Search

Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al2O3), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al2O3 was activated by oxalic acid. XRD, 27Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al2O3 decreased to 1029 °C for oxalic acid activated γ-Al2O3, and the α-fraction was 100% for activated γ-Al2O3 at 1300 °C. After oxalic acid activation, the diffraction peak intensity of γ-Al2O3 decreased significantly; the results of 27Al-MAS-NMR suggested that octahedral [AlO6] in γ-Al2O3 was easier than tetrahedral [AlO4] to be attacked by oxalic acid, and the formation of pentavalent [AlO5] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al2O3. The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al2O3 and extracted Al as three complexes of [Al(C2O4)]+, [Al(C2O4)2]- and [Al(C2O4)3]3-. Oxalic acid activated γ - Al2O3 with a lower phase transformation temperature has broad application prospects in the alumina industry.

The morphology, phase structure, saturation magnetization and coercive force of untreated, cryogenically treated and cryogenically treated and tempered cobalt samples has been investigated for studying the changes in microstructure, and magnetic properties. The result illustrates a noteworthy variation in the phase structure of cobalt after the cryogenic treatment. The saturation magnetization was unaffected, whereas an improvement in the coercive force has been detected. The XRD peak intensity of cryogenic cryogenically treated cobalt specimen reveals the cobalt phase transformation exhibiting a higher e-Co (hexagonal structure), which shoots up the coercive force. Additional tempering after cryogenic treatment has an insignificant effect on the analyzed properties.

The electrocatalytic oxidation of methanol on the Pt1Pd3 nanoparticles supported on rutile TiO2 in alkaline solution is investigated. The Pt1Pd3 nanoparticles are prepared by the chemical co-reduction of the precursors of Pt and Pd and then loaded on TiO2. The Pt1Pd3 nanoparticles with sizes of about 2–4 nm and a certain degree of aggregation are dispersed on TiO2. The position and shape of the methanol oxidation peak on Pt1Pd3/TiO2 are more similar to those on Pt/TiO2 than those on Pd/TiO2, while Pt1Pd3/TiO2 exhibits higher catalytic activity, e.g., a significantly higher peak intensity, than Pt1Pd3/C, Pt/TiO2 and Pd/TiO2. This indicates the advantage of TiO2 as a support material and the strong synergy between the Pt1Pd3 and TiO2 and between the Pt and Pd. Moreover, Pt1Pd3/TiO2 has a high tolerance for the poisoning caused by CO. Rutile TiO2 is shown to be suitable as a support material for the Pt1Pd3 to achieve enhanced catalytic activity and stability.

Brombuterol is a new emerging β-adrenergic agonist that has been used as an additive in animal feed to enhance the lean meat-to-fat ratio. Due to its potential harm to consumers, it is urgent to develop sensitive, simple and rapid analytical methods to monitor brombuterol residue. In this study, a competitive lateral flow immunochromatographic assay (FLIA) based on surface-enhanced Raman scattering (SERS) was developed for ultrasensitive quantitative determination of brombuterol in swine liver, pork and feed samples. Ag@Au core–shell bimetallic nanoparticles with the highest SERS enhancement were synthesized, characterized and used as the substrate for preparation of the immunoprobe AgMBA@Au–Ab, in which the Raman reporter mercaptobenzoic acid (MBA) was embedded between the core–shell layers and monoclonal antibodies against brombuterol were immobilized on the surfaces of nanoparticles. The presence of brombuterol was identified through a color change on testing lines. In addition, quantitative detection of brombuterol was achieved by measuring the characteristic Raman peak intensity of MBA in the immunoprobes captured by the coating antigen. The IC50 and limit of detection (LOD) of the SERS-based FLIA for brombuterol were 45 pg mL−1 and 0.11 pg mL−1, respectively. The recoveries of brombuterol from spiked samples were in the range of 87.27–100.16% with relative standard deviations of 1.29%–6.99% (n = 3). The proposed SERS-based LFIA was proven to be a feasible method for ultrasensitive and rapid detection of brombuterol and might be a platform for sensitive and rapid detection of a broad range of analytes in clinical, environmental and food analyses.

Tin-doped zinc oxide/tin oxide nanorod (Sn:ZnO/SnO2 NR) films were successfully synthesized using a solution immersion method by manipulating the pH concentration of the solutions to fabricate an ethanol gas sensor. Sn:ZnO/SnO2 NR films were prepared at constant Sn:ZnO solution pH (5.5), while the pH of the SnO2 solutions was varied between 4.5 and 6.5. In this study, the structural, morphological, and optical properties of Sn:ZnO/SnO2 NR films were investigated. The diameter and thickness of Sn:ZnO/SnO2 NR films were found to increase with the SnO2 pH. Interestingly, the Sn:ZnO/SnO2 NR sample that was prepared at SnO2 solution pH 5.5 showed the highest relative peak intensity along the c-axis plane orientation, which enhanced the sensor performance due to the shorter carrier pathway. In addition, this sample indicated a higher level of surface donor-related defects, which are favorable for sensing device performance. The samples were exposed to ethanol gas to measure their gas-sensing properties. Sn:ZnO/SnO2 NR films prepared at SnO2 solution pH 5.5 showed the highest sensing performance with short response/recovery times.

The purpose of this investigation was to evaluate the microstructure, high-temperature oxidation behaviour, and hardness of a seal coating under controlled exposures at 750 °C with different exposure times. The results reveal that the main phases in the coating are Ni, FeNi3, and hexagonal BN, with α-Al2O3 peaks appearing after 2-h oxidation. As the exposure time increases, the diffraction peak intensity of α-Al2O3 begins to decrease and Cr2O3 peaks appear after 200 h. After 1000 h, Cr2O3 becomes dominant with only small amounts of α-Al2O3 remaining. The high-temperature oxidation process of the coating includes three stages: the fast stage, transition stage, and slow stage. The oxidation rate is constant in each stage, and in the fast stage and slow stages with values of 7.59 × 10−4 and 8.37 × 10−5 mg2·cm−4·s−1, respectively. Initially, α-Al2O3 forms near the pores in the coating, followed by the formation of Cr2O3. As the exposure time increases, oxidation penetrates into the interior of the coating along phase boundaries to form island-shaped inner oxide layers with high concentrations of Cr, Ni, and Fe. Additionally, hardness increases with increasing oxide percentage.

Cationized cellulose filters with coating of oxidized carbonized cellulose (OCC) were successfully fabricated. The OCC-coated filter was demonstrated as a combined surface for adsorption of environ...

Background: Trans Fatty Acid (TFA) content in oil is an important quality parameter due to its adverse health effect. This study was aimed to examine the TFA content in the frying oil used by street food vendors in India for two traditional snack foods. Methods: Totally, 143 oil samples were collected at different frying times (0, 2, and 4 h) from five different vendors for Samosa and Jalebi. TFA levels of the oil samples were analyzed by Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATRFTIR). Statistical analyses were carried out using SPSS software version 23.0. Results: ATR-FTIR spectra exhibited an increase in peak intensity at 966 cm-1 with different frying time in both frying oil samples, indicating the formation of TFA. The TFA content in oils fried at 4 h was significantly higher than the ones at 0 and 2 intervals. It was found that 3 out of 74 (4%) Samosa fried oils and 12 out of 69 (17.4%) Jalebi fried oils were over the maximum allowed regulatory limit of TFA (5%). Jalebi fried oils had significantly higher TFA content than Samosa fried oils. Conclusion: The increase in frying time decreased the peroxide values and increased saturated fatty acids and TFA values of oils used for both food items. The local vendors and consumers should be educated by national authorities regarding health risk of TFA in street fried snacks.

In order to improve high hydrophilicity and low mechanical properties of biodegradable high-methoxy pectin (HMP) film, dialdehyde starch (DS) were introduced. In this study, different HMP/DS blended films were prepared by varying DS contents. It was observed from Infrared spectra that lower peak intensity of C=O stretching was detected after the incorporation of DS into HPM film. Moreover, moisture uptake of various HMP/DS blended films was found to be significantly lower than those of HMP film with the addition of low DS content. The improvement of mechanical properties was observed in various HPM/DS blended films. In addition, color parameters, swelling power, morphological and biodegradable properties of various HMP/DS blended films were also investigated.

We have studied a new approach to the analysis of carbon-containing materials by secondary ion mass spectrometry (SIMS), which allows determining the contents of carbon atoms in sp2 and sp3 hybridization states. According to this, the main SIMS parameter characterizing the atomic concentration N(sp3) is defined as the intensity ratio of C8/C7 secondary cluster ion peaks. Based on the results of SIMS analysis of several test compositions, a calibration dependence of N(sp3) versus C8/C7 peak intensity ratio has been obtained. The depth profiles of N(sp3) for diamond-like carbon (DLC) grown on diamond and silicon substrates were obtained, which showed (i) N(sp3) variation from 0.3 to 0.6 depending on the DLC growth regime and (ii) inhomogeneous distribution of N(sp3) in depth of the samples.

Based on the reversible covalent binding between borates and glycoproteins, we proposed a scheme that can specifically recognize and detect immunoglobulin G (IgG). The application of magnetic materials to enrich SERS probes can provide an enhanced signal and repeatability. The results showed that the prepared sandwich-like complex displayed high sensitivity and excellent selectivity for IgG. The Raman peak intensity showed a good linear relationship in the concentration range of 1 mg/mL - 1 ng/mL. The linear equation was y = 657.93x + 2963.9, R2 = 0.996. Parallel testing of this sandwich-like complex proved to have excellent repeatability. This method provided a new possibility for clinical non-immunity and the quantitative detection of IgG.

In recent years, the abuse of dexmedetomidine hydrochloride (DH) in various criminal cases has increased demand for the rapid and effective supervision and determination of DH. In this paper, based on the SERS method, DH in aqueous solution, urine and serum was effectively and sensitively detected. On the basis of density functional theory (DFT), the Raman peaks of DH were identified by systematic calculation. The SERS performance for the measurement of DH was compared between Ag colloid and paper-based substrate. It was found that Ag colloid together with KI as an aggregator was equipped with better SERS behavior and could thus be applied in the analysis of DH in biological samples. Furthermore, with simple pre-treatment, DH in urine and serum were successfully determined with detection limits down to 10 μg mL−1 and 12 μg mL−1, respectively. The linear relationships between the characteristic peak intensity and the concentration of DH in urine and serum were established and the recovery rates were calculated with low relative standard deviation (RSD). This fast, accurate and non-destructive SERS method lays a reliable foundation for rapid on-site detection of DH.

In this research work, an attempt has been undertaken to improve the structural, morphological and electrical properties of RF sputtered CCTO thin films with the incorporation of HfO2 as a buffer layer and Zn as an intermediate layer. RF sputtering technique was used to deposit all the films with the optimized sputtering parameters. XRD pattern of HfO2 buffered CCTO thin films have shown an increase in (220) peak intensity with the enhancement in buffer layer thickness from 2.5 nm to 20 nm. Field emission scanning electron microscope images depicted the formation of smooth surface morphology. In addition, improved electrical and interface properties are observed with the increase in buffer layer thickness. CCTO films, deposited on 20 nm of HfO2 buffer layer, have shown lower leakage current of 3.15 × 10−7 Amp. In addition, reduced Dit value of 5.3 × 1010 eV−1cm−2 has been observed for film with 20 nm buffer layers. Improved morphological and electrical properties in CCTO films are attributed to suppression of defect states due to the presence of HfO2 buffer layer. Furthermore, the effect of different position of Zn intermediate layer, sandwiched between two CCTO layers, was also investigated. The appearance of splitted (220) peak has confirmed the incorporation of Zn in CCTO lattice. The surface morphology was found to be strongly dependent upon the multilayer geometry. Improved dielectric constant of 1078 at 100 kHz frequency is observed for the film configuration of 40-10-60, in which the Zn layer is situated towards the middle position.

A surface-enhanced Raman scattering (SERS)–based immunoassay with gold nanostars (GNSs) is utilized for determination of the subarachnoid hemorrhage (SAH) biomarker glial fibrillary acidic protein (GFAP) at very low concentration levels, which allows for early diagnosis and guides clinical decision-making to treat SAH-induced complications. The Raman reporter 5,5′-dithiobis-2-nitrobenzoic acid (DTNB) modified on GNSs was selected as the SERS tags. The SERS immunoassay was assembled by SERS tag and GFAP probe-immobilized ITO substrate. Therefore, the level of GFAP can be detected by monitoring the characteristic Raman peak intensity of GFAP-conjugated GNSs at 1332 cm−1 with a very low detection limit. Under optimized conditions, the assay can work in the GFAP concentration range from 1 pg⋅mL−1 to 1 μg⋅mL−1, with a detection limit as low as 0.54 fg⋅mL−1. The performance of the SERS immunoassay proven by the detection of GFAP is equivalent to that of the conventional enzyme-linked immunosorbent assay (ELISA). Scheme 1. Schematic illustration of GNSs SERS immunoassay for ultrasensitive dynamic change detection of GFAP. (SAH: Subarachnoid hemorrhage, SCF: Cerebrospinal fluid; GNSs: gold nanostars; SERS: surface-enhanced Raman scattering; GFAP: glial fibrillary acidic protein)

A volatile organic compounds (VOC) gas monitor was developed using an ion mobility spectrometer (IMS). It was designed for real-time monitoring in work environments, where gas chromatography/mass spectrometry (GC/MS) does not perform well. To evaluate the identification capability, response time, and quantitative accuracy of this device, experiments were conducted using methyl ethyl ketone. This is widely used in many factories, and its short-term exposure limit (STEL) has been set by the American Conference of Governmental Industrial Hygienists. Because the ionizable amount of methyl ethyl ketone has already been exceeded in STEL value of 300 ppm which belongs to the measurement range of interest in this study, this study estimated the peak shift amount rather than the peak intensity. Calibration curves with high accuracy were obtained in a range including 300 ppm which is the STEL of methyl ethyl ketone. The results of the experiment suggest that the device can be used for monitoring chemical substances in a work environment.

Studying aging is important to further understand the molecular mechanisms underlying this physiological process and, ideally, to identify a panel of aging biomarkers. Animals, in particular mice, are often used in aging studies, since they mimic important features of human aging, age quickly, and are easy to manipulate. The present work describes the use of Fourier Transform Infrared (FTIR) spectroscopy to identify an age-related spectroscopic profile of the cardiac and skeletal muscle tissues of C57BL/6J female mice. We acquired ATR-FTIR spectra of cardiac and skeletal muscle at four different ages: 6, 12, 17 and 24 months (10 samples at each age) and analyzed the data using multivariate statistical tools (PCA and PLS) and peak intensity analyses. The results suggest deep changes in protein secondary structure in 24-month-old mice compared to both tissues in 6-month-old mice. Oligomeric structures decreased with age in both tissues, while intermolecular β-sheet structures increased with aging in cardiac muscle but not in skeletal muscle. Despite FTIR spectroscopy being unable to identify the proteins responsible for these conformational changes, this study gives insights into the potential of FTIR to monitor the aging process and identify an age-specific spectroscopic signature.

We developed a new surface-enhanced Raman scattering (SERS)-based aptasensor platform capable of quantifying severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) lysates with a high sensitivity. In this study, a spike protein deoxyribonucleic acid (DNA) aptamer was used as a receptor, and a self-grown Au nanopopcorn surface was used as a SERS detection substrate for the sensible detection of SARS-CoV-2. A quantitative analysis of the SARS-CoV-2 lysate was performed by monitoring the change in the SERS peak intensity caused by the new binding between the aptamer DNA released from the Au nanopopcorn surface and the spike protein in the SARS-CoV-2 virion. This technique enables detecting SARS-CoV-2 with a limit of detection (LoD) of less than 10 PFU/mL within 15 min. The results of this study demonstrate the possibility of a clinical application that can dramatically improve the detection limit and accuracy of the currently commercialized SARS-CoV-2 immunodiagnostic kit.

Active capture and ultrasensitive SERS-based detection of hexachlorocyclohexane (HCH) has been a challenging task. A novel strategy based on 4-mercaptophenylboronic acid (4-MPBA) surface modification on Au nanosheets-built hollow sub-microcubes (ANHCs) was proposed to capture HCH pesticides effectively via Suzuki cross coupling reaction. The ANHCs structure composed of numerous intertwined nanosheets was firstly prepared by Au nanocrystals heteroepitaxial growth on AgCl cubes. Then, the 4-MPBA molecules were selected to modify on the surface of ANHCs for SERS-based detection of HCH. The SERS results proved that active capture and ultrasensitive detection of HCH could be implemented, and the limit of detection is 0.3 ppb. Besides, 4-MPBA modified substrate show high reproducibility and sensitivity than unmodified one. Moreover, the characteristic peak intensity ratio IHCH/I4-MPBA presents a good linear relationship with the logarithm of a certain concentrations, and achieve SERS-based quantitative detection of HCH. In addition, this strategy has been successfully used for the detection and differentiation of mixed HCH isomers in water samples. The surface modification strategy on high performance SERS substrate provides a good route for the highly ultrasensitive detection and active capture of HCH, and paves a way for the detection of organochlorine pesticide residues in water samples.

1H and 2H NMR spectra of 4 natural and synthetic nicotine samples were collected in a non-quantitative way and site-specific 2H/1H peak intensity ratio (SPIR) was calculated for 12 distinct sites of nicotine. Experimental results illustrated that the SPIRs at sites of 6, 2′, and 5′β of natural nicotine were significantly different from those of the synthetic nicotine, and could be used for nicotine authentication as the measured SPIRs were indicative of the site-specific natural isotope fractionation. We demonstrated that this method could be applied to detect adulteration of natural nicotine with as low as 20% synthetic nicotine, without the need to measure the site-specific δD values, which usually required time-consuming quantitative 2H NMR and additional IRMS for the overall 2H/1H isotopic ratio determination. The distinguishable 2H/1H SPIRs of nicotine, which can be quickly measured by NMR in non-quantitative way, can serve as an attractive alternative tool for tobacco authentication.

The potential of high-performance thin-layer chromatographic (HPTLC) fingerprinting in identifying differences in sandalwood essential oils from 5 sandalwood species, namely, Santalum album, Santalum spicatum, Santalum austrocaledonicum, Santalum paniculatum, Santalum lanceolatum, and a natural substitute for sandalwood, Osyris lanceolata, was explored. Variation was observed in the profile of bands (RF values and color) and peak intensity profiles displayed by the essential oils across and within the essential oils studied with some bands being unique to the individual species. The potential of HPTLC fingerprinting as a quality control tool in authenticating sandalwood oils in the sandalwood industry was demonstrated in the present study.

Based on a SERS study, the plasmon-assisted coupling reaction of p-iodoaniline (PIAN) to p,p′-diiodoazobenzene was investigated. This model plasmon-assisted reaction exhibits an outstanding SERS performance with the limit of detection as low as 10–13 M. Under low concentrations, the control of the cis–trans isomerization of p,p′-diiodoazobenzene was achieved by characterizing the Raman peak intensity at 1432 cm–1 of the coupling reaction catalytic product. We present the regulation strategy for the isomerization of azobenzene derivatives enabled here, through the controlled adjustment of reactant concentration, and expand the application of SERS technique.

Blue-shifting H-bonded complexes between CHCl3 and CH/D3CN have been identified by Fourier transform infrared spectroscopy in the gas phase at room temperature. The change in FTIR peak intensity of the mixture of the two components as a function of temperature and composition provides the basis for identification of the H-bonded band in the infrared spectrum. On complex formation with CH3CN and CD3CN, the C−H stretching frequency of CHCl3 shifts to the blue by +8.7 and +8.6 cm−1, respectively. The molecular electrostatic potential calculation at the MP2/6-311++G** level has been used to arrive at the geometry of the complex. It has been reported in the literature that CHCl3 and CH/D3CN form red-shifting H-bonded complex in Ar matrix. The red shifting has been verified by doing ab initio calculations in the presence of Ar atoms, which has been attributed to the matrix effect at low temperature. The interaction of Ar with CH3CN makes the CH3CN more basic and as a result it becomes better hydrogen bond accep...

Given the growing interest in the application of Raman spectroscopy for quantitative purposes in solid pharmaceutical preparations, a revision of the effect of particle size on Raman spectra of compacted samples is presented. For this purpose, a set of tablets of potassium hydrogen phthalate (KHP) of different particle size were prepared. KHP was used because of its purity and stability, which allow to consider that samples will not be altered during measurements; but also because of its chemical structure (aromatic ring and carboxylic groups), that are present in many active pharmaceutical ingredients (API). The latter makes possible to consider KHP as a model pseudo-API. As KHP tablets only contain a pure compound, the mapping strategy that was considered for measuring our samples will not be affected by subsampling issues. The spectra variance can be attributed to the intrinsically reproducibility in recording the spectra (which mainly depends on the instrument set-up) and the site-to-site differences in elastic scattering properties. Two different instrumental optics have been studied: a macro-Raman system and a Raman microscope (500 μm and 50 μm laser spot size, respectively). The effect of the spectra preprocessing is also evaluated. The overall results demonstrate raw Raman intensity increases with particle size up to a value that depends on tablet width and that the applied spectral preprocessing (baseline correction and a unit vector normalization), reduces the differences in Raman intensities due to the particle size, but does not completely eliminate it for the lower particle sizes (< 20 μm). For tablets containing particles with predefined sizes, it corrects the mapping site-to-site differences in elastic scattering.

Nanodiamonds (NDs) have been synthesized by using microplasma facility. Ethanol is chosen as a Carbon precursor. A mixture of Ethanol and Argon has been dissociated in microplasma to fabricate NDs. In order to quench, etch and stabilize the NDs, Hydrogen has been used as a stabilizing agent. The motivation behind this project is to find an effective root for the introduction of Hydrogen into microplasma. The experiments are performed by introducing the Hydrogen either directly or indirectly into the microplasma. The results obtained from Raman, TEM and XRD confirmed that the highest quality (in terms of smallest size and near stress free) diamonds have been obtained in the case of indirect dilution. The decreased PL peak intensity with indirect dilution indicates the decreased defect density in the diamond. It is possible to produce and control the defect center only by controlling the Hydrogen introduction way in to the microplasma. The indirect dilution decreases the amount of Hydrogen bonded to trans-polyacetylene and enhances the Hydrogen termination to the surface of diamond grains.

The tentative identification of bioactive compounds in the extract of Vernonia amygdalina leaf was carried out using positive ionization of Liquid chromatography-mass spectrometry quadrupole time of flight (LC-Q-TOF/MS). The positive ionization is associated with the presence of saponins, flavonoids, alkaloids, terpenoids, and glycosides. Tentative assignments of the secondary metabolites were performed by comparing the MS fragmentation patterns with Waters® UNIFY library which allows positive identification of the compounds based on the spectral match. All the metabolites compounds were estimated and presented in a BPI (Base peak intensity) plot. These data are the unpublished supplementary materials related to “Ethanolic extraction of bioactive compounds from V. amygdalina leaf using response surface methodology as an optimization tool” (Alara et al., 2018).

Antibiotic resistant bacteria pose an increasing threat to global public health, and it is essential that effective detection methods for identifying these organisms. This study assesses the ability of three different analytical approaches that were developed using surface-enhanced Raman spectroscopy (SERS) to differentiate between antibiotic sensitive and resistant bacteria based on their responses to ampicillin exposure, using Escherichia coli O157:H7 as a model bacterium. The approaches tested in this study included a conventional SERS approach of mixing a droplet of bacterial culture with gold nanoparticles, extracellular matrix analysis, and in situ mapping of bacterial cells on a filter membrane. All three of the SERS techniques were able to differentiate between the sensitive and resistant bacterial strains based on peak intensity changes associated with compounds released by the bacteria in response to antibiotic exposure, with extracellular matrix analysis and filter mapping both observed to be more effective than the conventional approach. However, there were significant differences between the spectra obtained from the different techniques and the potential advantages and disadvantages of each approach should be considered when used in the future. This study shows that SERS can be an effective technique for rapid and efficient assessment of ampicillin sensitivity in E. coli, and more work should be done to explore these analytical approaches with other types of bacterial samples.

Background The antitumor effect of a drug is considered to be associated with a decrease in tumor blood flow. Aims We investigated whether the efficacy of lenvatinib (LEN) could be accurately assessed by measuring blood flow in hepatocellular carcinoma (HCC) during early treatment stages. Methods and results Blood flow changes and treatment results of 19 patients who underwent contrast-enhanced ultrasound (CEUS), before and after LEN administration, in Kurume University Hospital from July 2018 to June 2020 were examined. Blood flow was evaluated after the intravenous administration of perflubutane (0.015 ml/kg). The vascular phase was photographed and used as RAW data, and time-intensity curve analysis was used to obtain the region of interest (ROI) on the entire tumor nodule and quantify tumor blood flow. The evaluation was performed before and 1 and 4 weeks after LEN administration. Mean ± standard deviation (SD) values of the brightness of blood flow in the background liver before and 1 and 4 weeks after LEN administration were 2.84 × 10-4 ± 2.94 × 10-4 , 3.07 × 10-4 ± 3.79 × 10-4 , and 10.0 × 10-4 ± 20.8 × 10-4 dB, respectively. Blood flow in the background liver did not significantly decrease at 1 and 4 weeks compared with that before treatment. Mean ± SD values of the brightness of blood flow in HCC before and 1 and 4 weeks after administration were 3.49 × 10-3 ± 4.58 × 10-3 , 1.16 × 10-3 ± 1.57 × 10-3 , and 6.39 × 10-3 ± 22.8 × 10-3 dB, respectively. Blood flow in HCC after 1 week was significantly lower than that before administration (p = .0192). The therapeutic effects were significantly higher in the group with ≥50% blood flow reduction in HCC at 1 week after administration (p = .0038) and the group with reduced blood flow in HCC at 4 weeks after administration (p = .0051) than those before administration. Conclusion Early blood flow evaluation by CEUS may be useful in predicting the therapeutic effect of LEN for unresectable advanced HCC.

Rationale Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) is a preferred technique for analyzing complex organic mixtures. Currently, there is no consensus normalization approach, nor an objective method for selecting one, for quantitative analyses of FT-ICR-MS data. We investigate a method to evaluate and score the amount of bias various normalization approaches introduce into the data. Methods We evaluate the ability of the Statistical Procedure for the Analysis of Normalization Strategies (SPANS) to guide the selection of appropriate normalization approaches for two different FT-ICR-MS data sets. Furthermore, we test the robustness of SPANS results to changes in SPANS parameter values and assess the impact of using various normalization approaches on downstream statistical analyses. Results The normalization approach identified by SPANS differed for the two data sets. Normalization methods impacted the statistical significance of peaks differently, underscoring the importance of carefully evaluating potential methods. More consistent SPANS scores resulted when at least 120 significant peaks are used, where larger sets of peaks were obtained by increasing the p-value threshold. Interestingly, we show that total sum scaling and highest peak normalization, used in previous studies, underperformed relative to SPANS-recommended normalization approaches. Conclusions Although there is no single, best normalization method for all data sets, SPANS provides a mechanism to identify an appropriate normalization method for analyzing FT-ICR-MS data quantitatively. The number of peaks used in the background distributions of SPANS contributes more significantly to the reproducibility of results than the p-value thresholds used to obtain those peaks.

Spontaneous Raman spectroscopy, which senses changes in cellular contents of reduced cytochrome c, could be a powerful tool for label-free evaluation of ischemic hearts. However, undetermined is whether it is applicable to evaluation of myocardial viability in ischemic hearts. To address this issue, we investigated sequential changes in Raman spectra of the subepicardial myocardium in the Langendorff-perfused rat heart before and during ligation of the left coronary artery and its subsequent release and re-ligation. Under 532-nm wavelength excitation, the Raman peak intensity of reduced cytochrome c at 747 cm-1 increased quickly after the coronary ligation, and reached a quasi-steady state within 30 min. Subsequent reperfusion of the heart after a short-term (30-min) ligation that simulates reversible conditions resulted in quick recovery of the peak intensity to the baseline. Further re-ligation resulted in resurgence of the peak intensity to nearly the identical value to the first ischemia value. In contrast, reperfusion after prolonged (120-min) ligation that assumes irreversible states resulted in incomplete recovery of the peak intensity, and re-ligation resulted in inadequate resurgence. Electron microscopic observations confirmed the spectral findings. Together, the Raman spectroscopic measurement for cytochrome c could be applicable to evaluation of viability of the ischemic myocardium without labeling.

Asian lacquer is a special polymeric material tapped from lacquer trees. The tree&rsquo, s sap is a complex mixture of compounds, such as catechol lipids, polysaccharides, glycoproteins, enzymes, and water. Researchers have not yet quantitatively analyzed blended lacquers. We evaluated the compositions of Japanese and Vietnamese lacquers, and blends of the two, using time-of-flight secondary ion mass spectrometry (ToF&ndash, SIMS), pyrolysis&ndash, gas chromatography/mass spectrometry (Py&ndash, GC/MS), and high-performance liquid chromatography (HPLC). ToF&ndash, SIMS provided quantitative results for blended lacquers, provided structural information on polymeric lacquer films, and indicated the presence of dimers of urushiol&ndash, urushiol, urushiol&ndash, laccol, and laccol&ndash, laccol derivatives. We used Py&ndash, GC/MS and HPLC to obtain linear calibration curves. The specific peak intensity was a linear function of the ratio of Japanese to Vietnamese lacquer in the blends. For an unknown mixture, all three techniques gave essentially the same results. These quantitative methods will be useful for improving the physical properties of polymeric lacquer films, and evaluating the lacquer quality in industry and historic conservation.

We report on the investigation of the biological effects of high-power pulsed broadband terahertz (THz) radiation on human skin fibroblasts. Cells were exposed to THz pulses with peak intensity ~30 GW/cm2 and electrical field strength ~3.5 MV/cm for 1.5 hours. Phosphorylation of H2AX (γH2AX foci) can be caused by different reasons including DNA double stand breaks, heat induction and can be related to chromosomes stability. However, the γH2AX foci seem to be a proper marker for detection of the effect of intense terahertz pulses on cells. The kinetics of phosphorylated histone H2AX foci post terahertz radiation exposure is analyzed. We found that the number of phosphorylated H2AX foci in human skin fibroblasts remained almost unchanged within 24 hours following terahertz exposure.

This paper describes a method based on surface enhanced Raman spectroscopy (SERS) technology for rapid detection of dezocine in urine and serum. Firstly, an Ag colloid substrate was prepared and characterized. Then the Raman characteristic peaks of dezocine were assigned from both theoretical and experimental aspects. Finally, the Raman peak at 661 cm-1 was selected as its characteristic peak to perform SERS detection on dezocine in urine and serum, and the detection limits of dezocine in urine and serum were determined. The relationships between the characteristic peak intensity and the concentration of dezocine in urine and serum were fitted and the recovery rates were calculated. This rapid, accurate and non-destructive method establishes a good foundation for rapid on-site detection of dezocine in biological samples.

In this paper an algorithm to detect the optic disc (OD) automatically is described. The proposed method is based on the circular brightness of the OD and its correlation coefficient. At first the peak intensity points are taken, a mask is generated for the given image which gives the circular bright regions of the image. To locate the OD accurately, a pattern is generated which is similar to the OD. By correlating the retinal image with the pattern generated, the maximum correlation of the pattern with the OD is obtained. On locating the coordinates of maximum correlation, the exact location of the OD is detected. The proposed algorithm has been tested with DRIVE database images and an average OD detection accuracy of 95% was obtained for healthy and pathological retinas respectively.

Denture teeth are used for removable prostheses and implantsupportive restorations. The purpose of this study was to analyze the surface of artificial teeth following exposure to different liquids. Mechanical wear and the cleaning of artificial teeth were also investigated. Two groups of resin teeth were used, original surface (Group A) and surface abrasion/wear (Group B). The teeth were exposed for 24 h to water (control), cola (Group 1), coffee (Group 2), tea (Group 3), chlorhexidine (Group 4), and red wine (Group 5). Baseline measurements of liquids were taken. An xray fluorescence spectrometric analysis was performed. Data were evaluated using semiquantitative descriptive analysis. The data showed approximate increases of peak intensity for Group A12fold Fe, 2fold Ni, 2.2fold Zn, for Groups A2 and A3 less than 1.5fold Fe, Ni, and Zn. Group B yielded similar results, however, the increases in Fe, Ni, and Zn were significantly higher in Groups 1 and 2 (ranged 24fold increases in intensity). Group B3 showed little increase in Fe, Ni, and Zn. Groups A4 and A5 showed intensity increases for Zn. Groups A1&ndash, A5 showed reductions in intensity following 30 s of cleaning. A pronounced accumulation of iron, nickel, and zinc was found after exposure to liquids, especially when artificial teeth were worn down. Peak intensities were reduced following 30 s of brushing.

Spectral analysis using chemometrics is extensively used for quantitative chemical analysis in a mixture, but it works powerfully only when the peak intensity is solely proportional to the quantity of chemical components. In this sense, thin films on a solid substrate are not suitable for chemometric analysis, because the molecular orientation also influences the peak intensity via the surface selection rules. In the present study, this long-term analytical issue has readily been overcome by using p-polarized multiple-angle incidence resolution spectrometry (pMAIRS), which has a characteristic that the in-plane (IP) and out-of-plane (OP) vibrational spectra of a thin-film sample are obtained simultaneously in a common ordinate scale. Thanks to this unique power of pMAIRS, the average of the IP and OP spectra annihilates optical anisotropy, yielding an orientation-free spectrum, which enables us to perform the simultaneous quantitative analysis of both quantity change and molecular orientation of the constituents in a thin film. Now, we are ready to examine chemical reactions quantitatively in a thin film.

In order to investigate the effect of deep burial metamorphism on the wettability of coal during deep burial metamorphism, a superficial coal sample (∼90 m) and a deep coal sample (∼490 m) collected from two main mining seams were selected to simulate the deep burial metamorphism process. The wettability of two coal samples during deep burial metamorphism was investigated by X-ray photoelectron spectroscopy (XPS), FTIR, zeta potential, and contact angle measurements. Besides, comprehensive DLVO interaction analyses between two coal samples from different mining depths were carried out through the zeta potentials measurements under different pH values. The XPS results demonstrate that the content of surface oxygen atom and oxygen-containing functional group for superficial coal tends to be higher than that of deep coal. The FTIR results indicate that the peak intensity of oxygen-containing functional groups for the superficial is higher than that of deep coal, implying the stronger surface hydrophobicity of deep coal compared to superficial coal. The contact angle of superficial coal is lower than that of deep coal. The zeta potential and DLVO theory analyses of superficial particles and deep coal particles indicate that deep burial metamorphism process might be favorable for bubble-particle collision and attachment, while might be unfavorable for the wetting process oppositely. Based on the surface chemistry characterization and theory analyses, this study is expected to give a theoretical insight into the efficient processing or dedusting process of coals experiencing different deep burial metamorphism processes in the future.

Gallium doped ZnO nanorods exhibiting good PL performance were grown via a solution method. The as-grown, Ga-doped, and undoped ZnO nanorods displayed a broad yellow–orange emission and a UV emission peak, respectively. By applying an annealing process, the broad yellow–orange emission almost disappeared and the UV emission increased significantly (for ZnO:Ga (1.2%) peak intensity ratio ≅ 56). With Ga doping, the UV emission peak shifted from 3.27 eV to 3.28 eV. Also, experimental results revealed that a sample doped with Ga at 1.2% by mass exhibited a stronger PL intensity than either the undoped ZnO (higher by 57% acc. to peak intensities) sample or a ZnO sample doped with Ga at 2% (higher by 88% acc. to peak intensities). Both doped and undoped samples were also tested as alpha particle scintillators , and similarly the ZnO:Ga (1.2%) nanorods were found to have higher scintillation response than ZnO:Ga (2%) or undoped ZnO.

Bacterial pathogens such as Yersinia pestis, Francisella tularensis, and Bacillus anthracis are classified into the highest rank of potential bioterrorism agents. Colorimetric lateral flow assay (LFA) strips are commercially available but these conventional strips have drawbacks in terms of low sensitivity and limit of quantitative analysis. Therefore, there is an urgent need for a new sensing platform to detect these pathogens in the early contamination stage. In this study, a novel surface-enhanced Raman scattering (SERS)-based LFA strip was developed for sensitive detection of bacterial pathogens. Target-specific SERS nanotags (Raman reporter-labeled gold nanoparticles) were used as an alternative to the gold nanoparticles in conventional LFA strips. Using these SERS nanotags the presence of bacteria could be identified through a simple color change in the test line. Additionally, highly sensitive and accurate quantitative analysis could be performed by monitoring the characteristic Raman peak intensity of SERS nanotags that were captured in the test line. This highly sensitive method required a short assay time (15 min) and a tiny volume of pathogen sample (40 μL). We believe that the proposed SERS-based LFA technique has great potential as a valuable tool in the early detection of specific bacterial pathogens in the field due to its excellent analytical sensitivity.

The chemical quantitative analysis at trace level has been widely explored by means of various techniques. While it still remains challenging to achieve ultrasensitive but facile, rapid, and inexpensive detection methods. In this paper, the possibility of employing surface-enhanced Raman scattering technique on a portable Raman system for rapid and accurate quantitative analysis of target chemicals in unknown systems was investigated. This detection approach contains 3 steps: (1) adding target chemicals with different amount to the initial unknown solution, leading to new solutions with target molecules of various concentrations; (2) Obtaining different samples' SERS spectra and capturing featured SERS peaks whose intensity grew up with the addition of target chemicals; (3) examining the relationship between featured peak intensity increment after adding target chemicals and its corresponding addition amount, and thus we could perform quantitative analysis of the chemical in an unknown solution and obtain its initial concentration. The validity of this method was systematically demonstrated by estimating the concentrations of 2-Naphthalenethiol (2-NaT) and 4-Mercaptopyridine (4-MPY) both in their single-component solutions and binary solutions, respectively. Predictions are close to their real values. Furthermore, we successfully predicted the concentrations of malachite green (MG) in fish water and benzidine in ground water. This study clearly demonstrates an accurate and facile approach to calculate the concentration of target chemicals in unknown systems, which fully exploit the potential of SERS quantitative analysis.

Despite the fact that soy sauce has been one of the most popular seasonings in Eastern Asia, rapid and holistic methods for its authentication and discrimination are still lacking. This research is sought to develop a novel method for rapid discrimination and amino nitrogen quantitative evaluation of different qualities of soy sauces (Chinese traditional fermentation soy sauce (CTFSS), Japanese traditional fermentation soy sauce (JTFSS), high-salt liquid-state fermentation soy sauce (HLFSS), and low-salt solid-state fermentation soy sauce (LSFSS)) based on tri-step infrared spectroscopy (IR) and partial least squares (PLS). Global nutrition fingerprints (saccharides, proteins, amino acids, and other compositions) of each quality soy sauce at the three levels of enhanced spectral resolution and nutrition profile variations among different soy sauces are synthetically interpreted with fast evaluation of their relative contents based on spectral peak intensity. Complementarily, electronic sensory combined with SPME-GC-MS distinguishes four species of soy sauces effective in smell with 90 discrimination indexes. Specifically, FT-IR peak intensity at about 1409 cm−1 (C–N band) exhibits regular enhancement with the increasing concentration of amino acid nitrogen. Thus, a quantitative prediction model based on IR spectra is established by PLS (R2, 0.9956; RMSEC, 0.233). It has been demonstrated that the developed method is applicable for rapid (5 min) discrimination and quantitative analysis of amino acid nitrogen in soy sauce.

The paper demonstrates the possibility of measuring the carbon dioxide (CO2) concentration in atmospheric air using Raman spectroscopy. Three methods have been studied for deriving the CO2 concentration from the Raman spectra (the peak intensity ratio, the integrated intensity ratio, the contour fit method). The best results were obtained when the contour fit method is applied for Raman spectra processing. In this case the deviations from reference mixtures of known concentration were below 3 ppm. Methods for improving the sensitivity of the Raman gas analysis method are proposed and the possibility for using this technique for the simultaneous determination of the concentrations of significant amount of greenhouse gases in air with single device is discussed.

The effects of hot-strip coiling temperature on Ti(C,N) precipitation, texture and hydrogen permeation behavior in DC06EK enamel steel were investigated by TEM, EBSD test and electrochemical hydrogen permeation experiment. It was found that the Ti(C,N) particles in hot-strip coarsened with increasing coiling temperature, whereas after cold-rolling and annealing, the size difference of Ti(C,N) particles was lessened. The hot-strip coiling temperature has a significant impact on the recrystallized texture in the subsequent cold-rolled and annealed sheet. Hot-strip using high temperature (700 °C) coiling leads to strong {111} recrystallized texture in annealed sheet, with peak intensity 9.2. On the contrary, in annealed sheets using hot-strip coiling at 650 °C, their {111} recrystallized textures were weaker, which was also reflected in their rm values. Even though the hydrogen diffusion coefficient is slightly lower (7.76×10-5 mm2/s) in annealed sheet using low temperature coiling (600 °C), appropriately higher coiling temperature is more suitable for DC06EK enamel steel combining both good drawability and fish-scale resistance.

The CLRS detection characteristics of acetone dissolved in transformer oil were analyzed. Raman spectral peak at 780 cm–1 was used as the characteristic spectral peak for qualitative and quantitative analyses. The effect of the detection depth and the temperature was investigated in order to obtain good Raman signals. The optimal detection depth and temperature were set as 3 mm and room temperature. A quantitative model relation between concentration and the Raman peak intensity ratio I780/I893 was constructed via the least-squares method. The results demonstrated that CLRS can quantitatively detect the concentration of acetone in transformer oil and CLRS has potential as a useful alternative for accelerating the in-situ analysis of the concentration of acetone in transformer oil.

Nanostructures in the PAN-based carbon fibres were investigated by means of the Raman spectroscopy which was performed using a series of different excitation wavelengths. UV-Raman measurements showed the predominance of sp2 carbon for the carbon fibres with Young’s moduli ranging from 55 to 440 GPa. The excitation wavelength dependence of the spectral line shape implied the presence of the graphitic (sp2 carbon layers) as well as the amorphous carbon-like component (sp2 carbon clusters) in these fibres. An analytical modelbased upon the Tuinstra-Koenig relation and the rule-of-mixtures concept was proposed to account for the observed behaviour of the peak intensity ratio ID/IG. It was suggested that the carbonisation heat treatment led to the sp2 carbon layers extending rapidly throughout the nanostructure, resulting in the complete loss of the sp2 carbon clusters for the higher-modulus carbon fibres. These new findings together with the proposed analytical model are believed to be essential keys towards the development of new generation carbon fibres.

The X-ray fluorescence technique using peak intensity ratios of trace elements is one of the faster, less expensive and less invasive methods for obsidian sourcing. Moreover, XRF peak intensity ratios are particularly useful when the artifact is slightly altered, particularly affecting the alkali cations, or when its surfaces are covered with a fine film of carbonate deposits formed while the sample was buried. The limitation of this technique results from the dimensions of the obsidian samples: very small obsidian samples, nowadays about 1 cm in size, are difficult to measure given the very few X-rays emitted by their surface. An aluminium holder closed with a very thin Mylar© polyester film was prepared and the specimen, positioned at the centre of the surface of the Mylar film, was placed in the XRF spectrometer. The use of recent technology XRF apparatus equipped with a 4 kW Rh anode X-ray tube coupled with an accurate measurement of refined X-ray characteristic lines, that exclude the X-ray background contribution, of five trace elements (Rb, Sr, Y, Zr, Nb), made it possible to determine the source geological outcrop of archaeological obsidian samples as little as 7 mm and as light as 40 mg. A database of peak intensity ratios, background and interference free, of five trace elements was produced for obsidian samples from Monte Arci, Palmarola, Lipari, Pantelleria, Gyali and Melos. This database may be used by other laboratories provided the X-ray intensity of the trace elements Rb, Sr, Y, Zr, Nb are measured as net intensities, that is purified from the contribution of the background and from interelemental interferences. A comparison between data obtained with two spectrometers, of different generation and differently calibrated, confirmed the possibility of obtaining a database that can be shared with other laboratories. The proposed XRF method was tested on Neolithic obsidians from four Apulian sites (Ripa Tetta at Lucera, Palestra ex G.I.L. at Foggia, Pulo di Molfetta and Grotta di Santa Barbara at Polignano a Mare), whose source outcrops had been also determined by SEM-EDS.

Waxy maize starch was subjected to crosslinking, HMT, crosslinking-HMT and HMT-crosslinking, and physicochemical properties and digestibility were examined. Crosslinked-HMT and HMT-crosslinked starch exhibited lower and higher phosphorus contents than crosslinked starch at the same concentrations of STMP/STPP (99:1, w/w), respectively. A low swelling power, a low paste clarity, a high melting temperature and a low ΔH were observed in crosslinked-HMT starch and HMT-crosslinked starch like crosslinked and/or HMT starch. Crosslinking-HMT and HMT-crosslinking mitigated the reduced XRD peak intensity observed for HMT. Crosslinked-HMT starch effectively produced RS, showing 28.7–41.5% RS in raw starch and 23.3–25.0% in gelatinized starch. The RS proportion of crosslinking-HMT was similar to that of crosslinking in raw starch, but HMT and crosslinking-HMT showed similar RS proportions in gelatinized starch. Crosslinking-HMT advantageously produced RS from both crosslinking and HMT; however, this was not observed in HMT-crosslinking.