461 research outputs found

    Sulforaphane causes cell cycle arrest and apoptosis in human glioblastoma u87mg and u373mg cell lines under hypoxic conditions

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    Glioblastoma multiforme (GBM) is the most prevalent and aggressive primary brain tumor. The median survival rate from diagnosis ranges from 15 to 17 months because the tumor is resistant to most therapeutic strategies. GBM exhibits microvascular hyperplasia and pronounced necrosis triggered by hypoxia. Sulforaphane (SFN), an isothiocyanate derived from cruciferous vegetables, has already demonstrated the ability to inhibit cell proliferation, by provoking cell cycle arrest, and leading to apoptosis in many cell lines. In this study, we investigated the antineoplastic effects of SFN [20–80 µM for 48 h] in GBM cells under normoxic and hypoxic conditions. Cell viability assays, flow cytometry, and Western blot results revealed that SFN could induce apoptosis of GBM cells in a dose-dependent manner, under both conditions. In particular, SFN significantly induced caspase 3/7 activation and DNA fragmentation. Moreover, our results demonstrated that SFN suppressed GBM cells proliferation by arresting the cell cycle at the S-phase, also under hypoxic condition, and that these effects may be due in part to its ability to induce oxidative stress by reducing glutathione levels and to increase the phosphorylation of extracellular signal-regulated kinases (ERKs). Overall, we hypothesized that SFN treatment might serve as a potential therapeutic strategy, alone or in combination, against GBM

    Tailored Torsion and Bending-Resistant Avian-Inspired Structures

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    The escalating demand for torsion- and bending-resistant structures paired with the need for more efficient use of materials and geometries, have led to novel bio-inspired ingenious solutions. However, lessons from Nature could be as inspiring as they are puzzling: plants and animals offer an enormous range of promising but hierarchically complex configurations. Avian bones are prominent candidates for addressing the torsional and bending issue. They present a unique intertwining of simple components: helicoidal ridges and crisscrossing struts, able to bear flexural and twisting actions of winds. Here, it is set how to harmonically move from the natural to the engineering level to formalize and analyze the biological phenomena under controlled design conditions. The effect of ridges and struts is isolated and combined toward tailored torsion and bending-resistant arrangements. Then the biological level is revisited to extrapolate the avian allometric design approach and is translated into multiscale lightweight structures at the engineering level. This study exploits the complexity of Nature and the scalability that characterizes the evolutionary design of bird bones through the design and fabrication versatility allowed by additive manufacturing technologies. This paves the way for exploring the transferability of the proposed solution at multiple engineering scales

    Manganite/Alq3 interfaces investigated by impedance spectroscopy technique

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    With the general objective of studying interfaces between ferromagnetic materials and organic semiconductors, we report ac impedance investigations on La0.7Sr0.3MnO3 (LSMO)/tris(8-hydroxyquinoline)aluminium (Alq3)/Al and Indium Tin Oxide (ITO)/Alq3/Al heterostructures, in the frequency range between 20 Hz and 1 MHz. The comparison of the equivalent circuits deduced to fit the experimental ac responses allows isolating a specific RC contribution which can be attributed to the LSMO/Alq3 interface region. Using the information obtained from our ac measurements, we propose a model which fits the temperature dependence of the magnetoresistance in spin valves combining LSMO electrodes and Alq3 layers

    Activity and analysis of costs in a dedicated weaning centre.

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    AIM: To analyse the diagnosis-related characteristics and the costs of treating patients with difficult/prolonged weaning from mechanical ventilation we have undertaken a retrospective observational study. METHODS: The study has considered all the patients admitted to our weaning unit of a regional Rehabilitation department during 3 consecutive periods since the opening date. Characteristics of the admitted patients and the DRG-related cares delivered have been recorded. A cost analysis has been obtained over time. RESULTS: The number of beds allocated to this unit (from 4 in the 1st period to 6 in the 2nd and 3rd periods) and the number of patients cared for (from 32 to 43 and to 65, respectively) increased over time. In particular, the COPD to non-COPD patient ratio (from 2.2 to 1.3 and to 1.0) and the DRG/patient weight (from 3.0 +/- 0.3 to 3.1 +/- 0.2 and to 3.3 +/- 0.2 point) changed significantly (p < 0.05). The daily reimbursement per patient from the public health care system only slightly increased, whereas the operating margin (reimbursement less costs) per patient significantly improved (from -304, to +17 and +55 Euro/pt/day, respectively, p < 0.05) due to a gradual restriction in the variable costs. Length of stay, mortality rate and weaning rate did not change over time. CONCLUSION: The weaning centre is a hospital area where economic burdens should be carefully evaluated. Given the actual reimbursement received on a national level for these patients, variable costs might be better spread, thus optimising the burdens without losing out on clinical outcomes

    Design and 3D printing of a modular phantom of a uterus for medical device validation

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    PurposeThe purpose of this study is to describe the design and validation of a three-dimensional (3D)-printed phantom of a uterus to support the development of uterine balloon tamponade devices conceived to stop post-partum haemorrhages (PPHs). Design/methodology/approachThe phantom 3D model is generated by analysing the main requirements for validating uterine balloon tamponade devices. A modular approach is implemented to guarantee that the phantom allows testing these devices under multiple working conditions. Once finalised the design, the phantom effectiveness is validated experimentally. FindingsThe modular phantom allows performing the required measurements for testing the performance of devices designed to stop PPH. Social implicationsPPH is the leading obstetric cause of maternal death worldwide, mainly in low- and middle-income countries. The proposed phantom could speed up and optimise the design and validation of devices for PPH treatment, reducing the maternal mortality ratio. Originality/valueTo the best of the authors' knowledge, the 3D-printed phantom represents the first example of a modular, flexible and transparent uterus model. It can be used to validate and perform usability tests of medical devices

    Surface nanostructures in manganite films

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    Ultrathin manganite films are widely used as active electrodes in organic spintronic devices. In this study, a scanning tunnelling microscopy (STM) investigation with atomic resolution revealed previously unknown surface features consisting of small non-stoichiometric islands. Based upon this evidence, a new mechanism for the growth of these complex materials is proposed. It is suggested that the non-stoichiometric islands result from nucleation centres that are below the critical threshold size required for stoichiometric crystalline growth. These islands represent a kinetic intermediate of single-layer growth regardless of the film thickness, and should be considered and possibly controlled in manganite thin-film applications

    Diagnostic and therapeutic aspects of hemiplegic migraine

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    Hemiplegic migraine (HM) is a clinically and genetically heterogeneous condition with attacks of headache and motor weakness which may be associated with impaired consciousness, cerebellar ataxia and intellectual disability. Motor symptoms usually last <72 hours and are associated with visual or sensory manifestations, speech impairment or brainstem aura. HM can occur as a sporadic HM or familiar HM with an autosomal dominant mode of inheritance. Mutations in CACNA1A, ATP1A2 and SCN1A encoding proteins involved in ion transport are implicated. The pathophysiology of HM is close to the process of typical migraine with aura, but appearing with a lower threshold and more severity. We reviewed epidemiology, clinical presentation, diagnostic assessment, differential diagnosis and treatment of HM to offer the best evidence of this rare condition. The differential diagnosis of HM is broad, including other types of migraine and any condition that can cause transitory neurological signs and symptoms. Neuroimaging, cerebrospinal fluid analysis and electroencephalography are useful, but the diagnosis is clinical with a genetic confirmation. The management relies on the control of triggering factors and even hospitalisation in case of long-lasting auras. As HM is a rare condition, there are no randomised controlled trials, but the evidence for the treatment comes from small studies

    Impact of the scattering physics on the power factor of complex thermoelectric materials

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    We assess the impact of the scattering physics assumptions on the thermoelectric properties of five Co-based p-type half-Heusler alloys by considering full energy-dependent scattering times vs the commonly employed constant scattering time. For this, we employ density functional theory band structures and a full numerical scheme that uses Fermi's golden rule to extract the momentum relaxation times of each state at every energy, momentum, and band. We consider electron-phonon scattering (acoustic and optical), as well as ionized impurity scattering, and evaluate the qualitative and quantitative differences in the power factors of the materials compared to the case where the constant scattering time is employed. We show that the thermoelectric power factors extracted from the two different methods differ in terms of (i) their ranking between materials, (ii) the carrier density where the peak power factor appears, and (iii) their trends with temperature. We further show that the constant relaxation time approximation smoothens out the richness in the band structure features, thus limiting the possibilities of exploring this richness for material design and optimization. These details are more properly captured under full energy/momentum-dependent scattering time considerations. Finally, by mapping the conductivities extracted within the two schemes, we provide appropriate density-dependent constant relaxation times that could be employed as a fast first-order approximation for extracting charge transport properties in the half-Heuslers we consider
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