High-resolution Spectrometer Research Articles

The GAPS Programme at TNG

Context. Due to observational biases, a large fraction of known exoplanets are short-period objects. However, the search for planets began more than 20 yr ago, and so it is already possible – with the use of a suitable dataset – to begin exploring a wider range of the parameter space, such as that encompassing long-period planets. Aims. The aim of this paper is to investigate the presence of long-period giant companions in two systems where one or more planets are already known and for which a long-term trend in the radial velocities (RVs) was noted in previous works. Methods. Over the last 11 yr, we have collected 122 spectra of HD 75898 and 72 spectra of HD 11506 with the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) in the framework of the Global Architecture of Planetary Systems (GAPS) project, from which we derived precise RV and activity indicator measurements. Additional RV data from the High-Resolution Echelle Spectrometer (HIRES) are also used here to increase the total time span. For our RV analysis, we used PyORBIT, an advanced Python tool for the simultaneous Bayesian analysis of RVs and stellar activity indicators. In addition, we used astrometric (Gaia DR3) and imaging archive data to complete our analysis. In particular, we combined RVs and astrometry to better constrain the mass and period of the new long-period companions. Results. We find evidence for one additional long-period companion (gas giant planet or brown dwarf) in both systems considered. The new candidate for HD 75898 has a period of roughly 18 yr and a true mass of around 8.5 Mj. For HD 11506, we confirm the new object (planet d) recently announced using HIRES data but we find that the period and true mass are both almost double the values based on HIRES results (Pd ~ 72 yr, Md ~ 13 Mj). In addition, for HD 75898, we also find evidence of an activity cycle affecting RVs with a period of one order of magnitude lower than found in the literature.

Development and clinical implementation of an LC-HRMS method for ivacaftor, lumacaftor, tezacaftor and elexacaftor in human plasma and breast milk.

The four cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulators, ivacaftor, lumacaftor, tezacaftor, and elexacaftor, have revolutionised the treatment of CF by direct action on the protein target behind the disease's development. The aim was to develop and validate a quantification method for these CFTR modulators in plasma and breast milk to better understand inter-patient variability in pharmacokinetics and treatment outcome, including the risk of adverse drug reactions. The ability to monitor CFTR modulators in breast milk enables the estimation of the exposure of breastfed infant, with a potential concern for CFTR modulator-induced liver injury. The analysis was performed on a Thermo Vanquish Flex Binary UHPLC system coupled to a high-resolution mass spectrometer (HRMS), Thermo Q Exactive. The analytes were detected using positive electrospray ionisation in full scan mode. After sample preparation by protein precipitation, the supernatant was injected onto the LC system and the analytes were separated using a Zorbax SB-C18 Rapid Res HPLC column (3.5µm, 4.6 × 75mm). This is the first published method for CFTR modulators in breast milk. The validated quantification range for ivacaftor is 0.0050-10µg/mL with a coefficient of variation < 6% and a mean accuracy of 97-106%; for lumacaftor, tezacaftor, and elexacaftor, the validated quantification range is 0.050-100µg/mL with a coefficient of variation < 8% and a mean accuracy 93-106%. A simple and sensitive quantification method for CFTR modulators has been developed and used for routine analysis of human plasma and breast milk samples since 2022.

High-Resolution Drift Tube Ion Mobility Spectrometer with Ultra-Fast Polarity Switching.

Besides safety and security applications, ion mobility spectrometry (IMS) is increasingly used in other fields such as medicine, environmental monitoring and food quality analysis. However, some applications require gas chromatographic separation before analysis by IMS. Furthermore, different compounds in the sample may form positive or negative ions during ionization and therefore simultaneous detection of both ion polarities is highly beneficial to avoid two chromatographic runs of the same sample. This can be achieved by ultra-fast polarity switching of a single drift tube IMS, allowing for quasi-simultaneous detection of both ion polarities. By using a ramped aperture voltage during the switching process, we overcome the issue of excessive displacement currents at the detector during polarity switching, which usually lead to overdriving the output signal of the high-gain transimpedance amplifier. Furthermore, mechanical aperture grid oscillations caused by polarity switching were also reduced through the ramped aperture voltage. This enables a polarity switching time of only 7 ms at a drift voltage of 8 kV and a drift length of 103 mm, leading to a high resolving power of RP = 117. Requiring 50 ms to acquire a pair of positive and negative spectrum, the IMS achieves an acquisition rate of 20 Hz. It reaches limits of detection of 20 pptv for dimethyl methylphosphonate and 40 pptv for methyl salicylate. For demonstration, different hop varieties were investigated and could be clearly differentiated by considering both, the positive and negative spectra.

Atomic Transition Probabilities for Ultraviolet and Optical Lines of Tm ii * *Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS5-26555 (program GO-15657). This paper also includes data gathered with the 6.5 m Magellan Telescopes

We report new branching fraction measurements for 224 ultraviolet and optical transitions of Tm ii. These transitions range in wavelength (wavenumber) from 2350 to 6417 Å (42,532–15,579 cm−1) and originate in 13 odd-parity and 24 even-parity upper levels. Thirty-five of the 37 levels, accounting for 213 of the 224 transitions, are studied for the first time. Branching fractions are determined for two levels studied previously for comparison to earlier results. The levels studied for the first time are high lying, ranging in energy from 35,753 to 54,989 cm−1. The branching fractions are determined from emission spectra from two different high-resolution spectrometers. These are combined with radiative lifetimes reported in an earlier study to produce a set of transition probabilities and log(gf) values with accuracy ranging from 5% to 30%. Comparison is made to experimental and theoretical transition probabilities from the literature where such data exist. These new log(gf) values are used to derive an abundance from one previously unused Tm ii line in the UV spectrum of the r-process-enhanced metal-poor star HD 222925, and this abundance is consistent with previous determinations based on other Tm ii lines.

Mechanistic investigation of azo dye removal from carbon-deficient dyeing wastewater using horizontal-vertical constructed wetlands

Azo dye degradation can be achieved by simulating a series of anaerobic and aerobic conditions within the constructed wetland (CW) system. The current investigation evaluated the effectiveness of a baffled horizontal-vertical CW system, planted with Typha angustifolia, simulating anaerobic-aerobic conditions to treat carbon-deficient synthetic dyeing wastewater containing 100 mg/L Reactive Yellow 145 (RY145) azo dye. In the absence of an available carbon source in dyeing wastewater, an optimum quantity of sodium acetate was supplemented as the substrate for microbial degradation of RY145. Influent dyeing wastewater characteristics were 5555 ADMI colour, 461 mg/L chemical oxygen demand (COD) and 39 mg/L total nitrogen (TN). During the operation period, the CW system achieved 97% colour, 87% COD, 95% ammonium nitrogen (NH4+-N) and 71% TN removals at 4 d hydraulic retention time (HRT). Favourable environmental conditions, such as low redox conditions and substrate availability in horizontal CW, contributed to a significant reduction in colour (96%). Most TN reduction (67%) happened in horizontal CW by denitrification and plant assimilation. The metagenomic study revealed that Proteobacteria, Bacteroidetes, Chloroflexi and Firmicutes were responsible for pollutant degradation within horizontal CW. The UV–visible spectra and high-resolution liquid chromatograph mass spectrometer (HR-LCMS) analysis confirmed that dye degradation intermediates generated from the breakage of azo bonds were eliminated in vertical CW with high redox conditions. The results of the phytotoxicity and fish toxicity experiments demonstrated a substantial toxicity reduction in the CW system-treated effluent.

Accessing the Characteristics of Nuclear Reactions: A Radioactive Decay and Half-Life Measurement Study

This study investigates the impact of external environmental factors, specifically electromagnetic fields and pressure variations, on the decay constants and half-lives of three radioactive isotopes: 60Co, 137Cs, and 226Ra. By conducting controlled laboratory experiments, the research aimed to quantify the extent to which these factors influence decay rates, challenging the traditional assumption of invariant half-lives. The isotopes were exposed to varying levels of electromagnetic fields (0-100 Gauss) and pressure (1-10 atm), with decay rates measured using high-resolution gamma-ray spectrometers. The results revealed that while 137Cs exhibited the most significant sensitivity, with a 13.04% increase in decay constant under extreme conditions, 60Co and 226Ra showed moderate and minimal changes, respectively. These findings have important implications for fields such as nuclear medicine, radiometric dating, and nuclear waste management, where precise knowledge of decay rates is crucial. The study contributes to a deeper understanding of nuclear decay processes and highlights the need for further research on the effects of other environmental factors, such as temperature and chemical composition, on radioactive decay.

Mid-infrared high-resolution dual-comb spectroscopy: Intensity, broadening, and beyond-Voigt parameters of [formula omitted] and [formula omitted] lines

Using a high-resolution mid-infrared dual-comb spectrometer operating in the 1300 cm−1 spectral region, spectra of acetylene were recorded at room temperature. Spectroscopic parameters were measured in 3 vibrational bands of both 12C2H2 and 13C12CH2. Absolute line intensities (S0) and self-broadening coefficients (γ0self) were determined in the ν4+ν5, 2ν42+ν5−1⟵ν41 and ν41+2ν50⟵ν51 bands. For the main isotopologue, the collisional narrowing coefficients (ν0VC) as well as the speed-dependence of the broadening (γ2) and shifting (δ2) coefficients were measured in the ν4+ν5 band of the main isotopologue of acetylene. Theoretical line-shape models were fitted on experimental profiles using a homemade multi-spectrum fitting procedure to determine spectroscopic parameters. Excellent agreement with the literature was found for self-broadening coefficients and absolute line intensities in the ν4+ν5 band of 12C2H2. For the hot bands, good agreement with the literature is found within experimental uncertainties, while γ0self of those hot bands are also reported for the first time. Similarly, the rotational dependence of ν0VC is found to be close to previous works. γ2 and δ2 of 12C2H2, as well as S0 and γ0self of 13C12CH2 are also reported for the first time in this band.

Temperature dependence of line shape parameters for N2- and O2-broadened methane lines by quantum cascade laser spectroscopy

This paper report nitrogen- and oxygen-broadening coefficients, their speed-dependencies, and the collisional narrowing parameters of lines in the ν4-band of methane. The parameters were determined from low (150 K) to high temperatures (600 K). The measurements were done with a high-resolution quantum cascade laser spectrometer coupled to specific absorption cells that allow to cool and heat the gas mixtures with a great stability. The spectroscopic parameters were determined at each temperature by fits of the experimental absorbances in a multispectrum fitting procedure using the Voigt, Speed-Dependent Voigt, Nelkin-Ghatak and Speed-dependent Nelkin-Ghatak theoretical line shape models. The temperature dependencies of the collisional half-widths, the speed-dependence of the broadening coefficients as well as the collisional narrowing parameters were studied with the empirical power law and the physics-based Gamache-Vispoel model (DPL) [Gamache and Vispoel, JQSRT, 217, 440–452, 2018]. The obtained line shape parameters and their temperature dependencies are compared, when possible, to existing data in literature. The DPL reproduces more accurately the evolution of the studied collisional parameters over the wide range of temperature considered in the study.

Identification of an optimal ground-based validation site for FLEX and quantification of uncertainties using airborne HyPlant data - A case study in Italy

The Fluorescence Explorer (FLEX) satellite will carry the high-resolution Fluorescence Imaging Spectrometer (FLORIS) that measures the complete fluorescence spectrum emitted by chlorophyll of terrestrial vegetation. This small signal must be validated. One validation approach is comparing the fluorescence signal retrieved from satellite-based measurements with ground based measurements. However, the difference in spatial resolution of the satellite and ground-based instruments and a geolocation mismatch will result in differences in the detected signal and thus, in uncertainties of the validation strategy. In a case study, we identify a representative ground site for validating the fluorescence signal by analyzing surface reflectance measurements from an aeroplane.We define requirements of representativeness for a validation ground site in vegetated areas. Based on those requirements, we identify a suitable position within a case study in central Italy using surface reflectance data from the airborne High-Performance Airborne Imaging Spectrometer (HyPlant) measured in summer 2018. The representativeness is quantified by the relative difference between the single HyPlant pixel representing a ground-based measurement and the averaged signal of several HyPlant pixels that mimics a FLORIS pixel. With this measure, we quantify the validation uncertainty due to spatial resolution and geolocation mismatch. The effect of the temporal evolution of the surface properties on the validation uncertainty due to spatial resolution is investigated.We select the ground site position by minimizing the validation uncertainty due to spatial resolution. Especially for wavelengths larger than 700 nm, this uncertainty is smaller than 2 % for all different reference areas. The largest differences between ground-based like measurement and satellite-like measurement of the surface reflectance is due to geolocation mismatch. The uncertainty due the geolocation mismatch is very large for wavelengths smaller than 720 nm and moderate for wavelengths larger than 720 nm. Thus, the surface reflectance at the chosen position for the validation site is not homogeneous enough for validation purpose. Considering a reference area of 13.5 × 13.5 m2, we quantify temporal stable and small uncertainties for the spectral range between 720 and 800 nm. For an all-embracing validation of the surface reflectance of vegetated areas, the chosen site is not appropriate.

Compact broadband high-resolution real-time four-dimensional imaging spectrometer

A broadband high-resolution real-time four-dimensional imaging spectrometer (HRRFDIS) is presented, which can acquire both broadband fine spectra and high-resolution three-dimensional (3D) spatial images of a 3D object in real time. The HRRFDIS consists of a first microlens array arranged in a plane to achieve orthographic view spatial imaging, a second microlens array arranged on a conical surface to measure the depth and to achieve 360-degree side-view spatial imaging, multiple optical fibers, a collimating microlens array arranged in a straight line, a parallel planar transmission grating pair to obtain high spectral resolution over a broadband spectral range, and an area-array detector. Compared with the scanning four-dimensional imaging spectrometer (FDIS), the HRRFDIS can obtain a broadband high-resolution four-dimensional dataset using only one frame of data, and it is more stable, compact, small-sized, and lightweight. Compared to the staring FDIS using a liquid crystal filter and requiring at least one modulation period of liquid crystal to acquire a complete hyperspectral image, the HRRFDIS can acquire a complete broadband hyperspectral image in real time. Compared to existing snapshot FDIS, the HRRFDIS can achieve much higher spectral resolution, especially over a broadband spectral range. The HRRFDIS is a unique concept that is the first to obtain both high-resolution broadband spectral information and high-resolution 3D spatial information in real time, to the best of our knowledge. The HRRFDIS will be suitable for real-time measurement of 3D objects in the ultraviolet to infrared spectral range.

Design, Synthesis and Evaluation of a Novel Teoptinib Derivative as an Effective Anti-hepatocellular Carcinoma Agent.

Hepatocellular Carcinoma (HCC) is a type of liver cancer known for its poor prognosis and high mortality. Teoptinib is a highly selective MET inhibitor that has been used in the treatment of liver cancer. Although good progress has been made in clinical treatment, further improvement is still needed. In this study, a series of novel Teoptinib derivatives were synthesized and evaluated as anti-cancer agents for the treatment of liver cancer, and an oral nanodrug delivery system was also explored. A series of novel Teoptinib derivatives were synthesized, and an oral nanodrug delivery system was also explored. HPLC, high-resolution mass spectrometer and NMR were used to determine the structure and molecular formula of the synthesized compounds. Zeta potential assay was used to access the particle size distribution and zeta potential of the nanoparticles. MTT assay, cell colony formation assay, cell apoptosis inhibition assay, cell scratch assay, and the MHCC-97H xenograft model of nude mice assay were used to evaluate the in vitro and in vivo anti-tumor activity of the synthesized compounds. Compound (R)-10 showed the best antitumor activity with 0.010 μM of the IC50 value against MHCC-97H, a human liver cancer cell line with high c-Met expression. The MHCC-97H xenograft model of nude mice assay showed that nano-prodrug of compound (R)-10 exhibited good in vivo activity with 87.67% of the TGI at the dosage of 8 mg/kg. We designed and synthesized a series of c-Met inhibitors containing different side chains and chiral centers as anti-liver cancer agents. Among them, compound (R)-10 shows a promising effect as a lead molecule for further study in the treatment of liver cancer. The successful incorporation of (R)-10 into a novel oral nanodrug delivery system highlights the importance of effective drug delivery systems for enhanced therapeutic efficacy.

The marriage between stable isotope ecology and plant metabolomics - new perspectives for metabolic flux analysis and the interpretation of ecological archives.

Even though they share many thematical overlaps, plant metabolomics and stable isotope ecology have been rather separate fields mainly due to different mass spectrometry demands. New high-resolution bioanalytical mass spectrometers are now not only offering high-throughput metabolite identification but are also suitable for compound- and intramolecular position-specific isotope analysis in the natural isotope abundance range. In plant metabolomics, label-free metabolic pathway and metabolic flux analysis might become possible when applying this new technology. This is because changes in the commitment of substrates to particular metabolic pathways and the activation or deactivation of others alter enzyme-specific isotope effects. This leads to differences in intramolecular and compound-specific isotope compositions. In plant isotope ecology, position-specific isotope analysis in plant archives informed by metabolic pathway analysis could be used to reconstruct and separate environmental impacts on complex metabolic processes. A technology-driven linkage between the two disciplines could allow us to extract information on environment-metabolism interaction from plant archives such as tree rings but also within ecosystems. This would contribute to a holistic understanding of how plants react to environmental drivers, thus also providing helpful information on the trajectories of the vegetation under the conditions to come.

Proprotein Convertase Subtilisin/Kexin Type 9 Induction in COVID-19 Is Poorly Associated with Disease Severity and Cholesterol Levels.

SARS-CoV-2 infection was shown to induce proprotein convertase subtilisin/kexin type 9 (PCSK9) plasma levels in sepsis. Here, we investigate the association between serum PCSK9 levels and disease severity. PCSK9 was measured in serum of 55 controls, 40 patients with moderate and 60 patients with severe COVID-19 disease. Serum PCSK9 was elevated in moderate COVID-19 compared to controls and further increased in severe cases. PCSK9 levels were not associated with C-reactive protein, bacterial superinfections, interventions, or survival in patients with severe COVID-19. PCSK9 regulates circulating cholesterol levels, and 15 cholesteryl ester (CE) species and free cholesterol (FC) were quantified by direct flow injection analysis using a high-resolution hybrid quadrupole-Orbitrap mass spectrometer. Most CE species with shorter fatty acid chains were decreased in severe compared to moderate COVID-19, and none of the CE species were correlated with PCSK9 in patients with severe COVID-19. Levels of all CE species negatively correlated with C-reactive protein in severe COVID-19 patients. Notably, FC was induced in severe compared to moderate COVID-19. The FC/CE ratio correlated positively with inflammatory markers and was associated with non-survival. The current study suggests that the imbalance between CE and FC levels is associated with disease severity and mortality in patients with COVID-19.

Highly efficient and recyclable chromium/nitrogen-doped carbon nanotube catalysts with unexpected active sites for conversion of fructose into 5-hydroxymethylfurfural

5-Hydroxymethylfurfural (HMF) has great promise as a versatile platform chemical for the synthesis of a wide range of other chemical compounds. The preparation of HMF from carbohydrates for industrial applications, especially fuels and fine chemicals, has received much more attention. In the present study, metal/nitrogen-doped carbon nanotubes (M/N-CNTs) were produced using a one-step carbonization method and used as an exceptional catalyst for converting fructose to HMF. The catalyst structure was determined using Energy-dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), High-resolution X-ray Photoelectron Spectrometer (HRXPS), Transmission Electron Microscopy (TEM), Brunauer-Emmett-Teller (BET), and Fourier-transform Infrared Spectroscopy (FT-IR) techniques. The effects of temperature, catalytic loading, substrate feed concentrations, solvents, reusability, and scalability were carried out. This work achieved an excellent yield of HMF (91 % ± 2) utilizing Cr/N-CNTs as a catalyst for producing HMF at 120 °C for 180 min. Furthermore, the Cr/N-CNTs could be recovered and reused in industrial applications without significant loss of the catalytic activity.

Multi-delay coherence imaging spectroscopy optimized for ion temperature measurements in the divertor plasma of the Wendelstein 7-X stellarator

A new coherence imaging spectroscopy (CIS) diagnostic optimized to measure the C2+ impurity ion temperature Ti spatial distribution in the divertor plasma of the W7-X stellarator is designed, tested, and validated. Using CIS to obtain Ti in the edge of magnetically confined plasmas has historically been challenging because Doppler broadening and Zeeman splitting have comparable effects on the shape of spectral emission lines. To distinguish between these two mechanisms, a novel approach to birefringent crystal design is employed to minimize the diagnostic’s sensitivity to Zeeman splitting. The recently developed pixelated multi-delay CIS approach is also used to obtain four times as much spectral information as traditional CIS approaches. The Ti-optimized CIS diagnostic is validated in a long-pulse W7-X plasma by comparison with a high-resolution spectrometer whose sightlines overlap with the CIS field of view. The CIS and spectrometer Ti profiles have the same shape and agree to within 10% on average and 25% in the worst case. Images of the Ti distribution near the divertor show toroidally elongated bands aligned with the magnetic field, with Ti ranging between 10 and 40 eV.

Monitoring cis-to-trans isomerization of azobenzene using Brillouin microscopy

Brillouin spectroscopy is commonly used to study the acoustic properties of materials. Here we explored its feasibility in studying the photoinduced isomerization of azobenzene. The isomerization of azobenzene changes the solution elastic modulus, and Brillouin scattering is sensitive to these changes. In this study, we experimentally demonstrated the photoswitching of azobenzene in DMSO using our home-made virtually imaged phased array-based high-resolution optical Brillouin spectrometer, and confirmed the results by ultraviolet–visible spectrophotometry. Remarkable Brillouin frequency shift variations were quantitatively recorded upon irradiation, and it was found that this method can indeed be used to monitor the isomerization process in situ. Importantly, our strategy also allows us to provide the relationship between the fraction of trans- and cis- azobenzene and the Brillouin frequency shift. This shows that Brillouin spectroscopy has broad prospects for the characterization of azobenzene isomerization and other photoresponsive materials.

High-precision Transition Energy Measurements of Neon-like Fe xvii Ions

We improve by a factor of 4–20 the energy accuracy of the strongest soft X-ray transitions of Fe xvii ions by resonantly exciting them in an electron beam ion trap with a monochromatic beam at the P04 beamline of the PETRA III synchrotron facility. By simultaneously tracking instantaneous photon-energy fluctuations with a high-resolution photoelectron spectrometer, we minimize systematic uncertainties down to 10–15 meV, or velocity equivalent ±∼5 km s−1 in their rest energies, substantially improving our knowledge of this key astrophysical ion. Our large-scale configuration-interaction computations include more than 4 million relativistic configurations and agree with the experiment at a level without precedent for a 10-electron system. Thereby, theoretical uncertainties for interelectronic correlations become far smaller than those of quantum electrodynamics (QED) corrections. The present QED benchmark strengthens our trust in future calculations of many other complex atomic ions of interest to astrophysics, plasma physics, and the development of optical clocks with highly charged ions.

Novel differential pumping system with extended sampling range: Design and application in the EAST tokamak

A novel differential pumping system (DPS) with an adjustable sampling rate has been developed and implemented in the Experimental Advanced Superconducting Tokamak (EAST). This system is equipped with a high-resolution quadrupole mass spectrometer (QMS), covering a mass range of 1–16 atomic mass units (AMU), alongside a conventional QMS with a broader range of 1–200 AMU. The DPS features a dynamic pressure sampling capability from 10−2 to 105 Pa, utilizing a gas dosing valve and an angle valve, enabling a wide gas sampling ratio range of 10−9 to 3 × 10−2. The high-resolution QMS (QMG700) is adept at directly quantifying the partial pressures of deuterium and helium within mixtures, while the conventional QMS (RGA200) offers indirect measurement of D2 partial pressures above 2 × 10−5 Pa, complemented by direct wide-range mass analysis. During the EAST tokamak campaigns of 2023 and 2024, the DPS was effectively utilized for glow discharge cleaning (GDC) at a pressure of 3 Pa and ion cyclotron wall conditioning (ICWC) at approximately 3 × 10−3 Pa, accurately distinguishing deuterium pressure from the helium environment in the wide pressure range of vacuum vessel. Moreover, the DPS was successfully employed to trace the vacuum leak location in EAST campaign with a pressure of up to hundreds Pa. This DPS is a key tool for gas ingredient analysis and leak detection in the EAST campaigns, providing a valuable reference for the vacuum operation of future fusion reactors.

An effective LC-MS method for the simultaneous determination of a potential anti-rheumatoid arthritis drug, carboxyamidotriazole, and its major metabolite in rat plasma.

Carboxyamidotriazole (CAI) was previously recognized as a well-tolerated anticancer drug. It has also demonstrated significant anti-inflammatory effects in various cell and animal model experiments, prompting its investigation as a potential treatment for rheumatoid arthritis. In this study, the potential biotransformation metabolites of CAI were identified both in vitro and in vivo. A sensitive, specific, and accurate LC-MS method was developed for the quantitative analysis of CAI and its major metabolite, CAI-OH, in rat plasma. CAI, CAI-OH, and telmisartan (used as an internal standard) were separated using a Zorbax SB C18 column. The mobile phase consisted of water (phase A, containing 0.1% formic acid) and acetonitrile (phase B, containing 0.1% formic acid) at a flow rate of 0.2 mL/min. The analytes were examined using a high-resolution mass spectrometer, with detected mass-to-charge ratios of m/z 424.01293 for CAI, m/z 440.00785 for CAI-OH, and m/z 515.24415 for telmisartan. Good linearity was observed within the range of 10-5000 ng/mL. Both inter- and intra-batch precision (relative standard deviation, %) were below 6%, and the accuracy ranged from 94.9% to 106.1%. The analytes remained stable throughout the entire experimental period. This method was successfully applied in a pharmacokinetic study of CAI following oral administration in rats.

The tri-band high spectral resolution spectrometer with gratings in tandem for the charge-exchange recombination spectroscopy diagnostic system on HL-2A tokamak

Charge-exchange (CX) recombination spectroscopy is a powerful tool monitoring ion temperature and plasma rotation with good temporal and spatial resolutions. A compact, new design for a high-throughput, tri-band high spectral resolution spectrometer has been developed for the charge-exchange recombination spectroscopy measurement on the HL-2A tokamak. The simultaneous measurements of He II (468.57 nm), C VI (529.1 nm), and Dα (656.1 nm accompanied by beam emission spectra) with an acquisition frequency up to 400 Hz are achieved by vertically binning the spectrum from each fiber in experiments. Initial results indicate that the system can provide radial profiles of not only ion temperature and rotation velocity, but also concentration of carbon. For the case of helium, the measurements for the ion temperature and rotation velocity are straightforward but the apparent concentration associated with the observed CX intensity is obviously too high. Modeling of the active He II CX feature including plume contributions needs to be carried out to extract the true helium concentration. The spectrometer could become a prototype for the ITER charge-exchange recombination spectroscopy diagnostic and the pilot experiments, as presented here, demonstrate the possibility of impurity concentrations measurements based on the combined measurement of local beam emission and charge-exchange recombination spectroscopy spectra.