The global fight against mosquito-borne viral diseases has in recent years been bolstered by the introduction of the endosymbiotic bacteria Wolbachia to vector populations, which in host mosquitoes supresses the transmissibility of several viruses. Researchers engaged on this front of the battle often need to know the Wolbachia infection status of individual mosquitoes as the intervention progresses

Multidrug resistance (MDR) is highly associated with poor prognosis of chronic myeloid leukemia (CML). This work aims to explore whether the laser tweezers Raman spectroscopy (LTRS) could be practical in separating adriamycin (ADR) resistance CML cells K562/ADR from its parental cells K562, and to explore the potential mechanisms. Detection of LTRS initially reflected the spectral differences caused

Label-free molecular imaging is a promising utility to study tissues in terms of the identification of their compartments as well as chemical features and alterations induced by disease. The aim of this work was to assess if higher magnification of optics in the FTIR microscope coupled with the focal plane detector (FPA) resulted in better resolution of lung structures and if the histopathological

The ultraviolet resonance Raman (UVRR) spectra of the adenine-containing enzymatic redox cofactors nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) in aqueous solution of physiological concentration are compared with the aim of distinguishing between them and their building block adenine in potential co-occurrence in biological materials. At an excitation wavelength of

Coherent anti-Stokes Raman scattering (CARS) spectroscopy is a powerful tool for Raman imaging technology. In contrast, conventional spontaneous Raman spectroscopy is often used for biological analysis with multivariate analysis. This study develops a new type of CARS instrument with a double-wavelength-emission background-free electronically tuned Ti:sapphire laser (DW-ETL). DW-ETL generates two laser

This focal point article discusses the developments of biomedical Raman and infrared spectroscopy, and the recent strive towards being a recognised clinical tool for various applications. The promise of vibrational spectroscopy in the field of biomedical science, alongside the development of computational methods for spectral analysis, has driven a plethora of proof-of-concept studies which convey

Melamine is a kind of small molecule compound, which has been illegally adulterated in dairy food because of the rich nitrogen content and stable chemical properties. Therefore, the detection of melamine is of great significance to food safety and human's health protection. Melamine can emit weak fluorescence, making it difficult to detect melamine directly. However melamine can significantly enhance

One of the primary objectives of planetary exploration is the search for signs of life (past, present, or future). Formulating an understanding of the geochemical processes on planetary bodies may allow us to define the precursors for biological processes, thus providing insight into the evolution of past life on Earth and other planets, and perhaps a projection into future biological processes. Several

Type II diabetes mellitus (T2DM) is a metabolic disorder that is characterized by chronically elevated glucose caused by insulin resistance. Although T2DM is manageable through insulin therapy, the disorder itself is a risk factor for much more dangerous diseases including cardiovascular disease, kidney disease, retinopathy, Alzheimer’s disease, and more. T2DM affects 450 million people worldwide

A benchtop Laser-Induced Breakdown Spectroscopy (LIBS) is demonstrated to determine the elemental carbon content present in raw coal used for combustion in power plants. The spectral intensities of molecular CN and C2 emission are measured together with the atomic carbon (C) and other inorganic elements (Si, Fe, Mg, Al, Ca, Na, and K) in the LIBS spectrum of coal. The emission persistence time of C2

Malaria is considered to be one of the most catastrophic health issues in the whole world. Vibrational spectroscopy is a rapid, robust, label-free, inexpensive, highly sensitive, non-perturbative and non-destructive technique with high diagnostic potential for the early detection of disease agents. In particular, the fingerprinting capability of Attenuated Total Reflection (ATR) spectroscopy is promising

We describe the wavelength calibration of the spectrometer for the Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) instrument onboard NASA’s Perseverance Rover. SHERLOC utilizes deep-UV Raman and fluorescence (DUV R/F) spectroscopy to enable analysis of samples from the martian surface. SHERLOC employs a 248.6 nm deep UV laser to generate Raman scattered

A linear Boltzmann plot was constructed using Cu I-lines of well-known atomic parameters. Aligning other spectral lines to the plot was adopted as a viable way to estimate the most probable values of Stark broadening parameters of Cu I-lines at 330.79, 359.91, and 360.2 nm. Plasma was generated by focusing of Nd: YAG laser radiation at wavelength 532 nm on a pure copper target in open air. Plasma emission

Discrete frequency infrared (DFIR) chemical imaging is transforming the practice of microspectroscopy by enabling a diversity of instrumentation and new measurement capabilities. While a variety of hardware implementations have been realized, considerations in the design of all-IR microscopes have not yet been compiled. Here we describe the evolution of IR microscopes, provide rationales for design

In this study, we explored the electronic structure of the surfaces of polyethylene samples having different crystallinities using attenuated total reflection (ATR)-far-ultraviolet (FUV) spectroscopy and quantum chemical calculations. Specifically, the ATR-FUV spectra of five types of high-density polyethylene (HDPE), six types of linear low-density PE (LLDPE), and seven types of low-density PE (LDPE)

A pair of ATR IR spectra obtained during the crystallization of bioplastic copolymer poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate] or PHBHx from the melt by spontaneous cooling were examined using the two-trace two-dimensional correlation spectroscopy (2T2D-COS) analysis. Unlike conventional difference spectra, 2T2D spectra showed unexpected details for the patterns of spectral intensity changes

Fluorescence-based single molecule techniques, mainly including fluorescence correlation spectroscopy (FCS) and single-molecule fluorescence resonance energy transfer (smFRET), are able to analyze the conformational dynamics and diversity of biological macromolecules. They have been applied to analysis of the dynamics of membrane proteins, such as membrane receptors and membrane transport proteins

Inter- and intramolecular interactions in multicomponent polymer systems influence their physical and chemical properties significantly and thus have implications on their synthesis and processing. In the present study, chemical images were obtained by plotting the peak position of a spectral band from the datasets generated by in-situ ATR-FTIR spectroscopic imaging. This approach was successfully

A technique for analyzing IR imaging data based on two-trace two-dimensional (2T2D) correlation analysis is presented to extract pertinent information underlying spectroscopic imaging data. In 2T2D correlation mapping, each spectrum in hyperspectral data is individually compared with a reference spectrum to generate 2T2D asynchronous correlation intensity at the x- and y-coordinates on a 2T2D correlation

Determination of elemental concentrations in biological tissue is fundamental to many environmental studies. Analytical methods typically used to quantify concentrations in such studies have minimum sample volumes that necessitate lethal or impactful collection of tissues. Laser-ablation inductively coupled mass spectrometry (LA-ICP-MS) has small sample-volume requirements and offers environmental

Photoacoustic spectroscopic (PAS) detection of infrared absorption often produces spectra with enhanced intensities for weaker peaks, enabling the detection of features due to overtones and combinations, as well as less-abundant isotopic species. To illustrate this phenomenon, we present and discuss PAS infrared spectra of calcite (CaCO3). We use linearization of rapid-scan spectra, as well as comparing

In this study, one of the thermoresponsive polymers, block copolymer consisting of poly(ethylene glycol) and poly(N-isopropylacylamide), was investigated using Fourier-transform infrared (FTIR) spectroscopy, principal component analysis (PCA), and two-dimensional correlation spectroscopy (2D-COS). The apparent trend of the spectral changes in the temperature-dependent FTIR spectra of poly(ethylene

In the study of laser-induced plasmas it is customary to use the branching ratio method for assessing the conditions of optically thin plasma, which are important for the application of analytical methods such Calibration-Free LIBS. In this communication, we warn on the possibility that in some circumstances, the branching-ratio method might give results close to the one characterizing optically thin

There is a great need for the analysis of the chemical composition, structure, functional groups and interactions at polymer–metal interfaces in terms of adhesion, corrosion, and insulation. Although atomic-force-microscopy-based infrared spectroscopy (AFM-IR) can provides chemical analysis with nanoscale spatial resolution, it generally requires to thin a sample to be placed on a substrate that

Raman spectroscopy (RS) has for decades been considered a promising tool for food analysis, but widespread adoption has been held back by e.g. high instrument costs and sampling limitations regarding heterogeneous samples. The aim of the present study was to use wide area RS in conjunction with surface scanning to overcome the obstacle of heterogeneity. Four different food matrices were scanned (intact

Using the recently discovered THORS phenomenon, it is possible to generate optically induced, local density barriers in air by the absorption of intense, modulated laser light (the THORS phenomenon), which results in abrupt differences in compressibility of the air at these barriers that can efficiently reflect incident acoustic waves. In this note, we demonstrate the ability to optically manipulate

The heterogeneity of metal island films electrodeposited on conductive metal oxide modified internal reflection elements is shown to provide a variable ATR-SEIRAS (attenuated total reflection surface enhanced infrared absorption spectroscopy) response. A self-assembled monolayer of a ferrocene-terminated thiol monolayer (FcC11SH) was formed on the gold islands covering a single substrate, which was

Quartz is the most abundant mineral on the earth’s surface. It is spectrally active in the longwave infrared (LWIR) region with no significant spectral features in the optical domain, i.e., visible–near-infrared–shortwave-infrared (Vis–NIR–SWIR) region. Several space agencies are planning to mount optical image spectrometers in space, with one of their missions being to map raw materials. However,

Terahertz (THz) time-domain spectroscopy provides a direct and nondestructive method for measuring the dielectric properties of materials directly from the phase delay of coherent electromagnetic radiation propagating through the sample. In cases when crystals are embedded within an inert polymeric pellet, the Landau, Lifshitz, and Looyenga (LLL) effective medium model can be used to extract the intrinsic

We describe the fabrication of an underwater time-gated standoff Raman sensor, consisting of a custom Raman spectrometer, custom scanner, and commercial diode-pumped pulsed 532-nm laser all located inside pressure housing. The Raman sensor was tested in the laboratory with samples in air, a tank containing tap water and seawater, and in the coastal Hawaiian harbor. We demonstrate our new system by

Conventional methods for measuring the concentration of deuterium in body fluids are by either isotope ratio mass spectrometry or Fourier transformed infra-red transmission (FTIR) spectroscopy. The latter method is often preferred as it is less expensive and time consuming; however, having a lower sensitivity means a larger sample volume is required. This study investigated an alternative FTIR spectroscopic

The resonance Raman spectra of bacterial carotenoids have been employed to identify bacterial strains and their intensity changes as a function of ultraviolet (UV) radiation dose have been used to differentiate between live and dead bacteria. In addition, the resonance-enhanced Raman spectra enabled us to detect bacteria in water at much lower concentrations (∼108 cells/mL) than normally detected spectroscopically

Online measurements of the raw gas composition, including tars and water, during biomass gasification provide valuable information in fundamental investigations and for process control. Mainly consisting of hydrocarbons, tars can, in principle, be measured using Fourier transform infrared (FT-IR) spectroscopy. However, an instrument subjected to raw gas runs the risk of condensation of tars on optical

Pottery sherds from Teotihuacan, Mexico, belonging to the Formative and Classic periods (150 BCE–700 CE) were investigated using laser-induced breakdown spectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP-OES). LIBS results show that most of the investigated samples have primarily the same elemental composition. Nevertheless, there are also a few sherds that could

Plastics have been increasingly used to create modern and contemporary art and design, and nowadays, museum collections hold numerous objects completely or partially made of plastics. However, the preservation of these materials is still a challenging task in heritage conservation, especially because some plastics show signs of degradation shortly after their production. In addition, different degradation

The chlorinity of deep-sea hydrothermal fluids, representing one of the crucial deep-sea hydrothermal indicators, indicates the degree of deep phase separation of hydrothermal fluids and water/rock reactions. However, accurately measuring the chlorinity of high-temperature hydrothermal fluids is still a significant challenge. In this paper, a piecewise chlorinity model to measure the chlorinity of

The knowledge of the spectroscopic parameters of the elemental emission lines is important for diagnostics of laser-induced plasmas and the application of calibration-free/fundamental parameters analytical methods. In this paper, we used the recently proposed Time-Independent Extended C-Sigma (TIECS) method for determining, for the first time, the transition probabilities and Stark broadening coefficients

The objective of this work is to demonstrate the potential of near infrared (NIR) spectroscopy for common screening of falsified medicines in the field by means of a device-independent universal discrimination approach. In order to provide a useful discrimination tool to protect people from low-quality medical products, not only is a low-cost and portable screening device necessary, but a reference

Tire evidence is a form of trace evidence that is often overlooked in today's forensics, while frequently found at crime or accident scenes, usually in the form of skid marks. The pattern of the tire skid mark has been used before to link a tire or car to a scene, but the widespread use of anti-lock braking systems makes this an almost impossible and abandoned route of analysis. With this is mind,

An optical diagnostic, based on laser-induced fluorescence (LIF), has been developed for on-engine measurements of real-time fuel dilution of engine oil, or fuel in oil (FiO). Fuel dilution of oil is broadly relevant to advancing engine technology including durability, calibration, and catalyst-system management, and believed to promote destructive stochastic pre-ignition (SPI) during high-load engine

The peroxide value (PV) of edible oils is a measure of the degree of oxidation, which directly relates to the freshness of the oil sample. Several studies previously reported in the literature have paired various spectroscopic techniques with multivariate analyses to rapidly determine PVs using field portable and process instrumentation; those efforts presented ‘best-case’ scenarios with oils from

In this article the total reflection X-ray fluorescence (TXRF) analysis was used for determination of element concentrations in three isolated peripheral blood components: lymphocytes, erythrocytes, and plasma, collected from 36 healthy donors (15 men and 21 women) from eastern Poland. The studied blood components were isolated from whole peripheral blood using Histopaque-1077 density gradient centrifugation

The energy efficiency of heterogeneous catalytic processes may be improved by using mid-infrared light to excite gas-phase reactants during the reaction, since vibrational excitation of molecules has been shown to increase their reactivity at the gas-catalyst interface. A primary challenge for such light-enabled catalysis is the need to ensure close coupling between light-excited molecules and the

Essential oils are complex mixtures of organic substances with large commercial importance in the pharmaceutical, food, fragrance, and cosmetic industries due to their organoleptic and biological properties. Also, these materials are also luminescent what has taken several studies about its potential uses for the detection and quality control of essential oils, imaging, and for the investigation of

This work aims to investigate changes induced by low energy radiation in adipose and muscular tissues employing autofluorescence and Raman spectroscopic techniques. X-rays beams expositions with 25 and 35 kV at 0.11, 1.1 and 2.1 Gy radiation dose levels were applied. Changes in Raman line intensities at specific bands assigned to collagen, proteins and lipids were observed. Autofluorescent analysis

The adipose tissue presents structural and functional changes in obesity and type 1 diabetes (T1DM). In obesity, the size and number of adipocytes and the adipokines' secretion increase. In T1DM, a loss of adipose tissue suggests changes in the metabolic activity of this tissue. A significant challenge is to find alternative non-invasive methods to evaluate molecular changes in adipose tissue related

Ammonia (NH3) is regarded as an important NOx precursor and also as an effective reductant for NOx removal in energy utilization through combustion, and it has recently become an attractive non-carbon alternative fuel. To have a better understanding of thermochemical properties of ammonia, accurate in-situ detection of ammonia in high temperature environments is desirable. Ultraviolet (UV) absorption

Algorithms to objectively compare the circular dichroism spectra of biopharmaceuticals, as a measure of consistent higher order structure, and are sensitive to errors in spectropolarimeter wavelength calibration. A public database, the Protein Circular Dichroism Data Bank [PCDDB] contains 108 unique calibration spectra of d-camphor-10-sulphonic acid [CSA], mainly collected on synchrotron-based instruments

Generation of CO2 from Nordic fulvic acid (FA) solution in the presence of goethite (α-FeOOH) were observed in FA-goethite interaction experiments at 25–80 °C. CO2 generation processes observed by gas cell infrared (IR) spectroscopy indicated two steps: the zeroth order slower CO2 generation from FA solution commonly occurring in the heating experiments of the FA in the presence and absence of

In recent years, the native food industry in Australia has increased in both value and volume due to the discovery of a wide range of phytochemicals (e.g. vitamin C, polyphenols) that have potential health benefits. Thus, plant organs and tissues of these native plants are used in a wide range of applications. In particular, the kernel of a native plum, the Kakadu plum (Terminalia ferdinandiana, Combretaceae)

There is growing interest in the use of algorithms to objectively compare near UV spectra of protein biopharmaceuticals in a regulated environment. Such use will require that the methods be validated, with ICH Q2(R1) currently being the key document. A key aspect of such validation is to understand how robust the method is to experimental variation. Noise-free simulated spectra, obtained by fitting

Qualitative and quantitative Raman and infrared (IR) measurements on NaNO3 solutions have been carried out over a wide concentration range (5.56 · 10-6 – 7.946 mol/L) in water and heavy water. The Raman spectra were measured from 4000 cm-1 to low wavenumbers at 45 cm-1. Band fit analysis on the profile of the 1047 cm-1 – band, ν1(a1') NO3- measured at high resolution at 0.85 cm-1 produced a small

The Attenuated Total Reflection (ATR) technique coupled with a microscope allows analysis of specimens without any preparation, spatially correlated with the specimen’s morphology. These characteristics make micro-ATR systems very useful for studying gemstones and in particular amber samples. Indeed, in this report the micro-ATR technique was used to characterize three Burmite samples, as case studies

Implementing remote, real-time spectroscopic monitoring of radiochemical processing streams in hot cell environments requires efficiency and simplicity. The success of optical spectroscopy for the quantification of species in chemical systems highly depends on representative training sets and suitable validation sets. Selecting a training set (i.e., calibration standards) to build multivariate regression

Raman spectroscopy has been used extensively to calculate CO2 fluid density in many geological environments, based on the measurement of the Fermi diad split (Δ; cm-1) in the CO2 spectrum. While recent research has allowed the calibration of several Raman CO2 densimeters, there is a limit to the inter-laboratory application of published equations. These calculate two classes of density values for

Spectroscopy rapidly captures a large amount of data that is not directly interpretable. Principal Components Analysis (PCA) is widely used to simplify complex spectral datasets into comprehensible information by identifying recurring patterns in the data with minimal loss of information. The linear algebra underpinning PCA is not well understood by many applied analytical scientists and spectroscopists