Search results for "urea"
showing 8 items of 888 documents
Voltammetric Detection of Lead(II) Using Amide-Cyclam- Functionalized Silica-Modified Carbon Paste Electrodes
2009
2-(4,8,11-Triscarbamoylmethyl-1,4,8,11-tetraazacyclotetradec-1-yl)acetamide (TETAM) derivatives bearing 1, 2, or 4 silylated arms have been synthesized and grafted to the surface of silica gel and ordered mesoporous silica samples. The resulting organic-inorganic hybrids have been incorporated into carbon paste electrodes and applied to the preconcentration electroanalysis of Pb(II). The attractive recognition properties of these cyclam derivatives functionalized with amide pendent groups toward Pb(II) species and the highly porous structure of the adsorbents can be exploited for the selective and sensitive detection of the target analyte. Various parameters affecting the preconcentration a…
Exploring drivers for Italian university students’ mobility: first evidence from AlmaLaurea data.
2021
This article is part of a national Project aimed at studying Italian university students’ mobility. The novelty proposed here lies in the use, for the first time, of individual data from the census surveys that the Alma Laurea consortium conducts on all Italian graduates. The advantage of this data consists of information that was previously unavailable. For example, information about the socio-economic conditions of the students’ parents, satisfaction with the Bachelor’s degree course and university services, and employment status recorded 1, 3, and 5 years after graduation. Here we report the first analyses conducted on the data relating to the University of Palermo Bachelors who enrolled…
Determinación de herbicidas derivados de la urea en aguas y vegetales
2002
La Legislación de la Unión Europea establece límites muy rigurosos para la presencia de residuos de herbicidas derivados de la urea en aguas y en alimentos. Muchos de estos herbicidas son termolábiles y se descomponen durante el análisis por cromatografía de gases (CG), si bien se pueden determinar de manera indirecta a partir de los productos de degradación.El presente trabajo se propone como objetivos; estudiar el comportamiento de herbicidas derivados de la urea en CG con columnas capilares, evaluar su cuantificación en base a sus productos de degradación térmica, poner a punto un nuevo método de análisis en aguas y vegetales basado en la MEFS y la determinación por CG y aplicarlo al aná…
Multimetallic Oxynitrides Nanoparticles for a New Generation of Photocatalysts
2019
A versatile synthetic strategy for the preparation of multimetallic oxynitrides has been designed and here exemplarily discussed considering the preparation of nanoscaled zinc-gallium oxynitrides and zinc-gallium-indium oxynitrides, two important photocatalysts of new generation, which proved to be active in key energy related processes from pollutant decomposition to overall water splitting. The synthesis presented here allows the preparation of small nanoparticles (less than 20 nm in average diameter), well-defined in size and shape, yet highly crystalline and with the highest surface area reported so far (up to 80 m2 g-1 ). X-ray diffraction studies show that the final material is not a…
Sviluppo del metodo urea glass-route per la preparazione di nanoparticelle di Ce:YAG
2015
I materiali a base di yttrium aluminum garnet (YAG) drogato con ioni lantanidi hanno suscitato negli ultimi anni notevole interesse per le loro importanti applicazioni tecnologiche nel campo dei dispositivi optoelettronici quali laser, LED, display e scintillatori per i raggi X. In particolare, lo YAG drogato con ioni Ce(III) è utilizzato, in combinazione ai semiconduttori di nitruro di gallio (GaN) o indio e gallio (GaInN), per la realizzazione di LED a luce bianca1. Il miglioramento delle performance di questi dispositivi è vincolato all’ottimizzazione, in termini di proprietà, dei materiali che lo compongono. Una delle strategie consiste nel preparare nanoparticelle (np) di Ce:YAG con di…
Dual Enzyme-Triggered Controlled Release on Capped Nanometric Silica Mesoporous Supports
2012
The development of nanoscopic hybrid materials equipped with “molecular gates” showing the ability of releasing target entrapped guests upon the application of an external trigger has attracted great attention and has been extensively explored during recent years.1 These nanodevices are composed of two subunits, namely, a suitable support and certain capping entities grafted on the surface of the scaffolding.2 The support is used as a suitable reservoir in which certain chemicals can be stored whereas the molecules grafted in the outer surface act as a “gate” and can control the release of the entrapped molecules at will. Both components are carefully selected and arranged in order to achie…
Development of an immunochromatographic assay based on carbon nanoparticles for the determination of the phytoregulator forchlorfenuron
2013
Rapid analytical methods enabling the determination of diverse targets are essential in a number of research areas, from clinical diagnostics to feed and food quality and safety. Herein, the development of a quantitative immunochromatographic assay for the detection of the synthetic phytoregulator forchlorfenuron (CPPU) is described. The competitive lateral flow immunoassay (LFIA) was based on the immobilization onto a nitrocellulose membrane of an ovalbumin-CPPU conjugate (test line) and on the use of an immunodetection ligand consisting of carbon nanoparticles labeled with an anti-CPPU monoclonal antibody through interaction with a secondary antibody. The presence of CPPU in horticultural…
Ģimenes ārstu nozīmētās H.Pylori eradikācijas shēmas, to atbilstība vadlīnijām, indikācijām un efektivitāte
2015
H.pylori ir patogēna baktērija, kas kolonizē kuņģa gļotādu. H.pylori eradikācija potenciāli var pasargāt no kuņģa vēža. Māstrihtas vadlīnijas IV nosaka, H.pylori eradikācijas terapiju veikt pacientiem ar noteiktām indikācijām. Pētījumā analizēta ģimenes ārstu nozīmēto eradikācijas terapijas kursu efektivitāte un tā atbilstība vadlīnijām. Analīzē izmantoti dati par 412 pacientiem, kuri ieradušies uz eradikācijas terapijas kursa kontroli. Analīze veikta gan pēc pirmreizēja, gan atkārtota eradikācijas kursa. Kopumā tika analizēti 427 eradikācijas terapijas kursi, 224 no tiem, bija ģimenes ārstu nozīmēti. Sekmīga ģimenes ārstu nozīmētā terapija bija 170 (75.9%) gadījumos, pirmreizēji nozīmētas …