Computer simulation in conjunction with medical thermography as an adjunct tool for early detection of breast cancer

BACKGROUND: Mathematical modelling and analysis is now accepted in the engineering design on par with experimental approaches. Computer simulations enable one to perform several 'what-if' analyses cost effectively. High speed computers and low cost of memory has helped in simulating large-scale models in a relatively shorter time frame. The possibility of extending numerical modelling in the area of breast cancer detection in conjunction with medical thermography is considered in this work. METHODS: Thermography enables one to see the temperature pattern and look for abnormality. In a thermogram there is no radiation risk as it only captures the infrared radiation from the skin and is totally painless. But, a thermogram is only a test of physiology, whereas a mammogram is a test of anatomy. It is hoped that a thermogram along with numerical modelling will serve as an adjunct tool. Presently mammogram is the 'gold-standard' in breast cancer detection. But the interpretation of a mammogram is largely dependent on the radiologist. Therefore, a thermogram that looks into the physiological changes in combination with numerical simulation performing 'what-if' analysis could act as an adjunct tool to mammography. RESULTS: The proposed framework suggested that it could reduce the occurrence of false-negative/positive cases. CONCLUSION: A numerical bioheat model of a female breast is developed and simulated. The results are compared with experimental results. The possibility of this method as an early detection tool is discussed

In vitro multiplication of the rare and endangered slipper orchid, Paphiopedilum rothschildianum (Orchidaceae)

Paphiopedilum rothschildianum is an endangered orchid species endemic to Mount Kinabalu, Sabah, and Malaysia. The vegetative propagation of this plant has always been restricted due to its slow growth and maturation rates. Thus, an in vitro tissue culture technique was explored in order to overcome this limitation. In this study, clonal propagation of P. rothschildianum was achieved through in vitro formation of multiple shoots from stem nodal and single shoot explants cultured onto halfstrength Murashige and Skoog medium. The responses of the explants to the presence of different types of organic nitrogen additives viz. casein hydrolysate, peptone and tryptone-peptone (in amount of 0.5, 1.0 and 2.0 g/l) in the culture medium were also evaluated. The addition of these organic nitrogen additives into the basal medium slightly enhanced the number of multiple shoots formed on both types of explants when compared to additive-free MS medium. After 16 weeks of culture, an average of 2.9 shoots per stem nodal explant and 2.8 shoots per single shoot explant were obtained on half-strength MS medium supplemented with 1.0 g/l peptone and 2.0 g/l tryptone-peptone, respectively. All the newly-formed shoots were divided into single plantlets and subcultured onto similar respective medium. After an additional 12 weeks of culture on the same medium, plantlets with 3 - 4 roots were acclimatized and transferred to a glass house where they showed 90% survival rate. Thus, the method presented in this study had provided a promising strategy for the production of large numbers of phenotypically stable P. rothschildianum

Benchmarking 2D hydraulic models for urban flood simulations

This paper describes benchmark testing of six two-dimensional (2D) hydraulic models (DIVAST, DIVASTTVD, TUFLOW, JFLOW, TRENT and LISFLOOD-FP) in terms of their ability to simulate surface flows in a densely urbanised area. The models are applied to a 1·0 km × 0·4 km urban catchment within the city of Glasgow, Scotland, UK, and are used to simulate a flood event that occurred at this site on 30 July 2002. An identical numerical grid describing the underlying topography is constructed for each model, using a combination of airborne laser altimetry (LiDAR) fused with digital map data, and used to run a benchmark simulation. Two numerical experiments were then conducted to test the response of each model to topographic error and uncertainty over friction parameterisation. While all the models tested produce plausible results, subtle differences between particular groups of codes give considerable insight into both the practice and science of urban hydraulic modelling. In particular, the results show that the terrain data available from modern LiDAR systems are sufficiently accurate and resolved for simulating urban flows, but such data need to be fused with digital map data of building topology and land use to gain maximum benefit from the information contained therein. When such terrain data are available, uncertainty in friction parameters becomes a more dominant factor than topographic error for typical problems. The simulations also show that flows in urban environments are characterised by numerous transitions to supercritical flow and numerical shocks. However, the effects of these are localised and they do not appear to affect overall wave propagation. In contrast, inertia terms are shown to be important in this particular case, but the specific characteristics of the test site may mean that this does not hold more generally

Anti-tumor efficacy of recombinant human arginase in combination with chemotherapeutic agents in human hepatocellular carcinoma

Poster Session 1: Translational & Clinical: no.41published_or_final_versionThe 16th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 22 January 2011. In Hong Kong Medical Journal, 2011, v. 17, suppl. 1, p. 23, abstract no. 2

The evolution of trait correlations constrains phenotypic adaptation to high CO2 in a eukaryotic alga

Microbes form the base of food webs and drive biogeochemical cycling. Predicting the effects of microbial evolution on global elemental cycles remains a significant challenge due to the sheer number of interacting environmental and trait combinations. Here, we present an approach for integrating multivariate trait data into a predictive model of trait evolution. We investigated the outcome of thousands of possible adaptive walks parameterized using empirical evolution data from the alga Chlamydomonas exposed to high CO2. We found that the direction of historical bias (existing trait correlations) influenced both the rate of adaptation and the evolved phenotypes (trait combinations). Critically, we use fitness landscapes derived directly from empirical trait values to capture known evolutionary phenomena. This work demonstrates that ecological models need to represent both changes in traits and changes in the correlation between traits in order to accurately capture phytoplankton evolution and predict future shifts in elemental cycling

Growth and Self-Ejection of Single Condensate Droplet on Nanostructured Microcones

In the last decade, the phenomenon of coalescence-induced droplet jumping has been studied in depth because of the advantages it brings in applications such as anti-frosting, anti-icing, condensation heat transfer, water harvesting, thermal diodes for electronics cooling and self-cleaning [1]. In this work we theoretically and experimentally show that surfaces structured with micro truncated cones covered with highly hydrophobic nanostructures exhibit a recurrent self-ejection of single condensate droplets in addition to the common coalescence-induced jumps. We analytically modelled the external forces acting both on a droplet of condensate slowly growing in conical pores (a simplification of the growth between truncated cones) and during the following rapid transient for two possible cases of self-ejection: 1) rapid swelling out of the structures and 2) detachment from a pinning site (a less hydrophobic defect or the nucleation site). Viscous and adhesion dissipations were included in the modelling. We described the shape of the growing droplet as a function of the tapering (B) and of dynamic contact angles (vadv and vrec ). For both cases, the minimum requirement for self-ejection is that the receding angle of the walls (vrec ) and any pinning site (vpinningrec ) are greater than 90°+B. In the first case, as the volume increases, the upper meniscus moves towards the apex of the cones and the lower one follows it as soon as it reaches vrec; when the droplet reaches the apex of the structures it self-ejects because the superior meniscus expands rapidly and a Laplace pressure gradient is generated between the menisci. In the second case, the superior meniscus grows towards the apex and when the lower one recedes from the pinning site, the droplet self-ejects due to the Laplace pressure gradient generated by the abrupt change in wettability, as recently reported for relatively large droplets (radius > 50 μm) in diverging grooves [2]. Describing growth and self-ejection with a system of forces requires a careful distinction between external and internal forces. The modelling with forces, unlike the energetic one [2], allowed us to describe the ejection transient dynamics and to derive the ejection velocity while maintaining the dependence on the dynamic contact angles of the superhydrophobic walls and of an eventual pinning site, fundamental quantities for the design of real surfaces. The analytical results relative to the case of the pinning site foresee that, at a fixed contact angle hysteresis of the superhydrophobic walls and vpinningrec, the ejection velocity increases with B (until the limit B = vpinningrec − 90°, beyond which there cannot be ejection); in addition, the velocity is greater as the droplet size decreases if viscous dissipations are not considered while a peak trend is observed with the dissipations included. We fabricated silicon truncated micro cones arranged in square and hexagonal patterns and covered with nanostructures. Through condensation experiments in a controlled environmental chamber we observed for the first time the self-ejection of the drops that nucleate and grow between the cones (in the case in question the droplet diameter ≈ 11 um). By fabricating cones of different sizes, we have also studied the self-ejection rate per unit area as a function of the droplet size. Furthermore, we performed preliminary condensation frosting experiments. Future investigations of this new class of jumping droplet surfaces may show important advantages in the mentioned applications

Multivariate trait analysis reveals diatom plasticity constrained to a reduced set of biological axes

AbstractTrait-based approaches to phytoplankton ecology have gained traction in recent decades as phenotypic traits are incorporated into ecological and biogeochemical models. Here, we use high-throughput phenotyping to explore both intra- and interspecific constraints on trait combinations that are expressed in the cosmopolitan marine diatom genus Thalassiosira. We demonstrate that within Thalassiosira, phenotypic diversity cannot be predicted from genotypic diversity, and moreover, plasticity can create highly divergent phenotypes that are incongruent with taxonomic grouping. Significantly, multivariate phenotypes can be represented in reduced dimensional space using principal component analysis with 77.7% of the variance captured by two orthogonal axes, here termed a ‘trait-scape’. Furthermore, this trait-scape can be recovered with a reduced set of traits. Plastic responses to the new environments expanded phenotypic trait values and the trait-scape, however, the overall pattern of response to the new environments was similar between strains and many trait correlations remained constant. These findings demonstrate that trait-scapes can be used to reveal common constraints on multi-trait plasticity in phytoplankton with divergent underlying phenotypes. Understanding how to integrate trait correlational constraints and trade-offs into theoretical frameworks like biogeochemical models will be critical to predict how microbial responses to environmental change will impact elemental cycling now and into the future.</jats:p

Experimental and DFT Insights on Microflower g-C3N4/BiVO4 Photocatalyst for Enhanced Photoelectrochemical Hydrogen Generation from Lake water

This is the author accepted manuscript. The final version is available from the American Chemical Society via the DOI in this recordHerein, an experimental and Density Functional Theory (DFT) analysis of the composite g-C3N4/BiVO4 microflower photocatalysts were comprehensively discussed. A remarkable photoelectrocatalytic solar hydrogen production has been observed for the as-developed photocatalysts, with different loading amounts of g-C3N4 (0.1, 0.4, 0.8, and 1.2 wt.%), using lake water without the addition of sacrificial reagents. The 0.8 wt.% g-C3N4/BiVO4 microflower photocatalyst evinced remarkable photoelectrocatalytic activity of 21.4 mmol/h of hydrogen generated in comparison to other samples with an AQE of 4.27% at 420 nm. In addition, the photocurrent density of 0.8 wt.% g-C3N4/BiVO4 microflower was two-fold higher than that of pure BiVO4. This was attributed to its better crystallinity and optical properties; confirmed from XRD and DR-UV-Vis analysis. The DFT analysis further corroborated that the efficient photocharge carrier separation and limited photocharge carrier recombination corresponded to the synergistic effect of the band offset and built-in electric field.Murata Science FoundationYayasan Universiti Teknolog

Decreasing Prevalence of the Full Metabolic Syndrome but a Persistently High Prevalence of Dyslipidemia among Adult Arabs

A decade has passed since metabolic syndrome (MetS) was documented to be highly prevalent in the kingdom of Saudi Arabia. No follow-up epidemiologic study was done. This study aims to fill this gap. In this cross-sectional, observational study, a total of 2850 randomly selected Saudi adults aged 18–55 years were recruited. Subjects' information was generated from a database of more than 10,000 Saudi citizens from the existing Biomarkers Screening in Riyadh Program (RIYADH Cohort), Saudi Arabia. Anthropometrics included body mass index (BMI), blood pressure, as well as waist and hip circumferences. Fasting blood glucose and lipid profile were determined using routine laboratory procedures. The definition of ATP-III (NHANES III) was used for the diagnosis of the full MetS. The overall prevalence of complete MetS was 35.3% [Confidence-Interval (CI) 33.5–37.01]. Age-adjusted prevalence according to the European standard population is 37.0%. Low HDL-cholesterol was the most prevalent of all MetS risk factors, affecting 88.6% (CI 87.5–89.7) and hypertriglyceridemia the second most prevalent, affecting 34% (CI 32.3–35.7) of the subjects. The prevalence of the full MetS decreased from previous estimates but remains high, while dyslipidemia remains extremely high, affecting almost 90% of middle-aged Arabs. Screening for dyslipidemia among Saudi adults is warranted, especially among those most at risk. Scientific inquiry into the molecular causes of these manifestations should be pursued as a first step in the discovery of etiologic therapies