人外周血CD4+ T细胞F-actin的超分辨SIM成像

通过合成lifeact序列,将其克隆到pEGFP-C1载体上,构建了pEGFP-C1-Lifeact质粒,转染原代CD4+T细胞,实现对CD4+T细胞F-actin的荧光标记,结合超分辨3D-SIM荧光成像技术,研究人外周血CD4+T细胞F-actin的精细结构,并对其动力学过程进行连续观察。结果表明,CD4+T细胞F-actin分布在细胞膜周围,处于解聚和聚合的动态平衡状态,与普通荧光显微镜相比,超分辩SIM成像F-actin结构更加清晰,分辨率提高2~4倍。     

Subparticle ultrafast spectrum imaging in 4D electron microscopy

Single-particle imaging of structures has become a powerful methodology in nanoscience and molecular and cell biology. We report the development of subparticle imaging with space, time, and energy resolutions of nanometers, femtoseconds, and millielectron volts, respectively. By using scanning electron probes across optically excited nanoparticles and interfaces, we simultaneously constructed energy-time and space-time maps. Spectrum images were then obtained for the nanoscale dielectric fields, with the energy resolution set by the photon rather than the electron, as demonstrated here with two examples (silver nanoparticles and the metallic copper-vacuum interface). This development thus combines the high spatial resolution of electron microscopy with the high energy resolution of optical techniques and ultrafast temporal response, opening the door to various applications in elemental analysis as well as mapping of interfaces and plasmonics.     

基于折射补偿的水下结构光三维测量系统

针对结构光技术在水下三维测量中的应用,提出了一种基于折射补偿的水下结构光三维测量方法。考虑到水下三维测量时,由于光线在不同介质交界处发生折射,采用平面网格靶标对系统进行陆上标定的结果不能直接应用,必须进行折射补偿,补偿被测物体在CCD摄像机靶面上成像点的像素坐标,按所建立的水下三维测量模型进行测量。通过实验证明,本文的折射补偿方法有效地克服了折射对水下三维测量的影响,实现了水下结构光高精度三维测量。     

颜色编码结构光三维测量方法

文章对目前各种颜色编码结构光法进行了系统论述,介绍了基于时间编码、空间编码、直接编码的各种颜色编码方法的原理,分析了颜色编码结构光法在三维物体测量工程技术中应用的优缺点,并简述了颜色编码结构光三维测量方法的发展前景。     

Asymmetric illumination contrast: a method of image formation for video light microscopy

Images with high resolution and exceptionally broad gray scale can be obtained by the application of video contrast enhancement to an optimized procedure for imaging transparent objects with oblique rays of illumination. This technique is simple to set up. A conventional microscope with a light source whose position can be adjusted and a video camera with controls for gain and black level are the only essential components. Features such as high resolution, optical sectioning, control of contrast, and operation under low light intensity make this technique preferable, in several instances, to currently used video microscopy techniques.     

1 alpha, 25-Dihydroxyvitamin D3 nuclear receptors in pituitary

Specific binding of 1 alpha,25-dihydroxyvitamin D(3) was found in nuclear and cytosol fractions of the bovine pituitary. For nuclear binding. the dissociation constant was 0.1 namomole per liter, and maximum binding was 104 femtomoles per milligram of protein. In competition studies, 25-hydroxyvitamin D(3) was 300 times weaker than 1 alpha,25-dihydroxyvitamin D(3). The existence of high-affinity sites supports a physiologic role for 1 alpha,25-dihydroxyvitamin D(3) in the pituitary.     

三维激光扫描成像系统在森林计测中的应用

该文介绍了三维激光扫描成像系统的组成、工作原理、仪器的性能指标及软件功能.通过在甘肃省小陇山林业局的试验,总结了三维激光扫描成像系统进行精准测树的流程、内业数据处理方法、提取各种测树因子的方法、测量立木材积以及树冠体积的方法.结果表明:使用三维激光扫描成像系统可以获取树木的立体模型,得到某些传统方法难以获得的数据,如树冠体积、表面积等,并且可以随意重复量测;通过扫描获得的树木材积可以替代传统的区分求积方法,建立材积表不再需要大量伐树;使用立木扫描模型解决了树冠测量的难题.因此,将三维激光扫描成像系统作为精准测树工具,是一种切实可行的方法.     

Structure of the human dopamine D3 receptor in complex with a D2/D3 selective antagonist

Dopamine modulates movement, cognition, and emotion through activation of dopamine G protein-coupled receptors in the brain. The crystal structure of the human dopamine D3 receptor (D3R) in complex with the small molecule D2R/D3R-specific antagonist eticlopride reveals important features of the ligand binding pocket and extracellular loops. On the intracellular side of the receptor, a locked conformation of the ionic lock and two distinctly different conformations of intracellular loop 2 are observed. Docking of R-22, a D3R-selective antagonist, reveals an extracellular extension of the eticlopride binding site that comprises a second binding pocket for the aryl amide of R-22, which differs between the highly homologous D2R and D3R. This difference provides direction to the design of D3R-selective agents for treating drug abuse and other neuropsychiatric indications.     

Optical projection tomography as a tool for 3D microscopy and gene expression studies

Current techniques for three-dimensional (3D) optical microscopy (deconvolution, confocal microscopy, and optical coherence tomography) generate 3D data by "optically sectioning" the specimen. This places severe constraints on the maximum thickness of a specimen that can be imaged. We have developed a microscopy technique that uses optical projection tomography (OPT) to produce high-resolution 3D images of both fluorescent and nonfluorescent biological specimens with a thickness of up to 15 millimeters. OPT microscopy allows the rapid mapping of the tissue distribution of RNA and protein expression in intact embryos or organ systems and can therefore be instrumental in studies of developmental biology or gene function.     

Atomic-scale chemical imaging of composition and bonding by aberration-corrected microscopy

Using a fifth-order aberration-corrected scanning transmission electron microscope, which provides a factor of 100 increase in signal over an uncorrected instrument, we demonstrated two-dimensional elemental and valence-sensitive imaging at atomic resolution by means of electron energy-loss spectroscopy, with acquisition times of well under a minute (for a 4096-pixel image). Applying this method to the study of a La(0.7)Sr(0.3)MnO3/SrTiO3 multilayer, we found an asymmetry between the chemical intermixing on the manganese-titanium and lanthanum-strontium sublattices. The measured changes in the titanium bonding as the local environment changed allowed us to distinguish chemical interdiffusion from imaging artifacts.     

Direct imaging of live human platelets by flash x-ray microscopy

A 100-nanosecond pulse of long-wavelength x-rays was used to produce high-resolution stop-motion images of living human platelets. Although some aspects of the structure conform to those seen in dehydrated specimens, novel features are apparent. The technique should permit detailed stop-motion examination of the interaction of platelets with their surrounding medium as well as exploration of the phagocytic and secretory activities of a wide variety of other cells.     

基于三维激光扫描成像系统的树冠生物量研究

林业中对树冠进行准确量测一直都难以实现,对树冠体积、表面积的估测也多是将树冠近似为规则几何体,所得到的数据偏差较大,使与树冠相关的一些研究受到限制.该文将三维激光扫描成像系统运用于立木测量,建立立木三维模型,通过对模型进行量测获取包括树冠体积、表面积等各种测树因子.以此为基础,运用非线性回归方法建立树冠体积、表面积回归方程,相关系数都在0.95左右.利用树冠体积、表面积回归模型,可以用传统林业调查数据推算树冠的体积表面积,可以使与树冠相关的估测、研究得到较好的结果.同时该文将树冠因子引入生物量模型,建立包含树冠体积、表面积的生物量模型,获得了较传统CAR模型更好的效果,可作为生物量估测的基本模型.     

丁腈橡胶与氯丁橡胶并用生产彩印胶辊

研究了丁腈橡胶（NBR）与氯丁橡胶（CR）并用生产彩印胶辊的方法。实验表明此方法比传统的橡塑并用法简单，适合在小型胶厂推广应用，并用后胶料的综合性能较好，提高了产品的耐热，耐化学腐蚀性能，同时也降低了成本，还可根据CR的并用份数调整产品的硬度。     

Human perception of illumination with pulsed ultrahigh-frequency electromagnetic energy

A psychophysical study of the perception of "sound" induced by illumination with pulse-modulated, ultrahigh-frequency electromagnetic energy indicated that perception was primarily dependent upon peak power and secondarily dependent upon pulse width. The average power did not significantly affect perception. Perceived characteristics of pitch and timbre appeared to be functions of modulation.     

Two-dimensional imaging of potential waves in electrochemical systems by surface plasmon microscopy

The potential dependence of resonance conditions for the excitation of surface plasmons was exploited to obtain two-dimensional images of the potential distribution of an electrode with high temporal resolution. This method allows the study of spatiotemporal patterns in electrochemical systems. Potential waves traveling across the electrode with a speed on the order of meters per second were observed in the bistable regime of an oscillatory electrochemical reaction. This velocity is close to that of excitation waves in nerve fibers and is far greater than the velocity of reaction-diffusion waves observed in other chemical systems.     

生物法生产25-羟基维生素D3条件优化

[目的]优化25-羟基维生素D3[25(OH)VD_3]的转化条件,提高25(OH)VD3产量。[方法]通过单因素试验和正交试验对菌株UV-FY-141转化生产25(OH)VD_3的条件进行优化。[结果]确定其最佳发酵培养基:葡萄糖15.00g,蛋白胨20.00g,NaCl5.00g,CaCO_32.00g,FeSO_4·7H-2O0.01g,去离子水1000mL。优化后转化条件:发酵初始pH6.5,发酵温度为28℃,发酵时摇床转速为200r/min,发酵时间为72h。在优化条件下,25(OH)VD3产量由原来的9.460mg/L提高到13.130mg/L,提高了38.79%。[结论]采用优化后的转化条件,可显著提高25(OH)VD_3的产量。     

Stimulation of 24,25-dihydroxyvitamin D3 production by 1,25-dihydroxyvitamin D3

Vitamin D-deficient rats produce [(3)H]1,25-dihydroxyvitamin D(3) from [(3)H]25-hydroxyvitamin D(3) regardless of dietary content of calcium or phosphate. A daily dose of 130 picomoles of 1,25-dihydroxyvitamin D(3) for a period of 5 days reduces production of [(3)H]1,25-dihydroxyvitamin D(3) to essentially zero and stimulates production of [(3)H]24,25-dihydroxyvitamin D(3). A daily dose of 325 picomoles of 25-hydroxyvitamin D(3) has a similar but less dramatic effect. On the other hand, 650 picomoles daily of 24,25-dihydroxyvitamin D(3) given to vitamin D-deficient rats had no effect. Thus it appears that 1,25-dihydroxyvitamin D(3) is an important factor in the regulation of kidney metabolism of 25-hydroxyvitamin D(3).