Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 131
Filtrar
1.
Front Bioeng Biotechnol ; 12: 1349473, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38863496

RESUMO

Pharmaceutical manufacturing is reliant upon bioprocessing approaches to generate the range of therapeutic products that are available today. The high cost of production, susceptibility to process failure, and requirement to achieve consistent, high-quality product means that process monitoring is paramount during manufacturing. Process analytic technologies (PAT) are key to ensuring high quality product is produced at all stages of development. Spectroscopy-based technologies are well suited as PAT approaches as they are non-destructive and require minimum sample preparation. This study explored the use of a novel attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy platform, which utilises disposable internal reflection elements (IREs), as a method of upstream bioprocess monitoring. The platform was used to characterise organism health and to quantify cellular metabolites in growth media using quantification models to predict glucose and lactic acid levels both singularly and combined. Separation of the healthy and nutrient deficient cells within PC space was clearly apparent, indicating this technique could be used to characterise these classes. For the metabolite quantification, the binary models yielded R 2 values of 0.969 for glucose, 0.976 for lactic acid. When quantifying the metabolites in tandem using a multi-output partial least squares model, the corresponding R 2 value was 0.980. This initial study highlights the suitability of the platform for bioprocess monitoring and paves the way for future in-line developments.

2.
Polymers (Basel) ; 16(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891424

RESUMO

Resin matrix composites (RCs) have better thermal and chemical stability, so they are widely used in engineering fields. In this study, the aging process and mechanism of two different types of resin-based three-dimensional four-way braided composites (H15 and S15) under different hygrothermal aging conditions were studied. The effect of aging behavior on the mechanical properties of RCs was also studied. Three different aging conditions were studied: Case I, 40 °C Soak; Case II, 70 °C Soak; and Case III, 70 °C-85% relative humidity (RH). It was found that the hygroscopic behavior of RCs in the process of moisture-heat aging conforms to Fick's second law. Higher temperatures and humidity lead to higher water absorption. The equilibrium hygroscopic content of H15 was 1.46% (Case II), and that of S15 was 2.51% (Case II). FT-IR revealed the different hygroscopic mechanisms of H15 and S15 in terms of aging behavior. On the whole, the infiltration behavior of water molecules is mainly exhibited in the process of wet and thermal aging. At the same time, the effect of the aging process on resin matrices was observed using SEM. It was found that the aging process led to the formation of microchannels on the substrate surface of S15, and the formation of these channels was the main reason for the better moisture absorption and lower mechanical strength of S15. At the same time, this study further found that temperature and oxygen content are the core influences on post-aging strength. The LVI experiment also showed that the structural changes and deterioration effects occurring after aging reduced the strength of the studied material.

3.
Curr Res Struct Biol ; 7: 100138, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38707546

RESUMO

Eukaryotic proteins often feature long stretches of amino acids that lack a well-defined three-dimensional structure and are referred to as intrinsically disordered proteins (IDPs) or regions (IDRs). Although these proteins challenge conventional structure-function paradigms, they play vital roles in cellular processes. Recent progress in experimental techniques, such as NMR spectroscopy, single molecule FRET, high speed AFM and SAXS, have provided valuable insights into the biophysical basis of IDP function. This review discusses the advancements made in these techniques particularly for the study of disordered regions in proteins. In NMR spectroscopy new strategies such as 13C detection, non-uniform sampling, segmental isotope labeling, and rapid data acquisition methods address the challenges posed by spectral overcrowding and low stability of IDPs. The importance of various NMR parameters, including chemical shifts, hydrogen exchange rates, and relaxation measurements, to reveal transient secondary structures within IDRs and IDPs are presented. Given the high flexibility of IDPs, the review outlines NMR methods for assessing their dynamics at both fast (ps-ns) and slow (µs-ms) timescales. IDPs exert their functions through interactions with other molecules such as proteins, DNA, or RNA. NMR-based titration experiments yield insights into the thermodynamics and kinetics of these interactions. Detailed study of IDPs requires multiple experimental techniques, and thus, several methods are described for studying disordered proteins, highlighting their respective advantages and limitations. The potential for integrating these complementary techniques, each offering unique perspectives, is explored to achieve a comprehensive understanding of IDPs.

4.
J Pharm Sci ; 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38750935

RESUMO

Characterization and understanding of protein higher order structure (HOS) is essential at all stages of biologics development. Here, two folding variants of a bispecific monoclonal antibody, the correctly folded form and an alternative configuration with reduced potency, were characterized by several HOS characterization techniques. Specifically, differential scanning calorimetry (DSC), circular dichroism (CD), Fourier-transform infrared spectroscopy (FTIR), Raman and Raman optical activity (ROA) spectroscopy were used together to elucidate the impacts of disulfide bond scrambling in the fused scFv domains on the structure and thermal stability of the antibody. This study illustrates the importance of selecting appropriate biophysical characterization techniques based on the nature and magnitude of the HOS change.

5.
Food Res Int ; 186: 114381, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729735

RESUMO

Lipid has crucial applications in improving the quality of starchy products during heat processing. Herein, the influence of lipid modification and thermal treatment on the physicochemical properties and starch digestibility of cooked rice prepared with varied addition manipulations was investigated. Rice bran oil (RO) and medium chain triglyceride oil (MO) manipulations were performed either before (BC) or after cooking (AC). GC-MS was applied to determine the fatty acid profiles. Nutritional quality was analyzed by quantifying total phenolics, atherogenic, and thrombogenic indices. All complexes exhibited higher surface firmness, a soft core, and less adhesive. FTIR spectrum demonstrated that the guest component affected some of the dense structural attributes of V-amylose. The kinetic constant was in the range between 0.47 and 0.86 min-1 wherein before mode presented a higher value. The lowest glucose release was observed in the RO_BC sample, whereas the highest complexing index was observed in the RO_AC sample, indicating that the dense molecular configuration of complexes that could resist enzymatic digestion was more critical than the quantity of complex formation. Despite the damage caused by mass and heat transfer, physical barrier, intact granule forms, and strengthened dense structure were the central contributors affecting the digestion characteristics of lipid-starch complexes.


Assuntos
Culinária , Digestão , Oryza , Óleo de Farelo de Arroz , Amido , Triglicerídeos , Oryza/química , Amido/química , Óleo de Farelo de Arroz/química , Triglicerídeos/química , Temperatura Alta , Ácidos Graxos/análise , Ácidos Graxos/química , Óleos de Plantas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Valor Nutritivo , Amilose/química , Cromatografia Gasosa-Espectrometria de Massas
6.
Cureus ; 16(2): e53871, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38465103

RESUMO

Background Dental caries is the most common bacterial disease of calcified tissues of teeth. Cariogenic biofilms formed on the tooth surface secrete organic acids and thus result in demineralization. Delving into the depth of biofilms is crucial to understand the pathogenic mechanisms and design improved therapeutic approaches. The aim of the study is to analyze the spatial and biochemical characteristics of cariogenic biofilms. Materials and methods Pulp tissue samples sourced from freshly extracted third molars were incubated with oral cariogenic bacteria namely Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Entamoeba faecalis, and Candida albicans to form the biofilm. Spatial assessment of biofilms was done under FESEM (field emission scanning electron microscope, JSM-IT800, JEOL, Tokyo, Japan). FTIR (Fourier transform infrared spectroscopy, Alpha II, Bruker, Germany) spectra were assessed for chemical molecular interactions in 24- and 48-hour time periods.  Results Morphological assessment with FESEM revealed rapid growth and aggregation within a short time period. FTIR spectra to analyze chemical constituents of biofilm presented with varied peaks of water, amide A, amide I, water, lipids, and phospholipids. Conclusion Further validation with more advanced imaging for an extended time period is vital to derive better conclusive evidence.

7.
Biochem Biophys Res Commun ; 703: 149648, 2024 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-38368675

RESUMO

Our prior investigation has confirmed that the anti-hepatocellular carcinoma activity of the plant saponin, specifically Uttroside B (Utt-B), derived from the leaves of Solanum nigrum Linn. This study concentrated on formulating a novel biocompatible nanocarrier utilizing Extracellular vesicles (EVs) to enhance the delivery of plant saponin into cells. The physicochemical attributes of Extracellular Vesicles/UttrosideB (EVs/Utt-B) were comprehensively characterized through techniques such as Transmission Electron Microscopy (TEM) and Fourier-transform infrared spectroscopy (FTIR). Despite the promising therapeutic potential of this uttroside B, mechanistic know-how about its entry into cells is still in its infancy. Our research sheds light on the extracellular vesicle-mediated mechanism facilitating the entry of the saponin into cells, a phenomenon confirmed through the use of by confocal microscopy. We further analysed drug-releasing kinetics and simulated the Pharmacokinetics by PBPK modelling. The simulated pharmacokinetics revealed the bioavailability of Uttroside-B in oral administration against intravenous administration.


Assuntos
Carcinoma Hepatocelular , Vesículas Extracelulares , Neoplasias Hepáticas , Saponinas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Microscopia Eletrônica de Transmissão , Saponinas/uso terapêutico
8.
Anal Sci ; 40(4): 691-699, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38374487

RESUMO

Porphyromonas gingivalis, a Gram-negative anaerobic bacillus, is the primary pathogen in periodontitis. Herein, we cultivated strains of oral bacteria, including P. gingivalis and the oral commensal bacteria Actinomyces viscosus and Streptococcus mutans, and recorded the infrared absorption spectra of the gases released by the cultured bacteria at a resolution of 0.5 cm-1 within the wavenumber range of 500-7500 cm-1. From these spectra, we identified the infrared wavenumbers associated with characteristic absorptions in the gases released by P. gingivalis using a decision tree-based machine learning algorithm. Finally, we compared the obtained absorbance spectra of ammonia (NH3) and carbon monoxide (CO) using the HITRAN database. We observed peaks at similar positions in the P. gingivalis gases, NH3, and CO spectra. Our results suggest that P. gingivalis releases higher amounts of NH3 and CO than A. viscosus and S. mutans. Thus, combining Fourier transform infrared spectroscopy with machine learning enabled us to extract the specific wavenumber range that differentiates P. gingivalis from a vast dataset of peak intensity ratios. Our method distinguishes the gases from P. gingivalis from those of other oral bacteria and provides an effective strategy for identifying P. gingivalis in oral bacteria. Our proposed methodology could be valuable in clinical settings as a simple, noninvasive pathogen diagnosis technique.


Assuntos
Periodontite , Porphyromonas gingivalis , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier , Periodontite/microbiologia , Gases
9.
Spectrochim Acta A Mol Biomol Spectrosc ; 310: 123922, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38295589

RESUMO

The fruit of Crataegus sp. is known as "Shanzha (SZ)" in China and is widely used in the food, beverage, and traditional Chinese medicine (TCM) industries. SZ usually requires thermal processing to reduce the irritation of its acidity to the gastric mucosa. Different processed products of SZ resulting from thermal processing have different or even opposite functions in clinical applications. In addition, 5-hydroxymethylfurfural (5-HMF) intermediates produced during thermal processing are carcinogenic to humans. Therefore, the aim of this study was to explore a rapid and accurate method by Fourier transform infrared spectroscopy (FT-IR) for the identification of different processed products and the determination of 5-HMF in extracts. In qualitative identification, a three-stage infrared spectroscopy identification method (raw spectra, the second derivative spectra, and two-dimensional correlation (2DCOS) spectra) was developed to distinguish different processed products of SZ step by step. In quantitative determination, partial least squares regression combined with different variable selection methods, especially the 2DCOS method, was applied to determine the 5-HMF content. The results show that temperature-induced 2DCOS synchronous spectra can effectively identify different processed products of SZ by shape, intensity, and position of auto-peaks or cross-peaks, and the variables selected by power spectra from concentration-induced 2DCOS synchronous spectra have better prediction ability for 5-HMF compared to full variables. The above results demonstrate that 2D-COS analysis is a potential tool in qualitative and quantitative analysis, which can improve sample identification accuracy and determination capabilities. This study not only establishes a rapid and accurate method for the identification of different processed products but also provides a practical reference for food safety and the efficient use of TCM.


Assuntos
Crataegus , Frutas , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Espectrofotometria Infravermelho/métodos , Medicina Tradicional Chinesa
10.
J Appl Biomater Funct Mater ; 22: 22808000231222704, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38217423

RESUMO

OBJECTIVES: Silk fiber is difficult to degrade in vivo, which limits its application in tissue engineering materials such as artificial nerves. Therefore, in this study aim to promote its degradation in vivo by chemical treating silk fibers in vitro. MATERIALS AND METHODS: Sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), scanning electron microscopy (SEM) observations, mechanical test, Fourier transform infrared spectroscopy (FT-IR) measurements were used to investigate the degradation effect of chemicals (hydrochloric acid, phosphoric acid, acetic acid, sodium hydroxide, calcium hydroxide, sodium bicarbonate, and calcium chloride) on silk fiber in vitro. Immunofluorescence staining and transcriptome analysis were used to investigate the effect of inflammatory factors on the degradation of chemically treated silk fiber in rats. RESULTS: (1) Silks were separated into finer fibers in each group. (2) FT-IR absorption peaks of amides I, II, and III overlap in each group. (3) Silk degradation degree in each group was higher than that in an untreated group. The calcium chloride-treated group was completely degraded. (4) Fibronectin, collagen I, collagen III, integrin α and CD68 were immunofluorescence positive in all vegetation section. (5) There were no significant differences in the expressions of collagen I, collagen III, and fibronectin in the vegetations formed on the 14th day of subcutaneous implantation, while integrin α, CD68, TNF-α, IL-1b, and IL-23 express at higher levels with IL-10 at lower levels. CONCLUSIONS: All chemicals could completely degrade silk; however, their degradation products were not the same. The chemicals change the mechanical properties of silk by separating it into finer fibers, which increase the contact surface area between the silk and tissue fluid, accelerating the degradation of monofilaments in vivo by promoting inflammation and macrophage activity through the increased and decreased expressions of pro- and anti-inflammatory factors, respectively.


Assuntos
Fibroínas , Seda , Ratos , Animais , Seda/química , Fibronectinas , Fibroínas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Cloreto de Cálcio , Colágeno/química , Colágeno Tipo I , Integrinas
11.
Spectrochim Acta A Mol Biomol Spectrosc ; 309: 123820, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38168660

RESUMO

Urine is a very interesting and attractive biofluid for biomarker discovery and medical diagnosis research due to its non-invasiveness collection and richness of potential biomarkers. Fourier-Transform Infrared (FTIR) spectroscopy applied on urine samples is a promising tool that could be used as a screening method for various diseases. However, during method development, frozen urine is more accessible, especially for inter-laboratory studies, whereas in routine application fresh urine is more convenient. Here, the objective of our work is to evaluate the freezing impact on mid-infrared signature of urine samples. Therefore, both fresh and frozen urine samples from twenty patients were analysed in a dried form. These samples were collected from patients consulting for cystoscopy examination. Simultaneously, centrifugation was also conducted on 10 of all included patients. Principal component analysis (PCA) revealed that patient inter-variabilities are higher than variability due to the freezing step. Then, Euclidean distance between fresh and frozen urine of each patient highlighted that the impact of freezing is different from one patient to another. Adding the centrifugation step slightly minimized intra-patient variability compared to not centrifugated samples. This study contributes to define experimental conditions for urine analysis development for translational application in biomedical field.


Assuntos
Urologia , Humanos , Congelamento , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Biomarcadores/urina , Programas de Rastreamento
12.
Mar Drugs ; 21(12)2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-38132922

RESUMO

In this work, we extracted chitosan from marine amphipods associated with aquaculture facilities and tested its use in crop protection. The obtained chitosan was 2.5 ± 0.3% of initial ground amphipod dry weight. The chemical nature of chitosan from amphipod extracts was confirmed via Raman scattering spectroscopy and Fourier transform infrared spectroscopy (FTIR). This chitosan showed an 85.7-84.3% deacetylation degree. Chitosan from biofouling amphipods at 1 mg·mL-1 virtually arrested conidia germination (ca. sixfold reduction from controls) of the banana wilt pathogenic fungus Fusarium oxysporum f. sp cubense Tropical Race 4 (FocTR4). This concentration reduced (ca. twofold) the conidia germination of the biocontrol fungus Pochonia chlamydosporia (Pc123). Chitosan from amphipods at low concentrations (0.01 mg·mL-1) still reduced FocTR4 germination but did not affect Pc123. This is the first time that chitosan is obtained from biofouling amphipods. This new chitosan valorizes aquaculture residues and has potential for biomanaging the diseases of food security crops such as bananas.


Assuntos
Anfípodes , Quitosana , Fusarium , Musa , Animais , Musa/microbiologia , Quitosana/farmacologia , Doenças das Plantas/prevenção & controle , Doenças das Plantas/microbiologia , Fungos
13.
Int J Mol Sci ; 24(18)2023 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-37762603

RESUMO

The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (NixFe1-xOOH NPs) with a range of 'x' values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); 57Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer-Emmett-Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of NixFe1-xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)2 in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10-3 min-1. The 57Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s-1 and a hyperfine magnetic distribution (Bhf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10-10 to 5.30 × 10-12 (Ω cm)-1 with 'x' increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g-1, attributed to its largest specific surface area of 174.0 m2 g-1. In conclusion, NixFe1-xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries.


Assuntos
Minerais , Nanopartículas , Espectroscopia de Infravermelho com Transformada de Fourier , Eletrodos
14.
Plants (Basel) ; 12(16)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37631226

RESUMO

The main aim of this study is to find relevant analytic fingerprints for plants' structural characterization using spectroscopic techniques and thermogravimetric analyses (TGAs) as alternative methods, particularized on cabbage treated with selenium-baker's yeast vinasse formulation (Se-VF) included in a foliar fertilizer formula. The hypothesis investigated is that Se-VF will induce significant structural changes compared with the control, analytically confirming the biofortification of selenium-enriched cabbage as a nutritive vegetable, and particularly the plant biostimulant effects of the applied Se-VF formulation on cabbage grown in the field. The TGA evidenced a structural transformation of the molecular building blocks in the treated cabbage leaves. The ash residues increased after treatment, suggesting increased mineral accumulation in leaves. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) evidenced a pectin-Iα-cellulose structure of cabbage that correlated with each other in terms of leaf crystallinity. FTIR analysis suggested the accumulation of unesterified pectin and possibly (seleno) glucosinolates and an increased network of hydrogen bonds. The treatment with Se-VF formulation induced a significant increase in the soluble fibers of the inner leaves, accompanied by a decrease in the insoluble fibers. The ratio of soluble/insoluble fibers correlated with the crystallinity determined by XRD and with the FTIR data. The employed analytic techniques can find practical applications as fast methods in studies of the effects of new agrotechnical practices, while in our particular case study, they revealed effects specific to plant biostimulants of the Se-VF formulation treatment: enhanced mineral utilization and improved quality traits.

15.
Spectrochim Acta A Mol Biomol Spectrosc ; 303: 123228, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37579664

RESUMO

Despite the invaluable role of transition metals in every living organism, it should be remembered that failure to maintain the proper balance and exceed the appropriate dose may have the opposite effect. In the era of such a popular and propagated need for supplementation in the media, one should bear in mind the harmful effects that may become the result of improper and excessive intake of transition metals. This article establishes the feasibility of Raman (RS) and Fourier-transform infrared (FT-IR) spectroscopic imaging at the single-cell level to investigate the cellular response to various transition metals. These two non-destructive and perfectly complementary methods allow for in-depth monitoring of changes taking place within the cell under the influence of the agent used. HepG2 liver carcinoma cells were exposed to chromium, iron, cobalt, molybdenum, and nickel at 1 and 2 mM concentrations. Spectroscopic results were further supported by biological evaluation of selected caspases concentration. The caspase- 3, 6, 8, 9, and 12 concentrations were determined with the use of the enzyme-linked immunosorbent assay (ELISA) method. This study shows the induction of apoptosis in the intrinsic pathway by all studied transition metals. Cellular metabolism alterations are induced by mitochondrial metabolism changes and endoplasmic reticulum (ER) metabolism variations. Moreover, nickel induces not only the intrinsic pathway of apoptosis but also the extrinsic pathway of this process.


Assuntos
Carcinoma , Níquel , Humanos , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Apoptose , Fígado
16.
Nanomaterials (Basel) ; 13(13)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37446460

RESUMO

Research on the effects of engineered nanomaterials (ENMs) on mitochondria, which represent one of the main actors in cell function, highlighted effects on ROS production, gametogenesis and organellar genome replication. Specifically, the mitochondrial effects of cadmium sulfide quantum dots (CdS QDs) exposure can be observed through the variation in enzymatic kinetics at the level of the respiratory chain and also by analyzing modifications of reagent and products in term of the bonds created and disrupted during the reactions through Fourier-transform infrared spectroscopy (FTIR). This study investigated both in intact cells and in isolated mitochondria to observe the response to CdS QDs treatment at the level of electron transport chain in the wild-type yeast Saccharomyces cerevisiae and in the deletion mutant Δtom5, whose function is implicated in nucleo-mitochondrial protein trafficking. The changes observed in wild type and Δtom5 strains in terms of an increase or decrease in enzymatic activity (ranging between 1 and 2 folds) also differed according to the genetic background of the strains and the respiratory chain functionality during the CdS QDs treatment performed. Results were confirmed by FTIR, where a clear difference between the QD effects in the wild type and in the mutant strain, Δtom5, was observed. The utilization of these genetic and biochemical approaches is instrumental to clarify the mitochondrial mechanisms implicated in response to these types of ENMs and to the stress response that follows the exposure.

17.
Mar Pollut Bull ; 194(Pt B): 115268, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37451046

RESUMO

Malaysia is bounded by the South China Sea with many islands that support species megadiversity and coral reef ecosystems. This study investigates the distribution of microplastics (MPs) in the surface water around the four marine park islands (Perhentian, Redang, Kapas, and Tenggol) during COVID-19. The global pandemic has reset human activities, impacting the environment while possibly reducing anthropogenic contributions of microplastic pollution near the South China Sea islands. It was found that Pulau Perhentian recorded the most abundance of MPs (588.33 ± 111.77 items/L), followed by Pulau Redang (314.67 ± 58.08 items/L), Pulau Kapas (359.8 ± 87.70 items/L) and Pulau Tenggol (294.33 ± 101.64 items/L). Kruskal-Wallis analysis indicates a significant difference in total MPs abundance between islands. There are moderate correlations between salinity, pH, temperature and MPs variability. Among these parameters, only temperature is significant (p < 0.05) as proven by the principal component analysis and multiple linear regression analysis. Nearly 99 % of MPs are fiber type, with the majority of them being black and transparent. Micro-FTIR spectroscopy revealed polyethylene, polypropylene, polyvinyl methyl ether, polyamide, phenoxy-resins and polyurethane-acrylic are associated with MPs. The findings provide a new baseline reference for the MPs distribution on Malaysian islands, which contributes to a potential future direction regarding marine sustainability.


Assuntos
COVID-19 , Poluentes Químicos da Água , Humanos , Microplásticos , Plásticos , Ecossistema , Água , Ilhas , Poluentes Químicos da Água/análise , Monitoramento Ambiental , COVID-19/epidemiologia , China
18.
Int J Mol Sci ; 24(12)2023 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-37373418

RESUMO

Tendon injuries can result in two major drawbacks. Adhesions to the surrounding tissue may limit the range of motion, while fibrovascular scar formation can lead to poor biomechanical outcomes. Prosthetic devices may help to mitigate those problems. Emulsion electrospinning was used to develop a novel three-layer tube based on the polymer DegraPol (DP), with incorporated insulin-like growth factor-1 (IGF-1) in the middle layer. Scanning electron microscopy was utilized to assess the fiber diameter in IGF-1 containing pure DP meshes. Further characterization was performed with Fourier Transformed Infrared Spectroscopy, Differential Scanning Calorimetry, and water contact angle, as well as through the assessment of mechanical properties and release kinetics from ELISA, and the bioactivity of IGF-1 by qPCR of collagen I, ki67, and tenomodulin in rabbit Achilles tenocytes. The IGF-1-containing tubes exhibited a sustained release of the growth factor up to 4 days and showed bioactivity by significantly upregulated ki67 and tenomodulin gene expression. Moreover, they proved to be mechanically superior to pure DP tubes (significantly higher fracture strain, failure stress, and elastic modulus). The novel three-layer tubes intended to be applied over conventionally sutured tendons after a rupture may help accelerate the healing process. The release of IGF-1 stimulates proliferation and matrix synthesis of cells at the repair site. In addition, adhesion formation to surrounding tissue can be reduced due to the physical barrier.


Assuntos
Tendão do Calcâneo , Traumatismos dos Tendões , Animais , Coelhos , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/farmacologia , Fator de Crescimento Insulin-Like I/metabolismo , Emulsões/metabolismo , Antígeno Ki-67/metabolismo , Traumatismos dos Tendões/tratamento farmacológico , Traumatismos dos Tendões/metabolismo , Tendão do Calcâneo/metabolismo
19.
J Photochem Photobiol B ; 245: 112734, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37295134

RESUMO

Essential thrombocythemia (ET) reflects the transformation of a multipotent hematopoietic stem cell, but its molecular pathogenesis remains obscure. Nevertheless, tyrosine kinase, especially Janus kinase 2 (JAK2), has been implicated in myeloproliferative disorders other than chronic myeloid leukaemia. FTIR analysis was performed on the blood serum of 86 patients and 45 healthy volunteers as control with FTIR spectra-based machine learning methods and chemometrics. Thus, the study aimed to determine biomolecular changes and separation of ET and healthy control groups illustration by applying chemometrics and ML techniques to spectral data. The FTIR-based results showed that in ET disease with JAK2 mutation, there are alterations in functional groups associated with lipids, proteins and nucleic acids significantly. Moreover, in ET patients the lower amount of proteins with simultaneously higher amount of lipids was noted in comparison with the control one. Furthermore, the SVM-DA model showed 100% accuracy in calibration sets in both spectral regions and 100.0% and 96.43% accuracy in prediction sets for the 800-1800 cm-1 and 2700-3000 cm-1 spectral regions, respectively. While changes in the dynamic spectra showed that CH2 bending, amide II and CO vibrations could be used as a spectroscopy marker of ET. Finally, it was found a positive correlation between FTIR peaks and first bone marrow fibrosis degree, as well as the absence of JAK2 V617F mutation. The findings of this study contribute to a better understanding of the molecular pathogenesis of ET and identifying biomolecular changes and may have implications for early diagnosis and treatment of this disease.


Assuntos
Policitemia Vera , Trombocitemia Essencial , Humanos , Trombocitemia Essencial/diagnóstico , Trombocitemia Essencial/genética , Trombocitemia Essencial/patologia , Policitemia Vera/diagnóstico , Policitemia Vera/genética , Espectroscopia de Infravermelho com Transformada de Fourier , Patologia Molecular , Soro
20.
Small ; 19(41): e2304108, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37317013

RESUMO

Transition metal-nitrogen-carbon materials with atomically dispersed active sites are promising catalysts for oxygen evolution reaction (OER) since they combine the strengths of both homogeneous and heterogeneous catalysts. However, the canonically symmetric active site usually exhibits poor OER intrinsic activity due to its excessively strong or weak oxygen species adsorption. Here, a catalyst with asymmetric MN4 sites based on the 3-s-triazine of g-C3 N4 (termed as a-MN4 @NC) is proposed. Compared to symmetric, the asymmetric active sites directly modulate the oxygen species adsorption via unifying planar and axial orbitals (dx2 -y2 , dz2 ), thus enabling higher OER intrinsic activity. In Silico screening suggested that cobalt has the best OER activity among familiar nonprecious transition metal. These experimental results suggest that the intrinsic activity of asymmetric active sites (179 mV overpotential at onset potential) is enhanced by 48.4% compared to symmetric under similar conditions. Remarkably, a-CoN4 @NC showed excellent activity in alkaline water electrolyzer (AWE) device as OER catalyst, the electrolyzer only required 1.7 V and 2.1 V respectively to reach the current density of 150 mA cm-2 and 500 mA cm-2 . This work opens an avenue for modulating the active sites to obtain high intrinsic electrocatalytic performance including, but not limited to, OER.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...