Long-term Effect of Bariatric Surgery on the Use of Levothyroxine and Thyroid Levels

BACKGROUND: The aim of this study was to evaluate the effect of bariatric surgery on the defined daily dose of levothyroxine (DDD LT4), thyroid-stimulating hormone (TSH), and free thyroxine (fT4) in female patients with hypothyroidism until 48 months after surgery. METHODS: A retrospective observational study of hypothyroid patients who underwent bariatric surgery. Changes in DDD LT4, TSH, and fT4 over a 48 month period after surgery were analyzed. RESULTS: Thirty-seven patients were included: 27 Roux-en-Y gastric bypass (RYGB), 6 sleeve gastrectomy (SG), 3 adjustable gastric band, and 1 one anastomosis gastric bypass. The median DDD LT4 decreased from 125 µg at baseline to 100 µg 12 months after surgery. From 24 to 48 months after surgery, the median DDD LT4 was stable at 125 µg. Most dose adjustments occurred during the first 24 months after surgery. In the time period of 24-48 months after surgery, the dose remained stable in 73.1% of the RYGB patients and in 60.0% of the SG patients. After 48 months in the RYGB group, no significant change in TSH and fT4 levels was observed. CONCLUSIONS: Bariatric surgery led to frequent dose adjustments during the first 2 years after surgery. However, 24-48 months after surgery in the majority of patients, the dosage remained stable. No significant change in TSH and fT4 was observed 48 months after RYGB. In the first 2 years after surgery, clinicians should frequently monitor TSH and fT4 for individual dose adjustment of levothyroxine. Thereafter, the frequency of monitoring may be decreased

The origin of the runaway high-mass X-ray binary HD153919/4U1700-37

Based on its Hipparcos proper motion, we propose that the high-mass X-ray binary HD153919/4U1700-37 originates in the OB association Sco OB1. At a distance of 1.9 kpc the space velocity of 4U1700-37 with respect to Sco OB1 is 75 km/s. This runaway velocity indicates that the progenitor of the compact X-ray source lost about 7 Msun during the (assumed symmetric) supernova explosion. The system's kinematical age is about 2 +/- 0.5 million years which marks the date of the supernova explosion forming the compact object. The present age of Sco OB1 is <8 Myr; its suggested core, NGC 6231, seems to be somewhat younger (~5 Myr). If HD153919/4U1700-37 was born as a member of Sco OB1, this implies that the initially most massive star in the system terminated its evolution within 30 Msun. With these parameters the evolution of the binary system can be constrained.Comment: 6 pages, latex, 3 embedded ps figures, to appear in A&

Evaluation of the flame propagation within an SI engine using flame imaging and LES

This work shows experiments and simulations of the fired operation of a spark ignition engine with port-fuelled injection. The test rig considered is an optically accessible single cylinder engine specifically designed at TU Darmstadt for the detailed investigation of in-cylinder processes and model validation. The engine was operated under lean conditions using iso-octane as a substitute for gasoline. Experiments have been conducted to provide a sound database of the combustion process. A planar flame imaging technique has been applied within the swirl- and tumble-planes to provide statistical information on the combustion process to complement a pressure-based comparison between simulation and experiments. This data is then analysed and used to assess the large eddy simulation performed within this work. For the simulation, the engine code KIVA has been extended by the dynamically thickened flame model combined with chemistry reduction by means of pressure dependent tabulation. Sixty cycles have been simulated to perform a statistical evaluation. Based on a detailed comparison with the experimental data, a systematic study has been conducted to obtain insight into the most crucial modelling uncertainties

Закономерности распределения аномальных концентраций гелия в палеозойских отложениях Донбасса

Підвищені концентрації гелію у вільних і розчинених газах у вугільно-породному масиві Донбасу приурочені до зон зчленування Донбасу з Приазовським і Воронезьким кристалічними масивами і Головної антикліналі. Диз'юнктивні тектонічні порушення глибокого закладення служили, ймовірно, шляхами транзиту гелію від кристалічних порід фундаменту в палеозойські відклади Донбасу, і підвищений вміст гелію може служити індикатором шляхів транзиту газів з глибоких горизонтів Донецького вугільного басейну.Elevated concentrations of helium in free and dissolved gases in coal-rock mass of the Donets Coal Basin are confined to the junction zones of the Donets Coal Basin with the Priazovie and Voronezh crystalline core-areas and Glavnaya (Principal) Anticline. Deep-laid disjunctive dislocations were probably the ways for transit of helium from crystalline basement rocks into Paleozoic deposits of the Basin. Elevated concentrations of helium can also serve as indicators of the ways for transit of gases from deep levels of the Donets Coal Basin

Prognostic value of patient-reported quality of life for survival in oesophagogastric cancer:Analysis from the population-based POCOP study

BACKGROUND: Accumulating evidence of trials demonstrates that patient-reported health-related quality of life (HRQoL) at diagnosis is prognostic for overall survival (OS) in oesophagogastric cancer. However, real-world data are lacking. Moreover, differences in disease stages and tumour-specific symptoms are usually not taken into consideration. The aim of this population-based study was to assess the prognostic value of HRQoL, including tumour-specific scales, on OS in patients with potentially curable and advanced oesophagogastric cancer. METHODS: Data were derived from the Netherlands Cancer Registry and the patient reported outcome registry (POCOP). Patients included in POCOP between 2016 and 2018 were stratified for potentially curable (cT1-4aNallM0) or advanced (cT4b or cM1) disease. HRQoL was measured with the EORTC QLQ-C30 and the tumour-specific OG25 module. Cox proportional hazards models assessed the impact of HRQoL, sociodemographic and clinical factors (including treatment) on OS. RESULTS: In total, 924 patients were included. Median OS was 38.9 months in potentially curable patients (n = 795) and 10.6 months in patients with advanced disease (n = 129). Global Health Status was independently associated with OS in potentially curable patients (HR 0.89, 99%CI 0.82-0.97), together with several other HRQoL items: appetite loss, dysphagia, eating restrictions, odynophagia, and body image. In advanced disease, the Summary Score was the strongest independent prognostic factor (HR 0.75, 99%CI 0.59-0.94), followed by fatigue, pain, insomnia and role functioning. CONCLUSION: In a real-world setting, HRQoL was prognostic for OS in patients with potentially curable and advanced oesophagogastric cancer. Several HRQoL domains, including the Summary Score and several OG25 items, could be used to develop or update prognostic models

Discovery of a bow shock around Vela X-1

We report the discovery of a symmetric bow shock around the well-known high-mass X-ray binary (HMXB) Vela X-1. Wind bow shocks are a ubiquitous phenomenon around OB-runaway stars, but now such a structure is found around a HMXB. The presence of a bow shock indicates that the system has a high (supersonic) velocity with respect to the interstellar medium. From the symmetry of the bow shock, the direction of motion and, moreover, the origin and age of the system can be derived. Our observation supports Blaauw's scenario for the formation of an OB-runaway star by the supernova explosion of the binary companion.Comment: 14 pages, latex (including style file), 3 postscript figures, ApJ Letters, in pres

Cutoff value determines the performance of a semi-quantitative immunochemical faecal occult blood test in a colorectal cancer screening programme

BACKGROUND: The cutoff of semi-quantitative immunochemical faecal occult blood tests (iFOBTs) influences colonoscopy referrals and detection rates. We studied the performance of an iFOBT (OC-Sensor) in colorectal cancer (CRC) screening at different cutoffs. METHODS: Dutch screening participants, 50-75 years of age, with average CRC risk and an iFOBT value >or=50 ng ml(-1) were offered colonoscopy. The detection rate was the percentage of participants with CRC or advanced adenomas (>or=10 mm, >or=20% villous, high-grade dysplasia). The number needed to scope (NNTScope) was the number of colonoscopies to be carried out to find one person with CRC or advanced adenomas. RESULTS: iFOBT values >or=50 ng ml(-1) were detected in 526 of 6157 participants (8.5%) and 428 (81%) underwent colonoscopy. The detection rate for advanced lesions (28 CRC and 161 with advanced adenomas) was 3.1% (95% confidence interval: 2.6-3.5%) and the NNTScope was 2.3. At 75 ng ml(-1), the detection rate was 2.7%, the NNTScope was 2.0 and the CRC miss rate compared with 50 ng ml(-1) was <5% (N=1). At 100 ng ml(-1), the detection rate was 2.4% and the NNTScope was <2. Compared with 50 ng ml(-1), up to 200 ng ml(-1) CRC miss rates remained at 16% (N=4). CONCLUSIONS: Cutoffs below the standard 100 ng ml(-1) resulted in not only higher detection rates of advanced lesions but also more colonoscopies. With sufficient capacity, 75 ng ml(-1) might be advised; if not, up to 200 ng ml(-1) CRC miss rates are acceptable compared with the decrease in performed colonoscopies

Probing Single-Electron Spin Decoherence in Quantum Dots using Charged Excitons

We propose to use optical detection of magnetic resonance (ODMR) to measure the decoherence time T_{2} of a single electron spin in a semiconductor quantum dot. The electron is in one of the spin 1/2 states and a circularly polarized laser can only create an optical excitation for one of the electron spin states due to Pauli blocking. An applied electron spin resonance (ESR) field leads to Rabi spin flips and thus to a modulation of the photoluminescence or, alternatively, of the photocurrent. This allows one to measure the ESR linewidth and the coherent Rabi oscillations, from which the electron spin decoherence can be determined. We study different possible schemes for such an ODMR setup, including cw or pulsed laser excitation.Comment: 8 pages, 7 figures. Proceedings of the PASPS3 conference, Santa Barbara, CA (USA). To appear in the Journal of Superconductivit

Excitons in a Photosynthetic Light-Harvesting System: A Combined Molecular Dynamics/Quantum Chemistry and Polaron Model Study

The dynamics of pigment-pigment and pigment-protein interactions in light-harvesting complexes is studied with a novel approach which combines molecular dynamics (MD) simulations with quantum chemistry (QC) calculations. The MD simulations of an LH-II complex, solvated and embedded in a lipid bilayer at physiological conditions (with total system size of 87,055 atoms) revealed a pathway of a water molecule into the B800 binding site, as well as increased dimerization within the B850 BChl ring, as compared to the dimerization found for the crystal structure. The fluctuations of pigment (B850 BChl) excitation energies, as a function of time, were determined via ab initio QC calculations based on the geometries that emerged from the MD simulations. From the results of these calculations we constructed a time-dependent Hamiltonian of the B850 exciton system from which we determined the linear absorption spectrum. Finally, a polaron model is introduced to describe quantum mechanically both the excitonic and vibrational (phonon) degrees of freedom. The exciton-phonon coupling that enters into the polaron model, and the corresponding phonon spectral function are derived from the MD/QC simulations. It is demonstrated that, in the framework of the polaron model, the absorption spectrum of the B850 excitons can be calculated from the autocorrelation function of the excitation energies of individual BChls, which is readily available from the combined MD/QC simulations. The obtained result is in good agreement with the experimentally measured absorption spectrum.Comment: REVTeX3.1, 23 pages, 13 (EPS) figures included. A high quality PDF file of the paper is available at http://www.ks.uiuc.edu/Publications/Papers/PDF/DAMJ2001/DAMJ2001.pd