Improved spatial separation of neutral molecules

We have developed and experimentally demonstrated an improved electrostatic deflector for the spatial separation of molecules according to their dipole-moment-to-mass ratio. The device features a very open structure that allows for significantly stronger electric fields as well as for stronger deflection without molecules crashing into the device itself. We have demonstrated its performance using the prototypical OCS molecule and we discuss opportunities regarding improved quantum-state-selectivity for complex molecules and the deflection of unpolar molecules.Comment: 6 figure

Imaging Molecular Structure through Femtosecond Photoelectron Diffraction on Aligned and Oriented Gas-Phase Molecules

This paper gives an account of our progress towards performing femtosecond time-resolved photoelectron diffraction on gas-phase molecules in a pump-probe setup combining optical lasers and an X-ray Free-Electron Laser. We present results of two experiments aimed at measuring photoelectron angular distributions of laser-aligned 1-ethynyl-4-fluorobenzene (C8H5F) and dissociating, laseraligned 1,4-dibromobenzene (C6H4Br2) molecules and discuss them in the larger context of photoelectron diffraction on gas-phase molecules. We also show how the strong nanosecond laser pulse used for adiabatically laser-aligning the molecules influences the measured electron and ion spectra and angular distributions, and discuss how this may affect the outcome of future time-resolved photoelectron diffraction experiments.Comment: 24 pages, 10 figures, Faraday Discussions 17

Aneurysm Ostium Angle: A Predictor of the Need for Stent as Assistance for Endovascular Aneurysm Coiling in Internal Carotid Artery Sidewall Aneurysms

BACKGROUND AND PURPOSE: There is no satisfactory parameter that can predict the need for assistant devices for endovascular aneurysm coiling. Our aim was to evaluate the utility of MOA as a predictor of the need for stent-assisted coiling in ICA sidewall aneurysms

Cell-based expression cloning for identification of polypeptides that hypersensitize mammalian cells to mitotic arrest

Microtubule inhibitors such as Vinblastine and Paclitaxel are chemotherapy agents that activate the mitotic spindle checkpoint, arresting cells in mitosis and leading to cell death. The pathways that connect mitotic arrest to cell death are not well characterized. We developed a mammalian cell-based cDNA cloning method to isolate proteins and protein fragments whose expression inhibits colony formation in the presence of microtubule inhibitors. Understanding how these proteins impact cellular responses to microtubule drugs will lead to better understanding of the biochemical pathways connecting mitotic arrest and cell death in mammalian cells and may provide novel targets that can enhance microtubule inhibitor-mediated chemotherapy

Pituitary-hormone secretion by thyrotropinomas

Hormone secretion by somatotropinomas, corticotropinomas and prolactinomas exhibits increased pulse frequency, basal and pulsatile secretion, accompanied by greater disorderliness. Increased concentrations of growth hormone (GH) or prolactin (PRL) are observed in about 30% of thyrotropinomas leading to acromegaly or disturbed sexual functions beyond thyrotropin (TSH)-induced hyperthyroidism. Regulation of non-TSH pituitary hormones in this context is not well understood. We there therefore evaluated TSH, GH and PRL secretion in 6 patients with up-to-date analytical and mathematical tools by 24-h blood sampling at 10-min intervals in a clinical research laboratory. The profiles were analyzed with a new deconvolution method, approximate entropy, cross-approximate entropy, cross-correlation and cosinor regression. TSH burst frequency and basal and pulsatile secretion were increased in patients compared with controls. TSH secretion patterns in patients were more irregular, but the diurnal rhythm was preserved at a higher mean with a 2.5 h phase delay. Although only one patient had clinical acromegaly, GH secretion and IGF-I levels were increased in two other patients and all three had a significant cross-correlation between the GH and TSH. PRL secretion was increased in one patient, but all patients had a significant cross-correlation with TSH and showed decreased PRL regularity. Cross-ApEn synchrony between TSH and GH did not differ between patients and controls, but TSH and PRL synchrony was reduced in patients. We conclude that TSH secretion by thyrotropinomas shares many characteristics of other pituitary hormone-secreting adenomas. In addition, abnormalities in GH and PRL secretion exist ranging from decreased (joint) regularity to overt hypersecretion, although not always clinically obvious, suggesting tumoral transformation of thyrotrope lineage cells

Constrained pre-equalization accounting for multi-path fading emulated using large RC networks: applications to wireless and photonics communications

Multi-path propagation is modelled assuming a multi-layer RC network with randomly allocated resistors and capacitors to represent the transmission medium. Due to frequency-selective attenuation, the waveforms associated with each propagation path incur path-dependent distortion. A pre-equalization procedure that takes into account the capabilities of the transmission source as well as the transmission properties of the medium is developed. The problem is cast within a Mixed Integer Linear Programming optimization framework that uses the developed nominal RC network model, with the excitation waveform customized to optimize signal fidelity from the transmitter to the receiver. The objective is to match a Gaussian pulse input accounting for frequency regions where there would be pronounced fading. Simulations are carried out with different network realizations in order to evaluate the sensitivity of the solution with respect to changes in the transmission medium mimicking the multi-path propagation. The proposed approach is of relevance where equalization techniques are difficult to implement. Applications are discussed within the context of emergent communication modalities across the EM spectrum such as light percolation as well as emergent indoor communications assuming various modulation protocols or UWB schemes as well as within the context of space division multiplexing

Prednisolone is associated with a worse lipid profile than hydrocortisone in patients with adrenal insufficiency

Objective: Prednisolone is used as glucocorticoid replacement therapy for adrenal insufficiency (AI). Recent data indicate that its use in AI is associated with low bone mineral density. Data on risk factors for cardiovascular disease in patients with AI treated with prednisolone are scarce, despite this condition being the predominant cause of excess mortality. We aimed to address this question using real-world data from the European Adrenal Insufficiency Registry (EU-AIR). // Design/methods: EU-AIR, comprising of 19 centres across Germany, the Netherlands, Sweden and the UK, commenced enrolling patients with AI in August 2012. Patients receiving prednisolone (3–6 mg/day, n = 50) or hydrocortisone (15–30 mg/day, n = 909) were identified and grouped at a ratio of 1:3 (prednisolone:hydrocortisone) by matching for gender, age, duration and type of disease. Data from baseline and follow-up visits were analysed. Data from patients with congenital adrenal hyperplasia were excluded. // Results: Significantly higher mean ± S.D. total (6.3 ± 1.6 vs 5.4 ± 1.1 mmol/L; P = 0.003) and low-density lipoprotein (LDL) cholesterol levels (3.9 ± 1.4 vs 3.2 ± 1.0 mmol/L; P = 0.013) were identified in 47 patients on prednisolone vs 141 receiving hydrocortisone at baseline and at follow-up (P = 0.005 and P = 0.006, respectively). HbA1c, high-density lipoprotein and triglyceride levels, body mass index, systolic and diastolic blood pressure and waist circumference were not significantly different. // Conclusions: This is the first matched analysis of its kind. Significantly higher LDL levels in patients receiving prednisolone relative to hydrocortisone could predict a higher relative risk of cardiovascular disease in the former group