| 1. |
- Beal, Jacob, et al.
(författare)
-
Robust estimation of bacterial cell count from optical density
- 2020
-
Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
-
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.
|
|
| 2. |
- Wu, Wei, et al.
(författare)
-
Roles of Mitogen-Activated Protein Kinases in the Modulation of Endothelial Cell Function Following Thermal Injury
- 2011
-
Ingår i: Shock. - : Biomedical Press. - 1073-2322 .- 1540-0514. ; 35:6, s. 618-625
-
Tidskriftsartikel (refereegranskat)abstract
- Several mitogen-activated protein kinases (MAPKs) are activated during thermal injury, and the p38 MAPK is specifically involved in endothelial cell (EC) actin and myosin rearrangement (stress-fiber formation) with ensuing cellular contraction and enhanced vessel permeability. Inhibition of p38 MAPK and extracellular signal-related kinase MAPK by their inhibitors SB203580 and PD98059, respectively, significantly reduces burn serum-induced EC stress-fiber formation, whereas SB203580 also inhibits burn serum-induced EC tight-junction damage and thereby general blood vessel hyperpermeability. The JNK MAPK inhibitor, SP600125, on the contrary, influences neither stress-fiber formation nor EC tight-junction damage. Extracellular signal-related kinase MAPK inhibition significantly decreases burn serum-induced Monocyte chemotactic protein-1 (MCP-1) release, whereas SB203580 and SP600125 have only limited such effects. Western blotting, real-time reverse transcriptase-polymerase chain reaction, and confocal laser scanning microscopy proved that SP600125 significantly inhibits burn serum-induced intercellular adhesion molecule 1 expression, whereas SB203580 depresses the expression of P selectin. In vivo studies, using the dominant negative adenoviral approach of MAPK kinase 3b and MAPK kinase 6b to block p38 MAPKs, and MKK4 and MKK7 to block JNK MAPKs, show that the latter MAPKs are involved in the regulation of P selectin and intercellular adhesion molecule 1 expression, respectively, following thermal injury. Taken together, the results suggest that several MAPKs play important, although different, roles in general EC alterations following burn injuries.
|
|
| 3. |
- Zhao, Shiyu, et al.
(författare)
-
Evaluation of Defogging : A Real-World Benchmark Dataset, A New Criterion and Baselines
- 2019
-
Ingår i: 2019 IEEE International Conference on Multimedia and Expo (ICME). - Shanghai : IEEE. - 9781538695524 - 9781538695531 ; , s. 1840-1845
-
Konferensbidrag (refereegranskat)abstract
- Modern defogging methods are able to achieve very comparable results whose differences are too subtle for people to qualitatively judge. On the other hand, existing quantitative evaluation methods are also not convincing due to a lack of proper datasets. In this work, we attempt to address these issues and establish a long-term lacking benchmark dataset, namely BeDDE (BEnchmark Dataset for Defogging Evaluation), for evaluating the performance of defogging algorithms. To our knowledge, BeDDE is the first real-world dataset comprising foggy images with their registered clear counterparts. Using BeDDE, we set up a new criterion for evaluating defogging methods where VSI, a full reference image quality assessment metric, is calculated and averaged on registered ROIs of all image pairs. The evaluation results of the proposed criterion correlate well with human judgements. 10 state-of-the-art defogging methods are evaluated as baselines on BeDDE. BeDDE is available online.
|
|
| 4. |
- Gong, Yin, et al.
(författare)
-
Insights into evolution of a rift basin : Provenance of the middle Eocene-lower Oligocene strata of the Beibuwan Basin, South China Sea from detrital zircon
- 2021
-
Ingår i: Sedimentary Geology. - : Elsevier BV. - 0037-0738 .- 1879-0968. ; 419
-
Tidskriftsartikel (refereegranskat)abstract
- Investigating rift basins and their provenance is difficult because their tectonic framework is continuously evolving. The Beibuwan Basin in the South China Sea is a typical rift basin that shares many characteristics of major rift basins worldwide. We present new detrital zircon UPb ages from the Beibuwan basin and, by combining with published data from surrounding drainages, are able to define its potential sources and to investigate its provenance evolution from the middle Eocene-lower Oligocene. Detrital zircon age spectra from distinct structural units and formations of the rift basin reveal spatial-temporal differences in provenance. In the middle-upper Eocene, a similar age pattern with major peaks at 263–253 Ma and 450–416 Ma is preserved across the basin and suggests that sediment was uniformly derived from the Yunkai Massif and Hainan Island. In contrast, during the lower Oligocene the basin displays markedly diverse ages with peaks at 250–243, 416, 756, 967–945, 1096–1084 Ma. The increase of Neoproterozoic zircons in the lower Oligocene stratum suggests that a major change in provenance occurred, most likely associated with the reorganization of the paleo-Pearl River along its central reaches due to a topography reversal associated with the uplift of Tibet and the onset of seafloor spreading in the South China Sea. Our spatial analysis of ages indicates that during the lower Oligocene, the detrital input varied across the basin. Rifting processes in the Beibuwan Basin generated multiple isolated depocenters separated by intra-basinal highs. The basin's architecture greatly affected sediment routing, with structural highs serving as barriers to sediment transport. Sediment provenance in the Beibuwan Basin is primarily controlled by drainage evolution and isolated depocenters associated with an evolving topography, processes which are relevant to the evolution of rift basins globally.
|
|
| 5. |
- Lei, Chengan, et al.
(författare)
-
Controllable dual-polarization valley physics in the strain-engineered 2D monolayer of VC2N4
- 2024
-
Ingår i: Journal of Materials Chemistry C. - : Royal Society of Chemistry. - 2050-7526 .- 2050-7534. ; 12:6, s. 2156-2164
-
Tidskriftsartikel (refereegranskat)abstract
- Valley-related physics has garnered significant attention in fundamental studies and cutting-edge information technologies. However, such valleytronic materials have rarely been reported and suffer from in-plane magnetization. Herein, based on first-principles calculations and tight-binding model analysis, we identify the existence of intrinsic valley-contrasting physics in bipolar ferromagnetic monolayer VC2N4 with robust perpendicular magnetic anisotropy behavior. Valley polarization arises spontaneously due to the simultaneous presence of broken space- and time-inversion symmetries. Interestingly, valley polarization is remarkably observed in both the valence and conduction bands around the K/K′ valley due to large spin splitting, indicating rare dual-polarization valley features, which is advantageous for achieving the captivating anomalous valley Hall effect relied on the valley-contrasting Berry curvature. Remarkably, the valley polarization can be switched on/off by applying a moderate biaxial strain. Our work provides a competitive candidate for exploring valley-dependent physics and its applications in valleytronics.
|
|
| 6. |
- Tang, Weidong, et al.
(författare)
-
The roles of metal oxidation states in perovskite semiconductors
- 2023
-
Ingår i: Matter. - : CELL PRESS. - 2590-2393 .- 2590-2385. ; 6:11, s. 3782-3802
-
Forskningsöversikt (refereegranskat)abstract
- Metal halide perovskites are an emerging materials platform for optoelectronic, spintronic, and thermoelectric applications. The field of perovskite materials and devices has progressed rapidly over the past decade. For halide perovskite materials, a range of physical and chemical properties such as crystal structure, bandgap, charge carrier density, and stability that govern the device functionalities are critically determined by the oxidation states of the B-site metal ions. However, such an important mechanistic connection unique to halide perovskites is not well established, limiting the pace of development in this area. In this review, we identify the roles of metal oxidation states in perovskite semiconductors. The redox reactions leading to these states, and their effects on the materials properties, are clarified. Finally, we suggest routes to improving device efficiency and stability from the perspective of oxidation state control.
|
|
| 7. |
- Zhang, Shiyu, 1992-, et al.
(författare)
-
Continuous trajectory planning based on learning optimization in high dimensional input space for serial manipulators
- 2022
-
Ingår i: Engineering optimization (Print). - : Taylor & Francis. - 0305-215X .- 1029-0273. ; 54:10, s. 1724-1742
-
Tidskriftsartikel (refereegranskat)abstract
- In order to generate trajectories continuously for serial manipulators with high dimensional degrees of freedom (DOFs) in a dynamic environment, a real-time trajectory planning method based on optimization and machine learning aimed at high dimensional inputs is presented. A learning optimization (LO) framework is established. Multiple criteria are defined to evaluate the performance quantitatively, and implementations with different sub-methods are discussed. In particular, a database generation method based on input space mapping is proposed for generating valid and representative samples. The methods presented are applied on a practical application-haptic interaction in virtual reality systems. The results show that the input space mapping method significantly elevates the efficiency and quality of database generation and consequently improves the performance of the LO. With the LO method, real-time trajectory generation with high dimensional inputs is achieved, which lays the foundation for robots with high dimensional DOFs to execute complex tasks in dynamic environments.
|
|
| 8. |
- Zhao, Shiyu, et al.
(författare)
-
A General Approach to Coordination Control of Mobile Agents With Motion Constraints
- 2018
-
Ingår i: IEEE Transactions on Automatic Control. - : IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC. - 0018-9286 .- 1558-2523. ; 63:5, s. 1509-1516
-
Tidskriftsartikel (refereegranskat)abstract
- This paper proposes a general approach to design convergent coordination control laws for multiagent systems subject to motion constraints. The main contribution of this paper is to prove in a constructive way that a gradient-descent coordination control law designed for single integrators can be easily modified to adapt for various motion constraints such as nonholonomic dynamics, linear/angular velocity saturation, and other path constraints while preserving the convergence of the entire multiagent system. The proposed approach is applicable to a wide range of coordination tasks such as rendezvous and formation control in two and three dimensions. As a special application, the proposed approach solves the problem of distance-based formation control subject to nonholonomic and velocity saturation constraints.
|
|
