鱼肝铁蛋白铁核表层接受电子能力的研究

采用直接电化学技术研究鱼肝铁蛋白 (LiverFerritinofDasyatisakajei,DALF)铁核表层接受还原电子的快慢速率和释放铁的动力学级数及规律。实验结果表明,在有氧环境下,DALF铁核表层以两相行为的方式快速地从铂金电极上获得还原电子且用于释放铁反应,其释放铁的还原电位分别为 -125mV和 -375mV(vs.NHE,下同 )。在控制还原电位为 -200mV和 -500mV的条件下,DALF铁核表层释放铁的速率分别为11.1Fe3 +/(DALF·min)和33.3Fe3 +/(DALF·min),因而认为DALF从铂金电极接受电子和释放铁的速率快慢与还原电位高低有关。血红素不仅能络合于DALF蛋白壳 (DALFh)上,而且还能加速DALFh 释放铁的速率,但无法增加DALFh 释放铁的总量。DALF铁核结构中的磷铁组成存在着非均匀性。

铁核结构对马脾铁蛋白释放铁动力学的影响

建立H+参与马脾铁蛋白释放铁的动力学方程。H+以 1 / 2级反应方式参与铁蛋白释放铁核表层的铁。在酸性介质 ( pH 6 5)中 ,铁蛋白释放铁的总平均速率 ( 332Fe3+/HSF·min)比在碱性介质 ( pH8 0 )中释放铁的总平均速率 ( 73Fe3+/HSF·min)高 4 6倍。铁蛋白的铁核结构和外加的磷酸盐均能影响该蛋白释放铁的速率 ,但并不改变其反应级数。

马脾铁蛋白铁核表层特性

马脾铁蛋白整体铁核的磷酸盐与铁组成比是1:8±0.5,而表层组成比却是1:3±0.2,在pH7～10内,铁蛋白随着pH值递增,它以65±5磷原子/蛋白分子/pH速率释放无机磷酸盐和185±5铁原子/蛋白分子/pH速率释放铁,其磷酸盐与铁释放分子比也是1:3±0.5,推测这一过程是发生于铁核表层组成的变化,随着体系pH增加,氢氧根离子参与铁蛋白铁核组成,取代铁核表层某些磷铁成份,构成新的铁核表层组成,使铁蛋白氧化还原中间电位以-115mV/pH速率向负线性漂移。

中空玻珠/超微铁核壳复合粒子的制备与微观结构的表征

用ATPU作表面活性剂制备出了超微铁包裹中空玻珠核壳复合粒子,详细地研究了中空玻珠的性质以及ATPU的用量对中空玻珠/超微铁核壳复合粒子的微观结构的影响。结果表明:粒径小、分布窄以及适当用量的空心玻璃微珠,有利于制备出小粒径的超微铁均匀致密包裹空心玻珠的核壳结构复合粒子;ATPU的用量也会对复合粒子的结构与形貌有较大的影响。

两种物态方程下铁核塌缩型超新星爆发机制的数值模拟

【目的】物态方程对铁核塌缩型超新星爆发过程中铁核塌缩、激波产生及其传播等都将产生影响。为了探索对超新星爆发机制解释更合理的物态方程,对比分析2种物态方程对铁核塌缩型超新星爆发的影响。【方法】以新前身星模型数据作为输入参量,分别采用Lattimer等(LS物态方程)和王贻仁等(W物态方程)提出的物态方程,对不同初始质量的铁核塌缩型超新星的爆发过程进行数值模拟,并对比分析模拟结果。【结果】在LS物态方程下,铁核塌缩结束时恒星的中心密度最高只达到核密度的1.5倍,且得到的同模区偏小,中微子的能量损失较大,这使激波在向外传播过程中损失了较多能量,不利于解释超新星的成功爆发。【结论】W物态方程更能合理解释超新星的成功爆发。

马脾铁蛋白铁核表层磷铁组成稳定性

马脾铁蛋白络合Ｆｅ２＋的能力与它的铁核表层磷酸盐和Ｆｅ３＋组成含量有关．ＯＨ－参与铁核表层组成，并迫使铁蛋白释放Ｆｅ３＋．用强还原剂还原铁核表层时，铁蛋白只能释放磷酸盐．在Ｆｅ２＋、磷酸盐和氧化剂存在下，铁蛋白能贮存原铁核总磷酸盐量的６０％的磷．

高铁核心零部件实现“重庆造”

近日，重庆凯瑞车辆传动制造有限公司（以下简称重庆凯瑞传动）成功研发出具有自主知识产权的CW350（D）高铁齿轮箱．形成高铁减速传动装置研发生产能力，打破了闲外技术封锁。

铁核结构对马脾铁蛋白释放铁动力学的影响

铁蛋白的主要生理功能是储存机体中过剩的铁及释放已储存的铁给需铁的细胞生物。此外，铁蛋白还能表达吸氢活性及从物理电极上接受电子等的新的生理功能。本文选用不同铁核结构为探针研究马脾铁蛋白（HSF）释放铁的动力学规律．为今后深入探讨铁蛋白的新生理功能提供有价值的理论研究依据。

核Drell-Yan过程和混合重标度模型

利用混合重标度模型计算铁核与氘核的Ｄｒｅｌ－Ｙａｎ截面比随ｘＦ的变化。

双(π-芳烃)铁(Ⅱ)化合物的Mssbauer分析

铁的简单配合物及羰基化合物的Mossbauer研究已有报道,对有机铁化合物的相应工作进行得较少.本文报道一类具有夹心结构的有机铁化合物的Fe Mossbauer参数及其与结构的一些关系.实验双(π-芳烃)铁化合物样品按文献[1]方法合成,经重结晶.Fe Mossbauer谱用OXFORD INS.MS500型Mossbauer谱仪室温下测定,放射源为Co/Rh,强度为25mCi;样品厚度约20mgFe/cm;谱仪速度用超纯α-铁箔标定;化学位移值相对于室温的α-Fe谱线中心;谱线及参数经计算机拟合得到,收敛判据为x<1.1.

可高产量产生氢的氢化酶

德国普朗克研究院（Max Planck Institute）发现了一种酶，每秒能够产生10000个氢分子。这种具有双铁核（FeFe）的酶叫作氢化酶，是转化过程的关键。该过程中两个电子与两个质子结合形成氢。

Immunolcocalization of actin in intact and DNA-and histone-depleted nuclei and chromosomes of allium cepa

The presence of actin in eukaryotic nuclei and chromosomes, and especially in higher plant nuclei and chromosomes, has not been well established. We detected actin in meristematic cells of Allium cepa with indirect immunofluorescence technique and observed bright fluorescence in the intact nuclei and chromosomes, indicating that actin is present in the nuclei and chromosomes of the higher plant. We labeled sections of the meristematic cells of A. cepa with immunogold technique, gold particles were found over the whole nuclei and a number of gold particles were concentrated in condensed chromatin and nucleoli, confirming the results of the immunofluoresence observations. We treated the nuclei and chromosomes of A.cepa with DNase I and 2M NaCl and obtained DNA- and histone-depleted nuclei and chromosomes. Indirect immunofluorescence tests showed that the DNA- and histonedepleted nuclei and chromosomes reacted positively with the anti-actin antibodies. These results demonstrate that actin exists not only in intact nuclei and chromosomes,but also in DNA- and histone-depleted nuclei and chrmosomes of the plant. In addition, our immuno-fluorescence tests indicate that tropomyosin is present in the nuclei and chromosomes of A. cepa.

Nucleation Mechanism of Iron in an External Magnetic Field

In this work,the solidification of liquid iron with or without external magnetic field was investigated by using two molecular dynamics methods,namely direct cooling and two-phase simulation.The influence of external magnetic field on the solidification is characterized by the critical temperature and radial distribution functions.Our computational results show that under external magnetic field,the solidification point tends to decrease significantly.By further analyzing the diffusion coefficients and viscosity,we attribute the effect to the stronger fluctuation of liquid iron atoms driven by the external magnetic field.

Synthesis of Substituted u-Oxo-bis[tetra-phenyl porphyrinatoiron] Compounds from Free Base Porphyrins by a One-pot Method

A novel method for synthesis of substituted u-oxo-bis[tetraphenyl porphyrinatoiron] compotmds （[TRPPFe]20） based on the reaction among free base porphyrins （TRPPH2）, FeSO4·7H2O and H2O in one pot was proposed and investigated. Four kinds of [TRPPFe]2O were synthesized by this novel synthetic method, and their structures were characterized by elemental analysis, infrared spectra and UV-vis spectroscopy. The reaction conditions, including the effect of different iron salts on the formation of [TRPPFe]2O, the reaction time between FeSO4-7H2O and TRPPH2, the molar ratio of FeSO4-7H2O/TRPPH2 as well as the volume ratio of H2O/DMF, were investigated. The [TRPPFe]2O yield of 93% 98% could be obtained under the following optimal conditions： the reaction time of FeSOn-7H2O with TRPPH2 was about 10 h, the molar ratio of FeSOn-7H2O/TRPPH2 about 5 ： 1, and the volume ratio of H2O/DMF exceeded 2 ： 1. Further research indicated that only TRPPFeCI were formed once FeSOn-7H2O was replaced by FeCl2-4H2O, the reason of which might be that halogen ions in iron salts interfered the formation of [TRPPFe]2O, suggesting that halogen ions should be avoided in this novel synthetic method.

Methanol oxidation over shell-core MOx/Fe2O3（M = Mo, V, Nb） catalysts

We present a comparison of Mo, V and Nb oxides as shell materials atop haematite cores used for selective methanol oxidation. While Mo and V both yield high selectivity to formaldehyde, Nb does not. Very different reactivity patterns are seen for Nb, which mainly shows dehydrogenation (to CO) and dehydration (to DME), indicating the lack of a complete shell, while Raman spectroscopy shows that the Mo and V formation process is not followed by NbOx. We suggest this is due to the large differences in mobility within the solid materials during formation, NbOx requiring significantly higher (and deleterious) calcination temperatures to allow sufficient mobility for shell completion.

Theoretical Studies on the Fe-M Interactions and 31p NMR in Fe（CO）3（EtPhPpy）2MX2 （X=NCS, SCN, CI; M=Zn, Cd, Hg）

To study the Fe-M interactions and their effects on 31p NMR, the structures of Fe（CO）3（EtPhPpy）2 1, Fe（CO）3（EtPhPpy）2M（NCS）2 （2： M=Zn, 3： M=Cd, 4： M=Hg） and Fe（CO）3（EtPhPpy）2CdX2 （5： X=C1, 6： X=SCN） were investigated by density functional theory （DFT） PBE0 method. The stabilities S of complexes follow S（2）〉S（3）〉S（4） and S（3）,.~S（6）〉S（5）, indicating that 6 is stable and may be synthesized. The complexes with thiocyanate are more stable than that with chloride in Fe（CO）3（EtPhPpy）2CdX2. The strength I of Fe-M interactions follows I（2）≈I（3）〈I（4）. The Fe-Cd interactions of 3 and 6, which contain thiocyanate, are stronger than that of 5 with chloride. The charge-transfer, which enhances with the increasing of Fe-M interaction strength, comes from Et, Ph, py, CO groups towards P, Fe, and M atoms. Because the delocalization of thiocyanate disperses the charge of M2＋, the charge-transfer of the complexes with thiocyanate is stronger than that with chloride. There is a a-bond between Fe and Hg atoms in 4. However, in binuclear complexes except 4, the Fe-M interactions act as nFe→nM, σP-Fe→nM and σC-Fe→nM delocalization, and the N-M interactions mainly act as nN→nM delocalization. In binuclear complexes, due to the Fe→M interactions, the strong σFe--C→σ＊Fe--p or σFe-Hg→σ＊Fe--I2 delocalization and the charge-transfer, the electron density on P nucleus is increased, and thus upfield 31p chemical shifts are caused （compared with mononuclear complex 1）.

Characteristics and geological genesis of pyrites in coal of Huainan

Using optical microscope and scanning electron microscopy （SEM）, revealed the content of pyrite and the microscopic or sub-microscopic occurrence features of pyrite in coal of Huainan. The samples of this study are from four different mines in Huainan coal field. The results show that, in general, the coal of Huainan is low sulfur coal, but the con- tent of pyrite in Guqiao mine is relatively higher. The occurrence types of pyrite in coal mainly include： strawberry ball pyrites, massive pyrites, tuberculoid pyrite and pyrite filling in cracks or joints. After analysis based on three indicating facies parameters IAA, IS and/R, the reason for the higher level of pyrite component is that the deoxidization of swamp wa- ter is stronger, salinity is greater and the hydrodynamic is bad. The strawberry ball pyrites found in Guqiao mostly formed in the syngenesis stage. The spherical raspberry pyrites symbiotic with clay minerals was formed due to the reaction of H2S with Fe in the grid of silicate crystal.

Preparation of a p-n heterojunction BiFeO_3@TiO_2 photocatalyst with a core–shell structure for visible-light photocatalytic degradation

Magnetically separable bismuth ferrite(BiFeO3)nanoparticles were fabricated by a citrate self‐combustion method and coated with titanium dioxide(TiO2)by hydrolysis of titanium butoxide(Ti(OBu)4)to form BiFeO3@TiO2core-shell nanocomposites with different mass ratios of TiO2to BiFeO3.The photocatalytic performance of the catalysts was comprehensively investigated via photocatalytic oxidation of methyl violet(MV)under both ultraviolet and visible‐light irradiation.The BiFeO3@TiO2samples exhibited better photocatalytic performance than either BiFeO3or TiO2alone,and a BiFeO3@TiO2sample with a mass ratio of1:1and TiO2shell thickness of50-100nm showed the highest photo‐oxidation activity of the catalysts.The enhanced photocatalytic activity was ascribed to the formation of a p‐n junction of BiFeO3and TiO2with high charge separation efficiency as well as strong light absorption ability.Photoelectrochemical Mott-Schottky(MS)measurements revealed that both the charge carrier transportation and donor density of BiFeO3were markedly enhanced after introduction of TiO2.The mechanism of MV degradation is mainly attributed to hydroxyl radicals and photogenerated electrons based on energy band theory and the formation of an internal electrostatic field.In addition,the unique core-shell structure of BiFeO3@TiO2also promotes charge transfer at the BiFeO3/TiO2interface by increasing the contact area between BiFeO3and TiO2.Finally,the photocatalytic activity of BiFeO3@TiO2was further confirmed by degradation of other industrial dyes under visible‐light irradiation.

A case of acute infectious mononucleosis presenting with very high ferritin

Hepatitis is an important but uncommon manifestation of acute Epstein Barr infection. Infectious mononucleosis is usually a disease of young adults. We report a case of infectious mononucleosis in a 72-year old jaundiced gentleman with ferritin level of 2438 that normalised on clinical improvement.

Selective photocatalytic reduction of CO2 to CO mediated by a[FeFe]-hydrogenase model with a 1,2-phenylene S-to-S bridge

Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.