scholarly journals Genetic polymorphism of CYP1A1 and CYP2D6 in populations of Buryats, Teleuts and Russians of Eastern Siberia

2018 ◽  
Vol 22 (2) ◽  
pp. 205-211 ◽  
Author(s):  
L. E. Tabikhanova ◽  
L. P. Osipova ◽  
T. V. Churkina ◽  
E. N. Voronina ◽  
M. L. Filipenko
Keyword(s):  
High Frequency ◽  
Genetic Research ◽  
Indigenous Populations ◽  
Eastern Siberia ◽  
Frequency Range ◽  
East Siberia ◽  
Gene Frequencies ◽  
Allele Specific ◽  
Polymorphic Variants ◽  
Frequency Occurrence

The study of the gene polymorphism of the system of biotransformation of xenobiotics is an important area of modern medical and genetic research. The aim of this work is to study the frequency of the alleles of the CYP1A1 (A2455G (*2C), rs1048943), CYP2D6 (A2549del (*3), rs35742686); G1846A (*4), rs3892097) genes of Teleuts (n = 115), Eastern Buryats (n = 132), Western Buryats (n = 280), their Métis (n = 56), and Russians of East Siberia (n = 122). Genotyping was performed using real-time PCR with competitive TaqMan allele-specific probes. The frequency of the CYP1A1*2C (2455G) allele was 28.8 % in the Eastern Buryat, 34.6 % in the Western Buryat, 16.7 % in the Teleut, and 31.3 % in the Métis cohort. The frequency of CYP1A1*2C (2455G) in the Russians of Eastern Siberia (4.1 %) corresponds to the frequency range found in European populations. A high-frequency occurrence of CYP1A1*2C (2455G) among Buryats and Teleuts may be indicative of a higher population-wide risk of diseases influenced by technogenic pollutants – substrates of CYP1A1. The CYP2D6*3 (2549del) allele was not detected in cohorts of indigenous populations, among Russians it was 0.4 %, and it was 2.7 % among Métis. The frequency of CYP2D6*4 (1846A) in Eastern and Western Buryats was 5.3 % and 4.3 %, respectively, for Teleuts it was 7.4 %. It was significantly higher in the Russian population (12 %), and among Métis (9.8 %). The obtained data makes it possible to predict a reduced risk of side effects of drugs and cancer associated with CYP2D6*3 (2549del) and CYP2D6*4 (1846A) in the Buryat and Teleut populations. However, metisation introduces new polymorphic variants into indigenous populations, shifts gene frequencies and changes the degree of risks.

scholarly journals Distribution of polymorphic variants of genes for xenobiotic biotransformation GSTM1, GSTT1 and GSTP1 in populations of native inhabitants and Russians of Eastern Siberia

2020 ◽  
pp. 24-34
Author(s):  
Л.Э. Табиханова ◽  
Л.П. Осипова ◽  
Е.Н. Воронина ◽  
М.Л. Филипенко
Keyword(s):  
Real Time ◽  
Real Time Pcr ◽  
Genetic Research ◽  
Total Sample ◽  
Eastern Siberia ◽  
Multifactorial Diseases ◽  
Genotypic Combination ◽  
Risk Alleles ◽  
Polymorphic Variants ◽  
The Difference

Актуальность. Изучение полиморфизма генов системы биотрансформации ксенобиотиков, ассоциированных с рядом многофакторных заболеваний - важное направление современных медико-генетических исследований. Цель и задачи - выявить этнические особенности распределения полиморфных вариантов генов GSTM1, GSTT1 и GSTP1 среди бурят, телеутов и русских Восточной Сибири. Материалы и методы. Изучены выборки восточных (N=139) и западных (N=284) бурят, метисов западных бурят с русскими (N=47), телеутов (N=115) и русских Восточной Сибири (N=122). Выявление генотипов GSTM1 0/0 и GSTT1 0/0 проводилось методом мультиплексной полимеразной цепной реакции в режиме реального времени, генотипирование GSTP1 проводили в режиме реального времени с использованием TaqMan-зондов. Результаты. Встречаемость генотипа GSTM1 0/0 среди восточных и западных бурят составляет 37,7% и 57,7% соответственно (51,4% в суммарной выборке бурят), среди русских - 42,6%. Статистически значимо меньшая частота показана у телеутов - 17,4%. Частота GSTТ1 0/0 у восточных и западных бурят равна 40,8% и 27,6% соответственно, у русских статистически значимо меньше - 18%, у телеутов - 24,8%. Для метисов показаны промежуточные значения частот GSTM1 0/0 и GSTТ1 0/0. Аллель GSTP1 1405G встречается среди восточных и западных бурят с частотой 27,7% и 19,2% соответственно, у русских - 31,8%, телеутов - 24,8%. Различие русских с западными бурятами статистически значимо. Частота аллеля GSTP1 2285T среди восточных (4,9%), западных (1,8%) бурят и телеутов (2,2%) меньше, чем среди русских (8,3%). Отличие русских от западных бурят и телеутов, является статистически значимым. Выводы. В суммарной выборке бурят показаны повышенные частоты генотипов GSTM1 0/0 и GSTТ1 0/0, ассоциированых, по данным литературы, с некоторыми многофакторными заболеваниями по сравнению с телеутами и русскими. В обеих выборках бурят статистически значимо повышена частота комбинированного генотипа, приводящего к отсутствию активности ферментов. В то же время у телеутов частота индивидов с генотипической комбинацией GSTM1 +GSTТ1 +, ответственной за нормальную ферментативную активность, статистически значимо выше. Частоты аллелей 1405G и 2285T гена GSTP1 среди бурят и телеутов понижены по сравнению с русскими. Метисация способствует изменению частоты аллелей. Статистически значимые различия в частотах вариантов GSTM1, GSTТ1 и GSTP1 внутри бурятского этноса могут свидетельствовать о его генетической неоднородности. Relevance. The study of the gene polymorphism of the system biotransformation of xenobiotics, which are associated with a number of multifactorial diseases, is an important area of modern medical genetic research. The aim and tasks are to reveal ethnic features in the distribution of polymorphic variants of genes GSTM1, GSTT1 and GSTP1 among Buryats, Teleuts and Russians of Eastern Siberia. Materials and methods. The samples of Eastern (N=139) and Western (N=284) Buryats, métis Western Buryats with Russians (N=47), Teleuts (N=115) and Russians of East Siberia (N=122) are studied. Detection of GSTM1 0/0 and GSTT1 0/0 was carried out through multiplex real-time PCR. Genotyping of GSTP1 was performed using TaqMan real-time PCR. Results. The occurrence of GSTM1 0/0 among Eastern and Western Buryats is 37.7% and 57.7% respectively (51.4% for the total sample of Buryats), among Russians - 42.6%. Significantly lower frequency is shown in Teleuts-17.4%. The frequency of GSTT1 0/0 in Eastern and Western Buryats is 40.8% and 27.6% respectively. It is significantly lower in Russians - 18%, in Teleuts - 24.8%. Mestis shows intermediate frequencies of GSTM1 0/0 and GSTТ1 0/0. GSTP1 1405G is found among Eastern and Western Buryats with 27.7% and 19.2% frequency, respectively, in Russians - 31.8%, Teleuts - 24.8%. The difference of Russians with Western Buryats is statistically significant. The frequencies of GSTP1 2285T among Eastern (4.9%), Western (1.8%) Buryats and Teleuts (2.2%) are lower than frequency among Russians (8.3%). The difference between Russians and Western Buryats with Teleuts is statistically significant. Summary. There are increased frequencies of GSTM1 0/0 and GSTT1 0/0 in the total cohort of Buryats in comparison with Teleuts and Russians. According to the literature data, these genotypes are associated with multi-factorial diseases. In both samples of Buryats, there is a statistically significantly increased frequency of the combined genotype resulting in the absence of enzyme activity. At the same time, there is a statistically significantly increased frequency of individuals with a genotypic combination GSTM1 +GSTT1 + responsible for normal enzymatic activity in the sample of Teleuts. There are reduced frequencies of risk-alleles GSTP1 1405G and 2285T among Buryats and Teleuts in comparison with Russians. Metisation changes the frequency of risk alleles. Significant differences in the frequencies of GSTM1, GSTT1 and GSTP1 within the Buryat ethnic group may indicate its genetic heterogeneity.

Evaluation of Special Hearing Aids for Deaf Children

1971 ◽  
Vol 36 (4) ◽  
pp. 527-537 ◽  
Author(s):  
Norman P. Erber
Keyword(s):  
Hearing Aids ◽  
High Frequency ◽  
Hearing Aid ◽  
Low Frequency ◽  
Acoustic Stimulation ◽  
Deaf Children ◽  
Frequency Range ◽  
Frequency Limit ◽  
Unpublished Studies ◽  
Published Research

Two types of special hearing aid have been developed recently to improve the reception of speech by profoundly deaf children. In a different way, each special system provides greater low-frequency acoustic stimulation to deaf ears than does a conventional hearing aid. One of the devices extends the low-frequency limit of amplification; the other shifts high-frequency energy to a lower frequency range. In general, previous evaluations of these special hearing aids have obtained inconsistent or inconclusive results. This paper reviews most of the published research on the use of special hearing aids by deaf children, summarizes several unpublished studies, and suggests a set of guidelines for future evaluations of special and conventional amplification systems.

HIGH FREQUENCY OHMIC LOSSES IN TERAHERTZ FREQUENCY RANGE CW KLYNOTRONS

2017 ◽  
Vol 76 (10) ◽  
pp. 929-940 ◽  
Author(s):  
Yu. S. Kovshov ◽  
S. S. Ponomarenko ◽  
S. A. Kishko ◽  
A. A. Likhachev ◽  
S. A. Vlasenko ◽  
...  
Keyword(s):  
High Frequency ◽  
Terahertz Frequency ◽  
Frequency Range ◽  
Terahertz Frequency Range ◽  
Ohmic Losses

scholarly journals An Improved Time Integration Method Based on Galerkin Weak Form with Controllable Numerical Dissipation

2021 ◽  
Vol 11 (4) ◽  
pp. 1932
Author(s):  
Weixuan Wang ◽  
Qinyan Xing ◽  
Qinghao Yang
Keyword(s):  
High Frequency ◽  
Integration Method ◽  
Time Integration ◽  
Low Frequency ◽  
Weak Form ◽  
High Accuracy ◽  
Numerical Dissipation ◽  
Frequency Range ◽  
Time Integration Method ◽  
Numerical Damping

Based on the newly proposed generalized Galerkin weak form (GGW) method, a two-step time integration method with controllable numerical dissipation is presented. In the first sub-step, the GGW method is used, and in the second sub-step, a new parameter is introduced by using the idea of a trapezoidal integral. According to the numerical analysis, it can be concluded that this method is unconditionally stable and its numerical damping is controllable with the change in introduced parameters. Compared with the GGW method, this two-step scheme avoids the fast numerical dissipation in a low-frequency range. To highlight the performance of the proposed method, some numerical problems are presented and illustrated which show that this method possesses superior accuracy, stability and efficiency compared with conventional trapezoidal rule, the Wilson method, and the Bathe method. High accuracy in a low-frequency range and controllable numerical dissipation in a high-frequency range are both the merits of the method.

scholarly journals Band notched self complementaryultra wideband antenna for wireless applications

2018 ◽  
Vol 7 (2.8) ◽  
pp. 529 ◽  
Author(s):  
Ch Ramakrishna ◽  
G A.E.Satish Kumar ◽  
P Chandra Sekhar Reddy
Keyword(s):  
High Frequency ◽  
Return Loss ◽  
Wide Band ◽  
Ultra Wideband ◽  
Impedance Bandwidth ◽  
Relative Dielectric Permittivity ◽  
Frequency Range ◽  
Ground Structure ◽  
Wireless Applications ◽  
Patch Edge

This paper presents a band notched WLAN self complementaryultra wide band antenna for wireless applications. The proposed antenna encounters a return loss (RL) less than -10dB for entire ultra wideband frequency range except band notched frequency. This paper proposes a hexagon shape patch, edge feeding, self complementary technique and defective ground structure. The antenna has an overall dimensionof 28.3mm × 40mm × 2mm, builton  substrate FR4 with a relative dielectric permittivity 4.4. And framework is simulated finite element method with help of high frequency structured simulator HFSSv17.2.the proposed antenna achieves a impedance bandwidth of 8.6GHz,  band rejected WLAN frequency range 5.6-6.5 GHz with  vswr is less than 2.

scholarly journals A Compact Four-Port Coplanar Antenna Based on an Excitation Switching Reconfigurable Mechanism for Cognitive Radio Applications

2019 ◽  
Vol 9 (15) ◽  
pp. 3157 ◽  
Author(s):  
O ◽  
Jin ◽  
Choi
Keyword(s):  
Cognitive Radio ◽  
High Frequency ◽  
Coplanar Waveguide ◽  
Low Frequency ◽  
Loop Antenna ◽  
Ultra Wideband ◽  
Frequency Range ◽  
Uwb Antenna ◽  
High Isolation ◽  
Loop Antennas

In this paper, we propose a compact four-port coplanar antenna for cognitive radio applications. The proposed antenna consists of a coplanar waveguide (CPW)-fed ultra-wideband (UWB) antenna and three inner rectangular loop antennas. The dimensions of the proposed antenna are 42 mm × 50 mm × 0.8 mm. The UWB antenna is used for spectrum sensing and fully covers the UWB spectrum of 3.1–10.6 GHz. The three loop antennas cover the UWB frequency band partially for communication purposes. The first loop antenna for the low frequency range operates from 2.96 GHz to 5.38 GHz. The second loop antenna is in charge of the mid band from 5.31 GHz to 8.62 GHz. The third antenna operates from 8.48 GHz to 11.02 GHz, which is the high-frequency range. A high isolation level (greater than 17.3 dB) is realized among the UWB antenna and three loop antennas without applying any additional decoupling structures. The realized gains of the UWB antenna and three loop antennas are greater than 2.7 dBi and 1.38 dBi, respectively.

High Frequency Dielectric Response of the Ionic Liquid N-Methyl-N-ethylpyrrolidinium Dicyanamide

2007 ◽  
Vol 60 (1) ◽  
pp. 6 ◽  
Author(s):  
Simon Schrödle ◽  
Gary Annat ◽  
Douglas R. MacFarlane ◽  
Maria Forsyth ◽  
Richard Buchner ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Dielectric Loss ◽  
Dielectric Relaxation ◽  
High Frequency ◽  
Dielectric Response ◽  
Room Temperature ◽  
Room Temperature Ionic Liquid ◽  
Dielectric Relaxation Spectroscopy ◽  
Frequency Range ◽  
Fast Rotation

A study of the room-temperature ionic liquid N-methyl-N-ethylpyrrolidinium dicyanamide by dielectric relaxation spectroscopy over the frequency range 0.2 GHz ≤ ν ≤ 89 GHz has revealed that, in addition to the already known lower frequency processes, there is a broad featureless dielectric loss at higher frequencies. The latter is probably due to the translational (oscillatory) motions of the dipolar ions of the IL relative to each other, with additional contributions from their fast rotation.

Electromagnetic Property of La0.7Sr0.3MnO3/Ag Composite at High Frequency

2015 ◽  
Vol 655 ◽  
pp. 182-185
Author(s):  
Ke Lan Yan ◽  
Run Hua Fan ◽  
Min Chen ◽  
Kai Sun ◽  
Xu Ai Wang ◽  
...  
Keyword(s):  
High Frequency ◽  
Single Phase ◽  
Low Frequency ◽  
Electromagnetic Property ◽  
High Frequency Range ◽  
Frequency Range ◽  
Free Electron Concentration ◽  
Theoretical Simulation ◽  
Electrical And Magnetic Properties ◽  
Three Phase

The phase structure, and electrical and magnetic properties of La0.7Sr0.3MnO3(LSMO)-xAg (xis the mole ratio,x=0, 0.3, 0.5) composite were investigated. It is found that the sample withx=0 is single phase; the samples withx=0.3 and 0.5 present three phase composite structure of the manganese oxide and Ag. With the increasing of Ag content, the grain size of the samples increases and the grain boundaries transition from fully faceted to partially faceted. The permittivity of spectrum (10 MHz - 1 GHz) and the theoretical simulation reveal that the plasma frequencyfpincrease with Ag content, due to the increasing of free electron concentration, which is further supported by the enhancement of conductivity. While for the permeability (μr'), theμr'decrease with the increasing of Ag content at low frequency range (f< 20 MHz), while at the relative high frequency range (f> 300 MHz), theμr'increased with Ag content. Therefore, the introduction of elemental Ag resulted in a higherμr'at the relative high frequency range.

Ossicular Discontinuity and Exostoses in Proteus Syndrome: A Case Report

2005 ◽  
Vol 114 (3) ◽  
pp. 242-246
Author(s):  
Joni K. Doherty ◽  
Dennis R. Maceri
Keyword(s):  
Hearing Loss ◽  
High Frequency ◽  
Conductive Hearing Loss ◽  
Ossicular Chain ◽  
Typical Feature ◽  
Proteus Syndrome ◽  
Frequency Range ◽  
Pure Tone Average ◽  
Ossicular Chain Reconstruction ◽  
Conductive Hearing

Proteus syndrome (PS) is a rare hamartomatous disorder characterized by mosaic overgrowth of multiple tissues that manifests early in life and is progressive. The presence of unilateral external auditory canal exostoses in a patient who is not a swimmer or surfer is suggestive of PS. However, hearing loss is not a typical feature. Here, we describe exostoses and ossicular discontinuity with conductive hearing loss in a patient with PS. The treatment consisted of canalplasty and ossicular chain reconstruction. A postoperative reduction was demonstrated in the patient's air-bone gap, from 21 dB to 13 dB for the pure tone average (four frequencies) and from 41 dB to 15 dB in the high-frequency range (6,000 to 8,000 Hz). Causes of ossicular discontinuity are discussed. Routine annual audiometric and otolaryngological evaluation should be considered in all patients with temporal bone inyolvement of PS.

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