Sample records for global nmr declined
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Globalization and the price decline of illicit drugs.
Costa Storti, Cláudia; De Grauwe, Paul
2009-01-01
This study aims at understanding the mechanisms underlying the dramatic decline of the retail prices of major drugs like cocaine and heroin during the past two decades. It also aims at analysing the implications of this decline for drug policies. We use a theoretical model to identify the possible causes of this price decline. This allows us to formulate the hypothesis that the major driving force behind the price decline is a reduction of the intermediation margin (the difference between the retail and producer prices). We also develop the hypothesis that globalization has been an important factor behind the decline of the intermediation margin. We then analyse the statistical information to test these hypotheses. We find that the decline in the retail prices of drugs is related to the strong decline in the intermediation margin in the drug business, and that globalization is the main driving force behind this phenomenon. Globalization has done so by increasing the efficiency of the distribution of drugs, by reducing the risk premium involved in dealing with drugs, and by increasing the degree of competition in the drug markets. We conclude that the cocaine and heroin price declines were due to a sharp fall in the intermediation margin, which was probably influenced by globalization. This phenomenon might have a strong impact on the effectiveness of drug policies, increasing the relative effectiveness of policies aiming at reducing the demand of drugs.
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Fast mapping of global protein folding states by multivariate NMR:
DEFF Research Database (Denmark)
Malmendal, Anders; Underhaug, Jarl; Otzen, Daniel
2010-01-01
To obtain insight into the functions of proteins and their specific roles, it is important to establish efficient procedures for exploring the states that encapsulate their conformational space. Global Protein folding State mapping by multivariate NMR (GPS NMR) is a powerful high-throughput method......-lactalbumin in the presence of the anionic surfactant sodium dodecyl sulfate, SDS, and compare these with other surfactants, acid, denaturants and heat....
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Guiding automated NMR structure determination using a global optimization metric, the NMR DP score
Energy Technology Data Exchange (ETDEWEB)
Huang, Yuanpeng Janet, E-mail: yphuang@cabm.rutgers.edu; Mao, Binchen; Xu, Fei; Montelione, Gaetano T., E-mail: gtm@rutgers.edu [Rutgers, The State University of New Jersey, Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, and Northeast Structural Genomics Consortium (United States)
2015-08-15
ASDP is an automated NMR NOE assignment program. It uses a distinct bottom-up topology-constrained network anchoring approach for NOE interpretation, with 2D, 3D and/or 4D NOESY peak lists and resonance assignments as input, and generates unambiguous NOE constraints for iterative structure calculations. ASDP is designed to function interactively with various structure determination programs that use distance restraints to generate molecular models. In the CASD–NMR project, ASDP was tested and further developed using blinded NMR data, including resonance assignments, either raw or manually-curated (refined) NOESY peak list data, and in some cases {sup 15}N–{sup 1}H residual dipolar coupling data. In these blinded tests, in which the reference structure was not available until after structures were generated, the fully-automated ASDP program performed very well on all targets using both the raw and refined NOESY peak list data. Improvements of ASDP relative to its predecessor program for automated NOESY peak assignments, AutoStructure, were driven by challenges provided by these CASD–NMR data. These algorithmic improvements include (1) using a global metric of structural accuracy, the discriminating power score, for guiding model selection during the iterative NOE interpretation process, and (2) identifying incorrect NOESY cross peak assignments caused by errors in the NMR resonance assignment list. These improvements provide a more robust automated NOESY analysis program, ASDP, with the unique capability of being utilized with alternative structure generation and refinement programs including CYANA, CNS, and/or Rosetta.
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Global amphibian declines: perspectives from the United States and beyond
Densmore, Christine L.; Cipriano, R.C.; Bruckner, A.W.; Shchelkunov, I.S.
2011-01-01
Over recent decades, amphibians have experienced population declines, extirpations and species-level extinctions at an alarming rate. Numerous potential etiologies for amphibian declines have been postulated including climate and habitat degradation. Other potential anthropogenic causes including overexploitation and the frequent introductions of invasive predatory species have also been blamed for amphibian declines. Still other underlying factors may include infectious diseases caused by the chytrid fungus Batrachochytrium dendrobatidis, pathogenic viruses (Ranavirus), and other agents. It is nearly certain that more than one etiology is to blame for the majority of the global amphibian declines, and that these causal factors include some combination of climatological or physical habitat destabilization and infectious disease, most notably chytridiomycosis. Scientific research efforts are aimed at elucidating these etiologies on local, regional, and global scales that we might better understand and counteract the driving forces behind amphibian declines. Conservation efforts as outlined in the Amphibian Conservation Action Plan of 2005 are also being made to curtail losses and prevent further extinctions wherever possible.
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Age-related decline in global form suppression
DEFF Research Database (Denmark)
Wiegand, Iris Michaela; Finke, Kathrin; Töllner, Thomas
2015-01-01
. Selective attention, i.e., the ability to focus on relevant and ignore irrelevant information, declines with increasing age; however, how this deficit affects selection of global vs. local configurations remains unknown. On this background, the present study examined for age-related differences in a global...... differences in the subsequent (250–500 ms) posterior contralateral negativity (PCN) indicated that attentional resources were allocated faster to Kanisza, as compared to non-Kanisza, targets in both age groups, while the allocation of spatial attention seemed to be generally delayed in older relative...... to younger age. Our results suggest that the enhanced global-local asymmetry in the older age group originated from less effective suppression of global distracter forms on early processing stages – indicative of older observers having difficulties with disengaging from a global default selection mode...
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Global change and the decline of coral reefs
Strasser, A.
1999-01-01
Ever since coral reefs exist, changing environmental conditions have periodically led to their decline. However, within the perspective of geological time-spans, corals have always managed to re-install themselves. Today, human activity has enhanced stress factors and added new ones that cause a rapid and (on the human time-scale) irreversible decline of many reef ecosystems. The reasons for the disturbance of these complex communities are multiple, but global warming is a k...
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The cause of global amphibian declines: a developmental endocrinologist's perspective.
Hayes, T B; Falso, P; Gallipeau, S; Stice, M
2010-03-15
Greater than 70% of the world's amphibian species are in decline. We propose that there is probably not a single cause for global amphibian declines and present a three-tiered hierarchical approach that addresses interactions among and between ultimate and proximate factors that contribute to amphibian declines. There are two immediate (proximate) causes of amphibian declines: death and decreased recruitment (reproductive failure). Although much attention has focused on death, few studies have addressed factors that contribute to declines as a result of failed recruitment. Further, a great deal of attention has focused on the role of pathogens in inducing diseases that cause death, but we suggest that pathogen success is profoundly affected by four other ultimate factors: atmospheric change, environmental pollutants, habitat modification and invasive species. Environmental pollutants arise as likely important factors in amphibian declines because they have realized potential to affect recruitment. Further, many studies have documented immunosuppressive effects of pesticides, suggesting a role for environmental contaminants in increased pathogen virulence and disease rates. Increased attention to recruitment and ultimate factors that interact with pathogens is important in addressing this global crisis.
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Measuring the meltdown: drivers of global amphibian extinction and decline.
Directory of Open Access Journals (Sweden)
Navjot S Sodhi
Full Text Available Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545 or had increased (n = 28. These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.
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Measuring the meltdown: drivers of global amphibian extinction and decline.
Sodhi, Navjot S; Bickford, David; Diesmos, Arvin C; Lee, Tien Ming; Koh, Lian Pin; Brook, Barry W; Sekercioglu, Cagan H; Bradshaw, Corey J A
2008-02-20
Habitat loss, climate change, over-exploitation, disease and other factors have been hypothesised in the global decline of amphibian biodiversity. However, the relative importance of and synergies among different drivers are still poorly understood. We present the largest global analysis of roughly 45% of known amphibians (2,583 species) to quantify the influences of life history, climate, human density and habitat loss on declines and extinction risk. Multi-model Bayesian inference reveals that large amphibian species with small geographic range and pronounced seasonality in temperature and precipitation are most likely to be Red-Listed by IUCN. Elevated habitat loss and human densities are also correlated with high threat risk. Range size, habitat loss and more extreme seasonality in precipitation contributed to decline risk in the 2,454 species that declined between 1980 and 2004, compared to species that were stable (n = 1,545) or had increased (n = 28). These empirical results show that amphibian species with restricted ranges should be urgently targeted for conservation.
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The link between rapid enigmatic amphibian decline and the globally emerging chytrid fungus.
Lötters, Stefan; Kielgast, Jos; Bielby, Jon; Schmidtlein, Sebastian; Bosch, Jaime; Veith, Michael; Walker, Susan F; Fisher, Matthew C; Rödder, Dennis
2009-09-01
Amphibians are globally declining and approximately one-third of all species are threatened with extinction. Some of the most severe declines have occurred suddenly and for unknown reasons in apparently pristine habitats. It has been hypothesized that these "rapid enigmatic declines" are the result of a panzootic of the disease chytridiomycosis caused by globally emerging amphibian chytrid fungus. In a Species Distribution Model, we identified the potential distribution of this pathogen. Areas and species from which rapid enigmatic decline are known significantly overlap with those of highest environmental suitability to the chytrid fungus. We confirm the plausibility of a link between rapid enigmatic decline in worldwide amphibian species and epizootic chytridiomycosis.
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A human-driven decline in global burned area
Andela, N.
2017-12-01
Fire regimes are changing rapidly across the globe, driven by human land management and climate. We assessed long-term trends in fire activity using multiple satellite data sets and developed a new global data set on individual fire dynamics to understand the implications of changing fire regimes. Despite warming climate, burned area declined across most of the tropics, contributing to a global decline in burned area of 24.3 ± 8.8% over the past 18 years. The estimated decrease in burned area was largest in savannas and grasslands, where agricultural expansion and intensification were primary drivers of declining fire activity. In tropical forests, frequent fires for deforestation and agricultural management yield a sharp rise in fire activity with the expansion of settled land uses, but the use of fire decreases with increasing investment in agricultural areas in both savanna and forested landscapes. Disparate patterns of recent socieconomic development resulted in contrasting fire trends between southern Africa (increase) and South America (decrease). A strong inverse relationship between burned area and economic development in savannas and grasslands suggests that despite potential increasing fire risk from climate change, ongoing socioeconomic development will likely sustain observed declines in fire in these ecosystems during coming decades. Fewer and smaller fires reduced aerosol concentrations, modified vegetation structure, and increased the magnitude of the terrestrial carbon sink. The spatiotemporal distribution of fire size, duration, speed and direction of spread provided new insights in continental scale differences in fire regimes driven by human and climatic factors. Understanding these dynamics over larger scales is critical to achieve a balance between conservation of fire-dependent ecosystems and increasing agricultural production to support growing populations that will require careful management of fire activity in human-dominated landscapes.
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A global analysis of NMR distance constraints from the PDB
International Nuclear Information System (INIS)
Vranken, Wim
2007-01-01
Information obtained from Nuclear Magnetic Resonance (NMR) experiments is encoded as a set of constraint lists when calculating three-dimensional structures for a protein. With the amount of constraint data from the world wide Protein Data Bank (wwPDB) that is now available, it is possible to do a global, large-scale analysis using only information from the constraints, without taking the coordinate information into account. This article describes such an analysis of distance constraints from NOE data based on a set of 1834 NMR PDB entries containing 1909 protein chains. In order to best represent the quality and extent of the data that is currently deposited at the wwPDB, only the original data as deposited by the authors was used, and no attempt was made to 'clean up' and further interpret this information. Because the constraint lists provide a single set of data, and not an ensemble of structural solutions, they are easier to analyse and provide a reduced form of structural information that is relevant for NMR analysis only. The online resource resulting from this analysis makes it possible to check, for example, how often a particular contact occurs when assigning NOESY spectra, or to find out whether a particular sequence fragment is likely to be difficult to assign. In this respect it formalises information that scientists with experience in spectrum analysis are aware of but cannot necessarily quantify. The analysis described here illustrates the importance of depositing constraints (and all other possible NMR derived information) along with the structure coordinates, as this type of information can greatly assist the NMR community
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A human-driven decline in global burned area.
Andela, N; Morton, D C; Giglio, L; Chen, Y; van der Werf, G R; Kasibhatla, P S; DeFries, R S; Collatz, G J; Hantson, S; Kloster, S; Bachelet, D; Forrest, M; Lasslop, G; Li, F; Mangeon, S; Melton, J R; Yue, C; Randerson, J T
2017-06-30
Fire is an essential Earth system process that alters ecosystem and atmospheric composition. Here we assessed long-term fire trends using multiple satellite data sets. We found that global burned area declined by 24.3 ± 8.8% over the past 18 years. The estimated decrease in burned area remained robust after adjusting for precipitation variability and was largest in savannas. Agricultural expansion and intensification were primary drivers of declining fire activity. Fewer and smaller fires reduced aerosol concentrations, modified vegetation structure, and increased the magnitude of the terrestrial carbon sink. Fire models were unable to reproduce the pattern and magnitude of observed declines, suggesting that they may overestimate fire emissions in future projections. Using economic and demographic variables, we developed a conceptual model for predicting fire in human-dominated landscapes. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.
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Declining Global Per Capita Agricultural Production and Warming Oceans Threaten Food Security
Funk, Chris C.; Brown, Molly E.
2009-01-01
Despite accelerating globalization, most people still eat food that was grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be controlled by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices, and policies. In this paper we discuss several emerging threats to global and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia, and Central and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production will potentially decline by 14 percent between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific Oceans, may also reduce 21 st century food availability by disrupting Indian Ocean moisture transports and tilting the 21 st century climate toward a more El Nino-like state. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian Ocean warming appears to have already reduced main growing season rainfall along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, we present an analysis of
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Declining global per capita agricultural production and warming oceans threaten food security
Funk, Christopher C.; Brown, Molly E.
2009-01-01
Despite accelerating globalization, most people still eat food that is grown locally. Developing countries with weak purchasing power tend to import as little food as possible from global markets, suffering consumption deficits during times of high prices or production declines. Local agricultural production, therefore, is critical to both food security and economic development among the rural poor. The level of local agricultural production, in turn, will be determined by the amount and quality of arable land, the amount and quality of agricultural inputs (fertilizer, seeds, pesticides, etc.), as well as farm-related technology, practices and policies. This paper discusses several emerging threats to global and regional food security, including declining yield gains that are failing to keep up with population increases, and warming in the tropical Indian Ocean and its impact on rainfall. If yields continue to grow more slowly than per capita harvested area, parts of Africa, Asia and Central and Southern America will experience substantial declines in per capita cereal production. Global per capita cereal production will potentially decline by 14% between 2008 and 2030. Climate change is likely to further affect food production, particularly in regions that have very low yields due to lack of technology. Drought, caused by anthropogenic warming in the Indian and Pacific Oceans, may also reduce 21st century food availability in some countries by disrupting moisture transports and bringing down dry air over crop growing areas. The impacts of these circulation changes over Asia remain uncertain. For Africa, however, Indian Ocean warming appears to have already reduced rainfall during the main growing season along the eastern edge of tropical Africa, from southern Somalia to northern parts of the Republic of South Africa. Through a combination of quantitative modeling of food balances and an examination of climate change, this study presents an analysis of emerging
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Rohr, Jason R; Raffel, Thomas R
2010-05-04
The role of global climate change in the decline of biodiversity and the emergence of infectious diseases remains controversial, and the effect of climatic variability, in particular, has largely been ignored. For instance, it was recently revealed that the proposed link between climate change and widespread amphibian declines, putatively caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), was tenuous because it was based on a temporally confounded correlation. Here we provide temporally unconfounded evidence that global El Niño climatic events drive widespread amphibian losses in genus Atelopus via increased regional temperature variability, which can reduce amphibian defenses against pathogens. Of 26 climate variables tested, only factors associated with temperature variability could account for the spatiotemporal patterns of declines thought to be associated with Bd. Climatic predictors of declines became significant only after controlling for a pattern consistent with epidemic spread (by temporally detrending the data). This presumed spread accounted for 59% of the temporal variation in amphibian losses, whereas El Niño accounted for 59% of the remaining variation. Hence, we could account for 83% of the variation in declines with these two variables alone. Given that global climate change seems to increase temperature variability, extreme climatic events, and the strength of Central Pacific El Niño episodes, climate change might exacerbate worldwide enigmatic declines of amphibians, presumably by increasing susceptibility to disease. These results suggest that changes to temperature variability associated with climate change might be as significant to biodiversity losses and disease emergence as changes to mean temperature.
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Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian
2016-01-01
Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron–astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m+/+ Leprdb/J) mice with cognitive decline using 13C NMR technique in combination with intravenous [2-13C]-acetate and [3-13C]-lactate infusions. We found that the 13C-enrichment from [2-13C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3-13C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2-13C]-acetate infusion. However, [3-13C]-lactate resulted in increased 13C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron–astrocyte cooperation and an enhancement of gluconeogenesis. PMID:26762505
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Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian; Gao, Hongchang
2017-01-01
Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron-astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m +/+ Leprdb/J) mice with cognitive decline using 13 C NMR technique in combination with intravenous [2- 13 C]-acetate and [3- 13 C]-lactate infusions. We found that the 13 C-enrichment from [2- 13 C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significantly decreased in db/db mice with cognitive decline compared with wild-type (WT, C57BLKS/J) mice, while an opposite result was obtained after [3- 13 C]-lactate infusion. Relative to WT mice, db/db mice with cognitive decline had significantly lower 13 C labeling percentages in neurotransmitters including glutamine, glutamate, and γ-aminobutyric acid after [2- 13 C]-acetate infusion. However, [3- 13 C]-lactate resulted in increased 13 C-enrichments in neurotransmitters in db/db mice with cognitive decline. This may indicate that the disturbance of neurotransmitter metabolism occurred during the development of cognitive decline. In addition, a reduction in 13 C-labeling of lactate and an increase in gluconeogenesis were found from both labeled infusions in db/db mice with cognitive decline. Therefore, our results suggest that the development of cognitive decline in type 2 diabetes may be implicated to an unbalanced metabolism in neuron-astrocyte cooperation and an enhancement of gluconeogenesis. © The Author(s) 2016.
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GLOBALIZATION AND THE DECLINE OF THE UNITED STATES ECONOMIC INSTRUMENT OF POWER
2017-06-01
of global trade relations. Whereas forty years ago, 90 percent of international trade consisted of mercantilist goods; today , 90 percent of... GLOBALIZATION AND THE DECLINE OF THE UNITED STATES ECONOMIC INSTRUMENT OF POWER BY MAJOR JOSH WATKINS A THESIS PRESENTED TO THE...bachelor of business administration degree from Old Dominion University in 2001. He was commissioned through Officer Training School in 2002 and his
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Zheng, Hong; Zheng, Yongquan; Wang, Dan; Cai, Aimin; Lin, Qiuting; Zhao, Liangcai; Chen, Minjiang; Deng, Mingjie; Ye, Xinjian; Gao, Hongchang
2016-01-01
Type 2 diabetes has been linked to cognitive impairment, but its potential metabolic mechanism is still unclear. The present study aimed to explore neuron–astrocyte metabolic cooperation in the brain of diabetic (db/db, BKS.Cg-m+/+ Leprdb/J) mice with cognitive decline using 13C NMR technique in combination with intravenous [2-13C]-acetate and [3-13C]-lactate infusions. We found that the 13C-enrichment from [2-13C]-acetate into tricarboxylic acid cycle intermediate, succinate, was significant...
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Terrestrial pesticide exposure of amphibians: an underestimated cause of global decline?
Brühl, Carsten A; Schmidt, Thomas; Pieper, Silvia; Alscher, Annika
2013-01-01
Amphibians, a class of animals in global decline, are present in agricultural landscapes characterized by agrochemical inputs. Effects of pesticides on terrestrial life stages of amphibians such as juvenile and adult frogs, toads and newts are little understood and a specific risk assessment for pesticide exposure, mandatory for other vertebrate groups, is currently not conducted. We studied the effects of seven pesticide products on juvenile European common frogs (Rana temporaria) in an agricultural overspray scenario. Mortality ranged from 100% after one hour to 40% after seven days at the recommended label rate of currently registered products. The demonstrated toxicity is alarming and a large-scale negative effect of terrestrial pesticide exposure on amphibian populations seems likely. Terrestrial pesticide exposure might be underestimated as a driver of their decline calling for more attention in conservation efforts and the risk assessment procedures in place do not protect this vanishing animal group.
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Leung, Grace Tak Yu; Fung, Ada Wai Tung; Tam, Cindy Woon Chi; Lui, Victor Wing Cheong; Chiu, Helen Fung Kum; Chan, Wai Man; Lam, Linda Chiu Wa
2011-01-01
This study examines the association between late-life leisure activity participation and global cognitive decline in community-dwelling elderly Chinese in Hong Kong. Five hundred and five participants, not clinically demented at the baseline, were analysed in the follow-up study of a population-based community survey among Hong Kong Chinese aged 60 and over. Information regarding leisure activity participation, global cognitive function and important sociodemographic variables was collected. Late life leisure activity profiles were classified into intellectual, social, physical and recreational categories, and were measured by total hours per week, total frequency and total number of subtypes. Multivariate logistic regression analyses were used to evaluate the association between leisure activity participation at the baseline and the incidence of global cognitive decline at the 22-month follow-up. The incidence of global cognitive decline was defined as a one-point drop in z-score of the Cantonese version of the mini-mental state examination (CMMSE). At the follow-up, a higher level of participation in intellectual activities was significantly associated with a lower incidence of global cognitive decline as measured by both the total hours per week (multivariate-adjusted OR 0.97 (95% CI 0.94-0.99, p=0.003)), and the total number of subtypes (multivariate-adjusted OR 0.74 (95% CI 0.58-0.95, p=0.018)). A higher level of late-life intellectual activity participation was associated with less global cognitive decline among community-dwelling elderly Chinese in Hong Kong. Copyright © 2010 John Wiley & Sons, Ltd.
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Rising trade, declining stocks: The global gugul (Commiphora wightii) trade.
Cunningham, A B; Brinckmann, J A; Kulloli, R N; Schippmann, U
2018-05-07
Commiphora wightii is exploited in India and Pakistan for an oleo-resin (gum guggul) traditionally used in Ayurvedic, Siddha and Unani medical systems. Processed C. wightii oleo-resin products are exported from India to 42 countries, including re-export to Pakistan, for anti-inflammatory use and as an anti-inflammatory and an anti-obesity treatment considered to lower cholesterol and lipid levels. The C. wightii export trade has particular relevance to the European Union because Belgium, France, Germany, Hungary, Italy, the Netherlands, and United Kingdom are importing countries. Demand and prices for C. wightii oleo-resin are increasing and wild stocks of C. wightii are in decline. The overexploitation of C. wightii after tapping for its commercially valuable oleo-resin is not a new problem, however, but one that has existed for over 50 years. Lopping and chopping trees to extract C. wightii oleo-resin has had a devastating impact on C. wightii populations since the 1960's. The aim of this study was to review the sustainability of the global trade in C. wightii oleo-resin. This included reviewing studies on resin tapping methods and the impacts of wild harvest on C. wightii populations in India and Pakistan. Firstly, we reviewed studies on impacts of C. wightii oleo-resin harvest and on the policy responses taken in relation to harvest and trade in C. wightii oleo-resin. Secondly, we reviewed studies on C. wightii cultivation. Thirdly, global trade data for C. wightii were analyzed. Destructive harvest to obtain the gum is the major threat facing this species. C. wightii populations are also fragmented by habitat loss through clearing for farming. Cutting and lopping in order to extract the medicinal gum are a major threat to C. wightii populations, as is poor recruitment due to grazing by livestock. As a result of over-exploitation, C. wightii oleo-resin production has declined in India. In Gujarat, a key production area, the decline over a 50-year period has
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Directory of Open Access Journals (Sweden)
S. Ruggunan
2010-12-01
Full Text Available Purpose: The purpose of this article is to investigate the ways in which states are still significant actors in creating and shaping the nature and characteristics of global labour markets. My argument is demonstrated through an empirical case study of the global labour market for British seafarers. Problem Investigated: The last 30 years has witnessed a decimation of the number of employed British seafarers, particularly at lower rank levels, such as ratings. I contend that despite Britain's long and rich maritime history, the British state has not acted meaningfully to reverse the decline of British seafarers. The lack of meaningful action I contend is an attempt to crew British owned ships with cheaper seafaring labour from Asia, particularly south east Asia. In so doing the British state has contributed to the decline of a once thriving labour market. There has simultaneously been an upsurge in the employment of seafarers of other nationalities, and thus the creation of new labour markets in countries such as the Philippines. This paper is an attempt to understand some of the factors responsible for the decline of the British labour market for seafarers. Methodology and Approach: This paper is the outcome of a larger qualitative study undertaken for my doctoral thesis in industrial sociology which examined the transformation of the global labour market for South African, Filipino and British seafarers. The methodology consists of in depth interviews with maritime officials and trade union leaders. These were conducted in person in London, United Kingdom between 2005 and 2008. These interviews are supported by extensive literature and documentary research, to validate, support and test claims made by my interviewees. Implications and Value of the Research: The theoretical contribution of this paper is to reinsert the state more critically into the literature on labour markets. Empirically, seafaring labour markets are largely ignored by the
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Chen, S; Honda, T; Narazaki, K; Chen, T; Kishimoto, H; Haeuchi, Y; Kumagai, S
2018-01-01
To assess the relationship between physical frailty and subsequent decline in global cognitive function in the non-demented elderly. A prospective population-based study in a west Japanese suburban town, with two-year follow-up. Community-dwellers aged 65 and older without placement in long-term care, and not having a history of dementia, Parkinson's disease and depression at baseline, who participated in the cohort of the Sasaguri Genkimon Study and underwent follow-up assessments two years later (N = 1,045). Global cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Physical frailty was identified according to the following five components: weight loss, low grip strength, exhaustion, slow gait speed and low physical activities. Linear regression models were used to examine associations between baseline frailty status and the MoCA scores at follow-up. Logistic regression models were used to estimate the risk of cognitive decline (defined as at least two points decrease of MoCA score) according to baseline frailty status. Seven hundred and eight non-demented older adults were included in the final analyses (mean age: 72.6 ± 5.5 years, male 40.3%); 5.8% were frail, and 40.8% were prefrail at baseline. One hundred and fifty nine (22.5%) participants experienced cognitive decline over two years. After adjustment for baseline MoCA scores and all confounders, being frail at baseline was significantly associated with a decline of 1.48 points (95% confidence interval [CI], -2.37 to -0.59) in MoCA scores, as compared with non-frailty. Frail persons were over two times more likely to experience cognitive decline (adjusted odds ratio 2.28; 95% CI, 1.02 to 5.08), compared to non-frail persons. Physical frailty is associated with longitudinal decline in global cognitive function in the non-demented older adults over a period of two years. Physically frail older community-dwellers should be closely monitored for cognitive decline that can be
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Declining vulnerability to river floods and the global benefits of adaptation.
Jongman, Brenden; Winsemius, Hessel C; Aerts, Jeroen C J H; Coughlan de Perez, Erin; van Aalst, Maarten K; Kron, Wolfgang; Ward, Philip J
2015-05-05
The global impacts of river floods are substantial and rising. Effective adaptation to the increasing risks requires an in-depth understanding of the physical and socioeconomic drivers of risk. Whereas the modeling of flood hazard and exposure has improved greatly, compelling evidence on spatiotemporal patterns in vulnerability of societies around the world is still lacking. Due to this knowledge gap, the effects of vulnerability on global flood risk are not fully understood, and future projections of fatalities and losses available today are based on simplistic assumptions or do not include vulnerability. We show for the first time (to our knowledge) that trends and fluctuations in vulnerability to river floods around the world can be estimated by dynamic high-resolution modeling of flood hazard and exposure. We find that rising per-capita income coincided with a global decline in vulnerability between 1980 and 2010, which is reflected in decreasing mortality and losses as a share of the people and gross domestic product exposed to inundation. The results also demonstrate that vulnerability levels in low- and high-income countries have been converging, due to a relatively strong trend of vulnerability reduction in developing countries. Finally, we present projections of flood losses and fatalities under 100 individual scenario and model combinations, and three possible global vulnerability scenarios. The projections emphasize that materialized flood risk largely results from human behavior and that future risk increases can be largely contained using effective disaster risk reduction strategies.
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Long-term decline of global atmospheric ethane concentrations and implications for methane.
Simpson, Isobel J; Sulbaek Andersen, Mads P; Meinardi, Simone; Bruhwiler, Lori; Blake, Nicola J; Helmig, Detlev; Rowland, F Sherwood; Blake, Donald R
2012-08-23
After methane, ethane is the most abundant hydrocarbon in the remote atmosphere. It is a precursor to tropospheric ozone and it influences the atmosphere's oxidative capacity through its reaction with the hydroxyl radical, ethane's primary atmospheric sink. Here we present the longest continuous record of global atmospheric ethane levels. We show that global ethane emission rates decreased from 14.3 to 11.3 teragrams per year, or by 21 per cent, from 1984 to 2010. We attribute this to decreasing fugitive emissions from ethane's fossil fuel source--most probably decreased venting and flaring of natural gas in oil fields--rather than a decline in its other major sources, biofuel use and biomass burning. Ethane's major emission sources are shared with methane, and recent studies have disagreed on whether reduced fossil fuel or microbial emissions have caused methane's atmospheric growth rate to slow. Our findings suggest that reduced fugitive fossil fuel emissions account for at least 10-21 teragrams per year (30-70 per cent) of the decrease in methane's global emissions, significantly contributing to methane's slowing atmospheric growth rate since the mid-1980s.
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The global decline of cheetah Acinonyx jubatus and what it means for conservation.
Durant, Sarah M; Mitchell, Nicholas; Groom, Rosemary; Pettorelli, Nathalie; Ipavec, Audrey; Jacobson, Andrew P; Woodroffe, Rosie; Böhm, Monika; Hunter, Luke T B; Becker, Matthew S; Broekhuis, Femke; Bashir, Sultana; Andresen, Leah; Aschenborn, Ortwin; Beddiaf, Mohammed; Belbachir, Farid; Belbachir-Bazi, Amel; Berbash, Ali; Brandao de Matos Machado, Iracelma; Breitenmoser, Christine; Chege, Monica; Cilliers, Deon; Davies-Mostert, Harriet; Dickman, Amy J; Ezekiel, Fabiano; Farhadinia, Mohammad S; Funston, Paul; Henschel, Philipp; Horgan, Jane; de Iongh, Hans H; Jowkar, Houman; Klein, Rebecca; Lindsey, Peter Andrew; Marker, Laurie; Marnewick, Kelly; Melzheimer, Joerg; Merkle, Johnathan; M'soka, Jassiel; Msuha, Maurus; O'Neill, Helen; Parker, Megan; Purchase, Gianetta; Sahailou, Samaila; Saidu, Yohanna; Samna, Abdoulkarim; Schmidt-Küntzel, Anne; Selebatso, Eda; Sogbohossou, Etotépé A; Soultan, Alaaeldin; Stone, Emma; van der Meer, Esther; van Vuuren, Rudie; Wykstra, Mary; Young-Overton, Kim
2017-01-17
Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes.
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MAS NMR of HIV-1 protein assemblies
Suiter, Christopher L.; Quinn, Caitlin M.; Lu, Manman; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana
2015-04-01
The negative global impact of the AIDS pandemic is well known. In this perspective article, the utility of magic angle spinning (MAS) NMR spectroscopy to answer pressing questions related to the structure and dynamics of HIV-1 protein assemblies is examined. In recent years, MAS NMR has undergone major technological developments enabling studies of large viral assemblies. We discuss some of these evolving methods and technologies and provide a perspective on the current state of MAS NMR as applied to the investigations into structure and dynamics of HIV-1 assemblies of CA capsid protein and of Gag maturation intermediates.
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Are snake populations in widespread decline?
Reading, C J; Luiselli, L M; Akani, G C; Bonnet, X; Amori, G; Ballouard, J M; Filippi, E; Naulleau, G; Pearson, D; Rugiero, L
2010-12-23
Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined sharply over the same relatively short period of time with five remaining stable and one showing signs of a marginal increase. Although the causes of these declines are currently unknown, we suspect that they are multi-faceted (such as habitat quality deterioration, prey availability), and with a common cause, e.g. global climate change, at their root.
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Who fears and who welcomes population decline?
Directory of Open Access Journals (Sweden)
Hendrik P. Van Dalen
2011-08-01
Full Text Available European countries are experiencing population decline and the tacit assumption in most analyses is that the decline may have detrimental welfare effects. In this paper we use a survey among the population in the Netherlands to discover whether population decline is always met with fear. A number of results stand out: population size preferences differ by geographic proximity: at a global level the majority of respondents favors a (global population decline, but closer to home one supports a stationary population. Population decline is clearly not always met with fear: 31 percent would like the population to decline at the national level and they generally perceive decline to be accompanied by immaterial welfare gains (improvement environment as well as material welfare losses (tax increases, economic stagnation. In addition to these driving forces it appears that the attitude towards immigrants is a very strong determinant at all geographical levels: immigrants seem to be a stronger fear factor than population decline.
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Recent decline in the global land evapotranspiration trend due to limited moisture supply.
Jung, Martin; Reichstein, Markus; Ciais, Philippe; Seneviratne, Sonia I; Sheffield, Justin; Goulden, Michael L; Bonan, Gordon; Cescatti, Alessandro; Chen, Jiquan; de Jeu, Richard; Dolman, A Johannes; Eugster, Werner; Gerten, Dieter; Gianelle, Damiano; Gobron, Nadine; Heinke, Jens; Kimball, John; Law, Beverly E; Montagnani, Leonardo; Mu, Qiaozhen; Mueller, Brigitte; Oleson, Keith; Papale, Dario; Richardson, Andrew D; Roupsard, Olivier; Running, Steve; Tomelleri, Enrico; Viovy, Nicolas; Weber, Ulrich; Williams, Christopher; Wood, Eric; Zaehle, Sönke; Zhang, Ke
2010-10-21
More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land−a key diagnostic criterion of the effects of climate change and variability−remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Niño event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science.
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International Nuclear Information System (INIS)
Tulleken, C.A.F.; Rijen, P.C. van; Berkelbach van der Sprenkel, J.W.; Verheul, H.B.; Echteld, C.J.A. van; Balasz, R.; Lewis, P.
1991-01-01
Global forebrain ischemia was induced in the rat model by occlusion of both carotid arteries and subsequent lowering of the blood pressure. After 30 minutes of ischemia reperfusion was established. Using 1H and 31P NMR spectroscopy tissue pH values, lactate production, cellular energy index and N-acetyl-aspartate content were determined. The survival rates and histological damage were counted. (author)
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Are snake populations in widespread decline?
Reading, C. J.; Luiselli, L. M.; Akani, G. C.; Bonnet, X.; Amori, G.; Ballouard, J. M.; Filippi, E.; Naulleau, G.; Pearson, D.; Rugiero, L.
2010-01-01
Long-term studies have revealed population declines in fishes, amphibians, reptiles, birds and mammals. In birds, and particularly amphibians, these declines are a global phenomenon whose causes are often unclear. Among reptiles, snakes are top predators and therefore a decline in their numbers may have serious consequences for the functioning of many ecosystems. Our results show that, of 17 snake populations (eight species) from the UK, France, Italy, Nigeria and Australia, 11 have declined ...
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The global financial crisis and neighborhood decline
Zwiers, Merle; Bolt, Gideon; Van Ham, Maarten; Van Kempen, Ronald
2016-01-01
Neighborhood decline is a complex and multidimensional process. National and regional variations in economic and political structures (including varieties in national welfare state arrangements), combined with differences in neighborhood history, development, and population composition, make it
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Automated sequence-specific protein NMR assignment using the memetic algorithm MATCH
International Nuclear Information System (INIS)
Volk, Jochen; Herrmann, Torsten; Wuethrich, Kurt
2008-01-01
MATCH (Memetic Algorithm and Combinatorial Optimization Heuristics) is a new memetic algorithm for automated sequence-specific polypeptide backbone NMR assignment of proteins. MATCH employs local optimization for tracing partial sequence-specific assignments within a global, population-based search environment, where the simultaneous application of local and global optimization heuristics guarantees high efficiency and robustness. MATCH thus makes combined use of the two predominant concepts in use for automated NMR assignment of proteins. Dynamic transition and inherent mutation are new techniques that enable automatic adaptation to variable quality of the experimental input data. The concept of dynamic transition is incorporated in all major building blocks of the algorithm, where it enables switching between local and global optimization heuristics at any time during the assignment process. Inherent mutation restricts the intrinsically required randomness of the evolutionary algorithm to those regions of the conformation space that are compatible with the experimental input data. Using intact and artificially deteriorated APSY-NMR input data of proteins, MATCH performed sequence-specific resonance assignment with high efficiency and robustness
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Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis.
Carvalho, Tamilie; Becker, C Guilherme; Toledo, Luís Felipe
2017-02-08
The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus Batrachochytrium dendrobatidis ( Bd ) is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several Bd lineages predating the reported declines raised the hypothesis that a hypervirulent Bd genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between Bd and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between Bd and declines would support the hypothesis that Brazilian amphibians were not adapted to Bd prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of Bd emergence. Alternatively, a lack of spatio-temporal association between Bd and frog declines would indicate an evolution of host resistance in Brazilian frogs predating Bd 's global emergence , further supporting Brazil as the potential origin of the Bd panzootic. Here, we Bd -screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal Bd data with areas of historical amphibian declines. We detected an increase in the proportion of Bd -infected tadpoles during the peak of amphibian declines (1979-1987). We also found that clusters of Bd -positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of Bd globally. © 2017 The Author(s).
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Historical amphibian declines and extinctions in Brazil linked to chytridiomycosis
Carvalho, Tamilie; Becker, C. Guilherme
2017-01-01
The recent increase in emerging fungal diseases is causing unprecedented threats to biodiversity. The origin of spread of the frog-killing fungus Batrachochytrium dendrobatidis (Bd) is a matter of continued debate. To date, the historical amphibian declines in Brazil could not be attributed to chytridiomycosis; the high diversity of hosts coupled with the presence of several Bd lineages predating the reported declines raised the hypothesis that a hypervirulent Bd genotype spread from Brazil to other continents causing the recent global amphibian crisis. We tested for a spatio-temporal overlap between Bd and areas of historical amphibian population declines and extinctions in Brazil. A spatio-temporal convergence between Bd and declines would support the hypothesis that Brazilian amphibians were not adapted to Bd prior to the reported declines, thus weakening the hypothesis that Brazil was the global origin of Bd emergence. Alternatively, a lack of spatio-temporal association between Bd and frog declines would indicate an evolution of host resistance in Brazilian frogs predating Bd's global emergence, further supporting Brazil as the potential origin of the Bd panzootic. Here, we Bd-screened over 30 000 museum-preserved tadpoles collected in Brazil between 1930 and 2015 and overlaid spatio-temporal Bd data with areas of historical amphibian declines. We detected an increase in the proportion of Bd-infected tadpoles during the peak of amphibian declines (1979–1987). We also found that clusters of Bd-positive samples spatio-temporally overlapped with most records of amphibian declines in Brazil's Atlantic Forest. Our findings indicate that Brazil is post epizootic for chytridiomycosis and provide another piece to the puzzle to explain the origin of Bd globally. PMID:28179514
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Habitat split and the global decline of amphibians.
Becker, Carlos Guilherme; Fonseca, Carlos Roberto; Haddad, Célio Fernando Baptista; Batista, Rômulo Fernandes; Prado, Paulo Inácio
2007-12-14
The worldwide decline in amphibians has been attributed to several causes, especially habitat loss and disease. We identified a further factor, namely "habitat split"-defined as human-induced disconnection between habitats used by different life history stages of a species-which forces forest-associated amphibians with aquatic larvae to make risky breeding migrations between suitable aquatic and terrestrial habitats. In the Brazilian Atlantic Forest, we found that habitat split negatively affects the richness of species with aquatic larvae but not the richness of species with terrestrial development (the latter can complete their life cycle inside forest remnants). This mechanism helps to explain why species with aquatic larvae have the highest incidence of population decline. These findings reinforce the need for the conservation and restoration of riparian vegetation.
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Exploring the Global Decline of Music Education
Aróstegui, José Luis
2016-01-01
This article seeks to explain the disjuncture between the decline of music education in schools and the importance music has in popular youth culture and in creativity within the new knowledge economy. The data discussed in this article have been derived from analyses of major documents on curriculum reform as well as e-mail responses from music…
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International Nuclear Information System (INIS)
Kneeland, J.B.; Lee, B.C.P.; Whalen, J.P.; Knowles, R.J.R.; Cahill, P.T.
1984-01-01
Although still quite new, NMR imaging has already emerged as a safe, noninvasive, painless, and effective diagnostic modality requiring no ionizing radiation. Also, NMR appears already to have established itself as the method of choice for the examination of the brain spinal cord (excluding herniated disks). Another area in which NMR excels is in the examination of the pelvis. The use of surface coils offers the promise of visualizing structures with resolution unobtainable by any other means. In addition, NMR, with its superb visualization of vascular structures and potential ability to measure flow, may soon revolutionize the diagnosis of cardiovascular disease. Finally, NMR, through biochemically and physiologically based T/sub 1/ and T/sub 2/ indices or through spectroscopy, may provide a means of monitoring therapeutic response so as to permit tailoring of treatment to the individual patient. In short, NMR is today probably at the same stage as the x-ray was in Roentgen's day
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Forest decline of the world: A linkage with air pollution and global ...
African Journals Online (AJOL)
STORAGESEVER
2009-12-29
Dec 29, 2009 ... forests of Central Europe, Eastern North America and the Pacific ... permit the reader to have general idea about forest decline. DEFINITION OF FOREST DECLINE. Definition of forest decline is not founded on a universal.
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Amphibian and reptile declines over 35 years at La Selva, Costa Rica.
Whitfield, Steven M; Bell, Kristen E; Philippi, Thomas; Sasa, Mahmood; Bolaños, Federico; Chaves, Gerardo; Savage, Jay M; Donnelly, Maureen A
2007-05-15
Amphibians stand at the forefront of a global biodiversity crisis. More than one-third of amphibian species are globally threatened, and over 120 species have likely suffered global extinction since 1980. Most alarmingly, many rapid declines and extinctions are occurring in pristine sites lacking obvious adverse effects of human activities. The causes of these "enigmatic" declines remain highly contested. Still, lack of long-term data on amphibian populations severely limits our understanding of the distribution of amphibian declines, and therefore the ultimate causes of these declines. Here, we identify a systematic community-wide decline in populations of terrestrial amphibians at La Selva Biological Station, a protected old-growth lowland rainforest in lower Central America. We use data collected over 35 years to show that population density of all species of terrestrial amphibians has declined by approximately 75% since 1970, and we show identical trends for all species of common reptiles. The trends we identify are neither consistent with recent emergence of chytridiomycosis nor the climate-linked epidemic hypothesis, two leading putative causes of enigmatic amphibian declines. Instead, our data suggest that declines are due to climate-driven reductions in the quantity of standing leaf litter, a critical microhabitat for amphibians and reptiles in this assemblage. Our results raise further concerns about the global persistence of amphibian populations by identifying widespread declines in species and habitats that are not currently recognized as susceptible to such risks.
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Economic reasons behind the decline of the Ottoman empire
Duranoglu, Erkut; Okutucu, Guzide
2009-01-01
This study addresses the economic reasons of the decline and fall of the Ottoman Empire. On the contrary to the previous researches, by undertaking both global and domestic developments, the paper examines the decline of the empire from an economical point of perspective. Although international developments such as industrialization in European countries, pressure on the Ottomans in terms of integrating with the world economy, global economic factors like depressions and war...
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AMPHIBIAN DECLINE, ULTRAVIOLET RADIATION AND LOCAL POPULATION ADAPTATION
Amphibian population declines have been noted on both local and global scales. Causes for these declines are unknown although many hypotheses have been offered. In areas adjacent to human development, loss of habitat is a fairly well accepted cause. However in isolated, seemingl...
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High resolution NMR spectroscopy of physiological fluids: from metabolism to physiology
International Nuclear Information System (INIS)
Vion-Dury, J.; Nicoli, F.; Torri, G.; Torri, J.; Kriat, M.; Sciaky, M.; Davin, A.; Viout, P.; Confort-Gouny, S.; Cozzone, P.J.
1992-01-01
High resolution NMR spectroscopy of physiological fluids provides quantitative, qualitative and dynamic information on the metabolic status of the interstitial and plasma compartments under a variety of pathophysiological conditions. The simultaneous detection and quantitation by NMR spectroscopy of numerous compounds of the intermediary metabolism offers a new insight in the understanding of the 'milieu interieur'.NMR spectroscopy of physiological fluids offers a unique way to define and monitor the global metabolic homeostasis in humans. The development of this analytical approach is still limited by the scarcity of pluridisciplinary teams able to fully exploit the wealth of information present on the NMR spectrum of a fluid. While application in pharmacology and toxicology is already established, the main areas of current development are cancer, hereditary metabolic disorders, organ transplantation and neurological diseases
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Family planning and fertility decline: a global overview.
Tabah, L
1977-01-01
Family planning and development policy concerns are not incompatible. The emphasis on development policies at the 1974 World Population Conference at Bucharest did not mean that world governments had lost interest in the population and family planning issue. Although worldwide attitudes toward family planning have become more and more favorable, this has not yet meant great impact on world demographic trends. The "inertia factor," i.e., the effects of high birthrates in the previous generation, will camouflage declining birthrates for some time to come. The trend of fertility reduction which was perceptible only among small populations a few years ago is also becoming manifest in larger Third World countries. Mortality rate declines have slowed down but there is no rising mortality due to starvation in any country. At present, food demand exceeds availability for 80% of the Third World population. It is predicted that the food deficit will increase 70% by the year 2000.
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NMR data-driven structure determination using NMR-I-TASSER in the CASD-NMR experiment
Energy Technology Data Exchange (ETDEWEB)
Jang, Richard [Huazhong University of Science and Technology, School of Software Engineering (China); Wang, Yan [Huazhong University of Science and Technology, School of Life Science and Technology (China); Xue, Zhidong, E-mail: zdxue@hust.edu.cn [Huazhong University of Science and Technology, School of Software Engineering (China); Zhang, Yang, E-mail: zhng@umich.edu [University of Michigan, Department of Computational Medicine and Bioinformatics (United States)
2015-08-15
NMR-I-TASSER, an adaption of the I-TASSER algorithm combining NMR data for protein structure determination, recently joined the second round of the CASD-NMR experiment. Unlike many molecular dynamics-based methods, NMR-I-TASSER takes a molecular replacement-like approach to the problem by first threading the target through the PDB to identify structural templates which are then used for iterative NOE assignments and fragment structure assembly refinements. The employment of multiple templates allows NMR-I-TASSER to sample different topologies while convergence to a single structure is not required. Retroactive and blind tests of the CASD-NMR targets from Rounds 1 and 2 demonstrate that even without using NOE peak lists I-TASSER can generate correct structure topology with 15 of 20 targets having a TM-score above 0.5. With the addition of NOE-based distance restraints, NMR-I-TASSER significantly improved the I-TASSER models with all models having the TM-score above 0.5. The average RMSD was reduced from 5.29 to 2.14 Å in Round 1 and 3.18 to 1.71 Å in Round 2. There is no obvious difference in the modeling results with using raw and refined peak lists, indicating robustness of the pipeline to the NOE assignment errors. Overall, despite the low-resolution modeling the current NMR-I-TASSER pipeline provides a coarse-grained structure folding approach complementary to traditional molecular dynamics simulations, which can produce fast near-native frameworks for atomic-level structural refinement.
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Status and trends of amphibian declines and extinctions worldwide.
Stuart, Simon N; Chanson, Janice S; Cox, Neil A; Young, Bruce E; Rodrigues, Ana S L; Fischman, Debra L; Waller, Robert W
2004-12-03
The first global assessment of amphibians provides new context for the well-publicized phenomenon of amphibian declines. Amphibians are more threatened and are declining more rapidly than either birds or mammals. Although many declines are due to habitat loss and overutilization, other, unidentified processes threaten 48% of rapidly declining species and are driving species most quickly to extinction. Declines are nonrandom in terms of species' ecological preferences, geographic ranges, and taxonomic associations and are most prevalent among Neotropical montane, stream-associated species. The lack of conservation remedies for these poorly understood declines means that hundreds of amphibian species now face extinction.
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Global analysis of 1H-NMR spectra of serum is an appealing approach for the rapid detection of cancer. To evaluate the usefulness of this method in distinguishing between mammary tumor-bearing mice and healthy controls, we conducted 1H-NMR metabonomic analyses on serum samples ob...
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Mapping Global Potential Risk of Mango Sudden Decline Disease Caused by Ceratocystis fimbriata
Oliveira, Leonardo S. S.; Alfenas, Acelino C.; Neven, Lisa G.; Al-Sadi, Abdullah M.
2016-01-01
The Mango Sudden Decline (MSD), also referred to as Mango Wilt, is an important disease of mango in Brazil, Oman and Pakistan. This fungus is mainly disseminated by the mango bark beetle, Hypocryphalus mangiferae (Stebbing), by infected plant material, and the infested soils where it is able to survive for long periods. The best way to avoid losses due to MSD is to prevent its establishment in mango production areas. Our objectives in this study were to: (1) predict the global potential distribution of MSD, (2) identify the mango growing areas that are under potential risk of MSD establishment, and (3) identify climatic factors associated with MSD distribution. Occurrence records were collected from Brazil, Oman and Pakistan where the disease is currently known to occur in mango. We used the correlative maximum entropy based model (MaxEnt) algorithm to assess the global potential distribution of MSD. The MaxEnt model predicted suitable areas in countries where the disease does not already occur in mango, but where mango is grown. Among these areas are the largest mango producers in the world including India, China, Thailand, Indonesia, and Mexico. The mean annual temperature, precipitation of coldest quarter, precipitation seasonality, and precipitation of driest month variables contributed most to the potential distribution of MSD disease. The mango bark beetle vector is known to occur beyond the locations where MSD currently exists and where the model predicted suitable areas, thus showing a high likelihood for disease establishment in areas predicted by our model. Our study is the first to map the potential risk of MSD establishment on a global scale. This information can be used in designing strategies to prevent introduction and establishment of MSD disease, and in preparation of efficient pest risk assessments and monitoring programs. PMID:27415625
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Viant, Mark R; Pincetich, Christopher A; Hinton, David E; Tjeerdema, Ronald S
2006-03-10
Changes in metabolism of Japanese medaka (Oryzias latipes) embryos exposed to dinoseb (2-sec-butyl-4,6-dinitrophenol), a substituted dinitrophenol herbicide, were determined by in vivo (31)P NMR, high-pressure liquid chromatography (HPLC)-UV, and (1)H NMR metabolomics. ATP and phosphocreatine (PCr) metabolism were characterized within intact embryos by in vivo (31)P NMR; concentrations of ATP, GTP, ADP, GDP, AMP and PCr were determined by HPLC-UV; and changes in numerous polar metabolites were characterized by (1)H NMR-based metabolomics. Rangefinding exposures determined two sublethal doses of dinoseb, 50 and 75 ppb, in which embryos survived from 1-day post fertilization (DPF) through the duration of embryogenesis. In vivo (31)P NMR data were acquired from 900 embryos in 0, 50, and 75 ppb dinoseb at 14, 62, and 110 h (n = 6 groups) after initiation of exposure. After 110 h, embryos were observed for normal development and hatching success, then either preserved in 10% formalin for growth analysis or flash frozen and extracted for HPLC-UV and (1)H NMR analysis. Dinoseb exposure at both concentrations resulted in significant declines in [ATP] and [PCr] at 110 h as measured by in vivo (31)P NMR (p fashion. Metabolic effects measured by in vivo (31)P NMR showed a significant increase in orthophosphate levels (P(i); p < 0.05), and significant decreases in [ATP], [PCr] and the PCr/P(i) ratio (p < 0.05). Metabolomics revealed a dose-response relationship between dinoseb and endogenous metabolite changes, with both dinoseb concentrations producing significantly different metabolic profiles from controls (p < 0.05). Metabolic changes included decreased concentrations of ATP, PCr, alanine and tyrosine, and increased concentrations of lactate with medaka embryotoxicity. This study demonstrated that medaka embryos respond to dinoseb with significant changes in metabolism, reduced growth and heart rates, and increased abnormal development and post-exposure mortality. All
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Action of iloprost and PGE1 on global ischemic and reperfused myocardium: a 31P-NMR-study.
Pissarek, M; Gründer, W; Keller, T; Goos, H; Mest, H J; Krause, E G
1988-01-01
The influence of iloprost, PGE1 and of the combined application of iloprost and PGE1 on high energy phosphate contents was investigated in isolated rat hearts perfused aerob at 37 degrees C in Langendorff mode. Changes in creatine phosphate, ATP and inorganic phosphate were registered during 20 minutes of global ischemia and 56 minutes of reperfusion with 31P-NMR-spectroscopic methods starting drug application prior to ischemia simultaneously with onset of heart perfusion. Most effective in preservation of high energy phosphates was the combined application of PGE1 and iloprost resulting in a creatine phosphate/inorganic phosphate ratio of 103.2 +/- 30.9% of pre-ischemia values compared to 52.5 +/- 6.1% in control group without drug application 0-5 minutes after onset of reperfusion, 148.8 +/- 24.8% vs 78.8 +/- 15.2% at 6-11 minutes of reperfusion and 116.6 +/- 16% vs 68.9 +/- 12.7% at 12-17 minutes of reperfusion. The same trend was observed employing ATP/inorganic phosphate ratio. The improved energy state in reperfused hearts following application of PGE1 and iloprost in combination is presumed to be supported by a reduction of the loss of high energy phosphates (HEP) during global ischemia and by a cytoprotective effect of iloprost immediately after starting reperfusion.
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Illegal killing for ivory drives global decline in African elephants.
Wittemyer, George; Northrup, Joseph M; Blanc, Julian; Douglas-Hamilton, Iain; Omondi, Patrick; Burnham, Kenneth P
2014-09-09
Illegal wildlife trade has reached alarming levels globally, extirpating populations of commercially valuable species. As a driver of biodiversity loss, quantifying illegal harvest is essential for conservation and sociopolitical affairs but notoriously difficult. Here we combine field-based carcass monitoring with fine-scale demographic data from an intensively studied wild African elephant population in Samburu, Kenya, to partition mortality into natural and illegal causes. We then expand our analytical framework to model illegal killing rates and population trends of elephants at regional and continental scales using carcass data collected by a Convention on International Trade in Endangered Species program. At the intensively monitored site, illegal killing increased markedly after 2008 and was correlated strongly with the local black market ivory price and increased seizures of ivory destined for China. More broadly, results from application to continental data indicated illegal killing levels were unsustainable for the species between 2010 and 2012, peaking to ∼ 8% in 2011 which extrapolates to ∼ 40,000 elephants illegally killed and a probable species reduction of ∼ 3% that year. Preliminary data from 2013 indicate overharvesting continued. In contrast to the rest of Africa, our analysis corroborates that Central African forest elephants experienced decline throughout the last decade. These results provide the most comprehensive assessment of illegal ivory harvest to date and confirm that current ivory consumption is not sustainable. Further, our approach provides a powerful basis to determine cryptic mortality and gain understanding of the demography of at-risk species.
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Zafeiridis, Andreas; Chatziioannou, Anastasia Chrysovalantou; Sarivasiliou, Haralambos; Kyparos, Antonios; Nikolaidis, Michalis G; Vrabas, Ioannis S; Pechlivanis, Alexandros; Zoumpoulakis, Panagiotis; Baskakis, Constantinos; Dipla, Konstantina; Theodoridis, Georgios A
2016-12-02
The overall metabolic/energetic stress that occurs during an acute bout of exercise is proposed to be the main driving force for long-term training adaptations. Continuous and high-intensity interval exercise protocols (HIIE) are currently prescribed to acquire the muscular and metabolic benefits of aerobic training. We applied 1 H NMR-based metabonomics to compare the overall metabolic perturbation and activation of individual bioenergetic pathways of three popular aerobic exercises matched for effort/strain. Nine men performed continuous, long-interval (3 min), and short-interval (30 s) bouts of exercise under isoeffort conditions. Blood was collected before and after exercise. The multivariate PCA and OPLS-DA models showed a distinct separation of pre- and postexercise samples in three protocols. The two models did not discriminate the postexercise overall metabolic profiles of the three exercise types. Analysis focused on muscle bioenergetic pathways revealed an extensive upregulation of carbohydrate-lipid metabolism and the TCA cycle in all three protocols; there were only a few differences among protocols in the postexercise abundance of molecules when long-interval bouts were performed. In conclusion, continuous and HIIE exercise protocols, when performed with similar effort/strain, induce comparable global metabolic response/stress despite their marked differences in work-bout intensities. This study highlights the importance of NMR metabonomics in comprehensive monitoring of metabolic consequences of exercise training in the blood of athletes and exercising individuals.
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Observed decrease in atmospheric mercury explained by global decline in anthropogenic emissions
Yanxu Zhang,; Daniel J. Jacob,; Hannah M. Horowitz,; Long Chen,; Helen M. Amos,; Krabbenhoft, David P.; Franz Slemr,; Vincent L. St. Louis,; Elsie M. Sunderland,
2015-01-01
Observations of elemental mercury (Hg0) at sites in North America and Europe show large decreases (∼1–2% y−1) from 1990 to present. Observations in background northern hemisphere air, including Mauna Loa Observatory (Hawaii) and CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) aircraft flights, show weaker decreases (inventories indicating flat or increasing emissions over that period. However, the inventories have three major flaws: (i) they do not account for the decline in atmospheric release of Hg from commercial products; (ii) they are biased in their estimate of artisanal and small-scale gold mining emissions; and (iii) they do not properly account for the change in Hg0/HgII speciation of emissions from coal-fired utilities after implementation of emission controls targeted at SO2 and NOx. We construct an improved global emission inventory for the period 1990 to 2010 accounting for the above factors and find a 20% decrease in total Hg emissions and a 30% decrease in anthropogenic Hg0 emissions, with much larger decreases in North America and Europe offsetting the effect of increasing emissions in Asia. Implementation of our inventory in a global 3D atmospheric Hg simulation [GEOS-Chem (Goddard Earth Observing System-Chemistry)] coupled to land and ocean reservoirs reproduces the observed large-scale trends in atmospheric Hg0 concentrations and in HgII wet deposition. The large trends observed in North America and Europe reflect the phase-out of Hg from commercial products as well as the cobenefit from SO2 and NOx emission controls on coal-fired utilities.
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Anti-discrimination Philosophy and the Decline of Post-capitalist Democracies
Directory of Open Access Journals (Sweden)
Dan Pavel
2012-04-01
Full Text Available The author is trying to explain the contrasts existing between the expanding universe of anti-discrimination sanctions and the decline in legitimacy of democracy. The declining legitimacy affects both consolidated democracies, and newborn democracies. Inequality in the USA, but also at global level is illustrated with relevant statistics. The convergence between the crisis of democracy and the financial and economic global crisis is a major social and political threat. At the global level, after the Arab Spring, the third wave of democratization continued, while the quality of democracy substantially diminished. In the newborn Islamic democracies, discrimination against women, Christians, Jews, gay & lesbians, etc. continued, leading to arson, torture and killings.
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Decline and conservation of bumble bees.
Goulson, D; Lye, G C; Darvill, B
2008-01-01
Declines in bumble bee species in the past 60 years are well documented in Europe, where they are driven primarily by habitat loss and declines in floral abundance and diversity resulting from agricultural intensification. Impacts of habitat degradation and fragmentation are likely to be compounded by the social nature of bumble bees and their largely monogamous breeding system, which renders their effective population size low. Hence, populations are susceptible to stochastic extinction events and inbreeding. In North America, catastrophic declines of some bumble bee species since the 1990s are probably attributable to the accidental introduction of a nonnative parasite from Europe, a result of global trade in domesticated bumble bee colonies used for pollination of greenhouse crops. Given the importance of bumble bees as pollinators of crops and wildflowers, steps must be taken to prevent further declines. Suggested measures include tight regulation of commercial bumble bee use and targeted use of environmentally comparable schemes to enhance floristic diversity in agricultural landscapes.
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Understanding Amphibian Declines Through Geographic Approaches
Gallant, Alisa
2006-01-01
Growing concern over worldwide amphibian declines warrants serious examination. Amphibians are important to the proper functioning of ecosystems and provide many direct benefits to humans in the form of pest and disease control, pharmaceutical compounds, and even food. Amphibians have permeable skin and rely on both aquatic and terrestrial ecosystems during different seasons and stages of their lives. Their association with these ecosystems renders them likely to serve as sensitive indicators of environmental change. While much research on amphibian declines has centered on mysterious causes, or on causes that directly affect humans (global warming, chemical pollution, ultraviolet-B radiation), most declines are the result of habitat loss and habitat alteration. Improving our ability to characterize, model, and monitor the interactions between environmental variables and amphibian habitats is key to addressing amphibian conservation. In 2000, the U.S. Geological Survey (USGS) initiated the Amphibian Research and Monitoring Initiative (ARMI) to address issues surrounding amphibian declines.
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International Nuclear Information System (INIS)
Andrew, E.R.
1983-01-01
Since hydrogen is the most abundant element in all living organisms, proton NMR lends itself well as a method of investigation in biology and medicine. NMR imaging has some special advantages as a diagnostic tool: no ionizing radiation is used, it is noninvasive; it provides a safer means of imaging than the use of x-rays, gamma rays, positrons, or heavy ions. In contrast with ultrasound, the radiation penetrates the bony structures without attenuation. In additional to morphological information, NMR imaging provides additional diagnostic insights through relaxation parameters, which are not available from other imaging methods. In the decade since the first primitive NMR images were obtained, the quality of images now obtained approaches those from CT x-ray scanners. Prototype instruments are being constructed for clinical evaluation and the first whole-body scanners are beginning to appear on the market at costs comparable to CT scanners. Primary differences in equipment for conventional NMR and NMR imaging are the much larger aperture magnets that are required for the examination of human subjects and the addition of coils to generate field gradients and facilities for manipulating the gradients. Early results from clinical trials in many parts of the world are encouraging, and in a few years, the usefuleness of this modality of medical imaging to the medical profession in diagnosis and treatment of disease will be defined. 10 figures
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DEFF Research Database (Denmark)
Calcutta, Antonello; Jessen, Christian M; Behrens, Manja Annette
2012-01-01
induced by unfolding of an integral membrane protein, namely TFE-induced unfolding of KcsA solubilized by the n-dodecyl ß-d-maltoside (DDM) surfactant is investigated by the recently introduced GPS-NMR (Global Protein folding State mapping by multivariate NMR) (Malmendal et al., PlosONE 5, e10262 (2010......)) along with dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS). GPS-NMR is used as a tool for fast analysis of the protein unfolding processes upon external perturbation, and DLS and SAXS are used for further structural characterization of the unfolding states. The combination allows...
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International Nuclear Information System (INIS)
Kose, Katsumi; Sato, Kozo; Sugimoto, Hiroshi; Sato, Masataka.
1983-01-01
A brief explanation is made on the imaging methods for a practical diagnostic NMR-CT scanner : A whole-body NMR-CT scanner utilizing a resistive magnet has been developed by Toshiba in cooperation with the Institute for Solid State Physics, the University of Tokyo. Typical NMR-CT images of volunteers and patients obtained in the clinical experiments using this device are presented. Detailed specifications are also shown about the practical NMR-CTs which are to be put on the market after obtaining the government approval. (author)
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John Ralph; Larry L. Landucci
2010-01-01
This chapter will consider the basic aspects and findings of several forms of NMR spectroscopy, including separate discussions of proton, carbon, heteronuclear, and multidimensional NMR. Enhanced focus will be on 13C NMR, because of its qualitative and quantitative importance, followed by NMRâs contributions to our understanding of lignin...
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Medical applications of NMR imaging and NMR spectroscopy with stable isotopes. Summary
International Nuclear Information System (INIS)
Matwiyoff, N.A.
1983-01-01
The current status of NMR imaging and NMR spectroscopy are summarized. For the most part examples from the March 1983 Puerto Rico symposium are used to illustrate the utility of NMR in medicine. 18 refs., 5 figs
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Medical applications of NMR imaging and NMR spectroscopy with stable isotopes. Summary
Energy Technology Data Exchange (ETDEWEB)
Matwiyoff, N.A.
1983-01-01
The current status of NMR imaging and NMR spectroscopy are summarized. For the most part examples from the March 1983 Puerto Rico symposium are used to illustrate the utility of NMR in medicine. 18 refs., 5 figs.
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Verfaillie, Sander C J; Slot, Rosalinde E R; Dicks, Ellen; Prins, Niels D; Overbeek, Jozefien M; Teunissen, Charlotte E; Scheltens, Philip; Barkhof, Frederik; van der Flier, Wiesje M; Tijms, Betty M
2018-03-30
Grey matter network disruptions in Alzheimer's disease (AD) are associated with worse cognitive impairment cross-sectionally. Our aim was to investigate whether indications of a more random network organization are associated with longitudinal decline in specific cognitive functions in individuals with subjective cognitive decline (SCD). We included 231 individuals with SCD who had annually repeated neuropsychological assessment (3 ± 1 years; n = 646 neuropsychological investigations) available from the Amsterdam Dementia Cohort (54% male, age: 63 ± 9, MMSE: 28 ± 2). Single-subject grey matter networks were extracted from baseline 3D-T1 MRI scans and we computed basic network (size, degree, connectivity density) and higher-order (path length, clustering, betweenness centrality, normalized path length [lambda] and normalized clustering [gamma]) parameters at whole brain and/or regional levels. We tested associations of network parameters with baseline and annual cognition (memory, attention, executive functioning, language composite scores, and global cognition [all domains with MMSE]) using linear mixed models, adjusted for age, sex, education, scanner and total gray matter volume. Lower network size was associated with steeper decline in language (β ± SE = 0.12 ± 0.05, p organized grey matter network was associated with a steeper decline of cognitive functioning, possibly indicating the start of cognitive impairment. © 2018 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.
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NMR spectroscopy applied to the eye: Drugs and metabolic studies
Energy Technology Data Exchange (ETDEWEB)
Saether, Oddbjoern
2005-07-01
monitoring of drugs in the eye. HR-MAS H1 NMR spectroscopy proved to be a suitable tool for investigating metabolites in the lens and cornea. Long-term steroid treatment and exposure to ultraviolet-B radiation, known risk factors for cataract development, induced profound metabolic changes in the lens. The major changes were depletion of osmolytes as taurine and inositols as well as significant loss of glutathione. Glutathione has been shown to decline in most cataracts. Unlike the induced lenticular opacities, metabolic changes did not follow any UVB dose-response relationship 7 days post exposure. UVB exposure also caused considerable metabolic alterations in the cornea, with depletion of ascorbate and osmolytes. As an antioxidant, ascorbate is important for ocular UV-protection. Steroid treatment prior to UVB exposure reinforced metabolic changes in the anterior segment of the eye. In the present studies, HR-MAS NMR spectroscopy was implemented for investigating intact tissue samples from the cornea and lens. Moreover a basis was introduced to apply these methods for analysis of corneal and lenticular sections. This is a promising technique for research on eye diseases, enabling metabolic asymmetry within the tissues to be taken into account. (Author)
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NMR spectroscopy applied to the eye: Drugs and metabolic studies
International Nuclear Information System (INIS)
Saether, Oddbjoern
2005-01-01
monitoring of drugs in the eye. HR-MAS H1 NMR spectroscopy proved to be a suitable tool for investigating metabolites in the lens and cornea. Long-term steroid treatment and exposure to ultraviolet-B radiation, known risk factors for cataract development, induced profound metabolic changes in the lens. The major changes were depletion of osmolytes as taurine and inositols as well as significant loss of glutathione. Glutathione has been shown to decline in most cataracts. Unlike the induced lenticular opacities, metabolic changes did not follow any UVB dose-response relationship 7 days post exposure. UVB exposure also caused considerable metabolic alterations in the cornea, with depletion of ascorbate and osmolytes. As an antioxidant, ascorbate is important for ocular UV-protection. Steroid treatment prior to UVB exposure reinforced metabolic changes in the anterior segment of the eye. In the present studies, HR-MAS NMR spectroscopy was implemented for investigating intact tissue samples from the cornea and lens. Moreover a basis was introduced to apply these methods for analysis of corneal and lenticular sections. This is a promising technique for research on eye diseases, enabling metabolic asymmetry within the tissues to be taken into account. (Author)
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NMR imaging and pharmaceutical sciences
International Nuclear Information System (INIS)
Beall, P.T.; Good, W.R.
1986-01-01
Described is the technique of NMR-imaging in diagnostic medicine. Proton and phosphorus NMR in diagnosis of abnormal tissue pathology. Discussed is the value of NMR to the pharmaceutical sciences. NMR may play an important role in monitoring the response of tissues to drugs, determining the localization of drugs, performing real time pharmacokinetics and testing the use of NMR contrast pharmaceuticals
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International Nuclear Information System (INIS)
Schnall, M.D.
1988-01-01
The NMR probe is the intrinsic part of the NMR system which allows transmission of a stimulus to a sample and the reception of a resulting signal from a sample. NMR probes are used in both imaging and spectroscopy. Optimal probe design is important to the production of adequate signal/moise. It is important for anyone using NMR techniques to understand how NMR probes work and how to optimize probe design
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Directory of Open Access Journals (Sweden)
Tantucci C
2012-02-01
Full Text Available Claudio Tantucci, Denise ModinaUnit of Respiratory Medicine, Department of Medical and Surgical Sciences, University of Brescia, Brescia, ItalyAbstract: The landmark study of Fletcher and Peto on the natural history of tobacco smoke-related chronic airflow obstruction suggested that decline in the forced expiratory volume in the first second (FEV1 in chronic obstructive pulmonary disease (COPD is slow at the beginning, becoming faster with more advanced disease. The present authors reviewed spirometric data of COPD patients included in the placebo arms of recent clinical trials to assess the lung function decline of each stage, defined according to the severity of airflow obstruction as proposed by the Global Initiative for Chronic Obstructive Lung Disease (GOLD guidelines. In large COPD populations the mean rate of FEV1 decline in GOLD stages II and III is between 47 and 79 mL/year and 56 and 59 mL/year, respectively, and lower than 35 mL/year in GOLD stage IV. Few data on FEV1 decline are available for GOLD stage I. Hence, the loss of lung function, assessed as expiratory airflow reduction, seems more accelerated and therefore more relevant in the initial phases of COPD. To have an impact on the natural history of COPD, it is logical to look at the effects of treatment in the earlier stages.Keywords: chronic obstructive pulmonary disease, decline, forced expiratory volume in 1 second, FEV1
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Phosphorus NMR of isolated perfused morris hepatomas
International Nuclear Information System (INIS)
Graham, R.A.; Meyer, R.A.; Brown, T.R.; Sauer, L.A.
1986-01-01
The authors are developing techniques for the study of perfused solid tumors by NMR. Tissue-isolated solid hepatomas were grown to 1-2 cm diameter as described previously. The arterial supply was isolated and the tumors perfused (0.5 - 1.0 ml/min) in vitro at 25 C with a 15% suspension of red blood cells in Krebs-Henseliet solution. 31 P-NMR spectra were acquired at 162 MHz in a specially-designed NMR probe using a solenoidal coil. Intracellular pH (monitored from the chemical shift of inorganic phosphate) and ATP levels were stable for up to 6 hrs during perfusion. During 30 min of global ischemia, ATP decreased by 75% and pH fell from 7.0 to 6.7. These changes were reversed by 1 hr reperfusion. In addition to ATP and phosphate, the spectra included a large resonance due to phosphomonoesters, as well as peaks consistent with glycerylphosphocholine, glyceryl-phosphoethanolamine, phosphocreatine, NAD, and UDPG. However, the most novel feature of the spectra was the presence of an unidentified peak in the phosphonate region (+ 16.9 ppm). The peak was not present in spectra of muscle, liver, brain, kidney, or fat tissues excised from the same animals. They are presently attempting to identify the compound that gives rise to this peak and to establish its metabolic origin
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Schober, Daniel; Jacob, Daniel; Wilson, Michael; Cruz, Joseph A; Marcu, Ana; Grant, Jason R; Moing, Annick; Deborde, Catherine; de Figueiredo, Luis F; Haug, Kenneth; Rocca-Serra, Philippe; Easton, John; Ebbels, Timothy M D; Hao, Jie; Ludwig, Christian; Günther, Ulrich L; Rosato, Antonio; Klein, Matthias S; Lewis, Ian A; Luchinat, Claudio; Jones, Andrew R; Grauslys, Arturas; Larralde, Martin; Yokochi, Masashi; Kobayashi, Naohiro; Porzel, Andrea; Griffin, Julian L; Viant, Mark R; Wishart, David S; Steinbeck, Christoph; Salek, Reza M; Neumann, Steffen
2018-01-02
NMR is a widely used analytical technique with a growing number of repositories available. As a result, demands for a vendor-agnostic, open data format for long-term archiving of NMR data have emerged with the aim to ease and encourage sharing, comparison, and reuse of NMR data. Here we present nmrML, an open XML-based exchange and storage format for NMR spectral data. The nmrML format is intended to be fully compatible with existing NMR data for chemical, biochemical, and metabolomics experiments. nmrML can capture raw NMR data, spectral data acquisition parameters, and where available spectral metadata, such as chemical structures associated with spectral assignments. The nmrML format is compatible with pure-compound NMR data for reference spectral libraries as well as NMR data from complex biomixtures, i.e., metabolomics experiments. To facilitate format conversions, we provide nmrML converters for Bruker, JEOL and Agilent/Varian vendor formats. In addition, easy-to-use Web-based spectral viewing, processing, and spectral assignment tools that read and write nmrML have been developed. Software libraries and Web services for data validation are available for tool developers and end-users. The nmrML format has already been adopted for capturing and disseminating NMR data for small molecules by several open source data processing tools and metabolomics reference spectral libraries, e.g., serving as storage format for the MetaboLights data repository. The nmrML open access data standard has been endorsed by the Metabolomics Standards Initiative (MSI), and we here encourage user participation and feedback to increase usability and make it a successful standard.
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Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR.
van der Schot, Gijs; Bonvin, Alexandre M J J
2015-08-01
We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665-1674, 2005b, doi: 10.1021/ja047109h). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27-35, 2013, doi: 10.1007/s10858-013-9762-6), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution.
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Analytical challenges in drug counterfeiting and falsification-The NMR approach.
Holzgrabe, Ulrike; Malet-Martino, Myriam
2011-06-25
Counterfeiting of products is a global problem. As long as clothes, clocks, leather wear, etc. are faked there is no danger, but when it comes to drugs, counterfeiting can be life-threatening. In the last years sub-standard active pharmaceutical ingredients (APIs) were found more often even though the use of the quality-ensuring methods of international pharmacopoeias should have detected additional impurities and the low content of the API. Methods orthogonal to the separating methods used in the pharmacopoeias are necessary to find counterfeits. Beside Raman and NIR spectroscopies as well as powder X-ray analysis, NMR spectroscopy being a primary ratio method of measurement is highly suitable to identify and quantify a drug and its related substances as well as to recognize a drug of sub-standard quality. DOSY experiments are suitable to identify the ingredients of formulations and therefore to identify wrong and/or additional ingredients. This review gives an overview of the application of quantitative NMR spectroscopy and DOSY NMR in anticounterfeiting. Copyright © 2010 Elsevier B.V. All rights reserved.
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Insulin is Differentially Related to Cognitive Decline and Atrophy in Alzheimer’s Disease and Aging
Burns, Jeffrey M.; Honea, Robyn A.; Vidoni, Eric D.; Hutfles, Lewis; Brooks, William M.; Swerdlow, Russell H.
2012-01-01
We assessed the relationship of insulin resistance with cognitive decline and brain atrophy over two years in early Alzheimer’s disease (AD, n=48) and nondemented controls (n=61). Intravenous glucose tolerance tests were conducted at baseline to determine insulin area-under-the-curve (AUC). A standard battery of cognitive tasks and MRI were conducted at baseline and 2-year follow-up. In nondemented controls, higher baseline insulin AUC was associated with 2-year decline in global cognitive performance (beta=−0.36, p=0.005). In early AD, however, higher insulin AUC was associated with less decline in global cognitive performance (beta=0.26, p=0.06), slower global brain atrophy (beta=0.40, p=0.01) and less regional atrophy in the bilateral hippocampi and cingulate cortices. While insulin resistance is associated with cognitive decline in nondemented aging, higher peripheral insulin may have AD-specific benefits or insulin signaling may be affected by systemic physiologic changes associated with AD. PMID:21745566
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Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR
Van Der Schot, Gijs; Bonvin, Alexandre M J J
We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on
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Liu, Haiyan; Garrett, Timothy J; Tayyari, Fariba; Gu, Liwei
2015-11-01
The objective was to investigate the metabolome changes in female rats gavaged with partially purified cranberry procyanidins (PPCP) using (1) H NMR and UHPLC-Q-Orbitrap-HRMS metabolomics approaches, and to identify the contributing metabolites. Twenty-four female Sprague-Dawley rats were randomly separated into two groups and administered PPCP or partially purified apple procyanidins (PPAP) for three times using a 250 mg extracts/kg body weight dose. Plasma was collected 6 h after the last gavage and analyzed using (1) H NMR and UHPLC-Q-Orbitrap-HRMS. No metabolome difference was observed using (1) H NMR metabolomics approach. However, LC-HRMS metabolomics data show that metabolome in the plasma of female rats administered PPCP differed from those gavaged with PPAP. Eleven metabolites were tentatively identified from a total of 36 discriminant metabolic features based on accurate masses and/or product ion spectra. PPCP caused a greater increase of exogenous metabolites including p-hydroxybenzoic acid, phenol, phenol-sulphate, catechol sulphate, 3, 4-dihydroxyphenylvaleric acid, and 4'-O-methyl-(-)-epicatechin-3'-O-beta-glucuronide in rat plasma. Furthermore, the plasma level of O-methyl-(-)-epicatechin-O-glucuronide, 4-hydroxy-5-(hydroxyphenyl)-valeric acid-O-sulphate, 5-(hydroxyphenyl)-ϒ-valerolactone-O-sulphate, 4-hydroxydiphenylamine, and peonidin-3-O-hexose were higher in female rats administered with PPAP. The metabolome changes caused by cranberry procyanidins were revealed using an UHPLC-Q-Orbitrap-HRMS global metabolomics approach. Exogenous and microbial metabolites were the major identified discriminate biomarkers. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Liu, Haiyan; Garrett, Timothy J.; Tayyari, Fariba; Gu, Liwei
2015-01-01
Scope The objective was to investigate the metabolome changes in female rats gavaged with partially purified cranberry procyanidins (PPCP) using 1H NMR and UHPLC-Q-Orbitrap-HRMS metabolomics approaches, and to identify the contributing metabolites. Methods and results Twenty four female Sprague-Dawley rats were randomly separated into two groups and administered PPCP or partially purified apple procyanidins (PPAP) for 3 times using a 250 mg extracts/kg body weight dose. Plasma were collected six hours after the last gavage and analyzed using 1H NMR and UHPLC-Q-Orbitrap-HRMS. No metabolome difference was observed using 1H NMR metabolomics approach. However, LC-HRMS metabolomics data show that metabolome in plasma of female rats administered PPCP differed from those gavaged with PPAP. Eleven metabolites were tentatively identified from a total of 36 discriminant metabolic features based on accurate masses and/or product ion spectra. PPCP caused a greater increase of exogenous metabolites including p-hydroxybenzoic acid, phenol, phenol-sulfate, catechol sulphate, 3, 4-dihydroxyphenylvaleric acid, and 4′-O-methyl-(−)-epicatechin-3′-O-beta-glucuronide in rat plasma. Furthermore, the plasma level of O-methyl-(−)-epicatechin-O-glucuronide, 4-hydroxy-5-(hydroxyphenyl)-valeric acid-O-sulphate, 5-(hydroxyphenyl)-γ-valerolactone-O-sulphate, 4-hydroxydiphenylamine, and peonidin-3-O-hexose were higher in female rats administered with PPAP. Conclusion The metabolome changes caused by cranberry procyanidins were revealed using an UHPLC-Q-Orbitrap-HRMS global metabolomics approach. Exogenous and microbial metabolites were the major identified discriminate biomarkers. PMID:26264887
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Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR
Energy Technology Data Exchange (ETDEWEB)
Schot, Gijs van der [Uppsala University, Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology (Sweden); Bonvin, Alexandre M. J. J., E-mail: a.m.j.j.bonvin@uu.nl [Utrecht University, Faculty of Science – Chemistry, Bijvoet Center for Biomolecular Research (Netherlands)
2015-08-15
We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665–1674, 2005b, doi: 10.1021/ja047109h 10.1021/ja047109h ). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27–35, 2013, doi: 10.1007/s10858-013-9762-6 10.1007/s10858-013-9762-6 ), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution.
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Performance of the WeNMR CS-Rosetta3 web server in CASD-NMR
International Nuclear Information System (INIS)
Schot, Gijs van der; Bonvin, Alexandre M. J. J.
2015-01-01
We present here the performance of the WeNMR CS-Rosetta3 web server in CASD-NMR, the critical assessment of automated structure determination by NMR. The CS-Rosetta server uses only chemical shifts for structure prediction, in combination, when available, with a post-scoring procedure based on unassigned NOE lists (Huang et al. in J Am Chem Soc 127:1665–1674, 2005b, doi: 10.1021/ja047109h 10.1021/ja047109h ). We compare the original submissions using a previous version of the server based on Rosetta version 2.6 with recalculated targets using the new R3FP fragment picker for fragment selection and implementing a new annotation of prediction reliability (van der Schot et al. in J Biomol NMR 57:27–35, 2013, doi: 10.1007/s10858-013-9762-6 10.1007/s10858-013-9762-6 ), both implemented in the CS-Rosetta3 WeNMR server. In this second round of CASD-NMR, the WeNMR CS-Rosetta server has demonstrated a much better performance than in the first round since only converged targets were submitted. Further, recalculation of all CASD-NMR targets using the new version of the server demonstrates that our new annotation of prediction quality is giving reliable results. Predictions annotated as weak are often found to provide useful models, but only for a fraction of the sequence, and should therefore only be used with caution
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Direct Comparison of 19F qNMR and 1H qNMR by Characterizing Atorvastatin Calcium Content
Directory of Open Access Journals (Sweden)
Yang Liu
2016-01-01
Full Text Available Quantitative nuclear magnetic resonance (qNMR is a powerful tool in measuring drug content because of its high speed, sensitivity, and precision. Most of the reports were based on proton qNMR (1H qNMR and only a few fluorine qNMR (19F qNMR were reported. No research has been conducted to directly compare the advantage and disadvantage between these two methods. In the present study, both 19F and 1H qNMR were performed to characterize the content of atorvastatin calcium with the same internal standard. Linearity, precision, and results from two methods were compared. Results showed that 19F qNMR has similar precision and sensitivity to 1H qNMR. Both methods generate similar results compared to mass balance method. Major advantage from 19F qNMR is that the analyte signal is with less or no interference from impurities. 19F qNMR is an excellent approach to quantify fluorine-containing analytes.
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31P NMR spectroscopy of tumors in the evaluation of response to therapy
International Nuclear Information System (INIS)
Sijens, P.E.
1988-01-01
In this thesis the effects of different kinds of therapy on tumour metabolism were investigated by in vivo 31P NMR spectroscopy. From the first five chapters (laboratory-animal studies) it turns out that after radiotherapy as well as after hyperthermy or chemoterapy changes can be observed in the 31P NMR spectra of tumours. In a number of cases a durable decline occurred in the ratio of the high-energetic adenosinephosphate (ATP) and the low-energeic anorganic phosphate, cuased by the mortification of tumourcells. On the other hand, tumour regression after effective chemotherapy resulted in a growth of the ATP/Pi ratio. In one case a temporary drop occurred which could be related to a temporary decrease in tumour perfusion. In anoter case a temporary drop of the ATP/Pi ratio correlated with resistence against treatment with cis-diaminodichoroplatina. In contrast with the changes in ATP/Pi ratio, the changes, after (chemo)therapy, in tumour pH do not seem to be related with the respons of the tumour. The results of the laboratory-animal experiments indicate that in vivo 31P NMR spectroscopy could be applied in the clinic in order to establish betime the response of tumours on therapy. In ch. 6 initial experiences with clinical NMR spectroscopy of human breast cancer are described. The results indicate that by 31P NMR spectroscopy malignant breast tissues can be discerned from normal breast tissues, following radiotherapy and subsequent tumour regression, in the spectrum of the tumorous region an intense PCr signal developed which appeared to reflect a metabolic change in the tumous itself. 177 refs.; 27 figs.; 6 tabs
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Dynamic pulsed-field-gradient NMR
Sørland, Geir Humborstad
2014-01-01
Dealing with the basics, theory and applications of dynamic pulsed-field-gradient NMR NMR (PFG NMR), this book describes the essential theory behind diffusion in heterogeneous media that can be combined with NMR measurements to extract important information of the system being investigated. This information could be the surface to volume ratio, droplet size distribution in emulsions, brine profiles, fat content in food stuff, permeability/connectivity in porous materials and medical applications currently being developed. Besides theory and applications it will provide the readers with background knowledge on the experimental set-ups, and most important, deal with the pitfalls that are numerously present in work with PFG-NMR. How to analyze the NMR data and some important basic knowledge on the hardware will be explained, too.
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Sub-Clinical Cognitive Decline and Resting Cerebral Blood Flow in Middle Aged Men.
Directory of Open Access Journals (Sweden)
Otto Mølby Henriksen
Full Text Available Although dementia is associated with both global and regional cerebral blood flow (CBF changes, little is known about cerebral perfusion in the early pre-clinical stages of cognitive decline preceding overt cognitive dysfunction. The aim of this study was to investigate the association of early sub-clinical cognitive decline with CBF.The study participants were recruited from a cohort of Danish men born in 1953. Based on a regression model we selected men who performed better (Group A, n = 94 and poorer (Group B, n = 95 on cognitive testing at age 57 than expected from testing at age 20. Participants underwent supplementary cognitive testing, blood sampling and MRI including measurements of regional and global CBF.Regional CBF was lower in group B than in group A in the posterior cingulate gyrus and the precuneus. The associations were attenuated when corrected for global atrophy, but remained significant in regions of interest based analysis adjusting for regional gray matter volume and vascular risk factors. No influence of group on global CBF was observed.We conclude that early sub-clinical cognitive decline is associated with reduced perfusion in the precuneus and posterior cingulate gyrus independently of regional atrophy and vascular risk factors, but cannot be statistically separated from an association with global atrophy.
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US forest products in the global economy
Dave N Wear; Jeff Prestemon; Michaela O. Foster
2015-01-01
The United Statesâ shares of global industrial roundwood production and derivative products have declined precipitously since the 1990s. We evaluate the extent of these declines compared with those of major producing countries from 1961 to 2013. We find that the US global share of industrial roundwood peaked at 28% in 1999 but by 2013 was at 17%, with the decline...
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CcpNmr AnalysisAssign: a flexible platform for integrated NMR analysis
International Nuclear Information System (INIS)
Skinner, Simon P.; Fogh, Rasmus H.; Boucher, Wayne; Ragan, Timothy J.; Mureddu, Luca G.; Vuister, Geerten W.
2016-01-01
NMR spectroscopy is an indispensably powerful technique for the analysis of biomolecules under ambient conditions, both for structural- and functional studies. However, in practice the complexity of the technique has often frustrated its application by non-specialists. In this paper, we present CcpNmr version-3, the latest software release from the Collaborative Computational Project for NMR, for all aspects of NMR data analysis, including liquid- and solid-state NMR data. This software has been designed to be simple, functional and flexible, and aims to ensure that routine tasks can be performed in a straightforward manner. We have designed the software according to modern software engineering principles and leveraged the capabilities of modern graphics libraries to simplify a variety of data analysis tasks. We describe the process of backbone assignment as an example of the flexibility and simplicity of implementing workflows, as well as the toolkit used to create the necessary graphics for this workflow. The package can be downloaded from www.ccpn.ac.uk/v3-software/downloads http://www.ccpn.ac.uk/v3-software/downloads and is freely available to all non-profit organisations.
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CcpNmr AnalysisAssign: a flexible platform for integrated NMR analysis
Energy Technology Data Exchange (ETDEWEB)
Skinner, Simon P.; Fogh, Rasmus H. [University of Leicester, Department of Molecular and Cell Biology, Leicester Institute for Structural- and Chemical Biology (United Kingdom); Boucher, Wayne [University of Cambridge, Department of Biochemistry (United Kingdom); Ragan, Timothy J.; Mureddu, Luca G.; Vuister, Geerten W., E-mail: gv29@le.ac.uk [University of Leicester, Department of Molecular and Cell Biology, Leicester Institute for Structural- and Chemical Biology (United Kingdom)
2016-10-15
NMR spectroscopy is an indispensably powerful technique for the analysis of biomolecules under ambient conditions, both for structural- and functional studies. However, in practice the complexity of the technique has often frustrated its application by non-specialists. In this paper, we present CcpNmr version-3, the latest software release from the Collaborative Computational Project for NMR, for all aspects of NMR data analysis, including liquid- and solid-state NMR data. This software has been designed to be simple, functional and flexible, and aims to ensure that routine tasks can be performed in a straightforward manner. We have designed the software according to modern software engineering principles and leveraged the capabilities of modern graphics libraries to simplify a variety of data analysis tasks. We describe the process of backbone assignment as an example of the flexibility and simplicity of implementing workflows, as well as the toolkit used to create the necessary graphics for this workflow. The package can be downloaded from www.ccpn.ac.uk/v3-software/downloads http://www.ccpn.ac.uk/v3-software/downloads and is freely available to all non-profit organisations.
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DEFF Research Database (Denmark)
Niño-Zarazúa, Miguel; Roope, Laurence; Tarp, Finn
2017-01-01
This paper measures trends in global interpersonal inequality during 1975–2010 using data from the most recent version of the World Income Inequality Database (WIID). The picture that emerges using ‘absolute,’ and even ‘centrist’ measures of inequality, is very different from the results obtained...... using standard ‘relative’ inequality measures such as the Gini coefficient or Coefficient of Variation. Relative global inequality has declined substantially over the decades. In contrast, ‘absolute’ inequality, as captured by the Standard Deviation and Absolute Gini, has increased considerably...... and unabated. Like these ‘absolute’ measures, our ‘centrist’ inequality indicators, the Krtscha measure and an intermediate Gini, also register a pronounced increase in global inequality, albeit, in the case of the latter, with a decline during 2005 to 2010. A critical question posed by our findings is whether...
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Declining global warming effects on the phenology of spring leaf unfolding.
Fu, Yongshuo H; Zhao, Hongfang; Piao, Shilong; Peaucelle, Marc; Peng, Shushi; Zhou, Guiyun; Ciais, Philippe; Huang, Mengtian; Menzel, Annette; Peñuelas, Josep; Song, Yang; Vitasse, Yann; Zeng, Zhenzhong; Janssens, Ivan A
2015-10-01
Earlier spring leaf unfolding is a frequently observed response of plants to climate warming. Many deciduous tree species require chilling for dormancy release, and warming-related reductions in chilling may counteract the advance of leaf unfolding in response to warming. Empirical evidence for this, however, is limited to saplings or twigs in climate-controlled chambers. Using long-term in situ observations of leaf unfolding for seven dominant European tree species at 1,245 sites, here we show that the apparent response of leaf unfolding to climate warming (ST, expressed in days advance of leaf unfolding per °C warming) has significantly decreased from 1980 to 2013 in all monitored tree species. Averaged across all species and sites, ST decreased by 40% from 4.0 ± 1.8 days °C(-1) during 1980-1994 to 2.3 ± 1.6 days °C(-1) during 1999-2013. The declining ST was also simulated by chilling-based phenology models, albeit with a weaker decline (24-30%) than observed in situ. The reduction in ST is likely to be partly attributable to reduced chilling. Nonetheless, other mechanisms may also have a role, such as 'photoperiod limitation' mechanisms that may become ultimately limiting when leaf unfolding dates occur too early in the season. Our results provide empirical evidence for a declining ST, but also suggest that the predicted strong winter warming in the future may further reduce ST and therefore result in a slowdown in the advance of tree spring phenology.
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HPLC-NMR revisited: Using time-slice HPLC-SPE-NMR with database assisted dereplication
DEFF Research Database (Denmark)
Johansen, Kenneth; Wubshet, Sileshi Gizachew; Nyberg, Nils
2013-01-01
Time based trapping of chromatographically separated compounds on to solid-phase extraction cartridges (SPE) and subsequent elution to NMR-tubes was done to emulate the function of HPLC–NMR for dereplication purposes. Sufficient mass sensitivity was obtained by the use of a state-of-the-art HPLC......–SPE–NMR-system with a cryogenically cooled probe head, designed for 1.7 mm NMR-tubes. The resulting 1H NMR spectra (600 MHz) were evaluated against a database of previously acquired and prepared spectra. The in-house developed matching algorithm, based on partitioning of the spectra and allowing for changes in the chemical shifts......, is described and the code included as Supplementary Information. Two mixtures of natural products was used to test the approach; one extract of Carthamus oxyacantha (wild safflower) containing an array of spiro compounds and one extract of the endophytic fungus Penicillum namyslowski containing griseofulvin...
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NMR for chemists and biologists
Carbajo, Rodrigo J
2013-01-01
This book offers a concise introduction to the field of nuclear magnetic resonance or NMR. It presents the basic foundations of NMR in a non-mathematical way and provides an overview of both recent and important biological applications of NMR.
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An NMR log echo data de-noising method based on the wavelet packet threshold algorithm
International Nuclear Information System (INIS)
Meng, Xiangning; Xie, Ranhong; Li, Changxi; Hu, Falong; Li, Chaoliu; Zhou, Cancan
2015-01-01
To improve the de-noising effects of low signal-to-noise ratio (SNR) nuclear magnetic resonance (NMR) log echo data, this paper applies the wavelet packet threshold algorithm to the data. The principle of the algorithm is elaborated in detail. By comparing the properties of a series of wavelet packet bases and the relevance between them and the NMR log echo train signal, ‘sym7’ is found to be the optimal wavelet packet basis of the wavelet packet threshold algorithm to de-noise the NMR log echo train signal. A new method is presented to determine the optimal wavelet packet decomposition scale; this is within the scope of its maximum, using the modulus maxima and the Shannon entropy minimum standards to determine the global and local optimal wavelet packet decomposition scales, respectively. The results of applying the method to the simulated and actual NMR log echo data indicate that compared with the wavelet threshold algorithm, the wavelet packet threshold algorithm, which shows higher decomposition accuracy and better de-noising effect, is much more suitable for de-noising low SNR–NMR log echo data. (paper)
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Energy Technology Data Exchange (ETDEWEB)
Bluemich, Bernhard; Haber-Pohlmeier, Sabina; Zia, Wasif [RWTH Aachen Univ. (Germany). Inst. fuer Technische und Makromolekulare Chemie (ITMC)
2014-06-01
Nuclear Magnetic Resonance (NMR) spectroscopy is the most popular method for chemists to analyze molecular structures, while Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic tool for medical doctors that provides high-contrast images of biological tissue. In both applications, the sample (or patient) is positioned inside a large, superconducting magnet to magnetize the atomic nuclei. Interrogating radio-frequency pulses result in frequency spectra that provide the chemist with molecular information, the medical doctor with anatomic images, and materials scientist with NMR relaxation parameters. Recent advances in magnet technology have led to a variety of small permanent magnets to allow compact and low-cost instruments. The goal of this book is to provide an introduction to the practical use of compact NMR at a level nearly as basic as the operation of a smart phone.
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Solid-state NMR of inorganic semiconductors.
Yesinowski, James P
2012-01-01
Studies of inorganic semiconductors by solid-state NMR vary widely in terms of the nature of the samples investigated, the techniques employed to observe the NMR signal, and the types of information obtained. Compared with the NMR of diamagnetic non-semiconducting substances, important differences often result from the presence of electron or hole carriers that are the hallmark of semiconductors, and whose theoretical interpretation can be involved. This review aims to provide a broad perspective on the topic for the non-expert by providing: (1) a basic introduction to semiconductor physical concepts relevant to NMR, including common crystal structures and the various methods of making samples; (2) discussions of the NMR spin Hamiltonian, details of some of the NMR techniques and strategies used to make measurements and theoretically predict NMR parameters, and examples of how each of the terms in the Hamiltonian has provided useful information in bulk semiconductors; (3) a discussion of the additional considerations needed to interpret the NMR of nanoscale semiconductors, with selected examples. The area of semiconductor NMR is being revitalized by this interest in nanoscale semiconductors, the great improvements in NMR detection sensitivity and resolution that have occurred, and the current interest in optical pumping and spintronics-related studies. Promising directions for future research will be noted throughout.
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Mechanisms of Age-Related Decline in Memory Search across the Adult Life Span
Hills, Thomas T.; Mata, Rui; Wilke, Andreas; Samanez-Larkin, Gregory R.
2013-01-01
Three alternative mechanisms for age-related decline in memory search have been proposed, which result from either reduced processing speed (global slowing hypothesis), overpersistence on categories (cluster-switching hypothesis), or the inability to maintain focus on local cues related to a decline in working memory (cue-maintenance hypothesis).…
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Relaxation time T/sub 1/ and bound water fraction of muscle by NMR imager
Energy Technology Data Exchange (ETDEWEB)
Fukuda, N.; Ikehira, H.; Yamane, T.; Tateno, Y.; Torii, S.; Matsumura, K.
1986-05-01
In order to establish the efficacy of NMR-CT in the diagnostic investigation of muscle disorders, proton NMR-CT imaging was performed and muscle longitudinal relaxation (T1) times were measured in 20 Duchenne muscular dystrophy (DMD) patients and normal controls (NC). In addition, the bound water fraction (BWF) was calculated from the measured T1 value in appropriate cases. Results show that in DMD muscle T1 values were above normal in the early clinical stages, declined rapidly with progress of the disease, and reached the same low level as the subcutaneous fat. This decrease of T1 values was not uniform for all muscles, being most prominent in gluteus maximus and least in sartorius and gracilis. In NC muscle BWF increased with maturation under the age of 10 years, and became fixed beyond that. In the early stages of DMD, BWF was below normal.
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Structural Biology: Practical NMR Applications
Teng, Quincy
2005-01-01
This textbook begins with an overview of NMR development and applications in biological systems. It describes recent developments in instrument hardware and methodology. Chapters highlight the scope and limitation of NMR methods. While detailed math and quantum mechanics dealing with NMR theory have been addressed in several well-known NMR volumes, chapter two of this volume illustrates the fundamental principles and concepts of NMR spectroscopy in a more descriptive manner. Topics such as instrument setup, data acquisition, and data processing using a variety of offline software are discussed. Chapters further discuss several routine stategies for preparing samples, especially for macromolecules and complexes. The target market for such a volume includes researchers in the field of biochemistry, chemistry, structural biology and biophysics.
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Cerebral amyloidosis associated with cognitive decline in autosomal dominant Alzheimer disease.
Wang, Fen; Gordon, Brian A; Ryman, Davis C; Ma, Shengmei; Xiong, Chengjie; Hassenstab, Jason; Goate, Alison; Fagan, Anne M; Cairns, Nigel J; Marcus, Daniel S; McDade, Eric; Ringman, John M; Graff-Radford, Neill R; Ghetti, Bernardino; Farlow, Martin R; Sperling, Reisa; Salloway, Steve; Schofield, Peter R; Masters, Colin L; Martins, Ralph N; Rossor, Martin N; Jucker, Mathias; Danek, Adrian; Förster, Stefan; Lane, Christopher A S; Morris, John C; Benzinger, Tammie L S; Bateman, Randall J
2015-09-01
To investigate the associations of cerebral amyloidosis with concurrent cognitive performance and with longitudinal cognitive decline in asymptomatic and symptomatic stages of autosomal dominant Alzheimer disease (ADAD). Two hundred sixty-three participants enrolled in the Dominantly Inherited Alzheimer Network observational study underwent neuropsychological evaluation as well as PET scans with Pittsburgh compound B. One hundred twenty-one participants completed at least 1 follow-up neuropsychological evaluation. Four composite cognitive measures representing global cognition, episodic memory, language, and working memory were generated using z scores from a battery of 13 standard neuropsychological tests. General linear mixed-effects models were used to investigate the relationship between baseline cerebral amyloidosis and baseline cognitive performance and whether baseline cerebral amyloidosis predicts cognitive change over time (mean follow-up 2.32 years ± 0.92, range 0.89-4.19) after controlling for estimated years from expected symptom onset, APOE ε4 allelic status, and education. In asymptomatic mutation carriers, amyloid burden was not associated with baseline cognitive functioning but was significantly predictive of longitudinal decline in episodic memory. In symptomatic mutation carriers, cerebral amyloidosis was correlated with worse baseline performance in multiple cognitive composites and predicted greater decline over time in global cognition, working memory, and Mini-Mental State Examination. Cerebral amyloidosis predicts longitudinal episodic memory decline in presymptomatic ADAD and multidomain cognitive decline in symptomatic ADAD. These findings imply that amyloidosis in the brain is an indicator of early cognitive decline and provides a useful outcome measure for early assessment and prevention treatment trials. © 2015 American Academy of Neurology.
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Targeting global conservation funding to limit immediate biodiversity declines.
Waldron, Anthony; Mooers, Arne O; Miller, Daniel C; Nibbelink, Nate; Redding, David; Kuhn, Tyler S; Roberts, J Timmons; Gittleman, John L
2013-07-16
Inadequate funding levels are a major impediment to effective global biodiversity conservation and are likely associated with recent failures to meet United Nations biodiversity targets. Some countries are more severely underfunded than others and therefore represent urgent financial priorities. However, attempts to identify these highly underfunded countries have been hampered for decades by poor and incomplete data on actual spending, coupled with uncertainty and lack of consensus over the relative size of spending gaps. Here, we assemble a global database of annual conservation spending. We then develop a statistical model that explains 86% of variation in conservation expenditures, and use this to identify countries where funding is robustly below expected levels. The 40 most severely underfunded countries contain 32% of all threatened mammalian diversity and include neighbors in some of the world's most biodiversity-rich areas (Sundaland, Wallacea, and Near Oceania). However, very modest increases in international assistance would achieve a large improvement in the relative adequacy of global conservation finance. Our results could therefore be quickly applied to limit immediate biodiversity losses at relatively little cost.
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Systematic comparison of crystal and NMR protein structures deposited in the protein data bank.
Sikic, Kresimir; Tomic, Sanja; Carugo, Oliviero
2010-09-03
Nearly all the macromolecular three-dimensional structures deposited in Protein Data Bank were determined by either crystallographic (X-ray) or Nuclear Magnetic Resonance (NMR) spectroscopic methods. This paper reports a systematic comparison of the crystallographic and NMR results deposited in the files of the Protein Data Bank, in order to find out to which extent these information can be aggregated in bioinformatics. A non-redundant data set containing 109 NMR - X-ray structure pairs of nearly identical proteins was derived from the Protein Data Bank. A series of comparisons were performed by focusing the attention towards both global features and local details. It was observed that: (1) the RMDS values between NMR and crystal structures range from about 1.5 Å to about 2.5 Å; (2) the correlation between conformational deviations and residue type reveals that hydrophobic amino acids are more similar in crystal and NMR structures than hydrophilic amino acids; (3) the correlation between solvent accessibility of the residues and their conformational variability in solid state and in solution is relatively modest (correlation coefficient = 0.462); (4) beta strands on average match better between NMR and crystal structures than helices and loops; (5) conformational differences between loops are independent of crystal packing interactions in the solid state; (6) very seldom, side chains buried in the protein interior are observed to adopt different orientations in the solid state and in solution.
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Ligand-receptor Interactions by NMR Spectroscopy
Directory of Open Access Journals (Sweden)
Novak. P.
2008-04-01
Full Text Available Today NMR spectroscopy is a method of choice for elucidation of interactions between biomolecules and the potential ligands. Knowledge on these interactions is an essential prerequisite for the rational drug design. The most important contribution of NMR to drug design a few years ago was the 3D structure determination of proteins. Besides delivering the 3D structures of the free proteins as a raw material for the modeling studies on ligand binding, NMR can directly yield valuable experimental data on the biologically important protein-ligand complexes. In addition to X-ray diffraction, NMR spectroscopy can provide information on the internal protein dynamics ordynamics of intermolecular interactions. Changes in NMR parameters allow us to detect ("SAR by NMR" and quantitatively determine binding affinities (titration, diffusion NMR experiments, etc. of potential ligands. Also, it is possible to determine the binding site and conformations of ligands, receptors and receptor-ligand complexes with the help of NMR methods such as tr-NOESY. Epitopes or functional groups responsible for binding of ligands to the receptor can be identified by employing STD or WaterLOGSY experiments. In this review are described some of the most frequent NMR methods for the characterization of the interactions between biomolecules and ligands, together with their advantages and disadvantages.
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Two dimensional solid state NMR
International Nuclear Information System (INIS)
Kentgens, A.P.M.
1987-01-01
This thesis illustrates, by discussing some existing and newly developed 2D solid state experiments, that two-dimensional NMR of solids is a useful and important extension of NMR techniques. Chapter 1 gives an overview of spin interactions and averaging techniques important in solid state NMR. As 2D NMR is already an established technique in solutions, only the basics of two dimensional NMR are presented in chapter 2, with an emphasis on the aspects important for solid spectra. The following chapters discuss the theoretical background and applications of specific 2D solid state experiments. An application of 2D-J resolved NMR, analogous to J-resolved spectroscopy in solutions, to natural rubber is given in chapter 3. In chapter 4 the anisotropic chemical shift is mapped out against the heteronuclear dipolar interaction to obtain information about the orientation of the shielding tensor in poly-(oxymethylene). Chapter 5 concentrates on the study of super-slow molecular motions in polymers using a variant of the 2D exchange experiment developed by us. Finally chapter 6 discusses a new experiment, 2D nutation NMR, which makes it possible to study the quadrupole interaction of half-integer spins. 230 refs.; 48 figs.; 8 tabs
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Trouble in the aquatic world: How wildlife professionals are battling amphibian declines
Olson, Deanna H.; Chestnut, Tara E.
2014-01-01
A parasitic fungus, similar to the one that caused the extinction of numerous tropical frog and toad species, is killing salamanders in Europe. Scientists first identified the fungus, Batrachochytrium salamandrivorans, in 2013 as the culprit behind the death of fire salamanders (Salamandra salamandra) in the Netherlands (Martel et al. 2013) and are now exploring its potential impact to other species. Although the fungus, which kills the amphibians by infecting their skin, has not yet spread to the United States, researchers believe it’s only a matter of time before it does and, when that happens, the impact on salamander populations could be devastating (Martel et al. 2014).Reports of worldwide declines of amphibians began a quarter of a century ago (Blaustein & Wake 1990). Globally, some amphibian population declines occurred in the late 1950s and early 1960s, and declining trends continued in North America (Houlahan et al. 2000). In the earlier years, population declines were attributed primarily to overharvest due to unregulated supply of species such as the northern leopard frog (Lithobates pipiens) for educational use (Dodd 2013). In later years, however, causes of declines were less evident. In 1989, herpetologists at the First World Congress of Herpetology traded alarming stories of losses across continents and in seemingly protected landscapes, making it clear that amphibian population declines were a “global phenomenon.” In response to these reports, in 1991, the International Union for Conservation of Nature (IUCN) established the Declining Amphibian Populations Task Force to better understand the scale and scope of global amphibian declines. Unfortunately, the absence of long-term monitoring data and targeted studies made it difficult for the task force to compile information.Today, according to AmphibiaWeb.org, there are 7,342 amphibian species in the world — double the number since the first alerts of declines — making the situation
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Advanced NMR technology for bioscience and biotechnology
Energy Technology Data Exchange (ETDEWEB)
Hammel, P.C.; Hernandez, G.; Trewhella, J.; Unkefer, C.J. [Los Alamos National Lab., NM (US); Boumenthal, D.K. [Univ. of Utah, Salt Lake City, UT (US); Kennedy, M.A. [Pacific Northwest National Lab., Richland, WA (US); Moore, G.J. [Wayne State Univ., Detroit, MI (US)
1998-11-01
This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). NMR plays critical roles in bioscience and biotechnology in both imaging and structure determination. NMR is limited, however, by the inherent low sensitivity of the NMR experiment and the demands for spectral resolution required to study biomolecules. The authors addressed both of these issues by working on the development of NMR force microscopy for molecular imaging, and high field NMR with isotope labeling to overcome limitations in the size of biomolecules that can be studied using NMR. A novel rf coil design for NMR force microscopy was developed that increases the limits of sensitivity in magnetic resonance detection for imaging, and the authors demonstrated sub-surface spatial imaging capabilities. The authors also made advances in the miniaturization of two critical NMR force microscope components. They completed high field NMR and isotope labeling studies of a muscle protein complex which is responsible for regulating muscle contraction and is too large for study using conventional NMR approaches.
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International Nuclear Information System (INIS)
McCready, V.R.; Leach, M.O.; Sutton; Ell, P.
1986-01-01
The object of this book is to discuss and evaluate an area of Nuclear Magnetic Resonance which to date has been less emphasized than it might be, namely the use of NMR for functional studies. The book commences with a discussion of the areas in which the NMR techniques might be needed due to deficiencies in other techniques. The physics of NMR especially relating to functional measurement are then explained. Technical factors in producing functional images are discussed and the use of paramagnetic substances for carrying out flow studies are detailed. Particular attention is paid to specific studies in the various organs. The book ends with a survey of imaging in each organ and the relation of NMR images to other techniques such as ultrasound, nuclear medicine and X-rays
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31P NMR characterization of graded traumatic brain injury in rats
International Nuclear Information System (INIS)
Vink, R.; McIntosh, T.K.; Yamakami, I.; Faden, A.I.
1988-01-01
Irreversible tissue injury following central nervous system trauma is believed to result from both mechanical disruption at the time of primary insult, and more delayed autodestructive processes. These delayed events are associated with various biochemical changes, including alterations in phosphate energy metabolism and intracellular pH. Using 31 P NMR, we have monitored the changes in phosphorus energy metabolism and intracellular pH in a single hemisphere of the rat brain over an 8-h period following graded, traumatic, fluid percussion-induced brain injury. Following trauma the ratio of phosphocreatine to inorganic phosphate (PCr/Pi) declined in each injury group. This decline was transitory with low injury (1.0 +/- 0.5 atm), biphasic with moderate (2.1 +/- 0.4 atm) and high (3.9 +/- 0.9 atm) injury, and sustained following severe injury (5.9 +/- 0.7 atm). The initial PCr/Pi decline in the moderate and high injury groups was associated with intracellular acidosis; however, the second decline occurred in the absence of any pH changes. Alterations in ATP occurred only in severely injured animals and such changes were associated with marked acidosis and 100% mortality rate. After 4h, the posttraumatic PCr/Pi ratio correlated linearly with the severity of injury. We suggest that a reduced posttraumatic PCr/Pi ratio may be indicative of altered mitochondrial energy production and may predict a reduced capacity of the cell to recover from traumatic injury
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Recent Advances in Targeted and Untargeted Metabolomics by NMR and MS/NMR Methods
Energy Technology Data Exchange (ETDEWEB)
Bingol, Kerem
2018-04-18
Metabolomics has made significant progress in multiple fronts in the last 18 months. This minireview aimed to give an overview of these advancements in the light of their contribution to targeted and untargeted metabolomics. New computational approaches have emerged to overcome manual absolute quantitation step of metabolites in 1D 1H NMR spectra. This provides more consistency between inter-laboratory comparisons. Integration of 2D NMR metabolomics databases under a unified web server allowed very accurate identification of the metabolites that have been catalogued in these databases. For the remaining uncatalogued and unknown metabolites, new cheminformatics approaches have been developed by combining NMR and mass spectrometry. These hybrid NMR/MS approaches accelerated the identification of unknowns in untargeted studies, and now they are allowing to profile ever larger number of metabolites in application studies.
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Magic Angle Spinning NMR Metabolomics
Energy Technology Data Exchange (ETDEWEB)
Zhi Hu, Jian
2016-01-01
Nuclear Magnetic Resonance (NMR) spectroscopy is a non-destructive, quantitative, reproducible, untargeted and unbiased method that requires no or minimal sample preparation, and is one of the leading analytical tools for metabonomics research [1-3]. The easy quantification and the no need of prior knowledge about compounds present in a sample associated with NMR are advantageous over other techniques [1,4]. 1H NMR is especially attractive because protons are present in virtually all metabolites and its NMR sensitivity is high, enabling the simultaneous identification and monitoring of a wide range of low molecular weight metabolites.
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DEFF Research Database (Denmark)
Sundekilde, Ulrik; Larsen, Lotte Bach; Bertram, Hanne Christine S.
2013-01-01
and processing capabilities of bovine milk is closely associated to milk composition. Metabolomics is ideal in the study of the low-molecular-weight compounds in milk, and this review focuses on the recent nuclear magnetic resonance (NMR)-based metabolomics trends in milk research, including applications linking...... compounds. Furthermore, metabolomics applications elucidating how the differential regulated genes affects milk composition are also reported. This review will highlight the recent advances in NMR-based metabolomics on milk, as well as give a brief summary of when NMR spectroscopy can be useful for gaining...
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Risks of rapid decline renal function in patients with type 2 diabetes
Institute of Scientific and Technical Information of China (English)
Yi-Jing; Sheen; Wayne; HH; Sheu
2014-01-01
Progressive rising population of diabetes and related nephropathy, namely, diabetic kidney disease and associated end stage renal disease has become a major global public health issue. Results of observational studies indicate that most diabetic kidney disease progresses over decades; however, certain diabetes patients display a rapid decline in renal function, which may lead to renal failure within months. Although the definition of rapid renal function decline remained speculative, in general,it is defined by the decrease of estimated glomerular filtration rate(e GFR) in absolute rate of loss or percent change. Based on the Kidney Disease: Improving Global Outcomes 2012 clinical practice guidelines, a rapid decline in renal function is defined as a sustained declinein e GFR of > 5 m L/min per 1.73 m2 per year. It has been reported that potential factors contributing to a rapid decline in renal function include ethnic/genetic and demographic causes, smoking habits, increased glycated hemoglobin levels, obesity, albuminuria, anemia, low serum magnesium levels, high serum phosphate levels, vitamin D deficiency, elevated systolic blood pressure, pulse pressure, brachial-ankle pulse wave velocity values, retinopathy, and cardiac autonomic neuropathy. This article reviews current literatures in this area and provides insight on the early detection of diabetic subjects who are at risk of a rapid decline in renal function in order to develop a more aggressive approach to renal and cardiovascular protection.
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Late life leisure activities and risk of cognitive decline.
Wang, Hui-Xin; Jin, Yinlong; Hendrie, Hugh C; Liang, Chaoke; Yang, Lili; Cheng, Yibin; Unverzagt, Frederick W; Ma, Feng; Hall, Kathleen S; Murrell, Jill R; Li, Ping; Bian, Jianchao; Pei, Jin-Jing; Gao, Sujuan
2013-02-01
Studies concerning the effect of different types of leisure activities on various cognitive domains are limited. This study tests the hypothesis that mental, physical, and social activities have a domain-specific protection against cognitive decline. A cohort of a geographically defined population in China was examined in 2003-2005 and followed for an average of 2.4 years. Leisure activities were assessed in 1,463 adults aged 65 years and older without cognitive or physical impairment at baseline, and their cognitive performances were tested at baseline and follow-up examinations. High level of mental activity was related to less decline in global cognition (β = -.23, p Leisure activities in old age may protect against cognitive decline for both women and men, and different types of activities seem to benefit different cognitive domains.
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NMR imaging of cerebral infarction
International Nuclear Information System (INIS)
Takusagawa, Yoshihiko; Yamaoka, Naoki; Doi, Kazuaki; Okada, Keisei
1987-01-01
One hundred and five patients with cerebral infarction were studied by nuclear magnetic resonance (NMR) CT (resistive type of magnet with strength of 0.1 tesla) and X-ray CT. Pulse sequences used saturation recovery (Tr = 600 mSec), Inversion recovery (Tr = 500 mSec, Td = 300 mSec) and spin echo (Tr = 1500 mSec, Te = 40, 80, 120, 160 mSec). Fifteen cases were examined by NMR-CT within 24 hours from onset. Proton NMR imaging could not detect cerebral ischemia as early as 2 hours after onset, but except could detect the lesions in Se image the area of cerebral infarct 3 hours after onset. After 5 hours from onset image changes in SE were evident and corresponded to the area of cerebral infarct, but image changes in IR could not fully delineate the infarcted area. NMR images of 41 year-old woman with cerebral embolism by MCA trunck occlusion associated with mitral stenosis were presented, and NMR-CT was examined 10 hours, 9th and 43th days after episode of MCA occlusion. Sixty patents (64 times) with lacunar infarction were studied by NMR-CT and X-ray CT. The inversion recovery images were used mainly for detection of lesions and comparison with X-ray CT. In 160 lesions which were detected by NMR-CT or X-ray CT, could 156 lesions be detected by NMR-CT and 78 lesions by X-ray CT. Inversion recovery images were more useful for detection of lacunes than X-ray CT. Calculated T1 and T2 values prolonged with time course from onset. (author)
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Zakoucka, Eva
2013-01-01
During my summer student programme I was working on sample optimization for a new β-NMR project at the ISOLDE facility. The β-NMR technique is well-established in solid-state physics and just recently it is being introduced for applications in biochemistry and life sciences. The β-NMR collaboration will be applying for beam time to the INTC committee in September for three nuclei: Cu, Zn and Mg. Sample optimization for Mg was already performed last year during the summer student programme. Therefore sample optimization for Cu and Zn had to be completed as well for the project proposal. My part in the project was to perform thorough literature research on techniques studying Cu and Zn complexes in native conditions, search for relevant binding candidates for Cu and Zn applicable for ß-NMR and eventually evaluate selected binding candidates using UV-VIS spectrometry.
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Redetzke, Rebecca A.; Gerdes, A. Martin
2012-01-01
Thyroid hormones (THs) play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV) contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH). LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function. PMID:23056390
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Directory of Open Access Journals (Sweden)
Nathan Y Weltman
Full Text Available Thyroid hormones (THs play a pivotal role in cardiac homeostasis. TH imbalances alter cardiac performance and ultimately cause cardiac dysfunction. Although short-term hyperthyroidism typically leads to heightened left ventricular (LV contractility and improved hemodynamic parameters, chronic hyperthyroidism is associated with deleterious cardiac consequences including increased risk of arrhythmia, impaired cardiac reserve and exercise capacity, myocardial remodeling, and occasionally heart failure. To evaluate the long-term consequences of chronic hyperthyroidism on LV remodeling and function, we examined LV isolated myocyte function, chamber function, and whole tissue remodeling in a hamster model. Three-month-old F1b hamsters were randomized to control or 10 months TH treatment (0.1% grade I desiccated TH. LV chamber remodeling and function was assessed by echocardiography at 1, 2, 4, 6, 8, and 10 months of treatment. After 10 months, terminal cardiac function was assessed by echocardiography and LV hemodynamics. Hyperthyroid hamsters exhibited significant cardiac hypertrophy and deleterious cardiac remodeling characterized by myocyte lengthening, chamber dilatation, decreased relative wall thickness, increased wall stress, and increased LV interstitial fibrotic deposition. Importantly, hyperthyroid hamsters demonstrated significant LV systolic and diastolic dysfunction. Despite the aforementioned remodeling and global cardiac decline, individual isolated cardiac myocytes from chronically hyperthyroid hamsters had enhanced function when compared with myocytes from untreated age-matched controls. Thus, it appears that long-term hyperthyroidism may impair global LV function, at least in part by increasing interstitial ventricular fibrosis, in spite of normal or enhanced intrinsic cardiomyocyte function.
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Microprocessorized NMR measurement
International Nuclear Information System (INIS)
Rijllart, A.
1984-01-01
An MC68000 CAMAC microprocessor system for fast and accurate NMR signal measurement will be presented. A stand-alone CAMAC microprocessor system (MC68000 STAC) with a special purpose interface sweeps a digital frequency synthesizer and digitizes the NMR signal with a 16-bit ADC of 17 μs conversion time. It averages the NMR signal data over many sweeps and then transfers it through CAMAC to a computer for calculation of the signal parameters. The computer has full software control over the timing and sweep settings of this signal averager, and thus allows optimization of noise suppression. Several of these processor systems can be installed in the same crate for parallel processing, and the flexibility of the STAC also allows easy adaptation to other applications such as transient recording or phase-sensitive detection. (orig.)
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Kamal, Ghulam Mustafa; Wang, Xiaohua; Bin Yuan; Wang, Jie; Sun, Peng; Zhang, Xu; Liu, Maili
2016-09-01
Soy sauce a well known seasoning all over the world, especially in Asia, is available in global market in a wide range of types based on its purpose and the processing methods. Its composition varies with respect to the fermentation processes and addition of additives, preservatives and flavor enhancers. A comprehensive (1)H NMR based study regarding the metabonomic variations of soy sauce to differentiate among different types of soy sauce available on the global market has been limited due to the complexity of the mixture. In present study, (13)C NMR spectroscopy coupled with multivariate statistical data analysis like principle component analysis (PCA), and orthogonal partial least square-discriminant analysis (OPLS-DA) was applied to investigate metabonomic variations among different types of soy sauce, namely super light, super dark, red cooking and mushroom soy sauce. The main additives in soy sauce like glutamate, sucrose and glucose were easily distinguished and quantified using (13)C NMR spectroscopy which were otherwise difficult to be assigned and quantified due to serious signal overlaps in (1)H NMR spectra. The significantly higher concentration of sucrose in dark, red cooking and mushroom flavored soy sauce can directly be linked to the addition of caramel in soy sauce. Similarly, significantly higher level of glutamate in super light as compared to super dark and mushroom flavored soy sauce may come from the addition of monosodium glutamate. The study highlights the potentiality of (13)C NMR based metabonomics coupled with multivariate statistical data analysis in differentiating between the types of soy sauce on the basis of level of additives, raw materials and fermentation procedures. Copyright © 2016 Elsevier B.V. All rights reserved.
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War in the Era of Declining U.S. Global Hegemony
Directory of Open Access Journals (Sweden)
Francis Shor
2010-01-01
Full Text Available While Clausewitz’s perspective that ‘war is the continuation of politics by other means’ is widely quoted, the full implications of that perspective are rarely explored. What I propose to highlight in this essay is how the imperial political projects of the UnitedStates in the post-Vietnam era unleashed direct and indirect regional war strategies from Latin America to the Middle East. The essay will highlight, in particular, the wide variety of such strategies from covert intervention in Chile to proxy wars in Central America to military intervention in Iraq and Afghanistan. Attempting to re-assert its global hegemony after Vietnam, the U.S. became more committed to perpetrating war as an instrument of its global posture. Of course, relying on war strategies, whether through direct or indirect interventions, complicates, if not confounds, the imposition of global hegemony.
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Fourier transform n.m.r. spectroscopy
International Nuclear Information System (INIS)
Shaw, D.
1976-01-01
This book is orientated to techniques rather than applications. The basic theory of n.m.r. is dealt with in a unified approach to the Fourier theory. The middle section of the book concentrates on the practical aspects of Fourier n.m.r., both instrumental and experimental. The final chapters briefly cover general application of n.m.r., but concentrate strongly on those areas where Fourier n.m.r. can give information which is not available by conventional techniques
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International Nuclear Information System (INIS)
Marassi, Francesca M.; Ding, Yi; Schwieters, Charles D.; Tian, Ye; Yao, Yong
2015-01-01
The outer membrane protein Ail (attachment invasion locus) is a virulence factor of Yersinia pestis that mediates cell invasion, cell attachment and complement resistance. Here we describe its three-dimensional backbone structure determined in decyl-phosphocholine (DePC) micelles by NMR spectroscopy. The NMR structure was calculated using the membrane function of the implicit solvation potential, eefxPot, which we have developed to facilitate NMR structure calculations in a physically realistic environment. We show that the eefxPot force field guides the protein towards its native fold. The resulting structures provide information about the membrane-embedded global position of Ail, and have higher accuracy, higher precision and improved conformational properties, compared to the structures calculated with the standard repulsive potential
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Fundamentals of Protein NMR Spectroscopy
Rule, Gordon S
2006-01-01
NMR spectroscopy has proven to be a powerful technique to study the structure and dynamics of biological macromolecules. Fundamentals of Protein NMR Spectroscopy is a comprehensive textbook that guides the reader from a basic understanding of the phenomenological properties of magnetic resonance to the application and interpretation of modern multi-dimensional NMR experiments on 15N/13C-labeled proteins. Beginning with elementary quantum mechanics, a set of practical rules is presented and used to describe many commonly employed multi-dimensional, multi-nuclear NMR pulse sequences. A modular analysis of NMR pulse sequence building blocks also provides a basis for understanding and developing novel pulse programs. This text not only covers topics from chemical shift assignment to protein structure refinement, as well as the analysis of protein dynamics and chemical kinetics, but also provides a practical guide to many aspects of modern spectrometer hardware, sample preparation, experimental set-up, and data pr...
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An introduction to biological NMR spectroscopy
International Nuclear Information System (INIS)
Marion, Dominique
2013-01-01
NMR spectroscopy is a powerful tool for biologists interested in the structure, dynamics, and interactions of biological macromolecules. This review aims at presenting in an accessible manner the requirements and limitations of this technique. As an introduction, the history of NMR will highlight how the method evolved from physics to chemistry and finally to biology over several decades. We then introduce the NMR spectral parameters used in structural biology, namely the chemical shift, the J-coupling, nuclear Overhauser effects, and residual dipolar couplings. Resonance assignment, the required step for any further NMR study, bears a resemblance to jigsaw puzzle strategy. The NMR spectral parameters are then converted into angle and distances and used as input using restrained molecular dynamics to compute a bundle of structures. When interpreting a NMR-derived structure, the biologist has to judge its quality on the basis of the statistics provided. When the 3D structure is a priori known by other means, the molecular interaction with a partner can be mapped by NMR: information on the binding interface as well as on kinetic and thermodynamic constants can be gathered. NMR is suitable to monitor, over a wide range of frequencies, protein fluctuations that play a crucial role in their biological function. In the last section of this review, intrinsically disordered proteins, which have escaped the attention of classical structural biology, are discussed in the perspective of NMR, one of the rare available techniques able to describe structural ensembles. This Tutorial is part of the International Proteomics Tutorial Programme (IPTP 16 MCP). (authors)
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International Nuclear Information System (INIS)
Raftery, M.D.
1991-11-01
Nuclear Magnetic Resonance (NMR) spectroscopy of xenon has become an important tool for investigating a wide variety of materials, especially those with high surface area. The sensitivity of its chemical shift to environment, and its chemical inertness and adsorption properties make xenon a particularly useful NMR probe. This work discusses the application of optical pumping to enhance the sensitivity of xenon NMR experiments, thereby allowing them to be used in the study of systems with lower surface area. A novel method of optically-pumping 129 Xe in low magnetic field below an NMR spectrometer and subsequent transfer of the gas to high magnetic field is described. NMR studies of the highly polarized gas adsorbed onto powdered samples with low to moderate surface areas are now possible. For instance, NMR studies of optically-pumped xenon adsorbed onto polyacrylic acid show that xenon has a large interaction with the surface. By modeling the low temperature data in terms of a sticking probability and the gas phase xenon-xenon interaction, the diffusion coefficient for xenon at the surface of the polymer is determined. The sensitivity enhancement afforded by optical pumping also allows the NMR observation of xenon thin films frozen onto the inner surfaces of different sample cells. The geometry of the thin films results in interesting line shapes that are due to the bulk magnetic susceptibility of xenon. Experiments are also described that combine optical pumping with optical detection for high sensitivity in low magnetic field to observe the quadrupoler evolution of 131 Xe spins at the surface of the pumping cells. In cells with macroscopic asymmetry, a residual quadrupolar interaction causes a splitting in the 131 Xe NMR frequencies in bare Pyrex glass cells and cells with added hydrogen
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International Nuclear Information System (INIS)
McCready, V.R.; Leach, M.; Ell, P.J.
1987-01-01
This volume is based on a series of lectures delivered at a one-day teaching symposium on functional and metabolic aspects of NMR measurements held at the Middlesex Hospital Medical School on 1st September 1985 as a part of the European Nuclear Medicine Society Congress. Currently the major emphasis in medical NMR in vivo is on its potential to image and display abnormalities in conventional radiological images, providing increased contrast between normal and abnormal tissue, improved definition of vasculature, and possibly an increased potential for differential diagnosis. Although these areas are undeniably of major importance, it is probable that NMR will continue to complement conventional measurement methods. The major potential benefits to be derived from in vivo NMR measurements are likely to arise from its use as an instrument for functional and metabolic studies in both clinical research and in the everyday management of patients. It is to this area that this volume is directed
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Quantitative evidence for the effects of multiple drivers on continental-scale amphibian declines
Grant, Evan H. Campbell; Miller, David A. W.; Schmidt, Benedikt R.; Adams, Michael J.; Amburgey, Staci M.; Chambert, Thierry A.; Cruickshank, Sam S.; Fisher, Robert N.; Green, David M.; Hossack, Blake R.; Johnson, Pieter T.J.; Joseph, Maxwell B.; Rittenhouse, Tracy A. G.; Ryan, Maureen E.; Waddle, J. Hardin; Walls, Susan C.; Bailey, Larissa L.; Fellers, Gary M.; Gorman, Thomas A.; Ray, Andrew M.; Pilliod, David S.; Price, Steven J.; Saenz, Daniel; Sadinski, Walt; Muths, Erin L.
2016-01-01
Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a “smoking gun” was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have identified factors leading to increased local extinction risk, evidence for effects of these drivers is lacking at large spatial scales. Here, we use observations of 389 time-series of 83 species and complexes from 61 study areas across North America to test the effects of 4 of the major hypothesized drivers of declines. While we find that local amphibian populations are being lost from metapopulations at an average rate of 3.79% per year, these declines are not related to any particular threat at the continental scale; likewise the effect of each stressor is variable at regional scales. This result - that exposure to threats varies spatially, and populations vary in their response - provides little generality in the development of conservation strategies. Greater emphasis on local solutions to this globally shared phenomenon is needed.
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NMR in structure-based drug design.
Carneiro, Marta G; Ab, Eiso; Theisgen, Stephan; Siegal, Gregg
2017-11-08
NMR spectroscopy is a powerful technique that can provide valuable structural information for drug discovery endeavors. Here, we discuss the strengths (and limitations) of NMR applications to structure-based drug discovery, highlighting the different levels of resolution and throughput obtainable. Additionally, the emerging field of paramagnetic NMR in drug discovery and recent developments in approaches to speed up and automate protein-observed NMR data collection and analysis are discussed. © 2017 The Author(s). Published by Portland Press Limited on behalf of the Biochemical Society.
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Agrochemicals increase trematode infections in a declining amphibian species.
Rohr, Jason R; Schotthoefer, Anna M; Raffel, Thomas R; Carrick, Hunter J; Halstead, Neal; Hoverman, Jason T; Johnson, Catherine M; Johnson, Lucinda B; Lieske, Camilla; Piwoni, Marvin D; Schoff, Patrick K; Beasley, Val R
2008-10-30
Global amphibian declines have often been attributed to disease, but ignorance of the relative importance and mode of action of potential drivers of infection has made it difficult to develop effective remediation. In a field study, here we show that the widely used herbicide, atrazine, was the best predictor (out of more than 240 plausible candidates) of the abundance of larval trematodes (parasitic flatworms) in the declining northern leopard frog Rana pipiens. The effects of atrazine were consistent across trematode taxa. The combination of atrazine and phosphate--principal agrochemicals in global corn and sorghum production--accounted for 74% of the variation in the abundance of these often debilitating larval trematodes (atrazine alone accounted for 51%). Analysis of field data supported a causal mechanism whereby both agrochemicals increase exposure and susceptibility to larval trematodes by augmenting snail intermediate hosts and suppressing amphibian immunity. A mesocosm experiment demonstrated that, relative to control tanks, atrazine tanks had immunosuppressed tadpoles, had significantly more attached algae and snails, and had tadpoles with elevated trematode loads, further supporting a causal relationship between atrazine and elevated trematode infections in amphibians. These results raise concerns about the role of atrazine and phosphate in amphibian declines, and illustrate the value of quantifying the relative importance of several possible drivers of disease risk while determining the mechanisms by which they facilitate disease emergence.
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International Nuclear Information System (INIS)
Pines, A.
1986-09-01
These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 55 figs
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Directory of Open Access Journals (Sweden)
Arthur S. Aldersen
2015-08-01
Full Text Available Recent years have witnessed a fairly dramatic upswing in the level of foreign direct investment, a phenomenon which has played an integral part in a larger process of globalization. While sociologists have devoted a good deal of attention to the consequences of direct investment for the developing hosts of foreign direct investment, much less attention has been paid to the implications of direct investment for the advanced industrial societies. ln this paper, I focus on one of the more interesting links that has been drawn between direct investment and its effects: that between the outflowof direct investment - often cast as "capital flight" - and deindustrialization. To examine this link I employ a pooled time-series of cross-sections dataset which combines observations on 17 OECD nations across the 1967-1990 period (N=408 . Random effects regression models, which control for unmeasured country-specific effects, reveal strong support for arguments which link direct investment to the relative decline of the labor force in manufacturing in core societies. ln addition, results show that deindustriali zation across this period is largely explained by a model that combines classic generalizations of the process of economic development with an attention to a range of more immediate factors identified by contemporary students of deindustrialization.
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Quantitative evidence for the effects of multiple drivers on continental-scale amphibian declines
Evan H. Campbell Grant; David A. W. Miller; Benedikt R. Schmidt; Michael J. Adams; Staci M. Amburgey; Thierry Chambert; Sam S. Cruickshank; Robert N. Fisher; David M. Green; Blake R. Hossack; Pieter T. J. Johnson; Maxwell B. Joseph; Tracy A. G. Rittenhouse; Maureen E. Ryan; J. Hardin Waddle; Susan C. Walls; Larissa L. Bailey; Gary M. Fellers; Thomas A. Gorman; Andrew M. Ray; David S. Pilliod; Steven J. Price; Daniel Saenz; Walt Sadinski; Erin Muths
2016-01-01
Since amphibian declines were first proposed as a global phenomenon over a quarter century ago, the conservation community has made little progress in halting or reversing these trends. The early search for a âsmoking gunâ was replaced with the expectation that declines are caused by multiple drivers. While field observations and experiments have identified factors...
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NMR spectroscopy using liquid crystal solvents
Emsley, JW
2013-01-01
NMR Spectroscopy using Liquid Crystal Solvents covers the importance of using a liquid crystal solvent in NMR to derive nuclear dipolar spin-spin coupling constants. This book is composed of ten chapters, and begins with a brief description of the features and benefits of liquid crystal in NMR spectroscopic analysis. The succeeding chapters deal with the mode of operation of nuclear spin Hamiltonian for partially oriented molecules and the analysis of NMR spectra of partially oriented molecules, as well as the determination of rigid molecule structure. These topics are followed by discussions
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NMR studies of isotopically labeled RNA
Energy Technology Data Exchange (ETDEWEB)
Pardi, A. [Univ. of Colorado, Boulder, CO (United States)
1994-12-01
In summary, the ability to generate NMR quantities of {sup 15}N and {sup 13}C-labeled RNAs has led to the development of heteronuclear multi-dimensional NMR techniques for simplifying the resonance assignment and structure determination of RNAs. These methods for synthesizing isotopically labeled RNAs are only several years old, and thus there are still relatively few applications of heteronuclear multi-dimensional NMR techniques to RNA. However, given the critical role that RNAs play in cellular function, one can expect to see an increasing number of NMR structural studies of biologically active RNAs.
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1H-NMR, 1H-NMR T2-edited, and 2D-NMR in bipolar disorder metabolic profiling.
Sethi, Sumit; Pedrini, Mariana; Rizzo, Lucas B; Zeni-Graiff, Maiara; Mas, Caroline Dal; Cassinelli, Ana Cláudia; Noto, Mariane N; Asevedo, Elson; Cordeiro, Quirino; Pontes, João G M; Brasil, Antonio J M; Lacerda, Acioly; Hayashi, Mirian A F; Poppi, Ronei; Tasic, Ljubica; Brietzke, Elisa
2017-12-01
The objective of this study was to identify molecular alterations in the human blood serum related to bipolar disorder, using nuclear magnetic resonance (NMR) spectroscopy and chemometrics. Metabolomic profiling, employing 1 H-NMR, 1 H-NMR T 2 -edited, and 2D-NMR spectroscopy and chemometrics of human blood serum samples from patients with bipolar disorder (n = 26) compared with healthy volunteers (n = 50) was performed. The investigated groups presented distinct metabolic profiles, in which the main differential metabolites found in the serum sample of bipolar disorder patients compared with those from controls were lipids, lipid metabolism-related molecules (choline, myo-inositol), and some amino acids (N-acetyl-L-phenyl alanine, N-acetyl-L-aspartyl-L-glutamic acid, L-glutamine). In addition, amygdalin, α-ketoglutaric acid, and lipoamide, among other compounds, were also present or were significantly altered in the serum of bipolar disorder patients. The data presented herein suggest that some of these metabolites differentially distributed between the groups studied may be directly related to the bipolar disorder pathophysiology. The strategy employed here showed significant potential for exploring pathophysiological features and molecular pathways involved in bipolar disorder. Thus, our findings may contribute to pave the way for future studies aiming at identifying important potential biomarkers for bipolar disorder diagnosis or progression follow-up.
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Global climate change, war, and population decline in recent human history.
Zhang, David D; Brecke, Peter; Lee, Harry F; He, Yuan-Qing; Zhang, Jane
2007-12-04
Although scientists have warned of possible social perils resulting from climate change, the impacts of long-term climate change on social unrest and population collapse have not been quantitatively investigated. In this study, high-resolution paleo-climatic data have been used to explore at a macroscale the effects of climate change on the outbreak of war and population decline in the preindustrial era. We show that long-term fluctuations of war frequency and population changes followed the cycles of temperature change. Further analyses show that cooling impeded agricultural production, which brought about a series of serious social problems, including price inflation, then successively war outbreak, famine, and population decline successively. The findings suggest that worldwide and synchronistic war-peace, population, and price cycles in recent centuries have been driven mainly by long-term climate change. The findings also imply that social mechanisms that might mitigate the impact of climate change were not significantly effective during the study period. Climate change may thus have played a more important role and imposed a wider ranging effect on human civilization than has so far been suggested. Findings of this research may lend an additional dimension to the classic concepts of Malthusianism and Darwinism.
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Comparison of NMR and crystal structures for the proteins TM1112 and TM1367
International Nuclear Information System (INIS)
Mohanty, Biswaranjan; Serrano, Pedro; Pedrini, Bill; Jaudzems, Kristaps; Geralt, Michael; Horst, Reto; Herrmann, Torsten; Elsliger, Marc-André; Wilson, Ian A.; Wüthrich, Kurt
2010-01-01
determination by NMR and by X-ray diffraction, respectively. The results thus obtained show that NMR structure calculations with the new automated UNIO software used by the JCSG compare favorably with those from a more labor-intensive and time-intensive interactive procedure. An intriguing observation is that the ‘bundles’ of two TM1112 or three TM1367 molecules in the asymmetric unit of the crystal structures mimic the behavior of the bundles of 20 conformers used to represent the NMR solution structures when comparing global r.m.s.d. values calculated either for the polypeptide backbone, the core residues with solvent accessibility below 15% or all heavy atoms
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Evaluating the links between climate, disease spread, and amphibian declines.
Rohr, Jason R; Raffel, Thomas R; Romansic, John M; McCallum, Hamish; Hudson, Peter J
2008-11-11
Human alteration of the environment has arguably propelled the Earth into its sixth mass extinction event and amphibians, the most threatened of all vertebrate taxa, are at the forefront. Many of the worldwide amphibian declines have been caused by the chytrid fungus, Batrachochytrium dendrobatidis (Bd), and two contrasting hypotheses have been proposed to explain these declines. Positive correlations between global warming and Bd-related declines sparked the chytrid-thermal-optimum hypothesis, which proposes that global warming increased cloud cover in warm years that drove the convergence of daytime and nighttime temperatures toward the thermal optimum for Bd growth. In contrast, the spatiotemporal-spread hypothesis states that Bd-related declines are caused by the introduction and spread of Bd, independent of climate change. We provide a rigorous test of these hypotheses by evaluating (i) whether cloud cover, temperature convergence, and predicted temperature-dependent Bd growth are significant positive predictors of amphibian extinctions in the genus Atelopus and (ii) whether spatial structure in the timing of these extinctions can be detected without making assumptions about the location, timing, or number of Bd emergences. We show that there is spatial structure to the timing of Atelopus spp. extinctions but that the cause of this structure remains equivocal, emphasizing the need for further molecular characterization of Bd. We also show that the reported positive multi-decade correlation between Atelopus spp. extinctions and mean tropical air temperature in the previous year is indeed robust, but the evidence that it is causal is weak because numerous other variables, including regional banana and beer production, were better predictors of these extinctions. Finally, almost all of our findings were opposite to the predictions of the chytrid-thermal-optimum hypothesis. Although climate change is likely to play an important role in worldwide amphibian declines
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International Nuclear Information System (INIS)
Pines, A.
1988-08-01
These lectures discuss some recent developments in pulsed NMR, emphasizing fundamental principles with selected illustrative applications. Major topics covered include multiple-quantum spectroscopy, spin decoupling, the interaction of spins with a quantized field, adiabatic rapid passage, spin temperature and statistics of cross-polarization, coherent averaging, and zero field NMR. 32 refs., 56 figs
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Solid-state NMR basic principles and practice
Apperley, David C; Hodgkinson, Paul
2014-01-01
Nuclear Magnetic Resonance (NMR) has proved to be a uniquely powerful and versatile tool for analyzing and characterizing chemicals and materials of all kinds. This book focuses on the latest developments and applications for "solid-state" NMR, which has found new uses from archaeology to crystallography to biomaterials and pharmaceutical science research. The book will provide materials engineers, analytical chemists, and physicists, in and out of lab, a survey of the techniques and the essential tools of solid-state NMR, together with a practical guide on applications. In this concise introduction to the growing field of solid-state nuclear magnetic resonance spectroscopy The reader will find: * Basic NMR concepts for solids, including guidance on the spin-1/2 nuclei concept * Coverage of the quantum mechanics aspects of solid state NMR and an introduction to the concept of quadrupolar nuclei * An understanding relaxation, exchange and quantitation in NMR * An analysis and interpretation of NMR data, with e...
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High resolution NMR theory and chemical applications
Becker, Edwin D
1999-01-01
High Resolution NMR provides a broad treatment of the principles and theory of nuclear magnetic resonance (NMR) as it is used in the chemical sciences. It is written at an "intermediate" level, with mathematics used to augment, rather than replace, clear verbal descriptions of the phenomena. The book is intended to allow a graduate student, advanced undergraduate, or researcher to understand NMR at a fundamental level, and to see illustrations of the applications of NMR to the determination of the structure of small organic molecules and macromolecules, including proteins. Emphasis is on the study of NMR in liquids, but the treatment also includes high resolution NMR in the solid state and the principles of NMR imaging and localized spectroscopy. Careful attention is given to developing and interrelating four approaches - steady state energy levels, the rotating vector picture, the density matrix, and the product operator formalism. The presentation is based on the assumption that the reader has an acquaintan...
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High resolution NMR spectroscopy of synthetic polymers in bulk
International Nuclear Information System (INIS)
Komorski, R.A.
1986-01-01
The contents of this book are: Overview of high-resolution NMR of solid polymers; High-resolution NMR of glassy amorphous polymers; Carbon-13 solid-state NMR of semicrystalline polymers; Conformational analysis of polymers of solid-state NMR; High-resolution NMR studies of oriented polymers; High-resolution solid-state NMR of protons in polymers; and Deuterium NMR of solid polymers. This work brings together the various approaches for high-resolution NMR studies of bulk polymers into one volume. Heavy emphasis is, of course, given to 13C NMR studies both above and below Tg. Standard high-power pulse and wide-line techniques are not covered
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International symposium on NMR spectroscopy
International Nuclear Information System (INIS)
The publication consists of 32 papers and presentations from the field of NMR spectroscopy applications submitted to the International Symposium on NMR Spectroscopy held at Smolenice between 29 Sep and 3 Oct, 1980. (B.S.)
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Oriented solid-state NMR spectrosocpy
DEFF Research Database (Denmark)
Bertelsen, Kresten
This thesis is concerned with driving forward oriented solid-state NMR spectroscopy as a viable technique for studying peptides in membrane bilayers. I will show that structural heterogeneity is an intrinsic part of the peptide/lipid system and that NMR can be used to characterize static...... and dynamic structural features of the peptides and its local surroundings. In fact one need to take into account the dynamical features of the system in order to correctly predict the structure from oriented solid-state NMR spectra. ...
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Continuous Flow 1H and 13C NMR Spectroscopy in Microfluidic Stripline NMR Chips
Oosthoek-de Vries, Anna Jo; Bart, Jacob; Tiggelaar, Roald M.; Janssen, Johannes W.G.; van Bentum, Jan (P.J.M.); Gardeniers, Han J.G.E.; Kentgens, Arno P.M.
2017-01-01
Microfluidic stripline NMR technology not only allows for NMR experiments to be performed on small sample volumes in the submicroliter range, but also experiments can easily be performed in continuous flow because of the stripline's favorable geometry. In this study we demonstrate the possibility of
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Rapid decline of the volcanically threatened Montserrat oriole.
Geoff M. Hilton; Phil W. Atkinson; Gerard A.L. Gray; Wayne J. Arendt; David W. Gibbons
2003-01-01
Prior to 1995, the Montserrat oriole (Icterus oberi) was confined to ca. 30 km2 of hill forest on the Lesser Antillean island of Montserrat, but was not listed as globally threatened. Since then, the eruption of the Soufriere Hills volcano has destroyed more than half of the speciesâ range. Recent intensive monitoring has indicated that the species has also declined...
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Directory of Open Access Journals (Sweden)
N. Hertkorn
2013-03-01
Full Text Available High-performance, non-target, high-resolution organic structural spectroscopy was applied to solid phase extracted marine dissolved organic matter (SPE-DOM isolated from four different depths in the open South Atlantic Ocean off the Angola coast (3° E, 18° S; Angola Basin and provided molecular level information with extraordinary coverage and resolution. Sampling was performed at depths of 5 m (Angola Current; near-surface photic zone, 48 m (Angola Current; fluorescence maximum, 200 m (still above Antarctic Intermediate Water, AAIW; upper mesopelagic zone and 5446 m (North Atlantic Deep Water, NADW; abyssopelagic, ~30 m above seafloor and produced SPE-DOM with near 40% carbon yield and beneficial nuclear magnetic resonance (NMR relaxation properties, a crucial prerequisite for the acquisition of NMR spectra with excellent resolution. 1H and 13C NMR spectra of all four marine SPE-DOM showed smooth bulk envelopes, reflecting intrinsic averaging from massive signal overlap, with a few percent of visibly resolved signatures and variable abundances for all major chemical environments. The abundance of singly oxygenated aliphatics and acetate derivatives in 1H NMR spectra declined from surface to deep marine SPE-DOM, whereas C-based aliphatics and carboxyl-rich alicyclic molecules (CRAM increased in abundance. Surface SPE-DOM contained fewer methyl esters than all other samples, likely a consequence of direct exposure to sunlight. Integration of 13C NMR spectra revealed continual increase of carboxylic acids and ketones from surface to depth, reflecting a progressive oxygenation, with concomitant decline of carbohydrate-related substructures. Aliphatic branching increased with depth, whereas the fraction of oxygenated aliphatics declined for methine, methylene and methyl carbon. Lipids in the oldest SPE-DOM at 5446 m showed a larger share of ethyl groups and methylene carbon than observed in the other samples. Two-dimensional NMR spectra showed
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Detection of site-specific binding and co-binding of ligands to macromolecules using 19F NMR
International Nuclear Information System (INIS)
Jenkins, B.G.
1991-01-01
Study of ligand-macromolecular interactions by 19 F nuclear magnetic resonance (NMR) spectroscopy affords many opportunities for obtaining molecular biochemical and pharmaceutical information. This is due to the absence of a background fluorine signal, as well as the relatively high sensitivity of 19 F NMR. Use of fluorine-labeled ligands enables one to probe not only binding and co-binding phenomena to macromolecules, but also can provide data on binding constants, stoichiometries, kinetics, and conformational properties of these complexes. Under conditions of slow exchange and macromolecule-induced chemical shifts, multiple 19 F NMR resonances can be observed for free and bound ligands. These shifted resonances are a direct correlate of the concentration of ligand bound in a specific state rather than the global concentrations of bound or free ligand which are usually determined using other techniques such as absorption spectroscopy or equilibrium dialysis. Examples of these interactions are demonstrated both from the literature and from interactions of 5-fluorotryptophan, 5-fluorosalicylic acid, flurbiprofen, and sulindac sulfide with human serum albumin. Other applications of 19 F NMR to study of these interactions in vivo, as well for receptor binding and metabolic tracing of fluorinated drugs and proteins are discussed
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Annual reports on NMR spectroscopy
Webb, Graham A; McCarthy, M J
1995-01-01
Over recent years, no other technique has grown to such importance as that of NMR spectroscopy. It is used in all branches of science where precise structural determination is required and where the nature of interactions and reactions in solution is being studied. Annual Reports on NMR Spectroscopy has established itself as a means for the specialist and non-specialist alike to become familiar with new applications of the technique in all branches of chemistry, including biochemistry, and pharmaceutics. This volume focuses on theoretical aspects of NMR nuclear shielding and on applications of
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Schreckenbach, Georg
2002-12-16
In this and a previous article (J. Phys. Chem. A 2000, 104, 8244), the range of application for relativistic density functional theory (DFT) is extended to the calculation of nuclear magnetic resonance (NMR) shieldings and chemical shifts in diamagnetic actinide compounds. Two relativistic DFT methods are used, ZORA ("zeroth-order regular approximation") and the quasirelativistic (QR) method. In the given second paper, NMR shieldings and chemical shifts are calculated and discussed for a wide range of compounds. The molecules studied comprise uranyl complexes, [UO(2)L(n)](+/-)(q); UF(6); inorganic UF(6) derivatives, UF(6-n)Cl(n), n = 0-6; and organometallic UF(6) derivatives, UF(6-n)(OCH(3))(n), n = 0-5. Uranyl complexes include [UO(2)F(4)](2-), [UO(2)Cl(4)](2-), [UO(2)(OH)(4)](2-), [UO(2)(CO(3))(3)](4-), and [UO(2)(H(2)O)(5)](2+). For the ligand NMR, moderate (e.g., (19)F NMR chemical shifts in UF(6-n)Cl(n)) to excellent agreement [e.g., (19)F chemical shift tensor in UF(6) or (1)H NMR in UF(6-n)(OCH(3))(n)] has been found between theory and experiment. The methods have been used to calculate the experimentally unknown (235)U NMR chemical shifts. A large chemical shift range of at least 21,000 ppm has been predicted for the (235)U nucleus. ZORA spin-orbit appears to be the most accurate method for predicting actinide metal chemical shifts. Trends in the (235)U NMR chemical shifts of UF(6-n)L(n) molecules are analyzed and explained in terms of the calculated electronic structure. It is argued that the energy separation and interaction between occupied and virtual orbitals with f-character are the determining factors.
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2D COSY sup 1 H NMR; A new tool for studying in sity brain metabolism in the living animal
Energy Technology Data Exchange (ETDEWEB)
Barrere, B.; Peres, M.; Seulaz, J. (Universite Paris 7 (France). Laboratoire de Physiologie et Physiopathologie Cerebrovasculaire INSERM U 182 CNRS UA 641, Paris (France)); Gillet, B.; Mergui, S.; Beloeil, J.-C. (Centre National de la Recherche Scientifique, 91 - Gif-sur-Yvette (France). Inst. de Chimie des Substances Naturelles)
1990-05-21
2D COSY {sup 1}H NMR with surface coil has been used to resolve and assign cerebral metabolites which had previously been detected but could not be resolved or assigned in situ in the living animal by conventional 1D {sup 1}H NMR. A wide range of cerebral metabolites, including alanine, N-acetyl asparate, asparate, choline derivatives, creatine/phosphocreatine pool, GABA, glucose, glutamate/glutamine pool, inositol, lactate and taurine were simultaneously resolved and assigned in situ in the whole animal using the 2D COSY correlation graphs. Global irreversible ischemia caused the appearance and the disappearance of cross-peaks in the 2D COSY {sup 1}H NMR map, corresponding to increases in alanine, GABA and lactate and glucose depletion. (author). 21 refs.; 3 figs.
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Solid-state NMR spectroscopy on complex biomolecules
Renault, M.A.M.; Cukkemane, A.A.; Baldus, M.
2010-01-01
Biomolecular applications of NMR spectroscopy are often merely associated with soluble molecules or magnetic resonance imaging. However, since the late 1970s, solid-state NMR (ssNMR) spectroscopy has demonstrated its ability to provide atomic-level insight into complex biomolecular systems ranging
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International Nuclear Information System (INIS)
Matsumura, Kiichiro; Nakano, Imaharu; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio.
1986-01-01
Proton NMR-CT (magnetic field strength 0.1 Tesla, resonant frequency 4.5 MHz) was performed in 15 normal (NC) and 20 Duchenne muscular dystrophy (DMD) males. The age ranged from 3 to 47 years for the NC males, and 1 to 14 years for the DMD males. In the DMD group there were one subclinical stage, 4 stage 1, 6 stage 2, 4 stage 3, and 5 stage 5 or higher patients. T 1 (longitudinal relaxation) images were obtained for three slices at the buttock, midthigh, and calf levels. The T 1 values were measured for the medial portion of the gluteus maximus, the vastus lateralis of the quadriceps femoris, the adductors, the sartorius, the gracilis, and the gastrocnemius muscles. Bound water fraction (BWF) was calculated from Fullerton's equation based on the fast diffusion model. The following results were obtained: (1) In the NC group, muscle T 1 values declined gradually with maturation under the age of 10, and became constant beyond that. The average T 1 value was 280 ms for the age group between 3 and 6 years, 270 ms for 7 and 10 years, and 260 ms for those older than 10 years. (2) Muscle BWF increased with maturation in the NC group. (3) In the DMD group, T 1 values were initially higher than normal (300 ms), declined rapidly with the progress of the disease, and reached the same low level as the subcutaneous fat (190 ms). (4) This decrease of T 1 value in DMD was not uniform for all muscles, being most prominent in the gluteus maximus and least so in the sartorius and gracilis. (5) In the early stages of DMD, the BWF was lower than normal. (J.P.N.)
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Integrative NMR for biomolecular research
International Nuclear Information System (INIS)
Lee, Woonghee; Cornilescu, Gabriel; Dashti, Hesam; Eghbalnia, Hamid R.; Tonelli, Marco; Westler, William M.; Butcher, Samuel E.; Henzler-Wildman, Katherine A.; Markley, John L.
2016-01-01
NMR spectroscopy is a powerful technique for determining structural and functional features of biomolecules in physiological solution as well as for observing their intermolecular interactions in real-time. However, complex steps associated with its practice have made the approach daunting for non-specialists. We introduce an NMR platform that makes biomolecular NMR spectroscopy much more accessible by integrating tools, databases, web services, and video tutorials that can be launched by simple installation of NMRFAM software packages or using a cross-platform virtual machine that can be run on any standard laptop or desktop computer. The software package can be downloaded freely from the NMRFAM software download page ( http://pine.nmrfam.wisc.edu/download-packages.html http://pine.nmrfam.wisc.edu/download_packages.html ), and detailed instructions are available from the Integrative NMR Video Tutorial page ( http://pine.nmrfam.wisc.edu/integrative.html http://pine.nmrfam.wisc.edu/integrative.html ).
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Integrative NMR for biomolecular research
Energy Technology Data Exchange (ETDEWEB)
Lee, Woonghee, E-mail: whlee@nmrfam.wisc.edu; Cornilescu, Gabriel; Dashti, Hesam; Eghbalnia, Hamid R.; Tonelli, Marco; Westler, William M.; Butcher, Samuel E.; Henzler-Wildman, Katherine A.; Markley, John L., E-mail: markley@nmrfam.wisc.edu [University of Wisconsin-Madison, National Magnetic Resonance Facility at Madison and Biochemistry Department (United States)
2016-04-15
NMR spectroscopy is a powerful technique for determining structural and functional features of biomolecules in physiological solution as well as for observing their intermolecular interactions in real-time. However, complex steps associated with its practice have made the approach daunting for non-specialists. We introduce an NMR platform that makes biomolecular NMR spectroscopy much more accessible by integrating tools, databases, web services, and video tutorials that can be launched by simple installation of NMRFAM software packages or using a cross-platform virtual machine that can be run on any standard laptop or desktop computer. The software package can be downloaded freely from the NMRFAM software download page ( http://pine.nmrfam.wisc.edu/download-packages.html http://pine.nmrfam.wisc.edu/download{sub p}ackages.html ), and detailed instructions are available from the Integrative NMR Video Tutorial page ( http://pine.nmrfam.wisc.edu/integrative.html http://pine.nmrfam.wisc.edu/integrative.html ).
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Quartz Crystal Temperature Sensor for MAS NMR
Simon, Gerald
1997-10-01
Quartz crystal temperature sensors (QCTS) were tested for the first time as wireless thermometers in NMR MAS rotors utilizing the NMR RF technique itself for exiting and receiving electro-mechanical quartz resonances. This new tool in MAS NMR has a high sensitivity, linearity, and precision. When compared to the frequently used calibration of the variable temperature in the NMR system by a solid state NMR chemical shift thermometer (CST), such as lead nitrate, QCTS shows a number of advantages. It is an inert thermometer in close contact with solid samples operating parallel to the NMR experiment. QCTS can be manufactured for any frequency to be near a NMR frequency of interest (typically 1 to 2 MHz below or above). Due to the strong response of the crystal, signal detection is possible without changing the tuning of the MAS probe. The NMR signal is not influenced due to the relative sharp crystal resonance, restricted excitation by finite pulses, high probeQvalues, and commonly used audio filters. The quadratic dependence of the temperature increase on spinning speed is the same for the QCTS and for the CST lead nitrate and is discussed in terms of frictional heat in accordance with the literature about lead nitrate and with the results of a simple rotor speed jump experiment with differently radial located lead nitrate in the rotor.
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Basics of spectroscopic instruments. Hardware of NMR spectrometer
International Nuclear Information System (INIS)
Sato, Hajime
2009-01-01
NMR is a powerful tool for structure analysis of small molecules, natural products, biological macromolecules, synthesized polymers, samples from material science and so on. Magnetic Resonance Imaging (MRI) is applicable to plants and animals Because most of NMR experiments can be done by an automation mode, one can forget hardware of NMR spectrometers. It would be good to understand features and performance of NMR spectrometers. Here I present hardware of a modern NMR spectrometer which is fully equipped with digital technology. (author)
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33S NMR cryogenic probe for taurine detection
Hobo, Fumio; Takahashi, Masato; Maeda, Hideaki
2009-03-01
With the goal of a S33 nuclear magnetic resonance (NMR) probe applicable to in vivo NMR on taurine-biological samples, we have developed the S33 NMR cryogenic probe, which is applicable to taurine solutions. The NMR sensitivity gain relative to a conventional broadband probe is as large as 3.5. This work suggests that improvements in the preamplifier could allow NMR measurements on 100 μM taurine solutions, which is the level of sensitivity necessary for biological samples.
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Rapid prediction of multi-dimensional NMR data sets
International Nuclear Information System (INIS)
Gradmann, Sabine; Ader, Christian; Heinrich, Ines; Nand, Deepak; Dittmann, Marc; Cukkemane, Abhishek; Dijk, Marc van; Bonvin, Alexandre M. J. J.; Engelhard, Martin; Baldus, Marc
2012-01-01
We present a computational environment for Fast Analysis of multidimensional NMR DAta Sets (FANDAS) that allows assembling multidimensional data sets from a variety of input parameters and facilitates comparing and modifying such “in silico” data sets during the various stages of the NMR data analysis. The input parameters can vary from (partial) NMR assignments directly obtained from experiments to values retrieved from in silico prediction programs. The resulting predicted data sets enable a rapid evaluation of sample labeling in light of spectral resolution and structural content, using standard NMR software such as Sparky. In addition, direct comparison to experimental data sets can be used to validate NMR assignments, distinguish different molecular components, refine structural models or other parameters derived from NMR data. The method is demonstrated in the context of solid-state NMR data obtained for the cyclic nucleotide binding domain of a bacterial cyclic nucleotide-gated channel and on membrane-embedded sensory rhodopsin II. FANDAS is freely available as web portal under WeNMR (http://www.wenmr.eu/services/FANDAShttp://www.wenmr.eu/services/FANDAS).
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Rapid prediction of multi-dimensional NMR data sets
Energy Technology Data Exchange (ETDEWEB)
Gradmann, Sabine; Ader, Christian [Utrecht University, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands); Heinrich, Ines [Max Planck Institute for Molecular Physiology, Department of Physical Biochemistry (Germany); Nand, Deepak [Utrecht University, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands); Dittmann, Marc [Max Planck Institute for Molecular Physiology, Department of Physical Biochemistry (Germany); Cukkemane, Abhishek; Dijk, Marc van; Bonvin, Alexandre M. J. J. [Utrecht University, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands); Engelhard, Martin [Max Planck Institute for Molecular Physiology, Department of Physical Biochemistry (Germany); Baldus, Marc, E-mail: m.baldus@uu.nl [Utrecht University, Faculty of Science, Bijvoet Center for Biomolecular Research (Netherlands)
2012-12-15
We present a computational environment for Fast Analysis of multidimensional NMR DAta Sets (FANDAS) that allows assembling multidimensional data sets from a variety of input parameters and facilitates comparing and modifying such 'in silico' data sets during the various stages of the NMR data analysis. The input parameters can vary from (partial) NMR assignments directly obtained from experiments to values retrieved from in silico prediction programs. The resulting predicted data sets enable a rapid evaluation of sample labeling in light of spectral resolution and structural content, using standard NMR software such as Sparky. In addition, direct comparison to experimental data sets can be used to validate NMR assignments, distinguish different molecular components, refine structural models or other parameters derived from NMR data. The method is demonstrated in the context of solid-state NMR data obtained for the cyclic nucleotide binding domain of a bacterial cyclic nucleotide-gated channel and on membrane-embedded sensory rhodopsin II. FANDAS is freely available as web portal under WeNMR (http://www.wenmr.eu/services/FANDAShttp://www.wenmr.eu/services/FANDAS).
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Solution NMR Spectroscopy in Target-Based Drug Discovery.
Li, Yan; Kang, Congbao
2017-08-23
Solution NMR spectroscopy is a powerful tool to study protein structures and dynamics under physiological conditions. This technique is particularly useful in target-based drug discovery projects as it provides protein-ligand binding information in solution. Accumulated studies have shown that NMR will play more and more important roles in multiple steps of the drug discovery process. In a fragment-based drug discovery process, ligand-observed and protein-observed NMR spectroscopy can be applied to screen fragments with low binding affinities. The screened fragments can be further optimized into drug-like molecules. In combination with other biophysical techniques, NMR will guide structure-based drug discovery. In this review, we describe the possible roles of NMR spectroscopy in drug discovery. We also illustrate the challenges encountered in the drug discovery process. We include several examples demonstrating the roles of NMR in target-based drug discoveries such as hit identification, ranking ligand binding affinities, and mapping the ligand binding site. We also speculate the possible roles of NMR in target engagement based on recent processes in in-cell NMR spectroscopy.
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Cued memory decline in biomarker-defined preclinical Alzheimer disease.
Papp, Kathryn V; Rentz, Dorene M; Mormino, Elizabeth C; Schultz, Aaron P; Amariglio, Rebecca E; Quiroz, Yakeel; Johnson, Keith A; Sperling, Reisa A
2017-04-11
To determine whether a decline in cued recall is observable in the preclinical stage of Alzheimer disease (AD) in clinically normal older adults with elevated β-amyloid (Aβ) burden on PET imaging. Clinically normal older adults underwent baseline neuroimaging (PET to assess Aβ +/- status and MRI) and annual neuropsychological testing. Cox proportional hazards models were used to assess the relative risk of cued memory decline (drop of 1, 2, 3, or 4 points on the total score of the Free and Cued Selective Reminding Test) in relation to neuroimaging measures, functional status, age, sex, and education. A total of 276 older adults (Clinical Dementia Rating = 0, mean Mini-Mental State Examination score = 29 ± 1.06) were followed up for a mean of 3.6 ± 1.2 years. Despite the infrequency of cued memory decline (only 19% of participants scored ≤46/48 in total recall by year 3), Aβ + participants were 3.55 times (95% confidence interval = 1.77-7.12) more likely to exhibit decline in total recall (≤46/48) compared with their Aβ - peers. Furthermore, Aβ + participants who scored ≤46/48 had smaller hippocampal volumes ( t = 3.37, p = 0.001) and evidence of early functional decline, i.e., greater risk of progression to global Clinical Dementia Rating of 0.5 (χ 2 = 14.30, p recall. Cued memory decline in healthy older adults may be particularly indicative of Aβ-related decline during the preclinical stage of AD and useful for identifying Aβ + clinically normal individuals at greatest risk of short-term clinical progression. © 2017 American Academy of Neurology.
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NMR imaging of osteoarticular pathology
International Nuclear Information System (INIS)
Frocrain, L.; Duvauferrier, R.; Gagey, N.
1987-01-01
NMR imaging is assuming an increasingly important role in the diagnosis of osteo-articular disorders. Semiological descriptions of the mean pathological disorders of the locomotor system are presented. Some investigation strategies are proposed to compare NMR imaging with other imaging techniques in various pathological states [fr
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NMR structure of the protein NP-247299.1: comparison with the crystal structure
International Nuclear Information System (INIS)
Jaudzems, Kristaps; Geralt, Michael; Serrano, Pedro; Mohanty, Biswaranjan; Horst, Reto; Pedrini, Bill; Elsliger, Marc-André; Wilson, Ian A.; Wüthrich, Kurt
2010-01-01
Comparison of the NMR and crystal structures of a protein determined using largely automated methods has enabled the interpretation of local differences in the highly similar structures. These differences are found in segments of higher B values in the crystal and correlate with dynamic processes on the NMR chemical shift timescale observed in solution. The NMR structure of the protein NP-247299.1 in solution at 313 K has been determined and is compared with the X-ray crystal structure, which was also solved in the Joint Center for Structural Genomics (JCSG) at 100 K and at 1.7 Å resolution. Both structures were obtained using the current largely automated crystallographic and solution NMR methods used by the JCSG. This paper assesses the accuracy and precision of the results from these recently established automated approaches, aiming for quantitative statements about the location of structure variations that may arise from either one of the methods used or from the different environments in solution and in the crystal. To evaluate the possible impact of the different software used for the crystallographic and the NMR structure determinations and analysis, the concept is introduced of reference structures, which are computed using the NMR software with input of upper-limit distance constraints derived from the molecular models representing the results of the two structure determinations. The use of this new approach is explored to quantify global differences that arise from the different methods of structure determination and analysis versus those that represent interesting local variations or dynamics. The near-identity of the protein core in the NMR and crystal structures thus provided a basis for the identification of complementary information from the two different methods. It was thus observed that locally increased crystallographic B values correlate with dynamic structural polymorphisms in solution, including that the solution state of the protein involves
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Development and applications of quantitative NMR spectroscopy
International Nuclear Information System (INIS)
Yamazaki, Taichi
2016-01-01
Recently, quantitative NMR spectroscopy has attracted attention as an analytical method which can easily secure traceability to SI unit system, and discussions about its accuracy and inaccuracy are also started. This paper focuses on the literatures on the advancement of quantitative NMR spectroscopy reported between 2009 and 2016, and introduces both NMR measurement conditions and actual analysis cases in quantitative NMR. The quantitative NMR spectroscopy using an internal reference method enables accurate quantitative analysis with a quick and versatile way in general, and it is possible to obtain the precision sufficiently applicable to the evaluation of pure substances and standard solutions. Since the external reference method can easily prevent contamination to samples and the collection of samples, there are many reported cases related to the quantitative analysis of biologically related samples and highly scarce natural products in which NMR spectra are complicated. In the precision of quantitative NMR spectroscopy, the internal reference method is superior. As the quantitative NMR spectroscopy widely spreads, discussions are also progressing on how to utilize this analytical method as the official methods in various countries around the world. In Japan, this method is listed in the Pharmacopoeia and Japanese Standard of Food Additives, and it is also used as the official method for purity evaluation. In the future, this method will be expected to spread as the general-purpose analysis method that can ensure traceability to SI unit system. (A.O.)
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Study on the Effects of Oligo chitosan and Bioliquifert on Two Rice Mutants, NMR 151 and NMR 152
International Nuclear Information System (INIS)
Shakinah Salleh; Faiz Ahmad; Sobri Hussein
2016-01-01
Nuclear Malaysia has successfully developed two new rice mutants namely NMR 151 and NMR 152. In addition, Nuclear Malaysia has also successfully developed Oligo chitosan and liquid bio fertilizer (Bioliquifert). Oligo chitosan acts as elicitor that has been proven to be very effective in controlling disease infections and improving yield productivity. Bioliquifert on the other hand is a mixture of microbes containing major nutrient-providing microorganisms. The objective of this study is to observe the effects of Oligo chitosan and Bioliquifert on rice mutants, NMR 151 and NMR 152. The treatment was applied on 14 day old seedlings of MR 219, NMR 151 and NMR 152 sowed in 20 cm pots containing silty clay from the paddy soil of Tanjung Karang, Selangor. The seedlings were then placed in the greenhouse at Nuclear Malaysia until it reaches 110 days old. Study was conducted in a Complete Randomized Design (CRD) with 3 replications was used and each replication consisted of three plants. All treatments received compound and single dressing fertilizer as recommended by National Rice Production Package except for Treatment 2 and 3, in which Treatment 2 received Oligo chitosan and Bioliquifert while Treatment 3 only received Bioliquifert. Results on plant height, number of tiller and plant fresh weight are not significantly different for all cultivar except for seed dry weight of NMR 152 and MR 219. (author)
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Long-term decline of the Amazon carbon sink.
Brienen, R J W; Phillips, O L; Feldpausch, T R; Gloor, E; Baker, T R; Lloyd, J; Lopez-Gonzalez, G; Monteagudo-Mendoza, A; Malhi, Y; Lewis, S L; Vásquez Martinez, R; Alexiades, M; Álvarez Dávila, E; Alvarez-Loayza, P; Andrade, A; Aragão, L E O C; Araujo-Murakami, A; Arets, E J M M; Arroyo, L; Aymard C, G A; Bánki, O S; Baraloto, C; Barroso, J; Bonal, D; Boot, R G A; Camargo, J L C; Castilho, C V; Chama, V; Chao, K J; Chave, J; Comiskey, J A; Cornejo Valverde, F; da Costa, L; de Oliveira, E A; Di Fiore, A; Erwin, T L; Fauset, S; Forsthofer, M; Galbraith, D R; Grahame, E S; Groot, N; Hérault, B; Higuchi, N; Honorio Coronado, E N; Keeling, H; Killeen, T J; Laurance, W F; Laurance, S; Licona, J; Magnussen, W E; Marimon, B S; Marimon-Junior, B H; Mendoza, C; Neill, D A; Nogueira, E M; Núñez, P; Pallqui Camacho, N C; Parada, A; Pardo-Molina, G; Peacock, J; Peña-Claros, M; Pickavance, G C; Pitman, N C A; Poorter, L; Prieto, A; Quesada, C A; Ramírez, F; Ramírez-Angulo, H; Restrepo, Z; Roopsind, A; Rudas, A; Salomão, R P; Schwarz, M; Silva, N; Silva-Espejo, J E; Silveira, M; Stropp, J; Talbot, J; ter Steege, H; Teran-Aguilar, J; Terborgh, J; Thomas-Caesar, R; Toledo, M; Torello-Raventos, M; Umetsu, R K; van der Heijden, G M F; van der Hout, P; Guimarães Vieira, I C; Vieira, S A; Vilanova, E; Vos, V A; Zagt, R J
2015-03-19
Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.
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Shishmarev, Dmitry; Wright, Alan J; Rodrigues, Tiago B; Pileio, Giuseppe; Stevanato, Gabriele; Brindle, Kevin M; Kuchel, Philip W
2018-03-01
Fumarate is an important probe of metabolism in hyperpolarized magnetic resonance imaging and spectroscopy. It is used to detect the release of fumarase in cancer tissues, which is associated with necrosis and drug treatment. Nevertheless, there are limited reports describing the detailed kinetic studies of this enzyme in various cells and tissues. Thus, we aimed to evaluate the sub-minute kinetics of human red blood cell fumarase using nuclear magnetic resonance (NMR) spectroscopy, and to provide a quantitative description of the enzyme that is relevant to the use of fumarate as a probe of cell rupture. The fumarase reaction was studied using time courses of 1 H spin-echo and 13 C-NMR spectra. 1 H-NMR experiments showed that the fumarase reaction in hemolysates is sufficiently rapid to make its kinetics amenable to study in a period of approximately 3 min, a timescale characteristic of hyperpolarized 13 C-NMR spectroscopy. The rapid-dissolution dynamic nuclear polarization (RD-DNP) technique was used to hyperpolarize [1,4- 13 C]fumarate, which was injected into concentrated hemolysates. The kinetic data were analyzed using recently developed FmR α analysis and modeling of the enzymatic reaction using Michaelis-Menten equations. In RD-DNP experiments, the decline in the 13 C-NMR signal from fumarate, and the concurrent rise and fall of that from malate, were captured with high spectral resolution and signal-to-noise ratio, which allowed the robust quantification of fumarase kinetics. The kinetic parameters obtained indicate the potential contribution of hemolysis to the overall rate of the fumarase reaction when 13 C-NMR RD-DNP is used to detect necrosis in animal models of implanted tumors. The analytical procedures developed will be applicable to studies of other rapid enzymatic reactions using conventional and hyperpolarized substrate NMR spectroscopy. Copyright © 2018 John Wiley & Sons, Ltd.
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Whole-core analysis by 13C NMR
International Nuclear Information System (INIS)
Vinegar, H.J.; Tutunjian, P.N.; Edelstein, W.A.; Roemer, P.B.
1991-01-01
This paper reports on a whole-core nuclear magnetic resonance (NMR) system that was used to obtain natural abundance 13 C spectra. The system enables rapid, nondestructive measurements of bulk volume of movable oil, aliphatic/aromatic ratio, oil viscosity, and organic vs. carbonate carbon. 13 C NMR can be used in cores where the 1 H NMR spectrum is too broad to resolve oil and water resonances separately. A 5 1/4-in. 13 C/ 1 H NMR coil was installed on a General Electric (GE) CSI-2T NMR imager/spectrometer. With a 4-in.-OD whole core, good 13 C signal/noise ratio (SNR) is obtained within minutes, while 1 H spectra are obtained in seconds. NMR measurements have been made of the 13 C and 1 H density of crude oils with a wide range of API gravities. For light- and medium-gravity oils, the 13 C and 1 H signal per unit volume is constant within about 3.5%. For heavy crudes, the 13 C and 1 H density measured by NMR is reduced by the shortening of spin-spin relaxation time. 13 C and 1 H NMR spin-lattice relaxation times were measured on a suite of Cannon viscosity standards, crude oils (4 to 60 degrees API), and alkanes (C 5 through C 16 ) with viscosities at 77 degrees F ranging from 0.5 cp to 2.5 x 10 7 cp. The 13 C and 1 H relaxation times show a similar correlation with viscosity from which oil viscosity can be estimated accurately for viscosities up to 100 cp. The 13 C surface relaxation rate for oils on water-wet rocks is very low. Nonproton decoupled 13 C NMR is shown to be insensitive to kerogen; thus, 13 C NMR measures only the movable hydrocarbon content of the cores. In carbonates, the 13 C spectrum also contains a carbonate powder pattern useful in quantifying inorganic carbon and distinguishing organic from carbonate carbon
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Thinking outside the mainstream; Canadian NGL plants face global competition and decline
International Nuclear Information System (INIS)
Jaremko, D.
2005-01-01
The nature of the natural gas liquids (NGL) market, and the future prospects of the Canadian NGL industry are discussed. In the short term, demand for NGLs like propane, ethane and condensate is up, the supply picture is good, and the profit margins for Canadian gas plants look positive. At the same time, staying competitive with oil-based naptha and global NGL imports is expected to become more difficult, and the longer term future is far from being without significant problems. Competition is likely to grow as the Canadian energy industry is increasingly looking to heavy oil and bitumen to meet coming energy demand needs; given that it takes about a thousand cubic feet of natural gas to produce each barrel of oil from the oilsands, serious impact on natural gas availability is inevitable, which in turn will affect the supply of NGLs. To reduce the pressure on natural gas, there is an urgent need to come up with other sources of heavy oil production; various options such as coal, nuclear power and even coal gasification are being investigated, albeit too slowly to arrest the decline of North American conventional gas production that started in 2001. Expert opinion is that the real hope for the NGL industry, as well as for the future of natural gas, is the stranded reserve in the Arctic which, however, is expected to flow soon from the Mackenzie Delta. While Arctic gas is expected to negate the impact of waterborne imports from other countries by the USA, the absence of overseas imports does not alter the fact that North America as a petrochemical manufacturer is no longer as competitive with other countries as it once was. The unpleasant reality is that new petrochemical plants are more likely to be built in the Far East and China, where both the feedstock as well as the labour, are much cheaper. 3 photos
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An Inversion Recovery NMR Kinetics Experiment
Williams, Travis J.; Kershaw, Allan D.; Li, Vincent; Wu, Xinping
2011-01-01
A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this article will enable instructors to use inversion recovery as a laboratory activity in applied NMR classes and provide research students with a conveni...
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Recommendations of the wwPDB NMR Validation Task Force
Montelione, Gaetano T.; Nilges, Michael; Bax, Ad; Güntert, Peter; Herrmann, Torsten; Richardson, Jane S.; Schwieters, Charles; Vranken, Wim F.; Vuister, Geerten W.; Wishart, David S.; Berman, Helen M.; Kleywegt, Gerard J.; Markley, John L.
2013-01-01
As methods for analysis of biomolecular structure and dynamics using nuclear magnetic resonance spectroscopy (NMR) continue to advance, the resulting 3D structures, chemical shifts, and other NMR data are broadly impacting biology, chemistry, and medicine. Structure model assessment is a critical area of NMR methods development, and is an essential component of the process of making these structures accessible and useful to the wider scientific community. For these reasons, the Worldwide Protein Data Bank (wwPDB) has convened an NMR Validation Task Force (NMR-VTF) to work with the wwPDB partners in developing metrics and policies for biomolecular NMR data harvesting, structure representation, and structure quality assessment. This paper summarizes the recommendations of the NMR-VTF, and lays the groundwork for future work in developing standards and metrics for biomolecular NMR structure quality assessment. PMID:24010715
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International Nuclear Information System (INIS)
Hallenga, K.
1991-01-01
This paper discusses the concept of Fourier transformation one of the many precious legacies of the French mathematician Jean Baptiste Joseph Fourier, essential for understanding the link between continuous-wave (CW) and Fourier transform (FT) NMR. Although in modern FT NMR the methods used to obtain a frequency spectrum from the time-domain signal may vary greatly, from the efficient Cooley-Tukey algorithm to very elaborate iterative least-square methods based other maximum entropy method or on linear prediction, the principles for Fourier transformation are unchanged and give invaluable insight into the interconnection of many pairs of physical entities called Fourier pairs
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International Nuclear Information System (INIS)
Fukushima, E.; Assink, R.A.; Roeder, S.B.W.; Gibson, A.A.V.
1984-01-01
An improved nuclear magnetic resonance (NMR) apparatus for use in topical magnetic resonance (TMR) spectroscopy and other remote sensing NMR applications includes a semitoroidal radio frequency (rf) coil. The semitoroidal rf coil produces an effective alternating magnetic field at a distance from the poles of the coil, to enable NMR measurements to be taken from selected regions inside an object, particularly human and other living subjects. The semitoroidal rf coil is relatively insensitive to magnetic interference from metallic objects located behind the coil, thereby rendering the coil particularly suited for use in both conventional and superconducting NMR magnets. The semitoroidal NMR coil can be constructed so that it emits little or no excess rf electric field associated with the rf magnetic field, thus avoiding adverse effects due to dielectric heating of the sample or to any other electric field interactions. The coil may be combined with a like orthogonal coil and suitably driven to provide a circularly polarised field; or it may be used in conjunction with a concentrically nested smaller semitoroidal coil to move the maximum field further from the coil assembly. (author)
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Hertkorn, N.; Harir, M.; Koch, B. P.; Michalke, B.; Grill, P.; Schmitt-Kopplin, P.
2012-01-01
Non target high resolution organic structural spectroscopy of marine dissolved organic matter (DOM) isolated on 27 November 2008 by means of solid phase extraction (SPE) from four different depths in the South Atlantic Ocean off the Angola coast (3.1° E; -17.7° S; Angola basin) provided molecular level information of complex unknowns with unprecedented coverage and resolution. The sampling was intended to represent major characteristic oceanic regimes of general significance: 5 m (FISH; near surface photic zone), 48 m (FMAX; fluorescence maximum), 200 m (upper mesopelagic zone) and 5446 m (30 m above ground). 800 MHz proton (1H) nuclear magnetic resonance (NMR) 1H NMR, spectra were least affected by fast and differential transverse NMR relaxation and produced at first similar looking, rather smooth bulk NMR envelopes reflecting intrinsic averaging from massive signal overlap. Visibly resolved NMR signatures were most abundant in surface DOM but contributed at most a few percent to the total 1H NMR integral and were mainly limited to unsaturated and singly oxygenated carbon chemical environments. The relative abundance and variance of resolved signatures between samples was maximal in the aromatic region; in particular, the aromatic resolved NMR signature of the deep ocean sample at 5446 m was considerably different from that of all other samples. When scaled to equal total NMR integral, 1H NMR spectra of the four marine DOM samples revealed considerable variance in abundance for all major chemical environments across the entire range of chemical shift. Abundance of singly oxygenated CH units and acetate derivatives declined from surface to depth whereas aliphatics and carboxyl-rich alicyclic molecules (CRAM) derived molecules increased in abundance. Surface DOM contained a remarkably lesser abundance of methyl esters than all other marine DOM, likely a consequence of photodegradation from direct exposure to sunlight. All DOM showed similar overall 13C NMR
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International Nuclear Information System (INIS)
Agrawal, P.K.
1989-01-01
The present book has been written with the objective of introducing the organic chemists with the conceptual and experimental basis required for interpretation of 13 C NMR spectra of a flavonoid and to a discussion of general usefulness of the technique in solving flavonoid structural problem. After a brief general introduction to the essential aspects of flavonoids and 13 C NMR spectroscopy, considerable emphasis has been placed in chapter 2 on the various experimental methods and the interpretation of spectral details which enable individual resonance lines to be associated with the appropriate carbons in a molecule. The whole bulk of the literature, published on 13 C NMR of flavonoids in the major journals upto 1986 alongwith some recent references of 1987 has been classified in several categories such as: flavonoids, isflavonoids, other flavonoids, flavonoid glycosides, chalconoids and flavanoids. Each category constitutes a chapter. Finally the last chapter is devoted largely to a discussion for the differentiation of various categories and subcategories of flavonoids and for the establishment of aromatic substitution pattern in these compounds. It should be emphasized that the book is a data book and only concerned with the actual analysis of 13 C NMR spectra, thus a reasonable familiarity with basic instrumentation of 13 C NMR and general pattern of nuclear chemical shifts has been assumed. (author). refs.; figs.; tabs
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International Nuclear Information System (INIS)
Ouchi, Toshihiro; Steiner, R.E.
1984-01-01
Three epidermoid and two dermoid tumours, pathologically proven, were examined by NMR and CT scans. Although most brain tumours have a low signal with a long T 1 , a dermoid cyst and one of the two components of the other dermoid tumour had a high signal and therefore a short T 1 . All three epidermoid tumours had a low signal and a long T 1 . Because of the high level contrast between some of the tumours and cerebrospinal fluid, NMR is helpful to detect the lesion. Neither of the liquid fluid levels in the tumour cysts or floating fat in the subarachnoid space was recognized in one patients, but the fine leakage of the content from the epidermoid cyst into the lateral ventricle was detected on a saturation recovery 1000 image in one case. (author)
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The relationship of long term global temperature change and human fertility.
Fisch, Harry; Andrews, Howard F; Fisch, Karen S; Golden, Robert; Liberson, Gary; Olsson, Carl A
2003-07-01
According to the United Nations, global fertility has declined in the last century as reflected by a decline in birth rates. The earth's surface air temperature has increased considerably and is referred to as global warming. Since changes in temperature are well known to influence fertility we sought to determine if a statistical relationship exists between long-term changes in global air temperatures and birth rates. The most complete and reliable birth rate data in the 20th century was available in 19 industrialized countries. Using bivariate and multiple regression analysis, we compared yearly birth rates from these countries to global air temperatures from 1900 to 1994.A common pattern of change in birth rates was noted for the 19 industrialized countries studied. In general, birth rates declined markedly throughout the century except during the baby boom period of approximately 1940 to 1964. An inverse relationship was found between changes in global temperatures and birth rates in all 19 countries. Controlling for the linear yearly decline in birth rates over time, this relationship remained statistically significant for all the 19 countries in aggregate and in seven countries individually (phuman fertility may have been influenced by change in environmental temperatures.
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National Oceanic and Atmospheric Administration, Department of Commerce — Declination is calculated using the current International Geomagnetic Reference Field (IGRF) model. Declination is calculated using the current World Magnetic Model...
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Use of NMR and NMR Prediction Software to Identify Components in Red Bull Energy Drinks
Simpson, Andre J.; Shirzadi, Azadeh; Burrow, Timothy E.; Dicks, Andrew P.; Lefebvre, Brent; Corrin, Tricia
2009-01-01
A laboratory experiment designed as part of an upper-level undergraduate analytical chemistry course is described. Students investigate two popular soft drinks (Red Bull Energy Drink and sugar-free Red Bull Energy Drink) by NMR spectroscopy. With assistance of modern NMR prediction software they identify and quantify major components in each…
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NMR study of Albemoschus esculentus characterization
International Nuclear Information System (INIS)
Bathista, A.L.B.S; Silva, E.O.; Nogueira, Jose de S.; Tavares, M.I.B.
2001-01-01
The investigation of the main compounds presented in the Albemoschus esculentus has been carried out employing nuclear magnetic resonance spectroscopy (NMR), using solution and solid state NMR when it one was necessary. The evaluation of NMR data allowed us to characterize the main type of components presented in this kind of sample. It was necessary to use a total information from solid state NMR and also the solution response. From these information we could get that four main components were presented in this sample. One in the shell, that is cellulose, another one between the shell and seeds that is a polysaccharide and in the seed two components were found one is a starch and the second one is an oil, a triacylglycerol. These components are responsible by its physical chemistry properties. (author)
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NMR spectroscopy of coal pyrolysis products
Energy Technology Data Exchange (ETDEWEB)
Polonov, V.M.; Kalabin, G.A.; Kushnarev, D.F.; Shevchenko, G.G.
1985-12-01
The authors consider the scope for using H 1 and C 13 NMR spectroscopy to describe the products from coal pyrolysis and hydrogenization. The accuracy of the structural information provided by the best NMR methods is also considered. The stuctural parameters derived from H 1 and C 13 NMR spectra are presented. Results demonstrate the high accuracy and sensitivity of the structural information provided by H 1 AND C 13 NMR spectra for coal products. There are substantial structural differences between the soluble products from medium-temperature coking of Cheremkhov coal and high-speed pyrolysis of Kan-Acha coal, and also differences in behavior during hydrogenation. These differences are related to the structure of the organic matter in the initial coal and to differences in the pyrolysis mechanisms.
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Directory of Open Access Journals (Sweden)
Sengupta Arjun
2011-12-01
Full Text Available Abstract Background Plasmodium vivax is responsible for the majority of malarial infection in the Indian subcontinent. This species of the parasite is generally believed to cause a relatively benign form of the disease. However, recent reports from different parts of the world indicate that vivax malaria can also have severe manifestation. Host response to the parasite invasion is thought to be an important factor in determining the severity of manifestation. In this paper, attempt was made to determine the host metabolic response associated with P. vivax infection by means of NMR spectroscopy-based metabonomic techniques in an attempt to better understand the disease pathology. Methods NMR spectroscopy of urine samples from P. vivax-infected patients, healthy individuals and non-malarial fever patients were carried out followed by multivariate statistical analysis. Two data analysis techniques were employed, namely, Principal Component Analysis [PCA] and Orthogonal Projection to Latent Structure Discriminant Analysis [OPLS-DA]. Several NMR signals from the urinary metabolites were further selected for univariate comparison among the classes. Results The urine metabolic profiles of P. vivax-infected patients were distinct from those of healthy individuals as well as of non-malarial fever patients. A highly predictive model was constructed from urine profile of malarial and non-malarial fever patients. Several metabolites were found to be varying significantly across these cohorts. Urinary ornithine seems to have the potential to be used as biomarkers of vivax malaria. An increasing trend in pipecolic acid was also observed. The results suggest impairment in the functioning of liver as well as impairment in urea cycle. Conclusions The results open up a possibility of non-invasive analysis and diagnosis of P. vivax using urine metabolic profile. Distinct variations in certain metabolites were recorded, and amongst these, ornithine may have the
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An approach for high-throughput structure determination of proteins by NMR spectroscopy
Energy Technology Data Exchange (ETDEWEB)
Medek, Ales; Olejniczak, Edward T.; Meadows, Robert P.; Fesik, Stephen W. [Abbott Laboratories, Pharmaceutical Discovery Division (United States)
2000-11-15
An approach is described for rapidly determining protein structures by NMR that utilizes proteins containing {sup 13}C-methyl labeled Val, Leu, and Ile ({delta}1) and protonated Phe and Tyr in a deuterated background. Using this strategy, the key NOEs that define the hydrophobic core and overall fold of the protein are easily obtained. NMR data are acquired using cryogenic probe technology which markedly reduces the spectrometer time needed for data acquisition. The approach is demonstrated by determining the overall fold of the antiapoptotic protein, Bcl-xL, from data collected in only 4 days. Refinement of the Bcl-xL structure to a backbone rmsd of 0.95 A was accomplished with data collected in an additional 3 days. A distance analysis of 180 different proteins and structure calculations using simulated data suggests that our method will allow the global folds of a wide variety of proteins to be determined.
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NMR spectroscopy and drug development
International Nuclear Information System (INIS)
Craik, D.; Munro, S.
1990-01-01
The use of nuclear magnetic resonance (NMR) spectroscopy for structural and conformational studies on drug molecules, the three-dimensional investigation of proteins structure and their interactions with ligands are discussed. In-vivo NMR studies of the effects of drugs on metabolism in perfused organs and whole animals are also briefly presented. 5 refs., ills
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Abou-Hamad, Edy; Bontemps, P.; Rikken, Geert L J A
2011-01-01
Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.
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Abou-Hamad, Edy
2011-09-01
Nuclear magnetic resonance (NMR) experiments in pulsed magnetic fields up to 30.4 T focused on 1H and 93Nb nuclei are reported. Here we discuss the advantage and limitation of pulsed field NMR and why this technique is able to become a promising research tool. © 2011 Elsevier Inc. All Rights Reserved.
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Two-dimensional NMR spectroscopy. Applications for chemists and biochemists
International Nuclear Information System (INIS)
Croasmun, W.R.; Carlson, R.M.K.
1987-01-01
Two-dimensional nuclear magnetic resonance spectroscopy (2-D NMR) has become a very powerful class of experiments (in the hands of an adept scientist) with broad adaptability to new situations. It is the product of a happy marriage between modern pulse FT-NMR technology, with its large memory and high-speed computers, and the physicists and chemists who love to manipulate spin systems. Basic 2-D experiments are now a standard capability of modern NMR spectrometers, and this timely book intends to make 2-D NMR users of those who are familiar with normal 1-D NMR. The 2-D NMR goal is correlation of the lines of the observed NMR spectrum with other properties of the system. This book deals with applications to high-resolution spectrum analysis, utilizing either coupling between the NMR-active nuclei or chemical exchange to perform the correlation. The coupling can be scalar (through bonds) or direct through space (within 5 A). The coupling may be homonuclear (between like nuclei) or heteronuclear
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PSYCHE Pure Shift NMR Spectroscopy.
Foroozandeh, Mohammadali; Morris, Gareth; Nilsson, Mathias
2018-03-13
Broadband homodecoupling techniques in NMR, also known as "pure shift" methods, aim to enhance spectral resolution by suppressing the effects of homonuclear coupling interactions to turn multiplet signals into singlets. Such techniques typically work by selecting a subset of "active" nuclear spins to observe, and selectively inverting the remaining, "passive", spins to reverse the effects of coupling. Pure Shift Yielded by Chirp Excitation (PSYCHE) is one such method; it is relatively recent, but has already been successfully implemented in a range of different NMR experiments. Paradoxically, PSYCHE is one of the trickiest of pure shift NMR techniques to understand but one of the easiest to use. Here we offer some insights into theoretical and practical aspects of the method, and into the effects and importance of the experimental parameters. Some recent improvements that enhance the spectral purity of PSYCHE spectra will be presented, and some experimental frameworks including examples in 1D and 2D NMR spectroscopy, for the implementation of PSYCHE will be introduced. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Push-through Direction Injectin NMR Automation
Nuclear magnetic resonance (NMR) and mass spectrometry (MS) are the two major spectroscopic techniques successfully used in metabolomics studies. The non-invasive, quantitative and reproducible characteristics make NMR spectroscopy an excellent technique for detection of endogeno...
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NMR reaction monitoring in flow synthesis.
Gomez, M Victoria; de la Hoz, Antonio
2017-01-01
Recent advances in the use of flow chemistry with in-line and on-line analysis by NMR are presented. The use of macro- and microreactors, coupled with standard and custom made NMR probes involving microcoils, incorporated into high resolution and benchtop NMR instruments is reviewed. Some recent selected applications have been collected, including synthetic applications, the determination of the kinetic and thermodynamic parameters and reaction optimization, even in single experiments and on the μL scale. Finally, software that allows automatic reaction monitoring and optimization is discussed.
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Demography, Growth, and Global Income Inequality
Rougoor, Ward; Van Marrewijk, Charles
2015-01-01
Global income inequality has been declining for several decades. We argue that global income inequality will reach its lowest level around 2027 and then will rise again. This development is the result of both economic and demographic forces. By combining economic projections with demographic
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First NMR Experiments in the Hybrid, 40T and beyond: A challenge to traditional NMR instrumentation
Reyes, Arneil P.
2001-03-01
The recent commissioning of the continuous 45T hybrid magnet at NHMFL has opened new horizon for science but carried with it new challenges that forced NMR spectroscopists to reevaluate the traditional approach to NMR instrumentation. Very recently, a world record frequency at 1.5GHz has been achieved, signaling the new era of NMR probe designs that may someday blur the distinction between the classic NMR and millimeter-wave spectroscopies. No longer can we ignore stray capacitances and exposed leads in the terrain where every millimeter of cable counts. The challenge brought about by ever increasing fields and consequently, frequency, requirements has stimulated ingenuity among scientists. This is eased by accelerated growth in RF communications and computing technologies that made available advanced devices with more speed, power, bandwidth, noise immunity, flexibility, and complexity in small space at very low costs. Utilization of these devices have been paramount consideration in cutting-edge designs at NHMFL for Condensed Matter NMR and will be described in this talk. I will also discuss a number of first >33T NMR experiments to date utilizing the strength of the field to expose, as well as to induce occurrence of, new physical phenomena in condensed matter and which resulted in better understanding of the physics of materials. This work has been a result of continuing collaboration with P. L Kuhns, W. G. Moulton, W. P. Halperin (NU), and W. G. Clark (UCLA). The NHMFL is supported through the National Science Foundation and the State of Florida.
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NMR-based metabolomics in human disease diagnosis: Applications, limitations, and recommendations
Emwas, Abdul-Hamid M.
2013-04-03
Metabolomics is a dynamic and emerging research field, similar to proteomics, transcriptomics and genomics in affording global understanding of biological systems. It is particularly useful in functional genomic studies in which metabolism is thought to be perturbed. Metabolomics provides a snapshot of the metabolic dynamics that reflect the response of living systems to both pathophysiological stimuli and/or genetic modification. Because this approach makes possible the examination of interactions between an organism and its diet or environment, it is particularly useful for identifying biomarkers of disease processes that involve the environment. For example, the interaction of a high fat diet with cardiovascular disease can be studied via such a metabolomics approach by modeling the interaction between genes and diet. The high reproducibility of NMR-based techniques gives this method a number of advantages over other analytical techniques in large-scale and long-term metabolomic studies, such as epidemiological studies. This approach has been used to study a wide range of diseases, through the examination of biofluids, including blood plasma/serum, urine, blister fluid, saliva and semen, as well as tissue extracts and intact tissue biopsies. However, complicating the use of NMR spectroscopy in biomarker discovery is the fact that numerous variables can effect metabolic composition including, fasting, stress, drug administration, diet, gender, age, physical activity, life style and the subject\\'s health condition. To minimize the influence of these variations in the datasets, all experimental conditions including sample collection, storage, preparation as well as NMR spectroscopic parameters and data analysis should be optimized carefully and conducted in an identical manner as described by the local standard operating protocol. This review highlights the potential applications of NMR-based metabolomics studies and gives some recommendations to improve sample
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Bingol, Kerem; Brüschweiler, Rafael
2015-06-05
A novel metabolite identification strategy is presented for the combined NMR/MS analysis of complex metabolite mixtures. The approach first identifies metabolite candidates from 1D or 2D NMR spectra by NMR database query, which is followed by the determination of the masses (m/z) of their possible ions, adducts, fragments, and characteristic isotope distributions. The expected m/z ratios are then compared with the MS(1) spectrum for the direct assignment of those signals of the mass spectrum that contain information about the same metabolites as the NMR spectra. In this way, the mass spectrum can be assigned with very high confidence, and it provides at the same time validation of the NMR-derived metabolites. The method was first demonstrated on a model mixture, and it was then applied to human urine collected from a pool of healthy individuals. A number of metabolites could be detected that had not been reported previously, further extending the list of known urine metabolites. The new analysis approach, which is termed NMR/MS Translator, is fully automated and takes only a few seconds on a computer workstation. NMR/MS Translator synergistically uses the power of NMR and MS, enhancing the accuracy and efficiency of the identification of those metabolites compiled in databases.
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International Nuclear Information System (INIS)
Fukazawa, Nobuyuki
1990-01-01
Recently, attention has been paid to the various treatment of water and the utilization of water by magnetic treatment, electric field treatment and so on. It has been said that by these treatments, the change in the properties of water arises. The state of this treated water cannot be explained by the properties of water from conventional physical and chemical standpoints. In addition, the method of measurement of whether the change arose or not is not yet determined. It is necessary to establish the method of measurement for the basic state of water. In this study, O-17 NMR which observes the state of water directly at molecular or atomic level was investigated as the method of measuring water. The measurement of O-17 NMR was carried out with a JNR 90Q FT NMR of Fourier transformation type of JEOL Ltd. The experimental method and the results are reported. The result of measurement of the O-17 NMR spectrum for distilled ion exchange water is shown. It is know that it has very wide line width as compared with the NMR spectra of protons and C-13. The relative sensitivity of O-17 observation is about 1/100,000 of that of protons. As to the information on the state of water obtained by O-17 NMR, there are chemical shift and line width. As temperature rose, the line width showed decrease, which seemed to be related to the decrease of hydrogen combination. (K.I.)
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Solution NMR structure determination of proteins revisited
International Nuclear Information System (INIS)
Billeter, Martin; Wagner, Gerhard; Wuethrich, Kurt
2008-01-01
This 'Perspective' bears on the present state of protein structure determination by NMR in solution. The focus is on a comparison of the infrastructure available for NMR structure determination when compared to protein crystal structure determination by X-ray diffraction. The main conclusion emerges that the unique potential of NMR to generate high resolution data also on dynamics, interactions and conformational equilibria has contributed to a lack of standard procedures for structure determination which would be readily amenable to improved efficiency by automation. To spark renewed discussion on the topic of NMR structure determination of proteins, procedural steps with high potential for improvement are identified
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Value of NMR logging for heavy oil characterization
Energy Technology Data Exchange (ETDEWEB)
Chen, S.; Chen, J.; Georgi, D. [Baker Hughes, Calgary, AB (Canada); Sun, B. [Chevron Energy Technology Co., Calgary, AB (Canada)
2008-07-01
Non-conventional, heavy oil fields are becoming increasingly important to the security of energy supplies and are becoming economically profitable to produce. Heavy oil reservoirs are difficult to evaluate since they are typically shallow and the connate waters are very fresh. Other heavy oil reservoirs are oil-wet where the resistivities are not indicative of saturation. Nuclear magnetic resonance (NMR) detects molecular level interactions. As such, it responds distinctively to different hydrocarbon molecules, thereby opening a new avenue for constituent analysis. This feature makes NMR a more powerful technique than bulk oil density or viscosity measurements for characterizing oils, and is the basis for detecting gas in heavy oil fields. NMR logging, which measures fluid in pore space directly, is capable of separating oil from water. It is possible to discern movable from bound water by analyzing NMR logs. The oil viscosity can be also quantified from NMR logs, NMR relaxation time and diffusivity estimates. The unique challenges for heavy oil reservoir characterization for the NMR technique were discussed with reference to the extra-fast decay of the NMR signal in response to extra-heavy oil/tars, and the lack of sensitivity in measuring very slow diffusion of heavy oil molecules. This paper presented various methods for analyzing heavy oil reservoirs in different viscosity ranges. Heavy oil fields in Venezuela, Kazakhstan, Canada, Alaska and the Middle East were analyzed using different data interpretation approaches based on the reservoir formation characteristics and the heavy oil type. NMR direct fluid typing was adequate for clean sands and carbonate reservoirs while integrated approaches were used to interpret extra heavy oils and tars. It was concluded that NMR logs can provide quantitative measures for heavy oil saturation, identify sweet spots or tar streaks, and quantify heavy oil viscosity within reasonable accuracy. 14 refs., 16 figs.
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Investigation of zeolites by solid state quadrapole NMR
International Nuclear Information System (INIS)
Janssen, R.
1990-01-01
The subject of this thesis is the NMR investigation of zeolites. The nature and properties of zeolites are discussed. Some of the basic priniples of NMR techniques on quadrupole nuclei are presented. A special technique, namely a two-dimensional nutation experiment is discussed in detail. The theory of the nutation experiment for quadrupole spin species with spin quantum number 3/2 as well as 5/2 is presented. For both spin spcies the theoretical spectra are compared with experimental results. It is also shown that the nutation expeirment can be performed with several pulse schemes. It is shown how phase-sensitive pure-absorption nutation spectra can be obtained and an NMR-probe is presented that is capable of performing NMR experiments at high (up to 500 degree C) temperatures. The two-dimensional nutation NMR technique has been applied to sodium cations in zeolite NaA. For this purpose a numbre of zeolite samples were prepared that contained different amounts of water. With the aid of nutation NMR the hydration of the zeolite can be studied and conclusions can be drawn about the symmetry of the surrounding of the sodium cations. With the aid of an extension of the nutation NMR experiment: Rotary Echo Nutation NMR, it is shown that in zeolite NaA, in various stages of hydration, the sodium cations or water molecules are mobile. Proof is given by means of high-temperature 23 Na-NMR that dehydrates zeolite NaA undergoes a phase transition at ca. 120 degree C. In a high-temperature NMR investigation of zeolite ZSM-5 it is shown that the sodium ions start to execute motions when the temperature is increased. (author). 198 refs.; 72 figs.; 6 tabs
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NMR reaction monitoring in flow synthesis
Directory of Open Access Journals (Sweden)
M. Victoria Gomez
2017-02-01
Full Text Available Recent advances in the use of flow chemistry with in-line and on-line analysis by NMR are presented. The use of macro- and microreactors, coupled with standard and custom made NMR probes involving microcoils, incorporated into high resolution and benchtop NMR instruments is reviewed. Some recent selected applications have been collected, including synthetic applications, the determination of the kinetic and thermodynamic parameters and reaction optimization, even in single experiments and on the μL scale. Finally, software that allows automatic reaction monitoring and optimization is discussed.
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Petrophysical properties of greensand as predicted from NMR measurements
DEFF Research Database (Denmark)
Hossain, Zakir; Grattoni, Carlos A.; Solymar, Mikael
2011-01-01
ABSTRACT: Nuclear magnetic resonance (NMR) is a useful tool in reservoir evaluation. The objective of this study is to predict petrophysical properties from NMR T2 distributions. A series of laboratory experiments including core analysis, capillary pressure measurements, NMR T2 measurements...... with macro-pores. Permeability may be predicted from NMR by using Kozeny's equation when surface relaxivity is known. Capillary pressure drainage curves may be predicted from NMR T2 distribution when pore size distribution within a sample is homogeneous....
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International Nuclear Information System (INIS)
Avella, Eliseo; Fierro, Ricardo
2010-01-01
Based on an analysis of publications reported between 1972 and 2006, it became clear that there are inaccuracies in the limits of the ranges of integration that the authors assigned to signals in nuclear magnetic resonance (NMR) to the structural characterization of petroleum, coals and their derived fractions, from their hydrogen (1H NMR) and carbon (13C NMR) spectra. Consequently, consolidated limits were determined for the integration of 1H NMR spectra and 13C NMR of these samples using a statistical treatment applied to the limits of integration intervals already published. With these unified limits, correlation NMR charts were developed that are useful for the allocation of the integral at such intervals, and at smaller intervals defined in terms of the intersection between different assignments. Also raised equations needed to establish the integral attributable to specific fragments in an attempt to make a more accurate structural characterization from NMR spectra of oil, coal or fractions derived.
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Dynamics of solutions and fluid mixtures by NMR
International Nuclear Information System (INIS)
Delpuech, J.J.
1994-01-01
After a short introduction to NMR spectroscopy, with a special emphasis on dynamical aspects, an overview on two fundamental aspects of molecular dynamics, NMR relaxation and its relationship with molecular reorientation, and magnetization transfer phenomena induced by molecular rate processes (dynamic NMR) is presented, followed by specific mechanisms of relaxation encountered in paramagnetic systems or with quadrupolar nuclei. Application fields are then reviewed: solvent exchange on metal ions with a variable pressure NMR approach, applications of field gradients in NMR, aggregation phenomena and micro-heterogeneity in surfactant solutions, polymers and biopolymers in the liquid state, liquid-like molecules in rigid matrices and in soft matter (swollen polymers and gels, fluids in and on inorganic materials, food)
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New methods for the correction of 31P NMR spectra in in vivo NMR spectroscopy
International Nuclear Information System (INIS)
Starcuk, Z.; Bartusek, K.; Starcuk, Z. jr.
1994-01-01
The new methods for the correction of 31 P NMR spectra in vivo NMR spectroscopy have been performed. A method for the baseline correction of the spectra which represents a combination of time-domain and frequency-domain has been discussed.The method is very fast and efficient for minimization of base line artifacts of biological tissues impact
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NMR techniques in the study of cardiovascular structure and functions
International Nuclear Information System (INIS)
Osbakken, M.; Haselgrove, J.
1987-01-01
The chapter titles of this book are: Introduction to NMR Techniques;Theory of NMR Probe Design;Overview of Magnetic Resonance Imaging to Study the Cardiovascular System;Vascular Anatomy and Physiology Studied with NMR Techniques;Assessment of Myocardial Ischemia and Infarction by Nuclear Magnetic Resonance Imaging;The Use of MRI in Congenital Heart Disease;Cardiomyopathies and Myocarditis Studied with NMR Techniques;Determination of Myocardial Mechanical Function with Magnetic Resonance Imaging Techniques;Determination of Flow Using NMR Techniques;The Use of Contrast Agents in Cardiac MRI;Can Cardiovascular Disease Be Effectively Evaluated with NMR Spectroscopy? NMR Studies of ATP Synthesis Reactions in the Isolated Heart;Studies of Intermediary Metabolism in the Heart by 13C NMR Spectroscopy;23Na and 39K NMR Spectroscopic Studies of the Intact Beating Heart;and Evaluation of Skeletal Muscle Metabolism in Patients with Congestive Heart Failure Using Phosphorus Nuclear Magnetic Resonance
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13C-NMR assignment, structure, and dynamics of deoxyoligonucleotides
International Nuclear Information System (INIS)
Zanatta, N.; Borer, P.N.; Levy, G.C.
1986-01-01
The unique spectral properties of 13 C-NMR for studying nucleic acids and some of the important features of 13 C-NMR in oligonucleotide studies are demostrated. The main difficulty in studying oligonucleotides by 13 C-NMR and recent improvements in NMR instrumentation and advances in oligonucleotide synthesis are presented. The high resolution 13 C-NMR spectra, T 1 relaxation times and NOEs were measured for duplex of the self-complementary oligo-DNAs: d(CG) 3 and d(GGTATACC) are studied. The target of this study is to developed a systematic 13 C-NMR spectral assignment and to investigate the structure and dynamics of these two sequences by this techniques. (M.J.C.) [pt
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Energy Technology Data Exchange (ETDEWEB)
Ma, Z.R.; Zhang, P.Z.; Ding, G.L.; Li, L.Y.; Ye, C.H. [University of Science and Technology, Beijing (China). Dept. of Chemistry
1996-06-01
The permeation transportation and swelling behavior of solvents into coal are investigated by NMR imaging using pyridine-d{sub 5} and acetone-d{sub 6}. Images of coal swollen with deuterated solvents illuminate proton distributions of mobile phases within the coal macromolecular networks. More information about the chemical and physical structure of coal can be obtained using NMR imaging techniques.
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Energy Technology Data Exchange (ETDEWEB)
Engelbertz, A.
2006-07-01
In this thesis it is described how p-NMR can be applied to metals with verlo low hydrogen concentrations and how a combination of ultrasound and NMR can lead to an improvement of the measureing method. As examples measurements on H{sub 2}O and ethanol are described. (HSI)
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NMR investigation of coal extracts
Energy Technology Data Exchange (ETDEWEB)
Lang, I; Sebor, G [Ceskoslovenska Akademie Ved, Prague. Hornicky Ustav; Sebor, G Jr; Hajek, M; Mostecky, J [Vysoka Skola Chemicko-Technologicka, Prague (Czechoslovakia)
1978-07-01
Proton NMR spectroscopy was used for the evaluation of 10% coal extract solutions in deuterated pyridine. Four types of Czechoslovak coal were analyzed. Agreement was found between the aromaticity of coal extracts calculated from /sup 1/H NMR data using Brown's method and Ladner's and Williams' method and the characterization of an average molecule of the coal extract by the number of non-bridge carbon atoms of aromatic rings, by the overall number of aromatic ring carbon atoms and the number of aromatic rings, determined by the Williams and Ferris methods. The methods for calculating carbon distribution from /sup 1/H NMR data, however, contain some constants theoretically estimated or experimentally found using the method which still remain to be verified.
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NMR characteristics of low-grade glioma. Comparison with CT
Energy Technology Data Exchange (ETDEWEB)
Asato, Reinin; Tokuriki, Yasuhiko; Nakano, Yoshihisa; Itoh, Harumi; Torizuka, Kanji; Ueda, Tohru; Yamashita, Junkoh; Handa, Hajime
1985-08-01
Sixteen low-grade gliomas were evaluated both with nuclear magnetic resonance (NMR) imaging and with computed tomography (CT). In 13 cases (81%), the NMR images were much better in tissue contrast than the contrast-enhanced CT images. The tumors were shown as well-circumscribed oval lesions in the NMR, though they appeared as ill-defined, irregular, low-attenuation areas in the CT. The extent of the lesion, which was supposed to represent the active tumor tissue, was greater in the NMR than in the CT, because NMR tissue parameters (T/sub 1/, T/sub 2/) are more sensitive to pathological changes in brain tissue than is the X-ray attenuation coefficient. Though, in an optic glioma and a brain-stem astrocytoma, the CT with contrast enhancement displayed the contour of the mass as well as did NMR, it was inferior to the NMR in showing the cephalocaudal extension of the tumors. Calcification does not give a proton NMR signal under the present measuring conditions; thus the calcified cystic wall of a hypothalamic astrocytoma was displayed only in the CT images. In conclusion, the NMR imaging was apparently superior to contrast-enhanced CT in demonstrating the lesions due to low-grade glioma.
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Carbon-13 NMR spectroscopy of biological systems
Beckmann, Nicolau
1995-01-01
This book is intended to provide an in-depth understanding of 13C NMR as a tool in biological research. 13C NMR has provided unique information concerning complex biological systems, from proteins and nucleic acids to animals and humans. The subjects addressed include multidimensional heteronuclear techniques for structural studies of molecules in the liquid and solid states, the investigation of interactions in model membranes, the elucidation of metabolic pathwaysin vitro and in vivo on animals, and noninvasive metabolic studies performed on humans. The book is a unique mix of NMR methods and biological applications which makes it a convenient reference for those interested in research in this interdisciplinary area of physics, chemistry, biology, and medicine.Key Features* An interdisciplinary text with emphasis on both 13C NMR methodology and the relevant biological and biomedical issues* State-of-the-art 13C NMR techniques are described; Whenever possible, their advantages over other approaches are empha...
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NMR in the SPINE Structural Proteomics project.
Ab, E; Atkinson, A R; Banci, L; Bertini, I; Ciofi-Baffoni, S; Brunner, K; Diercks, T; Dötsch, V; Engelke, F; Folkers, G E; Griesinger, C; Gronwald, W; Günther, U; Habeck, M; de Jong, R N; Kalbitzer, H R; Kieffer, B; Leeflang, B R; Loss, S; Luchinat, C; Marquardsen, T; Moskau, D; Neidig, K P; Nilges, M; Piccioli, M; Pierattelli, R; Rieping, W; Schippmann, T; Schwalbe, H; Travé, G; Trenner, J; Wöhnert, J; Zweckstetter, M; Kaptein, R
2006-10-01
This paper describes the developments, role and contributions of the NMR spectroscopy groups in the Structural Proteomics In Europe (SPINE) consortium. Focusing on the development of high-throughput (HTP) pipelines for NMR structure determinations of proteins, all aspects from sample preparation, data acquisition, data processing, data analysis to structure determination have been improved with respect to sensitivity, automation, speed, robustness and validation. Specific highlights are protonless (13)C-direct detection methods and inferential structure determinations (ISD). In addition to technological improvements, these methods have been applied to deliver over 60 NMR structures of proteins, among which are five that failed to crystallize. The inclusion of NMR spectroscopy in structural proteomics pipelines improves the success rate for protein structure determinations.
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Direct 13C NMR Detection in HPLC Hyphenation Mode
DEFF Research Database (Denmark)
Wubshet, Sileshi Gizachew; Johansen, Kenneth; Nyberg, Nils
2012-01-01
Solid phase extraction (SPE) was introduced as a crucial step in the HPLC-SPE-NMR technique to enable online analyte enrichment from which proton-detected NMR experiments on submicrogram amounts from complex mixtures were possible. However, the significance of direct-detected (13)C NMR experiments...... application of HPLC-SPE-NMR analysis using direct-detected (13)C NMR spectra. HPLC column loading, accumulative SPE trappings, and the effect of different elution solvents were evaluated and optimized. A column loading of approximately 600 mug of a prefractionated triterpenoid mixture, six trappings...
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Peak globalization. Climate change, oil depletion and global trade
Energy Technology Data Exchange (ETDEWEB)
Curtis, Fred [Department of Economics, Drew University, Madison, NJ 07940 (United States)
2009-12-15
The global trade in goods depends upon reliable, inexpensive transportation of freight along complex and long-distance supply chains. Global warming and peak oil undermine globalization by their effects on both transportation costs and the reliable movement of freight. Countering the current geographic pattern of comparative advantage with higher transportation costs, climate change and peak oil will thus result in peak globalization, after which the volume of exports will decline as measured by ton-miles of freight. Policies designed to mitigate climate change and peak oil are very unlikely to change this result due to their late implementation, contradictory effects and insufficient magnitude. The implication is that supply chains will become shorter for most products and that production of goods will be located closer to where they are consumed. (author)
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Peak globalization. Climate change, oil depletion and global trade
International Nuclear Information System (INIS)
Curtis, Fred
2009-01-01
The global trade in goods depends upon reliable, inexpensive transportation of freight along complex and long-distance supply chains. Global warming and peak oil undermine globalization by their effects on both transportation costs and the reliable movement of freight. Countering the current geographic pattern of comparative advantage with higher transportation costs, climate change and peak oil will thus result in peak globalization, after which the volume of exports will decline as measured by ton-miles of freight. Policies designed to mitigate climate change and peak oil are very unlikely to change this result due to their late implementation, contradictory effects and insufficient magnitude. The implication is that supply chains will become shorter for most products and that production of goods will be located closer to where they are consumed. (author)
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ECG gated NMR-CT for cardiovascular diseases
International Nuclear Information System (INIS)
Nishikawa, J.; Machida, K.; Iio, M.; Yoshimoto, N.; Sugimoto, T.; Kawaguchi, H.; Mano, H.
1984-01-01
The authors applied NMR-CT to cardiac study with ECG gated technique to evaluate the left ventricular (LV) function and compared it with cardiovascular nuclear medicine study (NM). The NMR-CT machine has resistive air-core magnet with 0.15 Tesla. The saturation recovery image or inversion recovery image were obtained as 256 x 256 matrix and 15 mm in thickness. The study population was ten patients who were evaluated both by NMR image and by NM performed within one week interval. The heart muscle was able to be visualized without any contrast material nor radioisotopes in inversion recovery images, whereas saturation recovery images failed to separate heart muscle from blood pool. The wall motions of LV in both methods were well correlated except for inferior wall. The values of ejection fraction in NMR image were moderately low, but two modalities showed satisfactory correlation (r=0.85). The region of myocardial infarction was revealed as wall thinning and/or wall motion abnormality. It is still preliminary to draw a conclusion, however, it can be said that in the evaluation of LV function, method by NMR might be of equal value to those of NM. It can be certain that eventually gated NMR-CT will become more effective method for various aspects of cardiovascular evaluation
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Structural investigations of substituted indolizine derivatives by NMR studies
International Nuclear Information System (INIS)
Furdui, Bianca; Dinica, Rodica; Demeunynck, Martine; Druta, Ioan
2008-01-01
Owing to the increasing importance of indolizine heterocycles in the field of biology and pharmacology we have synthesized and investigated the obtained heterocycles by NMR techniques. In order to investigate the substituent effects on the spectroscopic properties, a series of indolizine derivatives were studied by 1 H-NMR, 13 C-NMR and 2D NMR (GCOSY, GHMBC and GHMQC spectra). (authors)
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International Nuclear Information System (INIS)
Ueda, K.; Kohara, T.; Yamada, Y.
1995-01-01
La and Pb NMR signals were observed in LaPb 2 with a superconducting transition temperature of about 7 K. The width of the Pb NMR spectrum with an asymmetric line shape was rather narrower than those of Er-, Gd- and Ho-Pb 2 . The spin-lattice relaxation time of Pb nuclei was twice longer than that of Pb metal. La NMR spectrum had satellites due to the electric quadrupole interaction. These results show that each local environment at La or Pb site in LaPb 2 compound is uniquely determined, compared with those in randomly substituted alloys. ((orig.))
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Nuclear magnetic resonance (NMR) tomography
International Nuclear Information System (INIS)
Skalpe, I.O.
1984-01-01
A brief survey of the working principle of the NMR technique in diagnostical medicine is given. Its clinical usefulness for locating tumors, diagnosing various other diseases, such as some mental illnesses and multiple sclerosis, and its possibilities for studying biochemical processes in vivo are mentioned. The price of NMR image scanners and the problems of the strong magnetic field around the machines are mentioned
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Brain atrophy during aging. Quantitative studies with X-CT and NMR-CT
Energy Technology Data Exchange (ETDEWEB)
Matsuzawa, Taiju; Yamada, Kenji; Yamada, Susumu; Ono, Shuichi; Takeda, Shunpei; Hatazawa, Jun; Ito, Masatoshi; Kubota, Kazuo
1985-12-01
Age-related brain atrophy was investigated in thousands of persons with no neurologic disturbances using X-CT and NMR-CT. Brain atrophy was minimal in 34-35 years old in both sexes, increased exponentially to the increasing age after 34-35 years, and probably resulted in dementia, such as vascular or multi-infarct dementia. Brain atrophy was significantly greater in men than in women at all ages. Brain volumes were maximal in 34-35 years old in both sexes with minimal individual differences which increased proportionally to the increasing age. Remarkable individual differences in the extent of brain atrophy (20 - 30 %) existed among aged subjects. Progression of brain atrophy was closely related to loss of mental activities independently of their ages. Our longitudinal study has revealed that the most important factors promoting brain atrophy during aging was the decrease in the cerebral blood flow. We have classified brain atrophy into sulcal and cisternal enlargement type (type I), ventricular enlargement type (type II) and mixed type (type III) according to the clinical study using NMR-CT. Brain atrophy of type I progresses significantly in almost all of the geriatric disorders. This type of brain atrophy progresses significantly in heavy smokers and drinkers. Therefore this type of brain atrophy might be caused by the decline in the blood flow in anterior and middle cerebral arteries. Brain atrophy of type II was caused by the disturbance of cerebrospinal fluid circulation after cerebral bleeding and subarachnoid bleeding. Brain atrophy of type III was seen in vascular dementia or multi-infarct dementia which was caused by loss of brain matter after multiple infarction, and was seen also in dementia of Alzheimer type in which degeneration of nerve cells results in brain atrophy. NMR-CT can easily detect small infarction (lacunae) and edematous lesions resulting from ischemia and hypertensive encephalopathy. (J.P.N.).
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Decline traffic information system
Energy Technology Data Exchange (ETDEWEB)
Du Plessis, K [Computer Sciences Corporation (CSC), Sydney (Australia)
2007-09-06
BHP Billion (BHPB) Cannington has experienced problems in regards to their traffic flow in the decline at the mine. The problems related to reports on near misses of vehicles moving towards each other in the decline. The decline is also to narrow for trucks to pass each other and the operators need to be aware of oncoming traffic in the decline to ensure they could take early evasive steps to ensure the rules of right of way in the decline are adhered to. BHPB Cannington requested CSC to conduct a problem analysis and to provide a solutions proposal to Cannington. The solution was put forward as an augmentation of their current safety procedures used with in the decline. During this phase of the project CSC developed a solutions architecture which involved the use of Active (Radio Frequency Identification) RFID tagging which will enable vehicle movement tracking on a real time basis after which the appropriate traffic movement can be relayed to the operators in the decline. The primary objective of the DTIS is to provide accurate information of traffic movement in the decline and present that information to the operators of the decline IN THE DECLINE upon which they would make their decisions. (orig.)
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Sustained climate warming drives declining marine biological productivity
Moore, J. Keith; Fu, Weiwei; Primeau, Francois; Britten, Gregory L.; Lindsay, Keith; Long, Matthew; Doney, Scott C.; Mahowald, Natalie; Hoffman, Forrest; Randerson, James T.
2018-03-01
Climate change projections to the year 2100 may miss physical-biogeochemical feedbacks that emerge later from the cumulative effects of climate warming. In a coupled climate simulation to the year 2300, the westerly winds strengthen and shift poleward, surface waters warm, and sea ice disappears, leading to intense nutrient trapping in the Southern Ocean. The trapping drives a global-scale nutrient redistribution, with net transfer to the deep ocean. Ensuing surface nutrient reductions north of 30°S drive steady declines in primary production and carbon export (decreases of 24 and 41%, respectively, by 2300). Potential fishery yields, constrained by lower–trophic-level productivity, decrease by more than 20% globally and by nearly 60% in the North Atlantic. Continued high levels of greenhouse gas emissions could suppress marine biological productivity for a millennium.
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Bayesian Peak Picking for NMR Spectra
Cheng, Yichen
2014-02-01
Protein structure determination is a very important topic in structural genomics, which helps people to understand varieties of biological functions such as protein-protein interactions, protein–DNA interactions and so on. Nowadays, nuclear magnetic resonance (NMR) has often been used to determine the three-dimensional structures of protein in vivo. This study aims to automate the peak picking step, the most important and tricky step in NMR structure determination. We propose to model the NMR spectrum by a mixture of bivariate Gaussian densities and use the stochastic approximation Monte Carlo algorithm as the computational tool to solve the problem. Under the Bayesian framework, the peak picking problem is casted as a variable selection problem. The proposed method can automatically distinguish true peaks from false ones without preprocessing the data. To the best of our knowledge, this is the first effort in the literature that tackles the peak picking problem for NMR spectrum data using Bayesian method.
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NMR imaging of the cardiovascular system
International Nuclear Information System (INIS)
Canby, R.C.; Evanochko, W.T.; Pohost, G.M.
1986-01-01
Proton nuclear magnetic resonance (NMR) imaging permits high-resolution tomographic and three-dimensional images of the human body to be obtained without exposure to ionizing radiation. Such imaging not only yields anatomic resolution comparable to X-ray examinations but also provides a potential means to discriminate between healthy tissue and diseased tissue. This potential is based on certain NMR properties known as relaxation times, which determine, in part, the signal intensity in an image. These properties are related to such factors as the sizes and concentrations of proteins and mobile lipids and the compartmentalization of the protons of water. Although NMR imaging (also called magnetic resonance imaging, MRI) is becoming widely available for clinical use, application to the cardiovascular system, though promising, remains primarily a research tool. Gated proton NMR imaging can generate cardiac images with excellent morphologic detail and contrast; however, its ultimate importance as a cardiovascular diagnostic modality will depend on the development of several unique applications. These applications are discussed in this paper
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Mango Sudden Decline (MSD), sometimes referred to as mango wilt, is an important disease of mango caused by one of the most significant fungal species causing disease in woody plants, Ceratocystis fimbriata. This species is mainly disseminated by the mango bark beetle, Hypocryphalus mangiferae (Steb...
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Jézéquel, Tangi; Silvestre, Virginie; Dinis, Katy; Giraudeau, Patrick; Akoka, Serge
2018-04-01
Isotope ratio monitoring by 13C NMR spectrometry (irm-13C NMR) provides the complete 13C intramolecular position-specific composition at natural abundance. It represents a powerful tool to track the (bio)chemical pathway which has led to the synthesis of targeted molecules, since it allows Position-specific Isotope Analysis (PSIA). Due to the very small composition range (which represents the range of variation of the isotopic composition of a given nuclei) of 13C natural abundance values (50‰), irm-13C NMR requires a 1‰ accuracy and thus highly quantitative analysis by 13C NMR. Until now, the conventional strategy to determine the position-specific abundance xi relies on the combination of irm-MS (isotopic ratio monitoring Mass Spectrometry) and 13C quantitative NMR. However this approach presents a serious drawback since it relies on two different techniques and requires to measure separately the signal of all the carbons of the analyzed compound, which is not always possible. To circumvent this constraint, we recently proposed a new methodology to perform 13C isotopic analysis using an internal reference method and relying on NMR only. The method combines a highly quantitative 1H NMR pulse sequence (named DWET) with a 13C isotopic NMR measurement. However, the recently published DWET sequence is unsuited for samples with short T1, which forms a serious limitation for irm-13C NMR experiments where a relaxing agent is added. In this context, we suggest two variants of the DWET called Multi-WET and Profiled-WET, developed and optimized to reach the same accuracy of 1‰ with a better immunity towards T1 variations. Their performance is evaluated on the determination of the 13C isotopic profile of vanillin. Both pulse sequences show a 1‰ accuracy with an increased robustness to pulse miscalibrations compared to the initial DWET method. This constitutes a major advance in the context of irm-13C NMR since it is now possible to perform isotopic analysis with high
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Contact replacement for NMR resonance assignment.
Xiong, Fei; Pandurangan, Gopal; Bailey-Kellogg, Chris
2008-07-01
Complementing its traditional role in structural studies of proteins, nuclear magnetic resonance (NMR) spectroscopy is playing an increasingly important role in functional studies. NMR dynamics experiments characterize motions involved in target recognition, ligand binding, etc., while NMR chemical shift perturbation experiments identify and localize protein-protein and protein-ligand interactions. The key bottleneck in these studies is to determine the backbone resonance assignment, which allows spectral peaks to be mapped to specific atoms. This article develops a novel approach to address that bottleneck, exploiting an available X-ray structure or homology model to assign the entire backbone from a set of relatively fast and cheap NMR experiments. We formulate contact replacement for resonance assignment as the problem of computing correspondences between a contact graph representing the structure and an NMR graph representing the data; the NMR graph is a significantly corrupted, ambiguous version of the contact graph. We first show that by combining connectivity and amino acid type information, and exploiting the random structure of the noise, one can provably determine unique correspondences in polynomial time with high probability, even in the presence of significant noise (a constant number of noisy edges per vertex). We then detail an efficient randomized algorithm and show that, over a variety of experimental and synthetic datasets, it is robust to typical levels of structural variation (1-2 AA), noise (250-600%) and missings (10-40%). Our algorithm achieves very good overall assignment accuracy, above 80% in alpha-helices, 70% in beta-sheets and 60% in loop regions. Our contact replacement algorithm is implemented in platform-independent Python code. The software can be freely obtained for academic use by request from the authors.
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NMR characterization of thin films
Gerald II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela
2010-06-15
A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.
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NMR characterization of thin films
Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela
2008-11-25
A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.
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Software Library for Bruker TopSpin NMR Data Files
Energy Technology Data Exchange (ETDEWEB)
2016-10-14
A software library for parsing and manipulating frequency-domain data files that have been processed using the Bruker TopSpin NMR software package. In the context of NMR, the term "processed" indicates that the end-user of the Bruker TopSpin NMR software package has (a) Fourier transformed the raw, time-domain data (the Free Induction Decay) into the frequency-domain and (b) has extracted the list of NMR peaks.
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Polymeric proanthocyanidins 13C NMR studies of procyanidins
Lawrence J. Porter; Roger H. Newman; Lai Yeap Foo; Herbert Wong; Richard W. Hemingway
1982-01-01
Proanthocyanidin polymers have been shown to consist entirely of flavan-3-ol units by a combination of techniques including 13C n.m.r. spectroscopy. The 13C n.m.r. spectra of the polymers and related molecules are now considered in more detail. Prior to this study UC n.m.r. data has been published of procyanidins and...
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Flow units from integrated WFT and NMR data
Energy Technology Data Exchange (ETDEWEB)
Kasap, E.; Altunbay, M.; Georgi, D.
1997-08-01
Reliable and continuous permeability profiles are vital as both hard and soft data required for delineating reservoir architecture. They can improve the vertical resolution of seismic data, well-to-well stratigraphic correlations, and kriging between the well locations. In conditional simulations, permeability profiles are imposed as the conditioning data. Variograms, covariance functions and other geostatistical indicators are more reliable when based on good quality permeability data. Nuclear Magnetic Resonance (NMR) logging and Wireline Formation Tests (WFT) separately generate a wealth of information, and their synthesis extends the value of this information further by providing continuous and accurate permeability profiles without increasing the cost. NMR and WFT data present a unique combination because WFTs provide discrete, in situ permeability based on fluid-flow, whilst NMR responds to the fluids in the pore space and yields effective porosity, pore-size distribution, bound and moveable fluid saturations, and permeability. The NMR permeability is derived from the T{sub 2}-distribution data. Several equations have been proposed to transform T{sub 2} data to permeability. Regardless of the transform model used, the NMR-derived permeabilities depend on interpretation parameters that may be rock specific. The objective of this study is to integrate WFT permeabilities with NMR-derived, T{sub 2} distribution-based permeabilities and thereby arrive at core quality, continuously measured permeability profiles. We outlined the procedures to integrate NMR and WFT data and applied the procedure to a field case. Finally, this study advocates the use of hydraulic unit concepts to extend the WFT-NMR derived, core quality permeabilities to uncored intervals or uncored wells.
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The demography of words: The global decline in non-numeric fertility preferences, 1993-2011.
Frye, Margaret; Bachan, Lauren
2017-07-01
This paper examines the decline in non-numeric responses to questions about fertility preferences among women in the developing world. These types of response-such as 'don't know' or 'it's up to God'-have often been interpreted through the lens of fertility transition theory as an indication that reproduction has not yet entered women's 'calculus of conscious choice'. However, this has yet to be investigated cross-nationally and over time. Using 19 years of data from 32 countries, we find that non-numeric fertility preferences decline most substantially in the early stages of a country's fertility transition. Using country-specific and multilevel models, we explore the individual- and contextual-level characteristics associated with women's likelihood of providing a non-numeric response to questions about their fertility preferences. Non-numeric fertility preferences are influenced by a host of social factors, with educational attainment and knowledge of contraception being the most robust and consistent predictors.
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A microscale protein NMR sample screening pipeline
Energy Technology Data Exchange (ETDEWEB)
Rossi, Paolo; Swapna, G. V. T.; Huang, Yuanpeng J.; Aramini, James M. [State University of New Jersey, Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers (United States); Anklin, Clemens [Bruker Biospin Corporation (United States); Conover, Kenith; Hamilton, Keith; Xiao, Rong; Acton, Thomas B.; Ertekin, Asli; Everett, John K.; Montelione, Gaetano T., E-mail: guy@cabm.rutgers.ed [State University of New Jersey, Center for Advanced Biotechnology and Medicine, Department of Molecular Biology and Biochemistry, Rutgers (United States)
2010-01-15
As part of efforts to develop improved methods for NMR protein sample preparation and structure determination, the Northeast Structural Genomics Consortium (NESG) has implemented an NMR screening pipeline for protein target selection, construct optimization, and buffer optimization, incorporating efficient microscale NMR screening of proteins using a micro-cryoprobe. The process is feasible because the newest generation probe requires only small amounts of protein, typically 30-200 {mu}g in 8-35 {mu}l volume. Extensive automation has been made possible by the combination of database tools, mechanization of key process steps, and the use of a micro-cryoprobe that gives excellent data while requiring little optimization and manual setup. In this perspective, we describe the overall process used by the NESG for screening NMR samples as part of a sample optimization process, assessing optimal construct design and solution conditions, as well as for determining protein rotational correlation times in order to assess protein oligomerization states. Database infrastructure has been developed to allow for flexible implementation of new screening protocols and harvesting of the resulting output. The NESG micro NMR screening pipeline has also been used for detergent screening of membrane proteins. Descriptions of the individual steps in the NESG NMR sample design, production, and screening pipeline are presented in the format of a standard operating procedure.
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Characterization of natural bentonite by NMR
International Nuclear Information System (INIS)
Leite, Sidnei Q.M.; Dieguez, Lidia C.; Menezes, Sonia M.C.; San Gil, Rosane A.S.
1993-01-01
Solid state NMR as well as several other instrumental chemical analysis techniques were used in order to characterize two natural occurring bentonite. The methodology is described. The NMR spectra, together with the other used techniques suggest that the observed differences are due to iron inclusions in tetrahedral and octahedral sites
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Selective sensitivity enhancement in FT-NMR
International Nuclear Information System (INIS)
Farrar, T.C.
1987-01-01
In this article the basic two-spin nuclear magnetic resonance (NMR) experiment and the new sensitivity enhancement experiments are reviewed. In part two of this two-part series an overview of two-dimensional NMR experiments will be presented. Part two will appear in the June 1 issue of Analytical Chemistry
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NMR-Fragment Based Virtual Screening: A Brief Overview.
Singh, Meenakshi; Tam, Benjamin; Akabayov, Barak
2018-01-25
Fragment-based drug discovery (FBDD) using NMR has become a central approach over the last twenty years for development of small molecule inhibitors against biological macromolecules, to control a variety of cellular processes. Yet, several considerations should be taken into account for obtaining a therapeutically relevant agent. In this review, we aim to list the considerations that make NMR fragment screening a successful process for yielding potent inhibitors. Factors that may govern the competence of NMR in fragment based drug discovery are discussed, as well as later steps that involve optimization of hits obtained by NMR-FBDD.
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NMR-Fragment Based Virtual Screening: A Brief Overview
Directory of Open Access Journals (Sweden)
Meenakshi Singh
2018-01-01
Full Text Available Fragment-based drug discovery (FBDD using NMR has become a central approach over the last twenty years for development of small molecule inhibitors against biological macromolecules, to control a variety of cellular processes. Yet, several considerations should be taken into account for obtaining a therapeutically relevant agent. In this review, we aim to list the considerations that make NMR fragment screening a successful process for yielding potent inhibitors. Factors that may govern the competence of NMR in fragment based drug discovery are discussed, as well as later steps that involve optimization of hits obtained by NMR-FBDD.
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IR and NMR spectroscopic correlation of enterobactin by DFT
Moreno, M.; Zacarias, A.; Porzel, A.; Velasquez, L.; Gonzalez, G.; Alegría-Arcos, M.; Gonzalez-Nilo, F.; Gross, E. K. U.
2018-06-01
Emerging and re-emerging epidemic diseases pose an ongoing threat to global health. Currently, Enterobactin and Enterobactin derivatives have gained interest, owing to their potential application in the pharmaceutical field. As it is known [J. Am. Chem. Soc (1979) 101, 20, 6097-6104], Enterobactin (H6EB) is an efficient iron carrier synthesized and secreted by many microbial species. In order to facilitate the elucidation of enterobactin and its analogues, here we propose the creation of a H6EB standard set using Density Functional Theory Infrared (IR) and NMR spectra. We used two exchange-correlation (xc) functionals (PBE including long-range corrections sbnd LC-PBEsbnd and mPW1), 2 basis sets (QZVP and 6-31G(d)) and 2 grids (fine and ultrafine) for most of the H6EB structures dependent of dihedral angles. The results show a significant difference between the Osbnd H and Nsbnd H bands, while the Cdbnd O amide and Osbnd (Cdbnd O)sbnd IR bands are often found on top of each other. The NMR DFT calculations show a strong dependence on the xc functional, basis set, and grid used for the H6EB structure. Calculated 1H and 13C NMR spectra enable the effect of the solvent to be understood in the context of the experimental measurements. The good agreement between the experimental and the calculated spectra using LC-PBE/QZVP and ultrafine grid suggest the possibility of the systems reported here to be considered as a standard set. The dependence of electrostatic potential and frontier orbitals with the catecholamide dihedral angles of H6EB is described. The matrix-assisted laser desorption/ionization time of the flight mass spectrometry (MALDI-TOF MS) of H6EB is also reported of manner to enrich the knowledge about its reactivity.
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Fluid-Rock Characterization and Interactions in NMR Well Logging
Energy Technology Data Exchange (ETDEWEB)
George J. Hirasaki; Kishore K. Mohanty
2005-09-05
The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.
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Konuma, Tsuyoshi; Harada, Erisa; Sugase, Kenji
2015-12-01
Protein dynamics plays important roles in many biological events, such as ligand binding and enzyme reactions. NMR is mostly used for investigating such protein dynamics in a site-specific manner. Recently, NMR has been actively applied to large proteins and intrinsically disordered proteins, which are attractive research targets. However, signal overlap, which is often observed for such proteins, hampers accurate analysis of NMR data. In this study, we have developed a new methodology called relaxation dispersion difference that can extract conformational exchange parameters from overlapped NMR signals measured using relaxation dispersion spectroscopy. In relaxation dispersion measurements, the signal intensities of fluctuating residues vary according to the Carr-Purcell-Meiboon-Gill pulsing interval, whereas those of non-fluctuating residues are constant. Therefore, subtraction of each relaxation dispersion spectrum from that with the highest signal intensities, measured at the shortest pulsing interval, leaves only the signals of the fluctuating residues. This is the principle of the relaxation dispersion difference method. This new method enabled us to extract exchange parameters from overlapped signals of heme oxygenase-1, which is a relatively large protein. The results indicate that the structural flexibility of a kink in the heme-binding site is important for efficient heme binding. Relaxation dispersion difference requires neither selectively labeled samples nor modification of pulse programs; thus it will have wide applications in protein dynamics analysis.
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Energy Technology Data Exchange (ETDEWEB)
Konuma, Tsuyoshi [Icahn School of Medicine at Mount Sinai, Department of Structural and Chemical Biology (United States); Harada, Erisa [Suntory Foundation for Life Sciences, Bioorganic Research Institute (Japan); Sugase, Kenji, E-mail: sugase@sunbor.or.jp, E-mail: sugase@moleng.kyoto-u.ac.jp [Kyoto University, Department of Molecular Engineering, Graduate School of Engineering (Japan)
2015-12-15
Protein dynamics plays important roles in many biological events, such as ligand binding and enzyme reactions. NMR is mostly used for investigating such protein dynamics in a site-specific manner. Recently, NMR has been actively applied to large proteins and intrinsically disordered proteins, which are attractive research targets. However, signal overlap, which is often observed for such proteins, hampers accurate analysis of NMR data. In this study, we have developed a new methodology called relaxation dispersion difference that can extract conformational exchange parameters from overlapped NMR signals measured using relaxation dispersion spectroscopy. In relaxation dispersion measurements, the signal intensities of fluctuating residues vary according to the Carr-Purcell-Meiboon-Gill pulsing interval, whereas those of non-fluctuating residues are constant. Therefore, subtraction of each relaxation dispersion spectrum from that with the highest signal intensities, measured at the shortest pulsing interval, leaves only the signals of the fluctuating residues. This is the principle of the relaxation dispersion difference method. This new method enabled us to extract exchange parameters from overlapped signals of heme oxygenase-1, which is a relatively large protein. The results indicate that the structural flexibility of a kink in the heme-binding site is important for efficient heme binding. Relaxation dispersion difference requires neither selectively labeled samples nor modification of pulse programs; thus it will have wide applications in protein dynamics analysis.
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NMR investigations of molecular dynamics
Palmer, Arthur
2011-03-01
NMR spectroscopy is a powerful experimental approach for characterizing protein conformational dynamics on multiple time scales. The insights obtained from NMR studies are complemented and by molecular dynamics (MD) simulations, which provide full atomistic details of protein dynamics. Homologous mesophilic (E. coli) and thermophilic (T. thermophilus) ribonuclease H (RNase H) enzymes serve to illustrate how changes in protein sequence and structure that affect conformational dynamic processes can be monitored and characterized by joint analysis of NMR spectroscopy and MD simulations. A Gly residue inserted within a putative hinge between helices B and C is conserved among thermophilic RNases H, but absent in mesophilic RNases H. Experimental spin relaxation measurements show that the dynamic properties of T. thermophilus RNase H are recapitulated in E. coli RNase H by insertion of a Gly residue between helices B and C. Additional specific intramolecular interactions that modulate backbone and sidechain dynamical properties of the Gly-rich loop and of the conserved Trp residue flanking the Gly insertion site have been identified using MD simulations and subsequently confirmed by NMR spin relaxation measurements. These results emphasize the importance of hydrogen bonds and local steric interactions in restricting conformational fluctuations, and the absence of such interactions in allowing conformational adaptation to substrate binding.
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Straightforward and complete deposition of NMR data to the PDBe
International Nuclear Information System (INIS)
Penkett, Christopher J.; Ginkel, Glen van; Velankar, Sameer; Swaminathan, Jawahar; Ulrich, Eldon L.; Mading, Steve; Stevens, Tim J.; Fogh, Rasmus H.; Gutmanas, Aleksandras; Kleywegt, Gerard J.; Henrick, Kim; Vranken, Wim F.
2010-01-01
We present a suite of software for the complete and easy deposition of NMR data to the PDB and BMRB. This suite uses the CCPN framework and introduces a freely downloadable, graphical desktop application called CcpNmr Entry Completion Interface (ECI) for the secure editing of experimental information and associated datasets through the lifetime of an NMR project. CCPN projects can be created within the CcpNmr Analysis software or by importing existing NMR data files using the CcpNmr FormatConverter. After further data entry and checking with the ECI, the project can then be rapidly deposited to the PDBe using AutoDep, or exported as a complete deposition NMR-STAR file. In full CCPN projects created with ECI, it is straightforward to select chemical shift lists, restraint data sets, structural ensembles and all relevant associated experimental collection details, which all are or will become mandatory when depositing to the PDB. Instructions and download information for the ECI are available from the PDBe web site at http://www.ebi.ac.uk/pdbe/nmr/deposition/eci.htmlhttp://www.ebi.ac.uk/pdbe/nmr/deposition/eci.html.
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DEFF Research Database (Denmark)
Niño-Zarazúa, Miguel; Roope, Laurence; Tarp, Finn
2017-01-01
This paper measures trends in global interpersonal inequality during 1975–2010 using data from the most recent version of the World Income Inequality Database (WIID). The picture that emerges using ‘absolute,’ and even ‘centrist’ measures of inequality, is very different from the results obtained...... by centrist measures such as the Krtscha, could return to 1975 levels, at today's domestic and global per capita income levels, but this would require quite dramatic structural reforms to reduce domestic inequality levels in most countries....... using standard ‘relative’ inequality measures such as the Gini coefficient or Coefficient of Variation. Relative global inequality has declined substantially over the decades. In contrast, ‘absolute’ inequality, as captured by the Standard Deviation and Absolute Gini, has increased considerably...
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(S)Pinning down protein interactions by NMR
DEFF Research Database (Denmark)
Teilum, Kaare; Kunze, Micha Ben Achim; Erlendsson, Simon
2017-01-01
Protein molecules are highly diverse communication platforms and their interaction repertoire stretches from atoms over small molecules such as sugars and lipids to macromolecules. An important route to understanding molecular communication is to quantitatively describe their interactions...... all types of protein reactions, which can span orders of magnitudes in affinities, reaction rates and lifetimes of states. As the more versatile technique, solution NMR spectroscopy offers a remarkable catalogue of methods that can be successfully applied to the quantitative as well as qualitative...... descriptions of protein interactions. In this review we provide an easy-access approach to NMR for the non-NMR specialist and describe how and when solution state NMR spectroscopy is the method of choice for addressing protein ligand interaction. We describe very briefly the theoretical background...
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Perez, Manuel
2017-01-01
The automatic analysis of NMR data has been a much-desired endeavour for the last six decades, as it is the case with any other analytical technique. This need for automation has only grown as advances in hardware; pulse sequences and automation have opened new research areas to NMR and increased the throughput of data. Full automatic analysis is a worthy, albeit hard, challenge, but in a world of artificial intelligence, instant communication and big data, it seems that this particular fight is happening with only one technique at a time (let this be NMR, MS, IR, UV or any other), when the reality of most laboratories is that there are several types of analytical instrumentation present. Data aggregation, verification and elucidation by using complementary techniques (e.g. MS and NMR) is a desirable outcome to pursue, although a time-consuming one if performed manually; hence, the use of automation to perform the heavy lifting for users is required to make the approach attractive for scientists. Many of the decisions and workflows that could be implemented under automation will depend on the two-way communication with databases that understand analytical data, because it is desirable not only to query these databases but also to grow them in as much of an automatic manner as possible. How these databases are designed, set up and the data inside classified will determine what workflows can be implemented. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.
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Dispositional Optimism and Terminal Decline in Global Quality of Life
Zaslavsky, Oleg; Palgi, Yuval; Rillamas-Sun, Eileen; LaCroix, Andrea Z.; Schnall, Eliezer; Woods, Nancy F.; Cochrane, Barbara B.; Garcia, Lorena; Hingle, Melanie; Post, Stephen; Seguin, Rebecca; Tindle, Hilary; Shrira, Amit
2015-01-01
We examined whether dispositional optimism relates to change in global quality of life (QOL) as a function of either chronological age or years to impending death. We used a sample of 2,096 deceased postmenopausal women from the Women's Health Initiative clinical trials who were enrolled in the 2005-2010 Extension Study and for whom at least 1…
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Erich, Sarah; Schill, Sandra; Annweiler, Eva; Waiblinger, Hans-Ulrich; Kuballa, Thomas; Lachenmeier, Dirk W; Monakhova, Yulia B
2015-12-01
The increased sales of organically produced food create a strong need for analytical methods, which could authenticate organic and conventional products. Combined chemometric analysis of (1)H NMR-, (13)C NMR-spectroscopy data, stable-isotope data (IRMS) and α-linolenic acid content (gas chromatography) was used to differentiate organic and conventional milk. In total 85 raw, pasteurized and ultra-heat treated (UHT) milk samples (52 organic and 33 conventional) were collected between August 2013 and May 2014. The carbon isotope ratios of milk protein and milk fat as well as the α-linolenic acid content of these samples were determined. Additionally, the milk fat was analyzed by (1)H and (13)C NMR spectroscopy. The chemometric analysis of combined data (IRMS, GC, NMR) resulted in more precise authentication of German raw and retail milk with a considerably increased classification rate of 95% compared to 81% for NMR and 90% for IRMS using linear discriminate analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.
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2D NMR studies of biomolecules
International Nuclear Information System (INIS)
Lamerichs, R.M.J.N.
1989-01-01
The work described in this thesis comprises two related subjects. The first part describes methods to derive high-resolution structures of proteins in solution using two-dimensional (2-D) NMR. The second part describes 2-D NMR studies on the interaction between proteins and DNA. (author). 261 refs.; 52 figs.; 23 tabs
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Summers, Ron W.; Foster, Simon; Swann, Bob; Etheridge, Brian
2012-05-01
Declines in numbers by several wader species in Britain have been linked to climate change, but the mechanism for the declines has rarely been explored. Britain lies at the northern end of the East Atlantic Flyway, and supports 1.3 million out of the Flyway's 8.5 million coastal waders (Charadrii) in winter and the Purple Sandpiper is one of the species whose numbers have declined. Here, we examine the dynamics of the decline as observed in the Moray Firth, northeast Scotland, investigating whether the decline was due to poorer apparent survival (return rate) or poorer recruitment of young birds. The maximum number in the Moray Firth declined from 860 in 1987/88 to 236 in 2006/07, with some increase during winters 2007/08 and 2008/09. At the three main high-tide roosts (Balintore, Lossiemouth and Buckie) the maximum combined number declined from 574 to 90. Changes in survival and recruitment (percentage of first-year birds) were examined at these roosts from captured samples, which were ringed and recaptured. There were no significant changes between winters in survival rates, nor were there differences between the survival rates of age groups (first-year and adult) or bill size groups, which represented birds of different sex and breeding origin. Annual survival estimates for the three roosts ranged from 72 to 77%. The percentage of first-year birds varied among roosts and years; the lowest values were during the late 1980s/early 1990s and early 2000s. A free-running population model incorporating varying percentages of first-year birds and constant mortality for each roost provided a plausible explanation for the decline. Although modelled numbers followed the observed pattern, a discrepancy in one year was carried forward in subsequent years, so that the fit with the observed numbers was parallel rather than similar. However, it seems that the decline in numbers was largely due to poorer recruitment. We discuss whether breeding success had declined, whether the
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nmr spectroscopic study and dft calculations of giao nmr shieldings
African Journals Online (AJOL)
Preferred Customer
3Department of Physics, Arts and Science Faculty, Dumlupinar University, Kütahya, ... 1H, 13C NMR chemical shifts and 1JCH coupling constants of .... then estimated using the corresponding TMS shieldings calculated in advance at the same.
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Two-dimensional NMR spectrometry
International Nuclear Information System (INIS)
Farrar, T.C.
1987-01-01
This article is the second in a two-part series. In part one (ANALYTICAL CHEMISTRY, May 15) the authors discussed one-dimensional nuclear magnetic resonance (NMR) spectra and some relatively advanced nuclear spin gymnastics experiments that provide a capability for selective sensitivity enhancements. In this article and overview and some applications of two-dimensional NMR experiments are presented. These powerful experiments are important complements to the one-dimensional experiments. As in the more sophisticated one-dimensional experiments, the two-dimensional experiments involve three distinct time periods: a preparation period, t 0 ; an evolution period, t 1 ; and a detection period, t 2
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1H-NMR/13C-NMR studies of branched structures in PVC obtained at atmospheric pressure
International Nuclear Information System (INIS)
Braun, D.; Holzer, G.; Hjertberg, T.
1981-01-01
The 1 H-NMR-spectra of raw poly (vinyl cloride) obtained at atmospheric pressure (U-PVC) have revealed the presence of high concentrations of branches. The content of labile chlorine was determined by reaction with phenole in order to estimate the branch points with tertiary chlorine. The branch length of reductively dehalogenated U-PVC by 13 C-NMR analysis have provided evidence for both short chain branches including chloromethyl groups and 2.4-dichloro-n-butyl groups and long chain branching. For a number of U-polymers the total amount of branching ranges from 7.5 to 13.5/1000 C. The 13 C-NMR measurements point to a ratio of methyl/butyl branches of 1:1 and short chains/long chains of 6:1. (orig.)
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Introduction to some basic aspects of NMR
International Nuclear Information System (INIS)
Goldman, M.
1992-01-01
The principal interactions are reviewed that are experienced by nuclear spins making magnetic resonance feasible and which disturb it in a way that gives access to the properties of bulk matter. The interactions leading to NMR include Zeeman interaction, dipole-dipole interactions, and exchange interactions. Spin-lattice relaxation relevant to NMR is revisited next. It is followed by an overview of spin temperature. Finally, the care of periodic Hamiltonian is discussed in detail as another contribution to NMR. (R.P.) 48 refs., 12 figs
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An Inversion Recovery NMR Kinetics Experiment
Williams, Travis J.; Kershaw, Allan D.; Li, Vincent; Wu, Xinping
2011-01-01
A convenient laboratory experiment is described in which NMR magnetization transfer by inversion recovery is used to measure the kinetics and thermochemistry of amide bond rotation. The experiment utilizes Varian spectrometers with the VNMRJ 2.3 software, but can be easily adapted to any NMR platform. The procedures and sample data sets in this…
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$\\beta$-NMR of copper isotopes in ionic liquids
We propose to test the feasibility of spin-polarization and $\\beta$-NMR studies on several short-lived copper isotopes, $^{58}$ Cu, $^{74}$Cu and $^{75}$Cu in crystals and liquids. The motivation is given by biological studies of Cu with $\\beta$-NMR in liquid samples, since Cu is present in a large number of enzymes involved in electron transfer and activation of oxygen. The technique is based on spin-polarization via optical pumping in the new VITO beamline. We will use the existing lasers, NMR magnet and NMR chambers and we will prepare a new optical pumping system. The studies will be devoted to tests of achieved $\\beta$-asymmetry in solid hosts, the behaviour of asymmetry when increasing vacuum, and finally NMR scans in ionic liquids. The achieved spin polarization will be also relevant for the plans to measure with high precision the magnetic moments of neutron-rich Cu isotopes.
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Quantification of aluminium-27 NMR spectra of high-surface-area oxides
International Nuclear Information System (INIS)
Pearson, R.M.; Schramm, C.M.
1990-01-01
This paper discusses the quantitation of 27 Al NMR spectra. It is showns that the so called 'invisible' aluminium atoms seen by recent workers are completely consistent with known continuous wave NMR studies of the 27 Al NMR spectra of high surface area aluminium oxides. The use of pulsed NMR techniques further complicate the quantitative measurement of 27 Al NMR spectra, especially when high resolution NMR spectrometers are used for this purpose. Methods are described which allow both the estimation of aluminium not seen by continuous wave techniques and the amounts of the NMR spectra lost in pulsed work. (author). 24 refs.; 6 figs.; 1 tab
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NMRbox: A Resource for Biomolecular NMR Computation.
Maciejewski, Mark W; Schuyler, Adam D; Gryk, Michael R; Moraru, Ion I; Romero, Pedro R; Ulrich, Eldon L; Eghbalnia, Hamid R; Livny, Miron; Delaglio, Frank; Hoch, Jeffrey C
2017-04-25
Advances in computation have been enabling many recent advances in biomolecular applications of NMR. Due to the wide diversity of applications of NMR, the number and variety of software packages for processing and analyzing NMR data is quite large, with labs relying on dozens, if not hundreds of software packages. Discovery, acquisition, installation, and maintenance of all these packages is a burdensome task. Because the majority of software packages originate in academic labs, persistence of the software is compromised when developers graduate, funding ceases, or investigators turn to other projects. To simplify access to and use of biomolecular NMR software, foster persistence, and enhance reproducibility of computational workflows, we have developed NMRbox, a shared resource for NMR software and computation. NMRbox employs virtualization to provide a comprehensive software environment preconfigured with hundreds of software packages, available as a downloadable virtual machine or as a Platform-as-a-Service supported by a dedicated compute cloud. Ongoing development includes a metadata harvester to regularize, annotate, and preserve workflows and facilitate and enhance data depositions to BioMagResBank, and tools for Bayesian inference to enhance the robustness and extensibility of computational analyses. In addition to facilitating use and preservation of the rich and dynamic software environment for biomolecular NMR, NMRbox fosters the development and deployment of a new class of metasoftware packages. NMRbox is freely available to not-for-profit users. Copyright © 2017 Biophysical Society. All rights reserved.
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Use of NMR as an online sensor in industrial processes
International Nuclear Information System (INIS)
Andrade, Fabiana Diuk de
2012-01-01
Nuclear magnetic resonance (NMR) is one of the most versatile analytical techniques for chemical, biochemical and medical applications. Despite this great success, NMR is seldom used as a tool in industrial applications. The first application of NMR in flowing samples was published in 1951. However, only in the last ten years Flow NMR has gained momentum and new and potential applications have been proposed. In this review we present the historical evolution of flow or online NMR spectroscopy and imaging, and current developments for use in the automation of industrial processes. (author)
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Selected topics in solution-phase biomolecular NMR spectroscopy
Kay, Lewis E.; Frydman, Lucio
2017-05-01
Solution bio-NMR spectroscopy continues to enjoy a preeminent role as an important tool in elucidating the structure and dynamics of a range of important biomolecules and in relating these to function. Equally impressive is how NMR continues to 'reinvent' itself through the efforts of many brilliant practitioners who ask increasingly demanding and increasingly biologically relevant questions. The ability to manipulate spin Hamiltonians - almost at will - to dissect the information of interest contributes to the success of the endeavor and ensures that the NMR technology will be well poised to contribute to as yet unknown frontiers in the future. As a tribute to the versatility of solution NMR in biomolecular studies and to the continued rapid advances in the field we present a Virtual Special Issue (VSI) that includes over 40 articles on various aspects of solution-state biomolecular NMR that have been published in the Journal of Magnetic Resonance in the past 7 years. These, in total, help celebrate the achievements of this vibrant field.
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NMR examinations of the facial skeleton. Pt. 1
International Nuclear Information System (INIS)
Grodd, W.; Lenz, M.; Baumann, R.; Schroth, G.
1984-01-01
The resolution of NMR and CT was compared using axial sections of the normal anatomic structures of the facial skeleton. Is was shown that NMR was superior in differentiating muscles, tonsils, mucosa, lymph nodes and blood vessels. The demonstration of bone and its differentiation from air-containing spaces is often difficult. Metallic, non-ferromagnetic dental fillings, which cause serious artefacts on CT, do not after NMR. (orig.) [de
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Yi, Jun; Yang, Wenhong; Sun, Wen-Hua; Nomura, Kotohiro; Hada, Masahiko
2017-11-30
The NMR chemical shifts of vanadium ( 51 V) in (imido)vanadium(V) dichloride complexes with imidazolin-2-iminato and imidazolidin-2-iminato ligands were calculated by the density functional theory (DFT) method with GIAO. The calculated 51 V NMR chemical shifts were analyzed by the multiple linear regression (MLR) analysis (MLRA) method with a series of calculated molecular properties. Some of calculated NMR chemical shifts were incorrect using the optimized molecular geometries of the X-ray structures. After the global minimum geometries of all of the molecules were determined, the trend of the observed chemical shifts was well reproduced by the present DFT method. The MLRA method was performed to investigate the correlation between the 51 V NMR chemical shift and the natural charge, band energy gap, and Wiberg bond index of the V═N bond. The 51 V NMR chemical shifts obtained with the present MLR model were well reproduced with a correlation coefficient of 0.97.
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Eye disease, the fertility decline, and the emergence of global income differences
DEFF Research Database (Denmark)
Andersen, Thomas B.; Dalgaard, Carl-Johan Lars; Selaya, Pablo
2014-01-01
This research advances and empirically establishes the hypothesis that regional variation in the historical incidence of eye disease has influenced the current global distribution of per capita income. By reducing work life expectancy, high historical eye disease incidence has served to diminish...... the incentive to accumulate skills, thereby delaying the fertility transition and the take-off to sustained economic growth. As a consequence of a differential timing of the take-off to growth, prompted by differences in the inherent return to skill formation, global income disparities have emerged....
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Susceptibility of South Korea to Extremes Affecting the Global Food System
Chon, So Young; Puma, Michael J.
2015-01-01
Food security in South Korea is tightly linked to the global food system. The country's production of major grains declined from 5.8 million metric tons (mmt) in 1998 to 4.8 mmt in 2014, which caused the country's grain self suciency to decline from 31.4% to 24%. This decline is a consequence of several factors including reductions in domestic agricultural land, governmental policies supporting industry over agriculture, and a push towards trade liberalization. South Korea's self suciency is now one of the lowest among Organisation for Economic Co-operation and Development (OECD) countries, leaving it vulnerable to disruptions in the global food system.
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Energy Technology Data Exchange (ETDEWEB)
Ebara, Masaaki; Oto, Masao; Sugiura, Nobuyuki; Kimura, Kunio; Okuda, Kunio; Hirooka, Noboru; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio
1984-06-01
Characteristics of nuclear magnetic resonance (NMR) images for various liver diseases were examined using a 0.1 T resistive NMR imaging unit on 26 patients with liver disease and 10 normal volunteers. Hepatic tumors, including small hepatocellular carcinoma 1.5 cm in diameter, were detected on NMR imaging. Ring sign characteristic of nodular type hepatocellular carcinoma was shown on NMR-CT in 60 % of patients. T/sub 1/ values allowed differential diagnosis of hepatic tumors. There was close correlation between NMR images and histopathological findings. The T/sub 1/ in the liver and spleen was more prolonged in patients with liver cirrhosis than in normal volunteers, with significant differences. (Namekawa, K.).
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NMR imaging of soft tissue tumors
International Nuclear Information System (INIS)
Laval-Jeantet, M.; Tobolsk, F.; Delepine, N.; Delepine, G.; Roger, B.; Cabanis, E.A.
1986-01-01
Preliminary findings on NMR imaging of 30 soft tissue tumors demonstrated the indispensable value of this examination (particularly when a surface antenna is used) for preoperative investigation and diagnosis of tumoral recurrence when compared with other radiologic techniques. The possible potential of NMR imaging for characterization of tissues, apart from lipoma or liposarcoma, cannot be evaluated at the present time [fr
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Solid state NMR of spin-1/2 nuclei
International Nuclear Information System (INIS)
Wind, R.A.
1991-01-01
The detection of nuclear magnetic resonance by Bloch et al. and Purcell and co-workers in 1946 has led to the development of one of the most powerful spectroscopic techniques known today. The reason is that, besides the applied external magnetic field, a nuclear spin also experiences extra local magnetic fields, which are due to surrounding electron clouds (the chemical shift) and other spins. These local fields differ for nuclei located at chemically different positions in a molecule. The result is that an NMR spectrum often consists of several lines, which can be considered to be a fingerprint of the material under investigation an can assist the clarifying its molecular structure. NMR has been especially successful in liquids and liquid like materials, where fast molecular tumblings average out the anisotropies in the local fields, resulting in well-resolved NMR spectra. This paper reports that initially the development of solid-state NMR was less dramatic. Originally, for reasons of sensitivity, attention was focused mainly on 1 H NMR. The result is that the NMR spectrum usually consists of single, broad, featureless line, which, except for special cases such as more or less isolated spin pairs or methyl groups, does not provide much information
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Liu, Haiyan; Tayyari, Fariba; Edison, Arthur S; Su, Zhihua; Gu, Liwei
2016-08-01
A (1)H NMR global metabolomics approach was used to investigate the urinary metabolome changes in female rats gavaged with partially purified cranberry procyanidins (PPCP) or partially purified apple procyanidins (PPAP). After collecting 24-h baseline urine, 24 female Sprague-Dawley rats were randomly separated into two groups and gavaged with PPCP or PPAP twice using a dose of 250 mg extracts per kilogram body weight. The 24-h urine samples were collected after the gavage. Urine samples were analyzed using (1)H NMR. Multivariate analyses showed that the urinary metabolome in rats was modified after administering PPCP or PPAP compared to baseline urine metabolic profiles. 2D (1)H-(13)C HSQC NMR was conducted to assist identification of discriminant metabolites. An increase of hippurate, lactate and succinate and a decrease of citrate and α-ketoglutarate were observed in rat urine after administering PPCP. Urinary levels of d-glucose, d-maltose, 3-(3'-hydroxyphenyl)-3-hydroxypropanoic acid, p-hydroxyphenylacetic acid, formate and phenol increased but citrate, α-ketoglutarate and creatinine decreased in rats after administering PPAP. Furthermore, the NMR analysis showed that the metabolome in the urine of rats administered with PPCP differed from those gavaged with PPAP. Compared to PPAP, PPCP caused an increase of urinary excretion of hippurate but a decrease of 3-(3'-hydroxyphenyl)-3-hydroxypropanoic acid, p-hydroxyphenylacetic acid and phenol. These metabolome changes caused by cranberry procyanidins may help to explain its reported health benefits and identify biomarkers of cranberry procyanidin intake. Copyright © 2016 Elsevier Inc. All rights reserved.
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NMR Phase Noise in Bitter Magnets
Sigmund, E. E.; Calder, E. S.; Thomas, G. W.; Mitrović, V. F.; Bachman, H. N.; Halperin, W. P.; Kuhns, P. L.; Reyes, A. P.
2001-02-01
We have studied the temporal instability of a high field resistive Bitter magnet through nuclear magnetic resonance (NMR). This instability leads to transverse spin decoherence in repeated and accumulated NMR experiments as is normally performed during signal averaging. We demonstrate this effect via Hahn echo and Carr-Purcell-Meiboom-Gill (CPMG) transverse relaxation experiments in a 23-T resistive magnet. Quantitative analysis was found to be consistent with separate measurements of the magnetic field frequency fluctuation spectrum, as well as with independent NMR experiments performed in a magnetic field with a controlled instability. Finally, the CPMG sequence with short pulse delays is shown to be successful in recovering the intrinsic spin-spin relaxation even in the presence of magnetic field temporal instability.
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International Nuclear Information System (INIS)
Gruenert, J.
1989-01-01
The book reviews the applications of NMR-spectroscopy in medicine and biology. The first chapter of about 40 pages summarizes the history of development and explains the chemical and physical fundamentals of this new and non-invasive method in an easily comprehensible manner. The other chapters summarize diagnostic results obtained with this method in organs and tissues, so that the reader will find a systematic overview of the available findings obtained in the various organ systems. It must be noted, however, that ongoing research work and new insight quite naturally will necessitate corrections to be done, as is the case here with some biochemical interpretations which would need adjustment to latest research results. NMR-spectroscopy is able to measure very fine energy differences on the molecular level, and thus offers insight into metabolic processes, with the advantage that there is no need of applying ionizing radiation in order to qualitatively or quantitatively analyse the metabolic processes in the various organ systems. (orig./DG) With 40 figs., 4 tabs [de
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Can NMR solve some significant challenges in metabolomics?
Gowda, G.A. Nagana; Raftery, Daniel
2015-01-01
The field of metabolomics continues to witness rapid growth driven by fundamental studies, methods development, and applications in a number of disciplines that include biomedical science, plant and nutrition sciences, drug development, energy and environmental sciences, toxicology, etc. NMR spectroscopy is one of the two most widely used analytical platforms in the metabolomics field, along with mass spectrometry (MS). NMR's excellent reproducibility and quantitative accuracy, its ability to identify structures of unknown metabolites, its capacity to generate metabolite profiles using intact biospecimens with no need for separation, and its capabilities for tracing metabolic pathways using isotope labeled substrates offer unique strengths for metabolomics applications. However, NMR's limited sensitivity and resolution continue to pose a major challenge and have restricted both the number and the quantitative accuracy of metabolites analyzed by NMR. Further, the analysis of highly complex biological samples has increased the demand for new methods with improved detection, better unknown identification, and more accurate quantitation of larger numbers of metabolites. Recent efforts have contributed significant improvements in these areas, and have thereby enhanced the pool of routinely quantifiable metabolites. Additionally, efforts focused on combining NMR and MS promise opportunities to exploit the combined strength of the two analytical platforms for direct comparison of the metabolite data, unknown identification and reliable biomarker discovery that continue to challenge the metabolomics field. This article presents our perspectives on the emerging trends in NMR-based metabolomics and NMR's continuing role in the field with an emphasis on recent and ongoing research from our laboratory. PMID:26476597
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Can NMR solve some significant challenges in metabolomics?
Nagana Gowda, G A; Raftery, Daniel
2015-11-01
The field of metabolomics continues to witness rapid growth driven by fundamental studies, methods development, and applications in a number of disciplines that include biomedical science, plant and nutrition sciences, drug development, energy and environmental sciences, toxicology, etc. NMR spectroscopy is one of the two most widely used analytical platforms in the metabolomics field, along with mass spectrometry (MS). NMR's excellent reproducibility and quantitative accuracy, its ability to identify structures of unknown metabolites, its capacity to generate metabolite profiles using intact bio-specimens with no need for separation, and its capabilities for tracing metabolic pathways using isotope labeled substrates offer unique strengths for metabolomics applications. However, NMR's limited sensitivity and resolution continue to pose a major challenge and have restricted both the number and the quantitative accuracy of metabolites analyzed by NMR. Further, the analysis of highly complex biological samples has increased the demand for new methods with improved detection, better unknown identification, and more accurate quantitation of larger numbers of metabolites. Recent efforts have contributed significant improvements in these areas, and have thereby enhanced the pool of routinely quantifiable metabolites. Additionally, efforts focused on combining NMR and MS promise opportunities to exploit the combined strength of the two analytical platforms for direct comparison of the metabolite data, unknown identification and reliable biomarker discovery that continue to challenge the metabolomics field. This article presents our perspectives on the emerging trends in NMR-based metabolomics and NMR's continuing role in the field with an emphasis on recent and ongoing research from our laboratory. Copyright © 2015 Elsevier Inc. All rights reserved.
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Can NMR solve some significant challenges in metabolomics?
Nagana Gowda, G. A.; Raftery, Daniel
2015-11-01
The field of metabolomics continues to witness rapid growth driven by fundamental studies, methods development, and applications in a number of disciplines that include biomedical science, plant and nutrition sciences, drug development, energy and environmental sciences, toxicology, etc. NMR spectroscopy is one of the two most widely used analytical platforms in the metabolomics field, along with mass spectrometry (MS). NMR's excellent reproducibility and quantitative accuracy, its ability to identify structures of unknown metabolites, its capacity to generate metabolite profiles using intact bio-specimens with no need for separation, and its capabilities for tracing metabolic pathways using isotope labeled substrates offer unique strengths for metabolomics applications. However, NMR's limited sensitivity and resolution continue to pose a major challenge and have restricted both the number and the quantitative accuracy of metabolites analyzed by NMR. Further, the analysis of highly complex biological samples has increased the demand for new methods with improved detection, better unknown identification, and more accurate quantitation of larger numbers of metabolites. Recent efforts have contributed significant improvements in these areas, and have thereby enhanced the pool of routinely quantifiable metabolites. Additionally, efforts focused on combining NMR and MS promise opportunities to exploit the combined strength of the two analytical platforms for direct comparison of the metabolite data, unknown identification and reliable biomarker discovery that continue to challenge the metabolomics field. This article presents our perspectives on the emerging trends in NMR-based metabolomics and NMR's continuing role in the field with an emphasis on recent and ongoing research from our laboratory.
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SPE-NMR metabolite sub-profiling of urine
Jacobs, D.M.; Spiesser, L.; Garnier, M.; Roo, de N.; Dorsten, van F.; Hollebrands, B.; Velzen, van E.; Draijer, R.; Duynhoven, van J.P.M.
2012-01-01
NMR-based metabolite profiling of urine is a fast and reproducible method for detection of numerous metabolites with diverse chemical properties. However, signal overlap in the (1)H NMR profiles of human urine may hamper quantification and identification of metabolites. Therefore, a new method has
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A primer to nutritional metabolomics by NMR spectroscopy and chemometrics
DEFF Research Database (Denmark)
Savorani, Francesco; Rasmussen, Morten Arendt; Mikkelsen, Mette Skau
2013-01-01
This paper outlines the advantages and disadvantages of using high throughput NMR metabolomics for nutritional studies with emphasis on the workflow and data analytical methods for generation of new knowledge. The paper describes one-by-one the major research activities in the interdisciplinary...... metabolomics platform and highlights the opportunities that NMR spectra can provide in future nutrition studies. Three areas are emphasized: (1) NMR as an unbiased and non-destructive platform for providing an overview of the metabolome under investigation, (2) NMR for providing versatile information and data...... structures for multivariate pattern recognition methods and (3) NMR for providing a unique fingerprint of the lipoprotein status of the subject. For the first time in history, by combining NMR spectroscopy and chemometrics we are able to perform inductive nutritional research as a complement to the deductive...
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Nuclear magnetic resonance (NMR): principles and applications
International Nuclear Information System (INIS)
Quibilan, E.I.
The basis for the phenomenon of nuclear magnetic resonance (NMR) is the ability of certain nuclei possessing both intrinsic angular momentum or ''spin'' I and magnetic moment to absorb electromagnetic energy in the radio frequency range. In principle, there are approximately 200 nuclei which may be investigated using the NMR technique. The NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum consists of intensity peaks along an axis calibrated in terms of the steady magnetic field or the frequency of the radiofrequency electromagnetic radiation. Analysis of the number, spacing, position and intensity of the lines in an NMR spectrum provides a variety of qualitative and quantitative analytical applications. The most obvious applications consist of the measurements of nuclear properties, such as spin number and nuclear magnetic moment. In liquids, the fine structure of resonance spectra provides a tool for chemical identification and molecular structure analysis. Other applications include the measurements of self-diffusion coefficients, magnetic fields and field homogeneity, inter-nuclear distances, and, in some cases, the water content of biological materials. (author)
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Chirp echo Fourier transform EPR-detected NMR.
Wili, Nino; Jeschke, Gunnar
2018-04-01
A new ultra-wide band (UWB) pulse EPR method is introduced for observing all nuclear frequencies of a paramagnetic center in a single shot. It is based on burning spectral holes with a high turning angle (HTA) pulse that excites forbidden transitions and subsequent detection of the hole pattern by a chirp echo. We term this method Chirp Echo Epr SpectroscopY (CHEESY)-detected NMR. The approach is a revival of FT EPR-detected NMR. It yields similar spectra and the same type of information as electron-electron double resonance (ELDOR)-detected NMR, but with a multiplex advantage. We apply CHEESY-detected NMR in Q band to nitroxides and correlate the hyperfine spectrum to the EPR spectrum by varying the frequency of the HTA pulse. Furthermore, a selective π pulse before the HTA pulse allows for detecting hyperfine sublevel correlations between transitions of one nucleus and for elucidating the coupling regime, the same information as revealed by the HYSCORE experiment. This is demonstrated on hexaaquamanganese(II). We expect that CHEESY-detected NMR is generally applicable to disordered systems and that our results further motivate the development of EPR spectrometers capable of coherent UWB excitation and detection, especially at higher fields and frequencies. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.
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Chirp echo Fourier transform EPR-detected NMR
Wili, Nino; Jeschke, Gunnar
2018-04-01
A new ultra-wide band (UWB) pulse EPR method is introduced for observing all nuclear frequencies of a paramagnetic center in a single shot. It is based on burning spectral holes with a high turning angle (HTA) pulse that excites forbidden transitions and subsequent detection of the hole pattern by a chirp echo. We term this method Chirp Echo Epr SpectroscopY (CHEESY)-detected NMR. The approach is a revival of FT EPR-detected NMR. It yields similar spectra and the same type of information as electron-electron double resonance (ELDOR)-detected NMR, but with a multiplex advantage. We apply CHEESY-detected NMR in Q band to nitroxides and correlate the hyperfine spectrum to the EPR spectrum by varying the frequency of the HTA pulse. Furthermore, a selective π pulse before the HTA pulse allows for detecting hyperfine sublevel correlations between transitions of one nucleus and for elucidating the coupling regime, the same information as revealed by the HYSCORE experiment. This is demonstrated on hexaaquamanganese(II). We expect that CHEESY-detected NMR is generally applicable to disordered systems and that our results further motivate the development of EPR spectrometers capable of coherent UWB excitation and detection, especially at higher fields and frequencies.
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Hyperpolarized NMR Probes for Biological Assays
Directory of Open Access Journals (Sweden)
Sebastian Meier
2014-01-01
Full Text Available During the last decade, the development of nuclear spin polarization enhanced (hyperpolarized molecular probes has opened up new opportunities for studying the inner workings of living cells in real time. The hyperpolarized probes are produced ex situ, introduced into biological systems and detected with high sensitivity and contrast against background signals using high resolution NMR spectroscopy. A variety of natural, derivatized and designed hyperpolarized probes has emerged for diverse biological studies including assays of intracellular reaction progression, pathway kinetics, probe uptake and export, pH, redox state, reactive oxygen species, ion concentrations, drug efficacy or oncogenic signaling. These probes are readily used directly under natural conditions in biofluids and are often directly developed and optimized for cellular assays, thus leaving little doubt about their specificity and utility under biologically relevant conditions. Hyperpolarized molecular probes for biological NMR spectroscopy enable the unbiased detection of complex processes by virtue of the high spectral resolution, structural specificity and quantifiability of NMR signals. Here, we provide a survey of strategies used for the selection, design and use of hyperpolarized NMR probes in biological assays, and describe current limitations and developments.
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Some exercises in quantitative NMR imaging
International Nuclear Information System (INIS)
Bakker, C.J.G.
1985-01-01
The articles represented in this thesis result from a series of investigations that evaluate the potential of NMR imaging as a quantitative research tool. In the first article the possible use of proton spin-lattice relaxation time T 1 in tissue characterization, tumor recognition and monitoring tissue response to radiotherapy is explored. The next article addresses the question whether water proton spin-lattice relaxation curves of biological tissues are adequately described by a single time constant T 1 , and analyzes the implications of multi-exponentiality for quantitative NMR imaging. In the third article the use of NMR imaging as a quantitative research tool is discussed on the basis of phantom experiments. The fourth article describes a method which enables unambiguous retrieval of sign information in a set of magnetic resonance images of the inversion recovery type. The next article shows how this method can be adapted to allow accurate calculation of T 1 pictures on a pixel-by-pixel basis. The sixth article, finally, describes a simulation procedure which enables a straightforward determination of NMR imaging pulse sequence parameters for optimal tissue contrast. (orig.)
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HbA1c, diabetes and cognitive decline: the English Longitudinal Study of Ageing.
Zheng, Fanfan; Yan, Li; Yang, Zhenchun; Zhong, Baoliang; Xie, Wuxiang
2018-04-01
The aim of the study was to evaluate longitudinal associations between HbA 1c levels, diabetes status and subsequent cognitive decline over a 10 year follow-up period. Data from wave 2 (2004-2005) to wave 7 (2014-2015) of the English Longitudinal Study of Ageing (ELSA) were analysed. Cognitive function was assessed at baseline (wave 2) and reassessed every 2 years at waves 3-7. Linear mixed models were used to evaluate longitudinal associations. The study comprised 5189 participants (55.1% women, mean age 65.6 ± 9.4 years) with baseline HbA 1c levels ranging from 15.9 to 126.3 mmol/mol (3.6-13.7%). The mean follow-up duration was 8.1 ± 2.8 years and the mean number of cognitive assessments was 4.9 ± 1.5. A 1 mmol/mol increment in HbA 1c was significantly associated with an increased rate of decline in global cognitive z scores (-0.0009 SD/year, 95% CI -0.0014, -0.0003), memory z scores (-0.0005 SD/year, 95% CI -0.0009, -0.0001) and executive function z scores (-0.0008 SD/year, 95% CI -0.0013, -0.0004) after adjustment for baseline age, sex, total cholesterol, HDL-cholesterol, triacylglycerol, high-sensitivity C-reactive protein, BMI, education, marital status, depressive symptoms, current smoking, alcohol consumption, hypertension, CHD, stroke, chronic lung disease and cancer. Compared with participants with normoglycaemia, the multivariable-adjusted rate of global cognitive decline associated with prediabetes and diabetes was increased by -0.012 SD/year (95% CI -0.022, -0.002) and -0.031 SD/year (95% CI -0.046, -0.015), respectively (p for trend cognitive decline with diabetes. Significant longitudinal associations between HbA 1c levels, diabetes status and long-term cognitive decline were observed in this study. Future studies are required to determine the effects of maintaining optimal glucose control on the rate of cognitive decline in people with diabetes.
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Casanova, Federico; Blümich, Bernhard
2011-01-01
Single-Sided NMR describes the design of the first functioning single-sided tomograph, the related measurement methods, and a number of applications. One of the key advantages to this method is the speed at which the images are obtained.
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Chocolate Consumption is Associated with a Lower Risk of Cognitive Decline.
Moreira, Afonso; Diógenes, Maria José; de Mendonça, Alexandre; Lunet, Nuno; Barros, Henrique
2016-05-06
Cocoa-related products like chocolate have taken an important place in our food habits and culture. In this work, we aim to examine the relationship between chocolate consumption and cognitive decline in an elderly cognitively healthy population. In the present longitudinal prospective study, a cohort of 531 participants aged 65 and over with normal Mini-Mental State Examination (MMSE; median 28) was selected. The median follow-up was 48 months. Dietary habits were evaluated at baseline. The MMSE was used to assess global cognitive function at baseline and at follow-up. Cognitive decline was defined by a decrease ≥ 2 points in the MMSE score between evaluations. Relative risk (RR) and 95% confidence interval (95% CI) estimates were adjusted for age, education, smoking, alcohol drinking, body mass index, hypertension, and diabetes. Chocolate intake was associated with a lower risk of cognitive decline (RR = 0.59, 95% CI 0.38-0.92). This protective effect was observed only among subjects with an average daily consumption of caffeine lower than 75 mg (69% of the participants; RR = 0.50, 95% CI 0.31-0.82). To our knowledge, this is the first prospective cohort study to show an inverse association between regular long-term chocolate consumption and cognitive decline in humans.
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Structural biology by NMR: structure, dynamics, and interactions.
Directory of Open Access Journals (Sweden)
Phineus R L Markwick
2008-09-01
Full Text Available The function of bio-macromolecules is determined by both their 3D structure and conformational dynamics. These molecules are inherently flexible systems displaying a broad range of dynamics on time-scales from picoseconds to seconds. Nuclear Magnetic Resonance (NMR spectroscopy has emerged as the method of choice for studying both protein structure and dynamics in solution. Typically, NMR experiments are sensitive both to structural features and to dynamics, and hence the measured data contain information on both. Despite major progress in both experimental approaches and computational methods, obtaining a consistent view of structure and dynamics from experimental NMR data remains a challenge. Molecular dynamics simulations have emerged as an indispensable tool in the analysis of NMR data.
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NMR studies of cerebral metabolism in vivo
International Nuclear Information System (INIS)
Prichard, J.W.
1986-01-01
The nature and extent of the potential synergism between PET and NMR methods is not yet well appreciated in the biomedical community. The long-range interest of medical neurobiology will be well served by efforts of PET and NMR scientists to follow each others' work so that opportunities for productive interchange can be efficiently exploited. Appreciation of the synergism by the rest of the biomedical community will follow naturally. PET is said by the people doing it to be still in its infancy, for they are more concerned with advancing their discipline than with admiring its already impressive achievements. On the scale of the same developmental metaphor, many NMR methods for studying the living human brain are still in utero. The best way to provide the reader a sense of the current status and future course of NMR research in medical neurobiology is by discussion of published in vivo studies. Such a discussion, adapted from another article is what follows
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High resolution NMR theory and chemical applications
Becker, Edwin D
2012-01-01
High Resolution NMR: Theory and Chemical Applications discusses the principles and theory of nuclear magnetic resonance and how this concept is used in the chemical sciences. This book is written at an intermediate level, with mathematics used to augment verbal descriptions of the phenomena. This text pays attention to developing and interrelating four approaches - the steady state energy levels, the rotating vector picture, the density matrix, and the product operator formalism. The style of this book is based on the assumption that the reader has an acquaintance with the general principles of quantum mechanics, but no extensive background in quantum theory or proficiency in mathematics is required. This book begins with a description of the basic physics, together with a brief account of the historical development of the field. It looks at the study of NMR in liquids, including high resolution NMR in the solid state and the principles of NMR imaging and localized spectroscopy. This book is intended to assis...
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Phosphoproteomics analysis of postmortem porcine muscle with pH decline rate and time difference
DEFF Research Database (Denmark)
Huang, Honggang; Larsen, Martin R; Karlsson, Anders H
2012-01-01
The aim of this study was to characterize the protein phosphorylation in postmortem (PM) muscle and reveal the change during meat quality development. The gel-based phosphoproteomic analysis of PM porcine muscle was performed in three pig groups with different pH decline rates from PM 1h to 24 h....... The sarcoplasmic and myofibrillar fractions were analyzed using gel electrophoresis in combination with a phosphoprotein specific staining. Globally, the group with fast pH decline rate had the highest phosphorylation level at PM 1 h, but lowest at PM 24 h, whereas the group with slow pH decline rate showed...... the reverse case. The phosphorylation level of 12 bands in sarcoplasmic fraction and 3 bands in myofibrillar fraction were significantly affected by the synergy effects of pH and time (p
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DNP-enhanced solid-state NMR spectroscopy of active pharmaceutical ingredients.
Zhao, Li; Pinon, Arthur C; Emsley, Lyndon; Rossini, Aaron J
2017-11-28
Solid-state NMR spectroscopy has become a valuable tool for the characterization of both pure and formulated active pharmaceutical ingredients (APIs). However, NMR generally suffers from poor sensitivity that often restricts NMR experiments to nuclei with favorable properties, concentrated samples, and acquisition of one-dimensional (1D) NMR spectra. Here, we review how dynamic nuclear polarization (DNP) can be applied to routinely enhance the sensitivity of solid-state NMR experiments by one to two orders of magnitude for both pure and formulated APIs. Sample preparation protocols for relayed DNP experiments and experiments on directly doped APIs are detailed. Numerical spin diffusion models illustrate the dependence of relayed DNP enhancements on the relaxation properties and particle size of the solids and can be used for particle size determination when the other factors are known. We then describe the advanced solid-state NMR experiments that have been enabled by DNP and how they provide unique insight into the molecular and macroscopic structure of APIs. For example, with large sensitivity gains provided by DNP, natural isotopic abundance, 13 C- 13 C double-quantum single-quantum homonuclear correlation NMR spectra of pure APIs can be routinely acquired. DNP also enables solid-state NMR experiments with unreceptive quadrupolar nuclei such as 2 H, 14 N, and 35 Cl that are commonly found in APIs. Applications of DNP-enhanced solid-state NMR spectroscopy for the molecular level characterization of low API load formulations such as commercial tablets and amorphous solid dispersions are described. Future perspectives for DNP-enhanced solid-state NMR experiments on APIs are briefly discussed. Copyright © 2017 John Wiley & Sons, Ltd.
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The NMR Probe of High-T$_{c}$ Materials
Walstedt, Russell E
2008-01-01
The NMR probe has yielded a vast array of data for the high-Tc materials, corresponding to different compounds, ionic sites, and nuclear species, as well as to a wide variety of experimental conditions. Over the twenty years, since the discovery of superconducting cuprates, ongoing analysis and discussion of cuprate NMR data have resulted in a wealth of important insights into the physics of these exotic systems. The aims of this monograph are threefold. First, it reviews NMR methodology as it has been applied to the cuprate studies. This is addressed to NMR practitioners and to physics laypersons alike. Next, it presents a review of cuprate NMR measurements and the wide variety of phenomena which they represent. The third phase is to recount the theoretical model calculations and other proposals which have been put forward to account for these data. Parts two and three are presented in parallel, as there are many aspects to both topics, each with its own interesting history. There is, even twenty years on, a...
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Prediction of peak overlap in NMR spectra
International Nuclear Information System (INIS)
Hefke, Frederik; Schmucki, Roland; Güntert, Peter
2013-01-01
Peak overlap is one of the major factors complicating the analysis of biomolecular NMR spectra. We present a general method for predicting the extent of peak overlap in multidimensional NMR spectra and its validation using both, experimental data sets and Monte Carlo simulation. The method is based on knowledge of the magnetization transfer pathways of the NMR experiments and chemical shift statistics from the Biological Magnetic Resonance Data Bank. Assuming a normal distribution with characteristic mean value and standard deviation for the chemical shift of each observable atom, an analytic expression was derived for the expected overlap probability of the cross peaks. The analytical approach was verified to agree with the average peak overlap in a large number of individual peak lists simulated using the same chemical shift statistics. The method was applied to eight proteins, including an intrinsically disordered one, for which the prediction results could be compared with the actual overlap based on the experimentally measured chemical shifts. The extent of overlap predicted using only statistical chemical shift information was in good agreement with the overlap that was observed when the measured shifts were used in the virtual spectrum, except for the intrinsically disordered protein. Since the spectral complexity of a protein NMR spectrum is a crucial factor for protein structure determination, analytical overlap prediction can be used to identify potentially difficult proteins before conducting NMR experiments. Overlap predictions can be tailored to particular classes of proteins by preparing statistics from corresponding protein databases. The method is also suitable for optimizing recording parameters and labeling schemes for NMR experiments and improving the reliability of automated spectra analysis and protein structure determination.
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Energy Technology Data Exchange (ETDEWEB)
Taylor, Sharon A; Ferguson, David B; Haw, James F [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry
1994-12-31
In situ NMR experiments are studied, including probe of several structures such as the structures of the organic adsorbates, Broensted acid sites, other nuclei associated with active sites, and other framework sites. The authors report that in the absence of high concentrations of paramagnetic sites or metal particles, high resolution MAS spectra are relatively easy to obtain and interpret. It is also concluded that NMR can measure spatial distributions and rates of diffusion; and are able to characterize equilibrium structures and the frequencies and amplitudes of molecular motion
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Progress, decline, and the public uptake of climate science.
Rudiak-Gould, Peter
2014-02-01
Previous research has sought to explain public perception of climate change science in terms of individuals' "prior commitment" to such ideological stances as just-world belief, system justification, and liberalism/conservatism. One type of prior commitment that has received little formal attention in the literature is narratives of the moral trajectory of society. A theory of climate science uptake based on beliefs in societal progress or decline is more easily portable to non-Western settings; in a case study of global warming attitudes in the Marshall Islands, trajectory narratives indeed account for public belief, concern, blame, and response more aptly than existing theories, and accord well with qualitative analysis of Marshallese climate change discourse. In Western settings, progress/decline narratives may explain much of the variation in climate change attitudes previously accounted for by other ideological variables, promising a more penetrating explanation for the divergence of climate change attitudes within and between societies.
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Identifying species conservation strategies to reduce disease-associated declines
Gerber, Brian D.; Converse, Sarah J.; Muths, Erin L.; Crockett, Harry J.; Mosher, Brittany A.; Bailey, Larissa L.
2018-01-01
Emerging infectious diseases (EIDs) are a salient threat to many animal taxa, causing local and global extinctions, altering communities and ecosystem function. The EID chytridiomycosis is a prominent driver of amphibian declines, which is caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd). To guide conservation policy, we developed a predictive decision-analytic model that combines empirical knowledge of host-pathogen metapopulation dynamics with expert judgment regarding effects of management actions, to select from potential conservation strategies. We apply our approach to a boreal toad (Anaxyrus boreas boreas) and Bd system, identifying optimal strategies that balance tradeoffs in maximizing toad population persistence and landscape-level distribution, while considering costs. The most robust strategy is expected to reduce the decline of toad breeding sites from 53% to 21% over 50 years. Our findings are incorporated into management policy to guide conservation planning. Our online modeling application provides a template for managers of other systems challenged by EIDs.
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NMR imaging of the brain: initial impressions
International Nuclear Information System (INIS)
Spencer, D.H.; Bydder, G.M.
1983-01-01
An NMR imaging system designed and built by Thorn-EMI Ltd was installed at Hammersmith Hospital in March 1981. In the first year of operation 180 patients and 40 volunteers have had cranial examinations and initial impressions bases on this experience are presented. Patients with a wide variety of neurological diseases have been studied to provide a basis for diagnostic interpretation, to define distinctive features, and to evaluate different types of scanning sequences. NMR imaging appears to be of considerable value in neurological diagnosis and has a number of advantages over CT. The detailed evaluation of NMR imaging will require much more work but the initial results are very promising
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Graphical programming for pulse automated NMR experiments
International Nuclear Information System (INIS)
Belmonte, S.B.; Oliveira, I.S.; Guimaraes, A.P.
1999-01-01
We describe a software program designed to control a broadband pulse Nuclear Magnetic Resonance (NMR) spectrometer used in zero-field NMR studies of magnetic metals. The software is written in the graphical language LabVIEW. This type of programming allows modifications and the inclusion of new routines to be easily made by the non-specialist, without changing the basic structure of the program. The program corrects for differences in the gain of the two acquisition channels [U (phase) and V (quadrature)], and automatic baseline subtraction. We present examples of measurements of NMR spectra, spin-echo decay (T 2 ), and quadrupolar oscillations, performed in magnetic intermetallic compounds. (author)
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The characterisation of polymers using pulsed NMR
International Nuclear Information System (INIS)
Charlesby, A.
1983-01-01
Broad line pulsed NMR is applied to obtain information on radiation-induced polymer changes and other aspects of polymer science based on the interpretation of spin-spin relaxation curves. Calculations are made to determine the molecular weight, the crosslink density of simple, low molecular weight, flexible polymers. For higher molecular weight polymers, a conclusion can be drawn on the concentrations of entangled and crosslinked units by means of pulsed NMR. Some typical applications of the technique are illustrated by the examples of polyethylenes, rubbers, filled polymeric systems and aqueous polyethylene oxide solutions. The morphology of polymers can be followed by pulsed NMR. (V.N.)
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Using Cloud Storage for NMR Data Distribution
Soulsby, David
2012-01-01
An approach using Google Groups as method for distributing student-acquired NMR data has been implemented. We describe how to configure NMR spectrometer software so that data is uploaded to a laboratory section specific Google Group, thereby removing bottlenecks associated with printing and processing at the spectrometer workstation. Outside of…
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Synthesis and NMR Elucidation of Novel Pentacycloundecane ...
African Journals Online (AJOL)
Herein we report the synthesis and NMR elucidation of five novel pentacycloundecane (PCU)-derived short peptides as potential HIV protease inhibitors. 1H and 13C spectral analysis show major overlapping of methine resonance of the PCU 'cage' thereby making it extremely difficult to assign the NMR signals. Attachment ...
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Isotope labeling strategies for NMR studies of RNA
International Nuclear Information System (INIS)
Lu, Kun; Miyazaki, Yasuyuki; Summers, Michael F.
2010-01-01
The known biological functions of RNA have expanded in recent years and now include gene regulation, maintenance of sub-cellular structure, and catalysis, in addition to propagation of genetic information. As for proteins, RNA function is tightly correlated with structure. Unlike proteins, structural information for larger, biologically functional RNAs is relatively limited. NMR signal degeneracy, relaxation problems, and a paucity of long-range 1 H- 1 H dipolar contacts have limited the utility of traditional NMR approaches. Selective isotope labeling, including nucleotide-specific and segmental labeling strategies, may provide the best opportunities for obtaining structural information by NMR. Here we review methods that have been developed for preparing and purifying isotopically labeled RNAs, as well as NMR strategies that have been employed for signal assignment and structure determination.
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Isotope labeling for NMR studies of macromolecular structure and interactions
International Nuclear Information System (INIS)
Wright, P.E.
1994-01-01
Implementation of biosynthetic methods for uniform or specific isotope labeling of proteins, coupled with the recent development of powerful heteronuclear multidimensional NMR methods, has led to a dramatic increase in the size and complexity of macromolecular systems that are now amenable to NMR structural analysis. In recent years, a new technology has emerged that combines uniform 13 C, 15 N labeling with heteronuclear multidimensional NMR methods to allow NMR structural studies of systems approaching 25 to 30 kDa in molecular weight. In addition, with the introduction of specific 13 C and 15 N labels into ligands, meaningful NMR studies of complexes of even higher molecular weight have become feasible. These advances usher in a new era in which the earlier, rather stringent molecular weight limitations have been greatly surpassed and NMR can begin to address many central biological problems that involve macromolecular structure, dynamics, and interactions
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Isotope labeling for NMR studies of macromolecular structure and interactions
Energy Technology Data Exchange (ETDEWEB)
Wright, P.E. [Scripps Research Institute, La Jolla, CA (United States)
1994-12-01
Implementation of biosynthetic methods for uniform or specific isotope labeling of proteins, coupled with the recent development of powerful heteronuclear multidimensional NMR methods, has led to a dramatic increase in the size and complexity of macromolecular systems that are now amenable to NMR structural analysis. In recent years, a new technology has emerged that combines uniform {sup 13}C, {sup 15}N labeling with heteronuclear multidimensional NMR methods to allow NMR structural studies of systems approaching 25 to 30 kDa in molecular weight. In addition, with the introduction of specific {sup 13}C and {sup 15}N labels into ligands, meaningful NMR studies of complexes of even higher molecular weight have become feasible. These advances usher in a new era in which the earlier, rather stringent molecular weight limitations have been greatly surpassed and NMR can begin to address many central biological problems that involve macromolecular structure, dynamics, and interactions.
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[Non-invasive analysis of proteins in living cells using NMR spectroscopy].
Tochio, Hidehito; Murayama, Shuhei; Inomata, Kohsuke; Morimoto, Daichi; Ohno, Ayako; Shirakawa, Masahiro
2015-01-01
NMR spectroscopy enables structural analyses of proteins and has been widely used in the structural biology field in recent decades. NMR spectroscopy can be applied to proteins inside living cells, allowing characterization of their structures and dynamics in intracellular environments. The simplest "in-cell NMR" approach employs bacterial cells; in this approach, live Escherichia coli cells overexpressing a specific protein are subjected to NMR. The cells are grown in an NMR active isotope-enriched medium to ensure that the overexpressed proteins are labeled with the stable isotopes. Thus the obtained NMR spectra, which are derived from labeled proteins, contain atomic-level information about the structure and dynamics of the proteins. Recent progress enables us to work with higher eukaryotic cells such as HeLa and HEK293 cells, for which a number of techniques have been developed to achieve isotope labeling of the specific target protein. In this review, we describe successful use of electroporation for in-cell NMR. In addition, (19)F-NMR to characterize protein-ligand interactions in cells is presented. Because (19)F nuclei rarely exist in natural cells, when (19)F-labeled proteins are delivered into cells and (19)F-NMR signals are observed, one can safely ascertain that these signals originate from the delivered proteins and not other molecules.
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Solid-state NMR on complex biomolecules: novel methods and applications
Nand, D.
2011-01-01
Solid-state NMR (ssNMR) represents a versatile technique in providing atomic-resolution information without the need for crystals or fast molecular motion required for X-ray crystallography and solution-state NMR, respectively. Recent past has witnessed the ability of this technique in providing
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Recent advances in solid state NMR and its application to ceramics
International Nuclear Information System (INIS)
Maekawa, Hideki
2006-01-01
The basic principles of solid state NMR are explained. Four application examples contained amorphous glass, determination of defects of oxide crystal, nano particle and ionic materials. The structure of inorganic glass is measured by 29 Si, 11 B, 31 P and 23 Na NMR and Magic Angle Spinning NMR (MAS-NMR), chemical species near hydrogen by Cross-Polarization Magic Angle Spinning (CP/MAS) method, and hydrogen by Combined Rotation And Multiple Pulse Spectroscopy (CRAMPS) and MAS-NMR. Hydrous and anhydrous silicate glass with condensed 17 O was measured by 17 O Multi Quantum Magic Angle Spinning (MQ/MAS). 27 Al in slags was analyzed by 27 Al 5Q-MAS. 89 Y NMR spectrum of YSZ (Yttria Stabilization Zirconia, Y 2 O 3 -ZrO 2 ) was explained. The ion transfer phenomena in the electrolyte are observed directly by the solid state NMR. (S.Y.)
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Schenk, David J; Dormer, Peter G; Hesk, David; Pollack, Scott R; Lavey, Carolee Flader
2015-06-15
Compounds containing tritium are widely used across the drug discovery and development landscape. These materials are widely utilized because they can be efficiently synthesized and produced at high specific activity. Results from internally calibrated (3)H and (1)H nuclear magnetic resonance (NMR) spectroscopy suggests that at least in some cases, this calibrated approach could supplement or potentially replace radio-high-performance liquid chromatography for radiochemical purity, dilution and scintillation counting for the measurement of radioactivity per volume, and liquid chromatography/mass spectrometry analysis for the determination of specific activity. In summary, the NMR-derived values agreed with those from the standard approaches to within 1% to 9% for solution count and specific activity. Additionally, the NMR-derived values for radiochemical purity deviated by less than 5%. A benefit of this method is that these values may be calculated at the same time that (3)H NMR analysis provides the location and distribution of tritium atoms within the molecule. Presented and discussed here is the application of this method, advantages and disadvantages of the approach, and a rationale for utilizing internally calibrated (1)H and (3)H NMR spectroscopy for specific activity, radioactive concentration, and radiochemical purity whenever acquiring (3)H NMR for tritium location. Copyright © 2015 John Wiley & Sons, Ltd.
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Development of 19F-NMR chemical shift detection of DNA B-Z equilibrium using 19F-NMR.
Nakamura, S; Yang, H; Hirata, C; Kersaudy, F; Fujimoto, K
2017-06-28
Various DNA conformational changes are in correlation with biological events. In particular, DNA B-Z equilibrium showed a high correlation with translation and transcription. In this study, we developed a DNA probe containing 5-trifluoromethylcytidine or 5-trifluoromethylthymidine to detect DNA B-Z equilibrium using 19 F-NMR. Its probe enabled the quantitative detection of B-, Z-, and ss-DNA based on 19 F-NMR chemical shift change.
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A software framework for analysing solid-state MAS NMR data
International Nuclear Information System (INIS)
Stevens, Tim J.; Fogh, Rasmus H.; Boucher, Wayne; Higman, Victoria A.; Eisenmenger, Frank; Bardiaux, Benjamin; Rossum, Barth-Jan van; Oschkinat, Hartmut; Laue, Ernest D.
2011-01-01
Solid-state magic-angle-spinning (MAS) NMR of proteins has undergone many rapid methodological developments in recent years, enabling detailed studies of protein structure, function and dynamics. Software development, however, has not kept pace with these advances and data analysis is mostly performed using tools developed for solution NMR which do not directly address solid-state specific issues. Here we present additions to the CcpNmr Analysis software package which enable easier identification of spinning side bands, straightforward analysis of double quantum spectra, automatic consideration of non-uniform labelling schemes, as well as extension of other existing features to the needs of solid-state MAS data. To underpin this, we have updated and extended the CCPN data model and experiment descriptions to include transfer types and nomenclature appropriate for solid-state NMR experiments, as well as a set of experiment prototypes covering the experiments commonly employed by solid-sate MAS protein NMR spectroscopists. This work not only improves solid-state MAS NMR data analysis but provides a platform for anyone who uses the CCPN data model for programming, data transfer, or data archival involving solid-state MAS NMR data.
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Fluid-Rock Characterization and Interactions in NMR Well Logging
Energy Technology Data Exchange (ETDEWEB)
Hirasaki, George J.; Mohanty, Kishore K.
2003-02-10
The objective of this project was to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity.
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Quantitative analysis of protein-ligand interactions by NMR.
Furukawa, Ayako; Konuma, Tsuyoshi; Yanaka, Saeko; Sugase, Kenji
2016-08-01
Protein-ligand interactions have been commonly studied through static structures of the protein-ligand complex. Recently, however, there has been increasing interest in investigating the dynamics of protein-ligand interactions both for fundamental understanding of the underlying mechanisms and for drug development. NMR is a versatile and powerful tool, especially because it provides site-specific quantitative information. NMR has widely been used to determine the dissociation constant (KD), in particular, for relatively weak interactions. The simplest NMR method is a chemical-shift titration experiment, in which the chemical-shift changes of a protein in response to ligand titration are measured. There are other quantitative NMR methods, but they mostly apply only to interactions in the fast-exchange regime. These methods derive the dissociation constant from population-averaged NMR quantities of the free and bound states of a protein or ligand. In contrast, the recent advent of new relaxation-based experiments, including R2 relaxation dispersion and ZZ-exchange, has enabled us to obtain kinetic information on protein-ligand interactions in the intermediate- and slow-exchange regimes. Based on R2 dispersion or ZZ-exchange, methods that can determine the association rate, kon, dissociation rate, koff, and KD have been developed. In these approaches, R2 dispersion or ZZ-exchange curves are measured for multiple samples with different protein and/or ligand concentration ratios, and the relaxation data are fitted to theoretical kinetic models. It is critical to choose an appropriate kinetic model, such as the two- or three-state exchange model, to derive the correct kinetic information. The R2 dispersion and ZZ-exchange methods are suitable for the analysis of protein-ligand interactions with a micromolar or sub-micromolar dissociation constant but not for very weak interactions, which are typical in very fast exchange. This contrasts with the NMR methods that are used
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Accurate, fully-automated NMR spectral profiling for metabolomics.
Directory of Open Access Journals (Sweden)
Siamak Ravanbakhsh
Full Text Available Many diseases cause significant changes to the concentrations of small molecules (a.k.a. metabolites that appear in a person's biofluids, which means such diseases can often be readily detected from a person's "metabolic profile"-i.e., the list of concentrations of those metabolites. This information can be extracted from a biofluids Nuclear Magnetic Resonance (NMR spectrum. However, due to its complexity, NMR spectral profiling has remained manual, resulting in slow, expensive and error-prone procedures that have hindered clinical and industrial adoption of metabolomics via NMR. This paper presents a system, BAYESIL, which can quickly, accurately, and autonomously produce a person's metabolic profile. Given a 1D 1H NMR spectrum of a complex biofluid (specifically serum or cerebrospinal fluid, BAYESIL can automatically determine the metabolic profile. This requires first performing several spectral processing steps, then matching the resulting spectrum against a reference compound library, which contains the "signatures" of each relevant metabolite. BAYESIL views spectral matching as an inference problem within a probabilistic graphical model that rapidly approximates the most probable metabolic profile. Our extensive studies on a diverse set of complex mixtures including real biological samples (serum and CSF, defined mixtures and realistic computer generated spectra; involving > 50 compounds, show that BAYESIL can autonomously find the concentration of NMR-detectable metabolites accurately (~ 90% correct identification and ~ 10% quantification error, in less than 5 minutes on a single CPU. These results demonstrate that BAYESIL is the first fully-automatic publicly-accessible system that provides quantitative NMR spectral profiling effectively-with an accuracy on these biofluids that meets or exceeds the performance of trained experts. We anticipate this tool will usher in high-throughput metabolomics and enable a wealth of new applications of
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Portable, Low-cost NMR with Laser-Lathe Lithography Produced
Energy Technology Data Exchange (ETDEWEB)
Herberg, J L; Demas, V; Malba, V; Bernhardt, A; Evans, L; Harvey, C; Chinn, S; Maxwell, R; Reimer, J; Pines, A
2006-12-21
Nuclear Magnetic Resonance (NMR) is unsurpassed in its ability to non-destructively probe chemical identity. Portable, low-cost NMR sensors would enable on-site identification of potentially hazardous substances, as well as the study of samples in a variety of industrial applications. Recent developments in RF microcoil construction (i.e. coils much smaller than the standard 5 mm NMR RF coils), have dramatically increased NMR sensitivity and decreased the limits-of-detection (LOD). We are using advances in laser pantographic microfabrication techniques, unique to LLNL, to produce RF microcoils for field deployable, high sensitivity NMR-based detectors. This same fabrication technique can be used to produce imaging coils for MRI as well as for standard hardware shimming or 'ex-situ' shimming of field inhomogeneities typically associated with inexpensive magnets. This paper describes a portable NMR system based on a laser-fabricated microcoil and homebuilt probe design. For testing this probe, we used a hand-held 2 kg Halbach magnet that can fit into the palm of a hand, and an RF probe with laser-fabricated microcoils. The focus of the paper is on the evaluation of the microcoils, RF probe, and first generation gradient coils. The setup of this system, initial results, sensitivity measurements, and future plans are discussed. The results, even though preliminary, are promising and provide the foundation for developing a portable, inexpensive NMR system for chemical analysis. Such a system will be ideal for chemical identification of trace substances on site.
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High resolution deuterium NMR studies of bacterial metabolism
Energy Technology Data Exchange (ETDEWEB)
Aguayo, J.B.; Gamcsik, M.P.; Dick, J.D.
1988-12-25
High resolution deuterium NMR spectra were obtained from suspensions of five bacterial strains: Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus. Deuterium-labeled D-glucose at C-1, C-2, and C-6 was used to monitor dynamically anaerobic metabolism. The flux of glucose through the various bacterial metabolic pathways could be determined by following the disappearance of glucose and the appearance of the major end products in the 2H NMR spectrum. The presence of both labeled and unlabeled metabolites could be detected using 1H NMR spectroscopy since the proton resonances in the labeled species are shifted upfield due to an isotopic chemical shift effect. The 1H-1H scalar coupling observed in both the 2H and 1H NMR spectra was used to assign definitively the resonances of labeled species. An increase in the intensity of natural abundance deuterium signal of water can be used to monitor pathways in which a deuteron is lost from the labeled metabolite. The steps in which label loss can occur are outlined, and the influence these processes have on the ability of 2H NMR spectroscopy to monitor metabolism are assessed.
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High resolution deuterium NMR studies of bacterial metabolism
International Nuclear Information System (INIS)
Aguayo, J.B.; Gamcsik, M.P.; Dick, J.D.
1988-01-01
High resolution deuterium NMR spectra were obtained from suspensions of five bacterial strains: Escherichia coli, Clostridium perfringens, Klebsiella pneumoniae, Proteus mirabilis, and Staphylococcus aureus. Deuterium-labeled D-glucose at C-1, C-2, and C-6 was used to monitor dynamically anaerobic metabolism. The flux of glucose through the various bacterial metabolic pathways could be determined by following the disappearance of glucose and the appearance of the major end products in the 2H NMR spectrum. The presence of both labeled and unlabeled metabolites could be detected using 1H NMR spectroscopy since the proton resonances in the labeled species are shifted upfield due to an isotopic chemical shift effect. The 1H-1H scalar coupling observed in both the 2H and 1H NMR spectra was used to assign definitively the resonances of labeled species. An increase in the intensity of natural abundance deuterium signal of water can be used to monitor pathways in which a deuteron is lost from the labeled metabolite. The steps in which label loss can occur are outlined, and the influence these processes have on the ability of 2H NMR spectroscopy to monitor metabolism are assessed
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Determination of solid fat content by NMR
International Nuclear Information System (INIS)
Kawada, Tsukasa; Kato, Chihiro; Suzuki, Kazuaki
1984-01-01
To establish a standard method for determing solid fat content, the NMR method was tested at six laboratories and the results were examined for collaboration. Two types of instruments, pulse NMR and wide-line NMR were used. Standard deviation in results at six laboratories was less than 1.5 for the step wise method, but more than 1.5 for the rapid method. The standard deviation in results at a single laboratory was much less than either of these cases. No significant difference could be observed in the values obtained using both instruments. Solid fat content values measured for a mixture of fully hydrogenated rapeseed and rapeseed oil agreed well with the percentage of solid by weight. (author)
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Knowns and unknowns in metabolomics identified by multidimensional NMR and hybrid MS/NMR methods
Energy Technology Data Exchange (ETDEWEB)
Bingol, Kerem; Brüschweiler, Rafael
2017-02-01
Metabolomics continues to make rapid progress through the development of new and better methods and their applications to gain insight into the metabolism of a wide range of different biological systems from a systems biology perspective. Customization of NMR databases and search tools allows the faster and more accurate identification of known metabolites, whereas the identification of unknowns, without a need for extensive purification, requires new strategies to integrate NMR with mass spectrometry, cheminformatics, and computational methods. For some applications, the use of covalent and non-covalent attachments in the form of labeled tags or nanoparticles can significantly reduce the complexity of these tasks.
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Crystallographically-based analysis of the NMR spectra of maghemite
International Nuclear Information System (INIS)
Spiers, K.M.; Cashion, J.D.
2012-01-01
All possible iron environments with respect to nearest neighbour vacancies in vacancy-ordered and vacancy-disordered maghemite have been evaluated and used as the foundation for a crystallographically-based analysis of the published NMR spectra of maghemite. The spectral components have been assigned to particular configurations and excellent agreement obtained in comparing predicted spectra with published spectra taken in applied magnetic fields. The broadness of the published NMR lines has been explained by calculations of the magnetic dipole fields at the various iron sites and consideration of the supertransferred hyperfine fields. - Highlights: ► Analysis of 57 Fe NMR of maghemite based on vacancy ordering and nearest neighbour vacancies. ► Assignment of NMR spectral components based on crystallographic analysis of unique iron sites. ► Strong agreement between predicted spectra and published spectra taken in applied magnetic fields. ► Maghemite NMR spectral broadening due to various iron sites and supertransferred hyperfine field.
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Application of Solution NMR Spectroscopy to Study Protein Dynamics
Directory of Open Access Journals (Sweden)
Christoph Göbl
2012-03-01
Full Text Available Recent advances in spectroscopic methods allow the identification of minute fluctuations in a protein structure. These dynamic properties have been identified as keys to some biological processes. The consequences of this structural flexibility can be far‑reaching and they add a new dimension to the structure-function relationship of biomolecules. Nuclear Magnetic Resonance (NMR spectroscopy allows the study of structure as well as dynamics of biomolecules in a very broad range of timescales at atomic level. A number of new NMR methods have been developed recently to allow the measurements of time scales and spatial fluctuations, which in turn provide the thermodynamics associated with the biological processes. Since NMR parameters reflect ensemble measurements, structural ensemble approaches in analyzing NMR data have also been developed. These new methods in some instances can even highlight previously hidden conformational features of the biomolecules. In this review we describe several solution NMR methods to study protein dynamics and discuss their impact on important biological processes.
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Development of a micro flow-through cell for high field NMR spectroscopy.
Energy Technology Data Exchange (ETDEWEB)
Alam, Todd Michael; McIntyre, Sarah K.
2011-05-01
A highly transportable micro flow-through detection cell for nuclear magnetic resonance (NMR) spectroscopy has been designed, fabricated and tested. This flow-through cell allows for the direct coupling between liquid chromatography (LC) and gel permeation chromatography (GPC) resulting in the possibility of hyphenated LC-NMR and GPC-NMR. The advantage of the present flow cell design is that it is independent and unconnected to the detection probe electronics, is compatible with existing commercial high resolution NMR probes, and as such can be easily implemented at any NMR facility. Two different volumes were fabricated corresponding to between {approx}3.8 and 10 {micro}L detection volume. Examples of the performance of the cell on different NMR instruments, and using different NMR detection probes were demonstrated.
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International Nuclear Information System (INIS)
Fossell, E.T.; Hall, F.M.; McDonagh, J.
1991-01-01
The authors have previously described the application of water-suppressed proton nuclear magnetic resonance (H-1 NMR) spectroscopy of plasma for detection of malignancy. Subsequently, hypertriglyceridemia has been identified as a source of false positive results. Here is described a confirmatory, adjunctive technique -analysis of the carbon-13 (C-13) NMR spectrum of plasma- which also identifies the presence of malignancy but is not sensitive to the plasma triglyceride level. Blinded plasma samples from 480 normal donors and 208 patients scheduled for breast biopsy were analyzed by water-suppressed H-1 and C-13 NMR spectroscopy. Triglyceride levels were also measured. Among the normal donors, there were 38 individuals with hypertriglyceridemia of whom 18 had results consistent with malignancy by H-1 NMR spectroscopy. However, the C-13 technique reduced the apparent H-1 false positive rate from 7.0 to 0.6 percent. Similarly, in the breast biopsy cohort, C-13 reduced the false positive rate from 2.8 to 0.9 percent. Furthermore, the accuracy of the combined H-1/C-13 test in this blinded study was greater than 96 percent in 208 patients studied. (author). 27 refs.; 5 figs.; 4 tabs
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NMR studies of the structure of glasses
International Nuclear Information System (INIS)
Bray, P.J.; Gravina, S.J.; Stallworth, P.E.; Szu, S.P.; Jianhui Zhong
1988-01-01
Earlier continuous wave (CW) NMR studies of chemical bonding and structure in glasses are summarized. Examples are given of this use of the quadrupolar interaction and chemical shift to obtain structural information. New NMR data and analyses are presented for alkali borate and gallate glasses. Extensions to other elements (e.g. molybdenum, lanthanum) are suggested. 44 refs. (author)
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Early history of NMR at Los Alamos
International Nuclear Information System (INIS)
Jackson, J.A.
1985-11-01
Nuclear magnetic resonance (NMR) spectroscopy has developed into an important research tool in chemistry. More recently, NMR imaging and in vivo spectroscopy promise to produce a revolution in medicine and biochemistry. Early experiments at Los Alamos led to DOE programs involving stable isotopes of importance to biology and to medicine. These events are briefly recounted. 2 refs
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Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines
Regehr, Eric V.; Laidre, Kristin L.; Akçakaya, H. Resit; Amstrup, Steven C.; Atwood, Todd C.; Lunn, Nicholas J.; Obbard, Martyn E.; Stern, Harry; Thiemann, Gregory W.; Wiig, Øystein
2016-01-01
Loss of Arctic sea ice owing to climate change is the primary threat to polar bears throughout their range. We evaluated the potential response of polar bears to sea-ice declines by (i) calculating generation length (GL) for the species, which determines the timeframe for conservation assessments; (ii) developing a standardized sea-ice metric representing important habitat; and (iii) using statistical models and computer simulation to project changes in the global population under three approaches relating polar bear abundance to sea ice. Mean GL was 11.5 years. Ice-covered days declined in all subpopulation areas during 1979–2014 (median −1.26 days year−1). The estimated probabilities that reductions in the mean global population size of polar bears will be greater than 30%, 50% and 80% over three generations (35–41 years) were 0.71 (range 0.20–0.95), 0.07 (range 0–0.35) and less than 0.01 (range 0–0.02), respectively. According to IUCN Red List reduction thresholds, which provide a common measure of extinction risk across taxa, these results are consistent with listing the species as vulnerable. Our findings support the potential for large declines in polar bear numbers owing to sea-ice loss, and highlight near-term uncertainty in statistical projections as well as the sensitivity of projections to different plausible assumptions.
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Conservation status of polar bears (Ursus maritimus) in relation to projected sea-ice declines.
Regehr, Eric V; Laidre, Kristin L; Akçakaya, H Resit; Amstrup, Steven C; Atwood, Todd C; Lunn, Nicholas J; Obbard, Martyn; Stern, Harry; Thiemann, Gregory W; Wiig, Øystein
2016-12-01
Loss of Arctic sea ice owing to climate change is the primary threat to polar bears throughout their range. We evaluated the potential response of polar bears to sea-ice declines by (i) calculating generation length (GL) for the species, which determines the timeframe for conservation assessments; (ii) developing a standardized sea-ice metric representing important habitat; and (iii) using statistical models and computer simulation to project changes in the global population under three approaches relating polar bear abundance to sea ice. Mean GL was 11.5 years. Ice-covered days declined in all subpopulation areas during 1979-2014 (median -1.26 days year -1 ). The estimated probabilities that reductions in the mean global population size of polar bears will be greater than 30%, 50% and 80% over three generations (35-41 years) were 0.71 (range 0.20-0.95), 0.07 (range 0-0.35) and less than 0.01 (range 0-0.02), respectively. According to IUCN Red List reduction thresholds, which provide a common measure of extinction risk across taxa, these results are consistent with listing the species as vulnerable. Our findings support the potential for large declines in polar bear numbers owing to sea-ice loss, and highlight near-term uncertainty in statistical projections as well as the sensitivity of projections to different plausible assumptions. © 2016 The Authors.
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Novel Method of Production Decline Analysis
Xie, Shan; Lan, Yifei; He, Lei; Jiao, Yang; Wu, Yong
2018-02-01
ARPS decline curves is the most commonly used in oil and gas field due to its minimal data requirements and ease application. And prediction of production decline which is based on ARPS analysis rely on known decline type. However, when coefficient index are very approximate under different decline type, it is difficult to directly recognize decline trend of matched curves. Due to difficulties above, based on simulation results of multi-factor response experiments, a new dynamic decline prediction model is introduced with using multiple linear regression of influence factors. First of all, according to study of effect factors of production decline, interaction experimental schemes are designed. Based on simulated results, annual decline rate is predicted by decline model. Moreover, the new method is applied in A gas filed of Ordos Basin as example to illustrate reliability. The result commit that the new model can directly predict decline tendency without needing recognize decline style. From arithmetic aspect, it also take advantage of high veracity. Finally, the new method improves the evaluation method of gas well production decline in low permeability gas reservoir, which also provides technical support for further understanding of tight gas field development laws.
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Optimization and practical implementation of ultrafast 2D NMR experiments
Energy Technology Data Exchange (ETDEWEB)
Queiroz Junior, Luiz H. K., E-mail: professorkeng@gmail.com [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Universidade Federal de Goias (UFGO), Goiania, GO (Brazil). Inst. de Quimica; Ferreira, Antonio G. [Universidade Federal de Sao Carlos (UFSC), SP (Brazil). Departamento de Quimica; Giraudeau, Patrick [Universite de Nantes (France). CNRS, Chimie et Interdisciplinarite: Synthese, Analyse, Modelisation
2013-09-01
Ultrafast 2D NMR is a powerful methodology that allows recording of a 2D NMR spectrum in a fraction of second. However, due to the numerous non-conventional parameters involved in this methodology its implementation is no trivial task. Here, an optimized experimental protocol is carefully described to ensure efficient implementation of ultrafast NMR. The ultrafast spectra resulting from this implementation are presented based on the example of two widely used 2D NMR experiments, COSY and HSQC, obtained in 0.2 s and 41 s, respectively. (author)
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NMR studies of multiphase flows II
Energy Technology Data Exchange (ETDEWEB)
Altobelli, S.A.; Caprihan, A.; Fukushima, E. [Lovelace Institutes, Albuquerque, NM (United States)] [and others
1995-12-31
NMR techniques for measurements of spatial distribution of material phase, velocity and velocity fluctuation are being developed and refined. Versions of these techniques which provide time average liquid fraction and fluid phase velocity have been applied to several concentrated suspension systems which will not be discussed extensively here. Technical developments required to further extend the use of NMR to the multi-phase flow arena and to provide measurements of previously unobtainable parameters are the focus of this report.
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Personality and Cognitive Decline in Older Adults: Data From a Longitudinal Sample and Meta-Analysis
Terracciano, Antonio; Stephan, Yannick; Sutin, Angelina R.
2016-01-01
Objectives: Personality traits are associated with risk of dementia; less is known about their association with the trajectory of cognitive functioning. This research examines the association between the 5 major dimensions of personality and cognitive function and decline in older adulthood and includes a meta-analysis of published studies. Method: Personality traits, objective and subjective memory, and cognitive status were collected in a large national sample (N = 13,987) with a 4-year follow-up period. For each trait, the meta-analysis pooled results from up to 5 prospective studies to examine personality and change in global cognition. Results: Higher Neuroticism was associated with worse performance on all cognitive measures and greater decline in memory, whereas higher Conscientiousness and Openness were associated with better memory performance concurrently and less decline over time. All traits were associated with subjective memory. Higher Conscientiousness and lower Extraversion were associated with better cognitive status and less decline. Although modest, these associations were generally larger than that of hypertension, diabetes, history of psychological treatment, obesity, smoking, and physical inactivity. The meta-analysis supported the association between Neuroticism and Conscientiousness and cognitive decline. Discussion: Personality is associated with cognitive decline in older adults, with effects comparable to established clinical and lifestyle risk factors. PMID:25583598
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{sup 1}H qNMR and chemometric analyses of urban wastewater
Energy Technology Data Exchange (ETDEWEB)
Alves Filho, Elenilson G.; Silva, Lorena M. A.; Venâncio, Tiago; Carneiro, Renato L.; Ferreira, Antonio G., E-mail: elenilson.godoy@yahoo.com.br [Universidade Federal de São Carlos (UFSCar), São Carlos, SP (Brazil). Departamento de Química; Sartori, Luci [Serviço Autônomo de Água e Esgoto de São Carlos (SAAE), São Carlos, SP (Brazil)
2015-07-01
The industrial development, urbanization and agriculture play a major role in the degradation of the global environmental. Thus, the wastewater treatments need to be monitored continuously to ensure efficient operation. This manuscript presents an application of {sup 1}H nuclear magnetic resonance (NMR) associated with chemometric and quantitative analyses to study the wastewater before and after the sewage treatment plant (STP). The concentration of compounds related to organic matter degradation ranged with treatment and seasonality. Anomalous discharges and the influence of storm water on the sewage composition were further identified. All the variations indicated that the employed procedure might be useful to enhance the effectiveness of STPs, plan prevention actions for equipment protection and preserve the environment. (author)
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Comparing pharmacophore models derived from crystallography and NMR ensembles
Ghanakota, Phani; Carlson, Heather A.
2017-11-01
NMR and X-ray crystallography are the two most widely used methods for determining protein structures. Our previous study examining NMR versus X-Ray sources of protein conformations showed improved performance with NMR structures when used in our Multiple Protein Structures (MPS) method for receptor-based pharmacophores (Damm, Carlson, J Am Chem Soc 129:8225-8235, 2007). However, that work was based on a single test case, HIV-1 protease, because of the rich data available for that system. New data for more systems are available now, which calls for further examination of the effect of different sources of protein conformations. The MPS technique was applied to Growth factor receptor bound protein 2 (Grb2), Src SH2 homology domain (Src-SH2), FK506-binding protein 1A (FKBP12), and Peroxisome proliferator-activated receptor-γ (PPAR-γ). Pharmacophore models from both crystal and NMR ensembles were able to discriminate between high-affinity, low-affinity, and decoy molecules. As we found in our original study, NMR models showed optimal performance when all elements were used. The crystal models had more pharmacophore elements compared to their NMR counterparts. The crystal-based models exhibited optimum performance only when pharmacophore elements were dropped. This supports our assertion that the higher flexibility in NMR ensembles helps focus the models on the most essential interactions with the protein. Our studies suggest that the "extra" pharmacophore elements seen at the periphery in X-ray models arise as a result of decreased protein flexibility and make very little contribution to model performance.
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Molecular dynamics simulations on PGLa using NMR orientational constraints
Energy Technology Data Exchange (ETDEWEB)
Sternberg, Ulrich, E-mail: ulrich.sternberg@partner.kit.edu; Witter, Raiker [Tallinn University of Technology, Technomedicum (Estonia)
2015-11-15
NMR data obtained by solid state NMR from anisotropic samples are used as orientational constraints in molecular dynamics simulations for determining the structure and dynamics of the PGLa peptide within a membrane environment. For the simulation the recently developed molecular dynamics with orientational constraints technique (MDOC) is used. This method introduces orientation dependent pseudo-forces into the COSMOS-NMR force field. Acting during a molecular dynamics simulation these forces drive molecular rotations, re-orientations and folding in such a way that the motional time-averages of the tensorial NMR properties are consistent with the experimentally measured NMR parameters. This MDOC strategy does not depend on the initial choice of atomic coordinates, and is in principle suitable for any flexible and mobile kind of molecule; and it is of course possible to account for flexible parts of peptides or their side-chains. MDOC has been applied to the antimicrobial peptide PGLa and a related dimer model. With these simulations it was possible to reproduce most NMR parameters within the experimental error bounds. The alignment, conformation and order parameters of the membrane-bound molecule and its dimer were directly derived with MDOC from the NMR data. Furthermore, this new approach yielded for the first time the distribution of segmental orientations with respect to the membrane and the order parameter tensors of the dimer systems. It was demonstrated the deuterium splittings measured at the peptide to lipid ratio of 1/50 are consistent with a membrane spanning orientation of the peptide.
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History of Tree Growth Declines Recorded in Old Trees at Two Sacred Sites in Northern China.
Li, Yan; Zhang, Qi-Bin
2017-01-01
Old forests are an important component in sacred sites, yet they are at risk of growth decline from ongoing global warming and increased human activities. Growth decline, characterized by chronic loss of tree vigor, is not a recent phenomenon. Knowledge of past occurrence of declines is useful for preparing conservation plans because it helps understand if present day forests are outside the natural range of variation in tree health. We report a dendroecological study of growth decline events in the past two centuries at two sacred sites, Hengshan and Wutaishan, in Shanxi province of northern China. Tree rings collected at both sites show distinct periods of declining growth evident as narrow rings. These occurred in the 1830s in both sites, in the 1920s in Wutaishan and in the 2000s in Hengshan. By comparing the pattern of grow declines at the two sites, we hypothesize that resistance of tree growth to external disturbances is forest size dependent, and increased human activity might be a factor additional to climatic droughts in causing the recent strong growth decline at Hengshan Park. Despite these past declines, the forests at both sites have high resilience to disturbances as evidenced by the ability of trees to recover their growth rates to levels comparable to the pre-decline period. Managers should consider reducing fragmentation and restoring natural habitat of old forests, especially in areas on dry sites.
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History of Tree Growth Declines Recorded in Old Trees at Two Sacred Sites in Northern China
Directory of Open Access Journals (Sweden)
Yan Li
2017-11-01
Full Text Available Old forests are an important component in sacred sites, yet they are at risk of growth decline from ongoing global warming and increased human activities. Growth decline, characterized by chronic loss of tree vigor, is not a recent phenomenon. Knowledge of past occurrence of declines is useful for preparing conservation plans because it helps understand if present day forests are outside the natural range of variation in tree health. We report a dendroecological study of growth decline events in the past two centuries at two sacred sites, Hengshan and Wutaishan, in Shanxi province of northern China. Tree rings collected at both sites show distinct periods of declining growth evident as narrow rings. These occurred in the 1830s in both sites, in the 1920s in Wutaishan and in the 2000s in Hengshan. By comparing the pattern of grow declines at the two sites, we hypothesize that resistance of tree growth to external disturbances is forest size dependent, and increased human activity might be a factor additional to climatic droughts in causing the recent strong growth decline at Hengshan Park. Despite these past declines, the forests at both sites have high resilience to disturbances as evidenced by the ability of trees to recover their growth rates to levels comparable to the pre-decline period. Managers should consider reducing fragmentation and restoring natural habitat of old forests, especially in areas on dry sites.
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observed by high pressure NMR and NQR
Indian Academy of Sciences (India)
Akogun, Hyogo 678-1297, Japan. ∗. Email: kohara@sci.himeji tech.ac.jp. Abstract. NMR and NQR studies on two interesting systems (URu2Si2, CeTIn5) were performed under high pressure. (1) URu2Si2: In the pressure range 3.0 to 8.3 kbar, we have observed new 29Si. NMR signals arising from the antiferromagnetic ...
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Deuterium NMR, induced and intrinsic cholesteric lyomesophases
International Nuclear Information System (INIS)
Alcantara, M.R.
1982-01-01
Induced and intrinsic cholesteric lyotropic mesophases were studied. Induced cholesteric lyomesophases based on potassium laurate (KL) system, with small amounts of cholesterol added, were studied by deuterium NMR and by polarizing microscopy. Order profiles obtained from deuterium NMR of KL perdenderated chains in both induced cholesteric and normal mesophases were compared. The intrinsic cholesteric lyotropic mesophases were based on the amphiphile potassium N-lauroyl serinate (KLNS) in the resolved levo form. The study of the type I intrinsic cholesteric mesophase was made by optical microscopy under polarized light and the type II intrinsic cholesteric lyomesophase was characterized by deuterium NMR. The new texture was explained by the use of the theory of disclinations developed for thermotropic liquid crystals, specially for cholesteric type. (M.J.C.) [pt
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Muscular pathology: echographic and NMR imaging aspects
International Nuclear Information System (INIS)
Pascal-Suisse, P.; Beaurain, P.; Mougniot, C.
1995-01-01
A comparison of echographic techniques and NMR imaging has been done for the diagnosis of muscular trauma and tumor pathologies. In traumatic pathology, the echographic analysis allows to determine the complete assessment of recent muscular injuries. NMR imaging can be used in granuloma or fibrous callosity appreciation and for the analysis of deep injury (muscles and muscles-tendon junctions) and of muscular aponeurosis. Echography must be used together with color coding Doppler technique in the diagnosis of tumor pathology and for the study of slow fluxes. The recently available energy Doppler technique seems to be powerful in the study of vascularization of small expansive formations, but their extension to adjacent bone or tissue can only be appreciated using NMR imaging. (J.S.)
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A comparative study of bone scintigraphy and NMR for vertebral diseases
International Nuclear Information System (INIS)
Nakatani, Mariko; Sekiya, Toru; Hata, Yuichi; Mori, Yutaka; Yasuda, Masanobu; Kawakami, Kenji; Tada, Sinpei
1985-01-01
A comparative study of NMR and bone scintigraphy was performed in vertebral disorders, and the significance of both modalities was evaluated. Twelve patients with various vertebral abnormalities including ten cases of vertebral metastases, one case of cervical caries and one case of Granular cell tumor of L3, were examined. In 4 patients, NMR showed abnormalities in the same regions as the bone scintigrams. In another 3 patients. NMR did not show the disorders reported on bone scintigrams. This may be due to the low NMR sensitivity to tiny infiltration of tumor cells in the bone marrow. In 3 out of the remaining 5 patients, NMR demonstrated abnormal findings, whilst the bone scintigrams were normal. Previous bone scintigrams in these patients before treatment had shown abnormal accumulation of activity in the region of abnormal NMR findings. This may be due to the fact that NMR detects the irreversible change of bone marrow, and bone scintigram demonstrates the turn over of bone minerals. This limited experience suggests that both madalities are complementary in the evaluation of vertebral abnormalities. (author)
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Boisbouvier, J; Albrand, J P; Blackledge, M; Jaquinod, M; Schweitz, H; Lazdunski, M; Marion, D
1998-01-01
The solution structure of mamba intestinal toxin 1 (MIT1), isolated from Dendroaspis polylepis polylepis venom, has been determined. This molecule is a cysteine-rich polypeptide exhibiting no recognised family membership. Resistance to MIT1 to classical specific endoproteases produced contradictory NMR and biochemical information concerning disulphide-bridge topology. We have used distance restraints allowing ambiguous partners between S atoms in combination with NMR-derived structural information, to correctly determine the disulphide-bridge topology. The resultant solution structure of MIT1, determined to a resolution of 0.5 A, reveals an unexpectedly similar global fold with respect to colipase, a protein involved in fatty acid digestion. Colipase exhibits an analogous resistance to endoprotease activity, indicating for the first time the possible topological origins of this biochemical property. The biochemical and structural homology permitted us to propose a mechanically related digestive function for MIT1 and provides novel information concerning snake venom protein evolution. Copyright 1998 Academic Press.
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NMR and domain wall mobility in intermetallic compounds
International Nuclear Information System (INIS)
Guimaraes, A.P.; Sampaio, L.C.; Cunha, S.F.; Alves, K.M.B.
1991-01-01
The technique of pulsed NMR can be used to study the distribution of hyperfine fields in a magnetic matrix. The dynamics of the domain walls are relevant to the generation of NMR signals. In the present study on the (R x Y 1-x ) Fe 2 intermetallic compounds, the reduction in the signals is associated to increased propagation fields. This indicates that a smaller domain wall mobility is at the origin of these effects. NMR spectra in this system show the importance of direct and indirect (i.e., mediated by Fe atoms) terms in the transferred hyperfine field. (author)
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ImatraNMR: Novel software for batch integration and analysis of quantitative NMR spectra
Mäkelä, A. V.; Heikkilä, O.; Kilpeläinen, I.; Heikkinen, S.
2011-08-01
Quantitative NMR spectroscopy is a useful and important tool for analysis of various mixtures. Recently, in addition of traditional quantitative 1D 1H and 13C NMR methods, a variety of pulse sequences aimed for quantitative or semiquantitative analysis have been developed. To obtain actual usable results from quantitative spectra, they must be processed and analyzed with suitable software. Currently, there are many processing packages available from spectrometer manufacturers and third party developers, and most of them are capable of analyzing and integration of quantitative spectra. However, they are mainly aimed for processing single or few spectra, and are slow and difficult to use when large numbers of spectra and signals are being analyzed, even when using pre-saved integration areas or custom scripting features. In this article, we present a novel software, ImatraNMR, designed for batch analysis of quantitative spectra. In addition to capability of analyzing large number of spectra, it provides results in text and CSV formats, allowing further data-analysis using spreadsheet programs or general analysis programs, such as Matlab. The software is written with Java, and thus it should run in any platform capable of providing Java Runtime Environment version 1.6 or newer, however, currently it has only been tested with Windows and Linux (Ubuntu 10.04). The software is free for non-commercial use, and is provided with source code upon request.
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Frontiers of NMR in Molecular Biology
Energy Technology Data Exchange (ETDEWEB)
NONE
1999-08-25
NMR spectroscopy is expanding the horizons of structural biology by determining the structures and describing the dynamics of blobular proteins in aqueous solution, as well as other classes of proteins including membrane proteins and the polypeptides that form the aggregates diagnostic of prion and amyloid diseases. Significant results are also emerging on DNA and RNA oligomers and their complexes with proteins. This meeting focused attention on key structural questions emanating from molecular biology and how NMR spectroscopy can be used to answer them.
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Touch NMR: An NMR Data Processing Application for the iPad
Li, Qiyue; Chen, Zhiwei; Yan, Zhiping; Wang, Cheng; Chen, Zhong
2014-01-01
Nuclear magnetic resonance (NMR) spectroscopy has become one of the most powerful technologies to aid research in numerous scientific disciplines. With the development of consumer electronics, mobile devices have played increasingly important roles in our daily life. However, there is currently no application available for mobile devices able to…
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Directory of Open Access Journals (Sweden)
Brdar Milan M.
2002-01-01
Full Text Available In the article author is about to maintain that discussion on regionalization asks for contextualisation within the currents of actual geopolitics, on the one hand, and wider process of globalisation and unification, on the other. In keeping with this, author in the first part deals with globalizing integrative processes with special attention played to the problem of nation-state survival. Point of analysis is given in the ambivalence of sovereignty: the very concept becomes outdated on the local level, but by the same token it is fully affirmed on the global level. On the global level we are encountered with revival of the classical concept of sovereignty. Problem of regionalization, in the second part of the article, is reconsidered as a phenomenon that is taking place between those two currents. Author maintains two related theses. First, designs of the regionalization less dependent of the authority of given state for they fall under the jurisdiction of global superpower and becomes dependant of its geostrategic planes and political demands. Second, that main reasons for Democratic Opposition of Serbia to work in favor of regionalization as a synonym for democracy is in lack of solid democratic reform and need to entrench itself in the precomposed structure of social and economic power. In this context one could forsake that we in Serbia are confronted with bright prospects of democracy at the cost of the 'hollowing out' of the state as main guarantee of it.
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Globalization and deficit and limitations of global governance
Directory of Open Access Journals (Sweden)
Stojanović Stanislav
2016-01-01
Full Text Available Character and dynamics of relationships in international politics, in which the stronger return to real politics content in the functioning of the foreign policy of the great powers, unequivocally affirms that globalization does not work to its declining power that is less credible design concept of modern world society. The global financial collapse that hit the world in 2008 is a convincing indication that most of the globalization is discredited. The belief in one humanity is becoming a less desirable concept. At the same time, with the increase in global issues that require solving, there are numerous human activities that involve unique or international regulation. The world is increasingly one homeostatic system of interdependent parts of a continent where many aspects of the borders between countries are difficult or even impossible to sustain. Hence the importance of global factors, some of which will fully depend on the articulation of individual and community life of people in the future, stressing the importance of the issue of joint management to ensure global peace and security and promote the prosperity around the world in a universally acceptable and effective way. Therefore, the demonstrated substantial shortcomings of global governance of the world, although they discourage belief in humanity, did not reduce the objective need for global access to many amenities of modern human existence. Many aspects of security, ranging from the security of the individual to the energy and environmental security in modern conditions are not conceivable without international access. However, global security management has been associated with numerous limitations and challenges.
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NMR analog of Bell's inequalities violation test
International Nuclear Information System (INIS)
Souza, A M; Oliveira, I S; Sarthour, R S; Magalhaes, A; Teles, J; Azevedo, E R de; Bonagamba, T J
2008-01-01
In this paper, we present an analog of Bell's inequalities violation test for N qubits to be performed in a nuclear magnetic resonance (NMR) quantum computer. This can be used to simulate or predict the results for different Bell's inequality tests, with distinct configurations and a larger number of qubits. To demonstrate our scheme, we implemented a simulation of the violation of the Clauser, Horne, Shimony and Holt (CHSH) inequality using a two-qubit NMR system and compared the results to those of a photon experiment. The experimental results are well described by the quantum mechanics theory and a local realistic hidden variables model (LRHVM) that was specifically developed for NMR. That is why we refer to this experiment as a simulation of Bell's inequality violation. Our result shows explicitly how the two theories can be compatible with each other due to the detection loophole. In the last part of this work, we discuss the possibility of testing some fundamental features of quantum mechanics using NMR with highly polarized spins, where a strong discrepancy between quantum mechanics and hidden variables models can be expected
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Proton NMR imaging in experimental ischemic infarction
International Nuclear Information System (INIS)
Buonanno, F.S.; Pykett, I.L.; Brady, T.J.; Vielma, J.; Burt, C.T.; Goldman, M.R.; Hinshaw, W.S.; Pohost, G.M.; Kistler, J.P.
1983-01-01
Proton nuclear magnetic resonance (NMR) images depict the distribution and concentration of mobile protons modified by the relaxation times T1 and T2. Using the steady-state-free-precession (SSFP) technique, serial coronal images were obtained sequentially over time in laboratory animals with experimental ischemic infarction. Image changes were evident as early as 2 hours after carotid artery ligation, and corresponded to areas of ischemic infarction noted pathologically. Resulting SSFP images in experimental stroke are contrasted to inversion-recovery NMR images in an illustrative patient with established cerebral infarction. Bulk T1 and T2 measurements were made in vitro in three groups of gerbils: normal, those with clinical evidence of infarction, and those clinically normal after carotid ligature. Infarcted hemispheres had significantly prolonged T1 and T2 (1.47 +/- .12 sec, 76.0 +/- 9.0 msec, respectively) when compared to the contralateral hemisphere (T1 . 1.28 +/- .05 sec, T2 . 58.7 +/- 3.9 msec) or to the other two groups. These data suggest that changes in NMR parameters occur and can be detected by NMR imaging as early as two hours after carotid artery ligation
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Remote tuning of NMR probe circuits.
Kodibagkar, V D; Conradi, M S
2000-05-01
There are many circumstances in which the probe tuning adjustments cannot be located near the rf NMR coil. These may occur in high-temperature NMR, low-temperature NMR, and in the use of magnets with small diameter access bores. We address here circuitry for connecting a fixed-tuned probe circuit by a transmission line to a remotely located tuning network. In particular, the bandwidth over which the probe may be remotely tuned while keeping the losses in the transmission line acceptably low is considered. The results show that for all resonant circuit geometries (series, parallel, series-parallel), overcoupling of the line to the tuned circuit is key to obtaining a large tuning bandwidth. At equivalent extents of overcoupling, all resonant circuit geometries have nearly equal remote tuning bandwidths. Particularly for the case of low-loss transmission line, the tuning bandwidth can be many times the tuned circuit's bandwidth, f(o)/Q. Copyright 2000 Academic Press.
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NMR Characterization of Flavanone Naringenin 7-O-Glycoside Diastereomer
Directory of Open Access Journals (Sweden)
SUN Li-juan
2017-12-01
Full Text Available To discriminate R and S flavanone glycoside using NMR, the mixture of R and S naringenin 7-O-glycoside was first isolated from Gleditsia sinensis. 1H and 13C NMR data of the mixture were recorded with 1H NMR, 13C NMR, 1H-1H COSY, 1H-13C HSQC and 1H-13C HMBC in DMSO-d6 solution. The two diastereomers were then separated with chiral chromatographic isolation, with their absolute configurations determined by circular dichroism. To avoid the disturbance of protons from glucose residues to dihydroflavonoid, 1H NMR spectra were acquired for pure R and S naringenin 7-O-glycoside and their mixture in CD3CN. The two diastereomers showed the largest proton chemical shift differences at the end group of glucose residue (H-1" with a chemical shift difference of 9.4 Hz. The OH-5 proton showed a chemical shift difference of 5.8 Hz. The chemical shift of the three protons on ring C were all influenced by configuration.
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Time domain NMR evaluation of poly(vinyl alcohol) xerogels
Energy Technology Data Exchange (ETDEWEB)
Rodrigues, Elton Jorge da Rocha; Cavalcante, Maxwell de Paula; Tavares, Maria Ines Bruno, E-mail: mibt@ima.ufrj.br [Universidade Federal do Rio de Janeiro (IMA/UFRJ), Rio de Janeiro, RJ (Brazil). Centro de Tecnologia. Instituto de Macromoleculas Professora Eloisa Mano
2016-05-15
Poly(vinyl alcohol) (PVA)-based chemically cross-linked xerogels, both neat and loaded with nanoparticulate hydrophilic silica (SiO{sub 2}), were obtained and characterized mainly through time domain NMR experiments (TD-NMR). Fourier-transform infrared (FT-IR) and wide angle X-ray diffraction (WAXD) analyses were employed as secondary methods. TD-NMR, through the interpretation of the spin-lattice relaxation constant values and related information, showed both cross-linking and nanoparticle influences on PVA matrix. SiO{sub 2} does not interact chemically with the PVA chains, but has effect on its molecular mobility, as investigated via TD-NMR. Apparent energy of activation, spin-lattice time constant and size of spin domains in the sample have almost linear dependence with the degree of cross-linking of the PVA and are affected by the addition of SiO{sub 2}. These three parameters were derived from a single set of TD-NMR experiments, which demonstrates the versatility of the technique for characterization of inorganic-organic hybrid xerogels, an important class of materials. (author)
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The GNAT: A new tool for processing NMR data.
Castañar, Laura; Poggetto, Guilherme Dal; Colbourne, Adam A; Morris, Gareth A; Nilsson, Mathias
2018-06-01
The GNAT (General NMR Analysis Toolbox) is a free and open-source software package for processing, visualising, and analysing NMR data. It supersedes the popular DOSY Toolbox, which has a narrower focus on diffusion NMR. Data import of most common formats from the major NMR platforms is supported, as well as a GNAT generic format. Key basic processing of NMR data (e.g., Fourier transformation, baseline correction, and phasing) is catered for within the program, as well as more advanced techniques (e.g., reference deconvolution and pure shift FID reconstruction). Analysis tools include DOSY and SCORE for diffusion data, ROSY T 1 /T 2 estimation for relaxation data, and PARAFAC for multilinear analysis. The GNAT is written for the MATLAB® language and comes with a user-friendly graphical user interface. The standard version is intended to run with a MATLAB installation, but completely free-standing compiled versions for Windows, Mac, and Linux are also freely available. © 2018 The Authors Magnetic Resonance in Chemistry Published by John Wiley & Sons Ltd.
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Applications of NMR to studies of tissue metabolism
International Nuclear Information System (INIS)
Avison, M.J.; Hetherington, H.P.; Shulman, R.G.
1986-01-01
From its beginnings as a tool for the elucidation of biochemical pathways and bioenergetic status in unicellular organisms, the field of NMR studie in vivo has grown to encompass not only the study of isolated perfused organs, but also the study of various aspects of the biochemistry, physiology, and pathophysiology of these same organs in the intact animal. In recent years several groups have begun to extend the techniques developed in animals to the study of clinically relevant conditions in humans. A comprehensive review of all areas of NMR studies in vivo would be either unacceptably long or very superficial. For this reason the authors have restricted this review to studies published since 1980, except where an earlier study is particularly relevant to the topic under discussion. Furthermore, they have concentrated on areas that have been extending the scope of NMR in vivo. One specific omission is review of NMR studies of tumors, since a comprehensive review has recently appeared
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International Nuclear Information System (INIS)
Kobayashi, Naohiro; Iwahara, Junji; Koshiba, Seizo; Tomizawa, Tadashi; Tochio, Naoya; Guentert, Peter; Kigawa, Takanori; Yokoyama, Shigeyuki
2007-01-01
The recent expansion of structural genomics has increased the demands for quick and accurate protein structure determination by NMR spectroscopy. The conventional strategy without an automated protocol can no longer satisfy the needs of high-throughput application to a large number of proteins, with each data set including many NMR spectra, chemical shifts, NOE assignments, and calculated structures. We have developed the new software KUJIRA, a package of integrated modules for the systematic and interactive analysis of NMR data, which is designed to reduce the tediousness of organizing and manipulating a large number of NMR data sets. In combination with CYANA, the program for automated NOE assignment and structure determination, we have established a robust and highly optimized strategy for comprehensive protein structure analysis. An application of KUJIRA in accordance with our new strategy was carried out by a non-expert in NMR structure analysis, demonstrating that the accurate assignment of the chemical shifts and a high-quality structure of a small protein can be completed in a few weeks. The high completeness of the chemical shift assignment and the NOE assignment achieved by the systematic analysis using KUJIRA and CYANA led, in practice, to increased reliability of the determined structure
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NMR study of hyper-polarized 129Xe and applications to liquid-phase NMR experiments
International Nuclear Information System (INIS)
Marion, D.
2008-07-01
In liquid samples where both nuclear polarization and spin density are strong, the magnetization dynamics, which can be analysed by NMR (nuclear magnetic resonance) methods, is deeply influenced by the internal couplings induced by local dipolar fields. The present thesis describes some of the many consequences associated to the presence in the sample of concentrated xenon hyper-polarized by an optical pumping process. First, we deal with the induced modifications in frequency and line width of the proton and xenon spectra, then we present the results of SPIDER, a coherent polarization transfer experiment designed to enhance the polarization of protons, in order to increase their NMR signal level. A third part is dedicated to the description of the apparition of repeated chaotic maser emissions by un unstable xenon magnetization coupled to the detection coil tuned at the xenon Larmor frequency (here 138 MHz). In the last part, we present a new method allowing a better tuning of any NMR detection probe and resulting in sensible gains in terms of sensitivity and signal shaping. Finally, we conclude with a partial questioning of the classical relaxation theory in the specific field of highly polarized and concentrated spin systems in a liquid phase. (author)
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Biomarker clusters are differentially associated with longitudinal cognitive decline in late midlife
Racine, Annie M.; Koscik, Rebecca L.; Berman, Sara E.; Nicholas, Christopher R.; Clark, Lindsay R.; Okonkwo, Ozioma C.; Rowley, Howard A.; Asthana, Sanjay; Bendlin, Barbara B.; Blennow, Kaj; Zetterberg, Henrik; Gleason, Carey E.; Carlsson, Cynthia M.
2016-01-01
The ability to detect preclinical Alzheimer’s disease is of great importance, as this stage of the Alzheimer’s continuum is believed to provide a key window for intervention and prevention. As Alzheimer’s disease is characterized by multiple pathological changes, a biomarker panel reflecting co-occurring pathology will likely be most useful for early detection. Towards this end, 175 late middle-aged participants (mean age 55.9 ± 5.7 years at first cognitive assessment, 70% female) were recruited from two longitudinally followed cohorts to undergo magnetic resonance imaging and lumbar puncture. Cluster analysis was used to group individuals based on biomarkers of amyloid pathology (cerebrospinal fluid amyloid-β42/amyloid-β40 assay levels), magnetic resonance imaging-derived measures of neurodegeneration/atrophy (cerebrospinal fluid-to-brain volume ratio, and hippocampal volume), neurofibrillary tangles (cerebrospinal fluid phosphorylated tau181 assay levels), and a brain-based marker of vascular risk (total white matter hyperintensity lesion volume). Four biomarker clusters emerged consistent with preclinical features of (i) Alzheimer’s disease; (ii) mixed Alzheimer’s disease and vascular aetiology; (iii) suspected non-Alzheimer’s disease aetiology; and (iv) healthy ageing. Cognitive decline was then analysed between clusters using longitudinal assessments of episodic memory, semantic memory, executive function, and global cognitive function with linear mixed effects modelling. Cluster 1 exhibited a higher intercept and greater rates of decline on tests of episodic memory. Cluster 2 had a lower intercept on a test of semantic memory and both Cluster 2 and Cluster 3 had steeper rates of decline on a test of global cognition. Additional analyses on Cluster 3, which had the smallest hippocampal volume, suggest that its biomarker profile is more likely due to hippocampal vulnerability and not to detectable specific volume loss exceeding the rate of normal
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Protein folding on the ribosome studied using NMR spectroscopy
Waudby, Christopher A.; Launay, Hélène; Cabrita, Lisa D.; Christodoulou, John
2013-01-01
NMR spectroscopy is a powerful tool for the investigation of protein folding and misfolding, providing a characterization of molecular structure, dynamics and exchange processes, across a very wide range of timescales and with near atomic resolution. In recent years NMR methods have also been developed to study protein folding as it might occur within the cell, in a de novo manner, by observing the folding of nascent polypeptides in the process of emerging from the ribosome during synthesis. Despite the 2.3 MDa molecular weight of the bacterial 70S ribosome, many nascent polypeptides, and some ribosomal proteins, have sufficient local flexibility that sharp resonances may be observed in solution-state NMR spectra. In providing information on dynamic regions of the structure, NMR spectroscopy is therefore highly complementary to alternative methods such as X-ray crystallography and cryo-electron microscopy, which have successfully characterized the rigid core of the ribosome particle. However, the low working concentrations and limited sample stability associated with ribosome–nascent chain complexes means that such studies still present significant technical challenges to the NMR spectroscopist. This review will discuss the progress that has been made in this area, surveying all NMR studies that have been published to date, and with a particular focus on strategies for improving experimental sensitivity. PMID:24083462
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Advances in solid-state NMR of cellulose.
Foston, Marcus
2014-06-01
Nuclear magnetic resonance (NMR) spectroscopy is a well-established analytical and enabling technology in biofuel research. Over the past few decades, lignocellulosic biomass and its conversion to supplement or displace non-renewable feedstocks has attracted increasing interest. The application of solid-state NMR spectroscopy has long been seen as an important tool in the study of cellulose and lignocellulose structure, biosynthesis, and deconstruction, especially considering the limited number of effective solvent systems and the significance of plant cell wall three-dimensional microstructure and component interaction to conversion yield and rate profiles. This article reviews common and recent applications of solid-state NMR spectroscopy methods that provide insight into the structural and dynamic processes of cellulose that control bulk properties and biofuel conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.
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UTOPIA NMR: activating unexploited magnetization using interleaved low-gamma detection
Energy Technology Data Exchange (ETDEWEB)
Viegas, Aldino; Viennet, Thibault [Heinrich-Heine-University, Institute of Physical Biology (Germany); Yu, Tsyr-Yan [Academia Sinica, Institute of Atomic and Molecular Sciences (China); Schumann, Frank [Bruker BioSpin GmbH (Switzerland); Bermel, Wolfgang [Bruker BioSpin GmbH (Germany); Wagner, Gerhard [Harvard Medical School, Department of Biological Chemistry and Molecular Pharmacology (United States); Etzkorn, Manuel, E-mail: manuel.etzkorn@hhu.de [Heinrich-Heine-University, Institute of Physical Biology (Germany)
2016-01-15
A growing number of nuclear magnetic resonance (NMR) spectroscopic studies are impaired by the limited information content provided by the standard set of experiments conventionally recorded. This is particularly true for studies of challenging biological systems including large, unstructured, membrane-embedded and/or paramagnetic proteins. Here we introduce the concept of unified time-optimized interleaved acquisition NMR (UTOPIA-NMR) for the unified acquisition of standard high-γ (e.g. {sup 1}H) and low-γ (e.g. {sup 13}C) detected experiments using a single receiver. Our aim is to activate the high level of polarization and information content distributed on low-γ nuclei without disturbing conventional magnetization transfer pathways. We show that using UTOPIA-NMR we are able to recover nearly all of the normally non-used magnetization without disturbing the standard experiments. In other words, additional spectra, that can significantly increase the NMR insights, are obtained for free. While we anticipate a broad range of possible applications we demonstrate for the soluble protein Bcl-x{sub L} (ca. 21 kDa) and for OmpX in nanodiscs (ca. 160 kDa) that UTOPIA-NMR is particularly useful for challenging protein systems including perdeuterated (membrane) proteins.
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UTOPIA NMR: activating unexploited magnetization using interleaved low-gamma detection
International Nuclear Information System (INIS)
Viegas, Aldino; Viennet, Thibault; Yu, Tsyr-Yan; Schumann, Frank; Bermel, Wolfgang; Wagner, Gerhard; Etzkorn, Manuel
2016-01-01
A growing number of nuclear magnetic resonance (NMR) spectroscopic studies are impaired by the limited information content provided by the standard set of experiments conventionally recorded. This is particularly true for studies of challenging biological systems including large, unstructured, membrane-embedded and/or paramagnetic proteins. Here we introduce the concept of unified time-optimized interleaved acquisition NMR (UTOPIA-NMR) for the unified acquisition of standard high-γ (e.g. 1 H) and low-γ (e.g. 13 C) detected experiments using a single receiver. Our aim is to activate the high level of polarization and information content distributed on low-γ nuclei without disturbing conventional magnetization transfer pathways. We show that using UTOPIA-NMR we are able to recover nearly all of the normally non-used magnetization without disturbing the standard experiments. In other words, additional spectra, that can significantly increase the NMR insights, are obtained for free. While we anticipate a broad range of possible applications we demonstrate for the soluble protein Bcl-x L (ca. 21 kDa) and for OmpX in nanodiscs (ca. 160 kDa) that UTOPIA-NMR is particularly useful for challenging protein systems including perdeuterated (membrane) proteins
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UTOPIA NMR: activating unexploited magnetization using interleaved low-gamma detection.
Viegas, Aldino; Viennet, Thibault; Yu, Tsyr-Yan; Schumann, Frank; Bermel, Wolfgang; Wagner, Gerhard; Etzkorn, Manuel
2016-01-01
A growing number of nuclear magnetic resonance (NMR) spectroscopic studies are impaired by the limited information content provided by the standard set of experiments conventionally recorded. This is particularly true for studies of challenging biological systems including large, unstructured, membrane-embedded and/or paramagnetic proteins. Here we introduce the concept of unified time-optimized interleaved acquisition NMR (UTOPIA-NMR) for the unified acquisition of standard high-γ (e.g. (1)H) and low-γ (e.g. (13)C) detected experiments using a single receiver. Our aim is to activate the high level of polarization and information content distributed on low-γ nuclei without disturbing conventional magnetization transfer pathways. We show that using UTOPIA-NMR we are able to recover nearly all of the normally non-used magnetization without disturbing the standard experiments. In other words, additional spectra, that can significantly increase the NMR insights, are obtained for free. While we anticipate a broad range of possible applications we demonstrate for the soluble protein Bcl-xL (ca. 21 kDa) and for OmpX in nanodiscs (ca. 160 kDa) that UTOPIA-NMR is particularly useful for challenging protein systems including perdeuterated (membrane) proteins.
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In-cell NMR spectroscopy of proteins inside Xenopus laevis oocytes
International Nuclear Information System (INIS)
Sakai, Tomomi; Tochio, Hidehito; Tenno, Takeshi; Ito, Yutaka; Kokubo, Tetsuro; Hiroaki, Hidekazu; Shirakawa, Masahiro
2006-01-01
In-cell NMR is an application of solution NMR that enables the investigation of protein conformations inside living cells. We have measured in-cell NMR spectra in oocytes from the African clawed frog Xenopus laevis. 15 N-labeled ubiquitin, its derivatives and calmodulin were injected into Xenopus oocytes and two-dimensional 1 H- 15 N correlation spectra of the proteins were obtained. While the spectrum of wild-type ubiquitin in oocytes had rather fewer cross-peaks compared to its in vitro spectrum, ubiquitin derivatives that are presumably unable to bind to ubiquitin-interacting proteins gave a markedly larger number of cross-peaks. This observation suggests that protein-protein interactions between ubiquitin and ubiquitin-interacting proteins may cause NMR signal broadening, and hence spoil the quality of the in-cell HSQC spectra. In addition, we observed the maturation of ubiquitin precursor derivative in living oocytes using the in-cell NMR technique. This process was partly inhibited by pre-addition of ubiquitin aldehyde, a specific inhibitor for ubiquitin C-terminal hydrolase (UCH). Our work demonstrates the potential usefulness of in-cell NMR with Xenopus oocytes for the investigation of protein conformations and functions under intracellular environmental conditions
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Molecular dynamics computer simulations based on NMR data
International Nuclear Information System (INIS)
Vlieg, J. de.
1989-01-01
In the work described in this thesis atom-atom distance information obtained from two-dimensional cuclear magnetic resonance is combined with molecular dynamics simulaitons. The simulation is used to improve the accuracy of a structure model constructed on the basis of NMR data. During the MD refinement the crude NMR structure is simultaneously optimized with respect to the atomic interaction function and to the set of atom-atom distances or other NMR information. This means that insufficient experimental data is completed with theoretical knowledge and the combination will lead to more reliable structures than would be obtained from one technique alone. (author). 191 refs.; 17 figs.; 12 schemes; 22 tabs
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Factors driving the global decline of cycad diversity.
Mankga, Ledile T; Yessoufou, Kowiyou
2017-07-01
Mounting evidence indicates that we are witnessing the sixth mass extinction period. Given the important goods and services biodiversity delivers to humans, there is a need for a continued commitment to investigate what pre-disposes some taxa to greater risk of extinction. Here, we investigate this question using a phylogenetic comparative method and fitting a cumulative link mixed effect model on biological, ecological and evolutionary data of cycads, the most threatened lineage in the plant kingdom. We identified nine groups of threats to cycads, with habitat loss, over-collection, fire and reproduction failure being the most prominent, but only four of these threats (habitat loss, over-collection, medicinal uses and reproduction failure) clustered on the cycad tree of life. This clustering suggests that closely related species may be exposed to similar threats, perhaps because of geographic regionalization of cycad genera. Nonetheless, the diversity of threats and several variables linked to the biology and ecology of cycads correlate with extinction risk (e.g. altitude, height, diameter, geographic range), and different variables seem to be linked to different IUCN status of cycads. Although their predictive power is generally extinction risk in cycads and, since most threats that we identified as drivers of extinction risk of cycads are anthropogenically mediated, we recommend stronger legislation to regulate human-cycad interactions and the commitment of all governments globally to implement this regulation.
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Parallels in amphibian and bat declines from pathogenic fungi.
Eskew, Evan A; Todd, Brian D
2013-03-01
Pathogenic fungi have substantial effects on global biodiversity, and 2 emerging pathogenic species-the chytridiomycete Batrachochytrium dendrobatidis, which causes chytridiomycosis in amphibians, and the ascomycete Geomyces destructans, which causes white-nose syndrome in hibernating bats-are implicated in the widespread decline of their vertebrate hosts. We synthesized current knowledge for chytridiomycosis and white-nose syndrome regarding disease emergence, environmental reservoirs, life history characteristics of the host, and host-pathogen interactions. We found striking similarities between these aspects of chytridiomycosis and white-nose syndrome, and the research that we review and propose should help guide management of future emerging fungal diseases.
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DEFF Research Database (Denmark)
Van Den Berg, Henk; Manuweera, Gamini; Konradsen, Flemming
2017-01-01
over the period 2001-2014. Results: Available data on global production of DDT showed a 32% decline over the reporting period, from 5144 to 3491 metric tons of active ingredient p.a. Similarly, global use of DDT, for control of malaria and leishmaniasis, showed a 30% decline over the period 2001...
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Piovia-Scott, Jonah; Pope, Karen; Worth, S Joy; Rosenblum, Erica Bree; Poorten, Thomas; Refsnider, Jeanine; Rollins-Smith, Louise A; Reinert, Laura K; Wells, Heather L; Rejmanek, Dan; Lawler, Sharon; Foley, Janet
2015-07-01
The fungal pathogen Batrachochytrium dendrobatidis (Bd) has caused declines and extinctions in amphibians worldwide, and there is increasing evidence that some strains of this pathogen are more virulent than others. While a number of putative virulence factors have been identified, few studies link these factors to specific epizootic events. We documented a dramatic decline in juvenile frogs in a Bd-infected population of Cascades frogs (Rana cascadae) in the mountains of northern California and used a laboratory experiment to show that Bd isolated in the midst of this decline induced higher mortality than Bd isolated from a more stable population of the same species of frog. This highly virulent Bd isolate was more toxic to immune cells and attained higher density in liquid culture than comparable isolates. Genomic analyses revealed that this isolate is nested within the global panzootic lineage and exhibited unusual genomic patterns, including increased copy numbers of many chromosomal segments. This study integrates data from multiple sources to suggest specific phenotypic and genomic characteristics of the pathogen that may be linked to disease-related declines.
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Indian Academy of Sciences (India)
Unknown
2005-01-03
Jan 3, 2005 ... covering all the systems, so far discovered.5,7,8,12. With the increasing ... Structural investigations on proteins by NMR are, currently ... rapid analysis of unfolded proteins. ...... and hence help in design of drugs against them.
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The effects of global climate change on fish and wildlife resources
International Nuclear Information System (INIS)
LaRose, E.T.
1991-01-01
Climate models predict a global temperature rise of 3±1 degree C, a sea level rise of 0.5-1.0 m, increased frequency of extreme events, and possible doubling of ultraviolet B radiation by 2050. A significant decrease in precipitation will have the most important effect on fish and wildlife in the Great Plains region. Temperature change in the Great Plains region is likely to exceed the global average increase, due to lack of ocean buffering. Human competition for dwindling water resources is likely to exacerbate the impact on wildlife. Wetlands and waterfowl will be the most severely impacted groups on the Plains. The diversity of aquatic invertebrates is expected to decline, due to loss of brackish wetlands. A net decline in population of fish and amphibians is expected, due to the reduction in hydrologic regimes outweighing any temperature increase benefits. Loss of old growth, climax, and late successional stages is expected to be particularly severe. Rapid global climate change is expected to lead to a higher extinction rate. Effectiveness of existing protected areas is expected to decline
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Tritiation methods and tritium NMR spectroscopy
International Nuclear Information System (INIS)
Jaiswal, D.K.; Morimoto, H.; Salijoughian, M.; Williams, P.G.
1991-09-01
We have used a simple process for the production of highly tritiated water and characterized the product species by 1 H and 3 H NMR spectroscopy. The water is readily manipulated and used in subsequent reactions either as T 2 O, CH 3 COOT or CF 3 COOT. Development of tritiated diimide has progressed to the point where cis-hydrogenated products at 1-20 Ci/mmole S.A. are possible. Tri-n-butyl tin tritide has been produced at >95% tritium content and well characterized by multinuclear NMR techniques. 27 refs., 3 figs
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Citation rate and perceived subject bias in the amphibian-decline literature.
Ohmer, Michel E; Bishop, Phillip J
2011-02-01
As a result of global declines in amphibian populations, interest in the conservation of amphibians has grown. This growth has been fueled partially by the recent discovery of other potential causes of declines, including chytridiomycosis (the amphibian chytrid, an infectious disease) and climate change. It has been proposed that researchers have shifted their focus to these novel stressors and that other threats to amphibians, such as habitat loss, are not being studied in proportion to their potential effects. We tested the validity of this proposal by reviewing the literature on amphibian declines, categorizing the primary topic of articles within this literature (e.g., habitat loss or UV-B radiation) and comparing citation rates among articles on these topics and impact factors of journals in which the articles were published. From 1990 to 2009, the proportion of papers on habitat loss remained fairly constant, and although the number of papers on chytridiomycosis increased after the disease was described in 1998, the number of published papers on amphibian declines also increased. Nevertheless, papers on chytridiomycosis were more highly cited than papers not on chytridiomycosis and were published in journals with higher impact factors on average, which may indicate this research topic is more popular in the literature. Our results were not consistent with a shift in the research agenda on amphibians. We believe the perception of such a shift has been supported by the higher citation rates of papers on chytridiomycosis. ©2010 Society for Conservation Biology.
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Structure determination of helical filaments by solid-state NMR spectroscopy
Ahmed, Mumdooh; Spehr, Johannes; König, Renate; Lünsdorf, Heinrich; Rand, Ulfert; Lührs, Thorsten; Ritter, Christiane
2016-01-01
The controlled formation of filamentous protein complexes plays a crucial role in many biological systems and represents an emerging paradigm in signal transduction. The mitochondrial antiviral signaling protein (MAVS) is a central signal transduction hub in innate immunity that is activated by a receptor-induced conversion into helical superstructures (filaments) assembled from its globular caspase activation and recruitment domain. Solid-state NMR (ssNMR) spectroscopy has become one of the most powerful techniques for atomic resolution structures of protein fibrils. However, for helical filaments, the determination of the correct symmetry parameters has remained a significant hurdle for any structural technique and could thus far not be precisely derived from ssNMR data. Here, we solved the atomic resolution structure of helical MAVSCARD filaments exclusively from ssNMR data. We present a generally applicable approach that systematically explores the helical symmetry space by efficient modeling of the helical structure restrained by interprotomer ssNMR distance restraints. Together with classical automated NMR structure calculation, this allowed us to faithfully determine the symmetry that defines the entire assembly. To validate our structure, we probed the protomer arrangement by solvent paramagnetic resonance enhancement, analysis of chemical shift differences relative to the solution NMR structure of the monomer, and mutagenesis. We provide detailed information on the atomic contacts that determine filament stability and describe mechanistic details on the formation of signaling-competent MAVS filaments from inactive monomers. PMID:26733681
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Detection of Taurine in Biological Tissues by 33S NMR Spectroscopy
Musio, Roberta; Sciacovelli, Oronzo
2001-12-01
The potential of 33S NMR spectroscopy for biochemical investigations on taurine (2-aminoethanesulfonic acid) is explored. It is demonstrated that 33S NMR spectroscopy allows the selective and unequivocal identification of taurine in biological samples. 33S NMR spectra of homogenated and intact tissues are reported for the first time, together with the spectrum of a living mollusc. Emphasis is placed on the importance of choosing appropriate signal processing methods to improve the quality of the 33S NMR spectra of biological tissues.
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The potential influence of environmental pollution on amphibian development and decline
Energy Technology Data Exchange (ETDEWEB)
Jung, R.E.
1996-12-31
Globally, amphibians are reportedly declining. Environmental pollution has been hypothesized to be associated with declines. Because of their aquatic development and permeable eggs, skin and gills, amphibians, like fishes, may be particularly susceptible to poor water quality or waterborne pollutants. This dissertation addresses effects of global pollutants such as pesticides, acid rain and associated metal toxicity, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and polychlorinated biphenyls (PCBs) on the development, behavior, and physiology of amphibian early life stages. This report contains only chapter six and conclusions. Chapter 6 reports on a field experiment in which green frogs from two clutches were exposed from egg to 107 days of age to water and sediments in enclosures along a PCB and metal contamination gradient in the Fox River and wetlands near Green Bay, Wisconsin. Green frogs showed lower hatching success and survival at sites with higher contaminant levels compared to cleaner wetland sites along Green Bay. Hatching success in the green frog was most significantly negatively correlated with sediment PCB levels. It can be concluded that environmental pollution and toxicants in aquatic environments can cause problems for amphibian early development. Sometimes the effects are subtle, and sometimes they are dramatic. In general, amphibian early life stages seem particularly sensitive to environmentally-realistic levels of low pH and metals, but appear more tolerant of TCDD and PCBs.
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Teaching NMR spectra analysis with nmr.cheminfo.org.
Patiny, Luc; Bolaños, Alejandro; Castillo, Andrés M; Bernal, Andrés; Wist, Julien
2018-06-01
Teaching spectra analysis and structure elucidation requires students to get trained on real problems. This involves solving exercises of increasing complexity and when necessary using computational tools. Although desktop software packages exist for this purpose, nmr.cheminfo.org platform offers students an online alternative. It provides a set of exercises and tools to help solving them. Only a small number of exercises are currently available, but contributors are invited to submit new ones and suggest new types of problems. Copyright © 2018 John Wiley & Sons, Ltd.
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BnmrOffice: A Free Software for β-nmr Data Analysis
Saadaoui, Hassan
A data-analysis framework with a graphical user interface (GUI) is developed to analyze β-nmr spectra in an automated and intuitive way. This program, named BnmrOffice is written in C++ and employs the QT libraries and tools for designing the GUI, and the CERN's Minuit optimization routines for minimization. The program runs under multiple platforms, and is available for free under the terms of the GNU GPL standards. The GUI is structured in tabs to search, plot and analyze data, along other functionalities. The user can tweak the minimization options; and fit multiple data files (or runs) using single or global fitting routines with pre-defined or new models. Currently, BnmrOffice reads TRIUMF's MUD data and ASCII files, and can be extended to other formats.
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PVT Degradation Studies: NMR Analysis
Energy Technology Data Exchange (ETDEWEB)
Cho, Herman M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kouzes, Richard T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2017-06-06
Under certain environmental conditions, polyvinyl toluene (PVT) plastic scintillator has been observed to undergo internal fogging. Nuclear magnetic resonance spectroscopy has been used to elucidate the state of water inside the PVT. The deuterium NMR results show that water absorbed by PVT under warm, humid conditions enters several distinct environments, and when the PVT is transferred from incubation to ambient temperature and humidity the water is lost on a time scale of a few hours from these samples. Most of the deuterium NMR peaks can be assigned to bulk liquid water, but almost 35% of the detected signal intensity is contained in a resonance that resembles spectra of water contained in nanometer-scale pores in mesoporous carbon.
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NMR imaging of human atherosclerosis
International Nuclear Information System (INIS)
Toussaint, J.F.
1995-01-01
Diagnosis and prognosis of atherosclerosis can no longer be evaluated with morphological parameters only. A description of atherosclerotic plaque composition is necessary to study the mechanisms of plaque rupture, which depends on collagenous cap and lipid core thicknesses. NMR, as a biochemical imaging technique, allows visualization of these components using T1 contrast (mobile lipids), T2 contrast (cap vs. core), spin density (calcifications), diffusion imaging, 1H and 13C spectroscopy. Today, these imaging sequences allow to study in vitro the effects of interventional techniques such as angioplasty or atherectomy. Clinical investigations begin, which will attempt to develop in vivo microscopy and test the ability of NMR to predict plaque rupture. (author). 13 refs., 7 figs
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Condensed Matter NMR under Extreme Conditions: Challenges and Opportunities
Reyes, Arneil
2006-11-01
Advances in resistive magnet and power supply technology have made available extremely high magnetic fields suitable for condensed matter broadline NMR experiments. This capability expands the available phase space for investigating a wide variety of materials using magnetic resonance; utilizing the strength of the field to expose or induce new physical phenomena resulting in better understanding of the physics. Continuous fields up to 45T in NHMFL Hybrid magnet have brought new challenges in designing NMR instrumentation. Field strengths and sample space limitations put constraints on RF pulse power, tuning range, bandwidth, and temperature control. The inclusion of other capabilities, including high pressure, optics, and sample rotation requires intricate probe design and construction, while extremely low milliKelvin temperatures are desired in order to explore energy scales where thermal fluctuations are suppressed. Optimization of these devices has been of paramount consideration in NHMFL Condensed Matter NMR user program. Science achieved at high fields, the new initiatives to develop resistively-detected NMR in 2D electron gas and similar systems, and the current new generation Series-Connected Hybrid magnets for NMR work will be discussed. The NHMFL is supported by the National Science Foundation and the State of Florida.
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Shirooka, Hidehiko; Nishiguchi, Shu; Fukutani, Naoto; Tashiro, Yuto; Nozaki, Yuma; Aoyama, Tomoki
2018-05-01
The association between subjective cognitive decline and falls has not been clearly determined. Our aim was to explore the effect of subjective cognitive decline on falls in community-dwelling older adults with or without objective cognitive decline. We included 470 older adults (mean age 73.6 ± 5.2; 329 women) living in the community and obtained data on fall history directly from the participants. Subjective cognitive decline was assessed using a self-administered question. Objective cognitive function was measured using the Mini-Mental State Examination. Statistical analyses were carried out separately for participants with objective cognitive decline and those without. A multiple logistic regression analysis showed that, among participants without objective cognitive decline, subjective cognitive decline was positively associated with falls [OR 1.91; 95% confidence interval (CI) 1.17-3.12; p = 0.01). Conversely, among participants with objective cognitive decline, subjective cognitive decline was negatively associated with falls (OR 0.07; 95% CI 0.01-0.85, p = 0.04). The result suggests that the objective-subjective disparity may affect falls in community-dwelling older adults. The presence of subjective cognitive decline was significantly positively associated with falls among cognitively intact older adults. However, among their cognitively impaired peers, the absence of subjective cognitive decline was positively associated with falls.
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19F labelled dextrans and antibodies as NMR imaging and spectroscopy agents
International Nuclear Information System (INIS)
Antich, P.P.; Kulkarni, P.V.
1993-01-01
A method is described of NMR imaging or spectroscopy, comprising the steps of administering to a living subject a 19 F labelled NMR agent, the NMR agent comprising (a) a transport polymer selected from the group consisting of dextran polymers and amino dextrans, having a molecular weight between approximately 100 d and 500 kd, and antibodies and fragments thereof, and (b) a 19F-containing sensor moiety selected from the group consisting of fluorinated alkyls, fluorinated acetates, fluoroaniline, and fluoroalkyl phosphonates, in an amount effective to provide a detectable NMR signal; and then detecting the 19 F NMR signal produced
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NMR methods for the investigation of structure and transport
Energy Technology Data Exchange (ETDEWEB)
Hardy, Edme H. [Karlsruher Institut fuer Technologie (KIT), Karlsruhe (Germany). Inst. fuer Mechanische Verfahrenstechnik und Mechanik
2012-07-01
Extensive derivations of required fundamental relations for readers with engineering background New applications based on MRI, PGSE-NMR, and low-field NMR New concepts in quantitative data evaluation and image analysis Methods of nuclear magnetic resonance (NMR) are increasingly applied in engineering sciences. The book summarizes research in the field of chemical and process engineering performed at the Karlsruhe Institute of Technology (KIT). Fundamentals of the methods are exposed for readers with an engineering background. Applications cover the fields of mechanical process engineering (filtration, solid-liquid separation, powder mixing, rheometry), chemical process engineering (trickle-bed reactor, ceramic sponges), bioprocess engineering (biofilm growth), and food process engineering (microwave heating, emulsions). Magnetic Resonance Imaging (MRI) as well as low-field NMR are covered with notes on hardware. Emphasis is placed on quantitative data analysis and image processing. (orig.)
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NMR methods for the investigation of structure and transport
International Nuclear Information System (INIS)
Hardy, Edme H.
2012-01-01
Extensive derivations of required fundamental relations for readers with engineering background New applications based on MRI, PGSE-NMR, and low-field NMR New concepts in quantitative data evaluation and image analysis Methods of nuclear magnetic resonance (NMR) are increasingly applied in engineering sciences. The book summarizes research in the field of chemical and process engineering performed at the Karlsruhe Institute of Technology (KIT). Fundamentals of the methods are exposed for readers with an engineering background. Applications cover the fields of mechanical process engineering (filtration, solid-liquid separation, powder mixing, rheometry), chemical process engineering (trickle-bed reactor, ceramic sponges), bioprocess engineering (biofilm growth), and food process engineering (microwave heating, emulsions). Magnetic Resonance Imaging (MRI) as well as low-field NMR are covered with notes on hardware. Emphasis is placed on quantitative data analysis and image processing. (orig.)
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1H NMR visibility of mammalian glycogen in solution
International Nuclear Information System (INIS)
Zang, L.H.; Rothman, D.L.; Shulman, R.G.
1990-01-01
High-resolution 1 H NMR spectra of rabbit liver glycogen in 2 H 2 O were obtained at 500 MHz, and several resonances were assigned by comparison with the chemical shifts of α-linked diglucose molecules. The NMR relaxation times T 1 and T 2 of glycogen in 2 H 2 O were determined to be 1.1 and 0.029 s, respectively. The measured natural linewidth of the carbon-1 proton is in excellent agreement with that calculated from T 2 . The visibility measurements made by digesting glycogen and comparing glucose and glycogen signal intensities demonstrate that in spite of the very high molecular weight, all of the proton nuclei in glycogen contribute to the NMR spectrum. The result is not unexpected, since 100% NMR visibility was previously observed from the carbon nuclei of glycogen, due to the rapid intramolecular motions
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NMR and the surgery of tumours at the craniocervical junction
International Nuclear Information System (INIS)
Ahyai, A.; Matsumara, A.; Rittmeyer, K.
1987-01-01
The diagnosis of tumors in the posterior fossa and at the craniocervical junction has always been problematic. In this region of the brain a clear visualization of the exact extent and relations of a space-occupying lesion is indispensable in assessing whether it is operable. Even though a tumor with its perifocal edema can be detected by CT, NMR opens new perspectives for the neurosurgeon. The authors present these cases in 3 groups. Group 1 comprises patients for whom NMR results contra-indicated operation. Group II consists of patients who would probably not have been operated on prior to the use of NMR. Group III includes patients who would probably not have been operated on prior to the use of NMR (e.g arachnoid cysts, Dandy-Walker malformations, etc); the excellent multi-dimensional imaging by NMR rendered the advisability of operation questionable, so that improved diagnostics may have spared the patients unnecessary operations
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Contrast-enhanced NMR imaging: animal studies using gadolinium-DTPA complex
International Nuclear Information System (INIS)
Brasch, R.C.; Weinmann, H.J.; Wesbey, G.E.
1984-01-01
Gadolinium (Gd)-DTPA complex was assessed as a nuclear magnetic resonance (NMR) contrast-enhancing agent by experimentally imaging normal and diseased animals. After intravenous injection, Gd-DTPA, a strongly paramagnetic complex by virtue of unpaired electrons, was rapidly excreted into the urine of rats, producing an easily observable contrast enhancement on NMR images in kidney parenchyma and urine. Sterile soft-tissue abscesses demonstrated an obvious rim pattern of enhancement. A focus of radiation-induced brain damage in a canine model was only faintly detectable on spin-echo NMR images before contrast administration; after 0.5 mmol/kg Gd-DTPA administration, the lesion intensity increased from 3867 to 5590. In comparison, the normal brain with an intact blood-brain barrier remained unchanged in NMR characterization. Gd-DTPA is a promising new NMR contrast enhancer for the clinical assessment of renal function, of inflammatory lesions, and of focal disruption of the blood-brain barrier
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Sensitivity of NMR spectra properties to different inversion algorithms. Abstract 97
International Nuclear Information System (INIS)
Bryan, J.; Wang, G.; Vargas, S.; Kantzas, A.
2004-01-01
'Full text:' Low field NMR technology has many applications in the petroleum industry. NMR spectra obtained from logging tools or laboratory instruments can be used to provide an incredible wealth of useful information for formation evaluation and reservoir fluid characterization purposes. In recent years, research performed at the University of Calgary has been instrumental in developing this technology for heavy oil and bitumen related problems. Specifically, low field NMR has been used in several niche applications: in-situ viscosity estimates of heavy oil and bitumen, water-in-oil emulsion and solvent-bitumen mixture viscosity, water cut in produced fluid streams, and oil-water-solids content in oil sands mining samples. The majority of all NMR analyses are based on the interpretation of NMR spectra. These spectra are inverted numerically from the measured NMR decay data. The mathematics of the inversion is generally assumed to be correct, and the analyses revolve around interpretations of how the spectra relate to physical properties of the samples. However, when measuring high viscosity fluids or clay-bound water, the NMR signal relaxes very quickly and it becomes extremely important to ensure that the spectrum obtained is accurate before relating its properties to physics. This work investigates the effect of different inversion algorithms on the generated spectra, and attempts to quantify the magnitude of the errors that can be associated with the mathematics of inversion. This leads to a better understanding of the accuracy of NMR estimates of rock and fluid properties. (author)
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Fourier transform zero field NMR and NQR
International Nuclear Information System (INIS)
Zax, D.B.
1985-01-01
In many systems the chemical shifts measured by traditional high resolution solid state NMR methods are insufficiently sensitive, or the information contained in the dipole-dipole couplings is more important. In these cases, Fourier transform zero field magnetic resonance may make an important contribution. Zero field NMR and NQR is the subject of this thesis. Chapter I presents the quantum mechanical background and notational formalism for what follows. Chapter II gives a brief review of high resolution magnetic resonance methods, with particular emphasis on techniques applicable to dipole-dipole and quadrupolar couplings. Level crossings between spin-1/2 and quadrupolar spins during demagnetization transfer polarization from high to low λ nuclei. This is the basis of very high sensitivity zero field NQR measurements by field cycling. Chapter III provides a formal presentation of the high resolution Fourier transform zero field NMR method. Theoretical signal functions are calculated for common spin systems, and examples of typical spectra are presented. Chapters IV and V review the experimental progress in zero field NMR of dipole-dipole coupled spin-1/2 nuclei and for quadrupolar spin systems. Variations of the simple experiment describe in earlier chapters that use pulsed dc fields are presented in Chapter VI
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NMR blood vessel imaging method and apparatus
International Nuclear Information System (INIS)
Riederer, S.J.
1988-01-01
A high speed method of forming computed images of blood vessels based on measurements of characteristics of a body is described comprising the steps of: subjecting a predetermined body area containing blood vessels of interest to, successively, applications of a short repetition time (TR) NMR pulse sequence during the period of high blood velocity and then to corresponding applications during the period of low blood velocity for successive heart beat cycles; weighting the collected imaging data from each application of the NMR pulse sequence according to whether the data was acquired during the period of high blood velocity or a period of low blood velocity of the corresponding heart beat cycle; accumulating weighted imaging data from a plurality of NMR pulse sequences corresponding to high blood velocity periods and from a plurality of NMR pulse sequences corresponding to low blood velocity periods; subtracting the weighted imaging data corresponding to each specific phase encoding acquired during the high blood velocity periods from the weighted imaging data for the same phase encoding corresponding to low blood velocity periods in order to compute blood vessel imaging data; and forming an image of the blood vessels of interest from the blood vessel imaging data
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Natural abundant (17) O NMR in a 1.5-T Halbach magnet.
Sørensen, Morten K; Bakharev, Oleg N; Jensen, Ole; Nielsen, Niels Chr
2016-06-01
We present mobile, low-field (17) O NMR as a means for monitoring oxygen in liquids. Whereas oxygen is one of the most important elements, oxygen NMR is limited by a poor sensitivity related to low natural abundance and gyro-magnetic ratio of the NMR active (17) O isotope. Here, we demonstrate (17) O NMR detection at a Larmor frequency of 8.74 MHz in a 1.5-T Halbach neodymium magnet with a home-built digital NMR instrument suitable for large-scale production and in-line monitoring applications. The proposed (17) O NMR sensor may be applied for direct, noninvasive measurements of water content in, for example, oil, manure, or food in automated quality or process control. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.
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DEFF Research Database (Denmark)
Huang, Honggang; Larsen, Martin Røssel; Karlsson, Anders H
2011-01-01
phosphorylation in sarcoplasmic proteins from three groups of pigs with different pH decline rates from PM 1 to 24¿h. Globally, the fast pH decline group had the highest phosphorylation level at PM 1¿h, but lowest at 24¿h, whereas the slow pH decline group showed the reverse case. The same pattern was also...... observed in most individual bands in 1-DE. The protein phosphorylation levels of 12 bands were significantly affected by the synergy effects of pH and time (p......Meat quality development is highly influenced by the pH decline caused by the postmortem (PM) glycolysis. Protein phosphorylation is an important mechanism in regulating the activity of glycometabolic enzymes. Here, a gel-based phosphoproteomic study was performed to analyze the protein...
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International Nuclear Information System (INIS)
Moore, J.M.; Chazin, W.J.; Wright, P.E.; Powls, R.
1988-01-01
Two-dimensional 1 H NMR methods have been used to make sequence-specific resonance assignments for the 97 amino acid residues of the plastocyanin from the green alga Scenedesmus obliquus. Assignments were obtained for all backbone protons and the majority of the side-chain protons. Spin system identification relied heavily on the observation of relayed connectivities to the backbone amide proton. Sequence-specific assignments were made by using the sequential assignment procedure. During this process, an extra valine residue was identified that had not been detected in the original amino acid sequence. Elements of regular secondary structure were identified from characteristic NOE connectivities between backbone protons, coupling constant values, and the observation of slowly exchanging amide protons. The protein in solution contains eight β-strands, one short segment of helix, five reverse turns, and five loops. The β-strands may be arranged into two βsheets on the basis of extensive cross-strand NOE connectivities. The chain-folding topology determined from the NMR experiments is that of a Greek key β-barrel and is similar to that observed for French bean plastocyanin in solution and poplar plastocyanin in the crystalline state. While the overall structures are similar, several differences in local structure between the S. obliquus and higher plant plastocyanins have been identified
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Directory of Open Access Journals (Sweden)
Sutawanir Darwis
2012-05-01
Full Text Available Empirical decline curve analysis of oil production data gives reasonable answer in hyperbolic type curves situations; however the methodology has limitations in fitting real historical production data in present of unusual observations due to the effect of the treatment to the well in order to increase production capacity. The development ofrobust least squares offers new possibilities in better fitting production data using declinecurve analysis by down weighting the unusual observations. This paper proposes a robustleast squares fitting lmRobMM approach to estimate the decline rate of daily production data and compares the results with reservoir simulation results. For case study, we usethe oil production data at TBA Field West Java. The results demonstrated that theapproach is suitable for decline curve fitting and offers a new insight in decline curve analysis in the present of unusual observations.
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1D AND 2D NMR STUDIES OF BENZYL O–VANILLIN
Directory of Open Access Journals (Sweden)
Mohammed Hadi Al–Douh
2010-06-01
Full Text Available The reaction of o-vanillin A with benzyl bromide B2 in acetone as the solvent and K2CO3 as a base in the presence of tetra-n-butylammonium iodide (TBAI as catalyst formed benzyl o-vanillin, C. The complete assignments of C using PROTON, APT, DEPT-135, COSY, NOESY, HMQC and HMBC NMR in both CDCl3 and acetone-d6 are discussed, and the coupling constants J are reported in Hertz (Hz. Keywords: 1H NMR; 13C NMR; 2D NMR; Benzyl o-Vanillin
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Early-Transition Output Decline Revisited
Directory of Open Access Journals (Sweden)
Crt Kostevc
2016-05-01
Full Text Available In this paper we revisit the issue of aggregate output decline that took place in the early transition period. We propose an alternative explanation of output decline that is applicable to Central- and Eastern-European countries. In the first part of the paper we develop a simple dynamic general equilibrium model that builds on work by Gomulka and Lane (2001. In particular, we consider price liberalization, interpreted as elimination of distortionary taxation, as a trigger of the output decline. We show that price liberalization in interaction with heterogeneous adjustment costs and non-employment benefits lead to aggregate output decline and surge in wage inequality. While these patterns are consistent with actual dynamics in CEE countries, this model cannot generate output decline in all sectors. Instead sectors that were initially taxed even exhibit output growth. Thus, in the second part we consider an alternative general equilibrium model with only one production sector and two types of labor and distortion in a form of wage compression during the socialist era. The trigger for labor mobility and consequently output decline is wage liberalization. Assuming heterogeneity of workers in terms of adjustment costs and non-employment benefits can explain output decline in all industries.
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NMR - from basic physics to images of the human body
International Nuclear Information System (INIS)
Richards, Rex.
1985-01-01
Nuclear magnetic resonance (NMR) is a remarkable phenomenon which involves the exchange of very weak radio frequency radiation between atomic nuclei and a sensitive detecting apparatus. It was originally regarded as a rather esoteric effect of great theoretical interest, but has since proved to have an amazing range of applications over many scientific disciplines, including nuclear physics, solid state physics, all branches of chemistry, biochemistry, physiology and most recently in medical diagnosis. In this Discourse the principles of NMR and trace briefly the history of its applications are examined and illustrated. Headings are: early history; nuclear resonance; relaxation time; the chemical shift; spin-spin coupling (NMR spectra); chemical shifts in biological tissue; NMR imaging; conclusions. (author)
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Longitudinal decline of driving safety in Parkinson disease.
Uc, Ergun Y; Rizzo, Matthew; O'Shea, Amy M J; Anderson, Steven W; Dawson, Jeffrey D
2017-11-07
To longitudinally assess and predict on-road driving safety in Parkinson disease (PD). Drivers with PD (n = 67) and healthy controls (n = 110) drove a standardized route in an instrumented vehicle and were invited to return 2 years later. A professional driving expert reviewed drive data and videos to score safety errors. At baseline, drivers with PD performed worse on visual, cognitive, and motor tests, and committed more road safety errors compared to controls (median PD 38.0 vs controls 30.5; p < 0.001). A smaller proportion of drivers with PD returned for repeat testing (42.8% vs 62.7%; p < 0.01). At baseline, returnees with PD made fewer errors than nonreturnees with PD (median 34.5 vs 40.0; p < 0.05) and performed similar to control returnees (median 33). Baseline global cognitive performance of returnees with PD was better than that of nonreturnees with PD, but worse than for control returnees ( p < 0.05). After 2 years, returnees with PD showed greater cognitive decline and larger increase in error counts than control returnees (median increase PD 13.5 vs controls 3.0; p < 0.001). Driving error count increase in the returnees with PD was predicted by greater error count and worse visual acuity at baseline, and by greater interval worsening of global cognition, Unified Parkinson's Disease Rating Scale activities of daily living score, executive functions, visual processing speed, and attention. Despite drop out of the more impaired drivers within the PD cohort, returning drivers with PD, who drove like controls without PD at baseline, showed many more driving safety errors than controls after 2 years. Driving decline in PD was predicted by baseline driving performance and deterioration of cognitive, visual, and functional abnormalities on follow-up. © 2017 American Academy of Neurology.
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High-resolution proton and carbon-13 NMR of membranes: why sonicate?
International Nuclear Information System (INIS)
Oldfield, E.; Bowers, J.L.; Forbes, J.
1987-01-01
The authors have obtained high-field (11.7-T) proton and carbon-13 Fourier transform (FT) nuclear magnetic resonance (NMR) spectra of egg lecithin and egg lecithin-chloresterol (1:1) multibilayers, using magic-angle sample spinning (MASS) techniques, and sonicated egg lecithin and egg lecithin-cholesterol (1:1) vesicles, using conventional FT NMR methods. Resolution of the proton and carbon-13 MASS NMR spectra of the pure egg lecithin samples is essentially identical with that of sonicated samples, but spectra of the unsonicated lipid, using MASS, can be obtained very much faster than with the more dilute, sonicated systems. With the 1:1 lecithin-cholesterol system, proton MASS NMR spectra are virtually identical with conventional FT spectra of sonicated samples, while the 13 C NMR, the authors demonstrate that most 13 C nuclei in the cholesterol moiety can be monitored, even though these same nuclei are essentially invisible, i.e., are severely broadened, in the corresponding sonicated systems. In addition, 13 C MASS NMR spectra can again be recorded much faster than with sonicated samples, due to concentration effects. Taken together, these results strongly suggest there will seldom be need in the future to resort to ultransonic disruption of lipid bilayer membranes in order to obtain high-resolution proton or carbon-13 NMR spectra
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Vivaldi: Visualization and validation of biomacromolecular NMR structures from the PDB
Hendrickx, Pieter M S; Gutmanas, Aleksandras; Kleywegt, Gerard J
2013-01-01
We describe Vivaldi (VIsualization and VALidation DIsplay; http://pdbe.org/vivaldi), a web-based service for the analysis, visualization, and validation of NMR structures in the Protein Data Bank (PDB). Vivaldi provides access to model coordinates and several types of experimental NMR data using interactive visualization tools, augmented with structural annotations and model-validation information. The service presents information about the modeled NMR ensemble, validation of experimental chemical shifts, residual dipolar couplings, distance and dihedral angle constraints, as well as validation scores based on empirical knowledge and databases. Vivaldi was designed for both expert NMR spectroscopists and casual non-expert users who wish to obtain a better grasp of the information content and quality of NMR structures in the public archive. © Proteins 2013. © 2012 Wiley Periodicals, Inc. PMID:23180575
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Multinuclear NMR of CaSiO(3) glass: simulation from first-principles.
Pedone, Alfonso; Charpentier, Thibault; Menziani, Maria Cristina
2010-06-21
An integrated computational method which couples classical molecular dynamics simulations with density functional theory calculations is used to simulate the solid-state NMR spectra of amorphous CaSiO(3). Two CaSiO(3) glass models are obtained by shell-model molecular dynamics simulations, successively relaxed at the GGA-PBE level of theory. The calculation of the NMR parameters (chemical shielding and quadrupolar parameters), which are then used to simulate solid-state 1D and 2D-NMR spectra of silicon-29, oxygen-17 and calcium-43, is achieved by the gauge including projector augmented-wave (GIPAW) and the projector augmented-wave (PAW) methods. It is shown that the limitations due to the finite size of the MD models can be overcome using a Kernel Estimation Density (KDE) approach to simulate the spectra since it better accounts for the disorder effects on the NMR parameter distribution. KDE allows reconstructing a smoothed NMR parameter distribution from the MD/GIPAW data. Simulated NMR spectra calculated with the present approach are found to be in excellent agreement with the experimental data. This further validates the CaSiO(3) structural model obtained by MD simulations allowing the inference of relationships between structural data and NMR response. The methods used to simulate 1D and 2D-NMR spectra from MD GIPAW data have been integrated in a package (called fpNMR) freely available on request.
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(3,2)D GFT-NMR experiments for fast data collection from proteins
International Nuclear Information System (INIS)
Xia Youlin; Zhu Guang; Veeraraghavan, Sudha; Gao Xiaolian
2004-01-01
High throughput structure determination of proteins will contribute to the success of proteomics investigations. The G-Matrix Fourier Transformation NMR (GFT-NMR) method significantly shortens experimental time by reducing the number of the dimensions of data acquisition for isotopically labeled proteins (Kim, S. and Szyperski, T. (2003) J. Am. Chem. Soc.125, 1385). We demonstrate herein a suite of ten 3D → 2D or (3,2)D GFT-NMR experiments using 13 C/ 15 N-labeled ubiquitin. These experiments were completed within 18 hours, representing a 4- to 18-fold reduction in data acquisition time compared to the corresponding conventional 3D experiments. A subset of the GFT-NMR experiments, (3,2)D HNCO, HNCACB, HN(CO)CACB, and 2D 1 H- 15 N HSQC, which are necessary for backbone assignments, were carried out within 6 hours. To facilitate the analysis of the GFT-NMR spectra, we developed automated procedures for viewing and analyzing the GFT-NMR spectra. Our overall strategy allows (3,2)D GFT-NMR experiments to be readily performed and analyzed. Nevertheless, the increase in spectral overlap and the reduction in signal sensitivity in these fast NMR experiments presently limit their application to relatively small proteins
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Portable, low-cost NMR with laser-lathe lithography produced microcoils.
Demas, Vasiliki; Herberg, Julie L; Malba, Vince; Bernhardt, Anthony; Evans, Lee; Harvey, Christopher; Chinn, Sarah C; Maxwell, Robert S; Reimer, Jeffrey
2007-11-01
Nuclear Magnetic Resonance (NMR) is unsurpassed in its ability to non-destructively probe chemical identity. Portable, low-cost NMR sensors would enable on-site identification of potentially hazardous substances, as well as the study of samples in a variety of industrial applications. Recent developments in RF microcoil construction (i.e. coils much smaller than the standard 5mm NMR RF coils), have dramatically increased NMR sensitivity and decreased the limits-of-detection (LOD). We are using advances in laser pantographic microfabrication techniques, unique to LLNL, to produce RF microcoils for field deployable, high sensitivity NMR-based detectors. This same fabrication technique can be used to produce imaging coils for MRI as well as for standard hardware shimming or "ex-situ" shimming of field inhomogeneities typically associated with inexpensive magnets. This paper describes a portable NMR system based on the use of a 2 kg hand-held permanent magnet, laser-fabricated microcoils, and a compact spectrometer. The main limitations for such a system are the low resolution and sensitivity associated with the low field values and quality of small permanent magnets, as well as the lack of large amounts of sample of interest in most cases. The focus of the paper is on the setting up of this system, initial results, sensitivity measurements, discussion of the limitations and future plans. The results, even though preliminary, are promising and provide the foundation for developing a portable, inexpensive NMR system for chemical analysis. Such a system will be ideal for chemical identification of trace substances on site.
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Stripline-based microfluidic devices for high-resolution NMR spectroscopy
Bart, J.
2009-01-01
A novel route towards microchip integrated NMR analysis was studied. For NMR analysis of mass-limited samples, research has focussed for decennia on microsolenoidal or planar helical detection coils on microfluidic substrates. Since these approaches suffer from static field distortion resulting in
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Dietary pattern, inflammation and cognitive decline: The Whitehall II prospective cohort study.
Ozawa, Mio; Shipley, Martin; Kivimaki, Mika; Singh-Manoux, Archana; Brunner, Eric J
2017-04-01
Low-grade inflammation appears to play an etiological role in cognitive decline. However the association between an inflammatory dietary pattern and cognitive decline has not been investigated. We aimed to investigate dietary patterns associated with inflammation and whether such diet is associated with cognitive decline. We analyzed 5083 participants (28.7% women) from the Whitehall II cohort study. Diet and serum interleukin-6 (IL-6) were assessed in 1991-1993 and 1997-1999. We used reduced rank regression methods to determine a dietary pattern associated with elevated IL-6. Cognitive tests were performed in 1997-1999 and repeated in 2002-2004 and 2007-2009. The association between dietary pattern and cognitive decline between ages 45 and 79 was assessed using linear mixed models. We identified an inflammatory dietary pattern characterized by higher intake of red meat, processed meat, peas and legumes, and fried food, and lower intake of whole grains which correlated with elevated IL-6 both in 1991-1993 and 1997-1999. A greater decline in reasoning was seen in participants in the highest tertile of adherence to the inflammatory dietary pattern (-0.37 SD; 95% confidence interval [CI] -0.40, -0.34) compared to those in the lowest tertile (-0.31; 95% CI -0.34, -0.28) after adjustment for age, sex, ethnicity, occupational status, education, and total energy intake (p for interaction across tertiles = 0.01). This association remained significant after multivariable adjustment. Similarly for global cognition, the inflammatory dietary pattern was associated with faster cognitive decline after multivariable adjustment (p for interaction across tertiles = 0.04). Associations were stronger in younger participants (dietary pattern characterized as higher intake of red and processed meat, peas, legumes and fried food, and lower intake of whole grains was associated with higher inflammatory markers and accelerated cognitive decline at older ages. This supports the
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International Nuclear Information System (INIS)
Smith, F.W.
1987-01-01
The development of NMR for clinical use has been complicated by a number of controversies, the largest of these being the question of what is the optimum field strength for proton imaging. Many workers believe that diagnostically useful images can only be produced at high field strength (i.e. 0.5 - 2.0 T), where in fact diagnostically useful images are made using field strengths of as low as 0.02 T. Because the method is more complex than X-ray CT, which relies on the measurement of only one parameter, tissue density, many new users have difficulty in selecting the correct imaging pulse sequence to provide the most useful image for diagnosis. NMR imaging pulse sequence may be selected to produce images of the proton density, T/sub 1/ or T/sub 2/ signals, or combinations of them. When this facility is used, images which are T/sub 1/ or T/sub 2/ weighted can be selected. Inversion-recovery sequences are more appropriate for imaging the abdomen where by selecting a short TR interval the signal from subcutaneous fat, which is the major cause of image artefact in abdominal imaging, is suppressed thereby improving image quality. The use of surface receiver coils, which are applied closely to the area of the body being examined is becoming more widespread and is of particular value when examining the orbits, facial structures, neck, breast, spine and limbs. The use of these coils together with a discussion of patient selection for NMR imaging, image interpretation and data storage follow
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Cell signaling, post-translational protein modifications and NMR spectroscopy
International Nuclear Information System (INIS)
Theillet, Francois-Xavier; Smet-Nocca, Caroline; Liokatis, Stamatios; Thongwichian, Rossukon; Kosten, Jonas; Yoon, Mi-Kyung; Kriwacki, Richard W.; Landrieu, Isabelle; Lippens, Guy; Selenko, Philipp
2012-01-01
Post-translationally modified proteins make up the majority of the proteome and establish, to a large part, the impressive level of functional diversity in higher, multi-cellular organisms. Most eukaryotic post-translational protein modifications (PTMs) denote reversible, covalent additions of small chemical entities such as phosphate-, acyl-, alkyl- and glycosyl-groups onto selected subsets of modifiable amino acids. In turn, these modifications induce highly specific changes in the chemical environments of individual protein residues, which are readily detected by high-resolution NMR spectroscopy. In the following, we provide a concise compendium of NMR characteristics of the main types of eukaryotic PTMs: serine, threonine, tyrosine and histidine phosphorylation, lysine acetylation, lysine and arginine methylation, and serine, threonine O-glycosylation. We further delineate the previously uncharacterized NMR properties of lysine propionylation, butyrylation, succinylation, malonylation and crotonylation, which, altogether, define an initial reference frame for comprehensive PTM studies by high-resolution NMR spectroscopy.
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Characteristic of cognitive decline in Parkinson's disease: a 1-year follow-up.
McKinlay, Audrey; Grace, Randolph C
2011-10-01
The aim of this study was to track the evolution of cognitive decline in Parkinson's disease (PD) patients 1 year after baseline testing. Thirty-three PD patients, divided according to three previously determined subgroups based on their initial cognitive performance, and a healthy comparison group were reassessed after a 1-year interval. Participants were assessed in the following five domains: Executive Function, Problem Solving, Working Memory/Attention, Memory, and Visuospatial Ability. The PD groups differed on the domains of Executive Function, Problem Solving, and Working Memory, with the most severe deficits being evident for the group that had previously shown the greatest level of impairment. Increased cognitive problems were also associated with decreased functioning in activities of daily living. The most severely impaired group had evidence of global cognitive decline, possibly reflecting a stage of preclinical dementia.
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Perspectives of biomolecular NMR in drug discovery: the blessing and curse of versatility
International Nuclear Information System (INIS)
Jahnke, Wolfgang
2007-01-01
The versatility of NMR and its broad applicability to several stages in the drug discovery process is well known and generally considered one of the major strengths of NMR (Pellecchia et al., Nature Rev Drug Discov 1:211-219, 2002; Stockman and Dalvit, Prog Nucl Magn Reson Spectrosc 41:187-231, 2002; Lepre et al., Comb Chem High throughput screen 5:583-590, 2002; Wyss et al., Curr Opin Drug Discov Devel 5:630-647, 2002; Jahnke and Widmer, Cell Mol Life Sci 61:580-599, 2004; Huth et al., Methods Enzymol 394:549-571, 2005b; Klages et al., Mol Biosyst 2:318-332, 2006; Takeuchi and Wagner, Curr Opin Struct Biol 16:109-117, 2006; Zartler and Shapiro, Curr Pharm Des 12:3963-3972, 2006). Indeed, NMR is the only biophysical technique which can detect and quantify molecular interactions, and at the same time provide detailed structural information with atomic level resolution. NMR should therefore be ideally suited and widely requested as a tool for drug discovery research, and numerous examples of drug discovery projects which have substantially benefited from NMR contributions or were even driven by NMR have been described in the literature. However, not all pharmaceutical companies have rigorously implemented NMR as integral tool of their research processes. Some companies invest with limited resources, and others do not use biomolecular NMR at all. This discrepancy in assessing the value of a technology is striking, and calls for clarification-under which circumstances can NMR provide added value to the drug discovery process? What kind of contributions can NMR make, and how is it implemented and integrated for maximum impact? This perspectives article suggests key areas of impact for NMR, and a model of integrating NMR with other technologies to realize synergies and maximize their value for drug discovery
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Demography and growth: two forces leading to rising global income inequality
Rougoor, W.; van Marrewijk, C.; Jiaotong, X.
2014-01-01
Global income inequality has been declining for several decades. We argue that global income inequality will reach its lowest level around 2027 and then will rise again. This development is the result of both economic and demographic forces. By combining economic projections with demographic
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Dittrich, K; Gu, J; Tinder, R; Hogan, M; Gao, X
1994-04-12
The antiparallel purine.purine.pyrimidine DNA triplex, RRY6, which contains a T.C.G inverted triplet in the center of the sequence, was examined by proton and phosphorous two-dimensional NMR spectroscopy. The local conformation of the T.C.G triplet (T4.C11.G18) and the effect of this triplet on the global helical structure were analyzed in detail. The formation of the T.C.G triplet is confirmed by a set of cross-strand NOEs, including unusual cross-strand NOEs between the third strand and the pyrimidine strand as opposed to the purine strand of the duplex. NMR data suggest that the T.C.G triplet may be present in an equilibrium between a non-hydrogen-bonded form and a T(O4)-C(NH2) hydrogen-bonded form and that there is a distortion of the in-plane alignment of the three bases. The flanking G.G.C base triplets are well-defined on the 5'-side of T4, but somewhat interrupted on the 3'-side of T4. The effect of the third strand binding on the Watson-Crick duplex was probed by an NMR study of the free duplex RY6. NMR parameters are affected mostly around the T.C.G inversion site. The perturbations extend to at least two adjacent base triplets on either side. The binding of the third purine strand and the accommodation of a central T.C.G inversion in RRY6 does not require a readjustment in sugar pucker, which remains in the range of C2'-endo. 31P resonances of RRY6 distribute over a range of 2.2 ppm. The H-P coupling patterns of the third strand differ from those of the duplex. General spectral patterns defined by the marker protons of the RRY and YRY triplexes are compared.
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Functional Analysis of the Nitrogen Metabolite Repression Regulator Gene nmrA in Aspergillus flavus
Directory of Open Access Journals (Sweden)
Xiaoyun Han
2016-11-01
Full Text Available In Aspergillus nidulans, the nitrogen metabolite repression regulator NmrA plays a major role in regulating the activity of the GATA transcription factor AreA during nitrogen metabolism. However, the function of nmrA in Aspergillus flavus has notbeen previously studied. Here, we report the identification and functional analysis of nmrA in A. flavus. Our work showed that the amino acid sequences of NmrA are highly conserved among Aspergillus species and that A. flavus NmrA protein contains a canonical Rossmann fold motif. Deletion of nmrA slowed the growth of A. flavus but significantly increased conidiation and sclerotia production. Moreover, seed infection experiments indicated that nmrA is required for the invasive virulence of A. flavus. In addition, the ΔnmrA mutant showed increased sensitivity to rapamycin and methyl methanesulfonate, suggesting that nmrA could be responsive to target of rapamycin signaling and DNA damage. Furthermore, quantitative real-time reverse transcription polymerase chain reaction analysis suggested that nmrA might interact with other nitrogen regulatory and catabolic genes. Our study provides a better understanding of nitrogen metabolite repression and the nitrogen metabolism network in fungi.
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Moessbauer and NMR study of novel Tin(IV)-lactames
Energy Technology Data Exchange (ETDEWEB)
Kuzmann, Erno; Szalay, Roland; Homonnay, Zoltan, E-mail: homonnay@ludens.elte.hu; Nagy, Sandor [Eoetvoes Lorand University, Institute of Chemistry (Hungary)
2012-03-15
N-tributylstannylated 2-pyrrolidinone was reacted with tributyltin triflate in different molar ratios and the complex formation monitored using {sup 1}H-NMR, {sup 13}C-NMR and {sup 119}Sn Moessbauer spectroscopy. Comparing the carbon NMR and tin Moessbauer results, a reaction scheme is suggested for the complexation which assumes the formation of a simultaneously O- and N-tributylstannylated pyrrolidinone cation. The formation of the only O-stannylated pyrrolidinone is also assumed to account for the non-constant Moessbauer parameters of the two tin environments in the distannylated pyrrolidinone cation when the ratio of tributyltin triflate is increased in the reaction.
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Energy Technology Data Exchange (ETDEWEB)
Rosato, Antonio [University of Florence, Department of Chemistry and Magnetic Resonance Center (Italy); Vranken, Wim [Vrije Universiteit Brussel, Structural Biology Brussels (Belgium); Fogh, Rasmus H.; Ragan, Timothy J. [University of Leicester, Department of Biochemistry, School of Biological Sciences (United Kingdom); Tejero, Roberto [Universidad de Valencia, Departamento de Química Física (Spain); Pederson, Kari; Lee, Hsiau-Wei; Prestegard, James H. [University of Georgia, Complex Carbohydrate Research Center and Northeast Structural Genomics Consortium (United States); Yee, Adelinda; Wu, Bin; Lemak, Alexander; Houliston, Scott; Arrowsmith, Cheryl H. [University of Toronto, Department of Medical Biophysics, Cancer Genomics and Proteomics, Ontario Cancer Institute, Northeast Structural Genomics Consortium (Canada); Kennedy, Michael [Miami University, Department of Chemistry and Biochemistry, Northeast Structural Genomics Consortium (United States); Acton, Thomas B.; Xiao, Rong; Liu, Gaohua; Montelione, Gaetano T., E-mail: guy@cabm.rutgers.edu [The State University of New Jersey, Department of Molecular Biology and Biochemistry, Center for Advanced Biotechnology and Medicine, Northeast Structural Genomics Consortium, Rutgers (United States); Vuister, Geerten W., E-mail: gv29@le.ac.uk [University of Leicester, Department of Biochemistry, School of Biological Sciences (United Kingdom)
2015-08-15
The second round of the community-wide initiative Critical Assessment of automated Structure Determination of Proteins by NMR (CASD-NMR-2013) comprised ten blind target datasets, consisting of unprocessed spectral data, assigned chemical shift lists and unassigned NOESY peak and RDC lists, that were made available in both curated (i.e. manually refined) or un-curated (i.e. automatically generated) form. Ten structure calculation programs, using fully automated protocols only, generated a total of 164 three-dimensional structures (entries) for the ten targets, sometimes using both curated and un-curated lists to generate multiple entries for a single target. The accuracy of the entries could be established by comparing them to the corresponding manually solved structure of each target, which was not available at the time the data were provided. Across the entire data set, 71 % of all entries submitted achieved an accuracy relative to the reference NMR structure better than 1.5 Å. Methods based on NOESY peak lists achieved even better results with up to 100 % of the entries within the 1.5 Å threshold for some programs. However, some methods did not converge for some targets using un-curated NOESY peak lists. Over 90 % of the entries achieved an accuracy better than the more relaxed threshold of 2.5 Å that was used in the previous CASD-NMR-2010 round. Comparisons between entries generated with un-curated versus curated peaks show only marginal improvements for the latter in those cases where both calculations converged.
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International Nuclear Information System (INIS)
Rosato, Antonio; Vranken, Wim; Fogh, Rasmus H.; Ragan, Timothy J.; Tejero, Roberto; Pederson, Kari; Lee, Hsiau-Wei; Prestegard, James H.; Yee, Adelinda; Wu, Bin; Lemak, Alexander; Houliston, Scott; Arrowsmith, Cheryl H.; Kennedy, Michael; Acton, Thomas B.; Xiao, Rong; Liu, Gaohua; Montelione, Gaetano T.; Vuister, Geerten W.
2015-01-01
The second round of the community-wide initiative Critical Assessment of automated Structure Determination of Proteins by NMR (CASD-NMR-2013) comprised ten blind target datasets, consisting of unprocessed spectral data, assigned chemical shift lists and unassigned NOESY peak and RDC lists, that were made available in both curated (i.e. manually refined) or un-curated (i.e. automatically generated) form. Ten structure calculation programs, using fully automated protocols only, generated a total of 164 three-dimensional structures (entries) for the ten targets, sometimes using both curated and un-curated lists to generate multiple entries for a single target. The accuracy of the entries could be established by comparing them to the corresponding manually solved structure of each target, which was not available at the time the data were provided. Across the entire data set, 71 % of all entries submitted achieved an accuracy relative to the reference NMR structure better than 1.5 Å. Methods based on NOESY peak lists achieved even better results with up to 100 % of the entries within the 1.5 Å threshold for some programs. However, some methods did not converge for some targets using un-curated NOESY peak lists. Over 90 % of the entries achieved an accuracy better than the more relaxed threshold of 2.5 Å that was used in the previous CASD-NMR-2010 round. Comparisons between entries generated with un-curated versus curated peaks show only marginal improvements for the latter in those cases where both calculations converged
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Solid-state NMR studies of nucleic acid components
Czech Academy of Sciences Publication Activity Database
Dračínský, Martin; Hodgkinson, P.
2015-01-01
Roč. 5, č. 16 (2015), s. 12300-12310 ISSN 2046-2069 R&D Projects: GA ČR GA13-24880S Institutional support: RVO:61388963 Keywords : NMR spectroscopy * nucleic acid s * solid-state NMR Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.289, year: 2015 http://pubs.rsc.org/en/content/articlepdf/2015/ra/c4ra14404j
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Modeling Ne-21 NMR parameters for carbon nanosystems
Czech Academy of Sciences Publication Activity Database
Kupka, T.; Nieradka, M.; Kaminský, Jakub; Stobinski, L.
2013-01-01
Roč. 51, č. 10 (2013), s. 676-681 ISSN 0749-1581 R&D Projects: GA ČR GAP208/11/0105; GA MŠk(CZ) LH11033 Grant - others:AV ČR(CZ) M200551205 Institutional support: RVO:61388963 Keywords : Ne-21 NMR * GIAO NMR * molecular modeling * carbon nanostructures Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 1.559, year: 2013
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Rapid NMR method for the quantification of organic compounds in thin stillage.
Ratanapariyanuch, Kornsulee; Shen, Jianheng; Jia, Yunhua; Tyler, Robert T; Shim, Youn Young; Reaney, Martin J T
2011-10-12
Thin stillage contains organic and inorganic compounds, some of which may be valuable fermentation coproducts. This study describes a thorough analysis of the major solutes present in thin stillage as revealed by NMR and HPLC. The concentration of charged and neutral organic compounds in thin stillage was determined by excitation sculpting NMR methods (double pulse field gradient spin echo). Compounds identified by NMR included isopropanol, ethanol, lactic acid, 1,3-propanediol, acetic acid, succinic acid, glycerophosphorylcholine, betaine, glycerol, and 2-phenylethanol. The concentrations of lactic and acetic acid determined with NMR were comparable to those determined using HPLC. HPLC and NMR were complementary, as more compounds were identified using both methods. NMR analysis revealed that stillage contained the nitrogenous organic compounds betaine and glycerophosphorylcholine, which contributed as much as 24% of the nitrogen present in the stillage. These compounds were not observed by HPLC analysis.
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11B nutation NMR study of powdered borosilicates
International Nuclear Information System (INIS)
Woo, Ae Ja; Yang, Kyung Hwa; Han, Duk Young
1998-01-01
In this work, we applied the 1D 11 B nutation NMR method for the analysis of the local structural environments in powdered borosilicates (SiO 2 -B 2 O 3 ). Spin dynamics during a rf irradiation for spin I=3/2 was analytically calculated with a density matrix formalism. Spectral simulation programs were written in MATLAB on a PC. Two borosilicates prepared by the sol-gel process at different stabilization temperature were used for the 1D 11 B nutation NMR experiment. The 11 B NMR parameters, quadrupole coupling constants (e 2 qQ/h) and asymmetry parameters (η), for each borosilicate were extracted from the nonlinear least-squares fitting. The effects of heat treatments on the local structures of boron sites in borosilicates were discussed
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The installation of a commercial resistive NMR imager
International Nuclear Information System (INIS)
Smith, M.A.; Best, J.J.K.; Douglas, R.H.B.; Kean, D.M.
1984-01-01
It has been demonstrated that a relatively low-cost resistive NMR imager can be installed in a normal hospital environment without many major or expensive modifications. The magnet can be adjusted to give adequate uniformity and there is sufficient RF shielding to give good quality clinical images. The fringe field of the magnet of this system, which operates at the lowest field strength of any commercial NMR imager, does not present a problem to imaging unit staff. The long term reliability and detailed specifications with regard to image quality have yet to be determined. These will be determined whilst the imager is being used for clinical studies as part of the national clinical evaluation of NMR imaging supported by the Medical Research Council. (author)
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Thermometry of hot spot using NMR for hyperthermia
International Nuclear Information System (INIS)
Amemiya, Yoshifumi; Kamimura, Yoshitsugu
1983-01-01
Lately noticed hyperthermia in cancer therapy requires non-invasive measurement of the temperature at the warmed site in the deep portion of human body. Nuclear magnetic relaxation time of NMR is also usable for cancer diagnosis. For coordination of these two techniques, it was judged suitable to measure temperature by NMR so that cancer diagnosis and treatment and evaluation of therapeutic effect might be incorporated into one system. This report dealt with concrete procedures of measuring the temperature of deep portions by NMR. Computations revealed that the coefficient of temperature of the thermal equilibrium magnetization was useful, that magnetic field focusing was the most effective imaging technique and that temperature rise in areas about 2 cm in radius could be measured without large errors. (Chiba, N.)
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Structural Studies of Biological Solids Using NMR
Ramamoorthy, Ayyalusamy
2011-03-01
High-resolution structure and dynamics of biological molecules are important in understanding their function. While studies have been successful in solving the structures of water-soluble biomolecules, it has been proven difficult to determine the structures of membrane proteins and fibril systems. Recent studies have shown that solid-state NMR is a promising technique and could be highly valuable in studying such non-crystalline and non-soluble biosystems. I will present strategies to study the structures of such challenging systems and also about the applications of solid-state NMR to study the modes of membrane-peptide interactions for a better assessment of the prospects of antimicrobial peptides as substitutes to antibiotics in the control of human disease. Our studies on the mechanism of membrane disruption by LL-37 (a human antimicrobial peptide), analogs of the naturally occurring antimicrobial peptide magainin2 extracted from the skin of the African frog Xenopus Laevis, and pardaxin will be presented. Solid-state NMR experiments were used to determine the secondary structure, dynamics and topology of these peptides in lipid bilayers. Similarities and difference in the cell-lysing mechanism, and their dependence on the membrane composition, of these peptides will be discussed. Atomic-level resolution NMR structures of amyloidogenic proteins revealing the misfolding pathway and early intermediates that play key roles in amyloid toxicity will also be presented.
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A novel in situ electrochemical NMR cell with a palisade gold film electrode
Ni, Zu-Rong; Cui, Xiao-Hong; Cao, Shuo-Hui; Chen, Zhong
2017-08-01
In situ electrochemical nuclear magnetic resonance (EC-NMR) has attracted considerable attention because of its ability to directly observe real-time electrochemical processes. Therefore, minimizing the incompatibility between the electrochemical device and NMR detection has become an important challenge. A circular thin metal film deposited on the outer surface of a glass tube with a thickness considerably less than the metal skin depth is considered to be the ideal working electrode. In this study, we demonstrate that such a thin film electrode still has a great influence on the radio frequency field homogeneity in the detective zone of the NMR spectrometer probe and provide theoretical and experimental confirmation of its electromagnetic shielding. Furthermore, we propose a novel palisade gold film device to act as the working electrode. The NMR nutation behavior of protons shows that the uniformity of the radio frequency field is greatly improved, increasing the sensitivity in NMR detection. Another advantage of the proposed device is that an external reference standard adapted to the reaction compound can be inserted as a probe to determine the fluctuation of the physico-chemical environment and achieve high-accuracy quantitative NMR analysis. A three-chamber electrochemical device based on the palisade gold film design was successfully fabricated and the in situ electrochemical NMR performance was validated in a standard 5 mm NMR probe by acquiring voltammograms and high-resolution NMR spectra to characterize the electrochemically generated species. The evolution of in situ EC-NMR spectrum monitoring of the redox transformation between p-benzoquinone and hydroquinone demonstrates the ability of the EC-NMR device to simultaneously quantitatively determine the reactants and elucidate the reaction mechanism at the molecular level.
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A novel in situ electrochemical NMR cell with a palisade gold film electrode
Directory of Open Access Journals (Sweden)
Zu-Rong Ni
2017-08-01
Full Text Available In situ electrochemical nuclear magnetic resonance (EC-NMR has attracted considerable attention because of its ability to directly observe real-time electrochemical processes. Therefore, minimizing the incompatibility between the electrochemical device and NMR detection has become an important challenge. A circular thin metal film deposited on the outer surface of a glass tube with a thickness considerably less than the metal skin depth is considered to be the ideal working electrode. In this study, we demonstrate that such a thin film electrode still has a great influence on the radio frequency field homogeneity in the detective zone of the NMR spectrometer probe and provide theoretical and experimental confirmation of its electromagnetic shielding. Furthermore, we propose a novel palisade gold film device to act as the working electrode. The NMR nutation behavior of protons shows that the uniformity of the radio frequency field is greatly improved, increasing the sensitivity in NMR detection. Another advantage of the proposed device is that an external reference standard adapted to the reaction compound can be inserted as a probe to determine the fluctuation of the physico-chemical environment and achieve high-accuracy quantitative NMR analysis. A three-chamber electrochemical device based on the palisade gold film design was successfully fabricated and the in situ electrochemical NMR performance was validated in a standard 5 mm NMR probe by acquiring voltammograms and high-resolution NMR spectra to characterize the electrochemically generated species. The evolution of in situ EC-NMR spectrum monitoring of the redox transformation between p-benzoquinone and hydroquinone demonstrates the ability of the EC-NMR device to simultaneously quantitatively determine the reactants and elucidate the reaction mechanism at the molecular level.
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LC-NMR coupling technology: recent advancements and applications in natural products analysis
Exarchou, V.; Krucker, M.; Beek, van T.A.; Vervoort, J.J.M.; Gerothanassis, I.P.; Albert, K.
2005-01-01
An overview of recent advances in nuclear magnetic resonance (NMR) coupled with separation technologies and their application in natural product analysis is given and discussed. The different modes of LC-NMR operation are described, as well as how technical improvements assist in establishing LC-NMR
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Energy Technology Data Exchange (ETDEWEB)
Monakhova, Yulia B., E-mail: yul-monakhova@mail.ru [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Bruker Biospin GmbH, Silberstreifen, Rheinstetten 76287 (Germany); Department of Chemistry, Saratov State University, Astrakhanskaya Street 83, Saratov 410012 (Russian Federation); Godelmann, Rolf [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Hermann, Armin [Landesuntersuchungsamt -Institut für Lebensmittelchemie und Arzneimittelprüfung, Emy-Roeder-Straße 1, Mainz 55129 (Germany); Kuballa, Thomas [Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weissenburger Strasse 3, Karlsruhe 76187 (Germany); Cannet, Claire; Schäfer, Hartmut; Spraul, Manfred [Bruker Biospin GmbH, Silberstreifen, Rheinstetten 76287 (Germany); Rutledge, Douglas N. [AgroParisTech, UMR 1145, Ingénierie Procédés Aliments, 16 rue Claude Bernard, Paris F-75005 (France)
2014-06-23
Highlights: • {sup 1}H NMR profilings of 718 wines were fused with stable isotope analysis data (SNIF-NMR, {sup 18}O, {sup 13}C). • The best improvement was obtained for prediction of the geographical origin of wine. • Certain enhancement was also obtained for the year of vintage (from 88 to 97% for {sup 1}H NMR to 99% for the fused data). • Independent component analysis was used as an alternative chemometric tool for classification. - Abstract: It is known that {sup 1}H NMR spectroscopy represents a good tool for predicting the grape variety, the geographical origin, and the year of vintage of wine. In the present study we have shown that classification models can be improved when {sup 1}H NMR profiles are fused with stable isotope (SNIF-NMR, {sup 18}O, {sup 13}C) data. Variable selection based on clustering of latent variables was performed on {sup 1}H NMR data. Afterwards, the combined data of 718 wine samples from Germany were analyzed using linear discriminant analysis (LDA), partial least squares-discriminant analysis (PLS-DA), factorial discriminant analysis (FDA) and independent components analysis (ICA). Moreover, several specialized multiblock methods (common components and specific weights analysis (ComDim), consensus PCA and consensus PLS-DA) were applied to the data. The best improvement in comparison with {sup 1}H NMR data was obtained for prediction of the geographical origin (up to 100% for the fused data, whereas stable isotope data resulted only in 60–70% correct prediction and {sup 1}H NMR data alone in 82–89% respectively). Certain enhancement was obtained also for the year of vintage (from 88 to 97% for {sup 1}H NMR to 99% for the fused data), whereas in case of grape varieties improved models were not obtained. The combination of {sup 1}H NMR data with stable isotope data improves efficiency of classification models for geographical origin and vintage of wine and can be potentially used for other food products as well.
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International Nuclear Information System (INIS)
Yamamoto, Hideaki; Yamaguchi, Shuichi
1988-01-01
In an effort to examine the usefulness of 1 H-nuclear magnetic resonance (NMR) urinalysis in the diagnosis of congenital metabolic disorders, 70 kinds of urinary metabolites were analysed in relation to the diagnosis of inborn errors of amino acid and organic acid disorders. Homogated decoupling (HMG) method failed to analyze six metabolites within the undetectable range. When non-decoupling method (NON), in which the materials are dissolved in dimethyl sulfoxide, was used, the identification of signals became possible. The combination of HMG and NON methods was, therefore, considered to identify all of the metabolites. When the urine samples, which were obtained from patients with hyperglycerolemia, hyperornithinemia, glutaric acidemia type II, or glycerol kinase deficiency, were analysed by using both HMG and NON methods, abnormally increased urinary metabolites were detected. 1 H-NMR urinalysis, if used in the combination of HMG and NON methods, may allow simultanenous screening of inborn errors of metabolism of amino acid and organic acid disorders. (Namekawa, K.)
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Benchtop-NMR and MRI--a new analytical tool in drug delivery research.
Metz, Hendrik; Mäder, Karsten
2008-12-08
During the last years, NMR spectroscopy and NMR imaging (magnetic resonance imaging, MRI) have been increasingly used to monitor drug delivery systems in vitro and in vivo. However, high installation and running costs of the commonly used superconducting magnet technology limits the application range and prevents the further spread of this non-invasive technology. Benchtop-NMR (BT-NMR) relaxometry uses permanent magnets and is much less cost intensive. BT-NMR relaxometry is commonly used in the food and chemical industry, but so far scarcely used in the pharmaceutical field. The paper shows on several examples that the application field of BT-NMR relaxometry can be extended into the field of drug delivery, including the characterisation of emulsions and lipid ingredients (e.g. the amount and physicochemical state of the lipid) and the monitoring of adsorption characteristics (e.g. oil binding of porous ingredients). The most exciting possibilities of BT-NMR technology are linked with the new development of BT-instruments with imaging capability. BT-MRI examples on the monitoring of hydration and swelling of HPMC-based monolayer and double-layer tablets are shown. BT-MRI opens new MRI opportunities for the non-invasive monitoring of drug delivery processes.
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Applications of NMR spectroscopy to xenobiotic metabolism
International Nuclear Information System (INIS)
Harris, T.M.
1989-01-01
Recent years have seen high field NMR spectrometers become commonplace in research laboratories. At the same time, major advances in methodology for structural analysis have occurred, particularly notable among these being the development of two-dimensional spectroscopic techniques. Many applications have been made of NMR spectroscopy in the study of xenobiotic metabolic processes. This deals with two specific applications which have been made in the author's laboratory and involve mechanistic studies of the reactions of the carcinogens ethylene dibromide and aflatoxin with DNA
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Deuteron NMR and modelling in solid polymers
International Nuclear Information System (INIS)
Hirschinger, J.
1992-01-01
Deuteron NMR techniques are described and some recent applications to the study of rotational motions in solid polymers are reviewed. The information content and the domain of applicability of each technique are presented. Ultra-slow motions are studied in real time without any motional model consideration. For very fast motions, computer molecular dynamics simulations are shown to complement the NMR results. Experimental examples deal with the chain motion in the crystalline α-phase of poly(vinylidenefluoride) and nylon 6,6
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1H NMR spectroscopy-based interventional metabolic phenotyping
DEFF Research Database (Denmark)
Lauridsen, Michael B; Bliddal, Henning; Christensen, Robin
2010-01-01
1H NMR spectroscopy-based metabolic phenotyping was used to identify biomarkers in the plasma of patients with rheumatoid arthritis (RA). Forty-seven patients with RA (23 with active disease at baseline and 24 in remission) and 51 healthy subjects were evaluated during a one-year follow-up with a......1H NMR spectroscopy-based metabolic phenotyping was used to identify biomarkers in the plasma of patients with rheumatoid arthritis (RA). Forty-seven patients with RA (23 with active disease at baseline and 24 in remission) and 51 healthy subjects were evaluated during a one-year follow......-up with assessments of disease activity (DAS-28) and 1H NMR spectroscopy of plasma samples. Discriminant analysis provided evidence that the metabolic profiles predicted disease severity. Cholesterol, lactate, acetylated glycoprotein, and lipid signatures were found to be candidate biomarkers for disease severity.......0007). However, after 31 days of optimized therapy, the two patient groups were not significantly different (P=0.91). The metabolic profiles of both groups of RA patients were different from the healthy subjects. 1H NMR-based metabolic phenotyping of plasma samples in patients with RA is well suited...
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Covariance NMR Processing and Analysis for Protein Assignment.
Harden, Bradley J; Frueh, Dominique P
2018-01-01
During NMR resonance assignment it is often necessary to relate nuclei to one another indirectly, through their common correlations to other nuclei. Covariance NMR has emerged as a powerful technique to correlate such nuclei without relying on error-prone peak peaking. However, false-positive artifacts in covariance spectra have impeded a general application to proteins. We recently introduced pre- and postprocessing steps to reduce the prevalence of artifacts in covariance spectra, allowing for the calculation of a variety of 4D covariance maps obtained from diverse combinations of pairs of 3D spectra, and we have employed them to assign backbone and sidechain resonances in two large and challenging proteins. In this chapter, we present a detailed protocol describing how to (1) properly prepare existing 3D spectra for covariance, (2) understand and apply our processing script, and (3) navigate and interpret the resulting 4D spectra. We also provide solutions to a number of errors that may occur when using our script, and we offer practical advice when assigning difficult signals. We believe such 4D spectra, and covariance NMR in general, can play an integral role in the assignment of NMR signals.
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NMR as a probe metabolic disorders in disease and treatment
Energy Technology Data Exchange (ETDEWEB)
Yushmanov, Victor E [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Chemical Physics
1994-12-31
The effects of malignant tumors, chemical and physical factors (toxic agents, ionizing radiation) as well as of their treatment on tissue metabolism were studied by NMR imaging. The importance of NMR is highlighted since it enables to a better understanding of molecular mechanisms of diseases and therapeutic interventions, in addition to the analysis of metabolic disorders in human beings. Combined with the studies of experimental animal pathologies, may constitute a base for new types of NMR-diagnosis in vivo 10 refs.
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Patch size effects on plant species decline in an experimentally fragmented landscape.
Collins, Cathy D; Holt, Robert D; Foster, Bryan L
2009-09-01
Understanding local and global extinction is a fundamental objective of both basic and applied ecology. Island biogeography theory (IBT) and succession theory provide frameworks for understanding extinction in changing landscapes. We explore the relative contribution of fragment size vs. succession on species' declines by examining distributions of abundances for 18 plant species declining over time in an experimentally fragmented landscape in northeast Kansas, U.S.A. If patch size effects dominate, early-successional species should persist longer on large patches, but if successional processes dominate, the reverse should hold, because in our system woody plant colonization is accelerated on large patches. To compare the patterns in abundance among patch sizes, we characterize joint shifts in local abundance and occupancy with a new metric: rank occupancy-abundance profiles (ROAPs). As succession progressed, statistically significant patch size effects emerged for 11 of 18 species. More early-successional species persisted longer on large patches, despite the fact that woody encroachment (succession) progressed faster in these patches. Clonal perennial species persisted longer on large patches compared to small patches. All species that persisted longer on small patches were annuals that recruit from the seed bank each year. The degree to which species declined in occupancy vs. abundance varied dramatically among species: some species declined first in occupancy, others remained widespread or even expanded their distribution, even as they declined in local abundance. Consequently, species exhibited various types of rarity as succession progressed. Understanding the effect of fragmentation on extinction trajectories requires a species-by-species approach encompassing both occupancy and local abundance. We propose that ROAPs provide a useful tool for comparing the distribution of local abundances among landscape types, years, and species.
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Declining Japanese Yen in the Changing International Monetary System
Directory of Open Access Journals (Sweden)
Eiji Ogawa
2017-12-01
Full Text Available The US dollar has kept as a position of key currency in the global economy in the changing international monetary system where the euro was introduced to some states of the EU in 1999. It is an evidence of inertia of the US dollar as a key currency. Our previous study (Ogawa and Muto, 2017b conducted empirical analysis to investigate effects of several events on inertia of the US dollar. One of our findings was that the introduction of the euro increased utility of euro while utility of US dollar was kept unchanged. This paper examines the effects of the global financial crisis and the euro zone crisis as well as the introduction of the euro on the utility of the Japanese yen. The introduction of the euro significantly decreased the utility of the Japanese yen. It indicates that the introduction of the euro increased the utility of the euro while reducing the utility of the Japanese yen rather than the utility of the US dollar. The utility of the Japanese yen has significantly decreased while the global financial crisis and the euro zone crisis occurred. The Japanese yen has a declining trend in terms of its utility over time in the changing international monetary system.
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Recent Advances in Multinuclear NMR Spectroscopy for Chiral Recognition of Organic Compounds
Directory of Open Access Journals (Sweden)
Márcio S. Silva
2017-02-01
Full Text Available Nuclear magnetic resonance (NMR is a powerful tool for the elucidation of chemical structure and chiral recognition. In the last decade, the number of probes, media, and experiments to analyze chiral environments has rapidly increased. The evaluation of chiral molecules and systems has become a routine task in almost all NMR laboratories, allowing for the determination of molecular connectivities and the construction of spatial relationships. Among the features that improve the chiral recognition abilities by NMR is the application of different nuclei. The simplicity of the multinuclear NMR spectra relative to 1H, the minimal influence of the experimental conditions, and the larger shift dispersion make these nuclei especially suitable for NMR analysis. Herein, the recent advances in multinuclear (19F, 31P, 13C, and 77Se NMR spectroscopy for chiral recognition of organic compounds are presented. The review describes new chiral derivatizing agents and chiral solvating agents used for stereodiscrimination and the assignment of the absolute configuration of small organic compounds.
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Studies of metal-biomolecule systems in liquids with beta-detected NMR
Walczak, Michal
2017-01-01
My internship took place within a small research team funded via the European Research Council (ERC Starting Grant: Beta-Drop NMR) at ISOLDE. It was devoted to laser spin-polarization and beta-detected NMR techniques and their future applications in chemistry and biology. I was involved in the design and tests of the beta-NMR spectrometer which will be used in the upcoming experiments. In this way I have been exposed to many topics in physics (atomic and nuclear physics), experimental techniques (vacuum technology, lasers, beta detectors, electronics, DAQ software), as well as chemistry and biology (NMR on metal ions, metal ion binding to biomolecules, quantum chemistry calculations).
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Automatic maximum entropy spectral reconstruction in NMR
International Nuclear Information System (INIS)
Mobli, Mehdi; Maciejewski, Mark W.; Gryk, Michael R.; Hoch, Jeffrey C.
2007-01-01
Developments in superconducting magnets, cryogenic probes, isotope labeling strategies, and sophisticated pulse sequences together have enabled the application, in principle, of high-resolution NMR spectroscopy to biomolecular systems approaching 1 megadalton. In practice, however, conventional approaches to NMR that utilize the fast Fourier transform, which require data collected at uniform time intervals, result in prohibitively lengthy data collection times in order to achieve the full resolution afforded by high field magnets. A variety of approaches that involve nonuniform sampling have been proposed, each utilizing a non-Fourier method of spectrum analysis. A very general non-Fourier method that is capable of utilizing data collected using any of the proposed nonuniform sampling strategies is maximum entropy reconstruction. A limiting factor in the adoption of maximum entropy reconstruction in NMR has been the need to specify non-intuitive parameters. Here we describe a fully automated system for maximum entropy reconstruction that requires no user-specified parameters. A web-accessible script generator provides the user interface to the system
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Principles of high resolution NMR in solids
Mehring, Michael
1983-01-01
The field of Nuclear Magnetic Resonance (NMR) has developed at a fascinating pace during the last decade. It always has been an extremely valuable tool to the organic chemist by supplying molecular "finger print" spectra at the atomic level. Unfortunately the high resolution achievable in liquid solutions could not be obtained in solids and physicists and physical chemists had to live with unresolved lines open to a wealth of curve fitting procedures and a vast amount of speculations. High resolution NMR in solids seemed to be a paradoxon. Broad structure less lines are usually encountered when dealing with NMR in solids. Only with the recent advent of mUltiple pulse, magic angle, cross-polarization, two-dimen sional and multiple-quantum spectroscopy and other techniques during the last decade it became possible to resolve finer details of nuclear spin interactions in solids. I have felt that graduate students, researchers and others beginning to get involved with these techniques needed a book which trea...
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DEFF Research Database (Denmark)
Østergaard, Christian Richter; Park, Eun Kyung
2015-01-01
Most studies on regional clusters focus on identifying factors and processes that make clusters grow. However, sometimes technologies and market conditions suddenly shift, and clusters decline. This paper analyses the process of decline of the wireless communication cluster in Denmark. The longit...... but being quick to withdraw in times of crisis....
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NMR characterization of pituitary tumors
International Nuclear Information System (INIS)
Osbakken, M.; Gonzales, J.; Page, R.
1984-01-01
Twelve patients (5 male, 7 female, mean age 37.9 +- 20) with pituitary tumors were extensively evaluated with NMR imaging using a 1.5K gauss resistive magnet. Saturation recovery (SR), inversion recovery (IR) and spin echo (SE) pulse sequences were used for qualitative characterization of the lesions. T/sub 1/ calculations were also performed for brain and pituitary. Tumor histology and endocrine status were correlated with NMR data. All tumors were large with suprasellar extension (6 with prolactin secretion, 6 without). Pituitary T/sub 1/'s ranged from .2 to .64, the mean T/sub 1/ being longer than that of brain (Brain = .4 +- .04; Pit = .48 +- .14). 3 patients with histological evidence of homogeneous adenomas had long T/sub 1/'s (0.58 +- .05). 3 patients with evidence of recent or old hemorhage into the pituitary had much shorter T/sub 1/'s (0.29 +- .12). There was no relationship between prolactin secretion and T/sub 1/. Qualitative T/sub 1/ and T/sub 2/ information can be obtained by using a combination of SR, IR, and SE images. Using this method in the patients, homogeneous adenomas had similar T/sub 1/'s and longer T/sub 2/'s compared to the brain, while patients with bleeds had shorter T/sub 1/'s and T/sub 2/'s. Image T/sub 1/ characteristics correlated well with the calculated T/sub 1/ values. The range of T/sub 1/ (and potentially T/sub 2/) values which occur in apparently similar lesions are most likely due to anatomical and pathophysiological variations in these lesions. It may be ultimately possible to separate different types of pathological processes based on NMR image T/sub 1/ and T/sub 2/ characteristics after careful comparative studies of NMR and histological data are completed. The combination of calculated T/sub 1/ and T/sub 2/ with image T/sub 1/ and T/sub 2/ information may also be useful in further characterization of lesions
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Poppe, Leszek; Jordan, John B; Rogers, Gary; Schnier, Paul D
2015-06-02
An important aspect in the analytical characterization of protein therapeutics is the comprehensive characterization of higher order structure (HOS). Nuclear magnetic resonance (NMR) is arguably the most sensitive method for fingerprinting HOS of a protein in solution. Traditionally, (1)H-(15)N or (1)H-(13)C correlation spectra are used as a "structural fingerprint" of HOS. Here, we demonstrate that protein fingerprint by line shape enhancement (PROFILE), a 1D (1)H NMR spectroscopy fingerprinting approach, is superior to traditional two-dimensional methods using monoclonal antibody samples and a heavily glycosylated protein therapeutic (Epoetin Alfa). PROFILE generates a high resolution structural fingerprint of a therapeutic protein in a fraction of the time required for a 2D NMR experiment. The cross-correlation analysis of PROFILE spectra allows one to distinguish contributions from HOS vs protein heterogeneity, which is difficult to accomplish by 2D NMR. We demonstrate that the major analytical limitation of two-dimensional methods is poor selectivity, which renders these approaches problematic for the purpose of fingerprinting large biological macromolecules.
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Altered Reproductive Function and Amphibian Declines
Gallipeau, Sherrie
2014-01-01
Agrochemical exposure is one of the factors that contributes to worldwide amphibian declines. Most studies that examine agrochemicals and amphibian declines focus on toxicity. However, declines are more likely caused by the sub-lethal effects of agrochemical exposure. Past emphases on the lethal effects of agrochemical exposure have overshadowed the contribution of decreased recruitment in amphibian declines. Additionally, studies that examine agrochemicals and reproductive function tend to f...
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MetAssimulo:Simulation of Realistic NMR Metabolic Profiles
Directory of Open Access Journals (Sweden)
De Iorio Maria
2010-10-01
Full Text Available Abstract Background Probing the complex fusion of genetic and environmental interactions, metabolic profiling (or metabolomics/metabonomics, the study of small molecules involved in metabolic reactions, is a rapidly expanding 'omics' field. A major technique for capturing metabolite data is 1H-NMR spectroscopy and this yields highly complex profiles that require sophisticated statistical analysis methods. However, experimental data is difficult to control and expensive to obtain. Thus data simulation is a productive route to aid algorithm development. Results MetAssimulo is a MATLAB-based package that has been developed to simulate 1H-NMR spectra of complex mixtures such as metabolic profiles. Drawing data from a metabolite standard spectral database in conjunction with concentration information input by the user or constructed automatically from the Human Metabolome Database, MetAssimulo is able to create realistic metabolic profiles containing large numbers of metabolites with a range of user-defined properties. Current features include the simulation of two groups ('case' and 'control' specified by means and standard deviations of concentrations for each metabolite. The software enables addition of spectral noise with a realistic autocorrelation structure at user controllable levels. A crucial feature of the algorithm is its ability to simulate both intra- and inter-metabolite correlations, the analysis of which is fundamental to many techniques in the field. Further, MetAssimulo is able to simulate shifts in NMR peak positions that result from matrix effects such as pH differences which are often observed in metabolic NMR spectra and pose serious challenges for statistical algorithms. Conclusions No other software is currently able to simulate NMR metabolic profiles with such complexity and flexibility. This paper describes the algorithm behind MetAssimulo and demonstrates how it can be used to simulate realistic NMR metabolic profiles with
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Decline of the counterculture in the USA in the second half of XX century
Directory of Open Access Journals (Sweden)
I. M. Barchiy
2014-06-01
Counterculture failed and began to decline, but the great amount of its values and ideals were dissolved in a general culture and were perceived by American society, including the pacifist, antiracist, feminist, green, antiglobalization youth trends. There appeared the new forms of youth social movements that were created on the sample of beatniks, hippies or the «New Left».
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NMR studies of metallic tin confined within porous matrices
International Nuclear Information System (INIS)
Charnaya, E. V.; Tien, Cheng; Lee, M. K.; Kumzerov, Yu. A.
2007-01-01
119 Sn NMR studies were carried out for metallic tin confined within synthetic opal and porous glass. Tin was embedded into nanoporous matrices in the melted state under pressure. The Knight shift for liquid confined tin was found to decrease with decreasing pore size. Correlations between NMR line shapes, Knight shift, and pore filling were observed. The melting and freezing phase transitions of tin under confinement were studied through temperature dependences of NMR signals upon warming and cooling. Melting of tin within the opal matrix agreed well with the liquid skin model suggested for small isolated particles. The influence of the pore filling on the melting process was shown
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Automated high-resolution NMR with a sample changer
International Nuclear Information System (INIS)
Wade, C.G.; Johnson, R.D.; Philson, S.B.; Strouse, J.; McEnroe, F.J.
1989-01-01
Within the past two years, it has become possible to obtain high-resolution NMR spectra using automated commercial instrumentation. Software control of all spectrometer functions has reduced most of the tedious manual operations to typing a few computer commands or even making selections from a menu. Addition of an automatic sample changer is the next natural step in improving efficiency and sample throughput; it has a significant (and even unexpected) impact on how NMR laboratories are run and how it is taught. Such an instrument makes even sophisticated experiments routine, so that people with no previous exposure to NMR can run these experiments after a training session of an hour or less. This A/C Interface examines the impact of such instrumentation on both the academic and the industrial laboratory
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129 Xe-NMR of carbon black filled elastomers
International Nuclear Information System (INIS)
Sperling-Ischinsky, K.; Veeman, W.S.
1999-01-01
It is shown that 129 Xe-NMR is a powerful tool to investigate carbon black and carbon black filled elastomers. For the carbon black material itself the 129 Xe chemical shift of xenon adsorbed at the surface of carbon black aggregates yields information about the relative average pore size of the carbon black aggregates. The experimental 129 Xe-NMR results of carbon black filled ethylene-propylene-diene (EPDM) can be explained when it is assumed that the xenon atoms in the bound EPDM fraction exchange rapidly on the NMR time scale between a state where they are adsorbed on the carbon black surface and a state in which they are absorbed in the EPDM layer. This would imply that the carbon black aggregates are not completely covered with EPDM chains. (author)
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The Evolution of Global Politics
Directory of Open Access Journals (Sweden)
George Moldeski
1995-08-01
Full Text Available The rise and decline of world powers has attracted much scholarly attention in recent years. The theory of long cycles answers parsimoniously the question: why, in the past half millenium, have Portugal, the Dutch Republic, Britain (twice, and the United States risen to global leadership while others have failed to do so? This accounts for the success, or failure, of individual states, but to explain the entire sequence we need to employ an evolutionary paradigm that proposes that each of these long cycles is one mechanism in a spectrum of global evolutionary processes. The leadership succession is an intermediate stage in the evolution og global politics, whose next likely major phase, reaching a high point later in the 21st century, will be the gradual absorption of the informal role of global leadership, when embedded in a democratic community, into a network of more formal positions within an emerging global organization of a federalist character. The conditions of that process can now be specified.
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31P Solid-state MAS NMR spectra
International Nuclear Information System (INIS)
Grobet, P.J.; Geerts, H.; Martens, J.A.; Jacobs, P.A.
1989-01-01
The structures of the silicoaluminiophosphates MCM-1 and MCM9 were characterized by 27 Al and 31 P MAS NMR. The structural identity of MCM-1 and its silicon-free homologue AlPO 4 -H 3 is demonstrated. The presence of a structural mixture in MCM-9 is confirmed. 31 P MAS NMR spectra of MCM-9 could be interpreted as a superposition of spectra of VPI-5, AlPO 4 -H 3 and SAPO-11 phases. (author). 12 refs.; 3 figs.; 1 tab
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Structural properties of carbon nanotubes derived from 13C NMR
Abou-Hamad, E.; Babaa, M.-R.; Bouhrara, M.; Kim, Y.; Saih, Y.; Dennler, S.; Mauri, F.; Basset, Jean-Marie; Goze-Bac, C.; Wå gberg, T.
2011-01-01
We present a detailed experimental and theoretical study on how structural properties of carbon nanotubes can be derived from 13C NMR investigations. Magic angle spinning solid state NMR experiments have been performed on single- and multiwalled
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Directory of Open Access Journals (Sweden)
Vitalii V Cozac
2016-11-01
Full Text Available Objective: We investigated quantitative electroencephalography (qEEG and clinical parameters as potential risk factors of severe cognitive decline in Parkinson’s disease.Methods: We prospectively investigated 37 patients with Parkinson’s disease at baseline and follow-up (after 3 years. Patients had no severe cognitive impairment at baseline. We used a summary score of cognitive tests as the outcome at follow-up. At baseline we assessed motor, cognitive, and psychiatric factors; qEEG variables (global relative median power spectra were obtained by a fully automated processing of high-resolution EEG (256-channels. We used linear regression models with calculation of the explained variance to evaluate the relation of baseline parameters with cognitive deterioration.Results: The following baseline parameters significantly predicted severe cognitive decline: global relative median power theta (4-8 Hz, cognitive task performance in executive functions and working memory.Conclusions: Combination of neurocognitive tests and qEEG improves identification of patients with higher risk of cognitive decline in PD.
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Tang, Jianwu; Luyssaert, Sebastiaan; Richardson, Andrew D; Kutsch, Werner; Janssens, Ivan A
2014-06-17
The traditional view of forest dynamics originated by Kira and Shidei [Kira T, Shidei T (1967) Jap J Ecol 17:70-87] and Odum [Odum EP (1969) Science 164(3877):262-270] suggests a decline in net primary productivity (NPP) in aging forests due to stabilized gross primary productivity (GPP) and continuously increased autotrophic respiration (Ra). The validity of these trends in GPP and Ra is, however, very difficult to test because of the lack of long-term ecosystem-scale field observations of both GPP and Ra. Ryan and colleagues [Ryan MG, Binkley D, Fownes JH (1997) Ad Ecol Res 27:213-262] have proposed an alternative hypothesis drawn from site-specific results that aboveground respiration and belowground allocation decreased in aging forests. Here, we analyzed data from a recently assembled global database of carbon fluxes and show that the classical view of the mechanisms underlying the age-driven decline in forest NPP is incorrect and thus support Ryan's alternative hypothesis. Our results substantiate the age-driven decline in NPP, but in contrast to the traditional view, both GPP and Ra decline in aging boreal and temperate forests. We find that the decline in NPP in aging forests is primarily driven by GPP, which decreases more rapidly with increasing age than Ra does, but the ratio of NPP/GPP remains approximately constant within a biome. Our analytical models describing forest succession suggest that dynamic forest ecosystem models that follow the traditional paradigm need to be revisited.
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Baker, AJ; Gonzalez, PM; Piersma, T; Niles, LJ; do Nascimento, IDS; Atkinson, PW; Clark, NA; Minton, CDT; Peck, MK; Aarts, G
2004-01-01
Most populations of migrant shorebirds around the world are in serious decline, suggesting that vital condition-dependent rates such as fecundity and annual survival are being affected globally. A striking example is the red knot (Calidris canutus rufa) population wintering in Tierra del Fuego,
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Energy solutions for CO2 emission peak and subsequent decline. Proceedings
Energy Technology Data Exchange (ETDEWEB)
Soenderberg Petersen, L; Larsen, Hans [eds.
2009-09-15
The conference focused on: 1) Future global energy development options Scenario and policy issues. 2) Measures to achieve CO2 emission peak in 2015 - 2020 and subsequent decline. 3) Renewable energy supply technologies such as bioenergy, wind and solar. 4) Centralized energy technologies such as clean coal technologies. 5) Energy conversion, energy carriers and energy storage, including fuel cells and hydrogen technologies. 6) Providing renewable energy for the transport sector. 7) Systems aspects for the various regions throughout the world. 8) End-use technologies, efficiency improvements in supply and end use. 9) Energy savings. (au)
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Proton NMR studies of functionalized nanoparticles in aqueous environments
Tataurova, Yulia Nikolaevna
Nanoscience is an emerging field that can provide potential routes towards addressing critical issues such as clean and sustainable energy, environmental remediation and human health. Specifically, porous nanomaterials, such as zeolites and mesoporous silica, are found in a wide range of applications including catalysis, drug delivery, imaging, environmental protection, and sensing. The characterization of the physical and chemical properties of nanocrystalline materials is essential to the realization of these innovative applications. The great advantage of porous nanocrystals is their increased external surface area that can control their biological, chemical and catalytic activities. Specific functional groups synthesized on the surface of nanoparticles are able to absorb heavy metals from the solution or target disease cells, such as cancer cells. In these studies, three main issues related to functionalized nanomaterials will be addressed through the application of nuclear magnetic resonance (NMR) techniques including: 1) surface composition and structure of functionalized nanocrystalline particles; 2) chemical properties of the guest molecules on the surface of nanomaterials, and 3) adsorption and reactivity of surface bound functional groups. Nuclear magnetic resonance (NMR) is one of the major spectroscopic techniques available for the characterization of molecular structure and conformational dynamics with atomic level detail. This thesis deals with the application of 1H solution state NMR to porous nanomaterial in an aqueous environment. Understanding the aqueous phase behavior of functionalized nanomaterials is a key factor in the design and development of safe nanomaterials because their interactions with living systems are always mediated through the aqueous phase. This is often due to a lack of fundamental knowledge in interfacial chemical and physical phenomena that occur on the surface of nanoparticles. The use of solution NMR spectroscopy results
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Refinement of NMR structures using implicit solvent and advanced sampling techniques.
Chen, Jianhan; Im, Wonpil; Brooks, Charles L
2004-12-15
NMR biomolecular structure calculations exploit simulated annealing methods for conformational sampling and require a relatively high level of redundancy in the experimental restraints to determine quality three-dimensional structures. Recent advances in generalized Born (GB) implicit solvent models should make it possible to combine information from both experimental measurements and accurate empirical force fields to improve the quality of NMR-derived structures. In this paper, we study the influence of implicit solvent on the refinement of protein NMR structures and identify an optimal protocol of utilizing these improved force fields. To do so, we carry out structure refinement experiments for model proteins with published NMR structures using full NMR restraints and subsets of them. We also investigate the application of advanced sampling techniques to NMR structure refinement. Similar to the observations of Xia et al. (J.Biomol. NMR 2002, 22, 317-331), we find that the impact of implicit solvent is rather small when there is a sufficient number of experimental restraints (such as in the final stage of NMR structure determination), whether implicit solvent is used throughout the calculation or only in the final refinement step. The application of advanced sampling techniques also seems to have minimal impact in this case. However, when the experimental data are limited, we demonstrate that refinement with implicit solvent can substantially improve the quality of the structures. In particular, when combined with an advanced sampling technique, the replica exchange (REX) method, near-native structures can be rapidly moved toward the native basin. The REX method provides both enhanced sampling and automatic selection of the most native-like (lowest energy) structures. An optimal protocol based on our studies first generates an ensemble of initial structures that maximally satisfy the available experimental data with conventional NMR software using a simplified
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NMR-Metabolic Methodology in the Study of GM Foods
The 1H NMR methodology used in the study of genetically modified (GM) foodstuff is discussed. The study of transgenic lettuce (Lactuca sativa cv "Luxor") over-expressing the KNAT1 gene from Arabidopsis is presented as a novel study-case. The 1H NMR metabolic profiling was carried out. Twenty-two wat...
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NMR Studies of Polymer Nanocomposites
National Research Council Canada - National Science Library
Greenbaum, Steve
2001-01-01
.... The primary tool is pulsed field gradient NMR. A static field gradient method was developed which makes possible variable pressure diffusion measurement, and the application to the important fuel cell membrane NAFION constitute the first results...
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Multinuclear MAS NMR studies on coked zeolites H-ZSM-5
International Nuclear Information System (INIS)
Ernst, H.; Freude, D.; Hunger, M.; Pfeifer, H.
1991-01-01
During the cracking process carbonaceous materials are deposited on the outer or inner surface of the catalyst. These deposits are in many cases the main cause of catalyst deactivation. Magic angle spinning (MAS) NMR investigations and catalytic n-hexane cracking were carried out on H-ZSM-5 zeolites after a mild hydrothermal de-alumination. By 13 C CP MAS NMR it could be shown that the enhanced catalytic activity does not enhance the coke formation and that the chemical nature of these deposits is essentially aromatic. From 1 H MAS NMR studies performed on shallow-bed activated sealed samples and 27 Al and 29 Si MAS NMR on rehydrated samples it follows that for high coke concentrations the catalyst deactivation is caused mainly by blocking of Broensted acid sites. (author). 27 refs.; 3 figs.; 2 tabs
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PDBStat: a universal restraint converter and restraint analysis software package for protein NMR
International Nuclear Information System (INIS)
Tejero, Roberto; Snyder, David; Mao, Binchen; Aramini, James M.; Montelione, Gaetano T.
2013-01-01
The heterogeneous array of software tools used in the process of protein NMR structure determination presents organizational challenges in the structure determination and validation processes, and creates a learning curve that limits the broader use of protein NMR in biology. These challenges, including accurate use of data in different data formats required by software carrying out similar tasks, continue to confound the efforts of novices and experts alike. These important issues need to be addressed robustly in order to standardize protein NMR structure determination and validation. PDBStat is a C/C++ computer program originally developed as a universal coordinate and protein NMR restraint converter. Its primary function is to provide a user-friendly tool for interconverting between protein coordinate and protein NMR restraint data formats. It also provides an integrated set of computational methods for protein NMR restraint analysis and structure quality assessment, relabeling of prochiral atoms with correct IUPAC names, as well as multiple methods for analysis of the consistency of atomic positions indicated by their convergence across a protein NMR ensemble. In this paper we provide a detailed description of the PDBStat software, and highlight some of its valuable computational capabilities. As an example, we demonstrate the use of the PDBStat restraint converter for restrained CS-Rosetta structure generation calculations, and compare the resulting protein NMR structure models with those generated from the same NMR restraint data using more traditional structure determination methods. These results demonstrate the value of a universal restraint converter in allowing the use of multiple structure generation methods with the same restraint data for consensus analysis of protein NMR structures and the underlying restraint data
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PDBStat: a universal restraint converter and restraint analysis software package for protein NMR
Energy Technology Data Exchange (ETDEWEB)
Tejero, Roberto [Rutgers, The State University of New Jersey, Center for Advanced Biotechnology and Medicine (United States); Snyder, David [William Paterson University, Department of Chemistry (United States); Mao, Binchen; Aramini, James M.; Montelione, Gaetano T., E-mail: guy@cabm.rutgers.edu [Rutgers, The State University of New Jersey, Center for Advanced Biotechnology and Medicine (United States)
2013-08-15
The heterogeneous array of software tools used in the process of protein NMR structure determination presents organizational challenges in the structure determination and validation processes, and creates a learning curve that limits the broader use of protein NMR in biology. These challenges, including accurate use of data in different data formats required by software carrying out similar tasks, continue to confound the efforts of novices and experts alike. These important issues need to be addressed robustly in order to standardize protein NMR structure determination and validation. PDBStat is a C/C++ computer program originally developed as a universal coordinate and protein NMR restraint converter. Its primary function is to provide a user-friendly tool for interconverting between protein coordinate and protein NMR restraint data formats. It also provides an integrated set of computational methods for protein NMR restraint analysis and structure quality assessment, relabeling of prochiral atoms with correct IUPAC names, as well as multiple methods for analysis of the consistency of atomic positions indicated by their convergence across a protein NMR ensemble. In this paper we provide a detailed description of the PDBStat software, and highlight some of its valuable computational capabilities. As an example, we demonstrate the use of the PDBStat restraint converter for restrained CS-Rosetta structure generation calculations, and compare the resulting protein NMR structure models with those generated from the same NMR restraint data using more traditional structure determination methods. These results demonstrate the value of a universal restraint converter in allowing the use of multiple structure generation methods with the same restraint data for consensus analysis of protein NMR structures and the underlying restraint data.
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An extrapolation scheme for solid-state NMR chemical shift calculations
Nakajima, Takahito
2017-06-01
Conventional quantum chemical and solid-state physical approaches include several problems to accurately calculate solid-state nuclear magnetic resonance (NMR) properties. We propose a reliable computational scheme for solid-state NMR chemical shifts using an extrapolation scheme that retains the advantages of these approaches but reduces their disadvantages. Our scheme can satisfactorily yield solid-state NMR magnetic shielding constants. The estimated values have only a small dependence on the low-level density functional theory calculation with the extrapolation scheme. Thus, our approach is efficient because the rough calculation can be performed in the extrapolation scheme.
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International Nuclear Information System (INIS)
Dolenc, Jozica; Missimer, John H.; Steinmetz, Michel O.; Gunsteren, Wilfred F. van
2010-01-01
The C-terminal trigger sequence is essential in the coiled-coil formation of GCN4-p1; its conformational properties are thus of importance for understanding this process at the atomic level. A solution NMR model structure of a peptide, GCN4p16-31, encompassing the GCN4-p1 trigger sequence was proposed a few years ago. Derived using a standard single-structure refinement protocol based on 172 nuclear Overhauser effect (NOE) distance restraints, 14 hydrogen-bond and 11 φ torsional-angle restraints, the resulting set of 20 NMR model structures exhibits regular α-helical structure. However, the set slightly violates some measured NOE bounds and does not reproduce all 15 measured 3 J(H N -H Cα )-coupling constants, indicating that different conformers of GCN4p16-31 might be present in solution. With the aim to resolve structures compatible with all NOE upper distance bounds and 3 J-coupling constants, we executed several structure refinement protocols employing unrestrained and restrained molecular dynamics (MD) simulations with two force fields. We find that only configurational ensembles obtained by applying simultaneously time-averaged NOE distance and 3 J-coupling constant restraining with either force field reproduce all the experimental data. Additionally, analyses of the simulated ensembles show that the conformational variability of GCN4p16-31 in solution admitted by the available set of 187 measured NMR data is larger than represented by the set of the NMR model structures. The conformations of GCN4p16-31 in solution differ in the orientation not only of the side-chains but also of the backbone. The inconsistencies between the NMR model structures and the measured NMR data are due to the neglect of averaging effects and the inclusion of hydrogen-bond and torsional-angle restraints that have little basis in the primary, i.e. measured NMR data.
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Dolenc, Jozica; Missimer, John H; Steinmetz, Michel O; van Gunsteren, Wilfred F
2010-07-01
The C-terminal trigger sequence is essential in the coiled-coil formation of GCN4-p1; its conformational properties are thus of importance for understanding this process at the atomic level. A solution NMR model structure of a peptide, GCN4p16-31, encompassing the GCN4-p1 trigger sequence was proposed a few years ago. Derived using a standard single-structure refinement protocol based on 172 nuclear Overhauser effect (NOE) distance restraints, 14 hydrogen-bond and 11 phi torsional-angle restraints, the resulting set of 20 NMR model structures exhibits regular alpha-helical structure. However, the set slightly violates some measured NOE bounds and does not reproduce all 15 measured (3)J(H(N)-H(Calpha))-coupling constants, indicating that different conformers of GCN4p16-31 might be present in solution. With the aim to resolve structures compatible with all NOE upper distance bounds and (3)J-coupling constants, we executed several structure refinement protocols employing unrestrained and restrained molecular dynamics (MD) simulations with two force fields. We find that only configurational ensembles obtained by applying simultaneously time-averaged NOE distance and (3)J-coupling constant restraining with either force field reproduce all the experimental data. Additionally, analyses of the simulated ensembles show that the conformational variability of GCN4p16-31 in solution admitted by the available set of 187 measured NMR data is larger than represented by the set of the NMR model structures. The conformations of GCN4p16-31 in solution differ in the orientation not only of the side-chains but also of the backbone. The inconsistencies between the NMR model structures and the measured NMR data are due to the neglect of averaging effects and the inclusion of hydrogen-bond and torsional-angle restraints that have little basis in the primary, i.e. measured NMR data.
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Development of Two-Dimensional NMR
Indian Academy of Sciences (India)
Home; Journals; Resonance – Journal of Science Education; Volume 20; Issue 11. Development of Two-Dimensional NMR: Strucure Determination of Biomolecules in Solution. Anil Kumar. General Article Volume 20 Issue 11 November 2015 pp 995-1002 ...
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Fourier transform and its application to 1D and 2D NMR
International Nuclear Information System (INIS)
Canet, D.
1988-01-01
In this review article, the following points are developed: Pulsed NMR and Fourier transform; Fourier transform and two-dimensional spectroscopy; Mathematical properties of Fourier transform; Fourier transform of a sine function- one dimensional NMR; Fourier transform of a product of sine functions - two-dimensional NMR; Data manipulations in the time domain; Numerical Fourier transform [fr
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Quantum theory of NMR adiabatic pulses and their applications
International Nuclear Information System (INIS)
Ke, Y.
1993-01-01
Recently explosive developments of in vivo NMR spectroscopy (NMRS) and imaging (NMRI) in biological and medical sciences have resulted in the establishment of NMR as one of the most advanced major technique in life sciences. These developments have created huge demands for a variety of NMR adiabatic pulses with play a very important role in NMR experiments in vivo. In order to develop new NMR adiabatic pulses, a rigorous systematical quantum theory for this kind of pulses is greatly needed. Providing such a theory is one of the important goals of this dissertation. Quantum density matrix theory and product operator method have been used throughout this dissertation. Another goal, which is the major goal of this thesis research, is to use the quantum theory as a guide to develop new NMR adiabatic pulses and their applications. To fill this goal, a technique to construct a new type of adiabatic pulses, narrow band selective adiabatic pulses, has been invented, which is described through the example of constructing an adiabatic DANTE inversion pulse. This new adiabatic pulse is the first narrow band selective adiabatic pulses: Adiabatic homonuclear and heteronuclear spectral editing sequences. Unique to the first pulse sequence is a B 1 -field filter which is built by using two non-refocusing adiabatic full passage pulses to refocus the wanted signal and dephase unwanted signals. This extra filter greatly enhance the editing efficiency. Unlike commonly used heteronuclear spectral editing sequences which depend on the polarization transfer or spectral subtraction by phase cycling techniques, the second pulse sequences accomplishes the editing of heteronuclear J-coupled signals based on the fact that this sequence is transparent to the uncoupled spins and is equivalent a 90 degrees excitation pulse to the heteronuclear J-coupled spins. Experimental results have confirmed the ability of spectral editing with these two new sequences
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Pulliam, Curtis R.; Pfeiffer, William F.; Thomas, Alyssa C.
2015-01-01
This paper describes a first-year general chemistry laboratory that uses NMR spectroscopy and model building to emphasize molecular shape and structure. It is appropriate for either a traditional or an atoms-first curriculum. Students learn the basis of structure and the use of NMR data through a cooperative learning hands-on laboratory…
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PR-CALC: A Program for the Reconstruction of NMR Spectra from Projections
International Nuclear Information System (INIS)
Coggins, Brian E.; Zhou Pei
2006-01-01
Projection-reconstruction NMR (PR-NMR) has attracted growing attention as a method for collecting multidimensional NMR data rapidly. The PR-NMR procedure involves measuring lower-dimensional projections of a higher-dimensional spectrum, which are then used for the mathematical reconstruction of the full spectrum. We describe here the program PR-CALC, for the reconstruction of NMR spectra from projection data. This program implements a number of reconstruction algorithms, highly optimized to achieve maximal performance, and manages the reconstruction process automatically, producing either full spectra or subsets, such as regions or slices, as requested. The ability to obtain subsets allows large spectra to be analyzed by reconstructing and examining only those subsets containing peaks, offering considerable savings in processing time and storage space. PR-CALC is straightforward to use, and integrates directly into the conventional pipeline for data processing and analysis. It was written in standard C+ + and should run on any platform. The organization is flexible, and permits easy extension of capabilities, as well as reuse in new software. PR-CALC should facilitate the widespread utilization of PR-NMR in biomedical research
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Amphibian decline and extinction: what we know and what we need to learn.
Collins, James P
2010-11-01
For over 350 million yr, thousands of amphibian species have lived on Earth. Since the 1980s, amphibians have been disappearing at an alarming rate, in many cases quite suddenly. What is causing these declines and extinctions? In the modern era (post 1500) there are 6 leading causes of biodiversity loss in general, and all of these acting alone or together are responsible for modern amphibian declines: commercial use; introduced/exotic species that compete with, prey on, and parasitize native frogs and salamanders; land use change; contaminants; climate change; and infectious disease. The first 3 causes are historical in the sense that they have been operating for hundreds of years, although the rate of change due to each accelerated greatly after about the mid-20th century. Contaminants, climate change, and emerging infectious diseases are modern causes suspected of being responsible for the so-called 'enigmatic decline' of amphibians in protected areas. Introduced/exotic pathogens, land use change, and infectious disease are the 3 causes with a clear role in amphibian decline as well as extinction; thus far, the other 3 causes are only implicated in decline and not extinction. The present work is a review of the 6 causes with a focus on pathogens and suggested areas where new research is needed. Batrachochytrium dendrobatidis (Bd) is a chytrid fungus that is an emerging infectious disease causing amphibian population decline and species extinction. Historically, pathogens have not been seen as a major cause of extinction, but Bd is an exception, which is why it is such an interesting, important pathogen to understand. The late 20th and early 21st century global biodiversity loss is characterized as a sixth extinction event. Amphibians are a striking example of these losses as they disappear at a rate that greatly exceeds historical levels. Consequently, modern amphibian decline and extinction is a lens through which we can view the larger story of biodiversity
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Recent trends on NMR imaging in UK and USA
Energy Technology Data Exchange (ETDEWEB)
Endo, Masahiro [National Inst. of Radiological Sciences, Chiba (Japan)
1981-12-01
The development of nuclear magnetic resonance (NMR) by major research centers and manufacturers is reviewed. The spin warp method is used at Aberdeen University, and the T1 images of esophageal cancer and hepatic metastasis obtained by this method are shown. The Moore group at Nottingham University developed an instrument to scan the head region, and it produces spatial resolution comparable to x-ray computed tomography. The transverse image of the thorax obtained by the QED-80 developed by FONAR (U.S.A.) is shown. It uses field focusing NMR, and can measure spin density, T1, T2 and NMR spectrum, but its precision is slightly lowered because fewer proton spins are activated. These methods all measure the proton distribution in vivo, but with the TMR developed by Oxford Research Co. (U.K.) high resolution spectra of phosphorus 31 compounds can be obtained. The NMR spectra obtained for the phosphorus compounds in the muscle is shown. The rate of the phosphorus compounds such as ATP, ADP creatine phosphate and inorganic phosphate are markedly changed by exercise or depending on the blood flow.
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Nondestructive NMR technique for moisture determination in radioactive materials
International Nuclear Information System (INIS)
Aumeier, S.; Gerald, R.E. II; Growney, E.; Nunez, L.; Kaminski, M.
1998-01-01
This progress report focuses on experimental and computational studies used to evaluate nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI) for detecting, quantifying, and monitoring hydrogen and other magnetically active nuclei ( 3 H, 3 He, 239 Pu, 241 Pu) in Spent nuclear fuels and packaging materials. The detection of moisture by using a toroid cavity NMR imager has been demonstrated in SiO 2 and UO 2 systems. The total moisture was quantified by means of 1 H NMR detection of H 2 O with a sensitivity of 100 ppm. In addition, an MRI technique that was used to determine the moisture distribution also enabled investigators to discriminate between bulk and stationary water sorbed on the particles. This imaging feature is unavailable in any other nondestructive assay (NDA) technique. Following the initial success of this program, the NMR detector volume was scaled up from the original design by a factor of 2000. The capacity of this detector exceeds the size specified by DOE-STD-3013-96
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Quantitative produced water analysis using mobile 1H NMR
International Nuclear Information System (INIS)
Wagner, Lisabeth; Fridjonsson, Einar O; May, Eric F; Stanwix, Paul L; Graham, Brendan F; Carroll, Matthew R J; Johns, Michael L; Kalli, Chris
2016-01-01
Measurement of oil contamination of produced water is required in the oil and gas industry to the (ppm) level prior to discharge in order to meet typical environmental legislative requirements. Here we present the use of compact, mobile 1 H nuclear magnetic resonance (NMR) spectroscopy, in combination with solid phase extraction (SPE), to meet this metrology need. The NMR hardware employed featured a sufficiently homogeneous magnetic field, such that chemical shift differences could be used to unambiguously differentiate, and hence quantitatively detect, the required oil and solvent NMR signals. A solvent system consisting of 1% v/v chloroform in tetrachloroethylene was deployed, this provided a comparable 1 H NMR signal intensity for the oil and the solvent (chloroform) and hence an internal reference 1 H signal from the chloroform resulting in the measurement being effectively self-calibrating. The measurement process was applied to water contaminated with hexane or crude oil over the range 1–30 ppm. The results were validated against known solubility limits as well as infrared analysis and gas chromatography. (paper)
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International Nuclear Information System (INIS)
Zhou Pei; Wagner, Gerhard
2010-01-01
Although the rapid progress of NMR technology has significantly expanded the range of NMR-trackable systems, preparation of NMR-suitable samples that are highly soluble and stable remains a bottleneck for studies of many biological systems. The application of solubility-enhancement tags (SETs) has been highly effective in overcoming solubility and sample stability issues and has enabled structural studies of important biological systems previously deemed unapproachable by solution NMR techniques. In this review, we provide a brief survey of the development and successful applications of the SET strategy in biomolecular NMR. We also comment on the criteria for choosing optimal SETs, such as for differently charged target proteins, and recent new developments on NMR-invisible SETs.
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Realization of seven-qubit Deutsch-Jozsa algorithm on NMR quantum computer
International Nuclear Information System (INIS)
Wei Daxiu; Yang Xiaodong; Luo Jun; Sun Xianping; Zeng Xizhi; Liu Maili; Ding Shangwu
2002-01-01
Recent years, remarkable progresses in experimental realization of quantum information have been made, especially based on nuclear magnetic resonance (NMR) theory. In all quantum algorithms, Deutsch-Jozsa algorithm has been widely studied. It can be realized on NMR quantum computer and also can be simplified by using the Cirac's scheme. At first the principle of Deutsch-Jozsa quantum algorithm is analyzed, then the authors implement the seven-qubit Deutsch-Jozsa algorithm on NMR quantum computer
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A fragment separator at LBL for beta-NMR experiment
International Nuclear Information System (INIS)
Matsuta, K.; Ozawa, A.; Nojiri, Y.; Minamisono, T.; Fukuda, M.; Kitagawa, A.; Ohtsubo, T.; Momota, S.; Fukuda, S.; Matsuo, Y.; Takechi, H.; Minami, I.; Sugimoto, K.; Tanihata, I.; Omata, K.; Alonso, J.R.; Krebs, G.F.; Symons, T.J.M.
1992-03-01
The Beam 44 fragment separator was built at the Bevalac of LBL for NMR studies of beta emitting nuclei. 37 K, 39 Ca, and 43 Ti fragments originating from 40 Ca and 46 Ti primary beams were separated by the separator for NMR studies on these nuclei. Nuclear spin polarization was created in 39 Ca and 43 Ti using the tilted foil technique (TFT), and the magnetic moment of 43 Ti was deduced. Fragment polarization was measured for 37 K and 39 Ca emitted to finite deflection angles. The Beam 44 fragment separator in combination with a proper polarization technique, such as TFT or fragment polarization, has been very effective for such NMR studies
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NMR-Metabolic Methodology in the Study of GM Foods
Directory of Open Access Journals (Sweden)
Irene D’Amico
2010-01-01
Full Text Available The 1H-NMR methodology used in the study of genetically modified (GM foods is discussed. Transgenic lettuce (Lactuca sativa cv "Luxor" over-expressing the Arabidopsis KNAT1 gene is presented as a case study. Twenty-two water-soluble metabolites (amino acids, organic acids, sugars present in leaves of conventional and GM lettuce were monitored by NMR and quantified at two developmental stages. The NMR spectra did not reveal any difference in metabolite composition between the GM lettuce and the wild type counterpart. Statistical analyses of metabolite variables highlighted metabolism variation as a function of leaf development as well as the transgene. A main effect of the transgene was in altering sugar metabolism.
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Achieving High Accuracy in Calculations of NMR Parameters
DEFF Research Database (Denmark)
Faber, Rasmus
quantum chemical methods have been developed, the calculation of NMR parameters with quantitative accuracy is far from trivial. In this thesis I address some of the issues that makes accurate calculation of NMR parameters so challenging, with the main focus on SSCCs. High accuracy quantum chemical......, but no programs were available to perform such calculations. As part of this thesis the CFOUR program has therefore been extended to allow the calculation of SSCCs using the CC3 method. CC3 calculations of SSCCs have then been performed for several molecules, including some difficult cases. These results show...... vibrations must be included. The calculation of vibrational corrections to NMR parameters has been reviewed as part of this thesis. A study of the basis set convergence of vibrational corrections to nuclear shielding constants has also been performed. The basis set error in vibrational correction...
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NMR characteristics of rat mammary tumors
International Nuclear Information System (INIS)
Osbakken, M.; Kreider, J.; Taczanowsky, P.
1984-01-01
12 rats were injected intradermally with 13762A rat mammary adenocarcinoma (1 x 10/sup 6/ cells). 3 rats died before completion of the study and 2 rat had tumor regression; the first 3 were excluded from data analysis. NMR imaging with a 1.5K gauss resistive magnet at 2, 3, 4, and 5 weeks after injection demonstrated increasing tumor mass. Saturation recovery (SR), inversion recovery (IR), and spin echo (SE) pulse sequence images and T/sub 1/ calculation were done for tumor characterization. (Tumor size was too small to identify at 2 weeks.) 3 rats were sacrificed after the last 3 imaging periods for histological studies, done to distinguish solid tumor mass from necrosis. Planimetry of tumor areas showed that as tumors grew in size, the ratio of necrotic area to area of solid tumor increased (week 3 = .3 +- .11; week 4 = .45 +- .07; week 5 = .51 +- 05); simultaneous calculated T/sub 1/ values also increased (week 3 = .35 +- .15; week 4 = .45 +- .06; week 5 = .42 +- 03). Qualitative NMR image T/sub 1/ values also increased as evidenced by progression of SR and IR tumor image intensity from very bright compared to the rest of the body at week 3 to less intense than other structures at week 5. These findings indicate that change in T/sub 1/ may be secondary to the pathophysiological change in the tumor (the increasing in necrosis, associated with increased free water). Thus, the range of T/sub 1/ values obtained in tumors in this study (and in previous studies) may be due to change in tumor physiology and anatomy. Careful correlation of histological with NMR data may allow ultimate use of NMR relaxation characteristics for determination of the physiological state of tumors
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Additivity, redundancy, and complementarity between structural information from NMR and SAXS data
International Nuclear Information System (INIS)
Kojima, Masaki; Nonaka, Takamasa; Morimoto, Yasumasa; Nakagawa, Takashi; Yanagi, Shigeru; Kihara, Hiroshi
2009-01-01
At present protein structure in solution is determined by restrained molecular dynamics with distance restraints mainly derived from NMR. Although the small-angle X-ray scattering (SAXS) method also confers the structural information, its content is too small to determine the structure by itself. We previously developed a new algorithm that refines the protein structure by restrained molecular dynamics with SAXS constrains. In the present study we performed the protein structure calculation by restrained molecular dynamics with both NMR and SAXS constraints, in order to elucidate the essential structural information that defines the protein architecture. We used RNase T1 as a model protein, which has already been determined by NMR alone. At first we added SAXS constraints (h -1 ) into the original NMR-derived restraints for the calculation. The quality of the structure ensemble was significantly increased. Next we removed the original NMR restraints randomly in order to estimate the redundancy among the NMR-derived information. The essential topology of the resultant structures was hardly changed until the restraints were reduced below the half. Then we added the SAXS constraints into the remaining NMR restraints to expect they could complement the lost structural information. However, the structure was not recovered properly. By removing various types of structural information exclusively from the original NMR data set, we investigated whether the SAXS constraints could complement some kinds of structural information. The results showed that the SAXS could complement the tertiary structure to some extent while it could not secondary structure. (author)
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Scheper, J.A.; Reemer, M.; Kats, van R.J.M.; Ozinga, W.A.; Linden, van der G.T.J.; Schaminee, J.H.J.; Siepel, H.; Kleijn, D.
2014-01-01
Evidence for declining populations of both wild and managed bees has raised concern about a potential global pollination crisis. Strategies to mitigate bee loss generally aim to enhance floral resources. However, we do not really know whether loss of preferred floral resources is the key driver of
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Nation state and the challenge of globalization: Project draft
Directory of Open Access Journals (Sweden)
Obrenović Zoran G.
2002-01-01
Full Text Available This project draft discusses the issues facing a nation state in the dynamic processes of globalization. First, the term globalization is tentatively defined as a decentralized process of condensation and homogenization of space and time. Then, the ambivalent structure of the globalization discourse, i.e. its semantic and pragmatic dimensions, are shown. The neo-liberal viewpoint is explored of the erosion and weakening of the nation state within the global capitalist power, both in terms of its (state's traditional functions, and in terms of its internal and external sovereignty. Against the neo-liberal thesis about the decline of the nation state many empirical arguments have been offered. Some of these are presented in this text. The main point of this argumentation consists in a general view that the decline of the nation state is strongly linked with the process of globalization. In view of the critical argumentation included in the paper, it is argued that in the environment of global processes only the societies which have a strong state behind them have a chance to succeed. Politics, not economy, still dominates international relations. Emphasis on state politics opens a new perspective in discussing the process of globalization. Current globalization processes cannot be judged accurately unless geopolitical interests and the changing balance of world power are understood. Finally, the paper points to the ideological nature of the neo-liberal discourse of globalization, questioning another basic assumption of the latter, namely, the idea that the process of globalization is at the same time a process of emancipation. By challenging the positing of a necessary link between globalization and emancipation we formulate a position that allows for a normative critique of current processes.
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ULF-NMR system using HTS-SQUID and permanent magnet
Energy Technology Data Exchange (ETDEWEB)
Fukumoto, Shohei, E-mail: hatukade@ens.tut.ac.jp [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan); Tsunaki, Shingo; Chigasaki, Takumi; Hatsukade, Yoshimi; Tanaka, Saburo [Toyohashi University of Technology, 1-1 Hibarigaoka, Tempaku-cho, Toyohashi, Aichi 441-8580 (Japan)
2013-01-15
Highlights: ► A permanent magnet was introduced into a ULF SQUID-NMR system for polarization. ► An instrument to transfer a sample in the magnet to under a SQUID was implemented. ► An AC pulse coil was also introduced to apply a π/2 pulse to obtain an NMR signal. ► A {sup 1}H NMR signal was measured while applying a static field of 45 μT. ► The signal to noise ratio of the {sup 1}H NMR signal was about 100. -- Abstract: We have constructed an ultra-low field (ULF) nuclear magnetic resonance (NMR)/magnetic resonance imaging (MRI) system using an HTS-rf-SQUID and room-temperature electromagnets in a magnetically shielded room (MSR). In this study, in order to improve the signal to noise ratio (S/N) of the system, we introduced a permanent magnet instead of the electromagnet for pre-polarizing the sample to enhance the pre-polarizing field (B{sub p}). The cylindrical permanent magnet of 270 mT was used to magnetize a water sample for several seconds outside the MSR and about 1.5 m away from the SQUID. We constructed an instrument to transfer the magnetized sample from the permanent magnet to under the SQUID in 0.5 s. Since the non-adiabatic condition cannot be kept in such sample transfer scheme, an AC pulse coil to apply an AC pulse field B{sub AC} to rotate the magnetization moments for π/2 was introduced to measure a free induction decay (FID) signal from the sample. By this system, we obtained an NMR signal from the water sample of 10 ml while applying a static field of 45 μT and π/2 pulse after the transfer. The S/N of the NMR spectrum was about 100 by a single shot, which was 10 times larger than that obtained with the electromagnet of 32 mT. In addition, we demonstrated the measurements of the longitudinal relaxation time (T{sub 1}) and the spin echo signal of the water sample by the system.
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Puchades-Carrasco, Leonor; Palomino-Schätzlein, Martina; Pérez-Rambla, Clara; Pineda-Lucena, Antonio
2016-05-01
Metabolomics, a systems biology approach focused on the global study of the metabolome, offers a tremendous potential in the analysis of clinical samples. Among other applications, metabolomics enables mapping of biochemical alterations involved in the pathogenesis of diseases, and offers the opportunity to noninvasively identify diagnostic, prognostic and predictive biomarkers that could translate into early therapeutic interventions. Particularly, metabolomics by Nuclear Magnetic Resonance (NMR) has the ability to simultaneously detect and structurally characterize an abundance of metabolic components, even when their identities are unknown. Analysis of the data generated using this experimental approach requires the application of statistical and bioinformatics tools for the correct interpretation of the results. This review focuses on the different steps involved in the metabolomics characterization of biofluids for clinical applications, ranging from the design of the study to the biological interpretation of the results. Particular emphasis is devoted to the specific procedures required for the processing and interpretation of NMR data with a focus on the identification of clinically relevant biomarkers. © The Author 2015. Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.
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Method of detecting cancer by measuring lipid-peroxidation using NMR
International Nuclear Information System (INIS)
Fossel, E.T.
1992-01-01
A technique and an apparatus are disclosed for the detection of cancer using nuclear magnetic resonance (NMR). Specifically, NMR parameters for protons of lipid methyl and/or methylene groups are determined and compared against a corresponding value for healthy patients. Suppression of the water proton signal is employed where necessary in order to obtain a suitable spectrum for the non-water component protons. In the event that a positive reading is obtained, the level of plasma triglycerides is determined and if it is high, the patient's bodily fluid sample is further subjected to second nuclear magnetic spectroscopy. The area or the intensity of the portion correlating to 2.0 and 2.8 ppm of the resonance line generated in the second NMR is measured which discriminates between true and false positive results from the proton NMR reading and determines the presence or absence of cancer in the patient
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International Nuclear Information System (INIS)
Buster, D.C.
1988-01-01
A technique has been developed to investigate the antibiotic facilitated transmembrane transport of monovalent cations using 23 Na and 7 Li Nuclear Magnetic Resonance spectroscopy. The initial portion of this thesis outlines the production and characterization of a model lipid system amenable to the NMR detection of cation transport. Large unilamellar vesicles (LUV) have been prepared from a 4:1 mixture of phosphatidylcholine and phosphatidylglycerol. The presence of the anionic chemical shift reagent dysprosium (III) tripolyphosphate, either inside or outside of the vesicles, allows for the spectroscopic separation of the NMR resonances arising from the inter- and extravesicular cation pools. The cation transporting properties of the channel-forming pentadecapeptide, gramicidin D, have been studied using the NMR technique
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Structural properties of carbon nanotubes derived from 13C NMR
Abou-Hamad, E.
2011-10-10
We present a detailed experimental and theoretical study on how structural properties of carbon nanotubes can be derived from 13C NMR investigations. Magic angle spinning solid state NMR experiments have been performed on single- and multiwalled carbon nanotubes with diameters in the range from 0.7 to 100 nm and with number of walls from 1 to 90. We provide models on how diameter and the number of nanotube walls influence NMR linewidth and line position. Both models are supported by theoretical calculations. Increasing the diameter D, from the smallest investigated nanotube, which in our study corresponds to the inner nanotube of a double-walled tube to the largest studied diameter, corresponding to large multiwalled nanotubes, leads to a 23.5 ppm diamagnetic shift of the isotropic NMR line position δ. We show that the isotropic line follows the relation δ = 18.3/D + 102.5 ppm, where D is the diameter of the tube and NMR line position δ is relative to tetramethylsilane. The relation asymptotically tends to approach the line position expected in graphene. A characteristic broadening of the line shape is observed with the increasing number of walls. This feature can be rationalized by an isotropic shift distribution originating from different diamagnetic shielding of the encapsulated nanotubes together with a heterogeneity of the samples. Based on our results, NMR is shown to be a nondestructive spectroscopic method that can be used as a complementary method to, for example, transmission electron microscopy to obtain structural information for carbon nanotubes, especially bulk samples.
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Gonzales, Mitzi M; Insel, Philip S; Nelson, Craig; Tosun, Duygu; Mattsson, Niklas; Mueller, Susanne G; Sacuiu, Simona; Bickford, David; Weiner, Michael W; Mackin, R Scott
2017-09-01
To investigate the association between cognitive decline and cortical atrophy in individuals with mild cognitive impairment (MCI) and chronic subsyndromal symptoms of depression (SSD) over a 4-year period. Prospective cohort study. Multicenter, clinic-based. Within the Alzheimer's Disease Neuroimaging Initiative repository, the Neuropsychiatric Inventory was used to identify individuals with MCI and stable endorsement (SSD group N = 32) or no endorsement (non-SSD group N = 69) of depressive symptoms across time points. Repeated measures of cognitive outcomes, cortical atrophy, and their associations were evaluated with mixed effects models adjusting for age, education, sex, and APOE genotype. The SSD group demonstrated accelerated decline on measures of global cognition (Alzheimer Disease Assessment Scale; df = 421, t = 2.242, p = 0.025), memory (Wechsler Memory Scale-Revised Logical Memory II; df = 244, t = -2.525, p = 0.011), information processing speed (Trail Making Test Parts A [df = 421, t = 2.376, p = 0.018] and B [df = 421, t = 2.533, p = 0.012]), and semantic fluency (Category Fluency; df = 424, t = -2.418, p = 0.016), as well as accelerated frontal lobe (df = 341, t = -2.648, p = 0.008) and anterior cingulate (df = 341, t = -3.786, p confrontation naming or for rate of atrophy in any other regions. Accelerated frontal lobe and anterior cingulate atrophy was associated with cognitive decline on measures of global cognition, information processing speed, and semantic fluency (all p < 0.05), but not memory. Individuals with chronic SSD may represent an MCI subgroup that is highly vulnerable to accelerated cognitive decline, an effect that may be governed by frontal lobe and anterior cingulate atrophy. Published by Elsevier Inc.
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11B NMR study of calcium-hexaborides
International Nuclear Information System (INIS)
Mean, B.J.; Lee, K.H.; Kang, K.H.; Lee, Moohee; Rhee, J.S.; Cho, B.K.
2005-01-01
We have performed 11 B nuclear magnetic resonance (NMR) measurements to look for microscopic evidence of the ferromagnetic state in several CaB 6 single crystals. A number of 11 B NMR resonance peaks are observed with the frequency and intensity of those peaks distinctively changing depending on the angle between the crystalline axis and a magnetic field. Analyzing this behavior, we find that the electric field gradient tensor at the boron has its principal axis perpendicular to the six cubic faces with a quadrupole resonance frequency ν Q ∼600kHz. However, the satellite resonances are found to be made of two peaks. Detailed analysis of the four composite satellite peaks confirms that there are two different boron sites with slightly different ν Q 's. This suggests that the boron octahedron cages are locally distorted. However, this distortion is not directly related to ferromagnetism. Even though the magnetization data highlight the ferromagnetic hysteresis, 11 B NMR linewidth and shift data show no clear microscopic evidence of the ferromagnetic state in several different compositions of CaB 6 single crystals
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Bellot, P.-V.; Trokiner, A.; Zhdanov, Yu.; Yakubovskii, A.
1998-02-01
In this paper we show that 43Ca is a suitable NMR probe to study the properties of high-Tc superconducting oxides. In the normal state, we report the temperature and doping dependencies of the spin susceptibility measured by 43Ca NMR. In the superconducting state and more exactly in the mixed state, by analysing 43Ca NMR linewidth, we have studied the magnetic induction distribution due to the presence of vortices and deduced λ, the penetration depth. Dans cet article, on montre que l'isotope 43 du calcium est une bonne sonde RMN pour l'étude des propriétés des oxydes supraconducteurs à haute température. Dans l'état normal, par la détermination du déplacement de la raie, en fonction de la température, on accède à la variation thermique de la susceptibilité de spin. Dans l'état supraconducteur et plus particulièrement dans l'état mixte, la largeur de raie RMN permet d'étudier la distribution d'induction magnétique due à la présence des vortex et de déterminer λ, la longueur de pénétration.
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Cognitive decline over time in adults with myotonic dystrophy type 1: A 9-year longitudinal study.
Gallais, Benjamin; Gagnon, Cynthia; Mathieu, Jean; Richer, Louis
2017-01-01
Myotonic dystrophy type 1 (DM1) is an inherited neuromuscular disease with multisystemic involvement including the central nervous system. The evolution of the cognitive profile is a matter of debate, whether an eventual decline could be global or process-specific. Study aims are to describe, compare and document the clinical relevance of the progression of cognitive abilities in DM1 patients with adult and late-onset phenotypes. A total of 115 DM1 patients (90 adult; 25 late-onset) were assessed twice within a 9-year period on cognitive abilities (language, memory, visual attention, processing speed, visuoconstructive abilities and executive functions) and intellectual functioning (WAIS-R 7). A significant worsening over time was observed for verbal memory, visual attention, and processing speed. The progression in cognitive scores correlated with age and disease duration, but not with nCTG, muscular impairment nor education at baseline. Intellectual functioning remained stable. The rate of decline was higher among the late-onset phenotype than in the adult phenotype. Results showed that executive functions, language, and visual memory are impaired earlier in adult life, while verbal memory, visual attention, and processing speed decline later. Globally, results suggest an early and accelerated normal ageing process. This longitudinal study was based on the largest sample and the longest time period studied to date. These findings are highly relevant for clinical practice and genetic counselling. Copyright © 2016 Elsevier B.V. All rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Qi, Long; Alamillo, Ricardo; Elliott, William A.; Andersen, Amity; Hoyt, David W.; Walter, Eric D.; Han, Kee Sung; Washton, Nancy M.; Rioux, Robert M.; Dumesic, James A.; Scott, Susannah L.
2017-04-18
Liquid-phase processing of molecules using heterogeneous catalysts – an important strategy for obtaining renewable chemicals sustainably from biomass – involves reactions that occur at solid-liquid interfaces. In glucose isomerization catalyzed by basic faujasite zeolites, the catalytic activity depends strongly on the solvent composition: initially, it declines precipitously when water is mixed with a small amount of the organic co-solvent γ-valerolactone (GVL), then recovers as the GVL content increases. Using solid-state 13C NMR spectroscopy, we observed glucose isomers located inside the zeolite pores directly, and followed their transformations into fructose and mannose in real time. At low GVL concentrations, glucose is depleted in the zeolite pores relative to the liquid phase, while higher GVL concentrations in solution drive glucose inside the pores, resulting in up to a 32 enhancement in the local glucose concentration. Although their populations exchange rapidly, molecules present at the reactive interface experience a significantly different environment from the bulk solution.
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Mössbauer and NMR study of novel Tin(IV)-lactames
International Nuclear Information System (INIS)
Kuzmann, Erno; Szalay, Roland; Homonnay, Zoltan; Nagy, Sandor
2012-01-01
N-tributylstannylated 2-pyrrolidinone was reacted with tributyltin triflate in different molar ratios and the complex formation monitored using 1 H-NMR, 13 C-NMR and 119 Sn Mössbauer spectroscopy. Comparing the carbon NMR and tin Mössbauer results, a reaction scheme is suggested for the complexation which assumes the formation of a simultaneously O- and N-tributylstannylated pyrrolidinone cation. The formation of the only O-stannylated pyrrolidinone is also assumed to account for the non-constant Mössbauer parameters of the two tin environments in the distannylated pyrrolidinone cation when the ratio of tributyltin triflate is increased in the reaction.
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NMR studies of Na+-anion association effects in polymer electrolytes
International Nuclear Information System (INIS)
Greenbaum, S.G.; Pak, Y.S.; Wintergill, M.C.; Fontanella, J.J.
1988-01-01
23 Na nuclear magnetic resonance (NMR) measurements on poly (propylene oxide) (PPO) and siloxane based polymer electrolytes containing various sodium salts at a single nominal concentration are reported. In addition, differential scanning calorimetry (DSC) and electrical conductivity studies were carried out on the PPO materials. The NMR-determined mobile Na + concentrations and DSC results provide evidence for ionic aggregation effects which, for some samples, result in salt precipitation at elevated temperatures. 23 Na chemical shifts observed in solid state NMR due to mobile Na + -anion interactions influence ionic transport as well as the number of available carriers. (author). 19 refs.; 7 figs
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Complete 1H NMR spectral analysis of ten chemical markers of Ginkgo biloba.
Napolitano, José G; Lankin, David C; Chen, Shao-Nong; Pauli, Guido F
2012-08-01
The complete and unambiguous (1)H NMR assignments of ten marker constituents of Ginkgo biloba are described. The comprehensive (1)H NMR profiles (fingerprints) of ginkgolide A, ginkgolide B, ginkgolide C, ginkgolide J, bilobalide, quercetin, kaempferol, isorhamnetin, isoquercetin, and rutin in DMSO-d(6) were obtained through the examination of 1D (1)H NMR and 2D (1)H,(1)H-COSY data, in combination with (1)H iterative full spin analysis (HiFSA). The computational analysis of discrete spin systems allowed a detailed characterization of all the (1)H NMR signals in terms of chemical shifts (δ(H)) and spin-spin coupling constants (J(HH)), regardless of signal overlap and higher order coupling effects. The capability of the HiFSA-generated (1)H fingerprints to reproduce experimental (1)H NMR spectra at different field strengths was also evaluated. As a result of this analysis, a revised set of (1)H NMR parameters for all ten phytoconstituents was assembled. Furthermore, precise (1)H NMR assignments of the sugar moieties of isoquercetin and rutin are reported for the first time. Copyright © 2012 John Wiley & Sons, Ltd.
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Development of a superconducting bulk magnet for NMR and MRI.
Nakamura, Takashi; Tamada, Daiki; Yanagi, Yousuke; Itoh, Yoshitaka; Nemoto, Takahiro; Utumi, Hiroaki; Kose, Katsumi
2015-10-01
A superconducting bulk magnet composed of six vertically stacked annular single-domain c-axis-oriented Eu-Ba-Cu-O crystals was energized to 4.74 T using a conventional superconducting magnet for high-resolution NMR spectroscopy. Shim coils, gradient coils, and radio frequency coils for high resolution NMR and MRI were installed in the 23 mm-diameter room-temperature bore of the bulk magnet. A 6.9 ppm peak-to-peak homogeneous region suitable for MRI was achieved in the central cylindrical region (6.2 mm diameter, 9.1 mm length) of the bulk magnet by using a single layer shim coil. A 21 Hz spectral resolution that can be used for high resolution NMR spectroscopy was obtained in the central cylindrical region (1.3 mm diameter, 4 mm length) of the bulk magnet by using a multichannel shim coil. A clear 3D MR image dataset of a chemically fixed mouse fetus with (50 μm)(3) voxel resolution was obtained in 5.5 h. We therefore concluded that the cryogen-free superconducting bulk magnet developed in this study is useful for high-resolution desktop NMR, MRI and mobile NMR device. Copyright © 2015 Elsevier Inc. All rights reserved.
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In situ viscosity of oil sands using low field NMR
International Nuclear Information System (INIS)
Bryan, J.; Moon, D.; Kantzas, A.
2005-01-01
In heavy oil and bitumen reservoirs, oil viscosity is a vital piece of information that will have great bearing on the chosen EOR scheme and the recovery expected. Prediction of in situ viscosity with a logging tool would he very beneficial in reservoir characterization and exploitation design. Low field NMR is a technology that has shown great potential as a tool for characterizing hydrocarbon properties in heavy oil and bitumen reservoirs. An oil viscosity correlation has previously been developed that is capable of providing order of magnitude viscosity estimates for a wide range of oils taken from various fields in Alberta. This paper presents tuning procedures to improve the NMR predictions for different viscosity ranges, and extends the NMR viscosity model to in situ heavy oil in unconsolidated sands. The results of this work show that the NMR oil peak can be de-convoluted from the in situ signals of the oil and water, and the bulk viscosity correlation that was developed for bulk oils can he applied to predict the in situ oil viscosity. These results can be translated to an NMR logging tool algorithm, allowing for in situ measurements of oil viscosity at the proper reservoir conditions. (author)
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Novel NMR tools to study structure and dynamics of biomembranes.
Gawrisch, Klaus; Eldho, Nadukkudy V; Polozov, Ivan V
2002-06-01
Nuclear magnetic resonance (NMR) studies on biomembranes have benefited greatly from introduction of magic angle spinning (MAS) NMR techniques. Improvements in MAS probe technology, combined with the higher magnetic field strength of modern instruments, enables almost liquid-like resolution of lipid resonances. The cross-relaxation rates measured by nuclear Overhauser enhancement spectroscopy (NOESY) provide new insights into conformation and dynamics of lipids with atomic-scale resolution. The data reflect the tremendous motional disorder in the lipid matrix. Transfer of magnetization by spin diffusion along the proton network of lipids is of secondary relevance, even at a long NOESY mixing time of 300 ms. MAS experiments with re-coupling of anisotropic interactions, like the 13C-(1)H dipolar couplings, benefit from the excellent resolution of 13C shifts that enables assignment of the couplings to specific carbon atoms. The traditional 2H NMR experiments on deuterated lipids have higher sensitivity when conducted on oriented samples at higher magnetic field strength. A very large number of NMR parameters from lipid bilayers is now accessible, providing information about conformation and dynamics for every lipid segment. The NMR methods have the sensitivity and resolution to study lipid-protein interaction, lateral lipid organization, and the location of solvents and drugs in the lipid matrix.
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Energy Technology Data Exchange (ETDEWEB)
Guo, Xuejun, E-mail: guoxj21@yahoo.com.cn; Du, Wei; Wang, Xuan; Yang, Zhifeng, E-mail: zfyang@bnu.edu.cn
2013-02-15
As the largest plateau-type wetland in the world and the largest peat storage in China, Zoige wetland faces severe water decline, and consequently accelerated peat degradation and carbon emission. Here, a variety of characterization approaches, including elemental analysis, UV–vis spectra, FT-IR spectra, and solid state {sup 13}C NMR spectra were used to investigate the degradation and the structural shift of humic acids (HAs) in correspondence with serious water loss in Zoige peatland. Water loss derived from both natural slope and artificial drainage caused a substantial degradation of organic matter and HAs. Compared with the blocks immersed by free surface water, HAs extracted from the drier blocks had more pronounced signals of carboxyl and carbonyl groups, but carried lower content of methoxyl, carbohydrate, alcohol and ether groups. The total aliphatic carbon in HAs from natural-slope drier site decreased almost one half, but in the artificial-drained site, only slightly decreased. Correspondingly, the HA aromaticity substantially increased in the site undergoing the longer time of aerobic oxidation, whereas varied little in the site impacted by extensive water leaching. - Highlights: ► HAs were decomposed significantly due to water loss in Zoige peatland. ► Water loss induced a significant shift in FT-IR and {sup 13}C NMR spectra of HAs. ► The ratio of aliphatic to O-aliphatic carbon (A/O-A ratio) dramatically increased. ► The aromaticity of HAs increased with water loss in the higher-altitude site.
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International Nuclear Information System (INIS)
Guo, Xuejun; Du, Wei; Wang, Xuan; Yang, Zhifeng
2013-01-01
As the largest plateau-type wetland in the world and the largest peat storage in China, Zoige wetland faces severe water decline, and consequently accelerated peat degradation and carbon emission. Here, a variety of characterization approaches, including elemental analysis, UV–vis spectra, FT-IR spectra, and solid state 13 C NMR spectra were used to investigate the degradation and the structural shift of humic acids (HAs) in correspondence with serious water loss in Zoige peatland. Water loss derived from both natural slope and artificial drainage caused a substantial degradation of organic matter and HAs. Compared with the blocks immersed by free surface water, HAs extracted from the drier blocks had more pronounced signals of carboxyl and carbonyl groups, but carried lower content of methoxyl, carbohydrate, alcohol and ether groups. The total aliphatic carbon in HAs from natural-slope drier site decreased almost one half, but in the artificial-drained site, only slightly decreased. Correspondingly, the HA aromaticity substantially increased in the site undergoing the longer time of aerobic oxidation, whereas varied little in the site impacted by extensive water leaching. - Highlights: ► HAs were decomposed significantly due to water loss in Zoige peatland. ► Water loss induced a significant shift in FT-IR and 13 C NMR spectra of HAs. ► The ratio of aliphatic to O-aliphatic carbon (A/O-A ratio) dramatically increased. ► The aromaticity of HAs increased with water loss in the higher-altitude site
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Energy Technology Data Exchange (ETDEWEB)
Boonsri, Pornthip [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States); Department of Chemistry, NANOTEC Center of Nanotechnology, National Nanotechnology Center, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Neumann, Terrence S.; Olson, Andrew L.; Cai, Sheng [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States); Herdendorf, Timothy J.; Miziorko, Henry M. [Division of Molecular Biology and Biochemistry, School of Biological Sciences, University of Missouri-Kansas City, Kansas City, MO 64110 (United States); Hannongbua, Supa [Department of Chemistry, NANOTEC Center of Nanotechnology, National Nanotechnology Center, Faculty of Science, Kasetsart University, Bangkok 10900 (Thailand); Sem, Daniel S., E-mail: daniel.sem@cuw.edu [Chemical Proteomics Facility at Marquette, Department of Chemistry, Marquette University, Milwaukee, WI 53201 (United States)
2013-01-04
Highlights: Black-Right-Pointing-Pointer Natural and synthetic inhibitors of human phosphomevalonate kinase identified. Black-Right-Pointing-Pointer Virtual screening yielded a hit rate of 15%, with inhibitor K{sub d}'s of 10-60 {mu}M. Black-Right-Pointing-Pointer NMR studies indicate significant protein conformational changes upon binding. -- Abstract: Phosphomevalonate kinase (PMK) phosphorylates mevalonate-5-phosphate (M5P) in the mevalonate pathway, which is the sole source of isoprenoids and steroids in humans. We have identified new PMK inhibitors with virtual screening, using autodock. Promising hits were verified and their affinity measured using NMR-based {sup 1}H-{sup 15}N heteronuclear single quantum coherence (HSQC) chemical shift perturbation and fluorescence titrations. Chemical shift changes were monitored, plotted, and fitted to obtain dissociation constants (K{sub d}). Tight binding compounds with K{sub d}'s ranging from 6-60 {mu}M were identified. These compounds tended to have significant polarity and negative charge, similar to the natural substrates (M5P and ATP). HSQC cross peak changes suggest that binding induces a global conformational change, such as domain closure. Compounds identified in this study serve as chemical genetic probes of human PMK, to explore pharmacology of the mevalonate pathway, as well as starting points for further drug development.
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Optimization and automation of quantitative NMR data extraction.
Bernstein, Michael A; Sýkora, Stan; Peng, Chen; Barba, Agustín; Cobas, Carlos
2013-06-18
NMR is routinely used to quantitate chemical species. The necessary experimental procedures to acquire quantitative data are well-known, but relatively little attention has been applied to data processing and analysis. We describe here a robust expert system that can be used to automatically choose the best signals in a sample for overall concentration determination and determine analyte concentration using all accepted methods. The algorithm is based on the complete deconvolution of the spectrum which makes it tolerant of cases where signals are very close to one another and includes robust methods for the automatic classification of NMR resonances and molecule-to-spectrum multiplets assignments. With the functionality in place and optimized, it is then a relatively simple matter to apply the same workflow to data in a fully automatic way. The procedure is desirable for both its inherent performance and applicability to NMR data acquired for very large sample sets.
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Drivers and moderators of business decline
Directory of Open Access Journals (Sweden)
Marius Pretorius
2010-12-01
Full Text Available Purpose: Reports of business failure elicit various reactions, while research in this domain often appears to be limited by a lack of access to information about failure and by the negativity that surrounds it. Those who have experienced failure do not readily talk about it, or they disappear from the radar screen of researchers. Yet failure is preceded by decline which, when focused on strategically, can reduce eventual failures if early action is taken. The main purpose of this study is to develop a conceptual framework or typology of the drivers and moderators of business decline. Design/methodology/approach: After applying the "grounded theory" approach to the academic literature on decline and failure, a conceptual framework for the variables that drive and moderate business decline is proposed. Findings: The study proposes that decline has three core drivers, three peripheral drivers and four moderators. The core drivers identified are: resource munificence; leadership as origin; and causality (strategic versus operational origin of decline. The three peripheral drivers are: unique preconditions; continuous decisions impact; and extremes dichotomy. The study describes four moderators of the drivers: life cycle stage; stakeholder perspective; quantitative versus qualitative nature of signs and causes; and finally the age and size effects. Research limitations/implications: The proposed conceptual framework is based on literature only, although it has found support during discussions with practitioners. It is proposed to readers of this journal for scrutiny and validation. Practical implications: Strategists need to understand what drives decline in order to act timeously; practitioners who have an insight into the moderators with their impacts could make better decisions in response to decline in organisations and possibly avoid business failure. Originality/Value: Understanding business decline is still a huge theoretical challenge, which