Origin of line tension for a Lennard-Jones nanodroplet

The existence and origin of line tension has remained controversial in literature. To address this issue we compute the shape of Lennard-Jones nanodrops using molecular dynamics and compare them to density functional theory in the approximation of the sharp kink interface. We show that the deviation from Young's law is very small and would correspond to a typical line tension length scale (defined as line tension divided by surface tension) similar to the molecular size and decreasing with Young's angle. We propose an alternative interpretation based on the geometry of the interface at the molecular scale

Formation of surface nanobubbles and universality of their contact angles: A molecular dynamics approach

We study surface nanobubbles using molecular dynamics simulation of ternary (gas, liquid, solid) systems of Lennard-Jones fluids. They form for sufficiently low gas solubility in the liquid, i.e., for large relative gas concentration. For strong enough gas-solid attraction, the surface nanobubble is sitting on a gas layer, which forms in between the liquid and the solid. This gas layer is the reason for the universality of the contact angle, which we calculate from the microscopic parameters. Under the present equilibrium conditions the nanobubbles dissolve within less of a microsecond, consistent with the view that the experimentally found nanobubbles are stabilized by a nonequilibrium mechanism.Comment: 5p,4

Photoemission investigation of the electronic structure of Fe-Pd and Fe-Pt alloys

A photoemission investigation of Fe-Pd and Fe-Pt transition-metal alloys, using ∼50–150-eV synchrotron radiation, is presented. We consider in particular the spectral distribution of Fe states when approaching the dilute limit. By means of the Cooper minimum in the 4d and 5d photoionization cross section, we identify structures that have mainly Fe minority- or Fe majority-spin character. The relative position of these peaks is discussed in terms of the covalent interaction between Fe 3d and Pd or Pt d states. Also, the strong resemblance between the distribution of Fe states in the Pd-based and in the Pt-based alloys is demonstrated. We find a consistent behavior of interacting d states towards the dilute limit. It is concluded that the Fe states that are observed in the photoemission spectra of the dilute alloys have mainly majority-spin character and are, because of the covalent interaction with host states, widely distributed over the energy range of the host d band. The Fe minority-spin band, which is centered near the Fermi level, gradually empties with increasing Fe dilution

Vitamin K Antagonists, Non-Vitamin K Antagonist Oral Anticoagulants, and Vascular Calcification in Patients with Atrial Fibrillation

Background  Vitamin K antagonists (VKAs) are associated with coronary artery calcification in low-risk populations, but their effect on calcification of large arteries remains uncertain. The effect of non-vitamin K antagonist oral anticoagulants (NOACs) on vascular calcification is unknown. We investigated the influence of use of VKA and NOAC on calcification of the aorta and aortic valve. Methods  In patients with atrial fibrillation without a history of major adverse cardiac or cerebrovascular events who underwent computed tomographic angiography, the presence of ascending aorta calcification (AsAC), descending aorta calcification (DAC), and aortic valve calcification (AVC) was determined. Confounders for VKA/NOAC treatment were identified and propensity score adjusted logistic regression explored the association between treatment and calcification (Agatston score > 0). AsAC, DAC, and AVC differences were assessed in propensity score-matched groups. Results  Of 236 patients (33% female, age: 58 ± 9 years), 71 (30%) used VKA (median duration: 122 weeks) and 79 (34%) used NOAC (median duration: 16 weeks). Propensity score-adjusted logistic regression revealed that use of VKA was significantly associated with AsAC (odds ratio [OR]: 2.31; 95% confidence interval [CI]: 1.16-4.59; p  = 0.017) and DAC (OR: 2.38; 95% CI: 1.22-4.67; p  = 0.012) and a trend in AVC (OR: 1.92; 95% CI: 0.98-3.80; p  = 0.059) compared with non-anticoagulation. This association was absent in NOAC versus non-anticoagulant (AsAC OR: 0.51; 95% CI: 0.21-1.21; p  = 0.127; DAC OR: 0.80; 95% CI: 0.36-1.76; p  = 0.577; AVC OR: 0.62; 95% CI: 0.27-1.40; p  = 0.248). A total of 178 patients were propensity score matched in three pairwise comparisons. Again, use of VKA was associated with DAC ( p  = 0.043) and a trend toward more AsAC ( p  = 0.059), while use of NOAC was not (AsAC p  = 0.264; DAC p  = 0.154; AVC p  = 0.280). Conclusion  This cross-sectional study shows that use of VKA seems to contribute to vascular calcification. The calcification effect was not observed in NOAC users

Imaging angiogenesis in patients with head and neck squamous cell carcinomas by [68Ga]Ga-DOTA-E-[c(RGDfK)]2 PET/CT

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Effect of nutritional interventions on nutritional status, quality of life and mortality in patients with head and neck cancer receiving (chemo)radiotherapy: a systematic review q

Head and neck cancer Radiotherapy s u m m a r y Background and aims: We performed a systematic review to examine the effect of nutritional interventions on nutritional status, quality of life (QoL) and mortality in patients with head and neck squamous cell cancer (HNSCC) receiving radiotherapy or chemoradiotherapy. Methods: We searched Pubmed, EMBASE, CENTRAL and Cinahl from inception through January 3rd, 2012 to identify randomized controlled trials (RCTs) from a broad range of nutritional interventions in patients with HNSCC during (chemo)radiotherapy. Two reviewers independently assessed study eligibility and risk of bias, and extracted data. Results: Of 1141 titles identified, 12 study reports were finally included, describing 10 different studies with 11 interventions. Four out of 10 studies examined the effects of individualized dietary counseling, and showed significant benefits on nutritional status and QOL compared to no counseling or general nutritional advice by a nurse (p < 0.05). Three studies on oral nutritional supplements (ONS) were inconsistent about the effect on nutritional status compared with no supplementation. One study showed that nasogastric tube feeding had beneficial effects on nutritional status compared to ONS, but not in all patient groups (p < 0.04). One study showed benefits of percutaneous endoscopic gastronomy (PEG) feeding on nutritional status shortly after RT compared with nasogastric feeding (p ¼ 0.001). Two studies showed that prophylactic PEG feeding was not superior over tube feeding if required. Conclusions: This review shows beneficial effects of individualized dietary counseling on nutritional status and QoL, compared to no counseling or standard nutritional advice. Effects of ONS and tube feeding were inconsistent

Advancing catchment hydrology to deal with predictions under change

Throughout its historical development, hydrology as an earth science, but especially as a problem-centred engineering discipline has largely relied (quite successfully) on the assumption of stationarity. This includes assuming time invariance of boundary conditions such as climate, system configurations such as land use, topography and morphology, and dynamics such as flow regimes and flood recurrence at different spatio-temporal aggregation scales. The justification for this assumption was often that when compared with the temporal, spatial, or topical extent of the questions posed to hydrology, such conditions could indeed be considered stationary, and therefore the neglect of certain long-term non-stationarities or feedback effects (even if they were known) would not introduce a large error. However, over time two closely related phenomena emerged that have increasingly reduced the general applicability of the stationarity concept: the first is the rapid and extensive global changes in many parts of the hydrological cycle, changing formerly stationary systems to transient ones. The second is that the questions posed to hydrology have become increasingly more complex, requiring the joint consideration of increasingly more (sub-) systems and their interactions across more and longer timescales, which limits the applicability of stationarity assumptions. Therefore, the applicability of hydrological concepts based on stationarity has diminished at the same rate as the complexity of the hydrological problems we are confronted with and the transient nature of the hydrological systems we are dealing with has increased. The aim of this paper is to present and discuss potentially helpful paradigms and theories that should be considered as we seek to better understand complex hydrological systems under change. For the sake of brevity we focus on catchment hydrology. We begin with a discussion of the general nature of explanation in hydrology and briefly review the history of catchment hydrology. We then propose and discuss several perspectives on catchments: as complex dynamical systems, self-organizing systems, co-evolving systems and open dissipative thermodynamic systems. We discuss the benefits of comparative hydrology and of taking an information-theoretic view of catchments, including the flow of information from data to models to predictions. In summary, we suggest that these perspectives deserve closer attention and that their synergistic combination can advance catchment hydrology to address questions of change

Antiarrhythmic drugs in patients with early persistent atrial fibrillation and heart failure:results of the RACE 3 study

Aims: Maintaining sinus rhythm in patients with persistent atrial fibrillation (AF) is challenging. We explored the efficacy of class I and III antiarrhythmic drugs (AADs) in patients with persistent AF and mild to moderate heart failure (HF). Methods and results: In the RACE 3 trial, patients with early persistent symptomatic AF and short history of mild to moderate HF with preserved or reduced left ventricular ejection fraction (LVEF) were randomized to targeted or conventional therapy. Both groups received AF and HF guideline-driven treatment. Additionally, the targeted-group received mineralocorticoid receptor antagonists, statins, angiotensin-converting enzyme inhibitors and/or receptor blockers, and cardiac rehabilitation. Class I and III AADs could be instituted in case of symptomatic recurrent AF. Eventually, pulmonary vein isolation could be performed. Primary endpoint was sinus rhythm on 7-day Holter after 1-year. Included were 245 patients, age 65 ± 9 years, 193 (79%) men, AF history was 3 (2-6) months, HF history 2 (1-4) months, 72 (29.4%) had HF with reduced LVEF. After baseline electrical cardioversion (ECV), 190 (77.6%) had AF recurrences; 108 (56.8%) received class I/III AADs; 19 (17.6%) flecainide, 36 (33.3%) sotalol, 3 (2.8%) dronedarone, 50 (46.3%) amiodarone. At 1-year 73 of 108 (68.0%) patients were in sinus rhythm, 44 (40.7%) without new AF recurrences. Maintenance of sinus rhythm was significantly better with amiodarone [n = 29/50 (58%)] compared with flecainide [n = 6/19 (32%)] and sotalol/dronedarone [n = 9/39 (23%)], P = 0.0064. Adverse events occurred in 27 (25.0%) patients, were all minor and reversible. Conclusion: In stable HF patients with early persistent AF, AAD treatment was effective in nearly half of patients, with no serious adverse effects reported