COPEX: co-evolutionary crystal structure prediction algorithm for complex systems

Crystal structure prediction has been widely used to accelerate the discovery of new materials in recent years. Up to this day, it remains a challenge to predict the stable stoichiometries and structures of ternary or more complex systems due to the explosive increase of the size of the chemical and configurational space. Numerous novel materials with a series of unique characteristics are expected to be found in this virgin territory while new algorithms to predict crystal structures in complex systems are urgently called for. Inspired by co-evolution in biology, here we propose a co-evolutionary algorithm, which we name COPEX, and which is based on the well-known evolutionary algorithm USPEX. Within this proposed algorithm, a few USPEX calculations for ternary systems and multiple for energetically-favored pseudobinary or fixed-composition systems are carried out in parallel, and co-evolution is achieved by sharing structural information on the fittest individuals among different USPEX sub-processes during the joint evolution. We have applied the algorithm to W–Cr–B, Mg–Si–O, and Hf–Ta–C, three very different systems, and many ternary compounds have been identified. Our results clearly demonstrate that the COPEX algorithm combines efficiency and reliability even for complex systems.

Effects of Si/Al Ratios on the Bulk-Type Zeolite Formation Using Synthetic Metakaolin-Based Geopolymer with Designated Composition

In this paper, synthetic metakaolin with fixed composition (Al2O3·2SiO2) was produced by a simple chemosynthetic route. The chemosynthetic metakaolin can eliminate the influence of impurities in metakaolin from natural kaolin minerals. The synthetic metakaolin together with NaOH and SiO2-sol were used to prepare Na-based geopolymer precursors with various molar ratios of Si/Al. The molar ratios of Si/Al from 1 to 2 were tailored by adding different contents of SiO2-sol. Zeolite/geopolymer composites or monolith-type zeolite were successfully fabricated from synthetic metakaolin-based geopolymer through a hydrothermal process. The effects of Si/Al ratios on the phase composition and microstructure of the produced zeolite/geopolymer composites or zeolites were studied. The results proved that the composition of synthetic metakaolin and geopolymer precursors can be facilely tuned, and the monolithic geopolymer precursors can be mostly, or even totally, transformed into zeolite after hydrothermal treatment.

Pragmatic marker i pray in middle english written monuments

The article deals with the variations of predicative pragmatic marker I pray yow / thee. The linguistic material is taken from the texts that were written in XIV-XV centuries by English authors and created in different genres (plays, ballades, visions, confessions, etc.) containing elements of dialogic speech. It has been found that the marker was not a stiff structure during the period under consideration. The variations of the expression were formed as the result of miscellaneous processes that can be seen in its following features: non-fixed composition of the marker, that can be enlarged (by an adverb here I the pray, a modal verb I wold the pray) and can be reduced (by elision of a object pronoun I preye), non-permanent word order depending on the requirement of a rhyme and preferences of the writer (I þe praye, y pray Þe, preye I thee), the representation of the expression in the sentence as both parenthetical clause and main one (followed by a that-subordinate clause). The peculiarities of the location of the marker in the sentence are discussed. If I pray yow/thee is the only one pragmatic marker in the sentence, it is placed at the beginning or at the end of it. The placement of the parenthetical expression inside the receiving sentence is characteristic of the individual style of the author and is not common. If the expression is combined with other markers, predicative and non predicative, there are two variants of their localization in the sentence: «pointwise», when several markers are concentrated at the beginning or at the end of the construction, and «framework», when phatic parts are located in ante- and postposition of the markers receiving sentence.

Pressure-Dependent Tuning of Photoluminescence and Size Distribution of Carbon Nanodots for Theranostic Anticancer Applications

Carbon nanodots (CDs) have recently attracted attention in the field of nanomedicine because of the biocompatibility, cost-effective nature, high specific surface, good near infrared (NIR) photothermal conversion into heat and tunable fluorescence properties, which have paved the way toward incorporating use of CDs into innovative anticancer theranostic platforms. However, a reliable synthesis of CDs with established and controlled physiochemical proprieties is precluded owing to the lack of full manipulation of thermodynamic parameters during the synthesis, thus limiting their use in real world medical applications. Herein, we developed a robust solvothermal protocol which allow fine controlling of temperature and pressure in order to obtain CDs with tunable properties. We obtained different CDs by modulating the operating pressure (from 8 to 18.5 bar) during the solvothermal decomposition of urea and citric acid in N,N-dimethylformamide at fixed composition. Atomic force microscopy (AFM), Fourier transform infrared (FTIR), ultraviolet-visible (UV-vis) and fluorescence spectroscopy were used to assess the role of pressure in influencing size, optical and surface properties of the obtained CDs. While preliminary biological and anticancer performance of CDs was established on the MDA-MB-231 cell line, used as triple negative breast cancer model. Our results indicate that pressure impinge on the formation of carbon nanoparticles under solvothermal conditions and impart desired optical, size distribution, surface functionalization and anticancer properties in a facile way. However, we have highlighted that a strategic surface engineering of these CDs is needed to limit the adsorption of corona proteins and also to increase the average surface diameter, avoiding a rapid renal clearance and improving their therapeutic efficacy in vivo.

Halide perovskite nanocrystal arrays: Multiplexed synthesis and size-dependent emission

Halide perovskites have exceptional optoelectronic properties, but a poor understanding of the relationship between crystal dimensions, composition, and properties limits their use in integrated devices. We report a new multiplexed cantilever-free scanning probe method for synthesizing compositionally diverse and size-controlled halide perovskite nanocrystals spanning square centimeter areas. Single-particle photoluminescence studies reveal multiple independent emission modes due to defect-defined band edges with relative intensities that depend on crystal size at a fixed composition. Smaller particles, but ones with dimensions that exceed the quantum confinement regime, exhibit blue-shifted emission due to reabsorption of higher-energy modes. Six different halide perovskites have been synthesized, including a layered Ruddlesden-Popper phase, and the method has been used to prepare functional solar cells based on single nanocrystals. The ability to pattern arrays of multicolor light-emitting nanocrystals opens avenues toward the development of optoelectronic devices, including optical displays.

Reframing the Horizon within the Algorithmic Landscape of Northern Britain

Emerging from the artist’s constructed photographs and walking projects in the north, this paper considers the tension between the photograph as a fixed composition of the world and the dynamic image constructed from data. Whereas arguably, the traditional photograph exhibits a stable relationship between the world and the image, the constructed photograph shifts the focus onto the underlying algorithmic processes of production. This focus on the relational nature of the constructed photograph shifts our gaze from the horizon to the underlying systems in operation as we consider the relational nature of data as a photograph.

First Report on a Solvent-Free Preparation of Polymer Inclusion Membranes with an Ionic Liquid

A novel and environmentally-friendly procedure for the preparation of polymer inclusion membranes (PIMs) containing an ionic liquid is presented for the first time. Traditionally, PIMs are prepared by a solvent casting method with the use of harmful organic solvents. Here we report a new solvent-free procedure based on a thermal-compression technique which involve the melting of the components of the PIM and the application of a high pressure to the melted specimen to form a flat-sheet film. In our study, we have tested different polymers, such as two cellulose derivatives as well as two thermoplastic polymers, polyurethane (TPU) and poli ε-caprolactone (PCL). The ionic liquid (IL) trioctylmethylammonium chloride (Aliquat 336) has been used to produce PIMs with a fixed composition of 70% polymer–30% IL (w/w). Both TPU and PCL polymers provide successful membranes, which have been thoroughly characterized. PIMs based on the polymer PCL showed a high stability. To test whether the properties of the IL were affected by the preparation conditions, the extraction ability of Aliquat 336 was investigated for both PCL and TPU membranes in terms of Cr(VI) extraction. Satisfactory values (90% extraction) were obtained for both membranes tested, showing this novel procedure as a green alternative for the preparation of PIMs with ILs.

Design and Preclinical Development of a Phage Product for the Treatment of Antibiotic-Resistant Staphylococcus aureus Infections

Bacteriophages, viruses that only kill specific bacteria, are receiving substantial attention as nontraditional antibacterial agents that may help alleviate the growing antibiotic resistance problem in medicine. We describe the design and preclinical development of AB-SA01, a fixed-composition bacteriophage product intended to treat Staphylococcus aureus infections. AB-SA01 contains three naturally occurring, obligately lytic myoviruses related to Staphylococcus phage K. AB-SA01 component phages have been sequenced and contain no identifiable bacterial virulence or antibiotic resistance genes. In vitro, AB-SA01 killed 94.5% of 401 clinical Staphylococcus aureus isolates, including methicillin-resistant and vancomycin-intermediate ones for a total of 95% of the 205 known multidrug-resistant isolates. The spontaneous frequency of resistance to AB-SA01 was ≤3 × 10−9, and resistance emerging to one component phage could be complemented by the activity of another component phage. In both neutropenic and immunocompetent mouse models of acute pneumonia, AB-SA01 reduced lung S. aureus populations equivalently to vancomycin. Overall, the inherent characteristics of AB-SA01 component phages meet regulatory and generally accepted criteria for human use, and the preclinical data presented here have supported production under good manufacturing practices and phase 1 clinical studies with AB-SA01.

Tensile and Impact Properties of Recycled Poly(Ethylene Terephthalate) and Polycarbonate Composites Reinforced with Silane Treated Hollow Glass Microspheres

Recycled poly (ethylene terephthalate) or R-PET is conventionally melt blended with polycarbonate with the presence of chain extender in order to produce polymer blend that provides good mechanical properties and cost effectiveness. This research was carried out to improve properties of such a blend by compounding them with silane treated hollow glass microspheres (HGMs), which mixing procedure was emphasized how it could affect mechanical properties. R-PET/PC/HGM composites of a fixed composition were melt compounded with three different mixing procedures. It was found that the compounding HGMs with PC and then R-PET obtained the most rigidity specimens than the all-in-one compounding or the compounding HGMs with R-PET and then PC. Silane treated HGMs were well distributed in the polymer matrix presenting good interfacial adhesion. However, the notched impact strength of all composites were inspected to be in the same range.