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The vast size of composition space poses a significant challenge for materials chemistry: exhaustive enumeration of potentially interesting compositions is typically infeasible, hindering assessment of important criteria ranging from novelty and stability to cost and performance. We report a tool, Comgen, for the efficient exploration of composition space, which makes use of logical methods from computer science used for proving theorems. We demonstrate how these techniques, which have not previously been applied to materials discovery, can enable reasoning about scientific domain knowledge provided by human experts. Comgen accepts a variety of user-specified criteria, converts these into an abstract form, and utilises a powerful automated reasoning algorithm to identify compositions that satisfy these user requirements, or prove that the requirements cannot be simultaneously satisfied. In contrast to machine learning techniques, explicitly reasoning about domain knowledge, rather than making inferences from data, ensures that Comgen's outputs are fully interpretable and provably correct. Users interact with Comgen through a high-level Python interface. We illustrate use of the tool with several case studies focused on the search for new ionic conductors. Further, we demonstrate the integration of Comgen into an end-to-end automated workflow to propose and evaluate candidate compositions quantitatively, prior to experimental investigation. This highlights the potential of automated formal reasoning in materials chemistry., (© 2024 The Author(s). Angewandte Chemie International Edition published by Wiley-VCH GmbH.)

The crystal structures of known materials contain the information about the interatomic interactions that produced these stable compounds. Similar to the use of reported protein structures to extract effective interactions between amino acids, that has been a useful tool in protein structure prediction, we demonstrate how to use this statistical paradigm to learn the effective inter-atomic interactions in crystalline inorganic solids. By analyzing the reported crystallographic data for inorganic materials, we have constructed statistically derived proxy potentials (SPPs) that can be used to assess how realistic or unusual a computer-generated structure is compared to the reported experimental structures. The SPPs can be directly used for structure optimization to improve this similarity metric, that we refer to as the SPP score. We apply such optimization step to markedly improve the quality of the input crystal structures for DFT calculations and demonstrate that the SPPs accelerate geometry optimization for three systems relevant to battery materials. As this approach is chemistry-agnostic and can be used at scale, we produced a database of all possible pair potentials in a tabulated form ready to use., (© 2024 The Authors. ChemPhysChem published by Wiley-VCH GmbH.)

Crystalline materials enable essential technologies, and their properties are determined by their structures. Crystal structure prediction can thus play a central part in the design of new functional materials 1,2 . Researchers have developed efficient heuristics to identify structural minima on the potential energy surface 3-5 . Although these methods can often access all configurations in principle, there is no guarantee that the lowest energy structure has been found. Here we show that the structure of a crystalline material can be predicted with energy guarantees by an algorithm that finds all the unknown atomic positions within a unit cell by combining combinatorial and continuous optimization. We encode the combinatorial task of finding the lowest energy periodic allocation of all atoms on a lattice as a mathematical optimization problem of integer programming 6,7 , enabling guaranteed identification of the global optimum using well-developed algorithms. A single subsequent local minimization of the resulting atom allocations then reaches the correct structures of key inorganic materials directly, proving their energetic optimality under clear assumptions. This formulation of crystal structure prediction establishes a connection to the theory of algorithms and provides the absolute energetic status of observed or predicted materials. It provides the ground truth for heuristic or data-driven structure prediction methods and is uniquely suitable for quantum annealers 8-10 , opening a path to overcome the combinatorial explosion of atomic configurations., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

The selection of the elements to combine delimits the possible outcomes of synthetic chemistry because it determines the range of compositions and structures, and thus properties, that can arise. For example, in the solid state, the elemental components of a phase field will determine the likelihood of finding a new crystalline material. Researchers make these choices based on their understanding of chemical structure and bonding. Extensive data are available on those element combinations that produce synthetically isolable materials, but it is difficult to assimilate the scale of this information to guide selection from the diversity of potential new chemistries. Here, we show that unsupervised machine learning captures the complex patterns of similarity between element combinations that afford reported crystalline inorganic materials. This model guides prioritisation of quaternary phase fields containing two anions for synthetic exploration to identify lithium solid electrolytes in a collaborative workflow that leads to the discovery of Li 3.3 SnS 3.3 Cl 0.7. The interstitial site occupancy combination in this defect stuffed wurtzite enables a low-barrier ion transport pathway in hexagonal close-packing., (© 2021. The Author(s).)

Technologies such as batteries, biomaterials and heterogeneous catalysts have functions that are defined by mixtures of molecular and mesoscale components. As yet, this multi-length-scale complexity cannot be fully captured by atomistic simulations, and the design of such materials from first principles is still rare 1-5 . Likewise, experimental complexity scales exponentially with the number of variables, restricting most searches to narrow areas of materials space. Robots can assist in experimental searches 6-14 but their widespread adoption in materials research is challenging because of the diversity of sample types, operations, instruments and measurements required. Here we use a mobile robot to search for improved photocatalysts for hydrogen production from water 15 . The robot operated autonomously over eight days, performing 688 experiments within a ten-variable experimental space, driven by a batched Bayesian search algorithm 16-18 . This autonomous search identified photocatalyst mixtures that were six times more active than the initial formulations, selecting beneficial components and deselecting negative ones. Our strategy uses a dexterous 19,20 free-roaming robot 21-24 , automating the researcher rather than the instruments. This modular approach could be deployed in conventional laboratories for a range of research problems beyond photocatalysis.

Aim: To determine clinical/instrumental predictors of symptomatic epilepsy after ischemic stroke in children., Material and Methods: One hundred and thirty-six patients, aged 0-15 years, with the diagnosis of ischemic stroke (ICD-10 I63.0-I63.9) were examined. The duration of the study was 18 months - 12 years. Patients were stratified into post-stroke (n=22) and control (n=114) groups, the latter included patients without epilepsy regardless of the presence of convulsive seizures in the acute stage of stroke. Predictors were determined based on EEG and characteristics of convulsive syndrome in the acute stage of stroke., Results and Conclusion: The following prognostic criteria were found: generalized type of seizures, focal type of seizures with secondary generalization, epileptiform (peak and/or peak-wave) activity, focal character of epileptiform activity, generalized type of seizures in the combination with slow wave background activity on EEG, generalized type of seizures in the combination with slow wave activity and disorganized activity on EEG.

The data on the risk factors and etiology of ischemic stroke in 31 infants, aged under 3 years, are summarized. The results of genotyping of blood coagulation and folic acid gene polymorphisms in patients and 83 healthy people are presented. Significant differences were found for -455 G>A FGB (р=0.03) and 807 C>T ITGA2 (р=0,005) polymorphisms. Different gene-gene combinations that can cause hypercoagulation and arterial thrombosis in this age were identified. The most frequent combinations include polymorphisms of genes for FGB, fibrinolysis system and folate cycle enzymes (OR=3,79 and more, p<0.05). A clinical case of ischemic stroke in a girl, aged 10 months, after operated congenital heart malformation is presented.

Efficacy of omaron (a combination of piracetam 400 mg and cinnarizin 25 mg) has been studied 3 months after stroke in 90 post-stroke patients. Forty-five patients receiving the basic therapy (antihypertensive and antithrombotic drugs, statins) have been included in the control group and 45 patients of the main group received in addition omaron (1 pill 3 times daily during 2 months). Intensity of neurologic disturbances, degree of disability, cognitive functions assessed by neuropsychological tests (the Mini-Mental State Examination, the Frontal Assessment battery, the Five words test, the Clock drawing test, the Schulte test) and emotional state (the Centre for Epidemiologic Studies Depression scale, the Spilberger scale) have been measured. During the period of the study, none of the patients had stroke or myocardial infarction. The improvement of indices of neurological status, decrease of disability degree and normalization of arterial pressure were found in both groups after 2 months of treatment. The significant improvement (p<0,05) of performance on tests for neurocognitive functions and parameters of emotional state was noted in patients treated with omaron compared to those of the control group. The good tolerability of omaron, absence of serious side-effect in combination with other drugs used for prevention of secondary stroke were reported.

Results of study of capsule formation and immunologic properties of capsular antigen of attenuated strain LA-25 of Pasteurella multocida grown on liquid medium from non-food materials and Hottinger's broth depending on cultivation time are presented.

The characterization of E.coli strains O157:H7, isolated from humans and animals on some territories of the Central Federal District, is presented. Among the isolates from human outbreaks, related and, probably, related cultures prevailed, while among the isolates obtained from different animals mainly unrelated cultures have been detected. A conclusion has been made concerning the existence of several independent zoonotic reservoirs of E. coli O157:H7 infection on this territory. The advantages and drawbacks of the use of pulse electrophoresis in the characterization of E. coli O157:H7 are discussed. Grounds are given for the necessity of the patients examination with hemorrhagic enetrocolitis for the presence of E. coli O157:H7, as well as for the expediency of having a special item for the registration of this E. coli infection in relevant statistical forms.

The distribution of Campylobacter spp. on 13 poultry farms (broiler chicken, quail, pheasant, peacock, and turkey) from eight regions (Vladimir, Vologda, Voronezh, Kaluga, Liptsk, Moscow, Orenburg, and Orel) in Russia was surveyed. Intestinal materials were plated onto Campylobacter-selective medium and plates were incubated microaerobically at 42 degrees C for 24 or 48 h. Identification was based on colonial morphology, microscopic examination, and biochemical tests; latex agglutination assays were used for confirmation. In total, 116 isolates were derived from 370 samples. Isolation rates were similar, regardless of whether the birds were from small or large broiler production farms. Susceptibility of 48 representative (from these production sources) strains of Campylobacter spp. to 38 antimicrobial compounds was determined by disk diffusion assays. All strains tested were sensitive to amikacin, gentamycin, sisomycin, chloramphenicol, imipenem, oleandomycin, erythromycin, azitromycin, and ampicillin. The strains were also sensitive to 100 microg/disk of carbenicillin, fluoroquinolones, and to nitrofurans. Fluoroquinolone sensitivity was most notable and may be related to its limited application in poultry production within Russia. Hippurate and ribosomal RNA gene primers were developed and used to distinguish Campylobacter jejuni and Campylobacter coli and to provide a measure of strain discrimination. The combination of PCR analysis and randomly amplified polymorphic DNA (RAPD) typing were conducted for selected isolates. The various poultry species and the different locations yielded Campylobacter isolates with discrete randomly amplified polymorphic DNA patterns. The distribution and substantial diversity of Campylobacter spp. isolates appears similar to that previously reported in other countries.

This work presents a method for purification of lysostaphin, a glycylglycine endopeptidase, from the culture liquid of S. simulans biovar staphylolyticus to homogeneity in a few steps. The method includes ultrafiltration and ion-exchange and hydrophobic chromatographies. The enzyme was isolated in preparative amounts with the yield of 51%. Some physical and chemical properties of the enzyme are described.

A sensitive and precise method for quantifying protease and peptidase activities is suggested. N-Terminal amino groups of peptides which are formed during hydrolysis of the substrates react with trinitrobenzenesulfonic acid (TNBS), and the trinitrophenyl (TNP) derivatives are determined spectrophotometrically. Spontaneous hydrolysis of TNBS is considerably diminished on trinitrophenylation at pH 7.4 rather than at pH 9-10 as is usually used. The trinitrophenylation method can be used to determine the initial rate of hydrolysis and the kinetics of reactions catalyzed by proteases and peptidases.

Some pathogenic bacteria have been demonstrated to secrete specific IgA1-proteases, the enzymes cleaving the molecules of the first subclass of human immunoglobulin (IgA1) in the single point from the hinge with the formation of Fab- and Fc-fragments. Cleavage generally deprives immunoglobulins having defense properties and the enzymes are considered as pathogenic factors. How to determine the activity, purification, and the promises of use of IgA-proteases is described. Whether inactivated meningococcal IgA1-protease as a vaccine against any of the five (A, B, C, Y, W135) serotypes of pathogenic meningococci is discussed.

A child aged 3 years 10 months with latent early stage of primary myopathy died during surgery for left-side cryptorchidism after injection of lysthenon. Asystole, the immediate cause of death, was caused by release of potassium ions from skeletal muscles into the blood. Myopathy was diagnosed at autopsy by histological examination of the diaphragm and mm. pectoralis major and gastrocnemius.

The authors investigated a procedure for isolating lysostaphine, a complex of enzymes that lyse the cells of virtually any S. aureus strains in the fermenter and large bottles. It was shown that the activity of the enzyme in the fermenter might be much higher than in the flask. The enzyme can be concentrated on the hollow fibers, purified on the ion exchanger and kept without decreasing its activity within a year. The process can be scaled and, lysostaphine may be used in the treatment of man and animals after its proper biological tests.

The paper outlines a digital radiographic device which records radiation by scanning with a one-dimensional multiwire proportional chamber connected on-line to a computer. The device drastically reduces a dosage load on patients, improves the diagnostic potentialities of projectional radiography, yields quantitative diagnostic information, creates special diagnostic programmes, has fast-access and fire-safe archives. The device may be used for general-purpose radiographic examinations and it has advantages when used instead of conventional fluorographs.

The plasmid profile, virulence and antibacterial drug susceptibility of various strains of E. rhusiopathiae were determined. No correlations between the virulence of the strains, their antibiotic resistance and the plasmid content were detected. Structural and functional analysis of one of the isolated plasmids was carried out to use the plasmid as a vector in the genetic study of E. rhusiopathiae.

The Salmonella typhimurium B-2/1 double mutant with cya and crp mutations was obtained by a recombination process. The mutant exhibited a low virulence and inability to utilize citrate. In terms of these properties, the mutant differs from the wild-type strain. The mutant is able to persist in the body of mice, cattle, and monkeys, provoking the immune response to its oral administration.

Influence of space and time coherence, spectral density and polarization of laser radiation upon the light absorption by hemolyzate, oxyhaemoglobin and catalase is studied experimentally. It is shown that the main physical factor of laser radiation defining the light absorption by the analysed biological molecules is time coherence and hence, the monochromatic property of laser beam.