Wettability and Surface Tension of Amphiphilic Polymer Films: Time‐Dependent Measurements of the Most Stable Contact Angle

The wettability of new amphiphilic block copolymer films is studied by measuring different types of water contact angles (static, receding, advancing, and most stable). The most stable contact angles are used to calculate the surface tensions of the films following the recently developed Marmur–Valal correlation. Most stable contact angles of water in an air‐in‐water system are also measured to study the changes in surface tension over relatively long periods of immersion time. The new approach yields surface tension values that are higher than those calculated by previous methods. The results suggest that reconstruction of the surface takes place at short time scale and continues to occur at long time scale. The responsive character of the polymer films can have implications for their use as biofouling release coatings.     

心尖肥厚性心肌病14例诊断分析

0　引言　心尖肥厚性心肌病 ( AHCM)是肥厚性心肌病的一种亚型 ,占肥厚性心肌病的 2 %～ 2 4 %、[1 ,2 ] .其临床表现为心绞痛和心电图 ST-T改变 ,容易和冠心病 ( CHD)上混淆 .本研究旨在分析心尖肥厚性心肌病的临床特点、诊断和鉴别诊断 ,以减少临床误诊率 .1　对象和方法1 .1　对象　 1 996-0 1 / 1 998-1 2住院的 AHCM患者 1 4(男 1 3,女 1 )例 ,年龄 ( 4 8.93± 9.34 ) ( 32～ 67)岁 .临床表现 :典型心绞痛 9例 ,胸闷 4例 ,无症状 1例 .4例伴高脂血症 ,3例伴高血压 ,7例有吸烟史 ,6例有饮酒史 .临床均以急性心内膜下心肌梗死、心…     

Immune and protective abilities of ubiquitinated and non-ubiquitinated pseudorabies virus glycoproteins

Plasmids encoding ubiquitinated (ubi-) or non-ubiquitinated (non-ubi-) glycoproteins of Pseudorabies virus (PRV) were used for vaccination of pigs. We found that the fusion of ubiquitin to viral glycoproteins increased their degradation in proteasomes in vitro, in which ubiquitin plays a key role. In the animals immunized with the plasmids encoding PRV ubi-glycoproteins and then challenged with PRV, we detected a slightly decreased cellular immune response on days 13 and 19 after immunization and a reduced nasal excretion of infectious virus on day 2 after the challenge. Afterwards, no effect of the ubiquitination of the glycoproteins on humoral or cellular immunity and on excretion of infectious virus was observed. Similarly, no effect of the ubiquitination on protective abilities of PRV glycoproteins was found.     

Exploring the Backbone of Enkephalins To Adjust Their Pharmacological Profile for the δ-Opioid Receptor

The role of each of the four amide bonds in Leu(5)-enkephalin was investigated by systematically and sequentially replacing each with its corresponding trans-alkene. Six Leu(5)-enkephalin analogs based on six dipeptide surrogates and two Met(5)-enkephalin analogs were synthesized and thoroughly tested using a δ-opioid receptor internalization assay, an ERK1/2 activation assay, and a competition binding assay to evaluate their biological properties. We observed that an E-alkene can efficiently replace the first amide bond of Leu(5)- and Met(5)-enkephalin without significantly affecting biological activity. By contrast, the second amide bond was found to be highly sensitive to the same modification, suggesting that it is involved in biologically essential intra- or intermolecular interactions. Finally, we observed that the affinity and activity of analogs containing an E-alkene at either the third or fourth position were partially reduced, indicating that these amide bonds are less important for these intra- or intermolecular interactions. Overall, our study demonstrates that the systematic and sequential replacement of amide bonds by E-alkene represents an efficient way to explore peptide backbones.