26,331 research outputs found
Nucleation and growth of SnO2 nanowires
No full textSemiconducting oxides in nanowire-shape have stimulated a great interest for applications in optics and sensor fields. Recently, it has been reported that tin oxide (SnO2) nanowires can be grown by vapor transport techniques through a vapor-liquid-solid (VLS) mechanism. In this work, we present the results of a study on the mechanism involved in the crystallization process of SnO2 nanowires, pointing out that the presence of a liquid phase is necessary to grow these nanocrystals in the 800-1000 degrees C temperature range. Characterization of the obtained samples has been performed by XRD, TEM and SEM analysis. (C) 2004 Elsevier B. V. All rights reserved
Can lung weight be measured by computed tomography?
No full textIntroduction Computed Tomography (CT) may be a non-invasive tool for measuring lung weight (a surrogate of edema) in vivo [1]. Aim To compare lung weight measured with the balance with lung weight measured with CT scan. Methods Thirteen sedated and mechanically ventilated piglets (21 ± 3 Kg) underwent lung CT at the end of different experimental protocols and were then sacrificed. Lungs were excised and weighed on a balance. Pre-mortem CT scans were manually delineated and processed with a dedicated software (quantitative analysis). Lung weights measured with the balance (reference) were compared with those obtained with CT. Results Lung weight measured with the balance was 407 ± 236 g and lung weight obtained by quantitative analysis of CT scan was 509 ± 232 g (P < 0,001; paired t-test). Comparison between the two methods is reported in Figure.
Figure. Bland & Altman plot. X axis: mean of the results obtained with the two methods. Y axis: difference between the two results (lung weight measured with the balance acted as reference method).
Conclusions On average, CT overestimated lung weight (as measured with the balance) by 100 g. Since CT scan was taken before autopsy (and exsanguination) this discrepancy is likely explained by greater (and heavier) pulmonary blood content.[1] Gattinoni L., Cressoni M., Intensive Care Med, 2010; 36:1803-180
Mandibular reconstruction in head and neck cancer: which is the gold standard?
No full textIntroduction: The aim of this study is to perform a systematic review to compare the outcomes of the different surgical options for mandibular reconstruction in head and neck cancer. Material and methods: 93 articles were selected. Four groups were identified: titanium plate without flaps, titanium plate covered by soft tissue flap, bone tissue flaps and double flaps. We compared patients’ characteristics, site of mandibulectomy, type of reconstruction and complications. Results: 4697 patients were reported. The groups were not homogeneous regarding the type of defect and the treatment history. A significant difference in terms of post-operative complications was found between group 1 and group 2 (p < 0.00001), and between group 2 and group 3 (p < 0.00001). Total complications rate for group 4 was significantly higher when compared to group 3 (p < 0.00001), but no significant difference was found with group 2. Conclusion: These results suggest that mandibular reconstruction using a microvascular bone flap is the best surgical option in patients without significant comorbidities
Nanosized Ti-doped MoO3 thin films for gas-sensing application
No full textDevelopment of MoO3 as a novel material for gas sensing was addressed. Thin filmswere produced by reactive rf sputtering assisted by annealing. Doping with Ti was performed to enhance the conductance of the MoO3 film. It came out that the layers were two orders of magnitude more conductive than undoped material. Good and reversible response to CO was achieved at 300°C, which fell off at higher temperatures. An interesting feature of the films was a considerably fast response for both CO and NO2 despite low operating temperature. Doped films were found to operate at best about 100°C below than for pure MoO3 layers
The automorphism groups of the vertex operator algebras V+L: general case
No full textIn this article, we give a method of calculating the automorphism groups of the vertex operator algebras V+L associated with even lattices L. For example, by using this method we determine the automorphism groups of V+L for even lattices of rank one, two and three, and even unimodular lattices.
The author was supported by the Japan Society for the Promotion of Science Research Fellowships for Young Scientists and COE grant of Hokkaido University
Mammalian Target of Rapamycin: Is It Relevant to COPD Pathogenesis or Treatment?
No full textThe mammalian target of rapamycin (mTOR) signalling pathway regulates fundamental metabolic
processes such as inflammation, autophagy and apoptosis, all of which influence cell fate. Recent
experimental data suggest that mTOR signalling is involved in many diseases, including lung diseases,
but with contrasting data. Overexpression of mTOR and its signalling proteins have been
linked to lung cell senescence and development of emphysema, pulmonary hypertension and
inflammation. On the other hand, mTOR inhibitors, as rapamycin and/or its derivatives, restore corticosteroid
sensitivity in peripheral blood mononuclear cells from chronic obstructive pulmonary
disease (COPD) patients, and overexpression of mTOR suppresses cigarette smoke-induced inflammation
and emphysema, suggesting that induction of mTOR expression/activity might be useful
to treat COPD. This apparent discrepancy is due to complex and heterogenic enzymatic pathway
of mTOR. Translation of pre-clinical positive data on the use of mTOR inhibitors to COPD therapy
needs a more in-depth knowledge of mTOR signalling
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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