Common Structural Patterns in the Maxicircle Divergent Region of Trypanosomatidae

Maxicircles of all kinetoplastid flagellates are functional analogs of mitochondrial genome of other eukaryotes. They consist of two distinct parts, called the coding region and the divergent region (DR). The DR is composed of highly repetitive sequences and, as such, remains the least explored segment of a trypanosomatid genome. It is extremely difficult to sequence and assemble, that is why very few full length maxicircle sequences were available until now. Using PacBio data, we assembled 17 complete maxicircles from different species of trypanosomatids. Here we present their large-scale comparative analysis and describe common patterns of DR organization in trypanosomatids.

Hydrodynamic lubrication of partial textured sliding journal bearing based on three-dimensional CFD

Purpose – The purpose of this study is to investigate the effects of partial texture location and dimple depth on load carrying capacity (LCC), friction coefficient and circumferential flow of journal bearing. Design/methodology/approach – Based on the Navier-Stokes equation, the methodology used computational fluid dynamics (CFD). A phase change boundary condition was applied on fluid domain, and the negative pressure at divergent region of oil film was considered. Findings – It has been found that texture located at lubricant inlet area can improve the performance of the bearing, and the effect of shallow dimples is superior to the deep ones. However, the bearing performance will be reduced due to the texture located at the maximum pressure area. When texture is located at the lubricant outlet area, there will be two different situations: the part of the texture located within the oil film divergent area can improve the LCC, while the part that is beyond the divergent region will make the LCC decrease. Originality/value – The lower-half oil film model was established only in this study to analyze the hydrodynamic lubrication performance of partial textured journal bearing, and the lower-half oil film was divided into three parts. A new cavitation algorithm was introduced to deal with the negative pressure. The formula for calculating the friction of liquid film is refined, including the consideration of vapor phase. The simulation results show that the location of partial texture have a great influence on the bearing performance.