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161.
Rohini M. Godbole Agnes Grau Rohit Hegde Giulia Pancheri Yogi Srivastava 《Pramana》2006,66(4):657-668
In this note, we summarize and compare various model predictions forpp total cross-section σ
tot
pp
, giving an estimate of the range of predictions for the total cross-section, σ
tot
pp
expected at the LHC. We concentrate on the results for σ
tot
pp
obtained in a particular QCD based model of the energy dependence of the total cross-section, including the effect of soft
gluon radiation. We obtain the range of predictions in this model by exploring the allowed range of model parameters. We further
give a handy parametrisation of these results which incidentally spans the range of various other available predictions at
the LHC as well 相似文献
162.
Benny Febriansyah Dr. Tetiana Borzda Dr. Daniele Cortecchia Dr. Stefanie Neutzner Dr. Giulia Folpini Dr. Teck Ming Koh Dr. Yongxin Li Prof. Nripan Mathews Prof. Annamaria Petrozza Prof. Jason England 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(27):10883-10888
Published studies of layered (2D) (100)-oriented hybrid lead-bromide perovskites evidence a correlation between increased inter-octahedral (Pb-Br-Pb) distortions and the appearance of broadband white light emission. However, the impact of distortions within their constituent [PbBr6]4− octahedra has yet to be assessed. Herein, we report two new (100)-oriented 2D Pb-Br perovskites, whose structures display unusually high intra-octahedral distortions, whilst retaining minimal inter-octahedral distortions. Using a combination of temperature-dependent, power-dependent and time-resolved photoluminescence spectroscopic measurements, we show that increased intra-octahedral distortion induces exciton localization processes and leads to formation of multiple photoinduced emissive colour centres. Ultimately, this leads to highly Stokes-shifted, ultrabroad white light emission at room temperature. 相似文献
163.
164.
Giulia Caron Guillaume Steyaert Alessandra Pagliara Frdric Reymond Patrizia Crivori Patrick Gaillard Pierre-Alain Carrupt Alex Avdeef John Comer KarlJ. Box HubertH. Girault Bernard Testa 《Helvetica chimica acta》1999,82(8):1211-1222
The objectives of this study were to validate new experimental techniques used to measure the log P of protonated drugs, and to investigate the inter- and intramolecular forces influencing the partitioning behavior of β-blockers in isotropic biphasic solvent systems. The lipophilicity parameters of a number of β-blockers were measured by two-phase titration, centrifugal partition chromatography (CPC), and cyclic voltammetry (CV) in one or more of the following solvent systems: octanol/water, 1,2-dichloroethane/water, and dibutyl ether/water. CV proved to be a promising technique for measuring the lipophilicity of protonated β-blockers. Derived parameters such as Δlog P (difference between log P in two different solvent systems, a parameter valid for a given solute in a given electrical form) and diff (difference between log P of two different electrical forms of a given solute, in the same system) yielded insights into inter- and intramolecular interactions characteristic of β-blockers. The relevance of these parameters in structure-permeation relationships is explored. 相似文献
165.
Giulia Caron Giuseppe Ermondi Donatella Boschi Pierre-Alain Carrupt Roberta Fruttero Bernard Testa Alberto Gasco 《Helvetica chimica acta》1999,82(10):1630-1639
Homologous N,N-dimethyl-phenylalkylamine oxides and N,N-dimethyl-diphenylalkylamine oxides were prepared. Their basicity and lipophilicity (octan-1-ol/H2O) were compared to those of the parent amines. In contrast to the amines, the basicity of all N,N-dimethyl-arylalkylamine oxides showed very limited pKa variations (range 4.65 – 5.01) with increasing chain length and number of Ph groups. The N-oxides in their neutral form had a log PN value lower by 2.77±0.34 (n=9) units than that of the parent amine. The log PC of the cationic N,N-dimethyl-diphenylalkylamines was lower than that of their neutral form, with a decrement diff(log PN−C) that increased from 3.25 to 4.21 in the homologous series. Unexpectedly, the decrement diff(log PN−C) for the N-oxides was much smaller than for the tertiary amines, being 0.23 for the aliphatic N,N-dimethyl-pentylamine oxide, 0.47±0.13 for the phenylalkylamine oxides, and 0.80±0.07 for the diphenylalkylamine oxides. In fact, the protonated N-oxides had log PC values that were quite comparable to those of the protonated parent amines. Because of the differences in basicity, the difference in distribution coefficients at physiological pH (log D7.4) between a tertiary arylalkylamine and its N-oxide was 0.82±0.66 (n=9). The pharmacokinetic implication is that N-oxygenation may have a smaller effect on the urinary excretion of tertiary amines than usually assumed. 相似文献
166.
Morandi S Locati D Ferrario F Chiesa G Arnoldi A 《Rapid communications in mass spectrometry : RCM》2005,19(2):153-161
In a study aimed at elucidation of the possible role of dietary phytoestrogens in the growth of breast cancer, it was necessary to develop a convenient, accurate, and reproducible method for the characterization and quantification of isoflavone metabolites in the serum of MMTV mice that were fed diets containing different amounts of these polyphenols. The analytical method is based on liquid chromatography with mass spectrometry in multiple reaction monitoring mode, using deuterated genistein as internal standard. The identified metabolites were genistein and dihydrodaidzein (DHD); their average concentrations in serum were 0.71 and 0.21 microM, respectively, for animals fed 1.5 mg/day of genistein and 0.7 mg/day of daidzein. This method assured a limit of quantification of 0.04 microM for genistein and 0.08 microM for DHD, and a limit of detection of 0.018 microM for genistein and 0.035 microM for DHD. The coefficient of variation was 8.9% for genistein and lower than 15% for DHD. This study provides the first data indicating the presence of dihydrodaidzein in serum of mice fed diets containing soy proteins. 相似文献
167.
168.
The CS2O+ ion and CS2O molecule were prepared and structurally characterized by mass spectrometric techniques as isolated species in the gas phase. The theoretical analysis, performed by B3LYP and CCSD(T) computational methods, predicted different CS2O+ isomers, SSCO+, O(CS2)+, SCSO+, SCOS+ and S(COS)+, and structurally related singlet and triplet CS2O. Experiment and theory agree in identifying the obtained CS2O+ ions as a mixture of SCSO+ and SCOS+ isomers. CS2O neutral species, prepared by neutralization-reionization mass spectrometry, were directly characterized as intact, long-lived species with a lifetime tau > or =2 micros. 相似文献
169.
The structure of aldehyde-terminated alkanethiol self-assembled monolayers (SAMs) on Au(111) is investigated using scanning tunneling microscopy (STM), atomic force microscopy (AFM), and density functional theory (DFT) calculations. For the first time, the structures of aldehyde-terminated SAMs are revealed with molecular resolution. SAMs of 11-mercapto-1-undecanal exhibit the basic (radical3xradical3)R30 degrees periodicity and form various c(4x2) superstructures upon annealing. In conjunction with DFT studies, the models of the (radical3xradical3)R30 degrees and the c(4x2) superstructures are constructed. In comparison with alkanethiol SAMs, the introduction of aldehyde-termini results in smaller domain size, lower degree of long-range order, large coverage of disordered areas, and higher density of missing molecules and other point defects within domains of closely packed molecules. The origin of these structural differences is mainly attributed to the strong dipole-dipole interactions among the aldehyde termini. 相似文献
170.
A group of differently substituted acetoxy- and methoxystilbenes were synthesised via Heck reaction. A comparison between the use--as coupling reagents--of iodobenzene derivatives and diazonium salts was performed. A successful microwave-assisted demethylation by pyridine hydrochloride of some methoxystilbenes was carried out. 相似文献