Exploring the synchronization of cortical networks via entrainment to intrinsic frequencies.

Introduction: Transcranial electrical stimulation (tES), including transcranial alternating current stimulation (tACS) and transcranial direct current stimulation (tDCS), is widely studied for its potential to modulate brain oscillations and connectivity, offering treatment options for neurological disorders like Alzheimer's, Parkinson's, and insomnia. In this study, we focus on investigating the efficacy of tACS and tDCS in entraining intrinsic cortical network oscillations through a computational model.

Materials And Methods: We developed a 2D computational cortical neuron model with 2000 neurons (1600 pyramidal and 400 inhibitory), based on the Izhikevich neuron model.

Investigating the Effects of Transcranial Alternating Current Stimulation on Cortical Oscillations and Network Dynamics.

Transcranial electrical brain stimulation techniques like transcranial direct current (tDCS) and transcranial alternating current (tACS) have emerged as potential tools for treating neurological diseases by modulating cortical excitability. These techniques deliver small electric currents to the brain non-invasively through electrodes on the scalp. tDCS uses constant direct current which weakly alters the membrane voltage of cortical neurons, while tACS utilizes alternating current to target and enhance cortical oscillations, though the underlying mechanisms are not fully understood more specifically.

Loss of PTEN-Induced Kinase 1 Regulates Oncogenic Ras-Driven Tumor Growth By Inhibiting Mitochondrial Fission.

Mitochondrial metabolism and dynamics (fission and fusion) critically regulate cell survival and proliferation, and abnormalities in these pathways are implicated in both neurodegenerative disorders and cancer. Mitochondrial fission is necessary for the growth of mutant Ras-dependent tumors. Here, we investigated whether loss of PTEN-induced kinase 1 (PINK1) - a mitochondrial kinase linked to recessive familial Parkinsonism - affects the growth of oncogenic Ras-induced tumor growth and .

PINK1 deficiency is associated with increased deficits of adult hippocampal neurogenesis and lowers the threshold for stress-induced depression in mice.

Parkinson's disease (PD) is characterized by motor impairments and several non-motor features, including frequent depression and anxiety. Stress-induced deficits of adult hippocampal neurogenesis (AHN) have been linked with abnormal affective behavior in animals. It has been speculated that AHN defects may contribute to affective symptoms in PD, but this hypothesis remains insufficiently tested in animal models.

Lack of PINK1 alters glia innate immune responses and enhances inflammation-induced, nitric oxide-mediated neuron death.

Neuroinflammation is involved in the pathogenesis of Parkinson's disease (PD) and other neurodegenerative disorders. We show that lack of PINK1- a mitochondrial kinase linked to recessive familial PD - leads to glia type-specific abnormalities of innate immunity. PINK1 loss enhances LPS/IFN-γ stimulated pro-inflammatory phenotypes of mixed astrocytes/microglia (increased iNOS, nitric oxide and COX-2, reduced IL-10) and pure astrocytes (increased iNOS, nitric oxide, TNF-α and IL-1β), while attenuating expression of both pro-inflammatory (TNF-α, IL-1β) and anti-inflammatory (IL-10) cytokines in microglia.

Loss of PINK1 leads to metabolic deficits in adult neural stem cells and impedes differentiation of newborn neurons in the mouse hippocampus.

Emerging evidence suggests that mitochondrial dynamics regulates adult hippocampal neurogenesis (AHN). Although abnormal AHN has been linked to depression, anxiety, and cognitive dysfunction, which are features of neurodegenerative conditions, including Parkinson's disease (PD), the impact of mitochondrial deficits on AHN have not been explored previously in a model of neurodegeneration. Here, we used PTEN-induced kinase 1-deficient ( ) mice that lacked a mitochondrial kinase mutated in recessive familial PD.

Brain most susceptible to cadmium induced oxidative stress in mice.

Accumulated evidence over the years indicate that cadmium (Cd) may be a possible etiological factor for neurodegenerative diseases. This may possibly be linked to excessive generation of free radicals that damages the organs in the body depending on their defence mechanism. Since Cd is a toxic agent that affect several cell types, the aim of this study was to shed light on the effect of Cd and its consequences on different organs of the mice body.

A molecular simulation study of propane and propylene adsorption onto single-walled carbon nanotube bundles.

We have carried out configurational-bias Grand Canonical Monte Carlo simulations of propane and propylene adsorption onto homogeneous bundles of single-walled carbon nanotubes, at ambient temperature (T = 298.15 K) and over a pressure range of 0.1 bar < or = p < 10.

Aging of nanocarbons in ambient conditions: probable metastability of carbon nanotubes.

We studied the physicochemical properties of several commercially available single- and multi-walled carbon nanotubes (SWNTs and MWNTs) and fullerenes stored in normal ambient conditions for 24 months. We found that SWNTs exhibit a trend of decreasing surface area and pore volume up to 7-15 months but then stabilized, no longer being impacted by sample age or outgassing temperatures. Using X-ray Photoelectron Spectroscopy, we also observed a trend of decreasing surface oxygen in all samples from the beginning with much lower % oxygen observed after 12-15 months of aging under ambient conditions.

Application of water-activated carbon isotherm models to water adsorption isotherms of single-walled carbon nanotubes.

The objective of this study is to understand the interactions of water with novel nanocarbons by implementing semiempirical models that were developed to interpret adsorption isotherms of water in common carbonaceous adsorbents. Water adsorption isotherms were gravimetrically determined on several single-walled carbon nanotube (SWNT) and activated carbon samples. Each isotherm was fitted to the Dubinin-Serpinsky (DS) equation, the Dubinin-Astakov equation, the cooperative multimolecular sorption theory, and the Do and Do equations.

Regioselective competitive adsorption of water and organic vapor mixtures on pristine single-walled carbon nanotube bundles.

Sequential adsorption of water and organic vapor mixtures onto single-walled carbon nanotube (SWNT) bundles is studied experimentally and by grand canonical Monte Carlo (GCMC) simulation to elucidate the distinct interactions between select adsorbates and the nanoporous structure of SWNTs. Experimental adsorption isotherms on SWNT bundles for hexane, methyl ethyl ketone, cyclohexane, and toluene individually mixed in carrier gases that were nearly saturated with water vapor are compared with the GCMC-simulated isotherms for hexane, as a representative organic, on the external surface of the heterogeneous SWNT bundles. From the nearly perfect overlap between the experimental and simulated isotherms, it is concluded that until near saturation only the internal pore volume of pristine SWNT bundles fills with water.

Theoretical and experimental investigation of morphology and temperature effects on adsorption of organic vapors in single-walled carbon nanotubes.

Hexane adsorption on single-walled carbon nanotube (SWNT) bundles is studied by both simulation and experimentally using a previously developed computer-aided methodology, which employed a smaller physisorbed probe molecule, nitrogen, to explore the porosity of nanotube samples. Configurational-bias grand canonical Monte Carlo simulation of hexane adsorption on localized sites of the bundles is carried out to predict adsorption on their external surface and in their internal sites. These localized isotherms are then combined into a global isotherm for a given sample by using knowledge of its tube-diameter distribution and structural parameters, such as the fraction of open-ended nanotubes and the external surface area of bundles in samples, which have been independently determined from the standard nitrogen adsorption isotherm.

Structural characterization of single-walled carbon nanotube bundles by experiment and molecular simulation.

A procedure, combining molecular simulation, Raman spectroscopy, and standard nitrogen adsorption, is developed for structural characterization of single-walled carbon nanotube (SWNT) samples. Grand canonical Monte Carlo simulations of nitrogen adsorption are performed on the external and internal adsorption sites of homogeneous arrays of SWNTs of diameters previously determined by Raman spectroscopy of the sample. The results show the importance of the peripheral grooves of a nanotube bundle at low relative pressure and the insensitivity of nanotube diameter toward adsorption on the external surface of the bundle at higher pressures.