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71.
Hai M Bernath K Tawfik D Magdassi S 《Langmuir : the ACS journal of surfaces and colloids》2004,20(6):2081-2085
We present a new and facile method to evaluate w/o/w emulsions containing fluorescent markers by flow cytometry. Flow cytometry allows simultaneous measurement of w/o/w emulsion droplets "marked" with a fluorescent marker or "blank" without the need for complicated sample preparation. The yield of preparation of the w/o/w emulsion and the release rate of the fluorescent marker FITC-BSA were investigated by this new method. The release fraction (after 24 h) of FITC-BSA from the w/o/w emulsion decreased with increasing concentration of FITC-BSA inside the internal phase, just like the release fraction of NaCl as marker from the w/o/w emulsion. Flow cytometry results show that the yield and release behavior in w/o/w emulsions are in agreement with results reported by more complicated methods. 相似文献
72.
Shlomo Vinner 《The Journal of Mathematical Behavior》2007,26(1):1-10
An attempt is made to analyze mathematical behavior from more general psychological perspectives. The mathematical language is a special case of the human language, which is a form of expression. Many people use common language in a meaningless way. The same is true about the mathematical language. Rituals are other forms of expression. Many people identify rituals in many mathematical contexts (procedures, argumentation). Thus, quite often, they behave in a meaningless way as required by many rituals. On the other hand, the community of mathematics education struggles for meaningful learning. This can be regarded as a special case of man's search for meaning. The general claims will be illustrated by some examples from various mathematical contexts. 相似文献
73.
Ariel Shitrit Sandhya Mardhekar Israel Alshanski Dr. Prashant Jain Rakesh Raigawali Dr. Chethan D. Shanthamurthy Dr. Raghavendra Kikkeri Prof. Shlomo Yitzchaik Dr. Mattan Hurevich 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(55):e202202193
Heparan sulfate glycosaminoglycans provides extracellular matrix defense against heavy metals cytotoxicity. Identifying the precise glycan sequences that bind a particular heavy metal ion is a key for understanding those interactions. Here, electrochemical and surface characterization techniques were used to elucidate the relation between the glycans structural motifs, uronic acid stereochemistry, and sulfation regiochemistry to heavy metal ions binding. A divergent strategy was employed to access a small library of structurally well-defined tetrasaccharides analogs with different sulfation patterns and uronic acid compositions. These tetrasaccharides were electrochemically grafted onto glassy carbon electrodes and their response to heavy metal ions was monitored by electrochemical impedance spectroscopy. Key differences in the binding of Hg(II), Cd(II), and Pb(II) were associated with a combination of the uronic acid type and the sulfation pattern. 相似文献
74.
Itzhak Halevy Shlomo Haroush Yosef Eisen Ido Silberman Dany Moreno Amir Hen Mike L. Winterrose Sanjit Ghose Zhiqiang Chen 《Hyperfine Interactions》2010,197(1-3):135-141
Annealed (H1) and cold-rolled (H2) HAVAR has been studied using high-pressure synchrotron X-ray diffraction. A structural phase transformation was discovered at ~13 GPa at ambient temperature, transforming from m ??3 m (S.G. 225) to P 63/m m c (S.G. 194) symmetry. The transition was not reversible on pressure release. The low-pressure cubic phase was found to be more compressible than the high-pressure hexagonal phase. Conventional Mössbauer and NFS shows that the HAVAR is not magnetic at room temperature and no splitting is observed. The SQUID indicates a huge difference in the temperature dependence of the magnetic susceptibility between the cold Rolled HAVAR compared to the annealed HAVAR. 相似文献
75.
An efficient procedure for transferring an oxygen atom to thiazole-containing compounds, resulting in the corresponding N-oxides, was developed by using HOF x CH3CN; mild reaction conditions, high yields and easy purification are the main features of this novel route, while X-ray structural analysis reveals a hydrogen bond between the N-oxide functionality and a water molecule. 相似文献
76.
Gold electrode was modified with a 4-aminothiophenol layer (4-ATPh) to immobilize DNA. The immobilized DNA served as a template for the alignment of positively charged anilinium ions. The electrochemical oxidation of the anilinium ions resulted in wrapping of the DNA with polyaniline. This polyaniline coated DNA was characterized by cyclic voltammetry (CV), impedance spectroscopy and UV-VIS absorption spectroscopy. 相似文献
77.
The direct action of fluorine on bromine at ?78° produces BrF which, without any isolation or purification, adds readily across various double bonds providing there is some hydrogen donor in the reaction mixture. Only trans addition of the elements of BrF was observed. When the reaction was applied to enons an easy elimination of HF can take place thus producing α-bromo enons.In our previous work we described the reaction of some olefins with IF, a reagent which was prepared by the action of F2 on I2[1]. The literature deals with several other fluorohalogens, among them the three known bromo-fluoro compounds, BrF, BrF3 and BrF5, although only the last two are well characterized[2]. However, because of the instability and the high reactivity of these compounds, they have hardly been employed in organic chemistry[3].We wish to describe here for the first time, an efficient and convenient method of synthesizing vicinal bromo-fluoro compounds using the primary source of the fluorine atoms, namely elemental fluorine itself[4].When a mixture of F2/N2 is bubbled through a cold (?78°C), dilute solution of Br2 (20 mmolar) in CFCl3 (Freon) the bromine disappears and mainly BrF is produced. However, despite previous efforts, it seems that this compound cannot be isolated since it disproportionates easily to the very reactive BrF3 and halogen on the aromatic ring can not be ascertained. The third product proved to be the corresponding bromo-ethoxy compound XV (15% yield). Prolonged chromatography or traces of HF from the reaction mixture results in the elimination of HF thus producing, quantitatively, 6-bromocumarin XVI[8]. 2-Bromo-3-fluoro cyclopentanone XVII (oil) if formed in 90% yield and isolated in almost pure form. As in the case of cumarin, XVII readily loses HF producing the 2-bromoclopentenone (XVIII)[9] in quantitative yield. 相似文献
78.
Vladimir Drinfeld Shlomo Gelaki Dmitri Nikshych Victor Ostrik 《Selecta Mathematica, New Series》2010,16(1):1-119
We introduce a new notion of the core of a braided fusion category. It allows to separate the part of a braided fusion category that does not come from finite groups. We also give a comprehensive and self-contained exposition of the known results on braided fusion categories without assuming them pre-modular or non-degenerate. The guiding heuristic principle of our work is an analogy between braided fusion categories and Casimir Lie algebras. 相似文献
79.
Mathieu Meyer Shlomo Reisner 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2011,81(1):93-100
We present a method that allows us to prove that the volume product of polygons in ℝ2 with at most n vertices is bounded from above by the volume product of regular polygons with n vertices. The same method shows that the volume product of polygons is bounded from below by the volume product of triangles (or parallelograms in the centrally symmetric case). These last results give a new proof of theorems of K. Mahler. The cases of equality are completely described. 相似文献
80.
Emmer MB Silman S Silverman CA Levitt H 《The Journal of the Acoustical Society of America》2006,120(3):1467-1473
Although numerous studies have investigated temporal integration of the acoustic-reflex threshold (ART), research is lacking on the effect of age on temporal integration of the ART. Therefore the effect of age on temporal integration of the ART was investigated for a broad-band noise (BBN) activator. Subjects consisted of two groups of adults with normal-hearing sensitivity: one group of 20 young adults (ten males and ten females, ages 18-29 years, with a mean age of 24 years) and one group of 20 older adults (ten males and ten females, ages 59-75 years, with a mean age of 67.5 years). Activating stimulus durations were 12, 25, 50, 100, 200, 300, 500, and 1000 ms. Significant main effects for duration and age were obtained. That is, as the duration increased, the acoustic reflex threshold for BBN decreased. The interactions of duration x age group and duration x hearing level were not significant. The result of pair-wise analysis indicated statistically significant differences between the two age groups at durations of 20 ms and longer. The observed age effect on temporal integration of the ART for the BBN activator is interpreted in relation to senescent changes in the auditory system. 相似文献