Probe Analysis Research Articles

Post-deposition annealing influences of gas adsorption on semi-vertical β-FeOOH nanorods at room temperature: A scanning kelvin probe analysis

An investigation on gas adsorption of β-FeOOH at room temperature was performed through kelvin probe analysis. The microscopic images revealed the semi vertically grown nanorods on conductive fluorine doped tin oxide (FTO) substrate prepared by hydrothermal method. The annealing temperature strongly influenced the crystallite size, lattice stress, grain size and boundaries estimated through X-ray diffraction analysis. The crystallite size increased from 57 nm to 67 nm with a proportional increase in annealing temperature from 350 °C to 450 °C. The UV absorption spectra indicated a red shift towards visible wavelength region with increasing annealing temperature elucidating a visible-light enhanced response for the activation of gas adsorption. Correspondingly, the energy band gap decreased with increasing annealing temperature. The adsorption behaviour of different types of volatile organic compounds (VOCs) were studied using scanning kelvin probe (SKP) to measure the contact potential difference (CPD) on the surface of the samples. The CPD changes for ethanol were higher (−264 mV) at lower temperatures (350 °C) and vice versa. However, an intriguing behaviour was found for other types of gases. This peculiar behaviour with respect to the annealing temperature was understood by SKP and attributed to the presence of numerous grain boundaries interfaces which were absent when annealed at low temperature due to higher crystallite size. These adsorption studies provides notion on the fundamental mechanism of gas interaction for the fabrication of selective gas sensors.

Lingguizhugan decoction protects PC12 cells against Aβ25-35-induced oxidative stress and neuroinflammation by modulating NF-κB/MAPK signaling pathways

Ethnopharmacological relevanceAlzheimer's disease (AD) is recognized as one of the most prevalent neurodegenerative diseases. Lingguizhugan decoction (LGZGD) is a classical traditional Chinese medicine (TCM). Many studies have shown that LGZGD can alleviate the symptoms of AD. Aim of the studyThe aim of this study was to assess the neuroprotective effects of LGZGD and elucidate its molecular mechanism on Aβ25-35-induced PC12 cells. Materials and methodsPC12 cells were used MTT assays, ELISA, fluorescence probe analyses, Hoechst 33342 staining, immunofluorescent staining and western blot analyses were systematically conducted to evaluate the underlying mechanisms of LGZGD. ResultsIn Aβ25-35-induced PC12 cells, LGZGD remarkably increased cell viability, reduced the generation of TNF-α, IL-1β, IL-6, MDA and ROS, increased the activity of GSH-Px, inhibited cell apoptosis, downregulated the expression of Bax and cleaved caspase-3, and upregulated the expression of Bcl-2. Moreover, LGZGD modulated the NF-κB/MAPK signaling pathways by upregulating the levels of IκBα and phospho-ERK, while downregulating the levels of phospho-p65, phospho-IκBα, and phospho-p38. Furthermore, LGZGD repressed the nuclear translocation activity of NF-κB p65. Meanwhile, LGZGD increased the expression of phospho-GSK-3β and reversed the hyperphosphorylation of Tau proteins by inhibiting the activation of the ERK MAPK pathway. ConclusionsTaken together, the present study suggested that LGZGD may be a valuable drug candidate that can attenuate the neurotoxicity induced by Aβ25-35 by modulating the NF-κB/MAPK signaling pathways in PC12 cells.

Tandem Probe Analysis Mode for Synchrotron XFM: Doubling Throughput Capacity.

Synchrotron-based X-ray fluorescence microscopy (XFM) analysis is a powerful technique that can be used to visualize elemental distributions across a broad range of sample types. Compared to conventional mapping techniques such as laser ablation inductively coupled plasma mass spectrometry or benchtop XFM, synchrotron-based XFM provides faster and more sensitive analyses. However, access to synchrotron XFM beamlines is highly competitive, and as a result, these beamlines are often oversubscribed. Therefore, XFM experiments that require many large samples to be scanned can penalize beamline throughput. Our study was largely driven by the need to scan large gels (170 cm2) using XFM without decreasing beamline throughput. We describe a novel approach for acquiring two sets of XFM data using two fluorescence detectors in tandem; essentially performing two separate experiments simultaneously. We measured the effects of tandem scanning on beam quality by analyzing a range of contrasting samples downstream while simultaneously scanning different gel materials upstream. The upstream gels were thin (<200 μm) diffusive gradients in thin-film (DGT) binding gels. DGTs are passive samplers that are deployed in water, soil, and sediment to measure the concentration and distribution of potentially bioavailable nutrients and contaminants. When deployed on soil, DGTs are typically small (2.5 cm2), so we developed large DGTs (170 cm2), which can be used to provide extensive maps to visualize the diffusion of fertilizers in soil. Of the DGT gel materials tested (bis-acrylamide, polyacrylamide, and polyurethane), polyurethane gels were most suitable for XFM analysis, having favorable handling, drying, and analytical properties. This gel type enabled quantitative (>99%) transmittance with minimal (<3%) flux variation during raster scanning, whereas the other gels had a substantial effect on the beam focus. For the first time, we have (1) used XFM for mapping analytes in large DGTs and (2) developed a tandem probe analysis mode for synchrotron-based XFM, effectively doubling throughput. The novel tandem probe analysis mode described here is of broad applicability across many XFM beamlines as it could be used for future experiments where any uniform, highly transmissive sample could be analyzed upstream in the “background” of downstream samples.

Millennial pulses of ore formation and an extra-high Tibetan Plateau

Abstract Quantifying the rhythms and rates of magmatic-hydrothermal systems is critical for a better understanding of their controls on ore formation and the dynamics of magmatic reservoirs that feed them. We reconstructed the evolution of ore-forming fluids using hydrothermal quartz from the 17.4 Ma Zhibula skarn, Tibet. Ion probe analysis reveals sharp and dramatic changes in quartz δ18O values between 5‰ and −9.3‰, with fluid δ18O values varying between 2.8‰ and −18.2‰, which are best explained by transient meteoric water incursion into a hydrothermal system dominated by magmatic fluids. Two pulses of magmatic fluids and a meteoric water incursion event are inferred, which operated at the millennium scale (760−1510 yr) as constrained by the aluminum diffusion chronometer. Our results indicate that magmatic reservoirs are likely water unsaturated for most of their lifetime (&amp;gt;105−106 yr), with transient and episodic fluid exsolutions (~103 yr) being driven by magma replenishment or crystallization-induced water saturation. With focused and efficient metal deposition, multiple pulses of metalliferous fluids favor the formation of giant deposits with high grade. Meteoric water δ18O values (−25.4 ± 2.3‰) derived from Zhibula quartz further suggest a paleo-elevation of 5.9 ± 0.3 km; this transient early Miocene surface uplift plausibly was due to break-off of the oceanic slab attached to the Indian Plate. Our research highlights that ubiquitous hydrothermal quartz in orogenic belts can probe the dynamics of magmatic-hydrothermal systems and also quantify paleo-elevations, which has significant tectonic implications.

Smooth muscle Rac1 contributes to pulmonary hypertension.

Background and PurposePulmonary hypertension (PH) is a multifactorial chronic disease characterized by an increase in pulmonary artery (PA) resistance leading to right ventricle (RV) failure. Endothelial dysfunction and alteration of NO/cGMP signalling in PA plays a major role in PH. We recently described the involvement of the Rho protein Rac1 in the control of systemic blood pressure through its involvement in NO‐mediated relaxation of arterial smooth muscle cell (SMC). The aim of this study was to analyse the role of SMC Rac1 in PH.Experimental ApproachPH is induced by exposure of control and SMC Rac1‐deficient (SM‐Rac1‐KO) mice to chronic hypoxia (10% O2, 4 weeks). PH is assessed by the measurement of RV systolic pressure and hypertrophy. PA reactivity is analysed by isometric tension measurements. PA remodelling is quantified by immunofluorescence in lung sections and ROS are detected using the dihydroethidium probe and electronic paramagnetic resonance analysis. Rac1 activity is determined by immunofluorescence.Key ResultsRac1 activation in PA of hypoxic mice and patients with idiopathic PH. Hypoxia‐induced rise in RV systolic pressure, RV hypertrophy and loss of endothelium‐dependent relaxation were significantly decreased in SM‐Rac1‐KO mice compared to control mice. SMC Rac1 deletion also limited hypoxia‐induced PA remodelling and ROS production in pulmonary artery smooth muscle cells (PASMCs).Conclusion and ImplicationsOur results provide evidence for a protective effect of SM Rac1 deletion against hypoxic PH. Rac1 activity in PASMCs plays a causal role in PH by favouring ROS‐dependent PA remodelling and endothelial dysfunction induced by chronic hypoxia.

Genesis of the Gaolong gold deposit in Northwest Guangxi Province, South China: Insights from in situ trace elements and sulfur isotopes of pyrite

The Guangxi-Yunnan-Guizhou district, also named Dian-Qian-Gui “Golden Triangle”, in Southwest China has a large amount of Carlin-type Au deposits. Gaolong is one source of Carlin-type Au deposit in the northwestern Guangxi Province. Pyrites are the major Au-bearing sulfides. Majority of Au are structurally bound Au+, with a few nanoparticles (Au0) occurring in the sulfides. In this study, in situ chemical and S isotopes of pyrites in the Gaolong Au deposit were analyzed by laser ablation inductively-coupled plasma mass spectrometry and laser ablation multi-collector inductively-coupled plasma mass spectrometry, respectively. Backscattered electron (BSE) images and chemical composition analysis showed that the pyrites were divided into four main types: (1) As-poor Py1 (pre-ore sedimentary or diagenetic stage, with prominent spotted and aggregate structures. These are fine-grained pyrite aggregates with rough surfaces and low brightness under the BSE, with edges often eroded by hydrothermal fluid); (2) As-weak Py2 (early ore stage, the core of the rim pyrite, with good crystallization and characteristic corrosion spots in the particle, and with the edge dissolved to show irregular structure); (3) As-rich Py3 (main ore stage, the narrow pyrite rims overgrowing Py1 and Py2, irregularly-shaped and less than 50 μm in width); and (4) As-rich Py4 (fine-grained pyrite, with good crystallization, high brightness, and symbiotic with Py3 and Py1, or an isolated distribution). Py1 contains higher concentrations of S, Fe, and W, and lower Co/Ni ratios (average of 0.91), suggesting a pre-ore origin. The ore-stage pyrites Py2, Py3, and Py4, have elevated mineralization elements—Au of 0.25–72 ppm, As of 2214–40613 ppm, Tl of 0.95–109 ppm, Sb of 31.16–1851 ppm, Cu of 49.09–910 ppm, with average Co/Ni ratios of 0.43. Au was positively correlated with As, Tl, Cu, and Ni in these pyrites. Electron micro probe analyzer (EMPA) elemental mappings show that: 1) Py1 has a low Au content, while Py2, Py3, and Py4 have high Au, As, Cu, Ti, and Mg contents; 2) Au occurs in As-rich pyrite in the form of invisible gold; 3) Rim pyrite contains high concentrations of Cu, which has a good positive correlation with As, while As and Au are decoupled on a smaller scale. The Au contents and Au/As ratios show that the Au-carrying fluids are unsaturated with Au. In situ S isotopes show that the δ34S values range from 10.19‰ to 13.79‰ with a mean value of 12.07‰ for Py1, 8.60‰ to 10.78‰ with a mean value of 9.77‰ for Py2, 1.42‰ to 8.29‰ with a mean value of 6.81‰ for Py3, and − 0.49‰ to 4.42‰ with a mean value of 1.67‰ for Py4. The δ34S data decreased from Py1 to Py4, whereas the As content increased significantly. This indicates that Au and As are enriched in ore-forming fluids, and the ore-forming fluids have low S isotope values. Based on a comprehensive study of geological and geochemical data, we believe that the magmatic hydrothermal genetic model can explain the genesis of the Gaolong gold deposit. We conclude that the S isotope of pyrites resulted from the mixing of magmatic S and sedimentary S, and the Au-bearing fluid came from deep-concealed granite, establishing a magma genesis of the Gaolong Au deposit.

Alpha–Proton Differential Flow of the Young Solar Wind: Parker Solar Probe Observations

Abstract The velocity of alpha particles relative to protons can vary depending on the solar wind type and distance from the Sun. Measurements from the previous spacecraft provided the alpha–proton differential velocities down to 0.3 au. The Parker Solar Probe (PSP) now enables insights into differential flows of the newly accelerated solar wind closer to the Sun for the first time. Here we study the difference between proton and alpha bulk velocities near PSP perihelia of encounters 3–7 when the core solar wind is in the field of view of the Solar Probe Analyzer for Ions instrument. As previously reported at larger heliospheric distances, the alpha–proton differential speed observed by PSP is greater for fast wind than the slow solar wind. We compare PSP observations with various spacecraft measurements and present the radial and temporal evolution of the alpha–proton differential speed. The differential flow decreases as the solar wind propagates from the Sun, consistent with previous observations. While Helios showed a small radial dependence of differential flow for the slow solar wind, PSP clearly showed this dependency for the young slow solar wind down to 0.09 au. Our analysis shows that the alpha–proton differential speed’s magnitude is mainly below the local Alfvén speed. Moreover, alpha particles usually move faster than protons close to the Sun. The PSP crossed the Alfvén surface during its eighth encounter and may cross it in future encounters, enabling us to investigate the differential flow very close to the solar wind acceleration source region for the first time.

Effect of non-rubber components on the crosslinking structure and thermo-oxidative degradation of natural rubber

Non-rubber components (NRCs) in natural rubber (NR), including proteins, phospholipids, fatty acids, etc., determine to a large extent the structure and properties of NR. In this study, the effects of NRCs on the network structure and thermo-oxidative aging behavior of unvulcanized and vulcanized NR were investigated. NRCs were found to form physically crosslinked networks in the unvulcanized NR and acted as a natural antioxidant to scavenge free radicals, which contributed to improved thermo-oxidative stability of the unvulcanized NR. Swell analysis, chemical probe analysis (DPPH), and XPS results showed that the NRCs accelerated the vulcanization reaction and increased the crosslink density, and promoted the formation of more mono- and disulfide bonds during vulcanization. When aged at high temperatures, more monosulfide bonds were formed in the vulcanized rubber with high contents of NRCs by cleaving and rearranging the poly- and disulfide bonds. NRCs were also found to increase the activation energy of thermal degradation and led to the better mechanical stability of vulcanized NR against thermal oxidation.

Scanning probe analysis of twisted graphene grown on a graphene/silicon carbide template

Overlayer growth of graphene on an epitaxial graphene/silicon carbide (SiC) as a solid template by ethanol chemical vapor deposition is performed over a wide growth temperature range from 900 °C to 1450 °C. Structural analysis using atomic force and scanning tunneling microscopies reveal that graphene islands grown at 1300 °C form hexagonal twisted bilayer graphene as a single crystal. When the growth temperature exceeds 1400 °C, the grown graphene islands show a circular shape. Moreover, moiré patterns with different periods are observed in a single graphene island. This means that the graphene islands grown at high temperature are composed of several graphene domains with different twist angles. From these results, we conclude that graphene overlayer growth on the epitaxial graphene/SiC solid at 1300 °C effectively synthesizes the twisted few-layer graphene with a high crystallinity.

Gum-based nanocapsules comprising naphthoquinones enhance the apoptotic and trypanocidal activity against Trypanosoma evansi

Nanoencapsulation is a promising approach to enhance the therapeutic potential of a drug. Herein, three selected naphthoquinone (NTQ) derivatives, based on the IC50 value against Trypanosoma evansi, were encapsulated using gum damar as biocompatible and biodegradable natural gum via nanoprecipitation method. Nanoformulation of NTQs (NNTQs) was less than 150 nm in size, was found to be stable and released the drug in a sustained manner. All the three NNTQs exhibited significant antitrypanosomal effect and morphological changes at approximately two to three times lesser drug concentrations. The nanoformulations exhibited enhanced production of reactive oxygen species (ROS) in the axenic culture of T. evansi and less cytotoxic effect on horse peripheral blood mononuclear cells relative to pure NTQs. As evidenced by flow cytometry, the NNTQs showed dose-dependent and time-dependent increased transition of live cells (AV-PI-) to early apoptotic cells (AV+PI−), late apoptotic cells (AV−PI+), and necrotic cells (AV+PI+) using annexin V/propidium iodide probe analysis. The results concluded that NNTQs induced more ROS, apoptosis and necrotic effects that exhibited more inhibitory effect on the growth of T. evansi with respect to respective NTQ by themselves.

EPMA and PIXE Analyses of High Grade Metamorphic Rocks

Background/Objectives: The demand for exact quantification analyses in complex ore assemblages is increasing rapidly as mineral processing studies become more sophisticated. In response to this need, an Electron Micro Probe Analysis and Proton Induced X-ray Emission complementary based analytical tool procedure for the chemical characterization of minerals was employed to study the metamorphic rocks. Methods : In this work, we compare the quantitative analysis of high-grade metamorphic rocks by proton induced X-ray emission (PIXE) with that of the previous analyses by electron probe microanalysis (EPMA). During this investigation, the PIXE analytical method on a nuclear microprobe was added to the previously well-known EPMA for the chemical quantification of high-grade metamorphic rocks from the Charnockite Hill, Visakhapatnam, A.P., India. For the evolution and geochemical characterization of the metamorphic rocks, the above two methods are compared and discussions are made with respect to certain elements. Findings: Particle-induced X-ray emission is well-matched except for certain elements for the chemical characterization of metamorphic rocks belonging to earth material samples. This comparison with EPMA demonstrates the elemental quantification characteristics for such analyses. Not only is an exploratory study of proton induced X-ray emission benefit presented, but also a synopsis of comparison with electron probe microanalysis aimed at a responsible reply to metamorphic rock analytical questions. Novelty: The complementary technique, especially EPMA, is required to fill the elemental gaps that are not determined in the case of matrix complex charnockite compositional analysis by PIXE with 3MeV and a Si (Li) detector. Keywords: Electron and Proton Microprobes; Complementary Techniques; Metamorphic Rocks; Elemental Analysis

LMMS reloaded: Transformer-based sense embeddings for disambiguation and beyond

Distributional semantics based on neural approaches is a cornerstone of Natural Language Processing, with surprising connections to human meaning representation as well. Recent Transformer-based Language Models have proven capable of producing contextual word representations that reliably convey sense-specific information, simply as a product of self-supervision. Prior work has shown that these contextual representations can be used to accurately represent large sense inventories as sense embeddings, to the extent that a distance-based solution to Word Sense Disambiguation (WSD) tasks outperforms models trained specifically for the task. Still, there remains much to understand on how to use these Neural Language Models (NLMs) to produce sense embeddings that can better harness each NLM's meaning representation abilities. In this work we introduce a more principled approach to leverage information from all layers of NLMs, informed by a probing analysis on 14 NLM variants. We also emphasize the versatility of these sense embeddings in contrast to task-specific models, applying them on several sense-related tasks, besides WSD, while demonstrating improved performance using our proposed approach over prior work focused on sense embeddings. Finally, we discuss unexpected findings regarding layer and model performance variations, and potential applications for downstream tasks.

Ionospheric TEC and plasma anomalies possibly associated with the 14 July 2019 &lt;i&gt;M&lt;sub&gt;w&lt;/sub&gt;&lt;/i&gt;7.2 Indonesia Laiwui earthquake, from analysis of GPS and CSES data

This study presents signatures of seismo-ionospheric perturbations possibly related to the 14 July 2019 <inline-formula><tex-math id="M2">\begin{document}$ {M}_{w} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M2.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M2.png"/></alternatives></inline-formula>7.2 Laiwui earthquake, detected by a cross-validation analysis of total electron content (TEC) data of the global ionospheric map (GIM) from GPS and plasma parameter data recorded by the China Seismo-Electromagnetic Satellite (CSES). After separating pre-seismic ionospheric phenomena from the ionospheric disturbances due to the magnetospheric and solar activities, we have identified three positive temporal anomalies, around the epicenter, at 1 day, 3 days and 8 days before the earthquake (14 July 2019), along with a negative anomaly 6 days after the earthquake. These results agree well with the TEC spatial variations in latitude–longitude–time (LLT) maps. To confirm these anomalies further, we employed the moving mean method (MMM) to analyze ionospheric plasma parameters (electron, <inline-formula><tex-math id="M3">\begin{document}$ {\mathrm{O}}^{+} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M3.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M3.png"/></alternatives></inline-formula>and <inline-formula><tex-math id="M4">\begin{document}$ {\mathrm{H}\mathrm{e}}^{+} $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M4.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M4.png"/></alternatives></inline-formula>densities) recorded by the Langmuir probe (LAP) and Plasma Analyzer Package (PAP) onboard the CSES. The analysis detected on, on Day Two, Day Four, and Day Seven before the earthquake, remarkable enhancements along the orbits around when in proximity to the epicenter. To make the investigations still more convincing, we compared the orbits on which anomalous readings were recorded to their corresponding four nearest revisiting orbits; the comparison did indeed indicate the existence of plasma parameter anomalies that appear to be associated with the Laiwui earthquake. All these results illustrate that the unusual ionospheric perturbations detected through GPS and CSES data are possibly associated with the <inline-formula><tex-math id="M5">\begin{document}$ {M}_{w}7.2 $\end{document}</tex-math><alternatives><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M5.jpg"/><graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="RA305-wenyuanzheng-F_M5.png"/></alternatives></inline-formula> Laiwui earthquake, which suggests that at least some earthquakes may be predicted by alertness to pre-seismic ionospheric anomalies over regions known to be at seismic risk. This case study also contributes additional information of value to our understanding of lithosphere–atmosphere–ionosphere coupling.

Resistive MHD modes in hollow cathodes external plasma

A significant number of plasma instabilities occur in the region just outside of hollow cathodes, depending on the injected gas flow, the current level and the application of an external magnetic field. In particular, the presence of an axial magnetic field induces a helical mode, affecting all the plasma parameters and the total current transported by the plasma. To explore the onset and behavior of this helical mode, the fluctuations in the plasma parameters in the current-carrying plume outside of a hollow cathode discharge have been investigated. The hollow cathode was operated at a current of 25 A, and at variable levels of propellant flow rate and applied magnetic fields. Electromagnetic probes were used to measure the electromagnetic fluctuations, and correlation analysis between each of the probe signals provided spatial-temporal characterization of the generated waves. Time-averaged plasma parameters, such as plasma potential and ion energy distribution function, were also collected in the near-cathode plume region by means of scanning emissive probe and retarding potential analyzer. The results show that the helical mode exists in the cathode plume at sufficiently high applied magnetic field, and is characterized by the presence of a finite electromagnetic component in the axial direction, detectable at discharge currents ⩾25 A. A theoretical analysis of this mode reveals that one possible explanation is consistent with the hypotheses of resistive magnetohydrodynamics, which predicts the presence of helical modes in the forms of resistive kink. The analysis has been carried out by linear perturbation of the resistive MHD equations, from which it is possible to obtain the dispersion relation of the mode and find the k–ω unstable branch associated with the instability. These findings provided the basis for more detailed investigation of resistive MHD modes and their effect in the plume of hollow cathodes developed for electric propulsion application.

Chemical and elemental mapping of spent nuclear fuel sections by soft X-ray spectromicroscopy.

Soft X-ray spectromicroscopy at the O K-edge, U N4,5-edges and Ce M4,5-edges has been performed on focused ion beam sections of spent nuclear fuel for the first time, yielding chemical information on the sub-micrometer scale. To analyze these data, a modification to non-negative matrix factorization (NMF) was developed, in which the data are no longer required to be non-negative, but the non-negativity of the spectral components and fit coefficients is largely preserved. The modified NMF method was utilized at the O K-edge to distinguish between two components, one present in the bulk of the sample similar to UO2 and one present at the interface of the sample which is a hyperstoichiometric UO2+x species. The species maps are consistent with a model of a thin layer of UO2+x over the entire sample, which is likely explained by oxidation after focused ion beam (FIB) sectioning. In addition to the uranium oxide bulk of the sample, Ce measurements were also performed to investigate the oxidation state of that fission product, which is the subject of considerable interest. Analysis of the Ce spectra shows that Ce is in a predominantly trivalent state, with a possible contribution from tetravalent Ce. Atom probe analysis was performed to provide confirmation of the presence and localization of Ce in thespent fuel.

ANALYSIS OF THE EFFECTIVENESS OF DIFFERENT TREATMENT REGIMENS FOR DRUG-RESISTANT TUBERCULOSIS IN PRYKARPATTIA. CHALLENGES OF OUR TIME

The aim: To study the structure of adverse drug reactions and the effectiveness of treatment among patients with drug-resistant tuberculosis who follow the modified short-term and individualized treatment regimens. Materials and methods: The analysis of 138 inpatient medical records, outpatient health cards and electronic database of the patient register was conducted. Resistant strains of MTB were microbiologically verified in all the patients. All the patients underwent clinical-laboratory, instrumental microbiological, genetic-molecular (GeneXpert MTB / RIF) methods of examination, both for diagnosis and monitoring of the effectiveness of treatment. In order to prevent complications and control adverse reactions, all the patients were briefly screened for peripheral neuropathy, basic audiometry, the QTc interval was determined, visual acuity and color perception were checked. Results: At individualized treatment regimen of tuberculosis, adverse reactions were 3.5 times more common than in patients with modified short-term therapy, in 65 (68.4%) cases and in 8 (18.6%) cases, respectively. Accordingly, the effectiveness of treatment differed in both groups. Prevailing in long-term treatment were: treatment interruption treatment gap, treatment failure, continued treatment. In patients receiving short-term regimens, the cured rate was almost twice as common as in the second group. Conclusions: Timely detection cases of resistant tuberculosis and using linear probe analysis (LPA) - GenoType MTBDRplus for diagnosis of fluoroquinolone resistance, will allow the use of modified short-term treatment regimens for tuberculosis. Which in turn will reduce the number of side effects and improve the outcome of treatment.

Atom probe analysis of electrode materials for Li-ion batteries: challenges and ways forward.

The worldwide development of electric vehicles as well as large-scale or grid-scale energy storage to compensate for the intermittent nature of renewable energy generation has led to a surge of interest in battery technology. Understanding the factors controlling battery capacity and, critically, their degradation mechanisms to ensure long-term, sustainable and safe operation requires detailed knowledge of their microstructure and chemistry, and their evolution under operating conditions, on the nanoscale. Atom probe tomography (APT) provides compositional mapping of materials in three dimensions with sub-nanometre resolution, and is poised to play a key role in battery research. However, APT is underpinned by an intense electric field that can drive lithium migration, and many battery materials are reactive oxides, requiring careful handling and sample transfer. Here, we report on the analysis of both anode and cathode materials and show that electric-field driven migration can be suppressed by using shielding by embedding powder particles in a metallic matrix or by using a thin conducting surface layer. We demonstrate that for a typical cathode material, cryogenic specimen preparation and transport under ultra-high vacuum leads to major delithiation of the specimen during the analysis. In contrast, the transport of specimens through air enables the analysis of the material. Finally, we discuss the possible physical underpinnings and discuss ways forward to enable shielding from the electric field, which helps address the challenges inherent to the APT analysis of battery materials.

Clinical Impact of KIR2DS3 and KIR2DL3 Genes in Neuroblastoma Patients

Objective: Neuroblastoma is a common fatal tumor of childhood. Natural killer (NK) cells can exert direct cytotoxicity on tumor cells. The killer immunoglobulin-like receptor (KIR) family of NK cell receptors is involved in activation/inhibition of NK cells. In the KIR gene cluster, six of them (3DS1, 2DS1–5) encode receptors triggering activation, while seven of them (3DL1–3, 2DL1–3, 2DL5) encode receptors triggering inhibition. We aimed to assess the distribution of genetic polymorphisms of KIRs on the clinical course of neuroblastoma and provide guidance on potential therapeutic options. Methods: Our study group included 50 neuroblastoma patients and 100 healthy children as controls. Twenty-eight patients were boys, and twenty-two were girls; median age was 36 months. Fourteen patients had stage 1, 2, 3, or 4S disease, and 36 patients had stage 4 disease. Isolated DNA from the peripheral blood was amplified for sequence-specific oligonucleotide probe analysis of 16 KIR genes. The Fisher’s exact test was used to evaluate the variation of KIR gene distribution. Results: All patients had a lower frequency of KIR2DS3 compared to the control group (p = 0.005). Evaluation of individual KIR genes/genotypes in patients with early stages (stage 1, 2, 3, and 4S) versus stage 4 disease revealed that the frequency of KIR2DS3 was increased in early stages (p = 0.023). Inhibitory KIR2DL3 was increased in the patient group compared to controls (p = 0.038). Furthermore, the frequency of KIR2DL3 was higher in stage 4 neuroblastoma patients compared to the patients with early stages (p = 0.023). Conclusion: Our data suggest a role for KIR2DS3 and KIR2DL3 in development of neuroblastoma. Thus, modulation of KIR2SD3 and/or KIR2DL3 expression or function might present a novel therapeutic strategy for neuroblastoma.

Hydrothermal Alteration and Its Superimposed Enrichment for Qianjiadian Tabular-Type Uranium Deposit in Southwestern Songliao Basin

The evolution characteristics of hydrothermal activity and superimposed uranium mineralization in the Qianjiadian ore field in southwestern Songliao Basin are still controversial and lack direct evidence. In this comprehensive study, a detailed identification of dolerite and hydrothermally altered un-mineralized sandstone and sandstone-hosted ore in the Yaojia Formation have been performed through the use of scanning electron microscopy observation, electron probe, carbon-oxygen-sulfur isotope, and fluid inclusion analyses. The results show that the hydrothermal fluid derived from the intermediate-basic magma intrusion is a low-temperature reducing alkaline fluid and rich in CO2, Si, Zr, Ti, Fe, Mg, Mn, and Ca, producing different types of altered mineral assemblages in the rocks, including carbonation, pyritization, sphalerite mineralization, clausthalite mineralization, silicification, and biotitization. Specifically, the carbonate minerals in sandstone are mixed products of deep hydrothermal fluid and meteoric water, with carbon and oxygen isotopes ranging from −5.2‰ to −1.7‰ and −20.4‰ to −11.1‰, respectively. Carbon source of the carbonate minerals in dolerite is mainly inorganic carbon produced at the late stage of intermediate-basic magma evolution, with carbon and oxygen isotopes from −16.1‰ to −7.2‰ and −18.2‰ to −14.5‰, respectively. Various carbonate minerals in the rocks may have been precipitated by the hydrothermal fluid after the magmatic stage, due to the change of its CO2 fugacity, temperature, and cation concentration during the long-term evolution stage. A series of carbonate minerals were generated as calcite, dolomite, ankerite, ferromanganese dolomite, and dawsonite. The precipitation processes and different types of carbonate mineral mixtures identified in this study mainly occur as parallel, gradual transition, interlacing, or inclusion metasomatism in the same vein body, without obvious mineralogical and petrologic characteristics of penetrating relationship. Homogenization temperature of fluid inclusions in calcite is high, in the range of 203–234 °C, with a low salinity of 0.71–4.34% NaCl, and the data range is relatively concentrated. Homogenization temperature of fluid inclusions in ankerite is usually low, ranging from 100 °C to 232 °C, with a high salinity of 4.18–9.98% NaCl. The precipitation processes of carbonate minerals and the results of this study are basically in consistent. Overall, the sandstone-type uranium deposits have a temporal and genetic relationship with hydrothermal activities during Paleogene. (1) Hydrothermal activity was directly involved in uranium mineralization, result in dissolution and reprecipitation of earlier uranium minerals, forming uranium-bearing ankerite and complexes containing uranium, zirconium, silicon, and titanium. (2) Hydrothermal fluid activity provided reducing agent to promote hydrocarbon generation from pyrolysis of carbonaceous fragments and accelerate uranium precipitation rate. (3) Regional water stagnation prolongs reaction time, contributing to huge uranium enrichment. This study provides new petrologic, mineralogical, and geochemical evidence for multi-fluid coupled and superimposed mineralization of sandstone-hosted uranium deposits in the sedimentary basin.

Effect of phospholipid/flaxseed oil ratio on characteristics, structure change, and storage stability of liposomes

The flaxseed oil, a rich source of α-linolenic acid, was loaded in liposomes. The vesicle characteristics, encapsulation efficiency, and loading content with different amounts of flaxseed oil addition were investigated. At the ratio of phospholipid to flaxseed oil 5:1, the liposomes displayed an almost spherical shape and a homogeneous size distribution (observed by transmission electron microscopy and atomic force microscopy), with an average particle size 156 nm and an encapsulation efficiency of approximately 85%. The addition of flaxseed oil could change the phospholipid arrangement by Fourier-transform infrared spectroscopy and Raman spectra. The hydrophobicity of membrane surface and the micropolarity of the bilayer interior decreased with the incorporation of flaxseed oil by fluorescence probe analysis. Liposomes showed higher oxidative stability and retention rate during the storage at the ratio of 5:1. In addition, the encapsulation of flaxseed oil in liposomes showed the ability of slower release. It comprehensively illustrated the flaxseed oil could affect the membrane structure of liposomes and provided useful information regarding the preparation of liposomes for hydrophobic compounds.