A new fluorescent quinoline derivative toward the acid-responsivity in both solution and solid states

In this article, an acid-responsive luminescent material, 1,4-di(quinoline-6-yl)buta-1,3-diyne (DQBD) is designed and synthesized. Upon different pH values, gradual changes of fluorescence colors for DQBD in both solution and solid phases are demonstrated due to the protonation effect. Moreover, such responsive characteristics can also be reversible, suggesting DQBD as a promising fluorescent material with great potential for reusable- and accurate-pH sensors in the future.     

Chemical composition of Erycibe schmidtii and antiproliferative activity of scopoletin on immature dendritic cells

Abstract

Immature dendritic cells (iDCs) play very important roles in the pathological process of rheumatoid arthritis (RA). Therefore, it is urgent to search for natural products with antiproliferative activity on iDCs for anti-RA drug discovery. Erycibe schmidtii, a traditional Chinese medicine, has been used to treat RA in China. Its bioactive ingredients on RA are still unclear. In this study, twenty compounds including a new caffeoylquinic acid derivative, 3-O-caffeoyl-4-O-syringoylquinic acid methyl ester (16), were isolated from E. schmidtii. Their structures were elucidated by NMR and mass spectroscopic analysis, and comparison with literature data. Seventeen compounds were obtained from this plant for the first time, and ten were first found from the genus Erycibe. Scopoletin (1, 5.0?μM) functionally reduced proliferation level of bone marrow immature dendritic cells (BM-iDCs) more than 50%, relative to vehicle. However, scopoletin (1) exhibited no effect on the phagocytosis or survival of BM-iDCs in vitro.     

Crystal Structure of O，O－Diethyl－α－（β－triphenylgermanyl）－propionoyloxy Methylphosphonate

ＣｒｙｓｔａｌＳｔｒｕｃｔｕｒｅｏｆＯ，Ｏ－Ｄｉｅｔｈｙｌ－α－（β－ｔｒｉｐｈｅｎｙｌｇｅｒｍａｎｙｌ）－ｐｒｏｐｉｏｎｏｙｌｏｘｙＭｅｔｈｙｌｐｈｏｓｐｈｏｎａｔｅＣｈｅｎＲｕ－Ｙｕ；ＭａｏＬｉ－Ｊｕａｎ；ＬｉｕＡｉ－Ｌｉｎ（Ｉｎｓｔｉｔｕｔｅｏ...     

Conductivity anisotropy in directionally solidified CaZrO3---CaSZ and MgO-MgSZ eutectics

The results of the impedance spectroscopy measurements on eutectic samples based on zirconium oxide are presented here. Samples of CaZrO₃---ZrO₂(cubic) and MgO---ZrO₂(cubic) have been grown by a directional solidification procedure such that the different phases appear nearly oriented along the growth direction (lamellae in the system of CaZrO₃-ZrO₂(cubic) and fibers of MgO in a ZrO₂ matrix in the other system). The DC electrical conductivity has been measured by impedance spectroscopy along and across the growth axis. For CaZrO₃---ZrO₂ the coductivity is clearly anisotropic. The following values for σT have been obtained: the conductivity at 600 °C equals 2.0 × 10⁻⁶ Ω⁻¹ cm⁻¹ perpendicular to the fiber axis and 1.4 × 10⁻⁵ Ω⁻¹ cm⁻¹ parallel to it and with an activation energy of 1.3 eV for σT. For MgO---ZrO₂(cubic) the isotropic value of the conductivity at 600 °C is 10⁻⁴ Ω⁻¹ cm⁻¹ with activation energy for σT of 1.5 eV. The anisotropic conductivity in the CaZrO₃---ZrO₂ (cubic) system has been explained by a model of an ordered stacking of oxygen conducting (cubic ZrO₂) and non-conducting (CaZrO₃ or MgO) phases.     

To the problem of a strong differentiability of integrals along different directions

It is proved that for any given sequence (σ _n ,n ∈ ℕ)=Γ₀ ⊂ Γ, where Γ is the set of all directions in ℝ² (i.e., pairs of orthogonal straight lines) there exists a locally integrable functionf on ℝ² such that: (1) for almost all directionsσ ∈ Γ\Γ₀ the integral ∫f is differentiable with respect to the familyB _2σ of open rectangles with sides parallel to the straight lines fromσ: (2) for every directionσ _n ∈ Γ₀ the upper derivative of ∫f with respect toB _{2σ n} equals +∞; (3) for every directionσ ∈ Γ the upper derivative of ∫ |f| with respect toB _2σ equals +∞.     

Numerical solution of fractional order differential equations by extrapolation

We present an extrapolation type algorithm for the numerical solution of fractional order differential equations. It is based on the new result that the sequence of approximate solutions of these equations, computed by means of a recently published algorithm by Diethelm [6], possesses an asymptotic expansion with respect to the stepsize. From this we conclude that the application of extrapolation is justified, and we obtain a very efficient differential equation solver with practically no additional numerical costs. This is also illustrated by a number of numerical examples. This revised version was published online in August 2006 with corrections to the Cover Date.     

远达函数的可导性与远达点的存在性

该文考察Banach空间上的远达函数的可导性与远达点的存在性间的关系，指出某些Banach空间上的远达函数(对有界闭集而言)具等于1或-1的单侧方向导数蕴含远达点的存在性，并给出了Banach空间CLUR和LUR的新等价刻划．     

The theory of concentrated Langevin distributions

The density of the Langevin (or Fisher-Von Mises) distribution is proportional to exp κμ′x, where x and the modal vector μ are unit vectors in $\text{R}$^q. κ (≥0) is called the concentration parameter. The distribution of statistics for testing hypotheses about the modal vectors of m distributions simplify greatly as the concentration parameters tend to infinity. The non-null distributions are obtained for statistics appropriate when κ₁,…,κ_m are known but tend to infinity, and are unknown but equal to κ which tends to infinity. The three null hypotheses are H₀₁:μ = μ₀(m=1), H₀₂:μ₁ = … =μ_m, H₀₃:μ_i?V, i=1,…,m In each case a sequence of alternatives is taken tending to the null hypothesis.     

Analysis of directional radiative behavior and heating efficiency for a gas-fired radiant burner

For the purpose of energy conservation and uniform heating of object surface, a gas-fired porous radiant burner with a bundle of reflecting tubes is developed. A physical model is developed to simulate the directional radiative behavior of this heating device, in which the Monte Carlo method based on the concept of radiation distribution factor is used to compute the directional radiative behavior. The effects of relating parameters on the directional behavior of radiative heating and the heating efficiency are analyzed. With the increase of the length-to-radius ratio of tube, the radiation heating efficiency decreases, but the radiation energy incident on the object surface is more collimated. The radiation heating efficiency increases with the specular reflectivity. With the increase in length of tube segment with specular reflective surface, the radiation heating efficiency increases, but the extent of concentration and collimation of radiative energy decreases. For real design of the heating device, some trade-offs are needed to balance the radiation heating efficiency and the uniformity of radiative heating of object surface.     

Trimethylsilylation and methylation of 1-hydroxybenzotriazole 3-oxide

Trimethylsilylation and methylation of 1 -hydroxybenzotriazole 3-oxide (1) proceed regioselectively and afford 1-trimethylsilyloxy- and 1-methoxybenzotriazole 3-oxides, respectively. The first compound easily undergoes fast hydrolysis and methanolysis, but does not react with nitroethane at 20 °C. A fast reversible 1,5-O,O-migration of the SiMe₃ group is observed for this compound.The authors thank V. I. Gulevskaya for DTA analysis of compound4.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2283–2285, November, 1995.The present work was supported by the Russian Foundation for Basic Research (project No. 93-03-18461).