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1.
研究了二苯并吡喃类染料吡口罗红Y(PY)与核酸作用的共振光散射光谱,在pH11.5~12.0Tris-NaOH缓冲溶液中,1.75×10-5mol/L的PY溶液加入核酸后,体系的共振光散射增强,在364.0nm处,存在一共振光散射增强峰,其增强强度(△IRLS=I-I0)与核酸浓度呈线性关系,据此建立了一种测定纳克级核酸的简便灵敏的方法.对于fsDNA,方法的线性范围为27.0~625ng/mL,检出限为8.1ng/mL;对于ctD NA,方法的线性范围为39.0~500ng/mL,检出限为11.7ng/mL;对于yRNA,方法的线性范围为59.0~375ng/mL,检出限为17.7ng/mL.建立的方法已用于六种合成样品的测定,结果令人满意.  相似文献   

2.
应用中氮茚衍生物-花菁离子缔合平衡体系建立了一种测定痕量核酸的方法.中氮茚衍生物的最大发射波长在385nm,在一定量花菁存在下,其荧光强度显著猝灭,核酸的加入又可使其荧光回复.在最佳条件下,荧光回升与核酸浓度成正比.标准曲线线性范围:小牛胸腺DNA(CTDNA)为2-500ng/mL;鱼精子DNA(FSDNA)为2-400ng/mL.相应的检测限:CTDNA为0.92ng/mL;FSDNA为0.85ng/mL.应用本法对3个实际样品进行了测定,结果令人满意.  相似文献   

3.
在室温条件下,阿的平能嵌入DNA的碱基对之间,而阿的平荧光大幅猝灭,酸性介质下,激发波长348,428或449nm,碱性介质下激发波长为362或422nm,发射波长均为502nm,基于此对核酸进行定量测定,方法简单,快速,灵敏,对于双链或单链小牛胸腺DNA,线性范围0-4μg/mL,检测限0.03μg/mL,共存物质干扰小,在不同浓度ctDNA存在下,温度对荧光光猝灭的影响结果显示猝灭方式为静态猝灭。  相似文献   

4.
 采用光度法研究了派罗宁GS与核酸的结合反应,结果表明在pH 6.0左右的介质中,派罗宁GS与核酸在室温下能迅速结合形成紫红色复合物,该复合物在570 nm处有正吸收峰,在540 nm处有负吸收峰.据此,建立了1个测定核酸的双峰双波长光度分析新方法.用该方法测定小牛胸腺DNA(ctDNA)、鱼精子DNA(fsDNA)、酵母RNA(yt RNA)及热变性ctDNA(Dct DNA)的检出限均低于0.011μg/mL.方法简单、快速,试剂及反应体系稳定、选择性好、准确度高,用于4个合成试样的分析,回收率为96.1%~103.0%.  相似文献   

5.
在8.0×10-3mol/LHCl-2.0×10-3mol/LKI介质中,吖啶橙(AO)在515nm处有1个同步荧光峰.当有NO-2存在时,NO-2与过量的I-反应生成I-3,I-3与AO形成缔合微粒,在320,560nm处产生2个共振散射(RS)峰,在470nm处产生1个同步散射峰.NO-2浓度在0.068~7.36mg/L范围内与320nm波长处的共振散射光强度成线性关系.据此建立了一个测定水中NO-2的共振散射光谱分析法.光谱研究结果表明,(AO-I3)n缔合微粒和界面的形成是导致体系RS增强的根本原因.  相似文献   

6.
在8.0×10-3 mol/L HCl-2.0×10-3 mol/L KI介质中,吖啶橙(AO)在515 nm处有1个同步荧光峰.当有NO-2存在时,NO-2与过量的I-反应生成I-3,I-3与AO形成缔合微粒,在320,560 nm处产生2个共振散射(RS)峰,在470 nm处产生1个同步散射峰.NO-2浓度在0.068~7.36 mg/L范围内与320 nm波长处的共振散射光强度成线性关系.据此建立了一个测定水中NO-2的共振散射光谱分析法.光谱研究结果表明,(AO-I3)n缔合微粒和界面的形成是导致体系RS增强的根本原因.  相似文献   

7.
基于DNA与RNA对中药葛根素的荧光有猝灭作用而建立了DNA、RNA的测定新方法.在生理pH值附近,当激发波长为266 nm,葛根素在460 nm处出现荧光,随着核酸的加入,葛根素的荧光强度线性下降,本文对4种不同核酸的线性方程、线性范围、检测限进行了测定,对外来离子的干扰进行了研究,与经典的核酸测定方法进行了对比,并对核酸使葛根素荧光猝灭作用机理进行了探讨.  相似文献   

8.
在0.16~0.32 mol/L的盐酸溶液中, 维多利亚蓝4R(VB4R)的共振瑞利散射(RRS)、二级散射(SOS)和倍频散射(MFS)均十分微弱. 在过量碘化物存在下, 当硒(Ⅳ)氧化I-形成I-3配阴离子并进一步与VB4R反应形成离子缔合配合物时, 3种散射均大大增强并产生相应的散射光谱. 最大RRS波长位于582 nm, 另在320 nm, 410 nm, 452 nm, 470 nm, 800 nm和940nm处有强度较低的RRS峰;此时最大SOS峰位于810 nm, 并在650 nm和940 nm有两个较小的SOS 峰,而最大MFS峰位于405 nm并在320 nm和475 nm处有两个较小的MFS峰. 在各自的最大散射波长处, 硒(Ⅳ)在0~1.0μg/25 mL(RRS和MFS法)和0~1.5μg/25 mL (SOS法)的浓度范围内与散射强度ΔI成正比. 方法有很高的灵敏度, 对硒(Ⅳ)的检出限分别为0.24 μg/mL (MFS),0.48 μg/mL(RRS)和 0.60 ng/ml(SOS). 3种散射法均可用于痕量硒(Ⅳ)的测量.  相似文献   

9.
过氧亚硝酸根(ONOO-)作为一种内源性的活性氧化物(ROS)和活性氮化物(RNS),在多种生理和病理过程中发挥至关重要的作用。文章基于氧杂蒽结构设计合成了一种长波长发射的比率荧光探针DHX-BE。采用紫外可见吸收光谱法和荧光光谱法研究了DHX-BE对ONOO-的特异性识别。结果表明,DHX-BE在658 nm处表现出深红色荧光发射,当加入ONOO-时,该红色荧光逐渐降低,并在554 nm处产生绿色发射峰,荧光发射位移高达104 nm。同时,DHX-BE的荧光强度比值(F554 nm/F658 nm)与ONOO-浓度呈现良好的线性关系,线性范围为0μmol/L~10μmol/L,检出限为20.4 nmol/L。此外,DHX-BE对ONOO-具有响应速度快(5 min)、选择性好和光稳定性强等优点。高分辨质谱分析表明DHX-BE对ONOO-的响应机理为苯硼酸酯的氧化水解和碳碳双键的氧化裂解。  相似文献   

10.
用新洁尔灭测定核酸的共振瑞利散射方法研究   总被引:3,自引:0,他引:3  
在酸性BR缓冲溶液 ,新洁尔灭(溴化十二烷基二甲基苄铵,BB)与小牛胸腺DNA(ctDNA)鲱鱼精DNA(hsDNA)、鲑鱼精DNA(sDNA)和酵母RNA(yRNA)反应,产生强烈的共振瑞利散射(RRS)增强,其最大散射峰位于470nm处。由此建立测定微量核酸的新分析方法。ctDNA,hsDNA,sDNA和yRNA的测定范围分别为0-4.2μg/mL,0-4.0μg/mL,0-4.6μg/mL,0-12.0μg/mL;检出限(3σ)分别为8.6ng/mL,9.2ng/mL,9.9ng/mL和27.9ng/mL。研究发现RRS强度变化与核酸构象转变有密切联系,因此RRS法有望成为研究核酸构象的有用手段。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

15.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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