Barrier Suppression Research Articles

Ionisation in nanowire by ultra-short relativistic laser pulse

We show that the wakefield driven by fast electrons inside the nanowire when irradiated with an ultra-short relativistic laser pulse strips atoms to a higher charge state. Using particle-in-cell simulations, we demonstrate that the charge state agrees with the barrier suppression threshold of the wakefield and reaches a higher value via collision. The ionisation of gold nanowires occurs only via collisional-damped wakefield. We found that the collisional ionisation of high-Z nanowires depends on the onset of the z pinch. These results suggest a different ionisation mechanism of the structured target in the subfemtosecond regime.

Kaempferol-3-O-(2″-O-galloyl-β-D-glucopyranoside): a novel neuroprotective agent from Diospryros kaki against cerebral ischemia-induced brain injury.

Our previous study demonstrated neuroprotective and therapeutic effects of a standardized flavonoid extract from leaves of Diospyros kaki L.f. (DK) on middle cerebral artery occlusion-and-reperfusion (MCAO/R)-induced brain injury and its underlying mechanisms. This study aimed to clarify flavonoid components responsible for the effects of DK using in vitro and in vivo transient brain ischemic models. Organotypic hippocampal slice cultures (OHSCs) subjected to oxygen- and glucose-deprivation (OGD) were performed to evaluate in vitro neuroprotective activity of DK extract and nine isolated flavonoid components. MCAO/R mice were employed to elucidate in vivo neuroprotective effects of the flavonoid component that exhibited the most potent neuroprotective effect in OHSCs. DK extract and seven flavonoids [quercetin, isoquercetin, hyperoside, quercetin-3-O-(2″-O-galloyl-β-D-galactopyranoside), kaempferol, astragalin, and kaempferol-3-O-(2″-O-galloyl-β-D-glucopyranoside) compound (9)] attenuated OGD-induced neuronal cell damage and compound (9) possessed the most potent neuroprotective activity in OHSCs. The MCAO/R mice showed cerebral infarction, massive weight loss, characteristic neurological symptoms, and deterioration of neuronal cells in the brain. Compound (9) and a reference drugs, edaravone, significantly attenuated these physical and neurological impairments. Compound (9) mitigated the blood-brain barrier dysfunction and the change of glutathione and malondialdehyde content in the MCAO mouse brain. Edaravone suppressed the oxidative stress but did not significantly affect the blood-brain barrier permeability. The present results indicated that compound (9) is a flavonoid constituent of DK with a potent neuroprotective activity against transient ischemia-induced brain damage and this action, at least in part, via preservation of blood-brain barrier integrity and suppression of oxidative stress caused by ischemic insult.

The chicken or the egg of lymphopenia in atopic eczema.

Lymphopenia has been documented in atopic eczema (AE) patients mostly in the setting of an active infection.1, 2 However, the question is whether lymphopenia is a primary problem in AE leading to infection or it is a secondary problem due to infection. In the study by Hollestein et al.,3 the authors conducted a retrospective review of a large electronic database (UK primary care electronic health record from CPRD GOLD). They included 71,731 adults with AE and 126,349 adults without AE. Using the definition of lymphopenia as having two lymphocyte counts of <1 × 109/L in 3 months, they showed that 4.1% (n = 2909) of AE patients had lymphopenia as compared to 3.7% (n = 4700) of controls without AE. The adjusted OR for lymphopenia in AE patients as compared to those without AE was 1.16 and this increased to 1.89 in patients with severe AE. Their data were appropriately adjusted for age, sex, ethnicity, smoking, co-morbidities and immunosuppressive drug use. In their secondary analysis, they confirmed an increased risk of skin and systemic infections including cellulitis, varicella zoster, gastroenteritis and urinary tract infection in AE patients as compared to controls. The authors also replicated their findings of lymphopenia in AE patients based in a US database, NHANES. Their data support the hypothesis that lymphopenia may predispose to increased infections in AE patients. A possible mechanism of lymphopenia in AE patients is due to the homing of systemic lymphocytes to inflamed skin. Their finding of a higher risk of lymphopenia in more severe AE is also consistent with this mechanism. While Hollestein et al. have provided a robust and well-controlled study that lymphopenia may be a primary problem in AE patients, the findings can only be inferred as an association, rather than cause-and-effect, due to the retrospective nature of the study. In a real-life clinical situation, complete blood cell (CBC) profile is normally sent when a patient is symptomatic, that is, during an illness or an infection. Acute lymphopenia is common with viral respiratory infections.4 In AE patients, CBC may also be sent together with viral or bacterial identification testing during a skin infection, which may be associated with lymphopenia.1, 2 AE patients are not known to have a primary immunodeficiency that predisposes them to have increased infection. However, skin and soft tissue infections are more common in AE patients due skin barrier defects and suppression of cutaneous innate immunity by type 2 cytokines.5 The results of Hollestein et al. are nevertheless interesting, and will need to be confirmed with prospective studies. None to declare. P. Ong reports no conflict of interest relevant to this article. Data sharing not applicable.

Energy scaling of the product state distribution for three-body recombination of ultracold atoms

Three-body recombination is a chemical reaction where the collision of three atoms leads to the formation of a diatomic molecule. In the ultracold regime it is expected that the production rate of a molecule generally decreases with its binding energy ${E}_{b}$, however, its precise dependence and the physics governing it have been left unclear so far. Here we present a comprehensive experimental and theoretical study of the energy dependency for three-body recombination of ultracold Rb. For this, we determine production rates for molecules in a state-to-state resolved manner, with the binding energies ${E}_{b}$ ranging from 0.02 to 77 $\mathrm{GHz}\ifmmode\times\else\texttimes\fi{}h$. We find that the formation rate approximately scales as ${E}_{b}^{\ensuremath{-}\ensuremath{\alpha}}$, where $\ensuremath{\alpha}$ is in the vicinity of 1. The formation rate typically varies only within a factor of two for different rotational angular momenta of the molecular product, apart from a possible centrifugal barrier suppression for low binding energies. In addition to numerical three-body calculations we present a perturbative model which reveals the physical origin of the energy scaling of the formation rate. Furthermore, we show that the scaling law potentially holds universally for a broad range of interaction potentials.

Transient Laser-Induced Breakdown of Dielectrics in Ultrarelativistic Laser-Solid Interactions

For high-intensity laser-solid interactions, the absolute density and surface density gradients of the target at the arrival of the ultrarelativistic laser peak are critical parameters. Accurate modeling of the leading edge-driven target preexpansion is desired to strengthen the predictive power of associated computer simulations. The transition from an initial solid state to a plasma state, i.e., the breakdown of the solid, defines the starting point of the subsequent target preexpansion. In this work, we report on the time-resolved observation of transient laser-induced breakdown (LIB) during the leading edge of high-intensity petawatt-class laser pulses with peak intensities of up to 5.7×1021W/cm2 in interaction with dielectric cryogenic hydrogen jet targets. LIB occurs much earlier than what is typically expected following the concept of barrier suppression ionization. The observation is explained by comparing a characterization study of target-specific LIB thresholds with laser contrast measurements. The results demonstrate the relevance of the laser pulse duration dependence of LIB for high-intensity laser-solid interactions. We provide an effective approach to determine the onset of LIB and thereby the starting point of target preexpansion in other laser-target systems.Received 28 July 2022Revised 2 December 2022Accepted 16 December 2022DOI:https://doi.org/10.1103/PhysRevApplied.19.014070Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasHigh intensity laser-plasma interactionsLight-matter interactionPlasma production & heating by laser beams, laser-foil, laser-clusterPhysical SystemsDielectricsRelativistic plasmasTechniquesFemtosecond laser irradiationLaser ablationOptical plasma measurementsPlasma PhysicsCondensed Matter, Materials & Applied PhysicsAtomic, Molecular & Optical

Improving electrical transport properties of AlGaN/GaN heterostructure using AlSiN passivation

AlGaN/GaN heterostructures have been widely used in modern high power and high frequency device applications due to their excellent material characteristics. However, the existence of surface damages, defects and dislocations may degrade the device features. Here, we report the effect of AlSiN surface passivation on electrical transport properties in AlGaN/GaN heterostructure. Compared with the unpassivated, AlN and AlBN passivated AlGaN/GaN, better transport properties have been observed in the AlSiN passivated samples. Both the density and mobility increase in the AlSiN passivated AlGaN/GaN, which may be attributed to the influence of the AlGaN/GaN interface barrier height and suppression of trapping effects. The results show that AlSiN dielectric films is a very promising candidate as surface passivation for AlGaN/GaN HEMTs.

Immune mechanisms of atopic dermatitis and new approaches to targeted biological therapy

This review presents current data on immunopathogenesis, the role of cytokines in inflammation in atopic dermatitis (AD). The pathogenetic phenotypes of the disease associated with various abnormalities of immune mechanisms and dysfunction of the epidermal barrier are considered. The inflammatory processes in atopic dermatitis were shown to be implemented mainly through Th2-lymphocytes and IL-4 and IL-13 produced by these cells, which play a key role in the allergic cascade. It is the effects of IL-4 and IL-13 cytokines that determine the main pathophysiological mechanisms, such as decreased expression of epidermal barrier proteins and suppression of terminal differentiation of keratinocytes, microbiota disturbances, tissue remodelling, immunoglobulin isotype switching by B-lymphocytes and IgE synthesis, degranulation of mast cells and basophils, trafficking of inflammatory cells into tissues, itching. Moderate and severe forms of AD require administration of systemic therapy, which has been represented until recently by non-selective immunosuppressive drugs with moderate efficacy and pronounced side effects if they are used for a long time. Modern targeted therapy of atopic dermatitis provides for the use of monoclonal antibodies against both pro-inflammatory cytokines and their receptors. Directional action on the key mechanisms and targets of immune inflammation can minimize possible side effects of immunosuppressive therapy. Clinical trials on the efficacy and safety of IL-4 and IL-13 inhibitors in the treatment of atopic dermatitis are described.

Obesity Attenuates Ventilator-Induced Lung Injury by Modulating the STAT3-SOCS3 Pathway.

BackgroundVentilator-induced lung injury (VILI) is characterized by vascular barrier dysfunction and suppression of alveolar fluid clearance (AFC). Obesity itself leads to chronic inflammation, which may initiate an injurious cascade to the lungs and simultaneously induce a protective feedback. In this study, we investigated the protective mechanism of obesity on VILI in a mouse model.MethodsThe VILI model was set up via 6-h mechanical ventilation with a high tidal volume. Parameters including lung injury score, STAT3/NFκB pathway, and AFC were assessed. Mice with diet-induced obesity were obtained by allowing free access to a high-fat diet since the age of 3 weeks. After a 9-week diet intervention, these mice were sacrificed at the age of 12 weeks. The manipulation of SOCS3 protein was achieved by siRNA knockdown and pharmaceutical stimulation using hesperetin. WNK4 knockin and knockout obese mice were used to clarify the pathway of AFC modulation.ResultsObesity itself attenuated VILI. Knockdown of SOCS3 in obese mice offset the protection against VILI afforded by obesity. Hesperetin stimulated SOCS3 upregulation in nonobese mice and provided protection against VILI. In obese mice, the WNK4 axis was upregulated at the baseline, but was significantly attenuated after VILI compared with nonobese mice. At the baseline, the manipulation of SOCS3 by siRNA and hesperetin also led to the corresponding alteration of WNK4, albeit to a lesser extent. After VILI, WNK4 expression correlated with STAT3/NFκB activation, regardless of SOCS3 status. Obese mice carrying WNK4 knockout had VILI with a severity similar to that of wild-type obese mice. The severity of VILI in WNK4-knockin obese mice was counteracted by obesity, similar to that of wild-type nonobese mice only.ConclusionsObesity protects lungs from VILI by upregulating SOCS3, thus suppressing the STAT3/NFκB inflammatory pathway and enhancing WNK4-related AFC. However, WNK4 activation is mainly from direct NFκB downstreaming, and less from SOCS3 upregulation. Moreover, JAK2–STAT3/NFκB signaling predominates the pathogenesis of VILI. Nevertheless, the interaction between SOCS3 and WNK4 in modulating VILI in obesity warrants further investigation.

Recent Progress of the Trojan Horse Method and Its Application

The Trojan Horse Method(THM) is an important indirect method in experimental nuclear astrophysics. The S(E) factor of a two-body reaction in Gammow energy range related to astrophysics can be extracted from an appropriate three-body reaction measurement above the Coulomb barrier, under the quasi-free reaction condition. The method can overcome the difficulties caused by the Coulomb barrier suppression and the electron screening effect in direct measurement. While no extrapolation is needed, the method can also avoid the uncertainty in the extrapolation process. THM has a wide application in the experimental nuclear astrophysical study, low-energy fusion data measurement, neutron-induced reaction, electron screening effect and other important research fields. After a short introduction of the THM, this paper will focus on some of the most important experimental results in nuclear astrophysics measured by THM recently and the prospect of its future applications. The following key reactions will mainly be discussed: the indirect measurement of the key neutron source reaction \begin{document}$ ^{{\rm{13}}}{\rm{C(\alpha ,n}}{{\rm{)}}^{{\rm{16}}}}{\rm{O}}$\end{document} in the s-process of AGB stars, the indirect measurement of the nuclear reaction related to the fluorine abundance anomaly in AGB stars, as well as the recent hot spot, the indirect measurement results of the carbon burning reaction in medium or massive stars.

Formula for the ionisation rate of an atom or ion in a strong electromagnetic field for numerical simulation

A formula is proposed for calculating the rate of field ionisation of an atom or ion, taking into account both tunnel ionisation and barrier suppression ionisation. Compared with the previous formula proposed in 2018, it more accurately describes the transition region between both ionisations and is determined mainly by two parameters: the ionisation potential of an atom or ion and the amplitude of an external electric field. This makes the presented formula suitable for use in numerical packages simulating the interaction of high-power laser radiation with matter by the particle-in-cell (PIC) method.

Small-scale testing of coal dust explosion propagation and relation to active barrier suppression systems

Abstract Coal dust explosions are a lethal threat to anyone working in an underground coal mine. Many coal mining countries including Australia and much of Europe already utilize passive barrier explosion suppressant systems but due to differences in ventilation patterns in the United States, simple passive systems such as the bagged barrier are not as cost effective. Active systems are triggered by properties of an explosion, such as pressure, heat, or light, and release or project a suppressant into the environment to suppress an explosion. To deploy an active system, the best sensor and suppressant release location and spacing must be determined; this must account for total system latency and explosive propagation speed. A 10:1 model of a longwall entry system has been developed to study the pressure wave propagation of coal dust explosions and consequent triggering of different suppressants. The scaled model, with its removable stoppings, allows multiple potential propagation pathways for an explosion to be repeatedly tested, different from typical straight shock tunnel tests. The layout also facilitates the placement of sensors and cameras to fully observe and document the tests. The pressure wave characteristics found at crosscuts and corners will aid in the development of active barrier trigger systems and spacing of suppressant release locations.

Trapping and electrical characterization of single core/shell iron-based nanoparticles in self-aligned nanogaps

We report on the fabrication and measurements of platinum-self-aligned nanogap devices containing cubed iron (core)/iron oxide (shell) nanoparticles (NPs) with two average different sizes (13 and 17 nm). The nanoparticles are deposited by means of a cluster gun technique. Their trapping across the nanogap is demonstrated by comparing the current vs voltage characteristics (I-Vs) before and after the deposition. At low temperature, the I-Vs can be well fitted to the Korotkov and Nazarov Coulomb blockade model, which captures the coexistence of single-electron tunneling and tunnel barrier suppression upon a bias voltage increase. The measurements thus show that Coulomb-blockaded devices can be made with a nanoparticle cluster source, which extends the existing possibilities to fabricate such devices to those in which it is very challenging to reduce the usual NP agglomeration given by a solution method.

Probiotics for dietary management of non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is characterized by an increase in fat content of liver cells, which is independent from alcohol intake. Here, we review the impact of microbiota and diet on the pathogenesis of NAFLD and the present knowledge on the effect of probiotics for dietary management of NAFLD. The major points are the following: (1) dietary preference of a high fructose and/or high fat diet seems to be associated with NAFLD. (2) Different microbial metabolites, including short chain fatty acids and ethanol, are associated with increased levels of lipogenesis. (3) Ethanol is metabolized to acetaldehyde resulting in increased oxidative stress and consecutively in liver injury. (4) Ethanol may also impair gut barrier function, which may enable translocation of lipopolysaccharides from Gram-negative bacteria and, hence, further promote low grade inflammation in liver tissue. (5) Beneficial gut microbiota may counteract the pathogenesis of NAFLD through displacement of NAFLD promoting microbes, reduction of overall microbial ethanol production, promotion of gut barrier function and suppression of inflammatory cascades. Therefore, selective probiotic strains with proven efficacy for NAFLD management and validated safety can be considered as a promising approach for NAFLD management.

Abstract 5013: NG-641: An oncolytic T-SIGn virus targeting cancer-associated fibroblasts in the stromal microenvironment of human carcinomas

Abstract NG-641 is a modified variant of enadenotucirev (EnAd), an Ad11p/Ad3 chimeric group B adenovirus, which retains all the functional properties of enadenotucirev while also expressing transgenes designed to target breakdown of the stromal barrier and immune suppression within the tumor microenvironment. Enadenotucirev has potent and selective anti-tumor activity against a range of epithelial cancer cells, with a blood stability profile that enables systemic dosing; it has now been administered intravenously to over 100 cancer patients. As an approach to immunogene therapy targeting stromal rich tumors, we have created a transgene-modified variant of EnAd expressing a bi-specific T-cell activator molecule (FAP-TAc) recognizing fibroblast activating protein (FAP) on cancer associated fibroblasts (CAFs) and CD3 on T-cells. Production of FAP-TAc by virus infected tumor cells should lead to T-cell mediated killing of CAFs and thus modification of the tumor microenvironment to drive effective anti-tumor immunity. This local production approach also bypasses potential delivery and safety issues associated with systemic dosing of such molecules. To enhance the activity of the FAP-TAc molecule, particularly in tumors with poor immune cell infiltration (“excluded” or “immune desert” phenotypes), NG-641 also encodes the transgenes CXCL9, CXCL10 and IFNα to recruit T-cells and enhance the overall immune response and cancer cell killing. Initial studies with different viruses expressing FAP-TAc alone showed that FAP-TAc activity generated by NG-641 infection was essentially the same as that with viruses bearing only the FAP-TAc transgene. Following infection of tumor cells with NG-641, the virus selectively secretes functional FAP-TAc molecules, as determined in cocultures of FAP+ fibroblasts and T cells. Production of CXCL9, CXCL10 and IFNα was confirmed by ELISA assays, with functionality evaluated by reporter cell, FACS and cell migration assays. T cell-activation mediated by FAP-TAc lead to cytokine secretion and cytotoxicity towards the fibroblasts, both of which were enhanced by expression of the IFNα transgene. Studies with primary human tumor samples (containing tumor cells, CAFs and infiltrated immune cells) also demonstrated potent activation of the endogenous T-cells, indicating that virus produced FAP-TAc is a potent T-cell activator despite suppressive influences of the tumor microenvironment. In conclusion, we have shown that CAFs can be effectively targeted for T-cell mediated destruction by NG-641, a tumor stroma targeting transgene-bearing oncolytic virus. This is associated with strong activation of endogenous T-cells to kill CAFs even in the presence of an immunosuppressive microenvironment. Systemic dosing of such a virus to patients with stromal rich tumors may provide an effective approach for driving productive anti-tumor immunity. Citation Format: Brian R. Champion, Matthieu Besneux, Marilena Patsalidou, Ana Silva, Manuela Zonca, Nalini Marino, Gianfranco di Genova, Sam Illingworth, Stefania Fedele, Lorna Slater, Fred Lilley, Darren Plumb, Katy West, Paul Cockle, Alice Brown. NG-641: An oncolytic T-SIGn virus targeting cancer-associated fibroblasts in the stromal microenvironment of human carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5013.

High-order harmonic generation in H2+ via multicolor beam superposition: barrier suppression ionization regime

Generation of high-order harmonics (HOHs) and attosecond pulses in the barrier suppression ionization regime for a target of hydrogen molecular ion, $${\text{H}}_{2}^{+}$$ , with large inter nuclear distance is introduced in this work. Some broadband femtosecon laser pulses are designed based on multicolor beam superposition method in order to interact with $${\text{H}}_{2}^{+}$$ . Behavioral study of harmonics cutoff, attosecond pulse widths and intensities, along with the maximum ionization intensity with respect to the spectral width of driving pulses was carried out. Molecular orbitals in this study are estimated via the linear combination of atomic orbital approximation, and temporal variations of these orbitals are studied in the various ionization regimes. It is seen in this work that although the cutoff harmonic is increased by the driving pulse intensity, but it is insensitive to the spectral driving pulsewidth. This study showed that intensities of the generated attosecond pulses gradually decreased by increasing the bandwidth of the driving laser pulse, but the duration of them is shown to be insensitive in this respect.

Magnetic quantum number dependence of hydrogen photoelectron spectra under circularly polarized pulse in barrier suppression ionization regime

Photoelectron spectra and transition mechanisms of a hydrogen atom in the n = 2 state under circularly polarized pulses in the barrier suppression ionization (BSI) regime, found by solving the time-dependent Schrödinger equation, are presented in detail. The photoelectron peak emerges from low-energy, in contrast to being centered at higher energy in the case of ionization from the ground state. We show that the magnetic quantum number dependence of photoelectron angular distributions on initial states yields 3- and 2-band structures for 2p− and 2p0 in zenith angle, respectively, and 1-band structures for both 2p+ and 2s. The intermediate transition pathways from these initial states to the corresponding final states are also revealed.

Coupled-cluster treatment of molecular strong-field ionization.

Ionization rates and Stark shifts of H2, CO, O2, H2O, and CH4 in static electric fields have been computed with coupled-cluster methods in a basis set of atom-centered Gaussian functions with a complex-scaled exponent. Consideration of electron correlation is found to be of great importance even for a qualitatively correct description of the dependence of ionization rates and Stark shifts on the strength and orientation of the external field. The analysis of the second moments of the molecular charge distribution suggests a simple criterion for distinguishing tunnel and barrier suppression ionization in polyatomic molecules.

Anti-allergic effects of novel sulfated polysaccharide sacran on mouse model of 2,4-Dinitro-1-fluorobenzene-induced atopic dermatitis

In this study, in order to investigate the potential of the novel polysaccharide sacran from Aphanothece Sacrum for development of atopic dermatitis (AD), we evaluated the potential of pretreatment with topical sacran to prevent the development of hapten (dinitrofluorobenzene: DNFB)-induced AD-like disease in mice. In the AD model mice, sacran markedly ameliorated AD symptoms such as scratching behavior and edema in ear. In addition, sacran significantly increased water content of the stratum corneum which regulates the skin barrier function. Furthermore, sacran significantly inhibited inflammatory cytokine and chemokine mRNA levels in the dermatitis skin as well as the IgE antibody level in serum. Sacran inhibited inflammatory cytokines mRNA production from Jurkat cells derived from human leukemia T cells after stimulation with phorbol 12-myristate 13-acetate/ionomycin. Meanwhile, sacran did not inhibit the proliferation of primary B cells stimulated with lipopolysaccharide. These results suggest that sacran has good anti-allergic effect on AD model mice, probably due to the amelioration of skin barrier function and suppression of immune responses.

Chronic exposure to TNFα impairs RPE barrier and immunosuppressive functions

PurposeThe retinal pigment epithelium (RPE) is a monolayer of pigmented cells with important roles in the outer blood‐retinal barrier and subretinal immune suppression. Failure of RPE functions and inflammation have both been hypothesized to play a role in the pathophysiology of age related macular degeneration (AMD). We here investigated the long‐term effects of TNFα on RPE morphology and function in vitro.MethodsPrimary porcine RPE cells were cultivated until confluence, then recombinant TNFα was added daily in the culture medium (at 0.8, 4, 20 or 100 ng/ml=C1,C2,C3 and C4) for 10 days. RPE cell morphology and gene expression, barrier, phagocytosis and immunosuppressive functions were assessed.ResultsCell morphology and gene expression:TNFα (i) decreased cell number (3653.6,3428,3227,2791 and 2020 cells/mm2 respectively for control,C1,C2,C3 and C4, all p &lt; 0.01); (ii) increased cell size (+5.3,+12.6,+13.9 and +9.5% of control for C1,C2,C3 and C4, all p &lt; 0.05); (iii) increased the % of multinucleated cells (5.7,7.7,9.4,9.9 and 15.9% of multinucleated cells for control,C1,C2,C3 and C4, all p &lt; 0.05); (iv) and decreased OTX2 (a major RPE gene) expression (‐11.1, ‐19.7, ‐52 and ‐82.9% of control for C1,C2,C3 and C4, all p &lt; 0.05). Barrier function: Stimulation by TNFα (i) disturbed Zonula Occludens 1 cellular distribution and actin F distribution and (ii) significantly decreased RPE transepithelial resistance in a dose‐dependent manner (‐70, ‐88.5 and ‐90.8% of control for C2,C3 and C4, p &lt; 0.05). Immunossupressive function: 10 day pre‐stimulation with ‐TNFα significantly decreased RPE capacity to induce monocyte death after 24 h of co‐culture (p &lt; 0.05).ConclusionsChronic exposure to TNFα deteriorates major RPE functions that are essential to visual function and might play a key role in the pathophysiology of AMD.

Assessing the near threshold cross section of theO17(n,α)C14reaction by means of the Trojan horse method

The study of the $^{17}\mathrm{O}(n,\ensuremath{\alpha})^{14}\mathrm{C}$ reaction has been performed by means of the Trojan horse method (THM) applied to the quasifree $^{2}\mathrm{H}(^{17}\mathrm{O},\ensuremath{\alpha}^{14}\mathrm{C})^{1}\mathrm{H}$ reaction induced at a beam energy of 43.5 MeV. The THM allowed us to study the 8121-keV $^{18}\mathrm{O}^{*}$ resonant level, for which the previous THM investigation pointed out the ability of the method to overcome the centrifugal barrier suppression effects in the entrance channel. Here, in view of the developments of the method for resonant reactions, the detailed analysis of the performed experiment will be discussed, focusing on the extraction of the 8121-keV resonance strength for which no information is present in scientific literature. Moreover, the experimental results clearly show the excitation of the subthreshold level centered at $\ensuremath{-}6$ keV in the center-of-mass system, which is fundamental to determine the $^{17}\mathrm{O}(n,\ensuremath{\alpha})^{14}\mathrm{C}$ reaction rate of astrophysical interest. Finally, a new recommended reaction rate is presented for future astrophysical application.