首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 296 毫秒
1.
近日,中国科学院大连化物所袁景利等人在纳米稀土荧光生物标记材料的制备与生化分析应用研究工作中,成功地研制出一系列粒径在25~55nm的硅胶基质搀杂型纳米稀土荧光生物标记材料、表面带有活性氨基的搀杂型(或共价键合型)纳米稀土荧光生物标记材料及氧化锆基质的搀杂型纳米稀土荧光生物标记材料。  相似文献   

2.
生物标记用发光材料研究现状   总被引:2,自引:0,他引:2  
综述了生物标记用发光材料研究进展及其应用现状,对各种材料的特点进行了分析,指出以绿色荧光蛋白等为代表的荧光材料将是未来生物标记的主流.  相似文献   

3.
正与传统的分子荧光标记材料(如荧光染料)相比,稀土上转换纳米发光材料不仅化学稳定性高、荧光寿命长、潜在生物毒性低,而且由于采用近红外光源激发具有较大的光穿透深度、无生物组织自荧光以及对生物组织几乎无损伤等显著优点,在荧光生物检测和成像等领域具有重要的应用前景。目前上转换纳米荧光标记材料发展的瓶颈问题是其量子产率低。提高上转换发光效率、探索新型高效的上转换纳米荧光标记材料一直是人们关注的焦点与努力的目标,也是该类材料能否获得实际应用的关键。在国家自然科学基金杰出青年和促进海峡两岸科技合作联合基金、科技部863计划和重大科学仪器开  相似文献   

4.
选用2种铀配合物分别与4种典型的生物分子多巴胺(DA)、抗坏血酸(AA)、尿酸(UA)和牛血清白蛋白(BSA)相互作用,采用荧光分光光度计进行荧光标记性质测试,研究铀配合物对4种生物分子的荧光标记性质。结果表明,4种生物分子对铀配合物的荧光发光产生了一定影响,在不同浓度梯度的生物分子中,浓度越大对铀配合物荧光强度的影响也越大;随着生物分子浓度的增大,出现了荧光猝灭现象,这2种铀配合物可以作为生物分子的荧光探针。为铀配合物在生物分子荧光标记研究方面的应用提供了一定的依据。  相似文献   

5.
用于生物标记的半导体量子点研究   总被引:1,自引:0,他引:1  
半导体量子点的独特光学性质使之成为理想的荧光探针材料,在生物医学领域具有广阔的应用前景.本文评述了目前量子点合成、表面修饰、结合生物分子的方法,以及半导体量子点在生物标记应用中相对于传统有机染料的优点.  相似文献   

6.
《广东化工》2021,48(9)
碳点是一种强荧光、高稳定性的荧光纳米材料,在生物标记与成像领域具有较大的应用潜力。本研究合成了一种阳离子型的荧光碳点,碳点在紫外激发下发出黄色荧光。将碳点与大肠杆菌混合后,阳离子碳点可以直接作用于大肠杆菌而使大肠杆菌标记上荧光,并可以在荧光显微镜下荧光成像。进一步的研究证明该阳离子碳点也可以对枯草芽孢杆菌、阿氏芽孢杆菌等其他细菌标记和荧光成像,具备发展成为一种快速标记细菌的通用荧光染料的潜力。  相似文献   

7.
技术贸易     
<正>新型纳米晶荧光材料及其应用技术一、项目简介北京理工大学材料学院纳米光子学材料与技术实验室在致力于开发性能优异、绿色、实用的纳米晶发光材料研究。在国家973计划项目和自然基金项目的支持下,研制出一种基于铜铟硫(CuInS_2)和铜铟硒(CuInSe_2)的新型、绿色、低毒荧光纳米晶材料,已在白光照明、发光二极管、生物标记、太阳能电池  相似文献   

8.
在生物医学领域,对细胞、生物分子进行染色、修饰标记和检测一直是生物医学分析的重要内容.近年来,纳米材料与生物检测技术的结合,使得生物分子的检测有了重要的发展.用30%H2O2/ACOH(V∶V=2∶1)混合氧化性酸溶液回流蜡烛烟炱制备得到荧光碳纳米粒子,用不同浓度的荧光碳纳米粒子对Hela细胞进行荧光标记,在激光共聚焦...  相似文献   

9.
通过酸催化的缩合反应合成了一种荧烷染料2,研究了其在不同溶剂中的光谱行为。对化合物2的游离氨基进行酰化,得到了新型的荧光染料3。利用核磁共振波谱、高分辨质谱对3进行了结构表征。考察了化合物3在不同的p H水溶液的紫外吸收和荧光光谱变化。研究表明,该化合物在生理p H范围内保持螺环内酯开启状态,并保持较稳定的荧光强度,有作为生物标记及生物成像材料的潜力。  相似文献   

10.
用荧光物质8-氨基-1,3,6奈三磺酸二钠盐(ANTS)对蛴螬活性多糖进行荧光标记,对反应时间、温度、pH值、ANTS浓度进行了单因素考察,采用UV-Vis、Flu、HPGFC等方法对标记结果进行确证。结果表明,蛴螬多糖荧光标记的最佳条件是pH值为5.5,40℃条件下反应20h时反应率最高,其荧光取代度为1.56%。实现了荧光检测器检测或追踪多糖,为多糖的生物机制研究及药代动力学的研究提供一定思路。  相似文献   

11.
王彦  左宁  姜媛媛  陈芳媛 《化工进展》2020,39(4):1539-1549
污泥生物炭中氮硫元素含量高,其氮硫行为和环境效应对全球气候变化的影响不容忽视。以往的研究中,研究者往往以富碳生物炭作为主要研究对象,关注碳对全球气候变化的行为和功效,而对氮硫元素的作用关注不够。本文从原始污泥基本性质到其热解过程,再到生物炭的老化,逐步对污泥生物炭整个生命周期内氮硫的行为及其环境效应研究进行综述,并对未来应注重开展的研究方向进行展望,为生物炭中氮硫元素固定、释放及与之关联的环境效应和温室气体排放控制研究提供理论基础。分析表明,污泥中氮元素含量普遍高于硫元素,且热解过程中氮比硫更容易转移至气相产物。氮硫元素随热解温度的增加,在三相产物中的分配都是炭中持续减少,油中先增后减,气中一直增加。高温(>800℃)条件下,气相中的氮含量高于固相,而硫元素则仍然主要存在于固相中。污泥生物炭老化及其环境效应研究表明,污泥生物炭氮硫元素与土壤的相互作用及其温室效应问题在今后的研究中应引起重视。  相似文献   

12.
Sporadic amyotrophic lateral sclerosis (sALS) is a fatal progressive neurodegenerative disease affecting upper and lower motor neurons. Biomarkers are useful to facilitate the diagnosis and/or prognosis of patients and to reveal possible mechanistic clues about the disease. This study aimed to identify and validate selected putative biomarkers in the cerebrospinal fluid (CSF) of sALS patients at early disease stages compared with age-matched controls and with other neurodegenerative diseases including Alzheimer disease (AD), spinal muscular atrophy type III (SMA), frontotemporal dementia behavioral variant (FTD), and multiple sclerosis (MS). SWATH acquisition on liquid chromatography-tandem mass spectrometry (LC–MS/MS) for protein quantitation, and ELISA for validation, were used in CSF samples of sALS cases at early stages of the disease. Analysis of mRNA and protein expression was carried out in the anterior horn of the lumbar spinal cord in post-mortem tissue of sALS cases (terminal stage) and controls using RTq-PCR, and Western blotting, and immunohistochemistry, respectively. SWATH acquisition on liquid chromatography-tandem mass spectrometry (LC–MS/MS) revealed 51 differentially expressed proteins in the CSF in sALS. Receiver operating characteristic (ROC) curves showed CXCL12 to be the most valuable candidate biomarker. We validated the values of CXCL12 in CSF with ELISA in two different cohorts. Besides sALS, increased CXCL12 levels were found in MS but were not altered in AD, SMA, and FTD. Therefore, increased CXCL12 levels in the CSF can be useful in the diagnoses of MS and sALS in the context of the clinical settings. CXCL12 immunoreactivity was localized in motor neurons in control and sALS, and in a few glial cells in sALS at the terminal stage; CXCR4 was in a subset of oligodendroglial-like cells and axonal ballooning of motor neurons in sALS; and CXCR7 in motor neurons in control and sALS, and reactive astrocytes in the pyramidal tracts in terminal sALS. CXCL12/CXCR4/CXCR7 axis in the spinal cord probably plays a complex role in inflammation, oligodendroglial and astrocyte signaling, and neuronal and axonal preservation in sALS.  相似文献   

13.
For the clinical application of biodegradable hemostatic surgical clips in laparoscopic surgery, it is necessary to determine their degradability and biocompatibility. Herein, in vitro and in vivo studies were undertaken to evaluate the degradability and biocompatibility of bioabsorbable clips made of poly(p-dioxanone). Changes in weight loss, pull-off force, differential scanning calorimetry (DSC), and scanning electron microscopy (SEM) of the poly(p-dioxanone) clips were determined after they were degraded in deionized water and phosphate buffer saline for the in vitro experiment and in laparoscopic models of bile duct ligation(BDL) and right gastroepiploic artery ligation(GEAL) using New Zealand white rabbits for the in vivo experiment. Changes in weight loss and pull-off force were greater in the in vivo experiment than the in vitro experiment. DSC showed the greatest variation in the degree of crystallinity of the clips degraded in deionized water. Stark differences in SEM were observed after 4 weeks of degradation both in vitro and in vivo. Furthermore, the cytocompatibility of the clips was considered satisfactory because the L929 cells could adhere to the clips and proliferate adequately in the presence of the clip extract. Biocompatibility was inferred based on the histological analysis of BDL and GEAL, no significant inflammatory responses were observed after 4 weeks of ligation.  相似文献   

14.
Aging is a complex process that involves the accumulation of deleterious changes resulting in overall decline in several vital functions, leading to the progressive deterioration in physiological condition of the organism and eventually causing disease and death. The immune system is the most important host-defense mechanism in humans and is also highly conserved in insects. Extensive research in vertebrates has concluded that aging of the immune function results in increased susceptibility to infectious disease and chronic inflammation. Over the years, interest has grown in studying the molecular interaction between aging and the immune response to pathogenic infections. The fruit fly Drosophila melanogaster is an excellent model system for dissecting the genetic and genomic basis of important biological processes, such as aging and the innate immune system, and deciphering parallel mechanisms in vertebrate animals. Here, we review the recent advances in the identification of key players modulating the relationship between molecular aging networks and immune signal transduction pathways in the fly. Understanding the details of the molecular events involved in aging and immune system regulation will potentially lead to the development of strategies for decreasing the impact of age-related diseases, thus improving human health and life span.  相似文献   

15.
Stress and strain state of concrete during freezing and thawing cycles   总被引:3,自引:0,他引:3  
The objective of this work is to calculate the pressures, stresses, and strains induced into moist concrete during freezing and thawing. The applied theory is based on thermodynamics and the linear theory of elasticity. If no additional salts are dissolved in the pore water the inputs needed in the theory are relative humidity and temperature measured in the sample chamber and inside concrete and evaporable water amount in the pore structure. Theoretical results were compared with the test results made with two concretes cured under water or at 96% relative humidity. One of the concretes was air entrained and in the comparison concrete no air-entraining agents were used. In the test cylinders cured under water the largest tensional stresses in freezing occurred on the surface of the test cylinders both in the axial and tangential direction. The largest tensional stress was 2.2 MPa, both in air-entrained and in non air-entrained concretes. The largest tensional stresses in the warming phase took place at the end of the thawing period when the chamber temperature was around +5 °C. Then the maximum tension occurred in the middle of the concrete cylinder in the axial direction of the cylinder. This maximum tensional stress was over 2.5 MPa in the air-entrained concrete cured in the relative humidity of 96%. The thermodynamic pumping effect at the end of the thawing phase in every cycle can increase the pore water amount remarkably if free water or moisture is available on the surface of the structure or in the environment vapor. The thermodynamic pumping effect seems to be remarkably greater and more dangerous in air-entrained concretes.  相似文献   

16.
宝钢转炉钢包用耐火材料的现状及发展趋势   总被引:5,自引:3,他引:5  
邱文冬  牟济宁  汪宁 《耐火材料》2002,36(4):231-234
综述了宝钢转炉钢包用耐火材料的变化过程及使用现状 ,重点介绍了近年来宝钢在钢包耐火材料使用上的一些技术进步 ,提出了存在的问题及对策 ,展望了今后宝钢转炉钢包的发展方向。  相似文献   

17.
Crystal-bearing cells or idioblasts, which deposit calcium oxalate, are located in various tissues and organs of many plant species. The functional significance of their formation is currently unclear. Idioblasts in the leaf parenchyma and the development of crystal-bearing cells in the anther tissues of transgenic tomato plants (Solanum lycopersicon L.), expressing the heterologous FeSOD gene and which showed a decrease in fertility, were studied by transmission and scanning electron microscopy. The amount of calcium oxalate crystals was found to increase significantly in the transgenic plants compared to the wild type (WT) ones in idioblasts and crystal-bearing cells of the upper part of the anther. At the same time, changes in the size and shape of the crystals and their location in anther organs were noted. It seems that the interruption in the break of the anther stomium in transgenic plants was associated with the formation and cell death regulation of a specialized group of crystal-bearing cells. This disturbance caused an increase in the pool of these cells and their localization in the upper part of the anther, where rupture is initiated. Perturbations were also noted in the lower part of the anther in transgenic plants, where the amount of calcium oxalate crystals in crystal-bearing cells was reduced that was accompanied by disturbances in the morphology of pollen grains. Thus, the induction of the formation of crystal-bearing cells and calcium oxalate crystals can have multidirectional effects, contributing to the regulation of oxalate metabolism in the generative and vegetative organs and preventing fertility when the ROS balance changes, in particular, during oxidative stresses accompanying most abiotic and biotic environmental factors.  相似文献   

18.
Uterine inflammation is a very common and serious pathology in domestic animals, the development and progression of which often result from disturbed myometrial contractility. We investigated the effect of inflammation on the protein expression of galanin (GAL) receptor subtypes (GALR)1 and GALR2 in myometrium and their role in the contractile amplitude and frequency of an inflamed gilt uterus. The gilts of the E. coli and SAL groups received E. coli suspension or saline in their uteri, respectively, and only laparotomy was performed (CON group). Eight days later, the E. coli group developed severe acute endometritis and lowered GALR1 protein expression in the myometrium. Compared to the pretreatment period, GAL (10−7 M) reduced the amplitude and frequency in myometrium and endometrium/myometrium of the CON and SAL groups, the amplitude in both stripes and frequency in endometrium/myometrium of the E. coli group. In this group, myometrial frequency after using GAL increased, and it was higher than in other groups. GALR2 antagonist diminished the decrease in amplitude in myometrium and the frequency in endometrium/myometrium (SAL, E. coli groups) induced by GAL (10−7 M). GALR1/GALR2 antagonist and GAL (10−7 M) reversed the decrease in amplitude and diminished the decrease in frequency in both examined stripes (CON, SAL groups), and diminished the drop in amplitude and abolished the rise in the frequency in the myometrium (E. coli group). In summary, the inflammation reduced GALR1 protein expression in pig myometrium, and GALR1 and GALR2 participated in the contractile regulation of an inflamed uterus.  相似文献   

19.
通过测量聚丙烯腈(PAN)纤维在空气和臭氧气氛下预氧化过程中的热应力行为,比较空气和臭氧气氛中预氧化所得纤维的物化性质。结果表明:PAN纤维在臭氧气氛中进行预氧化时,纤维的物理收缩应力和化学收缩应力比空气中的小,应力松弛严重;纤维在臭氧气氛中的敏感温度均比空气中的高,化学反应推迟;相同的升温速率下,臭氧气氛中纤维发生化学反应的时间较空气中的少,臭氧中纤维的化学反应速率较空气中的快;两种气氛中纤维的体积密度相差很小,臭氧中纤维皮芯结构状况较严重。  相似文献   

20.
李静 《日用化学品科学》2007,30(2):10-11,15
叙述了中东地区各国化妆品和盥洗用品市场的现状。随着海湾地区和沙特阿拉伯国家人们可任意支配收入的增加和旅游业的发展,带动了这一地区化妆品市场的增长。曾经一度使用的天然油皂也逐渐被外国品牌的液体皂和浴用凝胶所代替。驱动这一地区化妆品和香水增长的主要国家是富油区的沙特阿拉伯和阿拉伯联合酋长国的一些海湾国家——科威特、巴林和卡塔尔,这些国家的经济增长主要是由石油支配。此外,商场和美容保健中心的繁荣也反映出海湾国家化妆品和香水的消费在世界上也处于领先地位。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号