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21.
Carlos E.M. Guarido Deborah V. Cesar Mariana M.V.M. Souza Martin Schmal 《Catalysis Today》2009,142(3-4):252
Ethanol reforming and partial oxidation were studied on Cu/Nb2O5 and Ni/Al2O3 catalysts. Compared to the Ni/Al2O3 catalyst, the Cu/Nb2O5 catalyst presents conversion as high as Ni/Al2O3 catalyst, however, for the same level of formation of hydrogen it occurs at much lower temperature on the Cu/Nb2O5 catalyst, 200 °C lower than for the Ni/Al2O3 catalyst, with remarkable little formation of CO, which can be attributed to the strong interaction between copper and niobia. Temperature-programmed desorption (TPD-ethanol) and surface reactions (TPSR) of partial oxidation of ethanol showed formation of ethylene, acetaldehyde, ethane and mainly H2 and CO2 besides little methane. DRIFTS results are in accordance with TPD analysis and the formation of acetate species at room temperature suggests reactivity of the surface and its oxidative dehydrogenation capacity. The adsorption of ethanol gives rise to ethoxide species, which form acetate and acetaldehyde that can be oxidized to CO2 via carbonate. A comparison with reported results for Cu/Al2O3 this catalyst is promising, yielding high level of H2 with little CO production during reforming and partial oxidation reaction. The maximum H2 formation for the partial oxidation of ethanol was 41% at ratio (O2/Et) 0.8, increasing to 50% at ratio 1.5. The H2/CO is around 10 for the partial oxidation and 7 for steam reforming, which is excellent, compared to the Ni/Al2O3 catalyst with a factor 4–8 lower. 相似文献
22.
This contribution provides insight on the elimination of heavy metals from water resources using magnetic separation. Nanocomposites based on magnetite and chitosan were prepared. An exhaustive characterization of the magnetic adsorbents was developed. Adsorption assays were performed in batch using Cu, Zn, Cd, and Cr as model heavy metals. The efficiency of magnetic adsorbents followed the order: Cu > Cd > Zn > Cr, with maximum values of 188, 159, 72, and 46 mg of Me/g of nanocomposite, respectively. Kinetics and mechanistic issues were studied. The magnetic materials were efficient for five to eight cycles using Cu(II),Cd(II), and Cr(VI). 相似文献
23.
Structure–property relationship of sodium deoxycholate based poly(ester ether)urethane ionomers for biomedical applications 下载免费PDF全文
Daniela Filip Doina Macocinschi Stelian Vlad Gabriela Lisa Mariana Cristea Mirela F. Zaltariov 《应用聚合物科学杂志》2016,133(4)
New sodium deoxycholate based poly(ester ether)urethane ionomers were prepared for the development of biomedical materials. A structure–property relationship in the tested biomaterials was established by cross‐examination of the dynamic mechanical and dielectric properties, attenuated total reflection–Fourier transform infrared investigation, thermogravimetric analysis, and surface morphology characterization. A stronger ionic interaction and solvation capacity of the ions and a higher ionic conductivity were manifested in the case of poly(ethylene oxide)‐rich segments than for poly(propylene oxide)‐rich segments in these polyurethane ionomers. The molecular and ionic interactions of the bile‐salt moiety with different polyether cosoft segments influenced chain packing and conformation, supramolecular organization, and the resulting surface morphological microstructures of the polyurethane biomembranes. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42921. 相似文献
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Razvan Ghiarasim Natalia Simionescu Adina Coroaba Cristina M. Uritu Narcisa Laura Marangoci Sorin-Alexandru Ibanescu Mariana Pinteala 《International journal of molecular sciences》2022,23(1)
Targeted nanocarriers could reach new levels of drug delivery, bringing new tools for personalized medicine. It is known that cancer cells overexpress folate receptors on the cell surface compared to healthy cells, which could be used to create new nanocarriers with specific targeting moiety. In addition, magnetic nanoparticles can be guided under the influence of an external magnetic field in different areas of the body, allowing their precise localization. The main purpose of this paper was to decorate the surface of magnetic nanoparticles with poly(2-hydroxyethyl methacrylate) (PHEMA) by surface-initiated atomic transfer radical polymerization (SI-ATRP) followed by covalent bonding of folic acid to side groups of the polymer to create a high specificity magnetic nanocarrier with increased internalization capacity in tumor cells. The biocompatibility of the nanocarriers was demonstrated by testing them on the NHDF cell line and folate-dependent internalization capacity was tested on three tumor cell lines: MCF-7, HeLa and HepG2. It has also been shown that a higher concentration of folic acid covalently bound to the polymer leads to a higher internalization in tumor cells compared to healthy cells. Last but not least, magnetic resonance imaging was used to highlight the magnetic properties of the functionalized nanoparticles obtained. 相似文献
26.
Mariana S. Araujo Antonio C. Silva José F. Bartolomé Sonia Mello-Castanho 《Journal of the American Ceramic Society》2020,103(6):3620-3630
The present research exposes the influence of 2 mol% of Al2O3 and 2 mol% SrO in 45S5 Bioglass®-based compositions. Four compositions were produced to elucidate the difference in how both oxides influence structure and thermal behavior separately and their synergy when together. Thermal properties, crystallization tendency, and sintering behavior was evaluated by differential scanning calorimetry, hot stage microscopy, and dilatometry. Changes of medium-range structures were characterized by Qn distribution of Raman spectroscopy and evaluation of 31P, 27Al, 23Na, and 29Si environment obtained by magic angle spinning nuclear magnetic resonance. Despite Qn distribution was predominantly Q2 in all samples, the composition criteria used enabled improved processing and stabilibity characteristics. The addition of Al2O3 and SrO promoted larger sinterability parameter (Sc) which indicates better sintering behavior, the glass stability against crystallization doubled (KH) compared to 45S5 and the processing window enlarged from 106 to 171. 相似文献
27.
Maria Sofia Vieira-Rocha Pilar Rodriguez-Rodriguez Mariana Ferreira-Duarte Miguel Faria Joana Beatriz Sousa Manuela Morato Silvia Magdalena Arribas Carmen Diniz 《International journal of molecular sciences》2022,23(3)
Fetal stress is known to increase susceptibility to cardiometabolic diseases and hypertension in adult age in a process known as fetal programming. This study investigated the relationship between vascular RAS, oxidative damage and remodeling in fetal programming. Six-month old Sprague-Dawley offspring from mothers that were fed ad libitum (CONTROL) or with 50% intake during the second half of gestation (maternal undernutrition, MUN) were used. qPCR or immunohistochemistry were used to obtain the expression of receptors and enzymes. Plasma levels of carbonyls were measured by spectrophotometry. In mesenteric arteries from MUN rats we detected an upregulation of ACE, ACE2, AT1 receptors and NADPH oxidase, and lower expression of AT2, Mas and MrgD receptors compared to CONTROL. Systolic and diastolic blood pressure and plasma levels of carbonyls were higher in MUN than in CONTROL. Vascular morphology evidenced an increased media/lumen ratio and adventitia/lumen ratio, and more connective tissue in MUN compared to CONTROL. In conclusion, fetal undernutrition indices RAS alterations and oxidative damage which may contribute to the remodeling of mesenteric arteries, and increase the risk of adverse cardiovascular events and hypertension. 相似文献
28.
Dr. Lilia Clima Bogdan Florin Craciun Dr. Andrea Angeli Andrea Petreni Alessandro Bonardi Dr. Alessio Nocentini Dr. Fabrizio Carta Prof. Paola Gratteri Prof. Mariana Pinteala Prof. Claudiu T. Supuran 《ChemMedChem》2020,15(21):2052-2057
We report novel molecules incorporating the nontoxic squalene scaffold and different carbonic anhydrase inhibitors (CAIs). Potent inhibitory action, in the low-nanomolar range, was detected against isoforms hCA II for sulfonamide derivatives, which proved to be selective against this isoform over the tumor-associate hCA IX and XII isoforms. On the other hand, coumarin derivatives showed weak potency but high selectivity against the tumor-associated isoform CA IX. These compounds are interesting candidates for preclinical evaluation in glaucoma or various tumors in which the two enzymes are involved. In addition, an in silico study of inhibitor-bound hCA II revealed extensive interactions with the hydrophobic pocket of the active site and provided molecular insights into the binding properties of these new inhibitors. 相似文献
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Noala Vicensoto Moreira Milhan William Chiappim Aline da Graa Sampaio Mariana Raquel da Cruz Vegian Rodrigo Svio Pessoa Cristiane Yumi Koga-Ito 《International journal of molecular sciences》2022,23(8)
The activation of water by non-thermal plasma creates a liquid with active constituents referred to as plasma-activated water (PAW). Due to its active constituents, PAW may play an important role in different fields, such as agriculture, the food industry and healthcare. Plasma liquid technology has received attention in recent years due to its versatility and good potential, mainly focused on different health care purposes. This interest has extended to dentistry, since the use of a plasma–liquid technology could bring clinical advantages, compared to direct application of non-thermal atmospheric pressure plasmas (NTAPPs). The aim of this paper is to discuss the applicability of PAW in different areas of dentistry, according to the published literature about NTAPPs and plasma–liquid technology. The direct and indirect application of NTAPPs are presented in the introduction. Posteriorly, the main reactors for generating PAW and its active constituents with a role in biomedical applications are specified, followed by a section that discusses, in detail, the use of PAW as a tool for different oral diseases. 相似文献