After anticholinesterase treatment in vivo, depolarization of the postsynaptic muscle fibre membrane by about 4 mV develops due to non-quantally released acetylcholine from the motor nerve terminal. This conclusion was supported by experiments with the curarization of diaphragm slices from anticholinesterase treated mice during intracellular microelectrode recordings.
There are two principal mechanisms of acetylcholine (ACh) release from the resting motor nerve terminal: quantal and non-quantal (NQR); the former being only a small fraction of the total, at least at rest. In the present article we summarize basic research about the NQR that is undoubtedly an important trophic factor during endplate development and in adult neuromuscular contacts. NQR helps to eliminate the polyneural innervation of developing muscle fibers, ensures higher excitability of the adult subsynaptic membrane by surplus polarization and protects the RMP from depolarization by regulating the NO cascade and chloride transport. It shortens the endplate potentials by promoting postsynaptic receptor desensitization when AChE is inhibited during anti-AChE poisoning. In adult synapses, it can also activate the electrogenic Na+/K+-pump, change the degree of synchronization of quanta released by the nerve stimulation and affects the contractility of skeletal muscles., F. Vyskočil, A. I. Malomouzh, E. E. Nikolsky., and Obsahuje seznam literatury
The sinonasal mucosa has an essential role in defense
mechanisms of the upper respiratory tract. The innate immune
system presents the primary defense against noxious
microorganisms followed by induction of the adaptive immune
mechanisms as a consequence of the presence of pathogens.
This well-known activation of adaptive immune system in
response to presence of the antigen on mucosal surfaces is now
broadly applicated in vaccinology research. Prevention of
infectious diseases belongs to substantial challenges in
maintaining the population health. Non-invasive, easily applicable
mucosal vaccination purposes various research opportunities that
could be usable in daily practice. However, the existence of
multiple limitations such as rapid clearance of vaccine from nasal
mucosa by means of mucociliary transport represents a great
challenge in development of safe and efficient vaccines. Here we
give an updated view on nasal functions with focus on nasal
mucosal immunity and its potential application in vaccination in
nearly future.
We shall introduce the class of strongly cancellative multiplicative monoids which contains the class of all totally ordered cancellative monoids and it is contained in the class of all cancellative monoids. If G is a strongly cancellative monoid such that hG ⊆ Gh for each h ∈ G and if R is a ring such that aR ⊆ Ra for each a ∈ R, then the class of all non-singular left R-modules is a cover class if and only if the class of all non-singular left RG-modules is a cover class. These two conditions are also equivalent whenever we replace the strongly cancellative monoid G by the totally ordered cancellative monoid or by the totally ordered group.
Let G be a multiplicative monoid. If RG is a non-singular ring such that the class of all non-singular RG-modules is a cover class, then the class of all non-singular Rmodules is a cover class. These two conditions are equivalent whenever G is a well-ordered cancellative monoid such that for all elements g, h ∈ G with g < h there is l ∈ G such that lg = h. For a totally ordered cancellative monoid the equalities Z(RG) = Z(R)G and σ(RG) = σ(R)G hold, σ being Goldie’s torsion theory.
Non-stationary behavior of departure process in a finite-buffer MX/G/1/K-type queueing model with batch arrivals, in which a threshold-type waking up N-policy is implemented, is studied. According to this policy, after each idle time a new busy period is being started with the Nth message occurrence, where the threshold value N is fixed. Using the analytical approach based on the idea of an embedded Markov chain, integral equations, continuous total probability law, renewal theory and linear algebra, a compact-form representation for the mixed double transform (probability generating function of the Laplace transform) of the probability distribution of the number of messages completely served up to fixed time t is obtained. The considered queueing system has potential applications in modeling nodes of wireless sensor networks (WSNs) with battery saving mechanism based on threshold-type waking up of the radio. An illustrating simulational and numerical study is attached.
The cyclicity index of a matrix is the cyclicity index of its critical subgraph, namely, the subgraph of the adjacency graph which consists of all cycles of the maximal average weight. The cyclicity index of a graph is the least common multiple of the cyclicity indices of all its maximal strongly connected subgraphs, and the cyclicity index of a strongly connected graph is the least common divisor of the lengths of its (directed) cycles. In this paper we obtain the characterization of linear, possibly non-surjective, transformations of tropical matrices preserving the cyclicity index. It appears that non-bijective maps with these properties exist and all maps are exhausted by transposition, renumbering of vertices, Hadamard multiplication with a matrix of a certain special structure, and certain diagonal transformation. Moreover, only diagonal transformation can be non-bijective.