Academic literature on the topic 'LA-ICP-PS'

ArgumentThe study examines the trajectory of Uruguayan Political Science (PS) from a critical theory perspective. Concretely, the article focuses on PS’ institutional birth and early period (1980s and 1990s) and shows how broader political and ideological transformations had a significant impact on its discourse on Uruguayan democracy. Three components of such discourse are unpacked: The embrace of liberalism, the rejection of Marxism, and the uncritical engagement with the local political system, particularly the ‘traditional parties.’ The argument is supported by a systematic analysis of the 163 articles published by Revista Uruguaya de Ciencia Política (RUCP) from 1987 to 2012 and 22 in-depth interviews with scholars from the Instituto de Ciencia Política (ICP) at Universidad de la República (UdelaR).

En la presente investigación presentamos un composito de polisiloxano funcionalizado con nanopartículas de plata (NPs-Ag). Se sintetizó NPs-Ag, por reducción de una solución de nitrato de plata (AgNO3) con borohidruro de sodio (NaBH4), las NPs-Ag se caracterizaron por el método espectrofotométrico UV-visible, encontrando que entre 400 – 410 nm se formó el típico pico de las NPs-Ag por la resonancia de plasmón superficial. En el análisis por Dispersión de Luz Dinámica (DLS) de las NPs-Ag se encontró una distribución polidispersa con dos poblaciones de 59,78 nm en un 70 % y de 4,33 nm en un 30%. Seguidamente, se sintetizó el gel de polisiloxano por hidrolización de clorosilano, usando como disolvente éter dietílico, el polisiloxano obtenido se caracterizó por espectrofotometría infrarroja con transformada de Fourier (FTIR). En el espectro se observan picos en la región de 1258,88 cm-1 correspondientes al metilo, entre 1000 - 1100 cm-1 un pico correspondiente al enlace Si- O-Si y una banda a 792,10 cm-1 característica de los siloxanos, confirmándose la presencia del polisiloxano. Se funcionalizó el gel de polisiloxano (PS) con NPs-Ag, obteniéndose un gel de color amarillo lechoso, debido a la absorción por resonancia de los plasmones superficiales. El análisis por DLS del gel de PS-NPs-Ag, mostró una distribución monodispersa con un tamaño promedio de 158,7 nm en un 100 %, debido a que el gel incluye en su estructura las NPs-Ag. Se caracterizó el gel de PS-NPs-Ag por FTIR observándose un pico entre 1000 y 1100 cm-1 correspondiente al Si-O-Si y una banda a 803,33 cm-1 propia de los siloxanos; asimismo, se observa una banda de absorción a 3384 cm-1 correspondiente a las NPs-Ag. En el análisis termogravimétrico (TGA) del gel de PS-NPs-Ag se muestra que a la temperatura de 374,96°C alcanza el punto de fusión, característico de un polisiloxano y a 630,22 °C la muestra se descompone. Mediante Espectrometría de Masas con Plasma Acoplado Inductivamente (ICP-MS) se encontró una concentración de plata de 5,2 ppm. Por SEM-EDX se observa la morfología típica del gel de PS-NPs-Ag, además se observa una señal que corresponde a la presencia de plata.

Abstract A double focusing ICP-MS with pulsed laser deposition (PLD) of thin films as sampling tool has been used in simulated spent fuels for a quick measurement on burn-up of nuclear reactor fuels by measuring the atom ratio of U (representing total heavy elements of mass >225) to selected lanthanide fission monitors. A linear correlation is established between the measured intensity ratios of 238U/143Nd, 238U/(145Nd+146Nd) and 238U/139La against the actual atom ratios present in the samples. The samples in the form of solution are obtained by dissolving different concentrations of U, Nd and La in nitric acid medium, representing a wide burn-up range (0.19 to 19.98 at.%). In addition, PLD films were deposited using 1064 nm, 100 ps Nd:YAG laser pulses on solid targets of U and Nd mixed oxide, corresponding to different burn-ups. ICP-MS analysis of these films after dissolving in nitric acid showed values close to that of the solid target composition. Burn-up data obtained with films deposited at a high laser power density of 1.67×1011 W/cm2 agrees well with the values of the respective target compositions compared to the films deposited at 3.3×109 W/cm2. Present analytical method requires only a very small sample quantity, typically a few nanograms and generally does not require any chemical separation in comparison to the conventional mass spectrometry method, which is traditionally employed to determine the burn-up of a nuclear fuel.

BackgroundOral squamous cell carcinomas (OSCC) prognosis remains poor. While AJCC TNM 8th edition has slightly improved patients‘ stratification with regard to prognostic, innovative approaches to are still needed. As in other tumor types, tumor immune microenvironment (TiME) might represent an opportunity to improve prognostic assessment.MethodsTiME landscape of 47 HPV-negative OSCC was analyzed using multiplex immunofluorescence (mIF). Markers for tumor cells (PanCK), tumor infiltrating lymphocytes (CD3, CD8), macrophages (CD68), inhibitory (PD-1, PD-L1, TIM3, LAG3, VISTA) or stimulatory (OX40, ICOS) immune checkpoints (ICP) were studied. Regions of interest (ROI), 5 in the tumor core and 5 at the invasion front, were subjected to cell markers identification and quantification (scoring) as well as tissue compartmentalization to divide them in tumor-epithelial and tumor-stroma compartments, respectively. A total of 20 cell phenotypes were defined based on previous work (CK+, CK+PD-L1+, CD3+, CD3+CD8+, CD3+PD-1+, CD3+CD8+PD-1+, CD3+PD-L1+, CD3+CD8+PD-L1+, CD3+PD-L1+PD-1+, CD3+CD8+PD-L1+PD-1+, CD68+, CD68+PD-L1+, CK+OX40+, CD3+VISTA+, CD3+ICOS+, CD3+LAG3+, CD3+OX-40+, CD3+TIM3+). Results were correlated with clinical features including disease-specific survival (DSS) using the Kaplan-Meier method and a multivariate Cox model. A multivariate general linear model (GLM) was built to test the specific association of each variable with a given cell density by correcting the possible confusion due to other variables.ResultsImmune cells densities were significantly higher overall in the stroma. The intra-tumor stroma showed a significant enrichment of in CD3+PD-1+ T cells compared to peri-tumor stroma. None of the clinical or pathological (resection margin, tumor stage, lymph node invasion, perineural invasion) was significantly associated with DSS. In contrast, the following cell phenotypes in the tumor invasion front were strongly associated with a poor DSS, including CD3+PD-L1+ (P-value= 0.004), CD3+PD1+PD-L1+ (P-value= 0.02) and CD3+OX40+ (P-value= 0.02) T cells as well as CD3+CD8+PD-1+ (P-value= 0.048), CD3+CD8+PD-L1+ (P-value= 0.008) and CD3+CD8+PD1+PD-L1+ (P-value= 0.01) cytotoxic T cells. In the tumor core, CD68+PD-L1- macrophages (P-value= 0.06) were marginally associated with better DSS. Using a GLM, we found that tumor from smoker-drinker patients and/or with pN+, were significantly more infiltrated by PD-1- and/or PD-L1-positive immune cells. On the other hand, floor of mouth and gingiva-mandibular OSCC were significantly less infiltrated than others.ConclusionsThe prognostic value of PD-1+ and/or PD-L1+ cells in the invasion front of resected OSCC was remarkable, underlying the importance of this area when studying the TiME. Incorporating TiME analysis in the invasion front may improve prognostic evaluation of patients treated for OSCC, especially in the context of immunotherapy.AcknowledgementsThis study was supported by a strategic alliance between the Translational Molecular Pathology-Immunoprofiling las (TMP-IL) at the Department Translational Molecular Pathology, the University of Texas MD Anderson Cancer Center and the Université Claude Bernard Lyon, Centre de Recherche en Cancérologie de Lyon and the Department of Translational Medicine, Centre Léon Bérard, Lyon, France. The authors would acknowledge ITMO Cancer 2020, ”Formation à la Recherche Fondamentale et Translationnelle en Cancérologie” (JB); CLARA 2020 ”Soutien à la mobilité des jeunes chercheurs en oncologie, N° CVPPRCAN000198” (JB); Fondation de France 2020 ”Aide à la mobilité international de médecins et pharmaciens, N° 00112162” (JB); Ligue contre le cancer 2021, comité de Saône-et-Loire (PS); 2017-INCa-DGOS-Inserm_12563: INCa SIRIC-LYriCAN INCa-DGOS-Inserm_12563 (PS)Ethics ApprovalThe study was conducted in accordance with all applicable laws, rules, and requests of French and European government authorities. Written informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France). Samples were obtained from the CRB Centre Léon Bérard (n°BB-0033-00050) which is quality certified according NFS96-900 French standard and ISO 9001 for clinical trials.ConsentWritten informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France)

The Dizi Series is exposed within the Southern Slope zone of the Greater Caucasus, in the core of the Svaneti anticlinorium. It is mainly composed of terrigenous, volcanogenic and carbonate rocks faunistically dated from the Devonian to the Triassic inclusive. Regional and contact metamorphism of the Dizi Series rocks was studied. It is stated that the degree of regional metamorphism corresponds to the chlorite-sericite subfacies of the greenschist facies, occurring at a temperature of 300–350°C and a pressure of 1.5–2.3 kbar. As a result of the action of the Middle Jurassic intrusive rock bodies, the regionally metamorphosed rocks of the Dizi Series underwent contact metamorphism. Three zones of contact metamorphism were distinguished corresponding to albite-epidote-hornfels, andalusite-biotite-muscovite-chlorite-hornfels and andalusite-biotite-muscovite-hornfels subfacies. Contact metamorphism took place at a significantly higher temperature and lower pressure than the preceding regional metamorphism. The maximum temperature of the contact metamorphism reached ≈ 570°С, while pressure varied within the range of ≈ 0.3–0.8 kbar. The evolution of rock associations of regional and contact metamorphism of the Dizi Series was studied. The fields of facies and subfacies of regional and contact metamorphism are shown in the Ps-T diagram. Three age populations of zircons were identified using U-Pb LA-ICP-MS dating of the diorite-porphyrite intrusion in the Dizi Series: Zrn1 (ca. 2200 Ma) and Zrn2 (458 ± 29 Ma) that were captured by the diorite-porphyrite magma from the ancient magmatic and metamorphic rocks of the crystalline basement, and Zrn3 (166.5 ± 4.6 Ma) that corresponds to the age of diorite-porphyrite crystallization.

Iron-oxide copper gold (IOCG)-uranium deposits represent South Australia’s primary resource base for copper production. The presence of daughter radionuclides (RN) from the 238U decay series within the ores necessitates a detailed understanding of their mineralogical deportment as a pre-requisite for attempts to remove or reduce RN concentrations. Research presented in this thesis contributes towards this knowledge by identifying and characterising potential RN-carriers, migration of radiogenic lead via geological processes, and provides evidence for RN sorption during processing. Novel approaches to RN reduction are proposed based on mineralogical-geochemical results. Evidence for migration of Pb within the deposit and during processing is relevant for any assessment of RN deportment, especially since the Pb-chalcogenides galena, clausthalite (PbSe) and altaite (PbTe) are often hosted within Cu-(Fe)-sulphides. Lead isotope values measured in-situ by laser ablation inductively coupled plasma mass spectrometry suggest an overwhelmingly radiogenic origin for Pb and thus extensive decoupling of radiogenic Pb from parent U- and Th-minerals. Calculated 207Pb/206Pb ratios suggest Pb mobilisation during an event that postdates the initial Mesoproterozoic Fe-Cu-Au-U mineralisation event, an interpretation consistent with other studies in the Olympic Cu-Au province which indicate cycles of replacement-remobilization-recrystallization. A nanoscale study of the most common of the three Pb-chalcogenide minerals, clausthalite, by high-angle annular dark field scanning transmission electron microscopy, proved highly instructive for identifying mechanisms of remobilization and overprinting. Characteristic symplectite textures involving clausthalite and host Cu-(Fe)-sulphides are indicative of formation via reaction between Se that pre-existed in solid solution within Cu-(Fe)-sulphides and migrating Pb. Observed superstructuring of clausthalite nanoparticles within chalcopyrite provides a direct link between solid solution and symplectite formation. Sr-Ca-REE-bearing aluminium-phosphate-sulphates (APS) of the alunite supergroup are a minor component of the Olympic Dam orebody. They appear paragenetically late, often replacing earlier REE-minerals. Characterisation of these compositionally zoned phases allowed them to be defined as minerals that span the compositional fields of woodhouseite and svanbergite, and also a REE- and phosphate-dominant group displaying solid solution towards florencite. A nanoscale secondary ion mass spectrometry study of RN distributions in APS minerals in acid-leached copper concentrate revealed that APS minerals readily sorb products of 238U decay, notably 226Ra and 210Pb, whereas U remains in solution. Many APS phases, particularly those that are Pb-bearing, are stable over a wide range of pH and Eh conditions and at temperatures up to 450 °C. As such, synthetic APS phases represent viable candidates not only for the removal of radionuclides from metallurgical streams, but also for their safe storage and isolation from surrounding environments. Ca-Sr-dominant phases display preferential enrichment by Pb (notably 210Pb) during flotation. 210Pb uptake then increases during subsequent acid leaching. Mixed Ca- and Sr-bearing APS phases were synthesised by modifying existing recipes to test the role of compositional variability of APS phases on the sorption rate of Pb from dilute Pb(NO3)2 solution. Lead incorporation by the synthetic APS phases was confirmed, whereby Pb replaces Ca, but not Sr, within the APS crystal structure. Extended X-ray absorption fine structure analysis of the resulting solids reveals the nature of Pb sorption by the synthesized material. The data showed that the dynamic incorporation of Pb by APS phases occurred overwhelmingly at pH 3.5, thus verifying that uptake of Pb by synthetic APS phases may represent a robust mechanism to achieve both reduction and immobilisation of 210Pb within metallurgical processing streams.
Thesis (Ph.D.) -- University of Adelaide, School of Chemical Engineering & Advanced Materials, 2020