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The existence of the organic component (MA) in MAPbBr3 guarantees its cubic crystal lattice stabilities to satisfy the tolerance factor but increases the chemical instability risk when encountering moisture, oxidation, and heat. Mixed cations, particularly when using cesium cation (Cs+), prove to be an effective way of improving both stability and optoelectronic performances of hybrid perovskite films applied in solar cells. However, the intrinsic effect of Cs+ on the crystal structure, lattice defects, and optoelectronic properties of MAPbBr3 is still unclear till now because grain boundary numbers and interface defect densities in films increase complexity; so, it is not easy to explore the intrinsic nature of how Cs+ affects the optoelectronic properties of MAPbBr3. Single crystals (SCs) of MAPbBr3 provide an ideal medium to investigate the influence of Cs+ on the crystal structure and optoelectronic performances. Herein, we grew a series of MA1–xCsxPbBr3 SCs. This reveals that Cs+ inhibits the growth ...

The reuse of mining waste-rocks as construction material constitutes an innovative management approach consistent with the principles of sustainable development. Nevertheless, the implementation of this approach is still limited by most guidelines due principally to insufficient knowledge of these materials performances and to unjustified presumptions related to their chemical instability (presence of sulfide). This paper approaches these issues by assessing the reuse potential of low-sulfide mining waste-rocks as aggregates for concrete regarding to the Quebec (Canada) recycling guidelines of non-hazardous inorganic wastes as construction materials. Toxicity characteristic leaching procedure (TCLP), comprehensive physical, chemical (XRF and ICP-AES) and mineralogical investigations (XRD and SEM) as well as modern automated mineral liberation analyses have been carried out. In addition, UCS results of various concrete mixtures using different binders were then presented to illustrate the reuse potential of the waste-rocks. The TCLP test showed the nonhazardous character of the waste rocks. They contained low sulfide content (0.5 wt%), which classify them as non-acid generating and able to meet the classification in recycling category including concrete production. Moreover, liberation analyses showed that most sulfides are concentrated in the fine fraction as pyrite occurrence with a liberated fraction of only 2%. These results influenced significantly the properties of the resulting concretes, which presented good mechanical performances especially when coarse waste rock above 20 mm and fine one below 80 μm was removed.

The dendritic electrodeposition of lithium, leading to physical orphaning and chemical instability, is considered responsible for the poor reversibility and premature failure of electrochemical cel...

The interest of food industry to merchandise natural astaxanthin is growing up. However, it confronts scientific and technological challenges mainly related to its poor water solubility and chemical instability. Here, we present a new quick and efficient green process to simultaneously extract, encapsulate and stabilize astaxanthin from Haematococcus pluvialis. The process is based on the hitherto unexplored combination of supramolecular solvents (SUPRAS), nanostructured liquids generated from amphiphiles through sequential self-assembly and coacervation, and nanostructured lipid carriers (NLCs). These novel nanosystems were characterized by means of dynamic light scattering, AFM and cryoSEM, revealing spherical particles of ∼100 nm. Their antioxidant activity was measured by ORAC (20.6 ± 3.9 μM TE) and α-TEAC (2.92 ± 0.58 µM α-TE) assays and their in vitro capacity to inhibit ROS by DHE probe. Results showed that the SUPRAS-NLCs proposed yield high extraction and encapsulation efficiencies (71 ± 4%) in combination with a remarkable time stability (180 d, 4 °C).

Background and Objective: Infusion containing lorazepam is used by geriatric department to limit anxiety disorders in the elderly. Currently, these infusions are prepared according to demand by the nursing staff, but the preparation in advance in a centralized service could improve quality of preparation and time management. The aim of this study was to investigate the long-term stability of this infusion in polypropylene syringes stored at 5 ± 3°C. Then, results obtained were compared with stability data of lorazepam in syringes stored at room temperature, glass bottles at 5 ± 3°C, and glass bottles at room temperature. Method: Eight syringes and 6 bottles of infusion were prepared by diluting 1 mL lorazepam 4 mg in 23 mL of NaCl 0.9% under aseptic conditions. Five syringes and 3 bottles were stored at 5 ± 3°C and 3 syringes and 3 bottles were stored at room temperature for 30 days. During the storage period, particle appearance or color change were periodically checked by visual and microscope inspection. Turbidity was assessed by measurements of optical density (OD) at 3 wavelengths (350 nm, 410 nm, 550 nm). The stability of pH was also evaluated. The lorazepam concentrations were measured at each time point by high-performance liquid chromatography with ultraviolet detector at 220 nm. Results: Solutions were physically unstable in syringes at 5 ± 3°C after 4 days: crystals and a drop of OD at 350 nm were observed. However, pH was stable. After 2 days, solutions were considered as chemically unstable because a loss of lorazepam concentration higher than 10% was noticed: the lower 1-sided confidence limit at 95% was below 90% of the initial concentration. To assess temperature and polypropylene influence, results were compared with those obtained for syringes at room temperature and bottles at 5 ± 3°C and room temperature. Precipitation, drop of OD at 350 nm, and chemical instability were observed in all conditions. Conclusion: Solutions of lorazepam were unstable after 2 days in syringes at 5 ± 3°C. Preparation in advance appears, therefore, not possible for the clinical use. Storage conditions (temperature and form) do not improve the stability.

Inorganic halide perovskites (IHPs) have recently attracted huge attention in the field of optoelectronics. IHPs are generally expected to exhibit superior chemical stability over the prevailing hybrid organic–inorganic perovskites that are widely used in optoelectronic devices such as solar cells and light-emitting devices. This is primarily owing to the elimination of weakly-bonded organic components in the IHP crystal structure. Nevertheless, many recent studies have revealed that IHPs still suffer significant issues in chemical instability, and thus, a lot of effort has been made towards the stabilization of IHPs for high-performance devices. In this context, a great deal of interest in the chemistry and perovskite community has been emerging to understand the chemical (in)stability of IHPs and develop engineering strategies for making more robust perovskite devices. This review will summarize the past research progress in this direction, give insights into the IHP (in)stability, and provide perspectives for the future effort in making stable IHP materials and devices.

Perovskite solar cells (PSCs) have attracted tremendous interest because of their rapid improvement in power conversion efficiency (PCE) from the initial PCE of 3.8% for the first prototype to the certified PCE of 25.2% in 2019. However, the inherent chemical instability of organic–inorganic hybrid perovskite halides influenced by moisture, heat and ultraviolet light is still a critical issue for them to meet application-specific requirements owing to the weak-bonded organic components in the hybrid crystal structure. The use of all-inorganic perovskites CsPbI3−xBrx (x = 0, 1, 2, and 3) as light-harvesters by completely substituting organic species with inorganic Cs+ ions has been recently regarded as a promising solar conversion technology. Since the initial efficiency of 2.9% achieved in 2015, the highest PCE record for inorganic PSCs has risen to 18.4% through structure optimization, compositional engineering, interfacial engineering, solvent control and surface passivation, etc. This article is dedicated to providing an up-to-date review on the development of inorganic PSCs tailored by various inorganic perovskite materials with gradually changed optical properties and stability, as well as the film-making methods and interfacial engineering technologies. Their limited efficiencies in theory and recombination mechanisms are also predicted with a detailed balance model. Finally, we focused on the state-of-the-art strategies for enhancing the photovoltaic performance and identified new challenges and outlooks for future studies in this field.

Background The increased demand by consumers for clean labels has encouraged industry to search for replacements of synthetic ingredients in food products, and in particular, colorants. Lutein, a xanthophyll found in marigolds and corn, can be used in food products as a natural colorant replacing yellow food dyes. Moreover, lutein is considered a nutraceutical due to its potentially beneficial health effects, such as prevention of macular degeneration, role in the development of the visual and nervous systems of fetuses, and its antioxidant properties. However, incorporation of lutein into foods is often limited because of its low-water solubility, chemical instability, and poor oral bioavailability. For this reason, colloidal encapsulation systems have been developed to facilitate the incorporation of lutein into aqueous food and beverage products. Scope and approach This review focuses on exploring encapsulation options for lutein using various emulsion-based, nanoparticle- and microparticle-based and molecular inclusion encapsulation systems, as well as additives that can be used to increase its chemical stability in these systems. This review covers all aspects of lutein encapsulation, including both food-grade and pharmaceutical-grade encapsulation systems. Key findings and conclusions Though lutein-loaded encapsulation systems are extensively explored in this review, emulsions are of the most interest in industry as they are cost efficient and can be designed to increase the stability of lutein by selecting the proper emulsifiers and emulsification techniques. Despite the extensive amount of research carried out on the encapsulation of hydrophobic bioactive molecules such as lutein, there are still opportunities to develop encapsulation systems that further protect these molecules during storage and also increase their bioavailability after ingestion.

Today, due to the prevalence of various diseases such as the novel coronavirus (SARS-CoV-2), diabetes, central nervous system diseases, cancer, cardiovascular disorders, and so on, extensive studies have been conducted on therapeutic properties of natural and synthetic agents. A literature review on herbal medicine and commercial products in the global market showed that curcumin (Cur) has many therapeutic benefits compared to other natural ingredients. Despite the unique properties of Cur, its use in clinical trials is very limited. The poor biopharmaceutical properties of Cur such as short half-life in plasma, low bioavailability, poor absorption, rapid metabolism, very low solubility (at acidic and physiological pH), and the chemical instability in body fluids are major concerns associated with the clinical applications of Cur. Recently, nanoformulations are emerging as approaches to develop and improve the therapeutic efficacy of various drugs. Many studies have shown that Cur nanoformulations have tremendous therapeutic potential against various diseases such as SARS-CoV-2, cancer, inflammatory, osteoporosis, and so on. These nanoformulations can inhibit many diseases through several cellular and molecular mechanisms. However, successful long-term clinical results are required to confirm their safety and clinical efficacy. The present review aims to update and explain the therapeutic potential of Cur nanoformulations.

Aim: This systematic review aims to identify and interpret results of studies that evaluated the changes in the color stability of maxillofacial prosthetic materials due to chemical instability of silicones and pigments and the effect of exposure to environmental conditions and aging factors on the same. Settings and Design: This systematic review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines (PRISMA). Materials and Methods: Relevant articles written in English only, before November 15, 2019, were identified using an electronic search in the PubMed/Medline conducted to identify pertinent articles. The relevancy of the articles was verified by screening the title, abstract, and full text, if they met the inclusion criteria. A total of 42 articles satisfied the criteria, from which data were extracted for qualitative synthesis. This review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO registration number CRD42019124562). Statistical Analysis Used: Since considerable data heterogenicity was present in all studies except the ones on incorporation of TiO2 for which meta-analysis using random effects model was performed. Results: The database search resulted in 234 studies, of which 202 articles were excluded due to lack of relevance, duplication, and unavailability of data. The remaining 32 fulltext articles were assessed for eligibility, out of which 2 articles were excluded. Twelve articles were yielded by manual search. A total of 42 studies were included in the present systematic review. Due to heterogeneous data, meta-analysis could be only carried out with the effect of TiO2 nano particle on color stability. Conclusions: Although there has been extensive amount of research in this field, an ideal maxillofacial silicone exhibiting good color stability in various human and environmental aging conditions is yet to be identified. Human and environmental aging conditions have an adverse effect on the color stability and addition of TiO2 nano particle seems to improve the same.

Utilization of β-carotene in functional food products is limited due to chemical instability, lower water-solubility, and higher melting point. The present research was designed to formulate a nanoemulsion system for the effective delivery of β-carotene. β-Carotene was successfully incorporated into nanoemulsions using the ultrasonication method. During 60 days of storage, the droplet size of β-carotene-containing nanoemulsions varied from 112.36 to 133.9 nm at 4 °C and from 112.36 to 147.1 nm at 25 °C. The oxidation stability of olive oil was remarkably increased when incorporated into nanoemulsions. β-Carotene nanoemulsions remained stable under varying ionic strengths (50-400 mM), pH values (2-8), and freeze-thaw cycles (four). The values of turbidity and total color difference increased over time and at a higher temperature. Degradation of β-carotene was substantially slower in nanoemulsions, and the addition of antioxidants significantly increased the retention of β-carotene in nanoemulsions. These findings suggest that the ultrasonic homogenization method has potential for the preparation of β-carotene nanoemulsions with desirable properties. These nanoemulsions can be effectively used for the incorporation of β-carotene in the food and beverage industry.

Cannabis is an excellent natural source of fiber and various bioactive cannabinoids. So far, at least 120 cannabinoids have been identified, and more novel cannabinoids are gradually being unveiled by detailed cannabis studies. However, cannabinoids in both natural and isolated forms are especially vulnerable to oxygen, heat, and light. Therefore, a diversity of cannabinoids is associated with their chemical instability to a large extent. The research status of structural conversion of cannabinoids is introduced. On the other hand, the use of drug-type cannabis and the phytocannabinoids thereof has been rapidly popularized and plays an indispensable role in both medical therapy and daily recreation. The recent legalization of edible cannabis further extends its application into the food industry. The varieties of legal edible cannabis products in the current commercial market are relatively monotonous due to rigorous restrictions under the framework of Cannabis Regulations and infancy of novel developments. Meanwhile, patents/studies related to the safety and quality assurance systems of cannabis edibles are still rare and need to be developed. Furthermore, along with cannabinoids, many phytochemicals such as flavonoids, lignans, terpenoids, and polysaccharides exist in the cannabis matrix, and these may exhibit prebiotic/probiotic properties and improve the composition of the gut microbiome. During metabolism and excretion, the bioactive phytochemicals of cannabis, mostly the cannabinoids, may be structurally modified during enterohepatic detoxification and gut fermentation. However, the potential adverse effects of both acute and chronic exposure to cannabinoids and their vulnerable groups have been clearly recognized. Therefore, a comprehensive understanding of the chemistry, metabolism, toxicity, commercialization, and regulations regarding cannabinoid edibles is reviewed and updated in this contribution.

There is increasing interest in the use of natural preservatives (rather than synthetic ones) for maintaining the quality and safety of foods due to their perceived environmental and health benefits. In particular, plant-based antimicrobials are being employed to protect against microbial spoilage, thereby improving food safety, quality, and shelf-life. However, many natural antimicrobials cannot be utilized in their free form due to their chemical instability, poor dispersibility in food matrices, or unacceptable flavor profiles. For these reasons, encapsulation technologies, such as nanoemulsions, are being developed to overcome these hurdles. Indeed, encapsulation of plant-based preservatives can improve their handling and ease of use, as well as enhance their potency. This review highlights the various kinds of plant-based preservatives that are available for use in food applications. It then describes the methods available for forming nanoemulsions and shows how they can be used to encapsulate and deliver plant-based preservatives. Finally, potential applications of nano-emulsified plant-based preservatives for improving food quality and safety are demonstrated in the meat, fish, dairy, and fresh produce areas.

Objective Nanotechnology has progressed significantly and particles as small as 3 nm are being employed in resin-based restorative materials to improve clinical performance. The goal of this review is to report the progress of nanotechnology in Restorative Dentistry by reviewing the advantages, limitations, and applications of resin-based restorative materials with nanoparticles. Materials and methods A literature review was conducted using PubMed/Medline, Scopus and Embase databases. In vitro, in vivo and in situ research studies published in English between 1999 and 2020, and which focused on the analysis of resin-based restorative materials containing nanoparticles were included. Results A total of 140 studies were included in this review. Studies reported the effect of incorporating different types of nanoparticles on adhesive systems or resin composites. Mechanical, physical, and anti-bacterial properties were described. The clinical performance of resin-based restorative materials with nanoparticles was also reported. Conclusions The high surface area of nanoparticles exponentially increases the bioactivity of materials using bioactive nanofillers. However, the tendency of nanoparticles to agglomerate, the chemical instability of the developed materials and the decline of rheological properties when high ratios of nanoparticles are employed are some of the obstacles to overcome in the near future. Clinical significance In spite of the recent advancements of nanotechnology in resin-based restorative materials, some challenges need to be overcome before new nano-based restorative materials are considered permanent solutions to clinical problems.

Metal–organic frameworks are a class of functional porous materials. In recent years, metal–organic frameworks have become a hot research topic in the field of electrochemistry because of their high specific surface area, abundant pores, controllable morphology and versatility. In this review, one-dimensional, two- dimensional, hierarchical, hybrid metal–organic frameworks are briefly introduced. The multiscale control of metal–organic framework structure can be realized by designing reasonable synthetic routes. By combining metal-organic frameworks with a variety of functional materials, the chemical instability and poor conductivity of metal-organic frameworks can be overcome. Finally, based on the reported literature, we propose the future direction of metal–organic frameworks and metal–organic framework composites in the field of electrochemistry.

Improving the nutritional value of food can enhance the quality of living and life expectancy. The increasing percentage of diseased and unhealthy population demands the improvement of food quality by adding nutrients having pharmaceutical property to prevent commonly developed diet-associated diseases. Nutraceutical treasure containing vitamins, antioxidants, stanols, sterols, poly unsaturated fatty acids, carotenoids, minerals, fibres, and biologically substantial peptides possess exceptional ability to treat highly prevalent diseases like osteoporosis, cancer, cardiovascular diseases, obesity, diabetes, and arthritis. Although the value of these nutraceuticals is immense, but their low bioavailability, chemical instability, and undesired flavour pose a great challenge. The science of nanotechnology has recently been amalgamated with food science. Miniaturizing nutraceuticals to nanoscale for in-vivo delivery has shown highly promising outcomes and seems to be an advantageous approach in this concern.

Cost-effective and environment-friendly energy storage device is major concern to reduce environment pollution which is major source of fossil fuels. Rechargeable batteries and super capacitor are the promising storage devices used to provide power because of their high energy and power densities, and because of limited power densities of the batteries, it has been restricted in use of electric vehicles and hybrid electric vehicles. So, to enhance the performance of these storage devices, nanotechnology and nanomaterials will play very crucial role in present energy sector. Because of fast diffusion of ions and high particle volume, improved electronic conductivity provided by nanomaterials leads to high current, which is very promising candidate for high energy and power storage. Because of versatile nature of nanomaterials limitations like high reactivity, chemical instability can be overcome by fictionalization of their surfaces and their synthesis process. Present chapter discusses the synthesis methods of nanomaterials, and their application in energy-related application will focus more towards batteries and super capacitor. Chapter also discussed the potential of nanomaterials incorporated into biomasses and hydrogen storage as an aid or addictive to enhance the efficiency of bioenergy storage and conversion. Nanomaterials contribute to better performance of biofuels, biodiesel, and hydrogen production. In addition to prominence, the obvious advantages of nanomaterials and their limitations and challenges of nanomaterials while being used for batteries and super capacitor systems have also been elaborated in this chapter.

Adding phlorotannins (a group of potent antioxidant and antimicrobial compounds derived from seaweed) to food products is certainly an interesting strategy to diversify the highly demanded functional foods by health-conscious consumers. However, many technological processes (from extraction to food processing and storage) may affect the phlorotannins stability and thus, their biological activity. Therefore, encapsulation of phlorotannins through electrospraying may serve as a solution to overcome the potential problems arising from chemical instability, as this innovative technology does not involve high temperature. In this context, we describe here two important protocols that allow obtaining a high recovery of phlorotannins from Ascophyllum nodosum with maximized antioxidant activity (through an optimized microwave-assisted extraction procedure) and also, the stabilization of phlorotannins extract-containing inulin microcapsules (through an encapsulation methodology based on electrospraying) that ensures the maintenance of the phlorotannins’ active molecular form up to the consumption time and their safe arrival to the gut. Physicochemical, mechanical, and thermal characterization of the developed electrosprayed microcapsules is also presented.

In recent years, due to the instability of perovskite, the road of commercialization is very difficult. First of all, this paper summarizes the two important factors affecting the stability, namely intrinsic and chemical instability, which can be specifically water, oxygen, temperature, light and so on. Secondly, the main methods to improve the stability of perovskite materials are summarized, including internal optimization and external optimization, such as crystallization regulation, doping control, additive addition and so on. Finally, the summary and Prospect of practical application in this field are given.

Catanionic nanovesicles are attractive as a novel class of delivery vehicle because they can increase the stability, adsorption, and cellular uptake of a broad range of drugs. These hybrid lipid nanocarriers consist of solid and liquid lipids, which are biocompatible and biodegradable. Since liquid lipid is added to the nanocarrier, the lipids are present in a crystalline defect or amorphous structure state. As a result, hybrid lipid nanocarriers have a higher drug loading capability and suffer less drug leakage during preparation and storage compared to the pure lipid nanocarriers. Catanionic nanovesicles have been shown to increase stability, adsorption, cellular uptake, apoptosis induction, tumor cell cytotoxicity, and antitumorigenic effect, making it a highly desirable vehicle for drug delivery. For example, the anticancer compound curcumin (CC) have shown great promise to cure cancers such as lung cancer, breast cancer, stomach cancer, and colon cancer. However, like many potential antitumor drugs, CC on its own has poor water solubility, easy photodegradation, chemical instability, low bioavailability, rapid metabolism, and fast systematic clearance, which severely limits its clinical applications. In this chapter, we demonstrate the use of catanionic nanovesicles to improve the bioavailability and efficacy of CC for anticancer applications. This technique can be easily adapted for delivery and evaluation of other bioactive compounds.

Norbixin is a natural plant-based pigment that can be used to replace synthetic yellow colorants in foods and other products. It is also being explored as a nutraceutical in functional foods and supplements due to its beneficial biological activities. However, the low-solubility and chemical instability of norbixin currently limit its application in many food products. In this study, the potential of biopolymer nanoparticles assembled from food proteins derived from either animal (sodium caseinate (SC) or whey protein isolate (WPI)) or plant (soy protein isolate (SPI)) sources to encapsulate and protect norbixin was examined. The encapsulation efficiency, loading capacity, size, charge, and interactions of the norbixin-loaded nanoparticles were characterized. All protein nanoparticles could successfully encapsulate and protect norbixin, with loading capacities of 26.8%, 31.5% and 17.0% for SC, WPI and SPI, respectively. Fluorescence, infrared spectroscopy, and X-ray diffraction measurements confirmed that norbixin was trapped within the protein nanoparticles in an amorphous form and that hydrogen bonding occurred between the norbixin and protein matrix. The ability of the norbixin-loaded protein nanoparticles to resist environmental stresses (heat, light exposure, and long-term storage) was ranked according as follows: SPI > SC > WPI. The possibility of using norbixin-loaded SPI nanoparticles as plant-based yellow pigments in cheese production to inhibit the leakage of norbixin into whey was also demonstrated. In summary, this study shows that protein nanoparticles can enhance the water-solubility and stability of norbixin, which may extend the application of this natural pigment in foods.

Microalgae are microorganisms with a singular biochemical composition, including several biologically active compounds with proven pharmacological activities, such as anticancer, antioxidant and anti-inflammatory activities, among others. These properties make microalgae an interesting natural resource to be used as a functional ingredient, as well as in the prevention and treatment of diseases, or cosmetic formulations. Nevertheless, natural bioactives often possess inherent chemical instability and/or poor solubility, which are usually associated with low bioavailability. As such, their industrial potential as a health-promoting substance might be severely compromised. In this context, encapsulation systems are considered as a promising and emerging strategy to overcome these shortcomings due to the presence of a surrounding protective layer. Diverse systems have already been reported in the literature for natural bioactives, where some of them have been successfully applied to microalgae compounds. Therefore, this review focuses on exploring encapsulation systems for microalgae biomass, their extracts, or purified bioactives for food, pharmaceutical, and cosmetic purposes. Moreover, this work also covers the most common encapsulation techniques and types of coating materials used, along with the main findings regarding the beneficial effects of these systems.

The fungal metabolite sphaeropsidin A (SphA) has been recognised for its promising cytotoxicity, particularly towards apoptosis- and multidrug-resistant cancers. Owing to its intriguing activity, the development of SphA as a potential anticancer agent has been pursued. However, this endeavour is compromised since SphA exhibits poor physicochemical stability under physiological conditions. Herein, SphA's instability in biological media was explored utilizing LC-MS. Notably, the degradation tendency was found to be markedly enhanced in the presence of amino acids in the cell medium utilized. Furthermore, the study investigated the presence of degradation adducts, including the identification, isolation and structural elucidation of a major degradation metabolite, (4R)-4,4′,4′-trimethyl-3′-oxo-4-vinyl-4′,5′,6′,7′-tetrahydro-3′H-spiro[cyclohexane-1,1′-isobenzofuran]-2-ene-2-carboxylic acid. Considering the reduced cytotoxic potency of aged SphA solutions, as well as that of the isolated degradation metabolite, the reported antiproliferative activity has been attributed primarily to the parent compound (SphA) and not its degradation species. The fact that SphA continues to exhibit remarkable bioactivity, despite being susceptible to degradation, motivates future research efforts to address the challenges associated with this instability impediment., SCOPUS: ar.j, info:eu-repo/semantics/published

Curcumin, a lipophilic polyphenol contained in the rhizome of Curcuma longa (turmeric), has been used for centuries in traditional Asian medicine, and nowadays it is widely used in food as dietary spice worldwide. It has received considerable attention for its pharmacological activities, which appear to act primarily through anti-inflammatory and antioxidant mechanisms. For this reason, it has been proposed as a tool for the management of many diseases, among which are gastrointestinal and neurological diseases, diabetes, and several types of cancer. However, the pharmacology of curcumin remains to be elucidated; indeed, a discrepancy exists between the well-documented in vitro and in vivo activities of curcumin and its poor bioavailability and chemical instability that should limit any therapeutic effect. Recently, it has been hypothesized that curcumin could exert direct regulative effects primarily in the gastrointestinal tract, where high concentrations of this polyphenol have been detected after oral administration. Consequently, it might be hypothesized that curcumin directly exerts its regulatory effects on the gut microbiota, thus explaining the paradox between its low systemic bioavailability and its wide pharmacological activities. It is well known that the microbiota has several important roles in human physiology, and its composition can be influenced by a multitude of environmental and lifestyle factors. Accordingly, any perturbations in gut microbiome profile or dysbiosis can have a key role in human disease progression. Interestingly, curcumin and its metabolites have been shown to influence the microbiota. It is worth noting that from the interaction between curcumin and microbiota two different phenomena arise: the regulation of intestinal microflora by curcumin and the biotransformation of curcumin by gut microbiota, both of them potentially crucial for curcumin activity. This review summarizes the most recent studies on this topic, highlighting the strong connection between curcumin and gut microbiota, with the final aim of adding new insight into the potential mechanisms by which curcumin exerts its effects.

Summary Plastic pollution is entering the world's oceans at alarming rates and is expected to outweigh fish populations by 2050. This plastic waste originates from land-based applications, like consumer product packaging, and is composed of high-durability polyolefins. These conventional plastics possess desirable properties, including high chemical stability, moisture barrier, and thermoplastic characteristics. Unfortunately, if these materials reach marine environments, they fragment into microplastics that cannot be biologically assimilated. The aim of this review is to investigate commercial polymers that are biodegradable in marine environments but have comparable product stability and moisture barrier properties to polyolefins. Among commercially available biopolymers, thermoplastic starches (TPS) and polyhydroxyalkanoates (PHAs) have been shown to biodegrade in marine environments. Moreover, these biopolymers are thermoplastics and possess similar thermoforming properties to polyolefins. At present, TPS and PHAs have limitations, including chemical instability, limited moisture barrier properties, and high production costs. To replace conventional polymers with PHAs and TPS, these properties must be improved., Graphical Abstract, Industrial Chemistry; Polymer Chemistry; Environmental Science; Materials Science

International audience; Owing to the chemical instability of ZnO nanowires and to their large surface area exhibiting a high density of traps, the use of a protective, passivating shell plays a major role in the performances of many devices. We show that a conformal TiO2 shell can be grown on the ZnO nanowires by a double-step process using atomic layer deposition and postdeposition thermal treatment in air. An in situ analysis of the crystallization process of the amorphous TiOx shell grown by atomic layer deposition is achieved in detail by temperature-dependent Raman scattering and X-ray diffraction measurements, indicating that the crystallization starts around 280 °C in air and that only the anatase phase is formed. It is further revealed from transmission electron microscopy-based experiments that the TiO2 shell with the anatase phase is epitaxially grown on the ZnO nanowires with a range of orientation relationships. Interestingly, the epitaxial TiO2 shell has a beneficial passivating effect and its crystallization resulting from the postdeposition thermal treatment at 350 °C in air leads to the redistribution of the hydrogen-related defects in the center of the ZnO nanowires, as shown by steady-state and time-resolved photoluminescence measurements. These findings demonstrate that the atomic layer deposition technique coupled with a postdeposition thermal treatment is a powerful tool to form ZnO/TiO2 core−shell nanowire heterostructures with high structural and optical quality. They open the way for developing the present double-step processin other nanostructured material systems to master their related surface and interface properties.

Prodrug design has been widely used as a successful approach to achieve selectivity, reduce toxicity, and improve pharmaceutical, pharmacokinetic, and pharmacodynamics features of drugs for some time. The prodrug approach offers enormous applicability as it overcomes several barriers in their applications, including poor aqueous solubility, local irritation after application, inadequate permeability and bioavailability, chemical instability, fast presystemic metabolism, and inappropriate physicochemical characteristics of the drug, among others. Phosphate esters have been used widely to design water-soluble prodrugs as the dianionic phosphate group in their structures is able to increase water-solubility by several orders of magnitude. Prodrugs containing an imine function may also be explored for increasing the water-solubility of compounds. The valproic acid-taurine prodrug exhibited anticonvulsant activity with reduced teratogenicity, demonstrating that, in addition to the increased water-solubility, the adverse effects of the parent drug may also be modulated by using the prodrug approach.

Beer chemical instability remains, at present, the main challenge in maintaining beer quality. Although not fully understood, after decades of research, significant progress has been made in identifying "aging compounds," their origin, and formation pathways. However, as the nature of aging relies on beer manufacturing aspects such as raw materials, process variables, and storage conditions, the chemical profile differs among beers. Current research points to the impact of nonoxidative reactions on beer quality. The effect of Maillard and Maillard intermediates on the final beer quality has become the focus of beer aging research, as prevention of oxidation can only sustain beer quality to some extent. On the other hand, few studies have focused on tracing a profile of whose compound is sensory relevant to specific types of beer. In this matter, the incorporation of "chemometrics," a class of multivariate statistic procedures, has helped brewing scientists achieve specific correlations between the sensory profile and chemical data. The use of chemometrics as exploratory data analysis, discrimination techniques, and multivariate calibration techniques has made the qualitatively and quantitatively translation of sensory perception of aging into manageable chemical and analytical parameters. However, despite their vast potential, these techniques are rarely employed in beer aging studies. This review discusses the chemical and sensorial bases of beer aging. It focuses on how chemometrics can be used to their full potential, with future perspectives and research to be incorporated in the field, enabling a deeper and more specific understanding of the beer aging picture.

The buccal route offers an alternative for drug administration due to its advantages, including the avoidance of the gastrointestinal tract, the hepatic first-pass, enzymatic degradation and chemical instability of certain molecules that would pose a challenge to formulate orally. Moreover, the oral cavity has a lower enzyme content than the rest of the gastrointestinal tract, predictable transit times, easy administration, and provides the opportunity to readily halt drug administration. Additionally, the oral cavity is an organized system with stratified epithelium that allows manufacturing of pharmaceutical forms for drug delivery.

Scaffold-generating and scaffold-morphing tranformations exploiting the chemical instability of the 2-imidazoline moiety under reductive, oxidation, hydrolytic, thermal conditions as well as toward the addition of C- and N-nucleophiles are reviewed.

Carotenoids are well known for their health benefits as provitamin A, and as antioxidants to prevent many chronic diseases. However, carotenoids show poor stability and are highly sensitive to oxidation and degradation during storage, which accordingly limit their applications as health-beneficial components. In addition, the extreme pH environment in stomach can also result in the chemical instability of carotenoids. Hence, it is very important to maintain the stability of carotenoids during exposure to digestion tract environments after oral intake and inhibit the degradation of carotenoids during storage. Protective delivery mechanisms of these compounds are, therefore, required, and utilization of microencapsulation technologies can achieve this. Many encapsulation and delivery systems have been developed to improve the stability of carotenoids, and a correlation between the encapsulation materials and formulations with the stability and degradation velocity of encapsulated carotenoids was also observed. In this chapter, the basic degradation process of carotenoids, the inhibition of the degradation by microencapsulation, and the influence of the encapsulation materials on the degradation of carotenoids are discussed with an attempt to facilitate the design of a proper encapsulation and delivery systems for the specific application of carotenoids.

In this work we report results of step-by-step modeling of the oxidation of free-standing boron monolayers of different types. Results of the calculations demonstrate that the process of the oxidation is always exothermic and lead toward the formation of foam-like boron oxide films with incorporated non-oxidized small boron clusters. Some of these boron-oxide films demonstrate the presence of chemically stable magnetic centers. Evaluation of the physical properties of oxidized boprophene sheets (OBS) demonstrate it possible application in solar energy, as sensors and coating against leakage of hydrogen., 14 pages, 5 figures, accepted in Physica E journal

Pharmaceutical preparation mechanism is a continuous phenomenon. Hundreds of new solid formulations are developed every year. Thus, it is necessary to test and evaluate each solid dosage form for the accurate dispensing and safety of consumers. For this purpose, stability studies and chemical kinetic evaluation pattern must be observed to get the license for the delivery of new drug formulation. For the stability evaluation of solid dosage forms, ICH and WHO guidelines have to be followed, in which a series of tests is involved to prove the validity and rationality of solid dosage forms. Furthermore, the factors or issues related to stability are observed, and chemical kinetics of the solid dosage forms are monitored. The chemical kinetics involved in drug products from their preparation to storage cause chemical instability of drug formulation. This instability may be due to hydrolysis, photolysis, racemization, or other chemical reactions induced during preparation or storage. Thus, for this purpose, stability studies are applied to achieve the stable finished product. Degradation reactions constitute the reason of chemical instability. Thus, it is considered as the most important aspect during stability studies. Degradation processes affect the pre-formulation studies. If this process is not monitored, drugs stored in optimum conditions could be vigorously degraded. Thus, the stability testing is required to prevent any kind of unwanted effects and for the achievement of stable drug throughout its expected shelf life.

Archaeological waterlogged elm wood was treated with methyltrimethoxysilane (MTMS) and (3-mercaptopropyl)trimethoxysilane (MPTES), respectively, and anti-shrink efficiency and sorption properties of the impregnated wood samples were determined. The applied impregnants stabilized wood dimensions efficiently enough, i.e. the obtained anti-shrink efficiency was 81 and 98% for MTMS- and MPTES-treated wood, respectively. Both alkoxysilanes can be considered as potential new consolidants. Hygroscopic properties of untreated and impregnated wood were investigated with the DVS experiments. The application of MTMS and MPTES reduced wood equilibrium moisture content (EMC) and sorption hysteresis e.g. hysteresis relative change was −83.7 and −73.7% for MTMS- and MPTES-treated wood, respectively. The EMC reduction was observed in the whole hygroscopic range and it was primary due to the monolayer capacity decrease to 50 and 30% of the value for untreated wood and observed for adsorption and desorption modes, respectively. The DVS experiments revealed chemical instability of the MTMS-wood system which was neutralized after the cyclic sorption. The possible scenarios of the interaction of both alkoxysilanes with wood structure were discussed.

Silver nanoparticles (AgNPs) are widely used in various fields but their physical and chemical instability have limited their applications. The present work demonstrates a novel approach for the sy...

The ups and downs of a multi-year medicinal chemistry optimisation effort in the quest of identifying inhibitors of human steroid sulfatase as potential topical therapeutics are summarised. The focus lies on dead ends, redirection and mastering of the hurdles rather than detailed structure–activity relationship results of a series. In addition to the usual multi-parameter optimisation towards drug-like properties, unexpected barriers prohibitive for the planned clinical application had to be overcome. While a substrate- and mechanism-based design approach rapidly yielded aryl sulfamates as potent, irreversible enzyme inhibitors, this inhibitor class had to be abandoned due to inherent chemical instability in solution. The rescue of the project was a hit class from a random screening approach, but from there it still took quite some efforts to invent potent reversible inhibitors appropriate for development towards a clinical candidate.

International audience; Infliximab is a monoclonal antibody widely used for the treatment of inflammatory diseases. Over the past few years, many studies have assessed that monoclonal antibodies are prone to aggregation under stress conditions. The aim of this study was to investigate the stability of solutions of an infliximab biosimilar (Inflectra®) at different concentrations (0.4, 2 and 10 mg/mL). These solutions were separately submitted to three temperature conditions that are likely to happen during the drug dispensing system: −20 °C, 5 °C and 25 °C. To perform a complete characterization of infliximab physicochemical and structural stability, a wide range of analytical techniques was employed including: visual inspection, subvisible particles counting (HIAC), dynamic light scattering (DLS), size exclusion chromatography (SEC), cation exchange chromatography (CEX), and analysis of primary, secondary and tertiary structure. When stored at 25 °C, chemical instability was the main limiting factor (highlighted by CEX), while SEC showed only some acceptable variations. After a single freeze-thawing cycle, the amount of subvisible particles was significantly increased. Some variations were also visible in CEX and the hydrodynamic diameter was increased after thawing 10 mg/mL samples. In regard of these results, infliximab (Inflectra®) solutions should not be used after a single freeze-thawing cycle between reconstitution and administration to the patient. The results showed stability at 5 °C of up to 14 days for 10 mg/mL solutions and 90 days for 0.4 and 2 mg/mL solutions, whilst samples stored at 25 °C were stable only 7 days at 10 mg/mL and 30 days when diluted.

O objetivo desta pesquisa é comparar os dois sistemas de produção utilizados atualmente na avicultura de postura: o tradicional e o automatizado. Além das alternativas atuais dadas para disposição do seu principal resíduo sólido, o dejeto das aves. No sistema tradicional as aves são acondicionadas em gaiolas dispostas verticalmente de maneira que seus dejetos se acumulem sob a estrutura. Esse resíduo acumulado é retirado manualmente em torno de 60 dias, com umidade próxima a 28% e estabilizado quimicamente. No geral, o destino desse resíduo é a compostagem, firmas especializadas no tratamento e processamento desse resíduo compram dos produtores de ovos para a produção de adubo. No sistema automatizado o recolhimento do resíduo é contínuo através de uma esteira mecânica instalada sob a base das gaiolas, o resíduo não se acumula na instalação proporcionando um ambiente mais limpo e confortável para as aves. Porém, devido a sua elevada umidade (em torno de 70%) e instabilidade química não é aceito pelas firmas de compostagem, apresenta-se como principal alternativa para sua disposição a biodigestão, uma opção de investimento duplo ganhadora, com vantagens consideráveis do ponto de vista econÿmico e ambiental.

Background Bioactive compounds have gained increasing attention for their health benefits. However, the instability of bioactive compounds during food processing and storage, and low bioavailability or chemical instability when exposed to upper gastrointestinal tract conditions significantly compromised the envisioned benefits, thus limiting their applications. Electrospinning has been recognized as a promising method to encapsulate bioactive compounds since it does not involve any severe conditions of temperature, pressure, or harsh chemicals. Therefore, the nanofibers produced by electrospinning have attracted particular attention in food industry due to the potential as vehicle for the encapsulation and controlled delivery or release of bioactive compounds. Scope and approach Electrospinning is a novel delivery approach for bioactive compounds, it opens a new horizon in food technology with the possibility of commercialization in the near future. This paper presents a brief summary of electrospinning, and its application in encapsulation different types of bioactive compounds by biopolymer matrixes are also highlighted. Further, the existing limitations and scope for future research are discussed. Key findings Recently, considerable studies have been carried out in encapsulation of bioactive compounds using electrospinning. The obtained nanofilm could enhance stability, encapsulation efficiency and oral bioavailability of bioactive compounds, as well as achieve targeted delivery and controlled release, thus facilitating the development of functional foods.

Metal halide perovskites have attracted tremendous interest because of their unique properties. Among these materials, organic–inorganic metal halide perovskite solar cells (PSCs) exhibit a rapid development with the power conversion efficiency (PCE) increased from initially 3.8% to nowadays 25.5%. However, the inherent chemical instability of organic–inorganic metal halide perovskite materials against moisture, heat, and ultraviolet light hinders their commercialization. Therefore, by replacing organic cations with inorganic cations, all-inorganic metal halide (IMH) PSCs are regarded as promising alternatives, and their PCEs have exceeded 20% since the first report in 2015. In this review, we discuss the latest progress of IMH perovskites and their applications in solar cells, which is followed by a summary of existent challenges in the IMH-PSC field and an outlook on future development.

To overcome hydrophobicity and chemical instability of resveratrol (Rev), modified whey protein isolate (WPI) and gelatin (Gel) were used to load Rev. Three treatments including pH-shifting at pH 12 (S), pH-shifting at pH 12 combined with ultrasonication at pH 7 (SU7), and pH-shifting at pH 12 combined with ultrasonication at pH 12 (SU12) were conducted to obtain a series of modified proteins (WPI-S, WPI-SU7, WPI-SU12, Gel-S, Gel-SU7, Gel-SU12). Among them, WPI-SU12 and Gel-SU12 had the highest encapsulation efficiency (EE) and loading capacity (LC) for Rev. The EE and LC were 92.69 ± 0.25% and 17.37 ± 0.067 g/100 g protein in WPI-SU12-Rev nanocomposite, respectively, and 83.85 ± 0.43% and 15.68 ± 0.070 g/100 g protein in Gel-SU12-Rev nanocomposite, respectively. This might be related to the highest surface hydrophobicity of modified proteins in SU12 groups. The particle sizes of all nanocomposites were below 200 nm, while the higher ζ-potential absolute value of WPI-SU12-Rev nanocomposite than that of Gel-SU12-Rev nanocomposite indicated higher stability. Molecular interaction and secondary structure analysis verified that the proteins and Rev bound to each other. Moreover, protein nanocomposites could greatly improve the water solubility and antioxidant capacity of Rev. In summary, the WPI modified by ultrasonication at pH 12 showed the best loading with Rev.

Chemical instability of vitamin A (VA) against acidic pH is the major cause for its low bioavailability. Hence, to improve VA bioavailability, native and modified sodium caseinate were used as delivery system and evaluated for VA bioavailability through in-vivo trials. Effect of VA supplementation through native and modified sodium caseinate-VA complex fortified milks over 4 weeks was monitored in rats. The important VA bioavailability indicators i.e., body weight gain, serum and liver retinol levels, haematological parameters, apparent digestibility coefficient and % retention were investigated. Body weight gain, apparent digestibility coefficient and % retention improved significantly on VA supplementation through milk protein-VAcomplexes. Serum and liver retinol levels were highest in RNaCas followed by NaCas, SNaCas, RSNaCas and free VA fed groups. During the formation of RNaCas and RSNaCas, hydrophobic sites, buried in deep were exposed leading to binding of VA on interior hydrophobic regions of sodium caseinate molecule. Binding of VA with hydrophobic amino acid groups provided protection and stability to VA which may decrease exposure of VA to acidic pH due to its binding on the antioxidative bioactive peptides generated during gastric digestion. Thus, higher stability improved the in-vivo bioavailability of VA.

Compounded oral preparations, made with use of manufactured products as sources of active pharmaceutical ingredients, are characterized by short beyond-use-dates due to their instability. Aim: The aim of this study is to investigate the physical, chemical and microbiological stability of compounded furosemide syrups within a 30 days period. Methods: Batches of 5 mg/ml compounded syrups, using furosemide substance and commercial tablets (two brands) as sources of active pharmaceutical ingredients, were stored in the dark at 5±3 °C and 23±2 °C and examined at days 0, 7, 15, 23, and 30 for changes in physical (pH, formation of colour, gas, odour and changes in viscosity), chemical and microbial stability. A stress test was conducted in order to distinguish signs of chemical instability using a stability-indicating thin-layer chromatographic method. Bacterial inoculation of these samples were examined for microbial stability based on the total aerobic microbial count (TAMC

Despite of their chemical instability and high reactivity, conjugated nitrosoalkenes are useful intermediates in target-oriented organic synthesis. The present review deals with carbon–carbon bond forming reactions involving Michael addition to α-nitrosoalkenes with a particular focus on recent developments in this methodology and its use in total synthesis.

The structure of wondonin marine natural products was renovated to attain new drug-like scaffolds. Wondonins have novel antiangiogenic properties without overt cytotoxicity. However, the chemical instability and synthetic complexity of wondonins have hindered their development as a new type of antiangiogenesis agent. Using a structure-based bioisosterism, the benzodioxole moiety was changed to benzothiazole, and the imidazole moiety was replaced by 1,2,3-triazole. Our efforts resulted in a new scaffold with enhanced antiangiogenic activity and minimized cytotoxicity. One compound with this scaffold effectively inhibited hyaloid vessel formation in diabetic retinopathy mimic zebrafish model. The biological findings together suggested the potential of the scaffold as a lead structure for development of antiangiogenic drugs with novel functions and as a probe to elucidate new biological mechanisms associated with angiogenesis.