161 research outputs found

    Emergency extra-intracranial bypass surgery in a patient with neurologic deficit after an accident in carotid occlusive test: A case report.

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    OBJECTIVE: BTO is the procedure performed to assess the collateral circulation within the Willis circle in a giant ICA aneurysm. An ICA occlusion after BTO is very rare. We present a case of an internal carotid artery occlusion as a complication of BTO that required urgent revascularization surgery. CASE PRESENTATION: A 56-year-old female with a history of transient ischemic attacks for one year was diagnosed with multiple aneurysms: a giant aneurysm of the left supra-clinoid ICA, two small ones on left MCA and right ophthalmic. A BTO was performed to assess collateral supply and determine whether bypass surgery should be necessary. During the procedure, the balloon was detached while insufflating, and the patient had a subsequent neurological decline consistent with an MCA syndrome. EC-IC bypass surgery was performed with an end-to-side anastomosis of STA-MCA by trapping the giant aneurysm and clipping the ipsilateral MCA aneurysm. The patient had a reversal of neurological symptoms and made an uneventful recovery. DISCUSSION: We discuss the epidemiology of giant ICA aneurysms, the indications for BTO, and its complication. Emergency intracranial and extracranial bypass surgery in case of acute ICA injury is also discussed. We also highlighted the attributable factors to treatment strategies under restrictive conditions in Vietnam. CONCLUSIONS: ICA occlusion due to insufflated balloon detachment is an unreported complication in literature. Emergency bypass surgery is a potential treatment choice for this unusual iatrogenic complication

    VLSP SHARED TASK: SENTIMENT ANALYSIS

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    Sentiment analysis is a natural language processing (NLP) task of identifying orextracting the sentiment content of a text unit. This task has become an active research topic since the early 2000s. During the two last editions of the VLSP workshop series, the shared task on Sentiment Analysis (SA) for Vietnamese has been organized in order to provide an objective evaluation measurement about the performance (quality) of sentiment analysis tools, and encouragethe development of Vietnamese sentiment analysis systems, as well as to provide benchmark datasets for this task. The rst campaign in 2016 only focused on the sentiment polarity classication, with a dataset containing reviews of electronic products. The second campaign in 2018 addressed the problem of Aspect Based Sentiment Analysis (ABSA) for Vietnamese, by providing two datasets containing reviews in restaurant and hotel domains. These data are accessible for research purpose via the VLSP website vlsp.org.vn/resources. This paper describes the built datasets as well as the evaluation results of the systems participating to these campaigns

    Robust Adaptive Neural-Fuzzy Network Tracking Control for Robot Manipulator

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    This paper presents a robust adaptive neural-fuzzy network control (RANFNC) system for an n-link robot manipulator to achieve the highprecision position tracking. Initially, the model dynamic of an n-link robot manipulator is introduced. However, it is difficult to design a conformable model-based control scheme, for instance, external disturbances, friction forces and parameter variations. In order to deal with this problem, the RANFNC system is investigated to the joint position control of an n-link robot manipulator. In this control scheme, a four-layer neural-fuzzy-network (NFN) is used for the main role, and the adaptive tuning laws of network parameters are derived in the sense of a projection algorithm and the Lyapunov stability theorem to ensure network convergence as well as stable control performance. The merits of this model-free control scheme are that not only the stable position tracking performance can be guaranteed but also unknown system information and auxiliary control design are required in the control process. The simulation results are provided to verify the effectiveness of the proposed RANFNC methodology

    Monitoring for Plasmodium falciparum drug resistance to artemisinin and artesunate in Binh Phuoc Province, Vietnam: 1998-2009

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    <p>Abstract</p> <p>Background</p> <p>Artemisinin derivatives have been used for malaria treatment in Vietnam since 1989. Reported malaria cases have decreased from 1,672,000 with 4,650 deaths in 1991, to 91,635 with 43 deaths in 2006. Current national guidelines recommend artemisinin-based combination therapy (ACT), although artesunate is still available as monotherapy through the private sector. Recent reports suggest that effectiveness of ACT and artesunate monotherapy has declined in western Cambodia. This study examined <it>Plasmodium falciparum </it>resistance patterns over 10 years in southwest Vietnam in infected patients treated with artemisinin compounds.</p> <p>Methods</p> <p>The study was conducted in two communes in Phuoc Long district, Binh Phuoc province, 100 km west of the Cambodian border. This was chosen as a likely site for emerging artemisinin resistance because of the high prevalence of <it>P. falciparum </it>malaria, and the length of time that artemisinin had been in use. In <it>vivo </it>and <it>in vitro </it>monitoring of <it>P. falciparum </it>susceptibility to anti-malarial drugs was conducted in 1998, 2001, 2004/5, and 2008/9. Patients with confirmed <it>P. falciparum </it>malaria received therapy with 5 or 7 days of artemisinin (1998 and 2001 respectively) or 7 days of artesunate</p> <p>Results</p> <p>In the four surveys, 270 patients were recruited and treated. The mean parasite clearance times differed between 1998, 2001 and 2004/5 (1.8, 2.3 and 2.1 days, P < 0.01) but not between 1998 and 2008/2009. The mean parasite clearance times were correlated with parasite density at day 0 (r = 0.4; P < 0.001). Treatment failure rates after PCR adjustment were 13.8%, 2.9%, 1.2%, and 0% respectively. Susceptibility of <it>P. falciparum </it>to artemisinin in <it>in vitro </it>tests was stable during the period, except for a rise in EC90 and EC99 in 2001.</p> <p>Conclusions</p> <p>This study showed stable levels of <it>P. falciparum </it>sensitivity to artemisinin compounds in the two sites over a ten-year period. The introduction of ACT in this area in 2003 may have protected against the development of artemisinin resistance. Adherence to the latest WHO and Vietnamese guidelines, which recommend ACT as first-line therapy in all malarious areas, and continued monitoring along the Vietnam-Cambodia border will be essential to prevent the spread of artemisinin resistance in Vietnam.</p

    An Adaptive Iterative Learning Control for Robot Manipulator in Task Space

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    In this paper, adaptive iterative learning control (AILC) of uncertain robot manipulators in task space is considered for trajectory tracking in an iterative operation mode. The control scheme incluces a PD controller with a gain switching technique plus a learning feedforward term, is exploited to predict the desired actuator torque. By using Lyapunov method, an adaptive iterative learning control scheme is presented for robotic system with both structured and unstructured uncertainty, and the overall stability of the closed-loop system in the iterative domain is established. The validity of the scheme is confirmed through a numerical simulation

    Advanced Rooftop Control (ARC) Retrofit: Field-Test Results

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    The multi-year research study was initiated to find solutions to improve packaged equipment operating efficiency in the field. Pacific Northwest National Laboratory (PNNL), with funding from the U.S. Department of Energy’s (DOE’s) Building Technologies Office (BTO) and Bonneville Power Administration (BPA) conducted this research, development and demonstration (RD&D) study. Packaged equipment with constant speed supply fans is designed to provide ventilation at the design rate at all times when the fan is operating as required by building code. Although there are a number of hours during the day when a building may not be fully occupied or the need for ventilation is lower than designed, the ventilation rate cannot be adjusted easily with a constant speed fan. Therefore, modulating the supply fan in conjunction with demand controlled ventilation (DCV) will not only reduce the coil energy but also reduce the fan energy. The objective of this multi-year research, development and demonstration project was to determine the magnitude of energy savings achievable by retrofitting existing packaged rooftop air conditioners with advanced control strategies not ordinarily used for packaged units. First, through detailed simulation analysis, it was shown that significant energy (between 24% and 35%) and cost savings (38%) from fan, cooling and heating energy consumption could be realized when packaged air conditioning units with gas furnaces are retrofitted with advanced control packages (combining multi-speed fan control, integrated economizer controls and DCV). The simulation analysis also showed significant savings for heat pumps (between 20% and 60%). The simulation analysis was followed by an extensive field test of a retrofittable advanced rooftop unit (RTU) controller

    Energy-loss Function for Lead

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    We study the energy-loss function for lead in the framework of the time-dependent density functional theory, using the full-potential linearized augmented plane-wave plus local orbitals method. The ab initio calculations are performed in the adiabatic local density approximation. The comparison between the obtained energy-loss function for zero momentum transfer with those from reflection electron energy loss spectroscopy measurements and from first-principles calculations shows good agreement

    Plasmodium knowlesi malaria in Vietnam: some clarifications

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    A recently published comment on a report of Plasmodium knowlesi infections in Vietnam states that this may not accurately represent the situation in the study area because the PCR primers used may cross-hybridize with Plasmodium vivax. Nevertheless, P. knowlesi infections have been confirmed by sequencing. In addition, a neighbour-joining tree based on the 18S S-Type SSUrRNA gene shows that the Vietnamese samples clearly cluster with the P. knowlesi isolates identified in Malaysia and are distinct from the corresponding P. vivax sequences. All samples came from asymptomatic individuals who did not consult for fever during the months preceding or following the survey, indicating that asymptomatic P. knowlesi infections occur in this population, although this does not exclude the occurrence of symptomatic cases. Large-scale studies to determine the extent and the epidemiology of P. knowlesi malaria in Vietnam are further needed
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