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ACS Omega Jun 2024The modeling of ceramics with complex geometric structures currently depends on the handcrafted mode, with long cycles, high costs, and low efficiency; additive...
The modeling of ceramics with complex geometric structures currently depends on the handcrafted mode, with long cycles, high costs, and low efficiency; additive manufacturing (AM) technology can solve this problem well. Herein, the porcelain clay paste was successfully prepared for the direct ink writing (DIW) 3D printing process of ceramics with complex geometric structures, and the effects of sodium citrate (SC) content on the rheological properties and DIW 3D printability of the porcelain clay paste were investigated in detail. The SC has a vital role in the rheological behavior of porcelain clay paste. Adding SC increases the absolute zeta potential and decreases the viscosity of the paste, while a high SC content will lead to a low storage modulus of the paste. The porcelain clay paste with an SC content of 0.05% and a paste solid content of 75% possesses suitable rheological properties and a storage modulus for DIW 3D printing. The as-prepared porcelain clay paste has high DIW 3D printability at a pressure of 0.5 MPa, and a 3D-printed green body with a well-densified structure can be achieved. After being sintered, the 3D-printed ceramic exhibits high densification and mechanical properties. A green body with complex geometric structures is quickly and precisely modeled by the DIW 3D printing process with the resultant porcelain clay paste as the raw material. This work provides a practical approach to rapidly fabricating ceramics with complex geometrical structures.
PubMed: 38911716
DOI: 10.1021/acsomega.4c02543 -
Cureus May 2024Cases of macadamia nut-induced anaphylactic shock have been rarely reported. We report the case of a three-year-old girl with anaphylactic shock who presented with...
Cases of macadamia nut-induced anaphylactic shock have been rarely reported. We report the case of a three-year-old girl with anaphylactic shock who presented with generalized erythema two hours after ingesting macadamia nuts. She required two doses of intramuscular adrenaline for the treatment of anaphylactic shock. The diagnosis of macadamia nut allergy was confirmed by a prick-by-prick skin test using roasted and raw macadamia nut paste extracts and elevated serum macadamia nut-specific immunoglobulin E (IgE) levels. Appropriately using a prick-by-prick test may contribute to accurately diagnosing macadamia nut allergy, thus preventing the unnecessary avoidance of other nuts. Considering the potential for severe shock induced by macadamia nut allergy, vigilant monitoring of blood pressure changes is imperative in children presenting with immediate-type allergic reactions, such as vomiting and skin symptoms, following macadamia nut ingestion.
PubMed: 38910662
DOI: 10.7759/cureus.60858 -
RSC Advances Jun 2024All-solid-state Na polymer batteries are desired as the next generation of high-capacity batteries owing to their high safety and abundant resources. However, the...
All-solid-state Na polymer batteries are desired as the next generation of high-capacity batteries owing to their high safety and abundant resources. However, the degradation of the positive electrode/electrolyte interface with cycling leads to a decrease in capacity and a significant increase in interfacial resistance. In this study, to suppress the interfacial degradation, we prepared positive electrode sheets through a combination of simple mixing and pasting with the addition of binders and conductive additives, using NaCoO coated with two types of inorganic oxides as the active material. The influence of the coatings on the electrochemical properties of the fabricated all-solid-state Na polymer battery was investigated by performing constant-current charge-discharge tests, and the coating morphology was characterized by electron microscopy and spectroscopic measurements. Compared with the non-coated positive electrode, the coated electrodes not only enhanced the battery capacity and improved the cycling characteristics but also effectively suppressed the formation of byproducts during charge-discharge cycling, owing to the electrochemical stability and Na conductivity of the inorganic oxide coatings. Moreover, despite the chemically unstable properties of powdered NaCoO, the application of this mixing method effectively suppressed its degradation.
PubMed: 38903663
DOI: 10.1039/d4ra02957g -
BioMed Research International 2024In a research experiment, 48 male Wistar rats were anesthetized and second-degree burns were induced on their backs. The rats' wounds were then uniformly inoculated with...
MATERIALS AND METHODS
In a research experiment, 48 male Wistar rats were anesthetized and second-degree burns were induced on their backs. The rats' wounds were then uniformly inoculated with MRSA. Various treatments were applied to the burn wounds daily, including Myrtus ointment, silver nanoparticles, silver nanoparticles-Myrtus ointment, silver sulfadiazine-Myrtus ointment, silver sulfadiazine 1%, mupirocin ointment, and a positive control. The study measured the antimicrobial effects, wound area, percentage of wound healing, antioxidant capacities, malondialdehyde, and nitric oxide concentrations in the serum of the rats. Data analysis was performed using GraphPad software, with one-way ANOVA and Tukey's tests used to determine the statistical significance of the results.
RESULTS
Rats treated with Myrtus ointment, silver nanoparticles-Myrtus ointment, and mupirocin had reduced bacterial growth compared to the positive control group, nanoparticle ointment, and silver sulfadiazine ( < 0.05). The wound area of the Myrtus ointment group decreased significantly on the seventh and fourteenth days, as well as the level of MDA and nitric oxide, compared to the other groups. In Myrtus and silver sulfadiazine-Myrtus ointment increased the thickness of the epidermis and dermis compared to the other groups.
CONCLUSION
Based on the anti-inflammatory, antimicrobial, and wound healing properties of Myrtus, with further studies, an ointment of this plant may be used as a main or complementary treatment for burn wound infections caused by MRSA.
Topics: Animals; Wound Healing; Methicillin-Resistant Staphylococcus aureus; Burns; Plant Extracts; Male; Ointments; Rats; Rats, Wistar; Anti-Inflammatory Agents; Plant Leaves; Myrtus; Anti-Infective Agents; Wound Infection; Staphylococcal Infections; Metal Nanoparticles; Silver Sulfadiazine
PubMed: 38899039
DOI: 10.1155/2024/6758817 -
Skin Research and Technology : Official... Jun 2024Hypertrophic scars (HS) are a common disfiguring condition in daily clinical encounters which brings a lot of anxieties and concerns to patients, but the treatment...
BACKGROUND
Hypertrophic scars (HS) are a common disfiguring condition in daily clinical encounters which brings a lot of anxieties and concerns to patients, but the treatment options of HS are limited. Black cloth ointment (BCO), as a cosmetic ointment applicable to facial scars, has shown promising therapeutic effects for facial scarring. However, the molecular mechanisms underlying its therapeutic effects remain unclear.
MATERIAL AND METHODS
Network pharmacology was first applied to analyze the major active components of BCO and the related signaling pathways. Subsequently, rabbit ear scar model was successfully established to determine the pharmacological effects of BCO and its active component β-elemene on HS. Finally, the molecular mechanism of BCO and β-elemene was analyzed by Western blot.
RESULTS
Through the network pharmacology, it showed that β-elemene was the main active ingredient of BCO, and it could significantly improve the pathological structure of HS and reduce collagen deposition. BCO and β-elemene could increase the expression of ER stress-related markers and promote the increase of apoptotic proteins in the Western blot experiment and induce the apoptosis of myofibroblasts.
CONCLUSIONS
Our findings indicate that the material basis for the scar-improving effects of the BCO is β-elemene, and cellular apoptosis is the key mechanism through which the BCO and β-elemene exert their effects.
Topics: Cicatrix, Hypertrophic; Rabbits; Animals; Ointments; Network Pharmacology; Disease Models, Animal; Sesquiterpenes; Humans; Apoptosis; Female; Male
PubMed: 38895902
DOI: 10.1111/srt.13791 -
BioRxiv : the Preprint Server For... Jun 2024Protein engineering through the chemical or enzymatic ligation of polypeptide fragments has proven enormously powerful for studying countless biochemical processes . In...
Protein engineering through the chemical or enzymatic ligation of polypeptide fragments has proven enormously powerful for studying countless biochemical processes . In general, this strategy necessitates a protein folding step following ligation of the unstructured fragments, a requirement that constrains the types of systems amenable to the approach. Here, we report an strategy that allows internal regions of target proteins to be replaced in a single operation. Conceptually, our system is analogous to a DNA transposition reaction, but employs orthogonal pairs of split inteins to swap out a designated region of a host protein with an exogenous molecular cassette. We show using isotopic labeling experiments that this 'protein transposition' reaction is concerted when the kinetics for the embedded intein pairs are suitably matched. Critically, this feature allows for efficient manipulation of protein primary structure in the context of a native fold. The utility of this method is illustrated using several protein systems including the multisubunit chromatin remodeling complex, ACF, where we also show protein transposition can occur within the cell nucleus. By carrying out a molecular 'cut and paste' on a protein or protein complex under native folding conditions, our approach dramatically expands the scope of protein semisynthesis.
PubMed: 38895383
DOI: 10.1101/2024.06.03.597171 -
Materials (Basel, Switzerland) Jun 2024This paper presents a method for designing low carbon bio-based building materials, also named bio-concretes, produced with wood wastes in shavings form (WS) and...
This paper presents a method for designing low carbon bio-based building materials, also named bio-concretes, produced with wood wastes in shavings form (WS) and cementitious pastes. As the aggregates phase of bio-concretes is composed of plant-based particles, known as porous and high water-absorbing materials, the bio-concretes cannot be designed by using the traditional design rules used for conventional mortar or concrete. Then, the method used in the current paper is an adaptation of a previous one that has been developed in a recent paper where bio-concretes were produced with a cement matrix, three types of bio-aggregates, and a proposal of a design abacus. However, when that abacus is used for designing WBC with low cement content in the matrix, the target compressive strength is not reached. In the present paper, the method is extended to low cement content matrix (up to 70% of cement substitution) and also considering the greenhouse gas (GHG) emission of the WBC. To obtain data for proposing a new design abacus, an experimental program was carried out by producing nine workable WBCs, varying wood volumetric fractions (40-45-50%), and water-to-binder ratios. The bio-concretes produced presented adequate consistency, lightness (density between 715 and 1207 kg/m), and compressive strength ranging from 0.64 to 12.27 MPa. In addition, the GHG emissions of the WBC were analysed through the Life Cycle Assessment methodology. From the relationships obtained between density, compressive strength, water-to-binder ratio, cement consumption, and GHG emissions of the WBC, calibration constants were proposed for developing the updated and more complete abacus regarding an integrated mix design methodology.
PubMed: 38894006
DOI: 10.3390/ma17112742 -
Materials (Basel, Switzerland) Jun 2024A low-shrinkage and viscosity-reducing polycarboxylate superplasticizer was synthesized with maleic anhydride (MAH), diethylene glycol monobutyl ether, and methoxypoly...
A low-shrinkage and viscosity-reducing polycarboxylate superplasticizer was synthesized with maleic anhydride (MAH), diethylene glycol monobutyl ether, and methoxypoly (ethylene glycol) methacrylate (MPEGMA). The surface tension, early shrinkage, cement paste performance, and application performance of concrete made with the synthesized water-reducing admixture were tested. A series of experiments were conducted to determine the optimal range of plastic viscosity coefficients for producing high-quality, fair-faced concrete with minimal surface defects. These experiments utilized both the synthesized water-reducing admixture alone and in combination with other water-reducing agents. The results showed that the synthesized water-reducing admixture had an ideal molecular structure, as confirmed by the GPC spectrum. When added to an aqueous solution, it reduced the surface tension from 72.47 mN/m to 30.56 mN/m. The 72 h shrinkage value of concrete was reduced by 20.6% compared with that of the conventional control group, effectively reducing shrinkage and adjusting the viscosity of the concrete mixture. Additionally, the influence of the plastic viscosity coefficient on the apparent voids in fair-faced concrete was investigated. This study revealed that when the plastic viscosity coefficient was between 5 and 10 Pa·s, the apparent void grade of the fair-faced concrete was simultaneously excellent and good. This water-reducing admixture helped prevent surface cracking and voids in fair-faced concrete, making it a suitable choice for producing high-quality fair-faced concrete surfaces.
PubMed: 38893950
DOI: 10.3390/ma17112685 -
Materials (Basel, Switzerland) May 2024In this research, the properties and cementitious performance of thermally activated cement pastes (referred to as DCPs) are investigated. Hydrated pastes prepared from...
In this research, the properties and cementitious performance of thermally activated cement pastes (referred to as DCPs) are investigated. Hydrated pastes prepared from Portland cement and slag blended cement were subjected to different thermal treatments: 350 °C for 2 h, 550 °C for 2 h, 550 °C for 24 h and 750 °C for 2 h. The properties and the reactivity as SCM of the DCPs were characterised as well as their effect on the mechanical performance and hydration of new blended cements incorporating the DCPs as supplementary cementitious materials (SCMs). It was observed that the temperature and duration of the thermal treatment increased the grindability and BET specific surface area of the DCP, as well as the formation of CS phases and the reactivity as SCM. In contrast, the mechanical strength results for the blended cements indicated that thermal treatment at 350 °C for 2 h provided better performance. The hydration study results showed that highly reactive DCP interfered with the early hydration of the main clinker phases in Portland cement, leading to early setting and slow strength gain. The effect on blended cement hydration was most marked for binary Portland cement-DCP blends. In contrast, in the case of ternary slag cement-DCP blends the use of reactive DCP as SCM enabled to significantly increase early age strength.
PubMed: 38893922
DOI: 10.3390/ma17112659 -
Materials (Basel, Switzerland) May 2024This study investigated the influences of ultrafine fly ash (UFA) and ultrafine slag powder (USL) on the compressive strengths, autogenous shrinkage, phase assemblage,...
This study investigated the influences of ultrafine fly ash (UFA) and ultrafine slag powder (USL) on the compressive strengths, autogenous shrinkage, phase assemblage, and microstructure of magnesium potassium phosphate cement (MKPC). The findings indicate that the aluminosilicate fractions present in both ultrafine fly ash and ultrafine slag participate in the acid-base reaction of the MKPC system, resulting in a preferential formation of irregularly crystalline struvite-K incorporating Al and Si elements or amorphous aluminosilicate phosphate products. UFA addition mitigates early age autogenous shrinkage in MKPC-based materials, whereas USL exacerbates this shrinkage. In terms of the sustained mechanical strength development of the MKPC system, ultrafine fly ash is preferred over ultrafine slag powder. MKPC pastes with ultrafine fly ash show greater compressive strength compared to those with ultrafine slag powder at 180 days due to denser interfaces between the ultrafine fly ash particles and hydration products like struvite-K. The incorporation of 30 wt% ultrafine fly ash enhances compressive strengths across all testing ages.
PubMed: 38893820
DOI: 10.3390/ma17112556