| 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. |
- Aad, G., et al.
(author)
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- 2011
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swepub:Mat__t (peer-reviewed)
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| 3. |
- Arbi, Tarak, et al.
(author)
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Low-Complexity Blind PAPR Reduction for OFDM Systems With Rotated Constellations
- 2021
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In: IEEE transactions on broadcasting. - : IEEE. - 0018-9316 .- 1557-9611. ; 67:2, s. 491-499
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Journal article (peer-reviewed)abstract
- The high Peak-to-Average Power Ratio (PAPR) of Orthogonal Frequency Division Multiplexing (OFDM) signals leads to a serious system performance degradation. To work around this issue, several algorithms have been proposed in the literature to reduce the PAPR, but, they often suffer from multiple limitations; in particular, the main issue with interleaving techniques is the spectral efficiency loss, as the transmission of a Side Information (SI) is generally required. In contrast to previous works, this article proposes a blind interleaving technique for OFDM systems with signal space diversity. Indeed, with Rotated and Cyclically Q-Delayed (RCQD) constellations, the In-phase (I) and Quadrature (Q) components of constellations symbols are correlated, which allows the receiver to estimate the interleaver index without any SI. Moreover, to lower down the complexity burden at the receiver side, we first design a blind decoder based on the Minimum Mean Square Error (MMSE) criterion and we then propose a low complexity decoder for the Uniformly Projected RCQD (UP-RCQD) QAM, as this constellation has several interesting structural properties and achieves near optimum BER performance. Simulation results show that our proposal leads to a large PAPR reduction and to a near optimum BER performance that outperforms, over various channels, the solution currently used in DVB-T2. They also underline the good performance of the blind decoding performed with up to 98% of complexity reduction compared to the max-log Maximum Likelihood (ML) estimation.
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| 4. |
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| 5. |
- Chen, Geng, et al.
(author)
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Heisenberg-scaling measurement of the single-photon Kerr non-linearity using mixed states
- 2018
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In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 9
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Journal article (peer-reviewed)abstract
- Improving the precision of measurements is a significant scientific challenge. Previous works suggest that in a photon-coupling scenario the quantum fisher information shows a quantum-enhanced scaling of N-2, which in theory allows a better-than-classical scaling in practical measurements. In this work, utilizing mixed states with a large uncertainty and a post-selection of an additional pure system, we present a scheme to extract this amount of quantum fisher information and experimentally attain a practical Heisenberg scaling. We performed a measurement of a single-photon's Kerr non-linearity with a Heisenberg scaling, where an ultra-small Kerr phase of. 6 x 10(-8) rad was observed with a precision of similar or equal to 3.6 x 10(-10) rad. From the use of mixed states, the upper bound of quantum fisher information is improved to 2N(2). Moreover, by using an imaginary weak-value the scheme is robust to noise originating from the self-phase modulation.
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| 6. |
- Han, Bo-Yun, et al.
(author)
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A highly selective C-rhamnosyltransferase from Viola tricolor and insights into its mechanisms
- 2023
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In: Acta Pharmaceutica Sinica B. - : Elsevier. - 2211-3835 .- 2211-3843. ; 13:8, s. 3535-3544
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Journal article (peer-reviewed)abstract
- C-Glycosides are important natural products with various bioactivities. In plant biosynthetic pathways, the C-glycosylation step is usually catalyzed by C-glycosyltransferases (CGTs), and most of them prefer to accept uridine 5′-diphosphate glucose (UDP-Glc) as sugar donor. No CGTs favoring UDP-rhamnose (UDP-Rha) as sugar donor has been reported, thus far. Herein, we report the first selective C-rhamnosyltransferase VtCGTc from the medicinal plant Viola tricolor. VtCGTc could efficiently catalyze C-rhamnosylation of 2-hydroxynaringenin 3-C-glucoside, and exhibited high selectivity towards UDP-Rha. Mechanisms for the sugar donor selectivity of VtCGTc were investigated by molecular dynamics (MD) simulations and molecular mechanics with generalized Born and surface area solvation (MM/GBSA) binding free energy calculations. Val144 played a vital role in recognizing UDP-Rha, and the V144T mutant could efficiently utilize UDP-Glc. This work provides a new and efficient approach to prepare flavonoid C-rhamnosides such as violanthin and iso-violanthin.
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| 7. |
- Jones, Gregory T., et al.
(author)
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Meta-Analysis of Genome-Wide Association Studies for Abdominal Aortic Aneurysm Identifies Four New Disease-Specific Risk Loci
- 2017
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In: Circulation Research. - 0009-7330 .- 1524-4571. ; 120:2, s. 341-
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Journal article (peer-reviewed)abstract
- Rationale: Abdominal aortic aneurysm (AAA) is a complex disease with both genetic and environmental risk factors. Together, 6 previously identified risk loci only explain a small proportion of the heritability of AAA. Objective: To identify additional AAA risk loci using data from all available genome-wide association studies. Methods and Results: Through a meta-analysis of 6 genome-wide association study data sets and a validation study totaling 10 204 cases and 107 766 controls, we identified 4 new AAA risk loci: 1q32.3 (SMYD2), 13q12.11 (LINC00540), 20q13.12 (near PCIF1/MMP9/ZNF335), and 21q22.2 (ERG). In various database searches, we observed no new associations between the lead AAA single nucleotide polymorphisms and coronary artery disease, blood pressure, lipids, or diabetes mellitus. Network analyses identified ERG, IL6R, and LDLR as modifiers of MMP9, with a direct interaction between ERG and MMP9. Conclusions: The 4 new risk loci for AAA seem to be specific for AAA compared with other cardiovascular diseases and related traits suggesting that traditional cardiovascular risk factor management may only have limited value in preventing the progression of aneurysmal disease.
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| 8. |
- Shi, Yu-Sheng, et al.
(author)
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Limonoids from Citrus : Chemistry, anti-tumor potential, and other bioactivities
- 2020
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In: Journal of Functional Foods. - : ELSEVIER. - 1756-4646 .- 2214-9414. ; 75
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Journal article (peer-reviewed)abstract
- Citrus limonoids are tetranortriterpenoids compounds mainly found in oranges, lemons, grapefruits, and other fruits of Citrus. They are proved to be the leading cause of bitterness in Citrus fruits and are mainly consumed for therapeutic purposes and as food. Numerous studies have focused on Citrus limonoids and intend to develop new chemotherapeutic or complementary medicine in recent years. Citrus limonoids showed various bioactivities such as anti-tumor, antioxidative, anti-inflammatory, anti-neurological diseases, immunomodulatory, anti -insect, anti-bacteria, antiviral activities, etc. This review summarized limonoids from Citrus to date, along with their chemical structures and biological activities with a particular focus on their anti-tumor potential.
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| 9. |
- Wang, Hao-Tian, et al.
(author)
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Insights into the missing apiosylation step in flavonoid apiosides biosynthesis of Leguminosae plants
- 2023
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In: Nature Communications. - : Springer Nature. - 2041-1723. ; 14:1
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Journal article (peer-reviewed)abstract
- Apiose is a natural pentose containing an unusual branched-chain structure. Apiosides are bioactive natural products widely present in the plant kingdom. However, little is known on the key apiosylation reaction in the biosynthetic pathways of apiosides. In this work, we discover an apiosyltransferase GuApiGT from Glycyrrhiza uralensis. GuApiGT could efficiently catalyze 2″-O-apiosylation of flavonoid glycosides, and exhibits strict selectivity towards UDP-apiose. We further solve the crystal structure of GuApiGT, determine a key sugar-binding motif (RLGSDH) through structural analysis and theoretical calculations, and obtain mutants with altered sugar selectivity through protein engineering. Moreover, we discover 121 candidate apiosyltransferase genes from Leguminosae plants, and identify the functions of 4 enzymes. Finally, we introduce GuApiGT and its upstream genes into Nicotiana benthamiana, and complete de novo biosynthesis of a series of flavonoid apiosides. This work reports an efficient phenolic apiosyltransferase, and reveals mechanisms for its sugar donor selectivity.
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| 10. |
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