PTML modeling for peptide discovery: in silico design of non-hemolytic peptides with antihypertensive activity

Molecular Diversity - Hypertension is a medical condition that affects millions of people worldwide. Despite the high efficacy of the current antihypertensive drugs, they are associated with...     

Darstellung und Eigenschaften von Chromtricarbonyl-Komplexen strukturisomerer Borazin-Derivate

The new hexaalkylborazine chromium tricarbonyls (n-Pr)₃B₃N₃Me₃Cr(CO)₃ (V), Me₃B₃N₃(n-Pr)₃Cr(CO)₃ (VI), (i-Pr)₃B₃N₃Me₃Cr(CO)₃ (VII) and Me₃B₃N₃(i-Pr)₃Cr(CO)₃ (VIII) have been prepared from fac-Cr(CO)₃(MeCN)₃ and the corresponding borazine in dioxane or without solvent. They are much more labile than the isomeric complex Et₃B₃N₃Et₃Cr(CO)₃ (IV) which can be readily obtained from Et₃B₃N₃Me₃Cr(CO)₃ and Et₃B₃N₃Et₃ by ring ligand exchange. The NMR., IR., UV. and Mass spectroscopic data of the complexes IV–VIII will be briefly discussed. The preparation of the borazine derivatives (n-Pr)₃B₃N₃Me₃ (IX) and Me₃B₃N₃(n-Pr)₃ (X) is also reported.     

Borazin—metallkomplexe : VI. Über ligandenaustauschreaktionen an borazin—metallkomplexen: synthese von B-trimethylborazin-tricarbonylchrom

Me₃B₃N₃H₃Cr(CO)₃ has been obtained by ring-ligand exchange starting from Et₃B₃N₃Me₃Cr(CO)₃ and Me₃B₃N₃H₃. The new compound has been characterised by means of their IR, NMR, UV and mass spectroscopic data.     

Phase separation and disorder in half metallic ferromagnetic manganite thin films: A theoretical study looking forward low noise nano-devices

The resistivity of thin La_0.7Sr_0.3MnO₃ films was first investigated in a wide temperature (T) range (10–750 K). Films grown by different techniques and on several substrates enabled to analyze samples with different amounts of disorder. The aim of this work was to elucidate the nature of the metal–insulator (M–I) transition occurring at T = T_p in these films and its relation with the different kinds of inhomogeneities they could present like intrinsic electric disorder and co-existence of two different electrical and/or magnetic phases. The low-temperature resistivity state was described mostly by a law which scales as T with  ≈ 2.5. This supports the theoretical proposal of single magnon scattering in presence of minority spin states localized by the disorder. In the whole range of temperatures the experimental data are found to be consistent with a phase separation (PS) scenario. In order to go through the origin of the characteristic length scale of inhomogeneity found, preliminarily low frequency noise measurements as a function of T in a range of temperature around the M–I transition were made. The samples used were patterned using photolithography into bridges with various widths and lengths. No clear sign of separation phase dynamic has been observed in our noise measurements. Unexpectedly the normalized Hooge parameter _H/n was found not to be volume (Ω) independent. The LSMO electrical properties may strongly be driven by disorder and new design for magnetoresistance sensors may have to take into account their intrinsic PS.     

Cationic organometallic complexes with hexaalkylborazines: I. Synthesis and reactivity of cationic hexamethylborazinerhodium complexes with carbonyl,ethylene and diolefins as ligands

The PF₆ salts of the new cationic hexamethylborazinerhodium(I) complexes of general formula [Rh(Me₃B₃N₃Me₃)(LL′)]⁺ (LL′= 1,5-cyclooctadiene, norbornadiene, tetrafluorobenzobarrelene, trimethyltetrafluorobenzobarrelene, L = L′ = ethylene, CO) have been prepared from the reaction between [RhCl(LL′)]₂, Me₃B₃NMe₃, and AgPF₆ in dichloromethane. These complexes are very labile, undergoing rapid ring ligand exchange in solution with σ and π-donor ligands. The synthesis of [Rh(η⁶-naphthalene)(COD)]PF₆ is also described. The properties and NMR and IR spectroscopic characteristics of the new compounds are briefly discussed.     

Tailoring the Thermal Conductivity of Rubber Nanocomposites by Inorganic Systems: Opportunities and Challenges for Their Application in Tires Formulation

The development of effective thermally conductive rubber nanocomposites for heat management represents a tricky point for several modern technologies, ranging from electronic devices to the tire industry. Since rubber materials generally exhibit poor thermal transfer, the addition of high loadings of different carbon-based or inorganic thermally conductive fillers is mandatory to achieve satisfactory heat dissipation performance. However, this dramatically alters the mechanical behavior of the final materials, representing a real limitation to their application. Moreover, upon fillers’ incorporation into the polymer matrix, interfacial thermal resistance arises due to differences between the phonon spectra and scattering at the hybrid interface between the phases. Thus, a suitable filler functionalization is required to avoid discontinuities in the thermal transfer. In this challenging scenario, the present review aims at summarizing the most recent efforts to improve the thermal conductivity of rubber nanocomposites by exploiting, in particular, inorganic and hybrid filler systems, focusing on those that may guarantee a viable transfer of lab-scale formulations to technological applicable solutions. The intrinsic relationship among the filler’s loading, structure, morphology, and interfacial features and the heat transfer in the rubber matrix will be explored in depth, with the ambition of providing some methodological tools for a more profitable design of thermally conductive rubber nanocomposites, especially those for the formulation of tires.     

Method for intracellular magnetic labeling of human mononuclear cells using approved iron contrast agents

A method for intracellular iron labeling of human mononuclear cells (lymphocytes and monocytes) for magnetic resonance imaging (MRI) using simple incubation of cells with approved MRI iron contrast agents is presented. Labeled cells can be detected by MRI in vitro, and this suggests the possibility that the technique could become a marker for in vivo lymphocyte and monocyte trafficking studies in acute inflammatory lesions such as those in Multiple Sclerosis.     

Interaction of NO with nanosized Ru-, Pd-, and Pt-Doped SnO2: electron paramagnetic resonance, Mössbauer, and electrical investigation

The mechanism of NO interaction with nanosized Ru(Pd,Pt)-doped SnO(2) was studied by electron paramagnetic resonance, M?ssbauer, and electric resistance measurements. Three steps were proposed for the reaction between the semiconductor oxide and the gaseous component: (i) the formation of bielectronic oxygen vacancies (V(o)) in SnO(2); (ii) their single-ionization (V(o)(*)) with injection of electrons into the SnO(2) conduction band; (iii) the subsequent transfer of electrons from V(o)(*) to [Ru(Pd,Pt)](4+). The last process induces the formation of further oxygen vacancies which reduce the transition metal centers to lower oxidation states; the redox processes is enhanced and the electrical resistance in transition metal-doped SnO(2) is stronger modified with respect to the undoped material.