Laser anneal of oxycarbosilane low-k film

Submilisecond laser anneal has been experimentally investigated for porogen removal and its ability to improve the mechanical strength in oxycarbosilane ultra low-k films compromised due to the introduction of porosity. We report the occurrence of extensive bond rearrangements inferred from Fourier-transform infra-red (FTIR) spectroscopy, elastic recoil detection (ERD) and spectroscopic ellipsometry (SE) in the energy range of 1.4-8 eV. The laser anneal affects most notably the organic content of the organosilicate matrix leading to depletion and reorganization. Nevertheless, the tested conditions reveal a processing window which allows for 13% improvement of Young’s modulus as compared to the reference film, annealed in a conventional furnace at 400°C for 2 h, while not impacting the relative dielectric constant of 2.25

Acute Pancreatitis Complicated with Choledochal Duct Rupture

Recurrent acute pancreatitis is a rare clinical entity in childhood with unknown incidence (Rosendahl et al., 2007) and often occurring in a familial context. Genetic factors such as PRSS1 mutations (cationic trypsinogen gene) can be found in some patients. However, many remain idiopathic. The natural history remains poorly documented and the most frequent complications reported are pain, exocrine pancreatic insufficiency, diabetes mellitus, and pancreatic adenocarcinoma after long-standing hereditary pancreatitis. We describe a patient with hereditary pancreatitis in whom a mild pancreatitis episode was complicated by a perforation of the ductus choledochus

Mitochondrial mosaics in the liver of 3 infants with mtDNA defects

<p>Abstract</p> <p>Background</p> <p>In muscle cytochrome oxidase (COX) negative fibers (mitochondrial mosaics) have often been visualized.</p> <p>Methods</p> <p>COX activity staining of liver for light and electron microscopy, muscle stains, blue native gel electrophoresis and activity assays of respiratory chain proteins, their immunolocalisation, mitochondrial and nuclear DNA analysis.</p> <p>Results</p> <p>Three unrelated infants showed a mitochondrial mosaic in the liver after staining for COX activity, i.e. hepatocytes with strongly reactive mitochondria were found adjacent to cells with many negative, or barely reactive, mitochondria. Deficiency was most severe in the patient diagnosed with Pearson syndrome. Ragged-red fibers were absent in muscle biopsies of all patients. Enzyme biochemistry was not diagnostic in muscle, fibroblasts and lymphocytes. Blue native gel electrophoresis of liver tissue, but not of muscle, demonstrated a decreased activity of complex IV; in both muscle and liver subcomplexes of complex V were seen. Immunocytochemistry of complex IV confirmed the mosaic pattern in two livers, but not in fibroblasts. MRI of the brain revealed severe white matter cavitation in the Pearson case, but only slight cortical atrophy in the Alpers-Huttenlocher patient, and a normal image in the 3rd. MtDNA in leucocytes showed a common deletion in 50% of the mtDNA molecules of the Pearson patient. In the patient diagnosed with Alpers-Huttenlocher syndrome, mtDNA was depleted for 60% in muscle. In the 3rd patient muscular and hepatic mtDNA was depleted for more than 70%. Mutations in the nuclear encoded gene of <it>POLG </it>were subsequently found in both the 2nd and 3rd patients.</p> <p>Conclusion</p> <p>Histoenzymatic COX staining of a liver biopsy is fast and yields crucial data about the pathogenesis; it indicates whether mtDNA should be assayed. Each time a mitochondrial disorder is suspected and muscle data are non-diagnostic, a liver biopsy should be recommended. Mosaics are probably more frequent than observed until now. A novel pathogenic mutation in <it>POLG </it>is reported.</p> <p>Tentative explanations for the mitochondrial mosaics are, in one patient, unequal partition of mutated mitochondria during mitoses, and in two others, an interaction between products of several genes required for mtDNA maintenance.</p

Exploration des communautés bactériennes dans les systèmes aquaponiques

Aquaponics is a production system based on the dynamic equilibrium between fish, plants, and microorganisms. In order to better understand the role of microorganisms in this tripartite relationship, we studied the bacterial communities hosted in eight aquaponic and aquaculture systems. The bacterial communities were analyzed by 16S rRNA gene deep sequencing. At the phylum level, the bacterial communities from all systems were relatively similar with a predominance of Proteobacteria and Bacteroidetes. At the genus level, however, the communities present in the sampled systems were more heterogeneous. The biofilter samples harbored more diverse communities than the corresponding sump samples. The core microbiomes from the coupled and decoupled systems shared more common operational taxonomic units than with the aquaculture systems. Eventually, some of the taxa identified in the systems could have beneficial functions for plant growth and health, but a deeper analysis would be required to identify the precise functions involved in aquaponics

High-k dielectrics and metal gates for future generation memory devices

The requirements and development of high-k dielectric films for application in storage cells of future generation flash and Dynamic Random Access Memory (DRAM) devices are reviewed. Dielectrics with k-value in the 9-30 range are studied as insulators between charge storage layers and control gates in flash devices. For this application, large band gaps (> 6 eV) and band offsets are required, as well as low trap densities. Materials studied include aluminates and scandates. For DRAM metal-insulator-metal (MIM) capacitors, aggressive scaling of the equivalent oxide thickness (with targets down to 0.3 nm) drives the research towards dielectrics with k-values > 50. Due to the high aspect ratio of MIMCap structures, highly conformal deposition techniques are needed, triggering a substantial effort to develop Atomic Layer Deposition (ALD) processes for the deposition of metal gates and high-k dielectrics. Materials studied include Sr and Ba-based perovskites, with SrTiO3 as one of the most promising candidates, as well as tantalates, titanates and niobates