Number of results to display per page
Search Results
17762. Possibilities of cyclization of side alkyl chains of n-alkylphenols and n-alkylbenzenes in the environment of a stationary phase
- Creator:
- Pavel Straka, Petr Buryan, and Jana Tomanová
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Geologie. Meteorologie. Klimatologie, geochemie, alkylphenols, alkylbenzenes, non-covalent interactions, van der Waals forces, retention times, 7, and 551
- Language:
- English
- Description:
- During separations in both polar and nonpolar stationary phases of gas chromatographic columns, side alkylchains of n-alkylphenols and n-alkylbenzenes become cyclized. In the aromatic-quasi-alicyclic molecules that are thereby formed, the effect of van der Waals forces is thus increased. The increase involves not only intramolecularly but also intermolecularly acting effects and becomes significantly evident when propyl and higher substituents as butyl, pentyl and hexyl constitute the side alkyl chains. As a result, boiling points considerably increase (non-linearly) in the case of n-alkylphenols and n-alkylbenzenes with total number of carbons in the molecule higher than 9. This leads to divergence in the retention characteristics of the above-mentioned compounds, which can be observed in the dependence of relative retention times on the number of carbons. Cyclization of side alkyl chains in a stationary phase is a quite new phenomenon., Pavel Straka, Petr Buryan and Jana Náhunková., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17763. Possibilities of introduction of subsidiary prosecution in Czech criminal proceedings
- Creator:
- Mulák, Jiří
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- poškozený v trestním řízení, aggrieved party, subsidiary prosecution, right to efficient investigation, accusatorial principle, 16, and 34
- Language:
- English
- Description:
- This paper deals with subsidiary prosecution, which is an institute that is not known to the current Czech criminal trial, but its legislative embedment is considered in the future. Attention is paid in this context, among other things, to criminal-law relations, which are applied through criminal-trial relations, and to the right to efficient investigation which the aggrieved party (victim of the crime) has in relation to the state. The author admits, under certain conditions, the existence of subsidiary prosecution because it is a suitable form of how to check the principle of legality, as well as a suitable instrument against misuse of discretionary powers of the public prosecutor (in the systems built upon the principle of opportunity)., Jiří Mulák., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
17764. Possibility of acetylcholinesterase overexpression in Alzheimer disease patients after therapy with acetylcholinesterase inhibitors
- Creator:
- Kračmarová, Alžběta, Drtinová, Lucie, and Pohanka, Miroslav
- Format:
- print, text, and regular print
- Type:
- model:article, article, Text, časopisecké články, přehledy, and TEXT
- Subject:
- acetylcholin--metabolismus, acetylcholinesteráza--metabolismus, Alzheimerova nemoc--farmakoterapie--metabolismus, centrální nervový systém--účinky léků--metabolismus, inhibitory cholinesteráz--farmakologie, monitorování léků--metody, enzymatické testy, lidé, nootropní látky--farmakologie, and nervový přenos--účinky léků
- Language:
- English
- Description:
- Acetylcholinesterase is an enzyme responsible for termination of excitatory transmission at cholinergic synapses by the hydrolyzing of a neurotransmitter acetylcholine. Nowadays, other functions of acetylcholinesterase in the organism are considered, for example its role in regulation of apoptosis. Cholinergic nervous system as well as acetylcholinesterase activity is closely related to pathogenesis of Alzheimer disease. The mostly used therapy of Alzheimer disease is based on enhancing cholinergic function using inhibitors of acetylcholinesterase like rivastigmine, donepezil or galantamine. These drugs can influence not only the acetylcholinesterase activity but also other processes in treated organism. The paper is aimed mainly on possibility of increased expression and protein level of acetylcholinesterase caused by the therapy with acetylcholinesterase inhibitors. and A. Kračmarová, L. Drtinová, M. Pohanka
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
17765. Possible intracellular regulators of female sexual maturation
- Creator:
- Kolesarova, A., Alexander V. Sirotkin, Mellen, M., and Roychoudhury, S.
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, vaječníky, kinázy, apoptóza, ovaries, kinases, apoptosis, transcription factor, 14, and 612
- Language:
- English
- Description:
- Protein kinases, transcription factors and other apoptosis- and proliferation-related proteins can regulate reproduction, but their involvement in sexual maturation remains to be elucidated. The general aim of the in vivo and in vitro experiments with porcine ovarian granulosa cells was to identify possible intracellular regulators of female sexual maturation. For this purpose, proliferation (expression of proliferating cell nuclear antigen - PCNA, mitogen-activated protein kinases - ERK 1,2 related MAPK and cyclin B1), apoptosis (expression of the apoptotic protein Bax and apoptosis regulator Bcl-2 protein), expression of some protein kinases (cAMP dependent protein kinase - PKA, cGMPdependent protein kinase - PKG, tyrosine kinase - TK) and cAMP responsive element binding protein 1 (CREB-1) was examined in granulosa cells isolated from ovaries of immature and mature gilts. Expression of PCNA, ERK1,2 related MAPK, cyclin B1, Bcl-2, Bax, PKA, CREB-1, TK and PKG in porcine granulosa cells were detected by immunocytochemistry. Sexual maturation was associated with significant increase in the expression of Bcl-2, Bax, PKA, CREB-1 and TK and with decrease in the expression of ERK1,2 related MAPK, cyclin B1 and PKG in granulosa cells. No significant difference in PCNA expression was noted. The present data obtained from in vitro study indicate that sexual maturation in females is influenced by puberty-related changes in porcine ovarian signaling substances: increase in Bcl-2, Bax, PKA, CREB-1, TK and decrease in ERK1,2 related MAPK, cyclin B1 and PKG. It suggests that these signaling molecules could be potential regulators of porcine sexual maturation., A. Kolesarova, A. V. Sirotkin, M. Mellen, S. Roychoudhury., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17766. Possible pathogenetic mechanisms and new therapeutic approaches of pes equinovarus
- Creator:
- Miroslav Ošťádal, Lišková, J., Hadraba, D., and Adam Eckhardt
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, pes equinovarus, clubfoot, pathogenetic mechanisms, fibrosis, 14, and 612
- Language:
- English
- Description:
- Idiopathic pes equinovarus (clubfoot) is a congenital deformity of the foot and lower leg defined as a fixation of the foot in plantar flexion, adduction, supination and varus. The deformity does not affect only the foot position, which is usually investigated by radiography, CT, micro-CT, MRI or ultrasound but logically influence the whole gait biomechanics. It is supposed, that clubfoot belongs to a group of fibroproliferative disorders whose origin and multi- hierarchical effect remain unknown. It has been suggested that fibroblasts and growth factors may be involved. To gain a more global view, direct analysis of the protein composition of extra cellular matrix, a proteomic approach was used. At present two principle methods are mostly used for the treatment of clubfoot: physiotherapy and the Ponseti method. The determination of the general biological and biomechanical parameters for various regio ns of the clubfoot can potentially help in the understanding of the mechanisms participating on this serious anomaly and thus contribute to the development of the more efficient therapeutic approach. This review summarizes the present knowledge on the poss ible pathogenetic mechanisms participating in the development of the clubfoot and their possible relation to the new therapeutic approaches., M. Ošťádal, J. Lišková, D. Hadraba, A. Eckhardt., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
17767. Possible role of flavin components of protochlorophyllide-protein complexes in primary processes of protochlorophyllide photoreduction in etiolated plant leaves
- Creator:
- Ignatov, N.V., Belyaeva, O.B., and Litvin, F.F.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Using fluorescence methods, it was shown that the energy transfer from flavin to protochlorophyilide (PChlide) 655/650 and to the products of its photoconversion (chlorophyllide) couid be observed up to the completion of the Shibata shift. The changes in fluorescence spectra of NADPH and flavins, accompanying the PChlide 655/650 photoreduction at 77 K, allow to assume the participation of NADPH and flavins in the primary photoreactions of chlorophyllide formation.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17768. Possible Role of Matrix Metalloproteinases in Reconstruction of Peripheral Pulmonary Arteries Induced by Hypoxia
- Creator:
- Jana Novotná and Jan Herget
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie člověka, human physiology, Chronic hypoxia, Hypoxic pulmonary hypertension, Vascular remodeling, Collagen, Metalloproteinases, 14, and 612
- Language:
- English
- Description:
- Exposure to chronic hypoxia results in hypoxic pulmonary hypertension characterized by structural remodeling of peripheral pulmonary vasculature. An important part of this remodeling is an increase of collagen turnover and deposition of newly formed collagen fibrils in the vascular walls. The activity of collagenolytic metalloproteinases in the lung tissue is notably increased in the first days of exposure to hypoxia. The increased collagenolytic activity results in the appearance of collagen cleavages, which may be implied in the triggering of mesenchymal proliferation in peripheral pulmonary arteries. We hypothesize that radical injury to pulmonary vascular walls is involved in collagenolytic metalloproteinase activation., J. Novotná, J. Herget., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17769. Post scriptum k příspěvku Petra Skalníka
- Creator:
- Hanzl, Zdeněk
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17770. Post-cyclic transmission in Pomphorhynchus laevis (Acanthocephala)
- Creator:
- Kennedy, Clive R.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- transmission, post-cyclic, and Pomphorhynchus laevis
- Language:
- English
- Description:
- A series of laboratory experiments was conducted to investigate the possibility of post-cyclic transmission in Pomphorhynchus laevis (Muller, 1776). Rainbow trout Oncorhynchus mykiss (Walbaum) were exposed to P. laevis in naturally infected Coitus gobio Linnaeus, Noemacheiius barhalulus (Linnaeus), Phoxinus phoxinus (Linnaeus) and heuciscus cephalus (Linnaeus) and sacrificed one month alter infection. Post-cyclic transmission was possible from all four species even though they came from three families and differed in respect of their status and suitability as hosts of P. laevis. There was no selection for or against cither sex of P. laevis, parasites grew in the rainbows and they occupied the same, normal site in the intestine of rainbows irrespective of source host. Post-cyclic transmission of gravid parasites could occur from C. gobio but not from L. cephalus. It is believed that this failure to transmit larger parasites of either sex reflects the age and so development of the proboscis bulb of P. laevis and the extent of the host encapsulation response rather than size or stage of maturity per se. Post-cyclic transmission has the potential to be important in nature.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public