Synthesis and biodistribution of 99mTcN(PDTC)2as a potential brain imaging agent

The preparation of the bis(N-propyl dithiocarbamato) nitrido technetium-99m complex ^99mTcN(PDTC)₂ (PDTC: N-propyl dithiocarbamato) was carried out as a freeze-dried formulation, through a simple procedure involving the initial of ^99mTcO_4- with succinic dihydrazide in the presence of stannous chloride as reducing agent and propylenediamine tetraacetic acid (PDTA) as complexant, followed by the addition of the ligand sodium salt of N-propyl dithiocarbamate to afford the final product. The radiochemical purity of the complex was over 90%, as measured by thin layer chromatography. No decomposition of the complex at room temperature was observed over a period of 12 hours. Its partition coefficient indicated that it was a good lipophilic complex. Biodistribution in mice showed that the complex accumulated in the brain with high uptake. The brain uptake (ID%/g) was 5.07 and the brain/blood ratio 1.34 at 5-minute post-injection. This suggested a potential usefulness of the complex as a brain perfusion imaging agent. This revised version was published online in July 2006 with corrections to the Cover Date.     

ZnS胶体溶液中某些无机盐光化学过程中产生的阴离子自由基的ESR研究

本文用自旋捕捉与ＥＳＲ技术相结合的方法研究了ＺｎＳ胶体溶液中某些无机盐光化学过程中产生的无机阴离子自由基，并对自由基产生的机理进行了讨论     

The Synthesis of Gracillin and Dioscin：TWO Typical Representatives of Spirostanol Glycosides

Two spirostanol saponins(gracillin and dioscin)which have the typical sugar moieties were synthesized facilely by a general approach.     

反相悬浮聚合法合成超强吸水剂

以两性高分子作悬浮稳定剂，用反相悬浮聚合法合成了聚（丙烯酸盐－丙烯酰胺）类超强吸水剂．研究了交联剂、稳定剂、引发剂等用量、中和程度、单体组成及链转移剂等聚合条件对吸水剂吸水性能的影响．得到了吸蒸馏水１０５０ｍＬ／ｇ及吸０．９％ＮａＣｌ溶液８６ｍＬ／ｇ的超强吸水剂．此外，还比较了含不同反离子的聚丙烯酸类吸水剂的吸水性能     

Application of preparative high-speed counter-current chromatography for separation of methyl gallate from Acer truncatum Bunge

Preparative separation of methyl gallate in leaves extract of Acer truncatum Bunge was conducted using high-speed counter-current chromatography (HSCCC) with a solvent system composed of ethyl acetate-ethanol-water at volume ratios of 5:1:5 (v/v/v). In a single operation, 57.5 mg of methyl gallate was obtained from 120 mg of the extract. HPLC analyses of the counter-current chromatography (CCC) fraction revealed that the methyl gallate was having over 97% purity. Its structure was identified by 1H NMR and 13C NMR.     

Use of k0 concept to corrections for interferences from fissionable nuclides in reactor NAA

A neutron spectrum-independent compound nuclear constant, Ik_o, is proposed for fission interference corrections in reactor NAA by parametric method. Ik₀ values for eight major fission interference cases, belonging to three different types, have been determined in six irradiation positions (with _th/ _e 13,7–134) of three research reactors in our Institute. The general agreement among experimental Ik₀ 's from different irradiation positions and between experimental and calculated Ik₀ values for the same interference case verifies the validity of the method. Calculated Ik₀ values for all the possible fission interferences are tabulated. Interferences from²³⁸U(n,) and²³²Th(n,) reactions and reactor fast neutron induced²³⁸U(n, f) and²³²Th(n, f) reactions are discussed.     

Synthesis and Crystal Structure of Organocobalt(III) Complexes with Secondary Alkyls or Bulky Schiff Base Equatorial Ligands

Alkylcobalt(III) Schiff base B(12) model complexes with secondary alkyls or a bulky diamine in the equatorial position were synthesized and characterized. Structures have been first determined by X-ray diffraction analysis for i-C(4)H(9)Co(salen)(gamma-pic) (I), n-C(3)H(7)Co(salen)(gamma-pic) (II) and C(2)H(5)Co(SB) (III), where salen = N,N'-ethylenebis(salicylideneamine) dianion; SB = 1,1,2,2-tetramethyl-N,N'-ethylenebis(salicylideneamine) dianion, gamma-pic = gamma-picoline. Crystal data for I (CoC(26)N(3)O(2)H(30)): space group P2(1)/c with a = 6.661(5) ?, b = 18.612(2) ?, c = 19.533(3) ?, beta = 98.93(1) degrees, V = 2392.10 ?(3), D(calcd) = 1.320 g.cm(-3), Z = 4, and R = 0.048 for 4469 measured reflections. Crystal data for II (CoC(25)N(3)O(2)H(28)): space group P2(1)/c, a = 9.609(6) ?, b = 19.169(8) ?, c = 12.995(9) ?, beta = 106.9(7) degrees, V = 2290.4 ?(3), D(calcd) = 1.332 g.cm(-1), Z = 4, and R = 0.048 for 4358 measured reflections. Crystal data for III (CoC(22)N(2)O(2)H(27)): space group P2(1)/c, a = 8.318(3) ?, b = 21.579(2) ?, c = 11.572(2) ?, beta = 93.35(1) degrees, V = 2073.7 ?(3), D(calcd) = 1.314 g.cm(-1), Z = 4, and R = 0.060 for 3954 measured reflections. The crystal structure data reveal that complexes I and II display six-coordinate octahedral geometry; their Co-C, Co-N bond lengths, as well as the Co-C-C angles, are very close to those in 5'-deoxyadenosylcobalamin. Complex III is one of the very few compounds having five-coordinate square pyramidal geometry and observed instability of the Co-C bond.     

邻氨基酚电聚合膜的研究

在酸性溶液中, 邻氨基酚(OAP)可电聚合成均匀的活性聚邻氮基酚膜(POAP), 膜有致密结构和“张开”结构。POAP膜的主要结构形式为: 与Ni~(2+)络合后, 形成POAP—Ni~(2+)膜, 其主要结构形式为:     

DNAzyme amplification of molecular beacon signal

This paper reports an improved catalytic molecular beacon. Addition of the target oligonucleotide activates a DNA enzyme (DNAzyme), which, in turn, activates multiple copies of molecular beacons (MB) and gives rise to a strong fluorescence signal. In a previous design, the activated DNAzyme could oligomerize, especially dimerize, and result in inactivation of the DNAzyme. The current design avoids this problem, upon activated by the target DNA, the DNAzyme will stay constantly active. With the improved method, a detection of 10 pM DNA has been demonstrated, which is 1000 times more sensitive than the method previously reported.