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

Prevention of low birth weight by early risk detection : Relationship between maternal parameters and neonatal birth weight

新潟大学博士（保健学）Low birth weight (LBW) is defined as weighing less than 2500 g at birth, irrespective of gestational age. It is an important risk factor for neonatal morbidity and mortality, as well as a risk for health, growth, and developmental problems in later life. The global rates of LBW are estimated to be 15% to 20% of all births, representing more than 20 million annual births. Although, the majority of LBW deliveries occur in developing countries, the incidence of LBW is a global issue. Sri Lanka is a developing country which was recently upgraded to a lower-to-middle-income country. The rate of LBW in Sri Lanka has fluctuated around 17% for many years, with the most recent national statistics indicating 16% of all live births are LBW. The negative health consequences of a high incidence of LBW deliveries are also an extra burden on the country‘s health care resources, facilities and future plans. This study aimed to find an effective method for early risk detection of LBW in order to implement preventive strategies. A prospective longitudinal study was launched in a tertiary care hospital in Sri Lanka from October 2015 to June 2016. In total, 150 pregnant women who were between 18 and 24 weeks of gestation were included and followed up until delivery. In the overall procedure of data collection, there were 9 exclusions (spontaneous abortions n = 2, multiple fetuses identified at the 20-week ultrasound scan n = 2, maternal desire to deliver at another hospital n = 3 and withdrawal for personal reasons n = 2) between recruitment and baby delivery, resulting in 141 women in the maternal data set. Maternal weight at the time of delivery was collected for 119 women. Researchers failed to collect neonatal data for 14 women and one mother–baby pair was excluded due to low apgar score at 5th minute of birth, resulting in 126 neonatal data set. The study consisted of three parts with the objectives of assessing the effects of maternal nutrition, passive smoking or exposure to wood fuel smoke and pregnancy physical activity on neonatal birth weight. Maternal nutrition was assessed by two parameters as maternal dietary intake and maternal anemia. Socio-demographic data were collected using an interviewer-administered questionnaire. Measurements of maternal height and body weight were taken using standard scales. Maternal dietary intake was assessed using a validated food frequency questionnaire around 22 and 34 weeks of gestation. A structured interviewer-administered questionnaire was used to assess passive smoking and exposure to wood fuel smoke at 30 weeks of gestation. At the same time, exposure was assessed using a breath carbon monoxide monitor. Pregnancy physical activity was assessed using a validated pregnancy physical activity questionnaire which was administered at the same time of dietary assessment, around 22 and 34 weeks gestation.Second trimester (around 22 weeks gestation) maternal dietary data was used to assess the association between maternal dietary intake and neonatal birth weight (n = 141). All women who fulfilled the criteria of having undergone anemia screening at both first antenatal clinic visit and at 28–30 weeks gestation and of having delivered a term singleton neonate were selected for assessment of the association between maternal anemia and birth weight (n = 52). Data on maternal exposure to tobacco smoke and wood fuel smoke was available only for 87 women. By excluding women with missing birth weight data this particular analysis was limited to 76 maternal–neonatal units. Data on pregnancy physical activity was available for 139 women around 22 weeks gestation and for 62 women around 34 weeks gestation. There was a moderate positive correlation between total gestational weight gain and birth weight (p = 0.02), holding pre-pregnancy body mass index and gestational age fixed. The total gestational weight gain of women with low carbohydrate intake during the second trimester (229–429 g/day) was 2.2 kg lower than that of women with moderate carbohydrate intake (430–629 g/day) (95% CI 0.428–4.083 kg; p = 0.016). Similarly, babies of women with low carbohydrate intake during the second trimester were 312 g lighter than those with a moderate carbohydrate intake (95% CI 91–534 g; p = 0.006). Analysis of hemoglobin data showed that the babies whose mothers were anemic during the third trimester had lower mean birth weight than those born to women who were not anemic during the third trimester (p = 0.017). No differences in dietary intake were found between third trimester anemic and non-anemic women (p > 0.05). Women who were exposed to tobacco smoke every day delivered neonates with significantly lower mean birth weight (2,703 ± 539 g) than did women who were only exposed once a week (3,125 ± 464 g) (p < 0.05). A 1-minute increase in cooking time in a kitchen without a chimney increased women‘s expired air carbon monoxide concentration by 0.038 ppm (p = 0.006). Significant reduction in time spent in physical activity and total energy expenditure were observed as pregnancy progressed. No significant association was found between pregnancy physical activity and birth weight. A number of important conclusions can be drawn from the results of this study. First, it can be concluded that maintaining a moderate level of carbohydrate intake during the second trimester may promote favorable total gestational weight gain and neonatal birth weight in Sri Lankan context. Second, maternal anemia in the third trimester is associated with a low mean birth weight. However, the high prevalence of maternal anemia in the third trimester among Sri Lankan women cannot be explained solely by macro and micronutrient deficiencies. Moreover, maternal exposure to tobacco smoke during pregnancy is followed by low mean birth weight of their babies. Finally, there is no significant impact of moderate physical activity on neonatal birth weight. Careful management of these modifiable factors in Sri Lanka is essential components of strategies seeking to prevent LBW.学位の種類: 博士（保健学）. 報告番号: 甲第4487号. 学位記番号: 新大院博（保）甲第25号. 学位授与年月日: 平成30年3月23日新大院博（保）甲第25号thesi

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

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

Video Guides on Head-Mounted Displays: The Effect of Misalignments on Manual Task Performance

奈良先端科学技術大学院大学修士(工学)master thesi

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