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Bioprocess and Biosystems Engineering Feb 2021Schizophyllum commune is a wood-rotting filamentous fungus that secrets a homopolysaccharide called as schizophyllan. Schizophyllan has several applications such as...
Schizophyllum commune is a wood-rotting filamentous fungus that secrets a homopolysaccharide called as schizophyllan. Schizophyllan has several applications such as enhanced oil recovery, pharmaceutical materials and an anti-cancer drug carrier. Biomass growth and schizophyllan production increase the viscosity of the cultivation medium, thus resulting in mass transfer limitation for the substrate. In this study, adding talc and aluminium oxide microparticles into the cultivation medium was studied to improve the fungal growth and morphology. The response surface methodology and one factor at a time were applied to find the effects of microparticles with different sizes and concentrations on the schizophyllan production. The optimum concentration and size of aluminium oxide microparticles were obtained as 20 g L and < 30 µm, respectively. Aluminium oxide microparticles in shake flask culture caused to increase the schizophyllan production from 10 to 15 g L and decrease the cultivation time from 10 to 7 days. The production yield also increased from 0.11 to 0.30 g of schizophyllan/g glucose. Bioreactor cultivation showed a twofold increase in schizophyllan production from 1.5 to 3 g L. The results of this study suggested a significant increase in the production of schizophyllan using a low-cost "microparticle-enhanced cultivation" without any further optimization of the culture medium.
Topics: Aluminum Oxide; Biomass; Bioreactors; Culture Media; Schizophyllum; Sizofiran; Talc
PubMed: 32955618
DOI: 10.1007/s00449-020-02444-z -
ACS Applied Materials & Interfaces Sep 2022Preventing crystallization is a primary concern when developing amorphous drug formulations. Recently, atomic layer coatings (ALCs) of aluminum oxide demonstrated...
Preventing crystallization is a primary concern when developing amorphous drug formulations. Recently, atomic layer coatings (ALCs) of aluminum oxide demonstrated crystallization inhibition of high drug loading amorphous solid dispersions (ASDs) for over 2 years. The goal of the current study was to probe the breadth and mechanisms of this exciting finding through multiple drug/polymer model systems, as well as particle and coating attributes. The model ASD systems selected provide for a range of hygroscopicity and chemical functional groups, which may contribute to the crystallization inhibition effect of the ALC coatings. Atomic layer coating was performed to apply a 5-25 nm layer of aluminum oxide or zinc oxide onto ASD particles, which imparted enhanced micromeritic properties, namely, reduced agglomeration and improved powder flowability. ASD particles were stored at 40 °C and a selected relative humidity level between 31 and 75%. Crystallization was monitored by X-ray powder diffraction and scanning electron microscopy (SEM) up to 48 weeks. Crystallization was observable by SEM within 1-2 weeks for all uncoated samples. After ALC, crystallization was effectively delayed or completely inhibited in some systems up to 48 weeks. The delay achieved was demonstrated regardless of polymer hygroscopicity, presence or absence of hydroxyl functional groups in drugs and/or polymers, particle size, or coating properties. The crystallization inhibition effect is attributed primarily to decreased surface molecular mobility. ALC has the potential to be a scalable strategy to enhance the physical stability of ASD systems to enable high drug loading and enhanced robustness to temperature or relative humidity excursions.
Topics: Aluminum Oxide; Crystallization; Drug Stability; Polymers; Powders; Solubility
PubMed: 36054111
DOI: 10.1021/acsami.2c12666 -
The Journal of Prosthetic Dentistry Oct 2022Ceria-stabilized zirconia-alumina nanocomposite (Ce-TZP-AlO) has properties that may be suitable for partial denture frameworks. However, studies on its adhesion...
STATEMENT OF PROBLEM
Ceria-stabilized zirconia-alumina nanocomposite (Ce-TZP-AlO) has properties that may be suitable for partial denture frameworks. However, studies on its adhesion strength and durability with denture base resin are lacking.
PURPOSE
The purpose of this in vitro study was to determine the optimal surface treatment for Ce-TZP-AlO to secure a durable bond with an acrylic resin.
MATERIAL AND METHODS
The surface of Ce-TZP-AlO test specimens was alumina airborne-particle abraded (Group APA) and then treated with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) (Group MDP) and 2 silica coating methods: the flame spraying method (Group SLP) and the tribochemical treatment (110 μm: Group TRB-P, 30 μm: Group TRB-S). TRB-P and TBR-S were further treated by MDP (Group CBT-P and CBT-S). Autopolymerizing acrylic resin was bonded to the specimens, and the shear bond strength was tested after thermocycling (5 °C and 60 °C, 10 000 cycles). The area of the resin remaining on the fractured surfaces was also measured. To evaluate the effect of the surface treatment condition on shear bond strength and the resin remaining, 1-way analysis of variance (ANOVA) was conducted, followed by the Tukey multiple comparison post hoc test. Additionally, the effect of thermocycling on the specimens was evaluated by the Student t test.
RESULTS
After placement in deionized water for 24 hours, the shear bond strengths of Group MDP and 2 types of combination treatment (Groups CBT-P and CBT-S) were significantly higher than those of Groups SLP, TRB-P, and TRB-S (P<.05). Moreover, the fractured surface of all the treatment conditions except Group APA showed cohesive failure. The shear bond strength as a result of all treatment conditions decreased significantly after thermocycling (P<.05). Group CBT-S showed the highest shear bond strength; however, no significant differences were found between Groups CBT-S and MDP (P=.908). In particular, the area of resin remaining on the fractured surfaces of Group CBT-S was 100% (cohesive failure).
CONCLUSIONS
The combined surface treatment of alumina airborne-particle abrasion and tribochemical treatment, along with primer treatment using silane coupling and an MDP monomer, improved the adhesion strength and adhesion durability between base resins and Ce-TZP-AlO.
Topics: Humans; Aluminum Oxide; Resin Cements; Dental Bonding; Acrylic Resins; Surface Properties; Materials Testing; Zirconium; Shear Strength; Nanocomposites; Dental Stress Analysis
PubMed: 33731268
DOI: 10.1016/j.prosdent.2021.01.019 -
Scientific Reports May 2021Ceramic orthopaedic implants are increasingly popular due to the need for robust total joint replacement implants that have a high success rate long-term and do not...
Ceramic orthopaedic implants are increasingly popular due to the need for robust total joint replacement implants that have a high success rate long-term and do not induce biological responses in patients. This study was designed to investigate the biological effects of ceramic nanopowders containing aluminium oxide or zirconium oxide to activate the human macrophage THP-1 cell line. In vitro investigation of pro-inflammatory gene expression and chemokine secretion was performed studied using RT-qPCR and ELISA, respectively. TLR4 inhibition, using a small-molecule inhibitor, was used to determine whether ceramic-mediated inflammation occurs in a similar manner to that of metals such as cobalt. THP-1 macrophages were primed with ceramics or LPS and then treated with ATP or ceramics, respectively, to determine whether these nanopowders are involved in the priming or activation of the NLRP3 inflammasome through IL-1β secretion. Cells treated with ceramics significantly increased pro-inflammatory gene expression and protein secretion which was attenuated through TLR4 blockade. Addition of ATP to cells following ceramic treatment significantly increased IL-1β secretion. Therefore, we identify the ability of ceramic metal oxides to cause a pro-inflammatory phenotype in THP-1 macrophages and propose the mechanism by which this occurs is primarily via the TLR4 pathway which contributes to inflammasome signalling.
Topics: Aluminum Oxide; Arthroplasty, Replacement, Hip; Cell Proliferation; Cell Survival; Ceramics; Gene Expression Regulation; Humans; Inflammation; Inflammation Mediators; Macrophages; Nanoparticles; Phagocytosis; Powders; THP-1 Cells; Toll-Like Receptor 4; Zirconium
PubMed: 34006936
DOI: 10.1038/s41598-021-89329-7 -
Bulletin of Environmental Contamination... Jul 2022
Topics: Aluminum Oxide; Soil
PubMed: 35789281
DOI: 10.1007/s00128-022-03578-4 -
Sensors (Basel, Switzerland) Sep 2020This review paper focuses on recent progress in optical biosensors using self-ordered nanoporous anodic alumina. We present the fabrication of self-ordered nanoporous... (Review)
Review
This review paper focuses on recent progress in optical biosensors using self-ordered nanoporous anodic alumina. We present the fabrication of self-ordered nanoporous anodic alumina, surface functionalization, and optical sensor applications. We show that self-ordered nanoporous anodic alumina has good potential for use in the fabrication of antibody-based (immunosensor), aptamer-based (aptasensor), gene-based (genosensor), peptide-based, and enzyme-based optical biosensors. The fabricated optical biosensors presented high sensitivity and selectivity. In addition, we also showed that the performance of the biosensors and the self-ordered nanoporous anodic alumina can be used for assessing biomolecules, heavy ions, and gas molecules.
Topics: Aluminum Oxide; Biosensing Techniques; Electrodes; Eye; Nanopores
PubMed: 32906635
DOI: 10.3390/s20185068 -
Environmental Science and Pollution... Apr 2024In aluminum electrolysis, the iron-rich cover material is formed on the cover material and the steel rod connecting the carbon anode. Due to the high iron content in the...
In aluminum electrolysis, the iron-rich cover material is formed on the cover material and the steel rod connecting the carbon anode. Due to the high iron content in the iron-rich cover material, it differs from traditional cover material and thus requires harmless recycling and treatment. A process was proposed and used in this study to recovery F, Al, and Fe elements from the iron-rich cover material. This process involved aluminum sulfate solution leaching for fluorine recovery and alkali-acid synergistic leaching for α-AlO and FeO recovery were obtained. The optimal leaching rates for F, Na, Ca, Fe, and Si were 93.92, 96.25, 94.53, 4.48, and 28.87%, respectively. The leaching solution and leaching residue were obtained. The leaching solution was neutralized to obtain the aluminum hydroxide fluoride hydrate (AHFH, AlF(OH)·(HO)). AHFH was calcined to form a mixture of AlF and AlO with a purity of 96.14%. The overall recovery rate of F in the entire process was 92.36%. Additionally, the leaching residue was sequentially leached with alkali and acid to obtain the acid leach residue α-AlO. The pH of the acid-leached solution was adjusted to produce a black-brown precipitate, which was converted to FeO under a high-temperature calcination, and the recovery rate of Fe in the whole process was 94.54%. Therefore, this study provides a new method for recovering F, Al, and Fe in iron-rich cover material, enabling the utilization of aluminum hazardous waste sources.
Topics: Ferric Compounds; Electrolysis; Aluminum; Fluorides; Aluminum Oxide; Iron; Aluminum Compounds; Recycling
PubMed: 38512573
DOI: 10.1007/s11356-024-32877-y -
ACS Chemical Neuroscience Dec 2022Studies demonstrated that alumina nanoparticles (alumina NPs) impair spatial cognition and hippocampus-dependent synaptic plasticity. Although alumina NPs accumulate in...
Studies demonstrated that alumina nanoparticles (alumina NPs) impair spatial cognition and hippocampus-dependent synaptic plasticity. Although alumina NPs accumulate in the prefrontal cortex (PFC), their effects on PFC-mediated neuronal and cognitive function have been not yet documented. Here, alumina NPs (10 or 20 μg/kg of body weight) were bilaterally injected into the medial PFC (mPFC) of adult rats, and the levels of glycogen synthase kinase 3β (GSK3β) and the brain-derived neurotrophic factor (BDNF) were detected. The PFC-dependent working memory task with one-minute or three-minute delay time was conducted. Meanwhile, the neuronal correlates of working memory performance were recorded. The specific expression of neuronal BDNF was assessed by colabeled BDNF expression with the neuronal nuclear antigen (NeuN). Whole-cell patch-clamp recordings were employed to detect neuronal excitability. Intra-mPFC alumina NP infusions significantly enhanced the expression of GSK3β but reduced the phosphorylation of GSK3β (pGSK3β) and BDNF levels more severely at a dose of 20 μg/kg. Alumina NPs acted in a dose-dependent manner to impair working memory. The neuronal expression of BDNF in the 20 μg/kg group was markedly declined compared with the 10 μg/kg group. During the delay time, the neuronal frequency of pyramidal cells but not interneurons was significantly weakened. Furthermore, both the frequency and amplitude of the excitatory postsynaptic currents (EPSCs) were descended in the mPFC slices. Additionally, the infusion of GSK3β inhibitor SB216763 or BDNF could effectively attenuate the impairments in neuronal correlate, neuronal activity, and working memory. From the perspective of the identified GSK3β/BDNF pathway, these findings demonstrated for the first time that alumina NPs exposure can be a risk factor for prefrontal neuronal and cognitive functions.
Topics: Animals; Rats; Aluminum Oxide; Brain-Derived Neurotrophic Factor; Memory, Short-Term; Prefrontal Cortex; Signal Transduction
PubMed: 36444509
DOI: 10.1021/acschemneuro.2c00383 -
Nature Materials Jul 2023III-nitride wide bandgap semiconductors are promising materials for modern optoelectronics and electronics. Their application has progressed greatly thanks to the...
III-nitride wide bandgap semiconductors are promising materials for modern optoelectronics and electronics. Their application has progressed greatly thanks to the continuous quality improvements of heteroepitaxial films grown on large-lattice-mismatched foreign substrates. But compared with bulk single crystals, there is still tremendous room for the further improvement of the material quality. Here we show a paradigm to achieve high-quality III-nitride heteroepitaxial films by the controllable discretization and coalescence of columns. By adopting nano-patterned AlN/sapphire templates with regular hexagonal holes, discrete AlN columns coalesce with uniform out-of-plane and in-plane orientations guaranteed by sapphire nitridation pretreatment and the ordered lateral growth of cleavage facets, which efficiently suppresses the regeneration of threading dislocations during coalescence. The density of dislocation etch pits in the AlN heteroepitaxial film reaches 3.3 × 10 cm, close to the present available AlN bulk single crystals. This study facilitates the growth of bulk-class quality III-nitride films featuring low cost and scalability.
Topics: Aluminum Oxide; Electronics; Semiconductors; Software
PubMed: 37349395
DOI: 10.1038/s41563-023-01573-6 -
Water Science and Technology : a... Mar 2023Although spinel ferrite (MFeO, M = Zn, Ni, Mn, etc.) has been reported as a promising catalyst, its low photocatalytic activity under visible light greatly restricts its... (Review)
Review
Although spinel ferrite (MFeO, M = Zn, Ni, Mn, etc.) has been reported as a promising catalyst, its low photocatalytic activity under visible light greatly restricts its practical application. Spinel ferrite-based photocatalytic composites have exhibited improved efficiency for pollutant degradation, due to interface charge carrier mobility and structural modification. Meanwhile, due to its magnetism and stability, spinel ferrite composite can be easily recycled for long-term utilization, showing its high application potential. In this review, the recent advances in the construction and photocatalytic degradation of spinel ferrite composites are discussed, with an emphasis on the relationship between structural property and photocatalytic activity. In addition, to improve their photocatalytic application, the challenges, gaps and future research prospects are proposed.
Topics: Aluminum Oxide; Environmental Pollutants; Light
PubMed: 37001160
DOI: 10.2166/wst.2023.077