A remote labeling method has been developed to determine (18)O kinetic isotope effects (KIEs) in Ras-catalyzed GTP hydrolysis. Substrate mixtures consist of (13)C-depleted GTP and [(18)O,(13)C]GTP that contains (18)O at phosphoryl positions of mechanistic interest and (13)C at all carbon positions of the guanosine moiety. Isotope ratios of the nonvolatile substrates and products are measured by...

The beta protein, a dimeric ring-shaped clamp essential for processive DNA replication by Escherichia coli DNA polymerase III holoenzyme, is assembled onto DNA by the gamma complex. This study examines the clamp loading pathway in real time, using pre-steady state fluorescent depolarization measurements to investigate the loading reaction and ATP requirements for the assembly of beta onto DNA. ...

Beta-delayed neutron emission and $\ensuremath{\beta}$-delayed fission ($\ensuremath{\beta}\mathrm{df}$) probabilities were calculated for heavy, neutron-rich nuclei using the Los Alamos coupled quasiparticle random-phase approximation plus Hauser-Feshbach ($\mathrm{QRPA}+\mathrm{HF}$) approach. In this model, compound nucleus is initially populated by $\ensuremath{\beta}$ decay followed throug...

The mechanism of G protein beta gamma subunit (G beta gamma)-induced activation of the muscarinic K+ channel (KACh) in the guinea pig atrial cell membrane was examined using the inside-out patch clamp technique. G beta gamma and GTP-gamma S-bound alpha subunits (G alpha *'s) of pertussis toxin (PT)-sensitive G proteins were purified from bovine brain. Either in the presence or absence of Mg2+, ...

Finding an effective method to quantify species compositional changes in time and space has been an important task for ecologists and biogeographers. Recently, exploring regional floristic patterns using data derived from satellite imagery, such as the normalized difference vegetation index (NDVI) has drawn considerable research interests among ecologists. Studies have shown that NDVI could be ...

Background: Periodontitis is an inflammatory disease of tooth-supporting tissues. The present study was conducted to evaluate Interleukin-10 (IL-10) and Interferon gamma (IFN-γ) levels in gingival crevicular fluid (GCF) of patients with chronic periodontitis. Materials and Methods: This case-control study was carried out on 60 men including 30 smokers and 30 age-matched non-smokers. The ...

Ecological interactions between aboveground and belowground biodiversity have received many attentions in the recent decades. Although soil biodiversity declined with the decrease of plant diversity, many previous studies found plant species identities were more important than plant diversity in controlling soil biodiversity. This study focused on the responses of soil biodiversity to the alter...

The $\beta$ decay of the neutron-rich $^{134}$In and $^{135}$In was investigated experimentally in order to provide new insights into nuclear structure tin isotopes with magic proton number $Z=50$ above $N=82$ shell. $\beta$-delayed $\gamma$-ray spectroscopy measurement performed at ISOLDE facility CERN, where indium were selectively laser-ionized on-line mass separated. Three $\beta$-decay bra...

Using the conservation of energy and momentum during collisions of any two shells, we consider the efficiency of gamma-ray bursts by assuming that the ejecta from the central engine are equally massive and have the same Lorentz factors. We calculate the efficiency and the final Lorentz factor of the merged whole shell for different initial diversities of Lorentz factors and for different micros...