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Improved plasticity models require simultaneous experimental local strain and microstructural evolution data. Microscopy tools, such as electron backscatter diffraction (EBSD), that can monitor transformation at the relevant length-scale, are often incompatible with digital image correlation (DIC) techniques required to determine local deformation. In this paper, the viability of forescatter detector (FSD) images as the basis for the DIC study is investigated. Standard FSD and an integrated EBSD/FSD approach (Pattern Region of Interest Analysis System: PRIAS™) are analyzed. Simultaneous strain and microstructure maps are obtained for tensile deformation of Q&P 1180 steel up to ~14% strain. Tests on an undeformed sample that is simply shifted indicate a standard deviation of error in strain of around 0.4% without additional complications from a deformed surface. The method resolves strain bands at ~2 μm spacing but does not provide significant sub-grain strain resolution. Similar resolution was obtained for mechanically polished and electropolished samples, despite electropolished surfaces presenting a smoother, simpler topography. While the resolution of the PRIAS approach depends upon the EBSD step size, the 80 nm step size used provides seemingly similar resolution as 8,000× (22.7 nm) FSD images. Surface feature evolution prevents DIC analysis across large strain steps (>6% strain), but restarting DIC, using an FSD reference image from an interim strain step, allows reasonable DIC across the stress–strain curve. Furthermore, the data are obtained easily and provide complementary information for EBSD analysis.
The above article previously published with incorrect author information for Dr Binil Aryal. Dr Aryal’s affiliation should be listed as Central Department of Physics, Tribhuvan University, Kathmandu, Nepal. This error has since been rectified in the online PDF and HTML copies of the article.
To compare endoscopic assisted powered adenoidectomy with conventional curettage adenoidectomy.
A randomised controlled trial was conducted at a tertiary care teaching hospital. Fifty patients with a symptom complex pertaining to adenoid hypertrophy and requiring adenoidectomy were chosen and divided into 2 groups of 25 each. Patients in group A underwent conventional curettage adenoidectomy and those in group B underwent endoscopic assisted powered adenoidectomy. Comparison was based on the parameters of surgical time, intra-operative bleeding, post-operative pain and completeness of adenoid removal.
The surgical time was significantly longer with the powered instrument. Mean blood loss was greater in the powered group, but was statistically insignificant. The powered procedure fared significantly better, with lower pain scores and more instances of complete tissue resection.
A curved microdebrider blade can be used safely and precisely for adenoidectomy under endoscopic vision. It enables complete resection of adenoid tissue. This method also proves to be an excellent teaching aid.
Many studies have identified changes in the brain associated with obsessive–compulsive disorder (OCD), but few have examined the relationship between genetic determinants of OCD and brain variation.
We present the first genome-wide investigation of overlapping genetic risk for OCD and genetic influences on subcortical brain structures.
Using single nucleotide polymorphism effect concordance analysis, we measured genetic overlap between the first genome-wide association study (GWAS) of OCD (1465 participants with OCD, 5557 controls) and recent GWASs of eight subcortical brain volumes (13 171 participants).
We found evidence of significant positive concordance between OCD risk variants and variants associated with greater nucleus accumbens and putamen volumes. When conditioning OCD risk variants on brain volume, variants influencing putamen, amygdala and thalamus volumes were associated with risk for OCD.
These results are consistent with current OCD neurocircuitry models. Further evidence will clarify the relationship between putamen volume and OCD risk, and the roles of the detected variants in this disorder.
Declaration of interest
The authors have declared that no competing interests exist.
This paper investigates the synergies and trade-offs between passive aeroelastic tailoring and adaptive aeroelastic deformation of a transport composite wing for fuel burn minimisation. This goal is achieved by optimising thickness and stiffness distributions of constitutive laminates, jig-twist shape and distributed control surface deflections through different segments of a nominal “cruise-climb” mission. Enhanced aerostructural efficiency is sought both passively and adaptively as a means of aerodynamic load redistribution, which, in turn, is used for manoeuvre load relief and minimum drag dissipation. Passive shape adaptation is obtained by embedding shear-extension and bend-twist couplings in the laminated wing skins. Adaptive camber changes are provided via full-span trailing-edge flaps. Optimised design solutions are found using a bi-level approach that integrates gradient-based and particle swarm optimisations in order to tailor structural properties at rib-bay level and retrieve blended stacking sequences. Performance benefits from the combination of passive aeroelastic tailoring with adaptive control devices are benchmarked in terms of fuel burn and a payload-range efficiency. It is shown that the aeroservoelastically tailored composite design allows for significant weight and fuel burn improvements when compared to a similar all-metallic wing. Additionally, the trailing-edge flap augmentation can extend the aircraft performance envelope and improve the overall cruise span efficiency to nearly optimal lift distributions.
Perovskite materials are sensitive to environmental conditions. Here we report the synthesis and characterization of a hydrophobic alkylammonium lead(II) iodide perovskite with enhanced stability in water. Water stability was achieved by growing a shell of 4-[(N-3-butyne)carboxyamido]anilinium lead(II) iodide over methylammonium lead(II) iodide. As a proof of concept, the water-splitting reaction was performed using our new material coated on TiO2, and a 7-fold increase in applied bias photon-to-current efficiency was observed as compared with standard p25-TiO2. Such simple and versatile chemical modification to induce high water stability is useful toward exploring new applications for the perovskite materials.
An outbreak of gastroenteritis affected 453 attendees (attack rate 28·5%) of six separate events held at a hotel in Singapore. Active case detection, case-control studies, hygiene inspections and microbial analysis of food, environmental and stool samples were conducted to determine the aetiology of the outbreak and the modes of transmission. The only commonality was the food, crockery and cutlery provided and/or handled by the hotel's Chinese banquet kitchen. Stool specimens from 34 cases and 15 food handlers were positive for norovirus genogroup II. The putative index case was one of eight norovirus-positive food handlers who had worked while they were symptomatic. Several food samples and remnants tested positive for Escherichia coli or high faecal coliforms, aerobic plate counts and/or total coliforms, indicating poor food hygiene. This large common-source outbreak of norovirus gastroenteritis was caused by the consumption of contaminated food and/or contact with contaminated crockery or cutlery provided or handled by the hotel's Chinese banquet kitchen.
Single walled carbon nanotubes (SWNTs) possess unique structural and functional properties. Their ability to be functionalized with different biomolecules makes them excellent candidates for biomedical applications like targeted drug delivery and cancer diagnostics. However, prior to use in therapeutic applications, biocompatibility of SWNTs needs to be thoroughly investigated. Blood is a living tissue and contains cells which can potentially interact with SWNTs during the drug delivery process. The interaction of leukocytes in blood with the SWNTs can provide information regarding the immune response of the host to the nanotubes. Here, we evaluated the acute immune response of leukocytes in blood to SWNTs via (a) direct interaction, due to the presence of SWNTs in circulation and (b) indirect interaction, due to the presentation of SWNTs to leukocytes via antigen presenting cells. These SWNTs were non-covalently functionalized with single stranded DNA (ss-DNA) that acts as a surfactant for suspending SWNTs in aqueous solutions and also serves as a backbone for attaching and transporting different biomolecules. Isolation of cells from blood was done using density gradient centrifugation. Early activation markers were used to study the activation of different leukocyte subpopulations and any activation results in changes of these markers. Flow cytometry was done to analyze the different subpopulations. Results of our study demonstrated that ss-DNA functionalized SWNTs do not elicit an immune response from leukocytes in blood via direct or indirect interaction. This intensive study demonstrates the biocompatibility of single walled carbon nanotubes and paves the way for their safe use in drug delivery and cancer therapeutics without cytotoxicity.
There is an increasing need for integrating high dielectric constant ceramic thin film components in organic and 3D IC packages to lower the power-supply impedance at high frequencies and supply noise-free power to the ICs. Sol-gel approach is very attractive for high density capacitors because of its ability to precisely control the composition of the films and the ease of introducing dopants to engineer the dielectric properties such as breakdown voltages and DC leakage characteristics. Thin films on copper foils lend themselves to organic package integration with standard foil lamination techniques used in package build-up processes. However, fabrication of thin film barium titanate on copper foils is generally affected by process incompatibility during crystallization in reducing atmospheres, leading to poor crystallization, oxygen vacancies and copper diffusion through the film that degrades the electrical properties.
This paper focuses on the dielectric properties and electrical reliability of thin films on copper foils. Thin film (300-400 nm) embedded capacitors with capacitance density of 2 μF/cm2, low leakage current and high breakdown voltage were fabricated via sol-gel technology and foil lamination. To lower the leakage current, the chemical composition was altered by incorporating – 1.) Excess barium 2.) Acceptor dopants such as Mn. Both approaches lowered the leakage current compared to that of pure barium titanate. SEM analysis showed enhanced densification and refined grain structure with chemistry modification. The films showed good stability in leakage currents at 150 C with an applied field strength of 100 kV/cm, demonstrating the electrical reliability of these films.
Semiconducting oxides are widely known and commercially applied for their gas sensing properties. However, biochemical sensing has mostly depended on optical and electrochemical techniques that are more cumbersome. This work investigates the biosensing characteristics of ZnO nanobelts and ZnO thin films. Zinc oxide thin film sensors showed changes in conductivity after protein functionalization with rabbit IgG and hybridization with anti-rabbit IgG. Conductivity changes were also measured after coating the oxides with MCF-7 cancer cells and its antibodies. In another set of experiments, ZnO nanobelts showed systematic conductivity changes with rabbit IgG protein hybridization. The experimental results in this paper indicate that the conductimetric properties of nano and thin film oxides can be sensitized to protein and cancer cell hybridization reactions. This technique can also be applied to certain other pathogen proteins or toxic proteins from the environment leading to low-cost miniaturized wireless biosensors.
This paper reports the results of the aerosol lidar experiments that have been performed at the Indian Institute of Tropical Meteorology (IITM), Pune (18.54°N, 73.85°E, 559 m amsl), a tropical station in India. The lidar-observed cloud macro-physical parameters (cloud-base and cloud-ceiling heights, vertical thickness, etc.) and polarisation characteristics and their association with surface-generated aerosols at the experimental site are presented and discussed. The correspondence among the lidar-derived aerosol distributions, meteorological parameters and south-west (SW) monsoon (June-September) activity over Pune during 12 successive SW monsoon seasons (1987-98) including two pairs of contrasting seasons of 1987-8 and 1993-4 is also examined. The results indicate an association between variations in aerosol loading in the boundary layer during the pre-monsoon season (March-May) and precipitation intensity during the ensuing monsoon season. Moreover, the decrease in aerosol content from pre-monsoon to monsoon season is found to follow the SW monsoon season total precipitation. Thus the results suggest that (i) the IITM lidar can also be a useful remote sensor for aerosol characterisation studies from polarisation measurements, and some important physical properties of clouds in the lower atmosphere over the station, and (ii) there exists a correspondence between boundary-layer aerosol content and SW monsoon precipitation over Pune, which is explained in terms of the type of aerosols and the environmental and meteorological processes, particularly during pre-monsoon and monsoon months prevailing over the experimental station.
Fe availability is critical for optimal lymphocyte proliferation; however, the minimum required levels are unknown. Such information is valuable when assessing in vitro immune responses in Fe-deficient subjects, because serum (Fe) added to the culture medium may replete lymphocytes. To address this issue, splenic lymphocytes obtained from seventeen 3-month-old C57BL/6 mice were incubated without and with 1 mg/l concanavalin A or 50 μg/l anti-CD3 antibody in media that contained between 0·113 and 9·74 μmol Fe/l. Fe was provided by either fetal calf serum (FCS, 0–100 ml/l), newborn calf serum (NBCS, 0–100 ml/l), or NBCS (10 ml/l) plus ferric ammonium citrate. As expected, the rate of DNA synthesis increased with Fe levels (P<0·01). Maximum DNA synthesis was obtained with 2·26 μmol Fe/l (50 ml FCS/l) for concanavalin A and 0·895 μmol/l (20 ml FCS/l) for anti-CD3-treated cells. In serum-free media (0·113 μmol Fe/l), the proliferative responses to concanavalin A were below the background, while they rose 5·5-fold in anti-CD3-treated cells (P<0·05). In apotransferrin-supplemented media (0·13 μmol Fe/l), the proliferative responses to concanavalin A and anti-CD3 antibody were 18·6 and 71 %, respectively, of that obtained with 4·66 μmol Fe/l (100 ml FCS/l). Interleukin 2 secretion also followed the same trend as lymphocyte proliferation. Since differences between both mitogens persisted after FCS was substituted with NBCS, we can rule out an effect on ribonucleotide reductase activity, or by other serum growth factors. We speculate an Fe effect at an early step of T-cell activation. Data suggest that the minimum Fe concentration required for lymphocyte proliferation varies with the mitogen.
We present the case of a 50-year-old man who developed bilateral cortical blindness and confusion following a seemingly uneventful right-sided radical neck dissection. Computed tomography (CT) scans confirmed bilateral occipital lobe infarctions.
To our knowledge, there are no previously documented reports of this clinical event following head and neck surgical procedures. Although this is a rare occurrence, otolaryngologists should be aware of this potential post-operative complication.
The possible aetiologies of this condition are discussed.
Green revolution technologies of the 1960s and 1970s have led to the emergence of rice (Oryza sativa)–wheat (Triticum aestivum) (R–W) as a major cropping system in the Indo-Gangetic Plains (IGP). Expansion of irrigation through a network of canals and privately owned tube wells was one of the key factors in the success of the new technologies. Since canal water supplies are not demand-driven, farmers increasingly relied on the use of ground water by installing shallow tube wells. The strategy of ground water development and its use in conjunction with canal supplies paid rich dividends in control of waterlogging and secondary alkalization and in increasing the pace of alkali soils reclamation programmes in areas underlaid with fresh quality aquifers. Rice–wheat systems were the preferred choice of farmers. Adoption of the R–W system, however, changed the salt and water balance in north-western parts of the IGP. In the north-east of Punjab and Haryana states it led to receding water tables and waterlogging, and in south-west parts to associated problems of secondary salination. In eastern parts of the IGP in West Bengal, development of ground water aquifers to meet irrigation water requirements for the intensification and diversification of agriculture has led to serious problems of ground water contamination due to dissolution of arsenic-bearing minerals under altered soil moisture regimes, conducive to oxidation of pyritic sediments. These experiences suggest that there is an urgent need for a change in the way food is produced in the IGP for sustainability of the natural resource base. This will depend on the ability to predict long-term consequences of intensification and diversification of agriculture on the farm and regional scale. Whereas issues of favourable regional salt and water balances need attention in the north-west of the IGP, rain-water management and alleviating drainage congestion can facilitate the adoption of agricultural technologies and improve productivity of the R–W systems.
Twenty-six adult cystic fibrosis patients were studied to compare nasal disease with their laboratory correlates including skin testing, immunoglobulin and Aspergillus fumigatus precipitin levels, saccharin testing and sputum cultures. Six patients were asymptomatic and all of these had negative skin tests, normal IgE levels and negative Aspergillus fumigatus precipitins. Thirteen patients had rhinitis, 12 had positive skin-testing for common allergens, 10 elevated IgE levels and nine positive Aspergillus fumigatus precipitins. Seven patients had polyps, all had normal IgE levels and negative Aspergillus fumigatus precipitins, six had positive skin testing for common allergens. There also appeared to be a relationship between Pseudomonas spp. colonization and positive skin testing.