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111.
Aditya Malkar Neil A. Devenport Helen J. Martin Pareen Patel Matthew A. Turner Phillip Watson Ronald J. Maughan Helen J. Reid Barry L. Sharp C. L. Paul Thomas James C. Reynolds Colin S. Creaser 《Metabolomics : Official journal of the Metabolomic Society》2013,9(6):1192-1201
A method has been developed for metabolite profiling of the salivary metabolome based on protein precipitation and ultra-high performance liquid chromatography coupled with ion mobility-mass spectrometry (UHPLC–IM–MS). The developed method requires 0.5 mL of human saliva, which is easily obtainable by passive drool. Standard protocols have been established for the collection, storage and pre-treatment of saliva. The use of UHPLC allows rapid global metabolic profiling for biomarker discovery with a cycle time of 15 min. Mass spectrometry imparts the ability to analyse a diverse number of species reproducibly over a wide dynamic range, which is essential for profiling of biofluids. The combination of UHPLC with IM–MS provides an added dimension enabling complex metabolic samples to be separated on the basis of retention time, ion mobility and mass-to-charge ratio in a single chromatographic run. The developed method has been applied to targeted metabolite identification and untargeted metabolite profiling of saliva samples collected before and after exercise-induced physiological stress. δ-Valerolactam has been identified as a potential biomarker on the basis of retention time, MS/MS spectrum and ion mobility drift time. 相似文献
112.
Dong Zhang Ana B. Asenjo Michaela Greenbaum Luping Xie David J. Sharp Hernando Sosa 《PloS one》2013,8(8)
Kinesin-13s are microtubule (MT) depolymerases different from most other kinesins that move along MTs. Like other kinesins, they have a motor or head domain (HD) containing a tubulin and an ATP binding site. Interestingly, kinesin-13s have an additional binding site (Kin-Tub-2) on the opposite side of the HD that contains several family conserved positively charged residues. The role of this site in kinesin-13 function is not clear. To address this issue, we investigated the in-vitro and in-vivo effects of mutating Kin-Tub-2 family conserved residues on the Drosophila melanogaster kinesin-13, KLP10A. We show that the Kin-Tub-2 site enhances tubulin cross-linking and MT bundling properties of KLP10A in-vitro. Disruption of the Kin-Tub-2 site, despite not having a deleterious effect on MT depolymerization, results in abnormal mitotic spindles and lagging chromosomes during mitosis in
Drosophila
S2 cells. The results suggest that the additional Kin-Tub-2 tubulin biding site plays a direct MT attachment role in-vivo. 相似文献
113.
Previous studies have suggested that sugars enhance iron bioavailability, possibly through either chelation or altering the oxidation state of the metal, however, results have been inconclusive. Sugar intake in the last 20 years has increased dramatically, and iron status disorders are significant public health problems worldwide; therefore understanding the nutritional implications of iron-sugar interactions is particularly relevant. In this study we measured the effects of sugars on non-heme iron bioavailability in human intestinal Caco-2 cells and HepG2 hepatoma cells using ferritin formation as a surrogate marker for iron uptake. The effect of sugars on iron oxidation state was examined by measuring ferrous iron formation in different sugar-iron solutions with a ferrozine-based assay. Fructose significantly increased iron-induced ferritin formation in both Caco-2 and HepG2 cells. In addition, high-fructose corn syrup (HFCS-55) increased Caco-2 cell iron-induced ferritin; these effects were negated by the addition of either tannic acid or phytic acid. Fructose combined with FeCl3 increased ferrozine-chelatable ferrous iron levels by approximately 300%. In conclusion, fructose increases iron bioavailability in human intestinal Caco-2 and HepG2 cells. Given the large amount of simple and rapidly digestible sugars in the modern diet their effects on iron bioavailability may have important patho-physiological consequences. Further studies are warranted to characterize these interactions. 相似文献
114.
Ephrath Jhonathan E. Klein Tamir Sharp Robert E. Lazarovitch Naftali 《Plant and Soil》2020,453(1-2):1-13
Plant and Soil - Soil organic matter (SOM) supports multiple soil ecosystem functions, underpinned by processes such as C sequestration, N mineralization, aggregation, promotion of plant health and... 相似文献
115.
Coral Reefs - Coral reefs in the Florida Keys have degraded in recent decades, prompting efforts to re-establish populations of staghorn coral, Acropora cervicornis, to restore structure and... 相似文献
116.
117.
Bark beetle infestation impacts on nutrient cycling, water quality and interdependent hydrological effects 总被引:1,自引:0,他引:1
Kristin M. Mikkelson Lindsay A. Bearup Reed M. Maxwell John D. Stednick John E. McCray Jonathan O. Sharp 《Biogeochemistry》2013,115(1-3):1-21
Bark beetle populations have drastically increased in magnitude over the last several decades leading to the largest-scale tree mortality ever recorded from an insect infestation on multiple wooded continents. When the trees die, the loss of canopy and changes in water and nutrient uptake lead to observable changes in hydrology and biogeochemical cycling. This review aims to synthesize the current research on the effects of the bark beetle epidemic on nutrient cycling and water quality while integrating recent and relevant hydrological findings, along with suggesting necessary future research avenues. Studies generally agree that snow depth will increase in infested forests, though the magnitude is uncertain. Changes in evapotranspiration are more variable as decreased transpiration from tree death may be offset by increased understory evapotranspiration and ground evaporation. As a result of such competing hydrologic processes that can affect watershed biogeochemistry along with the inherent variability of natural watershed characteristics, water quality changes related to beetle infestation are difficult to predict and may be regionally distinct. However, tree-scale changes to soil–water chemistry (N, P, DOC and base cation concentrations and composition) are being observed in association with beetle outbreaks which ultimately could lead to larger-scale responses. The different temporal and spatial patterns of bark beetle infestations due to different beetle and tree species lead to inconsistent infestation impacts. Climatic variations and large-scale watershed responses provide a further challenge for predictions due to spatial heterogeneities within a single watershed; conflicting reports from different regions suggest that hydrologic and water quality impacts of the beetle on watersheds cannot be generalized. Research regarding the subsurface water and chemical flow-paths and residence times after a bark beetle epidemic is lacking and needs to be rigorously addressed to best predict watershed or regional-scale changes to soil–water, groundwater, and stream water chemistry. 相似文献
118.
Nathaniel P. Sharp Aneil F. Agrawal 《Evolution; international journal of organic evolution》2013,67(4):1189-1195
In populations with males and females, sexual selection may often represent a major component of overall selection. Sexual selection could act to eliminate deleterious alleles in concert with other forms of selection, thereby improving the fitness of sexual populations. Alternatively, the divergent reproductive strategies of the sexes could promote the maintenance of sexually antagonistic variation, causing sexual populations to be less fit. The net impact of sexual selection on fitness is not well understood, due in part to limited data on the sex‐specific effects of spontaneous mutations on total fitness. Using a set of mutation accumulation lines of Drosophila melanogaster, we found that mutations were deleterious in both sexes and had larger effects on fitness in males than in females. This pattern is expected to reduce the mutation load of sexual females and promote the maintenance of sexual reproduction. 相似文献
119.
Cecil M. Lewis Jr Laura-Isobel McCall Richard R. Sharp Paul G. Spicer 《American journal of physical anthropology》2020,171(2):177-181
The metabolome is a system of small biomolecules (metabolites) and a direct result of human bioculture. Consequently, metabolomics is well poised to impact anthropological and biomedical research for the foreseeable future. Overall, we provide a perspective on the ethical, legal, and social implications (ELSI) of metabolomics, which we argue are often more alarming than those of genomics. Given the current mechanisms to fund research, ELSI beyond human DNA is stifled and in need of considerable attention. 相似文献
120.
Parinya Chamnan Rebecca K. Simmons Stephen J. Sharp Kay-Tee Khaw Nicholas J. Wareham Simon J. Griffin 《PloS one》2016,11(2)