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41.
High concentrations of total plasma thiols such as cysteine and homocysteine are important risk factors for atherosclerosis and cardiovascular diseases. We have recently described a new laser-induced fluorescence capillary electrophoresis (CE-LIF) method to measure total plasma thiols, in which the baseline separation of cysteinylglycine, homocysteine, cysteine, and glutathione was achieved by adding the organic base N-methyl-D-glucamine to the run buffer. However, because the active fractions of homocysteine and cysteine responsible for vascular injuries are still unknown, research calls for a set up of methods able to analyze different forms of plasma thiols. In this paper, we present an improvement of our previous method that allows the measurement of different thiol forms. Total, reduced, and free thiols were measured by varying the order of disulfide reduction with tributylphosphine and proteins precipitation with 5-sulfosalicylic acid. After derivatization with 5-iodoacetamidofluorescein, samples were separated and measured by CE-LIF using a phosphate/borate buffer in the presence of 75 mmol/L N-methyl-D-glucamine. Oxidized thiols and protein bound thiols were calculated by difference, free minus reduced and total minus free form, respectively. Linearity, reproducibility, analytical recovery, and sensitivity were evaluated. The assay was used to measure the thiols redox status in 15 plasma samples from healthy volunteers. 相似文献
42.
Zinellu A Sotgia S Pasciu V Madeddu M Leoni GG Naitana S Deiana L Carru C 《Electrophoresis》2008,29(14):3069-3073
We present a new rapid CE method to measure adenine nucleotides adenosine 5'-triphosphate (ATP), adenosine 5'-diphosphate (ADP), and adenosine 5'-monophosphate (AMP) in cells. The short-end injection mode allows a decrease in the analysis time by injecting samples at the outlet end of a silica capillary closest to the detection window, reducing the migration distance. Moreover, the use of methylcellulose (MC) as run buffer additive to suppress EOF permits to further reduce the migration times of analytes. Thus, when a capillary with an effective length of 10.2 cm was used with a 60 mmol/L sodium acetate buffer pH 3.80 in the presence of 0.01% of MC, the migration time of analytes were 1.35 min for ATP, 1.85 min for ADP, and 4.64 min for AMP. These conditions gave a good reproducibility for intra- and interassay (CV <4 and 8%, respectively) and all the procedure demonstrated an excellent analytical recovery (from 98.3 to 99 %). The method suitability was proved both on red blood cells and in spermatozoa. We compared our proposed method to a spectrophotometric assay, by measuring ATP levels in 40 spermatozoa samples. The obtained data were analyzed by the Passing and Bablok regression and Bland-Altman test. 相似文献
43.
As for the commonly studied La0.6Sr0.4Co0.2Fe0.8O3-δ (6428), here, a very low area-specific resistance (ASR) was measured for La0.6Sr0.4Co0.8Fe0.2O3-δ (6482) cathode deposited on a Ce0.9Gd0.1O2-δ (GDC) electrolyte with addition of a thin (1 μm) dense LSCF film deposited by spin coating at the interface between the GDC electrolyte and a 40-μm-thick screen-printed electrode. The ASR ranged from 1 Ω.cm2 at 500 °C, 0.11 Ω.cm2 at 625 °C and value as low as 0.03 Ω.cm2 at 700 °C. Impedance spectra collected in between 500 and 700 °C were carefully studied. They could all be modelled with two R//CPE in series which are likely associated to the oxygen reduction reaction itself (dissociation/adsorption/ionization) at low frequency and to the oxide ion transfer at the electrode/electrolyte interface at high frequency. 相似文献
44.
Alessandro G. Fois Panagiotis Paliogiannis Valentina Scano Stefania Cau Sergio Babudieri Roberto Perra Giulia Ruzzittu Elisabetta Zinellu Pietro Pirina Ciriaco Carru Luigi B. Arru Alessandro Fancellu Michele Mondoni Arduino A. Mangoni Angelo Zinellu 《Molecules (Basel, Switzerland)》2020,25(23)
Background. The rapid onset of a systemic pro-inflammatory state followed by acute respiratory distress syndrome is the leading cause of mortality in patients with COVID-19. We performed a retrospective observational study to explore the capacity of different complete blood cell count (CBC)-derived inflammation indexes to predict in-hospital mortality in this group. Methods. The neutrophil to lymphocyte ratio (NLR), derived NLR (dNLR), platelet to lymphocyte ratio (PLR), mean platelet volume to platelet ratio (MPR), neutrophil to lymphocyte × platelet ratio (NLPR), monocyte to lymphocyte ratio (MLR), systemic inflammation response index (SIRI), systemic inflammation index (SII), and the aggregate index of systemic inflammation (AISI) were calculated on hospital admission in 119 patients with laboratory confirmed COVID-19. Results. Non-survivors had significantly higher AISI, dNLR, NLPR, NLR, SII, and SIRI values when compared to survivors. Similarly, Kaplan–Meier survival curves showed significantly lower survival in patients with higher AISI, dNLR, MLR, NLPR, NLR, SII, and SIRI. However, after adjusting for confounders, only the SII remained significantly associated with survival (HR = 1.0001; 95% CI, 1.0000–1.0001, p = 0.029) in multivariate Cox regression analysis. Conclusions. The SII on admission independently predicts in-hospital mortality in COVID-19 patients and may assist with early risk stratification in this group. 相似文献
45.
Luo Junhua Liang Xinghua Zhang Yuhao Liang Chenghua Yassine Hassan Leroy Gérard Carru Jean-Claude Mascot Manuel 《Journal of Solid State Electrochemistry》2021,25(8-9):2225-2233
Journal of Solid State Electrochemistry - In lithium battery research, when we need to establish equivalent circuit based on impedance measurement, we can find several suitable circuit models. We... 相似文献
46.
Antonio Monopoli Giovanni Ventura Andrea Aloia Fulvio Ciriaco Angelo Nacci Tommaso R. I. Cataldi Cosima D. Calvano 《Molecules (Basel, Switzerland)》2022,27(8)
A significant area of study and upgrading for increasing sensitivity and general performances of matrix-assisted laser-desorption ionization (MALDI) mass spectrometry (MS) is related to matrix design. Several efforts have been made to address the challenge of low-mass-region interference-free for metabolomics analysis and specifically for lipidomics. To this aim, rationally designed matrices as 4-chloro-α-cyanocinnamic acid (ClCCA) were introduced and reported to provide enhanced analytical performances. We have taken this rational design one step further by developing and optimizing new MALDI matrices with a range of modifications on the CHCA core, involving different functionalities and substituents. Of particular interest was the understanding of the electron-withdrawing (e.g., nitro-) or donating (e.g., methoxy-) effects along with the extent of conjugation on the ionization efficiency. In the present work, ten matrices were designed on a reasonable basis, synthesized, and characterized by NMR and UV spectroscopies and laser desorption ionization. With the assistance of these putative MALDI matrices, samples containing phospholipids (PL), and neutral di-/tri-acylglycerols (DAG, TAG) were investigated using milk, fish, blood, and human plasma extracts. In comparison with CHCA and ClCCA, four of them, viz. [(2E,4E)-2-cyano-5-(4-methoxyphenyl)penta-2,4-dienoic acid] (1), [(2E,4E)-2-cyano-5-(4-nitrophenyl)penta-2,4-dienoic acid] (2), [(E)-2-cyano-3-(6-methoxynaphthalen-2-yl)acrylic acid] (6) and [(E)-2-cyano-3-(naphthalen-2-yl)acrylic acid] (7) displayed good to even excellent performances as MALDI matrices in terms of ionization capability, interference-free spectra, S/N ratio, and reproducibility. Especially compound 7 (cyano naphthyl acrylic acid, CNAA) was the election matrix for PL analysis and matrix 2 (cyano nitrophenyl dienoic acid, CNDA) for neutral lipids such as DAG and TAG in positive ion mode. 相似文献
47.
Simultaneous determination of citrulline and arginine in human blood plasma by capillary electrophoresis with ultraviolet absorption detection
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Mauro Forteschi Salvatore Sotgia Gianfranco Pintus Angelo Zinellu Ciriaco Carru 《Journal of separation science》2014,37(17):2418-2423
A new capillary electrophoresis method to measure human blood plasma arginine and citrulline levels in a single run without derivatization was established. After adding homoarginine as internal standard, plasma proteins were removed by a 90:10 v/v acetonitrile/ammonia mixture. Arginine and citrulline were detected by an ultraviolet detector at 190 nm and separated in 11.65 and 20.43 min, respectively, by using a 75 mmol/L Tris phosphate solution at pH 1.2 as a background electrolyte. Limits of detection were 0.8 and 5 μmol/L for arginine and citrulline, respectively. Precision tests indicated a good repeatability of migration times and of peak area both for citrulline (CV% = 0.82 and 3.19) and arginine (CV% = 0.65 and 2.79). The CV% for intra‐ and interassay tests were, respectively, 1.84 and 3.23 for citrulline and 1.25 and 1.50 for arginine. Mean recovery was 101.5 and 98.5% for citrulline and arginine, respectively. The performance of the developed method was assessed by measuring plasma arginine levels in 52 subjects and the data were compared with those obtained by our previous assay. The new method was then applied to assess plasma citrulline and arginine in ten chronic kidney disease patients under hypolipidemic therapy with statin. 相似文献
48.
Sotgia S Carru C Franconi F Fiori PB Manca S Pettinato S Magliona S Ginanneschi R Deiana L Zinellu A 《Journal of chromatography. A》2008,1185(1):145-150
We propose a new capillary zone electrophoresis method applying short-end injection technique for the fast evaluation of methylcystosine/total cytosine ratio after acidic DNA hydrolysis. By short-end injection and by using a 100 mmol/l Tris solution titrated with 1 mol/l phosphoric acid to pH 3.75 as background electrolyte, cytosine and methylcytosine were separated with a good resolution in less than 1.5 min. Stepwise multiple linear regression with DNA methylation degree as the dependent variable and age, cysteine, homocysteine and methionine as independent variables, showed a negative association with age and that total cysteine is the most important determinant of DNA methylation. 相似文献
49.
Zinellu A Sotgia S Usai MF Zinellu E Lepedda AJ Deiana L Formato M Carru C 《Analytical and bioanalytical chemistry》2008,391(8):2865-2868
We describe a new ultra-rapid capillary electrophoresis method with UV detection for analysis of the disaccharides obtained
after enzymatic depolymerization of plasma chondroitin sulfates. The free reducing groups of the released carbohydrate molecules
are derivatized with 2-aminoacridone by reductive amination in the presence of cyanoborohydride. The fluorotagged products
can be separated by short-end injection capillary electrophoresis in a capillary with an effective length of 10.2 cm. The
migration times of Δdi-0S and Δdi-4S were 0.95 and 1.81 min, respectively. We compared the proposed method with UV detection
to a reference CE-LIF assay by measuring plasma chondroitin sulfate in 94 subjects. The described assay for total plasma CS
measurement may, owing to the high throughput and the fast analytical times, be a good tool for routine studies both in research
and in clinical applications. 相似文献
50.
Michael Andresini Dr. Sébastien Carret Prof. Leonardo Degennaro Dr. Fulvio Ciriaco Prof. Jean-François Poisson Prof. Renzo Luisi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(59):e202202066
The growing interest in novel sulfur pharmacophores led to recent advances in the synthesis of some S(IV) and S(VI) motifs. However, preparation and isolation of uncommon primary sulfinamidines, the aza-analogues of sulfinamides, is highly desirable. Here we report a multistep continuous flow synthesis of poorly explored NH2-sulfinamidines by nucleophilic attack of organometallic reagents to in situ prepared N-(trimethylsilyl)-N-trityl-λ4-sulfanediimine (Tr−N=S=N−TMS). The transformation can additionally be realized under mild conditions, at room temperature, via a highly chemoselective halogen-lithium exchange of aryl bromides and iodides with n-butyllithium. Moreover, the synthetic potential of the methodology was assessed by exploring further manipulations of the products and accessing novel S(IV) analogues of celecoxib, tasisulam, and relevant sulfinimidoylureas. 相似文献