Equilibrium roughening transition in a 1D modified sine-Gordon model

We present a modified version of the one-dimensional sine-Gordon that exhibits a thermodynamic, roughening phase transition, in analogy with the 2D usual sine-Gordon model. The model is suited to study the crystalline growth over an impenetrable substrate and to describe the wetting transition of a liquid that forms layers. We use the transfer integral technique to write down the pseudo-Schr\"odinger equation for the model, which allows to obtain some analytical insight, and to compute numerically the free energy from the exact transfer operator. We compare the results with Monte Carlo simulations of the model, finding a perfect agreement between both procedures. We thus establish that the model shows a phase transition between a low temperature flat phase and a high temperature rough one. The fact that the model is one dimensional and that it has a true phase transition makes it an ideal framework for further studies of roughening phase transitions.Comment: 11 pages, 13 figures. Accepted for publication in Physical Review

Super-roughening as a disorder-dominated flat phase

We study the phenomenon of super-roughening found on surfaces growing on disordered substrates. We consider a one-dimensional version of the problem for which the pure, ordered model exhibits a roughening phase transition. Extensive numerical simulations combined with analytical approximations indicate that super-roughening is a regime of asymptotically flat surfaces with non-trivial, rough short-scale features arising from the competition between surface tension and disorder. Based on this evidence and on previous simulations of the two-dimensional Random sine-Gordon model [Sanchez et al., Phys. Rev. E 62, 3219 (2000)], we argue that this scenario is general and explains equally well the hitherto poorly understood two-dimensional case.Comment: 7 pages, 4 figures. Accepted for publication in Europhysics Letter

Mechanisms Behind the Generalized Synchronization Conditions

A universal mechanism underlying generalized synchronization conditions in unidirectionally coupled stochastic oscillators is considered. The consideration is carried out in the framework of a modified system with additional dissipation. The approach developed is illustrated with model examples. The conclusion is reached that two types of the behavior of nonlinear dynamic systems known as generalized synchronization and noise-induced synchronization, which are viewed as different phenomena, actually represent a unique type of the synchronous behavior of stochastic oscillators and are caused by the same mechanism.Comment: 8 pages, 5 figure

Nucleofection induces non-specific changes in the metabolic activity of transfected cells

Transfection has become an everyday technique widely used for functional studies in living cells. The choice of the particular transfection method is usually determined by its efficiency and toxicity, and possible functional consequences specific to the method used are normally overlooked. We describe here that nucleofection, a method increasingly used because of its convenience and high efficiency, increases the metabolic rate of some cancer cells, which can be misleading when used as a measure of proliferation. Moreover, nucleofection can alter the subcellular expression pattern of the transfected protein. These undesired effects are independent of the transfected nucleic acid, but depend on the particular cell line used. Therefore, the interpretation of functional data using this technology requires further controls and caution

Dendritic cell deficiencies persist seven months after SARS-CoV-2 infection

Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV)-2 infection induces an exacerbated inflammation driven by innate immunity components. Dendritic cells (DCs) play a key role in the defense against viral infections, for instance plasmacytoid DCs (pDCs), have the capacity to produce vast amounts of interferon-alpha (IFN-α). In COVID-19 there is a deficit in DC numbers and IFN-α production, which has been associated with disease severity. In this work, we described that in addition to the DC deficiency, several DC activation and homing markers were altered in acute COVID-19 patients, which were associated with multiple inflammatory markers. Remarkably, previously hospitalized and nonhospitalized patients remained with decreased numbers of CD1c+ myeloid DCs and pDCs seven months after SARS-CoV-2 infection. Moreover, the expression of DC markers such as CD86 and CD4 were only restored in previously nonhospitalized patients, while no restoration of integrin β7 and indoleamine 2,3-dyoxigenase (IDO) levels were observed. These findings contribute to a better understanding of the immunological sequelae of COVID-19

SARS-CoV-2 viral load in nasopharyngeal swabs is not an independent predictor of unfavorable outcome

The aim was to assess the ability of nasopharyngeal SARS-CoV-2 viral load at first patient’s hospital evaluation to predict unfavorable outcomes. We conducted a prospective cohort study including 321 adult patients with confirmed COVID-19 through RT-PCR in nasopharyngeal swabs. Quantitative Synthetic SARS-CoV-2 RNA cycle threshold values were used to calculate the viral load in log10 copies/mL. Disease severity at the end of follow up was categorized into mild, moderate, and severe. Primary endpoint was a composite of intensive care unit (ICU) admission and/or death (n = 85, 26.4%). Univariable and multivariable logistic regression analyses were performed. Nasopharyngeal SARS-CoV-2 viral load over the second quartile (≥ 7.35 log10 copies/mL, p = 0.003) and second tertile (≥ 8.27 log10 copies/mL, p = 0.01) were associated to unfavorable outcome in the unadjusted logistic regression analysis. However, in the final multivariable analysis, viral load was not independently associated with an unfavorable outcome. Five predictors were independently associated with increased odds of ICU admission and/or death: age ≥ 70 years, SpO2, neutrophils > 7.5 × 103/µL, lactate dehydrogenase ≥ 300 U/L, and C-reactive protein ≥ 100 mg/L. In summary, nasopharyngeal SARS-CoV-2 viral load on admission is generally high in patients with COVID-19, regardless of illness severity, but it cannot be used as an independent predictor of unfavorable clinical outcome

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Iron-modified carbon paste electrodes and their application as sensors in As(V) detection

La detección electroquímica de arsénico(V) fue evaluada en un electrodo de pasta de carbón modificado con partículas de hidro(óxidos) de hierro en medio electrolítico de NaNO3. El polvo de grafito modificado se preparó fácilmente utilizando el método “slurry”. El material resultante fue caracterizado mediante la determinación de su distribución de carga superficial y punto de carga cero, distribución de pKa’s de los grupos funcionales superficiales, área superficial y distribución de tamaño del poro mediante la ecuación de Brunauer- Emmett-Teller (BET) y la identificación de las formas cristalinas de los compuestos de hidro(óxidos) de hierro por difracción de rayos X. Adicionalmente, se encontró que el material modificado exhibió una buena capacidad de remoción de As(V), incluso en el medio electrolítico. Para la detección de As(V), se utilizó la técnica de voltamperometría de pulso diferencial, para la cual se aplicó un potencial de reducción/acumulación de -1.10 V(vs. Ag/AgCl/KCl (sat.) por 180 segundos a pH 2.5. La caracterización fisicoquímica de los materiales modificados y el análisis electroquímico, permitió proponer un mecanismo de reducción de As(V) sobre la superficie del electrodo. El límite de detección (LOD) de As(V) alcanzado fue de 19.40 μg/L, por lo cual este electrodo podría ser potencialmente aplicado como sensor en la detección de este contaminante en muestras de aguaThe electrochemical detection of arsenic (V) [As(V)] was evaluated on a carbon paste electrode modified with iron hydro(oxide) particles in the presence of NaNO3 salt used as electrolytic media in the experiments. The modified graphite powder was easily prepared using the slurry method. The resulting material was examined by surface charge and pKa’s distribution, point of zero charge, Brunauer-Emmett-Teller (BET) surface area and pore size distribution, potentiometric titration and X-ray diffraction. Adsorption experiments with the modified materials exhibited good As(V) removal capacity even in the presence of electrolytic media. For the As(V) detection, differential pulse voltammetry technique was used by the application of reduction potential of -1.10 V for 180 s at pH 2.5. The detailed physicochemical characterization of modified materials and electrochemical analysis allowed to propose a reduction mechanism of As(V) on the electrode surface. Detection limit of 10 μg/L can be achieved for As(V), therefore this electrode could potentially be applied as a sensor for the detection of this pollutant in water sample

Experience on Series Production of the Superconducting Magnet Package for the Linear Accelerator of the European XFEL

Abstract—The procurement of 103 superconducting magnetpackages is part of the Spanish in-kind contribution to theEuropean X-FEL. Each package consists of a main superferricquadrupole and two steerers, vertical and horizontal, fed byconduction-cooled current leads and enclosed in a stainless steelvessel. The operation temperature is 2 K, as they are embeddedin a superfluid helium bath. The magnetic and mechanicaldesigns are published elsewhere. The magnets are beingproduced in the Spanish company ANTEC, while the vessels arefabricated by another Spanish company, Trinos Vacuum-Projects, which is also responsible for the integration, under thesupervision of CIEMAT. The helium vessel manufacturer needsto accomplish the requirements given by the European PressureEquipment Directive, namely PED 97/23/EC. This paperdescribes the series fabrication techniques, the production followup,the quality assurance and the magnet testing at themanufacturer site. Cold tests are realized at DESY premises. Themain problems found during the fabrication of the first half ofthe series are also reported: a) the reproducibility of thequadrupole coil dimensions; b) the accuracy of the beam positionmonitor housing after final welding of the vessel; and c) theminimization of the magnetization effects on the transfer functionof the magnets

Development and testing of a double length pets for the CLIC experimental area

CLIC (compact linear collider) is a future e þ e collider based on normal-conducting technology, currently under study at CERN. Its design is based on a novel two-beam acceleration scheme. The main beam gets RF power extracted from a drive beam through power extraction and transfer structures (PETS). The technical feasibility of CLIC is currently being proved by its Third Test Facility (CTF3) which includes the CLIC experimental area (CLEX). Two Double Length CLIC PETS will be installed in CLEX to validate their performance with beam. This paper is focused on the engineering design, fabrication and validation of this PETS fi rst prototype. The design consists of eight identical bars, separated by radial slots in which damping material is located to absorb transverse wake fi elds, and two compact couplers placed at both ends of the bars to extract the generated power. The PETS bars are housed inside a vacuum tank designed to make the PETS as compact as possible. Several joint techniques such as vacuum brazing, electron beam and arc welding were used to complete the assembly. Finally, several tests such as dimensional control and leak testing were carried out to validate design and fabrication methods. In addition, RF measurements at low power were made to study frequency tunin