Review of Analytical Techniques for Arsenic Detection and Determination in Drinking Water

Arsenic occurs in the natural environment in four oxidation states: As(V), As(III), As(0) and As(−III). The behavior of arsenic species changes depending on the biotic or abiotic conditions in water. In groundwater, arsenic is predominantly present as As(III) and As(V), with a minor amount of methyl and dimethyl arsenic compounds being reported. Global intake of As(III) and As(V) via drinking water and food has dramatically increased in recent years. The commonly used term inorganic arsenic includes both As(III) and As(V) species and constitutes the highest toxicological risk associated with arsenic in water compared to the organic arsenic species. Inorganic arsenic is a confirmed carcinogen and the World Health Organization (WHO) has published a guideline value for arsenic in their ‘Guidelines for drinking water quality’ and is on the WHO list of 10 chemicals of major public health concern. Presently, approximately, 230 million people worldwide are affected by arsenic toxicity. Chronic arsenic toxicity affects multiple physiological systems and can cause serious health issues (e.g. arsenicosis, cancer etc.) leading to death. To combat arsenic pollution, the WHO and United States Environmental Protection Agency (US-EPA) have set concentration limits for arsenic in drinking water. The WHO, US-EPA and European Union (EU) have set the maximum limit of arsenic in drinking water at 10 ppb. To meet the required limit, it is essential that rapid, reliable, sensitive and cost-effective analytical detection systems be developed and put into use. Different determination methods of inorganic arsenic have been developed over the last 5–6 decades. This review provides an overview of around 170 research articles and relevant literature, mainly regarding the existing methods for analysis of As(III) and As(V) in water. Chromatographic, spectroscopic, colorimetric, biological (whole cell biosensors (WCB) and aptasensors), electroanalytical and coupled techniques are discussed. For those who are at the early stage of their research career in this field, the basic introduction and necessary concepts for various techniques is discussed followed by an evaluation of their performance towards arsenic determination. Current challenges as well as potential avenues for future research, including the demands for enhanced analytical performance, rapid analysis and on-site technologies for remote water analysis and environmental applications are discussed. We believe that this review will be beneficial, a source of information, and enhance awareness and appreciation of the role of these advanced analytical techniques in informing and protecting our environment and water resources, globally. Environmental signicance Global intake of arsenic via drinking water is a major environmental concern: As(III)/As(V) species constitutes the highest toxicological-risk. To combat arsenic pollution and associated toxicity, WHO and EPA have regulations, guidelines and introduced directives for arsenic concentration limits in drinking water. The existing laboratory-based methods are suitable for arsenic analysis but are time-consuming, expensive and require skilled analysts and extensive sample preparation. Rapid, cost-effective and reliable portable techniques and on-site sensor-based methods are the emerging needs. This review provides an overview of various analytical techniques for arsenic detection and determination in water, and will enhance awareness of their role in informing and protecting our environment and water resources, globally. 1. Introduction Water covers more than 70% of our planet\u27s surface. Because life on Earth began in water, it is not surprising that all living organisms on our blue planet require water. Water is in fact the most valuable environmental natural resource, vital to global need, a transport corridor and a climate regulator. Global intake a MiCRA Biodiagnostics Technology Gateway, Technological University Dublin (TU Dublin), Dublin 24, D24 FKT9, Ireland. E-mail: [email protected]; Tel: +353 1 220 7863 b Centre of Applied Science for Health, Technological University Dublin (TU Dublin), Dublin 24, D24 FKT9, Ireland c School of Food Science & Environmental Health, Technological University Dublin (TU Dublin), Grangegorman, Dublin 7, D07 H6K8, Ireland d Pesticide Registration Division, Department of Agriculture, Food and the Marine, Backweston Laboratory Campus, Celbridge, County Kildare W23 VW2C, Ireland Cite this: Environ. Sci.: Adv., 2023, 2, 171 Received 8th September 2022 Accepted 4th November 2022 DOI: 10.1039/d2va00218c rsc.li/esadvances © 2023 The Author(s). Published by the Royal Society of Chemistry Environ. Sci.: Adv., 2023, 2, 171–195 | 171 Environmental Science Advances TUTORIAL REVIEW Open Access Article. Published on 07 November 2022. Downloaded on 3/1/2023 9:48:16 AM. This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. View Article Online

Prevalence of Severe Anxiety among Elective Caesarean Section Mothers and their Perceived Complications of Anaesthesia in Malaysia

Introduction: Many women experience psychological problems during pregnancy. One of the major psychological problems is anxiety. Pregnancy related anxiety can lead to various negative effects not only on mother’s health, but also on their socio-dynamic factors as well as the infant’s development. Preoperative anxiety among obstetric patients is known to be much higher compared to other surgical patients. Aim: In this study we assessed the prevalence of severe anxiety among elective caesarean section mothers and their perceived complications of anaesthesia in Malaysia. Method: This study was conducted among 280 pregnant women in the obstetrics and gynaecology department in a tertiary hospital in Malaysia. The pregnant women’s level of anxiety was assessed using the 20-item S-anxiety scale, preoperative and postoperative. Results: Pre-operative, out of the 280 respondents, 70 (25%) were classified as having severe anxiety. Among those with previous SVD, 41.7% had severe level of anxiety compared to only 21.2% among those with previous LSCS (p=0.008). At post-operative assessment, 27 (9.6%) were classified as having severe anxiety. Overall, there was a significant reduction in the level of anxiety from pre to post operative (p <0.001). The perceived complications from general anaesthesia were death (34.3%), coma (32.1%) and postoperative pain (30%) and the perceived complications from regional anaesthesia were back pain (27.9%) and paralysis (27.9%). Conclusion: Preoperative anxiety in women undergoing caesarean section is high. Preoperative anxiety should be evaluated for further planning of coping strategies to overcome their anxiety and fear

Visual spatial memory is enhanced in female rats (but inhibited in males) by dietary soy phytoestrogens

BACKGROUND: In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined. RESULTS: Female rats receiving lifelong exposure to a high-phytoestrogen containing diet (Phyto-600) acquired the maze faster than females fed a phytoestrogen-free diet (Phyto-free); in males the opposite diet effect was identified. In a separate experiment, at 80 days-of-age, animals fed the Phyto-600 diet lifelong either remained on the Phyto-600 or were changed to the Phyto-free diet until 120 days-of-age. Following the diet change Phyto-600 females outperformed females switched to the Phyto-free diet, while in males the opposite diet effect was identified. Furthermore, males fed the Phyto-600 diet had significantly higher phytoestrogen concentrations in a number of brain regions (frontal cortex, amygdala & cerebellum); in frontal cortex, expression of CALB (a neuroprotective calcium-binding protein) decreased while COX-2 (an inducible inflammatory factor prevalent in Alzheimer's disease) increased. CONCLUSIONS: Results suggest that dietary phytoestrogens significantly sex-reversed the normal sexually dimorphic expression of VSM. Specifically, in tasks requiring the use of reference, but not working, memory, VSM was enhanced in females fed the Phyto-600 diet, whereas, in males VSM was inhibited by the same diet. These findings suggest that dietary soy derived phytoestrogens can influence learning and memory and alter the expression of proteins involved in neural protection and inflammation in rats

Proteomic Analysis of Rat Hypothalamus Revealed the Role of Ubiquitin–Proteasome System in the Genesis of DR or DIO

Obesity has become a global epidemic, contributing to the increasing burdens of cardiovascular disease and type 2 diabetes. However, the precise molecular mechanisms of obesity remain poorly elucidated. The hypothalamus plays a major part in regulating energy homeostasis by integrating all kinds of nutritional signals. This study investigated the hypothalamus protein profile in diet-induced obese (DIO) and diet-resistant (DR) rats using two dimensional gel electrophoresis (2-DE) combined with MALDI-TOF/TOF–MS analysis. Twenty-two proteins were identified in the hypothalamus of DIO or DR rats. These include metabolic enzymes, antioxidant proteins, proteasome related proteins, and signaling proteins, some of which are related to AMP-activated protein kinase (AMPK) signaling or mitochondrial respiration. Among these proteins, in comparison with the normal-diet group, Ubiquitin was significantly decreased in DR rats but not changed in DIO rats, while Ubiquitin carboxyl-terminal esterase L1 (UCHL-1) was decreased in DIO rats but not changed in DR rats. The expression level of Ubiquitin and UCHL-1 were further validated using Western blot analysis. Our study reveals that Ubiquitin and UCHL-1 are obesity-related factors in the hypothalamus that may play an important role in the genesis of DR or DIO by interfering with the integrated signaling network that control energy balance and feeding

Rectification of electronic heat current by a hybrid thermal diode

We report the realization of an ultra-efficient low-temperature hybrid heat current rectifier, thermal counterpart of the well-known electric diode. Our design is based on a tunnel junction between two different elements: a normal metal and a superconducting island. Electronic heat current asymmetry in the structure arises from large mismatch between the thermal properties of these two. We demonstrate experimentally temperature differences exceeding $60$ mK between the forward and reverse thermal bias configurations. Our device offers a remarkably large heat rectification ratio up to $\sim 140$ and allows its prompt implementation in true solid-state thermal nanocircuits and general-purpose electronic applications requiring energy harvesting or thermal management and isolation at the nanoscale.Comment: 8 pages, 6 color figure

A novel whole-cell lysate kinase assay identifies substrates of the p38 MAPK in differentiating myoblasts

<p>Abstract</p> <p>Background</p> <p>The p38α mitogen-activated protein kinase (MAPK) is a critical mediator of myoblast differentiation, and does so in part through the phosphorylation and regulation of several transcription factors and chromatin remodelling proteins. However, whether p38α is involved in processes other than gene regulation during myogenesis is currently unknown, and why other p38 isoforms cannot compensate for its loss is unclear.</p> <p>Methods</p> <p>To further characterise the involvement of p38α during myoblast differentiation, we developed and applied a simple technique for identifying relevant <it>in vivo </it>kinase substrates and their phosphorylation sites. In addition to identifying substrates for one kinase, the technique can be used <it>in vitro </it>to compare multiple kinases in the same experiment, and we made use of this to study the substrate specificities of the p38α and β isoforms.</p> <p>Results</p> <p>Applying the technique to p38α resulted in the identification of seven <it>in vivo </it>phosphorylation sites on six proteins, four of which are cytoplasmic, in lysate derived from differentiating myoblasts. An <it>in vitro </it>comparison with p38β revealed that substrate specificity does not discriminate these two isoforms, but rather that their distinguishing characteristic appears to be cellular localisation.</p> <p>Conclusion</p> <p>Our results suggest p38α has a novel cytoplasmic role during myogenesis and that its unique cellular localisation may be why p38β and other isoforms cannot compensate for its absence. The substrate-finding approach presented here also provides a necessary tool for studying the hundreds of protein kinases that exist and for uncovering the deeper mechanisms of phosphorylation-dependent cell signalling.</p

Rethinking summarization and storytelling for modern social multimedia

Traditional summarization initiatives have been focused on specific types of documents such as articles, reviews, videos, image feeds, or tweets, a practice which may result in pigeonholing the summarization task in the context of modern, content-rich multimedia collections. Consequently, much of the research to date has revolved around mostly toy problems in narrow domains and working on single-source media types. We argue that summarization and story generation systems need to re-focus the problem space in order to meet the information needs in the age of user-generated content in different formats and languages. Here we create a framework for flexible multimedia storytelling. Narratives, stories, and summaries carry a set of challenges in big data and dynamic multi-source media that give rise to new research in spatial-temporal representation, viewpoint generation, and explanatio

30 inch Roll-Based Production of High-Quality Graphene Films for Flexible Transparent Electrodes

We report that 30-inch scale multiple roll-to-roll transfer and wet chemical doping considerably enhance the electrical properties of the graphene films grown on roll-type Cu substrates by chemical vapor deposition. The resulting graphene films shows a sheet resistance as low as ~30 Ohm/sq at ~90 % transparency which is superior to commercial transparent electrodes such as indium tin oxides (ITO). The monolayer of graphene shows sheet resistances as low as ~125 Ohm/sq with 97.4% optical transmittance and half-integer quantum Hall effect, indicating the high-quality of these graphene films. As a practical application, we also fabricated a touch screen panel device based on the graphene transparent electrodes, showing extraordinary mechanical and electrical performances