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1.
随着CCD等光电成像器件和计算机技术的迅猛发展,数字全息显微技术不断发展成熟起来,以其非接触、定量、三维成像等特点广泛应用于医学影像领域。本文综述了数字全息显微技术在生物医学方面的发展;比较了数字全息显微技术与其它显微技术在生物医学成像方面的优缺点;分析总结了不同全息显微影像信息系统;论述了不同光源结构对数字全息显微成像效果的重要影响以及相应算法补偿;列举了数字全息显微在生物医学中的最新应用。  相似文献   

2.
荧光显微镜凭借其非接触、无损伤、可实时探测生物样品内部等优点,成为生命科学研究中不可或缺的工具,但是Abbe光学衍射极限的存在限制了其对亚细胞尺度生化过程的进一步研究。作为突破光学衍射极限的远场光学显微镜,受激辐射耗尽(Stimulated Emission Depletion,STED)超分辨荧光显微术,因其超高时空分辨率和三维层析能力,成为备受关注的新型成像和分析表征工具。本文结合我们课题组在STED显微成像研究方面的工作,综述了近年来STED显微成像技术的研究进展及其在细胞成像中的应用。  相似文献   

3.
本文综述了近年来单细胞成像分析方法的研究进展。重点讨论了图像细胞光度测量、荧光显微成像、红外(近红外)与拉曼显微成像、磁共振成像和扫描探针显微镜成像等技术,并展望了单细胞成像的发展前景。  相似文献   

4.
以L-酪氨酸为原料,经过酯化、磺酰化、mitsunobu反应、水解、催化氢化等几步反应制得盐酸替罗非班,目标产物的化学结构经1H-NMR、IR、MS等确证,总收率为33%。  相似文献   

5.
单克隆抗体SZ-2特异作用于人血小板和巨核细胞,测定10例正常人血小板SZ-2结合位点数为15200±4100/血小板,KD值0.66±0.33nM。SZ-2所识别的抗原对糜蛋白酶敏感,但对神经氨酸酶不敏感,亲和层析技术证明其为血小板糖蛋白Ib(GPIb)。SZ-2与其它抗GPIb单克隆抗体不同,它不仅抑制瑞斯托霉素诱导的血小板聚集,而且也抑制Ⅰ型胶原和血小板活化因子诱导的血小板聚集,并抑制上述诱导剂引起的血小板5-HT和βTG释放。  相似文献   

6.
随着人类对可持续能源的需求不断增长,先进的表征方法在能源材料研究等领域变得越来越重要。借助X射线成像技术,我们可以从二维和三维角度实时获取能源材料的形貌、结构和应力变化信息。此外,借助高穿透性X射线和高亮度同步辐射源,设计原位实验,可以获取充放电过程中样品的定性和定量变化信息。本文综述了基于同步加速器的X射线成像技术及其相关应用,讨论了包括X射线投影成像、透射式X射线显微成像、扫描透射X射线显微成像、X射线荧光显微成像以及相干衍射成像等几种主要的X射线成像技术在能源材料研究领域的应用,展望了未来X射线成像的应用前景及发展方向。  相似文献   

7.
正Angew.Chem.Int.Ed.2016,55,392~396绣线菊醇、绣线菊内酯B、绣线菊碱C和D是中国科学院昆明植物研究所郝小江课题组从蔷薇科绣线菊属植物(Spiraea japonica L.f)分离出的代表性的阿替生型二萜和阿替生型二萜生物碱.该类成分多具有抗炎、抗血小板聚集、  相似文献   

8.
为得到抗血小板聚集活性更好的丹皮酚衍生物,在2-位苄基取代的基础上,以丹皮酚为原料,经苄基化,肟化及醚化合成了5个新型的苄基丹皮酚肟衍生物(4a~4e),其结构经1H NMR, IR和HR-MS(ESI)表征。体外抗血小板聚集活性结果表明:4a~4e(AIR: 13.87~21.50%)的活性均强于对照药阿司匹林(AIR: 11.14%),其中化合物4c(AIR: 20.76%)和4e(AIR: 21.50%)的抗血小板聚集活性显著,具备进一步研究的潜力。   相似文献   

9.
相干拉曼散射显微术(Coherent Raman Scattering Microscopy)是一类植根于拉曼散射的光学显微成像方法,主要包含相干反斯托克斯拉曼散射(Coherent Anti-Stokes Raman Scattering,CARS)和受激拉曼散射(Stimulated Raman Scattering,SRS)两种方法.CARS/SRS显微术通过探测目标分子特定的振动来提供成像所需的衬度,通过非线性光学过程大大提高了检测的灵敏度,同时本征地具备三维成像能力.CARS和SRS显微术可以对脂类等不易被标记的物质成像,还可以很好地通过选择振动光谱,对生物体内特定小分子物质如药物等,以及生物大分子如核酸、蛋白质等进行无需标记的成像,因此成为极有潜力的活体(invivo)成像手段.本文主要介绍了CARS和SRS显微术的基本原理、实验操作及其在化学和生命科学中的应用.  相似文献   

10.
在生物医学领域,对纳米尺寸级别的微小生物目标进行精确定位研究具有非常重要的意义,而光学显微成像技术为此提供了强有力的工具。 光学显微成像技术受到光学衍射极限的限制,难以分辨尺寸在衍射极限(<200 nm)以下的生物结构,无法直接获取微小生物结构信息,阻碍了生物医学的进一步发展。 近年来,随着纳米分辨显微成像技术的出现,新型荧光探针的开发、成像系统与设备的不断发展及成像算法不断完善地深入结合,促进了光学衍射极限以下尺寸微观目标的研究。 基于单分子定位的超分辨荧光显微成像(SMLM)包括光激活定位成像(PALM)与随机光学重构超分辨成像(STORM),将有机荧光探针与超分辨光学显微成像技术紧密结合在一起,荧光探针的光物理性质直接决定着超分辨成像结果的好坏。 因此,设计不同性能的荧光探针可以实现超精细结构的不同超分辨成像,为研究其生物学功能提供了有力的工具。 本文着重围绕基于SMLM的原理、有机荧光探针的设计要求、用于SMLM的荧光探针种类及其生物应用等方面进行总结综述,指出了单分子定位成像上存在的不足,并对其发展方向进行了展望,希望为对超分辨成像研究感兴趣或初涉该领域的研究者提供成像理论与探针设计方面的帮助。  相似文献   

11.
利用手持技术改进测定乙醇分子结构实验   总被引:1,自引:0,他引:1  
利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。  相似文献   

12.
13.
由于石化行业的生产需要,其材质的使用具有多样性和广泛性,经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识,根据光谱仪的测试能力及标样的采集,实现了一个或几个元素测量范围的扩展,并对其测量的影响因素进行了研究。  相似文献   

14.
The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.  相似文献   

15.
The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.  相似文献   

16.

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

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17.
实验教学目的是从解决实际问题出发,以实验技术训练和实验设计思想培养为目标。介绍了将单一的物质分配系数测定实验改进为综合实验,提高了实验效果及实验资源利用率。  相似文献   

18.
The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.  相似文献   

19.
Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.  相似文献   

20.
非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。  相似文献   

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