Low temperature specific heat of vanadium carbide

Low temperature specific heat measurements on vanadium carbide crystal

Design and parallelisation of a miniature photobioreactor platform for microalgal culture evaluation and optimisation

Miniature photobioreactors (mPBr) represent a potential platform technology for the high-throughput, phototrophic cultivation of microalgae. This work describes the development and characterisation of a novel orbitally shaken twin-well mPBr, and its scale-out to a 24-well microplate format, suitable for optimisation of microalgae culture conditions. Fluid hydrodynamics, oxygen mass transfer coefficient (kLa) and light intensity distribution in the mPBr were first investigated as a function of orbital shaking frequency. High speed video analysis of the shaken wells indicated rapid fluid flow and good mixing while measured kLa values varied between 20 and 80 h−1. Light intensity variation across the scaled-out platform was in the range ±20 μmol m−2 s−1. The use of the mPBr platform was demonstrated for optimisation of conditions for the batch cultivation of Chlorella sorokiniana. Using a modified tris-base phosphate (TBP) medium, the highest biomass concentration and productivity achieved were 9.2 g L−1 and 2.5 ± 0.2 g L−1 d−1 respectively at 5% CO2 with a light intensity of 380 μmol m−2 s−1. In general, cell growth rate and yield increased with increasing shaking frequency (up to 300 rpm) while culture conditions had limited impact on pigment production. Overall, these results demonstrate the application of the mPBr for rapid optimisation of phototrophic culture conditions and establishment of high cell density cultures

High-speed Civil Transport Aircraft Emissions

Estimates are given for the emissions from a proposed high speed civil transport (HSCT). This advanced technology supersonic aircraft would fly in the lower stratosphere at a speed of roughly Mach 1.6 to 3.2 (470 to 950 m/sec or 920 to 1850 knots). Because it would fly in the stratosphere at an altitude in the range of 15 to 23 km commensurate with its design speed, its exhaust effluents could perturb the chemical balance in the upper atmosphere. The first step in determining the nature and magnitude of any chemical changes in the atmosphere resulting from these proposed aircraft is to identify and quantify the chemically important species they emit. Relevant earlier work is summarized, dating back to the Climatic Impact Assessment Program of the early 1970s and current propulsion research efforts. Estimates are provided of the chemical composition of an HSCT's exhaust, and these emission indices are presented. Other aircraft emissions that are not due to combustion processes are also summarized; these emissions are found to be much smaller than the exhaust emissions. Future advances in propulsion technology, in experimental measurement techniques, and in understanding upper atmospheric chemistry may affect these estimates of the amounts of trace exhaust species or their relative importance

Test of the quantumness of atom-atom correlations in a bosonic gas

It is shown how the quantumness of atom-atom correlations in a trapped bosonic gas can be made observable. Application of continuous feedback control of the center of mass of the atomic cloud is shown to generate oscillations of the spatial extension of the cloud, whose amplitude can be directly used as a characterization of atom-atom correlations. Feedback parameters can be chosen such that the violation of a Schwarz inequality for atom-atom correlations can be tested at noise levels much higher than the standard quantum limit

Assessment of survival and cardiotoxicity of adjuvant trastuzumab among HER2 breast cancer patients in an oncology centre in Malaysia / Harissa H Hasbullah … [et al.]

Adjuvant trastuzumab has been used in human epidermal growth factor-2 (HER2) breast cancer to improve survival but with concern of cardiotoxicity. Our study is the first to review efficacy and toxicity of adjuvant trastuzumab in Malaysia. Methods: This is a retrospective cohort study on HER2 non metastatic breast cancer patients in University Malaya Medical Centre diagnosed between October 2006 and May 2011. Two cohorts were created based on whether or not they received adjuvant trastuzumab. Disease free survival (DFS) and overall survival (OS) for both groups were estimated using Kaplan Meier method and compared using Log rank test. Cox proportional hazards regression models analysed for potential covariates of age, tumour size and grade, node and estrogen receptor (ER) status. Trastuzumab cardiotoxicity was defined as left ventricular systolic dysfunction or heart failure with or without symptoms and graded using Common Terminology Criteria for Adverse Events (CTCAE 4.0). Results: 170 HER2 non metastatic breast cancer patients were identified. Thirty-three received trastuzumab and 136 did not. Median age was 53.4 ± 10.3 years old. Significantly more ER negative patients received trastuzumab. Four years DFS in ‘trastuzumab’ versus ‘no trastuzumab’ cohort was 90.9% vs 74.5% (p = 0.027). Four years OS was 91% vs 84.7% (p = 0.30) respectively. Majority tolerated trastuzumab with no toxicity. Five patients (15.2%) experienced cardiotoxicity (all grade I).Conclusions: Adjuvant trastuzumab significantly improved DFS in HER2 breast cancer. Treatment was well tolerated. With this we propose the justification for adjuvant trastuzumab in HER2 breast cancer in our population

Glycaemic control improves perfusion recovery and VEGFR2 protein expression in diabetic mice following experimental PAD

Aims Diabetes mellitus (DM) is associated with poor clinical outcomes in humans with peripheral arterial disease (PAD) and in pre-clinical models of PAD, but the effects of glycaemic control are poorly understood. We investigated the effect of glycaemic control on experimental PAD in mice with Type 1 DM and explored the effects of hyperglycaemia on vascular endothelial growth factor receptor 2 (VEGFR2) expression in ischaemia. Methods and results Hind limb ischaemia was induced in non-diabetic, untreated Type 1 DM, and treated Type 1 DM mice. We assessed perfusion recovery, capillary density, VEGFR2 levels, and VEGFR2 ubiquitination in ischaemic hind limbs. We found that untreated Type 1 DM mice showed impaired perfusion recovery, lower hind limb capillary density 5 weeks post-ischaemia, and lower VEGFR2 protein in Day 3 post-ischaemic hind limbs when compared with non-DM controls. Treated Type 1 DM mice had perfusion recovery, capillary density, and VEGFR2 protein levels comparable with that of non-diabetic mice at the same time points. Treatment with anti-VEGFR2 antibody negated that the improved perfusion recovery displayed by treated Type 1 DM mice. In ischaemic Type 1 DM hind limbs and endothelial cells exposed to simulated ischaemia, high glucose impaired VEGFR2 expression and was associated with increased VEGFR2 ubiquitination. Inhibition of the ubiquitin-proteasome complex restored normal endothelial VEGFR2 expression in simulated ischaemia. Conclusion Hyperglycaemia in Type 1 DM impairs VEGFR2 protein expression in ischaemic hind limbs, likely due to increased ubiquitination and degradation by the proteasome complex. Glycaemic control allows normal levels of VEGFR2 in ischaemia and improved perfusion recover

Leishmania aethiopica field isolates bearing an endosymbiontic dsRNA virus induce pro-inflammatory cytokine response.

BACKGROUND: Infection with Leishmania parasites causes mainly cutaneous lesions at the site of the sand fly bite. Inflammatory metastatic forms have been reported with Leishmania species such as L. braziliensis, guyanensis and aethiopica. Little is known about the factors underlying such exacerbated clinical presentations. Leishmania RNA virus (LRV) is mainly found within South American Leishmania braziliensis and guyanensis. In a mouse model of L. guyanensis infection, its presence is responsible for an hyper-inflammatory response driven by the recognition of the viral dsRNA genome by the host Toll-like Receptor 3 leading to an exacerbation of the disease. In one instance, LRV was reported outside of South America, namely in the L. major ASKH strain from Turkmenistan, suggesting that LRV appeared before the divergence of Leishmania subgenera. LRV presence inside Leishmania parasites could be one of the factors implicated in disease severity, providing rationale for LRV screening in L. aethiopica. METHODOLOGY/PRINCIPAL FINDINGS: A new LRV member was identified in four L. aethiopica strains (LRV-Lae). Three LRV-Lae genomes were sequenced and compared to L. guyanensis LRV1 and L. major LRV2. LRV-Lae more closely resembled LRV2. Despite their similar genomic organization, a notable difference was observed in the region where the capsid protein and viral polymerase open reading frames overlap, with a unique -1 situation in LRV-Lae. In vitro infection of murine macrophages showed that LRV-Lae induced a TLR3-dependent inflammatory response as previously observed for LRV1. CONCLUSIONS/SIGNIFICANCE: In this study, we report the presence of an immunogenic dsRNA virus in L. aethiopica human isolates. This is the first observation of LRV in Africa, and together with the unique description of LRV2 in Turkmenistan, it confirmed that LRV was present before the divergence of the L. (Leishmania) and (Viannia) subgenera. The potential implication of LRV-Lae on disease severity due to L. aethiopica infections is discussed

Effects on the maternofetal unit of the rabbit model after substitution of the amniotic fluid with perfluorocarbons

Objectives: Exchanging amniotic fluid (AF) with perfluorocarbon (PFC) may serve as a medium for fetoscopic surgery. This study evaluates the distribution and physiologic effects of intraamniotic PFC as a medium for fetoscopy. Methods: Fetuses of 17 pregnant rabbits underwent either exchange of the AF with PFC, electrolyte solution (ES), or control. The quality of vision during fetoscopy was assessed in AF and PFC. After 6 h, we determined the distribution of PFC in the maternofetal unit. Results: Quality of vision during fetoscopy was better in PFC than with AF. There was no difference in fetal survival between the study groups. PFC was demonstrated on X-ray in the pharynx of 4 fetuses, and the esophagus in 1. Conclusions: PFC provided an ideal medium for fetoscopy without fetal compromise. Copyright (c) 2005 S. Karger AG, Basel

Engineering characterisation of a shaken, single-use photobioreactor for early stage microalgae cultivation using Chlorella sorokiniana.

This work describes the characterisation and culture performance of a novel, orbitally shaken, single-use photobioreactor (SUPBr) system for microalgae cultivation. The SUPBr mounted on an orbitally shaken platform was illuminated from below. Investigation of fluid hydrodynamics indicated a range of different flow regimes and the existence of 'in-phase' and 'out-of-phase' conditions. Quantification of the fluid mixing time (tm) indicated a decrease in tm values with increasing shaking frequency up to 90 rpm and then approximately constant tm values in the range 15-40 s. For batch cultivation of Chlorella sorokiniana, the highest biomass concentration achieved was 6.6 g L(-1) at light intensity of 180 μmol m2 s(-1). Doubling the total working volume resulted in 35-40% reduction in biomass yield while shaking frequency had little influence on culture kinetics and fatty methyl esters composition. Overall this work demonstrates the utility of the SUPBr for early stage development of algal cultivation processes

Food insecurity, diet quality and body composition:data from the Healthy Life Trajectories Initiative (HeLTI) pilot survey in urban Soweto, South Africa

Objective: To determine whether food security, diet diversity and diet quality are associated with anthropometric measurements and body composition among women of reproductive age. The association between food security and anaemia prevalence was also tested. Design: Secondary analysis of cross-sectional data from the Healthy Life Trajectories Initiative (HeLTI) study. Food security and dietary data were collected by an interviewer-administered questionnaire. Hb levels were measured using a HemoCue, and anaemia was classified as an altitude-adjusted haemoglobin level &lt; 12·5 g/dl. Body size and composition were assessed using anthropometry and dual-energy x-ray absorptiometry. Setting: The urban township of Soweto, Johannesburg, South Africa. Participants: Non-pregnant women aged 18-25 years (n 1534). Results: Almost half of the women were overweight or obese (44 %), and 9 % were underweight. Almost a third of women were anaemic (30 %). The prevalence rates of anaemia and food insecurity were similar across BMI categories. Food insecure women had the least diverse diets, and food security was negatively associated with diet quality (food security category v. diet quality score: B = -0·35, 95 % CI -0·70, -0·01, P = 0·049). Significant univariate associations were observed between food security and total lean mass. However, there were no associations between food security and body size or composition variables in multivariate models. Conclusions: Our data indicate that food security is an important determinant of diet quality in this urban-poor, highly transitioned setting. Interventions to improve maternal and child nutrition should recognise both food security and the food environment as critical elements within their developmental phases.</p