Hypochlorite Concentration Research Articles

Shattering the Water Window: Comprehensive Mapping of Faradaic Reactions on Bioelectronics Electrodes.

It is generally accepted that for safe use of neural interface electrodes, irreversible faradaic reactions should be avoided in favor of capacitive charge injection. However, in some cases, faradaic reactions can be desirable for controlling specific (electro)physiological outcomes or for biosensing purposes. This study aims to systematically map the basic faradaic reactions occurring at bioelectronic electrode interfaces. We analyze archetypical platinum-iridium (PtIr), the most commonly used electrode material in biomedical implants. By providing a detailed guide to these reactions and the factors that influence them, we offer a valuable resource for researchers seeking to suppress or exploit faradaic reactions in various electrode materials. We employed a combination of electrochemical techniques and direct quantification methods, including amperometric, potentiometric, and spectrophotometric assays, to measure O2, H2, pH, H2O2, Cl2/OCl-, and soluble platinum and iridium ions. We compared phosphate-buffered saline (PBS) with an unbuffered electrolyte and complex cell culture media containing proteins. Our results reveal that the "water window"─the potential range without significant water electrolysis─varies depending on the electrolyte used. In the culture medium that is rich with redox-active species, a window of potentials where no faradaic process occurs essentially does not exist. Under cathodic polarizations, significant pH increases (alkalization) were observed, while anodic water splitting competes with other processes in media, preventing prevalent acidification. We quantified the oxygen reduction reaction and accumulation of H2O2 as a byproduct. PtIr efficiently deoxygenates the electrolyte under low cathodic polarizations, generating local hypoxia. Under anodic polarizations, chloride oxidation competes with oxygen evolution, producing relatively high and cytotoxic concentrations of hypochlorite (OCl-) under certain conditions. These oxidative processes occur alongside PtIr dissolution through the formation of soluble salts. Our findings indicate that the conventional understanding of the water window is an oversimplification. Important faradaic reactions, such as oxygen reduction and chloride oxidation, occur within or near the edges of the water window. Furthermore, the definition of the water window significantly depends on the electrolyte composition, with PBS yielding different results compared with culture media.

Near-Infrared Fluorescent Turn-On Probe for Selective Detection of Hypochlorite in Aqueous Medium and Live Cell Imaging.

Hypochlorite, as an important reactive oxygen species (ROS), plays a vital role in many physiological and pathological processes, but an excess concentration of hypochlorite (ClO-) may become toxic to humans and cause disease. Hence, the selective and rapid detection of hypochlorite (ClO-) is necessary for human safety. Here, we report a novel near-infrared (NIR) fluorescence "turn-on" and highly selective benzophenoxazinium chloride-based fluorescent probe, BPH (benzophenoxazinium dihydroxy benzaldehyde), for hypochlorite detection. Due to hypochlorite-induced vicinal diol oxidation to the corresponding ortho benzoquinone derivative, the photoinduced electron transfer (PET) process, which was operating from vicinal diol to the benzophenoxazinium chloride receptor moiety, was suddenly inhibited, as a result of which strong NIR fluorescence "turn-on" emission was observed. The detection limit of BPH was found to be 2.39 × 10-10 M, or 0.23 nM. BPH was successfully applied for exogenous and endogenous hypochlorite detection in live MDA-MB 231 cells.

A dual sensitive fluorescence probe for the simultaneous visualization of hypochlorite and viscosity in living cells and zebrafish

As vital microenvironmental indicators, hypochlorite and viscosity levels can be applied to diagnose diseases. Thus, real time and in situ monitoring of hypochlorite and viscosity has gained increasing attentions. A fluorescence probe named JDK was developed by using a novel acceptor of 2-(2-(5-(dimethylamino)thiophen-2-yl)vinyl)-1,3,3-trimethyl-3H-indol-1-ium fluorophore basing on FRET and TICT system. JDK possessed large Stokes shift, broad emission peak gap, prominent photostability and biocompatibility. JDK could track hypochlorite with rapid response time (within 1 min) and low detection limit (28.5 nM). Meaningfully, JDK was favor to append on mitochondria where physiological processes can be disrupted deriving from the abnormal concentrations of hypochlorite and viscosity. Successfully, JDK could visualize endogenous hypochlorite and viscosity in living cells and zebrafish.

RESISTÊNCIA DA UNIÃO DE SISTEMAS ADESIVOS À DENTINA: INFLUÊNCIA DO HIPOCLORITO DE SÓDIO

The modification of the root canal system is of paramount importance to the success of endodontic treatment. This study aimed to evaluate the influence of sodium hypochlorite at concentrations of 2.5% and 4.5% in times of 30 and 60 minutes on the bond strength of composite resin to dentin. We used for this study teeth 20, which were divided into five groups of four elements, each element of the experimental group was immersed in a characteristic time and concentration of sodium hypochlorite of their group and the control immersed in saline. Later there were three composite restorations on each tooth, totaling a sample of 60 restorations. Each restaurant had its bonding to dentin submitted to microshear test, and the results were analyzed through statistical tests: the normal, anova and multiple variations. No significant influence on the adhesion of composite resins to dentin at a concentration of 2.5% at times of 30 and 60 minutes, and concentration of 4.5% in 30 minutes time. There was only influences the concentration 4.5% after a time of 60 minutes. It is concluded that sodium hypochlorite at 4.5% in contact with the dentine for a time of 60 minutes because influence on the bond strength of resin composite, which may cause recontamination of the channel system.

Current Endodontic Practices among Romanian Dental Practitioners: A Cross-Sectional Study.

Root canal therapy (RCT) is usually performed in Romania by general dentists (GDPs) because they are more readily available and more reasonably priced than endodontists. Concerns have been raised about the quality of RCTs performed by GDPs, possibly due to insufficient equipment or knowledge; therefore, this study aims to investigate current endodontic practices in Romania. Materials and Methods: A cross-sectional study was conducted via a questionnaire distributed to 400 randomly selected Romanian dentists, with 285 fully validated completed responses (71.25% response rate). Respondents were grouped by speciality, and statistical analysis, including cross-tabulation and the χ2 (chi-square) test, was used, with a significance level set at p ≤ 0.05 for all tests. Results: Significant differences were found in the use of magnification, rubber dam, sodium hypochlorite concentration, and bioceramics (p < 0.001). No significant differences were observed in preferences for measuring working length (p = 0.166) or rotary instrument motion (p = 0.289). Approximately 6% of the respondents used laser technology with no significant difference across specialities (p = 0.571). Additionally, 77.9% preferred using sodium hypochlorite, with no significant difference between groups (p = 0.006) regarding concentration. Conclusions: Most participants, including GDPs, use modern equipment and techniques during RCT, indicating their awareness and competence in current endodontic practices.

Comparative evaluation of effectiveness of different concentration of sodium hypochlorite with conventional irrigation method versus ultrasonic irrigation in the elimination of Enterococcus faecalis from root canals: an in-vitro study

Aim: The aim of this study is to compare the decrease in bacterial population in the root canals with 3 different concentrations of NaOCl and with two different irrigation systems Methods and Material: The study was conducted on 70 single rooted extracted teeth. Teeth were decoronated and the apices were sealed with auto polymerizing resin. The teeth were inoculated with a suspension comprising Enterococcus faecalis (E. faecalis). The canals were prepared were divided into three groups based on irrigation technique: Group 1; irrigation with 1% sodium hypochlorite, Group 2; irrigation with 3% sodium hypochlorite &amp; Group 3; irrigation with 5% sodium hypochlorite. All three groups were divided into 2 subgroups. In subgroup A irrigation was done by conventional side vented needle and in subgroup B with passive ultrasonic agitation. A fourth control group was also added in which conventional needle irrigation was done with normal saline. The samples were inoculated on the growth media and the mean colonies units were calculated. Statistical analysis used: The statistical analysis used was Student’s unpaired t-test for intergroup comparison and one-way ANOVA and Tukey’s post hoc test for intragroup comparison. Results: In our study, groups with passive ultrasonic irrigation showed better antimicrobial effect compared to groups which use conventional needle irrigation. Conclusions: Ultrasonic irrigation showed better antimicrobial activity compared to conventional needle irrigation

Enhancing Root Canal Therapy with NIR-II Semiconducting Polymer AIEgen and Low-Concentration Sodium Hypochlorite Synergy.

Despite significant efforts to eliminate bacterial biofilm within root canals, achieving effective disinfection remains challenging due to the complex anatomy and limitations of disinfectants. In this study, a second near-infrared (NIR-II) semiconducting polymer with aggregation-induced emission (AIE) properties, named PIDT-TBT, is deliberately designed and synthesized. This proposes an AIE luminogen-based sterilization strategy in synergy with a low concentration of sodium hypochlorite (NaClO). Water-dispersible PIDT-TBT nanoparticles (NPs) are prepared, demonstrating good biocompatibility, as well as photothermal and photodynamic properties. Subsequent antibacterial tests show that PIDT-TBT NPs exhibit excellent bactericidal effects against three bacterial strains: Staphylococcus aureus, Streptococcus mutans, and Enterococcus faecalis, upon 808nm laser irradiation. In synergy with a low concentration of NaClO (0.5%) solution, PIDT-TBT NPs significantly improves the outcome of root canal treatment under 808nm laser irradiation in a human extracted tooth root canal infection model. Additionally, it is found that PIDT-TBT NPs combine with a low concentration of NaClO solution could safely dissolve dentin debris and further increase the efficiency of root canal preparation by altering the elemental composition of the inner root canal wall.

Cytotoxic Effect of Two Different Concentrations of Sodium Hypochlorite: An In-Vitro Study.

Introduction The endodontic treatment of primary teeth presents considerable complications due to their distinct anatomical properties. In order to achieve a successful endodontic treatment, certain factors must be assessed. These factors include a precise diagnosis, thorough cleaning, and a reliable disinfection protocol. Although sodium hypochlorite (NaOCl) has been effective as an irrigation agent in primary teeth, it is important to recognize that higher concentrations of NaOCl might possibly inflict toxic harm on the periapical environment if they penetrate the tooth's apical foramina. Since primary teeth are important, pediatric dentists must choose an appropriate NaOCl concentration for root canal irrigation, as higher concentrations can be toxic. Thus, the current investigation examined the cytotoxicity of two different NaOCl concentrations at various volumes. Methods To evaluate the cytotoxicity potential, a culture ofnauplii (brine shrimp) was prepared and subjected to testing. For the test, 5, 10, 20, and 40 µL of 1% and 3% NaOCl were added to the brine shrimp culture at different concentrations, and saline was used as a control. After a span of 24 hours, the total number of alive nauplii was duly noted. Results After 24 hours, nauplii showed no mortality in the control group. For 1% NaOCl, mortality ranged from 10% to 20% across volumes, with no significant differences (p = 0.193). In contrast, 3% NaOCl caused significantly higher mortality: 20% at 5 µL, 30% at 10 and 20 µL, and 60% at 40 µL (p = 0.007). Tukey's analysis revealed no significant differences for 1% NaOCl (p > 0.05) but significant differences for 3% NaOCl at 40 µL (p < 0.05). Conclusion Based on the results of the present study, it was observed that a 1% NaOCl solution exhibited a lower level of toxicity in comparison to a 3% NaOCl solution. These findings highlight the importance of using lower concentrations of NaOCl for endodontic irrigation in pediatric dentistry to reduce the risk of tissue damage and ensure safer outcomes for young patients.

Comparative evaluation of selected concentrations of sodium hypochlorite on the outcome of endodontic therapy among Ghanaians.

Endodontic treatment is one of the main dental treatments to manage inflamed or infected root canal systems of teeth. The success of endodontic treatment principally depends on eradicating microorganisms in the root canal by chemo-mechanical debridement with irrigation solutions like sodium hypochlorite (NaOCl). NaOCl has been used in concentrations ranging from 0.5% to 5.25%. This study determined the antimicrobial effectiveness of selected concentrations (0.5%, 1.0%, 2.6%, and 5.2%) of NaOCl in endodontic treatment. The study sites were the University of Ghana Dental School (UGDS) and Noguchi Memorial Institute for Medical Research (NMIMR). Sixty infected single-rooted single-canal teeth were used. Before (S1) and after (S2), root canal samples during the endodontic treatment with the selected concentrations of NaOCl were examined via anaerobic and aerobic cultures. The isolates were identified using Matrix Assisted Laser Desorption Ionization-Time Of Flight Mass Spectrometry (MALDI-TOF MS). All S1 samples were positive for cultivable bacteria. Fifty-three (53) different microbial species belonging to 20 different microbial genera were isolated. Streptococcus viridans was the most frequently isolated microbe. There were zero isolates in the root canals irrigated with 2.6% and 5.2% NaOCl. Two teeth had isolates in the groups irrigated with the lower concentrations (0.5% and 1.0%) of NaOCl. The persistent bacteria were one species each of Streptococcus mitis and Streptococcus oralis, respectively. Root canal treatments using chemo-mechanical preparation with the selected concentrations (0.5%, 1.0%, 2.6%, and 5.2%) of NaOCl were effective in significantly reducing the microbial load, and for the 5.2% and 2.6% concentrations, in eliminating all the microorganisms.

Susceptibility of pESI positive Salmonella to treatment with biocide chemicals approved for use in poultry meat processing as compared to Salmonella without the pESI plasmid.

Salmonella is a common cause of human foodborne illness, which is frequently associated with consumption of contaminated or undercooked poultry meat. Serotype Infantis is among the most common serotypes isolated from poultry meat products globally. Isolates of serotype Infantis carrying the pESI plasmid, the most dominant strain of Infantis, have been shown to exhibit oxidizer tolerance. Therefore, 16 strains of Salmonella with and without pESI carriage were investigated for susceptibility to biocide chemical processing aids approved for use in US poultry meat processing: peracetic acid (PAA), cetylpyridinium chloride (CPC), calcium hypochlorite, and sodium hypochlorite. Strains were exposed for 15 s to simulate spray application and 90 min to simulate application in an immersion chiller. All strains tested were susceptible to all concentrations of PAA, CPC, and sodium hypochlorite when applied for 90 min. When CPC, calcium hypochlorite, and sodium hypochlorite were applied for 15 s to simulate spray time, strains responded similarly to each other. However, strains responded variably to exposure to PAA. The variation was not statistically significant and appears unrelated to pESI carriage. Results highlight the necessity of testing biocide susceptibility in the presence of organic material and in relevant in situ applications.

Cytotoxic effect of 1% and 3% Sodium hypochlorite as irrigation agent in primary teeth on human red blood cells: an in vitro study

Background and objectives. The endodontic treatment of primary teeth presents significant challenges due to their unique anatomical characteristics. To ensure a successful treatment, it is essential to evaluate a few factors. These factors include accurate diagnosis, disinfection protocol, intracanal medicaments, and irrigation solutions. While Sodium hypochlorite (NaOCl) has gained success as an irrigation agent in primary teeth, it is important to note that higher concentrations of NaOCl can potentially cause toxicity to the periapical environment if they pass through the tooth's apical foramina. Thus, this study compared the cytotoxicity of two different concentrations of sodium hypochlorite at varied volumes on red blood cells (RBC). Materials and methods. In order to evaluate the cytotoxicity potential, fresh human blood was collected from a single healthy individual and subjected to testing. For the test, 10 µL, 20 µL, 30 µL, 40 µL and 50 µL of 1% and 3% NaOCl were added to the RBC. The tubes were gently mixed and incubated at 37°C for 30 minutes. A UV-visible spectrophotometer was used to calculate the absorbance of the supernatant at a wavelength of 540 nm. Results. There was no significant difference in 1% sodium hypochlorite at different volumes with a p value &gt;0.05 using Tukey's post hoc test. However, there was a significant difference between the volumes of 3% sodium hypochlorite at 40 and 50 µg/ml with a p value of 0.004 and 0.001 respectively. Conclusions. According to the current study's findings, 1% sodium hypochlorite solution exhibited less toxicity than 3% sodium hypochlorite.

Web-Based Survey on Regenerative Endodontic Practices among Members of the American Association of Endodontists

IntroductionThe American Association of Endodontics (AAE) Regenerative Endodontics Committee reports here the web-based survey data of regenerative endodontic procedures performed by the AAE members from 2008 to 2019. MethodsThe web-based survey consisted of 2 questionnaires, a revascularization and a follow-up, including clinical and radiographic data at 3, 6, 12 or >12 months after treatment. Data from demographics, etiology, clinical protocols, radiographic, and clinical outcome as perceived by the clinicians were recorded. From 927 entries, 184 full cases were submitted and 126 were suitable for radiographic analysis. The data were divided into cases with 6–12 months and cases with >12 months recall time. Descriptive statistics and univariate analyses were performed. ResultsPredominantly patients were male (63%), average 10 years-old with anterior teeth (77.2%) due to trauma (69.6%). A wide variation in regenerative endodontic procedures protocols was reported by the AAE members. The most common clinical protocols used minimal instrumentation (75.5%), 2.5% or higher concentrations of sodium hypochlorite (83.7%), and antibiotic paste as intracanal medication (58.7%). The majority reported blood clot formation (56%) and most common coronal capping material was white mineral trioxide aggregates (50.5%). Increases in radiographic root length, and radiographic root area were proportional to the time lapsed after treatment. Overall, case outcomes were categorized by clinicians as successful (54.3%), uncertain (23.9%), and unsuccessful (3.8%). ConclusionsThis web-based survey provides a valuable perspective on case selection, clinical protocols, and perceived outcomes for regenerative endodontic procedures and supports the need for future higher level evidence studies.

Evaluation of Hypochlorite Concentration in Household Bleaches as Colour Removal Agent on Coloured Cotton Fabrics

Bleaches are known to remove stains from fabric. This study evaluates chlorine-based household bleaches as effective fabric colour removal agents and was conducted in the Chemistry and Textile laboratories of the Federal University of Agriculture, Abeokuta using experimental design. Five common household bleaches were collected from markets in study areas. The concentrations of Sodium hypochlorite in each bleach sample as indicated by the manufacturer were: A (3.85%), B (3.5%), C (not available), D (4.3%) and E (5.3%). To confirm the concentration of sodium hypochlorite in each bleach sample, Redox titration was conducted. One-minute Spot Test was used to determine the time taken for each bleach sample to remove colour (black, brown, navy blue, purple and army-green) from fabrics samples and similar test conducted with pure sodium hypochlorite (7.21% Chlorine) as control. The L*a*b* values for fabric colour change were obtained from images of the fabric samples using Fiji-Image J and Corel Photo-Paint 17. The laboratory analysis and evaluation revealed the concentration of hypochlorite in the bleaches samples as A: 0.36% (3.56 g/dm3), B: 3.5% (34.00g/dm3), C: 1.15% (11.48g/dm3), D: 4.29% (42.92g/dm3), and E: 0.06% (0.57g/dm3); therefore, established the information on bleaches B and D product package. The average time (seconds) to remove colour from fabric samples by bleach samples were A- 80.37; B- 19.60; C- 30.36; D- 20.10; E- no vivid colour change after 120.00 sec while colour change was obtained 7.00 sec by the control. Furthermore, Image J analysis and L*a*b* values show colour changes on fabric samples with Bleach B ((x ̅= 75.74) and D ((x) ̅= 61.22) most effective in colour removals. In conclusion, Chlorine base household bleaches containing above 1.0% V/v hypochlorite are suitable colour removal agents on coloured fabrics and not stain removals only. Consumers must be careful how to handle Chlorine household bleaches and coloured fabrics

Minimal inhibitory concentration (MIC) of sodium hypochlorit against bacterial isolate from equipment in the microbiology laboratory

Microbiology laboratory equipment is susceptible to bacterial contamination and therefore has the potential to become a medium for the spread of disease and infection. The existence of a less than sterile microbiological analysis process in the STIKes Karsa Husada Garut Microbiology Laboratory causes bacterial contamination of laboratory equipment such as bacterial analysis that does not comply with standards or the use of less than sterile equipment. To control the spread of contaminants, a decontamination process is required using a chemical disinfectant, namely sodium hypochlorite. Measuring the effectiveness of a disinfectant by looking at or can be determined by the Minimum Inhibitory Concentration (MIC). The aim of this research was to determine the effectiveness of sodium hypochlorite disinfectant in inhibiting the growth of microorganisms in bacterial isolates from the STIKes Karsa Husada Garut Microbiology Laboratory equipment. The data analysis used was analyzed descriptively. The results of this research are the Minimum Inhibitory Concentration (MIC) of sodium hypochlorite disinfectant on bacterial isolates from the STIKes Karsa Husada Garut Microbiology Laboratory equipment at a concentration of 4%. So it can be concluded that sodium hypochlorite disinfectant with a concentration of 4% is effective in inhibiting the growth of microorganisms.

ANALYSIS OF MICRO-NUTRIENTS COMPOSITION OF COCOYAM (COLOCASIAE ESCULENTA) AND SWEET POTATO (IPOMOEA BATATAS L) LEAVES IN MELON SOUP

The study ascertained the micro-nutrient composition of cocoyam and sweet potato leaves in melon soups.The study was conducted to identify vitamins and mineral composition in three types of melon soups. Theinstrument adopted for the study was laboratory analysis of food nutrients using official methods ofAssociation of Official Analytical Chemists. The data for micro nutrients were collected in triplicates fromthe melon soups in the food analysis laboratory, raw triplicate values of each micro nutrient in the soupswere collected and analyzed usingX±SD and ANOVA statistics to test the hypotheses 1 – 4. The findingsrevealed that cocoyam and sweet potato leaves melon soups are as rich as fluted pumpkin leaf melon soup inmicro nutrients, such as vitamin A (Iµ) 16.03: 16.80 while fluted pumpkin 19.88; vitamin C (mg) 26.30:36.89 while fluted pumpkin 28.46; folic acid (mg) 33.44: 40.64 while fluted pumpkin 46.73 among others.For minerals- Na (mg) 29.80: 26.16 while fluted pumpkin 34.19; Fe (mg) 1.41: 1.60 while fluted pumpkin1.24 K (mg) 36.08: 46.46 while fluted pumpkin 34.57; Ca (mg) 11.19: 8.10 while fluted pumpkin 5.88; Mg(mg) 4.62: 3.53 while fluted pumpkin 2.63 among others. The study also showed that there was a significantdifference between the mean values of the micro-nutrients analysis. The study recommended that, theconsumption of cocoyam and sweet potato leaves should be encouraged by families in the country, as wellbe made available in the open market same way the popular vegetables are sold such as fluted pumpkin(Ugu) leaf.

A Sublethal Concentration of Chlorine Induces Antibiotic Resistance in Salmonella via Production of Reactive Oxygen Species

Studies have shown that the production of reactive oxygen species (ROS) is triggered by bactericidal antibiotics, which contributes significantly to the killing of bacterial cells and increasing mutations in surviving cells. In this study, we hypothesized that exposure of Salmonella to sublethal concentrations of hypochlorite (NaOCl), a commonly used sanitizer in household and food industries increases mutation rates, leading to the development of antibiotic resistance. We found that a sublethal concentration (20 ppm) of NaOCl increased the mutation rates of S. typhimurium 14028s significantly (p &lt; 0.05), which was prevented by the ROS scavenger thiourea, supporting that the increased mutation was due to NaOCl-triggered ROS production. We further found that the exposure of S. typhimurium 14028s to the same sublethal concentration of NaOCl increases resistance to kanamycin among the 3 antibiotics evaluated. The results of this study suggest that when NaOCl applied as a sanitizer fails to kill Salmonella due to diluted local concentrations or presence of organic materials, it can cause an adverse outcome of developing antibiotic resistance of the pathogen.

Antimicrobial action, cytotoxicity and erosive potential of hypochlorous acid obtained from an electrolytic device compared with sodium hypochlorite.

This study aimed to compare the antimicrobial action, cytotoxicity, cleaning ability, and erosion of dentine of hypochlorous acid (HClO) obtained from an electrolytic device at two different concentrations (Dentaqua) and three concentrations of sodium hypochlorite (NaOCl). Microbiological test-The root canals of sixty single-rooted extracted human teeth were inoculated with Enterococcus faecalis and divided into 6 groups (n = 10), according to decontamination protocol: DW (control); 1% NaOCl; 2.5% NaOCl; 5.25% NaOCl; 250 ppm HClO and 500 ppm HClO. The colony-forming units were counted to evaluate the decontamination potential of each group, calculating the reduction in bacterial percentage. Cytotoxicity test-Cytotoxicity was evaluated after inoculation of the same tested protocols in fibroblastic cells for 3 min, calculating the cell viability percentages. Specifical statistical analysis was performed (α = 5%). Cleaning ability and erosion-Fifty-six single-rooted bovine lower incisors were divided into seven groups of 8 roots each, being the test groups 1% NaOCl; 2.5% NaOCl; 5,25% NaOCl; 250 ppm HClO and 500 ppm HClO, and a negative and positive control. Negative control was not contaminated, and the other groups were inoculated with Enterococcus faecalis. SEM images were ranked as from the cleanest to the least clean. Erosion was also assessed, being ranked from the least to the most eroded dentine. The highest bacterial reduction was observed in experimental groups, with no statistical differences between them (p > 0.05). The highest number of viable cells was observed in control group, followed by 250 ppm HClO and 500 ppm HClO groups, with statistical differences between them (p < 0.05). 1% NaOCl; 2.5% NaOCl; 5.25% NaOCl and 500 ppm HClO displayed the cleanest areas. All sodium hypochlorite groups displayed erosion with higher ranks with greater concentration, while hypochlorous acid did not display any erosion regardless the concentration. It is possible to conclude that HClO obtained from an electrolytic device presented high antimicrobial activity and low cytotoxicity in both tested concentrations. 500 ppm HClO did not display erosion and showed great cleaning ability. The use of 500 ppm hypochlorous acid may reduce unfavorable behavior of sodium hypochlorite whilst maintaining its antimicrobial action.

INCREASING SOME FLAVONOIDS COMPOUNDS FOR ECHINACEA PURPUREA L. USING COPPER OXIDE NANOPARTICLES IN VITRO.

This study was aimed to increase some flavonoids active compounds production in Echinacea purpurea seedlings through plant seeds treatment with different concentrations of copper oxide nanoparticles that daignosed and characterized using AFM technique. This research was implemented at plant tissue culture labrotary of College of biotechnology - Al Nahrain University, during the period of 2021 and 2023. The experiment designed factorial within CRD using three factors and ten replicates (3X3). Sodium hypochlorite concentration (S1, S2, S3, S4) (0.0, 1, 2, 3%) represented the first factor, treatment duartion time (T1, T2, T3) (5, 10, 15min) represented the second factor and copper oxide nanoparticles concentrations (C1, C2, C3, C4) (0.0, 25, 50, 75mg/ml) represented the third factor. Results showed that the full reduction in the contamination rate of the selected E. purpurea explant recorded in 3% sodium hypochlorite at 10 and 15min. The results also showed that there were a significant increase in the shoots numbers in 50mg/ml CuNPs that recording the highest shoots numbers, the shoot length increased significantly within the 25mg/ml recording 13.5cm then decreased in 50 and 75 mg/ml and the seedlings dry weight increased significantly up to 50mg/ml CuNPs that recording the highest seddlings dry weight, then the seedlings dry weight also decreased significantly in 75mg/ml CuNPs. Also, all the analyzed flavonoids compounds using HPLC device as Echinolone, Humulene, Coumarin, Myricetin, Heperidin and Naringin concentrations were significantly increased in 50 and 75 mg/L-1 Cu ONPs, except the Humulene and Coumarin compound that significantly decreased in 75 mg/L-1 Cu ONPs in comparsion to the control.

Optimization of Sterilization Parameters for Isolation of Endophytes from Allium sativum and Exploring its Antibacterial Activity

Endophytic bacteria reside within the plant cell and are beneficial to it in a number of ways like growth, protection to environmental conditions and sustainability in favor of the hosts. Throughout the ages, Garlic (Allium sativum L.) has legendary therapeutic importance. The important step in endophyte isolation is the removal of plant tissue surface microflora, called as surface sterilization. Endophytes from medicinal plants may mimic the compound produced by the host plant and also plays an important role in production of bioactive compound, so it is necessary to isolate endophytes, not the epiphytic microbes. The present investigation was undertaken with an aim to optimize the sterilization parameters viz: time and concentration of ethanol and sodium hypochlorite for isolation of endophytic bacteria as well as exploring their antibacterial activity from Allium sativum. The results revealed that concentration and exposure time of sterilizing agent caused prominent surface sterilization but have negative effect on isolation of endophytes. Experimental results revealed that 70% ethanol (6 min), 2% sodium hypochlorite (1 min) followed by 70% ethanol (30 sec) is effective for surface sterilization of leaf and 70% ethanol (6 min), 3% sodium hypochlorite (1 min) followed by ethanol (30 sec) for bulb of Allium sativum. A total of 86 bacterial endophytes were recovered and screened for antibacterial activity against Enterococcus faecalis, Bacillus cereus ATCC 11778, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Enterobacter, Klebsiella pneumoniae, Salmonella typhi and Proteus. Out of 86 bacterial endophytes, only (9%) endophytes were found to be inhibiting one or all test human pathogen. The findings of the present study suggest that use of optimized sterilization conditions are effective for removing surface bacterial strains without affecting endophytes as well as the Allium sativum plant of the Jaunpur district represents an excellent reservoir of endophytic bacteria and novel source of bioactive compounds. On the other hand different concentration and time of their exposure to different parts of plant is required for proper surface sterilization of that part and isolation of endophytes.

Chlorination of Pseudomonas aeruginosa in potable water

ABSTRACT The present study examined the effects of chlorine (NaOCl) disinfection on Pseudomonas aeruginosa in potable water. The adhesion of the bacteria on glass surfaces and the growth of the adherent cells were measured after treatment with chlorine (0, 0.25, 0.5, 0.75, and 1 mg/L). Adhesion was assessed by optical microscopy, and cultivability of the adherent cells was estimated by counting the bacteria on solid medium after being recovered from the support surface. Regardless of the concentration applied, P. aeruginosa did not lose the ability to adhere or grow after adhesion. However, the two factors were influenced by the chlorine treatments. The results showed that the adhesive capacity and cultivability of adherent cells were linked. The maximum inhibition of adherence and cultivability was observed in the 0.25 and 0.5 mg/L treatments. At 0.75 and 1 mg/L, the adhesive capability and post-adhesive cultivability were slightly increased. The results suggest that residual concentrations of sodium hypochlorite fixed by standards (less than 1 mg/L) may be ineffective against P. aeruginosa, and thus could have an impact on consumers.