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•Isolated molten island are formed at the onset of melt.•The liquid/solid interface remains rough in partial melt regime.•Relaxation is linked to liquid/solid interface ...roughness.•Relaxation is linked to the elastic energy stored in SiGe layers.
30 nm-thick pseudomorphic Si1−xGex layers with Ge concentrations x ranging from 0 to 0.4 were submitted to Ultraviolet Nanosecond Laser Annealing (UV-NLA). The impact of UV-NLA on the various regimes and on the layer crystallinity was assessed for each Ge concentration. This study highlighted the existence of four annealing regimes, with notably a surface melt regime with isolated molten islands on the surface. The strain in the layer depended on the liquid/solid interface roughness and on the stored elastic energy in the layers. In the case of smooth liquid/solid interfaces, a limit for perfect recrystallization was estimated near 750 mJ/m2.
Enhancing optical nonlinearities so that they become appreciable on the single photon level and lead to nonclassical light fields has been a central objective in quantum optics for many years. After ...this has been achieved in individual micro-cavities representing an effectively zero-dimensional volume, this line of research has shifted its focus towards engineering devices where such strong optical nonlinearities simultaneously occur in extended volumes of multiple nodes of a network. Recent technological progress in several experimental platforms now opens the possibility to employ the systems of strongly interacting photons, these give rise to as quantum simulators. Here we review the recent development and current status of this research direction for theory and experiment. Addressing both, optical photons interacting with atoms and microwave photons in networks of superconducting circuits, we focus on analogue quantum simulations in scenarios where effective photon-photon interactions exceed dissipative processes in the considered platforms.
•550 °C epitaxy of tensile SiP. with disilane and phosphine.•Various strategies evaluated to obtain low resistivities and high Psubst.•High phosphine to disilane mass-flow, low H2 carrier flow and ...high pressure.•Smooth and uniform t-Si:P layers with a substitutional P concentration of 6.3%.•Electrical resistivity much lower than with a chlorinated chemistry.
Our long-term aim was to explore the Low Temperature Cyclic Deposition/Etch (CDE) of tensile-Si:P, in order to engineer the Sources and Drains of n-type Field Effect Transistors. We wanted to have high amounts of tensile strain and low resistivities in tensile Si:P layers grown at 550 °C, with (i) mainstream Si2H6 + PH3 gases for the non-selective deposition of t-Si:P and (ii) HCl + GeH4 for the selective etches of amorphous-Si:P versus monocrystalline Si:P (to have selectivity on patterned wafers). In the current study, we have focused on the deposition in such processes, having shown beforehand that, indeed, t-Si:P could be etched at 550 °C with HCl + GeH4 if the process conditions were right (Hartmann J.M. and Veillerot M., 2020 Semicond. Sci. Technol. 35 015015). Thanks to (i) high F(PH3)/(2*F(Si2H6)) Mass-Flow Ratios (MFR), (ii) a reduction of the H2 carrier flow, from the reference value of a few tens of standard liters per minute down to 1/5th of it and (iii) a chamber pressure increase, from 20 Torr up to 90 Torr, we succeeded in dramatically increasing the “substitutional” P concentration. and reaching values as high as 7.9%. 40 Torr was the best pressure in order to simultaneously have (i) a high “substitutional” P concentration (6.3%), (ii) a reasonable t-Si:P growth rate (5.5 nm min−1) and (iii) a low electrical resistivity (0.41 mOhm·cm), without being hampered by a layer uniformity that would be too degraded to be of use in actual devices. Those t-Si:P layers, grown with a MFR of 0.46, were of superior crystalline quality (in X-Ray Diffraction) and smooth (from haze measurements).
The absorption by oxygen in the region of the O2 A band near 760 nm has been measured in the laboratory under various conditions of pressure (20–200 atm) and temperature (200–300 K) for both pure O2 ...and O2‐N2 mixtures. In order to calculate the contribution of the “allowed” A band transitions, Lorentzian profiles and a model accounting for line‐mixing (LM) effects using the energy corrected sudden (ECS) approximation have been used. The differences between computed spectra and measured values enable extraction of the collision‐induced absorption (CIA) contribution. It is shown that neglecting line mixing overestimates absorption in the wings and underestimates absorption at the P and R branch peaks, whereas the CIA extracted by the line‐mixing approach shows the “smooth” profile expected. Applying this approach to our spectra enables determination of the CIA and allowed contributions for both O2‐O2 and O2‐N2 collisions versus temperature and pressure. The resulting model and data are then used to build a database and some software suitable for the calculation of oxygen (in air) atmospheric absorption and for easy inclusion in radiative transfer codes (available upon request). These tools are then applied to a theoretical study of the influences of both line‐mixing and collision‐induced processes on atmospheric photon path escape factors and on cloud‐top altitude retrievals. It is shown that LM and CIA make significant contributions and explain a large part of the discrepancies between measured and calculated atmospheric absorption observed recently.
Genome-wide association studies implicate dysregulation of immune mechanisms in the pathogenesis of multiple sclerosis (MS). Particularly, polymorphisms in genes involved in T helper (TH) cell ...differentiation are associated with risk of developing MS. However, the underlying mechanism by which these risk alleles influence MS susceptibility has remained elusive. Initiation of neuroinflammation in animal models of MS has been shown to be dependent on TH cell-derived granulocyte-macrophage colony-stimulating factor (GM-CSF). We here report association of GM-CSF expression by human TH cells with MS disease severity. GM-CSF is strongly induced by interleukin 2 (IL-2). We show that an MS-associated polymorphism in the IL-2 receptor alpha (IL2RA) gene specifically increases the frequency of GM-CSF-producing TH cells. The IL2RA polymorphism regulates IL-2 responsiveness of naive TH cells and their propensity to develop into GM-CSF-producing memory TH cells. These findings mechanistically link an immunologically relevant genetic risk factor with a functional feature of TH cells in MS.
Terrestrial carbon export via inland aquatic systems is a key process in the global carbon cycle. It includes loss of carbon to the atmosphere via outgassing from rivers, lakes, or reservoirs and ...carbon fixation in the water column as well as in sediments. This review focuses on headwater streams that are important because their stream biogeochemistry directly reflects carbon input from soils and groundwaters. Major drivers of carbon dioxide partial pressures (pCO2) in streams and mechanisms of terrestrial dissolved inorganic, organic and particulate organic carbon (DIC, DOC, and POC) influxes are summarized in this work. Our analysis indicates that the global river average pCO2 of 3100 ppmV is more often exceeded by contributions from small streams when compared to rivers with larger catchments (> 500 km2). Because of their large proportion in global river networks (> 96% of the total number of streams), headwaters contribute large—but still poorly quantified—amounts of CO2 to the atmosphere. Conservative estimates imply that globally 36% (i.e., 0.93 Pg C yr−1) of total CO2 outgassing from rivers and streams originate from headwaters. We also discuss challenges in determination of CO2 sources, concentrations, and fluxes. To overcome uncertainties of CO2 sources and its outgassing from headwater streams on the global scale, new investigations are needed that should include groundwater data. Such studies would also benefit from applications of integral CO2 outgassing isotope approaches and multiscale geophysical imaging techniques.
Key Points
In terms of carbon fluxes, high cumulative contributions of headwater streams are currently underrepresented in the global carbon cycle
Representative quantification of carbon dioxide outgassing from headwater streams on a global scale is an important future challenge
A global analysis of small catchment chemistry revealed substantial influences of trace carbonate weathering on stream carbon budgets
This systematic review and meta‐analysis of effectiveness trials comparing multicomponent behavioural weight management programmes with controls in overweight and obese adults set out to determine ...the effectiveness of these interventions implemented in routine practice. To be included, interventions must have been multicomponent, delivered by the therapists who would deliver the intervention in routine practice and in that same context, and must be widely available or feasible to implement with little additional infrastructure or staffing. Searches of electronic databases were conducted, and augmented by screening reference lists and contacting experts (November 2012). Data were extracted by two reviewers, with mean difference between intervention and control for 12‐month change in weight, blood pressure, lipids and glucose calculated using baseline observation carried forward. Data were also extracted on adverse events, quality of life and mood measures. Although there were many published efficacy trials, only eight effectiveness trials met the inclusion criteria. Pooled results from five study arms providing access to commercial weight management programmes detected significant weight loss at 12 months (mean difference −2.22 kg, 95% confidence interval CI −2.90 to −1.54). Results from two arms of a study testing a commercial programme providing meal replacements also detected significant weight loss (mean difference −6.83 kg, 95% CI −8.39 to −5.26). In contrast, pooled results from five interventions delivered by primary care teams showed no evidence of an effect on weight (mean difference −0.45 kg, 95% CI −1.34 to 0.43). One study testing an interactive web‐based intervention detected a significant effect in favour of the intervention at 12 months, but the study was judged to be at high risk of bias and the effect did not persist at 18 months. Few studies reported other outcomes, limiting comparisons between interventions. Few trials have examined the effectiveness of behavioural weight loss programmes delivered in everyday contexts. These trials suggest that commercial interventions delivered in the community are effective for achieving weight loss. There is no evidence that interventions delivered within primary care settings by generalist primary care teams trained in weight management achieve meaningful weight loss.
In November 2011, the Third European Consensus Conference on Diagnosis and Treatment of Germ-Cell Cancer (GCC) was held in Berlin, Germany. This third conference followed similar meetings in 2003 ...(Essen, Germany) and 2006 (Amsterdam, The Netherlands) Schmoll H-J, Souchon R, Krege S et al. European consensus on diagnosis and treatment of germ-cell cancer: a report of the European Germ-Cell Cancer Consensus Group (EGCCCG). Ann Oncol 2004; 15: 1377–1399; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part I. Eur Urol 2008; 53: 478–496; Krege S, Beyer J, Souchon R et al. European consensus conference on diagnosis and treatment of germ-cell cancer: a report of the second meeting of the European Germ-Cell Cancer Consensus group (EGCCCG): part II. Eur Urol 2008; 53: 497–513. A panel of 56 of 60 invited GCC experts from all across Europe discussed all aspects on diagnosis and treatment of GCC, with a particular focus on acute and late toxic effects as well as on survivorship issues.
The panel consisted of oncologists, urologic surgeons, radiooncologists, pathologists and basic scientists, who are all actively involved in care of GCC patients. Panelists were chosen based on the publication activity in recent years. Before the meeting, panelists were asked to review the literature published since 2006 in 20 major areas concerning all aspects of diagnosis, treatment and follow-up of GCC patients, and to prepare an updated version of the previous recommendations to be discussed at the conference. In addition, ∼50 E-vote questions were drafted and presented at the conference to address the most controversial areas for a poll of expert opinions. Here, we present the main recommendations and controversies of this meeting. The votes of the panelists are added as online supplements.
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