| 1. |
- Lin, Zijie, et al.
(författare)
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Evaluation and review of ways to differentiate sources of ethanol in postmortem blood
- 2020
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Ingår i: International journal of legal medicine. - : SPRINGER. - 0937-9827 .- 1437-1596. ; 134, s. 2081-2093
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Forskningsöversikt (refereegranskat)abstract
- Accurate determination of a persons blood alcohol concentration (BAC) is an important task in forensic toxicology laboratories because of the existence of statutory limits for driving a motor vehicle and workplace alcohol testing regulations. However, making a correct interpretation of the BAC determined in postmortem (PM) specimens is complicated, owing to the possibility that ethanol was produced in the body after death by the action of various micro-organisms (e.g., Candida species) and fermentation processes. This article reviews various ways to establish the source of ethanol in PM blood, including collection and analysis of alternative specimens (e.g., bile, vitreous humor (VH), and bladder urine), the identification of non-oxidative metabolites of ethanol, ethyl glucuronide (EtG) and ethyl sulfate (EtS), the urinary metabolites of serotonin (5-HTOL/5-HIAA), and identification ofn-propanol andn-butanol in blood, which are known putrefaction products. Practical utility of the various biomarkers including specificity and stability is discussed.
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| 2. |
- Zhao, Wei, et al.
(författare)
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Weak Crossability Barrier but Strong Juvenile Selection Supports Ecological Speciation of the Hybrid Pine Pinus Densata on the Tibetan Plateau
- 2014
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Ingår i: Evolution. - : John Wiley & Sons. - 0014-3820 .- 1558-5646. ; 68:11, s. 3120-3133
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Tidskriftsartikel (refereegranskat)abstract
- Determining how a new hybrid lineage can achieve reproductive isolation is a key to understanding the process and mechanisms of homoploid hybrid speciation. Here, we evaluated the degree and nature of reproductive isolation between the ecologically successful hybrid species Pinus densata and its parental species P. tabuliformis and P. yunnanensis. We performed interspecific crosses among the three species to assess their crossability. We then conducted reciprocal transplantation experiments to evaluate their fitness differentiation, and to examine how natural populations representing different directions of introgression differ in adaptation. The crossing experiments revealed weak genetic barriers among the species. The transplantation trials showed manifest evidence of local adaptation as the three species all performed best in their native habitats. Pinus densata populations from the western edge of its distribution have evolved a strong local adaptation to the specific habitat in that range; populations representing different directions of introgressants with the two parental species all showed fitness disadvantages in this P. densata habitat. These observations illustrate that premating isolation through selection against immigrants from other habitat types or postzygotic isolation through selection against backcrosses between the three species is strong. Thus, ecological selection in combination with endogenous components and geographic isolation has likely played a significant role in the speciation of P. densata.
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| 3. |
- Alseekh, Saleh, et al.
(författare)
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Mass spectrometry-based metabolomics: a guide for annotation, quantification and best reporting practices
- 2021
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Ingår i: Nature Methods. - : Springer Science and Business Media LLC. - 1548-7091 .- 1548-7105. ; 18:7, s. 747-756
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Forskningsöversikt (refereegranskat)abstract
- This Perspective, from a large group of metabolomics experts, provides best practices and simplified reporting guidelines for practitioners of liquid chromatography- and gas chromatography-mass spectrometry-based metabolomics. Mass spectrometry-based metabolomics approaches can enable detection and quantification of many thousands of metabolite features simultaneously. However, compound identification and reliable quantification are greatly complicated owing to the chemical complexity and dynamic range of the metabolome. Simultaneous quantification of many metabolites within complex mixtures can additionally be complicated by ion suppression, fragmentation and the presence of isomers. Here we present guidelines covering sample preparation, replication and randomization, quantification, recovery and recombination, ion suppression and peak misidentification, as a means to enable high-quality reporting of liquid chromatography- and gas chromatography-mass spectrometry-based metabolomics-derived data.
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| 4. |
- Attié, David, et al.
(författare)
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A time projection chamber with GEM-based readout
- 2017
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Ingår i: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. - : Elsevier BV. - 0168-9002. ; 856, s. 109-118
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Tidskriftsartikel (refereegranskat)abstract
- For the International Large Detector concept at the planned International Linear Collider, the use of time projection chambers (TPC) with micro-pattern gas detector readout as the main tracking detector is investigated. In this paper, results from a prototype TPC, placed in a 1. T solenoidal field and read out with three independent Gas Electron Multiplier (GEM) based readout modules, are reported. The TPC was exposed to a 6. GeV electron beam at the DESY II synchrotron. The efficiency for reconstructing hits, the measurement of the drift velocity, the space point resolution and the control of field inhomogeneities are presented.
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| 5. |
- Gao, Tanguang, et al.
(författare)
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Accelerating permafrost collapse on the eastern Tibetan Plateau
- 2021
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 16:5
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Tidskriftsartikel (refereegranskat)abstract
- Permafrost collapse can rapidly change regional soil-thermal and hydrological conditions, potentially stimulating production of climate-warming gases. Here, we report on rate and extent of permafrost collapse on the extensive Tibetan Plateau, also known as the Asian Water Tower and the Third Pole. Combined data from in situ measurements, unmanned aerial vehicles (UAV), manned aerial photographs, and satellite images suggest that permafrost collapse was accelerating across the Eastern Tibetan Plateau. From 1969 to 2017, the area of collapsed permafrost has increased by approximately a factor of 40, with 70% of the collapsed area forming since 2004. These widespread perturbations to the Tibetan Plateau permafrost could trigger changes in local ecosystem state and amplify large-scale permafrost climate feedbacks.
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| 6. |
- Wu, Junfang, et al.
(författare)
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Gender differences in the bile acid profiles of APP/PS1 transgenic AD mice
- 2020
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Ingår i: Brain Research Bulletin. - : Elsevier. - 0361-9230 .- 1873-2747. ; 161, s. 116-126
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Tidskriftsartikel (refereegranskat)abstract
- Alzheimer’s disease (AD) is a neurodegenerative disease and presents in the accumulation of amyloid and neurofibrillary tangle. The association between modulations of gut symbiotic microbes with neurological disease via bidirectional gut-brain axis has been well documented. Bile acid (BA) pools in the enterohepatic circulation could be valuable for probing complex biochemical interactions between host and their symbiotic microbiota. Herein we investigated the levels of 28 BAs in several compartments in enterohepatic circulation (including jejunal, ileum, cecum, colon and feces, plasma and liver tissue) by employing an APP/PS1 induced transgenic AD mouse model. We found that BA profiles in AD mice were gender specific. We observed decreased levels of taurine-conjugated primary BAs (TUDCA, TCA, T-α-MCA and T-β-MCA) and increased levels of secondary BA (iso-DCA) in plasma and liver extracts for female AD transgenic mice. In contrast, increased levels of TDCA in liver extracts and decreased levels of T-β-MCA in jejunal content were noted in male AD mice. These observations suggested that perturbations of BA profiles in AD mice displayed clear gender variations. Our study highlighted the roles of gut microbiota on neurodegenerative disease, which could be gender specific.
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