1,299 research outputs found

    mTOR-related cell-clearing systems in epileptic seizures, an update

    Get PDF
    Recent evidence suggests that autophagy impairment is implicated in the epileptogenic mechanisms downstream of mTOR hyperactivation. This holds true for a variety of genetic and acquired epileptic syndromes besides malformations of cortical development which are classically known as mTORopathies. Autophagy suppression is sufficient to induce epilepsy in experimental models, while rescuing autophagy prevents epileptogenesis, improves behavioral alterations, and provides neuroprotection in seizure-induced neuronal damage. The implication of autophagy in epileptogenesis and maturation phenomena related to seizure activity is supported by evidence indicating that autophagy is involved in the molecular mechanisms which are implicated in epilepsy. In general, mTOR-dependent autophagy regulates the proliferation and migration of inter-/neuronal cortical progenitors, synapse development, vesicular release, synaptic plasticity, and importantly, synaptic clustering of GABAA receptors and subsequent excitatory/inhibitory balance in the brain. Similar to autophagy, the ubiquitin–proteasome system is regulated downstream of mTOR, and it is implicated in epileptogenesis. Thus, mTOR-dependent cell-clearing systems are now taking center stage in the field of epilepsy. In the present review, we discuss such evidence in a variety of seizure-related disorders and models. This is expected to provide a deeper insight into the molecular mechanisms underlying seizure activit

    Potential antidepressant effects of scutellaria baicalensis, hericium erinaceus and rhodiola rosea

    Get PDF
    Recent studies focused on the pharmacology and feasibility of herbal compounds as a potential strategy to target a variety of human diseases ranging from metabolic to brain disorders. Accordingly, bioactive ingredients which are found within a variety of herbal compounds are reported to produce both neuroprotective and psychotropic activities which may help to combat mental disorders such as depression, anxiety, sleep disturbances and cognitive alterations. In the present manuscript, we focus on three herbs which appear effective in mitigating anxiety or depression with favourable risk-benefit profiles, namely Scutellaria baicalensis (S. baicalensis), Hericium erinaceus (H. erinaceus) and Rhodiola rosea (R. rosea). These three traditional folk medicinal herbs target the main biochemical events that are implicated in mental disorders, mimicking, to some extent, the mechanisms of action of conventional antidepressants and mood stabilizers with a wide margin of tolerability. In detail, they rescue alterations in neurotransmitter and neuro-endocrine systems, stimulate neurogenesis and the synthesis of neurotrophic factors, and they counteract oxidative stress, mitochondrial dysfunction and inflammation. Albeit the encouraging results that emerge from both experimental and clinical evidence, further studies are needed to confirm and better understand the mental-health promoting, and specifically, the antidepressant effects of these herbs

    Is “Unconsummated Marriage” still an appropriate term? A snapshot of reality

    Get PDF
    The most shared definition of Unconsummated Marriage (UM) refers to “the failure to perform successful sexual intercourse at the beginning of the marriage. UM usually occurs in the first few nights of marriage and so it is frequently referred to as “honeymoon impotence” or “wedding night impotence”. In the Middle-Eastern (MES) and Western (WS) societies, sexuality follows different patterns in terms of meaning and rules. Moreover the evolution of societies all around the world created new contexts and kinds of relationship. This could hamper a correct taxonomy of such sexual dysfunction where a social variable seems crucial. Aim: To analyze and review data on UM all around the world, to understand if in different societies it refers to the same situation. Method: A review of published literature on UM from 1970 to date, was conducted. Results: Substantial difference emerged from MES to WS. In MES, sexuality is allowable only in marriage, while in WS sexuality and relationship are not strongly linked. This could suggest that the term “marriage” is unable to cover the phenomenon in such different countries. Moreover, the average time before the consultation, causal attribution and prevalence are very different in Western and Middle Eastern countries. Conclusion: We found that the term “first attempts dysfunction” could be better used to describe male, female or both difficulties related to ignorance about sexuality or state/performance anxiety. On the other hand over the individual category of sexual dysfunctions, we suggest a new term as “Unconsummated relationship”, where individual difficulties toward sexuality are involved creating a couple’s dysfunction. Keywords: Unconsummated marriage; Honeymoon impotence; White marriage; Vaginismus; Infertilit

    Probing magnetism in magneto-electric multiferroics using circularly polarized x-rays

    Get PDF
    Multiferroic materials (in which electric and magnetic order coexist) that also display magneto-electric coupling have recently raised considerable interest as candidate compounds for advanced applications in electronics and data storage. In particular, the magneto-electric coupling is relevant in those materials such as TbMnO3 and Ni3V2O8 in which the onset of a cycloidal magnetic order drives the formation of a ferroelectric state. A key feature in these compounds is the possibility to control the population of magnetic domains (de�fined by the handedness of the cycloids) by an in situ electric fi�eld. The combination of magnetic non-resonant di�ffraction by circularly polarised X-rays with the full linear polarimetry of the scattered beam opens the way to a new class of experiments, in which the magnetic order of complex magnetic materials under applied electric and magnetic �fields is probed. This technique brings a strong experimental sensitivity to the imbalance in the domain populations, since the handedness of the circular polarisation naturally couples to the sense of rotation of the magnetic moments, leading to an accurate description of the domain state and to the re�finement of the magnetic structure. The results shed more light on the complex magnetic structure of TbMnO3, a challenging test case due to its two magnetic sublattices on the Mn and Tb sites, by identifying components of the ordering on the Tb sublattice and phase shifts that earlier neutron di�ffraction experiments could not resolve. In the case of Ni3V2O8, the method not only facilitated the refi�nement of the magnetic structure, but also allowed real space images of the magnetic cycloidal domains to be obtained. Their evolution is followed as they are controlled via magneto-electric coupling by the applied electric fi�eld and cycled through a hysteresis loop, thus collecting valuable information on domain formation, inhomogeneities and domain wall movement

    Microstructural, texture, plastic anisotropy and superplasticity development of ZK60 alloy during equal channel angular extrusion processing

    Get PDF
    In this study, equal channel angular pressing (ECAP) was exploited to refine the grain size of a ZK60 magnesium alloy in multi-processing steps, namely at temperatures of 250˚C, 200˚C and 150˚C, producing an ultrafine-grained (UFG) structure. The microstructural development and texture evolution during ECAP were systemically investigated by electron backscattered diffraction (EBSD) analysis. The microstructure of the ECAP processed alloy was remarkably refined to an average grain size of 600 nm. During ECAP process the original fiber texture of the as-extruded alloy was gradually weakened and eventually replaced by a stronger texture component coinciding with ECAP shear plane. The ECAP processed material showed a proper balance of tensile as well as compression strength and tensile ductility at room temperature. Yield strength of 273 and 253 MPa in tension and compression, respectively, ultimate tensile strength of 298 MPa and fracture elongation of about 30% were obtained in the UFG alloy. A transition from ductile–brittle to ductile fracture consisting of very fine and equiaxed dimples was also found in the ECAP processed material. Compared to the as-received alloy, a combination of grain refinement and texture development in the UFG alloy gave rise to a notable reduction in mechanical asymmetric behavior at room temperature. The superplastic behavior of the as-extruded and ECAP processed alloy was also investigated at 200˚C with strain rate of 1.0×10-3 s-1. The concurrent effect of grain boundary sliding and favorable basal texture in the UFG alloy led to an achievement of elongation value of about 300% while, under similar testing conditions, the elongation of about 140% was obtained in the as-extruded alloy

    Electric field control of multiferroic domains in Ni3_3V2_2O8_8 imaged by X-ray polarization enhanced topography

    Full text link
    The magnetic structure of multiferroic Ni3_3V2_2O8_8 has been investigated using non-resonant X-ray magnetic scattering. Incident circularly polarized X-rays combined with full polarization analysis of the scattered beam is shown to yield high sensitivity to the components of the cycloidal magnetic order, including their relative phases. New information on the magnetic structure in the ferroelectric phase is obtained, where it is found that the magnetic moments on the "cross-tie" sites are quenched relative to those on the "spine" sites. This implies that the onset of ferroelectricity is associated mainly with spine site magnetic order. We also demonstrate that our technique enables the imaging of multiferroic domains through polarization enhanced topography. This approach is used to image the domains as the sample is cycled by an electric field through its hysteresis loop, revealing the gradual switching of domains without nucleation.Comment: 9 pages, 6 figure

    Autophagy in trimethyltin-induced neurodegeneration

    Get PDF
    Autophagy is a degradative process playing an important role in removing misfolded or aggregated proteins, clearing damaged organelles, such as mitochondria and endoplasmic reticulum, as well as eliminating intracellular pathogens. The autophagic process is important for balancing sources of energy at critical developmental stages and in response to nutrient stress. Recently, autophagy has been involved in the pathophysiology of neurodegenerative diseases although its beneficial (pro-survival) or detrimental (pro-death) role remains controversial. In the present review, we discuss the role of autophagy following intoxication with trimethyltin (TMT), an organotin compound that induces severe hippocampal neurodegeneration associated with astrocyte and microglia activation. TMT is considered a useful tool to study the molecular mechanisms occurring in human neurodegenerative diseases such as Alzheimer’s disease and temporal lobe epilepsy. This is also relevant in the field of environmental safety, since organotin compounds are used as heat stabilizers in polyvinyl chloride polymers, industrial and agricultural biocides, and as industrial chemical catalysts

    Papel etiológico de los virus en la enfermedad periodontal

    Get PDF
    El objetivo de esta revisión es presentar la evidencia disponible que relaciona la infección por virus con el desarrollo de periodontitis. Esta relación se ha visto con los virus de la familia herpes, sobretodo el citomegalovirus humano (CMV) y el virus Epstein-Barr (VEB), así como con el virus de la inmunodeficiencia humana (HIV). Las infecciones por herpesvirus generalmente sucede en dos fases, durante la primoinfección la clínica suele ser leve o asintomática y a esta le sigue una fase asintomática en la que el virus se encuentra en estado de latencia. Dicho estado se verá interrumpido esporádicamente por periodos de activación en los que se produce una replicación viral y posiblemente se dé una manifestación de la enfermedad que explicaría, en parte, el progreso en episodios de la enfermedad periodontal. De hecho, algunas de las causas que llevan a la reactivación del virus también se consideran factores de riesgo de la enfermedad periodontal y podrían relacionar a ambas patologías. The purpose of this review is to evaluate the evidence supporting the hypothesis that viral infection plays a role in the development of periodontitis. This relationship has been found mainly with the herpesvirus family, especially with human cytomegalovirus (CMV) and with Epstein-Barr virus (EBV), but also with human immunodeficiency virus (HIV). The herpesvirus infection generally involves a mild or asymptomatic primary phase followed by an asymptomatic latent phase interrupted sporadically by periods of activation, where viral replication and possibly clinical disease become manifest and which will in part, explain the episodic progressive nature of human periodontitis. In fact, herpesvirus reactivation is triggered by a number of immunosuppressing factors, some of which have also been shown to be risk indicators of periodontal disease and which could relate both patologies

    Experimental Validation of the Innovative Thermal Energy Storage Based on an Integrated System "Storage Tank/Steam Generator"

    Get PDF
    Abstract In the past years, an innovative thermal energy storage system at high temperature (up to 550C) for CSP plants was proposed by ENEA and Ansaldo Nucleare: a single storage tank integrated with a steam generator immersed in the heat storage medium. The idea is based on the exploitation of the thermophysical characteristics of the heat storage medium (a binary mixture of salts of NaNO3 at 60% and KNO3 at 40%) in order to maintain over time, in the single tank, a thermal stratification of the fluid. The thermal stratification is able to trigger, in the immersed steam generator, the natural circulation, shell side and downwards, of the hot molten salt cooled down by the water that flows upwards tube side, thus heating up and producing superheated steam. The advantages of such a system are: - efficient performances; - simple implementation; - compactness: - modularity; - and, overall, contained costs: only one storage tank instead of the two tanks and only one heat exchanger instead of the three exchangers of the classic configuration; reduced quantity of salt; minimization of piping, valves and other components. The technical feasibility of the proposed system, together with the stability over time of the stratification in temperature of the storage medium, have been already verified and assessed. This report has the aim of presenting the experimental results obtained by ENEA in the Casaccia Research Centre (Rome, Italy), with a small scale test section consisting of a 300 kWth steam generator inserted in a 8 m3 storage tank with molten salt at high temperature. The reported results relate to the behaviour of the system in steady state conditions, and show its promising performances

    An innovative concept of a thermal energy storage system based on a single tank configuration using stratifying molten salts as both heat storage medium and heat transfer fluid, and with an integrated steam generator

    Get PDF
    Abstract The proposed innovative thermal energy storage system is based on a single tank containing a mixture of nitrate salts (60% NaNO3 and 40% KNO3 in weight; this mixture gradually changes from solid to liquid in the temperature range between about 220 °C and 240 °C, becoming completely melted above this temperature), with an integrated steam generator directly contained inside it. The system is operated exploiting the thermal stratification of the salts mixture in the temperature range between 550 °C (hot temperature) and 290 °C (cold temperature). The experimental work conducted at ENEA has revealed that the thermal stratification of the molten salts mixture can be maintained quite constant for several hours and the presence of the integrated steam generator actively guarantees and maintains the stratification during the operation time, avoiding mixing of the stratified layers. The single-tank system with stratification of the molten salts and an integrated steam generator is an important improvement in terms of efficiency, reliability and cost reduction, with respect to the two-tank thermal energy storage system. This report has the aim of giving an overview of this new technology but, given the fact that the experimental activities are still ongoing, the description of the system remains at a qualitative level. The complete set of experimental results will be presented in the future when the Projects that are framework of this research will have been completed
    • …
    corecore