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排序方式: 共有171条查询结果,搜索用时 46 毫秒
31.
Barbara Cardinali Gianluigi Lunardi Enrico Millo Andrea Armirotti Gianluca Damonte Aldo Profumo Stefania Gori Giuseppina Iacono Alessia Levaggi Lucia Del Mastro 《Analytical and bioanalytical chemistry》2014,406(18):4557-4561
Trastuzumab, a humanized monoclonal antibody directed against the epidermal growth factor receptor 2 (HER2), is a milestone in the treatment of HER2-overexpressing breast cancer patients. An enzyme-linked immunosorbent assay (ELISA) for trastuzumab has been developed for routine use in the laboratory to support clinical and pharmacokinetic studies to optimize therapy. The method relies on an antigen peptide linked to a 96-well plate via the streptavidin/biotin system. The peptide sequence mimics the extracellular portion of the HER2 receptor that is recognized by trastuzumab. The calibration range of the assay is 10 to 360 ng/mL per well, corresponding to a trastuzumab serum concentration from 5 to 180 μg/mL with a lower limit of quantification of 10 μg/mL. Validation results demonstrate that trastuzumab can be accurately and precisely quantified in human serum using this assay. The procedure was also tested in sera obtained from breast cancer patients to evaluate trastuzumab serum levels, confirming the applicability of method that could be a valid assay to use in daily laboratory practice. 相似文献
32.
Dr. Tata Gopinath Dr. Veliparambil S. Manu Dr. Daniel K. Weber Prof. Gianluigi Veglia 《Chemphyschem》2022,23(13):e202200127
Solid-state NMR (ssNMR) spectroscopy has emerged as the method of choice to analyze the structural dynamics of fibrillar, membrane-bound, and crystalline proteins that are recalcitrant to other structural techniques. Recently, 1H detection under fast magic angle spinning and multiple acquisition ssNMR techniques have propelled the structural analysis of complex biomacromolecules. However, data acquisition and resonance-specific assignments remain a bottleneck for this technique. Here, we present a comprehensive multi-acquisition experiment (PHRONESIS) that simultaneously generates up to ten 3D 1H-detected ssNMR spectra. PHRONESIS utilizes broadband transfer and selective pulses to drive multiple independent polarization pathways. High selectivity excitation and de-excitation of specific resonances were achieved by high-fidelity selective pulses that were designed using a combination of an evolutionary algorithm and artificial intelligence. We demonstrated the power of this approach with microcrystalline U-13C,15N GB1 protein, reaching 100 % of the resonance assignments using one data set of ten 3D experiments. The strategy outlined in this work opens up new avenues for implementing novel 1H-detected multi-acquisition ssNMR experiments to speed up and expand the application to larger biomolecular systems. 相似文献
33.
Let Q
a,h
be a convex region of the plane whose boundary consists of two semiellipses joined by two (straight) lines parallel to the
major axis of the semiellipses (elliptical stadium). The axes of the semiellipses have length 2 and 2a,a>1, and the lines have length 2h. For and we give a complete proof of the following result: the billiard map in the elliptical stadium Q
a,h
is ergodic, K-mixing and Bernoulli with respect to the natural billiard measure.
Received: 10 May 2002 / Accepted: 24 June 2002 Published online: 10 January 2003
RID="*"
ID="*" Present address: Department of Mathematics, Instituto Superior Técnico, 1049-001 Lisbon, Portugal. E-mail:delmagno@math.ist.utl.pt
Communicated by G. Gallavotti 相似文献
34.
Katalin Csabai Maria Vikmon József Szejtli Enrico Redenti Gianluigi Poli Paolo Ventura 《Journal of inclusion phenomena and macrocyclic chemistry》1998,31(2):169-178
Manidipine (MDP,(±)-2-[-(diphenylmethyl)-1-piperazinyl]ethylmethyl-1,4-dihydro-2,6-dimethyl-4(m-nitrophenyl)-3,5-pyridinedicarboxylate methyl-ester) is a poorlysoluble (<1 g/mL) long acting antihypertensive drug. Salt formingwith citric or tartaric acid results in a 400 to 600 fold solubilityenhancement, respectively, which can be further increased by an order ofmagnitude with cyclodextrins. Dimethyl-CD alone results in a more than8000 fold solubility enhancement. Besides the strongly enhanced solubility1HNMR spectroscopy also proves the inclusion-type interactionbetween Manidipine and cyclodextrins. From the attained 5-8 mg/mL solubilityof the drug in water an improved bioavailability and pharmacokinetics isexpected. 相似文献
35.
Indole 2-carboxamide derivatives 4 underwent palladium-catalyzed intramolecular cyclization reactions to afford beta-carbolinones or pyrazino[1,2-a]indoles according to different reaction pathways. The complete regioselectivity of the reactions was obtained in different reaction conditions. 相似文献
36.
Luppi G Lanci D Trigari V Garavelli M Garelli A Tomasini C 《The Journal of organic chemistry》2003,68(5):1982-1993
The liquid-phase synthesis and the conformational analysis of a small library of fully protected tetramers containing L-pyroglutamic acid (L-pGlu), (4S,5R)-4-methyl-5-carboxybenzyloxazolidin-2-one (L-Oxd), or (4R,5S)-4-methyl-5-carboxybenzyloxazolidin-2-one (D-Oxd) as residue i + 1 are reported to test the tendency of these oligomers to assume a -hairpin conformation. The most promising molecule is Boc-L-Val-D-Oxd-Gly-L-Ala-OBn, which assumes a preferential -turn conformation in CDCl3, as shown by IR and 1H NMR analysis. These findings have been confirmed by DFT calculations, which provide an interpretation for the available experimental data and agree with the reported observations. 相似文献
37.
Mesleh MF Veglia G DeSilva TM Marassi FM Opella SJ 《Journal of the American Chemical Society》2002,124(16):4206-4207
The anisotropy of nuclear spin interactions results in a unique mapping of structure to the resonance frequencies and split tings observed in NMR spectra, however, the determination of molecular structure from experimentally measured spectral parameters is complicated by angular ambiguities resulting from the symmetry properties of dipole-dipole and chemical shift interactions. This issue can be addressed through the periodicity inherent in secondary structure elements, which can be used as an index of topology. Distinctive wheel-like patterns are observed in two-dimensional 1H-15N heteronuclear dipolar/15N chemical shift PISEMA (polarization inversion spin-exchange at the magic angle) spectra of helical membrane proteins in highly aligned lipid bilayer samples. One-dimensional dipolar waves are an extension of two-dimensional PISA (polarity index slant angle) wheels to map protein structure in NMR spectra of both highly and weakly aligned samples. Dipolar waves describe the periodic wavelike variations of the magnitudes of the static heteronuclear dipolar couplings as a function of residue number in the absence of chemical shift effects. Weakly aligned samples of proteins display these same effects, primarily as residual dipolar couplings (RDCs), in solution NMR spectra. The corresponding properties of the RDCs in solution NMR spectra of weakly aligned helices represent a convergence of solid-state and solution NMR approaches to structure determination. 相似文献
38.
Tullio Pilati Gianluigi Casalone 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o178-o180
The title diastereoisomers, methyl 5‐(S)‐[2‐(S)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate and methyl 5‐(S)‐[2‐(R)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate, both C19H23N3O5, have been studied in two crystalline forms. The first form, methyl 5‐(S)‐[2‐(S)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate–methyl 5‐(S)‐[2‐(R)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate (1/1), 2(S),5(S)‐C19H23N3O5·2(R),5(S)‐C19H23N3O5, contains both S,S and S,R isomers, while the second, methyl 5‐(S)‐[2‐(S)‐methoxycarbonyl)‐2,3,4,5‐tetrahydropyrrol‐1‐ylcarbonyl]‐1‐(4‐methylphenyl)‐4,5‐dihydropyrazole‐3‐carboxylate, 2(S),5(S)‐C19H23N3O5, is the pure S,S isomer. The S,S isomers in the two structures show very similar geometries, the maximum difference being about 15° on one torsion angle. The differences between the S,S and S,R isomers, apart from those due to the inversion of one chiral centre, are more remarkable, and are partially due to a possible rotational disorder of the 2‐(methoxycarbonyl)tetrahydropyrrole group. 相似文献
39.
Mingxin Liu Lida Tan Roksana T. Rashid Yunen Cen Shaobo Cheng Gianluigi Botton Zetian Mi Chao-Jun Li 《Chemical science》2020,11(30):7864
Employing photo-energy to drive the desired chemical transformation has been a long pursued subject. The development of homogeneous photoredox catalysts in radical coupling reactions has been truly phenomenal, however, with apparent disadvantages such as the difficulty in separating the catalyst and the frequent requirement of scarce noble metals. We therefore envisioned the use of a hyper-stable III–V photosensitizing semiconductor with a tunable Fermi level and energy band as a readily isolable and recyclable heterogeneous photoredox catalyst for radical coupling reactions. Using the carbonyl coupling reaction as a proof-of-concept, herein, we report a photo-pinacol coupling reaction catalyzed by GaN nanowires under ambient light at room temperature with methanol as a solvent and sacrificial reagent. By simply tuning the dopant, the GaN nanowire shows significantly enhanced electronic properties. The catalyst showed excellent stability, reusability and functional tolerance. All reactions could be accomplished with a single piece of nanowire on Si-wafer.A highly efficient re-usable semiconductor as a radical coupling catalyst in MeOH. 相似文献
40.