Platypnoea-orthodeoxia syndrome due to a right-to-left interatrial shunt following pneumonectomy.

A 62-year-old man presents with breathlessness 6 months following right pneumonectomy for lung adenocarcinoma. Previous investigations had not yielded a diagnosis and his symptoms were progressing. The patient described worsened symptoms when stood up (platypnoea), with profound hypoxia until laid supine (orthodeoxia). Platypnoea-orthodeoxia syndrome due to a right-to-left interatrial shunt was diagnosed on contrast-enhanced transoesophageal echocardiography with the patient undergoing successful percutaneous patent foramen ovale closure. Patent foramen ovale is often asymptomatic with a population prevalence of around 20%-30%. Anatomical shifts postpneumonectomy can open, or worsen a previously closed interatrial communication leading to right-to-left shunting of blood. Platypnoea-orthodeoxia is under-recognised, impairing quality of life and patient outcome. Investigations can be falsely reassuring, or poorly sensitive for the causative pathology. Percutaneous closure is safe with high success rates and this case highlights the need for a high index of suspicion for shunts, particularly in postpneumonectomy patients.

Long-wave infrared polarimetric cluster-based vehicle detection.

The sensory perception of other vehicles in cluttered environments is an essential component of situational awareness for a mobile vehicle. However, vehicle detection is normally applied to visible imagery sequences, while in this paper we investigate how polarized, infrared imagery can add additional discriminatory power. Using knowledge about the properties of the objects of interest and the scene environment, we have developed a polarimetric cluster-based descriptor to detect vehicles using long-wave infrared radiation in the range of 8-12 µm. Our approach outperforms both intensity and polarimetric image histogram descriptors applied to the infrared data. For example, at a false positive rate of 0.01 per detection window, our cluster approach results in a true positive rate of 0.63 compared to a rate of 0.05 for a histogram of gradient descriptor trained and tested on the same dataset. In conclusion, we discuss the potential of this new approach in comparison with state-of-the-art infrared and conventional video detection.

Oxygen Delivery on Medical Wards.

Oxygen is used widely used on all medical wards. It is a drug and should be prescribed. There are known problems with over and under delivery of oxygen to patients. Through national audits and recording baseline data locally, compliance with prescribing is low. This has potentially serious patient safety issues. This quality improvement project attempted to improve oxygen prescribing and subsequent dose adjusting on various medical wards. Monitoring showed a transient improvement but this was not sustained. As a result of this project further research will be put into developing the electronic observation chart to set parameters for target saturations.

Bimodal distribution of performance in discriminating major/minor modes.

This study investigated the abilities of listeners to classify various sorts of musical stimuli as major vs minor. All stimuli combined four pure tones: low and high tonics (G5 and G6), dominant (D), and either a major third (B) or a minor third (B[symbol: see text]). Especially interesting results were obtained using tone-scrambles, randomly ordered sequences of pure tones presented at ≈15 per second. All tone-scrambles tested comprised 16 G's (G5's + G6's), 8 D's, and either 8 B's or 8 B[symbol: see text]'s. The distribution of proportion correct across 275 listeners tested over the course of three experiments was strikingly bimodal, with one mode very close to chance performance, and the other very close to perfect performance. Testing with tone-scrambles thus sorts listeners fairly cleanly into two subpopulations. Listeners in subpopulation 1 are sufficiently sensitive to major vs minor to classify tone-scrambles nearly perfectly; listeners in subpopulation 2 (comprising roughly 70% of the population) have very little sensitivity to major vs minor. Skill in classifying major vs minor tone-scrambles shows a modest correlation of around 0.5 with years of musical training.

The gas-phase equilibrium structures of Si8O12(OSiMe3)8 and Si8O12(CHCH2)8.

The equilibrium molecular structure of Si(8)O(12)(OSiMe(3))(8) has been determined in the gas phase by electron diffraction (GED). With OSi-containing substituents on the cage silicon atoms, this molecule contains a moiety, which would, if reproduced in a periodic manner, yield a zeolite-type structure. Extensive ab initio calculations were used to identify two conformers of this molecule, with D(4) and D(2) point-group symmetries; the D(4)-symmetric conformer was approximately 1.2 kJ mol(-1) lower in energy. With 132 atoms in each conformer, this is one of the largest studies to be undertaken using gas electron diffraction. Semiempirical molecular-dynamics (SE-MD) calculations were used to give amplitudes of vibration, vibrational distance corrections (differences between interatomic distances in the equilibrium structure and the vibrationally averaged distances that are given directly by the diffraction data), and anharmonic constants. The structure of Si(8)O(12)(CHCH(2))(8) has also been determined by GED. Calculations showed that the vinyl groups are fairly unhindered and rotate between three minimum-energy positions. Ultimately, all possible combinations of the vinyl groups in these low-energy positions were accounted for in the GED model.

Characterization of protein detergent complexes by NMR, light scattering, and analytical ultracentrifugation.

Bottlenecks in expression, solubilization, purification and crystallization hamper the structural study of integral membrane proteins (IMPs). Successful crystallization is critically dependent on the purity, stability and oligomeric homogeneity of an IMP sample. These characteristics are in turn strongly influenced by the type and concentration of the detergents used in IMP preparation. By utilizing the techniques and analytical tools we earlier developed for the characterization of protein-detergent complexes (PDCs) [21], we demonstrate that for successful protein extraction from E. coli membrane fractions, the solubilizing detergent associates preferentially to IMPs rather than to membrane lipids. Notably, this result is contrary to the generally accepted mechanism of detergent-mediated IMP solubilization. We find that for one particular member of the family of proteins studied (E. coli receptor kinases, which is purified in mixed multimeric states and oligomerizes through its transmembrane region), the protein oligomeric composition is largely unaffected by a 10-fold increase in protein concentration, by alteration of micelle properties through addition of other detergents to the PDC sample, or by a 20-fold variation in the detergent concentration used for solubilization of the IMP from the membrane. We observed that the conditions used for expression of the IMP, which impact protein density in the membrane, has the greatest influence on the IMP oligomeric structure. Finally, we argue that for concentrating PDCs smaller than 30 kDa, stirred concentration cells are less prone to over-concentration of detergent and are therefore more effective than centrifugal ultrafiltration devices.