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1.
Chemosphere ; 352: 141449, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38354864

RESUMEN

Carbamazepine (CBZ) is a pharmaceutical compound detected in various water resources. With a view to removing this contaminant, the applicability of non-thermal plasma (NTP) oxidation process has been widely tested in recent years. This study utilized NTP from a dielectric barrier discharge reactor in the treatment of CBZ. NTP on the surface of a water sample containing 25 mg.L-1 of CBZ resulted in a removal efficiency of over 90% with an energy yield of 0.19 g. (kWh)-1. On the other hand, a rapid reduction in pH and an increase of conductivity and nitrate/nitrite ions concentration were observed during the degradation. The applied voltage amplitude significantly affected the removal efficiency and the energy yield as the degradation efficiency was 55%, 70%, and 72% respectively with an applied voltage of 8, 10, and 12 kV. The water matrices containing inorganic anions such as chloride and carbonate ions reduced the removal efficiency by scavenging the reactive species. Accordingly, a reduction in the removal efficiency was observed in tap water. The high-resolution mass spectrometry (HRMS) results revealed that both reactive oxygen and nitrogen species take part in the reaction process which yields many intermediate products including aromatic nitro-products. This study concluded that NTP can effectively degrade CBZ in both pure and tap water, but special attention must be paid to changes in the water quality parameters (pH, conductivity, and nitrate/nitrite ions) and the fate of nitro products.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Nitratos/análisis , Nitritos/análisis , Carbamazepina/química , Cloro/química , Benzodiazepinas/análisis , Oxidación-Reducción , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos
2.
Rech Soins Infirm ; 149(2): 78-84, 2022.
Artículo en Francés | MEDLINE | ID: mdl-36241457

RESUMEN

Since its discovery, the concept of vaccination has continued to improve in order to offer better efficacy and tolerance. Local or even diffuse reactions are often reported, but no study reports results on the injection side. We carried out a prospective observational study on the COVID-19 vaccination centers of the Landes regional hospital consortium (GHT) over three weeks. A questionnaire was given after the second injection, and assessed patients' feelings about the first injection. During this period, 2797 patients received their second injection and 2487 responded to the questionnaire, of which 2301 are usable. 81% of vaccinations were performed on the weak arm and 19% on the dominant arm. Local pain/discomfort was reported by 47% of patients on both arms, occurring the same day as the vaccination took place for half of the patients and the next day for the other half, with an average intensity of 3.3. Extensive pain/discomfort was present in 19% of patients, regardless of which arm was injected. The choice of the injected arm does not seem to have influence on pain.


Depuis sa découverte, la pratique de la vaccination s'est améliorée de façon continue afin d'offrir une meilleure efficacité et tolérance. Les réactions locales voire diffuses sont souvent évoquées, mais aucune étude ne rapporte de résultats en fonction du bras choisi pour l'injection. Nous avons réalisé une étude observationnelle prospective aux centres de vaccination COVID-19 du GHT des Landes pendant trois semaines. Un questionnaire était remis après la deuxième injection et évaluait les douleurs et gênes du patient lors de la première injection. Durant cette période, 2 797 patients ont reçu leur deuxième injection, 2 487 ont répondu au questionnaire dont 2 301 sont exploitables. La vaccination a été réalisée à 81 % du côté du bras non dominant et à 19 % du côté du bras dominant. Les douleurs/gênes locales ont été rapportées par 47 % des patients sur les deux bras, leur apparition étant survenue le jour même pour la moitié des personnes et le lendemain pour l'autre moitié, avec une intensité moyenne de 3,3 sur une échelle de 10. Les douleurs/gênes diffuses étaient présentes chez 19 % des personnes, quel que soit le côté. Le choix du bras pour l'injection semble ne pas avoir d'influence sur la survenue de douleurs.


Asunto(s)
Vacunas contra la COVID-19 , COVID-19 , Brazo , COVID-19/epidemiología , COVID-19/prevención & control , Humanos , Dolor/etiología , Dolor/prevención & control , SARS-CoV-2 , Vacunación
3.
Nanotechnology ; 32(37)2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34020428

RESUMEN

Seawater desalination is vital to our modern civilization. Here, we report that the carbon honeycomb (CHC) has an outstanding water permeability and salt rejection in the seawater desalination, as revealed by molecular dynamics simulations. More than 92% of ions are rejected by CHC at applied pressures ranging from 50 to 250 MPa. CHC has a perfect salt rejection at pressures below 150 Mpa. On increasing the applied pressure up to 150 MPa, the salt rejection reduces only to 92%. Pressure, temperature and temperature gradient are noted to play a significant role in modulating the water flux. The water flux increases with pressure and temperature. With the introduction of a temperature gradient of 3.5 K nm-1, the seawater permeability increases by 33% as compared to room temperature. The water permeability of the CHC is greater than other carbon materials and osmosis membranes including graphene (8.7 times) and graphyne (2.1 times). It indicates the significant potential of the CHC for commercial application in water purification.

4.
Nanoscale ; 12(47): 23984-23994, 2020 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-33094784

RESUMEN

Graphene is a key material of interest for the modification of physicochemical surface properties. However, its flat surface is a limitation for applications requiring a high specific surface area. This restriction may be overcome by integrating 2D materials in a 3D structure. Here, a strategy for the controlled synthesis of Graphene-Mesoporous Germanium (Gr-MP-Ge) nanomaterials is presented. Bipolar electrochemical etching and chemical vapor infiltration were employed, respectively, for the nanostructuration of Ge substrate and subsequent 3D nanographene coating. While Raman spectroscopy reveals a tunable domain size of nanographene with the treatment temperature, transmission electron microscopy data confirm that the crystallinity of Gr-MP-Ge is preserved. X-ray photoelectron spectroscopy indicates the non-covalent bonding of carbon to Ge for Gr-MP-Ge. State-of-the-art molecular dynamics modeling provides a deeper understanding of the synthesis process through the presence of radicals. The successful synthesis of these nanomaterials offers the integration of nanographene into a 3D structure with a high aspect ratio and light weight, thereby opening avenues to a variety of applications for this versatile nanomaterial.

5.
Nanomaterials (Basel) ; 10(2)2020 Feb 18.
Artículo en Inglés | MEDLINE | ID: mdl-32085382

RESUMEN

Carbon honeycomb has a nanoporous structure with good mechanical properties including strength. Here we investigate the adsorption and diffusion of hydrogen in carbon honeycomb via grand canonical Monte Carlo simulations and molecular dynamics simulations including strength. Based on the adsorption simulations, molecular dynamics simulations are employed to study the effect of pressure and temperature for the adsorption and diffusion of hydrogen. To study the effect of pressure, we select the 0.1, 1, 5, 10, 15, and 20 bars. Meanwhile, we have studied the hydrogen storage capacities of the carbon honeycomb at 77 K, 153 K, 193 K, 253 K and 298 K. A high hydrogen adsorption of 4.36 wt.% is achieved at 77 K and 20 bars. The excellent mechanical properties of carbon honeycomb and its unique three-dimensional honeycomb microporous structure provide a strong guarantee for its application in practical engineering fields.

6.
ChemSusChem ; 6(7): 1168-71, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23765573

RESUMEN

Plasma increases activity: A one-step synthesis of Pt-C nanowire composites using a plasma co-deposition method is reported. Electrodes with a very low Pt loading can be obtained. Pt particles with sizes ranging from 1 to 2 nm are decorating the columnar carbon nanostructures because of strong interactions. The composite microstructure is responsible for a very high metal utilization rate as exemplified by reactions occurring in fuel cell electrodes.


Asunto(s)
Carbono/química , Nanocables/química , Gases em Plasma/química , Platino (Metal)/química , Técnicas de Química Sintética , Electroquímica , Temperatura
7.
Phys Rev Lett ; 102(4): 045901, 2009 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-19257443

RESUMEN

Constant flux atom deposition into a porous medium is shown to generate a dense overlayer and a diffusion profile. Scaling analysis shows that the overlayer acts as a dynamic control for atomic diffusion in the porous substrate. This is modeled by generalizing the porous diffusion equation with a time-dependent diffusion coefficient equivalent to a nonlinear rescaling of time.

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