Cobalt-Mediated Defect Engineering Endows High Reversible Amorphous VS4 Anode for Advanced Sodium-Ion Storage.

Metal sulfides are promising anode materials for sodium-ion batteries (SIBs) due to their structural diversity and high theoretical capacity, but the severe capacity decay and inferior rate capability caused by poor structural stability and sluggish kinetics impede their practical applications. Herein, a cobalt-doped amorphous VS4 wrapped by reduced graphene oxide (i.e., Co0.5-VS4/rGO) is developed through a Co-induced defect engineering strategy to boost the kinetics performances. The as-prepared Co0.5-VS4/rGO demonstrates excellent rate capacities over 10 A g-1 and superior cycling stability at 5 A g-1 over 1600 cycles, which is attributed to the defects formed by Co doping, the formed amorphous structure and the robust rGO substrate. The great features of Co0.5-VS4/rGO anode are further confirmed in sodium-ion capacitors when the active carbon cathode is used. Additionally, the relationships between metal doping, the derived defects, the amorphous structure, and the sodium storage of VS4 are uncovered. This work provides deep insights into preparing amorphous functional materials and also probes the potential applications of metal sulfide-based electrode materials for advanced batteries.

Oxygen Vacancy and Interface Effect Adjusted Hollow Dodecahedrons for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) with special morphologies provide the geometric morphology and composition basis for the construction of platforms with excellent catalytic activity. In this work, cobalt-cerium composite oxide hollow dodecahedrons (Co/Cex-COHDs) with controllable morphology and tunable composition are successfully prepared via a high-temperature pyrolysis strategy using Co/Ce-MOFs as self-sacrificial templates. The construction of the hollow structure can expose a larger surface area to provide abundant active sites and pores to facilitate the diffusion of substances. The formation and optimization of phase interface between Co3O4 and CeO2 regulate the electronic structure of the catalytic site and form a fast channel favorable to electron transport, thereby enhancing the electrocatalytic oxygen evolution activity. Based on the above advantages, the optimized Co/Ce0.2-COHDs obtained an enhanced oxygen evolution reaction (OER) performance.

Unraveling the Intercorrelation Between Micro/Mesopores and K Migration Behavior in Hard Carbon.

Pore-structure design with increased ion-diffusion ability is usually regarded as an effective strategy to improve K-storage performance in hard carbon (HC). However, the relationship between porous structure and K+ migration behavior remains unclear and requires further exploration. Herein, a series of chemically activated hard carbon spheres (denoted as AHCSs) with controllable micro/mesopores structure are successfully synthesized to explore intercorrelation between micro/mesopores and K migration behavior. The experimental results indicate AHCSs have two different K+ storage ways, that is, adsorption behavior at high potential region and intercalation process at low potential region. These behaviors are closely related to the pores structure evolution: the micropores afford extra active sites for efficient K-ions adsorption, and therefore positive correlation between micropores and adsorption-contributed capacity is confirmed; the mesopores permit more K-ions intercalation/deintercalation by offering adequate pathways, and as a result positive correlations between mesopores and intercalation-contributed capacity as well as initial Coulombic efficiency are revealed. All these together contribute to achieving excellent reversible capacity, and exceptional rate capability with an ultra-long cycle lifespan in PIBs, and simultaneously exhibit a high energy density as well as considerable cycling stability for potassium-ion full cells. These results promote a fundamental understanding of K+ migration behaviors in hard carbon.

Recent progress in electrochemical performance of carbon-based anodes for potassium-ion batteries based on first principles calculations.

Carbonaceous materials and the composite materials of transition metals compounds in carbon matrix were widely used as anode for potassium-ion batteries (PIBs). During the research of these anode materials, first-principles calculations based on adsorption energy, density of states (DOSs) as well as diffusion energy barriers was regarded as an effectively approach to investigate their potassium storage mechanism. The underlying reasons for the improvement of electrochemical performance could be well illustrated via the corresponding calculations. Moreover, first-principles calculations also played a vital role to predict the material properties of electrodes before conducting experimental analysis. Hence, this review is to analyze in-depth the effect mechanism of K-adsorption energy, DOSs as well as diffusion energy barrier and so on for electrochemical performance of carbon-based anode materials. We summarized the corresponding research progress, the challenges of first principles calculations in PIBs, and proposed the corresponding strategies along with future perspectives for further development of carbon-based anode materials. This work not only can provide theoretical guidance for the development of anode materials with excellent physical and chemical properties, but also have reference significance for other energy storage systems.

A Porous Mooncake-Shaped Li4 Ti5 O12 Anode Material Modified by SmF3 and Its Electrochemical Performance in Lithium Ion Batteries.

Reasonably designing and synthesizing advanced electrode materials is significant to enhance the electrochemical performance of lithium ion batteries (LIBs). Herein, a metal-organic framework (MOF, Mil-125) was used as a precursor and template to successfully synthesize the porous mooncake-shaped Li4 Ti5 O12 (LTO) anode material assembled from nanoparticles. Even more critical, SmF3 was used to modify the prepared porous mooncake-shaped LTO material. The SmF3 -modified LTO maintained a porous mooncake-shaped structure with a large specific surface area, and the SmF3 nanoparticles were observed to be attach on the surface of the LTO material. It has been proven that the SmF3 modification can further facilitate the transition from Ti4+ to Ti3+ , reduce the polarization of electrode, decrease charge transfer impedance (Rct ) and solid electrolyte interface impedance (Rsei ), and increase the lithium ion diffusion coefficient (DLi ), thereby enhancing the electrochemical performance of LTO. Therefore, the porous mooncake-shaped LTO modified using 2 wt % SmF3 displays a large specific discharge capacity of 143.8 mAh g-1 with an increment of 79.16 % compared to pure LTO at a high rate of 10 C (1 C=170 mAh g-1 ), and shows a high retention rate of 96.4 % after 500 cycles at 5 C-rate.

Enabling Ultrastable Co-Free Li-Rich Oxides via TbF3 Treatment.

Co-free Li-rich Mn-based cathode materials (Co-free LRMOs) have become one of the most promising cathode materials in lithium-ion batteries for the next generation due to their low cost, high capacity, and environmental friendliness. Under high voltage, redox reactions involving anions can easily lead to various issues, including oxygen release, dissolution of transition metal elements (TMs), and structural collapse in these materials. The absence of the Co element further exacerbates this issue. Here, a simple one-step solid-phase reaction strategy is proposed to achieve nanoscale dual modification of the Co-free LRMOs with F and Tb doping. The dual modification has a relatively small impact on the cell parameters and Li+ diffusion ability of the LRMOs, leading to no significant improvement in its rate performance. The modified LRMOs only exhibited discharge capacities of 220.7, 200.1, 140.0, 115.5, and 90.9 mAh·g-1 at 0.1, 0.2, 1.0, 2.0, and 5.0 C, respectively. However, the modified Co-free LRMOs exhibit extremely strong structural stability and retain 95.1% of the initial capacity after 300 cycles, so far, the highest capacity retention rates among all Ni/Mn-based Li-rich materials. Mechanism studies have shown that the enhancement in structural stability of the Co-free LRMOs is attributed to the increased concentration of oxygen vacancies and Ni3+ ions through F doping. Furthermore, Tb doping not only hinders the release of O2 but also enhances the Li+ migration and electronic conductivity coefficient of the LRMOs.

Halide-mediated endogenous ZnO domain-confined etching strategy: Realizing superior potassium storage in carbon anode.

Coupling sites of nitrogen-dopants and intrinsic carbon defects (N/DC) are highly attractive to improve potassium-storage capacity and cycling stability, yet it is hard to effectively construct them. Herein, a novel strategy is proposed to establish abundant N/DC sites in N-doped carbon (ZIF8/NaBr-1-900) by pyrolyzing the mixture of metal-organic framework (ZIF8)/sodium bromide (NaBr). Systematic investigations disclose that the introduced NaBr can promote the full conversion of Zn-N4 moieties into zinc oxide (ZnO) via a "bait and switch" mechanism. Such formed endogenous ZnO can etch the carbon matrix of the confined domains around the N dopants during pyrolysis process, and meanwhile the released N-atoms from Zn-N4 moieties can largely form edge-N. As such, these N/DC coupling sites enable the resultant carbon to have a more significant capacitive behavior related to fast K-ion migration and high structural stability, leading to 255.3 mAh/g at 2 A/g with a prolonged cycle lifespan over 2000 cycles. Moreover, the assembled K-full battery presents a high energy density of 171.2 Wh kg-1 and excellent cyclability over 5000 cycles. This NaBr-mediated endogenous ZnO domain-confined etching strategy provides a new insight into the exploration of advanced carbon anode.

Texture and Magnetic Property of Fe-6.5 wt % Si Steel Strip with Cu-Rich Particles Modification.

Based on the ordered phase effectively suppressed by rapid solidification technology, the grain refinement concept using Cu is incorporated into the soft magnetic materials. Cu dosage not only could refine the grain size with an average grain size of 8.7 µm but also improve the continuity and consistency of Fe-6.5 wt % Si steel strip. It mainly attributes to the Cu-rich particles precipitating at the grain boundary, nailing the grain boundaries movement and inhibiting the grain growth, and then improving the magnetic properties and mechanical properties. The 1.5 wt % Cu sample exhibits an excellent magnetic property with the saturation magnetization of 236.54 emu/g, which mainly attributes to the strong η, λ, Goss texture formation and the band structure optimization of Si-Cu comodification. Furthermore, the mechanical properties of the steel strip are effectively improved, and the failure plastic deformation of 1.5 wt % Cu steel strip is about 11%. The rapid solidification with Cu-dosage refinement technology also has a remarkable reference on the mechanical properties and magnetic properties modification of other metal materials.

Fundamental Understanding and Research Progress on the Interfacial Behaviors for Potassium-Ion Battery Anode.

Potassium-ion batteries (PIBs) exhibit a considerable application prospect for energy storage systems due to their low cost, high operating voltage, and superior ionic conductivity. As a vital configuration in PIBs, the two-phase interface, which refers to K-ion diffusion from the electrolyte to the electrode surface (solid-liquid interface) and K-ion migration between different particles (solid-solid interface), deeply determines the diffusion/reaction kinetics and structural stability, thus significantly affecting the rate performance and cyclability. However, researches on two-phase interface are still in its infancy and need further attentions. This review first starts from the fundamental understanding of solid-liquid and solid-solid interfaces to in-depth analyzing the effect mechanism of different improvement strategies on them, such as optimization of electrolyte and binders, heterostructure design, modulation of interlayer spacing, etc. Afterward, the research progress of these improvement strategies is summarized comprehensively. Finally, the major challenges are proposed, and the corresponding solving strategies are presented. This review is expected to give an insight into the importance of two-phase interface on diffusion/reaction kinetics, and provides a guidance for developing other advanced anodes in PIBs.

Enhanced electron transfer and ion storage in phosphorus/nitrogen co-doped 3D interconnected carbon nanocage toward potassium-ion battery.

Heteroatoms doping strategies are often considered to be an effective approach to provide rich active sites for capacitive-controlled potassium storage, and enlarged interspacing for intercalation process. However, the excess doping level will form a large number of sp3 defects and thus severely damage π-conjugated system, which is unfavorable for electron transfer. Herein, a P/N co-doped three-dimensional (3D) interconnected carbon nanocage (denoted as PN-CNC) is prepared with the help of a template-assisted method. The use of template and P heteroatom can contribute to forming a 3D interconnected carbon nanocage to prevent conductive carbon matrix from being excessively damaged, favoring a high electronic conductivity. The co-existence of P/N doping configurations with suitable content not only generate abundant defects, edge-voids, and micropores for significant capacitive behaviors, but also supply adequate interlayer space for intercalation process, and all these together ensure enhanced ion storage. As a result, the optimized PN-CNC electrode exhibits an exceptional reversible capacity (262 mAh g-1) and a superior rate capability (214.2 mAh g-1). Besides, long-term cycling stability is easily fulfilled by delivering a high capacity of 188.7 mAh g-1 at 2 A g-1 after 3000 cycles.

Intravenous rituximab therapy for active Graves' ophthalmopathy: a meta-analysis.

AIM: The successful treatment of Graves' ophthalmopathy (GO) remains a challenge, while the efficacy of rituximab (RTX) is at present controversial. The aim of this meta-analysis was to investigate the potential impact of intravenous RTX therapy in patients with GO. METHODS: We performed a search in the PubMed, Embase, and Web of Science databases for relevant studies published before July 2020. The primary outcome was the change of clinical activity score (CAS), and secondary outcomes were the change of proptosis and TSH receptor antibodies (TRAb). A meta-analysis was conducted to calculate the standard mean difference (SMD) for these outcomes by using fixed- or random-effect models. RESULTS: Analysis of outcomes in 152 patients collected from 12 published articles was conducted. Compared to baseline value, CAS was significantly decreased at 1, 6, 12, and >12 months after RTX treatment. For proptosis, the results revealed no significant decrease at 1-3, 6, and ≥12 months. Moreover, the pooled analysis employed in this meta-analysis showed no significant difference of TRAb at 1 month, but significant declines were observed at 6 and ≥12 months. CONCLUSION: Our results strongly suggest that intravenous RTX treatment has an acute and long-lasting beneficial effect on decreasing both CAS and TRAb. The study also indicates that the effect of RTX on proptosis is limited. There is evidently a need to investigate the mechanism behind RTX ineffectiveness on proptosis and explore other therapeutic regimens for the reduction of proptosis.

Efficacy and Safety of Different Intravenous Glucocorticoid Regimens in the Treatment of Graves' Ophthalmopathy: A Meta-Analysis.

PURPOSE: The intravenous glucocorticoid (iv GC) represents the mainstay of therapy for Graves' ophthalmopathy (GO), but uncertainty remains concerning the optimal regimen. Although the European Group on Graves' Orbitopathy (EUGOGO) regimen has been commonly employed, evidence for its superiority to other regimens is still lacking. The aim of this meta-analysis was to compare the efficacy and safety of the EUGOGO regimen with higher-dose regimens in the management of GO. METHODS: A systematic review and meta-analysis of randomized controlled trials (RCTs) and cohort studies comparing the EUGOGO regimen with higher-dose regimens was conducted. PubMed, Embase, and Web of Science databases were searched for relevant studies. The efficacy outcomes were response rate, change in clinical activity score (CAS), rate of proptosis improvement, and retreatment rate. The safety outcome was the incidence of adverse events. RESULTS: In the five included eligible trials, 136 participants in the EUGOGO regimen and 177 participants in higher-dose regimens were evaluated. Compared with the EUGOGO regimen, higher-dose regimens had no beneficial effect on the response rate, change of CAS, rate of proptosis improvement, and retreatment rate (OR: 1.3; 95% CI: 0.36-4.65; SMD: -0.04; 95% CI: -0.54, 0.45; OR: 0.79; 95% CI: 0.44-1.44; OR: 0.87; 95% CI: 0.27-2.77). For the incidence of adverse events, the results also showed no significant difference between the 2 groups (OR: 1.14; 95% CI: 0.62-2.09). CONCLUSION: The current evidence showed that the efficacy of the EUGOGO regimen was comparable with higher-dose regimens. Since there was no significant difference in the incidence of adverse events between the two regimens, appropriate selection of patients and careful monitoring were required in both regimens. More well-designed, large-scale, and longer follow-up period studies were needed to further verify the finding of this analysis.

Characterization of the Fe-6.5wt%Si Strip with Rapid Cooling Coupling Deep Supercooled Solidification.

The phase transition law between ordered and disordered phases, second phase reinforcement, microstructure, and mechanical properties were systematically studied in the rapid cooling coupling deep supercooled solidification process through an arc melting furnace, electromagnetic induction heating, and high-speed cooling single-roll technology. The results show that uniform nucleation and grain refinement are promoted under rapid cooling coupling deep supercooled solidification, and the phase transition from the disordered phase (A2) to the ordered phase (B2 and DO3) is also effectively suppressed. The decreased crystalline grain size and optimized microstructure morphology improved the plasticity and magnetic property. The Fe-6.5wt%Si steel strip at 42 m/s has a good phase composition of Fe (predominant), Fe2Si, and SiC. The sample showed an equiaxed ferrite crystal structure, and the saturation magnetizations were 302.5 and 356.6 emu/g in the parallel magnetic direction and the vertical magnetic direction, respectively. This phase transition behavior contributed to the exceptional magnetic property of the Fe-6.5wt%Si steel.

Recent progress in electrochemical performance of binder-free anodes for potassium-ion batteries.

Potassium ion batteries (PIBs) are regarded as one of the most promising candidates for large-scale stationary energy storage beyond lithium-ion batteries (LIBs), owing to the abundance of potassium resources and low cost. Unfortunately, the practical application of PIBs is severely restricted by their poor rate capacity and unsatisfactory cycle performance. In traditional electrodes, a binder usually plays an important role in integrating individual active materials with conductive additives. Nevertheless, binders are not only generally electrochemically inactive but also insulating, which is unfavorable for improving overall energy density and cycling stability. To this end, in terms of both improved electronic conductivity and electrochemical reaction reversibility, binder-free electrodes offer great potential for high-performance PIBs. Moreover, the anode is a crucial configuration to determine full cell electrochemical performance. Therefore, this review analyzes in detail the electrochemical properties of the different type binder-free anodes, including carbon-based substrates (graphene, carbon nanotubes, carbon nanofibers, and so on), MXene-based substrates and metal-based substrates (Cu and Ni). More importantly, the recent progress, critical issues, challenges, and perspectives in binder-free electrodes for PIBs are further discussed. This review will provide theoretical guidance for the synthesis of high-performance anode materials and promote the further development of PIBs.

Effects of 50-Hz magnetic field exposure on hormone secretion and apoptosis-related gene expression in human first trimester villous trophoblasts in vitro.

Evidence from epidemiological and animal studies showed that exposure to extremely low frequency magnetic fields (ELF-MF) could produce deleterious effects on reproduction. In order to investigate the possible mechanism of MF exposure on reproductive effects, first trimester human chorionic villi at 8-10 weeks' gestation were obtained, and trophoblasts were isolated, cultured, and exposed to a 50-Hz MF for different durations. The human chorionic gonadotropin (hCG) and progesterone in the culture medium was measured by electrochemiluminescence immunoassay. The mRNA levels of apoptosis-related genes bcl-2, bax, caspase-3, p53, and fas in trophoblasts were analyzed using real-time RT-PCR. The results showed that exposure of trophoblasts to MF at 0.2 mT for 72 h did not affect secretion of hCG and progesterone from these cells. There was also no significant change in secretion of these hormones when trophoblasts were exposed to a 0.4 mT MF for 48 h. However, MF significantly inhibited hCG and progesterone secretion of trophoblasts after exposure for 72 h at 0.4 mT. Results of apoptosis-related gene expression analysis showed that, within 72 h of exposure at 0.4 mT, there was no significant difference between MF exposure and control on the expression pattern of each gene. Based on results of the present experiment, it is suggested that exposure to MF for a longer duration (72 h) could inhibit secretion of hCG and progesterone by human first trimester villous trophoblasts, however, the effect might not be related to trophoblast apoptosis.

Mineral Transition and Chemical Reactivity Evolution of a Low-Lime Calcium Aluminate Clinker with MgO and Na2SO4 Codopants.

The mineral formation-transition mechanism, microstructure evolution, crystal structure, pulverization property, and chemical reactivity of the CaO-Al2O3-SiO2 clinker with MgO and Na2SO4 dopants during the sintering process at 1300 °C for 2.0 h were systematically studied using CaO, Al2O3, SiO2, MgO, and Na2SO4 as raw materials when the molar ratio of CaO to Al2O3 is 1.4, the mass ratio of Al2O3 to SiO2 is 3.0, and the mass percentage of MgO and Na2SO4 is 2%. The MgO dopant could result in 12CaO·7Al2O3 and γ-2CaO·SiO2, transform into 20CaO·13Al2O3·3MgO·3SiO2, restrain the crystal transformation of 2CaO·SiO2 from ß to γ, and then deteriorate the pulverization and alumina leaching property corresponding to parts of Al, Si, and Mg atoms occupying the same lattice positions of the crystal structure. MgO and Na2SO4 codoped could promote transformation of 20CaO·13Al2O3·3MgO·3SiO2 into 3CaO·3Al2O3·CaSO4 as well as some 2CaO·Al2O3·SiO2, while 3CaO·3Al2O3·CaSO4 has good alumina leaching property in the Na2CO3-NaOH solution. The ultrasonic assistant mainly could promote the diffusion of reactive samples, enhance the separation of agglomeration, and then accelerate the chemical reaction of the sintered clinker with Na2CO3-NaOH.

[Noise magnetic fields mitigates the inhibition of secretion function of primary human villous trophoblasts induced by 50 Hz magnetic fields].

OBJECTIVE: To explore the effects of 50 Hz sinusoidal magnetic fields (MF) on secretion function of primary human villous trophoblasts in vitro, and the interference effect of "noise" MF. METHODS: The trophoblasts were isolated from human villus by trypsin digestion and incubated in DMEM medium.Then the trophoblasts were exposed to 0.4 mT 50 Hz MF and/or "noise" MF respectively for different durations. Each exposure group was matched with one control group which was from the same villus and cultured with the same condition except the MF exposure. The concentrations of human chorionic gonadotropin (HCG) and progesterone in the culture medium were measured by immunofluorescence. Statistical significance of differences between means was determined by one way-ANOVA with P<0.05 considered significant. RESULT: 50 Hz MF inhibited the HCG and progesterone secretion significantly when exposure for 72 h (compared with control group, P<0.05). There was no significant change of HCG and progesterone secretion when trophoblasts were exposed to 0.4 mT "noise" MF within 72 h (compared with control group, P>0.05). However, by superimposing the "noise" MF, the inhibition of HCG and progesterone secretion of trophoblasts induced by 50 Hz MF was eliminated. CONCLUSION: The exposure to 50 Hz MF for long period could inhibit trophoblasts secreting HCG and progesterone, and the "noise" MF with the same intensity could eliminate the effects induced by 50 Hz MF.

[Effect of Tongxinluo superfine on experimental anginal model (contraction of collaterals) in rat with endothelial dysfunction].

OBJECTIVE: To study the effect of Tongxinluo superfine (TXL) on experimental anginal model induced by Arginine Vasopressin in rats with endothelial dysfunction. METHOD: First, the endothelial dysfunction rat model was made by methionine-induced hyperhomocysteinemia (HHcy). The thoracic aorta were excised, and acetylcholine (Ach)-induced endothelium dependent relaxation and sodium nitroprusside (SNP) induced endothelium-independent relaxation were measured. Total plasma homocysteine (Hcy) concentrations were measured with automated fluorescence polarization immunoassay (FPIA). Enzyme-linked immunosorbent assay (ELISA) was used to detect plasma von Willebrand factor (vWF) level. Plasma nitric oxide (NO) contents were assayed by method of nitrate reductase. Then, the rat model of collaterals contraction (model group) was established by AVP intravenous injection in rats with endothelial dysfunction and the S wave change (DeltaS) and T wave depression in Lead II ECG were used as the index of angina severity. The nitric oxide (NO) contents in serum and the expression of myocardium eNOS mRNA were measured. RESULT: Ach (0. 1-1000 nmol L(-1))-induced endothelium dependent relaxation (EDR) of aortic rings was significantly decreased in HHcy group. The endothelium-independent relaxation induced by SNP (0.001-10 micromol L(-1)) was not significantly different between the two groups. Plasma homocysteine concentrations and vWF levels in rats treated with methionine were higher than those of control group, while NO contents were significantly decreased in HHcy group compared with control. The results showed that L-methionine intake induced hyperhomocysteinemia in rats. Impaired EDR, increased vWF and decreased NO suggested the exist of endothelial dysfunction. DeltaS of model group increased from 1 min to 5 min and T wave of model group depressed at 2 min compared with that of control after the administration of vasopressin (0.5 U kg(-1)). The intragastric administration of TXL inhibited vasopressin-induced S wave change at 4 min and 5 min and T wave depression from 30 s to 3 min after AVP injection. The NO contents in serum and the expression of myocardium eNOS mRNA of TXL group were increased compared with model group. CONCLUSION: Experimental angina induced by AVP injection is more severe in rats with endothelial dysfunction. Tongxinluo Superfine can protect against collaterals contraction in rats maybe by increasing the NO contents in serum and the expression of myocardium eNOS mRNA.

[Apoptosis-related gene expression of human villous trophoblasts exposed to 50 Hz magnetic field].

OBJECTIVE: To study apoptosis-related gene expression of human villous trophoblasts exposed to 50 Hz magnetic field and to investigate the possible mechanism of human reproductive health effects caused by 50 Hz magnetic field. METHODS: Cultured human villous trophoblasts were exposed to 50 Hz magnetic field at 0.4 mT for 6, 48, 72 hours. Gene expressions of Bcl-2, Bax, Caspase-3, p53 and Fas were analyzed using real-time reverse transcription polymerase chain reaction (RT-PCR) assay. RESULTS: Within 72 hours, the average fold change for each gene was near 1.00, and there was no significant difference on expression pattern in each gene between exposure and control groups (P > 0.05). CONCLUSION: 0.4 mT 50 Hz magnetic field does not affect the apoptosis-related gene expression of human villous trophoblasts in vitro.

[Effects of 50 Hz magnetic fields exposure on secretion of primary human villous trophoblasts].

OBJECTIVE: To explore the possible effects of 50 Hz magnetic fields (MF) exposure on HCG and progesterone secretion of human villous trophoblasts in vitro. METHODS: The trophoblasts were isolated from human villus by trypsin digestion and incubated in DMEM medium. Then the trophoblasts were exposed to 0.2 mT, 0.4 mT 50 Hz MF for 6 h, 12 h, 24 h, 48 h and 72 h, respectively. Each exposure group was matched to one control group which was from the same villus and cultured with the same condition except the 50 Hz MF exposure. The concentration of human chorionic gonadotropin (HCG) and progesterone in the culture medium was detected by electrochemiluminescence immunoassay. Statistical significance of differences between means was determined by one way-ANOVA with P < 0.05 considered significant. RESULTS: Exposure of trophoblasts to 50 Hz MF at 0.2 mT intensity within 72 h did not affect the secretion level of HCG and progesterone (compared with blank control, P > 0.05). There was also no significant change of the secretion level of HCG and progesterone when trophoblasts were exposed to 0.4 mT 50 Hz MF within 48 h (compared with blank control, P > 0.05). However, 50 Hz MF inhibited the HCG and progesterone secretion significantly with exposure for 72 h (compared with blank control, P < 0.05). CONCLUSION: The exposure to 50 Hz MF for long period could inhibit trophoblasts excreting the HCG and progesterone, and the threshold intensity may be between 0.2 mT and 0.4 mT.