Supramolecular Usefulness Of Hexamethylenetetramine

U ovom radu prikazan je način rada i implementacija sustav za očitavanje rukom pisanih slova koji je projektiran tako da na svoj ulaz primi sliku slova, a na svom izlazu vrati prepoznato slovo. Primljena slika se obrađuje te se iz nje izdvaja kostur slova. Izvučeni kostur se zatim skalira na uniformne dimenzije i gradi se vektor značajki korištenjem dijagonalne i horizontalne projekcije te broja točaka presjecište i broja krajnjih točaka. Tako dobiveni vektor značajki se dovodi na ulaze neuronske mreže koja je učena algoritmom propagacije pogreške unatrag uz dodatak momenta inercije. Skup za učenje neuronske mreže se sastojao od 4480 velikih i malih tiskanih slova hrvatske i engleske abecede.This thesis describes the algorithm and implementation details of system for handwritten letter recognition. On its input, it receives letter image, and returns recognized letter as output. First, the input image is preprocessed and letter skeleton is extracted. After that, letter skeleton is scaled to uniform dimension and feature vector is extracted using diagonal and horizontal projection and number of cross-points and end-points. Extracted feature vector is input for neural network which is trained using backpropagation algorithm with momentum. Training set is consisted of 4480 large and small handwritten letters of Croatian and English alphabet

The role of phosphodiesterase 12 (PDE12) as a negative regulator of the innate immune response and the discovery of antiviral inhibitors

2',5'-Oligoadenylate synthetase (OAS) enzymes and RNase-L constitute a major effector arm of interferon (IFN)-mediated antiviral defense. OAS produces a unique oligonucleotide second messenger, 2',5'-oligoadenylate (2-5A), that binds and activates RNase-L. This pathway is down-regulated by virus- and host-encoded enzymes that degrade 2-5A. Phosphodiesterase 12 (PDE12) was the first cellular 2-5A- degrading enzyme to be purified and described at a molecular level. Inhibition of PDE12 may up-regulate the OAS/RNase-L pathway in response to viral infection resulting in increased resistance to a variety of viral pathogens. We generated a PDE12-null cell line, HeLaΔPDE12, using transcription activator-like effector nuclease-mediated gene inactivation. This cell line has increased 2-5A levels in response to IFN and poly(I-C), a double-stranded RNA mimic compared with the parental cell line. Moreover, HeLaΔPDE12 cells were resistant to viral pathogens, including encephalomyocarditis virus, human rhinovirus, and respiratory syncytial virus. Based on these results, we used DNA-encoded chemical library screening to identify starting points for inhibitor lead optimization. Compounds derived from this effort raise 2-5A levels and exhibit antiviral activity comparable with the effects observed with PDE12 gene inactivation. The crystal structure of PDE12 complexed with an inhibitor was solved providing insights into the structure-activity relationships of inhibitor potency and selectivity

Bis(1,2-dihydroxy­benzene) hexa­methyl­ene­tetra­mine

The title binary complex, 2C6H6O2·C6H12N4, is constructed from hexa­methyl­ene­tetra­mine, positioned about a twofold symmetry operator, and 1,2-dihydroxy­benzene. Each of the four tertiary amine N atoms participates in O—H⋯N contacts that produce mol­ecular strands that propagate along the c axis

Synthesis of Spiroaminals and Spiroketals with Bimetallic Relay Catalysis

A novel tandem metal relay catalytic system was developed by combining gold-catalyzed cycloisomerization with an early transition-metal-catalyzed inverse-electron-demand hetero-Diels–Alder (IED-HDA) reaction. Various biologically important spiroaminals and spiroketals were obtained with very high efficiency under mild conditions