太子参及其种植土壤中16种元素的测定

目的:建立电感耦合等离子体原子发射光谱法(ICP-AES)测定太子参及其种植土壤中16种元素含量的方法.方法:采用微波消解处理样品,并考察了不同元素间相互干扰,采用ICP-AES同时测定16种元素.结果:对所测定元素的相时标准偏差(RSD)均小于4%,回收率在95%～104%之间,结果可信度高.结论:本研究所建立的方法具有简便、快速、准确、灵敏度高的优点.     

灰绿藜中六种矿物质元素含量的测定

目的：研究了灰绿藜不同部位矿质元素的分布特点及动态变化。方法：采用火焰原子吸收分光光度法对灰绿藜各部位中的K、Ca、Mg、Cu、Fe和Na六种元素的含量进行了测定与分析。结果：从测定结果可见,不同生长时期灰绿藜的各部位,其矿物元素含量不同。随着生长时间变化,各元素在各部位的增长趋势也有升有降。测定结果的相对标准偏差为0.001%～0.580%,回收率为91.51%～114.32%。结论：得出灰绿藜不同部位矿质元素的分布与变化。     

电感耦合等离子质谱法(ICP-MS)法测定茵栀黄注射液中有害元素铅、砷、镉、汞、铜的含量

建立了电感耦合等离子体质谱法(ICP-MS)测定茵栀黄注射液中Pb、As、Cd、Hg、Cu 5种元素的方法。样品经微波消解后,直接用ICP-MS同时测定上述5种元素,结果5种元素的检出限分别在5～1250 ng/L之间;线性良好,线性相关系数均为r≥0.999;精密度RSD3.5%;回收率在95.7%～107.5%之间。方法操作简便、分析速度快、灵敏度高,各项分析性能指标均达到要求,适用于茵栀黄注射液中有害元素的测定。     

神农架林区高山野菜中矿质元素含量分析

测定了神农架林区4种野菜中矿质元素的含量,为消费者选择食用野生蔬菜提供理论依据。方法:硒(Se)测定依据GB 5009.93—2010;其他元素测定依据ICP法。结果:何首乌尖中除硒含量比家乡菜略低外,其他矿质元素含量均比其他几种野生蔬菜含量高,有的甚至高出几十倍。而蹦芝麻茎中各矿质元素含量(硒除外)均低于其他几种野菜含量;蹦芝麻茎和蹦芝麻嫩荚中矿质元素含量存在明显的差异。而与常见蔬菜相比,野生蔬菜中矿质元素含量明显高于常见蔬菜,具有更高的营养价值,具有广阔的开发利用前景。     

赤果鱼木叶中微量和稀土元素的测定

利用等离子体质谱仪 (ICP MS)测定了赤果鱼木叶中微量元素和稀土元素 ,共测定了 48种元素的含量     

微波消解-ICP-MS法同时测定干紫菜中28种元素

采用微波消解,建立了电感耦合等离子体质谱法（ICP-MS）同时测定干紫菜中28种元素的检测方法。结果显示：在0.05～100.0μg/L浓度范围内,28种元素标准曲线线性关系良好,相关系数（r2）≥0.9998;检出限在0.05～0.50μg/L之间,加标回收率在92.8%～102.6%之间,相对标准偏差（RSD）在0.8%～2.7%之间;根据干紫菜中元素含量测定结果,干紫菜富含对人体有益的I、K、Na、P、Ca、Mg、Fe元素,尤其是I含量高达18 695mg/kg,而对人体危害有害的重金属元素As、Ag、Cd、Hg、Pb含量较低。通过对干紫菜中元素含量测定,可为干紫菜质量检测、质量评价及其产业可持续发展提供科学依据。     

ICP-OES测定铁皮石斛干花中多种元素

用微波消解和马弗炉灰化消解分别处理云南、浙江、霍山三种产地的铁皮石斛干花,再用电感耦合等离子体发射光谱仪(ICP-OES)定量分析多种元素含量,构建一种快速测定石斛干花元素含量的方法。结果表明,微波消解结合ICP-OES测出三产地石斛花存在常量元素K、Ca、Na、Mg和微量元素Se、Co、Cu、Mn、Fe、Cr、Sr、Zn、B,且含量均高于马弗炉消解结合ICP-OES测定结果;有害元素As、Pb、Cd、Hg和潜在有害元素Sb、Ba、Sn、Al、Ni均未检出;内标回收率均在92.5%-110.0%之间,相对标准偏差(RSD)<10%。试验探究出微波消解和ICP-OES的结合不仅效率高,检测成本低,运行稳定且测定结果准确可靠,可用于铁皮石斛干花中多元素分析研究。     

火焰原子吸收法测定黑老虎中八种矿质元素

用火焰原子吸收光谱法测定了黑老虎中常见的八种元素Ｚｎ、Ｆｅ、Ｃａ、Ｃｕ、Ｋ、Ｎａ、Ｍｎ、Ｍｇ的含量,系统地试验了测定条件,用ＳｒＣｌ２消除了共存在元素间的干扰,实现在同一溶液中测定多种元素,方法简便、快速、准确。     

糙米蛋白质含量与矿质元素含量的相关分析及NIRS模型的建立

利用162份不同类型水稻种质,采用微量凯氏定氮法测定蛋白质含量,原子吸收分光光度法(atomic absorption spec-trophotometry,AAS)测定Mg、Ca、Fe、Zn、Cu和Mn等6种矿质元素含量,火焰光度法测定K含量,分光光度法测定P含量。对糙米蛋白质与矿质元素、矿质元素间进行相关分析;并利用测定的蛋白质含量的化学值,采用偏最小二乘法(partial leastsquares,PLS)建立糙米蛋白质预测的校正模型。结果表明,糙米矿质元素含量大小顺序为P>K>Mg>Ca>Zn>Fe>Cu>Mn,蛋白质与P、K、Cu和Mn等矿质元素极显著或显著正相关;通过比较光谱预处理方法在不同谱区的处理效果:采用一阶导数预处理、谱区为11995.7～7498.3/cm和6102～4597.7/cm建立校正模型的检验和预测效果最佳,糙米蛋白质的近红外测定值和化学测定值之间有较高的相关性,其校正决定系数为92.89,外部验证决定系数为89.91;筛选到小黑谷、小红米和紫糯米等高蛋白、富矿质营养的种质材料,可作为富营养稻米品种创新的亲本材料;通过利用蛋白质和矿质元素间的相关性,借助近红外分析技术(Near-infrared Reflectance Spectroscopy,NIRS)辅助测定蛋白质含量,并间接选择富矿质营养水稻种质,聚合高蛋白和富2种以上矿质元素,可能是水稻营养品质育种的一条有效途径。     

ICP-OES法测定两种喉毛花植物中21种矿质元素北大核心CSCD

本文采用ICP-OES法,测定分析了长梗喉毛花和镰萼喉毛花中的21种矿质元素。所采用方法线性关系良好,r≥0.9990,各元素的检出限均低于0.0036 mg/L,建立了测定喉毛花中多种矿质元素含量的分析方法。结果表明,两种喉毛花中Ca、Mg、Fe三种元素的含量均较高。在检出的人体所需常量和微量元素中,除Se元素外,其他常量、微量元素在长梗喉毛花中含量均高于在镰萼喉毛花中的含量。Pb、As两种重金属元素在镰萼喉毛花中的均含量高于在长梗喉毛花中的含量,Cu则反之。     

Influence of nicotine on tissue trace element concentrations and tissue antioxidant defense

Both altered trace element metabolism and cigaret smoking have been proposed to be risk factors for cardiovascular disease (CVD). Thus, it is important to identify the mechanisms by which cigaret smoke alters trace element metabolism. In the present study, serum trace element concentrations were measured in 19 smokers and 13 nonsmokers. In parallel studies, data from rats treated with 50 mg of nicotine over a 21-d period tested the hypothesis that nicotine induced altered trace element metabolism observed in smokers. Serum Cu and Zn concentrations were significantly higher in smokers than in nonsmokers. Serum nicotine concentrations in rats were comparable to those observed in heavy smokers, but serum trace element concentrations were not significantly altered by nicotine treatment. Tissue trace element concentrations were also not markedly affected by nicotine; however, trace element ratios in liver, kidney, lung, and brain were significantly altered by nicotine treatment. In addition, nicotine-treatment resulted in significantly lower liver glutathione concentrations and higher Cu, Zn superoxide dismutase activity than in controls. These data show that a 50-mg infusion of nicotine over 21 d does not produce in rats the serum trace element abnormalities observed in cigaret smokers. However, nicotine did affect the trace element relationships between tissues as well as components of the free radical defense system.     

不同启动子控制下Ac转座酶基因的表达对玉米Ds因子在水稻中切离频率的影响

用水稻愈伤组织比较了Ac启动子、35S启动子与Ubi启动子控制下Ac转座酶基因（Ts）的表达对Ds因子切离频率的影响。结果表明Ubi启动子与Ac转座酶编码区嵌合基因（Ubipro-Ts）反式激活Ds因子的切离频率最高,达到了72.9%。通过杂交将Ubipro-Ts基因导入Ds因子转化植株,得到9株Ubipro-Ts基因与Ds因子共存的F1代杂交水稻植株,其中有8株Ds因子发生了切离。用Inverse-PCR的方法从其中一株杂交植株中克隆到Ds因子的旁邻序列,其DNA顺序与亲本中Ds因子原插入位点的序列不同,表明Ds因子转座到了新的基因组位点。     

P element transposition in vitro proceeds by a cut-and-paste mechanism and uses GTP as a cofactor.

We have developed an in vitro reaction system for Drosophila P element transposition. Transposition products were recovered by selection in E. coli, and contained simple P element insertions flanked by 8 bp target site duplications as observed in vivo. Transposition required Mg+2 and partially purified P element transposase. Unlike other DNA rearrangement reactions, P element transposition in vitro used GTP as a cofactor; deoxyGTP, dideoxyGTP, or the nonhydrolyzable GTP analogs GMP-PNP or GMP-PCP were also used. Transposon DNA molecules cleaved at the P element termini were able to transpose, but those lacking 3'-hydroxyl groups were inactive. These biochemical data are consistent with genetic data suggesting that P element transposition occurs via a "cut-and-paste" mechanism.     

水稻第4号染色体不同位置的Ds转座子转座行为的分析

使用农杆菌介导的方法转化粳稻品种中花11,构建了在第4号染色体不同位置插入了Ds（dissociation）因子的水稻转化群体和带有Ac（activator）转座酶基因的转化植株。将携带了Ac转座酶基因的植株与不同Ds转化植株杂交,杂交F1代同时带有Ac转座酶和Ds因子（Ac／Ds植株）。用PCR方法检测了杂交F1代Ds的切离频率,结果发现靠近第4号染色体着丝粒附近的Ds转座子切离频率低,而靠近第4号染色体末端区域的Ds转座子切离频率高,这表明Ds转座子的原始插入位置对其杂交后代的切离频率有很大的影响,推测与原始插入位点附近的染色体结构有关。     

Studies on the Rate and Site-Specificity of P Element Transposition

A single genetically marked P element can be efficiently mobilized to insertionally mutagenize the Drosophila genome. We have investigated how the structure of the starting element and its location along the X chromosome influenced the rate and location of mutations recovered. The structure of two P[rosy+] elements strongly affected mobilization by the autonomous "Jumpstarter-1" element. Their average transposition rates differed more than 12-fold, while their initial chromosomal location had a smaller effect. The lethal and sterile mutations induced by mobilizing a P[rosy+] element from position 1F were compared with those identified previously using a P[neoR] element at position 9C. With one possible exception, insertion hotspots for one element were frequently also targets of the other transposon. These experiments suggested that the genomic location of a P element does not usually influence its target sites on nonhomologous chromosomes. During the course of these experiments, Y-linked insertions expressing rosy+ were recovered, suggesting that marked P elements can sometimes insert and function at heterochromatic sites.     

Hair concentrations of calcium, iron, and zinc in pregnant women and effects of supplementation

In this investigation, the concentration levels of hair elements of calcium, iron, and zinc were measured in pregnant women from Tianjin metropolis, China. The subjects were 93 cases of pregnant women who had been suffering from calcium, iron, or zinc deficiency judged by blood tests at the mid-term of the second trimester or early in the third trimester. Of these 93 cases, 82 subjects had their hair element levels measured when the blood tests were conducted. Then, they were supplied with mineral element nutrients of gluconic acidic zinc (noted as Zn-nutrient), gluconic acidic calcium (Ca-nutrient), or/and ferrous sulfate (Fe-nutrient) which were correspondent to the deficient element(s) for more than 2 mo before 84 subjects returned to hospital for further diagnoses and had their hair element levels measured for the second time. Finally, in the third trimester or nearparturient phase, 13 subjects had their hair element levels measured again. Except for the deficiencies of calcium, iron, or/and zinc, these subjects were all healthy without symptoms of any diseases. The concentrations of hair Ca, Fe, and Zn were measured by X-ray fluorescence (XRF) spectrometry. These concentrations of the three hair elements measured at three different times were statistically analyzed. From the analyses, it was clear that hair concentrations of Ca, Fe, and Zn could reflect the effects of supplementation. Also, the mutual resistant effects among Ca-, Fe-, and Zn-nutrients were revealed. However, by appropriate combination, the mutual resistant effects could be depressed and mutual promotional effects might be enhanced. Finally, it could be concluded that mineral element deficiencies might be convalesced by adequate compensations of mineral element nutrients.     

Cross-binding of factors to functionally different promoter elements in c-fos and skeletal actin genes.

A conserved 28-base-pair element in the skeletal actin promoter was sufficient to activate muscle-specific expression when placed upstream of a TATA element. This muscle regulatory element (MRE) is similar in structure to the serum response element (SRE), which is present in the promoters of the c-fos proto-oncogene and the nonmuscle actin genes. The SRE can function as a constitutive promoter element. Though the MRE and SRE differed in their tissue-specific expression properties, both elements bound to the same protein factors in vitro. These proteins are the serum response factor (SRF) and the muscle actin promoter factors 1 and 2 (MAPF1 and MAPF2). The SRF and MAPF proteins were resolved by chromatographic procedures, and they differed in their relative affinities for each element. The factors were further distinguished by their distinct, but overlapping, methylation interference footprint patterns on each element. These data indicate that the differences in tissue-specific expression may be due to a complex interaction of protein factors with these sequences.     

Characterization of nuclear factors binding to AT-rich element in the rat p53 promoter

In this study, we identified AT-rich element located at positions -504 to -516 in the rat p53 promoter by DNase I foot printing assay. This region was previously identified as a positive regulatory element in the murine p53 promoter and designated as PBF1 (p53 binding factor 1) binding site. However, the proteins binding to this AT-rich element have not been identified yet. Therefore, we characterized the binding protein by various biochemical methods. First, we confirmed that by the oligonucleotide competition assay, nuclear factors bound to the AT-rich element in a sequence-specific manner. Two binding proteins were identified in southwestern blotting analysis and the molecular masses of the proteins were 60 and 40 kDa, respectively. The proteins were stable to denaturants or ionic strength. Treatment of chelators showed that the binding proteins did not require divalent cation for DNA-binding activity. In addition, the binding proteins were labile to protease treatment. This study showed that 60 and 40 kDa proteins bound to AT-rich element and the physico-chemical properties provided new insights into the binding proteins.     

A Role for the Kp Leucine Zipper in Regulating P Element Transposition in Drosophila Melanogaster

The KP element can repress P element mobility in Drosophila melanogaster. Three mutant KP elements were made that had either two amino acid substitutions or a single amino acid deletion in the putative leucine zipper domain found in the KP polypeptide. Each KP element was expressed from the actin 5C proximal promoter. The wild-type control construct strongly repressed P element mobility, measured by the GD sterility and sn(w) mutability assays, in a position-independent manner. The single amino acid deletion mutant failed to repress P mobility regardless of its insertion site, while repression of P element mobility by the double amino acid substitution mutants was position dependent. The results show that the leucine zipper of the KP polypeptide is important for P element regulation. This supports the multimer-poisoning model of P element repression, because leucine zipper motifs are involved in protein-protein interactions.