CdS量子点的制备及细胞膜初步荧光标记

以巯基乙酸为稳定剂,通过控制反应温度、反应时间及pH值,在水相中合成了稳定的受激发出紫光、蓝光、绿光、黄光和红光的CdS量子点;通过紫外可见吸收光谱、荧光光谱和X射线衍射谱(XRD)对产物的光学性能和晶体结构进行了表征,结果表明所合成的CdS量子点分散性较好,量子产率为8%,为立方晶型,粒径约1 nm;利用荧光倒置显微镜观察了量子点在洋葱内表皮细胞膜上聚集及受激发射荧光行为,实现细胞膜初步标记.     

Competitive kinetic processes in the thermal rearrangement of 1,1-difluoro-2-(dideuteriomethylene)-cyclopropane

The synthesis of 1,1-difluoro-2-(dideuteriomethylene)-cyclopropane is reported along with the kinetics of its competing, reversible, first order rearrangements: (a) the degenerate rearrangement to 1,1-difluoro-3,3-dideuterio-2-methylene-cyclopropane, and (b) its rearrangement to 2,2-dideuterio-1-(difluoromethylene)-cyclopropane. The observed experimental ratio of these two rate constants, 2.3, is consistent with Borden's theoretically predicted ratio of 3.     

A novel approach to determination of carbonyl groups in DMAc/LiCl-insoluble pulps by fluorescence labeling

The CCOA method for profiling of carbonyl groups by fluorescence labeling has meanwhile become an established procedure for dissolving pulps and rag papers. High molecular weight pulps, such as certain paper pulps, could not be analyzed so far due to their limited solubility in DMAc/LiCl. The new approach presented in this paper is based on the heterogeneous carbonyl-selective fluorescence labeling with CCOA (2), which is subsequently released with triflic acid from the labeled pulp in a quantitative manner, and the concentration of CCOA and CCOA-derived products is determined by HPLC. The procedure requires material in the mg range only. Calibration was performed against DMAc/LiCl-soluble standard pulps. Comparison of the data obtained by the novel approach correlated well with data from the established CCOA procedure.     

Photo-labeling of C60 with 3-trifluoromethyl-3-phenyldiazirine

The photochemical reaction of C₆₀ with 3-trifluoromethyl-3-phenyldiazirine affords a photo-labeled C₆₀ derivative. The derivative was characterized by mass, UV-vis absorption, NMR spectroscopy, and X-ray crystallographic analysis. The redox potentials of this derivative were also investigated by means of CV and DPV. This photo-labeling method to the fullerene surface is expected to be effective for constructing various kinds of bio-functionalized fullerenes.     

Reduction of 2,2,2-trifluoro-1-arylethanones with alkyl phosphines

In the presence of alkyl phosphines, reduction of 2,2,2-trifluoro-1-arylethanones proceeded smoothly to give the corresponding reduction products in moderate to high yields at room temperature. The possible mechanism was discussed on the basis of deuterium labeling and control experiments, indicating that one hydrogen transfer took place from alkyl phosphine to the carbonyl group activated by a strongly electron-withdrawing trifluoromethyl group.     

Investigation of the species-dependent in vitro metabolism of BAL30630 by stable isotope labeling and isotope exchange experiments analyzed by capillary liquid chromatography coupled to mass spectrometry

The in vitro metabolic profile of BAL30630, an antifungal piperazine propanol derivative, which inhibits the 1,3-beta-d-glucansynthase, was investigated by incubation with microsomes of several species and with rat hepatocytes. For the spotting of the metabolites, mixtures of BAL30630 with a stable isotope (deuterium) labeled analogue were incubated. The metabolic pattern comprises several oxidized metabolites. Based on isotope exchange experiments, their structures could be assigned to epoxide- and hydroxylated metabolites. In hepatocyte incubations, several glucuronides formed from these oxidized metabolites could be observed. From the analysis of the metabolic pattern in microsomes, products of carbamate hydrolysis were characterized. This hydrolysis was highly species dependent. In activated incubations and in rat hepatocytes, those metabolites were further oxidized. In incubations without NADPH activation, the resulting hydrolytic metabolites could be enriched without the subsequent oxidation. Final structural elucidation of the metabolites was performed using accurate mass determination and isotope exchange experiments, in which incubations were analyzed by deuterium exchange and capillary HPLC–QTof-MS and MS/MS. The use of non-radioactive, stabile isotope labeled drug analogues in combination with isotope exchange studies was essential in particular for a defined assignment of the functional groups in the structures of the investigated metabolites.     

On super edge-antimagic total labelings of

A graph G of order p and size q is called (a,d)-edge-antimagic total if there exists a bijective function f:V(G)E(G)→{1,2,…,p+q} such that the edge-weights w(uv)=f(u)+f(v)+f(uv), uvE(G), form an arithmetic sequence with first term a and common difference d. The graph G is said to be super (a,d)-edge-antimagic total if the vertex labels are 1,2,…,p. In this paper we study super (a,d)-edge-antimagic properties of mK_n, that is, of the graph formed by the disjoint union of m copies of K_n.     

A physical pathway to understand individual's labeling behavior in signed social networks

In this paper we propose a reshuffling approach to empirical analyze individual's labeling behavior in signed social networks. In our approach, each individual is assumed to have the ability to re-label his/her neighbors randomly with the parameters $p_s$ and $p_{+}$. Many reshuffled networks, which have the same topological structure and different signs' configuration, are built through applying our approach to the given three signed social networks. The entropy $S_{out}$ and the giant component ${\rho }_G$ for each reshuffled networks are calculated and analyzed. We find that there exist two kinds of individual's labeling behavior according to the suppressed effect of $S_{out}$ and the exponent α in the relationship of ${\rho }_G$ and $q_{+}$. Additionally, the suppressed effect of $S_{out}$ shows the non-randomness factor in individual's labeling behavior. These results offer new insights to understand human's behavior in online social networks.     

三羰基锝配体基苯基甲磺酰胺的合成与表征

以2-氨基-5-硝基苯酚为原料经过酚羟基烷基化、氨基甲磺酰化、硝基还原为氨基后,进行溴乙酰化以及N-烷基化5步反应制得了三羰基锝标记配体基：N-[2-环己基甲氧基-4(1-(2,2′-二吡啶甲基)胺基)乙酰胺基]苯基甲磺酰胺(NSC-PA),并对反应条件进行了优化。 中间体及目标化合物经红外、质谱和核磁共振氢谱进行了结构表征,HPLC法测定最终产物的纯度大于98%。 该目标化合物可以作为三羰基锝标记前体,为进一步开发乳腺癌显像药物奠定了基础。