The structure of a recombinant protein, TyrRS(delta4), corresponding to the anticodon arm binding domain of Bacillus stearothermophilus tyrosyl-tRNA synthetase, has been solved, and its dynamics have been studied by nuclear magnetic resonance (NMR). It is the first structure described for such a domain of a tyrosyl-tRNA synthetase. It consists of a five-stranded beta sheet, packed against two a...

A mutant (Delta5) of Synechocystis sp. strain PCC 6803 constructed by inactivating five inorganic carbon sequestration systems did not take up CO(2) or HCO(3)(-) and was unable to grow in air with or without glucose. The Delta4 mutant in which BicA is the only active inorganic carbon sequestration system showed low activity of HCO(3)(-) uptake and grew under these conditions but more slowly tha...

BACKGROUND In volumetric modulated arc therapy (VMAT), gantry angles, dose rate and the MLC positions vary with the radiation delivery. The quality assurance (QA) system should be able to catch the planning and machine errors. The aim of this study was to investigate the sensitivity of three VMAT QA systems to machine errors. METHODS Several types of potential linac machine errors unique to V...

We report the results of a preclinical evaluation of recently introduced commercial tools for 3D patient IMRT/VMAT dose reconstruction, the Delta4 Anatomy calculation algorithm. Based on the same initial measurement, volumetric dose can be reconstructed in two ways. Three-dimensional dose on the Delta4 phantom can be obtained by renormalizing the planned dose distribution by the measurement val...

The three-dimensional dose (3D) distribution of intensity-modulated radiation therapy (IMRT) was verified based on electronic portal imaging devices (EPIDs), and the results were analyzed. Thirty IMRT plans of different lesions were selected for 3D EPID-based dose verification. The gamma passing rates of the 3D dose verification-based EPID system (Edose, Version 3.01, Raydose, Guangdong, China)...

The Delta(4) diode array phantom (Scandidos, Uppsala, Sweden) was evaluated for verification of segmental intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) on an Elekta linear accelerator (Crawley UK). The device was tested for angular sensitivity by irradiating it from 36 different gantry angles, and the responses of the device to various step-and-shoot s...

The effects of Notch signaling on human megakaryocytic and erythroid differentiation were investigated by exposing human CD34(+) progenitor cells to an immobilized chimeric form of the Notch ligand, Delta-like4 (Dll4Fc). Exposure of human cord blood CD34(+) cells to Dll4Fc induced a modest enhancement of erythroid cell production. Conversely, under megakaryocytic culture conditions, Dll4Fc stro...

In algae, the biosynthesis of docosahexaenoic acid (22:6omega3; DHA) proceeds via the elongation of eicosapentaenoic acid (20:5omega3; EPA) to 22:5omega3, which is required as a substrate for the final Delta4 desaturation. To isolate the elongase specific for this step, we searched expressed sequence tag and genomic databases from the algae Ostreococcus tauri and Thalassiosira pseudonana, from ...

The Delta4 biplanar diode array dosimeter was validated for helical tomotherapy delivery QA. The basic detector characteristics were found to be satisfactory in terms of short-term reproducibility (0.1%), linearity (<0.1%), dose rate dependence (0.4%), and absolute calibration accuracy (0.4% in the center of the phantom compared with the independently calibrated diode). Relative calibration of ...