Synthesis of magnetic biochar composite using Vateria indica fruits through in-situ one-pot hydro-carbonization for Fenton-like catalytic dye degradation

The present study reports the synthesis, characterization, and application of sustainable magnetic biochar composite. The inedible fruits of Vateria indica, a powerful ayurvedic plant were hydrothermally transformed into magnetic biochar (BC-Fe3O4) in a single step and characterized by several sophisticated techniques. FESEM analysis portrayed fibrous irregular mesh-like biochar with surface clustered Fe3O4 nanoparticles, while the incidence of carbon, oxygen, and iron in the elemental analysis by EDS established magnetic biochar formation. Numerous peaks consistent with planes of (220), (311), (400), (422), (511), (440), and (120) also substantiated the occurrence of magnetite nanoparticles and biochar respectively, as analyzed by XRD. XPS analysis showed signals at 285.65 eV, 533.28 eV, 711.08 eV, and 724.68 eV corroborating a strong C-O bond, O1s orbit, Fe2+, and Fe3+ respectively. BC-Fe3O4 was superparamagnetic with saturation magnetization of 4.74 emu/g, as per VSM studies, while its specific surface area, pore volume, and pore diameter were 5.74 m2/g, 0.029 cm3/g, and 20.86 nm respectively. The Fenton-like degradation of methylene blue (5.0-25.0 ppm) was accomplished by synthesized BC-Fe3O4, in the presence of H2O2. Within 180 min, almost complete degradation was achieved, with first-order kinetics having rate constants between 0.0299 and 0.0167 min-1. Stability and recyclability studies performed over 7 cycles exhibited unaltered degradation between 93.98 and 97.59%. This study exhibits the exceptional characteristics and degradation capabilities of BC-Fe3O4 synthesized from a sustainable plant biomass.

Application of chemically modified waste tucumã (Astrocaryum aculeatum) seeds in the biosorption of methylene blue: kinetic and thermodynamic parameters

Dye effluents cause diverse environmental problems. Methylene blue (MB) dye stands out since it is widely used in the textile industry. To reduce the pollution caused by the MB, we developed biosorbents from tucumã seeds, where the in natura seeds were treated with NaOH (BT) and H3PO4 (AT) solutions and characterized by Boehm titration, point of zero charges, FTIR, TGA, BET, and SEM. It was observed that the acid groups predominate on the surface of the three biosorbents. The process was optimized for all biosorbents at pH = 8, 7.5 g/L, 240 min, C0 = 250 mg/L, and 45 ℃. BT was more efficient in removing MB (96.20%; QMax = 35.71 mg/g), while IT and AT removed around 60% in similar conditions. The adsorption process best fits Langmuir and Redlich-Peterson isotherms, indicating a hybrid adsorption process (monolayer and multilayer) and pseudo-second-order kinetics. Thermodynamic data confirmed an endothermic and spontaneous adsorption process, mainly for BT. MB was also recovered through a desorption process with ethanol, allowing the BT recycling and reapplication of the dye. Thus, an efficient and sustainable biosorbent was developed, contributing to reducing environmental impacts.

Effectiveness of sentinel lymph node biopsy and bilateral pelvic nodal dissection using methylene blue dye in early-stage operable cervical cancer-A prospective study

OBJECTIVE

To evaluate the effectiveness of methylene blue dye in detecting sentinel lymph nodes (SLNs) in women with early-stage operable (defined as FIGO I-IIA) cervical cancer. It also aims to evaluate procedural challenges and accuracy.

METHOD

This prospective study, which focused on 20 women with early-stage cervical cancer, was carried out between June 2016 and December 2017. These patients had SLN mapping with methylene blue dye injections and thorough examinations, including imaging. All patients underwent radical hysterectomy and complete bilateral pelvic lymphadenectomy. No additional investigation was done on the lymph node in cases where a metastasis was found in the first H&E-stained segment of the sentinel node.

RESULT

20 patients were included in the analysis. The median age of the subjects was 53, and 95 % of them had squamous cell carcinoma. 90 % of the time, the identification of SLNs was effective, and 55 SLNs were found, of which 52.7 % were on the right side of the pelvis and 47.3 % on the left. The obturator group had the most nodes, followed by the external and internal iliac groups in descending order of occurrence. Metastasis was detected in 3 patients, resulting in a sensitivity of 100 % and a specificity of 93.75 % for SLN biopsy. Notably, no false-negative SLNs were found. Complications related to methylene blue usage included urine discoloration in 30 % of patients.

CONCLUSION

This trial highlights the promising efficacy and safety of methylene blue dye alone for SLN identification in early-stage operable cervical cancer, with a notably higher success rate. Despite limitations like a small sample size, healthcare professionals and researchers can build upon the insights from this study to enhance cervical cancer management.

Comparative study of synthesis methods and pH-dependent adsorption of methylene blue dye on UiO-66 and NH2-UiO-66

Metal-organic frameworks (MOFs) are highly promising adsorbents with notable properties such as elevated adsorption capacities and versatile surface design capabilities. This study introduces two distinct synthesis methods, one lasting 1 h and the other 24 h, for UiO-66 and NH2-UiO-66. While both methods yield structures with comparable crystallinity and morphology, the adsorption performance of the cationic methylene blue dye varies at different pH levels. Despite the 24 h synthesis time being optimal for maximum adsorption in both MOFs, the relative difference in NH2-UiO-66 adsorption percentage at different times suggests reduced dependency on synthesis time for this property. Notably, NH2-UiO-66 exhibits consistent and effective performance across three pH levels, warranting further investigation into its adsorption kinetics and isotherm. The achievement of high adsorption efficiency coupled with a significantly reduced synthesis time underscores the importance of developing simplified synthetic methods, essential for enhancing the practical applicability of MOFs in diverse applications.

A comparative study on green synthesis and characterization of Mn doped ZnO nanocomposite for antibacterial and photocatalytic applications

Biological and green synthesis of nanomaterial is a superior choice over chemical and physical methods due to nanoscale attributes implanted in a green chemistry matrix, have sparked a lot of interest for their potential uses in a variety of sectors. This research investigates the growing relevance of nanocomposites manufactured using ecologically friendly, green technologies. The transition to green synthesis correlates with the worldwide drive for environmentally sound procedures, limiting the use of traditional harsh synthetic techniques. Herein, manganese was decorated on ZnO NPs via reducing agent of Withania-extract and confirmed by UV-spectrophotometry with highest peak at 1:2 ratio precursors, and having lower bandgap energy (3.3 eV). XRD showed the sharp peaks and confirms the formation of nanoparticles, having particle size in range of 11-14 nm. SEM confirmed amorphous tetragonal structure while EDX spectroscopy showed the presence of Zn and Mn in all composition. Green synthesized Mn-decorated ZnO-NPs screened against bacterial strains and exhibited excellent antimicrobial activities against gram-negative and gram-positive bacteria. To check further, applicability of synthesized Mn-decorated Zn nanocomposites, their photocatalytic activity against toxic water pollutants (methylene blue (MB) dye) were also investigated and results showed that 53.8% degradation of MB was done successfully. Furthermore, the installation of green chemistry in synthesizing nanocomposites by using plant extract matrix optimizes antibacterial characteristics, antioxidant and biodegradability, helping to build sustainable green Mn decorated ZnO nanomaterial. This work, explains how biologically friendly Mn-doped ZnO nanocomposites can help reduce the environmental impact of traditional packaging materials. Based on these findings, it was determined that nanocomposites derived from biological resources should be produced on a wide scale to eradicate environmental and water contaminants through degradation.

Expermental investigation on adsorption of methylene blue dye from waste water using corncob cellulose-based hydrogel

Hydrogel from corncob cellulose was synthesized in this investigation. The synthesized Hydrogel was characterized by SEM, XRD, and FTIR instruments. As the results indicate the synthesized hydrogel has required and important features, these suggest the suitability of hydrogel for the adsorption of methylene blue dye (MBD). Three important process variables (dosage, contact time, and initial concentration) with three levels were studied during the adsorption process at 30 °C and neutral pH. The efficiency of hydrogel for adsorption of MBD was determined in each experiment. The experimental results were statistically analyzed and interpreted. The maximum removal efficiency was achieved at 2.22 g/L of dosage, 80.36 min of contact time, and 74.54 mg/L of initial concentration. At this condition, 98.25% of MBD was achieved through experimental tests. Kinetics, isotherm, and thermodynamics studies were performed. Langmuir isotherm is more suitable to describe the adsorption process and the Pseudo second-order kinetic model fits this process. From the thermodynamics studies, all negative values of change in Gibbs free energy (ΔG°), and positive value of change in enthalpy (ΔH°), and change in entropy (ΔS°) indicate that the carried out experimental process is a spontaneous and endothermic. Moreover, the regeneration experiment for adsorbent was performed. The treatment of real textile industry waste water was conducted and the removal efficiency of hydrogel was 64.76%. This removal percentage reduction from sythetic aqueous solution is due to involvement of other pollutants in the real waste water. The synthesized hydrogel adsorbent is suitable up to the third cycle without significant loss in removal efficiency.

Sustainable production of activated carbon from indigenous Acacia etbaica tree branches employing microwave induced and low temperature activation

Growing demand for activated carbon as an efficient and cost effective means of treating environmental pollution necessitates the economical production of good quality activated carbon. It is possible if it is done using low cost precursor materials and economical production methods. In the present study, two types of activated carbon were produced from Acacia etbaica tree branches while employing phosphoric acid as an activating agent. The first sample underwent carbonization by microwave irradiation (AC-MWI), while the second sample was carbonised in a furnace (AC-CA). Characterization of the formed activated carbon samples was executed by proximate and ultimate analysis adopting standard ASTM procedures. In addition to the elemental analysis, hardness, bulk density, pH, moisture and ash content, surface morphology, BET specific surface area, pore volume, volatile matter, fixed carbon, and iodine number were determined. Characteristics of both activated carbon samples were compared with the characteristics of activated carbon available in the literature and activated carbon available commercially in the market. The comparison revealed that the characteristics of the produced activated carbon samples was well comparable with the activated carbons produced from other species of Acacia tree and activated carbon available commercially. Results showed that the produced activated carbon demonstrated high activation efficiency of 39.8% and 48.7% for AC-CA and AC-MWI, respectively. Furthermore, AC-MWI has a BET specific surface area higher than that of AC-CA (1065 m2/g and 773 m2/g respectively). It was found that the BET specific surface area and pore volume of AC-MWI was higher by 37.7% and 12.7%, respectively, as compared to the values acquired for AC-CA. Additionally, activated carbon could be produced by microwave irradiation in about 48% less time as compared to traditional low temperature heating. The adsorption study of produced the activated carbon was performed utilising methylene blue (MB) as a contaminant, and the data was fitted to Langmuir, Freundlich, as well as Harkins-Jura isotherm showing comparable correlation. However, Freundlich isotherm was found to be the best to elaborate the MB adsorption on the produced activated carbon. The results confirmed the viability of microwave irradiation in producing good quality activated carbon from Acacia etbaica tree branches, which demonstrated comparable characteristics with commercially available activated carbon. The strategy could be beneficial for the country in order to produce high quality activated carbon and strengthen its self-reliance.

Synthesis of oxidized carboxymethyl cellulose-chitosan and its composite films with SiC and SiC@SiO2 nanoparticles for methylene blue dye adsorption

The cationic methylene blue (MB) dye sequestration was studied by using oxidized carboxymethyl cellulose-chitosan (OCMC-CS) and its composite films with silicon carbide (OCMC-CS-SiC), and silica-coated SiC nanoparticles (OCMC-CS-SiC@SiO2). The resulting composite films were characterized through various analytical techniques, including Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Field emission scanning electron microscopy (FESEM), and energy-dispersive X-ray spectroscopy (EDS). The dye adsorption properties of the synthesized composite films were comprehensively investigated in batch experiments and the effect of parameters such as contact time, initial dye concentration, catalyst dosages, temperature, and pH were systematically evaluated. The results indicated that the film's adsorption efficiency was increased by increasing the contact time, catalyst amount, and temperature, and with a decreased initial concentration of dye solution. The adsorption efficiency was highest at neutral pH. The experimental results demonstrated that OCMC-CS films have high dye adsorption capabilities as compared to OCMC-CS-SiC, and OCMC-CS-SiC@SiO2. Additionally, the desorption investigation suggested that the adsorbents are successfully regenerated. Overall, this study contributes to the development of sustainable and effective adsorbent materials for dye removal applications. These films present a promising and environmentally friendly approach to mitigate dye pollution from aqueous systems.

One-step synthesis of magnetic fly ash composites for methylene blue removal: batch and column study

This study focuses on the synthesis of magnetic fly ash composites and its application for the removal of methylene blue (MB) from wastewater. By-product of oil power plants, oil fly ash, was treated with magnetic nanoparticles after chemical surface modification and dubbed modified fly ash (MFA). MFA was characterized by X-ray fluorescence, diffractogram analysis, scanning electron microscopy, energy-dispersive X-ray (EDX), and Fourier transform infrared (FT-IR) and N2 physisorption. MB (methylene blue) was removed from an aqueous solution using the response surface modelling (RSM) technique, which was used for optimization reasons. All four independent factors were investigated to see how they affected the removal process: adsorbent dosage; contact time; pH; and beginning dye concentration. The rate of MB removal was strongly influenced by the pH of the solution. The Langmuir and Freundlich models were used to examine equilibrium data A for MB adsorption onto the MFA in linear and nonlinear forms. Langmuir gave a better fit. The adsorption kinetics shown by increased kinetic statistics were better characterized by a pseudo-second-order MFA model. As far as thermodynamic characteristics go, adsorption is endothermic and occurs spontaneously. It has been proven that MFA may be used as an adsorbent to remove MB dye with high efficiency, and the quadratic model has been proved to be statistically significant.

Boosting the photocatalytic activity of ZnO-NPs through the incorporation of C-dot and preparation of nanocomposite materials

Due to their applications in cosmetology, medicine, antibacterial and other fields, zinc oxide nanoparticles (ZnO-NPs) are among the nanoscale materials experiencing exponential growth. In contrast, pure ZnO-NPs have been reported to have a very large energy bandgap, a large exaction binding energy, electron-hole recombination, no visible light absorption, and poor photocatalytic activities, which limit their potential uses. ZnO-NPs can be further extended through the incorporation of trace amounts of carbon materials to engulf these problems. We investigate the photocatalytic degradation of methylene blue (MB) dye with pure ZnO-NPs infused with a limited amount of carbon dot (C-dot) materials. Consequently, adding 10% C-dot to ZnO-NPs reduced their energy bandgap from 3.1 to 2.8 eV and significantly increased their photocatalytic activity. MB was almost completely degraded (98.4%) after 60 min when 50 mg of C-dot-incorporated ZnO-NPs were added. By comparison, the nanocomposite's photocatalytic activity exceeded that of pure ZnO-NPs by more than 50%. A surface charge and stability improvement are responsible for the extraordinary photocatalytic improvement. As far as we know, this is the best-ever photocatalytic improvement achieved by incorporating a trace amount of C-dot material into pure ZnO-NPs.

Eco-friendly synthesis of a novel adsorbent from sugar cane and high-pressure boiler water

The development of industrial process in line with the circular economy and the environmental, social and corporate governance (ESG) is the foundation for a sustainable economic development. Alternatives that make feasible the transformation of residues in added value products are promising and contributes to the repositioning of the industry towards sustainability, due to financial leverage obtained from lesser operational costs when compared with conventional processes, therefore increasing the company competitivity. In this study is presented a promising and innovative technology for the recycling of agro-industrial residues, the sugarcane bagasse and the high-pressure water boiler effluent, in the development of a low-cost adsorbent (HC-T) using the hydrothermal carbonization process and its application in the adsorption of herbicide Diuron and Methylene Blue dye from synthetic contaminated water. The hydrothermal carbonization was performed in a Teflon contained inside a sealed stainless-steel reactor self-pressurized at 200 °C, biomass-to-effluent (m/v) ratio of 1:3 and 24 h. The synthesized material (HC) was activated in an oven at 450 °C for 10 min, thus being named adsorbent (HC-T) and characterized by textural, structural and spectroscopic analysis. The low-cost adsorbent HC-T presented an 11-times fold increase in surface area and ∼40% increase total pore volume in comparison with the HC material. The kinetic and isotherm adsorption experiments results highlighted that the HC-T was effective as a low-cost adsorbent for the removal of herbicide Diuron and Methylene Blue dye from synthetic contaminated waters, with an adsorption capacity of 35.07 (63.25% removal) and 307.09 mg g^-1 (36,47% removal), respectively.

Development of biohybrid Ag2CrO4/rGO based nanocomposites with stable flotation properties as enhanced Photocatalyst for sewage treatment and antibiotic-conjugated for antibacterial evaluation

The proposed research outlines a facile method to synthesize Silver Chromate/reduced graphene oxide nanocomposites (Ag₂CrO₄/rGO NCs) with a narrow dissemination size for the ecological treatment of hazardous organic dyes. The photodegradation performance toward the decontamination of model artificial methylene blue dye was assessed under solar light irradiation. The crystallinity, particle size, recombination of photogenerated charge carriers, energy gap and surface morphologies of synthesized nanocomposites were determined. The experiment objective is to use rGO nanocomposites to increase Ag₂CrO₄ photocatalytic efficiency in the solar spectrum. Tauc plots of ultraviolet-visible (UV-vis) spectrum were used to calculate the optical bandgap energy of the produced nanocomposites ~1.52 eV, which resulted in a good photodegradation percentage of ~92 % after 60 min irradiation of Solar light. At the same time, pure Ag₂CrO₄ and rGO nanomaterials showed ~46 % and ~ 30 %, respectively. The ideal circumstances were discovered by investigating the effects of several parameters, including catalyst loading and different pH levels, on the degradation of dyes. However, the final composites maintain their ability to degrade for up to five cycles. According to the investigations, Ag₂CrO₄/rGO NCs are an effective photocatalyst and can be used as the ideal material to prevent water pollution. Furthermore, antibacterial efficacy for the hydrothermally synthesized nanocomposite was tested against gram-positive (+ve) bacteria viz. Staphylococcus aureus and gram-negative (-ve) bacteria viz. Escherichia coli. The maximum zone of inhibition for S. aureus and E. coli were 18.5 and 17 mm, respectively.

Nanobioremediation: a bacterial consortium-zinc oxide nanoparticle-based approach for the removal of methylene blue dye from wastewater

Industrial effluents carrying dyes are considered a major environmental threat in the present era. Methylene blue (MB) dye is one of the key dyes of the thiazine group of dyes. It is broadly used in medical, textile, and various fields and is well known for its carcinogenicity and methemoglobin nature. Bacterial and other microbes-mediated bioremediation is becoming an emerging and significant section for the treatment of wastewater. Isolated bacteria were used for the bioremediation and nanobioremediation of methylene blue dye under varying conditions and parameters. A comparative study was conducted for the remediation of methylene blue dye using bacterial consortium, potential bacteria (isolated by scale-up method), and potential bacteria within zinc oxide nanoparticles. The decolorizing ability of bacteria was analyzed by UV visible spectrophotometer after stirring and static incubation in different time intervals of the isolates. Growth parameters and environmental parameters which include pH, initial dye concentration, and dose of nanoparticles were optimized with the minimal salt medium. An enzyme assay study was also done to check the effect of dye and nanoparticles on bacterial growth and the mode of action of degradation. The authors found that potential bacteria within ZnO nanoparticles showed enhanced decolorization efficiency (95.46% at pH 8) due to the properties of nanoparticles. On the other hand, the decolorization of MB dye by potential bacteria and the bacterial consortium was about 89.08 and 76.3%, respectively, for a 10-ppm dye concentration. During the enzyme assays study, the highest activity was observed for phenol oxidase, nicotinamide adenine dinucleotide (NADH), 2,6-Dichloroindophenol(DCIP), and laccase for nutrient broth having MB dye, MB dye, and ZnO NPs, while no such change was observed for manganese peroxidase enzyme activity. Nanobioremediation is a promising approach to removing such pollutants from the environment.

One-pot synthesis of iron oxide - Gamma irradiated chitosan modified SBA-15 mesoporous silica for effective methylene blue dye removal

The development of adsorption technology and the processing of radiation have both been influenced by chitosan adsorbent (γ-chitosan), a raw material with unique features. The goal of the current work was to improve the synthesis of Fe-SBA-15 utilizing chitosan that has undergone gamma radiation (Fe-γ-CS-SBA-15) in order to investigate the removal of methylene blue dye in a single hydrothermal procedure. High-resolution transmission electron microscopy (HRTEM), High angle annular dark field scanning transmission electron microscopy (HAADF-STEM), small- and wide-angle X-ray powder diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR) and Energydispersive X-ray spectroscopy (EDS) were used to characterize γ-CS-SBA-15 that had been exposed to Fe. By using N₂-physisorption (BET, BJH), the structure of Fe-γ-CS-SBA-15 was investigated. The study parameters also included the effect of solution pH, adsorbent dose and contact time on the methylene blue adsorption. The elimination efficiency of the methylene blue dye was compiled using a UV-VIS spectrophotometer. The results of the characterization show that the Fe-γ-CS-SBA-15 has a substantial pore volume of 504 m² g^-1 and a surface area of 0.88 cm³ g^-1. Furthermore, the maximum adsorption capacity (Q_max) of the methylene blue is 176.70 mg/g. The γ-CS can make SBA-15 operate better. It proves that the distribution of Fe and chitosan (the C and N components) in SBA-15 channels is uniform.

Synthesis, characterization and adsorption behavior of modified cellulose nanocrystals towards different cationic dyes

Green and efficient removal of polluted materials are essential for the sustainability of a clean and green environment. Nanomaterials, particularly cellulose nanocrystals (CNCs), are abundant in nature and can be extracted from various sources, including cotton, rice, wheat, and plants. CNCs are renewable biomass materials with a high concentration of polar functional groups. This study used succinic anhydride to modify the surface of native cellulose nanocrystals (NCNCs). Succinic anhydride has been frequently used in adhesives and sealant chemicals for a long time, and here, it is evaluated for dye removal performance. The morphology and modification of CNCs studied using FTIR, TGA & DTG, XRD, SEM, AFM, and TEM. The ability of modified cellulose nanocrystals (MCNCs) to adsorb cationic golden yellow dye and methylene blue dye was investigated. The MCNCs exhibited high adsorption affinity for the two different cationic dyes. The maximum adsorption efficiency of NCNCs and MCNCs towards the cationic dye was 0.009 and 0.156 wt%. The investigation for adhesive properties is based on the strength and toughness of MCNCs. MCNCs demonstrated improved tensile strength (2350 MPa) and modulus (13.9 MPa) using E-51 epoxy system and a curing agent compared to 3 wt% composites. This research lays the groundwork for environmentally friendly fabrication and consumption in the industrial sector.

Utilization of metal industry solid waste as an adsorbent for adsorption of anionic and cationic dyes from aqueous solution through the batch and continuous study

Industrial waste, for instance, textile effluents when released into the ecological system without first being treated or with inappropriate levels of treatment, can lead to serious issues deteriorating the environment and human health. Moreover, solid waste from various industries has also become a major issue due to massive urbanization. For instance, the waste from the metal industry has been rapidly increasing such as Jarosite which has various metals, metal oxides, and silica in its composition. Therefore, Jarosite was utilized as an adsorbent for the adsorption of anionic Congo red (CR) and cationic Methylene blue (MB) dyes from aqueous solutions. The processed adsorbent sample was characterized by BET, XRD, SEM, EDS, FTIR, and XPS techniques. The effects of initial dye concentration, pH, adsorbent dose, temperature, and contact time were examined. The metal industry waste is used as a low-cost abundant adsorbent with great potential for adsorption ability to remove the CR (97.5%) and MB (68.5%) at pH 7, contact time 90 min, adsorbent dose 0.1 g, and initial dye concentration 50 mg/L. The adsorption data followed the adsorption isotherm and Kinetics for both dyes. The removal of both dyes was a physical adsorption process, endothermic and spontaneous reaction. Column adsorption investigation was described by AB (Adams-Bohart) and YN (Yoon-Nelson) models. According to the economic view, the utilization of jarosite for dye removal is a cost-effective approach, because it is collected free of cost from industries. Henceforth, for the first time, toxic metal industry waste was successfully utilized as an adsorbent for wastewater treatment.

Solar light-based advanced oxidation processes for degradation of methylene blue dye using novel Zn-modified CeO2@biochar

Herein, a novel nanocomposite, namely, Zn-modified CeO₂@biochar (Zn/CeO₂@BC), is synthesized via facile one-step sol-precipitation to study its photocatalytic activity towards the removal of methylene blue dye. Firstly, Zn/Ce(OH)₄@biochar was precipitated by adding sodium hydroxide to cerium salt precursor; then, the composite was calcined in a muffle furnace to convert Ce(OH)₄ into CeO₂. The crystallite structure, topographical and morphological properties, chemical compositions, and specific surface area of the synthesized nanocomposite are characterized by XRD, SEM, TEM, XPS, EDS, and BET analysis. The nearly spherical Zn/CeO₂@BC nanocomposite has an average particle size of 27.05 nm and a specific surface area of 141.59 m²/g. All the tests showed the agglomeration of Zn nanoparticles over the CeO₂@biochar matrix. The synthesized nanocomposite showed remarkable photocatalytic activity towards removing methylene blue, an organic dye commonly found in industrial effluents. The kinetics and mechanism of Fenton-activated dye degradation were studied. The nanocomposite exhibited the highest degradation efficiency of 98.24% under direct solar irradiation of 90 min, at an optimum dosage of 0.2 g l^-1 catalyst and 10 ppm dye concentration, in the presence of 25% (V/V) 0.2 ml (4 µl/ml) hydrogen peroxide. The hydroxyl radical generated from H₂O₂ during the photo-Fenton reaction process was attributed to the nanocomposite's improved photodegradation performance. The degradation process followed pseudo-first-order kinetics having a rate constant (k) value of 0.0274 min^-1.

Green synthesis of chitosan/erythritol/graphene oxide composites for simultaneous removal of some toxic species from simulated solution

In this study, chitosan (Ch) is adapted via green methodology including sonication induced crosslinking with different weight ratios of erythritol (Er) from (Ch-Er)1 to (Ch-Er)4. The products were casted in the form of thin films. The chemical modification was proved via FTIR spectroscopy. Then, the modified products were verified via an atomic force microscopy (AFM) investigation for their topography and surface properties. The data revealed that the optimized sample was (Ch-Er)3. This sample was further modified by different weight ratios of graphene oxide 0.1, 0.2, 0.4, and 0.8 wt./wt. (symbolized as (Ch-Er)3GO1, (Ch-Er)3GO2, (Ch-Er)3GO4, and (Ch-Er)3GO8 respectively). The prepared samples were investigated by different analytical tools. Then, the adjusted sample (Ch-Er)3GO2 was irradiated by electron beam (e-beam) at 10 and 20 kGy of irradiation doses to give samples (Ch-Er)3GO2R10 and (Ch-Er)3GO2R20, respectively. The AFM data of the irradiated samples showed that the pore size decreases, and surface roughness increases at higher energy e-beam due to the formation of more crosslinking points. The optimum samples of the prepared formulations were tested as sorbent materials for simultaneous elimination of methylene blue (MB) dye and mercury cation (Hg2+) from simulated solutions. The maximum removal of both MB dye and Hg2+ cation was achieved by (Ch-Er)3GO2R10 (186.23 mg g-1 and 205 mg g-1) respectively.

Green synthesized cobalt oxide nanoparticles with photocatalytic activity towards dye removal

The present study aimed at the synthesis of cobalt oxide nanoparticles (CONPs) mediated by leaf extract of Muntingia calabura using a rapid and simple method and evaluation of its photocatalytic activity against methylene blue (MB) dye. UV-vis absorption spectrum showed multiple peaks with an optical band gap of 2.05 eV, which was concordant with the literature. FESEM image signified the irregular-shaped, clusters of CONPs, and EDX confirmed the existence of the Co and O elements. The sharp peaks of XRD spectrum corroborated the crystalline nature with a mean crystallite size of 27.59 nm. Raman spectrum substantiated the purity and structural defects. XPS signified the presence of Co in different oxidation states. FTIR image revealed the presence of various phytochemicals present on the surface and the bands at 515 and 630 cm^-1 designated the characteristic Co-O bonds. VSM studies confirmed the antiferromagnetic property with negligible hysteresis. The high BET specific surface area (10.31 m²/g) and the mesoporous nature of the pores of CONPs signified the presence of a large number of active sites, thus, indicating their suitability as photocatalysts. The CONPs degraded 88% of 10 mg/L MB dye within 300 min of exposure to sunlight. The degradation of MB dye occurred due to the formation of hydroxyl free radicals on exposure to sunlight, which followed first-order kinetics with rate constant of 0.0065 min^-1. Hence, the CONPs synthesized herein could be applied to degrade other xenobiotics and the treatment of industrial wastewater and environmentally polluted samples.

Adsorption performance and mechanism of cationic and anionic dyes by KOH activated biochar derived from medical waste pyrolysis

The massive generation of medical waste (MW) results in a series of environmental, social, and ecological problems. Pyrolysis is one such approach that has attracted more attention because of the production of value-added products with lesser environmental risk. In this study, the activated biochar (ABC600) was obtained from MW pyrolysis and activated with KOH. The adsorption mechanism of activated biochar on cationic (methylene blue) and anionic (reactive yellow) dyes were studied. The physicochemical characterization of biochar showed that increasing pyrolysis temperature and KOH activation resulted in increased surface area, a rough surface with a clear porous structure, and sufficient functional groups. MB and RYD-145 adsorption on ABC600 was more consistent with Langmuir isotherm (R² ≥ 0.996) and pseudo-second-order kinetics (R² ≥ 0.998), indicating chemisorption with monolayer characteristics. The Langmuir model fitting demonstrated that MB and RYD-145 had maximum uptake capacities of 922.2 and 343.4 mg⋅g^-1. The thermodynamics study of both dyes showed a positive change in enthalpy (ΔH°) and entropy (ΔS°), revealing the endothermic adsorption behavior and randomness in dye molecule arrangement on activated-biochar/solution surface. The activated biochar has excellent adsorption potential for cationic and anionic dyes; hence, it can be considered an economical and efficient adsorbent.

Photocatalytic degradation of methylene blue dye using newly synthesized zirconia nanoparticles

Zirconium oxide nanoparticles (ZrO₂NPs) were prepared using the leaf extract of Muntingia calabura as a reductant. The absorption peak at 232 nm confirmed the signature peak for ZrO₂NPs with band energy at 5.07 eV. The ZrO₂NPs were tetragonal and highly crystalline, possessing a mean diameter of 14.83 nm as confirmed by XRD studies. The lattice constants (a = 0.362 nm and c = 0.511 nm) were consistent with the literature. Spherical nanoaggregates (29.25 nm) were seen in FESEM image and the specific signals for Zr and O were noticed in EDS image. The tetragonal phase of the ZrO₂NPs were further confirmed from the XPS and Raman studies. PL spectrum had a sharp emission at 493 nm. The FTIR spectrum revealed the presence of various functional groups. ZrO₂NPs were thermally stable with 5.76% total weight loss - as revealed from TGA profile. The photocatalytic breakdown of methylene blue (MB) dye under the influence of solar irradiation was performed using ZrO₂NPs which exhibited 89.11% degradation within 5 h. Hence, the synthesized ZrO₂NPs can be used as an alternate potential photocatalyst for the degradation of various dyes present in waste streams.

Remediation of groundwater contaminated with dye using carbon dots technology: Ecotoxicological and microbial community responses

Groundwater pollution poses a serious threat to the main source of clean water globally. Nanoparticles have the potential for remediation of polluted aquifers; however, environmental safety concerns associated with in situ deployments of such technology include potential detrimental effects on microorganisms in terms of toxicity and functional disruptions. In this work, we evaluated a new and ecofriendly approach using carbon dots (CDs) as Fenton-like catalysts to catalyse the degradation of dye-containing groundwater samples. This investigation aimed at evaluating the efficacy of a novel remediation technology in terms of dye degradation and toxicity reduction while assessing its impacts on aquatic microorganisms. Uncontaminated Australian groundwater samples were spiked with methylene blue and incubated in the dark, at 18 °C, under slow agitation, using CDs at 0.5 mg mL^-1 and H₂O₂ at 73.5 mM for 25 h. The dye degradation rate was determined as well as the toxicity of the treated solutions using the Microtox® bioassay. Further, to determine the changes in the groundwater microbial community, 16 S rRNA sequencing was used and evenness and diversity indices were analysed using Pielou's evenness and Simpson index, respectively. This study revealed that dye-containing groundwater were effectively treated by CDs showing a degradation rate of 78-82% and a significant 4-fold reduction in the toxicity. Characterisation of the groundwater microbiota revealed a predominance of at least 60% Proteobacteria phylum in all samples where diversity and evenness were maintained throughout the remediation process. The results showed that CDs could be an efficient approach to treat polluted groundwater and potentially have minimum impact on the environmental microbiome.

Enhancing the photocatalytic performance of surface - Treated SnO2 hierarchical nanorods against methylene blue dye under solar irradiation and biological degradation

Surfactant -treated tin oxide (SnO₂) hierarchical nanorods were successfully synthesized through hydrothermal technique. The X-ray diffraction analysis showed the prepared SnO₂ possesses tetragonal rutile structure having appreciable crystallinity with crystallite sizes in the range of 110 nm-120 nm. UV-visible diffuse reflectance absorption spectra confirm that the better visible light absorption band of SnO₂ hierarchical nanorods have red shift compared to the pure SnO₂. Fourier transform infrared spectroscopy (FTIR) study evident that the as-prepared SnO₂ nanorods encompass the characteristic bands of SnO₂ nanostructures. The morphological analyses of prepared materials were performed by FESEM, which shows that hierarchal nanorods and complex nanostructures. EDX analyses disclose all the samples are composed of Sn and O elements. The photocatalytic performance of the prepared surfactant treated SnO₂ hierarchical nanorods was evaluated using methylene blue (MB) dye removal under direct natural sunlight. Recycling experiment results of CTAB - SnO₂ nanorods and photocatalytic reaction mechanism also discussed in detail.

Superparamagnetic hematite spheroids synthesis, characterization, and catalytic activity

The leaf extract of Muntingia calabura is being first reported to be used for the synthesis superparamagnetic hematite nanoparticles by following the green-chemistry approach. Field Emission - Scanning Electron Microscopic image revealed the formation of irregular nano spheroids averaging at 48.57 nm in size and characteristic of Fe and O atoms, as revealed by Energy Dispersive X-Ray spectrum. X-ray diffraction analysis results proved the crystallinity of hematite diffraction planes with crystallite sizes averaging at 30.68 nm. The lattice parameter values stayed concordant with the literature. The superparamagnetic nature was attested by the high value of saturation magnetism (2.20 emu/g) with negligible coercivity and retentivity. Fourier Transform Infrared Spectroscopy results affirmed numerous moieties involved in the synthesis of hematite nanoparticles and the existence of signature Fe-O bands. Thermogravimetric analysis studies portrayed the thermal behavior nanoparticles with 28% weight loss and thermal stability was attained after 700 °C. X-ray photoelectron spectroscopy analysis confirmed the valence states of Fe and O in the hematite nanoparticles and ascertained the purity. The mesoscopic structure was revealed by Brunauer-Emmett-Teller studies with considerable surface area (112.50 m²/g). The Fenton-like catalysis mediated by the nanoparticle sample was demonstrated by degrading methylene blue dye. The remarkable degradation efficiency of 93.44% was obtained and the kinetics was conformed to a second-order model with a high R² value. Therefore, the highly crystalline and mesoporous superparamagnetic hematite spheroids prepared using the leaf extract of M. calabura would find promising applications in various catalysis processes.

Waste-to-Resource: New application of modified mine silicate waste to remove Pb2+ ion and methylene blue dye, adsorption properties, mechanism of action and recycling

Currently, heavy metals and dyes are some of the most critical pollutants in the aquatic environment. So, in this paper "waste-to-resource conversion", as a new application of modified mine silicate waste to remove Pb²⁺ ion and methylene blue (MB) dye, adsorption properties, mechanism of action and recycling were studied. Silicate wastes are located in the alteration zone and the margin of molybdenum ore, these wastes are under the influence of hydrothermal solutions which are impregnated with iron and manganese ions. Hence, acid and base modifications have been commonly used. So, in this study, a highly porous nanostructure of modified silicate waste was used to remove MB and Pb²⁺ ion, in subsequent to our previous study on the application of the raw material of the same in the removal of malachite green. Acid, base, and acid/base treatments were used to activate and modify the adsorbent. Results show a significantly higher potential of modified adsorbent in the removal of MB and Pb²⁺ compared to the raw material. According to the isotherm and kinetic studies for MB and Pb²⁺ the Langmuir and Temkin and pseudo-second-order models were investigated with experimental data. Modified nanomaterial was used for several adsorption and desorption processes, without a significant decrease in the capability of the adsorbent in the removal of MB and Pb²⁺ pollutants. Leached iron and manganese ions (as production of modification) are deposited in the form of sludge using a simple pH adjustment and precipitation process and can be used to recover iron and manganese metals in the long run. The comparison of monolayer adsorption capacity using for Pb²⁺ ion and MB dye are as ((untreated SW: 29.41, 1.05); (NaOH treated: 21.74, 100); (Nitric Acid treated: 16.67, 142.86); (Citric Acid treated: 40, 125); (Nitric/Citric Acids treated: 15.63, 111.11) and (Nitric/Citric Acids/NaOH treated: 15.15, 83.33)), respectively. Higher adsorption capacity and re-generable properties of this adsorbent suggest the usage of this natural and abundant mine waste to treat wastewater containing toxic elements and dyes.

Spectral and structure characterization of Ferula assafoetida fabricated silver nanoparticles and evaluation of its cytotoxic, and photocatalytic competence

This study aims to develop an eco-friendly method for rapidly synthesizing silver nanoparticles (AgNPs) using Asafoetida ethanol extracts and to validate AgNPs synthesis using UV-vis spectroscopy (absorption spectrum), FTIR (functional groups), XRD (crystallinity), FE-SEM (size of the particles) and SEM-EDAX (Purity). Furthermore, to evaluate the anti-proliferative effect of Ag NPs against grown cultured L6 cell lines, studies have shown that AgNPs biosynthesis inhibits cancer cell growth compared to control cell lines. UV-vis absorption verified the existence of Ag NPs, and the spectrum was observed at 480 nm. Functional groups are present in the synthesized Ag NPs were shifted on 528.48 cm^-1 confirmed using an FT-IR spectrum. Consequently, anti-cancer efficacy observed the IC₅₀ value of As Ag NPs against L6 cells was 1.0 μg/mL for 48 h. Finally, using a halogen lamp, studies explored the photocatalytic degradation of AgNPs against the methylene blue radioactive dye and achieved a 96 percent degradation rate in 90 min. Asafoetida mediated silver nanoparticles show grater photodegradation for methylene blue dye, which is present in textile industries, when exposed to solar light, and it has a wide range of potential applications in wastewater treatment. As a whole, biosynthesized silver nanoparticles showed excellent cytotoxic, antioxidant, and photocatalytic dye degradation effects.

Photocatalytic effect of CuO nanoparticles flower-like 3D nanostructures under visible light irradiation with the degradation of methylene blue (MB) dye for environmental application

The present research work focuses on preparing 3D transition metal doped copper oxide nanostructures through sonication method and to investigate the effect of doping different transition metal into copper oxide (CuO) on the basic properties of CuO nanoparticles and, to study the photocatalytic behaviour of the doped CuO samples. The morphological studies performed with the help of SEM revealed the formation of flower like CuO 3D nanostructures for all the doped samples. The slight shift in the position of peaks in the x-ray diffraction (XRD) pattern confirms that doping has been successfully done into CuO. Also, the sharp diffraction peaks suggest the polycrystalline nature of the sample with monoclinic structure. The UV-vis absorption analysis reveals a bandgap of 2.26, 2.12 and 2.15 eV for the CuO samples doped with nickel, zinc, and iron respectively via Tauc plot. The photocatalytic performance of the samples tested through the degradation of methylene blue (MB) dye suggests that samples doped with Zn shows better degradation. Thus, it is evident that the morphology and the optical properties of the CuO can be tailored by doping transition metal into it.

Resin immobilized gold nanocomposites assisted surface enhanced infrared absorption (SEIRA) spectroscopy for improved surface assimilation of methylene blue from aqueous solution

In the present work, we report the adsorption of the methylene blue (MB) dye from an aqueous solution employing resin immobilized gold nanocomposites (R-AuNCs) assisted surface-enhanced infrared absorption (SEIRA) spectroscopy. The appropriate adsorption isotherm models, including the Langmuir, Freundlich, and Temkin are tested to reveal the interactive behavior between the adsorbent (R-AuNCs) and adsorbed (MB). Interestingly, Fourier transform infrared spectroscopy (FTIR) in combination with R-AuNC materials could be another approach through which the analysis of adsorption-desorption of MB on the surface of nanocomposite adsorbents is possible in a more precise way with high sensitivity and adsorptivity. In addition, a 10-fold enhancement of the signal intensity of MB dye was obtained due to the electrostatic interaction and H-bonding interaction between COO^- groups of adsorbent and the positively charged active sites of the dye molecules. The value of % removal efficiency and % adsorption obtained in the present method was 77.64% and 186.61%, respectively. Desorption of MB from adsorbent surface was also carried out using 0.1 M cetylpyridinium chloride as cationic surfactant; resulting process shows for 'n' number of cyclic process. The maximum desorption capacity for MB found in the present investigation was 44.38 mg/g, The advantages of current method are its simplicity, sensitivity, rapidity, ease to fabrication and excellent adsorption efficiencies to remove MB dye from aqueous solution.

A retrospective analysis of 5-year post surgery recurrence of N0 neck and the role of methylene blue in sentinel lymph node biopsy

The aim of this study is to perform a retrospective analysis of the feasibility of the clinical application of SLNB using methylene blue dye (MBD) for the identification of SLN followed by frozen section biopsy to detect occult metastasis in clinically N0 necks. Hence, to know the reliability of MBD in reducing the need for extensive surgery.

Methods

We retrospectively analyzed the clinic pathological data of 48 patients with early oral cancer.The SLN identification rate (IR) was calculated in SLNB with MBD and the false-negative rate (FNR). Intra operative frozen section biopsy was done for all patients was compared with post-operative paraffin histopathology report and the prognosis of patients was analyzed.

Results

Analysis of the 48 SLNB cases showed that there were significant differences in SLN successful detection rate among patients with different site (p = 0.043) and clinical presentation (p = 0.007). Similar significant results (p < 0.05) were observed with intra-operative frozen and post-operative paraffin histopathology sections. SLNs were successfully detected in 37(77.1%) patients out of 48. The intra operative frozen histopathology completely matched with the post-operative paraffin histopathology showing 39 (81.2%) negative and 09 (18.8%) positive cases. A prognostic analysis of SLN detection based on 48 patients showed that the 5-year survival rate was 100%.

Conclusion

MBD has acceptable SLN identification rate and a low FNR(false negative report) in frozen sections. Stained SLNs with no SLN metastasis are associated with disease-free survival (DFS). Hence, MBD-SLN biopsy has significantly reduced the need for extensive neck dissection in N0 neck with less morbidity.

Development of Arabic gum-based AgTiO2 nanocomposite hydrogel as high efficient adsorbent of cationic dye methylene blue from water

The chemically crosslinked silver titanium dioxide embedded Arabic gum grafted polyacrylamide-polyacrylonitrile nanocomposite AgTiO₂@AG-g-P(AM-co-AN)was successfully synthesized and investigated by ATR-IR, XRD, and SEM. The synthesis optimization parameters of AG-g-P(AM-co-AN)were 5% AG, 1/0.5 AM/AN monomer molar ratio, 0.5 mg MBA cross-linker, and AgTiO₂ content (1%) gives AgTiO₂@AG-g-P(AM-co-AN) nanocomposite. While adsorption studies for AgTiO₂@AG-g-P(AM-co-AN) exhabited the maximum adsorption capacity (104.50 ± 3.02 mg/g) at concentration (150 mg/L), MB concentration (15 mg/L) and pH (8.0). The adsorption nonlinear kinetics models were used. Pseudo-second order governs the adsorption process, and the Langmuir model is more suited than Freundlich and Temkin.

Influence of tin (Sn) doping on Co3O4 for enhanced photocatalytic dye degradation

Wastewater remediation is one of the special issues that have been discussed in recent years and one of the main pollutants was dyes which totally changes the water behavior. To eradicate the organic compounds from the wastewater and reuse it, there are numerous steps have been taken into consideration. Dye degradation via photocatalysis is one of the promising technique with good efficiency. Pure and tin (Sn) doped Co₃O₄ was prepared employing co-precipitation technique. The structural, vibrational, optical and morphological analysis was done employing X-ray diffraction studies, Photoluminescence, Raman analysis and Scanning Electron Microscopic (SEM) studies. The well-defined nanoparticles were grown with 1 M Sn doped Co₃O₄. The photocatalytic activities of methylene blue dye under visible light were investigated by adding the samples (CS-1, CS-2, CS-3). 1 M Sn doped Co₃O₄ sample showed 75% efficiency towards dye degradation. The prepared 1 M Sn doped Co₃O₄ sample will be the best for photocatalytic activity. By doping Sn atoms the efficiency of the host is increased which will be the most promising candidate for the photocatalytic dye degradation applications.

Efficacy of Periareolar Versus Peritumoral Injection of TC99-Labelled Sulphur Colloid and Methylene Blue Dye for Detection of Sentinel Lymph Node in Patients with Early Breast Cancer: a Comparative Study

Sentinel lymph node biopsy using dual methods of blue dye and radioactive isotope is what is practised as the standard of care at most of the centres. The combined use of radioactive colloid and blue dye injection is considered the gold standard for axillary sentinel lymph node biopsy in breast cancer with a 97% accuracy rate. The aim of this study is to determine the optimal injection site for methylene blue dye and Tc99-labelled sulphur colloid for sentinel lymph node biopsy in early breast cancer. In both periareolar and peritumoral groups of patients, overall rate of identifying sentinel lymph node (hot, blue and hot and blue nodes) with dual dye was comparable (100% and 96.36%) with p value = 0.475. Also in both groups of patients, overall rate of getting pathological positive sentinel lymph node on final histopathological report was comparable (52.73% and 45.28%) with p value = 0.561. Periareolar versus peritumoral injection of dual dye shows comparable success rates for axillary sentinel lymph node identification and can be considered rapid and reliable method. However, the periareolar route is technically simple and especially privileged in nonpalpable (T0) and upper outer quadrant lesions mainly for the prevention of the shine through phenomenon.

Silver nanoparticles decorated g-C3N4: An efficient SERS substrate for monitoring catalytic reduction and selective Hg2+ions detection

Graphitic carbon nitride supported Ag NPs(AgNPs@g-C₃N₄) were synthesized by an in-situ chemical reduction using a green reducing agent, tannic acid. They were characterized by UV-Vis, FTIR, XPS, XRD, FESEM, EDAX and HRTEM. They were very much SERS sensitive, and capable of detecting methylene blue and 4-aminothiophenol at 1 × 10^-12 M and 1 × 10^-10 M, respectively with the corresponding SERS enhancement factor of 1.4 × 10⁸ and 4.7 × 10⁷. Apart from its high SERS sensitivity, it exhibited high catalytic activity for the reduction of MB with NaBH₄. So, their SERS activity and catalytic activity were combined successfully to monitor catalytic reduction of MB by SERS technique. Further, the SERS activity towards MB was also employed for the detection/quantification of free Hg²⁺ ions in aqueous solution. The SERS intensity of MB drastically decreased in the presence of Hg²⁺ ions, and hence it provides novel route to detect and quantify the latter. Presence of Ca²⁺, Mg²⁺, Cu²⁺ and Cd²⁺ions showed zero interference for it. So, this study proves that Ag NPs@g-C₃N₄ as a unique substrate for multiple SERS applications.

Sentinel Lymph Node Biopsy in Early Breast Cancer Using Methylene Blue Dye Alone: a Safe, Simple, and Cost-Effective Procedure in Resource-Constrained Settings

Sentinel lymph node biopsy (SLNB) is done by different techniques in clinically node-negative patients with early breast cancer. In this study, we aim to estimate the identification rates, positivity rates, cost-effectiveness, and outcomes for patients who underwent sentinel node biopsy using methylene blue dye alone. This was a retrospective review of 172 patients with early breast cancer (cT1-3, N0) who underwent SLNB using methylene blue dye alone between January 2014 and December 2018 including their follow-up details until December 2019. The mean age was 51 ± 10.3 (range: 28 to 76) years. There were 63 (36.6%) patients with cT1 tumor, 108 (62.7%) with cT2, and only 1 patient with cT3 tumor. Breast conservation surgery was performed in 62 (36%) while the remaining 110 (64%) underwent simple mastectomy. Sentinel nodes were successfully identified in 165 (95.9%) with a positivity rate of 23.6%. There was no dye-related adverse reactions intra-operatively. The mean duration of follow-up was 26.68 ± 15.9 months (range: 1-60). Chronic arm pain was present in 7 (4%) while none of the patients had lymphedema or restriction of shoulder joint motion. There were no documented axillary nodal recurrences in this cohort. Eight (4.65%) patients were detected to have systemic metastasis. One patient died of brain metastasis from bilateral breast cancer. The mean disease-free survival was 57 months (95% CI: 55-59). Sentinel lymph node biopsy using methylene dye alone is a safe, simple, and cost-effective alternative to isosulfan blue or radio isotope technique in surgical centers with resource constraints.

Photocatalytic degradation of methylene blue dye in aqueous solution by MnTiO3 nanoparticles under sunlight irradiation

Nanophotocatalyst MnTiO3 powders were synthesized by sol-gel technique and characterized by means of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), as well as their thermal behavior has been studied by differential thermal and thermogravimetric analyses (DTA/TGA). Powders morphology was analyzed by means of Transmission electron microscopy (TEM). Effect of various process parameters like amount of photocatalyst, dye concentration, solution pH and irradiation time on the extent of removal of dye were studied in detail. The photo-degradation was relatively higher using lower amount (0.005 g) of semiconductor, reached rate of 75% and 70% after 240 min for mixed MnTiO3/TiO2 and pure MnTiO3 nanocatalysts. The kinetic model of photocatalytic degradation of MB follows pseudo-first-order kinetic with a high correlation coefficient values (R2 > 0.95). These results underline the use of effective, low-cost and easily available MnTiO3 photocatalyst for the decomposition of pollutants to water under natural sunlight.

Sentinel lymph node biopsy in medullary thyroid microcarcinomas

The aim of this prospective study was to analyze accuracy of sentinel lymph node biopsy with methylene blue dye for intraoperative detection of lateral metastases in clinically N0M0 medullary microcarcinomas with calcitonin <1,000 pg/mL and selection of true-positive patients for one-time therapeutic lateral dissection. In addition to total thyroidectomy and central neck dissection, all patients had bilateral sentinel biopsy of jugulo-carotid regions after methylene blue injection to decide upon necessity for lateral dissection. If sentinels were benign on frozen section, additional non-sentinels were extirpated, with no further lateral dissection. If sentinels were malignant, one-time lateral dissection was performed. 20 patients were included in this study. Hereditary disease form was observed in 3/20 (15%) of patients with RET proto-oncogene mutation C634F; remaining 17/20 (85%) were negative for germline mutations. There were no allergic reactions to methylene blue and identification rate of sentinels was 100%. In total, 2/20 (10%) cN0 patients had lymphonodal metastases, thus were reclassified as pN1b. Remaining 18/20 (90%) were classified pN0 based on standard pathohistology. Frozen section findings on sentinels were 100% match with standard pathohistology, and there were no skip metastases in lateral compartments. Sensitivity, specificity and accuracy of sentinel biopsy method with methylene dye and frozen section were 100%. Dzodic's sentinel lymph node biopsy method can be used for intraoperative assessment of lateral compartments and optimization of initial surgery of medullary microcarcinomas with calcitonin <1,000 pg/mL. This way, cN0 patients with sentinel metastases can receive one-time lateral dissection, and those without benefit from less extensive surgery.

Facile synthesis of Fe2O3 nanoparticles from Egyptian insecticide cans for efficient photocatalytic degradation of methylene blue and crystal violet dyes

In this study, Fe₂O₃ (hematite) nanoparticles with different crystallite sizes (40-59 nm) were synthesized from Egyptian insecticide cans using the combustion method. The organic fuels were urea, glycine, L-alanine, and L-valine. Fe₂O₃ nanoparticles were characterized utilizing different devices such as BET, PL, FT-IR, XRD, HR-TEM, FE-SEM, UV-Vis, and DTG. Crystal violet (CV) and methylene blue (MB) dyes were efficiently removed from aqueous solution by photocatalytic degradation under UV irradiation in the presence of Fe₂O₃ and H₂O₂. The % degradation of 50 mL crystal violet or methylene blue dye (20 mg/L) using 0.1 g Fe₂O₃ in the presence of H₂O₂ was 100% after 30 or 40 min, respectively. Also, the degradation processes are fitted well with the first order model. Besides, the photocatalytic activity of Fe₂O₃ unaltered even after it was reused three times. Hence, the synthesized Fe₂O₃ nanoparticles can be considered a promising and efficient photocatalyst for the degradation of crystal violet and methylene blue dyes.

Investigations on the enhanced dye degradation activity of heterogeneous BiFeO3-GdFeO3 nanocomposite photocatalyst

Perovskite types of nanocomposites of BiFeO₃-GdFeO₃ (BFO-GFO) has been synthesized using sol-gel route for the first time. The nanocomposite powders were characterized by powder X-Ray diffraction (PXRD) to confirm the existence of mixed crystallographic phases. EDX analysis on nanocomposites estimates the composition of individual element present in BFO-GFO matrix. The induced strain upon loading GdFeO₃(GFO) in BiFeO₃ (BFO) matrix has been computed with the aid of Williamson -Hall (W-H) plot. Surface morphologies of nanocomposite powders has been studied using Field Emission Scanning Electron Microscope (FESEM) images. The observed changes in the band gap energies of nanocomposite powders due to the inclusion of GFO has been ascertained from the tauc plots. PL emission of BFO upon loading GFO found to have detected in the IR region due to defect level transition. Finally, the methylene blue dye (MB) degradation characteristics of BFO, GFO and the nanocomposite powders of BFO-GFO have also been studied. The overall results obtained has been discussed in detail.

Allergy-like reactions to methylene blue following laparoscopic chromopertubation: A systematic review of the literature

Methylene blue is commonly used as a tracer in sentinel lymph node mapping for many malignant diseases or chromopertubation during gynecologic laparoscopy. In contrast with other blue dyes such as patent blue V or isosulfan blue, methylene blue rarely causes an allergy-like reaction in patients undergoing sentinel lymph node mapping. However, in chromopertubation, some cases of allergy-like reaction to methylene blue have been reported; these comprise two types: an allergic reaction and methemoglobinemia. In this study, a systematic literature review of allergy-like reactions caused by methylene blue dye following laparoscopic chromopertubation was conducted. A search was conducted in PUBMED, Web of Science, and Scopus from inception until June 2018, using the terms: "methylene blue", "complication", "allergic", "hypersensitive", "lung/pulmonary edema"," methemoglobinemia", "anaphylactic shock", "chromopertubation", "pertubation", "laparoscopic", and "laparoscopy". Ultimately, the eligibility criteria were fulfilled by only 12 case reports. Among 13 cases including our case of severe anaphylactic shock after chromopertubation, allergic reactions were diagnosed in four cases, methemoglobinemia in six, and there was no confirmed diagnosis in three cases; the clinical course consisted of skin changes, blue discoloration of body fluids, respiratory failure, and hemodynamic failure, regardless of the underlying diagnoses. Regarding diagnosis, methemoglobinemia was confirmed with co-oximetry (spectrophotometry). First-line therapy included supportive care for both cases of allergic reactions and methemoglobinemia.

Methylene blue dye removal on silver nanoparticles reduced by Kyllinga brevifolia

Silver nanoparticles (AgNPs) were prepared by reacting Kyllinga brevifolia extract (KBE) with AgNO₃ aqueous solution at room temperature (22 ± 3 °C). The phytochemical constituents in KBE responsible for the reduction process were identified as carbohydrate, protein, and plant sterols (stigmasterol and campesterol). KBE was also found to function as a capping agent for stabilization of AgNPs. The AgNPs were stable at room temperature and had a quasi-spherical shape with an average particle size 22.3 nm. The use of KBE offers not only eco-friendly and non-pathogenic path for AgNPs formation, it also induced rapid formation of the AgNPs. Methylene blue (MB) removal was then done on the AgNPs in the presence of either KBE or NaBH₄. Ninety-three percent removal of MB was achieved with a rate of reaction 0.2663 min^-1 in the solution with KBE+AgNPs (pH 2). However, in NaBH₄+AgNPs system, 100% MB removal was achieved at pH 8-10. The reaction rate was 2.5715 min^-1 indicating a fast removal rate of MB dye. The process of reduction occurs via electron relay effect whereas in KBE+AgNPs system, sedimentation occurred along with the reduction process. Nevertheless, the use of KBE+AgNPs system is preferred as the reducing agent is more benign to the environment.

Intraoperative injection of combined fibrin sealant and methylene blue dye for surgery of branchial cleft cysts: A case report

Differential diagnosis of a lateral neck mass, especially in paediatric patients, should include branchial cleft cysts (BrCC). It is often difficult to identify and completely resect all cystic components, especially when the lesion becomes infected and/or gigantic. Incomplete excision increases the likelihood of recurrences. We reported a simple technique to facilitate the BrCC resection. Tisseel fibrin glue (FG: Baxter AG, Vienna, Austria) was mixed with methylene blue dye in inverse portion to the cyst size and/or the FG volume before injecting into the cystic lumen. After polymerisation of the dyed glue, the lesion was better visualised and extirpated in toto with the aid of the dye colour and gelatinisation by FG. An up-to-date diagnostic and therapeutic algorithm for BrCC was also presented.

Value and best way for detection of Sentinel lymph node in early stage endometrial cancer: Selective lymphadenectomy algorithm

INTRODUCTION

The cornerstone of treatment for endometrial carcinoma is total abdominal hysterectomy and bilateral salpingo-oophoprectomy. Pelvic lymphadenectomy, with or without para-aortic lymphadenectomy, plays an important role in the surgical staging of endometrial carcinoma, and provides more accurate prognostic information.

AIMS

We aimed to evaluate the value and techniques for SLN mapping in early stage endometrial cancer with low risk for lymph node metastasis and whether selective or systematic lymphadenectomy is needed according to the results of proposed algorithm.

METHOD

Between June 2016 and June 2017, 120 patients with early stage endometrial cancer with low risk for nodal metastasis underwent surgical staging. Patients were classified equally according to SLN mapping technique used for injecting the methylene blue dye. Group A included hysteroscopic guided methylene blue injection, Group B included transcervical injection, Group C included subserosal uterine injection and Group D included combined transcervical and subserosal injection. Blue lymph nodes and enlarged suspicious whether stained or non stained ones were dissected for frozen section evaluation done then bilateral pelvic node dissection was done and tissues were sent for pathological examination.

RESULTS

Clinical and pathological SLN detection were more with hysteroscopic technique than others and pathological detection was lower than clinical detection in all techniques. Metastatic disease was more common in nodes with suspicious appearance. About 10% of negative suspicious and mapped nodes were associated with positive other nodes for metastasis.

CONCLUSION

SLN in endometrial cancer has a role in staging of endometrial cancer with best technique for detection, hysteroscopic guided blue dye injection. SLN can be used in patients with low risk for lymph node metastasis for selective lymphadenectomy. Blue dye labelling using methylene blue dye is good in low resource countries as it is cheap. We recommended the following algorithm for surgical staging in early endometrial cancer with better results than using SLN alone. Stage I type 1, grade 1,2 endometrial cancer should undergo surgical staging with initial evaluation of the peritoneum which if affected, it is stage III with no need for lymphadenectomy. Then, dissection of the blue and suspicious nodes which if any is positive on frozen section, selective same side pelvic and paraaortic nodal dissection should be done. If they are negative, no need for lymphadenectomy. This approach can help patients to avoid the side effects associated with a complete lymphadenectomy. The higher rate of detection using this algorithm is related to combining the suspicions nodes with the stained ones.

Radiation grafting: A voyage from bio-waste corn husk to an efficient thermostable adsorbent

The initiator free environmentally benign gamma radiation is employed to graft poly-acrylic acid (PAA) onto the widely produced bio-waste corn husk to develop promising, cheap, efficient and reusable adsorbent (AAc-g-husk) having specific adsorption capacity of 1682.7mgg^-1 of methylene blue (MB) at pH 9.0 and 320K. The most suitable grafting yield is found by optimizing absorbed dose, dose rate and concentrations of monomer, Mohr's salt and inorganic acid. The inter-planar hydrogen bonding among (002) planes of cellulose in the husk decreases after diversifying grafting of PAA on ad-axial, ribs and micro-fibrils surfaces of the corn husks. The chemically and structurally modified AAc-g-husk shows superior thermal stability. The mechanism of MB dye adsorption by AAc-g-husk has been discussed through six two-parameters adsorption isotherm and ten three-parameters adsorption isotherm models at three different temperatures (300, 310 and 320K), seven kinetic models at room temperature, FT-IR and desorption studies in different solvent compositions.

A novel method in decision making for the diagnosis of anterior urethral stricture: using methylene blue dye

Objective

The use of methylene blue dye (MB) to highlight anatomical structures in urology has been well-established. Urethral stricture may extend about a centimeter beyond the abnormal area seen on urethrogram. Although the current literature suggests a tension-free and end- to- end anastomosis after excision of the strictured urethral segment with spongiofibrosis and surrounding corpus spongiosum in short bulbar strictures, some centers dealing with urethroplasty prefer anastomosis for short bulbar strictures while others prefer augmentation. With this study, use of MB for delineating stricture line and assessing spongiofibrosis in the diagnosis of urethral stricture was evaluated.

Material and methods

Five cc MB including 10 mg/mL is diluted with 10 cc saline. In the first scenario, MB is gently injected into urethra via the meatus before the urethroplasty procedure. Meanwhile, the extent of urethral segment stained by MB is noted. In the second scenario (MB spongiosography) in short bulbar stricture, insulin needles are inserted in spongiosa of the stricture site distally and proximally. MB is gently injected with distal needle. The two remaining needles are then observed. Presence of MB efflux in proximal needle implies deficiency of significant spongiofibrosis, so buccal augmentation is performed. Absence of efflux of MB implies significant spongiofibrosis and anastomotik site excised.

Results

Four hundred and ninety-two consecutive cases prospectively evaluated between 2010 and 2014. Precise staining of stricture was successfully observed in 464 (94%) patients. Grossly normal appearing urothelium remained pink. Histopathology confirmed that the stained urethra had a stricture. Of the 22 short bulbar idiopathic strictures, in 18 (82%) MB was seen across the stricture and urethral transection was avoided. Anastomosis was performed in 4 (18%) cases where no MB went across the primary excision. There were no known allergic complications.

Conclusion

MB aids in delineating the urethral lumen and exact site of stricture that needs augmentation. MB Spongiography in short bulbar strictures could be used as a beneficial guide in relation to the type of urethral repair to be performed in terms of augmentation versus excision and anastomosis.

Evaluation of photodynamic therapy in treatment of oral erosive lichen planus in comparison with topically applied corticosteroids

BACKGROUND

The treatment of erosive oral lichen planus represents a therapeutic challenge. Despite numerous existing remedies, some of these treatments display disappointing results. Since it is a chronic disease with no current cure, the best treatment should target mainly the reduction of the duration and severity of symptomatic outbreaks with minimal side effects. To date, corticosteroids remain the first choice of treatment for oral lichen planus (OLP) patients. Although, topical corticosteroids have been found to be the safest and the most successful agents in the treatment of OLP, their prolonged use may cause mucosal problems and may lead to systemic complications. Recently, the use of photodynamic therapy has been well introduced in the treatment of oral diseases. Our clinical study was done to evaluate clinically the effect of photodynamic therapy mediated by methylene blue (MB-PDT) on signs and symptoms of erosive oral lichen planus (EOLP) lesions in comparison with the conventional topical corticosteroids (TC) treatment. The present work tried this recent modality of treatment to overcome the disadvantages of TC.

MATERIAL AND METHODS

Twenty patients with clinical and histological diagnosis of EOLP were selected from Oral Medicine and periodontology department in Faculty of Dentistry, Alexandria University in a randomized parallel study design. They were divided into two groups; group A (control group) involved ten patients who were instructed to use the conventional TC (kenakort A-orabase). While, group B (study group) contained ten patients who received PDT using diode laser 660nm mediated by methylene blue (MB).

RESULTS

Both groups presented statistically significant difference from baseline to follow up periods. But, the MB-PDT in treatment of EOLP showed more remarkable reduction in pain and lesion scores in comparison with corticosteroids treatment.

CONCLUSION

The results of this study allow the conclusion that the MB-PDT is considered to be a better treatment for OELP in comparison with TC because it is much more effective in pain reduction and lesion regression.

The predictive value of methylene blue dye as a single technique in breast cancer sentinel node biopsy: a study from Dharmais Cancer Hospital

Background

Axillary lymph node dissection (ALND) has been the standard treatment of breast cancer axillary staging in Indonesia. The limited facilities of radioisotope tracer and isosulfan or patent blue dye (PBD) have been the major obstacles to perform sentinel node biopsy (SNB) in our country. We studied the application of 1% methylene blue dye (MBD) alone for SNB to overcome the problem.

Methods

This prospective study enrolled 108 patients with suspicious malignant lesions or breast cancer stages I–III. SNB was performed using 2–5 cc of 1% MBD and proceeded with ALND. The histopathology results of sentinel nodes (SNs) were compared with axillary lymph nodes (ALNs) for diagnostic value assessments.

Results

There were 96 patients with invasive carcinoma from July 2012 to September 2014 who were included in the final analysis. The median age was 50 (25–69) years, and the median pathological tumor size was 3 cm (1–10). Identification rate of SNs was 91.7%, and the median number of the identified SNs was 2 (1–8). Sentinel node metastasis was found in 53.4% cases and 89.4% of them were macrometastases. The negative predictive value (NPV) of SNs to predict axillary metastasis was 90% (95% CI, 81–99%). There were no anaphylactic reactions, but we found 2 cases with skin necrosis.

Conclusions

The application of 1% MBD as a single technique in breast cancer SNB has favorable identification rates and predictive values. It can be used for axillary staging, but nevertheless the technique should be applied with attention to the tumor size and grade to avoid false negative results.

Study of CFU for individual microorganisms in mixed cultures with a known ratio using MBRT

Determination of metabolically active cell count is an important step in designing, operating and controlling fermentation processes. It's particularly relevant in processes involving mixed cultures, where multiple species contribute to the total growth. The motivation for the current study is to develop a methodology to estimate metabolically active cell counts for the individual species in a mixed culture with approximate equal numbers. Further, the methodology should indicate the presence of a contaminant in short time periods since in the agar plate methods used frequently it takes about 24 h. We present a methodology based on the rate of Methylene blue (MB) reduction to evaluate total count of metabolically active cells. The standard curve relating the slope of MB reduction and CFU of the individual species could be used to measure the metabolic activity of each species in the mixed culture. The slope of MB reduction could also be used to obtain the growth rate of individual species in a mixed culture and that of the total cell count. These measurements were achieved in less than 6 minutes during the growth of the cells. Evaluating the metabolic activity of individual species in a mixed culture is tedious, difficult and time consuming. The Methylene Blue dye Reduction Test (MBRT) presented here is capable of quickly estimating colony forming units (CFU) of individual species in a mixed culture if the ratio of the numbers of cells is known. The method was used to dynamically detect the occurrence of a contaminating microorganism during fermentation. The protocol developed here can be adapted to applications in processes involving mixed cultures.

A rapid paper chromatographic method for detection of anionic detergent in milk

A paper chromatographic method for the detection of adulteration of anionic detergent in milk is described. The method is based on the complexing of anionic detergent with methylene blue dye and separation of complex from free dye using simple paper chromatographic method. Since complexing of detergent is with dye, visualization is direct without involvement of subsequent detection of complex. The method is simple and results are available in 10 min. The method is sensitive to detect 0.1 % (w/v) labolene (laboratory grade detergent) or 0.01 % (w/v) sodium dodecylbenzene sulfonate (pure anionic detergent) in milk. The method can be adopted at quality control laboratories in dairies for ascertaining the quality of milk.

Sentinel lymphnode biopsy in early breast cancer using methylene blue dye and radioactive sulphur colloid - a single institution Indian experience

BACKGROUND

Axillary lymph node dissection is an established procedure in breast cancer staging. However, it is associated with unpleasant side effects. A promising alternative to assess axillary lymph node status in early breast cancer patients is Sentinel Lymph Node Biopsy (SLNB). Isosulfan blue has traditionally been the dye used to identify the Sentinel Lymph Node (SLN). This article is a validation study of SLNB using methylene blue dye and radioactive sulphur colloid in early breast cancer Indian patients. MATERIALS #ENTITYSTARTX00026;

METHODS

With written informed consent, 100 patients with cytology or biospy proven carcinoma breast, clinical stage T1/ T2 N0 M0, underwent SLNB using combination of methylene blue dye & radioactive technetium 99m sulphur colloid as a part of validation study from June 2003 to February 2006. After validation study, from March 2006 to February 2007, 35 patients have undergone SLNB followed by complete axillary clearance in only those patients with SLNB being positive for metastases.

RESULTS

In all 100 patients of the validation study SLN was identified. Total number of cases with positive axillary nodes was 27, out of which SLN was only positive node for metastases in 69% of cases. The overall sensitivity, specificity, positive predictive valve and negative predictive valve of SLNB 96.2%, 100%, 100% and 98.6% respectively with false negative rate of 3.7%. In subsequent 35 patients who underwent SLNB followed by complete axillary clearance, SLNs was identified in all the cases.

CONCLUSIONS

SLNB is effective in early breast cancer patients of Indian population. SLNB using combination of methylene blue dye and radio-active Tc99m sulphur colloid can stage the axilla with high accuracy & low risk of false negativity in early breast cancer patients.