Pial and arachnoid welding for restoration of normal cord anatomy after excision of intramedullary spinal cord tumors.

A significant postoperative problem in patients undergoing excision of intramedullary tumors is painful dysesthesiae, attributed to various causes, including edema, arachnoid scarring and cord tethering. The authors describe a technique of welding the pia and arachnoid after the excision of intramedullary spinal cord tumors used in seven cases. Using a fine bipolar forcep and a low current, the pial edges of the myelotomy were brought together and welded under saline irrigation. A similar method was used for closing the arachnoid while the dura was closed with a running 5-0 vicryl suture. Closing the pia and arachnoid restores normal cord anatomy after tumor excision and may reduce the incidence of postoperative painful dysesthesiae.

Recent decrease in the prevalence of congenital heart defects in europe.

OBJECTIVES: To examine trends in the prevalence of congenital heart defects (CHDs) in Europe and to compare these trends with the recent decrease in the prevalence of CHDs in Canada (Quebec) that was attributed to the policy of mandatory folic acid fortification. STUDY DESIGN: We used data for the period 1990-2007 for 47 508 cases of CHD not associated with a chromosomal anomaly from 29 population-based European Surveillance of Congenital Anomalies registries in 16 countries covering 7.3 million births. We estimated trends for all CHDs combined and separately for 3 severity groups using random-effects Poisson regression models with splines. RESULTS: We found that the total prevalence of CHDs increased during the 1990s and the early 2000s until 2004 and decreased thereafter. We found essentially no trend in total prevalence of the most severe group (group I), whereas the prevalence of severity group II increased until about 2000 and decreased thereafter. Trends for severity group III (the most prevalent group) paralleled those for all CHDs combined. CONCLUSIONS: The prevalence of CHDs decreased in recent years in Europe in the absence of a policy for mandatory folic acid fortification. One possible explanation for this decrease may be an as-yet-undocumented increase in folic acid intake of women in Europe following recommendations for folic acid supplementation and/or voluntary fortification. However, alternative hypotheses, including reductions in risk factors of CHDs (eg, maternal smoking) and improved management of maternal chronic health conditions (eg, diabetes), must also be considered for explaining the observed decrease in the prevalence of CHDs in Europe or elsewhere.

Atrioventricular septal defects among infants in Europe: a population-based study of prevalence, associated anomalies, and survival.

OBJECTIVE: To describe the epidemiology of chromosomal and non-chromosomal cases of atrioventricular septal defects in Europe. METHODS: Data were obtained from EUROCAT, a European network of population-based registries collecting data on congenital anomalies. Data from 13 registries for the period 2000-2008 were included. RESULTS: There was a total of 993 cases of atrioventricular septal defects, with a total prevalence of 5.3 per 10,000 births (95% confidence interval 4.1 to 6.5). Of the total cases, 250 were isolated cardiac lesions, 583 were chromosomal cases, 79 had multiple anomalies, 58 had heterotaxia sequence, and 23 had a monogenic syndrome. The total prevalence of chromosomal cases was 3.1 per 10,000 (95% confidence interval 1.9 to 4.3), with a large variation between registers. Of the 993 cases, 639 cases were live births, 45 were stillbirths, and 309 were terminations of pregnancy owing to foetal anomaly. Among the groups, additional associated cardiac anomalies were most frequent in heterotaxia cases (38%) and least frequent in chromosomal cases (8%). Coarctation of the aorta was the most common associated cardiac defect. The 1-week survival rate for live births was 94%. CONCLUSION: Of all cases, three-quarters were associated with other anomalies, both chromosomal and non-chromosomal. For infants with atrioventricular septal defects and no chromosomal anomalies, cardiac defects were often more complex compared with infants with atrioventricular septal defects and a chromosomal anomaly. Clinical outcomes for atrioventricular septal defects varied between regions. The proportion of termination of pregnancy for foetal anomaly was higher for cases with multiple anomalies, chromosomal anomalies, and heterotaxia sequence.

A receptor-like kinase mutant with absent endodermal diffusion barrier displays selective nutrient homeostasis defects.

The endodermis represents the main barrier to extracellular diffusion in plant roots, and it is central to current models of plant nutrient uptake. Despite this, little is known about the genes setting up this endodermal barrier. In this study, we report the identification and characterization of a strong barrier mutant, schengen3 (sgn3). We observe a surprising ability of the mutant to maintain nutrient homeostasis, but demonstrate a major defect in maintaining sufficient levels of the macronutrient potassium. We show that SGN3/GASSHO1 is a receptor-like kinase that is necessary for localizing CASPARIAN STRIP DOMAIN PROTEINS (CASPs)--major players of endodermal differentiation--into an uninterrupted, ring-like domain. SGN3 appears to localize into a broader band, embedding growing CASP microdomains. The discovery of SGN3 strongly advances our ability to interrogate mechanisms of plant nutrient homeostasis and provides a novel actor for localized microdomain formation at the endodermal plasma membrane.

Point defects and texture of Pd1-xInx sputtered intermetallic thin films

Pd1-xInx thin films (0.4 < x < 0.56) were prepared by radio frequency sputtering from a multi-zone target. The properties of these Hume-Rothery alloys were studied by X-ray diffractometry, electron probe microanalysis and scanning tunneling microscopy. The diffraction spectra were analyzed to obtain the intensity ratio of the (100) superlattice line to the (200) normal line, together with the variations of the lattice constant. The results ape explained quantitatively by a model based on point defects, i.e. Pd vacancies in In-rich films and Pd antisite atoms in Pd-rich films. In-rich films grow preferentially in the [100] direction while Pd-rich films grow preferentially in the [110] direction. The grains in indium-rich sputtered films appear to be enclosed in an atomically thick, indium-rich layer. The role of texture and the influence of point defects on electrical resistivity is also reported. (C) 1996 Elsevier Science Limited.

Light induced defects in thermal annealed hydrogenated amorphous silicon

The metastable defects of a-Si:H samples annealed at temperatures in the 300-550°C range have been studied by photothermal deflection spectroscopy (PDS). The light-soaked samples show an increase in optical absorption in the 0.8 to 1.5 eV range. The metastable defect density decreases when the annealing temperature increases, while the defect density increases. This decrease in the metastable defect density shows an almost linear correlation with the decrease in the hydrogen content of the samples, determined by IR transmission spectroscopy and thermal desorption spectroscopy.

Crystal defects and spin tunneling in single crystals of Mn12 clusters

The question addressed in this paper is that of the influence of the density of dislocations on the spin tunneling in Mn12 clusters. We have determined the variation in the mosaicity of fresh and thermally treated single crystals of Mn12 by analyzing the widening of low angle x-ray diffraction peaks. It has also been well established from both isothermal magnetization and relaxation experiments that there is a broad distribution of tunneling rates which is shifted to higher rates when the density of dislocations increases.