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排序方式: 共有163条查询结果,搜索用时 31 毫秒
111.
112.
Herman K Szabó L Leopold LF Chiş V Leopold N 《Analytical and bioanalytical chemistry》2011,400(3):815-820
A new, simple, and effective approach for multianalyte sequential surface-enhanced Raman scattering (SERS) detection in a
flow cell is reported. The silver substrate was prepared in situ by laser-induced photochemical synthesis. By focusing the
laser on the 320 μm inner diameter glass capillary at 0.5 ml/min continuous flow of 1 mM silver nitrate and 10 mM sodium citrate
mixture, a SERS active silver spot on the inner wall of the glass capillary was prepared in a few seconds. The test analytes,
dacarbazine, 4-(2-pyridylazo)resorcinol (PAR) complex with Cu(II), and amoxicillin, were sequentially injected into the flow
cell. Each analyte was adsorbed to the silver surface, enabling the recording of high intensity SERS spectra even at 2 s integration
times, followed by desorption from the silver surface and being washed away from the capillary. Before and after each analyte
passed the detection window, citrate background spectra were recorded, and thus, no “memory effects” perturbed the SERS detection.
A good reproducibility of the SERS spectra obtained under flow conditions was observed. The laser-induced photochemically
synthesized silver substrate enables high Raman enhancement, is characterized by fast preparation with a high success rate,
and represents a valuable alternative for silver colloids as SERS substrate in flow approaches. 相似文献
113.
Giuseppe Romeo Valeria Ciaffaglione Emanuele Amata Maria Dichiara Loredana Calabrese Luca Vanella Valeria Sorrenti Salvo Grosso Agata Grazia DAmico Velia DAgata Sebastiano Intagliata Loredana Salerno 《Molecules (Basel, Switzerland)》2021,26(13)
Cancer is a multifactorial disease that may be tackled by targeting different signaling pathways. Heme oxygenase-1 (HO-1) and sigma receptors (σRs) are both overexpressed in different human cancers, including prostate and brain, contributing to the cancer spreading. In the present study, we investigated whether HO-1 inhibitors and σR ligands, as well a combination of the two, may influence DU145 human prostate and U87MG human glioblastoma cancer cells proliferation. In addition, we synthesized, characterized, and tested a small series of novel hybrid compounds (HO-1/σRs) 1–4 containing the chemical features needed for HO-1 inhibition and σR modulation. Herein, we report for the first time that targeting simultaneously HO-1 and σR proteins may be a good strategy to achieve increased antiproliferative activity against DU145 and U87MG cells, with respect to the mono administration of the parent compounds. The obtained outcomes provide an initial proof of concept useful to further optimize the structure of HO-1/σRs hybrids to develop novel potential anticancer agents. 相似文献
114.
Rachele Pucciariello Loredana Tammaro Vincenzo Villani Vittoria Vittoria 《Journal of Polymer Science.Polymer Physics》2007,45(8):945-954
Novel composites based on poly(ε‐caprolactone) (PCL) and an organically modified layer double hydroxide (LDH) obtained using the melt‐extrusion technique have been characterized through structural, thermal, and mechanical analyses. Although exfoliation has not been achieved and despite the very low content of filler (from 1 to 3% by weight), significant enhancements are obtained in the physical and mechanical properties of the composites with respect to neat PCL. As a consequence, LDHs can substitute other nanofillers, in particular, cationic clays for polymeric matrices. They can be modified by a large number of organic anions, generally more numerous than the cationic ones, and can be mixed in very simple ways with polymers. This makes such nanofillers suitable to obtain new hybrid materials for a series of applications, from active food packaging to intelligent materials for biomedical device, for example, controlled drug release. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 945–954, 2007 相似文献
115.
Castronovo M Bano F Raugei S Scaini D Dell'Angela M Hudej R Casalis L Scoles G 《Journal of the American Chemical Society》2007,129(9):2636-2641
The penetration resistance of a prototypical model-membrane system (HS-(CH2)11-OH self-assembled monolayer (SAM) on Au(111)) to the tip of an atomic force microscope (AFM) is investigated in the presence of different solvents. The compressibility (i.e., height vs tip load) of the HS-(CH2)11-OH SAM is studied differentially, with respect to a reference structure. The reference consists of hydrophobic alkylthiol molecules (HS-(CH2)17-CH3) embedded as nanosized patches into the hydrophilic SAM by nanografting, an AFM-assisted nanolithography technique. We find that the penetration resistance of the hydrophilic SAM depends on the nature of the solvent and is much higher in the presence of water than in 2-butanol. In contrast, no solvent-dependent effect is observed in the case of hydrophobic SAMs. We argue that the mechanical resistance of the hydroxyl-terminated SAM is a consequence of the structural order of the solvent-SAM interface, as suggested by our molecular dynamics simulations. The simulations show that in the presence of 2-butanol the polar head groups of the HS-(CH2)11-OH SAM, which bind only weakly to the solvent molecules, try to bind to each other, disrupting the local order at the interface. On the contrary, in the presence of water the polar head groups bind preferentially to the solvent that, in turn, mediates the release of the surface strain, leading to a more ordered interface. We suggest that the mechanical stabilization effect induced by water may be responsible for the stability of even more complex, real membrane systems. 相似文献
116.
Stefano Banfi Enrico Caruso Loredana Buccafurni Raffaella Ravizza Marzia Gariboldi Elena Monti 《Journal of organometallic chemistry》2007,692(6):1269-1276
A panel of eight Zn-phthalocyanines (Zn-Pcs) (1)-(8), differently substituted on the benzo units, was synthesized either by direct cyclic-tetramerization of substituted phthalonitriles (compounds 1 and 2), or leading from the easily available tetrasulphonyl phthalocyanine to yield the sulfonamido derivatives 3 and 4, or else via the chloromethylation of precedent Zn-Pc followed by reaction with nucleophiles affording the dicationic Zn-Pcs (5) and (6) or the neutral Zn-Pcs (7) and (8). The phototoxicity of these new compounds was evaluated in vitro on human colon adenocarcinoma cell line (HCT116), and their effect compared with those induced by porfimer sodium. The results are reported as IC50 values, following exposure of the cells to different Zn-Pcs concentration and irradiation with a 500 W tungsten/halogen white lamp. The cationic Zn-Pc (5) and (6) together with the Zn-Pc (7), featuring 12 methoxy groups, were found good or fairly good photosensitizers while the more lipophilic Zn-Pcs (1)-(4) and (8) were found devoid of activity. 相似文献
117.
Loredana Elena Niţă Aurica P. Chiriac Maria Bercea Iordana Neamţu 《Rheologica Acta》2007,46(5):595-600
The effects of heating rate and shear stress on the sol–gel transition for a polyacrylamide gel during in situ preparation
were investigated by dynamic rheology. The gelation evolution was also studied through monitoring of the static gelation process
by means of temperature, pH, and conductivity variation. The gels were prepared by polymerization of acrylamide crosslinked
with N,N′-methylenebisacrylamide using a redox initiation based on potassium persulfate/ascorbic acid. In situ gelation process was
studied using oscillatory deformation tests at constant frequency of 0.1 Hz for different heating rate (from 0.5 to 5 °C/min)
and shear stress (in the range of 0.1 to 10 Pa).
The paper was presented at the third annual rheology conference, AERC 2006, Crete, Greece, 27–29 April 2006. 相似文献
118.
119.
Dr. Loredana Leone Dr. Alessandro Pezzella Prof. Orlando Crescenzi Prof. Alessandra Napolitano Prof. Vincenzo Barone Prof. Marco d’Ischia 《ChemistryOpen》2015,4(3):370-377
Current molecular cryptography (MoCryp) systems are almost exclusively based on DNA chemistry and reports of cryptography technologies based on other less complex chemical systems are lacking. We describe herein, as proof of concept, the prototype of the first asymmetric MoCryp system, based on an 8-compound set of a novel bioinspired class of cyanine-type dyes called trichocyanines. These novel acidichromic cyanine-type dyes inspired by red hair pigments were synthesized and characterized with the aid of density functional theory (DFT) calculations. Trichocyanines consist of a modular scaffold easily accessible via an expedient condensation of 3-phenyl- or 3-methyl-2H-1,4-benzothiazines with N-dimethyl- or o-methoxyhydroxy-substituted benzaldehyde or cinnamaldehyde derivatives. The eight representative members synthesized herein can be classified as belonging to two three-state systems tunable through four different control points. This versatile dye platform can generate an expandable palette of colors and appears to be specifically suited to implement an unprecedented single-use asymmetric molecular cryptography system. With this system, we intend to pioneer the translation of digital public-key cryptography into a chemical-coding one-time-pad-like system. 相似文献
120.