Substituted Aminoacetamides as Novel Leads for Malaria Treatment

Herein we describe the optimization of a phenotypic hit against Plasmodium falciparum based on an aminoacetamide scaffold. This led to N-(3-chloro-4-fluorophenyl)-2-methyl-2-{[4-methyl-3-(morpholinosulfonyl)phenyl]amino}propanamide (compound 28 ) with low-nanomolar activity against the intraerythrocytic stages of the malaria parasite, and which was found to be inactive in a mammalian cell counter-screen up to 25 μm . Inhibition of gametes in the dual gamete activation assay suggests that this family of compounds may also have transmission blocking capabilities. Whilst we were unable to optimize the aqueous solubility and microsomal stability to a point at which the aminoacetamides would be suitable for in vivo pharmacokinetic and efficacy studies, compound 28 displayed excellent antimalarial potency and selectivity; it could therefore serve as a suitable chemical tool for drug target identification.     

Catechol immobilized on crosslinked polystyrene resins by grafting or copolymerization: Incidence on metal ions adsorption

Porous poly(styrene-co-divinylbenzene) resins functionalized with catechol were prepared in two different ways. Catechol was either grafted on commercial Amberlite® XAD-4 resin via a reduced imine and diazo bridges or incorporated by direct copolymerization of divinylbenzene with dimethoxystyrene followed by deprotection of the methoxy groups. The efficiency of functionalization was evidenced by pyrolysis coupled with gas phase chromatography and infra-red spectroscopy. The amount of incorporated catechol inside the different resins was determined by acido-basic back titration and varies between 0.27 and 1.38 mmol/g of resin. Grafting resulted in a decrease of the surface area due to the blocking of some connections between the mesopores. For synthesized copolymers, high contents of divinylbenzene monomer led to high surface areas. Comparing metal retention properties of both kind of materials towards Pb(II), Cu(II), Ni(II) and Cd(II) ions proved the equivalence of these sorbents. At low metal concentration, interactions with the sorbents seem to be non specific whereas at higher concentration catechol is responsible for the retention properties. Since the synthesis of copolymers is easier than the grafting of sorbents, it appears to be a more attractive procedure to obtain chelating sorbents.     

Delineating the scientific footprint in technology: Identifying scientific publications within non-patent references

Indicators based on non-patent references (NPRs) are increasingly being used for measuring and assessing science–technology interactions. But NPRs in patent documents contain noise, as not all of them can be considered ‘scientific’. In this article, we introduce the results of a machine-learning algorithm that allows identifying scientific references in an automated manner. Using the obtained results, we analyze indicators based on NPRs, with a focus on the difference between NPR- and scientific non-patent references-based indicators. Differences between both indicators are significant and dependent on the considered patent system, the applicant country and the technological domain. These results signal the relevancy of delineating scientific references when using NPRs to assess the occurrence and impact of science–technology interactions.     

Effect of Travel Speed and Beam Focus on Porosity in Alloy 690 Laser Welds

Advances in laser welding technology, including fiber optic delivery and high power density, are increasing the applicability of this joining technique. The inherent benefits of laser welding include small heat-affected zones, minimal distortion, and limited susceptibility to cracking. These advantages are of special interest to next-generation nuclear power systems where welding solute-rich alloys is expected to increase. Alloy 690 (A690) is an advanced corrosion-resistant structural material used in many replacement components and in construction of new commercial power plants. However, the application of A690 is hindered by its difficult weldability using conventional arc welding, and laser welding is a promising alternate. This work studies the effects of travel speed and beam focus on porosity formation in partial penetration, autogenous A690 laser welds. Porosity has been characterized by light optical microscopy and x-ray computed tomography to quantify its percent volume in the welds. This work describes the tradeoff between weld penetration and defect density as a function of beam defocus and travel speed. Additionally, the role of shield gas in porosity formation is discussed to provide a mitigation strategy for A690 laser welding. A process map is provided that shows the optimal combinations of travel speed and beam defocus to minimize porosity and maximize weld penetration at a laser power of 4?kW.     

印刷转型

印刷企业必须在业务能够转型之前先转型。我们需要放弃过去对自己的看法,开始重新认识自己在市场上的真正价值。     

A 50-year analysis of gender differences in United States authorship of original research articles in two major anesthesiology journals

Scientometrics - Underrepresentation of women in academic medicine is strongly linked to differences in men’s and women’s scholarship and has been shown to substantially reduce the...     

Anti-fouling surface modified stainless steel for food processing

Fouling on food contact surfaces (e.g. heat exchangers, work tables, conveyors) during food processing has a significant impact on operating efficiency and can promote biofilm development. Processing raw milk on plate heat exchangers results in significant fouling of proteins as well as minerals, and is exacerbated by the wall heating effect. The surface of 316L stainless steel heat exchanger plates was modified to resist fouling during food processing. An electroless nickel plating process was used to co-deposit fluorinated nanoparticles onto 316L stainless steel. The ability to resist fouling was demonstrated on a pilot plant scale plate heat exchanger. The fluorinated nanoparticle modified steel reduced surface energy from 41.4 to 24.7 mN/m, and reduced foulant accumulation by 97%. The anti-fouling coating was demonstrated to improve heat transfer efficiency. Repeatability studies were performed and confirmed that the EN-PTFE surface coating maintained its anti-fouling properties through 10 independent processing runs. Co-deposition of fluorinated particles during electroless nickel plating represents an effective and commercially scalable method to prepare anti-fouling coatings on stainless steel.     

Experimental study and numerical simulation of the vertical bounce of a polymer ball over a wide temperature range

The dependence to temperature of the rebound of a solid polymer ball on a rigid slab is investigated. An acrylate polymer ball is brought to a wide range of temperatures, covering its glass to rubbery transition, and let fall on a granite slab while the coefficient of restitution, duration of contact, and force history are measured experimentally. The ball fabrication is controlled in the lab, allowing the mechanical characterization of the material by classic dynamic mechanical analysis. Finite element simulations of the rebound at various temperatures are run, considering the material as viscoelastic and as satisfying a WLF equation for its time–temperature superposition property. A comparison between the experiments and the simulations shows the strong link between viscoelasticity and time–temperature superposition properties of the material and the bounce characteristics of the ball.