| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
- Liang, Lin, et al.
(författare)
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Non-Interpenetrated Single-Crystal Covalent Organic Frameworks
- 2020
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Ingår i: Angewandte Chemie International Edition. - : Wiley. - 1433-7851 .- 1521-3773. ; 59:41, s. 17991-17995
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Tidskriftsartikel (refereegranskat)abstract
- Growth of covalent organic frameworks (COFs) as single crystals is extremely challenging. Inaccessibility of open-structured single-crystal COFs prevents the exploration of structure-oriented applications. Herein we report for the first time a non-interpenetrated single-crystal COF, LZU-306, which possesses the open structure constructed exclusively via covalent assembly. With a high void volume of 80 %, LZU-306 was applied to investigate the intrinsic dynamics of reticulated tetraphenylethylene (TPE) as the individual aggregation-induced-emission moiety. Solid-state(2)H NMR investigation has determined that the rotation of benzene rings in TPE, being the freest among the reported cases, is as fast as 1.0x10(4) Hz at 203 K to 1.5x10(7) Hz at 293 K. This research not only explores a new paradigm for single-crystal growth of open frameworks, but also provides a unique matrix-isolation platform to reticulate functional moieties into a well-defined and isolated state.
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| 3. |
- Borthakur, Dulal, et al.
(författare)
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Current status and trends in forest genomics
- 2022
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Ingår i: Forestry Research. - : Maximum Academic Press. - 2767-3812. ; 2
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Forskningsöversikt (refereegranskat)abstract
- Forests are not only the most predominant of the Earth's terrestrial ecosystems, but are also the core supply for essential products for human use. However, global climate change and ongoing population explosion severely threatens the health of the forest ecosystem and aggravtes the deforestation and forest degradation. Forest genomics has great potential of increasing forest productivity and adaptation to the changing climate. In the last two decades, the field of forest genomics has advanced quickly owing to the advent of multiple high-throughput sequencing technologies, single cell RNA-seq, clustered regularly interspaced short palindromic repeats (CRISPR)-mediated genome editing, and spatial transcriptomes, as well as bioinformatics analysis technologies, which have led to the generation of multidimensional, multilayered, and spatiotemporal gene expression data. These technologies, together with basic technologies routinely used in plant biotechnology, enable us to tackle many important or unique issues in forest biology, and provide a panoramic view and an integrative elucidation of molecular regulatory mechanisms underlying phenotypic changes and variations. In this review, we recapitulated the advancement and current status of 12 research branches of forest genomics, and then provided future research directions and focuses for each area. Evidently, a shift from simple biotechnology-based research to advanced and integrative genomics research, and a setup for investigation and interpretation of many spatiotemporal development and differentiation issues in forest genomics have just begun to emerge.
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| 4. |
- Chen, Hongting, et al.
(författare)
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High-Efficiency Formamidinium Lead Bromide Perovskite Nanocrystal-Based Light-Emitting Diodes Fabricated via a Surface Defect Self-Passivation Strategy
- 2020
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Ingår i: Advanced Optical Materials. - : WILEY-V C H VERLAG GMBH. - 2162-7568 .- 2195-1071. ; 8:6
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Tidskriftsartikel (refereegranskat)abstract
- Formamidinium lead bromide (FAPbBr(3)) nanocrystals (NCs) demonstrate great potential in light-emitting diode (LED) applications due to their pure green emission and excellent stability. However, the abundant defects at the surface of the NCs act as charge trapping centers and significantly increase the trap-assisted nonradiative recombination channels, hampering the performance improvement of LEDs based on FAPbBr(3) NCs. Herein, a facile self-passivation strategy of the surface defects is developed by introducing excess formamidinium bromide (FABr) during the colloidal synthesis of NCs, leading to much improved photoluminescence quantum yield (PLQY) of the obtained NCs. In addition, enhanced charge transport property is measured in the assembled films owing to the simultaneously declined insulating ligands at the surface of NCs. The molar ratio of FABr and PbBr2 is rationally optimized during the synthesis of NCs and high-efficient green-emissive LEDs are fabricated with a champion current efficiency of 76.8 cd A(-1), corresponding to an external quantum efficiency of 17.1%, which is among the best-performing green LEDs based on perovskite NCs so far.
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| 5. |
- Chen, Zheng wei, et al.
(författare)
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Reducing the aerodynamic drag of high-speed trains by air blowing from the nose part: Effect of blowing speed
- 2023
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Ingår i: Journal of Wind Engineering and Industrial Aerodynamics. - 0167-6105. ; 238
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Tidskriftsartikel (refereegranskat)abstract
- To reduce the aerodynamic drag of high-speed trains, this work proposes an air blowing configuration on the head and tail cars of high-speed trains. The variation in the aerodynamic drag and slipstream velocity is analyzed under different blowing velocities, and the flow mechanism for train aerodynamic performance alteration is explained. The results show that under the blowing speeds of Ub = 0.05Ut, 0.10Ut, 0.15Ut, and 0.20Ut, where Ut is the train speed, the total drag coefficient (Cd) decreases by 5.81%, 10.78%, 13.70%, and 15.43% compared to the without-blowing case, respectively. However, with the increase in the blowing speed, the reduction trend of Cd tends to be smoother; namely, the decrement ratio compared to the previous blowing speed for the head car is 9.08%, 0.11%, 0.60%, and 1.14% for Ub = 0.05Ut, 0.10Ut, 0.15Ut, and 0.20Ut, respectively. The blowing measure generates an air gap between the coming flow and train surface, consequently causing a reduction in the viscous and pressure drag. In addition, the structure size and strength of the wake flow under different blowing cases show a decreasing trend from Ub = 0.00Ut to 0.10Ut and then an increasing trend from Ub = 0.10Ut to 0.20Ut. Thus, considering the blowing cost, efficiency, and flow structure evolution comprehensively, the case of Ub = 0.10Ut is recommended. Under this blowing speed, the reduction ratio of the aerodynamic drag is 9.18%, 12.77%, 10.90%, and 10.78% for the head, middle, tail car, and total train, respectively.
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| 6. |
- Greco, Rossella, et al.
(författare)
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Activation of 2D cobalt hydroxide with 0D cobalt oxide decoration for microplastics degradation and hydrogen evolution
- 2023
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Ingår i: Chemical Engineering Journal. - 1385-8947. ; 471
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Tidskriftsartikel (refereegranskat)abstract
- The 2D semiconductors are important players in environmental and energy fields due to their unique catalytic and physical properties defined by their dimensionality. Versatile functionalities on one 2D matrix will enlarge its application scopes but require dedicated engineering paths. In this work, we present a cross-dimensional strategy by decorating 0D Co3O4 onto 2D Co(OH)2 to form a multifunctional photocatalyst. The one-pot hydrothermally synthesized Co3O4@Co(OH)2 composite is capable of degrading polystyrene microplastics with an efficiency of 40% under 0.495 W white LED illumination. In a separated experiment, H2 evolution reaction from water splitting was evaluated in absence of sacrificial agents leading to 43 μmol g−1 and to an apparent quantum efficiency of 3.48% at 420 nm. The study of the energy band diagrams by UV–Visible and ambient photoemission spectroscopy and the analysis of the radicals involved in the reaction of photocatalytic degradation allow to unveil the mechanisms for both the processes herein studied. Finally, we could confirm that the heterostructure benefits the redox potentials of 2D and 0D counterparts and facile electron transfers when crossing two different dimensions. These results provide guidelines and inspiration for cross-dimensional activations of low-dimensional materials for versatile functionalities.
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| 7. |
- Ha, S., et al.
(författare)
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Transmission of low-energy Cl- ions through Al2O3 insulating nanocapillaries
- 2020
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Ingår i: Acta Physica Sinica. - : Acta Physica Sinica, Chinese Physical Society and Institute of Physics, Chinese Academy of Sciences. - 1000-3290. ; 69:9
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Tidskriftsartikel (refereegranskat)abstract
- The transmission of 10-keV Cl- ions through Al2O3 insulating nanocapillaries is studied both by experiment and simulation. The double-peak structure in the transmitted angular distribution is found to be the same as our previous result. The peak around the direction of the primary beam is caused mainly by the directly transmitted Cl-, and the other peak around the tilt angle of Al2O3 nanocapillaries is mainly induced by Cl+ and Cl-0. The intensity of transmitted Cl- decreases with the tilt angle increasing, which is in accord with the geometrically allowed transmission. Beyond the geometrically allowed angle, the transmitted projectiles are mainly Cl+ ions and Cl-0 atoms. The ratio of transmitted Cl+ ion to Cl-0 atom drops as tilt angle increases, and it turns more obvious when the tilt angle is larger than the limit of the geometrical transmission. A detailed physics process was developed within Geometry and Tracking 4 (Geant4) to perform the trajectory simulation, in which the forces from the deposited charges and the image charges, the scattering from the surfaces as well as the charge exchange are taken into consideration. The transmissions at the tilt angle of 1.6 degrees are simulated for the cases without and with deposited charges of -100 e/capillary. For the deposition charge quantity of -100 e/capillary, the majority of the transmitted projectiles are mainly the directly transmitted Cl- ions exiting to the direction of tilt angle, and the transmitted Cl-0 and Cl+ account for a very small portion. While for the case with no deposited charges, the simulation results agree well with the experimental results. The dependence of the scattering process on the tilt angle, which results in the different features in the transmitted projectiles, is studied in detail by the simulation. It is found that the transmitted Cl-0 atoms exit through single to multiple scattering, and most of transmitted Cl-0 atoms exit through single and double scattering, and are centered along the axis of nanocapillaries, while Cl+ ions mainly exit by single scattering, which results in the fact that the intensity of the transmitted Cl-0 atoms drops slower than that of the transmitted Cl+ ions with the increase of the tilt angle, leading the ratio of the transmitted Cl+ to Cl-0 to decrease as the tilt angle increases in experiment. Our results describe the physical mechanism of low-energy ions through insulating nanocapillaries in detail, i.e. how the scattering process dominates the final transmission. It is found that the transmission of the negative ions in the energy range above 10 keV is caused by the scattering and the charge exchange process.
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| 8. |
- Kristan, Matej, et al.
(författare)
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The Ninth Visual Object Tracking VOT2021 Challenge Results
- 2021
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Ingår i: 2021 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW 2021). - : IEEE COMPUTER SOC. - 9781665401913 ; , s. 2711-2738
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Konferensbidrag (refereegranskat)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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| 9. |
- Li, Xuechao, et al.
(författare)
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Direct transformation of n-alkane into all-trans conjugated polyene via cascade dehydrogenation
- 2021
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Ingår i: National Science Review. - : Oxford University Press. - 2095-5138 .- 2053-714X. ; 8:10
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Tidskriftsartikel (refereegranskat)abstract
- Selective C(sp(3))-H activation is of fundamental importance in processing alkane feedstocks to produce high-value-added chemical products. By virtue of an on-surface synthesis strategy, we report selective cascade dehydrogenation of n-alkane molecules under surface constraints, which yields monodispersed all-trans conjugated polyenes with unprecedented length controllability. We are also able to demonstrate the generality of this concept for alkyl-substituted molecules with programmable lengths and diverse functionalities, and more importantly its promising potential in molecular wiring.
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| 10. |
- Luo, Yifei, et al.
(författare)
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Technology Roadmap for Flexible Sensors
- 2023
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Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:6, s. 5211-5295
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Forskningsöversikt (refereegranskat)abstract
- Humans rely increasingly on sensors to address grand challenges and to improve quality of life in the era of digitalization and big data. For ubiquitous sensing, flexible sensors are developed to overcome the limitations of conventional rigid counterparts. Despite rapid advancement in bench-side research over the last decade, the market adoption of flexible sensors remains limited. To ease and to expedite their deployment, here, we identify bottlenecks hindering the maturation of flexible sensors and propose promising solutions. We first analyze challenges in achieving satisfactory sensing performance for real-world applications and then summarize issues in compatible sensor-biology interfaces, followed by brief discussions on powering and connecting sensor networks. Issues en route to commercialization and for sustainable growth of the sector are also analyzed, highlighting environmental concerns and emphasizing nontechnical issues such as business, regulatory, and ethical considerations. Additionally, we look at future intelligent flexible sensors. In proposing a comprehensive roadmap, we hope to steer research efforts towards common goals and to guide coordinated development strategies from disparate communities. Through such collaborative efforts, scientific breakthroughs can be made sooner and capitalized for the betterment of humanity.
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