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101.
We establish Lp regularity for the Szegö and Bergman projections associated to a simply connected planar domain in any of the following classes: vanishing chord arc; Lipschitz; Ahlfors-regular; or local graph (for the Szegö projection to be well defined, the local graph curve must be rectifiable). As applications, we obtain Lp regularity for the Riesz transforms, as well as Sobolev space regularity for the non-homogeneous Dirichlet problem associated to any of the domains above and, more generally, to an arbitrary proper simply connected domain in the plane. 相似文献
102.
Dr. Loredana Leone Luca Guarnieri Dr. Jonathan Martinelli Prof. Massimo Sisti Prof. Andrea Penoni Prof. Mauro Botta Prof. Lorenzo Tei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(46):11811-11817
The first binuclear Gd-complex of the 12-membered pyridine-based polyaminocarboxylate macrocyclic ligand PCTA was synthesized by C−C connection of the pyridine units through two different synthetic procedures. A dimeric AAZTA-ligand was also synthesized with the aim to compare the relaxometric results or the two ditopic Gd-complexes. Thus, the 1H relaxometric study on [Gd2PCTA2(H2O)4] and on [Gd2AAZTA2(H2O)4]2− highlighted the remarkable rigidity and compactness of the two binuclear complexes, which results in molar relaxivities (per Gd), at 1.5 T and 298 K of ca. 12–12.6 mM−1 s−1 with an increase of ca. 80 % at 1.5 T and 298 K (+70 % at 310 K) with respect to the corresponding mononuclear complexes. 相似文献
103.
Daniela Hanganu Mihaela Niculae Irina Ielciu Neli-Kinga Olah Melania Munteanu Ramona Burtescu Rzvan tefan Loredana Olar Emoke Pall Sanda Andrei Dan C. Vodnar Daniela Benedec Ilioara Oniga 《Molecules (Basel, Switzerland)》2021,26(11)
Syringa vulgaris L. (common lilac) is one of the most popular ornamental species, but also a promising not comprehensively studied source of bioactive compounds with important therapeutic potential. Our study was designed to characterize the chemical composition and to assess the antioxidant and cytotoxic properties of ethanolic extracts obtained from S. vulgaris L. flowers, leaves, bark, and fruit. The chemical profile of the ethanolic extracts was investigated using chromatographic (HPLC-DAD-ESI+, GC-MS) and spectral (UV-Vis, FT-IR) methods, while the protective effect against free radicals was evaluated in vitro by different chemical assays (DPPH, FRAP, CUPRAC). The cytotoxic activity was tested on two tumoral cell lines, HeLa, B16F10, using the MTT assay. Significant amounts of free or glycosylated chemical components belonging to various therapeutically important structural classes, such as phenyl-propanoids (syringin, acteoside, echinacoside), flavonoids (quercetin, kaempferol derivatives) and secoiridoids (secologanoside, oleuropein, 10-hydroxy oleuropein, demethyloleuropein, syringalactone A, nuzhenide, lingstroside) were obtained for the flowers, leaves and bark extracts, respectively. Furthermore, MTT tests pointed out a significant cytotoxic potential expressed in a non-dose-dependent manner toward the tumoral lines. The performed methods underlined that S. vulgaris extracts, in particular belonging to flowers and leaves, represent valuable sources of compounds with antioxidant and antitumoral potential. 相似文献
104.
Cesare Oliviero Rossi Carmen Cretu Loredana Ricciardi Angela Candreva Massimo La Deda Iolinda Aiello 《Liquid crystals》2017,44(5):880-888
Luminescent complexes with general formula [(C^N)2Ir(N^N)]OCOCH3, where C^N = 2-phenylpyridine (ppy) and N^N = 2,2?-bipyridine (bpy), self-assemble into ordered ‘soft’ viscous mesophases of chromonic type. By changing the ancillary ligand with 1,10-phenanthroline (phen), a new mesomorphic complex was obtained. The self-assembly into ordered liquid crystalline phases of chromonic type in water was investigated by comprehensive rheological and photophysical studies. By changing the ancillary ligand bpy with phen, assembly into smaller, more symetric aggregates is favoured, resulting in lower viscosity and more dynamic mesophase. 相似文献
105.
Viola G Salvador A Cecconet L Basso G Vedaldi D Dall'Acqua F Aloisi GG Amelia M Barbafina A Latterini L Elisei F 《Photochemistry and photobiology》2007,83(6):1415-1427
This article describes the results of a coupled photophysical and photobiological study aimed at understanding the phototoxicity mechanism of the antimalarial drugs amodiaquine (AQ), primaquine (PQ) and chloroquine (CQ). Photophysical experiments were carried out in aqueous solutions by steady-state and time-resolved spectrometric techniques to obtain information on the different decay pathways of the excited states of the drugs and on the transient species formed upon laser irradiation. The results showed that all three drugs possess very low fluorescence quantum yields (10(-2)-10(-4)). Laser flash photolysis experiments proved the occurrence of photoionization processes leading to the formation of a radical cation in all three systems. In the case of AQ the lowest triplet state was also detected. Together with the photophysical properties the photobiological properties of the antimalarial drugs were investigated under UV irradiation, on various biological targets through a series of in vitro assays. Phototoxicity on mouse 3T3 fibroblast and human keratinocyte cell lines NCTC-2544 was detected for PQ and CQ but not for AQ. In particular, PQ- and CQ-induced apoptosis was revealed by the externalization of phosphatidylserine. Furthermore, upon UV irradiation, the drugs caused significant variations of the mitochondrial potential (Deltapsi(mt)) measured by flow cytometry. The photodamages produced by the drugs were also evaluated on proteins, lipids and DNA. The combined approaches were useful in understanding the mechanism of phototoxicity induced by these antimalarial drugs. 相似文献
106.
Aloisi GG Amelia M Barbafina A Latterini L Elisei F dall'Acqua F Vedaldi D Faccio A Viola G 《Photochemistry and photobiology》2007,83(3):664-674
The interactions and the photosensitizing activity of three antimalarial drugs quinine (Q), mefloquine (MQ) and quinacrine (QC) toward DNA was studied. Evidences obtained by absorption and emission spectroscopy and by linear dichroism measurements indicate that these derivatives bind the macromolecule with a high affinity (binding constants Ka approximately 10(5) M(-1)). The absorption characteristics of the drugs changed markedly by addition of DNA and their fluorescence was quenched with rate constants higher than that of diffusion. The geometry of binding involves predominantly the intercalation into the double helix. The DNA photocleavage properties of antimalarials was investigated using plasmid DNA as a model, at different [drug]/ [DNA] ratios. The results indicate that mainly MQ and Q are able to induce significant photodamage to DNA. In particular the marked effect of the former drug is evidenced after treatment of photosensitized DNA by two base excision repair enzymes, formamydo-pyrimidine glycosilase (Fpg) and Endonuclease III (Endo III). From a mechanistic point of view, experiments carried out in different experimental conditions indicate that these drugs photoinduce DNA damage through singlet oxygen and/or radical cation production. These findings are further supported by the determination of two photoproducts of 2'-deoxyguanosine, which are diagnostic for Type I and Type II pathways, namely 2,2-diamino(2-deoxy-beta-D-erythro-pentofuranosyl)-4-amino-5(2H)-oxazolone and (R,S)4-hydroxy-8-oxo-4,8-dihydro-2'-deoxyguanosine (4-OH-8-oxo-dGuo). Laser flash photolysis experiments carried out in the presence of DNA indicates that the excitation produces mainly the triplet state for Q and the triplet and radical cation for QC. Moreover the singlet and triplet states and radical cations of the drugs are quenched by 2'-deoxyguanosine monophosphate. The absorbances of these transients decrease with increasing DNA concentration. 相似文献
107.
De Bartolo L Morelli S Rende M Campana C Salerno S Quintiero N Drioli E 《Macromolecular bioscience》2007,7(5):671-680
The viability and liver specific functions of human hepatocytes in a multibore fiber bioreactor are reported. Human hepatocytes were cultured in the intraluminal compartment of the bioreactor. Human hepatocytes on the membranes maintained their round shape and showed focal adhesions as sites of interaction with the membrane surface. Cells in the bioreactor expressed liver specific functions, including synthetic and detoxification activity up to 14 d of culture. The results demonstrate that human hepatocytes cultured in the multibore fiber bioreactor are able to sustain the same in vivo liver functions in vitro. 相似文献
108.
Di Donna L De Nino A Maiuolo L Mazzotti F Napoli A Salerno R Sindona G 《Journal of mass spectrometry : JMS》2007,42(8):1057-1061
The investigation of the gas-phase chemistry of azo compounds by mass spectrometry dates back to the introduction of this peculiar research field into the armory of physical organic chemistry tools. The mechanism of the fragmentation of the azo double bond from the protonated precursor is discussed with reference to the behavior of deuterium-labeled reference compounds. The investigated molecules belong to the sudan family and the results can be used for the detection of these potential carcinogenic compounds in different matrices by means of the isotope dilution method. 相似文献
109.
Kadarkarai Murugan Anitha Jaganathan Rajapandian Rajaganesh Udaiyan Suresh Jagan Madhavan Sengottayan Senthil-Nathan Aruliah Rajasekar Akon Higuchi Suresh S. Kumar Abdullah A. Alarfaj Marcello Nicoletti Riccardo Petrelli Loredana Cappellacci Filippo Maggi Giovanni Benelli 《Journal of Cluster Science》2018,29(1):27-39
Green fabricated nanoparticles often need to be encapsulated and stabilized, to ensure uniform dispersion in the aquatic environment and relevant larvicidal activity over time. However, recent research showed that nanoencapsulation processes led to a reduction of nanoparticle larvicidal efficacy. We used an extract of Argemone mexicana to reduce TiO2 nanoparticles, which were then capped with PSS/PAH (poly(styrene sulfonate)/poly(allylamine hydrochloride)). The toxic and repellent potential of the nanoparticles were compared to elucidate their potential effects against the Zika virus vector Aedes aegypti. Nanoparticles were characterized by biophysical methods including UV–Vis, EDX and FTIR spectroscopy, SEM, TEM, XRD and DLS analyses. In larvicidal and pupicidal experiments, TiO2 nanoparticles achieved LC90 values from 41.648 (larva I), to 71.74 ppm (pupa). Nanoencapsulated TiO2 achieved LC90 values from 39.16 (I), to 69.12 ppm (pupa). In adulticidal experiments, LC90 of TiO2 nanoparticles on Ae. aegypti was 10.31 ppm, while LC90 of nanoencapsulated TiO2 was 9.54 ppm. At 10 ppm, the repellency towards Ae. aegypti was 80.43% for TiO2 nanoparticles, and 88.04% for nanoencapsulated TiO2. This research firstly highlighted the promising potential of PSS/PAH encapsulation, leading to the production of highly effective titania nanostructures, if compared to titania nanoparticles synthesized with eco-friendly routes without further stabilization. 相似文献
110.
Loredana Incarnato Domenico Acierno Pietro Russo Mario Malinconico Paola Laurienzo 《Journal of Polymer Science.Polymer Physics》1999,37(17):2445-2455
In this work, the relationships between composition and properties of Ny6/EVOH system were examined by means of several techniques and the results were interpreted in terms of level of compatibility. Blends of different ratio of Ny6 and EVOH have been processed in a laboratory‐based film blowing extrusion apparatus. Rheological measurements, FTIR and morphological analysis, and thermal and mechanical properties were carried out. Peculiar rheological, thermal, and mechanical behaviors were observed for the blend containing 25% by weight of EVOH. At this composition, FTIR analysis has pointed out that a minimum in molecular motion is achieved as a consequence of a maximum interaction of the polar groups (amide groups of Ny6 and hydroxyl groups of EVOH) involved. Moreover, gas permeability measurements on the blown films have been performed at T = 30°C. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 2445–2455, 1999 相似文献