3,5-二(4-苯偶氮苯氨基重氮基)苯甲酸的合成及其与镍(Ⅱ)的显色反应

合成了一种新型的双三氮烯类显色剂3,5-二(4-苯偶氮苯氨基重氮基)苯甲酸(BPAAD),并对该试剂与Ni(Ⅱ)的显色反应进行了研究。实验表明,在Triton X-100存在下,pH10.0的硼砂-氢氧化钠缓冲溶液中,该试剂与Ni(Ⅱ)形成了2∶1的红色络合物,其最大吸收波长位于500 nm处,表观摩尔吸光系数ε为1.46×105L.mol-1.cm-1,25 mL溶液中,镍的浓度在0~0.8μg范围内遵守比尔定律。研究了测定铝合金中镍的各种条件和共存离子的影响,加入混合掩蔽剂后,可提高Al3+,Fe3+     

4-(4-氯苯重氮氨基)-4'-硝基偶氮苯的合成及其与镉(Ⅱ)的显色反应

合成了一种新显色剂4-(4-氯苯重氮氨基)-4'-硝基偶氮苯(简称CDANA),并研究了该试剂与Cd(Ⅱ)的高灵敏显色反应。在60~65℃温度下,亚硫酸氢钠与甲醛反应半小时之后滴入苯胺生成苯胺基甲基磺酸钠,另将硝基苯胺重氮化得到重氮盐溶液滴入苯胺基甲基磺酸钠中得到4'-硝基-4-氨基偶氮苯,然后将其滴入氯苯胺重氮化后的重氮盐溶液中,得经红外光谱检验和元素分析证实的目标产物。分光光度的研究结果表明,在Triton X-100存在下,于pH 10.5的Na2B4O7-NaOH缓冲介质中,镉(Ⅱ)与试剂形成1∶2的橙红色络合物,其最大吸收波长位于558 nm处,表观摩尔吸光系数为1.42×105L.mol-1.cm-1,镉(Ⅱ)的质量浓度在0~0.75μg/mL范围内服从比尔定律。所拟方法用于废水中微量镉的直接测定,结果与原子吸收光谱法一致。     

4-(4-甲基苯磺酰胺基)嘧啶类化合物的合成及除草活性

对甲苯磺酰胺与2,4-二氯嘧啶在氢化钠作敷酸剂,N,N-二甲基乙酰胺作溶剂的条件下反应,合成了2-氯-4-(4-甲基苯磺酰胺基)嘧啶.2-氯-4-(4-甲基苯磺酰胺基)嘧啶再与甲醇钠反应,合成了2-甲氧基-4-(4-甲基苯磺酰胺基)嘧啶.所合成的目标化合物均通过1H-NMR和元素分析确证.生物活性测试结果表明,4-(4-甲基苯磺酰胺基)嘧啶类化合物有一定的除草活性,2-氯-4-(4-甲基苯磺酰胺基)嘧啶浓度100 μg/ml时对油菜根长生长具有较好的抑制效果.     

1,3-二(4-硝基苯氨基重氮)苯的合成及其与镍Ⅱ的显色反应

合成了一种新型的双三氮烯类显色剂1,3-二(4-硝基苯氨基重氮)苯,并对该试剂与Ni2+的显色反应进行了研究。实验表明,在Triton X-100存在下,pH 10.6的硼砂-氢氧化钠缓冲溶液中,该试剂与NiⅡ(形成了3∶1的红色络合物,其最大吸收波长位于480nm处,表观摩尔吸光系数ε为2.15×105L.mol-1.cm-1,Ni2+的质量浓度在0~0.64mg/L范围内遵守比尔定律。试剂用于分光光度测定铝合金标样中镍,测定值与认定值相符。     

1-(5-硝基-3-苯并异噻唑)-3-[4-(苯基偶氮)苯基]- 三氮烯的合成及与钴(Ⅱ)的显色反应

合成了新显色剂1-(5-硝基-3-苯并异噻唑)-3-[4-(苯基偶氮)苯基]-三氮烯(NBPT-PAPT),并研究了该试剂在非离子表面活性剂Tween-80存在下与钴的显色反应。在pH10.54的Na2B4O7-NaOH缓冲溶液介质中,钴与该试剂形成摩尔比为1∶2的黄绿色络合物,其表观摩尔吸光系数ε=1.22×105L.mol-1.cm-1,钴在0～240μg/L范围内符合比尔定律。用双峰双波长光度法测定了水样中微量钴,结果满意。     

4-(3,5-二溴-2-吡啶重氮氨基)-4'-硝基偶氮苯的合成及其与镉(Ⅱ)显色反应的研究

合成了新显色剂4-(3,5-二溴-2-吡啶重氮氨基)-4'-硝基偶氮苯(简称DBPNAB),研究了在非离子表面活性剂Triton X-100存在下其与Cd(Ⅱ)的显色反应.结果表明,在pH 10.2的Na2B4O7-NaOH缓冲介质中,该试剂与Cd(Ⅱ)形成摩尔比为2:1的红色络合物,最大吸收波长位于581 nm,表观摩尔吸光系数为1.61×105L·mol-1·cm-1,镉的质量浓度在0～0.7μg/mL范围内遵守比尔定律.所拟方法用于废水中微量镉(Ⅱ)的直接测定,相对标准偏差为2.0%～3.3%,回收率为97.4%～103.6%.     

4-(5-硝基-2-吡啶偶氮)-1,3-二氨基苯的合成及其与钴的显色反应

合成并鉴定了一种新试剂4-(5-硝基-2-吡啶偶氮)-1,3-二氨基苯(5-NO2-PADAB),研究了该试剂与钴(Ⅱ)的显色反应,并建立了一个测定钴的光度分析新方法.结果表明,在pH 6.2～8.0范围内,钴(Ⅱ)与试剂形成紫红色络合物.钴络合物形成后即非常稳定,加入强酸酸化,由于质子化作用,络合物的颜色加深,吸收波长红移,在2.9～6.1 mol/L H2SO4介质中,最大吸收波长红移到580 nm,表观摩尔吸光系数为1.34×106 L·mol-1·cm-1.钴浓度在0～0.48 mg/L范围内符合比尔定律.方法已用于矿样中微量钴的测定,结果与火焰原子吸收光谱法测定结果相一致,相对标准偏差为1.68%.     

4-(3,5-二溴-2-吡啶重氮氨基)-4′-硝基偶氮苯的合成及其与镉(Ⅱ)显色反应的研究

合成了新显色剂4-(3,5-二溴-2-吡啶重氮氨基)-4′-硝基偶氮苯(简称DBPNAB),研究了在非离子表面活性剂Triton X-100存在下其与Cd(Ⅱ)的显色反应。结果表明,在pH10.2的Na2B4O7-NaOH缓冲介质中,该试剂与Cd(Ⅱ)形成摩尔比为2∶1的红色络合物,最大吸收波长位于581 nm,表观摩尔吸光系数为1.61×105L.mol-1.cm-1,镉的质量浓度在0～0.7μg/mL范围内遵守比尔定律。所拟方法用于废水中微量镉(Ⅱ)的直接测定,相对标准偏差为2.0%～3.3%,回收率为97.4%～103.6%。     

2-[(对-苯偶氮苯)-三氮烯]苯甲酸与锑的显色反应研究及其应用

合成了新显色剂2-[(对-苯偶氮苯)-三氮烯]苯甲酸(PABTB),并研究了该试剂在阳离子表面活性剂CTMAB存在下与锑离子的显色反应。将邻氨基苯甲酸重氮化得到重氮盐溶液,然后重氮盐与对氨基苯偶氮苯发生偶联反应,产物经提纯和重结晶后得到PABTB。通过元素分析和红外光谱检验确认其为目标产物。在pH 10.18的硼砂和氢氧化钠缓冲溶液介质中,锑与该试剂形成摩尔比为1∶2的红色络合物,其表观摩尔吸光系数为1.686×105L.mol-1.cm-1,锑离子的浓度在0~0.7 mg/L范围内符合比尔定律。用该试剂成功地测定了矿样中微量锑。     

1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯的合成及其与汞(Ⅱ)的显色反应

合成并鉴定了一种新三氮烯试剂1-(4-安替比林)-3-(2-苯并噻唑)-三氮烯(ABTTA),研究了该试剂与Hg2 的显色反应条件,并建立了一个测定汞的光度分析新方法。在溴化十六烷基三甲铵(CTMAB)存在下,试剂与汞在pH11.0Na2B4O7-NaOH缓冲溶液中迅速生成褐色络合物,其最大吸收波长为480nm。在最佳实验条件下,体系在480nm处的表观摩尔吸光系数为5.46×104L.mol-1.cm-1,25mL溶液中Hg2 的质量在5.0~70.0μg范围内符合比尔定律。对20多种共存离子的影响进行试验,结果表明,大多数常见离子不干扰测定。本方法虽然灵敏度不高,但线性范围宽、选择性较好,用于环境水样中汞的测定,结果满意。     

Simultaneous determination of polyamines, N-acetylated polyamines and the polyamine analogues BE-3-3-3 and BE-4-4-4-4 by capillary gas chromatography with nitrogen-phosphorus detection

IgM paraproteins from patients with CANOMAD (chronic ataxic neuropathy, ophthalmoplegia, M-protein, agglutination, anti-disialosyl antibodies) react with NeuAc(alpha 2-8)NeuAc epitopes on a wide range of gangliosides including GQ1b, GT1a, GD1b and GD3. The tissue distribution of reactive antigens in human peripheral nerve has not been addressed in detail. In addition, the origin of these antibodies is unknown. Here we report that purified anti-disialosyl paraproteins from two affected patients bind a wide array of human peripheral nerve structures including dorsal root ganglia, dorsal and ventral root axons, femoral and oculomotor nerves. We also show that these paraproteins bind lipopolysaccharides of Campylobacter jejuni isolates from 3/3 cases of Miller Fisher syndrome, and to a less frequent extent, from cases of Guillain-Barré syndrome and enteritis controls. In conjunction with our previous studies, these data provide a possible causal link between the origin and pathogenic effects of anti-disialosyl antibodies in human paraproteinaemic neuropathy.     

(3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1-yl]chroman-4,7-diol: a conformationally restricted analogue of the NR2B subtype-selective NMDA antagonist (1S,2S)-1-(4-hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)- 1-propanol

(1S,2S)-1-(4-Hydroxyphenyl)-2-(4-hydroxy-4-phenylpiperidino)-1-propanol (CP-101,606, 1) is a recently described antagonist of N-methyl-D-aspartate (NMDA) receptors containing the NR2B subunit. In the present study, the optimal orientation of compounds of this structural type for their receptor was explored. Tethering of the pendent methyl group of 1 to the phenolic aromatic ring via an oxygen atom prevents rotation about the central portion of the molecule. Several of the new chromanol compounds have high affinity for the racemic [3H]CP-101,606 binding site on the NMDA receptor and protect against glutamate toxicity in cultured hippocampal neurons. The new ring caused a change in the stereochemical preference of the receptor-cis (erythro) compounds had better affinity for the receptor than the trans isomers. Computational studies suggest that steric interactions between the pendent methyl group and the phenol ring in the acyclic series determine which structures can best fit the receptor. The chromanol analogue, (3R,4S)-3-[4-(4-fluorophenyl)-4-hydroxypiperidin-1- yl]chroman-4,7-diol (12a, CP-283,097), was found to possess potency and selectivity comparable to CP-101,606. Thus 12a is a new tool to explore the function of the NR2B-containing NMDA receptors.     

汽车青铜QSn4—42．5板材的试制

本文依据国内某用户的要求，对QSn4-4-2.5板材生产锭坯的熔铸工艺和加工工艺进行探索，并论述了该合金板材生产的工艺制度对期产品的性能的影响。     

HV—4B分析仪的应用

本文介绍ＨＶ－４Ｂ型微机碳硫分析仪与ＨＢ－２Ｂ型高引燃炉配套使用,在分析测定钢铁中的碳、硫元素时取代传统的非水－碘量滴定法,针对传统的化学分析法存在的问题,进行分析,改造,引进了高速仪器分析法,并取得了较好的效果。     

Dual inhibition of human type 4 phosphodiesterase isostates by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3- methyl-1-pyrrolidinecarboxylate

Purified recombinant human type 4 phosphodiesterase B2B (HSPDE4B2B) exists in both a low- and a high-affinity state that bind (R)-rolipram with Kd's of ca. 500 and 1 nM, respectively [Rocque, W. J., Tian, G., Wiseman, J. S., Holmes, W. D., Thompson, I. Z., Willard, D. H., Patel, I. R., Wisely, G. B., Clay, W. C., Kadwell, S. H., Hoffman, C. R., and Luther, M. A. (1997) Biochemistry 36, 14250-14261]. Since the tissue distribution of the two isostates may be significantly different, development of inhibitors that effectively inhibit both forms may be advantageous pharmacologically. In this study, enzyme inhibition and binding of HSPDE4B2B by (R, R)-(+/-)-methyl 3-acetyl-4-[3-(cyclopentyloxy)-4-methoxyphenyl]-3-methyl-1-pyrrolidin ecarboxylate (1), a novel inhibitor of phosphodiesterase 4 (PDE 4), were investigated. Binding experiments demonstrated high-affinity binding of 1 to HSPDE4B2B with a stoichiometry of 1:1. Inhibition of PDE activity showed only a single transition with an observed Ki similar to the apparent Kd determined by the binding experiments. Deletional mutants of HSPDE4B2B, which have been shown to bind (R)-rolipram with low affinity, were shown to interact with 1 with high affinity, indistinguishable from the results obtained with the full-length enzyme. Bound 1 was completely displaced by (R)-rolipram, and the displacement showed a biphasic transition that resembles the biphasic inhibition of HSPDE4B2B by (R)-rolipram. Theoretical analysis of the two transitions exemplified in the interaction of (R)-rolipram with HSPDE4B2B indicated that the two isostates were nonexchangeable. Phosphorylation at serines 487 and 489 on HSPDE4B2B had no effect on the stoichiometry of binding, the affinity for binding, or the inhibition of the enzyme by 1. These data further illustrate the presence of two isostates in PDE 4 as shown previously for (R)-rolipram binding and inhibition. In contrast to (R)-rolipram, where only one of the two isostates of PDE 4 binds with high affinity, 1 is a potent, dual inhibitor of both of the isostates of PDE 4. Kinetic and thermodynamic models describing the interactions between the nonexchangeable isostates of PDE 4 and its ligands are discussed.     

N-[4-(1,1''-biphenyl)methyl]-4-(4-thiomorpholinylmethyl) benzenamines as non-oxazolidinone analogues of antimycobacterial U-100480

Twenty-three patients underwent conventional arteriography and 3D contrast enhanced magnetic resonance angiography explorations. The study was limited to the iliofemoral arteries (13 segments for each patient). Each segment was classified as having 0-49%, 50-99% or 100% stenosis. Overall results were excellent with K = 0.822, sensitivity 92% and specificity 93%. Segment by segment analysis corroborated the overall results except for the internal iliac arteries and the deep femoral arteries, demonstrating the limitations of this technique in this series.     

特种铸造方式下QAl10-4-4铝青铜组织演变规律

采用OM、XRD、EDS及宏观硬度测试等手段研究了真空吸铸和离心铸造方式下QAl10-4-4铝青铜的组织演变规律。结果表明,两种铸造方式下组织中相的种类、析出顺序及初始析出温度有较大的不同。真空吸铸条件下,接近铸态的组织由α相、β’相、KⅡ和KⅢ相构成,其相的析出顺序为KⅡ→α→KⅢ;离心铸造条件下,接近铸态的组织中还含有KⅠ和KⅣ相,其相的析出顺序为α+KⅠ→KⅡ→KⅣ→KⅢ,对应的相初始析出温度整体高于真空吸铸,且α相的初始析出温度远高于真空吸铸。KⅠ相的析出与合金中Fe的含量及Fe/Ni值有关,两者越高,越容易析出KⅠ相。两种铸造方式下,随着淬火温度的降低,合金的硬度在整体上均呈现先快速降低后趋于稳定的趋势。但是,真空吸铸样品在淬火温度大于900℃时出现脆化。β→α+KⅢ共析分解对合金的硬度无明显影响。     

1-(2,6-二氯-4-硝基苯)-3-(4-硝基苯)-三氮烯分光光度法测定钴

研究了新试剂1-(2,6-二氯-4-硝基苯)-3-(-4-硝基苯)-三氮烯(DCNPNPT)与钴(Ⅱ)显色反应的适宜条件.在表面活性剂Triton X-100存在下,Na2B4O7-NaOH缓冲液(pH.9.3)介质中,钴(Ⅱ)与DCNPNPT形成黄色络合物(12),其最大吸收波长为545nm,用双峰双波长法测定络合物的表观摩尔吸光系数ε=1.08×105,钴在0～240μg/L范围内符合比尔定律.此法已用于VB12针剂和矿样中微量钴(Ⅱ)的测定,结果满意.