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1.
Toxicol Res (Camb) ; 13(4): tfae126, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-39132191

RESUMEN

Background: Synthetic food dyes are being exponentially used in food products and scarce studies regarding their toxicities and safety raise concern. Erythrosine is one of the synthetic food dyes being used in jams, fig, pineapple marmalades, dairy products, soft drinks, pickles, relishes, smoked fish, cheese, ketchup, maraschino cherries and a variety of other foods. Methodology: In this study the cyto-genotoxic effect of erythrosine was evaluated, using root meristematic cells of Allium cepa for the cellular and molecular alternations at concentrations 0.1, 0.25, 0.5 and 1 mg/mL. Results: The results revealed a significant decrease of 57.81% in the mitotic index after 96 h at the 0.1 mg/mL concentration. In biochemical analysis, the malondialdehyde content increased significantly (5.47-fold), while proline content, catalase activity and superoxide dismutase activity decreased gradually in a concentration-dependent manner showing a maximum decrease of 78.11%, 64.68% and 61.73% respectively at the highest concentration after 96 h duration. The comet assay revealed increased DNA damage with increasing concentration and attenuated total reflectance- Fourier transform infrared spectroscopy (ATR-FTIR) analysis showed significant alterations in biomolecules as indicated by multivariate analysis, i.e. Principal Component Analysis (PCA). Furthermore, molecular docking demonstrated a strong binding energy (Gbest = -11.46 kcal/mol) and an inhibition constant (Ki) of 3.96 nM between erythrosine and the DNA minor groove. Conclusion: The present study's findings revealed the cytotoxic and genotoxic potential of erythrosine on A. cepa root cells. Further, the study also proposed the usefulness of A. cepa as a model system for studying the toxicity of food additives.

2.
J Int Soc Prev Community Dent ; 14(1): 16-27, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38559637

RESUMEN

Aim: To enhance mineral trioxide aggregate high plasticity (MTA HP), a commonly used dental calcium silicate cement, by incorporating selenium nanoparticles (SeNPs) known for their antioxidant and anti-inflammatory properties. The objectives included investigating the impact of SeNPs on the setting time and chemical properties of MTA HP. Materials and Methods: We performed a comprehensive study to formulate and profile SeNPs integrated into MTA HP. Diverse concentrations of SeNPs were introduced into MTA HP, and the commencement and culmination of the setting process were gauged employing a Gillmore needle cabinet. The chemical composition was validated using Fourier transform infrared spectroscopy with attenuated total reflectance and X-ray diffraction analysis. Results: The incorporation of SeNPs led to remarkable improvements. Notably, SeNPs positively affected the setting time of MTA HP, with faster setting times corresponding to higher SeNPs concentrations. Chemical analyses confirmed the successful integration of SeNPs with MTA HP. These enhancements make the material may be suitable for dental applications, especially due to its accelerated setting time. Conclusions: MTA HP incorporated with SeNPs represents a significant advancement in dental materials. Its faster setting time, combined with the antioxidant and anti-inflammatory properties of selenium, provides dental professionals with an efficient and time-saving option for complex treatments. This novel nanomaterial holds promise for improving dental procedures and patient outcomes.

3.
Spectrochim Acta A Mol Biomol Spectrosc ; 313: 124142, 2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38493515

RESUMEN

In this work, we investigated the oxidative stress-related biochemical alterations in red blood cells (RBCs) and their membranes with the use of spectroscopic techniques. We aimed to show their great advantage for the in situ detection of lipid classes and secondary structures of proteins without the need for their extraction in the cellular environment. The exposition of the cells to peroxides, t-butyl hydroperoxide (tBOOH) or hydrogen peroxide (H2O2) led to different degradation processes encompassing the changes in the composition of membranes and structural modifications of hemoglobin (Hb). Our results indicated that tBOOH is generally a stronger oxidizing agent than H2O2 and this observation was congruent with the activity of superoxide and glutathione peroxidase. ATR-FTIR and Raman spectroscopies of membranes revealed that tBOOH caused primarily the partial loss and peroxidation of the lipids resulting in loss of the integrity of membranes. In turn, both peroxides induced several kinds of damage in the protein layer, including the partial decrease of their content and irreversible aggregation of spectrin, ankyrin, and membrane-bound globin. These changes were especially pronounced on the membrane surface where stress conditions induced the formation of ß-sheets and intramolecular aggregates, particularly for tBOOH. Interestingly, nano-FTIR spectroscopy revealed the lipid peroxidative damage on the membrane surface in both cases. As far as hemoglobin was concerned, tBOOH and H2O2 caused the increase of the oxyhemoglobin species and conformational alterations of its polypeptide chain into ß-sheets. Our findings confirm that applied spectroscopies effectively track the oxidative changes occurring in the structural components of red blood cells and the simplicity of conducting measurements and sample preparation can be readily applied to pharmacological and clinical studies.


Asunto(s)
Eritrocitos , Peróxido de Hidrógeno , Humanos , Peróxido de Hidrógeno/farmacología , Peróxido de Hidrógeno/metabolismo , Eritrocitos/metabolismo , Hemoglobinas/metabolismo , Peróxidos/farmacología , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Lípidos , Estrés Oxidativo
4.
Biosensors (Basel) ; 14(1)2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38248411

RESUMEN

Pap smear screening is a widespread technique used to detect premalignant lesions of cervical cancer (CC); however, it lacks sensitivity, leading to identifying biomarkers that improve early diagnosis sensitivity. A characteristic of cancer is the aberrant sialylation that involves the abnormal expression of α2,6 sialic acid, a specific carbohydrate linked to glycoproteins and glycolipids on the cell surface, which has been reported in premalignant CC lesions. This work aimed to develop a method to differentiate CC cell lines and primary fibroblasts using a novel lectin-based biosensor to detect α2,6 sialic acid based on attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and chemometric. The biosensor was developed by conjugating gold nanoparticles (AuNPs) with 5 µg of Sambucus nigra (SNA) lectin as the biorecognition element. Sialic acid detection was associated with the signal amplification in the 1500-1350 cm-1 region observed by the surface-enhanced infrared absorption spectroscopy (SEIRA) effect from ATR-FTIR results. This region was further analyzed for the clustering of samples by applying principal component analysis (PCA) and confidence ellipses at a 95% interval. This work demonstrates the feasibility of employing SNA biosensors to discriminate between tumoral and non-tumoral cells, that have the potential for the early detection of premalignant lesions of CC.


Asunto(s)
Nanopartículas del Metal , Lectinas de Plantas , Proteínas Inactivadoras de Ribosomas , Sambucus nigra , Neoplasias del Cuello Uterino , Femenino , Humanos , Neoplasias del Cuello Uterino/diagnóstico , Lectinas , Ácido N-Acetilneuramínico , Oro , Línea Celular
5.
J Clin Microbiol ; 62(2): e0121123, 2024 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-38284762

RESUMEN

The reliability of Fourier-transform infrared (FT-IR) spectroscopy for Klebsiella pneumoniae typing and outbreak control has been previously assessed, but issues remain in standardization and reproducibility. We developed and validated a reproducible FT-IR with attenuated total reflectance (ATR) workflow for the identification of K. pneumoniae lineages. We used 293 isolates representing multidrug-resistant K. pneumoniae lineages causing outbreaks worldwide (2002-2021) to train a random forest classification (RF) model based on capsular (KL)-type discrimination. This model was validated with 280 contemporaneous isolates (2021-2022), using wzi sequencing and whole-genome sequencing as references. Repeatability and reproducibility were tested in different culture media and instruments throughout time. Our RF model allowed the classification of 33 capsular (KL)-types and up to 36 clinically relevant K. pneumoniae lineages based on the discrimination of specific KL- and O-type combinations. We obtained high rates of accuracy (89%), sensitivity (88%), and specificity (92%), including from cultures obtained directly from the clinical sample, allowing to obtain typing information the same day bacteria are identified. The workflow was reproducible in different instruments throughout time (>98% correct predictions). Direct colony application, spectral acquisition, and automated KL prediction through Clover MS Data analysis software allow a short time-to-result (5 min/isolate). We demonstrated that FT-IR ATR spectroscopy provides meaningful, reproducible, and accurate information at a very early stage (as soon as bacterial identification) to support infection control and public health surveillance. The high robustness together with automated and flexible workflows for data analysis provide opportunities to consolidate real-time applications at a global level. IMPORTANCE We created and validated an automated and simple workflow for the identification of clinically relevant Klebsiella pneumoniae lineages by FT-IR spectroscopy and machine-learning, a method that can be extremely useful to provide quick and reliable typing information to support real-time decisions of outbreak management and infection control. This method and workflow is of interest to support clinical microbiology diagnostics and to aid public health surveillance.


Asunto(s)
Bacterias , Klebsiella pneumoniae , Humanos , Klebsiella pneumoniae/genética , Reproducibilidad de los Resultados , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Secuenciación Completa del Genoma , Proteínas de la Ataxia Telangiectasia Mutada
6.
Foods ; 13(2)2024 Jan 12.
Artículo en Inglés | MEDLINE | ID: mdl-38254546

RESUMEN

A spectroscopic investigation of beeswax adulteration by paraffin and/or stearic acid was undertaken via Attenuated Total Reflectance Infra-Red spectroscopy (ATR-IR) combined with multivariate statistical analyses. Principal Component Analysis (PCA) was successfully applied for the first time as an exploratory tool for the differentiation among pure beeswax and adulterated beeswax by paraffin and stearic acid with detection limits (LOD) of ~5% and 1%, respectively. Partial Least Square (PLS) modelling was used to build chemometric models based on beeswax/paraffin and beeswax/stearic acid calibration mixtures and subsequently used to predict concentrations of paraffin and stearic acid on a set of unknown test samples. PLS predictions demonstrated that beeswax adulteration by paraffin is much more prominent (74%) than the one by stearic acid (26%) and that commercial beeswax products (candles, pearls, blocks, etc.) are more prone to adulteration (27%) than honeycomb-type samples (12.5%).

7.
Environ Sci Technol ; 58(1): 362-370, 2024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38151228

RESUMEN

One possible carbon dioxide sequestration strategy is via the carbonation of dissolved Mg2+ obtained through olivine ((Mg,Fe)2SiO4) dissolution. However, silica is also produced during the breakdown of olivine. This component may have a detrimental effect on the yield of Mg-carbonate as Mg2+ incorporation into complex Mg silicate phases would limit CO2 uptake by this system. Yet this potential competition is currently not considered. Here, we use crystal growth experiments at temperatures applicable for potential coastal applications to test the effect of silica on the formation of the hydrated Mg-carbonate phase nesquehonite (MgCO3·3H2O). Solution chemistry analysis coupled with phase identification demonstrates that the presence of silica in the solution can actually assist the formation of nesquehonite and increase its yield by as much as 60 times. Our findings suggest that the presence of silica changes interfacial stabilities, lowering the energetic barrier for nesquehonite nucleation. In addition, in situ attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) transformation experiments demonstrated that nesquehonite precipitating in a solution containing a high concentration of dissolved silica exhibits enhanced stability against its transformation into hydromagnesite. These findings will help to better constrain what we expect for applications of olivine during carbon remediation strategies as well as assist yields for industrial applications that use Mg-based cement as building materials to facilitate a CO2-neutral or negative footprint.


Asunto(s)
Magnesio , Dióxido de Silicio , Magnesio/química , Carbonatos , Dióxido de Carbono/química
8.
J Appl Crystallogr ; 56(Pt 5): 1522-1527, 2023 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-37791361

RESUMEN

Small-angle neutron scattering (SANS) is widely used as a powerful technique to study the higher-order structure of soft matter. To increase the reliability of SANS profile analysis for complex multi-component systems, combining different types of structural information obtained by other methods is desirable. A simultaneous measurement system combining SANS and Fourier transform infrared (FTIR) spectroscopy meets this objective. It is beneficial for targets where matching the timing of structural changes between experiments is difficult, but the issue is that samples suitable for SANS are too thick for the typical transmission FTIR method. To overcome this problem, a new simultaneous measurement system that employs the attenuated total reflectance (ART) sampling method for FTIR spectroscopy has been developed.

9.
Bioengineering (Basel) ; 10(9)2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37760120

RESUMEN

Bone analyses using mid-infrared spectroscopy are gaining popularity, especially with handheld spectrometers that enable on-site testing as long as the data quality meets standards. In order to diagnose Staphylococcus epidermidis in human bone grafts, this study was carried out to compare the effectiveness of the Agilent 4300 Handheld Fourier-transform infrared with the Perkin Elmer Spectrum 100 attenuated-total-reflectance infrared spectroscopy benchtop instrument. The study analyzed 40 non-infected and 10 infected human bone samples with Staphylococcus epidermidis, collecting reflectance data between 650 cm-1 and 4000 cm-1, with a spectral resolution of 2 cm-1 (Agilent 4300 Handheld) and 0.5 cm-1 (Perkin Elmer Spectrum 100). The acquired spectral information was used for spectral and unsupervised classification, such as a principal component analysis. Both methods yielded significant results when using the recommended settings and data analysis strategies, detecting a loss in bone quality due to the infection. MIR spectroscopy provides a valuable diagnostic tool when there is a tissue shortage and time is of the essence. However, it is essential to conduct further research with larger sample sizes to verify its pros and cons thoroughly.

10.
J Forensic Sci ; 68(6): 1906-1912, 2023 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-37593942

RESUMEN

The last few years have witnessed the change in the modalities of smuggling of synthetic cannabinoid receptor agonists (SCRAs) by impregnating them in mail envelopes and fast parcels. Considering the aforementioned scenario, it is important to develop a portable technique to identifying SCRAs through packages. The purpose of this research was to detect SCRAs impregnated into substrates of paper using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Three SCRAs that included 5F-PB-22, AB-FUBINACA and AKB-48 were purchased from Sigma Aldrich. The three SCRAs and four cutting agents were impregnated into paper of variable thickness at four concentrations (10, 15, 20, and 25 mg/mL). Spectra were collected over the wavenumber range of 650-4000 cm-1 using ATR-FTIR spectroscopy and were exported to Matlab 2020b where data analysis was applied. The FTIR spectral data was able to show the three SCRAs could be detected on paper using ATR-FTIR spectroscopy and quantitatively modeled using the partial least squares regression algorithm. Principal component analysis showed separate clustering for the compounds that crystallized (5F-PB-22, AB-FUBINACA and caffeine) onto the papers surface from those impregnated into the bulk of the paper (AKB-48 and procaine) with the latter situated near blank papers in score plots. In summary, ATR-FTIR spectroscopy has proven to be a successful non-destructive technique in detecting and quantifying a selection of SCRAs impregnated into paper.


Asunto(s)
Adamantano , Agonistas de Receptores de Cannabinoides , Agonistas de Receptores de Cannabinoides/análisis , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Indazoles
11.
Polymers (Basel) ; 15(13)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37447546

RESUMEN

The characterization and quantification of functional groups in technical lignins are among the chief obstacles of the utilization of this highly abundant biopolymer. Although several techniques were developed for this purpose, there is still a need for quick, cost-efficient, and reliable quantification methods for lignin. In this paper, three sampling techniques for fourier transform infrared (FTIR) spectroscopy were assessed both qualitatively and quantitatively, delineating how these affected the resultant spectra. The attenuated total reflectance (ATR) of neat powders and DMSO-d6 solutions, as well as transmission FTIR using the KBr pelleting method (0.5 wt%), were investigated and compared for eight lignin samples. The ATR of neat lignins provided a quick and easy method, but the signal-to-noise ratios in the afforded spectra were limited. The ATR of the DMSO-d6 solutions was highly concentration dependent, but at a 30 wt%, acceptable signal-to-noise ratios were obtained, allowing for the lignins to be studied in the dissolved state. The KBr pelleting method gave a significant improvement in the smoothness and resolution of the resultant spectra compared to the ATR techniques. Subsequently, the content of phenolic OH groups was calculated from each FTIR mode, and the best correlation was seen between the transmission mode using KBr pellets and the ATR of the neat samples (R2 = 0.9995). Using the titration measurements, the total OH and the phenolic OH group content of the lignin samples were determined as well. These results were then compared to the FTIR results, which revealed an under-estimation of the phenolic OH groups from the non-aqueous potentiometric titration, which was likely due to the differences in the pKa between the lignin and the calibration standard 4-hydroxybenzoic acid. Further, a clear correlation was found between the lower Mn and the increased phenolic OH group content via SEC analyses. The work outlined in this paper give complementary views on the characterization and quantification of technical lignin samples via FTIR.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 302: 123031, 2023 Dec 05.
Artículo en Inglés | MEDLINE | ID: mdl-37392540

RESUMEN

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) difference spectroscopy has been employed for a variety of applications spanning from reaction mechanisms analysis to interface phenomena assessment. This technique is based on the detection of spectral changes induced by the chemical modification of the original sample. In the present study, we highlight the potential of the ATR-FTIR difference approach in the field of microbial biochemistry and biotechnology, reporting on the identification of main soluble species consumed and released by growing bacteria during the biohydrogen production process. Specifically, the mid-infrared spectrum of a model culture broth, composed of glucose, malt extract and yeast extract, was used as background to acquire the FTIR difference spectrum of the same broth as modified by Enterobacter aerogenes metabolism. The analysis of difference signals revealed that only glucose is degraded during hydrogen evolution in anaerobic conditions, while ethanol and 2,3-butanediol are the main soluble metabolites released with H2. This fast and easy analytical approach can therefore represent a sustainable strategy to screen different bacterial strains and to select raw and waste materials to be employed in the field of biofuel production.


Asunto(s)
Biocombustibles , Biotecnología , Espectroscopía Infrarroja por Transformada de Fourier/métodos
13.
Antioxidants (Basel) ; 12(6)2023 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-37371914

RESUMEN

Coffee is one of the most widely consumed beverages worldwide due to its sensory and potential health-related properties. In the present comparative study, a preparation known as Greek or Turkish coffee, made with different types/varieties of coffee, has been investigated for its physicochemical attributes (i.e., color), antioxidant/antiradical properties, phytochemical profile, and potential biological activities by combining high-throughput analytical techniques, such as infrared spectroscopy (ATR-FTIR), liquid chromatography-tandem mass spectrometry (LC-MS/MS), and in silico methodologies. The results of the current study revealed that roasting degree emerged as the most critical factor affecting these parameters. In particular, the L* color parameter and total phenolic content were higher in light-roasted coffees, while decaffeinated coffees contained more phenolics. The ATR-FTIR pinpointed caffeine, chlorogenic acid, diterpenes, and quinic esters as characteristic compounds in the studied coffees, while the LC-MS/MS analysis elucidated various tentative phytochemicals (i.e., phenolic acids, diterpenes, hydroxycinnamate, and fatty acids derivatives). Among them, chlorogenic and coumaric acids showed promising activity against human acetylcholinesterase and alpha-glucosidase enzymes based on molecular docking studies. Therefore, the outcomes of the current study provide a comprehensive overview of this kind of coffee preparation in terms of color parameters, antioxidant, antiradical and phytochemical profiling, as well as its putative bioactivity.

14.
R Soc Open Sci ; 10(6): 230059, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37293355

RESUMEN

Book production by medieval scriptoria have gained growing interest in recent studies. In this context, identifying ink compositions and parchment animal species from illuminated manuscripts is of great importance. Here, we introduce time-of-flight secondary ion mass spectrometry (ToF-SIMS) as a non-invasive tool to identify both inks and animal skins in manuscripts, at the same time. For this purpose, both positive and negative ion spectra in inked and non-inked areas were recorded. Chemical compositions of pigments (decoration) or black inks (text) were determined by searching for characteristic ion mass peaks. Animal skins were identified by data processing of raw ToF-SIMS spectra using principal component analysis (PCA). In illuminated manuscripts from the fifteenth to sixteenth century, malachite (green), azurite (blue), cinnabar (red) inorganic pigments, as well as iron-gall black ink, were identified. Carbon black and indigo (blue) organic pigments were also identified. Animal skins were identified in modern parchments of known animal species by a two-step PCA procedure. We believe the proposed method will find extensive application in material studies of medieval manuscripts, as it is non-invasive, highly sensitive and able to identify both inks and animal skins at the same time, even from traces of pigments and tiny scanned areas.

15.
Int J Mol Sci ; 24(7)2023 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-37047712

RESUMEN

Traditional renal biomarkers such as serum creatinine and albuminuria/proteinuria are rather insensitive since they change later in the course of the disease. In order to determine the extent and type of kidney injury, as well as to administer the proper therapy and enhance patient management, new techniques for the detection of deterioration of the kidney function are urgently needed. Infrared spectroscopy is a label-free and non-destructive technique having the potential to be a vital tool for quick and inexpensive routine clinical diagnosis of kidney disorders. The aim of this review is to provide an overview of near- and mid-infrared spectroscopy applications in patients with acute kidney injury and chronic kidney disease (e.g., diabetic nephropathy and glomerulonephritis).


Asunto(s)
Nefropatías Diabéticas , Glomerulonefritis , Humanos , Riñón/diagnóstico por imagen , Glomerulonefritis/diagnóstico , Espectrofotometría Infrarroja , Proteinuria
16.
Heliyon ; 9(3): e14281, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36925532

RESUMEN

Itraconazole (ICZ) is a broad spectrum antifungal drug, but used as second or third line therapy due to its low and erratic oral bioavailability. This work was carried out to prepare and characterize matrix type lipid-polymer hybrid nanoparticles (LPHNPs) for dissolution enhancement of ICZ. LPHNPs were prepared using solvent diffusion/emulsification technique. Matrix LPHNPs were composed of chitosan (polymer), glyceryl monostearate (lipid) and poloxamer 188 (stabilizer). LPHNPs loaded with ICZ (LPHNPs-1, LPHNPs-2, LPHNPs-3 and LPHNPs-4) were developed using varying concentration of chitosan whereas LPHNPs (LPHNPs-5, LPHNPs-6, LPHNPs-7 and LPHNPs-8) were prepared using varying concentrations of poloxamer 188. LPHNPs loaded with ICZ were further evaluated for entrapment efficiency, particle size, polydispersity index (PDI), zeta potential and dissolution profiles at biorelevant pH conditions. The particle size (LPHNPs-1 to LPHNPs-4) was found to be in range of 421-588 nm with PDI values 0.34-0.41. The particles size of LPHNPs-5 to LPHNPs-8 was found to be in range of 489-725 nm with PDI 0.34-0.74. The entrapment efficiency of LPHNPs-1 to LPHNPs-4 was found to be in range of 85.21%-91.34%. The entrapment efficiency of LPHNPs-5 to LPHNPs-8 was found to be in range 78.32%-90.44%. . The scanning electron microscopy of optimized formulations LPHNPs-1 and LPHNPs-5 indicated formation of oval shaped nanoparticles. DSC thermogram of ICZ loaded LPHNPs also depicted the conversion of crystalline form of ICZ into amorphous form demonstrating the internalization and dissolution enhancement of drug in the hybrid matrix. The cumulative drug dissolved at acidic pH 1.2 was found to be 23.3% and 19.8% for LPHNPs-1 and LPHNPs-5 respectively. Similarly at basic pH values 7.4, cumulative amount of drug dissolved was 90.2% and 83.4% for LPHNPs-1 and LPHNPs-5 respectively. Drug dissolution kinetics exhibited fickian diffusion best described by Korse-meyer Peppas model. The results suggested that chitosan and glyceryl monostearate based matrix LPHNPs could be used as promising approach for dissolution enhancement of ICZ which could further increase its bioavailability.

17.
Materials (Basel) ; 16(3)2023 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-36769997

RESUMEN

Attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy was used to demonstrate the reaction mechanisms of alkali-activated materials (AAMs) and the early stage of structure formation in the materials. The effects of different types of alkali activator solutions on the structure formation and reaction mechanisms of AAMs were studied. The results revealed that the main peaks of the ATR-FTIR spectra of the AAMs in the 1300-650 cm-1 range shifted to a low wavenumber with changing patterns, depending on the activator solution used, indicating that the dissolution and reorientation of metakaolin had occurred. Silica and alumina monomers were dissolved by the NaOH solution to produce crystalline zeolites. Although the reaction between metakaolin and Na2SiO3 solution is slow, the condensation between the Al-OH from metakaolin and the Si-OH from Na2SiO3 solution bonded the chain to be longer. Therefore, the Na2SiO3 solution acted as a template-bonded monomer, formed long chains of Si-O-Si and Si-O-Al, and produced an amorphous AAM structure. In the mixed solution, when the NaOH in it dissolved the Si and Al monomers, the Na2SiO3 in the solution also bonded with monomers and produced a complex structure. The different reaction that metakaolin had with different alkali activator solutions reflected the different phases, microstructures, and mechanical properties of the AAMs produced.

18.
Polymers (Basel) ; 15(3)2023 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-36771825

RESUMEN

Celluloid artifacts are known by conservation professionals to be prone to degradation, threatening their own integrity and that of nearby heritage collections. Celluloid alteration can have a heterogeneous nature, and this research topic is still in its infancy for heritage science. This article investigates degradation gradients, both along depth and width, of artificially aged celluloid sheets, and compares them to three-dimensional (3D) historical objects with the aim of gaining a better insight into the nature and evolution of their decay. ATR-FTIR was used to systematically study different sampling points of the artificially and naturally aged specimens and allowed us to recognize better-preserved surfaces and more deteriorated cores. ATR-FTIR was found suitable for assessing the molecular changes induced by degradation, particularly denitration and formation of carbonyl-containing degradation products in severely aged specimens. Even though the severely artificially aged sheets displayed unusual alteration phenomena, they present a degradation gradient similar to the one observed for the naturally aged 3D objects under study. This research underlines that sampling at different depths and/or widths is relevant for characterizing the heterogeneity of degraded celluloid, and further investigation with chromatographic techniques would greatly benefit the understanding of the complex degradation of celluloid artifacts.

19.
Talanta ; 253: 123961, 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36215751

RESUMEN

The adulteration of honey (Apis mellifera) is a global problem due to its economic, commercial and health implications. The world's leading beekeeping organisation, APIMONDIA, considers that the detection of adulteration in honey is a problem that has not yet been resolved. This evidence of the importance of the intensive development of analytical techniques that allow the unequivocal detection of adulterants in honey, especially those whose use as honey adulterants has recently emerged. This work aims to develop a fast, easy-to-perform, low-cost analytical method to qualitatively and quantitatively determine rice syrup using the Fourier transform infrared spectroscopy (FTIR) technique with attenuated total reflectance (ATR) mode without complex mathematical procedures and sophisticated sample preparation. This study involved the analysis of 256 intentionally rice-syrup-adulterated honey samples and 92 pure honey samples of bee multifloral honey from Spain. The method, based strictly on the determination of the absorbance directly from the samples, at 1013 cm-1 The methodology used no need for previous treatments or preparations and demonstrated the scope for the unequivocal detection of rice syrup in adulterated honey containing equal to or higher than 3% (m/m) or more of this adulterant. Using the Exponential Plus Linear model (r = 0.998) shows high accuracy and precision, in terms of relative error (0.32%, m/m) and coefficient of variation (1.4%). The results of this study have led to the establishment of a maximum absorbance threshold of 0.670 for honey without rice syrup.


Asunto(s)
Oryza , Abejas , Animales , Espectroscopía Infrarroja por Transformada de Fourier , España
20.
Molecules ; 27(17)2022 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-36080384

RESUMEN

In the present work, the applicability of attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, coupled with chemometric tools in recognizing essential oils (EOs) for routine control, was evaluated. EOs belonging to Mentha, Cymbopogon, and Lavandula families and to S. rosmarinus and T. vulgaris species were analyzed, and the performance of several untargeted approaches, based on the synergistic combination of ATR-FTIR and Partial Least Squares Discriminant Analysis (PLS-DA), was tested to classify the species and chemotypes. Different spectra pre-processing methods were employed, and the robustness of the built models was tested by means of a Receiver Operating Characteristic (ROC) curve and random permutations test. The application of these approaches revealed fruitful results in terms of sensitivity and specificity, highlighting the potentiality of ATR-FTIR and chemometrics techniques to be used as a sensitive, cost-effective, and rapid tool to differentiate EO samples according to their species and chemotype.


Asunto(s)
Quimiometría , Aceites Volátiles , Espectroscopía Infrarroja por Transformada de Fourier , Humanos , Aceites Volátiles/química , Aceites Volátiles/clasificación , Reproducibilidad de los Resultados , Espectroscopía Infrarroja por Transformada de Fourier/métodos
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