Publications by authors named "Alexander Yakovlev"

59 Publications

Study of Forward and Backward Modes in Double-Sided Dielectric-Filled Corrugated Waveguides.

Sensors (Basel) 2021 Sep 20;21(18). Epub 2021 Sep 20.

Division of Electromagnetic Engineering, KTH Royal Institute of Technology, 114 28 Stockholm, Sweden.

This work studies the propagation characteristics of a rectangular waveguide with aligned/misaligned double-sided dielectric-filled metallic corrugations. Two modes are found to propagate in the proposed double-sided configuration below the hollow-waveguide cutoff frequency: a quasi-resonant mode and a backward mode. This is in contrast to the single-sided configuration, which only allows for backward propagation. Moreover, the double-sided configuration can be of interest for waveguide miniaturization on account of the broader band of its backward mode. The width of the stopband between the quasi-resonant and backward modes can be controlled by the misalignment of the top and bottom corrugations, being null for the glide-symmetric case. The previous study is complemented with numerical results showing the impact of the height of the corrugations, as well as the filling dielectric permittivity, on the bandwidth and location of the appearing negative-effective-permeability band. The multi-modal transmission-matrix method has also been employed to estimate the rejection level and material losses in the structure and to determine which port modes are associated with the quasi-resonant and backward modes. Finally, it is shown that glide symmetry can advantageously be used to reduce the dispersion and broadens the operating band of the modes.
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http://dx.doi.org/10.3390/s21186293DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8472892PMC
September 2021

Validation of the Generalized Anxiety Disorder-7 (GAD-7) in Russian people with epilepsy.

Epilepsy Behav 2021 10 6;123:108269. Epub 2021 Sep 6.

Moscow Research and Clinical Center for Neuropsychiatry, Moscow, Russian Federation; Pirogov Russian National Research Medical University, Moscow, Russian Federation.

Objective: To assess the capacity of Generalized Anxiety Disorder-7 (GAD-7) to detect anxiety disorders in a Russian sample of patients with epilepsy and to validate this instrument for rapid screening of anxiety in these patients.

Methods: Study included 233 patients with epilepsy, both inpatients and outpatients. For all patients Mini-International Neuropsychiatric Interview was conducted as a gold standard for diagnosis of mental disorders. All patients also completed the questionnaires - the Russian version of GAD-7 and Hospital Anxiety and Depression Scale (HADS) to assess convergent validity. Chi-square and Fisher's exact tests were used to compare categorical variables, and the Mann-Whitney test was used for the quantitative ones. Internal consistency was assessed using Cronbach's alpha, Cronbach's alpha at point deletion, and corrected point-to-point correlation. ROC analysis was used to evaluate the properties of the GAD-7 to determine anxiety disorders.

Results: Among 97 (41.6%) patients with epilepsy diagnosed with any anxiety disorders, 42 (18%) had panic disorder, 37 (15.9%) had agoraphobia, 17 (7.3%) had social anxiety disorder, and 64 (27.5%) had generalized anxiety disorder; 42 patients (18%) showed a combination of several anxiety disorders. The overall GAD-7 score was similar to other epilepsy studies, but higher cutoff scores characterize our sample. The scale performed well in detecting any anxiety disorder with the AUC of 0.866 and the optimal cutoff point > 8 points, and in detecting GAD with AUC = 0.922 and the optimal cutoff point > 9 points, showing overall acceptable sensitivity.

Conclusion: Russian version of the GAD-7 could be used as a screening tool for any anxiety disorders in PWE with the optimal cutoff score > 8 points.
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http://dx.doi.org/10.1016/j.yebeh.2021.108269DOI Listing
October 2021

Interictal dysphoric disorder in people with and without epilepsy.

Epilepsia 2021 06 15;62(6):1382-1390. Epub 2021 Apr 15.

Research and Clinical Center for Neuropsychiatry, Moscow, Russian Federation.

Objective: Interictal dysphoric disorder (IDD) has been regarded as an affective disorder occurring only in people with epilepsy (PWE). Data showing similar characteristics and similar prevalence of IDD in patients with migraine and with psychogenic nonepileptic seizures question the epilepsy-specific nature of IDD. The aim of the study was to investigate the nature of IDD in people with prevalent epilepsy with mood disorders and people with mood disorders who are free of neurological disease.

Methods: This is a case-control study, with 142 patients with a confirmed diagnosis of epilepsy and major depressive disorder (MDD; cases) and 222 patients with MDD only (controls). MDD diagnosis was confirmed by a structured clinical interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition (SCID-I-RV). We used the Beck Depression Inventory and the Beck Anxiety Inventory to estimate anxiety and depression levels and the Interictal Dysphoric Disorder Inventory (IDDI) to confirm the presence of IDD. Mann-Whitney U test, Pearson chi-squared, Spearman correlation, and logistic regression were used.

Results: No differences were found in the prevalence of IDD between PWE with MDD and people with MDD alone (88.73% vs. 85.13%, χ2 = .96, p = .32). There were no differences between the groups overall or for any IDDI subscales (all p > .05). In both groups, IDD symptoms were grouped with the same incidence and had the same duration and periodicity. IDD was not associated with epilepsy (odds ratio = .84, 95% confidence interval = .40-1.98, p = .72). No significant correlation was found between epilepsy, demographic characteristics, and all IDDI subscales (all p > .05). Notably, patients with IDD suffered from affective disorders longer (6.68 ± 6.82 years vs. 3.7 ± 3.97 years, p = .001) and also received higher scores on all psychometric scales (all p < .05).

Significance: This study does not confirm the specificity of IDD for epilepsy. The presence of IDD symptoms may be associated with a more severe course of MDD and significant anxiety distress.
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http://dx.doi.org/10.1111/epi.16902DOI Listing
June 2021

Geographical and Tick-Dependent Distribution of Flavi-Like Alongshan and Yanggou Tick Viruses in Russia.

Viruses 2021 03 11;13(3). Epub 2021 Mar 11.

Kazan Scientific Research Institute of Epidemiology and Microbiology of Rospotrebnadzor, 420015 Kazan, Russia.

The genus includes related, unclassified segmented flavi-like viruses, two segments of which have homology with flavivirus RNA-dependent RNA polymerase NS5 and RNA helicase-protease NS3. This group includes such viruses as Jingmen tick virus, Alongshan virus, Yanggou tick virus and others. We detected the Yanggou tick virus in and ticks in two neighbouring regions of Russia. The virus prevalence ranged from 0.5% to 8.0%. We detected RNA of the Alongshan virus in 44 individuals or pools of various tick species in eight regions of Russia. The virus prevalence ranged from 0.6% to 7.8%. We demonstrated the successful replication of the Yanggou tick virus and Alongshan virus in IRE/CTVM19 and HAE/CTVM8 tick cell lines without a cytopathic effect. According to the phylogenetic analysis, we divided the Alongshan virus into two groups: an group and an group. In addition, the group can be divided into European and Asian subgroups. We found amino acid signatures specific to the and groups and also distinguished between the European and Asian subgroups of the group.
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http://dx.doi.org/10.3390/v13030458DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998622PMC
March 2021

Validation of the Russian version of neurological disorders depression inventory for epilepsy (NDDI-E).

Epilepsy Behav 2020 12 24;113:107549. Epub 2020 Nov 24.

Research and Clinical Center for Neuropsychiatry, Moscow, Russian Federation; Pirogov Russian National Research Medical University, Moscow, Russian Federation.

Objective: To translate and validate the English version of the Neurologic Depression Disorders Inventory in Epilepsy (NDDI-E) into the Russian language as an instrument for rapid detection of major depressive episodes (MDE) for patients with epilepsy (PWE) from Russian Federation.

Methods: One hundred and 75 consecutive PWE were included in the study. All patients were assessed with Mini-International Neuropsychiatric Interview (MINI 6.0.0), Hospital Anxiety and Depression Scale (HADS) and the Russian version of NDDI-E. Chi-square, Fisher's exact and Mann-Whitney tests were used to compare PWE with and without MDE. We analyzed internal structural validity, external validity, and receiver operator characteristics.

Results: None of the participants had any difficulties in understanding the questions of NDDI-E. The internal consistency of the inventory was satisfactory (Cronbach's ά = 0.856). Correlation between the NDDI-E and the HADS scores was moderate (r = 0.64, P < 0.001), indicating acceptable external validity. NDDI showed good capacity to detect MDE, with area under the curve of 0.919 (95% CI = 0.868-0.955; standard error: 0.019; P < 0.001). An optimal cut-off point with the highest Yuden's index (J = 0.699) was  > 12. At this point NDDI-E showed sensitivity of 88.16% (95% CI = 78.7%-94.4%), specificity of 81.82% (95% CI = 72.8%-88.9%), positive predictive value of 59.3% (95% CI = 48.8%-69.0%), negative predictive value of 95.8% (95% CI = 92.5%-97.7%).

Conclusion: Russian version of NDDI-E is an affordable and fast screening tool with a good combination of sensitivity and specificity.
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http://dx.doi.org/10.1016/j.yebeh.2020.107549DOI Listing
December 2020

"Flora of Russia" on iNaturalist: a dataset.

Biodivers Data J 2020 17;8:e59249. Epub 2020 Nov 17.

Independent Researcher, Tyumen, Russia Independent Researcher Tyumen Russia.

Background: The "Flora of Russia" project on iNaturalist brought together professional scientists and amateur naturalists from all over the country. Over 10,000 people were involved in the data collection.

New Information: Within 20 months, the participants accumulated 750,143 photo observations of 6,857 species of the Russian flora. This constitutes the largest dataset of open spatial data on the country's biodiversity and a leading source of data on the current state of the national flora. About 87% of all project data, i.e. 652,285 observations, are available under free licences (CC0, CC-BY, CC-BY-NC) and can be freely used in scientific, educational and environmental activities.
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http://dx.doi.org/10.3897/BDJ.8.e59249DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7686226PMC
November 2020

"Flora of Russia" on iNaturalist: a dataset.

Biodivers Data J 2020 17;8:e59249. Epub 2020 Nov 17.

Independent Researcher, Tyumen, Russia Independent Researcher Tyumen Russia.

Background: The "Flora of Russia" project on iNaturalist brought together professional scientists and amateur naturalists from all over the country. Over 10,000 people were involved in the data collection.

New Information: Within 20 months, the participants accumulated 750,143 photo observations of 6,857 species of the Russian flora. This constitutes the largest dataset of open spatial data on the country's biodiversity and a leading source of data on the current state of the national flora. About 87% of all project data, i.e. 652,285 observations, are available under free licences (CC0, CC-BY, CC-BY-NC) and can be freely used in scientific, educational and environmental activities.
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http://dx.doi.org/10.3897/BDJ.8.e59249DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7686226PMC
November 2020

Increasing Fatigue Life of 09Mn2Si Steel by Helical Rolling: Theoretical-Experimental Study on Governing Role of Grain Boundaries.

Materials (Basel) 2020 Oct 13;13(20). Epub 2020 Oct 13.

Department of Mechanical and Industrial Engineering Faculty of Engineering, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway.

The structure and mechanical properties of the 09Mn2Si high-strength low-alloyed steel after the five-stage helical rolling (HR) were studied. It was revealed that the fine-grained structure had been formed in the surface layer ≈ 1 mm deep as a result of severe plastic strains. In the lower layers, the "lamellar" structure had been formed, which consisted of thin elongated ferrite grains oriented in the HR direction. It was shown that the five-stage HR resulted in the increase in the steel fatigue life by more than 3.5 times under cyclic tension. The highest values of the number of cycles before failure were obtained for the samples cut from the bar core. It was demonstrated that the degree of the elastic energy dissipation in the steel samples under loading directly depended on the area of the grain boundaries as well as on the grain shapes. The fine-grained structure possessed the maximum value of the average torsional energy among all the studied samples, which caused the local material structure transformation and the decrease in the elastic energy level. This improved the crack resistance under the cyclic mechanical loading. The effect of the accumulation of the rotational strain modes at the grain boundaries was discovered, which caused the local structure transformation at the boundary zones. In the fine-grained structure, the formation of grain conglomerates was observed, which increased the values of the specific modulus of the moment of force. This could be mutually compensated due to the small sizes of grains. At the same time, the coarse-grained structures were characterized by the presence of the small number of grains with a high level of the moments of forces at their boundaries. They could result in trans-crystalline cracking.
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http://dx.doi.org/10.3390/ma13204531DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7601125PMC
October 2020

Fluorescence Lifetime and Intensity of Thioflavin T as Reporters of Different Fibrillation Stages: Insights Obtained from Fluorescence Up-Conversion and Particle Size Distribution Measurements.

Int J Mol Sci 2020 Aug 26;21(17). Epub 2020 Aug 26.

Faculty of Physics, M.V. Lomonosov Moscow State University, Leninskie Gory 1/2, 119991 Moscow, Russia.

Thioflavin T (ThT) assay is extensively used for studying fibrillation kinetics in vitro. However, the differences in the time course of ThT fluorescence intensity and lifetime and other physical parameters of the system, such as particle size distribution, raise questions about the correct interpretation of the aggregation kinetics. In this work, we focused on the investigation of the mechanisms, which underlay the difference in sensitivity of ThT fluorescence intensity and lifetime to the formation of protein aggregates during fibrillation by the example of insulin and during binding to globular proteins. The assessment of aggregate sizes and heterogeneity was performed using dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). Using the sub-nanosecond resolution measurements, it was shown that the ThT lifetime is sensitive to the appearance of as much as a few percent of ThT bound to the high-affinity sites that occur simultaneously with an abrupt increase of the average particle size, particles concentration, and size heterogeneity. The discrepancy between ThT fluorescence intensity and a lifetime can be explained as the consequence of a ThT molecule fraction with ultrafast decay and weak fluorescence. These ThT molecules can only be detected using time-resolved fluorescence measurements in the sub-picosecond time domain. The presence of a bound ThT subpopulation with similar photophysical properties was also demonstrated for globular proteins that were attributed to non-specifically bound ThT molecules with a non-rigid microenvironment.
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http://dx.doi.org/10.3390/ijms21176169DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7504639PMC
August 2020

Isolation and Characterisation of Alongshan Virus in Russia.

Viruses 2020 03 26;12(4). Epub 2020 Mar 26.

Laboratory of Biology of Arboviruses, Chumakov Institute of Poliomyelitis and Viral Encephalitides, FSBSI Chumakov FSC R&D IBP RAS, 108819 Moscow, Russia.

In recent decades, many new flavi-like viruses have been discovered predominantly in different invertebrates and, as was recently shown, some of them may cause disease in humans. The Jingmenvirus (JMV) group holds a special place among flaviviruses and flavi-like viruses because they have a segmented ssRNA(+) genome. We detected Alongshan virus (ALSV), which is a representative of the JMV group, in ten pools of adult ticks collected in two geographically-separated Russian regions. Three of the ten strains were isolated in the tick cell line IRE/CTVM19. One of the strains persisted in the IRE/CTVM19 cells without cytopathic effect for three years. Most ALSV virions purified from tick cells were spherical with a diameter of approximately 40.5 nm. In addition, we found smaller particles of approximately 13.1 nm in diameter. We obtained full genome sequences of all four segments of two of the isolated ALSV strains, and partial sequences of one segment from the third strain. Phylogenetic analysis on genome segment 2 of the JMV group clustered our novel strains with other ALSV strains. We found evidence for the existence of a novel upstream open reading frame in the glycoprotein-coding segment of ALSV and other members of the JMV group.
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http://dx.doi.org/10.3390/v12040362DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7232203PMC
March 2020

Ixodid ticks and tick-borne encephalitis virus prevalence in the South Asian part of Russia (Republic of Tuva).

Ticks Tick Borne Dis 2019 08 26;10(5):959-969. Epub 2019 Apr 26.

Chumakov Institute of Poliomyelitis and Viral Encephalitides (FSBSI "Chumakov FSC R&D IBP RAS), prem. 8, k.17, pos. Institut Poliomyelita, poselenie Moskovskiy, Moscow 108819, Russia; I.M. Sechenov First Moscow State Medical University of the Ministry of Health of the Russian Federation (Sechenov University), Trubetskaya st., 8-2, Moscow 119991, Russia. Electronic address:

The most significant processes of arbovirus evolution can be expected to occur in the territories where ticks of different species cohabitate and at the boundaries of virus occurrence, where the probability of the appearance of new virus variants is high due to the possible shift in the main vectors and/or vertebrate hosts. One of the most interesting regions in this regard is the Republic of Tuva. Since most of its territory is covered by mountain ranges and intermountain basins, we were able to study the distribution of vectors and viruses in geographically isolated areas at different altitudes and in various landscapes. From 2008 to 2017, we conducted six expeditions to Tuva and collected 3,077 adult ticks and 24 nymphs. The distribution of tick species was confined to specific landscapes, as follows: Dermacentor nuttalli occurred in steppes, D. silvarum inhabited forest-steppe areas, and Ixodes persulcatus inhabited mixed forests. All three species of ticks were collected on plains and mountain slopes. The range of D. silvarum was shown to be lower than 1300 m above sea level (a.s.l.). Only D. nuttalli and I. persulcatus were collected at higher altitudes. According to our observations, single nymphs of D. nuttalli appear on animals one month before larvae appear. This finding confirms the hypothesis that the immature forms of D. nuttalli are able to overwinter under favourable conditions. We isolated 9 strains and 3 isolates of tick-borne encephalitis virus (TBEV) from I. persulcatus, one strain from D. nuttalli and one strain from D. silvarum. The TBEV strain from D. nuttalli was isolated from the territory inhabited only by Dermacentor ticks. All isolated strains belong to the Siberian subtype of TBEV. TBEV was detected in ticks from all the investigated altitudes. There were no statistically significant differences in the virus prevalence between the Dermacentor and Ixodes ticks. The results of our work provide additional support for the hypothesis of the existence of TBEV foci in areas with an absolute dominance of D. nuttalli.
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http://dx.doi.org/10.1016/j.ttbdis.2019.04.019DOI Listing
August 2019

Attitudes towards people with epilepsy in Moscow.

Epilepsy Behav 2017 05 18;70(Pt A):182-186. Epub 2017 Apr 18.

The S. Fyodorov Eye Microsurgery Federal State Institution, 59A, Beskudnikovsky Blvd., Moscow 127486, Russian Federation. Electronic address:

Purpose: To assess the knowledge and attitudes in Moscow towards people with epilepsy (PWE).

Methods: Data were collected from 1167 adults, permanent residents of Moscow, who were interviewed. A 10-item questionnaire was used addressing three major domains: familiarity with epilepsy (2 questions), understanding of epilepsy (5 questions), and attitude towards the PWE (3 questions). Results were standardized to the Moscow population.

Results: The study population was generally well informed about epilepsy. About 80% "has heard" of epilepsy; however, personal acquaintance with PWE was reported by less than half of the study participants. The level of understanding of the disease and its etiology was quite low. About 60% of the survey participants believed that epilepsy was a type of mental retardation. One-third (34%) of respondents were afraid to stay in the proximity of PWE. Only 38% of the survey participants considered epilepsy to be curable; men significantly less frequently than women. Overall, the level of understanding of epilepsy was proportional to the level of education of respondents. Negative attitudes towards PWE were demonstrated in a significant part of the population. Almost half of the respondents would object to their child playing or studying with a child who has epilepsy and more than half (57%) were against the marriage of their daughter or son to a person with epilepsy. Two-fifths of the respondents ranked epilepsy as the "least preferred" of the six chronic diseases for a colleague.

Conclusion: This is the first study on awareness and attitudes to PWE in the adult population of Moscow. The study demonstrated that the general public is familiar with epilepsy, but has a rather low level of understanding of essential aspects of the disease. There is an overall high level of negative attitudes towards PWE in Russia, creating a need for targeted interventions. These results reinforced the importance of public education in reducing the stigma of epilepsy.
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http://dx.doi.org/10.1016/j.yebeh.2017.03.020DOI Listing
May 2017

Hair cortisol as a marker of hypothalamic-pituitary-adrenal Axis activity in female patients with major depressive disorder.

Metab Brain Dis 2017 04 7;32(2):577-583. Epub 2017 Jan 7.

Healthcare Department of Moscow, Moscow Research and Clinical Center for Neuropsychiatry, Moscow, Russia.

Hair cortisol is regarded as a promising marker of hypothalamic-pituitary-adrenal axis (HPAA) activity alterations due to stress, somatic and mental health conditions. Hair cortisol was previously reported to be elevated in patients with depression, however the data related to remission and recurrent depressive episodes are different. In this study, levels of hair cortisol were assessed in female patients with major depressive disorder (MDD) and the validity of hair cortisol as a marker of HPAA activity in this condition was evaluated. Hair cortisol was measured in 1 cm hair segments of 21 female patients with MDD and 22 female age-matched controls using enzyme-immunoassay analysis. Concurrently, serum cortisol was assessed and psychological status was evaluated using 17-item Hamilton Depression Rating Scale (HAMD-17), Beck Depression Inventory (BDI) and the Spielberger state trait anxiety inventory (STAI). The levels of hair cortisol were significantly lower in the MDD group, while serum cortisol levels were significantly higher in patients, as compared with controls. A significant negative correlation was found between HAMD-17 scores and hair cortisol. Decreased hair cortisol found in female patients with MDD as compared to controls suggests downregulation of HPAA activity during the preceding month. Further studies are needed to investigate the profiles of hair cortisol at different stages of depressive disorder to establish this parameter as a handy clinical tool.
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http://dx.doi.org/10.1007/s11011-017-9952-0DOI Listing
April 2017

Wideband analytical equivalent circuit for one-dimensional periodic stacked arrays.

Phys Rev E 2016 Jan 15;93(1):013306. Epub 2016 Jan 15.

Department of Electrical Engineering, Center for Applied Electromagnetic Systems Research (CAESR), University of Mississippi, University, Mississippi 38677, USA.

A wideband equivalent circuit is proposed for the accurate analysis of scattering from a set of stacked slit gratings illuminated by a plane wave with transverse magnetic or electric polarization that impinges normally or obliquely along one of the principal planes of the structure. The slit gratings are printed on dielectric slabs of arbitrary thickness, including the case of closely spaced gratings that interact by higher-order modes. A Π-circuit topology is obtained for a pair of coupled arrays, with fully analytical expressions for all the circuit elements. This equivalent Π circuit is employed as the basis to derive the equivalent circuit of finite stacks with any given number of gratings. Analytical expressions for the Brillouin diagram and the Bloch impedance are also obtained for infinite periodic stacks.
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http://dx.doi.org/10.1103/PhysRevE.93.013306DOI Listing
January 2016

Increased S-nitrosothiols are associated with spinal cord injury in multiple sclerosis.

J Clin Neurosci 2016 Jun 6;28:38-42. Epub 2016 Jan 6.

Institute of Higher Nervous Activity & Neurophysiology RAS, Department of Functional Biochemistry of the Nervous System, Butlerov Street 5A, Moscow 117485, Russia.

Multiple sclerosis (MS) is an immune-mediated disorder associated with inflammation, demyelination and axonal damage. In search of potential biomarkers of spinal cord lesions in MS related to nitric oxide metabolites, we measured total nitrite and nitrate levels, and protein-bound nitrotyrosine and S-nitrosothiol concentrations in the serum of MS patients at different stages of the disease. Sixty-eight patients and 36 healthy volunteers were included in the study. Total nitrite and nitrate levels were augmented in relapsing-remitting MS, while increased S-nitrosothiol concentrations were found both in relapsing-remitting and secondary-progressive MS. Further analysis demonstrated that S-nitrosothiol levels were selectively increased in patients with spinal cord injury. The data suggest that high S-nitrosothiol concentration may be a potential serum biomarker for spinal cord injury in MS.
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http://dx.doi.org/10.1016/j.jocn.2015.09.017DOI Listing
June 2016

Expression of BDNF and TrkB Phosphorylation in the Rat Frontal Cortex During Morphine Withdrawal are NO Dependent.

Cell Mol Neurobiol 2016 Aug 7;36(6):839-849. Epub 2015 Sep 7.

Institute of Higher Nervous Activity and Neurophysiology, Russian Academy of Sciences, 5a Butlerov Str., Moscow, Russia, 117485.

Nitric oxide (NO) mediates pharmacological effects of opiates including dependence and abstinence. Modulation of NO synthesis during the induction phase of morphine dependence affects manifestations of morphine withdrawal syndrome, though little is known about mechanisms underlying this phenomenon. Neurotrophic and growth factors are involved in neuronal adaptation during opiate dependence. NO-dependent modulation of morphine dependence may be mediated by changes in expression and activity of neurotrophic and/or growth factors in the brain. Here, we studied the effects of NO synthesis inhibition during the induction phase of morphine dependence on the expression of brain-derived neurotrophic factor (BDNF), glial-derived neurotrophic factor (GDNF), nerve growth factor (NGF), and insulin-like growth factor 1 (IGF1) as well as their receptors in rat brain regions after spontaneous morphine withdrawal in dependent animals. Morphine dependence in rats was induced within 6 days by 12 injections of morphine in increasing doses (10-100 mg/kg), and NO synthase inhibitor L-N(G)-nitroarginine methyl ester (L-NAME) (10 mg/kg) was given 1 h before each morphine injection. The expression of the BDNF, GDNF, NGF, IGF1, and their receptors in the frontal cortex, striatum, hippocampus, and midbrain was assessed 40 h after morphine withdrawal. L-NAME treatment during morphine intoxication resulted in an aggravation of the spontaneous morphine withdrawal severity. Morphine withdrawal was accompanied by upregulation of BDNF, IGF1, and their receptors TrkB and IGF1R, respectively, on the mRNA level in the frontal cortex, and only BDNF in hippocampus and midbrain. L-NAME administration during morphine intoxication decreased abstinence-induced upregulation of these mRNAs in the frontal cortex, hippocampus and midbrain. L-NAME prevented from abstinence-induced elevation of mature but not pro-form of BDNF polypeptide in the frontal cortex. While morphine abstinence did not affect TrkB protein levels as well as its phosphorylation status, inhibition of NO synthesis decreased levels of phosphorylated TrkB after withdrawal. Thus, NO signaling during induction of dependence may be involved in the mechanisms of BDNF expression and processing at abstinence, thereby affecting signaling through TrkB in the frontal cortex.
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http://dx.doi.org/10.1007/s10571-015-0267-6DOI Listing
August 2016

Cloaking of single and multiple elliptical cylinders and strips with confocal elliptical nanostructured graphene metasurface.

J Phys Condens Matter 2015 May 20;27(18):185304. Epub 2015 Apr 20.

In this paper, we present a novel analytical approach for cloaking of dielectric and metallic elliptical cylinders with a graphene monolayer and a nanostructured graphene metasurface at low-terahertz frequencies. The analytical approach is based on the solution of the electromagnetic scattering problem in terms of elliptical waves represented by the radial and angular even and odd Mathieu functions, with the use of sheet impedance boundary conditions at the metasurface. It is shown that scattering cancellation occurs for all incident and observation angles. A special case concerns cloaking of a 2D metallic strip represented by a degenerated ellipse, wherein the focal points of the cloak metasurface correspond to the edges of the strip. The analytical approach has been extended in order to cloak a cluster of elliptical objects for different cases of closely spaced, merging, and overlapping configurations. The results obtained by our analytical approach are validated with full-wave numerical simulations.
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http://dx.doi.org/10.1088/0953-8984/27/18/185304DOI Listing
May 2015

Spinal cord stimulation and sacral nerve stimulation for postlaminectomy syndrome with significant low back pain.

Neuromodulation 2014 Dec 14;17(8):763-5. Epub 2014 Mar 14.

Comprehensive Pain Management of the Fox Valley, Neenah, WI, USA.

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http://dx.doi.org/10.1111/ner.12144DOI Listing
December 2014

Resolution of Lhermitte's sign with spinal cord stimulation.

Pain Med 2014 Jan 14;15(1):167-9. Epub 2013 Aug 14.

Comprehensive Pain Management of the Fox Valley, SC, Appleton, Wisconsin, USA.

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http://dx.doi.org/10.1111/pme.12215DOI Listing
January 2014

Treatment of multifocal pain with spinal cord stimulation.

Neuromodulation 2012 May-Jun;15(3):210-3; discussion 213. Epub 2012 Feb 29.

Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI 54911, USA. aeyakovlev

Introduction: We report a retrospective case study of combined treatment of cancer-related pain and chronic low back and lower extremity pain related to postlaminectomy syndrome (PLS) with one spinal cord stimulation (SCS) system.

Methods: The patient underwent an uneventful SCS trial with percutaneous placement of two temporary eight-electrode leads (Medtronic Inc., Minneapolis, MN) placed at the level of T8-T9-T10 and T5-T6-T7.

Results: After successful trial, he was implanted with permanent leads and generator, reporting sustained pain relief at 12-month follow-up visit.

Discussion: SCS is a trialable, reversible, and interactive therapy permitting patients to control the level of stimulation they feel based on their degree of pain.

Conclusion: SCS provides an effective, alternative treatment for select patients with cancer-related chest wall pain and pain related to PLS who have failed conservative treatment.
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http://dx.doi.org/10.1111/j.1525-1403.2012.00435.xDOI Listing
November 2012

Spinal cord stimulation as alternative treatment for chronic post-herniorrhaphy pain.

Neuromodulation 2010 Oct;13(4):288-90; discussion 291

Comprehensive Pain Management of the Fox Valley, Appleton, WI, USA.

Objective: Our goal was to determine the efficacy of spinal cord stimulation for patients with intractable post-herniorrhaphy pain which conventional treatment failed to ameliorate.

Procedure: The patients underwent an uneventful spinal cord stimulator (SCS) trial with percutaneous placement of two eight-electrode epidural leads (Medtronic Inc, Minneapolis, MN, USA) to level T7-T8-T9.

Results: Upon experiencing excellent pain relief over the next two days during the trial, the patients were implanted with permanent leads and rechargeable or non-rechargeable generators two to four weeks later and reported sustained pain relief during following 12 months after implantation.

Conclusion: We conclude that SCS offers an alternative treatment option for intractable post-herniorrhaphy pain. This type of treatment should be considered for use in a select group of patients when all conventional treatments failed.
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http://dx.doi.org/10.1111/j.1525-1403.2010.00276.xDOI Listing
October 2010

Treatment of chronic intractable hip pain after iliac crest bone graft harvest using peripheral nerve field stimulation.

Neuromodulation 2011 Mar-Apr;14(2):156-9; discussion 159. Epub 2011 Jan 6.

Comprehensive Pain Management of the Fox Valley, Appleton, WI 54911, USA.

Introduction: Autologous iliac crest bone graft (ICBG) harvest is a common procedure performed at the time of many spinal surgical procedures and associated with morbidity incurred at the harvest site, the most troublesome being chronic donor site pain.

Methods: The patient underwent an uneventful peripheral nerve field stimulation (PNFS) trial with percutaneous placement of two temporary eight-electrode leads (Medtronic Inc., Minneapolis, MN, USA) placed in epifascial plane over the left ICBG harvest site.

Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and generator two weeks later and reported sustained pain relief at 12-month follow-up visit.

Discussion: Peripheral nerve field stimulation provides an effective treatment option for patients suffering from chronic hip pain after ICBG harvest who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and more invasive techniques.

Conclusion: Peripheral nerve field stimulation offers an alternative treatment option for select patients with chronic hip pain after ICBG harvest.
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http://dx.doi.org/10.1111/j.1525-1403.2010.00322.xDOI Listing
February 2012

Treatment of chronic chest wall pain in a patient with Loeys-Dietz syndrome using spinal cord stimulation.

Neuromodulation 2011 Jan 7;14(1):27-9; discussion 29. Epub 2010 Oct 7.

Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI 54911, USA.

Objective: Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable pain including chronic chest pain.

Methods: The patient with a history of Loeys-Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain underwent an uneventful SCS trial with percutaneous epidural placement of two temporary eight-electrode leads placed at the level of T3-T4-T5.

Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and rechargeable generator four weeks later and reported sustained pain relief at 12-month follow-up visit.

Conclusion: SCS provides an effective, alternative treatment option for select patients with Loeys-Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain who have failed conservative treatment. SCS may provide pain relief with advantages over conservative treatments and more invasive techniques.
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http://dx.doi.org/10.1111/j.1525-1403.2010.00298.xDOI Listing
January 2011

Peripheral nerve field stimulation in the treatment of postlaminectomy syndrome after multilevel spinal surgeries.

Neuromodulation 2011 Nov-Dec;14(6):534-8; discussion 538. Epub 2011 Aug 19.

Comprehensive Pain Management of the Fox Valley, Appleton, Wisconsin 54911, USA.

Introduction: Chronic low back pain in patients with postlaminectomy syndrome (PLS) is challenging to treat, especially for patients who have undergone multilevel surgical procedures. Despite conservative therapy and available interventional pain procedures including spinal cord stimulation (SCS) and intrathecal therapies, patients may continue with intractable low back pain. Peripheral nerve field stimulation (PNFS) may represent an effective alternative treatment option for these patients when conventional treatments do not provide adequate relief of intractable low back pain.

Methods: Eighteen patients underwent an uneventful PNFS trial with percutaneous placement of four temporary quadripolar leads (Medtronic, Inc., Minneapolis, MN, USA) placed subcutaneously over the lumbar or thoraco-lumbar area.

Results: After experiencing excellent pain relief over the next two days, temporary leads were removed. The patients were implanted with permanent leads and rechargeable or non-rechargeable generator two to four weeks after temporary lead removal. All patients reported sustained pain relief 12 months after implantation.

Discussion: PNFS with use of four vertically orientated leads provides an effective treatment option for patients with PLS after multilevel surgical procedures with intractable low back pain who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and interventional treatments including SCS and intrathecal therapy.

Conclusion: PNFS may be more effective in treating intractable low back pain than SCS in patients with PLS after multilevel spinal surgeries.
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http://dx.doi.org/10.1111/j.1525-1403.2011.00387.xDOI Listing
August 2012

Spinal cord stimulation for cancer-related low back pain.

Am J Hosp Palliat Care 2012 Mar 13;29(2):93-7. Epub 2011 Jun 13.

Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI, USA.

Objective: At least one third of patients with cancer have pain at the time of their diagnosis. In an attempt to provide increased pain relief for patients with intractable cancer pain, unconventional agents and interventional procedures including spinal cord stimulation (SCS) have received considerable attention.

Methods: Patients with cancer-related low back pain underwent an uneventful SCS trial with percutaneous placement of 2 temporary 8-electrode leads placed at the level of T8-T9-T10.

Results: After experiencing excellent pain relief during the 2-day trial, patients were subsequently implanted with permanent leads and generator with sustained pain relief at 12 months postoperation.

Conclusion: Spinal cord stimulation provides an effective, alternative treatment option for select patients with cancer-related pain who have failed conservative treatment.
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http://dx.doi.org/10.1177/1049909111410414DOI Listing
March 2012

Sacral nerve stimulation: a novel treatment of chronic anal fissure.

Dis Colon Rectum 2011 Mar;54(3):324-7

Comprehensive Pain Management of the Fox Valley, Appleton, WI, USA.

Objective: The purpose of this pilot study of 5 patients was to test the feasibility of a new treatment approach for chronic anal fissure utilizing minimally invasive sacral nerve stimulation before designing and conducting a larger prospective controlled study.

Measurements: The patients underwent uneventful placement of one temporary 8-electrode Octad lead for sacral nerve root stimulation. Stimulation was conducted for 20 minutes 3 times per day. The lead was removed after 3 weeks of stimulation.

Results: The patients experienced an immediate improvement in perineal pain after the initiation of sacral nerve stimulation. The pain relief effect lasted 10 to 12 hours, so stimulation was conducted for short episodes to ensure patient comfort and to extend the battery life of the external neurostimulator. For all patients, the chronic anal fissure healed by the end of the third week of temporary sacral nerve stimulation. There was no recurrence of anal fissure 1 year after treatment in all of the study participants.

Conclusion: Sacral nerve stimulation offers an effective alternative treatment option for chronic anal fissure in patients who chose not to pursue more invasive surgical interventions.
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http://dx.doi.org/10.1007/DCR.0b013e318202f922DOI Listing
March 2011

Successful treatment of chronic anal fissure utilizing sacral nerve stimulation.

WMJ 2010 Oct;109(5):279-82

Comprehensive Pain Management of the Fox Valley, SC, 820 E Grant St, Ste 335, Appleton, WI 54911, USA.

Objective: This is a report of a novel treatment approach for chronic anal fissure using minimally invasive sacral nerve stimulation (SNS).

Measurements: The patient underwent uneventful placement of 1 temporary 8-electrode lead (Medtronic Inc, Minneapolis, Minnesota) for sacral nerve root stimulation.

Results: The patient experienced instantaneous relief of perineal pain after start of SNS and steady healing of the fissure by the end of the second week.

Conclusion: SNS offers an alternative treatment option of chronic anal fissure for patients who choose not to use more invasive surgical interventions.
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October 2010

Treatment of intractable hip pain after THA and GTB using peripheral nerve field stimulation: a case series.

WMJ 2010 Jun;109(3):149-52

Comprehensive Pain Management of the Fox Valley, SC, Appleton, WI 54911, USA.

Objective: It has been estimated that 10%-35% of patients who undergo total hip arthroplasty (THA) have chronic postoperative pain, most often located at the greater trochanter. After greater trochanteric bursectomy (GTB), patients also may continue to experience chronic surgical site pain. Chronic pain has a neuropathic component, which often responds poorly to opioids. In an attempt to provide increased pain relief for patients with intractable chronic pain, unconventional agents and interventional management approaches have received considerable attention. Peripheral nerve field stimulation (PNFS) has been used with increased frequency as a minimally invasive and safe intervention for the management of intractable neuropathic postoperative pain. The objective of this retrospective study was to evaluate the efficacy of PNFS for treatment of chronic hip pain after THA and GTB.

Methods: Twelve patients with chronic post-operative pain after THA and GTB underwent an uneventful PNFS trial with percutaneous placement of 2 temporary 8-electrode leads (Medtronic Inc, Minneapolis, Minn) positioned in the subcutaneous tissue in the area of greatest pain, parallel to postoperative scar over the affected upper lateral thigh.

Results: After experiencing excellent pain relief over the next 2 days, the patients were implanted with permanent leads and rechargeable or non-rechargeable generator 2-4 weeks later. They reported sustained pain relief at 12-month follow-up visits.

Conclusion: PNFS provides an effective alternative treatment option for select patients with chronic postoperative pain after THA and GTB who have failed conservative treatment.
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June 2010

Circuit modeling of the transmissivity of stacked two-dimensional metallic meshes.

Opt Express 2010 Jun;18(13):13309-20

Dept. of Electrical Engineering, University of Mississippi, University, MS 38677-1848, USA.

This paper presents a simple analytical circuit-like model to study the transmission of electromagnetic waves through stacked two-dimensional (2-D) conducting meshes. When possible the application of this methodology is very convenient since it provides a straightforward rationale to understand the physical mechanisms behind measured and computed transmission spectra of complex geometries. Also, the disposal of closed-form expressions for the circuit parameters makes the computation effort required by this approach almost negligible. The model is tested by proper comparison with previously obtained numerical and experimental results. The experimental results are explained in terms of the behavior of a finite number of strongly coupled Fabry-Pérot resonators. The number of transmission peaks within a transmission band is equal to the number of resonators. The approximate resonance frequencies of the first and last transmission peaks are obtained from the analysis of an infinite structure of periodically stacked resonators, along with the analytical expressions for the lower and upper limits of the pass-band based on the circuit model.
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http://dx.doi.org/10.1364/OE.18.013309DOI Listing
June 2010

Treatment of cancer-related chest wall pain using spinal cord stimulation.

Am J Hosp Palliat Care 2010 Dec 16;27(8):552-6. Epub 2010 Jun 16.

Comprehensive Pain Management of the Fox Valley, Appleton, WI 54911, USA.

Objective: it has been estimated that 15% to 40% of chronic cancer pain has a neuropathic component, and this type of pain often responds poorly to opioids. In an attempt to provide increased pain relief for patients with intractable cancer pain, unconventional agents and interventional management approaches have received considerable attention. Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable cancer pain.

Methods: the patients with a history of cancer-related chest wall pain underwent an uneventful SCS trial with percutaneous placement of 2 temporary 8-electrode leads (Medtronic Inc, Minneapolis, Minnesota) placed at the level of T3-T4-T5.

Results: after experiencing excellent pain relief over the next 2 days, the patients were implanted with permanent leads and rechargeable generator 2 to 2 ½ weeks later and reported sustained pain relief at 12-month follow-up visit.

Conclusion: SCS provides an effective, alternative treatment option for select patients with cancer-related chest wall pain who have failed conservative treatment. SCS may provide pain relief with advantages over conservative treatments and more invasive techniques.
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http://dx.doi.org/10.1177/1049909110373240DOI Listing
December 2010
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