Hasil untuk "General. Including alchemy"

Vlad Constantin, Ionut Luchian, Dragos Ioan Virvescu et al.

Hyaluronic acid (HA), a naturally occurring glycosaminoglycan and major component of the extracellular matrix, has attracted increasing interest as a therapeutic adjunct in oral wound management due to its biological activity and biocompatibility. The search for the current narrative review literature was performed in the PubMed/MEDLINE, Scopus, and Web of Science databases for studies published up to December 2025. Eligible studies included experimental investigations, clinical trials, and relevant reviews assessing HA applications in oral mucosal or gingival wounds. Available clinical evidence suggests potential benefits of HA in reducing postoperative discomfort, accelerating re-epithelialization, and improving soft tissue healing following periodontal and surgical procedures. However, substantial heterogeneity exists regarding molecular weight, formulation, concentration, and application protocols, which limits direct comparison between studies and precludes definitive conclusions. Further well-designed, standardized clinical trials are required to clarify optimal formulations and confirm long-term therapeutic benefits.

Yan Xin, Binfei Li, Jingyu Zhang et al.

Gel foam exhibits excellent applicability in fractured-vuggy reservoirs, effectively plugging flow channels and enhancing oil recovery. However, due to the harsh high-temperature environment and the complex and variable fracture-vuggy structure in reservoirs, gel foam may undergo structural changes during its migration, which can affect its flow properties and plugging efficiency. Therefore, investigating the migration characteristics of gel foam in fractured reservoirs through visual experiments is of significant practical importance. In this study, migration experiments with different foam systems were conducted using the visualized vuggy model. The migration stability of foam was characterized by combining the sweep range and liquid drainage rate, and the impact of temperature on the migration characteristics of gel foam was explored. Additionally, a profile control experiment was performed using the fractured-vuggy network model, analyzing and summarizing its mechanisms for enhancing oil recovery in fractured-vuggy reservoirs. The results showed that, in the vuggy model, compared with ordinary foam and polymer foam, gel foam showed a lower drainage rate, higher foam retention rate and wider sweep range, and could form stable plugging in fractured-vuggy reservoirs. An increased temperature accelerated the thermal expansion of gas and changes in liquid film characteristics, which led to the expansion of foam migration speed and sweep range. Although a high temperature increased the liquid drainage rate of foam, it was still lower than 3%, and the corresponding foam retention rate was higher than 97%. In addition, the gel foam had a strong profile control ability, which effectively regulated the gas migration path and improved the utilization degree of remaining oil. Compared with the first gas flooding, the recovery of subsequent gas flooding was increased by 18.85%, and the final recovery of the model reached 81.51%. Comprehensive analysis revealed that the mechanism of enhanced oil recovery by gel foam mainly included density control, foam regeneration, flow redirection, stable plugging, and deep displacement by stable gel foam. These mechanisms worked synergistically to contribute to increased recovery. The research results fully demonstrate the application advantages of gel foam in fractured-vuggy reservoirs.

Christina Gioti, Dimitrios K. Papayannis, Vasilios S. Melissas

Two different zeolite model clusters were considered in this study to shed light on the release mechanism of a drug, ASA (acetylsalicylic acid), adsorbed on the Y-type zeolite pore walls. Initially, the 3T cluster was employed as a preliminary approach to reveal the trends developed in the acetylsalicylic acid-zeolite system due to the presence of water molecules. Then, the cluster was expanded to 38T (12T:26T), and the adsorption of acetylsalicylic acid in the presence of water molecules inside the pores of the zeolite was studied by employing the hybrid (QM/MM) approximation at the ONIOM2//(HSEH1PBE/6-31+G(d,p):UFF) level of theory. The quantum chemical modeling explicitly shows the water molecules’ impact on the value of the adsorption energy. Specifically, the adsorption energy of acetylsalicylic acid gradually decreases from 32.55 kcal mol⁻¹ (in the case of the 38T model cluster with no H₂O molecules) to 22.10 kcal mol⁻¹ in the presence of three water molecules.

Yubo Lan, Dongyan Qi, Jiawei Li et al.

Micro-nano bubbles (MNBs), typically characterized by diameters ranging from tens of micrometers to hundreds of nanometers, have gained significant attention in recent years due to advancements in nanotechnology and related characterization methods. This technology has shown great promise in the field of petroleum engineering. Among the various applications, the integration of MNBs with gel technology plays a critical role in enhancing drilling safety. This paper aims to systematically review the current status, challenges, and optimization strategies for the application of MNBs in petroleum engineering, with a particular focus on their combined use with gel technology in oilfield applications. The paper first introduces the preparation methods and physicochemical properties of MNBs tailored for oilfield applications. It then systematically reviews the use of MNBs in the following three key areas of petroleum engineering: drilling, enhanced oil recovery (EOR), and oil–water separation. The paper also compares domestic and international technological approaches, highlighting the challenges associated with the large-scale application of MNBs in China. Notably, in the areas of drilling and enhanced oil recovery, the synergistic use of MNBs and gel technology has demonstrated significant potential. The gel–MNB combined technology demonstrates particular promise for China’s special reservoirs, as gel’s high molecular weight compensates for MNBs’ sedimentation defects, while their synergistic effects on interfacial tension reduction and drilling fluid stabilization provide an eco-efficient approach for extreme conditions. Additionally, focusing on the combined application of gel and MNB technology, along with adjustments in gel stability and MNB size, could offer a promising solution for the efficient and sustainable development of special reservoirs (such as those with high temperature, pressure, and salinity) in China.

Abbas Fazel Anvari-Yazdi, Ildiko Badea, Xiongbiao Chen

Postoperative adhesions (POAs) are a common and often serious complication following abdominal and gynecologic surgeries, leading to infertility, chronic pain, and bowel obstruction. To address these outcomes, the development of anti-adhesion barriers using biocompatible materials has emerged as a key area of biomedical research. This article presents a comprehensive overview of clinically relevant natural and synthetic biomaterials explored for POA prevention, emphasizing their degradation behavior, barrier integrity, and translational progress. Natural biopolymers—such as collagen, gelatin, fibrin, silk fibroin, and decellularized extracellular matrices—are discussed alongside polysaccharides, including alginate, chitosan, and carboxymethyl cellulose, focusing on their structural features and biological functionality. Synthetic polymers, including polycaprolactone (PCL), polyethylene glycol (PEG), and poly(lactic-co-glycolic acid) (PLGA), are also examined for their tunable degradation profiles (spanning days to months), mechanical robustness, and capacity for drug incorporation. Recent innovations, such as bioprinted and electrospun dual-layer membranes, are highlighted for their enhanced anti-fibrotic performance in preclinical studies. By consolidating current material strategies and fabrication techniques, this work aims to support informed material selection while also identifying key knowledge gaps—particularly the limited comparative data on degradation kinetics, inconsistent definitions of ideal mechanical properties, and the need for more research into cell-responsive barrier systems.

Adonis Hilal, Anna Florowska, Ewa Domian et al.

Food hydrogels, used as delivery systems for bioactive compounds, can be formulated with various food-grade biopolymers. Their industrial utility is largely determined by their physicochemical properties. However, comprehensive data on the properties of pea protein–psyllium binary hydrogels under different pH and ionic strength conditions are limited. The aim of this research was to evaluate the impact of pH (adjusted to 7, 4.5, and 3) and ionic strength (modified by NaCl addition to 0.15 and 0.3 M) on the physical stability, color, texture, microrheological, and viscoelastic properties of these hydrogels. Color differences were most noticeable at lower pH levels. Inducing hydrogels at pH 7 (with or without NaCl) and pH 4.5 and 3 (without NaCl) resulted in complete gel structures with low stability, low elastic and storage moduli, and low complex viscosity, making them easily spreadable. Lower pH inductions (4.5 and 3) in the absence of NaCl resulted in hydrogels with shorter linear viscoelastic regions. Hydrogels induced at pH 4.5 and 3 with NaCl had high structural stability, high G’ and G” moduli, complex viscosity, and high spreadability. Among the tested induction conditions, pH 3 with 0.3 M NaCl allowed for obtaining a hydrogel with the highest elastic and storage moduli values. Adjusting pH and ionic strength during hydrogel induction allows for modifying and tailoring their properties for specific industrial applications.

Camelia Ungureanu, Silviu Răileanu, Roxana Zgârian et al.

Gel-based membranes, a fusion of polymer networks and liquid components, have emerged as versatile tools in a variety of technological domains thanks to their unique structural and functional attributes. Historically rooted in basic filtration tasks, recent advancements in synthetic strategies have increased the mechanical strength, selectivity, and longevity of these membranes. This review summarizes their evolution, emphasizing breakthroughs that have positioned them at the forefront of cutting-edge applications. They have the potential for desalination and pollutant removal in water treatment processes, delivering efficiency that often surpasses conventional counterparts. The biomedical field has embraced them for drug delivery and tissue engineering, capitalizing on their biocompatibility and tunable properties. Additionally, their pivotal role in energy storage as gel electrolytes in batteries and fuel cells underscores their adaptability. However, despite monumental progress in gel-based membrane research, challenges persist, particularly in scalability and long-term stability. This synthesis provides an overview of the state-of-the-art applications of gel-based membranes and discusses potential strategies to overcome current limitations, laying the foundation for future innovations in this dynamic field.

Geethanjali Kuppadakkath, Ira Volkova, Krishna K. Damodaran

The physical characteristics of a supramolecular gel are greatly influenced by the nature and arrangement of functional groups in the gelator. This work focuses on the impact of the functional groups, specifically the hydroxyl group, on the stimuli-responsive properties of a gel. We used a <i>C</i>₃-symmetric benzene-1,3,5-tricarboxamide (BTA) platform, which was attached to the methyl ester of phenylalanine (MPBTA) and tyrosine (MTBTA). The gelation studies revealed that MPBTA gelled in alcohols, non-polar aromatic solvents, and aqueous mixtures (1:1, <i>v</i>/<i>v</i>) of high-polar solvents, whereas MTBTA gelled only in an aqueous mixture of DMF (1:1, <i>v</i>/<i>v</i>). The mechanical and thermal strength of the gels were evaluated by rheological and <i>T_gel</i> studies, and the results indicated that MPBTA gels were stronger than MTBTA gels. The gels were characterized by powder X-ray diffraction and scanning electron microscopy (SEM). The analysis of stimuli-responsive properties revealed that MPBTA gels were intact in the presence of sodium/potassium salts, but the MTBTA gel network was disrupted. These results indicate that the elegant choice of functional groups could be used to tune the constructive or destructive stimuli-responsive behavior of gels. This study highlights the significant role of functional groups in modulating the stimuli-responsive properties of supramolecular gels.

Hong He, Yuhang Tian, Lianfeng Zhang et al.

Heterogeneous phase combined flooding (HPCF) has been a promising technology used for enhancing oil recovery in heterogeneous mature reservoirs. However, the injectivity and propagation behavior of preformed particle gel (PPG) in low–medium-permeability reservoir porous media is crucial for HPCF treatment in a low–medium-permeability reservoir. Thus, the injectivity and propagation behavior of preformed particle gel in a low–medium-permeability reservoir were systematically studied by conducting a series of sand pack flooding experiments. The matching factor (δ) was defined as the ratio of the average size of PPG particles to the mean size of pore throats and the pressure difference ratio (β) was proposed to characterize the injectivity and propagation ability of PPG. The results show that with the increase in particle size and the decrease in permeability, the resistance factor and residual resistance factor increase. With the increase in the matching factor, the resistance factor and residual resistance factor increase. The higher the resistance factor and residual resistance factor are, the worse the injectivity of particles is. By fitting the relationship curve, PPG injection and propagation standards were established: when the matching coefficient is less than 55 and β is less than 3.4, PPG can be injected; when the matching coefficient is 55–72 and β is 3.4–6.5, PPG injection is difficult; when the matching coefficient is greater than 72 and β is greater than 6.5, PPG cannot be injected Thus, the matching relationship between PPG particle size and reservoir permeability was obtained. This research will provide theoretical support for further EOR research and field application of heterogeneous phase combined flooding.

Peili Luo, Lei Shu, Zhengwei Huang et al.

Management of chronic wounds is becoming a serious health problem worldwide. To treat chronic wounds, a suitable healing environment and sustained delivery of growth factors must be guaranteed. Different therapies have been applied for the treatment of chronic wounds such as debridement and photodynamic therapy. Among them, growth factors are widely used therapeutic drugs. However, at present, growth factor delivery systems cannot meet the demand of clinical practice; therefore new methods should be developed to meet the emerging need. For this reason, researchers have tried to modify hydrogels through some methods such as chemical synthesis and molecule modifications to enhance their properties. However, there are still a large number of limitations in practical use like byproduct problems, difficulty to industrialize, and instability of growth factor. Moreover, applications of new materials like lyotropic liquid crystalline (LLC) on chronic wounds have emerged as a new trend. The structure of LLC is endowed with many excellent properties including low cost, ordered structure, and excellent loading efficiency. LLC can provide a moist local environment for the wound, and its lattice structure can embed the growth factors in the water channel. Growth factor is released from the high-concentration carrier to the low-concentration release medium, which can be precisely regulated. Therefore, it can provide sustained and stable delivery of growth factors as well as a suitable healing environment for wounds, which is a promising candidate for chronic wound healing and has a broad prospective application. In conclusion, more reliable and applicable drug delivery systems should be designed and tested to improve the therapy and management of chronic wounds.

Elena O. Bakhrushina, Elizaveta V. Novozhilova, Marina M. Shumkova et al.

Thermosensitive systems based on poloxamer 407 are widely used in targeted drug delivery; however, the stability of the phase transition temperature remains insufficiently studied. This article presents the results of a study on the effect of adding polyethylene glycols (PEG) with different molecular weights and some classical gel-forming polymers on the gelation temperature of thermoreversible compositions based on poloxamer 407 in a long-term experiment. The study showed a positive effect of PEG addition with average molecular weights at concentrations of 1.5–2.0%, as well as gelling agents at a concentration below the critical gelation concentration. The proposed rheological test for studying the samples’ adhesion can give an indirect forecast of the composition adhesive rate. Based on the conducted studies, three experimental binary systems based on poloxamer 407 were selected, with the addition of HPMC 0.5%, sodium alginate 0.5%, and PEG 1500 1.5%. These systems are the most promising for the further development of in situ targeted drug delivery systems.

Pedro Liz-Basteiro, Felipe Reviriego, Enrique Martínez-Campos et al.

Vat photopolymerization typically prints highly crosslinked networks. Printing hydrogels, which are also networks but with a high swelling capacity in water and therefore with low crosslinking density, is a challenge for this technique. However, it may be of interest in medicine and in other areas, since it would allow for the preparation of this type of 3D-shaped material. In this work, an approach for printing hydrogels via vat photopolymerization that uses a mixture of stable and hydrolysable crosslinkers has been evaluated so that an initial highly crosslinked network can be printed, although after hydrolysis it becomes a network with low crosslinking. This approach has been studied with PEO/PEG-related formulations, that is, with a PEG-dimethacrylate as a stable crosslinker, a PEO-related derivative carrying <i>β</i>-aminoesters as a degradable crosslinker, and PEG-methyl ether acrylate and hydroxyethyl acrylate as monofunctional monomers. A wide family of formulations has been studied, maintaining the weight percentage of the crosslinkers at 15%. Resins have been studied in terms of viscosity, and the printing process has been evaluated through the generation of Jacobs working curves. It has been shown that this approach allows for the printing of pieces of different shapes and sizes via vat photopolymerization, and that these pieces can re-ajust their water content in a tailored fashion through treatments in different media (PBS or pH 10 buffer).

Wafa Mustafa Saleh, Mardiana Idayu Ahmad, Esam Bashir Yahya et al.

Particulate matter (PM) pollution is a significant environmental and public health issue globally. Exposure to high levels of PM, especially fine particles, can have severe health consequences. These particles can come from a variety of sources, including natural events like dust storms and wildfires, as well as human activities such as industrial processes and transportation. Although an extensive development in air filtration techniques has been made in the past few years, fine particulate matter still poses a serios and dangerous threat to human health and to our environment. Conventional air filters are fabricated from non-biodegradable and non-ecofriendly materials which can cause further environmental pollution as a result of their excessive use. Nanostructured biopolymer aerogels have shown great promise in the field of particulate matter removal. Their unique properties, renewable nature, and potential for customization make them attractive materials for air pollution control. In the present review, we discuss the meaning, properties, and advantages of nanostructured aerogels and their potential in particulate matter removal. Particulate matter pollution, types and sources of particulate matter, health effect, environmental effect, and the challenges facing scientists in particulate matter removal are also discussed in the present review. Finally, we present the most recent advances in using nanostructured bioaerogels in the removal of different types of particulate matter and discuss the challenges that we face in these applications.

Haodong Liu, Jinchuang Zhang, Qiongling Chen et al.

Low-moisture (20~40%) and high-moisture (40~80%) textured vegetable proteins (TVPs) can be used as important components of plant-based lean meat, while plant-based fat can be characterized by the formation of gels from polysaccharides, proteins, etc. In this study, three kinds of whole-cut plant-based pork (PBP) were prepared based on the mixed gel system, which were from low-moisture TVP, high-moisture TVP, and their mixtures. The comparisons of these products with commercially available plant-based pork (C-PBP1 and C-PBP2) and animal pork meat (APM) were studied in terms of appearance, taste, and nutritional qualities. Results showed the color changes of PBPs after frying were similar to that of APM. The addition of high-moisture TVP would significantly improve hardness (3751.96~7297.21 g), springiness (0.84~0.89%), and chewiness (3162.44~6466.94 g) while also reducing the viscosity (3.89~10.56 g) of products. It was found that the use of high-moisture TVP led to a significant increase in water-holding capacity (WHC) from 150.25% to 161.01% compared with low-moisture TVP; however, oil-holding capacity (OHC) was reduced from 166.34% to 164.79%. Moreover, essential amino acids (EAAs), the essential amino acids index (EAAI), and biological value (BV) were significantly increased from 272.68 mg/g, 105.52, and 103.32 to 362.65 mg/g, 141.34, and 142.36, respectively, though in vitro protein digestibility (IVPD) reduced from 51.67% to 43.68% due to the high-moisture TVP. Thus, the high-moisture TVP could help to improve the appearance, textural properties, WHC, and nutritional qualities of PBPs compared to animal meat, which was also better than low-moisture TVP. These findings should be useful for the application of TVP and gels in plant-based pork products to improve the taste and nutritional qualities.

Guangyu Yan, Lei Yu, Xiaoting Chen et al.

The low fatization of high-fat foods is a significant trend that will impact the future developments of food products. Consumers have regarded health attributes as a critical indicator for purchasing food. In this study, enzyme-modified soy protein isolate, sea fish collagen, and ovalbumin were used to prepare the composite fat substitute for the protein matrix. This matrix was applied to the traditional surimi-based product <i>Nemipterus virgatus</i> fish sausage to replace the exogenous fat, and a new type of low-fat fish sausage was developed. This change is expected to reduce the exogenous fat in the traditional fish sausage without reducing the flavor and sensory quality of the original product. The results showed that taking the sensory evaluation and gel strength value of the product as indicators, the optimal ratio of compound fat substitute (enzyme-modified soy protein isolate:sea fish collagen:ovalbumin) was 2:1:3 when using the orthogonal test method for the first time. In the next step, with compound fat substitutes, exogenous fats and transglutaminase as the main factors, single factor and response surface method were used to explore the best formula of new low-fat <i>Nemipterus virgatus</i> fish sausage. The results showed that the best gel strength and sensory evaluation scores were obtained when the compound fat substitute, TGase, and exogenous fat were 0.59 g, 0.245 g, and 8.03 g, respectively. The optimal formulation of the low-fat <i>Nemipterus virgatus</i> fish sausage was obtained as follows: surimi, 67.52%; complex fat substitute, 0.66%; TGase, 0.28%; fat, 9.04%; starch, 6.75%; sugar, 3.94%; salt, 2.25%; monosodium glutamate, 0.23%; I&G, 0.34%; and water, 9%. Compared with the traditional fish sausage, the content of exogenous fat in the new, low-fat <i>Nemipterus virgatus</i> fish sausage was reduced by 54.8%. Meanwhile, the sensory score of fish sausage was increased by 21.79%, maintaining its good flavor and sensory quality. This study provides an important reference value for developing new low-fat surimi-based products.

Curtis Runstedler

T. Buchert, Henk van Elst, A. Heinesen

Cosmological models typically neglect the complicated nature of the spacetime mani-fold at small scales in order to hypothesize idealized general relativistic solutions for describing the average dynamics of the Universe. Although these solutions are remarkably successful in accounting for data, they introduce a number of puzzles in cosmology, and their foundational assumptions are therefore important to test. In this paper, we go beyond the usual assumptions in cosmology and propose a formalism for averaging the local general relativistic spacetime on an observer’s past null cone: we formulate average properties of light fronts as they propagate from a cosmological emitter to an observer. The energy-momentum tensor is composed of an irrotational dust source and a cosmological constant—the same components as in the Λ\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\varLambda $$\end{document}CDM model for late cosmic times—but the metric solution is not a priori constrained to be locally homogeneous or isotropic. This generally makes the large-scale dynamics depart from that of a simple Friedmann–Lemaître–Robertson–Walker solution through ‘backreaction’ effects. Our formalism quantifies such departures through a fully covariant system of area-averaged equations on the light fronts propagating towards an observer, which can be directly applied to analytical and numerical investigations of cosmic observables. For this purpose, we formulate light front averages of observable quantities, including the effective angular diameter distance and the cosmological redshift drift and we also discuss the backreaction effects for these observables.

Rubén O. Acuña-Cárdenas, Carlos Gabarrete, O. Sarbach

This article provides a self-contained pedagogical introduction to the relativistic kinetic theory of a dilute gas propagating on a curved spacetime manifold (M, g) of arbitrary dimension. Special emphasis is made on geometric aspects of the theory in order to achieve a formulation which is manifestly covariant on the relativistic phase space. Whereas most previous work has focused on the tangent bundle formulation, here we work on the cotangent bundle associated with (M, g) which is more naturally adapted to the Hamiltonian framework of the theory. In the first part of this work we discuss the relevant geometric structures of the cotangent bundle T∗M\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T^* M$$\end{document}, starting with the natural symplectic form on T∗M\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T^* M$$\end{document}, the one-particle Hamiltonian and the Liouville vector field, defined as the corresponding Hamiltonian vector field. Next, we discuss the Sasaki metric on T∗M\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$T^* M$$\end{document} and its most important properties, including the role it plays for the physical interpretation of the one-particle distribution function. In the second part of this work we describe the general relativistic theory of a collisionless gas, starting with the derivation of the collisionless Boltzmann equation for a neutral simple gas. Subsequently, the description is generalized to a charged gas consisting of several species of particles and the general relativistic Vlasov–Maxwell equations are derived for this system. The last part of this work is devoted to a transparent derivation of the collision term, leading to the general relativistic Boltzmann equation on (M, g). To this end, we introduce the collision manifold, describing the set of all possible binary elastic collisions and discuss its most important geometric properties, including the metric and volume form it is equipped with and its symmetries. We show how imposing full Lorentz symmetry leads to microscopic reversibility and the relativistic H theorem. The meaning of global and local equilibrium and the stringent restrictions for the existence of the former on a curved spacetime are discussed. We close this article with an application of our formalism to the expansion of a homogeneous and isotropic universe filled with a collisional simple gas and its behavior in the early and late epochs.

Yuye Huang, Kailei Xu, Jingyi Liu et al.

Peripheral nerve injuries cause different degrees of nerve palsy and function loss. Due to the limitations of autografts, nerve tissue engineering (TE) scaffolds incorporated with various neurotrophic factors and cells have been investigated to promote nerve regeneration. However, the molecular mechanism is still poorly understood. In this study, we co-cultured Schwann cells (SCs) and rat adrenal pheochromocytoma (PC-12) cells on 50% degrees of methacryloyl substitution gelatin methacrylate (GelMA) scaffold. The SCs were encapsulated within the GelMA, and PC-12 cells were on the surface. A 5% GelMA was used as the co-culture scaffold since it better supports SCs proliferation, viability, and myelination and promotes higher neurotrophic factors secretion than 10% GelMA. In the co-culture, PC-12 cells demonstrated a higher cell proliferation rate and axonal extension than culturing without SCs, indicating that the secretion of neurotrophic factors from SCs can stimulate PC-12 growth and axonal outgrowth. The mRNA level for neurotrophic factors of SCs in 5% GelMA was further evaluated. We found significant upregulation when compared with a 2D culture, which suggested that this co-culture system could be a potential scaffold to investigate the mechanism of how SCs affect neuronal behaviors.

Oscar Castillo-Felisola, Dominic T. Price, Mattia Scomparin

The aim of this work is to present a series of concrete examples which illustrate how the computer algebra system Cadabra can be used to manipulate expressions appearing in General Relativity and other gravitational theories. We highlight the way in which Cadabra's philosophy differs from other systems with related functionality. The use of various new built-in packages is discussed, and we show how such packages can also be created by end-users directly using the notebook interface. The current paper focuses on fairly generic applications in gravitational theories, including the use of differential forms, the derivation of field equations and the construction of their solutions. A follow-up paper discusses more specific applications related to the analysis of gravitational waves.