2,580 research outputs found

    Tiagabine add‐on for drug‐resistant partial epilepsy

    Get PDF
    Cochrane Database Syst Rev. 2002;(3):CD001908. Tiagabine add-on for drug-resistant partial epilepsy. Pereira J, Marson AG, Hutton JL. Servico de Neurologia, Hospital de Santo Antonio, Largo Prof. Abel Salazar, 4099-001 Porto, Portugal. [email protected] Abstract BACKGROUND: Epilepsy is a common neurological condition, affecting almost 0.5 to 1 per cent of the population. Nearly 30 per cent of people with epilepsy are resistant to currently available drugs. Tiagabine is one of the newer antiepileptic drugs and its effects as an adjunct (add-on) to standard drugs is assessed in this review. OBJECTIVES: To evaluate the effects of add-on treatment with tiagabine upon seizures, side effects, cognition and quality of life for people with drug-resistant localization related seizures. SEARCH STRATEGY: We searched the Cochrane Epilepsy Group trials register (28 March 2002), the Cochrane Controlled Trials Register (Cochrane Library Issue 1, 2002), MEDLINE (1966 to November 2001). In addition, we contacted Sanofi~Synthelabo (makers of tiagabine) and experts in the field to seek any unpublished or ongoing studies. SELECTION CRITERIA: Randomized placebo controlled add-on trials of people of any age with localization related seizures, in which an adequate method of concealment of randomization was used. The studies could be double, single or unblinded and be of parallel or crossover design. They had to have a minimum treatment period of eight weeks. DATA COLLECTION AND ANALYSIS: Two reviewers independently selected trials for inclusion and extracted data. Any disagreements were resolved by discussion. Outcomes investigated included 50 per cent or greater reduction in seizure frequency; treatment withdrawal; side effects; effects on cognition and quality of life. The primary analyses were by intention-to-treat. Worst case and best case analyses were also calculated for seizure outcomes. Dose response was evaluated in regression models. MAIN RESULTS: Three parallel group and two crossover group trials were included. The overall relative risk (RR) for a 50 per cent or greater reduction in seizure frequency (tiagabine versus placebo) was 3.16(95% confidence interval 1.97 to 5.07). Due to differences in response rates among trials, regression models were unable to provide reliable estimates of responses to individual doses. The RR for treatment withdrawal was 1.81(95% confidence interval 1.25 to 2.62). The 99% confidence interval for the following side effects: dizziness; fatigue; nervousness and tremor did not include unity, indicating that they are significantly associated with tiagabine. For cognitive and quality of life outcomes the limited data available suggested that there were no significant effects on cognition and mood and adjustment. REVIEWER'S CONCLUSIONS: Tiagabine reduces seizures frequency but is associated with some side effects when used as an add-on for people with drug-resistant localization related seizures. PMID: 12137637 [PubMed - indexed for MEDLINE] Publication Types, MeSH Terms, SubstancesPublication Types: Review MeSH Terms: Anticonvulsants/adverse effects Anticonvulsants/therapeutic use* Drug Resistance Epilepsies, Partial/drug therapy* Humans Nipecotic Acids/adverse effects Nipecotic Acids/therapeutic use* Substances: Anticonvulsants Nipecotic Acids tiagabine LinkOut - more resource

    The Alchemist

    Get PDF
    This investigation uses a recent methodology, essentially based on our evolutionary algorithm (EA) to get new insights about the energetics and structure of the first solvation shells of lithium ion in polar solvents that form important hydrogen bonds. We employed the EA to search for the low-energy structures of the Li+(H2O)n and Li+(CH3OH)n clusters (with n â©œ 20) as modeled by commonly used rigid nonpolarizable force-field potentials. Particular emphasis is given to the characterization of the putative global minima; for Li+(H2O)17, the EA discovered a new global minimum with five water molecules directly coordinating the ion. Smaller-size clusters were, then, re-optimized by employing electronicstructure methods, namely, DFT (with the B3LYP functional and both the 6-31+G∗ and 6-311+G∗∗ basis sets) and MP2 (with the aug-cc-pVDZ basis set). In the case of Li+(H2O)n, the ab initio global minimum structures are similar to those obtained with the EA up to n = 10. However, for n = 17, the structure of the global minimum discovered by the EA is different from the lowest-energy cluster obtained after re-optimization at the MP2/aug-cc-pVDZ level of theory. Such energy reorder may be attributed to the water–water interaction. As for the Li+(CH3OH)n clusters, the re-optimization process leads more often to a reorder in the energy of the minimum structures. Thus, forfluxional clusters like the Li+(CH3OH)n ones that show a huge number of stationary configurations within a small energy window, it is mandatory to carefully choose various structures, besides the global minimum, to be re-optimized at the ab initio or DFT levels. Due to the difficulty on choosing adequate departing structures by the usually employed chemical intuition, we noticed that some low-energy minima (including the global one) of even small Li+(CH3OH)n clusters were missed in literature. We showcase this problem in the Li+(CH3OH)6 cluster, whose vibrational frequencies in the C–O stretching region and corresponding infrared intensities were calculated at the DFT level of theory and compared with previously reported results

    Performance analysis of pressurized irrigation systems operating on-demand using flow-driven simulation models

    Get PDF
    On-demand pressurized irrigation systems are designed to deliver water with the flow rate and pressure required by the farm irrigation systems, sprinkling or micro-irrigation, and respecting the time, duration and frequency decided by the farmers. Due to the variation in farm demand along the season and the day, a large spatial and temporal variability of flow regimes occurs in these systems, which may affect the performance of the farm systems and the yields of the irrigated crops. Therefore, there is a need to analyse those systems to identify and solve performance problems. In this research, two simulation models for the analysis of irrigation systems operating on-demand, ICARE and AKLA, are used and compared to assess the hydraulic performance of the irrigation network of the Lucefecit Irrigation System, in Southern Portugal. ICARE assesses the global performance of the irrigation system through the indexed characteristic curves, while AKLA provides for the identification of the relative pressure deficit and reliability at every hydrant. Both models adopt a flow-driven analysis approach, performing the analysis for multiple flow regimes. To support the hydraulic characterization of the system and for calibration of the steadystate hydraulic model, field measurements were performed at selected nodes of the network, including four hydrants. The analysis with ICARE does not provide for a sufficient identification of problems. In fact, poor performance is indicated when a few hydrants operate below the minimum pressure set at design. Differently, the analysis with AKLA, applied at the hydrant level, shows that the performance of the Lucefecit system is generally acceptable. AKLA identifies which hydrants operate below the required pressure and, therefore, allows to support any eventual related improvement. Results show that the performance of the system highly improved when changing the piezometric elevation from 260 to 265m a.s.l. However, this improvement is not sufficient because three hydrants still have high relative pressure deficit and low reliability. Solutions for those hydrants require increasing diameters of network pipes supplying them

    Bounds on Relativistic Deformed Kinematics from the Physics of the Universe Transparency

    Get PDF
    We analyze the kinematics of electron-positron production in a photon-photon interaction when one has a modification of the special relativistic kinematics as a power expansion in the inverse of a new high-energy scale. We derive the equation for the threshold energy of this reaction to first order in this expansion, including the effects due to a modification of the energy-momentum conservation equation. In contrast with the Lorentz invariance violation case, a scale of the order of a few TeV is found to be compatible with the observations of very high-energy cosmic gamma rays in the case of a modification compatible with the relativity principle

    Lie theory and separation of variables. 5. The equations iUt + Uxx = 0 and iUt + Uxx −c/x2 U = 0

    Get PDF
    A detailed study of the group of symmetries of the time-dependent free particle Schrödinger equation in one space dimension is presented. An orbit analysis of all first order symmetries is seen to correspond in a well-defined manner to the separation of variables of this equation. The study gives a unified treatment of the harmonic oscillator (both attractive and repulsive), Stark effect, and free particle Hamiltonians in the time dependent formalism. The case of a potential c/x2 is also discussed in the time dependent formalism. Use of representation theory for the symmetry groups permits simple derivation of expansions relating various solutions of the Schrödinger equation, several of which are new

    Physics of the universe transparency in a deformed kinematics

    Get PDF
    We present a first study of the possible effects of a relativistic deformation of special relativity in the recent observations of very high-energy gamma rays by the LHAASO experiment, which has opened a new phenomenological window to study deformations in the kinematics of special relativity. Our analysis of the interaction of high-energy photons with the CMB background complements theoretical studies based on Lorentz invariance violation scenarios, while making predictions that would allow one to distinguish between a violation and a deformation of the symmetries of special relativity

    Decennial comparison of changes in social vulnerability: a municipal analysis in support of risk management

    Get PDF
    The concept of Social Vulnerability (SV) is characterized and distinguished by its complexity and multidisciplinarity. This concept takes into account the specific characteristics of the individual and his social and economic relations, as well as the physical environment where he is inserted. These differentiating characteristics make Social Vulnerability (SV) an indispensable work tool in the process of characterizing and understanding the degree of exposure of communities, as well as evaluating their capacity for resilience and recovery from hazardous events. This paper presents a comparison between the SV performed in 2008 with the results obtained in 2017 for the 278 municipalities of mainland Portugal. The methodology was based on the work developed by the Center for Social Studies of the University of Coimbra, which is distinguished by the fact that SV is composed of two components: Criticity and Support Capability. The analysis of SV and its components was done using Principal Components Analysis (PCA) starting from an initial set of 235 variables (90 for Criticality and 145 for Support Capability). With respect to Criticality, the results point out the importance of factors related to the economic condition, employment and factors related to the disadvantaged population and risk groups. Support Capability is strongly influenced by the population density and the most relevant factors for the final results are those related to civil protection response, economic and environmental dynamism and logistic and service capacity. Regarding the SV spatial distribution, the highest values are located mainly in the central and northern parts of the country, with emphasis on the Douro river valley and surrounding municipalities; also a general decrease of SV was recorded in the southern regions from 2008 to 2017.info:eu-repo/semantics/publishedVersio

    Chirped polymer optical fiber Bragg grating sensors

    Get PDF
    We report chirped fiber Bragg gratings (CFBGs) photo-inscribed in undoped PMMA polymer optical fibre (POF) for the first time. The chirped polymer optical fiber Bragg gratings (CPOFBGs) were inscribed using an UV KrF excimer laser operating at 248 nm. The rectangular gauss laser beam was expanded to 25 mm in horizontal direction along the fiber core by a cylindrical lens, giving a total of 25 mm grating length. A 25 mm long chirped phase mask chosen for 1550 nm grating inscription was used. The laser frequency was 1 Hz with an energy of 5 mJ per exposure, exposing few pulses for each grating inscription. The reflection amplitude spectrum evolution of a CPOFBG is investigated as a function of the applied strain and temperature. Also, some results regarding to group delay are collected and discussed. These results pave the way to further developments in different fields, where POFs could present some advantages preferably replacing their silica counterparts

    Models of electron transport in single layer graphene

    Full text link
    The main features of the conductivity of doped single layer graphene are analyzed, and models for different scattering mechanisms are presented.Comment: 15 pages. Submitted to the Proceedings of the ULTI symposium on Quantum Phenomena and Devices at Low Temperatures, Espoo, Finland, to be published in the Journ. of Low. Temp. Phy

    The usefulness of serum adenosine deaminase 2 (ADA2) activity in adults for the diagnosis of pulmonary tuberculosis

    Get PDF
    AbstractRapid diagnosis of Mycobacterium tuberculosis remains an obstacle for therapy of tuberculosis (TB). Adenosine deaminase isoform 2 (ADA2) is produced by activated macrophages and has been used for diagnosis of TB from extra-pulmonary sites. However, few studies adequately address whether serum ADA2 activity is useful for diagnosis of active pulmonary tuberculosis (PTB). We prospectively measured serum ADA2 activity in 110 patients with pulmonary disease (65 cases with active PTB and 45 cases with other respiratory diseases) and 78 healthy volunteers (eight with tuberculin skin test positive). The serum ADA2 for the diagnosis of PTB had the sensitivity of 36·9%, the specificity of 84·5%, the positive predictive value of 10·9% and the negative predictive value of 96·2%. We concluded that serum ADA2 activity is neither useful to diagnosis of active PTB nor to differentiate from other respiratory diseases
    • 

    corecore