. Usually that involves nonpolar is considered to...

A quantitative model has been developed for the cooperative oxygenation of human hemoglobin. The correlates structural and energetic features ligand-linked subunit interactions within tetrameric molecule coupling these to binding oxygen Bohr protons. Recent findings are incorporated regarding (i) sites regulatory energy change molecule, (ii) nature effect tetramers dimers, (iii) fractional proton release at each stage oxygenation, (iv) relative probabilities alpha beta chains tetramer, (v)...

The fluorescence of rhodamine 6G is completely quenched in glucagon solutions 0.6 M K2HOP4 at pH 10.6. absorption red-shifted by the same reaction. A single molecule appears to be bound a hydrophobic patch center trimer glucagon. Since monomer has almost no organized structure this site exists only associated form self-association been determined from variation and measured over 60-fold range dye concentration. constant agrees with values other methods absence dye. binding isotherms shift...

To evaluate the temporal mechanisms that give rise to spontaneous proestrous surge of luteinizing hormone (LH) in rat, we have applied deconvolution analysis earlier immunoreactive LH concentration vs. time profiles obtained by sampling blood proestrus at 2- 3-min intervals 10 animals over a span 160-300 min. Six other were bled 6-min on day 1 diestrus. Deconvolution permitted us calculate number, duration, amplitude (maximal release rates), and mass underlying secretory bursts...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThree-state combinatorial switch models as applied to the binding of oxygen by human hemoglobinMartin Straume and Michael L. JohnsonCite this: Biochemistry 1988, 27, 4, 1302–1310Publication Date (Print):February 23, 1988Publication History Published online1 May 2002Published inissue 23 February 1988https://pubs.acs.org/doi/10.1021/bi00404a032https://doi.org/10.1021/bi00404a032research-articleACS PublicationsRequest reuse permissionsArticle...

The deliberate use of chemical, biological, radiological, and nuclear (CBRN) materials in war or terrorist attacks is perceived as a great threat globally. In the event release CBRN agents, protection by means medical countermeasures (MedCMs) could reduce health vulnerability. Nonetheless, for some diseases caused these innovative MedCMs do not exist many those that might be readily available. Inappropriate research development funding government procurement efforts can result adverse...