Effects of anchorage deterioration on the shear behaviour of reinforced concrete half-joint beams

Reinforced concrete half-joint structures, also called dapped-end beams, are a common type of support configuration in bridges and precast structures. They are characterised by a sudden reduction in depth at the end of a suspended structural element. This detail has advantages for design and construction that justified their widespread use in the past. However, there are numerous problems associated with this type of joint that can translate into significant maintenance costs. A recurrent issue is leakage of water and contaminants that cause corrosion of the internal steel reinforcement. The expansive nature of corrosion products can lead to cracking, delamination or complete spalling of the concrete cover. This is detrimental to the anchorage of the reinforcement. The subsequent reduction in load-transfer capacity is difficult to quantify when assessing damaged structures. It can lead to failure modes that are not taken into account by code provisions for new design. Due to the limited understanding of the behaviour of deteriorated half-joints, experimental evidence is necessary to develop new theories and methodologies to assess existing structures accurately. In this study, an experimental programme was carried out on reinforced concrete beam specimens, investigating the effects of anchorage deterioration in the longitudinal tension bars of the full-depth portion of half-joints. Corrosion-induced spalling and delamination were reproduced by casting the beams without cover and reducing the cover/diameter ratio at critical locations. The results indicate that half-joints are vulnerable to anchorage deterioration in the full-depth section. This is due to the absence of direct confining pressure from the end supports. Bond and anchorage degradation led to a progressive reduction in the overall load-bearing capacity of the beam-ends and combined bending-shear failure modes. Nevertheless, the presence of confining vertical reinforcement allowed for some residual anchorage capacity, even in the case of complete loss of cover.EPSRC (EP/M508007/1) EPSRC (EP/N509620/1

Pain-related beliefs among Chinese patients with chronic pain: The construct and concurrent predictive validity of the Chinese version of the survey of pain attitudes-14 (ChSOPA-14)

Context: Pain beliefs as indexed by the Survey of Pain Attitudes (SOPA) have been consistently shown to predict pain adjustment outcomes in Western populations. However, its utility in non-Western populations is unclear. Objectives: We evaluated the construct and predictive validity of the Chinese version of the 14-item SOPA (ChSOPA-14) in a sample of Chinese patients with chronic pain. Methods: A total of 208 Chinese patients with chronic musculoskeletal pain completed the ChSOPA-14, the Chronic Pain Grade questionnaire, the Pain Catastrophizing Scale, the Center for Epidemiological Studies-Depression Scale, and measures of sociodemographic characteristics. Results: Except Medical Cure, all ChSOPA-14 scales were significantly correlated with validity criterion measures (all P < 0.05) in expected directions. The present Chinese sample scored the highest on the Medical Cure scale (mean = 2.98, standard deviation [SD] = 1.05) but the lowest on the Disability scale (mean = 1.75, SD = 1.67). Results of hierarchical multiple regression analyses showed that the ChSOPA-14 scales predicted concurrent depression (F(7,177) = 14.51, P < 0.001) and pain disability (F(7,180) = 8.77, P < 0.001). Pain Control (stdβ [standardized beta coefficient] = -0.13; 95% confidence interval [CI]: -3.41, -0.13; P < 0.05) and Emotion (stdβ = 29; 95% CI: 1.76, 5.02; P < 0.001) emerged as significant independent predictors of concurrent depression whereas Disability (stdβ = 0.19; 95% CI: 1.33, 7.88; P < 0.01), Emotion (stdβ = 16; 95% CI: 0.08, 7.59; P < 0.05), and Solicitude (stdβ = -0.14; 95% CI: -7.05, -0.04; P < 0.05) significantly associated with concurrent disability. Conclusion: The findings offer preliminary evidence for the construct and concurrent predictive validity of the ChSOPA-14. This makes available a suitable instrument for chronic pain in the Chinese population and will facilitate future cross-cultural research on pain beliefs. © 2011 U.S. Cancer Pain Relief Committee Published by Elsevier Inc. All rights reserved.postprin

Preliminary Psychometric Properties of the Chinese Version of the Chronic Pain Coping Inventory (ChCPCI) in a Hong Kong Chinese Population

The Chronic Pain Coping Inventory (CPCI) is a frequently used measure that assesses 8 categories of coping strategies that patients might use to cope with chronic pain. Despite its good psychometric properties and widespread use, the instrument has not been tested for its applicability and validity in non-Western populations, such as among Chinese. This study evaluated the reliability and validity of a Chinese translation of the 42-item CPCI (ChCPCI-42) in a sample of Chinese patients with chronic pain (n = 208). In addition to the ChCPCI-42, the patients were administered the Chronic Pain Grade (CPG) questionnaire, the Pain Catastrophizing Scale (PCS), the Centre for Epidemiological Studies-Depression Scale (CES-D), and questions assessing sociodemographic characteristics. Results of confirmatory factor analyses revealed that of the ChCPCI-42 8 scales, 6 demonstrated acceptable-to-good data-model fit (CFI ≥ 0.90) and 2 demonstrated medium fit (CFI ≥ 0.85). The 8 scales demonstrated adequate to good internal consistency (Cronbach α, 0.69 to 0.79) and correlated with CES-D, PCS, pain intensity, and disability in expected directions. Results of hierarchical multiple regression analyses showed that the ChCPCI-42 scales predicted concurrent depression (F (8,177) = 3.07, P < .01) and pain disability (F (1, 179) = 4.35, P < .001) scores, the Task Persistence scale being the strongest unique predictor among the 8 scales. The findings support the factorial validity and reliability of a 42-item CPCI that can be used among Chinese patients with chronic pain. Perspective: The report outlines the first validation of the CPCI for use in Hong Kong Chinese. This makes available a suitable instrument for chronic pain research in the Southern Chinese population and will help to elucidate similarities and differences in pain coping between Chinese and other ethnic groups. © 2010 American Pain Society.postprin

Adverse lifestyle leads to an annual excess of 2 million deaths in China

published_or_final_versio

Janus monolayers of transition metal dichalcogenides.

Structural symmetry-breaking plays a crucial role in determining the electronic band structures of two-dimensional materials. Tremendous efforts have been devoted to breaking the in-plane symmetry of graphene with electric fields on AB-stacked bilayers or stacked van der Waals heterostructures. In contrast, transition metal dichalcogenide monolayers are semiconductors with intrinsic in-plane asymmetry, leading to direct electronic bandgaps, distinctive optical properties and great potential in optoelectronics. Apart from their in-plane inversion asymmetry, an additional degree of freedom allowing spin manipulation can be induced by breaking the out-of-plane mirror symmetry with external electric fields or, as theoretically proposed, with an asymmetric out-of-plane structural configuration. Here, we report a synthetic strategy to grow Janus monolayers of transition metal dichalcogenides breaking the out-of-plane structural symmetry. In particular, based on a MoS2 monolayer, we fully replace the top-layer S with Se atoms. We confirm the Janus structure of MoSSe directly by means of scanning transmission electron microscopy and energy-dependent X-ray photoelectron spectroscopy, and prove the existence of vertical dipoles by second harmonic generation and piezoresponse force microscopy measurements

“It’s just a theory”: trainee science teachers’ misunderstandings of key scientific terminology

Background: This article presents the findings from a survey of 189 pre-service science teachers who were asked to provide definitions of key scientific terms ('theory'; 'fact'; 'law'; 'hypothesis'). The survey was a scoping and mapping exercise to establish the range and variety of definitions. Methods: Graduates on a pre-service science teacher training course were asked to complete a short, free response survey and define key science terminology a >95% response rate was achieved and respondents definitions were categorised according to a best fit model. Results: In some cases, definitions contrary to accepted scientific meanings were given. In other cases, terminology was defined in a wholly non-scientific way, e.g., one-fifth of the respondents defined a ‘law’ in the context of rules that govern society rather than in a scientific context. Science graduates’ definitions and their understanding of key terminology is poor despite their study of science in formal university settings (with many respondents being recent science graduates). Conclusions: Key terminology in science, such as 'theory', 'law', 'fact', 'hypothesis', tends not to be taught and defined with consideration for the differences in meaning that different audiences/users give to them. This article calls for better instruction for pre-service science teachers’ in the importance of accurate and precise definitions of key science terminology in order to better differentiate between the scientific and colloquial usage of key terms

Oxy-fuel combustion of coal and biomass blends

The ignition temperature, burnout and NO emissions of blends of a semi-anthracite and a high-volatile bituminous coal with 10 and 20 wt.% of olive waste were studied under oxy-fuel combustion conditions in an entrained flow reactor (EFR). The results obtained under several oxy-fuel atmospheres (21%O2–79%CO2, 30%O2–70%CO2 and 35%O2–65%CO2) were compared with those attained in air. The results indicated that replacing N2 by CO2 in the combustion atmosphere with 21% of O2 caused an increase in the temperature of ignition and a decrease in the burnout value. When the O2 concentration was increased to 30 and 35%, the temperature of ignition was lower and the burnout value was higher than in air conditions. A significant reduction in ignition temperature and a slight increase in the burnout value was observed after the addition of biomass, this trend becoming more noticeable as the biomass concentration was increased. The emissions of NO during oxy-fuel combustion were lower than under air-firing. However, they remained similar under all the oxy-fuel atmospheres with increasing O2 concentrations. Emissions of NO were significantly reduced by the addition of biomass to the bituminous coal, although this effect was less noticeable in the case of the semi-anthracite.This work was carried out with financial support from the Spanish MICINN (Project PS-120000-2005-2) co-financed by the European Regional Development Fund. M.V.G. and L.A. acknowledge funding from the CSIC JAE-Doc and CSIC JAE-Pre programs, respectively, co-financed by the European Social Fund. J.R. acknowledges funding from the Government of the Principado de Asturias (Severo Ochoa program).Peer reviewe

Large genomic rearrangements in the CFTR gene contribute to CBAVD

<p>Abstract</p> <p>Background</p> <p>By performing extensive scanning of whole coding and flanking sequences of the <it>CFTR (Cystic Fibrosis Transmembrane Conductance Regulator</it>) gene, we had previously identified point mutations in 167 out of 182 (91.7%) males with isolated congenital bilateral absence of the vas deferens (CBAVD). Conventional PCR-based methods of mutation analysis do not detect gross DNA lesions. In this study, we looked for large rearrangements within the whole <it>CFTR </it>locus in the 32 CBAVD patients with only one or no mutation.</p> <p>Methods</p> <p>We developed a semi-quantitative fluorescent PCR assay (SQF-PCR), which relies on the comparison of the fluorescent profiles of multiplex PCR fragments obtained from different DNA samples. We confirmed the gross alterations by junction fragment amplification and identified their breakpoints by direct sequencing.</p> <p>Results</p> <p>We detected two large genomic heterozygous deletions, one encompassing exon 2 (c.54-5811_c.164+2186del8108ins182) [or <it>CFTRdele2</it>], the other removing exons 22 to 24 (c.3964-3890_c.4443+3143del9454ins5) [or <it>CFTRdele 22_24</it>], in two males carrying a typical CBAVD mutation on the other parental <it>CFTR </it>allele. We present the first bioinformatic tool for exon phasing of the <it>CFTR </it>gene, which can help to rename the exons and the nomenclature of small mutations according to international recommendations and to predict the consequence of large rearrangements on the open reading frame.</p> <p>Conclusion</p> <p>Identification of large rearrangements further expands the <it>CFTR </it>mutational spectrum in CBAVD and should now be systematically investigated. We have designed a simple test to specifically detect the presence or absence of the two rearrangements identified in this study.</p

Accurately Measuring Recombination between Closely Related HIV-1 Genomes

Retroviral recombination is thought to play an important role in the generation of immune escape and multiple drug resistance by shuffling pre-existing mutations in the viral population. Current estimates of HIV-1 recombination rates are derived from measurements within reporter gene sequences or genetically divergent HIV sequences. These measurements do not mimic the recombination occurring in vivo, between closely related genomes. Additionally, the methods used to measure recombination make a variety of assumptions about the underlying process, and often fail to account adequately for issues such as co-infection of cells or the possibility of multiple template switches between recombination sites. We have developed a HIV-1 marker system by making a small number of codon modifications in gag which allow recombination to be measured over various lengths between closely related viral genomes. We have developed statistical tools to measure recombination rates that can compensate for the possibility of multiple template switches. Our results show that when multiple template switches are ignored the error is substantial, particularly when recombination rates are high, or the genomic distance is large. We demonstrate that this system is applicable to other studies to accurately measure the recombination rate and show that recombination does not occur randomly within the HIV genome