Distilled-deionized Water Research Articles

Effectiveness of New Isomalt-Containing Toothpaste Formulations in Preventing Dental Caries: A Microbial Study.

Human dental enamel slabs were allocated to six groups (30/group) at random: De-ionized distilled water (DDW), and toothpaste containing 10% Isomalt, 1100 ppm fluoride, 0.05% cetylpyridinium chloride [CPC] (ICT); 10% Isomalt, 1100 ppm fluoride (IT); 10% Isomalt, 1100 ppm fluoride, 1.5% Sodium lauryl sulfate [SLS] (IST); 1100 ppm fluoride only (FT); 1100 ppm fluoride with SLS (FST). The enamel slabs were exposed to caries development via plaque growth in a Microbial Caries Model for 7 days. Toothpastes were applied as slurries (one toothpaste-three DDW) for 2 min twice daily. Demineralization was measured as the change in surface microhardness (ΔSMH) and amount of mineral lost (∆Z), and these metrics were assessed using Transverse Microradiography. Intra-group (SMH) and intergroup (%∆SMH and ∆Z) comparisons were paired t-test and Tukey's test (α = 0.05), respectively. With SMH, demineralization was found to be significant (p < 0.001) in all groups compared to sound enamel baseline, except ICT group. With %ΔSMH, all other groups had significantly (p < 0.001) less demineralization compared to DDW. Significantly (p < 0.001) greater demineralization was observed in IT, FT and FST compared to ICT, and no significant difference was observed between IST and ICT or FT. With ∆Z, relative to the DDW group, the inhibition of demineralization was significant (p < 0.0001) in all groups at varying percentages. Toothpaste containing 10% Isomalt, 1100 ppm fluoride, and 0.05% CPC demonstrated greater efficacy in inhibiting caries development amid dental plaque compared to toothpaste containing only 1100 ppm fluoride.

Crumpled graphene fully decorated with nickel-based nanoparticles applied in glyphosate detection.

Glyphosate (Glyp), a widely used herbicide, has raised significant concerns regarding its toxicological effects and potential risks to human health, particularly concerning water pollution. Hence, there is a critical need to monitor glyphosate levels in water bodies. This study introduces a novel approach for electrochemically detecting glyphosate in aqueous environments using crumpled graphene decorated with nickel-based nanoparticles (Ni:CG) synthesized in a single step. Cyclic voltammetry and chronoamperometry techniques were employed for detection. The cyclic voltammetry analysis revealed an impressive linear range with detection and quantification limits of 2.0 × 10-9 M and 6.0 × 10-9 M, respectively. Additionally, the method demonstrated excellent accuracy and precision at low concentrations, as evidenced by successful glyphosate recovery from distilled-deionized water and spike-and-recovery tests, at a significant level of 99.9%. Furthermore, interference tests conducted via chronoamperometry on the presence of Cu2+, Co2+, and Fe3+ cations showcased the superior performance of the Ni:CG electrochemical sensor. The synthesis of crumpled graphene-/nickel-based composites offers a promising avenue for the future of on-site glyphosate detection, presenting a robust and efficient solution to environmental challenges.

In Vitro Release Kinetics of Nystatin and Tannic Acid in Artificial Body Fluids from Hydrogels Prepared by Using Polyvinylpyrrolidone Crosslinked with Tannic Acid

AbstractBiocompatible hydrogels of polyvinylpyrrolidone (PVP) with tannic acid (TA) in the weight ratios of 1 : 0.70 (70 %)–1 : 0.60 (60 %) were prepared and loaded with the antifungal drug, nystatin (NYS). The hydrogel is expected to exhibit a two‐fold (anti‐bacterial and anti‐fungal) characteristics. Infrared spectroscopy (IR), viscometry and differential scanning calorimetry (DSC) were used to investigate interactions between PVP and TA. In vitro release kinetics of NYS in simulated body fluid (SBF) and sweat (SS) were studied using ultra‐violet spectroscopy (UV) and high‐performance liquid chromatography (HPLC). An increase in the glass transition temperature (Tg) of PVP accompanied with changes observed in the OH stretching, C=O and the C−O−C regions in the IR spectrum in dried PVP/TA hydrogel suggested physical crosslinking. The swelling of the hydrogels in distilled deionized water (DDW), SBF and SS decreased with increasing TA concentration and showed pH sensitivity. TA release followed the Korsmeyer‐Peppas kinetic model regardless of swelling media while NYS followed the Korsmeyer‐Peppas and Hixson‐Crowell cube root law in SS and SBF respectively. TA was active against Escherichia coli and Staphylococcus aureus while NYS against Candida albicans. A topical patch was prepared by adhering the drug loaded PVP/TA hydrogel onto silicone strips.

Ultrasensitive electrochemical detection of glyphosate using crumpled graphene/copper oxide nanocomposite

Glyphosate (Glyp) is an herbicide mainly employed worldwide. This has generated significant concern regarding the toxicological impacts and risks to humans, primarily water contamination. Therefore, the monitoring of glyphosate in water is demanding. Herein, we synthesized in one step crumpled graphene fully decorated with copper oxide nanoparticles (CG/CuO) for ultrasensitive electrochemical detections of glyphosate in water. The linear range was obtained by differential pulse voltammetry and performed in picomolar (5.00 – 25.00 ×10-12 M), demonstrating exceptional linearity, with limits of detection - LD (0.30 ×10-12 M) and quantification - LQ (0.90 ×10-12 M). Furthermore, the successful recovery analysis of enriched glyphosate from the distilled-deionized, river, groundwater, and untreated tap water, with great accuracy and precision achieved at low concentrations, demonstrated the advantages of our CG/CuO electrochemical sensor. This one-step strategy to prepare crumpled graphene-based copper composites is a promising method for future in-loco detection of Glyp.

Influence of an external magnetic field on laser-induced plasma and cavitation bubbles in submerged targets

A pulsed Nd:YAG laser is tightly focussed on a metal target immersed in distilled de-ionized water. The resultant laser-induced plasma and subsequent cavitation bubble behavior are studied under the influence of an external magnetic field that is varied from 700 to 1000 Gauss. The study is conducted using a beam deflection probe arrangement. In addition, laser-induced breakdown spectroscopy is also employed to study the plasma spectrum. Furthermore, three different magnetic materials are employed for this investigation: ferromagnetic nickel, paramagnetic gadolinium, and diamagnetic copper. The studies revealed that cavitation bubble radii and collapse durations increased considerably as the magnitude of the external magnetic field was increased. This effect was prominent in the case of nickel and less so in the case of gadolinium and copper. For nickel, collapse times increase when the magnetic field was applied, whereas for gadolinium and copper, significant changes were not observed. The differences observed in collapse times showed that magnetic properties of the targets played a vital role in this phenomenon. The process of pulsed laser ablation in liquid also led to the respective generation of metallic nanoparticles from individual materials. Characterization of the generated nanoparticles revealed size reduction when synthesized under the influence of an external magnetic field. These characterizations were performed using transmission electron microscopy and UV-Vis spectroscopy.

An empirical experimental investigation on the effect of an external electric field on the behaviour of laser-induced cavitation bubbles.

This study is an attempt to empirically investigate the behaviour of laser-induced cavitation bubbles under the influence of an external electric field. As such two targets (copper and iridium) were subjected to a high-power Nd:YAG laser beam while being submerged in a liquid. Three different liquids were chosen for this purpose viz. acetone, ethanol, and distilled de-ionized water. The choice of the liquids was made with the underlying assumption that the conductivity of the liquids would play a significant role in responding to the applied external electric field and thus dictate the behaviour of the cavitation bubbles. A probe-beam method known as a beam deflection setup was employed for this experiment and the results were analyzed using the Rayleigh-Plesset model. The results revealed that the maximum radii of the cavitation bubbles increased in response to an increasing electric field. This effect was more pronounced in the presence of acetone medium and decreased successively while using ethanol and water media owing to their varying magnitudes of electrical conductivity. The bubble collapse speeds and their energies were also measured and similar trends were observed in both cases. The results from cavitation bubble dynamics were then applied to a Gilmore model and the sizes of the NPs synthesized using laser ablation with and without an external electric field were calculated using classical nucleation theory.

Comparative study of pulsed laser-induced breakdown at a metal-liquid interface at two liquid temperatures using a beam-deflection probe

A pulsed Nd: YAG laser is tightly focussed on a nickel wire-shaped target immersed in a glass cell filled with distilled de-ionized water. The resultant shock wave and cavitation bubble dynamics, occurring because of the laser-induced plasma expansion, are recorded using a pump-probe set-up. The shock wave and cavitation bubble dynamics are recorded at two temperatures of the liquid. It was observed that a higher liquid temperature results in a higher velocity of shock wave propagation, which consequently led to a higher pressure exerted by the shock wave. The experimentally determined shock wave velocities were 1.8 and 1.9 km/s for cold and hot water, respectively. Consequently, the pressure values amounted to 0.23 and 0.27 GPa, respectively. Cavitation bubble radii determined experimentally were 975 μm and 742 μm, for cold and hot water, respectively. Also, a higher liquid temperature led to a higher order of cavitation bubble formation.

EVALUATION OF THE BIOLOGICAL EFFECT SYNTHESIZED IRON OXIDE NANOPARTICLES ON ENTEROCOCCUS FAECALIS

This study was aimed to demonstrate the biosynthesis procedure of iron oxide nanoparticles (Fe2O3 NPs) by using prodigiosin pigment produced from environmental isolate Serratia marcescens as a reducing and stabilizing agent. Additionally, the synthesis conditions were precisely taken into consideration as a pH of 7 and a temperature of 50°C alongside a concentration of prodigiosin of 12 mg/ml with a precursor of ferric sulfate of 5 mg/50ml in deionized distilled water (DDW). Biosynthesized Fe2O3 nanoparticles have presented many applications such as catalysis, biosensing, anticancer, and biomedical, etc. The study of optimum condition for the synthesis of Fe2O3 was characterized by different techniques, such as (XRD, UV-VIS, AFM, FTIR and FE-SEM). The wavelength of biosynthesis of Fe2O3 by using UV-VIS is (284 nm), Image FE-SEM displays Spherical Fe2O3 NPs in nano-cluster form and the average volume is (35.01) nm). And the effect of Fe2O3 NPs on bacteria Enterococcus faecalis on an inhibition zone 31 mm.

Formulation Design and Ex Vivo Evaluation of Carbopol -Incorporated Mucoadhesive Thermoreversible gels of Sucralfate for Rectal Drug Delivery

Aim: The present research is focused on preparation of Thermoreversible gels and screening ex vivo anti-inflammatory activity using croton oil induced hemorrhoid model.&#x0D; Study Design: The animals were divided into four groups, n=8. After overnight fasting, hemorrhoids were induced by inserting sterile cotton swabs soaked in croton oil preparation into the anus of all group animals except normal control group.&#x0D; Place and Duration of Study: Depart of Pharmacology, Sree Vidyanikethan College of Pharmacy, Tirupati. between October 2021 to December 2021&#x0D; Methodology: Experimental runs for optimization of formulation with the help of 23 factorial designs were designed [1]. Design of Expert program 6.0.6 (Stat-Ease Inc. Minneapolis, MN) was used to create formulations. Formulations were optimized using full factorial de­sign. In situ rectal gel was prepared by the cold meth­od [2]. As shown in Table 1, P188 was dissolved in DDW (de-ionized distilled water) including drug (1% w/v) at room temperature, and it was stored at 4°C for complete solubilization of P188. Carbopol solubilized in DDW, HPMC K4M and other mu­coadhesive polymers were then slowly added to the prepared solution with continuous agitation at 4°C, and were kept for 24 h before their use. The composi­tion of developed gel formulations is summarized in Table 1.&#x0D; Results: Results In the first set of experiment, the application of croton oil to recto anal portion of rats induced significant increase in the Recto anal coefficient and serum level of pro inflammatory cytokines such as IL-6, and TNF \(-a\) it also showed a significant increase in recto anal portion compared to normal control animals. However, the treatment with Sucralfate containing Thermoreversible gels has maintained the RAC and Interleukin -6 levels near to normal control group. These findings were further supported by histopathological examination wherein the animals treated with optimized formulation showed significant reversal in the severity of inflammation, vasodilatation in the recto anal portion, and presence of inflammatory cells.&#x0D; Conclusion: The findings of the present study suggest that the improved experimental model described in the present work has advantages and the model has a provision for quantifying the inflammatory exudates in the induced experimental hemorrhoids. Also, it was found that, the optimized formulation ameliorated the croton oil-induced hemorrhoids in rats.

EVALUATION OF THE BIOLOGICAL EFFECT SYNTHESIZED ZINC OXIDE NANOPARTICLES ON PSEUDOMONAS AERUGINOSA

This study was aimed to demonstrate the biosynthesis procedure of Zinc oxide nanoparticles (ZnO NPs) using Prodigiosin pigment which in turn produced from particular environmental bacteria isolates Serratiamarcescensas a stabilizing and reducing agent. Additionally, the synthesis conditions were precisely taken into consideration as a pH of 7 and a temperature of 50°C alongside a concentration of prodigiosin of 12 mg/ml with 5mg precursor of zinc acetate in deionized distilled water (DDW) 50ml. Biosynthesized ZnO nanoparticles have presented many applications such as catalysis, biosensing, anticancer, and biomedical, etc. The optimum condition for ZnO biosynthesis was characterized through several techniques such as UV-Vis, AFM, XRD, FT-IR, and FE-SEM. In particular, a cut-off phenomenon of the biological synthesized ZnO was found at around 280 nmusing UV-Vis, while spherical shape particles were noticed using FE-SEM techniques. Also, the AFM analysis revealed that ZnO NPs an average diameter size of 45.02 nm.And the effect of ZnO NPs on bacteriaPseudomonas aeruginosaon an inhibition zone 29mm.

Control of Anthracnose Caused by Colletotrichum Gloeosporioides in Calcium Nitrate Foliar-Sprayed Dioscorea Rotundata Variety Amula

Calcium nitrate foliar spray for the control of anthracnose disease caused by Colletotrichum gloeosporioides Penz, in the Nigerian white guinea yam Dioscorea rotundata variety Amula was investigated in this study. The field experiment was a randomized complete block design (RCBD) with three replicates. Seed yams of&nbsp; &nbsp;0.5kg average weight were planted at the onset of rains in 2018. At 12 weeks after planting (12 WAP), calcium nitrate (analar grade) in distilled de-ionized water and without surfactant, at the rate 0mgl-1 (control), 5mgl-1 and 10mgl-1 was sprayed, randomized per replicate. Anthracnose incidence and severity were assessed at 20WAP and 24 WAP. At 24 WAP also leaves were sampled according to treatments, processed and analysed for minerals and total phenolic compounds (TPC) according to standard methods. Minerals analysed were Calcium (Ca), Magnesium (Mg), Nitrogen (N), Phosphorus (P), Potassium (K) and Sulphur (S). Disease incidence at 20WAP was 13.89% in the 10mgl-1 treatment but was 0% in the 5mgl-1­ treatment and also in the control. Disease severity score (DSS) was similar across treatments at 20WAP and was resistant score of 1. At 24WAP disease incidence in the 10 mgl-1­­ treatment had decreased to 5.56% and was also 5.56% in the 5 mgl-1 treatment, significantly lower than the control which had risen to 17.77%. With the increase in incidence in control plants to 17.77%, severity increased also to 1.10 and was 1.00 in each of the two calcium nitrate treatments, thus DSS at 24WAP was 1, resistant. Leaf total phenolic compounds (TPC) at 24WAP was 3.81mg GAE/gdm in the 10 mgl-1 treatment, significantly higher than the 5mgl-1 TPC which was 3.11mg GAE/g dm and the TPC of the control which was 2.82mg GAE/gdm. Antifungal properties of phenolic compounds in the leaves of cultivar Plimbite of Dioscorea alata is reported to be responsible for its resistance to anthracnose. Increase in leaf TPC content in treatment 10mgl-1 in this study may be responsible for the decrease in anthracnose incidence from 13.89% to 5.56% in the treatment over the control at 24 WAP. 10 mgl-1 Calcium nitrate foliar spray is suitable in white guinea yam variety Amula for increase in total phenolic compound content in the leaves. Leaf sulphur content was similar across the three treatments. Calcium, Magnesium, Potassium and Phosphorus were significantly higher in the two calcium nitrate treatments than the control. Calcium role in membrane form and function and in the enhancement of cell wall structural integrity has been reported and its increase with the Ca(NO3)2 foliar spray would reduce necrosis by the pathogen and along with increased TPC enhance resistance to anthracnose in the variety. N was higher in the leaves of the 10mgl-1 treatment plants than the control. Disease susceptibility is reported to depend on nitrogen supply and N-supply effect on susceptibility is reported to be pathogen-specific because N increase decreases severity to facultative parasites. Also N increase in reported to support metabolic activities of host cells and to delay senescence which will favour obligate parasites but not facultative parasites such as the anthracnose pathogen Colletotrichum gloeosporioides. This is so because facultative parasites are semi-saprophytes nutritionally and depend partially on senescing cells and alternatively release toxins in order to damage/kill host plant cells. Thus increase in Calcium, Nitrogen and TPC by Calcium Nitrate foliar spray in this study is favourable for resistance to anthracnose in variety Amula and other white guinea yam varieties and a second foliar spray of the two concentrations used in this study is suggested in a future trial at 30 WAP for possible reduction of anthracnose incidence to 0%. No surfactant was used in this study in the nutrient solution. Polysorbate 20 at 0.01% had been used as surfactant in calcium nitrate foliar spray for the control of anthracnose disease in Dioscorea species but this surfactant concentration has not been established as optimum. Surfactants are reported to stimulate nutrient penetration or&nbsp; absorption at low concentrations, but affect native structure of membrane-bound proteins/stability of lipid layers at high concentrations, leading to loss of membrane integrity, implying that non-optimal surfactant concentrations in the nutrient spray would cause additional necrosis along with that caused by the anthracnose pathogen. This study shows that despite the non-addition of surfactant (polysorbate 20), the extent of absorption of calcium nitrate was enough to increase the TPC, Calcium and Nitrogen responsible for anthracnose control in the sprayed plants.

Molecular Structural Evolution of Near-Infrared Cationic Aggregation-Induced Emission Luminogens: Preclinical Antimicrobial Pathogens Activities and Tissues Regeneration

Molecular Structural Evolution of Near-Infrared Cationic Aggregation-Induced Emission Luminogens: Preclinical Antimicrobial Pathogens Activities and Tissues Regeneration

Study on preparation, compression strength and theophylline/diclofenac sodium release ability of NIPAAm/DMAPMAAm hydrogels

The present study was undertaken to investigate the effect of the composition of the polymerization medium and the type of drug/drug loading process on the mechanical strengths and release profiles of poly(N-isopropylacrylamide-co-N-[3-(dimethylamino)propyl] methacrylamide) P(NIPAAm-co-DMAPMAAm) hydrogels. In line with this goal firstly, the temperature- and pH-responsive hydrogels of NIPAAm and DMAPMAAm were synthesized in three different media at 60 °C: pH 7.4 phosphate-buffered saline (PBS), pH 7.4 phosphate buffer without NaCl/KCl (PB), and distilled-deionized water (pH ≈ 5.5 DDW). The result is that the presence of anionic species such as phosphate (HPO4 2-/H2PO4 -) and chloride (Cl-) ions in the solution affects on their basic network properties such as volumetric swelling ratio and compression modulus. To evaluate their intermolecular interactions with protonated DMAPMAAm units and drug molecules, depending on composition, type of loading process and drug structure, each of the hydrogels was loaded with diclofenac sodium (DFNa) and theophylline (Thp) by using both diffusion and in situ loading methods. DFNa and Thp release profiles in pH 7.4 PBS at 37 °C were analysed by using zero-order, first-order, Higuchi, Korsmeyer-Peppas, and Peppas-Sahlin models. It has been observed that for the first 60% of DFNa and Thp releases from P(NIPAAm-co-DMAPMAAm) hydrogels synthesized in PB at 60 °C, the contribution of the chain relaxation for the copolymer hydrogels loaded during gelation process was higher than the ones loaded by diffusion process.

Proteins as targets for high dilutions of drugs: Interaction between ?-amylase and mercuric chloride.

Background: High dilutions of drugs, used in homeopathy, are usually applied by oral route or foliar spray. These dilutions first come in contact with membrane or circulating proteins. Ultra low doses of mercuric chloride, called potencies, promote activity of diastase or ?-amylase in terms of breakdown of starch, a polysaccharide into a disaccharide maltose in a cell-free medium in test tubes. Merc cor or HgCl2 in high doses inhibits the enzyme activity. &#x0D; Aims: To see (i) whether the high and ultra low dose effects of HgCl2 involve different binding sites of the enzyme and (ii) to find an explanation for the low dose effect of HgCl2 in spite of absence of its original molecules. &#x0D; Methodology: Merc cor mother tincture (147 mM HgCl2) in distilled water was used undiluted in this experiment. Merc cor 200c and 1000c were prepared from the mother tincture (MT) by successive dilution with water 1:100 followed by succussion in 200 and 1000 steps, respectively, and finally preserved in 90% EtOH. These potencies and blank 90% ethanol, were diluted with deionized, distilled (DD) water 1:1000 to minimize ethanol content in test solutions. Each test solution or control was mixed with the enzyme 1:10 just before experiment. The control consisted of DD water. An isothermal calorimetry (ITC) instrument was used to measure the interaction between soluble starch and ?-amylase mixed with each potency (200c/1000c) of Merc cor, its mother tincture, ethanol and control. ITC is a thermodynamic technique which helps in measuring directly very small amount of heat evolved during chemical reaction. Soluble starch 90 µM was injected into 300 µl of 15µM ?-amylase at 2 µl / injection. Twenty injections, one every 2 min, were given. The enzyme substrate interaction in terms of heat released (exothermic) or absorbed (endothermic) were monitored by the ITC instrument. All ITC measurements were calculated and analyzed statistically by an in-built software Origin 7.&#x0D; Results and discussion: The data are presented in figures. While Merc cor MT shows endothermic reaction, all its potencies, ethanol and water control show exothermic reactions. There is wide variation in enthalpy (?H), entropy (?S), binding constant (K) and Gibbs free energy change (?G) among the treatments with Merc cor MT, potencies, ethanol and also control. The results indicate that Merc cor MT and its potencies act on different binding sites of the enzyme. The variation in thermodynamic parameters suggest difference in binding interaction between the drug solutions and the enzyme. This in turn influences the enzyme substrate interaction as reported in earlier studies. The potencies are virtually water modified by the starting substance HgCl2.&#x0D; Conclusion: The mother tincture and potencies of mercuric chloride produce different effects on the enzyme substrate interaction. Potencies show wide variation in ?H, ?S, K and ?G values. It appears from the results that the drugs used in homeopathy produce dual action on proteins. At high doses they act on a binding site(s) but at ultra low doses they act on a different binding site(s). Proteins in an organism may serve as targets for initiation of action of homeopathic potencies.

Using Proanthocyanidin as a Root Dentin Conditioner for GIC Restorations

Glass ionomer cements (GICs) are considered the material of choice for restoration of root carious lesions (RCLs). When bonding to demineralized dentin, the collapse of dentinal collagen during restorative treatment may pose challenges. Considering its acidic nature and collagen biomodification effects, proanthocyanidin (PAC) could be potentially used as a dentin conditioner to remove the smear layer while simultaneously acting to biomodify the dentinal collagen involved in the bonding interface. In this study, 6.5% w/v PAC was used as a conditioner for sound (SD) and laboratory demineralized (DD) root dentin before bonding to resin-modified GIC (FII), casein phosphopeptide–amorphous calcium phosphate (CPP-ACP)–modified GIC (FVII), or a high-viscosity GIC (FIX). Root dentin conditioned with deionized distilled water (DDW) or polyacrylic acid (PAA) served as controls. Results indicated FII showed higher shear bond strength (SBS) on SD than the other 2 GICs, especially in PAA-conditioned samples; FIX showed significantly higher SBS than FII and FVII on PAA- or PAC-conditioned DD. In each category of GIC, PAA and PAC did not have a significant influence on SBS in most cases compared to DDW except for a significant decrease in PAC-conditioned SD bonded to FII and a significant increase in PAA-conditioned DD bonded to FIX. The bonding interface between GIC and SD was generally more resistant to the acid-base challenge than DD. Although the alterations in failure modes indicated a compromised interfacial interaction between GICs and PAC-treated root dentin, biomodification effects of PAC on dentin were observed from Raman microspectroscopy analysis in terms of the changes in mineral-to-matrix ratio and hydroxyproline-to-proline ratio of dentin adjacent to the bonding interface, especially of DD. Results from this study also indicated the possibility of using in situ characterization such as Raman microspectroscopy as a complementary approach to SBS test to investigate the integrity of the bonding interface.

Development of a Solid - Phase System for the Extraction of Diazinon from Water

A selected sorbent granulated activated charcoal solid - phase extraction was developed and used to extract diazinon from distilled water (TDW), distilled deionized water (DDW) and stream water (DW) was studied in the laboratory. Prior to the extraction, the half-live of the diazinon was determined in buffer solutions of pH 6, 7 and 8. The study showed that the half-lives were found to be 0.074, 0.022 and 0.077 hours respectively. Aqueous solution of diazinon was extracted in triplicate from distilled water, deionized distilled water and stream water using SPE systems. The extracted analyte was analysed by uv-visible spectrophotometer. The mean percentage recovery from distilled water, deionized distilled water and stream water using SPE 88.58%, 78.74% ad was 67.85% respectively while diazinon recovery using Liquid-liquid Extraction techniques gave a mean percent recovery of 96.60%, 93.80% and 75.54% for DW, DDW ad SW respectively. The mean percent analyte loss for SPE systems was 32.79%. The value was approximately twice higher than those obtained from LLE techniques with a value of 14.16%. The mean percentage recovery and analyte loss for SPE and LLE were compared. Similarly, the second order rate constant of diazinon of pH6, 7 and 8 were 2.6 x 10-3, 8.8 x10-3 ad 2.5 x 10-3 M-1S-1respectively. The study suggests that granulated activated charcoal can be used as an sorbent to extract diazinon from water.

Modeling phosphorus adsorption onto polyaluminium chloride water treatment residuals

Abstract Beneficial reuse and appropriate disposal of water treatment residuals (WTRs) are of great concern for sustainable drinking water treatment. Using WTRs to remove phosphorus (P) is widely regarded as a feasible approach. However, the information is still limited on air-dried WTRs containing polyaluminium chloride (PAC) and anionic polyacrylamide (APAM) used to adsorb P. The objectives of this study were to construct artificial neural network (ANN) models for P adsorption onto WTRs from distilled de-ionized (DDI) water solution and stormwater, to investigate the performance of ANN in predicting phosphorous adsorption, and to model isotherm adsorption, kinetics, and thermodynamics by using the index of model performance. Batch experiments were performed with different WTRs dosage, pH, initial P concentration, temperature, and time. ANN models accurately predicted the P concentration at equilibrium. Non-linearized Langmuir model fitted the isotherm data best. Pseudo second-order kinetic model provided a better fit to experimental data. The adsorption process may be at least simultaneously controlled by surface adsorption and intraparticle diffusion. The P adsorption is a homogenous monolayer adsorption that is spontaneous, endothermic, and entropy production process. WTRs were found to be favorable and effective in removing P, but the P removals had significant differences in both solutions.

Prolonged water immersion alters resistance to sliding of aesthetic orthodontic coated wires.

The objective of this study was to compare the resistance to sliding of aesthetic orthodontic coated wires after prolonged water immersion for up to 4weeks. An in vitro study of commercially available orthodontic appliances. Aesthetic coated stainless-steel wires (Parylene-coated, epoxy-coated and Teflon-coated) (0.019"×0.025") and an uncoated control were immersed in distilled-deionized water for zero, two or four weeks at 37°C and then were subjected to resistance-to-sliding tests through a three-bracket system of sapphire ceramic brackets (0.022"×0.028" slot) and clear-coloured elastic ligatures at a contact angle of 0° or 3°. Maximal and average resistance to sliding was analysed by a three-way analysis of variance, two general linear models and a post hoc Tukey's honest significant difference test. Water immersion time, contact angle, wire group and their interactions had statistically significant effects on the resistance to sliding of tested orthodontic wires. Various coated wires had distinct timely changes in the maximal and average resistance to sliding after water immersion for 2 to 4weeks. When compared to the uncoated control in most of the experimental conditions, epoxy-coated wires had lower or non-significant differences in resistance to sliding, while Parylene-coated wire had higher resistances. Prolonged water immersion for weeks alters the resistance to sliding of aesthetic orthodontic wires coated with Parylene, epoxy or Teflon. Based on their resistance to sliding, different designs in orthodontic biomechanics should be considered for the different aesthetic orthodontic coated wires.

Enamel Erosion: A Possible Preventive Approach by Casein Phosphopeptide Amorphous Calcium Phosphate-An In Vitro Study.

ContextSeveral efforts were made in order to alter the compositions of acidic food items concerning their properties to be able to reduce their erosivity potential. The addition of combinations of calcium and phosphate salts to these food products has grabbed great interest.AimIn vitro evaluation of the effect of the addition of 0.2% w/v casein phosphopeptide–amorphous calcium phosphate (CPP–ACP) to four commonly available beverages (of which two were carbonated) on enamel erosion.Materials and methodsSound-extracted human third molar teeth were taken, and enamel sections (n = 270) were made and polished. Acid-resistant nail varnish was painted to create an exposed enamel window of 1 mm2, followed by testing of the four soft drinks and distilled deionized water (DDW). Every drink was evaluated with and without the addition of 0.2% w/v CPP–ACP. The enamel specimens were kept in 50 mL solution at 37°C for 30 minutes, rinsed, and then varnish was removed. All samples were then profiled using white-light profilometer, and erosive depths were recorded.Statistical analysisOne-way analysis of variance test and post hoc Tukey test.ResultsEnamel erosion was created by all the soft drinks tested, but the addition of 0.2% w/v CPP–ACP has remarkably reduced (p value < 0.05) erosive depths in all test solutions compared to solutions without CPP–ACP. The erosive depths for solutions with DDW did not vary much from those with 0.2% CPP–ACP.ConclusionAddition of 0.2% w/v CPP–ACP to the soft drinks has remarkably reduced their erosivity potential.How to cite this articleVelagala D, Reddy VN, Achanta A, et al. Enamel Erosion: A Possible Preventive Approach by Casein Phosphopeptide Amorphous Calcium Phosphate—An In Vitro Study. Int J Clin Pediatr Dent 2020;13(5):486–492.

2,4-dichlorophenoxyacetic acid (2,4-D) micropollutant herbicide removing from water using granular and powdered activated carbons: a comparison applied for water treatment and health safety

Activated carbons are well-known porous materials as an effective adsorbent used for the removal of emerging contaminants, such as herbicides, which are increasingly present in water bodies. Most water treatment plants, specially in Brazil, are unable to completely remove such contaminants by the conventional process and advanced treatment using activated carbons is required. The aim of this paper was to verify the influence of the activated carbons granulometry and specific surface area on the 2,4-dichlorophenoxyacetic acid (2,4-D) herbicide removal efficiency using distilled-deionized water and filtered water collected from a conventional Water Treatment Plant. Commercial activated carbons samples used in this work were obtained from two different manufacturers. Activated carbons were analyzed by the specific surface area, pore size and volume distribution, nuclear magnetic resonance, infrared and x-ray spectroscopy, moisture, volatile matter and ash contents. Batch adsorption isotherms experiments were used and performed by Langmuir and Freundlich models. Granular and powdered activated carbons removed over 99% of 2,4-D in distilled water and near to 99% using filtered water. The activated carbons evaluated in this work presented high performance and played a key role in water treatment by removing 2,4-D herbicide, ensuring the protection of human health and the ecosystem.