Effects of 50 Hz electromagnetic field on rat working memory and investigation of neural mechanisms / 生物医学工程学杂志

With the widespread use of electrical equipment, cognitive functions such as working memory (WM) could be severely affected when people are exposed to 50 Hz electromagnetic fields (EMF) for long term. However, the effects of EMF exposure on WM and its neural mechanism remain unclear. In the present paper, 15 rats were randomly assigned to three groups, and exposed to an EMF environment at 50 Hz and 2 mT for a different duration: 0 days (control group), 24 days (experimental group I), and 48 days (experimental group II). Then, their WM function was assessed by the T-maze task. Besides, their local field potential (LFP) in the media prefrontal cortex (mPFC) was recorded by the in vivo multichannel electrophysiological recording system to study the power spectral density (PSD) of θ and γ oscillations and the phase-amplitude coupling (PAC) intensity of θ-γ oscillations during the T-maze task. The results showed that the PSD of θ and γ oscillations decreased in experimental groups I and II, and the PAC intensity between θ and high-frequency γ (hγ) decreased significantly compared to the control group. The number of days needed to meet the task criterion was more in experimental groups I and II than that of control group. The results indicate that long-term exposure to EMF could impair WM function. The possible reason may be the impaired communication between different rhythmic oscillations caused by a decrease in θ-hγ PAC intensity. This paper demonstrates the negative effects of EMF on WM and reveals the potential neural mechanisms from the changes of PAC intensity, which provides important support for further investigation of the biological effects of EMF and its mechanisms.

Intra-abdominal aortic balloon occlusion in the management of placenta percreta / 中华医学杂志(英文版)

BACKGROUND@#Massive bleeding is the main concern for the management of placenta percreta (PP). Intra-abdominal aortic balloon occlusion (IABO) is one method for pelvic devascularization, but the efficacy of IABO is uncertain. This study aims to investigate the outcomes of IABO in PP patients.@*METHODS@#We retrospectively reviewed the clinical data of PP cases from six tertiary centers in China between January 2011 and December 2015. PP cases with/without the use of IABO were analyzed. Propensity score matching analysis was performed to reduce the effect of selection bias. Postpartum hemorrhage (PPH) and the rate of hysterectomy, as well as neonatal outcomes, were analyzed.@*RESULTS@#One hundred and thirty-two matched pairs of patients were included in the final analysis. Compared with the control group, maternal outcomes, including PPH (68.9% vs. 87.9%, χ2 = 13.984, P < 0.001), hysterectomy (8.3% vs. 65.2%, χ2 = 91.672, P < 0.001), and repeated surgery (1.5% vs. 12.1%, χ2 = 11.686, P = 0.001) were significantly reduced in the IABO group. For neonatal outcomes, Apgar scores at 1 minute (8.67 ± 1.79 vs. 8.53 ± 1.68, t = -0.638, P = 0.947) and 5 minutes (9.43 ± 1.55 vs. 9.53 ± 1.26, t = 0.566, P = 0.293) were not significantly different between the two groups.@*CONCLUSIONS@#IABO can significantly reduce blood loss, hysterectomies, and repeated surgeries. This procedure has not shown harmful effects on neonatal outcomes.

Effect of placenta previa attached to cesarean scar for adverse pregnant outcomes in patients with placenta accreta spectrum disorders / 中华妇产科杂志

Objective:To investigate the effect of placenta previa attached to cesarean scar for adverse pregnant outcomes in patients with or without placenta accreta spectrum disorders (PAS).Methods:The clinical information of patients with cesarean section history and placenta previa during the perioperative period at Peking University First Hospital from January 1st, 2015 to December 31st, 2020 were collected retrospectively. There were 53 cases without PAS and 172 cases with PAS, 153 cases with abnormally invasive placenta (containing placenta increta and placenta percreta) and 72 cases without PAS or with placenta accreta. The pregnant outcomes including rate of postpartum hemorrhage, transfusion, hysterectomy between the above groups were compared. Multivariate analysis was performed to study the factors significantly associated with PAS.Results:Pregnant women with PAS were at higher risk of adverse pregnant outcomes than those without PAS. Patients with PAS had higher incidences of hysterectomy [12.2% (21/172) vs 0(0/53); P=0.005], postpartum hemorrhage [60.5% (104/172) vs 5.7% (3/53); P<0.01] and blood transfusion [66.9% (115/172) vs 7.5% (4/53); P<0.01]. In the subgroup analysis stratified by the type of PAS, patients with abnormally invasive placenta were at higher risk of hysterectomy [13.7% (21/153) vs 0 (0/72); P<0.01], postpartum hemorrhage [66.7% (102/153) vs 6.9% (5/72); χ2 =70.873, P<0.01] and blood transfusion [74.5% (114/153) vs 6.9% (5/72); χ2 =90.869, P<0.01]. After multiple logistic regression, the type of creta had the positive relation with postpartum hemorrhage ( OR=27.622, 95% CI:9.873~77.280; P<0.01) and blood transfusion ( OR=36.912, 95% CI:13.239~102.922; P<0.01). There were no significant correlations between adverse pregnant outcomes and the type of placenta previa or the times of cesarean section (all P>0.01). Conclusions:Placenta previa attached to cesarean scar without PAS or with placenta accreta could not act as the factor of predicting adverse pregnant outcomes in clinic. Placenta previa attached to cesarean scar with placenta increta or placenta percreta could increase the risk of adverse pregnant outcomes.