EDTA Solution Research Articles

Performance, kinetics and mechanism of Fe(II)EDTA regeneration with surface-fluorinated anatase TiO2 with exposed (001) facets

Fe(II)EDTA regeneration mainly referring to Fe(III)EDTA and Fe(Ⅱ)EDTA-NO reduction has a very remarkable significance for NO removal using Fe(II)EDTA solution. Here, surface-fluorinated anatase TiO2 nanosheets with exposed (001) facets (F-TiO2) was prepared and firstly served for Fe(II)EDTA regeneration with ultraviolet light. The performance and kinetics of Fe(II)EDTA regeneration had been investigated under different F-TiO2 dose, varied pH, and diverse temperatures, in which Fe(III)EDTA and Fe(II)EDTA-NO reduction rate raised and then decreased under pH increasing or F-TiO2 dose rise. High temperature was conducive to Fe(II)EDTA regeneration. Fe(III)EDTA and Fe(II)EDTA-NO reduction presented first order reaction. Moreover, the F-TiO2 still maintained an excellent reduction efficiency after three recycle. Mechanism study showed that excellent Fe(II)EDTA regeneration ability could be partly explained by the high separation efficiency of photogenerated electrons and holes of F-TiO2. The bonded NO was converted into NH4+, N2, and N2O. Finally, compared with other Fe(II)EDTA regeneration systems, photocatalytic regeneration is a more suitable alternative in Fe(II)EDTA complexation denitrification technology.

Fabrication of metal-organic frameworks with trimesic linkers for europium adsorption and recovery from aqueous solutions

This work reports on the effective sequestration of Eu(III) ions from aqueous solutions using three types of metal-organic frameworks (MOFs) constructed from benzene-1,3,5-tricarboxylic acid (H3BTC) linker and Ca2+, Cu2+, or Al3+ metal nodes. The MOFs possessed an exceptionally high Eu adsorption capacity of 635 (91% removal), 642 (92% removal), and 628 mg g−1 (90% removal) for Cu-BTC, Ca-BTC, and Al-BTC, respectively, at pH 7 for an initial Eu concentration of 350 mg L−1. The MOFs were hydrolytically stable and possessed a high Eu adsorption capacity in a wide pH range of 4–8. While the pseudo-second-order model explained the adsorption kinetics, the adsorption process followed the Langmuir-Freundlich isotherms. The analysis confirmed that the Eu adsorption process was governed by chemical interactions between the carboxylic acid/carboxylate group and Eu(III) ions via complexation or ion exchange mechanism. A multi-metal adsorption study confirmed a preferential adsorption behaviour for trivalent lanthanides over divalent cations due to comparatively stronger interactions between Ln3+ ions and carboxylate groups. The XPS findings suggested Eu−OOC and Eu(OH)3 formed over the MOFs' surface after Eu adsorption. These MOFs were effectively regenerated for multiple cycles using 0.1 mol L−1 EDTA solution. Thus, the study demonstrated low-cost MOFs with superior regeneration capabilities for the capture of Eu(III) ions from waste solutions.

Developing thiosemicarbazide-modified/ion-imprinted chitosan for selective cadmium ion biosorption

To ensure environmental and industrial sustainability, cadmium ions (Cd(II)) must be extracted from effluents. However, high-efficiency Cd(II) extraction remains elusive due to issues with slow rates and low selectivity. An ion-imprinting method was used in this study to imprint Cd(II) onto a thiosemicarbazide-chitosan derivative (TCCS) synthesized via an unconventional synthetic route. Following the amide bond formation between cyanoacetyl units and chitosan, thiosemicarbazide was used to modify the –CN residues to obtain the desired TCCS derivative. After that, the Cd(II) ions were coordinated with the TCCS before being cross-linked with epichlorohydrin (ECH) and eluted by a H+/EDTA solution, leaving rigid coordination cavities. The developed Cd-TCCS was able to preferentially identify Cd(II) when compared to non-imprinted sorbent, resulting in significantly higher adsorption capabilities (qm = 305 ± 1 mg/g) and enhanced adsorption selectivity. Also, the pseudo-second-order kinetics model was a good fit for the data, indicating that adsorption is mainly mediated by chemisorption or coordination mechanisms, which were confirmed by the FTIR and XPS investigations. This study expands our understanding of the factors that influences the biosorption of Cd(II) from aqueous media and gives a direction for the development of novel biosorbents with high capacity and excellent selectivity.

Highly efficient sulfonated poly (ether ether ketone) (sPEEK) adsorbent for removal of uranium (VI) from aqueous solution

Sulfonated polyether ether ketone (sPEEK) polymer matrix was used as adsorbent for uranyl adsorption for first time. sPEEK showed high affinity against uranyl cations and the maximum adsorption capacity was found as 0.82 mmol/g. The maximum adsorption was achieved at pH 6. The adsorption kinetic was described by pseudo-second order model. Pore diffusion was involved in adsorption but not rate controlling step. The adsorption reaction is endothermic, and the activation energy is 85.8 kJ/mol. The desorption kinetics into 2 M HNO3, 0.1 M Na2CO3, 0.05 M EDTA and 5 % citric acid solutions were searched, and 99 % desorption was achieved when 0.05 M EDTA and 2 M HNO3 were used as leaching solution. The recovery efficiency decreased from 98 % to 88 % in 0.05 M EDTA solution and from 96 % to 86 % in 2 M HNO3 solution at the end of the fifth cycle. Uranium removal and recovery from liquid waste generated by mining and nuclear plants is of great importance. This study presents an opportunity for highly efficient removal using a low-cost and easily handled sorbent, as well as high recovery of uranyl ions with the aid of a common eluent, allowing for five cycles.

Endodontic tooth treatment with internal root resorption: case report

INTRODUCTION: Internal tooth resorption is characterized by the destruction of dentin in the root canal wall due to an imbalance of clastic cell activity resulting mainly from trauma. Thus, endodontic treatment is indicated with the aim of removing the etiology of resorption by using intracanal medication to combat possible infection and thus provide tissue repair. OBJECTIVE: The aim of this study is to investigate the treatment of root resorption by conventional endodontic therapy by identifying internal resorption and highlighting the steps of endodontic treatment. CASE REPORT: The methodology adopted was a clinical study in which we selected a female patient who required endodontic treatment of tooth 12 with pulp necrosis and resorption in the middle third of the root. Thus, the endodontic treatment was performed according to the technique, through instrumentation of the root canal followed by irrigation with sodium hypochlorite 6%. After instrumentation, the PUI (Ultrasonic Passive Irrigation) was performed followed by irrigation with 6% sodium hypochlorite and EDTA solution. The root canal was also dried and filled, allowing the respective tooth to be provisionally restored with glass ionomer so that it could later be permanently restored according to the indication of the material. Therefore, internal tooth resorption causes irreversible damage to the individual, such as tooth loss, thus altering the functioning of the stomatognathic system. Thus, endodontic treatment has great advantages in the treatment of teeth with internal tooth resorption since it promotes stagnation of the resorption process and tissue repair. CONCLUSIONS: Therefore, the treatment of internal tooth resorption requires close attention by the dental surgeon due to careful evaluation throughout the entire clinical case.

Temperature Changes during Er:YAG Laser Activation with the Side-Firing Spiral Endo Tip in Root Canal Treatment

Erbium-doped yttrium aluminum garnet (Er:YAG) laser-activated irrigation (LAI) is used in endodontic treatment to remove the smear layer and kill bacteria in the root canal. However, this procedure can cause photo-thermal effects that harm the surrounding tissue. Therefore, it was important to study the temperature changes that occur at the outer tooth surface during activation of the Er:YAG laser using a side-firing spiral Endo tip in the root canal. Laser treatment was performed either in the absence of fluid in the root canal or in the presence of a 17% EDTA solution. Irrigation with 17% EDTA was either performed in a continuous mode for 60 s or in a segmented mode of 4 rinses with 17% EDTA for 15 s each. The temperature was measured every second during the treatment at three tooth surface sites: the cementoenamel junction, the middle region and the apical region. Our data show that the greatest temperature changes occurred when the laser was used alone without an irrigation solution, while minor temperature changes were observed with continuous irrigation. In conclusion, we would recommend applying the laser treatment with an irrigation solution to avoid excessive heating.

Rapid Detection of Cd2+ Ions in the Aqueous Medium Using a Highly Sensitive and Selective Turn-On Fluorescent Chemosensor.

Herein, a novel optical chemosensor, (CM1 = 2, 6-di((E)-benzylidene)-4-methylcyclohexan-1-one), was designed/synthesized and characterized by 1H-NMR and FT-IR spectroscopy. The experimental observations indicated that CM1 is an efficient and selective chemosensor towards Cd2+, even in the presence of other metal ions, such as Mn2+, Cu2+, Co2+, Ce3+, K+, Hg2+,, and Zn2+ in the aqueous medium. The newly synthesized chemosensor, CM1, showed a significant change in the fluorescence emission spectrum upon coordination with Cd2+. The formation of the Cd2+ complex with CM1 was confirmed from the fluorometric response. The 1:2 combination of Cd2+ with CM1 was found optimum for the desired optical properties, which was confirmed through fluorescent titration, Job's plot, and DFT calculation. Moreover, CM1 showed high sensitivity towards Cd2+ with a very low detection limit (19.25 nM). Additionally, the CM1 was recovered and recycled by the addition of EDTA solution that combines with Cd2+ ion and, hence, frees up the chemosensor.

MP05-14 ENHANCED POPCORNING USING POLYANIONIC SOLUTIONS AS IRRIGATION

You have accessJournal of UrologyCME1 Apr 2023MP05-14 ENHANCED POPCORNING USING POLYANIONIC SOLUTIONS AS IRRIGATION Daniel Wong, Alex Shiang, Connor McCormick, Adam Ostergar, Henry Lai, and Kenneth Sands Daniel WongDaniel Wong More articles by this author , Alex ShiangAlex Shiang More articles by this author , Connor McCormickConnor McCormick More articles by this author , Adam OstergarAdam Ostergar More articles by this author , Henry LaiHenry Lai More articles by this author , and Kenneth SandsKenneth Sands More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003216.14AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: The goal of popcorning or pop-dusting is to reduce stone fragments to submillimeter size, allowing spontaneous passage through the urinary tract. Polyanionic compounds can dissolve human calcium oxalate kidney stones. We explore the novel application of polyanionic solutions to enhance popcorning efficiency. METHODS: BegoStones with matching size and mass were treated in a 12 mm test tube calyceal model with a 60 W TFL (SOLTIVE, Olympus). 200 mm fiber was introduced into our model calyx through a flexible ureteroscope and positioned 1-2 mm from the stones. Stones were treated at 1.0 J × 40 Hz for 4 minutes with irrigation at 30 ml/min. We compared sodium chloride (NaCl), sodium citrate (Citrate), sodium hexametaphosphate (HMP), and sodium EDTA (EDTA) solutions. The osmolality of all solutions was matched to 0.9% NaCl. The pH for solutions of NaCl, EDTA, HMP, and Citrate was 6.0, 8.3, 6.7, and 8.6 respectively. After treatment, stones were passed through a 1 mm sieve and remaining fragments weighed. The primary outcome was residual stone mass >1 mm. RESULTS: The average remaining stone mass >1 mm after 17 observations with NaCl irrigation was 27.8% (±10.0%). After 15 observations with HMP, Citrate, and EDTA irrigation, the average remaining stone mass >1 mm was 28.9% (±13.4%), 17.5% (±10.5%), and 9.8% (±5.7%) respectively (Figure 1). HMP had no significant effect on residual stone burden compared with NaCl. There was a 37% reduction in residual stone mass when using Citrate compared with NaCl (p=0.008). Using EDTA reduced residual stone mass by 65% compared with NaCl (p<0.001). CONCLUSIONS: Citrate and EDTA show promising results for enhancing the efficacy of popcorning in this in vitro model. Further testing will be required to determine effectiveness on different stone types and safety on urothelium in short duration. Source of Funding: Midwest Stone Institute © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e48 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Wong More articles by this author Alex Shiang More articles by this author Connor McCormick More articles by this author Adam Ostergar More articles by this author Henry Lai More articles by this author Kenneth Sands More articles by this author Expand All Advertisement PDF downloadLoading ...

Simultaneous Reduction of NO/SO2 Gas Using Fe(II)EDTA Solution at Low Temperature Conditions and Analysis of Solution Regeneration Characteristics by Zn

Simultaneous Reduction of NO/SO2 Gas Using Fe(II)EDTA Solution at Low Temperature Conditions and Analysis of Solution Regeneration Characteristics by Zn

Effectiveness of Morinda citrofolia, Sapindus mukorossi, and curcumin used in curry spice, to the radicular canal irrigant in improving bond integrity of glass fiber post

AimEvaluation of the push-out bond strength (PBS) of glass fiber reinforced post (GFRP) bonded to root dentin after canal disinfection using food-based root canal irrigants i.e., Curcumin photosensitizer (CP), Riboflavin photosensitizer (RFP), Morinda ctrifolia juice (MCJ) and Sapindus mukorossi (SM) along with MTAD as a final irrigant. Material methodsFifty human single-rooted premolar teeth were decoronated. Endodontic preparation was performed along with 2.25% sodium hypochlorite NaOCl solution followed by EDTA solution. Canals were dried and obturated followed by post-space preparation by removing GP. Specimens were allocated into five groups based on different food-based disinfection regimes (n = 10). Group 1: 2.25% NaOCl + MTAD (Control), Group 2: 6% MCJ + MTAD, Group 3: SM + MTAD, Group 4: CP + MTAD and Group 5: RFP + MTAD. All GFRP were bonded to radicular dentin. Root sectioning was performed followed by PBS and failure analysis using a universal testing machine (UTM) and stereomicroscope respectively. The data were analyzed using a one-way analysis of variance (ANOVA) test and the Post Hoc Tukey HSD test (p = 0.05). ResultsSamples disinfected with(MCJ+MTAD) at coronal third demonstrated maximum PBS (9.41 ± 0.51 MPa). However, the apical third of group 5 (RFP + MTAD) exhibited the minimum values (4.06 ± 0.23 MPa). Intergroup comparison analysis unveiled that group 2 (MCJ +MTAD) and group 3 (SM+MTAD) displayed comparable outcomes of PBS at all three-thirds. Similarly, samples in group 1 (2.25% NaOCl + MTAD), group 4 (CP + MTAD), and group 5 (RFP + MTAD) exhibited comparable PBS. ConclusionFruit-based irrigants Morinda citrifolia and Sapindus mukorossi have the potential to be used as root canal irrigants with a positive influence on bond strength.

Mobility indexes of Cu, Pb, and Zn in soil ecosystems with various levels of metal contamination (in Poland)

The aim of the study was to investigate and compare the soils of three groups of grassland ecosystems with varying degrees of heavy metal (Cu, Pb, and Zn) pollution as well as estimating of mobility on the basis of calculated mobility indexes (MI) expressed as a percentage of the EDTA-extracted forms of metals in their total content. A total of 55 surface soil samples were collected from various areas of Poland: urban soils, rural soils, and soils along communication routes. Heavy metal concentrations were determined in solutions after wet mineralization (using a mixture of acids) by atomic absorption spectrometry (AAS) with flame atomization. To isolate the mobile forms of metals in soils, a one-step extraction method was used with 0.05-M EDTA solution. The ranges of Cu, Pb, and Zn concentrations in soils were varied, respectively: 6.7–47.6, 61.1–563.9, and 86.4–644.5 mg·kg−1 (A); 5.7–39.8, 13.56–45.71, and 16.3–119.6 mg·kg−1 (B); and 1.0–195.8, 19.2–310.2, and 27.4–894.1 mg·kg−1 (C). The average values of mobility indexes of Cu, Pb, and Zn were at the level of 40.9, 33.5, and 22.2% (A); 23.2, 27.1, and 25.9% (B); and 37.5, 34.3, and 30.7% (C). Studies have shown that metals derived from anthropogenic sources are characterized by greater mobility compared to metals of natural origin (lithological associated with the ground). The inclusion of metal mobility indices in the environmental monitoring strategy may minimize errors in assessing the actual risk associated with the potential uptake of these metals by plants and incorporation into circulation.

Efficacy of Smear Layer Removal at the Apical One-Third of the Root Using Different Protocols of Erbium-Doped Yttrium Aluminium Garnet (Er:YAG) Laser.

Background and Objectives: Smear layer forms during cleaning and shaping can obstruct the entry of both irrigant and sealant into the dentinal tubules, resulting in the accumulation of the bacteria and their byproducts. To ensure effective adhesion and better periapical healing, it is strongly advised to remove the smear layer before proceeding with root canal obturation. This study was designed to compare the efficiency of laser-activated irrigation (LAI) in removing the smear layer and debriding the most apical third of the root canal. Materials and Methods: Sixty-five extracted human teeth with straight single roots were randomly and equally divided into four laser and one control groups. Root canals in all samples were shaped using prime size TruNatomy rotary files. During preparation, each canal was irrigated with 3 mL of 3% NaOCl and 3 mL of 17% EDTA alternately, followed by the irrigation with 10 mL of distilled water to avoid the prolonged effect of EDTA and NaOCl solutions. Final irrigation of 5 mL of 17% EDTA of the root canal was done to eliminate the smear layer and was subsequently activated by an endodontic ultrasonic tip for 20 s three times (control group), a flat-end laser tip (test groups 1 and 3) or a taper-end laser tip (test groups 2 and 4) for two cycles. The time of each cycle activation was 10 s (groups 1 and 2) or 20 s (groups 3 and 4) in which the Er:YAG laser of 2940 nm was used. The laser operating parameters were 15 Hz and 50 μs pulse duration. The samples were then split longitudinally and subjected to scanning electron microscopy (SEM). Results: The remaining smear layer at the apical part of the root canals was statistically significant between the control group and the laser groups 1 (p = 0.040) and 2 (p = 0.000). Within the laser groups, the exposed tubules count was greater in the laser with the flat tip as compared with the tapered tip (Laser 1 > Laser 2 and Laser 3 > Laser 4). Finally, no significant differences in the count of debris between the laser groups and control group were observed, except for laser 4 (p < 0.05), which had the highest count of debris. Conclusion: LAI to remove debris and smear layer at the apical third of the root canal is inferior to the current ultrasonic technique. However, when using the Er:YAG LAI, it is recommended to use a flat tip design for 10 s for two cycles to ensure maximum debridement of the apical dentin surface.

A Novel D-π-A Type Fluorescent Probe for Cu2+ Based on Styryl-Pyridinium Salts Conjugating Di-(2-picolyl)amine (DPA) Units.

A novel D-π-A type fluorescent probe L(NO3) for Cu (II) sensing was designed and fully characterized. The probe consists of a styryl-pyridine cation fluorescent group and a di-(2-picolyl)amine (DPA) receptor unit, which are linked by a phenyl group to form an electron donor-π-acceptor (D-π-A) conjugate system, especially the introduction of a nitrate counter anion for significantly enhanced water solubility of the probe. Fluorescence titration studies of the probe L(NO3) showed a higher selectivity for Cu2+ than other metal ions, and the emission spectrum was strongly quenched upon binding. The competitive binding assay and the low detection limit (0.932 µM) showed that the probe L(NO3) had strong anti-interference ability and excellent Cu2+ detection performance. The binding ratio of probe L(NO3) and Cu2+ was determined from Job's plot to be 1:1, which is consistent with the results obtained from X-ray crystal structures. Meanwhile, the probe showed instantaneous chemical reversibility when titrated with EDTA solution, indicating potential recycling properties of the probe. In addition, the design of inexpensive fluorescent test strips can perform the on-site and real-time detection Cu2+ with a color recognition application.

Stimuli-responsive SERS biosensor for ultrasensitive tetracycline sensing using EDTA-driven PEI@CaCO3 microcapsule and CS@FeMMs

In this work, a stimuli-responsive SERS biosensor was fabricated for tetracycline (TTC) by “signal-on” strategy using (EDTA)-driven polyethyleneimine grafted calcium carbonate (PEI@CaCO3) microcapsule and chitosan-Fe magnetic microbeads (CS@FeMMs). Initially, aptamer conjugated magnetic-bead CS@FeMMs@Apt with superparamagnetism and excellent biocompatibility was employed as capture probe, which facilitated the rapid and easy magnetic separation. Subsequently, the PEI cross-linked layer and aptamer network layer were constructed onto the outer layer of CaCO3@4-ATP microcapsule to form sensing probes (PEI@CaCO3@4-ATP@Apt) via the layer-by-layer assembly method. In the presence of TTC, a sandwich SERS-assay was exploited by aptamer recognition induced target-bridged strategy. When the solution of EDTA was added, the core layer of CaCO3 would be dissolved quickly, destroying the microcapsule to release 4-ATP. The released 4-ATP could be quantitatively monitored by dripping the supernatant onto the AuNTs@PDMS SERS platform, resulting in a strong Raman “signal-on”. Under the optimal conditions, a good linear relationship was established with a correlation coefficient (R2) of 0.9938 and a LOD of 0.03 ng/mL. Additionally, the application capacity of the biosensor to detect TTC was also affirmed in food matrixes, and the results were consistent with the standard ELISA method (P > 0.05). Hence, this SERS biosensor affords extensive application prospects for TTC detection with multiple merits such as high sensitivity, environment friendliness, and high stability.

Polydopamine microcapsules loaded Ag nanoparticles for catalytic reduction of organic pollutants

We demonstrate a simple approach for fabricating polydopamine microcapsules decorated with silver nanoparticles (Ag@PDA MCs) as highly efficient catalysts for water purification. Polydopamine microcapsules (PDA MCs) were formed on the MnCO3 template from self-polymerization and the removal of template under mild EDTA solution, followed by in situ reduction of Ag+ by PDA and growth of monodispersed Ag nanoparticles. Under optimized conditions, the Ag@PDA MCs exhibits 41.56 wt% of Ag loading contents and superior catalytic performance for the degradation of organic pollutants with rate constant of 2.93 min-1 for methylene blue and 1.03 min-1 for 4-nitrophenol. The excellent catalytic activity can mainly be ascribed to high surface roughness of microcapsules, high Ag loading ratio, and uniform distribution of Ag nanoparticles. In addition, this catalyst can be recycled for five times with degradation efficiency higher than 98%. The Ag@PDA MCs possessed fast reduction rate, high catalytic activity, and good recyclability as well as facile preparation and easy separation, showing great potential for the application in wastewater treatment.

Kök Kanal Tedavisinde Kullanılan Farklı İrrigasyon Solüsyonlarının Yüzey Gerilimlerinin Karşılaştırılması

Amaç: Bu çalışmanın amacı kök kanal tedavisinde kullanılan farklı irrigasyon solüsyonlarının yüzey gerilimi değerlerini karşılaştırmaktır. Gereç ve Yöntem: %5.25 NaOCl, %9 HEBP, %2 PAA, %17 EDTA, %5.25 NaOCl + %9 HEBP, %5.25 NaOCl + %2 PAA, %5.25 NaOCl + %17 EDTA solüsyonlarının yüzey gerilimi değerleri damla şekli analiz cihazı DSA30 (Kruss, Hamburg, Almanya) ile ölçüldü. Her irrigasyon solüsyonu için 10 ayrı ölçüm yapıldı. Veriler mj/m2 cinsinden kaydedildi. Grupların ortalama ve standart sapma değerleri, tek yönlü ANOVA ve Bonferroni ve Tukey Çoklu Karşılaştırma Testleri yapılarak istatistiksel olarak değerlendirildi. Bulgular: En yüksek yüzey gerilim değerini %5.25 NaOCl + %2 PAA solüsyonu, en düşük değeri %9 HEBP solüsyonu gösterdi. %5.25 NaOCl+ %2 PAA grubunun yüzey gerilimi, %5.25 NaOCl, %9 HEBP, %2 PAA, %5.25 NaOCl+ %9 HEBP gruplarından istatistiksel olarak daha yüksekti (p&amp;lt;0.05). %5.25 NaOCl, %9 HEBP, %2 PAA ve %5.25 NaOCl+ %9 HEBP grupları arasında istatistiksel açıdan herhangi bir fark bulunmadı (p&amp;gt;0.05). Sonuç: Test edilen irrigasyon solüsyonları arasında %9 HEBP solüsyonu en düşük yüzey gerilimine sahipti.

Spatially selective cell treatment and collection for integrative drug testing using hydrodynamic flow focusing and shifting.

Hydrodynamic focusing capable of readily producing and controlling laminar flow facilitates drug treatment of cells in existing microfluidic culture devices. However, to expand applications of such devices to multiparameter drug testing, critical limitations in current hydrodynamic focusing microfluidics must be addressed. Here we describe hydrodynamic focusing and shifting as an advanced microfluidics tool for spatially selective drug delivery and integrative cell-based drug testing. We designed and fabricated a co-flow focusing, three-channel microfluidic device with a wide cell culture chamber. By controlling inlet flow rates of sample and two side solutions, we could generate hydrodynamic focusing and shifting that mediated precise regulation of the path and width of reagent and drug stream in the microfluidic device. We successfully validated a hydrodynamic focusing and shifting approach for spatially selective delivery of DiI, a lipophilic fluorophore, and doxorubicin, a chemotherapeutic agent, to tumor cells in our device. Moreover, subsequent flowing of a trypsin EDTA solution over the cells that were exposed to doxorubicin flow allowed us to selectively collect the treated cells. Our approach enabled downstream high-resolution microscopy of the cell suspension to confirm the nuclear delivery of doxorubicin into the tumor cells. In the device, we could also evaluate in situ the cytotoxic effect of doxorubicin to the tumor cells that were selectively treated by hydrodynamic flow focusing and shifting. These results show that hydrodynamic focusing and shifting enable a fast and robust approach to spatially treat and then collect cells in an optimized microfluidic device, offering an integrative assay tool for efficient drug screening and discovery.

Facile green preparation of single- and two-component modified activated carbon fibers for efficient trace heavy metals removal from drinking water

Trace heavy metals exist in drinking water, having great adverse effects on human health and making it a huge challenge to remove. Herein, novel materials have been prepared by a simple and green method using single- (polydopamine (PDA) or 2,3-dimercaptopropanesulfonic sodium (DMPS)) (PDA-OACF or DMPS-OACF) and two-component (PDA and DMPS) (DMPS-PDA-OACF) functionalized activated carbon fibers pretreated by hydrogen peroxide for the removal of trace heavy metals. The as-prepared DMPS-OACF (7.5,20) under DMPS addition of 7.5 mg and sonication time of 20 min retained large specific surface area, micro-mesoporous structure and rich functional groups and showed better adsorption performance for trace lead and mercury. It also exhibited wide applicable ranges of pH (3.50–10.50) and concentration (50–1136 μg L−1), rapid adsorption kinetics, and excellently selective removal performance for trace lead. The maximum lead adsorption capacity reached 16.03 mg g−1 when the effluent lead concentration met World Health Organization (WHO) standard and the adsorbent can be regenerated by EDTA solution. The fitting results of adsorption kinetics and isotherm models revealed that the lead adsorption process was multi-site adsorption on heterogeneous surfaces and chemical adsorption. The excellent adsorption properties for trace heavy metals were attributed that the sulfur/oxygen/nitrogen-containing functional groups boosted diffusion and adsorption by electrostatic attraction and coordination, suggesting that DMPS-OACF (7.5,20) has great application potential in the removal of trace heavy metals.

Assessment of the Clinical Outcomes of Single Visit Regenerative Endodontic Procedure In Treating Necrotic Mature Teeth with Apical Periodontitis Using Biological Irrigating Solution

Aim: to observe the effect of propolis and its nano counterpart when used as final irrigation materials and compare them to the conventionally used EDTA and saline on the clinical outcomes of necrotic mature anterior teeth with apical periodontitis after treating them using regenerative endodontic procedure.&#x0D; Methodology: 84 patients who fulfilled the inclusion criteria were recruited for the study. Access cavity was prepared, rubber dam isolation was done. Mechanical preparation was performed up to #60 using K-files. Final irrigation procedure was done as follows:&#x0D; Group A (Control ): Final irrigation was done using saline (3ml/min) followed by 17% EDTA solution (20 mL/canal, 5 min).&#x0D; Group B (comparator 1): Final irrigation was done using propolis[1] irrigation (20 mL/canal, 5 min).&#x0D; Group C (comparator 2): Final irrigation was done using Nano-propolis[2] irrigation (20 mL/canal, 5 min).&#x0D; Bleeding was then induced, PRF was placed in the canals, followed by Collacote[3] and Bio-dentine[4] placement. Patients were recalled after 6 and 12 months. Teeth were checked for sensibility using electric pulp tester and thermal tests. All data was analysed using Kruskal Wallis test.&#x0D; Results: All of the 84 patients (100%) within the 3 groups showed both clinical success and survival. Using Kruskal Wallis, there was no statistically significant difference among the three groups (p=1). Two teeth in the nano propolis group responded positively to thermal test at 12 months follow up. None of the teeth in the three tested groups (100%) responded to the&#x0D; electric pulp test at 12 months. There was nostatistically significant difference between the three groups(p=1)&#x0D; Conclusion: within the limitation of the study, single visit regenerative endodontics can be used to treat necrotic mature teeth with apical periodontitis and a periapical lesion.&#x0D; Key words: Regenerative endodontics, single visit regeneration, propolis, Nano-propolis, Platelet-rich fibrin&#x0D; &#x0D; [1] Propolis: Imtinan/Cairo, Egypt&#x0D; [2] Nanopropolis: NanoTech/Cairo/Egypt&#x0D; [3] Collacote: Collacote/Zimmer/Indiana /USA&#x0D; [4] Biodentine: Acrostone/Cairo/Egypt&#x0D;

A protocol for the extraction of viable bacteria for identification of bacterial communities in bentonite

Bentonite is a clay material with a broad range of applications in construction, industry (food, pharmacy), and civil engineering including water treatment and waste disposal. It has also been proposed as a buffer and backfill material in deep geological repositories (DGRs). However, the presence of metabolically active bacteria in bentonite could compromise the long-term safety of such DGRs, highlighting the need for a method for detection of microorganisms in bentonite materials. Here, we propose a novel protocol for the detection of both living (metabolically active and dead indigenous bacterial cells in bentonite. The extraction protocol requires the addition of a dispersant (2.5 mM sodium pyrophosphate (NaPP)/12.5 mM EDTA solution or 1% methanol) to a bentonite sample, followed by a two-step centrifugation over high-density media (i.e., sucrose and histodenz) to separate and concentrate the cells. The extracted bacterial cells can then be examined by epifluorescence microscopy using LIVE/DEAD staining and using molecular biology methods. Overall, the NaPP-based dispersant afforded a better extraction efficiency (20%) than methanol (6%). The light clay fraction acted as a sieve effectively retaining dispersed cells during centrifugation; this light clay fraction with attached cells being later detected in the final extracts. Importantly, the microbial community composition detected in cell extracts by 16S rRNA sequencing corresponded to that in the original suspension. The protocol has been successfully applied on different bentonite samples in different environments, demonstrating the high potential of this approach for evaluation of microbial activity in bentonite.