Concentration Of Potassium Iodide Research Articles

Photodynamic inactivation strategies for maximizing antifungal effect against Sporothrix spp. and Candida albicans in an in vitro investigation.

Sporotrichosis is a zoonotic disease caused by the dimorphic fungus Sporothrix spp., leading to skin lesions that can, in some cases, progress and result in the death of infected individuals. Candida albicans is another fungus involved in several skin, oral, and vaginal mucosal infections. Fungal diseases are concerning due to increasing incidence and the limited variety of antifungal classes available for treatment. Furthermore, antifungal medications can cause various side effects, exacerbated by their prolonged use during infection treatment. There is a need to explore alternatives to conventional drugs that are effective, fast, and safe in combating sporotrichosis. This study aimed to achieve in vitro elimination of the fungi Sporothrix brasiliensis and Sporothrix schenckii through Photodynamic Inactivation (PDI), using curcumin as a photosensitizer and in combination with antifungal agents used in the treatment of sporotrichosis. Yeasts of Candida albicans, Sporothrix brasiliensis, and Sporothrix schenckii were subjected to Photodynamic Inactivation (PDI) using light at a wavelength of 450 ± 10 nm, irradiance of 35 mW/cm2, delivering a fluence of 31.5 J/cm2, with curcumin as the photosensitizer at doses ranging from 0.75 to 150 μg/mL. After determining the Minimum Inhibitory Concentration (MIC) values of the antifungal drugs itraconazole, ketoconazole, and potassium iodide, sub-MIC doses of these antifungals were combined with sub-MIC doses of curcumin in a new PDI session. Photodynamic inactivation is a promising technique in the treatment of sporotrichosis, as well as its combination with antifungals. The combination of curcumin in concentrations ranging from 0.75 g/mL a 7.5 g/mL with sub-MIC concentrations of itraconazole, ketoconazole, and potassium iodide was able to completely inactivate the fungi C. albicans, S. brasiliensis and S. schenckii, indicating that PDI may increase the effectiveness of antifungals. However, further studies are needed to establish protocols for future clinical applications.

Process for Producing Lithium Iodide Cleanly through Electrodialysis Metathesis.

Lithium iodide is commonly used in the production of batteries and drugs. Currently, the neutralization method is the primary means of producing lithium iodide. This method involves using hydriodic acid as a raw material, adding lithium carbonate or lithium hydroxide, and obtaining lithium iodide through evaporation and concentration. However, hydriodic acid is chemically unstable. Its preparation can lead to explosive accidents and encountering high temperatures generates toxic iodine vapors. These limitations restrict its industrial production. The study evaluates the impact of membrane stack configuration, operating voltage, and initial concentrations and volume ratios of reactants on the production process. Electrodialysis metathesis, characterized by a simpler process flow, lower energy consumption, and environmental benefits, emerges as an effective technique for electrically driven membrane separation in lithium salt production and purification. Under the specific conditions of a C-C-A-C-A-C membrane stack configuration, operating voltage at 25 V, initial potassium iodide concentration at 0.4 mol/L, initial lithium sulfate concentration at 0.2 mol/L, and a 1:1 volume ratio of product liquid to raw material liquid, the method achieves a lithium iodide purity of 98.9% with a production cost of approximately 0.502 $/kg LiI.

Liquid iodine sensitization for enhanced mid-infrared detection of lead selenide films

In pursuit of addressing the inherent challenges associated with gas partial pressure control and non-uniform diffusion of solid iodine encountered in conventional sensitization methods, this study delves into the impact of liquid sensitization on the structural and electrical properties of lead selenide (PbSe) films. The sensitization process entails iodination of PbSe films within varying concentrations of potassium iodide (KI) solutions, followed by high-temperature sensitization. The phase composition, surface morphologies, carrier concentration and mobility, and detectivity of the PbSe films after sensitization were investigated systematically. Our findings illuminate the transformative potential of liquid iodine sensitization in the modification of the crystal boundary barrier within PbSe films, thereby engendering substantial enhancements in both structural and electrical attributes. Iodine assumes a pivotal role in the orchestration of this boundary barrier modulation, which, in turn, has birthed an innovative methodology for crafting high-performance PbSe photodetectors. Remarkably, when films were sensitized with a KI concentration of 0.05 M, the maximum detectivity achieved reached an impressive 2.27 × 109 Jones. This study not only deepens our understanding of the underlying mechanisms responsible for the optoelectronic response of PbSe films but also underscores the immense potential of liquid iodine sensitization as a promising way for elevating their overall performance.

KI Increases Tomato Fruit Quality and Water Deficit Tolerance by Improving Antioxidant Enzyme Activity and Amino Acid Accumulation: A Priming Effect or Relief during Stress?

A water deficit can negatively impact fruit yield and quality, affecting critical physiological processes. Strategies to mitigate water deficits are crucial to global food security. Iodine (I) may increase the efficiency of the antioxidant system of plants, but its role against water deficits is poorly understood. This study aimed to evaluate the effectiveness of I in attenuating water deficits and improving fruit quality, investigating whether metabolic responses are derived from a “priming effect” or stress relief during water deficits. Tomato plants were exposed to different concentrations of potassium iodide (KI) via a nutrient solution and subjected to a water deficit. A water deficit in tomatoes without KI reduced their yield by 98%. However, a concentration of 100 μM of KI increased the yield under a water deficit by 28%. This condition is correlated with increased antioxidant activity, photosynthetic efficiency improvement, and malondialdehyde reduction. In addition, the concentration of 100 μM of KI promoted better fruit quality through antioxidant capacity and a decline in the maturation index. Therefore, KI can be an alternative for attenuating water deficits in tomatoes, inducing positive responses during the water deficit period while at the same time improving fruit quality.

A Uniform Design Method Can Optimize the Combinatorial Parameters of Antimicrobial Photodynamic Therapy, Including the Concentrations of Methylene Blue and Potassium Iodide, Light Dose, and Methylene Blue's Incubation Time, to Improve Fungicidal Effects on Candida Species.

The optimal combinatorial parameters of antimicrobial photodynamic therapy (aPDT) mediated by methylene blue (MB) with the addition of potassium iodide (KI) against Candida species have never been defined. This study aimed to optimize the combinatorial parameters of aPDT, including the concentrations of MB (X1, 0.1-1.0 mM) and KI (X2, 100-400 mM), light dose (X3, 10-70 J/cm2), and MB's incubation time (X4, 5-35 min) for three Candida species. The best MB + KI-aPDT fungicidal effects (Y) against Candida albicans ATCC 90028 (YCa), Candida parapsilosis ATCC 22019 (YCp), and Candida glabrata ATCC 2950 (YCg) were investigated using a uniform design method. The regression models deduced using this method were YCa = 7.126 + 1.199X1X3 - 1.742X12 + 0.206X22 - 0.361X32; YCp = 10.724 - 0.867X1 - 1.497X2 + 0.560X3 + 1.298X22; and YCg = 0.892 - 0.956X1 + 2.296X3 + 1.299X42 - 3.316X3X4. The optimal combinatorial parameters inferred from the regression equations were MB 0.1 mM, KI 400 mM, a light dose of 20 J/cm2, and a 5-minute incubation time of MB for Candida albicans; MB 0.1 mM, KI 400 mM, a light dose of 70 J/cm2, and a 5-minute incubation time of MB for Candida parapsilosis; MB 0.1 mM, KI 100 mM, a light dose of 10 J/cm2, and a 35-minute incubation time of MB for Candida glabrata. The uniform design method can optimize the combinatorial parameters of aPDT mediated by MB plus KI to obtain the best aPDT fungicidal effects on Candida species, providing a new method to optimize the combinatorial parameters of aPDT for different pathogens in the future.

Soybean Plants Exposed to Low Concentrations of Potassium Iodide Have Better Tolerance to Water Deficit through the Antioxidant Enzymatic System and Photosynthesis Modulation.

Water deficit inhibits plant growth by affecting several physiological processes, which leads to the overproduction of reactive oxygen species (ROS) that may cause oxidative stress. In this regard, iodine (I) is already known to possibly enhance the antioxidant defense system of plants and promote photosynthetic improvements under adverse conditions. However, its direct effect on water deficit responses has not yet been demonstrated. To verify the efficiency of I concerning plant tolerance to water deficit, we exposed soybean plants to different concentrations of potassium iodide (KI) fed to pots with a nutrient solution and subsequently submitted them to water deficit. A decline in biomass accumulation was observed in plants under water deficit, while exposure to KI (10 and 20 μmol L-1) increased plant biomass by an average of 40%. Furthermore, exposure to KI concentrations of up to 20 μM improved gas exchange (~71%) and reduced lipid peroxidation. This is related to the higher enzymatic antioxidant activities found at 10 and 20 μM KI concentrations. However, when soybean plants were properly irrigated, KI concentrations greater than 10 μM promoted negative changes in photosynthetic efficiency, as well as in biomass accumulation and partition. In sum, exposure of soybean plants to 10 μM KI improved tolerance to water deficit, and up to this concentration, there is no evidence of phytotoxicity in plants grown under adequate irrigation.

Effects of Gamma Irradiation on Optical Properties of Poly(ethylene oxide) Thin Films Doped with Potassium Iodide

In this study, the effect of gamma irradiation on the optical properties of thin films of polymer electrolytes was investigated. The thin films were composed of poly(ethylene oxide) (PEO) doped with different concentrations of potassium iodide (KI) salt. The optical absorption spectrum of each film was measured using a UV–Vis spectrophotometer over a range of 300 to 800 nm. The PEO thin-film samples were subjected to gamma irradiation at two different doses of 100 and 200 Gy generated by a Co-60 source. It was found that the optical properties of the thin films were significantly influenced by the KI dopant concentration and gamma irradiation. Increasing both the KI concentration and the gamma irradiation dose resulted in a reduction in the energy gap and an increase in the absorption coefficient, extinction coefficient, refractive index, and dielectric constant of the PEO electrolyte. These findings have potential applications in the optimization of polymers for use in optical devices and energy storage systems.

Light-induced antifungal activity of nanoparticles with an encapsulated porphyrin photosensitizer

The strong antifungal effect of sulfonated polystyrene nanoparticles (NPs) with an encapsulated tetraphenylporphyrin (TPP) photosensitizer is reported here. TPP is activated by visible light, resulting in the generation of singlet oxygen. Its antifungal action is potentiated in the presence of potassium iodide, yielding I2/I3⁻, another antifungal species. The NPs exhibit no dark toxicity, but a broad spectrum of antifungal photodynamic effects. The efficiency of this rapid killing (on the order of minutes) depends on the concentration of TPP NPs, potassium iodide, yeast species and temperature. A strong antifungal activity of TPP NPs is demonstrated on eleven pathogenic and opportunistic pathogenic yeast species (six Candida species and other yeast species, including melanized Hortaea werneckii). The composition and architecture of yeast cell envelope structures clearly influence the efficacy of photodynamic therapy. Candida krusei is the most sensitive to photodynamic therapy. Despite expectations, melanin does not provide Hortaea cells with marked resistance compared to white yeast species. The kinetics of the interaction of NPs with yeast cells is also described. This study may inspire and promote the fabrication of a new type of antiseptic for various skin injuries in clinical medicine.

Multi-commutated flow system for inorganic selenium speciation in infusion tea samples by chemical vapor generation atomic fluorescence spectrometry

This work proposes an automated strategy for the inorganic selenium speciation in infusion tea samples, employing an MSFIA-CVG-AFS system and sodium tetrahydroborate for chemical vapor generation. The selenium total is determined after an online prereduction step of selenium (VI) to selenium (IV) in alkaline media, using a UV reactor with a 15 W Hg lamp. Selenium (IV) is quantified directly on the sample, and selenium (VI) is determined by the difference between the total selenium and selenium (IV) concentrations. The optimization of the chemical parameters: hydrochloric acid – hydrobromide acid solution concentration, potassium iodide concentration, sodium hydroxide concentration, and sodium tetrahydroborate concentration was performed using a (24−1) two-level fractional factorial design. The validation parameters were determined for total selenium and selenium (IV), and the results found were: limits of detection and quantification of 0.05 and 0.18 μg L−1, respectively; a linear range of 0.18–5.0 μg L−1, precision expressed as the relative standard deviation of 2.1% for a sample number of 10, for both analytes. The system allows the speciation analysis with an injection throughput of 15 injections per hour. This analytical method was applied for inorganic selenium speciation in nine infusions of tea samples purchased commercially in supermarkets in Palma de Mallorca City, Spain. The concentrations of selenium (IV) and total selenium varied from 0.2 to 0.6 μg L−1 and 0.4–2.0 μg L−1, respectively. The accuracy method was evaluated using spike tests, and the recoveries achieved varied from 91 to 111%.

A microfluidic paper-based analytical device for iodometric titration of ascorbic acid and dopamine

A simple, rapid, and on-site iodometric titration with minimal preparation was devised utilizing a novel combination of traditional redox titration and microfluidic paper-based analytical devices (μPADs). The star-shaped pattern titration μPADs consists of a central sample loading zone connected to ten lateral reaction/detection reservoirs. The reaction reservoirs contain various concentrations of copper (II) acetate monohydrate with well-defined concentration gradient intervals and a fixed concentration of potassium iodide. This will result in a gradient of yellow color indicating iodine liberation as titrant in lateral reservoirs. The titration is stimulated when the test solution is applied to the central sample zone. As soon as the sample solution reaches the reaction zones (30 sec. after sample introduction), a constant concentration of amylose solution is added to the detection reservoirs, which serves as an indicator. The analyte is oxidized by the liberated iodine and the excess iodine reacts with amylose indicator, characterized by the formation of dark brownish-blue color. Therefore, the concentrations of target analyte solutions can be determined just in 30 sec., totally instrument-free and directly by naked-eye without calibration. The proposed μPADs are capable of determining ascorbic acid and dopamine solutions ranging from 1.0 × 10−5 M to 1.0 × 10−2 M. The detection lower limit is 1.0 × 10−5 M which is too difficult to measure using conventional volumetric iodometric titration. The reproducibility of the proposed method is lower than ± 5 % for five replicate measurements. The feasibility of the designed μPADs was confirmed by analysis of real samples and the results are highly consonant with those obtained from standard methods.

Effect of Different Intracanal Medicaments on the Viability and Survival of Dental Pulp Stem Cells

Background: Stem cells play an important role in the success of regenerative endodontic procedures. They are affected by the presence of medicaments that are used before the induction of bleeding or the creation of a scaffold for endodontic regeneration. This study examines the effects of different intracanal medicaments on the viability and survival of dental pulp stem cells at different doses and over different exposure times. Methods: Dental pulp stem cells were cultured from healthy third molar teeth using the long-term explant culture method and characterized using flow cytometry and exposed to different concentrations of calcium hydroxide, doxycycline, potassium iodide, triamcinolone, and glutaraldehyde, each ranging from 0 (control) to 1000 µg/mL. Exposure times were 6, 24, and 48 h. Cell viability was measured using the MTT assay, and apoptosis was measured using the Annexin V-binding assay. Results: All medicaments significantly reduced cell viability at different concentrations over different exposure times. Calcium hydroxide and triamcinolone favored cell viability at higher concentrations during all exposure times compared to other medicaments. The apoptosis assay showed a significant increase in cell death on exposure to doxycycline, potassium iodide, and glutaraldehyde. Conclusion: The intracanal medicaments examined in our study affected the viability of dental pulp stem cells in a time and dose-dependent manner. They also adversely affected the survival of dental pulp stem cells. Further studies are needed to better understand the effect of prolonged exposure to medicaments according to clinical protocols and their effect on the stemness of dental pulp stem cells.

Statistically designed extractive spectrophotometric determination scheme for bismuth(III) with 2-chlorobenzaldehyde thiocarbohydrazone: Analysis of environmental and real resources

The principle of liquid-liquid extraction followed by spectrophotometric determination of bismuth(III) was elaborated. The yellow complex of bismuth(III) with 2-chlorobenzaldehyde thiocarbohydrazone in presence of potassium iodide is soluble in chloroform and was extracted from HCl-KCl buffer having pH 1.2. The concentration of 2-chlorobenzaldehyde thiocarbohydrazone and potassium iodide ensuring maximum absorbance were optimized well. The effect of foreign ions was also thoroughly elucidated. The maximum absorbance of the complex is witnessed at 420 nm having the values of molar absorptivity and Sandell's sensitivity as 1.086 × 10 4 L mol −1 cm −1 and 0.01923 µg cm −2 , respectively. The Beer's law is obeyed for bismuth(III) concentrations over the range of 4.80 to 16.0 μg mL −1 . The composition of [Bi(III)-2CBTCH-iodide] complex was found to be 1:1:1. The scheme has been applied for the determination of bismuth(III) in environmental and real resources.

Disturbance of potassium iodide solution on nonlinear chemical oscillation system of (NH4)4Ce(SO4)4-NaBrO3-malonic acid

The objective of this paper was to study the effect of potassium iodide solution on nonlinear chemical oscillation system of (NH4)4Ce(SO4)4-NaBrO3-malonic acid in the food safety detection. Taking milk powder and pure water blank samples as tested samples, click the menu to collect data. When oscillation curve went on smoothly to 8 min, potassium iodide solution of different concentration was injected, respectively, and the influence of potassium iodide solution of each concentration on intuitive information and characteristic parameters of the corresponding oscillation spectrum was investigated. The results showed that when the concentration of potassium iodide was higher than 1 × 10-3 mol/L, visual information and some characteristic parameters of nonlinear chemical oscillation spectra of milk powder and pure water blank samples were greatly disturbed, and there was a good linear relationship between oscillatory end time and the concentration of potassium iodide, and correlation coefficient was 0.9902. At the same time, this study provided a reference for the study of disturbance of other components on nonlinear chemical oscillation system in the food safety detection.

Response of intra canal medicaments on viability and survival of SHEDs.

Regenerative endodontic procedures (REP) rely on the principles of tissue engineering and take advantage of the regenerative abilities of Stem Cells derived from human exfoliated deciduous teeth (SHEDs). Since REPs advise the minimal instrumentation of root canals, they are more dependent on intracanal medicaments with antimicrobial activity to provide a sterile environment for pulpal regeneration. Hence present trial was conducted to examine the influence of different intracanal medicaments on SHEDs proliferation and survival. SHEDs were cultured by using the long-term explant culture method and characterized using flow cytometry and exposed to different concentrations of calcium hydroxide, doxycycline, potassium iodide, triamcinolone, and glutaraldehyde. SHEDs were subjected to the 3-(4,5- dimethylthiazol -2 -yl)-2,5-diphenyl-2H- tetrazolium bromide (MTT) assay, apoptosis using the Annexin V-binding assay and Alkaline Phosphatase (ALP) activity. All medicaments significantly reduced cell viability at different concentrations over different exposure times. Highest number of live cells and ALP activity was observed in SHEDs cultured in calcium hydroxide. Potassium iodide and glutaraldehyde were the significantly less likely of all the medications examined to adversely affect the viability and survival of SHEDs.

Formulation and Evaluation of Throat Paint of Erythromycin Estolate

The research work was aimed at developing and optimizing erythromycin estolate throat paint solution for improved bioavailability in the oral delivery of based throat paint is prepared by unique method. Potassium iodide, glycerol has been selected based on mouth paint, mucoadhesive strength, and the drug the medication with the goal of treating wooping cough. Erythromycin estolateis released in vitro. A 32factorial prototype was used to preparation the throat paint at concentration of potassium iodide and glycerol was used as an independent variable released in vitro and permeated by percentage.For throat paint, the percentage of mucoadhesion, product consistency,releaseof drugs in vitro, and percentage of rest from permeation were calculated. With mucoadhesive strength, percentage permeation and in-vitro drug releaseperformance, formula f9 has been optimized. Studies of FTIR and have characterised throat paint. Study of stability revealed stable formulation was found.

Comparison of the optical and electrical energy band gap of a thin layer of polyelectrolyte based on MEH-PPV and KI

A thin layer of polyelectrolyte based on Poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEH-PPV) and potassium iodide (KI) was prepared using the sol-gel method. Comprehensive studies of the optical and electrical energy gap of the produced material were carried out. Using the Thermo Scientific Evolution 220 spectrophotometer equipped with a xenon lamp in the wavelength range from 190 to 1110nm, the absorbance A was measured. The optical energy gap (Egopt) was calculated. With the change in the concentration of potassium iodide, the change in the energy band gap of polyelectrolyte thin film was registered. In this paper, the cyclic voltammetry (CV) for testing electrochemical properties was used. The location of energy levels HOMO, LUMO and the value of the energy band gap were calculated, which is very important for polymeric materials that conduct electricity and the possibility of their use in solar cells.

Studying the influence of mungbean use on the structure-forming indicators of meat-plant systems based on veal, pork, chicken meat

This paper reports a study into the use of germinated mungbean as a promising raw material influencing the structure-forming indicators of meat systems during the production of meat-vegetable sausages. The content of iodine in the germinated mungbean and its anatomical parts has been examined using solutions of potassium iodide. A change in the phytic acid content and size of phytin globoloids has been established in mungbean malt depending on germination conditions. The influence of flour from germinated mungbean on the moisture-binding, moisture-retaining, fat-retaining abilities, as well as on the pH of meat systems based on veal meat, pork, chicken has been investigated. The reported set of studies is important as the defined patterns could make it possible to devise technologies for meat-vegetable sausages, to expand the range of enriched meat products. The result of this study has established that the degree of biotransformation of iodine into beans is influenced by the protein content in the native beans. Almost 90...95 % of iodine is accumulated in the cotyledons of beans in the protein fraction, 5...10 % ‒ in sprouts and roots. The rational range of potassium iodide concentrations in the germination solution is 76.5 g per 1,000 cm3, over 48 hours. Prolonging the germination time leads to microbiological damage to the bean mass. The germination process affects the reduction of phytic acid content, which is confirmed by a decrease in the diameter of phytin globoloids. It is rational to use in meat systems based on pork meat and veal meat 10 % of the developed flour by reducing meat raw materials. With this ratio of formulation ingredients, the maximum increase in the moisture-binding, moisture-retaining, and fat-retaining capacities of these meat systems is achieved. In the meat systems based on chicken meat, it is possible to increase a replacement part of up to 15 %. The reported set of studies is useful and important because it could form the basis for devising the technologies of meat-vegetable sausages to meet the needs of different segments of consumers

Optimal concentration of potassium iodide to reduce the black staining of silver diamine fluoride

Background/purposePotassium iodide (KI) is used for reducing the degree of black staining occurred after silver diamine fluoride (SDF) application. However, the optimal KI concentration remains unknown. This study aimed to identify the optimal concentration of KI that effectively reduces black staining after SDF application. Materials and methodsTwenty-four extracted teeth with similar pattern of carious lesions were assigned into 6 groups as follows: 1) SDF only, 2) SDF+7.5%KI, 3) SDF+10%KI, 4) SDF+15%KI, 5) SDF+20%KI, and 6) SDF+saturated KI. The KI solution was applied immediately after SDF application. Tooth images were obtained for color measurement at different time points as followed; before SDF application, immediately after SDF application, immediately after KI application, 1, 3, 7 and 14 days after SDF+KI application. The photographs were analyzed for mean gray value using the ImageJ program. ResultsThe KI groups demonstrated a dose-dependent significant immediate reduction in black staining after KI application, except the saturated KI group. The teeth in the 20% KI group had the highest Δ mean gray value compared with other groups immediately after KI application, whereas a reduction in black staining in the saturated KI group appeared 1 day after KI application. The Δ mean gray value in all groups decreased over time. After 7 and 14 days, the reduction in black staining was not clearly different between KI groups. ConclusionKI application was able to reduce the degree of black staining in a dose-dependent manner, but the subsequent color change was minimal over the period of 14 days.

Effect of Selenium and Iodine on Oxidative Stress in the First Trimester Human Placenta Explants.

Imbalanced maternal micronutrient status, poor placentation, and oxidative stress are associated with greater risk of pregnancy complications, which impact mother and offspring health. As selenium, iodine, and copper are essential micronutrients with key roles in antioxidant systems, this study investigated their potential protective effects on placenta against oxidative stress. First trimester human placenta explants were treated with different concentrations of selenium (sodium selenite), iodine (potassium iodide), their combination or copper (copper (II) sulfate). The concentrations represented deficient, physiological, or super physiological levels. Oxidative stress was induced by menadione or antimycin. Placenta explants were collected, fixed, processed, and embedded for laser ablation inductively coupled plasma-mass spectrometry (LA ICP-MS) element imaging or immunohistochemical labelling. LA ICP-MS showed that placenta could uptake selenium and copper from the media. Sodium selenite and potassium iodide reduced DNA damage and apoptosis (p < 0.05). Following oxidative stress induction, a higher concentration of sodium selenite (1.6 µM) was needed to reduce DNA damage and apoptosis while both concentrations of potassium iodide (0.5 and 1 µM) were protective (p < 0.05). A high concentration of copper (40 µM) increased apoptosis and DNA damage but this effect was no longer significant after induction of oxidative stress. Micronutrients supplementation can increase their content within the placenta and an optimal maternal micronutrient level is essential for placenta health.

Highly Quantum-Yield Enhancement of InP Quantum-Dot Emitting Red-Light Via Potassium Doping for Quantum-Dot Organic-Light-Emitting-Diode Display

Quantum dots (QD) have been researched intensively among several luminescent materials because they can simply adjust wavelength, high efficiency, high stability, and high color purity properties. In particular, eco-friendly InP based core-shell QDs without environmental regulations (i.e., restriction of hazardous substances in Europe) has been a great of attention.1 However, it is difficult to synthesize InP-based core-shell QDs, which requires a high temperature, a long reaction time, and a high reactivity precursor since the InP-based core-shell QDs need a strong covalent bonds, degrading quantum yield(QY)2. For this reason, many defects in QDs are generated during a InP core growth. Among the blue(B)-, green(G)-, and red(R)-light emitting QDs, especially R-light emitting InP based core-shell QDs contain numerous crystalline defects since the core size should be increased to reduce the energy band gap. In our study, we enhanced highly QY of R-light emitting InP based core-shell QDs(R-QDs) by doping potassium ions via injecting potassium ion precursor such as potassium iodide during a InP core growth. We characterized the mechanism why potassium ion doping highly enhanced QY by observing the crystallinity of core-shell QD and electron paramagnetic resonance(EPR) analysis.In general, the R-QDs contain vacancy defect in the InP core-QDs which emit the red-light with ~625-nm in wavelength, degrading QY by lattice scattering, as shown in Fig. 1(a). These vacancy defects induced lattice-scattering and cause a decrease of QY. Here, the vacancy defects in the InP core-QDs would be passivated by doping potassium ions via using potassium iodide as a dopant, as shown in Fig. 1(b). In the InP core-QDs, the mole fraction of potassium ions to indium ions linearly increased with the potassium iodide concentration, measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), as shown in Fig. 1(c). Then, the InP core/ZnSe inter-shell/ZnSeS inter-shell/ZnS oueter-shell QDs (i.e.; InP core-shell QDs) were synthesized by using a precipitation method. The QY of the InP core-shell QDs peaked at a specific potassium iodide concentration; i.e., 91% at the potassium iodide concentration of 3%, as shown in Fig. 1(d). Otherwise, both full-width at half maximum (FWHM) and the wavelength emitting red-light gradually increased with the potassium iodide concentration.To understand the dependency of QY on the potassium iodide concentration, the crystallinity of InP core-shell QDs were investigated as a function of the potassium iodide concentration during growing the InP core-QDs, where in four different crystalline plane peaks were found; (unknown), (111), (220), and (311), as shown in Fig. 1(e). Particularly, the crystalline peak intensity of (unknown) rapidly increased with increasing QY, indicating the doping of potassium ions during growing the InP core-QDs passivated vacancy defects so that it suppressed an un-proper growth along unknown crystalline direction, as shown in Fig. 1(e). In addition, the exciton lifetime exponentially increased with QY, measured by time-resolved photoluminescence (TRPL), meaning that the passivation of vacancy defects with potassium ions enhanced the exciton lifetime of the InP core-shell QDs. It was found that there was a good correlation between QY and the crystalline peak intensity of (unknown) or the exciton lifetime, implying that the passivation of vacancy defects in the InP core-QDs by doping potassium iodide ions would enhance the QY of the InP core-shell QDs, as shown in Fig.1(f). Finally, the international commission on illumination (CIE) 1931 color spaces of a QD OLED display using R-, G-, and B-QD functional color filters, as shown in Fig.1(g), achieved 121.7% (NTSC) and 91.1% (Rec. 2020), as shown in Fig. 1(h) inset figure. Reference [1] Tamang, S.; Lincheneau, C.; Hermans, Y.; Jeong, S.; Reiss, P.; (2016). Chemistry of InP Nanocrystal Syntheses. Chem. Mater. 28, 2491−2506[2] Jang, E.; Kim, Y.; Won, Y.; Jang, H.; Choi, S.; (2020). Environmentally Friendly InP-Based Quantum Dots for Efficient Wide Color Gamut Displays. ACS Energy Lett. 5, 1316−1327 Figure 1