Bifunctional pyrimidine deaminase/reductase (RibD) plays an important role during riboflavin biosynthesis in many microorganisms. The 40.4 kDa RibD from Shigella flexneri 2a has been cloned, expressed, purified and characterized. Three Crystals of RibD have been obtained by the hanging-drop technique at 291 K using PEG 20k or NaCl as precipitant. The RibD crystal using PEG 20k as precipitant di...

Y. H. Liu, J. C. Zuo, X. F. Ren, College of Material Science and Engineering, Shenyang Ligong University, Shenyang,Liaoning, China. L. YONG, School of Material and Metallurgy, Northeastern University, Liaoning, Liaoning, China In this paper cerium oxide (CeO2) nanoparticles with 200-300 nm in diameter were synthesized via a precipitation method using ammonia water and oxalic acid as precipitant...

Asphaltene precipitation is traditionally modeled using polymer solution theories or cubic equations of state. We propose another approach based on artificial neural network technique to model onset of precipitation of dissolved asphaltene in the solution of solvent + precipitant. A mathematical model based on feed-forward artificial neural network technique, which takes advantage of a modified...

Suitable conditions for protein crystallization are commonly identified by screening combinations of independent factors that affect crystal formation. Because precipitating agents are prime determinants of crystallization, we investigated whether a systematic exploration of combinations of mechanistically distinct precipitants would enhance crystallization. A crystallization screen containing ...

Lipocalin-type prostaglandin (PG) D synthase (L-PGDS) catalyzes the isomerization of PGH(2) to PGD(2) and is involved in the regulation of pain and of nonrapid eye movement sleep and the differentiation of male genital organs and adipocytes, etc. L-PGDS is secreted into various body fluids and binds various lipophilic compounds with high affinities, acting also as an extracellular transporter. ...

Nucleation of protein crystals has been shown to be facilitated by substrates decorated with both nanoto micro-scale hierarchical undulations and spatially varying surface potential. In fact, on such surfaces, several proteins were found to crystallize without having to use any precipitant in contrast to all other homogeneous and heterogeneous systems in which precipitant is an essential ingred...

Heart failure (HF) patients have frequent exacerbations leading to high consumption of medical services and recurrent hospitalizations.Different precipitating factors have various effects on long-term survival.We investigated 2212 patients hospitalized with a diagnosis of either acute HF or acute exacerbation of chronic HF. Patients were divided into 2 primary precipitant groups: ischemic (N = ...