Molecular Insights into an Antibiotic Enhancer Action of New Morpholine-Containing 5-Arylideneimidazolones in the Fight against MDR Bacteria

In the search for an effective strategy to overcome antimicrobial resistance, a series of new morpholine-containing 5-arylideneimidazolones differing within either the amine moiety or at position five of imidazolones was explored as potential antibiotic adjuvants against Gram-positive and Gram-negative bacteria. Compounds (7–23) were tested for oxacillin adjuvant properties in the Methicillin-susceptible S. aureus (MSSA) strain ATCC 25923 and Methicillin-resistant S. aureus MRSA 19449. Compounds 14–16 were tested additionally in combination with various antibiotics. Molecular modelling was performed to assess potential mechanism of action. Microdilution and real-time efflux (RTE) assays were carried out in strains of K. aerogenes to determine the potential of compounds 7–23 to block the multidrug efflux pump AcrAB-TolC. Drug-like properties were determined experimentally. Two compounds (10, 15) containing non-condensed aromatic rings, significantly reduced oxacillin MICs in MRSA 19449, while 15 additionally enhanced the effectiveness of ampicillin. Results of molecular modelling confirmed the interaction with the allosteric site of PBP2a as a probable MDR-reversing mechanism. In RTE, the compounds inhibited AcrAB-TolC even to 90% (19). The 4-phenylbenzylidene derivative (15) demonstrated significant MDR-reversal “dual action” for β-lactam antibiotics in MRSA and inhibited AcrAB-TolC in K. aerogenes. 15 displayed also satisfied solubility and safety towards CYP3A4 in vitro.     

Development of a New Highly Selective Monoclonal Antibody against Preferentially Expressed Antigen in Melanoma (PRAME) and Identification of the Target Epitope by Bio-Layer Interferometry

Background: Monoclonal antibodies (mAbs) against cancer biomarkers are key reagents in diagnosis and therapy. One such relevant biomarker is a preferentially expressed antigen in melanoma (PRAME) that is selectively expressed in many tumors. Knowing mAb’s epitope is of utmost importance for understanding the potential activity and therapeutic prospective of the reagents. Methods: We generated a mAb against PRAME immunizing mice with PRAME fragment 161–415; the affinity of the antibody for the protein was evaluated by ELISA and SPR, and its ability to detect the protein in cells was probed by cytofluorimetry and Western blotting experiments. The antibody epitope was identified immobilizing the mAb on bio-layer interferometry (BLI) sensor chip, capturing protein fragments obtained following trypsin digestion and performing mass spectrometry analyses. Results: A mAb against PRAME with an affinity of 35 pM was obtained and characterized. Its epitope on PRAME was localized on residues 202–212, taking advantage of the low volumes and lack of fluidics underlying the BLI settings. Conclusions: The new anti-PRAME mAb recognizes the folded protein on the surface of cell membranes suggesting that the antibody’s epitope is well exposed. BLI sensor chips can be used to identify antibody epitopes.     

Targeting Oxidative Stress with Antioxidant Duotherapy after Experimental Traumatic Brain Injury

We assessed the effect of antioxidant therapy using the Food and Drug Administration-approved respiratory drug N-acetylcysteine (NAC) or sulforaphane (SFN) as monotherapies or duotherapy in vitro in neuron-BV2 microglial co-cultures and validated the results in a lateral fluid-percussion model of TBI in rats. As in vitro measures, we assessed neuronal viability by microtubule-associated-protein 2 immunostaining, neuroinflammation by monitoring tumor necrosis factor (TNF) levels, and neurotoxicity by measuring nitrite levels. In vitro, duotherapy with NAC and SFN reduced nitrite levels to 40% (p < 0.001) and neuroinflammation to –29% (p < 0.001) compared with untreated culture. The treatment also improved neuronal viability up to 72% of that in a positive control (p < 0.001). The effect of NAC was negligible, however, compared with SFN. In vivo, antioxidant duotherapy slightly improved performance in the beam walking test. Interestingly, duotherapy treatment decreased the plasma interleukin-6 and TNF levels in sham-operated controls (p < 0.05). After TBI, no treatment effect on HMGB1 or plasma cytokine levels was detected. Also, no treatment effects on the composite neuroscore or cortical lesion area were detected. The robust favorable effect of duotherapy on neuroprotection, neuroinflammation, and oxidative stress in neuron-BV2 microglial co-cultures translated to modest favorable in vivo effects in a severe TBI model.     

Conductivity studies of sol-gel prepared BaCe0.85−xZrxY0.15O3−δ solid electrolytes using impedance spectroscopy

A systematic investigation on doped barium cerate perovskites on conductivity was performed by means of ac electrochemical impedance spectroscopy technique. BaCe_0.85?xZr_xY_0.15O_3?δ powders (x = 0, 0.1, 0.2, 0.3, 0.4) were prepared by a modified sol-gel Pechini method and sintered at 1,250 °C–1,450 °C, depending on Zr content, to obtain good densities (93–97% of the theoretical ones). The measured total conductivities for these solid solutions in three different atmospheres were reported: in dry oxygen, in dry nitrogen and wet (0.5 bar H₂O) hydrogen (5%H₂/Ar) atmospheres. Arrhenius plots recorded in dry oxygen as well as in dry nitrogen showed some residual hydration which remained in the specimens upon initial heating. The compositions with x = 0.3 and 0.4 gave conductivities close to 10^?2 S/cm in 5%H₂/Ar/H₂O atmosphere at 600 °C. The isothermal conductivities values showed a little variation for x from 0.2 to 0.4 between 500 and 800 °C.     

Easy obtainment of three-dimensional coordination polymer of zinc 1,2,4,5-benzenetetracarboxylate with para-amino-pyridinium cations

Within a wide study on coordination polymers coming from 1,2,4,5-benzenetetracarboxylate combined with aromatic amines and first row transition metal ions, we isolated and characterized a peculiar tridimensional coordination polymer made by an anionic mesoporous scaffold of Zn(II)-benzeneteracarboxylate whose charge is balanced by included p-aminopyridinium cations stacked up along two quasi-perpendicular crystallographic directions. The particular features of the solid state structure, easily obtained in standard conditions, prompts a wider research of possible related derivatives.     

A 3D QSAR model of 17beta-HSD1 inhibitors based on a thieno[2,3-d]pyrimidin-4(3H)-one core applying molecular dynamics simulations and ligand-protein docking

The 17beta-hydroxysteroid dehydrogenase type 1 (17beta-HSD1) enzyme plays a crucial role in female hormonal regulation by catalysing the NADPH-dependent reduction of the less potent estrone E1 into the biologically active estradiol E2. Because 17beta-HSD1 is a key enzyme in E2 biosynthesis, it has emerged as an attractive drug target for inhibitor development. Herein we report the plausible binding modes and a 3D QSAR model of 17beta-HSD1 inhibitors based on a (di)cycloalkenothieno[2,3-d]pyrimidin-4(3H)-one core. Two generated enzyme complexes with potent inhibitors were subjected to molecular dynamics simulation to mimic the dynamic process of inhibitor binding. A set of 17beta-HSD1 inhibitors based on the thieno[2,3-d]pyrimidin-4(3H)-one core were docked into the resulting active site, and a CoMFA model employing the most extensive training set to date was generated. The model was validated with an external test set. Active site residues involved in inhibitor binding and CoMFA fields for steric and electrostatic interactions were identified. The model will be used to guide structural modifications of 17beta-HSD1 inhibitors based on a thieno[2,3-d]pyrimidin-4(3H)-one core in order to improve the biological activity as well as in the design of novel 17beta-HSD1 inhibitors.     

Electrostatic spray painting of carbon fibre-reinforced epoxy composites

Electrostatic spray deposition (ESD) of aesthetic and protective low curable transparent powder coatings onto carbon fibre-reinforced epoxy composites (i.e., carbon laminates) is the matter of the present investigation. An original environment friendly pretreatment of the substrate, based on fluidized bed peening of glass beads followed by a moderate temperature oven baking, has been proposed. Then, the influence of ESD operational parameters on coating performance has been looked into.Design of experiments (DOE) was used to schedule the experimental trials. Coating thickness and its uniformity over the coated substrates upon curing was systematically evaluated. Further, visual appearance of the coatings was analyzed by both optical and stereoscopic microscopy. Finally, analysis of variance (ANOVA) was performed to model the available experimental data. Detailed examinations of the experimental results allowed to define the best settings of ESD process as well as the maximum deposition time before the occurrence of severe electrical breakdown in the powder layer and/or the increase in the incidence of massive back-ionization phenomena. Accordingly, 3D process maps of the coating thickness versus the operational parameters, applied voltage, feeding and auxiliary pressure, were developed, thus supporting the practitioners in their choices and in the identification of processing windows wide enough for practical purposes.     

Comparison of the electrochemical properties of intermediate temperature solid oxide fuel cells based on protonic and anionic electrolytes

The physico-chemical properties of two protonic electrolytes BaCe_0.8Y_0.2O_3-δ and BaCe_0.9Y_0.1O_3-δ were investigated. The BaCe_0.8Y_0.2O_3-δ electrolyte showed better crystallographic purity and lower amount of carbonate phase on the surface. A comparison between the BaCe_0.8Y_0.2O_3-δ protonic electrolyte supported cell and an anionic (Ce_0.8Gd_0.2O_1.95) one was made. The maximum power densities (IR-free) of 183 mW cm⁻² and 400 mW cm⁻² were obtained in H₂ (R.H. 3%) at 700 °C, for the protonic and anionic electrolyte based cells, respectively.     

IRIS: Integrated data gathering and interest dissemination system for wireless sensor networks

This paper presents IRIS, an integrated interest dissemination and convergecasting solution for wireless sensor networks (WSNs). The interest dissemination protocol is used to build and maintain the network topology and for task/instruction assignment, while convergecasting implements data gathering at the network sink. Convergecasting heavily exploits cross-layering in that MAC and routing operation are performed jointly and relay selection is based on flexible cost functions that take into account information from different layers. The definition of the IRIS cost function enables tradeoff between key end-to-end performance metrics. In addition, it provides mechanisms for supporting efficient network behavior such as in-network data aggregation or processing. Energy usage is minimized by exploiting density estimation, sleeping modes and duty cycle control in a distributed and autonomous manner and as a function of the traffic intensity. Finally, IRIS is self adaptive, highly localized and imposes limited control overhead. IRIS performance is evaluated through ns2 simulations as well as through experiments on a WSN testbed. Comparative performance results show that IRIS outperforms previous cross-layer solutions. The flexibility introduced by the IRIS cross-layer approach results in higher robustness than that of well-known approaches such as BoX-MAC and CTP.