In Vivo Structural Characteristics of the Femtosecond LASIK-Induced Opaque Bubble Layers with Ultrahigh-Resolution SD-OCT

2010 ◽  
Vol 41 (6) ◽  
pp. S109-S113 ◽  
Author(s):  
Volkan Hurmeric ◽  
Sonia H. Yoo ◽  
Jane Fishler ◽  
Victoria S. Chang ◽  
Jianhua Wang ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Ultrahigh Resolution ◽  
Bubble Layers ◽  
Sd Oct

Use of light microscopy in the qualitative and quantitative study of liquid crystalline order

1992 ◽  
Vol 50 (1) ◽  
pp. 264-265
Author(s):  
Christopher Viney
Keyword(s):  
Light Microscopy ◽  
Liquid Crystalline ◽  
Structural Characteristics ◽  
Molecular Order ◽  
Liquid Crystalline Phases ◽  
Convenient Technique ◽  
Liquid Crystalline Materials ◽  
Transparent Windows

Light microscopy is a convenient technique for characterizing molecular order in fluid liquid crystalline materials. Microstructures can usually be observed under the actual conditions that promote the formation of liquid crystalline phases, whether or not a solvent is required, and at temperatures that can range from the boiling point of nitrogen to 600°C. It is relatively easy to produce specimens that are sufficiently thin and flat, simply by confining a droplet between glass cover slides. Specimens do not need to be conducting, and they do not have to be maintained in a vacuum. Drybox or other controlled environmental conditions can be maintained in a sealed chamber equipped with transparent windows; some heating/ freezing stages can be used for this purpose. It is relatively easy to construct a modified stage so that the generation and relaxation of global molecular order can be observed while specimens are being sheared, simulating flow conditions that exist during processing. Also, light only rarely affects the chemical composition or molecular weight distribution of the sample. Because little or no processing is required after collecting the sample, one can be confident that biologically derived materials will reveal many of their in vivo structural characteristics, even though microscopy is performed in vitro.

Misalignment of foveal pit and foveal bulge determined by ultrahigh-resolution SD-OCT in normal eyes

2020 ◽  
Vol 258 (10) ◽  
pp. 2131-2139
Author(s):  
Yoshitsugu Matsui ◽  
Ryohei Miyata ◽  
Eriko Uchiyama ◽  
Hisashi Matsubara ◽  
Mineo Kondo
Keyword(s):  
Ultrahigh Resolution ◽  
Sd Oct

scholarly journals Optimization of spectral-domain optical coherence tomography with a supercontinuum source for in vivo motion detection of low reflective outer hair cells in guinea pig cochleae

2021 ◽  
Author(s):  
Fumiaki Nin ◽  
Samuel Choi ◽  
Takeru Ota ◽  
Zhang Qi ◽  
Hiroshi Hibino
Keyword(s):  
Optical Coherence Tomography ◽  
High Resolution ◽  
Guinea Pig ◽  
Hair Cells ◽  
Sensory Epithelium ◽  
Outer Hair Cells ◽  
Acquisition Time ◽  
Total Acquisition Time ◽  
Sd Oct

AbstractSound evokes sub-nanoscale vibration within the sensory epithelium. The epithelium contains not only immotile cells but also contractile outer hair cells (OHCs) that actively shrink and elongate synchronously with the sound. However, the in vivo motion of OHCs has remained undetermined. The aim of this work is to perform high-resolution and -accuracy vibrometry in live guinea pigs with an SC-introduced spectral-domain optical coherence tomography system (SD-OCT). In this study, to reveal the effective contribution of SC source in the recording of the low reflective materials with the short total acquisition time, we compare the performances of the SC-introduced SD-OCT (SCSD-OCT) to that of the conventional SD-OCT. As inanimate comparison objects, we record a mirror, a piezo actuator, and glass windows. For the measurements in biological materials, we use in/ex vivo guinea pig cochleae. Our study achieved the optimization of a SD-OCT system for high-resolution in vivo vibrometry in the cochlear sensory epithelium, termed the organ of Corti, in mammalian cochlea. By introducing a supercontinuum (SC) light source and reducing the total acquisition time, we improve the axial resolution and overcome the difficulty in recording the low reflective material in the presence of biological noise. The high power of the SC source enables the system to achieve a spatial resolution of 1.72 ± 0.00 μm on a mirror and reducing the total acquisition time contributes to the high spatial accuracy of sub-nanoscale vibrometry. Our findings reveal the vibrations at the apical/basal region of OHCs and the extracellular matrix, basilar membrane.

scholarly journals Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1441
Author(s):  
Yangpeng Lu ◽  
Yanan Jia ◽  
Zihan Xue ◽  
Nannan Li ◽  
Junyu Liu ◽  
...  
Keyword(s):  
Biological Activities ◽  
Structural Characteristics ◽  
Potential Candidate ◽  
Health Food ◽  
Inonotus Obliquus ◽  
Recent Developments ◽  
Inonotus Obliquus Polysaccharide ◽  
Future Work

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.

scholarly journals Design and Implementation Guidelines for a Modular Spectral-Domain Optical Coherence Tomography Scanner

2018 ◽  
Vol 2018 ◽  
pp. 1-22 ◽  
Author(s):  
Farid Atry ◽  
Israel Jacob De La Rosa ◽  
Kevin R. Rarick ◽  
Ramin Pashaie
Keyword(s):  
Optical Coherence Tomography ◽  
Imaging System ◽  
Optical Design ◽  
Spectral Domain ◽  
Design Parameters ◽  
Optical Coherence ◽  
Custom Made ◽  
Essential Knowledge ◽  
Sd Oct

In the past decades, spectral-domain optical coherence tomography (SD-OCT) has transformed into a widely popular imaging technology which is used in many research and clinical applications. Despite such fast growth in the field, the technology has not been readily accessible to many research laboratories either due to the cost or inflexibility of the commercially available systems or due to the lack of essential knowledge in the field of optics to develop custom-made scanners that suit specific applications. This paper aims to provide a detailed discussion on the design and development process of a typical SD-OCT scanner. The effects of multiple design parameters, for the main optical and optomechanical components, on the overall performance of the imaging system are analyzed and discussions are provided to serve as a guideline for the development of a custom SD-OCT system. While this article can be generalized for different applications, we will demonstrate the design of a SD-OCT system and representative results for in vivo brain imaging. We explain procedures to measure the axial and transversal resolutions and field of view of the system and to understand the discrepancies between the experimental and theoretical values. The specific aim of this piece is to facilitate the process of constructing custom-made SD-OCT scanners for research groups with minimum understanding of concepts in optical design and medical imaging.

Compact, low-cost Ti:Al_2O_3 laser for in vivo ultrahigh-resolution optical coherence tomography

2003 ◽  
Vol 28 (11) ◽  
pp. 905 ◽  
Author(s):  
A. Unterhuber ◽  
B. Považay ◽  
B. Hermann ◽  
H. Sattmann ◽  
W. Drexler ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Low Cost ◽  
Optical Coherence ◽  
Ultrahigh Resolution

scholarly journals The State of the Art and Prospects for Osteoimmunomodulatory Biomaterials

Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1357
Author(s):  
Andreea-Mariana Negrescu ◽  
Anisoara Cimpean
Keyword(s):  
Foreign Bodies ◽  
Structural Characteristics ◽  
Critical Role ◽  
Fibrous Tissue ◽  
Bioactive Molecules ◽  
New Bone Formation ◽  
Recent Developments

The critical role of the immune system in host defense against foreign bodies and pathogens has been long recognized. With the introduction of a new field of research called osteoimmunology, the crosstalk between the immune and bone-forming cells has been studied more thoroughly, leading to the conclusion that the two systems are intimately connected through various cytokines, signaling molecules, transcription factors and receptors. The host immune reaction triggered by biomaterial implantation determines the in vivo fate of the implant, either in new bone formation or in fibrous tissue encapsulation. The traditional biomaterial design consisted in fabricating inert biomaterials capable of stimulating osteogenesis; however, inconsistencies between the in vitro and in vivo results were reported. This led to a shift in the development of biomaterials towards implants with osteoimmunomodulatory properties. By endowing the orthopedic biomaterials with favorable osteoimmunomodulatory properties, a desired immune response can be triggered in order to obtain a proper bone regeneration process. In this context, various approaches, such as the modification of chemical/structural characteristics or the incorporation of bioactive molecules, have been employed in order to modulate the crosstalk with the immune cells. The current review provides an overview of recent developments in such applied strategies.

scholarly journals In Vivo Imaging and Morphometry of the Human Pre-Descemet's Layer and Endothelium With Ultrahigh-Resolution Optical Coherence Tomography

2016 ◽  
Vol 57 (6) ◽  
pp. 2782 ◽  
Author(s):  
Kostadinka Bizheva ◽  
Lacey Haines ◽  
Erik Mason ◽  
Benjamin MacLellan ◽  
Bingyao Tan ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
In Vivo Imaging ◽  
Optical Coherence ◽  
Ultrahigh Resolution

Severe myocardial dysfunction induced by ventricular remodeling in aging rat hearts

1990 ◽  
Vol 259 (4) ◽  
pp. H1086-H1096 ◽  
Author(s):  
J. M. Capasso ◽  
T. Palackal ◽  
G. Olivetti ◽  
P. Anversa
Keyword(s):  
Ventricular Remodeling ◽  
Volume Fraction ◽  
Diastolic Pressure ◽  
Structural Characteristics ◽  
Myocardial Dysfunction ◽  
Pressure Rise ◽  
Wall Stress ◽  
Left Ventricular ◽  
Cross Sectional

To determine if aging engenders alterations in the functional properties of the myocardium and ventricular remodeling, the hemodynamic performance and structural characteristics of the left ventricle of male Fischer 344 rats at 4, 12, 20, and 29 mo of age were studied by quantitative physiology and morphology. In vivo assessment of cardiac pump function showed no change up to 20 mo, whereas left ventricular end-diastolic pressure was increased at 29 mo. Moreover, peak rates of pressure rise and decay, stroke volume, ejection fraction, and cardiac output were depressed at the later age interval, demonstrating the presence of ventricular failure at this time. The measurements of chamber size and wall thickness showed that ventricular end-diastolic and end-systolic volumes progressively increased with age with the greatest change occurring at 20-29 mo. Aging was also accompanied by a marked augmentation in the volume fraction of fibrotic areas in the ventricular myocardium that was due to an increase in their number and cross-sectional area with time. These architectural rearrangements, in combination with the abnormalities in ventricular function, resulted in an elevation in the volume of wall stress throughout the cardiac cycle. Wall stress increased by 64, 44, and 50% from 4 to 12, 12 to 20, and 20 to 29 mo of age. In conclusion, aging leads to a continuous rise in wall stress that is not normalized by ventricular remodeling. These two independent processes appear to be responsible for the onset of heart failure in the senescent rat.

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