The antifolate LY309887 is a specific glycinamide ribonucleotide formyltransferase inhibitor that blocks de novo purine synthesis and produces a depletion of purine nucleotides. The activity of LY309887 in six human tumor cell lines has been examined by growth inhibition and clonogenic assay after continuous exposure for three cell doubling times and by ATP depletion at 24 h. Three cell lines (...

The signal recognition particle (SRP) from Escherichia coli, composed of Ffh protein and 4.5S RNA, mediates membrane targeting of translating ribosomes displaying a signal or signal-anchor sequence. SRP binds at the peptide exit of the large ribosomal subunit. Structural details of the interaction are not known. Here, the position of Ffh or SRP on the ribosome was probed by using site-specific ...

Mammalian cardiac muscle contains two myosin alkali light chains which are the major isoforms present in either atrial (MLC1A) or ventricular (MLC1V) muscle, and which are different from the fast skeletal muscle isoforms (MLC1F and MLC3F). The atrial isoform is also expressed in fetal skeletal and fetal ventricular muscle, where this isoform is also described as the fetal isoform MLC1emb. We ha...

The association of ribosomal proteins with carcinogenesis of nasopharyngeal carcinoma (NPC) has been established in a limited subset of ribosomal protein genes. To date, three ribosomal protein genes, eL27 (L27), eL41 (L41), and eL43 (L37a), have been found to be differentially expressed in cell lines derived from NPC tumors. This raises the possibility of more ribosomal protein genes that coul...

BACKGROUND Although well-acknowledged in vivo, spontaneous death of cancer cells in vitro is less widely appreciated. MATERIALS AND METHODS Colony formation was studied in untreated control plates of standard clonogenic assays and measurements of actual and potential doubling times performed in asynchronous cultures of human cancer cells lines. Western blotting of lung large cell carcinoma, C...

How does rural-urban migration shape urban production in developing countries? We use longitudinal data on Chinese manufacturing firms between 2000 and 2006, exploit exogenous variation induced by agricultural income shocks for identification. find that, when immigration increases, becomes more labor intensive productivity declines. investigate the reorganization of using patent applications pr...

Many companies survey employees about their managers yet it is unclear whether this information is, or should be used to evaluate and compensate managers. Data from a high-tech firm reveals that survey measures are associated with employees’ lower attrition, higher promotions, higher salary increases, and higher engagement, but have only a limited relation to subjective performance scores. The ...

We report the observation and the theoretical explanation of the parametric down-conversion nonlinear susceptibility at the K-absorption edge of diamond and at the L23-absorption edge of a silicon crystal. Using arguments similar to those invoked to successfully predict resonant inelastic x-ray spectra, we derive an expression for the renormalization term of the nonlinear susceptibility at the ...

We document the evolution of productivity in a steel mini mill with fixed capital, producing an unchanged product with Leontief technology working 24/7. Despite—almost—unchanged production conditions, output doubled within the sample period (12 years). We decompose the gains into downtime reductions, more rounds of production per time, and more output per run. After attributing productivity gai...