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Journal of Biomedical Optics

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https://www.readbyqxmd.com/read/29352564/optical-metabolic-imaging-of-irradiated-rat-heart-exposed-to-ischemia-reperfusion-injury
#1
Mette Funding la Cour, Shima Mehrvar, James S Heisner, Mohammad Masoudi Motlagh, Meetha Medhora, Mahsa Ranji, Amadou K S Camara
Whole thoracic irradiation (WTI) is known to cause deterioration in cardiac function. Whether irradiation predisposes the heart to further ischemia and reperfusion (IR) injury is not well known. The aim of this study is to examine the susceptibility of rat hearts to IR injury following a single fraction of 15 Gy WTI and to investigate the role of mitochondrial metabolism in the differential susceptibility to IR injury. After day 35 of irradiation, ex vivo hearts from irradiated and nonirradiated rats (controls) were exposed to 25-min global ischemia followed by 60-min IR, or hearts were perfused without IR for the same protocol duration [time controls (TC)]...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29349952/estimation-of-cerebral-metabolic-rate-of-oxygen-consumption-using-combined-multiwavelength-photoacoustic-microscopy-and-doppler-microultrasound
#2
Yan Jiang, Roger Zemp
The metabolic rate of oxygen consumption is an important metric of tissue oxygen metabolism and is especially critical in the brain, yet few methods are available for measuring it. We use a custom combined photoacoustic-microultrasound system and demonstrate cerebral oxygen consumption estimation in vivo. In particular, the cerebral metabolic rate of oxygen consumption was estimated in a murine model during variation of inhaled oxygen from hypoxia to hyperoxia. The hypothesis of brain autoregulation was confirmed with our method even though oxygen saturation and flow in vessels changed...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29349951/tissue-perfusion-rate-estimation-with-compression-based-photoacoustic-ultrasound-imaging
#3
Min Choi, A M James Shapiro, Roger Zemp
Tissue perfusion is essential for transporting blood oxygen and nutrients. Measurement of tissue perfusion rate would have a significant impact in clinical and preclinical arenas. However, there are few techniques to image this important parameter and they typically require contrast agents. A label-free methodology based on tissue compression and imaging with a high-frequency photoacoustic-ultrasound system is introduced for estimating and visualizing tissue perfusion rates. Experiments demonstrate statistically significant differences in depth-resolved perfusion rates in a human subject with various temperature exposure conditions...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29341543/improved-axial-point-spread-function-in-a-two-frequency-laser-scanning-confocal-fluorescence-microscope
#4
Jheng-Syong Wu, Yung-Chin Chung, Jun-Jei Chien, Chien Chou
A two-frequency laser scanning confocal fluorescence microscope (TF-LSCFM) based on intensity modulated fluorescence signal detection was proposed. The specimen-induced spherical aberration and scattering effect were suppressed intrinsically, and high image contrast was presented due to heterodyne interference. An improved axial point spread function in a TF-LSCFM compared with a conventional laser scanning confocal fluorescence microscope was demonstrated and discussed.
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29341542/intrinsic-fluorescence-for-cervical-precancer-detection-using-polarized-light-based-in-house-fabricated-portable-device
#5
Bharat Lal Meena, Pankaj Singh, Amar Nath Sah, Kiran Pandey, Asha Agarwal, Chayanika Pantola, Asima Pradhan
An in-house fabricated portable device has been tested to detect cervical precancer through the intrinsic fluorescence from human cervix of the whole uterus in a clinical setting. A previously validated technique based on simultaneously acquired polarized fluorescence and polarized elastic scattering spectra from a turbid medium is used to extract the intrinsic fluorescence. Using a diode laser at 405 nm, intrinsic fluorescence of flavin adenine dinucleotide, which is the dominant fluorophore and other contributing fluorophores in the epithelium of cervical tissue, has been extracted...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29341541/radiotherapy-fiber-dosimeter-probes-based-on-silver-only-coated-hollow-glass-waveguides
#6
Arash Darafsheh, Jeffrey E Melzer, James A Harrington, Alireza Kassaee, Jarod C Finlay
Manifestation of Čerenkov radiation as a contaminating signal is a significant issue in radiation therapy dose measurement by fiber-coupled scintillator dosimeters. To enhance the scintillation signal transmission while minimizing Čerenkov radiation contamination, we designed a fiber probe using a silver-only coated hollow waveguide (HWG). The HWG with scintillator inserted in its tip, embedded in tissue-mimicking phantoms, was irradiated with clinical electron and photon beams generated by a medical linear accelerator...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29322749/time-reversed-ultrasonically-encoded-optical-focusing-through-highly-scattering-ex-vivo-human-cataractous-lenses
#7
Yan Liu, Yuecheng Shen, Haowen Ruan, Frank L Brodie, Terence T W Wong, Changhuei Yang, Lihong V Wang
Normal development of the visual system in infants relies on clear images being projected onto the retina, which can be disrupted by lens opacity caused by congenital cataract. This disruption, if uncorrected in early life, results in amblyopia (permanently decreased vision even after removal of the cataract). Doctors are able to prevent amblyopia by removing the cataract during the first several weeks of life, but this surgery risks a host of complications, which can be equally visually disabling. Here, we investigated the feasibility of focusing light noninvasively through highly scattering cataractous lenses to stimulate the retina, thereby preventing amblyopia...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29318813/red-fluorescence-of-dental-biofilm-as-an-indicator-for-assessing-the-efficacy-of-antimicrobials
#8
Eun-Song Lee, Elbert de Josselin de Jong, Hoi-In Jung, Baek-Il Kim
The study aimed to determine whether the red fluorescence (RF) of a dental microcosm biofilm as measured with quantitative light-induced fluorescence (QLF) technology is useful for assessing the efficacy of antimicrobials. Dental microcosm biofilms were formed on bovine enamel discs and grown under 0.3% sucrose challenge and treated with chlorhexidine (CHX) solutions at different concentrations (0.05%, 0.1%, and 0.5%) plus a negative control [sterile distilled water (DW)] twice daily for 7 days. The biofilms were photographed using a QLF-digital system to evaluate the RF by calculating the red/green ratio, and pH values of the medium were measured daily...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29318812/detection-and-characterization-of-early-plaque-formations-by-raman-probe-spectroscopy-and-optical-coherence-tomography-an-in-vivo-study-on-a-rabbit-model
#9
Christian Matthäus, Sebastian Dochow, Kokila D Egodage, Bernd F Romeike, Bernhard R Brehm, Jürgen Popp
Intravascular imaging techniques provide detailed specification about plaque appearance and morphology, but cannot deliver information about the biochemical composition of atherosclerotic plaques. As the biochemical composition is related to the plaque type, important aspects such as the risk of a plaque rupture and treatment are still difficult to assess. Currently, various spectroscopic techniques are tested for potential applications for the chemical analysis of plaque depositions. Here, we employ Raman spectroscopy in combination with optical coherence tomography (OCT) for the characterization of plaques on rabbits in vivo...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29313325/development-of-a-mirna-surface-enhanced-raman-scattering-assay-using-benchtop-and-handheld-raman-systems
#10
Monika Schechinger, Haley Marks, Andrea Locke, Mahua Choudhury, Gerard Cote
DNA-functionalized nanoparticles, when paired with surface-enhanced Raman spectroscopy (SERS), can rapidly detect microRNA. However, widespread use of this approach is hindered by drawbacks associated with large and expensive benchtop Raman microscopes. MicroRNA-17 (miRNA-17) has emerged as a potential epigenetic indicator of preeclampsia, a condition that occurs during pregnancy. Biomarker detection using an SERS point-of-care device could enable prompt diagnosis and prevention as early as the first trimester...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29313324/improved-spectrometer-microscope-for-quantitative-fluorescence-resonance-energy-transfer-measurement-based-on-simultaneous-spectral-unmixing-of-excitation-and-emission-spectra
#11
Fangrui Lin, Mengyan Du, Fangfang Yang, Lichun Wei, Tongsheng Chen
Based on our recently developed quantitative fluorescence resonance energy transfer (FRET) measurement method using simultaneous spectral unmixing of excitation and emission spectra (ExEm-spFRET), we here set up an improved spectrometer-microscope (SM) for implementing modified ExEm-spFRET (mExEm-spFRET), in which a system correction factor (fsc) is introduced. Our SM system is very stable for at least six months. Implementation of mExEm-spFRET with four or two excitation wavelengths on SM for single living cells expressing different FRET constructs obtained consistent FRET efficiency (E) and acceptor-donor concentration ratio (Rc) values...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29313323/modulus-design-multiwavelength-polarization-microscope-for-transmission-mueller-matrix-imaging
#12
Jialing Zhou, Honghui He, Zhenhua Chen, Ye Wang, Hui Ma
We have developed a polarization microscope based on a commercial transmission microscope. We replace the halogen light source by a collimated LED light source module of six different colors. We use achromatic polarized optical elements that can cover the six different wavelength ranges in the polarization state generator (PSG) and polarization state analyzer (PSA) modules. The dual-rotating wave plate method is used to measure the Mueller matrix of samples, which requires the simultaneous rotation of the two quarter-wave plates in both PSG and PSA at certain angular steps...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29313322/comparing-three-dimensional-serial-optical-coherence-tomography-histology-to-mri-imaging-in-the-entire-mouse-brain
#13
Alexandre Castonguay, Joël Lefebvre, Frédéric Lesage, Philippe Pouliot
An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5)  μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29302956/biomedical-optics-scientific-community
#14
Brian W Pogue
The new Editor-in-Chief, Brian Pogue, gives an overview of the biomedical optics community.
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29302955/ion-imprinted-nanoparticles-for-the-concurrent-estimation-of-pb-ii-and-cu-ii-ions-over-a-two-channel-surface-plasmon-resonance-based-fiber-optic-platform
#15
Anand Mohan Shrivastav, Banshi D Gupta
We report the design, fabrication, and characterization of an optical fiber sensor based on the surface plasmon resonance (SPR) technique for the simultaneous determination of lead (Pb) and copper (Cu) metal ions in aqueous samples. Two cascade channels over a single optical fiber are fabricated by removing cladding from two well-separated regions of the fiber. SPR working as a transducing mechanism for the sensor is realized by coating thin films of copper and silver over unclad cores of channel I and channel II, respectively...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29302954/correction-of-motion-artifacts-in-endoscopic-optical-coherence-tomography-and-autofluorescence-images-based-on-azimuthal-en-face-image-registration
#16
Elham Abouei, Anthony M D Lee, Hamid Pahlevaninezhad, Geoffrey Hohert, Michelle Cua, Pierre Lane, Stephen Lam, Calum MacAulay
We present a method for the correction of motion artifacts present in two- and three-dimensional in vivo endoscopic images produced by rotary-pullback catheters. This method can correct for cardiac/breathing-based motion artifacts and catheter-based motion artifacts such as nonuniform rotational distortion (NURD). This method assumes that en face tissue imaging contains slowly varying structures that are roughly parallel to the pullback axis. The method reduces motion artifacts using a dynamic time warping solution through a cost matrix that measures similarities between adjacent frames in en face images...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29302953/utilization-of-targeted-near-infrared-molecular-imaging-to-improve-pulmonary-metastasectomy-of-osteosarcomas
#17
Jarrod D Predina, Andrew Newton, Charuhas Deshpande, Philip Low, Sunil Singhal
Pulmonary metastasectomy for osteosarcoma provides a select group of patients an opportunity for long-term survival and possible cure. Unfortunately, a complete metastasectomy is challenging due an inability to accurately identify lesions that lay below the threshold of preoperative imaging or intraoperative visual and tactile inspection. Growing evidence suggests that osteosarcomas express a number of unique molecular markers, including the folate receptor alpha. In this case report, we describe the application of a folate receptor-targeted, near-infrared optical contrast agent (OTL38) to improve osteosarcoma localization during minimally invasive pulmonary resection...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29297212/low-cost-oblique-illumination-an-image-quality-assessment
#18
Jesus Ruiz-Santaquiteria, Jose Luis Espinosa-Aranda, Oscar Deniz, Carlos Sanchez, Maria Borrego-Ramos, Saul Blanco, Gabriel Cristobal, Gloria Bueno
We study the effectiveness of several low-cost oblique illumination filters to improve overall image quality, in comparison with standard bright field imaging. For this purpose, a dataset composed of 3360 diatom images belonging to 21 taxa was acquired. Subjective and objective image quality assessments were done. The subjective evaluation was performed by a group of diatom experts by psychophysical test where resolution, focus, and contrast were assessed. Moreover, some objective nonreference image quality metrics were applied to the same image dataset to complete the study, together with the calculation of several texture features to analyze the effect of these filters in terms of textural properties...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29297211/pupil-size-stability-of-the-cubic-phase-mask-solution-for-presbyopia
#19
Citlalli Almaguer, Eva Acosta, Justo Arines
Presbyopia correction involves different types of studies such as lens design, clinical study, and the development of objective metrics, such as the visual Strehl ratio. Different contact lens designs have been proposed for presbyopia correction, but performance depends on pupil diameter. We will analyze the potential use of a nonsymmetrical element, a cubic phase mask (CPM) solution, to develop a contact or intraocular lens whose performance is nearly insensitive to changes in pupil diameter. We will show the through focus optical transfer function of the proposed element for different pupil diameters ranging from 3 to 7 mm...
January 2018: Journal of Biomedical Optics
https://www.readbyqxmd.com/read/29297210/transmission-versus-reflectance-spectroscopy-for-quantitation
#20
Craig M Gardner
The objective of this work was to compare the accuracy of analyte concentration estimation when using transmission versus diffuse reflectance spectroscopy of a scattering medium. Monte Carlo ray tracing of light through the medium was used in conjunction with pure component absorption spectra and Beer-Lambert absorption along each ray's pathlength to generate matched sets of pseudoabsorbance spectra, containing water and six analytes present in skin. PLS regression models revealed an improvement in accuracy when using transmission compared to reflectance for a range of medium thicknesses and instrument noise levels...
January 2018: Journal of Biomedical Optics
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