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21.
L. P. Battaglia A. Bonamartini Corradi G. Pelosi L. Menabue M. Saladini M. Sola G. Marcotrigiano P. Morini 《Journal of chemical crystallography》1991,21(3):313-319
In this paper are reported structural and spectroscopic properties of (N-benzenesulphonylglycinato) triaquacopper (II) (complex I) and dipotassium bis (N-benzenesulphonylglycinato) cuprate (II) (complex II). The crystals of (I) are monoclinic, space groupP21/c,Z=4, with=12.736(4),b=10.292(3),c=10.402(3) Å,=109.41(2)° while those of complex (II) are orthorhombic, space groupPbca, witha=23.333(8),b=10.508(4),c=16.989(5) Å. In both complexes the aminoacid molecules act as bidentatevia carboxylic oxygen and the amide nitrogen atom; in (I) three water molecules complete the coordination to tetragonal pyramidal, while in (II) coordination is square planar, tetrahedrally distorted involving two ligand molecules. The structure (I) was refined to a finalR index of 0.0596 and (II) toR=0.0466. 相似文献
22.
R. de Leone 《Journal of Optimization Theory and Applications》1991,69(2):235-249
A unified treatment is given for partially and totally asynchronous parallel successive overrelaxation (SOR) algorithms for the linear complementarity problem. Convergence conditions are established and compared to previous results. Convergence of the partially asynchronous method for the symmetric linear complementarity problem can be guaranteed if the relaxation factor is sufficiently small. Unlike previous results, this relaxation factor interval does not depend explicitly on problem size.This material is based on research supported by the Air Force Office of Scientific Research Grant No. AFOSR-89-0410.The author wishes to thank the referee for pointing out how to improve the bound (12). The same technique can be used to reduce the factorn in Ref. 5, p. 553, to
. 相似文献
23.
24.
Dr. Giuseppe Ferrauto Dr. Daniela Delli Castelli Dr. Loredana Leone Prof. Mauro Botta Prof. Silvio Aime Dr. Zsolt Baranyai Prof. Lorenzo Tei 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(16):4184-4193
The new ligand HPDO3MA [(R,R,R,R)-10-(2-hydroxypropyl)-α,α′,α′′-trimethyl-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid] was designed to combine and optimize the chemical properties of the macrocyclic ligands HPDO3A and DOTMA. The presence of the methyl groups on the acetic pendant arms of HPDO3A is expected to rigidify the structure of the ligand and favor an increase of the kinetic inertness of the Ln complexes. 1H NMR spectra of Eu(HPDO3MA) displayed the presence of two pairs of diastereoisomers: SAP (square antiprismatic) and TSAP (twisted square antiprismatic) isomers (56 and 44 %, respectively). In addition, 1H and 17O relaxometric NMR studies of Gd(HPDO3MA) showed approximately a 10 % increase in relaxivity and a faster water exchange rate with respect to Gd(HPDO3A). Moreover, a detailed chemical exchange saturation transfer (CEST) characterization of Yb(HPDO3MA) displayed a sensitivity about two times larger than that of Yb(HPDO3A) both in phantom and in cell labeling experiments. Finally, the kinetic inertness of Yb(HPDO3MA) was measured to be twice as high as that of Yb(HPDO3A), with a dissociation half-life at physiological pH of about 2500 years. 相似文献
25.
Giuseppe Leone Antonella Caterina Boccia Giovanni Ricci Antonino Giarrusso Lido Porri 《Journal of polymer science. Part A, Polymer chemistry》2013,51(15):3227-3232
(E)‐1,3‐Pentadiene (EP) and (E)‐2‐methyl‐1,3‐pentadiene (2MP) were polymerized to cis‐1,4 polymers with homogeneous and heterogeneous neodymium catalysts to examine the influence of the physical state of the catalyst on the polymerization stereoselectivity. Data on the polymerization of (E)‐1,3‐hexadiene (EH) are also reported. EP and EH gave cis‐1,4 isotactic polymers both with the homogeneous and with the heterogeneous system, whereas 2MP gave an isotactic cis‐1,4 polymer with the heterogeneous catalyst and a syndiotactic cis‐1,4 polymer, never reported earlier, with the homogeneous one. For comparison, the results obtained with the soluble CpTiCl3‐based catalyst (Cp = cyclopentadienyl), which gives cis‐1,4 isotactic poly(2MP), are examined. A tentative interpretation is given for the mechanism of the formation of the stereoregular polymers obtained and a complete NMR characterization of the cis‐1,4‐syndiotactic poly(2MP) is reported. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3227–3232 相似文献
26.
Andrea Mosseri Dr. Maria Sancho-Albero Dr. Marilisa Leone Donatella Nava Dr. Francesco Secundo Prof. Daniela Maggioni Prof. Luisa De Cola Prof. Alessandra Romanelli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(37):e202200693
Self-assembly of biomolecules such as peptides, nucleic acids or their analogues affords supramolecular objects, exhibiting structures and physical properties dependent on the amino-acid or nucleobase composition. Conjugation of the peptide diphenylalanine (FF) to peptide nucleic acids triggers formation of self-assembled structures, mainly stabilized by interactions between FF. In this work we report formation of homogeneous chiral fibers upon self-assembly of the hybrid composed of the tetraphenylalanine peptide (4F) conjugated to the PNA dimer adenine-thymine (at). In this case nucleobases seem to play a key role in determining the morphology and chirality of the fibers. When the PNA “at” is replaced by guanine-cytosine dimer “gc”, disordered structures are observed. Spectroscopic characterization of the self-assembled hybrids, along with AFM and SEM studies is reported. Finally, a structural model consistent with the experimental evidence has also been obtained, showing how the building blocks of 4Fat arrange to give helical fibers. 相似文献
27.
Larisa Ryskalin Stefano Puglisi-Allegra Gloria Lazzeri Francesca Biagioni Carla L. Busceti Linda Balestrini Andrea Fornasiero Stefano Leone Elena Pompili Michela Ferrucci Francesco Fornai 《Molecules (Basel, Switzerland)》2021,26(9)
Curcumin (CUR), a natural polyphenol extracted from rhizome of the Curcuma longa L, has received great attention for its multiple potential health benefits as well as disease prevention. For instance, CUR protects against toxic agents acting on the human body, including the nervous system. In detail, CUR possesses, among others, strong effects as an autophagy activator. The present study indicates that CUR counteracts methamphetamine (METH) toxicity. Such a drug of abuse is toxic by disturbing the autophagy machinery. We profited from an unbiased, low variable cell context by using rat pheochromocytoma PC12 cell line. In such a system, a strong protection was exerted by CUR against METH toxicity. This was associated with increased autophagy flux, merging of autophagosomes with lysosomes and replenishment of autophagy vacuoles with LC3, which instead is moved out from the vacuoles by METH. This is expected to enable the autophagy machinery. In fact, while in METH-treated cells the autophagy substrates α-synuclein accumulates in the cytosol, CUR speeds up α-synuclein clearance. Under the effects of CUR LC3 penetrate in autophagy vacuoles to commit them to cell clearance and promotes the autophagy flux. The present data provide evidence that CUR counteracts the neurotoxic effects induced by METH by promoting autophagy. 相似文献
28.
Combined Experimental and Multivariate Model Approaches for Glycoalkaloid Quantification in Tomatoes
Gabriella Tamasi Alessio Pardini Riccardo Croce Marco Consumi Gemma Leone Claudia Bonechi Claudio Rossi Agnese Magnani 《Molecules (Basel, Switzerland)》2021,26(11)
The intake of tomato glycoalkaloids can exert beneficial effects on human health. For this reason, methods for a rapid quantification of these compounds are required. Most of the methods for α-tomatine and dehydrotomatine quantification are based on chromatographic techniques. However, these techniques require complex and time-consuming sample pre-treatments. In this work, HPLC-ESI-QqQ-MS/MS was used as reference method. Subsequently, multiple linear regression (MLR) and partial least squares regression (PLSR) were employed to create two calibration models for the prediction of the tomatine content from thermogravimetric (TGA) and attenuated total reflectance (ATR) infrared spectroscopy (IR) analyses. These two fast techniques were proven to be suitable and effective in alkaloid quantification (R2 = 0.998 and 0.840, respectively), achieving low errors (0.11 and 0.27%, respectively) with the reference technique. 相似文献
29.
A novel Fourier transform spectral interferometric (FTSI) multiplex coherent anti-Stokes Raman scattering (CARS) technique is developed to extract the vibrational spectrum equivalent to the spontaneous Raman scattering. The conventional FTSI method is modified to use the internal nonresonant CARS signal as a local oscillator to perform spectral interferometry. Utilizing the causality of the coherent vibration (i.e., there should be no signal before the laser excitation), this new FTSI method recovers the entire complex vibrational spectral parameters. We demonstrate this technique with a previously reported single-pulse multiplex CARS method that uses a single phase-controlled broadband ultrafast laser pulse. 相似文献
30.
Manuela Zanetti Devid Maniglio Cristian Fasoli Marco Pola Elisa Borga Claudio Corradi Mauro Dalla Serra Salvatore Iannotta Antonella Motta Tullio Toccoli 《Electroanalysis》2014,26(8):1653-1659
We report the fabrication of a microfluidic apparatus and the realization of a sensors based on PEDOT : PSS, a biocompatible semiconductor polymer used in substitution of standard electrodes for electrophysiological studies and for detection of nanopores in membrane. This gives the possibility to study the mechanisms of ions balance and molecular transport though cell membranes. In particular the apparatus is based on two chambers connected through an aperture in a PTFE sheet where lipid bilayer are formed using Montal‐Mueller method, and the pore‐forming proteins activity is detected by polymeric electrodes. This methodology could be applied to examine different membrane proteins for the purpose of biosensing, drug screening and nanopore technologies. 相似文献