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1.
Electrophoresis ; 2024 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-39140227

RESUMO

Omics technologies, such as genomics, proteomics, metabolomics, isotopolomics, and metallomics, are important tools for analytical verification of food authenticity. However, in many cases, their application requires the use of high-resolution technological platforms as well as careful consideration of sample collection, storage, preparation and, in particular, extraction. In this overview, the individual steps and disciplines are explained against the background of the term "Green Chemistry," and the various instrumental procedures for the respective omics disciplines are discussed. Furthermore, new approaches and developments are presented on how such analyses can be made sustainable in the future.

2.
Child Obes ; 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39078739

RESUMO

Interventions in community settings, where children spend substantial out of school time, may enhance access to evidence-based lifestyle interventions. The Boys and Girls Club of Lawrence (BGCL) and New Balance Foundation Obesity Prevention Center at Boston Children's Hospital partnered to revise, enact, and evaluate BGCL's existing Healthy Living Club and then flexibly expand the program to increase access. The BGCL is within walking distance of three public housing communities and easily accessible to members, of whom 90% identify as Hispanic. The interventions comprised nutrition sessions and either fitness activity sessions (N+FA Cycle 1, n = 63, 26 hours; N+FA Cycle 2, n = 94, 27 hours) or academic basketball practices (N+AB Cycle 2, n = 99, 72-80 hours), leveraging time already in the schedule where fitness could be intentionally promoted by coaches. Among children aged 8-15 years, mean [95% confidence interval (CI)] changes (beginning to end) in percentage above the BMI median were significant [N+FA Cycle 1: -2.4 (-4.1, -0.8); N+FA Cycle 2: -4.3 (-5.4, -3.1); N+AB Cycle 2: -5.5 (-6.9, -4.1)]. Lifestyle interventions, implemented with flexibility in existing programs, had beneficial impact, indicating potential of community-academic partnerships.

3.
Molecules ; 29(14)2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-39064927

RESUMO

Element profiling is a powerful tool for detecting fraud related to claims of geographical origin. However, these methods must be continuously developed, as mixtures of different origins in particular offer great potential for adulteration. This study is a proof of principle to determine whether elemental profiling is suitable for detecting mixtures of the same food but from different origins and whether calculated data from walnut mixtures could help to reduce the measurement burden. The calculated data used in this study were generated based on measurements of authentic, unadulterated samples. Five different classification models and three regression models were applied in five different evaluation approaches to detect adulteration or even distinguish between adulteration levels (10% to 90%). To validate the method, 270 mixtures of walnuts from different origins were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). Depending on the evaluation approach, different characteristics were observed in mixtures when comparing the calculated and measured data. Based on the measured data, it was possible to detect admixtures with an accuracy of 100%, even at low levels of adulteration (20%), depending on the country. However, calculated data can only contribute to the detection of adulterated walnut samples in exceptional cases.


Assuntos
Análise de Alimentos , Contaminação de Alimentos , Juglans , Juglans/química , Contaminação de Alimentos/análise , Análise de Alimentos/métodos , Espectrometria de Massas/métodos , Nozes/química
4.
Nat Commun ; 15(1): 3697, 2024 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-38714681

RESUMO

The transition from a humid green Sahara to today's hyperarid conditions in northern Africa ~5.5 thousand years ago shows the dramatic environmental change to which human societies were exposed and had to adapt to. In this work, we show that in the 620,000-year environmental record from the Chew Bahir basin in the southern Ethiopian Rift, with its decadal resolution, this one thousand year long transition is particularly well documented, along with 20-80 year long droughts, recurring every ~160 years, as possible early warnings. Together with events of extreme wetness at the end of the transition, these droughts form a pronounced climate "flickering", which can be simulated in climate models and is also present in earlier climate transitions in the Chew Bahir environmental record, indicating that transitions with flickering are characteristic of this region.

5.
Chembiochem ; 25(12): e202400165, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38616163

RESUMO

Studying the metabolic role of non-essential promiscuous enzymes is a challenging task, as genetic manipulations usually do not reveal at which point(s) of the metabolic network the enzymatic activity of such protein is beneficial for the organism. Each of the HAD-like phosphatases YcsE, YitU and YwtE of Bacillus subtilis catalyzes the dephosphorylation of 5-amino-6-ribitylamino-uracil 5'-phosphate, which is essential in the biosynthesis of riboflavin. Using CRISPR technology, we have found that the deletion of these genes, individually or in all possible combinations failed to cause riboflavin auxotrophy and did not result in significant growth changes. Analysis of flavin and adenylate content in B. subtilis knockout mutants showed that (i) there must be one or several still unidentified phosphatases that can replace the deleted proteins; (ii) such replacements, however, cannot fully restore the intracellular content of any of three flavins studied (riboflavin, FMN, FAD); (iii) whereas bacterial fitness was not significantly compromised by mutations, the intracellular balance of flavins and adenylates did show some significant changes.


Assuntos
Bacillus subtilis , Flavinas , Bacillus subtilis/genética , Bacillus subtilis/metabolismo , Bacillus subtilis/enzimologia , Flavinas/metabolismo , Monofosfato de Adenosina/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Monoéster Fosfórico Hidrolases/metabolismo , Monoéster Fosfórico Hidrolases/genética , Técnicas de Inativação de Genes
6.
ACS Nano ; 18(16): 10798-10806, 2024 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-38593383

RESUMO

A three-terminal memristor with an ultrasmall footprint of only 0.07 µm2 and critical dimensions of 70 nm × 10 nm × 6 nm is introduced. The device's feature is the presence of a gate contact, which enables two operation modes: either tuning the set voltage or directly inducing a resistance change. In I-V mode, we demonstrate that by changing the gate voltages between ±1 V one can shift the set voltage by 69%. In pulsing mode, we show that resistance change can be triggered by a gate pulse. Furthermore, we tested the device endurance under a 1 kHz operation. In an experiment with 2.6 million voltage pulses, we found two distinct resistance states. The device response to a pseudorandom bit sequence displays an open eye diagram and a success ratio of 97%. Our results suggest that this device concept is a promising candidate for a variety of applications ranging from Internet-of-Things to neuromorphic computing.

7.
ACS Infect Dis ; 10(5): 1739-1752, 2024 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-38647213

RESUMO

Reverse analogs of the phosphonohydroxamic acid antibiotic fosmidomycin are potent inhibitors of the nonmevalonate isoprenoid biosynthesis enzyme 1-deoxy-d-xylulose 5-phosphate reductoisomerase (DXR, IspC) of Plasmodium falciparum. Some novel analogs with large phenylalkyl substituents at the hydroxamic acid nitrogen exhibit nanomolar PfDXR inhibition and potent in vitro growth inhibition of P. falciparum parasites coupled with good parasite selectivity. X-ray crystallographic studies demonstrated that the N-phenylpropyl substituent of the newly developed lead compound 13e is accommodated in a subpocket within the DXR catalytic domain but does not reach the NADPH binding pocket of the N-terminal domain. As shown for reverse carba and thia analogs, PfDXR selectively binds the S-enantiomer of the new lead compound. In addition, some representatives of the novel inhibitor subclass are nanomolar Escherichia coli DXR inhibitors, whereas the inhibition of Mycobacterium tuberculosis DXR is considerably weaker.


Assuntos
Aldose-Cetose Isomerases , Antimaláricos , Fosfomicina , Ácidos Hidroxâmicos , Complexos Multienzimáticos , Plasmodium falciparum , Fosfomicina/farmacologia , Fosfomicina/análogos & derivados , Fosfomicina/química , Aldose-Cetose Isomerases/antagonistas & inibidores , Aldose-Cetose Isomerases/metabolismo , Aldose-Cetose Isomerases/química , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/química , Antimaláricos/farmacologia , Antimaláricos/química , Complexos Multienzimáticos/antagonistas & inibidores , Complexos Multienzimáticos/metabolismo , Complexos Multienzimáticos/química , Cristalografia por Raios X , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/síntese química , Relação Estrutura-Atividade , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/enzimologia , Modelos Moleculares , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/enzimologia , Domínio Catalítico , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo
8.
Nutrients ; 16(5)2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38474870

RESUMO

The diagnosis of celiac disease (CD) is complex and requires a multi-step procedure (symptoms, serology, duodenal biopsy, effect of a gluten-free diet, and optional genetic). The aim of the study was to contribute to the improvement of CD diagnosis by preparing a water-soluble gluten peptide fraction (called Solgluten) and by selecting gluten-specific enzyme-linked immunosorbent assays (ELISA) for the detection of gluten immunogenic gluten peptides (GIPs) in urine and blood serum spiked with Solgluten. Food-grade Solgluten was prepared by the extraction of a peptic digest of vital gluten with water, centrifugation, and freeze-drying. The process was relatively easy, repeatable, and cheap. The content of gliadin-derived GIPs was 491 mg/g. Solgluten was used as antigenic material to compare two competitive ELISA kits (R7021 and K3012) and two sandwich ELISA kits (M2114 and R7041) in their quality regarding the quantitation of GIPs in urine and blood serum. The quality parameters were the reactivity, sensitivity, coefficients of variation and determination, and curve shape. The evaluation of the kits showed a number of discrepancies in individual quality parameters measured in urine and serum. Due to the lowest limit of quantitation and the highest coefficient of determination, M2114 may be the first choice, while R7021 appeared to be less suitable because of the high coefficients of variation and unfavorable curve progression. The results set the stage for improving CD diagnosis by supplementing conventional blood tests with oral provocation with Solgluten and subsequent ELISA measurement of GIPs that could support the no-biopsy approach and by better assessing the effect of a gluten-free diet by monitoring adherence to the diet by measuring GIPs in urine and blood.


Assuntos
Doença Celíaca , Glutens , Humanos , Dieta Livre de Glúten , Ensaio de Imunoadsorção Enzimática/métodos , Peptídeos , Gliadina
9.
J Med Case Rep ; 18(1): 119, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38414080

RESUMO

BACKGROUND: In this case series, a perioperative anticoagulation protocol for microvascular head and neck surgery in patients with thrombophilia is presented. Microvascular free-flap surgery is a standard procedure in head and neck surgery with high success rates. Nevertheless, flap loss-which is most often caused by thrombosis-can occur and has far-reaching consequences, such as functional impairment, prolonged hospitalization, and increased costs. The risk of flap loss owing to thrombosis is significantly increased in patients with thrombophilia. Therefore, perioperative anticoagulation is mandatory. To date, no perioperative anticoagulation protocol exists for these high-risk patients. CASE PRESENTATION: We present three exemplary male Caucasian patients aged 53-57 years with free flap loss owing to an underlying, hidden thrombophilia. CONCLUSION: We present a modified anticoagulation protocol for microvascular surgery in these high-risk patients, enabling successful microsurgical reconstruction.


Assuntos
Retalhos de Tecido Biológico , Neoplasias de Cabeça e Pescoço , Trombofilia , Trombose , Humanos , Masculino , Anticoagulantes/uso terapêutico , Retalhos de Tecido Biológico/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/complicações , Neoplasias de Cabeça e Pescoço/cirurgia , Complicações Pós-Operatórias , Estudos Retrospectivos , Trombofilia/complicações , Trombofilia/tratamento farmacológico , Trombose/etiologia , Pessoa de Meia-Idade
10.
Nat Commun ; 15(1): 1251, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341437

RESUMO

Organismal functional strategies form a continuum from slow- to fast-growing organisms, in response to common drivers such as resource availability and disturbance. However, whether there is synchronisation of these strategies at the entire community level is unclear. Here, we combine trait data for >2800 above- and belowground taxa from 14 trophic guilds spanning a disturbance and resource availability gradient in German grasslands. The results indicate that most guilds consistently respond to these drivers through both direct and trophically mediated effects, resulting in a 'slow-fast' axis at the level of the entire community. Using 15 indicators of carbon and nutrient fluxes, biomass production and decomposition, we also show that fast trait communities are associated with faster rates of ecosystem functioning. These findings demonstrate that 'slow' and 'fast' strategies can be manifested at the level of whole communities, opening new avenues of ecosystem-level functional classification.


Assuntos
Biodiversidade , Ecossistema , Biomassa , Agricultura , Solo
11.
ACS Chem Biol ; 19(3): 696-706, 2024 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-38385342

RESUMO

The blue-light photoreceptor YtvA from Bacillus subtilis has an N-terminal flavin mononucleotide (FMN)-binding light-oxygen-voltage (LOV) domain that is fused to a C-terminal sulfate transporter and anti-σ factor antagonist (STAS) output domain. To interrogate the signal transduction pathway that leads to photoactivation, the STAS domain was replaced with a histidine kinase, so that photoexcitation of the flavin could be directly correlated with biological activity. N94, a conserved Asn that is hydrogen bonded to the FMN C2═O group, was replaced with Ala, Asp, and Ser residues to explore the role of this residue in triggering the structural dynamics that activate the output domain. Femtosecond to millisecond time-resolved multiple probe spectroscopy coupled with a fluorescence polarization assay revealed that the loss of the hydrogen bond between N94 and the C2═O group decoupled changes in the protein structure from photoexcitation. In addition, alterations in N94 also decreased the stability of the Cys-FMN adduct formed in the light-activated state by up to a factor of ∼25. Collectively, these studies shed light on the role of the hydrogen bonding network in the LOV ß-scaffold in signal transduction.


Assuntos
Proteínas de Bactérias , Fotorreceptores Microbianos , Proteínas de Bactérias/metabolismo , Análise Espectral , Fotorreceptores Microbianos/química , Bacillus subtilis/metabolismo , Mononucleotídeo de Flavina/metabolismo
12.
ChemistryOpen ; 13(7): e202300298, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38224205

RESUMO

High complex stability and longitudinal relaxivity of Gd-based contrast agents are important requirements for magnetic resonance imaging (MRI) because they ensure patient safety and contribute to measurement sensitivity. Charged and zwitterionic Gd3+-complexes of the well-known chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) provide an excellent basis for the development of safe and sensitive contrast agents. In this report, we describe the synthesis of DOTA-NOx, a DOTA derivative with four N-oxide functionalities via "click" functionalization of the tetraazide DOTAZA. The resulting complexes Gd-DOTA-NOx and Eu-DOTA-NOx are stable compounds in aqueous solution. NMR-spectroscopic characterization revealed a high excess of the twisted square antiprismatic (TSAP) coordination geometry over square antiprismatic (SAP). The longitudinal relaxivity of Gd-DOTA-NOx was found to be r1=7.7 mm-1 s-1 (1.41 T, 37 °C), an unusually high value for DOTA complexes of comparable weight. We attribute this high relaxivity to the steric influence and an ordering effect on outer sphere water molecules surrounding the complex generated by the strongly hydrated N-oxide groups. Moreover, Gd-DOTA-NOx was found to be stable against transchelation with high excess of EDTA (200 eq) over a period of 36 h, and it has a similar in vitro cell toxicity as clinically used DOTA-based GBCAs.


Assuntos
Meios de Contraste , Gadolínio , Compostos Heterocíclicos com 1 Anel , Imageamento por Ressonância Magnética , Compostos Heterocíclicos com 1 Anel/química , Gadolínio/química , Meios de Contraste/química , Humanos , Óxidos/química , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Quelantes/química , Quelantes/síntese química
13.
Talanta ; 271: 125598, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38224656

RESUMO

Almonds (Prunus dulcisMill.) are consumed worldwide and their geographical origin plays a crucial role in determining their market value. In the present study, a total of 250 almond reference samples from six countries (Australia, Spain, Iran, Italy, Morocco, and the USA) were non-polar extracted and analyzed by UPLC-ESI-IM-qToF-MS. Four harvest periods, more than 30 different varieties, including both sweet and bitter almonds, were considered in the method development. Principal component analysis showed that there are three groups of samples with similarities: Australia/USA, Spain/Italy and Iran/Morocco. For origin determination, a random forest achieved an accuracy of 88.8 %. Misclassifications occurred mainly between almonds from the USA and Australia, due to similar varieties and similar external influences such as climate conditions. Metabolites relevant for classification were selected using Surrogate Minimal Depth, with triacylglycerides containing oxidized, odd chained or short chained fatty acids and some phospholipids proven to be the most suitable marker substances. Our results show that focusing on the identified lipids (e. g., using a QqQ-MS instrument) is a promising approach to transfer the origin determination of almonds to routine analysis.


Assuntos
Prunus dulcis , Prunus , Espectrometria de Massas em Tandem/métodos , Espectrometria de Massa com Cromatografia Líquida , Cromatografia Líquida
14.
Int J Mol Sci ; 25(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38255921

RESUMO

5-Deazaflavins are analogs of naturally occurring flavin cofactors. They serve as substitutes for natural flavin cofactors to investigate and modify the reaction pathways of flavoproteins. Demethylated 5-deazaflavins are potential candidates for artificial cofactors, allowing us to fine-tune the reaction kinetics and absorption characteristics of flavoproteins. In this contribution, demethylated 5-deazariboflavin radicals are investigated (1) to assess the influence of the methyl groups on the electronic structure of the 5-deazaflavin radical and (2) to explore their photophysical properties with regard to their potential as artificial cofactors. We determined the proton hyperfine structure of demethylated 5-deazariboflavins using photochemically induced dynamic nuclear polarization (photo-CIDNP) spectroscopy, as well as density functional theory (DFT). To provide context, we compare our findings to a study of flavin mononucleotide (FMN) derivatives. We found a significant influence of the methylation pattern on the absorption properties, as well as on the proton hyperfine coupling ratios of the xylene moiety, which appears to be solvent-dependent. This effect is enhanced by the replacement of N5 by C5-H in 5-deazaflavin derivatives compared to their respective flavin counterparts.


Assuntos
Dinitrocresóis , Prótons , Riboflavina , Análise Espectral , Flavoproteínas
15.
J Cheminform ; 15(1): 114, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38012793

RESUMO

Prediction of chemical shift in NMR using machine learning methods is typically done with the maximum amount of data available to achieve the best results. In some cases, such large amounts of data are not available, e.g. for heteronuclei. We demonstrate a novel machine learning model that is able to achieve better results than other models for relevant datasets with comparatively low amounts of data. We show this by predicting [Formula: see text] and [Formula: see text] NMR chemical shifts of small molecules in specific solvents.

16.
J Agric Food Chem ; 71(46): 18074-18084, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37934755

RESUMO

The price of different truffle types varies according to their culinary value, sometimes by more than a factor of 10. Nonprofessionals can hardly distinguish visually the species within the white or black truffles, making the possibility of food fraud very easy. Therefore, the identification of different truffle species (Tuber spp.) is an analytical task that could be solved in this study. The polar extract from a total of 80 truffle samples was analyzed by 1H NMR spectroscopy in combination with chemometric methods covering five commercially relevant species. All classification models were validated applying a repeated nested cross-validation. In direct comparison, the two very similar looking and closely related black representatives Tuber melanosporum and Tuber indicum could be classified 100% correctly. The most expensive truffle Tuber magnatum could be distinguished 100% from the other relevant white truffle Tuber borchii. In addition, signals for a potential Tuber borchii and a potential Tuber melanosporum marker for targeted approaches could be detected, and the corresponding molecules were identified as betaine and ribonate. A model covering all five truffle species Tuber aestivum, Tuber borchii, Tuber indicum, Tuber magnatum, and Tuber melanosporum was able to correctly discriminate between each of the species.


Assuntos
Ascomicetos , Máquina de Vetores de Suporte , Ascomicetos/classificação
17.
Data Brief ; 51: 109677, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37965598

RESUMO

This dataset provides detailed chronostratigraphic and lithological maps of the entire Ahr River catchment, which is located in Western Germany. The geological information was acquired using a transfer of the German chronostratigraphic terms into the international stratigraphic notation. Information about the geology and lithology was provided by publicly sourced data released by the German federal states North Rhine-Westphalia and Rhineland-Palatinate. The dataset includes information about the international stratigraphy, the corresponding German unit, and the lithology in English and German. The dataset is essentially useful for catchment-scale research, for example with regard to the causes and consequences of the July 2021 flooding of the Ahr River.

18.
Sci Rep ; 13(1): 19663, 2023 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-37952061

RESUMO

Despite evidence from grasslands experiments suggesting that plant species loss reduces biomass production, the strength of biodiversity-ecosystem functioning relationships in managed grasslands is still debated. High land-use intensity and reduced species pools are often suggested to make relationships between biodiversity and productivity less positive or even negative, but concrete evidence is still scarce. We investigated biodiversity-productivity relationships over two years in 150 managed grasslands in Germany. Specifically, we distinguished between relationships of biodiversity and biomass production in managed grasslands (1) varying in land-use intensity (e.g. of mowing, grazing and/or fertilization), (2) where land-use intensity is experimentally reduced, and (3) where additionally to land-use reductions, species pools are enlarged by seed addition. Among grasslands varying in land-use intensity, we found negative biodiversity-productivity relationships. Land-use reduction weakened these relationships, towards neutral, and sometimes, even positive relationships. Seed addition reduced species pool limitations, but this did not strengthen biodiversity-productivity relationships. Our findings indicate that land-use intensity is an important factor explaining the predominantly negative biodiversity-productivity relationships in managed grasslands. While we did not find that species pool limitations weakened biodiversity-productivity relationships, our results are based on a two-year-old experiment, possibly such effects are only visible in the long-term. Ultimately, advancing insights on biodiversity-ecosystem functioning relationships helps us to understand under which conditions agricultural production may benefit from promoting biodiversity.


Assuntos
Ecossistema , Pradaria , Biomassa , Biodiversidade , Sementes
19.
Metabolites ; 13(10)2023 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-37887356

RESUMO

Accelerated storage is routinely used with pharmaceuticals to predict stability and degradation patterns over time. The aim of this is to assess the shelf life and quality under harsher conditions, providing crucial insights into their long-term stability and potential storage issues. This study explores the potential of transferring this approach to food matrices for shelf-life estimation. Therefore, hazelnuts were stored under accelerated short-term and realistic long-term conditions. Subsequently, they were analyzed with high resolution mass spectrometry, focusing on the lipid profile. LC-MS analysis has shown that many unique processes take place under accelerated conditions that do not occur or occur much more slowly under realistic conditions. This mainly involved the degradation of membrane lipids such as phospholipids, ceramides, and digalactosyldiacylglycerides, while oxidation processes occurred at different rates in both conditions. It can be concluded that a food matrix is far too complex and heterogeneous compared to pharmaceuticals, so that many more processes take place during accelerated storage, which is why the results cannot be used to predict molecular changes in hazelnuts stored under realistic conditions.

20.
Metabolites ; 13(10)2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37887402

RESUMO

The untargeted metabolomics analysis of biological samples with nuclear magnetic resonance (NMR) provides highly complex data containing various signals from different molecules. To use these data for classification, e.g., in the context of food authentication, machine learning methods are used. These methods are usually applied as a black box, which means that no information about the complex relationships between the variables and the outcome is obtained. In this study, we show that the random forest-based approach surrogate minimal depth (SMD) can be applied for a comprehensive analysis of class-specific differences by selecting relevant variables and analyzing their mutual impact on the classification model of different truffle species. SMD allows the assignment of variables from the same metabolites as well as the detection of interactions between different metabolites that can be attributed to known biological relationships.

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