| 1. |
- Beal, Jacob, et al.
(author)
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Robust estimation of bacterial cell count from optical density
- 2020
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In: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Journal article (peer-reviewed)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. |
- Kristan, Matej, et al.
(author)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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In: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
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Conference paper (peer-reviewed)abstract
- The Visual Object Tracking challenge VOT2021 is the ninth annual tracker benchmarking activity organized by the VOT initiative. Results of 71 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in recent years. The VOT2021 challenge was composed of four sub-challenges focusing on different tracking domains: (i) VOT-ST2021 challenge focused on short-term tracking in RGB, (ii) VOT-RT2021 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2021 focused on long-term tracking, namely coping with target disappearance and reappearance and (iv) VOT-RGBD2021 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2021 dataset was refreshed, while VOT-RGBD2021 introduces a training dataset and sequestered dataset for winner identification. The source code for most of the trackers, the datasets, the evaluation kit and the results along with the source code for most trackers are publicly available at the challenge website(1).
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| 3. |
- Cao, Wei, et al.
(author)
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Self-Assembly of Large Magnetic Nanoparticles in Ultrahigh Molecular Weight Linear Diblock Copolymer Films
- 2020
-
In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 12:6, s. 7557-7564
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Journal article (peer-reviewed)abstract
- The development of diblock copolymer (DBC) nanocomposite films containing magnetic nanoparticles (NPs) with diameters (D) over 20 nm is a challenging task. To host large iron oxide NPs (Fe3O4, D = 27 +/- 0.6 nm), an ultrahigh molecular weight (UHMW) linear DBC polystyrene-block-poly(methyl methacrylate) (PS-b-PMMA) is used as a template in the present work. Due to hydrogen bonding between the carboxylic acid ligands of the NPs and the ester groups in PMMA, the NPs show an affinity to the PMMA block. The localization of the NPs inside the DBC is investigated as a function of the NP concentration. At low NP concentrations, NPs are located preferentially at the interface between PS and PMMA domains to minimize the interfacial tension caused by the strong segregation strength of the UHMW DBC. At high NP concentrations (>= 10 wt %), chain-like NP aggregates (a head-to-tail orientation) are observed in the PMMA domains, resulting in a change of the morphology from sphere to ellipsoid for part of the PMMA domains. Magnetic properties of the hybrid films are probed via superconducting quantum interference device magnetometry. All hybrid films show ferrimagnetism and are promising for potential applications in magnetic data storage.
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| 4. |
- Chen, Yinglu, et al.
(author)
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Heavy sulfur isotopes recorded in contrasted redox conditions in Holocene sediments from the Yangtze River Delta
- 2024
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In: Chemical Geology. - : Elsevier. - 0009-2541 .- 1872-6836. ; 663
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Journal article (peer-reviewed)abstract
- Sulfur isotopic signatures of pyrite (δ34Spy) sensitively react to local environmental change. Here we elucidate mechanism of δ34Spy variation in the Holocene sedimentary strata of the Yangtze River Delta, through the analyses of multiple geochemical and physical indicators including total organic carbon, total nitrogen, stable isotopes of organic carbon, different iron solid phases, Sr/Ba ratios, and changes in sedimentation rates. Two heavy δ34Spy (∼30‰) layers that formed under contrasting redox conditions are preserved in the early Holocene transgressive tidal flat and late Holocene regressive mouth bar facies, respectively. Two hypotheses are proposed to explain these heavy δ34Spy layers: 1) in the transgression process, the heavy δ34Spy layers formed under stronger reducing conditions due to methane leakage; 2) in the regression process, the heavy δ34Spy layers formed under relatively weaker reducing conditions due to rapid deposition and low salinity. This study emphasizes the importance of physicochemical condition characterization in sediments, including redox conditions, in distinguishing the mechanisms that act to produce heavy δ34Spy signals.
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| 5. |
- Dong, Xiaoyu, et al.
(author)
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Gait Recognition Based on Modified OVR-CSP Fusion Feature and LSTM
- 2024
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In: 2024 7th International Conference on Advanced Algorithms and Control Engineering, ICAACE 2024. - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 1551-1554
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Conference paper (peer-reviewed)abstract
- This paper proposes a gait recognition method based on the modified OVR-CSP fusion feature of plantar pressure and Long Short-Term Memory classification (referred to as the OVR-CSP-LSTM model). 10 subjects conducted 4 type of gait experiments including normal speed walking, fast walking, slow walking, imitating stroke gait walking in this paper. Transfer the commonly used Common Spatial Pattern (CSP) feature extraction method for EEG to plantar pressure signals, and splice the OVR-CSP features of 2-class, 3-class and 4-class, adopting Long Short Term Memory Network (LSTM) for classification. In this paper, the Intra-patient mode and Inter-patient mode of 10 people are modeled and compared respectively, and the recognition effects under different sensor number and different position sensors' combination are also studied. The experimental results show that the proposed model has good performance for both modes. The method proposed in this article is expected to be applied to multi-sensor signal processing and classification with spatial characteristics.
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| 6. |
- Hart, Lucy J. F., et al.
(author)
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Understanding the Role of Triplet-Triplet Annihilation in Non-Fullerene Acceptor Organic Solar Cells
- 2023
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In: Advanced Energy Materials. - : WILEY-V C H VERLAG GMBH. - 1614-6832 .- 1614-6840. ; 13:36
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Journal article (peer-reviewed)abstract
- Non-fullerene acceptors (NFAs) have enabled power conversion efficiencies exceeding 19% in organic solar cells (OSCs). However, the open-circuit voltage of OSCs remains low relative to their optical gap due to excessive non-radiative recombination, and this now limits performance. Here, an important aspect of OSC design is considered, namely management of the triplet exciton population formed after non-geminate charge recombination. By comparing the blends PM6:Y11 and PM6:Y6, it is shown that the greater crystallinity of the NFA domains in PM6:Y11 leads to a higher rate of triplet-triplet annihilation (TTA). This is attributed to the four times larger ground state dipole moment of Y11 versus Y6, which improves the long range NFA out-of-plane ordering. Since TTA converts a fraction of the non-emissive triplet states into bright singlet states, it has the potential to reduce non-radiative voltage losses. Through a kinetic analysis of the recombination processes under 1-Sun illumination, a framework is provided for determining the conditions under which TTA may improve OSC performance. If these could be satisfied, TTA has the potential to reduce non-radiative voltage losses by up to several tens of millivolts.
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| 7. |
- Ji, Xinyu, et al.
(author)
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Epigenetic–smoking interaction reveals histologically heterogeneous effects of TRIM27 DNA methylation on overall survival among early-stage NSCLC patients
- 2020
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In: Molecular Oncology. - : Wiley. - 1574-7891 .- 1878-0261. ; 14:11, s. 2759-2774
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Journal article (peer-reviewed)abstract
- Tripartite motif containing 27 (TRIM27) is highly expressed in lung cancer, including non-small-cell lung cancer (NSCLC). Here, we profiled DNA methylation of lung adenocarcinoma (LUAD) and lung squamous cell carcinoma (LUSC) tumours from 613 early-stage NSCLC patients and evaluated associations between CpG methylation of TRIM27 and overall survival. Significant CpG probes were confirmed in 617 samples from The Cancer Genome Atlas. The methylation of the CpG probe cg05293407TRIM27 was significantly associated with overall survival in patients with LUSC (HR = 1.65, 95% CI: 1.30–2.09, P = 4.52 × 10−5), but not in patients with LUAD (HR = 1.08, 95% CI: 0.87–1.33, P = 0.493). As incidence of LUSC is associated with higher smoking intensity compared to LUAD, we investigated whether smoking intensity impacted on the prognostic effect of cg05293407TRIM27 methylation in NSCLC. LUSC patients had a higher average pack-year of smoking (37.49LUAD vs 54.79LUSC, P = 1.03 × 10−19) and included a higher proportion of current smokers than LUAD patients (28.24%LUAD vs 34.09%LUSC, P = 0.037). cg05293407TRIM27 was significantly associated with overall survival only in NSCLC patients with medium–high pack-year of smoking (HR = 1.58, 95% CI: 1.26–1.96, P = 5.25 × 10−5). We conclude that cg05293407TRIM27 methylation is a potential predictor of LUSC prognosis, and smoking intensity may impact on its prognostic value across the various types of NSCLC.
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| 8. |
- Jiang, Xinyu, et al.
(author)
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Film Formation Kinetics of Polymer Donor and Nonfullerene Acceptor Active Layers During Printing Out of 1,2,4-Trimethylbenzene in Ambient Conditions
- 2023
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In: Solar RRL. - : Wiley. - 2367-198X. ; 7:6
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Journal article (peer-reviewed)abstract
- Slot-die coating is a promising upscaling fabrication method to promote commercialization in the field of organic solar cells. Herein, the nonfullerene active layer blend of a conjugated polymer PffBT4T-2OD and a small molecule acceptor EH-IDTBR, which is printed out of the nonhalogenated solvent 1,2,4-trimethylbenzene, is studied. The film formation kinetics of the active layer PffBT4T-2OD:EH-IDTBR is probed in terms of the temporal evolutions in morphology as well as molecular conformation and aggregation as revealed by in situ grazing-incidence small angle X-ray scattering and UV–vis spectroscopy during the film printing process. A five-regime mesoscale domain growth process is observed in the active layer from the liquid state to the final dry state. The solvent evaporation-induced domain growth is accompanied with molecular stacking in a distinct J-type aggregation of the acceptor and a slight H-type aggregation of the donor molecules. The printed active layers exhibit an edge-on dominated PffBT4T-2OD and a face-on dominated EH-IDTBR crystallite structure. Compared to the neat PffBT4T-2OD and EH-IDTBR films, in the active layer, the crystallite structure deviates slightly in lattice spacing.
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| 9. |
- Jiang, Xinyu, et al.
(author)
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Internal nanoscale architecture and charge carrier dynamics of wide bandgap non-fullerene bulk heterojunction active layers in organic solar cells
- 2020
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In: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 8:44, s. 23628-23636
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Journal article (peer-reviewed)abstract
- Bulk heterojunction (BHJ) organic solar cells have gained increasing attention in the past few years. In this work, active layers of a wide-bandgap polymer donor with benzodithiophene units PBDB-T-2F and a non-fullerene small molecule acceptor IT-M are assembled into photovoltaic devices with different amounts of solvent additive 1,8-diiodooctane (DIO). The influence of DIO on the nanoscale film morphology and crystalline structure as well as the charge carrier dynamics of the active layers are investigated by combining grazing-incidence small-angle X-ray scattering (GISAXS), grazing-incidence wide-angle X-ray scattering (GIWAXS), X-ray reflectivity (XRR), UV-visible (UV-vis) absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), time-resolved photoluminescence (TRPL) and space charge limited current measurements, which are correlated with the corresponding performance of the solar cells. At 0.5 vol% DIO addition, the wide-bandgap non-fullerene organic solar cells show the best performance due to high open-circuit voltage and short-circuit current resulting from an improved charge carrier management due to the optimal inner nanoscale morphology of the active layers in terms of surface enrichment, crystallinity and crystalline orientation.
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| 10. |
- Liu, Xinyu, et al.
(author)
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Vehicle trajectory prediction through manual setting and machine learning
- 2022
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In: ISCTT 2022 - 7th International Conference on Information Science, Computer Technology and Transportation. ; , s. 612-616
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Conference paper (peer-reviewed)abstract
- The prediction of vehicle trajectory is an important step in safe driving. The relative positions or speeds of vehicles affect the interactions between them, which in turn produce predictions of trajectories. Through the trajectory prediction of each vehicle to form a complete safe driving environment. This paper will be divided into two parts for vehicle track, namely manual setting and machine learning. The advantage of manual setting is that it is convenient to observe the characteristics and then make other vehicles follow the corresponding behaviour. However, the disadvantage is that the characteristics that can be observed are incomplete, which makes the experimental error relatively large. The advantage of machine learning is that through previous experience to make all vehicles change in the corresponding situation. Through previous experience to make all vehicles change in the corresponding situation. An effective extraction and addition of the original data is helpful to reduce the final error. Our code base can be found in https://github.com/RR30/CIS_multi_vehicle_prediction/tree/Xinyu.
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| 11. |
- Tu, Suo, et al.
(author)
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Improvement of the thermoelectric properties of PEDOT:PSS films via DMSO addition and DMSO/salt post-treatment resolved from a fundamental view
- 2022
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 429
-
Journal article (peer-reviewed)abstract
- The combination of dimethyl sulfoxide (DMSO)-solvent doping and physical-chemical DMSO/salt de-doping in a sequence has been used to improve the thermoelectric (TE) properties of poly(3,4-ethylenedioxythiophene):poly (4-styrenesulfonate) (PEDOT:PSS) films. A high power factor of ca.105.2 mu W m(-1) K-2 has been achieved for the PEDOT:PSS film after post-treatment with 10 % sodium sulfite (Na2SO3) in the DMSO/salt mixture (v/v), outperforming sodium bicarbonate (NaHCO3). The initial DMSO-doping treatment induces a distinct phase separation by facilitating the aggregation of the PEDOT molecules. At the same time, the subsequent DMSO/salt dedoping post-treatment strengthens the selective removal of the surplus non-conductive PSS chains. Substantial alterations in the oxidation level, chain conformations, PEDOT crystallites and their preferential orientation are observed upon treatment on the molecular level. At the mesoscale level, the purification and densification of PEDOT-rich domains enable the realization of inter-grain coupling by the formation of the electronically well-percolated network. Thereby, both electrical conductivity and Seebeck coefficient are optimized.
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| 12. |
- Wang, Yilin, et al.
(author)
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Control of the Crystallization and Phase Separation Kinetics in Sequential Blade-Coated Organic Solar Cells by Optimizing the Upper Layer Processing Solvent
- 2023
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In: Advanced Energy Materials. - : Wiley. - 1614-6832 .- 1614-6840. ; 13:7
-
Journal article (peer-reviewed)abstract
- Sequential deposition of the active layer in organic solar cells (OSCs) is favorable to circumvent the existing drawbacks associated with controlling the microstructure in bulk-heterojunction (BHJ) device fabrication. However, how the processing solvents impact on the morphology during sequential deposition processes is still poorly understood. Herein, high-efficiency OSCs are fabricated by a sequential blade coating (SBC) through optimization of the morphology evolution process induced by processing solvents. It is demonstrated that the device performance is highly dependent on the processing solvent of the upper layer. In situ morphology characterizations reveal that an obvious liquid–solid phase separation can be identified during the chlorobenzene processing of the D18 layer, corresponding to larger phase separation. During chloroform (CF) processing of the D18 layer, a proper aggregation rate of Y6 and favorable intermixing of lower and upper layers results in the enhanced crystallinity of the acceptor. This facilitates efficient exciton dissociation and charge transport with an inhibited charge recombination in the D18/CF-based devices, contributing to a superior performance of 17.23%. These results highlight the importance of the processing solvent for the upper layer in the SBC strategy and suggest the great potential of achieving optimized morphology and high-efficiency OSCs using the SBC strategy.
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| 13. |
- Wienhold, Kerstin S., et al.
(author)
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Effect of Solvent Additives on the Morphology and Device Performance of Printed Nonfullerene Acceptor Based Organic Solar Cells
- 2019
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In: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 11:45, s. 42313-42321
-
Journal article (peer-reviewed)abstract
- Printing of active layers of high-efficiency organic solar cells and morphology control by processing with varying solvent additive concentrations are important to realize real-world use of bulk-heterojunction photovoltaics as it enables both up-scaling and optimization of the device performance. In this work, active layers of the conjugated polymer with benzodithio-phene units PBDB-T-SF and the nonfullerene small molecule acceptor IT-4F are printed using meniscus guided slot-die coating. 1,8-Diiodooctane (DIO) is added to optimize the power conversion efficiency (PCE). The effect on the inner nanostructure and surface morphology of the material is studied for different solvent additive concentrations with grazing incidence small-angle X-ray scattering (GISAXS), grazing incidence wide-angle X-ray scattering (GIWAXS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Optical properties are studied with photoluminescence (PL), UV/vis absorption spectroscopy, and external quantum efficiency (EQE) measurements and correlated to the corresponding PCEs. The addition of 0.25 vol % DIO enhances the average PCE from 3.5 to 7.9%, whereas at higher concentrations the positive effect is less pronounced. A solar cell performance of 8.95% is obtained for the best printed device processed with an optimum solvent additive concentration. Thus, with the large-scale preparation method printing similarly well working solar cells can be realized as with the spin-coating method.
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| 14. |
- Yin, Shanshan, et al.
(author)
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Tailored fabrication of quasi-isoporous and double layered alpha-Fe2O3 thin films and their application in photovoltaic devices
- 2023
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In: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 455, s. 140135-
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Journal article (peer-reviewed)abstract
- A series of α-Fe2O3 thin films with distinct morphologies are prepared via a facile polystyrene-block-polyethylene oxide templated sol–gel method. By tailoring the poor solvent contents and FeCl3-to-polymer weight ratio in the sol–gel solutions, quasi-isoporous α-Fe2O3 thin films with different substructures and thicknesses are obtained. Via a thermal annealing post-treatment, double layered structures are induced by a synergistic dewetting and Oswald ripening effect. Special focus is set on the α-Fe2O3 thin films prepared with no annealing/annealing-medium FeCl3 concentration, as they possess uniform periodic structures, which is suitable to be used as hole blocking modification layer of perovskite solar cells (PSCs). An improved power conversion efficiency (PCE) is obtained when the double layered α-Fe2O3 thin film is applied as the hole blocking modification layer for PSCs. The improved PCE primarily originates from the increased VOC, which probably benefits from the synergistic effect of the suppressed charge carrier recombination at the interfaces, the enhanced light transmittance as well as the superior electron extraction capacity.
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