Tap Water Solution Research Articles

Correction: Efficacy of Hank's balanced salt solution compared to other solutions in the preservation of the periodontal ligament. A systematic review and meta-analysis.

[This corrects the article DOI: 10.1371/journal.pone.0200467.].

Effect of liquid phase rheology and gas–liquid interface property on mass transfer characteristics in bubble columns

Gas–liquid mass transfer in non-Newtonian fluid systems is important in many chemical and biochemical processes. Having a good understanding of gas–liquid mass transfer contributes to achieving the optimization of design and the energy-efficient operation. The mass transfer performance in tap water and carboxyl methyl cellulose (CMC) aqueous solutions with different weight percentages (0.3wt%, 0.4wt%, 0.5wt% and 0.6wt%) were investigated experimentally. The CMC aqueous solution was shear-thinning non-Newtonian fluid. In this study the apparent viscosity of the solutions ranged from 0.01 to 0.1Pas. As expected, the liquid phase rheology had a great effect on the gas–liquid mass transfer performance. The volumetric mass transfer coefficients in CMC aqueous solutions were much smaller than those in tap water, and the value decreased from 3.04×10−3s−1 to 2.8×10−4s−1 with the increase of the weight percentage of CMC aqueous solutions. The mobility of the gas–liquid interface in tap water and CMC aqueous solutions was identified by the dimensionless diameter number. It was found that the mobile gas–liquid interface prevailed in tap water, while bubbles behaved as rigid particles in relatively high weight percentage of CMC aqueous solutions (0.5wt% and 0.6wt%). The liquid film mass transfer coefficient could be approximated by theories for mobile and immobile gas–liquid interfaces in tap water and CMC aqueous solutions, respectively. Based on the liquid phase rheology and the mobility of the gas–liquid interface, the dimensionless correlations were proposed to describe the mass transfer process in Newtonian and non-Newtonian fluids.

"AM I ALLERGIC TO THE OCEAN?": HIVES IN A YOUNG VACATIONING GIRL

Introduction Saline-dependent aquagenic urticaria (SDAU) is a rare form of aquagenic urticaria with Typically 1-3 mm papular lesions, these hives are distributed on the face and neck, affecting mostly adolescent to middle aged women. Onset is usually within 20 minutes of exposure, with resolution within 30 minutes after discontinued exposure. Treatment with antihistamines is typically unsuccessful. Case Description A 7 year old female with chronic spontaneous urticaria and allergic rhinitis presented for evaluation of hives after swimming in the ocean. Onset was at 4.5 years of age; after going in the ocean she developed urticarial lesions on the neck, chest and legs which resolved within 30 minutes of getting out of the water. She developed similar rash on repeat exposure to salinated water in the ocean, salinated pools, and “slime” made with salinated solution, but not with exposure to tap or chlorinated water. Further instances were similarly distributed but later described as a fine papular, pruritic rash, worsening in intensity as she aged despite antihistamine use. In-clinic challenge was completed with gauze soaked with room temperature solutions of tap water, 3.5% saline and 7% saline. After 20 minutes, the gauze was removed and there was erythema and pruritus at the site of the 7% saline solution only. Discussion There have been two described pediatric cases of SDAU. This case is unique in that the patient developed typical urticaria as well as follicular lesions in an atypical distribution (including the chest and legs).

A System for Real-Time Syringe Classification and Volume Measurement Using a Combination of Image Processing and Artificial Neural Networks

The purpose of this research was to develop a system that can read and report the volume of liquid medication present in syringes. The system is comprised of a digital webcam which is designed to communicate with a computer program developed using MATLAB. The system includes two functional modules, one supporting syringe classification, and another supporting volume measurement. Adaptive template matching was used to determine the best match point between target and template images. The connected component labeling method was used during volume measurement. An artificial neural network (ANN) model was developed using MATLAB to support the intended volume measurement functionality. The developed ANN was designed as a classifier which determines the plunger depth of the syringe and then leverages this result to calculate and derive the volume of medication inside the syringe as the final system output. Commercial Luer-lock syringes of sizes from 1 to 30 ml were used in conjunction with syringe tip caps of blue and yellow color. Tap water or aqueous dye solutions of yellow, red, and blue color simulated liquid medication in the syringe. The developed syringe classification system successfully detected and categorized all tested syringes according to their size. The best accuracy of the system was found to be 99.95% with a 3-ml syringe, while the worst accuracy was 95.82% with a 5-ml syringe. It took approximately 6 s to perform the entire task demonstrating the utility of this system to report volumes in real time. The developed system can be used across a variety of settings that routinely support measuring and handling liquids in syringes including hospitals, pharmacies, and the pharmaceutical industry.

Removal of Antimony Species, Sb(III)/Sb(V), from Water by Using Iron Coagulants

Antimony (Sb) is classified as a toxic pollutant of high priority, because its effects on human health (toxicity) are similar to those of arsenic. However, unlike arsenic, the removal of antimony from polluted waters is still not well understood. In the present study the removal of common antimony species in water, namely, Sb(III) and Sb(V), was investigated by the addition of iron-based coagulants. The applied coagulants were Fe(II), Fe(III), and equimolar mixed Fe(II)/Fe(III) salts and the experiments were performed with realistic antimony concentrations in the range 10–100 μg/L, by using artificially polluted tap water solutions. Sb(III) removal by Fe(III) provided better adsorption capacity at a residual concentration equal to the drinking water regulation limit of 5 μg/L, that is, Q5 = 4.7 μg Sb(III)/mg Fe(III) at pH 7, which was much higher than the value achieved by the addition of Fe(II) salts, that is, Q5 = 0.45 μg Sb(III)/mg Fe(II), at the same pH value. Similarly, Sb(V) was more efficiently removed by Fe(III) addition, than by the other examined coagulants. However, Fe(III) uptake capacity for Sb(V) was found to be significantly lower, that is, Q5 = 1.82 μg Sb(V)/mg Fe(III), than the corresponding value for Sb(III). The obtained results can give a realistic overview of the efficiency of conventionally used iron-based coagulants and of their mixture for achieving Sb concentrations below the respective drinking water regulation limit and therefore, they can be subsequently applied for the designing of real-scale water treatment units.

Behaviour of periwinkle shell ash blended cement concrete in sulphuric acid environment

This paper presents the influence of sulphuric acid on compressive strength of concrete made with cement blended with periwinkle shell ash (PSA). The cement component was replaced with PSA at 0 %, 5 %, 10 %, 15 % and 20 %. Concrete mix ratio of 1:2:4 and a constant water cement ratio of 0.6 was used. A total of 180 cube specimens (150mm x 150mm x 150mm) were cast and tested for compressive strength at 7, 14, 21 and 28 days of immersion in potable tap water (as control) and (5 % and 10 %) sulphuric acid solutions. Test results showed that the compressive strength increased with age and decreased with PSA content for specimen cured in water (control); while for specimen cured in sulphuric acid solutions, the compressive strength decreased with age, PSA content as well as sulphuric acid content. The statistical analysis of variance showed that the sulphuric acid concentrations, PSA contents and curing age have effect on the concrete compressive strength. Regardless of the concentration of exposure conditions, it is concluded that PSA did not lighten the adverse effects of sulphuric acid on the compressive strength of cement blended with PSA. http://dx.doi.org/10.4314/njt.v37i2. 5

Electrochemical remediation of amoxicillin: detoxification and reduction of antimicrobial activity

Amoxicillin (AMX) is one of the most commonly prescribed antibiotics around the world to treat and prevent several diseases in both human and veterinary medicine. Incomplete removal of AMX during wastewater treatment contributes to its presence in water bodies and drinking water. AMX is an emerging contaminant since its impact on the environment and human health remains uncertain. This contribution was aimed to evaluate the electrochemical oxidation (EO) of AMX using different anodes in tap water, NaCl or Na2SO4 solutions and to evaluate the potential toxicity of remaining AMX and its by-products on zebrafish early-life stages. Chemical intermediates generated after EO were determined by mass spectrometry and their resulting antimicrobial activity was evaluated. AMX did not induce significant mortality in zebrafish during extended exposure but affected zebrafish development (increased body length) from 6.25 mg/L to 25 mg/L and inhibited enzymatic biomarkers. Carbon modified with titanium oxide (TiO2@C) anode achieved complete AMX removal in just a few minutes and efficiency of the supported electrolytes occurred in the following order: 0.1 M NaCl > 0.1 M Na2SO4 > 0.01 M NaCl > tap water. The order of potential toxicity to zebrafish early life-stages related to lethal and sublethal effects was as follows: 0.1 M Na2SO4 > 0.1 M NaCl >0.01 M NaCl = tap water. Additionally, the EO of AMX using TiO2@C electrode with 0.01 M NaCl was able to inhibit the antimicrobial activity of AMX, reducing the possibility of developing bacterial resistance.

Mass transfer in Taylor flow: Transfer rate modelling from measurements at the slug and film scale

Mass transfer in non-reactive gas–liquid Taylor flow has been studied at the unit cell scale with high resolution non-invasive experimental techniques for a large variety of hydrodynamic regimes at high inertia (30 ≤ Reb ≤ 1430). The planar laser induced fluorescence with inhibition (PLIF-I) technique has been used to measure the local oxygen concentration fields in different liquid phases (tap water, water and Breox solutions at different concentrations) in order to vary the Schmidt number Sc. The concentration field can be separated into a film region, corresponding to the thin lubrication film extended all along the channel wall, and the remainder of the liquid which makes up the slug region. It has been found that even though the global mass transfer is mainly driven by the rate of transfer in the slug, the film plays a significant role as a source of oxygen, in addition to the bubble caps, to feed the slug.In the investigated circular capillary, fed by means of a T-mixer, two contrasted configurations have been observed in the liquid phase (slugs and films), depending on a critical bubble Reynolds number of ∼ 300, where the time-averaged concentration fields are found to differ considerably. For large Reynolds number, particle image velocimetry (PIV) measurements have revealed low temporal fluctuations at the rear of the bubble, possibly due to the presence of adsorbed contaminants, that tends to increase mixing in the slug. Despite this difference, the mass transfer dynamics were found to be controlled in all cases by the intensity of the recirculating motion in the slug, which is directly related to the bubble velocity for these cases of thin films.A new scaling law has been proposed for the overall Sherwood number, based on Reb and Sc, which satisfactorily describes the overall mass transfer of the experimental results for Reb > 120 to an accuracy of ±11%.

Colonic Indole And Hydrogen Sulfide, Gut Bacterial Metabolites, Affect Portal Blood Pressure in Healthy And Cirrhotic Rats

Liver cirrhosis is a leading cause of portal hypertension, and is often accompanied by systemic hypotension. Accumulating evidence suggests that gut bacteria may affect hemodynamics, however, the mechanisms are not clear. We investigated the effect of colon‐administered gut bacteria metabolites on portal blood pressure (PBP), portal blood flow (PBF) and systemic arterial blood pressure (ABP) in healthy (controls) and cirrhotic rats (CRH).10‐week‐old, male, Sprague Dawley rats were maintained either on tap water (controls) or water solution of thioacetamide for 18 weeks to induce liver cirrhosis (CRH). PBP, PBF and ABP were measured in anaesthetized rats at baseline and after the intracolonic administration of either a vehicle, indole, or Na2S, a hydrogen sulfide (H2S) donor into the colon.CRH showed significantly higher PBP but lower ABP than controls. The intracolonic administration of indole increased portal blood level of indole, and peripheral blood level of indoxyl sulfate, a liver metabolite of indole. Rats treated with Na2S showed increased portal blood levels of thiosulfate and sulfane sulfur, products of H2S oxidation. The intracolonic administration of vehicle did not affect hemodynamic parameters. In controls intracolonic H2S increased PBP but decreased PBF and ABP. In contrast, intracolonic indole increased both BPB and PBF, whereas did not affect significantly ABP. In comparison to controls, CRH showed significantly greater hemodynamic responses to H2S but not to indole. Cirrhotic livers had a significantly higher concentration of H2S but lower expression of rhodanese, an enzyme converting H2S to sulfate.Colon‐administered indole and H2S increase portal blood pressure via distinct hemodynamic mechanisms. Indole increases, whereas H2S decreases portal blood flow. Indole and H2S signaling in the gut‐liver axis may be involved in the control of portal blood pressure and in the etiology of portal hypertension. Further studies on the effects of gut bacterial metabolites on portal circulation are needed.Support or Funding InformationThis work was supported by the National Science Centre, Poland grant no. UMO‐2016/22/E/NZ5/00647This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Chloride ion penetration resistance of concrete containing fly ash and silica fume against combined freezing-thawing and chloride attack

Chloride ion penetration resistance (CPR) of concrete containing fly ash (FA)/silica fume (SF) against combined freezing-thawing and chloride attack was studied. The total charge passed, immersed in tap water and sodium chloride solution, subjected to 50 freezing-thawing cycles was evaluated. It was found that immersed in tap water, SF had more evident improvement on concrete’s resistance to combined effects than FA. Sodium chloride solution immersion for 41d prior to test was more aggressive than tap water. After 50 freezing-thawing cycles, CPR of concrete with FA increased, while that with SF decreased. Interaction between freezing-thawing and chloride attack accelerated concrete deterioration.

Impact of Low and Moderate Salinity Water on Plant Performance of Leafy Vegetables in a Recirculating NFT System

Two greenhouse experiments were conducted to examine the growth and mineral nutrition of four leafy vegetables in a nutrient film technique (NFT) system with water with low to moderate salinity. In Expt. 1, a nutrient solution was prepared using reverse osmosis (RO) water and treatments consisted of supplementing with RO water, tap water, or nutrient solution. In Expt. 2, nutrient solution was prepared using three different water sources (treatments), namely, RO water, tap water, or tap water, plus sodium chloride (NaCl), and supplementing solution was prepared using the same three water sources at one third strength. For both of the experiments, seeds of pac choi ‘Tokyo Bekana’, ‘Mei Qing Choi’, and ‘Rosie’ (Brassica rapa var. chinensis) and leaf lettuce ‘Tropicana’ (Lactuca sativa) were sown and were grown in a growth chamber. Two weeks after sowing, seedlings were transplanted to the NFT systems. Expt. 1 was conducted from 19 April to 19 May 2016 and Expt. 2 from 6 September to 12 October 2016. In Expt. 1, nitrate (NO3−) and phosphorus (P) levels in the tanks decreased, and potassium (K+) levels reached almost zero at the end of the experiment when supplemented with RO or tap water. However, calcium (Ca2+), magnesium (Mg2+), and sulfate (SO42−) either did not decrease or increased over time. Supplementing water type did not affect the growth of leaf lettuce and ‘Mei Qing Choi’ pac choi; however, fresh weight of ‘Rosie’ pac choi and both fresh and dry weight of ‘Tokyo Bekana’ pac choi were reduced when supplemented with RO water. Leaf sap NO3− was reduced in ‘Tokyo Bekana’ pac choi, but not in other varieties, when supplemented with RO or tap water. Leaf sap K+ decreased in ‘Tokyo Bekana’, but not in other varieties. The supplementing water type did not impact leaf sap Ca2+, regardless of vegetable varieties. In Expt. 2, NO3− in all of the treatments, P in RO water, and K+ in RO or tap water decreased in the last week of the experiment. Other macronutrients did not change substantially over time. The addition of NaCl significantly reduced the growth of all the vegetables. ‘Tropicana’ leaf lettuce was the least tolerant to NaCl, followed by ‘Rosie’ pac choi. Water source did not affect leaf Ca2+, K+, P, SO42−, and Mg2+ except for ‘Tokyo Bekana’ where NaCl addition decreased Ca2+ and Mg2+. Our results indicated that the tested leafy vegetables differed in response to various types of water used as supplementing or as source water. N, P, and especially K, should be supplemented in the late stage of the experiment, while replacing the whole tank nutrient solution is only necessary when Na+ and/Cl− build up to harmful levels.

Wire-Mesh 16 × 16 Capacitance Sensor for Analysis of Capacitance Distribution on Cylindrical Pipe

The wire-mesh sensor is an intrusive sensor device that uses for generating 2-dimensional (2D) images of fluid flow. Sensors made of 2 layers copper wires, transmitter, and receiver, that perpendicular each other. The wire-mesh sensor will directly to measure the value of inductance or capacitance at the crossing wire. There are 208 data measurements in 16 × 16 cylindrical wire-mesh sensors. All data measurement then processed by Python software to obtain a 2D image of the capacitance distribution. Experiment results show the inhomogeneous distribution of capacitance that occurs in the wire-mesh sensor. Three types of liquids, distilled water, tap water and salt solution, showed circular pattern of capacitance distribution, with the highest capacitance value being in the central area of the image, while at edge area has a lower capacitance value than the central area

Use of Silica Fume and GGBS to Improve Frost Resistance of ECC with High‐Volume Fly Ash

Fly ash (FA) has been an important ingredient for engineered cementitious composite (ECC) with excellent tensile strain capacity and multiple cracking. Unfortunately, the frost resistance of ECC with high‐volume FA has always been a problem. This paper discusses the influence of silica fume (SF) and ground‐granulated blast‐furnace slag (GGBS) on the frost resistance of ECC with high volume of FA. Four ECC mixtures, ECC (50% FA), ECC (70% FA), ECC (30% FA + 40% SL), and ECC (65% FA + 5% SF), are evaluated by freezing‐thawing cycles up to 200 cycles in tap water and sodium chloride solution. The result shows the relative dynamic elastic modulus and mass loss of ECC in sodium chloride solution by freeze‐thaw cycles are larger than those in tap water by freeze‐thaw cycles. Moreover, the relative dynamic elastic modulus and mass loss of ECC by freeze‐thaw cycles increase with FA content increasing. However, the ECC (30% FA + 40% SL) shows a lower relative dynamic elastic modulus and mass loss, but its deflection upon four‐point bending test is relatively smaller before and after freeze‐thaw cycles. By contrast, the ECC (65% FA + 5% SF) exhibits a significant deflection increase with higher first cracking load, and the toughness increases sharply after freeze‐thaw cycles, meaning ECC has good toughness property.

Long-Term Oral Administration of Theaphenon-E Improves Cardiomyocyte Mechanics and Calcium Dynamics by Affecting Phospholamban Phosphorylation and ATP Production

Background/Aims: Dietary polyphenols from green tea have been shown to possess cardio-protective activities in different experimental models of heart diseases and age-related ventricular dysfunction. The present study was aimed at evaluating whether long term in vivo administration of green tea extracts (GTE), can exert positive effects on the normal heart, with focus on the underlying mechanisms. Methods: The study population consisted of 20 male adult Wistar rats. Ten animals were given 40 mL/day tap water solution of GTE (concentration 0.3%) for 4 weeks (GTE group). The same volume of water was administered to the 10 remaining control rats (CTRL). Then, in vivo and ex vivo measurements of cardiac function were performed in the same animal, at the organ (hemodynamics) and cellular (cardiomyocyte mechanical properties and intracellular calcium dynamics) levels. On cardiomyocytes and myocardial tissue samples collected from the same in vivo studied animals, we evaluated: (1) the intracellular content of ATP, (2) the endogenous mitochondrial respiration, (3) the expression levels of the Sarcoplasmic Reticulum Ca²⁺-dependent ATPase 2a (SERCA2), the Phospholamban (PLB) and the phosphorylated form of PLB, the L-type Ca²⁺ channel, the Na⁺-Ca²⁺ exchanger, and the ryanodine receptor 2. Results: GTE cardiomyocytes exhibited a hyperdynamic contractility compared with CTRL (the rate of shortening and re-lengthening, the fraction of shortening, the amplitude of calcium transient, and the rate of cytosolic calcium removal were significantly increased). A faster isovolumic relaxation was also observed at the organ level. Consistent with functional data, we measured a significant increase in the intracellular ATP content supported by enhanced endogenous mitochondrial respiration in GTE cardiomyocytes, as well as higher values of the ratios phosphorylated-PLB/PLB and SERCA2/PLB. Conclusions: Long-term in vivo administration of GTE improves cell mechanical properties and intracellular calcium dynamics in normal cardiomyocytes, by increasing energy availability and removing the inhibitory effect of PLB on SERCA2.

AGE FEATURES OF THE MORPHOLOGY OF TONGUE GLANDS

Tongue provides a person with many functions, participates in speech, taste receptions (the peripheral part of the taste analyzer), the initial stages of digestion and moisturizes the mucous membrane of the oral cavity. The lingual glands, along with others, produce saliva, but in a smalt amount, in comparison with the large salivary glands. The purpose of the study is to study the number of lingual glands and their morphological features in people of different ages and sex under normal conditions. Macroscopic, histological methods and parametric statistics methods have been used to study the glands of the tongue, obtained from the corpses of 149 men and 150 women who died from the period of the newborn to 96 years, for reasons of asphyxia incompatible with the life of injuries. On total preparations of the tongue, the glands were electrically stained in a 0.5% solution of acetic acid with 0,05% methylene blue solution in tap water. We studied the total number, length and width of the initial sections of the glands of different parts of the tongue - at its anterior, middle and posterior third, and also in the organ as a whole. For histological examination, the gland was further studied on preparations obtained after evisceration (139 cases). As a result of the study, it was revealed that the size and quantity of lingual glands in postnatal ontogenesis vary in the direction from the tip to the root of the tongue (increase from front to back). In this case, the glands of the root of the tongue produced a saliva of a mucous nature. Given that ensuring the oral phase of swallowing requires the presence of a mucous secretion in the oral cavity, the morphological changes of lingual glands in the thickness of the tongue revealed by us are absolutely physiologically necessary. Changing the size and number of glands throughout the mucous membranes of internal organs is recognized as one of the patterns of their structural organization.

Degradation of drag reducing polymers in aqueous solutions

The performance of drag reducing polymers in turbulent flow is restricted by their mechanical degradation. This study examines how the working fluid can affect the degradation behavior of diluted drag reducing polymeric solutions. Solutions having different proportions of tap water and de-ionized water served as the working fluids. Three commercially available water soluble polymeric agents, namely, an anionic copolymer of polyacrylamide, xanthan gum, and polyethylene oxide, were then added to these solutions. All experiments had identical flow rates corresponding to turbulent conditions in a laboratory scale pipe line. Variation of pressure drop in the pipe line was then measured for 2 hours. It was found that polymer degradation is accelerated in tap water solutions compared to that in de-ionized water solutions. However, this is dependent on the specification of the polymer used, namely, the molecular weight of the polymer and the rigidity of its molecular backbone. Furthermore, a new mathematical relation has been developed to investigate degradation of the polymers over time.

Crumpled graphene oxide decorated SnO2 nanocolumns for the electrochemical detection of free chlorine

A crumpled graphene oxide–SnO2 nanocolumn (CGO–SnO2) composite electrode was fabricated using aerosol-based techniques. First, SnO2 nanocolumn thin films were fabricated using an aerosol chemical vapor deposition (ACVD) technique. The surface of the nanocolumn was then decorated with CGO by electrospray deposition. The CGO–SnO2 electrode was utilized for the electrochemical detection and determination of the free chlorine concentration in aqueous solutions using linear sweep voltammetry (LSV) and amperometric i–t curve techniques. The CGO–SnO2 electrodes worked through the direct electrochemical reduction of hypochlorite ions (ClO−) on the surface of the electrode, which was used to determine the free chlorine concentration. The electrodes operate over a wide linear range of 0.1–10.08 ppm, with a sensitivity of 2.69 µA µM−1 cm−2. Further, selectivity studies showed that these electrodes easily conquer the electrochemical signals of other common ions in drinking water distribution systems, and only shows the electrochemical reduction signals of free chlorine. Finally, the CGO–SnO2 electrodes were successfully employed for the detection of free chlorine in tap water solutions (St. Louis, MO 63130, USA) with a sensitivity of 5.86 µA µM−1 cm−2. Overall, the sensor fabricated using simple and scalable aerosol-based techniques showed a comparable performance to previous studies on amperometric chlorine sensing using carbon-based electrodes.

Preliminary evaluation of new green antiscalants for reverse osmosis water desalination

Abstract Supplying fresh water has become an important environmental and economic issue. Desalination with reverse osmosis (RO) represents an effective solution to meet the challenges of cleaning brackish water and seawater for drinking and industrial purposes. The principal problem of RO plant operation is the precipitation of low soluble salts (scaling). There are some well-known techniques to reduce scaling; one of the most widespread is antiscalant dosing. In this study, 11 samples of new prototype chemicals based on co-polymers of acrylic and methacrylic acids, polyaspartic acid, maleic anhydride and different cross-linking agents is tested. A wide range of commercial phosphorus-based and green inhibitors were used as reference antiscalants. The testing procedure included circulation experiments on a RO laboratory unit with continuous concentration of feed water – tap water and model solution with elevated hardness. The amount of calcium carbonate accumulated in the membrane module was determined and the inhibitor efficiency was calculated. The best results were obtained for scale inhibitors based on polyaspartic and (poly)acrylic acids. The most promising was the reagent based on a mixture of polyaspartate and nitrilotrimethylphosphonic acid.

Highly sensitive and selective assay method for iodide ion determination based on gold nanoparticles conjugated with glycol chitosan

ABSTRACTA sensitive colorimetric method for the determination of iodide ions was developed using gold nanoparticles (AuNPs) functionalised with glycol chitosan (GCS). The iodide ions were at the centre of the O–I––O coordination structure, formed with the GCS-AuNPs, reducing their interparticle distance and inducing aggregation. Time-of-flight secondary ion mass spectrometry analyses showed that the bound iodide ions were coordinated to the oxygen atoms of the ethylene glycol in GCS, with this aggregation leading to a considerable variation in colour from light red to dark violet. Using this GCS-AuNP probe, the iodide ion concentration in environmental, biological and pharmaceutical samples could be determined by both the naked eye and UV-Vis spectroscopy. Additionally, the sensitivity of the detection was found to be markedly enhanced at pH 6, where a more pronounced colour change was observed. The absorption ratio A700/A521 of the functionalised AuNP solution correlated linearly with the iodide ion concentration within the range 0.0–10.0 mg/L, and the limits of detection in tap water, pond water, and bovine serum solution were 3.5, 3.6, and 3.4 μg/L, respectively. The present assay method can thus be utilised to rapidly measure the concentration of iodide ions in aqueous samples.

Inhibition of larval growth of Dαcus oleαe by topical application of streptomycin to olives

Olives of four varieties were oviposited by females of Dacus oleae (Gmelin) (Diptera: Tephritidae). One to four hours or one day later, a 5 μl drop of streptomycin sulphate solution in tap water was applied to the oviposition hole. If applied 1-4 hours after oviposition, concentrations of 0.1, 0.3, or 1% were equally effective, inhibiting larval growth in over 85% of the olive fruits. If applied one day later, the 0.1% concentration was less effective, while the 0.3 and 1% ones retained their high effectiveness. With 2 μl drops, inhibition was not significantly lower than with 5 μl drops. The addition of 0.05% or 0.5% Agral 90 a spreader-wetter, had an activating effect, causing a substantial and significant increase of the percent inhibition.