Antioxidative Activities and Active Compounds of Extracts from Catalpa

In order to screen the Catalpa plant with high antioxidant activity and confirm the corresponding active fractions from Catalpa ovata G. Don, C. fargesii Bur., and C. bungei C. A. Mey., total flavonoid contents and antioxidant activities of the extracts/fractions of Catalpa plant leaves were determined. The determined total flavonoid content and antioxidant activity were used as assessment criteria. Those compounds with antioxidant activity were isolated with silica gel column chromatography and ODS column chromatography. Our results showed that the total flavonoid content in C. bungei C. A. Mey. (30.07 mg/g·DW) was the highest, followed by those in C. fargesii Bur. (25.55 mg/g·DW) and C. ovata G. Don (24.96 mg/g·DW). According to the determination results of total flavonoid content and antioxidant activity in 3 clones of leaves of C. bungei C. A. Mey., the total flavonoid content and antioxidant activity in crude extracts from C. bungei C. A. Mey. 6 (CA6) leaves were the highest. Moreover, the results showed that the total flavonoid content and antioxidant activities of ethyl acetate (EA) fraction in ethanol crude extracts in CA6 leaves were the highest, followed by n-butanol, petroleum ether (PE), and water fractions. Two flavonoid compounds with antioxidant activity were firstly isolated based on EA fraction. The two compounds were luteolin (1) and apigenin (2), respectively

Preparation and Recognition Properties of Molecularly Imprinted Nanofiber Membrane of Chrysin

The separation and extraction of chrysin from active ingredients of natural products are of great significance, but the existing separation and extraction methods have certain drawbacks. Here, chrysin molecularly imprinted nanofiber membranes (MINMs) were prepared by means of electrospinning using chrysin as a template and polyvinyl alcohol and natural renewable resource rosin ester as membrane materials, which were used for the separation of active components in the natural product. The MINM was examined using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The adsorption performance, adsorption kinetics, adsorption selectivity, and reusability of the MINM were investigated in static adsorption experiments. The analysis results show that the MINM was successfully prepared with good morphology and thermal stability. The MINM has a good adsorption capacity for chrysin, showing fast adsorption kinetics, and the maximum adsorption capacity was 127.5 mg·g−1, conforming to the Langmuir isotherm model and pseudo-second-order kinetic model. In addition, the MINM exhibited good selectivity and excellent reusability. Therefore, the MINM proposed in this paper is a promising material for the adsorption and separation of chrysin

Removing Calcium Ions from Remelt Syrup with Rosin-Based Macroporous Cationic Resin

Mineral ions (mainly calcium ions) from sugarcane juice can be trapped inside the heating tubes of evaporators and vacuum boiling pans, and calcium ions are precipitated. Consequently, sugar productivity and yield are negatively affected. Calcium ions can be removed from sugarcane juice using adsorption. This paper described the experimental condition for the batch adsorption performance of rosin-based macroporous cationic resins (RMCRs) for calcium ions. The kinetics of adsorption was defined by the pseudo-first-order model, and the isotherms of calcium ions followed the Freundlich isotherm model. The maximal monolayer adsorption capacity of calcium ions was 37.05 mg·g−1 at a resin dosage of 4 g·L−1, pH of 7.0, temperature of 75 °C, and contact time of 10 h. It appeared that the adsorption was spontaneous and endothermic based on the thermodynamic parameters. The removal rate of calcium ions in remelt syrup by RMCRs was 90.71%. Calcium ions were effectively removed from loaded RMCRs by 0.1 mol·L−1 of HCl, and the RMCRs could be recycled. The dynamic saturated adsorption capacity of RMCRs for calcium ions in remelt syrup was 37.90 mg·g−1. These results suggest that RMCRs are inexpensive and efficient adsorbents and have potential applications for removing calcium ions in remelt syrup

Assessing abnormal corneal endothelial cells from in vivo confocal microscopy images using a fully automated deep learning system

Abstract Background The goal of this study is to develop a fully automated segmentation and morphometric parameter estimation system for assessing abnormal corneal endothelial cells (CECs) from LASER in vivo confocal microscopy (IVCM) images. Methods First, we developed a fully automated deep learning system for assessing abnormal CECs using a previous development set composed of normal images and a newly constructed development set composed of abnormal images. Second, two testing sets, one with 169 normal images and the other with 211 abnormal images, were used to evaluate the clinical validity and effectiveness of the proposed system on LASER IVCM images with different corneal endothelial conditions, particularly on abnormal images. Third, the automatically calculated endothelial cell density (ECD) and the manually calculated ECD were compared using both the previous and proposed systems. Results The automated morphometric parameter estimations of the average number of cells, ECD, coefficient of variation in cell area and percentage of hexagonal cells were 257 cells, 2648 ± 511 cells/mm2, 32.18 ± 6.70% and 56.23 ± 8.69% for the normal CEC testing set and 83 cells, 1450 ± 656 cells/mm2, 34.87 ± 10.53% and 42.55 ± 20.64% for the abnormal CEC testing set. Furthermore, for the abnormal CEC testing set, Pearson’s correlation coefficient between the automatically and manually calculated ECDs was 0.9447; the 95% limits of agreement between the manually and automatically calculated ECDs were between 329.0 and − 579.5 (concordance correlation coefficient = 0.93). Conclusions This is the first report to count and analyze the morphology of abnormal CECs in LASER IVCM images using deep learning. Deep learning produces highly objective evaluation indicators for LASER IVCM corneal endothelium images and greatly expands the range of applications for LASER IVCM

Accumulation of glycolipids in wheat grain and their role in hardness during grain development

Grain hardness is an important parameter for wheat quality. To understand the role of glycolipids in the formation of grain hardness, the glycolipid contents in wholegrain wheat flour and the starch granule surfaces of oven-dried and freeze-dried hard and soft wheat grain were analyzed. Changes in endosperm structure and amyloplast membrane integrity during grain development were also examined by electron microscopy. The monogalactosyldigylcerol (MGDG) and digalactosyldigylcerol (DGDG) contents of the starch surface were significantly higher in soft wheat than in hard wheat, regardless of the drying method or developmental stage. Throughout grain development, MGDG content was significantly higher in the starch surface of freeze-dried hard wheat than in the starch surface of oven-dried hard wheat. In contrast, the MGDG content of the starch surface was significantly higher in freeze-dried soft grain at 14 and 35 days after anthesis. No significant difference was observed in puroindoline protein (PIN) accumulation in wholegrain flour from wheat that was dried using the two methods, whereas PIN accumulation on the starch surface of freeze-dried grain was lower than that on the starch surface of oven-dried grain. The gap between the amyloplast membrane and starch granules was larger in hard wheat than in soft wheat, as shown by transmission electron microscopy. For the same wheat cultivar, this gap was larger for oven-dried than for freeze-dried grain. The content of polar lipids in the starch surface was closely related to grain hardness, and the breakdown of the amyloplast membrane may determine the location of polar lipids on the starch surface. Keywords: Amyloplast membrane, Endosperm microstructure, Grain hardness, Polar lipid, Whea

Study of the Preparation and Properties of Chrysin Binary Functional Monomer Molecularly Imprinted Polymers

Chrysin is a natural bioactive molecule with various groups, and it has been a challenge to separate and enrich chrysin from natural products. Molecularly imprinted polymers have been widely used in the extraction of natural products, but the number and type of functional monomers limits the separation effect. The synergistic action of multiple functional monomers can improve the separation effect. In this paper, molecularly imprinted polymers (Bi-MIPs) were prepared using methacrylic acid and acrylamide as binary functional monomers for the separation and enrichment of chrysin. The Bi-MIPs were characterized using thermogravimetric analyzer (TGA), Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The performances of Bi-MIPs were assessed, which included adsorption isotherms, selective recognition and adsorption kinetics. The experimental results show that Bi-MIPs are shaped as a uniform sphere with an abundant pocket structure on its surface. The adsorption of chrysin on the Bi-MIPs followed a pseudo-second-order and adapted Langmuir–Freundlich isotherm models. The adsorption performance of the Bi-MIPs was determined at different temperatures, and the Bi-MIPs showed excellent adsorption performance at 30 °C. The initial decomposition temperature of the Bi-MIPs was 220 °C. After five times of adsorption and desorption, the adsorption performance of the Bi-MIPs decreased by only 7%. In contrast with single functional monomer molecularly imprinted polymers (Si-MIPs), the Bi-MIPs showed excellent specificity, with an imprinting factor of 1.54. The Bi-MIPs are promising materials in the separation and enrichment of chrysin for their high adsorption capacity, low cost and being environmentally friendly

Surface-Engineered Gold Nanoclusters for Stimulated Emission Depletion and Correlated Light and Electron Microscopy Imaging

Stimulated emission depletion (STED) nanoscopy is an emerging super-resolution imaging platform for the study of the cellular structure. Developing suitable fluorescent probes of small size, good photostability, and easy functionalization is still in demand. Herein, we introduce a new type of surface-engineered gold nanoclusters (Au NCs) that are ultrasmall (1.7 nm) and ultrabright (QY = 60%) for STED bioimaging. A rigid shell formed by L-arginine (L-Arg) and 6-aza-2thiothymine (ATT) on the Au NC surface enables not only its strong fluorescence in aqueous solution but also its easy chemical modification for specific biomolecule labeling. Au NCs show remarkable performance as STED nanoprobes, including high depletion efficiency, good photobleaching resistance, and low saturation intensity. Super-resolution imaging has been achieved with these Au NCs, and targeted nanoscopic imaging of cellular tubulin has been demonstrated. Moreover, the circular structure of lysosomes in live cells has been revealed. As a Au NC is also an ideal probe for electron microscopy, dual imaging of A beta 42 aggregates with the single labeling probe of Au NCs has been realized in correlative light and electron microscopy (CLEM). This work reports, for the first time, the application of Au NCs as a novel probe in STED and CLEM imaging. With their excellent properties, Au NCs show promising potential for nanoscale bioimaging

Anaplasma infection of Bactrian camels (Camelus bactrianus) and ticks in Xinjiang, China

Abstract Background To date, anaplasmosis has been reported to be a subclinical disease in Indian and Arabian one-humped camels (Camelus dromedarius) and llamas (Lama glama). However, no information on Anaplasma infection in two-humped Bactrian camels (Camelus bactrianus) in China has been published to date. The aim of this study was to investigate the prevalence of Anaplasma spp. in domestic Bactrian camels and ticks in Xinjiang, China. Findings A total of 382 ticks were collected from the Bactrian camels and from environmental sources. Of these, 84 were morphologically identified as belonging to the Rhipicephalus sanguineus group and genetically identified (12S rDNA, 16S rDNA and the cytochrome c oxidase 1 genes) as R. sanguineus group ticks (temporally designated as Rhipicephalus sp. Xinjiang). PCR testing showed that 7.2 % (20/279) of the camels harbored Anaplasma platys DNA. However, microscopic examination revealed no A. platys inclusions in blood smears from the camels. The PCR prevalence of A. platys DNA was 9.5 % (6/63) in Rhipicephalus sp. Xinjiang from the Bactrian camels and 14.3 % (3/21) in Rhipicephalus sp. Xinjiang from the vegetation. A. platys DNA was not detected by PCR in other tick species (Hyalomma asiaticum, Dermacentor niveus and Hyalomma dromedarii), and no other Anaplasma species were detected in these samples. Conclusions This is the first report of A. platys in Bactrian camels in Xinjiang, China. The moderate positivity observed indicates that these animals might be a natural host for this pathogen in China