2,655 research outputs found
Langerhans Cell Histiocytosis in the Occipital Condyle: A Case Study and a Brief Review of the Literature
We present a case study of a 5-year-old patient, who presented with left-sided torticollis. Due to persistence of problems, a CT and an MRI were made showing a single osteolytic lesion centred on right occipital condyle. After an open biopsy, histology confirmed it to be Langerhans cell histiocytosis (LCH). Torticollis or restricted range of motion is a presenting feature in 76% of children with LCH with cervical involvement. There remains much debate on the best treatment strategy. The clinical and radiological outcomes of the case study presented on this article support the treatment of LCH with chemotherapy in cases with solitary involvement of the occipital condyle.info:eu-repo/semantics/publishedVersio
Paresia do Membro Superior Contralateral ApĂłs Infiltração de Toxina BotulĂnica A para Espasticidade PĂłs-AVC
Botulinum toxin type A has been approved for spasticity management in poststroke patients. The adverse effects are generally of two types: those related to local injection; and those related to the systemic effects from spread of the toxin. Contralateral weakness after botulinum toxin A treatment is a rarely reported adverse effect. We report the case of a 33-year-old female who had been receiving regular injections of incobotulinum toxin A due to spasticity of the right limbs after a hemorrhagic stroke. A switch was made to abobotulinum toxin A with an overall conversion ratio of 1:3.83. The patient presented contralateral upper limb paresis, especially of the deltoid muscle, in the second week post-injection. The electroneuromyography showed neuromuscular block due to botulinum toxin A. She recovered completely after eight months. A switch between different formulations of botulinum toxin type A should prompt caution when carrying out unit conversions. Distant side effects may appear, including paresis in the contralateral limbs.info:eu-repo/semantics/publishedVersio
The production of TiAl by foundry processes
This paper describes a foundry technique that enables the production of TiAl employing an
adapted melting procedure that uses an induction furnace with suitable refractory crucibles, inside
a controlled atmosphere chamber. The developed technique allows the production of samples with
a low and controlled amount of residual elements, with a thin superficial hard skin – known as
“alpha-case” – and allows the use of higher superheating temperatures, when compared with
alternative melting procedures.
The micro-hardness and the residual contamination profiles, from the outside to the interior of
samples, are presented and correlated to crucible refractory material and foundry practice.(undefined
Processing of titanium aluminides by ceramic crucible induction melting
This work describes the processing results of TiAl alloys melted in controlled atmosphere induction furnace, using crucibles made of calcia and zirconia stabilised with yttria, calcia and magnesia, solidified and inside the crucible, in order to simulate the worst situation using this processing. In the results are presented segregation profiles of residual elements and its relation with micro hardness and “alpha-case” extension, in the microconstituents present at room temperatur
INJECTABLE HYBRID SYSTEM FOR STRONTIUM LOCAL DELIVERY TO PROMOTE BONE REGENERATION
In bone tissue regeneration strategies, injectable bone substitutes are very attractive since they can
be applied with minimally invasive surgical procedures and can perfectly fill irregular defects created
in cases of trauma, infection or tumor resection. These materials must combine adequate mechanical
properties with the ability to induce new bone formation. Incorporating strontium (Sr) in bone
substitute biomaterials may be a strategy to achieve high Sr concentrations, not in a systemic but in
a local environment, taking advantage of the osteoanabolic and anti-osteoclastic activity of Sr, for
the enhancement of new bone formation. In this context, the aim of the present work was to
evaluate the response of a Sr-hybrid injectable system for bone regeneration, designed by our
group, consisting of hydroxyapatite microspheres doped with Sr and an alginate vehicle crosslinked in
situ with Sr, in an in vivo scenario. Two different animal models were used, rat (Wistar) and sheep
(Merino Branco) critical sized bone defect. Non Sr-doped similar materials (Ca-hybrid) or empty
defects were used as control. Sr-hybrid system led to an increased bone formation in both center
and periphery of a rat critical sized defect compared to a non Sr–doped similar system, where new
bone formation was restricted to the periphery. Moreover newly formed bone was identified as early
as one week after its implantation in a sheep model. After eight weeks, the bone surrounded the
microspheres, both in the periphery and in the center of the defect. Most importantly, the hybrid
system provided a scaffold for cell migration and tissue ingrowth and offered structural support, as
observed in both models. The effective improvement of local bone formation suggests that this might
be a promising approach for bone regeneration, especially in osteoporotic conditions
Use of acoustic energy in the processing of molten aluminium alloys
During the last years aluminium alloys have been gaining increased acceptance as structural materials in the automotive and aeronautical industries, mainly due to their light weight, good formability and corrosion resistance. However, improvement of mechanical properties is a constant in research activities, either by the development of new alloys or by microstructure manipulation.
This presentation focuses a novel effective dynamic methodology to perform microstructural refinement / modification and degassing of light alloys, namely aluminium alloys, by applying acoustic energy to the melts.
High intensity acoustic energy significantly improves the microstructure, therefore the mechanical properties of those alloys, avoiding the use of traditional chemically based degassing and refining techniques which are less effective and present significant environmental impact. Ultrasonic (US) vibration has proven to be extremely effective in degassing, controlling columnar dendritic structure, reducing the size of equiaxed grains and, under some conditions, producing globular grains and modifying the eutectic silicon cells in Al-Si alloys. The mechanisms of US processing of aluminium melts are discussed and experimental results on this field are presented.Fundação para a Ciência e Tecnologia (FCT
Effect of physical exercise on lipid metabolism in the elderly
PURPOSE: To assess the effect of regular physical exercise on plasma lipids and apoproteins in an elderly group.
MATERIAL AND METHODS: Sixty-three old people of both sexes, aged between 65 and 94, were randomly distributed between a test group (n = 31) and a control group (n = 32). The test group followed a program of physical exercise for eight months, with intensity of 60% to 80% of heart rate reserve, consisting of three weekly sessions, on alternate days, of 60 minutes each. Before the beginning of the program and eight months afterwards, blood samples were collected to assess total cholesterol, triglycerides, HDL-C, HDL2-C. HDL3-C, apo A1, apo B-100 and apo (a). The ratios total cholesterol/HDL-C, LDL-C/HDL-C, HDL2-C/HDL3-C and apo A1/apo B-100 were also calculated.
RESULTS: In the test group total cholesterol, triglycerides, LDL-C, apo B-100, total cholesterol/HDL-C and LDL-C/HDL-C decreased significantly; HDL-C, HDL2-C, apo A1, HDL2-C/HDL3-C and apo A1/apo B-100 increased significantly; HDL3-C and apo (a) did not change. The control group did not present any significant alterations in any of the parameters assessed.
CONCLUSIONS: Regular physical exercise decreases vascular risk and may help to reduce cardiovascular events in the elderly
Avaliação das variações no tempo de relaxação da água em bananas durante o amadurecimento.
bitstream/CNPDIA-2010/12619/1/CiT47-2009.pd
Mobile robot for autonomous golf balls picking
This paper describes a robot to collect golf balls in a driving range, operating as autonomous and/or remotely operated. It uses a set of sensors which gives the robot capacities of surrounding environment perception and digital image processing to search for the balls in places with higher concentrations of balls. This system avoids stopping the players for ball collection permitting a higher use rate of the field
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