2,475 research outputs found
Double In Situ Approach for the Preparation of Polymer Nanocomposite with Multi-functionality
A novel one-step synthetic route, the double in situ approach, is used to produce both TiO2nanoparticles and polymer (PET), and simultaneously forming a nanocomposite with multi-functionality. The method uses the release of water during esterification to hydrolyze titanium (IV) butoxide (Ti(OBu)4) forming nano-TiO2in the polymerization vessel. This new approach is of general significance in the preparation of polymer nanocomposites, and will lead to a new route in the synthesis of multi-functional polymer nanocomposites
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Implementation of earlier antibiotic administration in patients with severe sepsis and septic shock in Japan: a descriptive analysis of a prospective observational study.
BACKGROUND: Time to antibiotic administration is a key element in sepsis care; however, it is difficult to implement sepsis care bundles. Additionally, sepsis is different from other emergent conditions including acute coronary syndrome, stroke, or trauma. We aimed to describe the association between time to antibiotic administration and outcomes in patients with severe sepsis and septic shock in Japan. METHODS: This prospective observational study enrolled 1184 adult patients diagnosed with severe sepsis based on the Sepsis-2 criteria and admitted to 59 intensive care units (ICUs) in Japan between January 1, 2016, and March 31, 2017, as the sepsis cohort of the Focused Outcomes Research in Emergency Care in Acute Respiratory Distress Syndrome, Sepsis and Trauma (FORECAST) study. We compared the characteristics and in-hospital mortality of patients administered with antibiotics at varying durations after sepsis recognition, i.e., 0-60, 61-120, 121-180, 181-240, 241-360, and 361-1440 min, and estimated the impact of antibiotic timing on risk-adjusted in-hospital mortality using the generalized estimating equation model (GEE) with an exchangeable, within-group correlation matrix, with "hospital" as the grouping variable. RESULTS: Data from 1124 patients in 54 hospitals were used for analyses. Of these, 30.5% and 73.9% received antibiotics within 1 h and 3 h, respectively. Overall, the median time to antibiotic administration was 102 min [interquartile range (IQR), 55-189]. Compared with patients diagnosed in the emergency department [90 min (IQR, 48-164 min)], time to antibiotic administration was shortest in patients diagnosed in ICUs [60 min (39-180 min)] and longest in patients transferred from wards [120 min (62-226)]. Overall crude mortality was 23.4%, where patients in the 0-60 min group had the highest mortality (28.0%) and a risk-adjusted mortality rate [28.7% (95% CI 23.3-34.1%)], whereas those in the 61-120 min group had the lowest mortality (20.2%) and risk-adjusted mortality rates [21.6% (95% CI 16.5-26.6%)]. Differences in mortality were noted only between the 0-60 min and 61-120 min groups. CONCLUSIONS: We could not find any association between earlier antibiotic administration and reduction in in-hospital mortality in patients with severe sepsis
AKARI-CAS --- Online Service for AKARI All-Sky Catalogues
The AKARI All-Sky Catalogues are an important infrared astronomical database
for next-generation astronomy that take over the IRAS catalog. We have
developed an online service, AKARI Catalogue Archive Server (AKARI-CAS), for
astronomers. The service includes useful and attractive search tools and visual
tools.
One of the new features of AKARI-CAS is cached SIMBAD/NED entries, which can
match AKARI catalogs with other catalogs stored in SIMBAD or NED. To allow
advanced queries to the databases, direct input of SQL is also supported. In
those queries, fast dynamic cross-identification between registered catalogs is
a remarkable feature. In addition, multiwavelength quick-look images are
displayed in the visualization tools, which will increase the value of the
service.
In the construction of our service, we considered a wide variety of
astronomers' requirements. As a result of our discussion, we concluded that
supporting users' SQL submissions is the best solution for the requirements.
Therefore, we implemented an RDBMS layer so that it covered important
facilities including the whole processing of tables. We found that PostgreSQL
is the best open-source RDBMS products for such purpose, and we wrote codes for
both simple and advanced searches into the SQL stored functions. To implement
such stored functions for fast radial search and cross-identification with
minimum cost, we applied a simple technique that is not based on dividing
celestial sphere such as HTM or HEALPix. In contrast, the Web application layer
became compact, and was written in simple procedural PHP codes. In total, our
system realizes cost-effective maintenance and enhancements.Comment: Yamauchi, C. et al. 2011, PASP..123..852
Genomic Heterogeneity in a Natural Archaeal Population Suggests a Model of tRNA Gene Disruption
Understanding the mechanistic basis of the disruption of tRNA genes, as manifested in the intron-containing and split tRNAs found in Archaea, will provide considerable insight into the evolution of the tRNA molecule. However, the evolutionary processes underlying these disruptions have not yet been identified. Previously, a composite genome of the deep-branching archaeon Caldiarchaeum subterraneum was reconstructed from a community genomic library prepared from a C. subterraneum–dominated microbial mat. Here, exploration of tRNA genes from the library reveals that there are at least three types of heterogeneity at the tRNAThr(GGU) gene locus in the Caldiarchaeum population. All three involve intronic gain and splitting of the tRNA gene. Of two fosmid clones found that encode tRNAThr(GGU), one (tRNAThr-I) contains a single intron, whereas another (tRNAThr-II) contains two introns. Notably, in the clone possessing tRNAThr-II, a 5′ fragment of the tRNAThr-I (tRNAThr-F) gene was observed 1.8-kb upstream of tRNAThr-II. The composite genome contains both tRNAThr-II and tRNAThr-F, although the loci are >500 kb apart. Given that the 1.8-kb sequence flanked by tRNAThr-F and tRNAThr-II is predicted to encode a DNA recombinase and occurs in six regions of the composite genome, it may be a transposable element. Furthermore, its dinucleotide composition is most similar to that of the pNOB8-type plasmid, which is known to integrate into archaeal tRNA genes. Based on these results, we propose that the gain of the tRNA intron and the scattering of the tRNA fragment occurred within a short time frame via the integration and recombination of a mobile genetic element
The development of a knowledge base for basic active structures: an example case of dopamine agonists
<p>Abstract</p> <p>Background</p> <p>Chemical compounds affecting a bioactivity can usually be classified into several groups, each of which shares a characteristic substructure. We call these substructures "basic active structures" or BASs. The extraction of BASs is challenging when the database of compounds contains a variety of skeletons. Data mining technology, associated with the work of chemists, has enabled the systematic elaboration of BASs.</p> <p>Results</p> <p>This paper presents a BAS knowledge base, BASiC, which currently covers 46 activities and is available on the Internet. We use the dopamine agonists D1, D2, and Dauto as examples and illustrate the process of BAS extraction. The resulting BASs were reasonably interpreted after proposing a few template structures.</p> <p>Conclusions</p> <p>The knowledge base is useful for drug design. Proposed BASs and their supporting structures in the knowledge base will facilitate the development of new template structures for other activities, and will be useful in the design of new lead compounds via reasonable interpretations of active structures.</p
Growth behavior of titanium dioxide thin films at different precursor temperatures
The hydrophilic TiO2 films were successfully deposited on slide glass substrates using titanium tetraisopropoxide as a single precursor without carriers or bubbling gases by a metal-organic chemical vapor deposition method. The TiO2 films were employed by scanning electron microscopy, Fourier transform infrared spectrometry, UV-Visible [UV-Vis] spectroscopy, X-ray diffraction, contact angle measurement, and atomic force microscopy. The temperature of the substrate was 500°C, and the temperatures of the precursor were kept at 75°C (sample A) and 60°C (sample B) during the TiO2 film growth. The TiO2 films were characterized by contact angle measurement and UV-Vis spectroscopy. Sample B has a very low contact angle of almost zero due to a superhydrophilic TiO2 surface, and transmittance is 76.85% at the range of 400 to 700 nm, so this condition is very optimal for hydrophilic TiO2 film deposition. However, when the temperature of the precursor is lower than 50°C or higher than 75°C, TiO2 could not be deposited on the substrate and a cloudy TiO2 film was formed due to the increase of surface roughness, respectively
G-type antiferromagnetism and orbital ordering due to the crystal field from the rare-earth ions induced by the GdFeO_3-type distortion in RTiO_3 with R=La, Pr, Nd and Sm
The origin of the antiferromagnetic order and puzzling properties of LaTiO_3
as well as the magnetic phase diagram of the perovskite titanates are studied
theoretically. We show that in LaTiO_3, the t_{2g} degeneracy is eventually
lifted by the La cations in the GdFeO_3-type structure, which generates a
crystal field with nearly trigonal symmetry. This allows the description of the
low-energy structure of LaTiO_3 by a single-band Hubbard model as a good
starting point. The lowest-orbital occupation in this crystal field stabilizes
the AFM(G) state, and well explains the spin-wave spectrum of LaTiO_3 obtained
by the neutron scattering experiment. The orbital-spin structures for RTiO_3
with R=Pr, Nd and Sm are also accounted for by the same mechanism. We point out
that through generating the R crystal field, the GdFeO_3-type distortion has a
universal relevance in determining the orbital-spin structure of the perovskite
compounds in competition with the Jahn-Teller mechanism, which has been
overlooked in the literature. Since the GdFeO_3-type distortion is a universal
phenomenon as is seen in a large number of perovskite compounds, this mechanism
may also play important roles in other compounds of this type.Comment: 20 pages, 15 figure
Self-cleaning and colour-preserving efficiency of photocatalytic concrete: case study of the Jubilee Church in Rome
The Jubilee Church in the south-eastern outskirts of Rome is one of the first buildings constructed with super white reinforced concrete with self-cleaning photocatalytic cement. However, 16 years after the opening of the building, the self-cleaning and colour-preserving properties arising from the titania particles (TiO2) within the concrete mix are not meeting the design requirements and the concrete is showing premature evidence of decay. While the form of the decay is affecting the appearance of the building and not its structural soundness, the ageing pattern of the building's components is resulting in a high maintenance cost, one not easily affordable within the ordinary budget supported by a small parish. This study comprises the first comprehensive step in understanding the causes of the accelerated ageing pattern of the concrete, highlighting methods to improve the long-term durability of the concrete and therefore reduce the cost of its maintenance. Moreover, this research offered the opportunity to test the durability and the effectiveness of the TiO2 in the real conditions on an actual building featuring non-standard geometries. The findings highlight how the ageing pattern directly connects with the geometry of the building and inadequate consideration of the local weathering at the design stage
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