Exploring the Enhancement of Exchange Bias in Innovative Core/Shell/Shell Structures: Synthesis and Magnetic Properties of Co-Oxide/Co and Co-Oxide/Co/Co-Oxide Inverted Nanostructures.

In this study, we investigate the enhancement of exchange bias in core/shell/shell structures by synthesizing single inverted core/shell (Co-oxide/Co) and core/shell/shell (Co-oxide/Co/Co-oxide) nanostructures through a two-step reduction and oxidation method. We evaluate the magnetic properties of the structures and study the effect of shell thickness on the exchange bias by synthesizing various shell thicknesses of Co-oxide/Co/Co-oxide nanostructures. The extra exchange coupling formed at the shell-shell interface in the core/shell/shell structure leads to a remarkable increase in the coercivity and the strength of the exchange bias by three and four orders, respectively. The strongest exchange bias is achieved for the sample comprising the thinnest outer Co-oxide shell. Despite the general declining trend of the exchange bias with Co-oxide shell thickness, we also observe a nonmonotonic behavior in which the exchange bias oscillates slightly as the shell thickness increases. This phenomenon is ascribed to the dependence of the antiferromagnetic outer shell thickness variation at the expense of the simultaneous opposite variation in the ferromagnetic inner shell.

DNA aerogels and DNA-wrapped CNT aerogels for neuromorphic applications.

Nucleic acids are programmable materials that can self-assemble into defined or stochastic three-dimensional network architectures. Various attributes of self-assembled, cross-linked Deoxyribonucleic acid (DNA) hydrogels have recently been investigated, including their mechanical properties and potential biomedical functions. Herein, for the first time, we describe the successful construction of pure DNA aerogels and DNA-wrapped carbon nanotube (CNT) composite (DNA-CNT) aerogels via a single-step freeze-drying of the respective hydrogels. These aerogels reveal highly porous and randomly branched structures with low density. The electrical properties of pure DNA aerogel mimic that of a simple capacitor; in contrast, the DNA-CNT aerogel displays a fascinating resistive switching behavior in response to an applied bias voltage sweep reminiscent of a volatile memristor. We believe these novel aerogels can serve as a platform for developing complex biomimetic devices for a wide range of applications, including real-time computation, neuromorphic computing, biochemical sensing, and biodegradable functional implants. More importantly, insight obtained here on self-assembling DNA to create aerogels will pave the way to construct novel aerogel-based material platforms from DNA coated or wrapped functional entities.

Hypoxia-inducible factor 1 alpha (HIF-1α) stimulated and P2X7 receptor activated by COVID-19, as a potential therapeutic target and risk factor for epilepsy.

Based on available evidence, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a neuroinvasive virus. According to the centers for disease control and prevention (CDC), coronavirus disease 2019 (COVID-19) may cause epilepsy. In this line, COVID-19 can stimulate hypoxia-inducible factor-1 alpha (HIF-1α) and activate P2X7 receptor. Both HIF-1α and P2X7 receptors are linked to epileptogenesis and seizures. Therefore, in the current study, we suggested that COVID-19 may have a role in epileptogenesis and seizure through HIF-1α stimulation and P2X7 receptor activation. Consequently, pharmacological targeting of these factors could be a promising therapeutic approach for such patients.

Engineered hyaluronic acid-decorated niosomal nanoparticles for controlled and targeted delivery of epirubicin to treat breast cancer.

Targeted drug delivery systems using nanocarriers offer a versatile platform for breast cancer treatment; however, a robust, CD44-targeted niosomal formulation has not been developed and deeply studied (both in vitro and in vivo) yet. Here, an optimized system of epirubicin (Epi)-loaded niosomal nanoparticles (Nio) coated with hyaluronic acid (HA) has been engineered for targeting breast cancer cells. The nanoformulation was first optimized (based on size, polydispersity index, and entrapment efficiency); then, we characterized the morphology, stability, and release behavior of the nanoparticles. Epirubicin release from the HA-coated system (Epi-Nio-HA) showed a 21% (acidic buffer) and 20% (neutral buffer) reduction in comparison with the non-coated group (Epi-Nio). The cytotoxicity and apoptosis results of 4T1 and SkBr3 cells showed an approximately 2-fold increase in the Epi-Nio-HA system over Epi-Nio and free epirubicin, which confirms the superiority of the engineered nanocarriers. Moreover, real-time PCR data demonstrated the down-regulation of the MMP-2, MMP-9, cyclin D, and cyclin E genes expression while caspase-3 and caspase-9 gene expression were up-regulated. Confocal microscopy and flow cytometry studies uncovered the cellular uptake mechanism of the Epi-Nio-HA system, which was CD44-mediated. Furthermore, in vivo studies indicated Epi-Nio-HA decreased mice breast tumor volume by 28% (compared to epirubicin) without side effects on the liver and kidney. Conclusively, our results indicated that the HA-functionalized niosomes provide a promising nanoplatform for efficient and targeted delivery of epirubicin to potentially treat breast cancer.

Modeling and characterization of stochastic resistive switching in single Ag2S nanowires.

Chalcogenide resistive switches (RS), such as Ag2S, change resistance due to the growth of metallic filaments between electrodes along the electric field gradient. Therefore, they are candidates for neuromorphic and volatile memory applications. This work analyzed the RS of individual Ag2S nanowires (NWs) and extended the basic RS model to reproduce experimental observations. The work models resistivity of the device as a percolation of the conductive filaments. It also addressed continuous fluctuations of the resistivity with a stochastic change in volume fractions of the filaments in the device. As a result, these fluctuations cause unpredictable patterns in current-voltage characteristics and include a spontaneous change in resistance of the device during the linear sweep that conventional memristor models with constant resistivity cannot represent. The parameters of the presented stochastic model of a single Ag2S NW were fitted to the experimental data and reproduced key features of RS in the physical devices. Moreover, the model suggested a non-core shell structure of the Ag2S NWs. The outcome of this work is aimed to aid in simulating large self-assembled memristive networks and help to extend existing RS models.

The influence of the female reproductive tract and sperm features on the design of microfluidic sperm-sorting devices.

Although medical advancements have successfully helped a lot of couples with their infertility by assisted reproductive technologies (ART), sperm selection, a crucial stage in ART, has remained challenging. Therefore, we aimed to investigate novel sperm separation methods, specifically microfluidic systems, as they do sperm selection based on sperm and/or the female reproductive tract (FRT) features without inflicting any damage to the selected sperm during the process. In this review, after an exhaustive studying of FRT features, which can implement by microfluidics devices, the focus was centered on sperm selection and investigation devices. During this study, we tried not to only point to the deficiencies of these systems, but to put forth suggestions for their improvement as well.

The effect of interval training on adipokine plasmatic levels in rats with induced myocardial infarction.

Context: Exercise has been demonstrated to reduce pro-inflammatory while boosting anti-inflammatory adipokines; yet research in relation to Myocardial infarction (MI) is limited.Objective: The aim of this study was to investigate the effect of an interval exercise-training programme on concentrations of Lipocalin-2 and Adiponectin plasmatic levels in rats with induced MI.Materials and methods: The experimental study design comprised of three groups, including: a control group, MI control group and MI training group that participated in an interval training protocol for six weeks.Results: There was a significant increase in Lipocalin-2 levels in the MI interval training group when compared to the other groups.Discussion and conclusion: Although interval training has beneficial effects on adiponectin, it also increases Lipocalin-2 concentrations. Because Lipocalin-2 significantly contributes to the pathogenesis of atherosclerosis and adverse cardiac conditions, our findings suggest that interval training might be a counterproductive strategy to improve MI-related cardiac damage.

Enhancement of Diffusion, Densification and Solid-State Reactions in Dielectric Materials Due to Interfacial Interaction of Microwave Radiation: Theory and Experiment.

A detailed theoretical model and experimental study are presented that formulate and prove the existence of a robust ponderomotive force (PMF) near the interfaces in a granular dielectric material under microwave radiation. The model calculations show that the net direction of the PMF is pore angle-dependent. For most of the pore angles, the net force is towards the interface creating a mass transport that fills the interfacial pores and facilitates densification. For small ranges of angles, near 180o and 360o, PMF drives the ions in the reverse direction and depletes the pores. However, the net force for such ranges of angles is small. The PMF also enhances the diffusion of the mobile ionic species and, consequently, accelerates the solid-state reaction by increasing the collision probability. The proof-of-concept experiments show that a mixture of elemental powders can diffuse, react, and form dense materials when radiated by the microwave in just a few minutes. Such characteristics, together with field-induced decrystallization, offer a novel and simple approach for the synthesis of nanostructured compounds, which can have practical implications in ceramic technologies and thermoelectric materials.

Endoplasmic Reticulum Stress (ER Stress) and Unfolded Protein Response (UPR) Occur in a Rat Varicocele Testis Model.

Using a surgically induced varicocele rat model, we show here strong evidence that the misfolded/unfolded protein response that is part of the stress response of the endoplasmic reticulum (ER) is activated in the varicocele testis (VCL), leading to the induction of apoptosis. To support this hypothesis, it is observed that the spliced variant of the X-box protein 1 (XBP1s), resulting from the activation of the inositol-requiring enzyme 1 (IRE1) membrane sensor, is significantly more represented in VCL testicular extracts. The activation of the IRE1/XBP1s pathway is also supported by the observation that the VCL testes show an increase phosphorylation of the c-Jun-kinase (JNK) known to be one intermediate of this pathway and an increased level of caspase-3, the terminal apoptotic effector, partly explaining the apoptotic status of the VCL testis.

Capsaicin improves sperm quality in rats with experimental varicocele.

Capsaicin is the main capsaicinoid in chilli peppers that have numerous biological and pharmaceutical roles in the body such as antioxidant, anti-inflammatory, anticarcinogenic, analgesic, counterirritant and antiarthritic properties. Numerous studies have shown increased oxidative stress in men with varicocele that is caused by dilation of the spermatic vein and increase of testicular temperature. Therefore, we aimed to assess the effect of Capsaicin on sperm parameters in rats with experimental varicocele. At first, we induced varicocele in 30 Wistar rats and, verify varicocele model only in 10 rats by assessment of sperm parameters, oxidative stress, DNA damage and persistent histone after 2 months. Of the remaining 20 varicocelised rats, half of them were treated with 2.5 mg/kg Capsaicin for two months and the other half served as control. Then, sperm tests were assessed, and the results showed that Capsaicin can restore the mean of sperm oxidative stress (38.78 ± 3.75 versus 58.37 ± 4.34; p < .05), sperm concentration (60.14 ± 7.66 versus 34.87 ± 5.78; p < .05) and motility (62.43 ± 3.10 versus 41.22 ± 5.11; p < .05) in varicocelised rats treated with Capsaicin compared to varicocelised rats that were not treat. Therefore, Capsaicin possibly with reduction of oxidative stress level could improve mean of sperm concentration and motility in varicocele condition.

Effect of Training with or without Ziziphus Jujuba Extract on Cardiokines in Heart Tissue of Myocardial Infarcted Rats.

BACKGROUND: Today, the importance of physical activity as a preventative way for cardiovascular disease has attracted much attention.The aim of this study is to investigate the effect of 6 weeks of interval training with or without extract of Ziziphus jujuba on lipocalcin-2 (LCN2) and adiponectin levels in heart tissue in male Wistar rats with myocardial infarction. METHODS: Thirty male Wistar rats (mean weight, 180-220 g and age, 2-3 months) were divided into five groups, including (1) Healthy control; (2) Isoprenaline-treated group (ISO); (3) ISO + jujube extracts (JE); (4) Trained ISO rats; and (5) Trained ISO rats + JE. Exercise was performed (5 days/week, for 6 week including 54-min cycles with speed of 23 m/min and 54-min cycles with speed of 15 m/min). After 48 h of the last training session, the rats were sacrificed, and their heart tissue was excised. The significant level of statistical data was analyzed by one-way ANOVA test. RESULTS: LCN2 levels significantly decreased in trained ISO rats + JE group after 6 weeks of interval training with JE consumption, compared to ISO group. However, the consumption of jujuba extracts with and without interval training did not show any significant changes in adiponectin levels of rat's heart tissue, compared to ISO (P < 0.05). CONCLUSIONS: Because the LCN2 inflammatory factor decreased after 6 weeks of exercise and consumption of the extract, it seems that performing interval training with JE consumption can be an effective method in the cardiac rehabilitation phase after a heart attack.

The contribution of S100B to the glioprotective effects of valproic and arundic acids.

OBJECTIVES: Valproic and arundic acids are astrocytes-modulating agents with potential effects in the treatment of Alzheimer's disease (AD). S100B is an astrocytic cytokine with a possible role in the pathogenesis of AD. In this study, we aimed to assess the glioprotective effects of valproic and arundic acids against amyloid-ß-peptide (Aß)-induced glial death and contribution of S100B to the glioprotective effects of these agents in an astrocytic culture. MATERIALS AND METHODS: We used Aß25-35 at a concentration of 200 µM in 1321N1 astrocyte cells. We treated the cells with valproic acid (0.5 and 1 mM) and/or arundic acid 50 µM for 24 hr. Methylthiazolyldiphenyl-tetrazolium bromide (MTT) test was used to measure cell viability. The intracellular and extracellular S100B levels were measured using an ELISA kit. The data were analyzed using one-way analysis of variance followed by the Tukey's test. RESULTS: Aß (200 µM) decreased the cell viability compared to the control group (P<0.001). Valproic acid (0.5 and 1 mM) and arundic acid (50 µM) ameliorated the gliotoxic effects of Aß (P<0.05). The Aß-treated group had higher S100B levels (both intracellular and extracellular) compared to the negative control groups (P<0.001). Arundic and valproic acids (0.5 and 1 mM) decreased both the intracellular and extracellular S100B levels compared to the Aß-treated group (P<0.001). CONCLUSION: By considering homeostatic and neuroprotective functions of astrocyte, the astroprotective effects and the attenuation of S100B level may be responsible, at least in part, for the beneficial effects of valproic and arundic acids in AD.