黄河水中镉(Ⅱ)与悬浮粒子液──固界面交换反应的研究

本文研究了黄河悬浮粒子与镉（Ⅱ）相互作用的离子交换率（％）—pH曲线，以及河水中赖氨酸存在下对该曲线的影响。主要结果有；（1）镉以Cd（OH）+形式在悬浮粒子上进行阳离子交换，在天然pH下（8．0×8．5），镉离子交换率接近最大值；（2）镉离子浓度由8．9×10－6mol·L－1增加到2×8．9×10－6mol．L－1时，离子交换率降低；（3）浓度为6．8×10－6mol·L－1的赖氨酸对提高离子交换率起促进作用；（4）交换剂为转化沙的镉离子交换率比未转化沙小；（5）海水、金沙江水中悬浮粒子对镉的吸附弱于黄河水。

Colorectal cancer lymph node staining by activated carbon nanoparticles suspension in vivo or methylene blue in vitro

AIM:To investigate whether activated carbon nanoparticles suspension(ACNS) or methylene blue(MB) can increase the detected number of lymph nodes in colorectal cancer.METHODS:Sixty-seven of 72 colorectal cancer patients treated at our hospital fulfilled the inclusion criteria of the study which was conducted from December 2010 to February 2012.Seven patients refused to participate.Eventually,60 patients were included,and randomly assigned to three groups(20 in each group):ACNS group(group A),MB group(group B) and non-stained conventional surgical group(group C).In group A,patients received subserosal injection of 1 mL ACNS in a 4-quadrant region around the mass.In group B,the main artery of specimen was identified and isolated after the specimen was removed,and 2 mL MB was slowly injected into the isolated,stretched and fixed vessel.In group C,no ACNS and MB were injected.All the mesentery lymph nodes were isolated and removed systematically by visually inspecting and palpating the adipose tissue.RESULTS:No difference was observed among the three groups in age,gender,tumor location,tumor diameter,T-stage,degree of differentiation,postoperative complications and peritoneal drainage retention time.The total number of detected lymph nodes was 535,476 and 223 in the three groups,respectively.The mean number of detected lymph nodes per patient was significantly higher in group A than in group C(26.8 ± 8.4 vs 12.2 ± 3.2,P < 0.001).Similarly,there were significantly more lymph nodes detected in group B than in group C(23.8 ± 6.9 vs 12.2 ± 3.2,P < 0.001).However,there was no significant difference between group A and group B.There were 50,46 and 32 metastatic lymph nodes dissected in 13 patients of group A,10 patients of group B and 11 patients of group C,without significant differences among the three groups.Eleven of the 60 patients had insufficient number of detected lymph nodes(< 12).Only one patient with T 4a rectal cancer had 10 lymph nodes detected in group B,the other 10 patients were all from group C.Based on the different diameter categories,the number of detected lymph nodes in groups A and B was significantly higher than in group C.However,there was no statistically significant difference between group A and group B.The metastatic lymph nodes were not significant different among the three groups.Similarly,tumor location,T stage and tumor differentiation did not affect the staining results.Body mass index was a minor influencing factor in the two different staining methods.The stained lymph nodes can easily be identified from the mesenteric adipose tissues,and the staining time for lymph nodes was not significantly different compared with unstained group.None of the patients in groups A and B had drug-related complications.CONCLUSION:Both activated carbon nanoparticles suspension in vivo and methylene blue in vitro can be used as tracers to increase the detected number of lymph nodes in colorectal cancer.

Analysis of Percolation of the Stabilized Suspensions of TiO2 and SiO2 Nanoparticles in Soil Columns Simulating Landfill Layers

It studied the behavior of transport and stability of TiO2 and SiO2 nanoparticles suspensions percolating through soil columns aiming at simulating municipal waste landfills covering soil layers performance. Experimental columns were constructed with landfill soils and water suspensions with nanoparticles percolation runs were carried out. The experimental columns were constructed with 100 mm and 200 mm of diameter and height, respectively. Outlet concentrations were measured along the percolation time using ICP-OES and nanoparticles tracking analyzer. It was observed that SiO2 nanoparticles acts as a stabilizer of TiO2 nanoparticles suspensions and promotes its transport through the soil columns, which simulates the conditions of the controlled landfills layers. The interaction of the suspensions of SiO2 nanoparticles with nanoparticles of TiO2, promote a high stability of the emulsions, which confers the high zeta potential present in SiO2 suspensions, promoting greater mobility and transport through the soil columns. The experimental results demonstrated that TiO2 nanoparticles were kept suspended, even after 10 days, which indicates good stability. It was observed that both TiO2 and SiO2 were kept in suspensions with negligible nanoparticles clustering and decantation. It was confirmed that the TiO2 and SiO2 of the outflow of soil columns are strongly affected by the soil pH, organic carbon and clay content of the soils. It was observed that the soil columns behave as a retention barrier for both TiO2 and SiO2 nanoparticles.

Effect of Charge, Size and Temperature on Stability of Charged Colloidal Nano Particles

Molecular simulation of charged colloidal suspension is performed in NVT canonical ensemble using Monte Carlo method and primitive model. The well-known Derjaguin-Landau-Verwey- Overbeek theory is applied to account for effective interactions between particles. Effect of temperature, valance of micro-ions and the size of colloidal particles on the phase stability of the solution is investigated. The results indicate that the suspension is more stable at higher temperatures. On the other hand, for a more stable suspension to exist, lower micro- ion valance is favorable. For micro-ions of higher charge the number of aggregates and the number of particle in each of aggregate on average is higher. However for the best of our results larger colloidal particle are less stable. Comparing the results with theoretical formula considering the influence of surface curvature shows qualitative consistency.

Self-suspended Pure Polydiacetylene Nanoparticles with Selective Response to Lysine and Arginine

We demonstrate a very convenient access to self-suspended pure poly（10,12-pentacosadiynoic acid） （PDA） nanoparticles （NPs） simply by adding the ethanol solution of diacetylene monomer to water, followed by UV irradiation. The as-obtained PDA NPs are of high purity because no any initiator, catalyst or stabilizer was used during the whole process. The stabilizer-free PDA NPs are stable in the aqueous suspension. Due to the high purity and stability, the PDA NPs can respond sensitively and selectively to lysine and arginine among 18 kinds of water soluble natural amino acids; without the competitive interaction from the stabilizer, the sensitivity was enhanced.