Computational Fluid Dynamics Study of Bifurcation Aneurysms Treated with Pipeline Embolization Device: Side Branch Diameter Study.

An intracranial aneurysm, abnormal swelling of the cerebral artery, may lead to undesirable rates of mortality and morbidity upon rupture. Endovascular treatment involves the deployment of a flow-diverting stent that covers the aneurysm orifice, thereby reducing the blood flow into the aneurysm and mitigating the risk of rupture. In this study, computational fluid dynamics analysis is performed on a bifurcation model to investigate the change in hemodynamics with various side branch diameters. The condition after the deployment of a pipeline embolization device is also simulated. Hemodynamic factors such as flow velocity, pressure, and wall shear stress are studied. Aneurysms with a larger side branch vessel might have greater risk after treatment in terms of hemodynamics. Although a stent could lead to flow reduction entering the aneurysm, it would drastically alter the flow rate inside the side branch vessel. This may result in side-branch hypoperfusion subsequent to stenting. In addition, two patient-specific bifurcation aneurysms are tested, and the results show good agreement with the idealized models. Furthermore, the peripheral resistance of downstream vessels is investigated by varying the outlet pressure conditions. This quantitative analysis can assist in treatment planning and therapeutic decision-making.

Complete mitochondrial genome of Costaria costata shows conservative evolution in Laminariales.

Costaria costata, with great commercial and industrial value, typically grows in low intertidal and subtidal retgions in East Asia. The complete mitochondrial genome of C. costata is determined as circular-mapping and AT-rich (65%). The 37,461 bp mitochondrial genome consists of 25 tRNAs, 38 genes (including ORFs) and 3 ribosome genes. The gene arrangement and component are identical to those of Laminaria mitochondrial genomes, which show highly conservative evolution in mitochondrial genomes within the Laminariales. Moreover, the C. costata mitogenome makes full use of nucleotide and genetic information by large amounts of gene overlappings for better adapting the evolution of small genomes.

Complete mitochondrial genome of Undaria pinnatifida (Alariaceae, Laminariales, Phaeophyceae).

Undaria pinnatifida is one of the most important economic marine algae and key components of coastal ecosystems. Undaria pinnatifida owns a typical heteromorphic, diplohaplontic life cycle. We present the complete sequence of mitochondrial genome of U. pinnatifida, focusing on genome organization and phylogenetic relationship between different brown algae lineages. The size of U. pinnatifida mitochondrial DNA is 37,402 bp, including 3 rRNAs, 25 tRNAs, 35 proteins, as well as 3 ORFs. No intron is found and most genes are encoded on the H-strand. The phylogenetic trees (BI) constructed on 35 protein-coding genes from 17 species proved that Saccharina has a closer relationship with Laminaria than that with Undaria. The results supported the conclusion that Alariaceae is sister genus to the Laminariaceae. Above researches will facilitate the understanding of evolutionary relationship within brown algae.