Laser-induced breakdown spectroscopy; Raman spectroscopy; Chemometrics; Bacteria;

In this work, we investigate the impact of data provided by complementary laser-based spectroscopic methods on multivariate classification accuracy. Discrimination and classification of five Staphylococcus bacterial strains and one strain of Escherichia coli is presented. The technique that we used for measurements is a combination of Raman spectroscopy and Laser-Induced Breakdown Spectroscopy (LIBS). Obtained spectroscopic data were then processed using Multivariate Data Analysis algorithms. Principal Components Analysis (PCA) was selected as the most suitable technique for visualization of bacterial strains data. To classify the bacterial strains, we used Neural Networks, namely a supervised version of Kohonen's self-organizing maps (SOM). We were processing results in three different ways - separately from LIBS measurements, from Raman measurements, and we also merged data from both mentioned methods. The three types of results were then compared. By applying the PCA to Raman spectroscopy data, we observed that two bacterial strains were fully distinguished from the rest of the data set. In the case of LIBS data, three bacterial strains were fully discriminated. Using a combination of data from both methods, we achieved the complete discrimination of all bacterial strains. All the data were classified with a high success rate using SOM algorithm. The most accurate classification was obtained using a combination of data from both techniques. The classification accuracy varied, depending on specific samples and techniques. As for LIBS, the classification accuracy ranged from 45% to 100%, as for Raman Spectroscopy from 50% to 100% and in case of merged data, all samples were classified correctly. Based on the results of the experiments presented in this work, we can assume that the combination of Raman spectroscopy and LIBS significantly enhances discrimination and classification accuracy of bacterial species and strains. The reason is the complementarity in obtained chemical information while using these two methods.

IODINE; DIAGNOSIS; PROTEIN; LEVEL

The thyroid is an important hormone regulation organ. Laser induced breakdown spectroscopy is developed to assess iodine and other essential elements in the thyroid . Subjects are administered 0.05% iodine water for 0, 6, and 12 days before the thyroid is extracted. Pronounced iodine, sodium, calcium, and potassium emissions are observed at approximately 746, 589, 395/422, and 766/770 nm, respectively. Iodine emission is surprisingly highest in 0 day subjects, lowest after 6 days, and recovers by 12 days. This follows the Wolff-Chaikoff effect as ingestion of excess iodine reduces thyroid iodine and iodine is essential for hormone production. LIBS is a promising method for trace elemental analysis of the thyroid. 

LIBS; Bacteria; Neural network; K-means; Spectroscopy;LIBS

LIBS technique was used to obtain spectra of Escherichia coli and Staphylococcus aureus for identifying characteristic emission lines and then they were analyzed by K-means classifier for neural network feasibility. The potential of this method for bacteria identification was demonstrated.

laser induced breakdown spectroscopy; electron density; plasma temperature; malignant tissue; quadrupole-mass spectroscopy;Q-SWITCHED NDYAG; OPTICAL-EMISSION; ORAL-CANCER; IN-VIVO; CARCINOMA; FLUORESCENCE; CONFINEMENT; ELEMENTS; PLASMAS; SITU

Here, the authors have utilized laser induced breakdown spectroscopy (LIBS) to distinguish cancerous tissues from normal ones. For this purpose, the plasma emission spectra of the normal and cancerous tissues taken from four different organs of interest, i.e, breast, colon, larynx, and tongue are analyzed via the excitation of a pulsed Neodymium-doped Yttrium Aluminum Garnet (ND: YAG) laser at 1064 nm. Results show that the abundance of the trace elements such as Ca, Mg, and Na trace elements are elevated in the cancerous tissues with respect to normal ones. In addition, inductively coupled plasma-optical emission spectroscopy and quadrupole-mass spectroscopy are employed to support the findings given by LIBS. Furthermore, the plasma characteristics such as temperature and electron density are probed by data processing of the plasma spectra at local thermal equilibrium condition as an alternative technique to discriminate between the normal and malignant tissues. It is shown that more energetic plasma is created on the neoplastic specimens resulting in higher electron density and plasma temperature due to the corresponding intense atomic/ionic characteristic emissions of species. The simplicity and low cost of processes benefits the physicians to encourage the clinical application of LIBS in near future. (C) 2017 Laser Institute of America.

Spectrum Analysis [E05.1962.867]; Laser-Induced Breakdown-Spectroscopy; Tissues [A10]; Optical Tissue Differentiation and Identification;NORMAL HUMAN ENAMEL; HUMAN TOOTH ENAMEL; LINGUAL NERVE; MINERAL-COMPOSITION; FEEDBACK MECHANISM; PERIPHERAL-NERVES; CHEMICAL-ANALYSIS; LIBS PROSPECTS; SURGICAL LASER; DENTAL-CARIES

Compared to conventional techniques, Laser surgery procedures provide a number of advantages, but may be associated with an increased risk of iatrogenic damage to important anatomical structures. The type of tissue ablated in the focus spot is unknown. Laser-Induced Breakdown-Spectroscopy (LIBS) has the potential to gain information about the type of material that is being ablated by the laser beam. This may form the basis for tissue selective laser surgery. In the present study, 7 different porcine tissues (cortical and cancellous bone, nerve, mucosa, enamel, dentine and pulp) from 6 animals were analyzed for their qualitative and semiquantitative molecular composition using LIBS. The so gathered data was used to first differentiate between the soft-and hard-tissues using a Calcium-Carbon emission based classifier. The tissues were then further classified using emission-ratio based analysis, principal component analysis (PCA) and linear discriminant analysis (LDA). The relatively higher concentration of Calcium in the hard tissues allows for an accurate first differentiation of soft-and hard tissues (100% sensitivity and specificity). The ratio based statistical dif-ferentiation approach yields results in the range from 65% (enamel-dentine pair) to 100% (nerve-pulp, cancellous bone-dentine, cancellous bone-enamel pairs) sensitivity and specificity. 

dental caries; ultra-short lasers; thermal effects; atomic spectroscopy;INDUCED BREAKDOWN SPECTROSCOPY; QUANTITATIVE-ANALYSIS; REPETITION-RATE; TISSUE; FLUORESCENCE; CARIES; LIBS; BONE; IDENTIFICATION; ENAMEL

The goal of this work is to investigate the thermal effects of femtosecond laser (fs-laser) ablation for the removal of carious dental tissue. Additional studies identify different tooth tissues through femtosecond laser induced breakdown spectroscopy (fsLIBS) for the development of a feedback loop that could be utilized during ablation in a clinical setting. Scanning Election Microscope (SEM) images reveal that minimal morphological damages are incurred at repetition rates below the carbonization threshold of each tooth tissue. Thermal studies measure the temperature distribution and temperature decay during laserablation and after laser cessation, and demonstrate that repetition rates at or below 10kHz with a laser fluence of 40 J/cm(2) would inflict minimal thermal damage on the surrounding nerve tissues and provide acceptable clinical removal rates. Spectral analysis of the different tooth tissues is also conducted and differences between the visible wavelength fsLIBS spectra are evident, though more robust classification studies are needed for clinical trans-lation. These results have initiated a set of precautionary recommendations that would enable the clinician to utilize femtosecond laser ablation for the removal of carious lesions while ensuring that the solidity and utility of the tooth remain intact. 

PLASMA-MASS SPECTROMETRY; INDUCED BREAKDOWN SPECTROSCOPY; LASER-ABLATION; RESOLUTION; CHEMISTRY; TISSUES; METALS; CU

Elemental imaging is regarded as a valuable approach for a wide application range in modern medicine. Using tandem laser-ablation laser-inducedbreakdown spectroscopy (LA LIBS) coupled to inductively coupled plasma mass spectrometry (ICP-MS), high-sensitivity detection of trace metals can be combined with the possibility of analyzing nonmetallic bulk components of biological samples (for example, carbon, hydrogen, and oxygen). In this work, the applicability of the tandem LA LIBS approach for the laterally resolved elemental analysis of a mouse model tumor sample after administering cytostatic medication is demonstrated. Results show that trace elements can be detected using the LA-ICP-MS domain of the setup while major components of the samples are analyzed simultaneously using LIBS. By expanding the analyte range covered during one analysis, information could be extracted from the data set that is not accessible to either of the stand-alone analysis methods.

laser-induced breakdown spectroscopy; eutectic glass; bioactive materials;FLOATING-ZONE TECHNIQUE; WOLLASTONITE-TRICALCIUM PHOSPHATE; EUTECTIC GLASS-CERAMICS; ND3+ IONS; WAVE-GUIDES; IN-VIVO; BIOCERAMICS; COMPOSITE; STRESSES; GROWTH

Laser-induced breakdown spectroscopy (LIBS) is applied to characterize the formation of porous hydroxyapatite layers on the surface of 0.8CaSiO(3)-0.2Ca(3)(PO4)(2) biocompatible eutectic glass immersed in simulated body fluid (SBF). Compositional and structural characterization analyses were also conducted by field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), and micro-Raman spectroscopy.

CHRONIC HEPATITIS-C; RAT-LIVER; FIBROSIS; LIBS; FEASIBILITY; IDENTIFICATION; BACTERIAL; SAMPLES

Hepatic cirrhosis is a major cause of morbidity and mortality worldwide due to hepatitis C, alcoholism and fatty liver disease associated with obesity. Assessment of hepatic fibrosis relies in qualitative histological evaluation of biopsy samples. This method is time-consuming and depends on the histopathologists' interpretation. In the last decades, non-invasive techniques were developed to detect and monitor hepatic fibrosis. Laser-induced breakdownspectroscopy (LIBS) is a good candidate for a real-time, independent and fast technique to diagnose hepatic fibrosis. In this work LIBS was employed to characterize rat liver tissues with different stages of fibrosis. Depth profiling measurements were carried out by using a nanosecond Nd:YAG laser operated at the fundamental wavelength and an echelle spectrometer coupled with an ICCD camera. Due to the soft nature of the samples, plasma conditions largely change between consecutives shots. Thus, a theoretically supported procedure to correct the spectral line intensities was implemented. This procedure allows the reduction of the intensities' dispersion from 67% to 12%. After the correction, the LIBS signal shows an enhancement in calcium intensity by a factor of three as the fibrosis progressed. Calcium is known to increase crosslinking of extracellular matrix proteins in the fibrous septa. Therefore, our result singles it out as a key participant in the hepatic fibrosis. (C) 2017 Optical Society of America

LIBS imaging; Elemental imaging; Human paraffin-embedded tissue; Skin cancer;PLASMA-MASS SPECTROMETRY; SQUAMOUS-CELL CARCINOMA; X-RAY MICROSCOPY; LA-ICP-MS; BIOLOGICAL TISSUE; NANOPARTICLES; SKIN; RESOLUTION; ELEMENTS; METALS

Chemical elements play central roles for physiological homeostasis in human cells, and their dysregulation might lead to a certain number of pathologies. Novel imaging techniques that improve the work of pathologists for tissue analysis and diagnostics are continuously sought. We report the use of Laser-Induced Breakdown Spectroscopy (LIBS) to perform multi-elemental images of human paraffin-embedded skin samples on the entire biopsy scale in a complementary and compatible way with microscope histopathological examination. A specific instrumental configuration is proposed in order to detect most of the elements of medical interest (i.e. P, Al, Mg, Na, Zn, Si, Fe, and Cu). As an example of medical application, we selected and analysed skin biopsies, including healthy skin tissue, cutaneous metastasis of melanoma, Merkel-cell carcinoma and squamous cell carcinoma. Clear distinctions in the distribution of chemical elements are observed from the different samples investigated. This study demonstrates the high complementarity of LIBS elemental imaging with conventional histopathology, opening new opportunities for any medical application involving metals. (C) 2017 Elsevier B.V. All rights reserved.

LIBS; Mineral composition; Analytical technique; Food; Chemometrics;PLANT MATERIALS; WHEAT-FLOUR; CLASSIFICATION; ADULTERATION; SPECTROMETRY; IDENTIFICATION; CHEMOMETRICS; VALIDATION; EMISSION; STANDARD

Background: Laser-induced breakdown spectroscopy (LIBS) is an atomic emission spectroscopic technique which uses a focused pulsed laser beam to generate plasma from the material. The plasma contains atoms, ions and free electrons which emit electromagnetic radiation as the plasma cools down. The emitted light is resolved by a spectrometer to form a spectrum. Recently, LIBS has become an emerging analytical technique for characterisation and identification of materials; its multi-elemental analysis, fast response, remote sensing, little to no sample preparation, low running cost and ease of use make LIBS a promising technique for the food sector. Scope and approach: The present article reviews the feasibility of LIBS for food analysis. It presents recent progress and applications of LIBS as an efficient and reagent-free, at-line tool capable of replacing traditional time-consuming analytical methods for assessing the quality and composition of food products. An overview of LIBS fundamentals, instrumentation and statistical data analysis is also provided. Key findings and conclusions: Although LIBS technology shows many advantages, challenges remain in terms of sample preparation, matrix effects, spectral pre-processing, model calibration and instrument development. (C) 2017 Elsevier Ltd. All rights reserved.

NIR SPECTROSCOPY; DATA NORMALIZATION; MOTION CONDITIONS; INFANT FORMULA; DIETARY-SODIUM; BLOOD-PRESSURE; MEAT; LIBS; CLASSIFICATION; PREDICTION

Beef is a rich source of important minerals, with potassium (K) being the most abundant mineral quantitatively except in cured meats where sodium (Na) from the added salt predominates. This study evaluates the capability of LIBS for quantification of the Na and K contents of minced beef as a potential method of detecting beef kidney adulteration. Additionally, the study aims to demonstrate the ability of LIBS to provide spatial mineral information of minced beef. A LIBS system was employed to collect spectral information of adulterated minced beef samples. Atomic absorption spectroscopy (AAS) was used to obtain reference values for Na and K. The chemometric technique of partial least squares regression (PLSR) was used to build the prediction models. Spatial mineral maps of minced beef samples were generated based on the predicted percentages of Na and K. The models for Na and K yielded calibration coefficients of determination (R-c(2)) of 0.97 and 0.91 respectively. Similarly, a good calibration model was obtained for adulteration yielding a R-c(2) of 0.97. Good prediction accuracy was observed for all models. Spatial mapping provided two major advantages: (a) representative measurements of samples and (b) spatial distribution of multi-elements. The results observed illustrate the ability of LIBS combined with chemometrics as a potential monitoring tool for mineral quantification as well as adulteration detection for the meat processing industry.

RISK-ASSESSMENT; PLANT MATERIALS; LIBS; PELLETS

In seeking a novel method with the ability of green analysis in monitoring toxic heavy metals residue in fresh leafy vegetables, laser-induced breakdownspectroscopy (LIBS) was applied to prove its capability in performing this work. The spectra of fresh vegetable samples polluted in the lab were collected by optimized LIBS experimental setup, and the reference concentrations of cadmium (Cd) from samples were obtained by conventional atomic absorption spectroscopy after wet digestion. The direct calibration employing intensity of single Cd line and Cd concentration exposed the weakness of this calibration method. Furthermore, the accuracy of linear calibration can be improved a little by triple Cd lines as characteristic variables, especially after the spectra were pretreated. However, it is not enough in predicting Cd in samples. Therefore, partial least-squares regression (PLSR) was utilized to enhance the robustness of quantitative analysis. The results of the PLSR model showed that the prediction accuracy of the Cd target can meet the requirement of determination in food safety. This investigation presented that LIBS is a promising and emerging method in analyzing toxic compositions in agricultural products, especially combined with suitable chemometrics. (C) 2017 Optical Society of America

medicinal herbs; essential and toxic metals; LIBS; ICP OES; chemometrics;INDUCED BREAKDOWN SPECTROSCOPY; PRINCIPAL COMPONENT ANALYSIS; TRACE-ELEMENTS; NEUTRON-ACTIVATION; INFUSIONS; INFORMATION; FINGERPRINT; CALCIUM; PLANTS; HONEY

Essential and toxic metals were determined in eighteen samples of medicinal herbs from Poland, Lithuania and Serbia by means of laser-induced breakdownspectroscopy (LIBS) and inductively coupled plasma optical emission spectrometry (ICP OES). Calcium, K and Mg concentrations were obtained in % (m/m) and other metals (Na, Co, Cu, Fe, Mn, Ni, Zn, Cd, Cr and Pb) in mg kg-1. The fact that the herb samples analyzed belonged to specific plant species and represented different morphological plant parts explained the characteristic distribution in two-dimensional scores plots obtained by principal component analysis (PCA). A strong correlation of LIBS results was achieved in comparison to those obtained by ICP OES for Ca, K and Mg. Differences in the types of infusions were observed, in that leaves are related to Zn and Ni concentrations, leaves and flowers to Co, Ca and Mn concentrations and flowers to K, Na, Mg and Fe content.

Laser-induced breakdown spectroscopy; femtosecond LIBS; fs-LIBS; amalgam; dental restoration; mercury;INDUCED BREAKDOWN SPECTROSCOPY; RESTORATIVE DECISION-MAKING; RESIN-BASED COMPOSITE; PERMANENT TEETH; DENTAL AMALGAM; GLASS-IONOMER; LONGEVITY; REPLACEMENT; TOXICOLOGY; MIGRATION

In this work the diffusion of mercury and other elements from amalgam tooth restorations through the surrounding dental tissue (dentin) was evaluated using femtosecond laser-induced breakdown spectroscopy (fs-LIBS). To achieve this, seven deciduous and eight permanent extracted human molar teeth with occlusal amalgam restorations were half-sectioned and analyzed using pulses from a femtosecond laser. The measurements were performed from the amalgam restoration along the amalgam/dentin interface to the apical direction. It was possible to observe the presence of metallic elements (silver, mercury, copper and tin) emission lines, as well as dental constituent ones, providing fingerprints of each material and comparable data for checking the consistence of the results. It was also shown that the elements penetration depth values in each tooth are usually similar and consistent, for both deciduous and permanent teeth, indicating that all the metals diffuse into the dentin by the same mechanism. We propose that this diffusion mechanism is mainly through liquid dragging inside the dentin tubules. The mercury diffused further in permanent teeth than in deciduous teeth, probably due to the longer diffusion times due to the age of the restorations. It was possible to conclude that the proposed femtosecond-LIBS system can detect the presence of metals in the dental tissue, among the tooth constituent elements, and map the distribution of endogenous and exogenous chemical elements, with a spatial resolution that can be brought under 100 mu m.

laser induced breakdown spectroscopy; teeth; caries; enamel; calcium; phosphorus; zinc;DENTAL-CARIES; ZINC-DEFICIENCY; ENAMEL; MODELS; SR

The aim of this work is a multi-component analysis of the element composition of the enamel and carious parts of teeth and the quantification of enamel demineralization using laser-induced breakdown spectroscopy (LIBS). For each tooth the P/Ca ratios of the emission line intensities in the enamel part and those in the carious regions were compared. Since zinc is a trace element, the same procedure was performed for Zn/Ca ratios in the enamel and carious parts. These comparisons showed that the mineral loss from carious lesions occurs at different rates for the studied elements. Calcium has the highest casualty rate. On the other hand, the zinc level diminishes also in the carious region but at a lower rate. The lines were obtained from plume plasma emission generated on the enamel and carious regions.

laser-induced breakdown spectroscopy; Pu'er tea leaves; quantitative measurement; external standard method; internal standard method; multiple linear regression method;WATER SOLUTION; LIBS; CALIBRATION; CHROMIUM; CR

Laser-induced breakdown spectroscopy (LIBS) is applied at natural atmosphere to compare the quantitative analysis performances of the toxic heavy metal element lead (Pb) in Pu'er tea leaves, determined by three calibration methods: the external standard method, the internal standard method, and the multiple linear regression method. The Pb I line at 405.78 nm is chosen as the analytical spectral line to perform the calibration. The linear correlation coefficients (R (2) ) of the predicted concentrations versus the standard reference concentrations determined by the three methods are 0.97916, 0.98462, and 0.99647, respectively. The multiple linear regression method gives the best performance with respect to average relative errors (ARE = 2.69%), maximum relative errors (MRE = 4.94%), average relative standard deviations (ARSD = 9.69%) and maximum relative standard deviations (MRSD = 24.44%) of the predicted concentrations of Pb in eight samples, compared to the other two methods. It is shown that the multiple linear regression method is more accurate and stable in predicting concentrations of Pb in Pu'er tea leaf samples.

Laser induced breakdown spectroscopy; Chinese cabbage; Cadmiun; Variable screening;HEAVY-METALS; LIBS

Heavy metal residue in vegetables is a big concern in the whole world. The aim of this work is to explore the effect of multivariable selection on analyzing Cd in Chinese cabbage polluted in lab by collecting the spectra of laser induced breakdown spectroscopy (LIBS) from the samples. At the same time, the actual Cd content in samples was obtained by anodic stripping voltammetry (ASV). The LIBS spectral range in partial least square (PLS) model was screened by standard normal variable transformation (SNV), first derivative (FD), second derivative (SD) and center treatment (CT) for preprocessing spectra and the optimized method was used for the analysis of interval partial least square (iPLS) and synergy interval partial least square (SiPLS). The results indicated that the method of CT was the best as a comparison with PLS, iPLS and SiPLS. And the intervals of wavelength were 214.72-215.82 nm, 215.88-216.97 nm and 225.08 -226.35 nm by utilizing the optimized SiPLS. Here the root mean square error of cross validation (RMSECV) between real content and predicted ones was 1.487, the root mean squared error of prediction (RMSEP) was 1.094, the correlation coefficient (R) was 0.9942, and the average relative error (ARE) was 11.60%. The results displayed that LIBS could predict Cd in vegetables by multivariable selection of SiPLS and the accuracy could meet the requirement of rapid and green analysis of Cd in vegetables.

LIBS; WD-XRF; FTIR; UV-Visible; Cyperus rotudus; Macro and Micronutrient Minerals;INDUCED BREAKDOWN SPECTROSCOPY; MEDICINAL-PLANTS; HEAVY-METALS; WHEAT; ACCUMULATION; SPECTROMETRY; REFLECTANCE; GALLSTONES

In the present study, a spectroscopic investigation of Cyperus rotundus using wavelength dispersive X-ray fluorescence (WD-XRF), laser-induced breakdownspectroscopy (LIBS), Fourier-transform infrared spectroscopy and Ultra Violet Visible (UV-Vis) spectroscopy have been performed. The macro and micronutrient minerals detected and quantified in Cyperus rotundus were carbon (C), oxygen (O), sodium (Na), chlorine (Cl), magnesium (Mg), silicon (Si), potassium (K), calcium (Ca), sulfur (S), phosphorous (P), aluminium (Al), iron (Fe), zinc (Zn), manganese (Mn), palladium (Pd), ruthenium (Ru), chromium (Cr), molybdenum (Mo), strontium (Sr), copper (Cu), and nickel (Ni). The minerals detected in Cyperus rotundus using WD-XRF technique was compared with the data obtained from LIBS technique. We have discussed about the medicinal importance of some of the nutrients found in Cyperus rotundus. FTIR spectroscopy has been used to study the molecular composition of Cyperus rotundus. UV-Vis spectroscopy has also been used to study the titled sample to know its molecular composition.

LIBS; FTIR Spectroscopy; Calcium Oxalate; Kidney Stones; Mineral Elements;

In the present work, spectroscopic investigations have been performed on a kidney stone to determine its chemical composition using Fourier transform infra-red (FTIR) spectroscopy and laser-induced breakdown spectroscopy (LIBS). Fourier transform infra-red (FTIR) spectroscopy were used to classification of stone's type and also to determine its minor constituents. Using FTIR spectroscopy, we have detected calcium oxalate as a major constituent of kidney stone and hence classified as oxalate stone. We have also observed the presence of calcium carbonate in calcite form and calcium phosphate in the kidney stone sample. LIBS has been used to detect the elemental content of kidney stone which were calcium (Ca), silicon (Si), tin (Sn), potassium (K), magnesium (Mg), iron (Fe), copper (Cu), titanium (Ti), fluorine (F), carbon (C), and nitrogen (N). This paper demonstrates FTIR and LIBS as a promising, simple, and accurate analytical method to study kidney stones.

Laser induced breakdown spectroscopy; Carrot; Elements; Curve fitting analysis; Plasma characterization;

The elemental composition of the carrot root was investigated by the laser induced breakdown spectroscopy by recording its emission spectrum. The recorded spectrum of carrot root pellet showed the presence of atomic lines of inorganic element as potassium (K), sodium (Na), iron (Fe), calcium (Ca), titanium (Ti), zinc (Zn), mercury (Hg), copper (Cu), magnesium (Mg), strontium (Sr), and cobalt (Co) while spectrum of fresh raw carrot depicted additional organic element as carbon (C), hydrogen (H), nitrogen (N) and oxygen (O). The produced plasma was characterized by characteristic parameters like plasma temperature, electron density, Lorentz fitting etc.

hyperspectral imaging; laser-induced breakdown spectroscopy; biomedical application;

Hyperspectral imaging (HSI) can be used to quickly and non-invasively monitor both physical and morphological characteristics as well as intrinsic chemical and molecular information about tissue pathology. Laser-induced breakdown spectroscopy (LIBS) is an elemental analysis technique that is based on atomic emission spectroscopy and laser plasma emission spectroscopy. In this paper, we use both HIS and LIBS to quantitatively distinguish the organs of mice including brain, heart, liver, lung, kidney and spleen from their different reflectance spectra and LIBS spectra, respectively. The two approaches presented here provide complementary functional information and may have potential biomedical applications for early disease detection and diagnosis.

Acoustic Radiation Force Elasticity Microscope(ARFEM); Laser induced breakdown spectroscopy (LIBS); Ultrasonic transducer; Femtosecond laser; Corneal elasticity;STRENGTH

The unique spatial distribution of corneal elasticity is shown by the nonhomogeneous structure of the cornea. It is critical to understanding how biomechanics control corneal stability and refraction and one way to do this job is non-invasive measurement of this distribution. Femtosecond laser pulses have the ability to induce optical breakdown and produced cavitation in the anterior and posterior cornea. A confocal ultrasonic transducer applied 6.5 ms acoustic radiation force-chirp bursts to the bubble at 1.5 MHz while monitoring bubble position using pulse-echoes at 20 MHz. The laser induced breakdown spectroscopy(LIBS) were measured in the anterior and posterior cornea with the plasmas that induced by the same femtosecond laser to see whether the laser inducedplasmas signals will show relationship to Young's modulus.

Chinese traditional medicine; elemental analysis; laser-induced breakdown spectroscopy; lead and copper;ATOMIC-ABSORPTION-SPECTROMETRY; GANNAN NAVEL ORANGE; ENVIRONMENTAL-POLLUTION; QUANTITATIVE-ANALYSIS; CONTAMINATED SOILS; SUNFLOWER PLANTS; HEAVY-METALS; LIBS; CADMIUM; CLASSIFICATION

Laser-induced breakdown spectroscopy was used for the analysis of the Chinese traditional medicine, Ligusticum wallichii. The laser energy and delay time were optimized to obtain best spectral quality. The limits of detection for lead and copper were 15.7 and 6.3 mu gg(-1), respectively. Multiple linear regression models between the laser-induced breakdown spectroscopy intensity and the mass fraction of lead and copper were constructed. Good agreement was observed between the actual concentrations and predicted values obtained by the models. These results demonstrate that the laser-induced breakdownspectroscopy coupled with multiple linear regression is suitable for the determination of heavy metals in Chinese traditional medicine.

Cadmium and hexavalent chromium; laser-induced breakdown spectroscopy (LIBS); lead, quantitative analyses; plant materials;PLASMA-MASS-SPECTROMETRY; NEAR-INFRARED SPECTROSCOPY; ARTIFICIAL NEURAL-NETWORK; GANNAN NAVEL ORANGE; POWDER SAMPLES; DOUBLE-PULSE; IN-SITU; MULTIVARIATE-ANALYSIS; ELEMENTAL ANALYSIS; ATOMIC-ABSORPTION

Bearing the merits of rapid, minimally destructive, and simultaneous multi-element analyses, laser-induced breakdown spectroscopy (LIBS) shows its unique advantages in quantitative analyses of lead, cadmium, and hexavalent chromium in plant materials. However, the greatest challenge LIBS must confront is calibration. Various methods for calibration are proposed and put into effect; nevertheless, limits of detection acquired by LIBS are not acceptable when they are compared with the maximum residue limits drawn up by governments, and LIBS's performances in quantitative analyses are to be improved. This review summarizes recent studies of analyzing lead, cadmium, and hexavalent chromium in plant materials quantitatively by LIBS; weighs the strengths and weaknesses of their calibration methods; and recommends the combination of matrix-matched standards based on spiked sample materials and internal standard as well as chemometrics in complicated situations for calibration in LIBS. Selecting the emission line of the analyte, sample enrichment and signal enhancement are measures that this review puts forward to improve the performances of LIBS in calibration. These quantitative analyses of lead, cadmium, and hexavalent chromium in plant materials by LIBS provide an opportunity to be utilized in mapping distributions and remediation for soil and water, as well as supervision for agricultural products safety and pollution treatments.

laser induced breakdown spectroscopy (LIBS); Acoustic Radiation Force Elasticity Microscope(ARFEM); ultrasonic transducer; Femtosecond laser; corneal elasticity;STRENGTH

The nonhomogeneous structure of the cornea suggests a unique spatial distribution of corneal elasticity. Non-invasive measurement of this distribution is critical to understanding how biomechanics control corneal stability and refraction. Femtosecond laser pulses induced optical breakdown and produced cavitation in the anterior and posterior cornea. A confocal ultrasonic transducer applied 6.5 ms acoustic radiation force-chirp bursts to the bubble at 1.5 MHz while monitoring bubble position using pulse-echoes at 20 MHz. The laser induced breakdown spectroscopy (LIBS) were measured in the anterior and posterior cornea to see whether the laser induced plasmas signals will show relationship to Young's modulus.

INDUCED BREAKDOWN SPECTROSCOPY; QUANTUM DOTS; MICROSPHERE IMMUNOASSAY; COATINGS; BARCODES

We provided a microbeads preparation method with reversed-phase microemulsion and ultraviolet light curing for laser induced breakdown spectroscopybased digital encoding suspension array. By combining reversed-phase microemulsion and ultraviolet light curing together, we created an one-step system for preparation of microbeads. The stability and universality of this method had been confirmed in preparation of microbeads with different encoding materials. With further experiments in surface modification and multiplexed detection, we proved that the synthesized microbeads were available to prepare suspension array and could provide accurate encoding performance in multiplexing.

Laser-Induced Breakdown Spectroscopy (LIBS); tooth decay; caries; demineralization; element analysis;DECIDUOUS TEETH

The carious decay develops a tiny area of demineralization on the enamel, which could be detected by element analytic techniques such as laser-inducedbreakdown spectroscopy (LIBS). That demineralization can quickly turn into a large lesion inside the tooth, it is often discovered too late to prevent the kind of decay that leads to cavities. The same optical LIBS detection approach could be used for monitoring of the caries removal using laser ablation or drilling techniques. For LIBS measurements we applied LIBS 2500Plus (Ocean Optics Inc., Dunedin, USA) system, which consists of seven spectrometric channels, covering spectral region from 200 to 980 nm, which optical resolution 0,05 nm, the spectrometers are connected with sample fiber bundle for 7-channels spectral system to the chamber for solid and liquid samples, Q-switched Nd:YAG laser, at 1 064 nm, with energy per pulse - 40 mJ, which is applied to induce plasma in the samples. LIBS spectra were obtained after single shot of the laser in the region of pathology. Samples investigated by LIBS are extracted teeth from patients, with periodontal problems on different stage of carious lesions, and their LIBS spectra are compared with the LIBS signals obtained from normal enamel and dentine tissues to receive complete picture of the carious lesion development. The major line of our investigations is related to the development of a methodology for real-time optical feedback control during selective ablation of tooth tissues using LIBS. Tooth structures, with and without pathological changes, are compared and their LIBS element analysis is used to differentiate major changes, which occur during tooth carious process and growth.

Biological sample; elemental composition; laser induced breakdown spectroscopy (LIBS); nail disorder; pathological nail;HUMAN FINGERNAILS

This study investigated the elemental composition of pathological and normal nails, according to different age groups and genders. The nail elemental composition was analyzed by using Laser Induced Breakdown Spectroscopy (LIBS) technique. A Q-switched Nd: YAG laser at 1064 nm with output energy of 100 mJ, pulse duration of 6 ns and repetition rate of 1 Hz was fired to the human nails sample. The laser pulse ablated the target sample surface and produced plasma plume with characteristic spectral line comprising sample's elemental composition. The plasma emission spectrum of nail samples were captured by fibre optic detection device and spectrometer equipped with ASEQ Spectra Software for elemental analysis. The elements detected in nails were Mg, Al, Ca, P, Ti, K and Na. Classification of nails into different age groups and genders demonstrate efficient results if compared with Dietary Reference Intakes (DRI). The results indicate that Ca, Al, Ti, P and K composition were higher among female. However, Mg and Na were higher among male. The results also show that Ca and K element decline as the age increase in both genders. The pathological nails' elemental compositions were also noticeably related to the nail disorder condition itself. It is proven that LIBS could be a possible method for analyzing the nails and identification of various nail disorders.

analysis; crushing strength; friability; hardness; LIBS; magnesium stearate; spectroscopy; surface; tablet; tartaric acid;INDUCED BREAKDOWN SPECTROSCOPY; MAGNESIUM STEARATE; QUANTITATIVE-ANALYSIS; COMPRESSION

Surface erosion of uncoated tablets results in processing problems such as dusting and defects during coating and is governed by the strength of particle bonding on tablet surface. In this study, the correlation between dusting tendency of tablets in a coating pan with friability and laser ablation surface hardness was assessed using tablets containing different concentrations of magnesium stearate and tartaric acid. Surface erosion propensity of different batches was evaluated by assessing their dusting tendency in the coating pan. In addition, all tablets were analyzed for crushing strength, friability, modified friability test using baffles in the friability apparatus, and weight loss after laser ablation. Tablets with similar crushing strength showed differences in their surface erosion and dusting tendency when rotated in a coating pan. These differences did not correlate well with tablet crushing strength or friability but did show reasonably good correlation with mass loss after laser ablation. These results suggest that tablet surface mass loss by laser ablation can be used as a minipiloting (small-scale) tool to assess tablet surface properties during early stages of drug product development to assess the risk of potential large-scale manufacturing issues. (C) 2016 American Pharmacists Association (R). Published by Elsevier Inc. All rights reserved.

MEAT; PLANT

Meat can be polluted by heavy metals during the feeding of livestock and processing of meat. It is necessary to monitor the concentration of toxic metals in meat. The element chromium (Cr) in pork was selected as a determination target for this work. Fresh pork was polluted in a Cr solution to create a different content level, then dried and pressed into pellets to eliminate the effect of water and improve the stability and sensitivity of laser-induced breakdownspectroscopy (LIBS). The spectra of pressed pellets were collected at optimized LIBS experimental parameters. After that, the real content of samples was obtained by atomic absorption spectroscopy. Characteristic lines Cr I 425.43, Cr I 427.48, and Cr I 428.97 were verified, and a model comparing the LIBS intensity of the line peak and the actual concentration of Cr was constructed. The results showed that the model has better predicted precision and accuracy, especially applying the line Cr I 425.43 for calibration. This work makes it obvious that LIBS has food safety potential for detecting residue of heavy metals in meat. (C) 2016 Optical Society of America

Laser-induced breakdown spectroscopy; LIBS; Mapping; Trace elements; Phytoremediation; Cancer; Plant; Bacteria; Animal tissues;

Laser-Induced Breakdown Spectroscopy (LIBS) is a sensitive optical technique capable of fast multi-elemental analysis of solid, gaseous and liquid samples. Since the late 1980s LIBS became visible in the analytical atomic spectroscopy scene; its applications having been developed continuously since then. In this paper, the use of LIBS for trace element determination in different matrices is reviewed. The main emphasis is on spatially resolved analysis of microbiological, plant and animal samples.

Metallomics and metalloproteomics are emerging fields addressing the role, uptake, transport and storage of trace metals essential for life. There are several main approaches that are being developed in metallomics and metalloproteomics including both detection of levels and spatial distribution of heavy metals and determination of heavy-metal-contained proteins. The aim of this work is detection of copper and zinc in healthy and tumour tissues of miniature pigs by using of the laser induced breakdown spectroscopy (LIBS). Concentration of heavy metal transporting protein metallothionein (MT) was determined by Brdicka reaction. Tissue cryosections were obtained from the MeLiM strain of miniature pigs with hereditary melanoma, particularly from healthy skin, cutaneous nodular melanomas and metastases in the liver, spleen and lymph nodes. Using LIBS we measured maps of spatial distribution of the essential heavy metals in cryosections and found that the maps of healthy and tumour cryosection markedly differed. The highest content of MT was determined in the tumours localised on the back of animals and was nearly 500 ug of MT per gram of tissue.