scholarly journals GEOMAGNETIC CHANGES AS A RISK FACTOR CAUSING OXIDATIVE STRESS IN HUMAN ERYTHROCYTES

2021 ◽  
pp. 136-143
Author(s):  
A.M. Irkaeva ◽  
◽  
E.S. Zhukova ◽  
T.G. Shcherbatyuk ◽  
V.V. Chernov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Catalase Activity ◽  
Geomagnetic Field ◽  
Superoxide Radical ◽  
Free Radical Oxidation ◽  
Antioxidant Protection ◽  
Radical Oxidation ◽  
Radical Production ◽  
Earth Magnetic Field ◽  
Living Organisms

At present impacts exerted by heliogeophysic factors on different living organisms are being examined more and more intensely. Over the last decade, it has been detected that meteorological factors play an important role in formation of adap- tation mechanisms in living systems. Sun and earth interaction is also known to directly influence rheological properties of human blood, both in a healthy body and in case there are chronic non-communicable diseases. Given that, impacts exerted by “cosmic weather” on living organisms, people in particular, are a stimulus to perform profound studies on reactions oc- curring as a response to effects produced by solar and geomagnetic activity, first of all, solar flares and magnetic storms. At present the most widely used approach to determining influences exerted by the Earth magnetic field on biologi- cal systems involves searching for correlations between different parameters of living organisms functioning and geo- magnetic indexes. Our research goal was to assess dependence between enzymatic activity of antioxidant protection system, exemplified by superoxide dismutase (SOD) and catalase, and geomagnetic field disturbances. The research focused on examining blood samples taken from conditionally healthy volunteers living in Nizhniy Nov- gorod region. SOD and catalase activity were determined in blood erythrocytes with spectrophotometry. Geomagnetic dis- turbances force was determined as per planetary Kp-index value. The research established a statistically significant correlation between SOD and catalase activity and a value of geo- magnetic field disturbance; this correlation allows making an indirect assumption that geomagnetic conditions directly in- fluence superoxide radical production in a body. Therefore, a change in superoxide radical production is a way for the geomagnetic field to influence living organisms. Activation of free radical oxidation can make for both occurrence and more intense clinical course of several diseases (espe- cially cardiovascular and neuropsychic ones). So, in future it is advisable to assess reactivity of antioxidant protection sys- tem as a response to geomagnetic fluctuations in case there are pathologic changes in a body.

scholarly journals GEOMAGNETIC CHANGES AS A RISK FACTOR CAUSING OXIDATIVE STRESS IN HUMAN ERYTHROCYTES

2021 ◽  
pp. 136-143
Author(s):  
A.M. Irkaeva ◽  
◽  
E.S. Zhukova ◽  
T.G. Shcherbatyuk ◽  
V.V. Chernov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Catalase Activity ◽  
Geomagnetic Field ◽  
Superoxide Radical ◽  
Free Radical Oxidation ◽  
Antioxidant Protection ◽  
Radical Oxidation ◽  
Radical Production ◽  
Earth Magnetic Field ◽  
Living Organisms

At present impacts exerted by heliogeophysic factors on different living organisms are being examined more and more intensely. Over the last decade, it has been detected that meteorological factors play an important role in formation of adap- tation mechanisms in living systems. Sun and earth interaction is also known to directly influence rheological properties of human blood, both in a healthy body and in case there are chronic non-communicable diseases. Given that, impacts exerted by “cosmic weather” on living organisms, people in particular, are a stimulus to perform profound studies on reactions oc- curring as a response to effects produced by solar and geomagnetic activity, first of all, solar flares and magnetic storms. At present the most widely used approach to determining influences exerted by the Earth magnetic field on biologi- cal systems involves searching for correlations between different parameters of living organisms functioning and geo- magnetic indexes. Our research goal was to assess dependence between enzymatic activity of antioxidant protection system, exemplified by superoxide dismutase (SOD) and catalase, and geomagnetic field disturbances. The research focused on examining blood samples taken from conditionally healthy volunteers living in Nizhniy Nov- gorod region. SOD and catalase activity were determined in blood erythrocytes with spectrophotometry. Geomagnetic dis- turbances force was determined as per planetary Kp-index value. The research established a statistically significant correlation between SOD and catalase activity and a value of geo- magnetic field disturbance; this correlation allows making an indirect assumption that geomagnetic conditions directly in- fluence superoxide radical production in a body. Therefore, a change in superoxide radical production is a way for the geomagnetic field to influence living organisms. Activation of free radical oxidation can make for both occurrence and more intense clinical course of several diseases (espe- cially cardiovascular and neuropsychic ones). So, in future it is advisable to assess reactivity of antioxidant protection sys- tem as a response to geomagnetic fluctuations in case there are pathologic changes in a body.

State of the enzyme link of antioxidant protection in boys with hypoandrogenism

2020 ◽  
Vol 40 (4) ◽  
pp. 32-36
Author(s):  
L. K. Parkhomenko ◽  
◽  
L. A. Strashok ◽  
S. I. Turchina ◽  
G. V. Kosovtsova ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Superoxide Dismutase ◽  
Free Radical ◽  
Glutathione Peroxidase ◽  
Free Radical Oxidation ◽  
Conjugated Dienes ◽  
Delayed Puberty ◽  
Control Group ◽  
Antioxidant Protection ◽  
Radical Oxidation

Recently, interest in the problem of free radical oxidation in biological membranes, which is directly related to both the normal functioning of cells and the occurrence, course and outcome of many pathological conditions, has increased again in clinical medicine. The aim was to determine the role and impact of antioxidant defense in boys with hypoandrogenism. The study involved 75 adolescents with hypoandrogenism aged 13–18 years, who underwent a complex of clinical and laboratory examinations. All patients were conducted complex of anthropometric research and determination of the degree of delayed puberty, laboratory and instrumental examination. Free radical oxidation was determined by the levels of malondialdehyde, conjugated dienes, carbonated proteins, superoxide dismutase and catalase in the serum, and restored glutathione and glutathione peroxidase in whole blood. Based on their determination, the coefficient of oxidative stress was calculated. Statistical processing of results was performed using parametric and nonparametric methods. The study of indicators of the free radical oxidation process found that adolescents with hypoandrogenism have multidirectional changes in the oxidation of proteins and lipids, namely: the level of conjugated dienes increases, the concentration of malondialdehyde remains at the level of the control group, and the level of carbonated proteins tends to decrease. As for the activity of antioxidant protection enzymes, a significant decrease in the level of glutathione peroxidase was detected, while the level of superoxide dismutase and catalase remained at the level of normative indicators. Oxidative stress accompanies and is one of the pathogenetic links in the formation or maintenance of the state of hypoandrogenism in boys. This requires the use of antioxidants, the complex of which must be selected individually.

Gender differences in biochemical measurement reflecting the state of free-radical oxidation and antioxidant protection among workers in metallurgical production

2019 ◽  
Vol 1 (10) ◽  
pp. 877-881
Author(s):  
I. A. Umnyagina ◽  
L. A. Strakhova ◽  
T. V. Blinova
Keyword(s):  
Oxidative Stress ◽  
Gender Differences ◽  
Free Radical ◽  
Biochemical Parameters ◽  
Free Radical Oxidation ◽  
The Body ◽  
Antioxidant Protection ◽  
Radical Oxidation ◽  
Metallurgical Production ◽  
Production Factors

Introduction. To date, age and sex differences have been established for many biochemical parameters. Gender differences in indicators for systems such as antioxidant, thiol-disulfide, oxidative stress and inflammation systems are absent or under study.The aim of the study was to identify gender differences in biochemical parameters reflecting the functioning of antioxidant systems of the body and free radical oxidation in workers of metallurgical production, in contact with harmful production factors.Materials and methods. The blood of men and women working at the metallurgical enterprise of the Nizhny Novgorod region (n=80) under the influence of a complex of physical and chemical production factors was studied. Total oxidative stress, total antioxidant capacity of serum, glutathione levels were studied by photometric biochemical methods. Levels of C-reactive protein and 8-hydroxy–2-deoxyguanosine were studied by ELISA.Results. The average amount of peroxides in the serum of women exceeded 1.6 times this figure in men. In the group of men, the content of 8-Ondg was higher by 26% (p=0.012), the level of GS-by 12% (p=0.019), the activity of SOD — by 1.5–2 times (p=0.0001), the level of CRP — by 2 times (p=0.008) compared to similar indicators in women.Conclusions. Studies of gender differences in workers under the influence of harmful production factors will allow more effective approach to the etiology, treatment and prognosis of production-related diseases. Indicators of oxidative stress and antioxidant protection can be indicators of the health of workers under the influence of harmful industrial factors and be important in the prevention of diseases associated with oxidative stress.

Assessment of the Biochemical Status of Workers Manufacturing Ethylbenzene and Styrene

2020 ◽  
pp. 40-43
Author(s):  
RR Galimova ◽  
ET Valeeva ◽  
GV Timasheva ◽  
AB Bakirov
Keyword(s):  
Catalase Activity ◽  
Free Radical Oxidation ◽  
The Body ◽  
Atherogenic Index ◽  
Radical Oxidation ◽  
Professional Groups ◽  
Biochemical Status ◽  
The Central Nervous System ◽  
Hepatic Protein Synthesis ◽  
Increased Activity

Introduction: Production of ethylbenzene and styrene (EBS) is one of the most important stages in organic synthesis. The products have general toxic, hepatotoxic, irritating and narcotic effects on the human body. Severe exposures to EВS can induce pronounced disorders of the central nervous system such as styrene sickness and encephalopathy and of peripheral blood such as leukopenia and lymphocytosis. Materials and methods: We studied homeostasis indices in 376 workers of the main professional groups engaged in the production of EBS including equipment operators, repairmen, and instrumentation and automation fitters. Results: We established an increase in lipid peroxidation by the level of malondialdehyde amid an increase in catalase activity and a decrease in blood retinol and α-tocopherol levels. We also noted an increased activity of indicator enzymes including ALT, AST, GGT, and alkaline phosphatase. Significant changes in lipid metabolism in the form of cholesterolemia, triglyceridemia, a higher atherogenic index, and lower cholesterol of non-atherogenic blood serum lipids demonstrating atherogenic changes in the body were revealed. Conclusions: The earliest prenosological disorders in the body of the examined workers included an impaired hepatic protein synthesis, the development of cytolysis processes and a change in the integrity and functional activity of the liver cell in individuals, an imbalance in the oxidant-antioxidant system, one of the reasons of which was the adverse occupational exposure to hazardous chemicals. An increase in catalase activity is a protective compensatory reaction during the activation of free radical oxidation processes.

scholarly journals INFLUENCE OF LASER TREATMENT ON INDICATORS OF FREE-RADICAL OXIDATION AND ANTIOXIDANT PROTECTION IN SECONDARY PYELONEPHRITIS

2019 ◽  
Vol 19 (1-2) ◽  
pp. 149-156
Author(s):  
I. I Antipkin ◽  
E. V Ryazantsev ◽  
V. E Ryazantsev ◽  
A. M Khoshnaw
Keyword(s):  
Catalase Activity ◽  
Clinical Medicine ◽  
Malonic Dialdehyde ◽  
Free Radical Oxidation ◽  
The Body ◽  
Complex Treatment ◽  
Metabolic Homeostasis ◽  
Radical Oxidation ◽  
Non Destructive ◽  
Single Kidney

Relevance. Optimization of the conservative tactics of acute inflammation of the kidney in nephrolithiasis makes it advisable to use non-traditional methods of detoxification low-intensity laser radiation (LILR) in particular. Aim. To evaluate the effectiveness of laser therapy (LT) in the complex correction of acute secondary pyelonephritis (ASP) in patients with single kidney stones according to the basic adaptation criteria of oxidative-antioxidant clinical medicine КЛИНИЧЕСКАЯ МЕДИЦИНА homeostasis of the organism. Materials and methods. Indices of endogenous intoxication (EI), characterizing the oxidative-antioxidant homeostasis of the body in ASP, were studied in 96 patients with nephrolithiasis aged 19 to 40 years. Patients of the comparison group (48 people) underwent basic (according to the standards) treatment aimed at controlling of calculous pyelonephritis. Patients of the main group (48 people) in the traditional conservative therapy from the second day of hospitalization daily received additional LT sessions with apparatus LTA “Uzor-3KS” with a frequency of 0.6 kHz, a power of 1.5 watts within 4 minutes (total for treatment course is eight procedures). The effectiveness of therapy was assessed on the 5th and 9th day of the inpatient stay. Results. It was found that endotoxicosis in non-destructive forms of ASP is caused by the increase in the concentration of malonic dialdehyde of plasma (by 20.3%) and erythrocytes (by 35.5%), decrease in catalase activity (by 14.2%) and the amount of total (by 11.8%) and free (21.1%) thiol groups with a decrease in the detoxification index (DI) by 24,1%. Compared with the baseline therapy (BT), the effectiveness of LT in the complex treatment of ASP in the analyzed parameters of metabolic homeostasis against the background of the increase in catalase capacity from 6.9 to 10.2%, the detoxification index from 5 to 12.5% was 7.5% (on the 5th day) and 17.5% (on the 9th day of treatment). Conclusions. ASP leads to activation of ROS, suppression of antioxidant and catalase activity of blood, reduction of DI, indicating a subcompensated syndrome of EI. Standard therapy contributes to the normalization of ROS and SLA values of body protection and reduces the level of endotoxicosis caused by ASP. Additional inclusion in the complex treatment of LT sessions more significantly normalizes redox metabolic homeostasis and EI parameters, improving the effectiveness of basic therapy.

scholarly journals Chemiluminescence Studies of Lipoperoxidation Processes in Arterial Hypertension and Stress

2019 ◽  
Vol 4 (1) ◽  
pp. 133-137
Author(s):  
Anastasiya S. Brichagina ◽  
Mariya I. Dolgikh ◽  
Larisa R. Kolesnikova ◽  
Larisa V. Natyaganova
Keyword(s):  
Lipid Peroxidation ◽  
Free Radical ◽  
Free Radical Oxidation ◽  
The State ◽  
Male Rats ◽  
Antioxidant Protection ◽  
Radical Oxidation ◽  
Biochemical Methods ◽  
Peroxidation Processes

Various pathologies, in particular hypertension, accompany violation of the processes of free radical oxidation. The state of the system lipid peroxidation – antioxidant protection can be assessed only by a complex of biochemical methods. The chemiluminescent method is used to obtain a faster result. The method has a number of advantages: measurement of chemiluminescence parameters is carried out in natural conditions and does not require sample preparation, is highly selective, it can be used to identify the presence of free radical pathology, analysis of the intensity of lipid peroxidation processes, the effectiveness of treatment with antioxidant medicament. The aim of the research was to study the lipid peroxidation under hypertension and stress by chemiluminescence. The experiment was conducted on male rats of the ISIAH line. The experiment consisted of 2 stages: stage of alarm and stage of chronic stress. We found that, depending on the type of stress, the state of the system lipid peroxidation-antioxidant protection differed. The role of stress in violation of the processes of lipoperoxidation in hypertension was established. The efficacy of the chemiluminescence method as an alternative to a complex of biochemical methods is shown. Express assessment of pro- and antioxidant status is possible for patients with hypertension.

scholarly journals Correction of antioxidant protection of cows organism in theperiod of laboratory drugs with content of non-participants of metals

2018 ◽  
Vol 20 (83) ◽  
pp. 204-207
Author(s):  
I.B. Kobilyukh
Keyword(s):  
Antioxidant System ◽  
Free Radical Oxidation ◽  
The Body ◽  
Control Group ◽  
Antioxidant Protection ◽  
Dry Period ◽  
Diene Conjugates ◽  
Radical Oxidation ◽  
Black And White ◽  
White Breed

The enhancement of free radical oxidation, characteristic of inflammatory processes, is accompanied by a violation of the properties of biological membranes, the functioning of cells and damage to surrounding tissues. The purpose and task of the research was to make correction of antioxidant protection of the body of cows during the period of dry preparations containing nanoparticles of metals. To activate the antioxidant system of the body of cows during the dry period, use the vitamin complex «Nanovit». The experiment was conducted on cows of Ukrainian dairy black-and-white breed in Agroprodservice-Invest LLP of the Kozivsky District of the Ternopil Oblast. The experiment was conducted before 35–25 days to the calves birth where the experimental and control groups of cows were formed (n = 10). Cows of the experimental group for 35–25 days to the cattle, intramuscularly injected 5.0 ml vitamin complex «Nanovit» (composition: vitamins A, D, E and nanoparticles Cu, Zn, Mn, Co). Producer of «NVP» LLC «Ecological Capital». Cows of the control group for 35–25 days to the catheter, intramuscularly administered 15.0 ml of the drug Prodevit-tetra (1 ml of the preparation contains vitamin A – 50000 IU, vitamin D – 25000 IU, vitamin E – 20 mg, vitamin F – 6 mg). Manufacturer of Product Ltd. The study found that vitamins A, D, E, and nanoparticles Cu, Zn, Mn, Co, which are part of the drug «Nanovit», activate the antioxidant system of the body of cows during the dry period. So after the application of the drug «Nanovit» in the body of cows there was a decrease of 58.5% (Р ≤ 0.01) of diene conjugates and 95.0% (Р ≤ 0.001) of TBK-active products against the background of an increase of 20.0% (Р ≤ 0.01) activity of catalase. After the application of the drug «Nanovit», the service period of the period from cows decreased by 54 days, and the index of insemination decreased by 0.2 units against the cows fed «Prodevit-tetra», indicating a positive effect of the drug containing the nanoparticles of metals Cu, Zn, Mn, Co and vitamins A, D, E during the post-period period in cows.

scholarly journals Influence of the preparation “Bendamin” on the indicators of antioxidant protection of rat myocardium in experimental modeling of heart failure

2019 ◽  
Vol 21 (95) ◽  
pp. 98-101
Author(s):  
I. S. Varkholiak ◽  
B. V. Gutyj
Keyword(s):  
Intraperitoneal Administration ◽  
Clinical Signs ◽  
Free Radical Oxidation ◽  
Feed Additives ◽  
Control Group ◽  
Standard Diet ◽  
Antioxidant Protection ◽  
Diene Conjugates ◽  
Radical Oxidation ◽  
Experimental Group

The aim of this study was to investigate the effect of Bendamin on the antioxidant status of rats in experimental doxorubicin-induced cardiomyopathy. The studies were performed on white sexually mature young male of Vistar line rats weighing 180–200 g, which were kept on a standard diet of the Institute Vivarium of the State Research Institute of Veterinary Drugs and Feed Additives. Animals were divided into 3 groups of 6 animals in each: control group – intact animals; experimental group R1, in which animals were simulated with doxorubicin-induced cardiomyopathy by intraperitoneal administration of doxorubicin at a dose of 2.5 mg/kg 3 times a week for two weeks; experimental group R2, in which animals were injected with the drug “Bendamin” at a dose of 20 mg/kg after injection of doxorubicin. The data obtained indicate that the introduction into the experimental animals of the experimental group of doxorubicin is accompanied by intensification in the myocardium of the processes of free radical oxidation. The increase in diene conjugates was found to be 32.7% and TBK-active products increased by 37.6% compared to the control group of rats. Doxorubicin was also found to cause inhibition of the glutathione system of the animal's antioxidant protection after administration to rats. After administration of the drug “Bendamin”, rats of the second experimental group were suppressed with lipid peroxidation under the conditions of doxorubicin intoxication. In the rats of the second experimental group, the level of intermediates and end products is likely to decrease, so in the rat myocardial homogenate the level of diene conjugates decreased by 16.8% and the level of TBA-active products by 20.8% compared to the first experimental group. who had clinical signs of cardiomyopathy caused by doxorubicin administration. The use of the drug “Bendamin” in rats of the second experimental group contributed to the enhancement of the enzymatic and non-enzymatic element of the antioxidant system, protecting the structural and functional integrity of cell bioembranes. The results of the studies enrich the pharmacological characteristics of the drug “Bendamin”, indicate its sufficiently clear protective effect on the myocardium in experimental doxorubicin cardiomyopathy and is a convincing proof of the feasibility of the drug in veterinary practice.

scholarly journals INVESTIGATING EFFECTS OF 7,8-DISUBSTITUTED DERIVATIVE OF THEOPHYLLINE (BENOPHYLLINE) ON FREE-RADICAL OXIDATION IN RENAL INJURY OF RATS

2020 ◽  
Vol 20 (1) ◽  
pp. 29-35
Author(s):  
A. P. Matviiychuk ◽  
R. F. Yeremenko ◽  
A. V. Matviiychuk ◽  
A. V. Taran ◽  
O. M. Hladchenko
Keyword(s):  
Free Radical ◽  
Renal Injury ◽  
Water Solution ◽  
Rat Kidney ◽  
Free Radical Oxidation ◽  
Antioxidant Protection ◽  
Radical Oxidation ◽  
Disubstituted Derivative ◽  
Test Kit ◽  
The Mean

This article highlights the pharmacological study of new 7,8-disubstituted derivative of theophylline, the substance conditionally named benophylline. Based on the literature data and previous studies of compounds of this class, it has been concluded that studying the effect of benophylline on the pro-antioxidant system under simulated pathologies is of great interest and importance.  The study of antihypoxic action of 7,8-disubstituted theophylline in rats was carried out under modelled normobaric hypoxia with hypercapnia (in an enclosed space). It has been found out the application of 7-n-methylbenzyl-8-substituted polyphosphonates increases the longevity of rats in the conditions described above that evidences the improvement of metabolic processes in mitochondrial respiratory chain. Based on the results of screening studies, we selected 7,8-disubstituted derivative of theophylline (benophylline) as a leading substance for further investigation. The purpose of the study was to evaluate the efficacy of benophylline for the pharmacological correction of free radical processes in experimental renal damage in rats based on the evaluation of the expression of lipid peroxidation and antioxidant protection. Materials and methods: blood serum, homogenate and rat kidney tissues were the study materials. The study of the protective effect of benophylline on the functional state of the kidneys was investigated on experimental model of acute renal injury by introducing 50% water solution of glycerol (myoglobin nephropathy). Pathogenesis of this model was described in the methodological recommendations by C. Yu. Shtrygol, V. M. Lysovoi, I. A. Zupanetz et al. in «Methods of experimental modeling of kidney damage for pharmacological research». The content of TBK-R was determined spectrophotometrically by reaction with thiobarbituric acid. Glutathione recovered activity was determined spectrophotometrically in reaction with Elman's reagent using the method of Beutler E. D. et al. The catalase activity was assessed by the method of M.A. Koroluk et al. The influence of benophylline on the morphological state of the renal parenchyma was assessed on the modeled myoglobin nephropathy. The activity of gamma-glutamyltranspeptidase in serum was evaluated photometrically using a reagent test kit (“Filisit”). Statistical processing of the results was performed using the STATISTICA 8.0 software package, with the mean value, standard error of the mean confidence interval (p≤0.05). The microscopic study of microproducts was performed under the Granum microscope. Micrographs were taken with a Granum DMC 310 digital camera. The images were processed on a Pentium 2.4 GHz computer using Toup View software. Research results: Under the influence of benophylline, the processes of LPO and AOP became normalized, the expressiveness of degradation of the nephrocytes decreased, the microscopic picture of renal excretion in all rats got normalized. At the same time, 62.5% of the rats had the morphological condition of kidneys close to the intact control, and 37.5% of the animals were noticed to demonstrate a significant decrease in the dyscirculatory abnormalities, inflammatory manifestations and signs of nephrocyte regeneration. Conclusions: The ability of benophylline to inhibit the processes of free radical oxidation and to enhance antioxidant protection has been found out. The study has shown benophylline enhances regenerative effect kidney tissues.

High-resolution Geomagnetic Field Records Decipher the Possible Precession links since about 340-kyr in a maar lake sediment sequence in tropical Asia

2020 ◽  
Author(s):  
Xiaoqiang Yang ◽  
Cong Chen ◽  
Zhuo Zheng
Keyword(s):  
Magnetic Field ◽  
High Resolution ◽  
Geomagnetic Field ◽  
Southern China ◽  
Singular Spectrum Analysis ◽  
Luminescence Dating ◽  
Large Spatial Scale ◽  
The Earth ◽  
Earth Magnetic Field ◽  
Maar Lake

<p>A series of paleomagnetic works relying on the ocean sediments present some significant astronomic periods, such as a 100 kyr quasi-period and 41 kyr obliquity signal. These studies provide the new insights unscrambling what and how the earth magnetic field changed in despite of the ongoing debating. Numerical studies of recent years also reveal the possibility of the precession drive the dynamos and influence the magnetic field. However, the less of reliable high-resolution paleomagnetic records besides of relative paleointensity reduce its credibility. Here, we present some detailed rock magnetic and paleomagnetic studies on the continuous 40-m-thick sediments in two parallel cores retrieved from Tianyang Maar lake, southern China. The new results would contribute to discuss the correlation of paleomagnetic field with the astronomical factors.</p><p>Tianyang Maar lake  is located in the southern part of the Leizhou Peninsula.  The maar lake has a surface area of ~ 7.3 km<sup>2</sup> surrounded by a 40 - 60 m high crater rim composed of basaltic breccia and tuff . Two new parallel cores, TY08 and TY15 (~ 10 m apart), were extracted from center of the crater in 2008 and 2015, respectively, using a rotary borer consisting of a stainless steel outer tube and a plastic inner tube to minimize sediment disturbances and contamination. The sediments of two cores can divided into three zones: about upper 15.59 m was composed of varying colors clay and the middle part (15.59-21.94 m), was dominated by the grey and greyish-brown fine to coarse sand with occasional gravels, embedded a thick grey clay layer; the lower part (21.94-40.0 m) shown as the dark grey and black organic-rich clay.</p><p>The paleomagnetic results show that the natural remanent magnetization (NRM) of the sediments is mainly contributed by magnetically soft minerals, and the sediments have fairly documented geomagnetic field variations. A chronology is constructed using multiple methods, including radiocarbon dating, optically stimulated luminescence dating and terrestrial-marine pollen correlation. The 340-kyr paleomagnetic inclination record displays patterns similar to those seen in regional records over a large spatial scale (> 3000 km), implying that these records may reflect large-scale core dynamics on timescales of 10<sup>4 </sup>- 10<sup>5</sup> years in this low-latitude region. The Tianyang inclination record exhibits a negligible inclination anomaly (∆I = -0.08°) and features six anomalous inclination events, which are assigned to the Laschamp, Blake, Fram Strait II/6α, Iceland Basin, Mamaku and 9α excursions respectively. The spectral and singular spectrum analysis (SSA) exhibit that the inclination does not show the significant signal of 100-kyr periodicity, however, the closed precession period is obvious in the third components of inclination (PC3). PC3 component shows nearly synchronous variations with the precession parameter while the opposite correlation appeared under the condition of eccentricity minima strong. This corresponding pattern hint us that astronomical parameters have the essential influence to the earth magnetic field, however, the different moving may forc or constrain the earth magnetic behavior.</p>

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