Electrochemical activity of electroless Ni-P coatings in the hydrogen evolution reaction

The purpose of this study was investigation of the electrochemical activity of Ni-P coatings, differing in phosphorus content and structure, in the hydrogen evolution reaction (HER) and the identification of the reasons for their high activity in the reaction being studied. The coatings were deposited from an electroless nickel plating solution, the phosphorus content in the coatings (from 4.8 to 8.0 wt. %) varied by changing the pH of the solution. It was found that during cathodic polarization in 0.5 M H2SO4 additional surface activation occurs as a result of dissolution of the surface layer of the coating, removal of phosphorus from the surface layer, and development of the electrode surface. Of all the coatings studied coatings containing 4.8% phosphorus were most susceptible to cathodic activation. Coatings with a phosphorus content of 8.0% were least susceptible to cathodic activation. The similar electrochemical activity of the studied coatings (taking into account the roughness factor) in HER indicates that, as a result of cathodic polarization, the composition of the thin surface layer on which the cathodic reaction occurs is approximately the same, regardless of the initial phosphorus conten

POSSIBILITIES OF DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING IN THE DIAGNOSIS OF SPINAL CORD TUMORS

The review analyzes the data of modern literature on main methods for the diagnosis of spinal cord tumors. It reflects the possibilities of using diffusion-weighted MRI (DW-MRI), by constructing the maps of measured diffusion coefficients (ICD) and calculating the mean value of ICD in this pathology. The investigators have collected data on differential diagnosis and the assessment of the degree of malignancy of certain tumor groups on the basis of DW-MRI data. DW-MRI as compared with the data of standard T1- and T2-weighted images can serve as an additional method to diagnose spinal cord neoplasms of different nature at the preoperative stage for the determination of the volume of subsequent surgery

Structural phase transitions during annealing of proton-exchanged layers on X-cut and Z-cut lithium niobate

This work was supported by Russian Foundation For Basic Research (project № 17-43-590309 р_а)

Influence of surface treatment on the structure and properties of proton-exchanged waveguides in lithium niobate

The research was supported by RFBR (project No. 17-43-590309 р_а)

АНАЛИЗ РЕЗУЛЬТАТОВ ПРИМЕНЕНИЯ ФЛУОРЕСЦЕНТНОЙ НАВИГАЦИИ С 5-АМИНОЛЕВУЛИНОВОЙ КИСЛОТОЙ В ХИРУРГИИ ГЛИОМ ВЫСОКОЙ СТЕПЕНИ ЗЛОКАЧЕСТВЕННОСТИ

High grade gliomas (HGG) are the most aggressive primary brain tumors. The extent of resection (EOR) is proved to be an important prognostic factor in patients with HGG. There are no yet published studies on the use of fluorescent-guided resection using 5-aminolevulinic acid (5-ALA) in HGG surgery, based on the comparison of neuroimaging characteristics, intraoperative parameters and clinical outcomes. The purpose of this study was to analyze the results of 5-ALA fluorescent-guided resection in patients with HGG by comparing neuroimaging characteristics, intraoperative parameters and clinical outcomes. Material and methods. The study included 48 patients (30 men and 18 women) aged 35 to 76 years (mean age 47.3 ± 8.4 years) with newly diagnosed HGG. The patients underwent fluorescent-guided surgery that permitted the intraoperative visualization of malignant glioma tissue and supported the neurosurgeon with real-time guidance for differentiating tumor from normal brain. The Karnofsky performance status (KPS) was assessed. Results. The maximum EOR (90–98 %) was achieved in 40 (83.3 %) patients with newly diagnosed HGG. The maximum EOR was performed in 28 (58.3 %) patients with glioblastomas and in 12 (25 %) patients with grade III gliomas (p=0.408) In addition, the maximum EOR was achieved by microneurosurgical removal of 9 (18.75 %) HGGs having a volume of ≥9 cm3 and 21 (43.75 %) of HGGs with a volume<9 cm3 (p=0.029). The tumor boundaries detected by neuronavigation differed by fluorescence data in 28 (58.3 %) patients The divergence between neuronavigation and 5-ALA fluorescence was reported in 19 (39.5 %) patients with glioblastomas and in 3 (6.25 %) patients with grade III gliomas (p=0.014); and in 9 (39.5 %) and in 14 (29.1 %) patients affected with larger (≥9 cm3 ) and smaller (<9 cm3 ) tumor, respectively (p=0.677). Overall, 36 (75 %) patients experienced an improvement in their KPS score, 9 (18.75 %) remained stable, and 3 (6.25 %) declined. Conclusion. The use of 5-ALA fluorescence in surgery for HGG makes it possible to achieve the gross total resection in most cases. The localization of HGGs and their size are the most important factors in achieving maximum EOR. Key words: high grade gliomas, fluorescent navigation, 5-aminolevulinic acid, extent of tumor resection><9cm3 ) tumor, respectively (p=0.677). Overall, 36 (75 %) patients experienced an improvement in their KPS score, 9 (18.75 %) remained stable, and 3 (6.25 %) declined. Conclusion. The use of 5-ALA fluorescence in surgery for HGG makes it possible to achieve the gross total resection in most cases. The localization of HGGs and their size are the most important factors in achieving maximum EOR.  Глиомы высокой степени злокачественности (ГВЗ) представляют собой наиболее агрессивную группу первичных опухолей головного мозга. Степень резекции опухоли (СРО) является доказанным прогностическим фактором выживаемости пациентов с ГВЗ. Поиск литературных источников в базах данных Pubmed, Medline и e-Library показал отсутствие исследований по применению флуоресцентной навигации с 5-аминолевулиновой кислотой (ФН-5-АЛК) в хирургии ГВЗ, основанных на сопоставлении нейровизуализационных, интраоперационных параметров и клинических данных. Цель исследования – провести анализ результатов применения ФН-5-АЛК в хирургии ГВЗ путем изучения и сопоставления нейровизуализационных характеристик, интраоперационных параметров и клинических результатов. Материал и методы. В исследование включены 48 пациентов (30 мужчин, 18 женщин) в возрасте от 35 до 76 лет (средний возраст – 47,3 ± 8,4 года), прооперированных по поводу впервые диагностированных ГВЗ головного мозга. Определены значения СРО, особенности интраоперационной флуоресценции различных типов ГВЗ и возможность определения границ опухоли с прилежащим веществом головного мозга при использовании ФН-5-АЛК, а также изучены показатели функционального статуса пациентов по индексу Карновского. Результаты. Анализ СРО показал, что в 40 (83,3 %) случаях впервые диагностированных ГВЗ удалось достигнуть максимальной СРО (90–98 %). Максимальная СРО выполнена у 28 (58,3 %) пациентов с глиобластомами и у 12 (25 %) пациентов с глиомами III степени злокачественности (p=0,408). Кроме того, максимальная СРО достигнута при микронейрохирургическом удалении 9 (18,75 %) ГВЗ, имеющих объем ≥9 см3 , и 21 (43,75 %) ГВЗ объемом< 9 см3 (р=0,029). При сопоставлении данных ФН-5-АЛК и интраоперационной нейронавигации у 28 (58,3 %) пациентов границы опухолевой ткани не совпадали. Расхождения в полученных данных относительно границ опухолей отмечены у 19 (39,5 %) пациентов с глиобластомами и в 3 (6,25 %) случаях глиом III степени злокачественности (p=0,014), а также в 9 (18,75 %) случаях ГВЗ объемом ≥9 см3 и в 14 (29,1 %) случаях ГВЗ, имеющих объем< 9 см3 (p=0,677). Оценка функционального статуса пациентов до и после оперативного вмешательства показала следующие результаты: у 36 (75 %) пациентов отмечено улучшение функционального статуса по индексу Карновского, в 9 (18,75 %) случаях статус остался на прежнем уровне и у 3 (6,25 %) пациентов отмечено ухудшение функционального статуса. Заключение. Применение ФН-5-АЛК при микронейрохирургической резекции ГВЗ различных локализаций позволяет в большинстве случаев достигнуть тотальной СРО. Размеры ГВЗ и локализация являются важнейшими факторами в достижении максимальной СРО

Contrasting origin of B chromosomes in two cervids (Siberian roe deer and grey brocket deer) unravelled by chromosome-specific DNA sequencing

Abstract Background B chromosomes are dispensable and variable karyotypic elements found in some species of animals, plants and fungi. They often originate from duplications and translocations of host genomic regions or result from hybridization. In most species, little is known about their DNA content. Here we perform high-throughput sequencing and analysis of B chromosomes of roe deer and brocket deer, the only representatives of Cetartiodactyla known to have B chromosomes. Results In this study we developed an approach to identify genomic regions present on chromosomes by high-throughput sequencing of DNA generated from flow-sorted chromosomes using degenerate-oligonucleotide-primed PCR. Application of this method on small cattle autosomes revealed a previously described KIT gene region translocation associated with colour sidedness. Implementing this approach to B chromosomes from two cervid species, Siberian roe deer (Capreolus pygargus) and grey brocket deer (Mazama gouazoubira), revealed dramatically different genetic content: roe deer B chromosomes consisted of two duplicated genomic regions (a total of 1.42-1.98 Mbp) involving three genes, while grey brocket deer B chromosomes contained 26 duplicated regions (a total of 8.28-9.31 Mbp) with 34 complete and 21 partial genes, including KIT and RET protooncogenes, previously found on supernumerary chromosomes in canids. Sequence variation analysis of roe deer B chromosomes revealed a high frequency of mutations and increased heterozygosity due to either amplification within B chromosomes or divergence between different Bs. In contrast, grey brocket deer B chromosomes were found to be more homogeneous and resembled autosomes in patterns of sequence variation. Similar tendencies were observed in repetitive DNA composition. Conclusions Our data demonstrate independent origins of B chromosomes in the grey brocket and roe deer. We hypothesize that the B chromosomes of these two cervid species represent different stages of B chromosome sequences evolution: probably nascent and similar to autosomal copies in brocket deer, highly derived in roe deer. Based on the presence of the same orthologous protooncogenes in canids and brocket deer Bs we argue that genomic regions involved in B chromosome formation are not random. In addition, our approach is also applicable to the characterization of other evolutionary and clinical rearrangements

ВОЗМОЖНОСТИ ДИФФУЗИОННО-ВЗВЕШЕННОЙ МРТ В ДИФФЕРЕНЦИАЛЬНОЙ ДИАГНОСТИКЕ СТЕПЕНИ ЗЛОКАЧЕСТВЕННОСТИ МЕНИНГИОМ ГОЛОВНОГО МОЗГА

Methods of diffusion-weighted magnetic resonance imaging (DW MRI) provides information on the microstructural state of various tissues and organs. Also, a diffusion-weighted image (DWI) obtained using DW MRI applied to the differential diagnosis of benign and malignant tumors. Purpose – to compare the values obtained ADC meningiomas with cell density and proliferative activity index Ki67 tumor. Material and methods. The study included DW MRI program with 37 patients for brain meningiomas. ADC was calculated on DWI with a maximum diameter of meningioma, in the area of interest have not been included cystic and necrotic areas of the tumor. When meningiomas morphological study assessed the degree of malignancy according to WHO classification, the index of Ki67 proliferative activity and cell density in tumor tissue. Results. In most typical cases detected (MI) and atypical (MII) meningiomas – at 37.8 % and 56.7 % of patients, respectively. Anaplastic (MIII) meningioma verified in 5.5 % of patients. The average value for meningiomas ADC MI was 1375,5 ± 197,5 mm2 /s. ADC for meningiomas MII and MIII costavili 1113.1 ± 180 mm2 /sec and 689 ± 31.1 mm2 /s, respectively. Statistically significant differences between the mean values obtained by comparing ADC meningiomas MI and MIII (p=0.008) and meningiomas MII and MIII (p=0.012). No significant differences between the cell density was not detected meningiomas (p=0,834, p=0,684 p=0,766 respectively for the MI/MII, MII/MIII and MI/MIII). Statistically significant differences between the values of Ki67 index were found when comparing the groups meningiomas MI and MIII (p=0.002) and MII and MIII (p=0.007). ADC between index values and proliferative activity of Ki67, expressed marked correlation (r=-0,699, p=0,001). Conclusion. DW MRI and ADC maps can be used as an additional non-invasive method of differential diagnosis brain meningioma gradation. Методика диффузионно-взвешенной магнитно-резонансной томографии (ДВ МРТ) позволяет получить информацию о микроструктурном состоянии различных тканей и органов. Также диффузионно-взвешенные изображения (ДВИ), получаемые с помощью ДВ МРТ, применяются с целью дифференциальной диагностики доброкачественных и злокачественных опухолей. Цель исследования – сопоставить полученные значения ИКД менингиом с клеточной плотностью и индексом пролиферативной активности опухоли Ki67. Материал и методы. В исследование включены магнитнорезонансные томограммы с ДВИ, выполненные 37 пациентам по поводу менингиом головного мозга. Измеряемый коэффициент диффузии (ИКД) вычислялся на ДВИ с наибольшим диаметром менингиомы, в область интереса не были включены кистозные и некротические зоны опухоли. При морфологическом исследовании менингиом оценивалась степень злокачественности по классификации ВОЗ, значение индекса пролиферативной активности Ki67 и клеточная плотность в опухолевой ткани. Результаты. В большинстве случаев выявлялись типические (MI) и атипические (MII) менингиомы – у 37,8 и 56,7 % пациентов соответственно. Анапластические (MIII) менингиомы верифицированы у 5,5 % пациентов. Среднее значение ИКД для менингиом MI составило 1375,5 ± 197,5 мм2 /сек. ИКД для менингиом MII и MIII cоставили 1113,1 ± 180 мм2 /сек и 689 ± 31,1 мм2 /сек соответственно. Значимые различия между средними значениями ИКД получены при сравнении менингиом МI и MIII (р=0,008) и менингиом MII и MIII (р=0,012). Достоверных различий между клеточной плотностью менингиом выявлено не было (для MI/MII, MII/MIII и MI/MIII – p=0,834, p=0,684, p=0,766 соответственно). Значимые различия между значениями индекса Ki67 обнаружены при сравнении групп менингиом MI и MIII (р=0,002), а также MII и MIII (р=0,007). Между ИКД и значениями индекса пролиферативной активности Ki67 отмечена выраженная корреляционная зависимость (r = –0,699, p=0,001). Заключение. Методика ДВ МРТ с подсчетом ИКД может быть использована в качестве дополнительного неинвазивного метода дифференциальной диагностики степени злокачественности менингиом головного мозга.

Contrasting origin of B chromosomes in two cervids (Siberian roe deer and grey brocket deer) unravelled by chromosome-specific DNA sequencing.

BACKGROUND: B chromosomes are dispensable and variable karyotypic elements found in some species of animals, plants and fungi. They often originate from duplications and translocations of host genomic regions or result from hybridization. In most species, little is known about their DNA content. Here we perform high-throughput sequencing and analysis of B chromosomes of roe deer and brocket deer, the only representatives of Cetartiodactyla known to have B chromosomes. RESULTS: In this study we developed an approach to identify genomic regions present on chromosomes by high-throughput sequencing of DNA generated from flow-sorted chromosomes using degenerate-oligonucleotide-primed PCR. Application of this method on small cattle autosomes revealed a previously described KIT gene region translocation associated with colour sidedness. Implementing this approach to B chromosomes from two cervid species, Siberian roe deer (Capreolus pygargus) and grey brocket deer (Mazama gouazoubira), revealed dramatically different genetic content: roe deer B chromosomes consisted of two duplicated genomic regions (a total of 1.42-1.98 Mbp) involving three genes, while grey brocket deer B chromosomes contained 26 duplicated regions (a total of 8.28-9.31 Mbp) with 34 complete and 21 partial genes, including KIT and RET protooncogenes, previously found on supernumerary chromosomes in canids. Sequence variation analysis of roe deer B chromosomes revealed a high frequency of mutations and increased heterozygosity due to either amplification within B chromosomes or divergence between different Bs. In contrast, grey brocket deer B chromosomes were found to be more homogeneous and resembled autosomes in patterns of sequence variation. Similar tendencies were observed in repetitive DNA composition. CONCLUSIONS: Our data demonstrate independent origins of B chromosomes in the grey brocket and roe deer. We hypothesize that the B chromosomes of these two cervid species represent different stages of B chromosome sequences evolution: probably nascent and similar to autosomal copies in brocket deer, highly derived in roe deer. Based on the presence of the same orthologous protooncogenes in canids and brocket deer Bs we argue that genomic regions involved in B chromosome formation are not random. In addition, our approach is also applicable to the characterization of other evolutionary and clinical rearrangements

The sterlet sturgeon genome sequence and the mechanisms of segmental rediploidization.

Sturgeons seem to be frozen in time. The archaic characteristics of this ancient fish lineage place it in a key phylogenetic position at the base of the ~30,000 modern teleost fish species. Moreover, sturgeons are notoriously polyploid, providing unique opportunities to investigate the evolution of polyploid genomes. We assembled a high-quality chromosome-level reference genome for the sterlet, Acipenser ruthenus. Our analysis revealed a very low protein evolution rate that is at least as slow as in other deep branches of the vertebrate tree, such as that of the coelacanth. We uncovered a whole-genome duplication that occurred in the Jurassic, early in the evolution of the entire sturgeon lineage. Following this polyploidization, the rediploidization of the genome included the loss of whole chromosomes in a segmental deduplication process. While known adaptive processes helped conserve a high degree of structural and functional tetraploidy over more than 180 million years, the reduction of redundancy of the polyploid genome seems to have been remarkably random

Genome of the Komodo dragon reveals adaptations in the cardiovascular and chemosensory systems of monitor lizards

Monitor lizards are unique among ectothermic reptiles in that they have high aerobic capacity and distinctive cardiovascular physiology resembling that of endothermic mammals. Here, we sequence the genome of the Komodo dragon Varanus komodoensis, the largest extant monitor lizard, and generate a high-resolution de novo chromosome-assigned genome assembly for V. komodoensis using a hybrid approach of long-range sequencing and single-molecule optical mapping. Comparing the genome of V. komodoensis with those of related species, we find evidence of positive selection in pathways related to energy metabolism, cardiovascular homoeostasis, and haemostasis. We also show species-specific expansions of a chemoreceptor gene family related to pheromone and kairomone sensing in V. komodoensis and other lizard lineages. Together, these evolutionary signatures of adaptation reveal the genetic underpinnings of the unique Komodo dragon sensory and cardiovascular systems, and suggest that selective pressure altered haemostasis genes to help Komodo dragons evade the anticoagulant effects of their own saliva. The Komodo dragon genome is an important resource for understanding the biology of monitor lizards and reptiles worldwide