Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32.609
Filtrar
1.
Food Res Int ; 189: 114495, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38876585

RESUMO

The texture of tomato products can be modified by choice of variety, their growing conditions and/or processing method, but no clear explanation exists of the mechanisms that transform fruit tissue, how they act on texture, or whether genetics and processing impact the same physical parameters. We therefore conducted a study that processed 4 varieties produced under low/high nitrogen supply, into puree using both hot and cold break processes. No specific rheological signature allows discrimination between cultivar-induced or process-induced textural changes, but that they can be distinguished by sensory analysis. Growth conditions impacted but was not sensory distinguished. Both caused significant variations in 7 of 11 physico-chemical parameters, but the order of importance of these traits controlling texture varied, depending on whether the cause was genetic or process-related. Analysis of alcohol insoluble solids revealed a specific signature in pectin composition and conformation that could be linked to particle aggregation in the presence of lycopene-rich particles.


Assuntos
Manipulação de Alimentos , Frutas , Reologia , Solanum lycopersicum , Solanum lycopersicum/química , Viscosidade , Manipulação de Alimentos/métodos , Frutas/química , Pectinas/química , Licopeno/análise , Paladar , Carotenoides/análise , Carotenoides/química , Humanos
2.
Food Res Int ; 189: 114533, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38876603

RESUMO

Glutinous rice is extensively consumed due to its nutritious content and wonderful flavor. However, glutinous rice flour has a high glycemic index, and the storage deterioration of sweet dumplingsissevere. Transglutaminase (TG) was used to cross-link glutinous rice protein and improve the characteristics of glutinous rice products. The findings demonstrated that TG significantly catalysed protein cross-linking to form a dense protein network, reduced the viscosity of glutinous rice paste and improved the thermal stability. The protein network may physically block the access of starch granules to digestive enzymes to lower the digestion rate of starch, and attenuate the damage of ice crystal molecules to the starch structure to improve the freezing stability of starch gels. The cracking rate and water loss of sweet dumplings prepared using glutinous rice flour with TG treated for 60 min reduced significantly. In conclusion, this study broadened the application of TG in starch products.


Assuntos
Digestão , Farinha , Manipulação de Alimentos , Oryza , Amido , Transglutaminases , Oryza/química , Transglutaminases/metabolismo , Amido/metabolismo , Amido/química , Farinha/análise , Manipulação de Alimentos/métodos , Viscosidade , Proteínas de Plantas/metabolismo , Proteínas de Plantas/química
3.
Reprod Domest Anim ; 59(6): e14637, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38864674

RESUMO

A variety of parameters, including liquefaction and semen viscosity, affect the sperm's ability to travel and reach the egg for fertilization and conception. Given that the details behind the viscosity of the semen in male camels have not yet been fully clarified, the purpose of this study was to ascertain how the addition of papain affected the viscosity of fresh diluted camel semen. The study examined semen samples derived from camels that had distinct viscosities. Sperm motility, viability, abnormal sperm percentage, concentration, viscosity, morphometry, acrosome integrity and liquefaction were among the evaluations following 0, 5, 10, 20 or 30 min of incubation at 37°C with papain (0.004 mg/mL, 0.04 mg/mL or 0.4 mg/mL; a semen sample without papain was used as a control). A statistically significant interaction between the effects of papain concentrations and incubation time was found (F = 41.68, p = .0001). Papain concentrations (p = .0001) and incubation times (p = .0001) both had a statistically significant impact on viscosity, according to a simple main effects analysis. A lower viscosity was found (p < .05) at 0.04 mg/mL (0.1 ± 0.0) after 10 min of incubation. A simple main effects analysis showed that papain concentrations and incubation time have a statistically significant effect on sperm motility (p = .0001). At 0.04 mg/mL papain, the sperm motility % was higher (p < .05) after 10 min (64.4 ± 4.8), 20 min (68.4 ± 6.2), and 30 min incubation (72.2 ± 6.6) compared to 0, 5 min (38.3 ± 4.1 and 51.6 ± 5.0, respectively). In conclusion, the fresh diluted camel semen had the lowest viscosity properties after 10 min of incubation with 0.04 mg/mL papain, without compromising sperm motility, viability, acrosome integrity and sperm morphology.


Assuntos
Camelus , Papaína , Preservação do Sêmen , Sêmen , Motilidade dos Espermatozoides , Animais , Papaína/farmacologia , Masculino , Viscosidade , Motilidade dos Espermatozoides/efeitos dos fármacos , Sêmen/efeitos dos fármacos , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Análise do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Acrossomo/efeitos dos fármacos
4.
Int J Biol Macromol ; 272(Pt 1): 132894, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38844285

RESUMO

Physicochemical and structural characteristics of chitosan prepared from Deep-sea shrimp (DCs), including degree of deacetylation (DD), molecular weight (Mw), viscosity, crystallinity index (CrI) and surface morphology were compared with a commercial chitosan (CCs). The DCs had a higher DD of 81.33 ± 0.40 %, whereas the CCs had a lower DD of 74.62 ± 0.64 %. Additionally, the DCs exhibited a lower Mw of 192.47 ± 2.5 kDa and viscosity of 646.00 ± 4.00 cP compared to the CCs, which had a Mw of 202.44 ± 0.28 kDa and viscosity of 689.67 ± 5.91 cP. This study investigated the influence of chitosan properties, particularly DD and Mw on the harvesting of Scenedesmus sp. along with the chitosan dosage, pH of the culture medium, mixing speed and time. Under optimal operating conditions, the microalgae removal efficiency of the DCs reached a significantly higher level (94.71 ± 0.20 %) compared to that of CCs (88.25 ± 0.41 %). Chitosan with a higher DD and low Mw demonstrated superior flocculation efficiency. The results highlight the significance of DD and Mw of chitosan and its influence on the flocculation of microalgae, providing valuable insights for optimizing the harvesting process with the non-toxic and natural flocculent, chitosan.


Assuntos
Quitosana , Floculação , Microalgas , Scenedesmus , Quitosana/química , Floculação/efeitos dos fármacos , Microalgas/crescimento & desenvolvimento , Viscosidade , Concentração de Íons de Hidrogênio , Peso Molecular , Animais
5.
Sci Rep ; 14(1): 13273, 2024 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-38858470

RESUMO

In this study, we conducted a numerical analysis on catheter sizes using computational fluid dynamics to assess urinary flow rates during intermittent catheterization (IC). The results revealed that the fluid (urine) movement within a catheter is driven by intravesical pressure, with friction against the catheter walls being the main hindrance to fluid movement. Higher-viscosity fluids experienced increased friction with increasing intravesical pressure, resulting in reduced fluid velocity, whereas lower-viscosity fluids experienced reduced friction under similar pressure, leading to increased fluid velocity. Regarding urine characteristics, the results indicated that bacteriuria, with lower viscosity, exhibited higher flow rates, whereas glucosuria exhibited the lowest flow rates. Additionally, velocity gradients decreased with increasing catheter diameters, reducing friction and enhancing fluid speed, while the friction increased with decreasing diameters, reducing fluid velocity. These findings confirm that flow rates increased with larger catheter sizes. Furthermore, in terms of specific gravity, the results showed that a 12Fr catheter did not meet the ISO-suggested average flow rate (50 cc/min). The significance of this study lies in its application of fluid dynamics to nursing, examining urinary flow characteristics in catheterization. It is expected to aid nurses in selecting appropriate catheters for intermittent catheterization based on urinary test results.


Assuntos
Hidrodinâmica , Humanos , Cateteres Urinários , Viscosidade , Cateterismo Urinário/instrumentação , Cateterismo Urinário/métodos , Urina/química , Catéteres , Fricção
6.
Commun Biol ; 7(1): 683, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38834871

RESUMO

In the context of soft matter and cellular mechanics, microrheology - the use of micron-sized particles to probe the frequency-dependent viscoelastic response of materials - is widely used to shed light onto the mechanics and dynamics of molecular structures. Here we present the implementation of active microrheology in an Acoustic Force Spectroscopy setup (AFMR), which combines multiplexing with the possibility of probing a wide range of forces ( ~ pN to ~nN) and frequencies (0.01-100 Hz). To demonstrate the potential of this approach, we perform active microrheology on biological samples of increasing complexity and stiffness: collagen gels, red blood cells (RBCs), and human fibroblasts, spanning a viscoelastic modulus range of five orders of magnitude. We show that AFMR can successfully quantify viscoelastic properties by probing many beads with high single-particle precision and reproducibility. Finally, we demonstrate that AFMR to map local sample heterogeneities as well as detect cellular responses to drugs.


Assuntos
Elasticidade , Eritrócitos , Fibroblastos , Reologia , Humanos , Viscosidade , Fibroblastos/fisiologia , Reologia/métodos , Colágeno/química , Acústica
7.
Sci Rep ; 14(1): 13038, 2024 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844503

RESUMO

This study aimed to develop an assessment framework for evaluating the quality of different chicken soup variants. Three types of chicken soup, traditional chicken soup (TCS), concentrated chicken soup (CCS), and blended chicken soup (BCS), were prepared and analyzed for various physicochemical parameters, including gross protein content, crude fat content, pH level, solid content, viscosity, and chromatic aberration value. Sensory evaluation was also conducted to assess overall quality. Correlation analysis helped identify three key evaluation indicators: gross protein content, L* value (lightness), and b* value (chromatic aberration). The weight assigned to gross protein content was the highest using the entropy weight method (EWM). Moreover, the grey correlation degree method was comprehensively applied to evaluate the chicken soup's quality. This analysis identified TCS and CCS as varieties with superior overall quality, showing a positive correlation with sensory evaluation, consistent with the results of nuclear magnetic resonance (NMR) used in this paper. These results provide theoretical support for assessing comprehensive quality and selecting chicken soup varieties.


Assuntos
Galinhas , Entropia , Animais , Qualidade dos Alimentos , Viscosidade , Concentração de Íons de Hidrogênio
8.
Sci Rep ; 14(1): 12756, 2024 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-38830930

RESUMO

Caenorhabditis elegans is an appealing tool for experimental evolution and for working with antiparasitic drugs, from understanding the molecular mechanisms of drug action and resistance to uncover new drug targets. We present a new methodology for studying the impact of antiparasitic drugs in C. elegans. Viscous medium was initially designed for C. elegans maintenance during long-term evolution experiments. Viscous medium provides a less structured environment than the standard nematode growth media agar, yet the bacteria food source remains suspended. Further, the Viscous medium offers the worm population enough support to move freely, mate, and reproduce at a rate comparable to standard agar cultures. Here, the Viscous medium was adapted for use in antiparasitic research. We observed a similar sensitivity of C. elegans to anthelmintic drugs as in standard liquid media and statistical difference to the standard agar media through a larval development assay. Using Viscous medium in C. elegans studies will considerably improve antiparasitic resistance research, and this medium could be used in studies aimed at understanding long-term multigenerational drug activity.


Assuntos
Anti-Helmínticos , Caenorhabditis elegans , Meios de Cultura , Caenorhabditis elegans/efeitos dos fármacos , Caenorhabditis elegans/crescimento & desenvolvimento , Animais , Anti-Helmínticos/farmacologia , Meios de Cultura/química , Viscosidade , Ágar , Resistência a Medicamentos/efeitos dos fármacos , Larva/efeitos dos fármacos
9.
Pediatr Dent ; 46(3): 204-208, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38822497

RESUMO

Purpose: The purpose of this study was to investigate the microleakage of atraumatic glass ionomer restorations with and without silver diammine fluoride (SDF) application. Restorations with SDF are termed silver-modified atraumatic restorations (SMART). Methods: Sixty carious extracted permanent teeth were randomly allocated to two SMART groups and two control groups (n equals 15 per group) for a total of four groups. After selective caries removal, test specimens were treated with 38 percent SDF and polyacrylic acid conditioner was applied and rinsed; teeth were restored with Fuji IX GP® glass ionomer (n equals 15) or with SMART Advantage™ glass ionomer (SAGI; n equals 15). For control groups, specimens were restored with their respective GI material after selective caries removal, both without SDF. Restored teeth were placed in Dulbecco's Phosphate-Buffered Saline solution at 37 degrees Celsius for 24 hours. Teeth were thermocycled between five and 55 degrees Celsius for 1,000 cycles, stained with two percent basic fuchsin, sectioned, and visually inspected for microleakage utilizing stereomicroscopy on a four-point scale. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance on ranks using Dunn's method (P<0.05). Results: Microleakage between the two SMART restoration groups was insignificant. SAGI alone demonstrated significantly more microleakage than all other groups. There was no statistical significance between the Fuji IX GP® control group and the two SMART restoration groups. Conclusions: This in vitro study indicated that silver diammine fluoride placed before glass ionomer restoration does not increase microleakage. Polyacrylic acid may be used after SDF placement without increasing microleakage.


Assuntos
Tratamento Dentário Restaurador sem Trauma , Cárie Dentária , Infiltração Dentária , Fluoretos Tópicos , Cimentos de Ionômeros de Vidro , Compostos de Prata , Infiltração Dentária/prevenção & controle , Humanos , Compostos de Prata/química , Cimentos de Ionômeros de Vidro/química , Tratamento Dentário Restaurador sem Trauma/métodos , Fluoretos Tópicos/química , Cárie Dentária/prevenção & controle , Cariostáticos/química , Compostos de Amônio Quaternário/química , Viscosidade , Resinas Acrílicas/química , Restauração Dentária Permanente/métodos
10.
Food Res Int ; 188: 114453, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823833

RESUMO

In this study, whipped cream with blends of micellar casein (MCN) and whey protein (WPI) in different ratios were prepared to investigate the role of protein interfacial behavior in determining foam properties at multiple scales, using theoretical modeling, and microscopic and macroscopic analysis. Fluid force microscopy has been used for the first time as a more realistic and direct means of analyzing interfaces properties in multiphase systems. The adsorption kinetics showed that the interfacial permeability constant of WPI (4.24 × 10-4 s-1) was significantly higher than that of the MCN (2.97 × 10-4 s-1), and the WPI interfacial layer had a higher modulus of elasticity (71.38 mN/m) than that of the MCN (47.89 mN/m). This model was validated via the mechanical analysis of the fat globules in real emulsions. The WPI-stabilized fat globule was found to have a higher Young's modulus (219.67 Pa), which contributes to the integrity of its fat globule morphology. As the ratio of MCN was increased in the sample, however, both the interfacial modulus and Young's modulus decreased. Moreover, the rate of partial coalescence was found to increase, a phenomenon that decreased the stability of the emulsion and increased the rate of aeration. The mechanical analysis also revealed a higher level of adhesion between MCN-stabilized fat globule (25.16 nN), which increased fat globule aggregation and emulsion viscosity, while improving thixotropic recovery. The synergistic effect of the blended MCN and WPI provided the highest overrun, at 194.53 %. These studies elucidate the role of the interfacial behavior of proteins in determining the quality of whipped cream and provide ideas for the application of proteins in multiphase systems.


Assuntos
Caseínas , Micelas , Proteínas do Soro do Leite , Proteínas do Soro do Leite/química , Caseínas/química , Emulsões/química , Laticínios , Gotículas Lipídicas/química , Adsorção , Cinética , Permeabilidade , Manipulação de Alimentos/métodos , Glicolipídeos/química , Módulo de Elasticidade , Viscosidade , Glicoproteínas
11.
Food Res Int ; 188: 114531, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823850

RESUMO

Different emulsion gel systems are widely applied to deliver functional ingredients. The effects and mechanisms of ultrasound-assisted emulsification (UAE) treatment and carboxymethyl cellulose (CMC) modifying the curcumin delivery properties and in vitro digestibility of the myofibrillar protein (MP)-soybean oil emulsion gels were investigated. The rheological properties, droplet size, protein and CMC distribution, ultrastructure, surface hydrophobicity, sulfhydryl groups, and zeta potential of emulsion gels were also measured. Results indicate that UAE treatment and CMC addition both improved curcumin encapsulation and protection efficiency in MP emulsion gel, especially for the UAE combined with CMC (UAE-CMC) treatment which encapsulation efficiency, protection efficiency, the release rate, and bioaccessibility of curcumin increased from 86.75 % to 97.67 %, 44.85 % to 68.85 %, 18.44 % to 41.78 %, and 28.68 % to 44.93 % respectively. The protein digestibility during the gastric stage was decreased after the CMC addition and UAE treatment, and the protein digestibility during the intestinal stage was reduced after the CMC addition. The fatty acid release rate was increased after CMC addition and UAE treatment. Apparent viscosity, storage modulus, and loss modulus were decreased after CMC addition while increased after UAE and UAE-CMC treatment especially the storage modulus increased from 0.26 Pa to 41 Pa after UAE-CMC treatment. The oil size was decreased, the protein and CMC concentration around the oil was increased, and a denser and uniform emulsion gel network structure was formed after UAE treatment. The surface hydrophobicity, free SH groups, and absolute zeta potential were increased after UAE treatment. The UAE-CMC treatment could strengthen the MP emulsion gel structure and decrease the oil size to increase the curcumin delivery properties, and hydrophobic and electrostatic interaction might be essential forces to maintain the emulsion gel.


Assuntos
Carboximetilcelulose Sódica , Curcumina , Digestão , Emulsões , Géis , Interações Hidrofóbicas e Hidrofílicas , Reologia , Curcumina/química , Emulsões/química , Carboximetilcelulose Sódica/química , Géis/química , Proteínas Musculares , Óleo de Soja/química , Viscosidade , Tamanho da Partícula , Miofibrilas/química , Miofibrilas/metabolismo , Ondas Ultrassônicas
12.
Food Res Int ; 188: 114511, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823884

RESUMO

This study investigated the relationship between rheological properties, sensory perception, and overall acceptability in healthy young and old groups for dysphagia thickened liquids. Unflavored (UTL) and flavored (FTLP) thickened liquids were prepared using tap water or pomegranate juice at 10 different viscosity levels. The rheological properties were then evaluated via syringe flow test and line spread test (LST). When the apparent viscosity levels of UTL and FTLP were similar, the syringe test and LST results were also similar, indicating consistent flow behavior. Sensory perception evaluations showed that the young group better distinguished viscosity differences between stages compared to the old group. Regarding overall acceptability, the old group preferred samples with higher apparent viscosity than the young group. Principal component analysis and k-means cluster analysis were used to explore correlations between variables and classify thickened liquids into four groups. This can serve the foundation for standardized texture grades of dysphagia thickened liquids, considering rheological characteristics and sensory profiles.


Assuntos
Transtornos de Deglutição , Reologia , Humanos , Viscosidade , Adulto Jovem , Feminino , Masculino , Adulto , Idoso , Paladar , Percepção Gustatória , Pessoa de Meia-Idade , Bebidas , Sucos de Frutas e Vegetais , Análise de Componente Principal , Voluntários Saudáveis
13.
Carbohydr Polym ; 339: 122268, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823931

RESUMO

The influence of locust bean gum (LBG) galactomannans (GMs) molecular weight (Mw) to assemble microparticulate systems was evaluated, and carriers for deep lung delivery were developed. A commercial batch of LBG with a mannose/galactose (M/G) ratio of 2.4 (batch 1) was used to study the influence of different microwave partial acid hydrolysis conditions on carbohydrate composition, glycosidic linkages, and aqueous solutions viscosity. The microwave treatment did not affect the composition, presenting 4-Man (36-42 %), 4,6-Man (27-35 %), and T-Gal (24-25 %) as the main glycosidic linkages. Depolymerization led to a viscosity reduction (≤0.005 Pa·s) with no major impact on polysaccharide debranching. The structural composition of the LBG galactomannans were further elucidated with sequence-specific proteins using carbohydrate microarray technologies. A second batch of LBG (M/G 3.3) was used to study the impact of GMs with different Mw on microparticle assembling, characteristics, and insulin release kinetics. The low-Mw GMs microparticles led to a faster release (20 min) than the higher-Mw (40 min) ones, impacting the release kinetics. All microparticles exhibited a safety profile to cells of the respiratory tract. However, only the higher-Mw GMs allowed the assembly of microparticles with sizes suitable for this type of administration.


Assuntos
Galactose , Mananas , Peso Molecular , Gomas Vegetais , Mananas/química , Galactose/química , Galactose/análogos & derivados , Gomas Vegetais/química , Humanos , Pulmão/metabolismo , Portadores de Fármacos/química , Tamanho da Partícula , Viscosidade , Insulina/química , Insulina/administração & dosagem , Liberação Controlada de Fármacos , Galactanos/química , Manose/química , Animais
14.
Carbohydr Polym ; 339: 122264, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823928

RESUMO

Normal rice starch consists of amylopectin and amylose, whose relative amounts and chain-length distributions (CLDs) are major determinants of the digestibility and rheology of cooked rice, and are related to metabolic health and consumer preference. Here, the mechanism of how molecular structural features of pure amylopectin (waxy) starches affect starch properties was explored. Following debranching, chain-length distributions of seven waxy varieties were measured using size-exclusion chromatography, and parameterized using biosynthesis-based models, which involve breaking up the chain-length distribution into contributions from five enzyme sets covering overlapping ranges of chain length; structure-property correlations involving the fifth set were found to be statistically significant. Digestibility was measured in vitro, and parameters for the slower and longer digestion phase quantified using non-linear least-squares fitting. The coefficient for the significant correlation involving amylopectin fine structure for the fifth set was -0.903, while the amounts of amylopectin short and long chains were found to dominate breakdown viscosity (correlation coefficients 0.801 and - 0.911, respectively). This provides a methodology for finding or developing healthier starch in terms of lower digestion rate, while also having acceptable palatability. As rice breeders can to some extent control CLDs, this can help the development of waxy rices with improved properties.


Assuntos
Amilopectina , Amilose , Oryza , Oryza/química , Amilopectina/química , Viscosidade , Amilose/química , Amilose/análise , Amido/química , Digestão , Reologia
15.
Carbohydr Polym ; 339: 122292, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823937

RESUMO

Through adaptive laboratory evolution (ALE) of Sphingomonas sp. ATCC 31555, fermentation for production of low-molecular-weight welan gum (LMW-WG) was performed using glycerol as sole carbon source. During ALE, GPC-MALS analysis revealed a gradual decrease in WG molecular weight with the increase of adaptation cycles, accompanied by changes in solution conformation. LMW-WG was purified and structurally analyzed using GPC-MALS, monosaccharide composition analysis, infrared spectroscopy, NMR analysis, atomic force microscopy, and scanning electron microscopy. Subsequently, LMW-WG obtains hydration, transparency, antioxidant activity, and rheological properties. Finally, an in vitro simulation colon reactor was used to evaluate potential prebiotic properties of LMW-WG as dietary fiber. Compared with WG produced using sucrose as substrate, LMW-WG exhibited a fourfold reduction in molecular weight while maintaining moderate viscosity. Structurally, L-Rha nearly completely replaced L-Man. Furthermore, LMW-WG demonstrated excellent hydration, antioxidant activity, and high transparency. It also exhibited resistance to saliva and gastrointestinal digestion, showcasing a favorable colonization effect on Bifidobacterium, making it a promising symbiotic agent.


Assuntos
Antioxidantes , Fermentação , Glicerol , Peso Molecular , Sphingomonas , Glicerol/química , Glicerol/metabolismo , Antioxidantes/química , Antioxidantes/farmacologia , Sphingomonas/metabolismo , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/farmacologia , Viscosidade , Prebióticos , Bifidobacterium/metabolismo
16.
Sci Rep ; 14(1): 13972, 2024 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-38886452

RESUMO

In the context of tissue engineering, biofabrication techniques are employed to process cells in hydrogel-based matrices, known as bioinks, into complex 3D structures. The aim is the production of functional tissue models or even entire organs. The regenerative production of biological tissues adheres to a multitude of criteria that ultimately determine the maturation of a functional tissue. These criteria are of biological nature, such as the biomimetic spatial positioning of different cell types within a physiologically and mechanically suitable matrix, which enables tissue maturation. Furthermore, the processing, a combination of technical procedures and biological materials, has proven highly challenging since cells are sensitive to stress, for example from shear and tensile forces, which may affect their vitality. On the other hand, high resolutions are pursued to create optimal conditions for subsequent tissue maturation. From an analytical perspective, it is prudent to first investigate the printing behavior of bioinks before undertaking complex biological tests. According to our findings, conventional shear rheological tests are insufficient to fully characterize the printing behavior of a bioink. For this reason, we have developed optical methods that, complementarily to the already developed tests, allow for quantification of printing quality and further viscoelastic modeling of bioinks.


Assuntos
Bioimpressão , Hidrogéis , Impressão Tridimensional , Engenharia Tecidual , Bioimpressão/métodos , Engenharia Tecidual/métodos , Hidrogéis/química , Reologia , Humanos , Alicerces Teciduais/química , Viscosidade
17.
Int J Mol Sci ; 25(11)2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38891855

RESUMO

Melatonin influences arterial biomechanics, and its absence could cause remodeling of the arterial wall, leading to increased stiffness. Direct effects of fentanyl on the aortic wall have also been observed previously. This study aimed to evaluate in vitro the effects of fentanyl on aortic viscoelasticity in a rat model of melatonin deficiency and to test the hypothesis that melatonin deficiency leads to increased arterial wall stiffness. The viscoelasticity was estimated in strip preparations from pinealectomized (pin, melatonin deficiency) and sham-operated (sham, normal melatonin) adult rats using the forced oscillations method. In the untreated aortic wall pin, the viscoelasticity was not significantly altered. However, combined with 10-9 M fentanyl, the pin increased the natural frequency (f0) and modulus of elasticity (E') compared to the sham-operated. Independently, fentanyl treatment decreased f0 and E' compared separately to untreated sham and pin preparations. The effects of fentanyl were neither dose-dependent nor affected by naloxone, suggesting a non-opioid mechanism. Furthermore, an independent effect of naloxone was also detected in the normal rat aortic wall, resulting in reduced E'. Additional studies are needed that may improve the clinical decisions for pain management and anesthesia for certain patients with co-occurring chronic low levels of blood plasma melatonin and some diseases.


Assuntos
Aorta , Elasticidade , Fentanila , Melatonina , Animais , Fentanila/farmacologia , Melatonina/farmacologia , Ratos , Masculino , Aorta/efeitos dos fármacos , Aorta/metabolismo , Elasticidade/efeitos dos fármacos , Viscosidade , Modelos Animais de Doenças , Rigidez Vascular/efeitos dos fármacos , Analgésicos Opioides/farmacologia , Naloxona/farmacologia
18.
J Texture Stud ; 55(3): e12846, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38899530

RESUMO

Around the world, the market for plant-derived beverages is one of the fastest-expanding segments in the functional and specialty beverage areas of newer food product development. Consumers are increasingly likely to choose alternatives to bovine beverages due to factors including lactose intolerance, hypercholesterolemia prevalence, allergies to bovine beverages, and preference for vegan diets that contain functionally active ingredients with health-promoting characteristics. Due to health, ecological, and ethical concerns, many customers are interested in reducing their usage of animal products like bovine milk. A variety of plant-based beverage substitutes are being created by the food sector as a result. To create viable alternatives, it is first necessary to provide an overview of the chemical composition, structure, features, and nutritional attributes of ordinary bovine milk. Sensory acceptability in the case of substitutes for beverages made from legumes is a significant barrier to their widespread acceptance, and thus saliva acts as a sophisticated fluid that serves a variety of purposes in the cavity of the mouth. Designing and producing next-generation plant-based beverages that mimic the physicochemical and functional qualities of conventional bovine-based beverages is gaining popularity, and many of these products can be thought of as colloidal materials that contain the particles or polymers that give them their unique qualities NG-PB foods can have a wide range of rheological qualities, such as fluids with low viscosity (such as plant-based beverages), high-viscosity liquids (like creams), soft liquids (like yogurt), as well as hard solids (such as some cheeses).


Assuntos
Bebidas , Leite , Humanos , Animais , Bebidas/análise , Leite/química , Bovinos , Paladar , Reologia , Boca , Manipulação de Alimentos/métodos , Saliva/química , Viscosidade , Fabaceae
19.
J Mater Sci Mater Med ; 35(1): 34, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38900233

RESUMO

Tissue engineering holds promise for developing therapeutic applications using viscous materials e.g. hydrogels. However, assessing the cytotoxicity of such materials with conventional assays can be challenging due to non-specific interactions. To address this, we optimized a live/dead staining method for quantitative evaluation and compared it with the conventional CCK8 assay. Our MicroDrop method involved seeding droplets containing 5000 cells in 10 µl medium on 12-well plates. After allowing them to adhere for 4 h, various viscous samples were applied to the cells and measurements were conducted using a fluorescence microscope immediately and at daily intervals up to 72 h. A sodium dodecyl sulfate (SDS) dilution series compared the MicroDrop with the CCK8 assay. The findings revealed a cell-type specific pattern for 10 mg/ml hyaluronic acid (HA), wherein MC3T3-E1 cells maintained 95% viability until 72 h, while L929 cells experienced a gradual decline to 17%. 2 mg/ml HA exhibited consistent viability above 90% across all time points and cell lines. Similarly, fibrin demonstrated 90% viability across dilutions and time points, except for undiluted samples showing a decrease from 85% to 20%. Gelatin-methacrylol sustained viability above 70% across all time points at both 5% and 10% concentrations. The comparison of the SDS dilution series between viability (MicroDrop) and metabolic activity (CCK8) assay showed a correlation coefficient of 0.95. The study validates the feasibility of the established assay, providing researchers with an efficient tool for assessing cytotoxicity in viscous materials. Additionally, it holds the potential to yield more precise data on well-known hydrogels.


Assuntos
Sobrevivência Celular , Ácido Hialurônico , Hidrogéis , Hidrogéis/química , Camundongos , Animais , Sobrevivência Celular/efeitos dos fármacos , Ácido Hialurônico/química , Viscosidade , Linhagem Celular , Teste de Materiais , Materiais Biocompatíveis/química , Engenharia Tecidual/métodos , Dodecilsulfato de Sódio/química , Gelatina/química , Fibrina/química
20.
Molecules ; 29(11)2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38893498

RESUMO

Due to the high content of impurities such as proteins in tamarind seed polysaccharide (TSP), they must be separated and purified before it can be used. TSP can disperse in cold water, but a solution can only be obtained by heating the mixture. Therefore, it is important to understand the dispersion and dissolution process of TSP at different temperatures to expand the application of TSP. In this study, pasting behavior and rheological properties as a function of temperature were characterized in comparison with potato starch (PS), and their relationship with TSP molecular features and microstructure was revealed. Pasting behavior showed that TSP had higher peak viscosity and stronger thermal stability than PS. Rheological properties exhibited that G' and G'' of TSP gradually increased with the increase in temperature, without exhibiting typical starch gelatinization behavior. The crystalline or amorphous structure of TSP and starch was disrupted under different temperature treatment conditions. The SEM results show that TSP particles directly transformed into fragments with the temperature increase, while PS granules first expanded and then broken down into fragments. Therefore, TSP and PS underwent different dispersion mechanisms during the dissolution process: As the temperature gradually increased, TSP possibly underwent a straightforward dispersion and was then dissolved in aqueous solution, while PS granules initially expanded, followed by disintegration and dispersion.


Assuntos
Polissacarídeos , Reologia , Sementes , Amido , Tamarindus , Temperatura , Tamarindus/química , Polissacarídeos/química , Sementes/química , Viscosidade , Amido/química , Fenômenos Químicos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...