New frontiers in multispectral chemical imaging

1994 ◽  
Vol 52 ◽  
pp. 156-157
Author(s):  
Michael D. Schaeberle ◽  
Patrick J. Treado
Keyword(s):  
Indium Antimonide ◽  
Near Infrared ◽  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Biological Tissues ◽  
Quantitative Information ◽  
Chemical Imaging ◽  
Platinum Silicide ◽  
Non Invasive ◽  
Ccd Detectors

Recent advancements in visible and near-infrared multichannel detectors as well as the availability of novel imaging quality tunable filters make multispectral chemical imaging microscopy viable for routine materials characterization. Our research involves the development and application of chemical imaging methods that are rapid, non-invasive, and intuitive. The methods require limited sample preparation, and can be performed at high spectral and spatial resolution.The chemical imaging techniques employ Raman scattering, fluorescence emission or infrared absorption spectroscopies in combination with optical microscopy. In general, the methods provide qualitative and quantitative information about the composition and distribution of constituents within a wide host of materials, including biological tissues, polymers, and semiconductors.Silicon charge-coupled device (CCD) detectors are widely utilized for image detection in visible microscopy. Currently underutilized, but providing significant capabilities for chemical imaging based on infrared vibrational absorption are focal plane array (FPA) detectors providing sensitivity in the near-infrared and mid infrared. These include cameras constructed from indium antimonide (InSb), platinum silicide (PtSi), indium gallium arsenide (InGaAs) and mercury cadmium telluride (MCT).

scholarly journals Targeting Contrast Agents With Peak Near-Infrared-II (NIR-II) Fluorescence Emission for Non-invasive Real-Time Direct Visualization of Thrombosis

2021 ◽  
Vol 8 ◽  
Author(s):  
Kenneth S. Hettie
Keyword(s):  
Contrast Agents ◽  
Real Time ◽  
Near Infrared ◽  
Fluorescence Emission ◽  
Therapeutic Window ◽  
Direct Visualization ◽  
Spatiotemporal Resolution ◽  
Accurate Identification ◽  
Non Invasive ◽  
Nirf Imaging

Thrombosis within the vasculature arises when pathological factors compromise normal hemostasis. On doing so, arterial thrombosis (AT) and venous thrombosis (VT) can lead to life-threatening cardio-cerebrovascular complications. Unfortunately, the therapeutic window following the onset of AT and VT is insufficient for effective treatment. As such, acute AT is the leading cause of heart attacks and constitutes ∼80% of stroke incidences, while acute VT can lead to fatal therapy complications. Early lesion detection, their accurate identification, and the subsequent appropriate treatment of thrombi can reduce the risk of thrombosis as well as its sequelae. As the success rate of therapy of fresh thrombi is higher than that of old thrombi, detection of the former and accurate identification of lesions as thrombi are of paramount importance. Magnetic resonance imaging, x-ray computed tomography (CT), and ultrasound (US) are the conventional non-invasive imaging modalities used for the detection and identification of AT and VT, but these modalities have the drawback of providing only image-delayed indirect visualization of only late stages of thrombi development. To overcome such limitations, near-infrared (NIR, ca. 700–1,700 nm) fluorescence (NIRF) imaging has been implemented due to its capability of providing non-invasive real-time direct visualization of biological structures and processes. Contrast agents designed for providing real-time direct or indirect visualization of thrombi using NIRF imaging primarily provide peak NIR-I fluorescence emission (ca. 700–1,000 nm), which affords limited tissue penetration depth and suboptimal spatiotemporal resolution. To facilitate the enhancement of the visualization of thrombosis via providing detection of smaller, fresh, and/or deep-seated thrombi in real time, the development of contrast agents with peak NIR-II fluorescence emission (ca. 1000–1,700 nm) has been recently underway. Currently, however, most contrast agents that provide peak NIR-II fluorescence emissions that are purportedly capable of providing direct visualization of thrombi or their resultant occlusions actually afford only the indirect visualization of such because they only provide for the (i) measuring of the surrounding vascular blood flow and/or (ii) simple tracing of the vasculature. These contrast agents do not target thrombi or occlusions. As such, this mini review summarizes the extremely limited number of targeting contrast agents with peak NIR-II fluorescence emission developed for non-invasive real-time direct visualization of thrombosis that have been recently reported.

scholarly journals Imaging of Chlorophyll a Fluorescence in Natural Compound-Induced Stress Detection

2020 ◽  
Vol 11 ◽  
Author(s):  
Adela M. Sánchez-Moreiras ◽  
Elisa Graña ◽  
Manuel J. Reigosa ◽  
Fabrizio Araniti
Keyword(s):  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Invasive Technique ◽  
Plant Defense Response ◽  
Stress Detection ◽  
Secondary Effects ◽  
Non Invasive ◽  
Induced Stress ◽  
Fluorescence Images ◽  
Spatio Temporal

Imaging of chlorophyll a fluorescence (CFI) represents an easy, precise, fast and non-invasive technique that can be successfully used for discriminating plant response to phytotoxic stress with reproducible results and without damaging the plants. The spatio-temporal analyses of the fluorescence images can give information about damage evolution, secondary effects and plant defense response. In the last years, some studies about plant natural compounds-induced phytotoxicity have introduced imaging techniques to measure fluorescence, although the analysis of the image as a whole is often missed. In this paper we, therefore, evaluated the advantages of monitoring fluorescence images, presenting the physiological interpretation of different possible combinations of the most relevant parameters linked to fluorescence emission and the images obtained.

scholarly journals SPETTROSCOPIA E IMAGING IN OTTICA DIFFUSA: FOCUS SUL TUMORE DELLA MAMMELLA

2020 ◽  
Author(s):  
Paola Taroni
Keyword(s):  
Breast Cancer ◽  
Near Infrared ◽  
Breast Cancer Diagnosis ◽  
Biological Tissues ◽  
Blood Parameters ◽  
Collagen Content ◽  
Diffuse Optics ◽  
Non Invasive ◽  
Ultrasound Diagnostics

Through the measurement of the optical properties (absorption and scattering), diffuse optical spectroscopy allows one to estimate non-invasively the composition of biological tissues (water, lipid and collagen content) and functional blood parameters. Further, it provides information on the microscopic tissue structure. It can therefore be effectively used in vivo as an absolutely non-invasive diagnostic tool. The Department of Physics of the Politecnico di Milano has designed and built an optical mammograph that exploits diffused optics, operating with pulsed light at 7 wavelengths in the red and near infrared spectral range (635-1060 nm). The instrument was used in a clinical study on 200 subjects, in collaboration with the European Institute of Oncology: optically derived tissue composition and in particular collagen content in tissues proved to be effective both to discriminate between malignant and benign breast lesions, and to estimate the risk of breast cancer related to the density of breast tissue, which is recognized among the most important independent risk factors. Partly based on those results, “SOLUS - Smart optical and ultrasound diagnostics of breast cancer”, a European project in the H2020 Framework Program, is now working to improve the specificity of non-invasive breast cancer diagnosis by combining diffuse optics with ultrasound imaging.

scholarly journals Chemical Characterization of Pope Pius VII Ancient Ecclesiastical Vestment by a Multi-Analytical Approach

Heritage ◽  
2021 ◽  
Vol 4 (3) ◽  
pp. 1616-1638
Author(s):  
Donata Magrini ◽  
Susanna Bracci ◽  
Roberta Iannaccone ◽  
Lucia Nucci ◽  
Barbara Salvadori
Keyword(s):  
Near Infrared ◽  
Imaging Techniques ◽  
Chemical Characterization ◽  
Analytical Investigation ◽  
Gas Chromatography Mass Spectrometry ◽  
Non Invasive ◽  
Analytical Protocol ◽  
Materials Used ◽  
Invasive Techniques ◽  
The 19Th Century

This paper presents a multi-analytical investigation performed for the study of the ecclesiastical vestment, with insignia, of Pope Pius VII, painted from the end of the 18th up to the beginning of the 19th century, made of five clothing elements: chasuble, stole, maniple, chalice veil and purse. The aim of this research was to assess the conservation state of the silk and painted backgrounds; to define the manufacturing technique of the work; to localize, if present, the underdrawing and any retouching; to identify the pigments and, where possible, the binders used. A diagnostic protocol was developed based on preliminary investigations through multiband imaging techniques known as MBI (visible, ultraviolet-induced visible luminescence (UVL), near-infrared reflected (NIR) and infrared reflected false color (IRRFC) photography). The images acquired with MBI techniques ensured a more specific choice of spots to be analyzed directly in situ by non-invasive techniques. In particular, portable digital optical microscopy and X-ray fluorescence (XRF) were performed. Two fragments detached from the chasuble were also analyzed by microFT-IR, microRaman, scanning electron microscopy (SEM-EDS) and gas chromatography/mass spectrometry (GC-MS). Application of the multi-analytical protocol enabled the materials used to be characterized and helped to define the peculiar execution technique used. The presence of an underdrawing made with a carbon pencil was highlighted by MBI. Red lakes, iron-based pigments and copper-based pigments have been identified on the painting palette, applied with arabic gum as a binder.

scholarly journals A Multiwavelength Approach for the Study of Contemporary Painting Materials by Means of Fluorescence Imaging Techniques: An Integration to Spectroscopic Methods

2021 ◽  
Vol 12 (1) ◽  
pp. 94
Author(s):  
Margherita Longoni ◽  
Alessia Buttarelli ◽  
Marco Gargano ◽  
Silvia Bruni
Keyword(s):  
Uv Radiation ◽  
Near Infrared ◽  
Imaging Techniques ◽  
Fluorescence Emission ◽  
Excitation Wavelength ◽  
Visible Radiation ◽  
Infrared Luminescence ◽  
Wide Range ◽  
Synthetic Pigments ◽  
Contemporary Painting

Imaging methods based on visible luminescence induced by ultraviolet (UV) radiation are well consolidated in the investigation of ancient works of art, to map varnishes, retouches, and possibly some pigments. As far as contemporary art is involved, the wide range of synthetic materials, especially pigments, introduced from 1850 onwards, makes the possible application of the technique particularly challenging. Among the colouring substances used by artists in the 19th and 20th centuries, only cadmium-based pigments received attention due to their typical near-infrared luminescence. Nevertheless, the fluorescence emission exhibited by several synthetic pigments upon visible excitation was recently demonstrated and confirmed using UV radiation in the present work. The subsequent possibility of individuating such materials in paintings by ultraviolet fluorescence (UVF) images was explored on mock-up painting samples of a wide series of pigments dispersed in oil or acrylic binder. Visible and infrared luminescence images obtained by irradiating with visible radiation (VIVF and VIL) were also collected. It was thus evidenced the possible advantage of the choice of a different excitation wavelength in discriminating between the contributions of pigment and binder. Finally, a recent oil painting on panel was also examined as case study.

scholarly journals Process analytical technology tools for process control of roller compaction in solid pharmaceuticals manufacturing

2020 ◽  
Vol 70 (4) ◽  
pp. 443-463 ◽  
Author(s):  
Aleša Dular Vovko ◽  
Franc Vrečer
Keyword(s):  
Infrared Spectroscopy ◽  
Process Control ◽  
Near Infrared Spectroscopy ◽  
Near Infrared ◽  
Process Analytical Technology ◽  
Imaging Techniques ◽  
Thermal Effusivity ◽  
Chemical Imaging ◽  
Roller Compaction ◽  
Analytical Technology

AbstractThis article presents an overview of using process analytical technology in monitoring the roller compaction process. In the past two decades, near-infrared spectroscopy, near-infrared spectroscopy coupled with chemical imaging, microwave resonance technology, thermal effusivity and various particle imaging techniques have been used for developing at-, off-, on- and in-line models for predicting critical quality attributes of ribbons and subsequent granules and tablets. The common goal of all these methods is improved process understanding and process control, and thus improved production of high-quality products. This article reviews the work of several researchers in this field, comparing and critically evaluating their achievements.

scholarly journals Synthesis and Characterization of GdVO4:Nd Near-Infrared Phosphors for Optical Time-Gated In Vivo Imaging

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3564
Author(s):  
Ben Nimmegeers ◽  
Ewoud Cosaert ◽  
Tecla Carbonati ◽  
Daniela Meroni ◽  
Dirk Poelman
Keyword(s):  
Decay Time ◽  
Near Infrared ◽  
Imaging Techniques ◽  
Medical Personnel ◽  
Biological Tissues ◽  
The Body ◽  
Transparency Window ◽  
Optical Time ◽  
Gated Imaging

Many medical imaging techniques use some form of ionizing radiation. This radiation is not only potentially harmful for the patient, but also for the medical personnel. An alternative imaging technique uses near-infrared (NIR) emitting luminescent particles as tracers. If the luminescent probes are excited inside the body, autofluorescence from the biological tissues is also induced. This problem can be circumvented by using time-gated imaging. Hereby, the light collection only starts when the fluorescence of the tissue has decayed. This requires particles showing both excitation and emission in the near-infrared and a long decay time so that they can be used in time-gated imaging. In this work, Nd-doped GdVO4 NIR emitting particles were prepared using solid state reaction. Particles could be efficiently excited at 808 nm, right in the first transparency window for biological tissues, emitted in the second transparency window at around 1064 nm, and showed a decay time of the order of 70 μs, sufficiently long for time-gating. By using a Gd-containing host, these particles could be ideally suited for multimodal optical/magnetic imaging after size reduction and surface functionalization.

scholarly journals Fluorescence Imaging as a Tool in Preclinical Evaluation of Polymer-Based Nano-DDS Systems Intended for Cancer Treatment

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 471 ◽  
Author(s):  
Tomáš Etrych ◽  
Olga Janoušková ◽  
Petr Chytil
Keyword(s):  
Drug Delivery ◽  
Fluorescence Imaging ◽  
Targeted Drug Delivery ◽  
Near Infrared ◽  
Fluorescent Dyes ◽  
Imaging Modality ◽  
Imaging Techniques ◽  
Fluorescent Imaging ◽  
Non Invasive ◽  
Targeted Drug

Targeted drug delivery using nano-sized carrier systems with targeting functions to malignant and inflammatory tissue and tailored controlled drug release inside targeted tissues or cells has been and is still intensively studied. A detailed understanding of the correlation between the pharmacokinetic properties and structure of the nano-sized carrier is crucial for the successful transition of targeted drug delivery nanomedicines into clinical practice. In preclinical research in particular, fluorescence imaging has become one of the most commonly used powerful imaging tools. Increasing numbers of suitable fluorescent dyes that are excitable in the visible to near-infrared (NIR) wavelengths of the spectrum and the non-invasive nature of the method have significantly expanded the applicability of fluorescence imaging. This chapter summarizes non-invasive fluorescence-based imaging methods and discusses their potential advantages and limitations in the field of drug delivery, especially in anticancer therapy. This chapter focuses on fluorescent imaging from the cellular level up to the highly sophisticated three-dimensional imaging modality at a systemic level. Moreover, we describe the possibility for simultaneous treatment and imaging using fluorescence theranostics and the combination of different imaging techniques, e.g., fluorescence imaging with computed tomography.

scholarly journals Quantitative in vivo bioluminescence imaging of orthotopic patient-derived glioblastoma xenografts

2020 ◽  
Author(s):  
Anna L. Koessinger ◽  
Dominik Koessinger ◽  
Katrina Stevenson ◽  
Catherine Cloix ◽  
Louise Mitchell ◽  
...  
Keyword(s):  
Cell Lines ◽  
Tumour Growth ◽  
Near Infrared ◽  
Fluorescent Protein ◽  
Imaging Techniques ◽  
Glioblastoma Cells ◽  
Non Invasive ◽  
In Vivo Bioluminescence Imaging ◽  
Infrared Fluorescent Protein

AbstractDespite extensive research, little progress has been made in glioblastoma therapy, owing in part to a lack of adequate preclinical in vivo models to study this disease. To mitigate this, primary patient-derived cell lines, which maintain their specific stem-like phenotypes, have replaced established glioblastoma cell lines. However, due to heterogenous tumour growth inherent in glioblastoma, the use of primary cells for orthotopic in vivo studies often requires large experimental group sizes. Therefore, when using intracranial patient-derived xenograft (PDX) approaches, it is advantageous to deploy imaging techniques to monitor tumour growth and allow stratification of mice. Here we show that stable expression of near-infrared fluorescent protein (iRFP) in patient-derived glioblastoma cells enables rapid direct non-invasive monitoring of tumour development without compromising tumour stemness or tumorigenicity. Moreover, as this approach does not depend on the use of agents like luciferin, which can cause variability due to changing bioavailability, it can be used for quantitative longitudinal monitoring of tumour growth. Notably, we show that this technique also allows quantitative assessment of tumour burden in highly invasive models spreading throughout the brain. Thus, iRFP transduction of primary patient-derived glioblastoma cells is a reliable, cost- and time-effective way to monitor heterogenous orthotopic PDX growth.

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