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41.
Lila L. Gatlin 《International Journal of Theoretical Physics》1980,19(1):25-29
Tolman's paradox forbidding time-reversed information transmission is nonexistent and rests only on our ingrained thought processes involving hidden, unnecessary assumptions. When the assumption of a passive channel is removed, the paradox cannot be derived and information can flow intermittently or nondeterministically from the future over a simple computer with at least one independent decision-making component. 相似文献
42.
Cannac M Pasqualini V Greff S Fernandez C Ferrat L 《Molecules (Basel, Switzerland)》2007,12(8):1614-1622
Fire is a dominant ecological factor in Mediterranean-type ecosystems. Management strategies include prescribed (controlled) burning, which has been used in the management of several species, such as Pinus nigra ssp laricio var. Corsicana, a pine endemic to Corsica of great ecological and economic importance. The effects of prescribed burning on Pinus laricio have been little studied. The first aim of this study was to characterize total and simple phenolic compounds in Pinus laricio. The second aim was to understand: i) the short term (one to three months) and medium term (three years) effects of prescribed burning, and ii) the effects of periodic prescribed burning on the production of phenolic compounds in Pinus laricio. The first result of this study is the presence of total and simple phenolic compounds in the needles of Pinus laricio. 3-Vanillyl propanol is the major compound. After a prescribed burning, the synthesis of total phenolic compounds increases in Pinus laricio for a period of three months. Total phenolic compounds could be used as bioindicators for the short-term response of Pinus laricio needles to prescribed burning. Simple phenolic compounds do not seem to be good indicators of the impact of prescribed burning because prescribed burnings are low in intensity. 相似文献
43.
Blackcurrant is considered as a natural high-value food raw material and possesses a variety of therapeutic properties. The health benefits of blackcurrant have generally been credited to its high anthocyanin content; however, the therapeutic properties of other minor flavonoids constituents have not yet been investigated due the difficulties related to their isolation. Multiple steps of high-performance counter-current chromatography in combination with ESI tandem mass spectrometry (MS(n)) were successfully used for the preparative isolation of flavonols from blackcurrant extract, to study their electrospray ionization mass spectrometry fragmentation behavior. Seven flavonols, namely myricetin-3-O-rutinoside (145.5 mg), myricetin-3-O-hexoside (79.7 mg), myricetin-3-O-(6″-malonyl)-glucoside (17.4 mg), kaempferol-3-O-glucoside (20.5 mg), quercetin-3-O-rutinoside (55.1 mg), quercetin-3-O-hexoside (25.8 mg), and myricetin (129.1 mg) have been successfully isolated and their multistage MS(n) data were used for detailed structure characterization. The results of these experiments demonstrated that high-performance counter-current chromatography along with ESI-MS(n) is a sensitive, selective, and effective technology for isolation and characterization of minor constituents from a complex mixture. 相似文献
44.
Christine Lila Philippe Gloanec Laurence Cadet Yolande Hervé Jean Fournier Fabrice Leborgne 《合成通讯》2013,43(23):4419-4429
To allow the preparation of melagatran on a multigram scale, we have investigated several approaches for the synthesis of the key intermediate 4-aminomethylbenzamidine. The only industrially suitable pathway relies on the preparation of an N-hydroxyimino intermediate. 相似文献
45.
Stéphane Brézillon Valérie Untereiner Lila Lovergne Irene Tadeo Rosa Noguera François-Xavier Maquart Yanusz Wegrowski Ganesh D. Sockalingum 《Analytical and bioanalytical chemistry》2014,406(24):5795-5803
We recently identified vibrational spectroscopic markers characteristic of standard glycosaminoglycan (GAG) molecules. The aims of the present work were to further this investigation to more complex biological systems and to characterize, via their spectral profiles, cell types with different capacities for GAG synthesis. After recording spectral information from individual GAG standards (hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparan sulfate) and GAG-GAG mixtures, GAG-defective mutant Chinese hamster ovary (CHO)-745 cells, wild-type CHO cells, and chondrocytes were analyzed as suspensions by high-throughput infrared spectroscopy and as single isolated cells by infrared imaging. Spectral data were processed and interpreted by exploratory unsupervised chemometric methods based on hierarchical cluster analysis and principal component analysis. Our results showed that the spectral information obtained was discriminant enough to clearly delineate between the different cell types both at the cell suspension and single-cell levels. The abilities of the technique are to perform spectral profiling and to identify single cells with different potentials to synthesize GAGs. Infrared microspectroscopy/imaging could therefore be developed for cell screening purposes and further for identifying GAG molecules in normal tissues during physiological conditions (aging, healing process) and numerous pathological states (arthritis, cancer). Figure
46.
47.
Based on a numerical-analytic scheme of investigation of periodic solutions, we propose a method for the construction of a
matrix-valued Lyapunov function for the linear approximation of a system of equations of locked lasing of two optically coupled
lasers with periodic pumping. 相似文献
48.
49.
We report a new optimal resolution for the statistical stratification problem under proportional sampling allocation among strata. Consider a finite population of N units, a random sample of n units selected from this population and a number L of strata. Thus, we have to define which units belong to each stratum so as to minimize the variance of a total estimator for one desired variable of interest in each stratum, and consequently reduce the overall variance for such quantity. In order to solve this problem, an optimal algorithm based on the concept of minimal path in a graph is proposed and assessed. Computational results using real data from IBGE (Brazilian Central Statistical Office) are provided. 相似文献
50.
Summary The reaction at room temperature of hydrazone derivatives of 2-picolyl, 2-lutidyl and 2-quinaldyl phenyl ketones with CuX2, where X=Cl, Br, NO3 and OAc was investigated by e.s.r., magnetic and spectral methods. A square planar was tentatively assigned for Cu(L)X chelates. The hydrazone derivatives of 2-lutidyl and 2-quinaldyl phenyl ketones reacted with copper(II) halides forming the neutral Cu(L) and Cu(L)2 chelates whereas Cu(OAc)2 gave the [Cu(L)]2 dimer. The adducts formed from the reaction of the copper complexes with pyridine were also investigated. 相似文献