Semianalytical calculation of the zonal-flow oscillation frequency in stellarators

Due to their capability to reduce turbulent transport in magnetized plasmas, understanding the dynamics of zonal flows is an important problem in the fusion programme. Since the pioneering work by Rosenbluth and Hinton in axisymmetric tokamaks, it is known that studying the linear and collisionless relaxation of zonal flow perturbations gives valuable information and physical insight. Recently, the problem has been investigated in stellarators and it has been found that in these devices the relaxation process exhibits a characteristic feature: a damped oscillation. The frequency of this oscillation might be a relevant parameter in the regulation of turbulent transport, and therefore its efficient and accurate calculation is important. Although an analytical expression can be derived for the frequency, its numerical evaluation is not simple and has not been exploited systematically so far. Here, a numerical method for its evaluation is considered, and the results are compared with those obtained by calculating the frequency from gyrokinetic simulations. This "semianalytical" approach for the determination of the zonal-flow frequency reveals accurate and faster than the one based on gyrokinetic simulations.Comment: 30 pages, 14 figure

A simplified implementation of the stationary liquid mass balance method for on-line OUR monitoring in animal cell cultures

This is the peer reviewed version of the following article: [Fontova, A. , Lecina, M. , López‐Repullo, J. , Martínez‐Monge, I. , Comas, P. , Bragós, R. and Cairó, J. J. (2018), A simplified implementation of the stationary liquid mass balance method for on‐line OUR monitoring in animal cell cultures. J. Chem. Technol. Biotechnol. doi:10.1002/jctb.5551], which has been published in final form at [doi:10.1002/jctb.5551]. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.BACKGROUND: Compared with other methods, the stationary liquid mass balance method for oxygen uptake rate (OUR) determination offers advantages in terms of estimation accuracy and reduction of stress. However, the need for sophisticated instrumentation, like mass flow controllers and gas analysers, has historically limited wider implementation of such a method. In this paper, a new simplified method based on inexpensive valves for the continuous estimation of OUR in animal cell cultures is evaluated. The determination of OUR values is based on accurate operation of the dissolved oxygen (DO) control loop and monitoring of its internal variables. RESULTS: The method developed was tested empirically in 2¿L bioreactor HEK293 batch cultures. OUR profiles obtained by a dynamic method, global mass balance method and the developed simplified method were monitored and compared. The results show how OUR profile obtained with the proposed method better follows the off-line cell density determination. The OUR estimation frequency was also increased, improving the method capabilities and applications. The theoretical rationale of the method was extended to the sensitivity analysis which was analytically and numerically approached. CONCLUSIONS: The results showed the proposed method to be not only cheap, but also a reliable alternative to monitor the metabolic activity in bioreactors in many biotechnological processes, being a useful tool for high cell density culture strategies implementation based on OUR monitoring.Peer ReviewedPostprint (published version

Sinking of light intruders in a shaken granular bed

We present an experimental study of the displacement of a light intruder immersed in a vibrated granular bed. Using high speed video we resolve the motion, during one cycle of oscillation, of a cylindrical object inside a Plexiglas box partially filled with grains. We report experimental evidence that, in the absence of convection, at least two forces are behind the intruder’s motion: an air drag force—due to the airflow through the granular bed—and a buoyancy force produced by an air-mediated granular fluid

Treatment with zygomatic implants in patients with advanced atrophy of maxilla

Introducción. El objetivo del presente estudio era mostrar los resultados del tratamiento con implantes cigomáticos utilizados en pacientes con atrofia maxilar severa. Metodos. 18 pacientes fueron tratados con 36 implantes cigomáticos Galimplant ® sumergidos con conexión interna para su rehabilitación prostodóncica. Las técnicas quirúrgicas de inserción de cigomáticos fueron extrasinusal y la técnica de la ranura sinusal. Los implantes fueron cargados después de un periodo de cicatrización de 6 meses. Resultados. Los hallazgos clínicos indican una supervivencia de los implantes del 100%. 14 implantes (38,9%) se in- sertaron por via extrasinusal y 22 implantes (61,6%) por la técnica de la ranura sinusal. Un total de 18 prótesis híbridas atornilladas fueron realizadas. Complicaciones postoperatorias fueron observadas en 4 pacientes (22,2%). El periodo medio de seguimiento clínico ha sido de 12 meses. Conclusiones. Este estudio indica que los implantes cigomáticos pueden ser utilizados con éxito en el tratamiento de los pacientes con atrofia maxilar severaThe aim of this study was to report the outcome of treatment with zygomatic implants used in patients with severe atrophy of maxilla. Methods. 18 patients were treated with 36 Galimplant ® zygomatic implants with internal connection for prosthodontic rehabilitation. Zygomatic surgical techniques were two approach for insertion of implants, extrasinusal and sinus slot technique. Implants were loaded after a healing free-loading period of six months. Results. Clinical results indicate a survival rate of implants of 100%. Fourteen implants (38.9%) were inser- ted by extrasinusal approach while twenty two implants were inserted by sinus slot approach (61.1%). A total of 18 hybrid screw prostheses were realized. Postoperative complications were observed in four patients (22.2%). The mean follow-up period were 12 months. Conclusions. This study indicate that zygomatic implants can be used with success in treatment of patients with severe atrophic maxilla

Towards a relevant set of state variables to describe static granular packings

We analyze, experimentally and numerically, the steady states, obtained by tapping, of a two-dimensional granular layer. Contrary to the usual assumption, we show that the reversible (steady state branch) of the density-acceleration curve is nonmonotonous. Accordingly, steady states with the same mean volume can be reached by tapping the system with very different intensities. Simulations of dissipative frictional disks show that equal volume steady states have different values of the force moment tensor. Additionally, we find that steady states of equal stress can be obtained by changing the duration of the taps; however, these states present distinct mean volumes. These results confirm previous speculations that the volume and the force moment tensor are both needed to describe univocally equilibrium states in static granular assemblies

The Role of the Interactions at the Tungsten Disulphide Surface in the Stability and Enhanced Thermal Properties of Nanofluids with Application in Solar Thermal Energy

Transition metal dichalcogenides (TMCs) exhibit unique properties that make them of interest for catalysis, sensing or energy storage applications. However, few studies have been performed into nanofluids based on TMCs for heat transfer applications. In this study, nanofluids based on 2D-WS2 are prepared by liquid phase exfoliation to analyze their potential usage in concentrating solar power plants. Periodic-Density Functional Theory (DFT) calculations were performed to rationalize the success of the exfoliation process. The hydrogen bond interaction between the hydroxyl group from PEG, which acts as a surfactant, and the S atoms of the WS2 surface stabilizes the nanosheets in the fluid. Electron localization function (ELF) analysis is indicative of the stability of the S-H interaction from WS2 with the molecules of surfactant due to the tendency to interact through weak intermolecular forces of van der Waals solids. Moreover, improvements in thermal properties were also found. Isobaric specific heat increased by up to 10% and thermal conductivity improved by up to 37.3%. The high stability of the nanofluids and the thermal improvements were associated with the high surface area of WS2 nanosheets. These results suggest that these nanofluids could be a promising heat transfer fluid in concentrating solar power plants

Generalized Central Limit Theorem and Renormalization Group

We introduce a simple instance of the renormalization group transformation in the Banach space of probability densities. By changing the scaling of the renormalized variables we obtain, as fixed points of the transformation, the L\'evy strictly stable laws. We also investigate the behavior of the transformation around these fixed points and the domain of attraction for different values of the scaling parameter. The physical interest of a renormalization group approach to the generalized central limit theorem is discussed.Comment: 16 pages, to appear in J. Stat. Phy

Characterization of CD34+ hematopoietic cells in systemic mastocytosis: Potential role in disease dissemination

[Background]: Recent studies show that most systemic mastocytosis (SM) patients, including indolent SM (ISM) with (ISMs+) and without skin lesions (ISMs−), carry the KIT D816V mutation in PB leukocytes. We investigated the potential association between the degree of involvement of BM hematopoiesis by the KIT D816V mutation and the distribution of different maturation-associated compartments of bone marrow (BM) and peripheral blood (PB) CD34+ hematopoietic precursors (HPC) in ISM and identified the specific PB cell compartments that carry this mutation. [Methods]: The distribution of different maturation-associated subsets of BM and PB CD34+ HPC from 64 newly diagnosed (KIT-mutated) ISM patients and 14 healthy controls was analyzed by flow cytometry. In 18 patients, distinct FACS-purified PB cell compartments were also investigated for the KIT mutation. [Results]: ISM patients showed higher percentages of both BM and PB MC-committed CD34+ HPC vs controls, particularly among ISM cases with MC-restricted KIT mutation (ISMMC); this was associated with progressive blockade of maturation of CD34+ HPC to the neutrophil lineage from ISMMC to multilineage KIT-mutated cases (ISMML). Regarding the frequency of KIT-mutated cases and cell populations in PB, variable patterns were observed, the percentage of KIT-mutated PB CD34+ HPC, eosinophils, neutrophils, monocytes and T cells increasing from ISMs−MC and ISMs+MC to ISMML patients. [Conclusion]: The presence of the KIT D816V mutation in PB of ISM patients is associated with (early) involvement of circulating CD34+ HPC and multiple myeloid cell subpopulations, KIT-mutated PB CD34+ HPC potentially contributing to early dissemination of the disease.This work was supported by Fondo de Investigaciones Sanitarias—FIS—of the Instituto de Salud Carlos III, Ministerio de Economía y Competitividad, Madrid, Spain (grant numbers PI11/02399 and PI16/00642, FEDER); Consejería de Educación (Regional Government of Castilla y León, Spain; grant number SA013U16); Biomedical Research Networking Centre Consortium–CIBER-CIBERONC (CB16/12/00400) of the Instituto de Salud Carlos III, Madrid, Spain; and Fundacion Ramon Areces, Madrid, Spain (grant CIVP16A1806). AM was supported by a RTICC (Red Tematica de Investigacion Cooperativa en Cancer) grant (RD12/0036/0048, FIS, FEDER)

Detection of the KIT D816V mutation in peripheral blood of systemic mastocytosis: diagnostic implications

Recent studies have found the KIT D816V mutation in peripheral blood of virtually all adult systemic mastocytosis patients once highly sensitive PCR techniques were used; thus, detection of the KIT D816V mutation in peripheral blood has been proposed to be included in the diagnostic work-up of systemic mastocytosis algorithms. However, the precise frequency of the mutation, the biological significance of peripheral blood-mutated cells and their potential association with involvement of bone marrow hematopoietic cells other than mast cells still remain to be investigated. Here, we determined the frequency of peripheral blood involvement by the KIT D816V mutation, as assessed by two highly sensitive PCR methods, and investigated its relationship with multilineage involvement of bone marrow hematopoiesis. Overall, our results confirmed the presence of the KIT D816V mutation in peripheral blood of most systemic mastocytosis cases (161/190; 85%)-with an increasing frequency from indolent systemic mastocytosis without skin lesions (29/44; 66%) to indolent systemic mastocytosis with skin involvement (124/135; 92%), and more aggressive disease subtypes (11/11; 100%)-as assessed by the allele-specific oligonucleotide-qPCR method, which was more sensitive (P<.0001) than the peptide nucleic acid-mediated PCR approach (84/190; 44%). Although the presence of the KIT mutation in peripheral blood, as assessed by the allele-specific oligonucleotide-qPCR technique, did not accurately predict for multilineage bone marrow involvement of hematopoiesis, the allele-specific oligonucleotide-qPCR allele burden and the peptide nucleic acid-mediated-PCR approach did. These results suggest that both methods provide clinically useful and complementary information through the identification and/or quantification of the KIT D816V mutation in peripheral blood of patients suspected of systemic mastocytosis.This work was supported in part by grants from the Fondo de Investigaciones Sanitarias (FIS; grant number PI11/02399, FEDER) and Red Temática de Investigación Cooperativa en Cancer (RTICC; grant number RD12/0036/0048, FEDER) of the Instituto deSalud Carlos III (Ministry of Economy and Competitivity, Madrid, Spain), from Fundacion Ramon Areces (Madrid, Spain; grant number CIVP16A1806) and from Ayudas a Proyectos de Investigación en Salud de la Fundación Mutua Madrileña 2014 and Asociación Española de Enfermos de Mastocitosis (AEDM 2014). The National DNA Bank is supported by grants from the Instituto de Salud Carlos III of the Ministerio de Economia y Competitividad of Spain (grand numbers PT13/0001/0037 and PT13/0010/ 0067, FEDER). AM was supported by RTICC.Peer Reviewe

Frequency and prognostic impact of blood-circulating tumor mast cells in mastocytosis

Circulating tumor mast cells (CTMCs) have been identified in the blood of a small number of patients with advanced systemic mastocytosis (SM). However, data are limited about their frequency and prognostic impact in patients with MC activation syndrome (MCAS), cutaneous mastocytosis (CM) and nonadvanced SM. We investigated the presence of CTMCs and MC-committed CD34+ precursors in the blood of 214 patients with MCAS, CM, or SM using highly sensitive next-generation flow cytometry. CTMCs were detected at progressively lower counts in almost all patients with advanced SM (96%) and smoldering SM (SSM; 100%), nearly half of the patients (45%) with indolent SM (ISM), and a few patients (7%) with bone marrow (BM) mastocytosis but were systematically absent in patients with CM and MCAS (P < .0001). In contrast to CTMC counts, the number of MC-committed CD34+ precursors progressively decreased from MCAS, CM, and BM mastocytosis to ISM, SSM, and advanced SM (P < .0001). Clinically, the presence (and number) of CTMCs in blood of patients with SM in general and nonadvanced SM (ISM and BM mastocytosis) in particular was associated with more adverse features of the disease, poorer-risk prognostic subgroups as defined by the International Prognostic Scoring System for advanced SM (P < .0001) and the Global Prognostic Score for mastocytosis (P < .0001), and a significantly shortened progression-free survival (P < .0001) and overall survival (P = .01). On the basis of our results, CTMCs emerge as a novel candidate biomarker of disseminated disease in SM that is strongly associated with advanced SM and poorer prognosis in patients with ISM