2,373 research outputs found
Swelling process induced by Focused Ion Beam on magnetic layers
No full textThe ability to prepare ordered arrays of micro/nano sized magnetic elements offers the chance to investigate magnetic properties at length scales previously inaccessible. Bi-dimensional ordered array of magnetic dots can be obtained through a number of different techniques.
Patterning of extended magnetic layers or multilayers by Focused Ion Beam (FIB) is one of the most powerful approaches for nano-structuration on a large variety of materials due to the high spatial resolution, good process control and elevated flexibility. This enables a very high accuracy to be achieved in the refinement (shape, sharpness, orientation and dimension) of each individual element and of the separation between the elements. On the other hand ion interactions with solids produce several damage effects. These effects can be very severe in the case of crystalline solids and of nano-sized elements, and can influence magnetic properties of the systems (magneto-crystalline and configurational anisotropy).
We studied by AFM and Depth Profile Auger analysis the ions effect on a submicron scale dots array obtained on a 10nm Fe/10nm NiO/MgO(001) multilayer capped with 10nm of MgO. Ion-induced local damage leads to a significant swelling effect on the nano-structures [1]. Our measurements suggest that swelling observed on the multilayer originates from substrate ion irradiation.
Transmission Electron Microscopy and diffraction technique measurements should give structural information and clarify the relations between ion induced damage and swelling effect.
[1] G. C. Gazzadi, P. Luches, S. F. Contri, A. di Bona, S. Valeri, Nucl. Instr. Meth. B 230 (2005) 512
Polypharmacological approaches for CNS diseases: focus on endocannabinoid degradation inhibition
No full textPolypharmacology breaks up the classical paradigm of “one-drug, one target, one disease” electing multitarget compounds as potential therapeutic tools suitable for the treatment of complex diseases, such as metabolic syndrome, psychiatric or degenerative central nervous system (CNS) disorders, and cancer. These diseases often require a combination therapy which may result in positive but also negative synergistic effects. The endocannabinoid system (ECS) is emerging as a particularly attractive therapeutic target in CNS disorders and neurodegenerative diseases including Parkinson’s disease (PD), Alzheimer’s disease (AD), Huntington’s disease (HD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), stroke, traumatic brain injury (TBI), pain, and epilepsy. ECS is an organized neuromodulatory network, composed by endogenous cannabinoids, cannabinoid receptors type 1 and type 2 (CB1 and CB2), and the main catabolic enzymes involved in the endocannabinoid inactivation such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). The multiple connections of the ECS with other signaling pathways in the CNS allows the consideration of the ECS as an optimal source of inspiration in the development of innovative polypharmacological compounds. In this review, we focused our attention on the reported polypharmacological examples in which FAAH and MAGL inhibitors are involved
Adenosine Receptors in Neuropsychiatric Disorders: Fine Regulators of Neurotransmission and Potential Therapeutic Targets
No full textAdenosine exerts an important role in the modulation of central nervous system (CNS) activity. Through the interaction with four G-protein coupled receptor (GPCR) subtypes, adenosine subtly regulates neurotransmission, interfering with the dopaminergic, glutamatergic, noradrenergic, serotoninergic, and endocannabinoid systems. The inhibitory and facilitating actions of adenosine on neurotransmission are mainly mediated by A1 and A2A adenosine receptors (ARs), respectively. Given their role in the CNS, ARs are promising therapeutic targets for neuropsychiatric disorders where altered neurotransmission represents the most likely etiological hypothesis. Activating or blocking ARs with specific pharmacological agents could therefore restore the balance of altered neurotransmitter systems, providing the rationale for the potential treatment of these highly debilitating conditions. In this review, we summarize and discuss the most relevant studies concerning AR modulation in psychotic and mood disorders such as schizophrenia, bipolar disorders, depression, and anxiety, as well as neurodevelopment disorders such as autism spectrum disorder (ASD), fragile X syndrome (FXS), attention-deficit hyperactivity disorder (ADHD), and neuropsychiatric aspects of neurodegenerative disorders
Magnetic anisotropy engineering in square magnetic elements
No full textSquare magnetic elements with side in the 100–500nm range have been fabricated using the focused ion beam (FIB) milling techniquefrom a 10 nm thick, single-crystal Fe film, epitaxially grown on MgO(0 0 1). Thanks to the good crystal quality of the film, magneticelements with well-defined magnetocrystalline anisotropy have been prepared, while the fine control of the size and shape of the magnetsallows for the effective engineering of the anisotropic behavior of the magnetostatic energy that determines the so-called configurationalanisotropy. Micromagnetic calculations and experiments show that the angular dependence of the transverse susceptibility has a strongdependence on the material parameters as well as on the static applied field. This allows the effective engineering of the total anisotropyof the magnets.r 2007 Elsevier B.V. All rights reserved
Focused ion beam induced swelling in MgO(001)
No full textThe ability to prepare ordered arrays of micro/nano sized
magnetic elements off ers the chance to investigate magnetic
properties at length scales previously inaccessible.
Patterning of extended magnetic layers or multilayers by
Focused Ion Beam (FIB) is one of the most powerful approaches
for nano-structuration on a large variety of materials,
due to its high spatial resolution, good process control
and elevated fl exibility.
MgO(001) is as a good substrate for UHV epitaxial growth of
multilayers of magnetic interest, such as Fe/NiO: it is magnetically
inert, it has a small lattice mismatch with respect
to NiO and it is cheap and easy to prepare.
In the present work we analyze ion-induced swelling effects
on MgO(001) single crystals as they could infl uence
the structure, morphology and, consequently, the properties
of magnetic arrays prepared by FIB patterning of magnetic
layers on MgO crystalline substrates.
We studied by AFM the ions eff ects on the morphology of
one micron size square dots array obtained on a 5–10 nm
MgO/10 nm Fe/MgO(001) multilayers. A Fe interlayer has
been deposited to avoid electronic charging that restricts
ion beam effi ciency. 30 keV, 5x1016 Ga+cm-2 bombardment
leads to a signifi cant swelling eff ect (4–6 nm protrusion) on
the patterned areas. Electron diff raction and Auger depth
profi le measurements suggest that the observed swelling
mainly originates from MgO structural damage
Needs of breast cancer survivors: a systematic review of quantitative data
No full textThis systematic review aimed to update the perceived needs of individuals with breast cancer (BC). Databases were searched for studies reporting quantitative data collected through validated assessment tools. Needs of adults with BC were reported by survivorship phase. The post-diagnosis and the post-surgery phases revealed the most needs; health system and information needs represented the greatest concern, with average Supportive Care Needs Survey-Short Form (SCNS-SF34) scores ranging from 62.0 to 75.8 post-diagnosis and from 45.0 to 67.8 post-surgery. Needs then seemed to decrease or remain stable up to within one year from diagnosis, when needs in all domains increased again; health system and information needs remained a priority. Younger age, side effects, type of treatment, and advanced stage were associated with the occurrence of unmet needs. The needs of BC survivors vary over the course of their cancer experience. This knowledge can assist the planning of appropriate assessments
Characteristics of frozen epididymal spermatozoa from stallions that died 12 to 36 hours after colic surgery
No full textEquine spermatozoa from the cauda epididymis were previously collected and frozen, and the fertility was assessed. Most studies were performed on healthy stallions that had undergone routine castration or on the epididymis collected at the abattoir, but there are no studies on the quality of epididymal semen in subjects which have died from colic or which underwent intensive care. The present study was designed to verify whether a severe illness could affect epididymal semen quality and freezability in the stallion. Therefore, epididymal semen characteristics during the freezing process in stallions which had died from colic and in healthy stallions submitted to elective castration were compared. Five stallions that had died from colic (ill stallions [ISs]) and seven stallions that had undergone elective castration (healthy stallions) were castrated, and cauda epididymis spermatozoa were collected and processed. Sperm quality was tested after collection, after washing procedures, at the end of the equilibration (5 °C for 75 minutes), and after freezing/thawing. Sperm quality was measured by objective motility characteristics, membrane and acrosome integrity, and mitochondrial activity. After collection, sperm in ISs showed low kinetic parameters (total motility: 17.3 ± 3%, progressive motility: 6 ± 1%, average path velocity: 57.4 ± 35.4 mm/s, straightness: 74.2%) compared with healthy stallions (total motility: 90.8 ± 3.7%, progressive motility: 70 ± 4%, average path velocity: 118.1 ± 12.6 mm/s, straightness: 82.4%) but demonstrated similar membrane and acrosome integrity (85 ± 2.8% vs. 87.6 ± 3.1%). Sperm kinetic parameters increased after washing procedures and cooling in ISs, reaching comparable values after equilibration (5 °C for 75 minutes) and freezing/thawing. The data reported in this study suggest that the quality of the equine epididymal spermatozoa cryopreserved in stallions that had died from colic was similar to that reported in epididymal sperm after elective castration and was also similar to the data reported in literature for cryopreserved equine semen
Local modifications of magnetism and structure in FePt (001) epitaxial thin films by focused ion beam: two-dimensional perpendicular patterns
No full textFocused ion beam was utilized to locally modify magnetism and structure of L10 FePt perpendicularthin films. As a first step, we have performed a magnetic, morphological, and structural study ofcompletely irradiated FePt films with different Ga+ doses 11013 –41016 ions/cm2 and ionbeam energy of 30 keV. For doses of 11014 ions/cm2 and above a complete transition from theordered L10 to the disordered A1 phase was found to occur, resulting in a drop of magneticanisotropy and in the consequent moment reorientation from out-of-plane to in-plane. The lowesteffective dose in disordering the structure 11014 ions/cm2 was found not to affect the filmmorphology. Taking advantage of these results, continuous two-dimensional 2D patterns ofperpendicular magnetic structures 250 nm dots, 1 m dots, 1 m-large stripes were produced byfocused ion beam without affecting the morphology. The 2D patterns were revealed by means ofmagnetic force microscopy, that evidenced peculiar domain structures in the case of 1 m dots.© 2008 American Institute of Physics
Il parto dell’asina e le prime ore di vita del puledro : osservazioni
No full textThe aim of the present study was to evaluate the duration of each phase of parturition and to assess some neonatal parameters Martina Franca donkeys. The 11 jennies had normal parturition. Data grouped depending on the sex of the foal, showed that only gestation length and foal birthweigth were significantly higer in male foals
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