[Open surgical management of recurrent pigmented villonodular synovitis: case report and literature review]. / Manejo quirúrgico abierto de la sinovitis villonodular pigmentada recurrente: reporte de caso y revisión de literatura.

INTRODUCTION: pigmented villonodular synovitis (PVNS) is a benign condition that affects the knee, leading to abnormal proliferation of the synovial membrane and the accumulation of hemosiderin in the joint cavity. Although it can be surgically treated, PVNS tends to have a high recurrence rate, potentially resulting in chronic joint damage. CASE REPORT: we present the case of a young woman who experienced localized pain in her right knee due to a recurrence of PVNS. Magnetic resonance imaging revealed multiple multilobulated cystic lesions affecting the entire joint, including the ligaments. The patient underwent open surgical resection with a favorable clinical outcome. Histopathological examinations confirmed the absence of malignancy. CONCLUSION: while arthroscopy is typically the preferred treatment for PVNS, this case highlights the tendency for recurrence associated with this approach. Open surgical resection, supported by benign histopathological findings in this case, suggests a favorable long-term prognosis.

INTRODUCCIÓN: la sinovitis villonodular pigmentada (SVNP) es una enfermedad benigna que afecta la articulación de la rodilla, que causa una proliferación anormal de la membrana sinovial y la acumulación de hemosiderina en la cavidad articular. A pesar de que es posible tratarla mediante cirugía, la SVNP tiende a tener una alta tasa de recurrencia, lo que puede resultar en daño articular crónico. REPORTE DEL CASO: se presenta el caso de una mujer joven que experimentó dolor localizado en la rodilla derecha debido a una recurrencia de SVNP. La resonancia magnética reveló múltiples lesiones quísticas multilobuladas que afectaban a toda la articulación, incluyendo los ligamentos. La paciente fue sometida a una resección quirúrgica abierta, con una evolución clínica favorable. Los exámenes histopatológicos confirmaron la ausencia de malignidad. CONCLUSIÓN: aunque la artroscopía se considera el tratamiento de elección para la SVNP, este caso ilustra la tendencia a la recurrencia asociada con este enfoque. La resección quirúrgica abierta, respaldada por los hallazgos histopatológicos benignos en este caso, sugiere un pronóstico favorable a largo plazo.

PICO questions and DELPHI methodology for improving the management of patients with acute hepatic porphyria.

BACKGROUND: Acute hepatic porphyrias (AHPs) are a group of rare diseases that encompasses acute intermittent porphyria, variegate porphyria, hereditary coproporphyria, and 5-aminolaevulinic acid dehydratase deficiency porphyria. Symptoms of AHP are nonspecific which, together with its low prevalence, difficult the diagnosis and follow-up of these patients. MATERIAL AND METHODS: This project used DELPHI methodology to answer PICO questions related to management of patients with AHPs. The objective was to reach a consensus among multidisciplinary porhyria experts providing answers to those PICO questions for improving diagnosis and follow-up of patients with AHP. RESULTS: Ten PICO questions were defined and grouped in four domains: 1. Biochemical diagnosis of patients with AHP. 2. Molecular tests for patients with AHP. 3. Follow-up of patients with AHP. 4. Screening for long-term complications of patients with AHP. CONCLUSIONS: PICO questions and DELPHI methodology have provided a consensus on relevant and controversial issues for improving the management of patients with AHP.

Application of nanosilica in the construction industry: A bibliometric analysis using Methodi Ordinatio.

The number of publications related to the implementation of nanotechnology in the construction industry, and specifically to the application of nanosilica (SiO2), has had a constant increase in recent years. Based on this, in the present work, an analysis was carried out using bibliometric techniques, with the aim at characterizing the development of specialized literature and identifying the largest areas of growth in the field, maintaining hydrophobic nanosilica as the research guideline. This analysis acquired information from the Scopus and Web of Science (WoS) databases to compare bibliometric indicators of the publications. It should be noted that, even though bibliometric analysis is useful to identify the study areas of greatest interest, to complement this work, the implementation of a method that helped in the research process to obtain the most important bibliography was required. This study implemented Methodi Ordinatio, which helped to take a new direction. Therefore, based on this method, a list of articles cataloged and ranked is obtained, which is the basis for integrating the final bibliographic portfolio. •The study applies the Methodi Ordinatio to obtain a portfolio of the most relevant articles to guide the researchers' work.•Insightful information can be obtained using VOSviewer to analyze and visualize metadata of the bibliographic portfolio.•The study demonstrates how the alpha value in the InOrdinatio formula modifies the resulting portfolio.

Faraday waves on a nematic liquid crystal, and its coupling with Marangoni convection about the thermal phase transition.

Using a linear hydrodynamic theory, we demonstrate that Faraday waves occur in liquid crystalline fluids. The use of already experimentally known material parameters of a N-(4-methoxybenzylidene)-4-butylaniline liquid crystal allows us to confirm and realize the predictions of this theory. It provides the critical wave number and necessary driving acceleration at instability wave onset. Additionally, these observables experience an abrupt change originated by Marangoni convection due to the temperature gradient at the isotropic-nematic phase transition temperature. Correspondingly, the Marangoni number versus temperature also shows a sharp change in the transition temperature.

Magnetic viscoelastic behavior in a colloidal ferrofluid.

Based on the stochastic Langevin equation, we derived the total friction experienced by a tracer particle diffusing in thermally equilibrated colloidal magnetic fluids. This transport property leads to new expressions for its long-time diffusion coefficients, which satisfy an Einstein relation with the frictions of its translational and rotational Brownian motion. Further use of the nano-rheology theory allowed us to derive also the viscoelastic modulus of the colloid from such a property. The temporal relaxation of the viscoelasticity and transport coefficient turns out to be governed by the intermediate scattering function of the colloid. We derived an explicit formula for this evolution function within a hydrodynamic theory to include rotational degrees of freedom of the particles. In the limit of short frequencies, the viscous moduli render a new expression for the static viscosity. We found that its comparison with known experiments, at low and high concentration of ferroparticles in magnetite ferrofluids, is fair. However, comparing the predicted viscoelastic moduli with computer simulations as a function of frequency yields poor agreement.

[Vascular adrenal cyst causing difficult to control high blood pressure]. / Hipertensión arterial mal controlada secundaria a quiste vascular suprarrenal.

Hypertension is a prevalent disease in developed countries. Adrenal masses, and especially adrenal cysts, are a rare and usually asymptomatic finding, which can go unnoticed or be detected as incidental findings in imaging tests. These circumstances make the multidisciplinary approach mandatory. The case is presented on a 72 year-old woman with uncontrolled high blood pressure referred to the Urology Department due to the incidental finding of a right retroperitoneal mass. A functional and imaging study was performed, establishing a diagnosis of adrenal cyst causing hypertensive symptoms. A literature search was performed in order to assess diagnostic and therapeutic approaches. With the diagnosis of adrenal cyst causing uncontrolled high blood pressure, a right laparoscopic adrenalectomy was performed. After surgery the patient has maintained blood pressure within the normal range. A multidisciplinary approach is necessary for the management of rare diseases. The surgical approach, if possible, should be laparoscopic.

[Results of pulmonary embolism treatment in a tertiary hospital short stay unit. Is this the right place?]. / Resultados del tratamiento médico de la embolia de pulmón en una unidad de corta estancia de un hospital de tercer nivel: ¿es el lugar adecuado?

OBJECTIVES: To determine the mean stay (MS) of patients with pulmonary embolism (PE) in a thrombosis unit (TU) with a short stay unit (SSU) in a tertiary hospital. To compare the data collected with those of other hospitals in the same region, of other regions (Autonomous Communities [AACC]), and within the same hospital in the year before the SSU opened. MATERIAL AND METHODS: A descriptive retrospective observational study that included patients with a diagnosis of PE in the University Hospital Virgen de la Arrixaca (HCUVA) in 2012. These data were classified by hospital department, and used for calculating the mean stay. This was then compared with that of other hospitals in our region, with the rest of the regions, and with the data in 2007 (the last year without a TU). RESULTS: A total of 113patients with PE were included, 60 (53%) in the TU with an MS of 4.39, in Oncology, 7.45, and Internal Medicine (IM), 15.38days. There were no deaths in the TU and only 3 (5%) readmissions. Published data showed that the MS in all hospitals in our region was 8.25, 5.18 in our hospital, and higher in the rest of hospitals. The best AACC was the Basque Country with an MS of 6.85days. In 2007, there were 70patients with PE in the HCUVA, 34 (49%) in IM, with an MS of 8.50, Oncology 11 (31%) with an MS 9.64, and Chest Diseases 3 (4.3%) with an MS 19days, and with an overall mortality of 11% and a rate of readmissions in IM of 6%. CONCLUSION: The mean stay for a PE in the SSU of a TU was lower than in the rest of the hospital departments, lower than the rest hospitals of our region, lower than the rest of the regions, and lower than any department of our hospital before the SSU existed, without increasing the readmission or mortality rate.

Rhabdomyolysis after initial session of indoor cycling: analysis of 11 patients.

AIM: The aim of this paper was to highlight the special frequency of cases of rhabdomyolysis related to the practice of indoor cycling and to define the characteristics, course, and outcome of this disease. METHODS: Retrospective review of clinical histories of patients diagnosed with rhabdomyolysis after indoor cycling in our unit from January 2012 to April 2013. RESULTS: Eleven patients were analyzed. All patients, regardless of the degree of previous physical training, were diagnosed after a first session of indoor cycling. Mean age was 27.63 years (SD=5.74). Fifty-four percent were women. Creatine kinase (CK) levels gradually decreased in response to rest and intensive intravenous hydration. Only in two cases was renal failure observed, and in none were electrolyte disorders, disseminated intravascular coagulation (DIC) or compartmental syndrome detected. CONCLUSION: A first session of indoor cycling has become a common cause of rhabdomyolysis secondary to the physical exercise in recent years, which should alert those responsible for teaching this sport of the need for a gradual start under adequate hydration and environmental conditions, because although the condition has a benign course with adequate treatment and the complication rate is low, there are patients with increased susceptibility to very high CK blood levels requiring hospitalization for treatment and follow-up of possible complications.

Translational and rotational dynamics of colloidal particles in suspension: effect of shear.

We report a generalization of a nonequilibrium thermodynamic theory for the mesoscopic dynamics of radially symmetric interacting particles to anisotropic pairwise interactions and attain the one- and two-particle Fokker-Planck kinetics equations at a low-density limit that provides the translational-rotational coupling of their motion due to hydrodynamic interactions, from which we derived the balance equations of linear, angular momentum, and energy dissipation due to particle interactions and energy interchange with heat bath. In this low-density approximation, an already-known virial expression for the long-time translational collective diffusion coefficient of an orientational isotropic suspension in terms of the fluid equilibrium microstructure is recovered. An external shear flow induces, in the diffusive regime, vorticity effects into the rotational diffusion property of the colloidal particles. They manifest in the appearance of the particle's rotational viscosity due to vortex flow. The Smoluchowski equation that governs the dynamical relaxation of colloid microstructure due to particle's Brownian motion under stationary flow is provided.

Faraday waves on nematic liquid crystals: effect of Marangoni flow and thermal phase transition.

The parametric instability in nematic liquid crystal layers has been studied using linear stability theory. Using material parameters of typical nematics, the neutral stability curve and dispersion relation of a system that presents critical subharmonic waves is obtained. The critical acceleration and wave number of the unstable stationary waves are discontinuous at the nematic-isotropic transition temperature and conform to similar sharp changes experienced by the viscosities and surface tension as a function of temperature. Due to Marangoni flow the curve of the critical acceleration as a function of excitation frequency exhibits a minimum. If the Marangoni flow is neglected and the dynamical viscosity is increased, a monotonously increasing dependence of the acceleration in terms of oscillation frequency is observed. A bicritical instability is reached for a layer thickness of a few millimeters. A well-defined subharmonic wave is attained when the thickness of the layer is further increased. The dispersion relation of these waves displays a discontinuous shift at high frequencies due to alternating secondary thresholds of Faraday waves. At negligible external forcing we determined the dispersion relationship of thermal surface waves.

Faraday waves in smectic A liquid crystal layers.

We studied with linear stability analysis the onset of parametric waves on the surface of a smectic A liquid crystal. For thin Sm-A layers under an applied static magnetic field there are subharmonic-harmonic branches of surface waves at low modulating frequency of the driving acceleration and long wavelength. A semi-infinite Sm-A medium poses a dispersion relation with similar trends as for Newtonian liquids. When the external forcing is negligible there are two damped surface waves excited by thermal fluctuation of the interface, whereas in the absence of a magnetic field the dominant modes are of harmonic type for typical material parameters.

Counterion release and interaction of oppositely charged surfaces.

The interaction of two oppositely highly charged surfaces in an electrolyte solution and the number of released counterions from the slit between the surfaces were studied in terms of the anisotropic hypernetted chain and nonlinear Poisson-Boltzmann theories. Liquid theory predictions of the attractive pressure and release of counterions between the plates are larger than those of the mean field approach at low and moderate concentration of added salt. Further, at high salt concentration there is an opposite relationship of the two theories in their numerical results for the attractive pressure for all surface separations. These deviations of the predicted equilibrium properties arise both from the charge density and the ion size correlation effects included in hypernetted chain theory.

Structural thermodynamics of lamellar cationic lipid-DNA complex: DNA compressibility modulus.

We have studied theoretically the compressibility modulus B of DNA and complexation adsorption isotherms of DNA and lipids, as a function of DNA spacing d(DNA) and NaCl electrolyte concentration, respectively, in isoelectric states of lamellar DNA/cationic lipid (CL) self-assemblies. The electrostatic free energy derived from the Poisson-Boltzmann theory predicts partial agreement with measured B values for interhelical separations d(DNA)>33 A when use is made of a fit of hydration repulsion from bulk DNA hexagonal phases in solution. For lower interchain separations the prediction worsens due to the hydration interaction that overcomes the electrostatic contribution. An exact match of the system's counterion electrochemical potentials and the coions of salt in aqueous phase leads to the electrostatic part of the free energy that renders isotherms of d(DNA) versus ionic strength in qualitative consistency with general trends of available experimental data of CL-DNA complexes.

Phase evolution of lamellar cationic lipid-DNA complex: steric effect of an electrolyte.

The complexation isotherms of DNA plus lipids of a symmetric lamellar cationic lipid-DNA system were determined within a mean field free energy. The free energy incorporates the ion's finite size of NaCl simple electrolyte in solution and makes use of known structure data on this complex. The results for the predicted isotherms are in qualitative agreement with the trends of the experimental data for this property.

Transport properties of ferrofluids.

Long-time self-diffusion coefficients of ferrofluid suspensions are derived from an effective Langevin equation approach. The dependences of these transport properties on the volume fraction of particles and the strength of interparticle interaction are investigated. Strong reduction of the rotational and the translational Brownian motion of the particles is manifested upon increase of particle-particle interaction or ferrofluid concentration.

Electrostatic correlation force of discretely charged membranes.

The total force between two like charged surfaces is investigated as a function of counterion concentration in aqueous solution and surfaces distance of separation. A smooth and a discrete density of surface charge sigma(s) lead to differences in the force distance curve at high sigma(s), which are negligible for low surface charge. The total force per unit area with divalent counterions is an oscillating function of sigma(s). At fixed surfaces separation and region of attraction (increasing sigma(s)), there is a variation in its strength that results from a competition between the ideal kinetic and ion-ion correlation force components as predicted from the anisotropic hypernetted chain approximation.

Surface hydrodynamics on a freely standing layer of a polymer solution.

The dispersion relation and the power spectrum of the surface modes on a surface-active, freely standing film of a concentrated polymer solution are studied with a two-component fluid model of a viscoelastic material. The diagram of bending modes is obtained from an asymptotic analysis of the dispersion equation when the bending rigidity modulus is the main elastic effect on the layer interface. The resulting dynamical structure factor provides the characteristic squeezing and undulation surface modes of the interfaces driven by thermal fluctuations or by a weak external perturbation. The effect of interfacial and bulk elastic properties on the power spectrum of the scattered light is studied. In the regime of an elastic solution, finite-thickness effects and bulk elastic properties of the layer sustain a train of elastic peaks when the wavelength of thermal fluctuations is comparable to the thickness of the layer. Interfacial elasticity properties increase the strength and shift all resonance frequency peaks producing a less intense quasielastic spectrum around zero frequency.