| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
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| 5. |
- Kanoni, Stavroula, et al.
(författare)
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Implicating genes, pleiotropy, and sexual dimorphism at blood lipid loci through multi-ancestry meta-analysis.
- 2022
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Ingår i: Genome biology. - : Springer Science and Business Media LLC. - 1474-760X .- 1465-6906 .- 1474-7596. ; 23:1
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Tidskriftsartikel (refereegranskat)abstract
- Genetic variants within nearly 1000 loci are known to contribute to modulation of blood lipid levels. However, the biological pathways underlying these associations are frequently unknown, limiting understanding of these findings and hindering downstream translational efforts such as drug target discovery.To expand our understanding of the underlying biological pathways and mechanisms controlling blood lipid levels, we leverage a large multi-ancestry meta-analysis (N=1,654,960) of blood lipids to prioritize putative causal genes for 2286 lipid associations using six gene prediction approaches. Using phenome-wide association (PheWAS) scans, we identify relationships of genetically predicted lipid levels to other diseases and conditions. We confirm known pleiotropic associations with cardiovascular phenotypes and determine novel associations, notably with cholelithiasis risk. We perform sex-stratified GWAS meta-analysis of lipid levels and show that 3-5% of autosomal lipid-associated loci demonstrate sex-biased effects. Finally, we report 21 novel lipid loci identified on the X chromosome. Many of the sex-biased autosomal and X chromosome lipid loci show pleiotropic associations with sex hormones, emphasizing the role of hormone regulation in lipid metabolism.Taken together, our findings provide insights into the biological mechanisms through which associated variants lead to altered lipid levels and potentially cardiovascular disease risk.
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| 6. |
- Sampson, Joshua N., et al.
(författare)
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Analysis of Heritability and Shared Heritability Based on Genome-Wide Association Studies for 13 Cancer Types
- 2015
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Ingår i: Journal of the National Cancer Institute. - : Oxford University Press (OUP). - 0027-8874 .- 1460-2105. ; 107:12
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Tidskriftsartikel (refereegranskat)abstract
- Background: Studies of related individuals have consistently demonstrated notable familial aggregation of cancer. We aim to estimate the heritability and genetic correlation attributable to the additive effects of common single-nucleotide polymorphisms (SNPs) for cancer at 13 anatomical sites. Methods: Between 2007 and 2014, the US National Cancer Institute has generated data from genome-wide association studies (GWAS) for 49 492 cancer case patients and 34 131 control patients. We apply novel mixed model methodology (GCTA) to this GWAS data to estimate the heritability of individual cancers, as well as the proportion of heritability attributable to cigarette smoking in smoking-related cancers, and the genetic correlation between pairs of cancers. Results: GWAS heritability was statistically significant at nearly all sites, with the estimates of array-based heritability, h(l)(2), on the liability threshold (LT) scale ranging from 0.05 to 0.38. Estimating the combined heritability of multiple smoking characteristics, we calculate that at least 24% (95% confidence interval [CI] = 14% to 37%) and 7% (95% CI = 4% to 11%) of the heritability for lung and bladder cancer, respectively, can be attributed to genetic determinants of smoking. Most pairs of cancers studied did not show evidence of strong genetic correlation. We found only four pairs of cancers with marginally statistically significant correlations, specifically kidney and testes (rho = 0.73, SE = 0.28), diffuse large B-cell lymphoma (DLBCL) and pediatric osteosarcoma (rho = 0.53, SE = 0.21), DLBCL and chronic lymphocytic leukemia (CLL) (rho = 0.51, SE = 0.18), and bladder and lung (rho = 0.35, SE = 0.14). Correlation analysis also indicates that the genetic architecture of lung cancer differs between a smoking population of European ancestry and a nonsmoking Asian population, allowing for the possibility that the genetic etiology for the same disease can vary by population and environmental exposures. Conclusion: Our results provide important insights into the genetic architecture of cancers and suggest new avenues for investigation.
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| 7. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 8. |
- Jin, Ying-Hui, et al.
(författare)
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Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19 : An evidence-based clinical practice guideline (updated version)
- 2020
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Ingår i: Military Medical Research. - : Springer Science and Business Media LLC. - 2054-9369. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of a rapidly spreading illness, coronavirus disease 2019 (COVID-19), affecting more than seventeen million people around the world. Diagnosis and treatment guidelines for clinicians caring for patients are needed. In the early stage, we have issued "A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus (2019-nCoV) infected pneumonia (standard version)"; now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline. We formed a working group of clinical experts and methodologists. The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas: chemoprophylaxis, diagnosis, treatments, and discharge management. We searched the literature for direct evidence on the management of COVID-19, and assessed its certainty generated recommendations using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach. Recommendations were either strong or weak, or in the form of ungraded consensus-based statement. Finally, we issued 34 statements. Among them, 6 were strong recommendations for, 14 were weak recommendations for, 3 were weak recommendations against and 11 were ungraded consensus-based statement. They covered topics of chemoprophylaxis (including agents and Traditional Chinese Medicine (TCM) agents), diagnosis (including clinical manifestations, reverse transcription-polymerase chain reaction (RT-PCR), respiratory tract specimens, IgM and IgG antibody tests, chest computed tomography, chest x-ray, and CT features of asymptomatic infections), treatments (including lopinavir-ritonavir, umifenovir, favipiravir, interferon, remdesivir, combination of antiviral drugs, hydroxychloroquine/chloroquine, interleukin-6 inhibitors, interleukin-1 inhibitors, glucocorticoid, qingfei paidu decoction, lianhua qingwen granules/capsules, convalescent plasma, lung transplantation, invasive or noninvasive ventilation, and extracorporeal membrane oxygenation (ECMO)), and discharge management (including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge). We also created two figures of these recommendations for the implementation purpose. We hope these recommendations can help support healthcare workers caring for COVID-19 patients.
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| 9. |
- Wang, Mei jun, et al.
(författare)
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SIRT1-dependent deacetylation of Txnip H3K9ac is critical for exenatide-improved diabetic kidney disease
- 2023
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Ingår i: Biomedicine and Pharmacotherapy. - 0753-3322. ; 167
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Tidskriftsartikel (refereegranskat)abstract
- Glucagon-like peptide 1 receptor agonist exenatide (exendin-4) has potential protective capabilities against diabetic kidney disease (DKD). However, the underlying mechanism has not been fully elucidated. The expression of thioredoxin-interacting protein (Txnip) is upregulated during DKD progression by histone acetylation. Sirtuin 1 (SIRT1) is a deacetylase and is decreased in DKD, which indicates that it may regulate Txnip in this disease. Here, we used whole-body heterozygous Sirt1 knockout (Sirt1+/-) and kidney-specific Sirt1 knockout (KSK) mice to investigate whether SIRT1 regulates Txnip via histone deacetylation in DKD and exenatide-alleviated DKD. Exenatide substantially improved renal pathological damage, decreased the albumin-to-creatinine ratio (ACR), upregulated SIRT1 expression, and downregulated Txnip expression in kidneys of high-fat diet-treated C57BL/6J mice. However, these effects diminished in Sirt1+/- and KSK mice under exenatide treatment. The downregulation of Txnip expression by exendin-4 in high-glucose-treated SV40 MES13 cells was hampered during Sirt1 knockdown. These results demonstrate that kidney SIRT1 is indispensable in exenatide-improved DKD and downregulation of Txnip expression. Exendin-4 mechanistically downregulated Txnip histone 3 lysine 9 acetylation (H3K9ac) in a SIRT1-dependent manner and decreased spliced X-box binding protein 1 (XBP1s) recruitment to the Txnip promoter. These findings provide epigenetic evidence elucidating the specific mechanism for exenatide-mediated DKD alleviation and highlight the importance of Txnip as a promising therapeutic target for DKD.
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| 10. |
- Wen, Wanqing, et al.
(författare)
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Genome-wide association studies in East Asians identify new loci for waist-hip ratio and waist circumference
- 2016
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 6
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Tidskriftsartikel (refereegranskat)abstract
- Sixty genetic loci associated with abdominal obesity, measured by waist circumference (WC) and waist-hip ratio (WHR), have been previously identified, primarily from studies conducted in Europeanancestry populations. We conducted a meta-analysis of associations of abdominal obesity with approximately 2.5 million single nucleotide polymorphisms (SNPs) among 53,052 (for WC) and 48,312 (for WHR) individuals of Asian descent, and replicated 33 selected SNPs among 3,762 to 17,110 additional individuals. We identified four novel loci near the EFEMP1, ADAMTSL3, CNPY2, and GNAS genes that were associated with WC after adjustment for body mass index (BMI); two loci near the NID2 and HLA-DRB5 genes associated with WHR after adjustment for BMI, and three loci near the CEP120, TSC22D2, and SLC22A2 genes associated with WC without adjustment for BMI. Functional enrichment analyses revealed enrichment of corticotropin-releasing hormone signaling, GNRH signaling, and/or CDK5 signaling pathways for those newly-identified loci. Our study provides additional insight on genetic contribution to abdominal obesity.
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| 11. |
- Zou, Yatao, et al.
(författare)
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Manipulating crystallization dynamics through chelating molecules for bright perovskite emitters
- 2021
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Molecular additives are widely utilized to minimize non-radiative recombination in metal halide perovskite emitters due to their passivation effects from chemical bonds with ionic defects. However, a general and puzzling observation that can hardly be rationalized by passivation alone is that most of the molecular additives enabling high-efficiency perovskite light-emitting diodes (PeLEDs) are chelating (multidentate) molecules, while their respective monodentate counterparts receive limited attention. Here, we reveal the largely ignored yet critical role of the chelate effect on governing crystallization dynamics of perovskite emitters and mitigating trap-mediated non-radiative losses. Specifically, we discover that the chelate effect enhances lead-additive coordination affinity, enabling the formation of thermodynamically stable intermediate phases and inhibiting halide coordination-driven perovskite nucleation. The retarded perovskite nucleation and crystal growth are key to high crystal quality and thus efficient electroluminescence. Our work elucidates the full effects of molecular additives on PeLEDs by uncovering the chelate effect as an important feature within perovskite crystallization. As such, we open new prospects for the rationalized screening of highly effective molecular additives.
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| 12. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 13. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 14. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 15. |
- An, Junghwa, et al.
(författare)
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Permanent Genetic Resources added to Molecular Ecology Resources Database 1 October 2009-30 November 2009
- 2010
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Ingår i: Molecular Ecology Resources. - : Wiley. - 1755-098X .- 1755-0998. ; 10:2, s. 404-408
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Tidskriftsartikel (refereegranskat)abstract
- This article documents the addition of 411 microsatellite marker loci and 15 pairs of Single Nucleotide Polymorphism (SNP) sequencing primers to the Molecular Ecology Resources Database. Loci were developed for the following species: Acanthopagrus schlegeli, Anopheles lesteri, Aspergillus clavatus, Aspergillus flavus, Aspergillus fumigatus, Aspergillus oryzae, Aspergillus terreus, Branchiostoma japonicum, Branchiostoma belcheri, Colias behrii, Coryphopterus personatus, Cynogolssus semilaevis, Cynoglossus semilaevis, Dendrobium officinale, Dendrobium officinale, Dysoxylum malabaricum, Metrioptera roeselii, Myrmeciza exsul, Ochotona thibetana, Neosartorya fischeri, Nothofagus pumilio, Onychodactylus fischeri, Phoenicopterus roseus, Salvia officinalis L., Scylla paramamosain, Silene latifo, Sula sula, and Vulpes vulpes. These loci were cross-tested on the following species: Aspergillus giganteus, Colias pelidne, Colias interior, Colias meadii, Colias eurytheme, Coryphopterus lipernes, Coryphopterus glaucofrenum, Coryphopterus eidolon, Gnatholepis thompsoni, Elacatinus evelynae, Dendrobium loddigesii Dendrobium devonianum, Dysoxylum binectariferum, Nothofagus antarctica, Nothofagus dombeyii, Nothofagus nervosa, Nothofagus obliqua, Sula nebouxii, and Sula variegata. This article also documents the addition of 39 sequencing primer pairs and 15 allele specific primers or probes for Paralithodes camtschaticus.
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| 16. |
- Atsawawaranunt, Kamolphat, et al.
(författare)
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The SISAL database : a global resource to document oxygen and carbon isotope records from speleothems
- 2018
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Ingår i: Earth System Science Data. - : Copernicus GmbH. - 1866-3508 .- 1866-3516. ; 10:3, s. 1687-1713
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Tidskriftsartikel (refereegranskat)abstract
- Stable isotope records from speleothems provide information on past climate changes, most particularly information that can be used to reconstruct past changes in precipitation and atmospheric circulation. These records are increasingly being used to provide "out-of-sample" evaluations of isotope-enabled climate models. SISAL (Speleothem Isotope Synthesis and Analysis) is an international working group of the Past Global Changes (PAGES) project. The working group aims to provide a comprehensive compilation of speleothem isotope records for climate reconstruction and model evaluation. The SISAL database contains data for individual speleothems, grouped by cave system. Stable isotopes of oxygen and carbon (delta O-18, delta C-13) measurements are referenced by distance from the top or bottom of the speleothem. Additional tables provide information on dating, including information on the dates used to construct the original age model and sufficient information to assess the quality of each data set and to erect a standardized chronology across different speleothems. The metadata table provides location information, information on the full range of measurements carried out on each speleothem and information on the cave system that is relevant to the interpretation of the records, as well as citations for both publications and archived data.
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| 17. |
- Cai, Fuhong, et al.
(författare)
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Multifunctional optical imaging using dye-coated gold nanorods in a turbid medium
- 2011
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Ingår i: Journal of Biomedical Optics. - : SPIE-Intl Soc Optical Eng. - 1083-3668 .- 1560-2281. ; 16:1, s. 016002-
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Tidskriftsartikel (refereegranskat)abstract
- We report multifunctional optical imaging using dye-coated gold nanorods. Three types of useful information, namely, Raman, fluorescence signals, and absorption contrast, can be obtained from a phantom experiment. These three kinds of information are detected in a nanoparticle-doped-phantom using diffuse optical imaging. Our novel nanoparticle could be used as a multimodality marker for future bioimaging applications.
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| 18. |
- Cai, Fuhong, et al.
(författare)
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Use of tunable second-harmonic signal from KNbO3 nanoneedles to find optimal wavelength for deep-tissue imaging
- 2014
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Ingår i: Laser & Photonics reviews. - : Wiley. - 1863-8880 .- 1863-8899. ; 8:6, s. 865-874
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear optical (NLO) responses of perovskite-type nanostructures have a variety of potential applications owing to the highly efficient frequency conversion guaranteed by both the material itself and the nanometer-scale configuration. KNbO3 (KN) nanoneedles have been identified as a promising NLO material because of the superior broadband frequency conversion efficiency, and if incident light is propagating in a direction perpendicular to the axis of a nanoneedle, then the phase-matching constraint can be relaxed. Here, the second-harmonic generation (SHG) and third-harmonic generation (THG) responses of both individual and clustered KN nanoneedles are reported. Based on these results, a novel method is proposed for determining the optimal excitation wavelength for NLO imaging of several biological samples, with KN nanoneedles acting as NLO agents. The method is shown to provide the optical features in the focal plane and a more reliable estimation of the optimal excitation wavelength for deep-tissue imaging.
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| 19. |
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| 20. |
- Cai, Guang-Jun, 1956
(författare)
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Microstructure and Mechanical Properties of High Chromium Steel Weld Metals
- 1994
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The microstructure of three types of Cr steel weld metals, containing 5%, 9% and 12% chromium, was studied in different heat treated conditions using optical microscopy, analytical transmission electron microscopy and atom probe field-ion microscopy. The mechanical properties of the weld metals were investigated. Scanning electron microscopy (SEM) and optical microscopy were used to carry out the fractography investigation of the impacted specimens. In the 5% Cr steel weld metal, it was found that M7C3 and M2C started to precipitate during tempering at 500 °C. M23C6 precipitated out from 600 °C. The composition of the precipitates also changed according to the tempering temperature. The development of microstructure during tempering was discussed. The microstructure of three 9% Cr steel weld metals consisted of lath martensite, some retained .delta.-ferrite and precipitates. The predominant precipitates were M23C6. In weld metals containing V and Nb, MC and M2C were present. The failure mode of the impacted weld metals was quasi-cleavage. Non- metallic inclusions were found to be the nucleation sites for cleavage cracks during impact. The cleavage stress of the weld metals was determined by the size of the inclusions and the size of martensite packets or recrystallized ferrite grains (in the case that the quantity of recrystallized ferrite was high). The impact toughness of the weld metals depended on the yield stress and fracture stress of the materials. The microstructure of three varieties of 12% Cr steel weld metals consisted also of martensite, retained .delta.-ferrite and precipitates. The precipitates included M23C6, MX and M2X. The morphology, quantity and distribution of the precipitates were determined by composition and heat treatment of the weld metals. The microstructure development in the weld metals in different heat treatment conditions was investigated. The failure mode of impacted specimens was mainly cleavage. Intercooling the weld metals to 125 °C before post-weld heat treatment did not affect the tensile strength of the weld metals very much, but improved their impact toughness dramatically. The mechanism by which the microstructure of the weld metals affects their mechanical properties was discussed.
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| 21. |
- Cai, Jing, et al.
(författare)
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Influence of organic aerosol molecular composition on particle absorptive properties in autumn Beijing
- 2022
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Ingår i: Atmospheric Chemistry And Physics. - : Copernicus GmbH. - 1680-7316 .- 1680-7324. ; 22:2, s. 1251-1269
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Tidskriftsartikel (refereegranskat)abstract
- Organic aerosol (OA) is a major component of fine particulate matter (PM), affecting air quality, human health, and the climate. The absorptive and reflective behavior of OA components contributes to determining particle optical properties and thus their effects on the radiative budget of the troposphere. There is limited knowledge on the influence of the molecular composition of OA on particle optical properties in the polluted urban environment. In this study, we characterized the molecular composition of oxygenated OA collected on filter samples in the autumn of 2018 in Beijing, China, with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO–CIMS). Three haze episodes occurred during our sampling period with daily maximum concentrations of OA of 50, 30, and 55 µg m−3. We found that the signal intensities of dicarboxylic acids and sulfur-containing compounds increased during the two more intense haze episodes, while the relative contributions of wood-burning markers and other aromatic compounds were enhanced during the cleaner periods. We further assessed the optical properties of oxygenated OA components by combining detailed chemical composition measurements with collocated particle light absorption measurements. We show that light absorption enhancement (Eabs) of black carbon (BC) was mostly related to more oxygenated OA (e.g., dicarboxylic acids), likely formed in aqueous-phase reactions during the intense haze periods with higher relative humidity, and speculate that they might contribute to lensing effects. Aromatics and nitro-aromatics (e.g., nitrocatechol and its derivatives) were mostly related to a high light absorption coefficient (babs) consistent with light-absorbing (brown) carbon (BrC). Our results provide information on oxygenated OA components at the molecular level associated with BrC and BC particle light absorption and can serve as a basis for further studies on the effects of anthropogenic OA on radiative forcing in the urban environment.
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| 22. |
- Cai, Jing, et al.
(författare)
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Influence of organic aerosol molecular composition on particle absorptive properties in autumn Beijing
- 2022
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Ingår i: Atmospheric Chemistry and Physics. - 1680-7316 .- 1680-7324. ; 22, s. 1251-1269
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Tidskriftsartikel (refereegranskat)abstract
- Organic aerosol (OA) is a major component of fine particulate matter (PM), affecting air quality, human health, and the climate. The absorptive and reflective behavior of OA components contributes to determining particle optical properties and thus their effects on the radiative budget of the troposphere. There is limited knowledge on the influence of the molecular composition of OA on particle optical properties in the polluted urban environment. In this study, we characterized the molecular composition of oxygenated OA collected on filter samples in the autumn of 2018 in Beijing, China, with a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-CIMS). Three haze episodes occurred during our sampling period with daily maximum concentrations of OA of 50, 30, and 55 μg m-3. We found that the signal intensities of dicarboxylic acids and sulfur-containing compounds increased during the two more intense haze episodes, while the relative contributions of wood-burning markers and other aromatic compounds were enhanced during the cleaner periods. We further assessed the optical properties of oxygenated OA components by combining detailed chemical composition measurements with collocated particle light absorption measurements. We show that light absorption enhancement (Eabs) of black carbon (BC) was mostly related to more oxygenated OA (e.g., dicarboxylic acids), likely formed in aqueous-phase reactions during the intense haze periods with higher relative humidity, and speculate that they might contribute to lensing effects. Aromatics and nitro-aromatics (e.g., nitrocatechol and its derivatives) were mostly related to a high light absorption coefficient (babs) consistent with light-absorbing (brown) carbon (BrC). Our results provide information on oxygenated OA components at the molecular level associated with BrC and BC particle light absorption and can serve as a basis for further studies on the effects of anthropogenic OA on radiative forcing in the urban environment. Copyright:
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| 23. |
- Cai, Wei-Jun, et al.
(författare)
-
Carbon fluxes across boundaries in the Pacific sector of the Arctic Ocean in a changing environment
- 2014
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Ingår i: THE PACIFIC ARCTIC REGION: ECOSYSTEM STATUS AND TRENDS IN A RAPIDLY CHANGING ENVIRONMENT. - : Springer. - 9789401788625
-
Bokkapitel (refereegranskat)abstract
- In this chapter we examine carbon fluxes across the land-ocean and air-sea boundaries in the Pacific Arctic Region (PAR) as well as ocean gateway exchanges in the region. The latter ocean gateway fluxes includes dissolved inorganic carbon (DIC) transported into the area from the Pacific Ocean via Bering Strait and exported to the Atlantic Ocean via the Canadian Archipelago, as well as exchanges between various sub-regions within the system. We emphasize the changes in the magnitudes of these fluxes in the context of climate warming and sea-ice melt, as well as other hydrological cycle changes in the Arctic. We conclude that while the inflow of DIC from the Pacific Ocean is relatively well quantified (623 ± 78 Tg C yr-1; T=1012), the intermittent input flux from the East Siberian Sea (ESS) is not (32 ± 16 Tg C yr-1). Most of the uncertainty is associated with variability in actual water flux rather than DIC content of this water, and thus is viewed as a systematic error in our DIC mass balance analysis. Furthermore, we determined an export flux of 749 Tg C yr-1 to the Atlantic Ocean, with the caveat that this term has unknown uncertainty due to a paucity of DIC data from the Canadian Archipelago. Within the PAR, the Chukchi Sea is the dominant site for atmospheric carbon dioxide (CO2) uptake (up to 35-46 Tg C yr-1), while the Beaufort Sea (2.9 Tg C yr-1) and the Canadian Archipelago (~10 Tg C yr-1) take-up much less CO2 with latter potentially a weak source of CO2 to the atmosphere during certain times of the year. Additionally, the ESS shelf is a net source of CO2 for the atmosphere (< 5 Tg C yr-1). Summertime CO2 uptake capacity in the deep Canada Basin has increased greatly over the past few years as sea-ice retreat progresses rapidly though earlier flux estimates may be on the high end. Overall, the PAR appears to export more DIC to the Atlantic Ocean than it receives through the combined inputs from the Pacific Ocean, the ESS, the atmosphere, and the rivers by a small amount (45 Tg C yr-1 or 6%). Our preliminary DIC budget suggests that the PAR is probably weakly net heterotrophic (i.e., respiring more organic carbon, OC, than its production). This tentative assessment of the trophic status of the PAR, if supported by further data, suggests that in addition to labile OC produced in the highly productive marginal seas, some riverine and coastal erosion-derived OC is also recycled within this Arctic system. As warming progresses, the Arctic Ocean may produce and export more DIC to the Atlantic Ocean. Whether this change will turn the Arctic Ocean into a weaker CO2 sink or even a CO2 source for the atmosphere is uncertain and dependent on multiple factors that control the rate of surface water CO2 increase versus the rate of the atmospheric CO2 increase.
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| 24. |
- Chang, Lufen, et al.
(författare)
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The E3 ubiquitin ligase itch couples JNK activation to TNFα-induced cell death by inducing c-FLIP L turnover
- 2006
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Ingår i: Cell. - 0092-8674 .- 1097-4172. ; 124:3, s. 601-613
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Tidskriftsartikel (refereegranskat)abstract
- The proinflammatory cytokine tumor necrosis factor (TNF) α signals both cell survival and death. The biological outcome of TNFα treatment is determined by the balance between NF-κB and Jun kinase (JNK) signaling; NF-κB promotes survival, whereas JNK enhances cell death. Critically, identity of a JNK substrate that promotes TNFα-induced apoptosis has been outstanding. Here we show that TNFα-mediated JNK activation accelerates turnover of the NF-κB-induced antiapoptotic protein c-FLIP, an inhibitor of caspase-8. This is not due to direct c-FLIP phosphorylation but depends on JNK-mediated phosphorylation and activation of the E3 ubiquitin ligase Itch, which specifically ubiquitinates c-FLIP and induces its proteasomal degradation. JNK1 or Itch deficiency or treatment with a JNK inhibitor renders mice resistant in three distinct models of TNFα-induced acute liver failure, and cells from these mice do not display inducible c-FLIPL ubiquitination and degradation. Thus, JNK antagonizes NF-κB during TNFα signaling by promoting the proteasomal elimination of c-FLIPL.
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| 25. |
- Chen, Kai, et al.
(författare)
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Room-temperature multiferroic properties in NiBi2O4
- 2010
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Ingår i: Europhysics letters. - : European Physical Society. - 0295-5075 .- 1286-4854. ; 89:2
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Tidskriftsartikel (refereegranskat)abstract
- Magnetism and ferroelectricity at room temperature are observed in the NiBi2O4 ceramics. Both the time reversal and the inversion symmetry of the structure (space group F-43m) are broken. The saturation magnetization is 0.028 emu/g and the saturation polarization 2P(s) similar to 4.0 mu C/cm(2). NiBi2O4 also shows other room-temperature multiferroic properties, e. g. the piezoelectric coefficient (d(33)), the polarized dielectric character, the magneto-dielectric response and the magnetoelectric effect. Copyright (C) EPLA, 2010
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| 26. |
- Chen, Zhen, et al.
(författare)
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Multifunctional conductive hydrogels and their applications as smart wearable devices
- 2021
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Ingår i: Journal of materials chemistry. B. - : Royal Society of Chemistry (RSC). - 2050-750X .- 2050-7518. ; 9:11, s. 2561-2583
-
Forskningsöversikt (refereegranskat)abstract
- Recently, hydrogekbased conductive materials and their applications as smart wearable devices have been paid tremendous attention due to their high stretchability, flexibility, and excellent biocompatibility. Compared with single functional conductive hydrogels, multifunctional conductive hydrogels are more advantageous to match various demands for practical applications. This review focuses on multifunctional conductive hydrogels applied for smart wearable devices. Representative strategies for conduction of hydrogels are discussed firstly: (1) electronic conduction based on the conductive fillers and (2) ionic conduction based on charged ions. Then, the common and intensive research on multiple functionahties of conductive hydrogels, such as mechanical properties, conductive and sensory properties, anti-freezing and moisturizing properties, and adhesion and self-healing properties is presented. The applications of multifunctional conductive hydrogels such as in human motion sensors, sensory skins, and personal healthcare diagnosis are provided in the third part. Finally, we offer our perspective on open challenges and future areas of interest for multifunctional conductive hydrogels used as smart wearable devices.
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| 27. |
- Cheng, Fangwen, et al.
(författare)
-
Interfacial Property Tuning Enables Copper Electrodes in High-Performance n-i-p Perovskite Solar Cells
- 2023
-
Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 145:36, s. 20081-20087
-
Tidskriftsartikel (refereegranskat)abstract
- Developing cost-effective metal electrodes is essential for reducing the overall cost of perovskite solar cells (PSCs). Although copper is highly conductive and economical, it is rarely used as a positive electrode in efficient n-i-p PSCs due to its unmatched Fermi level and low oxidation threshold. We report herein that modification for the inner surface of electrodes using mercaptopyridine-based molecules readily tunes the electronic and chemical properties of copper, which has been achieved by fine-tuning the substituents of mercaptopyridines. The systematic adjustment for the Fermi level and oxidation potential of copper facilitates interfacial hole extraction and enhances the oxidation resistance of copper electrodes, which enables pure copper electrodes to be used in high-performance n-i-p PSCs with different hole transport materials. The resulting PSCs with copper electrodes display excellent power conversion efficiency and long-term stability, even comparable to those of the gold electrodes, showing great potential in the manufacturing and commercialization of PSCs.
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| 28. |
- Cheng, Hai, et al.
(författare)
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Milankovitch theory and monsoon
- 2022
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Ingår i: The Innovation. - : Elsevier BV. - 2666-6758. ; 3:6
-
Forskningsöversikt (refereegranskat)abstract
- The widely accepted “Milankovitch theory” explains insolation-induced waxing and waning of the ice sheets and their effect on the global climate on orbital timescales. In the past half century, however, the theory has often come under scrutiny, especially regarding its “100-ka problem.” Another drawback, but the one that has received less attention, is the “monsoon problem,” which pertains to the exclusion of monsoon dynamics in classic Milankovitch theory even though the monsoon prevails over the vast low-latitude (∼30° N to ∼30° S) region that covers half of the Earth's surface and receives the bulk of solar radiation. In this review, we discuss the major issues with the current form of Milankovitch theory and the progress made at the research forefront. We suggest shifting the emphasis from the ultimate outcomes of the ice volume to the causal relationship between changes in northern high-latitude insolation and ice age termination events (or ice sheet melting rate) to help reconcile the classic “100-ka problem.” We discuss the discrepancies associated with the characterization of monsoon dynamics, particularly the so-called “sea-land precession-phase paradox” and the “Chinese 100-ka problem.” We suggest that many of these discrepancies are superficial and can be resolved by applying a holistic “monsoon system science” approach. Finally, we propose blending the conventional Kutzbach orbital monsoon hypothesis, which calls for summer insolation forcing of monsoons, with Milankovitch theory to formulate a combined “Milankovitch-Kutzbach hypothesis” that can potentially explain the dual nature of orbital hydrodynamics of the ice sheet and monsoon systems, as well as their interplays and respective relationships with the northern high-latitude insolation and inter-tropical insolation differential.
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| 29. |
- Cho, Yoon Shin, et al.
(författare)
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Meta-analysis of genome-wide association studies identifies eight new loci for type 2 diabetes in east Asians.
- 2012
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 44:1
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Tidskriftsartikel (refereegranskat)abstract
- We conducted a three-stage genetic study to identify susceptibility loci for type 2 diabetes (T2D) in east Asian populations. We followed our stage 1 meta-analysis of eight T2D genome-wide association studies (6,952 cases with T2D and 11,865 controls) with a stage 2 in silico replication analysis (5,843 cases and 4,574 controls) and a stage 3 de novo replication analysis (12,284 cases and 13,172 controls). The combined analysis identified eight new T2D loci reaching genome-wide significance, which mapped in or near GLIS3, PEPD, FITM2-R3HDML-HNF4A, KCNK16, MAEA, GCC1-PAX4, PSMD6 and ZFAND3. GLIS3, which is involved in pancreatic beta cell development and insulin gene expression, is known for its association with fasting glucose levels. The evidence of an association with T2D for PEPD and HNF4A has been shown in previous studies. KCNK16 may regulate glucose-dependent insulin secretion in the pancreas. These findings, derived from an east Asian population, provide new perspectives on the etiology of T2D.
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| 30. |
- Comas-Bru, Laia, et al.
(författare)
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Evaluating model outputs using integrated global speleothem records of climate change since the last glacial
- 2019
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Ingår i: Climate of the Past. - : Copernicus GmbH. - 1814-9324 .- 1814-9332. ; 15:4, s. 1557-1579
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Tidskriftsartikel (refereegranskat)abstract
- Although quantitative isotope data from speleothems has been used to evaluate isotope-enabled model simulations, currently no consensus exists regarding the most appropriate methodology through which to achieve this. A number of modelling groups will be running isotope-enabled palaeoclimate simulations in the framework of the Coupled Model Intercomparison Project Phase 6, so it is timely to evaluate different approaches to using the speleothem data for data-model comparisons. Here, we illustrate this using 456 globally distributed speleothem delta O-18 records from an updated version of the Speleothem Isotopes Synthesis and Analysis (SISAL) database and palaeoclimate simulations generated using the ECHAM5-wiso isotope-enabled atmospheric circulation model. We show that the SISAL records reproduce the first-order spatial patterns of isotopic variability in the modern day, strongly supporting the application of this dataset for evaluating model-derived isotope variability into the past. However, the discontinuous nature of many speleothem records complicates the process of procuring large numbers of records if data-model comparisons are made using the traditional approach of comparing anomalies between a control period and a given palaeoclimate experiment. To circumvent this issue, we illustrate techniques through which the absolute isotope values during any time period could be used for model evaluation. Specifically, we show that speleothem isotope records allow an assessment of a model's ability to simulate spatial isotopic trends. Our analyses provide a protocol for using speleothem isotope data for model evaluation, including screening the observations to take into account the impact of speleothem mineralogy on delta O-18 values, the optimum period for the modern observational baseline and the selection of an appropriate time window for creating means of the isotope data for palaeo-time-slices.
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| 31. |
- Fiore, Achille, et al.
(författare)
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Detailed spectrophotometric analysis of the superluminous and fast evolving SN 2019neq
- 2024
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Ingår i: Monthly notices of the Royal Astronomical Society. - 0035-8711 .- 1365-2966. ; 527:3, s. 6473-6494
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Tidskriftsartikel (refereegranskat)abstract
- SN 2019neq was a very fast evolving superluminous supernova. At a redshift z = 0.1059, its peak absolute magnitude was −21.5 ± 0.2 mag in g band. In this work, we present data and analysis from an extensive spectrophotometric follow-up campaign using multiple observational facilities. Thanks to a nebular spectrum of SN 2019neq, we investigated some of the properties of the host galaxy at the location of SN 2019neq and found that its metallicity and specific star formation rate are in a good agreement with those usually measured for SLSNe-I hosts. We then discuss the plausibility of the magnetar and the circumstellar interaction scenarios to explain the observed light curves, and interpret a nebular spectrum of SN 2019neq using published SUMO radiative-transfer models. The results of our analysis suggest that the spin-down radiation of a millisecond magnetar with a magnetic field B ≃ 6×1014 G could boost the luminosity of SN 2019neq.
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| 32. |
- Hartman, Erik, et al.
(författare)
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Bioinformatic Analysis of the Wound Peptidome Reveals Potential Biomarkers and Antimicrobial Peptides
- 2021
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Ingår i: Frontiers in Immunology. - : Frontiers Media SA. - 1664-3224. ; 11
-
Tidskriftsartikel (refereegranskat)abstract
- Wound infection is a common and serious medical condition with an unmet need for improved diagnostic tools. A peptidomic approach, aided by mass spectrometry and bioinformatics, could provide novel means of identifying new peptide biomarkers for wound healing and infection assessment. Wound fluid is suitable for peptidomic analysis since it is both intimately tied to the wound environment and is readily available. In this study we investigate the peptidomes of wound fluids derived from surgical drainages following mastectomy and from wound dressings following facial skin grafting. By applying sorting algorithms and open source third party software to peptidomic label free tandem mass spectrometry data we provide an unbiased general methodology for analyzing and differentiating between peptidomes. We show that the wound fluid peptidomes of patients are highly individualized. However, differences emerge when grouping the patients depending on wound type. Furthermore, the abundance of peptides originating from documented antimicrobial regions of hemoglobin in infected wounds may contribute to an antimicrobial wound environment, as determined by in silico analysis. We validate our findings by compiling literature on peptide biomarkers and peptides of physiological significance and cross checking the results against our dataset, demonstrating that well-documented peptides of immunological significance are abundant in infected wounds, and originate from certain distinct regions in proteins such as hemoglobin and fibrinogen. Ultimately, we have demonstrated the power using sorting algorithms and open source software to help yield insights and visualize peptidomic data.
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| 33. |
- He, Liang, et al.
(författare)
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Discrete element simulation of porous asphalt mixture clogging law
- 2023
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Ingår i: Jiaotong Yunshu Gongcheng Xuebao/Journal of Traffic and Transportation Engineering. - : Chang'an University. - 1671-1637. ; 23:2, s. 78-91
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Tidskriftsartikel (refereegranskat)abstract
- To reveal the pore clogging law of porous asphalt mixture, the combination study of model experiment and simulation of porous asphalt mixture clogging was conducted. The pore characteristics of the porous asphalt mixture were analyzed based on the CT-scanning and discrete element software PFC3D V5. 0, and the pore data of the porous asphalt mixture were obtained. The aggregates of different particle sizes were put into PFC3D V5. 0, and the compacted virtual specimens were generated according to the pore characteristics. The accuracy of the model was verified by comparing the pore images of actual specimens with the MATLAB slices. In the self-weight condition, the simulation was set with the porous asphalt mixture specimen being intruded by clogging particles with specific gradation composition. The data of indoor experiments were compared and verified. The particle sizes of clogging particles were changed, and the pore decay rates of the specimen were analyzed. The clogging-sensitive particles were identified. In the self-weight condition, the fluid simulation experiment was introduced, and the change law of specimen clogging was analyzed by changing the seepage rate of fluid. Analysis results show that the virtual specimen generated by PFC3D V5. 0 has high accuracy, and the simulation reveals the clogging law of the specimen. The small particles not only accumulate at the throat position causing clogging, but also congregate and interlock with the particles of larger sizes resulting in clogging too. In the self-weight condition, the clogging is mainly concentrated at the upper 30 mm of the mixture specimen, and the size distribution of corresponding clogging-sensitive particles is 0. 150-0. 600 mm. The size distribution of clogging particles has a great impact on the clogging results. In the conditions of gravity and fluid, with the seepage rate increasing from 0. 005 m • s-1 to 0. 030 m • s-1, the changing rate of pore decay rate increases. In addition, the clogging particles remaining in the mixture decrease, accompanied by the reduction of the pore decay rate. Therefore, the local rainfall conditions should also be considered in the design and maintenance of drainage asphalt pavement. 2 tabs, 20 figs, 30 refs. © 2023 Chang'an University. All rights reserved.
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| 34. |
- Jarvis, Erich D., et al.
(författare)
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Phylogenomic analyses data of the avian phylogenomics project
- 2015
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Ingår i: GigaScience. - : Oxford University Press (OUP). - 2047-217X. ; 4
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Determining the evolutionary relationships among the major lineages of extant birds has been one of the biggest challenges in systematic biology. To address this challenge, we assembled or collected the genomes of 48 avian species spanning most orders of birds, including all Neognathae and two of the five Palaeognathae orders. We used these genomes to construct a genome-scale avian phylogenetic tree and perform comparative genomic analyses. Findings: Here we present the datasets associated with the phylogenomic analyses, which include sequence alignment files consisting of nucleotides, amino acids, indels, and transposable elements, as well as tree files containing gene trees and species trees. Inferring an accurate phylogeny required generating: 1) A well annotated data set across species based on genome synteny; 2) Alignments with unaligned or incorrectly overaligned sequences filtered out; and 3) Diverse data sets, including genes and their inferred trees, indels, and transposable elements. Our total evidence nucleotide tree (TENT) data set (consisting of exons, introns, and UCEs) gave what we consider our most reliable species tree when using the concatenation-based ExaML algorithm or when using statistical binning with the coalescence-based MP-EST algorithm (which we refer to as MP-EST*). Other data sets, such as the coding sequence of some exons, revealed other properties of genome evolution, namely convergence. Conclusions: The Avian Phylogenomics Project is the largest vertebrate phylogenomics project to date that we are aware of. The sequence, alignment, and tree data are expected to accelerate analyses in phylogenomics and other related areas.
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| 35. |
- Jarvis, Erich D., et al.
(författare)
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Whole-genome analyses resolve early branches in the tree of life of modern birds
- 2014
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 346:6215, s. 1320-1331
-
Tidskriftsartikel (refereegranskat)abstract
- To better determine the history of modern birds, we performed a genome-scale phylogenetic analysis of 48 species representing all orders of Neoaves using phylogenomic methods created to handle genome-scale data. We recovered a highly resolved tree that confirms previously controversial sister or close relationships. We identified the first divergence in Neoaves, two groups we named Passerea and Columbea, representing independent lineages of diverse and convergently evolved land and water bird species. Among Passerea, we infer the common ancestor of core landbirds to have been an apex predator and confirm independent gains of vocal learning. Among Columbea, we identify pigeons and flamingoes as belonging to sister clades. Even with whole genomes, some of the earliest branches in Neoaves proved challenging to resolve, which was best explained by massive protein-coding sequence convergence and high levels of incomplete lineage sorting that occurred during a rapid radiation after the Cretaceous-Paleogene mass extinction event about 66 million years ago.
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| 36. |
- Jiang, Li, et al.
(författare)
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Raman reporter-coated gold nanorods and their applications in multimodal optical imaging of cancer cells
- 2011
-
Ingår i: Analytical and Bioanalytical Chemistry. - : Springer Science and Business Media LLC. - 1618-2642 .- 1618-2650. ; 400:9, s. 2793-2800
-
Tidskriftsartikel (refereegranskat)abstract
- We report the preparation of a kind of surface-enhanced Raman scattering (SERS) tags and explore their applications in multifunctional optical imaging of cancer cells. The proposed nanoparticles (SERS tags) are prepared by connecting dye molecules directly onto the surfaces of gold nanorods through Au-S or Au-N interactions. The dye molecules are used as Raman reporters, while gold nanorods are used as enhanced materials due to their localized surface plasmon resonance effect. Multilayered polymers are further coated onto the surfaces of the nanoparticles to reach better stability and biocompatibility. Gold nanorods with different aspect ratios and different dye molecules conjugated are compared in order to achieve the diversity of SERS tags and find out the optimized condition of SERS tags with the highest signal intensity. Our experiments show that the resulting nanoparticles, which are uptaken by cancer cells, can provide not only dark field cells images but also multiplexing SERS images.
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| 37. |
- Jin, Lu, et al.
(författare)
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Quantifying freeze-melt dynamics of lakes on the Tibetan Plateau using Sentinel-1 synthetic aperture radar imagery
- 2024
-
Ingår i: Journal of Mountain Science. - 1672-6316. ; 21:3, s. 447-461
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Tidskriftsartikel (refereegranskat)abstract
- The ice phenology of alpine lakes on the Tibetan Plateau (TP) is a rapid and direct responder to climate changes, and the variations in lake ice exhibit high temporal frequency characteristics. MODIS and passive microwave data are widely used to monitor lake ice changes with high temporal resolution. However, the low spatial resolutions make it difficult to effectively quantify the freeze-melt dynamics of lakes. This work used Sentinel-1 synthetic aperture radar (SAR) data to derive highresolution ice maps (about 6 days), then with the aid of Sentinel-2 optical images to quantify freeze-melt processes in three typical lakes on the TP (e.g. Selin Co, Ayakekumu Lake, and Nam Co). The results showed that three lakes had an average annual ice period of 125–157 days and a complete ice cover period of 72–115 days, from 2018 to 2022. They exhibit different ice phenology patterns. Nam Co is characterized by repeated episodes of freezing, melting, and refreezing, resulting in a prolonged freeze-up period. Meanwhile, the break-up period of Nam Co lasts for a longer duration (about 19 days), and the break-up exhibits a smooth process. Similarly, Ayakekumu Lake showed more significant inter-annual fluctuations in the freeze-up period, with deviations of up to 28 days observed among different years. Compared to the other two lakes, Selin Co experienced a relatively short freeze-up and break-up period. In short, Sentinel-1 SAR data can effectively monitor the weekly and seasonal variations in lake ice on the TP. Particularly, this data facilitates quantification of the freeze-melt dynamics.
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| 38. |
- Jones, Benedict C, et al.
(författare)
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To which world regions does the valence-dominance model of social perception apply?
- 2021
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Ingår i: Nature Human Behaviour. - : Springer Science and Business Media LLC. - 2397-3374. ; 5:1, s. 159-169
-
Tidskriftsartikel (refereegranskat)abstract
- Over the past 10 years, Oosterhof and Todorov's valence-dominance model has emerged as the most prominent account of how people evaluate faces on social dimensions. In this model, two dimensions (valence and dominance) underpin social judgements of faces. Because this model has primarily been developed and tested in Western regions, it is unclear whether these findings apply to other regions. We addressed this question by replicating Oosterhof and Todorov's methodology across 11 world regions, 41 countries and 11,570 participants. When we used Oosterhof and Todorov's original analysis strategy, the valence-dominance model generalized across regions. When we used an alternative methodology to allow for correlated dimensions, we observed much less generalization. Collectively, these results suggest that, while the valence-dominance model generalizes very well across regions when dimensions are forced to be orthogonal, regional differences are revealed when we use different extraction methods and correlate and rotate the dimension reduction solution. PROTOCOL REGISTRATION: The stage 1 protocol for this Registered Report was accepted in principle on 5 November 2018. The protocol, as accepted by the journal, can be found at https://doi.org/10.6084/m9.figshare.7611443.v1 .
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| 39. |
- Li, Cai, et al.
(författare)
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Two Antarctic penguin genomes reveal insights into their evolutionary history and molecular changes related to the Antarctic environment
- 2014
-
Ingår i: GigaScience. - 2047-217X. ; 3
-
Tidskriftsartikel (refereegranskat)abstract
- Background: Penguins are flightless aquatic birds widely distributed in the Southern Hemisphere. The distinctive morphological and physiological features of penguins allow them to live an aquatic life, and some of them have successfully adapted to the hostile environments in Antarctica. To study the phylogenetic and population history of penguins and the molecular basis of their adaptations to Antarctica, we sequenced the genomes of the two Antarctic dwelling penguin species, the Adelie penguin [Pygoscelis adeliae] and emperor penguin [Aptenodytes forsteri]. Results: Phylogenetic dating suggests that early penguins arose similar to 60 million years ago, coinciding with a period of global warming. Analysis of effective population sizes reveals that the two penguin species experienced population expansions from similar to 1 million years ago to similar to 100 thousand years ago, but responded differently to the climatic cooling of the last glacial period. Comparative genomic analyses with other available avian genomes identified molecular changes in genes related to epidermal structure, phototransduction, lipid metabolism, and forelimb morphology. Conclusions: Our sequencing and initial analyses of the first two penguin genomes provide insights into the timing of penguin origin, fluctuations in effective population sizes of the two penguin species over the past 10 million years, and the potential associations between these biological patterns and global climate change. The molecular changes compared with other avian genomes reflect both shared and diverse adaptations of the two penguin species to the Antarctic environment.
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| 40. |
- Li, Youbing, et al.
(författare)
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Single-Atom-Thick Active Layers Realized in Nanolaminated Ti-3(AlxCu1-x)C-2 and Its Artificial Enzyme Behavior
- 2019
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Ingår i: ACS Nano. - : AMER CHEMICAL SOC. - 1936-0851 .- 1936-086X. ; 13:8, s. 9198-9205
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Tidskriftsartikel (refereegranskat)abstract
- A Ti-3(AlxCu1-x)C-2 phase with Cu atoms with a degree of ordering in the A plane is synthesized through the A site replacement reaction in CuCl2 molten salt. The weakly bonded single -atom -thick Cu layers in a Ti-3(AlxCu1-x)C-2 MAX phase provide actives sites for catalysis chemistry. As -synthesized Ti-3(AlxCu1-x)C-2 presents unusual peroxidase-like catalytic activity similar to that of natural enzymes. A fabricated Ti-3(AlxCu1-x)C-2/chitosan/glassy carbon electrode biosensor prototype also exhibits a low detection limit in the electrochemical sensing of H2O2. These results have broad implications for property tailoring in a nanolaminated MAX phase by replacing the A site with late transition elements.
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| 41. |
- Liu, Qingkun, et al.
(författare)
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Switchable polarization-sensitive surface plasmon resonance of highly stable gold nanorods-liquid crystals composites
- 2011
-
Ingår i: Optoelectronic Materials and Devices VI. - Washington, D.C. : SPIE. - 9780819489616
-
Konferensbidrag (refereegranskat)abstract
- In this work, we demonstrate the bulk self-alignment of gold nanorods (GNRs) dispersed in lyotropic nematic liquid crystals (LCs) with high optical absorption coefficient at the surface plasmon resonant wavelength. The polymer-coated GNRs which show spontaneous long-range orientational ordering along the director of LC host exhibit long-term stability as well as high concentration. External magnetic field and shearing allow for alignment and realignment of the orientation of gold nanorods by changing the director of the liquid crystal matrix. This results in a switchable polarization-sensitive surface plasmon resonance exhibiting stark differences from that of the same nanorods in isotropic fluids. The devise-scale bulk nanoparticle alignment may enable optical metamaterial mass production and control of surface plasmon resonance of nanoparticles.
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| 42. |
- Lopez-Lopez, Victor, et al.
(författare)
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Liver growth prediction in ALPPS - A multicenter analysis from the international ALPPS registry
- 2022
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Ingår i: Liver international (Print). - : WILEY. - 1478-3223 .- 1478-3231. ; 42:12, s. 2815-2829
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundWhile ALPPS triggers a fast liver hypertrophy, it is still unclear which factors matter most to achieve accelerated hypertrophy within a short period of time. The aim of the study was to identify patient-intrinsic factors related to the growth of the future liver remnant (FLR).MethodsThis cohort study is composed of data derived from the International ALPPS Registry from November 2011 and October 2018. We analyse the influence of demographic, tumour type and perioperative data on the growth of the FLR. The volume of the FLR was calculated in millilitre and percentage using computed-tomography (CT) scans before and after stage 1, both according to Vauthey formula.ResultsA total of 734 patients were included from 99 centres. The median sFLR at stage 1 and stage 2 was 0.23 (IQR, 0.18–0.28) and 0.39 (IQR: 0.31–0.46), respectively. The variables associated with a lower increase from sFLR1 to sFLR2 were age˃68 years (p = .02), height ˃1.76 m (p ˂ .01), weight ˃83 kg (p ˂ .01), BMI˃28 (p ˂ .01), male gender (p ˂ .01), antihypertensive therapy (p ˂ .01), operation time ˃370 minutes (p ˂ .01) and hospital stay˃14 days (p ˂ .01). The time required to reach sufficient volume for stage 2, male gender accounts 40.3% in group ˂7 days, compared with 50% of female, and female present 15.3% in group ˃14 days compared with 20.6% of male.ConclusionsHeight, weight, FLR size and gender could be the variables that most constantly influence both daily growths, the interstage increase and the standardized FLR before the second stage.
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| 43. |
- Lu, Qianqian, et al.
(författare)
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Ebselen, a multi-target compound : its effects on biological processes and diseases
- 2021
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Ingår i: Expert Reviews in Molecular Medicine. - : Cambridge University Press. - 1462-3994. ; 23
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Forskningsöversikt (refereegranskat)abstract
- Ebselen is a well-known synthetic compound mimicking glutathione peroxidase (GPx), which catalyses some vital reactions that protect against oxidative damage. Based on a large number of in vivo and in vitro studies, various mechanisms have been proposed to explain its actions on multiple targets. It targets thiol-related compounds, including cysteine, glutathione, and thiol proteins (e.g., thioredoxin and thioredoxin reductase). Owing to this, ebselen is a unique multifunctional agent with important effects on inflammation, apoptosis, oxidative stress, cell differentiation, immune regulation and neurodegenerative disease, with anti-microbial, detoxifying and anti-tumour activity. This review summarises the current understanding of the multiple biological processes and molecules targeted by ebselen, and its pharmacological applications.
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| 44. |
- Lu, Xingyuan, et al.
(författare)
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Phase detection of coherence singularities and determination of the topological charge of a partially coherent vortex beam
- 2019
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 114:20
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Tidskriftsartikel (refereegranskat)abstract
- In the theory of partial coherence, coherence singularities can occur in the spectral degree of coherence (SDOC): in case the fields at two different points are completely uncorrelated, the phase of the SDOC is undefined. For a partially coherent vortex beam, the detection of coherence singularities is linked to the measurement of topological charge, whose magnitude equals the number of ring dislocations in its far field amplitude. However, the phase distribution of coherence singularities is rarely mentioned in the literature and the amplitude distribution can hardly reflect the sign of topological charge. In this letter, we present a phase-analysis method for measuring the coherence singularities by introducing a movable perturbation at a certain point in an illumination window of a finite size. Using the proposed method, we measure experimentally the coherence singularities of a partially coherent vortex beam in the focal plane. From the results, the magnitude and sign of the topological charge can be determined simultaneously from the phase distribution of the coherence singularities. Our results can find application in information transmission.
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| 45. |
- Lu, Yuzheng, et al.
(författare)
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Progress in Electrolyte-Free Fuel Cells
- 2016
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Ingår i: FRONTIERS IN ENERGY RESEARCH. - : FRONTIERS MEDIA SA. - 2296-598X. ; 4
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Forskningsöversikt (refereegranskat)abstract
- Solid oxide fuel cell (SOFC) represents a clean electrochemical energy conversion technology with characteristics of high conversion efficiency and low emissions. It is one of the most important new energy technologies in the future. However, the manufacture of SOFCs based on the structure of anode/electrolyte/cathode is complicated and time-consuming. Thus, the cost for the entire fabrication and technology is too high to be affordable, and challenges still hinder commercialization. Recently, a novel type of electrolyte-free fuel cell (EFFC) with single component was invented, which could be the potential candidate for the next generation of advanced fuel cells. This paper briefly introduces the EFFC, working principle, performance, and advantages with updated research progress. A number of key R&D issues about EFFCs have been addressed, and future opportunities and challenges are discussed.
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| 46. |
- Lyu, Chuang, et al.
(författare)
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Expression and regulation of FRMD6 in mouse DRG neurons and spinal cord after nerve injury
- 2020
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Ingår i: Scientific Reports. - : NATURE PUBLISHING GROUP. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- FRMD6, a member of the group of FERM-domain proteins, is involved both in communication between cells, interactions with extracellular matrix, cellular apoptotic and regenerative mechanisms. FRMD6 was first discovered in the rodent sciatic nerve, and in the present immunohistochemical study we investigated the distribution of FRMD6 in the dorsal root ganglia (DRGs), sciatic nerve and spinal cord following sciatic nerve injury. FRMD6-immunoreactivity was found in the cytoplasm, nucleus or both, and in a majority of DRG neurons. FRMD6-immunoreactivity co-existed with several well-known neuronal markers, including calcitonin gene-related peptide, isolectin B4 and neurofilament 200 in mouse DRGs. After peripheral nerve injury, the FRMD6 mRNA levels and the overall percentage of FRMD6-positive neuron profiles (NPs) were decreased in ipsilateral lumbar DRGs, the latter mainly affecting small size neurons with cytoplasmic localization. Conversely, the proportion of NPs with nuclear FRMD6-immunoreactivity was significantly increased. In the sciatic nerve, FRMD6-immunoreactivity was observed in non-neuronal cells and in axons, and accumulated proximally to a ligation of the nerve. In the spinal cord FRMD6-immunoreactivity was detected in neurons in both dorsal and ventral horns, and was upregulated in ipsilateral dorsal horn after peripheral nerve axotomy. Our results demonstrate that FRMD6 is strictly regulated by peripheral nerve injury at the spinal level.
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| 47. |
- Martin, Alma, et al.
(författare)
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In Situ Transformation of Electrospun Nanofibers into Nanofiber-Reinforced Hydrogels
- 2022
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 12:14
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Tidskriftsartikel (refereegranskat)abstract
- Nanofiber-reinforced hydrogels have recently gained attention in biomedical engineering. Such three-dimensional scaffolds show the mechanical strength and toughness of fibers while benefiting from the cooling and absorbing properties of hydrogels as well as a large pore size, potentially aiding cell migration. While many of such systems are prepared by complicated processes where fibers are produced separately to later be embedded in a hydrogel, we here provide proof of concept for a one-step solution. In more detail, we produced core-shell nanofibers from the natural proteins zein and gelatin by coaxial electrospinning. Upon hydration, the nanofibers were capable of directly transforming into a nanofiber-reinforced hydrogel, where the nanofibrous structure was retained by the zein core, while the gelatin-based shell turned into a hydrogel matrix. Our nanofiber-hydrogel composite showed swelling to ~800% of its original volume and water uptake of up to ~2500% in weight. The physical integrity of the nanofiber-reinforced hydrogel was found to be significantly improved in comparison to a hydrogel system without nanofibers. Additionally, tetracycline hydrochloride was incorporated into the fibers as an antimicrobial agent, and antimicrobial activity against Staphylococcus aureus and Escherichia coli was confirmed.
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| 48. |
- Martin, Alma, et al.
(författare)
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Zein-polycaprolactone core–shell nanofibers for wound healing
- 2022
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Ingår i: International Journal of Pharmaceutics. - : Elsevier BV. - 0378-5173. ; 621
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Tidskriftsartikel (refereegranskat)abstract
- In a previous study, we developed electrospun antimicrobial microfiber scaffolds for wound healing composed of a core of zein protein and a shell containing polyethylene oxide. While providing a promising platform for composite nanofiber design, the scaffolds showed low tensile strengths, insufficient water stability, as well as burst release of the antimicrobial drug tetracycline hydrochloride, properties which are not ideal for the use of the scaffolds as wound dressings. Therefore, the aim of the present study was to develop fibers with enhanced mechanical strength and water stability, also displaying sustained release of tetracycline hydrochloride. Zein was chosen as core material, while the shell was formed by the hydrophobic polymer polycaprolactone, either alone or in combination with polyethylene oxide. As compared to control fibers of pristine polycaprolactone, the zein-polycaprolactone fibers exhibited a reduced diameter and hydrophobicity, which is beneficial for cell attachment and wound closure. Such fibers also demonstrated sustained release of tetracycline hydrochloride, as well as water stability, ductility, high mechanical strength and fibroblast attachment, hence representing a step towards the development of biodegradable wound dressings with prolonged drug release, which can be left on the wound for a longer time.
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| 49. |
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| 50. |
- Proletov, Ian, et al.
(författare)
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Primary and secondary glomerulonephritides 1.
- 2014
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Ingår i: Nephrology, dialysis, transplantation : official publication of the European Dialysis and Transplant Association - European Renal Association. - : Oxford University Press (OUP). - 1460-2385. ; 29 Suppl 3:May, s. 186-200
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Tidskriftsartikel (refereegranskat)
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