| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- Du, Hao, et al.
(författare)
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Side reactions/changes in lithium-ion batteries : mechanisms and strategies for creating safer and better batteries
- 2024
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Ingår i: Advanced Materials. - : John Wiley & Sons. - 0935-9648 .- 1521-4095.
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Forskningsöversikt (refereegranskat)abstract
- Abstract Lithium-ion batteries (LIBs), in which lithium ions function as charge carriers, are considered the most competitive energy storage devices due to their high energy and power density. However, battery materials, especially with high capacity undergo side reactions and changes that result in capacity decay and safety issues. A deep understanding of the reactions that cause changes in the battery's internal components and the mechanisms of those reactions is needed to build safer and better batteries. This review focuses on the processes of battery failures, with voltage and temperature as the underlying factors. Voltage-induced failures result from anode interfacial reactions, current collector corrosion, cathode interfacial reactions, overcharge, and overdischarge, while temperature-induced failure mechanisms include SEI decomposition, separator damage, and interfacial reactions between electrodes and electrolytes. The review also presents protective strategies for controlling these reactions. As a result, the reader is offered a comprehensive overview of the safety features and failure mechanisms of various LIB components.
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| 5. |
- Du, Shuhui, et al.
(författare)
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Multilocus analysis of nucleotide variation and speciation in three closely related Populus (Salicaceae) species
- 2015
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Ingår i: Molecular Ecology. - : Wiley. - 0962-1083 .- 1365-294X. ; 24:19, s. 4994-5005
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Tidskriftsartikel (refereegranskat)abstract
- Historical tectonism and climate oscillations can isolate and contract the geographical distributions of many plant species, and they are even known to trigger species divergence and ultimately speciation. Here, we estimated the nucleotide variation and speciation in three closely related Populus species, Populus tremuloides, P.tremula and P.davidiana, distributed in North America and Eurasia. We analysed the sequence variation in six single-copy nuclear loci and three chloroplast (cpDNA) fragments in 497 individuals sampled from 33 populations of these three species across their geographic distributions. These three Populus species harboured relatively high levels of nucleotide diversity and showed high levels of nucleotide differentiation. Phylogenetic analysis revealed that P.tremuloides diverged earlier than the other two species. The cpDNA haplotype network result clearly illustrated the dispersal route from North America to eastern Asia and then into Europe. Molecular dating results confirmed that the divergence of these three species coincided with the sundering of the Bering land bridge in the late Miocene and a rapid uplift of the Qinghai-Tibetan Plateau around the Miocene/Pliocene boundary. Vicariance-driven successful allopatric speciation resulting from historical tectonism and climate oscillations most likely played roles inthe formation of the disjunct distributions and divergence of these three Populus species.
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| 6. |
- Li, Yingming, et al.
(författare)
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Levels and vertical distributions of PCBs, PBDEs, and OCPs in the atmospheric boundary layer : observation from the Beijing 325-m meteorological tower
- 2009
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 43:4, s. 1030-1035
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Tidskriftsartikel (refereegranskat)abstract
- Polyurethane foam disk passive air sampling was carried out to investigate the levels, vertical distributions, and potential sources of polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs) in the atmospheric boundary layer of an urban site in Asia. Sampling was performed at nine heights (15, 47, 80, 120, 160, 200, 240, 280, 320 m) of the 325-m meteorological tower in Beijing, China over three 2-month periods between December 2006 and August 2007. This is the first study to report vertical variations of PBDEs in the ABL and one of only a few studies to investigate vertical distributions of persistent organic pollutants. The levels of sigma19PCBs and sigma8PBDEs were relatively low, ranging from 22 to 65 and from 2.3 to 18 pg m-3, respectively. Air concentrations of gamma-HCH were high, with values in the range of 39-103 pg m-3 in winter, 100-180 pg m-3 in spring, and 115-242 pg m-3 in summer, respectively. alpha-HCH concentrations ranged from 20 to 86 pg m-3, p,p'-DDT between 7.3 and 78 pg m-3, and HCB between 15 and 160 pg m-3. The seasonal variations of PCBs, PBDEs, and OCPs may reflect different sources for these chemicals, such as those related with regional use (gamma-HCH), volatilization/re-emission (PBDEs, PCBs, alpha-HCH), and pesticide impurities (HCB). Although the performance reference compounds (PRCs) were spiked before deployment, the sampling rates showed strong dependency on wind speeds, resulting in large variations in uptake rates in the ABL, ranging from approximately 7.0 m3 day-1 at ground level to 11 m3 day-1 at 320 m. Levels of PCBs, PBDEs, and OCPs decreased with increasing ABL height indicating the potential of Beijing as the local sources.
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| 7. |
- Liang, Yongqi, et al.
(författare)
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Achieving High Open-Circuit Voltages up to 1.57 V in Hole-Transport-Material-Free MAPbBr(3) Solar Cells with Carbon Electrodes
- 2018
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Ingår i: Advanced Energy Materials. - : Wiley-VCH Verlagsgesellschaft. - 1614-6832 .- 1614-6840. ; 8:4
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Tidskriftsartikel (refereegranskat)abstract
- An open-circuit voltage (V-oc) of 1.57 V under simulated AM1.5 sunlight in planar MAPbBr(3) solar cells with carbon (graphite) electrodes is obtained. The hole-transport-material-free MAPbBr(3) solar cells with the normal architecture (FTO/TiO2/MAPbBr(3)/carbon) show little hysteresis during current-voltage sweep under simulated AM1.5 sunlight. A solar-to-electricity power conversion efficiency of 8.70% is achieved with the champion device. Accordingly, it is proposed that the carbon electrodes are effective to extract photogenerated holes in MAPbBr(3) solar cells, and the industry-applicable carbon electrodes will not limit the performance of bromide-based perovskite solar cells. Based on the analysis of the band alignment, it is found that the voltage (energy) loss across the interface between MAPbBr(3) and carbon is very small compared to the offset between the valence band maximum of MAPbBr(3) and the work function of graphite. This finding implies either Fermi level pinning or highly doped region inside MAPbBr(3) layer exists. The band-edge electroluminescence spectra of MAPbBr(3) from the solar cells further support no back-transfer pathways of electrons across the MAPbBr(3)/TiO2 interface.
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| 8. |
- Cai, Shangming, et al.
(författare)
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DynaComm: Accelerating Distributed CNN Training between Edges and Clouds through Dynamic Communication Scheduling
- 2022
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Ingår i: IEEE Journal on Selected Areas in Communications. - : IEEE. - 0733-8716 .- 1558-0008. ; 40:2, s. 611-625
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Tidskriftsartikel (refereegranskat)abstract
- To reduce uploading bandwidth and address privacy concerns, deep learning at the network edge has been an emerging topic. Typically, edge devices collaboratively train a shared model using real-time generated data through the Parameter Server framework. Although all the edge devices can share the computing workloads, the distributed training processes over edge networks are still time-consuming due to the parameters and gradients transmission procedures between parameter servers and edge devices. Focusing on accelerating distributed Convolutional Neural Networks (CNNs) training at the network edge, we present DynaComm, a novel scheduler that dynamically decomposes each transmission procedure into several segments to achieve optimal layer-wise communications and computations overlapping during run-time. Through experiments, we verify that DynaComm manages to achieve optimal layer-wise scheduling for all cases compared to competing strategies while the model accuracy remains untouched.
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| 9. |
- Chen, Tao, et al.
(författare)
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SinoPedia—A Linked Data Services platform for decentralized knowledge base
- 2019
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Ingår i: PLoS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 14:8
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge bases are largely developed and utilized in academic and industrial fields, such as DBPedia, VIAF, LoC, Getty, and which are published in the Linked Data format. However, if you want to view different resources on these knowledge bases, you have to switch between different web pages from these resources. Therefore, we proposed a decentralized data hub named SinoPedia, which consists of several linked data services and can re-publish these RDF data in one platform. Firstly, these different Linked Data services include: Linked Data Transformation Service (LDTS), Linked Data Query Service (LDQS), Linked Data Publishing Service (LDPS) and Linked Data Knowledge Service (LDKS). The resource URI is the basis and core of the linked data, thus we will focus on the resource forwarding mechanism in LDPS service which can rewrite resource URI using a global and standard format among knowledge bases. Some knowledge bases were configured in SinoPedia platform in this paper. In addition to the above services, Linked Data Reasoning Service (LDRS) and Linked Data Intelligence Service (LDIS) will be added to the platform in the future. In short, all of these Linked Data Services will form the core framework in order to providing a good linked data application ecosystem.
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| 10. |
- Huang, Shirong, et al.
(författare)
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Infrared Emissivity Measurement for Vertically Aligned Multiwall Carbon Nanotubes (CNTs) Based Heat Spreader Applied in High Power Electronics Packaging
- 2016
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Ingår i: 6th Electronic System-integration Technology Conference (ESTC 2016). - 9781509014026 ; , s. Article no 7764696-
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Konferensbidrag (refereegranskat)abstract
- Vertically-aligned multiwall carbon nanotubes were deposited on silicon substrate by low pressure chemical vapor deposition (LPCVD), which can be utilized as heat spreaders in high power electronic packaging due to their remarkable thermal conductivity. The infrared emissivity of the vertically aligned multiwall carbon nanotubes was then characterized based on the FLIR SC600 infrared imaging system. The average infrared emissivity of the multiwall carbon nanotubes sample was about 0.92, which agrees well with experimental results reported before. Scanning electron microscopy (SEM) images of the multiwall carbon nanotubes were further analyzed to explain its high emissivity, and the reason can be attributed to the homogeneous sparseness and aligned structure of the vertically aligned multiwall carbon nanotubes
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| 11. |
- Huang, Shirong, et al.
(författare)
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The Effects of Graphene-Based Films as Heat Spreaders for Thermal Management in Electronic Packaging
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016. - 9781509013968 ; , s. Art no 7583272; Pages 889-892
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Konferensbidrag (refereegranskat)abstract
- Graphene-based films (GBF) were fabricated using a chemical conversion process including graphene oxide (GO) preparation by use of Hummer’s method, graphene oxide reduction using L-ascorbic acid (LAA), and finally film formation by vacuum filtration. GBF is considered as a candidate material for thermal management, i.e. for removing heat from hotspots in power electronic packaging, due to its high thermal conductivity. In this work, the GBF heat spreading performance in 3D TSV packaging was analysed using finite element methods (FEM) implemented in the COMSOL software. Both size effects and the influence of the thermal conductivity of the GBF heat spreader on the thermal performance of the 3D TSV package were evaluated. Furthermore, the size effects of the thermal conductive adhesive (TCA) underfill between the chip and the printed circuit board (PCB) were analysed. The results obtained are critical for proper design of graphene-based lateral heat spreaders in high power electronic packaging.
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| 12. |
- Li, Qinghu, et al.
(författare)
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Retroperitoneal packing or angioembolization for haemorrhage control of pelvic fractures-Quasi-randomized clinical trial of 56 haemodynamically unstable patients with Injury Severity Score ≥33
- 2016
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Ingår i: Injury. - : Elsevier BV. - 0020-1383 .- 1879-0267. ; 47:2, s. 395-401
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: Both retroperitoneal pelvic packing and primary angioembolization are widely used to control haemorrhage related to pelvic fractures. It is still unknown which protocol is the safest. The primary aim of this study is to compare survival and complications of pelvic packing and angioembolization in massive haemorrhage related to pelvic fractures.METHODS: Patients with haemodynamically unstable pelvic fractures were quasi-randomized to either pelvic packing (PACK) or angiography (ANGIO) using the time of admission as separator. Physiological markers of haemorrhage, time to intervention, procedure/surgical time, transfusion requirements, complications and early mortality were recorded and analyzed.RESULTS: 29 patients were randomized to PACK and 27 patients to ANGIO. The Injury Severity Score (ISS) in the ANGIO group was lower than in the PACK group (43±7 vs 48±6) (p<0.01). The median time from admission to angiography for the ANGIO group was 102min (range 76-214), and longer than 77min (range 43-125) from admission to surgery for the PACK group (p<0.01). The procedure time for the ANGIO group was 84min (range 62-105); while the surgical time was 60min (range 41-92) for the PACK group (p<0.001). The ANGIO group received 6.4 units packed red blood cells (range 4-10) in the first 24h after angiography. The PACK group required 5.2 units (range 3-10) in the first 24h after leaving the operating theatre (p=0.124). 9 patients in the ANGIO group underwent pelvic packing for persistent bleeding. 6 patients in the PACK group required pelvic angiography after pelvic packing for ongoing hypotension following packing (p=0.353). 5 patients in the ANGIO group died (2 from exsanguination), while 4 in the PACK group died (none from exsanguination) (p=0.449). Complications occurred without differences in both groups.CONCLUSIONS: Compared with angioembolization, pelvic packing has shorter time to intervention and surgical time. Thus pelvic packing is the more rapid treatment of severe pelvic trauma than pelvic angioembolization. It is suitable for patients with haemodynamic instability at centers where the interventional radiology staff is not in-house at all times.REGISTRATION: ClinicalTrials.gov (NCT02535624) and ISRCTN registry (ISRCTN91713422).
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| 13. |
- Wang, Dongsheng, et al.
(författare)
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Publishing E-RDF linked data for many agents by single third-party server
- 2017
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Ingår i: Semantic Technology - 7th Joint International Conference, JIST 2017, Proceedings. - Cham : Springer International Publishing. - 1611-3349 .- 0302-9743. - 9783319706818 ; 10675 LNCS, s. 151-163
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Konferensbidrag (refereegranskat)abstract
- Linked data is one of the most successful practices in semantic web, which has led to the opening and interlinking of data. Though many agents (mostly academic organizations and government) have published a large amount of linked data, numerous agents such as private companies and industries either do not have the ability or do not want to make an additional effort to publish linked data. Thus, for agents who are willing to open part of their data but do not want to make an effort, the task can be undertaken by a professional third-party server (together with professional experts) that publishes linked data for these agents. Consequently, when a single third-party server is on behalf of multiple agents, it is also responsible to organize these multiple-source URIs (data) in a systematic way to make them referable, satisfying the 4-star data principles, as well as protect the confidential data of these agents. In this paper, we propose a framework to leverage these challenges and design a URI standard based on our proposed E-RDF, which extends and optimizes the existing 5-star linked data principles. Also, we introduce a customized data filtering mechanism to protect the confidential data. For validation, we implement a prototype system as a third-party server that publishes linked data for a number of agents. It demonstrates well-organized 5-star linked data plus E-RDF and shows the additional advantages of data integration and interlinking among agents.
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| 14. |
- Wang, Fei, et al.
(författare)
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Endothelial cell heterogeneity and microglia regulons revealed by a pig cell landscape at single-cell level
- 2022
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Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
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Tidskriftsartikel (refereegranskat)abstract
- Pigs are valuable large animal models for biomedical and genetic research, but insights into the tissue- and cell-type-specific transcriptome and heterogeneity remain limited. By leveraging single-cell RNA sequencing, we generate a multiple-organ single-cell transcriptomic map containing over 200,000 pig cells from 20 tissues/organs. We comprehensively characterize the heterogeneity of cells in tissues and identify 234 cell clusters, representing 58 major cell types. In-depth integrative analysis of endothelial cells reveals a high degree of heterogeneity. We identify several functionally distinct endothelial cell phenotypes, including an endothelial to mesenchymal transition subtype in adipose tissues. Intercellular communication analysis predicts tissue- and cell type-specific crosstalk between endothelial cells and other cell types through the VEGF, PDGF, TGF-beta, and BMP pathways. Regulon analysis of single-cell transcriptome of microglia in pig and 12 other species further identifies MEF2C as an evolutionally conserved regulon in the microglia. Our work describes the landscape of single-cell transcriptomes within diverse pig organs and identifies the heterogeneity of endothelial cells and evolutionally conserved regulon in microglia.
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| 15. |
- Zhu, Zhenlong, et al.
(författare)
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PINCH expression and its significance in esophageal squamous cell carcinoma
- 2008
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Ingår i: Disease Markers. - : Hindawi Limited. - 0278-0240 .- 1875-8630. ; 25:2, s. 75-80
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Tidskriftsartikel (refereegranskat)abstract
- Particularly interesting new cysteine-histidine rich protein (PINCH), as a newly discovered protein of LIM family members, may play a role in signal transduction of integrin and growth factor, and involved in the incidence and development of tumors. PINCH protein is overexpressed in tumor-associated stroma of several types of tumors. However, there is no study of the PINCH in esophageal cancer, therefore we investigated PINCH expression in esophageal squamous cell carcinomas and its clinicopathogical significance in the patients. PINCH expression was immunohistochemically examined in 20 normal esophageal samples and 64 esophageal squamous cell carcinomas. The results showed that PINCH expression in the stroma of cancers was heterogeneous, and its positive rate (56%) was higher than that of normal esophageal mucosa (5%, p<0.0001). The stronger staining was observed at the invasive edge of tumor when compared to the inner area of tumor. The rate of positive PINCH (90%) in the cases with lymph node metastasis was higher than that (41%) in the cases without metastasis (p<0.0001). PINCH expression was not correlated with patients’ gender, age, tumor location, size and differentiation (p>0.05). The results suggest that PINCH protein may be a marker of tumor associated-stroma involving tumor development, and predicting the ability of invasion and metastasis of esophageal squamous cell carcinoma.
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| 16. |
- Fu, Xianbiao, et al.
(författare)
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High-Entropy Alloy Nanosheets for Fine-Tuning Hydrogen Evolution
- 2022
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Ingår i: ACS Catalysis. - : American Chemical Society (ACS). - 2155-5435. ; 12:19, s. 11955-11959
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Tidskriftsartikel (refereegranskat)abstract
- The electrolysis of water is promising for hydrogen production. The development of high-performance and low-cost hydrogen evolution reaction (HER) electrocatalysts is particularly important for the wide application of water electrolyzers. Tuning the hydrogen binding energy (HBE) of materials is an effective way to optimize the HER electrocatalysts, particularly for applications in an acidic environment. Here, we report the discovery of a Pt-free combination, PdMoGaInNi, which has the HBE optimum, via computer-facilitated screening. As the exploratory example of the two-dimensional high-entropy alloy (HEA) for HER, the PdMoGaInNi HEA nanosheets were synthesized to realize the predicted Pt-free combination with optimal HBE. The PdMoGaInNi HEA nanosheets exhibit a high HER activity with low overpotentials of 13 mV at 10 mA cm-2, outperforming commercial Pd/C and Pt/C catalysts. Given the high entropy, lattice distortion, and sluggish diffusion effects of HEA, the PdMoGaInNi shows great long-term durability for at least 200 h in a proton exchange membrane water electrolyzer.
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| 17. |
- Shi, Wenbin, et al.
(författare)
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Redox-responsive polymeric membranes via supermolecular host-guest interactions
- 2015
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Ingår i: Journal of Membrane Science. - : Elsevier BV. - 0376-7388 .- 1873-3123. ; 480, s. 139-152
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Tidskriftsartikel (refereegranskat)abstract
- Redox-responsive materials have attracted much attention, and redox-responsive membrane is strongly desired since enormous numbers of redox reactions carry out in living systems. Herein, a novel polymeric membrane with redox-resposive hydraulic permeability is fabricated by introducing a reversible redox-responsive system based on the host guest complex between ferrocene (Fc) and beta-cyclodextrin (1 CD) into polyethersulfone (PES) membrane. As the result of reversible radox-responsive formation or deformation of the complex, the water flux for the membrane with 18.3 wt% redox-responsive materials was 270 mL/m(2) mmHg h in original state, while increased to 1022 mL/m(2) mmHg h in oxidation state and decreased to 538 mL/m(2) mmHg h in reduction state. In addition, the results of water contact angle, surface zeta potential and the gas flow/liquid displacement confirmed that the origin of the reclox-responsive hydraulic permeability were the change of the pore size and porosity for the modified membranes. The redox-responsive membranes have great potential to be utilized in the Fields of chemical detection, drug delivery, biological treatments and so On.
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| 18. |
- Wang, Yajuan, et al.
(författare)
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Pushing the Envelope : Achieving an Open-Circuit Voltage of 1.18 V for Unalloyed MAPbI(3) Perovskite Solar Cells of a Planar Architecture
- 2018
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Ingår i: Advanced Functional Materials. - : Wiley-VCH Verlagsgesellschaft. - 1616-301X .- 1616-3028. ; 28:30
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Tidskriftsartikel (refereegranskat)abstract
- After an overwhelmingly fast increase during the period from 2009 to 2016, the power conversion efficiency of hybrid perovskite solar cells levels at approximate to 22% during the past two years. Every small advance to theoretical limits of the photovoltaic metrics will significantly deepen the understanding of internal processes inside the perovskite solar cells. Here, by introducing chloroform as the antisolvent, the one-step deposition method to fabricate methylammonium lead tri-iodide (MAPbI(3)) perovskite films under ambient air condition is optimized. With MAPbI(3) solar cells of a planar architecture, a record high V-oc of 1.18 V is obtained under simulated AM1.5 sunlight. The achievement helps pure MAPbI(3) to reestablish its potential as a model compound for research in hybrid perovskite solar cells. After systematic comparison on different electron transport layers (SnO2 and TiO2) and fluorine doped tin oxide (FTO) substrates of different roughness for photon trapping inside MAPbI(3) solar cells, the remaining 0.14 V V-oc loss is elucidated to be due to the poor luminescent property of the MAPbI(3) films.
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| 19. |
- Yang, Xiaofang, et al.
(författare)
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Application of ATR-FTIR spectroscopy in the study of adsorption on environmental micro-interfaces
- 2010
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Ingår i: Huaxue jinzhan. - 1005-281X. ; 22:6, s. 1185-1194
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Tidskriftsartikel (refereegranskat)abstract
- Interfacial adsorption process is the initial step or key step for most of environmental micro-interface reactions. The online study of environmental micro-interfacial adsorption by in situ research methods provides direct information about interface reactions and reliable evidence for the detection of reaction mechanisms which are of great importance to understand the rule of transformation and distribution of pollutants in the environment. Because of its unique sampling principle, convenient sample pre-treatment and wide applicability, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) is becoming a powerful tool for investigating the interface reactions. Based on a brief introduction of the working principle of ATR-FTIR, the application of this technique in the investigation of adsorption on environmental interfaces, especially mineral-water interfaces, is summarized. Furthermore, the perspective of this method is discussed as well.
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| 20. |
- Yang, Xiaofang, et al.
(författare)
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Effect of phosphate on heterogeneous Fenton oxidation of catechol by nano-Fe3O4 : Inhibitor or stabilizer?
- 2016
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Ingår i: Journal of Environmental Sciences(China). - : Elsevier BV. - 1001-0742 .- 1878-7320. ; 39, s. 69-76
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Tidskriftsartikel (refereegranskat)abstract
- The effect of phosphate on adsorption and oxidation of catechol, 1,2-dihydroxybenzene, in a heterogeneous Fenton system was investigated. In situ attenuated total reflectance infrared spectroscopy (ATR-FTIR) was used to monitor the surface speciation at the nano-Fe3O4 catalyst surface. The presence of phosphate decreased the removal rate of catechol and the abatement of dissolved organic compounds, as well as the decomposition of H2O2. This effect of phosphate was mainly due to its strong reaction with surface sites on the iron oxide catalyst. At neutral and acid pH, phosphate could displace the adsorbed catechol from the surface of catalyst and also could compete for surface sites with H2O2. In situ IR spectra indicated the formation of iron phosphate precipitation at the catalyst surface. The iron phosphate surface species may affect the amount of iron atoms taking part in the catalytic decomposition of H2O2 and formation of hydroxyl radicals, and inhibit the catalytic ability of Fe3O4 catalyst. Therefore, phosphate ions worked as stabilizer and inhibitor in a heterogeneous Fenton reaction at the same time, in effect leading to an increase in oxidation efficiency in this study. However, before use of phosphate as pH buffer or H2O2 stabilizer in a heterogeneous Fenton system, the possible inhibitory effect of phosphate on the actual removal of organic pollutants should be fully considered.
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| 21. |
- Yang, Xiaofang, et al.
(författare)
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Surface acid-base properties and hydration/dehydration mechanisms of aluminum (hydr)oxides
- 2007
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 308:2, s. 395-404
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, surface physiochemical properties of three typical aluminas, γ-Al(OH)3, γ-Al2O3, and α-Al2O3, were investigated by means of XRD, SEM, TEM, BET surface area, TG/DTA, and potentiometric titration techniques. Based on the titration data, surface protonation and deprotonation constants were determined using the constant capacitance model (CCM). The emphasis of this research was laid on the comparison of the crystal structure, surface hydration/dehydration and acid-base properties of these three typical alumina minerals. The calculation results revealed that the surface acidity of the aluminas is in the order of α-Al2O3>γ-Al(OH)3>γ-Al2O3 after being hydrated for 1 h. The correlation between the hydration/dehydration mechanisms of alumina and its acid/base properties is discussed.
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| 22. |
- Yang, Yuying, et al.
(författare)
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Light-Induced Redox Looping of a Rhodium/CexWO3 Photocatalyst for Highly Active and Robust Dry Reforming of Methane
- 2022
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Ingår i: Angewandte Chemie International Edition. - : John Wiley & Sons. - 1433-7851 .- 1521-3773. ; 61:21
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Tidskriftsartikel (refereegranskat)abstract
- Dry reforming of methane (DRM) has provided an effective avenue to convert two greenhouse gases, CH4 and CO2, into syngas. Here, we design a DRM photocatalyst Rh/CexWO3 that invokes both photothermal and photoelectric processes, which overcomes the thermodynamic limitation of DRM under conventional conditions. In contrast to plasmonic or UV-response photocatalysts, our photocatalyst produces a superior light-to-chemical energy efficiency (LTCEE) of 4.65 % with a moderate light intensity. We propose that a light-induced metal-to-metal charge transfer plays a crucial role in the DRM reaction, which induces a redox looping between Ce to W species to lower the activation energy. Quantum mechanical studies reveal that a high oxygen mobility of CexWO3, accompanied with the formation of oxo-bridge species, results in a substantial elimination of deposited C species during the reaction. Our catalyst design strategy could offer a promising energy-efficient industrial process for DRM.
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| 23. |
- Zhang, Dongsheng, et al.
(författare)
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Thermal properties of TIM using CNTs forest in electronics packaging
- 2016
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Ingår i: 2016 17th International Conference on Electronic Packaging Technology, ICEPT 2016; Wuhan Optics Valley Kingdom Hotel Wuhan; China; 16 August 2016 through 19 August 2016. ; , s. 1355-1359
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Konferensbidrag (refereegranskat)abstract
- Thermal interface material (TIM) is applied to fill the air gaps of interfaces, which provides a path for interfacial heat transfer. Owing to the exceptional thermal properties of carbon nanotubes (CNT), TIMs based on CNTs have received much attention in recent years. In this study, heat dissipation performance of vertically aligned carbon nanotubes (VACNT) arrays as TIM in electronic packing was analyzed. Vertically aligned carbon nanotubes with length of 245?m and 763?m were synthesized on a silicon substrate by chemical vapor deposition respectively. Morphology of the vertically aligned carbon nanotubes was characterized by scanning electron microscope. The hotspot temperature of thermal test chip with vertically aligned carbon nanotubes were characterized by resistance temperature detector method and infrared imaging method.
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| 24. |
- Zhang, Yongfei, et al.
(författare)
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Planar FAPbBr(3) Solar Cells with Power Conversion Efficiency above 10%
- 2018
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Ingår i: ACS Energy Letters. - : American Chemical Society (ACS). - 2380-8195. ; 3:8, s. 1808-1814
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Tidskriftsartikel (refereegranskat)abstract
- Bromide-based hybrid perovskites are of particular interest not only due to the fact that they offer a way to go beyond the Shockley-Queisser limit via the tandem cell scheme but single junction devices of them can also achieve reasonably high efficiency with high stability for solar energy conversion. However, the highest power conversion efficiency achieved up to now for FAPbBr(3) single-junction solar cells is only 8.2%, which is far below the efficiency of-17% predicted from detailed balance analysis. Here, a two-step method (the intermolecule exchange pathway) was systematically optimized for the fabrication of high quality FAPbBr(3) films. A molecule of urea, structurally similar to formamidinium, is introduced as an additive to tune the intermolecular ion exchange procedure. SnO2 is introduced as an electron-selective contact to the planar structured FAPbBr(3) solar cells. As a result, a power conversion efficiency of 10.61% and a V-oc of 1.56 V are achieved with planar structured solar cells, both of which represent the highest value ever reported for FAPbBr(3) solar cells.
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| 25. |
- Zheng, Fengshan, et al.
(författare)
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Experimental observation of chiral magnetic bobbers in B20-type FeGe
- 2018
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Ingår i: Nature Nanotechnology. - : NATURE PUBLISHING GROUP. - 1748-3387 .- 1748-3395. ; 13:6, s. 451-
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Tidskriftsartikel (refereegranskat)abstract
- Chiral magnetic skyrmions(1,2) are nanoscale vortex-like spin textures that form in the presence of an applied magnetic field in ferromagnets that support the Dzyaloshinskii-Moriya interaction (DMI) because of strong spin-orbit coupling and broken inversion symmetry of the crystal(3,4). In sharp contrast to other systems(5,6) that allow for the formation of a variety of two-dimensional (2D) skyrmions, in chiral magnets the presence of the DMI commonly prevents the stability and coexistence of topological excitations of different types(7). Recently, a new type of localized particle-like object-the chiral bobber (ChB)-was predicted theoretically in such materials(8). However, its existence has not yet been verified experimentally. Here, we report the direct observation of ChBs in thin films of B20-type FeGe by means of quantitative off-axis electron holography (EH). We identify the part of the temperature-magnetic field phase diagram in which ChBs exist and distinguish two mechanisms for their nucleation. Furthermore, we show that ChBs are able to coexist with skyrmions over a wide range of parameters, which suggests their possible practical applications in novel magnetic solid-state memory devices, in which a stream of binary data bits can be encoded by a sequence of skyrmions and bobbers.
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