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111.
The synthesis of 1,4-dihydro-2-methyl- and 1,4-dihydro-1,2-dimethyl-4-oxo-nicotinic acids was accomplished following a route other than Ochiai's procedure, which yielded the isomer 1,6-dihydro-2-methyl-6-oxo-nicotinic acid ethyl ester, and not the 4-oxo-derivative, as reported. Analytical data confirmed the identity of the two isomer oxo-nicotinic acids. UV-vis and potentiometric preliminary data showed that Al(III) does not form complexes with 1,6-dihydro-2-methyl-6-oxo-nicotinic acid ethyl ester in solution, as expected, but with 1,4-dihydro-2-methyl-4-oxo-nicotinic acid. 相似文献
112.
In this paper, we study the class of graphs defined by excluding the following structures as induced subgraphs: theta, pyramid, 1-wheel, and 3-wheel. We describe the structure of graphs in , and we give a polynomial-time recognition algorithm for this class. We also prove that -free graphs in are 4-colorable. We remark that includes the class of chordal graphs, as well as the class of line graphs of triangle-free graphs. 相似文献
113.
114.
Genotyping technologies need to tackle issues of cost-effectiveness, flexibility, and mutiplexability to meet the ever-increasing demands for clinical diagnostics, addressing the future medical paradigm. Here we report on a facile method for the rapid detection of mutations using electrochemical melting-curve analysis. The concept is based on the use of an immobilised probe hybridised to the mutant region of a ferrocene labelled amplicon. Following hybridisation, the temperature is ramped and the dissociation of the ferrocene labelled DNA from the electrode surface is monitored using differential pulse voltammetry. Using a model system consisting of short probe and target, the proposed approach was demonstrated to clearly discriminate between complementary and mismatch duplexes. The melting temperature of the surface confined DNA duplex was observed to be markedly lower than that obtained in solution, with melting temperatures of 38 and 59 °C, observed, respectively. The approach can be extended to array based melting-curve analysis, allowing the simultaneous detection of multiple mutations, as well as for genosensor design. 相似文献
115.
116.
Luigi Busetto Peter M. Maitlis Valerio Zanotti 《Coordination chemistry reviews》2010,254(5-6):470-486
Vinylalkylidene transition metal complexes have been extensively used as ‘multitalent tools’ in organic synthesis, covering a broad field of applications. The vinylalkylidene ligands can be monodentate; alternatively they can adopt a bridging coordination mode in complexes with two adjacent metal atoms. As for other unsaturated organic ligands which can bond in both mono- and di-nuclear modes, the bridging coordination can give rise to new and different chemical properties from those found when the ligand is bound to a single metal centre. Likewise, the synthetic routes to bridging vinylalkylidene complexes offer a broader range of possibilities compared to those used to make mononuclear vinylalkylidenes. In spite of the fact that bridging vinylalkylidene complexes have been known for about 40 years, their synthetic potential as C3 activated fragments has so far been under-exploited. Comparison with other C3 bridged ligands (allenyls and allyls) indicates that vinylalkylidene ligands are reactive and versatile species. This review article gives an overview of the chemistry of bridging vinylalkylidene complexes to focus attention on their potential as synthetic tools. 相似文献
117.
Elide A. Pastorello Laura Farioli Valerio Pravettoni Joseph Scibilia Amedeo Conti Donatella Fortunato Linda Borgonovo Simona Bonomi Laura Primavesi Barbara Ballmer-Weber 《Analytical and bioanalytical chemistry》2009,395(1):93-102
Italian patients with maize anaphylaxis have been shown to have IgE toward two major maize allergens: an alpha-amylase inhibitor
and a 9-kDa LTP. A complete study on maize food allergens in patients with positive maize double-blind, placebo-controlled
food challenge (DBPCFC) is lacking. The objective was to utilize the three maize protein fractions to identify and characterize
the most relevant IgE-binding proteins recognized by the sera of Italian and Swiss patients with either a positive maize-DBPCFC
or a history of maize-induced anaphylaxis. Osborne’s protein fractions of maize were extracted to obtain water-soluble, total
zein, and total protein fractions. Protein IgE-binding capacity was investigated by SDS-PAGE immunoblotting using the sera
from DBPCFC-positive patients and from patients with maize-induced anaphylaxis. Purified maize LTP was used to inhibit the
IgE immunoblotting of the three protein fractions. IgE immunoblotting demonstrated that the 9-kDa LTP was recognized by all
the Italian patients and by none of the Swiss patients. Other allergens were: 14-kDa α-amylase inhibitor, 30-kDa endochitinases
A and -B, 19 kDa zein-β precursor, and 26 kDa zein-α precursor; a newly described allergen, the globulin-2 precursor, identified in the total protein fraction. It is
noteworthy that maize LTP and endochitinase were cross-reactive with grape LTP and one grape endochitinase. LTP was found
to be the only major allergen in Italian patients with either positive maize challenge or a history of maize-induced anaphylaxis.
We have identified other maize allergens in subjects with maize food allergy, as grape cross-reactive endochitinase, however,
the clinical significance of these proteins needs to be investigated in larger groups of patients with allergy to these food
items. 相似文献
118.
Rosini G Ayoub C Borzatta V Mazzanti A Marotta E Righi P 《Chemical communications (Cambridge, England)》2006,(41):4294-4296
The occurrence of p1,n1 salts can be exploited to sequester racemates; an application to technical mixtures of chrysanthemic acids (ChA) allowed the separation of trans- and cis-ChA and the recovery of the excess enantiomer of trans-ChA. 相似文献
119.
120.
Scalar-tensor theories of gravity can beformulated in the Jordan or in the Einstein frame, whichare conformally related. The issue of which conformalframe is physical is a contentious one; we provide a straightforward example based ongravitational waves in order to clarify theissue. 相似文献