Telerobotics : methodology for the development of a through-the-internet robotic teleoperated system

This work presents a methodology for the development of Teleoperated Robotic Systems through the Internet. Initially, it is presented a bibliographical review of the Telerobotic systems that uses Internet as way of control. The methodology is implemented and tested through the development of two systems. The first is a manipulator with two degrees of freedom commanded remotely through the Internet denominated RobWebCam (http://www.graco.unb.br/robwebcam). The second is a system which teleoperates an ABB (Asea Brown Boveri) Industrial Robot of six degrees of freedom denominated RobWebLink (http://webrobot.graco.unb.br). RobWebCam is composed of a manipulator with two degrees of freedom, a video camera, Internet, computers and communication driver between the manipulator and the Unix system; and RobWebLink composed of the same components plus the Industrial Robot. With the use of this technology, it is possible to move far distant positioning objects minimizing transport costs, materials and people; acting in real time in the process that is wanted to be controller. This work demonstrates that the teleoperating via Internet of robotic systems and other equipments is viable, in spite of using rate transmission data with low bandwidth. Possible applications include remote surveillance, control and remote diagnosis and maintenance of machines and equipments

Effect of lipids on biomass development in anaerobic fixed-bed reactors treating a synthetic dairy waste

The aim of this work was to follow the evolution in quantity and quality of the biomass developed during the operation of two anaerobic fixed bed reactors treating a synthetic dairy waste with different lipid contents. The feasibility of a special reactor design that allowed the biomass withdrawal with minimum operation disturbances was tested. The HRT was maintained at 1.5 days and the influent concentration was gradually increased from 3 to 12 g COD/l. Initially, one reactor was loaded with skim milk and the other one with whole milk, with equal organic loading rates (OLR). The effect of lipids was evaluated in terms of reactor performance, total, adhered and entrapped biomass and evolution of biomass quality determined in batch assays by: (i) measuring of potential specific methanogenic activity against direct (acetate, H2/CO2) and indirect (propionate and butyrate) substrates; (ii) measuring of the resistance of acetoclastic bacteria to the presence of sodium oleate. The lipids reduced the adhered fraction of biomass. The methanogenic activity against butyrate was enhanced in the presence of lipids, but no significant effect was detected on the other measured activities. The biomass taken from the reactor fed with lipids was more susceptible to the presence of sodium oleate, but, over the operation period, this susceptibility was reduced

Rutura isquémica do músculo papilar ântero-lateral

We describe the case of a 59-year-old man who presented with chest pain and ST-segment elevation in the inferior leads, R>S in V1 and ST depression in the anterior leads due to proximal occlusion of the first obtuse marginal. Primary coronary angioplasty and stenting of this artery were performed. Twelve hours later the patient became hemodynamically unstable and severe mitral regurgitation due to rupture of one of the heads of the anterolateral papillary muscle was diagnosed. Emergency surgery was performed (papillary muscle head reimplantation, mitral annuloplasty with a rigid ring, tricuspid annuloplasty and coronary artery bypass grafting). On surgical inspection, it was observed that the detached muscle head had become trapped in the left ventricle by a secondary cord attached to the other head. This case is unusual in presenting two uncommon features of ischemic papillary muscle: rupture of the anterolateral muscle in myocardial infarction involving the inferoposterior walls, and the fact that the ruptured muscle head did not prolapse because it had become trapped in the left ventricle by secondary cord attachment

Effect of lipids and oleic acid on biomass development in anaerobic fixed-bed reactors. Part I: biofilm growth and activity

Two similar anaerobic fixed-bed bioreactors which allowed the biomass to be periodically withdrawn were run in parallel. After feeding each digester with synthetic dairy wastes of different lipid content (Period I), both digesters were fed with increasing sodium oleate concentrations with skim milk as co-substrate (Period II) and oleate as the sole carbon source (Period III). In Period I, the digester fed with lipids was more effcient and exhibited lower levels of volatile fatty acids than the digester fed without lipids. The biofilm built up in the presence of lipids was thinner, but more resistant to the presence of oleate than the biofilm formed in the absence of lipids, which lost 53% of its solids after contacting with oleic acid. The specific methanogenic activity with butyrate as substrate was enhanced in the presence of lipids, but no significant effect was detected on the acetoclastic and hydrogenophilic activities, which remained similar for both digesters along the trial period

Impact of atrial fibrillation in acute coronary syndrome

INTRODUCTION: Atrial fibrillation (AF) is a relatively common arrhythmia in the context of acute coronary syndromes (ACS). However, the impact of AF on these patients' survival is not well established. The present study aimed to estimate the prevalence of AF in ACS patients and to evaluate its impact on in-hospital and six-month post-event mortality, from any cause. METHODS: This was a retrospective cohort study that included 1183 patients admitted consecutively to a Coronary Care Unit with ACS. Demographic and clinical data and information from various complementary exams were collected and occurrence of AF during the first 48 hours of hospitalization was analyzed. Six-month follow-up was achieved in 95.9% of the patients. Logistic regression statistical analysis was used to identify independent predictors of in-hospital and six-month post-event mortality. RESULTS: AF was diagnosed in 140 patients (11.8%); these patients were older (73.89 +/- 8.69 vs. 63.20 +/- 12.73 years; p75 years, severe left ventricular dysfunction and heart failure. The performance of coronary angiography correlated with improved prognosis. CONCLUSIONS: AF in the context of ACS is an independent predictor of increased in-hospital and six-month mortality. These findings should be taken into consideration in the management and treatment of such patients

Effects of lipids and oleic acid on biomass development in anaerobic fixed-bed reactors. Part II : oleic acid toxicity and biodegradability

Oleic acid toxicity and biodegradability were followed during long-term operation of two similar anaerobic fixed-bed units. When treating an oleate based effluent, the sludge from the bioreactor that was acclimated with lipids during the first operation period, showed a higher tolerance to oleic acid toxicity (IC50=137 mg/l) compared with the sludge fed with a non-fat substrate (IC50=80 mg/l). This sludge showed also the highest biodegradation capacity of oleic acid, achieving maximum methane production rates between 33 and 46 mlCH4_(STP)/gVS.day and maximum percentages of methanization between 85 and 98% for the range of concentrations between 500 and 900 mg oleate/l. When oleate was the sole carbon source fed to both digesters, the biomass became encapsulated with organic matter, possibly oleate or an intermediate of its degradation, e.g. stearate that was degraded at a maximum rate of 99 mlCH4_(STP)/gVS.day. This suggests the possibility of using adsorption-degradation cycles for the treatment of LCFA based effluents. Both tolerance to toxicity and biodegradability of oleic acid were improved by acclimatization with lipids or oleate below a threshold concentration

Influence of lipid acclimatization on the oleic acid toxicity towards methanogenic acetoclastic bacteria

Instituto de Biotecnologia e Química Fina (IBQF)

Influence of lipid acclimatization on the support matrix colonisation in anaerobic filters treating oleic acid

Instituto de Biotecnologia e Química Fina (IBQF)

Prognostic impact of hemoglobin drop during hospital stay in patients with acute coronary syndromes

INTRODUCTION: Bleeding is currently the most common non-cardiac complication of therapy in patients with acute coronary syndromes (ACS), and may itself be associated with adverse outcomes. The aim of this study was to determine the effect of hemoglobin drop during hospital stay on outcome among patients with ACS. METHODS: Using Cox proportional-hazards modeling, we examined the association between hemoglobin drop and death or myocardial infarction (MI) at 6 months in 1172 patients admitted with ACS to an intensive cardiac care unit. Patients were stratified according to quartiles of hemoglobin drop: Q1, or = 2.4 g/dL. We also identified independent predictors of increased hemoglobin drop (> or =2.4 g/dL) using multivariate logistic regression analysis. RESULTS: Median nadir hemoglobin concentration was 1.5 g/dL lower (IQR 0.8-2.3) compared with baseline hemoglobin (p < 0.0001). Independent predictors of increased hemoglobin drop included older Sage, renal dysfunction, lower weight, and use of thrombolytic therapy, glycoprotein IIb/IIIa inhibitors, nitrates, and percutaneous coronary intervention. Higher levels of hemoglobin drop were associated with increased rates of 6-month mortality (8.0% vs. 9.4% vs. 9.6% vs. 15.7%; p for trend = 0.014) and 6-month death/ MI (12.4% vs. 17.0% vs. 17.2% vs. 22.1%; p for trend = 0.021). Using Q1 as reference group, the adjusted hazard ratio (HR) for 6-month mortality and 6-month death/MI among patients in the highest quartile of hemoglobin drop was 1.83 (95% confidence interval [CI] 1.08-3.11; p = 0.026) and 1.60 (95% CI 1.04-2.44; p = 0.031) respectively. Considered as a continuous variable, the adjusted HR for 6-month mortality was 1.16 (95% CI 1.01-1.32; p = 0.030) per 1 g/dL increase in hemoglobin drop. CONCLUSIONS: A decrease in hemoglobin frequently occurs during hospitalization for ACS and is independently associated with adverse outcomes

Smoking in acute coronary syndromes--the "smoker's paradox" revisited

INTRODUCTION: Although a well-known risk factor for coronary disease, smoking has long been associated with lower short-term mortality in acute coronary syndromes (ACS). There are few recent works on Portuguese populations examining all aspects of smoking in ACS, particularly the interaction between smoking and other risk factors, and the management and prognosis of patients according to smoking status. OBJECTIVE: We sought to examine clinical characteristics, presentation, in-hospital treatment, angiographic features and prognosis of patients with and without smoking history admitted with ACS. METHODS: A total of 1228 patients consecutively admitted with ACS from January 2004 to March 2007 were analyzed. Patients were classified into two groups, those with present or past smoking habits (n=450) making up Group I and those without smoking habits (n=778), Group II. The main outcome analyzed was overall mortality during hospital stay and at 6 months. RESULTS: Smokers and former smokers were younger and more frequently male (odds ratio [OR] = 22.46; 95% confidence interval [CI]: 12.94-38.96), and less often had diabetes (OR = 0.41; 95% CI: 0.30-0.54), hypertension (OR = 0.31; 95% CI: 0.24-0.39) and renal insufficiency (OR = 0.26; 95% CI: 0.18-0.36). Patients with smoking habits more frequently presented with ST elevation (OR = 1.32; 95% CI: 1.04-1.67), more often received evidence-based medical therapy, namely beta blockers (during hospital stay, OR = 2.42; 95% CI: 1.63-3.56 and at discharge, OR = 1.45; 95% CI: 1.03-2.1) and statins (at discharge, OR = 2.48; 95% CI: 1.2-6.1), and more frequently underwent coronary angiography (OR = 2.15; 95% CI: 1.63-2.84). Although smokers and former smokers had lower in-hospital mortality on univariate analysis (OR = 0.54; 95% CI: 0.31-0.96), this association was not confirmed on multivariate analysis, with adjustment for known short-term mortality predictors (OR = 1.25; 95% CI: 0.61-2.54). Similarly, multivariate analysis failed to confirm lower 6-month mortality for smokers and former smokers (OR = 2.0; 95% CI: 1.17-3.41). CONCLUSIONS: Clinical characteristics and management options differed between ACS patients with and without smoking habits. These differences explained the lower shortterm mortality initially observed between the two groups. In our population of patients admitted with ACS, we did not find a real "smoker's paradox"