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1.
Extremely low-frequency electromagnetic fields (ELF-EMFs) can affect male reproductive function, but the underlying mechanism of this effect remains unknown. miRNA-mediated regulation has been implicated as an important epigenetic mechanism for regulatory pathways. Herein, we profiled miRNA expression in response to ELF-EMFs in vitro. Mouse spermatocyte-derived GC–2 cells were intermittently exposed to a 50 Hz ELF-EMF for 72 h (5 min on/10 min off) at magnetic field intensities of 1 mT, 2 mT and 3 mT. Cell viability was assessed using the CCK–8 assay. Apoptosis and the cell cycle were analyzed with flow cytometry. miRNA expression was profiled using Affymetrix Mouse Genechip miRNA 3.0 arrays. Our data showed that the growth, apoptosis or cell cycle arrest of GC–2 cells exposed to the 50 Hz ELF-EMF did not significantly change. However, we identified a total of 55 miRNAs whose expression significantly changed compared with the sham group, including 19 differentially expressed miRNAs (7 miRNAs were upregulated, and 12 were downregulated) in the 1 mT exposure group and 36 (9 miRNAs were upregulated, and 27 were downregulated) in the 3 mT exposure group. The changes in the expression of 15 selected miRNAs measured by real-time PCR were consistent with the microarray results. A network analysis was used to predict core miRNAs and target genes, including miR-30e-5p, miR-210-5p, miR-196b-5p, miR-504-3p, miR-669c-5p and miR-455-3p. We found that these miRNAs were differentially expressed in response to different magnetic field intensities of ELF-EMFs. GO term and KEGG pathway annotation based on the miRNA expression profiling results showed that miRNAs may regulate circadian rhythms, cytokine-cytokine receptor interactions and the p53 signaling pathway. These results suggested that miRNAs could serve as potential biomarkers, and the miRNA-mediated regulation of signaling pathways might play significant roles in the biological effects of ELF-EMFs.  相似文献   

2.
Some effects of extremely low frequency electromagnetic fields (ELF-EMFs) on human spermatozoa are reported. Significant increases in the values of the motility and of the other kinematic parameters have been observed when spermatozoa were exposed to an ELF-EMF with a square waveform of 5 mT amplitude and frequency of 50 Hz. By contrast, a 5 mT sine wave (50 Hz) and a 2.5 mT square wave (50 Hz) exposure did not produce any significant effect on sperm motility. The effects induced by ELF-EMF (50 Hz; 5 mT) during the first 3 h of exposure persisted for 21 h after the end of the treatment. These results indicate that ELF-EMF exposure can improve spermatozoa motility and that this effect depends on the field characteristics.  相似文献   

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4.
Exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) can enhance hippocampal neurogenesis in adult mice. However, little is focused on the effects of ELF-EMFs on embryonic neurogenesis. Here, we studied the potential effects of ELF-EMFs on embryonic neural stem cells (eNSCs). We exposed eNSCs to ELF-EMF (50 Hz, 1 mT) for 1, 2, and 3 days with 4 hours per day. We found that eNSC proliferation and maintenance were significantly enhanced after ELF-EMF exposure in proliferation medium. ELF-EMF exposure increased the ratio of differentiated neurons and promoted the neurite outgrowth of eNSC-derived neurons without influencing astrocyes differentiation and the cell apoptosis. In addition, the expression of the proneural genes, NeuroD and Ngn1, which are crucial for neuronal differentiation and neurite outgrowth, was increased after ELF-EMF exposure. Moreover, the expression of transient receptor potential canonical 1 (TRPC1) was significantly up-regulated accompanied by increased the peak amplitude of intracellular calcium level induced by ELF-EMF. Furthermore, silencing TRPC1 expression eliminated the up-regulation of the proneural genes and the promotion of neuronal differentiation and neurite outgrowth induced by ELF-EMF. These results suggest that ELF-EMF exposure promotes the neuronal differentiation and neurite outgrowth of eNSCs via up-regulation the expression of TRPC1 and proneural genes (NeuroD and Ngn1). These findings also provide new insights in understanding the effects of ELF-EMF exposure on embryonic brain development.  相似文献   

5.
Following an increase in the use of electric appliances that can generate 50 or 60 Hz electromagnetic fields, concerns have intensified regarding the biological effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on human health. Previous epidemiological studies have suggested the carcinogenic potential of environmental exposure to ELF-EMFs, specifically at 50 or 60 Hz. However, the biological mechanism facilitating the effects of ELF-EMFs remains unclear. Cellular studies have yielded inconsistent results regarding the biological effects of ELF-EMFs. The inconsistent results might have been due to diverse cell types. In our previous study, we indicated that 1.5 mT, 60 Hz ELF-EMFs will cause G1 arrest through the activation of the ATM-Chk2-p21 pathway in human keratinocyte HaCaT cells. The aim of the current study was to investigate whether ELF-EMFs cause similar effects in a distinct epidermal keratinocyte, primary normal human epidermal keratinocytes (NHEK), by using the same ELF-EMF exposure system and experimental design. We observed that ELF-EMFs exerted no effects on cell growth, cell proliferation, cell cycle distribution, and the activation of ATM signaling pathway in NHEK cells. We demonstrated that the 2 epidermal keratinocytes responded to ELF-EMFs differently. To further validate this finding, we simultaneously exposed the NHEK and HaCaT cells to ELF-EMFs in the same incubator for 168 h and observed the cell growths. The simultaneous exposure of the two cell types results showed that the NHEK and HaCaT cells exhibited distinct responses to ELF-EMFs. Thus, we confirmed that the biological effects of ELF-EMFs in epidermal keratinocytes are cell type specific. Our findings may partially explain the inconsistent results of previous studies when comparing results across various experimental models.  相似文献   

6.
Environmental exposure to extremely low-frequency electromagnetic fields (ELF-EMFs) has been implicated in the development of cancer in humans. An important basis for assessing a potential cancer risk due to ELF-EMF exposure is knowledge of biological effects on human cells at the chromosomal level. Therefore, we investigated in the present study the effect of intermittent ELF electromagnetic fields (50 Hz, sinusoidal, 5'field-on/10'field-off, 2-24 h, 1 mT) on the induction of micronuclei (MN) and chromosomal aberrations in cultured human fibroblasts. ELF-EMF radiation resulted in a time-dependent increase of micronuclei, which became significant after 10 h of intermittent exposure at a flux density of 1 mT. After approximately 15 h a constant level of micronuclei of about three times the basal level was reached. In addition, chromosomal aberrations were increased up to 10-fold above basal levels. Our data strongly indicate a clastogenic potential of intermittent low-frequency electromagnetic fields, which may lead to considerable chromosomal damage in dividing cells.  相似文献   

7.
Protein phosphorylation is an extremely important and widely used mechanism of cellular regulation. Here, the effects of 50 Hz magnetic fields (MFs) on tyrosine phosphorylation were studied. A Chinese hamster lung (CHL) cell line was exposed to 50 Hz magnetic fields at two intensities (0.4 mT and 0.8 mT) for different exposure durations, and western blot analysis was used to measure the degree of tyrosine phosphorylation of cellular proteins. Results showed that both 0.4 mT and 0.8 mT 50 Hz magnetic fields could affect the protein tyrosine phosphorylation in cultured cells. Both intensities could affect the tyrosine phosphorylation of 38 and 97.4 kDa proteins. In addition, 0.4 mT could affect tyrosine phosphorylation of 61.7, 105, and 112 kDa proteins, and 0.8 mT affected the tyrosine phosphorylation of 79 and 150 kDa proteins. Moreover, all the tyrosine phosphorylation changes of these proteins were time-dependent. The findings from this study demonstrated that under these experimental conditions, there was evidence that protein tyrosine phosphorylation was a possible process for ELF-EMF producing bioeffects.  相似文献   

8.
Atherosclerosis (AS) is one of the principal causes of cardiovascular disorder. Reportedly, vascular smooth muscle cells (VSMCs) and human umbilical vein endothelial cells (HUVECs) play key roles in AS development, and microRNAs (miRNAs) regulate their functions. The function of miR-216b-5p in AS remains unknown. Human VSMCs and human HUVECs were treated with ox-LDL to establish the in vitro model of AS. MiR-216b-5p and IGF2 expressions in VSMCs and HUVECs were probed by qRT-PCR and western blot. The viability, cell cycle progression, and apoptosis of VSMCs and HUVECs were evaluated by Cell Counting Kit-8 (CCK-8), 5-ethynyl-2′-deoxyuridine, and flow cytometry assays, respectively. The binding sites between IGF2 3′UTR and miR-216b-5p were validated by dual-luciferase reporter assay. miR-216b-5p expression was declined in ox-LDL-induced VSMCs and HUVECs. In VSMCs, miR-216b-5p overexpression inhibited excessive proliferation and induced apoptosis. MiR-216b-5p could markedly restrain the viabiblity of VSMCs induced by ox-LDL and enhanced the viability of HUVECs. Additionally, IGF2 was confirmed as the direct target of miR-216b-5p and transfection of IGF2 overexpression plasmids rescued the effects of miR-216b-5p on VSMCs and HUVECs. miR-216b-5p alleviates the dysfunction of VSMCs and HUVECs caused by ox-LDL via repressing IGF2, and exerts protective functions to block the development of AS.  相似文献   

9.
BackgroundHepatocellular carcinoma (HCC) is a common tumor malignancy threatening a significant number of people worldwide. Although microRNAs (miRNAs) have been shown to play essential role in tumorigenesis, little is known about their role in T cells functions during HCC progression.MethodsThe abundances of miR-26b-5p were detected in HCC tissues or cells, T cells and H22 cells by quantitative real-time polymerase chain reaction (qRT-PCR). Regulation effect of miR-26b-5p on proviral integrations of moloney virus 2 (PIM2) was investigated by qRT-PCR, western blot (WB) and immunohistochemical analysis. The effect of miR-26b-5p and PIM-2 on cytokines secretion in CD4+ and CD8+ cells was evaluated by commercial enzyme linked immunosorbent assays (ELISA) kit. The interaction between miR-26b-5p and PIM-2 was probed by luciferase activity and RNA immunoprecipitation (RIP). H22 subcutaneous model was established to investigate the interaction of miR-26b-5p with HCC and immune competence.ResultsThe abundance of miR-26b-5p was decreased in HCC and associated with poor survival. Addition of miR-26b-5p contributed to secretion of tumor necrosis factor α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6) and IL-2 in CD4+ and CD8+ cells. Interestingly, PIM-2 was negatively regulated by miR-26b-5p and PIM-2 knockdown reversed anti-miR-26b-5p-mediated immunosuppression. Moreover, inhibitory effect of miR-26b-5p on HCC tumorigenesis was dependent on immune competence.ConclusionsmiR-26b-5p enhanced T cells responses by targeting PIM-2 in HCC, uncovering a promising therapeutic opportunity of HCC through reactivating immune system.  相似文献   

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There is limited research on the effect of electromagnetic field on aquatic organisms, especially freshwater fish species. This study was conducted to evaluate the effect of extremely low frequency electromagnetic field (ELF-EMF) (50 Hz) exposure on brain histopathology of Cyprinus carpio, one of the important species of Caspian Sea with significant economic value. A total of 200 healthy fish were used in this study. They were classified randomly in two groups: sham-exposed group and experimental group, which were exposed to five different magnetic field intensities (0.1, 1, 3, 5, and 7 mT) at two different exposure times (0.5 and 1 h). Histologic results indicate that exposure of C. carpio to artificial ELF-EMF caused severe histopathological changes in the brain at field intensities ≥3 mT leading to brain necrosis. Field intensity and duration of exposure were key parameters in induction of lesion in the brain. Further studies are needed to elucidate exact mechanism of EMF exposure on the brain.  相似文献   

12.
In chronic alcoholism, brain shrinkage and cognitive defects because of neuronal death are well established, although the sequence of molecular events has not been fully explored yet. We explored the role of microRNAs (miRNAs) in ethanol-induced apoptosis of neuronal cells. Ethanol-sensitive miRNAs in SH-SY5Y, a human neuroblastoma cell line, were identified using real-time PCR-based TaqMan low-density arrays. Long-term exposure to ethanol (0.5% v/v for 72 h) produced a maximum increase in expression of miR-497 (474-fold) and miR-302b (322-fold). Similar to SH-SY5Y, long-term exposure to ethanol induced miR-497 and miR-302b in IMR-32, another human neuroblastoma cell line. Using in silico approaches, BCL2 and cyclin D2 (CCND2) were identified as probable target genes of these miRNAs. Cotransfection studies with 3'-UTR of these genes and miRNA mimics have demonstrated that BCL2 is a direct target of miR-497 and that CCND2 is regulated negatively by either miR-302b or miR-497. Overexpression of either miR-497 or miR-302b reduced expression of their identified target genes and increased caspase 3-mediated apoptosis of SH-SY5Y cells. However, overexpression of only miR-497 increased reactive oxygen species formation, disrupted mitochondrial membrane potential, and induced cytochrome c release (mitochondria-related events of apoptosis). Moreover, ethanol induced changes in miRNAs, and their target genes were substantially prevented by pre-exposure to GSK-3B inhibitors. In conclusion, our studies have shown that ethanol-induced neuronal apoptosis follows both the mitochondria-mediated (miR-497- and BCL2-mediated) and non-mitochondria-mediated (miR-302b- and CCND2-mediated) pathway.  相似文献   

13.
Various studies have reported that Huaier possesses anti-tumor effects. However, the mechanisms are not completely elucidated. Here, we found 66 differentially expressed miRNAs in Huaier-treated pulmonary adenocarcinoma A549 cells, with upregulation of miR-26b-5p. Transfection of A549 cells with miR-26b-5p mimic inhibited proliferation and induced apoptosis, while transfection of Huaier-treated A549 cells with a miR-26b-5p inhibitor reversed the effects of Huaier. EZH2 was verified as the target of miR-26b-5p. Thus, our findings indicate that Huaier might suppress proliferation and induce apoptosis in lung cancer cells via a miR-26b-5p-EZH2-mediated approach, which provides a new perspective for understanding the anti-tumor effects of Huaier.  相似文献   

14.
The issue of adverse health effects of extremely low-frequency electromagnetic fields (ELF-EMFs) is highly controversial. Contradictory results regarding the genotoxic potential of ELF-EMF have been reported in the literature. To test whether this controversy might reflect differences between the cellular targets examined we exposed cultured cells derived from different tissues to an intermittent ELF-EMF (50 Hz sinusoidal, 1 mT) for 1-24h. The alkaline and neutral comet assays were used to assess ELF-EMF-induced DNA strand breaks. We could identify three responder (human fibroblasts, human melanocytes, rat granulosa cells) and three non-responder cell types (human lymphocytes, human monocytes, human skeletal muscle cells), which points to the significance of the cell system used when investigating genotoxic effects of ELF-EMF.  相似文献   

15.
Recently, circulating miRNAs have been reported as promising biomarkers for various pathologic conditions including cancer. Certain microRNAs (miRNAs) have been shown early diagnostic potential for many types of cancer. The objective of this study was to investigate the potential of certain serum/plasma miRNAs as novel non-invasive biomarkers for early diagnosis of hepatitis B virus (HBV) related hepatocellular carcinoma (HCC). For this reason, the expression levels of 24 miRNA (let-7c, miR-92a-3p, 423-5p, 150-5p, 223-3p, 125b-5p, 342-3p, miR-206, 122-5p, 375, 223-5p, 10a-5p, 23b-5p, 99a-5p, 23a-5p, 10a-3p, 122-3p, 125b-1-3p, 23b-3p, 125b-2-3p, 23a-3p, 92a-1-5p, 92a-2-5p, 99a-3p) were analyzed in plasma of patients with chronic hepatitis B, HBV-positive cirrhosis and HBV-positive HCC and compared with control group samples. Totally 94 plasma samples; 28 control and 66 patient plasma (24 CHB, 22 HBV-positive cirrhosis, 20 HBV-positive HCC) and were included in this study. The expression levels of 24 miRNAs were detected for all control and patient group plasma samples by qRT-PCR using BioMark? 96.96 Dynamic Array (Fluidigm Corporation) system. The expression levels of miR-125b-5p were detected 2.85 fold, 2.46 fold and 1.89 fold (p = 0.01513, p = 0.0009440, p = 0.0001446) up regulated in CHB, HBV-positive cirrhosis and HBV-positive HCC, respectively when compared versus control group individually by Mann–Whitney U test. The expression levels of miR-223-3p were detected 5.55 fold, 13.88 fold and 12.65 fold (p = 0.01513, p = 0.0009440, p = 0.0001446) down regulated in same comparisons. When all groups were compared versus control group by one-way ANOVA test, the expression levels of miR-223-3p were also found statistically significant (p < 0.05). Although not statistically significant, miR-125b-5p tended to be upregulated. (p = 0.07192). These results significantly imply that miR-125b-5p and miR223-3p could be used as novel non-invasive biomarkers of HBV-positive HCC in very early, even at CHB stage of liver disease.  相似文献   

16.
Diabetes mellitus (DM) induces a variable degree of muscle sarcopenia, which may be related to protein degradation and to the expression of both E3 ubiquitin ligases and some specific microRNAs (miRNAs). The present study investigated the effect of diabetes and acute muscle contraction upon the TRIM63 and FBXO32 expression as well as the potential involvement of some miRNAs. Diabetes was induced by streptozotocin and studied after 30 days. Soleus muscles were harvested, stimulated to contract in vitro for twitch tension analysis (0.5 Hz), 30 min later for tetanic analysis (100 Hz), and 30 min later were frozen. TRIM63 and FBXO32 proteins were quantified by western blotting; Trim63 mRNA, Fbxo32 mRNA, miR-1-3p, miR-29a-3p, miR-29b-3p, miR-133a-3p, and miR-133b-3p were quantified by qPCR. Diabetes induced sarcopenia by decreasing (P < 0.05) muscle weight/tibia length index, maximum tetanic contraction and relaxation rates, and absolute twitch and tetanic forces (P < 0.05). Diabetes decreased (P < 0.05) the Trim63 and Fbxo32 mRNAs (30%) and respective proteins (60%), and increased (P < 0.01) the miR-29b-3p (2.5-fold). In muscle from diabetic rats, acute contractile stimulus increased TRIM63 protein, miR-1-3p, miR-29a-3p, and miR-133a/b-3p, but decreased miR-29b-3p (P < 0.05). Independent of the metabolic condition, after muscle contraction, both TRIM63 and FBXO32 proteins correlated significantly with miR-1-3p, miR-29a/b-3p, and miR-133a/b-3p. All diabetes-induced regulations were reversed by insulin treatment. Concluding, the results depict that muscle wasting in long-term insulinopenic condition may not be accompanied by increased proteolysis, pointing out the protein synthesis as an important modulator of muscle sarcopenia in DM.  相似文献   

17.
We identified 40 miRNAs with inherited aberrant expression by multiple parallel sequencing of human HeLa cells irradiated with X rays and mitomycin C. Twenty-two miRNAs were repressed and 15 miRNAs were induced after radiation and mytomycin C treatment. The expression of three miRNAs (miR-10b-5p, miR-148a-3p, and miR-340-5p) decreased after X-ray exposure and increased after mitomycin C treatment. The spectrum of aberrantly expressed miRNAs after X-ray and mitomycin C treatment is different, except for three miRNAs (mir-100-5p, miR-99b-5p, miR-501-3p), which showed the inherited decreased expression after both mutagens. It has been ascertained that for five miRNAs (miR-21-3p, miR-182-5p, miR-19b-3p, miR-30a-3p, and miR-30e-3p) with increased inherited expression, the targets are well-described tumor suppressor genes. For 9 miRNAs (miR-99b-5p, miR-148a-3p, miR-365a-3p, miR-193a-3p, miR-100-5p, miR-99a-5p, miR-29b-3p, miR-340-5p, and miR-23b-3p) with reduced inherited expression, the targets are oncogenes. The obtained results provide further support of the idea that induced epigenetic changes in the genome should be considered when assessing the long-term genetic effects of ionizing radiation and chemical compounds.  相似文献   

18.
Pan Z  Guo Y  Qi H  Fan K  Wang S  Zhao H  Fan Y  Xie J  Guo F  Hou Y  Wang N  Huo R  Zhang Y  Liu Y  Du Z 《PloS one》2012,7(3):e32571
The M(3) subtype of muscarinic acetylcholine receptors (M(3)-mAChR) plays a protective role in myocardial ischemia and microRNAs (miRNAs) participate in many cardiac pathophysiological processes, including ischemia-induced cardiac injury. However, the role of miRNAs in M(3)-mAChR mediated cardioprotection remains unexplored. The present study was designed to identify miRNAs that are involved in cardioprotective effects of M(3)-mAChR against myocardial ischemia and elucidate the underlying mechanisms. We established rat model of myocardial ischemia and performed miRNA microarray analysis to identify miRNAs involved in the cardioprotection of M(3)-mAChR. In H9c2 cells, the viability, intracellular free Ca(2+) concentration ([Ca(2+)]i), intracellular reactive oxygen species (ROS), miR-376b-5p expression level, brain derived neurophic factor (BDNF) and nuclear factor kappa-B (NF-κB) levels were measured. Our results demonstrated that M(3)-mAChR protected myocardial ischemia injury. Microarray analysis and qRT-PCR revealed that miR-376b-5p was significantly up-regulated in ischemic heart tissue and the M(3)-mAChRs agonist choline reversed its up-regulation. In vitro, miR-376b-5p promoted H(2)O(2)-induced H9c2 cell injuries measured by cells viability, [Ca(2+)]i and ROS. Western blot and luciferase assay identified BDNF as a direct target of miR-376b-5p. M(3)-mAChR activated NF-κB and thereby inhibited miR-376b-5p expression. Our data show that a novel M(3)-mAChR/NF-κB/miR-376b-5p/BDNF axis plays an important role in modulating cardioprotection. MiR-376b-5p promotes myocardial ischemia injury possibly by inhibiting BDNF expression and M(3)-mAChR provides cardioprotection at least partially mediated by the downregulation of miR-376b-5p through NF-κB. These findings provide new insight into the potential mechanism by which M(3)-mAChR provides cardioprotection against myocardial ischemia injury.  相似文献   

19.
ObjectiveThe role of exosomes in human cancers has been identified, while the effect of cancer-associated fibroblasts (CAFs)-derived exosomes (CAF-exos) transmitting microRNAs (miRNAs) on colorectal cancer (CRC) remains largely unknown. We aim to explore the impact of CAF-derived exosomal miR-135b-5p on CRC progression by targeting thioredoxin-interacting protein (TXNIP).MethodsCRC tissues were collected to obtain CAF-exos, which were used to co-culture with LoVo and HT29 cells. The effect of miR-135b-5p and TXNIP on the in vivo growth, in vitro proliferation, apoptosis, migration, invasion and angiogenesis of CRC cells. miR-135b-5p and TXNIP expression in exosomes and CRC cells were detected and their targeting relationship was confirmed.ResultsMiR-135b-5p was upregulated whereas TXNIP was downregulated in CRC tissues and cells. The CAF-exos and CAF-exos upregulating miR-135b-5p promoted in vivo growth, in vitro proliferation, migration and invasion, and suppressed apoptosis of CRC cells, and also promoted the HUVEC angiogenesis. TXNIP was confirmed as a target of miR-135b-5p and overexpression of TXNIP could weaken the pro-CRC effect of exosomal miR-135b-5p,ConclusionCAF-exos upregulate miR-135b-5p to promote CRC cell growth and angiogenesis by inhibiting TXNIP.  相似文献   

20.
Effects of applying extremely low-frequency electromagnetic fields (ELF-EMF) for different durations (24, 48, and 72 h) and different field intensities (0.1–1.0 mT) on micronucleus (MN) formation and induction of apoptosis were examined in a human squamous cell carcinoma cell line (SCL II) and in a human amniotic fluid cell line (AFC). A statistically significant increase of MN frequency and of induction of apoptosis in SCL II cells after 48-h and 72-h continuous exposure to 50 Hz magnetic field (MF) (0.8 and 1.0 mT) was found. However, exposure of AFC cells to EMF of different intensities and for different exposure times showed no statistically significant differences when compared with controls. These results demonstrate that different human cell types respond differently to EMF. Dose-dependent induction of apoptosis and genotoxic effects, resulting in increased micronucleus formation, could be demonstrated in the transformed cell line, whereas the nontransformed cell line did not show statistically significant effects. These findings suggest that EMF could be a promotor but not an initiator of carcinogenic effects. Bioelectromagnetics 19:85–91, 1998. © 1998 Wiley-Liss, Inc.  相似文献   

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