405 research outputs found
Hierarchically organized nanostructured TiO2 for photocatalysis applications
A template-free process for the synthesis of nanocrystalline TiO2
hierarchical microstructures by reactive Pulsed Laser Deposition (PLD) is here
presented. By a proper choice of deposition parameters a fine control over the
morphology of TiO2 microstructures is demonstrated, going from classical
compact/columnar films to a dense forest of distinct hierarchical assemblies of
ultrafine nanoparticles (<10 nm), up to a more disordered, aerogel-type
structure. Correspondingly, film density varies with respect to bulk TiO2
anatase, with a degree of porosity going from 48% to over 90%. These structures
are stable with respect to heat treatment at 400 centigrade degrees, which
results in crystalline ordering but not in morphological changes down to the
nanoscale. Both as deposited and annealed films exhibit very promising
photocatalytic properties, even superior to standard Degussa P25 powder, as
demonstrated by the degradation of stearic acid as a model molecule. The
observed kinetics are correlated to the peculiar morphology of the PLD grown
material. We show that the 3D multi-scale hierarchical morphology enhances
reaction kinetics and creates an ideal environment for mass transport and
photon absorption, maximizing the surface area-to-volume ratio while at the
same time providing readily accessible porosity through the large inter-tree
spaces that act as distributing channels. The reported strategy provides a
versatile technique to fabricate high aspect ratio 3D titania microstuctures
through a hierarchical assembly of ultrafine nanoparticles. Beyond
photocatalytic and catalytic applications, this kind of material could be of
interest for those applications where high surface-to-volume and efficient mass
transport are required at the same time.Comment: 10 pages, 7 figures, Nanotechnology (accepted
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Lateral Selective SiGe Growth for Local Dislocation-Free SiGe-on-Insulator Virtual Substrate Fabrication
Dislocation free local SiGe-on-insulator (SGOI) virtual substrate is fabricated using lateral selective SiGe growth by reduced pressure chemical vapor deposition. The lateral selective SiGe growth is performed around a ∼1.25 μm square Si (001) pillar in a cavity formed by HCl vapor phase etching of Si at 850 °C from side of SiO2/Si mesa structure on buried oxide. Smooth root mean square roughness of SiGe surface of 0.14 nm, which is determined by interface roughness between the sacrificially etched Si and the SiO2 cap, is obtained. Uniform Ge content of ∼40% in the laterally grown SiGe is observed. In the Si pillar, tensile strain of ∼0.65% is found which could be due to thermal expansion difference between SiO2 and Si. In the SiGe, tensile strain of ∼1.4% along 〈010〉 direction, which is higher compared to that along 〈110〉 direction, is observed. The tensile strain is induced from both [110] and [−110] directions. Threading dislocations in the SiGe are located only ∼400 nm from Si pillar and stacking faults are running towards 〈110〉 directions, resulting in the formation of a wide dislocation-free area in SiGe along 〈010〉 due to horizontal aspect ratio trapping
Correction to: Ret is essential to mediate GDNF’s neuroprotective and neuroregenerative effect in a Parkinson disease mouse model
Correction to: Cell Death Dis. (2016) 7, e2359; https://doi.org/10.1038/cddis.2016.263; published online 08 September 2016</jats:p
Fabrication of low-loss SOI nano-waveguides including BEOL processes for nonlinear applications
We report successful fabrication of low-loss SOI nano-waveguides with integrated PIN diode structures. The entire fabrication process is done on a 200 mm BiCMOS toolset using front-end-of-line (FEOL) and back-end-of-line (BEOL) processes and does not show any undesirable influence upon the photonic performance. Such a waveguide technology forms an attractive platform for a wide range of nonlinear applications due to efficient free carrier removal as well as use of standard substrates and processing technology. Nonlinear experiments were conducted to investigate the potential of the introduced technology. The performance of the designed waveguides can be used as a benchmark for future development of proposed platform for integrated silicon photonics and electronics circuits
Iron Status and Analysis of Efficacy and Safety of Ferric Carboxymaltose Treatment in Patients with Inflammatory Bowel Disease
Background and Aims:We analyzed iron deficiency and the therapeutic response following intravenous ferric carboxymaltose in a large single-center inflammatory bowel disease (IBD) cohort. Methods: 250 IBD patients were retrospectively analyzed for iron deficiency and iron deficiency anemia. A subgroup was analyzed regarding efficacy and side effects of iron supplementation with ferric carboxymaltose. Results: In the cohort (n = 250), 54.4% of the patients had serum iron levels 60 mu g/dl, 61.6% had ferritin >100 ng/ml, and 90.7% reached Hb >12/13 g/dl at follow-up (p < 0.0001 for all parameters vs. pretreatment values). The most frequent adverse event was a transient increase of liver enzymes with male gender as risk factor (p = 0.008, OR 8.62, 95% CI 1.74-41.66). Conclusions: Iron deficiency and anemia are frequent in IBD patients. Treatment with ferric carboxymaltose is efficious, safe and well tolerated in iron-deficient IBD patients. Copyright (C) 2011 S. Karger AG, Base
Senate Executive Committee Minutes January 25, 2011
Minutes for the meeting of the Senate Executive Committee on January 25, 2011
ESSenTIAL : EPIXfab services specifically targeting (SME) industrial takeup of advanced silicon photonics
ePIXfab brings silicon photonics within reach of European small and medium sized enterprises, thereby building on its track record and its integration into Europractice. To this end, ePIXfab offers affordable access to standardized active and passive silicon photonic IC and packaging technology, a path from design to manufacturing and hands-on training. Based on a consortium of major research institutes with silicon photonics expertise, ePIXfab reaches out to European industry and supports them to evaluate silicon photonics in the context of concrete applications and markets. In order to ensure low-cost, quick access and scalability to manufacturing, the maturity of silicon photonic IC technology is enhanced by setting up a library of generic devices, a level of process and device benchmarking and a well maintained design flow. For the first time, devices in a standard package are offered to facilitate measurements. Training programs on the IC and packaging services are also offered, including hands-on training in making designs. Maturity, standardization and sustainability are driven by a steadily growing worldwide user base
Small bowel Crohn’s disease: MR enteroclysis and capsule endoscopy compared to balloon-assisted enteroscopy
New modalities are available to visualize the small bowel in patients with Crohn’s disease (CD). The aim of this study was to compare the diagnostic yield of magnetic resonance enteroclysis (MRE) and capsule endoscopy (CE) to balloon-assisted enteroscopy (BAE) in patients with suspected or established CD of the small bowel. Consecutive, consenting patients first underwent MRE followed by CE and BAE. Patients with high-grade stenosis at MRE did not undergo CE. Reference standard for small bowel CD activity was a combination of BAE and an expert panel consensus diagnosis. Analysis included 38 patients, 27 (71%) females, mean age 36 (20–74) years, with suspected (n = 20) or established (n = 18) small bowel CD: 16 (42%) were diagnosed with active CD, and 13 (34%) by MRE with suspected high-grade stenosis, who consequently did not undergo CE. The reference standard defined high-grade stenosis in 10 (26%) patients. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value of MRE and CE for small bowel CD activity were 73 and 57%, 90 and 89%, 88 and 67%, and 78 and 84%, respectively. CE was complicated by capsule retention in one patient. MRE has a higher sensitivity and PPV than CE in small bowel CD. The use of CE is considerably limited by the high prevalence of stenotic lesions in these patients
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