Primjena fizikalnih i kemijskih metoda u uklanjanju mikotoksina iz hrane i hrane za životinje

Mikotoksini su sekundarni metaboliti plijesni koji predstavljaju značajan problem u području sigurnosti hrane te predstavljaju rizik za zdravlje te dobrobit ljudi i životinja. Učinkovitost metoda uklanjanja mikotoksina iz hrane i hrane za životinje, primarno žitarica kao najviše kontaminirane grupe hrane, ovisi o brojnim parametrima, od kojih su vrlo značajni svojstva onečišćenog materijala, odnosno njegov sastav, primarno sadržaj vode, te razina onečišćenja. Ovaj rad daje pregled fizikalnih i kemijskih metoda koje se manje ili više učinkovito mogu koristiti u tretmanu različitih vrsta hrane i hrane za životinje u cilju redukcije odnosno uklanjanja mikotoksina. Uklanjanje mikotoksina fizikalnim metodama uključuje njihovu ekstrakciju pomoću otapala, adsorpciju te toplinsku inaktivaciju ili inaktivaciju ozračivanjem. Najznačajnije metode su sortiranje po boji i gustoći, ljuštenje i mljevenje, flotacija, blanširanje, prženje, a u posljednje vrijeme vrlo značajna je primjena gama zračenja te hladne plazme. Uporabom kemijskih metoda koje podrazumijevaju primjenu kemikalija dolazi do konverzije mikotoksina u druge manje toksične spojeve, npr. kiseline, lužine, oksidanse, bisulfite i plinove, no moguća je konverzija i u toksičnije spojeve, što je još uvijek predmet brojnih istraživanja. Za razliku od fizikalnih metoda, kemijske metode uklanjanja mikotoksina u načelu se smatraju nepraktičnim i nepoželjnim, zbog uvjeta provedbe, stvaranja toksičnih ostataka te negativnog utjecaja na nutritivna, senzorska i funkcionalna svojstva proizvoda

A Habitable Fluvio-Lacustrine Environment at Yellowknife Bay, Gale Crater, Mars

The Curiosity rover discovered fine-grained sedimentary rocks, inferred to represent an ancient lake, preserve evidence of an environment that would have been suited to support a Martian biosphere founded on chemolithoautotrophy. This aqueous environment was characterized by neutral pH, low salinity, and variable redox states of both iron and sulfur species. C, H, O, S, N, and P were measured directly as key biogenic elements, and by inference N and P are assumed to have been available. The environment likely had a minimum duration of hundreds to tens of thousands of years. These results highlight the biological viability of fluvial-lacustrine environments in the post-Noachian history of Mars

Strong-coupling charge density wave in monolayer TiSe2

We study the 2 × 2 charge density wave (CDW) in epitaxially-grown monolayer TiSe2. Our temperature-dependent angle-resolved photoemission spectroscopy measurements indicate a strong-coupling instability, but reveal how not all states couple equally to the symmetry-breaking distortion, with an electron pocket persisting to low temperature as a non-bonding state. We further show how the CDW order can be suppressed by a modest doping of around 0.06(2) electrons per Ti. Our results provide an opportunity for quantitative comparison with a realistic tight-binding model, which emphasises a crucial role of structural aspects of the phase transition in understanding the hybridisation in the ground state. Together, our work provides a comprehensive understanding of the phenomenology of the CDW in TiSe2 in the 2D limit

A WiMAX-based implementation of network MIMO for indoor wireless systems

It is well known that multiple-input multiple-output (MIMO) techniques can bring numerous benefits, such as higher spectral efficiency, to point-to-point wireless links. More recently, there has been interest in extending MIMO concepts tomultiuser wireless systems. Our focus in this paper is on network MIMO, a family of techniques whereby each end user in a wireless access network is served through several access points within its range of influence. By tightly coordinating the transmission and reception of signals at multiple access points, network MIMO can transcend the limits on spectral efficiency imposed by cochannel interference. Taking prior information-theoretic analyses of networkMIMO to the next level, we quantify the spectral efficiency gains obtainable under realistic propagation and operational conditions in a typical indoor deployment. Our study relies on detailed simulations and, for specificity, is conducted largely within the physical-layer framework of the IEEE 802.16e Mobile WiMAX system. Furthermore,/nto facilitate the coordination between access points, we assume that a high-capacity local area network, such as Gigabit Ethernet,/nconnects all the access points. Our results confirm that network MIMO stands to provide a multiple-fold increase in spectral/nefficiency under these conditions