Your browser doesn't support javascript.
Montrer: 20 | 50 | 100
Résultats 1 - 17 de 17
Filtre
1.
LC GC North America ; 40(5):229-231, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-20236205

Résumé

Reducing the molecule complexity is achieved by reducing the molecule size after enzymatic digestion to produce smaller fragments more amenable to LC separation and tandem mass spectrometry (MS/MS) sequencing. Non-denaturing CEX chromatography, size-exclusion chromatogra- phy (SEC), hydrophobic interaction chromatography (HIC), and protein A modes can be easily coupled to reversed-phase LC (RPLC) because of the high aqueous conditions, enabling the versatile 4D-LC-MS systems with the use of alternative modes to 1D CEX, such as SEC or Protein A (6,7). [...]the nanopar-ticle size and free drug concentration are determined at the particle Level, whereas the encapsulated drug and lipids forming the layer are commonly characterized at the molecuar level after denaturing the lipid nanoparticle (LNP) via a surfactant. [...]MDLC-MS setups present a formidable opportunity to unify the characterization of drug delivery systems at the molecular and particle evels, which would enable their high throughput analysis.

2.
LC GC North America ; 40(3):125-127, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-20232686

Résumé

In 2002, the first fully humanized mAb was approved by the U.S. Food and Drug Administration (FDA) (3). [...]the biopharmaceutical industry is still in its infancy and new, more complex products are in development and will ikely dominant the market in the future. [...]the most common forms of LC-MS have limitations when characterizing large macromolecules (4). [...]in this column, we discuss the potential for charge detection MS (CDMS) as an analytical tool for characterizing large, complex, and heterogenous biopharmaceuticals. [...]in October 2021 at the American Association for Mass Spectrometry (ASMS) annua meeting in Philadelphia, TrueMass presented the first commercial CDMS (6,7). The cylinder is often inside an electrostatic linear ion trap (ELIT) instrument, where ions oscillate back and forth. [...]the oscillation frequency gives the m/z and the charge is determined by the magnitude.

3.
Earth System Science Data ; 15(5):1947-1968, 2023.
Article Dans Anglais | ProQuest Central | ID: covidwho-2319341

Résumé

Volatile organic compounds (VOCs) have direct influences on air quality and climate. They indeed play a key role in atmospheric chemistry as precursors of secondary pollutants, such as ozone (O3) and secondary organic aerosols (SOA). In this respect, long-term datasets of in situ atmospheric measurements are crucial for characterizing the variability of atmospheric chemical composition, its sources, and trends. The ongoing establishment of the Aerosols, Cloud, and Trace gases Research InfraStructure (ACTRIS) allows implementation of the collection and provision of such high-quality datasets. In this context, online and continuous measurements of O3, nitrogen oxides (NOx), and aerosols have been carried out since 2012 at the SIRTA (Site Instrumental de Recherche par Télédétection Atmosphérique) observatory, located in the Paris region, France. Within the last decade, VOC measurements were conducted offline at SIRTA, until the implementation of real-time monitoring which started in January 2020 using a proton-transfer-reaction quadrupole mass spectrometer (PTR-Q-MS).The dataset acquired during the first 2 years of online VOC measurements provides insights into their seasonal and diurnal variabilities. The additional long-term datasets obtained from co-located measurements (NOx, aerosol physical and chemical properties, meteorological parameters) are used to better characterize the atmospheric conditions and to further interpret the obtained results. Results also include insights into VOC main sources and the influence of meteorological conditions and air mass origin on their levels in the Paris region. Due to the COVID-19 pandemic, the year 2020 notably saw a quasi-total lockdown in France in spring and a lighter one in autumn. Therefore, the focus is placed on the impact of these lockdowns on the VOC variability and sources. A change in the behaviour of VOC markers for anthropogenic sources was observed during the first lockdown, reflecting a change in human activities. A comparison with gas chromatography data from the Paris city centre consolidates the regional representativity of the SIRTA station for benzene, while differences are observed for shorter-lived compounds with a notable impact of their local sources. This dataset could be further used as input for atmospheric models and can be found at 10.14768/f8c46735-e6c3-45e2-8f6f-26c6d67c4723 (Simon et al., 2022a).

4.
Thorax ; 77(Suppl 1):A2, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-2118680

Résumé

Introduction and ObjectivesNeutrophils are increasingly recognised for a role in acute COVID19, contributing to hyperinflammatory responses, immunothrombosis and tissue damage. However, less is known about the cellular changes occurring within neutrophils in acute disease, as well as neutrophil function in patients recovering from COVID19. Mass spectrometry-based proteomics of neutrophils from hospitalised COVID19 patients sampled longitudinally was utilised to characterise these cells in both acute and long COVID19 (i.e. symptoms for ≥4 weeks).MethodsProspective observational study of hospitalised patients with PCR-confirmed SARS-CoV-2 infection (May 2020–December 2020). Patients were enrolled within 96 hours of admission, with longitudinal sampling up to day 29. Control groups comprised hospitalised patients with non-COVID19 acute respiratory infection and age-matched non-infected controls. Neutrophils isolated from peripheral blood were processed for mass spectrometry. COVID19 severity was defined using the WHO 7-point ordinal scale.Results84 COVID19 patients were included (mean age±SD 65.5±14.6 years;52.4% male), 91 non-COVID19 respiratory infection patients (age 65.7±16.7 years;49.5% male) and 42 non-infected controls (age 58.5±17.9;40% male). 1,748 proteins were significantly different (q-value≤0.05) in COVID19 neutrophils compared to those of non-infected controls. Major differences included a robust interferon response at baseline, with markers of neutrophil immaturity (CD10, CD71), increased neutrophil activation (CD64), and changes in metabolism which associated with COVID19 disease severity. Delayed recovery (WHO score 2–3) at day 29 was associated with significant changes in 1,107 proteins compared to the control population. Features of non-recovery included significantly reduced abundance of migratory receptors (e.g. C3AR1, LTB4R), integrins (CD11b, CD18), inhibitory molecules (e.g. SHP-1, SHIP-1) and indications of increased activation (CD64). Overall, ficolin and specific granule content was decreased in COVID19 patient neutrophils at day 29 compared with controls, however, comparing those who had recovered and those who had not, granule content was found to be significantly lower in the non-recovery group.ConclusionNeutrophils undergo significant changes in acute COVID19 associated with disease severity. Neutrophil proteomics revealed that these cells may have an ongoing role in non-recovered patients, including profiles associated with increased potential for neutrophil activation and reduced migratory capacity, highlighting neutrophils as potential therapeutic targets in long COVID19.

5.
Journal of Composites Science ; 6(8):226, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-2023807

Résumé

Hemodialysis (HD) is a life-sustaining treatment of crucial importance in managing end-stage renal disease (ESRD). However, this membrane-based therapy is associated with acute side-effects due to bioincompatibility issues and limitations on the removal of uremic toxins. The present study assessed the influence of hydrodynamic conditions applied during HD treatment on protein-mediated inflammatory and thrombotic responses. The membrane modules considered are commonly used in Canadian hospitals and are comprised of a polymer blend of polyarylether sulfone-polyvinylpyrrolidone (PAES). The membranes morphology and hydrophilicity were assessed using SEM, AFM, BET, and zeta potential. An in vitro study evaluated the adsorptive behavior of fibrinogen (FB) to the membrane under different flow conditions. Lower rates of 200 mL/min promoted slower and significant FB adsorption, leading to more severe inflammatory and thrombotic responses. Hydrodynamic conditions also affected the concentration of all inflammatory biomarkers. Lower flow rates triggered more complement activation as well as coagulation, clotting, and inflammatory responses compared to higher flow rates. At the end of the dialysis session, patients treated with a Qb of 200 mL/min presented a significant increase in the concentration of C5a (232%), properdin (114%), serpin (545%), IL-1α (50%), IL-6 (450%), and vWF (212%). IL-1β and TNF-α concentrations declined by 12.5 and 35.5%, respectively. Male patients experienced more severe inflammatory responses than female patients at the operating conditions considered. Comparing the pre- and post-dialysis levels of female and male patients, female patients experienced significantly higher levels of IL-6 and properdin, while male patients presented higher levels of C5a, IL-1α, and IL-6. The results of this study will help clinical doctors evaluate the impact of HD operating conditions on blood activations before prescribing treatment and inform expectations for outcomes in female and male patients.

6.
View ; 3(4), 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1958863

Résumé

Pulmonary disease arising from slow‐growing mycobacterial infections has emerged as an increasingly prevalent clinical concern over the past two to three decades. Proteins belonging to the family of ESAT‐6 secretion (Esx) systems play critical roles in the virulence of most pathogenic mycobacterial species and are associated with drug resistance. However, no clinical applications can detect and discriminate the expression of species‐specific variants of these proteins in clinical samples, such as early growth cultures, for rapid diagnosis of specific mycobacterial infections, which may require distinct interventions. Conventional immunoassay approaches are not suitable for this purpose due to the significant degree of conservation of Esx proteins among species. Herein we describe the development of a novel immunoprecipitation‐coupled mass spectrometry assay that can distinguish Esx proteins that are expressed by slow‐growing mycobacterial species commonly detected in clinical isolates. This approach uses custom antibodies raised against single semi‐conserved peptide regions in M. tuberculosis (Mtb) EsxB and EsxN to capture corresponding peptides from protein orthologs of mycobacteria associated with human respiratory infections, including Mtb, M. avium, M. intracellulare, M. kansasii, M. gordonae, and M. marinum, to detect these species in standard clinical cultures at the first sign mycobacterial growth to allow rapid disease diagnosis.

7.
Molecules ; 27(10):3167, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1871828

Résumé

Different groups of organic micropollutants including pharmaceuticals and pesticides have emerged in the environment in the last years, resulting in a rise in environmental and human health risks. In order to face up and evaluate these risks, there is an increasing need to assess their occurrence in the environment. Therefore, many studies in the past couple of decades were focused on the improvements in organic micropollutants’ extraction efficiency from the different environmental matrices, as well as their mass spectrometry detection parameters and acquisition modes. This paper presents different sampling methodologies and high-resolution mass spectrometry-based non-target screening workflows for the identification of pharmaceuticals, pesticides, and their transformation products in different kinds of water (domestic wastewater and river water). Identification confidence was increased including retention time prediction in the workflow. The applied methodology, using a passive sampling technique, allowed for the identification of 85 and 47 contaminants in the wastewater effluent and river water, respectively. Finally, contaminants’ prioritization was performed through semi-quantification in grab samples as a fundamental step for monitoring schemes.

8.
International Journal of Environmental Research and Public Health ; 19(10):6004, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1871619

Résumé

Limited information is available regarding chemical water quality at the tap in Guatemala City, preventing individuals, water utilities, and public health authorities from making data-driven decisions related to water quality. To address this need, 113 participants among households served by a range of water providers across the Guatemala City metropolitan area were recruited as participatory scientists to collect first-draw and flushed tap water samples at their residence. Samples were transported to the U.S. and analyzed for 20 metals and 25 per- and polyfluoroalkyl substances (PFAS). At least one metal exceeded the Guatemalan Maximum Permissible Limit (MPL) for drinking water in 63% of households (n = 71). Arsenic and lead exceeded the MPL in 33.6% (n = 38) and 8.9% (n = 10) of samples, respectively. Arsenic was strongly associated with groundwater while lead occurrence was not associated with location, water source, or provider. One or more PFAS were detected in 19% of samples (n = 21, range 2.1–64.2 ppt). PFAS were significantly associated with the use of plastic water storage tanks but not with location, water source, or provider. Overall, the high prevalence of arsenic above the MPL in Guatemala City tap water represents a potential health risk that current water treatment processes are not optimized to remove. Furthermore, potential contaminants from premise plumbing and storage, including lead and PFAS, represent additional risks requiring further investigation and public engagement.

9.
Water ; 14(10):1560, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1870966

Résumé

Pharmaceuticals and personal care products (PPCPs) were investigated in five wastewater treatment plants (WWTPs), groundwater, irrigated soils, and plants in Amman and Al-Balqa governorates in Jordan. PPCPs were extracted from water samples by solid-phase extraction (SPE) and analyzed by high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC–MS/MS). Carbamazepine, ciprofloxacin, ceftiofur, diclofenac, erythromycin, lincomycin, ofloxacin, pyrimthamine, spiramycin, sulfamethoxazole, sulfapyridine, testosterone, trimethoprim, and thiamphenicol were detected in all raw wastewaters in μg/L, whereas 45 PPCPs were below the detection limits (<0.02 μg/L) in all samples. Na`ur and Abu Nuseir WWTPs showed high PPCPs removal efficiencies in comparison with AL-Baqa`a, Salt, and Fuhais-Mahis WWTPs. Boqorreya spring showed signs of contamination by Salt WWTP effluents as a result of mixing. Irrigation with effluents showed higher carbamazepine concentrations in soils at the top soil layers (0 to 20 cm) in all farms than its concentrations at the root zone (20 to 40 cm) by using drip irrigation system with various plants. In plants, carbamazepine concentration was only detected in high concentration level in mint leaves. In the same farm, diclofenac concentration was detected only in olives and not in twigs and leaves, indicating a high rate of plant uptake especially during the olive’s growth period. Furthermore, plant fruits, leaves, and stems left on the farm after harvesting are generally consumed by cattle, which means entering the food chain of humans.

10.
Chemosensors ; 10(5):180, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1870853

Résumé

This paper reports the results obtained from the determination of ascorbic acid with platinum-based voltammetric sensors modified with potassium hexacyanoferrate-doped polypyrrole. The preparation of the modified electrodes was carried out by electrochemical polymerization of pyrrole from aqueous solutions, using chronoamperometry. Polypyrrole films were deposited on the surface of the platinum electrode, by applying a constant potential of 0.8 V for 30 s. The thickness of the polymer film was calculated from the chronoamperometric data, and the value was 0.163 μm. Cyclic voltammetry was the method used for the Pt/PPy-FeCN electrode electrochemical characterization in several types of solution, including KCl, potassium ferrocyanide, and ascorbic acid. The thin doped polymer layer showed excellent sensitivity for ascorbic acid detection. From the voltammetric studies carried out in solutions of different concentrations of ascorbic acid, ranging from 1 to 100 × 10−6 M, a detection limit of 2.5 × 10−7 M was obtained. Validation of the analyses was performed using pharmaceutical products with different concentrations of ascorbic acid, from different manufacturers and presented in various pharmaceutical forms, i.e., intravascular administration ampoules, chewable tablets, and powder for oral suspension.

11.
Separations ; 9(4):85, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1810114

Résumé

With an increasing appreciation for the unique pharmacological properties associated with distinct, individual cannabinoids of Cannabis sativa, there is demand for accurate and reliable quantification for a growing number of them. Although recent methods are based on highly selective chromatography-mass spectrometry technology, most are limited to a few cannabinoids, while relying on unnecessarily sophisticated and expensive ultra-high performance liquid chromatography and tandem mass spectrometry. Here we report an optimised, simple extraction method followed by a reliable and simple high performance liquid chromatography method for separation. The detection is performed using a time-of-flight mass spectrometer that is available in most natural products research laboratories. Due to the simplicity of instrumentation, and the robustness resulting from a high resolution in the chromatography of isobaric cannabinoids, the method is well suited for routine phytocannabinoid analysis for a range of applications. The method was validated in terms of detection and quantification limits, repeatability, and recoveries for a total of 17 cannabinoids: detection limits were in the range 11–520 pg when using a 1 µL sample injection volume, and the recovery percentages ranged from 85% to 108%. The validated method was subsequently applied to determine cannabinoid composition in the inflorescences of several medicinal Cannabis sativa varieties.

12.
Chemosensors ; 10(3):108, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1760412

Résumé

The smuggling of illicit drugs urges the development of new tools for rapid on-site identification in cargos. Current methods rely on presumptive color tests and portable spectroscopic techniques. However, these methods sometimes exhibit inaccurate results due to commonly used cutting agents, the colorful nature of the sample or because the drugs are smuggled in common goods. Interestingly, electrochemical sensors can deal with these specific problems. Herein, an electrochemical device is presented that uses affordable screen-printed electrodes for the electrochemical profiling of several illicit drugs by square-wave voltammetry (SWV). The identification of the illicit compound is based on the oxidation potential of the analyte. Hence, a library of electrochemical profiles is built upon the analysis of illicit drugs and common cutting agents. This library allows the design of a tailor-made script that enables the identification of each drug through a user-friendly interface (laptop or mobile phone). Importantly, the electrochemical test is compared by analyzing 48 confiscated samples with other portable devices based on Raman and FTIR spectroscopy as well as a laboratory standard method (i.e., gas chromatography–mass spectrometry). Overall, the electrochemical results, obtained through the analysis of different samples from confiscated cargos at an end-user site, present a promising alternative to current methods, offering low-cost and rapid testing in the field.

13.
Applied Sciences ; 12(5):2693, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1736826

Résumé

Featured ApplicationThe improvement of effective remote sensing-based approaches to map macrophyte features can provide a baseline of adequate spatiotemporal resolution for 21st century monitoring applications equipped to play a prominent role in the context of medium–large-scale management programs of ecological conservation and scientific research.Macrophytes are of fundamental importance to the functioning of lake ecosystems. They provide structure, habitat, and a food source and are a required component in monitoring programs of lake ecological quality. The key aim of this study is to document the variation in spatial extent and density of macrophytes seasonally between 2015 and 2020 of the Sirmione Peninsula (Lake Garda, Italy), using Sentinel-2 imagery. In addition to this, our results were compared to previous data from imaging spectrometry;individual parameters affecting macrophyte communities were tested, and the possible effect of the COVID-19 lockdown on macrophyte colonization was evaluated. Satellite images allowed the mapping of the spatiotemporal dynamics of submerged rooted macrophytes in order to support monitoring of the shallow water ecosystem under study. Substantial changes were found in both spatial extent and density over the period from 2015 to 2020, particularly in 2019 when there was almost a complete absence of dense macrophytes. Variables found to influence the amount of macrophytes included transparency, chlorophyll–a, water level, winter wave height, and grazing by herbivores. A separate analysis focusing on areas associated with boat transit found a recovery in macrophyte coverage during the period of COVID-19 lockdown. The outcome of the study highlights a decline in the density of the macrophytes and a shift towards deeper areas compared to the situation in 1997. The area examined is part of an internationally important site containing the highest abundance and diversity of overwintering water birds in Italy. Exploiting satellite data at high frequency provided an insight to understand the dynamic changes and interactions with herbivorous birds, environmental factors, and anthropogenic pressures, revealing a delicately balanced and threatened ecosystem.

14.
Water ; 14(4):588, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1715843

Résumé

The consumption of illicit drugs represents a global social and economic problem. Using suitable analytical methods, monitoring, and detection of different illegal drugs residues and their metabolites in wastewater samples can help combat this problem. Our article defines a method to develop, validate, and practically applicate a rapid and robust analytical process for the evaluation of six naturally occurring cannabinoids (CBG, CBD, CBDV, CBN, THC, THCV), two cannabinoids in acidic form (CBDA, THCA-A), and the major cannabis-related human metabolite (THC-COOH). After SPE offline enrichment, we used a UPLC–ESI-MS/MS system, which permitted the determination of several by-products. Studied matrices were samples of different origins: (i) effluent water from a wastewater treatment plant in the Porto urban area;(ii) environmental water from Febros River, the last left-bank tributary of the Douro River. The multi-residue approach was substantiated and successfully employed to analyze the water samples collected in the above locations. The rapid and precise quantification of nine different cannabinoids in different water samples occurred within nine minutes at the ng L−1 level. The appearance of dozens of ng L−1 of some cannabis secondary metabolites, such as CBD, CBDA, CBN, THCA-A, indicates this plant species’ widespread usage among the general population in the considered area.

15.
Minerals ; 12(2):122, 2022.
Article Dans Anglais | ProQuest Central | ID: covidwho-1715563

Résumé

Due to an extensive history of mining activities common to Mexico, Chile and Australia there is a vast mine waste legacy. Whilst these wastes present ongoing challenges regarding their management, they may represent a source of elements supporting the transition towards a low carbon future. Hence, our study aims to demonstrate the value of establishing a chemical database from publicly available tailings data collated from the three countries to assess their potential as a secondary resource of elements classified as critical or with high economic relevance. Overall, 2976 data samples were identified, analysed and georeferenced from 159, 642 and 7 Mexican, Chilean and Australian deposits, respectively. Data analysis shows that Mexico has significant potential for Bi, Sb, W, In, Zn and Mo with outstanding values in Sonora State, while Chile has significant potential for Bi, Sb, W and Mo, mostly from northern to central regions and Zn to the south. Whilst data from Australia are still being compiled, the potential for Co was recognised. The research exposes that available information is insufficient and highlights the need for an international report or assessment code for mine waste that encourages resource recovery from these resources and circular economy practices.

16.
Analytical Science Advances ; 2(11-12):495-496, 2021.
Article Dans Anglais | ProQuest Central | ID: covidwho-1596044

Résumé

Rendedula et al 2 demonstrated the resolving power and sensitivity of solid-phase extraction (SPE) ultra-high performance liquid chromatograph (UHPLC) hyphenated to quadrupole hybrid Orbitrap mass spectrometry (Q-Orbitrap-MS) in capturing 26 phthalates, pharmaceuticals, and personal care products (PPPCPs) in river water samples from an Indian river, the Ganges. The authors recorded significant alternations in 13 metabolites mainly sugars, amino acids, fatty acids, and organic acids as well as disturbances in five metabolic pathways due to different ripening practice/agents. In another review on the application of magnetic resonance spectroscopy (MRS) in breast cancer, Sharma and Jagannathan 9 compare the technology with mass spectrometry and demonstrate a handful of applications in biomedical research, which goes on to show its enormous potential in capturing the underlying metabolic reprogramming in breast cancer cells, in unravelling molecular biomarkers, and applications in in vitro and ex vivo studies.

17.
Archives of Disease in Childhood ; 106(Suppl 3):A23-A24, 2021.
Article Dans Anglais | ProQuest Central | ID: covidwho-1574518

Résumé

In September 2020, the UK government announced Operation Moonshot;the remit being to increase testing capacity for COVID 19. Amongst the diagnostic platforms to be considered was mass spectrometry. To facilitate this, the Department of Health and Social Care (DHSC) brought together and funded academic mass spectrometry (P1) and specialist NHS laboratories (P2) across the UK.With regards to the latter, the GOSH Enzyme Lab and the Neurometabolic Unit (National Hospital) were identified as a P2 grouping that would collaborate with the mass spectrometry unit at the UCL Institute of Child Health (P1 – Head Prof K Mills). This P1 lab developed a unique proteomic approach to measure diagnostic proteins associated with the SARS-CoV-2 virus.This method was transferred over to our NHS labs for full validation. Rapid progress was made and the DHSC identified us as a ‘vanguard lab’. Within 6 months of commencement of the project, a validated method was developed that had excellent agreement with PCR testing.Our data was used in presentations throughout the DHSC and for briefing of government ministers. Despite the pressures of the pandemic, our NHS staff went above and beyond to deliver on time.Furthermore, close working with an academic partner provided a proof of principle example whereby state of the art mass spectrometry-based methods can successfully be translated across into the NHS environment.

SÉLECTION CITATIONS
Détails de la recherche