| 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. |
- Hsiung, Shih-Yi, et al.
(författare)
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Machine learning-based monosaccharide profiling for tissue-specific classification of Wolfiporia extensa samples
- 2023
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 322
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Tidskriftsartikel (refereegranskat)abstract
- Machine learning (ML) has been used for many clinical decision-making processes and diagnostic procedures in bioinformatics applications. We examined eight algorithms, including linear discriminant analysis (LDA), logistic regression (LR), k-nearest neighbor (KNN), random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), Naïve Bayes classifier (NB), and artificial neural network (ANN) models, to evaluate their classification and prediction capabilities for four tissue types in Wolfiporia extensa using their monosaccharide composition profiles. All 8 ML-based models were assessed as exemplary models with AUC exceeding 0.8. Five models, namely LDA, KNN, RF, GBM, and ANN, performed excellently in the four-tissue-type classification (AUC > 0.9). Additionally, all eight models were evaluated as good predictive models with AUC value >0.8 in the three-tissue-type classification. Notably, all 8 ML-based methods outperformed the single linear discriminant analysis (LDA) plotting method. For large sample sizes, the ML-based methods perform better than traditional regression techniques and could potentially increase the accuracy in identifying tissue samples of W. extensa.
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| 4. |
- 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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| 5. |
- 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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| 6. |
- 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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| 7. |
- 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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| 8. |
- Arstikaitis, Pamela, et al.
(författare)
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Paralemmin-1, a modulator of filopodia induction is required for spine maturation
- 2008
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Ingår i: Molecular Biology of the Cell. - : ASCB. - 1059-1524 .- 1939-4586. ; 19:5, s. 2026-2038
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic filopodia are thought to participate in neuronal contact formation and development of dendritic spines, however, molecules that regulate filopodia extension and their maturation to spines remain largely unknown. Here we identify paralemmin-1 as a regulator of filopodia induction and spine maturation. Paralemmin-1 localizes to dendritic membranes, and its ability to induce filopodia and recruit synaptic elements to contact sites requires protein acylation. Effects of paralemmin-1 on synapse maturation are modulated by alternative splicing that regulates spine formation and recruitment of AMPA-type glutamate receptors. Paralemmin-1 enrichment at the plasma membrane is subject to rapid changes in neuronal excitability, and this process controls neuronal activity-driven effects on protrusion expansion. Knockdown of paralemmin-1 in developing neurons reduces the number of filopodia and spines formed and diminishes the effects of Shank1b on the transformation of existing filopodia into spines. Our study identifies a key role for paralemmin-1 in spine maturation through modulation of filopodia induction.
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| 9. |
- Birney, Ewan, et al.
(författare)
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Identification and analysis of functional elements in 1% of the human genome by the ENCODE pilot project
- 2007
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 447:7146, s. 799-816
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Tidskriftsartikel (refereegranskat)abstract
- We report the generation and analysis of functional data from multiple, diverse experiments performed on a targeted 1% of the human genome as part of the pilot phase of the ENCODE Project. These data have been further integrated and augmented by a number of evolutionary and computational analyses. Together, our results advance the collective knowledge about human genome function in several major areas. First, our studies provide convincing evidence that the genome is pervasively transcribed, such that the majority of its bases can be found in primary transcripts, including non-protein-coding transcripts, and those that extensively overlap one another. Second, systematic examination of transcriptional regulation has yielded new understanding about transcription start sites, including their relationship to specific regulatory sequences and features of chromatin accessibility and histone modification. Third, a more sophisticated view of chromatin structure has emerged, including its inter-relationship with DNA replication and transcriptional regulation. Finally, integration of these new sources of information, in particular with respect to mammalian evolution based on inter- and intra-species sequence comparisons, has yielded new mechanistic and evolutionary insights concerning the functional landscape of the human genome. Together, these studies are defining a path for pursuit of a more comprehensive characterization of human genome function.
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| 10. |
- Bogg, Lennart, et al.
(författare)
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Dramatic Increase of Cesarean Deliveries in the Midst of Health Reforms in Rural China
- 2010
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Ingår i: Social Science and Medicine. - : Elsevier. - 0277-9536 .- 1873-5347. ; 70:10, s. 1544-1549
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Tidskriftsartikel (refereegranskat)abstract
- Cesarean delivery (CD) rates were until recently low in rural China where the population lacked healthinsurance. In July 2003 the New Cooperative Medical Scheme (NCMS) was introduced. We report findingsfrom a health systems study carried out in the EC-funded project ‘‘Structural hinders to andpromoters of good maternal care in rural China’’ in central and western China. The purpose was toanalyze how CD rates changed with the increased level of funding of the NCMS.The research design was a natural experiment. Quantitative demographic, administrative and accountsdata for 2001–2007 were collected in five counties from the county public health bureaux, the countyNCMS offices, the county statistical offices and the Maternal and Child Health (MCH) hospitals, usinga structured data collection form. We found that the CD rates increased in four of the five counties in theperiod 2004–2007 by 36%, 53%, 61% and 131% respectively. In the fifth county the CD rate remained highat 60%. The revenue from CD made up 72–85% of total delivery fee revenue. CD fee revenue increased by97%, 239% and 408% in the three counties with available data; a higher increase than in general healthcare revenue. Our conclusion is that the design of NCMS, the provider payment systems, and therevenue-related bonus systems for doctors need to be studied to rein in the unhealthy increases in ruralCD rates.
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| 11. |
- Chang, Ching-Wen, et al.
(författare)
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Problematic smartphone use and two types of problematic use of the internet and self-stigma among people with substance use disorders
- 2023
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Ingår i: Addictive Behaviours. - : Elsevier. - 0306-4603 .- 1873-6327. ; 147
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND AND AIMS: Guided by the Interaction of Person-Affect-Cognition-Execution (I-PACE) model and a self-stigma framework, this study aimed to investigate relationships between cognitive and affective self-stigma and behavioral self-stigma, problematic use of internet (PUI), and problematic smartphone use (PSU) among people with substance use disorders (SUDs). It also examined mediating roles for affective self-stigma in the relationships between cognitive self-stigma and behavioral self-stigma/PUI/PSU.METHODS: Using a cross-sectional design, 530 participants diagnosed with SUDs in Taiwan were recruited from a psychiatric center in Taiwan. Mediation models were investigated using the Hayes' Process Macro Model 4.RESULTS: Mediation analyses indicated that cognitive self-stigma was directly associated with behavioral self-stigma (p < 0.001), but not with either types of PUI or PSU (p-values ranging from 0.41 to 0.76). Affective self-stigma was directly related to behavioral self-stigma (p < 0.001), two types of PUI, and PSU (β = 0.24-0.30; all p < 0.001); cognitive self-stigma was indirectly associated with behavioral self-stigma (β = 0.53; 95 % bootstrapping CI = 0.46, 0.60), two types of PUI, and PSU (β = 0.20-0.25; 95 % bootstrapping CI = 0.08-0.14, 0.31-0.37) via a mediating effect of affective self-stigma.DISCUSSION AND CONCLUSION: Findings support the I-PACE model in a self-stigma context. The findings also suggest that addressing affective self-stigma may help prevent or reduce behavioral self-stigma, PUI, and PSU among people with SUDs. Longitudinal studies are warranted to investigate over time relationships between self-stigma and PUI/PSU in people with SUDs.
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| 12. |
- Ding, Haoming, et al.
(författare)
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Chemical scissor-mediated structural editing of layered transition metal carbides
- 2023
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Ingår i: Science. - : AMER ASSOC ADVANCEMENT SCIENCE. - 0036-8075 .- 1095-9203. ; 379:6637, s. 1130-1135
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Tidskriftsartikel (refereegranskat)abstract
- Intercalated layered materials offer distinctive properties and serve as precursors for important two-dimensional (2D) materials. However, intercalation of non-van der Waals structures, which can expand the family of 2D materials, is difficult. We report a structural editing protocol for layered carbides (MAX phases) and their 2D derivatives (MXenes). Gap-opening and species-intercalating stages were respectively mediated by chemical scissors and intercalants, which created a large family of MAX phases with unconventional elements and structures, as well as MXenes with versatile terminals. The removal of terminals in MXenes with metal scissors and then the stitching of 2D carbide nanosheets with atom intercalation leads to the reconstruction of MAX phases and a family of metal-intercalated 2D carbides, both of which may drive advances in fields ranging from energy to printed electronics.
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| 13. |
- Dore, Vincent, et al.
(författare)
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CenTauRz : A standardized quantification of tau PET scans
- 2022
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Ingår i: Alzheimer's and Dementia. - : Wiley. - 1552-5260 .- 1552-5279. ; 18:S1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Over the past decade, several PET tracers were developed to visualise and quantify tau pathology in vivo. However, all these tracers have distinct off-target binding, different dynamic ranges and likely different levels of non-specific binding resulting in large variability in semiquantification. We propose to standardise the sampling and the quantification across all available tau tracers. Method: 549 participants underwent tau scans with either 18F-FTP (Cognitively Unimpaired (CU)=54/AD=14), 18F-MK6240 (CU=186/AD=89), 18F-PI2620 (CU=17/AD=21), 18F-PM-PBB3 (CU=30/AD=28), 18F-GTP1 (CU=7/AD=38) or 18F-RO948 (CU=35/AD=30). All CU individuals were Aβ- and all AD were Aβ+. The tau scans were spatially normalized using CapAIBL and the cerebellar cortex was used as reference region. We constructed a “universal” tau mask from the intersection of all the specific tau tracer masks, after subtracting AD from CU. All tau PET studies were sampled with a Mesial Temporal (MTL) and a Meta Temporal (MetaT) composites constrained by the universal mask. For each tracer and in composite, the mean and standard deviation of the Aβ- CU SUVR for each tau tracer were used to generate z-scores (CenTauRz). Result: Using a threshold of 2 CenTauRz in the MetaT regions, all tracers highly discriminated Aβ+ AD from Aβ- CU (ACC=[0.94-1], sens=[0.84-1], spec=[0.96-1]) with mean CenTauRz for the different AD cohorts ranging from 8 to 14. Lower accuracy was observed in the MTL (ACC=[0.78-1]) due to lower sensitivity in some cohorts [0.65-1] however, the specificity was similar to that in the MetaT composite (spec=[0.94,1]). Conclusion: All tracers exhibited comparably high discriminative power to separate Aβ+ AD from Aβ- CU, where AD Aβ+ displayed a consistent range of CenTauRz across tracers. However, there were some differences between cohorts. For example, different PET scanners, with different sensitivities were used. For some cohorts, scans were selected as extreme representative cases, while for others the scans were more representative of clinical settings, with AD patients at early stages (with low or negative tau scans) or with suspected hippocampal sparing subtype that likely explains the lower accuracy in the MTL for some cohorts. Further studies with larger cohorts to validate the universal mask and CenTauRz scale are ongoing.
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| 14. |
- Duan, Yongchang, et al.
(författare)
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Swimming exercise ameliorates hypertension-induced kidney dysfunction via alleviating renal interstitial fibrosis and apoptosis
- 2021
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Ingår i: Kidney and Blood Pressure Research. - : S. Karger AG. - 1423-0143 .- 1420-4096. ; 46:2, s. 219-228
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hypertensive nephropathy is one of the major causes of ESRD. Exercise has been considered a nonpathological therapy for hypertension and its complications, yet mechanisms remain unclear. We sought to investigate whether periodic swimming could ameliorate hypertension-induced kidney dysfunction and its underlying mechanisms. Methods: Four-week male spontaneously hypertensive rats (SHRs) were randomly divided into the hypertension group (SHR, n = 8) and exercise group (SE, n = 8, 60 min swimming/day, 6 days per week, for 8 weeks). Wistar-Kyoto rats (WKY, n = 8) were served as a sedentary normotensive group. Bodyweight and blood pressure (BP) were recorded weekly. After 8-week sedentary or swimming exercise, lipids profile, BUN, and Cr were measured. The renal interstitial fibrosis was examined by the histopathological analysis using Masson's trichrome staining and hematoxylin and eosin staining. The kidney cell apoptosis was tested by TUNEL staining. The expressions of critical proteins responsible for the TGF-β1/Smad signaling of fibrosis, that is, TGF-β1, Smad2/3, and Smad7, as well as apoptosis related proteins, Bax and Bcl-2 in kidney cortex tissues were measured. Results: The 8-week swimming exercise reduced BP and bodyweight, lowered concentrations of BUN, and serum Cr, compared with SHR. Exercise remarkably inhibited hypertension-induced tubular degeneration, cellular cluster, and tubular cell swelling as well as glomerular degeneration in the kidney cortical tissues, attenuated renal interstitial fibrosis, and renal cell apoptosis. Moreover, expressions of TGF-β1, Smad2/3, and Bax were higher in the SHR than the WKY, which were significantly suppressed by the exercise. In contrast, hypertension-reduced expressions of Smad7 and Bcl-2 were enhanced by the swimming exercise. Strong correlations were found between kidney function indices, blood lipids, and key protein expressions. Conclusion: Our results demonstrate beneficial effects of the periodic swimming on ameliorating hypertension-induced kidney dysfunction highlighting the potential of swimming exercise as a nonpathological therapy for early prevention of hypertension-caused kidney diseases.
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| 15. |
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| 16. |
- Gu, Yeqing, et al.
(författare)
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Consumption of ultraprocessed food and development of chronic kidney disease : the Tianjin Chronic Low-Grade Systemic Inflammation and Health and UK Biobank Cohort Studies
- 2023
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Ingår i: The American journal of clinical nutrition. - : Elsevier BV. - 1938-3207 .- 0002-9165. ; 117:2, s. 373-382
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundMany ultraprocessed food (UPF)-derived by-products may play a role in the development of chronic kidney disease (CKD). Although several studies have assessed the association of UPFs with kidney function decline or CKD in various countries, no evidence has been shown in China and the United Kingdom.ObjectivesThis study aims to evaluate the association between UPF consumption and risk of CKD in 2 large cohort studies from China and the United Kingdom.MethodsIn total, 23,775 and 102,332 participants without baseline CKD were enrolled in the Tianjin Chronic Low-Grade Systemic Inflammation and Health (TCLSIH) and UK Biobank cohort studies, respectively. Information on UPF consumption was obtained from a validated food frequency questionnaire in the TCLSIH and 24-h dietary recalls in the UK Biobank cohort. CKD was defined as an estimated glomerular filtration rate of ResultsAfter a median follow-up of 4.0 and 10.1 y, the incidence rates of CKD were around 1.1% and 1.7% in the TCLSIH and UK Biobank cohorts, respectively. The multivariable hazard ratio [95% confidence interval] of CKD across increasing quartiles (quartiles 1–4) of UPF consumption were 1 (reference), 1.24 (0.89, 1.72), 1.30 (0.91, 1.87), and 1.58 (1.07, 2.34) (P for trend = 0.02) in the TCLSIH cohort and 1 (reference), 1.14 (1.00, 1.31), 1.16 (1.01, 1.33), and 1.25 (1.09, 1.43) (P for trend < 0.01) in the UK Biobank cohort, respectively.ConclusionsOur finding indicated that higher UPF consumption is associated with a higher risk of CKD. Moreover, restricting UPF consumption may potentially benefit the prevention of CKD. Further clinical trials are required to clarify the causality.
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| 17. |
- Han, Kun, et al.
(författare)
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Enhanced Metal-Insulator Transition in Freestanding VO2 Down to 5 nm Thickness
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 13:14, s. 16688-16693
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Tidskriftsartikel (refereegranskat)abstract
- Ultrathin freestanding membranes with a pronounced metal-insulator transition (MIT) have huge potential for future flexible electronic applications as well as provide a unique aspect for the study of lattice-electron interplay. However, the reduction of the thickness to an ultrathin region (a few nm) is typically detrimental to the MIT in epitaxial films, and even catastrophic for their freestanding form. Here, we report an enhanced MIT in VO2-based freestanding membranes, with a lateral size up to millimeters and the VO2 thickness down to 5 nm. The VO2 membranes were detached by dissolving a Sr3Al2O6 sacrificial layer between the VO2 thin film and the c-Al2O3(0001) substrate, allowing the transfer onto arbitrary surfaces. Furthermore, the MIT in the VO2 membrane was greatly enhanced by inserting an intermediate Al2O3 buffer layer. In comparison with the best available ultrathin VO2 membranes, the enhancement of MIT is over 400% at a 5 nm VO2 thickness and more than 1 order of magnitude for VO2 above 10 nm. Our study widens the spectrum of functionality in ultrathin and large-scale membranes and enables the potential integration of MIT into flexible electronics and photonics.
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| 18. |
- Huang, Jing, et al.
(författare)
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Differences in driver takeover performance and physiological responses in conditionally automated driving: Links to emotional instability
- 2024
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Ingår i: Transportation Research Part F: Traffic Psychology and Behaviour. - 1369-8478. ; 105, s. 73-86
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Tidskriftsartikel (refereegranskat)abstract
- When the automated driving system reaches its technical limit, drivers will have to take over control from the vehicle within a limited time. The drivers’ emotional instability may affect whether they can safely control the vehicle during takeover transitions. Accordingly, this paper explores the association between emotional instability and physiological responses and driver takeover performance. 42 drivers engaged in negative emotion induced by movie clips were involved in a sequence of takeover events in a driving simulator. Personality questionnaires were used to assess the driver's level of emotional instability. Their physiological data before the takeover request (TOR) and operational behavior data fragments for the takeover process were extracted. The results demonstrated that integration of subjective evaluations with electroencephalogram (EEG) and electrocardiogram (ECG) signals allows for more objective measurement of drivers’ level of emotional instability. The statistical analyses indicated that emotional instability has a significant effect on drivers’ heartbeat interval, heart rate, the frequency bands of θ(4–8 Hz), α(8–12 Hz), β(13–30 Hz), γ (30–50 Hz) and lateral takeover performance. Those findings of differences in driver physiological responses and takeover performance under emotional instability may provide additional support for the design of driver state monitoring and adaptive warning systems.
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| 19. |
- Huang, Jing, et al.
(författare)
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The correlation between drivers’ road familiarity and glance behavior using real vehicle experimental data and mathematical models
- 2024
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Ingår i: Traffic Injury Prevention. - 1538-957X .- 1538-9588. ; 25:5, s. 705-713
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Tidskriftsartikel (refereegranskat)abstract
- Objective: Road familiarity is an important factor affecting drivers’ visual features. Analyzing the quantitative correlation between drivers’ road familiarity and visual features in complex environment is of great help to improve driving safety. However, there are few relevant studies. This paper takes urban plane intersection as the environmental object to explore the correlation between drivers’ glance behavior and road familiarity, and conducts research on the quantitative evaluation model of road familiarity based on this correlation. Method: First, a real vehicle experiment was carried out to record the eye movement data of 24 drivers with different road familiarity. The driver’s visual field plane was divided into 10 areas of interest (AOIs) based on the driver’s perspective. Three measures, including average glance duration, number of glances, and fixation transition probabilities between AOIs at urban plane intersections, were extracted. Finally, based on the experimental results, the driver road familiarity evaluation model was constructed using the factor analysis method. Results: There are significant differences between unfamiliar and familiar drivers regarding the average glance duration toward the forward (FW) area, the left window (LW) area, the left rearview mirror (LVM) area and the left forward (LF) area, the number of glances toward the other (OT) area, and the fixation transition probabilities of LW→RF (right forward), LF→LF, LF→FW, FW→LW, FW→FW, FW→RVM (right rearview mirror). The comprehensive evaluation results show that the accuracy rate of the driver road familiarity evaluation model reached 83%. Conclusions: This paper revealed that there is a strong correlation between drivers’ road familiarity and drivers’ glance behavior. Based on this correlation, we can include road familiarity as a part of drivers’ working status and establish a high accuracy evaluation model of driver road familiarity. The conclusion of this paper can provide some reference for the humanized design and improvement of advanced driving assistance system, which is of great significance for reducing the driving workload of drivers and improving the driving safety.
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| 20. |
- Huang, Kun, et al.
(författare)
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Effect of acidosis on adipose-derived stem cell impairment and gene expression
- 2024
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Ingår i: Regenerative Therapy. - 2352-3204. ; 25, s. 331-343
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Tidskriftsartikel (refereegranskat)abstract
- Based on disappointing results of stem cell-based application in clinical trials for patients with critical limb ischemia, we hypothesized that the acidic environment might be the key factor limiting cell survival and function. In the present study, we used microdialysis to determine presence of acidosis and metabolic imbalance in critical ischemia. Moreover, we explored the effect of extracellular acidosis on adipose-derived stem cells (ADSCs) at molecular and transcriptional level. Our data demonstrate that low pH negatively regulates cell proliferation and survival, also, it results in cell cycle arrest, mitochondrial dynamics disorder, DNA damage as well as the impairment of proangiogenic function in a pH-dependent manner. Further transcriptome profiling identified the pivotal signaling pathways and hub genes in response to acidosis. Collectively, these findings provide strong evidences for a critical role of acidosis in ADSCs impairment with ischemic condition and suggest treatments focus on tissue pH balance and acidosis-mediated hub genes may have therapeutic potential in stem cell-based application.
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| 21. |
- Huang, Kun, et al.
(författare)
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Enhanced peak growth of global vegetation and its key mechanisms
- 2018
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Ingår i: Nature Ecology and Evolution. - : Springer Science and Business Media LLC. - 2397-334X. ; 2:12, s. 1897-1905
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Tidskriftsartikel (refereegranskat)abstract
- The annual peak growth of vegetation is critical in characterizing the capacity of terrestrial ecosystem productivity and shaping the seasonality of atmospheric CO2 concentrations. The recent greening of global lands suggests an increasing trend of terrestrial vegetation growth, but whether or not the peak growth has been globally enhanced still remains unclear. Here, we use two global datasets of gross primary productivity (GPP) and a satellite-derived Normalized Difference Vegetation Index (NDVI) to characterize recent changes in annual peak vegetation growth (that is, GPPmax and NDVImax). We demonstrate that the peak in the growth of global vegetation has been linearly increasing during the past three decades. About 65% of the NDVImax variation is evenly explained by expanding croplands (21%), rising CO2 (22%) and intensifying nitrogen deposition (22%). The contribution of expanding croplands to the peak growth trend is substantiated by measurements from eddy-flux towers, sun-induced chlorophyll fluorescence and a global database of plant traits, all of which demonstrate that croplands have a higher photosynthetic capacity than other vegetation types. The large contribution of CO2 is also supported by a meta-analysis of 466 manipulative experiments and 15 terrestrial biosphere models. Furthermore, we show that the contribution of GPPmax to the change in annual GPP is less in the tropics than in other regions. These multiple lines of evidence reveal an increasing trend in the peak growth of global vegetation. The findings highlight the important roles of agricultural intensification and atmospheric changes in reshaping the seasonality of global vegetation growth.
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| 22. |
- Huang, Ke, et al.
(författare)
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Tailoring magnetic order via atomically stacking 3d/5d electrons to achieve high-performance spintronic devices
- 2020
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Ingår i: Applied Physics Reviews. - : AMER INST PHYSICS. - 1931-9401. ; 7:1
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Forskningsöversikt (refereegranskat)abstract
- The ability to tune magnetic orders, such as magnetic anisotropy and topological spin texture, is desired to achieve high-performance spintronic devices. A recent strategy has been to employ interfacial engineering techniques, such as the introduction of spin-correlated interfacial coupling, to tailor magnetic orders and achieve novel magnetic properties. We chose a unique polar-nonpolar LaMnO3/SrIrO3 superlattice because Mn (3d)/Ir (5d) oxides exhibit rich magnetic behaviors and strong spin-orbit coupling through the entanglement of their 3d and 5d electrons. Through magnetization and magnetotransport measurements, we found that the magnetic order is interface-dominated as the superlattice period is decreased. We were able to then effectively modify the magnetization, tilt of the ferromagnetic easy axis, and symmetry transition of the anisotropic magnetoresistance of the LaMnO3/SrIrO3 superlattice by introducing additional Mn (3d) and Ir (5d) interfaces. Further investigations using in-depth first-principles calculations and numerical simulations revealed that these magnetic behaviors could be understood by the 3d/5d electron correlation and Rashba spin-orbit coupling. The results reported here demonstrate a new route to synchronously engineer magnetic properties through the atomic stacking of different electrons, which would contribute to future applications in high-capacity storage devices and advanced computing.
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| 23. |
- Jansen, Willemijn J, et al.
(författare)
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Prevalence Estimates of Amyloid Abnormality Across the Alzheimer Disease Clinical Spectrum.
- 2022
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Ingår i: JAMA neurology. - : American Medical Association (AMA). - 2168-6157 .- 2168-6149. ; 79:3, s. 228-243
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Tidskriftsartikel (refereegranskat)abstract
- One characteristic histopathological event in Alzheimer disease (AD) is cerebral amyloid aggregation, which can be detected by biomarkers in cerebrospinal fluid (CSF) and on positron emission tomography (PET) scans. Prevalence estimates of amyloid pathology are important for health care planning and clinical trial design.To estimate the prevalence of amyloid abnormality in persons with normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia and to examine the potential implications of cutoff methods, biomarker modality (CSF or PET), age, sex, APOE genotype, educational level, geographical region, and dementia severity for these estimates.This cross-sectional, individual-participant pooled study included participants from 85 Amyloid Biomarker Study cohorts. Data collection was performed from January 1, 2013, to December 31, 2020. Participants had normal cognition, subjective cognitive decline, mild cognitive impairment, or clinical AD dementia. Normal cognition and subjective cognitive decline were defined by normal scores on cognitive tests, with the presence of cognitive complaints defining subjective cognitive decline. Mild cognitive impairment and clinical AD dementia were diagnosed according to published criteria.Alzheimer disease biomarkers detected on PET or in CSF.Amyloid measurements were dichotomized as normal or abnormal using cohort-provided cutoffs for CSF or PET or by visual reading for PET. Adjusted data-driven cutoffs for abnormal amyloid were calculated using gaussian mixture modeling. Prevalence of amyloid abnormality was estimated according to age, sex, cognitive status, biomarker modality, APOE carrier status, educational level, geographical location, and dementia severity using generalized estimating equations.Among the 19097 participants (mean [SD] age, 69.1 [9.8] years; 10148 women [53.1%]) included, 10139 (53.1%) underwent an amyloid PET scan and 8958 (46.9%) had an amyloid CSF measurement. Using cohort-provided cutoffs, amyloid abnormality prevalences were similar to 2015 estimates for individuals without dementia and were similar across PET- and CSF-based estimates (24%; 95% CI, 21%-28%) in participants with normal cognition, 27% (95% CI, 21%-33%) in participants with subjective cognitive decline, and 51% (95% CI, 46%-56%) in participants with mild cognitive impairment, whereas for clinical AD dementia the estimates were higher for PET than CSF (87% vs 79%; mean difference, 8%; 95% CI, 0%-16%; P=.04). Gaussian mixture modeling-based cutoffs for amyloid measures on PET scans were similar to cohort-provided cutoffs and were not adjusted. Adjusted CSF cutoffs resulted in a 10% higher amyloid abnormality prevalence than PET-based estimates in persons with normal cognition (mean difference, 9%; 95% CI, 3%-15%; P=.004), subjective cognitive decline (9%; 95% CI, 3%-15%; P=.005), and mild cognitive impairment (10%; 95% CI, 3%-17%; P=.004), whereas the estimates were comparable in persons with clinical AD dementia (mean difference, 4%; 95% CI, -2% to 9%; P=.18).This study found that CSF-based estimates using adjusted data-driven cutoffs were up to 10% higher than PET-based estimates in people without dementia, whereas the results were similar among people with dementia. This finding suggests that preclinical and prodromal AD may be more prevalent than previously estimated, which has important implications for clinical trial recruitment strategies and health care planning policies.
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| 24. |
- Josefson, Lennart, 1954, et al.
(författare)
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ISSC 2022 Committee V.3 - Materials and Fabrication Technology
- 2022
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Ingår i: Proceedings of the 21st International Ship and Offshore Structures Congress (ISSC 2022). ; 2, s. 163-239
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Konferensbidrag (refereegranskat)abstract
- The committee shall give an overview of current developments in materials and fabrication technologies, and identify knowledge gaps, give recommendations on how to improve design, qualification and approval processes in order to keep pace with upcoming innovations. Further, the Committee shall raise the awareness on challenges from new materials, fabrication processes and increased digitization with respect to structural reliability as well as sustainable benefits.
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| 25. |
- Lai, Qiwen, et al.
(författare)
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Hydrogen Storage Materials for Mobile and Stationary Applications : Current State of the Art
- 2015
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Ingår i: ChemSusChem. - : Wiley. - 1864-5631 .- 1864-564X. ; 8:17, s. 2789-2825
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Tidskriftsartikel (refereegranskat)abstract
- One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications. Current understanding of the fundamental principles that govern the interaction of hydrogen with these light compounds is summarized, as well as basic strategies to meet practical targets of hydrogen uptake and release. The limitation of these strategies and current understanding is also discussed and new directions proposed.
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| 26. |
- Li, Aoyong, 1993, et al.
(författare)
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An empirical analysis of dockless bike-sharing utilization and its explanatory factors: Case study from Shanghai, China
- 2020
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Ingår i: Journal of Transport Geography. - : Elsevier BV. - 0966-6923. ; 88
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Tidskriftsartikel (refereegranskat)abstract
- Revealing dockless bike-sharing utilization pattern and its explanatory factors are essential for urban planners and operators to improve the utilization and turnover of public bikes. This study explores the dockless bike-sharing utilization pattern from the perspective of bike using GPS-based bike origin-destination data collected in Shanghai, China. In this paper, utilization patterns are captured by decoupling several spatially cohesive regions with intensive bike use via non-negative matrix factorization. We then measure the utilization efficiency of bikes within each sub-region by calculating Time to booking (ToB) for each bike and explore how the built environment and social-demographic characteristics influence the bike-sharing utilization with ordinary least squares (OLS) regression and geographically weighted regression (GWR) models. The matrix factorization results indicate that the shared bikes mainly serve a certain area instead of the whole city. In addition, the GWR model shows higher explanatory power (Adjusted R2 = 0.774) than the OLS regression model (Adjusted R2 = 0.520), which suggests a close relationship between bike-sharing utilization and the selected explanatory variables. The coefficients of the GWR model reveal the spatial variations of the linkage between bike-sharing utilization and its explanatory factors across the study area. This study can shed light on understanding the demand and supply of shared bikes for rebalancing and provide support for operators to improve the dockless bike-sharing utilization efficiency.
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| 27. |
- Liang, Rong-Ran, et al.
(författare)
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Exceptionally High Perfluorooctanoic Acid Uptake in Water by a Zirconium-Based Metal-Organic Framework through Synergistic Chemical and Physical Adsorption
- 2024
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Ingår i: Journal of the American Chemical Society. - 0002-7863 .- 1520-5126. ; 146:14, s. 9811-9818
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Tidskriftsartikel (refereegranskat)abstract
- Perfluorooctanoic acid (PFOA) is an environmental contaminant ubiquitous in water resources, which as a xenobiotic and carcinogenic agent, severely endangers human health. The development of techniques for its efficient removal is therefore highly sought after. Herein, we demonstrate an unprecedented zirconium-based MOF (PCN-999) possessing Zr-6 and biformate-bridged (Zr-6)(2) clusters simultaneously, which exhibits an exceptional PFOA uptake of 1089 mg/g (2.63 mmol/g), representing a ca. 50% increase over the previous record for MOFs. Single-crystal X-ray diffraction studies and computational analysis revealed that the (Zr-6)(2) clusters offer additional open coordination sites for hosting PFOA. The coordinated PFOAs further enhance the interaction between coordinated and free PFOAs for physical adsorption, boosting the adsorption capacity to an unparalleled high standard. Our findings represent a major step forward in the fundamental understanding of the MOF-based PFOA removal mechanism, paving the way toward the rational design of next-generation adsorbents for per- and polyfluoroalkyl substance (PFAS) removal.
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| 28. |
- Lo, Sheng-Han, et al.
(författare)
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Rapid desolvation-triggered domino lattice rearrangement in a metal-organic framework
- 2020
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Ingår i: Nature Chemistry. - : Springer Science and Business Media LLC. - 1755-4330 .- 1755-4349. ; 12:1, s. 90-97
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Tidskriftsartikel (refereegranskat)abstract
- Topological transitions between considerably different phases typically require harsh conditions to collectively break chemical bonds and overcome the stress caused to the original structure by altering its correlated bond environment. In this work we present a case system that can achieve rapid rearrangement of the whole lattice of a metal-organic framework through a domino alteration of the bond connectivity under mild conditions. The system transforms from a disordered metal-organic framework with low porosity to a highly porous and crystalline isomer within 40s following activation (solvent exchange and desolvation), resulting in a substantial increase in surface area from 725 to 2,749m(2)g(-1). Spectroscopic measurements show that this counter-intuitive lattice rearrangement involves a metastable intermediate that results from solvent removal on coordinatively unsaturated metal sites. This disordered-crystalline switch between two topological distinct metal-organic frameworks is shown to be reversible over four cycles through activation and reimmersion in polar solvents. A disordered metal-organic framework converts into a more porous, crystalline phase within 40s following solvent exchange and desolvation. The rapid domino rearrangement of the whole lattice, which involves carboxylate migration on coordinatively unsaturated metal sites, is accompanied by a substantial increase in surface area.
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| 29. |
- Qian, Xukun, et al.
(författare)
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Structure stability of metal-organic framework MIL-53 (Al) in aqueous solutions
- 2013
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 38:36, s. 16710-16715
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Tidskriftsartikel (refereegranskat)abstract
- The structural stability of MIL-53 (Al) in different pH aqueous solutions from room temperature to 100 degrees C has been investigated. Experimental results show MIL-53 (Al) is stable and highly resistant to hydrolysis in neutral and acidic solutions. It can retain its crystallinity and permanent porosity without structural collapse. The good structure stability of MIL-53 (Al) to aqueous solutions is quite unusual among the MOFs. The nitrogen adsorption for the soaked frameworks show a typical type I isotherm. In basic aqueous solution, MIL-53 (Al) undergoes structure transformation.
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| 30. |
- Sikkema, Lisa, et al.
(författare)
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An integrated cell atlas of the lung in health and disease
- 2023
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Ingår i: Nature Medicine. - : Springer Nature. - 1078-8956 .- 1546-170X. ; 29:6, s. 1563-1577
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Tidskriftsartikel (refereegranskat)abstract
- Single-cell technologies have transformed our understanding of human tissues. Yet, studies typically capture only a limited number of donors and disagree on cell type definitions. Integrating many single-cell datasets can address these limitations of individual studies and capture the variability present in the population. Here we present the integrated Human Lung Cell Atlas (HLCA), combining 49 datasets of the human respiratory system into a single atlas spanning over 2.4 million cells from 486 individuals. The HLCA presents a consensus cell type re-annotation with matching marker genes, including annotations of rare and previously undescribed cell types. Leveraging the number and diversity of individuals in the HLCA, we identify gene modules that are associated with demographic covariates such as age, sex and body mass index, as well as gene modules changing expression along the proximal-to-distal axis of the bronchial tree. Mapping new data to the HLCA enables rapid data annotation and interpretation. Using the HLCA as a reference for the study of disease, we identify shared cell states across multiple lung diseases, including SPP1 + profibrotic monocyte-derived macrophages in COVID-19, pulmonary fibrosis and lung carcinoma. Overall, the HLCA serves as an example for the development and use of large-scale, cross-dataset organ atlases within the Human Cell Atlas.
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| 31. |
- Silva, José P.B., et al.
(författare)
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Roadmap on ferroelectric hafnia- and zirconia-based materials and devices
- 2023
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Ingår i: APL Materials. - 2166-532X. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Ferroelectric hafnium and zirconium oxides have undergone rapid scientific development over the last decade, pushing them to the forefront of ultralow-power electronic systems. Maximizing the potential application in memory devices or supercapacitors of these materials requires a combined effort by the scientific community to address technical limitations, which still hinder their application. Besides their favorable intrinsic material properties, HfO2-ZrO2 materials face challenges regarding their endurance, retention, wake-up effect, and high switching voltages. In this Roadmap, we intend to combine the expertise of chemistry, physics, material, and device engineers from leading experts in the ferroelectrics research community to set the direction of travel for these binary ferroelectric oxides. Here, we present a comprehensive overview of the current state of the art and offer readers an informed perspective of where this field is heading, what challenges need to be addressed, and possible applications and prospects for further development.
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| 32. |
- Villemagne, Victor L., et al.
(författare)
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CenTauR : Toward a universal scale and masks for standardizing tau imaging studies
- 2023
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Ingår i: Alzheimer's and Dementia: Diagnosis, Assessment and Disease Monitoring. - 2352-8729. ; 15:3
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Tidskriftsartikel (refereegranskat)abstract
- INTRODUCTION: Recently, an increasing number of tau tracers have become available. There is a need to standardize quantitative tau measures across tracers, supporting a universal scale. We developed several cortical tau masks and applied them to generate a tau imaging universal scale. METHOD: One thousand forty-five participants underwent tau scans with either 18F-flortaucipir, 18F-MK6240, 18F-PI2620, 18F-PM-PBB3, 18F-GTP1, or 18F-RO948. The universal mask was generated from cognitively unimpaired amyloid beta (Aβ)− subjects and Alzheimer's disease (AD) patients with Aβ+. Four additional regional cortical masks were defined within the constraints of the universal mask. A universal scale, the CenTauRz, was constructed. RESULTS: None of the regions known to display off-target signal were included in the masks. The CenTauRz allows robust discrimination between low and high levels of tau deposits. DISCUSSION: We constructed several tau-specific cortical masks for the AD continuum and a universal standard scale designed to capture the location and degree of abnormality that can be applied across tracers and across centers. The masks are freely available at https://www.gaain.org/centaur-project.
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| 33. |
- Wang, Hao, et al.
(författare)
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Preparation and Properties of Microporous Nickel with High Porosity
- 2023
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Ingår i: Rare Metal Materials and Engineering. - : Northwest Institute for Nonferrous Metal Research. - 1002-185X. ; 52:3, s. 876-882
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Tidskriftsartikel (refereegranskat)abstract
- The strategy of sintered closed-hole followed by reopening was proposed to prepare the microporous nickel material with high porosity through the powder metallurgy and subsequential treatments. The carbonyl nickel powder with particle size of 1 mu m was used as raw material, and the effects of sintering process parameters on the pore properties and mechanical properties of microporous nickel were studied. Results show that the porosity measured by mercury injection method of microporous nickel is 53.7%, and the average pore diameter is 612.25 nm at the sintering temperature of 400 degrees C. After machining, the porosity measured by mercury injection method is 54.0%, and the average pore diameter is 511.37 nm, which still satisfies the requirements of engineering application. The strategy provides providing a new approach for the preparation of microporous nickel and other porous metal materials.
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| 34. |
- Wu, Renbing, et al.
(författare)
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Pt nanodendrites anchored on bamboo-shaped carbon nanofiber arrays as highly efficient electrocatalyst for oxygen reduction reaction
- 2013
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Ingår i: International journal of hydrogen energy. - : Elsevier BV. - 0360-3199 .- 1879-3487. ; 38:36, s. 16677-16684
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Tidskriftsartikel (refereegranskat)abstract
- In order to improve the Pt utilization and enhance their catalytic performance in fuel cells, a novel composite electrode composed of single-crystalline Pt nanodendrites and support constructed by bamboo-shaped carbon nanofiber arrays (CNFAs) on carbon paper, is reported. This electrode is designed by growing vertically CNFAs on carbon paper via plasma enhanced chemical vapor deposition, followed by the direct synthesis of Pt nanodendrites using a simple surfactant-free aqueous solution method. Electron microscopy studies reveal that the Pt nanodendrites are uniformly high dispersed and anchored on the surface of CNFAs. Electrochemical measurements demonstrate that the resultant electrode exhibits higher electrocatalytic activity and stability for oxygen reduction reaction than commercial Pt/C catalyst, suggesting its potential application in fuel cells.
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| 35. |
- Xia, Jianyang, et al.
(författare)
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Terrestrial ecosystem model performance in simulating productivity and its vulnerability to climate change in the northern permafrost region
- 2017
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Ingår i: Journal of Geophysical Research - Biogeosciences. - 2169-8953. ; 122:2, s. 430-446
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Tidskriftsartikel (refereegranskat)abstract
- Realistic projection of future climate-carbon (C) cycle feedbacks requires better understanding and an improved representation of the C cycle in permafrost regions in the current generation of Earth system models. Here we evaluated 10 terrestrial ecosystem models for their estimates of net primary productivity (NPP) and responses to historical climate change in permafrost regions in the Northern Hemisphere. In comparison with the satellite estimate from the Moderate Resolution Imaging Spectroradiometer (MODIS; 246±6gCm-2yr-1), most models produced higher NPP (309±12gCm-2yr-1) over the permafrost region during 2000-2009. By comparing the simulated gross primary productivity (GPP) with a flux tower-based database, we found that although mean GPP among the models was only overestimated by 10% over 1982-2009, there was a twofold discrepancy among models (380 to 800gCm-2yr-1), which mainly resulted from differences in simulated maximum monthly GPP (GPPmax). Most models overestimated C use efficiency (CUE) as compared to observations at both regional and site levels. Further analysis shows that model variability of GPP and CUE are nonlinearly correlated to variability in specific leaf area and the maximum rate of carboxylation by the enzyme Rubisco at 25°C (Vcmax_25), respectively. The models also varied in their sensitivities of NPP, GPP, and CUE to historical changes in climate and atmospheric CO2 concentration. These results indicate that model predictive ability of the C cycle in permafrost regions can be improved by better representation of the processes controlling CUE and GPPmax as well as their sensitivity to climate change.
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| 36. |
- Xu, Fengqin, et al.
(författare)
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A Questionnaire Study on the Attitude towards Death of the Nursing Interns in Eight Teaching Hospitals in Jiangsu, China
- 2019
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Ingår i: BioMed Research International. - : Hindawi Publishing Corporation. - 2314-6133 .- 2314-6141. ; 2019
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Tidskriftsartikel (refereegranskat)abstract
- Introduction: Nurses play an important role in caring for dying patients. However, little is known about the attitude towards death of the registered nurses in China.Materials and Methods: A knowledge, attitude, and the practice (KAP) survey using standardized questionnaires was conducted at eight teaching hospitals in Jiangsu Province, China. In total, 366 nursing interns were recruited and 357 turned in valid response. Data about the interns' demographic characteristics and their attitudes to death in five domains, including fear of death, death avoidance, natural acceptance, approach acceptance, and escape acceptance, were collected.Results: Compared to the norms, the nursing interns had statistically significantly higher scores in the domains death avoidance, approach acceptance, and fear of death (14.9 vs. 11.1, 26.2 vs. 24.2, and 20.3 vs. 19.0, respectively); however, statistically significantly lower scores were in the domains natural acceptance and escape acceptance (18.4 vs. 22.0, and 13.6 vs. 15.1, respectively). Religious belief, experience of a deceased relative in family, death education, and family atmosphere of discussing death are positively associated with one or more domains of attitude towards death.Conclusion: The positive attitude towards death and death education before clinical practice are helpful for nursing interns when they care for dying patients. In general, the scores of attitude towards death are at a moderate level in the surveyed Chinese nursing interns. The death education for nursing students needs to be reinforced in China.
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| 37. |
- Yao, Kun, et al.
(författare)
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Bioinspired Interface Engineering for Moisture Resistance in Nacre-Mimetic Cellulose Nanofibrils/Clay Nanocomposites
- 2017
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 9:23, s. 20169-20178
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Tidskriftsartikel (refereegranskat)abstract
- The interfacial adhesion design between "mortar" and "bricks" is essential for mechanical and barrier performance of nanocellulose-based nacre-mimetic nanocomposites, especially at high moisture conditions. To address this fundamental challenge, dopamine (DA) has been conjugated to cellulose nanofibrils (CNFs) and subsequently assembled with montmorillonite (MTM) to generate layered nanocomposite films inspired by the strong adhesion of mussel adhesive proteins to inorganic surfaces under water. The selective formation of catechol/metal ion chelation and hydrogen bonding at the interface between MTM platelets and CNFs bearing DA renders transparent films with strong mechanical properties, particularly at high humidity and in wet state. Increasing the amount of conjugated DA on CNFs results in nanocomposites with increased tensile strength and modulus, up to 57.4 MPa and 1.1 GPa, respectively, after the films are swollen in water. The nanocomposites also show excellent gas barrier properties at high relative humidity (95%), complementing the multifunctional property profile.
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