Beneficial Effects of Cocoa in Perivascular Mato Cells of Cerebral Arterioles in SHR-SP (Izm) Rats

As previously reported, the cerebral arterioles are surrounded by unique perivascular Mato cells. They contain many inclusion bodies rich in hydrolytic enzymes, and have strong uptake capacity. They are thus considered scavenger cells of vascular and neural tissues in steady-state. In this study, employing hypertensive SHR-SP (Izm) rats, the viability of Mato cells was investigated. In hypertensive rats, the capacity for uptake of horse radish peroxidase (HRP) and the activity of acid phosphatase (ACPase) of Mato cells were markedly reduced, and on electron-microscopic examination Mato cells were found to include heterogeneous contents and appeared electron-dense and degenerated. Vascular cells exhibited some signs of pathology. However, in hypertensive rats fed chow containing 0.25% cocoa, the uptake capacity and ACPase activity of Mato cells for HRP were enhanced, and on electron-microscopic examination Mato cells appeared healthy, with mitochondria with nearly normal profiles. Signs of pathology in vascular cells were also decreased. Superoxides may impair Mato cells and vascular cells

Effect of particle shape on hydrocyclone classification

Influence of particle shape on hydrocyclone classification was investigated. Classification tests using hydrocyclone and cyclosizer showed that coarse fractions of plate-like particles such as PTFE and glass flake used here were not necessarily recovered as underflow product, especially at relatively high inlet velocity. Settling velocity of the glass flake particles in centrifugal field was estimated using a centrifugal particle size analyzer, and it was revealed that differences in settling velocity between coarse and fine glass flake particles became smaller with increases in angular velocity. Moreover, settling test of glass plate in water or glycerin solution was conducted to know relationship between particle Reynolds number (Re) and settling velocity of the plate. At smaller Re condition, the glass plate settled straight and stably, and larger plate settled faster than smaller plate. However, oscillating motion of the plate occurred in the region of high Re, and settling velocities of the large plate became smaller than that of the small plate in such conditions. Drag coefficient (C) calculated based on the settling velocity of the glass plate is similar to that of glass spheres below Re of about 50, above which it became larger than that of glass sphere. Approximation formula of correlaton between Re and C suggests that the influence of the Re on C can be neglected in the region of high Re, and C increases with increases in the ratio of the particle diameter to thickness (D/T). The decrease of the difference in settling velocity recognized in the centrifugal settling test and the effect of the particle shape (D/T) on C at high Re region are considered to be able to affect the hydrocyclone classification. The misplacement of coarse plate-like particles in the hydrocyclone and cyclosizer tests could be ascribed to the particle shape effects

Resampling Nucleotide Sequences with Closest-Neighbor Trimming and Its Comparison to Other Methods

A large number of nucleotide sequences of various pathogens are available in public databases. The growth of the datasets has resulted in an enormous increase in computational costs. Moreover, due to differences in surveillance activities, the number of sequences found in databases varies from one country to another and from year to year. Therefore, it is important to study resampling methods to reduce the sampling bias. A novel algorithm-called the closest-neighbor trimming method-that resamples a given number of sequences from a large nucleotide sequence dataset was proposed. The performance of the proposed algorithm was compared with other algorithms by using the nucleotide sequences of human H3N2 influenza viruses. We compared the closest-neighbor trimming method with the naive hierarchical clustering algorithm and k-medoids clustering algorithm. Genetic information accumulated in public databases contains sampling bias. The closest-neighbor trimming method can thin out densely sampled sequences from a given dataset. Since nucleotide sequences are among the most widely used materials for life sciences, we anticipate that our algorithm to various datasets will result in reducing sampling bias