Nanosensitive optical coherence tomography for detecting structural changes in stem cells.

Mesenchymal stromal cells (MSCs) are adult stem cells that have been widely investigated for their potential to regenerate damaged and diseased tissues. Multiple pre-clinical studies and clinical trials have demonstrated a therapeutic response following treatment with MSCs for various pathologies, including cardiovascular, neurological and orthopaedic diseases. The ability to functionally track cells following administration in vivo is pivotal to further elucidating the mechanism of action and safety profile of these cells.

Development of controlled nanosphere lithography technology.

This work is devoted to the development of nanosphere lithography (NSL) technology, which is a low-cost and efficient method to form nanostructures for nanoelectronics, as well as optoelectronic, plasmonic and photovoltaic applications. Creating a nanosphere mask by spin-coating is a promising, but not sufficiently studied method, requiring a large experimental base for different sizes of nanospheres. So, in this work, we investigated the influence of the technological parameters of NSL by spin-coating on the substrate coverage area by a monolayer of nanospheres with a diameter of 300 nm.

Skin cancer margin detection using nanosensitive optical coherence tomography and a comparative study with confocal microscopy.

Excision biopsy and histology represent the gold standard for morphological investigation of the skin, in particular for cancer diagnostics. Nevertheless, a biopsy may alter the original morphology, usually requires several weeks for results, is non-repeatable on the same site and always requires an iatrogenic trauma. Hence, diagnosis and clinical management of diseases may be substantially improved by new non-invasive imaging techniques.

OES diagnostics as a universal technique to control the Si etching structures profile in ICP.

In this work, we demonstrate the high efficiency of optical emission spectroscopy to estimate the etching profile of silicon structures in SF/CF/O plasma. The etching profile is evaluated as a ratio of the emission intensity of the oxygen line (778.1 nm) to the fluorine lines (685.

Accessing depth-resolved high spatial frequency content from the optical coherence tomography signal.

Optical coherence tomography (OCT) is a rapidly evolving technology with a broad range of applications, including biomedical imaging and diagnosis. Conventional intensity-based OCT provides depth-resolved imaging with a typical resolution and sensitivity to structural alterations of about 5-10 microns. It would be desirable for functional biological imaging to detect smaller features in tissues due to the nature of pathological processes.

Characterization of nanosensitive multifractality in submicron scale tissue morphology and its alteration in tumor progression (Erratum).

An error in the 2nd author's name is corrected.

Characterization of nanosensitive multifractality in submicron scale tissue morphology and its alteration in tumor progression.

Significance: Assessment of disease using optical coherence tomography is an actively investigated problem, owing to many unresolved challenges in early disease detection, diagnosis, and treatment response monitoring. The early manifestation of disease or precancer is typically associated with subtle alterations in the tissue dielectric and ultrastructural morphology. In addition, biological tissue is known to have ultrastructural multifractality.

High-temperature etching of SiC in SF/O inductively coupled plasma.

In this work, we demonstrate an effective way of deep (30 µm depth), highly oriented (90° sidewall angle) structures formation with sub-nanometer surface roughness (R = 0.7 nm) in silicon carbide (SiC). These structures were obtained by dry etching in SF/O inductively coupled plasma (ICP) at increased substrate holder temperatures.

Nanosensitive optical coherence tomography to assess wound healing within the cornea.

Optical coherence tomography (OCT) is a non-invasive depth resolved optical imaging modality, that enables high resolution, cross-sectional imaging in biological tissues and materials at clinically relevant depths. Though OCT offers high resolution imaging, the best ultra-high-resolution OCT systems are limited to imaging structural changes with a resolution of one micron within very limited depth. Nanosensitive OCT (nsOCT) is a recently developed technique that is capable of providing enhanced sensitivity of OCT to structural changes.

Fast and Controllable Synthesis of Core-Shell FeO-C Nanoparticles by Aerosol CVD.

A method for simple and fast (30-60 s) synthesis of spherical "FeO core-carbon shell" structures by atmospheric pressure aerosol pyrolysis of benzoic acid in dimethylformamide solutions containing dispersed FeO nanoparticles is described. It has been experimentally shown that it is possible to control both the size of the core-shell particles and the size of FeO grains and their amount in the particle core by the variation of benzoic acid concentration in solution and using pre-stabilized by mannitol iron oxide nanoparticles. It has been found that particles with an average size of 250-350 nm are formed at the concentration of benzoic acid in the range 0.

Noninvasive detection of nanoscale structural changes in cornea associated with cross-linking treatment.

Corneal cross-linking (CXL) using ultraviolet-A (UVA) irradiation with a riboflavin photosensitizer has grown from an interesting concept to a practical clinical treatment for corneal ectatic diseases globally, such as keratoconus. To characterize the corneal structural changes, existing methods such as X-ray microscopy, transmission electron microscopy, histology and optical coherence tomography (OCT) have been used. However, these methods have various drawbacks such as invasive detection, the impossibility for in vivo measurement, or limited resolution and sensitivity to structural alterations.

A Theory of Elastic/Plastic Plane Strain Pure Bending of FGM Sheets at Large Strain.

An efficient analytical/numerical method has been developed and programmed to predict the distribution of residual stresses and springback in plane strain pure bending of functionally graded sheets at large strain, followed by unloading. The solution is facilitated by using a Lagrangian coordinate system. The study is concentrated on a power law through thickness distribution of material properties.

Characterization of an amplified piezoelectric actuator for multiple reference optical coherence tomography: erratum.

This erratum is submitted to correct information regarding Fig. 8 of Appl. Opt.

Characterization of an amplified piezoelectric actuator for multiple-reference optical coherence tomography.

The characterization of an amplified piezoelectric actuator (APA) as a new axial scanning method for multiple-reference optical coherence tomography (MR-OCT) is described. MR-OCT is a compact optical imaging device based on a recirculating reference-arm-scanning optical delay using a partial mirror that can enhance the imaging depth range by more than 10 times the reference mirror's scanning amplitude. The scanning amplitude of the used APA was varied between 30 μm and 250 μm, depending on the scanning frequency of between 0.

Feasibility of correlation mapping optical coherence tomography angiographic technique using a 200 kHz vertical-cavity surface-emitting laser source for in vivo microcirculation imaging applications.

Optical coherence tomography (OCT) angiography is a well-established in vivo imaging technique to assess the overall vascular morphology of tissues and is an emerging field of research for the assessment of blood flow dynamics and functional parameters such as oxygen saturation. In this study, we present a modified scanning-based correlation mapping OCT using a 200 kHz high-speed swept-source OCT system operating at 1300 nm and demonstrate its wide field-imaging capability in ocular angiographic studies.

Label-free ultra-sensitive visualization of structure below the diffraction resolution limit.

For both fundamental study of biological processes and early diagnosis of diseases, information about nanoscale changes in tissue and cell structure is crucial. Nowadays, almost all currently known nanoscopy methods rely upon the contrast created by fluorescent stains attached to the object or molecule of interest. This causes limitations due to the impact of the label on the object and its environment, as well as its applicability in vivo, particularly in humans.

Simultaneous en-face imaging of multiple layers with multiple reference optical coherence tomography.

A technique based on multiple reference optical coherence tomography (MR-OCT) is proposed for simultaneous imaging at multiple depths. The technique has been validated by imaging a reference sample and a fingerprint in-vivo. The principle of scanning multiple selected layers is shown by imaging a partial fingerprint with 200×200×200 voxels of 3×3×0.

TOF MS Investigation of Nickel Oxide CVD.

NiO layers were deposited by metal-organic chemical vapor deposition using bis-(ethylcyclopentadienyl) nickel (EtCp)Ni and oxygen or ozone. As a continuation of kinetic study of NiO MOCVD the gas-phase, transformations of (EtCp)Ni were studied in the temperature range of 380-830 K. Time of reactions corresponding to the residence time of the gas stream in hot zone of the reactor was about 0.

Functional imaging for regenerative medicine.

In vivo imaging is a platform technology with the power to put function in its natural structural context. With the drive to translate stem cell therapies into pre-clinical and clinical trials, early selection of the right imaging techniques is paramount to success. There are many instances in regenerative medicine where the biological, biochemical, and biomechanical mechanisms behind the proposed function of stem cell therapies can be elucidated by appropriate imaging.

In vivo correlation mapping microscopy.

To facilitate regular assessment of the microcirculation in vivo, noninvasive imaging techniques such as nailfold capillaroscopy are required in clinics. Recently, a correlation mapping technique has been applied to optical coherence tomography (OCT), which extends the capabilities of OCT to microcirculation morphology imaging. This technique, known as correlation mapping optical coherence tomography, has been shown to extract parameters, such as capillary density and vessel diameter, and key clinical markers associated with early changes in microvascular diseases.

Chain Assemblies from Nanoparticles Synthesized by Atmospheric Pressure Plasma Enhanced Chemical Vapor Deposition: The Computational View.

This article refers to the computational study of nanoparticle self-organization on the solid-state substrate surface with consideration of the experimental results, when nanoparticles were synthesised during atmospheric pressure plasma enhanced chemical vapor deposition (AP-PECVD). The experimental study of silicon dioxide nanoparticle synthesis by AP-PECVD demonstrated that all deposit volume consists of tangled chains of nanoparticles. In certain cases, micron-sized fractals are formed from tangled chains due to deposit rearrangement.

Novel approach for label free super-resolution imaging in far field.

Progress in the emerging areas of science and technology, such as bio- and nano-technologies, depends on development of corresponding techniques for imaging and probing the structures with high resolution. Recently, the far field diffraction resolution limit in the optical range has been circumvented and different methods of super-resolution optical microscopy have been developed. The importance of this breakthrough achievement has been recognized by Nobel Prize for Chemistry in 2014.

STIM2 protects hippocampal mushroom spines from amyloid synaptotoxicity.

Background: Alzheimer disease (AD) is a disease of lost memories. Mushroom postsynaptic spines play a key role in memory storage, and loss of mushroom spines has been proposed to be linked to memory loss in AD. Generation of amyloidogenic peptides and accumulation of amyloid plaques is one of the pathological hallmarks of AD.

Nano-sensitive optical coherence tomography.

Depth resolved label-free detection of structural changes with nanoscale sensitivity is an outstanding problem in the biological and physical sciences and has significant applications in both the fundamental research and healthcare diagnostics arenas. Here we experimentally demonstrate a novel label-free depth resolved sensing technique based on optical coherence tomography (OCT) to detect structural changes at the nanoscale. Structural components of the 3D object, spectrally encoded in the remitted light, are transformed from the Fourier domain into each voxel of the 3D OCT image without compromising sensitivity.

Investigation of nanoscale structural alterations of cell nucleus as an early sign of cancer.

Background: The cell and tissue structural properties assessed with a conventional bright-field light microscope play a key role in cancer diagnosis, but they sometimes have limited accuracy in detecting early-stage cancers or predicting future risk of cancer progression for individual patients (i.e., prognosis) if no frank cancer is found.