Intrinsic Optical Properties of Brain Slices: Useful Indices of Electrophysiology and Metabolism
Avital Schurr, Benjamin M. Rigor in BRAIN SLICES in BASIC and CLINICAL RESEARCH, 2020
In general, minimal modifications of standard recording chambers are required for optical studies in brain slices. Provisions only need to be furnished for delivery and collection of light required for the desired optical measurement. Both interface and submersion chambers would appear to be suitable, although one type or the other may be preferred for a selected optical recording. For example, high-magnification measurements from single cells or cell processes may require slice submersion and the use of water immersion microscope objectives. Macroscopic measurements of whole brain slices, on the other hand, may be more easily conducted in interface chambers because of longer working distances between the slice and microscope objective and to avoid a fluid-air interface above the slice surface. It is important to stress that the recording requirements vary considerably depending upon the goals of the experiment. For imaging experiments, provision for the microscope may be an overriding factor in chamber design. When imaging is not required, other means of light collection such as fiber optics may be preferred and may be more efficient. A microscope, however, is a very convenient means of collecting light from brain slices and is easily interfaced to most light measuring instruments.
Telescopes for Inner Space: Fiber Optics and Endoscopes
Suzanne Amador Kane, Boris A. Gelman in Introduction to Physics in Modern Medicine, 2020
We can use optical microscopes to obtain magnified virtual images of microscopic objects. The main optical components of a compound microscope are an objective lens and an eyepiece lens. In Figure 2.9e, these parts are represented by two lenses. The objective lens, which is the closest to the object AB, forms a real image, A′B′. By adjusting the distance between the objective and the eyepiece, the image A′B′ can be placed very near the focus of the eyepiece lens. Using the ray tracing rules discussed above, we can show that the rays coming from the real image after passing through the eyepiece create a virtual image (see Figure 2.9e), which is magnified to a large degree compared with the size of the original object. Magnification, also called the power, of modern optical microscopes can be as high as 1000.
Laryngotracheal stenosis
Declan Costello, Guri Sandhu in Practical Laryngology, 2015
Prolonged spontaneous breathing anaesthetic techniques are not possible in adult patients. Adults tend to lighten from anaesthesia much more rapidly, with the associated risk of laryngospasm. Also, access to the larynx in an adult is much easier in a paralysed patient. Suspension laryngoscopy is performed routinely by otolaryngologists for assessment of the supraglottic and glottic larynx. Laryngologists are also comfortable operating on the subglottis via a microscope or rigid endoscope. The advantages of the microscope are binocular vision, depth of field and superior axial illumination and it allows two hands free for instrumentation. Also, the laser can be used with a ‘line-of-sight’ technique through a micromanipulator attached to the microscope. Some otolaryngologists still use the ventilating bronchoscope for tracheal or bronchial assessment and surgery. Suspension laryngoscopy allows the use of both optical rigid endoscopes and flexible bronchoscopes to access the airway. The advantages are that the patient is paralysed and the full spectrum of rigid instrumentation, dilators, lasers and stents can be inserted and used with relative ease. As the patient is ventilated using a supraglottic jetting technique, lasers can also be used without the risk of fires, providing no flammable material is introduced into the airway.
Regenerative responses of rabbit corneal endothelial cells to stimulation by fibroblast growth factor 1 (FGF1) derivatives, TTHX1001 and TTHX1114
Published in Growth Factors, 2021
Jessica Weant, David D. Eveleth, Amuthakannan Subramaniam, Jennifer Jenkins-Eveleth, Michael Blaber, Ling Li, David M. Ornitz, Asaf Alimardanov, Trevor Broadt, Hui Dong, Vinay Vyas, Xiaoyi Yang, Ralph A. Bradshaw
The intact corneal endothelium is a hexagonal array that is characterised by tight junctions, and it is these structures that are detected by the Konan specular microscope (see Figure 5). When lesions are introduced, as was the case in these studies, the wound healing responses observed may be due to the proliferation of new cells and/or migration of already formed cells into the centre of the cornea from the periphery. As the lesion disrupts the contact inhibition that stabilises the monolayer, this may allow arrested proliferation to recur and thus be a contributing factor to the wound healing processes. Transplantation studies with fragments of Descemet’s (Baydoun et al. 2018; Birbal et al. 2018) indicate that migration is also a major factor in sealing corneal lesions, being able to cover significant amounts of the disrupted area.
The Diagnostic Value of ischemia-modified albumin (IMA) and signal peptide-CUB-EGF domain-containing protein-1 (SCUBE-1) in an Experimental Model of Strangulated Mechanical Bowel Obstruction
Published in Journal of Investigative Surgery, 2022
Arif Burak Cekic, Ozgen Gonenc Cekic, Ali Aygun, Sinan Pasli, Serap Yaman Ozer, Suleyman Caner Karahan, Suleyman Turedi, Sami Acar, Ozgur Tatli, Esin Yulug
At histopathological analysis the ileum specimens were examined macroscopically, after which 1-cm sections were taken and examined in terms of histopathological changes. IMA and SCUBE-1 levels were determined for each group, and macro- and microscopic tissue examination findings were compared between the groups. A light microscope was employed for microscopic examination. Tissues were placed in 10% formaldehyde for light microscopic examination. Following routine application of xylol and alcohol, the specimens were embedded in paraffin blocks. Five-micrometer sections were taken using a microtome (Leica RM2255, Japan), and stained with hematoxylin-eosin and cresyl violet. The ileum preparates were than analyzed by an experienced histologist blinded to the study groups. Semi-quantitative ileum damage scoring was employed to assess the groups’ ileum tissues. Under this system, ileum specimens from the study groups were assessed in terms of villus apical surface epithelial degeneration, inflammatory cell infiltration, villous fusion, and hemorrhage. As a result of the histopathologic examinations, it was scored according to the following scale (Table 1); mean scores were then calculated for each group.13
Surface-modified polymeric nanoparticles for drug delivery to cancer cells
Published in Expert Opinion on Drug Delivery, 2021
Arsalan Ahmed, Shumaila Sarwar, Yong Hu, Muhammad Usman Munir, Muhammad Farrukh Nisar, Fakhera Ikram, Anila Asif, Saeed Ur Rahman, Aqif Anwar Chaudhry, Ihtasham Ur Rehman
Microscopic studies are conducted to elucidate the morphology and topography of nanoparticles. The structural information clarifies other features such as hydrophobicity, agglomeration, and interaction with cells. In microscopic imaging techniques, two main approaches are employed to obtain a real image of the sample. First, the sample surface is scanned point by point using a probe beam of smaller diameter. Examples of this category are Scanning electron microscope (SEM), field emission SEM (FESEM), Scanning tunneling microscope, and scanning probe microscope (SPM). Second, the surface is illuminated with electron beam, and a direct image is obtained via the optical path of instrument. Representative examples of this type include optical microscopy and transmission electron microscopy (TEM) [138]. In electron microscopy, SEM or FESEM provide two-dimensional imaging, which could provide information about size, shape, distribution, and hierarchy of surface features of polymeric nanoparticles. Furthermore, Atomic force microscopy (AFM), an example of SPM, can give three-dimensional imaging. It also determines the size, morphology, surface texture, roughness, distribution, and nanoparticle volume [139].
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