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1.
荧光分析法是一种经济快速的分析方法,具有灵敏度高、选择性好、操作简单等优点。鉴于美洲大蠊多肽(DPSFNSWG-NH2)自身具有荧光的特性,通过实验建立一种美洲大蠊多肽(DPSFNSWG-NH2)的荧光检测新方法。实验结果表明,在最佳条件下,美洲大蠊多肽(DPSFNSWG-NH2)在0.12 ~ 31.25 μg/mL浓度内与荧光强度之间具有良好的线性关系,线性回归方程为y = 10.698x + 14.625,R2= 0.994 2,检测限为0.09 μg/mL,将所建立的新方法用于美洲大蠊药材中其多肽(DPSFNSWG-NH2)的测定,回收率为85.50% ~ 89.47%。本研究方法操作简便、快速、准确,具有良好的分析应用前景,可用于美洲大蠊中DPSFNSWG-NH2多肽的含量测定。  相似文献   

2.
石墨相氮化碳纳米薄片(g-C3N4NSs)具有优良的电化学发光(ECL)性能和良好的成膜特性.以g-C3N4NSs作为ECL材料,利用其良好的成膜性能将其固定在玻碳电极(GCE)上,再以毒死蜱(CPF)作模板分子,甲基丙烯酸(MAA)作功能单体,通过分子自组装制备分子印迹聚合物(MIP).将该聚合物引入g-C3N4NSs修饰电极,构建了一个MIP-ECL传感器.除去模板分子的传感器能够选择性识别CPF,利用CPF对g-C3N4NSs ECL信号的淬灭作用实现了CPF的高灵敏、高选择性检测.传感器对CPF的线性响应范围是1.0×10-8~1.0×10-4mol·L-1,检出限(LOD)是5.0 nmol·L-1,用于蔬菜中CPF残留量检测,结果令人满意.  相似文献   

3.
实验探究了二硫化钼(MoS2)作为一种新型材料与贵金属纳米粒子金(Au)、铂(Pt)的复合基底对于过氧化氢(H2O2)的还原性检测,采用氧化铟锡导电玻璃(ITO)作为电极,制备出了基于Pt-Au-MoS2-ITO的生物传感器,为H2O2还原性检测的便携性操作打下了基础.实验采用电化学沉积的方法制备材料,同时使用循环伏安(CV)法、计时电流法等传统电化学手段表征了传感器电化学性能,采用场发射扫描电子显微镜(FE-SEM)来表征传感器表面形貌.建立了用于H2O2还原检测的、具有高检测限、高灵敏度和宽检测范围的传感器.  相似文献   

4.
为探索磷酸化处理对多肽结合钙能力的促进作用,以蚕蛹多肽为研究对象,采用不同种类和添加量的磷酸化试剂对其进行磷酸化改性,再与CaCl2反应制备蚕蛹多肽结合钙复合物,并对样品进行钙和磷含量测定、磷酸化位点检测、红外光谱分析和扫描电镜分析。研究结果表明:Na3PO4、NaH2PO4、(NaPO3)6 3种试剂可与蚕蛹多肽发生磷酸化反应,改性后蚕蛹多肽结合钙含量可从145.12mg/g提高至202.32mg/g ;不同种类磷酸化试剂处理对多肽的结合钙能力无显著性差异,但磷酸化程度对肽结合钙能力有较大影响;多肽结合钙复合物中钙含量随磷酸化试剂的增加先升高后下降,当采用质量分数为0.50%的NaH2PO4时,改性后蚕蛹多肽结合钙含量达到最大值。红外光谱和磷酸化位点检测表明:NaH2PO4处理可使蚕蛹酶解产物中的17种肽段被磷酸化,增加磷酸化位点22个;肽段主要通过与丝氨酸和苏氨酸上的—OH反应接入磷酸基团。研究表明,磷酸化改性方法可显著提高多肽结合钙能力,希望为高效的补钙制品开发提供新的思路和方法。  相似文献   

5.
金纳米粒子(Au NPs)敏化二氧化锡(SnO2)半导体,不仅拓宽了材料对可见光的吸收范围,且异质界面易形成肖特基势垒,有效促进光生电子空穴对e-/h+的分离,提高传感器的灵敏度.探索了一步合成法制备SnO2@Au NPs异质材料,该材料具有较高的光电转化效率,表现出较好的光电性能.基于此纳米复合材料均匀牢固的特点,可在其表面修饰识别层,构建“三明治”夹心结构生物传感器,实现对钙卫蛋白(CP)的特异性光电测定.线性范围为0.01~20.00 μg·mL-1,检测限低至3.2 ng·mL-1,且特异性好、稳定性佳.此外,传感器也成功用于检测实际血样中的CP,并获得了较好的回收率,可实现对CP的快速无创性检测.  相似文献   

6.
基于硫化镉量子点(CdS QDs)对三联吡啶钌(Ru(bpy)32+)电致化学发光(ECL)信号的增敏作用,在电极表面滴涂CdS QDs,然后引入含有多壁碳纳米管(MWCNTs)和金纳米粒子(Au NPs)的(Ru(bpy)32+)复合物(MWCNTs-Au NPs-Ru(bpy)32+),得到了自增强CdS/Ru(bpy)32+ECL传感器.该传感器同时包含了ECL物质Ru(bpy)32+和共反应剂CdS QDs,具有自增强特点,MWCNTs和Au NPs的存在可进一步放大传感器的信号.邻苯二酚的电极氧化产物与Ru(bpy)32+之间存在能量转移,导致ECL信号淬灭,从而实现了邻苯二酚的灵敏检测,线性响应范围为5.0×10-9~1.0×10-5 mol·L-1,检出限为1.5×10-9 mol·L-1.该传感器用于河水中邻苯二酚的检测,结果令人满意.同时,传感器也表现出良好的重现性和稳定性.  相似文献   

7.
目的:研究美洲大蠊提取物CII-3抗HSV-2作用。方法:通过MTT法和CPE法测定美洲大蠊提取物CII-3抗HSV-2活性,计算其TC50、IC50及TI。以雌性小鼠生殖器疱疹为动物模型,在小鼠阴道内注射50μL HSV-2病毒原液,1次/d,连续7 d造模。以ACV为阳性对照,采用灌胃给药治疗10 d。应用ELISA试剂盒检测小鼠血清中TNF-α、IFN-γ、IL-2的水平变化;称量小鼠免疫器官重量,计算脏器指数。结果:美洲大蠊提取物CII-3有抑制HSV-2致细胞病变的作用,其TC50值为190.55μg/m L,IC50值为28.71μg/m L,TI值为6.64μg/m L;美洲大蠊提取物CII-3能够提高小鼠血清中TNF-α、IFN-γ、IL-2的水平,同时能够使小鼠的免疫器官重量增加。结论:美洲大蠊提取物CII-3有抗HSV-2作用,其抗病毒作用可能是通过提高机体免疫功能来实现。  相似文献   

8.
以五水硫酸铜(CuSO4·5H2O)和单宁酸(Tannic acid,TA)为原料,通过一步法制备得到单宁酸铜( CuTA)纳米片。由材料的红外、扫描电镜结果可知,本实验成功制备了CuTA。研究表明,所制备材料可催化过氧化氢(H2O2)产生O2,据此本研究建立了一种比色分析方法用于检测H2O2,并优化了氧化反应的显色条件。在最优条件下,H2O2的检测线性范围为400~1400 μM,检出限为5.2 μM。将本方法用于检测实际样品牙膏中的H2O2,回收率可达96.6%~102.2%。研究结果表明,所构建的比色传感器可实现对H2O2的定量检测。  相似文献   

9.
魏小平  李建平 《广西科学》2001,8(3):189-191,194
将析相萃取技术与催化动力学光度法相结合,建立了一个测定痕量钴的聚合物-盐-水体系析相萃取-催化动力学光度法。在Na2HPO4-NaOH缓冲溶液中,Co2+可灵敏催化过氧化氢氧化苯芴酮褪色反应,用聚乙烯吡咯烷酮-硫酸铵-水的非有机溶剂萃取体系萃取出未被氧化的指示物苯芴酮与水相中的氧化剂分离,从而可终止该反应并通过测量有机相的吸光度显著提高分析的灵敏度。钴浓度在0 μg/L~0.03μg/L范围内与ΔA呈线性关系,检测限为3.4×10-5 μg/L。该方法灵敏度高,选择性好,用于直接测定水样中超痕量钴,结果满意。  相似文献   

10.
产环己酰亚胺新菌株YIM41004种子培养基优化研究初报   总被引:4,自引:1,他引:4  
 对产环己酰亚胺新菌株Streptomyces yunnanensis YIM41004的摇瓶种子培养基进行了优化,获得最佳配方为葡萄糖25 g,蛋白胨7.5 g,酵母膏7.5 g,CaCO33 g,MgSO4.7H2O 1 g,MnSO4.4H2O 0.1 g,KH2PO40.2 g,水1 000 mL;最佳培养条件为起始pH7.8,500mL种子瓶装量100mL,最佳种龄32~36 h.用优化后的种子培养基培养种子用于摇瓶发酵,结果表明在接种量为10%体积分数时,环己酰亚胺产量达到最高,为498.9 mg.L-1,比用原始种子培养基时的产量450 mg.L-1高出10.7%.  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.
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   

13.
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   

14.
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   

15.
In the 19th century the society was controlled by men, and women were just appendants of them, they had not any rights and freedom. But Jane was an exception, she showed some characteristics of early feminist. Jane showed her characteristics of feminism in three aspects: rebellion, equality, and independence. These characteristics were helpful to her success, and feminism is the only way out for women of that time.  相似文献   

16.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

17.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

18.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

19.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

20.
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