Visually precise,low-damage,single-cell spatial manipulation with single-pixel resolution

The analysis of single living cells, including intracellular delivery and extraction, is essential for monitoring their dynamic biochemical processes and exploring intracellular heterogeneity. However, owing to the 2D view in bright-field microscopy and optical distortions caused by the cell shape and the variation in the refractive index both inside and around the cells, achieving spatially undistorted imaging for high-precision manipulation within a cell is challenging. Here, an accurate and visual system is developed for single-cell spatial manipulation by correcting the aberration for simultaneous bright-field triple-view imaging. Stereo information from the triple view enables higher spatial resolution that facilitates the precise manipulation of single cells. In the bright field, we resolved the spatial locations of subcellular structures of a single cell suspended in a medium and measured the random spatial rotation angle of the cell with a precision of ±5°. Furthermore, we demonstrated the visual manipulation of a probe to an arbitrary spatial point of a cell with an accuracy of <1 pixel. This novel system is more accurate and less destructive for subcellular content extraction and drug delivery.

We achieved the low-damage spatial puncture of single cells at specific visual points with an accuracy of <65 nm.     

Preparation and proton conductivity of poly(N‐methylbenzimidazole) doped with acid

To increase the solubility and film forming ability of polybenzimidazole (PBI), poly(N‐methylbenzimidazole) (PNMBI) with different degrees of methylation was synthesized. Chemical structure, degree of substitution, and solubility of PNMBI was studied. PNMBI is easier to be doped with acid than PBI. The basicity of PNMBI was improved with the introduction of methyl groups on the imidazole moiety. Effects of methylation degree, H₃PO₄ content and temperature on proton conductivity of PNMBI doped H₃PO₄ was studied. Proton conductivity of H₃PO₄ doped PNMBI‐1.2 membranes increases with increasing doping level. Temperature dependence of proton conductivity of H₃PO₄ doped PNMBI‐1.2 membranes follows the Arrhenius law. With an increase in the degree of substitution, proton conductivity of H₃PO₄ doped PNMBI decreases dramatically. The proton transport mechanism was also discussed. The proton conductivity of PNMBI/H₃PO₄ is mainly contributed by proton hopping or Grotthuss mechanism. Copyright © 2004 John Wiley & Sons, Ltd.     

Four New Nortriterpenoids from Phlomis umbrosa

Four new 28‐noroleanane‐derived spirocyclic triterpenoids, compounds 1 – 4 , were isolated from the rhizomes of Phlomis umbrosa. Their structures were elucidated on the basis of 1D‐ and 2D‐NMR analyses, in combination with high‐resolution MS experiments.     

用双表面活性剂为共模板合成中孔分子筛MCM-48

利用水热法以非离子表面活性剂聚乙二醇辛基苯基醚和阳离子表面活性剂十六烷基三甲基溴化铵为共模板合成了中孔分子筛MCM-48.实验中发现利用较强的范德华力和氢键,聚乙二醇辛基苯基醚可在很大程度上降低合成MCM-48所需阳离子表面活性剂的用量,且利于制备有序性好、骨架聚合度高、稳定性好的MCM-48.通过调节聚乙二醇辛基苯基醚与十六烷基三甲基溴化铵的比例,可得到不同物相结构的分子筛.     

“双一流”背景下高等农业院校有机化学基础课程教学新模式的构建及实践

The crop science of Sichuan Agricultural University is an authorized first-class discipline. As the strategic supporting department for innovative talent cultivation in agriculture and forestry major, we are facing a long-term challenge in reforming the teaching mode for basic course-organic chemistry and cultivating talented students with solid basic knowledge and strong sense of innovation. Herein a thorough survey was performing to establish the executable teaching programs for this course during the "Double-First Class Universities Plan" period. A multidimensional teaching resource library for organic chemistry course was also constructed. The new classroom teaching mode "Interest cultivation-Creative thought development-Autonomous and Cooperative learning", along with a stepwise practice teaching mode "Foundation skills-Integrated application-Innovative trial" was proposed and practiced among thirty-five majors including agriculture, forestry and veterinary, to improve the quality for innovative talent cultivation and support our first-class discipline construction. This research could probably serve as a reference for congeneric agricultural university.     

羟乙基皂仁胶水溶胶和凝胶体系流变性的研究——不含交联剂溶胶体系的粘度

研究了羟乙基皂仁胶水溶胶体系的粘度对浓度、温度和切变速率的依赖性。溶胶的表观粘度进行了非牛顿校正,其表观粘度的切变速率依赖性可用幂律模型描述。采用Spencer-Dillon方程求得的体系零切粘度与浓度的关系可用Onogi公式描述。对于溶剂和较稀溶液,温度对粘度的影响可用Andrade公式描述,但对较浓溶液,此式不再适用。     

纳米氧化铝微柱富集-等离子体发射光谱法测定植物中痕量稀土元素

以负载了1-苯基-3-甲基-4-苯甲酰基-吡唑酮[5](PMBP)的纳米氧化铝为微柱吸附材料，采用等离子体原子发射光谱法(ICP-AES)，系统地研究了其在动态条件下对稀土离子Sc^3 、Y^3 和La^3 的吸附性能，并确定了最佳吸附及解脱条件。实验结果表明：在pH为4．5时，分析物均可被上述吸附材料定量吸附；用0．5moL／L盐酸溶液可将吸附在微柱上的稀土离子完全解脱。本法对Sc^3 、Y^3 和La^3 的检出限分别为0．16、0.19和0．39μg／L；相对标准偏差(RSD)分别为2．7％、3．2％和1．6％(n=9，C=0．5mg／L)。方法应用于植物标样中痕量Sc、Y和La的测定，其测定值与标样值吻合很好。     

Continuous electrophoretic separation of106Ru species in sea water and uptake of the separated fractions by sea algae

¹⁰⁶Ru chloro and nitrosyl-nitrato complexes in sea water were separated into several species by continuous electrophoresis on a filter paper curtain. Biological uptake experiments were carried out on sea algae Fucus virsoides with fractionated¹⁰⁶Ru chloro and nitrosyl-nitrato complex species in sea water. The biological uptake of¹⁰⁶Ru chloro complex species was about 8 times higher than the uptake of¹⁰⁶Ru nitrosyl-nitrato species. Electrophoretically most mobile electrically positively charged cationic species in both systems also showed about 8 times higher biological uptake than the most mobile negatively charged anionic species. A close relation of the biological uptake to the sign of the electrical charge and the electrophoretic mobility of the species is demonstrated. The results are discussed with respect to possible danger to the biological environment as a consequence of the aging of ruthenium species in sea water resulting from¹⁰⁶Ru waste disposal to the sea from a nuclear reprocessing plant. On leave of absence from the National Institute of Radiological Sciences, 9-1, 4-chome, Anagawa, Chiba-shi, Japan, on a fellowship from The Science and Technology Agency of the Japanese Govemment.     

Nanosized aluminum nitride hollow spheres formed through a self-templating solid-gas interface reaction

Nanosized aluminum nitride hollow spheres were synthesized by simply heating aluminum nanoparticles in ammonia at 1000 °C. The as-synthesized sphere shells are polycrystalline with cavity diameters ranging from 15 to 100 nm and shell thickness from 5 to 15 nm. The formation mechanism can be explained by the nanoscale Kirkendall effect, which results from the difference in diffusion rates between aluminum and nitrogen. The Al nanoparticles served as both reactant and templates for the hollow sphere formation. The effects of precursor particle size and temperature were also investigated in terms of product morphology. Room temperature cathode luminescence spectrum of the nanosized hollow spheres showed a broad emission band centered at 415 nm, which is originated from oxygen related luminescence centers. The hollow structure survived a 4-h heat treatment at 1200 °C, exhibiting excellent thermal stability.     

Online Separation and Preconcentration of Gold and Palladium on Amidinothiourea Immobilized Glass Bead for Interference-Free Flame Atom Absorption Spectrometry Determination

Amidinothiourea immobilized glass bead (AGB) was applied as the microcolumn packing for the flow-injection online separation and preconcentration of Au(III) and Pd(II) coupled with FAAS determination. The peak-area absorbance (A) and the peak-height absorbance (H) were all used as the evaluating modes. Au(III) and Pd(II) in 0.50 M HCl solution were absorbed onto AGB completely and then eluted into AAS with thiourea solution. Base metal ions with a concentration of 2.0 mg/mL and anions with a concentration of 20.0 mg/mL caused no interference in the determination of Au(III) and Pd(II). The LODs of Au(III) and Pd(II) for a preconcentration time of 60 s with a sampling flow rate of 5.0 mL/min for 0.20 μg/mL of Au(III) and 0.30 μg/mL of Pd(II) were 2.7 and 6.5 ng/mL with the H mode and 4.6 and 10.2 ng/mL with the A mode, respectively. The RSD of seven replicate determinations of 0.20 μg/mL of Au(III) and 0.30 μg/mL of Pd(II) were 0.018 and 0.024 for the H mode and 0.013 and 0.018 for the A mode, respectively. The method was successfully applied to the determination of Au and Pd in real samples. __________ From Zhurnal Analiticheskoi Khimii, Vol. 60, No. 10, 2005, pp. 1023–1029. Original English Text Copyright ? 2005 by Liu, Pu, Su. The text was submitted by the authors in English.