Biological fuel cells and their applications

One type of genuine fuel cell that does hold promise in the long-term is the biological fuel cell. Unlike conventional fuel cells, which employ hydrogen, ethanol and methanol as fuel, biological fuel cells use organic products produced by metabolic processes or use organic electron donors utilized in the growth processes as fuels for current generation. A distinctive feature of biological fuel cells is that the electrode reactions are controlled by biocatalysts, i.e. the biological redox-reactions are enzymatically driven, while in chemical fuel cells catalysts such as platinum determine the electrode kinetics. This article provides a brief introduction to biological fuel cells.along with their envisaged applications

Hydrolysis optimization and characterization study of preparing fatty acids from Jatropha curcas seed oil

<p>Abstract</p> <p>Background</p> <p>Fatty acids (FAs) are important as raw materials for the biotechnology industry. Existing methods of FAs production are based on chemical methods. In this study potassium hydroxide (KOH)-catalyzed reactions were utilized to hydrolysis <it>Jatropha curcas </it>seed oil.</p> <p>Results</p> <p>The parameters effect of ethanolic KOH concentration, reaction temperature, and reaction time to free fatty acid (FFA%) were investigated using D-Optimal Design. Characterization of the product has been studied using Fourier transforms infrared spectroscopy (FTIR), gas chromatography (GC) and high performance liquid chromatography (HPLC). The optimum conditions for maximum FFA% were achieved at 1.75M of ethanolic KOH concentration, 65°C of reaction temperature and 2.0 h of reaction time.</p> <p>Conclusions</p> <p>This study showed that ethanolic KOH concentration was significant variable for <it>J. curcas </it>seed oil hydrolysis. In a 18-point experimental design, FFA% of hydrolyzed <it>J. curcas </it>seed oil can be raised from 1.89% to 102.2%, which proved by FTIR and HPLC.</p

Implementing and Evaluating Community Health Worker-Led Cardiovascular Disease Risk Screening Intervention in Sub-Saharan Africa Communities: A Participatory Implementation Research Protocol.

The increasing burden of non-communicable diseases (NCDs), particularly cardiovascular diseases (CVD) in low- and middle-income countries (LMICs) poses a considerable threat to public health. Community-driven CVD risk screening, referral and follow-up of those at high CVDs risk is essential to supporting early identification, treatment and secondary prevention of cardiovascular events such as stroke and myocardial infarction. This protocol describes a multi-country study that aims to implement and evaluate a community health worker (CHW)-led CVD risk screening programme to enhance referral linkages within the local primary care systems in sub-Saharan Africa (SSA), using a participatory implementation science approach. The study builds upon a prior community-driven multicentre study conducted by the Collaboration for Evidence-based Health Care and Public Health in Africa (CEBHA+). This is a participatory implementation research. The study will leverage on the CVD risk citizen science pilot studies conducted in the four selected CEBHA+ project countries (viz. Ethiopia, Rwanda, Malawi, and South Africa). Through planned engagements with communities and health system stakeholders, CHWs and lay health worker volunteers will be recruited and trained to screen and identify persons that are at high risk of CVD, provide referral services, and follow-up at designated community health clinics. In each country, we will use a multi-stage random sampling to select and then screen 1000 study participants aged 35-70 years from two communities (one rural and one urban). Screening will be done using a simple validated non-laboratory-based CVD risk assessment mobile application. The RE-AIM model will be used in evaluating the project implementation outcomes, including reach, fidelity, adoption and perceived effectiveness. Developing the capacities of CHWs and lay health worker volunteers in SSA to support population-based, non-invasive population-based CVD risk prevention has the potential to impact on early identification, treatment and secondary prevention of CVDs in often under-resourced communities. Using a participatory research approach to implementing mobile phone-based CHW-led CVD risk screening, referral and follow-up in SSA will provide the evidence needed to determine the effectiveness of CVD risk screening and the potential for scaling up in the wider region

Phytoremediation of heavy metal-contaminated sites: Eco-environmental concerns, field studies, sustainability issues and future prospects

Environmental contamination due to heavy metals (HMs) is of serious ecotoxicological concern worldwide because of their increasing use at industries. Due to non-biodegradable and persistent nature, HMs cause serious soil/water pollution and severe health hazards in living beings upon exposure. HMs can be genotoxic, carcinogenic, mutagenic, and teratogenic in nature even at low concentration. They may also act as endocrine disruptors and induce developmental as well as neurological disorders and thus, their removal from our natural environment is crucial for the rehabilitation of contaminated sites. To cope with HM pollution, phytoremediation has emerged as a low-cost and eco-sustainable solution to conventional physico-chemical cleanup methods that require high capital investment and labor alter soil properties and disturb soil microflora. Phytoremediation is a green technology wherein plants and associated microbes are used to remediate HM-contaminated sites to safeguard the environment and protect public health. Hence, in view of the above, the present paper aims to examine the feasibility of phytoremediation as a sustainable remediation technology for the management of metals-contaminated sites. Therefore, this paper provides an in-depth review on both the conventional and novel phytoremediation approaches, evaluate their efficacy to remove toxic metals from our natural environment, explore current scientific progresses, field experiences and sustainability issues and revise world over trends in phytoremediation research for its wider recognition and public acceptance as a sustainable remediation technology for the management of contaminated sites in 21st century

Determination of inorganic phosphate by electroanalytical methods: A review

Determination of inorganic phosphate is of very high importance in environmental and health care applications. Hence knowledge of suitable analytical techniques available for phosphate sensing for different applications becomes essential. Electrochemical methods for determining inorganic phosphate have several advantages over other common techniques, including detection selectivity, stability and relative environmental insensitivity of electroactive labels. The different electrochemical sensing strategies adopted for the determination of phosphate using selective ionophores are discussed in this review. The various sensing strategies are classified based on the electrochemical detection techniques used viz., potentiometry, voltammetry, amperometry, unconventional electrochemical methods etc., The enzymatic sensing of phosphate coupled with electrochemical detection is also included. Various electroanalytical methods available in the literature are assessed for their merits in terms of selectivity, simplicity, miniaturisation, adaptability and suitability for field measurements

Glassy carbon electrode modified with hybrid films containing inorganic molybdate anions trapped in organic matrices of chitosan and ionic liquid for the amperometric sensing of phosphate at neutral pH

This work reports an amperometric method for phosphate analysis based on the use of a surface modified glassy carbon electrode (GC). In one configuration of the electrode the surface is modified with ammonium heptamolybdate incorporated in chitosan matrix. A second configuration of the surface modified electrode is formed by introducing, on top of the chitosan film, an additional layer of molybdate dissolved in ionic liquid, 1-Ethyl-3-methylimidazolium tetrafluroborate. The molybdate layers are then coated with a film of PSS + PEDOT (Poly stryrenesulphonate + Poly (3,4-ethylene dioxythiophene)). The chitosan matrix provides the acidic conditions required for the surface molybdate to react with phosphate forming electoactive phosphomolybdate which allows amperometric determination of phosphate. The reduction of ammonium phopshomolybdate is monitored at -0.140 V vs. NCE (Hg/Hg2Cl 2/1 N KCl) at pH 7.2 in Tris buffer. The linear range of detection for phosphate lies between 19 and 100 μM with the first configuration electrode. The limit of determination could be extended to a lower range of 0.79-32 μM using the second configuration electrode. This method is found to be free from interference from anions like arsenate, nitrate and chloride. The method is validated by determining phosphate concentration in a commercial fertilizer sample. This method is highly selective, sensitive, enzyme less and requires no other additional reagents. Additionally it works at neutral pH, hence would be applicable for phosphate analysis in biological samples. Unlike ICP-OES analysis which requires highly sophisticated and costly instrumentation, the proposed method involves simple and cheaper instrumentation requirements and is suitable for field measurements

Biocompatibility of synthesised nano-porous anodic Aluminium oxide membranes for use as a cell culture substrate for Madin-Darby Canine Kidneys cells: A preliminary study

In this study we investigate for the first time the biomedical potential of using a membrane made from anodic aluminium oxide (AAO) for culturing the Madin-Darby Canine Kidney (MDCK) epithelial cell line. Nano-porous aluminium oxide membranes exhibit interesting properties such as high porosity, which allows the exchange of molecules and nutrients across the membrane and can be made with highly specific pore sizes that can be preselected by adjusting the controlling parameters of a temperature controlled two-step anodization process. The cellular response and interactions of the MDCK cell line with the synthesised nano-porous AAO membrane, a commercially available membrane and a glass control were assessed by investigating cell adhesion, morphology and proliferation