High Hydration Levels Research Articles

Response of the distribution and molecular transition of gluten proteins and quality of Chinese steamed bread to different hydration levels

This study systematically explored how different hydration levels (45 %, 50 %, and 55 % water addition) affect the evolution of gluten network morphology, distribution, conformational and molecular transition, and moisture migration during the processing of Chinse steamed bread (CSB), and their impact on quality formation. Higher hydration levels resulted in a more uniform distribution and fibrous structure of the gluten network during mixing. However, excessive hydration (55 %) caused gluten fibers to rupture during fermentation. This increased the specific volume but decreased the chewiness and stickiness of CSB. MRI results highlighted that differences in moisture migration and internal structure among samples with different hydration levels were enlarged after steaming. AFM images revealed the increase in both protein molecular chain height and width with increasing hydration level, particularly after steaming. Moreover, high hydration levels promoted the depolymerization of glutenin macropolymers during mixing, fermentation, as well as repolymerization during cooking. These results indicated that both macroscopic qualities and molecular structure of gluten protein became more sensitive to the physical and biochemical processes during CSB processing. These dynamic transitions play a crucial role in determining dough rheological properties and CSB's overall quality. This research offers theoretical insights for precise dough product regulation and understanding underlying mechanisms.

Acai Oil-Based Organogel Containing Hyaluronic Acid for Topical Cosmetic: In Vitro and Ex Vivo Assessment.

Organogels are semi-solid pharmaceutical forms whose dispersing phase is an organic liquid, for example, an oil, such as acai oil, immobilized by a three-dimensional network formed by the gelling agent. Organogels are being highlighted as innovative release systems for cosmetic active ingredients such as hyaluronic acid for topical applications. Acai oil was evaluated for its physicochemical parameters, fatty acid composition, lipid quality index, spectroscopic pattern (Attenuated total reflectance Fourier Transform Infrared Spectroscopy), thermal behavior, total phenolic, total flavonoids, and total carotenoids and β-carotene content. The effectiveness of the organogel incorporated with hyaluronic acid (OG + HA) was evaluated through ex vivo permeation and skin retention tests, in vitro tests by Attenuated total reflectance Fourier Transform Infrared Spectroscopy and Differential Scanning Calorimetry. The physicochemical analyses highlighted that the acai oil exhibited quality standards in agreement with the regulatory bodies. Acai oil also showed high antioxidant capacity, which was correlated with the identified bioactive compounds. The cytotoxicity tests demonstrated that the formulation OG + HA does not release toxic substances into the biological environment that could impede cell growth, adhesion, and efficacy. In vitro and ex vivo analyses demonstrated that after 6 h of application, OG + HA presented a high level of hydration, thermal protection and release of HA. Thus, it can be concluded that the OG + HA formulation has the potential for physical-chemical applications, antioxidant quality, and potentially promising efficacy for application in the cosmetic areas.

The sound of lichens: ultrasonic acoustic emissions during desiccation question cavitation events in the hyphae.

Lichens are a mutualistic symbiosis between a fungus and one or more photosynthetic partners. They are photosynthetically active during desiccation until relative water contents (RWC) as low as 30% (on dry mass). Experimental evidence suggests that during desiccation, the photobionts have a higher hydration level than the surrounding fungal pseudo-tissues. Explosive cavitation events in the hyphae might cause water movements towards the photobionts. This hypothesis was tested in two foliose lichens by measurements of ultrasonic acoustic emissions (UAE), a method commonly used in vascular plants but never in lichens, and by measurements of photosystem II efficiency, water potential and RWC. Thallus structural changes were characterised by low-temperature scanning electron microscopy. The thalli were silent between 380% and 30% RWCs, i.e. when explosive cavitation events should cause movements of liquid water. Nevertheless, the thalli emitted UAE at approximately 5% RWC. Accordingly, the medullary hyphae were partially shrunk at about 15% RWC, whereas they were completely shrunk below 5% RWC. These results do not support the hypothesis of hyphal cavitation and suggest that the UAE originate from structural changes at hyphal level. The shrinking of hyphae is proposed as an adaptation to avoid cell damage at very low RWCs.

A stable and low-fouling lead ion-selective electrode employing polyaniline-MXene composite for solid contact and polypeptide for antifouling

A biofouling-resistant solid-contact lead ion-selective electrode (Pb2+-ISE) with enhanced stability was developed based on dendritic peptides and polyaniline-MXene composites. The biofouling-resistant dendritic peptides, characterized by their high level of hydration and relative conformational entropy, effectively inhibit nonspecific adsorption. Simultaneously, the synergy between polyaniline nanowires and MXene nanosheets is harnessed to enhance the ion-electron transfer rate, thereby improving the stability of the ISE. The fabricated Pb2+-ISEs exhibit commendable electrochemical short-term stability and can rapidly respond to potential changes within 1 second. Under bacterial solution storage conditions, the peptide-modified ISEs maintain their Nernstian response without significant alteration for up to six days. Additionally, the Pb2+-ISEs are insensitive to O2, CO2, N2, and light, making them suitable for the analysis of Pb2+ in real complex samples. The strategic design incorporating dendritic peptides as a biofouling-resistant layer and the PANI-MXene composite as a conductive layer offers an effective approach to construct low-fouling ISEs capable of operating robustly in complex systems.

Characteristics of and foundation application among Chinese females with sensitive skin.

We conducted a study on women with sensitive skin of various skin tones to analyse their skin characteristics and preferences for foundation shades. Volunteers were categorized based on their individual typological angle, and their preferences were assessed using self-perception and software-based mass aesthetic assessment. The Baumann Questionnaire is a valuable tool for identifying patients with sensitive skin and gaining a comprehensive understanding of their skin sensitivity. The skin characteristics of two groups were compared using a more suitable classification method. Individuals diagnosed with sensitive skin typically have skin tones classified as Types I, II and III, with Type I being the most common in sensitive skin cases. The sensitive group exhibited higher levels of transepidermal water loss, lighter skin tone, lower yellowness, increased glossiness, higher haemoglobin content, more acne, fewer blackheads, and fewer pores. Among them, Type I skin is characterized by lower elasticity, increased oiliness, higher hydration levels and fewer visible pores. Type II skin is characterized by lower hydration levels, higher oiliness and increased redness. Type III exhibits more pores, decreased oiliness and enhanced elasticity. Foundations No. 2 and No. 3 are fairer than foundations No. 1 and No. 4. In the self-assessment, Type I and Type II subjects preferred No. 3, while Type III subjects preferred No. 1 and No. 4 because they matched their skin tone. The results of the software evaluation showed that popular aesthetics preferred Type I and Type II to use No. 2, and Type III to use No. 2 and No. 3, as they resulted in a fairer complexion. Sensitive skin of different skin tone types confronts different skin problems. The findings also highlight the public's inclination towards lighter foundation shades, despite the common practice of selecting shades that harmonize with one's inherent skin tone.

ZnO sintering additive without negative impact on proton-conducting SrHf0.8Sc0.2O3-δ electrolyte

Many proton-conducting oxides are refractory, making it difficult to fabricate dense electrolyte membranes for electrochemical devices. The use of a sintering additive is a common strategy, although it often has a negative effect on proton transport. We found that the addition of ZnO (2 and 4 mol%) successfully contributes to densification of SrHf0.8Sc0.2O3-δ ceramics at 1450 °C without negative consequences for the ionic transport. The chemical stability of the materials, high levels of hydration and proton conductivity were confirmed. ZnO is partially (less than 0.3 mol%) incorporated into the crystal lattice of the perovskite and partially accumulates at grain boundaries gradually volatilizing during high-temperature treatments. As a result, ZnO sintering additive does not influence the bulk and specific grain-boundary conductivities, ionic transference numbers and hydration ability, maintaining the excellent electrolytic properties of SrHf0.8Sc0.2O3-δ ceramics.

1,2,3-Triazolium vs 1,2,4-triazolium quaternized poly (2, 6-dimethyl-1, 4-phenylene oxide) (PPO) anion exchange membranes (AEMs): A molecular dynamics (MD) study

This work investigates AEMs prepared from Poly (2, 6-dimethyl-1, 4-Phenylene Oxide) (PPO) quaternized with 1,2,3-triazolium and 1,2,4-triazolium, using molecular dynamics (MD) simulations to compare and evaluate their hydroxide transport and their stability against hydroxide degradation at different hydration levels. Hydroxide diffusivity (DOH) at λ = 6 is 0.69 × 10−10 m2/s, and 0.23 × 10−10 m2/s, at λ = 9 is 0.97 × 10−10 m2/s, and 0.67 × 10−10 m2/s and at λ = 12 is 1.85 × 10−10 m2/s, and 1.69 × 10−10 m2/s for 1,2,3-triPPO and 1,2,4-triPPO, respectively. At lower hydration levels (λ = 6 and λ = 9), 1,2,4-triPPO is stable against hydroxide degradation. However, at higher hydration levels, 1,2,3-triPPO has fewer hydroxide ions around the cationic group due to the hydroxide ions being solvated by the water, making it harder for the hydroxide ions to approach the cationic group at higher hydration levels, which means 1,2,3-triPPO is stable against hydroxide degradation.

Moisture uptake of a nonwoven geotextile carrier-GCL from Lateritic subsoils under simulated tropical thermal conditions

Environmental conditions have become a concern when involving the use of Geosynthetics clay liners (GCLs) as leachate barriers, particularly because they can be subjected to daily thermal cycles during construction and operation of landfills, which can affect their properties. This paper investigates the hydration behavior of a nonwoven geotextile carrier-GCL in contact with lateritic subsoils under isothermal and simulated thermal conditions as commonly found in tropical regions. A thermal insulate testing box was used to shelter an instrumented liner landfill allowing the investigation of thermal and hydraulic responses during hydration. Lateritic subsoils were observed not to provide high levels of GCLs hydration under isothermal conditions, whereas thermal daily cycles led to capillary break that restricted the moisture uptake at the interface between subsoil and the nonwoven geotextile carrier. Higher values of subsoil initial moisture contents were found to be significant to reduce capillary effects and to allow some GCL hydration. The poor hydration demonstrated to be critical in terms of GCL hydraulic behavior.

Molecular weight impacts the alkaline stability of poly(terphenylene alkylene) anion exchange membranes

Improving the alkaline durability is crucial for developing anion exchange membranes used for electrochemical energy devices. In contrast to the exploitation of new cationic moieties or robust polymer backbone, the influence of polyelectrolyte molecular weight on the membrane's alkaline stability has received little attention. In this contribution, quaternized poly(terphenylene alkylene)s with Mw ranging from 30 to 118 kDa were synthesized to quantify the variations in alkaline stability and other physicochemical properties. Measurements of ex-situ alkaline soaking, either in high or low hydration levels, and in-situ cell operating demonstrate that Mw is positively correlated to the alkaline stability of the membrane. In addition, the water absorption and ion conductivity of AEM are negatively correlated to its Mws, and incline to reach a plateau as the Mw over 100 kDa. These results have important implications to elucidate the alkaline stability limitation and may open the way toward highly stable AEMs.

Hydration effects on thermal transitions and molecular mobility in Xanthan gum polysaccharides.

In this work, the xanthan gum (XG) polysaccharide is studied over a wide range of temperatures and water fractions 0 ≤ hw ≤ 0.70 (on a wet basis) by employing differential scanning calorimetry (DSC) and broadband dielectric spectroscopy (BDS). The investigation reveals that the critical water fraction for ice formation is about 0.35. Glass transition temperature (Tg) was determined through calorimetry experiments for all the samples studied. Water acts as a strong plasticizer, i.e., decreasing Tg, for water fractions up to about 0.35. A secondary (local) relaxation process is recorded in both dry and hydrated samples, which is sensitive to the presence of water molecules. This fact indicates that this process originates due to the orientation of small polar groups of the side chain, or/and due to the local main chain dynamics. Two types of long-range charge transport processes were resolved. The first is related to the conductive paths being formed via bulk-like ice structures (at high hydration levels), whereas the second can be attributed to proton mobility via the hydrogen bond (HB) network of non-freezing water existing in XG. Interestingly, this process is exactly the same in all the hydrated samples with hw > 0.25. With respect to the sample with hw = 0.27, a Vogel-Tammann-Fulcher (VTF)-like polarization process has also been recorded which seems to be related to long-range charge mobility via interconnected water clusters. As far as we are aware, this is the first time that XG is studied in terms of glass transition and molecular mobility over a wide range of hydration levels combining DSC and BDS techniques.

Examining the Water-Polymer Interactions in Non-Isocyanate Polyurethane/Polyhedral Oligomeric Silsesquioxane Hybrid Hydrogels.

Non-isocyanate polyurethane (NIPU) networks physically modified with octa(3-hydroxy-3-methylbutyldimethylsiloxy)POSS (8OHPOSS, 0-10 wt%) were conditioned in environments of different relative humidities (up to 97%) to study water-polymer interactions. The equilibrium sorption isotherms are of Brunauer type III in a water activity range of 0-0.97 and are discussed in terms of the Guggenheim (GAB) sorption model. The study shows that the introduction of 8OHPOSS, even in a large amount (10 wt%), does not hinder the water affinity of the NIPU network despite the hydrophobic nature of POSS; this is attributable to the homogenous dispersion of POSS in the polymer matrix. The shift in the urethane-derived carbonyl bands toward lower wavenumbers with a simultaneous shift in the urethane N-H bending bands toward higher wavenumbers exposes the breakage of polymer-polymer hydrogen bonds upon water uptake due to the formation of stronger water-polymer hydrogen bonds. Upon water absorption, a notable decrease in the glass transition temperature (Tg) is observed for all studied materials. The progressive reduction in Tg with water uptake is driven by plasticization and slaving mechanisms. POSS moieties are thought to impact slaving indirectly by slightly affecting water uptake at very high hydration levels.

Impact of deposited Pt particles on water channel connectivity and proton conductivity in proton exchange membranes: A molecular dynamics study

Deposition of platinum ions in the proton exchange membrane significantly affects the long-term stability and proton transport capacity of the membrane electrode assembly. In this study, the impacts of deposited Pt particles on the intrinsic properties of proton exchange membranes and its mechanisms are investigated using molecular dynamics simulation method. The effect of differently sized Pt particles on water channel connectivity and proton conductivity in proton exchange membranes under dry, normal, and saturated conditions was detailly discussed. The results reveal that Pt particles reduce water channel connectivity at low hydration level while increasing it at normal and high hydration levels. However, the enhancement mechanism is different. Moreover, proton conductivity was evaluated by examining the diffusion of hydronium ions and hydrogen bond dynamics. We found that the proton conduction performance of the membranes at low hydration levels is significantly reduced by Pt particles. We believe this study can promote the design of more robust and efficient proton exchange membranes.

Combination of Sodium Hyaluronate, Withania Somnifera Extract and Niacinamide Improves Hydration and Skin Tone – A Clinical Study

Background: Multiple moisturizing solutions with sodium hyaluronate, Withania sominifera, and niacinamide are commercially popular. Detailed clinical studies portraying their activity are not available. Objective: This study aims to study the clinical efficacy of a phyto-bioactive cream in improving skin hydration and tone with 4 weeks of continuous usage. Methodology: We conducted a non-comparative, single-blind study on 50 Asian female volunteers with Fitzpatrick skin types III and IV for 28 days. Cosmetic acceptability and safety of the product were established via self-evaluation questionnaires. The ability of the topical formulation in maintaining skin tone, hydration, and firmness was determined by instrumental analysis and smoothness by dermatologist evaluation. Results: A total of 46 subjects completed the study. High levels of skin hydration were noted instantaneously (+61.11%) and post continuous use of the product. Significant reduction in the appearance of age/dark spots (ITA°), Δ ITA°= 37.49% and increase in skin lightness (L) by 2.66% compared to baseline was observed in 4 weeks. More than 80% of the subjects reported an increase in skin firmness and smoothness in 4 weeks of twice-a-day product usage. Conclusion: Our study establishes the safety and acceptability of the phyto-bioactive cream. The efficiency of the combination of Withania somnifera extract, sodium hyaluronate, and niacinamide in improving skin hydration and tone has been proven.

A new supplementary cementitious material: Walnut shell ash

Partial replacement of supplementary cementitious materials (SCMs) for cement is an effective way to boost the long-lasting sustainability of cement-based construction. However, traditionally used SCMs are facing the problem of low availability. In response, a novel SCM – Walnut shell ash (WSA) – was identified. To validate the feasibility of using WSA as an SCM, frattini tests for pozzolanicity, setting time tests for workability, and compression and flexural strength tests for mechanical properties were conducted. The experimental results have demonstrated that cement paste incorporating no more than 20 % WSA possesses satisfactory pozzolanicity and setting times. Furthermore, this mix achieves an optimal long-term compressive strength of 83 MPa, which it maintains for up to a year. To reveal the hidden mechanisms behind the mechanical performance changes, microscopic and nanoscopic techniques, including scanning electron microscope and 29Si nuclear magnetic resonance, were conducted. Microscopically, the strength enhancement originates from the generation of fibrous C–S–H gel, high hydration level, and low porosity in cement paste with 20 % WSA. Nanoscopically, the changes in mechanical performance result from the shift of polymerization degree and the substitution of Al–Si in cement hydrates. These findings enrich the understanding of the role of WSA in manufacturing sustainable and durable cementitious materials that benefit both biomass waste management and cement industry decarbonization. In addition, the proposed multiscale assessment framework can be a tangible paradigm for screening new SCMs, thereby extending the horizon of sustainable materials research.

Abdominal obesity and hydration status as protective factors against mortality in older adults: A prospective study

ObjectivesThe aim of this study was to assess the association between different anthropometric and body composition techniques for defining obesity status and to investigate their clinical implications in older hospitalized patients, both during their hospitalization and after discharge. MethodsThis prospective study included patients ≥60 y of age. They were followed for 18 mo to assess mortality and hospital length of stay. Anthropometric measurements and body composition were evaluated, including body mass index (BMI), waist circumference, waist-to-height ratio, body fat percentage, total body water percentage, and muscle mass. These measurements are associated with prognosis and survival. ResultsA higher BMI, excessive body fat, higher total body water percentage, and abdominal obesity were associated with a lower risk for death (P < 0.05). Higher hydration levels were identified as an independent protective factor against mortality. Obesity, defined by body fat percentage, was associated with a shorter hospital stay (P < 0.05). ConclusionThe present study adds to the growing body of evidence supporting the existence of the obesity paradox in hospitalized older patients. Additionally, our novel finding reveals that higher levels of total body water percentage are associated with decreased odds of mortality. The study emphasizes the importance of considering other anthropometric measurements and body composition in addition to BMI, considering its limitations. These findings have important implications for health care providers when recommending changes in nutritional status for the older adult population.

How to avoid reactions to topical retinoid therapy

Topical retinoids are the first line treatment for mild to moderate acne. Although the drugs of this group are very effective in the treatment of acne, their use often causes irritant dermatitis – xerosis, peeling and other unpleasant symptoms. These adverse events reduce adherence to the therapy and, consequently, the effectiveness of the treatment. However, as shown by foreign clinical experience and our own observations, the use of moisturizers in combination with topical retinoid therapy can reduce the risk of irritant dermatitis. Preference should be given to moisturizers, whose components not only maintain a high level of skin hydration, but also can enhance the effect of the main drug.

Elucidating the impact mechanism of temperature and water content on thermal conductivity of hydrated Nafion membranes by molecular dynamics simulation

The thermal conductivity of the proton exchange membrane significantly affects the operating performance of the fuel cell. In this work, the impact of water content and temperature on thermal conductivity of hydrated Nafion membranes was investigated via molecular dynamics simulations and the influencing mechanism was explained from the perspective of interchain and intrachain heat transfer. The study shows that the thermal conductivity is mainly positively affected by water content, which is a result of the triple effect of hydrogen bonding acting as interchain heat transfer bridge, the stronger microphase separation allowing water to behave more like bulk water, and the decrease in the degree of chain torsion resulting in less phonon scattering along the chain. Particularly, we emphasized two crucial paths in which hydrogen bonding improves interchain heat transport. Furthermore, the temperature has little and slightly negative effects on thermal conductivity at low and high hydration levels, respectively. That is because, in low hydration levels, the incomplete hydrogen bond network is hardly influenced, but the bridging effect is suppressed and intrachain heat transfer capacity is reduced in high hydration levels. We believe this study can broaden the design basis of high temperature polymer electrolyte membranes.

Interplay of Hydration and Protonation Dynamics in the K-Channel of Cytochrome c Oxidase.

Cytochrome c oxidase is a membrane protein of the respiratory chain that consumes protons and molecular oxygen to produce water and uses the resulting energy to pump protons across the membrane. Our molecular dynamics simulations with an excess proton located at different positions in one of the proton-conducting channels, the K-channel, show a clear dependence of the number of water molecules inside the channel on the proton position. A higher hydration level facilitates the formation of hydrogen-bonded chains along which proton transfer can occur. However, a sufficiently high hydration level for such proton transport is observed only when the excess proton is located above S365, i.e., the lower third of the channel. From the channel entrance up to this point, proton transport is via water molecules as proton carriers. These hydronium ions move with their surrounding water molecules, up to K362, filling and widening the channel. The conformation of K362 depends on its own protonation state and on the hydration level, suggesting its role to be proton transport from a hydronium ion at the height of K362 to the upper part of the channel via a conformational change. The protonation-dependent conformational dynamics of E101 at the bottom of the channel renders proton transfer via E101 unlikely. Instead, its role is rather that of an amplifier of H96's proton affinity, suggesting H96 as the initial proton acceptor.

A comprehensive comparison of facial skin hydration based on capacitance and conductance measurements in Chinese women.

The aim of this study was to compare the data of conductance and capacitance measurements of facial skin hydration and to evaluate and discuss the advantages and disadvantages of the different approaches. We measured skin capacitance (Corneometer® CM 825) and skin conductance (Skicon-200EX®) on 30 pre-defined facial sites of 125 Chinese women, resulting in 3750 readings per device. The data were analysed and compared, and continuous colour maps were generated on a 3D avatar for capacitance, conductance, relative difference (Δ%) and correlation (R-value) by interpolating between the individual readings and converting the values to colours. This visualization allows a better interpretation of the results. The complexity of facial skin hydration is revealed by this approach. The similarities and discrepancies in the facial hydration maps are clearly apparent. Due to the superiority of the Skicon in measuring high hydration levels, differences in skin hydration were evident on the forehead compared with the Corneometer maps, which may be related to the more superficial measurement of the Skicon within the stratum corneum. Conversely, a greater understanding of the complexity of facial skin hydration in the nasolabial fold was obvious when using the Corneometer. The best congruence between the instruments was found at two specific but separated facial areas, one around the inner eye region and the other one on a line between the nasolabial sulcus and the oblique, lateral jaw. Interestingly, the data were not normally distributed for both instruments and they had opposite skews. All facial clusters were statistically different from each other (p< 0.001), except the cheek and jaw for the Skicon. Larger than expected percentage coefficients of variance were found for the Corneometer on some facial sites that might be explainable by differences in stratum corneum physiology and biochemistry. Corneometer values of 48 AU and Skicon values of 132 μS were taken as the cutoff for normally hydrated facial skin. Both devices have their advantages and disadvantages suggesting that bio-instrumental measurement of skin hydration is actually more complicated than commonly thought and that the different facial zones and the use of multiple instrumentation have not been adequately considered.

Molecular Dynamics Modeling Based Investigation of the Effect of Freezing Rate on Lysozyme Stability.

The stability of protein drug products frozen during fill finish operations is greatly affected by the freezing rate applied. Non-optimal freezing rates may lead to the denaturation of protein's complex macromolecular conformation. However, limited work has been done to address the effect of different freezing rates on protein stability at nano-scale level. The stability of a model protein, lysozyme, was investigated at atomic and molecular scale under varying freezing rates and moving ice-water interface. Ice seeding approach was adopted to initiate ice formation in this present simulation. The faster freezing rate (11-12K/490ns) applied resulted in overall smaller ice fraction within the simulation box with a larger freeze-concentrated liquid (FCL) region. Consequently, the faster freezing rate better maintained protein stability with less secondary structure deviations, higher hydration level and structural compactness, and less fluctuations at individual residues than observed following slow (5-6K/490ns) and medium (7-8K/490ns) freezing rates. The present study also identified the residues near and within helices 3, 6, 7, and 8 dominate the structural instability of the lysozyme at 247K freezing temperature. For the first time, ice formation in therapeutic protein solution was studied "non-isothermally" at different freezing rates using molecular dynamics simulations. Thus, a good understanding of freezing rates on protein instability was revealed by applying the developed computational model.