Gas tungsten arc welding of NiTi shape memory alloy

Shape memory alloys are characterized by the ability of recovering their initial shape after being deformed and by superelasticity. Since the discovery of these alloys, a new field of interest emerged not only for the scientific community but also to many industries. However, these alloys present poor machinability which constitute a constrain in the design of complex components for new applications. Thus, the demand for joining techniques able to join these alloys without compromising their properties became of great importance to enlarge the complexity of existing applications. Literature shows that these alloys are joined mainly using laser welding. In the present study, similar NiTi butt joints, were produced using TIG welding. The welds were performed in 1.5 mm thick plates across the rolling direction. A special fixture and gas assist device was designed and manufactured. Also a robot arm was adapted to accommodate the welding torch to assure the repeatability of the welding parameters. Welds were successfully achieved without macroscopic defects, such as pores and distortions. Very superficial oxidation was seen on the top surface due to insufficient shielding gas flow on the weld face. The welded joints were mechanically tested and structurally characterized. Testing methods were used to evaluate macro and microstructure, as well as the phase transformation temperatures, the mechanical single and cyclic behaviour and the shape recovery ability. Differential Scanning Calorimetry (DSC), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), microhardness measurements were techniques also used to evaluate the welded joints. A depletion in Ni in the fusion zone was seen, as well as a shift in Ms temperature. For strain values of 4% the accumulated irrecoverable strain was of about 30% and increased with the strain imposed during cycling. Nevertheless, a complete recovery of initial shape was observed when testing the shape memory effect on a dedicated device that introduces a deformation of 6.7%. That is, the welding procedure does not remove the ability of the specimens to recover their initial shape.

Acute meningoencephalomyelitis due to varicella-zoster virus in an AIDS patient: report of a case and review of the literature

Varicella-zoster virus (VZV) meningoencephalomyelitis is a rare but severe neurological complication of VZV reactivation in immunocompromised patients. We report the case of an HIV-infected individual who developed an acute and severe meningoencephalomyelitis accompanied by a disseminated cutaneous eruption due to VZV. The presence of VZV DNA in cerebrospinal fluid was confirmed by polymerase chain reaction (PCR) technique. The patient started undergoing an intravenous acyclovir therapy with a mild recovery of neurological manifestations. Varicella-zoster virus should be included as a cause of acute meningoencephalomyelitis in patients with AIDS. Early diagnosis followed by specific therapy should modify the rapid and fulminant course for this kind of patients.

Surgical treatment of type I neuritis in a teenage boy with borderline tuberculoid leprosy

Exacerbation of the immune response against Mycobacterium leprae can lead to neuritis, which is commonly treated via immunosuppression with corticosteroids. Early neurolysis may be performed concurrently, especially in young patients with a risk of functional sequelae. We report the case of a young patient experienced intense pain in the left elbow one year after the treatment of tuberculoid-tuberculoid leprosy. The pain was associated with paresthesias in the ulnar edge and left ulnar claw. After evaluation, the diagnosis was changed to borderline tuberculoid leprosy accompanied with neuritis of the left ulnar nerve. Early neurolysis resulted in rapid reduction of the pain and recovery of motor function.

Implementation of membrane processes for improvement of the detection of food contaminants

The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centres and universities (http://www.em3e.eu)

The effect of the presence of muscle tissue in a bone healing site

PURPOSE: The recovery of a bone fracture is a process that is not yet fully understood. The literature conflicts on the results obtained by the interposition of foreign tissue inside a damaged bone. The objective of the present study was to ascertain the effect of placing muscle tissue between the stumps of a fractured bone. METHOD: The study was carried out on 10 rabbits divided into 2 groups (n = 5): Group 1-partial fracture of the humerus and interposition of muscle tissue; Group 2-complete fracture of the humerus and interposition of muscle tissue. The fractured limb of all animals was immobilized for 8 weeks. At the end of this time, the rabbits were killed and their operated humeri were carefully removed for roentgenological and histological assessment. RESULTS: All humeri of Group 1 recovered their integrity and normal aspect. However, the healing of the humeri of Group 2 was not perfect. Gross angulation of the bone diaphysis occurred in all animals, and immature trabecular bone, osteochondral tissue, and persistence of muscle tissue substituted normal bone. CONCLUSIONS: Interposed muscle does not affect partial bone fracture healing but causes instability in a complete fracture.

Modification of microfiltration membranes by hydrogel impregnation for pDNA purification

The huge efforts for the achievement of highly purified biomolecules are growing every day. A great number of efficient techniques, such as chromatography, are already available in laboratory for separation processes. However, membrane-based technologies are the best match to assure simplicity, efficiency and easy scale-up procedures. Herein we report the modification of a commercial microfiltration membrane for plasmid DNA purification by agarose gel impregnation. The membrane was characterized by SEM, ATR-FTIR, EDS, contact angle, and porosity measurements. Additionally, the membrane pore radius was estimated from observed rejections of different proteins and with that information the rejection of a 6050 bp plasmid DNA (pDNA) molecule was estimated for different values of flux using a theoretical model of large flexible molecules in membranes with parallel cylindrical pores, which is applicable to pDNA ultrafiltration in conventional membranes, as recently shown in the literature. The experimental results show that the modified membrane has higher pDNA rejections than the predicted by the model, suggesting that the different type of porous structure that a hydrogel has, may have a positive effect on pDNA rejections as compared to other biomolecules with more rigid structures, making this type of modified membranes potential better candidates to be used for the selective recovery of pDNA in this type of bioprocesses.

A structured inventory of spiders (Arachnida, Araneae) in natural and artificial forest gaps at Porto Urucu, Western Brazilian Amazonia

A preliminary survey of the spider fauna in natural and artificial forest gap formations at “Porto Urucu”, a petroleum/natural gas production facility in the Urucu river basin, Coari, Amazonas, Brazil is presented. Sampling was conducted both occasionally and using a protocol composed of a suite of techniques: beating trays (32 samples), nocturnal manual samplings (48), sweeping nets (16), Winkler extractors (24), and pitfall traps (120). A total of 4201 spiders, belonging to 43 families and 393 morphospecies, were collected during the dry season, in July, 2003. Excluding the occasional samples, the observed richness was 357 species. In a performance test of seven species richness estimators, the Incidence Based Coverage Estimator (ICE) was the best fit estimator, with 639 estimated species. To evaluate differences in species richness associated with natural and artificial gaps, samples from between the center of the gaps up to 300 meters inside the adjacent forest matrix were compared through the inspection of the confidence intervals of individual-based rarefaction curves for each treatment. The observed species richness was significantly higher in natural gaps combined with adjacent forest than in the artificial gaps combined with adjacent forest. Moreover, a community similarity analysis between the fauna collected under both treatments demonstrated that there were considerable differences in species composition. The significantly higher abundance of Lycosidae in artificial gap forest is explained by the presence of herbaceous vegetation in the gaps themselves. Ctenidae was significantly more abundant in the natural gap forest, probable due to the increase of shelter availability provided by the fallen trees in the gaps themselves. Both families are identified as potential indicators of environmental change related to the establishment or recovery of artificial gaps in the study area.

Protected environments and substrates for production of genipap seedlings

Genipap (Genipa americana L., Rubiaceae ) is a native Brazilian species and can be used in the recovery of degraded forest areas or for food supply. In order for the species to reach its potential, production of high quality seedlings is essential. The objective of this study was to evaluate genipap seedlings in protected environments and different substrates. The environments tested were: (1) a greenhouse with polyethylene film in the top, with aluminized screen (Aliminet®) of 50%-shading under this film, and lateral sides covered with 50%-shading nylon net (Sombrite®), (2) a shaded hut, all sides covered with 50%-shading nylon net (Sombrite®), and (3) a nursery shelter, with all lateral sides uncovered and the roof covered with leaves of buriti (Mauritia flexuosa). In these environments the following substrates were tested: 50% cattle manure + 50% cassava foliage, 50% cattle manure + 50% Vida Verde®, 50% cattle manure + 50% vermiculite, and 25% cattle manure + 25% vermiculite + 25% of cassava foliage + 25% Vida Verde®. Because there was no repetition of the growth environment, the effect of environment was examined using statistical procedures for analysis of combined experiments. Within environments a completely randomized design was used with five replications. All substrates are suitable for the formation of genipap seedlings, where the recommended substrates are: 50% cattle manure + 50% cassava foliage and 50% cattle manure + 50% Vida Verde® for the greenhouse and the substrates composed of 50% cattle manure + 50% vermiculite and 25% cattle manure + 25% cassava foliage + 25% Vida Verde®+ 25% vermiculite for the shaded hut. The buriti shelter is not recommended for production of genipap seedlings.

Floristic and structure of an Amazonian primary forest and a chronosequence of secondary succession

ABSTRACT The analysis of changes in species composition and vegetation structure in chronosequences improves knowledge on the regeneration patterns following land abandonment in the Amazon. Here, the objective was to perform floristic-structural analysis in mature forests (with/without timber exploitation) and secondary successions (initial, intermediate and advanced vegetation regrowth) in the Tapajós region. The regrowth age and plot locations were determined using Landsat-5/Thematic Mapper images (1984-2012). For floristic analysis, we determined the sample sufficiency and the Shannon-Weaver (H'), Pielou evenness (J), Value of Importance (VI) and Fisher's alpha (α) indices. We applied the Non-metric Multidimensional Scaling (NMDS) for similarity ordination. For structural analysis, the diameter at the breast height (DBH), total tree height (Ht), basal area (BA) and the aboveground biomass (AGB) were obtained. We inspected the differences in floristic-structural attributes using Tukey and Kolmogorov-Smirnov tests. The results showed an increase in the H', J and α indices from initial regrowth to mature forests of the order of 47%, 33% and 91%, respectively. The advanced regrowth had more species in common with the intermediate stage than with the mature forest. Statistically significant differences between initial and intermediate stages (p<0.05) were observed for DBH, BA and Ht. The recovery of carbon stocks showed an AGB variation from 14.97 t ha-1 (initial regrowth) to 321.47 t ha-1 (mature forests). In addition to AGB, Ht was also important to discriminate the typologies.

Development of procedures for the design, optimization and manufacturing of customized orthopaedic and trauma implants: Geometrical/anatomical modelling from 3D medical imaging

Tese de Doutoramento (Programa Doutoral em Engenharia Biomédica)

Natural course of subsequent pregnancy after peripartum cardiomyopathy

OBJECTIVE: To assess the effect of subsequent pregnancy after peripartum cardiomyopathy (PPCM) on maternal and fetal outcome. METHODS: Prospective study of 34 patients with the diagnosis of PPCM (mean age= 26years). At the time of first diagnosis 5 were in NYHA functional class (FC) II for heart failure, one in FC III and 28 in FC IV. After clinical treatment, patients were advised to avoid new pregnancies and a follow-up was obtained. RESULTS: There were 12 (35.3%) subsequent pregnancies in patients (pt) aged 19 to 44 years (mean 32), divided into two groups: GI: 6 pts who had normalized their heart size and GII: 6 pts with persistent cardiomegaly. GI had initially mild clinical manifestations ( 3 were in FC II, 1 in FC II and 2 in FC IV) and complete recovery of cardiac function (FC I). A new pregnancy was well-tolerated in 5 (83.3%); 1 pt presented with preeclampsia, and progressed to FC II. Presently, 5 pt are in FC I and 1 in FC II. GII pts had more severe heart failure at the onset of PPCM (1 pt in FC II and 5 in FC IV); during follow-up, 4 pt were in FC I and 2 in FC II. A new pregnancy was well tolerated in all of them, but the eldest, who had had 2 pregnancies and had a progressive worsening of clinical status, dying 8 years after the last pregnancy and 13 years after the diagnosis of PPCM. The remaining 5 pt are still alive, 3 in FC I and 2 in FC II, with worsening of FC in 1. Subsequent pregnancies occurred 3-7 years after clinical treatment of PPCM and no fetal distress was observed. CONCLUSION: Subsequent pregnancies are well-tolerated after PPCM, but not devoid of risk. No fetal distress was observed. A minimum interval of 3 years after the recovery of function seems to be safe for subsequent pregnancies.

Oxygen therapy, continuous positive airway pressure, or noninvasive bilevel positive pressure ventilation in the treatment of acute cardiogenic pulmonary edema

OBJECTIVE: To compare the effects of 3 types of noninvasive respiratory support systems in the treatment of acute pulmonary edema: oxygen therapy (O2), continuous positive airway pressure, and bilevel positive pressure ventilation. METHODS: We studied prospectively 26 patients with acute pulmonary edema, who were randomized into 1 of 3 types of respiratory support groups. Age was 69±7 years. Ten patients were treated with oxygen, 9 with continuous positive airway pressure, and 7 with noninvasive bilevel positive pressure ventilation. All patients received medicamentous therapy according to the Advanced Cardiac Life Support protocol. Our primary aim was to assess the need for orotracheal intubation. We also assessed the following: heart and respiration rates, blood pressure, PaO2, PaCO2, and pH at begining, and at 10 and 60 minutes after starting the protocol. RESULTS: At 10 minutes, the patients in the bilevel positive pressure ventilation group had the highest PaO2 and the lowest respiration rates; the patients in the O2 group had the highest PaCO2 and the lowest pH (p<0.05). Four patients in the O2 group, 3 patients in the continuous positive pressure group, and none in the bilevel positive pressure ventilation group were intubated (p<0.05). CONCLUSION: Noninvasive bilevel positive pressure ventilation was effective in the treatment of acute cardiogenic pulmonary edema, accelerated the recovery of vital signs and blood gas data, and avoided intubation.

Use of automated external defibrillators in a Brazilian airline. A 1-year experience

After the incorporation of automated external defibrilators by other airlines and the support of the Brazilian Society of cardiology, Varig Airlines Began the onboard defibrilation program with the initial purpose of equiping wide-body aircrafts frequently used in international flights and that airplanes use in the Rio - São Paulo route. With all fight attendants trained, the automated. External defibrilation devides were incorporated to 34 airplanes of a total pleet of 80 aircrats. The devices were intalled in the bagage compartments secured with velero straps and 2 pairs of electrods, one or which pre-conected to the device to minimize application time. Later, a portable monitor was addres to the ressocitation kit in the long flights. The expansion of the knowledge of the basic life support fundamentors and the correted implantation of the survival chain and of the automated external defibrilators will increase the extense of recovery of cardiorespiratory arrest victins in aircrafts.

Anomalous origin of the left coronary artery from the pulmonary trunk in a 45-year-old woman

We report a rare case of anomalous origin of the left coronary artery from the pulmonary trunk in a 45-year-old woman. The approach and technique used for selective catheterization of an anomalous left coronary artery arising from the pulmonary trunk are described. Six years after diagnosis, echocardiography showed left ventricular disfunction, and surgical treatment was indicated again. The origin of the left coronary artery from the pulmonary trunk was closed, and the postoperative period was uneventful, with recovery of left ventricular function and disappearance of ischemic features on stress myocardial perfusion imaging with 99m Tc-sestamibi, performed 4 weeks after surgery.

Enfermedad de Chagas: epidemiología de vectores y estrategias educativas para la vigilancia entomológica en áreas de riesgo del norte de la provincia de Córdoba. Chagas disease: epidemiology of vectors and educational strategies for entomological surveillance in risk areas of northern province of Cordoba.

La Enfermedad de Chagas es considerada en términos sociales y económicos, una de las enfermedades parasíticas más importantes de América Latina. La transmisión vectorial de esta enfermedad ha sido interrumpida en gran parte de América Latina sin embargo, el control vectorial no ha podido lograr la sostenibilidad y la efectividad necesarias para interrumpir la transmisión vectorial en la región del Gran Chaco de Argentina, Bolivia y Paraguay. La permanencia de poblaciones residuales de triatominos en estructuras peridomiciliarias permite una rápida recuperación del vector, sugiriéndose que estas poblaciones serían la principal fuente de reinfestación de la vivienda humana. Este escenario plantea por lo tanto la necesidad de estudiar con más profundidad las poblaciones de triatominos presentes en los peridomicilios para comprender su dispersión, capacidad de domiciliación y así entender el posible peligro que pueden presentar para el hombre como especies vectoras de la enfermedad de Chagas. Dentro de la provincia de Córdoba existen áreas que por la presencia histórica de triatomineos, la notificación reciente de casos de Chagas vectorial y el registro de especies silvestres invadiendo los domicilios merecen un estudio más profundo. Es por ello que se propone realizar un relevamiento de las especies de triatomineos que habitan los domicilios y peridomicilios en estas zonas, calcular los índices de infección con Trypanosoma cruzi que presentan, caracterizar su perfil alimentario, los factores de riesgo que favorecen su refugio, su capacidad dispersiva y diferenciar fenotípicamente entre las poblaciones peridomésticas para comprender mejor el posible peligro que pueden presentar para el hombre como especies vectoras de la enfermedad de Chagas. Además, y de manera complementaria, se aplicarán estrategias educativas en el ámbito escolar que sirvan para la vigilancia entomológica y acciones preventivas de la Enfermedad de Chagas. La determinación del perfil alimentario pautará la potencialidad de cada vector, siendo esta información fundamental para el análisis de situaciones epidemiológicas de riesgo. La capacidad dispersiva y la diferenciación fenotípica de las poblaciones permitirán conocer el posible movimiento y flujo de triatominos desde y hacia la vivienda humana. La determinación de los factores que favorecen el refugio de triatominos permitirá conocer el nivel de riesgo en que se encuentra cada domicilio. Además, considerando la importancia de las poblaciones peridomésticas en los procesos de reinfestación, se analizará la capacidad dispersiva que presentan los triatominos a través de su estado nutricional y, mediante la morfometría clásica y geométrica, se analizará como se estructura la diversidad fenotípica en los domicilios y peridomicilios. La aplicación de estrategias educativas en el ámbito escolar favorecerá el conocimiento en general de esta enfermedad, la vigilancia entomólogica y las acciones preventivas por parte de los niños en edad escolar. Chagas disease is considered socially and economically, one of the most important parasitic diseases in Latin America. Vector transmission of this disease has been interrupted in much of Latin America, however, vector control has failed to achieve sustainability and effectiveness necessary to interrupt the vector transmission in the Gran Chaco region of Argentina, Bolivia and Paraguay. The permanence of residual populations of triatomine in the peridomiciliary structures enables fast recovery of the vector, suggesting that these populations would be the main source of reinfestation of human dwellings. Within the province of Córdoba, there are areas that the historical presence of triatomines, the recent notification of cases of Chagas vector and recording of wild species invading the homes deserve further study. That is why, there will be a survey of Triatominae species that inhabit the domiciles and peridomiciles in these areas, rates of infection with Trypanosoma cruzi, their host feeding preferences, the risk factors that favor its shelter, their dispersive capacity and phenotypic differentiation between peridomestic populations, to better understand the potential danger they may present to the man and vector species of Chagas disease. In addition, complementary, educational strategies in schools were implemented that serve for entomological surveillance and preventive actions of Chagas disease. The determination of the potential food profile patterns of each vector is essential for epidemiological analysis of risk situations. Dispersive capacity and phenotypic differentiation of populations may allow understanding the movement and flow of triatomines and from human habitation.