Reduction of allergenicity of irradiated ovalbumin in ovalbumin-allergic mice

Egg allergy is one of the most serious of the immediate hypersensitivity reactions to foods. Such an allergic disorder is mediated by IgE antibodies stimulated by T-helper type 2 (Th2) lymphocytes. This study was undertaken to evaluate changes of allergenicity and cytokine profiles by exposure of irradiated ovalbumin (OVA), a major allergen of egg white, in the OVA-allergic mice model. OVA solutions (2 mg/ml in 0.01 M phosphate buffered saline (PBS) were gamma-irradiated to 50 and 100 kGy. The allergenicity in the OVA-allergy-induced mice model was remarkably reduced when challenged with irradiated OVA. Cultures of spleen cells harvested from OVA-sensitized mice showed a significant decrease in Th2 cytokine levels of ILs-4 and -5 with a concomitant increase in Th1 cytokine levels of IL-12 when co-cultured with irradiated OVA. However, IFN-γ level decreased dependant on the radiation dose of co-cultured OVA. The levels of IgEs and Th2-cytokine were reduced dependant on the radiation dose. These data show that the irradiated OVA could downregulate the activity of Th2 lymphocytes in OVA-sensitized mice.     

微波促进下N,N-二甲基甲酰胺中的Knoevenagel反应

在微波促进下，芳醛与丙二腈或氰基乙酸乙酯在DMF中进行Knoevenagel缩合反应，以77％～98％的产率生成相应E-式烯烃。     

Microwave-assisted arylation of rac-(E)-3-acetoxy-1,3-diphenylprop-1-ene with arylboronic acids

The palladium-catalyzed arylation of rac-(E)-3-acetoxy-1,3-diphenylprop-1-ene with arylboronic acids was studied under controlled microwave irradiation conditions. A variety of different catalysts, bases, and solvents were explored in order to achieve optimum yields in the shortest possible reaction times. The best isolated yields were obtained using Pd₂(dba)₃·CHCl₃/PPh₃ as the catalytic system, potassium phosphate monohydrate as the base, and toluene/H₂O as a solvent system. Microwave irradiation using 5 mol % of the palladium catalyst for 90 s (max. temp 170 °C) generally afforded the cross-coupling products in good to excellent yields.     

微波辐射下9-芳基-10-对甲苯基多氢吖啶衍生物的合成

芳醛、5,5-二甲基-1，3-环已二酮（达米酮）与对甲基苯胺在以乙二醇为溶剂 ，微波辐射下反应生成一素列新的3，3，6，6-四甲基-1，8-二氧代-9-芳基-10-对 甲基苯基-1，2，3，4，5，6，7，8，9，10-十氢吖啶，产物的结构通过单晶X射线 衍射分析确证。     

Comparison of the Dynamics of Water Molecules in Crystals of Proton-Ordered Ice IX and Its Proton-Disordered Analog III

A computer simulation of proton-ordered ice IX and its proton-disordered analog III (768 molecules, 90 K) was carried out by the molecular dynamics method using Poltev–Malenkov's potential. For ice IX, the differences in the dynamic characteristics of molecules with O(1) and O(2) are much wider than those in the case of ice III. The libration spectrum of ice IX has a number of distinct acute peaks, and the spectrum of ice III is strongly smoothed. These peculiarities are explained by the proton ordering of ice IX and disordering of ice III. The latter is responsible for the great differences in the short- and especially long-range environment of water molecules in ice crystals and hence for the presence of many molecules with different dynamic characteristics. Thus averaging over a large number of different vibrational spectra of molecules leads to a smoothed total spectrum in the case of the proton-disordered crystal modification of ice.     

Metrological role of neutron activation analysis. IB. Inherent characteristics of relative INAA as a primary ratio method of measurement

This is the second part of a paper which deals with the advantages and disadvantages of relative instrumental neutron activation analysis concerning traceability and uncertainty, and the current scope and possible future extensions of neutron activation analysis as a primary ratio method. The first part of this paper has been published in this Journal [1]. Received: 19 March 2001 Accepted: 2 October 2001     

Strained Structure in Ho0.5Sr0.5MnO3

The Ho_0.5Sr_0.5MnO₃ perovskite, synthesized in air, has been studied by combining neutron powder and electron diffraction techniques. The Pnma-type structure exhibits a strong tilting of the MnO₆ octahedra. This octahedra tilting and microtwinning involve a complex strained structure. No structural transition is observed down to 1.4 K, but short-range A-type antiferromagnetism running over only a few perovskite subcells is evidenced below ≈90 K. The different behavior of this perovskite compared to other Ln_0.5Sr_0.5MnO₃ perovskites is discussed in terms of A-site cationic mismatch.     

Synthesis and Crystal Structure of 9-（ 4-M e tho xylphen yl ）-1,8-dioxo-3,4,5,6,7,9hexahydroxanthene under Microwave Irradiation

1INTRODUCTIONInthepastfewyears,potassiumchannelacti-vatorshavegainedincreasingattentionbecauseoftheirclinicalpotentialapplicationsinvariousdiseases.Oneofthemostpotentcompoundsamongthisnewclassofdrugsisthebenzopyranderivativecroma-kalim[1～4].Benzopyranaswellasitsderivativesex-hibitsextensivepharmacologicalandbiologicalacti-vities[5],suchasantibacterialactivities[6,,antitumor7]activity[8],hypotensiveeffect[9],antiproliferationef-fect[10],etc.Thetitlecompoundbearingabenzo-pyranstructuraluni…     

Synthesis and characterization of a new isocyanato carborane anion [7-OCN-7-CB10H12]; study on its reactivity toward amino containing compounds

The new isocyanato carborane anion, [7-OCN-7-CB₁₀H₁₂]⁻ was prepared by the reaction of 7-H₃N-7-CB₁₀H₁₂ with triphosgene in the presence of triethylamine. The structure of this compound was established by ¹H, ¹¹B and ¹³C NMR as well as IR spectroscopy. The reactivigty of this compound with a series of organic amines was investigated. The resulting ureas were obtained in good to excellent yields. This approach is suitable for development of compounds for use in tumor selective Boron Neutron Capture Therapy (BNCT).     

伯溴代烷的微波快速合成法

198 6年Ｒ .Ｊ.Ｇｉｇｎｅｒｅ[1 ] 和Ｒ .Ｇｅｄｙｅ[2 ] 首次报道将微波用于有机合成反应以来 ,大量实验事实证明[3] 微波不仅能极大地提高某些化学反应速率 ,而且能使一些在常规加热条件下几乎不能进行的反应得以完成、获得满意的收率。用伯醇在溴化氢溶液中微波条件下发生反应制备了伯溴代烷。1　实验部分ＷｈｉｒｌｐｏｏｌＴ1 2 0Ｘ微波炉 (四川大学无线电系改装 ,可连续发射微波 ,功率连续可调 )、ＷＺＳ -Ｉ阿贝折光仪 (未校正 )。工业溴化氢 (Ｃ =40 % ,ｄ =1 38) ,其余试剂均为ＣＰ级。合成通法　将适量的醇、一定量的浓硫酸和过…