The rapid electronic state dynamics that occur prior to charge separation in the photosynthetic reaction center of Rhodobacter sphaeroides R-26 are investigated by “two-color” wavelength-resolved pump-probe and anisotropy measurements. A narrow band (40 fs duration transform limited) pump pulse is used to selectively excite reaction center pigments: the accessory bacteriochlorophyll (B), the up...

Carbodiimides (RN)2C were reductively coupled with Li powder into [{Li(py)2}2(mu-C2N4R4)] (R = p-tolyl) (1) and [{Li(THF)}2(mu-C2N4R4)] (R = Cy) (2), and 2 reacted with UCl4 to give [Li(py)4]2[{UCl4(py)}2(mu-C2N4R4)] (R = Cy) (3); the crystal structures of 1 and 3 x 2py, the first oxalamidino compounds of an alkali metal and of a 5f-element, have been determined.

WW domains target proline-tyrosine (PY) motifs and frequently function as tandem pairs. When studied in isolation, single WW domains are notably promiscuous and regulatory mechanisms are undoubtedly required to ensure selective interactions. Here, we show that the fourth WW domain (WW4) of Suppressor of Deltex, a modular Nedd4-like protein that down-regulates the Notch receptor, is the primary ...

The essential pre-mRNA splicing factor, U2AF(65), guides the early stages of splice site choice by recognizing a polypyrimidine (Py) tract consensus sequence near the 3' splice site. Since Py tracts are relatively poorly conserved in higher eukaryotes, U2AF(65) is faced with the problem of specifying uridine-rich sequences, yet tolerating a variety of nucleotide substitutions found in natural P...

We retrospectively screened 1836 men who have sex with men (MSM) participating in the Amsterdam Cohort Studies (1984-2003) for hepatitis C virus (HCV) antibodies. HCV incidence was 0.18/100 person-years (PY) in human immunodeficiency virus (HIV)-positive MSM (8/4408 PY [95% confidence interval {CI}, 0.08-0.36]) but was 0/100 PY in MSM without HIV (0/7807 PY [95% CI, 0.00-0.05]). After 2000, HCV...

A protein module called the WW domain recognizes and binds to a short oligopeptide called the PY motif, PPxY, to mediate protein-protein interactions. The PY motif is present in the transcription activation domains of a wide range of transcription factors including c-Jun, AP-2, NF-E2, C/EBPalpha and PEBP2/CBF, suggesting that it plays an important role in transcriptional activation. We show her...

'\B:,TRAC r· Recently there has been a resurgence of conccrn about islanding of grid-connected photovoltaic (PY) ,ystems rhis condition occurs when the PY system continues to energize a section of the grid after that section has been Isollted from thc main utility voltage source. Generally, islanding is undesirable for a number of reasons, and it is therefore important that PY systems incorpora...

Bath application of dopamine modifies the rhythmic motor pattern generated by the 14 neuron pyloric network in the stomatogastric ganglion of the spiny lobster, Panulirus interruptus. Among other effects, dopamine excites many of the pyloric constrictor (PY) neurons to fire at high frequency and phase-advances the timing of their activity in the motor pattern. These responses arise in part from...

A series of mono-, bis- and trisvinyl-pyridinium triphenylamines (TP-py) has been synthesised and evaluated for its one- and two-photon absorption (2PA) induced-fluorescence properties under biological conditions. Interestingly, these compounds are only weakly fluorescent in water, whereas their fluorescence emissions are strongly restored (exaltation factors of 20-100) upon binding to double-s...

Signaling by growth factor receptor tyrosine kinases is manifest through networks of proteins that are substrates and/or bind to the activated receptors. FGF receptor-3 (FGFR3) is a drug target in a subset of human multiple myelomas (MM) and is mutationally activated in some cervical and colon and many bladder cancers and in certain skeletal dysplasias. To define the FGFR3 network in multiple m...