Investigating the temporal dynamics of electroencephalogram (EEG) microstates using recurrent neural networks

Electroencephalogram (EEG) microstates that represent quasi‐stable, global neuronal activity are considered as the building blocks of brain dynamics. Therefore, the analysis of microstate sequences is a promising approach to understand fast brain dynamics that underlie various mental processes. Recent studies suggest that EEG microstate sequences are non‐Markovian and nonstationary, highlighting the importance of the sequential flow of information between different brain states. These findings inspired us to model these sequences using Recurrent Neural Networks (RNNs) consisting of long‐short‐term‐memory (LSTM) units to capture the complex temporal dependencies. Using an LSTM‐based auto encoder framework and different encoding schemes, we modeled the microstate sequences at multiple time scales (200–2,000 ms) aiming to capture stably recurring microstate patterns within and across subjects. We show that RNNs can learn underlying microstate patterns with high accuracy and that the microstate trajectories are subject invariant at shorter time scales (≤400 ms) and reproducible across sessions. Significant drop in the reconstruction accuracy was observed for longer sequence lengths of 2,000 ms. These findings indirectly corroborate earlier studies which indicated that EEG microstate sequences exhibit long‐range dependencies with finite memory content. Furthermore, we find that the latent representations learned by the RNNs are sensitive to external stimulation such as stress while the conventional univariate microstate measures (e.g., occurrence, mean duration, etc.) fail to capture such changes in brain dynamics. While RNNs cannot be configured to identify the specific discriminating patterns, they have the potential for learning the underlying temporal dynamics and are sensitive to sequence aberrations characterized by changes in metal processes. Empowered with the macroscopic understanding of the temporal dynamics that extends beyond short‐term interactions, RNNs offer a reliable alternative for exploring system level brain dynamics using EEG microstate sequences.     

Concomitant cardiac and hepatic hemangiomas

Primary tumors of the heart are rare with a reported incidence of about 0.002% to 0.3% at autopsy. A cardiac hemangioma is a form of benign primary cardiac tumor that often presents with atypical clinical symptoms. Hemangiomas are generally isolated lesions. Here, we report a patient with previous hepatic hemangioma who later was found to have a large coexistent cardiac hemangioma presenting with cardiac compressive symptoms.     

Correction to: Acetyl-L-carnitine confers neuroprotection against lipopolysaccharide (LPS) -induced neuroinflammation by targeting TLR4/NFκB,autophagy, inflammation and oxidative stress

Metabolic Brain Disease - A Correction to this paper has been published: 10.1007/s11011-021-00721-8     

In vitro fracture resistance of endodontically-treated maxillary premolars

Many endodontically-treated teeth require quick, simple, low-cost restorations. This study evaluated the effect of horizontal pins and flowable composites on the fracture resistance of endodontically-treated maxillary premolars directly restored with resin composite. In this in vitro study, 64 intact human maxillary premolars, extracted for orthodontic reasons, were randomly divided into four groups of 16. Standard access cavities were prepared in such a way that the buccal cusp had a buccolingual thickness of 3 mm measured at the height of contour. The palatal cusp was reduced to 1.5 mm coronal to CEJ. The specimens were prepared as follows: Group 1: resin composite restoration without horizontal self-threading pins or flowable composite (control group). Group 2: resin composite restoration without horizontal self-threading pins but with a 2 mm thickness of the flowable composite. Group 3: resin composite restoration with two horizontal self-threading pins in the buccal cusp but without flowable composite. Group 4: resin composite restoration with two horizontal self-threading pins in the buccal cusp and flowable composite with a thickness of 2 mm. Subsequent to thermocycling, all specimens were loaded to failure. The data were analyzed using a two-factor ANOVA test (alpha = 0.05). The maximum mean of fracture resistance was in Group 1 (632.86 +/- 119.46 N), and the minimum value was related to Group 3 (533.49 +/- 168.07 N). There was not a statistically significant difference between the groups (p > 0.05). Conclusion: Neither horizontal pin placement nor flowable composite had a significant effect on increasing the fracture resistance of endodontically-treated maxillary premolars restored with composite.     

What we know about the purpose,theoretical foundation,scope and dimensionality of existing self-management measurement tools: A scoping review

Objectives

To identify self-report, self-management measures for adults with chronic conditions, and describe their purpose, theoretical foundation, dimensionality (multi versus uni), and scope (generic versus condition specific).

Cardioprotective effect of β-d-mannuronic acid (M2000) as a novel NSAID on gene expression of oxLDL scavenger receptors in the experimental diabetic model

Context: The investigations have shown that patients with diabetes have the elevated levels of glucose and oxLDL. These two play an important role in increased expression levels of oxLDL scavenger receptors on the surface of macrophages and endothelial cells that leads to deposition of oxLDL and macrophages in vascular walls.

Objective: The present study intends to show the effects of β-d-mannuronic acid (M2000) on the expression profile of ox-LDL scavenger receptors (including SR-A, LOX-1, CD36, and CD68) in an experimental model of diabetes.

Materials and methods: Eighteen Sprague-Dawley rats were randomly divided into three 6-member groups of the healthy control, diabetic control, and treated rats by M2000. Diabetes was induced in rats by intraperitoneal (IP) administration of 60?mg/kg streptozotocin. The treated rats were given daily intraperitoneal injections of M2000 with a dose of 25?mg/kg for 28 days and at the end of the 28th day, their aortas were removed. The qRT-PCR technique was then used to evaluate the expression levels of the proposed gene.

Results: The gene expression levels of the SR-A, LOX-1, CD36, and CD68 significantly declined in the diabetic group that received M2000 compared with untreated diabetic rats.

Conclusions: The M2000, as a novel NSAID is able to modify by lowering the gene expression levels of SR-A, LOX-1, CD36, and CD68 in treated rats compared to the untreated diabetic group, which may play an important role in preventing the complications that could lead to a cardioprotective efficacy.     

Oxidative Stress Responses to Nigella sativa Oil Concurrent with a Low‐Calorie Diet in Obese Women: A Randomized,Double‐Blind Controlled Clinical Trial

The aim of the present study was to determine the effects of Nigella sativa (NS) oil concurrent with a low‐calorie diet on lipid peroxidation and oxidative status in obese women. In this double‐blind placebo‐controlled randomized clinical trial, 50 volunteer obese (body mass index = 30–35 kg/m²) women aged 25–50 years old were recruited. Participants were randomly divided into intervention (n = 25) and placebo (n = 25) groups. They received a low‐calorie diet with 3 g/day NS oil or low‐calorie diet with 3 g/day placebo for 8 weeks. Forty‐nine women (intervention group = 25; placebo group = 24) completed the trial. NS oil concurrent with a low‐calorie diet decreased weight in the NS group compared to the placebo group (?4.80 ± 1.50 vs. ?1.40 ± 1.90 kg; p < 0.01). Comparison of red blood cell superoxidase dismutase (SOD) indicated significant changes in the NS group compared to the placebo group at the end of the study (88.98 ± 87.46 vs. ?3.30 ± 109.80 U/gHb; p < 0.01). But no significant changes in lipid peroxidation, glutathione peroxidase, and total antioxidant capacity concentrations were observed. NS oil concurrent with a low‐calorie diet decreased weight and increased SOD levels in obese women. However, more studies are suggested to confirm the positive effects of NS in obesity and its complications. Copyright © 2015 John Wiley & Sons, Ltd.