Mosaic Block Research Articles

Влияние ионной имплантации на свойства чугуна, используемого в конструкциях горнодобывающих машин и аппаратов

Introduction. Cast iron is a widely used material in mechanical engineering, mining and other industries. Modification of the surface properties of cast iron by ion implantation is of great interest. Research methods and materials. Samples of cast iron before and after implantation with C+, B+, N+ ions with dose D = 1017 ions/cm2 and energy of 40 keVwere taken for research. All samples were tested for wear resistance; microhardness was also measured and X-ray analysis was performed. Research results. It is shown that cast iron samples after ion implantation had higher wear resistance and microhardness in comparison with the initial state. The increase in hardness of all samples is apparently associated with the presence of a large number of specific radiation defects and the formation of dispersed phases (nitrides, borides, carbides). Discussion of the research results. The study of micro-hardness was carried out to determine the depth of the hardened layer after ion implantation with C+ , B+ , and N+ ions. The highest micro-hardness was detected at the surface of the sample after irradiation with N + ions. The lowest micro-hardness was obtained by B+ ions. X-ray analysis of cast iron samples after implantation by C+ , B+ , and N+ ions with dose D = 1017 ions/cm2 was the fine structure are observed. Conclusion. Ion implantation of cast iron with C+, B+, N+ ions has shown that irradiation leads to: Increased wear resistance of the material; A significant increase in micro-hardness; Changes in the fine structure of the implanted cast iron (mosaic block size and average dislocation density) and the formation of carbides, borides, and nitrides. Resume. The results of the research show that ion implantation of cast iron can significantly increase the wear resistance of various units of machines (parts) and other mining equipment, which ultimately increases their service life. Suggestions for practical application and direction of future research. The shown results allow us to propose the method of ion implantation as a hardening treatment of parts made of cast iron used, in particular, in the mining industry. In order to develop ion implantation as one of the hardening technologies, it would be advisable to continue studying various physical and chemical properties (for example, corrosion resistance) after exposure to ion implantation.

Use of Natural Flake Graphite in the Calibration of Instrumental Research Methods

The size of mosaic blocks along the graphite layers (that is, the average diameter of crystallites in the basal plane) was determined by two methods for specially made model materials based on narrow fractions of flake graphite powders and milled pyrographite with lamellar particles. The first method consisted in the calculation of mosaic block sizes from a minimum of the temperature dependence of electrical conductivity using an empirical law according to Mason; the second method based on mathematical modeling used the values of the magnetoresistance of carbon materials at temperatures of 80 and 300 K. The correspondence between the sizes of mosaic blocks calculated by these methods along the graphite layers in the considered materials was shown. A correction for the lamellar shape of graphite crystallites was determined to calculate the sizes of mosaic blocks in the direction perpendicular to the graphite layers from the 002 peak broadening in the diffraction pattern.

GaAs hetero-epitaxial layers grown by MOVPE on exactly-oriented and off-cut (1 1 1)Si: Lattice tilt, mosaicity and defects content

Integration of III-V devices with Si-photonics and fabrication of monolithic III-V/Si tandem solar cells require the heteroepitaxy of III-V compounds on Si. We report on the lattice tilt, mosaicity and defects content of relaxed GaAs grown by MOVPE on exactly-oriented and 4°-offcut (111)Si. Thin GaAs single-layers grown at 400 °C and annealed at 700 °C show ∼ 3 × 108 cm−2 density of surface pinholes. Double-layer samples were obtained by GaAs overgrowth at 700 °C. GaAs epilayers are tilted by (0.05–0.14)° with respect to Si. Rotational twins were observed in X-ray diffraction (XRD) pole figures: the most abundant ones originate from 60°-rotation of GaAs around the 1¯1¯1¯ growth direction and are identified as micro-twins along the GaAs/Si hetero-interface. Twins obtained by rotations around the 1¯1¯1, 11¯1¯, and 1¯11¯ directions or by combined rotations around the growth direction and one of the former, were also observed. The GaAs mosaicity and block size were studied through high-resolution XRD intensity mapping: for single-layer samples crystal blocks are ascribed to 3–5 nm thin micro-twins, whose size does not change upon annealing. In double-layer samples thicker (32–35 nm) micro-twins occur. GaAs samples grown on offcut (111)Si show less rotational twins but a reduced mosaic block size with respect to exactly-oriented Si.

Observation of threading dislocations and misfit dislocation half-loops in GaN/AlGaN heterostructures grown on Si using electron channeling contrast imaging

We implemented invisibility criterion and black–white contrast orientation analysis into low-tilt electron channeling contrast imaging (ECCI) for dislocation-type discrimination in GaN and AlGaN layers grown on a Si(111) substrate. Our ECCI and x-ray diffraction (XRD) analysis attained consistent threading dislocation densities for GaN and AlGaN grown on Si, but demonstrated drastic discrepancy in the percentage of edge-type dislocations, potentially due to the lack of appropriate consideration of mixed-type (a→+c→) dislocations in XRD. Further ECCI analysis of GaN/AlGaN heterointerface revealed mixed-type (a→+c→) dislocation half-loops and dislocation bending due to compressive strain relaxation, validating that not all the dislocations originated from the mosaic or columnar structure. As a result, XRD analysis based on the mosaic block model does not give reliable edge-to-screw dislocation ratio. The observation of classic van der Merwe–Matthews-type dislocation half-loop nucleation and dislocation gliding could be associated with potential GaN/AlGaN optoelectronic device degradation issues.

Analysis and Mapping of Detailed Inner Information of Crystalline Grain by Wavelength-Resolved Neutron Transmission Imaging with Individual Bragg-Dip Profile-Fitting Analysis

As a new method for evaluating single crystals and oligocrystals, pulsed neutron Bragg-dip transmission analysis/imaging method is being developed. In this study, a single Bragg-dip profile-fitting analysis method was newly developed, and applied for analyzing detailed inner information in a crystalline grain position-dependently. In the method, the spectrum profile of a single Bragg-dip is analyzed at each position over a grain. As a result, it is expected that changes in crystal orientation, mosaic spread angle and thickness of a perfect crystal can be evaluated from the wavelength, the width and the integrated intensity of the Bragg-dip, respectively. For confirming this effectiveness, the method was applied to experimental data of position-dependent Bragg-dip transmission spectra of a Si-steel plate consisting of oligocrystals. As a result, inner information of multiple crystalline grains could be visualized and evaluated. The small change in crystal orientation in a grain, about 0.4°, could be observed by imaging the Bragg-dip wavelengths. By imaging the Bragg-dip widths, both another grain and mosaic block in a grain were detected. Furthermore, imaging results of the integrated intensities of Bragg-dips were consistent with the results of Bragg-dip width imaging. These small crystallographic changes have not been observed and visualized by previous Bragg-dip analysis methods.

Multi‐camera traffic scene mosaic based on camera calibration

Recently, the traffic application based on vision in the single traffic-monitoring scene has been widely studied and developed. However, cross-regional research is still in its infancy. In order to help solve the application of cross-regional traffic surveillance scenarios, this paper proposes a more reliable and accurate road scene mosaic method under multi-camera surveillance. The mosaic road panorama contains physical information, which can be used to achieve a cross-regional measurement. It also lays the foundation for vehicle spatial location, vehicle speed and traffic incident detection across regions. First, the mapping relationship between the three-dimensional sub-world coordinates and their corresponding two-dimensional image coordinates is established by camera calibration. Second, the projection transformation relationship between two cameras is established by two sub-world coordinate systems and their common information. Finally, we use the proposed inverse projection idea and translation vector relationship to complete the mosaic of two traffic-monitoring road scenes. The experimental results show that the camera calibration accuracy can reach more than 97% in a single scene. The measurement accuracy of the mosaic block is over 95%. The experimental results show that the proposed method has a higher accuracy, which has great value in related theoretical research and practical applications.

Effect of the lattice mismatch on threading dislocations in heteroepitaxial GaN layers revealed by X-ray diffraction

In this study, structural investigations of the mismatched gallium nitride (GaN) layers grown on SiC, Al2O3 and Si substrate, were performed employing x-ray diffraction techniques. The resulted threading dislocation density evolved from the lattice mismatch, as a consequence of the strain relaxation processes, was quantified in two independent ways: firstly, using the mosaic block model, which takes into account peak width and, secondly, using the diffuse scattering model, which consider only the tails of the rocking curves. Both models indicated the close relationship between the amount of dislocations and the lattice mismatch that plays a fundamental role in TDs’ generation. To gain further insights regarding threading dislocations, grazing incidence x-ray diffraction was employed to obtain the absorption profiles of the x-rays. Although these profiles encompass the contributions of both sample absorption and dislocations, we decoupled these two effects in the framework of the dynamical theory of diffraction, showing that the existence of dislocations governs different power law dependencies for the experimental absorption profiles. Moreover, the absorption profiles bring information regarding the uniformity of the dislocations along the z-axis, revealing a uniform distribution along the z-axis for thin layer, while for the thick layer an annihilation of the dislocations was taking place. In addition, photoluminescence peaks found at 3.41 eV, 3.39 eV and 3.35 eV correspond to near band-edge (NBE) and ultraviolet donor-acceptor pair (DAP) transition. Significant changes of their intensity ratio, as well as the additional broadening of E2 (high) Raman peak confirm the presence of TDs in the investigated GaN thin films.

Innervation Anomalies and Interneural Anastomoses: Is There Clinical Relevance or Not?

Failed block could be one of the adverse results of the conductive anaesthesia. There are situations, when in seemingly perfect technique of the block, properly chosen drug, dosage, adjuvant – the block is not achieved (it does not occur or is incomplete or so-called “mosaic block” occurs). It is necessary to remember about atypical or abnormal nerves branching, possible interneural anastomoses, when looking for the possible cause of it. Information about most common types of interneural anastomosis of arm’s and leg’s long nerves is presented in this article. Knowledge of possible abnormal neural innervation can provide an understanding of inefficacy of some simple blocks, decrease amount of mistakes in data interpretation, that was obtained during electroneuromyographic (ENMG) investigations, improve understanding of clinical pattern in the peripheral nerve injuries, that form anastomosis.

Intelligibility of English Mosaic Speech: Comparison between Native and Non-Native Speakers of English

Mosaic speech is degraded speech that is segmented into time × frequency blocks. Earlier research with Japanese mosaic speech has shown that its intelligibility is almost perfect for mosaic block durations (MBD) up to 40 ms. The purpose of the present study was to investigate the intelligibility of English mosaic speech, and whether its intelligibility would vary if it was compressed in time, preserved, or stretched in time. Furthermore, we investigated whether intelligibility differed between native and non-native speakers of English. English (n = 19), Indonesian (n = 19), and Chinese (n = 20) listeners participated in an experiment, in which the mosaic speech stimuli were presented, and they had to type what they had heard. The results showed that compressing or stretching the English mosaic speech resulted in similar trends in intelligibility among the three language groups, with some exceptions. Generally, the intelligibility for MBDs of 20 and 40 ms after preserving/stretching was higher, and decreased beyond MBDs of 80 ms after stretching. Compression also lowered intelligibility. This suggests that humans can extract new information from individual speech segments of about 40 ms, but that there is a limit to the amount of linguistic information that can be conveyed within a block of about 40 ms or below.

4165 Mechanisms of Prophage-Mediated Virulence Driving Community-Acquired MRSA Contagion

OBJECTIVES/GOALS: We recently identified a CA-MRSA strain in Brooklyn, New York (USA300-BKV) causing an outbreak of severe skin infections in predominantly healthy children. The evolution of USA300-BKV included acquisition of a novel prophage, and our objective is to identify the prophage-encoded gene(s) and mechanism responsible for increased bacterial virulence. METHODS/STUDY POPULATION: We deleted candidate genes from a novel mosaic block of phage-encoded genes in USA300-BKV that have been shown to enhance virulence in a murine skin infection model. Deletion mutants and complemented clones will be evaluated in vivo to identify culprit genes and determine the effect of lineage-specific genetic variation on the phenotype. Complementary studies include a comprehensive characterization of phage and bacterial genes expressed during lysogeny in vitro using RNA sequencing (RNA-Seq), and in vivo using a targeted approach focusing on known bacterial virulence and phage lytic pathways as well as candidate genes identified by in vitro studies. RESULTS/ANTICIPATED RESULTS: Comparison of otherwise isogenic lab strains showed that the mosaic block of phage genes present in USA300-BKV enhance skin abscess size in mice, confirming previous results. As this region of the phage, named mΦ11, does not contain known toxin genes, we hypothesize that mΦ11 modulates expression of bacterial host genes to enhance virulence. Thus, transcriptional profiles of CA-MRSA containing mΦ11 and selected deletion mutants are expected to reveal changes in known or novel virulence factors compared to controls. Candidate regulators specific to the mosaic block include an adenine methyltransferase linked to changes in global gene expression of other bacterial species. DISCUSSION/SIGNIFICANCE OF IMPACT: Our results will broaden scientific understanding of phage-bacterial interactions and determine the mechanisms by which phage impact virulence independent from toxin gene carriage. Identification of phage-encoded gene(s) enhancing CA-MRSA contagion will inform surveillance efforts and identify novel therapeutic targets.

Evolution of strain across the magnetostructural phase transition in epitaxial FeRh films on different substrates

We present a detailed x-ray diffraction study of the structural evolution of epitaxial FeRh films across the temperature-driven phase transition between antiferromagnetic and ferromagnetic order. FeRh films grown onto MgO, W/MgO, and $\mathrm{A}{\mathrm{l}}_{2}{\mathrm{O}}_{3}$ substrates show qualitatively different lattice distortions (tetragonal vs rhombohedral), while keeping a sharp transition above room temperature. Temperature-dependent x-ray reciprocal space mapping reveals the phase-specific crystal structure, giving access to both in-plane and out-of-plane lattice parameters and crystalline coherence lengths across different stages of the phase transition. Diffuse x-ray scattering from relaxed films is treated via a mosaic block model, which provides a robust data fitting scheme. It is found that the ferromagnetic phase fraction can stand a larger amount of strain before completely annihilating and transitioning to the antiferromagnetic phase upon cooling, as compared to heating. This is related to the distinct magnetic exchange correlations in the antiferromagnetic and ferromagnetic parent phases.

Cone-in-cone structure: New data

Research subject . The article presents the results of investigating calcite lenses with a cone-in-cone structure from Middle Devonian clay terrigenous deposits in the Middle Timan. Methods. The investigation of petrographic thin-sections was carried out using a polarizing microscope Nikon eclipse LV100 ND equipped with a Nikon DS Fi2 camera. Polished sections etched with HCl were examined using a scanning electronic microscope JSM-6400 Jeol with a power dispersive spectrometer ISIS Link and a wave spectrometer Microspec. The decomposition of carbonates and the measurement of isotope carbon composition in the mode of continuous helium stream were carried out using a ThermoFisher Scientific analytical complex. Results. It is established that the investigated calcite bodies consists of mosaic block crystals having a drusy structure. Calcite is characterized by abnormally low values S 13 C carb - up to -23.5 %o. Clay films and soapstone inclusions were studied in detail. The formation mechanism of the saw-tooth profile of the upper bound of these inclusions was determined, which consists in the local substitution of alumosilicates with calcite under the maintenance of their relic layered texture. Conclusions. A new version of the crystallization model of carbonate body genesis with a cone-in-cone structure is proposed.

Reduction in crystalline quality anisotropy for non-polar a-plane GaN directly grown on titanium patterned sapphire substrate

Nonpolar a-plane GaN films were directly grown on titanium patterned sapphire substrates (Ti-PSS) by metalorganic chemical vapor deposition (MOCVD). It is demonstrated that the GaN film grown on Ti-PSS has superior surface quality and less surface pits than that on flat sapphire substrate. More importantly, the anisotropic behavior of the X-ray rocking curve-full width at half maximum values for the on-axis reflections were significantly improved. It is found that, the increased mosaic block size along m-direction could be the main reason for the reduction in the crystalline quality anisotropy. This work provides a simple and effective method to improve the crystal quality of non-polar GaN films.

A Thioredoxin Domain-Containing Protein Interacts with Pepino mosaic virus Triple Gene Block Protein 1.

Pepino mosaic virus (PepMV) is a mechanically-transmitted tomato pathogen of importance worldwide. Interactions between the PepMV coat protein and triple gene block protein (TGBp1) with the host heat shock cognate protein 70 and catalase 1 (CAT1), respectively, have been previously reported by our lab. In this study, a novel tomato interactor (SlTXND9) was shown to bind the PepMV TGBp1 in yeast-two-hybrid screening, in vitro pull-down and bimolecular fluorescent complementation (BiFC) assays. SlTXND9 possesses part of the conserved thioredoxin (TRX) active site sequence (W__PC vs. WCXPC), and TXND9 orthologues cluster within the TRX phylogenetic superfamily closest to phosducin-like protein-3. In PepMV-infected and healthy Nicotiana benthamiana plants, NbTXND9 mRNA levels were comparable, and expression levels remained stable in both local and systemic leaves for 10 days post inoculation (dpi), as was also the case for catalase 1 (CAT1). To localize the TXND9 in plant cells, a polyclonal antiserum was produced. Purified α-SlTXND9 immunoglobulin (IgG) consistently detected a set of three protein bands in the range of 27–35 kDa, in the 1000 and 30,000 g pellets, and the soluble fraction of extracts of healthy and PepMV-infected N. benthamiana leaves, but not in the cell wall. These bands likely consist of the homologous protein NbTXND9 and its post-translationally modified derivatives. On electron microscopy, immuno-gold labelling of ultrathin sections of PepMV-infected N. benthamiana leaves using α-SlTXND9 IgG revealed particle accumulation close to plasmodesmata, suggesting a role in virus movement. Taken together, this study highlights a novel tomato-PepMV protein interaction and provides data on its localization in planta. Currently, studies focusing on the biological function of this interaction during PepMV infection are in progress.

Diversity of Mosaic pbp2x Families in Penicillin-Resistant Streptococcus pneumoniae from Iran and Romania.

ABSTRACTPenicillin-resistant Streptococcus pneumoniae strains are found at high rates in Romania and Iran. The mosaic structure of PBP2x was investigated in 9 strains from Iran and in 15 strains from Romania to understand their evolutionary history. Mutations potentially important for β-lactam resistance were identified by comparison of the PBP2x sequences with the sequence of the related PBP2x of reference penicillin-sensitive S. mitis strains. Two main PBP2x mosaic gene families were recognized. Eight Iranian strains expressed PBP2x variants in group 1, which had a mosaic block highly related to PBP2x of the Spain23F-1 clone, which is widespread among international penicillin-resistant S. pneumoniae clones. A second unique PBP2x group was observed in Romanian strains; furthermore, three PBP2x single mosaic variants were found. Sequence blocks of penicillin-sensitive strain S. mitis 658 were common among PBP2x variants from strains from both countries. Each PBP2x group contained specific signature mutations within the transpeptidase domain, documenting the existence of distinct mutational pathways for the development of penicillin resistance.

Formation and mosaicity of coccolith segment calcite of the marine algae Emiliania huxleyi.

Coccolithophores belong to the most abundant calcium carbonate mineralizing organisms. Coccolithophore biomineralization is a complex and highly regulated process, resulting in a product that strongly differs in its intricate morphology from the abiogenically produced mineral equivalent. Moreover, unlike extracellularly formed biological carbonate hard tissues, coccolith calcite is neither a hybrid composite, nor is it distinguished by a hierarchical microstructure. This is remarkable as the key to optimizing crystalline biomaterials for mechanical strength and toughness lies in the composite nature of the biological hard tissue and the utilization of specific microstructures. To obtain insight into the pathway of biomineralization of Emiliania huxleyi coccoliths, we examine intracrystalline nanostructural features of the coccolith calcite in combination with cell ultrastructural observations related to the formation of the calcite in the coccolith vesicle within the cell. With TEM diffraction and annular dark-field imaging, we prove the presence of planar imperfections in the calcite crystals such as planar mosaic block boundaries. As only minor misorientations occur, we attribute them to dislocation networks creating small-angle boundaries. Intracrystalline occluded biopolymers are not observed. Hence, in E.huxleyi calcite mosaicity is not caused by occluded biopolymers, as it is the case in extracellularly formed hard tissues of marine invertebrates, but by planar defects and dislocations which are typical for crystals formed by classical ion-by-ion growth mechanisms. Using cryo-preparation techniques for SEM and TEM, we found that the membrane of the coccolith vesicle and the outer membrane of the nuclear envelope are in tight proximity, with a well-controlled constant gap of ~4nm between them. We describe this conspicuous connection as a not yet described interorganelle junction, the "nuclear envelope junction". The narrow gap of this junction likely facilitates transport of Ca2+ ions from the nuclear envelope tothe coccolith vesicle. On the basis of our observations, we propose that formation of the coccolith utilizes the nuclear envelope-endoplasmic reticulum Ca2+ -store of the cell for the transport of Ca2+ ions from the external medium to the coccolith vesicle and that E.huxleyi calcite forms by ion-by-ion growth rather than by a nanoparticle accretion mechanism.

Tectonic insights into the Arabian-African region inferred from a comprehensive examination of satellite gravity big data

Abstract Modern satellite gravimetry is now considered one of the most powerful and effective instrument for regional tectono-geodynamic zonation. Satellite gravity observations clearly fit the definition of 'big data' because of their volume and variety. The Arabian – NE African region discussed in this article has intricate geodynamic features including active rift zones, high seismic activity and collision processes, a rich structural pattern made up of the mosaic block system of continental and oceanic crusts of different ages, as well as several of the greatest gravity anomalies and complex magnetic anomaly mosaics. This region also has the world's main hydrocarbon resources and a vast number of other economic deposits. A comprehensive analysis of these satellite derived gravity data were used to construct a series of new maps that localize the key properties of the lithosphere of the region. A careful examination of numerous geological sources and their combined inspection with satellite derived gravity and other geophysical data resulted in this new integrated tectonic map of the Arabian-African region. An analysis of the series of gravity map transformations and certain geological indicators document the significant geodynamic features of the region.

Long Persistence of a Streptococcus pneumoniae 23F Clone in a Cystic Fibrosis Patient.

Streptococcus pneumoniae isolates of serotype 23F with intermediate penicillin resistance were recovered on seven occasions over a period of 37months from a cystic fibrosis patient in Berlin. All isolates expressed the same multilocus sequence type (ST), ST10523. The genome sequences of the first and last isolates, D122 and D141, revealed the absence of two phage-related gene clusters compared to the genome of another ST10523 strain, D219, isolated earlier at a different place in Germany. Genomes of all three strains carried the same novel mosaic penicillin-binding protein (PBP) genes, pbp2x, pbp2b, and pbp1a; these genes were distinct from those of other penicillin-resistant S.pneumoniae strains except for pbp1a of a Romanian S.pneumoniae isolate. All PBPs contained mutations that have been associated with the penicillin resistance phenotype. Most interestingly, a mosaic block identical to an internal pbp2x sequence of ST10523 was present in pbp2x of Streptococcus mitis strain B93-4, which was isolated from the same patient. This suggests interspecies gene transfer from S.pneumoniae to S.mitis within the host. Nearly all genes expressing surface proteins, which represent major virulence factors of S.pneumoniae and are typical for this species, were present in the genome of ST10523. One exception was the hyaluronidase gene hlyA, which contained a 12-nucleotide deletion within the promoter region and an internal stop codon. The lack of a functional hyaluronidase might contribute to the ability to persist in the host for an unusually long period of time. IMPORTANCEStreptococcus pneumoniae is a common resident in the human nasopharynx. However, carriage can result in severe diseases due to a unique repertoire of pathogenicity factors that are rare in closely related commensal streptococci. We investigated a penicillin-resistant S.pneumoniae clone of serotype 23F isolated from a cystic fibrosis patient on multiple occasions over an unusually long period of over 3years that was present without causing disease. Genome comparisons revealed an apparent nonfunctional pneumococcus-specific gene encoding a hyaluronidase, supporting the view that this enzyme adds to the virulence potential of the bacterium. The 23F clone harbored unique mosaic genes encoding penicillin resistance determinants, the product of horizontal gene transfer involving the commensal S.mitis as donor species. Sequences identical to one such mosaic gene were identified in an S.mitis strain from the same patient, suggesting that in this case S.pneumoniae played the role of donor.

Підвищення захисту бойових броньованих машин від ураження 12,7-мм кулями Б-32

Надані результати числового моделювання процесу пробиття захисних керамічних елементів з різною конструкцією. Розроблені конструкції двох типів, що були виготовлені й пройшли натурні балістичні випробування 12,7-мм кулями Б-32: блок з керамічними циліндричними елементами типу «сфера-сфера» на полімерній зв’язці та мозаїчний блок, який складається з плоских керамічних елементів. Балістичні випробування підтвердили ефективність розроблених захисних керамічних елементів для захисту бойових броньованих машин від 12,7-мм куль Б-32.

Inefficient epidural block and frequency of its development during perioperative anesthesia in oncosurgery

The dependence of the efficiency of epidural analgesia on a number of medical factors, such as experience and qualification of doctors and appropriate medical equipment was studied in this article. It is shown that epidural catheter design can significantly affect the quality of perioperative anesthesia in cancersurgery: the frequency of epidural veins perforation, paresthesia, development of mosaic epidural block is lower when using epidural catheter with six lateral holes versus catheter with three lateral holes.