The mammary gland is a sensitive pubertal target in CD-1 and C57Bl/6 mice following perinatal perfluorooctanoic acid (PFOA) exposure

Perfluorooctanoic acid (PFOA) is a developmental toxicant in mice, with varied strain outcomes depending on dose and period of exposure. The impact of PFOA on female mouse pubertal development at low doses (≤1 mg/kg) has yet to be determined. Therefore, female offspring from CD-1 and C57Bl/6 dams exposed to PFOA, creating serum concentrations similar to humans, were examined for pubertal onset, including mammary gland development. Pups demonstrated a shorter PFOA elimination half-life than that reported for adult mice. Prenatal exposure to PFOA caused significant mammary developmental delays in female offspring in both strains. Delays started during puberty and persisted into young adulthood; severity was dose-dependent. Also an evaluation of female serum hormone levels and pubertal timing onset revealed no effects of PFOA compared to controls in either strain. These data suggest that the mammary gland is more sensitive to early low level PFOA exposures compared to other pubertal endpoints, regardless of strain.     

踝肱指数异常增高的糖尿病患者心血管病危险因素研究

目的分析踝肱指数(ABI)增高的糖尿病患者的心血管病危险因素。方法采用多普勒血流探测仪测定解放军第306医院2003—2005年门诊及病房收治的493例2型糖尿病患者的ABI,以ABI<0·90为低ABI组(n=39),0·90≤ABI≤1·40为正常组(n=353),ABI>1·40为高ABI组(n=101);同时对心血管病危险因素进行分析。结果高ABI与正常ABI组比较,腰围、腰臀比、C反应蛋白、尿酸显著增高,吸烟率及高血压合并症发生率显著增加。结论ABI>1·40的糖尿病患者有更多的动脉硬化危险因素,需要将这些患者与ABI<0·90的患者同样重视。     

A network analysis of two conceptual approaches to the etiology of PTSD

Two prominent conceptual models of posttraumatic stress disorder (PTSD) are the cognitive model, associated with cognitive processing therapy (CPT; Resick & Schnicke, 1992), and the functional contextualist model, underlying acceptance and commitment therapy (ACT; Hayes et al., 1999). Network analysis was used to examine dynamic interactions among cognitive (relating to CPT) and functional contextualistic (relating to ACT) variables and PTSD symptoms in a sample of 722 trauma-exposed adults. Results from the cognitive networks highlighted the importance of maladaptive beliefs about threat in maintaining the co-occurrence of PTSD symptoms and cognitive variables. Additionally, PTSD symptoms were more likely to lead to cognitive variables, rather than the reverse direction. Results from the functional contextualist networks identified numerous associations amongst variables that contribute to the co-occurrence of PTSD symptoms and psychological inflexibility. Findings from this study may help generate causal hypotheses that can be tested further using a longitudinal study design.     

Maternal insomnia during the COVID-19 pandemic: associations with depression and anxiety

Background

The COVID-19 outbreak has made people more prone to depression, anxiety and insomnia, and females are at a high risk of developing these conditions. As a special group, pregnant and lying-in women must pay close attention to their physical and mental health, as both have consequences for the mother and the fetus. However, knowledge regarding the status of depression, anxiety and insomnia among these women is limited.

Aim

This study aimed to examine insomnia and psychological factors among pregnant and lying-in women during the COVID-19 pandemic and provide theoretical support for intervention research.

Methods

In total, 2235 pregnant and lying-in women from 12 provinces in China were surveyed; their average age was 30.25 years (SD = 3.99, range = 19–47 years).

Participants and setting

The participants completed electronic questionnaires designed to collect demographic information and assess levels of depression, anxiety and insomnia.

Results

The prevalence of insomnia in the sample was 18.9%. Depression and anxiety were significant predictors of insomnia. Participants in high-risk areas, those with a disease history, those with economic losses due to the outbreak, and those in the postpartum period had significantly higher insomnia scores.

Discussion

The incidence of insomnia among pregnant and lying-in women is not serious in the context of the epidemic, which may be related to the sociocultural background and current epidemic situation in China.

Conclusion

Depression and anxiety are more indicative of insomnia than demographic variables.

     

Activity and bacterial diversity of snow around Russian Antarctic stations

The diversity and temporal dynamics of bacterial communities in pristine snow around two Russian Antarctic stations was investigated. Taxonomic analysis of rDNA libraries revealed that snow communities were dominated by bacteria from a small number of operational taxonomic units (OTUs) that underwent dramatic swings in abundance between the 54th (2008–2009) and 55th (2009–2010) Russian Antarctic expeditions. Moreover, analysis of the 55th expedition samples indicated that there was very little, if any, correspondence in abundance of clones belonging to the same OTU present in rDNA and rRNA libraries. The latter result suggests that most rDNA clones originate from bacteria that are not alive and/or active and may have been deposited on the snow surface from the atmosphere. In contrast, clones most abundant in rRNA libraries (mostly belonging to Variovorax, Janthinobacterium, Pseudomonas, and Sphingomonas genera) may be considered as endogenous Antarctic snow inhabitants.     

Intrinsic non-hub connectivity predicts human inter-temporal decision-making

Inter-temporal decision-making is ubiquitous in daily life and has been considered as a critical characteristic associated with an individual’s success. Such decisions require us to tradeoff between short-term and long-term benefits. Prior studies have indicated that inter-temporal decision involves various brain regions that tend to occupy the central hubs. However, it is unclear whether the functional connectivities among hub as well as non-hub regions can predict discounting behaviors. Here, we combined with graph-theoretical algorithm and multivariate pattern analysis to explore whether voxel-wise functional connectivity strength in the whole brain could predict discounting rates (indexed as logk, based on the adaptive delay-discounting task) in a relatively large sample (n = 429) of young adults. Results revealed that short- and long-distance as well as all-range non-hub functional connectivity strength in the limbic system (i.e., medial orbitofrontal cortex and parahippocampus) were inversely associated with discounting rates. Furthermore, these results were robust and did not appear to be due to potential confounding factors. Above weight-based degree metric is commonly indicative of the communication pattern of local and global parallel information processing, and it therefore provides novel insights into the neural mechanisms underlying inter-temporal decision-making from the perspective of human brain topological organizations.

     

Safety evaluation of a new setup for transcranial electric stimulation during magnetic resonance imaging

BackgroundTranscranial electric stimulation during MR imaging can introduce safety issues due to coupling of the RF field with the stimulation electrodes and leads.ObjectiveTo optimize the stimulation setup for MR current density imaging (MRCDI) and increase maximum stimulation current, a new low-conductivity (σ = 29.4 S/m) lead wire is designed and tested.MethodThe antenna effect was simulated to investigate the effect of lead conductivity. Subsequently, specific absorption rate (SAR) simulations for realistic lead configurations with low-conductivity leads and two electrode types were performed at 128 MHz and 298 MHz being the Larmor frequencies of protons at 3T and 7T. Temperature measurements were performed during MRI using high power deposition sequences to ensure that the electrodes comply with MRI temperature regulations.ResultsThe antenna effect was found for copper leads at ¼ RF wavelength and could be reliably eliminated using low-conductivity leads. Realistic lead configurations increased the head SAR and the local head SAR at the electrodes only minimally. The highest temperatures were measured on the rings of center-surround electrodes, while circular electrodes showed little heating. No temperature increase above the safety limit of 39 °C was observed.ConclusionCoupling to the RF field can be reliably prevented by low-conductivity leads, enabling cable paths optimal for MRCDI. Compared to commercial copper leads with safety resistors, the low-conductivity leads had lower total impedance, enabling the application of higher currents without changing stimulator design. Attention must be paid to electrode pads.     

工作记忆与发展性阅读障碍

发展性阅读障碍是学习障碍的一种类型。研究发现,发展性阅读障碍者常常在工作记忆任务中表现出缺陷。根据Baddeley的工作记忆模型,这些研究一般是围绕语音环、视-空画板以及中央执行器这三个方面来进行的,涵盖了行为和脑神经机制两个层面。近年来,一些研究者开始针对发展性阅读障碍进行工作记忆训练,这方面的研究也取得了一些成果。这些研究成果为揭示汉语发展性阅读障碍的内在机制以及开发相应的训练矫正程序提供了借鉴。