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1.
PLoS One ; 19(7): e0305572, 2024.
Article in English | MEDLINE | ID: mdl-38954711

ABSTRACT

Green leafy vegetables are an essential component of Chinese leafy vegetables. Due to their crisp stems and tender leaves, orderly harvester generally causes significant mechanical clamping damage. The physical and mechanical properties of green leafy vegetables are one of the important basis to design the orderly harvester. At the same time, they provide important parameters for the simulation and optimization of harvester. So, this paper measured the physical characteristic parameters of roots and stems of green leafy vegetables. Then, based on the TMS-Pro texture analyzer, the elasticity modulus of the roots and stems of green leafy vegetables were measured. The static friction coefficient, dynamic friction coefficient, and restitution coefficient of green leafy vegetables root-root, stem-stem, root-steel, and stem-steel were measured separately using a combination method of inclined plane and high-speed photography. Uniaxial compression creep experiments were carried out on whole and single leaf of green leafy vegetables using the TA.XT plus C universal testing machine. The constitutive equation of the four-element Burgers model was used to fit the deformation curve of the sample with time during the constant-pressure loading stage. The fitting determination coefficients R2 were all higher than 0.996, which verified the reasonable validity of the selected model. The above experimental results provide a parameter basis and theoretical support for the design and discrete element simulation optimization of orderly harvester critical components of green leafy vegetables.


Subject(s)
Plant Leaves , Plant Roots , Vegetables , Viscosity , Plant Leaves/chemistry , Elasticity , Plant Stems/physiology
2.
Rev Sci Instrum ; 95(7)2024 Jul 01.
Article in English | MEDLINE | ID: mdl-39023347

ABSTRACT

Tear viscosity is a critical property affecting tear distribution and ocular surface stability. While not widely established as a primary diagnostic marker, deviations from normal viscosity can impact ocular health, potentially contributing to conditions such as dry eye syndrome. Despite their importance, traditional viscometers require sample volumes that are not feasible to use with tear volume. This research introduces a novel Quartz Crystal Microbalance (QCM)-based method for tear viscosity measurement, offering a viscometer prototype that operates with minimal sample volumes. Human tear samples, solutions used in artificial eye drops, and various commercial eye drop brands were evaluated. Results show that the QCM method aligns with established viscosity ranges. The average viscosity of healthy human tears was found to be 1.73 ± 0.61 cP, aligning with the typical range of 1-10 cP. Variability in the viscosities of eye drop can be attributed to differences in their chemical compositions. The QCM method offers benefits such as reduced sample consumption and rapid results, enhancing understanding of tear dynamics for ocular health. Further research with larger sample sizes is needed to establish normative viscosity values in healthy individuals and those with dry eye syndrome, which is crucial for validating the device's clinical efficacy.


Subject(s)
Quartz Crystal Microbalance Techniques , Tears , Viscosity , Tears/chemistry , Quartz Crystal Microbalance Techniques/instrumentation , Quartz Crystal Microbalance Techniques/methods , Humans , Ophthalmic Solutions/chemistry , Dry Eye Syndromes
3.
J Vis Exp ; (208)2024 Jun 28.
Article in English | MEDLINE | ID: mdl-39007608

ABSTRACT

Viscoelastic behavior can be beneficial in enhancing the unprecedented dynamics of polymer metamaterials or, in contrast, negatively impacting their wave control mechanisms. It is, therefore, crucial to properly characterize the viscoelastic properties of a polymer metamaterial at its working frequencies to understand viscoelastic effects. However, the viscoelasticity of polymers is a complex phenomenon, and the data on storage and loss moduli at ultrasonic frequencies are extremely limited, especially for additively manufactured polymers. This work presents a protocol to experimentally characterize the viscoelastic properties of additively manufactured polymers and to use them in the numerical analysis of polymer metamaterials. Specifically, the protocol includes the description of the manufacturing process, experimental procedures to measure the thermal, viscoelastic, and mechanical properties of additively manufactured polymers, and an approach to use these properties in finite-element simulations of the metamaterial dynamics. The numerical results are validated in ultrasonic transmission tests. To exemplify the protocol, the analysis is focused on acrylonitrile butadiene styrene (ABS) and aims at characterizing the dynamic behavior of a simple metamaterial made from it by using fused deposition modeling (FDM) three-dimensional (3D) printing. The proposed protocol will be helpful for many researchers to estimate viscous losses in 3D-printed polymer elastic metamaterials that will improve the understanding of material-property relations for viscoelastic metamaterials and eventually stimulate the use of 3D-printed polymer metamaterial parts in various applications.


Subject(s)
Elasticity , Viscosity , Printing, Three-Dimensional , Butadienes/chemistry , Polymers/chemistry , Acrylic Resins/chemistry , Finite Element Analysis , Manufactured Materials , Polystyrenes
4.
Int Wound J ; 21(7): e14964, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38994863

ABSTRACT

Negative pressure wound therapy is currently one of the most popular treatment approaches that provide a series of benefits to facilitate healing, including increased local blood perfusion with reduced localized oedema and control of wound exudate. The porous foam dressing is a critical element in the application of this therapy and its choice is based on its ability to manage exudate. Industry standards often employ aqueous solutions devoid of proteins to assess dressing performance. However, such standardized tests fail to capture the intricate dynamics of real wounds, oversimplifying the evaluation process. This study aims to evaluate the technical characteristics of two different commercial polyurethane foam dressings during negative pressure wound therapy. We introduce an innovative experimental model designed to evaluate the effects of this therapy on foam dressings in the presence of viscous exudates. Our findings reveal a proportional increase in dressing fibre occupancy as pressure intensifies, leading to a reduction in dressing pore size. The tests underscore the pressure system's diminished efficacy in fluid extraction with increasing fluid viscosity. Our discussion points to the need of establishing standardized guidelines for foam dressing selection based on pore size and the necessity of incorporating real biological exudates into industrial standards.


Subject(s)
Exudates and Transudates , Microscopy, Confocal , Negative-Pressure Wound Therapy , Polyurethanes , Wound Healing , Negative-Pressure Wound Therapy/methods , Humans , Viscosity , Microscopy, Confocal/methods , Bandages , Wounds and Injuries/therapy
5.
Molecules ; 29(13)2024 Jun 27.
Article in English | MEDLINE | ID: mdl-38999010

ABSTRACT

Hypochlorite (ClO-) and viscosity both affect the physiological state of mitochondria, and their abnormal levels are closely related to many common diseases. Therefore, it is vitally important to develop mitochondria-targeting fluorescent probes for the dual sensing of ClO- and viscosity. Herein, we have explored a new fluorescent probe, XTAP-Bn, which responds sensitively to ClO- and viscosity with off-on fluorescence changes at 558 and 765 nm, respectively. Because the emission wavelength gap is more than 200 nm, XTAP-Bn can effectively eliminate the signal crosstalk during the simultaneous detection of ClO- and viscosity. In addition, XTAP-Bn has several advantages, including high selectivity, rapid response, good water solubility, low cytotoxicity, and excellent mitochondrial-targeting ability. More importantly, probe XTAP-Bn is successfully employed to monitor the dynamic change in ClO- and viscosity levels in the mitochondria of living cells and zebrafish. This study not only provides a reliable tool for identifying mitochondrial dysfunction but also offers a potential approach for the early diagnosis of mitochondrial-related diseases.


Subject(s)
Fluorescent Dyes , Hypochlorous Acid , Mitochondria , Zebrafish , Hypochlorous Acid/analysis , Fluorescent Dyes/chemistry , Animals , Mitochondria/metabolism , Viscosity , Humans , Optical Imaging/methods , HeLa Cells
6.
Anal Chim Acta ; 1316: 342802, 2024 Aug 08.
Article in English | MEDLINE | ID: mdl-38969400

ABSTRACT

BACKGROUND: Cirrhosis represents the terminal stage of liver disease progression and timely intervention in a diseased liver can enhance the likelihood of recovery. Viscosity, a crucial parameter of the cellular microenvironment, is intricately linked to the advancement of cirrhosis. However, viscosity monitoring still faces significant challenges in achieving non-invasive and rapid early diagnosis of cirrhosis. Near-infrared (NIR) fluorescence imaging has the advantages of high sensitivity, non-destructive detection, and ignoring background fluorescence interference, plays an important role in diagnosing and treating various biological diseases. Hence, monitoring cellular viscosity changes with NIR fluorescence probe holds great significance in the early diagnosis of cirrhosis. RESULTS: In this study, the NIR fluorescence probe based on the intramolecular charge transfer (TICT) mechanism was developed for imaging applications in mouse model of liver cirrhosis. A molecular rotor-type viscosity-responsive probe was synthesized by linking dioxanthracene groups via carbon-carbon double bonds. The probe demonstrated remarkable sensitivity, high selectivity and photostability, with its responsiveness to viscosity largely unaffected by factors such as polarity, pH, and interfering ions. The probe could effectively detect various drug-induced changes in cellular viscosity, enabling the differentiation between normal cells and cancerous cells. Furthermore, the enhanced tissue penetration capabilities of probe facilitated its successful application in mouse model of liver cirrhosis, allowing for the assessment of liver disease severity based on fluorescence intensity and providing a powerful tool for early diagnosis of cirrhosis. SIGNIFICANCE: A NIR viscosity-sensitive fluorescent probe was specifically designed to effectively monitor alterations in cellular and organ viscosity, which could advance the understanding of the biological characteristics of cancer and provide theoretical support for the early diagnosis of cirrhosis. Overall, this probe held immense potential in monitoring viscosity-related conditions, expanding the range of biomedical tools available.


Subject(s)
Fluorescent Dyes , Liver Cirrhosis , Fluorescent Dyes/chemistry , Fluorescent Dyes/chemical synthesis , Liver Cirrhosis/diagnostic imaging , Liver Cirrhosis/pathology , Animals , Humans , Mice , Optical Imaging , Viscosity , Infrared Rays , Molecular Structure
7.
Clin Oral Investig ; 28(8): 436, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-39030259

ABSTRACT

OBJECTIVES: To evaluate the effect of whitening toothpastes with different hydrogen peroxide (HP) concentrations on HP permeability, color change, and physicochemical properties, compared to at-home bleaching treatment. MATERIALS AND METHODS: Forty-nine premolars were randomized into seven groups (n = 7): untreated (control); at-home bleaching with 10% carbamide peroxide gel (AH; 10% CP) with 14 and 28 applications of 180 min each (AH [14 × 180 min] and AH [28 × 180 min]); three whitening toothpastes (3% HP; 4% HP and 5% HP) and 10% CP brushed 28 times for 90 s each (TB [28 × 90 s]). HP permeability was measured using a UV-VIS spectrophotometer and color change by a digital spectrophotometer (ΔEab, ΔE00, and ΔWID). Initial concentration, pH, and viscosity were measured through titration, digital pH meter, and rheometer, respectively. Statistical analysis included one-way ANOVA, Tukey's test, and Dunnett's test (α = 0.05). RESULTS: 4% HP group showed acidic pH, the lowest viscosity and the highest HP concentration into the pulp chamber (p < 0.05). The 10% CP groups had lower HP in the pulp chamber and greater color change than other groups (p < 0.05), except the 5% HP group in ΔEab and ΔE00. For ΔWID, the 10% CP AH groups showed greater whitening than other groups (p < 0.05). CONCLUSIONS: Whitening toothpaste with up to 5% HP resulted in higher HP permeability and less color change compared to 10% CP. Higher HP commercial concentrations in toothpaste increased whitening effect; however, acidic pH toothpastes exhibited greater HP permeability. CLINICAL RELEVANCE: Whitening toothpastes with high hydrogen peroxide concentrations were less effective than at-home bleaching, resulting in less color change and greater permeability of hydrogen peroxide, potentially increasing the risk of tooth sensitivity.


Subject(s)
Carbamide Peroxide , Hydrogen Peroxide , Spectrophotometry , Tooth Bleaching Agents , Tooth Bleaching , Toothpastes , Tooth Bleaching/methods , Toothpastes/chemistry , Humans , Tooth Bleaching Agents/chemistry , In Vitro Techniques , Bicuspid , Viscosity , Hydrogen-Ion Concentration , Spectrophotometry, Ultraviolet , Urea/analogs & derivatives , Urea/pharmacology
8.
MAbs ; 16(1): 2379560, 2024.
Article in English | MEDLINE | ID: mdl-39028186

ABSTRACT

The self-association of therapeutic antibodies can result in elevated viscosity and create problems in manufacturing and formulation, as well as limit delivery by subcutaneous injection. The high concentration viscosity of some antibodies has been reduced by variable domain mutations or by the addition of formulation excipients. In contrast, the impact of Fc mutations on antibody viscosity has been minimally explored. Here, we studied the effect of a panel of common and clinically validated Fc mutations on the viscosity of two closely related humanized IgG1, κ antibodies, omalizumab (anti-IgE) and trastuzumab (anti-HER2). Data presented here suggest that both Fab-Fab and Fab-Fc interactions contribute to the high viscosity of omalizumab, in a four-contact model of self-association. Most strikingly, the high viscosity of omalizumab (176 cP) was reduced 10.7- and 2.2-fold by Fc modifications for half-life extension (M252Y:S254T:T256E) and aglycosylation (N297G), respectively. Related single mutations (S254T and T256E) each reduced the viscosity of omalizumab by ~6-fold. An alternative half-life extension Fc mutant (M428L:N434S) had the opposite effect in increasing the viscosity of omalizumab by 1.5-fold. The low viscosity of trastuzumab (8.6 cP) was unchanged or increased by ≤2-fold by the different Fc variants. Molecular dynamics simulations provided mechanistic insight into the impact of Fc mutations in modulating electrostatic and hydrophobic surface properties as well as conformational stability of the Fc. This study demonstrates that high viscosity of some IgG1 antibodies can be mitigated by Fc mutations, and thereby offers an additional tool to help design future antibody therapeutics potentially suitable for subcutaneous delivery.


Subject(s)
Immunoglobulin Fc Fragments , Immunoglobulin G , Mutation , Omalizumab , Trastuzumab , Humans , Trastuzumab/chemistry , Viscosity , Omalizumab/chemistry , Immunoglobulin Fc Fragments/chemistry , Immunoglobulin Fc Fragments/genetics , Immunoglobulin G/genetics , Immunoglobulin G/chemistry , Immunoglobulin Fab Fragments/chemistry , Immunoglobulin Fab Fragments/genetics
9.
PLoS One ; 19(7): e0302202, 2024.
Article in English | MEDLINE | ID: mdl-38950007

ABSTRACT

It is structurally pertinent to understudy the important roles the self-compacting concrete (SCC) yield stress and plastic viscosity play in maintaining the rheological state of the concrete to flow. It is also important to understand that different concrete mixes with varying proportions of fine to coarse aggregate ratio and their nominal sizes produce different and corresponding flow- and fill-abilities, which are functions of the yield stress/plastic viscosity state conditions of the studied concrete. These factors have necessitated the development of regression models, which propose optimal rheological state behavior of SCC to ensure a more sustainable concreting. In this research paper on forecasting the rheological state properties of self-compacting concrete (SCC) mixes by using the response surface methodology (RSM) technique, the influence of nominal sizes of the coarse aggregate has been studied in the concrete mixes, which produced experimental mix entries. A total of eighty-four (84) concrete mixes were collected, sorted and split into training and validation sets to model the plastic viscosity and the yield stress of the SCC. In the field applications, the influence of the sampling sizes on the rheological properties of the concrete cannot be overstretched due to the importance of flow consistency in SCC in order to achieve effective workability. The RSM is a symbolic regression analysis which has proven to exercise the capacity to propose highly performable engineering relationships. At the end of the model exercise, it was found that the RSM proposed a closed-form parametric relationship between the outputs (plastic viscosity and yield stress) and the studied independent variables (the concrete components). This expression can be applied in the design and production of SCC with performance accuracies of above 95% and 90%, respectively. Also, the RSM produced graphical prediction of the plastic viscosity and yield stress at the optimized state conditions with respect to the measured variables, which could be useful in monitoring the performance of the concrete in practice and its overtime assessment. Generally, the production of SCC for field applications are justified by the components in this study and experimental entries beyond which the parametric relations and their accuracies are to be reverified.


Subject(s)
Construction Materials , Rheology , Rheology/methods , Construction Materials/analysis , Viscosity , Materials Testing/methods , Forecasting/methods
10.
Front Cell Infect Microbiol ; 14: 1411286, 2024.
Article in English | MEDLINE | ID: mdl-38947124

ABSTRACT

Background: Convergence of Klebsiella pneumoniae (KP) pathotypes has been increasingly reported in recent years. These pathogens combine features of both multidrug-resistant and hypervirulent KP. However, clinically used indicators for hypervirulent KP identification, such as hypermucoviscosity, appear to be differentially expressed in convergent KP, potential outbreak clones are difficult to identify. We aimed to fill such knowledge gaps by investigating the temperature dependence of hypermucoviscosity and virulence in a convergent KP strain isolated during a clonal outbreak and belonging to the high-risk sequence type (ST)307. Methods: Hypermucoviscosity, biofilm formation, and mortality rates in Galleria mellonella larvae were examined at different temperatures (room temperature, 28°C, 37°C, 40°C and 42°C) and with various phenotypic experiments including electron microscopy. The underlying mechanisms of the phenotypic changes were explored via qPCR analysis to evaluate plasmid copy numbers, and transcriptomics. Results: Our results show a temperature-dependent switch above 37°C towards a hypermucoviscous phenotype, consistent with increased biofilm formation and in vivo mortality, possibly reflecting a bacterial response to fever-like conditions. Furthermore, we observed an increase in plasmid copy number for a hybrid plasmid harboring carbapenemase and rmpA genes. However, transcriptomic analysis revealed no changes in rmpA expression at higher temperatures, suggesting alternative regulatory pathways. Conclusion: This study not only elucidates the impact of elevated temperatures on hypermucoviscosity and virulence in convergent KP but also sheds light on previously unrecognized aspects of its adaptive behavior, underscoring its resilience to changing environments.


Subject(s)
Biofilms , Klebsiella Infections , Klebsiella pneumoniae , Temperature , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/pathogenicity , Klebsiella pneumoniae/classification , Biofilms/growth & development , Virulence/genetics , Animals , Klebsiella Infections/microbiology , Larva/microbiology , Plasmids/genetics , Moths/microbiology , Humans , Virulence Factors/genetics , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Lepidoptera/microbiology , Viscosity , Phenotype , Gene Expression Profiling
11.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 55(3): 769-776, 2024 May 20.
Article in Chinese | MEDLINE | ID: mdl-38948293

ABSTRACT

Objective: To experimentally validate the effects of a self-developed heat-stable thickening agent on the textual characteristics of enteral nutrition solutions of standard concentration and its applicability in improving dysphagia. Methods: A gradient of different doses of the self-developed thickening agent (1.0 g, 1.5 g, 2.0 g, 2.5 g, and3.0 g) and three commonly used commercial thickeners were mixed with 23.391 g of a complete nutrition formula powder dissolved in 85 mL of purified water to prepare 100 mL standard concentration nutrition solutions. The textual parameters (cohesiveness, viscosity, thickness, and hardness) of these nutrition solutions were measured using a texture analyzer at various temperature gradients (20 ℃, 40 ℃, 60 ℃, and 80 ℃) to compare their thermal stability. A dysphagia rat model was created via epiglottectomy to explore the effects of the thickener on lung tissue damage scores and levels of inflammatory markers. The rats were divided into a test intervention group, a positive control group, a negative control group, and a blank control group (no surgery and normal feeding after fasting for one day), with 15 rats in each group. After fasting for one day post-surgery, the test intervention group was fed with the standard concentration nutrition solution thickened with the self-developed thickener, while the positive control group was given a standard concentration nutrition solution thickened with product 3, and the negative control group was fed a normal diet. All groups were fed for two weeks with food dyed with food-grade green dye. General conditions, body mass, and food intake were observed and recorded. After two weeks, abdominal aorta blood was collected, and heart, liver, spleen, lung, and kidney tissues were harvested and weighed to calculate the lung tissue organ coefficient. The organ conditions were evaluated using routine H&E staining, and lung damage was semi-quantitatively analyzed based on the Mikawa scoring criteria. Blood supernatants were collected to measure the total serum protein and albumin levels to determine the nutritional status of the rats. The expression of IL-6 and TNF-α genes in lung tissues was measured by RT-qPCR. IL-6 and TNF-α protein expression levels in lung tissues, lung tissue homogenate, and serum were measured by ELISA. The aspiration incidence rate was calculated. Results: Within the dosage range of 1.0 g to 3.0 g, the self-developed thickener in the test samples exhibited superior thermal stability in cohesiveness compared to the three commercially available thickeners, with a statistically significant difference (P<0.01). The differences in the thermal stability of viscosity and hardness between the self-developed thickener and the three commercially available thickeners were not statistically significant. The viscosity stability was optimal for the self-developed thickener, followed by the commercially available thickeners 1 and 3, with thickeners 2 being the least stable, though the differences were not statistically significant (P>0.05). Product 1 showed the best thermal stability in thickness, followed by the self-developed thickener and product 2, while the product 3 exhibited the worst performance, with the difference being statistically significant (P<0.01). The self-developed thickener had the best thermal stability in hardness at temperatures ranging from 20℃ to 80 ℃, followed by products 1 and 2, with product 3 being the least stable. However, the differences were not statistically significant (P>0.05). Animal experiment results indicated that the body weight gain in the positive control group and the test intervention group was lower than that in the blank and negative control groups (P<0.01). The spleen coefficient of the intervention group was lower than that of the positive control group and the blank control group (P<0.01), while the heart, liver, and kidney coefficients were lower than those of the blank control group (P<0.01). The differences in the lung coefficient of the intervention group and those of the other three groups were no statistically significant. Levels of TP and ALB in the test intervention group, the positive control group, and the negative control group were all lower than those in the blank control group, with statistically significant differences (P<0.01). ELISA results showed that serum IL-6 levels in the blank and test intervention groups were lower than those in the negative and positive control groups (P<0.05), while the difference in the other indicators across the four groups were not statistically significant (P>0.05). There were no statistically significant differences among the four groups in terms of lung tissue damage pathology scores, or in the levels of IL-6 and TNF-α gene expression in lung tissues. The aspiration incidence rate was 0% in all groups. Conclusion: The self-developed enteral nutrition thickening agent demonstrated excellent thermal stability and swallowing safety. Further research to explore its application in patients with dysphagia is warranted.


Subject(s)
Deglutition Disorders , Enteral Nutrition , Animals , Rats , Deglutition Disorders/etiology , Enteral Nutrition/methods , Rats, Sprague-Dawley , Deglutition/physiology , Male , Lung/physiology , Hot Temperature , Viscosity
12.
J Food Sci ; 89(7): 4419-4429, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38957111

ABSTRACT

The objective of this research was to evaluate changes in flow behavior of chocolate during chocolate grinding using a stone grinder as affected by chocolate formulation. Three different types of chocolates were evaluated. Two chocolates without milk added (70% chocolate) and two chocolates with milk added and with different amounts of cocoa nibs (30% chocolate and 14% chocolate) were tested. For the 70% chocolates, nibs of two different origins were used; therefore, a total of four samples were evaluated. Chocolates were processed in a stone grinder, and samples were taken as a function of grinding time. For each timepoint, the flow behavior of the samples was measured using a rotational rheometer and fitted to the Casson model. Particle size was measured using a laser scattering instrument. Results showed that yield stress increased linearly while the Casson plastic viscosity decreased exponentially with grinding time (smaller particles). Particle size distribution of the chocolates showed a prominent bimodal distribution for short grinding times (∼9 h) with small (∼15 µm) and large (∼100 µm) particles; with longer grinding time, the population of larger particles decreased. Yield stress values were higher for the 70% chocolate, but they were not very different between the two milk chocolates tested. The Casson plastic viscosity was greatest for the 70% chocolate, followed by the 30% chocolate. The 14% chocolate had the lowest Casson plastic viscosity. Changes of Casson plastic viscosity with particle size were more evident for the dark chocolates compared to the milk ones. These results are helpful to small chocolate producers who need better understanding of how the formulation and grinding of chocolate affect its flow behavior, which will ultimately affect chocolate handling during production.


Subject(s)
Chocolate , Food Handling , Milk , Particle Size , Chocolate/analysis , Food Handling/methods , Viscosity , Milk/chemistry , Rheology , Cacao/chemistry , Animals
13.
J Texture Stud ; 55(4): e12852, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38952166

ABSTRACT

The development of thickening powders for the management of dysphagia is imperative due to the rapid growth of aging population and prevalence of the dysphagia. One promising thickening agent that can be used to formulate dysphagia diets is basil seed mucilage (BSM). This work investigates the effects of dispersing media, including water, milk, skim milk, and apple juice, on the rheological and tribological properties of the BSM-thickened liquids. Shear rheology results revealed that the thickening ability of BSM in these media in ascending order is milk < skim milk ≈ apple juice < water. On the other hand, extensional rheology demonstrated that the longest filament breakup time was observed when BSM was dissolved in milk, followed by skim milk, water, and apple juice. Furthermore, tribological measurements showed varying lubrication behavior, depending on the BSM concentration and dispersing media. Dissolution of BSM in apple juice resulted in the most superior lubrication property compared with that in other dispersing media. Overall, this study provides insights on BSM's application as a novel gum-based thickening powder in a range of beverages and emphasizes how important it is for consumers to have clear guidance for the use of BSM in dysphagia management.


Subject(s)
Ocimum basilicum , Plant Mucilage , Rheology , Seeds , Ocimum basilicum/chemistry , Seeds/chemistry , Plant Mucilage/chemistry , Animals , Milk/chemistry , Viscosity , Deglutition Disorders , Malus/chemistry , Fruit and Vegetable Juices/analysis , Humans , Water , Powders , Lubrication
14.
J Texture Stud ; 55(4): e12850, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38952176

ABSTRACT

This study examined the effects of spread formulation and the structural/lubricant properties of six different commercial hazelnut and cocoa spreads on sensory perception. Rheology, tribology, and quantitative descriptive analysis (QDA) was assessed by also evaluating the correlation coefficients between the quality descriptor and the rheological and textural parameters. The viscosity was evaluated at different temperatures to better simulate conditions before and after ingestion. Tribological analysis was executed at 37°C to mimic the human oral cavity. The effect of saliva presence and the number of runs on tribological behaviors was investigated. Moreover, textural, calorimetric, and particle size distribution measurements were performed to reinforce the correlation between structural/thermal parameters (e.g., firmness, stickiness, sugar melting point) and sensory aspects. "Visual viscosity," defined as a sensory attribute evaluated prior to consumption, negatively correlated with apparent viscosity measured at 20°C and 10 s-1, whereas "body," defined during oral processing and related to creaminess, positively correlated with apparent viscosity measured at 37°C and 50 s-1. These attributes were mainly influenced by particulate microstructure and solid volume fraction within the formulation. Textural stickiness positively correlated with sensory "adhesiveness" and was related to fat composition and milk powder addition, while "sweetness" was related to sucrose content and sugar melting enthalpy. Tribological data provided meaningful information related to particle-derived attributes, as well as after-coating perception (fattiness/oiliness), thus better predicting food evolution during oral consumption.


Subject(s)
Cacao , Corylus , Rheology , Taste , Humans , Viscosity , Cacao/chemistry , Mouth/physiology , Particle Size , Adult , Female , Male , Saliva/chemistry , Young Adult
15.
J Texture Stud ; 55(4): e12851, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38952153

ABSTRACT

Rheological properties of gastric contents depend on the food ingested, and on the volume and composition of secretions from the host, which may vary. This study investigates the impact of saliva regular incorporation in the stomach after a meal on the rheological properties of gastric contents, considering two levels of salivary flow (low = 0.5 and high = 1.5 mL/min). In vitro chymes were obtained by mixing sour cream, simulated gastric fluid, two different volumes of oral fluid (at-rest human saliva, SSF for Simulated Salivary Fluid or water) and adjusting pH at 3. Chymes samples were characterized at 37°C for their particle size and rheological properties. Overall, particle size distribution was not different between samples: incorporating a larger volume of saliva resulted in more heterogeneity, but the surface area moment D[3,2] and volume moment D[4,3] did not differ significantly with the oral fluid type. Shear viscosity of chyme samples was higher when saliva was incorporated, in comparison with water or SSF. In addition, as shown from data extracted at γ ̇ $$ \dot{\gamma} $$ = 20 s-1 the higher the fluid volume the lower the shear viscosity, which is attributed to a dilution effect. However, this dilution effect was attenuated in the case of saliva, most likely due to its composition in organic compounds (e.g., mucins) contributing to the rheological properties of this biological fluid. In these in vitro conditions, both saliva and the salivation rate had a significant but slight impact on the rheological properties of gastric contents (of the order of 1-5 mPa s at γ ̇ $$ \dot{\gamma} $$ = 20 s-1).


Subject(s)
Particle Size , Rheology , Saliva , Saliva/chemistry , Humans , Viscosity , Gastrointestinal Contents/chemistry , Hydrogen-Ion Concentration , Gastric Juice/chemistry
16.
Drug Deliv ; 31(1): 2372277, 2024 Dec.
Article in English | MEDLINE | ID: mdl-38952058

ABSTRACT

Skin melanoma is considered the most dangerous form of skin cancer due to its association with high risk of metastasis, high mortality rate and high resistance to different treatment options. Genistein is a natural isoflavonoid with known chemotherapeutic activity. Unfortunately, it has low bioavailability due to its poor aqueous solubility and excessive metabolism. In the current study, genistein was incorporated into transferosomal hydrogel to improve its bioavailability. The prepared transferosomal formulations were characterized regarding: particle size; polydispersity index; zeta potential; encapsulation efficiency; TEM; FTIR; DSC; XRD; in vitro drug release; viscosity; pH; ex vivo anti-tumor activity on 3D skin melanoma spheroids and 1-year stability study at different storage temperatures. The optimized formulation has high encapsulation efficiency with an excellent particle size that will facilitate its penetration through the skin. The transfersomes have a spherical shape with sustained drug release profile. The anti-tumor activity evaluation of genistein transfersome revealed that genistein is a potent chemotherapeutic agent with enhanced penetration ability through the melanoma spheroids when incorporated into transfersomes. Stability study results demonstrate the high physical and chemical stability of our formulations. All these outcomes provide evidence that our genistein transferosomal hydrogel is a promising treatment option for skin melanoma.


Subject(s)
Drug Liberation , Genistein , Hydrogels , Melanoma , Particle Size , Skin Neoplasms , Genistein/administration & dosage , Genistein/pharmacology , Genistein/pharmacokinetics , Melanoma/drug therapy , Skin Neoplasms/drug therapy , Humans , Hydrogels/chemistry , Drug Delivery Systems/methods , Cell Line, Tumor , Drug Stability , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/pharmacology , Antineoplastic Agents/pharmacokinetics , Solubility , Drug Carriers/chemistry , Chemistry, Pharmaceutical , Viscosity , Biological Availability , Administration, Cutaneous , Spheroids, Cellular/drug effects
17.
Sci Rep ; 14(1): 15493, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38969808

ABSTRACT

Dispersion of Basil seed gum has high viscosity and exhibits shear-thinning behavior. This study aimed to analyze the influence of microwave treatment (MT) at various time intervals (0, 1, 2, and 3 min) on the viscosity and rheological behavior of Basil seed gum dispersion (0.5%, w/v). The finding of this study revealed that the apparent viscosity of Basil seed gum dispersion (non-treated dispersion) reduced from 0.330 Pa.s to 0.068 Pa.s as the shear rate (SR) increased from 12.2 s-1 to 171.2 s-1. Additionally, the apparent viscosity of the Basil seed gum dispersion reduced from 0.173 Pa.s to 0.100 Pa.s as the MT time increased from 0 to 3 min (SR = 61 s-1). The rheological properties of gum dispersion were successfully modeled using Power law (PL), Bingham, Herschel-Bulkley (HB), and Casson models, and the PL model was the best one for describing the behavior of Basil seed gum dispersion. The PL model showed an excellent performance with the maximum r-value (mean r-value = 0.942) and the minimum sum of squared error (SSE) values (mean SSE value = 5.265) and root mean square error (RMSE) values (mean RMSE value = 0.624) for all gum dispersion. MT had a considerable effect on the changes in the consistency coefficient (k-value) and flow behavior index (n-value) of Basil seed gum dispersion (p < 0.05). The k-value of Basil seed gum dispersion decreased significantly from 3.149 Pa.sn to 1.153 Pa.sn (p < 0.05) with increasing MT time from 0 to 3 min. The n-value of Basil seed gum dispersion increased significantly from 0.25 to 0.42 (p < 0.05) as the MT time increased. The Bingham plastic viscosity of Basil seed gum dispersion increased significantly from 0.029 Pa.s to 0.039 Pa.s (p < 0.05) while the duration of MT increased. The Casson yield stress of Basil seed gum dispersion notably reduced from 5.010 Pa to 2.165 Pa (p < 0.05) with increasing MT time from 0 to 3 min.


Subject(s)
Microwaves , Ocimum basilicum , Plant Gums , Rheology , Seeds , Ocimum basilicum/chemistry , Seeds/chemistry , Viscosity , Plant Gums/chemistry
18.
Sci Rep ; 14(1): 15498, 2024 Jul 05.
Article in English | MEDLINE | ID: mdl-38969829

ABSTRACT

Black liquor (BL) is the major bioproduct and biomass fuel in pulp mill processes. However, the high viscosity of BL makes it a challenging material to work with, resulting in issues with evaporators and heat exchangers during its transport and processing. The thermal and rheological properties of BLs from Pinus sp. (PBL) and Eucalyptus sp. (EBL) were studied. FTIR spectra revealed the presence of the characteristic functional groups and the chemical composition in liquors. TGA/DTG curves showed three characteristic degradation stages related to evaporation of water, pyrolysis of organic groups, and condensation of char. Rheologically, liquors are classified as non-Newtonian and with comportment pseudoplastic. Their rheological dynamic shear properties included a linear viscoelastic region up to 1% shear strain, while frequency sweeps showed that storage modulus (G') > loss modulus (G''), thus confirming the solid-like behavior of both BLs. The rheological study demonstrated that increasing the temperature and oscillatory deformations of PBL and EBL decreased their degree of viscoelasticity, which could favor their pumping and handling within the pulp mill, as well as the droplet formation and swelling characteristics in the recovery furnace.


Subject(s)
Eucalyptus , Pinus , Rheology , Eucalyptus/chemistry , Pinus/chemistry , Viscosity , Brazil , Finland , Temperature , Spectroscopy, Fourier Transform Infrared
19.
Biophys Chem ; 312: 107286, 2024 Sep.
Article in English | MEDLINE | ID: mdl-38964115

ABSTRACT

1H-1H nuclear cross-relaxation experiments have been carried out with lysozyme in variable glycerol viscosity to study intramolecular motion, self-diffusion, and isotropic rigid-body rotational tumbling at 298 K, pH 3.8. Dynamics of intramolecular 1H-1H cross-relaxation rates, the increase in internuclear spatial distances, and lateral and rotational diffusion coefficients all show fractional viscosity dependence with a power law exponent κ in the 0.17-0.83 range. The diffusion coefficient of glycerol Ds with the bulk viscosity itself is non-Stokesian, having a fractional viscosity dependence on the medium viscosity (Ds âˆ¼ Î·-κ, κ ≈ 0.71). The concurrence and close similarity of the fractional viscosity dependence of glycerol diffusion on the one hand, and diffusion and intramolecular cross-relaxation rates of the protein on the other lead to infer that relaxation of glycerol slaves protein relaxations. Glycerol-transformed native lysozyme to a quasi-native state does not affect the conclusion that both global and internal fluctuations are slaved to glycerol relaxation.


Subject(s)
Glycerol , Muramidase , Muramidase/chemistry , Muramidase/metabolism , Glycerol/chemistry , Viscosity , Proton Magnetic Resonance Spectroscopy , Nuclear Magnetic Resonance, Biomolecular , Diffusion , Animals , Chickens
20.
Nat Commun ; 15(1): 5782, 2024 Jul 10.
Article in English | MEDLINE | ID: mdl-38987269

ABSTRACT

Self-regenerating trigger waves can spread rapidly through the crowded cytoplasm without diminishing in amplitude or speed, providing consistent, reliable, long-range communication. The macromolecular concentration of the cytoplasm varies in response to physiological and environmental fluctuations, raising the question of how or if trigger waves can robustly operate in the face of such fluctuations. Using Xenopus extracts, we find that mitotic and apoptotic trigger wave speeds are remarkably invariant. We derive a model that accounts for this robustness and for the eventual slowing at extremely high and low cytoplasmic concentrations. The model implies that the positive and negative effects of cytoplasmic concentration (increased reactant concentration vs. increased viscosity) are nearly precisely balanced. Accordingly, artificially maintaining a constant cytoplasmic viscosity during dilution abrogates this robustness. The robustness in trigger wave speeds may contribute to the reliability of the extremely rapid embryonic cell cycle.


Subject(s)
Cytoplasm , Mitosis , Xenopus laevis , Animals , Cytoplasm/metabolism , Apoptosis , Viscosity , Cell Extracts/chemistry , Models, Biological , Xenopus , Cell Cycle
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