Hematite nanoparticles have a broad range of outstanding applications such as in wastewater treatment, electrolytic studies, and photoelectrochemical and superparamagnetic applications. Therefore, ...the development of facile and novel methods to synthesize hematite nanoparticles using low-cost raw materials is an important and timely requirement. In this study, we have developed a facile economical route to synthesize hematite nanoparticles, directly from the naturally occurring material laterite. Laterite is a rock that is rich in Fe and Al with extensive distribution in large mineable quantities in many countries around the world, though not yet utilized for major industrial applications. In this method, ferric ions in the laterite were leached out using acid and the solution obtained was hydrolyzed with slow-release hydroxyl ions which were acquired by aqueous decomposition of urea. The resulted precursor was calcined to obtain hematite nanoparticles. Characterization data shows that the final product is comprised of spherical hematite nanoparticles with a narrow particle size
vs.
frequency distribution with an average particle diameter of 35 nm. The synthesized product has a purity of over 98%. Furthermore, the synthesized nanoparticles show an excellent adsorption percentage as high as 70%, even when the initial dye concentration in water is 5000 ppm and the amount of material is minimal, towards acid dyes which are excessively used in textile based industries. Such acid dyes are a threat to the environment when they are released into water bodies by industries in massive quantities. Therefore synthesized hematite nanoparticles are ideal to treat dye wastewater in industrial effluents because such nanoparticles are low cost and economical, and the synthesis procedure is rather facile and effective.
High purity hematite nanoparticles have been synthesized by a facile method using naturally occurring laterites for industrial dye effluent treatment applications.
In recent years, more attention has been paid to natural sources of antioxidants. Flavonoids are natural substances synthesized in several parts of plants that exhibit a high antioxidant capacity. ...They are a large family, presenting several classes based on their basic structure. Flavonoids have the ability to control the accumulation of reactive oxygen species (ROS) via scavenger ROS when they are formed. Therefore, these antioxidant compounds have an important role in plant stress tolerance and a high relevance in human health, mainly due to their anti-inflammatory and antimicrobial properties. In addition, flavonoids have several applications in the food industry as preservatives, pigments, and antioxidants, as well as in other industries such as cosmetics and pharmaceuticals. However, flavonoids application for industrial purposes implies extraction processes with high purity and quality. Several methodologies have been developed aimed at increasing flavonoid extraction yield and being environmentally friendly. This review presents the most abundant natural flavonoids, their structure and chemical characteristics, extraction methods, and biological activity.
Aims
To investigate the effects of the lectin from Punica granatum sarcotesta (PgTeL) on growth, viability, cell structure, biofilm formation and chitinase activity of Listeria monocytogenes. In ...addition, the effect of PgTeL on the adhesion and invasion of human cells (HeLa) was determined.
Methods and Results
PgTeL showed bacteriostatic and bactericidal effects on the strains L. monocytogenes N53‐1 and EGD‐e, causing morphometric alterations, cell aggregation, strong deformation and cell disruption. PgTeL inhibited biofilm formation by EGD‐e and N53‐1 and also interfered with the adhesion and invasion processes of EGD‐e and N53‐1 in HeLa cells. Finally, the chitinase activity of L. monocytogenes EGD‐e was reduced in the presence of PgTeL, which can be involved in the inhibition of adhesion process.
Conclusion
PgTeL is an antibacterial agent against L. monocytogenes, inhibiting growth and promoting cell death, as well as impairing biofilm formation and bacterial adhesion and invasion into human cells.
Significance and Impact of the Study
The results stimulate future investigations on the potential of PgTeL for protection of contamination in food products.
The lectin PgTeL is an antibacterial agent against Listeria monocytogenes, inhibiting growth and promoting cell death, as well as impairing biofilm formation and bacterial adhesion and invasion into human cells.
This living systematic review aims to summarize evidence on the prevalence of oral signs and symptoms in patients with COVID-19. The review was reported per the PRISMA checklist, and the literature ...search was conducted in 6 databases and in gray literature. Studies published in any language mentioning oral symptoms and signs in patients with COVID-19 were included. The risk of bias was assessed by the Joanna Briggs Institute appraisal tools. The certainty of evidence was evaluated through GRADE assessment. After a 2-step selection, 40 studies were included: 33 cross-sectional and 7 case reports. Overall, 10,228 patients (4,288 males, 5,770 females, and 170 unknown) from 19 countries were assessed. Gustatory impairment was the most common oral manifestation, with a prevalence of 45% (95% CI, 34% to 55%; I2 = 99%). The pooled eligible data for different taste disorders were 38% for dysgeusia and 35% for hypogeusia, while ageusia had a prevalence of 24%. Taste disorders were associated with COVID-19 (odds ratio OR, 12.68; 95% CI, 6.41 to 25.10; I2 = 63%; P < 0.00001), mild/moderate severity (OR, 2.09; 95% CI, 1.25 to 3.49; I2 = 66%; P = 0.005), and female patients (OR, 1.64; 95% CI, 1.23 to 2.17; I2 = 70%; P = 0.0007). Oral mucosal lesions presented multiple clinical aspects, including white and erythematous plaques, irregular ulcers, small blisters, petechiae, and desquamative gingivitis. Tongue, palate, lips, gingiva, and buccal mucosa were affected. In mild cases, oral mucosal lesions developed before or at the same time as the initial respiratory symptoms; however, in those who required medication and hospitalization, the lesions developed approximately 7 to 24 d after onset symptoms. Therefore, taste disorders may be common symptoms in patients with COVID-19 and should be considered in the scope of the disease’s onset and progression. Oral mucosal lesions are more likely to present as coinfections and secondary manifestations with multiple clinical aspects (PROSPERO CRD42020184468).
The quest for safer anti‐inflammatory drugs is still the focus of several medicinal chemistry programs. Chromones (4H‐chromen‐4‐ones) are a group of naturally occurring compounds ubiquitous in ...plants, and the chromone core has proven to be a privileged scaffold in medicinal chemistry. Herein we provide an overview of the relevance of chromones as anti‐inflammatory agents, specifically as inhibitors of cyclooxygenase (COX), 5‐lipoxygenase (5‐LOX), interleukin‐5 (IL‐5), and nitric oxide (.NO) production. Numerous structure–activity relationships and mechanisms of action are discussed. This review is therefore intended to provide a foundation for the design and synthesis of novel chromone‐based compound libraries for further development into safer and more efficient anti‐inflammatory agents.
Fact! The chromone nucleus is an important scaffold for the development of anti‐inflammatory agents. Their interactions with important enzymes involved in inflammatory processes and their privileged features are not very well documented. In this minireview we discuss the structure–activity relationships of chromones as well as their mechanisms of action.
•MgO nanoparticles were synthesised using a novel in-situ method.•Chitosan/MgO nanocomposite thin films were fabricated by solution casting method.•The addition of MgO into chitosan resulted in 86% ...improvement in tensile stress.•Chitosan/MgO nanocomposites exhibited higher thermal stability and flame retardancy.•Chitosan with MgO nanoparticles also showed superior UV-shielding abilities.
Chitosan nanocomposite thin films were fabricated by incorporating MgO nanoparticles to significantly improve its physical properties for potential packaging applications. A novel in-situ method was developed to synthesise spherical shaped MgO nanoparticles by heat-treating magnesium carbonate/poly(methyl methacrylate) (PMMA) composite precursor. Optimum mechanical properties of chitosan composites were yielded at 5 (w/w%) of MgO concentration, where tensile stress and elastic modulus significantly improved by 86% and 38%, respectively, compared to those of pure chitosan films. These improvements are due to the interaction of hydroxyl and amine groups of chitosan with MgO as confirmed by FTIR spectroscopy. Fracture surface morphology indicated the interplay between MgO dispersion and aggregation on the mechanical properties at different MgO concentrations. Furthermore, the chitosan/MgO nanocomposites displayed remarkable thermal stability, flame retardant properties (satisfied V0 rating according to the UL-94 standards), UV shielding and moisture barrier properties, which could certainly add value to the packaging material.
Fucales are an order within the Phaeophyceae that include most of the common littoral seaweeds in temperate and subtropical coastal regions. Many species of this order have long been a part of human ...culture with applications as food, feedand remedies in folk medicine. Apart from their high nutritional value, these seaweeds are also a well-known reservoir of multiple bioactive compounds with great industrial interest. Among them, phlorotannins, a unique and diverse class of brown algae-exclusive phenolics, have gathered much attention during the last few years due to their numerous potential health benefits. However, due to their complex structural features, combined with the scarcity of standards, it poses a great challenge to the identification and characterization of these compounds, at least with the technology currently available. Nevertheless, much effort has been taken towards the elucidation of the structural features of phlorotannins, which have resulted in relevant insights into the chemistry of these compounds. In this context, this review addresses the major contributions and technological advances in the field of phlorotannins extraction and characterization, with a particular focus on Fucales.
In the face of increasing bacterial resistance to antibiotics currently in use, the search for new antimicrobial agents has received a boost in recent years, with natural products playing an ...important role in this field. In fact, several methods have been proposed to investigate the antibacterial activities of natural products. However, given that the ultimate aim is future therapeutic use as novel drugs, it is extremely necessary to elucidate their modes of action, stating the molecular effects in detail, and identifying their targets in the bacterial cell. This review analyzes the application of "omics technologies" to understand the antibacterial mechanisms of bioactive natural products, to stimulate research interest in this area and promote scientific collaborations. Some studies have been specifically highlighted herein by examining their procedures and results (targeted proteins and metabolic pathways). These approaches have the potential to provide new insights into our comprehension of antimicrobial resistance/susceptibility, creating new perspectives for the struggle against bacteria, and leading to the development of novel products in the future.
Multifunctional wearable electronic textiles based on interfacial polymerization of polypyrrole on carbon nanotubes/cotton fibers offer advantages of simple and low-cost materials that incorporate ...bactericidal, good electrochemical performance, and electrical heating properties. The high conductivity of doped polypyrrole/CNT composite provides textiles that reaches temperature on order of 70 °C with field of 5 V/cm, superior electrochemical performance applied as electrodes of supercapacitor prototypes, reaching capacitance in order of 30 F g–1 and strong bactericidal activity against Staphylococcus aureus. The combination of these properties can be explored in smart devices for heat and microbial treatment on different parts of body, with incorporated storage of energy on textiles.
Regulated protein secretion is required for malaria parasite life cycle progression and transmission between the mammalian host and mosquito vector. During transmission from the host to the vector, ...exocytosis of highly specialised secretory vesicles, such as osmiophilic bodies, is key to the dissolution of the red blood cell and parasitophorous vacuole membranes enabling gamete egress. The positioning of adhesins from the TRAP family, from micronemes to the sporozoite surface, is essential for gliding motility of the parasite and transmission from mosquito to mammalian host. Here we identify a conserved role for the putative pantothenate transporter PAT in Plasmodium berghei in vesicle fusion of two distinct classes of vesicles in gametocytes and sporozoites. PAT is a membrane component of osmiophilic bodies in gametocytes and micronemes in sporozoites. Despite normal formation and trafficking of osmiophilic bodies to the cell surface upon activation, PAT-deficient gametes fail to discharge their contents, remain intraerythrocytic and unavailable for fertilisation and further development in the mosquito. Sporozoites lacking PAT fail to secrete TRAP, are immotile and thus unable to infect the subsequent rodent host. Thus, P. berghei PAT appears to regulate exocytosis in two distinct populations of vesicles in two different life cycle forms rather than acting as pantothenic transporter during parasite transmission.
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