An EXAFS study of the interaction of different reactant gases over nanometer scale Pt clusters deposited on γ-Al2O3

Face to the difficulty to find an efficient catalyst in the reduction of NO by hydrocarbon in diesel exhaust gases, we have examined the interaction of some concerned reactant gases, NO, C₃H₆ and O₂, with a catalyst constituted of nanometer scale platinum particles deposited on alumina. Indeed, in order to understand the catalytic process, it seems essential to have information on the adsorption process and on the evolution of the structural parameters of the particles when submitted to such gases. This work has been performed on a 1% Pt/Al₂O₃ catalyst by using in situ EXAFS measurements. We have concentrated our study, on the one hand, on the influence of NO, C₃H₆ in the presence or not of an excess of oxygen and, on the other hand, on the influence of the total mixture. The most striking result is the growth of the platinum particles under NO. Moreover, when the catalyst is submitted either to a mixture of NO + O₂ or C₃H₆ + O₂, the particles are not fully oxidised. With the total mixture, the particles both grow and are oxidised.     

Influence of Alumina-Supported M–Pt Catalysts in DeNOx Reactions with M = Pd or Ir or Ru

To better understand N₂ formation in the selective catalytic reduction of NO _x by propene under oxidative atmosphere, we studied the catalytic behavior of bimetallics. Surface segregation phenomena may provoke geometric and electronic modifications of the catalytic active sites. To explain our results we invoked: (i) the facile way to oxidize the bimetallic aggregates, (ii) the presence of atoms with low coordination number able to be oxidized first and (iii) an eventual formation of like vic-diNO _x species on such bimetallics leading to N₂ formation.     

Nanoscale Phase Separation in Lithium Niobium Silicate Glass by Femtosecond Laser Irradiation

Understanding the phase transformation in glass and the morphology of related nanostructure after femtosecond laser irradiation is of great importance for fabricating functional optics, in which glass crystallization is involved to obtain nonlinear optical properties. We report on the crystallization inside lithium niobium silicate glass induced by fs laser irradiation. Energy‐dispersive X‐ray spectroscopy coupled to scanning transmission electron microscopy (STEM/EDS) and transmission electron microscopy confirm a nanoscale phase separation whereby LiNbO₃ crystals are embedded in lamella‐shaped frames of amorphous SiO₂. The obtained nanostructure may have applications in fabricating second‐order nonlinear optical devices.     

Effects of Aluminium Contamination on the Nervous System of Freshwater Aquatic Vertebrates: A Review

Aluminium (Al) is the most common natural metallic element in the Earth’s crust. It is released into the environment through natural processes and human activities and accumulates in aquatic environments. This review compiles scientific data on the neurotoxicity of aluminium contamination on the nervous system of aquatic organisms. More precisely, it helps identify biomarkers of aluminium exposure for aquatic environment biomonitoring in freshwater aquatic vertebrates. Al is neurotoxic and accumulates in the nervous system of aquatic vertebrates, which is why it could be responsible for oxidative stress. In addition, it activates and inhibits antioxidant enzymes and leads to changes in acetylcholinesterase activity, neurotransmitter levels, and in the expression of several neural genes and nerve cell components. It also causes histological changes in nerve tissue, modifications of organism behaviour, and cognitive deficit. However, impacts of aluminium exposure on the early stages of aquatic vertebrate development are poorly described. Lastly, this review also poses the question of how accurate aquatic vertebrates (fishes and amphibians) could be used as model organisms to complement biological data relating to the developmental aspect. This “challenge” is very relevant since freshwater pollution with heavy metals has increased in the last few decades.     

Contribution to the environmental performance of the dry-vibratory drilling technology

The self-vibratory drilling (SVD) is an innovative technology that allows increasing the productivity, without coolant. The aim of this paper is to prove that the environmental impacts of SVD are significantly less than those of traditional drilling (TD) and to quantify them. The study is based on a life cycle analysis of both processes. The major contributor to the environmental impacts in TD is the coolant. The new major contributors in SVD are the twist drills. A model that links the lifespan of the twist drills and the environmental impacts of SVD has been developed to support decisions for R&D.     

Comparing the Performance of Organic Solvent Nanofiltration Membranes in Non-Polar Solvents

Organic solvent nanofiltration (OSN) is gradually expanding from academic research to industrial implementation. The need for membranes with low and sharp molecular weight cutoffs that are able to operate under aggressive OSN conditions is increasing. However, the lack of comparable and uniform performance data frustrates the screening and membrane selection for processes. Here, a collaboration is presented between several academic and industrial partners analyzing the separation performance of 10 different membranes using three model process mixtures. Membrane materials range from classic polymeric and thin film composites (TFCs) to hybrid ceramic types. The model solutions were chosen to mimic cases relevant to today's industrial use: relatively low molar mass solutes (330–550 Da) in n-heptane, toluene, and anisole.     

TP53 Targeted Deep Sequencing of Cell-Free DNA in Esophageal Squamous Cell Carcinoma Using Low-Quality Serum: Concordance with Tumor Mutation

Circulating cell-free DNA (cfDNA) is emerging as a potential tumor biomarker. CfDNA-based biomarkers may be applicable in tumors without an available non-invasive screening method among at-risk populations. Esophageal squamous cell carcinoma (ESCC) and residents of the Asian cancer belt are examples of those malignancies and populations. Previous epidemiological studies using cfDNA have pointed to the need for high volumes of good quality plasma (i.e., >1 mL plasma with 0 or 1 cycles of freeze-thaw) rather than archival serum, which is often the main available source of cfDNA in retrospective studies. Here, we have investigated the concordance of TP53 mutations in tumor tissue and cfDNA extracted from archival serum left-over from 42 cases and 39 matched controls (age, gender, residence) in a high-risk area of Northern Iran (Golestan). Deep sequencing of TP53 coding regions was complemented with a specialized variant caller (Needlestack). Overall, 23% to 31% of mutations were concordantly detected in tumor and serum cfDNA (based on two false discovery rate thresholds). Concordance was positively correlated with high cfDNA concentration, smoking history (p-value = 0.02) and mutations with a high potential of neoantigen formation (OR; 95%CI = 1.9 (1.11–3.29)), suggesting that tumor DNA release in the bloodstream might reflect the effects of immune and inflammatory context on tumor cell turnover. We identified TP53 mutations in five controls, one of whom was subsequently diagnosed with ESCC. Overall, the results showed that cfDNA mutations can be reliably identified by deep sequencing of archival serum, with a rate of success comparable to plasma. Nonetheless, 70% non-identifiable mutations among cancer patients and 12% mutation detection in controls are the main challenges in applying cfDNA to detect tumor-related variants when blindly targeting whole coding regions of the TP53 gene in ESCC.     

Mass Spectrometry-Based Proteomics Reveal Alcohol Dehydrogenase 1B as a Blood Biomarker Candidate to Monitor Acetaminophen-Induced Liver Injury

Acute liver injury (ALI) is a severe disorder resulting from excessive hepatocyte cell death, and frequently caused by acetaminophen intoxication. Clinical management of ALI progression is hampered by the dearth of blood biomarkers available. In this study, a bioinformatics workflow was developed to screen omics databases and identify potential biomarkers for hepatocyte cell death. Then, discovery proteomics was harnessed to select from among these candidates those that were specifically detected in the blood of acetaminophen-induced ALI patients. Among these candidates, the isoenzyme alcohol dehydrogenase 1B (ADH1B) was massively leaked into the blood. To evaluate ADH1B, we developed a targeted proteomics assay and quantified ADH1B in serum samples collected at different times from 17 patients admitted for acetaminophen-induced ALI. Serum ADH1B concentrations increased markedly during the acute phase of the disease, and dropped to undetectable levels during recovery. In contrast to alanine aminotransferase activity, the rapid drop in circulating ADH1B concentrations was followed by an improvement in the international normalized ratio (INR) within 10–48 h, and was associated with favorable outcomes. In conclusion, the combination of omics data exploration and proteomics revealed ADH1B as a new blood biomarker candidate that could be useful for the monitoring of acetaminophen-induced ALI.     

Multi-level analysis of an interaction network between individuals in a mailing-list

It is well known now that most real-world complex networks have some properties which make them very different from random networks. In the case of interactions between authors of messages in a mailing-list, however, a multi-level structure may be responsible for some of these properties. We propose here a rigorous but simple formalism to investigate this question, and we apply it to an archive of the Debian user mailing-list. This leads to the identification of some properties which may indeed be explained this way, and of some properties which need deeper analysis.     

Depth and depth–color coding using shape-adaptive wavelets

We present a novel depth and depth–color codec aimed at free-viewpoint 3D-TV. The proposed codec uses a shape-adaptive wavelet transform and an explicit encoding of the locations of major depth edges. Unlike the standard wavelet transform, the shape-adaptive transform generates small wavelet coefficients along depth edges, which greatly reduces the bits required to represent the data. The wavelet transform is implemented by shape-adaptive lifting, which enables fast computations and perfect reconstruction. We derive a simple extension of typical boundary extrapolation methods for lifting schemes to obtain as many vanishing moments near boundaries as away from them. We also develop a novel rate-constrained edge detection algorithm, which integrates the idea of significance bitplanes into the Canny edge detector. Together with a simple chain code, it provides an efficient way to extract and encode edges. Experimental results on synthetic and real data confirm the effectiveness of the proposed codec, with PSNR gains of more than 5 dB for depth images and significantly better visual quality for synthesized novel view images.