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- 2019
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Journal article (peer-reviewed)
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| 2. |
- 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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| 3. |
- Gao, Tao, et al.
(author)
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Pdx1 Maintains beta Cell Identity and Function by Repressing an alpha Cell Program
- 2014
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In: Cell Metabolism. - : Elsevier BV. - 1550-4131 .- 1932-7420. ; 19:2, s. 259-271
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Journal article (peer-reviewed)abstract
- Pdx1 is a homeobox-containing transcription factor that plays a key role in pancreatic development and adult beta cell function. In this study, we traced the fate of adult beta cells after Pdx1 deletion. As expected, beta-cell-specific removal of Pdx1 resulted in severe hyperglycemia within days. Surprisingly, a large fraction of Pdx1-deleted cells rapidly acquired ultrastructural and physiological features of a cells, indicating that a robust cellular reprogramming had occurred. Reprogrammed cells exhibited a global transcriptional shift that included derepression of the alpha cell transcription factor MafB, resulting in a transcriptional profile that closely resembled that of alpha cells. These findings indicate that Pdx1 acts as a master regulator of beta cell fate by simultaneously activating genes essential for beta cell identity and repressing those associated with alpha cell identity. We discuss the significance of these findings in the context of the emerging notion that loss of beta cell identity contributes to the pathogenesis of type 2 diabetes.
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| 4. |
- Hu, Jiwen, et al.
(author)
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Rapid detection of mercury (II) ions and water content by a new rhodamine B-based fluorescent chemosensor
- 2020
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In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1386-1425 .- 1873-3557. ; 241
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Journal article (peer-reviewed)abstract
- A rhodamine B-based sensor (RS) was designed and synthesized by a combination of the spirolacton rhodamine B (fluorophore) and multidentate chelates (ionophore) with high affinity towards Hg2+. In the presence of Hg2+, the resulting red-orange fluorescence (under UV light) and naked eye red color of IDS are supposed to be used for quantitative and qualitative measurement of Hg2+. Further fluorescent titration and analysis demonstrate that RS can selectively detect Hg2+ within 1 s with a low limit of detection (LOD) of 16 nM in acetonitrile media, meanwhile, the association constant (K-a) was calculated to be 0.32 x 10(5) M-1. More importantly, the resultant complex (RSHg) of RS and Hg2+ has also been successfully applied to detect limited water content in acetonitrile solution. (C) 2020 Published by Elsevier B.V.
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| 5. |
- Hu, Jiwen, et al.
(author)
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Ratiometric fluorogenic determination of endogenous hypochlorous acid in living cells
- 2019
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In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy. - : PERGAMON-ELSEVIER SCIENCE LTD. - 1386-1425 .- 1873-3557. ; 219, s. 232-239
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Journal article (peer-reviewed)abstract
- Hypochlorous acid (HClO) is one of the most important ROS (reactive oxygen species) and common pollutant in tap-water. However, the determination of HClO with fast response and high sensitivity/selectivity is still an urgent demanding. Here we fabricated a ratiometric fluorescent probe RC based on TBET (through-bond energy transfer) on the platform of coumarin and rhodamine with the thiosemicarbazide group as the linker. This probe could display the characteristic fluorescence emission of coumarin. Upon addition of HClO, the linker was reacted into an oxadiazole, resulting in the opening of spiro-ring of rhodamine. The resultant then gives ratiometric fluorogenic changes. The probe exhibits fast response and high selectivity and sensitivity towards HClO with a low limit of detection (similar to 140 nM). Eventually, RC is successfully applicated for determining spiked HClO in water samples and imaging endogenous HClO in living cells. (C) 2019 Published by Elsevier B.V.
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| 6. |
- Hu, Jiwen, 1986-, et al.
(author)
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Selective detections of Hg2+ and F- by using tailor-made fluorogenic probes
- 2018
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In: Sensors and actuators. B, Chemical. - : Elsevier. - 0925-4005 .- 1873-3077. ; 269, s. 368-376
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Journal article (peer-reviewed)abstract
- By ingeniously using a (imino)coumarin-precursor, three reactive fluorogenic probes of MP, FP, and FMP have been fabricated in a single facile synthetic route. MP and FP are able to respectively act as selective "turn-on" fluorescent probes for detecting Hg2+ and F- in buffer solution via specific analyte-induced reactions. Linear ranges for the detection of Hg2+ and F- are 0-10 mu M and 0-100 mu M with the limits of detection (LODs) of 4.0 x 10(-8) M and 1.14 x 10(-6) M (3 delta/slope), respectively. FMP is able to work as a molecular "AND" logic gate-based fluorogenic probe for monitoring the coexistence of Hg2+ and F- via a multistep reaction cascade. The analytes-induced sensing mechanisms have been determined by using high-performance liquid chromatography analysis (HPLC). In addition, three probes show negligible toxicity under the experimental conditions, and are successfully used for monitoring Hg2+ and F- in living cells with good cell permeability. The success of the work demonstrates that ingenious utility of specific analyte-induced reactions and conventional concepts on the appropriate molecular scaffold can definitely deliver tailor-made probes for various intended sensing purposes. (C) 2018 Published by Elsevier B.V.
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| 7. |
- Huang, Xin, 1982-, et al.
(author)
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Sensor Aided Authentication
- 2010
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In: Communications in Computer and Information Science Volume 76 CCIS, 2010. - Berlin, Heidelberg : Springer. - 3642133649 - 9783642133640 ; , s. 265-277
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Conference paper (peer-reviewed)abstract
- The sharing of sensor data globally becomes possible by the development of wireless sensor network, cloud computing, and other related technologies. These new trends can also benefit information security. In this paper, the sensor data is involved in the authentication procedure which is one main component of security systems. Sensor aided password is proposed. In addition, the architecture for sensor aided authentication corresponding to the simple authentication scenario is also designed. Sensor data aided password generation and utilization bring convenience to users without weakening the password strength.
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| 8. |
- Lin, Dongxu, et al.
(author)
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Vapor Deposited Pure alpha-FAPbI(3) Perovskite Solar Cell via Moisture-Induced Phase Transition Strategy
- 2022
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In: Advanced Functional Materials. - : WILEY-V C H VERLAG GMBH. - 1616-301X .- 1616-3028. ; 32:48
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Journal article (peer-reviewed)abstract
- To fabricate stable neat FAPbI(3) perovskite with a pure alpha-phase (pure alpha-FAPbI(3)) is important in the field of photovoltaic commercialization because of its better bandgap than its alloying counterpart with cesium (Cs) or methylammonium (MA) cations. In this work, the first vapor deposited pure alpha-FAPbI(3) thin film solar cell with a power conversion efficiency (PCE) over 20% is achieved by regulating the phase transition process. It is found that under high humidity conditions, a fast phase transition between high-purity alpha- and delta-phase FAPbI(3) can be realized. Moreover, theoretical calculations interestingly reveal a phase transition shortcut induced by the abnormal volume contraction that is ascribed to the formation of double hydrogen bonds at a certain H2O concentration. Therefore, a high-humidity post-treatment strategy is proposed to fabricate alpha-FAPbI(3) solar cells with a champion PCE of 20.19% (0.1 cm(2)) and 18.91% (1 cm(2)), which is currently the highest recorded value in vapor deposited pure alpha-FAPbI(3) perovskite solar cells. This study helps to redefine the effect of a water molecule on FAPbI(3) solar cells. In addition, the demonstrated scaling-up possibility provides another perspective for fabricating uniform high-performance pure alpha-FAPbI(3) perovskite solar cells.
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| 9. |
- Lin, Jiajie, et al.
(author)
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Wafer-scale heterogeneous integration InP on trenched Si with a bubble-free interface
- 2020
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In: APL Materials. - : AIP Publishing. - 2166-532X. ; 8:5
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Journal article (peer-reviewed)abstract
- Heterogeneous integration of compound semiconductors on a Si platform leads to advanced device applications in the field of Si photonics and high frequency electronics. However, the unavoidable bubbles formed at the bonding interface are detrimental for achieving a high yield of dissimilar semiconductor integration by the direct wafer bonding technology. In this work, lateral outgassing surface trenches (LOTs) are introduced to efficiently inhibit the bubbles. It is found that the chemical reactions in InP-Si bonding are similar to those in Si-Si bonding, and the generated gas can escape via the LOTs. The outgassing efficiency is dominated by LOTs' spacing, and moreover, the relationship between bubble formation and the LOT's structure is well described by a thermodynamic model. With the method explored in this work, a 2-in. bubble-free crystalline InP thin film integrated on the Si substrate with LOTs is obtained by the ion-slicing and wafer bonding technology. The quantum well active region grown on this Si-based InP film shows a superior photoemission efficiency, and it is found to be 65% as compared to its bulk counterpart.
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| 10. |
- Wu, Bo, et al.
(author)
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Strong self-trapping by deformation potential limits photovoltaic performance in bismuth double perovskite
- 2021
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In: Science Advances. - : American Association for the Advancement of Science. - 2375-2548. ; 7:8
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Journal article (peer-reviewed)abstract
- Bismuth-based double perovskite Cs2AgBiBr6 is regarded as a potential candidate for low-toxicity, high-stability perovskite solar cells. However, its performance is far from satisfactory. Albeit being an indirect bandgap semiconductor, we observe bright emission with large bimolecular recombination coefficient (reaching 4.5 +/- 0.1 x 10(-11) cm(3) s(-1)) and low charge carrier mobility (around 0.05 cm(2) s(-1) V-1). Besides intermediate Frohlich couplings present in both Pb-based perovskites and Cs2AgBiBr6, we uncover evidence of strong deformation potential by acoustic phonons in the latter through transient reflection, time-resolved terahertz measurements, and density functional theory calculations. The Frohlich and deformation potentials synergistically lead to ultrafast self-trapping of free carriers forming polarons highly localized on a few units of the lattice within a few picoseconds, which also breaks down the electronic band picture, leading to efficient radiative recombination. The strong self-trapping in Cs2AgBiBr6 could impose intrinsic limitations for its application in photovoltaics.
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