| 1. |
- Liu, Yong-feng, et al.
(författare)
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Highly Soluble CsPbBr3 Perovskite Quantum Dots for Solution-Processed Light-Emission Devices
- 2021
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; , s. 1162-1174
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Tidskriftsartikel (refereegranskat)abstract
- We report on the synthesis of CsPbBr3 perovskite quantum dots (PeQDs) with a high solubility of 75 g/L in toluene and a good film-forming property, as enabled by a dense layer of didodecyldimethylammonium bromide and octanoic acid surface ligands. The crystalline and monodisperse PeQDs feature a cubic-like shape, with an edge length of 10.1 nm, and a high photoluminescence quantum yield of greater than 90% in toluene solution and 36% as a thin film. We find that the PeQDs are n-type doped following the synthesis but also that they can be p-type and additionally n-type doped by in situ electrochemistry. These combined properties render the PeQDs interesting for the emitter in solution-processed light-emitting electrochemical cells (LECs), and we report a PeQD-LEC with air-stabile electrodes that emits with a narrow emission spectrum (λpeak = 514 nm, full width at half-maximum = 24 nm) and a luminance of 250 cd/m2 at 4 V and a luminance of 1090 cd/m2 at 6.8 V. To reach this performance, it was critical to include a thin solution-processed layer comprising p-type poly(vinyl carbazole) and a tetrahexylammonium tetrafluoroborate ionic liquid between the PeQD emission layer and the anode in order to compensate for the as-synthesized n-type doping of the PeQDs.
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| 2. |
- Hosseini, Sara, et al.
(författare)
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Comparative proteomic analysis of hyphae and germinating cysts of Phytophthora pisi and Phytophthora sojae.
- 2015
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Ingår i: Journal of Proteomics. - : Elsevier BV. - 1874-3919 .- 1876-7737. ; 117, s. 24-40
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Tidskriftsartikel (refereegranskat)abstract
- The recently described oomycete pathogen Phytophthora pisi causes root rot on pea and faba bean, while the closely related Phytophthora sojae is the causal agent of soybean root and stem rot. Differences in the pathogenicity factor repertoires that enable the two species to have distinct host specificity towards pea and soybean, were studied using tandem mass spectrometry in a global proteome study of hyphae and germinating cysts in P. pisi and P. sojae. In total 2775 proteins from P. pisi and 2891 proteins from P. sojae were identified. Fifty-eight orthologous proteins were more abundant in germinated cysts of both pathogens and thus identified as candidate proteins for the infective stage. Several of these proteins were associated with lipid transport and metabolism, and energy production. Twenty-three orthologous proteins were more abundant in hyphae of both pathogens and thus identified as candidate proteins for vegetative growth. Proteins uniquely present in germinating cysts of either P. pisi or P. sojae were considered as candidates for species-specific pathogenicity factors that may be involved in host specificity. Among these proteins were serine proteases, membrane transporters and a berberine-like protein. These results significantly expand the knowledge of the expressed proteome in P. pisi and P. sojae.
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| 3. |
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| 4. |
- Chen, Baoqing, et al.
(författare)
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The Long Noncoding RNA CCAT2 Induces Chromosomal Instability Through BOP1-AURKB Signaling
- 2020
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Ingår i: Gastroenterology. - : Elsevier BV. - 0016-5085 .- 1528-0012. ; 159:6, s. 2146-2162
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Tidskriftsartikel (refereegranskat)abstract
- Background & AimsChromosomal instability (CIN) is a carcinogenesis event that promotes metastasis and resistance to therapy by unclear mechanisms. Expression of the colon cancer–associated transcript 2 gene (CCAT2), which encodes a long noncoding RNA (lncRNA), associates with CIN, but little is known about how CCAT2 lncRNA regulates this cancer enabling characteristic.MethodsWe performed cytogenetic analysis of colorectal cancer (CRC) cell lines (HCT116, KM12C/SM, and HT29) overexpressing CCAT2 and colon organoids from C57BL/6N mice with the CCAT2 transgene and without (controls). CRC cells were also analyzed by immunofluorescence microscopy, γ-H2AX, and senescence assays. CCAT2 transgene and control mice were given azoxymethane and dextran sulfate sodium to induce colon tumors. We performed gene expression array and mass spectrometry to detect downstream targets of CCAT2 lncRNA. We characterized interactions between CCAT2 with downstream proteins using MS2 pull-down, RNA immunoprecipitation, and selective 2′-hydroxyl acylation analyzed by primer extension analyses. Downstream proteins were overexpressed in CRC cells and analyzed for CIN. Gene expression levels were measured in CRC and non-tumor tissues from 5 cohorts, comprising more than 900 patients.ResultsHigh expression of CCAT2 induced CIN in CRC cell lines and increased resistance to 5-fluorouracil and oxaliplatin. Mice that expressed the CCAT2 transgene developed chromosome abnormalities, and colon organoids derived from crypt cells of these mice had a higher percentage of chromosome abnormalities compared with organoids from control mice. The transgenic mice given azoxymethane and dextran sulfate sodium developed more and larger colon polyps than control mice given these agents. Microarray analysis and mass spectrometry indicated that expression of CCAT2 increased expression of genes involved in ribosome biogenesis and protein synthesis. CCAT2 lncRNA interacted directly with and stabilized BOP1 ribosomal biogenesis factor (BOP1). CCAT2 also increased expression of MYC, which activated expression of BOP1. Overexpression of BOP1 in CRC cell lines resulted in chromosomal missegregation errors, and increased colony formation, and invasiveness, whereas BOP1 knockdown reduced viability. BOP1 promoted CIN by increasing the active form of aurora kinase B, which regulates chromosomal segregation. BOP1 was overexpressed in polyp tissues from CCAT2 transgenic mice compared with healthy tissue. CCAT2 lncRNA and BOP1 mRNA or protein were all increased in microsatellite stable tumors (characterized by CIN), but not in tumors with microsatellite instability compared with nontumor tissues. Increased levels of CCAT2 lncRNA and BOP1 mRNA correlated with each other and with shorter survival times of patients.ConclusionsWe found that overexpression of CCAT2 in colon cells promotes CIN and carcinogenesis by stabilizing and inducing expression of BOP1 an activator of aurora kinase B. Strategies to target this pathway might be developed for treatment of patients with microsatellite stable colorectal tumors.
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| 5. |
- Gao, Zhaoju, et al.
(författare)
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Short-chain ligand achieves ultra-stable CsPbX3 perovskite quantum dots for white light-emitting diodes
- 2024
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Ingår i: Applied Physics Letters. - : American Institute of Physics (AIP). - 0003-6951 .- 1077-3118. ; 124:4
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Tidskriftsartikel (refereegranskat)abstract
- All-inorganic perovskite quantum dots (PeQDs) have aroused great research interest in white light-emitting diodes (WLED) due to their excellent optoelectronic properties, but the poor stability, caused by dynamically binding long-chain capping ligands, hinders their future practical applications. To address this issue, here, we exploit short-chain butyric acid (BA) to replace long-chain oleic acid (OA) as capping ligand of CsPbX3 PeQDs by a hot-injection method. The addition of BA not only makes the morphology of CsPbBr3 PeQDs uniform and improves the crystallinity but also effectively suppresses nonradiative recombination, achieving a near unit photoluminescence quantum yield of 96%. The BA capped CsPbBr3 PeQDs exhibit high stability up to 180 d stored in ambient environment and also significantly improved resistance against polar solvent, ultra-violet lamp irradiation, and heat, which is rationalized by the strong binding capacity and shortened distance of BA to the PeQDs through ab initio calculations. Furthermore, by combining green-emission CsPbBr3 and red-emission CsPbBr0.8I2.2 PeQDs with blue GaN chip, we achieved WLEDs with excellent luminous properties, showing their great potential in practical application of wide-color-gamut display and lighting.
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| 6. |
- Gebauer, Denis, et al.
(författare)
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Proto-Calcite and Proto-Vaterite in Amorphous Calcium Carbonates
- 2010
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 49:47, s. 8889-8891
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Tidskriftsartikel (refereegranskat)abstract
- Amorphous order: Amorphous calcium carbonates (ACC) have an intrinsic structure relating to the crystalline polymorphs of calcite and vaterite. The proto-crystalline structures of calcite and vaterite (pc-ACC and pv-ACC) are analyzed by NMR (see picture), IR, and EXAFS spectroscopy, which shows that the structuring of ACC relates to the underlying pH-dependent equilibria.
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| 7. |
- Jiang, Pengfei, et al.
(författare)
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VLBI detection of the AE Aqr twin, LAMOST J024048.51+195226.9
- 2024
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Ingår i: Monthly Notices of the Royal Astronomical Society: Letters. - 1745-3925 .- 1745-3933. ; 528:1, s. L112-L116
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Tidskriftsartikel (refereegranskat)abstract
- LAMOST J024048.51+195226.9 (J0240+1952) was recently identified as the second AE Aquarii (AE Aqr)-type cataclysmic variable, possessing the fastest known rotating white dwarf. We performed a Very Long Baseline Interferometry (VLBI) observation of J0240+1952 utilizing the European VLBI Network at 1.7 GHz, to obtain the first view of the radio morphology on mas scale. Our high-resolution VLBI image clearly shows that the radio emission is compact on mas scale (≲2 AU), with no evidence for a radio jet or extended emission. The compact radio source has an average flux density of ∼0.37 mJy, and its brightness temperature is given at ∼2.3 × 107 K, confirming a non-thermal origin. The emission exhibits irregular variations on a time-scale of tens of minutes, similar to the radio flares seen in AE Aqr. The measured VLBI position of J0240+1952 is consistent with that derived from Gaia. Our results favour the model in which the radio emission is attributed to a superposition of synchrotron radiation from expanding magnetized blobs of this system.
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| 8. |
- Li, Yuan, et al.
(författare)
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Demographic histories of four spruce (Picea) species of the Qinghai-Tibetan Plateau and neighboring areas inferred from multiple nuclear loci
- 2010
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Ingår i: Molecular biology and evolution. - : Oxford University Press (OUP). - 0737-4038 .- 1537-1719. ; 27:5, s. 1001-1014
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Tidskriftsartikel (refereegranskat)abstract
- Nucleotide variation at 12 to 16 nuclear loci was studied in three spruce species from the Qinghai-Tibetan Plateau (QTP), Picea likiangensis, P. wilsonii and P. purpurea, and one species from the Tian Shan mountain range, P. schrenkiana. Silent nucleotide diversity was limited in P. schrenkiana and high in the three species from the QTP, with values higher than in boreal spruce species, despite their much more restricted distributions compared to that of the boreal species. In contrast to European boreal species that have experienced severe bottlenecks in the past, coalescent-based analysis suggests that DNA polymorphism in the species from the QTP and adjacent areas is compatible with the standard neutral model (P. likiangensis, P. wilsonii, P. schrenkiana) or with population growth (P. purpurea). In order to test if P. purpurea is a diploid hybrid of P. likiangensis and P. wilsonii, we used a combination of approaches, including model based inference of population structure, Isolation-with-Migration models and recent theoretical results on the effect of introgression on the geographic distribution of diversity. In contrast to the three other species, each of which was predominantly assigned to a single cluster in the Structure analysis, P. purpurea individuals were scattered over the three main clusters and not, as we had expected, confined to the P. likiangensis and P. wilsonii clusters. Furthermore the contribution of P. schrenkiana was by far the largest one. In agreement with this, the divergence between P. purpurea and P. schrenkiana was lower than the divergence of either P. likiangensis or P. wilsonii from P. schrenkiana. These results, together with previous ones showing that P. purpurea and P. wilsonii share the same haplotypes at both chloroplast and mitochondrial markers, suggest that P. purpurea has a complex origin, possibly involving additional species.
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| 9. |
- Pan, Zhangcheng, et al.
(författare)
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Highly stable CsPbI3 perovskite quantum dots enabled by single SiO2 coating toward down-conversion light-emitting diodes
- 2023
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Ingår i: Applied Sciences. - : MDPI. - 2076-3417. ; 13:13
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Tidskriftsartikel (refereegranskat)abstract
- All-inorganic CsPbI3 perovskite quantum dots (PeQDs) have sparked widespread research due to their excellent optoelectronic properties and facile synthesis. However, attaining highly stable CsPbI3 perovskite quantum dots (PeQDs) against heat and polar solvents still remains a challenge and hinders any further practical application. Here, by exploiting (3-aminopropyl) triethoxysilane (APTES) as the sole silica (SiO2) precursor, we report a one-step in situ synthesis of single SiO2-coated CsPbI3 (SiO2-CsPbI3) PeQDs, namely that one SiO2 particle only contains one CsPbI3 PeQD particle. The obtained SiO2-CsPbI3 PeQDs are cubic in shape, have a more uniform size distribution, and possess narrow emission, with near unit photoluminescence quantum yields of up to 97.5%. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy confirm the formation of SiO2 through the hydrolysis of APTES on the CsPbI3 PeQDs surface. Furthermore, they have a significantly improved stability against storage, heat, and ethanol. By combining purple-emission GaN light-emitting diodes, the SiO2-CsPbI3 PeQDs were successfully employed as down-conversion emitters and exhibited considerable enhanced luminous performance and excellent stability, demonstrating their promising future in the practical application of solid-state lighting fields.
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| 10. |
- Ruan, Ting, et al.
(författare)
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Identification and composition of emerging quaternary ammonium compounds in municipal sewage sludge in China
- 2014
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 48:8, s. 4289-4297
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Tidskriftsartikel (refereegranskat)abstract
- Quaternary ammonium compounds (QACs) have raised considerable attention due to their wide commercial applications and recent discovery of unknown persistent analogues in aqueous environment. In this work, the occurrence and distribution of alkyltrimethylammonium (ATMAC), benzylakyldimethylethylammonium (BAC) and dialkyldimethylammonium (DADMAC) homologues were investigated in fifty-two municipal sewage sludge samples. ATMAC C10-18, BAC C8-18 and paired DADMAC C8:8-C18:18 as well as emerging homologues such as ATMAC-20, 22 and mixed DADMAC-16:18 and 14:16 were present. Furthermore, paired DADMAC-20:20 and mixed DADMAC-14:18, 18:20 were identified for the first time by nontarget qualitative strategies. A triple quadruple mass spectrometer quantification method was also initially verified with the aid of laboratory synthesized standards for the analysis of the mixed DADMACs with no certificated commercial standards currently available. The total concentrations of ATMACs, BACs and DADMACs were in the range of 0.38-293, 0.09-191 and 0.64-344 μg/g dry weight, respectively, and particularly, mixed DADMACs constituted 39 ± 7% of total DADMAC concentrations. The concentrations and profiles of individual homologues further suggested different QAC applications and fate in China. Significant correlations were also found among the concentrations of various QAC homologues as well as wastewater treatment plant (WWTP) characteristics (total organic carbon contents and daily treatment volumes).
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