Electrochemical behavior and surface stability of dental zirconia ceramics in acidic environments

Dental zirconia ceramics, widely employed in dentistry for their biocompatibility and mechanical properties, face challenges in long-term viability within the oral cavity. This study focuses on analyzing the electrochemical behavior of a commercial dental zirconia ceramic type in acidic environments. Through extensive electrochemical investigations, including Electrochemical Impedance Spectroscopy (EIS) and cyclic polarization resistance (Cpol), corrosion resistance was assessed. Despite indications of material dissolution, our results demonstrate significant corrosion resistance, as reflected in low corrosion current density (Icorr) values. Notably, the study reveals the development of a protective oxide layer at the ceramic-electrolyte interface, contributing to material stability. XRD analysis confirms the presence of stable crystallographic phases (t-ZrO2) even after exposure to acidic media. Surface characterizations utilizing scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) affirm minimal surface damage and maintained elemental composition. These findings illuminate the intricate electrochemical behavior of dental zirconia ceramics in challenging environments, underscoring their potential for durable dental restorations. This interdisciplinary research bridges dentistry and materials science, providing valuable insights for optimizing material properties and advancing dental materials and restorative techniques.

Isolation of Two Plasticizers, Bis(2-ethylhexyl) Terephthalate and Bis(2-ethylhexyl) Phthalate, from Capparis spinosa L. Leaves

Many plants have been known to be contaminated and accumulate plasticizers from the environment, including water sources, soil, and atmosphere. Plasticizers are used to confer elasticity and flexibility to various fiber and plastic products. Consumption of plasticizers can lead to many adverse effects on human health, including reproductive and developmental toxicity, endocrine disruption, and cancer. Herein, we report for the first time that two plasticizers, bis(2-ethylhexyl) terephthalate (DEHT) and bis(2-ethylhexyl) phthalate (DEHP), have been isolated from the leaves of Capparis spinosa L. (the caper bush), a plant that is widely used in food seasonings and traditional medicine. 297 mg/kg of DEHT and 48 mg/kg of DEHP were isolated from dried and grounded C. spinosa L. leaves using column chromatography and semi-preparative high-performance liquid chromatography. Our study adds to the increase in the detection of plasticizers in our food and medicinal plants and to the alarming concern about their potential adverse effects on human health.

First WHO/UNEP survey of the current concentrations of persistent organic pollutants in human milk in Morocco

The presence of persistent organic pollutants (POPs) in human milk is an indicator of the level of these substances in the environment and enables evaluation of the potential exposure of breastfed children. POPs concentrations in a Moroccan human milk pooled sample (59 donors) were determined for the first time by the WHO reference laboratory to provide a baseline and allow monitoring of the future trends for those persistent organohalogen compounds. Eighty-one different POPs, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dioxins and furans (PCDD/Fs) were identified and quantified by using gas chromatography (GC) with an electron capture detector (ECD) and confirmed by gas chromatography-mass spectrometry (GC/LRMS). The obtained results showed that the sum of DDT (sum of o,p'-DDD, p,p'-DDD, o,p'-DDE, p,p'-DDE, o,p'-DDT, and p,p'-DDT) was 237.9 ng/g, representing 94.0% of all detected OCPs levels, with a dominance of p,p'-DDE, and p,p'-DDT. Cis-heptachlor epoxide, HCB, and HCH were found at much lower levels. PCB indicator level was 60.7 ng/g of lipid, with the dominance of PCB 138, PCB 153, and PCB 180, presenting 98.3% of the total. Among the 25 PBDE congeners quantified, BDE-47, BDE-153, BDE-197, and BDE-207 were the dominant congeners account for 15.4% of the total concentration of PBDE (1.3 pg/g lipid). The lipid-adjusted level of PCDD/Fs and dl-PCBs expressed in Toxic Equivalents (TEQs: 6.65 pg/g) were lower in comparison to those found in the other countries. In summary, detected POPs levels in Moroccan human milk were much lower compared to the other countries, reflecting the effectiveness of the compliance with Stockholm Convention requirements on eliminating or reducing emissions of selected POPs. Continued monitoring is needed for these compounds, for which this is the first data available, provided by the WHO/UNEP survey in Morocco.

Electrochemical Detection of Sulfadiazine by Sensors based on Chemically Modified Carbon Electrodes: A Review

The consumption of medicines (usually pharmaceuticals and chemical health products) has increased in recent decades due to the demand for medicines for various diseases (headache, relapsing fever, dental absence, streptococcal infection, bronchitis, ear and eye infections). Instead, their overuse can lead to serious environmental damage. Sulfadiazine is one of the most often used antimicrobial medications for both human and veterinary therapy, yet its presence in the environment, even in low quantities, offers a potential concern as an emergency pollutant. It is vital to have a monitoring that's quick, selective, sensitive, stable, reversible, reproducible, and easy to use. Electrochemical techniques realizing cyclic voltammetry (CV), differential pulse voltammetry (DPV), and square wave voltammetry (SWV), using a modified electrode based on carbon as a surface modifier are an excellent option that makes control simple and quick owing to their cheap cost and convenience of use, while also safeguarding human health from drug residue buildup. This study discusses different chemically modified carbon-based electrodes such as graphene paste, screen printed electrode, glassy carbon, and boron diamond doped electrodes for SDZ (sulfadiazine) detection in various formulation feeds, pharmaceuticals, milk, and urine samples, the results obtained also show high sensitivity and selectivity with lower detection limits compared to matrix studies, which may explain its use in trace detection. Furthermore, the effectiveness of the sensors is assessed by other parameters including buffer solution, scan rate, and pH. Also, a method for real sample preparation was also discussed in addition to the different methods mentioned.

Phenolic Profile, Antioxidant, Antidiabetic, and Antigout Potential of Stem Extracts of Four Sweet Cherry Cultivars

In order to highlight the activities of bioactive compounds present in the stem of sweet cherries, four different cultivars (Van, Burlat, Napoleon, and Cœur pigeon) were collected in Sefrou city in Morocco and were studied. Several assays were performed for this purpose, such as the quantification of phenolic compounds (TPC, TFC, and CTC) and the evaluation of the antioxidant activity using DPPH, ABTS, and FRAP assays. The phenolic profile of each extract was characterized by UHPLC-DAD/MS analysis. The antidiabetic (α-amylase inhibition) and antigout (xanthine oxidase inhibition) activities were also investigated. The results showed high levels of phenolic compounds, with the values of 340 ± 12.06, 244 ± 10.20, 232 ± 5.07, and 19 ± 3.10 mg gallic acid equivalent/g extract for the cultivars Napoleon, Coeur de pigeon, Van, and Burlat, respectively. According to the same order, the flavonoids showed amounts of 34.31 ± 2.08, 23.75 ± 1.02, 24.37 ± 1.20, and 23.31 ± 0.90 mg (rutin equivalent) RE/g extract. These values were correlated with the results of the antioxidant assays, where the Napoleon cultivar proved to be the most potent using the DPPH (IC₅₀ = 2.51 µg/mL) and ABTS (IC₅₀ = 55.38 µg/mL) assays. The phenolic profile of each extract resulted in the identification of twenty-two compounds belonging to five distinct groups. The major phenolic compounds identified were sakuranetin and dihydrowgonin with their glucosides. Antidiabetic activity assays showed that only stem extracts from Burlat and Napoleon cultivars were able to inhibit the α-amylase enzyme with values of 85.57 ± 1.09% and 68.01 ± 3.52%, respectively. All stem extracts proved their ability to inhibit the xanthine oxidase enzyme which is directly linked to the gout disease, with a high value for Van cultivar (40.63 ± 2.37%). These new findings could provide new opportunities for the valorization of cherry stems for the pharmaceutical application of their active phytochemicals.

Comparative Investigation of Chemical Constituents of Kernels, Leaves, Husk, and Bark of Juglans regia L., Using HPLC-DAD-ESI-MS/MS Analysis and Evaluation of Their Antioxidant, Antidiabetic, and Anti-Inflammatory Activities

Leaves, husk, kernels, and bark methanolic extracts of Juglans regia L. were tested for their in vitro antidiabetic, anti-inflammatory, and antioxidant activities. For these purposes, α-amylase and α-glucosidase were used as the main enzymes to evaluate antidiabetic activities. Moreover, lipoxidase and tyrosinase activities were tested to estimate anti-inflammatory properties. Antioxidant properties of Juglans regia L., extracts were determined using three different assays. Leaves extract has an important radical scavenging activity and a-amylase inhibition. Similarly, husk extracts showed high total phenolic content (306.36 ± 4.74 mg gallic acid equivalent/g dry extract) with an important α-amylase inhibition (IC50 = 75.42 ± 0.99 µg/mL). Kernels exhibit significant tyrosinase (IC50 = 51.38 ± 0.81 µg/mL) correlated with antioxidant activities (p < 0.05). Husk and bark extracts also showed strong anti-lipoxidase activities with IC50 equal to 29.48 ± 0.28 and 28.58 ± 0.35 µg/mL, respectively. HPLC-DAD-ESI-MS/MS analysis highlights the phenolic profile of methanolic extracts of Juglans regia L. plant parts. The identified polyphenols were known for their antioxidant, antidiabetic (dicaffeoyl-quinic acid glycoside in kernels), and anti-inflammatory (3,4-dihydroxybenzoic acid in leaves) activities. Further investigations are needed to determine molecular mechanisms involved in these effects as well as to study the properties of the main identified compounds.

Traditional Knowledge, Phytochemistry, and Biological Properties of Vachellia tortilis

Vachellia tortilis is a medicinal plant of the Fabaceae family, widely distributed in arid and semi-arid regions of North, East and Southern Africa, the Middle East and the Arabian Peninsula. In traditional medicine. It's commonly used to treat certain ailments, including diabetes, asthma, hepatitis and burns. Different scientific search databases were used to obtain data on V. tortilis, notably Google Scholar, Scopus, Wiley Online, Scifinder, Web of Science, ScienceDirect, SpringerLink, and PubMed. The knowledge of V. tortilis was organized based on ethnomedicinal use, phytochemistry, and pharmacological investigations. Phytochemical studies revealed the presence of a variety of phytocompounds, including fatty acids, monosaccharides, flavonoids, chalcones, and alcohols. Essential oils and organic extracts prepared from V. tortilis showed several biological properties, specifically antibacterial, antifungal, antiparasitic, antioxidant, antiproliferative, anti-diabetic, and anti-inflammatory effects. Antimicrobial and antiparasitic activities are due to the disturbance of cellular membranes and ultra-structural changes triggered by V. tortilis phytochemicals. While physiological and molecular processes such as apoptosis induction, preventing cell proliferation, and inflammatory mediators are responsible for the anti-diabetic, anti-cancer, and anti-inflammatory activities. However, further investigations concerning pharmacodynamics and pharmacokinetics should be carried out to validate their clinical applications.

Phytochemistry, Biological Activities, Therapeutic Potential, and Socio-Economic Value of the Caper Bush (Capparis spinosa L.)

Capparis spinosa L., commonly known as the caper bush, is an aromatic plant growing in most of the Mediterranean basin and some parts of Western Asia. C. spinosa L. has been utilized as a medicinal plant for quite a long time in conventional phytomedicine. Polyphenols and numerous bioactive chemicals extracted from C. spinosa L. display various therapeutic properties that have made this plant a target for further research as a health promoter. This review is meant to systematically summarize the traditional uses, the phytochemical composition of C. spinosa L., and the diverse pharmacological activities, as well as the synthetic routes to derivatives of some identified chemical components for the improvement of biological activities and enhancement of pharmacokinetic profiles. This review also addresses the benefits of C. spinosa L. in adapting to climate change and the socio-economic value that C. spinosa L. brings to the rural economies of many countries.

CHEMICAL COMPOSITION AND ANTIBACTERIAL ACTIVITY OF ESSENTIAL OIL OF Lavandula Multifida

This work aims to determine the antioxidant, antibacterial properties and chemical profile of the essential oil (EO) of Lavandula multifida (LM) at the flowering stage collected in northwestern Morocco. So far, information on essential oils of L. multifida remains limited. The extraction yield of the essential oil was 0.46%. The composition was determined by GC-MS-FID. Twenty compounds were identified and the major phytochemicals were carvacrol, ß-bisabolene, and careophyllene oxide (44.3%, 31.9%, and 5.8% respectively). In addition, information on the essential oil of L. multifida collected in the Rabat region is reported for the first time in this study. DPPH and FRAP tests were used to evaluate its antioxidant activity. Antibacterial activities were also studied. Indeed, the essential oil of L. multifida exhibited inhibition effects on the growth of various microorganisms, including S. aureus where the MIC and MBC were equal to 0.5 and 2μg/ml, respectively. Therefore, the use of Lavandula multifida essential oil shows great promise in various fields.

Assessment of Chemical Risks in Moroccan Medical Biology Laboratories in Accordance with the CLP Regulation

Background

Medical laboratory workers are frequently exposed to a wide range of chemicals. This exposure can have adverse effects on their health. Furthermore, a knowledge lack of the chemical risk increases the likelihood of exposure. The chemical risk assessment reduces the risk of exposure to hazardous chemicals and therefore, guarantees health and safety of the workers.

Method

The chemical risk assessment was conducted using a modified INRS method, according to the new CLP Regulation, of 11 unit laboratories in a Moroccan medical laboratory. Observation of each workstation and analysis of safety data sheets are key tools in this study.

Results

A total of 144 substances and reagents that could affect the health of the analytical technicians were identified. Among these products, 17% are concerned by the low priority risk score, with 55% concerned by the average priority risk score and 28% concerned by the high priority risk score. This study also enabled to better identify the chemical agents that have restrictive occupational exposure limit value and controls were conducted to this effect. On the basis of the results obtained, several corrective and preventive measures have been proposed and implemented.

Conclusion

Risk assessment is essential to ensure the health and safety of workers and to meet regulatory requirements. It enables to identify all the risky manipulations and to adopt appropriate preventive measures. However, it is not a one-time activity but it must be continuous in order to master the changes and thus ensure the best safety of all.

Element Content is a Highly Reliable Marker for Niche Vegetable Oils

The content of twelve elements encountered in four different vegetable oils, each coming from a specific geographical location was precisely determined by ICP-AES over three consecutive years (2015–2017). For each oil type, results were remarkably reproducible indicating that element composition is a powerful fingerprint to depict an oil. Our results allow us to suggest that, once the vegetable origin of any niche oil has been certified (using its element content or not), element content determination can sign its geographical origin.

Monitoring of Nitrate and Pesticide Pollution in Mnasra, Morocco Soil and Groundwater

This study evaluates the levels of nitrates and pesticides occurring in groundwater and agricultural soil in the Mnasra, Morocco area, a zone with intensive agricultural activity. A set of 108 water samples and 68 soil samples were collected from ten selected sites in the area during agricultural seasons, from May 2010 to September 2012. The results reveal that 89.7% of water samples exceeded the standard limit of nitrate concentrations for groundwater (50 mg/L). These results can be explained by the prevailing sandy nature of the soil in the area, the frequency of fertilizer usage, and the shallow level of the water table, which favors the leaching of nitrate from field to groundwater. In contrast, the selected pesticide molecules were not detected in the analysed soil and water samples; levels were below the quantification limit in all samples. This situation could be explained by the probable partial or total transformation of the molecules in soil.