Carleman estimates for parabolic equations with interior degeneracy and Neumann boundary conditions

Density of Lipschitz functions in Newtonian spaces based on quasi-Banach function lattices is discussed. Newtonian spaces are first-order Sobolevtype spaces on abstract metric measure spaces defined via (weak) upper gradients. Our main focus lies on metric spaces with a doubling measure that support a Poincaré inequality. Absolute continuity of the function lattice quasi-norm is shown to be crucial for approximability by (locally) Lipschitz functions. The proof of the density result uses, among other facts, the fact that a suitable maximal operator is locally weakly bounded. In particular, various sufficient conditions for such boundedness on quasi-Banach function lattices (and rearrangement-invariant spaces, in particular) are established and applied.     

Recent Advances in Electrochemical Sensors Based on Molecularly Imprinted Polymers and Nanomaterials

This review focuses on the recent achievement during period of 2013–2018 related to the electrochemical sensors based on molecularly imprinted polymers (MIPs) combined with nanomaterials for various kinds of applications. MIPs based electrochemical sensors have found a great interest due to their high stability, short time required for electropolymerization, and high specificity towards the target analyte. The sensitivity is considered as one of the important parameter in electrochemical sensing strategies that should be improved by the combination of highly conductive nanomaterials with selective MIPs. In general, the most employed nanomaterials are magnetic nanoparticles, gold nanoparticles (AuNPs), carbon nanotubes and graphene. This review discusses the main current achievement as well as the current challenges regarding the development of biomimetic sensors in electroanalysis.     

ChemInform Abstract: Crystal Structure of Strontium Dinickel Iron Orthophosphate.

SrNi₂Fe(PO₄)₃ is prepared by drying a stoichiometric HNO₃ solution of the metal nitrates followed by calcination of the residue in air (Pt crucible, 1.     

New Insight into the Chemical Composition,Antimicrobial and Synergistic Effects of the Moroccan Endemic Thymus atlanticus (Ball) Roussine Essential Oil in Combination with Conventional Antibiotics

This study reported the volatile profile, the antimicrobial activity and the synergistic potential of essential oil (EO) from the Moroccan endemic Thymus atlanticus (Ball) Roussine, in combination with the antibiotics ciprofloxacin and fluconazole for the first time, to the best of our knowledge. The EO chemical composition was determined by gas chromatography coupled to mass spectrometry (GC-MS) analysis and the antimicrobial activity assessed by the disc diffusion method against three Gram positive (Bacillus subtilis, Micrococcus luteus, Staphylococcus aureus) and three Gram-negative bacteria (Pseudomonas aeruginosa, Escherichia coli and one clinical isolate, Klebsiella pneumonia). The antifungal activity was evaluated in four pathogenic yeasts (Candida albicans, C. glabrata, C. krusei and C. parapsilosis). The minimum inhibition concentration (MIC) and the synergistic effect with ciprofloxacin and fluconazole were determined by the two-fold dilution technique and checkerboard test, respectively. Twenty-one constituents were identified by GC-MS in the EO, including carvacrol (21.62%) and borneol (21.13%) as the major components. The EO exhibited a significant antimicrobial activity with inhibition zones ranging from 0.7 mm to 22 mm for P. aeruginosa and B. subtilis, respectively, and MIC values varying from 0.56 mg/mL to 4.47 mg/mL. The fractional inhibitory concentration index (FICI) values ranged from 0.25 to 0.50 for bacteria and from 0.25 to 0.28 for yeasts. The maximum synergistic effect was observed for K. pneumonia with a 256-fold gain of antibiotic MIC. Our results have suggested that EO from T. atlanticus may be used alone or in association with antibiotics as a new potential alternative to prevent and control the emergence of resistant microbial strains both in the medical field and in the food industry.     

Valorization of Moroccan Bentonite Deposits: “Purification and Treatment of Margin by the Adsorption Process”

The main objective of this work was to contribute to the reduction in the contamination of phenolic compounds contained in margin by an adsorption process on two types of raw bentonite. The margin used in the studies was collected from a semi-modern oil mill located in the Nador–Morocco region. The results of the physico-chemical analyses showed that the effluents of the oil mills showed that they are highly polluted, particularly in terms of the total suspended solids (TSS), chemical oxygen demand (COD), and iron content of around 154.82 (mg/L), and copper content of 31.72 (mg/L). The mineralogy of bentonites studied by X-ray diffraction (XRD) reveals the existence of two types of montmorillonite; theoretically, the diffraction peak (001) of the montmorillonite appears at 15 Å, with a basal spacing that corresponds to a calcium pole, and the diffraction peak (001) appears at 12Å, with a basal spacing that corresponds to a sodium pole. The specific surface area of the bentonite used is characterized by a large specific surface area, varying between 127.62 m²·g⁻¹ and 693.04 m²·g⁻¹, which is due to the presence of hydrated interleaved cations. This surface is likely to increase in aqueous solution depending on the solid/liquid ratio that modulates the degree of hydration. With a high cation exchange capacity (CEC) (146.54 meq/100 g), samples of margin mixed with raw bentonites at different percentages vary between 5% and 100%. The potential of Moroccan bentonite for the phenol adsorption of 9.17 (g/L) from aqueous solutions was investigated. Adsorption tests have confirmed the effectiveness of these natural minerals in reducing phenolic compounds ranging from 8.72% to 76.23% contained in the margin and the efficiency of heavy metal retention through microelements on raw bentonites. The very encouraging results obtained in this work could aid in the application of adsorption for the treatment of margin.     

The oxidation study of methyl orange dye by hydrogen peroxide using Dawson-type heteropolyanions as catalysts

In this research, the oxidation of an azo dye (methyl-orange) by H₂O₂, in an aqueous solution, using a Dawson-type heteropolyanion (α₂P₂W₁₂Mo₅O₆₁Fe)^7? as catalyst was studied. The effects of different parameters dye oxidation were investigated. The studied parameters were: the initial pH, the initial H₂O₂ concentration, the catalyst mass and the initial dye concentration. The optimal conditions for a maximum discoloration efficiency (100 %) are: pH: 6, [MO]₀ = 2 mg/L, Catalyst (α₂P₂W₁₂Mo₅O₆₁Fe)^7? mass: 1 g, [H₂O₂]₀ =: 0.072 M. The effect of other Dawson-mixed heteropolyanions, such as (αP₂W₁₈O₆₂)^6?, (αP₂W₁₂Mo₆O₆₂)^6? and (α₂P₂W₁₂Mo₅O₆₁X)^n? (X = Ni²⁺,Cr³⁺,Cu²⁺) on the dye oxidation at room temperature was evaluated. The stability of the catalyst after reaction was verified.     

Antioxidant and antimicrobial activities of Withania frutescens

In the present study, we report for the first time the antioxidant and antimicrobial activities of Withania frutescens (L.) Pauquy roots and leaves. Total phenolic content was determined using the Folin-Ciocalteu method and antioxidant activity was evaluated by the DPPH free radical scavenging and reducing power methods. Antimicrobial activity tests were carried out against ten bacterial species involved in nosocomial infections and two opportunistic clinical yeast isolates. The ethyl acetate and n-butanol leaf fractions exhibited the highest DPPH radical scavenging activity with IC50 = 4.53 +/- 0.12 and 8.49 +/- 0.46 microg/mL, respectively. The n-butanol root fraction showed the greatest reducing power comparable with that of quercetin at 0.4 mg/mL. The dichloromethane leaf fraction exhibited the highest antibacterial activity against both Gram-positive and Gram-negative bacteria with MIC values ranging between 50 and 400 microg/mL, depending on the tested bacteria. However, none of the examined extracts exhibited anticandidal activity. The polyphenol and glycowithanolide constituents appeared to be responsible for the antioxidant capacity of W. frutescens, whereas the observed antimicrobial activity may be due to the presence of withanolides.     

New pyrazolic compounds as cytotoxic agents

The evaluation of the in vitro cytotoxic properties of two pyrazole compounds: 1-(4-nitrophényl)-3,5-diméthylpyrazole (1) and 1,1'-di(4-nitrophényl)-5,5'-diisopropyl-3,3'-bipyrazole (2) was investigated against Hep cell line (Human laryngeal carcinoma). These two compounds showed an important cytotoxic activity on the Hep cell line, with IC(50): 8.25 microg mL(-1) for the compound 1; IC(50): 10.20 microg mL(-1) for the compound 2 while the IC(50) for adriamycine used as positive control was 3.62 microg mL(-1).     

Regularity properties of perturbed Hille-Yosida operators and retarded differential equations

In this work we give sufficient conditions on the semigroup (T ₀ (t)) _t\geq0 , generated by the part of a Hille—Yosida operator in the closure of its domain, in order that certain perturbations preserve some regularity properties of (T ₀ (t)) _t\geq0 , like the norm continuity, compactness and differentiability. An application of our abstract results to retarded differential equations is given.     

Novel 1,4-benzothiazine derivatives: synthesis,crystal structure,and anti-bacterial properties

In order to develop relatively small molecules as pharmacologically active molecules, novel 1,4-benzothiazine derivatives with triazole and oxazolidinone were synthesized. In this study, a series of 1,2,3-triazolylmethyl-1,4-benzothiazine derivatives were developed by exploiting a click chemistry reaction using a CuI-catalyzed Huisgen [3 + 2] cycloaddition. Starting from 2-(substituted)-3,4-dihydro-2H-1,4-benzothiazi-3-one, a number of 1,4-benzothiazine derivatives were also synthesized using different alkylating agents to give a 4-(substituted)-2-(substituted)-3,4-dihydro-2H-1,4-benzothiazi-3-one in good yields. The crystal and molecular structure of compound oxazolidin-2-one in basic benzothiazine was established by single-crystal X-ray diffraction. The newly synthesized products were subjected to in vitro biological evaluation. The result indicated that the compounds show convincing antibacterial activities against different microorganisms. All structures of the synthesized compounds were elucidated on the basis of spectral analyses and chemical reactions.