2,502 research outputs found
The structure of insulin at the air/water interface: monomers or dimers?
The hydrophobic character of the air/water interface affects the oligomeric composition of insulin. By using interface-specific vibrational sum frequency spectroscopy and calculations of insulin monomer and dimer second-order nonlinear susceptibilities chi(2), we show that insulin monomers segregate to the air/water interface
Probing the atmosphere of a sub-Jovian planet orbiting a cool dwarf
We derive the 0.01 m binned transmission spectrum, between 0.74 and 1.0
m, of WASP-80b from low resolution spectra obtained with the FORS2
instrument attached to ESO's Very Large Telescope. The combination of the fact
that WASP-80 is an active star, together with instrumental and telluric
factors, introduces correlated noise in the observed transit light curves,
which we treat quantitatively using Gaussian Processes. Comparison of our
results together with those from previous studies, to theoretically calculated
models reveals an equilibrium temperature in agreement with the previously
measured value of 825K, and a sub-solar metallicity, as well as an atmosphere
depleted of molecular species with absorption bands in the IR ().
Our transmission spectrum alone shows evidence for additional absorption from
the potassium core and wing, whereby its presence is detected from analysis of
narrow 0.003 m bin light curves (). Further observations with
visible and near-UV filters will be required to expand this spectrum and
provide more in-depth knowledge of the atmosphere. These detections are only
made possible through an instrument-dependent baseline model and a careful
analysis of systematics in the data.Comment: 13 pages, 11 figures, 3 tables. Accepted for publication in MNRA
Science communication research in the German-speaking countries: A content analysis of conference abstracts
The study examines the state of science communication research in the German-speaking countries. Based on a standardized content analysis of all extended abstracts submitted to the annual conferences of the German Communication Association’s science communication division from 2014 to 2018 (N = 141), it describes the respective scholarly community, its research foci and objects. The results indicate that science communication has developed toward a well-established community and marks an institutionalization of the research field. Furthermore, the findings of the content analysis indicate that science communication research in the German-speaking countries shows parallels to international developments in terms of research foci, objects, and analytical models, but also differences regarding theories and methods
Endometrial cancer - reduce to the minimum. A new paradigm for adjuvant treatments?
<p>Abstract</p> <p>Background</p> <p>Up to now, the role of adjuvant radiation therapy and the extent of lymph node dissection for early stage endometrial cancer are controversial. In order to clarify the current position of the given adjuvant treatment options, a systematic review was performed.</p> <p>Materials and methods</p> <p>Both, Pubmed and ISI Web of Knowledge database were searched using the following keywords and MESH headings: "Endometrial cancer", "Endometrial Neoplasms", "Endometrial Neoplasms/radiotherapy", "External beam radiation therapy", "Brachytherapy" and adequate combinations.</p> <p>Conclusion</p> <p>Recent data from randomized trials indicate that external beam radiation therapy - particularly in combination with extended lymph node dissection - or radical lymph node dissection increases toxicity without any improvement of overall survival rates. Thus, reduced surgical aggressiveness and limitation of radiotherapy to vaginal-vault-brachytherapy only is sufficient for most cases of early stage endometrial cancer.</p
Association of Air Pollution with Increased Incidence of Ventricular Tachyarrhythmias Recorded by Implanted Cardioverter Defibrillators
Epidemiologic studies have demonstrated a consistent link between sudden cardiac deaths and particulate air pollution. We used implanted cardioverter defibrillator (ICD) records of ventricular tachyarrhythmias to assess the role of air pollution as a trigger of these potentially life-threatening events. The study cohort consisted of 203 cardiac patients with ICD devices in the Boston metropolitan area who were followed for an average of 3.1 years between 1995 and 2002. Fine particle mass and gaseous air pollution plus temperature and relative humidity were measured on almost all days, and black carbon, sulfate, and particle number on a subset of days. Date, time, and intracardiac electrograms of ICD-detected arrhythmias were downloaded at the patients’ regular follow-up visits (about every 3 months). Ventricular tachyarrhythmias were identified by electrophysiologist review. Risk of ventricular arrhythmias associated with air pollution was estimated with logistic regression, adjusting for season, temperature, relative humidity, day of the week, patient, and a recent prior arrhythmia. We found increased risks of ventricular arrhythmias associated with 2-day mean exposure for all air pollutants considered, although these associations were not statistically significant. We found statistically significant associations between air pollution and ventricular arrhythmias for episodes within 3 days of a previous arrhythmia. The associations of ventricular tachyarrhythmias with fine particle mass, carbon monoxide, nitrogen dioxide, and black carbon suggest a link with motor vehicle pollutants. The associations with sulfate suggest a link with stationary fossil fuel combustion sources
NGTS-4b: A sub-Neptune transiting in the desert
We report the discovery of NGTS-4b, a sub-Neptune-sized planet transiting a 13th magnitude K-dwarf in a 1.34 d orbit. NGTS-4b has a mass M = 20.6 ± 3.0 M⊕ and radius R = 3.18 ± 0.26 R⊕, which places it well within the so-called ‘Neptunian Desert’. The mean density of the planet (3.45 ± 0.95 g cm−3) is consistent with a composition of 100 per cent H2O or a rocky core with a volatile envelope. NGTS-4b is likely to suffer significant mass loss due to relatively strong EUV/X-ray irradiation. Its survival in the Neptunian desert may be due to an unusually high-core mass, or it may have avoided the most intense X-ray irradiation by migrating after the initial activity of its host star had subsided. With a transit depth of 0.13 ± 0.02 per cent, NGTS-4b represents the shallowest transiting system ever discovered from the ground, and is the smallest planet discovered in a wide-field ground-based photometric survey
Characterization of pores in polished low temperature co-fired glass-ceramic composites for optimization of their micromachining
Pores are intrinsic defects of ceramic composites and influence their functional properties significantly. Their characterization is therefore a pivotal task in material and process optimization. It is demonstrated that polished section analysis allows for obtaining precise information on pore size, shape, area fraction, and homogeneous distribution. It is proven that laser scanning microscopy provides accurate height maps and is thus an appropriate technique for assessing surface features. Such data is used to compare areas with good and poor polishing results, and various surface parameters are evaluated in terms of their informative value and data processing effort. The material under investigation is a low temperature co-fired ceramic composite. Through statistical analysis of the data, the inclination angle was identified as an appropriate parameter to describe the polishing result. By using masked data, direct conclusions can be drawn about the leveling of load-bearing surface areas, which are crucial in photolithographic processing steps and bonding technology. A broad discussion of different defects based on the results contributes to a critical analysis of the potentials and obstacles of micromachining of low temperature cofired ceramic substrates.15 página
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