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排序方式: 共有1571条查询结果,搜索用时 93 毫秒
981.
Anna Kärkönen Claudia‐Nicole Meisrimler Enni Väisänen Teresa Laitinen Luis Alexis Jiménez Barboza Sami Holmström Sadette Salonvaara Stefanie Wienkoop Kurt V. Fagerstedt Sabine Lüthje 《Physiologia plantarum》2014,152(4):599-616
There are no earlier reports with successful isolation of plasma membranes from lignin‐forming tissues of conifers. A method to isolate cellular membranes from extracellular lignin‐producing tissue‐cultured cells and developing xylem of Norway spruce was optimized. Modifications to the homogenization buffer were needed to obtain membranes from these phenolics‐rich tissues. Membranes were separated by aqueous polymer two‐phase partitioning. Chlorophyll a determination, marker enzyme assays and western blot analyses using antibodies for each membrane type showed that mitochondrial, chloroplastic and to a certain extent also ER and Golgi membranes were efficiently diminished from the upper phase, but tonoplast and plasma membranes distributed evenly between the upper and lower phases. Redox enzymes present in the partially purified membrane fractions were assayed in order to reveal the origin of H2O2 needed for lignification. The membranes of spruce contained enzymes able to generate superoxide in the presence of NAD(P)H. Besides members of the flavodoxin and flavodoxin‐like family proteins, cytochrome b5, cytochrome P450 and several stress responsive proteins were identified by nitroblue tetrazolium staining of isoelectric focusing gels and by mass spectrometry. Naphthoquinones juglone and menadione increased superoxide production in activity‐stained gels. Some juglone‐activated enzymes were preferentially using NADH. With NADH, menadione activated only some of the enzymes that juglone did, whereas with NADPH the activation patterns were identical. Duroquinone, a benzoquinone, did not affect superoxide production. Superoxide dismutase, ascorbate peroxidase, catalase and an acidic class III peroxidase isoenzyme were detected in partially purified spruce membranes. The possible locations and functions of these enzymes are discussed. 相似文献
982.
Sandra B. Visnovsky Nicholas Cummings Alexis Guerin-Laguette Yun Wang Akiyoshi Yamada Hisayasu Kobayashi Masataka Kawai Andrew R. Pitman 《Mycorrhiza》2014,24(6):453-463
Lyophyllum shimeji is an edible ectomycorrhizal fungus that is widely distributed in East Asia and also present in the northern regions of Europe. In Japan, L. shimeji is a culinary delicacy, considered amongst all edible mushrooms to have the best taste and to be second only to Tricholoma matsutake in price. Traditionally, fruiting bodies of L. shimeji have been collected from the wild but fruiting of L. shimeji is now relatively uncommon and cannot keep up with increasing consumer demand. As a result, methods for its cultivation are being developed for commercial production in Japan and other countries. In this work, techniques were developed to cultivate L. shimeji on coniferous seedlings using a pure culture inoculum. They resulted in successful mycorrhization of Pinus pinaster and Picea abies in only 8 to 10 months. As ectomycorrhizae of L. shimeji are difficult to identify morphologically, mycorrhization was confirmed using an L. shimeji-specific PCR diagnostic, which was designed following a phylogenetic analysis of the Lyophyllum section Difformia using DNA sequences of the internal transcribed spacer (ITS), intergenic spacer (IGS) and elongation factor 1-α (EF1-α) gene. L. shimeji is a member of the Lyophyllum decastes complex in section Difformia, which also includes Lyophyllum fumosum and L. decastes. This analysis confirmed the separation of L. shimeji from closely related Lyophyllum spp. and enabled its unambiguous detection using an IGS-based PCR diagnostic. This is the first report of successful mycorrhization of L. shimeji on P. pinaster and P. abies and provides an opportunity for its commercial cultivation on conifers in New Zealand. 相似文献
983.
Maria-Cristina Ciobanu Ga?tan Burgaud Alexis Dufresne Anja Breuker Vanessa Rédou Sarah Ben Maamar Frédéric Gaboyer Odile Vandenabeele-Trambouze Julius Sebastian Lipp Axel Schippers Philippe Vandenkoornhuyse Georges Barbier Mohamed Jebbar Anne Godfroy Karine Alain 《The ISME journal》2014,8(7):1370-1380
The subsurface realm is colonized by microbial communities to depths of >1000 meters below the seafloor (m.b.sf.), but little is known about overall diversity and microbial distribution patterns at the most profound depths. Here we show that not only Bacteria and Archaea but also Eukarya occur at record depths in the subseafloor of the Canterbury Basin. Shifts in microbial community composition along a core of nearly 2 km reflect vertical taxa zonation influenced by sediment depth. Representatives of some microbial taxa were also cultivated using methods mimicking in situ conditions. These results suggest that diverse microorganisms persist down to 1922 m.b.sf. in the seafloor of the Canterbury Basin and extend the previously known depth limits of microbial evidence (i) from 159 to 1740 m.b.sf. for Eukarya and (ii) from 518 to 1922 m.b.sf. for Bacteria. 相似文献
984.
985.
Jason P. Wendler John Okombo Roberto Amato Olivo Miotto Steven M. Kiara Leah Mwai Lewa Pole John O'Brien Magnus Manske Dan Alcock Eleanor Drury Mandy Sanders Samuel O. Oyola Cinzia Malangone Dushyanth Jyothi Alistair Miles Kirk A. Rockett Bronwyn L. MacInnis Kevin Marsh Philip Bejon Alexis Nzila Dominic P. Kwiatkowski 《PloS one》2014,9(5)
Background
Drug resistance remains a chief concern for malaria control. In order to determine the genetic markers of drug resistant parasites, we tested the genome-wide associations (GWA) of sequence-based genotypes from 35 Kenyan P. falciparum parasites with the activities of 22 antimalarial drugs.Methods and Principal Findings
Parasites isolated from children with acute febrile malaria were adapted to culture, and sensitivity was determined by in vitro growth in the presence of anti-malarial drugs. Parasites were genotyped using whole genome sequencing techniques. Associations between 6250 single nucleotide polymorphisms (SNPs) and resistance to individual anti-malarial agents were determined, with false discovery rate adjustment for multiple hypothesis testing. We identified expected associations in the pfcrt region with chloroquine (CQ) activity, and other novel loci associated with amodiaquine, quinazoline, and quinine activities. Signals for CQ and primaquine (PQ) overlap in and around pfcrt, and interestingly the phenotypes are inversely related for these two drugs. We catalog the variation in dhfr, dhps, mdr1, nhe, and crt, including novel SNPs, and confirm the presence of a dhfr-164L quadruple mutant in coastal Kenya. Mutations implicated in sulfadoxine-pyrimethamine resistance are at or near fixation in this sample set.Conclusions/Significance
Sequence-based GWA studies are powerful tools for phenotypic association tests. Using this approach on falciparum parasites from coastal Kenya we identified known and previously unreported genes associated with phenotypic resistance to anti-malarial drugs, and observe in high-resolution haplotype visualizations a possible signature of an inverse selective relationship between CQ and PQ. 相似文献986.
987.
Paul E. Sax Alexis Sypek Bethany K. Berkowitz Bethany L. Morris Elena Losina A. David Paltiel Kathleen A. Kelly George R. Seage III Rochelle P. Walensky Milton C. Weinstein Joseph Eron Kenneth A. Freedberg 《PloS one》2014,9(11)
Background
We examined efficacy, toxicity, relapse, cost, and quality-of-life thresholds of hypothetical HIV cure interventions that would make them cost-effective compared to life-long antiretroviral therapy (ART).Methods
We used a computer simulation model to assess three HIV cure strategies: Gene Therapy, Chemotherapy, and Stem Cell Transplantation (SCT), each compared to ART. Efficacy and cost parameters were varied widely in sensitivity analysis. Outcomes included quality-adjusted life expectancy, lifetime cost, and cost-effectiveness in dollars/quality-adjusted life year ($/QALY) gained. Strategies were deemed cost-effective with incremental cost-effectiveness ratios <$100,000/QALY.Results
For patients on ART, discounted quality-adjusted life expectancy was 16.4 years and lifetime costs were $591,400. Gene Therapy was cost-effective with efficacy of 10%, relapse rate 0.5%/month, and cost $54,000. Chemotherapy was cost-effective with efficacy of 88%, relapse rate 0.5%/month, and cost $12,400/month for 24 months. At $150,000/procedure, SCT was cost-effective with efficacy of 79% and relapse rate 0.5%/month. Moderate efficacy increases and cost reductions made Gene Therapy cost-saving, but substantial efficacy/cost changes were needed to make Chemotherapy or SCT cost-saving.Conclusions
Depending on efficacy, relapse rate, and cost, cure strategies could be cost-effective compared to current ART and potentially cost-saving. These results may help provide performance targets for developing cure strategies for HIV. 相似文献988.
Alexis S. Ivanov Alexei Medvedev Pavel Ershov Andrey Molnar Yury Mezentsev Evgeny Yablokov Leonid Kaluzhsky Oksana Gnedenko Olga Buneeva Irina Haidukevich Gennadiy Sergeev Aliaksandr Lushchyk Alexey Yantsevich Marina Medvedeva Sergey Kozin Igor Popov Svetlana Novikova Victor Zgoda Andrey Gilep Sergey Usanov Andrey Lisitsa Alexander Archakov 《Proteomics》2014,14(20):2261-2274
There is increasing evidence that proteins function in the cell as integrated stable or temporally formed protein complexes, interactomes. Previously, using model systems we demonstrated applicability of direct molecular fishing on paramagnetic particles for protein interactomics (Ershov et al. Proteomics, 2012, 12, 3295). In the present study, we have used a combination of affinity‐based molecular fishing and subsequent MS for investigation of human liver proteins involved in interactions with immobilized microsomal cytochrome b5 (CYB5A), and also transthyretin and BSA as alternative affinity ligands (baits). The LC?MS/MS identification of prey proteins fished on these baits revealed three sets of proteins: 98, 120, and 220, respectively. Comparison analysis of these sets revealed only three proteins common for all the baits. In the case of paired analysis, the number of common proteins varied from 2 to 9. The binding capacity of some identified proteins has been validated by a SPR‐based biosensor. All the investigated proteins effectively interacted with the immobilized CYB5A (Kd values ranged from 0.07 to 1.1 μM). Results of this study suggest that direct molecular fishing is applicable for analysis of protein–protein interactions (PPI) under normal and pathological conditions, in which altered PPIs are especially important. 相似文献
989.
Anastasia Evanoff Erika L. Sabbath Matthieu Carton Sebastien Czernichow Marie Zins Annette Leclerc Alexis Descatha 《PloS one》2014,9(10)
Objective
To analyze relationships between physical occupational exposures, post-retirement shoulder/knee pain, and obesity.Methods
9 415 male participants (aged 63–73 in 2012) from the French GAZEL cohort answered self-administered questionnaires in 2006 and 2012. Occupational exposures retrospectively assessed in 2006 included arm elevation and squatting (never, <10 years, ≥10 years). “Severe” shoulder and knee pain were defined as ≥5 on an 8-point scale. BMI was self-reported.Results
Mean BMI was 26.59 kg/m2 +/−3.5 in 2012. Long-term occupational exposure to arm elevation and squatting predicted severe shoulder and knee pain after retirement. Obesity (BMI≥30 kg/m2) was a risk factor for severe shoulder pain (adjusted OR 1.28; 95% CI 1.03, 1.90). Overweight (adjusted OR 1.71; 1.28,2.29) and obesity (adjusted OR 3.21; 1.90,5.41) were risk factors for severe knee pain. In stratified models, associations between long-term squatting and severe knee pain varied by BMI.Conclusion
Obesity plays a role in relationships between occupational exposures and musculoskeletal pain. Further prospective studies should use BMI in analyses of musculoskeletal pain and occupational factors, and continue to clarify this relationship. 相似文献990.
Elyse Berger Pelletier Marcel émond Fran?ois Lauzier Martin Savard Alexis F. Turgeon 《PloS one》2014,9(4)