The Ebola crisis and people with disabilities' access to healthcare and government services in Liberia

BACKGROUND: There has been little research on the impact of the 2014-2015 West African Ebola crisis on people with disabilities. This paper outlines the way in which the Ebola Virus Disease (EVD) outbreak in Liberia in 2015 highlighted existing inequalities and exclusion of people with disabilities and their households. METHODS: The results presented here are part of a larger ESRC/DFID-funded mixed methods research project in Liberia (2014-2017) which included a quantitative household survey undertaken in five counties, complemented by qualitative focus group discussions and interviews with people with disabilities and other key stakeholders. Uniquely, this research gathered information about people with disabilities' experience of the EVD outbreak, as well as additional socioeconomic and inclusion data, that compared their experience with non-disabled community members. RESULTS: Reflections by people with disabilities themselves show knowledge, preparation, and responses to the EVD epidemic was often markedly different among people with disabilities due to limited resources, lack of inclusion by many mainstream public health and medical interventions and pre-existing discrimination, marginalisation and exclusion. Interviews with other key stakeholder revealed a lack of awareness of disability issues or sufficient training to include this population systematically in both Ebola response activities and general health services. Key findings include the need to understand and mitigate direct and indirect health consequences of unequal responses to the epidemic, as well as the limited capacity of healthcare and social services to respond to people with disabilities. CONCLUSION: There are lessons to be learned from Ebola outbreak around inclusion of people with disabilities, relevant to the current COVID-19 pandemic. Now is the time to undertake measures to ensure that people with disabilities do not continue to be marginalised and excluded during global public health emergencies

Elemental Diffusion Behaviour of Biomedical Grade Titanium Alloy through Thermal Oxidation

Major issues related to implant failure are wear debris and metal ions release where Titanium-Aluminium-Niobium alloys still face those problems despite of better biocompatibility. Surface modification is one of the alternatives in order to reduce those wear as well as ion release problems to the host tissue. In this study, experiments were carried out to investigate the element diffusion behaviour of Ti-6Al-7Nb alloy through thermal oxidation in order to obtain coating on the surfaces for diminishing those effects. Thermal oxidation was carried out at 650°C for three different durations 6, 12 and 24 hours. It is found that at prolong time, Niobium diffusion occurs where short duration Aluminium dominates. This suggests that longer heating time promotes heavy metal diffusion by restricting diffusion of light metal and hence, dominates the heavy metal oxide layer formation. The oxide layer formed on the substrate may lead to increase the lifespan of the implant and reduces the harmful effects caused by wear debris or toxic ion from metal alloys

Tranilast increases vasodilator response to acetylcholine in rat mesenteric resistance arteries through increased EDHF participation

Background and Purpose: Tranilast, in addition to its capacity to inhibit mast cell degranulation, has other biological effects, including inhibition of reactive oxygen species, cytokines, leukotrienes and prostaglandin release. In the current study, we analyzed whether tranilast could alter endothelial function in rat mesenteric resistance arteries (MRA). Experimental Approach: Acetylcholine-induced relaxation was analyzed in MRA (untreated and 1-hour tranilast treatment) from 6 month-old Wistar rats. To assess the possible participation of endothelial nitric oxide or prostanoids, acetylcholineinduced relaxation was analyzed in the presence of L-NAME or indomethacin. The participation of endothelium-derived hyperpolarizing factor (EDHF) in acetylcholine-induced response was analyzed by preincubation with TRAM-34 plus apamin or by precontraction with a high K+ solution. Nitric oxide (NO) and superoxide anion levels were measured, as well as vasomotor responses to NO donor DEA-NO and to large conductance calcium-activated potassium channel opener NS1619. Key Results: Acetylcholine-induced relaxation was greater in tranilast-incubated MRA. Acetylcholine-induced vasodilation was decreased by L-NAME in a similar manner in both experimental groups. Indomethacin did not modify vasodilation. Preincubation with a high K+ solution or TRAM-34 plus apamin reduced the vasodilation to ACh more markedly in tranilastincubated segments. NO and superoxide anion production, and vasodilator responses to DEA-NO or NS1619 remained unmodified in the presence of tranilast. Conclusions and Implications: Tranilast increased the endothelium-dependent relaxation to acetylcholine in rat MRA. This effect is independent of the nitric oxide and cyclooxygenase pathways but involves EDHF, and is mediated by an increased role of small conductance calcium-activated K+ channelsThis study was supported by Ministerio de Ciencia e Innovación (SAF 2009-10374), Ministerio de Economía y Competitividad (SAF 2012-38530), and Fundación Mapfre. F.E. Xavier is recipient of research fellowship from Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brazil

Breast Cancer Stem-Like Cells Are Inhibited by a Non-Toxic Aryl Hydrocarbon Receptor Agonist

Cancer stem cells (CSCs) have increased resistance to cancer chemotherapy. They can be enriched as drug-surviving CSCs (D-CSCs) by growth with chemotherapeutic drugs, and/or by sorting of cells expressing CSC markers such as aldehyde dehydrogenase-1 (ALDH). CSCs form colonies in agar, mammospheres in low-adherence cultures, and tumors following xenotransplantation in Scid mice. We hypothesized that tranilast, a non-toxic orally active drug with anti-cancer activities, would inhibit breast CSCs.We examined breast cancer cell lines or D-CSCs generated by growth of these cells with mitoxantrone. Tranilast inhibited colony formation, mammosphere formation and stem cell marker expression. Mitoxantrone-selected cells were enriched for CSCs expressing stem cell markers ALDH, c-kit, Oct-4, and ABCG2, and efficient at forming mammospheres. Tranilast markedly inhibited mammosphere formation by D-CSCs and dissociated formed mammospheres, at pharmacologically relevant concentrations. It was effective against D-CSCs of both HER-2+ and triple-negative cell lines. Tranilast was also effective in vivo, since it prevented lung metastasis in mice injected i.v. with triple-negative (MDA-MB-231) mitoxantrone-selected cells. The molecular targets of tranilast in cancer have been unknown, but here we demonstrate it is an aryl hydrocarbon receptor (AHR) agonist and this plays a key role. AHR is a transcription factor activated by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), polycyclic aromatic hydrocarbons and other ligands. Tranilast induced translocation of the AHR to the nucleus and stimulated CYP1A1 expression (a marker of AHR activation). It inhibited binding of the AHR to CDK4, which has been linked to cell-cycle arrest. D-CSCs expressed higher levels of the AHR than other cells. Knockdown of the AHR with siRNA, or blockade with an AHR antagonist, entirely abrogated the anti-proliferative and anti-mammosphere activity of tranilast. Thus, the anti-cancer effects of tranilast are AHR dependent.We show that tranilast is an AHR agonist with inhibitory effects on breast CSCs. It is effective against CSCs of triple-negative breast cancer cells selected for anti-cancer drug resistance. These results suggest it might find applications in the treatment of breast cancer

An experimental investigation on partial-ductile mode grinding of silicon

This research work was primarily concentrated on precise ductile-mode grinding (milling) of flat surfaces of silicon, mainly Integrated Circuit (IC) silicon chips (dies), which were about 700 µm thick and the top of their surfaces covered with a silicon nitride layer. Substantial amount of partial-ductile streaks on a machined silicon surface shortens polishing time dramatically. This is of vital importance particularly in chip-making and optical industries for failure analysis. Failure analysis is a technique usually practised for locating a fault in a finished IC product. In chip-making industries, the analysis is done on the damage-free mirror-like finished silicon die of the IC. Grinding, lapping and/or polishing operations are required to get such a smooth surface. Precision grinding in a ductile mode therefore remains the critical and most important machining operation as the surface and sub-surface damages will be minimized. This results in good quality surface in terms of surface finish and flatness and at the same time generating the maximum amount of ductile streaks on the machined surface. Silicon material other than the IC silicon was also tried out for purpose of comparison and because of limited number of IC chips. Silicon like any hard and brittle material is well known for its low machinability unless it is machined under ductile mode condition. Ductile mode machining is a process that makes brittle materials to behave like ductile materials. A low cost machining technique, which facilitates partial-ductile mode grinding of small areas on thin wafer-like silicon, was developed. A specially modified conventional MAHO CNC Vertical Milling Centre that has an air driven low powered high-speed attachment (precision jig grinder) facilitated the diamond grinding. Special fixtures were designed and fabricated that held the workpieces in position and prevented them from damage during machining. Both traditional and statistical techniques for designing of experiments and subsequent analysis of results were employed in this study. A low cutting force dynamometer (Compacdyn) was used to measure cutting forces. Form Talysurf and Surfcom Surface Analysers and Atomic Force Microscope were used to measure surface texture parameters. Optical, Scanning Electron microscopy techniques, together with the Surfcom Surface Analyser and Atomic Force Microscope, were used to examine the surface morphology of the machined silicon surfaces. It was found that the amount of ductile streaks generated on a work-piece surface was not only dependent on feed and depth of cut but also on the grit size of diamond abrasive. The machining technique of grinding yielded ground surfaces with Ra as low as 50 nm, and forces around 0.8 Newton. Flatness of the machined surfaces is very good. A model of surface roughness (Ra) for precision grinding of thin silicon has been established

Experimental investigation of the effect of cutting tool coating on delamination during of milling Metal Matrix Composite (MMC)

Metal Matrix Composite (MMC) has become one of the materials that is known to have high hardness and abrasive nature, due to the presence of silicon carbide (SiC) inside the composite. The characteristic nature of the MMC results in unpredictable cutting tool performance when it comes to a machining process. In order to explore a better means of improving the cutting of this material, coated tools were used to mill a MMC laminate composite. Therefore, experiments were carried out to cut a MMC laminate plate of 50 mm x 50 mm x 2 mm using 4 mm-diameter carbide end mills coated titanium aluminum nitride (TiAlN), as it is believed that TiAlN is one of the coatings, that has unique properties such as lower friction, higher adhesion, higher resistance to wear and crack. Box Behnken design was used to plan the running of experiments. Three independent cutting parameters, spindle speed, feed rate and depth of cut with values ranging from 4500-7500 rpm, 100-250 mm/min and 0.25-0.75 mm respectively, were studied. Experimental results show that delamination of the machined MMC was influenced mostly by feed rate and the depth of cut

Effect of carburization process on adhesion strength of Ti carbide layer on titanium alloy substrate

Titanium alloys are commonly used in biomedical application in hard tissues replacement especially for knee and hip implants. Surface modifications are required prior to diamond coating process for improving tribological and wear properties of the titanium alloy. In this study, experiments were carried out to investigate the effects of different carburizing times on the adhesion strength of carbide layer formed on the Ti-6Al-7Nb. Prior to carburization process, all samples were treated to remove residual stress and oxide scales by annealing and pickling processes respectively. Hard wood charcoal powder was used as a medium. The carburizing process was carried out for 6, 12 and 24 hours at 950 °C under normal atmospheric condition. Surface morphology, carbide layer thickness and adhesion strength were evaluated using SEM, XRD, 3D Surface Profilometer and Blast Wear Tester (BWT). It is found that a mixture of oxide and carbide layers formed on the substrate and the thickness of these layers increases with carburizing time. It is also revealed that the 24 hr carburizing time provides the strongest adhesion strength among the three and TiC as the dominant layer

Prediction and experimental validation of temperature rise in ductile mode end milling of soda-lime glass

The suitable thermal, chemical, and corrosion resistance properties of glass make it possible to be used in a wide variety of product manufacturing, like lenses, mirrors, mold, semiconductor, biomedical, optical, and micro-electronics. However, machining of glass like any brittle material has big challenges owing to its inherent brittleness. Ductile mode machining is known to promote the material removal from a brittle material in ductile manner rather than by brittle fracture. In high-speed machining, the thermal softening effects can enhance flexibility in ductile machining of brittle materials. In this paper, an analytical model is developed to predict the amount of temperature generated in the immediate next removable layer (INRL) of the soda-lime glass work piece per unit depth of cut ∆T¯ INRL based on fundamental micro-machining principle and material physical properties. The model incorporates the effects of cutting speed, feed rate, strain rate, and thermal softening effect. The simulation and experimental results showed that at high cutting speed, glass softening can be achieved by adiabatic heating in order to facilitate ductile machining. The amount of adiabatic heating can be controlled by predicting the amount of the ∆T¯ INRL

Surface roughness prediction in high speed flat end milling of Ti-6Al-4V and optimization by desirability function of RSM

High Speed Machining is applicable for producing parts that require little or no grinding / polishing operations within the required machining tolerances. For achieving required level of quality, selection of cutting tools and parameters in high speed machining is very important. In this study, small diameter flat end milling tool was used to achieve high rpm to facilitate the application of low values of feed and depth of cut to achieve better surface roughness. Machining was performed on a Vertical Machining Centre (VMC) with a high speed milling attachment (HES 510), using cutting speed, depth of cut, and feed as machining variables. Statistical prediction model of average surface roughness was developed using three-level full factorial design of experiments. It was observed that depth of cut is the most dominating factor followed by cutting speed and feed. The developed model was used for optimization by desirability function approach to obtain minimum Ra. Maximum desirability of 95.63% was obtained