The adult human brain represents only 2 % of the body's total weight, however it is one of the most metabolically active organs in the mammalian body. Its high metabolic activity necessitates an efficacious waste clearance system. Besides the blood, there are two fluids closely linked to the brain and spinal cord drainage system: interstitial fluid (ISF) and cerebrospinal fluid (CSF). The aim of this review is to summarize the latest research clarifying the channels of metabolite removal by fluids from brain tissue, subarachnoid space (SAS) and brain dura (BD). Special attention is focused on lymphatic vascular structures in the brain dura, their localizations within the meninges, morphological properties and topographic anatomy. The review ends with an account of the consequences of brain lymphatic drainage failure. Knowledge of the physiological state of the clearance system is crucial in order to understand the changes related to impaired brain drainage.
Optimisation of water treatment conditions with usage of aluminium sulphate and ferric sulphate was made with raw water containing high concentrations of natural aluminium. For optimisation of coagulation conditions here were used the jar tests. The efficiency of aggregation was evaluated with the help of the degree and test of aggregation. In all water samples used, the total aluminium concentration was fractionated into nine forms. The high values of degree of aggregation and high portion of macro-, micro-, and primary particles were attained in optimally treated water samples using both types of coagulants. It contrasts to the portion of nonaggregated particles ranging in optimal treated water only from 3% to 7%. Fractionation of total aluminium proved that the removal efficiency of all Al fractions is very good. and V této práci byly optimalizovány podmínky úpravy vod s přirozeně zvýšeným obsahem hliníku. K optimalizačním testům byla použita sklenicová zkouška. Výsledky byly hodnoceny pomocí testů agregace a stupně agregace. Dále byly u všech vzorků surových i upravených vod provedeny frakcionace celkového hliníku. Výsledky ukázaly, že při optimálních dávkách obou použitých koagulačních činidel je dosahováno vysoké účinnosti agregace. V upravené vodě byly nejvíce zastoupeny mikročástice, makročástice a primární částice hliníku, naopak neagregovaný podíl koagulačního činidla tvořil pouze 3 až 7 %. Při použití obou koagulačních činidel byla zjištěna vysoká účinnost odstranění jednotlivých frakcí hliníku.
It is shown that pseudo BL-algebras are categorically equivalent to certain bounded DRl-monoids. Using this result, we obtain some properties of pseudo BL-algebras, in particular, we can characterize congruence kernels by means of normal filters. Further, we deal with representable pseudo BL-algebras and, in conclusion, we prove that they form a variety.
For a finite commutative ring $R$ and a positive integer $k\geqslant 2$, we construct an iteration digraph $G(R, k)$ whose vertex set is $R$ and for which there is a directed edge from $a\in R$ to $b\in R$ if $b=a^k$. Let $R=R_1\oplus \ldots \oplus R_s$, where $s>1$ and $R_i$ is a finite commutative local ring for $i\in \{1, \ldots , s\}$. Let $N$ be a subset of $\{R_1, \dots , R_s\}$ (it is possible that $N$ is the empty set $\emptyset $). We define the fundamental constituents $G_N^*(R, k)$ of $G(R, k)$ induced by the vertices which are of the form $\{(a_1, \dots , a_s)\in R\colon a_i\in {\rm D}(R_i)$ if $R_i\in N$, otherwise $a_i\in {\rm U}(R_i), i=1,\ldots ,s\},$ where U$(R)$ denotes the unit group of $R$ and D$(R)$ denotes the zero-divisor set of $R$. We investigate the structure of $G_N^*(R, k)$ and state some conditions for the trees attached to cycle vertices in distinct fundamental constituents to be isomorphic.