可识别Al~(3+)的香豆素类荧光增强型探针的合成及性能

以间苯二酚为起始原料,经Pechmann缩合、甲酰化得7-羟基-4-甲基-8-甲酰基香豆素,继而与烟酰肼缩合制备了基于香豆素骨架的Schiff碱L,通过1 H,13 C NMR,MS对其结构进行了充分表征.以此为探针分子,利用UVVis、荧光光谱系统研究了该探针分子L与Al~(3+)的相互作用.结果表明,探针分子L对Al~(3+)具有良好的选择性识别作用,其灵敏度高(检测限达到3.1×10-8 mol·L-1),并且受其它金属离子的干扰小.     

一种色氨酸修饰的香豆素类Cu2+荧光探针的合成及性能研究

摘要:本文设计、合成了一种色氨酸修饰的香豆素类荧光探针香豆素色氨酸甲酯,它以色氨酸基团作为金属离子的识别位点、以香豆素基团作为荧光信号基团.实验结果表明:在水溶液中该探针能够对Cu2+表现出荧光猝灭效应,而相同测试条件下其他重金属离子的加入对探针的荧光发射几乎没有影响,因此该探针对Cu2+表现出选择性识别作用.     

香豆素衍生物荧光探针的合成及性能研究

以香豆素衍生物为基本原料合成了一种新型荧光分子探针TK.通过研究荧光分子探针TK在中性缓冲溶液中对金属离子的识别性能.结果显示,TK可以选择性荧光猝灭识别Cu2+、Fe3+.TK与Fe3+络合后,TK在351nm处的荧光峰强度发生猝灭,猝灭幅度为31％;与Cu2络合后,TK在474nm的荧光峰强度几乎完全猝灭,猝灭幅度达97％.经定量分析显示,TK与Cu2+形成了1∶1型络合物.通过金属离子竞争实验表明,常见的金属离子均不干扰TK对Cu2+的检测.     

高选择性新型喹啉衍生物Fe~(3+)荧光探针的合成及光学性质研究

设计、合成了一种利用"Click Chemistry"构建的基于含喹啉染料的过渡金属离子荧光探针HQT.探针分子HQT在乙腈-水溶液中对Fe3+有很好的选择性识别且最大发射波长由405nm左右红移至500nm.而其它过渡金属离子的存在对Fe3+的检测不造成干扰且工作的p H(3-11)范围广,该化合物是一种高选择性的Fe3+荧光探针.     

香豆素希夫碱的合成及其金属离子识别性能

3-氨基香豆素及其衍生物是一类很有研究价值的化合物.文中以2,4-二羟基苯甲醛和N-乙酰甘氨酸为原料,通过Perkin反应合成3-氨基-7-羟基香豆素,分别与两种芳香醛基化合物3-醛基-7-N,N二乙基氨基香豆素和2,4-二羟基苯甲醛经缩合反应合成了2种新型的香豆素希夫碱化合物(4a和4b),并采用傅里叶红外光谱、核磁共振谱、紫外-可见光谱和荧光光谱等方法对化合物的结构、光物理性能和金属离子识别性能进行了表征.结果表明:4a和4b具有较弱的荧光;4a对Ni2+具有较好的选择性识别作用,有可能用作Ni2+比色探针.     

1,8-萘酐类铅离子荧光探针的合成及荧光性质研究

以1,8-萘酐和萘乙二胺为原料设计合成了一种新的铅离子荧光探针M1,并对其结构进行了表征.荧光光谱实验表明:在乙醇溶液中,M1对Pb2+表现出了识别性能,随Pb2+的加入,其荧光光谱强度发生明显猝灭,而对Na+、K+、Ag+、Hg2+、Cr3+等离子无明显响应.Job’s plot实验显示M1与金属离子形成结合比为1∶1的配合物,Pb2+在0～9×10-5 mol·L-1范围内,探针的荧光强度与其浓度成线性关系.     

丹酰基团修饰的喹啉衍生物作为Cu2+和Hg2+荧光探针的研究

合成并表征了一种具有良好水溶性的荧光探针—8?(丹磺酰氨基)喹啉,它能够在水溶液中荧光识别和检测Cu2+和Hg2+.随着这2种离子浓度的增加,该探针的荧光发射强度均发生较大程度的猝灭,而相同测试条件下,其他9种所测试的常见重金属离子对该荧光探针的荧光发射性质几乎没有影响.因此,这是一种对Cu2+和Hg2+具有选择性识别的荧光探针.     

基于检测铜离子的香豆素水合肼希夫碱荧光探针的研究

设计合成了一种基于新型香豆素水合肼希夫碱荧光探针,结构经。HNMR表征．利用荧光光谱研究了该探针分子对铜离子的识别作用．实验表明,该探针对铜离子具有较好的选择性识别能力,加入铜离子后,该探针的荧光发射强度显著减弱,并且荧光发射强度随着Cu^2＋浓度的增加而减弱．通过荧光离子滴定实验对其选择性和抗干扰能力进行了系统研究,发现加入其他常见金属离子（如Al^3＋、Ca^2＋、Co^2＋、Cr^3＋、Fe^3＋、K^＋、Mg^2＋、Na^＋、Ni^2＋、Zn^2＋等）,荧光强度没有发生变化,并且上述各种离子分别与铜离子共存时,对其没有干扰．结果表明,香豆素水合肼希夫碱荧光探针对铜离子具有较高选择性识别．     

香豆素修饰SBA-15材料及其对Fe~(3+)的识别和吸附性能

通过将香豆素探针以共价键负载到介孔硅材料SBA-15上,合成了一种无机-有机杂化荧光材料SBA-K,FT-IR、TEM表征结果证明香豆素探针成功负载于SBA-15上,负载后介孔材料的有序孔道没有被破坏。在HEPES悬浮液(0.02 M,CH3OH/water=99.5/0.5,v/v,p H 7.2)中,SBA-K在常见金属离子(K+,Na+,Ca2+,Mg2+,Cd2+,Ag+,Fe3+,Pb2+,Hg2+,Cr3+,Co2+,Ni2+,Fe3+,Zn2+)中能够专一性地荧光猝灭识别Fe3+。Fe3+可使体系荧光猝灭98%,引起体系颜色由无色立即变为棕黄色。此外,SBA-K对Fe3+表现较强的吸附能力,吸附率可达92.7%。     

咔唑衍生物的合成及其对Zn2+和Cu2+的选择性荧光淬灭

设计合成了咔唑衍生物N-{3-[N,N-2(2-甲基吡啶)-胺甲基]苯基}咔唑.该化合物在溶液中具有很强的荧光并显示了对Zn2+和Cu2+选择性的荧光淬灭.实验和密度泛涵理论计算证实该化合物和金属离子形成了1∶1型配合物.合成的化合物可作为过渡金属离子Cu2+和Zn2+的化学荧光传感器.     

Na+-K+-ATP酶的π-演算语义及验证

给出了Na⁺-K⁺-ATP酶跨越细胞膜同时主动向胞内运转钾离子和向胞外运转钠离子这一生化过程的π-演算模型及该模型的Spin验证. 证明了用过程代数的方法表示以“相互通讯”和“可移动”为主要特征的生物系统并模拟其行为的可行性.      

Effect of MTEC1 on the functional expression of TCRaβ+ 3G11− 6C10− CD4+ CD8− thymocyte subset

A murine CD4⁺ thymocyte subset with phenotype of TCRαβ⁺ 3G11⁻ 6C10⁻ CD4⁺ CD8⁻ CD69^+/- HSA^med/lo contains the cells in relatively functional matured status. The functional property of the cells in this subset is characterized by the unique pattern of cytokine production at transitional stage from Th0 to Th2 type with the latter being the dominant type. After being co-cultured with murine thymic medullary epithelial cell line (MTEC1) cells, a murine thymic medullary type epithelial cell line, the TCRαβ⁺ 3G11⁻ 6C10⁻ CD4⁺ CD8⁻ CD69^+/- HSA^med/lo thymocytes, has exhibited significantly higher levels of proliferation capability and IL-6 production, whereas the production of IL-4 and IL-10 is suppressed after co-culturing with MTECl. By contrast, MTECl could not induce thymocytes to secrete Thl type of cytokines. The results suggest that MTECl can regulate functional status of this thymocyte subset and induce them to develop into a specialized Th2 subset.     

Effects of La3+ and Gd3+ on Ca2+ influx in rat hepatoma H-35 cells

Effects of La³⁺ and Gd³⁺ on Ca²⁺ influx were investigated in rat hepatoma H-35 cells by measuring the initial rate of⁴⁵Ca²⁺ uptake. It was found that the maximum initial rate of Ca²⁺ uptake was increased six-to ten-fold at low concentrations of La³⁺ and Gd³⁺. Kinetic analyses by measuring the initial rate of Ca²⁺ influx at different external Ca²⁺ concentrations indicated the existence of two intracellular exchangeable components in the basal Ca²⁺ system, with low and high affinities for Ca²⁺, and only one class of Ca²⁺ binding sites was observed in the La³⁺-or Gd³⁺-treated cells. For high affinity, La³⁺ and Gd³⁺ increased both kinetic parametersK _m andV _max of basai Ca²⁺ influx. La³⁺ and Gd³⁺ compete directly with Ca²⁺ for Ca²⁺ binding site for low affinity. The kinetics is competitive.     

Functional maturation of two murine medullary-type CD8SP thymocytes

TCRαβCD4-CD8+ thymocytes are heterogeneity. They may undergo phenotypic and functional maturation within thymic medulla. Medullary-type CD8SP thymocytes were divided into seven subsets based on phenotypic analysis, and their precursor-progeny relationship along with the differential pathway was also delineated. To further testify the validity of the maturation pathway, we purified 6C10-CD69+ cells representing the early stage and 6C10-Qa-2+ cells representing the later stage among medullary-type CD8SP thymocytes and compared their functional maturation levels. CD8+ T cells of spleen were used as the control. It is shown that there is no obvious difference of proliferation ability among these three subsets; however, intracytoplasmic cytokine assay shows that there is a hier archy of IFN-γ and TNFα secretion among these subsets, strikingly comparable to their phenotypic status among medullary type CD8SP thymocytes. The bioassays of IL-2 and IFN-γ in culture supernatant give the similar results.     

Export of particulate organic carbon estimated from234Th-238U disequilibria and its temporal variation in the South China Sea

Activities of²³⁴Th and nutrient concentrations in the upper 500 m water column were measured at a time-series station in the South China Sea over a time span of 12.3 d. Results showed a reduction of dissolved²³⁴Th and an overall increase of particulate²³⁴Th during the period. Meanwhile, activities of total²³⁴Th kept fairly constant, implying rapid transformation of²³⁴Th between the dissolved and particulate forms. Vertical profiles of total²³⁴Th showed evident deficit of²³⁴Th relative to²³⁸U in the upper 500 m water column. Using an irreversible steady-state model of thorium scavenging, export fluxes of particulate organic carbon (POC) corresponding to time pointsT ₁ andT ₂ were estimated to be 46.5 and 13.1 mmolC · m⁻² · d⁻¹. It was demonstrated that the estimation of POC export was greatly dependent on the POC/²³⁴Th_P ratios and the bias caused by the different models of²³⁴Th scavenging, however, was considered to be of minor importance.     

Oxygen isotopic (17O-18O) heterogeneity in Archaean continental nucleus, North China Craton

The oxygen isotopic data for amphibolites from Archaean continental nucleus, North China Craton indicate that ( i ) the evolving lines structured by the data are parallel to the geoselenic evolving line, which means that the parent materials of these continental nucleus originated from solar matter; ( ii ) different intercepts for these evolving lines manifest that oxygen isotopic compositions of different continental nucleus are heterogeneous, which means that these continental nucleuses originated from different parent resources with different original compositions.     

Determination of specific activity of230Th in uranium ore samples

A new method suitable for determining specific activity of²³⁰Th in uranium ore samples is built. The method is characterized by adding the²³⁰Th/²³²Th standard dilution agent with lower activity ratio (Its²³⁰Th/²³²Th activity ratio and²³⁰Th have been known) to the samples and using isotopic dilution analysis. The method can be applied to analyses of²³⁰Th specific activity in various²³⁰Th/²³²Th activity ratio samples. The precision can also be improved.     

Laser probe40Ar/39Ar dating of mica on the deformed rocks from Altyn Fault and its tectonic implications, western China

The samples of Caledonian mylonitized granite and Jurassic meta-sedimentary rocks were collected in the north of Dangjinshan Pass, Qaidam gate fault-valley and Gesi fault-valley. Detailed studies under the microscope and electronic microscope suggest that all the samples contain the syntectonic-growing minerals such as white mica, chlorite, sericite, biotite, etc. By dating these minerals, we got a group of ⁴⁰Ar/³⁹Ar laser probe isochronal ages of 89—92 Ma and apparent ages of (46.6±6.4) Ma. The ages ranging from 97 to 46 Ma were reported for the first time in the isotopic dating researches of the Altyn Fault. The isochronal age group of (98—89) Ma indicates that a ductile strike-slip event, with low-grade metamorphism, began in late Cretaceous. This suggests that the strike-slip movement of the Altyn Fault should be related to the formation of the so-called west tectonic syntaxis in the Nepal-western Kunlun area.     

Effect of fatty acids on polyamine contents and Na+/H+ antiport activity in PM vesicles isolated from roots of barley under salt stress

With 200 mmol/L NaCl treatment on barley cultivar “Jian 4” (Hordeum vulgare L. cv. J4) seedlings for 6 d, the contents of covalently and noncovalently conjugated polyamines (PAs) and activities of H⁺-ATPase in plasma membrane (PM) vesicles isolated from the roots decreased remarkably. Moreover, the activity of Na⁺/H⁺ antiport was detected first in PM vesicles. The results showed that the decrease in the contents of membrane phospholipid, noncovalently conjugated PAs and activity of H⁺-ATPase caused by NaCl could be restored partially by application of 1 mmol/L stearie acid (C_16:0) and linoleic acid (C_18:2), and C_18:2 was more effective than C_16:0 In addition, a reduction in the contents of covalently conjugated PAs was only reversed partially in the presence of C_18:2 Furthermore, Na⁺/H⁺ antiport activity was strengthened by exogenous C_16:0 and C_18:2 and C_18:2 was more effective than C_16:0. The correlative analysis suggested that, after application of C_16:0 and C_18:2 under salt stress, there was a significant positive correlation existing among phospholipid content, noncovalently conjugated PA levels, H⁺-ATPase activities and Na⁺/H⁺ antiport activities, indicating that one of the mitigative mechanisms of exogenous fatty acids on salt injury was to improve membrane phospholipid and PA contents, leading to an enhance in membrane integrity and a change in charge status of PM vesicles, so the activity of membrane-associated enzyme H⁺-ATPase was increased and synthesis of Na⁺/H⁺ antiport protein was activated.     

含Sr2+和Bi3+有机杂化体的合成及其光降解罗丹明B

采用溶剂热法在N,N-二甲基甲酰胺溶液中合成了不同摩尔比例的SrCl_2和Bi(NO_3)_3(分别为5%,10%,30%,50%,80%)与对苯二甲酸形成的含Sr~(2+)和Bi~(3+)有机杂化体,并在紫外可见光照射下对其进行了罗丹明B降解活性的评价.结果表明:杂化体在紫外可见光下对RhB降解活性良好,其中SrCl_2摩尔比例10%掺杂的催化剂光降解活性最佳,这归结于其在紫外区域对光有很好的吸收及光生电子和空穴能有效地分离.双金属离子能协同调节有机杂化体的光催化活性.