Critical care provision after colorectal cancer surgery

Background: Colorectal cancer (CRC) is the 2nd largest cause of cancer related mortality in the UK with 40 000 new patients being diagnosed each year. Complications of CRC surgery can occur in the perioperative period that leads to the requirement of organ support. The aim of this study was to identify pre-operative risk factors that increased the likelihood of this occurring. Methods: This is a retrospective observational study of all 6441 patients who underwent colorectal cancer surgery within the West of Scotland Region between 2005 and 2011. Logistic regression was employed to determine factors associated with receiving postoperative organ support. Results: A total of 610 (9 %) patients received organ support. Multivariate analysis identified age ≥65, male gender, emergency surgery, social deprivation, heart failure and type II diabetes as being independently associated with organ support postoperatively. After adjusting for demographic and clinical factors, patients with metastatic disease appeared less likely to receive organ support (p = 0.012). Conclusions: Nearly one in ten patients undergoing CRC surgery receive organ support in the post operative period. We identified several risk factors which increase the likelihood of receiving organ support post operatively. This is relevant when consenting patients about the risks of CRC surgery

Artifacts at 4.5 and 8.0 um in Short Wavelength Spectra from the Infrared Space Observatory

Spectra from the Short Wavelength Spectrometer (SWS) on ISO exhibit artifacts at 4.5 and 8 um. These artifacts appear in spectra from a recent data release, OLP 10.0, as spurious broad emission features in the spectra of stars earlier than ~F0, such as alpha CMa. Comparison of absolutely calibrated spectra of standard stars to corresponding spectra from the SWS reveals that these artifacts result from an underestimation of the strength of the CO and SiO molecular bands in the spectra of sources used as calibrators by the SWS. Although OLP 10.0 was intended to be the final data release, these findings have led to an additional release addressing this issue, OLP 10.1, which corrects the artifacts.Comment: 14 pages, AASTex, including 5 figures. Accepted by ApJ Letter

Nanotube field of C60 molecules in carbon nanotubes: atomistic versus continuous tube approach

We calculate the van der Waals energy of a C60 molecule when it is encapsulated in a single-walled carbon nanotube with discrete atomistic structure. orientational degrees of freedom and longitudinal displacements of the molecule are taken into account, and several achiral and chiral carbon nanotubes are considered. A comparison with earlier work where the tube was approximated by a continuous cylindrical distribution of carbon atoms is made. We find that such an approximation is valid for high and intermediate tube radii; for low tube radii, minor chirality effects come into play. Three molecular orientational regimes are found when varying the nanotube radius.Comment: 14 pages, 9 figures, accepted for publication in Phys. Rev.

The Nystrom plus Correction Method for Solving Bound State Equations in Momentum Space

A new method is presented for solving the momentum-space Schrodinger equation with a linear potential. The Lande-subtracted momentum space integral equation can be transformed into a matrix equation by the Nystrom method. The method produces only approximate eigenvalues in the cases of singular potentials such as the linear potential. The eigenvalues generated by the Nystrom method can be improved by calculating the numerical errors and adding the appropriate corrections. The end results are more accurate eigenvalues than those generated by the basis function method. The method is also shown to work for a relativistic equation such as the Thompson equation.Comment: Revtex, 21 pages, 4 tables, to be published in Physical Review

Neurologic phenotype of Schimke immuno-osseous dysplasia and neurodevelopmental expression of SMARCAL1

Schimke immuno-osseous dysplasia (OMIM 242900) is an uncommon autosomal-recessive multisystem disease caused by mutations in SMARCAL1 (swi/snf-related, matrix-associated, actin-dependent regulator of chromatin, subfamily a-like 1), a gene encoding a putative chromatin remodeling protein. Neurologic manifestations identified to date relate to enhanced atherosclerosis and cerebrovascular disease. Based on a clinical survey, we determined that half of Schimke immuno-osseous dysplasia patients have a small head circumference, and 15% have social, language, motor, or cognitive abnormalities. Postmortem examination of 2 Schimke immuno-osseous dysplasia patients showed low brain weights and subtle brain histologic abnormalities suggestive of perturbed neuron-glial migration such as heterotopia, irregular cortical thickness, incomplete gyral formation, and poor definition of cortical layers. We found that SMARCAL1 is highly expressed in the developing and adult mouse and human brain, including neural precursors and neuronal lineage cells. These observations suggest that SMARCAL1 deficiency may influence brain development and function in addition to its previously recognized effect on cerebral circulation

Chromosome-Level Genome Assembly for the Angiosperm Silene conica.

The angiosperm genus Silene has been the subject of extensive study in the field of ecology and evolution, but the availability of high-quality reference genome sequences has been limited for this group. Here, we report a chromosome-level assembly for the genome of Silene conica based on Pacific Bioscience HiFi, Hi-C, and Bionano technologies. The assembly produced 10 scaffolds (1 per chromosome) with a total length of 862 Mb and only ∼1% gap content. These results confirm previous observations that S. conica and its relatives have a reduced base chromosome number relative to the genus\u27s ancestral state of 12. Silene conica has an exceptionally large mitochondrial genome (\u3e11 Mb), predominantly consisting of sequence of unknown origins. Analysis of shared sequence content suggests that it is unlikely that transfer of nuclear DNA is the primary driver of this mitochondrial genome expansion. More generally, this assembly should provide a valuable resource for future genomic studies in Silene, including comparative analyses with related species that recently evolved sex chromosomes

When an old star smolders: On the detection of hydrocarbon emission from S-type AGB stars

Polycyclic aromatic hydrocarbons (PAHs) produce characteristic infrared emission bands that have been observed in a wide range of astrophysical environments, where carbonaceous material is subjected to ultraviolet (UV) radiation. Although PAHs are expected to form in carbon-rich AGB stars, they have up to now only been observed in binary systems where a hot companion provides a hard radiation field. In this letter, we present low-resolution infrared spectra of four S-type AGB stars, selected from a sample of 90 S-type AGB stars observed with the infrared spectrograph aboard the Spitzer satellite. The spectra of these four stars show the typical infrared features of PAH molecules. We confirm the correlation between the temperature of the central star and the centroid wavelength of the 7.9 {\mu}m feature, present in a wide variety of stars spanning a temperature range from 3 000 to 12 000 K. Three of four sources presented in this paper extend this relation towards lower temperatures. We argue that the mixture of hydrocarbons we see in these S-stars has a rich aliphatic component. The fourth star, BZ CMa, deviates from this correlation. Based on the similarity with the evolved binary TU Tau, we predict that BZ CMa has a hot companion as well.Comment: 5 pages, 2 figures, 2 table

The Spitzer Spectroscopic Survey of S-type Stars

S-type AGB stars are thought to be in the transitional phase between M-type and C-type AGB stars. Because of their peculiar chemical composition, one may expect a strong influence of the stellar C/O ratio on the molecular chemistry and the mineralogy of the circumstellar dust. In this paper, we present a large sample of 87 intrinsic galactic S-type AGB stars, observed at infrared wavelengths with the Spitzer Space Telescope, and supplemented with ground-based optical data. On the one hand, we derive the stellar parameters from the optical spectroscopy and photometry, using a grid of model atmospheres. On the other, we decompose the infrared spectra to quantify the flux-contributions from the different dust species. Finally, we compare the independently determined stellar parameters and dust properties. For the stars without significant dust emission, we detect a strict relation between the presence of SiS absorption in the Spitzer spectra and the C/O ratio of the stellar atmosphere. These absorption bands can thus be used as an additional diagnostic for the C/O ratio. For stars with significant dust emission, we define three groups, based on the relative contribution of certain dust species to the infrared flux. We find a strong link between group-membership and C/O ratio. We show that these groups can be explained by assuming that the dust-condensation can be cut short before silicates are produced, while the remaining free atoms and molecules can then form the observed magnesium sulfides or the carriers of the unidentified 13 and 20 micron features. Finally, we present the detection of emission features attributed to molecules and dust characteristic to C-type stars, such as molecular SiS, hydrocarbons and magnesium sulfide grains. We show that we often detect magnesium sulfides together with molecular SiS and we propose that it is formed by a reaction of SiS molecules with Mg.Comment: Accepted for publication in A&