257 research outputs found
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
Prognostic of RUL based on Echo State Network Optimized by Artificial Bee Colony
Prognostic is an engineering technique used to predict the
future health state or behavior of an equipment or system. In
this work, a data-driven hybrid approach for prognostic is
presented. The approach based on Echo State Network (ESN)
and Artificial Bee Colony (ABC) algorithm is used to predict
machine’s Remaining Useful Life (RUL). ESN is a new
paradigm that establishes a large space dynamic reservoir to
replace the hidden layer of Recurrent Neural Network
(RNN). Through the application of ESN is possible to
overcome the shortcomings of complicated computing and
difficulties in determining the network topology of traditional
RNN. This approach describes the ABC algorithm as a tool
to set the ESN with optimal parameters. Historical data
collected from sensors are used to train and test the proposed
hybrid approach in order to estimate the RUL. To evaluate
the proposed approach, a case study was carried out using
turbofan engine signals show that the proposed method can
achieve a good collected from physical sensors (temperature,
pressure, speed, fuel flow, etc.). The experimental results
using the engine data from NASA Ames Prognostics Data
Repository RUL estimation precision. The performance of
this model was compared using prognostic metrics with the
approaches that use the same dataset. Therefore, the ESNABC approach is very promising in the field of prognostics
of the RUL
Incidence of in-stent restenosis over 13 years - a study based on a national registry
Background: In-stent restenosis (ISR) is one drawback of coronary angioplasty with stent implantation.
Purpose: We investigated the incidence of ISR, its clinical presentation and treatment from a national registry.
Methods: From all patients (pts) undergoing percutaneous coronary intervention (PCI) from 2002 to 2014, we selected those who had previous history of PCI (n=15326). ISR was defined as diameter stenosis ≥ 50% in stent segment, being selected the interventions in which, at least, 1 IRS lesion was treated (n=3069). They were divided in 3 temporal groups:2002-2003 (group 1, n=179, 5.8%)– bare metal stent era; 2004-2008 (group 2,n=816, 26.6%)– 1st generation stent era; 2009-2014 (group 3, n=2074, 67.6%)– 2nd generation stent era. For each group we compared clinical features and treatment.
Results: Over time, it has been observed a reduction in IRS incidence (24.8 vs 23.5 vs 18.6%;p for trend <0.001). Pts from group 3 were older (p=0.01), had higher prevalence of hypertension (63.7 vs 75.6 vs 78.4%;p<0.001), dyslipidemia (61.5 vs 68.5 vs 73.9%;p<0.001) and diabetes (31.3 vs 33.5 vs 38.5%;p=0.012). They also had more frequently history of previous myocardial infarction (p<0.001). Although admissions were more frequently due to stable angina (41% of total) or post non-ST segment myocardial infarction (16.3% of total); it was noticed, over time, an increase in admissions due to ST segment elevation myocardial infarction (1.1 vs 7.4 vs 11.4%;p<0.001) and unstable angina (1.1 vs 1.8 vs 3.7%;p<0.001). Most of pts presented with good systolic ventricular function, but an increase of pts with moderated (2.6 vs 9.0 vs 11.2%;p<0.001) and severe (1.3 vs 1.4 vs 4.7%;p<0.001) systolic dysfunction was observed. From 3069 PCI performed, a total of 3461 IRS lesions were treated. It was observed, at most, 3 IRS lesions for PCI. Over time, the most frequent presentation was 1 lesion for PCI (88.4% of total), being noticed a decreasing in number of multiple IRS lesions (15.1 vs 11.3 vs 9.6%;p=0.035). Incidence of ISR has increased in left descendant coronary artery (34.5 vs 39.8 vs 42.4%;p<0.001) and treatment was more frequently performed in more complex lesions (p<0.001). It was noticed a reduction in treatment with stent (72.7 vs 74.4 vs 52.8%;p<0.001) and an increasing use of only PCI balloon (39.3 vs 57.8 vs 45.8%;p=0.002) and trombectomy (0.0 vs 2.2 vs 8.2%;p<0.001).
Conclusion: In spite of increasing in risk profile of pts over time, it was observed a reduction of incidence of ISR and multiple ISR lesions. It also was observed an increasing number of interventions avoiding second stent implantation
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
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
Influence of lipid acclimatization on the oleic acid toxicity towards methanogenic acetoclastic bacteria
Instituto de Biotecnologia e Química Fina (IBQF)
Modified shock index - a strong preditor of outcome among patients presenting ST-segment elevation myocardial infarction
Background: Prompt identification of higher risk patients presenting with ST-elevation myocardial infarction (STEMI) and undergoing primary percutaneous coronary intervention will allow a more assertive strategy and approach.
Aim: To evaluate the modified shock index (MSI) - a ratio of heart rate (HR) to mean blood pressure (MAP), as a predictor of in hospital and 6-month mortality among patients (pts) admitted with STEMI.
Methods: We analyzed retrospectively 2389 pts admitted consecutively in our coronary care unit with acute coronary syndrome, from July of 2009 to June 2014 and we selected those who presented with STEMI (n=1140). They were divided in two groups: group 1 – pts with MSI <1.3, n=1076, 94.4%); group 2 – pts with MSI ≥1.3 (n=64, 5.6%). For each group we compared clinical and laboratory features and adverse events. Primary endpoint was the occurrence of death at 6 months; follow-up was completed in 99% of patients.
Results: Patients of group 2 were older (62±14 vs 67±14; p=0.003), more frequent women (19% vs 37.5%; p1 (18.0% vs 56.3%; p<0.001), Killip=4 (2.9% vs 28.1%; p<0.001), anaemia (20.9% vs 48.4%; p<0.001) and renal insufficiency (eGFR<60 ml/min) (21.8% vs 42.6%; p<0,001). They also presented more severe coronary disease - left main coronary artery or 3 vessels disease (16.3% vs 31.3%; p=0.005) and higher prevalence of moderate to severe systolic dysfunction (48.3% vs 68.9%; p=0.009). They required more often aminergic support (7.4% vs 50%; p<0.001), intra-aortic balloon pump (2.9% vs 38.3%; p<0.001) and mechanical ventilation (2.6% vs 17.4%; p<0.001). They also had higher prevalence of malignant arrhythmias (6.1% vs 15.6%; p= 0.008) and mechanical complications (1.7 vs 6.3%; p=0.031). Compared with 1st group, the 2nd group had 6.42 times higher in hospital mortality [OR 6.42; 95% CI (4.07 – 12.67)]; p <0.001] and 7.18 times higher 6-month mortality [OR 7.18; 95% CI (3.30 - 12.46)]; p <0.001]. After adjusting for different baseline characteristics in multivariate analysis, MSI ≥1.3 remained as independent predictor of overall 6-month mortality [OR 3.81, 95% CI (1.81-8.03), p<0.001].
Conclusion: Modified shock index ≥1.3 is a stronger predictor of in hospital and 6 month mortality among patients with STEMI
O futuro do cooperativismo de leite.
bitstream/item/132478/1/Livro-O-futuro-do-cooperativismo.pd
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