RESUMO
OBJECTIVE: Neuromodulatory anterior thalamic deep brain stimulation (DBS) is an effective therapy for intractable epilepsy, but few patients achieve complete seizure control with thalamic DBS. Other stimulation sites may be considered for anti-seizure DBS. We investigated bilateral low-frequency stimulation of the endopiriform nuclei (LFS-EPN) to control seizures induced by intracortically implanted cobalt wire in rats. METHODS: Chronic epilepsy was induced by cobalt wire implantation in the motor cortex unilaterally. Bipolar-stimulating electrodes were implanted into the EPN bilaterally. Continuous electroencephalography (EEG) was recorded using electrodes placed into bilateral motor cortex and hippocampus CA1 areas. Spontaneous seizures were monitored by long-term video-EEG, and behavioral seizures were classified based on the Racine scale. Continuous 1-Hz LFS-EPN began on the third day after electrode implantation and was controlled by a multi-channel stimulator. Stimulation continued until the rats had no seizures for three consecutive days. RESULTS: Compared with the control and sham stimulation groups, the LFS-EPN group experienced significantly fewer seizures per day and the mean Racine score of seizures was lower due to fewer generalized seizures. Ictal discharges at the epileptogenic site had significantly reduced theta band power in the LFS-EPN group compared to the other groups. INTERPRETATION: Bilateral LFS-EPN attenuates cobalt wire-induced seizures in rats by modulating epileptic networks. Reduced ictal theta power of the EEG broadband spectrum at the lesion site may be associated with the anti-epileptogenic mechanism of LFS-EPN. Bilateral EPN DBS may have therapeutic applications in human partial epilepsies.
Assuntos
Terapia por Estimulação Elétrica , Epilepsia/terapia , Córtex Motor/fisiopatologia , Córtex Piriforme , Ritmo Teta/fisiologia , Animais , Região CA1 Hipocampal/fisiopatologia , Estimulação Encefálica Profunda , Modelos Animais de Doenças , Eletrocorticografia , Neuroestimuladores Implantáveis , Masculino , Ratos , Ratos Sprague-Dawley , ConvulsõesRESUMO
Uranium (VI) is very essential element in nuclear technique and the enrichment uranium has attracted lots of attention. In this work, l-Arginine and Ag nanoparticles (AgNPs) functionalized reduced graphene oxide ternary hydrogel composites (Ag-l-Arg-rGH) were successfully synthesized, which combined the insertion of AgNPs with one-step thermal reduction and an assembly of graphene oxide nanosheets, using l-Arginine (l-Arg) as both a functional and cross-linking agents. The Ag-l-Arg-rGH composites exhibited great enhanced sorption capacity. Kinetic data best fitted the pseudo-second-order model. The thermodynamic data fitted the Langmuir isotherm model and the calculated maximum adsorption capacity is 434.78â¯mg/g. In addition, the anti-algae experimental results indicated adsorbent showed marked algal inhibition with the presence of AgNPs in the Ag-l-Arg-rGH composites. In the simulated seawater experiments, The distribution coefficient (Kd) value of uranium(VI) with other competing ions was 2.41â¯×â¯104 mL g-1. Thereby, the Ag-l-Arg-rGH composites possessed a promising potential for the enrichment uranium (VI) from nature seawater.
Assuntos
Arginina/química , Grafite/química , Hidrogéis/química , Nanopartículas Metálicas/química , Prata/química , Urânio/farmacologia , Adsorção , Cinética , Microalgas/química , Microalgas/efeitos dos fármacos , Tamanho da Partícula , Propriedades de Superfície , Urânio/químicaRESUMO
This paper presents the design of a wireless, implantable, multi-channel, programmable stimulator with arbitrary channel combination. A novel channel management module using a switch array is presented, enabling arbitrary channel configuration with a silicon area reduction of 81%. The chip was fabricated in a 0.18- µ m Taiwan semiconductor manufacturing company (TSMC) high voltage (HV) complementary metalâ»oxide semiconductor (CMOS) technology. A stimulator system was realized using the proposed integrated circuit (IC). A wireless communication link was established between a specified Android-based graphical user interface (GUI) and the proposed device for control of the stimulation pattern and wireless battery charging. The size of the entire system occupies a volume of only 14 mm × 14 mm × 4 mm (without the battery). Experimental results demonstrated a successful independent configuration between different channels, as well as an arbitrary channel combination, as expected.
RESUMO
In this study, uranium(VI) was successfully removed from aqueous solutions using heat-treated carbon microspheres based on a batch adsorption technique. Influence of the parameters, such as solution pH, contact time, initial uranium(VI) concentration, and temperature on the removal efficiency have been investigated in detail. The results reveal that the maximum adsorption capacity of the heat-treated carbon microspheres toward uranium(VI) is 92.08 mg g(-1), displaying a high efficiency for the removal of uranium(VI) from aqueous solution. The experimental data are analyzed using sorption kinetic models. It is revealed that the process obey the pseudo-second-order kinetic model, the determining step might be chemical sorption. The thermodynamic parameters, such as ΔH°, ΔS°, and ΔG° show that the process is endothermic and spontaneous. This work provides an efficient, fast, and convenient approach for the removal of uranium(VI) from aqueous solutions.
Assuntos
Carbono/química , Microesferas , Urânio/química , Poluentes Radioativos da Água/química , Adsorção , Carbono/análise , Recuperação e Remediação Ambiental/métodos , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Modelos Químicos , Termodinâmica , Urânio/análise , Poluentes Radioativos da Água/análise , Purificação da Água/métodosRESUMO
In this study, nitrobenzene in water and ice samples collected from the Songhua River after the explosion of a petrochemical plant was determined by GC/MS. The results showed that nitrobenzene was detected in most of the water and ice samples taken from the Songhua River. However, the concentration of nitrobenzene in all water and ice samples was from 0 to 0.65 microg L(-1); this range was sufficiently lower than the permissible level (0.017 mg L(-1)) for drinking water in China. The enclosing behavior of nitrobenzene in ice was also investigated. The amount of nitrobenzene enclosed in ice was lower than that reported by UNEP.
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Explosões , Gelo/análise , Nitrobenzenos/análise , Nitrobenzenos/química , Petróleo , Rios/química , Água/química , ChinaRESUMO
Study on dye-sensitized solar cells (DSSCs) with extracts of Canna indica L., Salvia splendens, Solanum nigrum L. as sensitizers is firstly reported in this paper. DSSCs were assembled by using natural dyes extracted from C. indica L., S. splendens, cowberry and S. nigrum L. as sensitizers. The energy conversion efficiency of the cells sensitized with dyes of C. indica L., S. splendens, cowberry and S. nigrum L. was 0.29%, 0.26%, 0.13% and 0.31%, respectively. A novel technique was taken to fabricate TiO(2) electrode films by electrophoresis. We present FTIR and UV-vis spectroscopy studies of structures and light absorption of these four kinds of natural dyes. The electrochemical impedance spectroscopy (EIS) was used to analyze the interface resistance of cells. The result indicated that high resistance existed in the interfaces of cell with cowberry extract as sensitizer.