scholarly journals In-Depth Analysis of Egg-Tempera Paint Layers by Multiphoton Excitation Fluorescence Microscopy

2020 ◽  
Vol 12 (9) ◽  
pp. 3831
Author(s):  
Alice Dal Fovo ◽  
Mikel Sanz ◽  
Mohamed Oujja ◽  
Raffaella Fontana ◽  
Sara Mattana ◽  
...  
Keyword(s):  
Fiber Optics ◽  
Nonlinear Optical ◽  
Near Infrared ◽  
Three Dimensional ◽  
Optical Systems ◽  
Scattering Media ◽  
Invasive Approach ◽  
Non Invasive ◽  
Egg Tempera ◽  
Depth Analysis

The non-invasive depth-resolved imaging of pictorial layers in paintings by means of linear optical techniques represents a challenge in the field of Cultural Heritage (CH). The presence of opaque and/or highly-scattering materials may obstruct the penetration of the radiation probe, thus impeding the visualization of the stratigraphy of paintings. Nonlinear Optical Microscopy (NLOM), which makes use of tightly-focused femtosecond pulsed lasers as illumination sources, is an emerging technique for the analysis of painted objects enabling micrometric three-dimensional (3D) resolution with good penetration capability in semi-transparent materials. In this work, we evaluated the potential of NLOM, specifically in the modality of Multi-Photon Excitation Fluorescence (MPEF), to probe the stratigraphy of egg-tempera mock-up paintings. A multi-analytical non-invasive approach, involving ultraviolet-visible-near infrared (UV-Vis-NIR) Fiber Optics Reflectance Spectroscopy, Vis-NIR photoluminescence, and Laser Induced Fluorescence, yielded key-information for the characterization of the constituting materials and for the interpretation of the nonlinear results. Furthermore, the use of three nonlinear optical systems allowed evaluation of the response of the analyzed paints to different excitation wavelengths and photon doses, which proved useful for the definition of the most suitable measurement conditions. The micrometric thickness of the paint layers, which was not measurable by means of Optical Coherence Tomography (OCT), was instead assessed by MPEF, thus demonstrating the effectiveness of this nonlinear modality in probing highly-scattering media, while ensuring the minimal photochemical disturbance to the examined materials.

scholarly journals Focality of the Induced E-Field Is a Contributing Factor in the Choice of TMS Parameters: Evidence from a 3D Computational Model of the Human Brain

2020 ◽  
Vol 10 (12) ◽  
pp. 1010
Author(s):  
Deepika Konakanchi ◽  
Amy L. de Jongh Curry ◽  
Robert S. Waters ◽  
Shalini Narayana
Keyword(s):  
Spatial Distribution ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Element Model ◽  
Brain Areas ◽  
Invasive Approach ◽  
Non Invasive ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
The Impact

Transcranial magnetic stimulation (TMS) is a promising, non-invasive approach in the diagnosis and treatment of several neurological conditions. However, the specific results in the cortex of the magnitude and spatial distribution of the secondary electrical field (E-field) resulting from TMS at different stimulation sites/orientations and varied TMS parameters are not clearly understood. The objective of this study is to identify the impact of TMS stimulation site and coil orientation on the induced E-field, including spatial distribution and the volume of activation in the cortex across brain areas, and hence demonstrate the need for customized optimization, using a three-dimensional finite element model (FEM). A considerable difference was noted in E-field values and distribution at different brain areas. We observed that the volume of activated cortex varied from 3000 to 7000 mm3 between the selected nine clinically relevant coil locations. Coil orientation also changed the induced E-field by a maximum of 10%, and we noted the least optimal values at the standard coil orientation pointing to the nose. The volume of gray matter activated varied by 10% on average between stimulation sites in homologous brain areas in the two hemispheres of the brain. This FEM simulation model clearly demonstrates the importance of TMS parameters for optimal results in clinically relevant brain areas. The results show that TMS parameters cannot be interchangeably used between individuals, hemispheres, and brain areas. The focality of the TMS induced E-field along with its optimal magnitude should be considered as critical TMS parameters that should be individually optimized.

scholarly journals Impedance-Based Monitoring of Mesenchymal Stromal Cell Three-Dimensional Proliferation Using Aerosol Jet Printed Sensors: A Tissue Engineering Application

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2231 ◽  
Author(s):  
Sarah Tonello ◽  
Andrea Bianchetti ◽  
Simona Braga ◽  
Camillo Almici ◽  
Mirella Marini ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Phase Angle ◽  
Electrical Impedance ◽  
Three Dimensional ◽  
Model Parameters ◽  
Tissue Engineering Application ◽  
Hybrid Hydrogel ◽  
Invasive Approach ◽  
Non Invasive ◽  
Aerosol Jet Printing

One of the main hurdles to improving scaffolds for regenerative medicine is the development of non-invasive methods to monitor cell proliferation within three-dimensional environments. Recently, an electrical impedance-based approach has been identified as promising for three-dimensional proliferation assays. A low-cost impedance-based solution, easily integrable with multi-well plates, is here presented. Sensors were developed using biocompatible carbon-based ink on foldable polyimide substrates by means of a novel aerosol jet printing technique. The setup was tested to monitor the proliferation of human mesenchymal stromal cells into previously validated gelatin-chitosan hybrid hydrogel scaffolds. Reliability of the methodology was assessed comparing variations of the electrical impedance parameters with the outcomes of enzymatic proliferation assay. Results obtained showed a magnitude increase and a phase angle decrease at 4 kHz (maximum of 2.5 kΩ and −9 degrees) and an exponential increase of the modeled resistance and capacitance components due to the cell proliferation (maximum of 1.5 kΩ and 200 nF). A statistically significant relationship with enzymatic assay outcomes could be detected for both phase angle and electric model parameters. Overall, these findings support the potentiality of this non-invasive approach for continuous monitoring of scaffold-based cultures, being also promising in the perspective of optimizing the scaffold-culture system.

scholarly journals Assessing Laser Cleaning of a Limestone Monument by Fiber Optics Reflectance Spectroscopy (FORS) and Visible and Near-Infrared (VNIR) Hyperspectral Imaging (HSI)

Minerals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1052
Author(s):  
Costanza Cucci ◽  
Olga De Pascale ◽  
Giorgio S. Senesi
Keyword(s):  
Fiber Optics ◽  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Conservation Status ◽  
Spectral Characteristics ◽  
Imaging Spectroscopy ◽  
Reflectance Spectroscopy ◽  
Laser Cleaning ◽  
Cleaning Process ◽  
Invasive Approach

Fiber optics reflectance spectroscopy (FORS) and visible and near-infrared (VNIR) hyperspectral imaging (HSI) were applied to assess and control the laser cleaning process of a deeply darkened limestone surface collected from the historic entrance gate of Castello Svevo, Bari, Italy. Both techniques enabled us to verify the different degree of removal of a thick deposit of black crust from the surface of the walls. Results obtained were in good agreement with those of previous studies of the elemental composition achieved by application of laser-induced breakdown spectroscopy (LIBS). Coupling FORS and VNIR-HSI provided important information on the optimal conditions to evaluate the conservation status and determine the more appropriate level of cleaning restoration, thus avoiding over- and/or under-cleaning. Imaging spectroscopy was used to obtain maps of areas featuring the same or different spectral characteristics, so to achieve a sufficient removal of unwanted layers, without modifying the surface underneath, and to increase the efficiency of traditional cleaning techniques. The performance of the combined non-invasive approach used in this work shows promise for further applications to other types of rocks and highlights the potential for in situ assessment of the laser cleaning process based on reflectance spectroscopy.

scholarly journals A Multi-Analytical Non-Invasive Approach to Aqueous Cleaning Systems in Treatments on Bowed String Musical Instruments

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 150
Author(s):  
Ilaria Cazzaniga ◽  
Marco Gargano ◽  
Claudia Invernizzi ◽  
Nicola G. Ludwig ◽  
Marco Malagodi ◽  
...  
Keyword(s):  
Analytical Approach ◽  
Near Infrared ◽  
Multispectral Imaging ◽  
Musical Instruments ◽  
Invasive Approach ◽  
Non Invasive ◽  
Cleaning System ◽  
Cleaning Methods ◽  
Physical Changes ◽  
Different Levels

Restoration and conservation procedures for historical musical instruments involve several issues, also connected with their frequent being played. One of the most delicate procedures for their preservation is the cleaning of surfaces from soil and dirt which have accumulated over the years. In fact, when external particles reach the surface, a fraction of them can deposit on it. Moreover, the contact with the player can generate chemical-physical changes, rapidly warming and wetting the surfaces through sweat deposition. This work focused on the cleaning methods of surfaces of bowed string musical instruments by a systematic and analytical approach. The selective cleaning procedure of varnished surfaces from grime and soil needs to be performed without compromising the original matter. Therefore, a dirty surface was reproduced on a set of varnished mock-ups and different water-based cleaning systems—generally used by restorers—were tested. The procedures were monitored in each step with several analytical methods: multispectral imaging (near-infrared (NIR), IRFC, visible imaging (VIS), UV-induced visible fluorescence), stereomicroscopy, XRF and FTIR spectroscopies allowed us to non-invasively outline the cleaning system efficacy. The results highlighted different levels of cleaning and, in some cases, it was possible to identify the best selectivity for the different procedures.

scholarly journals Transmissive Single-Pixel Microscopic Imaging through Scattering Media

Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2721
Author(s):  
Huaxia Deng ◽  
Guan Wang ◽  
Qiang Li ◽  
Qianzhen Sun ◽  
Mengchao Ma ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Medical Imaging ◽  
Medical Diagnosis ◽  
Alternative Solution ◽  
Optical Systems ◽  
Scattering Media ◽  
Microscopic Imaging ◽  
Non Invasive ◽  
Strong Scattering ◽  
Single Pixel

Microscopic imaging is of great significance for medical diagnosis. However, due to the strong scattering and absorption of tissue, the implementation of non-invasive microscopic imaging is very difficult. Traditional single-pixel microscopes, based on reflective optical systems, provide an alternative solution for scattering media imaging. Here, the single-pixel microscope with transmissive liquid crystal modulation is proposed. The microscopic ability of the proposed microscope is calibrated. The multi-spectral microscopic imaging of the object is demonstrated. The transmissive imaging of the object behind the scattering media is analyzed. The proposed prototype of the transmissive single-pixel microscope is expected to be applied in microscopic imaging through scattering media and medical imaging.

EXAMPLES OF FORCED SYMMETRY-BREAKING TO HETEROCLINIC CYCLES AND NETWORKS IN THREE-DIMENSIONAL EUCLIDEAN-INVARIANT SYSTEMS

2009 ◽  
Vol 19 (05) ◽  
pp. 1655-1678
Author(s):  
M. J. PARKER ◽  
M. G. M. GOMES ◽  
I. N. STEWART
Keyword(s):  
Symmetry Breaking ◽  
Nonlinear Optical ◽  
Three Dimensional ◽  
Reaction Diffusion ◽  
Three Dimensions ◽  
Optical Systems ◽  
Heteroclinic Cycles ◽  
Reaction Diffusion Systems ◽  
Diffusion Systems ◽  
Face Centered

In [Parker et al., 2008a] group theory was employed to prove the existence of homoclinic cycles in forced symmetry-breaking of simple (SC), face-centered (FCC), and body-centered (BCC) cubic planforms. In this paper we extend this classification demonstrating that more elaborate heteroclinic cycles and networks can arise through the same process. Our methods naturally generate graphs that represent possible heteroclinic cycles and networks. The results do not depend on the representation of the symmetry group and are thus quite general. This study is motivated by pattern formation in three dimensions which occur in reaction–diffusion systems, certain nonlinear optical systems and the polyacrylamide methylene blue oxygen reaction. This work extends previous work by Parker et al. [2006, 2008a, 2008b] and Hou and Golubitsky [1997].

scholarly journals Virtual hysteroscopy: a new non invasive approach for the assessment of uterine cavity

2017 ◽  
Vol 19 (2) ◽  
pp. 216 ◽  
Author(s):  
Paulo Sergio Cossi ◽  
Heron Werner ◽  
Alberto Borges Peixoto ◽  
Wellington P Martins ◽  
Edward Araujo Júnior
Keyword(s):  
Three Dimensional ◽  
Uterine Cavity ◽  
Premenopausal Women ◽  
Invasive Approach ◽  
Non Invasive ◽  
Uterine Anomalies ◽  
Detailed Assessment ◽  
Diagnostic Hysteroscopy ◽  
Scan Data ◽  
Endometrial Pathology

Endometrial pathology is frequent in premenopausal women and the diagnostic hysteroscopy is considered the gold standard for assessing endometrial cavity and congenital uterine anomalies. However it is an invasive and uncomfortable procedure. Saline contrast hysterosalgingography and hysterosalpingo-contrast sonography allow detailed assessment of the uterine cavity. We propose a virtual hysteroscopy from three-dimensional saline and three-dimensional hysterosalpingo-contrast sonography scan data to generate a virtual reality as a new noninvasive procedure for assessing the uterine cavity in uterine congenital anomaly and endometrial pathology cases as well.

scholarly journals Discovering hidden architectures of ancient time: 3d data survey to reveal the myth of mithra in Santa Maria Capua Vetere

2014 ◽  
Vol XL-5 ◽  
pp. 121-128
Author(s):  
M. Campi ◽  
R. Catuogno ◽  
A. di Luggo ◽  
D. Iovane ◽  
D. Palomba
Keyword(s):  
Three Dimensional ◽  
Advanced Technology ◽  
Invasive Approach ◽  
Non Invasive ◽  
3D Data ◽  
Data Survey ◽  
Integrated Methods ◽  
New Generation ◽  
Representation Techniques ◽  
Santa Maria

The research illustrated in this paper is part of a wider testing ground, aimed at identifying and developing processes of le arning and development taking place in archaeological contexts. These sites are investigated through the use of advanced technology, based on integrated methods of survey of new generation. The aim is to identify alternative languages of representation, able to read and to represent effectively the analyzed object and to propose alternative enjoyment systems. The case study is the Mithraeum in Santa Maria Capua Vetere, for which were carried out surveys with non-contact techniques, based on the use of instrumentations, for the acquisition of colorimetric and metric informations, that exploit a non-invasive approach. Data coming from laser scanner's sensors, combined with GPS receivers, are processed to define a three-dimensional centimetric space, in a single reference system of individual scans. Purpose of this research is to identify representation techniques able to communicate the sense of the multiple interrelations and of interferences among parties, providing the subsequent insertion of data into a wider project of cataloging, fruition and valuation of cultural heritage. The chance to diffuse Digital surveys is now a possible and implementable reality. The purpose is to spread awareness of World Heritage, in a participatory manner and based on the spiri t of knowledge, conveying all the strength of cultural content that heritage has.

scholarly journals Wavefront Shaping Concepts for Application in Optical Coherence Tomography—A Review

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7044
Author(s):  
Jonas Kanngiesser ◽  
Bernhard Roth
Keyword(s):  
Optical Coherence Tomography ◽  
Scattered Light ◽  
Three Dimensional ◽  
Medical Diagnostics ◽  
Optical Coherence ◽  
Scattering Media ◽  
Destructive Testing ◽  
Non Invasive ◽  
Wavefront Shaping ◽  
Micrometer Scale

Optical coherence tomography (OCT) enables three-dimensional imaging with resolution on the micrometer scale. The technique relies on the time-of-flight gated detection of light scattered from a sample and has received enormous interest in applications as versatile as non-destructive testing, metrology and non-invasive medical diagnostics. However, in strongly scattering media such as biological tissue, the penetration depth and imaging resolution are limited. Combining OCT imaging with wavefront shaping approaches significantly leverages the capabilities of the technique by controlling the scattered light field through manipulation of the field incident on the sample. This article reviews the main concepts developed so far in the field and discusses the latest results achieved with a focus on signal enhancement and imaging.

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