Environmental externalities of the COVID-19 lockdown: Insights for sustainability planning in the Anthropocene.

The COVID-19 pandemic has abruptly halted the Anthropocene's ever-expanding reign for the time being. The resulting global human confinement, dubbed as the Anthropause, has created an unprecedented opportunity for us to evaluate the environmental consequences of large-scale changes in anthropogenic activities. Based on a methodical and in-depth review of related literature, this study critically evaluates the positive and negative externalities of COVID-19 induced lockdown on environmental components including air, water, noise, waste, forest, wildlife, and biodiversity. Among adverse impacts of the lockdown, increased amount of healthcare waste (300-400%), increased level of atmospheric ozone (30-300%), elevated levels of illicit felling in forests and wildlife poaching were prominent. Compared to the negative impacts, significant positive changes in various quality parameters related to key environmental components were evident. Positive impacts on air quality, water quality, noise level, waste generation, and wildlife were apparent in varying degrees as evaluated in this study. By presenting a critical overview of the recommendations given in the major literature in light of these documented impacts, this paper alludes to potential policy reforms as a guideline for future sustainable environmental management planning. Some of the key recommendations are e.g., enhance remote working facilities, cleaner design, use of internet of things, automation, systematic lockdown, and inclusion of hazardous waste management in disaster planning. The summarized lessons of this review, pertinent to the dynamic relationship between anthropogenic activities and environmental degradation, amply bring home the need for policy reforms and prioritization of Sustainable Development Goals in the context of the planetary boundaries to the environmental sustainability for a new post-pandemic world.

Regioselectivity in the Scholl Reaction: Mono and Double [7]Helicenes.

We employed the density functionaly theory (DFT)-predicted regioselectivity of the intramolecular Scholl reaction in phenanthrene and dibenzo[g,p]chrysene frameworks to obtain π-extended mono and double [7]helicenes, respectively. The formation of these helical structures occurs despite the buildup of a large strain energy up to 30 kcal/mol compared with their most stable isomers. The twisted and strained structures were characterized and analyzed by experimental (NMR, UV-vis, emission, electrochemistry, and single-crystal X-ray diffraction) techniques and were further supported by DFT calculations.

Urban metabolism of phosphorus in the food production-consumption system of Bangladesh.

Anthropogenic disruption of the global phosphorus (P) cycle has already pushed it beyond the planetary boundary. Understanding P metabolism at global, regional and local scales is critical to close the loop of P for the safekeeping of mankind. Investigating the effects of urbanization-induced income growth on the natural nutrient (especially P) cycles contribute to that end. Bangladesh, a lower-middle-income agrarian economy seeing rapid urbanization and stunning GDP growth, presents itself as a good case for P-metabolism research. Past efforts to quantify P flows in the country have not addressed the effects of urbanization thereon. This time-series study quantifies the P flows in rural and urban Bangladesh using substance flow analysis after outlining the urbanization indicators (viz. GDP, income per capita, percentage of income spent on food, change in urban population and built-up area) which affects urban metabolism of P. Urbanization caused a dietary transition from cereal-based to animal-based diet resulting in 50% more P consumption from the latter by urban individuals than their rural counterparts in 2010. Comparing the P flows among the 19 expenditure groups of the urban population, an individual belonging to a higher expenditure group (USD 71-82) consumed 38% more P than one of the lower groups (USD 17-21) in 2016. Future forecasting was conducted for (i) future demand of P fertilizer using human appropriation of net primary productivity (HANPP) and (ii) P recovery potential from urban household food waste for the policymakers to get a glimpse of the future demand and recovery potential of P. The projections suggested approximately 145% rise in the national P inflow by 2030. Moreover, the universal adoption of source separation of household food waste in the two largest cities of Bangladesh can cycle back almost 1.2 × 103 tonnes of P to the system by 2030. As Bangladesh poises to faster economic growth in decades ahead, the study provides a basis for policy formulation for an appropriate P management plan to achieve circularity in nutrient use.

The Transient Covalent Bond in Abiotic Nonequilibrium Systems.

Biochemical systems accomplish many critical functions with by operating out-of-equilibrium using the energy of chemical fuels. The formation of a transient covalent bond is a simple but very effective tool in designing analogous reaction networks. This Minireview focuses on the fuel chemistries that have been used to generate transient bonds in recent demonstrations of abiotic nonequilibrium systems (i.e., systems that do not make use of biological components). Fuel reactions are divided into two fundamental classifications depending on whether the fuel contributes structural elements to the activated state, a distinction that dictates how they can be used. Reported systems are further categorized by overall fuel reaction (e.g., hydrolysis of alkylating agents, carbodiimide hydration) and illustrate how similar chemistry can be used to effect a wide range of nonequilibrium behavior, ranging from self-assembly to the operation of molecular machines.

Knowledge, attitudes, and practices toward the novel coronavirus among Bangladeshis: Implications for mitigation measures.

The current novel coronavirus (nCoV) pandemic, COVID-19, was first reported in December 2019 in Wuhan, China, and has spread globally, causing startling loss of life, stalling the global economy, and disrupting social life. One of the challenges to contain COVID-19 is convincing people to adopt personal hygiene, social distancing, and self-quarantine practices that are related to knowledge, attitudes, and practices (KAP) of the residents of respective countries. Bangladesh, a densely populated country with a fast-growing economy and moderate literacy rate, has shown many hiccups in its efforts to implement COVID-19 policies. Understanding KAP may help policy makers produce informed decisions. This study assessed KAP in relation to COVID-19 in Bangladesh. An online survey using a pre-tested questionnaire conducted in late March 2020 attained 1,837 responses across Bangladesh. Ultimately, 1,589 completed responses were included in a statistical analysis to calculate KAP scores and their interrelations with sociodemographic variables. The overall KAP was poor, with only 33% of the participants demonstrating good knowledge, whereas 52.4% and 44.8% of the subjects showed good attitudes and practices, respectively. Sociodemographic factors had strong bearings on the KAP scores. Significantly higher KAP scores were evident in females over males, among aged 45 years and older over younger participants, and among retired workers and homemakers over students and public service employees. This study indicated a panic fuelled by poor understanding of COVID-19 associated facts and the need for the government to ensure more granular and targeted awareness campaigns in a transparent and factual manner to foster public confidence and ensure more meaningful public participation in mitigation measures. This study provides a KAP baseline regarding COVID-19 among Bangladeshis.

Dissipative Assembly of Macrocycles Comprising Multiple Transient Bonds.

Dissipative assembly has great potential for the creation of new adaptive chemical systems. However, while molecular assembly at equilibrium is routinely used to prepare complex architectures from polyfunctional monomers, species formed out of equilibrium have, to this point, been structurally very simple. In most examples the fuel simply effects the formation of a single short-lived covalent bond. Herein, we show that chemical fuels can assemble bifunctional components into macrocycles containing multiple transient bonds. Specifically, dicarboxylic acids give aqueous dianhydride macrocycles on treatment with a carbodiimide. The macrocycles are assembled efficiently as a consequence of both fuel-dependent and fuel-independent mechanisms; they undergo slower decomposition, building up as the fuel recycles the components, and are a favored product of the dynamic exchange of the anhydride bonds. These results create new possibilities for generating structurally sophisticated out-of-equilibrium species.

Angular ladder-type meta-phenylenes: synthesis and electronic structural analysis.

Herein, we report the synthesis of two new series of angular (all-syn) ladder-type meta-[n]phenylenes (LMP, n = 3-8). One series contains keto groups at the termini bridges, denoted angular keto (AKn), the second contains alkyl groups at all bridge sp3 carbons, denoted angular alkyl (AAn). Their electronic and structural properties were delineated by a combination of electrochemistry and spectroscopic (UV-Vis and emission) methods and further supported by DFT calculations. Interestingly, experimental and DFT data show that changing the bridging group at the termini from alkyl (AAn) to keto (AKn) gives an increase in the first reduction potentials and LUMO energies, as the π-system is extended. Also, the charge (de)localization behavior is different for these two species; while the AAn compounds stablize charge with Robin-Day class III, the AKn compounds show a clear switch from class III to class II. In comparison with the linear analogues (LKn and LAn), DFT results reveal a shape independency of the charge (de)localization mechanism in acceptor-π-acceptor series (AKn/LKn).

Assessment of health risks associated with potentially toxic element contamination of soil by end-of-life ship dismantling in Bangladesh.

Ship breaking and recycling industry (SBRI) loops back scarce ferrous and non-ferrous materials from dismantled ships and also renews the global shipping fleet by treating the end-of-life (EoL) ships. Currently, SBRIs in Bangladesh, India, and Pakistan are dismantling the majority of the EoL ships by open beaching method. Accordingly, ship dismantling carries the blame of releasing potentially toxic elements (PTEs) to the coastal and marine environment risking the food chain through potential bioaccumulation and biomagnification. Health risk assessment associated with PTEs from open beach ship dismantling is scarce. This study aimed at assessing concentrations and seasonal variations of PTEs in soils exposed to the activities of SBRIs for their source apportionment by using contamination factor (CF) and multivariate statistical analysis, while carcinogenic and non-carcinogenic health risks due to the PTEs have also been determined. Soil samples were collected twice-during pre-monsoon and post-monsoon seasons-from three working zones of each of the 15 different ship breaking yards spanning the entire SBRI zone in Bangladesh. Soil contamination was assessed by using the CF, and inverse distance weighting interpolation mapping showed the spatial distribution of metals at SBRI zone in Bangladesh. Multivariate statistical analysis, principal component analysis, and correlation matrix yielded the source apportionment of PTEs. Subsequently, carcinogenic and non-carcinogenic health risks were assessed following the approach recommended by the United States Environmental Protection Agency (USEPA) with uncertainty estimation through Monte Carlo simulation. Contamination levels of PTEs followed Cd > Zn > Cr > Cu > Pb > Ni > Mn > As. Concentrations of Cd, Cr, Mn, and Zn were higher than the maximum allowable regulatory limits at storage zone and also higher as compared with the beaching and cutting zones in general. The contamination index indicated extreme Cd contamination in the area with elevated levels in pre-monsoon. Two principal components (PC) were identified-PC1 (Cd, Cu, Mn, Pb, Zn) and PC2 (As, Cr, Ni) inferring their source segmentation. Indirect soil ingestion is the major possible exposure path to PTEs. The health index indicated the absence of any obvious health effects on the people active at SBRI yards in Bangladesh. The carcinogenic risk was for 6 to 7 persons per 100,000 people which was within the USEPA acceptable range.

Environmental hazards associated with open-beach breaking of end-of-life ships: a review.

End-of-life (EOL) ships contribute significantly to the flow of recycled industrial Fe and non-Fe metal materials in resource-poor developing countries. The ship scrapping (breaking) and recycling industry (SBRI) recycles 90-95% of the total weight of EOL ships and is currently concentrated in Bangladesh, India, Pakistan, Turkey, and China, due to the high demand for recyclable and reusable materials there, an abundance of low-cost labor, and lenient environmental regulations. However, the SBRI has long been criticized for non-compliance with standards relating to occupational health, labor safety, and to the management of hazardous materials. Among the different EOL recycling options, Bangladesh, India, and Pakistan use open beaching, a technique that exposes all spheres of the environment to the release of hazardous materials from EOL ships. This article summarizes the current state of knowledge on the environmental exposure of hazardous materials from SBRI, to judge the risks associated with the dismantling of EOL ships on open beaches. Our work includes an overview of the industry and its recent growth, compares available ship-breaking methods, provides an inventory of hazardous releases from EOL ships, and reviews their movement into different spheres of the environment. The economic dynamics behind open beaching, and apportionment of responsibility for hazards related to it, are discussed, in order to generate policy and legal recommendations to mitigate the environmental harm stemming from this industry.

Trends and advances in food analysis by real-time polymerase chain reaction.

Analyses to ensure food safety and quality are more relevant now because of rapid changes in the quantity, diversity and mobility of food. Food-contamination must be determined to maintain health and up-hold laws, as well as for ethical and cultural concerns. Real-time polymerase chain reaction (RT-PCR), a rapid and inexpensive quantitative method to detect the presence of targeted DNA-segments in samples, helps in determining both accidental and intentional adulterations of foods by biological contaminants. This review presents recent developments in theory, techniques, and applications of RT-PCR in food analyses, RT-PCR addresses the limitations of traditional food analyses in terms of sensitivity, range of analytes, multiplexing ability, cost, time, and point-of-care applications. A range of targets, including species of plants or animals which are used as food ingredients, food-borne bacteria or viruses, genetically modified organisms, and allergens, even in highly processed foods can be identified by RT-PCR, even at very low concentrations. Microfluidic RT-PCR eliminates the separate sample-processing step to create opportunities for point-of-care analyses. We also cover the challenges related to using RT-PCR for food analyses, such as the need to further improve sample handling.

Toward the development of smart and low cost point-of-care biosensors based on screen printed electrodes.

Screen printing technology provides a cheap and easy means to fabricate disposable electrochemical devices in bulk quantities which are used for rapid, low-cost, on-site, real-time and recurrent industrial, pharmaceutical or environmental analyses. Recent developments in micro-fabrication and nano-characterization made it possible to screen print reproducible feature on materials including plastics, ceramics and metals. The processed features forms screen-printed disposable biochip (SPDB) upon the application of suitable bio-chemical recognition receptors following appropriate methods. Adequacy of biological and non-biological materials is the key to successful biochip development. We can further improve recognition ability of SPDBs by adopting new screen printed electrode (SPE) configurations. This review covers screen-printing theory with special emphasis on the technical impacts of SPE architectures, surface treatments, operational stability and signal sensitivity. The application of SPE in different areas has also been summarized. The article aims to highlight the state-of-the-art of SPDB at the laboratory scale to enable us in envisaging the deployment of emerging SPDB technology on the commercial scale.

Rapid detection for primary screening of influenza A virus: microfluidic RT-PCR chip and electrochemical DNA sensor.

Rapid and definitive diagnosis is critical to the prevention of the spread of endemic human pathogenic viruses. Detection of variant specific genes by reverse transcription polymerase chain reaction (RT-PCR) has become a routine diagnostic test for accurate subtyping of RNA viruses, such as influenza. In this paper, we demonstrate the use of a continuous-flow polydimethylsiloxane (PDMS) microfluidic RT-PCR chip and disposable electrical printed (DEP) chips for rapid amplification and sensing of new influenza (AH1pdm) virus of swine-origin. The RT-PCR chip consisted of four zones: RT reaction zone, initial denaturation zone, thermal cycle zone for PCR (2-step PCR) and pressurizing-channel zone for preventing air-bubble formation. In order to measure electrochemical signals, methylene blue (MB), an electro-active DNA intercalator, was added to the RT-PCR mixture. The RT-PCR was completed within 15 min which was the total flow-through time from the inlet to the outlet, and the reduction signals from amplifications could be detected quickly on the DEP chip. The MB reduction current on the DEP chip with the amplicon significantly reduced compared to non-amplified controls. This microfluidic platform for rapid RT-PCR and the DEP chip for quick electrochemical sensing are suitable for integration, and have the potential to be a portable system for diagnostic tests.

Non-invasive characterization of mouse embryonic stem cell derived cardiomyocytes based on the intensity variation in digital beating video.

The interest in cardiomyocytes derived from differentiation of embryonic stem (ES) cells or induced pluripotent stem (iPS) cells is increasing due to their potential for regenerative therapeutics and as a pharmaceutical model of drug screening. Characterization of ES or iPS derived cardiomyocytes is challenging and inevitable for the intended usage of such cells. In this paper we have outlined a novel, non-invasive method for evaluating in vitro beating properties of cardiomyocytes. The method is based on the analysis of time dependent variation in the total pixel intensities in derivative images obtained from the consecutive systolic and diastolic frames from the light microscopic video recordings of beating tissue. Fast Fourier transform (FFT) yielded the frequency domains for these images. The signal to noise ratio for the analysis met the Rose criterion. We have successfully applied our method for monitoring mouse ES cell (mESC) derived cardiac muscle cells to determine the initiation of beating, organization and maturation of beating tissue, calculating the beating rhythms in terms of beating interval or frequency and the strength of beating. We have shown the successful application of our image analysis method in direct monitoring of the responses of differentiated cardiomyocytes towards caffeine hydrate, p-hydroxyphenylacetamide and calcium chloride dehydrate - respectively as positive, neutral and negative inotropic agents. This non-invasive method of characterization will be useful in studying the response of these cells to various external stimulations, such as differentiation promoting agents or treatments, as well as in preliminary drug screening in a quick and inexpensive manner without needing much expertise.