Hasil untuk "General. Including alchemy"

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DOAJ Open Access 2026
Towards Zero-Waste Valorization of African Catfish By-Products Through Integrated Biotechnological Processing and Life Cycle Assessment

Orsolya Bystricky-Berezvai, Miroslava Kovářová, Daniel Kašík et al.

African catfish (<i>Clarias gariepinus</i>, AC) is one of the most widely farmed freshwater fish species in Central Europe. Processing operations generate up to 55% by-products (BPs), predominantly carcasses rich in proteins, lipids, and minerals. This study develops a comprehensive valorization process for ACBPs to recover gelatin, protein hydrolysate, fish oil, and pigments. The processing protocol consisted of sequential washing, oil extraction, demineralization, and biotechnological treatment to disrupt the collagen quaternary structure. A two-factor experimental design was employed to optimize the processing conditions. The factors included the extraction temperatures of the first (35–45 °C) and second fraction (50–60 °C). We hypothesized that enzymatic conditioning, combined with sequential hot-water extraction, would yield gelatin with properties comparable to those of mammalian- and fish-derived gelatins, while enabling a near-zero-waste process. The integrated process yielded 18.2 ± 1.2% fish oil, 9.8 ± 2.1% protein hydrolysate, 1.7 ± 0.7% pigment extract, and 25.3–37.8% gelatin. Optimal conditions (35 °C/60 °C) produced gelatin with gel strength of 168.8 ± 3.6 Bloom, dynamic viscosity of 2.48 ± 0.02 mPa·s, and yield of 34.76 ± 1.95%. Life cycle assessment (LCA) identified two primary environmental hotspots: water consumption and energy demand. This near-zero-waste biorefinery demonstrates the potential for comprehensive valorization of aquaculture BPs into multiple value-added bioproducts.

Science, Chemistry
DOAJ Open Access 2026
A Comprehensive Review on Innovative Food Gelling Strategies for Sustainable Production of Meat Analogs and Restructured Meat

AMM Nurul Alam, Abdul Samad, Ayesha Muazzam et al.

The growing need for ecologically sound and ethical protein sources has contributed to the development of meat analogs (MAs) and restructured meat products (RMPs). Next generation MA and RMP production requires sustainable structuring techniques to imitate the physical, chemical, and sensory characteristics of conventional meat. Innovative gelling techniques are essential for attaining optimal texture, chewiness, and structural firmness in MAs and RMPs. Food gels can modulate water and fat retention, as well as the physical and mechanical characteristics of MA and RMP. Different gelling systems such as hydrogels, emulsion gels, oleogels, and hybrid gels contribute to texture formation, water and fat retention, juiciness, and structural integrity, which are essential for mimicking conventional meat. The role of gels as key structuring elements is integrated with advanced processing technologies such as high-moisture extrusion and 3D printing. This review discusses how protein, polysaccharide, lipid, and hybrid gelling techniques facilitate the development of MAs and RMPs with enhanced texture, sensory quality, nutritional value, and sustainability. Advanced structuring techniques, such as high-moisture extrusion, shear cell processing, and 3D printing, are explained regarding their integration of tailored gels (hydrogels, emulsion gels, oleogels, and hybrid gels) to fabricate imitated meat structures. Moreover, this article investigates the sensory and nutritional ramifications of various gelling techniques, spanning their role in juiciness and flavor composition. This review emphasizes significant research deficiencies and suggests more extensive future studies to facilitate the further development of economically viable and sustainable MAs and RMPs.

Science, Chemistry
DOAJ Open Access 2025
A Stability Study of [Cu(I)(dmby)<sub>2</sub>]TFSI in Biopolymer-Based Aqueous Quasi-Solid Electrolytes

Giulia Adriana Bracchini, Elvira Maria Bauer, Claudia Mazzuca et al.

In the field of advanced electrical energy conversion and storage, remarkable attention has been given to the development of new, more sustainable electrolytes. In this regard, the combination of redox shuttles with aqueous bio-polymer gels seems to be a valid alternative via which to overcome the typical drawbacks of common liquid electrolytes such as corrosion, volatility or leakage. Despite the promising results obtained so far, redox-active species such as bis(6,6′-dimethyl-2,2′-bipyridine)copper(I) trifluoromethanesulfonylimide, ([Cu(I)(dmby)<sub>2</sub>]TFSI), still present inherent challenges associated with their poor water solubility and oxidative lability, which prevents their employment in cheap and sustainable aqueous electrolytes. The present study investigates the stabilization of the Cu(I) complex ([Cu(I)(dmby)<sub>2</sub>]TFSI) within two natural hydrogels based on the biopolymers κ-carrageenan and galactomannan, using ZnO nanoparticles as gelling agents. These eco-friendly and biocompatible systems are proposed as potential matrices for quasi-solid electrolytes (QSEs), offering a promising platform for advanced electrolyte design in electrochemical applications. Both hydrogels effectively stabilized and retained the redox species within their networks. In order to shed light on distinct stabilization mechanisms, complementary FTIR and SEM analyses were relevant to reveal the structural rearrangements, specific to each matrix, upon complex incorporation. Furthermore, thermogravimetric analysis confirmed notable thermal resilience in both systems, with the galactomannan-based gel demonstrating enhanced performance. Altogether, this work introduces a novel strategy for embedding copper-based redox couples into gelled electrolytes, paving the way toward their integration in real electrochemical devices, where long-term stability, redox retention, and energy conversion efficiency are critical evaluation criteria.

Science, Chemistry
DOAJ Open Access 2025
Research on the Electrical Tree Deterioration Characteristics of Silicone Gel and Silicone Rubber Under Pulsed Electric Field

Cong Zhang, Xiangze An, Qingfa Li et al.

Silicone gel and silicone rubber are widely used in packaging insulation because of their high comprehensive performance. Nevertheless, the special deterioration mechanism under pulsed electric fields is not yet clear and needs to be studied in depth. This study has successfully built an experimental platform of the electrical tree under a thermal coupled pulsed electric field. Moreover, the effects of the pulse edge time, repetition frequency, and temperature on the tree initiation voltage, intuitive development morphology, and fractal dimension of the electrical tree are also investigated, respectively. In conclusion, silicone rubber has a higher insulation strength, while silicone gel has a certain self-recovery performance. The aim of the study is to realize the electrical tree deterioration characteristics of silicone gel and silicone rubber. The increase in repetition frequency, the decrease in edge time, and the increase in temperature all contribute to the initiation and growth of the electrical tree from different degrees and angles, making the electrical tree transform between a fine, dendritic, clumped, and pine-like shape.

Science, Chemistry
DOAJ Open Access 2024
The Influence of Fluoride Gels on the Physicochemical Properties of Tooth Tissues and Dental Materials—A Systematic Review

Paweł J. Piszko, Aleksandra Piszko, Jan Kiryk et al.

The aim of the presented systematic review is to update the state of knowledge and relate the properties and composition of fluoride gels to their potential application. This article aims to explore the effect of fluoride gel application on changes in the properties of dental biomaterials and tooth tissues. The review includes articles assessing studies on the effects of fluoride gel on dental tissues and materials. Employing the PRISMA protocol, a meticulous search was conducted across the PubMed, Scopus, and Web of Science databases, utilizing keywords such as fluoride, gel, and properties. The publications were selected without limitation by the year of publication, and then Cohen’s κ test was used to assess the agreement of the respondents. Exclusion criteria included non-English studies, opinion pieces, editorial papers, letters to the editor, review articles and meta-analyses, clinical reports, studies lacking full-text accessibility, and duplicates. The quality of the chosen papers was assessed by two independent reviewers. A total of 2385 were located in databases, of which only 17 met the inclusion criteria. All publications showed increased surface mineralization, and seven studies showed the effect of fluoride gel on the surface of dental tissues. Three articles stated a negative effect of fluoride gels on titanium and stainless steel alloys and glass ionomer fillings. The effects on shear bond strength and plaque deposition require further investigation because the study results are contradictory.

Science, Chemistry
DOAJ Open Access 2024
Streamlining Skin Regeneration: A Ready-To-Use Silk Bilayer Wound Dressing

Anabela Veiga, Inês V. Silva, Juliana R. Dias et al.

Silk proteins have been highlighted in the past decade for tissue engineering (TE) and skin regeneration due to their biocompatibility, biodegradability, and exceptional mechanical properties. While silk fibroin (SF) has high structural and mechanical stability with high potential as an external protective layer, traditionally discarded sericin (SS) has shown great potential as a natural-based hydrogel, promoting cell–cell interactions, making it an ideal material for direct wound contact. In this context, the present study proposes a new wound dressing approach by developing an SS/SF bilayer construct for full-thickness exudative wounds. The processing methodology implemented included an innovation element and the cryopreservation of the SS intrinsic secondary structure, followed by rehydration to produce a hydrogel layer, which was integrated with a salt-leached SF scaffold to produce a bilayer structure. In addition, a sterilization protocol was developed using supercritical technology (sCO<sub>2</sub>) to allow an industrial scale-up. The resulting bilayer material presented high porosity (>85%) and interconnectivity while promoting cell adhesion, proliferation, and infiltration of human dermal fibroblasts (HDFs). SS and SF exhibit distinct secondary structures, pore sizes, and swelling properties, opening new possibilities for dual-phased systems that accommodate the different needs of a wound during the healing process. The innovative SS hydrogel layer highlights the transformative potential of the proposed bilayer system for biomedical therapeutics and TE, offering insights into novel wound dressing fabrication.

Science, Chemistry
DOAJ Open Access 2024
Preparation of Ovalbumin/Xanthan Gum/Chitosan Pickering Emulsion Oleogel Added with <i>Amomum villosum</i> Lour. Extract and Its Application in Cookies

Shan Xue, Jilong Zhao, Zhouyi Xiong et al.

In this study, a new oleogel system was constructed and used as a fat substitute in the processing of cookies. The preparation process of <i>Amomum villosum</i> Lour. extract (AVE) was optimized based on antioxidant activity and yield firstly. Then, the AVE, ovalbumin, chitosan, and xanthan gum were used as raw materials to prepare a composite Pickering emulsion oleogel. The results showed that when the concentration of AVE, chitosan, and XG were 0.1%, 2.5%, and 0.3%, respectively, a stable and uniformly distributed Pickering emulsion oleogel was formed. In this case, the particle size of the composite oleogel was relatively small; the absolute value of zeta potential was higher; the microstructure was more stable, with less aggregation and flocculation; and the thermal stability and freeze–thaw stability were excellent. In addition, the addition of AVE enhanced the gel properties of the oleogel and had good solid-like properties, and strengthened the binding force, as well as the oxidation stability, making the whole system more stable. In addition, the results of the application of the composite oleogel in the cookies showed that the AVE–ovalbumin/xanthan gum/chitosan Pickering emulsion oleogel had similar sensory and texture properties to the butter group. The addition of AVE can delay the crispness, cohesiveness, hardness, and the rate of malondialdehyde formation in cookies during storage. In conclusion, the AVE–ovalbumin/xanthan gum/chitosan Pickering emulsion oleogel had good physicochemical stability and showed great potential in replacing saturated fat (butter) in baking products (cookies).

Science, Chemistry
DOAJ Open Access 2024
Preparation and Characterization of Responsive Cellulose-Based Gel Microspheres for Enhanced Oil Recovery

Peng Yin, Fang Shi, Mingjian Luo et al.

As an important means to enhance oil recovery, ternary composite flooding (ASP flooding for short) technology has achieved remarkable results in Daqing Oilfield. Alkalis, surfactants and polymers are mixed in specific proportions and injected into the reservoir to give full play to the synergistic effect of each component, which can effectively enhance the fluidity of crude oil and greatly improve the oil recovery. At present, the technology for further improving oil recovery after ternary composite flooding is not mature and belongs to the stage of technical exploration. The presence of alkaline substances significantly alters the reservoir’s physical properties and causes considerable corrosion to the equipment used in its development. This is detrimental to both the environment and production. Therefore, it is necessary to develop green displacement control agents. In the reservoir environment post-ASP flooding, 2-(methylamino)ethyl methacrylate and glycidyl methacrylate were chosen as monomers to synthesize a polymer responsive to alkali, and then grafted with cellulose nanocrystals to form microspheres of alkali-resistant swelling hydrogel. Cellulose nanocrystals (CNCs) modified with functional groups and other materials were utilized to fabricate hydrogel microspheres. The product’s structure was characterized and validated using Fourier transform infrared spectroscopy and X-ray diffraction. The infrared spectrum revealed characteristic absorption peaks of CNCs at 1165 cm<sup>−1</sup>, 1577 cm<sup>−1</sup>, 1746 cm<sup>−1</sup>, and 3342 cm<sup>−1</sup>. The diffraction spectrum corroborated the findings of the infrared analysis, indicating that the functional modification occurred on the CNC surface. After evaluating the swelling and erosion resistance of the hydrogel microspheres under various alkaline conditions, the optimal particle size for compatibility with the target reservoir was determined to be 6 μm. The potential of cellulose-based gel microspheres to enhance oil recovery was assessed through the evaluation of Zeta potential and laboratory physical simulations of oil displacement. The study revealed that the absolute value of the Zeta potential for gel microspheres exceeds 30 in an alkaline environment with pH values ranging from 7 to 14, exhibiting a phenomenon where stronger alkalinity correlates with a greater absolute value of Zeta potential. The dispersion stability spans from good to excellent. The laboratory oil displacement simulation experiment was conducted using a cellulose-based gel microsphere system following weak alkali ASP flooding within the pH value range from 7 to 10. The experimental interventions yielded recovery rates of 2.98%, 3.20%, 3.31%, and 3.38%, respectively. The study indicates that cellulose-based gel microspheres exhibit good adaptability in alkaline reservoirs. This research offers a theoretical foundation and experimental approaches to enhance oil recovery techniques post-ASP flooding.

Science, Chemistry
DOAJ Open Access 2024
Antidiabetic Activities and GC-MS Analysis of 4-Methoxychalcone

Leonard D. R. Acho, Edinilze S. C. Oliveira, Simone B. Carneiro et al.

Diabetes mellitus is a chronic metabolic disease that is mainly characterized by hyperglycemia. Chalcones and their derivatives have demonstrated promising pharmacological potential for the treatment of diabetes. The aim of the study was to evaluate antidiabetic activities and analyze 4-methoxychalcone (MPP) using GC-MS. The compound was characterized using mass spectroscopy, nuclear magnetic resonance and headspace with gas chromatography coupled to mass spectrometry (HS-GC-MS). MPP was evaluated via the inhibition of the alpha-glucosidase enzyme, cell viability and antiglycation and hemolytic activities in vitro. The study of the interaction between the bovine serum albumin protein and MPP was investigated via molecular docking. Oral sucrose tolerance and oral glucose tolerance tests were performed in streptozotocin (STZ)-induced diabetic mice. The HS-GC-MS method was able to accurately detect and characterize the compound, and the interaction between MPP and BSA revealed the remarkable affinity for the two main binding sites of BSA. This was confirmed by the in vitro antiglycation test, since MPP showed activity through both oxidative and non-oxidative stress. MPP significantly attenuated the increase in glycemia after glucose loading in STZ-induced diabetic mice. These results confirm that MPP has antihyperglycemic activity and may be an alternative for the treatment of diabetes mellitus.

Analytical chemistry, General. Including alchemy
DOAJ Open Access 2023
Synthesis and Characterization of an Novel Intercalated Polyacrylamide/Clay Nanocomposite

Song Zhang, Falin Wei, Pingde Liu et al.

Solving the problem of the low temperature and low salt resistances of conventional polyacrylamide and the high cost of functional monomers, and thus, introducing it to the interlayer space provided by a layered structure for polymer modification, is a promising option. In this study, montmorillonite was used as the inorganic clay mineral, and an intercalated polyacrylamide/clay nanocomposite was synthesized via in situ intercalation polymerization. The optimal synthesis conditions were a clay content of 10.7%, preparation temperature of 11 °C, initiator concentration of 2.5 × 10<sup>−4</sup> mol/L, and chain extender concentration of 5%. The IR results showed that the polymer was successfully introduced to the nanocomposite. The synthesized intercalated polyacrylamide/clay nanocomposite exhibited a better thickening effect, good viscoelasticity, and better salt resistance and thermal stability than polyacrylamide. In addition, the thickening capacity and thermal stability were superior to the salt-resistant polymer, with a 16.0% higher thickening viscosity and a 15.1% higher viscosity retention rate at 85 °C for 60 d. The intercalated polyacrylamide/clay nanocomposite further expanded the application of polyacrylamide in petroleum exploitation.

Science, Chemistry
DOAJ Open Access 2023
Organogel of Acai Oil in Cosmetics: Microstructure, Stability, Rheology and Mechanical Properties

Suellen Christtine da Costa Sanches, Maria Inês Ré, José Otávio Carréra Silva-Júnior et al.

Organogel (OG) is a semi-solid material composed of gelling molecules organized in the presence of an appropriate organic solvent, through physical or chemical interactions, in a continuous net. This investigation aimed at preparing and characterizing an organogel from acai oil with hyaluronic acid (HA) structured by 12-hydroxystearic acid (12-HSA), aiming at topical anti-aging application. Organogels containing or not containing HA were analyzed by Fourier-transform Infrared Spectroscopy, polarized light optical microscopy, thermal analysis, texture analysis, rheology, HA quantification and oxidative stability. The organogel containing hyaluronic acid (OG + HA) has a spherulitic texture morphology with a net-like structure and absorption bands that evidenced the presence of HA in the three-dimensional net of organogel. The thermal analysis confirmed the gelation and the insertion of HA, as well as a good thermal stability, which is also confirmed by the study of oxidative stability carried out under different temperature conditions for 90 days. The texture and rheology studies indicated a viscoelastic behavior. HA quantification shows the efficiency of the HA cross-linking process in the three-dimensional net of organogel with 11.22 µg/mL for cross-linked HA. Thus, it is concluded that OG + HA shows potentially promising physicochemical characteristics for the development of a cosmetic system.

Science, Chemistry
S2 Open Access 2022
Button battery injury: An update.

H. Burns, Soo-Ji Park

BACKGROUND Paediatric button battery injuries present a challenge in the general practice setting. Although some children present with history or parental suspicion of button battery ingestion (BBI) or insertion, unwitnessed cases may present with non-specific symptoms that can mimic many respiratory and gastrointestinal pathologies. OBJECTIVE The aim of this article is to increase awareness of the fast onset of life-threatening tissue injury from BBI and the importance of timely referral as well as provide an update on current management, including first aid management in the general practice setting. DISCUSSION BBI is a medical emergency. The button battery requires urgent removal as it can cause caustic burn injury to its surrounding tissues in as little as 15 minutes. Limited awareness of the time-critical nature of this presentation has been reported in multiple triage settings. Studies have shown a role for consumption of honey or sucralfate in delaying tissue injury while awaiting surgical removal.

14 sitasi en Medicine
S2 Open Access 2022
Anaesthesia and the development of functional neurological disorder: A systematic review and case series.

Daniela Huepe-Artigas, Parramajaypal Singh, Laurence Weinberg et al.

OBJECTIVE There are reports of functional neurological disorder (FND) developing after anaesthesia, though separating any aetiological role from other possible factors is challenging. We aimed to systematically review all published cases of post-anaesthetic FND to see if any common factors supported an anaesthetic role. We also aimed to identify all cases of post-anaesthetic FND arising in our FND clinic, to obtain an estimate of its frequency. METHODS For the review, a systematic search for published cases of FND developing within 48 h of anaesthesia was conducted in June 2022. For the case series, the medical records of all patients attending an FND clinic in Melbourne between 2017 and 2019 were examined, and all cases with FND within 48 h of anaesthesia extracted. RESULTS 36 published cases were identified for the review. Sixteen described preceding stressors and 16 psychiatric diagnoses, including 8 with previous FND. Thirty-two (92%) had undergone general anaesthesia, most commonly for obstetric procedures. Motor/sensory loss was the most common presentation, followed by seizures and coma. Most (80.5%) developed symptoms immediately on induction or cessation of anaesthesia. For the case series, 8 of 107 clinic patients (7.5%), developed FND within 48 h of anaesthesia. All had previous psychiatric diagnoses, including 3 with previous FND. Three underwent general anaesthesia and 3 procedural sedation, with seizures the most common presentation. All developed symptoms immediately on induction or cessation of anaesthesia. CONCLUSION These cases provide some support for an aetiological role for anaesthesia: there is evidence for an anaesthetic 'model' for the symptoms of FND that arise, they largely arise with the onset or termination of anaesthesia, and they arise most frequently during general anaesthesia or sedation.

11 sitasi en Medicine
DOAJ Open Access 2022
Molecular and Aggregate Structural, Thermal, Mechanical and Photophysical Properties of Long-Chain Amide Gelators Containing an α-Diketo Group in the Presence or Absence of a Tertiary Amine Group

Girishma Grover, Andrea Blake Brothers, Richard G. Weiss

Three structurally related gelators, each containing octadecyl chains, an α-diketo group at the 9,10 positions, and each with a different N-amide group—isobutyl (DIBA), isopentyl (DIPA) or N-(2-(dimethylamino)ethyl) (DMEA)—have been synthesized. Their neat structures as well as the thermal mechanical, and photophysical properties in their gel states with various liquids have been investigated. The gelator networks of DIBA and DIPA in octane, hexylbenzene and silicone oil consist of bundles of fibers. These gels are partially thixotropic and mechanically, thermally (to above their melting or silicone oil gelation temperatures), and photophysically stable. They are mechanically and thermally stronger than the gels formed with DMEA, the gelator with a tertiary amine group. The lone pair of electrons of the tertiary amine group leads to an intra-molecular or inter-molecular charge-transfer interaction, depending on whether the sample is a solution, sol, or gel. Neat, solid DMEA does not undergo the charge-transfer process because its amino and diketo groups are separated spatially by a large distance in the crystalline state and cannot diffuse into proximity. However, the solution of DIPA upon the addition of triethylamine becomes unstable over time at room temperature in the dark or (more rapidly) when irradiated, which initiates the aforementioned charge-transfer processes. The eventual reaction of the gelators in the presence of a tertiary amine group is ascribed to electron transfer from the lone-pair on nitrogen to an α-diketo group, followed by proton transfer to an oxygen atom on the anion radical of the α-diketo group from a methyl or methylene group attached to the nitrogen atom of the cation radical. Finally, the formation of an α-diketyl radical leads to irreversible electronic and structural changes that are observed over time.

Science, Chemistry
DOAJ Open Access 2022
Application of Polyacrylic Hydrogel in Durability and Reduction of Environmental Impacts of Concrete through ANN

Kang Peng, Longliang Wu, Yousef Zandi et al.

While adding superabsorbent polymer hydrogel particles to fresh concrete admixtures, they act as internal curing agents that absorb and then release large amounts of water and reduce self-desiccation and volumetric shrinkage of cement that finally result in hardened concrete with increased durability and strength. The entrainment of microscopic air bubbles in the concrete paste can substantially improve the resistance of concrete. When the volume and distribution of entrained air are adequately managed, the microstructure is protected from the pressure produced by freezing water. This study addresses the design and application of hydrogel nanoparticles as internal curing agents in concrete, as well as new findings on crucial hydrogel–ion interactions. When mixed into concrete, hydrogel particles produce their stored water to power the curing reaction, resulting in less volumetric shrinkage and cracking and thereby prolonging the service life of concrete. The mechanical and swelling performance qualities of the hydrogel are very sensitive to multivalent cations found naturally in concrete mixes, such as aluminum and calcium. The interactions between hydrogel nanoparticles and alkaline cementitious mixes are described in this study, while emphasizing how the chemical structure and shape of the hydrogel particles regulate swelling behavior and internal curing efficiency to eliminate voids in the admixture. Moreover, in this study, an artificial neural network (ANN) was utilized to precisely and quickly analyze the test results of the compressive strength and durability of concrete. The addition of multivalent cations reduced swelling capacity and changed swelling kinetics, resulting in fast deswelling behavior and the creation of a mechanically stiff shell in certain hydrogel compositions. Notably, when hydrogel particles were added to a mixture, they reduced shrinkage while encouraged the creation of particular inorganic phases within the void area formerly held by the swelled particle.

Science, Chemistry
DOAJ Open Access 2022
An Insight into Pasting and Rheological Behavior of Potato Starch Pastes and Gels with Whole and Ground Chia Seeds

Greta Adamczyk, Magdalena Krystyjan, Piotr Kuźniar et al.

With regard to technological innovations, we applied chia (oilseeds) as a stabilizer additive in a normal and waxy potato starch sample to obtain stable starch-based gels during 20 days of storage. The aim of this study was to investigate the 5% <i>w</i>/<i>w</i> normal and waxy potato starch pastes (hot samples) and gels (cold samples) with the addition of 1% <i>w</i>/<i>w</i> whole and ground chia seeds properties as pasting and flow properties of pastes and textural properties of gels. The pasting process using a viscograph showed that normal and waxy potato starch with the addition of chia had a different pasting characteristic. The addition of chia seeds had a greater effect on the properties of normal potato starch than waxy potato starch. From a rheological point of view, starch pastes without chia were less theologically stable as they showed bigger areas of hysteresis loops. Minor changes in the hardness of gels were obtained in normal starch gels with chia seeds during 20 days of storing compared to the samples without chia seeds, whereas in the waxy starch gels, the effect was the opposite.

Science, Chemistry
DOAJ Open Access 2022
Deformation of Gels with Spherical Auxetic Inclusions

Jan Zidek, Petr Polacek, Josef Jancar

Auxetic metamaterials possess unnatural properties, such as a negative Poisson’s ratio, which offers interesting features when combined with traditional materials. This paper describes the deformation behavior of a gel consisting of spherical auxetic inclusions when embedded in a conventional matrix. The auxetic inclusions and conventional matrix were modeled as spherical objects with a controlled pore shape. The auxetic particle had a reentrant honeycomb, and the conventional phase contained honeycomb-shaped pores. The deformation behavior was simulated using various existing models based on continuum mechanics. For the continuum mechanics models—the simplest of which are the Mori–Tanaka theory and self-consistent field mechanics models—the auxetic particle was homogenized as a solid element with Young’s modulus and Poisson’s ratio and compared with the common composite gel filled with rigid spheres. The finite element analysis simulations using these models were performed for two cases: (1) a detailed model of one particle and its surroundings in which the structure included the design of both the reentrant and conventional honeycombs; and (2) a multiparticle face-centered cubic lattice where both the classic matrix and auxetic particle were homogenized. Our results suggest that auxetic inclusion-filled gels provide an unsurpassed balance of low density and enhanced stiffness.

Science, Chemistry
DOAJ Open Access 2022
From Chondrocytes to Chondrons, Maintenance of Phenotype and Matrix Production in a Composite 3D Hydrogel Scaffold

Mahmoud Amr, Alia Mallah, Samina Yasmeen et al.

Osteoarthritis (OA) is a degenerative disease characterized by articular cartilage (AC) degradation that affects more than 30 million people in the USA. OA is managed with symptom-alleviating medications. Matrix-assisted autologous chondrocyte transplantation (MACT) is a tissue-engineered option, but current products are expensive and lack mechanical tunability or processability to match defect mechanical properties and anatomical shapes. Here, we explore the efficacy of a biocompatible hydrogel-based scaffold composed of sodium alginate, gelatin, and gum Arabic—referred to by SA–GEL–GA—to support bovine articular chondrocyte (bAChs) proliferation, pericellular matrix (PCM), and extracellular matrix (ECM) production. bAChs were grown for 45 days in SA–GEL–GA. Their viability, their live/dead status, histological staining, biochemical assays for glycosaminoglycans (GAGs) and collagen, atomic force microscopy (AFM) imaging, and immunofluorescence staining of collagen I, collagen II, aggrecan, and CD44 were assessed. We found that SA–GEL–GA was not cytotoxic, induced cellular proliferation by 6.1-fold while maintaining a round morphology, and supported ECM deposition by producing 3.9-fold more GAG compared to day 0. bAChs transformed into chondrons and produced a PCM enriched with collagen II (3.4-fold), aggrecan (1.7-fold), and CD44 (1.3-fold) compared to day 0. In summary, SA–GEL–GA supported the proliferation, ECM production, and PCM production of bAChs in vitro.

Science, Chemistry
S2 Open Access 2021
Medications and doctor-patient communication.

Lisa Parker, Rebecca Ryan, Suellen Young et al.

BACKGROUND Doctor-patient communication is an important part of safe and effective medication use. There is a lot of evidence about good communication and recognition of several key features that are important when discussing medications. OBJECTIVE The aim of this article is to provide evidence-based guidance for general practitioner (GP) communication with patients about starting, reviewing or stopping oral medication. DISCUSSION Communication involves listening and asking, as well as imparting information. Creating space for discussions and encouraging patient involvement by asking questions are important. Doctors should deliver core content about why to take medication and actionable messages about how to do so. Regular summing-up and checks of patient understanding are important. Communicating benefits and harms can be facilitated by including numbers, if done carefully (include time periods, natural frequencies, absolute figures). Scheduling extra time, using written resources and enlisting support of pharmacist colleagues can assist with effective communication and help patients navigate the sometimes-confusing world of medications.

24 sitasi en Medicine

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