1. |
- 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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2. |
- Chen, Zhishan, et al.
(författare)
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Fine-mapping analysis including over 254 000 East Asian and European descendants identifies 136 putative colorectal cancer susceptibility genes
- 2024
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 15:1
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified more than 200 common genetic variants independently associated with colorectal cancer (CRC) risk, but the causal variants and target genes are mostly unknown. We sought to fine-map all known CRC risk loci using GWAS data from 100,204 cases and 154,587 controls of East Asian and European ancestry. Our stepwise conditional analyses revealed 238 independent association signals of CRC risk, each with a set of credible causal variants (CCVs), of which 28 signals had a single CCV. Our cis-eQTL/mQTL and colocalization analyses using colorectal tissue-specific transcriptome and methylome data separately from 1299 and 321 individuals, along with functional genomic investigation, uncovered 136 putative CRC susceptibility genes, including 56 genes not previously reported. Analyses of single-cell RNA-seq data from colorectal tissues revealed 17 putative CRC susceptibility genes with distinct expression patterns in specific cell types. Analyses of whole exome sequencing data provided additional support for several target genes identified in this study as CRC susceptibility genes. Enrichment analyses of the 136 genes uncover pathways not previously linked to CRC risk. Our study substantially expanded association signals for CRC and provided additional insight into the biological mechanisms underlying CRC development.
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3. |
- Li, Yuhan, et al.
(författare)
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Understanding the electrochemical properties of A(2)MSiO(4) (A = Li and Na; M = Fe, Mn, Co and Ni) and the Na doping effect on Li2MSiO4 from first-principles calculations
- 2016
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 4:44, s. 17455-17463
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Tidskriftsartikel (refereegranskat)abstract
- To explore the feasibility of regarding silicate materials as sustainable cathode materials for rechargeable Na ion batteries, the voltage plateaus, cycling stabilities, electrical conductivities and ionic conductivities of Li2MSiO4 and Na2MSiO4 (M = Fe, Mn, Co and Ni) are investigated by first principles calculations. The calculated electrochemical performance of silicate materials gives reasonable explanations for the poor capacity retention of Li2MnSiO4 as well as the reason why Li2FeSiO4 and Li2CoSiO4 exchange only one Li ion per formula unit. In comparison with Na2MSiO4, Li2MSiO4 presents higher voltage and better cycling stability. However, Na2MSiO4 displays higher electrical and ionic conductivities. Moreover, Na2NiSiO4 also presents significant potential for application as a good cathode material for Na ion batteries, as it can deliver high voltage and reversibly exchange 1.5 Li ions per formula unit. Furthermore, to make full use of the advantages of Li2MSiO4 and Na2MSiO4, a Na doped Li1.5Na0.5MSiO4 system is explored as well. The results suggest that Na doping can improve the electronic and ionic conductivities of Li2MSiO4 materials and simultaneously maintain the voltage and cycling stability. Therefore, Na ion doping should be an effective methodology to improve the performance of Li2MSiO4 cathode materials.
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4. |
- Labadie, Julia D., et al.
(författare)
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Genome-wide association study identifies tumor anatomical site-specific risk variants for colorectal cancer survival
- 2022
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 12:1
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Tidskriftsartikel (refereegranskat)abstract
- Identification of new genetic markers may improve the prediction of colorectal cancer prognosis. Our objective was to examine genome-wide associations of germline genetic variants with disease-specific survival in an analysis of 16,964 cases of colorectal cancer. We analyzed genotype and colorectal cancer-specific survival data from a consortium of 15 studies. Approximately 7.5 million SNPs were examined under the log-additive model using Cox proportional hazards models, adjusting for clinical factors and principal components. Additionally, we ran secondary analyses stratifying by tumor site and disease stage. We used a genome-wide p-value threshold of 5 × 10–8 to assess statistical significance. No variants were statistically significantly associated with disease-specific survival in the full case analysis or in the stage-stratified analyses. Three SNPs were statistically significantly associated with disease-specific survival for cases with tumors located in the distal colon (rs698022, HR = 1.48, CI 1.30–1.69, p = 8.47 × 10–9) and the proximal colon (rs189655236, HR = 2.14, 95% CI 1.65–2.77, p = 9.19 × 10–9 and rs144717887, HR = 2.01, 95% CI 1.57–2.58, p = 3.14 × 10–8), whereas no associations were detected for rectal tumors. Findings from this large genome-wide association study highlight the potential for anatomical-site-stratified genome-wide studies to identify germline genetic risk variants associated with colorectal cancer-specific survival. Larger sample sizes and further replication efforts are needed to more fully interpret these findings.
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5. |
- Liu, Chen, et al.
(författare)
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Wear Resistance Improvement of Keeled Structure and Overlapped Distribution of Snake Scales
- 2023
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Ingår i: Journal of Bionic Engineering. - : Springer Nature. - 1672-6529 .- 2543-2141. ; 20:3, s. 1121-1131
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Tidskriftsartikel (refereegranskat)abstract
- The movement mode of snakes is crawling, and the living environment of snakes with numerous branches and stones will cause plenty of wear for the snake scales. There are plenty of surface structures and morphology on snake scales to avoid severe wear. Among them, the research towards the keeled structure on snake scales is missing. Therefore, in this research, the wear resistance improvement of the keeled structure on the snake scales and the overlapped distribution of snake scales are investigated. The keeled and smooth snake scales were 3D printed and they were distributed on the substrate in the overlapped or paralleled ways. Besides these four samples with keeled/smooth scales and overlapped/paralleled distributed, there is also a reference sample with the same thickness. Based on the tribology test, the number of grooves of samples with the keeled structures is higher than that of samples with smooth surfaces, which indicates that the keeled structure dramatically enhances the wear resistance of snake scales, especially during the wear in the vertical direction. The experiment on surface morphology greatly compromised the result of the tribology test. In addition, the bottom portion of the keeled snake scales can be protected by the keeled structure. Besides, the overlapped distribution can protect the central region of snake scales and provide double-layer protection of the snake body. Overall, the keeled structure and the overlapped distribution play a significant part in the improvement of wear resistance of the snake skin. These findings can enhance the knowledge of the reptiles-mimic surface structure and facilitate the application of military uniforms under high-wear conditions.
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6. |
- Yang, Fengmei, et al.
(författare)
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Li2FePO4F and its metal-doping for Li-ion batteries : an ab initio study
- 2014
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Ingår i: RSC Advances. - : Royal Society of Chemistry (RSC). - 2046-2069. ; 4:91, s. 50195-50201
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Tidskriftsartikel (refereegranskat)abstract
- The electrochemical properties of three isotopic Li2FePO4F compounds, as cathode materials under different space groups Pbcn, P (1) over bar and Pnma were investigated using first principle calculations. Their structures and average open circuit voltages for step delithiation reactions were explored, and the results are in good agreement with the reported experimental data. We estimate the substitution effect of Fe by Co in Pnma-Li2FePO4F. The substitution of Fe by Co in Li2Fe1-xCoxPO4F may enhance the discharge potential of the materials, and the rate of its volume change during the redox process is between 0.6% and 2.1%. Furthermore, from the projected density of states for Li2Fe0.5Co0.5PO4F, we found strong hybridization for Fe-3d and Co-3d bands near the Fermi level, which implies that the Co-doped Li2Fe1-xCoxPO4F may possess better electronic conductivity than the pure phase.
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7. |
- Zhao, Li, et al.
(författare)
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Carbon Dioxide Capture on Amine-Rich Carbonaceous Materials Derived from Glucose
- 2010
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Ingår i: CHEMSUSCHEM. - : Wiley. - 1864-5631 .- 1864-564X. ; 3, s. 840-845
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of carbonaceous materials with a high surface density of amino functions for CO2 sorption and sequestration is reported. The amino-rich carbonaceous materials are characterized by elemental analysis, N2 sorption, scanning and transmission electron microscopy, zeta potential, TGA and FTIR measurements. A detailed discussion on the use of these materials in CO2 capture is provided. The materials show significant sorption capabilities for CO2 (4.3 mmol g−1at −20 °C and 1 bar). Furthermore, they show a high apparent selectivity for CO2 over N2 at both low and high temperatures.
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