Characterization of Stromatolite Organic Sedimentary Structure Based on Spectral Image Fusion.

This paper evaluates the potential application of Raman baselines in characterizing organic deposition. Taking the layered sediments (Stromatolite) formed by the growth of early life on the Earth as the research object, Raman spectroscopy is an essential means to detect deep-space extraterrestrial life. Fluorescence is the main factor that interferes with Raman spectroscopy detection, which will cause the enhancement of the Raman baseline and annihilate Raman information. The paper aims to evaluate fluorescence contained in the Raman baseline and characterize organic sedimentary structure using the Raman baseline. This study achieves spectral image fusion combined with mapping technology to obtain high spatial and spectral resolution fusion images. To clarify that the fluorescence of organic matter deposition is the main factor causing Raman baseline enhancement, 5041 Raman spectra were obtained in the scanning area of 710 µm × 710 µm, and the correlation mechanism between the gray level of the light-dark layer of the detection point and the Raman baseline was compared. The spatial distribution of carbonate minerals and organic precipitations was detected by combining mapping technology. In addition, based on the BI-IHS algorithm, the spectral image fusion of Raman fluorescence mapping and reflection micrograph, polarization micrograph, and orthogonal polarization micrograph are realized, respectively. A fusion image with high spectral resolution and high spatial resolution is obtained. The results show that the Raman baseline can be used as helpful information to characterize stromatolite organic sedimentary structure.

Elastic Particle Swarm Optimization for MarSCoDe Spectral Calibration on Tianwen-1 Mars Rover.

China's Tianwen-1 Mars rover carries a laser-induced breakdown spectroscopy (LIBS) payload named MarSCoDe to analyze the mineral and rock composition on Mars. MarSCoDe is expected to experience a wide working temperature range of about 100 °C, which will lead to a spectral shift of up to ∼40 pixels (∼8.13 nm). Even worse, drastic changes in temperature and environment may cause a loss or increase of some spectral lines of an on-board calibration Ti target. An elastic particle swarm optimization (PSO) approach is proposed to fulfill the on-board spectral calibration of MarSCoDe under this harsh condition. Through establishing a standard wavelength set (SWS) and an individual particle wavelength set (PWS), and further elastically selecting a part of PWS to compare with SWS, the problem of spectral shift and number mismatch can be solved gradually with the evolution of the particle swarm. Some tests of standard lamps and Ti with MarSCoDe, placed in a Mars simulation environment chamber (MSEC) in a temperature range of 70 °C, were completed. Compared with the standard spectrum of the Ti target (obtained at 20 °C), the spectral shifts of the first, second, and third channels are approximately 0.33 nm (5 pixels), 0.85 nm (6.4 pixels), and 8.09 nm (39.8 pixels), respectively, at -40 °C before correction; after PSO correction, the spectral shifts are greatly reduced to up to 0.015 nm, and specially for the 626.28 nm line, the spectral shift is reduced from 8.09 nm to about 0 nm. Experimental results demonstrate that the PSO-based approach can not only correct the on-board spectral shift but also solve the number mismatch of spectral lines of MarSCoDe in the harsh working environment of Mars. Further, it can be extended to the on-board calibration of other spectral payloads for deep space exploration.

Theoretical studies of the EPR parameters and local structures for the two Cu2+ centers in Cd(HCOO)2 ·2H2 O.

Based on the studies of the electron paramagnetic resonance parameters for two types of the Cu2+ centers in Cd(HCOO)2 ·2H2 O by using the high-order perturbation formulas for a 3d9 ion in a rhombically elongated octahedron, local structure of the doped copper ion is determined. Research suggests that the impurity Cu2+ replaces the host Cd2+ and undergoes the local rhombic elongation distortion, characterized by the axial elongation ratios of 4.1%, and 3.8% along the z-axis and the planar bond length variation ratios of 3.8%, and 3.1% along the x-axis and y-axis, for Cu2+ Centers, I and II, respectively. The above slightly different axial elongation ratios and planar bond length variation ratios may suitably account for the slightly dissimilar axial g anisotropies Δg (≈0.351 and 0.339) and perpendicular g anisotropies δg (≈0.028 and 0.022) of the two centers, respectively.

[Research Progress of Supercontinuum Laser Spectroscopy in Biomedical Field].

Supercontinuum laser refers to the spectral broadening of an incident laser beam due to a series of nonlinear effects when the incident beam passes through a special light guide. With the development of ultrafast lasers and the photonic crystal fiber technology, the coherent and bright supercontinuum laser, generated with ultrashort pulses propagating in photonic crystal fibers, has become a kind of ideal white light source. Since supercontinuum lasers have been put into practice, their application domain is getting wider, especially for cells and bloods analysis in the biomedical field with fluorescence spectroscopy, flow cytometry, confocal microscopy, and optical coherence tomography as powerful analysis tools. Supercontinuum laser source has become one of the mail optical components in these scientific instruments that employ advanced technologies. In this paper, international research progress on supercontinuum laser sources was introduced in detail firstly, and then the development and application of supercontinuum laser spectroscopy technology in biomedical fields, such as microscopic imaging, flow cytometry instrument, fluorescence lifetime imaging microscopy, fluorescence resonance energy transfer, optical coherence tomography, and confocal microscopy was comprehensively elaborated. The requirements, schemes and research progress of supercontinuum laser spectroscopy technologies in the noncontact identification for blood products were also discussed in the paper, including studies on light fiber supercontinuum laser sources with spectra range from 400 to 2000nm, distinguishing species characteristic of bloods with supercontinuum laser spectroscopy, analyzing and establishing mathematical models based on meta databases of big data bloods spectra, determining the bloods species based on these models, and developing portable instruments for bloods spectra identification. Finally, the prospect of applications of supercontinuum laser spectroscopy in the biomedical field is discussed.

[Elemental Analysis of Rock with Remote Laser Induced Breakdown Spectroscopy].

As a kind of spectroscopic technique, the remote laser-induced breakdown spectroscopy (Remote LIBS) can qualitatively or quantitatively measure the elemental compositions of remote targets with high-power laser and focusing optical path. In this work, a Remote LIBS system was designed and established to probe the target from 2 to 10 meters. It is characterized with Cassegrain telescope structure and automatic focusing technique. Based on this system, a method to remotely retrieve the major elemental abundance of rocks is presented. With comparative experiment, the influences on spectral signal by pulse laser energy, acquisition delay time, integration time, accumulative pulse number are analyzed to find out the optimum parameters: the wavelength of laser is 1 064 nm, pulse energy is 120 mJ, delay time is 1.5 µs, integration time is 1 ms, and each spectrum data acquired with averaging 30 times detection. 48 pieces of rock specimens and 6 kinds of standard rock samples (shale, granite, andesite, basalt, gneiss and pegmatite) are selected for the experiment. As to the atomic spectra database, 8 characteristic spectral lines of the major elements (SiⅠ390.55 nm，AlⅠ394.40 nm，AlⅠ396.15 nm，CaⅡ396.85 nm，FeⅠ404.6 nm，SiⅠ500.60nm，MgⅠ518.36nm，NaⅠ589.59 nm) were extracted for analyses. Then a PLS model is constructed to quantitatively analyze the rock elements. 48 rock specimens were selected as the training sets to serve the model. The 6 standard samples were used to test the solved model. The testing results shows that the elemental abundance of Si and Al can be predicted accurately with average relative error of only 9.4% and 9.6% respectively.

[Plasma Mass Spectrometry of Sea Mountain Basalts in the Western Pacific and Its Geological Significance].

As a kind of spectroscopic technique, the remote laser-induced breakdown spectroscopy (Remote LIBS) can qualitatively or quantitatively measure the elemental compositions of remote targets with high-power laser and focusing optical path. In this work, a Remote LIBS system was designed and established to probe the target from 2 to 10 meters. It is characterized with Cassegrain telescope structure and automatic focusing technique. Based on this system, a method to remotely retrieve the major elemental abundance of rocks is presented. With comparative experiment, the influences on spectral signal by pulse laser energy, acquisition delay time, integration time, accumulative pulse number are analyzed to find out the optimum parameters: the wavelength of laser is 1 064 nm, pulse energy is 120 mJ, delay time is 1.5 µs, integration time is 1 ms, and each spectrum data acquired with averaging 30 times detection. 48 pieces of rock specimens and 6 kinds of standard rock samples (shale, granite, andesite, basalt, gneiss and pegmatite) are selected for the experiment. As to the atomic spectra database, 8 characteristic spectral lines of the major elements (SiⅠ390.55 nm，AlⅠ394.40 nm，AlⅠ396.15 nm, Ca II 396.85 nm，FeⅠ404.6 nm，SiⅠ500.60nm，MgⅠ518.36nm，NaⅠ589.59 nm) were extracted for analyses. Then a PLS model is constructed to quantitatively analyze the rock elements. 48 rock specimens were selected as the training sets to serve the model. The 6 standard samples were used to test the solved model. The testing results shows that the elemental abundance of Si and Al can be predicted accurately with average relative error of only 9.4% and 9.6% respectively.

[Identification of Animal Whole Blood Based on Near Infrared Transmission Spectroscopy].

The inspection and classification for blood products are important but complicated in import-export ports or inspection and quarantine departments. For the inspection of whole blood products, open sampling can cause pollution and virulence factors in bloods samples may even endanger inspectors. Thus non-contact classification and identification methods for whole bloods of animals are needed. Spectroscopic techniques adopted in the flowcytometry need sampling blood cells during the detection; therefore they can not meet the demand of non-contact identification and classification for whole bloods of animals. Infrared absorption spectroscopy is a technique that can be used to analyze the molecular structure and chemical bonds of detected samples under the condition of non-contact. To find a feasible spectroscopic approach of non-contact detection for the species variation in whole blood samples, a near infrared transmitted spectra (NITS, 4 497.669 - 7 506.4 cm(-1)) experiment of whole blood samples of three common animals including chickens, dogs and cats has been conducted. During the experiment, the spectroscopic resolution is 5 cm(-1), and each spectrogram is an average of 5 measured spectral data. Experimental results show that all samples have a sharp absorption peak between 5 184 and 5 215 cm(-1), and a gentle absorption peak near 7 000 cm(-1). Besides, the NITS curves of different samples of same animals are similar, and only have slight differences in the whole transmittance. A correlation coefficient (CC) is induced to distinguish the differences of the three animals' whole bloods in NITS curves, and the computed CCs between NITS curves of different samples of the same animals, are greater than 0.99, whereas CCs between NITS curves of the whole bloods of different animals are from 0.509 48 to 0.916 13. Among which CCs between NITS curves of the whole bloods of chickens and cats are from 0.857 23 to 0.912 44, CCs between NITS curves of the whole bloods of chickens and dogs are from 0.509 48 to 0.664 82, and CCs between NITS curves of the whole bloods of cats and dogs are from 0.872 75 to 0.916 13. The cat and the dog belong to the class of mammal, and the CCs between their whole bloods NITS curves are greater than those between chickens and cats, or chickens and dogs, which are hetero-class animals. Namely, the whole bloods NITS curves of the cat and the dog have higher similarity. These results of NITS provide a feasible method of non-contact identification of animal whole bloods.

[The Progress in Remote Laser-Induced Breakdown Spectroscopy].

As a kind of spectroscopic technique, the remote laser-induced breakdown spectroscopy (Remote LIBS) can measure elemental compositions of remote targets by using high-power lasers and focusing approaches. In this paper, three remote detection approaches (open path LIBS, fiber optic LIBS and compact probe fiber optic LIBS) and their system architectures are summarized and analyzed. Conventional open path LIBS, with high requirement of specifications of lasers, optical systems, spectrographs and detectors, has always been a research focus in remote testing field. Fiber optic LIBS has the advantages of simplification of optical focusing system and high collection efficiency of the plasma light. This paper reviews the progress in new techniques of LIBS, for instance Filament-LIBS techniques and LIBS combines with other spectral detection techniques, and emphatically analyzes their characteristics and advantages. These new techniques have greatly broadened the detection range of LIBS, enhanced material recognition ability of LIBS, and made a great contribution to expanding applications of remote LIBS. Latest development of applications of remote LIBS in fields of deep space exploration, hazardous material detection, pollution testing, metallurgical industries and heritage restoration is introduced in detail. With the development of laser techniques, spectral detection and calibration techniques, the detection range of remote LIBS has been expended, their application fields has been extended, and the detection precision and accuracy have been improved.

Detection and compensation of basis deviation in satellite-to-ground quantum communications.

Basis deviation is the reference-frame deviation between a sender and receiver caused by satellite motion in satellite-to-ground quantum communications. It increases the quantum-bit error ratio of the system and must be compensated for to guarantee reliable quantum communications. We present a new scheme for compensating for basis deviation that employs a BB84 decoding module to detect basis deviation and half-wave plate to provide compensation. Based on this detection scheme, we design a basis-deviation compensation approach and test its feasibility in a voyage experiment. Unlike other polarization-correction schemes, this compensation scheme is simple, convenient, and can be easily implemented in satellite-to-ground quantum communications without increased burden to the satellite.

[Study on impact of ethanol extracts from Sedum sarmentosum in inhibiting STAT-3 signaling and inducing apoptosis of human hepatocellular carcinoma cell line HepG2].

OBJECTIVE: To investigate the impact of ethanol extracts from Sedum sarmentosum (ESB) on STAT-3 signaling and its probable molecular mechanism in inducing apoptosis. METHOD: MTT assay was used to detect the impact of ESB on HepG2 cell proliferation. FITC-Annexin V-FITC /PI double-labeling were used to investigate the impact on hepatoma carcinoma cell apoptosis. Western blot analysis was used to test the expression levels of cell apoptosis-related proteins Caspase-3, Caspase-9, PARP, P-STAT-3 (Tyr705) , STAT-3, Bcl-2, Mcl-1. RESULT: ESB could notably inhibit proliferation of HepG2 cells, and induce HepG2 cell apoptosis, with the dose-dependent inhibitory effect. In addition, ESB could inhibit STAT-3 signaling, down-regulate Mcl-1 and Bcl-2 expressions, and induce degradation/activation of apoptosis-related proteins Caspase-3 and Caspase-9 and PARP degradation in a dose-dependent manner. CONCLUSION: ESB inhibits HepG2 cell proliferation and induces apoptosis by inhibiting STAT-3 signaling and Mcl-1 and Bcl-2 expressions.

[Analysis of distribution and contents of heavy metal pollution in fish body with laser-induced breaddown spectroscopy].

Environmental pollution can cause poisoning, disease and death of organisms, and the absorption and the accumulation of different biological tissues on pollutants are different. The absorption of heavy metal elements of various biological tissues on pollutants is an important biomedical research problem. In the present paper, a laser induced breakdown spectroscopy (LIBS) method was used to quantitatively analyze heavy metal elements in various tissues of some contaminated fish samples. Optimal experimental parameters were obtained in the LIBS experiments for these fish samples, calibration curves for plumbum and barium elements were fitted and the contents of heavy metal elements were determined with the external calibration approach. Experimental results showed that there was the heavy metal accumulation in fish liver mouth, and gills etc, however the heavy metal content in fish meat is very low. The proposed method can be used for the assessment studies of the influence of pollution on the organisms, and can be promoted in the biomedical fields.

[Study on physical deviation factors on laser induced breakdown spectroscopy measurement].

In order to eliminate the deviation between the measured LIBS spectral line and the standard LIBS spectral line, and improve the accuracy of elements measurement, a research of physical deviation factors in laser induced breakdown spectroscopy technology was proposed. Under the same experimental conditions, the relationship of ablated hole effect and spectral wavelength was tested, the Stark broadening data of Mg plasma laser induced breakdown spectroscopy with sampling time-delay from 1.00 to 3.00 micros was also studied, thus the physical deviation influences such as ablated hole effect and Stark broadening could be obtained while collecting the spectrum. The results and the method of the research and analysis can also be applied to other laser induced breakdown spectroscopy experiment system, which is of great significance to improve the accuracy of LIBS elements measuring and is also important to the research on the optimum sampling time-delay of LIBS.

Cross-reactivity between piperacillin-tazobactam and cefoperazone-sulbactam in drug-induced immune thrombocytopenia.

Beta-lactam antibiotics commonly cause immune thrombocytopenia. Cross-reactivity in patients with drug-induced immune thrombocytopenia has rarely been reported. In this study, we describe the case of a 79-year-old man who developed thrombocytopenia after receiving piperacillin-tazobactam for an acute exacerbation of chronic obstructive pulmonary disease, and he was successfully treated with meropenem and cefotiam. However, thrombocytopenia recurred after cefoperazone-sulbactam administration. This indicated that cross-reactivity of platelet-specific antibodies occurred between piperacillin-tazobactam and cefoperazone-sulbactam. However, the responsible drug structures remain unknown, requiring further investigation. Likewise, chemical structure similarities among beta-lactam antibiotics must be examined to determine the risk of immune thrombocytopenia in the clinical setting.

Olive oil authentication based on quantitative ß-carotene Raman spectra detection.

ß-carotene and oleic acids are important molecules to distinguish between extra olive oil (EVOO) and other oils. To identify adulteration which use common vegetable oils blended with ß-carotene to imitate EVOO, a non-invasive, lossless method is proved to be effective. The present work presents a laser confocal Raman technique for analyzing and comparing the differences of molecule between EVOO and SSO, which based on theoretical Raman spectra of ß-carotene, oleic acids and linoleic acids calculated by density functional theory (DFT). Chemometrics based on support vector regression (SVR) was used to realize quantitative analysis of ß-carotene in synthetic olive oils. Nine different volume ratios were prepared independently, and test set evaluation index of linear kernel of SVR as follow: RMSE 0.0653, R2 0.9868. The results show that laser confocal Raman technique, combined with theoretical Raman spectra based on DFT, could analyze composition of vegetable oil accurately, and identify low-cost imitation of olive oil.

Study on the Raman spectral characteristics of dynamic and static blood and its application in species identification.

This paper proposes a method to identify the blood of 4 poultry species (chicken, duck, goose and pigeon) based on Raman spectroscopy and its baseline. Samples were prepared by pretreatment methods of freezing, thawing, and dilution. The Raman spectra of dynamic blood and static blood were measured, respectively, and the spectral differences between the two research schemes were analyzed. The four species of poultry blood were identified based on the Raman spectroscopy and its baseline. The results show that the method can realize the identification of four species of poultry blood. In addition, the potential of Raman spectroscopy as a technique for determining carotenoids in blood has been clearly confirmed, which opens up the possibility to quickly determine whether poultry eats feed containing carotenoids without sample preparation.

Effect of chlorophyll fluorescence quenching on quantitative analysis of adulteration in extra virgin olive oil.

Extra virgin olive oil (EVOO) is both edible oil and health care product. Adulteration in high quality vegetable oil is a ubiquitous fraud, especially in the market of EVOO. Spectroscopy is an effective means to realize the rapid detection of adulteration in EVOO, but the accuracy of quantitative analysis is the short board of spectral detection. Traditional Raman spectroscopy is used to detect the adulteration of EVOO by analyzing the content of monounsaturated fatty acids. However, high oleic acid content is not unique to EVOO. Confocal Raman and Fluorescence Spectroscopy (CRFS) was employed to characterize EVOO along with potential adulterant oils based on their Oleic acid and photosensitive substances content. Statistical analysis of these Oleic acid and photosensitive substances using Multiple Linear Regression (MLR) allowed for a rapid approach to determine EVOO authenticity. The quantitative analysis model of adulteration in EVOO was established using this approach, and the RMSE was 0.0068, and the R-Squaredof external Prediction was 0.9996. In addition, Fluorescence quenching which interfered with the quantitative analysis of chlorophyll was found in the adulteration experiment of EVOO. Compared to traditional Raman methods, CRFS with MLR involves minimal sample preparation combined with fast analysis.

Spectral detection technology of vegetable oil: Spectral analysis of porphyrins and terpenoids.

In this paper, the existence of porphyrins and terpenoids in different vegetable oils and their spectral characterization techniques are reported. The classification of pure vegetable oils was realised by principal component analysis - support vector machine (PCA-SVM) model. The absorption spectra, Raman spectra, fluorescence spectra and supercontinuum spectra of 8 kinds of pure vegetable oils were studied, and the effects of oil types and processing technology on spectral differences were analysed. The results showed that the fingerprint information of 4 kinds of spectral techniques mainly came from chlorophyll and ß-carotene in vegetable oil. The extra virgin olive oil (EVOO) got by physical cold pressing technology had the most porphyrins and terpenoids content and the strongest activity. Therefore, the spectral characterization of porphyrins and terpenoids in vegetable oil can guide the regulation of the processing technology of vegetable oil and realise the qualitative and quantitative analysis of vegetable oil.

Rapid detection of Chinese-specific peony seed oil by using confocal Raman spectroscopy and chemometrics.

Peony seed oil (PSO) is a new woody nut oil which is unique to China. Its unsaturated fatty acids are over 90% and are rich in α - linolenic acid. Although the PSO industry is in its infancy, it is bound to become a top vegetable oil food material because of its own advantages. The potential high commercial profit of its adulteration with cheap vegetable oil will be an important factor hindering the healthy development of PSO industry. It is of great significance to study the adulteration of PSO for preventing large-scale adulteration. In this study, the qualitative and quantitative analysis of PSO was realised based on Raman spectroscopy combined with chemometrics analysis, and the fatty acid composition of PSO was analysed according to Raman characteristic peaks. The technology can be applied to routine analysis and quality control of PSO.

Dynamic confocal Raman spectroscopy of flowing blood in bionic blood vessel.

How to quickly and safely identify blood species has always been an urgent problem for scientists. Smear test method has the risk of blood contamination, and the blood itself may carry some unknown viruses or pathogens, which will bring health risks to the testing personnel. Therefore, in order to meet the urgent needs of rapid and safe detection of blood, a technology which can detect dynamic confocal Raman spectroscopy of flowing blood in bionic blood vessel was proposed. The blood, which was sealed in the bionic blood vessel, flowed through the focus gaze area of laser by the microfluidic pump, to detect the dynamic blood Raman spectrum. Human blood and cattle blood were selected as experimental objects, and the experiments were carried out under the same parameters. Combined with PCA-LDA (principal component analysis and linear discriminate analysis) classification model, the predictive classification of the two species without error recognition was realized. The hidden weak Raman signals were mined by derivative spectra, and the fundamental differences of Raman spectra of two species were compared. Then the biochemical information that caused the differences was also analyzed. The results show the method can meet the detection requirements of sealed blood, and the Raman spectra of flowing blood is more representative than those of static blood.

An online emission spectral tomography system with digital signal processor.

Emission spectral tomography (EST) has been adopted to test the three-dimensional distribution parameters of fluid fields, such as burning gas, flame and plasma etc. In most cases, emission spectral data received by the video cameras are enormous so that the emission spectral tomography calculation is often time-consuming. Hence, accelerating calculation becomes the chief factor that one must consider for the practical application of EST. To solve the problem, a hardware implementation method was proposed in this paper, which adopted a digital signal processor (DSP) DM642 in an emission spectral tomography test system. The EST algorithm was fulfilled in the DSP, then calculation results were transmitted to the main computer via the user datagram protocol. Compared with purely VC++ software implementations, this new approach can decrease the calculation time significantly.