Ultimate behavior of idealized composite floor elements at ambient and elevated temperature

This paper is concerned with the ultimate behavior of composite floor slabs under extreme loading situations resembling those occurring during severe building fires. The study focuses on the failure state associated with rupture of the reinforcement in idealized slab elements, which become lightly reinforced in a fire situation due to the early loss of the steel deck. The paper describes a fundamental approach for assessing the failure limit associated with reinforcement fracture in lightly reinforced beams, representing idealized slab strips. A description of the ambient-temperature tests on isolated restrained elements, carried out to assess the influence of key material parameters on the failure conditions, is firstly presented. The results of a series of material tests, undertaken mainly to examine the effect of elevated temperature on ductility, are also described. A simplified analytical model is employed, in conjunction with the experimental findings, to assess the salient material parameters and their implications on the ultimate response at both ambient and elevated temperature. © 2009 Springer Science+Business Media, LLC

Tetra­kis[μ-1,4-bis­(4,5-dihydro-1,3-oxazol-2-yl)benzene-κ2 N:N′]tetra­kis­(μ-methano­lato-κ2 O:O)bis­(μ-perchlorato-κ2 O:O′)tetra­copper(II) bis­(perchlorate)

The title tetra­nuclear CuII complex, [Cu4(C12H12N2O2)4(CH3O)4(ClO4)2](ClO4)2, is located around an inversion center. Each CuII atom is coordinated by two cis-O atoms from two bridging methano­late anions and two cis-N atoms from two bridging 1,4-bis­(4,5-dihydro-1,3-oxazol-2-yl)benzene (L) ligands in the basal plane, and is further coordinated by one O atom of the bridging perchlorate anion, forming a distorted square-pyramidal geometry. The Cu⋯Cu separations in the recta­ngular core are 2.9878 (11) and 6.974 (1) Å. In the asymmetric unit, there are two L ligands with a syn conformation. In one L ligand, the dihedral angles between the central benzene ring and the terminal 4,5-dihydro-1,3-oxazol-2-yl mean planes are 22.1 (4) and 33.1 (4)°, and in the other L ligand the corresponding dihedral angles are 29.3 (4) and 29.9 (4)°. The uncoordinated perchlorate anion is linked with the complex mol­ecules via weak C—H⋯O hydrogen bonds

Poly[(μ3-quinoline-6-carboxyl­ato-κ3 N:O:O′)silver(I)]

In the title coordination polymer, [Ag(C10H6NO2)]n, the AgI cation is coordinated by two O atoms and one N atom from three 6-quinoline­carboxyl­ate anions in a distorted T-shaped AgNO2 geometry, in which the O—Ag—O angle is 160.44 (9)°. The 6-quinoline­carboxyl­ate anion bridges three Ag+ cations, forming a nearly planar polymeric sheet parallel to (101). The distance between Ag+ cations bridged by the carboxyl group is 2.9200 (5) Å. In the crystal, π–π stacking is observed between parallel quinoline ring systems, the centroid–centroid distance being 3.7735 (16) Å

Sequence Variations of Full-Length Hepatitis B Virus Genomes in Chinese Patients with HBsAg-Negative Hepatitis B Infection

BACKGROUND: The underlying mechanism of HBsAg-negative hepatitis B virus (HBV) infection is notoriously difficult to elucidate because of the extremely low DNA levels which define the condition. We used a highly efficient amplification method to overcome this obstacle and achieved our aim which was to identify specific mutations or sequence variations associated with this entity. METHODS: A total of 185 sera and 60 liver biopsies from HBsAg-negative, HBV DNA-positive subjects or known chronic hepatitis B (CHB) subjects with HBsAg seroclearance were amplified by rolling circle amplification followed by full-length HBV genome sequencing. Eleven HBsAg-positive CHB subjects were included as controls. The effects of pivotal mutations identified on regulatory regions on promoter activities were analyzed. RESULTS: 22 and 11 full-length HBV genomes were amplified from HBsAg-negative and control subjects respectively. HBV genotype C was the dominant strain. A higher mutation frequency was observed in HBsAg-negative subjects than controls, irrespective of genotype. The nucleotide diversity over the entire HBV genome was significantly higher in HBsAg-negative subjects compared with controls (p = 0.008) and compared with 49 reference sequences from CHB patients (p = 0.025). In addition, HBsAg-negative subjects had significantly higher amino acid substitutions in the four viral genes than controls (all p<0.001). Many mutations were uniquely found in HBsAg-negative subjects, including deletions in promoter regions (13.6%), abolishment of pre-S2/S start codon (18.2%), disruption of pre-S2/S mRNA splicing site (4.5%), nucleotide duplications (9.1%), and missense mutations in "alpha" determinant region, contributing to defects in HBsAg production. CONCLUSIONS: These data suggest an accumulation of multiple mutations constraining viral transcriptional activities contribute to HBsAg-negativity in HBV infection.published_or_final_versio

catena-Poly[[silver(I)-μ-1,2-bis­(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)ethane-κ2 N:N′] perchlorate hemihydrate]

In the title coordination polymer, {[Ag(C12H20N2O2)]ClO4·0.5H2O}n, the AgI cation is coordinated by two N atoms from two 1,2-bis­(4,4-dimethyl-4,5-dihydro-1,3-oxazol-2-yl)ethane (L) ligands in a nearly linear geometry [N—Ag—N = 171.07 (8)°]. The L ligand bridges adjacent Ag+ cations, forming a polymeric chain running along the c axis. The lattice water mol­ecule is situated on a twofold rotation axis, and links to the perchlorate anion via an O—H⋯O hydrogen bond. The long Ag⋯O separation of 3.200 (4) Å indicates a weak inter­action between the perchlorate anion and the AgI cation. Weak C—H⋯O hydrogen bonding occurs between the chain and the lattice water mol­ecule and between the chain and perchlorate anions. Both five-membered rings of the L ligand display envelope conformations; in one five-membered ring, the flap C atom is disordered on opposite sides of the ring with occupancies of 0.65 and 0.35

Identification of Hepatitis B Virus DNA Polymerase Sequences to Predict Virological Response to Entecavir Therapy

Poster Presentations: Emerging / Infectious DiseasesConference Theme: Translating Health Research into Policy and Practice for Health of the Populationpublished_or_final_versio

China’s rising hydropower demand challenges water sector

Demand for hydropower is increasing, yet the water footprints (WFs) of reservoirs and hydropower, and their contributions to water scarcity, are poorly understood. Here, we calculate reservoir WFs (freshwater that evaporates from reservoirs) and hydropower WFs (the WF of hydroelectricity) in China based on data from 875 representative reservoirs (209 with power plants). In 2010, the reservoir WF totaled 27.9 × 109 m3 (Gm3), or 22% of China’s total water consumption. Ignoring the reservoir WF seriously underestimates human water appropriation. The reservoir WF associated with industrial, domestic and agricultural WFs caused water scarcity in 6 of the 10 major Chinese river basins from 2 to 12 months annually. The hydropower WF was 6.6 Gm3 yr−1 or 3.6 m3 of water to produce a GJ (109 J) of electricity. Hydropower is a water intensive energy carrier. As a response to global climate change, the Chinese government has promoted a further increase in hydropower energy by 70% by 2020 compared to 2012. This energy policy imposes pressure on available freshwater resources and increases water scarcity. The water-energy nexus requires strategic and coordinated implementations of hydropower development among geographical regions, as well as trade-off analysis between rising energy demand and water use sustainability

Human Bocavirus NS1 and NS1-70 Proteins Inhibit TNF-α-Mediated Activation of NF-κB by targeting p65.

Human bocavirus (HBoV), a parvovirus, is a single-stranded DNA etiologic agent causing lower respiratory tract infections in young children worldwide. Nuclear factor kappa B (NF-κB) transcription factors play crucial roles in clearance of invading viruses through activation of many physiological processes. Previous investigation showed that HBoV infection could significantly upregulate the level of TNF-α which is a strong NF-κB stimulator. Here we investigated whether HBoV proteins modulate TNF-α-mediated activation of the NF-κB signaling pathway. We showed that HBoV NS1 and NS1-70 proteins blocked NF-κB activation in response to TNF-α. Overexpression of TNF receptor-associated factor 2 (TRAF2)-, IκB kinase alpha (IKKα)-, IκB kinase beta (IKKβ)-, constitutively active mutant of IKKβ (IKKβ SS/EE)-, or p65-induced NF-κB activation was inhibited by NS1 and NS1-70. Furthermore, NS1 and NS1-70 didn't interfere with TNF-α-mediated IκBα phosphorylation and degradation, nor p65 nuclear translocation. Coimmunoprecipitation assays confirmed the interaction of both NS1 and NS1-70 with p65. Of note, NS1 but not NS1-70 inhibited TNF-α-mediated p65 phosphorylation at ser536. Our findings together indicate that HBoV NS1 and NS1-70 inhibit NF-κB activation. This is the first time that HBoV has been shown to inhibit NF-κB activation, revealing a potential immune-evasion mechanism that is likely important for HBoV pathogenesis

Dental Findings in Cornelia De Lange Syndrome

Cornelia de Lange syndrome is a congenital disease, basically characterized by psychomotor retardation associated with a series of malformations, including mainly skeletal, craniofacial deformities together with gastrointestinal and cardiac malformations. There is no definitive biochemical or chromosomal marker for the prenatal diagnosis of this syndrome. We actually want to present the case of a 10-year-old patient, who was admitted to our clinic for dental pain. The patient had the symptoms of Cornelia de Lange syndrome. During the oral examination of this patient, the patient was found to have the typical symptoms of Cornelia de Lange syndrome, such as micrognathia and delayed eruption in conjunction with the symptoms of the Hutchinson's syndrome, which had never been reported before

Auditory cortical responses in the cat to sounds that produce spatial illusions

Humans and cats can localize a sound source accurately if its spectrum is fairly broad and flat(1-3), as is typical of most natural sounds. However, if sounds are filtered to reduce the width of the spectrum, they result:in illusions of sources that are very different from the actual locations, particularly in the up/down and front/back dimensions(4-6). Such illusions reveal that the auditory system relies on specific characteristics of sound spectra to obtain cues for localization(7). In the-auditory cortex of cats, temporal firing patterns of neurons can signal the locations of broad-band sounds(8-9). Here we show that such spike patterns systematically mislocalize sounds that have been passed through a narrow-band filter. Both correct and incorrect locations signalled by neurons can be predicted quantitatively by a model of spectral processing that also predicts correct and incorrect localization judgements by human listeners(6). Similar cortical mechanisms, if present in humans, could underlie human auditory spatial perception.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/62778/1/399688a0.pd