| 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. |
|
|
| 3. |
- Luo, Yifei, et al.
(författare)
-
Technology Roadmap for Flexible Sensors
- 2023
-
Ingår i: ACS Nano. - : American Chemical Society. - 1936-0851 .- 1936-086X. ; 17:6, s. 5211-5295
-
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.
|
|
| 4. |
- Liang, Zuozhong, et al.
(författare)
-
Quasi-single-crystalline CoO hexagrams with abundant defects for highly efficient electrocatalytic water oxidation
- 2018
-
Ingår i: Chemical Science. - : Royal Society of Chemistry (RSC). - 2041-6520 .- 2041-6539. ; 9:34, s. 6961-6968
-
Tidskriftsartikel (refereegranskat)abstract
- Defects and structural long-range ordering have been recognized as two crucial characters for advanced electrocatalysts. However, these two features have rarely been achieved together. Herein, we report the preparation of single-crystalline CoO hexagrams and demonstrate their exceptional electrocatalytic properties for water oxidation. The quasi-single-crystalline CoO hexagrams, prepared at the critical phase transition point of -Co(OH)(2)/Co(OH)F hexagrams, possess both abundant oxygen vacancies as defects and structural long-range ordering. The matching between the b-axis of Co(OH)F crystals and the a-axis of -Co(OH)(2) crystals is critical for the formation of the CoO hexagram single crystals. The quasi-single-crystalline CoO hexagrams with abundant defects are highly efficient for water oxidation by delivering a 10 mA cm(-2) current density at a low overpotential of 269 mV in a 1 M KOH aqueous solution.
|
|
| 5. |
- Chen, Anqi, et al.
(författare)
-
Highly Sensitive Graphene Oxide-based Fabry-Perot Low-frequency Acoustic Sensor With Low-coherence Polarized Demodulation Using Three-step Phase-Shifting Arctan Algorithms
- 2024
-
Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; In Press
-
Tidskriftsartikel (refereegranskat)abstract
- Developing low-frequency acoustic senor with high sensitivity is crucial for diverse applications, ranging from seismic monitoring, military operations, to pipeline surveillance. Here, we have proposed a high-sensitivity graphene oxide (GO)-based Fabry-Perot low-frequency sensor, in which a 170 nm thick, large-area and uniformly GO film was prepared by a vacuum filtration method. To enhance the accuracy and stability of the sensor, a low-coherence interference system based on birefringent crystal blocks was designed utilizing a three-step phase-shifting arctangent algorithm. Our sensor exhibited a sensitivity of -93.48 dB re 1 rad/μPa at 6-60 Hz with a fluctuation of 0.6 dB. The minimum detectable pressure of the sensor was measured at 0.37 μPa/Hz1/2 @20 Hz with a signal to noise ratio of 135.41 dB. Overall, this sensor offers simplicity in preparation, high sensitivity, low detectable sound pressure, making it a significant asset for low-frequency acoustic applications.
|
|
| 6. |
- Ching, Tao-Chung, et al.
(författare)
-
The JCMT BISTRO-2 Survey: Magnetic Fields of the Massive DR21 Filament
- 2022
-
Ingår i: Astrophysical Journal. - : American Astronomical Society. - 1538-4357 .- 0004-637X. ; 941:2
-
Tidskriftsartikel (refereegranskat)abstract
- We present 850 mu m dust polarization observations of the massive DR21 filament from the B-fields In STar-forming Region Observations (BISTRO) survey, using the POL-2 polarimeter and the SCUBA-2 camera on the James Clerk Maxwell Telescope. We detect ordered magnetic fields perpendicular to the parsec-scale ridge of the DR21 main filament. In the subfilaments, the magnetic fields are mainly parallel to the filamentary structures and smoothly connect to the magnetic fields of the main filament. We compare the POL-2 and Planck dust polarization observations to study the magnetic field structures of the DR21 filament on 0.1-10 pc scales. The magnetic fields revealed in the Planck data are well-aligned with those of the POL-2 data, indicating a smooth variation of magnetic fields from large to small scales. The plane-of-sky magnetic field strengths derived from angular dispersion functions of dust polarization are 0.6-1.0 mG in the DR21 filament and similar to 0.1 mG in the surrounding ambient gas. The mass-to-flux ratios are found to be magnetically supercritical in the filament and slightly subcritical to nearly critical in the ambient gas. The alignment between column density structures and magnetic fields changes from random alignment in the low-density ambient gas probed by Planck to mostly perpendicular in the high-density main filament probed by James Clerk Maxwell Telescope. The magnetic field structures of the DR21 filament are in agreement with MHD simulations of a strongly magnetized medium, suggesting that magnetic fields play an important role in shaping the DR21 main filament and subfilaments.
|
|
| 7. |
- Hou, Qichao, et al.
(författare)
-
Different Doping Behaviors of Silicon in Zinc Blende and Wurtzite GaAs Nanowires : Implications for Crystal-Phase Device Design
- 2023
-
Ingår i: ACS Applied Nano Materials. - 2574-0970. ; 6:13, s. 11465-11471
-
Tidskriftsartikel (refereegranskat)abstract
- Crystal-phase engineering between zinc blende (ZB) and wurtzite (WZ) structures is becoming an important method in designing unique optoelectronic and electronic semiconductor devices. Doping to engineer their electric properties is thus of critical importance, but a direct experimental comparison in doping these two crystal structures is still missing. Nanowires (NWs) allow the coexistence of both structures due to their special growth mode. The differences in dopant incorporation between the two phases are studied here in GaAs NW shells that are coherently grown around the NWs, hence maintaining the crystal structure of the core. The Si dopant is observed to have a higher incorporation efficiency into the WZ structure due to a 2 times lower incorporation energy compared with that of the ZB structure. Besides, it can also be predicted that Si is more inclined toward Ga sites in both structures. Indeed, the As-site doping energy of the WZ structure is several orders of magnitude higher than that of Ga sites, allowing a lower doping compensation effect. This work provides useful information for doping control and hence designing crystal-phase devices.
|
|
| 8. |
- Li, Ying, et al.
(författare)
-
Deep knowledge distillation: A self-mutual learning framework for traffic prediction
- 2024
-
Ingår i: Expert Systems with Applications. - 0957-4174. ; 252
-
Tidskriftsartikel (refereegranskat)abstract
- Traffic flow prediction in spatio-temporal networks is a crucial aspect of Intelligent Transportation Systems (ITS). Existing traffic flow forecasting methods, particularly those utilizing graph neural networks, encounter limitations. When processing large-scale graph data, the depth of these models can restrict their ability to effectively capture complex relationships and patterns. Additionally, these methods often focus mainly on local neighborhood information, which can limit their capability to recognize and analyze global relationships and patterns within the graph data. Therefore, we proposed a deep knowledge distillation model, tailored to effectively capture spatio-temporal patterns in traffic flow prediction. This model incorporates a bidirectional random walk process on a directed graph, enabling it to effectively capture both spatial and temporal dependencies. Utilizing a blend of mutual learning and self-distillation, our approach enhances the detection of spatio-temporal relationships within traffic data and improves the feature perception ability at both local and global levels. We tested our model on two real-world datasets, achieving notable improvements in prediction accuracy, especially for predictions within a one-hour timeframe. In comparison to the baseline model, our proposed model achieved accuracy improvements of 0.19 and 0.18 on the respective datasets. These results highlight the success of using mutual learning and self-distillation to transfer knowledge effectively within and between models and to improve the model's capability in identifying and extracting features.
|
|
| 9. |
- Liang, Zuozhong, et al.
(författare)
-
Novel insight into the epitaxial growth mechanism of six-fold symmetrical beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams and their water oxidation activity
- 2018
-
Ingår i: Electrochimica Acta. - : Elsevier BV. - 0013-4686 .- 1873-3859. ; 271, s. 526-536
-
Tidskriftsartikel (refereegranskat)abstract
- The six-fold symmetry widely presents in both natural and artificial architectures. Understanding the growth mechanism of six-fold symmetrical materials is of fundamental interest and significance. Herein, we report the formation process of beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams with a six-fold symmetrical arrangement. Our results demonstrate that hexagonal beta-Co(OH)(2) plates are first formed under the reaction condition. These hexagonal plates then act as templates for the growth of Co(OH)F nanorods. The intermediate material is therefore composed of plate-like beta-Co(OH)(2) hexagonal cores appended with six rod-like Co(OH)F branches, giving the beta-Co(OH)(2)/Co(OH)F hybrid. After prolonged reaction, the beta-Co(OH)(2) hexagons can be completely converted, leading to authentic six-branched Co(OH)F nanorods as the final product. Consequently, for both intermediate and final materials, the Co(OH)F nanorods are arranged with a six-fold symmetry. Importantly, these Co(OH)F nanorods grow along beta-Co(OH)(2) hexagon edges as lateral branches instead of perpendicular to hexagons. This uncommon epitaxial growth mechanism is considered to be a result of the matching between the b-axis of Co(OH)F crystals and the a-axis of beta-Co(OH)(2) crystals, which is beneficial for the electrocatalysis. The beta-Co(OH)(2)/Co(OH)F hierarchical hexagrams show enhanced water oxidation activity compared to the pure beta-Co(OH)(2) and Co(OH)F.
|
|
| 10. |
- Liu, Yang, 1991, et al.
(författare)
-
DeepTSP: Deep traffic state prediction model based on large-scale empirical data
- 2021
-
Ingår i: Communications in Transportation Research. - : Elsevier BV. - 2772-4247. ; 1
-
Tidskriftsartikel (refereegranskat)abstract
- Real-time traffic state (e.g., speed) prediction is an essential component for traffic control and management in an urban road network. How to build an effective large-scale traffic state prediction system is a challenging but highly valuable problem. This study focuses on the construction of an effective solution designed for spatio-temporal data to predict the traffic state of large-scale traffic systems. In this study, we first summarize the three challenges faced by large-scale traffic state prediction, i.e., scale, granularity, and sparsity. Based on the domain knowledge of traffic engineering, the propagation of traffic states along the road network is theoretically analyzed, which are elaborated in aspects of the temporal and spatial propagation of traffic state, traffic state experience replay, and multi-source data fusion. A deep learning architecture, termed as Deep Traffic State Prediction (DeepTSP), is therefore proposed to address the current challenges in traffic state prediction. Experiments demonstrate that the proposed DeepTSP model can effectively predict large-scale traffic states.
|
|
