RESUMEN
Aluminum nitride containing diamond-like carbon was fabricated with pulsed laser deposition without post processing. The compositions of the targets used were varied at 1, 5, 10, 15 at.% and pure carbon was used as a reference. The films were comprehensively characterized with Atomic force microscope (AFM), X-ray photoelectron spectroscopy (XPS) and Transmission electron microscopy (TEM). Roughness analysis using AFM showed an increasing root-mean-square (RMS) roughness with increasing AIN content in target, while XPS analysis showed that the aluminum-nitrogen bonding was still present in the films after the fabrication process. Microstructural studies and selected area electron diffraction (SAED) pattern confirmed the presence of AIN crystals in DLC matrix. This nanostructured composite material is useful for luminescence applications.
RESUMEN
The influence of body temperature on focal cerebral ischaemia-reperfusion was investigated by using a well established rat stroke model. Three different degrees of ischaemia were created in the cerebral cortex of the right middle cerebral artery territory by varying the duration of clamping of the bilateral common carotid arteries and the right middle cerebral artery with full reperfusion. Mild hyperthermic (body temperature 38-39 degrees C) influence during ischaemia significantly enhanced the severity of infarction in mild (30 min) ischaemia, mean infarct volume was 78% greater than normothermic (body temperature 36.5-37.5 degrees C) group (P < 0.001); and in moderate (60 min) ischaemia, mean infarct volume was 23% greater than in the normothermic group (P < 0.05); but no difference between the two groups was observed in severe (90 min) ischaemia. Our data suggest that mild whole body hyperthermia during focal ischaemia-reperfusion has a detrimental effect on the infarct volume only in mild and moderate ischaemia in this model.
RESUMEN
Several methods have been used to predict successful weaning and extubation among chronic obstructive pulmonary disease (COPD) patients. The objective of this study is to determine whether carbon dioxide recruitment threshold (PCO2RT) can be used as adjunct to conventional weaning parameters to predict early weaning and successful extubation. Twelve COPD patients who were ready to be extubated based on conventional weaning parameters were divided into group A (n = 7) and group B (n = 5). Group A were those patients with better weaning parameters and hence a higher probability of successful extubation as compared to group B. Carbon dioxide apnoeic threshold (PCO2AT) was obtained by hyperventilating the patient using an increment of two breaths per min until apnoea occurs. At this point, the PCO2AT or the PaCO2 during said apnoeic period was recorded. A dead space of 150 cc is then added to the circuit until the patient starts to breathe as evidenced by the sensitivity trigger indicator. The PCO2 obtained at this period is termed PCO2RT. After weaning for 30 min on a T-tube, another arterial blood gas is determined and this is called the PCO2SB or the CO2 level after 30 min on spontaneous breathing. If the PCO2SB-PCO2RT difference is high with a sensitivity of 85.71% and specificity of 100% vs sensitivity of 57.14% and specificity of 60% using the conventional weaning parameters. Thus an increase in PCO2SB at 30 min T-tube is indicative of impending respiratory pump failure and that other causes of failure to wean must be investigated.