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Natural deep eutectic solvents (NADESs) as green solvents have substantial potential for enhancing the solubility of pharmaceuticals in aqueous solutions. In this work, the solubility of two B vitamins (nicotinic acid and 4aminobenzoic acid) in aqueous solutions of two NADESs was measured at temperatures between 298.15 K and 313.15 K and different concentrations of NADESs. The studied NADESs were prepared by mixing dried choline chloride with urea or malonic acid with molar ratios of 1:2 and 1:1, respectively. Based on the results, chloride+malonic acid was more effective on the solubility of the pharmaceuticals in aqueous solutions. Furthermore, the DESs increased the aqueous solubility of 4aminobenzoic acid more than that of nicotinic acid. The experimental solubility data were modeled with the van Laar activity model as well as the modified Apelblat equation to correlate the solubility of the pharmaceuticals to the temperature and NADESs concentration. The molar enthalpy of dissolution (Δhd) and the molar enthalpy of mixing (Δhmix) of the pharmaceuticals in the aqueous solutions of the NADESs were calculated. These parameters showed that all the dissolution processes were endothermic, while the mixing process as a part of the dissolution process was exothermic.

A multitude of structural health monitoring options are currently being investigated to address the reliability of concrete infrastructures at different stages of their service life. This review presents the recent achievements in the field of sensors developed for monitoring the health of concrete infrastructures. The focus of this review is on sensors developed for monitoring parameters including temperature, humidity, pH, corrosion rate, and stress/strain and the sensors particularly fabricated based on fiber optic, Bragg grating, piezoelectric, electrochemical, wireless and self-sensing technologies. Several examples of developed concrete monitoring sensors (from laboratory concepts to commercialized products) together with their various benefits and drawbacks as well as open research problems will be discussed in this paper.

Prolonged exposure to low pH conditions affects the durability of concrete. In this work, the effect of mullite, aluminum silicate, on the strength and the acid corrosion of mortar and concrete under induced accelerated conditions in sulfuric acid solutions at pH of 0.25 and 1 was studied. The characterization of physicochemical changes was performed using techniques including compressive strength, scanning electron microscopy, micro-X-ray fluorescence spectrometry, and the Vickers hardness test. The results indicate that the addition of mullite does not have any significant effect on the overall strength of mortar and concrete samples, while it significantly increases their resistance to corrosion caused by sulfate attack by 90%, therefore, it is expected to increase the life span and decrease the maintenance costs of concrete pipes subjected to acid corrosion in sewer environments. The inhibition efficiency is observed to be sensitive to acid concentration and was improved with increase in the amount of mullite in samples.

Controlled synthesis of hollow polymeric nanocapsules has attracted significant attention in a wide range of applications. This paper reports a facile method for the synthesis of hybrid starch nanocapsules decorated with silver nanoparticles using the inverse miniemulsion polyaddition technique. Silver nanoparticles are formed and embedded in the shell of the nanocapsules during the polyaddition process without using any additional reducing agents. We found that silver also acts as a lipophobe that builds up osmotic pressure in the droplets facilitating the formation of stable round shaped nanocapsules. The nanocapsules' shell thickness could be tuned from 13 to 29 nm by varying the amount of cross-linker. We investigated the minimum inhibitory concentration (MIC) of the nanocapsules against Staphylococcus epidermidis ATCC 35984 and Escherichia coli ATCC 25922 which are two bacteria of medical relevance. The silver nanoparticle decorated nanocapsules showed antibacterial properties against both bacteria at the MIC of 2.315 mu g mL(-1) while control nanocapsules without silver had no antibacterial activity. Refereed/Peer-reviewed

The present study aimed to study the formation, enrichment, and relocation of iron-rich regions in the corroded area of concrete blocks, made without rebar, subjected to severely corrosive highly acidic conditions. In this work, three different concrete mix designs (a proprietary ready-mixed concrete, and laboratory made mortar and concrete) were corroded under induced accelerated conditions in sulfuric acid solutions at pH 1 for a duration of one to six months, in the absence of reinforcement (i.e. rebar) or iron-oxidizing bacteria. A variety of physicochemical and mechanical techniques were applied to monitor and assess the corrosion progress, and physical and chemical changes in the corroded samples. Results indicated a pronounced presence of iron rich layer (iron oxide/hydroxide) at the border of the corrosion front and the transition zone in all mix designs in the form of a ring. While existing papers in the literature describe the iron coming from the rebar, the only source of mobile iron in this experiment was from the iron oxide (Fe2O3) already in the cement. This zone (in a form of a ring) had an average iron content of 2.0 wt% and moved away from the surface to the center of the samples submerged in a sulfuric acid bath with the increase of immersion time, and it was accompanied by hairline cracks. The movement of this zone was in the same direction as sulfate (from acidic media) ingress and the opposite direction of calcium ion leaching, (Ca leaching). The rate of corrosion, the hardness and the compressive strength of concrete are mostly affected by the concrete mix design, the iron-ring enrichment and relocation had no significant impact on them. Detection of the iron-rich zone is an indication of the depth of corrosion at advanced stages in concrete products.

Sustainable management of urban wastewater networks is a global problem where sewer pipes are plagued by numerous harsh conditions causing concrete attack. The end result is premature pipe failure that comes with high financial, public health and environmental costs. Currently, water utilities do not have an in-situ, online monitoring capability for their concrete wastewater assets as conventional electrical sensors fail within a few weeks of installation due to the chemically harsh gaseous environment. Here we outline the development of robust fibre Bragg grating (FBG) sensors to optically measure concrete corrosion rates in wastewater environments over long time periods.

© The Author(s) 2018. In this article, a piezoelectric-based sensory technique is proposed for detection of the gap between surfaces of a carbon fiber reinforced polymer plate and a concrete specimen and characterization of shrinkage of early-age concrete. The proposed technique uses the propagation properties of the guided waves in the carbon fiber reinforced polymer plate excited and received by piezoelectric transducers attached to an external surface of the carbon fiber reinforced polymer–strengthened concrete specimen. Measurements are conducted with fresh and hardened early-age concrete specimens and two carbon fiber reinforced polymer plates at different gaps. A piezoelectric actuator is excited using a sine burst signal, and the generated wave is received by a sensor after propagation along the specimen. The received signal at different gap values is used to detect a gap. To quantify the gap, damage indices, including correlation coefficient, peak-to-peak amplitude of resultant signal, and root-mean-square deviation, are used. The shrinkage of concrete is detected and predicted by comparing the damage indices at different gaps with the indices at different stages of early-age concrete. The proposed technique is relatively simple method using small transducers. It is one-sided, non-destructive, and cost-effective solution for gap detection and concrete characterization.

Health geography emphasizes landscape capacity as a perspective for examining health dimensions. Much of this emphasis is on the concept of therapeutic landscapes. In the last two decades, changes in the therapeutic landscapes concerning health, as well as why and how the development of the emphasis on the dimensions of the health in the landscape in proportion to the temporal-spatial course of literature in this field can be considered. The framework of the present study is based on a systematic review of therapeutic landscapes in the geography of health in the last two decades. This systematic literature review followed the PRISMA guidelines. Searching for "Therapeutic Landscapes" term at Science Direct and PubMed, screening, 56 eligible articles were selected in the journal Social Science and Medicine, and Health and Place. The results of the systematic review, aiming to search for the health dimensions of the therapeutic landscape, and recognize main gaps, identified three main issues: scale and range of users of therapeutic landscapes, the position importance of experiences in therapeutic landscapes, therapeutic landscapes as the holistic paradigm. The results of the research show that in recent years, attention to multiple dimensions of health, especially non-physical relationships of therapeutic landscapes and multiple dimensions of health, has been considered more and more by researchers. Personal-social perceptions and experiences are also continually evolving, so the concept of therapeutic landscapes and its relationship to health is considered living and dynamic.

Unexplainable concrete softening below the water line has been observed by Sydney Water in their gravity sewer network, some of which is subjected to corrosion control methods using chemical ferrous chloride (FeCl2) dosing of the wastewater. We applied a combination of physical and chemical tools to determine the properties of the top 20 mm of concrete cores recovered from sewer pipes. These techniques consist of neutron tomographic imaging, scanning electron microscopy, hardness mapping, and pH profiling. Concrete cores were collected from roof (crown), tidal (wall) and below flow regions of gravity sewer pipes of Sydney Water's wastewater system from locations that received no treatment as well as locations dosed with FeCl2. All samples showed a degree of softening of the surface exposed to the sewerage with an associated depletion in calcium concentration and reduced pH in the same regions.

The combination of Neutron Tomography (NT), Scanning Electron Microscopy (SEM, with and without elemental analysis), pH profiling and Microindentation Mapping techniques was used to develop a methodology for the assessment of concrete sewer pipe deterioration. We demonstrate a viable method for health monitoring of concrete sewer pipes and the evaluation of competing mitigation strategies.

Surface nanoengineering is a valuable tool to create materials with sophisticated properties required to address unmet needs in fields such as medicine, biology or energy. This study examines the dependence of nanoparticle immobilization as a function of surface amine group density. The concentration of surface amine groups was tuned using gradients deposited from the plasma phase of allylamine and octadiene (pp-AA/OD) precursors mixtures. Silver nanoparticles capped with carboxylic acid groups (COOH-AgNPs) were used to interrogate the effect of primary amine (−NH2) surface density on nanoparticle's electrostatic immobilization onto freshly made and aged plasma polymer films. An increase in amine group density could be correlated with greater number of functionalized silver nanoparticles bound to the surface. In addition, the pp-AA/OD surface charge and nanoparticle binding density could be controlled via pH of the AgNPs colloidal solution. The results suggest that pp-AA/OD plasma polymer films are suitable platforms for implementing advanced nanoengineered materials that could be used in many advanced applications, ranging from medicine to sensing and electronics. Refereed/Peer-reviewed

The quantification of primary and secondary amines in plasma polymerized allylamine and plasma copolymers of allylamine/octadiene films was carried out using chemical derivatization followed by X-ray photoelectron spectroscopy. Data was analyzed using a combination of the peak-fit-analysis method (PFA) and the quantitative-elemental-analysis method (QEA). The latter method overestimates the secondary amine contribution, since it does not account for the additional reaction of TFAA with OH groups that may be present as a result of surface aging effects. In the current work the PFA method has been extended to enable the separation of –OH groups and secondary amines, thus allowing for a more precise determination of the secondary amine groups even after surface aging.

Antibacterial coatings have been accepted as a potent solution to the problem of medical-device-associated infections, which affect millions of patients worldwide. In this work, we present silver-nanoparticle-based antibacterial coatings that are highly potent against medi- cally relevant bacteria such as S. epidermidis and S. aureus but do not have apparent cytotoxicity to primary human fibroblast cells. The silver nanoparticles used in the coatings are synthesized in the presence of trisodium citrate. At a given moment, 2-mercaptosuccinc acid is added to allow for reduction of nanoparticle size and to provide the well-defined surface architecture necessary for controllable surface immobilization. Important for application, the technology is facilitated by a functional-plasma-deposited polymer interlayer. This makes it applicable to the surface of medical devices manufactured from any type of material.

Na 2 S/Al 2 O 3 catalyzed the Knoevenagel condensation between an aldehyde and an active methylene compound to yield various trisubstituted alkenes.

Cupric sulfate pentahydrate is an efficient catalyst for a one-pot synthesis of quinoxaline derivatives. The reaction can be performing in water as well as ethanol. The procedure presented is operationally simple, practical and green.

Medical device associated infections are a persistent medical problem which has not found a comprehensive solution yet. Over the last decades, there have been intense research efforts toward developing antibacterial coatings that could potentially improve medical outcomes. Silver nanoparticles have attracted a great deal of attention as a potent alternative to conventional antibiotics. Herein, we present a biologically inspired approach to synthesize phospholipid encapsulated silver nanoparticles and their surface immobilization to a functional plasma polymer inter layer to generate antibacterial coatings. The antibacterial efficacy of the coatings was evaluated against three medically relevant pathogens including the Gram-positive Staphylococcus aureus and Staphylococcus epidermidis, and the Gram-negative Pseudomonas aeruginosa. The innate immune response to the coatings was assessed in vitro using primary bone marrow derived macrophages (BMDM). Any potential cytotoxicity was studied with primary human dermal fibroblasts (HDFs). Overall, the coatings had excellent inhibition of bacterial growth. We also observed reduced expression of pro-inflammatory cytokines from BMDM which suggests a reduced inflammatory response. The combined properties of coatings developed in this study may make them a good candidate for application on medical devices such as catheters and wound dressings. Refereed/Peer-reviewed

Cupric sulfate pentahydrate was found to be an efficient catalyst for the protection of aldehydes as 1,1-diacetates in high yields in a solvent-free system at room temperature. Ketones are not affected under these reaction conditions.

Infections associated with medical devices are a substantial healthcare problem. Consequently, there has been increasing research and technological efforts directed toward the development of coatings that are capable of preventing bacterial colonization of the device surface. Herein, we report on novel hybrid silver loaded poly(L-lactic acid) nanoparticles (PLLA-AgNPs) with narrowly distributed sizes (17 ± 3 nm) prepared using a combination of solvent evaporation and mini-emulsion technology. These particles were then immobilized onto solid surfaces premodified with a thin layer of allylamine plasma polymer (AApp). The antibacterial efficacy of the PLLA-AgNPs nanoparticles was studied in vitro against both gram-positive (Staphylococcus epidermidis) and gram-negative (Escherichia coli) bacteria. The minimal inhibitory concentration values against Staphylococcus epidermidis and Escherichia coli were 0.610 and 1.156 μg centerdot mL⁻¹, respectively. The capacity of the prepared coatings to prevent bacterial surface colonization was assessed in the presence of Staphylococcus epidermidis, which is a strong biofilm former that causes substantial problems with medical device associated infections. The level of inhibition of bacterial growth was 98%. The substrate independent nature and the high antibacterial efficacy of coatings presented in this study may offer new alternatives for antibacterial coatings for medical devices. Refereed/Peer-reviewed

Infections arising from bacterial adhesion and colonization on medical device surfaces are a significant healthcare problem. Silver based antibacterial coatings have attracted a great deal of attention as a potential solution. This paper reports on the development of a silver nanoparticles based antibacterial surface that can be applied to any type of material surface. The silver nanoparticles were surface engineered with a monolayer of 2-mercaptosuccinic acid, which facilitates the immobilization of the nanoparticles to the solid surface, and also reduces the rate of oxidation of the nanoparticles, extending the lifetime of the coatings. The coatings had excellent antibacterial efficacy against three clinically significant pathogenic bacteria i.e. Staphylococcus epidermidis, Staphylococcus aureus and Pseudomonas aeruginosa. Studies with primary human fibroblast cells showed that the coatings had no cytotoxicity in vitro. Innate immune studies in cultures of primary macrophages demonstrated that the coatings do not significantly alter the level of expression of pro-inflammatory cytokines or the adhesion and viability of these cells. Collectively, these coatings have an optimal combination of properties that make them attractive for deposition on medical device surfaces such as wound dressings, catheters and implants. Refereed/Peer-reviewed

MnCl2 efficiently catalyzes the condensation of o-phenylenediamine derivatives with 1,2-diketones at room temperature to afford the corresponding quinoxaline derivatives in high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:218–220, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20401

The synthesis of 2,4,5-triaryl-imidazoles from benzyl, aldehydes and NH4OAc, as ammonia source, in the presence of catalytic amount of NiCl2·6H2O supported onto acidic alumina in very good yields under heterogeneous system is reported.

The increasing use of silver (Ag) nanoparticles [containing either elemental Ag (Ag-NPs) or AgCl (AgCl-NPs)] in commercial products such as textiles will most likely result in these materials reaching wastewater treatment plants. Previous studies indicate that a conversion of Ag-NPs to Ag2S is to be expected during wastewater transport/treatment. However, the influence of surface functionality, the nature of the core structure and the effect of post-processing on Ag speciation in sewage sludge/biosolids has not been investigated. This study aims at closing these knowledge gaps using bench scale anaerobic digesters spiked with Ag nitrate, three different types of Ag-NPs, and AgCl-NPs at environmentally realistic concentrations. The results indicate that neither surface functionality nor the different compositions of the NP prevented the formation of Ag2S. Silver sulfides, unlike the sulfides of other metals present in sewage sludge, were stable over a six month period simulating composting/stockpiling. Refereed/Peer-reviewed

Recently, surface gradients have attracted significant interest for various research and technological applications. In this paper, we report a facile and versatile method for generating surface gradients of immobilized nanoparticles, nanotopography and ligands that is independent from the substrate material. The method consists of first depositing a functional polymer layer on a substrate and subsequent time controlled immersion of this functionalized substrate in solution gold nanoparticles (AuNPs), silver nanoparticles (AgNPs) or poly (styrenesulfonate) (PSS). Chemical characterization by X-ray Photoelectron Spectroscopy (XPS) and morphological analysis by Atomic Force Microscopy (AFM) show that the density of nanoparticles and the concentration of PSS across the surface increases in a gradient manner. As expected, time of immersion determines the concentration of surface bound species. We also demonstrate the generation of surface gradients of pure nanotopography. This is achieved by depositing a 5 nm thick plasma polymer layer on top of the number density gradient of nanoparticles to achieve a homogeneous surface chemistry. The surface independent approach for generation of surface gradients presented in this paper may open opportunities for a wider use of surface gradient in research and in various technologies. Refereed/Peer-reviewed

MnCl2 efficiently catalyzes the condensation of o-phenylenediamine derivatives with 1,2-diketones at room temperature to afford the corresponding quinoxaline derivatives in high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:218–220, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20401

A facile synthesis of quinoxaline derivatives catalyzed by KHSO4 in very high yields at room temperature is reported.

Bacterial infections are continuing to pose a significant threat to human health. Coatings with inherent antibacterial properties are becoming increasingly common as an infection preventative measure. The aim of this review is to highlight recent progress in development of "smart" and responsive antibacterial surfaces. The review describes various strategies utilized for generation of such surfaces and the specific stimuli that are used to trigger antibacterial action. It also provides a critical discussion of the advantages and drawbacks of different approaches. The review concludes with a perspective about the future of the field and outlines the challenges and obstacles that need to be overcome in order to make future advances. Refereed/Peer-reviewed

A simple, mild, effective and green method to form acylals from aliphatic and aromatic aldehydes in good to excellent yields in the presence of potassium hydrogen sulfate, KHSO4, as catalyst under solvent-free conditions is described. Ketones are not affected under the reaction conditions.