共查询到18条相似文献,搜索用时 156 毫秒
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头发中内源性类固醇激素的气相色谱-串联质谱分析 总被引:3,自引:1,他引:2
建立了建康人头发中内源性类固醇兴奋剂睾酮、表睾酮、雄酮、苯胆烷醇酮和脱氢表雄酮的气相色谱-串联质谱(GC-MS/MS)分析方法。头发经碱水解后,以乙醚提取,经衍生化后采用GC-MS/MS的多反应监测模式(MRM)分析。方法的线性关系良好,检出限达0.1~0.2 pg/mg;提取回收率为74.6%~104.5%;日内测定的准确度为90.1%~113.7%,日内及日间测定的精密度均小于17.5%。应用所建立的方法测定了80例中国健康人头发中睾酮、表睾酮、雄酮、苯胆烷醇酮和脱氢表雄酮的生理水平,为内源性类固醇兴奋剂滥用的判断提供了方法和基础数据。 相似文献
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基因兴奋剂是指以非治疗目的而向运动员体内导入外源基因或细胞等物质,以不正当方法提高运动员成绩的物质或技术。目前随着基因治疗技术的发展,基因兴奋剂被用于竞技体育赛场的潜在问题受到越来越密切的关注,因此对基因兴奋剂检测方法的需求也愈发迫切。本文简要介绍了基因兴奋剂的潜在候选基因、导入途径与载体、基因兴奋剂的危害以及已有基因兴奋剂的检测方法,并对未来基因兴奋剂检测领域急需解决的关键问题进行了讨论。 相似文献
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细胞内原位信号放大策略是检测低丰度内源性目标物的有效手段, 但多数信号放大策略依赖于外源性辅助物, 不可避免地改变细胞内微环境, 进而对机体造成一定干扰. 针对此问题, 可利用细胞内源性物质(如金属离子、 核酸、 蛋白酶等)实现原位荧光信号放大, 对不同生物标志物进行荧光成像, 此方法对低丰度靶分子检测及成像具有重要意义. 本文对内源性物质辅助信号放大及细胞内荧光成像相关研究进行了归纳整理, 介绍了内源性核酸、 酶、 蛋白质、 三磷酸腺苷(ATP)和金属离子辅助信号放大策略, 并探讨了其信号放大机理; 总结了内源性物质辅助信号放大探针在低丰度物质检测及成像方面的研究进展; 最后展望了该策略在细胞成像方面的优势及应用前景. 相似文献
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睾酮甲醇溶液标准物质的定值及不确定度评定 总被引:1,自引:0,他引:1
针对目前食品中兴奋剂类药物检测的需求,研制了睾酮甲醇溶液国家级标准物质。通过对经筛选的市售原料纯品进行液相色谱-质谱(LC-MS)和红外光谱(IR)定性分析后,利用高效液相色谱法(HPLC)对睾酮蛋白同化类固醇类兴奋剂原料进行纯度定值。利用HPLC在244nm监测,0.1%HAc-乙腈(50∶50,体积比)作为流动相进行等度洗脱,以Inertsil ODS-SP(250mm×4.6mm,5μm)进行分离,测得液相条件下睾酮固体的纯度为99.89%。为保证纯度测量的准确性,采用多家联合定值对睾酮的纯度进行检验。睾酮溶液标准物质经重量-重量法配制后,进行均匀性和稳定性实验,浓度赋值后进行不确定度评定。研制的睾酮溶液标准物质目前已被批准为国家二级标准物质并应用于实际检测。 相似文献
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Anapyrexia, which is a regulated fall in core temperature, is beneficial for animals and humans when the oxygen supply is limited, e.g., hypoxic, ischemic, or histotoxic hypoxia, since at low body temperature the tissues require less oxygen due to Q(10). Besides hypoxia, anapyrexia can be induced various exogenous and endogenous substances, named cryogens. However, there are only a few reports investigating endogenous cryogens in mammals. We have experienced one patient who suffered from severe hypothermia. The patient seemed to be excessively producing endogenous peptidergic cryogenic substances the molecular weight of which may be greater than 30 kDa. In animal studies, the patient's cryogen appeared to affect metabolic functions, including thermogenic threshold temperatures, and then to produce hypothermia. Since endogenous cryogenic substances may be regarded as useful tool in human activities, e.g., during brain hypothermia therapy or staying in a space station or spaceship, further studies may be needed to identify human endogenous cryogens. 相似文献
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采用顶空固相微萃取―气相色谱质谱联用(HS-SPME-GC-MS)的方法比较广东省内番禺产和连南产柠檬的果肉中挥发性风味物质的异同。实验采用7μmPDMS(聚二甲基硅氧烷)的萃取头进行吸附。气相色谱分析采用DB-5MS气相色谱柱,柱温采取程序升温,进样口温度250℃,分流比20∶1。质谱采用EI源为离子源,电子能量70 eV,离子源温度200℃;接口温度230℃。结果表明,番禺柠檬和连南柠檬果肉中的主要风味物质均为D-柠檬烯,但连南柠檬中风味物质的种类更多,这可能是连南柠檬香气更为浓郁的原因之一。 相似文献
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Maxie Kohler Klaus Püschel Dimitri Sakharov Alexander Tonevitskiy Wilhelm Schänzer Mario Thevis 《Electrophoresis》2008,29(22):4495-4502
Human growth hormone (GH) has several central metabolic functions including bone growth in childhood, and its anabolic and lipolytic effects in particular are assumed reasons for the abuse of GH by athletes. Human endogenous GH consists of a main 22 kDa variant and several isoforms. In contrast, recombinant GH consists of only one variant being identical to the main endogenous isoform. The method presented here separates different isoforms by 2‐D PAGE after isolation of GH from plasma using an immunoaffinity purification system. While samples containing endogenous GH yield up to four isoforms, samples with recombinant GH contain the main 22 kDa spot only. Normalized spot volumes (NSV) are calculated after addition of an internal standard and a discrimination limit was determined at 0.52 for the NSV of the main 22 kDa spot. Above this value, samples containing endogenous GH show at least the main 22 kDa isoform and the 20 kDa splice variant. In contrast, samples with a NSV >0.52 and only one spot are suspicious to contain recombinant GH. This method detects discrete isoforms of GH from plasma and discriminates endogenous GH from its recombinant analog, which makes it useful for doping control purposes. 相似文献
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From the self-assembly of the typical Salen-type Schiff-base ligand H2L and Zn(OAc)2·2H2O in the molar ratio of 1:1 or 1:2, the mononuclear [Zn(L)(H2O)](1) or binuclear [Zn2(L)(OAc)2(H2O)](2) are obtained, respectively. For both complexes 1 and 2, the unsaturated five-coordinate coordination environment to the catalytic active centers(Zn2+ ions) permits the monomer insertion for the effective solution copolymerization of cyclohexene oxide and maleic anhydride. All the solution copolymerizations afford poly(ester-co-ether)s, while lower catalyst and co-catalyst concentrations are helpful for the formation of alternating polyester. Of the three co-catalysts, 4-(dimethylamino)pyridine is found to be the most efficient, while an excess thereof is detrimental for chain growth of the copolymers. 相似文献
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In late 2019, a global pandemic occurred. The causative agent was identified as a member of the Coronaviridae family, called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we present an analysis on the substances identified in the human metabolome capable of binding the active site of the SARS-CoV-2 main protease (Mpro). The substances present in the human metabolome have both endogenous and exogenous origins. The aim of this research was to find molecules whose biochemical and toxicological profile was known that could be the starting point for the development of antiviral therapies. Our analysis revealed numerous metabolites—including xenobiotics—that bind this protease, which are essential to the lifecycle of the virus. Among these substances, silybin, a flavolignan compound and the main active component of silymarin, is particularly noteworthy. Silymarin is a standardized extract of milk thistle, Silybum marianum, and has been shown to exhibit antioxidant, hepatoprotective, antineoplastic, and antiviral activities. Our results—obtained in silico and in vitro—prove that silybin and silymarin, respectively, are able to inhibit Mpro, representing a possible food-derived natural compound that is useful as a therapeutic strategy against COVID-19. 相似文献
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《Biomedical chromatography : BMC》2018,32(5)
Lipoic acid (LA) is used extensively as a therapeutic agent for the treatment of various diseases. Many methods have been reported for the determination of LA plasma levels and its metabolites after its supplementation, but available information concerning endogenous plasma levels is still scarce. Studies which directly focused on determining the endogenous plasma levels provided highly controversial results, <4.9 nmol/L or 143.7–197.0 nmol/L. The main aim of this study was to verify the levels of free LA in the plasma of 40 individuals (17 women, 23 men). This group was nonsupplemented with LA and met the conditions for incorporation into the blood donors register. We measured the levels of LA using an HPLC method with very sensitive coulometric detection after previous sample preparation including deproteination and solid‐phase extraction with a Phenyl cartridge. Our limit of detection was 1.85 nmol/L and was better than the values reported in studies that directly focused on determining the endogenous plasma levels of LA: 2.4 and 4.9 nmol/L respectively. However, the levels of free LA in the plasma of nonsupplemented voluntary blood donors were not detectable in all cases. The presented results of our study show that endogenous concentrations of LA are <1.85 nmol/L. 相似文献