Spontaneous obliteration of a pseudo-aneurysm complicating an aortic homograft

Pseudoaneurysm formation after aortic homograft replacement in patients with active endocarditis is a common observation and usually occurs at the site of a former abscess or paravalvular leak in case of prosthetic valve endocarditis. A 53-year-old man with prosthetic endocarditis underwent aortic valve homograft replacement and developed a pseudoaneurysm at the right and noncoronary aortic sinus which was documented by Doppler echocardiography. Follow-up examination ten months after operation unexpectedly revealed a complete obliteration of the previously echo free space between the homograft and the native aortic root and, thus, spontaneous obliteration of the pseudoaneurysm.     

A novel, one-pot method for the synthesis of dimeric and monomeric phthalocyanine silicon complexes from free-base phthalocyanines

A novel method for the synthesis of dimeric and monomeric phthalocyanine silicon complexes using a one-pot method, from tetra-substituted free-base phthalocyanines in the presence of HSiCl₃ at room temperature, is described. Silation was carried out using different bases and the reaction time and the order of addition of the chemicals were varied. It was found that by changing the reaction conditions, it was possible to synthesize either monomers or dimeric complexes with direct Si–Si bonds, selectively.     

可再分散聚合物粉末改性瓷砖胶微的结构及其与宏观性能的联系

介绍对新拌和硬化状态下经可再分散聚合物粉末改性的砂浆微结构进行定量研究的一种新方法。数字化光学、荧光和电子显微镜的复合运用,可以观察到砂浆在新拌状态下的不同组成,如特定的聚合物组分、空隙、水泥相和填料。试验结果表明,砂浆在施工和硬化过程中各微小部分是有差别的,包括各种相的富集或耗损。这些微结构不均匀性的出现说明微结构对砂浆体系的物理性能可以产生关键影响。可再分散胶粉对迁移的抵抗性说明聚合物改性砂浆在强度、内聚性、粘结性和柔性等方面保持了均匀性。     

Children's Mental Health in Times of Economic Recession: Replication and Extension of the Family Economic Stress Model in Finland.

This study evaluated the applicability of the family economic stress model (FESM) in understanding the influences of economic hardship on child mental health during a nationwide economic recession in Finland. The information was gathered from 527 triads of 12-year-olds and their mothers and fathers from a population sample. The structural equation models showed that the FESM fit the data well, indicating its generalizability in Finnish society. The results confirmed that a reduction in disposable family income constitutes a risk for child mental health through increased economic pressure and negative changes in parental mental health, marital interaction, and parenting quality. Controlling the children's prerecession mental health substantiated that economic hardship can lead to deterioration in children's mental health. Alternative models based on fully recursive analyses revealed reciprocal influences between parents and their children over time: Children's prerecession mental health problems predicted compromised parenting, which in turn contributed to children's internalizing and externalizing symptoms during the recession. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Laboratory experiments on backscattering from regolith samples

The investigation of the backscattering peak has applications in the surface texture characterization of asteroids and planetary surfaces. Laboratory experiments are important because they give an opportunity for systematic variation and comparison of samples. A backscattering experiment from regolith samples, which uses a laser light source and a beam splitter to reach the smallest phase angles, is presented. Measurements at zero and small phase angles for Sahara sand and meteorite rocks are made, and the preliminary results are presented in comparison with the phase curve observed for asteroid 69 Hesperia. The results are applicable to the further interpretation of the coherent backscattering opposition effect.     

Exploring the molecular forces within and between CbsA S-layer proteins using single molecule force spectroscopy

We used single molecule atomic force microscopy (AFM) to gain insight into the molecular forces driving the folding and assembly of the S-layer protein CbsA. Force curves recorded between tips and supports modified with CbsA proteins showed sawtooth patterns with multiple force peaks of 58+/-26pN that we attribute to the unfolding of alpha-helices, in agreement with earlier secondary structure predictions. The average unfolding force increased with the pulling speed but was independent on the interaction time. Force curves obtained for CbsA peptides truncated in their C-terminal region showed similar periodic features, except that fewer force peaks were seen. Furthermore, the average unfolding force was 83+/-45pN, suggesting the domains were more stable. By contrast, cationic peptides truncated in their N-terminal region showed single force peaks of 366+/-149pN, presumably reflecting intermolecular electrostatic bridges rather than unfolding events. Interestingly, these large intermolecular forces increased not only with pulling speed but also with interaction time. We expect that the intra- and intermolecular forces measured here may play a significant role in controlling the stability and assembly of the CbsA protein.     

Comparison of homology models and X-ray structures of the nuclear receptor CAR: assessing the structural basis of constitutive activity

The constitutive androstane receptor (CAR) possesses an intrinsic basal activity whose structural basis has been analysed during the last decade. Recently, we published a homology model of the CAR ligand binding domain (LBD) based on the X-ray structures of the closely related pregnane X (PXR) and vitamin D (VDR) receptor. A detailed analysis of the homology model and molecular dynamics (MD) simulations afforded us to propose a potential mechanism underlying the constitutive activity of CAR. Almost simultaneously, X-ray structures of human and mouse CAR LBD were released. In the present study, a detailed analysis and comparison of homology model and X-ray structures is carried out in order to evaluate the quality and reliability of our homology modelling procedure. The hypothesis of the constitutive activity which we proposed on the basis of our modelling results was tested for consistency with the crystal structures. In addition, the features stated to be essential for the basal activity based on the X-ray data were investigated by means of molecular dynamics simulations. Our results show that the homology modelling procedure was able to predict the CAR LBD structure with high accuracy. Structural features that have been revealed as critical for constitutive activity in the model are also observed in the X-ray structures. Furthermore, the MD simulations of the CAR X-ray structures and a detailed analysis of other NRs clarify the role of distinct structural features that have been assigned an important role for the constitutive activity.