Imaging Of Biological Objects Research Articles

Decomposition Technique for Bio-Transmittance Imaging Based on Attenuation Coefficient Matrix Inverse.

Human body tissue disease diagnosis will become more accurate if transmittance images, such as X-ray images, are separated according to each constituent tissue. This research proposes a new image decomposition technique based on the matrix inverse method for biological tissue images. The fundamental idea of this research is based on the fact that when k different monochromatic lights penetrate a biological tissue, they will experience different attenuation coefficients. Furthermore, the same happens when monochromatic light penetrates k different biological tissues, as they will also experience different attenuation coefficients. The various attenuation coefficients are arranged into a unique k×k-dimensional square matrix. k-many images taken by k-many different monochromatic lights are then merged into an image vector entity; further, a matrix inverse operation is performed on the merged image, producing N-many tissue thickness images of the constituent tissues. This research demonstrates that the proposed method effectively decomposes images of biological objects into separate images, each showing the thickness distributions of different constituent tissues. In the future, this proposed new technique is expected to contribute to supporting medical imaging analysis.

Possibilities of Multiphoton Microscopy in Semiconductor Nanomaterials Research

Multiphoton microscopy is the method using nonlinear optical effect which is two-photon absorption. It occurs when two identical photons are absorbed simultaneously. The photon energy should be around two times smaller than the photon energy for one-photon absorption. Thus, the excitation irradiation wavelength for multiphoton microscopy should be twice that for conventional confocal microscopy. Nowadays, multiphoton microscopy is widely used for biological research, but it is possible to apply this for non-biological materials studying, particularly, for solid-state materials and structures. Low-wavelength laser irradiation deep penetration, focusing and optical signal analysis possibility provides essential new challenges solving of hierarchical "smart" nanoparticles synthesis for target drug delivery, theranostics etc. In this paper we give an answer of some most popular questions about multiphoton microscopy. Nature and aspects of the multiphoton microscopy method were described. Advantages of this method in comparison with confocal microscopy method were shown. Multiphoton microscopy gives the best image contrast and the less photodamage and photobleaching of biological samples, and provides an opportunity of three-dimensional imaging of the biomaterials as well as the solid-state materials. Additionally, capabilities of this method for solid-state materials research were demonstrated by the porous silicon samples example. Also, multiphoton microscopy images of biological objects were shown.

Laser fragmentation of silicon microparticles in liquids for solution of biophotonics problems

The possibility of manufacturing silicon nanoparticles by picosecond laser fragmentation of silicon microparticles in water is analysed. It is shown that for fragmentation duration of 40 min, the dependence of the average sizes of particles on the initial mass concentration of the micropowder varied in the range of 0.5 – 12 mg mL−1 is nonmonotonic, with the maximum average size of 165 nm being achieved at a concentration of 5 mg mL−1. To explain the obtained result, the simulation of propagation of a focused laser beam in a scattering suspension of silicon microparticles is performed for their different mass concentrations. It is demonstrated that at concentrations not exceeding 5 mg mL−1, fragmentation occurs in the paraxial region of the beam when it propagates deep into the cuvette with a suspension, while at higher concentrations it occurs primarily in the superficial layer owing to strong extinction. Calculations results allow the experimental features of the formation of silicon nanoparticles to be explained. Spectrophotometry measurements on suspensions of nanoparticles obtained at the initial concentration of microparticles of 12 mg mL−1 are compared with the theoretical estimates of the absorption and scattering coefficients obtained in the framework of the Mie theory. Measured optical properties indicate the potential of using fragmented nanoparticles as scattering and/or absorbing contrast agents in optical imaging of biological objects.

Near-Field Microwave Tomography of Biological Tissues: Future Perspectives.

This overview shows the mapping of specific visualization techniques, depth assessment of the structure of the underlying tissues and used wavelengths of radiation. Medical imaging is currently one of the most dynamically developing areas of medical science. The main aim of the review is a systematization of information on the current status of the microwave imaging of biological objects, primarily of body tissues. The main options of microwave sensing of biological objects are analyzed. Two basic techniques for sensing differing evaluation parameters are characterized. They are microwave thermometry (passive) and near-field resonance imaging. The physical principles of microwave sensing application are discussed. It is shown that the resonant near-field microwave tomography allows visualization of the structure of biological tissues on the basis of the spatial distribution of their electrodynamic characteristics - permittivity and conductivity. Potential areas for this method in dermatology, including dermatooncology, are shown. The known results of applying the method to patients with dermatoses are given. The informativeness of the technology in the early diagnosis of melanoma is shown. The prospects of microwave diagnostics in combustiology, reconstructive and plastic surgery are demonstrated. Thus, microwave sensing is a modern, dynamically developing method of biophysical assessment of body tissues. There is a strong indication of the feasibility of application of microwave sensing in combustiology (in different periods of burn disease), as well as in reconstructive surgery. Further research in this and other areas of biomedicine will significantly expand the range of possibilities of modern technologies of visualization.

Soft‐Contact Acoustic Microgripper Based on a Controllable Gas–Liquid Interface for Biomicromanipulations (Small 49/2021)

Soft-Contact Acoustic Microgripper In the article number 2104579, Jixiao Liu, Tiejun Li, and co-workers utilize a controllable vibrating bubble gripper to realize noninvasive multi-micromanipulations. The gas-liquid interface oscillation excited by acoustic energy imposes coupled radiation force and drag force on the target micro-bioentities for capturing and transportation. The flow velocity gradient generated by the streaming flow is utilized to rotate the immobilized micro-object. It can be a powerful tool in 3D micromanipulation, 3D imaging of biological objects, and 3D cell mechanical properties analysis.

Coherent anti-Stokes Raman scattering microspectroscopy: an emerging technique for non-invasive optical assessment of a local bio-nano-environment.

Raman spectroscopy provides a non-invasive, chemically-specific optical imaging of biological objects without relying on endogenous labels. Nonlinear Raman spectroscopy allows non-invasive imaging at much faster speed with an improved spatial resolution and axial sectioning capability. In this report we propose a novel use of nonlinear Raman spectroscopy as a sensor of local nano-environment. Time-resolved coherent anti-Stokes Raman spectrograms are found to be sensitive to small variations of local structural changes, which are not normally observed using conventional Raman spectroscopy.

Current data processing strategies for cryo-electron tomography and subtomogram averaging.

Cryo-electron tomography (cryo-ET) can be used to reconstruct three-dimensional (3D) volumes, or tomograms, from a series of tilted two-dimensional images of biological objects in their near-native states in situ or in vitro. 3D subvolumes, or subtomograms, containing particles of interest can be extracted from tomograms, aligned, and averaged in a process called subtomogram averaging (STA). STA overcomes the low signal to noise ratio within the individual subtomograms to generate structures of the particle(s) of interest. In recent years, cryo-ET with STA has increasingly been capable of reaching subnanometer resolution due to improvements in microscope hardware and data processing strategies. There has also been an increase in the number and quality of software packages available to process cryo-ET data with STA. In this review, we describe and assess the data processing strategies available for cryo-ET data and highlight the recent software developments which have enabled the extraction of high-resolution information from cryo-ET datasets.

Non-scalable functions as biological object boundary models

This article considers the possibility of creating an algorithm for universal image preprocessing that would simplify its segmentation and is suitable for any type of medical or biological study methods. The authors propose a number of equally applicable functions that describe the changes in the parameters of a raster image along the normal to the border of an arbitrary biological object and at the same time doesn’t depend on the instrumental method of image acquisition. The work also determines the absence of any parametric adaptation as the boundary condition for reducing the subjective contribution to the final scientific and practical result. Methods. Based on the biological foundations, the following three simple mathematical expressions were chosen for changing brightness on the border of a biological object: All the functions participating in calculations were not scaled, their size corresponded to the coordinates expressed as raster image dots. The Pearson’s correlation without reliability assessment was used to describe the probabilities of the object’s border being present in the coordinate x=0, and to assess its affinity with properties of the proposed synthetic functions. The basis of functions was tested using digital images of three fundamentally-different objects obtained with different physical detectors: sagittal section of the MRI scan of human head capturing the hippocampus area (Siemens Magnetom Skyra, Germany); optical section of eye cornea (Pentacam, Oculus, Japan); image of transverse histological section of human skin stained with hematoxylin and eosin obtained with microscope (Olympus BX65, Olympus, Japan). In addition, practical evaluation of the applicability of the developed approach was done by processing 100 two-dimensional images of different arbitrarily selected brain MRI sections. A field of probability of the presence of “biological border” in each dot of the image was built for each image. Results. The best affinity — with significant outperformance — to all kinds of digital images of biological objects’ borders was found in the compound function described by the formula. Its affinity to object’s borders on the MRI images was 0.87–0.99; for the borders of biological objects on the images obtained with optical methods it was lower than 0.99 only in two out of seven tests (0.95 and 0.97). Discussion. The high affinity of the proposed compound function may be associated with the fact that the three members of this synthetic expression correspond to three individual additive physical phenomena manifesting its biological basis. The first member is responsible for general biological contrast differentiation — the delineation of tissues appears sharpest at the borders of the organs. The second member describes the conventional membrane present in all healthy organized biological structures, including epithelial lining of the esophagus, muscle fascia, developed mucous membrane etc. The third member of the proposed function characterizes the blurred junction of arbitrarily-uniform structures. The proposed mathematical apparatus describes the formation of scalar field of probabilities for selected borders of biological structures and can easily be transformed into vector representation. Additional advantage of the developed and tested mathematical apparatus is the fact that the formulated approach can be used for determining the orientation of brightness increment gradient. This, in turn, allows distinguishing additional properties of biological objects based on calculation of the direction of development and growth of the tissue and structural anisotropy.

СТРУКТУРНО-ЛОГИСТИЧЕСКАЯ МОДЕЛЬ МАТЕРИАЛЬНЫХ ПОТОКОВ ЦИФРОВОЙ ЖИВОТНОВОДЧЕСКОЙ ФЕРМЫ

The problems of the digitalization of livestock enterprises are closely related to the construction of models and algorithms describing the functioning of individual technological processes and subsystems united by a common control system. Based on the cluster approach, three groups of tasks for the intellectualization and digitalization of objects in livestock breeding are formulated: 1) recognition of images of biological objects and models of their group and individual behavior, 2) genomic assessment of farm animals, prediction of their genetic potential, with the possibility of better adaptation to technologies and specifi c economic conditions, 3) multi-agent management of automated and robotic technical means. The authors initialized the video images of biological objects, developed a structural and functional model of a complex biotechnical system “Man-Machine-Animal”, including automated workstations of key specialists, signal receiving-and-transmitting base stations, technological modules for animal service (feeding, watering, milking, microclimate, etc.), representing local biotechnical systems. The paper presents a structural-and-logistic “funnel” model of a livestock farm functioning. The model includes vectors of incoming material fl ows, outgoing production fl ows and outgoing byproducts (production waste) described using appropriate formalizations. The authors provide the structural typifi cation of technological modules and subsystems for their mathematical analysis and subsequent digital transformation of livestock farms.

Developments in Contact Lens Imaging: New Applications of Optical Coherence Tomography

Optical coherence tomography (OCT) is a high-speed and non-contact optical imaging technology widely used for noninvasive cross-sectional imaging of biological objects. Two main OCT technologies have been developed: time domain and Fourier domain technologies. The latter can be further divided into spectral domain OCT, which uses a broadband light source and a spectrometer as a detector, and swept source OCT, which employs a quickly-rotating laser source. Advances in OCT technology have made it one of the most helpful devices in ophthalmic practice. Fourier OCT has revolutionized imaging of the posterior segment of the eye, as well as of anterior structures and has enhanced the ability to diagnose and manage patients. It provides high-resolution information about the tear film, contact lens (CL), a qualitative and quantitative assessment of the anterior eye that is important in contact lens fitting, and allows possible eye surface changes while wearing contact lenses to be monitored. Potential swept source OCT technology applications include industrial processes of lens design and quality control. In this paper, we describe clinical applications and outline a variety of multifunctional uses of OCT in the field of refractive error correction with contact lenses.

Deferred Registration of Nanophosphor Photoluminescence As a Platform for Optical Bioimaging

Detection systems with deferred registration of luminescence signals are promising for performing complex tasks of imaging of biological objects due to their simplicity and low cost. In the present work, β‑NaYF4:Tm3+Yb3+/NaYF4 nanocrystals with anti-Stokes photoluminescence have been used in deferred registration systems. It has been shown that there is a significant time delay between the exciting laser pulse and luminescence signal, which makes it possible to use this class of nanoparticles in the creation of wide-field imaging systems with deferred registration. The possibility of using nanoparticles for detecting a photoluminescence signal in the second transparency window of biotissue has been demonstrated. This system can be based on the resonance excitation and detection of the photoluminescence signal of Yb3+ ions.

Отложенная регистрация фотолюминесценции нанофосфоров как платформа для оптического биоимиджинга-=SUP=-*-=/SUP=-

AbstractDetection systems with deferred registration of luminescence signals are promising for performing complex tasks of imaging of biological objects due to their simplicity and low cost. In the present work, β‑NaYF_4:Tm^3+Yb^3+/NaYF_4 nanocrystals with anti-Stokes photoluminescence have been used in deferred registration systems. It has been shown that there is a significant time delay between the exciting laser pulse and luminescence signal, which makes it possible to use this class of nanoparticles in the creation of wide-field imaging systems with deferred registration. The possibility of using nanoparticles for detecting a photoluminescence signal in the second transparency window of biotissue has been demonstrated. This system can be based on the resonance excitation and detection of the photoluminescence signal of Yb^3 + ions.

Enhancement of terahertz photoconductive antenna operation by optical nanoantennas

AbstractPhotoconductive antennas are promising sources of terahertz radiation that is widely used for spectroscopy, characterization, and imaging of biological objects, deep space studies, scanning of surfaces, and detection of potentially hazardous substances. These antennas are compact and allow for generation of both ultrabroadband pulses and tunable continuous wave terahertz signals at room temperatures, with no need for high‐power optical sources. However, such antennas have relatively low energy conversion efficiency of femtosecond laser pulses or two close pump wavelengths (photomixers) into the pulsed and continuous terahertz radiation, correspondingly. Recently, an approach to solving this problem that involves known methods of nanophotonics applied to terahertz photoconductive antennas and photomixers has been proposed. This approach comprises the use of optical nanoantennas for enhancing the absorption of pump laser radiation in the antenna gap, reducing the lifetime of photoexcited carriers, and improving the antenna thermal efficiency. This Review is intended to systematize the main results obtained by researchers in this promising field of hybrid optical‐to‐terahertz photoconductive antennas and photomixers. We summarize the main results on hybrid THz antennas, compare the approaches to their implementation, and offer further perspectives of their development including an application of all‐dielectric nanoantennas instead of plasmonic ones. image

Numerical study of holographic electromagnetic induction technique for imaging arbitrarily shaped biological objects

This manuscript presents the working principle of holographic electromagnetic induction (HEMI) method for imaging small lesions in arbitrarily shaped biological objects. A computer model is developed to demonstrate a scattered magnetic field from optically small dielectric and arbitrarily shaped magnetic objects adsorbed onto a planar dielectric substrate. Wave propagation is included in the numerical model, particularly in modelling of biomedical applications. Results show that the HEMI image method has an ability to produce images of biological objects. Several potential medical imaging applications of the HEMI are available, including head imaging for brain stroke detection, breast imaging for breast cancer detection, diabetic ulcers and burns.

Single-distance phase retrieval algorithm for Bragg Magnifier microscope.

We present an improved, single-distance phase retrieval algorithm applicable for holographic X-ray imaging of biological objects for an in-line germanium Bragg Magnifier Microscope (BMM). The proposed algorithm takes advantage of a modified shrink-wrap algorithm for phase objects, robust unwrapping algorithm as well as other reasonable constraints applied to the wavefield at the object and the detector plane. The performance of the algorithm is analyzed on phantom objects and the results are shown and discussed. We demonstrated the suitability of the algorithm for the phase retrieval on a more complex biological specimen Tardigrade, where we achieved successful phase retrieval from only a single hologram. The spatial resolution obtained by Fourier spectral power method for biological objects is ∼ 300 nm, the same value as obtained from the reconstructed test pattern. Our results achieved using the new algorithm confirmed the potential of BMM for in-vivo, dose-efficient single-shot imaging of biological objects.

Use of micro computed-tomography and 3D printing for reverse engineering of mouse embryo nasal capsule

Imaging of increasingly complex cartilage in vertebrate embryos is one of the key tasks of developmental biology. This is especially important to study shape-organizing processes during initial skeletal formation and growth. Advanced imaging techniques that are reflecting biological needs give a powerful impulse to push the boundaries of biological visualization. Recently, techniques for contrasting tissues and organs have improved considerably, extending traditional 2D imaging approaches to 3D . X-ray micro computed tomography (μCT), which allows 3D imaging of biological objects including their internal structures with a resolution in the micrometer range, in combination with contrasting techniques seems to be the most suitable approach for non-destructive imaging of embryonic developing cartilage. Despite there are many software-based ways for visualization of 3D data sets, having a real solid model of the studied object might give novel opportunities to fully understand the shape-organizing processes in the developing body. In this feasibility study we demonstrated the full procedure of creating a real 3D object of mouse embryo nasal capsule, i.e. the staining, the μCT scanning combined by the advanced data processing and the 3D printing.

Detection of Circularly Polarized Luminescence of a Cs‐EuIII Complex in Raman Optical Activity Experiments

AbstractCircularly polarized luminescence (CPL) spectra are extremely sensitive to molecular structure. However, conventional CPL measurements are difficult and require expensive instrumentation. As an alternative, we explore CPL using Raman scattering and Raman optical activity (ROA) spectroscopy. The cesium tetrakis(3‐heptafluoro‐butylryl‐(+)‐camphorato) europium(III) complex was chosen as a model as it is known to exhibit very large CPL dissymmetry ratio. The fluorescent bands could be discriminated from true Raman signals by comparison of spectra acquired with different laser excitation wavelengths. Furthermore, the ROA technique enables fluorescence identification by measuring the degree of circularity. The CPL dissymmetry ratio was measured as the ROA circular intensity difference of 0.71, the largest one ever reported. The alternative CPL measurement enhances applications of lanthanides in analytical chemistry and chemical imaging of biological objects.

Detection of Circularly Polarized Luminescence of a Cs-Eu(III) Complex in Raman Optical Activity Experiments.

Circularly polarized luminescence (CPL) spectra are extremely sensitive to molecular structure. However, conventional CPL measurements are difficult and require expensive instrumentation. As an alternative, we explore CPL using Raman scattering and Raman optical activity (ROA) spectroscopy. The cesium tetrakis(3-heptafluoro-butylryl-(+)-camphorato) europium(III) complex was chosen as a model as it is known to exhibit very large CPL dissymmetry ratio. The fluorescent bands could be discriminated from true Raman signals by comparison of spectra acquired with different laser excitation wavelengths. Furthermore, the ROA technique enables fluorescence identification by measuring the degree of circularity. The CPL dissymmetry ratio was measured as the ROA circular intensity difference of 0.71, the largest one ever reported. The alternative CPL measurement enhances applications of lanthanides in analytical chemistry and chemical imaging of biological objects.

Cost-effective potential application of acousto-optic Bragg imaging of biological tissue

Acousto-Optic Bragg Imaging is a technique that uses the interaction of light with ultrasound to optically image obstructions in acoustical fields. Existing reports of Acousto-Optic Bragg Imaging based on transmission of acoustic fields through obstructions exhibit strong acoustic impedance mismatches manifested by poor image quality and missing details of physical structures of obstructions. In this work, the image quality was improved to exhibit detailed physical structures of an object by using an improved Bragg imaging system. This project investigates the possibility of extending an acoustic Bragg imaging technique in transmission mode to image animal or plant tissues; a small Azalea leaf is used as an illustration in this case. The Bragg image produced clearly shows the veins of the vascular azalea leaf serving as a proof of concept for cost-effective potential application of acoustic Bragg imaging of biological objects in the medical field. Moreover, acousto-optic Bragg imaging is potentially harmless to biological cells and is sensitive to density and elastic variations in the tissue.

TH-AB-204-06: Using Associated Particle Imaging and Time-Of-Flight Spectroscopy for Eliminating Tomographic Imaging for NSECT: A Simulation Study

Purpose: To evaluate feasibility of associated particle time-of-flight (AP-TOF) neutron imaging with a fan beam source using simulations in GEANT4 and determine its effect on improving scan time in Neutron Stimulated Emission Computed Tomography (NSECT). Previous NSECT experiments have used a pencil-beam, raster-scanned through the entire volume of interest with long scan durations. A fan beam could reduce the scan duration substantially, improving the clinical feasibility of the technique. Methods: A simulation of fast-neutron AP-TOF NSECT was developed in GEANT4. Fast neutrons that undergo inelastic scattering with elemental nuclei in the phantom lead to prompt gamma emission with energy specific to the emitting element used to identify the emitting elements. In the simulation, a 2-degree wide fan beam of 5 MeV neutrons was swept across a prone water breast phantom containing a cancerous lesion. For each neutron emitted, an alpha particle was coincidently emitted in the opposite direction and was used to determine the neutron's flight path. The neutron's time of flight was used to determine the depth of interaction along the flight path. Images were reconstructed for each element in the breast phantom to assess location accuracy with AP-TOF imaging. Results: Images reconstructed from H and Fe showed strong agreement with the locations and geometry of the breast (H-2224 keV) and lesion (Fe-847 keV), with <3% error between the measured and actual locations. Uncertainties in the lateral and axial (i.e., along the beam) directions were determined to arise from uncertainty in the source aperture opening when determining alpha particle location (lateral: 1–2cm) and gamma detection time (axial: 1–2ns). Conclusion: AP-TOF neutron imaging with a pseudo-fan beam is capable of generating clinically relevant images of biological objects without the need for tomographic rotation. With appropriate detection hardware, the ability to eliminate tomographic rotation could reduce NSECT acquisition time by a factor of 8–10.