Influence of TiO2 nanoparticles content as reinforce material to enhance the mechanical and corrosion resistance properties of Sn and Sn-Ag alloy for dental applications.

This study evaluated the influence of the TiO2 nanoparticles (NPs) on the mechanical and chemical performance of Sn and Sn-Ag alloys. The XRD (X-ray diffraction) and HR-TEM (high resolution-transmission electron microscopy) methods were used to characterize the NPs synthesized by the sol-gel microwave process. The chemical composition of the alloys was Sn, Sn+3TiO2 NPs, Sn-5Ag+1.5TiO2 NPs, Sn-10Ag, and Sn-10Ag+3TiO2 NPs, obtained from an experimental factorial design (EFD). A statistical model was used to determine the mechanical and chemical properties, showing the Vickers hardness response surface, tensile strength, wear, and corrosion resistance. The wear and corrosion tests for the various alloy compositions were performed using human artificial saliva solution. The results indicated that the Sn-10Ag+3TiO2 NPs exhibited the highest mechanical performance due to their increased hardness (380 HV), tensile strength (370 N), and wear resistance (0.34 × 10-3 mm3 Nm-1); in all the cases, the inclusion of TiO2 NPs enhanced the corrosion resistance of the alloys. According to the American Dental Association (ADA), Sn-10Ag+3TiO2 NPs alloy could be classified as a possible type IV restorative material.

Characteristics of Medically Transported Critically Ill Children with Respiratory Failure in Latin America: Implications for Outcomes.

Several challenges exist for referral and transport of critically ill children in resource-limited regions such as Latin America; however, little is known about factors associated with clinical outcomes. Thus, we aimed to describe the characteristics of critically ill children in Latin America transferred to pediatric intensive care units for acute respiratory failure to identify risk factors for mortality. We analyzed data from 2,692 patients admitted to 28 centers in the Pediatric Collaborative Network of Latin America Acute Respiratory Failure Registry. Among patients referred from another facility (773, 28%), nonurban transports were independently associated with mortality (adjusted odds ratio = 9.4; 95% confidence interval: 2.4-36.3).

Is there association between human development index and tuberculosis mortality risk? Evidence from a spatial analysis study in the south of Brazil.

The goal of this study was to analyse the spatial pattern of tuberculosis (TB) mortality using different approaches, namely: mortality rates (MR), spatial relative risks (RR) and Bayesian rates (Global and Local) and their association with human development index (HDI), Global and its three dimensions: education, longevity and income. An ecological study was developed in Curitiba, Brazil based on data from Mortality Information System (2008-2014). Spatial scan statistics were used to compute RR and identify high-risk clusters. Bivariate Local Indicator of Spatial Associations was used to assess associations. MR ranged between 0 and 25.24/100.000 with a mean (standard deviation) of 1.07 (2.66). Corresponding values for spatial RR were 0-27.46, 1.2 (2.99) and for Bayesian rates (Global and Local) were 0.49-1.66, 0.90 (0.19) and 0-6.59, 0.98 (0.80). High-risk clusters were identified for all variables, except for HDI-income and Global Bayesian rate. Significant negative spatial relations were found between MR and income; between RR and HDI global, longevity and income; and Bayesian rates with all variables. Some areas presented different patterns: low social development/low risk and high risk/high development. These results demonstrate that social development variables should be considered, in mortality due TB.

Green chemistry synthesis of nano-cuprous oxide.

Green chemistry and a central composite design, to evaluate the effect of reducing agent, temperature and pH of the reaction, were employed to produce controlled cuprous oxide (Cu2O) nanoparticles. Response surface method of the ultraviolet-visible spectroscopy is allowed to determine the most relevant factors for the size distribution of the nanoCu2O. X-ray diffraction reflections correspond to a cubic structure, with sizes from 31.9 to 104.3 nm. High-resolution transmission electron microscopy reveals that the different shapes depend strongly on the conditions of the green synthesis.

[Recurrent pregnancy loss: a literature review]. / Pérdida recurrente del embarazo: revisión bibliográfica.

Background: The definition of recurrent pregnancy loss varies according different authors and consensus: the American Society for Reproductive Medicine (ASRM) defines RPL when two or more pregnancy losses occur, and the European Society of Human Reproduction and Embryology (ESHRE) defines it as three or more pregnancy losses, not necessarily intrauterine. To this day, there is no uniform approach that serves as a guide in the diagnosis and treatment of this condition; this is why, in up to 50% of the cases of RPL, it will not be possible to identify the specific etiology. Objetive: To report on the recurrent pregnancy loss, in order to harmonize concepts and suggest a diagnosis and treatment for this condition approach. Method: The search strategy included, but was not limited to keywords like: recurrent abortion, infertility, habitual abortion, primary antiphospholipid syndrome, lupus anticoagulant, anti-cardiolipin antibodies and anti B2 glycoprotein I.

The Use of Recombinant Tissue Plasminogen Activator (rTPA) in The Treatment of Fibrinous Pleuropneumonia in Horses: 25 Cases (2007-2012).

BACKGROUND: Information about treatment protocols, adverse effects and outcomes with intrapleural recombinant tissue plasminogen activator (rTPA) use in horses with fibrinous pleuropneumonia is limited. HYPOTHESIS/OBJECTIVES: Describe factors that contribute to clinical response and survival of horses treated with rTPA intrapleurally. ANIMALS: Horses with bacterial pneumonia and fibrinous pleural effusion diagnosed by ultrasonography, that were treated with rTPA intrapleurally. METHODS: Retrospective multicenter case series from 2007-2012. Signalment, history, clinical and laboratory evaluation, treatment, and outcome obtained from medical records. Regression analysis used to identify associations between treatments and outcomes. RESULTS: Thirty three hemithoraces were treated in 25 horses, with 55 separate treatments. Recombinant tissue plasminogen activator (375-20,000 µg/hemithorax) was administered 1-4 times. Sonographically visible reduction in fibrin mat thickness, loculations, fluid depth, or some combination of these was seen in 32/49 (65%) treatments. Response to at least 1 treatment was seen in 17/20 (85%) horses with sonographic follow-up evaluation after every treatment. Earlier onset of rTPA treatment associated with increased survival odds. No association was found between cumulative rTPA dose or number of rTPA doses and survival, development of complications, duration of hospitalization or total charges. Clinical evidence of hypocoagulability or bleeding was not observed. Eighteen horses (72%) survived to discharge. CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment with rTPA appeared safe and resulted in variable changes in fibrin quantity and organization within the pleural space. Recombinant tissue plasminogen activator could be a useful adjunct to standard treatment of fibrinous pleuropneumonia, but optimal case selection and dosing regimen remain to be elucidated.

Long-term decline of the Amazon carbon sink.

Atmospheric carbon dioxide records indicate that the land surface has acted as a strong global carbon sink over recent decades, with a substantial fraction of this sink probably located in the tropics, particularly in the Amazon. Nevertheless, it is unclear how the terrestrial carbon sink will evolve as climate and atmospheric composition continue to change. Here we analyse the historical evolution of the biomass dynamics of the Amazon rainforest over three decades using a distributed network of 321 plots. While this analysis confirms that Amazon forests have acted as a long-term net biomass sink, we find a long-term decreasing trend of carbon accumulation. Rates of net increase in above-ground biomass declined by one-third during the past decade compared to the 1990s. This is a consequence of growth rate increases levelling off recently, while biomass mortality persistently increased throughout, leading to a shortening of carbon residence times. Potential drivers for the mortality increase include greater climate variability, and feedbacks of faster growth on mortality, resulting in shortened tree longevity. The observed decline of the Amazon sink diverges markedly from the recent increase in terrestrial carbon uptake at the global scale, and is contrary to expectations based on models.

Effect of PM(10) and O(3) on infant mortality among residents in the Mexico City Metropolitan Area: a case-crossover analysis, 1997-2005.

INTRODUCTION: Consistent evidence has shown a positive association between air pollution and daily mortality among adults. Less is known about its effect on infant mortality and the modification of this association by socioeconomic status (SES). OBJECTIVE: To assess the association of particulate matter with an aerodynamic diameter of ≤10µm (PM(10)) and ozone (O(3)) on infant mortality and its modification by SES. METHODS: We evaluated the relationship of 24 h mean PM(10) and 1h daily maximum O(3) levels with 12 079 all-cause deaths (3903 respiratory deaths) among 1- to 11-month-old infants residing in the Mexico City Metropolitan Area between January 1997 and December 2005 using a case-crossover approach. The data were analysed using conditional logistic regression models, controlling for weather conditions and day of the week. RESULTS: Single-effect models showed, for all-cause mortality, increases of 5.5% (95% CI 1% to 10%) at lag1 and 6.6% (2% to 11.4%) at lag2; cumulative exposure models (0-2 days) showed an increase of 6.3% (0.01% to 32.7%). Respiratory mortality increased marginally at 5.3% (-0.02% to 13.2%) with a 1-day lag and 10% (2.1% to 18%) with a 2-day lag per increase of 38.7 µg/m(3) (IQR) in PM(10) levels. When data were stratified by SES (low, medium, and high), only infants with low and medium SES presented a significant increase in risk of all-cause mortality and respiratory mortality in relation to PM(10). O(3) was only significantly related to respiratory mortality in low SES. CONCLUSION: Our results suggest that in the Mexico City Metropolitan Area, infants with lower SES (low to medium) are at higher risk of mortality when exposed to ambient PM(10) and O(3).

Pattern and process in Amazon tree turnover, 1976-2001.

Previous work has shown that tree turnover, tree biomass and large liana densities have increased in mature tropical forest plots in the late twentieth century. These results point to a concerted shift in forest ecological processes that may already be having significant impacts on terrestrial carbon stocks, fluxes and biodiversity. However, the findings have proved controversial, partly because a rather limited number of permanent plots have been monitored for rather short periods. The aim of this paper is to characterize regional-scale patterns of 'tree turnover' (the rate with which trees die and recruit into a population) by using improved datasets now available for Amazonia that span the past 25 years. Specifically, we assess whether concerted changes in turnover are occurring, and if so whether they are general throughout the Amazon or restricted to one region or environmental zone. In addition, we ask whether they are driven by changes in recruitment, mortality or both. We find that: (i) trees 10 cm or more in diameter recruit and die twice as fast on the richer soils of southern and western Amazonia than on the poorer soils of eastern and central Amazonia; (ii) turnover rates have increased throughout Amazonia over the past two decades; (iii) mortality and recruitment rates have both increased significantly in every region and environmental zone, with the exception of mortality in eastern Amazonia; (iv) recruitment rates have consistently exceeded mortality rates; (v) absolute increases in recruitment and mortality rates are greatest in western Amazonian sites; and (vi) mortality appears to be lagging recruitment at regional scales. These spatial patterns and temporal trends are not caused by obvious artefacts in the data or the analyses. The trends cannot be directly driven by a mortality driver (such as increased drought or fragmentation-related death) because the biomass in these forests has simultaneously increased. Our findings therefore indicate that long-acting and widespread environmental changes are stimulating the growth and productivity of Amazon forests.

Infección de prótesis de aorta ascendente: tratamiento con aseo quirúrgico, preservación de prótesis y transposición de colgajo muscular en dos casos / Infection of ascending aortic graft: treatment with surgical cleaning, graft preservation and transposition of muscle flaps, report of 2 cases

Mediastinitis with graft infection is a serious complication of ascending aorta replacement. We report two cases of graft infection, treated with surgical cleaning, graft preservation and transposition of muscle flaps. A 62 years old male was admitted 34 days after an ascending aortic grafting due to a sternal dehiscence and mediastinitis. Antimicrobial treatment was started and a surgical cleaning performed, leaving an open sternotomy. Three days later, the thoracic cavity was closed with a rectus abdominis muscle flap. After 23 months of follow up, the patient is well and without evidence of infection. A 74 years old male was subjected to an aortic valve and ascending aorta replacement and a myocardial revascularization. In the postoperative period, the patient developed septic signs, and a purulent drainage. A CAT scan showed a liquid collection surrounding the aortic graft. On tW Sixteenth postoperative day, a surgical cleaning was performed and the thorax was closed with the pectoralis major muscle. After 10 months of follow up, the patient is in Good condition and without evidence of infection

Aneurisma de la vena poplítea / Popliteal vein aneurysm: report of one case

The popliteal vein aneurysm is a rare condition that can lead to local symptoms, thrombosis and pulmonary embolism. We report the case of a 67 years old, otherwise healthy white male, who presented to us with localised swelling and pain in the left popliteal fossa. Duplex ultrasound and venography were obtained, confirming the diagnosis of popliteal vein aneurysm. The patient underwent tangential aneurysmectomy and lateral venorrhaphy, recovery was uneventful remaining asymptomatic. The reconstruction was demonstrated patent on a duplex scan. The popliteal vein aneurysm is a potentially fatal condition for which surgical treatment is recommended

Protocolo de diagnóstico y tratamiento de la coledocolitiasis en pacientes candidatos a colecistectomía laparoscópica / Protocol of diagnosis and treatment of choledocholithiasis in patients scheduled to laparoscopic cholecystectomy

En la era de la cirugía mínimamente invasiva el manejo de la coledocolitiasis asociada a colelitiasis es aún motivo de controversia. Presentamos a continuación los resultados de un protocolo de manejo de estos pacientes de acuerdo al riesgo estimado de presentar coledocolitiasis asociada a colelitiasis. Se incluyeron en el estudio 605 pacientes candidatos a colecistectomía laparoscópica (CL). De acuerdo a criterios clínicos, bioquímicos y radiológicos se dividió a los pacientes en tres grupos de acuerdo al riesgo de presentar coledocolitiasis. A los pacientes con diagnóstico ecográfico de coledocolitiasis y a aquellos ictéricos al ingreso, se les practicó una CPRE previa a la CL. A aquellos sin sospecha para coledocolitiasis se les estudió mediante colangiografía endovenosa e intraoperatoria. Se analizan los resultados obtenidos en el tratamiento de la coledocolitiasis asociada a colelitiasis mediante la combinación CPRE + CL versus colecistectomía clásica y coledocostomía. Se concluye que el uso juicioso de los criterios para estimar el riesgo de coledocolitiasis ayuda en el uso selectivo de la CPRE y que está combinada con la CL representa una buena alternativa para el tratamiento clásico

Factores de riesgo de coledocolitiasis / Choledocholithiasis risk factors

El tratamiento de la coledocolitiasis asociada a colelitiasis es aún motivo de controversia. La capacidad para predecir la presencia de coledocolitiasis asociada a colelitiasis en pacientes candidatos a cirugía permite dirigir el manejo en forma selectiva. Con este objetivo se analizaron las fichas clínicas de 1137 pacientes sometidos a colecistectomía laparoscópica entre enero de 1993 y abril de 1994, seleccionando 681 pacientes con estudio colangiográfico. Se analizaron parámetros clínicos como ictericia y coluria, bioquímicos como elevación de fosfatasas alcalinas y bilirrubina total y dilatación de la vía biliar en la ecografía. Las variables se analizaron en forma individual (chi cuadrado) y en conjunto (regresión logística paso a paso). En el análisis univariado los parámetros con mejor correlación fueron la ictericia al ingreso, la elevación de fosfatasas alcalinas y la dilatación de la vía biliar. La combinación de las tres arrojó una concordancia del 72 por ciento

Colecistectomía laparoscópica en menores de 15 años de edad / Laparoscopic cholecystectomy in patients under 15 years old

La colecistectomia laparoscópica es hoy el tratamiento de elección en el tratamiento quirúrgico de la colelitiasis. Esta patología es poco frecuente en niños. De un total de 1205 pacientes operados en el período mayo de 1994 hasta mayo 1996, 10 eran menores de 15 años. Edad promedio de 9,9 años; 4 de sexo masculino y 6 de sexo femenino. El motivo de consulta fue dolor abdominal en todos los casos, 2 pacientes se presentaron como colecistitis aguda y se intervinieron de urgencia, el resto en forma electiva. Todos se operaron usando técnica francesa. Se realizó colangiografía intraoperatoria en 2 pacientes. Su evolución postoperatoria fue satisfactoria en todos los casos. No hubo complicaciones. El alta fue a los 1,9 dias en promedio y se reintegraron a sus actividades normales precozmente luego del alta

Ventilación mecánica no invasiva intermitente: utilidad en el tratamiento de la insuficiencia cardíaca crónica avanzada / Non invasive intermittent mechanical ventilation: utility in the treatment of advanced chronic cardiac failure

The higher respiratory work and less inspiratory muscle strength of patients with cardiac failure may contribute to dicrease their functional capacity. To assess the effects of non invasive intermittent mechanical ventilation on clinical parameters, peropheral perfusion, cardiac and inspiratory muscle function. Patients with chronic cardiac failure, functional cpacity III-IV were subjected to 6 sessions of nasal non invasive intermittent ventilation during 4 hours or to simulated ventilation (controls). Fifteen ventilated patients and 6 controls completed the protocol. Ventilated patients improved the mahler transition score for dysnea by 4ñ1.6 points. They also improved their aerobic capacity, increasing the exercise duration from 10.9ñ4 to 12.7ñ5 min and their maximal oxygen consumption from 14.6ñ4 to 16.4ñ5.7 ml/kg/min. These patients also decreased their O2 and CO2 ventilatory equivalents. Maximal inspiratory pressure increased from 67.9ñ23.6 to 80.19ñ21.4 cm H2O, sustained maximal inspiratory pressure increased from 101.4ñ48 to 133ñ53 cm H2O and maximal endurance increased from 132ñ52 to 162ñ58 g in ventilated patients. None of these variables was modified in control patients. No changes were observed in renal function, blood volume, arterial gases, spirometry or plasma catecholamine levels in any group. Intermittent nasal ventilation or other measures to improve inspiratory muscle function may be beneficial for patients with severe cardiac failure

Estudio de las características de flujo en tres tipos de prótesis valvulares cardiacas / Study of the characteristics of the flow in three types of cardiac valvular prosthesis

La turbulencia causada por el flujo transvalvular después de la implantación de una prótesis valvular, es una causa de la formación de trombos en la región postvalvular. La revisión de la literatura al respecto indica que hay mayor frecuencia de accidentes tromboembólicos en las válvulas cardiacas mecánicas de disco oscilante. Con el objeto de determinar la turbulencia que provoca una bioprótesis valvular porcina, una mecánica de esfera Biomed y un equipo para visualizar y fotografiar las características de flujo en las tres válvulas, destinado a visualizar la turbulencia. Se construyó también un equipo accesorio para medir la presión estática y dinámica en varios puntos de la probeta que contiene la prótesis, donde los cambios de presión muestran la turbulencia. Los datos obtenidos en unas 500 tomas de presión se analizaron en una computadora. Estos datos indican que la válvula biológica porcina origina poca turbulencia, en tanto que las mecánicas la provocan en mayor grado. De las mecánicas, la de disco oscilante causa una turbulencia considerablemente mayor que la de esfera y sobre todo, en la vecindad del orificio menor(au)

[Flow characteristics in 3 kinds of heart valve prosthesis]. / Estudio de las características de flujo en tres tipos de prótesis valvulares cardíacas.

Transvalvular turbulence caused by the blood flow in implanted cardiac valvular prosthesis is the cause of thrombosis at the post-valvular region. The literature in this connection indicates that thromboembolic complications are more common with the tilting disc mechanical valves. In order to study the turbulence caused by porcine biological prosthetic valves, by a caged-ball Biomed mechanical valve and by a tilting disc Björk-Shiley valve, a device was developed which permits to visualize and to photograph flow characteristics in the three types of valves with the purpose of determining the degree of turbulence generated in each case. An additional accessory equipment was devised for the purpose of measuring static and dynamic pressures at various levels of the test tube containing the prosthetic valve wherein the variations in pressure reflect the degree of turbulence. The data obtained from 500 pressure registrations were analyzed in a computer. The data indicate that the porcine biological valve causes the least turbulence, whereas the mechanical valves create greater turbulence. Of the mechanical valves, the tilting disc prosthetic valve causes considerably greater turbulence, in particular in the vicinity of the smaller orifice.

[Cardiology in rural areas]. / Cardiología en la ruralia.

Based on a personal experience after having established a cardiology clinic in the town of Arroyo (Puerto Rico), we analyzed the patient population served and the services that were rendered. After collecting the data from the clinical files, we were able to obtain information on diagnosis, follow-up, diagnostic test and therapeutic procedures performed. In general, it was found that only a minority of patients needed long term cardiology follow-up and specialized diagnostic or therapeutic interventions. In conclusion we established that the presence of a cardiology clinic in the rural areas is reasonable, if their function remains as merely consultative.