Search results for "FOT"
showing 10 items of 1161 documents
Tips and turns of bacteriophytochrome photoactivation
2020
Phytochromes are ubiquitous photosensor proteins, which control the growth, reproduction and movement in plants, fungi and bacteria. Phytochromes switch between two photophysical states depending on the light conditions. In analogy to molecular machines, light absorption induces a series of structural changes that are transduced from the bilin chromophore, through the protein, and to the output domains. Recent progress towards understanding this structural mechanism of signal transduction has been manifold. We describe this progress with a focus on bacteriophytochromes. We describe the mechanism along three structural tiers, which are the chromophore-binding pocket, the photosensory module,…
Computational study on hydrolysis of cefotaxime in gas phase and in aqueous solution
2012
We are presenting a theoretical study of the hydrolysis of a β-lactam antibiotic in gas phase and in aqueous solution by means of hybrid quantum mechanics/molecular mechanics potentials. After exploring the potential energy surfaces at semiempirical and density functional theory (DFT) level, potentials of mean force have been computed for the reaction in solution with hybrid PM3/TIP3P calculations and corrections with the B3LYP and M06-2X functionals. Inclusion of the full molecule of the antibiotic, Cefotaxime, in the gas phase molecular model has been demonstrated to be crucial since its carboxylate group can activate a nucleophilic water molecule. Moreover, the flexibility of the substra…
Multiple Decay Mechanisms and 2D-UV Spectroscopic Fingerprints of Singlet Excited Solvated Adenine-Uracil Monophosphate
2016
The decay channels of singlet excited adenine uracil monophosphate (ApU) in water are studied with CASPT2//CASSCF:MM potential energy calculations and simulation of the 2D-UV spectroscopic fingerprints with the aim of elucidating the role of the different electronic states of the stacked conformer in the excited state dynamics. The adenine 1La state can decay without a barrier to a conical intersection with the ground state. In contrast, the adenine 1Lb and uracil S(U) states have minima that are separated from the intersections by sizeable barriers. Depending on the backbone conformation, the CT state can undergo inter-base hydrogen transfer and decay to the ground state through a conical …
Virsmas apstrādes ietekme uz keramikas granulu sorbcijas spēju
2016
Virsmas apstrādes ietekme uz keramikas granulu sorbcijas spēju. Leščinskis O., zinātniskie vadītāji Dr.sc.ing. asoc.prof. Švinka R., Dr.chem., prof. Actiņš A. Maģistra darbs, 56 lappuses, 39 attēli, 12 tabulas, 46 literatūras avoti, 1 pielikums. Latviešu valodā. Literarūras apskatā ir apkopota informācija par māliem, to minerāliem, radiācijas ietekmi uz tiem, kā arī fotokatalītiskiem materiāliem. Darba eksperimentālajā daļā ir pētīta Latvijas Devona perioda Kupravas atradnes mālu keramikas granulu, kas apdedzinātas 800 un 900⁰C temperatūrās ar dažādām izdegošām piedevām, adsorbcijas spēja. Adsorbcija tika noteikta metiloranžam un etiķskābei ūdens šķīdumos. Tika noteikta paātrināto elektronu…
Síntesis y caracterización de nanopartículas de TiO2 y ZrO2 dopadas con cationes de metales de transición. Aplicaciones como nanopigmentos y en fotoc…
2017
En la presente tesis doctoral se pretende por una parte sintetizar en la escala nanométrica pigmentos cerámicos clásicos de uso industrial, como son el pigmento de color amarillo V-ZrO2, y el pigmento de color naranja-amarillo Cr,Sb-TiO2, mediante métodos de síntesis no convencionales. Para llevar a cabo dichas síntesis se van a utilizar dos métodos de síntesis relativamente sencillos y fácilmente reproducibles a escala industrial, como son el método del poliol y el método hidrotermal, los resultados que se obtengan mediante los dos métodos serán comparados y se hará hincapié en sus ventajas e inconvenientes. Las composiciones nominales estudiadas serán en el caso del VxZr1-xO2 valores 0 ≤ …
Kadmija sulfīda nanovadu virsmas pasivācija vides apstākļu izraisītas degradācijas samazināšanai
2021
Kadmija sulfīda nanovadu virsmas pasivācija vides apstākļu izraisītas degradācijas samazināšanai. Dipāne L., kursa darba vadītājs Dr. phys. Butanovs E. (LU CFI). Bakalaura darbs, 31 lappuse, 21 attēli, 3 tabulas, 30 literatūras avoti, 1. pielikums. Latviešu valodā. Darbā veikta CdS nanovadu sintēze ar tvaiks-šīdums-cietviela metodi un plānu metālu oksīdu pārklājumu veidošana uz to virsmas ar atomslāņu depozīcijas (ALD) metodi. Iegūtās nanostruktūras tika raksturotas, izmantojot skenējošo elektronu mikroskopu (SEM), transmisijas elektronu mikroskopu (TEM), enerģētiski dispersīvo rentgenstaru spektroskopiju (EDX) un rentgenstru difrakciju (XRD). Tika veikta divkontaktu ierīču izveidošana un v…
NHC-Based Iron Sensitizers for DSSCs
2018
International audience; Nanostructured dye-sensitized solar cells (DSSCs) are promising photovoltaic devices because of their low cost and transparency. Ruthenium polypyridine complexes have long been considered as lead sensitizers for DSSCs, allowing them to reach up to 11% conversion efficiency. However, ruthenium suffers from serious drawbacks potentially limiting its widespread applicability, mainly related to its potential toxicity and scarcity. This has motivated continuous research efforts to develop valuable alternatives from cheap earth-abundant metals, and among them, iron is particularly attractive. Making iron complexes applicable in DSSCs is highly challenging due to an ultrafa…
Randomized Comparative Trial with Ceftizoxime and Cefotaxime in Urinary Tract Infections
1984
Ceftizoxime, a new, semisynthetic, beta-lactamase-resistant cephalosporin, is not metabolized in man and is excreted almost entirely as the original active compound in the urine. The efficacy and safety of ceftizoxime were assessed in 80 patients with acute and chronic urinary infections, with and without associated pathological conditions, in comparison with cefotaxime. Two dosage schedules, 1 g or 0.5 g every 12 h, i.v. or i.m. for 10 days, were adopted according to the severity of each case and to separate randomization tables for each schedule; causal agents were all sensitive to both drugs in vitro. The overall results were excellent. Safety was excellent in almost all cases. In this t…
The relationship between body and screen in Studio Azzurro’s performances since the 1980s until today
2018
Studio Azzurro is an Italian group that has been working with different performative languages since the 1980s: video installations, theater, video art, cinema, interactive installations, interactive museums. In all these artistic experiences Studio Azzurro has never worked using the languages handed down by tradition, but has always experimented by mixing them with new technologies. The work they have conducted in theater is particular, because the use of new technologies has transformed the concept of theater and has opened the way for the development of new performative forms such as digital or technological theater. In what follows, we will study the relationship between body and screen…
Search for the dark photon in π0 decays
2015
A sample of $1.69\times 10^7$ fully reconstructed $\pi^0\to\gamma e^+e^-$ decay candidates collected by the NA48/2 experiment at CERN in 2003--2004 is analysed to search for the dark photon ($A'$) production in the $\pi^0\to\gamma A'$ decay followed by the prompt $A'\to e^+e^-$ decay. No signal is observed, and an exclusion region in the plane of the dark photon mass $m_{A'}$ and mixing parameter $\varepsilon^2$ is established. The obtained upper limits on $\varepsilon^2$ are more stringent than the previous limits in the mass range $9~{\rm MeV}/c^2<m_{A'}<70~{\rm MeV}/c^2$. The NA48/2 sensitivity to the dark photon production in the $K^\pm\to\pi^\pm A'$ decay is also evaluated.