High Viscosity Research Articles

The effect of anti-agglomerant tween on the thermal and rheological properties of TBAF semi-clathrate hydrate slurry used for cold storage systems

Hydrate, as a phase change cold storage material, can form the slurry with certain fluidity, enabling convective heat transfer during both the heat absorption and heat release stages (cold storage or refrigeration), with high heat transfer efficiency. However, high viscosity and significant flow pressure losses are the principal challenges limiting its advancement. The paper selected four non-ionic surfactants as hydrate anti-agglomerants (Tween 20, 40, 60, 80) and utilized DSC to examine their effects on the thermal properties of TBAF semi-clathrate hydrate slurry at three theoretical hydrate concentrations (with mass fraction of 0.60, 0.70, and 0.80). Additionally, it measured the viscosity variation during the endothermic dissociation stage of the TBAF hydrate slurry and calculated the flow pressure losses in hydrate slurries within various pipe diameters. The results revealed that the presence of Tween increased the hydrate growth within the slurry, resulting in a higher available phase change enthalpy. Tween 80 demonstrated the most significant increase in enthalpy increasing effect, with an available phase change enthalpy ranging from 128.08 to 170.03 kJ/(kg·slurry) and an increase in enthalpy of 52.14 % to 91.62 %. For TBAF hydrate slurries with the theoretical hydrate mass fraction of 0.60, the addition of Tween 20 or Tween 80 significantly reduced viscosity, dropping to between 57.6 mPa·s and 116 mPa·s, and reducing viscosity by 43.4 % to 71.9 %. Furthermore, most flows with anti-agglomerants were in the laminar regime. The addition of Tween 20 and Tween 80 achieved the maximum reduction in flow pressure loss per unit length, with the highest reduction being 80.2 % (0.11 kPa/m) and 71.1 % (0.15 kPa/m), respectively. Both the phase change enthalpy of the hydrate and the viscosity of the hydrate slurry impacted the flow pressure drop within pipes. Increasing phase change enthalpy and reducing viscosity are effective strategies for mitigating flow pressure drop.

Emulsifying and interfacial properties of glutenin processed by pH-shifting treatment

Modifying and improving protein functionality is crucial for expanding the application of proteins in the food industry. The aim of this study was to investigate the effect of pH-shift treatments on the emulsifying and interfacial properties of glutenin (Glu). Glu was exposed to acidic (pH 1–3) and basic (pH 10–13) pH values for 4 h and subsequently neutralized for refolding. The pH-shifting treatments significantly improved Glu surface wettability with three-phase contact angle from 66.21 ± 2.31° to 91.4 ± 0.88°. The alkali shift treatment resulted in samples with larger Kdiff values. The treated samples also showed amplitude and frequency dependence in their E, Ev, and Ed values, with higher E and Ed values indicating an elastic membrane at the interface. Emulsions prepared from Glu treated with alkali shift treatment exhibited smaller particle size, larger ζ-potential, and more stable storage properties. The rheological results indicated higher viscosity, thixotropy and creep of emulsions prepared from alkali shift treated Glu. In conclusion, treatment of Glu with alkali shift resulted in significant improvements in emulsifying and interfacial properties, suggesting that Glu may be a more promising ingredient for use in food.

Oxidation of SiC fibers in water vapor

AbstractThe current study focuses on the role of composition in the oxidation behavior of three commercial SiC fibers (Hi‐Nicalon Type S (HNS), Tyranno ZMI, and Tyranno SA) in a steam‐containing environment at 1000°C. Oxide scales that form on each of the three fiber types differ in morphology, microstructure, and composition. Differences are attributed to O and C contents, crystallinity, and minor alloying elements. Oxidation kinetics of the HNS fibers follow linear/parabolic (Deal–Grove) predictions over the entire range of exposure times (to 96 h). In the other fibers, deviations from the initial linear/parabolic trend occur when either the scale crystallizes in situ during oxidation (as on the ZMI fibers) or when structural changes internal to the fiber alter the chemical environment at the scale/fiber interface (on the SA fibers). Adaptations of the linear/parabolic oxidation model are used to rationalize the growth kinetics in the latter two cases. Collectively, the data and analyses indicate a two‐fold difference in permeabilities of crystalline and amorphous silica scales. Inferred interface reaction rates further suggest faster oxidation for fibers with greater amounts of amorphous Si–O–C. Moreover, crystalline scales are more prone to cracking, because of their higher viscosity at elevated temperatures and a deleterious phase transformation upon cooling.

Investigating the Inhibitory Factors of Sucrose Hydrolysis in Sugar Beet Molasses with Yeast and Invertase

Sugar beet molasses is a low-value byproduct from the sugar industry. It contains significant amounts of sucrose (approx. 50% (w/w)), which can be used for many different applications, for example, as feedstock for the production of fuel (as ethanol) and biobased chemicals such as 5-hydoxymethyl furfural (HMF). To produce platform chemicals, sucrose is hydrolyzed into its monomeric C6 sugars: glucose and fructose. When comparing the hydrolysis rates of molasses with a pure sucrose solution, the specific reaction rate is much slower (Qp/x,60min = 93 and 70 gprod L−1 h−1 gcell−1 for pure sucrose and crude molasses, respectively) at the same sucrose concentration (300 g/L) and process conditions. To clarify why molasses inhibits the enzymatic hydrolysis rate, the influence of its viscosity and inorganic and organic composition was investigated. Also, the effects of molasses and treated molasses on pure enzymes, invertase (from Saccharomyces cerevisiae, 0.05 mg/mL), compared with hydrolysis using whole cells of Baker’s yeast (3 mg/mL), were tested. The results indicate an inhibitory effect of potassium (Qp/x,60min = 76 gprod L−1 h−1 gcell−1), generally at high salt concentrations (Qp/x,60min = 67 gprod L−1 h−1 gcell−1), which could be correlated to the solution’s high salt concentrations and possibly the synergistic effects of different ions when applying concentrations that were four times that in the molasses. Also, the viscosity and sucrose purity seem to have an effect, where pure sucrose solutions and thick juice from the sugar mill yielded higher hydrolysis rates (Qp/x,60min = 97 gprod L−1 h−1 gcell−1) than molasses-type solutions with a higher viscosity (Qp/x,60min = 70–74 gprod L−1 h−1 gcell−1). Attempting to further understand the effects of different components on the invertase activity, an in silico investigation was performed, indicating that high salt concentrations affected the binding of sucrose to the active site of the enzyme, which can result in a lower reaction rate. This knowledge is important for future scale-up of the hydrolysis process, since reduced hydrolysis rates require larger volumes to provide a certain productivity, requiring larger process equipment and thereby higher investment costs.

Insights into the structuring ability of two brown seaweeds (Laminaria digitata and Saccharina latissima) for applications as natural texturisers

Seaweeds represent a potential source of novel food products with enhanced sustainability. However, in order to use seaweeds as ingredients more knowledge is needed regarding the impact of processing on their structuring ability and functionality. We report on the structure and rheology of aqueous dispersions of two species of brown seaweed, namely: Laminaria digitata and Saccharina latissima, prepared by different food processing techniques. High pressure homogenisation disrupted seaweed cell walls, leading to stable weak gels characterised by smaller particle size compared to untreated samples. Thermal treatment (70 °C 1 h), applied prior or during shear treatment, did not impact the particle size, however, it led to serum phases with higher viscosities. This was related to an increased solubilisation of polysaccharides from the cell walls into the serum, as reflected by chemical analysis and small angle X-ray scattering (SAXS). Furthermore, although in terms of rheological behaviour and particle size, both species showed similar response to food processing conditions, the cell wall nanostructure of L. digitata was modified to a larger extent compared to S. latissima, which was linked to a higher solubilisation of polysaccharides. These insights regarding functionalisation of brown seaweed dispersions provide the scientific knowledge to use whole seaweed as natural structurants for future food and other technological applications.

Rheological and surface properties of biodegradble films of Prosopis juliflora (Sw.) DC. Galactomannan and Citric Acid

This work aimed to evaluate the rheological and surface properties of biodegradable galactomannan films from Prosopis juliflora (Sw.) DC. cross-linked by citric acid. Initially, galactomannan was obtained through ethanolic extraction, and formulations with 10 to 20% citric acid, glycerin, and corn starch were prepared. The bioplastics were characterized by contact angle, rheology, zeta potential, surface roughness. When evaluating the contact angle, the filmogenic formulations containing galactomannan, starch, and citric acid, F6 and F7, had lower hydrophilicity and higher viscosity with pseudoplastic behavior, typical of polysaccharides. The zeta potential was not able to translate the stability of the filmogenic solutions studied in this work. The results obtained prove the positive influence of citric acid as a crosslinking agent on the properties of galactomannan films from Prosopis juliflora (Sw) DC.

Organic Solvent Boosts Charge Storage and Charging Dynamics of Conductive MOF Supercapacitors.

Conductive metal-organic frameworks (c-MOFs) and ionic liquids (ILs) have emerged as auspicious combinations for high-performance supercapacitors. However, the nanoconfinement from c-MOFs and high viscosity of ILs slow down the charging process. This hindrance can, however, be resolved by adding solvent. Here, we performed constant-potential molecular simulations to scrutinize the solvent impact on charge storage and charging dynamics of MOF-IL-based supercapacitors. We find conditions for >100% enhancement in capacity and ∼6 times increase in charging speed. These improvements were confirmed by synthesizing near-ideal c-MOFs and developing multiscale models linking molecular simulations to electrochemical measurements. Fundamentally, our findings elucidate that the solvent acts as an "ionophobic agent" to induce a substantial enhancement in charge storage, and as an "ion traffic police" to eliminate convoluted counterion and co-ion motion paths and create two distinct ion transport highways to accelerate charging dynamics. This work paves the way for the optimal design of MOF supercapacitors. This article is protected by copyright. All rights reserved.

Coal gangue in asphalt pavement: A review of applications and performance influence

The comprehensive utilization of coal gangue is low, and this causes serious environment problems and security risks. The physical and chemical properties of coal gangue were analyzed in this paper, and the estimated value of different chemical components of coal gangue was counted. The physical properties of coal gangue aggregate were analyzed, and performance and its influencing factors of base course mixture with coal gangue aggregate were studied. The influence of coal gangue powder and coal gangue aggregate on performance of asphalt mortar and asphalt mixture was analyzed, and possible influencing factors and function mechanism were discussed. The results showed that heavy metal elements of coal gangue applied into asphalt pavement is not seeped out. The crushing value, water absorption and flat elongated particles content of coal gangue aggregate are generally high, but the compressive strength of base course with coal gangue aggregate is verified to meet the strength requirement. The performance, volume stability and durability of base course with coal gangue aggregate are closely related to aggregate gradation, the type and dosage of cementations materials and aggregate. The high temperature performance, temperature susceptibility and viscosity of asphalt mortar are improved by the addition of different coal gangue powder, and improvement effect of activated coal gangue powder on asphalt mortar performance is better. The low temperature performance and adhesion property of asphalt mortar with chemical activated coal gangue powder are improved. The physical reaction between asphalt and different coal gangue powder is only taken place. The temperature stability of asphalt mixture with coal gangue coarse aggregate has achieved the specification requirement. The water stability and low temperature fracture performance of asphalt mixture with fine aggregate replaced by coal gangue are improved. However, the high temperature performance of above mixture is lower than conventional hot mix asphalt mixture. The research results will provide reference for coal gangue applied into asphalt pavement.

Secondary organic aerosols derived from intermediate-volatility n-alkanes adopt low-viscous phase state

Abstract. Secondary organic aerosol (SOA) derived from n-alkanes, as emitted from vehicles and volatile chemical products, is a major component of anthropogenic particulate matter, yet the chemical composition and phase state are poorly understood and thus poorly constrained in aerosol models. Here we provide a comprehensive analysis of n-alkane SOA by explicit gas-phase chemistry modeling, machine learning, and laboratory experiments to show that n-alkane SOA adopts low-viscous semi-solid or liquid states. Our study underlines the complex interplay of molecular composition and SOA viscosity: n-alkane SOA with a higher carbon number mostly consists of less functionalized first-generation products with lower viscosity, while the SOA with a lower carbon number contains more functionalized multigenerational products with higher viscosity. This study opens up a new avenue for analysis of SOA processes, and the results indicate few kinetic limitations of mass accommodation in SOA formation, supporting the application of equilibrium partitioning for simulating n-alkane SOA formation in large-scale atmospheric models.

Pharmacokinetics and Safety of Intramuscular Injectable Benzathine Penicillin G in Japanese Healthy Participants.

An intramuscular (IM) suspension of benzathine penicillin G (BPG) has been used as first-line therapy for the treatment of syphilis worldwide since its approval in the 1950s. However, there are limited reports about the pharmacokinetics of BPG. A Phase 1 study was conducted on eight Japanese healthy participants to investigate the pharmacokinetics (samples collected predose to 648 h post-dose) and safety of 2.4 million units of BPG after a single IM injection. Following administration, penicillin G, the active moiety of BPG, was absorbed slowly from the injection site with a median time to Cmax (tmax) of 48 h post-dose. After the achievement of Cmax, concentrations of penicillin G declined slowly in a monophasic fashion with a mean apparent terminal half-life of 189 h. Geometric mean AUCinf and Cmax were 50770 ng•h/mL and 259 ng/mL, respectively. Median time (range) above the well-accepted therapeutic concentration (18 ng/mL) for syphilis treatment was 561 h (439-608 h [18-25 days]), which reached and exceeded the necessary duration of 7-10 days for syphilis treatment. Two participants were underdosed with residual drug left in the syringe due to the high viscosity of the drug product. Only one (12.5%) participant reported a mild adverse event of nasopharyngitis, which was considered not related to the study treatment. The study results supported BPG approval in Japan as an option for syphilis treatment.

Optimisation of Synchronous Grouting Mix Ratio for Shield Tunnels

During shield construction in underground spaces, synchronous grouting slurry is poured between the surrounding rock and tunnel lining to ensure stability. For synchronous grouting slurries, few studies have investigated the relationship between the rheological parameters and physical properties, grout-segregation mechanism, and anti-segregation performance. Therefore, we explored the relationships between the slurry rheological parameters, segregation rate, and bleeding rate. Cement, sand, fly ash, and bentonite were used to prepare the slurry, and the effects of different polycarboxylate water-reducing agents and dispersible latex powder dosages were studied. The rheological parameters of 16 groups of uniformly designed slurries were tested, and the data were fit using the Herschel–Bulkley model. The optimal mix ratio lowered the slurry segregation rate, and its rheological behaviour was consistent with the Herschel–Bulkley fluid characteristics. High-yield-shear-stress synchronous grouting slurries with high and low viscosity coefficients were less likely to bleed and segregate, respectively. The optimised slurry fluidity, 3 h bleeding rate, 24 h bleeding rate, segregation rate, coagulation time, and 28 days compressive strength were 257.5 mm, 0.71%, 0.36%, 3.1%, 6.7 h, and 2.61 MPa, respectively, which meet the requirements of a synchronous grouting slurry of shield tunnels for sufficiently preventing soil disturbance and deformation in areas surrounding underground construction sites.

Physical and oxidative stability of flaxseed oil-in-water emulsions prepared by natural lignin-carbohydrate complex

Flaxseed oil, rich in α-linolenic acid, plays a crucial role in various physiological processes. However, its stability presents certain challenges. In this study, the natural lignin-carbohydrate complex (LCC) was used to prepare the physical and oxidative stability of flaxseed oil-in-water emulsions. The LCC was characterized by HPLC, GPC, and FT-IR. The stability of emulsions was evaluated by viscosity, modulus, and micro-morphology changes. Then, the oxidation products were monitored by UV–vis spectrophotometer and HPLC. The results revealed that the high internal phase emulsion (HIPE) was successfully prepared with 2.5 wt% LCC at an oil/water ratio of 75/25 (v/v). Small droplet size (13.361 μm) and high viscosity (36,500 mPa·s) were found even after 30-day storage. Steric interactions of the LCC play a crucial role in ensuring stability, intricately linked to the interfacial properties of the emulsion. Meanwhile, the oxidative stability of α-linolenic acid in the encapsulated flaxseed oil was significantly higher than that in the bulk flaxseed oil. The results revealed that the LCC as a suitable emulsifier opens a new window for the storage of functional lipids rich in polyunsaturated fatty acids.

Cost-effective enhancement of high viscosity modified bitumen anti-aging properties using organic layered double hydroxide/fume silica nanoparticles composite nanomaterials

High-viscosity modified bitumen (HVMB) is prone to thermal-oxidative and photooxidative aging, resulting in pavement diseases. The use of conventional Nano-modifiers to enhance the aging resistance of bitumen is often hindered by high costs, limiting their adoption in widespread applications. This study aims to evaluate the impact of a cost-effective Multi-Dimensional Nano-Composite (MDNC) modifier on the durability of HVMB, which includes organically modified Layered Double Hydroxides (OLDHs) and Fumed Silica Nanoparticles (FSNPs). Additionally, Zero-Dimensional Nanomaterials (ZDNs) such as FSNPs, Nano-SiO2, or Nano-TiO2, in combination with various MDNC modifiers consisting of OLDHs and ZDNs, were also utilized as comparative anti-aging modifiers for HVMB binders. FTIR, XRD, and contact angle tests indicate that LDHs modified with KH560 (OLDHs) exhibit improved hydrophobicity and increased interlayer distance. The temperature sweep test of the unaged binders and the FESEM test of the Nano-modifier indicate that the branched network structure of the FSNPs significantly enhances the high-temperature elasticity of the HVMB binders. Rheological test results have shown that both ZDNs and MDNC modifiers can delay the changes in rheological parameters after aging. Combining FTIR and SARA (Saturates, Aromatics, Resins, Asphaltenes) results, it was found that the combination of OLDHs/FSNPs synergistically inhibited the increase in the content of heavy components in bitumen during thermal oxygen and ultraviolet aging. The enhancement of the HVMB's thermal oxidation aging resistance by OLDHs/FSNPs composite modifiers is primarily due to the multidimensional structure of the composite nanomaterial, which effectively prevents the penetration of oxygen molecules. Meanwhile, the improvement in resistance to ultraviolet aging is mainly due to the absorption and scattering characteristics of FSNPs. Therefore, OLDHs/FSNPs are demonstrated to be a cost-effective multidimensional nano-modifier.

Role of Resistant Starch in Food and Healthcare Industry: A Review

Starches are complex polysaccharides which are notorious to create glucose load in diet. But the advancements in the fields of food chemistry have come up with a fact that there are some starches which can release glucose in controlled manner. They are known as resistant starches. They are basically four types depending upon sources of origin: Type I physical inaccessible starch (RS1), Type II that inhibit the action of enzymes (RS2), Type III retrograded starch (RS3) and Type IV chemically modified starch (RS4). Resistant Starches now a days are used in many sectors of food industry. It has unique physical and chemical properties such as high viscosity, formation of gel and water-binding capacity that make it valuable new food product development. This has enhanced its usage in food industries. The bland flavour and transparency in colour of RS with low water holding property is making them a good encapsulating medium in microencapsulation of probiotics. They are known to have low glycemic index and good impact on bowel health by acting as prebiotic to the gut microflora. Their demand in the food industry is arisen to the extent that normal starches are retrograded to convert them to RS. Impact of dry and wet heat methods of cooking on content of resistant starches in several food products have been established by many studies.

Influences of clean fracturing fluid viscosity and horizontal in-situ stress difference on hydraulic fracture propagation and morphology in coal seam

The viscosity of fracturing fluid and in-situ stress difference are the two important factors that affect the hydraulic fracturing pressure and propagation morphology. In this study, raw coal was used to prepare coal samples for experiments, and clean fracturing fluid samples were prepared using CTAB surfactant. A series of hydraulic fracturing tests were conducted with an in-house developed triaxial hydraulic fracturing simulator and the fracturing process was monitored with an acoustic emission instrument to analyze the influences of fracturing fluid viscosity and horizontal in-situ stress difference on coal fracture propagation. The results show that the number of branched fractures decreased, the fracture pattern became simpler, the fractures width increased obviously, and the distribution of AE event points was concentrated with the increase of the fracturing fluid viscosity or the horizontal in-situ stress difference. The acoustic emission energy decreases with the increase of fracturing fluid viscosity and increases with the increase of horizontal in situ stress difference. The low viscosity clean fracturing fluid has strong elasticity and is easy to be compressed into the tip of fractures, resulting in complex fractures. The high viscosity clean fracturing fluids are the opposite. Our experimental results provide a reference and scientific basis for the design and optimization of field hydraulic fracturing parameters.

Innovative production of phosphoric acid-hydrolyzed chitin nanocrystals for Pickering emulsion stabilization

Addressing the need for sustainable emulsification methods, this study introduces a novel approach by producing chitin nanocrystals (PA-ChNCs) through solid-state hydrolysis using minimal phosphoric acid. The aim was to assess the capability of PA-ChNCs to stabilize Pickering emulsions. Our investigation revealed a pH-responsive variation in particle size and surface charge of PA-ChNCs, critical for emulsion stability. They varied from 321.5 ± 10.5 nm to 2366.7 ± 171.6 nm and from 33.7 ± 1.2 mV to −19.9 ± 1.4 mV, respectively, when pH increased from 3 to 10. Notable, emulsions with a 50% oil-to-water (O:W) ratio presented larger droplets with increased viscosity, enhancing stability over 30 days significantly. In contrast, higher PA-ChNCs concentrations (2.0 wt%) at pH 10 resulted in smaller droplets and higher viscosity, indicating superior emulsion stability. This research contributes novel insights into eco-friendly emulsifier development, utilizing seafood byproducts and underscoring the use of PA-ChNCs as effective Pickering emulsion stabilizers in food applications.

The influence of viscous slab rheology on numerical models of subduction

Abstract. Numerical models of subduction commonly use diffusion and dislocation creep laws from laboratory deformation experiments to determine the rheology of the lithosphere. The specific implementation of these laws varies from study to study, and the impacts of this variation on model behavior have not been thoroughly explored. We run simplified 2D numerical models of free subduction in SULEC, with viscoplastic slabs following (1) a diffusion creep law, (2) a dislocation creep law, and (3) both simultaneously, as well as several variations of model 3 with reduced resistance to bending. We compare the results of these models to a model with a constant-viscosity slab to determine the impact of the implementation of different lithospheric flow laws on subduction dynamics. In creep-governed models, higher subduction velocity causes a longer effective slab length, increasing slab pull and asthenospheric drag, which, in turn, affect subduction velocity. Numerical and analogue models implementing constant-viscosity slabs lack this feedback but still capture morphological patterns observed in more complex models. Dislocation creep is the primary deformation mechanism throughout the subducting lithosphere in our models. However, both diffusion creep and dislocation creep predict very high viscosities in the cold core of the slab. At the trench, the effective viscosity is lowered by plastic failure, rendering effective slab thickness the primary control on bending resistance and subduction velocity. However, at depth, plastic failure is not active, and the viscosity cap is reached in significant portions of the slab. The resulting high slab stiffness causes the subducting plate to curl under itself at the mantle transition zone, affecting patterns in subduction velocity, slab dip, and trench migration over time. Peierls creep and localized grain size reduction likely limit the stress and viscosity in the cores of real slabs. Numerical models implementing only power-law creep and neglecting Peierls creep are likely to overestimate the stiffness of subducting lithosphere, which may impact model results in a variety of respects.

Physicochemical Properties and Sensory Evaluation of Yogurt Formulated with Pineapple and Roselle Fibres

Functional food promotes specific health benefits and lowers the risk of acquiring health problems. Probiotics, prebiotics, and omega-3 fatty acids were added to functional food to enhance the nutritional value of the food itself. Yogurt is one of the examples of widely produced probiotic products. Concerns arise due to reduced fibre in refined food, leading to an increased risk of colon cancer and gastrointestinal diseases. Fruit-based yogurts with artificial additives were developed to cater to consumer preferences but were found to give negative health effects. To address this, yogurt with natural fibre sources like roselle and pineapple fibres was formulated, providing health-promoting components, flavor, and color without resorting to artificial additives. Current work focused on physicochemical properties and sensory evaluation of yogurt formulated with roselle and pineapple fibres. The concentration of roselle and pineapple fibres added were varied and their effect on the physicochemical properties of yogurt namely pH, viscosity, antioxidant activity, and syneresis were investigated. The evaluation was conducted at four different storage periods, which were on the 7th, 14th, 21st, and 28th days of yogurt storage. A sensory evaluation was also tested. The pH of formulated yogurt decreased as the concentration of roselle, and pineapple fibre increased. The highest viscosity was recorded for yogurt formulated with 8% pineapple fibre. Yogurt enriched with 8% roselle fibre demonstrated a superior antioxidant content. For sensory evaluation, yogurt with 4% pineapple fibre received the highest score regarding overall acceptability. The incorporation of roselle and pineapple fibre into yogurts formulation can be an alternative method in adding dietary fibres to the dairy products.

Cost-effectiveness of restorative treatments for permanent molars with severe molar incisor hypomineralization: perspectives for the Brazilian public health system.

To undertake a cost-effectiveness analysis of restorative treatments for a first permanent molar with severe molar incisor hypomineralization from the perspective of the Brazilian public system. Two models were constructed: a one-year decision tree and a ten-year Markov model, each based on a hypothetical cohort of one thousand individuals through Monte Carlo simulation. Eight restorative strategies were evaluated: high viscosity glass ionomer cement (HVGIC);encapsulated GIC; etch and rinse adhesive + composite; self-etch adhesive + composite;preformed stainless steel crown; HVGIC + etch and rinse adhesive + composite; HVGIC + self-etch adhesive + composite, and encapsulated GIC + etch and rinse adhesive + composite. Effectiveness data were sourced from the literature. Micro-costing was applied using 2022 USD market averages with a 5% variation. Incremental cost-effectiveness ratio (ICER), net monetary benefit (%NMB), and the budgetary impact were obtained. Cost-effective treatments included HVGIC (%NMB = 0%/0%), encapsulated GIC (%NMB = 19.4%/ 19.7%), and encapsulated GIC + etch and rinse adhesive + composite (%NMB = 23.4%/ 24.5%) at 1year and 10years, respectively. The benefit gain of encapsulated GIC + etch and rinse adhesive + composite in relation to encapsulated GIC was small when compared to the cost increase at 1year (gain of 3.28% and increase of USD 24.26) and 10years (gain of 4% and increase of USD 15.54). Within the horizon and perspective analyzed, the most cost-effective treatment was encapsulated GIC restoration. This study can provide information for decision-making.

Utilization of Blackmouth Catshark (Galeus melastomus) Skins as an Alternative Source of Gelatin: Extraction and Physicochemical Characterization in Comparison to Porcine Skin Gelatin

The present study investigated the potential use of blackmouth catshark (Galeus melastomus) skins for gelatin production by employing a combined alkaline and acidic process. The yield of dry gelatin was relatively high (13.95%), showing a high protein content (87.80%), but low moisture (10.64%), ash (1.34%) and lipid (0.03%) contents, on a wet weight basis. Fish skin gelatin showed better color properties (>L*, <+b* values) than porcine skin gelatin and exhibited similar gel strength (315.4 g) and higher viscosity (5.90 cP) than the latter (p < 0.05). Although the electrophoretic study revealed that fish skin gelatin was degraded to a lesser extent than its mammalian counterpart, the resulting fish skin gelatin gels melted at a significantly lower temperature (Tm = 21.5 °C), whereas the reverse process (i.e., gelling) also occurred at a lower temperature (Ts = 10.6 °C) and required more time (ts = 29.5 min) compared to porcine skin gelatin gels (Tm = 30.4 °C, Ts = 19.4 °C and ts = 20.7 min). These differences were attributed to the different imino acid content, which was greater in mammalian gelatin (p < 0.05). The results suggested that the skins from blackmouth catshark can be potentially used as an alternative raw material for gelatin production, which will fill the needs of more diverse cultures that do not consume pork- or cow-related products.