Depigmentation of Melanin-containing Tissues Using Hypochlorous Acid to Enhance Hematoxylin-eosin and Immunohistochemical Staining.

Pathologists diagnose diseases by observing the histologic and cellular morphology microscopically. However, the high pigmentation in melanin-containing tumors can hide the tumor cell structures, making diagnosing challenging. Previously, hydrogen peroxide and potassium permanganate were utilized for melanin bleaching with several limitations. For instance, hydrogen peroxide has a weak bleaching ability, and the process is time-consuming (12 h). Meanwhile, potassium permanganate affects the antigenicity of antigens and is unsuitable for immunohistochemical (IHC) staining. In this study, the hypochlorous acid (HClO) solution was applied to hematoxylin-eosin and IHC staining of melanin tissue sections. The study discovered that 1% HClO could completely bleach melanin particles in tumor tissues in a short period (19.95 ± 2.53 min) without compromising the hematoxylin-eosin staining. In addition, 2% HClO was utilized for bleaching at room temperature for 61.17 ± 4.32 minutes after the tissue was incubated with 3,3'-diaminobenzidine in IHC staining. This treatment effectively removed melanin without negatively impacting 3,3'-diaminobenzidine signal expression, thus ensuring that the sections met the necessary diagnostic requirements. Therefore, this method could facilitate pathologists in disease diagnosis of melanin-containing tissues.

Construction of hematoxylin-eosin, immunohistochemistry, and EBER-ISH methodology after trichloroisocyanuric acid treatment in melanin-containing tissues.

This study investigated the effects of trichloroisocyanuric acid (TCCA) on the bleaching and morphology of melanin-containing pathological sections. The pathological sections of 27 patients with high melanin content were bleached with 0.5% potassium permanganate, 10% hydrogen peroxide, and different concentrations of TCCA. Significant differences were found among the blank control group, 1% TCCA group (P < 0.0001). The hematoxylin-eosin (HE) score of the "recovery pH" HE staining group after treatment with 1% TCCA was similar to that of the "Conventional HE" scheme group (P > 0.05). The morphological diagnostic scores of 50 cases of pathological sections with different melanin content before and after TCCA bleaching were compared. The results showed a significant difference in the diagnostic score between the middle- and high-melanin content groups before and after 1% TCCA bleaching (P < 0.05). Immunohistochemical staining was performed on meningeal melanoma tissue. For this, 8% TCCA solution was used to remove melanin after Ki67, S100, and ß-catenin immunohistochemical staining. After bleaching with TCCA, the staining and positioning of each marker with different localization were accurate and the background was clear. The same results were also shown with EBER-ISH. This study concluded that 1% TCCA could be used for HE staining of pathological sections containing melanin, and "restore pH" HE scheme as the staining method after TCCA melanin removal. Further, 8% TCCA was used for bleaching after immunohistochemical DAB staining. Melanin can be completely removed, and sections can meet diagnostic needs.

Stopped-flow chemiluminescence determination of the anticancer drug capecitabine: Application in pharmaceutical analysis and drug-delivery systems.

Capecitabine is a chemotherapeutic agent used for the treatment of patients with metastatic cancers. This study aimed at determining the drug capecitabine in a simple chemiluminescence (CL) system of acidic potassium permanganate using the stopped-flow injection technique. Statistical methods were used to detect optimum conditions. The method showed two linear calibration ranges from 6.7 × 10-6 to 6.7 × 10-5 mol L-1 and from 6.7 × 10-5 to 2.7 × 10-3 mol L-1 with a detection limit of 1.5 × 10-6 mol L-1 . Chitosan-modified magnetic nanoparticles were studied in the drug-delivery experiments. According to the pH sensitivity of chitosan and low pH values in tumour cells, the chitosan-coated magnetic nanoparticles could provide a good targeting drug-delivery system to tumour sites. To evaluate the applicability of the method, the capecitabine-loaded magnetic chitosan nanoparticles were synthesized with two different cross-linkers; loading and releasing rates of the drug were investigated using the proposed CL method and an ultraviolet-visible light spectrophotometric method (absorption at 305 nm). The results showed a good correlation between the two methods, and it was found that the synthesized chitosan-modified magnetic nanoparticles could be used for pH-dependent release of capecitabine in cancer cells. Moreover, determination of capecitabine in tablets and synthetic samples was performed.

Single-step formulation of levodopa-based nanotheranostics - strategy for ultra-sensitive high longitudinal relaxivity MRI guided switchable therapeutics.

Nanotheranostics (combined diagnosis and therapy) is emerging as an integral part of future therapeutic strategies. However, the development and fabrication of a nanotheranostic module involves multistep processes and always faces formulation challenges. The complexity involved in its multi-step formulations hinders its reproducible industrial production and clinical translation. Therefore, a facile synthesis of multifunctional nanotheranostics is critical to its translational success. In this report, we have developed a one-pot facile strategy to prepare a MRI-visible photothermal theranostic switchable module (T-SWITCH). These nanoparticles are synthesized through polymerization of levodopa together with the reduction of KMnO4 in the presence of silk sericin for the formation of manganese dioxide particles within the T-SWITCH. The synthesized T-SWITCH showed a uniform size distribution of around 95.77 nm and high longitudinal relaxivity coefficient (r1) of up to 61.94 mM-1 s-1. The reported r1 of the T-SWITCH is exceedingly higher than that of any other previously reported manganese-based contrast agents with first-rate in vitro and in vivo contrast enhancement capability. The T-SWITCH can be activated to switch its therapeutic mode using near-infrared (NIR) light. It exhibited strong excitable absorption in the safer and biological NIR window between 650 and 900 nm. We have validated the significant anti-cancer therapeutic efficacy of T-SWITCH both in vitro and in vivo through switchable photothermal therapy.

An Improved Ion Chromatographic Method for Fast and Sensitive Determination of Hexavalent Chromium and Total Chromium Using Conductivity Detection.

Chromium exists in its two stable oxidation states including trivalent chromium (Cr (III)) and hexavalent chromium (Cr (VI)) in natural waters. Chromium is an essential micronutrient in the trivalent form; however, the hexavalent form of chromium is considered to be a carcinogen. It is important to determine the chromium content along with speciation. There are a number of methods available for chromium determination. Speciation of chromium is essential to know the exact composition of chromium. Ion exchange chromatography is one of the techniques used to determine Cr (VI). The proposed method can be used to perform the speciation of Cr (III) and Cr (VI). It is a two-step process: first Cr (VI) is determined, followed by total chromium determination by treating the sample with potassium permanganate solution to oxidize the Cr (III) present in the sample to Cr (VI) and determining it as Cr (VI). Conductivity detector is used for the detection. Addition of potassium permanganate solution to the ground water samples for oxidizing the Cr (III) to Cr (VI) is the newly adopted sample preparation technique. The effect of potassium permanganate oxidation is studied in detail in the proposed method. This method can be used for chromium speciation in river water and ground water samples.

Spontaneous reduction of KMnO4 with MoS2 quantum dots for glutathione sensing in tumors.

Transition-metal dichalcogenides (TMDCs) have attracted a lot of attention due to their electronic, optical, mechanical, and catalytic properties. In addition, TMDCs possess rich redox chemistry that enables the decoration of metal nanoparticles directly on their surfaces. In this paper, MnO2/MoS2 nanocomplexes were obtained by the spontaneous reduction of KMnO4 with MoS2 QDs as the reductive agent. The formed MnO2/MoS2 nanocomplexes exhibited activated fluorescence and MR imaging signal in the presence of glutathione (GSH). After conjugation with an AS1411 aptamer, specific in vivo MR imaging and fluorescence labeling of the 786-O tumor cells were realized, showing their promising potential for biomedical applications.

Fluorometric determination of antioxidant capacity in human plasma by using upconversion nanoparticles and an inner filter effect mechanism.

The balance between free oxygen radicals and antioxidant defense systems is usually assessed by an antioxidant capacity assay. A rapid and sensitive antioxidant capacity assay is described here. It is making use of NaYF4:Yb/Er@NaYF4 core-shell upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4). In this strategy, added KMnO4 reduces the green (540 nm) emission of the UCNPs (under 980 nm photoexcitation) due to an inner filter effect. The antioxidants cysteine, ascorbic acid and glutathione (GSH) reduce the intense purple color of KMnO4 because it is reduced to Mn(II) ion. Hence, the green upconversion fluorescence is restored after the addition of antioxidants. Figures of merit for this assay (for the case of GSH) include a detection limit of 3.3 µM, a detection range that extends from 10 µM to 2.5 mM, and an assay time of a few seconds. The assay was applied to the evaluation of antioxidant capacity in human plasma samples spiked with GSH and gave satisfactory repeatability and specificity. Graphical abstract Schematic presentation of a fluorometric assay based on inner filter effect (IFE) between upconversion nanoparticles (UCNPs) and potassium permanganate (KMnO4) for the determination of antioxidant capacity in human plasma.

A high throughput method for total alcohol determination in fermentation broths.

BACKGROUND: The potassium dichromate oxidation method used in determination of alcohols in fermentation has two major disadvantages. This method cannot be used to determine alcohols in raw fermentation broth samples, which often contain various reducing sugars. The method is not environment friendly due to the carcinogenicity of Cr (VI) used. RESULTS: A new method for determination of reducing sugars and total alcohols in raw fermentation broths was developed. The fermentation broth was pretreated to remove proteins, polysaccharides, glycerol and organic acids. The colorimetric change from both total alcohols and reducing sugars by potassium permanganate oxidation was measured. The portion of colorimetric change from oxidation of reducing sugars was determined by DNS test and subtracted. The remaining portion of colorimetric change was then used to calculate the total alcohol concentration in the sample. CONCLUSIONS: Using this method, total alcohol concentration can be easily and accurately determined in both distilled samples and raw fermentation broth samples. It is fast and environmental friendly.

Characterization and adsorption capacity of potassium permanganate used to modify activated carbon filter media for indoor formaldehyde removal.

This study examined the effect of potassium permanganate (KMnO4)-modified activated carbon for formaldehyde removal under different face velocities and different initial formaldehyde concentrations in building environment. We chose the coconut shell activated carbon due to their high density and purity. Moreover, they have a clear environmental advantage over coal-based carbons, particularly in terms of acidification potential. The chemical properties were characterized by FTIR to show the functional groups, EDS to calculate each component of their energy bands to know how the ratio is. Also, the morphology of the surface was examined with scanning electron microscopy (SEM). The BET determines specific surface area, pore size, and pore volume. It was found that where the initial formaldehyde concentration and the face velocity are low, adsorption capacity is high. The adsorption isotherms of formaldehyde on modified activated carbon are well fitted by both Langmuir and Freundlich equations. The rate parameter for the pseudo-first-order model, pseudo-second-order model, and intraparticle diffusion model was compared. The correlation coefficient of pseudo-second-order kinetic model (0.999 > R2 > 0.9548) is higher than the coefficient of pseudo-first-order kinetic model (0.5785 < R2 < 0.8755) and intraparticle diffusion model (0.9752 < R2 < 0.9898). Thus, pseudo-second-order kinetic model is more apposite to discuss the adsorption kinetic in this test, and the overall rate of the modified activated carbon adsorption process appears to be influenced by more than one step that is both the intraparticle diffusion model and membrane diffusion.

Chemiluminescence of copper nanoclusters and its application for trihexyphenidyl hydrochloride detection.

Chemiluminescence (CL) of copper nanoclusters (CuNCs) induced by cerium (IV) (Ce(IV)) or potassium permanganate (KMnO4 ) in acidic medium was observed. The potential application of CuNCs CL in analytical chemistry was also demonstrated using trihexyphenidyl hydrochloride (THP) as an example based on its enhancing CL intensity for the CuNCs-Ce(IV)/KMnO4 systems. The excited state of the CuNCs acted as a luminophore in the CuNCs-Ce(IV) system, while CuNCs played the role of reductant in the CuNCs-KMnO4 system. The increased CL intensity for Ce(IV)-CuNCs system was proportional to the THP concentrations in the range of 0.1 to 10.0 µM. The detection limit was 49.0 nM and the relative standard deviation was 2.2% for 2.0 µM THP (n = 11). The proposed method was applied to detect THP in pharmaceutical formulations and human plasma samples.

Absorption of Ethylene on Membranes Containing Potassium Permanganate Loaded into Alumina-Nanoparticle-Incorporated Alumina/Carbon Nanofibers.

Ethylene is a natural aging hormone in plants, and controlling its concentration has long been a subject of research aimed at reducing wastage during packaging, transport, and storage. We report on packaging membranes, produced by electrospinning, that act as efficient carriers for potassium permanganate (PPM), a widely used ethylene oxidant. PPM salt loaded on membranes composed of alumina nanofibers incorporating alumina nanoparticles outperform other absorber systems and oxidize up to 73% of ethylene within 25 min. Membrane absorption of ethylene generated by avocados was totally quenched in 21 h, and a nearly zero ethylene concentration was observed for more than 5 days. By comparison, the control experiments exhibited a concentration of 53% of the initial value after 21 h and 31% on day 5. A high surface area of the alumina nanofiber membranes provides high capacity for ethylene absorption over a long period of time. In combination with other properties, such as planar form, flexibility, ease of handling, and lightweight, these membranes are a highly desirable component of packaging materials engineered to enhance product lifetime.

Enhancing the chemiluminescence intensity of a KMnO4 formaldehyde system for estimating the total phenolic content in honey samples using a novel nanodroplet mixing approach in a microfluidics platform.

A novel mixing approach was utilized with a highly sensitive chemiluminescence (CL) method to determine the total phenolic content (TPC) in honey samples using an acidic potassium permanganate-formaldehyde system. The mixing approach was based on exploiting the mixing efficiency of nanodroplets generated in a microfluidic platform. Careful optimization of the instrument setup and various experimental conditions were employed to obtain excellent sensitivity. The mixing efficiency of the droplets was compared with the CL signal intensity obtained using the common serpentine chip design, with both approaches using at a total flow rate of 15 µl min-1 ; the results showed that the nanodroplets provided 600% higher CL signal intensity at this low flow rate. Using the optimum conditions, calibration equations, limits of detection (LOD) and limits of quantification (LOQ) for gallic acid (GA), caffeic acid (CA), kaempferol (KAM), quercetin (QRC) and catechin (CAT) were obtained. The LOD ranged from 6.2 ppb for CA to 11.0 ppb for QRC. Finally, the method was applied for the determination of TPC in several local and commercial honey samples.

A colorimetric sensor array based on sulfuric acid assisted KMnO4 fading for the detection and identification of pesticides.

Pesticides play a critical role in improving crop yield in modern agriculture, but their residues significantly harm the environment and human health. Herein, a novel and simple colorimetric sensor array built on sulfuric acid assisted KMnO4 fading strategy has been developed for pesticides detection and discrimination. This sensor array is facilely fabricated by KMnO4 and sulfuric acid through simply adjusting their concentrations and ratios. Hierarchical clustering analysis (HCA) demonstrates that the as-fabricated colorimetric sensor array has a high dimensionality, and shows excellent capability to recognize common kinds of pesticides from potential interferants. Semi-quantitative detection was achieved through combining HCA and corresponding fitting curves. Moreover, the proposed sensor array was successfully applied to detect pesticide residues (e.g. carbaryl) in real samples. The strategy described herein will not only "maximally" simplify the design and fabrication approach, but expand the application fields of colorimetric sensor array methodology towards weak-reactive analytes.

Investigating the sorption behavior of cadmium from aqueous solution by potassium permanganate-modified biochar: quantify mechanism and evaluate the modification method.

In this work, a KMnO4-modified-biochar-based composite material with manganese oxide produced at 600 °C was fabricated to investigate the sorption mechanism of Cd(II) and to comprehensively evaluate the effect of the modification on biochar properties. Cd(II) adsorption mechanisms were mainly controlled by interaction with minerals, complexation with oxygen-containing functional groups, and cation-π interaction. The sorption capacity was significantly reduced after a deash treatment of biochar, almost shrunk by 3 and 3.5 times for pristine biochar (PBC) and modified biochar (MBC). For deashed PBC, oxygen-containing functional groups were the main contributor toward Cd(II) adsorption while interaction with minerals was significantly compromised and became negligible. The sorption capacity was also apparently decreased after the deash treatment of MBC; however, for deashed MBC, interaction with minerals still was the main contributor to the sorption ability, which could be attributed to the mechanism of interaction of Cd(II) with loaded MnOx on biochar. Cation-π interaction in MBC was notably enhanced compared to PBC due to the oxidation of KMnO4 on biomass. Also, sorption performance by oxygen-containing functional groups was also enhanced. Hence, the modification by KMnO4 has a significant effect on the Cd(II) sorption performance of biochar.

Remediation of arsenic(III) from aqueous solutions using zero-valent iron (ZVI) combined with potassium permanganate and ferrous ions.

A system of zerovalent iron combined with potassium permanganate and ferrous irons (Fe(II)-KMnO4-ZVI) was used to remove As(III), one of the most poisonous wastewater pollutants. The Fe(II)-KMnO4-ZVI system was characterized by using X-ray photoelectron spectroscopy and scanning electron microscopy. The As(III) removal efficiency by the Fe(II)-KMnO4-ZVI system under different conditions was investigated and the experimental data were fitted to adsorption kinetics and isotherm models. As(III) could be removed by both physisorption and chemisorption through mixing adsorbents in a very short time (minute scale) with high removal ratios (more than 99.5%) over a wide range of pH (1-9) and concentration (20-100 mg/L). The removal of As(III) by the Fe(II)-KMnO4-ZVI system agreed well with pseudo-first-order reaction kinetics and pseudo-second-order reaction kinetics. The Freundlich isotherm provided a good model of the adsorption system, indicating that the Fe(II)-KMnO4-ZVI system has heterogeneous structure. The results show that the Fe(II)-KMnO4-ZVI system exhibited a high removal efficiency for As(III), which suggested that it might be an effective material for As(III) remediation.

Antioxidative Categorization of Twenty Amino Acids Based on Experimental Evaluation.

In view of the great importance bestowed on amino acids as antioxidants in oxidation resistance, we attempted two common redox titration methods in this report, including micro-potassium permanganate titration and iodometric titration, to measure the antioxidative capacity of 20 amino acids, which are the construction units of proteins in living organisms. Based on the relative intensities of the antioxidative capacity, we further conducted a quantitative comparison and found out that the product of experimental values obtained from the two methods was proven to be a better indicator for evaluating the relative antioxidative capacity of amino acids. The experimental results were largely in accordance with structural analysis made on amino acids. On the whole, the 20 amino acids concerned could be divided into two categories according to their antioxidative capacity. Seven amino acids, including tryptophan, methionine, histidine, lysine, cysteine, arginine and tyrosine, were greater in total antioxidative capacity compared with the other 13 amino acids.

Novel sequential process for enhanced dye synergistic degradation based on nano zero-valent iron and potassium permanganate.

A novel synergistic technology based on nano zero-valent iron (NZVI) and potassium permanganate (KMnO4) was developed for treatment of dye wastewater. The synergistic technology was significantly superior, where above 99% of methylene blue (MB) was removed, comparatively, removal efficiencies of MB with the sole technology of NZVI and KMnO4 at pH 6.39 being 52.9% and 63.1%, respectively. The advantages of this technology include (1) the in situ formed materials (manganese (hydr)oxides, iron hydroxides and MnFe oxide), resulting in the stable and high removal efficiency of MB and (2) high removal capacity in a wide range of pH value. Compared with simultaneous addition system of NZVI and KMnO4, MB removal was remarkably improved by sequential addition system, especially when KMnO4 addition time was optimized at 20 min. Analyses of crystal structure (XRD), morphological difference (FE-SEM), element valence and chemical groups (XPS) of NZVI before and after reaction had confirmed the formation of in situ materials, which obviously enhanced removal of MB by oxidation and adsorption. More importantly, the roles of in situ formed materials and degradation mechanism were innovatively investigated, and the results suggested that NCH3 bond of MB molecule was attacked by oxidants (KMnO4 and in situ manganese (hydr)oxides) at position C1 and C9, resulting in cleavage of chromophore. This study provides new insights about an applicable technology for treatment of dye wastewater.

Flow-injection chemiluminescence analysis for sensitive determination of atenolol using cadmium sulfide quantum dots.

A sensitive, rapid and simple flow-injection chemiluminescence (CL) system based on the light emitted from KMnO4-cadmium sulfide quantum dots (CdS QDs) reaction in the presence of cetyltrimethylammonium bromide (CTAB) in acidic medium was developed as a CL probe for the sensitive determination of atenolol. Optical and structural features of CdS QDs capped with l-cysteine, which synthesized via hydrothermal approach, were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL), and UV-Vis spectroscopy. The CL intensity of KMnO4-CdS QDs-CTAB was remarkably enhanced in the presence of trace level of atenolol. Under optimum experimental conditions, there is a linear relationship between the increase in CL intensity of KMnO4-CdS QDs-CTAB system and atenolol concentration in a range of 0.001 to 4.0 mg L(-1) and 4.0 to 18.0 mg L(-1), with a detection limit (3σ) of 0.0010 mg L(-1). A possible mechanism for KMnO4-CdS QDs-CTAB-atenolol CL reaction is proposed. To prove the practical application of the KMnO4-CdS QDs-CTAB CL method, the method was applied for the determination of atenolol in spiked environmental water samples and commercial pharmaceutical formulation. Furthermore, corona discharge ionization ion mobility spectrometry (CD-IMS) technique was utilized for determination of atenolol.

Acidic Potassium Permanganate Chemiluminescence for the Determination of Antioxidant Potential in Three Cultivars of Ocimum basilicum.

Ocimum basilicum, a member of the family Lamiaceae, is a rich source of polyphenolics that have antioxidant properties. The present study describes the development and application of an online HPLC-coupled acidic potassium permanganate chemiluminescence assay for the qualitative and quantitative assessment of antioxidants in three cultivars of O. basilicum grown under greenhouse conditions. The chemiluminescence based assay was found to be a sensitive and efficient method for assessment of total and individual compound antioxidant potential. Leaves, flowers and roots were found to be rich reserves of the antioxidant compounds which showed intense chemiluminescence signals. The polyphenolics such as rosmarinic, chicoric, caffeic, p-coumaric, m-coumaric and ferulic acids showed antioxidant activity. Further, rosmarinic acid was found to be the major antioxidant component in water-ethanol extracts. The highest levels of rosmarinic acid was found in the leaves and roots of cultivars "holy green" (14.37; 11.52 mM/100 g DW respectively) followed by "red rubin" (10.02; 10.75 mM/100 g DW respectively) and "subja" (6.59; 4.97 mM/100 g DW respectively). The sensitivity, efficiency and ease of use of the chemiluminescence based assay should now be considered for its use as a primary method for the identification and quantification of antioxidants in plant extracts.

Simple combination of oxidants with zero-valent-iron (ZVI) achieved very rapid and highly efficient removal of heavy metals from water.

This study, for the first time, demonstrated a continuously accelerated Fe(0) corrosion driven by common oxidants (i.e., NaClO, KMnO4 or H2O2) and thereby the rapid and efficient removal of heavy metals (HMs) by zero-valent iron (ZVI) under the experimental conditions of jar tests and column running. ZVI simply coupled with NaClO, KMnO4 or H2O2 (0.5 mM) resulted in almost complete As(V) removal within only 10 min with 1000 µg/L of initial As(V) at initial pH of 7.5(±0.1) and liquid solid ratio of 200:1. Simultaneous removal of 200 µg/L of initial Cd(II) and Hg(II) to 2.4-4.4 µg/L for Cd(II) and to 4.0-5.0 µg/L for Hg(II) were achieved within 30 min. No deterioration of HM removal was observed during the ten recycles of jar tests. The ZVI columns activated by 0.1 mM of oxidants had stably treated 40,200 (NaClO), 20,295 (KMnO4) and 40,200 (H2O2) bed volumes (BV) of HM-contaminated drinking water, but with no any indication of As breakthrough (<10 µg/L) even at short empty bed contact time (EBCT) of 8.0 min. The high efficiency of HMs removal from both the jar tests and column running implied a continuous and stable activation (overcoming of iron passivation) of Fe(0) surface by the oxidants. Via the proper increase in oxidant dosing, the ZVI/oxidant combination was applicable to treat highly As(V)-contaminated wastewater. During Fe(0) surface corrosion accelerated by oxidants, a large amount of fresh and reactive iron oxides and oxyhydroxides were continuously generated, which were responsible for the rapid and efficient removal of HMs through multiple mechanisms including adsorption and co-precipitation. A steady state of Fe(0) surface activation and HM removal enabled this simply coupled system to remove HMs with high speed, efficiency and perdurability.