The orientation and charge of water at the hydrophobic oil droplet-water interface

We established the charge and structure of the oil/water interface by combining ζ-potential measurements, sum frequency scattering (SFS) and molecular dynamics simulations. The SFS experiments show that the orientation of water molecules can be followed on the oil droplet/water interface. The average water orientation on a neat oil droplet/water interface is the same as the water orientation on a negatively charged interface. pH dependent experiments show, however, that there is no sign of selective adsorption of hydroxide ions. Molecular dynamics simulations, both with and without intermolecular charge transfer, show that the balance of accepting and donating hydrogen bonds is broken in the interfacial layer, leading to surface charging. This can account for the negative surface charge that is found in experiments.     

The perpendicular fundamental v5 of chloroform 12CH35Cl3: high resolution infrared study of the v5 band together with the millimetre-wave rotational spectrum

The infrared spectrum of the perpendicular fundamental v₅ of chloroform around 776 cm^?1 has been studied by applying two high resolution methods. A short range from the central part of the spectrum was measured with a diode laser by using a cold jet sample including chloroform in natural isotopic abundancies. More than 100 rotational lines of ¹²CH³⁵Cl₃ could be assigned. The whole band region was measured by a Fourier transform spectrometer at a resolution of 0.0010cm^?1. In this case an isotopically pure sample of ¹²CH³⁵Cl₃ was used. Starting from the results of the diode laser investigation more than 2000 lines could be assigned with J_max = 91 and K_max = 58. In addition to the infrared spectra, millimetre-wave lines also were measured. A total of 58 lines corresponding to J values 22, 23 and 35 at the excited vibration state v₅ = 1 were assigned and analysed. All the data from three different spectra were simultaneously fitted and, for example, the results v₀ = 775.961 50(3) cm^?1, 98, B₅-B₀ = ?0.180171(22) × 10^?3cm^?1, C₅ ? C₀ = ?0.170 57(15) × 10^?3cm^?1, and (Cζ)₅ = 0.047 5294(11) cm^?1 were obtained.     

Water-Soluble Rhenium Clusters with Triazoles: The Effect of Chemical Structure on Cellular Internalization and the DNA Binding of the Complexes

Here we explore the effect of the nature of organic ligands in rhenium cluster complexes [Re₆Q₈L₆]⁴⁻ (where Q=S or Se, and L=benzotriazole, 1,2,3-triazole or 1,2,4-triazole) on the biological properties of the complexes, in particular on the cellular toxicity, cellular internalization and localization. Specifically, the study describes the synthesis and detailed characterization of the structure, luminescence and electrochemical properties of the four new Re₆ clusters with 1,2,3- and 1,2,4-triazoles. Biological assays of these complexes are also discussed in addition to those with benzotriazole using cervical cancer (HeLa) and immortalized human fibroblasts (CRL-4025) as model cell lines. Our study demonstrates that the presence of hydrophobic and π-bonding rich units such as the benzene ring in benzotriazole significantly enhances cellular internalization of rhenium clusters. These ligands facilitate binding of the clusters to DNA, which results in increased cytotoxicity of the complexes.     

大鼠中风模型的超小氧化铁粒子神经血管成像(英文)

现今诱导血管增生剂在中风后的治疗效应引起了人们的关注.这项工作的一个目的是用短时脑中动脉栓塞大鼠中风模型(MCAO)和磁化率加权成像(SWI)的核磁共振成像(MRI)方法,监测在中风后半月形损伤区新生成的旁侧血管.P904是法国格尔伯实验室生产的超小超顺磁氧化铁粒子弛豫试剂(USPIO).它在低剂量减少T1弛豫时间,适中剂量时减少T2*弛豫时间.实验动物被随机分为3组:中风Sildenafil治疗组(n=6)、中风无治疗对照组(n=5)和无中风无治疗对照组(n=1).在P904注入前后分别进行MRI成像.磁化率加权成像的时间点是:栓塞手术前、栓塞手术后24小时、栓塞手术后两周和四周.结果表明,术后两周,在治疗组中中风严重的动物的缺血区的周边显示了MRI可见的新生血管.结论:在短时脑中动脉栓塞大鼠中风模型中,使用超小超顺磁氧化铁粒子弛豫试剂和7 T高分辨磁化率加权成像能够监测半月形损伤区新生血管的形成.