283 research outputs found
A propos d’un rare cas de tumeur Rhabdoïde Teratoïde atypique du systeme nerveux central chez une femme enceinte
Les tumeurs rhabdoïdes tératoïdes atypiques du système nerveux central sont des tumeurs pédiatriques rares et de mauvais pronostic. La littérature rapporte une dizaine de cas chez l'adulte dont deux survenus au cours d'une grossesse. Nous rapportons dans ce travail, le cas d'une femme de 25 ans, enceinte de 14 semaines d'aménorrhée, qui a été opérée pour une tumeur rhabdoïde tératoïde atypique de la fosse cérébrale postérieure. Un complément thérapeutique a été discuté chez la patiente après interruption thérapeutique de grossesse, mais la patiente fut décédée avant de démarrer le traitement adjuvant. Nous décrivons brièvement les caractéristiques des tumeurs rhabdoïdes, et les particularités de sa prise en charge chez l'adulte
Volatile Constituents And Antimicrobial Activity Of Lavandula Stoechas L. Oil From Tunisia
International audienceAn oil obtained from the dried leaves of Lavandula stoechas L. in 0.77% yield was analyzed by capillary GC and GUMS. Fenchone (68.2%) and camphor (11.2%) were the main components of the 28 identified molecules. This oil has been tested for antimicrobial activity against six bacteria, and two fungi. The results showed that this oil was active against all of the tested strains; Staphylococcus aureus was the more sensitive strain
Mechanisms by which statins protect endothelial cells from radiation-induced injury in the carotid artery
BackgroundThe incidental use of statins during radiation therapy has been associated with a reduced long-term risk of developing atherosclerotic cardiovascular disease. However, the mechanisms by which statins protect the vasculature from irradiation injury remain poorly understood.ObjectivesIdentify the mechanisms by which the hydrophilic and lipophilic statins pravastatin and atorvastatin preserve endothelial function after irradiation.MethodsCultured human coronary and umbilical vein endothelial cells irradiated with 4 Gy and mice subjected to 12 Gy head-and-neck irradiation were pretreated with statins and tested for endothelial dysfunction, nitric oxide production, oxidative stress, and various mitochondrial phenotypes at 24 and 240 h after irradiation.ResultsBoth pravastatin (hydrophilic) and atorvastatin (lipophilic) were sufficient to prevent the loss of endothelium-dependent relaxation of arteries after head-and-neck irradiation, preserve the production of nitric oxide by endothelial cells, and suppress the cytosolic reactive oxidative stress associated with irradiation. However, only pravastatin inhibited irradiation-induced production of mitochondrial superoxide; damage to the mitochondrial DNA; loss of electron transport chain activity; and expression of inflammatory markers.ConclusionsOur findings reveal some mechanistic underpinnings of the vasoprotective effects of statins after irradiation. Whereas both pravastatin and atorvastatin can shield from endothelial dysfunction after irradiation, pravastatin additionally suppresses mitochondrial injury and inflammatory responses involving mitochondria. Clinical follow-up studies will be necessary to determine whether hydrophilic statins are more effective than their lipophilic counterparts in reducing the risk of cardiovascular disease in patients undergoing radiation therapy
High-isolation antenna array using SIW and realized with a graphene layer for sub-terahertz wireless applications
This paper presents the results of a study on developing an effective technique to increase the performance characteristics of antenna arrays for sub-THz integrated circuit applications. This is essential to compensate the limited power available from sub-THz sources. Although conventional array structures can provide a solution to enhance the radiation-gain performance however in the case of small-sized array structures the radiation properties can be adversely affected by mutual coupling that exists between the radiating elements. It is demonstrated here the effectiveness of using SIW technology to suppress surface wave propagations and near field mutual coupling effects. Prototype of 2x3 antenna arrays were designed and constructed on a polyimide dielectric substrate with thickness of 125 mu m for operation across 0.19-0.20 THz. The dimensions of the array were 20x13.5x0.125 mm(3). Metallization of the antenna was coated with 500 nm layer of Graphene. With the proposed technique the isolation between the radiating elements was improved on average by 22.5 dB compared to a reference array antenna with no SIW isolation. The performance of the array was enhanced by transforming the patch to exhibit metamaterial characteristics. This was achieved by embedding the patch antennas in the array with sub-wavelength slots. Compared to the reference array the metamaterial inspired structure exhibits improvement in isolation, radiation gain and efficiency on average by 28 dB, 6.3 dBi, and 34%, respectively. These results show the viability of proposed approach in developing antenna arrays for application in sub-THz integrated circuits
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