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81.
Rosangela Elliani Attilio Naccarato Luana Malacaria Antonio Tagarelli 《Journal of separation science》2020,43(15):3061-3073
In the following work, a new method for the analysis of the phthalate monoesters in human urine was reported. Phthalate monoesters are metabolites generated as a result of phthalate exposure. In compliance with the dictates of Green Analytical Chemistry, a rapid and simple protocol was developed and optimized for the quantification of phthalate monoesters (i.e., monoethyl phthalate, monoisobutyl phthalate, mono‐n‐butyl phthalate, mono‐(2‐ethylhexyl) phthalate, mono‐n‐octyl phthalate, monocyclohexyl phthalate, mono‐isononyl phthalate) in human urine, which entails preceding derivatization with methyl chloroformate combined with the use of commercial solid phase microextraction and the analysis by gas chromatography‐triple quadrupole mass spectrometry. The affinity of the derivatized analytes toward five commercial coatings was evaluated, and in terms of analyte extraction, the best results were reached with the use of the divinylbenzene/carboxen/polydimethylsiloxane fiber. The multivariate approach of experimental design was used to seek for the best working conditions of the derivatization reaction and the solid phase microextraction, thus obtaining the optimum response values. The proposed method was validated according to the guidelines issued by the Food and Drug Administration achieving satisfactory values in terms of linearity, sensitivity, matrix effect, intra‐ and inter‐day accuracy, and precision. 相似文献
82.
Carlo Genovese Luana Pulvirenti Nunzio Cardullo Vera Muccilli Gianna Tempera Daria Nicolosi 《Natural product research》2020,34(12):1653-1662
AbstractIn this work we synthetized the bioinspired benzoxanthene lignans (BXLs) 3, 14–22, and the phenazine derivative 23 as potential antimycotic agents. MICs and MFCs against Candida strains were determined. In a preliminary screening, compounds 3, 15, 20, 21, 22 were substantially inactive. Compounds 14 and 17 showed antifungal activity, being able to inhibit the growth of the majority of Candida strains with MIC values in the range 4.6–19.2?µM (14) and 26.0–104.3?µM (17); for three strains, the MICs were lower than those obtained using the antimycotic drug fluconazole. The three BXLs 18, 19 and 23 showed some MIC values lower than that of fluconazole; 18 was also active against two non-albicans Candida strains resistant to fluconazole. Phenazine 23, although active only against one strain (MIC?=?1.3?µM), was one order of magnitude more potent than fluconazole. All the BXLs were fungicidal. 相似文献
83.
Let (ℋ
t
)
t≥0 be the Ornstein–Uhlenbeck semigroup on ℝ
d
with covariance matrix I and drift matrix λ(R−I), where λ>0 and R is a skew-adjoint matrix, and denote by γ
∞ the invariant measure for (ℋ
t
)
t≥0. Semigroups of this form are the basic building blocks of Ornstein–Uhlenbeck semigroups which are normal on L
2(γ
∞). We prove that if the matrix R generates a one-parameter group of periodic rotations, then the maximal operator ℋ*
f(x)=sup
t≥o
|ℋ
t
f(x)| is of weak type 1 with respect to the invariant measure γ
∞. We also prove that the maximal operator associated to an arbitrary normal Ornstein–Uhlenbeck semigroup is bounded on L
p
(γ
∞) if and only if 1<p≤∞.
相似文献
84.
Tiecco M Testaferri L Santi C Tomassini C Bonini R Marini F Bagnoli L Temperini A 《Organic letters》2004,6(25):4751-4753
[reaction: see text] The first example of a kinetic resolution process promoted by electrophilic selenium reagents is reported. Racemic allylic alcohols react with half equivalents of a selenenylating agent in methanol leading to the regiospecific formation of the corresponding addition products with a very high level of facial selectivity (from 95:5 to 98:2 dr). The unreacted alcohols can be recovered in an optically enriched form (from 90 to 94% ee). 相似文献
85.
86.
Gabriel Lopes Marques Luana Rianne Rocha Maiyara Carolyne Prete Felipe Augusto Gorla Dayana Moscardi dos Santos Mariana Gava Segatelli César Ricardo Teixeira Tarley 《Electroanalysis》2021,33(3):568-578
This paper describes the development of a new electrochemical sensor for 17β-estradiol (E2) determination based on glassy carbon electrode (GCE) modified with molecularly imprinted polymer grafted onto iniferter-multiwall carbon nanotubes surface (MIP-MWCNT) and dihexadecyl-hydrogen-phosphate (DHP). The electrochemical method was based on closed-circuit preconcentration of E2 in 0.1 mol L−1 phosphate buffer (pH 7.0) during 500 s. Upon preconcentration, E2 was determined by differential pulse voltammetry (DPV) exhibiting a limit of detection of 0.01 μmol L−1. The sensor exhibited higher selectivity toward E2 and it was applied for E2 determination in natural water samples, with accuracy attested by HPLC-DAD. 相似文献
87.
Structural Characterisation of Complex Layered Double Hydroxides and TGA‐GC‐MS Study on Thermal Response and Carbonate Contamination in Nitrate‐ and Organic‐Exchanged Hydrotalcites
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Dr. Eleonora Conterosito Dr. Luca Palin Dr. Diego Antonioli Prof. Davide Viterbo Dr. Enrico Mugnaioli Dr. Ute Kolb Dr. Luana Perioli Dr. Marco Milanesio Dr. Valentina Gianotti 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(42):14975-14986
Layered double hydroxides (LDHs) are versatile materials used for intercalating bioactive molecules in the fields of pharmaceuticals, nutraceuticals and cosmetics, with the purpose of protecting them from degradation, enhancing their water solubility to increase bioavailability and improving their pharmacokinetic properties and formulation stability. Moreover, LDHs are used in various technological applications to improve stability and processability. The crystal chemistry of hydrotalcite‐like compounds was investigated by X‐ray powder diffraction (XRPD), automated electron diffraction tomography (ADT) and thermogravimetric analysis (TGA)‐GC‐MS to shed light on the mechanisms involved in ion exchange and absorption of contaminants, mainly carbonate anions. For the first time, ADT allowed a structural model of LDH_NO3 to be obtained from experiment, shedding light on the conformation of nitrate inside LDH and on the loss of crystallinity due to the layer morphology. The ADT analysis of a hybrid LDH sample (LDH_EUS) clearly revealed an increase in defectivity in this material. XRPD demonstrated that the presence of carbonate can influence the intercalation of organic molecules into LDH, since CO3‐contaminated samples tend to adopt d spacings that are approximate multiples of the d spacing of LDH_CO3. TGA‐GC‐MS allowed intercalated and surface‐ adsorbed organic molecules to be distinguished and quantified, the presence and amount of carbonate to be confirmed, especially at low concentrations (<2 wt %), and the different types and strengths of adsorption to be classified with respect to the temperature of elimination. 相似文献
88.
89.
Davide Benedetto Tiz Luana Bagnoli Ornelio Rosati Francesca Marini Luca Sancineto Claudio Santi 《Molecules (Basel, Switzerland)》2022,27(5)
This review describes the recent Food and Drug Administration (FDA)-approved drugs (in the year 2021) containing at least one halogen atom (covalently bound). The structures proposed throughout this work are grouped according to their therapeutical use. Their synthesis is presented as well. The number of halogenated molecules that are reaching the market is regularly preserved, and 14 of the 50 molecules approved by the FDA in the last year contain halogens. This underlines the emergent role of halogens and, in particular, of fluorine and chlorine in the preparation of drugs for the treatment of several diseases such as viral infections, several types of cancer, cardiovascular disease, multiple sclerosis, migraine and inflammatory diseases such as vasculitis. 相似文献
90.
Journal of Sol-Gel Science and Technology - This work describes the preparation and use of a polydimethylsiloxane sponge amino functionalized for the adsorption of copper in water. The sponge was... 相似文献