scholarly journals Changes in Ultrastructure and Oxidation Resistance of Peel of Pear Cultivars during Shelf Life

Agronomy ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 2274
Author(s):  
Hongliang Huo ◽  
Zhiqin Zhou ◽  
Jiayu Xu ◽  
Luming Tian ◽  
Xingguang Dong ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Antioxidant Capacity ◽  
Shelf Life ◽  
Postharvest Quality ◽  
Structure Stability ◽  
Oxygen Scavenging ◽  
Transmission Electron ◽  
Total Antioxidant ◽  
Scavenging Enzymes ◽  
And Function

Postharvest period is a process of natural maturation and senescence. The peel structure and antioxidant capacity of pears are the most important factors that affect its postharvest quality. However, the changes in pear peel properties are still unclear during shelf life. In this study, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to investigate the ultrastructural characteristics of pear peel during shelf life, and to determine the changes in peel antioxidants, active oxygen scavenging enzymes, and antioxidant capacity. The results showed that after a 30-day shelf life, the peel cuticles of all tested varieties had varying degrees of color loss and withering, and the integrity of the cells of peel was also damaged, but the surface layer cells of Xuehuali (XH), Huangguan (HG), and Yali (YL) were smoother than Wonhwang (WH) and Housui (HS), and the integrity of the peel cells was also better. In this experiment, there were significant differences in the contents of total polyphenol and total flavonoids among different varieties, and also significant differences in the variation range and variation trends in the activities of peroxidase and catalase (p < 0.05). The total antioxidant capacity of YL pear peel was the highest (68.76 Ug−1), while that of WH pear peel was the lowest (26.37 Ug−1). In conclusion, YL and XH, the representative varieties of White Pear, have better skin structure stability and antioxidant capacity than Sand Pear varieties HS and WH. The overall results provide a theoretical basis for further structure and function investigation of pear peel.

scholarly journals Quercetin ameliorates mitochondrial dysfunction and mitigates methamphetamine-induced anxiety-like behavior

2021 ◽  
Author(s):  
Fengrong Chen ◽  
Jiaxue Sun ◽  
Yongjin Zhang ◽  
Yicong Dai ◽  
Zherui Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Oxygen Consumption ◽  
Mitochondrial Dysfunction ◽  
Consumption Rate ◽  
Mitochondrial Morphology ◽  
Transmission Electron ◽  
Anxiety Behavior ◽  
And Function

Methamphetamine (MA) abuse results in neurotoxic outcomes, including increased anxiety and depression, during both MA use and withdrawal. Although numerous studies have reported an association between MA exposure and anxiety, the underlying mechanism remains elusive. In this study, escalating dose of MA was used to establish an MA-treated mouse model presenting anxiety behavior. RNA seq was then performed to profile the gene expression patterns in the hippocampus (HIPP). Differentially expressed genes (DEGs) were identified and function enrichment analysis was conducted to explore the underlying mechanisms. Quercetin as an mitochondria protector was used in vivo and in vitro. The C57BL/6J mice were co-treated with 50 mg/kg Quercetin and escalating MA. Anxiety behavior was evaluated by utilizing the elevated plus maze and the open field test. Transmission electron microscopy and immunohistochemistry were conducted to study the pathology of MA-inducced anxiety . The effects of MA and Quercetin on astrocytes were investigated by fluorescence staining, transmission electron microscopy, flow cytometry, and oxygen consumption rate. Western blot and qPCR were performed to analyze altered protein and gene levels of HIPP in mice and astrtocytes. The results demonstrated that forteen upregulated differentially expressed genes were identified and significantly enriched in signaling pathways related to psychiatric disorders and mitochondrial function. Interestingly, we found that quercetin was able to alleviate MA-induced anxiety-like behavior by improving neuron number and mitochondria injury. Mechanistically, quercetin can mitigate aberrant mitochondrial morphology and mitochondrial dysfunction not only by decreasing the levels of total cytoplasmic reactive oxygen species (ROS), mitochondria-derived ROS (mtROS), and mitochondrial membrane potential (MMP), but also increasing the oxygen consumption rate (OCR) and mitochondrial ATP production in vitro, indicating Quercetin ameliorated MA-induced anxiety-like behavior by modifying mitochondrial morphology and function. Furthermore, quercetin reversed OPA1 and DRP1 expression in astrocytes, and mitigated astrocyte activation and the release of inflammatory factors, which can trigger neuronal apoptosis and synaptic loss. Taken together, we provided evidence showing that MA can induce anxiety-like behavior via the induction of oxidative stress and mitochondrial dysfunction. Quercetin exerted antipsychotic activity through mitochondrial modulation, suggesting its potential for further therapeutic development in MA-induced anxiety.

scholarly journals Effect of Different Cooking Methods on Polyphenols, Carotenoids and Antioxidant Activities of Selected Edible Leaves

Antioxidants ◽  
2018 ◽  
Vol 7 (9) ◽  
pp. 117 ◽  
Author(s):  
K. Gunathilake ◽  
K. Ranaweera ◽  
H. Rupasinghe
Keyword(s):  
Antioxidant Activity ◽  
Antioxidant Capacity ◽  
Antioxidant Activities ◽  
Radical Scavenging ◽  
Leafy Vegetables ◽  
Cooking Methods ◽  
Oxygen Scavenging ◽  
Total Antioxidant ◽  
The Impact ◽  
Dpph Radical Scavenging

This study aimed to evaluate the effect of cooking (boiling, steaming, and frying) on polyphenols, flavonoids, carotenoids and antioxidant activity of six edible leaves. The total antioxidant capacity of the fresh and cooked leaves was determined using 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and singlet oxygen scavenging assays. The results revealed that frying caused a reduction in major bioactives and antioxidant activities in all leafy vegetables tested. However, steamed and boiled leaves of C. auriculata and C. asiatica have shown greater levels of polyphenols, flavonoids, and antioxidant capacity compared with fresh leaves. Polyphenol and flavonoid contents of boiled S. grandiflora and G. lactiferum were higher than that of their fresh form. Boiled and steamed O. zeylanica and S. grandiflora have shown higher carotenoids. Boiled and steamed leaves of P. edulis have shown higher antioxidant activity. The impact of cooking on the changes in bioactive concentrations and antioxidant capacities are dependent on the species and the method of cooking.

Progress in environmental high-voltage transmission electron microscopy for nanomaterials

2020 ◽  
Vol 378 (2186) ◽  
pp. 20190602
Author(s):  
Nobuo Tanaka ◽  
Takeshi Fujita ◽  
Yoshimasa Takahashi ◽  
Jun Yamasaki ◽  
Kazuyoshi Murata ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Voltage ◽  
High Energy ◽  
Transmission Electron ◽  
Recent Developments ◽  
In Situ Observations ◽  
High Voltage Transmission ◽  
And Function

A new environmental high-voltage transmission electron microscope (E-HVEM) was developed by Nagoya University in collaboration with JEOL Ltd. An open-type environmental cell was employed to enable in-situ observations of chemical reactions on catalyst particles as well as mechanical deformation in gaseous conditions. One of the reasons for success was the application of high-voltage transmission electron microscopy to environmental (in-situ) observations in the gas atmosphere because of high transmission of electrons through gas layers and thick samples. Knock-on damages to samples by high-energy electrons were carefully considered. In this paper, we describe the detailed design of the E-HVEM, recent developments and various applications. This article is part of a discussion meeting issue ‘Dynamic in situ microscopy relating structure and function'.

Ultrastructural histocytopathology of spleen of rat (Rattus norvegicus) induced by fluoride toxicity

2013 ◽  
Vol 3 (4) ◽  
pp. 183-187
Author(s):  
Arbind Kumar ◽  
Sapna Kumari
Keyword(s):  
Electron Microscopy ◽  
Rattus Norvegicus ◽  
Dental Fluorosis ◽  
Abdominal Cavity ◽  
Treated Group ◽  
Skeletal Fluorosis ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Reticular Fibers ◽  
And Function

Drinking water is one of the largest sources of fluoride. Excessive intake of fluoride results in all the three forms of fluorosis viz. Dental fluorosis, skeletal fluorosis and Non-skeletal fluorosis. Our present experiment was designed to study the non-skeletal fluorosis. The experimental animal Rattus norvegicus were randomly distributed into two groups of eight animals each. One group was given gavages of NaF at 50mg/kg-bw/day for 60 days along with the diet and the other group was paired fed which served as control. After 60 days the animals of both the group were sacrificed by cervical dislocation, the abdominal cavity was opened and spleens were dissected out. The tissue was further processed for light microscopy, transmission electron microscopy and scanning electron microscopy and analysed. Both light microscopic and electron microscopic observations showed damage to the reticular cells and reticular fibers of the spleen in the fluoride treated group. This may adversely affect the structure and function of the spleen grossly inhibiting the antigenic reactions resulting into the declination of the immune power.

Ciliation and function of the food-collecting and waste-rejecting organs of lophophorates

1978 ◽  
Vol 56 (10) ◽  
pp. 2142-2155 ◽  
Author(s):  
T. H. J. Gilmour
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Waste Material ◽  
Suspension Feeding ◽  
Food Material ◽  
Water Currents ◽  
Excess Water ◽  
Transmission Electron ◽  
Food Particles ◽  
And Function

Experiments with mixtures of colloidal graphite, stained Sephadex particles, and algae; observations by stroboscopic interference contrast optics; and scanning and transmission electron microscopy suggest that phoronids, brachiopods, and bryozoans can simultaneously reject waste material by an impingement mechanism and accept edible particles by a filtration mechanism without the ciliary reversals suggested in previous models of suspension feeding in lophophorates. Specialized laterofrontal cilia, which may detect heavy inedible particles, are found on the tentacles of all three phyla of lophophorates. In phoronids and bryozoans edible material is carried towards the esophagus by components of water currents created by the lateral cilia of the tentacles of the lophophore while inedible particles are rejected by the frontal cilia of the tentacles. The passage of food material to the mouths of brachiopods is assisted by frontal cilia located in grooves on alternate tentacles while the frontal cilia of ungrooved tentacles reject inedible material. The epistomes of lophophorates are also involved in the simultaneous acceptance of food and rejection of solid waste material and allow the escape of excess water travelling towards the mouth with food particles. This finding of a functional significance for the epistome suggests that lophophorates deserve reassessment as possible ancestors of chordates.

Calycinal trichomes in Ipomoea cairica (Convolvulaceae): ontogenesis, structure and functional aspects

2011 ◽  
Vol 59 (1) ◽  
pp. 91 ◽  
Author(s):  
Elder Antônio Sousa Paiva ◽  
Luiza Coutinho Martins
Keyword(s):  
Electron Microscopy ◽  
Developmental Stages ◽  
Glandular Trichomes ◽  
Structure And Function ◽  
Short Stalk ◽  
Transmission Electron ◽  
Functional Aspects ◽  
Acidic Polysaccharides ◽  
Low Humidity ◽  
And Function

The presence of calycinal trichomes in Ipomoea has been neglected, which renders the interpretation of their functions difficult. The present work aims to characterise the structure, as well as the composition of the secretion of calycinal trichomes in Ipomoea cairica, in order to establish a relationship between their structure and function. Samples of floral buds at different developmental stages and sepals from fruits were collected and fixed for study under light as well as under scanning and transmission electron microscopy. The calyx of I. cairica is persistent and presents glandular trichomes which produce acidic polysaccharides. The trichomes are peltate and consist of a short stalk and a pluricellular secretory portion. The cells from the secretory portion contain a dense and organelle-rich cytoplasm. The fresh secretion is hyaline and fluid, but solidifies when exposed to low humidity, taking on a crystalline and fragile aspect, and they return to a gel state when in the presence of water. The calycinal trichomes in I. cairica show great structural and ultrastructural similarities to colleters and can be considered functionally analogous. The secretion, which is highly hygroscopic, spreads along the surface of the corolla and of the fruit, apparently protecting these structures against desiccation.

scholarly journals Antioxidant and Antiapoptotic Effects of a Turraea fischeri Leaf Extract on Cryopreserved Goat Sperm

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2840
Author(s):  
Soha A. Hassan ◽  
Wael A. Khalil ◽  
Mahmoud A. E. Hassan ◽  
Ahmed I. Yousif ◽  
Omar M. Sabry ◽  
...  
Keyword(s):  
Antioxidant Capacity ◽  
Leaf Extract ◽  
Semen Quality ◽  
Soybean Lecithin ◽  
Sperm Concentration ◽  
Membrane Integrity ◽  
Transmission Electron ◽  
Total Antioxidant ◽  
Apoptotic Activity ◽  
Apoptosis And Necrosis

This study evaluated the efficacy of Turraea fischeri leaf extract for maintaining the viability of cryopreserved goat sperm. Ejaculated semen was collected from 5 mature Baladi bucks (50–60 kg, 2–4 years of age) and those samples with mass motility ≥ 70% and sperm concentration ≥ 2.5 × 109/mL were selected, pooled, and divided into 4 aliquots. Each aliquot was diluted in Tris-citric-soybean lecithin extender containing a different concentration of T. fischeri leaf extract (0, 125, 250, or 375 µg/mL). Treated semen samples were cooled to 5 °C, transferred to 0.25-mL French straws, and stored in liquid nitrogen (LN2) at −196 °C. After thawing, membrane integrity was examined by transmission electron microscopy, apoptotic activity by Annexin/propidium iodide staining and flow cytometry, and both enzyme activities and antioxidant capacity by spectroscopic assays. The leaf extract at 375 µg/mL significantly improved semen quality as indicated by enhanced total antioxidant capacity, reduced H2O2 concentration, a greater proportion of structurally intact motile sperm, and concomitant reductions in apoptosis and necrosis. The extract also significantly increased the proportion of sperm with a contiguous plasma membrane and intact acrosome (p < 0.05). Furthermore, LC-MS revealed numerous secondary metabolites in the extract that may contribute to sperm cryopreservation.

Elemental Ultrastructure of Bioleaching Bacteria and Archaea Grown on Different Energy Sources

2009 ◽  
Vol 71-73 ◽  
pp. 235-238
Author(s):  
Kayley M. Usher ◽  
Jeremy A. Shaw ◽  
Jason J. Plumb ◽  
Martin Saunders
Keyword(s):  
Electron Microscopy ◽  
Energy Source ◽  
Energy Sources ◽  
Free Medium ◽  
X Ray ◽  
Early Results ◽  
Transmission Electron ◽  
Distribution Of Elements ◽  
And Function ◽  
Electron Energy Loss

The composition and distribution of elements within cells of two species of Fe and S oxidising microbes utilising S, Fe2+ or chalcopyrite (CuFeS2) as an energy source were compared to determine possible sites of oxidation and function of intracellular granules. The bacterium Acidithiobacillus ferrooxidans and the archaeon Metallosphaera hakonensis were examined using energy filtered transmission electron microscopy (EFTEM), TEM energy dispersive X-ray spectroscopy (EDS), Scanning TEM (STEM) and electron energy-loss spectroscopy (EELS). Both species have intracellular granules and we show that these store Fe, S and P. The microbes slowly lost Fe from granules when switched to an Fe-free medium. EELS showed that the Fe in the granules of both species was consistent with Fe3+. Both microbes sometimes contain Cu and Si on their walls and intracellularly. Si concentrations have been shown to affect bioleach performance, so element deposition on the microbial catalyst may be a reason for this. Bands of Fe and S were present close to, or in, the cell membrane of M. hakonensis, as might be expected for the site of oxidation, and S also occurred throughout the cytoplasm. These are the first element maps of M. hakonensis, and these early results demonstrate that advanced characterisation and microanalysis techniques can provide insights into microbial processes involved in bioleaching.

Scanning electron microscopy of the septal pore cap of the basidiomycete Schizophyllum commune

1994 ◽  
Vol 40 (10) ◽  
pp. 879-883 ◽  
Author(s):  
Wally H. Müller ◽  
Adriaan C. van Aelst ◽  
Theo P. van der Krift ◽  
Teun Boekhout
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Schizophyllum Commune ◽  
Freeze Fracture ◽  
Freeze Substitution ◽  
Transmission Electron ◽  
And Function ◽  
Tubular Endoplasmic Reticulum ◽  
Scanning Electron

As part of a comparative study of the structure and function of pore structures in heterobasidiomycetous yeasts, dikaryotic hyphae of Schizophyllum commune were subjected to chemical fixation, freeze fracturing, maceration, and freeze substitution, and were subsequently prepared for scanning electron microscopy. The interior of the hyphal cell was visualized and revealed the perforated septal pore cap or parenthesome, mitochondria, vacuoles, and tubular endoplasmic reticulum. The septal pore cap showed connections with tubular endoplasmic reticulum. This tubular endoplasmic reticulum covered the dolipore septal surface. The results presented here complement and extend the ultrastructural image of the septal pore cap obtained from transmission electron micrographs.Key words: septal pore cap, Schizophyllum commune, freeze fracture, maceration, scanning electron microscopy.

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