Classical harmonic three-body system: an experimental electronic realization.

The classical three-body harmonic system in [Formula: see text] ([Formula: see text]) with finite rest lengths and zero total angular momentum [Formula: see text] is considered. This model describes the dynamics of the [Formula: see text] near-equilibrium configurations of three point masses [Formula: see text] with arbitrary pairwise potential [Formula: see text] that solely depends on the relative distances between bodies. It exhibits an interesting mixed regular and chaotic dynamics as a function of the energy and the system parameters. The corresponding harmonic quantum system plays a fundamental role in atomic and molecular physics. In this work we report on a novel electronic experimental realization of the model as a complementary tool to analyze the rich dynamics of the classical system. Our setup allows us to experimentally explore different regions of behavior due to the fact that the intrinsic parameters and initial states of the system are independently set by voltage inputs. Chaotic and periodic motions are characterized employing time series, phase planes, and the largest Lyapunov exponents as a function of the energy and system parameters. The results show an excellent qualitative as well as quantitative agreement between theory and experiment.

Association of QRS Complex Fragmentation with QT Interval Prolongation in Patients with Ischemic Heart Disease.

BACKGROUND: The fragmented QRS complex (FQRS) was found to be associated to malignant ventricular arrhythmias and sudden death in patients with hypertrophic cardiomyopathy and other entities. There is scant data available correlating the presence of FQRS with QT interval prolongation in patients with ischemic heart disease (IHD). METHODS: A descriptive, retrospective, cross-sectional study was performed in 123 patients with IHD to analyze and correlate the presence of FQRS with QT interval prolongation in the conventional 12-leads electrocardiogram in patients with documented chronic IHD. RESULTS: There were 62% male patients. The mean age was 63.8±12.6 years. Thirty six (44%) patients had fragmented QRS (64% men and 36% women). The duration of QT and QTc, the mean values were 413±59ms, and 463±67ms, respectively. Of the 36 patients with FQRS, 23 patients have prolongation of the QTc interval, and 13 patients did not present it. Of the 45 patients without FQRS, 21 of them have prolongation of the QTc interval, and 24 patients did not have it. These data resulted in a sensitivity of 52% with a moderate SnNout, a specificity of 65% with moderate SpPin, a positive predictive accuracy of 64%, a negative predictive accuracy of 53%. These data resulted in a prevalence of 54%. CONCLUSION: the presence of FQRS in the ECG has a moderate sensitivity and specificity, as well as, moderate negative and positive predictive value of the existence of QT interval prolongation in patients with ischemic heart disease.

Rol de enfermería en el área COVID en un hospital pediátrico de alta complejidad / The role of nurses in the COVID area in a pediatric tertiary-care hospital

Introducción: la pandemia por SARS-CoV-2 planteó un desafío para todo el equipo de salud. Fue necesario analizar y pensar en este contexto el rol de enfermería en la atención y cuidados del paciente y su familia. Los procesos asistenciales debieron adaptarse a nuevas y diversas situaciones que generaron la atención de pacientes en su mayoría con comorbilidades asociadas. El objetivo del trabajo fue describir el rol de enfermería y la implementación de diversos protocolos y procesos de atención de pacientes en salas de internación pediátrica del área COVID de un hospital de alta complejidad. Material y métodos: se realizó un estudio retrospectivo y descriptivo sobre el personal de enfermería que participó en la atención de casos sospechosos o confirmados de COVID-19 durante la pandemia y los protocolos implementados para los cuidados de enfermería. Resultados: solo el 52.5% (n 79) del personal tenía experiencia mayor a tres años, el 75% (n: 113) pertenecían al género femenino, el 47% (n: 71) eran licenciados en enfermería. Conclusiones: Los profesionales enfermeros han logrado mediante sus fortalezas disciplinares dar respuesta a las necesidades del paciente pediátrico y su familia frente a la crisis sanitaria. Las competencias desarrolladas en la administración de los recursos disponibles, la adaptación, flexibilidad a los procesos y líneas estratégicas en tiempo real, posicionan al enfermero como un valor fundamental en el cuidado asistencial (AU)

Introduction: The SARS CoV-2 pandemic posed a challenge for the entire healthcare team. It was necessary to analyze and reflect on the role of nursing in the care of patients and their families in this context. Care processes had to be adapted to new and diverse situations that were generated by the care for patients who usually had associated comorbidities. The aim of the study was to describe the nursing role and the implementation of different protocols and processes for patient care in pediatric inpatient wards in the COVID area of a tertiary-care hospital. Material and methods: a retrospective descriptive study was conducted in the nursing personnel involved in the care of suspected or confirmed cases of COVID-19 during the pandemic and the protocols implemented for nursing care. Results: only 52.5% (n: 79) of the personnel had more than three years of experience, 75% (n: 113) were female, and 47% (n: 71) had a nursing degree. Conclusions: Through their disciplinary strengths, nursing professionals have been able to respond to the needs of pediatric patients and their families in the face of the health crisis. The skills developed in the management of available resources, adaptation, and flexibility to processes and real-time strategies, have positioned nurses as a fundamental factor in healthcare (AU)

Hypothalamic Effects of Tamoxifen on Oestrogen Regulation of Luteinising Hormone and Prolactin Secretion in Female Rats.

Oestradiol (E2) acts in the hypothalamus to regulate luteinising hormone (LH) and prolactin (PRL) secretion. Tamoxifen (TX) has been extensively used as a selective oestrogen receptor modulator, although its neuroendocrine effects remain poorly understood. In the present study, we investigated the hypothalamic effects of TX in rats under low or high circulating E2 levels. Ovariectomised (OVX) rats treated with oil, E2 or TX, or E2 plus TX, were evaluated for hormonal secretion and immunohistochemical analyses in hypothalamic areas. Both E2 and TX reduced LH levels, whereas TX blocked the E2 -induced surges of LH and PRL. TX prevented the E2 -induced expression of progesterone receptor (PR) in the anteroventral periventricular nucleus (AVPV) and arcuate nucleus (ARC), although it did not alter PR expression in OVX rats. TX blocked the E2 induction of c-Fos in AVPV neurones, consistent with the suppression of LH surge. However, TX failed to prevent E2 inhibition of kisspeptin expression in the ARC. In association with the blockade of PRL surge, TX increased the phosphorylation of tyrosine hydroxylase (TH) in the median eminence of OVX, E2 -treated rats. TX also precluded the E2 -induced increase in TH expression in the ARC. In all immunohistochemical analyses, TX treatment in OVX rats caused no measurable effect on the hypothalamus. Thus, TX is able to prevent the positive- but not negative-feedback effect of E2 on the hypothalamus. TX also blocks the effects of E2 on tuberoinfundibular dopaminergic neurones and PRL secretion. These findings further characterise the anti-oestrogenic actions of TX in the hypothalamus and provide new information on the oestrogenic regulation of LH and PRL.

Wandering spleen presenting as an adnexal mass.

Wandering spleen is an uncommon entity. The authors report the fifth case of wandering spleen presenting as a left adnexal mass.

Exchange nailing for failure of initially rodded tibial shaft fractures.

This retrospective study evaluated 32 patients who underwent exchange nailing for initially rodded nonunited tibial shaft fractures during a 5-year period. High-energy trauma accounted for 22 fractures; 19 fractures were open. An unreamed nail was initially used to stabilize all but 2 fractures. Implant failure occurred in 31% of fractures, mostly in distal-third fractures, with a failure rate of 34%. Average time from injury to exchange nailing was 36 weeks (range: 6-148 weeks) and consisted of closed reamed nailing and fibulectomy in 27 cases. Healing occurred an average of 20 weeks (range: 6-47 weeks) after postexchange nailing in 27 (84%) fractures. Four (12.5%) fractures healed after additional procedures. There was 1 persistent nonunion. Factors leading to delay in union time included comminution, healed fibula, and proximal location. Multiple regression analysis using survival data at P<.05 showed a significant correlation between fracture configuration and fixation method (locked, dynamic, and unlocked) on time to union. Exchange nailing with closed reaming and fibulectomy is a viable option for treating failures of primarily nailed tibial fractures. Increased stability and stimulation of arrested bone healing may account for the good outcome. The advantages of repeat reamed nailings should be weighed against the possible adverse effect of reaming on bone vascularity.

[Conservative elective surgery in kidney neoplasms]. / Chirurgia conservativa di elezione nelle neoplasie renali.

After the good results of "necessary" conservative surgery in the treatment of kidney neoplasms (bilateral neoplasms, congenital, acquired or functional solitary kidney), conservative surgery itself has been employed as elective treatment in selected cases presenting without the overmentioned problems. The authors report two cases of elective conservative surgery in kidney neoplasm with good results after 18 and 24 months.

Brote de Ralstonia mannitolilytica a partir de bacteriemias asociadas a catéteres implantables y semiimplantables en un hospital pediátrico / Outbreak of Raistonia mannitolilytica by implantable and semi-implantable catheter-related bacteremia in a pediatric hospital

Ralstonia mannitolilytica junto con Ralstonia pickettii han sido asociadas con brotes hospitalarios relacionados con la contaminación de algún dispositivo o fluido. El objetivo de este trabajo fue describir un brote por R. mannitolilytica a partir de bacteriemias asociadas a catéteres implantables y semiimplantables ocurrido en un hospital pediátrico de alta complejidad y evaluar la utilidad del empleo de métodos moleculares para su investigación.Se detectó la presencia de bacilos gram negativos no fermentadores, con igual antibiotipo, en hemocultivos y retrocultivos a partir de dos pacientes que tenían catéteres implantables y estaban atendidos en una misma área del hospital. Se realizaron estudios microbiológicos de muestras de frascos de heparina, soluciones de dextrosa y soluciones antisépticas con resultado negativo. Algunos pacientes tuvieron signos y/o síntomas clínicos de bacteriemia al habilitar los catéteres para su uso. Se citaron para su estudio a todos los pacientes que habían tenido un procedimiento de apertura y cierre de catéter durante las fechas cercanas a los hallazgos en hemocultivos (N expuestos = 45). Ocurrieron 17 casos (infectados), a partir de los cuales se analizaron 23 aislamientos, en los que se pudo documentar la presencia de R. mannitolilytica (23 aislamientos). Por métodos moleculares se determinó que los aislamientos provenientes de muestras de pacientes involucrados en el brote se encontraban estrechamente relacionados y podrían representar una misma cepa o clon. Por evidencia circunstancial se consideró a la "solución heparínica de cierre" como fuente posible del brote (AU)

Both Ralstonia mannitolilytica and Ralstonia pickettii have been associated with hospital outbreaks due to device or fluid contamination. The aim of this study was to describe an implantable- or semi-implantable-catheter-related bacteremia outbreak by R. mannitolilytica in a tertiary-care hospital and to assess the usefulness of molecular analysis for the identification of the organism. Non-fermenting gram-negative bacilli, with identical antibiotypes, were detected in hemocultures of two patients with implantable catheters in the same hospital area. Microbiological studies of heparin and dextrose and antiseptic solution vials were negative. Some of the patients had clinical signs and/or symptoms of bacteremia when the catheter was prepared for use. All patients who underwent a procedure of accessing or locking the port of the catheter around the time of the positive hemoculture findings were contacted (N exposed = 45). Seventeen infections were detected, of which 23 isolates were analyzed. The presence of R. mannitolilytica was recorded in 23 isolates. Molecular analysis showed that the isolates from the samples of the patients involved in the outbreak were closely related and might represent the same strain or clone. Circumstantial evidence suggested that the heparin-lock solution may have been the source of the outbreak (AU)

Infecciones asociadas a dispositivos de soporte circulatorio mecánico / Ventricular assist device-related infections

El dispositivo de asistencia ventricular asistida (DAV) se utiliza como terapéutica final o puente al trasplante cardíaco. La tasa de complicaciones infecciosas asociada a este dispositivo es elevada. La experiencia con este tipo de complicación en pediatría es escasa. Objetivo: conocer las características clínicas, microbiológicas y de evolución de pacientes con DAV. Material y métodos: pacientes internados en el Hospital Garrahan desde marzo del 2006 a marzo 2014 con DAV. Estudio retrospectivo, descriptivo. Se analizaron: edad, sexo, tipo de enfermedad de base, características clínicas, microbiológicas y de evolución de los pacientes con DAV. Resultados: se incluyeron 33 pacientes. La mediana de edad fue 79 meses (rango:13-133). La indicación de colocación del DAV fue miocardiopatía dilatada en el 81.8% (27). Los días acumulados de uso del DAV fue de 4.638 días. Diecisiete pacientes (51.5%) presentaron 23 episodios de infección. La infección pericánula se presentó 10 casos (43.4%), bacteriemias primarias en 4 (17.4%), bacteriemia asociada a catéter de corta permanencia 5 (21.7%), mediastinitis 3 (13%) y un caso de sepsis (4.3%). Los microorganismos prevalentes fueron los cocos gram positivos. Fallecieron 12 pacientes en DAV a la espera del trasplante, uno de ellos con sepsis y mediastinitis por S. aureus meticilino sensible. Conclusiones: La infección asociada a DAV fue frecuente en nuestros pacientes y dentro de ellas la infección pericánula fue la más común. Los cocos gran positivos fueron los microorganismos predominantes. Los pacientes con mayor tiempo de permanencia del DAV presentaron varios episodios de infección. Las infecciones asociadas al DAV no impidieron el éxito del trasplante cardíaco (AU)

Programa de prevención de las bacteriemias asociadas a catéteres venosos centrales / Program for prevention of central venous catheter-related bacteremia

Introducción: Las infecciones son las complicaciones más importantes asociadas al uso de los Catéteres Venosos Centrales (CVC), representan un riesgo 20 veces mayor de bacteriemias que los catéteres venosos periféricos. El objetivo de este estudio fue evaluar el efecto de la implementación de un paquete de medidas o "bundle" en las infecciones asociadas a catéteres venosos centrales (BACT- CVC) en la Unidad de Cuidados Intensivos del Hospital Garrahan (UCI). Métodos: El Programa de Intervención para disminuir las bacteriemias asociadas a catéteres venosos centrales requirió de la aplicación de cuatro paquetes de medidas y un subprograma para aumentar la adherencia a la higiene de manos. Se aplicó en todas las UCI, pero en el presente estudio se presenta como modelo de referencia el que se llevó a cabo en una de ellas. Período del estudio: se compararon 2 períodos: basal (1º Agosto de 2008 - 31 de Diciembre de 2009) y intervención (1º de Enero 2010 al 31 de Diciembre de 2011). La tasa de BACT - CVC se calculó en concordancia con los protocolos utilizados por el sistema NHSN - CDC de los Estados Unidos y el sistema nacional VIHDA. La base de datos utilizada para el estudio fue el software provisto por el programa VIHDA. Se compararon las tasas de BACT - CVC en el período previo y posterior a las intervenciones realizadas. Para el análisis estadístico se utilizó el programa EPIINFO. Se consideró estadísticamente significativo un valor de p < 0.05. Resultados: en el primer período (Agosto 2008 - Diciembre 2009) se produjeron un total de 44 BACT - CVC, con una tasa promedio de 9.64 BACT-CVC por 1000 días-catéter versus 17 BACT - CVC, tasa promedio de 4.41 BACT-CVC por 1000 días-catéter en el período en que se desarrolla el programa de intervención. Esta disminución resulta estadísticamente significativa (Chi cuadrado; valor P= 0,0048; RR 0,46; IC 95%: 0,26 - 0,80). Conclusiones: La aplicación de los combos y el subprograma para mejorar la adherencia a la higiene de manos según orientación de la OMS y aplicando Estrategias Multimodales, resultaron en una mejora significativa en la tasa de BACT- CVC (AU)

Introduction: Infections are the main complication associated with the use of central venous catheters (CVC), accounting for an infection risk about 20 times that of peripheral venous catheters. The aim of this study was to assess the effect of the implementation of sets of measures or "bundle" for the prevention of CVC-associated bacteremia (CVC-BACT) in the ICU. Methods: The intervention program for the reduction of CVC-BACT consisted of four sets of measures and a sub-program to increase adherence to hand hygiene. Bundle use was started in all PICUs, however, in this study implementation of the program in one of them was used as a reference model. Study period: Two periods were compared: Baseline (August 1, 2008 ­ December 31, 2009) and intervention (January 1, 2010 ­ December 31, 2011). The CVC-BACT rate was calculated according to the NHSN-CDC protocols of the United States and the Argentine VIHDA system. For the data base of the study software provided by the VIHDA program was used. CVC-BACT rates before and after the intervention period were calculated. For statistical analysis the EPIINFO program was used. A p < 0.05 was considered significant. Results: In the first period (August 2008 - December 2009) 44 CVC-BACT occurred, with a mean CVC-BACT rate of 9.64 per 1000 catheter days versus 17 CVC-BACT, mean CVC-BACT rate of 4.41 per 1000 catheter days, in the intervention period. This decrease was statistically significant (Chi square 7.94; p = 0.0048; RR 0.46; 95% CI: 0.26 ­ 0.80). Conclusions: Bundle use and the subprogram for better adherence to hand hygiene, according to WHO guidelines and applying multimodal strategies, resulted in a significantly lower CVC-BACT rate (AU)

Confined helium atom low-lying S states analyzed through correlated Hylleraas wave functions and the Kohn-Sham model.

Calculation including the electron correlation effects is reported for the ground 1 1S and lowest triplet 1 3S state energies of the confined helium atom placed at the center of an impenetrable spherical box. While the adopted wave-functional treatment involves optimization of three nonlinear parameters and 10, 20, and 40 linear coefficients contained in wave functions expressed in a generalized Hylleraas basis set that explicitly incorporates the interelectronic distance r12, via a Slater-type exponent and through polynomial terms entering the expansion, the Kohn-Sham model employed here uses the Perdew and Wang exchange-correlation functional in its spin-polarized version within the local-density approximation (LDA) with and without the self-interaction correction. All these calculations predict a systematic increase in the singlet-triplet energy splitting toward the high confinement regime, i.e., when the box radius is reduced. By using the variational results as benchmark, it is found that the LDA underestimates the singlet-triplet energy splitting, whereas the self-interaction correction overestimates such a quantity.

The orthopaedic surgeon and manufacturing industry relationship. Ethical guidelines.

Orthopaedic surgery has progressed over the years because of innovative work of pioneering orthopaedic surgeons; new developments in internal fixation techniques and implants codeveloped with the orthopaedic manufacturing industry have improved treatment greatly. This article analyzes and reviews the relationship of orthopaedic surgeons to the orthopaedic implant industry, analyzing three broad categories of the relationship: (1) physicians receiving gifts from industry; (2) the orthopaedic industry's financial support of educational and research endeavors of academic trauma and other centers; and (3) the relationship of the industry with innovators in the field of orthopaedic surgery by retainer fees, royalties, and stock options from industry. The ethical relationship requires: (1) putting the patient's concerns first above vested interests; (2) an awareness of a potential for abuse; and (3) a level of awareness of the relationship and the ability to explain and inculcate this relationship in the teaching program of young residents to maintain the high standards that have been set.

Factors related to foreign nurse graduates' test-taking performance.

The essential problem in the immigration of foreign nurse graduates (FNGs) to the United States is their poor incidence of success in meeting state licensure requirements. Factors responsible for the low success rate include nonfamiliarity with multiple-choice format in tests, lack of English proficiency, and anxiety. This study gathered information regarding FNGs' experience in taking state board examinations and demonstrated relationships between factors identified above and scores obtained by FNGs on achievement tests developed according to the American Nurses' Association Blueprint for Licensing Examination for R.N. Licensure.

Effect of injected long-acting epinephrine in addition to aerosolized albuterol in the treatment of acute asthma in children.

The additional effect, if any, of subcutaneous, long-acting epinephrine (Sus-Phrine) to aerosolized albuterol for acute pediatric asthma was studied. Over an eight-month period, patients were enrolled in a prospective, randomized, controlled trial. All patients were recruited and studied in a pediatric emergency department. Forty-three children between the ages of three and 12 years, with a mean age of 8.9 years, presenting with acute asthma were enrolled. Group 1 received Sus-Phrine, 0.005 ml per kg before albuterol aerosols, as appropriate. Group 2 only received albuterol aerosols. There was no significant difference in the extent of improvement between the two groups at either 20 minutes or two hours for clinical score, peak flow, or respiratory rate. Subcutaneous, long-acting epinephrine provides no additional benefit to a beta-2 agonist by nebulization for children with acute asthma.

Sonographic presentation of uterine sex cord-stromal tumor.

A 24-year-old woman presented with continuous vaginal bleeding and anemia. Pelvic sonography demonstrated an enlarged uterus measuring 8.9 x 4.9 x 4.7 cm and a mass within the endometrial cavity measuring 3.0 x 1.8 cm. The mass appeared to be polypoid and echogenic, contained a small cyst, and was suggestive of a polyp. The patient underwent total vaginal hysterectomy. Pathologic examination revealed a uterine sex cord-stromal tumor. To our knowledge, the sonographic features of uterine sex cord-stromal tumor have not been previously reported. The sonographic appearance mimicked that of a polyp.