Polymer-coated BiOCl nanosheets for safe and regioselective gastrointestinal X-ray imaging.

Bismuth-based compounds are considered to be the best candidates for computed tomography (CT) imaging of gastrointestinal (GI) tract due to high X-ray absorption. Here, we report the introduction of polymer-coated bismuth oxychloride (BiOCl) nanosheets for highly efficient CT imaging in healthy mice and animal with colitis. We demonstrate simple, low cost and fast aqueous synthesis protocol which provides gram-quantity yield of chemically stable BiOCl nanosheets. The developed contrast gives 2.55-fold better CT enhancement compared to conventional contrast with negligible in vivo toxicity. As a major finding we report a regioselective CT imaging of GI tract by using nanoparticles coated with differentially charged polymers. Coating of nanoparticles with a positively charged polymer leads to their fast accumulation in small intestine, while the coating with negatively charged polymers stimulates prolonged stomach retention. We propose that this effect may be explained by a pH-controlled aggregation of nanoparticles in stomach. This feature may become the basis for advancement in clinical diagnosis of entire GI tract.

[Morphological features of non-traumatic intramuscular hemorrhage]. / Morfologicheskie osobennosti netravmaticheskikh vnutrimyshechnykh krovoizliyanii.

The formation of non-traumatic intramuscular hemorrhages does not depend on the cause of death. They usually occur in the muscles attached to the rib cage, which are or may be involved in the inhalation process (84.6%). More often, non-respiratory muscles are damaged (66%), less often auxiliary respiratory muscles (15.5%), extremely rarely - the main respiratory muscles (3.3%). In hypothermia, the majority of hemorrhages are formed in the iliopsoas muscles (13.9%). The main reason for the appearance of hemorrhages is muscle overstrain in the agonal period due to increased respiratory activity and seizures. The motor activity of the upper extremities during drowning, prolonged static muscle tension during hypothermia may matter. A microscopic picture usually indicates the formation of hemorrhages shortly before death, and occasionally signs of anxiety are noted.

[The historical examples of 'self-bumping' by inadvertency]. / Istoricheskie primery 'samonatykaniia' po neostorozhnosti.

The stories of 'self-bumping up' against a sharp object by inadvertency appeared in the historical chronicles with a periodicity of once per each 1000 years. The victims of such accidents include, inter alia, the Persian tsar Kambik II (522 b.c), Russian tsarevich Dimitry (1591), etc. The forensic medical analysis of the self-bumping by inadvertency episodes involving the historical characters made it possible to evaluate the circumstances, specific features and mechanism of the resulting injuries, the specific features of the inflicted wounds and their outcomes.

[The problem of molecular-genetic identification of sweat and grease deposits in the human fingerprints].

The objective of the present experimental molecular-genetic study of DNA contained in of human fingerprints was to establish the relationship between the reference genetic profiles and the genotypes of the individuals leaving their fingerprints on a smooth metal object. The biological material for the purpose of the investigation was sampled at different time intervals. The were taken using a scotch tape and used to obtain the complete genetic profile immediately after the fingerprints had been left as well as within the next 24 hours and one week. It proved impossible to identify the complete genetic profile one month after the fingerprints had been left. The alleles not typical for reference samples were identified within one week after swabbing the material from the metal surface. The results of the sudy can be explained by the decrease of the concentration of the initial DNA-matrix in the samples due to its degradation in the course of time. It is concluded that the parallel genetic analysis is needed if reliable evidence of identity of the profiles of interest or its absence is to be obtained.

Correction: Controlling molecular ordering in solution-state conjugated polymers.

Correction for 'Controlling molecular ordering in solution-state conjugated polymers' by J. Zhu et al., Nanoscale, 2015, DOI: 10.1039/c5nr02037a.

Controlling molecular ordering in solution-state conjugated polymers.

Rationally encoding molecular interactions that can control the assembly structure and functional expression in a solution of conjugated polymers hold great potential for enabling optimal organic optoelectronic and sensory materials. In this work, we show that thermally-controlled and surfactant-guided assembly of water-soluble conjugated polymers in aqueous solution is a simple and effective strategy to generate optoelectronic materials with the desired molecular ordering. We have studied a conjugated polymer consisting of a hydrophobic thiophene backbone and hydrophilic, thermo-responsive ethylene oxide side groups, which shows a step-wise, multi-dimensional assembly in water. By incorporating the polymer into phase-segregated domains of an amphiphilic surfactant in solution, we demonstrate that both chain conformation and degree of molecular ordering of the conjugated polymer can be tuned in hexagonal, micellar and lamellar phases of the surfactant solution. The controlled molecular ordering in conjugated polymer assembly is demonstrated as a key factor determining the electronic interaction and optical function.

[The historical aspects of the notion of "self-striking" in the Russian- and foreign-language literature].

This article was designed to illustrate specific features of the injuries inflicted by the sharp objects as a result of the so-called self-striking based on the examples from the historical and literary works. The forensic medical characteristics of such cases are provided.

Breaking the limits of structural and mechanical imaging of the heterogeneous structure of coal macerals.

The correlation between local mechanical (elasto-plastic) and structural (composition) properties of coal presents significant fundamental and practical interest for coal processing and for the development of rheological models of coal to coke transformations. Here, we explore the relationship between the local structural, chemical composition, and mechanical properties of coal using a combination of confocal micro-Raman imaging and band excitation atomic force acoustic microscopy for a bituminous coal. This allows high resolution imaging (10s of nm) of mechanical properties of the heterogeneous (banded) architecture of coal and correlating them to the optical gap, average crystallite size, the bond-bending disorder of sp(2) aromatic double bonds, and the defect density. This methodology allows the structural and mechanical properties of coal components (lithotypes, microlithotypes, and macerals) to be understood, and related to local chemical structure, potentially allowing for knowledge-based modeling and optimization of coal utilization processes.

Open loop Kelvin probe force microscopy with single and multi-frequency excitation.

Conventional Kelvin probe force microscopy (KPFM) relies on closed loop (CL) bias feedback for the determination of surface potential (SP). However, SP measured by CL-KPFM has been shown to be strongly influenced by the choice of measurement parameters due to non-electrostatic contributions to the input signal of the bias feedback loop. This often leads to systematic errors of several hundred mV and can also result in topographical crosstalk. Here, open loop (OL)-KPFM modes are investigated as a means of obtaining a quantitative, crosstalk free measurement of the SP of graphene grown on Cu foil, and are directly contrasted with CL-KPFM. OL-KPFM operation is demonstrated in both single and multi-frequency excitation regimes, yielding quantitative SP measurements. The SP difference between single and multilayer graphene structures using OL-KPFM was found to be 63 ± 11 mV, consistent with values previously reported by CL-KPFM. Furthermore, the same relative potential difference between Al2O3-coated graphene and Al2O3-coated Cu was observed using both CL and OL techniques. We observed an offset of 55 mV between absolute SP values obtained by OL and CL techniques, which is attributed to the influence of non-electrostatic contributions to the input of the bias feedback used in CL-KPFM.

[Dynamics of postmortem autolysis of cardiomyocytes].

Dynamics of postmortem autolysis of cardiocytes was evaluated using cells and tissues obtained from the patients who died from acute forms of ischemic heart disease, such as acute coronary insufficiency and acute myocardial infarction in the pre-necrotic phase. The studies were carried out at a temperature of 7, 20, and 37 degrees C. It was shown that autolysis of cardiac muscular fibers proceeds through three successive stages. A rise in temperature from 7 to 20 degrees C accelerated autolysis by one third while further elevation of the temperature up to 37 degrees C was associated with a 9-fold decrease in the duration of autolysis.

Symmetry relationship and strain-induced transitions between insulating M1 and M2 and metallic R phases of vanadium dioxide.

The ability to synthesize VO2 in the form of single-crystalline nanobeams and nano- and microcrystals uncovered a number of previously unknown aspects of the metal-insulator transition (MIT) in this oxide. In particular, several reports demonstrated that the MIT can proceed through competition between two monoclinic (insulating) phases M1 and M2 and the tetragonal (metallic) R phase under influence of strain. The nature of such phase behavior has been not identified. Here we show that the competition between M1 and M2 phases is purely lattice-symmetry-driven. Within the framework of the Ginzburg-Landau formalism, both M phases correspond to different directions of the same four-component structural order parameter, and as a consequence, the M2 phase can appear under a small perturbation of the M1 structure such as doping or stress. We analyze the strain-controlled phase diagram of VO2 in the vicinity of the R-M2-M1 triple point using the Ginzburg-Landau formalism and identify and experimentally verify the pathways for strain-control of the transition. These insights open the door toward more systematic approaches to synthesis of VO2 nanostructures in desired phase states and to use of external fields in the control of the VO2 phase states. Additionally, we report observation of the triclinic T phase at the heterophase domain boundaries in strained quasi-two-dimensional VO2 nanoplatelets, and theoretically predict phases that have not been previously observed.

The role of birds in dissemination of Francisella tularensis: first direct molecular evidence for bird-to-human transmission.

During a recent large tularemia outbreak in Bulgaria we found several cases that were remote from the main focus. One case had an unusual mode of transmission. A hunter acquired tularemia through a nail scratch from a buzzard (Buteo buteo) and consequently developed a typical ulceroglandular form of the disease. The diagnosis was confirmed by serological methods and successful cultivation. Comparative strain typing was performed by high-resolution multi-locus variable-number tandem repeat analysis (MLVA). The isolated strain was identical to one of the outbreak genotypes. We consider that this case represents a bird-to-human transmission of F. tularensis.

[Approaches to the choice of control group for a pathomorphological study of the heart].

It is generally accepted that an optimal control group for pathomorphological studies of the heart should be constituted by individuals who died from a craniocerebral injury without near-death experience. Polarization microscopy is a principal tool for the assessment of pathomorphological characteristics of myocardium. The presence of ethanol in the blood of a dead individual is associated with enhanced permeability of vascular walls, venous plethora, sludge phenomenon, microcirculatory thrombosis, perivascular and intermuscular oedema but does not on the whole interfere with the objective evaluation of microscopic images of the cardiac muscle.

[Information value of electrolytes, glucose, and urea in pericardial liquid in different terminal conditions].

The informative worth of sodium, potassium, calcium, magnesium, glucose, and urea levels in the pericardial liquid is analysed. The values of these parameters in a terminal disease of cerebral origin may testify to the absence of disturbances of energy and protein metabolism or electrolyte disbalance in the myocardium. Disturbances of myocardial electrolyte balance, energy and protein metabolism develop in cardiac, pulmonary, and mixed type terminal conditions. Cardiac arrest is associated with impaired myocardial conduction.

Real-time imaging of vertically aligned carbon nanotube array growth kinetics.

In situ time-lapse photography and laser irradiation are applied to understand unusual coordinated growth kinetics of vertically aligned carbon nanotube arrays including pauses in growth, retraction, and local equilibration in length. A model is presented which explains the measured kinetics and determines the conditions for diffusion-limited growth. Laser irradiation of the growing nanotube arrays is first used to prove that the nanotubes grow from catalyst particles at their bases, and then increase their growth rate and terminal lengths.

[Myocardial morphology in cases of death from acute heart ischemic disease].

The death from acute ischemic heart diseases (acute coronary insufficiency (n = 39) and acute myocardial infarction (n = 36) is accompanied by a slight increase in the thickness of the left ventricular wall with preserved normal heart weight. Microscopically, there are longer intermuscular distances, cardiomyocytic thickening, nuclear polymorphism, contractures, and destruction of myocytes and their lysis.

[Relationship of microscopic myocardial changes to the biochemical parameters of pericardial fluid in acute forms of coronary heart disease].

The postmortem diagnostics of acute forms of coronary heart disease showed that third-degree cardiomyocytic damages, primary lumpish destruction, and intracellular myocytolysis are attended by elevated cardiac troponin I levels in pericardial fluid and by enhanced activity aspartate aminotransferase and lactate dehydrogenase.

[Microscopic lesions of the myocardium in acute coronary heart disease].

A statisticomathematical analysis of microscopic changes in the myocardium has established pathognomonic and differential-diagnostic morphological signs for diagnosis of acute ischemic heart disease--acute coronary failure and acute myocardial infarction at the prenecrotic stage. The results of chromotrop 2B water blue staining of histological preparations and polarization microscopy were compared.