Substrate temperature influenced ZrO2 films for MOS devices

The effect of substrate temperature on the direct current magnetron-sputtered zirconium oxide (ZrO₂) dielectric films was investigated. Stoichiometric of the ZrO₂ thin films was obtained at an oxygen partial pressure of 4.0 × 10⁻² Pa. X-ray diffraction studies revealed that the crystallite size in the layer was increased from 4.8 to 16.1 nm with increase of substrate temperature from 303 to 673 K. Metal-oxide-semiconductor devices were fabricated on ZrO₂/Si stacks with Al gate electrode. The dielectric properties of ZrO₂ layer and interface quality at ZrO₂/Si were significantly influenced by the substrate temperature. The dielectric constant increased from 15 to 25, and the leakage current density decreased from 0.12 × 10⁻⁷ to 0.64 × 10⁻⁹ A cm⁻² with the increase of substrate temperature from 303 to 673 K.     

Optimality conditions for a unified vector optimization problem with not necessarily preordering relations

This paper studies a general vector optimization problem which encompasses those related to efficiency, weak efficiency, strict efficiency, proper efficiency and approximate efficiency among others involving non necessarily preordering relations. Based on existing results about complete characterization by scalarization of the solution set obtained by the same authors, several properties of (generalized) convexity and lower semicontinuity of the composition of the scalarizing functional and the objective vector function are studied. Finally, some optimality conditions are presented through subdifferentials in the convex and nonconvex case.     

Investigation on Optical and Biological Properties of 2-(4-Dimethylaminophenyl)benzothiazole Based Cycloplatinated Complexes

The optical and biological properties of 2-(4-dimethylaminophenyl)benzothiazole cycloplatinated complexes featuring bioactive ligands ([{Pt(Me₂N-pbt)(C₆F₅)}L] [L=Me₂N-pbtH 1 , p-dpbH (4-(diphenylphosphino)benzoic acid) 2 , o-dpbH (2-(diphenylphosphino)benzoic acid) 3 ), [Pt(Me₂N-pbt)(o-dpb)] 4 , [{Pt(Me₂N-pbt)(C₆F₅)}₂(μ-PR_nP)] [PR₄P=O(CH₂CH₂OC(O)C₆H₄PPh₂)₂ 5 , PR₁₂P=O{(CH₂CH₂O)₃C(O)C₆H₄PPh₂}₂ 6 ] are presented. Complexes 1 – 6 display ¹ILCT and metal-perturbed ³ILCT dual emissions. The ratio between both bands is excitation dependent, accomplishing warm-white emissions for 2 , 5 and 6 . The phosphorescent emission is lost in aerated solutions owing to photoinduced electron transfer to ³O₂ and the formation of ¹O₂, as confirmed in complexes 2 and 4 . They also exhibit photoinduced phosphorescence enhancement in non-degassed DMSO due to local oxidation of DMSO by sensitized ¹O₂, which causes a local degassing. Me₂N-pbtH and the complexes specifically accumulate in the Golgi apparatus, although only 2 , 3 and 6 were active against A549 and HeLa cancer cell lines, 6 being highly selective in respect to nontumoral cells. The potential photodynamic property of these complexes was demonstrated with complex 4 .     

Enzymatic Preparation of Bioactive Peptides Exhibiting ACE Inhibitory Activity from Soybean and Velvet Bean: A Systematic Review

The Angiotensin-I-converting enzyme (ACE) is a peptidase with a significant role in the regulation of blood pressure. Within this work, a systematic review on the enzymatic preparation of Angiotensin-I-Converting Enzyme inhibitory (ACEi) peptides is presented. The systematic review is conducted by following PRISMA guidelines. Soybeans and velvet beans are known to have high protein contents that make them suitable as sources of parent proteins for the production of ACEi peptides. Endopeptidase is commonly used in the preparation of soybean-based ACEi peptides, whereas for velvet bean, a combination of both endo- and exopeptidase is frequently used. Soybean glycinin is the preferred substrate for the preparation of ACEi peptides. It contains proline as one of its major amino acids, which exhibits a potent significance in inhibiting ACE. The best enzymatic treatments for producing ACEi peptides from soybean are as follows: proteolytic activity by Protease P (Amano-P from Aspergillus sp.), a temperature of 37 °C, a reaction time of 18 h, pH 8.2, and an E/S ratio of 2%. On the other hand, the best enzymatic conditions for producing peptide hydrolysates with high ACEi activity are through sequential hydrolytic activity by the combination of pepsin-pancreatic, an E/S ratio for each enzyme is 10%, the temperature and reaction time for each proteolysis are 37 °C and 0.74 h, respectively, pH for pepsin is 2.0, whereas for pancreatin it is 7.0. As an underutilized pulse, the studies on the enzymatic hydrolysis of velvet bean proteins in producing ACEi peptides are limited. Conclusively, the activity of soybean-based ACEi peptides is found to depend on their molecular sizes, the amino acid residues, and positions. Hydrophobic amino acids with nonpolar side chains, positively charged, branched, and cyclic or aromatic residues are generally preferred for ACEi peptides.     

13C NMR spectroscopy of copoly(arylenephthalide) derivatives with diphenyloxide and terphenyl fragments in the main chain

¹H and ¹³С NMR spectral assignments have been provided for low‐molecular reference monomers, poly(diphenyleneoxidephthalide) and periodic copoly(arylenephthalide) derivatives such as AB, ABB, and ABBB (where A = terphenylenephthalide and B = diphenyleneoxidephthalide) using ¹H‐¹H COSY, ¹H‐¹³C HSQC and HMBC NMR techniques. Distinctive ¹³C NMR chemical shifts of a main chain have been observed containing fragments of similar structures and lateral phthalate groups being part of various diads. Copyright © 2013 John Wiley & Sons, Ltd.     

Spirolactams as conformationally restricted pseudopeptides: synthesis and conformational analysis

The synthesis of 1-(tert-butoxycarbonyl)-7-[1-(tert-butoxycarbonyl)-3-methylbutyl]-6-oxo-1,7-diazaspiro[4.5]decanes (S,S)-1a and (S,R)-1b is described. Derivatives 17a,b and 19a are prepared for use in peptide synthesis as constrained surrogates of the Pro-Leu and Gly-Leu dipeptides. The Ac-[Gly-Leu]-Met-NH(2) derivatives (S,S,S)-2a and (S,R,S)-2b, with the tripeptidic C-terminal region present in tachykinins, are also synthesized. Conformational analyses of these tripetide analogues by NMR experiments and molecular modeling calculations show that both (S,S,S)-2a and (S,R,S)-2b epimers are gamma-turn/distorted type II beta-turn mimetics.     

Hydrogen bond structure and dynamics in aqueous electrolytes at ambient and supercritical conditions

Hydrogen bond (HB) connectivity in aqueous electrolyte solutions at ambient and supercritical conditions has been investigated by molecular dynamics techniques. Alkali metal and halides with different sizes have been considered. Modifications in the water HB architecture are more noticeable in the first ionic solvation shells and do not persist beyond the second shells. The coordination pattern is established between partners located in the first and second solvation shells. High-temperature results show dramatic reductions in the coordination number of water; at liquidlike densities the number of HBs is close to 2, while in steamlike environments water monomers are predominant. The addition of ions does not bring important modifications in the original HB structure for pure water. From the dynamical side, the lifetime of HBs shows minor modifications due to the simultaneous competing effects from a weaker HB structure combined with a slower reorientational dynamics of water induced by the Coulomb coupling with solute. At supercritical conditions, the overall dynamics of HB is roughly 1 order of magnitude faster than that at ambient conditions, regardless of the particular density considered.     

New Functional Cyclic Aminomethylphosphine Ligands for the Construction of Catalysts for Electrochemical Hydrogen Transformations

Eight‐membered cyclic functional bisphosphines, namely 1,5‐di‐aryl‐3,7‐di(2‐pyridyl)‐1,5‐diaza‐3,7‐diphosphacyclooctanes (aryl=2‐pyridyl, m‐tolyl, p‐tolyl, diphenylmethyl, benzyl, (R)‐(+)‐(α‐methyl)benzyl), with 2‐pyridyl substituents on the phosphorus atoms have been synthesized by condensation of 2‐pyridylphosphine, formaldehyde, and the corresponding primary amine. The structures of some of these bisphosphines have been investigated by X‐ray crystallography. The bisphosphines readily form neutral P,P‐chelate complexes [(κ²‐P,P‐L)MCl₂], cationic bis‐P,P‐chelate complexes [(κ²‐P,P‐L)₂M]²⁺, or a five‐coordinate complex [(κ²‐P,P‐L)₂NiBr]Br. The electrochemical behavior of two of the nickel complexes, and their catalytic activities in electrochemical hydrogen evolution and hydrogen oxidation, including the fuel‐cell test, have been studied.