Image of pseudocapture caused by micro-dislodgment of the electrode in a VDD pacemaker

The new AV sequential pacemakers have improved the suitability for the election of the best pacing mode for each patient. The complexity of the systems may mask some dysfunctions. In the presented case, a failure to capture due to micro-dislodgment, may have been missed in a simple pacemaker control, because of the combination of several factors: the presence of normal AV conduction at that moment, the concordance between the pacemaker stimulus and the conducted QRS complex and the similar morphology of the conducted and paced QRS complex.     

Pyomyositis and AIDS

After more than a decade of special treatment, HIV medicine is ready to enter the mainstream of medical practice in developed countries. Access to a conveniently located, well informed, primary care doctor who works well with an appropriate specialist is the cornerstone of best medical care for chronic illness, including HIV disease. Managing HIV is part of the second phase of a national educational program aimed at equipping more doctors with the skills to care for people with HIV.     

A hominid from the lower Pleistocene of Atapuerca, Spain: possible ancestor to Neandertals and modern humans

Human fossil remains recovered from the TD6 level (Aurora stratum) of the lower Pleistocene cave site of Gran Dolina, Sierra de Atapuerca, Spain, exhibit a unique combination of cranial, mandibular, and dental traits and are suggested as a new species of Homo-H. antecessor sp. nov. The fully modern midfacial morphology of the fossils antedates other evidence of this feature by about 650, 000 years. The midfacial and subnasal morphology of modern humans may be a retention of a juvenile pattern that was not yet present in H. ergaster. Homo antecessor may represent the last common ancestor for Neandertals and modern humans.     

The production of monoenergetic fast neutrons of known flux: An improved method to identify the associated particle

The performance of a deuterium gas target to produce neutrons from the D(d, n)³He reaction is reported. The associated particle method is used. The associated particle is unequivocally identified with a telescope employing microchannel-plate electron multipliers and a silicon surface barrier detector, providing both time-of-flight (TOF) and energy (E) information. The system was set up at the 7 MV Van de Graaff CN accelerator of the laboratori Nazionali di Legnaro (Padova), and has been tested with deuteron energies from 2.5 to 6.5 MeV. About 300 tagged neutrons per s sr nA atm are produced. The TOF-E identification method to discriminate the associated particle will be used in the future in measurements at higher deuteron energies and with the reaction T(d, n)⁴He.     

Limits of pulmonary resection

Foreign body aspiration in children may present with a variety of symptoms. We report here an unusual case of laryngeal foreign body in an infant masquerading as laryngeal web in its clinical presentation as well as radiological findings. The diagnosis was only made at endoscopy, thus emphasising the limited sensitivity of radiographic studies in identifying this condition.     

LASER-DRILLING APPLICATION TO A CERAMIC-COATED ALLOY

The capability of laser drilling applied to various materials is first outlined. The article then focuses on the study of material removal by the laser beam which influences the quality of the hole since “recast”, i.e. resolidified material, often exhibits microcracking, modifies the shape and more generally the properties of the hole due to a sort of coating of the hole inner wall.

A fluid-mechanics approach to describe the removal phenomena is proposed and validated using experimental data. This approach is coupled with results from a thermal model developed in a recently published paper (1). Solidification and cracking phenomena were also investigated using a SEM (Scanning Electron Microscope) to observe accurately the most significant microstructural features, such as the interdendritic spacings.     

Description and experimental results of a semi-indirect ceramic evaporative cooler

Evaporative cooling is used in industrial and air conditioning processes to reduce temperature in different fluids. Direct evaporation systems can lead to environmental problems such as Legionnaire's disease, and indirect systems reduce system efficiency.This work presents the manufacture, test bed set up and trials carried out on a ceramic evaporative cooling system which acts as a semi-indirect cooler. Depending on air characteristics, it may act as a sensible or enthalpic exchanger. The water cooled in a cooling tower, using the return air coming from the conditioned room (22 °C and 50% comfort conditions) goes through the ceramic pipes, exchanging sensible and latent heat with a current of outdoor air.The use of this recovery system is mainly in climates with a high temperature and humidity such as tropical environments where the system yields a decrease in supply air humidity, using the cooling power of return air.The tests presented show the system behaviour for various supply air conditions.