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Detection Assays and Techniques Against COVID-19
Published in Hanadi Talal Ahmedah, Muhammad Riaz, Sagheer Ahmed, Marius Alexandru Moga, The Covid-19 Pandemic, 2023
Shahzad Sharif, Maham Saeed, Javed Hussain Shah, Sajjad Hussain, Ahmad Adnan, Hanadi Talal Ahmedah, Muhammad Riaz
It is a device that is based on an electronic system due to its short wavelength, and it has 100,000 times more resolution power than a compound microscope. The electronic microscope is used for the study of the structure of the nanoparticle. It has a very high-resolution and detection power. So here it is used to study the detection of viruses and their structure. As every test needs some specification to study the specific pathogen or any microorganism but the electronic microscope does not need such kind of tests. So, we can say that an electron microscope helps us to identify the virus and its structure and also help in designing the medicine or vaccine for the appropriate pathogen [129].
Pathology and Epidemiology
Published in John T. Kemshead, Pediatric Tumors: Immunological and Molecular Markers, 2020
The use of resin-embedded material for light microscopic examination carries the obvious advantage that if the tissue has been appropriately fixed in glutaraldehyde, it is usually easy to progress to electron microscopic examination of the same block of tissue. The use of semithin sections has, however, been specifically recommended19 for the purpose of substituting for electron microscopy, especially in the very demanding area of the differential diagnosis of the malignant lymphomas. Whether or not one wholly accepts this point of view, their use can certainly defer the use of the very expensive and time-consuming modality of electron microscopy until time and facilities permit.
Electron Microscopy in Lung Research
Published in Joan Gil, Models of Lung Disease, 2020
Two types of electron microscope are widely available: transmission electron microscopes (TEMs) and scanning electron microscopes (SEMs). Each uses a different mechanism of image formation and gives a different kind of information (Fig. 1) (Watt, 1985). In the TEM, a thin specimen, usually less than 0.1 μm thick, is placed in the electron beam. The electrons pass through the specimen and are brought to a focus on a fluorescent screen or photographic film beneath it. Contrast results from scattering of electrons as they pass through the specimen. The unscattered electrons pass through the specimen to interact with the fluor of the screen or photographic emulsion. Scattering of electrons is a function of the atomic number of the atoms making up the specimen. The bulk of biological material is made up of elements of low atomic number (hydrogen, oxygen, carbon, and nitrogen), so most biological samples have little inherent electron contrast. Contrast is usually introduced by the OsO4 used nearly universally as a fixative, and by the use of heavy metal stains.
Endocarditis-associated rapidly progressive glomerulonephritis mimicking vasculitis: a diagnostic and treatment challenge
Published in Annals of Medicine, 2022
Sanxi Ai, Jianzhou Liu, Guotao Ma, Wenling Ye, Rongrong Hu, Shangzhu Zhang, Xiaohong Fan, Bingyan Liu, Qi Miao, Yan Qin, Xuemei Li
Renal biopsies were performed in 9 patients and histologic findings are illustrated in Figures 1–3 and summarized in Table 3. On light microscopy, all patients presented with mesangial and/or endothelial hypercellularity. Extensive crescents formation (accounting for 34 ∼ 67% of glomeruli) were observed in seven of the nine cases. Two cases had clinical presentations of RPGN but no crescent formation on histology. Case 21 presented with focal mesangial hypercellularity and she underwent renal biopsy after two months of treatment when her serum creatinine had decreased from 11.6 mg/dl to 0.8 mg/dl. Case 22 presented with diffuse endocapillary proliferative glomerulonephritis (Figure 1(F)). Fibrinoid necrosis was observed in two of the three cases who were seropositive for ANCA and none of the five cases with negative ANCA. Acute tubular injury and interstitial inflammation were present in all cases. On immunofluorescence, C3 was present in seven of the nine cases and predominant in five. IgM was found in five cases, IgA in three cases, and IgG in one case. One case presented with pauci-immune glomerulonephritis with no significant deposit on immunofluorescence or electronic microscopy. Electron microscopy examination was performed in five cases. Deposits in mesangial and/or subendothelial area were noted in four of the five cases, but subepithelial deposits were occasionally observed in only one case.
Progress in the development of stabilization strategies for nanocrystal preparations
Published in Drug Delivery, 2021
Jingru Li, Zengming Wang, Hui Zhang, Jing Gao, Aiping Zheng
The sizes and shapes of nanocrystals were analyzed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In SEM, image results are generated through the interaction between the electron beam and atoms at various depths in the sample. For example, by collecting secondary electrons and backscattered electrons, information about the microstructure of the material can be obtained (Figure 7). In a transmission electron microscope, an image is obtained by capturing transmitted electrons in a sample. The accelerated and clustered electron beam can be transmitted to a very thin sample, and the electrons collide with the atoms in the sample and change direction, thereby generating solid angle scattering, which can be used to observe the ultrastructures of particles, and the resolution can reach 0.1 ∼ 0.2 nm (Figure 8).
Use of electron microscopy to study platelets and thrombi
Published in Platelets, 2020
Maurizio Tomaiuolo, Rustem I. Litvinov, John W. Weisel, Timothy J. Stalker
The study of platelet biology using electron microcopy methods has a long and rich history. It was not long after the introduction of the electron microscope that the first studies of platelet ultrastructure using transmission electron microscopy were published [1]. Conventional electron microscopy is divided into transmission electron microscopy (TEM) and scanning electron microscopy (SEM). In TEM, a beam of electrons is transmitted through a thin section in order to visualize the internal structures. By contrast in SEM, a focused beam of electrons is used to scan the surface of a specimen. A considerable amount of work went into developing the protocols to fix soft tissues so that they could be imaged by electron microscopy, work strongly motivated by the need to visualize tissues and their internal structures in ways that were not possible with any other microscopy technique before. Once the proper fixation protocols had been developed, electron microscopy became instrumental to study platelets, both for basic research [2] and as a diagnostic tool [3]. Today, conventional TEM and SEM approaches remain valuable tools in platelet and thrombosis research, even as EM approaches continue to evolve and new imaging modalities are developed.