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The current study focuses on the phytochemical characterization and biological activity of phenolic compounds derived from leaves of Moringa oleifera Lam. (Moringaceae) in the Tabelbala area (Bechar, Algeria). For a concentration of 1 mg/ml, the antioxidant tests revealed that the different extracts have a good reducing activity, with the tannin extract having the highest percentage of free radical inhibition (DPPH: 94%) compared to the n-butanolic extract (92%) and the ethyl acetate extract (88%). Furthermore, the tannin extract and the n-butanolic fraction of the flavonoids of the examined leaves showed significant antioxidant activity compared to ascorbic acid used as a reference (IC50 = 0.05 ± 0.14 mg/ml), with IC50 values of 0.07 ± 0.79 mg/ml for tannins and 0.0823 ± 0.25 mg/ml for the n-butanolic extract. In addition, the ferric reduction antioxidant power (FRAP) test reveals that all the tested extracts have a significant reduction power. The different selective extracts showed strong antimicrobial activity against nine pathogenic microbial strains: Escherichia coli (ATCC 25922), Pseudomonas aeruginosa (ATCC 27853), Klebsiella pneumoniae (ATCC 13883), Citrobacter freundii (ATCC 29212), Acinetobacter baumannii (ATCC 19606), Bacillus cereus (ATCC 11778), Staphylococcus aureus (ATCC 25923), Enterococus faecalis (ATCC 13045), and Candida albicans, where the ethyl acetate fraction has a higher antibacterial activity than n-butanolic and tannin extract, with the zone of inhibition diameters ranging from 11 to 23 mm and have minimum inhibitory concentrations (MIC) between 0.39 and 3.125 mg/ml. These findings give scientific support for the plant's traditional use, highlighting the value of traditional medicines in the treatment of many diseases. [ABSTRACT FROM AUTHOR]

Pronounced swelling is observed when single crystals of yttrium iron garnet Y 3 Fe 5 O 12 (YIG) are irradiated in the electronic energy loss regime with various swift heavy ions. The out-of-plane swelling was measured by scanning across the border line between an irradiated and a virgin area of the sample surface with the tip of a profilometer. The step height varied between 20 and 600 nm depending on fluence, electronic energy loss and total range of the ions. The step height divided by the ion range as a function of the ion fluence exhibits a linear increase in the initial phase and saturates at high fluences leading to a density decrease of around 1.7%. With complementary channeling-Rutherford-backscattering experiments (c-RBS), the damage fraction and the corresponding damage cross section were extracted and compared to the cross section deduced from swelling measurements. Irradiation effects were also characterized by scanning force microscopy (SFM). A threshold for damage creation as deduced from all the present physical characterizations is 5.5 ± 1.0 keV/nm. The value is in full agreement with previous measurements confirming that swelling and SFM characterizations can provide information concerning the electronic energy loss threshold for track formation. In contrast, track radii deduced from swelling measurements are smaller and radii from SFM are larger than deduced from c-RBS analysis. The results of Y 3 Fe 5 O 12 of this work are compared with data obtained for other crystalline oxides and for ionic crystals. [ABSTRACT FROM AUTHOR]

Abstract: Thermally grown amorphous SiO2 samples were implanted at room temperature (RT) with 120keV C-ions to a dose ranging from 1.0×1016 to 8.6×1017C ions/cm2, then irradiated at RT with 950MeV Pb, 345 or 1754MeV Xe ions to a fluence in the region from 1.0×1011 to 3.8×1012 ions/cm2, respectively. The irradiated samples were investigated using micro-FTIR and micro-Raman spectroscopes. It was found that new chemical bonds such as Si–C, Ce:glyph name="tbnd" />C and Si(C)–O–C bonds formed significantly in the C-doped SiO2 films after heavy ion irradiations. The evolution of Si–O–C bonds and possible mechanism of structural modification in C-doped SiO2 induced by swift heavy ion irradiations were discussed. [Copyright &y& Elsevier]

This communication deals with experimental results crucial for the sizing of picosecond LIBS measurements dedicated to the determination of tritium density profiles in the plasma facing components. Ablation properties in single pulse on aluminum (considered as a surrogate of beryllium) and tungsten have been obtained for 532 and 1064 nm picosecond laser pulses. Then, double pulse experiments have been performed to estimate the role played by the second pulse on the spectral radiance observed for lines representative of the ionization degree of the plasma and possible observation of low radiance lines. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 thin films synthesized by sol–gel on glass substrates are irradiated by 90MeV Xe ions at various fluences and room temperature under normal incidence. The structural, electrical, optical and surface topography properties before and after Xe ions irradiation are investigated. X-ray diffraction (XRD) reveals that the crystallinity is gradually destroyed, and the films become amorphous above 5×1012 ions/cm2. The band gap is not affected by Xe ions irradiation as evidenced from the optical measurements. By contrast, the conductivity increases with raising Xe fluence. The energy band diagram established from the electrochemical characterization shows the feasibility of TiO2 films for the photo-electrochemical chromate reduction. Xe ion irradiation results in enhanced photocatalytic activity in aquatic medium, evaluated by the reduction of Cr(VI) into trivalent state. TiO2 films irradiated at 1013 Xe/cm2 exhibit the highest photoactivity; 69% of chromate (10ppm) is reduced at pH ~3 after 4h of exposure to sunlight (1120mWcm−2) with a quantum yield of 0.06%. [Copyright &y& Elsevier]

TiO2 films prepared by sol–gel were irradiated with 25.8MeV Cu and 90MeV Xe ions at room temperature under normal incidence. The irradiation with Cu and Xe ions were performed respectively at iThemba labs, South Africa and GANIL, Caen, France. The properties of radiation defects induced in TiO2 nanostructures were investigated using grazing angle X-ray diffraction (GAXRD), atomic force microscopy (AFM) and UV–visible spectrophotometry. From GAXRD analysis, it is found that anatase (101) peak intensity decrease with increasing the fluence and disappear completely above a threshold ion fluence of 5×1012 ion/cm2. This indicates that the crystallinity of the TiO2 film is destroyed upon irradiation due to the amorphous track formation. The track radius estimated from the Poisson’s law is about 2 and 4nm after irradiation with 25.8MeV Cu and 90MeV Xe ions, respectively. According to the AFM analysis, the elaborated TiO2 films are composed of particles with a triangular shape of a size in the range of 200–500nm. It is found that the particle size increases after irradiation with both Cu and Xe ions. In addition, the root-mean-square (RMS) surface roughness for 780nm×780nm area scans decreases exponentially with increasing fluence up to 1013 ions/cm2 in the case of Xe irradiation, but increases drastically above 2.68×1011 ions/cm2 in the case of Cu ion irradiation and reaches a mean value of ∼3nm. The absorption measurements reveal that the optical band gap is not affected by both Xe and Cu ions irradiation. [ABSTRACT FROM AUTHOR]

The LIBS (laser-induced breakdown spectroscopy) method can be implemented to determine the multi-elemental composition of solid samples. Unfortunately, the precision of the usual LIBS configuration (single pulse) is rather low for light elements in metallic matrices. The double pulse configuration can help to overcome this difficulty. Indeed, the electron temperature and density are significantly increased by the second pulse absorbed by the plasma produced by the first pulse which leads to a higher signal-to-noise ratio. The present paper reports preliminary results in double pulse configuration on fusion-relevant materials, i.e. aluminum (considered as a beryllium surrogate) and tunsgten, in the perspective of the test of this technique to measure in situ the hydrogen isotopes concentration of the divertor and the first wall of an ITER-like tokamak. The plasma spectroscopic analysis is performed to derive the gain in electron density reached by the absorption of the second pulse. In parallel, the spectral absorptivity of the plasma regarding the second pulse is determined to correlate the electron density dynamics to the energy deposit. The absorption by the plasma of the second pulse is then quantified at the atomic and macroscopic scales. [ABSTRACT FROM AUTHOR]

The accurate identification and prioritization of antigenic peptides is crucial for the development of personalized cancer immunotherapies. Publicly available pipelines to predict clinical neoantigens do not allow direct integration of mass spectrometry immunopeptidomics data, which can uncover antigenic peptides derived from various canonical and noncanonical sources. To address this, we present an end-to-end clinical proteogenomic pipeline, called NeoDisc, that combines state-of-the-art publicly available and in-house software for immunopeptidomics, genomics and transcriptomics with in silico tools for the identification, prediction and prioritization of tumor-specific and immunogenic antigens from multiple sources, including neoantigens, viral antigens, high-confidence tumor-specific antigens and tumor-specific noncanonical antigens. We demonstrate the superiority of NeoDisc in accurately prioritizing immunogenic neoantigens over recent prioritization pipelines. We showcase the various features offered by NeoDisc that enable both rule-based and machine-learning approaches for personalized antigen discovery and neoantigen cancer vaccine design. Additionally, we demonstrate how NeoDisc's multiomics integration identifies defects in the cellular antigen presentation machinery, which influence the heterogeneous tumor antigenic landscape., (© 2024. The Author(s).)

Angstrom-confined solvents in 2D laminates can travel through interlayer spacings, through gaps between adjacent sheets, and via in-plane pores. Among these, experimental access to investigate the mass transport through in-plane pores is lacking. Our experiments allow an understanding of this mass transport via the controlled variation of oxygen functionalities, size and density of in-plane pores in graphene oxide membranes. Contrary to expectations, our transport experiments show that higher in-plane pore densities may not necessarily lead to higher water permeability. We observed that membranes with a high in-plane pore density but a low amount of oxygen functionalities exhibit a complete blockage of water. However, when water-ethanol mixtures with a weaker hydrogen network are used, these membranes show an enhanced permeation. Our combined experimental and computational results suggest that the transport mechanism is governed by the attraction of the solvents toward the pores with functional groups and hindered by the strong hydrogen network of water formed under angstrom confinement.

In this work, we have studied the pH-dependent surface charge nature of nanoporous graphene. This has been investigated by membrane potential and by streaming current measurements, both with varying pH. We observed a lowering of the membrane potential with decreasing pH for a fixed concentration gradient of potassium chloride (KCl) in the Donnan dominated regime. Interestingly, the potential reverses its sign close to pH 4. The fitted value of effective fixed ion concentration ( C̅ ) in the membrane also follows the same trend. The streaming current measurements show a similar trend with sign reversal around pH 4.2. The zeta potential data from the streaming current measurement is further analyzed using a 1-pK model. The model is used to determine a representative pK (acid-base equilibrium constant) of 4.2 for the surface of these perforated graphene membranes. In addition, we have also theoretically investigated the effect of the PET support in our membrane potential measurement using numerical simulations. Our results indicate that the concentration drop inside the PET support can be a major contributor (up to 85%) for a significant deviation of the membrane potential from the ideal Nernst potential.R ) in the membrane also follows the same trend. The streaming current measurements show a similar trend with sign reversal around pH 4.2. The zeta potential data from the streaming current measurement is further analyzed using a 1-pK model. The model is used to determine a representative pK (acid-base equilibrium constant) of 4.2 for the surface of these perforated graphene membranes. In addition, we have also theoretically investigated the effect of the PET support in our membrane potential measurement using numerical simulations. Our results indicate that the concentration drop inside the PET support can be a major contributor (up to 85%) for a significant deviation of the membrane potential from the ideal Nernst potential., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Nanoporous graphene displays salt-dependent ion permeation. In this work, we investigate the differences in Donnan potentials arising between reservoirs, separated by a perforated graphene membrane, containing different cations. We compare the case of monovalent cations interacting with nanoporous graphene with the case of bivalent cations. This is accomplished through both measurements of membrane potential arising between two salt reservoirs at different concentrations involving a single cation (ionic potential) and between two reservoirs containing different cations at the same concentration (bi-ionic potential). In our present study, Donnan dialysis experiments involve bivalent MgCl 2 , CaCl 2 , and CuCl 2 as well as monovalent KCl and NH 4 Cl salts. For all salts, except CuCl 2 , clear Donnan and diffusion potential plateaus were observed at low and high salt concentrations, respectively. Our observations show that the membrane potential scaled to the Nernst potential for bivalent cations has a lower value (≈50%) than for monovalent cations (≈72%) in the Donnan exclusion regime. This is likely due to the adsorption of these bivalent cations on monolayer graphene. For bivalent cations, the diffusion regime is reached at a lower ionic strength compared to the monovalent cations. For Mg 2+ and Ca 2+ , the membrane potential does not seem to depend upon the type of ions in the entire ionic strength range. A similar behavior is observed for the KCl and NH 4 Cl membrane potential curves. For CuCl 2 , the membrane potential curve is shifted toward lower ionic strength compared to the other two bivalent salts and the Donnan plateau is not observed at the lowest ionic strength. Bi-ionic potential measurements give further insight into the strength of specific interactions, allowing for the estimation of the relative ionic selectivities of different cations based on comparing their bi-ionic potentials. This effect of possible ion adsorption on graphene can be removed through ion exchange with monovalent salts.

Two-dimensional molybdenum-disulfide (MoS2) catalysts can achieve high catalytic activity for the hydrogen evolution reaction upon appropriate modification of their surface. The intrinsic inertness of the compound's basal planes can be overcome by either increasing the number of catalytically active edge sites or by enhancing the activity of the basal planes via a controlled creation of sulfur vacancies. Here, we report a novel method of activating the MoS2 surface using swift heavy ion irradiation. The creation of nanometer-scale structures by an ion beam, in combination with the partial sulfur depletion of the basal planes, leads to a large increase of the number of low-coordinated Mo atoms, which can form bonds with adsorbing species. This results in a decreased onset potential for hydrogen evolution, as well as in a significant enhancement of the electrochemical current density by over 160% as compared to an identical but non-irradiated MoS2 surface.

The control of surface wetting properties to produce robust and strong hydrophobic and oleophobic effects on intrinsically oleophilic surfaces is at the heart of many technological applications. In this paper, we explore the conditions to observe such effects when the roughness of the substrate is of fractal nature and consists of nanofeatures obtained by the ion track etching technique. The wetting properties were investigated using eight different liquids with surface tensions gamma varying from 18 to 72 mN m(-1). While it is observed that all the tested oils readily wet the flat substrates, it is found that the contact angles are systematically exalted on the rough surfaces even for the liquids with very low surface tension. For liquids with gamma > or = 25 mN m(-1) an oleophobic behavior is clearly induced by the nanostructuration. For liquids with gamma < 25 mN m(-1), although the contact angle is enhanced on the nanorough surfaces, it conserves its oleophilic character (theta* lower than 90 degrees). Moreover, our experiments show that even in the case of hexane, liquid having the lowest surface tension, the homogeneous wetting (Wenzel state) is never reached. This high resistance to liquid impregnation is discussed within the framework of recent approaches explaining the wetting properties of superoleophobic surfaces.