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multiphoton imaging

Anurag Mishra, Yuanyuan Jiang, Sheryl Roberts, Vasilis Ntziachristos, Gil Gregor Westmeyer
Photoacoustic imaging (PAI) is an attractive imaging modality that can volumetrically map the distribution of photoabsorbing molecules with deeper tissue penetration than multiphoton microscopy. To enable dynamic sensing of divalent cations via PAI, we have engineered a new reversible near infrared probe that is more sensitive to calcium as compared to other biologically relevant cations. The metallochromic compound showed a strong reduction of its peak absorbance at 765 nm upon addition of calcium ions that was translated into robust signal changes in photoacoustic images...
October 25, 2016: Analytical Chemistry
Markus Seeger, Angelos Karlas, Dominik Soliman, Jaroslav Pelisek, Vasilis Ntziachristos
Carotid artery atherosclerosis is a main cause of stroke. Understanding atherosclerosis biology is critical in the development of targeted prevention and treatment strategies. Consequently, there is demand for advanced tools investigating atheroma pathology. We consider hybrid optoacoustic and multiphoton microscopy for the integrated and complementary interrogation of plaque tissue constituents and their mutual interactions. Herein, we visualize human carotid plaque using a hybrid multimodal imaging system that combines optical resolution optoacoustic (photoacoustic) microscopy, second and third harmonic generation microscopy, and two-photon excitation fluorescence microscopy...
September 2016: Photoacoustics
Qian Zhao, Xueqi Chen, Yun Zhou
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, causing changes in memory, thinking, and other dysfunction of brain functions. More and more people are suffering from the disease. Early neuroimaging techniques of AD are needed to develop. This review provides a preliminary summary of the various neuroimaging techniques that have been explored for in vivo imaging of AD. Recent advances in magnetic resonance (MR) techniques, such as functional MR imaging (fMRI) and diffusion MRI, give opportunities to display not only anatomy and atrophy of the medial temporal lobe, but also at microstructural alterations or perfusion disturbance within the AD lesions...
March 2016: Brain Informatics
Pouriska B Kivanany, Kyle C Grose, W Matthew Petroll
Extracellular matrix (ECM) supplies both physical and chemical signals to keratocytes which can impact their differentiation to fibroblasts and/or myofibroblasts. It also provides a substrate through which they migrate during wound repair. We have previously shown that following transcorneal freeze injury (FI), migrating corneal fibroblasts align parallel to the stromal lamellae during wound repopulation. In this study, we compare cell and ECM patterning both within and on top of the stroma at different time points following lamellar keratectomy (LK) in the rabbit...
October 9, 2016: Experimental Eye Research
Yosuke Shimo, Tomohiro Uchimura
Multiphoton ionization time-of-flight mass spectrometry was applied to the measurement of an oil-in-water emulsion that contained toluene as a dispersed phase. Before the measurement, the sample was sufficiently creamed, and then stirred for a short period of time for dispersion. As a result, several intense spikes appeared on the time profile constructed from the peak area for toluene. In the present study, an optical microscope was used to observe the capillary column for sample introduction, and small toluene droplets along with their aggregates were found in the images of the emulsion flowing through the capillary...
2016: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Kristen Zuraski, Daniel Thomas Kwasniewski, Amit Kumar Samanta, Hanna Reisler
The vibrational predissociation of the HCl-(H2O)3 tetramer, the largest HCl-(H2O)n cluster for which HCl is not predicted to be ionized, is reported. This work focuses on the predissociation pathway giving rise to H2O + HCl-(H2O)2 following IR laser excitation of the H-bonded OH stretch fundamental. H2O fragments are monitored state-selectively by 2+1 resonance enhanced multiphoton ionization (REMPI) combined with time-of-flight mass spectrometry (TOF-MS). Velocity map images of H2O in selected rotational levels are used to determine translational energy distributions from which the internal energy distributions in the pair-correlated cofragments are derived...
October 10, 2016: Journal of Physical Chemistry Letters
Pavle Glodic, Dimitris Zaouris, Peter C Samartzis, Arnar Hafliðason, Ágúst Kvaran
Analysis of mass resolved spectra as well as velocity map images derived from resonance enhanced multiphoton ionization (REMPI) of HBr via resonance excitations to mixed Rydberg (6pπ (3)Σ(-)(v' = 0)) and valence (ion-pair) (V (1)Σ(+)(v' = m + 17)) states allows characterization of the effect of a triplet-to-singlet state interaction on further photoexcitation and photoionization processes. The analysis makes use of rotational spectra line shifts, line intensity alterations, kinetic energy release spectra as well as angular distributions...
September 21, 2016: Physical Chemistry Chemical Physics: PCCP
Virginia Brancato, Alessandro Garziano, Filomena Gioiella, Francesco Urciuolo, Giorgia Imparato, Valeria Panzetta, Sabato Fusco, Paolo A Netti
: We fabricated three-dimensional microtissues with the aim to replicate in vitro the composition and the functionalities of the tumor microenvironment. By arranging either normal fibroblasts (NF) or cancer-activated fibroblasts (CAF) in two different three dimensional (3D) configurations, two kinds of micromodules were produced: spheroids and microtissues. Spheroids were obtained by means of the traditional cell aggregation technique resulting in a 3D model characterized by high cell density and low amount of extracellular proteins...
October 6, 2016: Acta Biomaterialia
Chih-Ju Lin, Feng-Chieh Li, Yu-Yang Lee, Te-Yu Tseng, Wei-Liang Chen, Vladimir Hovhannisyan, Ning Kang, Nicholas G Horton, Shu-Jen Chiang, Chris Xu, Hsuan-Shu Lee, Chen-Yuan Dong
Hepatobiliary metabolism is one of the major functions of the liver. However, little is known of the relationship between the physiological location of the hepatocytes and their metabolic potential. By the combination of time-lapse multiphoton microscopy and first order kinetic constant image analysis, the hepatocellular metabolic rate of the model compound 6-carboxyfluorescein diacetate (6-CFDA) is quantified at the single cell level. We found that the mouse liver can be divided into three zones, each with distinct metabolic rate constants...
September 1, 2016: Biomedical Optics Express
Ilyas Saytashev, Rachel Glenn, Gabrielle A Murashova, Sam Osseiran, Dana Spence, Conor L Evans, Marcos Dantus
Red blood cells (RBC) in two-photon excited fluorescence (TPEF) microscopy usually appear as dark disks because of their low fluorescent signal. Here we use 15fs 800nm pulses for TPEF, 45fs 1060nm pulses for three-photon excited fluorescence, and third harmonic generation (THG) imaging. We find sufficient fluorescent signal that we attribute to hemoglobin fluorescence after comparing time and wavelength resolved spectra of other expected RBC endogenous fluorophores: NADH, FAD, biliverdin, and bilirubin. We find that both TPEF and THG microscopy can be used to examine erythrocyte morphology non-invasively without breaching a blood storage bag...
September 1, 2016: Biomedical Optics Express
Yuan Zhao, Mingyu Sheng, Lin Huang, Shuo Tang
We have developed a fiber-optic multiphoton microscopy (MPM) system with handheld probe using femtosecond fiber laser. Here we present the detailed optical design and analysis of the handheld probe. The optical systems using Lightpath 352140 and 352150 as objective lens were analyzed. A custom objective module that includes Lightpath 355392 and two customized corrective lenses was designed. Their performances were compared by wavefront error, field curvature, astigmatism, F-θ error, and tolerance in Zemax simulation...
September 1, 2016: Biomedical Optics Express
Yeoreum Yoon, Seung Hwan Jeon, Yong Hyun Park, Won Hyuk Jang, Ji Youl Lee, Ki Hean Kim
Preservation of prostatic nerves is critical to recovery of a man's sexual potency after radical prostatectomy. A real-time imaging method of prostatic nerves will be helpful for nerve-sparing radical prostatectomy (NSRP). Polarization-sensitive optical coherence tomography (PS-OCT), which provides both structural and birefringent information of tissue, was applied for detection of prostatic nerves in both rat and human prostate specimens, ex vivo. PS-OCT imaging of rat prostate specimens visualized highly scattering and birefringent fibrous structures superficially, and these birefringent structures were confirmed to be nerves by histology or multiphoton microscopy (MPM)...
September 1, 2016: Biomedical Optics Express
Sylvia M Bardet, Lynn Carr, Malak Soueid, Delia Arnaud-Cormos, Philippe Leveque, Rodney P O'Connor
Despite the biomedical advances of the last century, many cancers including glioblastoma are still resistant to existing therapies leaving patients with poor prognoses. Nanosecond pulsed electric fields (nsPEF) are a promising technology for the treatment of cancer that have thus far been evaluated in vitro and in superficial malignancies. In this paper, we develop a tumor organoid model of glioblastoma and apply intravital multiphoton microscopy to assess their response to nsPEFs. We demonstrate for the first time that a single 10 ns, high voltage electric pulse (35-45 kV/cm), collapses the perfusion of neovasculature, and also alters the diameter of capillaries and larger vessels in normal tissue...
October 4, 2016: Scientific Reports
Erica R Pursell, Daniela Vélez-Rendón, Daniela Valdez-Jasso
In a MCT induced-PAH rat animal model, the dynamic stress-strain relation was investigated in the circumferential and axial direction using a linear elastic response model within the quasi-linear viscoelasticity theory framework. Right and left pulmonary arterial segments (RPA, LPA) were mechanically tested in a tubular biaxial device at the early stage (1 week post-MCT treatment) and at the advanced stage of the disease (4 weeks post-MCT treatment). The vessels were tested circumferentially at the in vivo axial length with matching in vivo measured pressure ranges...
September 29, 2016: Journal of Biomechanical Engineering
Henrike Peuschel, Thomas Ruckelshausen, Silke Kiefer, Yuliya Silina, Annette Kraegeloh
BACKGROUND: Quantum dots (QDs) have great potential as fluorescent labels but cytotoxicity relating to extra- and intracellular degradation in biological systems has to be addressed prior to biomedical applications. In this study, human intestinal cells (Caco-2) grown on transwell membranes were used to study penetration depth, intracellular localization, translocation and cytotoxicity of CdSe/ZnS QDs with amino and carboxyl surface modifications. The focus of this study was to compare the penetration depth of QDs in differentiated vs undifferentiated cells using confocal microscopy and image processing...
September 26, 2016: Journal of Nanobiotechnology
Haohua Tu, Yuan Liu, Dmitry Turchinovich, Marina Marjanovic, Jens Lyngsø, Jesper Lægsgaard, Eric J Chaney, Youbo Zhao, Sixian You, William L Wilson, Bingwei Xu, Marcos Dantus, Stephen A Boppart
The preparation, staining, visualization, and interpretation of histological images of tissue is well-accepted as the gold standard process for the diagnosis of disease. These methods were developed historically, and are used ubiquitously in pathology, despite being highly time and labor intensive. Here we introduce a unique optical imaging platform and methodology for label-free multimodal multiphoton microscopy that uses a novel photonic crystal fiber source to generate tailored chemical contrast based on programmable supercontinuum pulses...
August 2016: Nature Photonics
Sean C Warren, Youngchan Kim, James M Stone, Claire Mitchell, Jonathan C Knight, Mark A A Neil, Carl Paterson, Paul M W French, Chris Dunsby
This paper demonstrates multiphoton excited fluorescence imaging through a polarisation maintaining multicore fiber (PM-MCF) while the fiber is dynamically deformed using all-proximal detection. Single-shot proximal measurement of the relative optical path lengths of all the cores of the PM-MCF in double pass is achieved using a Mach-Zehnder interferometer read out by a scientific CMOS camera operating at 416 Hz. A non-linear least squares fitting procedure is then employed to determine the deformation-induced lateral shift of the excitation spot at the distal tip of the PM-MCF...
September 19, 2016: Optics Express
Takaharu Okada, Sonoko Takahashi, Azusa Ishida, Harumichi Ishigame
Multiphoton imaging has been utilized to analyze in vivo immune cell dynamics over the last 15 years. Particularly, it has deepened the understanding of how immune responses are organized by immune cell migration and interactions. In this review, we first describe the following technical advances in recent imaging studies that contributed to the new findings on the regulation of immune responses and inflammation. Improved multicolor imaging of immune cell behavior has revealed that their interactions are spatiotemporally coordinated to achieve efficient and long-term immunity...
September 22, 2016: Pflügers Archiv: European Journal of Physiology
L W Jiang, X F Wang, Z Y Wu, P H Lin, H P DU, S Wang, L H Li, N Fang, S M Zhuo, D Z Kang, J X Chen
Glioblastoma multiforme (GBM-WHO grade IV) is the most common and the most aggressive form of brain tumors in adults with the median survival of 10-12 months. The diagnostic detection of extracellular matrix (ECM) component in the tumour microenvironment is of prognostic value. In this paper, the fibrillar collagen deposition associated with vascular elements in GBM were investigated in the fresh specimens and unstained histological slices by using multiphoton microscopy (MPM) based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG)...
September 19, 2016: Journal of Microscopy
Amy M Holmes, Julian Lim, Hauke Studier, Michael S Roberts
The use of silver nanoparticles (Ag NPs) within the healthcare sector and consumer products is rapidly increasing. There are now a range of diverse-shaped Ag NPs that are commercially available and many of the products containing nanosilver are topically applied to human skin. Currently, there is limited data on the extent to which the antimicrobial efficacy and cytotoxicity of Ag NPs is related to their shape and how the shape of the Ag NPs affects their distribution in both intact and burn wounded human skin after topical application...
October 5, 2016: Nanotoxicology
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