磷酸铋体系共振光散射法测定药物中的铋

1引言铋是治疗胃溃疡、胃酸过多等常用药中的活性成分,它能在溃疡面形成铋-蛋白质凝固膜,保护溃疡面免受胃酸和蛋白酶的侵蚀,促进愈合。铋的含量是胃药质量控制的一项重要指标。目前测定胃药中铋的方法主要有氢化物原子吸收光谱法、络合滴定法、萃取光度法等。因共振光散射(RLS     

线极化摇摆场中的束流动力学

对线极化摇摆场中,在有引导磁场或四极磁场时的电子轨迹特性、束流包络特性进行了解析分析和数值分析,推得了线极化摇摆场中的梯度漂移解析表达式,借助于Bogoliubov的非线性渐近法和奇异摄动法得到的解析分析结果与数值分析结果很好地吻合。     

Study of the interaction of aglycon of daunorubicin with human serum albumin by spectroscopy and modeling

The interaction between aglycon of daunorubicin (DNR-A) and human serum albumin (HSA) was investigated using fluorescence quenching and modeling. Results shown that fluorescence quenching of HSA by DNR-A resulted from the formation of DNR-A-HSA complex. The quenching constants were determined via measurement of the binding affinity between DNR-A and HSA using the Stern-Volmer equation. The thermodynamic parameters DeltaG, DeltaH, DeltaS and the binding distance r were calculated. Furthermore, SFS and UV spectra suggested that the complex changed the conformation of HSA and that hydrophobic interactions played a major role in DNR-A-HSA association, which was in good agreement with the results of the modeling study. Moreover, the SFS technique was successfully applied to determine the total proteins in biology samples with satisfactory results.     

Large Interlayer Distance and Heteroatom-Doping of Graphite Provide New Insights into the Dual-Ion Storage Mechanism in Dual-Carbon Batteries

Dual-ion batteries (DIBs) is a promising technology for large-scale energy storage. However, it is still questionable how material structures affect the anion storage behavior. In this paper, we synthesis graphite with an ultra-large interlayer distance and heteroatomic doping to systematically investigate the combined effects on DIBs. The large interlayer distance of 0.51 nm provides more space for anion storage, while the doping of the heteroatoms reduces the energy barriers for anion intercalation and migration and enhances rapid ionic storage at interfaces simultaneously. Based on the synergistic effects, the DIBs composed of carbon cathode and lithium anode afford ultra-high capacity of 240 mAh g⁻¹ at current density of 100 mA g⁻¹. Dual-carbon batteries (DCBs) using the graphite as both of cathode and anode steadily cycle 2400 times at current density of 1 A g⁻¹. Hence, this work provides a reference to the strategy of material designs of DIBs and DCBs.     

On 3-Submanifolds of S^3 Which Admit Complete Spanning Curve Systems

Let M be a compact connected 3-submanifold of the 3-sphere S~3 with one boundary component F such that there exists a collection of n pairwise disjoint connected orientable surfaces S = {S_1, ···, S_n} properly embedded in M, ?S = {?S_1, ···, ?S_n}is a complete curve system on F. We call S a complete surface system for M, and ?S a complete spanning curve system for M. In the present paper, the authors show that the equivalent classes of complete spanning curve systems for M are unique, that is, any complete spanning curve system for M is equivalent to ?S. As an application of the result,it is shown that the image of the natural homomorphism from the mapping class group M(M) to M(F) is a subgroup of the handlebody subgroup Hn.     

银鲳脾脏和肾脏组织细胞体外培养研究

为探究银鲳脾脏和肾脏组织细胞体外培养条件, 本研究采用组织块培养法对银鲳脾脏和肾脏组织进行原代培养. 实验选用DMEM/F-12、M199和DMEM等作为基础培养基, 在其中分别添加体积分数为10％、15％、20％的胎牛血清, 并添加青链霉素及庆大霉素以防细菌污染. 结果表明: 银鲳脾脏和肾脏组织在胎牛血清体积分数为20％的DMEM/F-12培养基中贴壁最好, 迁出细胞的种类最多, 细胞生长速度最快. 其中脾脏组织共迁出6种不同的细胞, 分别为: 免疫细胞、基质细胞、上皮样细胞、成纤维样细胞、造血灶和未知细胞; 肾脏组织共迁出3种细胞, 分别为: 上皮样细胞、巨噬细胞和成纤维样细胞.     

Development of an oxidative dehydrogenation-based fluorescent probe for Cu and its biological imaging in living cells

Based on a boron dipyrromethene (BODIPY) derivative containing an N, O and S tridentate ligand, a Cu²⁺ fluorescent probe BTCu was developed. The detection mechanism was verified as Cu²⁺-promoted oxidative dehydrogenation of an amine moiety, leading to a formation of a fluorescent Cu⁺-Schiff base complex. Free BTCu exhibited a maximum absorption wavelength at 496 nm, and a very weak maximum emission at 511 nm. Upon addition of various metals ions, it showed large fluorescence enhancement toward Cu²⁺ (417-fold in MeCN and 103-fold in MeCN/HEPES solution, respectively) with high selectivity. The detection limits are as low as 1.74 × 10⁻⁸ M and 4.96 × 10⁻⁸ M in the two different solutions, respectively. And BTCu could work in a wide pH range with an extraordinary low pK_a of 1.21 ± 0.06. Using fluorescence microscopy, the probe was shown to be capable of penetrating into living cells and imaging intracellular Cu²⁺ changes.     

Spectroscopic and Molecular Modeling Studies of the Interaction Between 4′-O-(α-L-Oleandrosyl)daunorubicin and Human Serum Albumin and Its Analytical Application

4′-O-(α-L-Oleandrosyl)daunorubicin (ODNR) is a disaccharide analogue of daunorubicin with potent antitumor activity against leukemia cell line K562 cells and colon cancer cell line SW620 cells. In this paper, the binding interaction of ODNR with human serum albumin (HSA) was investigated under simulative physiological conditions by fluorescence spectroscopy in combination with UV absorption spectroscopy and molecular modeling method. A strong fluorescence quenching reaction of ODNR to HSA was observed and the quenching mechanism was suggested as static quenching according to the Stern-Volmer equation. The binding constants (K) at different temperatures as well as thermodynamic parameters, enthalpy change (ΔH) and entropy change (ΔS), were calculated according to relevant fluorescent data and Van’t Hoff equation. The hydrophobic interaction was a predominant intermolecular force in order to stabilize the complex, which was in agreement with the results of molecular modeling study. In addition, the effects of other ions on the binding constants were also studied. Moreover, the synchronous fluorescence technique was successfully employed to determine the total proteins in serum, urine and saliva samples at room temperature under the optimum conditions with a wide linear range and satisfactory results.     

超细荧光聚合物纳米微球的制备

合成了具有较高荧光量子产率(0.69)和良好光稳定性的可聚合荧光染料单体,该荧光染料的光稳定性高于商品化的染料罗丹明B。 通过氧化还原引发剂引发乳液聚合制备了超细荧光聚合物纳米微球,将染料分子共价连接在聚合物链上。 使用非离子表面活性剂Triton X-100作为乳化剂、甲基丙烯酸甲酯(MMA)作为单体和助乳化剂,制备的超细纳米微球平均粒径为22 nm,而不加MMA时制备出的纳米微球平均粒径在150 nm左右。 由于微球表面带有苄氯基团,为进一步的微球功能化提供了途径。     

Tunable mechanical properties of MWCNT–glass fiber fabric reinforced epoxy composites by controlling MWCNTs dispersing conditions

A novel, simple and cost-effective method, which is capable of easily tailoring the dispersion of multi-walled carbon nanotubes (MWCNTs), was developed here to fabricate the MWCNT–glass fiber fabric (MWCNT–GFf) multiscale composites with tunable mechanical properties. MWCNTs were dispersed into the commercial GFfs through the combined effect of the ultrasound and amino silane (AS) firstly, followed by a resin infusion process. By tuning the ultrasonic power and AS concentration, it is possible to control the MWCNTs dispersion level and subsequently mechanical properties of resultant composite. Making use of optimal dispersion conditions, which involves the optimal combination of ultrasonic power and AS concentration, the interlaminar shear strength of MWCNT–GFf reinforced composites was dramatically increased by 40.5%, and the storage modulus in the glassy region and rubbery region was improved by 27.7% and 125.0%, respectively. The work demonstrates the great promise of this novel method toward practical, industrial application in manufacturing fiber-reinforced composites with superior mechanical properties.