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1.
Phys Rev Lett ; 133(7): 071803, 2024 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-39213579

RESUMEN

We report on a search for magnetic monopoles (MMs) produced in ultraperipheral Pb-Pb collisions during Run 1 of the LHC. The beam pipe surrounding the interaction region of the CMS experiment was exposed to 184.07 µb^{-1} of Pb-Pb collisions at 2.76 TeV center-of-mass energy per collision in December 2011, before being removed in 2013. It was scanned by the MoEDAL experiment using a SQUID magnetometer to search for trapped MMs. No MM signal was observed. The two distinctive features of this search are the use of a trapping volume very close to the collision point and ultrahigh magnetic fields generated during the heavy-ion run that could produce MMs via the Schwinger effect. These two advantages allowed setting the first reliable, world-leading mass limits on MMs with high magnetic charge. In particular, the established limits are the strongest available in the range between 2 and 45 Dirac units, excluding MMs with masses of up to 80 GeV at a 95% confidence level.

2.
Nature ; 602(7895): 63-67, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35110756

RESUMEN

Electrically charged particles can be created by the decay of strong enough electric fields, a phenomenon known as the Schwinger mechanism1. By electromagnetic duality, a sufficiently strong magnetic field would similarly produce magnetic monopoles, if they exist2. Magnetic monopoles are hypothetical fundamental particles that are predicted by several theories beyond the standard model3-7 but have never been experimentally detected. Searching for the existence of magnetic monopoles via the Schwinger mechanism has not yet been attempted, but it is advantageous, owing to the possibility of calculating its rate through semi-classical techniques without perturbation theory, as well as that the production of the magnetic monopoles should be enhanced by their finite size8,9 and strong coupling to photons2,10. Here we present a search for magnetic monopole production by the Schwinger mechanism in Pb-Pb heavy ion collisions at the Large Hadron Collider, producing the strongest known magnetic fields in the current Universe11. It was conducted by the MoEDAL experiment, whose trapping detectors were exposed to 0.235 per nanobarn, or approximately 1.8 × 109, of Pb-Pb collisions with 5.02-teraelectronvolt center-of-mass energy per collision in November 2018. A superconducting quantum interference device (SQUID) magnetometer scanned the trapping detectors of MoEDAL for the presence of magnetic charge, which would induce a persistent current in the SQUID. Magnetic monopoles with integer Dirac charges of 1, 2 and 3 and masses up to 75 gigaelectronvolts per speed of light squared were excluded by the analysis at the 95% confidence level. This provides a lower mass limit for finite-size magnetic monopoles from a collider search and greatly extends previous mass bounds.

3.
Phys Rev Lett ; 126(7): 071801, 2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33666471

RESUMEN

The MoEDAL trapping detector consists of approximately 800 kg of aluminum volumes. It was exposed during run 2 of the LHC program to 6.46 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point. Evidence for dyons (particles with electric and magnetic charge) captured in the trapping detector was sought by passing the aluminum volumes comprising the detector through a superconducting quantum interference device (SQUID) magnetometer. The presence of a trapped dyon would be signaled by a persistent current induced in the SQUID magnetometer. On the basis of a Drell-Yan production model, we exclude dyons with a magnetic charge ranging up to five Dirac charges (5g_{D}) and an electric charge up to 200 times the fundamental electric charge for mass limits in the range 870-3120 GeV and also monopoles with magnetic charge up to and including 5g_{D} with mass limits in the range 870-2040 GeV.

4.
Phys Rev Lett ; 123(2): 021802, 2019 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-31386510

RESUMEN

MoEDAL is designed to identify new physics in the form of stable or pseudostable highly ionizing particles produced in high-energy Large Hadron Collider (LHC) collisions. Here we update our previous search for magnetic monopoles in Run 2 using the full trapping detector with almost four times more material and almost twice more integrated luminosity. For the first time at the LHC, the data were interpreted in terms of photon-fusion monopole direct production in addition to the Drell-Yan-like mechanism. The MoEDAL trapping detector, consisting of 794 kg of aluminum samples installed in the forward and lateral regions, was exposed to 4.0 fb^{-1} of 13 TeV proton-proton collisions at the LHCb interaction point and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges equal to or above the Dirac charge are excluded in all samples. Monopole spins 0, ½, and 1 are considered and both velocity-independent and-dependent couplings are assumed. This search provides the best current laboratory constraints for monopoles with magnetic charges ranging from two to five times the Dirac charge.

5.
Phys Rev Lett ; 118(6): 061801, 2017 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-28234515

RESUMEN

MoEDAL is designed to identify new physics in the form of long-lived highly ionizing particles produced in high-energy LHC collisions. Its arrays of plastic nuclear-track detectors and aluminium trapping volumes provide two independent passive detection techniques. We present here the results of a first search for magnetic monopole production in 13 TeV proton-proton collisions using the trapping technique, extending a previous publication with 8 TeV data during LHC Run 1. A total of 222 kg of MoEDAL trapping detector samples was exposed in the forward region and analyzed by searching for induced persistent currents after passage through a superconducting magnetometer. Magnetic charges exceeding half the Dirac charge are excluded in all samples and limits are placed for the first time on the production of magnetic monopoles in 13 TeV pp collisions. The search probes mass ranges previously inaccessible to collider experiments for up to five times the Dirac charge.

7.
Rom J Intern Med ; 45(3): 293-7, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-18333364

RESUMEN

Pericarditis is clinically heterogeneous, with acute, subacute or chronic manifestations, and within each subset, with variable intensity of symptoms, from asymptomatic to a highly symptomatic disease. The etiology is also heterogeneous, often without a suggestive symptomatology. Depending or not on the etiology, sometimes through immune mechanisms, there can be some important complications, like recurrent/chronic pericarditis, life threatening acute tamponade or disabling constrictive pericarditis. The prognosis is highly dependent on a correct and precocious diagnosis (etiology included) and therapy. When the initial response to therapy is inadequate, the management of chronic or recurrent pericarditis is very difficult and also very important, with failure often leading to pericardial constriction, a difficult to treat complication of pericarditis.


Asunto(s)
Pericarditis/terapia , Enfermedad Aguda , Adulto , Electrocardiografía , Humanos , Cirrosis Hepática/inducido químicamente , Masculino , Pericardiocentesis , Pericarditis/diagnóstico , Pericarditis/etiología , Pronóstico , Toracoscopía
9.
Stroke ; 32(7): 1520-4, 2001 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-11441195

RESUMEN

BACKGROUND AND PURPOSE: This study aimed to determine the correlation of in vivo ultrasound measurements of intima-media thickening (IMT), lumen diameter, and cross-sectional area of the common carotid artery (CCA) with corresponding measurements obtained by gross pathology and histology. METHODS: Sixty-six moribund neurological patients (mean age 71 years) underwent B-mode ultrasound of the CCA a few days before death. During autopsy, carotid specimens were removed in toto. Carotid arteries were ligated and cannulated for injection of a hydrophilic embedding material under standardized conditions. The carotid bifurcation was frozen and cut manually in 3-mm cross slices. Digital image analysis was carried out to determine the diameter and the cross-sectional area of the frozen slices of the CCA. IMT was assessed by light microscope. Ultrasonic and planimetric data were compared. RESULTS: Mean measurements of lumen diameter and cross-sectional area were 7.13+/-1.27 mm and 0.496+/-0.167 cm(2), respectively, by ultrasound, and 7.81+/-1.45 mm and 0.516+/-0.194 cm(2), respectively, by planimetric analysis of the unfixed redistended carotid arteries (R(2)=0.389 and 0.497). The mean IMT was 1.005+/-0.267 mm by ultrasound and 0.67+/-0.141 mm histologically, resulting in a mean difference of -31%. CONCLUSIONS: Transcutaneous B-mode ultrasound provides a reliable approach for in vivo measurements of the cross-sectional area and, less exactly, of the lumen diameter of the CCA. Compared with histological results, in vivo ultrasound measurements of the IMT are systematically larger.


Asunto(s)
Arteriosclerosis/diagnóstico por imagen , Arteriosclerosis/patología , Enfermedades de las Arterias Carótidas/diagnóstico por imagen , Enfermedades de las Arterias Carótidas/patología , Arteria Carótida Común/diagnóstico por imagen , Ultrasonografía/métodos , Adulto , Anciano , Anatomía Transversal , Arteria Carótida Común/patología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Túnica Íntima/diagnóstico por imagen , Túnica Íntima/patología , Túnica Media/diagnóstico por imagen , Túnica Media/patología
11.
Stroke ; 31(5): 1123-7, 2000 May.
Artículo en Inglés | MEDLINE | ID: mdl-10797175

RESUMEN

BACKGROUND AND PURPOSE: Transcranial color-coded sonography (TCCS) via the suboccipital approach allows direct and continuous visualization of the basilar artery (BA). In this study, we intended to evaluate the ability of native TCCS in visualizing the length of the BA by means of a comparison with postmortem measurements. METHODS: The BA was prospectively studied by TCCS shortly before death (median 3 days) in 46 moribund neurological patients (mean+/-SD age 71.1+/-13.1 years). The length of the BA was determined by measuring the distance between the vertebrobasilar junction and the deepest available flow signal in the top of the BA. During autopsy, photos of the vertebrobasilar system were taken to evaluate the true anatomic length and variations of the course of BA in situ, eg, straight, curved, or S-shaped. RESULTS: Comparison of the in vivo ultrasound measurements of BA length and postmortem data was possible in 44 of 46 cases. In the 2 remaining patients, the BA was occluded. The mean insonation depth of the vertebrobasilar junction was found at 66.9+/-7.1 mm. The mean BA length was 21.5+/-6. 8 mm by color-coded duplex and 32.9+/-6 mm anatomically (P<0.0001). The mean difference between color mode and anatomic findings was 11. 3+/-6.4 mm in the case of a straight BA (35 cases) and 16.3+/-4.8 mm in an anatomically tortuous course of the BA (9 cases). CONCLUSIONS: Color duplex imaging enables correct visualization of the proximal two thirds of the BA, but only exceptionally of its distal one third. A tortuous course of the BA leads to an underestimation of its anatomic length.


Asunto(s)
Arteria Basilar/diagnóstico por imagen , Arteria Basilar/patología , Cambios Post Mortem , Humanos , Ultrasonografía Doppler en Color
12.
Ann Allergy Asthma Immunol ; 82(6): 567-73, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10400485

RESUMEN

BACKGROUND: Little is known about the prevalence of atopy in adults with recurrent respiratory infections and IgG deficiency. OBJECTIVE AND METHODS: To elucidate this aspect, we skin-tested 95 consecutive adults with respiratory infections, subnormal levels of IgG subclasses or common variable immunodeficiency and usually poor response to vaccination. In 50 subjects we also measured total IgE. RESULTS: We found 67 subjects with IgG subclass deficiency, 21 subjects with mild (partial) and 5 with usual common variable immunodeficiency, and 2 subjects with functional IgG deficiency. Atopy was encountered in 42/95 subjects, 33/44 (75%) with asthma, 7/19 (38%) with isolated rhinosinusitis, 1/27 (4%) with chronic obstructive lung disease, and 1/5 (20%) with both the latter disease and asthma, respectively. Atopy was preferentially clustered in subjects with asthma (P < .05) who were less than 40 years of age (P < .05) and nonsmoking. Atopy was not affected by the type of IgG deficiency, unless it was usual common variable immunodeficiency, in which case the skin tests tended to be negative (4/5). Total IgE was within normal range but less elevated than usually seen in asthma or chronic obstructive lung disease. Total IgE was independent of the type of IgG deficiency, except for usual common variable immunodeficiency in which it remained < 10 IU/mL. CONCLUSIONS: In adults with symptomatic IgG deficiency, the prevalence of immediate hypersensitivity and its modulation by age and smoking are similar to the referred, non-IgG deficient population; however, total IgE may be lower in the former than in the latter. In common variable immunodeficiency, consistent with the literature data, both the prevalence of atopy and serum total IgE are decreased.


Asunto(s)
Hipersensibilidad Inmediata/complicaciones , Deficiencia de IgG/complicaciones , Infecciones del Sistema Respiratorio/inmunología , Adulto , Asma/inmunología , Humanos , Hipersensibilidad Inmediata/epidemiología , Inmunoglobulina E/análisis , Inmunoglobulina E/deficiencia , Enfermedades Pulmonares Obstructivas/inmunología , Prevalencia , Valores de Referencia , Rinitis/inmunología , Sinusitis/inmunología , Pruebas Cutáneas
13.
Cytokine ; 9(4): 284-7, 1997 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-9112337

RESUMEN

Interleukin 1 beta (IL-1) and tumour necrosis factor alpha (TNF) are important for the beta cell lysis in insulin-dependent diabetes mellitus (IDDM), while IL-1 receptor antagonist (IL-1ra) is considered protective by blocking the effects of IL-1. Serum concentrations and ex-vivo production of IL-1, TNF and IL-1ra were examined in 10 newly diagnosed IDDM (ND-IDDM) patients, and compared with 11 long-standing IDDM (LS-IDDM) patients and 14 healthy volunteers. Ex-vivo LPS-stimulated production of IL-1 in ND-IDDM patients was significantly increased compared with LS-IDDM patients and healthy controls, while TNF and IL-1ra synthesis did not differ significantly. IL-1ra/IL-1 ratio was significantly decreased in ND-IDDM, and returned to normal values in the LS-IDDM group. Circulating concentrations of IL-1ra in LS-IDDM patients were increased. These data suggest a proinflammatory imbalance in ND-IDDM patients and this may play an important role in beta cell loss.


Asunto(s)
Diabetes Mellitus Tipo 1/diagnóstico , Interleucina-1/sangre , Receptores de Interleucina-1/antagonistas & inhibidores , Sialoglicoproteínas/sangre , Factor de Necrosis Tumoral alfa/química , Enfermedad Aguda , Adolescente , Adulto , Niño , Enfermedad Crónica , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/metabolismo , Femenino , Humanos , Proteína Antagonista del Receptor de Interleucina 1 , Interleucina-1/biosíntesis , Interleucina-1/metabolismo , Masculino , Sialoglicoproteínas/biosíntesis , Sialoglicoproteínas/metabolismo , Factores de Tiempo , Factor de Necrosis Tumoral alfa/biosíntesis , Factor de Necrosis Tumoral alfa/metabolismo
14.
Chirurgia (Bucur) ; 92(2): 105-8, 1997.
Artículo en Rumano | MEDLINE | ID: mdl-9296752

RESUMEN

The authors describe the technique of thoracic sympathectomy by thoracoscopic approach in the variant in which the sympathetic chain is divided between T4 and T5 sympathetic ganglion associated with the division of the gray and white rami communicantes of the T2-T3-T4 sympathetic ganglions. The article emphasizes the importance of the 2nd sympathetic ganglion in the regulation of the blood circulation of the arm and the advantages of the thoracoscopic approach for this type of intervention.


Asunto(s)
Ganglionectomía/métodos , Toracoscopía/métodos , Adulto , Ganglionectomía/instrumentación , Humanos , Masculino , Toracoscopios , Tromboangitis Obliterante/cirugía
15.
Radiat Meas ; 28(1-6): 463-6, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-11541795

RESUMEN

CR-39 nuclear track detectors have been used in this experiment to study the killing effect of low energy protons on V79-753B Chinese hamster cells and to monitor the proton beam. The estimated surviving fractions and the beam parameters are comparable to those found with conventional electronic devices. The surviving fractions fitted by the linear quadratic model support the idea of single-hit mechanism for the cell killing.


Asunto(s)
Células Cultivadas/efectos de la radiación , Protones , Monitoreo de Radiación/instrumentación , Animales , Supervivencia Celular/efectos de la radiación , Cricetinae , Cricetulus , Relación Dosis-Respuesta en la Radiación , Transferencia Lineal de Energía , Aceleradores de Partículas , Plásticos , Polietilenglicoles , Dosis de Radiación , Efectividad Biológica Relativa , Temperatura
16.
Pulm Pharmacol ; 7(5): 333-41, 1994 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7626920

RESUMEN

To determine whether a mu opiate agonist can constrict the human airways, the dose of codeine (C) or histamine (H) producing a 40% decrease (PD40) in specific airway conductance (SGAW) was measured in 17 asthmatic and 14 normal subjects. Then, the subjects were skin tested with C and H, and the effect of naloxone (N) and chlorpheniramine (CP) on PD40-C was assessed. In five asthmatic subjects responding to less than 5 mg (16.6 mumol) inhaled C, SGAW was also recorded after oral administration (30 mg) and pharyngeal spraying (5 mg) of C. PD40-C could be determined in 11 of the 17 asthmatics but in none of the normal subjects. This constrictor effect lasted less than 15 min, was unrelated to resting airway caliber, and required a relatively high bronchial sensitivity to H (PD40-H usually less than 0.2 mumol) and high doses of C (11.93 +/- 12.0 mumol). However, in C responders, PD40-C and PD40-H were unrelated. C-induced bronchoconstriction was blunted by N in a dose-dependent fashion and to a mild and inconsistent degree, by CP. Pharyngeal spraying or oral challenge with C failed to change SGAW. Skin sensitivity to H and C was similar in C-responders and non-responders. In conclusion, large doses of inhaled C constrict the airways of asthmatic subjects highly sensitive to H. This effect seems mediated through (mu?) opiate receptors located bronchially rather than centrally, pharyngeally or in the skin. In C-induced bronchoconstriction H liberation plays a contributory but minor role. Skin and bronchial sensitivity to C are unrelated.


Asunto(s)
Asma/tratamiento farmacológico , Bronquios/efectos de los fármacos , Broncoconstrictores/farmacología , Codeína/farmacología , Receptores Opioides mu/efectos de los fármacos , Adolescente , Adulto , Broncoconstricción/efectos de los fármacos , Histamina/farmacología , Humanos , Persona de Mediana Edad , Naloxona/farmacología , Factores de Tiempo
17.
Pneumoftiziologia ; 43(3-4): 217-20, 1994.
Artículo en Rumano | MEDLINE | ID: mdl-7767108

RESUMEN

A case of diaphragmatic pathology is presented consisting in transdiaphragmatic penetration of abdominal viscera. It raised problems of differential diagnosis with other intrapleural pathology. X-ray aspects should not be interpreted without including them into the general clinical and laboratory data in order to avoid errors of diagnosis and treatment.


Asunto(s)
Hernias Diafragmáticas Congénitas , Adulto , Diagnóstico Diferencial , Errores Diagnósticos , Femenino , Hernia Diafragmática/diagnóstico por imagen , Hernia Diafragmática/cirugía , Humanos , Pleuresia/diagnóstico por imagen , Pleuresia/tratamiento farmacológico , Radiografía Torácica , Recurrencia , Factores de Tiempo
18.
Ann Allergy ; 73(1): 43-55, 1994 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8030803

RESUMEN

The discriminant ability of six provocation doses of histamine, PD10, PD15, PD20, PD10T, PD20C, and PD40 has been reported. The subscript connotes -%delta SGaw (PD40), -%delta FEV1 > or = 10% (PD10T), -%delta measured with the lowest (PD20C) or the best FEV1 (PD10, PD15). To explain the differing discriminant ability of the six provocation doses (PD20 = PD15 > PD10T = PD40 > PD20C > PD10), this study analyzed the role of % delta/variability, log dose-response curve, airway hysteresis and the test itself in the original group of 20 normal and 20 asthmatic subjects. For provocation doses measured with the best FEV1, the discriminant ability was related to the ratio %delta/variability and the frequency with which various provocation doses were located on the steep portion of the log dose-response curve; these two parameters and the steepness of the latter were similar in normal and asthmatic subjects. The low discriminant ability of PD20C did not depend on %delta/variability or steepness of the log dose-response curve but on its high rate of false positive results. The lower discriminant ability of PD40 than PD20 or PD15 could not be related to any of the factors analyzed. In conclusion, the factors influencing the calculation of provocation doses affect differently the discriminant ability of these endpoints: (1) %delta/variability and steepness of log dose-response curve influence the provocation doses based on best FEV1. (2) Airway hysteresis reduced the proportion of normals with asthmatic provocation doses, increasing the rate of false positive results with PD20C, based on the smallest FEV1. (3) The nature of the tes, SGaw versus FEV1, affects the discriminant ability of PD40 in a still obscure way.


Asunto(s)
Asma/fisiopatología , Histamina , Pruebas de Provocación Nasal , Asma/diagnóstico , Asma/epidemiología , Análisis Discriminante , Relación Dosis-Respuesta a Droga , Volumen Espiratorio Forzado , Humanos
19.
Chest ; 105(4): 1066-72, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8162726

RESUMEN

In 42 adults with recurrent respiratory infections (RRI) and common variable immunodeficiency or immunoglobulin G (IgG) subclass deficiency, the results of pulmonary function tests were related to factors apt to produce airway obstruction: serum concentration of IgG and IgG subclasses, various features of acute RRI (number/year, time from onset to diagnosis, episodes of pneumonia, etc) and type of chronic lung disease (smoking and nonsmoking related chronic bronchitis, episodic wheezing, and bronchiectasis). Compared with nonsmokers, usually less than 40 years of age, the patients above 40 had smoking-related chronic bronchitis and had obstruction (%FEV1/forced vital capacity [FVC] 55.3 +/- 8.1 vs 80.1 +/- 4.5), hyperinflation (residual volume 182.7 +/- 22.7 percent vs 109.7 +/- 8.8 percent of pred) hypoxemia (66.6 +/- 5.8 vs 83.4 +/- 4.2 mm Hg) and impaired carbon monoxide transfer (65.5 +/- 9.1 percent vs 93.3 +/- 5.8 percent). The features of acute or chronic RRI, the time from onset to diagnosis (< 10 yr in the entire group), the type of IgG deficiency or the serum concentration of the deficient protein did not correlate with substantial obstruction (FEV1/FVC < 70%). In conclusion, in adults with IgG deficiency and RRI for less than 10 yr, smokers with chronic bronchitis rather than nonsmokers develop substantial airway obstruction.


Asunto(s)
Deficiencia de IgG/complicaciones , Enfermedades Pulmonares Obstructivas/complicaciones , Infecciones del Sistema Respiratorio/complicaciones , Adulto , Bronquitis/complicaciones , Inmunodeficiencia Variable Común/complicaciones , Femenino , Volumen Espiratorio Forzado , Humanos , Enfermedades Pulmonares Obstructivas/diagnóstico , Masculino , Persona de Mediana Edad , Recurrencia , Fumar , Capacidad Vital
20.
Pneumoftiziologia ; 43(1-2): 35-9, 1994.
Artículo en Rumano | MEDLINE | ID: mdl-7734985

RESUMEN

The study starts with presentation of present day knowledge of the disease. Its features are predominantly X-ray images consisting mainly in a round or ovular, usually solitary formation ("coin lesion"). The clinical expression of the disease is usually very discrete, the general state unmodified. The X-ray evidencing follows a routine examination. 3 cases of personal observations are presented. All cases were solved by surgery, by removal of tumour. Etiology is fixed by histological examination of surgery specimen. All aspects risen by the differential diagnosis are largely discussed focusing on lung granuloma (e.g. tuberculoma) lung abscess, limited pneumonia, lipoid pneumonia a.o. Hamartomas are of mesenchymal origin, they are not considered just as tumours but very similar to "tumour-like", without invasive evolution.


Asunto(s)
Hamartoma/diagnóstico , Enfermedades Pulmonares/diagnóstico , Adulto , Anciano , Femenino , Hamartoma/patología , Hamartoma/cirugía , Humanos , Pulmón/patología , Enfermedades Pulmonares/patología , Enfermedades Pulmonares/cirugía , Masculino , Toracotomía
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