Histochemical study of the oesophagus in the chukar partridge (Alectoris chukar) embryo

Study of the histogenesis of different organs is a useful laboratory method which helps us achieve accurate basic information about organ development during the embryonic period. It also reveals histological differences of each organ in different species. This research was carried out to study the histogenesis of the oesophagus of chukar partridge. For this purpose, the embryonated eggs were placed in the incubator and the embryos were collected between the 5th to 24th days of incubation period. The specimens were fixed in Bouin’s solution, and routine histotechnique processes were performed. The slides were finally stained with haematoxylin-eosin, Periodic Acid Schiff, Alcian Blue and Masson Trichrome, and the developmental changes of the oesophagus during the embryonic period were studied by light microscope. The four layers of oesophagus, including, the mucosa, submucosa, tunica muscularis and advantitia/serosa, both in cervical and thoracic oesophagus, were studied. During days 5 to 24 of incubation, developmental events in the oesophagus such as changes in the oesophageal epithelium, formation of muscularis mucosae and tunica muscularis, development of the mucous glands and the type of their secretion, were observed. Finally the results were compared with those of other studied avian species and the similarities and differences were discussed

Structure-Sensitive Mechanism of Nanographene Failure

The response of a nanographene sheet to external stresses is considered in terms of a mechanochemical reaction. The quantum chemical realization of the approach is based on a coordinate-of-reaction concept for the purpose of introducing a mechanochemical internal coordinate (MIC) that specifies a deformational mode. The related force of response is calculated as the energy gradient along the MIC, while the atomic configuration is optimized over all of the other coordinates under the MIC constant-pitch elongation. The approach is applied to the benzene molecule and (5, 5) nanographene. A drastic anisotropy in the microscopic behavior of both objects under elongation along a MIC has been observed when the MIC is oriented either along or normally to the C-C bonds chain. Both the anisotropy and high stiffness of the nanographene originate at the response of the benzenoid unit to stress.Comment: 19 pages, 7 figures 1 tabl

Biomacromolecular Journal Selective Determination of Dopamine in the Presence of Ascorbic Acid and Uric Acid at Neutral pH Using a Silver Nanoparticles-modified Carbon Paste Electrode

ABSTRACT Developing simple, sensitive and selective sensing systems for dopamine is important due to its biological significance. In this work, a silver nanoparticles-modified carbon paste electrode (AgNPs-CPE) has been constructed and used to detect of dopamine (DA) in the simultaneous presence of ascorbic acid (AA) and uric acid (UA) at neutral pH 7.0 by cyclic voltammetry. The modified electrode showed good performance toward the oxidation and determination of DA in the presence of AA and UA. In a mixture of the three compounds, DA showed a pair of redox peaks at about 182.0 and 116.0 mV for anodic and cathodic peaks potential, respectively, while AA and UA exhibited an oxidation peak at about 320.0 mV. Under these circumstances DA more easily oxidized than AA and UA at the surface of modified electrode and precisely determined by differential pulse voltammetry. A sensitivity of 0.074 μA/μM with a wide linear range of 12.5-300.0 μM and detection limit of 0.61 μM were obtained. The modified electrode was applied successfully for DA quantification in dopamine hydrochloride injection sample in the presence of AA and UA (100 μM)

Effect of covalent attachment of neomycin on conformational and aggregation properties of catalase

189-195<span style="font-size:9.0pt;mso-bidi-font-size: 12.0pt" lang="EN-US">The carboxylic groups of glutamic acid and aspartic acid residues of catalase (CAT) were chemically modified using the treatment of the enzyme with 1-ethyl-3-(3'-dimethylamino) carbodiimide hydrochloride (EDC) and neomycin. The effect of covalent attachment of neomycin on the enzymatic activity, conformational and aggregation properties of CAT was investigated. The modification of CAT with different concentrations of neomycin showed two different types of behavior, depending up on the concentration range of neomycin. In the concentration range from 0.0 to 5.2 mM, neomycin-modified CAT, compared to the native enzyme exhibited higher α-helix content, reduced surface hydrophobicity, little enhancement in CAT activity and a better protection against thermal aggregation, whereas at concentrations greater than 5.2 mM, the modified enzyme exhibited a significant decrease in CAT activity and an increase in random coil content which may result in disorder in the protein structure and increase in thermal aggregation. This modification is a rapid and simple approach to investigate the role of aspartate and glutamate residues in the structure, function and folding of CAT. </span

Finite-Element Performance Evaluation of On-Line Transformer Internal Fault Detection Based on Instantaneous Voltage and Current Measurements

This paper investigates the performance of a recently proposed online transformer internal fault detection technique through detailed non-linear three-dimensional finite element modelling of the windings, magnetic core and transformer tank. The online technique considers correlation of transformer instantaneous input and output voltage difference and input current at the power frequency and uses the ellipse shape ΔV-I locus as the finger print of the transformer that could be measured every cycle to identify any incipient faults. The technique is simple, fast and suitable for online monitoring of in-service transformers. A detailed three-dimensional finite element model of single-phase transformer is developed and various physical winding deformations with different fault levels are simulated to assess their impacts on the online ΔV-I locus. As transformer field testing under various internal fault conditions cannot be easily conducted, the main contributions of this paper are accurate finite element based implementation, testing and performance evaluation of the online fault detection approach. Furthermore, the impact of winding short circuit fault on the ΔV-I locus has been also measured and validated

Combination of metformin and chlorogenic acid attenuates hepatic steatosis and inflammation in high-fat diet fed mice

Non-alcoholic fatty liver disease (NAFLD) has become an important health problem in the world. Natural products, with anti-inflammatory properties, are potential candidates for alleviating NAFLD. Metformin (MET) and chlorogenic acid (CGA) have been reported to be effective in the improvement of NAFLD. Here, we aimed to evaluate the efficacy of MET and CGA combination in ameliorating NAFLD in high-fat diet (HFD) fed mice. Fifty C57BL/6 male mice were divided into two groups, one fed a standard chow diet (n = 10) and the other was fed an HFD (n = 40) for 10 weeks. Animals in the HFD group were then randomly divided into a four groups (HFD, HFD + MET (0.25), HFD + CGA (0.02) and HFD + MET + CGA (0.25 + 0.02). MET and CGA combination decreases fasting blood glucose and improves glucose intolerance. Decreased hepatic triglyceride level was associated with lower expression levels of fatty acid synthase and sterol regulatory element-binding protein-1c in MET+CGA treated mice. MET and CGA combination treatment resulted in the polarization of macrophages to the M2 phenotype, reduction of the expression of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6), and decreasing protein level of NF-kB p65. It was found that the lowering effect of combined MET and CGA on the expression of gluconeogenic genes was accompanied by increasing phosphorylation of glycogen synthase kinase 3β. Treatment of HFD mice with the combination of MET and CGA was found to be more effective at alleviating inflammation and lipid accumulation by increasing phosphorylation of AMP-activated protein kinase. In conclusion, these findings suggest that the MET + CGA combination might exert therapeutic effects against NAFLD. © 2020 International Union of Biochemistry and Molecular Biolog

Scanning electron microscopy of Onchocerca fasciata (Filarioidea: Onchocercidae) adults, microfilariae and eggs with notes on histopathological findings in camels

Background: Onchocerca fasciata is a prevalent flarial species in camelids of Asia and Africa forming nodules in the skin of dromedary and Bactrian camels. In spite of recent advances in the biology and epidemiology of this nematode species, a relatively scant number of studies have focussed on the morphology of this parasite. The main objective of this study was to describe morphological characteristics of adults, microflariae and eggs of O. fasciata by scanning electron microscopy (SEM), staining and histology. Methods: From April 2016 to March 2017 dromedary camels (n=456) were inspected for infection with O. fasciata in a slaughterhouse in Kerman (south of Iran). Adult worms in nodules were isolated by digestion of nodules in collagenase and used for SEM. Skin nodules were also fxed, sectioned and stained with hematoxylin and eosin for histo‑ pathology. Skin microflariae that were isolated from tissues surrounding the nodules were confrmed as O. fasciata by sequencing of the cytochrome c oxidase subunit 1 (cox1) and 12S rRNA genes and used for SEM and Giemsa staining. Results: Single or multiple O. fasciata nodules (1.2–2.2 cm in diameter and 507–845 mg in weight) were found in 30.3% of the examined camels. SEM analysis helped identify 18 papillae in the caudal region of the male. Discontinu‑ ous longitudinal cuticular crests were observed in the posterior region of the male. In female nematodes, the ridges had a rounded shape with a height/width ratio of 7/16 in longitudinal sections. Unsheathed skin microflariae with a rounded anterior extremity measured 210.7×2.5 μm on average. Developed eggs containing microflariae measured 35.9×31.0 μm and their smooth shell surface had characteristic tongue-like appendages. In addition to infammatory reactions surrounding the parasites, accumulation of intracellular ceroid pigment, golden-yellow to brown in colour, was observed within macrophages upon histopathological examination. Conclusions: We found longitudinal crests on the surface of the posterior region of the male nematode. Measure‑ ments of the main morphological features of microflariae and eggs, and the shape index of ridges (height/width) in female nematodes are described for the frst tim