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41.
George L. Wied Peter H. Bartels Marluce Bibbo May Chen Frank R. Reale Hans Schreiber Jaroslav J. Sychra 《Cell biochemistry and biophysics》1979,1(1):39-54
Cytologic preparations made from the tracheobronchial tree taken by the Schreiber catheter have been scanned by three color
microphotometry. The digitized cell images were processed by the analytical cytodiagnostic programs of the TICAS system. Cells
were sorted into two control groups and five groups of increasing atypia ranging from normal epithelium to invasive squamous
cell carcinoma. Standard statistical tests, including Wilk's Lambda, Rao's V, and the Kruskal-Wallis tests are performed on
these subsets of cell image features. This study demonstrates that discriminant analyses permit differentiation between normal
cells and those from marked atypia or carcinoma and that the classification achieves a high degree of agreement with visual
assignment. 相似文献
42.
Simultaneous and stepwise deprotection of the fully benzylated D-glucosyl esters of 1-benzyl N-benzyloxycarbonyl- and N-tert-butyloxycarbonyl-L-glutamic acid (1 and 5, respectively) have been examined. Catalytic hydrogenation of 1 led to intramolecular aminolysis to give pyroglutamic acid and D-glucose, but similar treatment in the presence of trifluoroacetic acid afforded both anomers of 1-O-(L-gamma-glutamyl)-D-glucopyranose, which were characterized as trifluoroacetates (2alpha and 2beta) and converted into 2,3,4,6-tetra-O-acetyl-1-O-[1-methyl N-(acetyl)-L-glutam-5-oyl]-D-glucopyranose (4) which was also prepared by a definitive method. Hydrogenolysis of 5 gave both anomers of 1-O-[N-(tert-butyloxycarbonyl)-L-gamma-glutamyl]-D-glucopyranose (6), which, upon treatment with trifluoroacetic acid at - 10 degrees, afforded 2alpha and 2beta, respectively. The structure of 6beta was established by its conversion into 2,3,4,6-tetra-O-acetyl-1-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-beta-D-glucopyranose (7beta), whereas similar treatment of 6alpha gave a mixture of 1,3,4,6-tetra-O-acetyl-2-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-alpha-D-glucopyranose (9) and 7alpha. A 1 leads to 2 acyl migration occurred during esterification of the aglycon carboxyl group of 6alpha with diazomethane to give 2-O-[1-methyl N-(tert-butyloxycarbonyl)-L-glutam-5-oyl]-alpha-D-glucopyranose (8). 相似文献
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Marek Glombik Dario Copetti Jan Bartos Stepan Stoces Zbigniew Zwierzykowski Tom Ruttink Jonathan F. Wendel Martin Duchoslav Jaroslav Dolezel Bruno Studer David Kopecky 《The Plant journal : for cell and molecular biology》2021,107(4):1166-1182
Allopolyploidization entailing the merger of two distinct genomes in a single hybrid organism, is an important process in plant evolution and a valuable tool in breeding programs. Newly established hybrids often experience massive genomic perturbations, including karyotype reshuffling and gene expression modifications. These phenomena may be asymmetric with respect to the two progenitors, with one of the parental genomes being “dominant.” Such “genome dominance” can manifest in several ways, including biased homoeolog gene expression and expression level dominance. Here we employed a k-mer–based approach to study gene expression in reciprocal Festuca pratensis Huds. × Lolium multiflorum Lam. allopolyploid grasses. Our study revealed significantly more genes where expression mimicked that of the Lolium parent compared with the Festuca parent. This genome dominance was heritable to successive generation and its direction was only slightly modified by environmental conditions and plant age. Our results suggest that Lolium genome dominance was at least partially caused by its more efficient trans-acting gene expression regulatory factors. Unraveling the mechanisms responsible for propagation of parent-specific traits in hybrid crops contributes to our understanding of allopolyploid genome evolution and opens a way to targeted breeding strategies. 相似文献
45.
Dagmara Sirov Veronika Kreidlov Lubomír Adamec Jaroslav Vrba 《The Journal of eukaryotic microbiology》2020,67(5):608-611
The host specificity of the recently described ciliate species Tetrahymena utriculariae was tested in a greenhouse growth experiment, which included 14 different species of aquatic Utricularia as potential host plants. We confirmed the high specificity of the interaction between U. reflexa and T. utriculariae, the former being the only tested host species able to maintain colonization for prolonged time periods. We conclude that this plant–microbe relationship is a unique and specialized form of digestive mutualism and the plant–microbe unit a suitable experimental system for future ecophysiological studies. 相似文献
46.
Tomáš Fiala Jaroslav Holuša Jiří Procházka Lukáš Čížek Marek Dzurenko Jiří Foit Juraj Galko Josef Kašák Jan Kulfan Ferenc Lakatos Oto Nakládal Jiří Schlaghamerský Michal Svatoš Jiří Trombik Petr Zábranský Peter Zach Emanuel Kula 《Journal of Applied Entomology》2020,144(6):423-433
Invasive organisms represent great threats to ecosystems and great challenges to forest management. In Europe, the black timber bark beetle (Xylosandrus germanus) is an invasive secondary pest that mostly attacks the logs of felled trees. We showed the invasion history for Europe and using many local surveys, we summarize the current distribution and other available information on X. germanus in the Czech Republic. We report that this species is distributed from the lowlands to the mountains in the Czech Republic; it is widespread in the eastern half of the country, where it is more abundant in the warmer south and southeast areas than in the cooler areas. Most (78%) of the known localities are at elevation below 400 m a.s.l. Although an ice storm greatly increased X. germanus abundance near the border with Austria, its high abundance did not result in damage to standing trees. Presence of X. germanus in the Czech Republic for over 10 years has not led to heavy tree infestation. 相似文献
47.
Francová Kateřina Šumberová Kateřina Kučerová Andrea Šorf Michal Grill Stanislav Exler Norbert Vrba Jaroslav 《Wetlands Ecology and Management》2021,29(1):93-110
Wetlands Ecology and Management - Plants play an important role in fishpond littorals, but little is known about factors influencing their presence and growth patterns. We surveyed vegetation of... 相似文献
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Lubomir Prochazka Stepan Koudelka Lan-Feng Dong Jan Stursa Jacob Goodwin Jiri Neca Josef Slavik Miroslav Ciganek Josef Masek Katarina Kluckova Maria Nguyen Jaroslav Turanek Jiri Neuzil 《Apoptosis : an international journal on programmed cell death》2013,18(3):286-299
α-Tocopheryl succinate (α-TOS) is a promising anti-cancer agent due to its selectivity for cancer cells. It is important to understand whether long-term exposure of tumour cells to the agent will render them resistant to the treatment. Exposure of the non-small cell lung carcinoma H1299 cells to escalating doses of α-TOS made them resistant to the agent due to the upregulation of the ABCA1 protein, which caused its efflux. Full susceptibility of the cells to α-TOS was restored by knocking down the ABCA1 protein. Similar resistance including ABCA1 gene upregulation was observed in the A549 lung cancer cells exposed to α-TOS. The resistance of the cells to α-TOS was overcome by its mitochondrially targeted analogue, MitoVES, that is taken up on the basis of the membrane potential, bypassing the enhanced expression of the ABCA1 protein. The in vitro results were replicated in mouse models of tumours derived from parental and resistant H1299 cells. We conclude that long-term exposure of cancer cells to α-TOS causes their resistance to the drug, which can be overcome by its mitochondrially targeted counterpart. This finding should be taken into consideration when planning clinical trials with vitamin E analogues. 相似文献