is one of the most clinically important nosocomial pathogens. The World Health Organisation refers it to its «critical priority» category to develop new strategies for effective therapy. This ...microorganism is capable of producing structurally diverse capsular polysaccharides (CPSs), which serve as primary receptors for
bacteriophages carrying polysaccharide-depolymerasing enzymes. In this study, eight novel bacterial viruses that specifically infect
strains belonging to K2/K93, K32, K37, K44, K48, K87, K89 and K116 capsular types were isolated and characterized. The overall genomic architecture demonstrated that these viruses are representatives of the
genus of the family
The linear double-stranded DNA phage genomes of 41,105-42,402 bp share high nucleotide sequence identity, except for genes encoding structural depolymerases or tailspikes which determine the host specificity. Deletion mutants lacking N-terminal domains of tailspike proteins were cloned, expressed and purified. The structurally defined CPSs of the phage bacterial hosts were cleaved with the specific recombinant depolymerases, and the resultant oligosaccharides that corresponded to monomers or/and dimers of the CPS repeats (K-units) were isolated. Structures of the derived oligosaccharides were established by nuclear magnetic resonance spectroscopy and high-resolution electrospray ionization mass spectrometry. The data obtained showed that all depolymerases studied were glycosidases that cleave specifically the
CPSs by the hydrolytic mechanism, in most cases, by the linkage between the K-units.
, a nonfermentative, Gram-negative, aerobic bacterium, is one of the most significant nosocomial pathogens. The pathogenicity of
is based on the cooperative action of many factors, one of them being the production of capsular polysaccharides (CPSs) that surround bacterial cells with a thick protective layer. Polymorphism of the chromosomal capsule loci is responsible for the observed high structural diversity of the CPSs. In this study, we describe eight novel lytic phages which have different tailspike depolymerases (TSDs) determining the interaction of the viruses with corresponding
capsular types (K-types). Moreover, we elucidate the structures of oligosaccharide products obtained by cleavage of the CPSs by the recombinant depolymerases. We believe that as the TSDs determine phage specificity, the diversity of their structures should be taken into consideration as selection criteria for inclusion of certain phage candidate to the cocktail designed to control
with different K-types.
Rotational levels of molecular free radicals can be tuned to degeneracy by using laboratory-scale magnetic fields. Because of their intrinsically narrow width, these level crossings of ...opposite-parity states have been proposed for use in the study of parity-violating interactions and other applications. We experimentally study a typical manifestation of this system using BaF138. Using a Stark-mixing method for detection, we demonstrate level-crossing signals with spectral width as small as 6 kHz. We use our data to verify the predicted line shapes, transition dipole moments, and Stark shifts and to precisely determine molecular magnetic g factors. Our results constitute an initial proof of concept for use of this system to study nuclear spin-dependent parity-violating effects.
Novel unsymmetrical SCS'-pincer ligands, 1-PhNHC(S)-3-Ph(2)P(S)NH-C(6)H(4) (3) and 1-PhNHC(S)-3-Ph(2)P(S)OC(6)H(4) (7), bearing a thiocarbamoyl moiety in combination with thiophosphorylamino- and ...thiophosphoryloxy-donating groups, respectively, were obtained via thiophosphorylation of 3-amino- and 3-hydroxy-benzoic acid (thio)anilides 1 and 6. Direct cyclometallation of the central benzene ring in the ligands 3 and 7 in reaction with (PhCN)(2)MCl(2) (M = Pd, Pt) as a metal precursor afforded κ(3)-SCS'-hybrid pincer complexes 8, 9 with 5- and 6-membered fused metallacycles in good to high yields (67-95%). The complexes 8 and 9 were characterized by multinuclear NMR ((31)P, (1)H, (13)C) and IR spectroscopy as well as single-crystal X-ray crystallography. Palladium complexes 8a and 9a were shown to be active catalysts for the Suzuki-Miyaura cross-coupling reaction. In the solid state the ligands 3 and 7 as well as their Pt(II) and Pd(II) complexes 8 and 9 are luminescent at 300 K. The emission of the complexes has the different origin depending on the metal nature.
Features of the crystallization of various compounds on the Nafion polymer substrate from supersaturated aqueous solutions is studied by XRD. The solutions are prepared from natural deionized and ...deuterium-depleted water. It was earlier established that the swelling of Nafion in natural deionized water clearly demonstrates effects caused by the partial uncoiling of polymer fibers into the liquid volume, but no such effects were observed in deuterium-depleted water. The ab initio calculations performed in the present work show that the uncoiling of lateral Nafion chains with terminal –SO
3
H groups and the dissociation of these groups with subsequent formation of hydronium ions and
structural anionic residues are energetically favorable in the case of the contact with a sufficient amount of water molecules. The influence of these factors on the process of crystal formation on polymer substrates is studied. It is established that the effect of partial uncoiling of polymer chains indeed affects the crystallization, and does it in different ways, depending on the crystal structure. Thus, no differences between XRD patterns of crystals grown on smooth and polymer substrates are observed for the monoclinic lattice of sodium acetate trihydrate. In the case of copper sulfate (with either CuSO
4
·5H
2
O pentahydrate crystals (triclinic crystal system) or CuSO
4
·3H
2
O trihydrate crystals (monoclinic crystal system)), copper sulfate trihydrate and pentahydrate are formed on the polymer and smooth substrates, respectively. None of the studied crystals exhibited differences between smooth and polymer substrates for the supersaturated solutions based on deuterium-depleted water, and in both cases a triclinic crystal system of the CuSO
4
·5H
2
O pentahydrate precipitate is identified for the CuSO
4
aqueous solution. For sucrose, the precipitate amorphization upon the deposition onto the Nafion plate is detected. A theoretical model is proposed to explain the effect of partial polymer chain uncoiling on the growth of crystals, depending on their crystal system, unit cell parameters, and the volumetric ratio of hydrophilic and hydrophobic fragments in the molecular structure.
Optical tweezers are widely used in various fields of science and technology, such as biophysics, cytology and solid-state physics. Most of the existing optical tweezers use mirror or mirror-lens ...systems to manipulate the position of the trap. Such systems require precise alignment and do not allow the trap to be moved quickly from one arbitrary point to another due to the inertia of the mirror and lenses. We discuss acousto-optic scanning characterized by high precision and repetition rate for manipulating micro-objects using optical tweezers. Bragg diffraction of light via ultrasonic waves allows creating robust solid-state devices for precise and fast laser beam deflection. We describe a scheme of the optical tweezers with PC-driven two-dimensional scanning implemented by two sequential acousto-optical cells.
During construction of low-cost residential housing, it is necessary to use local raw materials, to increase the variety of manufactured products and to implement energy-saving technologies. Such ...technologies include, in particular, the contact-condensation (non-autoclave) technology created by V.D. Glukhovskiy and R.F. Runova. According to it, non-stable calcium hydrosilicates are produced in an isothermal reactor - a batch crystallization vessel. Then they are mixed with fine filler until attaining the moulding water content; the raw goods are compacted at the increased pressure and dried. After pressing water-resistant wares of sufficient strength are formed. The technology for separate hydrosilicate production with their further compacting considerably expands the subset of control actions over system as compared to the traditional autoclave process. The study of mutual coordination and kinetics of the composite frame formation and its probable structure simulation are among the list studied field in material science. Some scientists defined this problem as the most difficult in material science and considered implementation of theoretical modelling (replacing a real object with its analogue) as a way of its successful resolution. We make a conclusion that the examination of polystructural properties would adjust us to forecast a further development of silica-lime products.
The requirements to methods for measuring the oxide coatings thickness are formulated, allowing measurements to be carried out directly in the process of their formation in real time, which is a ...necessary condition for the controlled synthesis of coatings with desired properties. Based on a systematic approach, the existing methods for measuring the oxide coatings thickness and their metrological characteristics are analyzed. As a result, it was found that the most suitable for measuring the oxide coatings thickness during micro-arc oxidation are electrical methods, which include the method proposed by the authors based on a frequency integrating scanning transducer. The method proposed by authors allows to measure the thickness of the oxide layers directly in the process of their formation with high accuracy. This method is implemented in an intelligent automated system for the controlled synthesis of oxide coatings.
In the present paper, the influence of AC electric field on charge accumulation in the measuring cell of a flow-based system for atomic force microscope (AFM) based fishing is considered. As a ...flow-based system, a device for AFM-based fishing of low-abundant proteins has been employed. The charge is generated in a femtomolar albumin solution during its flowing through an injector of this system. We have demonstrated that application of sinusoidal electric field (100 V, 50 Hz frequency) stimulates charge accumulation in the measuring cell upon the input of protein solution at 38°C. Taking this effect into account is of importance for the development of novel highly sensitive flow-based proteomic and diagnostic systems employing AFM-based fishing, for modeling the influence of electric field on hemodynamics, and also for the development of specified theoretical models describing physicochemical properties of water and aqueous solutions.
The differential diagnosis of neoplasms of various localizations is the primary task in clinical practice of all physicians. We present a description of the case of invasion with Dirofilaria repens ...in the lung of a 68-year-old patient. In 2016 the patient was diagnosed with cancer of the left kidney and underwent a left-sided nephrectomy. During the dynamic observation in 2019, a lump was found in the left lung, which was regarded as a metastasis. An atypical SIX resection of the left lung was performed. Microscopy of the removed lump revealed the presence of a nematode of the genus Dirofilaria, presumably D. repens. The species identity of D. repens was confirmed by polymerase chain reaction using species-specific primers. It is known that the morphological identification of parasites up to the species in the surgical material presents certain difficulties and requires high professional training of the researcher. Therefore, the diagnosis of dirofilariasis in atypical localizations of nematodes in the human body is of great importance in the differentiation of malignant and benign formations, and the use of the polymerase chain reaction method can significantly increase the accuracy in establishing the final diagnosis.
.
The first high-statistics and high-resolution data set for the integrated recoil-ion energy spectrum following the
decay of
35
Ar has been collected with the WITCH retardation spectrometer located ...at CERN-ISOLDE. Over 25 million recoil-ion events were recorded on a large-area multichannel plate (MCP) detector with a time-stamp precision of 2ns and position resolution of 0.1mm due to the newly upgraded data acquisition based on the LPC Caen FASTER protocol. The number of recoil ions was measured for more than 15 different settings of the retardation potential, complemented by dedicated background and half-life measurements. Previously unidentified systematic effects, including an energy-dependent efficiency of the main MCP and a radiation-induced time-dependent background, have been identified and incorporated into the analysis. However, further understanding and treatment of the radiation-induced background requires additional dedicated measurements and remains the current limiting factor in extracting a beta-neutrino angular correlation coefficient for
35
Ar decay using the WITCH spectrometer.
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