A Novel, Ultra-Fast Electrochemical Tool To Study Speciation Of Trace Metals In Aqueous Solution

Trace metals play important roles in biological and ecological systems. In biology, trace metals act as catalytic or structural cofactors and regulate biochemical processes. In the environment, natural and anthropogenic sources of trace metals mobilized into natural waters where they can create harmful and persistent pollution. Trace metal chemistry in physiological and environmental systems can fluctuate rapidly which makes it difficult to clearly define trace metals’ roles in these systems with traditional analytical methods. Furthermore, these systems are often chemically harsh and physically delicate (e.g. the brain), factors that add to the challenge of analysis in real systems. Fast scan cyclic voltammetry is explored in the context of rapid, minimally invasive and robust analysis of Cu2+ and Pb2+ in aqueous samples with carbon fiber microelectrodes. Unique Cu2+-specific and Pb2+-specific waveforms were generated with optimized potential windows and scan rates to provide sub-second analysis of these two trace metals. An array of electrochemical and spectroscopic techniques was employed to discover the underlying mechanisms of the ultra fast FSCV response. Adsorption was explained as the fundamental mechanism for the rapid FSCV signal and the thermodynamic properties of adsorption of Cu2+ onto CFMs were evaluated with fast scan controlled adsorption voltammetry in different matrices. In aquatic systems and soils, metals commonly exist in complexed forms with organic and inorganic ligands. It is generally the free, unbound metal that is the most toxic, thus metal speciation is a critical factor when considering metal pollution. Free Cu2+ concentrations and the solution formation constant, Kfs, provide valuable speciation information. We show that FSCV and FSCAV can be utilized to study copper speciation. Mathematical relationships were constructed from experimental data to predict free Cu2+ concentrations and the overall Kfs of a solution with a range of model ligands, representing a range of Cu2+- ligand Kfs expected to be encountered naturally. These findings showcase the power of FSCV as a real-time biocompatible, eco-friendly speciation sensor with excellent sensitivity and a temporal resolution of milliseconds

Adverse Perinatal Outcomes in COVID-19 Infected Pregnant Women: A Systematic Review and Meta-Analysis.

The impact of COVID-19 virus infection during pregnancy is still unclear. This systematic review and meta-analysis aimed to quantitatively pool the evidence on impact of COVID-19 infection on perinatal outcomes. Databases of Medline, Embase, and Cochrane library were searched using the keywords related to COVID-19 and perinatal outcomes from December 2019 to 30 June 2021. Observational studies comparing the perinatal outcomes of COVID-19 infection in pregnancy with a non-infected comparator were included. The screening process and quality assessment of the included studies were performed independently by two reviewers. Meta-analyses were used to pool the comparative dichotomous data on perinatal outcomes. The database search yielded 4049 results, 1254 of which were duplicates. We included a total of 21 observational studies that assessed the adverse perinatal outcomes with COVID-19 infection. The odds of maternal death (pooled OR: 7.05 [2.41-20.65]), preeclampsia (pooled OR: 1.39 [1.29-1.50]), cesarean delivery (pooled OR: 1.67 [1.29-2.15]), fetal distress (pooled OR: 1.66 [1.35-2.05]), preterm birth (pooled OR: 1.86 [1.34-2.58]), low birth weight (pooled OR: 1.69 [1.35-2.11]), stillbirth (pooled OR: 1.46 [1.16-1.85]), 5th minute Apgar score of less than 7 (pooled OR: 1.44 [1.11-1.86]) and admissions to neonatal intensive care unit (pooled OR: 2.12 [1.36-3.32]) were higher among COVID-19 infected pregnant women compared to non-infected pregnant women

A comparison of policies and guidelines related to multimorbidity in the UK, Australia and Sri Lanka

Background and objectives Increased rates of multimorbidity, evident in developed and developing countries, should be addressed by health policy. The aim of this study was to compare policies and guidelines related to multimorbidity in primary healthcare in countries with different health systems, to identify initiatives, gaps and opportunities for further improvement. Methods We conducted a content analysis of UK, Australian and Sri Lankan policy documents and guidelines published between 2006 and 2017, in electronic databases, references and government repositories, tabulating data extracted for content, implementation plans, gaps and opportunities for development. Results Overall, 38 of the 56 identified documents explicitly or implicitly addressed multimorbidity or its prevention. The UK had four policy documents and guidelines specifically on multimorbidity. Australia and Sri Lanka lacked specific policies on multimorbidity, but policies did address chronic conditions and noncommunicable diseases. Discussion Important differences exist in how national policies seek to address multimorbidity. Policy implementation, how this affects quality of care and outcomes, and the role of primary care should be examined

REST-based Offline e-Mail System

Over the years the Internet has grown from a research tool to a worldwide communication medium. One of the applications that has grown up with the Internet is e-mail. e-Mail has become an indispensable tool for both corporations and individuals, and web-based e-mail systems have become very popular. However, a major problem with web-based email is we cannot access them when not connected to the Internet. We have built an off-line web-based e-mail system to overcome this issue, and to provide fast response even over slow connections. This system is based on Representational State Transfer (REST) and maintains HTML5 local storage to store mail and meta-data in the browser without installing any plug-ins. The system records all user actions locally and synchronizes with the server when connected to the Internet

Probing High Permeability of Nuclear Pore Complexes by Scanning Electrochemical Microscopy: Ca2+ Effects on Transport Barriers

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Analytical Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http:doi.org/10.1021/acs.analchem.9b00796.The nuclear pore complex (NPC) solely mediates molecular transport between the nucleus and cytoplasm of a eukaryotic cell to play important biological and biomedical roles. However, it is not well-understood chemically how this biological nanopore selectively and efficiently transports various substances, including small molecules, proteins, and RNAs by using transport barriers that are rich in highly disordered repeats of hydrophobic phenylalanine and glycine intermingled with charged amino acids. Herein, we employ scanning electrochemical microscopy to image and measure the high permeability of NPCs to small redox molecules. The effective medium theory demonstrates that the measured permeability is controlled by diffusional translocation of probe molecules through water-filled nanopores without steric or electrostatic hindrance from hydrophobic or charged regions of transport barriers, respectively. However, the permeability of NPCs is reduced by a low millimolar concentration of Ca2+, which can interact with anionic regions of transport barriers to alter their spatial distributions within the nanopore. We employ atomic force microscopy to confirm that transport barriers of NPCs are dominantly recessed (∼80%) or entangled (∼20%) at the high Ca2+ level in contrast to authentic populations of entangled (∼50%), recessed (∼25%), and “plugged” (∼25%) conformations at a physiological Ca2+ level of submicromolar. We propose a model for synchronized Ca2+ effects on the conformation and permeability of NPCs, where transport barriers are viscosified to lower permeability. Significantly, this result supports a hypothesis that the functional structure of transport barriers is maintained not only by their hydrophobic regions, but also by charged regions

Development of darrieus-type vertical axis wind turbine for Stand-alone applications

A theoretical model for the design and performance simulation of Darrieus-type vertical axis stand alone wind turbine for small scale energy applications was developed. The model is based on application of momentum theory and blade element theory to multiple stream-tubes. Software was developed to solve the resulting nonlinear equations for the flow-field. Results were used to analyze the effects of blade profile, rotor solidity, Reynolds number and aspect ratio on the maximum power and torque coefficients, optimum tip speed ratio, and ability to self start, which lead to design of optimum rotor configurations

Heuristic approach of berth allocation and quay crane scheduling for Sri Lanka Ports Authority

Maximum utilization of resources is the key aspect for reducing the turnaround time of vessel calls for any container terminal. Among the various resources, effective utilization of berth and quay cranes are directly subscribed causes for the two important optimization problems arisen, which are the berth allocation and quay crane scheduling problems. The berth allocation problem deals with the generation of a berth plan, which determines a suitable berth and when a vessel has to berth alongside the quay. The quay crane scheduling problem illustrates the problem of allocating how many and which quay cranes will serve for each vessel. Given resolving the problems identified in quayside port operations, this project discusses the need for integrated optimization of Berth Allocation Problem (BAP) and Quay Crane Scheduling (QCS) under any circumstances. Online optimization of quayside resources is also a significant need in terms of unpredicted conditions. Therefore, in order to provide provision in discussing the research models associated with solving resource allocation for incoming vessels in port operations, this report surveys the current state of the art in relevant technologies and methods applicable in the industry. Hence, in this research survey, it is mainly focused on resource allocation problems which related to BAP, QCS and forecasting the vessel arrival patterns in Jaye Container Terminal (JCT) of Sri Lanka Ports Authority (SLPA). Finally, in this project, an integrated heuristics based solution methodology is proposed that tackles both BAP and QCS problem. Also, the predictive analyzing model will be developed for forecasting the vessel arrival patterns to analyze the vessel calls using data mining techniques to improve the utilization and to achieve maximum productivity of SLPA simultaneously

Exclusive Breast Feeding Practice in Gangawatakoralaya MOH area, Sri Lanka

Abstract- Breastfeeding is an unequalled way of providing optimal and complete nutrition for the healthy growth and development of infants. Even though the Sri Lankan mothers increasingly choosing to breastfeed their babies’, the rates of exclusive breast feeding for first six months still remain low. The purpose of this study was to determine the prevalence of exclusive breastfeeding practice in Gangawatakoralaya MOH area in Sri Lanka. The study variables were the mother’s occupation, level of education, parity and the sex of the baby. The statistical significance of the study variables were tested by chi-square test using SAS 9.1 and significant effects were tested using Fisher's Exact Test. An effect was considered statistically significant if p< 0.05. Out of the 350 subjects, 215 (61.43 %) mothers exclusively breast fed their children for first six months. Beside breast feeding 77 (22.0%) mothers were given water to their children during the first six months. Statistically significant number of housemaid mothers was exclusively breast fed their children compared to working mothers. Health care workers have a greater responsibility in promoting exclusive breast feeding practice thorough effective health education strategies in Sr