| 401. |
- Wang, Yu-Cheng, et al.
(författare)
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Porous Carbon Membrane-Supported Atomically Dispersed Pyrrole-Type Fe-N-4 as Active Sites for Electrochemical Hydrazine Oxidation Reaction
- 2020
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Ingår i: Small. - : Wiley. - 1613-6810 .- 1613-6829. ; 16:31
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Tidskriftsartikel (refereegranskat)abstract
- The rational design of catalytically active sites in porous materials is essential in electrocatalysis. Herein, atomically dispersed Fe-N-x sites supported by hierarchically porous carbon membranes are designed to electrocatalyze the hydrazine oxidation reaction (HzOR), one of the key techniques in electrochemical nitrogen transformation. The high intrinsic catalytic activity of the Fe-N-x single-atom catalyst together with the uniquely mixed micro-/macroporous membrane support positions such an electrode among the best-known heteroatom-based carbon anodes for hydrazine fuel cells. Combined with advanced characterization techniques, electrochemical probe experiments, and density functional theory calculation, the pyrrole-type Fe-N-4 structure is identified as the real catalytic site in HzOR.
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| 402. |
- Wu, Yuan, et al.
(författare)
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A Comparison of Functional Features in Chinese and US Mobile Apps for Diabetes Self-Management : A Systematic Search in App Stores and Content Analysis
- 2019
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Ingår i: JMIR mhealth and uhealth. - : JMIR PUBLICATIONS, INC. - 2291-5222. ; 7:8
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Tidskriftsartikel (refereegranskat)abstract
- Background: Mobile health interventions are widely used for self-management of diabetes, which is one of the most burdensome noncommunicable chronic diseases worldwide. However, little is known about the distribution of characteristics and functions of in-store mobile apps for diabetes. Objective: This study aimed to investigate the distribution of characteristics and functions of the in-store mobile apps for self-management of diabetes in the United States and China using a predefined functional taxonomy, which was developed and published in our previous study. Methods: We identified apps by searching diabetes in English or Chinese in the Apple iTunes Store and Android Markets (both in the United States and China) and included apps for diabetes self-management. We examined the validity and reliability of the predefined functional taxonomy with 3 dimensions: clinical module, functional module, and potential risk. We then classified all functions in the included apps according to the predefined taxonomy and compared the differences in the features of these apps between the United States and China. Results: We included 171 mobile diabetes apps, with 133 from the United States and 38 from China. Apps from both countries faced the challenges of evidence-based information, proper risk assessment, and declaration, especially Chinese apps. More Chinese apps provide app-based communication functions (general communication: Chinese vs US apps, 39%, 15/38 vs 18.0%, 24/133; P=.006 and patient-clinician communication: Chinese vs US apps, 68%, 26/38 vs 6.0%, 8/133; P<.001), whereas more US apps provide the decision-making module (Chinese vs US apps, 0%, 0/38 vs 23.3%, 31/133; P=.001), which is a high-risk module. Both complication prevention (Chinese vs US apps, 8%, 3/38 vs 3.8%, 5/133; P=.50) and psychological care (Chinese vs US apps, 0%, 0/38 vs 0.8%, 1/133; P>.99) are neglected by the 2 countries. Conclusions: The distribution of characteristics and functions of in-store mobile apps for diabetes self-management in the United States was different from China. The design of in-store diabetes apps needs to be monitored closely.
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| 403. |
- Wu, Ya-ting, et al.
(författare)
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Selective and simultaneous determination of trace bisphenol A and tebuconazole in vegetable and juice samples by membrane-based molecularly imprinted solid-phase extraction and HPLC
- 2014
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Ingår i: Food Chemistry. - : Elsevier BV. - 1873-7072 .- 0308-8146. ; 164, s. 527-535
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Tidskriftsartikel (refereegranskat)abstract
- Nanofibrous molecularly imprinted membranes (nano-MIMs) with multi-analyte selectivity were prepared by encapsulating two types of molecularly imprinted polymer nanoparticles (MIP-NPs) into electrospun polyvinyl alcohol nanofibers. The obtained nano-MIMs maintained high molecular selectivity offered by each of the MIP-NPs. Nano-MIM embedding BPA-imprinted nanoparticles and TBZ-imprinted nanoparticles together showed the highest binding selectivity for acid bisphenol A (BPA) and basic tebuconazole (TBZ). This nano-MIM was used as affinity material of membrane-based molecularly imprinted solid-phase extraction (m-MISPE) to extract trace BPA and TBZ in vegetables and juices simultaneously. The recoveries of BPA and TBZ from different samples were higher than 70.33% with RSDs lower than 9.57%. m-MISPE gave better HPLC separation efficiencies and higher recoveries than conventional SPE based on C18/SCX. Multi-analyte selective m-MISPE combined with HPLC realized selective and simultaneous determination of several trace analytes with opposite charges/polarities in different food samples. (C) 2014 Elsevier Ltd. All rights reserved.
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| 404. |
- Xu, Dingfeng, et al.
(författare)
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Surface Charges Control the Structure and Properties of Layered Nanocomposite of Cellulose Nanofibrils and Clay Platelets
- 2021
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 13:3, s. 4463-4472
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Tidskriftsartikel (refereegranskat)abstract
- The interfacial bonding and structure at the nanoscale in the polymer-clay nanocomposites are essential for obtaining desirable material and structure properties. Layered nanocomposite films of cellulose nanofibrils (CNFs)/montmorillonite (MTM) were prepared from the water suspensions of either CNFs bearing quaternary ammonium cations (Q-CNF) or CNFs bearing carboxylate groups (TO-CNF) with MTM nanoplatelets carrying net surface negative charges by using vacuum filtration followed by compressive drying. The effect of the ionic interaction between cationic or anionic charged CNFs and MTM nanoplatelets on the structure, mechanical properties, and flame retardant performance of the TO-CNF/MTM and Q-CNF/MTM nanocomposite films were studied and compared. The MTM nanoplatelets were well dispersed in the network of TO-CNFs in the form of nanoscale tactoids with the MTM content in the range of 5-70 wt %, while an intercalated structure was observed in the Q-CNF/MTM nanocomposites. The resulting TO-CNF/MTM nanocomposite films had a better flame retardant performance as compared to the QCNF/MTM films with the same MTM content. In addition, the effective modulus of MTM for the TO-CNF/MTM nanocomposites was as high as 129.9 GPa, 3.5 times higher than that for Q-CNF/MTM (37.1 GPa). On the other hand, the Q-CNF/MTM nanocomposites showed a synergistic enhancement in the modulus and tensile strength together with strain-to-failure and demonstrated a much better toughness as compared to the TO-CNF/MTM nanocomposites.
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| 405. |
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| 406. |
- Xu, Luohao, et al.
(författare)
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Dynamic evolutionary history and gene content of sex chromosomes across diverse songbirds
- 2019
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Ingår i: Nature Ecology & Evolution. - : NATURE PUBLISHING GROUP. - 2397-334X. ; 3:5, s. 834-844
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Tidskriftsartikel (refereegranskat)abstract
- Songbirds have a species number close to that of mammals and are classic models for studying speciation and sexual selection. Sex chromosomes are hotspots of both processes, yet their evolutionary history in songbirds remains unclear. We characterized genomes of 11 songbird species, with 5 genomes of bird-of-paradise species. We conclude that songbird sex chromosomes have undergone four periods of recombination suppression before species radiation, producing a gradient of pairwise sequence divergence termed ‘evolutionary strata’. The latest stratum was probably due to a songbird-specific burst of retrotransposon CR1-E1 elements at its boundary, instead of the chromosome inversion generally assumed for suppressing sex-linked recombination. The formation of evolutionary strata has reshaped the genomic architecture of both sex chromosomes. We find stepwise variations of Z-linked inversions, repeat and guanine-cytosine (GC) contents, as well as W-linked gene loss rate associated with the age of strata. A few W-linked genes have been preserved for their essential functions, indicated by higher and broader expression of lizard orthologues compared with those of other sex-linked genes. We also find a different degree of accelerated evolution of Z-linked genes versus autosomal genes among species, potentially reflecting diversified intensity of sexual selection. Our results uncover the dynamic evolutionary history of songbird sex chromosomes and provide insights into the mechanisms of recombination suppression.
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| 407. |
- Xu, Luohao, et al.
(författare)
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Sequence Transpositions Restore Genes on the HighlyDegenerated W Chromosomes of Songbirds
- 2020
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Ingår i: Genes. - 2073-4425. ; 11
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Tidskriftsartikel (refereegranskat)abstract
- The female-specific W chromosomes of most Neognathae birds are highly degenerated and gene-poor. Previous studies have demonstrated that the gene repertoires of the Neognathae bird W chromosomes, despite being in small numbers, are conserved across bird species, likely due to purifying selection maintaining the regulatory and dosage-sensitive genes. Here we report the discovery of DNA-based sequence duplications from the Z to the W chromosome in birds-of-paradise (Paradisaeidae, Passeriformes), through sequence transposition. The original transposition involved nine genes, but only two of them (ANXA1 and ALDH1A1) survived on the W chromosomes. Both ANXA1 and ALDH1A1 are predicted to be dosage-sensitive, and the expression of ANXA1 is restricted to ovaries in all the investigated birds. These analyses suggest the newly transposed gene onto the W chromosomes can be favored for their role in restoring dosage imbalance or through female-specific selection. After examining seven additional songbird genomes, we further identified five other transposed genes on the W chromosomes of Darwin’s finches and one in the great tit, expanding the observation of the Z-to-W transpositions to a larger range of bird species, but not all transposed genes exhibit dosage-sensitivity or ovary-biased expression We demonstrate a new mechanism by which the highly degenerated W chromosomes of songbirds can acquire genes from the homologous Z chromosomes, but further functional investigations are needed to validate the evolutionary forces underlying the transpositions
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| 408. |
- Yan, Hong, et al.
(författare)
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Perfluoroalkyl acids in municipal landfill leachates from China : Occurrence, fate during leachate treatment and potential impact on groundwater
- 2015
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 524, s. 23-31
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Tidskriftsartikel (refereegranskat)abstract
- Raw and treated landfill leachate samples were collected from 5 municipal landfill sites in China to measure the concentrations and contamination profile of perfluoroalkyl acids (PFAAs) in leachate during different steps of treatment. The total concentration of PFAAs (Sigma PFAAs) ranged from 7280 to 292,000 ng L-1 in raw leachate and from 98.4 to 282,000 ng L-1 in treated leachate. The dominant compounds measured were PFOA (mean contribution 28.8% and 36.8% in raw and treated leachate, respectively) and PFBS (26.1% and 40.8% in raw and treated leachate, respectively). A calculation of mass flows during the leachate treatment processes showed that the fate of individual PFAAs was substance and treatment-specific. The Chinese national leakage of Sigma PFAAs to groundwater from landfill leachate was estimated to be 3110 kg year(-1), which is a significant environmental release that is potentially threatening the sustainable use of groundwater as a drinking water source.
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| 409. |
- Yang, Liting, et al.
(författare)
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Ligand-Directed Conformational Control over Porphyrinic Zirconium Metal-Organic Frameworks for Size-Selective Catalysis
- 2021
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 143:31, s. 12129-12137
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Tidskriftsartikel (refereegranskat)abstract
- Zirconium-based metal-organic frameworks (Zr-MOFs) have aroused enormous interest owing to their superior stability, flexible structures, and intriguing functions. Precise control over their crystalline structures, including topological structures, porosity, composition, and conformation, constitutes an important challenge to realize the tailor-made functionalization. In this work, we developed a new Zr-MOF (PCN-625) with a csq topological net, which is similar to that of the well-known PCN-222 and NU-1000. However, the significant difference lies in the conformation of porphyrin rings, which are vertical to the pore surfaces rather than in parallel. The resulting PCN-625 exhibits two types of one-dimensional channels with concrete diameters of 2.03 and 0.43 nm. Furthermore, the vertical porphyrins together with shrunken pore sizes could limit the accessibility of substrates to active centers in the framework. On the basis of the structural characteristics, PCN-625(Fe) can be utilized as an efficient heterogeneous catalyst for the size-selective [4 + 2] hetero-Diels-Alder cycloaddition reaction. Due to its high chemical stability, this catalyst can be repeatedly used over six times. This work demonstrates that Zr-MOFs can serve as tailor-made scaffolds with enhanced flexibility for target-oriented functions.
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| 410. |
- Yang, Lingling, et al.
(författare)
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Substance P promotes diabetic corneal epithelial wound healing through molecular mechanisms mediated via the neurokinin-1 receptor.
- 2014
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Ingår i: Diabetes. - : American Diabetes Association. - 0012-1797 .- 1939-327X. ; 63:12, s. 4262-4274
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Tidskriftsartikel (refereegranskat)abstract
- Substance P (SP) is a neuropeptide, predominantly released from sensory nerve fibers, with a potentially protective role in diabetic corneal epithelial wound healing. However, the molecular mechanism remains unclear. We investigated the protective mechanism of SP against hyperglycemia-induced corneal epithelial wound healing defects, using type 1 diabetic mice and high glucose-treated corneal epithelial cells. Hyperglycemia induced delayed corneal epithelial wound healing, accompanied with attenuated corneal sensation, mitochondrial dysfunction, and impairments of Akt-, EGFR-, and Sirt1-activation, as well as decreased reactive oxygen species (ROS) scavenging capacity. However, SP application promoted the epithelial wound healing, the recovery of corneal sensation, the improvement of mitochondrial function, and the reactivation of Akt, EGFR and Sirt1, as well as increased ROS scavenging capacity, in both diabetic mouse corneal epithelium and high glucose-treated corneal epithelial cells. The promotion of SP on diabetic corneal epithelial healing was completely abolished by a NK-1 receptor antagonist. Moreover, the subconjunctival injection of NK-1 receptor antagonist also caused diabetic corneal pathological changes in normal mice. In conclusion, the results suggest that SP-NK-1 receptor signaling plays a critical role in the maintenance of corneal epithelium homeostasis, and that SP signaling through the NK-1 recssssseptor contributes to the promotion of diabetic corneal epithelial wound healing by rescued activation of Akt, EGFR, and Sirt1, improvement of mitochondrial function, and increased ROS scavenging capacity.
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