REVIEW | doi:10.20944/preprints201803.0273.v1
Subject: Physical Sciences, Optics And Photonics Keywords: Quantitative phase microscopy; Digital holographic microscopy; lensless microscopy; resolution enhancement; space-bandwidth product
Online: 30 March 2018 (14:09:57 CEST)
Quantitative phase microscopy (QPM), a technique combining phase imaging and microscopy, enables visualization of the 3-D topography in reflective samples as well as the inner structure or refractive index distribution of transparent and translucent samples. However, as in conventional optical microscopy, QPM provides either a large field of view (FOV) or a high resolution but not both. Many approaches such as oblique illumination, structured illumination and speckle illumination have been proposed to improve the spatial resolution of phase microscopy by restricting other degrees of freedom (mostly time). Therefore, the space bandwidth product (SBP) of QPM becomes enlarged. This paper aims to provide an up-to-date review on the resolution enhancement approaches of QPM, discussing the pros and cons of each technique as well as the confusion on resolution definition claim on QPM and other coherent microscopy.
ARTICLE | doi:10.20944/preprints201908.0009.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: tea polyphenol; serum hormone; enzyme activity; immune function, enzyme-related genes
Online: 1 August 2019 (05:18:08 CEST)
The present study was conducted to evaluate the effects of dietary supplementation of tea polyphenol （TP） on serum hormone, serum enzyme activity, antioxidant-related and immune-related gene expression of laying hens under heat stress. A total of 288 Chinese yellow chicken (186 days old) were randomly distributed among two treatments, each of which included 6 replicates of 24 hens. Dietary treatments were that the basal diet was supplemented with 200 mg / kg tea polyphenol. The study lasted for 7 weeks, including 1 week of adaptation and 6 weeks of the formal test. The content of high-density lipoprotein cholesterol (HDL-C) and total protein (TP) in serum significantly decreased by dietary supplementation with tea polyphenol. Dietary tea polyphenol supplementation improved serum superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) enzyme activity and decreased serum malondialdehyde (MDA) content in treatments compared to the control. However, supplementation of tea polyphenol did not affect the activity of serum catalase (CAT). The results indicated that long-term feeding of tea polyphenols help to increase the amount of hormones (FSH, E2) associated with reproduction in laying hens and thus improve egg production. It also improved the immune function of laying hens in high temperature environments. Adding tea polyphenols to the diet can significantly increase the serum IgG, IgM content of the laying hens and can upregulate the IgA content. Dietary supplementation of tea polyphenols in the laying hens significantly increased the expression of antioxidant enzyme-related genes (SOD, CAT and GPX1) in the liver. Moreover, the addition of tea polyphenols significantly increased the expression of immune-related genes (Interferon-γ (INF-γ), Interleukin 2 (IL-2) and Interleukin 4 (IL-4)) in the spleen. It is concluded that addition of tea polyphenols has a positive effect on antioxidant activity and immune function of laying hens.
ARTICLE | doi:10.20944/preprints202310.0013.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: tumor multidrug resistance; P-glycoprotein; pyxinol amino acid ester derivatives; molecular docking; metabolomics
Online: 1 October 2023 (08:32:50 CEST)
(1) Background: The typical transporter protein, P-glycoprotein (P-gp), has been proven to be associated with multidrug resistance (MDR). Pyxinol and 24S-Pyxinol amino acid ester derivatives had been demonstrated to be promising P-gp inhibitors for reversal of tumor MDR in KBV cells, however, their roles in MDR reversal in other tumor-resistant cells are still unclear. (2) Methods: In the present study, we synthesized 40 amino acid ester derivatives of Pyxinol and 24S-Pyxinol. The MDR reversal effects of these derivatives were evaluated in A549/Tax, MCF-7/ADR, and HCT-8/VCR cells using the CCK-8 assay. Subsequently, western blot assay, intracellular Rhodamine123 (Rh123) accumulation assay and P-gp ATPase activity assay were utilized to investigate the effects of active compound on P-gp. Molecular docking was used to predict the possible binding patterns of active compound to P-gp. Moreover, based on UPLC-Q/TOF-MS cellular metabolomics technology to identify endogenous differential metabolites and metabolic pathways associated with tumor MDR effects of the active compound. (3) Results: The results of the CCK-8 assay showed that compounds 8, 14, 16, 17, 18, 23, 25, 34, 36, 37 exhibited strong MDR reversal effect in A549/Tax, MCF-7/ADR and HCT-8/VCR cells, which were screened by reversal fold (RF) greater than 5. Among them, 10 μM of derivative 37 (new compound) showed the outstanding activity (RF: 15.31) in reversing MDR in A549/Tax cells. Compound 37 could act as a substrate for P-gp and inhibit the efflux function of P-gp by competitively binding to the binding site of antitumor drugs. Meanwhile, the molecular docking results confirmed that compound 37 was identified to under-go high-affinity binding to the drug binding site of P-gp. In addition, 14 endogenous differential metabolites and 6 metabolic pathways involved closely associated with the reversal of tumor MDR effects of compound 37 were identified. (4) Conclusions: Overall, a new candidate compound 37 (24S-3-L-threonyl-Pyxinol) could be provided for reversing tumor MDR by this study.