| 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. |
- Yen, Ying-Tzu, et al.
(author)
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Prominent Enhancement of Cisplatin Efficacy with Optimized Methoxy Poly(ethylene glycol)-Polycaprolactone Block Copolymeric Nanoparticles
- 2020
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In: Journal of Biomedical Nanotechnology. - : AMER SCIENTIFIC PUBLISHERS. - 1550-7033 .- 1550-7041. ; 16:3, s. 335-343
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Journal article (peer-reviewed)abstract
- Chemotherapy has been one of the major standard treatments for a variety of cancers. cis-Dichlorodiamminoplatiunum(II) (cisplatin, CDDP), as one of the anticancer agents, demonstrated excellent efficacy against tumor and has been an indispensable component in chemotherapy, chemoradiation, chemo-molecular targeted therapy and chemo-immunotherapy. However, its therapeutic concentration was limited since its inevitable toxicity. Previously, we have constructed CDDP-loaded nanoparticles (NPs) with mixture of poly(ethyleneglycol)-polycaprolactone (PEG-PCL) and polycarprolactone (HO-PCL) by a facile method. The most optimal proportion of the two copolymers was selected through a series of physical, chemical, cytological and histological evaluations. In the present study, we explored the mechanisms of NPs and observed the in vivo antitumor effect after administrating CDDP-loaded PEG-PCL NPs. Positron emission tomography as well as computed tomography (PET/CT) were adopted for detecting tumoral metabolic activity. Images from fluorescence microscope revealed superior cellular uptake of CDDP-loaded NPs with rhodamine B aggregated intracellularly in cancer cells. Similar apoptotic rates between free CDDP group and CDDP-loaded NPs group was measured by flow cytometry. Tumor volumes and murine weights confirmed the superiority of CDDP-loaded NPs in therapeutic efficacy as compared with free CDDP. Blood tests showed milder side effects in CDDP-loaded nanoparticle group. PET/CT images illustrated less uptake intensity of FDG in mice received CDDP-loaded NPs than free CDDP. Our results suggest that PEG-PCL/PCL NPs could be a promising antitumor drug carrier for CDDP delivery with solid efficacy and minor side effects.
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| 3. |
- Bao, Zijia, et al.
(author)
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A helical polypyrrole nanotube interwoven zeolitic imidazolate framework and its derivative as an oxygen electrocatalyst
- 2022
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In: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 58:80, s. 11288-11291
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Journal article (peer-reviewed)abstract
- A helical polypyrrole nanotube interwoven zeolitic imidazolate framework (ZIF) has been prepared for the first time. After pyrolysis, the helical carbon could act as highly active sites, while the 3D-connected nanoarchitecture contributed to fast charge transfer. The derived carbon material exhibits high activity for the ORR and good performance for a Zn–air battery.
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| 4. |
- Liu, Fangcen, et al.
(author)
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Biocompatible Nanoparticles as a Platform for Enhancing Antitumor Efficacy of Cisplatin-Tetradrine Combination
- 2021
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In: Nanoscale Research Letters. - : Springer. - 1931-7573 .- 1556-276X. ; 16:1
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Journal article (peer-reviewed)abstract
- Combination therapy has been a standard strategy in the clinical tumor treatment. We have demonstrated that combination of Tetradrine (Tet) and Cisplatin (CDDP) presented a marked synergistic anticancer activity, but inevitable side effects limit their therapeutic concentration. Considering the different physicochemical and pharmacokinetic properties of the two drugs, we loaded them into a nanovehicle together by the improved double emulsion method. The nanoparticles (NPs) were prepared from the mixture of poly(ethyleneglycol)-polycaprolactone (PEG-PCL) and polycarprolactone (HO-PCL), so CDDP and Tet can be located into the NPs simultaneously, resulting in low interfering effect and high stability. Images from fluorescence microscope revealed the cellular uptake of both hydrophilic and hydrophobic agents delivered by the NPs. In vitro studies on different tumor cell lines and tumor tissue revealed increased tumor inhibition and apoptosis rates. As to the in vivo studies, superior antitumor efficacy and reduced side effects were observed in the NPs group. Furthermore, (18)FDG-PET/CT imaging demonstrated that NPs reduced metabolic activities of tumors more prominently. Our results suggest that PEG-PCL block copolymeric NPs could be a promising carrier for combined chemotherapy with solid efficacy and minor side effects.
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| 5. |
- Wang, Xinyue, et al.
(author)
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Charge-Separated States Determined Photoinduced Electron Transfer Efficiency in a D-D-A System in an External Electric Field
- 2023
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In: Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455.
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Journal article (peer-reviewed)abstract
- Focusing on the photoinduced electron transfer properties of the D-D-A molecule ((TPA-TT)-BODIPY-C60) in an external electric field (Fext), the excited-state properties in which the double-donor molecule is excited to form three charge-separated states were simulated. The charge-Transfer processes of these three charge-separated states were investigated by considering the two donors as a whole ((TPA-TT-BODIPY)·+-C60·-) as a comparison object. The electronic coupling (VDA), reorganization energy (λ), and free energy (δG) of the different charge-separated states in Fext were calculated and simulated. The calculated results show that the λ of (TPA-TT-BODIPY)·+-C60·- ranges from 0.576 to 0.51 eV, and the calculated δG of exciton dissociation ranges from-1.402 to-1.143 eV, indicating that exciton dissociation occurs in the Marcus inverted region. In the range of Fext =-10 × 10-5 to 10 × 10-5 au, the trend of the charge-Transfer rate is gradually increasing, and the rate increase is mainly from the VDA and δG changes. Moreover, the rapid formation of the (TPA-TT)-BODIPY·+-C60·- charge-separated state and the formation of the long-lived (TPA-TT)·+-BODIPY-C60·- are indicated by the exciton dissociation rate. By studying the charge-Transfer parameters under different electric field directions, it is found that the regulation of electric field strength on the charge-Transfer rate is consistent. These results provide a feasible method for the rational design of a new type of electron transfer process with high efficiency of the D-D-A system.
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| 6. |
- Wang, Xinyue, et al.
(author)
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External electric field-dependent photoinduced charge transfer in non-fullerene organic solar cells
- 2023
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In: Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy. - : Elsevier BV. - 1386-1425. ; 284
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Journal article (peer-reviewed)abstract
- Based on Marcus theory, the photoinduced electron transfer properties of D-A type non-fullerene acceptor organic solar cells (OSCs) under the dependence of external electric field (Fext) were investigated. The research results shown that the charge transfer mode under different Fext intensities changes with certain regularity. Focusing on the important parameters (ΔG, λ, and VDA) that affect the charge transfer rate, it was found that both charge separation (|ΔGCS|>λ(1.3019 vs 0.8275 eV at Fext = 0) and charge recombiation (|ΔGCR|>λ, (1.9633 vs 0.8275 eV)) processes occur in the Marcus inverted region. The ΔGCS is relatively sensitive to Fext, and the calculated ΔGCS at different Fext intensities yields an increment of 0.0073 eV, which is also the main reason for the increase in the rate of charge separation. The ΔGCR ranges between −1.9633 and −1.9637 eV, is insensitive to Fext, and ΔGCR is significantly smaller than ΔGCS, which makes the charge recombination rate significantly smaller than the charge separation rate. For VDA, it is found that VDA will transition to a new level only when the Fext intensity reaches a certain intensity, which also enables to obtain a faster charge separation rate. By studying the charge transfer parameters in different polar solvents, it is found that polar solvents can indeed increase the charge transfer rate. To a certain extent, our results also demonstrate that the addition of Fext can further improve the performance of non-fullerene acceptor OSCs.
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| 7. |
- Cui, Xinyue, et al.
(author)
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Esthetic appearances of anatomic contour zirconia crowns made by additive wet deposition and subtractive dry milling : A self-controlled clinical trial
- 2020
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In: The Journal of prosthetic dentistry (Print). - : Elsevier BV. - 0022-3913 .- 1097-6841. ; 123:3, s. 442-448
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Journal article (peer-reviewed)abstract
- Statement of problem. Anatomic contour zirconia crowns are widely used in clinical dental practice because of their mechanical reliability and improved appearance. However, few studies have performed clinical evaluations of the esthetics of these crowns in terms of color and translucency gradient.Purpose. The purpose of this clinical trial was to compare the esthetic effect and color-matching behaviors of anatomic contour zirconia crowns manufactured with 3-dimensional (3D) gel deposition and dry milling methods.Material and methods. Twenty-seven premolar teeth of 27 participants received 2 identical anatomic contour zirconia crowns fabricated by additive 3D gel deposition or dry milling. Color differences (Delta E) between the crown and natural control teeth were measured by a dental shadematching device. Subjective color matching was rated by professionals using an extended visual rating scale for appearance match (EVRSAM) and by participants using a visual analog scale (VAS). Data were analyzed by using repeated measures ANOVA, the Bonferroni test, paired Student t test, Pearson chi-square test, and Wilcoxon test (alpha=.05).Results. Significant differences were found in SE between zirconia crown and core types (P<.05); however, there was no significant interaction between these factors (P>.05). The average SE of crowns made by wet deposition and dry milling were 2.45 +/- 1.60 and 4.55 +/- 1.54 (P<.05). The mean crown Delta E was significantly higher if a gold cast post-and-core was placed rather than a prefabricated fiber post and composite core (P<.05). Consistent with these findings, subjective color matching was significantly higher in the wet deposition group than in the dry milling group as rated by EVRSAM and VAS (P<.05).Conclusion. Anatomic contour zirconia crowns fabricated by additive wet deposition were better matched to adjacent teeth and had excellent esthetics in terms of color and translucency gradient.
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| 8. |
- Guo, Huijie, et al.
(author)
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Regulation of photoinduced charge transfer in all-small-molecule organic solar cells through the synergistic effect of external electric field and solvent
- 2024
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In: Journal of Luminescence. - 0022-2313. ; 268
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Journal article (peer-reviewed)abstract
- The donor (BTR-Cl) and acceptor (BTP-FCl-FCl) have well-defined small molecule properties and excellent repeatability, and they can form charge transfer complexes with a wide spectral absorption range. Using density functional theory (DFT), we simulate the photoinduced charge transfer of bulk-heterojunction (BHJ) organic solar cell (OSC) materials modulated by the external electric field (Fext) at the microscopic level. The excited-state properties, reorganization energy (λ), Gibbs free energy (ΔG), electron coupling matrix elements (VDA) and intermolecular charge transfer (ICT) rate dependent on Fext are systematically analyzed. The results manifest that Fext has apparent positive regulation on the charge separation rate (KCS), and VDA is the main factor affecting KCS. The synergistic effect of solvent and Fext on charge transfer process is further investigated. It is found that the charge transfer rate in solvent is lower than that in solvent-free conditions, and the charge transfer rate in chlorobenzene (CB) solvent does not change significantly under the control of Fext. At the same time, Fext has a positive effect on the charge transfer rate in tetrahydrofuran (THF) solvent. Considering the charge transfer rate under different solvents and Fext intensities, it is found that the solvent and Fext play an essential role in determining the KCS and charge recombination rate (KCR).
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| 9. |
- Kozielski, Frank, et al.
(author)
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Identification of fragments binding to SARS-CoV-2 nsp10 reveals ligand-binding sites in conserved interfaces between nsp10 and nsp14/nsp16
- 2021
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In: RSC Chemical Biology. - 2633-0679. ; 3:1, s. 44-55
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Journal article (peer-reviewed)abstract
- Since the emergence of SARS-CoV-2 in 2019, Covid-19 has developed into a serious threat to our health, social and economic systems. Although vaccines have been developed in a tour-de-force and are now increasingly available, repurposing of existing drugs has been less successful. There is a clear need to develop new drugs against SARS-CoV-2 that can also be used against future coronavirus infections. Non-structural protein 10 (nsp10) is a conserved stimulator of two enzymes crucial for viral replication, nsp14 and nsp16, exhibiting exoribonuclease and methyltransferase activities. Interfering with RNA proofreading or RNA cap formation represents intervention strategies to inhibit replication. We applied fragment-based screening using nano differential scanning fluorometry and X-ray crystallography to identify ligands targeting SARS-CoV-2 nsp10. We identified four fragments located in two distinct sites: one can be modelled to where it would be located in the nsp14–nsp10 complex interface and the other in the nsp16–nsp10 complex interface. Microscale thermophoresis (MST) experiments were used to quantify fragment affinities for nsp10. Additionally, we showed by MST that the interaction by nsp14 and 10 is weak and thereby that complex formation could be disrupted by small molecules. The fragments will serve as starting points for the development of more potent analogues using fragment growing techniques and structure-based drug design.
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| 10. |
- Shao, Yu, et al.
(author)
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Feasibility of Using Floor Vibration to Detect Human Falls
- 2021
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In: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 18:1
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Journal article (peer-reviewed)abstract
- With the increasing aging population in modern society, falls as well as fall-induced injuries in elderly people become one of the major public health problems. This study proposes a classification framework that uses floor vibrations to detect fall events as well as distinguish different fall postures. A scaled 3D-printed model with twelve fully adjustable joints that can simulate human body movement was built to generate human fall data. The mass proportion of a human body takes was carefully studied and was reflected in the model. Object drops, human falling tests were carried out and the vibration signature generated in the floor was recorded for analyses. Machine learning algorithms including K-means algorithm and K nearest neighbor algorithm were introduced in the classification process. Three classifiers (human walking versus human fall, human fall versus object drop, human falls from different postures) were developed in this study. Results showed that the three proposed classifiers can achieve the accuracy of 100, 85, and 91%. This paper developed a framework of using floor vibration to build the pattern recognition system in detecting human falls based on a machine learning approach.
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