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991.
Michael addition of 1,2:3,4-di-O-isopropylidene-6-thio-alpha-D-galactose (2) to 2-propyl 6-O-acetyl-3,4-dideoxy-alpha-D-glycero-hex-3-enopyranosid-2-ulose (1) afforded, as the major diastereoisomer, 2-propyl 6-O-acetyl-3-deoxy-4-S-(6-deoxy-1,2:3,4-di-O-isopropylidene-alpha-D-galactopyranos-6-yl)-4-thio-alpha-D-threo-hexopyranosid-2-ulose (3, 91% yield). Reduction of the carbonyl group of 3, followed by O-deacetylation gave the two epimers 7 (alpha-D-lyxo) and 8 (alpha-D-xylo) in a 1:2 ratio. On removal of the protecting groups of 8 by acid hydrolysis, formation of an 1,6-anhydro bridge was observed in the 3-deoxy-4-thiohexopyranose unit (10). The free non-glycosidic thioether-linked disaccharide 3-deoxy-4-S-(6-deoxy-alpha,beta-D-galactopyranos-6-yl)-4-thio-alpha,beta-D-xylo-hexopyranose (11) was obtained by acetolysis of 10 followed by O-deacetylation. A similar sequence starting from the enone 1 and methyl 2,3,4-tri-O-benzoyl-6-thio-alpha-D-glucopyranoside (12) led successfully to 2-propyl 3-deoxy-4-S-(methyl 6-deoxy-alpha-D-glucopyranos-6-yl)-4-thio-alpha-D-lyxo-hexopyranoside (17) and its alpha-D-xylo analog (19, major product). In this synthetic route, orthogonal sets of protecting groups were employed to preserve the configuration of both reducing ends and to avoid the formation of the 1,6-anhydro ring. 相似文献
992.
993.
DC Andrade C Henriquez–Olguín AR Beltrán MA Ramírez C Labarca M Cornejo C álvarez R Ramírez-Campillo 《Biology of sport / Institute of Sport》2015,32(2):123-128
The purpose of this study was to compare the acute effects of general, specific and combined warm-up (WU) on explosive performance. Healthy male (n = 10) subjects participated in six WU protocols in a crossover randomized study design. Protocols were: passive rest (PR; 15 min of passive rest), running (Run; 5 min of running at 70% of maximum heart rate), stretching (STR; 5 min of static stretching exercise), jumping [Jump; 5 min of jumping exercises – 3x8 countermovement jumps (CMJ) and 3x8 drop jumps from 60 cm (DJ60)], and combined (COM; protocols Run+STR+Jump combined). Immediately before and after each WU, subjects were assessed for explosive concentric-only (i.e. squat jump – SJ), slow stretch-shortening cycle (i.e. CMJ), fast stretch-shortening cycle (i.e. DJ60) and contact time (CT) muscle performance. PR significantly reduced SJ performance (p =0.007). Run increased SJ (p =0.0001) and CMJ (p =0.002). STR increased CMJ (p =0.048). Specific WU (i.e. Jump) increased SJ (p =0.001), CMJ (p =0.028) and DJ60 (p =0.006) performance. COM increased CMJ performance (p =0.006). Jump was superior in SJ performance vs. PR (p =0.001). Jump reduced (p =0.03) CT in DJ60. In conclusion, general, specific and combined WU increase slow stretch-shortening cycle (SSC) muscle performance, but only specific WU increases fast SSC muscle performance. Therefore, to increase fast SSC performance, specific fast SSC muscle actions must be included during the WU. 相似文献
994.
Julie Earl Daniel Rico Enrique Carrillo-de-Santa-Pau Benjamín Rodríguez-Santiago Marinela Méndez-Pertuz Herbert Auer Gonzalo Gómez Herbert Barton Grossman David G Pisano Wolfgang A Schulz Luis A Pérez-Jurado Alfredo Carrato Dan Theodorescu Stephen Chanock Alfonso Valencia Francisco X Real 《BMC genomics》2015,16(1)
Background
Urothelial bladder cancer is a highly heterogeneous disease. Cancer cell lines are useful tools for its study. This is a comprehensive genomic characterization of 40 urothelial bladder carcinoma (UBC) cell lines including information on origin, mutation status of genes implicated in bladder cancer (FGFR3, PIK3CA, TP53, and RAS), copy number alterations assessed using high density SNP arrays, uniparental disomy (UPD) events, and gene expression.Results
Based on gene mutation patterns and genomic changes we identify lines representative of the FGFR3-driven tumor pathway and of the TP53/RB tumor suppressor-driven pathway. High-density array copy number analysis identified significant focal gains (1q32, 5p13.1-12, 7q11, and 7q33) and losses (i.e. 6p22.1) in regions altered in tumors but not previously described as affected in bladder cell lines. We also identify new evidence for frequent regions of UPD, often coinciding with regions reported to be lost in tumors. Previously undescribed chromosome X losses found in UBC lines also point to potential tumor suppressor genes. Cell lines representative of the FGFR3-driven pathway showed a lower number of UPD events.Conclusions
Overall, there is a predominance of more aggressive tumor subtypes among the cell lines. We provide a cell line classification that establishes their relatedness to the major molecularly-defined bladder tumor subtypes. The compiled information should serve as a useful reference to the bladder cancer research community and should help to select cell lines appropriate for the functional analysis of bladder cancer genes, for example those being identified through massive parallel sequencing.Electronic supplementary material
The online version of this article (doi:10.1186/s12864-015-1450-3) contains supplementary material, which is available to authorized users. 相似文献995.
José David Flores-Félix Luis R. Silva Lina P. Rivera Marta Marcos-García Paula García-Fraile Eustoquio Martínez-Molina Pedro F. Mateos Encarna Velázquez Paula Andrade Raúl Rivas 《PloS one》2015,10(4)
The increasing interest in the preservation of the environment and the health of consumers is changing production methods and food consumption habits. Functional foods are increasingly demanded by consumers because they contain bioactive compounds involved in health protection. In this sense biofertilization using plant probiotics is a reliable alternative to the use of chemical fertilizers, but there are few studies about the effects of plant probiotics on the yield of functional fruits and, especially, on the content of bioactive compounds. In the present work we reported that a strain of genus Phyllobacterium able to produce biofilms and to colonize strawberry roots is able to increase the yield and quality of strawberry plants. In addition, the fruits from plants inoculated with this strain have significantly higher content in vitamin C, one of the most interesting bioactive compounds in strawberries. Therefore the use of selected plant probiotics benefits the environment and human health without agronomical losses, allowing the production of highly functional foods. 相似文献
996.
997.
998.
Paulo FP Pimenta Alessandra S Orfano Ana C Bahia Ana PM Duarte Claudia M Ríos-Velásquez Fabrício F Melo Felipe AC Pessoa Giselle A Oliveira Keillen MM Campos Luis Martínez Villegas Nilton Barnabé Rodrigues Rafael Nacif-Pimenta Rejane C Sim?es Wuelton M Monteiro Rogerio Amino Yara M Traub-Cseko José BP Lima Maria GV Barbosa Marcus VG Lacerda Wanderli P Tadei Nágila FC Secundino 《Memórias do Instituto Oswaldo Cruz》2015,110(1):23-47
In the Americas, areas with a high risk of malaria transmission are mainly located in
the Amazon Forest, which extends across nine countries. One keystone step to
understanding the Plasmodium life cycle in Anopheles species from the Amazon Region
is to obtain experimentally infected mosquito vectors. Several attempts to colonise
Ano- pheles species have been conducted, but with only short-lived success or no
success at all. In this review, we review the literature on malaria transmission from
the perspective of its Amazon vectors. Currently, it is possible to develop
experimental Plasmodium vivax infection of the colonised and field-captured vectors
in laboratories located close to Amazonian endemic areas. We are also reviewing
studies related to the immune response to P. vivax infection of Anopheles aquasalis,
a coastal mosquito species. Finally, we discuss the importance of the modulation of
Plasmodium infection by the vector microbiota and also consider the anopheline
genomes. The establishment of experimental mosquito infections with Plasmodium
falciparum, Plasmodium yoelii and Plasmodium berghei parasites that could provide
interesting models for studying malaria in the Amazonian scenario is important.
Understanding the molecular mechanisms involved in the development of the parasites
in New World vectors is crucial in order to better determine the interaction process
and vectorial competence. 相似文献
999.
The stability of Pseudomonas putida F1, a strain harbouring the genes responsible for toluene degradation in the chromosome was evaluated in a bioscrubber under
high toluene loadings and nitrogen limiting conditions at two dilution rates (0.11 and 0.27 h−1). Each experiment was run for 30 days, period long enough for microbial instability to occur considering previously reported
studies carried out with bacterial strains encoding the catabolic genes in the TOL plasmid. At all tested conditions, P. putida F1 exhibited stable performance as shown by the constant values of the specific toluene degradation yield, CO2 produced versus toluene degraded yield, and biomass concentration within each steady state. Benzyl alcohol, a curing agent
causing TOL plasmid deletion in Pseudomonas strains, was present in the cultivation medium as a result of the monooxygenation of toluene by the diooxygenase system of
P. putida F1. However, no mutant population growing at the expense of the extracellular excreted carbon or lysis products was established
in the chemostat as confirmed by the constant dissolved total organic carbon (TOC) concentration and fraction of toluene degrading
cells (approx. 100%). In addition, batch experiments conducted with both lysis substrate and toluene simultaneously confirmed
that P. putida F1 preferentially consumed toluene rather than extracellular excreted carbon. 相似文献
1000.
Telomeres in many eukaryotes are maintained by telomerase in whose absence telomere shortening occurs. However, telomerase-deficient
Arabidopsis thaliana mutants (Attert
−/−) show extremely low rates of telomere shortening per plant generation (250–500 bp), which does not correspond to the expected
outcome of replicative telomere shortening resulting from ca. 1,000 meristem cell divisions per seed-to-seed generation. To
investigate the influence of the number of cell divisions per seed-to-seed generation, Attert
−/− mutant plants were propagated from seeds coming either from the lower-most or the upper-most siliques (L- and U-plants) and
the length of their telomeres were followed over several generations. The rate of telomere shortening was faster in U-plants,
than in L-plants, as would be expected from their higher number of cell divisions per generation. However, this trend was
observed only in telomeres whose initial length is relatively high and the differences decreased with progressive general
telomere shortening over generations. But in generation 4, the L-plants frequently show a net telomere elongation, while the
U-plants fail to do so. We propose that this is due to the activation of alternative telomere lengthening (ALT), a process
which is activated in early embryonic development in both U- and L-plants, but is overridden in U-plants due to their higher
number of cell divisions per generation. These data demonstrate what so far has only been speculated, that in the absence
of telomerase, the number of cell divisions within one generation influences the control of telomere lengths. These results
also reveal a fast and efficient activation of ALT mechanism(s) in response to the loss of telomerase activity and imply that
ALT is probably involved also in normal plant development. 相似文献