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1.
Background
The Euglycemic Hyperinsulinemic Clamp (EHC) is the most widely used experimental procedure for the determination of insulin sensitivity, and in its usual form the patient is followed under insulinization for two hours. In the present study, sixteen subjects with BMI between 18.5 and 63.6 kg/m2 were studied by long-duration (five hours) EHC. 相似文献2.
3.
Background
Prior to this report, members of the inward rectifier family, or Kir, have been found only in eukaryotes. Like most K+ channels, the pore-forming part of the protein is formed by four identical, or closely related, subunits. Each subunit contains a transmembrane M1-P-M2 motif that is followed by a relatively large C-terminus region unique to Kir's. 相似文献4.
Ken S Frahm Ole K Andersen Lars Arendt-Nielsen Carsten D Mørch 《Biomedical engineering online》2010,9(1):69
Background
CO2 lasers have been used for several decades as an experimental non-touching pain stimulator. The laser energy is absorbed by the water content in the most superficial layers of the skin. The deeper located nociceptors are activated by passive conduction of heat from superficial to deeper skin layers. 相似文献5.
Marc Hulsman Anouk Mentink Eugene P van Someren Koen J Dechering Jan de Boer Marcel JT Reinders 《BMC bioinformatics》2010,11(1):156
Background
Oligonucleotide arrays have become one of the most widely used high-throughput tools in biology. Due to their sensitivity to experimental conditions, normalization is a crucial step when comparing measurements from these arrays. Normalization is, however, far from a solved problem. Frequently, we encounter datasets with significant technical effects that currently available methods are not able to correct. 相似文献6.
Background
Proteins HMG1 and HMG2 are two of the most abundant non histone proteins in the nucleus of mammalian cells, and contain a domain of homology with many proteins implicated in the control of development, such as the sex-determination factor Sry and the Sox family of proteins. In vitro studies of interactions of HMG1/2 with DNA have shown that these proteins can bind to many unusual DNA structures, in particular to four-way junctions, with binding affinities of 107 to 109 M-1. 相似文献7.
A. Cadiere B. Couturaud J. Boismard P. Le Cann A. Gérard A. Mas C. Faye L. Garrelly B. Roig 《Journal of applied microbiology》2013,115(1):290-297
Aims
Virus detection has often been difficult due to a low concentration in water. In this study, we developed a new procedure based on concentration of virus particles on an innovative support: poly‐l ‐lysine dendrigrafts (DGL), coupled with directed nucleic acid extraction and real‐time PCR quantification.Methods and Results
This method was evaluated using the bacteriophage MS2 as a model virus. This virus exhibited the size and structural properties of human pathogenic enteric viruses and has often been used to assess new supports of concentration. Moreover, this bacteriophage is also a faecal contamination indicator. In this study, many water filtration conditions were tested (volume of water, concentration, etc.), and more than 80% of bacteriophage were recovered after filtration on polymer, in most conditions. We demonstrated that the method was linear (slope = 0·99 ± 0·04 and Y intercept when x = ?0·02 ± 0·28), valid (as manipulators, tested concentrations, volumes of sample and batch of polymer did not have any influence on concentration) and sensitive (allowing to concentrate up to 16 600‐fold 1 l of sample and to detect and quantify down to 750 GC l?1 and 7500 GC l?1, respectively).Conclusions
To conclude, this support exhibits high interest to retain viruses and to allow to detect low concentration of virus in water.Significance and Impact of the Study
This study gives valuable advance in the methods of concentration and diagnosis of virus in water. 相似文献8.
Therese Lindvall Jenny Karlsson Rikard Holmdahl ?sa Andersson 《Arthritis research & therapy》2009,11(1):R10
Introduction
In a cross between two mouse strains, the susceptible B10.RIII (H-2r) and resistant RIIIS/J (H-2r) strains, a locus on mouse chromosome 5 (Eae39) was previously shown to control experimental autoimmune encephalomyelitis (EAE). Recently, quantitative trait loci (QTL), linked to disease in different experimental arthritis models, were mapped to this region. The aim of the present study was to investigate whether genes within Eae39, in addition to EAE, control development of collagen-induced arthritis (CIA). 相似文献9.
Thomas Wu Mohammad Arshad Imrit Zahra Movahedinia Jude Kong R. Iestyn Woolway Sapna Sharma 《Diversity & distributions》2023,29(2):300-315
Aim
Many freshwater fishes are migrating poleward to more thermally suitable habitats in response to warming climates. In this study, we aimed to identify which freshwater fishes are most sensitive to climatic changes and asked: (i) how fast are lakes warming? (ii) how fast are fishes moving? and (iii) are freshwater fishes tracking climate?Location
Ontario, Canada.Methods
We assembled a database containing time series data on climate and species occurrence data from 10,732 lakes between 1986 and 2017. We calculated the rate of lake warming and climate velocity for these lakes. Climate velocities were compared with biotic velocities, specifically the rate at which the northernmost extent of each species shifted north.Results
Lakes in Ontario warmed by 0.2°C decade−1 on average, at a climate velocity of 9.4 km decade−1 between 1986 and 2017. In response, some freshwater fishes have shifted their northern range boundaries with considerable interspecific variation ranging from species moving southwards at a rate of −58.9 km decade−1 to species ranges moving northwards at a rate of 83.6 km decade−1 over the same time period. More freshwater fish species are moving into northern lakes in Ontario than those being lost. Generally, predators are moving their range edges northwards, whereas prey fishes are being lost from northern lakes.Main Conclusions
The concurrent loss of cooler refugia, combined with antagonistic competitive and predatory interactions with the range expanding species, has resulted in many commercially important predators moving their range edges northwards, whereas prey species have contracted their northern range edge boundaries. Trophic partitioning of range shifts highlights a previously undocumented observation of the loss of freshwater fishes from lower trophic levels in response to climate-driven migrations. 相似文献10.
Background
Detecting candidate B-cell epitopes in a protein is a basic and fundamental step in many immunological applications. Due to the impracticality of experimental approaches to systematically scan the entire protein, a computational tool that predicts the most probable epitope regions is desirable. 相似文献11.
Ferry Cornelissen Adriana MC Mus Patrick S Asmawidjaja Jan Piet van Hamburg Joel Tocker Erik Lubberts 《Arthritis research & therapy》2009,11(6):R194
Introduction
Interleukin (IL)-23 is essential for the development of various experimental autoimmune models. However, the role of IL-23 in non-autoimmune experimental arthritis remains unclear. Here, we examined the role of IL-23 in the non-autoimmune antigen-induced arthritis (AIA) model. In addition, the regulatory potential of IL-23 in IL-17A and retinoic acid-related orphan receptor gamma t (RORγt) expression in CD4+ and TCRγδ+ T cells was evaluated systemically as well as at the site of inflammation. 相似文献12.
Mohamad Hamdi Marco A Sanchez Lauren C Beene Qianyong Liu Scott M Landfear Barry P Rosen Zijuan Liu 《BMC molecular biology》2009,10(1):104
Background
Arsenic is one of the most ubiquitous toxins and endangers the health of tens of millions of humans worldwide. It is a mainly a water-borne contaminant. Inorganic trivalent arsenic (AsIII) is one of the major species that exists environmentally. The transport of AsIII has been studied in microbes, plants and mammals. Members of the aquaglyceroporin family have been shown to actively conduct AsIII and its organic metabolite, monomethylarsenite (MAsIII). However, the transport of AsIII and MAsIII in in any fish species has not been characterized. 相似文献13.
Background
Angiotensin II (AII) effects on intestinal Na+ transport may be multifactorial. To determine if AII might have a direct effect on intestinal epithelial Na+ transport, we investigated its actions on Na+ transport in human intestinal epithelial Caco2BBE cells. 相似文献14.
Background
To cancel experimental variations, microarray data must be normalized prior to analysis. Where an appropriate model for statistical data distribution is available, a parametric method can normalize a group of data sets that have common distributions. Although such models have been proposed for microarray data, they have not always fit the distribution of real data and thus have been inappropriate for normalization. Consequently, microarray data in most cases have been normalized with non-parametric methods that adjust data in a pair-wise manner. However, data analysis and the integration of resultant knowledge among experiments have been difficult, since such normalization concepts lack a universal standard. 相似文献15.
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Background
Modeling of pharmacokinetic parameters and pharmacodynamic actions requires knowledge of the arterial blood concentration. In most cases, experimental measurements are only available for a peripheral vein (usually antecubital) whose concentration may differ significantly from both arterial and central vein concentration. 相似文献17.
Chromatographic characterisation of 11 phytocannabinoids: Quantitative and fit‐to‐purpose performance as a function of extra‐column variance
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Matthew Noestheden Gareth Friedlander Jason Anspach Scott Krepich K. C. Hyland Wesley F. Zandberg 《Phytochemical analysis : PCA》2018,29(5):507-515
Introduction
Cannabis sativa L. (cannabis) is utilised as a therapeutic and recreational drug. With the legalisation of cannabis in many countries and the anticipated regulation of potency that will accompany legalisation, analytical testing facilities will require a broadly applicable, quantitative, high throughput method to meet increased demand. Current analytical methods for the biologically active components of cannabis (phytocannabinoids) suffer from low throughput and/or an incomplete complement of relevant phytocannabinoids.Objective
To develop a rapid, quantitative and broadly applicable liquid chromatography–tandem mass spectrometry analytical method for 11 phytocannabinoids in cannabis with acidic and neutral character.Methodology
Bulk diffusion coefficients were calculated using the Taylor–Aris open tubular method, with four reference compounds used to validate the experimental set‐up. Three columns were quantitatively evaluated using van Deemter plots and fit‐to‐purpose performance metrics. Low (1.2 μL2) and standard (3.6 μL2) extra‐column variance ultra‐high pressure liquid chromatography (UPLC) configurations were contrasted. Method performance was demonstrated with methanolic cannabis flower extracts.Results
Bulk diffusion coefficients and van Deemter plots for 11 phytocannabinoids are reported. The developed chromatographic method includes the challenging Δ8/Δ9‐tetrahydrocannabinol isobars and, at 6.5 min, is faster than existing methods targeting similar panels of biologically active phytocannabinoids.Conclusions
The bulk diffusion coefficients and van Deemter curves informed the development of a rapid quantitative method and will facilitate potential expansion to include additional compounds, including synthetic cannabinoids. The developed method can be implemented with low or standard extra‐column variance UPLC configurations. 相似文献18.
Background
Labeling whole Arabidopsis (Arabidopsis thaliana) plants to high enrichment with 13C for proteomics and metabolomics applications would facilitate experimental approaches not possible by conventional methods. Such a system would use the plant's native capacity for carbon fixation to ubiquitously incorporate 13C from 13CO2 gas. Because of the high cost of 13CO2 it is critical that the design conserve the labeled gas. 相似文献19.
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. 相似文献20.