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Stormwater infiltration basins have been used extensively around the world to restore urban hydrology towards more natural flow and water quality regimes. There is, however, significant uncertainty in the fate of infiltrated water and accompanying contaminants that depends on multiple factors including media characteristics, interactions with downslope vegetation, legacy contaminants, and presence of underground infrastructure. Understanding the influence of such factors is thus central to the design and siting of infiltration basins. An extensive field program was established to collect monthly data on ground water quality, including nutrients and major ion concentrations, in a bore network downstream of a stormwater infiltration basin in Victoria, Australia. The groundwater samples were analysed for temperature, pH, EC, turbidity, major ions (Na+, Ca2+, K+, Mg2+, Cl−, SO42−, NO3−, CO32−, HCO3−), NOx and heavy metals. The collected data were used to understand the origin and fate of water and solutes in the subsurface and their interactions with the soil matrix. The results revealed that Ca–HCO3, Na–Cl water types predominate in the study area, grouped in 3 clusters; shallow fresh groundwater in the vicinity of the basin (near basin), deep saline groundwater further downstream of the basin (near-stream) and a mid-section where rock-water interaction (Na–HCO3 water) through cation exchange control the chemistry of groundwater. The results also suggest that as the water moves downstream of the basin, it experiences significant evapotranspiration and concentration due to the presence of deep-rooted vegetation. The results suggest that while infiltration basins can remove infiltrated contaminants, the infiltrated stormwater can mobilise legacy contaminants such as nitrate. Overall, the efficacy of infiltration basins in urban regions depends substantially on the downstream vegetation, urban underground infrastructure and the presence of legacy contaminants in the soils. These all need to be considered in the design of stormwater infiltration basins. [ABSTRACT FROM AUTHOR]

Successful management of type 2 diabetes mellitus (T2DM), a complex and chronic disease, requires a combination of anti-hyperglycemic and anti-inflammatory agents. Here, we have conceptualized and tested an integrated “closed-loop mimic” in the form of a glucose-responsive microgel (GRM) based on chitosan, comprising conventional insulin (INS) and curcumin-laden nanoparticles (nCUR) as a potential strategy for effective management of the disease. In addition to mimicking the normal, on-demand INS secretion, such delivery systems display an uninterrupted release of nCUR to combat the inflammation, oxidative stress, lipid metabolic abnormality, and endothelial dysfunction components of T2DM. Additives such as gum arabic (GA) led to a fivefold increased INS loading capacity compared to GRM without GA. The GRMs showed excellent invitro on-demand INS release, while a constant nCUR release is observed irrespective of glucose concentrations. Thus, this study demonstrates a promising drug delivery technology that can simultaneously, and at physiological/pathophysiological relevance, deliver two drugs of distinct physicochemical attributes in the same formulation. [ABSTRACT FROM AUTHOR]

Index-based methods estimate a fixed value of groundwater vulnerability (GWV); however, the effects of time variations on this estimation have not been comprehensively studied. It is imperative to estimate a time-variant vulnerability that accounts for climatic changes. In this study, we used a Pesticide DRASTICL method separating hydrogeological factors into dynamic and static groups followed by correspondence analysis. The dynamic group is composed of depth and recharge, and the static group is composed of aquifer media, soil media, topography slope, impact of vadose zone, aquifer conductivity and land use. The model results were 42.25–179.89, 33.93–159.81, 34.08–168.74, and 45.56–205.20 for spring, summer, autumn, and winter, respectively. The results showed a moderate correlation between the model predictions and observed nitrogen concentrations with R2 = 0.568 and a high correlation for phosphorus concentrations with R2 = 0.706. Our results suggest that the time-variant GWV model provides a robust yet flexible method for investigating seasonal changes in GWV. This model is an improvement to the standard index-based methods, making them sensitive to climatic changes and portraying a true vulnerability estimation. Finally, the correction of the rating scale value fixes the problem of overestimation in standard models. [ABSTRACT FROM AUTHOR]

Infiltration systems are increasingly used to reduce peak flows and mitigate the impacts of stormwater runoff. Despite the benefits of infiltration systems, there is a risk for associated pollutants, including heavy metals to be introduced to the underlying soil and groundwater. The subsequent movement of metals in the subsurface and their potential to contaminate water resources is uncertain and profoundly depends on the adsorptive behavior of the surrounding soil. We used two soil types, one natural (quartz–kaolinite–muscovite) and one synthetic (quartz and kaolinite only) with different clay mineralogy to test their potential adsorptive capacities through batch systems, with Zn(II) as a representative tracer. Nonlinear isotherms, Freundlich and Langmuir, provided good fits with the experimental sorption data. Kinetic data were well fitted by a pseudo-second-order model, indicating that cation exchange exists between the clay surfaces and Zn(II) in the liquid phase. We found that the natural soil adsorbed far more Zn(II) when compared to the synthetic soil which was attributed to the presence of the muscovite in the natural soil. Comparison of the observed adsorption capacity of the two soils with their predicted adsorption capacities showed that while the adsorption capacities of the single-sized clay minerals are widely reported, these values cannot be linearly extrapolated to estimate the adsorption capacity of a soil that might contain varied fractions of clay. The results suggest that the designers of infiltration systems should first undertake an analysis of clay mineralogy of the subsurface soil to better predict the fate of heavy metals within the surrounding soils. Article Highlights: We investigate the impact of soil clay minerals on zinc ion immobilization. Muscovite significantly contributes to zinc ion sorption. The soil sorption capacity cannot be estimated from its individual mineral sorption capacities. Sorption of zinc ion in the soil is chemically rather than physically modulated. [ABSTRACT FROM AUTHOR]

Chickpea (Cicer arietinum L.) genotypes are sensitive to low temperature (<10°C) during its reproductive stage suffer from abortion of flowers, infertile pods and small shriveled seeds that resulted in a significant decrease in crop yield. In the present investigation seeds of a number of cold stress-tolerant and susceptible genotypes were evaluated for biochemical and molecular diversity with the purpose to categorize them. The activities of various antioxidative enzymes (superoxide dismutase, glutathione reductase, ascorbate peroxidase and catalase), content of HO and malondialdehyde, enzymes involved in phosphate metabolism (acid and alkaline phosphatases), and content of phytic acid and proline were determined in seeds of 20 cold stress tolerant and seven cold stress susceptible genotypes. Higher activities of superoxide dismutase, ascorbate peroxidase, catalase and acid phosphatase and low content of malondialdehyde and phytic acid were observed in cold stress-tolerant genotypes as compared to cold stress susceptible genotypes. Seventeen chickpea genotypes comprising both cold stress-tolerant and susceptible ones were evaluated through 20 randomly amplified polymorphic DNA (RAPD) primers. The results of cluster analysis revealed two major groups. In the first group five tolerant (group 1a) and six susceptible genotypes (group 1b) clustered together whereas in second group all the tolerant genotypes clustered together (group 2). Out of 20 RAPD primers, 4 primers (Opa-13, Opa-14, Opa-15 and Opa-16) have been identified as markers for cold stress tolerance. In general high SOD activity, and HO content and low MDA and phytic acid content are related with cold stress tolerance. The status of these markers was more pronounced in genotypes clustered in group 2 after RAPD analysis than in group 1a of cold stress-tolerant genotypes as compared to susceptible genotypes. The observed biochemical and molecular diversity could be useful for identifying and developing cold stress-tolerant genotypes of chickpea. [ABSTRACT FROM AUTHOR]

Myeloid-derived suppressor cells (MDSCs) have been investigated largely in the context of tumor progression. In contrast to the negative connotation of MDSCs in cancer immunity, our laboratory has recently reported on the development and role of pulmonary MDSC-like cells (CD11bGr1F4/80) in the regulation of allergic airway inflammation. These regulatory cells were expanded in a TLR4/MyD88-dependent manner and were both phenotypically and morphologically similar to those described in the tumor microenvironment. Although bacterial lipopolysaccharide (LPS) was initially described as an adjuvant in the development of allergic inflammation, subsequent studies showed that this is true only at relatively low doses of LPS. A high dose of LPS was shown to actually suppress eosinophilic airway inflammation. In our efforts to understand the mechanism underlying LPS-mediated suppression of allergic airway disease, we recently showed that LPS induces MDSC-like cells in the lung tissue in a dose-dependent manner, with increased accumulation of the cells at high doses of LPS. In contrast to lung dendritic cells (DCs), the MDSC-like cells did not traffic to the lung-draining lymph nodes, allowing them to act in a dominant fashion over DCs in the regulation of Th2 responses. The MDSC-like cells were found to blunt the ability of the lung DCs to upregulate GATA-3 or to promote STAT5 activation in primed Th2 cells, both transcription factors having critical roles in Th2 effector function. Thus, a complete understanding of the generation and regulation of the lung MDSCs would provide novel options for therapeutic interventions. [ABSTRACT FROM AUTHOR]

Hyperfiltration and nanofiltration membranes were tested with different water matrices for the removal of excess fluoride from underground water. Initially, the experiments were done with synthetic samples prepared by adding known amounts of sodium fluoride and calcium chloride in distilled water. The effect of feed water composition, pH, temperature of feed water, operating pressure, and feed water flow rate on separation efficiency of both types of membrane was studied by varying one parameter at a time and keeping all other parameters constant. Thus, the optimum operating conditions for the process were determined and after that ground water samples collected from three villages of district Gurgaon, Haryana, India (Farukhnagar, Wazirpur, and Mevka) were treated under optimum operational conditions. The mass transfer coefficient and membrane parameters were estimated for each data point using two-parameter model (Film theory and Solution-diffusion model) to study the concentration polarization on membrane surface. The nanofiltration membrane showed high percentage rejection of bivalent ions when compared to monovalent ions in a binary system. But in multicomponent system, when fluoride and calcium coexisted, the removal of fluoride was comparable to calcium removal because of the low solubility product of calcium fluoride. The results with RO membrane revealed that it removes practically all the ions present in water at high pressure, which need to be passed through a lime column to remineralize the water, to make it suitable for drinking purposes, whereas by running the system at low pressure which will further reduce the cost of operation, rejection percentage goes down to get permeate of required quality. [ABSTRACT FROM AUTHOR]

Supramolecular gels, which demonstrate tunable functionalities, have attracted much interest in a range of areas, including healthcare, environmental protection and energy-related technologies. Preparing these materials in a reliable manner is challenging, with an increased level of kinetic defects observed at higher self-assembly rates. Here, by combining biocatalysis and molecular self-assembly, we have shown the ability to more quickly access higher-ordered structures. By simply increasing enzyme concentration, supramolecular order expressed at molecular, nano- and micro-levels is dramatically enhanced, and, importantly, the gelator concentrations remain identical. Amphiphile molecules were prepared by attaching an aromatic moiety to a dipeptide backbone capped with a methyl ester. Their self-assembly was induced by an enzyme that hydrolysed the ester. Different enzyme concentrations altered the catalytic activity and size of the enzyme clusters, affecting their mobility. This allowed structurally diverse materials that represent local minima in the free energy landscape to be accessed based on a single gelator structure. [ABSTRACT FROM AUTHOR]

In recent years field test kits have been largely used to identify arsenic (As) levels in contaminated water sources in Bangladesh, West Bengal (India), and elsewhere in the world to establish whether or not the water is safe. Most of the kits are based on the reaction of arsine gas with some chemical agent to form a coloured complex; the intensity of the colour is compared visually with a colour-coded chart or measured electronically to calculate the concentration of As in the water sample. In this paper, a step-wise review is presented of the analytical process used in the most commonly available As field test kits and the associated shortcomings of each of these kits. We also identify the research gaps for future work to enhance the accuracy and reliability of test results produced by these kits. [ABSTRACT FROM AUTHOR]

Summary: The normal-phase (NP) and reversed-phase (RP) thin-layer chromatographic separations of aminoglycosides (streptomycin, kanamycin, gentamycin, and tobramycin) have been investigated on silica gel and C18 plates, respectively. The mobile phase acetone–2% sodium acetate–acetic acid–butanol, 7 + 6 + 4 + 1 (v/v) was successful for NPTLC and acetonitrile–5 mM sodium acetate buffer (pH 4.6) 4 + 18 (v/v) for RPTLC. The spots were located by use of iodine vapor. The minimum detection limits were in the range 0.4–0.6 μg. The method is a simple and direct approach for detection which does not require pre- or post-chromatographic derivatization. [ABSTRACT FROM AUTHOR]

The permeability of sediments at the sediment–water interface is an important control on several stream ecosystem services. It is well known that streambed permeability varies over several orders of magnitude, however, the environmental processes influencing this variation have received little attention. This review synthesizes the state-of-art knowledge and gaps in our understanding of the key physical and biological processes which can potentially modify the streambed permeability. These processes include—(a) physical clogging due to fine sediments, (b) biological clogging due to microbial biomass, and (c) sediment reworking by in-stream fauna. We highlight that the role of biotic processes (bioclogging and sediment reworking processes) in modifying the streambed permeability has not been investigated in detail. We emphasize that complex feedback mechanisms exist between these abiotic and biotic processes, and an interdisciplinary framework is necessary to achieve a holistic understanding of the spatio-temporal variability in streambed permeability. To this end, we propose to develop a conceptual model for streambed evolution after a disturbance (e.g. floods) as this model could be valuable in comprehending the dynamics of permeability. We also outline the challenges associated with developing a widely applicable streambed evolution model. Nonetheless, as a way forward, we present a possible scenario for the evolution of a streambed following a high flow event based on the trajectory of responses of the above-mentioned environmental processes. Finally, we suggest future research directions that could assist in improving the fundamental understanding of the clogging and sediment reworking processes and consequently of the dynamics of streambed permeability. [ABSTRACT FROM AUTHOR]