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排序方式: 共有534条查询结果,搜索用时 15 毫秒
1.
Aseem Grover Reshma Sinha Divya Jyoti Caterina Faggio 《Microscopy research and technique》2022,85(5):1976-1989
Electron microscope (EM) was developed in 1931 and since then microscopical examination of both the biological and non-biological samples has been revolutionized. Modifications in electron microscopy techniques, such as scanning EM and transmission EM, have widened their applicability in the various sectors such as understanding of drug toxicity, development of mechanism, criminal site investigation, and characterization of the nano-molecule. The present review summarizes its role in important aspects such as toxicity assessment and disease diagnosis in special reference to SARS-COV2. In the biological system, EM studies have elucidated the impact of toxicants at the ultra-structural level in various tissue in conformity to physiological alterations. Thus, EM can be concluded as an important tool in toxicity assessment and disease prognosis. 相似文献
2.
Lorenzo Alibardi 《Microscopy research and technique》2020,83(8):889-900
Adhesive pads of geckos contain many thousands of nanoscale spatulae for the adhesion and movement along vertical or inverted surfaces. Setae are composed of interlaced corneous bundles made of small cysteine‐glycine‐rich corneous beta proteins (CBPs, formerly indicated as beta‐keratins), embedded in a matrix material composed of cytoskeletal proteins and lipids. Negatively charged intermediate filament keratins (IFKs) and positively charged CBPs likely interact within setae, aside disulphide bonds, giving rise to a flexible and resistant corneous material. Using differernt antibodies against CBPs and IFKs an updated model of the composition of setae and spatulae is presented. Immunofluorescence and ultrastructural immunogold labeling reveal that one type of neutral serine‐tyrosine‐rich CBP is weakly localized in the setae while it is absent from the spatula. This uncharged protein is mainly present in the thin Oberhautchen layer sustaining the setae, although with a much lower intensity with respect to the cysteine‐rich CBPs. These proteins in the spatula likely originate a positively charged or neutral contact surface with the substrate but the influence of lipids and cytoskeletal proteins present in setae on the mechanism of adhesion is not known. In the spatula, protein‐lipid complexes may impart the pliability for the attachment and adapt to irregular surfaces. The presence of cysteine‐glycine medium rich CBPs and softer IFKs in alpha‐layers sustaining the setae forms a flexible base for compliance of the setae to substrate and improved adhesion. 相似文献
3.
Chunyan Xu Ying Wang Daodong Pan Changyu Zhou Jun He Jinxuan Cao 《International Journal of Food Science & Technology》2021,56(4):1690-1702
To investigate the effect of cooking temperature (55, 65, 75, 85 and 95 °C) on texture and flavour binding of braised sauce porcine skin (BSPS), sensory acceptance, microstructure and flavour-binding capacity were investigated during the processing of BSPS. Samples cooked at 85 and 95 °C showed better texture and aroma scores. Hardness and chewiness of BSPS were obviously improved at 85 and 95 °C than control group. Collagen structure was significantly destroyed over 85 °C. The porcine skin collagen heated at 85 and 95 °C showed relatively higher flavour-binding capacity than other samples. The improvement of texture of BSPS was mainly attributed to the degradation of collagen. Higher aroma scores of BSPS were related to intense binding abilities with aroma compounds at 85 and 95 °C. Cooking at 85 or 95 °C could be an optimal cooking temperature for BSPS. 相似文献
4.
Mohammed I. A. Ibrahim Musa Zakariah Reneilwe A. Molele Mohamed A. A. Mahdy June H. Williams Christo J. Botha 《Microscopy research and technique》2022,85(3):1160-1170
The testicular excurrent duct system undergoes several physiological and morphological changes during the reproductive stage or breeding season in mammals, birds, and reptiles. Studies on normal age-related histomorphological changes in the excurrent duct system of Japanese quails (Coturnix japonica) remain unreported, despite the extensive use of this bird as an avian model in research studies. The current study investigated the histological, ultrastructural, and histometric changes in the testicular excurrent duct system of the Japanese quail during three reproductive stages, namely prepubertal, pubertal, and adult. Simple squamous to low cuboidal cells formed the epithelia of the rete testis in prepubertal and pubertal birds, while in adult birds the lining was low cuboidal to cuboidal. In pubertal and adult birds, the nonciliated Type I epithelial cells of the proximal efferent duct displayed a subapical endocytotic apparatus comprising coated pits, coated apical tubules, and endosomes. There was a significant increase (p ≤ .001) in epithelial heights of all ducts of the excurrent duct system in the mature, sexually active, adult birds when compared to the other age groups. The luminal and tubular diameters, and the cross-sectional areas of efferent ducts and the epididymal duct unit increased significantly (p ≤ .001) with age. It is concluded that the morphology and morphometry of the excurrent ducts of the testis of the Japanese quail change as birds mature. 相似文献
5.
Roberta Barbizan Mateus V. Castro Rui Seabra Ferreira Jr. Benedito Barraviera Alexandre L. R. Oliveira 《International journal of molecular sciences》2014,15(11):19535-19551
We recently proposed a new surgical approach to treat ventral root avulsion, resulting in motoneuron protection. The present work combined such a surgical approach with bone marrow mononuclear cells (MC) therapy. Therefore, MC were added to the site of reimplantation. Female Lewis rats (seven weeks old) were subjected to unilateral ventral root avulsion (VRA) at L4, L5 and L6 levels and divided into the following groups (n = 5 for each group): Avulsion, sealant reimplanted roots and sealant reimplanted roots plus MC. After four weeks and 12 weeks post-surgery, the lumbar intumescences were processed by transmission electron microscopy, to analyze synaptic inputs to the repaired α motoneurons. Also, the ipsi and contralateral sciatic nerves were processed for axon counting and morphometry. The ultrastructural results indicated a significant preservation of inhibitory pre-synaptic boutons in the groups repaired with sealant alone and associated with MC therapy. Moreover, the average number of axons was higher in treated groups when compared to avulsion only. Complementary to the fiber counting, the morphometric analysis of axonal diameter and “g” ratio demonstrated that root reimplantation improved the motor component recovery. In conclusion, the data herein demonstrate that root reimplantation at the lesion site may be considered a therapeutic approach, following proximal lesions in the interface of central nervous system (CNS) and peripheral nervous system (PNS), and that MC therapy does not further improve the regenerative recovery, up to 12 weeks post lesion. 相似文献
6.
Jichao Huang Liang Zhao Jing Yang Baohua Zhang Xinglian Xu Kenjie Chen Ming Huang 《Journal of food science》2019,84(5):1054-1059
This study was designed to determine the effects of µ/m‐calpain on the degradation of cytoskeletal proteins in pectoralis major. Four chickens were slaughtered and the breasts were removed and stored for 12 hr at 4 °C. Each sample was divided into three groups and respectively immersed in control reagent, calpain inhibitor, and caspase inhibitor at 4 °C. The samples were used to evaluate troponin‐T and desmin degradation, calpain activity, and myofibril ultrastructure at 12 hr, day 1, day 3, and day 7. Casein zymography revealed that µ‐calpain could not be detected in all samples after 12 hr postmortem. The calpain inhibitor inhibited µ/m‐calpain activity and reduced troponin‐T and desmin degradation during 7 day postmortem. The caspase inhibitor inhibited µ/m‐calpain activity and, troponin‐T and desmin degradation before day 3 postmortem. The findings suggest that, µ/m‐calpain had an effect on cytoskeletal protein degradation after 12 hr postmortem. 相似文献
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9.
《Food Control》2014
The antifungal activity of Lactobacillus plantarum K35 isolated from traditional Thai fermented rice noodle was evaluated against the growth and aflatoxin production of Aspergillus flavus TISTR304 and Aspergillus parasiticus TISTR3276. Multiple antifungal compounds secreted by L. plantarum were firstly analyzed using GC–MS in parallel to the ultrastructure alteration of the treated fungi. L. plantarum K35 supernatant caused significant reduction of the fungal growth and aflatoxin production. The antifungal activity was pH-dependent and favorable to acidic conditions whereas the catalase treatment had no influence indicating no involvement of hydrogen peroxide in the inhibition. Antifungal substances were resistant to sterilization and proteolytic enzymes including trypsin and proteinase K. The major components, apart from lactic acid, were 2-butyl-4-hexyloctahydro-1H-indene (19.55%), oleic acid (10.52%) and palmitic acid (7.27%). Other minor antifungal compounds included linoleic acid (2.11%), 2,4-di-tert-butylphenol (1.84%), stearic acid (1.55%), 3-phenyllactic acid (1.42%) and pyroglutamic acid (1.07%). The morphological changes of the fungi exposed to the supernatant were observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). L. plantarum K35 supernatant caused severe damage to the cell wall and cytoplasmic membrane leading to a massive loss of cytoplasmic content, the formation of membrane-bound vesicles, and complete destruction of membranous organelles including mitochondria and nucleus. 相似文献
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