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火焰原子吸收法测定癌细胞中的钙、镁、铜等金属元素 总被引:2,自引:0,他引:2
采用火焰原子吸收法直接测定一系列(食道、胃)癌细胞及其近旁的正常细胞中的钙、镁、铜等金属含量。结果表明,钙的变异系数为1.83%-4.19%,回收率为99.8%-104.0%;镁的变异系数为0.02%~1.18%,回收率为97.2%-98.5%;铜的变异系数为3.80%-6.68%,回收率为90.5%~99.7%;均得到较满意的结果,具有一定的参考价值。 相似文献
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法呢基苯乙酮及其黄烷酮化合物的全合成 总被引:4,自引:0,他引:4
以2,4,6-三羟基苯乙酮和法呢基溴为原料,经一步反应以52.0%和6.5%的收率同时得到3-法呢基-2,4,6-三羟基苯乙酮(1)和4-法呢氧基-2,6-二羟基苯乙酮(2);然后以化合物1和3,4-二羟基苯甲醛为原料,经羟基保护、缩合、环化和去保护基共6步反应,以19.8%的总收率全合成了(±)-6-法呢基-3',4',5,7-四羟基黄烷酮(3).化合物1、2和3均是从澳大利亚植物Borroniaramosa中分离得到的新天然产物,此次为首次合成. 相似文献
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应用反相高效液相色潜法(RP-HPLC)对肽类药物促黄体激素释放激素(LHRH)、醋酸亮丙瑞林(Leuprorelin Acetate,TAP-144-SR)和新药LXT101在6种酶体系中的体外代谢性质进行了研究。流动相采用梯度或等度洗脱;LHRH、TAP-144-SR的检测波长为216nm,LXT101的检测波长为225nm。采用液相色谱-电喷雾质谱(LC-ESI-MS)联用技术对其酶解片段进行了鉴定。LHRH、TAP-144-SR和LXT101的浓度在4.0~400mg/L范围内与其峰面积呈良好线性关系(r〉0.9990);在糜蛋白酶、胰蛋白酶、胃蛋白酶和胰混合酶中的绝对回收率为95.0%~98.7%;在血浆和肝匀浆中的绝对回收率为60.0%~71.0%;日内相对标准偏差(RSD)〈1.5%,日间RSD〈2.5%;半衰期(t1/2)为LXT-101〉TAP-144-SR〉LHRH;质谱鉴定表明:LHRH容易在3-4、5-6位发生断裂,TAP-144-SR容易在3-4位发生断裂;选择的酶体系可用于评价多肽药物的体外代谢性质。 相似文献
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标准加入火焰原子吸收法测定钨及钨化合物中的钾、钠 总被引:4,自引:0,他引:4
在以钨为基体的溶液中,利用柠檬酸为掩蔽剂,氯化铯为消电离剂,应用火焰原子吸收法进行钨及钨化合物中钾、钠的测定,5次测定结果的极差值在0.0002%-0.0004%之间,K、Na的加标准回收率分别为98.0%-104.0%及96.4%-102.6%。本方法已应用于钨及钨化合物中钾、钠的测定。 相似文献
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特丁基二甲基硅烷衍生化-气相色谱-质谱联用法分析尿中硝西泮的代谢物7-氨基硝西泮 总被引:1,自引:0,他引:1
建立了用特丁基二甲基硅烷(TBDMS)衍生化-气相色谱-质谱联用分析尿中硝西泮的主要代谢物7-氨基硝西泮(7ANIZ)的高灵敏方法。方法的样品萃取率为83.6%;线性范围为10~500μg/L;检出限(LOD)为1μg/L;定量限(LOQ)为3μg/L;RSD为3.6%-5.8%,回收率为96.3%-102.6%。对口服10mg硝西泮者96h内所排泄的尿液进行了7ANIZ检测,结果表明:本方法能满足司法鉴定的要求。 相似文献
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用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%. 相似文献
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Uroš Grošelj Mojca Žorž Amalija Golobič Branko Stanovnik Jurij Svete 《Tetrahedron》2013,69(52):11092-11108
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives. 相似文献
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The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion. 相似文献
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The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula. 相似文献
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Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines. 相似文献
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N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%). 相似文献
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Shashikant U. Dighe Surya K. Samanta Shivalinga Kolle Sanjay Batra 《Tetrahedron》2017,73(17):2455-2467
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones. 相似文献
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In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates. 相似文献
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Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products. 相似文献
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