| 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. |
- 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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| 3. |
- Liu, Shaohui, et al.
(författare)
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Data-Driven Controlled Synthesis of Oriented Quasi-Spherical CsPbBr3 Perovskite Materials
- 2024
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Ingår i: Angewandte Chemie International Edition. - : WILEY-V C H VERLAG GMBH. - 1433-7851 .- 1521-3773. ; 63:14
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Tidskriftsartikel (refereegranskat)abstract
- Controlled synthesis of lead-halide perovskite crystals is challenging yet attractive because of the pivotal role played by the crystal structure and growth conditions in regulating their properties. This study introduces data-driven strategies for the controlled synthesis of oriented quasi-spherical CsPbBr3, alongside an investigation into the synthesis mechanism. High-throughput rapid characterization of absorption spectra and color under ultraviolet illumination was conducted using 23 possible ligands for the synthesis of CsPbBr3 crystals. The links between the absorption spectra slope (difference in the absorbance at 400 nm and 450 nm divided by a wavelength interval of 50 nm) and crystal size were determined through statistical analysis of more than 100 related publications. Big data analysis and machine learning were employed to investigate a total of 688 absorption spectra and 652 color values, revealing correlations between synthesis parameters and properties. Ex situ characterization confirmed successful synthesis of oriented quasi-spherical CsPbBr3 perovskites using polyvinylpyrrolidone and Acacia. Density functional theory calculations highlighted strong adsorption of Acacia on the (110) facet of CsPbBr3. Optical properties of the oriented quasi-spherical perovskites prepared with these data-driven strategies were significantly improved. This study demonstrates that data-driven controlled synthesis facilitates morphology-controlled perovskites with excellent optical properties.
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| 4. |
- Shen, Sirui, et al.
(författare)
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A Hierarchical Parallel Discrete Gaussian Sampler for Lattice-Based Cryptography
- 2022
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Ingår i: 2022 IEEE INTERNATIONAL SYMPOSIUM ON CIRCUITS AND SYSTEMS (ISCAS 22). - : Institute of Electrical and Electronics Engineers (IEEE). ; , s. 1729-1733
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Konferensbidrag (refereegranskat)abstract
- Discrete Gaussian sampling is one of the important components in lattice-based cryptosystems which are promising candidates for post-quantum cryptographic algorithms. For sufficient security and satisfactory performance, the Knuth-Yao algorithm is an efficient way to implement discrete Gaussian samplers. Nevertheless, most polynomials in lattice-based cryptography have 256 coefficients or more, which suffers from long latency to complete the sample generation. In this paper, the first parallel discrete Gaussian sampler with hierarchical structure is proposed, while keeping statistical distance to the actual distribution. Based on the imbalanced visiting frequency of the probability matrix, a three-stage generation strategy is adopted with hierarchical bit search units (BSUs) that can greatly reduce area consumption of the repeated costly lookup tables. Besides the architecture improvement, a lowest-set-bit scanning scheme is introduced to BSUs. Moreover, the parallelism of our design provides obfuscation ability against side-channel attacks (SCAs). A practical hardware implementation of discrete Gaussian distributions with sigma = 3.33 on the Xilinx Virtex-5 XC5VLX30 FPGA device spends 26.12 ns on average to generate 256 samples, consuming 994 slices. Results have verified its advantages of area efficiency over the state-of-the-arts (SOAs).
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| 5. |
- Song, Wenqing, et al.
(författare)
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Heterogeneous Reconfigurable Accelerator for Homomorphic Evaluation on Encrypted Data
- 2024
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Ingår i: IEEE Access. - : Institute of Electrical and Electronics Engineers (IEEE). - 2169-3536. ; 12, s. 11850-11864
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Tidskriftsartikel (refereegranskat)abstract
- Homomorphic encryption (HE) enables third -party servers to perform computations on encrypted user data while preserving privacy. Although conceptually attractive, the speed of software implementations of HE is almost impractical. To address this challenge, various domain -specific architectures have been proposed to accelerate homomorphic evaluation, but efficiency remains a bottleneck. In this paper, we propose a homomorphic evaluation accelerator with heterogeneous reconfigurable modular computing units (RCUs) for the Brakerski/Fan-Vercauteren (BFV) scheme. RCUs leverage operator abstraction to efficiently perform basic sub -operations of homomorphic evaluation such as residue number system (RNS) conversion, number theoretic transform (NTT), and other modular computations. By combining these sub -operations, complex homomorphic evaluation operations like multiplication, rotation, and addition are efficiently executed. To address the high demand for data access and improve memory efficiency, we design a coordinate -based address encoding strategy that enables in -place and conflict -free data access. Furthermore, specific optimizations are performed on the core sub -operations such as NTT and automorphism. The proposed architecture is implemented on Xilinx Virtex-7 and UltraScale+ FPGA platforms and evaluated for polynomials of length 4096. Compared to state-of-the-art accelerators with the same parameter set, our accelerator achieves the following advantages: 1) 2.04x to 3.33x reduction in the area -time product (ATP) for the key sub -operation NTT, 2) 1.08x to 7.42x reduction in latency for homomorphic multiplication with higher area efficiency, and 3) support for a wider range of homomorphic evaluation operations, including rotation, compared to other BFV-based accelerators.
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| 6. |
- Wang, Xinyu, et al.
(författare)
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A hybrid molecular sensitizer for triplet fusion upconversion
- 2021
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Ingår i: Chemical Engineering Journal. - : Elsevier. - 1385-8947 .- 1873-3212. ; 426
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Tidskriftsartikel (refereegranskat)abstract
- Triplet fusion upconversion is useful for a broad spectrum of applications ranging from solar cells, photoredox catalysis, to biophotonics applications, especially in the near-infrared (NIR, >700 nm) range. This upconverting system typically demands efficient conversion of spin-singlet harvested energy through intersystem crossing to spin-triplet states, accessible only in rare metallic-coordinating macrocycle compounds or heavy-metal-containing semiconductor quantum dots for triplet sensitization. Herein, we describe an organic–inorganic system for NIR-to-visible triplet fusion upconversion, interfacing commonly-seen, non-metallic, infrared dyes (IR806, IR780, indyocynine green, and CarCl) and lanthanide nanocrystal (sodium ytterbium fluoride) as a hybrid molecular sensitizer, which extracts molecular spin-singlet energy to nanocrystal-enriched ytterbium dopants at 48% efficiency (IR806, photoexciation at 808 nm). Moreover, ytterbium sub-lattice energy migration increases the interaction possibility between the nanocrystal and the freely-diffusing rubrenes in solution, resulting in 24-fold (IR806) to 1740-fold (indocyanine green) upconversion (600 nm) increase, depending on the IR dye type, as compared to the one without ytterbium nanotransducers. Ab initio quantum chemistry calculations identify enhanced spin-orbital coupling in the ytterbium-IR806 complex and high energy transfer rate in the ytterbium-rubrene interaction (1010 s−1). Employing inorganic lanthanide nanocrystals as nanotransducers unleashes the potential use of non-metallic infrared organic dyes for triplet fusion upconversion.
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| 7. |
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| 8. |
- Zhou, Weibin, et al.
(författare)
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Targeting VEGF-A/VEGFR2 Y949 Signaling-Mediated Vascular Permeability Alleviates Hypoxic Pulmonary Hypertension
- 2022
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Ingår i: Circulation. - : Lippincott Williams & Wilkins. - 0009-7322 .- 1524-4539. ; 146:24, s. 1855-1881
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Tidskriftsartikel (refereegranskat)abstract
- Background:Pulmonary hypertension (PH) is associated with increased expression of VEGF-A (vascular endothelial growth factor A) and its receptor, VEGFR2 (vascular endothelial growth factor 2), but whether and how activation of VEGF-A signal participates in the pathogenesis of PH is unclear. Methods:VEGF-A/VEGFR2 signal activation and VEGFR2 Y949-dependent vascular leak were investigated in lung samples from patients with PH and mice exposed to hypoxia. To study their mechanistic roles in hypoxic PH, we examined right ventricle systolic pressure, right ventricular hypertrophy, and pulmonary vasculopathy in mutant mice carrying knock-in of phenylalanine that replaced the tyrosine at residual 949 of VEGFR2 (Vefgr2(Y949F)) and mice with conditional endothelial deletion of Vegfr2 after chronic hypoxia exposure. Results:We show that PH leads to excessive pulmonary vascular leak in both patients and hypoxic mice, and this is because of an overactivated VEGF-A/VEGFR2 Y949 signaling axis. In the context of hypoxic PH, activation of Yes1 and c-Src and subsequent VE-cadherin phosphorylation in endothelial cells are involved in VEGFR2 Y949-induced vascular permeability. Abolishing VEGFR2 Y949 signaling by Vefgr2(Y949F) point mutation was sufficient to prevent pulmonary vascular permeability and inhibit macrophage infiltration and Rac1 activation in smooth muscle cells under hypoxia exposure, thereby leading to alleviated PH manifestations, including muscularization of distal pulmonary arterioles, elevated right ventricle systolic pressure, and right ventricular hypertrophy. It is important that we found that VEGFR2 Y949 signaling in myeloid cells including macrophages was trivial and dispensable for hypoxia-induced vascular abnormalities and PH. In contrast with selective blockage of VEGFR2 Y949 signaling, disruption of the entire VEGFR2 signaling by conditional endothelial deletion of Vegfr2 promotes the development of PH. Conclusions:Our results support the notion that VEGF-A/VEGFR2 Y949-dependent vascular permeability is an important determinant in the pathogenesis of PH and might serve as an attractive therapeutic target pathway for this disease.
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| 9. |
- Cai, Weidong, et al.
(författare)
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Multicolor light emission and multifunctional applications in double perovskite-Cs 2 NaInCl 6 by Cu + /Sb 3+co-doping
- 2024
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Ingår i: Chemical Engineering Journal. - : ELSEVIER SCIENCE SA. - 1385-8947 .- 1873-3212. ; 489
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Tidskriftsartikel (refereegranskat)abstract
- Halide double perovskites managed by metal doping approach can exhibit dual emission colors, which have been considered as promising multicolor luminescent materials. However, an independent and stable emission at yellow region is missing owing to limited doping candidates, hindering the further commercialization of multicolor luminescence applications in double perovskites. In this work, we successfully obtain stable multicolor emission with PLQE (photoluminescence quantum yield) as high as 78% through developing the CuI doping strategy in Sb-Cs2NaInCl6. By introducing a high CuI feed ratio in airtight autoclave to compete the oxidization effect, the oxidization of CuI into CuII (detrimental factor for high PLQE due to serious quenching effect) is largely suppressed. With changing the CuI feed ratio, at least four distinct emission colors ranging from blue, purple, pink to yellow can be realized via changing the excitation wavelength. Depending on tunable multicolor emission, we further demonstrate the promise of our co-doped double perovskites in anti-counterfeiting technology and multicolor lighting devices. Our results open the way for enriching the optical applications of double perovskites based on multicolor emission.
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| 10. |
- Chen, Xinyu, et al.
(författare)
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Variations in electrical impedance and phase angle among seedlings of Pinus densata and parental species in Pinus tabuliformis habitat environment
- 2015
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Ingår i: Journal of Forestry Research. - : Northeast Forestry University. - 1007-662X .- 1993-0607. ; 26:3, s. 777-783
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Tidskriftsartikel (refereegranskat)abstract
- Electrical impedance (EI) and phase angle (PHI) parameters in AC impedance spectroscopy are important electrical parameters in the study of medical pathology. However, little is known about their application in variation and genetic relationship studies of forest trees. In order to test whether impedance parameters could be used in genetic relationship analysis among conifer species, EI and PHI were measured in a seedling experiment test composed of Pinus tabuliformis, Pinus yunnanensis, and Pinus densata in a habitat of Pinus tabuliformis. The results showed that variations in both EI and PHI among species were significant in different electric frequencies, and the EI and PHI values measured in the two populations of P. densata were between the two parental species, P. yunnanensis and P. tabuliformis. These results show that these two impedance parameters could reflect the genetic relationship among pine species. This was the first time using the two AC impedance spectroscopy parameters to test the genetic relationship analysis between tree species, and would be a hopeful novel reference methodology for future studies in evolution and genetic variation of tree species.
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